Objective To investigate the effect of triptolide(TPL)on renal interstitial fibrosis in mice with unilateral ureteral obstruction(UUO)and its mechanism.Methods Six male C57BL/6J mice were randomly selected as the sham group,and 12 mice with UUO modeling were randomly divided into the model group(UUO)and the triptolide group(TPL).Changes in serum creatinine(SCr),blood urea nitrogen(BUN),and body weight were compared among the groups.Renal tissue specimens were collected at 14 d after UUO for HE and Masson staining.Immunohistochemistry staining was performed to observe the expression of α-smooth muscle actin(α-SMA)and fibronectin(Fn)in kidney tissues.Western blotting analysis was used to detect the protein expression levels of nucleotide combined with structure of oligomerization domain receptor protein 3(NLRP3),GSDMD,cGSDMD,IL-1β and IL-18.Results At week 1,the body weight of mice in the UUO and TPL groups significantly decreased compared with that in the sham group(P＜0.05).Body weight reduced in the TPL group compared with that in the Sham group at week 2(P＜0.01).There was no significant difference in body weight between the TPL and UUO groups.BUN levels did not differ significantly between the three groups.Compared with the sham group,the SCr level in the UUO group significantly increased[(15.680±1.508)μmol/L](P＜0.01).A reduction in SCr level was observed following TPL administration[(12.550±3.004)μmol/L](P＜0.05).HE staining showed that the renal tubules of mice in the UUO group were significantly dilated and atrophic,with interstitial edema and increased inflammatory cell infiltration,while the pathological damage of renal tissues was significantly alleviated after TPL treatment.Masson staining revealed that interstitial collagen deposition significantly increased in the UUO group(36.350±5.183)％(P＜0.01)and reduced after TPL administration(20.820±3.290)％(P＜0.01).Immunohistochemistry results demonstrated that the IOD levels of α-SMA(1.233±0.045)and Fn(1.337±0.045)were higher in UUO group mice than in the sham group,while the IOD levels of α-SMA(1.047±0.025)and Fn(1.113±0.021)were lower in the TPL group than in the UUO group(P＜0.05).Western blotting analysis indicated that the expression levels of NLRP3,cGSDMD,IL-1β and IL-18 in the UUO group mice were higher than those in the sham group,while the protein expression levels of the above-mentioned indicators significantly decreased after TPL treatment(P＜0.05).Conclusion TPL ameliorates renal interstitial fibrosis in mice with UUO by inhibiting NLRP3-mediated pyroptosis.

Objective To investigate the effect of triptolide(TPL)on renal interstitial fibrosis in mice with unilateral ureteral obstruction(UUO)and its mechanism.Methods Six male C57BL/6J mice were randomly selected as the sham group,and 12 mice with UUO modeling were randomly divided into the model group(UUO)and the triptolide group(TPL).Changes in serum creatinine(SCr),blood urea nitrogen(BUN),and body weight were compared among the groups.Renal tissue specimens were collected at 14 d after UUO for HE and Masson staining.Immunohistochemistry staining was performed to observe the expression of α-smooth muscle actin(α-SMA)and fibronectin(Fn)in kidney tissues.Western blotting analysis was used to detect the protein expression levels of nucleotide combined with structure of oligomerization domain receptor protein 3(NLRP3),GSDMD,cGSDMD,IL-1β and IL-18.Results At week 1,the body weight of mice in the UUO and TPL groups significantly decreased compared with that in the sham group(P＜0.05).Body weight reduced in the TPL group compared with that in the Sham group at week 2(P＜0.01).There was no significant difference in body weight between the TPL and UUO groups.BUN levels did not differ significantly between the three groups.Compared with the sham group,the SCr level in the UUO group significantly increased[(15.680±1.508)μmol/L](P＜0.01).A reduction in SCr level was observed following TPL administration[(12.550±3.004)μmol/L](P＜0.05).HE staining showed that the renal tubules of mice in the UUO group were significantly dilated and atrophic,with interstitial edema and increased inflammatory cell infiltration,while the pathological damage of renal tissues was significantly alleviated after TPL treatment.Masson staining revealed that interstitial collagen deposition significantly increased in the UUO group(36.350±5.183)％(P＜0.01)and reduced after TPL administration(20.820±3.290)％(P＜0.01).Immunohistochemistry results demonstrated that the IOD levels of α-SMA(1.233±0.045)and Fn(1.337±0.045)were higher in UUO group mice than in the sham group,while the IOD levels of α-SMA(1.047±0.025)and Fn(1.113±0.021)were lower in the TPL group than in the UUO group(P＜0.05).Western blotting analysis indicated that the expression levels of NLRP3,cGSDMD,IL-1β and IL-18 in the UUO group mice were higher than those in the sham group,while the protein expression levels of the above-mentioned indicators significantly decreased after TPL treatment(P＜0.05).Conclusion TPL ameliorates renal interstitial fibrosis in mice with UUO by inhibiting NLRP3-mediated pyroptosis.

【Objective】 To explore the role and mechanism of TRPC6 in apoptosis of glomerular mesangial cells (HBZY-1) induced by endoplasmic reticulum stress (ERS). 【Methods】 The experiment groups were classified as follows: normal control (NC), thapsigargin (TG), TG+SKF96365, and TG+TRPC6 siRNA groups. Transcription and protein expressions of TRPC6 and ERS related proteins (GRP78 and Caspase12) were detected by qRT-PCR and Western blotting. Additionally, cell apoptosis was measured by flow cytometry and Hoechst33258. Finally, Fluo-4 AM Ca²⁺ imaging technique was used to determine changes of intracellular calcium ( [Ca²⁺] i) by laser scanning confocal microscope. 【Results】 Morphological changes of apoptotic cells were characterized by nuclear enrichment or nuclear fragmentation, and the apoptosis rate was increased after TG stimulation. The expressions of TRPC6 and ERS related proteins (GRP78 and Caspase12) were elevated in TG group compared with NC group (P<0.05). Pre-incubation of HBZY-1 cells with SKF96365 and TRPC6 siRNA decreased cell apoptosis (P<0.05). The entry of [Ca²⁺] i also increased after TG stimulation (P<0.05). The expressions of TRPC6, GRP78 and Caspase12 were downregulated compared with TG group after treatment with SKF96365 and TRPC6 siRNA accompanied by decreased [Ca²⁺] i (P<0.05). 【Conclusion】 Taken together, this study suggests that inhibition of TRPC6 can alleviate TG-induced HBZY-1 cell apoptosis.

【Objective】 To explore the role and mechanism of TRPC in promoting extracellular matrix (ECM) deposition in rat glomerular mesangial cells (HBZY-1). Methods Immunofluorescence staining was performed to observe the distribution and expression of TRPC1 and TRPC6 in HBZY-1 cells. After AngⅡ stimulation, qRT-PCR and Western blotting were used to detect the mRNA and protein expressions of Gαq/PLCβ4/TRPC signaling pathway main proteins and ECM deposition indicators (α-SMA, collagenⅢ and fibronectin). By silencing the expressions of TRPC1 and TRPC6 by RNA interference, the expressions of ECM deposition indicators were detected. Changes in [Ca²⁺]i influx were determined through Fluo-4AM Ca²⁺ imaging. 【Results】 Both TRPC1 and TRPC6 were expressed in HBZY-1, and were mainly located in cell membrane and cytoplasm. After AngⅡ stimulation, Gαq/PLCβ4/TRPC signaling pathway was activated, and the mRNA and protein expressions of Gαq, PLCβ4, TRPC1 and TRPC6 were all increased (P<0.05). [Ca²⁺]i influx also increased (P<0.01), and the mRNA and protein expressions of ECM deposition indicators (α-SMA, ColⅢ and Fn) were upregulated (P<0.05). Silencing the expressions of TRPC1 and TRPC6 by RNA interference led to decreased [Ca²⁺]i influx (P<0.05), and downregulated mRNA and protein expressions of ECM deposition indicators in HBZY-1 cells (P<0.05). The results suggested that inhibition of TRPC expressions could inhibit AngⅡ induced ECM deposition in HBZY-1 cells, which might be associated with decreased [Ca²⁺]i influx. 【Conclusion】 TRPC may be a novel therapeutic target of renal fibrosis.