Search bioRxiv⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/613679

A Bigenic mouse model of FSGS reveals perturbed pathways in podocytes, mesangial cells and endothelial cells

Potter, A. S.·Drake, K.·Brunskill, E. W.·Potter, S. S.
View original source ↗Export metadata ↓

Abstract

Focal segmental glomerulosclerosis is a major cause of end stage renal disease. Many patients prove unresponsive to available therapies. An improved understanding of the molecular basis of the disease process could provide insights leading to novel therapeutic approaches. In this study we carried out an RNA-seq analysis of the altered gene expression patterns of podocytes, mesangial cells and glomerular endothelial cells of the bigenic Cd2ap+/-, Fyn-/- mutant mouse model of FSGS. In the podocytes we observed upregulation of many genes related to the Tgf{beta} family/pathway, including Gdnf, Tgf{beta}1, Tgf{beta}2, Snai2, Vegfb, Bmp4, and Tnc. The mutant podocytes also showed upregulation of Acta2, a marker of smooth muscle and associated with myofibroblasts, which are implicated in driving fibrosis. GO analysis of the podocyte upregulated genes identified elevated protein kinase activity, increased expression of growth factors, and negative regulation of cell adhesion, perhaps related to the observed podocyte loss. Both podocytes and mesangial cells showed strong upregulation of aldehyde dehydrogenase genes involved in the synthesis of retinoic acid. Similarly, the Cd2ap+/-, Fyn-/- mesangial cells, as well as podocytes in other genetic models, and the glomeruli of human FSGS patients, all show upregulation of the serine protease Prss23, with the common thread suggesting important functionality. Another gene with strong upregulation in the Cd2ap+/-, Fyn-/- mutant mesangial cells as well as multiple other mutant mouse models of FSGS was thrombospondin, which activates the secreted inactive form of Tgf{beta}. The Cd2ap+/-, Fyn-/- mutant endothelial cells showed elevated expression of genes involved in cell proliferation, angioblast migration, angiogenesis, and neovasculature, all consistent with the formation of new blood vessels in the diseased glomerulus. The resulting global definition of the perturbed molecular pathways in the three major cell types of the mutant glomerulus provide deeper understanding of the molecular pathogenic pathways.

Source connections

Explore related subjects

pathologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Potter, A. S., Drake, K., Brunskill, E. W., Potter, S. S.. 2019-04-18. A Bigenic mouse model of FSGS reveals perturbed pathways in podocytes, mesangial cells and endothelial cells. https://doi.org/10.1101/613679

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

NAE1-Dependent Protein Neddylation Preserves Endothelial Identity and Vascular Integrity

Background: Endothelial dysfunction is a central driver of cardiovascular and inflammatory diseases, yet the post-translational mechanisms that preserve endothelial homeostasis remain incompletely understood. Protein neddylation, the covalent conjugation of a ubiquitin-like modifier, regulates diverse cellular processes, yet its physiological role in the vascular endothelium remains unknown. This study investigated whether protein neddylation is required to preserve endothelial identity and vascular homeostasis. Methods: We generated tamoxifen-inducible endothelial-specific Nae1 knockout mice to inhibit neddylation and combined bulk RNA sequencing, single-cell and single-nucleus transcriptomics, quantitative proteomics, biochemical analyses, and gain- and loss-of-function approaches to define the role of endothelial neddylation in vascular homeostasis and inflammatory injury. Results: Endothelial-specific Nae1 deletion caused rapid mortality associated with vascular leakage, platelet accumulation, inflammation, and multi-organ injury. Multi-omics analyses demonstrated profound loss of endothelial identity, characterized by suppression of core endothelial programs and activation of inflammatory, procoagulant, and pyroptotic pathways. Single-cell analyses revealed progressive endothelial dysfunction culminating in depletion of the endothelial population and remodeling of the vascular niche. Mechanistically, endothelial neddylation deficiency activated gasdermin D (GSDMD)- and gasdermin E (GSDME)-dependent pyroptosis, whereas dual inhibition of GSDMD and GSDME markedly attenuated inflammatory transcriptomic remodeling, vascular injury, hepatocyte death, immune cell infiltration, and platelet accumulation. Translational analyses demonstrated reduced endothelial neddylation in experimental endotoxemia and decreased expression of neddylation pathway components in human atherosclerosis and COVID-19 datasets. Conversely, restoration of endothelial neddylation partially reversed inflammatory endothelial transcriptomic reprogramming in vivo. Conclusions: NAE1-dependent protein neddylation is an essential regulator of endothelial identity and vascular integrity. Loss of endothelial neddylation promotes gasdermin-dependent pyroptosis and thrombo-inflammatory vascular injury, whereas restoration of the neddylation pathway mitigates inflammatory endothelial dysfunction. These findings identify endothelial neddylation as a fundamental mechanism maintaining vascular homeostasis and a potential therapeutic target for cardiovascular and inflammatory diseases.

pathology↗
bioRxiv2019

Loss of MLKL Decreases Necrotic Core but Increases Macrophage Lipid Accumulation In Atherosclerosis

ObjectivesDuring the advancement of atherosclerosis, the cellularity of the plaque is governed by the influx of monocyte-derived macrophages and their turnover via apoptotic and non-apoptotic forms of cell death. Previous reports have demonstrated that programmed necrosis, or necroptosis, of macrophages within the plaque contribute to necrotic core formation. Knockdown or inhibition of the necrosome components RIPK1 and RIPK3 slow the progression of atherosclerosis, and activation of the terminal step of necroptosis, MLKL, has been demonstrated in advanced human atherosclerotic plaques. However, whether MLKL directly contributes to lesion development and necrotic core formation has not been investigated.\n\nApproaches and ResultsMLKL expression was knocked down in atherogenic Apoe- knockout mice via subcutaneous administration of antisense oligonucleotides (ASO). During advanced atherogenesis, Mlkl knockdown potently reduced cell death in the plaque, with a significant reduction in the necrotic core. However, total lesion area in the aortic sinus remained unchanged. Furthermore, treatment with the MLKL ASO unexpectedly reduced circulating cholesterol levels compared to control ASO, while staining for lipids within the plaque was significantly increased. Peritoneal macrophages transfected with the MLKL ASO showed increased lipid loading upon incubation with modified cholesterol-rich lipoproteins. In lipid-loaded macrophages, MLKL co-localized with Rab7, a marker of the late endosome.\n\nConclusionsThese studies confirm the requirement for MLKL as the executioner of necroptosis, and as such a significant contributor to the necrotic core during atherogenesis. We also identified a previously unknown role for MLKL in interacting with endosomal trafficking components to regulate lipid uptake in macrophages during atherogenesis.

pathology↗
bioRxiv2019

Desmin is a modifier of dystrophic muscle features in Mdx mice

Duchenne muscular dystrophy (DMD) is a severe neuromuscular disease, caused by dystrophin deficiency. Desmin is like dystrophin associated to costameric structures bridging sarcomeres to extracellular matrix that are involved in force transmission and skeletal muscle integrity. In the present study, we wanted to gain further insight into the roles of desmin which expression is increased in the muscle from the mouse Mdx DMD model. We show that a deletion of the desmin gene (Des) in Mdx mice (DKO, Mdx:desmin-/-) induces a marked worsening of the weakness (reduced maximal force production) as compared to Mdx mice. Fragility (higher susceptibility to contraction-induced injury) was also aggravated and fatigue resistance was reduced in DKO mice. Moreover, in contrast to Mdx mice, the DKO mice did not undergo a muscle hypertrophy because of smaller and less numerous fibers, with reduced percentage of centronucleated fibres. Interestingly, Desmin cDNA transfer with adeno-associated virus in 1-month-old DKO mice and newborn Mdx mice improved muscle weakness. Overall, desmin plays important and beneficial roles on muscle performance, fragility and remodelling in dystrophic Mdx mice.

pathology↗