Search

The progression of proteinuric kidney diseases is associated with podocyte loss, but the mechanisms underlying this process remain unclear. Podocytes reenter the cell cycle to repair double-stranded DNA breaks. However, unsuccessful repair can result in podocytes crossing the [G.sub.1]/S checkpoint and undergoing abortive cytokinesis. In this study, we identified Pfn1 as indispensable in maintaining glomerular integrity--its tissue-specific loss in mouse podocytes resulted in severe proteinuria and kidney failure. Our results suggest that this phenotype is due to podocyte mitotic catastrophe (MC), characterized histologically and ultrastructurally by abundant multinucleated cells, irregular nuclei, and mitotic spindles. Podocyte cell cycle reentry was identified using FUCCI2aR mice, and we observed altered expression of cellcycle associated proteins, such as p21, p53, cyclin B1, and cyclin D1. Podocyte-specific translating ribosome affinity purification and RNA-Seq revealed the downregulation of ribosomal RNA-processing 8 (Rrp8). Overexpression of Rrp8 in Pfn1-KO podocytes partially rescued the phenotype in vitro. Clinical and ultrastructural tomographic analysis of patients with diverse proteinuric kidney diseases further validated the presence of MC podocytes and reduction in podocyte PFN1 expression within kidney tissues. These results suggest that profilinl is essential in regulating the podocyte cell cycle and its disruption leads to MC and subsequent podocyte loss., Introduction Podocytes are specialized terminally differentiated epithelial cells that line the kidney filtration barrier. Unlike typical epithelial cells that are compressed against their basement membrane, podocytes are situated on the [...]

* Context.--Pathologist interobserver discordance is significant in grading of prostate cancer, limiting reliability. Diagnostic reproducibility may be improved with digital images, but adoption faces workflow, cost, and quality challenges. A novel digital method using an alternative tissue processing approach and novel laser microscopy system potentially addresses these issues. Objective.--To evaluate the capability of this new method for primary diagnostic interpretation in clinical prostate biopsy specimens. Design.--Forty patients with a high likelihood of prostate cancer based on magnetic resonance imaging consented to investigational core biopsy. A subset of samples was used for direct comparison of physical slide preparation effects and time-tracking determination with multiphoton microscopy. Twenty samples were processed for diagnostic comparison between multilevel digital slides and subsequently produced physical slides. A reference diagnosis based on all data was established using grade groups. Level of diagnostic match and requests for immunohistochemistry were compared between physical and digital diagnoses. Immunohistochemical staining and length measurements were secondary outcomes. Results.--Interpretations based on direct multiphoton imaging yielded diagnoses that were at least as accurate as standard histology; cancer diagnosis correlation was 89% (51 of 57) by physical slides and 95% (53 of 56) by multiphoton microscopy. Grade-level concordance was 73% (44 of 60) by either method. Immunohistochemistry for routine prostate cancer-associated markers on these alternatively processed tissues was unaffected. Alternatively processed tissues resulted in longer measured core and cancer lengths, suggestive of improved orientation and visualization. Conclusions.--Findings support high potential for complete interpretation of prostate core biopsies using solely multiphoton microscopy of intact specimens, with potential diagnostic benefits as well as reduced processing time and reduced processing complexity. doi: 10.5858/arpa.2020-0037-OA, Increasing adoption of digital pathology promises marked improvements in reproducibility, efficiency, and accuracy of tissue-based diagnostics by facilitating routine remote expert consultation and enabling computerized image analysis for clinical use. [...]

BACKGROUND. The effects of the novel coronavirus disease 2019 (COVID-19) in pregnancy remain relatively unknown. We present a case of second trimester pregnancy with symptomatic COVID-19 complicated by severe preeclampsia and placental abruption. METHODS. We analyzed the placenta for the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) through molecular and immunohistochemical assays and by and electron microscopy and measured the maternal antibody response in the blood to this infection. RESULTS. SARS-CoV-2 localized predominantly to syncytiotrophoblast cells at the materno-fetal interface of the placenta. Histological examination of the placenta revealed a dense macrophage infiltrate, but no evidence for the vasculopathy typically associated with preeclampsia. CONCLUSION. This case demonstrates SARS-CoV-2 invasion of the placenta, highlighting the potential for severe morbidity among pregnant women with COVID-19. FUNDING. Beatrice Kleinberg Neuwirth Fund and Fast Grant Emergent Ventures funding from the Mercatus Center at George Mason University. The funding bodies did not have roles in the design of the study or data collection, analysis, and interpretation and played no role in writing the manuscript., Introduction Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel betacoronavirus causing the deadly pandemic of coronavirus disease 2019 (COVID-19). The risks and specific effects of SARS-CoV-2 in pregnant [...]

The [alpha]-fetoprotein (AFP) and H19 genes are transcribed at high levels in the mammalian fetal liver but are rapidly repressed postnatally. This repression in the liver is controlled, at least in part, by the Afr1 gene. Afr1 was defined >25 years ago when BALB/cJ mice were found to have 5- to 20-fold higher adult serum AFP levels compared with all other mouse strains; subsequent studies showed that this elevation was due to higher Afp expression in the liver. H19, which has become a model for genomic imprinting, was identified initially in a screen for Afr1-regulated genes. The BALB/cJ allele ([Afr1.sup.b]) is recessive to the wild-type allele ([Afr1.sup.a]), consistent with the idea that Afr1 functions as a repressor. By high-resolution mapping, we identified a gene that maps to the Afr1 interval on chromosome 15 and encodes a putative zinc fingers and homeoboxes (ZHX) protein. In BALB/cJ mice, this gene contains a murine endogenous retrovirus within its first intron and produces predominantly an aberrant transcript that no longer encodes a functional protein. Liver-specific overexpression of a Zhx2 transgene restores wild-type H19 repression on a BALB/cJ background, confirming that this gene is responsible for hereditary persistence of Afp and H19 in the livers of BALB/cJ mice. Thus we have identified a genetically defined transcription factor that is involved in developmental gene silencing in mammals. We present a model to explain the liver-specific phenotype in BALB/cJ mice, even though Afr1 is a ubiquitously expressed gene. development | genetics | positional cloning

The article reports that Intravascular large cell lymphoma (ILCL) is a rare B-cell lymphoma that is defined by the presence of large neoplastic B cells in the lumen of blood vessels.1 At least 3 variants of ILCL have been described based on case reports and a small case series: classic, cutaneous, and hemophagocytic. The classic variant presents in elderly patients as nonspecific constitutional symptoms (fever or pain, or less frequently weight loss) or as signs of multiorgan failure.

Activating mutation ofKRASplays a significant role in the pathogenesis of common human malignancies and molecular testing ofKRASmutation has emerged as an essential biomarker in the current practice of clinical oncology. The presence ofKRASmutation is generally associated with clinical aggressiveness of the cancer and reduced survival of the patient. Therapeutically,KRASmutation testing has maximum utility in stratifying metastatic colorectal carcinoma and lung cancer patients for treatment with targeted therapy. Diagnostically,KRASmutation testing is useful in the workup of pancreaticobiliary and thyroid cancers, particularly using cytological specimens. In the era of precision medicine, the role ofKRASmutation testing is poised to expand, likely in a setting of combinatorial therapeutic strategy and requiring additional mutation testing of its upstream and/or downstream effectors. [ABSTRACT FROM PUBLISHER]

Integration of mouse endogenous retroviral (MERV) elements is responsible for an estimated 10% of spontaneous mutations that have been characterized in the laboratory mouse. We recently identified a MERV integration in the first intron of the Zinc fingers and homeoboxes 2 ( Zhx2) gene in BALB/cJ mice, resulting in reduced Zhx2 expression. This integration is found in BALB/cJ but not in other BALB/c substrains, indicating that it occurred after these substrains separated in the late 1930s. We have characterized this MERV element and show here that it belongs to the ETnII-α class of elements. Our analysis reveals that the Zhx2 ETn element lacks a 69-bp sequence compared to most other ETn elements which may be due to recombination between two identical 13-bp elements. Three mature Zhx2 transcripts are found in the liver of BALB/cJ mice. The major transcript is spliced from Zhx2 exon 1 to the 5′ ETn LTR and is polyadenylated at the 3′ LTR. Of the two less abundant transcripts, one is identical to the wild-type transcript, whereas the second contains 183 bp of ETn sequence spliced between Zhx2 exons 1 and 2. We have also sequenced and analyzed products from the fas lpr ETn found in MRL/lpr mice and show that it belongs to the ETnII-β class of elements. [ABSTRACT FROM AUTHOR]

Context.--: Urinary and Male Genital Tumours is the 8th volume of the World Health Organization Classification of Tumours series, 5th edition. Released in hard copy in September 2022, it presents an update to the classification of male genital and urinary tumors in the molecular age. Building upon previous volumes in this series, significant effort has been made to harmonize terminology across organ systems for biologically similar tumors (eg, neuroendocrine tumors). Genomic terminology has been standardized and genetic syndromes covered more comprehensively. This review presents a concise summary of this volume, highlighting new entities, notable modifications relative to the 4th edition, and elements of relevance to routine clinical practice. Objective.--: To provide a comprehensive update on the World Health Organization classification of urinary and male genital tumors, highlighting updated diagnostic criteria and terminology. Data sources.--: The 4th and 5th editions of the World Health Organization Classification of Tumours: Urinary and Male Genital Tumours. Conclusions.--: The World Health Organization has made several changes in the 5th edition of the update on urinary and male genital tumors that pathologists need to be aware of for up-to-date clinical practice. [ABSTRACT FROM AUTHOR]

The progression of proteinuric kidney diseases is associated with podocyte loss, but the mechanisms underlying this process remain unclear. Podocytes reenter the cell cycle to repair double-stranded DNA breaks. However, unsuccessful repair can result in podocytes crossing the G1/S checkpoint and undergoing abortive cytokinesis. In this study, we identified Pfn1 as indispensable in maintaining glomerular integrity -- its tissue-specific loss in mouse podocytes resulted in severe proteinuria and kidney failure. Our results suggest that this phenotype is due to podocyte mitotic catastrophe (MC), characterized histologically and ultrastructurally by abundant multinucleated cells, irregular nuclei, and mitotic spindles. Podocyte cell cycle reentry was identified using FUCCI2aR mice, and we observed altered expression of cellcycle associated proteins, such as p21, p53, cyclin B1, and cyclin D1. Podocyte-specific translating ribosome affinity purification and RNA-Seq revealed the downregulation of ribosomal RNA-processing 8 (Rrp8). Overexpression of Rrp8 in Pfn1-KO podocytes partially rescued the phenotype in vitro. Clinical and ultrastructural tomographic analysis of patients with diverse proteinuric kidney diseases further validated the presence of MC podocytes and reduction in podocyte PFN1 expression within kidney tissues. These results suggest that profilin1 is essential in regulating the podocyte cell cycle and its disruption leads to MC and subsequent podocyte loss. [ABSTRACT FROM AUTHOR]

Common intronic enhancer SNPs in Shroom3 associate with CKD in GWAS, although there is paucity of detailed mechanism. Previously, we reported a role for Shroom3 in mediating crosstalk between TGFβ1- & Wnt/Ctnnb1 pathways promoting renal fibrosis (TIF). However, beneficial roles for Shroom3 in proteinuria have also been reported suggesting pleiotropic effects. Here we focused on identifying the specific profibrotic Shroom3 motif. Given known therapeutic roles for Rho-kinase inhibitors in experimental CKD, and the established interaction between Shroom3 and Rock via its ASD2 domain, we hypothesized that Shroom3-mediated ROCK activation played a crucial role in its profibrotic function in high expressors. To test this hypothesis, we developed transgenic mice and cell lines that inducibly overexpressed wild-type- (WT-Sh3) or ASD2-domain deletion- Shroom3 (ASD2Δ-Sh3). Prior scRNAseq data showed that during TIF, Shroom3 and Rock co-expression occurred in injured tubular cells and fibroblasts, highlighting cell-types where this mechanism could be involved. Using HEK293T cells, we first confirmed absent ROCK binding and inhibited TGFβ1-signaling with ASD2Δ-Sh3-overexpression vs WT-Sh3. In mIMCD cells, ASD2Δ-Sh3 overexpression, reduced Rock activation (phospho-MYPT1), pro-fibrotic and pro-inflammatory transcripts vs WT-Sh3. Fibroblast proliferation (3T3) was also reduced with ASD2Δ-Sh3. In vivo , we studied ureteric obstruction (UUO) and Aristolochic nephropathy (AAN) as TIF models. In AAN, inducible global-, or Pan-tubular specific-, WTSh3-overexpression showed increased azotemia, and TIF vs ASD2Δ-Sh3 mice. WT-Sh3 mice consistently showed significant enrichment of Rho-GTPase, TGFβ1- and Wnt/CtnnB1- signaling in kidney transcriptome, paralleling Shroom3-coexpressed genes in tubulo-interstitial transcriptomes from human CKD. In UUO, again WT-Sh3 mice recapitulated increased fibrosis vs ASD2Δ-Sh3. Importantly, ASD2Δ-Sh3 did not develop albuminuria vs WT-Sh3, while mutating a disparate Fyn-binding Shroom3 motif induced albuminuria in mice, suggesting motif-specific roles for Shroom3 in the kidney. Hence, our data show a critical role for the Rock-binding, ASD2-domain in mediating TIF in milieu of Shroom3 excess, with relevance to human CKD.