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Matrix Biology : Journal of the... Jun 2024Heparan sulfate (HS) is an important component of the kidney anionic filtration barrier, the glomerular basement membrane (GBM). HS chains attached to proteoglycan...
Heparan sulfate (HS) is an important component of the kidney anionic filtration barrier, the glomerular basement membrane (GBM). HS chains attached to proteoglycan protein cores are modified by sulfotransferases in a highly ordered series of biosynthetic steps resulting in immense structural diversity due to negatively charged sulfate modifications. 3-O-sulfation is the least abundant modification generated by a family of seven isoforms but creates the most highly sulfated HS domains. We analyzed the kidney phenotypes in the Hs3st3a1, Hs3st3b1 and Hs3st6 -knockout (KO) mice, the isoforms enriched in kidney podocytes. Individual KO mice show no overt kidney phenotype, although Hs3st3b1 kidneys were smaller than wildtype (WT). Furthermore, Hs3st3a1; Hs3st3b1 double knockout (DKO) kidneys were smaller but also had a reduction in glomerular size relative to wildtype (WT). Mass spectrometry analysis of kidney HS showed reduced 3-O-sulfation in Hs3st3a1 and Hs3st3b1, but not in Hs3st6 kidneys. Glomerular HS showed reduced HS staining and reduced ligand-and-carbohydrate engagement (LACE) assay, a tool that detects changes in binding of growth factor receptor-ligand complexes to HS. Interestingly, DKO mice have increased levels of blood urea nitrogen, although no differences were detected in urinary levels of albumin, creatinine and nephrin. Finally, transmission electron microscopy showed irregular and thickened GBM and podocyte foot process effacement in the DKO compared to WT. Together, our data suggest that loss of 3-O-HS domains disrupts the kidney glomerular architecture without affecting the glomerular filtration barrier and overall kidney function.
PubMed: 38944161
DOI: 10.1016/j.matbio.2024.06.006 -
International Immunopharmacology Jun 2024T cell infiltration and differentiation play a central part in the development of lupus nephritis (LN). Our prior research has indicated that protein, the primary active...
BACKGROUND
T cell infiltration and differentiation play a central part in the development of lupus nephritis (LN). Our prior research has indicated that protein, the primary active component of cordyceps (WCP), a traditional Chinese medicine, possesses properties that can enhance renal fibrosis and provide kidney protection. Nonetheless, the connection between WCP and T cell infiltration and differentiation in LN remains poorly understood.
OBJECTIVE
The objective of this research was to assess the immunomodulatory impacts of WCP in LN mice and elucidate the underlying mechanism through in vivo and in vitro investigations.
METHODS
To investigate the impact and mechanism of WCP in MRL/lpr lupus-prone mice, WCP (1.5 g/kg/d), Bailing capsules (BC, 0.75 g/kg/d), and saline in equivalent quantities were administered to the mice over a period of 8 weeks. The therapeutic effects, T cell infiltration and differentiation of WCP on MRL/lpr mice were verified through ELISA, Hematoxylin-eosin (H&E), Periodic Acid Schiff (PAS) staining, immunofluorescence, Luminex analysis and flow cytometry. The mechanism by which WCP alleviates LN was investigated using tissues of mice, T cells and Mouse Podocyte Clone-5 (MPC-5) cells by transcriptomics, Western blot (WB), and Real-time quantitative polymerase chain reaction (RT-qPCR).
RESULTS
We found that WCP improved LN in MRL/lpr mice by reducing urinary protein, creatinine, and serum auto antibodies, increasing complement 3 (C3) level, improving renal immunopathology and downregulating serum cytokines, including IFN-γ, IL-12, and RANTES. Notably, the infiltration of CD4 and CD8 T cells in the kidney was reduced by WCP. Similarly, the cell transwell co-culturation study showed that the WCP treated MPC-5 cells were weaker in inducing T cell migration. Consistent with this finding, our observations revealed that WCP could inhibit T cell-related chemokine expression in kidney and MPC-5 cells, as well as reduce the levels of TLR4, MYD88, phosphorylated-p38, phosphorylated-ERK, and phosphorylated-JNK. On the other hand, WCP was found to greatly inhibit the Th1 cells differentiation in vivo and in vitro. Cytokine-receptor induced Th1 cell differentiation pathway and PI3K-AKT pathway were the most enriched pathways based on differentially expressed genes (DEGs) enrichment analysis among different cell groups. Results from RT-qPCR and WB showed that WCP notably reduced the levels of IL-12, p-STAT4, IFN-γ, p-STAT1, p-PI3K, and p-AKT in T cells.
CONCLUSION
WCP demonstrated positive immunomodulatory effects on LN disease, by decreasing the T cells infiltration through TLR4/MYD88/MAPK signaling pathway and inhibiting Th1 cells differentiation via IL-12-STAT4 and IFN-γ-STAT1 pathways, in addition to the PI3K-AKT pathway.
PubMed: 38943968
DOI: 10.1016/j.intimp.2024.112566 -
Cytokine Jun 2024This study was designed to evaluate serum LC3-II, BCL-2, IL-1β, TGF-β1, and podocin levels in. type 2 diabetes (T2DM) patients with renal dysfunction.
UNLABELLED
This study was designed to evaluate serum LC3-II, BCL-2, IL-1β, TGF-β1, and podocin levels in. type 2 diabetes (T2DM) patients with renal dysfunction.
MATERIALS
176 Turkish subjects were enrolled, of whom 26 were healthy, and 150 had T2DM.
PATIENTS
were classified according to albumin urea ratio: 88 patients had macroalbuminuria, 20. patients had microalbuminuria, and 42 had normoalbuminuria. T2DM patients were also. classified into three groups according to proteinuria and eGFR stages.
RESULTS
Increased serum LC3-II levels in patients with T2DM with increased urinary albumin. extraction and impaired renal functions. There was a strong relationship between serum. LC3-II levels and serum BCL-2, IL-1β, TGF-β1, and Podocin levels. The efficiency of LC3- II as a diagnostic biomarker in the differential diagnosis of DM patients with. macroproteinuria from DM patients with normoproteinuria was 75.4%.
CONCLUSIONS
It was thought that increased serum LC3-II levels in T2DM patients with impaired renal. functions may cause renal podocyte damage. In these patients, serum LC3-II levels can be. evaluated as a new biomarker to follow the development of renal damage.
PubMed: 38943738
DOI: 10.1016/j.cyto.2024.156683 -
Biochemical Pharmacology Jun 2024Bitter taste receptors (TAS2Rs) Tas2r108 gene possesses a high abundance in mouse kidney; however, the biological functions of Tas2r108 encoded receptor TAS2Rs member 4...
Bitter taste receptors (TAS2Rs) Tas2r108 gene possesses a high abundance in mouse kidney; however, the biological functions of Tas2r108 encoded receptor TAS2Rs member 4 (TAS2R4) are still unknown. In the present study, we found that mouse TAS2R4 (mTAS2R4) signaling was inactivated in chronic high glucose-stimulated mouse podocyte cell line MPC, evidenced by the decreased protein expressions of mTAS2R4 and phospholipase C β2 (PLCβ2), a key downstream molecule of mTAS2R4 signaling. Nonetheless, agonism of mTAS2R4 by quinine recovered mTAS2R4 and PLCβ2 levels, and increased podocyte cell viability as well as protein expressions of ZO-1 and nephrin, biomarkers of podocyte slit diaphragm, in high glucose-cultured MPC cells. However, blockage of mTAS2R4 signaling with mTAS2R4 blockers γ-aminobutyric acid and abscisic acid, a Gβγ inhibitor Gallein, or a PLCβ2 inhibitor U73122 all abolished the effects of quinine on NLRP3 inflammasome and p-NF-κB p65 as well as the functional podocyte proteins in MPC cells in a high glucose condition. Furthermore, knockdown of mTAS2R4 with lentivirus-carrying Tas2r108 shRNA also ablated the effect of quinine on the key molecules of the above inflammatory signalings and podocyte functions in high glucose-cultured MPC cells. In summary, we demonstrated that activation of TAS2R4 signaling alleviated the podocyte injury caused by chronic high glucose, and inhibition of NF-κB p65 and NLRP3 inflammasome mediated the protective effects of TAS2R4 activation on podocytes. Moreover, activation of TAS2R4 signaling could be an important strategy for prevention and treatment of diabetic kidney disease.
PubMed: 38942091
DOI: 10.1016/j.bcp.2024.116392 -
ACS Applied Materials & Interfaces Jun 2024Membranous nephropathy (MN) is a common immune-mediated glomerular disease that requires the development of safe and highly effective therapies. Celastrol (CLT) has...
Membranous nephropathy (MN) is a common immune-mediated glomerular disease that requires the development of safe and highly effective therapies. Celastrol (CLT) has shown promise as a therapeutic molecule candidate, but its clinical use is currently limited due to off-target toxicity. Given that excess levels of reactive oxygen species (ROS) contributing to podocyte damage is a key driver of MN progression to end-stage renal disease, we rationally designed ROS-responsive cationic polymeric nanoparticles (PPS-CPNs) with a well-defined particle size and surface charge by employing poly(propylene sulfide)-polyethylene glycol (PPS-PEG) and poly(propylene sulfide)-polyethylenimine (PPS-PEI) to selectively deliver CLT to the damaged glomerulus for MN therapy. Experimental results show that PPS-CPNs successfully crossed the fenestrated endothelium, accumulated in the glomerular basement membrane (GBM), and were internalized by podocytes where rapid drug release was triggered by the overproduction of ROS, thereby outperforming nonresponsive CLT nanotherapy to alleviate subepithelial immune deposits, podocyte foot process effacement, and GBM expansion in a rat MN model. Moreover, the ROS-responsive CLT nanotherapy was associated with significantly lower toxicity to major organs than free CLT. These results suggest that encapsulating CLT into PPS-CPNs can improve efficacy and reduce toxicity as a promising treatment option for MN.
PubMed: 38940537
DOI: 10.1021/acsami.4c04345 -
Cureus May 2024Membranous nephropathy (MN) is a significant cause of nephrotic syndrome in non-diabetic adults. It can be primary, attributed to autoantibodies targeting podocyte...
Membranous nephropathy (MN) is a significant cause of nephrotic syndrome in non-diabetic adults. It can be primary, attributed to autoantibodies targeting podocyte antigens, or secondary to various disorders. Although rare, nerve epidermal growth factor-like 1 (NELL-1)-associated MN presents diagnostic and management challenges. Thrombotic complications such as renal vein thrombosis (RVT) are recognized but less reported, especially in NELL-1-positive MN. We report a 43-year-old male with NELL-1-positive MN complicated by acute kidney injury (AKI) due to bilateral RVT, treated successfully with thrombolysis. Histopathological analysis confirmed MN with specific immunohistochemical staining for NELL-1. Treatment included immunosuppressive therapy and tailored anticoagulation. This case emphasizes recognizing thrombotic complications in MN, particularly in NELL-1-positive cases. Further research is needed to explore serum anti-NELL-1 antibodies as biomarkers and optimal anticoagulation strategies in MN patients at risk of thrombotic events to improve outcomes and guide personalized management.
PubMed: 38939287
DOI: 10.7759/cureus.61230 -
BioImpacts : BI 2024Urinary extracellular vesicles (uEVs) can be considered biomarkers of kidney diseases. EVs derived from podocytes may reflect podocyte damage in different glomerular...
INTRODUCTION
Urinary extracellular vesicles (uEVs) can be considered biomarkers of kidney diseases. EVs derived from podocytes may reflect podocyte damage in different glomerular diseases. IgA nephropathy (IgAN) is one of the most common forms of glomerulonephritis (GN) characterized by proteinuria and hematuria. This study aimed to analyze the uEVs of IgAN patients to understand the pathophysiological processes of the disease at the protein level.
METHODS
Patients with GN [biopsy-proven IgAN (n = 16) and membranous glomerulonephritis (MGN, n = 16)], and healthy controls (n = 16) were included in this study. The uEVs were extracted, characterized, and analyzed to evaluate the protein levels of candidate markers of IgAN, including vasorin precursor, aminopeptidase N, and ceruloplasmin by western-blot analysis.
RESULTS
Higher levels of both podocytes and EVs-related proteins were observed in the pooled urine samples of GN patients compared to the healthy controls. In IgAN patients, uEV-protein levels of vasorin were statistically lower while levels of ceruloplasmin were significantly higher compared to MGN ( = 0.002, = 0.06) and healthy controls, respectively ( = 0.020, = 0.001).
CONCLUSION
Different levels of the studied proteins in uEVs may indicate podocyte injury and represent a direct association with the pathology of IgAN and MGN.
PubMed: 38938751
DOI: 10.34172/bi.2023.29981 -
BMC Nephrology Jun 2024To investigate the expression and significance of Fractalkine (CX3CL1, FKN) in serum and renal tissue of myeloperoxidase and anti-neutrophil cytoplasmic antibody...
OBJECTIVE
To investigate the expression and significance of Fractalkine (CX3CL1, FKN) in serum and renal tissue of myeloperoxidase and anti-neutrophil cytoplasmic antibody associated vasculitis (MPO-AAV) rats.
METHODS
Thirty Wistar-Kyoto (WKY) rats were randomly divided into: Control group, MPO-AAV group (400 µg/kg MPO mixed with Freund's complete adjuvant i.p), MPO-AAV + Anti-FKN group (400 µg/kg MPO mixed with Freund's complete adjuvant i.p), anti-FKN group (1 µg/ rat /day, i.p) after 6 weeks. MPO-AAV associated glomerulonephritis model was established by intraperitoneal injection of MPO + Freund's complete adjuvant with 10 mice in each group. The concentration of MPO-ANCA and FKN in serum was detected by Enzyme-linked immunosorbent assay (ELISA). Hematoxylin-eosin (HE) staining was used to detect pathological changes of kidney tissue. Western blot and immunofluorescence staining were used to detect the expression and localization of FKN protein in kidney tissue. Renal function test indicators: 24-hour urinary protein (UAER), blood urea nitrogen (BUN), serum creatinine (Scr). The expression levels of p65NF-κB and IL-6 was detected by Immunohistochemical assays.
RESULTS
Compared with the control group, the serum MPO-ANCA antibody expression level in the MPO-AAV group was significantly increased (P < 0.01), and the contents of UAER, BUN and Scr were significantly up-regulated at 24 h (P < 0.01). Compared with the control group, the glomeruli in the MPO-AAV group had different degrees of damage, infiltration of inflammatory cell, and membrane cell hyperplasia and renal tubule edema. Compared with the control group, rats in the MPO-AAV group had significantly higher levels of FKN in serum and renal tissues (P < 0.01), and high expression of p65NF-κB and IL-6 in renal tissues (P < 0.01) (P < 0.05), whereas anti-FKN reversed the expression of the above factors. In MPO-AAV renal tissue, FKN was mainly expressed in the cytoplasm of renal tubular epithelial cells and glomerular podocytes. In addition, the contents of 24 h UAER, BUN and Scr of renal function in MPO-AAV rats were significantly decreased (P < 0.01) and the damage of renal tissue was significantly ameliorated after the administration of antagonistic FKN.
CONCLUSION
FKN may play a key role in the pathogenesis of MPO-AAV associated glomerulonephritis.
Topics: Animals; Chemokine CX3CL1; Glomerulonephritis; Rats; Peroxidase; Rats, Inbred WKY; Male; Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis; Kidney; Antibodies, Antineutrophil Cytoplasmic; Transcription Factor RelA
PubMed: 38937701
DOI: 10.1186/s12882-024-03565-3 -
Nature Communications Jun 2024Recent studies have shown the crucial role of podocyte injury in the development of diabetic kidney disease (DKD). Deubiquitinating modification of proteins is widely...
Recent studies have shown the crucial role of podocyte injury in the development of diabetic kidney disease (DKD). Deubiquitinating modification of proteins is widely involved in the occurrence and development of diseases. Here, we explore the role and regulating mechanism of a deubiquitinating enzyme, OTUD5, in podocyte injury and DKD. RNA-seq analysis indicates a significantly decreased expression of OTUD5 in HG/PA-stimulated podocytes. Podocyte-specific Otud5 knockout exacerbates podocyte injury and DKD in both type 1 and type 2 diabetic mice. Furthermore, AVV9-mediated OTUD5 overexpression in podocytes shows a therapeutic effect against DKD. Mass spectrometry and co-immunoprecipitation experiments reveal an inflammation-regulating protein, TAK1, as the substrate of OTUD5 in podocytes. Mechanistically, OTUD5 deubiquitinates K63-linked TAK1 at the K158 site through its active site C224, which subsequently prevents the phosphorylation of TAK1 and reduces downstream inflammatory responses in podocytes. Our findings show an OTUD5-TAK1 axis in podocyte inflammation and injury and highlight the potential of OTUD5 as a promising therapeutic target for DKD.
Topics: Podocytes; Animals; MAP Kinase Kinase Kinases; Diabetic Nephropathies; Mice; Inflammation; Ubiquitination; Humans; Mice, Knockout; Male; Mice, Inbred C57BL; Phosphorylation; Diabetes Mellitus, Experimental; Ubiquitin-Specific Proteases; HEK293 Cells; Deubiquitinating Enzymes
PubMed: 38937512
DOI: 10.1038/s41467-024-49854-1 -
Journal of Clinical Apheresis Jun 2024Membranous nephropathy is the most common cause of nephrotic syndrome (NS) in non-diabetic adults; in 80% of patients it is idiopathic (PMN). PMN has an autoimmune...
Membranous nephropathy is the most common cause of nephrotic syndrome (NS) in non-diabetic adults; in 80% of patients it is idiopathic (PMN). PMN has an autoimmune pathogenesis, 70%-85% of patients have increased titer of antibodies to the podocyte membrane antigen PLA2R. The etiological, prognostic and predictive role of the Ab anti-PLA2R is demonstrated. Standard therapy consists in anti-CD20 monoclonal antibody rituximab (RTX) combined with steroids or immunosuppressants according to the risk of progressive loss of kidney function. The immunosuppressive therapies are potentially associated to severe adverse events that lead to protocol suspension. Given their pivotal pathogenetic role, serum clearance of anti-PLA2R with plasmapheresis could have a beneficial impact on NS, particularly in patients not requiring or tolerating standard therapies. In this series, we present three cases of PMN anti-PLA2R related treated with a RTX plus plasmapheresis approach and demonstrate its overall effective role on anti-PLA2R titer and clinical outcomes.
Topics: Humans; Plasmapheresis; Glomerulonephritis, Membranous; Receptors, Phospholipase A2; Rituximab; Male; Middle Aged; Female; Adult; Autoantibodies; Immunosuppressive Agents
PubMed: 38934513
DOI: 10.1002/jca.22134