Renal epithelial sodium channel(ENaC) plays a crucial role in maintaining homeostasis and sodium absorption.While insulin participates in controlling sodium transport across the renal epithelium,the underlying molecul...Renal epithelial sodium channel(ENaC) plays a crucial role in maintaining homeostasis and sodium absorption.While insulin participates in controlling sodium transport across the renal epithelium,the underlying molecular mechanism remain unclear.In this study,we found that insulin increased the expression and function of alphaepithelial sodium channel(α-ENaC) as well as phosphorylation of cofilin,a family of actin-binding proteins which disassembles actin filaments,in mouse cortical collecting duct(mpkCCDc14) cells.The wild-type(WT)cofilin and its constitutively phosphorylated form(S3 D),but not its constitutively non-phosphorylable form(S3 A),contributed to the elevated expression on α-ENaC.Overexpression of 14-3-3ε,β,or y increased the expression of α-ENaC and cofilin phosphorylation,which was blunted by knockdown of 14-3-3ε,β,or y.Moreover,it was found that insulin increased the interaction between cofilin and 14-3-3 isoforms,which indicated relevance of 14-3-3 isoforms with cofilin.Furthermore,LIMK1/SSH1 pathway was involved in regulation of cofilin and α-ENaC expression by insulin.The results from this work indicate that cofilin participates in the regulation of α-ENaC by interaction with 14-3-3 isoforms.展开更多
BACKGROUND Phosphatidylinositol-3,4,5-trisphosphate dependent Rac exchange factor 1(PREX1)was reported to be overexpressed in some cancers and involved in cancer development,but its expression and significance in gast...BACKGROUND Phosphatidylinositol-3,4,5-trisphosphate dependent Rac exchange factor 1(PREX1)was reported to be overexpressed in some cancers and involved in cancer development,but its expression and significance in gastric cancer remain unclear.AIM To evaluate the expression of PREX1 in gastric cancer and its significance in the development of gastric cancer,especially to evaluate the potential mechanism of PREX1 in gastric cancer.METHODS Bioinformatic analysis was performed in order to examine the expression of PREX1 in gastric cancer.The relationship between the survival rate of gastric cancer patients and PREX1 expression was assessed by Kaplan Meier portal.The Gene Set Enrichment Analysis and the correlation between PREX1 and transforming growth factor(TGF)β1 pathway-related mediators were evaluated by cBioPortal for Cancer Genomics.Western blotting and reverse transcriptase polymerase chain reaction assay were used to test the role of TGFβ1 on the expression of PREX1.Western blotting and dual-luciferase reporter system was used to evaluate the effect of PREX1 on the activation of TGFβ1 pathway.Wound healing and Transwell assay were used to assess the effect of PREX1 on the metastasis activity of gastric cancer cells.RESULTS PREX1 was overexpressed in the gastric tumors,and the expression levels were positively associated with the development of gastric cancer.Also,the high expression of PREX1 revealed poor prognosis,especially for those advanced and specific intestinal gastric cancer patients.PREX1 was closely involved in the positive regulation of cell adhesion and positively correlated with TGFβ1-related mediators.Furthermore,TGFβ1 could induce the expression of PREX1 at both the protein and mRNA level.Also,PREX1 could activate the TGFβ1 pathway.The induced PREX1 could increase the migration and invasion activity of gastric cancer cells.CONCLUSION PREX1 is overexpressed in gastric cancer,and the high level of PREX1 predicts poor prognosis.PREX1 is closely associated with TGFβsignaling and promotes the metastasis of gastric cancer cells.展开更多
Weaning stress can cause tight junctions damage and intestinal permeability enhancement,which leads to intestinal imbalance and growth retardation,thereby causing damage to piglet growth and development.Spermine can r...Weaning stress can cause tight junctions damage and intestinal permeability enhancement,which leads to intestinal imbalance and growth retardation,thereby causing damage to piglet growth and development.Spermine can reduce stress.However,the mechanism of spermine modulating the intestinal integrity in pigs remains largely unknown.This study aims to examine whether spermine protects the intestinal barrier integrity of piglets through ras-related C3 botulinum toxin substrate 1(Rac1)/phospholipase C-g1(PLC-γ1)signaling pathway.In vivo,80 piglets were categorised into 4 control groups and 4 spermine groups(10 piglets per group).The piglets were fed with normal saline or spermine at 0.4 mmol/kg BW for 7 h and 3,6 and 9 d.In vitro,we investigated whether spermine protects the intestinal barrier after a tumor necrosis factor a(TNF-a)challenge through Rac1/PLC-γ1 signaling pathway.The in vivo study found that spermine supplementation increased tight junction protein mRNA levels and Rac1/PLC-γ1 signaling pathway gene expression in the jejunum of piglets.The serum D-lactate content was significantly decreased after spermine supplementation(P<0.05).The in vitro study found that 0.1 mmol/L spermine increased the levels of tight junction protein expression,Rac1/PLC-γ1 signaling pathway and transepithelial electrical resistance,and decreased paracellular permeability(P<0.05).Further experiments demonstrated that spermine supplementation enhanced the levels of tight junction protein expression,Rac1/PLC-γ1 signaling pathway and transepithelial electrical resistance,and decreased paracellular permeability compared with the NSC-23766 and U73122 treatment with spermine after TNF-a challenge(P<0.05).Collectively,spermine protects intestinal barrier integrity through Rac1/PLC-γ1 signaling pathway in piglets.展开更多
基金supported by the National Natural Science Foundation of China to XL(Grant No.81870467 and No.81670619)。
文摘Renal epithelial sodium channel(ENaC) plays a crucial role in maintaining homeostasis and sodium absorption.While insulin participates in controlling sodium transport across the renal epithelium,the underlying molecular mechanism remain unclear.In this study,we found that insulin increased the expression and function of alphaepithelial sodium channel(α-ENaC) as well as phosphorylation of cofilin,a family of actin-binding proteins which disassembles actin filaments,in mouse cortical collecting duct(mpkCCDc14) cells.The wild-type(WT)cofilin and its constitutively phosphorylated form(S3 D),but not its constitutively non-phosphorylable form(S3 A),contributed to the elevated expression on α-ENaC.Overexpression of 14-3-3ε,β,or y increased the expression of α-ENaC and cofilin phosphorylation,which was blunted by knockdown of 14-3-3ε,β,or y.Moreover,it was found that insulin increased the interaction between cofilin and 14-3-3 isoforms,which indicated relevance of 14-3-3 isoforms with cofilin.Furthermore,LIMK1/SSH1 pathway was involved in regulation of cofilin and α-ENaC expression by insulin.The results from this work indicate that cofilin participates in the regulation of α-ENaC by interaction with 14-3-3 isoforms.
文摘BACKGROUND Phosphatidylinositol-3,4,5-trisphosphate dependent Rac exchange factor 1(PREX1)was reported to be overexpressed in some cancers and involved in cancer development,but its expression and significance in gastric cancer remain unclear.AIM To evaluate the expression of PREX1 in gastric cancer and its significance in the development of gastric cancer,especially to evaluate the potential mechanism of PREX1 in gastric cancer.METHODS Bioinformatic analysis was performed in order to examine the expression of PREX1 in gastric cancer.The relationship between the survival rate of gastric cancer patients and PREX1 expression was assessed by Kaplan Meier portal.The Gene Set Enrichment Analysis and the correlation between PREX1 and transforming growth factor(TGF)β1 pathway-related mediators were evaluated by cBioPortal for Cancer Genomics.Western blotting and reverse transcriptase polymerase chain reaction assay were used to test the role of TGFβ1 on the expression of PREX1.Western blotting and dual-luciferase reporter system was used to evaluate the effect of PREX1 on the activation of TGFβ1 pathway.Wound healing and Transwell assay were used to assess the effect of PREX1 on the metastasis activity of gastric cancer cells.RESULTS PREX1 was overexpressed in the gastric tumors,and the expression levels were positively associated with the development of gastric cancer.Also,the high expression of PREX1 revealed poor prognosis,especially for those advanced and specific intestinal gastric cancer patients.PREX1 was closely involved in the positive regulation of cell adhesion and positively correlated with TGFβ1-related mediators.Furthermore,TGFβ1 could induce the expression of PREX1 at both the protein and mRNA level.Also,PREX1 could activate the TGFβ1 pathway.The induced PREX1 could increase the migration and invasion activity of gastric cancer cells.CONCLUSION PREX1 is overexpressed in gastric cancer,and the high level of PREX1 predicts poor prognosis.PREX1 is closely associated with TGFβsignaling and promotes the metastasis of gastric cancer cells.
基金This research is supported by the Sichuan Science and Technology Program(No.2020YJ0398).
文摘Weaning stress can cause tight junctions damage and intestinal permeability enhancement,which leads to intestinal imbalance and growth retardation,thereby causing damage to piglet growth and development.Spermine can reduce stress.However,the mechanism of spermine modulating the intestinal integrity in pigs remains largely unknown.This study aims to examine whether spermine protects the intestinal barrier integrity of piglets through ras-related C3 botulinum toxin substrate 1(Rac1)/phospholipase C-g1(PLC-γ1)signaling pathway.In vivo,80 piglets were categorised into 4 control groups and 4 spermine groups(10 piglets per group).The piglets were fed with normal saline or spermine at 0.4 mmol/kg BW for 7 h and 3,6 and 9 d.In vitro,we investigated whether spermine protects the intestinal barrier after a tumor necrosis factor a(TNF-a)challenge through Rac1/PLC-γ1 signaling pathway.The in vivo study found that spermine supplementation increased tight junction protein mRNA levels and Rac1/PLC-γ1 signaling pathway gene expression in the jejunum of piglets.The serum D-lactate content was significantly decreased after spermine supplementation(P<0.05).The in vitro study found that 0.1 mmol/L spermine increased the levels of tight junction protein expression,Rac1/PLC-γ1 signaling pathway and transepithelial electrical resistance,and decreased paracellular permeability(P<0.05).Further experiments demonstrated that spermine supplementation enhanced the levels of tight junction protein expression,Rac1/PLC-γ1 signaling pathway and transepithelial electrical resistance,and decreased paracellular permeability compared with the NSC-23766 and U73122 treatment with spermine after TNF-a challenge(P<0.05).Collectively,spermine protects intestinal barrier integrity through Rac1/PLC-γ1 signaling pathway in piglets.
