活化T细胞核因子(nuclear factor of activated Tcell,NFAT)是具有多向调节功能的转录因子,如调节T细胞的活化、分化及自身耐受性等。近年来多项研究表明,NFAT可控制细胞因子和早期炎症反应过程中的基因表达,在支气管哮喘、阿尔茨海默...活化T细胞核因子(nuclear factor of activated Tcell,NFAT)是具有多向调节功能的转录因子,如调节T细胞的活化、分化及自身耐受性等。近年来多项研究表明,NFAT可控制细胞因子和早期炎症反应过程中的基因表达,在支气管哮喘、阿尔茨海默病、炎症性肠病、糖尿病等多种急、慢性疾病中起重要作用,对上述疾病的治疗和监测具有临床应用前景。文中综述近年来有关NFAT与临床疾病的研究进展。展开更多
Background：Mitofusin-2 （MFN2）,a well-known mitochondrial fusion protein,has been shown to participate in innate immunity,but its role in mediating adaptive immunity remains poorly characterized.In this study,we exp...Background：Mitofusin-2 （MFN2）,a well-known mitochondrial fusion protein,has been shown to participate in innate immunity,but its role in mediating adaptive immunity remains poorly characterized.In this study,we explored the potential role of MFN2 in mediating the immune function of T lymphocytes.Methods：We manipulated MFN2 gone expression in Jurkat cells via lentiviral transduction of MFN2 small interfering RNA （siRNA） or full-length MFN2.After transduction,the immune response and its underlying mechanism were determined in Jurkat cells.One-way analysis of variance and Student＇s t-test were performed to determine the statistical significance between the groups.Results：Overexpression of MFN2 enhanced the immune response of T lymphocytes by upregulating Ca2＋ （359.280 ± 10.130 vs.266.940 ± 10.170,P =0.000）,calcineurin （0.513 ± 0.014 vs.0.403 ± 0.020 nmol/L,P =0.024）,and nuclear factor of activated T cells （NFATs） activation （1.040 ± 0.086 vs.0.700 ± 0.115,P =0.005）,whereas depletion of MFN2 impaired the immune function ofT lymphocytes by downregulating Ca2＋ （141.140 ± 14.670 vs.267.060 ± 9.230,P =0.000）,calcineurin （0.054 ± 0.030 nmol/L vs.0.404 ± 0.063 nmol/L,P =0.000）,and NFAT activation （0.500 ± 0.025 vs.0.720 ± 0.061,P =0.012）.Furthermore,upregulated calcineurin partially reversed the negative effects ofMFN2 siRNA on T cell-mediated immunity evidenced by elevations in T cell proliferation （1.120 ± 0.048 vs.0.580 ± 0.078,P =0.040）,interleukin-2 （IL-2） production （473.300 ± 24.100 vs.175.330 ± 12.900 pg/ml,P =0.000）,and the interferon-γ/IL-4 ratio （3.080 ± 0.156 vs.0.953 ± 0.093,P =0.000）.Meanwhile,calcineurin activity inhibitor depleted the positive effects of overexpressed MFN2 on T cells function.Conclusions：Our findings suggest that MFN2 may regulate T cell immune functions primarily through the Ca2＋-calcineurin-NFAT pathway.MFN2 may represent a potential therapeutic target for T cell immune dysfunction-related diseases.展开更多
目的:研究钙/钙调蛋白依赖性蛋白激酶Ⅱ(calcium/calmodulin-dependent protein kinaseⅡ,CaMKⅡ)和活化T细胞核因子(nuclear factor of activated T cells,NFAT)是否参与急性肾损伤(acute kidney injury,AKI)中肾小管上皮细胞(renal tu...目的:研究钙/钙调蛋白依赖性蛋白激酶Ⅱ(calcium/calmodulin-dependent protein kinaseⅡ,CaMKⅡ)和活化T细胞核因子(nuclear factor of activated T cells,NFAT)是否参与急性肾损伤(acute kidney injury,AKI)中肾小管上皮细胞(renal tubular epithelial cells,RTEC)凋亡并探讨其机制。方法:阿霉素(adriamycin,ADR)干预人近端肾小管上皮细胞HK-2建立RTEC凋亡模型,小干扰RNA(small interfering RNA,siRNA)沉默NFAT基因,流式细胞术测细胞凋亡率。ADR干预6~8周龄雌性BALB/c小鼠建立AKI模型,将小鼠分为3组:正常对照组、ADR组和ADR+CaMKⅡ抑制剂KN-93干预组,每组5只。酶联免疫吸附实验检测小鼠血清肌酐浓度。Western blot检测体内外Bax、Bcl-2、p-CaMKⅡ、CaMKⅡ及核NFAT的蛋白水平。结果:与正常对照组相比,ADR干预下,HK-2细胞凋亡率显著升高(P<0.01),小鼠血清肌酐和Bax蛋白表达显著升高,而Bcl-2蛋白表达显著下降(P<0.05)。ADR干预下,HK-2细胞和小鼠肾组织中CaMKⅡ活性(p-CaMKⅡ/t-CaMKⅡ)与核蛋白NFAT表达皆显著升高(P<0.01)。ADR干预的HK-2细胞和小鼠中抑制CaMKⅡ活性后,HK-2细胞凋亡率显著降低,小鼠血清肌酐和Bax蛋白表达显著回降,而Bcl-2蛋白表达显著回升,核蛋白NFAT表达显著回降(P<0.05)。此外,用钙调蛋白激活CaMKⅡ后HK-2细胞凋亡率显著升高(P<0.05);激活CaMKⅡ同时予siRNA沉默NFAT,HK-2细胞凋亡率显著降低(P<0.05)。结论:CaMKⅡ/NFAT通路激活可促进AKI小鼠肾小管上皮细胞凋亡。展开更多
Aim： To investigate the activation of the nuclear factor of activated T cells （NFAT） and its function in the corticosterone （CORT）-induced apoptosis of rat Leydig cells. Methods： NFAT in rat Leydig cells was det...Aim： To investigate the activation of the nuclear factor of activated T cells （NFAT） and its function in the corticosterone （CORT）-induced apoptosis of rat Leydig cells. Methods： NFAT in rat Leydig cells was detected by Western blotting and immunohistochemical staining. Cyclosporin A （CsA） was used to evaluate potential involvement of NFAT in the CORT-induced apoptosis of Leydig cells. Intracellular Ca^2＋ was monitored in CORT-treated Leydig cells using Fluo-3/AM. After the Leydig cells were incubated with either CORT or CORT plus CsA for 12 h, the levels of NFAT2 in the nuclei and in the cytoplasm were measured by semi-quantitative Western blotting. The role of NFAT2 in CORT- induced Leydig cell apoptosis was further evaluated by observing the effects of NFAT2 overexpression and the inhibition of NFAT2 activation by CsA on FasL expression and apoptosis. Results： We found that NFAT2 was the predominant isoform in Leydig cells. CsA blocked the CORT-induced apoptosis of the Leydig cells. The intracellular Ca^2＋ level in the Leydig cells was significantly increased after the CORT treatment. The CORT increased the level of NFAT2 in the nuclei and decreased its level in the cytoplasm. CsA blocked the CORT-induced nuclear translocation of NFAT2 in the Leydig cells. Both CORT-induced apoptosis and FasL expression in the rat Leydig cells were enhanced by the overexpression of NFAT2 and antagonized by CsA. Conclusion： NFAT2 was activated in CORT-induced Leydig cell apoptosis. The effects of NFAT2 overexpression and the inhibition of NFAT2 activation suggest that NFAT2 may potentially play a pro-apoptotic role in CORT-induced Leydig cell apoptosis through the up-regulation of FasL.展开更多
Emerging evidence suggests that plasma membrane calcium ATPases (PMCAs) play a key role as regulators of calcium-triggered signal transduction pathways via interaction with partner proteins. PMCAs regulate these pathw...Emerging evidence suggests that plasma membrane calcium ATPases (PMCAs) play a key role as regulators of calcium-triggered signal transduction pathways via interaction with partner proteins. PMCAs regulate these pathways by targeting specific proteins to cellular sub-domains where the levels of intracellular freecalcium are kept low by the calcium ejection properties of PMCAs. According to this model, PMCAs have been shown to interact functionally with the calcium-sensitive proteins neuronal nitric oxide synthase, calmodulindependent serine protein kinase, calcineurin and endothelial nitric oxidase synthase. Transgenic animals with altered expression of PMCAs are being used to evaluate the physiological significance of these interactions. To date, PMCA interactions with calcium-dependent partner proteins have been demonstrated to play a crucial role in the pathophysiology of the cardiovascular system via regulation of the nitric oxide and calcineurin/nuclear factor of activated T cells pathways. This new evidence suggests that PMCAs play a more sophisticated role than the mere ejection of calcium from the cells, by acting as modulators of signaling transduction pathways.展开更多
文摘活化T细胞核因子(nuclear factor of activated Tcell,NFAT)是具有多向调节功能的转录因子,如调节T细胞的活化、分化及自身耐受性等。近年来多项研究表明,NFAT可控制细胞因子和早期炎症反应过程中的基因表达,在支气管哮喘、阿尔茨海默病、炎症性肠病、糖尿病等多种急、慢性疾病中起重要作用,对上述疾病的治疗和监测具有临床应用前景。文中综述近年来有关NFAT与临床疾病的研究进展。
基金This study was supported by grants from the Natural Science Foundation of Zhejiang Province （No.LY13HI50006 and No. LY13H150004）, the National Natural Science Foundation （No. 81571937 and No. 81772112）, and the Key Construction Academic Subject （Medical Innovation） of Zhejiang Province （No. 11-CX26）.
文摘Background：Mitofusin-2 （MFN2）,a well-known mitochondrial fusion protein,has been shown to participate in innate immunity,but its role in mediating adaptive immunity remains poorly characterized.In this study,we explored the potential role of MFN2 in mediating the immune function of T lymphocytes.Methods：We manipulated MFN2 gone expression in Jurkat cells via lentiviral transduction of MFN2 small interfering RNA （siRNA） or full-length MFN2.After transduction,the immune response and its underlying mechanism were determined in Jurkat cells.One-way analysis of variance and Student＇s t-test were performed to determine the statistical significance between the groups.Results：Overexpression of MFN2 enhanced the immune response of T lymphocytes by upregulating Ca2＋ （359.280 ± 10.130 vs.266.940 ± 10.170,P =0.000）,calcineurin （0.513 ± 0.014 vs.0.403 ± 0.020 nmol/L,P =0.024）,and nuclear factor of activated T cells （NFATs） activation （1.040 ± 0.086 vs.0.700 ± 0.115,P =0.005）,whereas depletion of MFN2 impaired the immune function ofT lymphocytes by downregulating Ca2＋ （141.140 ± 14.670 vs.267.060 ± 9.230,P =0.000）,calcineurin （0.054 ± 0.030 nmol/L vs.0.404 ± 0.063 nmol/L,P =0.000）,and NFAT activation （0.500 ± 0.025 vs.0.720 ± 0.061,P =0.012）.Furthermore,upregulated calcineurin partially reversed the negative effects ofMFN2 siRNA on T cell-mediated immunity evidenced by elevations in T cell proliferation （1.120 ± 0.048 vs.0.580 ± 0.078,P =0.040）,interleukin-2 （IL-2） production （473.300 ± 24.100 vs.175.330 ± 12.900 pg/ml,P =0.000）,and the interferon-γ/IL-4 ratio （3.080 ± 0.156 vs.0.953 ± 0.093,P =0.000）.Meanwhile,calcineurin activity inhibitor depleted the positive effects of overexpressed MFN2 on T cells function.Conclusions：Our findings suggest that MFN2 may regulate T cell immune functions primarily through the Ca2＋-calcineurin-NFAT pathway.MFN2 may represent a potential therapeutic target for T cell immune dysfunction-related diseases.
基金Acknowledgment This work was supported by a grant from National Natural Science Foundation of China （30570681）.
文摘Aim： To investigate the activation of the nuclear factor of activated T cells （NFAT） and its function in the corticosterone （CORT）-induced apoptosis of rat Leydig cells. Methods： NFAT in rat Leydig cells was detected by Western blotting and immunohistochemical staining. Cyclosporin A （CsA） was used to evaluate potential involvement of NFAT in the CORT-induced apoptosis of Leydig cells. Intracellular Ca^2＋ was monitored in CORT-treated Leydig cells using Fluo-3/AM. After the Leydig cells were incubated with either CORT or CORT plus CsA for 12 h, the levels of NFAT2 in the nuclei and in the cytoplasm were measured by semi-quantitative Western blotting. The role of NFAT2 in CORT- induced Leydig cell apoptosis was further evaluated by observing the effects of NFAT2 overexpression and the inhibition of NFAT2 activation by CsA on FasL expression and apoptosis. Results： We found that NFAT2 was the predominant isoform in Leydig cells. CsA blocked the CORT-induced apoptosis of the Leydig cells. The intracellular Ca^2＋ level in the Leydig cells was significantly increased after the CORT treatment. The CORT increased the level of NFAT2 in the nuclei and decreased its level in the cytoplasm. CsA blocked the CORT-induced nuclear translocation of NFAT2 in the Leydig cells. Both CORT-induced apoptosis and FasL expression in the rat Leydig cells were enhanced by the overexpression of NFAT2 and antagonized by CsA. Conclusion： NFAT2 was activated in CORT-induced Leydig cell apoptosis. The effects of NFAT2 overexpression and the inhibition of NFAT2 activation suggest that NFAT2 may potentially play a pro-apoptotic role in CORT-induced Leydig cell apoptosis through the up-regulation of FasL.
基金Supported by The Breast Cancer Campaign and the Research Institute in Healthcare Sciences (Armesilla AL)The Wellcome Trust (Emerson M)
文摘Emerging evidence suggests that plasma membrane calcium ATPases (PMCAs) play a key role as regulators of calcium-triggered signal transduction pathways via interaction with partner proteins. PMCAs regulate these pathways by targeting specific proteins to cellular sub-domains where the levels of intracellular freecalcium are kept low by the calcium ejection properties of PMCAs. According to this model, PMCAs have been shown to interact functionally with the calcium-sensitive proteins neuronal nitric oxide synthase, calmodulindependent serine protein kinase, calcineurin and endothelial nitric oxidase synthase. Transgenic animals with altered expression of PMCAs are being used to evaluate the physiological significance of these interactions. To date, PMCA interactions with calcium-dependent partner proteins have been demonstrated to play a crucial role in the pathophysiology of the cardiovascular system via regulation of the nitric oxide and calcineurin/nuclear factor of activated T cells pathways. This new evidence suggests that PMCAs play a more sophisticated role than the mere ejection of calcium from the cells, by acting as modulators of signaling transduction pathways.
