Podocyte Proteins Research Articles

Polycystic Ovary Syndrome Accompanied by Hyperandrogenemia or Metabolic Syndrome Triggers Glomerular Podocyte Injury.

Objective: To determine whether the urinary excretion of podocyte degradation products varies according to PCOS phenotype and metabolic syndrome (MetS). Methods: The concentrations of podocalyxin (PDX) and nephrin, chronic markers of podocyte damage, and neutrophil gelatinase-associated lipocalin (NGAL), a marker of acute glomerular damage, were analyzed in the morning urine samples of 50 PCOS patients and 50 healthy controls matched by age and BMI. Albuminuria was assessed by calculating the urine albumin-creatinine ratio (uACR). Results: The PDX, nephrin and NGAL concentrations of PCOS participants were significantly higher than those of the control group. While PDX, nephrin and NGAL levels of classic phenotypes were similar, they were higher than ovulatory and non-hyperandrogenic phenotypes. Significant increases in urinary levels of each podocyte protein were detected in PCOS patients with MetS compared to patients without MetS. A positive significant correlation between podocyte proteins and BMI, systolic blood pressure, testosterone, glucose, HOMA-IR and uACR. After adjusting for age and BMI, podocyte proteins were an independent risk factor for microalbuminuria. The incidence of microalbuminuria in PCOS increased 6-fold compared to controls. The frequency of microalbuminuria was higher in classical phenotypes than in ovulatory phenotype. The frequency of microalbuminuria in PCOS patients with MetS was 6.5 times higher than in PCOS patients without MetS. Conclusions: In PCOS accompanied by hyperandrogenemia or metabolic syndrome, leakage of acute and chronic podocyte breakdown products into the urine becomes more pronounced.

Identification of Crb2 Partner Proteins in Podocytes Using BioID

Identification of Crb2 Partner Proteins in Podocytes Using BioID

Variants Involving Podocyte and Extracellular Matrix Proteins in Alport Syndrome: A Case Series

Variants Involving Podocyte and Extracellular Matrix Proteins in Alport Syndrome: A Case Series

Fabry nephropathy. Urinary expression of podocyte proteins mRNA and microRNAs in non-albuminuric patients

Fabry nephropathy. Urinary expression of podocyte proteins mRNA and microRNAs in non-albuminuric patients

Human and Mouse Nephrin and Their Interactions With 13 Proteins: An In Silico Study.

Background Human nephrin (hNeph) (podocyte protein) has been known to be involvedin both the formation and maintenance of the slit diaphragm (SD) and also acts as a hub protein in the podocyte by modulating cell polarity, cell survival, cell adhesion, cytoskeletal organization, mechano-sensing, and SD turn-over. Methodology In the present investigation, we aimed to analyse the hNeph and mouse nephrin (mNeph) and their interactions with 13 proteins using the molecular docking method. The 13 selected human proteins which include matrix metalloproteinases (MMP 2 and 9), retinol-binding proteins (RBP 3 and 4), kallikrein 1 (KLK 1), uromodulin, insulin-like growth factor binding protein 7 (IGFBP7), cystatin C, podocin, beta arrestin 1, vang-like protein 2 (VANGL2), dynamin 1, and tensin-like C1 domain-containing phosphatase (TENC1) were studied on the docking analysis of hNeph and mNeph by using the HDOCK (protein-protein) docking method. In addition, the physicochemical (PC) properties of 15 proteins were performed using the ProtParam web server. Results In the present investigation, five chosen human proteins, namely, IGFBP7, cystatin C, podocin, VANGL2, and TENC1, have exhibited theoretical isoelectric point (PI) values greater than 7.0. The protein-protein docking analysis has shown that hKLKand hVANGL2 exhibited the maximum docking score of -206.39 kcal/mol and -329.28 (kcal/mol) with the target proteins mNeph and hNeph, respectively. Conclusions Thus, the current finding highlights the interactions of hNeph and mNeph with 13 chosen proteins, which may help in renal disease management.

Loss of Nup155 promotes high fructose-driven podocyte senescence by inhibiting INO80 mRNA nuclear export

IntroductionPodocyte senescence causes podocyte loss and glomerulopathy. Excessive fructose intake is a risk factor for podocyte injury. However, whether high fructose promotes podocyte senescence remains unknown. ObjectivesTo explore the pathological mechanism by which high fructose drives podocyte senescence and find natural compounds to alleviate podocyte senescence. MethodsPodocyte senescence was characterized with senescence-associated beta-galactosidase (SA-β-gal) staining, Western blot, real-time quantitative polymerase chain reaction (qRT-PCR), comet assay and immunofluorescence. Proteomics analysis was performed to identify differentially expressed proteins in high fructose-exposed podocytes. Podocyte nuclear pore complexes (NPCs) and foot processes were observed by transmission electron microscopy. The mRNA and protein levels of nucleoporin 155 (Nup155) and inositol requiring mutant 80 (INO80) were detected by qRT-PCR, Western blot and immunofluorescence. Virtual screening was conducted to find natural compounds that target Nup155. ResultsHigh fructose increased SA-β-gal activity, protein level of p53, p21, p16 and phosphorylated histone H2AX (γ-H2AX), as well as mRNA expression of interleukin-1β (IL-1β), IL-6 and tumor necrosis factor α (TNF-α) in rat glomeruli and podocytes. Proteomic analysis unraveled a crucial molecule Nup155, which was decreased in high fructose-induced podocyte senescence. Meanwhile, the number of podocyte NPCs was also decreased in vivo and in vitro. Consistently, high fructose suppressed nuclear export of INO80 mRNA, thereby down-regulated INO80 protein expression in podocyte senescence. Deletion of Nup155 inhibited INO80 mRNA nuclear export to induce podocyte senescence, whereas overexpression of Nup155 or INO80 alleviated high fructose-induced podocyte senescence. Ferulic acid was found to up-regulate Nup155 by both direct binding to stabilize Nup155 protein and enhancing its transcription, to promote INO80 mRNA nuclear export in the mitigation of high fructose-caused podocyte senescence. ConclusionHigh fructose induces podocyte senescence by decreasing Nup155 to inhibit INO80 mRNA nuclear export. Ferulic acid targeting Nup155 may be a potential strategy to prevent high fructose-induced podocyte senescence.

Xuebijing injection and its bioactive components alleviate nephrotic syndrome by inhibiting podocyte inflammatory injury

Xuebijing injection (XBJ) is widely used to treat nephrotic syndrome (NS) in clinic, but its bioactive components and therapeutic mechanism are still unclear. In this study, the bioactive components of XBJ were determined by ultra-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF/MS). The therapeutic effect of XBJ on NS was evaluated in BALB/c mice induced by adriamycin (ADR, 10 mg/kg) via a single tail vein. The protective effect of XBJ and its bioactive components on podocytes was demonstrated using mouse podocytes (MPC-5) induced by lipopolysaccharide (LPS, 4 μg/mL). The results show that 33 components of XBJ were identified. Furthermore, 12 bioactive components were detected in blood, including protocatechuic acid, salvianolic acid C, benzoyloxypaeoniflorin, danshensu, salvianolic acid A, salvianolic acid B, catechin, caffeic acid, galloylpaeoniflorin, oxypaeoniflorin, hydroxysafflor yellow A, rosmarinic acid. The relative content (%) of the bioactive components were 59.32, 16.01, 9.97, 9.73, 8.72, 8.31, 7.92, 6.54, 1.54, 1.30, 0.68 and 0.59 in this order. After XBJ treatment, the renal function, hyperlipidemia and renal pathological damage were improved in NS model mice. Moreover, the levels of nephrin and desmin which are functional proteins in podocytes were reversed, and the levels of pro-inflammatory factors were reduced by XBJ. Interestingly, protocatechuic acid and salvianolic acid C also showed good protective effects on podocyte function and reduced the level of inflammation in LPS-induced MPC-5. The study is the first time to elucidate the bioactive components of XBJ and its potential therapeutic mechanism for treating NS by protecting podocyte function.

Role of the Ste20-like kinase SLK in podocyte adhesion.

SLK controls the cytoskeleton, cell adhesion, and migration. Podocyte-specific deletion of SLK in mice leads to podocyte injury as mice age and exacerbates injury in experimental focal segment glomerulosclerosis (FSGS; adriamycin nephrosis). We hypothesized that adhesion proteins may be substrates of SLK. In adriamycin nephrosis, podocyte ultrastructural injury was exaggerated by SLK deletion. Analysis of a protein kinase phosphorylation site dataset showed that podocyte adhesion proteins-paxillin, vinculin, and talin-1 may be potential SLK substrates. In cultured podocytes, deletion of SLK increased adhesion to collagen. Analysis of paxillin, vinculin, and talin-1 showed that SLK deletion reduced focal adhesion complexes (FACs) containing these proteins mainly in adriamycin-induced injury; there was no change in FAC turnover (focal adhesion kinase Y397 phosphorylation). In podocytes, paxillin S250 showed basal phosphorylation that was slightly enhanced by SLK; however, SLK did not phosphorylate talin-1. In adriamycin nephrosis, SLK deletion did not alter glomerular expression/localization of talin-1 and vinculin, but increased focal adhesion kinase phosphorylation modestly. Therefore, SLK decreases podocyte adhesion, but FAC proteins in podocytes are not major substrates of SLK in health and disease.

The clinical significance of the determination of urinary biomarkers of podocytic damage and fibroangiogenesis in patients with diabetes mellitus

Chronic kidney disease (CKD) in patients with diabetes mellitus (DM) remains a global medical and social problem of the 21st century and the leading cause of end-stage renal disease (ESRD). Kidney damage in diabetes is multifactorial, and diagnosis is often delayed, since structural changes in the glomeruli of the kidneys are detected before the appearance of significant albuminuria (AU) and a decrease in glomerular filtration rate. In this regard, the search for new, early informative biomarkers for the diagnosis of CKD in patients with DM is extremely relevant.Target: To establish the significance of biomarkers of podocyte dysfunction and fibro and angiogenesis excreted in the urine for early diagnosis and assessment of the risk of progression of kidney damage in patients with DM. Materials and Methods: in 74 patients with type 1 and type 2 diabetes (30 and 44, respectively), podocyte proteins and markers of fibro and angiogenesis were determined in the urine by enzyme immunoassay.Results: in patients with diabetes, compared to healthy people, there is increased urinary excretion of podocyte damage markers - nephrin, podocin, and fibroaniogenesis markers – type IV collagen, TGFβ-1, VEGF. Concentrations of nephrin in urine >7.18 ng/U/Cr urine and collagen >12.88 ng/U/Cr urine reliably indicate kidney damage. In patients with diabetes in the absence of traditional signs of CKD, diagnostically significant concentrations of nephrin were detected in 22% of cases, and collagen in 16.6%.Conclusion: determination of nephrin and/or type IV collagen in urine can be used both for early diagnosis and for monitoring kidney damage in diabetes.

Containing anti-PLA2R IgG antibody induces podocyte injury in idiopathic membranous nephropathy

Background Idiopathic membranous nephropathy is widely recognized as an autoimmune kidney disease that is accompanied by the discovery of several autoantibodies, and the antibody subclass in the circulation of patients with iMN is mainly IgG. However, the direct pathogenic effect of the containing anti-PLA2R IgG antibody on podocytes is not clear. Method A protein G affinity chromatography column was used to purify serum IgG antibodies. Containing anti-PLA2R IgG antibodies from iMN patients and IgG from healthy controls were also obtained. Based on the established in vitro podocyte culture system, purified IgG antibodies from the two groups were used to stimulate podocytes, and the expression of essential podocyte proteins (podocin), the levels of inflammatory cytokines in the cell supernatant, cytoskeletal disorders, and podocyte apoptosis were analyzed. Results Compared with that in the normal IgG group, the expression of podocin and podocin mRNA was reduced (p = 0.016 and p = 0.005, respectively), the fluorescence intensity of podocin on the surface of podocytes was reduced, the cytoskeleton of podocytes was disordered and reorganized, and the ratio of podocyte apoptosis was increased in the iMN group (p = 0.008). Conclusion The containing anti-PLA2R IgG antibody might have a direct damaging effect on podocytes in idiopathic membranous nephropathy.

Podocyte injury at young age causes premature senescence and worsens glomerular aging.

As life expectancy continues to rise, age-related diseases are becoming more prevalent. For example, proteinuric glomerular diseases typified by podocyte injury have worse outcomes in the elderly compared with young patients. However, the reasons are not well understood. We hypothesized that injury to nonaged podocytes induces senescence, which in turn augments their aging processes. In primary cultured human podocytes, injury induced by a cytopathic antipodocyte antibody, adriamycin, or puromycin aminonucleoside increased the senescence-related genes CDKN2A (p16INK4a/p14ARF), CDKN2D (p19INK4d), and CDKN1A (p21). Podocyte injury in human kidney organoids was accompanied by increased expression of CDKN2A, CDKN2D, and CDKN1A. In young mice, experimental focal segmental glomerulosclerosis (FSGS) induced by adriamycin and antipodocyte antibody increased the glomerular expression of p16, p21, and senescence-associated β-galactosidase (SA-β-gal). To assess the long-term effects of early podocyte injury-induced senescence, we temporally followed young mice with experimental FSGS through adulthood (12 m of age) and middle age (18 m of age). p16 and Sudan black staining were higher at middle age in mice with earlier FSGS compared with age-matched mice that did not get FSGS when young. This was accompanied by lower podocyte density, reduced canonical podocyte protein expression, and increased glomerular scarring. These results are consistent with injury-induced senescence in young podocytes, leading to increased senescence of podocytes by middle age accompanied by lower podocyte lifespan and health span.NEW & NOTEWORTHY Glomerular function is decreased by aging. However, little is known about the molecular mechanisms involved in age-related glomerular changes and which factors could contribute to a worse glomerular aging process. Here, we reported that podocyte injury in young mice and culture podocytes induced senescence, a marker of aging, and accelerates glomerular aging when compared with healthy aging mice.

Elevated Levels of Urinary Podocyte-Derived Microparticles in Nephrotic Syndrome

BACKGROUND: Nephrotic syndrome (NS) is the most common glomerular disease in childhood. The proposed hypothesis for the pathogenesis of this disease has changed over time, from immune dysregulation theory and systemic circulating factors theory, to the growing recognition of podocytopathies’ role. The existance of podocytopathies is usually examined by using podocyte-derived microparticles (MPs), such as nephrin, podocin, and podocalyxin (PCX). Therefore in this study, the difference between nephrin, podocin, and PCX expressions in NS children and healthy children was investigated.METHODS: An observational cross-sectional study was conducted, involving 33 children with NS and 22 age-matched healthy children as controls. Urine samples were collected from each subject in the early morning, before being processed and incubated with antibodies to detect nephrin, podocin, and PCX. The processed samples were then analyzed with flow cytometer methods.RESULTS: NS subjects had significantly higher expression of all three urinary podocyte-derived MPs compared to the control subjetcs. Nephrin, podocin, and PCX showed good discrimination in NS subjects with the area under curve (AUC) of 0.895, 0.849, and 0.728, respectively.CONCLUSION: This study revealed the differential expression of podocyte proteins in NS subjects compared to healthy controls. This supports the role of podocytopathies in the pathogenesis of NS. Therefore, nephrin, podocin, and PCX might have potentials to be future non-invasive diagnostic tools in glomerular disease.KEYWORDS: nephrin, nephrotic syndrome, podocalyxin, podocin, podocyte, urinary microparticle

CTRP4 attenuates apoptosis and epithelial-mesenchymal transition markers in podocytes through an AMPK/autophagy-dependent pathway

Hyperglycemia, characterized by high blood glucose levels resulting from pancreatic beta cell dysfunction or impaired insulin signaling, is a contributing factor in the development of diabetic nephropathy. This study aimed to investigate the effects of C1q/TNF-related protein 4 (CTRP4), known for its anti-obesity and anti-inflammatory properties in various disease models, on podocyte apoptosis and endoplasmic reticulum (ER) stress in the presence of elevated glucose levels. The expression levels of various proteins in podocytes and adipocytes were evaluated by Western blotting. Autophagosomes in podocytes were stained by MDC. Chromatin condensation in podocytes was examined by Hoechst staining. The research revealed increased expression of CTRP4 in 3T3-L1 adipocytes and CIHP-1 podocytes exposed to high glucose (HG) conditions. Treatment with CTRP4 effectively mitigated HG-induced apoptosis and ER stress and normalized epithelial-to-mesenchymal transition (EMT) markers in CIHP-1 cells. Furthermore, elevated levels of AMPK phosphorylation and autophagy were observed in CIHP-1 cells treated with CTRP4. Silencing of AMPK or the use of 3-methyl adenine (3 MA) reduced the impacts of CTRP4 on apoptosis, EMT markers and ER stress in CIHP-1 cells. In conclusion, these findings suggest that CTRP4 alleviates ER stress in podocytes under hyperglycemic conditions, leading to the suppression of apoptosis and the restoration of EMT through AMPK/autophagy-mediated signaling. These insights provide valuable information for the development of therapeutic strategies for diabetic nephropathy.

Abstract P3164: Podocalyxin, A Renal Podocyte Specific Protein Expression In Urine Exosome Acts As A Marker For Podocyte Injury During Sars-cov-2 Infection

COVID-19 attributed to SARS-CoV2 infection has been associated with cardiovascular disease and diabetes. COVID-19 has been associated with endothelial cell dysfunction (ECD), which is manifested by entities such as microvascular thrombosis. ECD is quite common in type 2 diabetes mellitus (T2DM) where the renal podocyte dysfunction is often an early manifestation of microvascular complication. We explored whether presence of hyperglycemia predisposes to increased SARS-CoV2 infection and whether SARS-CoV2 infection puts an individual at a higher risk of developing cardio-metabolic complications such as kidney disease (DKD), with podocyte damage. We evaluated albuminuria and podocyte protein in urine derived exosomes in urine exosomes from SARS-CoV2 patients at 10 days, 6 months and 12 months post SARS-CoV2 infection. Methods: Blood and Urine samples from SARS-CoV2 patients post-acute phase of infection were procured. Peripheral blood mononuclear cells (PBMNCs) and urine exosomes were isolated and podocyte protein marker Podocalyxin (PODXL) was identified by western blot analysis. Results: Podocyte specific proteins were examined in urine exosomal fraction such as Podocalyxin and Nephrin (normalized to CD9 exosomal protein band intensities) levels increased significantly compared to urine samples from type-2 diabetes subjects with documented evidence of nephropathy. Podocalyxin levels were significantly high at 12month time point (p=0.001; n=9) and Nephrin levels were noted to be high at 10week (p=0.01; n=8), 6months (p=0.04; n=14 ) and 12Months (p=0.001; n=6) time points. Podocalyxin and Nephrin obtained from urine exosome samples collected from non diabetic subjects who never had COVID-19, showed little or barely detectable corresponding western blot bands. Interestingly, there was no significant differences noted on urine albumin: creatinine (UAR) ratios between the two groups, indicating that urine exosomal protein estimation may be an ideal biomarker to monitor podocyte damage in early phases of CKD. Conclusion: A persistent high levels of podocyte specific proteins was noted in urinary exosomes even at 12 months post acute Covid which may be secondary to long-standing podocyte inflammation leading to long term renal damage.

Proteomics of Plasma and Plasma-Treated Podocytes: Application to Focal and Segmental Glomerulosclerosis.

Focal and segmental glomerulosclerosis (FSGS) is a severe form of idiopathic nephrotic syndrome (INS), a glomerulopathy of presumably immune origin that is attributed to extrarenal pathogenic circulating factors. The recurrence of FSGS (rFSGS) after transplant occurs in 30% to 50% of cases. The direct analysis of patient plasma proteome has scarcely been addressed to date, mainly due to the methodological difficulties associated with plasma complexity and dynamic range. In this study, first, we compared different methods of plasma preparation, second, we compared the plasma proteomes of rFSGS and controls using two preparation methods, and third, we analyzed the early proximal signaling events in podocytes subjected to patient plasma, through a combination of phosphoproteomics and lipid-raft proteomics (raftomics). By combining immunodepletion and high pH fractionation, we performed a differential proteomic analysis of soluble plasma proteins and of extracellular vesicles (EV) obtained from healthy controls, non-INS patient controls, and rFSGS patients (n = 4). In both the soluble- and the EV-protein sets from the rFSGS patients, we found a statistically significant increase in a cluster of proteins involved in neutrophil degranulation. A group of lipid-binding proteins, generally associated with lipoproteins, was found to be decreased in the soluble set from the rFSGS patients. In addition, three amino acid transporters involved in mTORC1 activation were found to be significantly increased in the EV from the rFSGS. Next, we incubated human podocytes for 30 min with 10% plasma from both groups of patients. The phosphoproteomics and raftomics of the podocytes revealed profound differences in the proteins involved in the mTOR pathway, in autophagy, and in cytoskeleton organization. We analyzed the correlation between the abundance of plasma and plasma-regulated podocyte proteins. The observed changes highlight some of the mechanisms involved in FSGS recurrence and could be used as specific early markers of circulating-factor activity in podocytes.

The protective role of peroxisome proliferator-activated receptor gamma in lipotoxic podocytes

Podocytes are specialized epithelial cells that maintain the glomerular filtration barrier. These cells are susceptible to lipotoxicity in the obese state and irreversibly lost during kidney disease leading to proteinuria and renal injury. PPARγ is a nuclear receptor whose activation can be renoprotective. This study examined the role of PPARγ in the lipotoxic podocyte using a PPARγ knockout (PPARγKO) cell line and since the activation of PPARγ by Thiazolidinediones (TZD) is limited by their side effects, it explored other alternative therapies to prevent podocyte lipotoxic damage.Wild-type and PPARγKO podocytes were exposed to the fatty acid palmitic acid (PA) and treated with the TZD (Pioglitazone) and/or the Retinoid X receptor (RXR) agonist Bexarotene (BX).It revealed that podocyte PPARγ is essential for podocyte function. PPARγ deletion reduced key podocyte proteins including podocin and nephrin while increasing basal levels of oxidative and ER stress causing apoptosis and cell death. A combination therapy of low-dose TZD and BX activated both the PPARγ and RXR receptors reducing PA-induced podocyte damage. This study confirms the crucial role of PPARγ in podocyte biology and that their activation in combination therapy of TZD and BX may be beneficial in the treatment of obesity-related kidney disease.

Evaluation of the immune checkpoint factors in idiopathic membranous nephropathy

Idiopathic membranous nephropathy (IMN), a single-organ autoimmune disease, is recognized by autoantibodies to podocyte proteins and identified as the most frequent cause of nephrotic syndrome in adults. T cells are important contributors in autoimmunity since they promote B–cell development, antibody production, direct inflammation, and organ tissue cytotoxicity. This study investigated the inhibitory immune checkpoint (ICP) receptors expressed on T lymphocytes and other immune cells. Thus, PBMCs from IMN patients were obtained before treatment, and the levels of ICPs such as programmed cell death protein 1 (PD-1), cytotoxic T-lymphocyte-associated protein 4 (CTLA4), lymphocyte activation gene-3 (LAG-3), and T cell immunoglobulin-3 (TIM-3) were examined at both gene and protein expression using real time PCR and Western blot tests respectively. The results illustrated that gene expression levels of ICPs reduced significantly in comparison to the control which were verified by related fold changes of protein expression sequentially. Our study revealed that CTLA-4, PD-1, TIM-3, and LAG-3 expression is impaired in IMN patients before treatment which could be a potential target for therapy.

Moshen granule ameliorates membranous nephropathy by blocking intrarenal renin-angiotensin system signalling via the Wnt1/β-catenin pathway

BackgroundMembranous nephropathy (MN) is one of the cardinal causes of nephrotic syndrome in adults, but an adequate treatment regimen is lacking. PurposeWe assessed the effect of Moshen granule (MSG) on patients with MN and cationic bovine serum albumin (CBSA)-induced rats. We further identified the bioactive components of MSG and revealed the underlying molecular mechanism of its renoprotective effects. MethodsWe determined the effect of MSG on patients with MN and CBSA-induced rats and its components on podocyte injury in zymosan-activated serum (ZAS)-elicited podocytes and revealed their regulatory mechanism on the Wnt/β-catenin/renin-angiotensin system (RAS) signalling axis. ResultsMSG treatment improved renal function and reduced proteinuria in MN patients and significantly reduced proteinuria and preserved the protein expression of podocin, nephrin, podocalyxin and synaptopodin in CBSA-induced MN rats. Mechanistically, MSG treatment significantly inhibited the protein expression of angiotensinogen, angiotensin converting enzyme and angiotensin II type 1 receptor, which was accompanied by inhibition of the protein expression of Wnt1 and β-catenin and its downstream gene products, including Snail1, Twist, matrix metalloproteinase-7, plasminogen activator inhibitor-1 and fibroblast-specific protein 1, in CBSA-induced MN rats. We further identified 81 compounds, including astragaloside IV (AGS), calycosin, barleriside A and geniposidic acid, that preserve the podocyte-specific protein expression in ZAS-induced podocytes. Among these four compounds, AGS exhibited the strongest inhibitory effects on podocyte protein expression. AGS treatment significantly inhibited the protein expression of RAS components and Wnt1 and β-catenin and its downstream gene products in ZAS-induced podocytes. In contrast, the inhibitory effect of AGS on podocyte-specific proteins, β-catenin downstream gene products and RAS components was partially abolished in ZAS-induced podocytes treated with ICG-001 and β-catenin siRNA. ConclusionThis study first demonstrates that AGS mitigates podocyte injury by inhibiting the activation of RAS signalling via the Wnt1/β-catenin pathway by both pharmacological and genetic methods. Therefore, AGS might be considered a new β-catenin inhibitor that inhibits the Wnt1/β-catenin pathway to retard MN in patients.

Identification of ARMH4 and WIPF3 as human podocyte proteins with potential roles in immunomodulation and cytoskeletal dynamics.

The podocyte is a specialized cell type critically involved in maintaining the selective filtration barrier of the kidney. Podocytes are primary or secondary targets for a multitude of kidney diseases. Despite intense investigation, the transcriptome and proteome of human podocytes remain incompletely characterized. Here, we analyzed publicly available RNA-Seq data from human kidneys (n = 85) to computationally identify potential novel podocyte markers. For confirmation, we used an online histology resource followed by in-house staining of human kidneys and biochemical fractionation of glomeruli. Initial characterization of the novel podocyte transcripts was performed using viral overexpression and mRNA silencing. Several previously unrecognized gene products were identified that correlated to established podocyte markers on the RNA level and that were histologically localized to podocytes. ARMH4 (a.k.a. UT2 or C14orf37) and WIPF3 (a.k.a CR16) were among the hits. We show that these transcripts increase in response to overexpression of the podocyte transcription factor LMX1B. Overexpression of ARMH4 from low endogenous levels in primary kidney epithelial cells reduced the release of the inflammatory mediators IL-1B and IL-8 (CXCL8). The opposite effect was seen in mature human podocytes when ARMH4 was silenced. Overexpression of WIPF3 stabilized N-WASP, known to be required for maintenance of podocyte foot processes, and increased cell motility as shown using a scratch assay. Moreover, data from normal and diseased human kidneys showed that ARMH4 was downregulated in glomerular pathologies, while WIPF3 remained constantly expressed. ARMH4 and WIPF3 are new potential markers of human podocytes, where they may modulate inflammatory insults by controlling cytokine release and contribute to cytoskeletal dynamics, respectively.

Urinary nephrin linked nephropathy in type-2 diabetes mellitus.

Diabetic nephropathy is a one of the risk factor for end stage renal disease in patients with type 2 diabetes mellitus. Urinary micr oalbumin currently marker using for diagnosis of nephropathy in type 2 diabetes mellitus due to its larger variability and less specificity. Urinary nephrin is podocyte protein can be act as a early predictable and prognostic marker than micro albumin for nephropathy in type 2 diabetes mellitus. This case-control prospective observational study included 60 type 2 diabetes mellitus and 30 controls after applying criteria. Basic biochemical, clinical and experimental data were measured and recorded. There was a significantly elevated level of urinary nephrin in type 2 diabetes mellitus patients when compared to controls. The urinary nephrin significantly elevated in normo albuminuria group only when compared to urinary ACR and it is positive association with kidney damage. This study concluded significantly elevated levels of urinary nephrin might be used for early diagnosis and prognostic marker for nephropathy in type 2 diabetes mellitus.