Post mortem core needle biopsy regarding Covid19 fatalities

Loss of Dnmt3a and Dnmt3b resulted in failure to silence developmental genes. We also found that fetal-enhancer regions methylated by Dnmt3a and Dnmt3b were enriched for kidney disease genetic risk loci. Methylation patterns of kidneys from patients with CKD showed defects similar to those in mice with Dnmt3a and Dnmt3b deletion. CONCLUSIONS Our results indicate a potential locus-specific convergence of genetic, epigenetic, and developmental elements in kidney disease development. Copyright © 2020 by the American Society of Nephrology.BACKGROUND In males with classic Fabry disease, the processes leading to the frequent outcome of ESKD are poorly understood. Defects in the gene encoding α-galactosidase A lead to accumulation of globotriaosylceramide (GL3) in various cell types. In the glomerular podocytes, accumulation of GL3 progresses with age. Of concern, podocytes are relatively resistant to enzyme replacement therapy and are poorly replicating, with little ability to compensate for cell loss. METHODS In this study of 55 males (mean age 27 years) with classic Fabry disease genotype and/or phenotype, we performed unbiased quantitative morphometric electron microscopic studies of biopsied kidney samples from patients and seven living transplant donors (to serve as controls). We extracted clinical information from medical records and clinical trial databases. RESULTS Podocyte GL3 volume fraction (proportion of podocyte cytoplasm occupied by GL3) increased with age up to about age 27, suggesting that increasing podocyte GL3 volume fraction beyond a threshold may compromise survival of these cells. GL3 accumulation was associated with podocyte injury and loss, as evidenced by increased foot process width (a generally accepted structural marker of podocyte stress and injury) and with decreased podocyte number density per glomerular volume. PCO371 Worsening podocyte structural parameters (increasing podocyte GL3 volume fraction and foot process width) was also associated with increasing urinary protein excretion-a strong prognosticator of adverse renal outcomes in Fabry disease-as well as with decreasing GFR. CONCLUSIONS Given the known association between podocyte loss and irreversible FSGS and global glomerulosclerosis, this study points to an important role for podocyte injury and loss in the progression of Fabry nephropathy and indicates a need for therapeutic intervention before critical podocyte loss occurs. Copyright © 2020 by the American Society of Nephrology.The Von Hippel-Lindau gene product is a tumor suppressor whose ubiquitin ligase function is key to oxygen-sensing in cells, whereas Tank-binding kinase (TBK1) is a kinase mostly implicated in innate immune response. The study by Hu and colleagues in this issue reveals that VHL suppresses TBK1 activity under normoxic conditions, and that loss of VHL in kidney cancer cells renders them sensitive to TBK1 inhibition, providing a new potential target for the treatment of clear cell renal cell carcinoma.See related article by Hu et al., p. 460. ©2020 American Association for Cancer Research.Although CD4+ FOXP3+ T regulatory (Treg) cells are well-known mediators of immunologic tolerance, their influences in the tumor microenviroment are incompletely understood. Writing in this issue of Cancer Discovery, Zhang and colleagues demonstrate that in pancreatic cancer, Treg cells promote the differentiation of tumor-restraining myofibroblastic cancer-associated fibroblasts, challenging the existing notion that Treg cells enable tumor progression.See related article by Zhang et al., p. 422. ©2020 American Association for Cancer Research.Aoki and colleagues have utilized single-cell RNA sequencing and imaging mass cytometry to describe the landscape of reactive, nonmalignant immune-cell populations present in classic Hodgkin lymphoma (cHL), and delineate their spatial proximity to malignant Hodgkin-Reed-Sternberg cells. From this study, they have identified a LAG3-expressing Tr1-type Treg cell population as prevalent mainly in MHC-II-negative cHL, implying a potential functional relationship underlying the differential responsiveness of MHC-II-negative versus MHC-II-positive cHLs to immunotherapy.See related article by Aoki et al., p. 406. ©2020 American Association for Cancer Research.2'5'/3'5' cyclic GMP-AMP (cGAMP) is a second messenger produced in response to cytosolic dsDNA that activates the stimulator of interferon genes (STING) pathway. We recently discovered that cGAMP is exported by cancer cells and that this extracellular signal is an immunotransmitter key to tumor detection and elimination by the innate immune system. The enhancement of extracellular cGAMP levels therefore holds great promise for managing cancer. However, there is still much more to understand about the basic biology of cGAMP before its full therapeutic potential can be realized. To answer these questions, we must be able to detect and quantitate cGAMP with an assay that is high throughput, sensitive, and precise. Existing assays fall short of these needs. Here, we describe the development of cGAMP-Luc, a coupled enzyme assay that relies on the degradation of cGAMP to AMP by ectonucleotide pyrophosphatase phosphodiesterase 1 (ENPP1) and an optimized assay for the detection of AMP by luciferase. We also developed STING-CAP, a STING-mediated method to concentrate and purify cGAMP from any type of biological sample. We conclude that cGAMP-Luc is an economical high throughput assay that matches the accuracy of and surpasses the detection limit of mass spectrometry, the current gold standard of cGAMP quantitation. We propose that cGAMP-Luc is a powerful tool that may enable discoveries that advance insights into extracellular cGAMP levels in healthy and diseased tissues, such as cancer. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.Oligomers of amyloid β42 (Aβ42) rather than fibrils, drive the pathogenesis of Alzheimer's disease (AD). In particular, toxic oligomeric species called protofibrils (PFs) have attracted significant attention. Herein, we report RNA aptamers with higher affinity toward PFs derived from a toxic Aβ42 dimer than toward fibrils produced from wild-type Aβ42 or from a toxic, conformationally constrained Aβ42 variant, E22P-Aβ42. We obtained these RNA aptamers by using the pre-incubated dimer model of E22P-Aβ42, which dimerized via a linker located at Val-40, as the target of in vitro selection. This dimer formed PFs during incubation. Several physicochemical characteristics of an identified aptamer, E22P-AbD43, suggested that preferential affinity of this aptamer toward PFs is due to its higher affinity for the toxic dimer unit (K D = 20 ± 6.0 nM) of Aβ42 than for less-toxic Aβ40 aggregates. Comparison of circular dichroism data from the full-length and random regions of E22P-AbD43 suggested that the preferential binding of E22P-AbD43 toward the dimer might be related to the formation of a G-quadruplex structure.