Project description:In this study we plan to compare the profiles of control sample (cultured podocytes) with the Exoc5 knock down in cutured podocytes to examine the differentially expressed genes.
Project description:The progression of proteinuric kidney disease is associated with podocyte loss but the mechanisms remain unclear. Podocytes reenter the cell cycle to repair damaged ds DNA breaks. However, unsuccessful repair results in podocytes crossing the G1/S checkpoint and undergoes abortive cytokinesis. In this study, we identified Pfn1 as a major contributor in maintaining glomerular integrity and its loss in mice results in severe proteinuria, and kidney failure due to podocyte mitotic catastrophe, characterized by abundant multinucleated cells. Reentry of podocytes were identified by using FUCCI-2aR mice, accompanying the alteration of cell-cycle associated proteins, such as P21, P53, Cyclin B, and Cyclin D. Podocyte-specific translating ribosome affinity purification (TRAP) and RNAseq revealed a reduction of Ribosomal RNA-processing protein 8 (Rrp8) and re-expression of Rrp8 partially rescued the in-vitro phenotype. Clinical analysis of patients with proteinuric kidney disease demonstrated multinucleated podocytes and reduced podocyte profilin1 in kidney tissue. These results suggest that profilin is indispensible in regulating podocyte cell cycle and its disruption contributes to podocyte loss through mitotic catastrophe.
Project description:Background. Ageing is one of the main risk factors of cardiovascular disease. Pericytes are capillary-associated mural cells involved in the maintenance and stability of the vascular network. In the heart, the consequences of ageing on cardiac pericytes are unknown. Methods. In this study, we have combined single nucleus RNA sequencing and histological analysis to determine the effects of ageing on cardiac pericytes. Furthermore, we have conducted in vivo and in vitro analysis of RGS5 loss of function and finally have perfomed pericytes-fibroblasts co-culture studies to understand the effect of RGS5 loss of function in pericytes on the neighbouring fibroblasts. Results. We showed that ageing reduces the pericyte area and coverage. Single nucleus RNA sequencing analysis further revealed that the expression of the Regulator of G protein signalling 5 (Rgs5) is reduced in old cardiac pericytes. In vivo and in vitro studies showed that the deletion of RGS5 induces morphological changes and a pro-fibrotic gene expression signature characterized by the expression of different extracellular matrix components and growth factors like TGFB2 and PDGFB in pericytes. Indeed, the culture of fibroblasts with the supernatant of RGS5 deficient pericytes induced their activation characterized by the increased expression of α smooth muscle actin in a TFGβ2 dependent mechanism. Conclusions. Our results identify RGS5 as a crucial regulator of pericyte function during cardiac ageing. The deletion of RGS5 causes cardiac dysfunction and induces myocardial fibrosis, one of the hallmarks of cardiac ageing.
Project description:Current therapies for Fabry disease are based on reversing intra-cellular accumulation of globotriaosylceramide (Gb3) by enzyme replacement (ERT) or chaperone mediated stabilization, thereby alleviating lysosome dysfunction. However, the therapeutic effect in the regression of end-organ damage (ie. kidney damage) is limited. Ultrastructural analysis of serial human kidney biopsies showed that long-term use of ERT reduced Gb3 accumulation in podocytes but did not alter podocyte injury. A novel CRISPR-/CAS9-mediated -Galactosidase knockout podocyte cell line confirmed ERT-mediated reversal of Gb3 accumulation without resolution of lysosomal dysfunction. Transcriptomic-based connectivity mapping and SILAC-based quantitative proteomics identified alpha-synuclein (SNCA) accumulation as a key event mediating podocyte injury.
Project description:Background. Ageing is one of the main risk factors of cardiovascular disease. Pericytes are capillary-associated mural cells involved in the maintenance and stability of the vascular network. In the heart, the consequences of ageing on cardiac pericytes are unknown. Methods. In this study, we have combined single nucleus RNA sequencing and histological analysis to determine the effects of ageing on cardiac pericytes. Furthermore, we have conducted in vivo and in vitro analysis of RGS5 loss of function and finally have perfomed pericytes-fibroblasts co-culture studies to understand the effect of RGS5 loss of function in pericytes on the neighbouring fibroblasts. Results. We showed that ageing reduces the pericyte area and coverage. Single nucleus RNA sequencing analysis further revealed that the expression of the Regulator of G protein signalling 5 (Rgs5) is reduced in old cardiac pericytes. In vivo and in vitro studies showed that the deletion of RGS5 induces morphological changes and a pro-fibrotic gene expression signature characterized by the expression of different extracellular matrix components and growth factors like TGFB2 and PDGFB in pericytes. Indeed, the culture of fibroblasts with the supernatant of RGS5 deficient pericytes induced their activation characterized by the increased expression of α smooth muscle actin in a TFGβ2 dependent mechanism. Conclusions. Our results identify RGS5 as a crucial regulator of pericyte function during cardiac ageing. The deletion of RGS5 causes cardiac dysfunction and induces myocardial fibrosis, one of the hallmarks of cardiac ageing.
Project description:Defects in mitochondrial oxidative phosphorylation complexes, altered bioenergetics and metabolic shift are often seen in cancers. Here we show a role for the dysfunction of electron transport chain component, cytochrome c oxidase (CcO) in cancer progression. We show that genetic silencing of the CcO complex by shRNA expression and loss of CcO activity in multiple cell types from the mouse and human sources resulted in metabolic shift to glycolysis, loss of anchorage dependent growth and acquired invasive phenotypes. Disruption of CcO complex caused loss of transmembrane potential and induction of Ca2+/Calcineurin-mediated retrograde signaling. Propagation of this signaling, includes activation of PI3-kinase, IGF1R and Akt, Ca2+ sensitive transcription factors and also, TGF1, MMP16, periostin that are involved in oncogenic progression. Whole genome expression analysis showed up regulation of genes involved in cell signaling, extracellular matrix interactions, cell morphogenesis, cell motility and migration. The transcription profiles reveal extensive similarity to retrograde signaling initiated by partial mtDNA depletion, though distinct differences are observed in signaling induced by CcO dysfunction. The possible CcO dysfunction as a biomarker for cancer progression was supported by data showing that esophageal tumors from human patients show reduced CcO subunits IVi1 and Vb in regions that were previously shown to be hypoxic core of the tumors. Our results show that mitochondrial electron transport chain defect initiates a retrograde signaling. These results suggest that a defect in CcO complex can potentially induce tumor progression. Total RNA from control and CcO IVi1 silenced cells was extract. Three independent samples were generated for control and silenced, respectively.