摘要
Objective To explore the regulatory role of fat mass and obesity-associated protein(FTO)and serine-threonine kinase protein kinase D2(PRKD2)in progression of diabetic kidney disease(DKD)and its regulatory mechanisms.Methods DKD model in vitro was constructed by podocytes(MPC5 cells)treated with high glucose(HG,35 mmol/L glucose)for 24 h.HG-induced MPC5 cells were transfected with FTO overexpression vector(pcDNA-FTO)and PRKD2 overexpression vector(pcDNA-PRKD2),or empty vector.The overexpression efficiency of FTO and PRKD2 were detected with RT-qPCR.MeRIP was used to detect the N6-methyladenosine(m6A)modification level of PRKD2 mRNA.The activity of Caspase-3 and the secretion of IL-6,TNF-α and monocyte chemotactic protein-1(MCP-1)were detected by ELISA.Cell apoptosis rate was analyzed by flow cytometry.The protein levels of FTO and PRKD2,as well as the key proteins in SIRT1/HIF-1α pathway,were evaluated by Western blot.Pearson analysis was used to analyze the correlation between FTO levels and PRKD2 levels.Results Compared with the control group without HG-induction,the protein expression of FTO(0.51±0.04 vs 1.00±0.03)and PRKD2(0.45±0.03 vs 1.01±0.04)was significantly down-regulated in HG-induced podocytes,and the differences were statistically significant(t=13.17,16.76,all P＜0.001).FTO protein levels were positively correlated with PRKD2 protein levels in HG-induced podocytes(r2=0.705 1,P＜0.001).Compared with the vector group,the m6A levels of PRKD2 mRNA(0.56±0.09 vs 1.01±0.13)in the pcDNA-FTO group were decreased,and the mRNA levels of PRKD2(3.16±0.14 vs 1.03±0.02)were increased,with significant differences(t=51.37,11.82,all P＜0.001).Compared with the control group(IL-6:512.76±61.85 pg/ml,TNF-α:28.17±2.83 pg/ml,MCP-1:157.31±17.69 pg/ml)and the vector group(IL-6:498.41±87.51 pg/ml,TNF-α:26.35±5.47 pg/ml,MCP-1:165.52±16.87 pg/ml),the secretion of IL-6(301.86±21.85 pg/ml),TNF-α(11.06±4.12 pg/ml)and MCP-1(81.45±9.03 pg/ml)were significantly decreased in the pcDNA-PRKD2 group,and the differences were statistically significant(F=7.51,10.47,61.97,all P＜0.01).Compared with the control group(caspase-3 activity:689.65±79.5 U/L,cell apoptosis:22.31%±2.69%)and the vector group(Caspase-3 activity:715.91±113.58 U/L,cell apoptosis:21.07%±3.28%),Caspase-3 activity(437.64±104.76 U/L)and the rate of apoptosis(8.41%±3.15%)were significantly decreased in the pcDNA-PRKD2 group,and the differences were statistically significant(F=2.35,79.13,all P＜0.01).Compared with the control group(SIRT1:1.01±0.05,HIF-1α:1.03±0.07)and the vector group(SIRT1:0.97±0.05,HIF-1α:1.02±0.03),SIRT1 protein levels(3.51±0.15)were increased and HIF-1α protein levels(0.37±0.07)were decreased in the pcDNA-PRKD2 group,and the differences were statistically significant(F=31.54,8.31,all P＜0.01).Conclusion FTO-mediated and m6A-modified PRKD2 suppresses inflammation and apoptosis in HG-induced podocytes through the SIRT1/HIF-1 pathway.
摘要
Objective To investigate the effects of icariin on high glucose-induced autophagy and apoptosis of podocytes,and the regulating effects on mammalian target of rapamycin(mTOR)/serine-threonine kinase(Akt)/cyclic adenosine monophosphate response element binding protein(CREB)pathway.Methods The mouse podocytes MPC5 were taken and divided into five groups:normal control group(5.5 mmol·L-1 glucose),high glucose group(30 mmol·L-1 glucose),icariin group(30 mmol·L-1glucose+5 μmol·L-1icariin),GDC-0349 group(30 mmol·L-1glucose+50 μmol·L-1 GDC-0349),icariin+GDC-0349 group(30 mmol·L-1 glucose+5 μmol·L-1 icariin+50 μmol·L-1 GDC-0349).Cultured for 48 hours,the tetramethylazozolium salt method was used to detect the viability of MPC5 cells;acridine orange staining was used to observe the autophagy of MPC5 cells;apoptosis of MPC5 cells was detected by flow cytometry;Western blotting was used to detect the expression of autophagy[microtubule associated protein one light chain 3(LC3)II,LC3Ⅰ,autophagy-related protein(Beclin-1)],apoptosis[Bcl-2 related X protein(Bax),B cell lymphoma-2(Bcl-2)]and mTOR/Akt/CREB pathway-related proteins of MPC5 cells.Results Compared with the normal control group,the cell viability,expression levels of Bcl-2,phosphorylated mTOR(p-mTOR)/mTOR,phosphorylated Akt(p-Akt)/Akt,phosphorylated CREB(p-CREB)/CREB protein of MPC5 cells in the high glucose group were significantly decreased(P＜0.05),the autophagy ability was enhanced,the autophagosome showed orange fluorescence,and the apoptosis rate,LC3Ⅱ/LC3Ⅰ,Beclin-1,Bax protein expression levels were significantly increased(P＜0.05).Compared with the high glucose group,the cell viability,LC3Ⅱ/LC3Ⅰ,Beclin-1,Bcl-2,p-mTOR/mTOR,p-Akt/Akt,p-CREB/CREB protein expression levels of MPC5 cells in icariin group were significantly increased,the autophagy ability was further enhanced,the number of autophagosomes was increased,the autophagosomes showed brick red fluorescence(P＜0.05),the apoptosis rate and Bax protein expression level were significantly decreased(P＜0.05),and the cell viability,LC3Ⅱ/LC3Ⅰ,Beclin-1,Bcl-2,p-mTOR/mTOR,p-Akt/Akt and p-CREB/CREB proteins expression levels of MPC5 cells in GDC-0349 group were significantly decreased,the autophagy ability was weakened,the number of autophagosomes was reduced,the autophagosomes showed orange fluorescence(P＜0.05),and the apoptosis rate and Bax protein expression level were significantly increased(P＜0.05);icariin+GDC-0349 could reverse the effect of icariin on high glucose induced MPC5 cells(P＜0.05).Conclusion Icariin promotes elevated glucose-induced podocyte autophagy and inhibits apoptosis by activating the mTOR/Akt/CREB pathway.
摘要
Objective:To investigate the efficacy and mechanism of canagliflozin (Cana) in the treatment of high glucose-induced human podocyte (HPC) injury.Methods:The HPCs were divided into 5 groups: normal glucose group (NG group), mannitol group (MA group), high glucose group (HG group), Cana low dose (0.3 μmol/L) group and Cana high dose (1.0 μmol/L) group. Western blotting was used to examine the protein expressions of membrane-associated guanylate kinase inverted-2 (MAGI2), podocyte-associated protein nephrin, sodium-glucose transporter 2 (SGLT2), NOD-like receptor thermal protein domain associated protein 3 (NLRP3), apoptosis- associated speck-like protein containing a CARD (ASC), and cleaved-caspase1 in podocytes. Phalloidin staining of F-actin in podocytes was used to observe cytoskeletal injury. Intracellular reactive oxygen species (ROS) level of HPC was detected by the 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) probe. Levels of interleukin (IL)-18 and IL-1β in culture medium of podocytes were detected by enzyme-linked immunosorbent assay (ELISA).Results:(1) Compared with the NG group, the protein expressions of MAGI2 and nephrin decreased (both P<0.01), the protein expression of SGLT2 increased ( P<0.01), the changes of cell morphology and cytoskeleton remodeling were obvious, intracellular ROS level increased ( P<0.01), while NLRP3, ASC and cleaved-caspase1 protein expressions decreased in the HG group (all P<0.01). The results of ELISA showed that IL-18 and IL-1β concentrations were higher in the HG group (both P<0.05). (2) Compared with the HG group, in the Cana groups, MAGI2 and nephrin expressions up-regulated (both P<0.01), the changes of cell morphology and cytoskeleton remodeling were alleviated. Meanwhile the Cana groups showed decreased SGLT2 expression ( P<0.05), lower ROS level, down- regulated NLRP3, ASC, cleaved-caspase1 expressions (all P<0.01), and decreased concentrations of IL-18 and IL-1β in culture medium of podocytes (both P<0.05). Conclusion:Cana can improve high glucose-induced injury and inflammation in human podocyte, possibly due to the repression of the ROS/NLRP3 signaling pathway.
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With the development of neonatal intensive care, both the live birth rate and survival rate of preterm infants, especially in extremely preterm infants, have escalated. However, the long-term adverse prognosis of preterm infants became increasingly conspicuous. In the field of kidney disease, the existing clinical data have substantiated a higher susceptibility to chronic kidney disease (CKD) development during childhood or adulthood in preterm and low-birth-weight infants when compared with full-term infants. This suggests that preterm and/or low birth weight increases the risk for long-term CKD. Nonetheless, little attention has been paid to long-term CKD associated with preterm and/or low birth weight and the mechanism involved in this process is unknown. Current studies have suggested that reduced nephron and podocyte depletion are involved in this process, but detailed molecular mechanism remains inadequate. Therefore, this article reviews the research progress of long-term CKD correlated with preterm and/or low birth weight.
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Objective To investigate the effects of adipocyte plasma membrane-associated protein(APMAP)over-expression on glomerular podocyte injury in adriamycin(ADR)nephropathy.Methods The rat model of adriamy-cin nephropathy was constructed by tail vein injection of adriamycin,the expression of APMAP and NF-κB p65 in renal tissue was measured by immunohistochemistry.A mouse glomerular podocytes MPC-5 cell line with APMAP gene over-expression was constructed,then podocyocytes injury model was induced by 0.5 μmol/L ADR and trea-ted with NF-κB signaling pathway activator CU-T12-9.The proliferation of cells was checked by CCK-8.The activity of lactate dehydrogenase(LDH)was determined by ELISA.The apoptosis of podocytes was determined by flow cytometry.Western blot was used to detect protein expressions of NF-κB p65,p-NF-κB p65 and TNF-α.Results APMAP was expressed in kidney tissue of doxorubicin nephropathy rats at a low level,while NF-κB p65 was significantly high expressed(P＜0.05).Over-expression of APMAP increased proliferation of MPC-5 cells and decreased LDH activity,apoptosis rate,and also down-regulated protein expression of NF-κB p65,P-NF-κB p65 and TNF-α under ADR exposure(P＜0.05).However,combined treatment with CU-T12-9 significantly inhibited the ameliorative effect of APMAP over-expression on the damage of MPC-5 cells exposed to ADR.Conclusions The over-expression of APMAP can inhibit ADR-induced glomerular podocyte injury,and its mechanism might be related to the inhibition of NF-κB signaling pathway.
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Objective:To investigate the changes of podocyte circadian rhythm in the high-glucose environment and diabetic nephropathy (DN) mouse model and the protective effect of melatonin on podocyte injury in DN.Methods:Primary podocytes were cultured in vitro and divided into 3 groups: control group, high glucose (30 mmol/L) group and high glucose (30 mmol/L) treated with melatonin (0.1 mmol/L or 0.5 mmol/L) group. The podocytes were collected every 4 hours for 24 hours, synchronized with dexamethasone (100 nmol/L) for 2 hours, which was recorded as zeitgeber time 0 point. Male C57BL/6J mice aged 6-8 weeks and weighing about 20 g were randomly (randomized block) assigned to three groups: control group, DN (high-fat diet+streptozotocin 120 mg/kg intravenously injected) group, and DN (high-fat diet+streptozotocin 120 mg/kg intravenously) treated with melatonin (20 mg/kg intragastric treatment) group (melatonin group). Real-time quantitative PCR was used to detect the mRNA levels of rhythm genes in podocytes. Western blotting was used to detect the protein expression levels of circadian clock genes (Clock and Bmal1), podocyte marker proteins (Nephrin, Synaptopodin, WT1, and Desmin) and autophagy-related proteins (Beclin1, LC3Ⅱ/Ⅰ and P62). Immunofluorescence staining was used to detect the protein expression level of WT1, and immunohistochemistry was used to analyze the protein expression levels of P62 and cleaved-caspase-3 in renal tissues of mice. The pathological changes of renal glomerulus were observed under electron microscope. Results:(1) Dexamethasone reseted the expression and rhythmic oscillation of circadian clock genes in podocytes. The circadian rhythmic oscillations of Clock and Ck1e mRNA in the high glucose group were flattened compared to the control group, and the circadian rhythmic oscillations in Clock and Ck1e mRNA expression were partial recovery in high glucose treated with melatonin group (all P<0.05). (2) Compared with the control group, the protein expression levels of Nephrin, Synaptopodin and WT1 were lower while Desmin was higher in the high glucose group (all P<0.05). The protein expression levels of Nephrin, Synaptopodin and WT1 were higher and the protein expression level of Desmin was lower in the high glucose treated with melatonin (0.5 mmol/L) group compared with the high glucose group (all P<0.05). (3) The invivo experimental results showed that compared with the DN group, melatonin group had higher protein expression levels of glomerular Nephrin and WT1, and lower urinary albumin/creatinine ratio, width of foot process and thickness of glomerular basement membrane (all P<0.05). The protein expression levels of Beclin1 and LC3Ⅱ/Ⅰ in the DN group were lower than those in the control group, and the protein expression level of P62 was higher than that in the control group (all P<0.05). Compared with the DN group, the protein expression levels of Beclin1 and LC3Ⅱ/Ⅰ in the melatonin group were significantly higher, and the protein expression level of P62 was lower (all P<0.05). Conclusions:Melatonin can partially restore the circadian rhythm of clock genes in high-glucose environment, improve autophagy and alleviate injury in podocytes.
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Objective:To investigate the potential function and related mechanism of microRNA-223 (miRNA-223) in the podocyte pyroptosis of hepatitis B virus (HBV)-associated glomerulonephritis induced by HBV X protein (HBx).Methods:HBx-overexpressing lentivirus was transfected into human renal podocytes to mimic the pathogenesis of HBV-GN. Real-time fluorescence quantitative PCR and Western blotting experiments were used to detect the mRNA and protein expression of pyroptosis-related proteins [nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3), apoptosis-associated speck-like protein containing a CARD (ASC) and caspase-1], and inflammatory factors (interleukin-1β and interleukin-18), respectively.TUNEL staining and flow cytometry were used to detect the number of pyroptosis cells. Immunofluorescence staining was used to detect the expression of podocytes biomarkers desmin and nephrin; Hoechst 33342 staining was used to observe the morphological and quantitative changes of podocyte nuclei. Enzyme-linked immunosorbent assay was used to measure caspase-1 activity. The dual luciferase reporter gene assay was used to verify the downstream target of miRNA-223. Podocytes were divided into the following nine groups: control group (no special treatment), empty plasmid group (transfected with empty plasmid), HBx overexpression group (transfected with HBx overexpression lentivirus), HBx overexpression+miRNA-223 mimic group (transfected with HBx overexpression lentivirus and miRNA-223 mimic), HBx overexpression+miRNA-223 inhibitor group (transfected with HBx overexpression lentivirus and miRNA-223 inhibitor), HBx overexpression+miRNA-223 mimic+NLRP3 group (transfected with HBx overexpression lentivirus, miRNA-223 mimic and NLRP3 overexpression plasmid), HBx overexpression+miRNA-223 mimic+ NLRP3 siRNA group (transfected with HBx overexpression lentivirus, miRNA-223 mimic and NLRP3 siRNA), HBx overexpression+miRNA-223 inhibitor+NLRP3 group (transfected with HBx overexpression lentivirus, miRNA-223 inhibitor and NLRP3 overexpression plasmid), HBx overexpression+miRNA-223 inhibitor+NLRP3 siRNA group (transfected with HBx overexpression lentivirus, miRNA-223 inhibitor and NLRP3 siRNA).Results:miRNA-223 was down-regulated in HBx overexpression group compared with the control group ( P < 0.05). TUNEL and immunofluorescence staining showed that NLRP3 knockdown attenuated podocyte injury and pyroptosis induced by HBx overexpression ( P < 0.05). Dual luciferase reporter gene assay demonstrated that NLRP3 was one of the downstream targets of miRNA-223. Rescue experiments revealed that NLRP3 overexpression weakened the protective effect of miRNA-223 in podocyte injury ( P < 0.05). The addition of miRNA-223 mimic and NLRP3 siRNA decreased the expression of NLRP3 inflammasome and cytokines, and reduced the number of pyroptosis cells induced by HBx overexpression (all P < 0.05); The addition of miRNA-223 inhibitor and NLRP3 overexpression plasmid significantly increased the expression of NLRP3 inflammasome and cytokines, caspase-1 activity, and the number of pyroptosis cells (all P < 0.05). Conclusion:HBx may promote podocyte pyroptosis of HBV-GN via downregulating miRNA-223 targeting NLRP3 inflammasome, suggesting that miRNA-223 is expected to be a potential target for the treatment of HBV-GN.
摘要
Podocyte infolding glomerulopathy (PIG) is a pathologic type of podocyte glomerulopathy reported recently. The characteristic is that the ultrastructure related to podocytes, such as microspheres and microtubules, are folded into the glomerular basement membrane (GBM) under electron microscope. At present, there are few reports about this disease at home and abroad, and most of them are concentrated in Japan. The clinical characteristics and pathogenesis of PIG are still unclear. In this paper, we report a case of clinical manifestations of nephrotic syndrome, renal biopsy indicated PIG, after the treatment of glucocorticoid, hydroxychloroquine and tacrolimus, the patient's clinical symptoms were relieved and urinary protein decreased.
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Aim To explore the protective effect of Yishen Huashi Granule (YSHS) on streptozotocin (STZ) - indueed diabetes nephropathy (DN) in mice and its possible mechanism. Methods The STZ induced DN mice model was established, which was randomly divided into model group, YSHS group and YAP inhibitor Vertepofin group, and the eontrol group was also established. The intervention was started eight weeks after the successful modeling with the course of four weeks. Urine protein concentration before and after intervention in each group as well as serum creatinine (Scr) and blood urea nitrogen (Bun) levels after intervention were measured. After the treatment, the mice were sacrificed, and the pathological changes of glomeruli were observed by light microscope HE staining. The protein expression of YAP, p-YAP S127 and CTGF were detected by Western blot, and the mRNA expressions of YAP, CTGF and podocyte functional proteins nephrin, podophyxin and WT1 were detected by RT-PCR. Results The biochemical indexes of YSHS group were better than those of model group, and HE staining showed that the pathological injury of glomeruli was improved. In the model group the protein expression of YAP, p-YAP (S127) and CTGF as well as the mRNA expression of YAP and CTGF increased, while the mRNA expression of nephrin, podocalyxin and WT1 decreased. After YSHS treatment, the protein expression of YAP, p-YAP S127, CTGF and the mRNA expression of YAP and CTGF decreased, while the mRNA expression of nephrin, podocalyxin and WT1 increased. Conclusions YSHS can reduce urinary protein, protect renal function and alleviate glomerular pathological injury in DN mice. Its possible mechanism may be related to the down-regulation of YAP in renal tissue, the reduction of CTGF expression level and the up-regulation of podocyte protein mRNA expression.
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ObjectiveTo investigate the intervention effect of Danggui Buxuetang on oxidative stress and inflammatory response in diabetic kidney disease （DKD） rats from its improvement of podocyte mitochondrial dysfunction. MethodSD rats were randomly divided into the control group and modeling group， and the ones in the latter group rats were fed a high-glucose and high-fat diet and then intraperitoneally injected with a small dose of streptozotocin （STZ） for inducing type 2 diabetes. The successfully modeled rats were randomized into the model group， high- and low-dose （1.44 and 0.72 g·kg-1） Danggui Buxuetang groups， and irbesartan （0.017 g·kg-1）group and gavaged with the corresponding drugs， while those in the normal and model groups with an equal volume of normal saline. After 20 weeks of drug intervention， the urinary microalbumin-to-urine creatinine ratio （UACR） and serum malondialdehyde （MDA） content and manganese superoxide dismutase （MnSOD） activity in each group were measured. The pathological changes in renal tissue were observed by Masson trichrome staining， and periodic acid-silver metheramine （PASM） staining， followed by the observation of ultrastructural changes in podocytes under the transmission electron microscope （TEM）. The expression level of reactive oxygen species （ROS） in rat kidney tissue was detected using a fluorescent probe dihydroethidium （DHE）. The protein expression levels of peroxisome proliferator-activated receptor γ -coactivator -1α （PGC-1α）， nucleotide-binding domain like receptor protein 3 （NLRP3）， and Wilms tumor protein-1 （WT-1） were measured by immunohistochemistry （IHC）， and the expression levels of NLRP3， interleukin-1β （IL-1β），and WT-1 in podocytes by immunofluorescence （IF） assay. The mRNA expression levels of PGC-1α and NLRP3 in the renal tissues were determined by real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）， and the protein expression levels of PGC-1α， MnSOD， NLRP3， and IL-1β were assayed by Western blot. ResultCompared with the normal group， the model group exhibited elevated UACR and MDA content， weakened MnSOD activity （P<0.01）， glomerular hypertrophy， thickened basement membrane， mesangial hyperplasia， increased extracellular matrix， K-W nodules， podocyte mitochondrial swelling， disordered mitochondrial cristae， foot process fusion or loss， vacuolization， increased ROS （P<0.01）， enhanced NLRP3 and IL-1β but diminished WT-1 expression in podocytes， down-regulated PGC-1α mRNA expression （P<0.01） and PGC-1α and MnSOD protein expression （P<0.01）， and up-regulated NLRP3 mRNA expression and NLRP3 and IL-1β protein expression （P<0.01）. Compared with the model group， Danggui Buxuetang high-dose group significantly decreased UACR and MDA， enhanced MnSOD activity （P<0.05， P<0.01）， improved renal histopathology and podocyte mitochondrial ultrastructure， decreased ROS （P<0.05， P<0.01） and NLRP3 and IL-1β expression in podocytes， enhanced WT-1 expression in podocytes， up-regulated the mRNA and protein levels of PGC-1α and MnSOD， and down-regulated the mRNA and protein levels of NLRP3 and IL-1β （P<0.05， P<0.01）. ConclusionDanggui Buxuetang alleviates oxidative stress， reduces inflammatory response， protects kidney， and delays the progression of DKD possibly by improving the mitochondrial dysfunction in podocytes of DKD rats.
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ObjectiveTo observe the effect of Danggui Buxuetang on the podocyte injury and receptor-interacting protein kinase 1/receptor-interacting protein kinase3/mixed lineage kinase domain-like protein （RIPK1/RIPK3/MLKL） signaling pathway in diabetic kidney disease （DKD） ratsand to explore its possible mechanism against DKD. MethodEight of the 50 SD rats were randomly classified intoa normal group， and the remaining were fed a high-glucose and high-fat diet for six weeks and then intraperitoneally injected with 0.035 g·kg-1streptozotocin （STZ） for inducing type 2 diabetes. After successful modeling，they were randomized into the model group，high- and low-dose （1.44，0.72 g·kg-1） Danggui Buxuetang groups， and irbesartan （0.017 g·kg-1）group. After 20 weeks of drug intervention， the fasting blood glucose （FBG）， kidney index （KI），and urinary microalbumin-to-urine creatinine ratio （UACR）were detected in each group. The pathological changes in renal tissue were observed by hematoxylin-eosin （HE） staining， followed by the observation of ultrastructural changes in podocytes under the transmission electron microscope. The levels of tumor necrosis factor-α （TNF-α） and interleukin-6 （IL-6） in renal tissue of rats were determined by enzyme-linked immunosorbent assay （ELISA）， and the protein expression levels of RIPK1， RIPK3， and MLKL in rat kidney tissue by immunohistochemistry. The apoptosis rate of podocytes was detected by in situ nick end-labeling （TUNEL） assay. The mRNA expression levels of RIPK1， RIPK3， and MLKL in kidney tissue of rats were measured by real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）， and the protein expression levels of RIPK， RIPK3， and MLKL and podocyte marker Wilms tumor protein-1 （WT-1） in rat kidney tissue were assayed by Western blot. ResultCompared with the normal group， the model group exhibited elevated FBG， UACR， and KI （P<0.01）， glomerular hypertrophy， thickened basement membrane， increased extracellular matrix， mesangial hyperplasia， foot process fusion or loss， enhanced apoptosis in renal tissue， up-regulated TNF-α and IL-6 levels （P<0.01） and RIPK1/RIPK3/MLKL mRNA and protein expression （P<0.01）， and down-regulated WT-1 protein expression. Compared with the model group， Danggui Buxuetang high-dose group significantly reduced the levels of FBG， UACR， and KI， improved renal histopathology， podocyte loss， and apoptosis in renal tissue， down-regulated TNF-α and IL-6 levels and RIPK1/RIPK3/MLKL mRNA and protein expression （P<0.05， P<0.01）， and up-regulated WT-1 protein expression. ConclusionDanggui Buxuetang alleviates podocyte injury and delays the development of DKD possibly by regulating the RIPK1/RIPK3/MLKL signaling pathway.
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ObjectiveTo explore the molecular mechanism of Yishen Tongluo prescription in inhibiting the apoptosis of glomerular podocytes in rats with membranous nephropathy （MN） based on the miR-514a-5p/tumor necrosis factor superfamily member 15 （TNFSF15） signaling pathway. MethodEighty SD rats were pre-immunized and injected with cationized bovine serum albumin （C-BSA） into the tail vein for inducing MN， and the successfully modeled MN rats were randomly divided into the model group， high-， middle-， and low-dose （26.44， 13.22， 6.61 g·kg-1） Yishen Tongluo prescription groups， and benazepril （10 mg·kg-1） group， with 10 rats in each group， and another 20 healthy rats were classified into the normal group. Rats in each group were gavaged with the corresponding drugs， once a day， for four successive weeks. After the administration， the 24-hour urine total protein （UTP） level， serum total cholesterol （TC）， triglyceride （TG）， albumin （ALB）， creatinine （SCr）， and urea nitrogen （BUN） levels were measured. The miR-514a-5p and TNFSF15 mRNA expression levels in the rat kidney tissue were detected by real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）， and the expression levels of podocyte marker proteins Nephrin， Podocin， Podocalyxin， Synaptopodin， TNFSF15， and podocyte apoptosis-related proteins B lymphocytoma-2 （Bcl-2）-related X protein （Bax）， Bcl-2-associated death promoter （BAD） protein， and B-cell lymphoma-extra large （Bcl-XL） by immunohistochemistry （IHC）. Western blot was used to detect the expression levels of TNFSF15， Bax， BAD， Bcl-2， and BCL-XL in the rat kidney tissue. The apoptosis rate of rat kidney tissue was measured using the in situ end labeling method （Tunnel）. ResultCompared with the normal group， the level of miR-514a-5p in the kidney tissue was significantly reduced （P<0.05）， and the TNFSF15 mRNA expression was significantly increased （P<0.05）. The expression levels of podocyte marker proteins Nephrin， Podocin， Podocalyxin， and Synaptopodin were down-regulated （P<0.05）. The protein expression levels of TNFSF15， Bax， and BAD were increased （P<0.05）， whereas the Bcl-2 and Bcl-XL protein expression levels were decreased （P<0.05）. The number of apoptotic cells diminished significantly （P<0.05）. Compared with the model group， the level of miR-514a-5p in the kidney tissue was significantly increased （P<0.05）， while the level of TNFSF15 mRNA was significantly decreased （P<0.05）. The expression levels of podocyte marker proteins Nephrin， Podocin， podocalyxin， and Synaptopodin were up-regulated （P<0.05）， whereas the TNFSF15， Bax， and BAD protein expression levels were down-regulated （P<0.05）. Bcl-2 and Bcl-XL protein expression levels rose （P<0.05）. The number of apoptotic cells significantly decreased （P<0.05）. ConclusionYishen Tongluo prescription reduces the apoptosis of rat kidney podocytes and alleviates the kidney injury of MN rats through the miR-514a-5p/TNFSF15 signaling pathway.
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Diabetic kidney disease (DKD) is one of the serious complications of diabetes mellitus, and it has become the leading cause of chronic renal failure in China. Podocytes are highly differentiated epithelial cells and are the important part of the glomerular filtration barrier. Apoptosis and shedding of podocytes, foot process fusion and decreased expression of slit membrane proteins can lead to proteinuria, which in turn affects the progression of DKD. Autophagy is an important process for eukaryotic cells to degrade cytoplasmic proteins and organelles,the increase of autophagy level helps to reduce podocytes damage. Endoplasmic reticulum stress (ERS) is the accumulation of misfolded proteins in cells. It allows the cells into stress state, and may be able to regulate cell damage in both directions. Autophagy and ERS are regulated by multiple signaling pathways and are considered to be closely related to the occurrence and development of DKD. This article explained some pathways and the role of podocyte autophagy and ERS in DKD, and the interaction between podocyte autophagy and ERS, which providing some potential targets for the treatment of DKD by interfering with podocyte autophagy and ERS.
摘要
Objective:To investigate the protective effect and potential mechanisms of microRNA-26a-5p (miR-26a-5p) on podocyte injury in diabetic kidney disease (DKD).Methods:(1) In vivo experiment: Four-week-old db/db mice were divided into db/db group, db/db+agomir-NC group and db/db+miR-26a-5p agomir group according to random number table method, with 10 mice in each group, and 10 db/m mice of the same week-old were set as normal control group. At the age of 10 weeks, pathological changes were observed through light and electron microscopy. Kidney weight/body weight (KW/BW), urinary albumin to creatinine ratio (ACR), fasting blood glucose (FBG) and other biochemical indicators were also detected. The position and expression of miR-26a-5p in kidney tissue were determined through fluorescence in situ hybridization and quantitative real-time PCR, while the expressions of transient receptor potential cation channel-6 (TRPC6) and Nephrin in kidney tissue were determined by Western blotting and immunohistochemistry. (2) In vitro experiment: The immortalized mouse podocytes (MPC5) were divided into 5 groups: normal glucose group, high mannitol group, high glucose group, high glucose+miR-26a-5p mimic group, and high glucose+mimic-NC group. The expressions of miR-26a-5p, TRPC6 and Nephrin were detected. Luciferase reporter assay was conducted to research the relationship of miR-26a-5p and TRPC6. Results:(1) In vivo experiment: Compared with db/m group, db/db mice exhibited lower KW/BW and disrupted conditions of ACR, FBG, total cholesterol, triglycerides and low density lipoprotein cholesterol (all P<0.01). Increased glomeruli volume, more extracellular matrix deposition, thicker basement membrane and more foot process fusion were observed by light and electron microscope. Increased expression of TRPC6 protein as well as decreased expression of Nephrin protein and miR-26a-5p were detected in kidney tissues of db/db mice ( P<0.05). Compared with db/db+agomir-NC group, db/db mice transfected by miR-26a-5p agomir exhibited less albuminuria, with less protein expression of TRPC6 and more Nephrin in kidney tissue (all P<0.05). (2) In vitro experiment: Compared with normal glucose group, high glucose-treated podocytes exhibited increased expression of TRPC6 ( P<0.05), as well as decreased expression of Nephrin ( P<0.05) and miR-26a-5p ( P<0.01). Compared with high glucose+mimic-NC group, lower expression of TRPC6 and higher expression of Nephrin were detected in podocytes transfected by miR-26a-5p mimic (both P<0.05). Luciferase reporter assay confirmed that miR-26a-5p could regulate the expression of TRPC6 precisely. Conclusions:The expression of miR-26a-5p in podocytes is down-regulated in the context of high glucose and miR-26a-5p protects podocytes from injury via inhibiting the expression of TRPC6 in DKD.
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To explore a new underlying molecular mechanism of Huangkui Extract Powder (HKEP) in the alleviation of diabetic nephropathy (DN). Murine immortalized podocytes were divided into (i) normal glucose (NG, 5.6 mM), (ii) NG + HKEP (0.45 g/L), (iii) HG, and (iv) HG + HKEP (0.45 g/L) groups. MTT assay and flow cytometry were used to detect the podocyte proliferation, apoptosis and cell cycle. Cell viability was inhibited, and apoptosis increased in(iii) HG group compared with (i) NG group (p<0.05). mRNA and protein expression of nephrin and podocin significantly decreased in (iii) HG group compared with (i) NG group (p<0.05). When compared with (iii) HG group, (iv) HG + HKEP group had higher cell viability, lower apoptotic rate and higher mRNA and protein expression of nephrin and podocin (p<0.05). HKEP can attenuate HG-induced podocyte damage, which may be one of the mechanisms of HKEP for attenuating DN.
Explorar un nuevo mecanismo molecular subyacente del extracto del polvo de Huangkui (HKEP) en el alivio de la nefropatía diabética (ND). Los podocitos murinos inmortalizados se dividieron en (i) grupos de glucosa normal (NG, 5,6 mM), (ii) NG + HKEP (0,45 g/L), (iii) HG y (iv) HG + HKEP (0,45 g/L). Se utilizaron el ensayo MTT y la citometría de flujo para detectar la proliferación de podocitos, la apoptosis y el ciclo celular. La viabilidad celular se inhibió y la apoptosis aumentó en el grupo (iii) HG en comparación con el grupo (i) NG (p<0,05). La expresión de ARNm y proteínas de nefrina y podocina disminuyó significativamente en el grupo (iii) HG en comparación con el grupo (i) NG (p<0,05). En comparación con el grupo (iii) HG, el grupo (iv) HG + HKEP tuvo una mayor viabilidad celular, una tasa de apoptosis más baja y una expresión de ARNm y proteínas más altas de nefrina y podocina (p<0,05). HKEP puede atenuar el daño de los podocitos inducido por HG, que puede ser uno de los mecanismos de HKEP para atenuar la DN.
Subject(s)
Plant Extracts/administration & dosage , Diabetic Nephropathies/drug therapy , Podocytes/drug effects , Powders , Plant Extracts/genetics , Cell Cycle , Blotting, Western , Apoptosis/drug effects , Cell Culture Techniques , Reverse Transcriptase Polymerase Chain Reaction , Glucose摘要
Objective:To investigate the role of mitofusion 2 (Mfn2) in high glucose (HG)-induced endoplasmic reticulum stress (ERS) and apoptosis of podocytes.Methods:(1) Streptozocin was used to induce a diabetes mellitus (DM) rat model. Renal histopathological changes in rats were observed by HE staining. Expression of Mfn2 and CCAAT/enhancer-binding protein homologous protein (CHOP) in glomeruli was observed by immunohistochemistry. Protein levels of Mfn2, protein kinase RNA-like ER kinase (PERK), phospho(p)-PERK, and CHOP in glomeruli were analyzed by Western blotting. (2) Conditionally immortalized human podocytes (HPC) cultured in vitro were divided into control, mannitol (MA) and HG groups. Expression of Mfn2 was observed by immunofluorescence. Protein levels of Mfn2, p-PERK, PERK and CHOP in HPC were analyzed by Western blotting. Podocyte apoptosis in each group was evaluated by flow cytometry with AnnexinⅤ-PE/7AAD double staining method. (3) HPC were divided into control, HG, HG+Mfn2-Myc plasmid-transfected and HG+control plasmid-transfected groups. Protein levels of Mfn2, p-PERK, PERK and CHOP in HPC were analyzed by Western blotting. Expression of CHOP was observed by immunofluorescence. Mitochondrial membrane potential in each group was observed by mitochondrial membrane potential assay kit with JC-1. Podocyte apoptosis in each group was evaluated by flow cytometry with AnnexinⅤ-PE/7AAD double staining method. Results:(1) Compared with the control group, the glomerular mesangial matrix of the DM group rats was significantly proliferated, and the expression of Mfn2 was down-regulated with the expression of ERS-related proteins p-PERK/PERK and CHOP up-regulated (all P<0.05). (2) Compared with the control group, Mfn2 was down-regulated and p-PERK/PERK and CHOP were up-regulated in HPC of HG group (all P<0.05). Apoptosis of HPC was also increased in HG group. There was no significant difference in the above indicators between the control group and the mannitol group (all P>0.05). (3) Compared with the HG group, mitochondrial membrane potential of HPC was alleviated and apoptosis of HPC was decreased in HG+Mfn2-Myc plasmid-transfected group ( P<0.05). P-PERK/PERK and CHOP were down-regulated in HG+Mfn2-Myc plasmid-transfected group (both P<0.05). There was no significant difference in the above indicators between the HG group and the HG+control plasmid-transfected group (all P>0.05). Conclusions:Mfn2 down-regulation in HG-stimulated podocytes may induce ERS to increase apoptosis of podocytes. Up-regulation of Mfn2 can alleviate the HG-induced ERS and apoptosis in podocytes.
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Objective:To evaluate the effect of proprotein convertase subtilisin/kexin type 9 (PCSK9) on lipid homeostasis and cellular injury of podocytes, and to clarify its mechanism.Methods:Twelve-week old C57BL/6 wild-type mice ( n=10) and PCSK9 knockout ( PCSK9 KO) mice ( n=10) were selected as the animal models. The renal tissues were taken after perfusion through heart. Mouse podocytes were transfected with PCSK9 siRNA to downregulate PCSK9 expression. BODIPY 493/503 staining was performed for evaluating lipid accumulation, and standard transmission electron microscopy (TEM) was used to observe the foot process of podocytes, the shape of mitochondria and lipid droplet in podocytes. TUNEL staining was carried out to evaluate cell apoptosis in glomerulus. The parameters about mitochondria function (key enzymes such as PGC-1α, CPT-1 and Acox-1) and apoptosis were quantified through qPCR and western blotting. Results:The lipid accumulation in glomerulus of PCSK9 KO mice were more serious than controls. The expression of PGC-1α protein and PGC-1α, CPT-1 and Acox-1 mRNA in PCSK9 KO mouse kidney tissues were decreased than controls (all P<0.05), and mitochondria swelling and cristae disappearance in podocytes of PCSK9 KO mice were observed. In PCSK9 KO group, the foot process of podocytes partially fused and disappeared, and the apoptosis index increased compared with the control group ( P<0.05). In vitro, compared with the control group, the lipid accumulation was more significant, transcription level of key enzymes related to mitochondrial function was decreased, mitochondrial structure was damaged and the apoptosis index was increased in cultured podocyte PCSK9 siRNA group (all P<0.05). Conclusions:PCSK9 is involved in the lipid homeostasis of podocytes. The decrease of PCSK9 results in the increase of intracellular lipid accumulation, accompanied by the mitochondrial structure damage and disfunction of podocytes, and leads to cell apoptosis.
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OBJECTIVES@#High fat-induced podocyte injury is one of the important factors leading to obesity related nephropathy (ORG), but the mechanism is not clear. This study aims to explore the mechanism of period circadian clock 3 (PER3) in the oxidative stress and inflammation induced by palmitic acid (PA) in podocytes.@*METHODS@#The C57BL/6J mice were fed with chow and high-fat diet for 16 weeks. The PER3 expression in kidney tissues were detected in the normal body weight group and the obesity group. The PER3 mRNA and protein expression were detected after the podocytes were induced with different concentrations (0, 50, 150 and 300 μmol/L) of PA for 48 h. The PER3 mRNA and protein expression were detected after the podocytes were induced with 150 μmol/L PA for 0, 24, 36, and 48 h. Triglyceride (TG) levels were examined in the PA group, the adenovirus (ad)-PER3+PA group, and the siRNA-PER+PA group after the podocytes were transfected by Ad-PER3 or small interfering RNA (siRNA)-PER3 for 48 h and subsequently were induced with 150 μmol/L PA for 48 h. The differential gene expression was detected using RNA sequencing (RNA-seq) after podocytes were transfected by siRNA-PER3 (siRNA-PER3 group) and siRNA-control (siRNA-control group), respectively. The mRNA levels of nephrin, podocin, podocalyxin, podoplanin, superoxide dismutase 1 (SOD1), glutathione peroxidase 1 (GPX1), catalase (CAT), and the levels of malondialdehyde (MDA), glutathione (GSH), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β) and interleukin-2 (IL-2) were detected after podocytes were transfected with Ad-PER3 or Ad-control for 48 h and then they were induced by 150 μmol/L PA for 48 h.@*RESULTS@#The PER3 was down-regulated in the obesity group compared with the normal body weight group (@*CONCLUSIONS@#PER3 can decrease the PA-induced oxidative stress and inflammatory factor secretion via inhibiting the lipogenesis in podocytes.
Subject(s)
Animals , Mice , Circadian Clocks , Mice, Inbred C57BL , Oxidative Stress , Palmitic Acid/toxicity , Podocytes/metabolism摘要
Aim To explore the regulatory mechanism of berberine in the high glucose (HG) -induced podocyte ferroptosis. Methods Western blot and R T - qPCR were used to detect the changes of G P X 4, PTGS2, ACSL4, podocin, and desmin at different time (0 h, 6 h, 12 h, 24 h, 36 h) of HG stimulation, and the relative expression of Nrf2, HO-1, GPX4 and podocin under HG after treated with berberine. The proliferation of podocytes stimulated by HG at different time points was observed by EdU staining. The therapeutic effect of berberine on podocyte damage was screened by CCK-8, and the effect of berberine on the level of oxidative stress in HG-induced podocytes were measured by fluorescence inverted microscope, GSH and GSSG kits. In addition, transmission electron microscopy was employed to observe the ultrastructural characteristics of podocytes in each group. Results The expression of podocin and GPX4 was significantly reduced at 24 h, and the mRNA levels of ACSL4 and PTGS2 were significantly up-regulated. Berberine could notably increase the expression of Nrf2, HO-1, GPX4 and podocin, and reduce the levels of PTGS2 and ACSL4. Moreover, berberine significantly improved the levels of ROS and GSH in podocytes under HG conditions, thereby alleviating membrane blistering, mitochondrial shrinkage and other morphological changes of HG-induced podocytes. Conclusions In this study, the number of podocytes decreases, which is a death mode different from autophagy and apoptosis, that is, ferroptosis. Berberine can alleviate the occurrence of this phenomenon by mediating the Nrf2/ H0-1/GPX4.
摘要
Objective:To explore the protective effect and the mechanism of Danggui Shaoyaosan（DSS） on angiotensin Ⅱ （AngⅡ）/transient receptor potential cation channel 6 （TRPC6） pathway in nephrotic syndrome （NS） rats. Method:In animal experiments， doxorubicin （4 mg·kg<sup>-1</sup> for the 1<sup>st</sup> week and 2 mg·kg<sup>-1</sup> for the 2<sup>nd</sup> week） was injected twice to the tail vein of rats to induce NS model in 160 rats， which were then randomly divided into model group （normal saline）， losartan group （30 mg·kg<sup>-1</sup>·d<sup>-1</sup>）， and low-（4.3 g·kg<sup>-1</sup>·d<sup>-1</sup>）， medium-（8.6 g·kg<sup>-1</sup>·d<sup>-1</sup>）， and high-dose （17.2 g·kg<sup>-1</sup>·d<sup>-1</sup>） DSS groups. Besides， a normal group was also set. After intervention for four weeks， ultrastructure changes of the kidney were identified by transmission electron microscopy （TEM）. The 24-hour urine protein was detected by kits. Radioimmunoassay was used to detect the content of AngⅡ and Calcineurin （CaN） in plasma. Western blot was used to detect the protein expression of TRPC6， angiotensin Ⅱ type 1 receptor （AT1R）， podocyte slit diaphragm-specific protein （Nephrin）， and cysteine-aspartic acid protease-3 （Caspase-3） in the renal cortex. Immunohistochemistry was used to detect the expression of TRPC6 and AT1R in the slit diaphragm. In cell experiments， AngⅡ stimulated MPC5 podocytes. The cells were randomly divided into a normal group， an AngⅡ group， an AngⅡ+SAR7334 （TRPC6-specific inhibitor） group， an AngⅡ+5%DSS group， an AngⅡ+10%DSS group， and an AngⅡ+15%DSS group. Western blot was used to detect the protein expression of TRPC6， AT1R， Nephrin， and Caspase-3 in podocytes. Result:Compared with the normal group， the model group showed increased 24-hour urine protein content （<italic>P</italic><0.01） and AngⅡ and CaN in plasma （<italic>P</italic><0.01）， incomplete glomerular structure， the extensive fusion of podocyte process with elevated fusion rate （<italic>P</italic><0.01）， increased expression distribution of AT1R and TRPC6 in the renal cortex， and up-regulated protein expression of AT1R， TRPC6， and Caspase-3 in renal tissues （<italic>P</italic><0.01）， and reduced Nephrin protein expression （<italic>P</italic><0.01）. Compared with model group， the losartan group and the high-dose DSS group exhibited decreased 24-hour urine protein content （<italic>P</italic><0.01） and the content of AngⅡ and CaN in plasma （<italic>P</italic><0.01）， improved glomerular structure， reduced fusion rate of podocyte process （<italic>P</italic><0.01）， diminished expression distribution of TRPC6 and AT1R in the renal cortex， declining protein expression of AT1R， TRPC6 and Caspase-3 in renal tissues （<italic>P</italic><0.01）， and elevated Nephrin protein expression （<italic>P</italic><0.01）. Additionally， compared with the normal podocytes， AngⅡ-stimulated podocytes showed increased protein expression of AT1R， TRPC6 and Caspase-3 （<italic>P</italic><0.01）， and decreased expression of Nephrin （<italic>P</italic><0.01）. Compared with the AngⅡ group， the AngⅡ+SAR7334 group displayed reduced protein expression of AT1R， TRPC6， and Caspase-3 （<italic>P</italic><0.01） and increased protein expression of Nephrin （<italic>P</italic><0.01）. Conclusion:DSS can improve the pathological characteristics of NS presumedly by inhibiting the interaction between AngⅡ and TRPC6 in podocytes and improving the structural integrity of podocytes to repair the damage of glomerular molecular barrier and slow down the progression of NS-induced proteinuria.