
PubReading
343 episodes — Page 6 of 7
S1 Ep 86PubReading [94] - Tissue architecture in tumor initiation and progression - J. Almagro, A. Behrens
The 3D architecture of tissues bearing tumors impacts on the mechanical microenvironment of cancer, the accessibility of stromal cells, and the routes of invasion. A myriad of intrinsic and extrinsic forces exerted by the cancer cells, the host tissue, and the molecular and cellular microenvironment modulate the morphology of the tumor and its malignant potential through mechanical, biochemical, genetic, and epigenetic cues. Recent studies have investigated how tissue architecture influences cancer biology from tumor initiation and progression to distant metastatic seeding and response to therapy. With a focus on carcinoma, the most common type of cancer, this review discusses the latest discoveries on how tumor architecture is built and how tissue morphology affects the biology and progression of cancer cells.-doi:10.1016/j.trecan.2018.04.001 - 2018
S1 Ep 85PubReading [93] - Neuroprotective Actions of Dietary Choline - J. Blusztajn, B. Slack and T. Mellott
Choline is an essential nutrient for humans. It is a precursor of membrane phospholipids (e.g., phosphatidylcholine (PC)), the neurotransmitter acetylcholine, and via betaine, the methyl group donor S-adenosylmethionine. High choline intake during gestation and early postnatal development in rat and mouse models improves cognitive function in adulthood, prevents age-related memory decline, and protects the brain from the neuropathological changes associated with Alzheimer’s disease (AD), and neurological damage associated with epilepsy, fetal alcohol syndrome, and inherited conditions such as Down and Rett syndromes. These effects of choline are correlated with modifications in histone and DNA methylation in brain, and with alterations in the expression of genes that encode proteins important for learning and memory processing, suggesting a possible epigenomic mechanism of action. Dietary choline intake in the adult may also influence cognitive function via an effect on PC containing eicosapentaenoic and docosahexaenoic acids; polyunsaturated species of PC whose levels are reduced in brains from AD patients, and is associated with higher memory performance, and resistance to cognitive decline. - doi:10.3390/nu9080815 - 2017
S1 Ep 84PubReading [92] - Progress toward understanding chromosome silencing by Xist RNA - N. Brockdorff, J. Bowness, and G. Wei
The X inactive-specific transcript (Xist) gene is the master regulator of X chromosome inactivation in mammals. Xist produces a long noncoding (lnc)RNA that accumulates over the entire length of the chromosome from which it is transcribed, recruiting factors to modify under-lying chromatin and silence X-linked genes in cis. Recent years have seen significant progress in identifying important functional elements in Xist RNA, their associated RNA-binding proteins (RBPs), and the downstream pathways for chromatin modification and gene silencing. In this review, we summarize progress in understanding both how these pathways function in Xist-mediated silencing and the complex interplay between them. - doi/10.1101/gad.337196 - 2022
S1 Ep 83PubReading [91] - Circular Dichroism Spectroscopy of DNA: From Duplexes to Quadruplexes - M. Vorlickova, J. Kypr et al
Nucleic acids bear the genetic information and participate in its expression and evolution during replication, repair, recombination, transcription, and translation. These phenomena are mostly based on recognition of nucleic acids by proteins. The major factor enabling the specific recognition is structure. Circular dichroism (CD) spectroscopy is very useful to study secondary structures of nucleic acids, in general, and DNA, in particular. CD sensitively reflects isomerizations among distinct conformational states. The isomerizations may operate as molecular switches regulating various physiological or pathological processes. Here, we review CD spectra of nucleic acids, beginning with early studies on natural DNA molecules through analyses of synthetic polynucleotides to study of selected genomic fragments. - DOI: 10.1002/chir.22064 - 2012
S1 Ep 82PubReading [90] - Functional enzyme–polymer complexes - C. Waltman, M. Olvera de la Cruz
Engineered and native enzymes are poised to solve challenges in medicine, bioremediation, and biotechnology. One important goal is the possibility of upcycling polymers using enzymes. However, enzymes are often inactive in industrial, nonbiological conditions. It is particularly difficult to protect water-soluble enzymes at elevated temperatures by methods that preserve their functionality. Through atomistic and coarse-grained molecular dynamics simulations that capture protein conformational change, we show that an enzyme, PETase (polyethylene terephthalate [PET]), can be stabilized at elevated temperatures by complexation with random copolymers into nanoscale aggregates that do not precipitate into macroscopic phases. We demonstrated the efficiency of the method by simulating complexes of random copolymers and the enzyme PETase, which depolymerizes PET, a highly used polymer. These polymers are more industrially viable than peptides and can target specific domains on an enzyme. We design the mean composition of the random copolymers to control the polymer–enzyme surface contacts and the polymer conformation. When positioned on or near the active site, these polymer contacts can further stabilize the conformation of the active site at elevated temperatures. We explore the experimental implications of this active site stabilization method and show that PETase-random copolymer complexes have enhanced activity on both small molecule substrates and solid PET films. These results provide guidelines for engineering enzyme–polymer complexes with enhanced enzyme functionality in nonbiological environments. - doi.org/10.1073 - 2022
S1 Ep 81PubReading [89] - Novel Therapeutic Target(s) for Psoriatic Disease - V. Thakur and R. Mahajan
Psoriasis and psoriatic arthritis, together known as psoriatic disease, is highly prevalent chronic relapsing inflammatory disease affecting skin, joints or both and is associated with several comorbidities such as cardiovascular, metabolic, psychiatric, renal disease etc. The etiopathogenesis of psoriasis is complex and mainly driven by aberrant immune response owing to the genetic susceptibility and various environmental factors such as trauma, infections and drugs. Recent advances in understanding molecular and cellular pathways have identified tumor necrosis factor-α (TNF-α), interleukin-17 (IL-17), IL-23, IL-22 as major contributors in psoriasis pathogenesis. Advances in the knowledge of pathophysiology, the interaction of autoinflammation and clinical phenotypes have led to the development of highly effective targeted therapeutic agents which include TNF-α, IL-17, IL-23, IL-1 α/β or IL-36 inhibitors or receptor blockers, small molecule drugs like phosphodiesterase-4 inhibitors (apremilast), Janus kinase (JAK) inhibitors, retinoic acid receptor-related orphan receptor γt (RORγt) inhibitors. These novel drugs have promised the potential of improved disease control. In recent years, the transition from biologics to biosimilars especially with TNF-α inhibitors had significant impact on decreasing health care cost and increasing therapeutic options to the patients. However, selection of right treatment for an individual patient still remains challenging. Moreover, interplay between different epigenetic mechanisms such as the DNA methylation, chromatin modifications and noncoding RNA regulation has recently been started to be deciphered. Enzymes inhibitors involved in epigenetic pathways such as DNA methyltransferases and histone deacetylases demonstrated to restore normal epigenetic patterns in clinical settings and have provided the potential as novel therapeutic targets for psoriasis. In this review, we will discuss novel biologic agents and newer therapeutic approaches in treatment of psoriatic disease.
S1 Ep 80PubReading [88] - Factors influencing self-harm thoughts and behaviours over the first year of the COVID-19 pandemic in the UK: longitudinal analysis of 49 324 adults - E. Paul and D. Fancourt
There is concern that the COVID-19 pandemic and its aftermath will result in excess suicides by increasing known risk factors such as self-harm, but evidence on how pandemic-related risk factors contribute to changes in these outcomes is lacking.In total, 26.1% and 7.9% of respondents reported self-harm thoughts and behaviours respectively at least once over the study period. The number of adverse experiences was more strongly related to outcomes than the number of worries. The largest specific adversity contributing to increases in both outcomes was having experienced physical or psychological abuse. Financial worries increased the likelihood of both outcomes in most age groups, and having had COVID-19 increased the likelihood of both outcomes in young (18–29 years) and middle-aged (45–59 years) adults. - 10.1192/bjp.2021.130 - 2022
S1 Ep 79PubReading [87] - Adipocytes, Innate Immunity and Obesity: A Mini-Review - A.Blaszczak, A. Jalilvand and W. Hsueh
The role of adipose tissue (AT) inflammation in obesity and its multiple related- complications is a rapidly expanding area of scientific interest. Within the last 30 years, the role of the adipocyte as an endocrine and immunologic cell has been progressively established. Like the macrophage, the adipocyte is capable of linking the innate and adaptive immune system through the secretion of adipokines and cytokines; exosome release of lipids, hormones, and microRNAs; and contact interaction with other immune cells. Key innate immune cells in AT include adipocytes, macrophages, neutrophils, and innate lymphoid cells type 2 (ILC2s). The role of the innate immune system in promoting adipose tissue inflammation in obesity will be highlighted in this review. T cells and B cells also play important roles in contributing to AT inflammation and are discussed in this series in the chapter on adaptive immunity. - doi: 10.3389/fimmu.2021.650768 - 2021
S1 Ep 78PubReading [86] - What is the structural chemistry of the living organism at its temperature and pressure? - J. Helliwell
The three probes of the structure of matter (X-rays, neutrons and electrons) in biology have complementary properties and strengths. The balance between these three probes within their strengths and weaknesses is perceived to change, even dramatically so at times. For the study of combined states of order and disorder, NMR crystallography is also applicable. Of course, to understand biological systems the required perspectives are surely physiologically relevant temperatures and relevant chemical conditions, as well as a minimal perturbation owing to the needs of the probe itself. These remain very tough challenges because, for example, cryoEM by its very nature will never be performed at room temperature, crystallization often requires nonphysiological chemical conditions, and X-rays and electrons cause beam damage. However, integrated structural biology techniques and functional assays provide a package towards physiological relevance of any given study. Reporting of protein crystal structures, and their associated database entries, could usefully indicate how close to the biological situation they are, as discussed in detail in this feature article. - doi.org/10.1107/S2059798320000546 - 2020
S1 Ep 77PubReading [85] - Low-dose metformin targets the lysosomal AMPK pathway through PEN2 - T. Ma, S. Lin
Metformin, the most prescribed antidiabetic medicine, has shown other benefits such as anti-ageing and anticancer effects1–4. For clinical doses of metformin, AMP-activated protein kinase (AMPK) has a major role in its mechanism of action4,5; however, the direct molecular target of metformin remains unknown. Here we show that clinically relevant concentrations of metformin inhibit the lysosomal proton pump v-ATPase, which is a central node for AMPK activation following glucose starvation6. We synthesize a photoactive metformin probe and identify PEN2, a subunit of γ-secretase7, as a binding partner of metformin with a dissociation constant at micromolar levels. Metformin-bound PEN2 forms a complex with ATP6AP1, a subunit of the v-ATPase8, which leads to the inhibition of v-ATPase and the activation of AMPK without effects on cellular AMP levels. Knockout of PEN2 or re-introduction of a PEN2 mutant that does not bind ATP6AP1 blunts AMPK activation. In vivo, liver-specific knockout of Pen2 abolishes metformin-mediated reduction of hepatic fat content, whereas intestine-specific knockout of Pen2 impairs its glucose-lowering effects. Furthermore, knockdown of pen-2 in Caenorhabditis elegans abrogates metformin- induced extension of lifespan. Together, these findings reveal that metformin binds PEN2 and initiates a signalling route that intersects, through ATP6AP1, the lysosomal glucose-sensing pathway for AMPK activation. This ensures that metformin exerts its therapeutic benefits in patients without substantial adverse effects. - https://doi.org/10.1038/s41586-022-04431-8 - 2022
S1 Ep 76PubReading [84] - Neurotrauma and Repair Research: Traumatic Brain Injury (TBI) and its Treatments - H. Algattas and J. Huang
Traumatic brain injury (TBI) affects a growing portion of the population and continues to take national spotlight with advances in imaging technology and understanding of long-term effects. However, there is large variance in TBI treatment protocols due to injury variability and lack of both mechanistic understanding and strong treatment recommendations. Recent practice suggests three disparate treatment approaches, all which aim at promoting neuroprotection after TBI, show promise: immediate hypothermia, hyper- baric oxygen, and progesterone supplementation. The research is controversial at times, yet there are abundant opportunities to develop the technology behind hypothermia and hyperbaric oxygen treatments which would surely aid in aligning the current data. Additionally, while progesterone has already been packaged in nanoparticle form it may benefit from continued formulation and administration research. The treatments and the avenues for improvement are reviewed in the present paper. - 10.4137/BECB.S10968 - 2013
S1 Ep 75PubReading [83] - CAR T cells produced in vivo to treat cardiac injury - J. Rurik, J. Epstein et al.
Fibrosis affects millions of people with cardiac disease. We developed a therapeutic approach to generate transient antifibrotic chimeric antigen receptor (CAR) T cells in vivo by delivering modified messenger RNA (mRNA) in T cell–targeted lipid nanoparticles (LNPs). The efficacy of these in vivo–reprogrammed CAR T cells was evaluated by injecting CD5-targeted LNPs into a mouse model of heart failure. Efficient delivery of modified mRNA encoding the CAR to T lymphocytes was observed, which produced transient, effective CAR T cells in vivo. Antifibrotic CAR T cells exhibited trogocytosis and retained the target antigen as they accumulated in the spleen. Treatment with modified mRNA-targeted LNPs reduced fibrosis and restored cardiac function after injury. In vivo generation of CAR T cells may hold promise as a therapeutic platform to treat various diseases. - DOI: 10.1126/science.abm0594 - 2022
S1 Ep 74PubReading [82] - How to Write a Systematic Review - R. Wright, K. Spindler et al.
Evidence-based medicine (EBM) is the combination of the best available research evidence with clinical experience and patient needs. The concept of EBM as a part of clinical decision making has become increasingly popular over the last decade. In the hierarchy of studies meta-analysis and systematic reviews occupy the highest levels. A systematic review of a clinical question can be performed by following a relatively standard form. These techniques as described here can be performed without formal training. Systematic reviews conducted in this fashion can be used as a higher form of current concepts or as review articles and replace the traditional expert opinion narrative review. - DOI: 10.1097/BLO.0b013e31802c9098
S1 Ep 72PubReading [80] - Exercise plasma boosts memory and dampens brain inflammation via clusterin - Z. De Miguel, T. Wyss-Coray et al.
Physical exercise is generally beneficial to all aspects of human and animal health, slowing cognitive ageing and neurodegeneration1. The cognitive benefits of physical exercise are tied to an increased plasticity and reduced inflammation within the hippocampus2–4, yet little is known about the factors and mechanisms that mediate these effects. Here we show that ‘runner plasma’, collected from voluntarily running mice and infused into sedentary mice, reduces baseline neuroinflammatory gene expression and experimentally induced brain inflammation. Plasma proteomic analysis revealed a concerted increase in complement cascade inhibitors including clusterin (CLU). Intravenously injected CLU binds to brain endothelial cells and reduces neuroinflammatory gene expression in a mouse model of acute brain inflammation and a mouse model of Alzheimer’s disease. Patients with cognitive impairment who participated in structured exercise for 6 months had higher plasma levels of CLU. These findings demonstrate the existence of anti-inflammatory exercise factors that are transferrable, target the cerebrovasculature and benefit the brain, and are present in humans who engage in exercise. - https://doi.org/10.1038/s41586-021-04183-x - 2021
S1 Ep 73PubReading [81] - The N-terminal cysteine is a dual sensor of oxygen and oxidative stress - A. Jung Heo, Y. Tae Kwon et al.
Cellular homeostasis requires the sensing of and adaptation to intracellular oxygen (O2) and reactive oxygen species (ROS). The Arg/N-degron pathway targets proteins that bear destabilizing N-terminal residues for degradation by the proteasome or via autophagy. Under normoxic conditions, the N-terminal Cys (Nt-Cys) residues of specific substrates can be oxidized by dioxygenases such as plant cysteine oxidases and cysteamine (2-aminoethane- thiol) dioxygenases and arginylated by ATE1 R-transferases to generate Arg-CysO2(H) (R-CO2). Proteins bearing the R-CO2 N-degron are targeted via Lys48 (K48)–linked ubiquitylation by UBR1/UBR2 N-recognins for proteasomal degradation. During acute hypoxia, such proteins are partially stabilized, owing to decreased Nt-Cys oxidation. Here, we show that if hypoxia is prolonged, the Nt-Cys of regulatory proteins can be chemically oxidized by ROS to generate Arg-CysO3(H) (R-CO3), a lysosomal N-degron. The resulting R-CO3 is bound by KCMF1, a N-recognin that induces K63-linked ubiquitylation, followed by K27-linked ubiquitylation by the noncanonical N-recognin UBR4. Autophagic targeting of Cys/N-degron substrates is mediated by the autophagic N-recognin p62/SQTSM- 1/Sequestosome-1 through recognition of K27/K63-linked ubiquitin (Ub) chains. This Cys/N-degron–dependent reprogramming in the proteolytic flux is important for cellular homeostasis under both chronic hypoxia and oxidative stress. A small-compound ligand of p62 is cytoprotective under oxidative stress through its ability to accelerate proteolytic flux of K27/K63-ubiquitylated Cys/N-degron substrates. Our results suggest that the Nt-Cys of conditional Cys/ N-degron substrates acts as an acceptor of O2 to maintain both O2 and ROS homeostasis and modulates half-lives of substrates through either the proteasome or lysosome by reprogramming of their Ub codes. - https://doi.org/10.1073/pnas.2107993118 - 2021
S1 Ep 72PubReading [79] - Nanopore sequencing technology, bioinformatics and applications - Y. Wang, K. Fai Au et al.
Rapid advances in nanopore technologies for sequencing single long DNA and RNA molecules have led to substantial improvements in accuracy, read length and throughput. These breakthroughs have required extensive development of experimental and bioinformatics methods to fully exploit nanopore long reads for investigations of genomes, transcriptomes, epigenomes and epitranscriptomes. Nanopore sequencing is being applied in genome assembly, full-length transcript detection and base modification detection and in more specialized areas, such as rapid clinical diagnoses and outbreak surveillance. Many opportunities remain for improving data quality and analytical approaches through the development of new nanopores, base-calling methods and experimental protocols tailored to particular applications. - https://doi.org/10.1038/s41587-021-01108-x - 2021
S1 Ep 71PubReading [78] - Megahertz serial crystallography - Max Wiedorn et al.
The new European X-ray Free-Electron Laser is the first X-ray free-electron laser capable of delivering X-ray pulses with a megahertz inter-pulse spacing, more than four orders of magnitude higher than previously possible. However, to date, it has been unclear whether it would indeed be possible to measure high-quality diffraction data at megahertz pulse repetition rates. Here, we show that high-quality structures can indeed be obtained using currently available operating conditions at the European XFEL. We present two complete data sets, one from the well-known model system lysozyme and the other from a so far unknown complex of a β-lactamase from K. pneumoniae involved in antibiotic resistance. This result opens up megahertz serial femtosecond crystallography (SFX) as a tool for reliable structure determination, substrate screening and the efficient measurement of the evolution and dynamics of molecular structures using megahertz repetition rate pulses available at this new class of X-ray laser source. - DOI: 10.1038/s41467-018-06156-7 - 2018
S1 Ep 70PubReading [77] - Engineering transplantable jejunal mucosal grafts using patient- derived organoids from children with intestinal failure - M. Laween, V. Li et al.
Intestinal failure (IF), following extensive anatomical or functional loss of small intestine (SI), has debilitating long-term consequences on children1. The priority of patient care is to increase the length of functional intestine, particularly the jejunum, to promote nutritional independence2. Here we construct autologous jejunal mucosal grafts using pediatric patient biomaterials and show that patient-derived organoids (PDO) can be expanded efficiently in vitro. In parallel, we generate decellularized human intestinal matrix with intact nanotopography, that forms biological scaffolds. Proteomic and Raman spectroscopy analyses reveal highly analogous biochemical profiles of human SI and colon scaffolds, indicating that they can be used interchangeably as platforms for intestinal engineering. Indeed, seeding of jejunal organoids onto either type of scaffold reliably reconstructs grafts that exhibit several aspects of physiological jejunal function, and that survive to form luminal structures after transplantation into the kidney capsule or subcutaneous pockets for up to 2 weeks. Our findings provide proof-of-concept data for engineering patient-specific jejunal grafts for children with IF, ultimately aiding in the restoration of nutritional autonomy. - doi:10.1038/s41591-020-1024-z. - 2020
S1 Ep 69PubReading [76] - The Catalytic Asymmetric Intermolecular Prins Reaction - D. Díaz-Oviedo, R. Maji, and B. List
Despite their significant potential, catalytic asymmetric reactions of olefins with formaldehyde are rare and metal-free approaches have not been previously disclosed. Here we describe an enantioselective intermolecular Prins reaction of styrenes and paraformaldehyde to form 1,3-dioxanes, using confined imino-imidodiphosphate (iIDP) Brønsted acid catalysts. Isotope labeling experiments and computations suggest a concerted, highly asynchronous addition of an acid-activated formaldehyde oligomer to the olefin. The enantioenriched 1,3-dioxanes can be transformed into the corresponding optically active 1,3-diols, which are valuable synthetic building blocks. - https://doi.org/10.1021/jacs.1c10245 - 2021
S1 Ep 68PubReading [74] - Sodium/glucose cotransporter 2 (SGLT2) inhibitors improve cardiac function by reducing JunD expression in human diabetic hearts - R. Marfella, G. Paolisso et al.
Background: The pathogenesis of experimental diabetic cardiomyopathy may involve the activator protein 1 (AP-1) member, JunD. Using non-diabetic heart transplant (HTX) in recipients with diabetes, we examined the effects of the diabetic milieu (hyperglycemia and insulin resistance) on cardiac JunD expression over 12 months. Because sodium/glucose cotransporter-2 inhibitors (SGLT2i) significantly reverse high glucose-induced AP-1 binding in the proximal tubular cell, we investigated JunD expression in a subgroup of type 2 diabetic recipients receiving SGLT2i treatment.Methods: We evaluated 77 first HTX recipients (40 and 37 patients with and without diabetes, respectively). Among the recipients with diabetes, 17 (45.9%) were receiving SGLT2i treatment. HTX recipients underwent standard clinical evaluation (metabolic status, echocardiography, coronary computed tomography angiography, and endomyocardial biopsy). In the biopsy samples, we evaluated JunD, insulin receptor substrates 1 and 2 (IRS1 and IRS2), peroxisome proliferator-activated receptor-γ (PPAR-γ), and ceramide levels using real-time polymerase chain reaction and immunofluorescence. The biopsy evaluations in this study were performed at 1–4 weeks (basal), 5–12 weeks (intermediate), and up to 48 weeks (final, end of 12-month follow-up) after HTX.Results: There was a significant early and progressive increase in the cardiac expression of JunD/PPAR-γ and ceramide levels, along with a significant decrease in IRS1 and IRS2 in recipients with diabetes but not in those without diabetes. These molecular changes were blunted in patients with diabetes receiving SGLT2i treatment. Conclusion: Early pathogenesis in human diabetic cardiomyopathy is associated with JunD/PPAR-γ overexpression and lipid accumulation following HTX in recipients with diabetes. Remarkably, this phenomenon was reduced by concomitant therapy with SGLT2i, which acted directly on diabetic hearts. - doi.org/10.1016/j.metabol.2021.154936 - 2021
S1 Ep 67PubReading [73] - Electronic health records and polygenic risk scores for predicting disease risk - R. Li, J. Moore et al.
Accurate prediction of disease risk based on the genetic make-up of an individual is essential for effective prevention and personalized treatment. Nevertheless, to date, individual genetic variants from genome-wide association studies have achieved only moderate prediction of disease risk. The aggregation of genetic variants under a polygenic model shows promising improvements in prediction accuracies. Increasingly, electronic health records (EHRs) are being linked to patient genetic data in biobanks, which provides new opportunities for developing and applying polygenic risk scores in the clinic, to systematically examine and evaluate patient susceptibilities to disease. However, the heterogeneous nature of EHR data brings forth many practical challenges along every step of designing and implementing risk prediction strategies. In this Review, we present the unique considerations for using genotype and phenotype data from biobank-linked EHRs for polygenic risk prediction. - doi.org/10.1038/s41576-020-0224-1 - 2020
S1 Ep 66PubReading [72] - Delivery strategies for macromolecular drugs in cancer therapy - Q. Guo, C. Jiang et al.
With the development of biotherapy, biomacromolecular drugs have gained tremendous attention recently, especially in drug development field due to the sophisticated functions in vivo. Over the past few years, a motley variety of drug delivery strategies have been developed for bio- macromolecular drugs to overcome the difficulties in the druggability, e.g., the instability and easily restricted by physiologic barriers. The application of novel delivery systems to deliver bio- macromolecular drugs can usually prolong the half-life, increase the bioavailability, or improve patient compliance, which greatly improves the efficacy and potentiality for clinical use of biomacromolecular drugs. In this review, recent studies regarding the drug delivery strategies for macromolecular drugs in cancer therapy are summarized, mainly drawing on the development over the last five years. - doi.org/10.1016/j.apsb.2020.01.009 - 2019
S1 Ep 65PubReading [71] - Optical Microscopy and Electron Microscopy for the Morphological Evaluation of Tendons: A Mini Review - M. Xu, B. Liu et al.
The morphological characteristics of tendons have been thoroughly evaluated via microscopy. Optical microscopy and electron microscopy are the most commonly used techniques for tendon tissue observation. According to the principles of both microscopy types, preparation and evaluation methods vary. Simple optical microscopy is commonly used in the observation of cells and extracellular matrix, and many stains, including hematoxylineosin, Van Gieson, Prussian blue, Alcian blue, and toluidine blue, are used for evaluating cells, collagen fiber arrangement, and non-collagenous proteins. Histological scoring systems have been used in many studies for semi-quantification. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) are the most commonly used electron microscopy types, and special consideration is needed for the fixation and embedding protocols. Glutaraldehyde followed by osmium is most commonly used in the chemical fixation of tendon tissue, followed by epoxy resin embedment. Longitudinal sections captured in SEM images show the arrangement of collagen fibrils and the cells and lipid drops among them, while cross-sections captured in TEM images show the diameter and distribution of collagen fibrils. SEM and TEM are used together for comprehensive evaluations. This mini review is focused on the preparation methodology and related evaluation indexes for the morphological evaluation of tendons. - DOI: 10.1111/os.12637 - 2020
S1 Ep 64PubReading [70] - Flavonoids as Anticancer Agents - D. Kopustinskiene, J. Bernatoniene et al
Flavonoids are polyphenolic compounds subdivided into 6 groups: isoflavonoids, flavanones, flavanols, flavonols, flavones and anthocyanidins found in a variety of plants. Fruits, vegetables, plant-derived beverages such as green tea, wine and cocoa-based products are the main dietary sources of flavonoids. Flavonoids have been shown to possess a wide variety of anticancer effects: they modulate reactive oxygen species (ROS)-scavenging enzyme activities, participate in arresting the cell cycle, induce apoptosis, autophagy, and suppress cancer cell proliferation and invasiveness. Flavonoids have dual action regarding ROS homeostasis—they act as antioxidants under normal conditions and are potent pro-oxidants in cancer cells triggering the apoptotic pathways and downregulating pro-inflammatory signaling pathways. This article reviews the biochemical properties and bioavailability of flavonoids, their anticancer activity and its mechanisms of action. - doi:10.3390/nu12020457 - 2020
S1 Ep 63PubReading [69]- Targeting BMI-1 in B cells restores effective humoral immune responses and controls chronic viral infection - A. Di Pietro, K. Good-Jacobson et al
Ineffective antibody-mediated responses are a key characteristic of chronic viral infection. However, our understanding of the intrinsic mechanisms that drive this dysregulation are unclear. Here, we identify that targeting the epigenetic modifier BMI-1 in mice improves humoral responses to chronic lymphocytic choriomeningitis virus. BMI-1 was upregulated by germinal center B cells in chronic viral infection, correlating with changes to the accessible chromatin landscape, compared to acute infection. B cell-intrinsic deletion of Bmi1 accelerated viral clearance, reduced splenomegaly and restored splenic architecture. Deletion of Bmi1 restored c-Myc expression in B cells, concomitant with improved quality of antibody and coupled with reduced antibody-secreting cell numbers. Specifically, BMI-1-deficiency induced antibody with increased neutralizing capacity and enhanced antibody-dependent effector function. Using a small molecule inhibitor to murine BMI-1, we could deplete antibody-secreting cells and prohibit detrimental immune complex formation in vivo. This study defines BMI-1 as a crucial immune modifier that controls antibody-mediated responses in chronic infection. - doi.org/10.1038/s41590-021-01077-y - 2021
S1 Ep 62PubReading [68] - Omega-3 fatty acids attenuate dendritic cell function via NF-κB independent of PPARγ - E. Draper and H. Roche
Long-chain n-3 polyunsaturated fatty acids (n-3 PUFA) have been shown to modulate the immune response and have therapeutic effects in inflammatory disorders. PUFA are also peroxisome proliferators-activator receptor-gamma (PPARγ) ligands; a family of ligand-activated transcription factors, which when activated antagonise the pro-inflammatory capability of nuclear factor κB (NF-κB). PPARγ plays a role in dendritic cell (DC) maturation and n-3 PUFA have been shown to affect DC maturation by decreasing activation of NF-κB. While n-3 PUFA can function as PPAR ligands, it is not known whether the NF-κB-mediated immunomodulatory properties of n-3 PUFA are PPARγ-dependent. In this study we examined whether the immunomodulatory effects of n-3 PUFA on DC activation were mediated through activation of PPARγ. Treatment of murine bone marrow derived DCs with docosahexaenoic acid (DHA; 25 μM) and eicosapentaenoic acid (EPA; 25 μM) attenuated LPS-induced DC maturation. This was characterised by suppression of IL-12 production and expression of CD40, CD80, CD86 and MHC II and enhanced production of IL-10 and expression of IL-10R. This was coincident with enhanced PPARγ expression, suppressed NF-κB activity and increased the physical interaction and cellular colocalization between NF-κB with PPARγ. To understand the functional implication of the physical association of PPARγ with NF-κB, we determined whether the specific PPARγ inhibitor, GW9662 could abolish the anti-inflammatory effect of n-3 PUFA Inhibiting PPARγ did not impede the NF-κB-mediated anti-inflammatory cytokine profile induced by EPA and DHA alone. Thus n-3 PUFA activate PPARγ and interact with NF-κB in DC. However, the anti-inflammatory effects of EPA and DHA on DCs are independent of PPARγ. - 10.1016/j.jnutbio.2010.06.009 - 2011
S1 Ep 61PubReading [67] - DNA methylation in human sperm: a systematic review - F. Asenius, A. Danson and S. Marzi
BACKGROUND: Studies in non-human mammals suggest that environmental factors can influence spermatozoal DNA methylation, and some research suggests that spermatozoal DNA methylation is also implicated in conditions such as subfertility and imprinting disorders in the offspring. Together with an increased availability of cost-effective methods of interrogating DNA methylation, this premise has led to an increasing number of studies investigating the DNA methylation landscape of human spermatozoa. However, how the human spermatozoal DNA methylome is influenced by environmental factors is still unclear, as is the role of human spermatozoal DNA methylation in subfertility and in influencing offspring health.OBJECTIVE AND RATIONALE: The aim of this systematic review was to critically appraise the quality of the current body of literature on DNA methylation in human spermatozoa, summarize current knowledge and generate recommendations for future research.SEARCH METHODS: A comprehensive literature search of the PubMed, Web of Science and Cochrane Library databases was conducted using the search terms ‘semen’ OR ‘sperm’ AND ‘DNA methylation’. Publications from 1 January 2003 to 2 March 2020 that studied human sperm and were written in English were included. Studies that used sperm DNA methylation to develop methodologies or forensically identify semen were excluded, as were reviews, commentaries, meta-analyses or editorial texts. The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) criteria were used to objectively evaluate quality of evidence in each included publication.OUTCOMES: The search identified 446 records, of which 135 were included in the systematic review. These 135 studies were divided into three groups according to area of research; 56 studies investigated the influence of spermatozoal DNA methylation on male fertility and abnormal semen parameters, 20 studies investigated spermatozoal DNA methylation in pregnancy outcomes including offspring health and 59 studies assessed the influence of environmental factors on spermatozoal DNA methylation. Findings from studies that scored as ‘high’ and ‘moderate’ quality of evidence according to GRADE criteria were summarized. We found that male subfertility and abnormal semen parameters, in particular oligozoospermia, appear to be associated with abnormal spermatozoal DNA methylation of imprinted regions. However, no specific DNA methylation signature of either subfertility or abnormal semen parameters has been convincingly replicated in genome-scale, unbiased analyses. Furthermore, although findings require independent replication, current evidence suggests that the spermatozoal DNA methylome is influenced by cigarette smoking, advanced age and environmental pollutants. Importantly however, from a clinical point of view, there is no convincing evidence that changes in spermatozoal DNA methylation influence pregnancy outcomes or offspring health.WIDER IMPLICATIONS: Although it appears that the human sperm DNA methylome can be influenced by certain environmental and physiological traits, no findings have been robustly replicated between studies. We have generated a set of recommendations that would enhance the reliability and robustness of findings of future analyses of the human sperm methylome. Such studies will likely require multicentre collaborations to reach appropriate sample sizes, and should incorporate phenotype data in more complex statistical models.doi:10.1093/humupd/dmaa025 - 2020
S1 Ep 60PubReading [66] - The 2021 Nucleic Acids Research database issue and the online molecular biology database collection - D. Rigden and X. Fernandez
The 2021 Nucleic Acids Research database Issue contains 189 papers spanning a wide range of biological fields and investigation. It includes 89 papers reporting on new databases and 90 covering recent changes to resources previously published in the Issue. A further ten are updates on databases most recently published elsewhere. Seven new databases focus on COVID-19 and SARS-CoV- 2 and many others offer resources for studying the virus. Major returning nucleic acid databases include NONCODE, Rfam and RNAcentral. Protein family and domain databases include COG, Pfam, SMART and Panther. Protein structures are covered by RCSB PDB and dispersed proteins by PED and MobiDB. In metabolism and signalling, STRING, KEGG and WikiPathways are featured, along with returning KLIFS and new DKK and KinaseMD, all focused on kinases. IMG/M and IMG/VR update in the microbial and viral genome resources section, while human and model organism genomics resources include Flybase, Ensembl and UCSC Genome Browser. Cancer studies are covered by updates from canSAR and PINA, as well as newcomers CNCdatabase and Oncovar for cancer drivers. Plant comparative genomics is catered for by updates from Gramene and GreenPhylDB. The entire Database Issue is freely available online on the Nucleic Acids Research website (https://academic.oup.com/nar). The NAR online Molecular Biology Database Collection has been substantially updated, revisiting nearly 1000 entries, adding 90 new resources and eliminating 86 obsolete databases, bringing the current total to 1641 databases. It is available at https://www. oxfordjournals.org/nar/database/c/. - doi: 10.1093/nar/gkaa1216 - 2021
S1 Ep 59PubReading [65] - Cell Cycle Regulation of Stem Cells by MicroRNAs - M. Mens and M. Ghanbari
MicroRNAs (miRNAs) are a class of small non-coding RNA molecules involved in the regulation of gene expression. They are involved in the fine-tuning of fundamental biological processes such as proliferation, differentiation, survival and apoptosis in many cell types. Emerging evidence suggests that miRNAs regulate critical pathways involved in stem cell function. Several miRNAs have been suggested to target transcripts that directly or indirectly coordinate the cell cycle progression of stem cells. Moreover, previous studies have shown that altered expression levels of miRNAs can contribute to pathological conditions, such as cancer, due to the loss of cell cycle regulation. However, the precise mechanism underlying miRNA- mediated regulation of cell cycle in stem cells is still incompletely understood. In this review, we discuss current knowledge of miRNAs regulatory role in cell cycle progression of stem cells. We describe how specific miRNAs may control cell cycle associated molecules and checkpoints in embryonic, somatic and cancer stem cells. We further outline how these miRNAs could be regulated to influence cell cycle progression in stem cells as a potential clinical application. - doi.org/10.1007/s12015-018-9808-y - 2018
S1 Ep 58PubReading [64] - Lysosome-targeting chimaeras for degradation of extracellular proteins - S. Banik, C. Bertozzi et al
The majority of therapies that target individual proteins rely on specific activity- modulating interactions with the target protein—for example, enzyme inhibition or ligand blocking. However, several major classes of therapeutically relevant proteins have unknown or inaccessible activity profiles and so cannot be targeted by such strategies. Protein-degradation platforms such as proteolysis-targeting chimaeras (PROTACs)1,2 and others (for example, dTAGs3, Trim-Away4, chaperone-mediated autophagy targeting5 and SNIPERs6) have been developed for proteins that are typically difficult to target; however, these methods involve the manipulation of intracellular protein degradation machinery and are therefore fundamentally limited to proteins that contain cytosolic domains to which ligands can bind and recruit the requisite cellular components. Extracellular and membrane-associated proteins—the products of 40% of all protein-encoding genes7—are key agents in cancer, ageing-related diseases and autoimmune disorders8, and so a general strategy to selectively degrade these proteins has the potential to improve human health. Here we establish the targeted degradation of extracellular and membrane-associated proteins using conjugates that bind both a cell-surface lysosome-shuttling receptor and the extracellular domain of a target protein. These initial lysosome-targeting chimaeras, which we term LYTACs, consist of a small molecule or antibody fused to chemically synthesized glycopeptide ligands that are agonists of the cation-independent mannose-6-phosphate receptor (CI-M6PR). We use LYTACs to develop a CRISPR interference screen that reveals the biochemical pathway for CI-M6PR-mediated cargo internalization in cell lines, and uncover the exocyst complex as a previously unidentified—but essential—component of this pathway. We demonstrate the scope of this platform through the degradation of therapeutically relevant proteins, including apolipoprotein E4, epidermal growth factor receptor, CD71 and programmed death-ligand 1. Our results establish a modular strategy for directing secreted and membrane proteins for lysosomal degradation, with broad implications for biochemical research and for therapeutics. - doi.org/10.1038/s41586-020-2545-9 - 2020
S1 Ep 57PubReading [63] - Integrated analysis of multimodal single-cell data -Y. Hao, R. Satija
The simultaneous measurement of multiple modalities represents an exciting frontier for single-cell genomics and necessitates computational methods that can define cellular states based on multimodal data. Here, we introduce ‘‘weighted-nearest neighbor’’ analysis, an unsupervised framework to learn the relative utility of each data type in each cell, enabling an integrative analysis of multiple modalities. We apply our procedure to a CITE-seq dataset of 211,000 human peripheral blood mononuclear cells (PBMCs) with panels extending to 228 antibodies to construct a multimodal reference atlas of the circulating immune system. Multimodal analysis substantially improves our ability to resolve cell states, allowing us to identify and validate previously unreported lymphoid subpopulations. Moreover, we demonstrate how to leverage this reference to rapidly map new datasets and to interpret immune responses to vaccination and coronavirus disease 2019 (COVID-19). Our approach represents a broadly applicable strategy to analyze single-cell multimodal data- sets and to look beyond the transcriptome toward a unified and multimodal definition of cellular identity. - doi.org/10.1016/j.cell.2021.04.048 - 2021
S1 Ep 56PubReading [62] - Molecular Printing with DNA Nanotechnology - F. Rizzuto, T. Trinh and H. Sleiman
DNA nanotechnology has generated a wealth of structures uniquely suited for nanoscale patterning; however, scalability, affordability, and recyclability are important preconditions for the industrial production and widespread use of DNA-based materials. In this perspective, we propose that ‘‘printing’’ programmed particles from transient DNA templates provides a practical pathway toward overcoming these hurdles. Just as a printing press transfers ink to paper in a cyclical process, DNA can translocate materials from one substrate to another while preserving spatial information. DNA printing decorates a particle with arbitrarily designed patterns that break its symmetry, enabling its autonomous assembly into complex structures. Printing thus organizes anisotropic particles with high throughput: a single DNA scaffold engenders template recyclability and hybrid material scale-up. By applying DNA-based printing methods to increasingly diverse materials, we will export DNA nanotechnology to other research areas and generate multivalent, asymmetric structures for scalable, nanoscale control of structure and function. - doi.org/10.1016/j.chempr.2020.06.012 - 2020
S1 Ep 55PubReading [61] - Discovery of a novel pseudo β-hairpin structure of N-truncated amyloid-β for use as a vaccine against Alzheimer’s disease - P. Bakrania, T. Bayer et al
One of the hallmarks of Alzheimer’s disease (AD) are deposits of amyloid-beta (Aβ) protein in amyloid plaques in the brain. The Aβ peptide exists in several forms, including full-length Aβ1-42 and Aβ1-40 – and the N-truncated species, pyroglutamate Aβ3-42 and Aβ4-42, which appear to play a major role in neurodegeneration. We previously identified a murine antibody (TAP01), which binds specifically to soluble, non-plaque N-truncated Aβ species. By solving crystal structures for TAP01 family antibodies bound to pyroglutamate Aβ3-14, we identified a novel pseudo β-hairpin structure in the N-terminal region of Aβ and show that this underpins its unique binding properties. We engineered a stabilised cyclic form of Aβ1-14 (N-Truncated Amyloid Peptide AntibodieS; the ‘TAPAS’ vaccine) and showed that this adopts the same 3-dimensional conformation as the native sequence when bound to TAP01. Active immunisation of two mouse models of AD with the TAPAS vaccine led to a striking reduction in amyloid- plaque formation, a rescue of brain glucose metabolism, a stabilisation in neuron loss, and a rescue of memory deficiencies. Treating both models with the humanised version of the TAP01 antibody had similar positive effects. Here we report the discovery of a unique conformational epitope in the N-terminal region of Aβ, which offers new routes for active and passive immunisation against AD. - doi.org/10.1038/s41380-021-01385-7. -2021
S1 Ep 54PubReading [60] - DNA helicases in homologous recombination repair - D. Branzei and B. Szakal
Helicases are in the spotlight of DNA metabolism and are critical for DNA repair in all domains of life. At their biochemical core, they bind and hydrolyze ATP, converting this energy to translocate unidirectionally, with different strand polarities and substrate binding specificities, along one strand of a nucleic acid. In doing so, DNA and RNA helicases separate duplex strands or remove nucleoprotein complexes, affecting DNA repair and the architecture of replication forks. In this review, we focus on recent advances on the roles and regulations of DNA helicases in homologous recombination repair, a critical pathway for mending damaged chromosomes and for ensuring genome integrity. - doi.org/10.1016/j.gde.2021.06.009 - 2021
S1 Ep 53PubReading [59] - Complexities of Viral Mutation Rates - K. Peck & A. Lauringa
Many viruses evolve rapidly. This is due, in part, to their high mutation rates. Mutation rate estimates for over 25 viruses are currently available. Here, we review the population genetics of virus mutation rates. We specifically cover the topics of mutation rate estimation, the forces that drive the evolution of mutation rates, and how the optimal mutation rate can be context-dependent. - doi.org/10.1128/JVI .01031-17. - 2018
S1 Ep 52PubReading [58] - Engineered miniature CRISPR-Cas system for mammalian genome regulation and editing - X. Xu, L. S. Qi et al.
Compact and versatile CRISPR-Cas systems will enable genome engineering applications through high-efficiency delivery in a wide variety of contexts. Here, we create an efficient miniature Cas system (CasMINI) engineered from the type V-F Cas12f (Cas14) system by guide RNA and protein engineering, which is less than half the size of currently used CRISPR systems (Cas9 or Cas12a). We demonstrate that CasMINI can drive high levels of gene activation (up to thousands-fold increases), while the natural Cas12f system fails to function in mammalian cells. We show that the CasMINI system has comparable activities to Cas12a for gene activation, is highly specific, and allows robust base editing and gene editing. We expect that CasMINI can be broadly useful for cell engineering and gene therapy applications ex vivo and in vivo. - doi.org/10.1016/j.molcel.2021.08.008 - 2021
S1 Ep 51PubReading [57] - Obesity and hypertension - G. Seravallea and G. Grassi
Obesity and in particular the excessive visceral fat distribution is accompanied by several alterations at hormonal, inflammatory and endothelial level. These alterations induce a stimulation of several other mechanisms that contribute to the hypertensive state and on the other side to increase the cardiovascular morbidity. In these chapter we will examine the main mechanisms of obesity and obesity-related hypertension and in particular the role of sympathetic nervous system, the alterations of the renal function and at the microvascular level. We will also depict the role of insulin resistance as factor stimulating and potentiating the other mechanisms. The second part will be focalized on the major target organ damage linked with obesity and obesity-related hypertension. We will finally describe the management and treatment of obesity and the antihypertensive drug therapies more effective in hypertensive obeses. - doi.org/10.1016/j.phrs.2017.05.013 - 2017
S1 Ep 50PubReading [56] - Hypertension and cardiovascular risk: General aspects - S. E. Kjeldsen
Hypertension is the strongest or one of the strongest risk factors for almost all different cardiovascular diseases acquired during life, including coronary disease, left ventricular hypertrophy and valvular heart diseases, cardiac arrhythmias including atrial fibrillation, cerebral stroke and renal failure. The continuous relationship between blood pressure and cardiovascular and renal events makes the distinction between high normal blood pressure and hypertension based on arbitrary cut-off values for blood pressures. Overall the prevalence of hypertension in different European countries appears to be around 30–45% of the general population, with a steep increase with ageing. The prevention of cardiovascular disease and treatment recommendations should be related to quantification of total cardiovascular risk which could be estimated from several different models. However the impact of age on risk is so strong that young adults (particularly women) are unlikely to reach high-risk levels even when they have more than one major risk factor and a clear increase in relative risk. Therefore age-adjusted models, models assessing relative risks compared to others of same age and models including thorough assessments of target organ damage and ambulatory 24 h blood pressure are needed together with national models because of the large variations between countries. - doi.org/10.1016/j.phrs.2017.11.003 - 2017
S1 Ep 49PubReading [55] - Protein phase separation and determinants of in cell crystallization - C. N. Mudogo, C. Betzel
Liquid-liquid phase separation (LLPS) in cells is known as a complex physicochemical process causing the formation of membrane-less organelles (MLOs). Cells have well-defined different membrane-surrounded organelles like mitochondria, endoplasmic reticulum, lysosomes, peroxisomes, etc., however, on demand they can create MLOs as stress granules, nucleoli and P bodies to cover vital functions and regulatory activities. However, the mechanism of intracellular molecule assembly into functional compartments within a living cell remains till now not fully understood. in vitro and in vivo investigations unveiled that MLOs emerge after preceding liquid-liquid, liquid gel, liquid-semi-crystalline, or liquid-crystalline phase separations. Liquid-liquid and liquid-gel MLOs form the majority of cellular phase separation events, while the occurrence of micro-sized crystals in cells was only rarely observed, however can be considered as a result of a preceding protein phase separation event. In vivo, also known and termed as in cellulo crystals, are reported since 1853. In some cases, they have been linked to vital cellular functions, such as storage and detoxification. How- ever, the occurrence of in cellulo crystals is also associated to diseases like cataract, hemoglobin C diseases, etc. Therefore, better knowledge about the involved molecular processes will support drug discovery investigations to cure diseases related to in cellulo crystallization. We summarize physical and chemical determinants known today required for phase separation initiation and formation and in cellulo crystal growth. In recent years it has been demonstrated that LLPS plays a crucial role in cell compartmentalization and formation of MLOs. Here we discuss potential mechanisms and potential crowding agents involved in protein phase separation and in cellulo crystallization. - DOI: 10.1111/tra.12711 - 2019
S1 Ep 48PubReading [54] - The Role of Inflammation in Diabetes: Current Concepts and Future Perspectives - S. Tsalamandris, D. Tousoulis et al
Diabetes is a complex metabolic disorder affecting the glucose status of the human body. Chronic hyperglycaemia related to diabetes is associated with end organ failure. The clinical relationship between diabetes and atherosclerotic cardiovascular disease is well established. This makes therapeutic approaches that simultaneously target diabetes and atherosclerotic disease an attractive area for research. The majority of people with diabetes fall into two broad pathogenetic categories, type 1 or type 2 diabetes. The role of obesity, adipose tissue, gut microbiota and pancreatic beta cell function in diabetes are under intensive scrutiny with several clinical trials to have been completed while more are in development. The emerging role of inflammation in both type 1 and type 2 diabetes (T1D and T1D) pathophysiology and associated metabolic disorders, has generated increasing interest in targeting inflammation to improve prevention and control of the disease. After an extensive review of the possible mechanisms that drive the metabolic pattern in T1D and T2D and the inflammatory pathways that are involved, it becomes ever clearer that future research should focus on a model of combined suppression for various inflammatory response pathways. - doi.org/10.15420/ecr.2018.33.1 - 2019
S1 Ep 47PubReading [53] - Molecular targeted therapy of glioblastoma - E. Le Rhun, M. Weller et al.
Glioblastomas are intrinsic brain tumors thought to originate from neuroglial stem or progenitor cells. More than 90% of glioblastomas are isocitrate dehydrogenase (IDH)-wildtype tumors. Incidence increases with age, males are more often affected. Beyond rare instances of genetic predisposition and irradiation exposure, there are no known glioblastoma risk factors. Surgery as safely feasible followed by involved-field radiotherapy plus concomitant and maintenance temozolomide chemotherapy define the standard of care since 2005. Except for prolonged progression-free, but not overall survival afforded by the vascular endothelial growth factor antibody, bevacizumab, no pharmacological intervention has been demonstrated to alter the course of disease. Specifically, targeting cellular pathways frequently altered in glioblastoma, such as the phosphoinositide 3- kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR), the p53 and the retinoblastoma (RB) pathways, or epidermal growth factor receptor (EGFR) gene amplification or mutation, have failed to improve outcome, likely because of redundant compensatory mechanisms, insufficient target coverage related in part to the blood brain barrier, or poor tolerability and safety. Yet, uncommon glioblastoma subsets may exhibit specific vulnerabilities amenable to targeted interventions, including, but not limited to: high tumor mutational burden, BRAF mutation, neurotrophic tryrosine receptor kinase (NTRK) or fibroblast growth factor receptor (FGFR) gene fusions, and MET gene amplification or fusions. There is increasing interest in targeting not only the tumor cells, but also the microenvironment, including blood vessels, the monocyte/macrophage/microglia compartment, or T cells. Improved clinical trial designs using pharmacodynamic endpoints in enriched patient populations will be required to develop better treatments for glioblastoma. - doi.org/10.1016/j.ctrv.2019.101896 - 2019
S1 Ep 46PubReading [52] - Choosing the Method of Crystallization to Obtain Optimal Results - L. Govada and N. E. Chayen
Anyone who has ever attempted to crystallise a protein or other biological macromolecule has encountered at least one, if not all of the following scenarios: No crystals at all, tiny low quality that do not diffract at all. In this paper, we review a number of simple ways to overcome such problems, which have worked well in our hands and in other laboratories. It brings together information that has been dispersed in various publications and lectures over the years and includes further information that has not been previously published. - doi:10.3390/cryst9020106 - 2019
S1 Ep 45PubReading [51] - p53, cancer and the immune response - J. Blagih, M. D. Buck and K. H. Vousden
The importance of cancer-cell-autonomous functions of the tumour suppressor p53 (encoded by TP53) has been established in many studies, but it is now clear that the p53 status of the cancer cell also has a profound impact on the immune response. Loss or mutation of p53 in cancers can affect the recruitment and activity of myeloid and T cells, allowing immune evasion and promoting cancer progression. p53 can also function in immune cells, resulting in various outcomes that can impede or support tumour development. Understanding the role of p53 in tumour and immune cells will help in the development of therapeutic approaches that can harness the differential p53 status of cancers compared with most normal tissue. - doi:10.1242/jcs.237453 - 2020
S1 Ep 44PubReading [50] - Ki-67 gene expression - S. Uxa, K. Engeland
Ki-67 serves as a prominent cancer marker. We describe how expression of the MKI67 gene coding for Ki-67 is controlled during the cell cycle. MKI67 mRNA and Ki-67 protein are maximally expressed in G2 phase and mitosis. Expression is dependent on two CHR elements and one CDE site in the MKI67 promoter. DREAM transcriptional repressor complexes bind to both CHR sites and downregulate the expression in G0/G1 cells. Upregulation of MKI67 transcription coincides with binding of B-MYB-MuvB and FOXM1-MuvB complexes from S phase into G2/M. Importantly, binding of B-MYB to the two CHR elements correlates with loss of CHR-dependent MKI67 promoter activation in B-MYB-knockdown experiments. In knockout cell models, we find that DREAM/MuvB-dependent transcriptional control cooperates with the RB Retinoblastoma tumor suppressor. Furthermore, the p53 tumor suppressor indirectly downregulates transcription of the MKI67 gene. This repression by p53 requires p21/CDKN1A. These results are consistent with a model in which DREAM, B-MYB-MuvB, and FOXM1-MuvB together with RB cooperate in cell cycle-dependent transcription and in transcriptional repression following p53 activation. In conclusion, we present mechanisms how MKI67 gene expression followed by Ki-67 protein synthesis is controlled during the cell cycle and upon induction of DNA damage, as well as upon p53 activation. - doi.org/10.1038/s41418-021-00823-x - 2021
S1 Ep 43PubReading [49] - Rationally designed ruthenium complexes for 1- and 2-photon photodynamic therapy - J. Karges, G. Gasser et al.
The use of photodynamic therapy (PDT) against cancer has received increasing attention over recent years. However, the application of the currently approved photosensitizers (PSs) is limited by their poor aqueous solubility, aggregation, photobleaching and slow clearance from the body. To overcome these limitations, there is a need for the development of new classes of PSs with ruthenium(II) polypyridine complexes currently gaining momentum. However, these compounds generally lack significant absorption in the biological spectral window, limiting their application to treat deep-seated or large tumors. To overcome this drawback, ruthenium(II) polypyridine complexes designed in silico with (E,E′)-4,4′-bisstyryl- 2,2′-bipyridine ligands show impressive 1- and 2-Photon absorption up to a magnitude higher than the ones published so far. While nontoxic in the dark, these compounds are phototoxic in various 2D monolayer cells, 3D multicellular tumor spheroids and are able to eradicate a multiresistant tumor inside a mouse model upon clinically relevant 1-Photon and 2-Photon excitation. - doi.org/10.1038/s41467-020-16993-0 - 2020
S1 Ep 42PubReading [48] - Induction of ubiquitin C (UBC) gene transcription is mediated by HSF1: role of proteotoxic and oxidative stress - M. Bianchi, M. Magnani et al.
The polyubiquitin gene ubiquitin C (UBC) is considered a stress protective gene and is upregulated under various stressful conditions, which is probably a consequence of an increased demand for ubiquitin in order to remove toxic misfolded proteins. We previously identified heat shock elements (HSEs) within the UBC promoter, which are responsible for heat shock factor (HSF)1-driven induction of the UBC gene and are activated by proteotoxic stress. Here, we determined the molecular players driving the UBC gene transcriptional response to arsenite treatment, mainly addressing the role of the nuclear factor-erythroid 2-related factor 2 (Nrf2)-mediated antioxidant pathway. Exposure of HeLa cells to arsenite caused a time-dependent increase of UBC mRNA, while cell viability and proteasome activity were not affected. Nuclear accumulation of HSF1 and Nrf2 transcription factors were detected upon both arsenite and MG132 treatment, while HSF2 nuclear levels increased in MG132-treated cells. Notably, siRNA-mediated knockdown of Nrf2 did not reduce UBC transcription under either basal or stressful conditions, but significantly impaired the constitutive and inducible expression of well-known antioxidant response element-dependent genes. A chromatin immunoprecipitation assay consistently failed to detect Nrf2 binding to the UBC promoter sequence. By contrast, depletion of HSF1, but not HSF2, significantly compromised stress-induced UBC expression. Critically, HSF1-mediated UBC trans-activation upon arsenite exposure relies on transcription factor binding to previously mapped distal HSEs, as demonstrated to occur under proteasome inhibition. These data highlight HSF1 as the pivotal transcription factor that translates different stress signals into UBC gene transcriptional induction. - doi:10.1002/2211-5463.12484 - 2018
S2 Ep 6PubReading [47] - Renal artery aneurysms - D. M. Coleman and J. C. Stanley
Renal artery aneurysms are rare in the general population, although the true incidence and natural history remain elusive. Controversy over criteria for repair persists across decades. Indications for repair presently include aneurysm size >2 cm, female gender within childbearing age, symptoms like pain and hematuria, medically refractory hypertension including that associated with functionally important renal artery stenosis, thromboembolism, dissection, and rupture. Conventional surgical reconstruction options are variable and continue to offer technically sound and durable results. Endovascular therapies with novel devices also offer technical success with few major adverse events, and are increasingly employed as indications for intervention broaden. This review summarizes the accumulated evidence on true renal artery aneurysms with a particular focus on contemporary treatment criteria, natural history, options for repair and outcomes following such. -doi.org/10.1016/j.jvs.2015.05.034 - 2015
S1 Ep 41PubReading [46] - DNA-mediated engineering of multicomponent enzyme crystals - J. D. Brodina, C. A. Mirkin et al.
The ability to predictably control the coassembly of multiple nanoscale building blocks, especially those with disparate chemical and physical properties such as biomolecules and inorganic nanoparticles, has far-reaching implications in catalysis, sensing, and photonics, but a generalizable strategy for engineering specific contacts between these particles is an outstanding challenge. This is especially true in the case of proteins, where the types of possible interparticle interactions are numerous, diverse, and complex. Herein, we explore the concept of trading protein–protein interactions for DNA–DNA interactions to direct the assembly of two nucleic-acid–functionalized proteins with distinct surface chemstries into six unique lattices composed of catalytically active proteins, or of a combination of proteins and DNA-modified gold nanoparticles. The programmable nature of DNA–DNA interactions used in this strategy allows us to control the lattice symmetries and unit cell constants, as well as the compositions and habit, of the resulting crystals. This study provides a potentially generalizable strategy for constructing a unique class of materials that take advantage of the diverse morphologies, surface chemistries, and functionalities of proteins for assembling functional crystalline materials. - doi/10.1073/pnas.1503533112 - 2015
S1 Ep 40PubReading [45] - Built-In Active Microneedle Patch with Enhanced Autonomous Drug Delivery - M.A. Lopez-Ramirez, J. Wang et al.
The use of microneedles has facilitated the painless localized delivery of drugs across the skin. However, their efficacy has been limited by slow diffusion of molecules and often requires external triggers. Herein, an autonomous and degradable, active microneedle delivery platform is introduced, employing magnesium microparticles loaded within the microneedle patch, as the built-in engine for deeper and faster intradermal payload delivery. The magnesium particles react with the interstitial fluid, leading to an explosive-like rapid production of H2 bubbles, providing the necessary force to breach dermal barriers and enhance payload delivery. The release kinetics of active microneedles is evaluated in vitro by measuring the amount of IgG antibody (as a model drug) that passed through phantom tissue and a pigskin barrier. In vivo experiments using a B16F10 mouse melanoma model demonstrate that the active delivery of anti-CTLA-4 (a checkpoint inhibitor drug) results in greatly enhanced immune response and significantly longer survival. Moreover, spatially resolved zones of active and passive microneedles allow a combinatorial rapid burst response along with slow, sustained release, respectively. Such versatile and effective autonomous dynamic microneedle delivery technology offers considerable promise for a wide range of therapeutic applications, toward a greatly enhanced outcome, convenience, and cost. - DOI: 10.1002/adma.201905740 - 2020
S1 Ep 39PubReading [44] - I-motif DNA structures are formed in the nuclei of human cells - M. Zeraati, D. Christ et al.
Human genome function is underpinned by the primary storage of genetic information in canonical B-form DNA, with a second layer of DNA structure providing regulatory control. I-motif structures are thought to form in cytosine-rich regions of the genome and to have regulatory functions; however, in vivo evidence for the existence of such structures has so far remained elusive. Here we report the generation and characterization of an antibody fragment (iMab) that recognizes i-motif structures with high selectivity and affinity, enabling the detection of i-motifs in the nuclei of human cells. We demonstrate that the in vivo formation of such structures is cell-cycle and pH dependent. Furthermore, we provide evidence that i-motif structures are formed in regulatory regions of the human genome, including promoters and telomeric regions. Our results support the notion that i-motif structures provide key regulatory roles in the genome. - doi.org/10.1038/s41557-018-0046-3 - 2018