Glycosylation is a common post-translational modification in eukaryotic cells.It is involved in the production of many biologically active glycoproteins and the regulation of protein structure and function.Core fucosy...Glycosylation is a common post-translational modification in eukaryotic cells.It is involved in the production of many biologically active glycoproteins and the regulation of protein structure and function.Core fucosylation plays a vital role in the immune response.Most immune system molecules are core fucosylated glycoproteins such as complements,cluster differentiation antigens,immunoglobulins,cytokines,major histocompatibility complex molecules,adhesion molecules,and immune molecule synthesis-related transcription factors.These core fucosylated glycoproteins play important roles in antigen recognition and clearance,cell adhesion,lymphocyte activation,apoptosis,signal transduction,and endocytosis.Core fucosylation is dominated by fucosyltransferase 8(Fut8),which catalyzes the addition ofα-1,6-fucose to the innermost GlcNAc residue of N-glycans.Fut8 is involved in humoral,cellular,and mucosal immunity.Tumor immunology is associated with aberrant core fucosylation.Here,we summarize the roles and potential modulatory mechanisms of Fut8 in various immune processes of the gastrointestinal system.展开更多
Background：Core fucosylation （CF）,catalyzed by α-1,6 fucosyltransferase （Fut8） in mammals,plays an important role in pathological processes through posttranslational modification of key signaling receptor protei...Background：Core fucosylation （CF）,catalyzed by α-1,6 fucosyltransferase （Fut8） in mammals,plays an important role in pathological processes through posttranslational modification of key signaling receptor proteins,including transforming growth factor （TGF）-β receptors and platelet-derived growth factor （PDGF） receptors.However,its effect on peritoneal fibrosis is unknown.Here,we investigated its influence on epithelial-mesenchymal transition （EMT） of rat peritoneal mesothelial cells （PMCs） in vitro induced by a high-glucose （HG） culture solution.Methods：Rat PMCs were first cultured in a HG （2.5%） culture solution to observe the CF expression level （fluorescein isothiocyanate-lens culinaris agglutinin）,we next established a knockdown model of rat PMCs in vitro with Fut8 small interfering RNA （siRNA） to observe whether inhibiting CF decreases the messenger RNA （mRNA） expression and protein expression of Fut8 and reverses EMT status.Rat PMCs were randomly divided into control group,mock group （transfected with scrambled siRNA）,Fut8 siRNA group,HG group,HG ＋ mock group,and HG ＋ Fut8 siRNA group.Finally,we examined the activation of TGF-β/Smad2/3 signaling and PDGF/extracellular signal-regulated kinase （ERK） signaling to observe the influence of CF on them.Results：CF,Fut8 mRNA,and protein expression were all significantly upregulated in HG-induced EMT model than those in the control rat PMCs （P 〈 0.05）.Fut8 siRNA successfully blocked CF of TGF-β receptors and PDGF receptors and attenuated the EMT status （E-cadherin and α-SMA and phenotypic changes） in HG-induced rat PMCs.In TGF-β/Smad2/3 signaling,Fut8 siRNA did not suppress the protein expression of TGF-3 receptors and Smad2/3;however,it significantly suppressed the phosphowlation of Smad2/3 （relative expression folds of HG ＋ Fut8 group vs.HG group：7.6 ± 0.4 vs.15.1 ± 0.6,respectively,P 〈 0.05）.In PDGF/ERK signaling,Fut8 siRNA did not suppress the protein expression of PDGF receptors and ERK,but it significantly suppressed the phosphorylation of ERK （relative expression folds of HG ＋ Fut8 group vs.HG group：8.7 ± 0.9 vs.15.6 ± 1.2,respectively,P 〈 0.05）.Blocking CF inactivated the activities of TGF-β and PDGF signaling pathways,and subsequently blocked EMT.Conclusions：These results demonstrate that CF contributes to rat PMC EMT.and that blocking it attenuates EMT.CF regulation is a potential therapeutic target of peritoneal fibrosis.展开更多
It is well documented that the glycosylation of E-cadherin is correlated with cancer metastasis, but whether E- cadherin could be core fucosylated remains largely unknown. We found that E-cadherin was core fucosylated...It is well documented that the glycosylation of E-cadherin is correlated with cancer metastasis, but whether E- cadherin could be core fucosylated remains largely unknown. We found that E-cadherin was core fucosylated in highly metastatic lung cancer cells while absent in lowly metastatic lung cancer cells. Since α-1,6 Fucosyltransferase (α-1,6 FucT) is known to catalyze the reaction of core fucosylation, we investigated the biological function of core fucosylation on E-cadherin by α-1,6 FucT targeted RNAi and transfecting α-1,6 FucT expression vector. As a result, calcium dependent cell-cell adhesion mediated by E-cadherin was strengthened with the reduction of core fucosylation on E- cadherin after RNAi and was weakened with the elevated core fucosylation on E-cadherin after α-1,6 FucT over expression. Our data indicated that α-1,6 FucT could regulate E-cadherin mediated cell adhesion and thus play an important role in cancer development and progression. Computer modeling showed that core fucosylation on E-cadherin could significantly impair three-dimensional conformation of N-glycan on E-cadherin and produce conformational asym- metry so as to suppress the function of E-cadherin. Furthermore, the relationship between the expression of core fucosylated E-cadherin and clinicopathological background of lung cancer patients was explored in lung cancer tissue of patients. It turns out to demonstrate that core fucosylated E-cadherin could serve as a promising prognostic indicator for lung cancer patients.展开更多
基金Supported by the National Natural Science Foundation of China,No.32171279Natural Science Foundation of Liaoning Province,No.2022-BS-254,and No.2022-MS-317the Project of Dalian Medical Science Research,No.2012026.
文摘Glycosylation is a common post-translational modification in eukaryotic cells.It is involved in the production of many biologically active glycoproteins and the regulation of protein structure and function.Core fucosylation plays a vital role in the immune response.Most immune system molecules are core fucosylated glycoproteins such as complements,cluster differentiation antigens,immunoglobulins,cytokines,major histocompatibility complex molecules,adhesion molecules,and immune molecule synthesis-related transcription factors.These core fucosylated glycoproteins play important roles in antigen recognition and clearance,cell adhesion,lymphocyte activation,apoptosis,signal transduction,and endocytosis.Core fucosylation is dominated by fucosyltransferase 8(Fut8),which catalyzes the addition ofα-1,6-fucose to the innermost GlcNAc residue of N-glycans.Fut8 is involved in humoral,cellular,and mucosal immunity.Tumor immunology is associated with aberrant core fucosylation.Here,we summarize the roles and potential modulatory mechanisms of Fut8 in various immune processes of the gastrointestinal system.
基金This work was supported by a grant from the National Natural Science Foundation of China （No. 81530021）.
文摘Background：Core fucosylation （CF）,catalyzed by α-1,6 fucosyltransferase （Fut8） in mammals,plays an important role in pathological processes through posttranslational modification of key signaling receptor proteins,including transforming growth factor （TGF）-β receptors and platelet-derived growth factor （PDGF） receptors.However,its effect on peritoneal fibrosis is unknown.Here,we investigated its influence on epithelial-mesenchymal transition （EMT） of rat peritoneal mesothelial cells （PMCs） in vitro induced by a high-glucose （HG） culture solution.Methods：Rat PMCs were first cultured in a HG （2.5%） culture solution to observe the CF expression level （fluorescein isothiocyanate-lens culinaris agglutinin）,we next established a knockdown model of rat PMCs in vitro with Fut8 small interfering RNA （siRNA） to observe whether inhibiting CF decreases the messenger RNA （mRNA） expression and protein expression of Fut8 and reverses EMT status.Rat PMCs were randomly divided into control group,mock group （transfected with scrambled siRNA）,Fut8 siRNA group,HG group,HG ＋ mock group,and HG ＋ Fut8 siRNA group.Finally,we examined the activation of TGF-β/Smad2/3 signaling and PDGF/extracellular signal-regulated kinase （ERK） signaling to observe the influence of CF on them.Results：CF,Fut8 mRNA,and protein expression were all significantly upregulated in HG-induced EMT model than those in the control rat PMCs （P 〈 0.05）.Fut8 siRNA successfully blocked CF of TGF-β receptors and PDGF receptors and attenuated the EMT status （E-cadherin and α-SMA and phenotypic changes） in HG-induced rat PMCs.In TGF-β/Smad2/3 signaling,Fut8 siRNA did not suppress the protein expression of TGF-3 receptors and Smad2/3;however,it significantly suppressed the phosphowlation of Smad2/3 （relative expression folds of HG ＋ Fut8 group vs.HG group：7.6 ± 0.4 vs.15.1 ± 0.6,respectively,P 〈 0.05）.In PDGF/ERK signaling,Fut8 siRNA did not suppress the protein expression of PDGF receptors and ERK,but it significantly suppressed the phosphorylation of ERK （relative expression folds of HG ＋ Fut8 group vs.HG group：8.7 ± 0.9 vs.15.6 ± 1.2,respectively,P 〈 0.05）.Blocking CF inactivated the activities of TGF-β and PDGF signaling pathways,and subsequently blocked EMT.Conclusions：These results demonstrate that CF contributes to rat PMC EMT.and that blocking it attenuates EMT.CF regulation is a potential therapeutic target of peritoneal fibrosis.
基金supported by the National Nature Science Foundation of China(No.30070183,No.30470398)Key Subject Foundation of Shanghai Municipal Education Committee(No.B9808010).
文摘It is well documented that the glycosylation of E-cadherin is correlated with cancer metastasis, but whether E- cadherin could be core fucosylated remains largely unknown. We found that E-cadherin was core fucosylated in highly metastatic lung cancer cells while absent in lowly metastatic lung cancer cells. Since α-1,6 Fucosyltransferase (α-1,6 FucT) is known to catalyze the reaction of core fucosylation, we investigated the biological function of core fucosylation on E-cadherin by α-1,6 FucT targeted RNAi and transfecting α-1,6 FucT expression vector. As a result, calcium dependent cell-cell adhesion mediated by E-cadherin was strengthened with the reduction of core fucosylation on E- cadherin after RNAi and was weakened with the elevated core fucosylation on E-cadherin after α-1,6 FucT over expression. Our data indicated that α-1,6 FucT could regulate E-cadherin mediated cell adhesion and thus play an important role in cancer development and progression. Computer modeling showed that core fucosylation on E-cadherin could significantly impair three-dimensional conformation of N-glycan on E-cadherin and produce conformational asym- metry so as to suppress the function of E-cadherin. Furthermore, the relationship between the expression of core fucosylated E-cadherin and clinicopathological background of lung cancer patients was explored in lung cancer tissue of patients. It turns out to demonstrate that core fucosylated E-cadherin could serve as a promising prognostic indicator for lung cancer patients.
