Background The present study aimed to investigate the detailed mode and specific sites for their binding as well as the functional relevance of this binding in the phenotypic proliferation of vascular smooth muscle ce...Background The present study aimed to investigate the detailed mode and specific sites for their binding as well as the functional relevance of this binding in the phenotypic proliferation of vascular smooth muscle cells(SMCs). Methods CREG knocked-down SMCs were employed to evaluate the biological activity of wtCREG and mCREG.Expressions of SMC differentiation markers SM myosin heavy chain(SM-MHC),SM-actin,heavy caldesmon and myocardin were determined by Western blotting using specific antibodies. Cellular growth of SMCs was assessed by bromide dewuridine (BrdU) incorporation and cell cycle analysis on fluorescence-activated cell sorting(FACS).A solid-phase binding assay was used to study the binding of CREG to extracellular domains of M6P/IGF2R.The cellular co-localization of the two recombinant CREGs with M6P/IGF2R was detected on SMC surface by immunoprecipitation and immunofluorescence analysis.Results The molecular weight of wtCREG was around 30 kD while that of the mCREG was～25 kD.Treatment of wtCREG with PNGase F reduced its molecular weight from～30 kD to～25 kD,whereas PNGase F treatment had no effect on the molecular weight of mCREG.Both wtCREG and mCREG proteins enhanced SMC differentiation,inhibited BrdU incorporation,and arrested cell cycle progression when added to the culture medium.In CREG knocked-down SMCs,the amount of CREG detected by immunoblotting in M6P/IGF2R immunoprecipitates was significantly reduced when compared to normal cells.Both recombinant CREGs co-immunoprecipitated with M6P/IGF2R, although slightly reduced amount of the mutant CREG was detected in M6P/IGF2R immunoprecipitates.Immunostaining revealed that His-tagged CREGs co-localized with IGF2R on the cell surface in a glycosylation-independent manner.In vitro binding assay showed that CREGs bound to M6P/ IGF2R extracellular domains 7-10 and 11-13 in a glycosylation -dependent and -independent manner,respectively.Further blocking experiments using soluble M6P/IGF2R fragments and M6P/IGF2R neutralizing antibody indicated that the biological activities of recombinant CREGs in SMC growth and the up-regulation of SMC differentiation markers were all abolished by treatment with the M6P/IGF2R neutralizing antibody. However,although the growth inhibitory effect of wtCREG was nearly abolished by D7-10 or D11-13,the effect of mCREG was only reversed by Dll-13,indicating that the binding to domains 11-13 is required for CREG to modulate the proliferation of SMCs.Conclusions These data suggest that solubleCREG proteins can exert their biological function via binding to the extracellular domains 7-10 and 11-13 of cell surface M6P/IGF2R in both a glycosylation-dependent and -independent manner.展开更多
Objective Leucine-rich repeats and immunoglobulin-like domains 1(LRIG1) is a newly identified human gene that inhibits the epidermal growth factor receptor(EGFR), which on combining with a ligand, can drive tumor grow...Objective Leucine-rich repeats and immunoglobulin-like domains 1(LRIG1) is a newly identified human gene that inhibits the epidermal growth factor receptor(EGFR), which on combining with a ligand, can drive tumor growth. This study investigated the interaction between human LRIG1 and EGFR and attempted to delineate the functions of as well as the mechanisms used by the extracellular(ECD) and cytoplasmic(CPD) domains of the human LRIG1 protein to downregulate human EGFR signaling activity.Methods Two constructed chimeric eukaryotic expression vectors, pIRES2-EGFP-3XFLAG-LRIG1-ET and p3FLAG-LRIG1-TC, encoding the extracellular and transmembrane regions(LRIG1-ET) and the transmembrane and cytoplasmic regions(LRIG1-TC), respectively, and the plasmid p3XFLAG-CMV-9-LRIG1 encoding full-length LRIG1(LRIG1-FL) were transfected into the human glioma cell line U251 or primary astrocytoma cells by using liposomes. The number and affinity of cell surface EGFR on transfected cells was determined by ^(125)I-EGF binding assay. Results The dissociation constant(KD) values for EGFR were higher, and the maximum increase was observed in the cells transfected into LRIG1-ET(1.36 folds). The number of maximal binding sites(Bmax) of the receptors was decreased in all transfected cells; the maximum decrease was noted in the cells transfected into LRIG1-FL(40.05%).Conclusion Both the ECD and CPD of LRIG1 are important to negate EGFR signaling. The ECD may interfere with the binding between EGFR and its ligand and facilitate the functions of CPD. The CPD may, when brought in proximity to EGFR, enhance receptor degradation. These two mechanisms can contribute to the downregulation of EGFR-mediated signaling by LRIG1.展开更多
目的探讨脑小血管病(CSVD)患者外周血G蛋白耦联雌激素受体30(GPER30)、神经元PAS结构域蛋白4(NPAS4)、FK506结合蛋白5(FKBP5)表达与认知功能障碍(CD)的相关性。方法前瞻性选取2022年1月至2023年12月郑州大学第二附属医院收治的227例CSV...目的探讨脑小血管病(CSVD)患者外周血G蛋白耦联雌激素受体30(GPER30)、神经元PAS结构域蛋白4(NPAS4)、FK506结合蛋白5(FKBP5)表达与认知功能障碍(CD)的相关性。方法前瞻性选取2022年1月至2023年12月郑州大学第二附属医院收治的227例CSVD患者,根据有无CD分为障碍组(n=66)与无障碍组(n=161)。比较两组患者的一般资料及外周血GPER30、NPAS4、FKBP5 m RNA表达水平,Logistic回归分析CSVD患者CD的影响因素,比较不同程度CD患者外周血GPER30、NPAS4、FKBP5 m RNA表达水平,采用Pearson法分析外周血GPER30、NPAS4、FKBP5 m RNA表达与蒙特利尔认知评估量表(Mo CA)评分的相关性。结果障碍组患者的年龄、病程分别为(72.49±5.68)岁、(2.69±0.78)年,明显高(长)于无障碍组的(67.51±7.04)岁、(2.31±0.62)年,差异均有统计学意义(P<0.05);障碍组患者的外周血GPER30 m RNA表达水平为1.02±0.17,明显低于无障碍组的1.66±0.31,NPAS4m RNA、FKBP5 m RNA表达水平分别为2.79±0.60、3.88±1.12,明显高于无障碍组的1.55±0.51、2.10±0.59,差异均有统计学意义(P<0.05);Logistic回归分析结果显示,年龄、病程、GPER30 m RNA、NPAS4 m RNA及FKBP5 m RNA均为CSVD患者CD的独立影响因素(P<0.05)。轻度组患者的外周血GPER30 m RNA表达水平为1.27±0.25,明显高于中重度组的0.70±0.12,NPAS4 m RNA、FKBP5 m RNA表达水平分别为2.31±0.58、3.19±1.07,明显低于中重度组的3.40±0.72、4.76±1.39,差异均有统计学意义(P<0.05);Pearson法分析结果显示,外周血GPER30 m RNA表达与CSVD患者Mo CA评分呈正相关(r=0.704,P<0.05),NPAS4 m RNA、FKBP5 m RNA与Mo CA评分呈负相关(r=-0.572、-0.542,P<0.05)。结论外周血GPER30、NPAS4、FKBP5是CSVD患者CD的独立相关因素,各指标表达水平与CD病情严重程度均具有一定相关性,可为临床判断CD、评估CD病情严重程度提供参考,以指导后续临床工作。展开更多
Middle East respiratory syndrome （MERS）, an emerging infectious disease caused by MERS coronavirus （MERS-CoV）, has garnered worldwide attention as a consequence of its continuous spread and pandemic potential, mak...Middle East respiratory syndrome （MERS）, an emerging infectious disease caused by MERS coronavirus （MERS-CoV）, has garnered worldwide attention as a consequence of its continuous spread and pandemic potential, making the development of effective vaccines a high priority. We previously demonstrated that residues 377-588 of MERS-CoV spike （S） protein receptor-binding domain （RBD） is a very promising MERS subunit vaccine candidate, capable of inducing potent neutralization antibody responses. In this study, we sought to identify an adjuvant that optimally enhanced the immunogenicity of S377-588 protein fused with Fc of human IgG （S377-588-Fc）. Specifically, we compared several commercially available adjuvants, including Freund＇s adjuvant, aluminum, Monophosphoryl lipid A, Montanide ISA51 and MF59 with regard to their capacity to enhance the immunogenicity of this subunit vaccine. In the absence of adjuvant, S377-588-Fc alone induced readily detectable neutralizing antibody and T-cell responses in immunized mice. However, incorporating an adjuvant improved its immunogenicity. Particularly, among the aforementioned adjuvants evaluated, MF59 is the most potent as judged by its superior ability to induce the highest titers of IgG, IgG1 and IgG2a subtypes, and neutralizing antibodies. The addition of MF59 significantly augmented the immunogenicity of S377-588-Fcto induce strong IgG and neutralizing antibody responses as well as protection against MERS-CoV infection in mice, suggesting that MF59 is an optimal adjuvant for MERS-CoV RBD-based subunit vaccines.展开更多
The reliable three dimensional (3-D) structure of the extracellular ligand-binding domain (V106-P322) of human interleukin-6 receptor (hlL-6R) has been constructed by means of computer-guided homology modeling techniq...The reliable three dimensional (3-D) structure of the extracellular ligand-binding domain (V106-P322) of human interleukin-6 receptor (hlL-6R) has been constructed by means of computer-guided homology modeling techniques using the crystal structure of the extracellular ligand-binding region (K52-L251) of human growth hormone receptor (hGHR) as templet. The space location of some key residues which influence the combination ability between the receptor and the ligand has been observed and the effects of point mutagenesis of the four conservative cysteine residues on the space conformation are analyzed. The results show that the space conformation of the side-chain carboxyl of E305 plays a key role in the ligand-binding ability. Furthermore, the space conformation of the side-chain carboxyl of E305 is very important for the electrostatic potential complementarity between hlL-6R and hlL-6 according to the docking method.展开更多
文摘Background The present study aimed to investigate the detailed mode and specific sites for their binding as well as the functional relevance of this binding in the phenotypic proliferation of vascular smooth muscle cells(SMCs). Methods CREG knocked-down SMCs were employed to evaluate the biological activity of wtCREG and mCREG.Expressions of SMC differentiation markers SM myosin heavy chain(SM-MHC),SM-actin,heavy caldesmon and myocardin were determined by Western blotting using specific antibodies. Cellular growth of SMCs was assessed by bromide dewuridine (BrdU) incorporation and cell cycle analysis on fluorescence-activated cell sorting(FACS).A solid-phase binding assay was used to study the binding of CREG to extracellular domains of M6P/IGF2R.The cellular co-localization of the two recombinant CREGs with M6P/IGF2R was detected on SMC surface by immunoprecipitation and immunofluorescence analysis.Results The molecular weight of wtCREG was around 30 kD while that of the mCREG was～25 kD.Treatment of wtCREG with PNGase F reduced its molecular weight from～30 kD to～25 kD,whereas PNGase F treatment had no effect on the molecular weight of mCREG.Both wtCREG and mCREG proteins enhanced SMC differentiation,inhibited BrdU incorporation,and arrested cell cycle progression when added to the culture medium.In CREG knocked-down SMCs,the amount of CREG detected by immunoblotting in M6P/IGF2R immunoprecipitates was significantly reduced when compared to normal cells.Both recombinant CREGs co-immunoprecipitated with M6P/IGF2R, although slightly reduced amount of the mutant CREG was detected in M6P/IGF2R immunoprecipitates.Immunostaining revealed that His-tagged CREGs co-localized with IGF2R on the cell surface in a glycosylation-independent manner.In vitro binding assay showed that CREGs bound to M6P/ IGF2R extracellular domains 7-10 and 11-13 in a glycosylation -dependent and -independent manner,respectively.Further blocking experiments using soluble M6P/IGF2R fragments and M6P/IGF2R neutralizing antibody indicated that the biological activities of recombinant CREGs in SMC growth and the up-regulation of SMC differentiation markers were all abolished by treatment with the M6P/IGF2R neutralizing antibody. However,although the growth inhibitory effect of wtCREG was nearly abolished by D7-10 or D11-13,the effect of mCREG was only reversed by Dll-13,indicating that the binding to domains 11-13 is required for CREG to modulate the proliferation of SMCs.Conclusions These data suggest that solubleCREG proteins can exert their biological function via binding to the extracellular domains 7-10 and 11-13 of cell surface M6P/IGF2R in both a glycosylation-dependent and -independent manner.
基金Supported by the grants of the National Natural Science Foundation of China(No.30973073 and 81172402)
文摘Objective Leucine-rich repeats and immunoglobulin-like domains 1(LRIG1) is a newly identified human gene that inhibits the epidermal growth factor receptor(EGFR), which on combining with a ligand, can drive tumor growth. This study investigated the interaction between human LRIG1 and EGFR and attempted to delineate the functions of as well as the mechanisms used by the extracellular(ECD) and cytoplasmic(CPD) domains of the human LRIG1 protein to downregulate human EGFR signaling activity.Methods Two constructed chimeric eukaryotic expression vectors, pIRES2-EGFP-3XFLAG-LRIG1-ET and p3FLAG-LRIG1-TC, encoding the extracellular and transmembrane regions(LRIG1-ET) and the transmembrane and cytoplasmic regions(LRIG1-TC), respectively, and the plasmid p3XFLAG-CMV-9-LRIG1 encoding full-length LRIG1(LRIG1-FL) were transfected into the human glioma cell line U251 or primary astrocytoma cells by using liposomes. The number and affinity of cell surface EGFR on transfected cells was determined by ^(125)I-EGF binding assay. Results The dissociation constant(KD) values for EGFR were higher, and the maximum increase was observed in the cells transfected into LRIG1-ET(1.36 folds). The number of maximal binding sites(Bmax) of the receptors was decreased in all transfected cells; the maximum decrease was noted in the cells transfected into LRIG1-FL(40.05%).Conclusion Both the ECD and CPD of LRIG1 are important to negate EGFR signaling. The ECD may interfere with the binding between EGFR and its ligand and facilitate the functions of CPD. The CPD may, when brought in proximity to EGFR, enhance receptor degradation. These two mechanisms can contribute to the downregulation of EGFR-mediated signaling by LRIG1.
文摘目的探讨脑小血管病(CSVD)患者外周血G蛋白耦联雌激素受体30(GPER30)、神经元PAS结构域蛋白4(NPAS4)、FK506结合蛋白5(FKBP5)表达与认知功能障碍(CD)的相关性。方法前瞻性选取2022年1月至2023年12月郑州大学第二附属医院收治的227例CSVD患者,根据有无CD分为障碍组(n=66)与无障碍组(n=161)。比较两组患者的一般资料及外周血GPER30、NPAS4、FKBP5 m RNA表达水平,Logistic回归分析CSVD患者CD的影响因素,比较不同程度CD患者外周血GPER30、NPAS4、FKBP5 m RNA表达水平,采用Pearson法分析外周血GPER30、NPAS4、FKBP5 m RNA表达与蒙特利尔认知评估量表(Mo CA)评分的相关性。结果障碍组患者的年龄、病程分别为(72.49±5.68)岁、(2.69±0.78)年,明显高(长)于无障碍组的(67.51±7.04)岁、(2.31±0.62)年,差异均有统计学意义(P<0.05);障碍组患者的外周血GPER30 m RNA表达水平为1.02±0.17,明显低于无障碍组的1.66±0.31,NPAS4m RNA、FKBP5 m RNA表达水平分别为2.79±0.60、3.88±1.12,明显高于无障碍组的1.55±0.51、2.10±0.59,差异均有统计学意义(P<0.05);Logistic回归分析结果显示,年龄、病程、GPER30 m RNA、NPAS4 m RNA及FKBP5 m RNA均为CSVD患者CD的独立影响因素(P<0.05)。轻度组患者的外周血GPER30 m RNA表达水平为1.27±0.25,明显高于中重度组的0.70±0.12,NPAS4 m RNA、FKBP5 m RNA表达水平分别为2.31±0.58、3.19±1.07,明显低于中重度组的3.40±0.72、4.76±1.39,差异均有统计学意义(P<0.05);Pearson法分析结果显示,外周血GPER30 m RNA表达与CSVD患者Mo CA评分呈正相关(r=0.704,P<0.05),NPAS4 m RNA、FKBP5 m RNA与Mo CA评分呈负相关(r=-0.572、-0.542,P<0.05)。结论外周血GPER30、NPAS4、FKBP5是CSVD患者CD的独立相关因素,各指标表达水平与CD病情严重程度均具有一定相关性,可为临床判断CD、评估CD病情严重程度提供参考,以指导后续临床工作。
文摘Middle East respiratory syndrome （MERS）, an emerging infectious disease caused by MERS coronavirus （MERS-CoV）, has garnered worldwide attention as a consequence of its continuous spread and pandemic potential, making the development of effective vaccines a high priority. We previously demonstrated that residues 377-588 of MERS-CoV spike （S） protein receptor-binding domain （RBD） is a very promising MERS subunit vaccine candidate, capable of inducing potent neutralization antibody responses. In this study, we sought to identify an adjuvant that optimally enhanced the immunogenicity of S377-588 protein fused with Fc of human IgG （S377-588-Fc）. Specifically, we compared several commercially available adjuvants, including Freund＇s adjuvant, aluminum, Monophosphoryl lipid A, Montanide ISA51 and MF59 with regard to their capacity to enhance the immunogenicity of this subunit vaccine. In the absence of adjuvant, S377-588-Fc alone induced readily detectable neutralizing antibody and T-cell responses in immunized mice. However, incorporating an adjuvant improved its immunogenicity. Particularly, among the aforementioned adjuvants evaluated, MF59 is the most potent as judged by its superior ability to induce the highest titers of IgG, IgG1 and IgG2a subtypes, and neutralizing antibodies. The addition of MF59 significantly augmented the immunogenicity of S377-588-Fcto induce strong IgG and neutralizing antibody responses as well as protection against MERS-CoV infection in mice, suggesting that MF59 is an optimal adjuvant for MERS-CoV RBD-based subunit vaccines.
文摘The reliable three dimensional (3-D) structure of the extracellular ligand-binding domain (V106-P322) of human interleukin-6 receptor (hlL-6R) has been constructed by means of computer-guided homology modeling techniques using the crystal structure of the extracellular ligand-binding region (K52-L251) of human growth hormone receptor (hGHR) as templet. The space location of some key residues which influence the combination ability between the receptor and the ligand has been observed and the effects of point mutagenesis of the four conservative cysteine residues on the space conformation are analyzed. The results show that the space conformation of the side-chain carboxyl of E305 plays a key role in the ligand-binding ability. Furthermore, the space conformation of the side-chain carboxyl of E305 is very important for the electrostatic potential complementarity between hlL-6R and hlL-6 according to the docking method.
