The decapentaplegic(Dpp),a member of the TGF-β superfamily,plays a pivotal role in the control of proliferation,global patterning and induction of specific cell fates during Drosophila development.Mother against Dpp(...The decapentaplegic(Dpp),a member of the TGF-β superfamily,plays a pivotal role in the control of proliferation,global patterning and induction of specific cell fates during Drosophila development.Mother against Dpp(Mad) is the founding member of the conserved Smad protein family which spe-cifically transduces the intracellular TGF-β signaling cascade.Here we report the 2.80 structure of the MH2 domain of Mad(Mad-MH2) that was readily superposed to the mammal Smad-MH2 structures.This unphosphorylated Mad-MH2 forms a symmetric homotrimer in crystals,consistent with the result of the size-exclusion chromatography that Mad-MH2 exhibited a propensity for concentration-dependent oligomerization prior to phosphorylation.Structural analysis revealed that the formation of homotrimeric Mad-MH2 is mainly mediated by contacts involving the extreme C-terminal SSVS motif,and is strengthened by phosphorylation of the last two Ser residues which was confirmed by the gel filtration analysis of the pseudophosphorylated Mad-MH2(DVD).Intriguingly,the homotrimer within an asymmetric unit only possesses two ordered C-terminal tails,reminiscent of the arrangement of the R-Smad/Smad4 complexes,indicating that the subunit with a flexible SSXS motif would be readily replaced by Co-Smad to form a functional heterotrimer.展开更多
MicroRNAs(miRNAs)have been demonstrated to control chicken skeletal muscle growth,however,the potential function of the miR-181-5p family in chicken myogenesis remains largely unknown.Here,our study identified the two...MicroRNAs(miRNAs)have been demonstrated to control chicken skeletal muscle growth,however,the potential function of the miR-181-5p family in chicken myogenesis remains largely unknown.Here,our study identified the two chicken(Gallus gallus;Gga)miR-181-5p family members widely expressed in various tissues,specifically miR-181a-5p and miR-181b-5p.Besides,the breast muscles of fast-growing broilers expressed higher levels of miR-181a-5p and miR-181b-5p than those of slow-growing layers.Functionally,miR-181a-5p and miR-181b-5p both promote the expression level of myogenic factors including myogenin(MyoG),myogenic differentiation 1(MyoD1),and myosin heavy chain(MyHC),meanwhile accelerating the myotube formation of skeletal muscle satellite cells(SMSCs).Mechanistically,miR-181a-5p and miR-181b-5p directly bind to the 3′untranslated region(UTR)of the transforming growth factor beta receptor 1(TGFBR1)mRNA,further reducing the expression of TGFBR1.TGFBR1 is a key Transforming growth factor beta(TGF-β)signaling transduction receptor and had a negative function in muscle cell differentiation.Furthermore,knockdown of TGFBR1 facilitated the expression of chicken myogenic factors,boosted myotube formation,and decreased the SMAD family member 2/3(SMAD2/3)phosphorylation in chicken SMSCs.SMAD2/3 are downstream of TGF-βsignaling,and miR-181a-5p and miR-181b-5p could reduce the expression of TGFBR1 to further diminish the SMAD2/3 phosphorylation.Our findings revealed that the miR-181-5p family targets TGFBR1 to break the TGF-βsignaling transduction,which resulted in promoting chicken skeletal muscle development.展开更多
Aortic aneurysm （AA） is a common health problem with high mortality and no effective drugs. Transforming growth factor-β （TGF-β） superfamily members regulate various cellular processes, and TGF-β signaling has ...Aortic aneurysm （AA） is a common health problem with high mortality and no effective drugs. Transforming growth factor-β （TGF-β） superfamily members regulate various cellular processes, and TGF-β signaling has key roles in development, tissue homeo- stasis, and diseases. Interest in the role of TGF-β signaling in the pathogenesis of AAs has recently emerged, particularly since genetic studies demonstrated an association between gene mutations in components of TGF-β signaling and AAs. However, paradoxical discoveries have implicated dysregulated TGF-β signaling in aneurysm formation, complicating the precise functional role for TGF-β in aneurysm development and progression. Furthermore, interventions targeting towards TGF-β signaling using losartan, which may represent a suitable therapeutic option for AAs, were subject to skepticism especially because of conflicting experimental results obtained from TGF-β antibody treatment without knowledge of the underlying mechanism. We propose a TGF-β aneurysm paradox, which would provide a good opportunity for the development of genetic mouse models of AA. These models would be used to clarify the mechanisms underlying TGF-β signaling, which would translate into novel pharmacologic therapies based on the new molecular discoveries.展开更多
Background and Aims:Although activation of hepatic stellate cells(HSCs)plays a central role in the development of liver fibrosis,the mechanism underlying the activation of HSCs remains unclear.Keratin 17(KRT17),a memb...Background and Aims:Although activation of hepatic stellate cells(HSCs)plays a central role in the development of liver fibrosis,the mechanism underlying the activation of HSCs remains unclear.Keratin 17(KRT17),a member of the intermediate filament family,can regulate tumor cell proliferation and migration.The current study aimed to elucidate the role of KRT17 in the activation of HSCs and the mechanisms underlying liver fibrosis.Methods:The expression of KRT17 was determined using immunohistochemistry in tissue microarray.Western blotting and qRT-PCR assays were used to determine the KRT17 expression in fibrotic liver tissues obtained from human subjects and mice.LX-2 cells were treated with TGF-β1 recombinant protein and adipocyte differentiation mixture(MDI)mix to induce and reverse LX-2 cell activation,respectively,in order to explore the correlation between KRT17 and HSC activation.Additionally,cell proliferation and migration abilities of LX-2 cells transfected with KRT17-overexpressing plasmid or small interfering RNA were determined using CCK-8,flow cytometry,Transwell,and wound healing assays.Finally,rescue assay was used to explore the role of KRT17 in HSC activation and epithelial-mesenchymal transition(EMT).Results:The expression of KRT17 was higher in the hu-man and mouse fibrotic liver tissues than in healthy liver tissues,and it was positively correlated with HSC activa-tion.Upregulated KRT17 enhanced proliferation,migration,HSC activation and EMT in LX-2 cells,while knockdown of KRT17 reversed these effects.TGF-β1 recombinant protein accelerated KRT17-mediated EMT,HSC activation and proliferation,while TGF-β1 inhibitor counteracted the effect of KRT17 in vitro.Conclusions:KRT17 promoted HSC activation,proliferation and EMT in hepatic fibrosis probably via TGF-β1 signaling,and KRT17 might serve as a therapeutic target for the treatment of liver fibrosis.展开更多
Diapause,an important strategy used by insects to avoid adverse environments,is regulated by various cell signaling pathways.The results of our previous studies demonstrated that the transforming growth factor-β(TGF-...Diapause,an important strategy used by insects to avoid adverse environments,is regulated by various cell signaling pathways.The results of our previous studies demonstrated that the transforming growth factor-β(TGF-β)signaling pathway regulated pupal diapause in Helicoverpa armigera,which was accompanied by downregulation of proteins in TGF-βsignaling.However,to date the mechanism underlying this phenomenon remains unknown.Here,we cloned the E3 ubiquitin ligases gene Smurf.In vitro experiments showed that Smurf directly bound to TGF-βreceptor type I(TGFβRI)and Smad2.Overexpressing Smurf promoted ubiquitination of TGFβRI and Smad2,thereby downregulating their protein levels.Conversely,silencing of the Smurf gene suppressed ubiquitination of TGFβRI and Smad2 thereby increasing their protein levels.Results from in vivo co-immunoprecipitation assays revealed that the binding of Smurf to TGFβRI or Smad2 was stronger in diapause pupae than in nondiapause pupae.Injection of Smurf inhibitor A01 into diapause pupae markedly upregulated expression of TGFβRI and Smad2 proteins,leading to resumption of development in diapause pupae.Taken together,these findings suggested that ubiquitin ligase E3 Smurf participated in H.armigera diapause by regulating TGF-βsignaling,and thus could be playing a crucial role in insect diapause.展开更多
Smads are critical intracellular signal transducers for transforming growth factor-β(TGF-β) in mammalian cells. In this study, we have identified WD repeat-containing protein 74(WDR74) as a novel transcriptional coa...Smads are critical intracellular signal transducers for transforming growth factor-β(TGF-β) in mammalian cells. In this study, we have identified WD repeat-containing protein 74(WDR74) as a novel transcriptional coactivator for Smads in the canonical TGF-β signaling pathway. Through direct interactions with Smad proteins, WDR74 enhances TGF-β-mediated phosphorylation and nuclear accumulation of Smad2 and Smad3. Consequently, WDR74 enables stronger transcriptional responses and more robust TGF-β-induced physiological responses. Our findings have elucidated a critical role of WDR74 in regulating TGF-β signaling.展开更多
Objective Transdifferentiation exists between stromal cells or between stromal cells and cancer cells.Evodiamine and berberine are predominant pharmacological components of Zuojin pill,a prescription of Traditional Ch...Objective Transdifferentiation exists between stromal cells or between stromal cells and cancer cells.Evodiamine and berberine are predominant pharmacological components of Zuojin pill,a prescription of Traditional Chinese Medicine,playing crucial functions in remolding of tumor microenvironment.This study aimed to explore the effect of combination of evodiamine with berberine(cBerEvo)on the phenotypic transition of colon epithelial cells induced by tumor-associated fibroblasts,as well as the involved mechanisms.Methods Human normal colon epithelial cell line HCoEpiC cells were treated with the prepared conditioned medium of CCD-18 Co,a human colon myofibroblast line,to induce epithelial-mesenchymal transition.Phase contrast microscope was used to observe the morphological changes.Epithelial-mesenchymal transition markers including E-cadherin,vimentin and alpha-smooth muscle actin(α-SMA)were observed with immunofluorescence microscopy.Migration was assessed by wound healing assay.Western blotting was used to detect the expressions of E-cadherin,vimentin,α-SMA,Snail,ZEB1 and Smads.Results In contrast to the control,the tumor-associated fibroblasts-like CCD-18 Co cells induced downregulation of E-cadherin and up-regulation of vimentin,α-SMA,Snail and ZEB1(P<0.05),and promoted migration of HCoEpiCs(P<0.05),with over expression of Smads including Smad2,p-Smad2,Smad3,p-Smad3 and Smad4(P<0.05),which were abolished by a transforming growth factor-β(TGF-β)receptor inhibitor LY364947 and by cBerEvo in a concentration dependent manner.In addition,cBerEvo-inhibited ratios of p-Smad2/Smad2 and p-Smad3/Smad3 were also dose dependent.Conclusion The above results suggest that cBerEvo can regulate the differentiation of colon epithelial cells induced by CCD-18 Co through suppressing activity of TGF-β/Smads signaling pathway.展开更多
基金Supported by National Key Basic Research and Development Program of China (Grant Nos. 2006CB503900 and 2007CB914400)China National Funds for Distinguished Young Scientists (Grant No. 30425005)
文摘The decapentaplegic(Dpp),a member of the TGF-β superfamily,plays a pivotal role in the control of proliferation,global patterning and induction of specific cell fates during Drosophila development.Mother against Dpp(Mad) is the founding member of the conserved Smad protein family which spe-cifically transduces the intracellular TGF-β signaling cascade.Here we report the 2.80 structure of the MH2 domain of Mad(Mad-MH2) that was readily superposed to the mammal Smad-MH2 structures.This unphosphorylated Mad-MH2 forms a symmetric homotrimer in crystals,consistent with the result of the size-exclusion chromatography that Mad-MH2 exhibited a propensity for concentration-dependent oligomerization prior to phosphorylation.Structural analysis revealed that the formation of homotrimeric Mad-MH2 is mainly mediated by contacts involving the extreme C-terminal SSVS motif,and is strengthened by phosphorylation of the last two Ser residues which was confirmed by the gel filtration analysis of the pseudophosphorylated Mad-MH2(DVD).Intriguingly,the homotrimer within an asymmetric unit only possesses two ordered C-terminal tails,reminiscent of the arrangement of the R-Smad/Smad4 complexes,indicating that the subunit with a flexible SSXS motif would be readily replaced by Co-Smad to form a functional heterotrimer.
基金supported by the National Key Research and Development Program of China(2022YFF10002020)Sichuan Science and Technology Program,China(2021YFYZ0007 and 2021YFYZ0031).
文摘MicroRNAs(miRNAs)have been demonstrated to control chicken skeletal muscle growth,however,the potential function of the miR-181-5p family in chicken myogenesis remains largely unknown.Here,our study identified the two chicken(Gallus gallus;Gga)miR-181-5p family members widely expressed in various tissues,specifically miR-181a-5p and miR-181b-5p.Besides,the breast muscles of fast-growing broilers expressed higher levels of miR-181a-5p and miR-181b-5p than those of slow-growing layers.Functionally,miR-181a-5p and miR-181b-5p both promote the expression level of myogenic factors including myogenin(MyoG),myogenic differentiation 1(MyoD1),and myosin heavy chain(MyHC),meanwhile accelerating the myotube formation of skeletal muscle satellite cells(SMSCs).Mechanistically,miR-181a-5p and miR-181b-5p directly bind to the 3′untranslated region(UTR)of the transforming growth factor beta receptor 1(TGFBR1)mRNA,further reducing the expression of TGFBR1.TGFBR1 is a key Transforming growth factor beta(TGF-β)signaling transduction receptor and had a negative function in muscle cell differentiation.Furthermore,knockdown of TGFBR1 facilitated the expression of chicken myogenic factors,boosted myotube formation,and decreased the SMAD family member 2/3(SMAD2/3)phosphorylation in chicken SMSCs.SMAD2/3 are downstream of TGF-βsignaling,and miR-181a-5p and miR-181b-5p could reduce the expression of TGFBR1 to further diminish the SMAD2/3 phosphorylation.Our findings revealed that the miR-181-5p family targets TGFBR1 to break the TGF-βsignaling transduction,which resulted in promoting chicken skeletal muscle development.
基金supported by the grants from State Key Laboratory of Proteomics (No. SKLP-K200902)Chinese Key Program for Drug Invention (No. 2009ZX09501-027)Chinese National Key Program on Basic Research (Nos. 2005CB522506, 2006CB943501 and 2006BAI23B01-3)
文摘Aortic aneurysm （AA） is a common health problem with high mortality and no effective drugs. Transforming growth factor-β （TGF-β） superfamily members regulate various cellular processes, and TGF-β signaling has key roles in development, tissue homeo- stasis, and diseases. Interest in the role of TGF-β signaling in the pathogenesis of AAs has recently emerged, particularly since genetic studies demonstrated an association between gene mutations in components of TGF-β signaling and AAs. However, paradoxical discoveries have implicated dysregulated TGF-β signaling in aneurysm formation, complicating the precise functional role for TGF-β in aneurysm development and progression. Furthermore, interventions targeting towards TGF-β signaling using losartan, which may represent a suitable therapeutic option for AAs, were subject to skepticism especially because of conflicting experimental results obtained from TGF-β antibody treatment without knowledge of the underlying mechanism. We propose a TGF-β aneurysm paradox, which would provide a good opportunity for the development of genetic mouse models of AA. These models would be used to clarify the mechanisms underlying TGF-β signaling, which would translate into novel pharmacologic therapies based on the new molecular discoveries.
基金supported by the National Natural Science Foundation of China,General Project(No.82070624)Health Commission of Jiangsu Province,Key Project(No.ZDB2020006)+1 种基金Tianqing Liver Disease Research Foundation of China Hepatitis Prevention Foundation(No.TQGB20210029)Social Development Foundation of Nantong City(No.JC2019032).
文摘Background and Aims:Although activation of hepatic stellate cells(HSCs)plays a central role in the development of liver fibrosis,the mechanism underlying the activation of HSCs remains unclear.Keratin 17(KRT17),a member of the intermediate filament family,can regulate tumor cell proliferation and migration.The current study aimed to elucidate the role of KRT17 in the activation of HSCs and the mechanisms underlying liver fibrosis.Methods:The expression of KRT17 was determined using immunohistochemistry in tissue microarray.Western blotting and qRT-PCR assays were used to determine the KRT17 expression in fibrotic liver tissues obtained from human subjects and mice.LX-2 cells were treated with TGF-β1 recombinant protein and adipocyte differentiation mixture(MDI)mix to induce and reverse LX-2 cell activation,respectively,in order to explore the correlation between KRT17 and HSC activation.Additionally,cell proliferation and migration abilities of LX-2 cells transfected with KRT17-overexpressing plasmid or small interfering RNA were determined using CCK-8,flow cytometry,Transwell,and wound healing assays.Finally,rescue assay was used to explore the role of KRT17 in HSC activation and epithelial-mesenchymal transition(EMT).Results:The expression of KRT17 was higher in the hu-man and mouse fibrotic liver tissues than in healthy liver tissues,and it was positively correlated with HSC activa-tion.Upregulated KRT17 enhanced proliferation,migration,HSC activation and EMT in LX-2 cells,while knockdown of KRT17 reversed these effects.TGF-β1 recombinant protein accelerated KRT17-mediated EMT,HSC activation and proliferation,while TGF-β1 inhibitor counteracted the effect of KRT17 in vitro.Conclusions:KRT17 promoted HSC activation,proliferation and EMT in hepatic fibrosis probably via TGF-β1 signaling,and KRT17 might serve as a therapeutic target for the treatment of liver fibrosis.
基金supported by funds from the Technol-ogy Project of Guizhou Province(Qian Ke He Basic-ZK[2021]General 102)Youth Talents of Science and Tech-nology Projects from Guizhou Educational Department(Qian Jiao He KY Zi[2021]078)Talent Introduction Project of Guizhou University(Gui Da Ren Ji He[2019]04).
文摘Diapause,an important strategy used by insects to avoid adverse environments,is regulated by various cell signaling pathways.The results of our previous studies demonstrated that the transforming growth factor-β(TGF-β)signaling pathway regulated pupal diapause in Helicoverpa armigera,which was accompanied by downregulation of proteins in TGF-βsignaling.However,to date the mechanism underlying this phenomenon remains unknown.Here,we cloned the E3 ubiquitin ligases gene Smurf.In vitro experiments showed that Smurf directly bound to TGF-βreceptor type I(TGFβRI)and Smad2.Overexpressing Smurf promoted ubiquitination of TGFβRI and Smad2,thereby downregulating their protein levels.Conversely,silencing of the Smurf gene suppressed ubiquitination of TGFβRI and Smad2 thereby increasing their protein levels.Results from in vivo co-immunoprecipitation assays revealed that the binding of Smurf to TGFβRI or Smad2 was stronger in diapause pupae than in nondiapause pupae.Injection of Smurf inhibitor A01 into diapause pupae markedly upregulated expression of TGFβRI and Smad2 proteins,leading to resumption of development in diapause pupae.Taken together,these findings suggested that ubiquitin ligase E3 Smurf participated in H.armigera diapause by regulating TGF-βsignaling,and thus could be playing a crucial role in insect diapause.
基金partly supported by the grants from National Natural Science Foundation of China (Nos. 31730057, 91540205, and 31571447)National Basic Research Program of China (973 Program) (2015CB553803)the Fundamental Research Funds for the Central Universities
文摘Smads are critical intracellular signal transducers for transforming growth factor-β(TGF-β) in mammalian cells. In this study, we have identified WD repeat-containing protein 74(WDR74) as a novel transcriptional coactivator for Smads in the canonical TGF-β signaling pathway. Through direct interactions with Smad proteins, WDR74 enhances TGF-β-mediated phosphorylation and nuclear accumulation of Smad2 and Smad3. Consequently, WDR74 enables stronger transcriptional responses and more robust TGF-β-induced physiological responses. Our findings have elucidated a critical role of WDR74 in regulating TGF-β signaling.
基金supported by the National Natural Science Foundation of China(81903985,the running period is 2020.1-2022.12)Natural Science Foundation of Guangdong Province(2018A030310060,the running period is 2018.6-2021.5)Postdoctoral Research Foundation of China(2018M643353,the running period is 2018.9-2019.7)。
文摘Objective Transdifferentiation exists between stromal cells or between stromal cells and cancer cells.Evodiamine and berberine are predominant pharmacological components of Zuojin pill,a prescription of Traditional Chinese Medicine,playing crucial functions in remolding of tumor microenvironment.This study aimed to explore the effect of combination of evodiamine with berberine(cBerEvo)on the phenotypic transition of colon epithelial cells induced by tumor-associated fibroblasts,as well as the involved mechanisms.Methods Human normal colon epithelial cell line HCoEpiC cells were treated with the prepared conditioned medium of CCD-18 Co,a human colon myofibroblast line,to induce epithelial-mesenchymal transition.Phase contrast microscope was used to observe the morphological changes.Epithelial-mesenchymal transition markers including E-cadherin,vimentin and alpha-smooth muscle actin(α-SMA)were observed with immunofluorescence microscopy.Migration was assessed by wound healing assay.Western blotting was used to detect the expressions of E-cadherin,vimentin,α-SMA,Snail,ZEB1 and Smads.Results In contrast to the control,the tumor-associated fibroblasts-like CCD-18 Co cells induced downregulation of E-cadherin and up-regulation of vimentin,α-SMA,Snail and ZEB1(P<0.05),and promoted migration of HCoEpiCs(P<0.05),with over expression of Smads including Smad2,p-Smad2,Smad3,p-Smad3 and Smad4(P<0.05),which were abolished by a transforming growth factor-β(TGF-β)receptor inhibitor LY364947 and by cBerEvo in a concentration dependent manner.In addition,cBerEvo-inhibited ratios of p-Smad2/Smad2 and p-Smad3/Smad3 were also dose dependent.Conclusion The above results suggest that cBerEvo can regulate the differentiation of colon epithelial cells induced by CCD-18 Co through suppressing activity of TGF-β/Smads signaling pathway.
