Icariin, a flavonoid glycoside, is extracted from Epimedium. This study aimed to investigate the vascular protective effects of icariin in type 1 diabetic rats by inhibiting high-mobility group box 1 (HMGB1)-related i...Icariin, a flavonoid glycoside, is extracted from Epimedium. This study aimed to investigate the vascular protective effects of icariin in type 1 diabetic rats by inhibiting high-mobility group box 1 (HMGB1)-related inflammation and exploring its potential mechanisms. The impact of icariin on vascular dysfunction was assessed in streptozotocin (STZ)-induced diabetic rats through vascular reactivity studies. Western blotting and immunofluorescence assays were performed to measure the expressions of target proteins. The release of HMGB1 and pro-inflammation cytokines were measured by enzyme-linked immunosorbent assay (ELISA). The results revealed that icariin administration enhanced acetylcholine-induced vasodilation in the aortas of diabetic rats. It also notably reduced the release of pro-inflammatory cytokines, including interleukin-8 (IL-8), IL-6, IL-1β, and tumor necrosis factor-alpha (TNF-α) in diabetic rats and high glucose (HG)-induced human umbilical vein endothelial cells (HUVECs). The results also unveiled that the pro-inflammatory cytokines in the culture medium of HUVECs could be increased by rHMGB1. The increased release of HMGB1 and upregulated expressions of HMGB1-related inflammatory factors, including advanced glycation end products (RAGE), Toll-like receptor 4 (TLR4), and phosphorylated p65 (p-p65) in diabetic rats and HG-induced HUVECs, were remarkably suppressed by icariin. Notably, HMGB1 translocation from the nucleus to the cytoplasm in HUVECs under HG was inhibited by icariin. Meanwhile, icariin could activate G protein-coupled estrogen receptor (GPER) and sirt1. To explore the role of GPER and Sirt1 in the inhibitory effect of icariin on HMGB1 release and HMGB-induced inflammation, GPER inhibitor and Sirt1 inhibitor were used in this study. These inhibitors diminished the effects of icariin on HMGB1 release and HMGB1-induced inflammation. Specifically, the GPER inhibitor also negated the activation of Sirt1 by icariin. These findings suggest that icariin activates GPER and increases the expression of Sirt1, which in turn reduces HMGB1 translocation and release, thereby improving vascular endothelial function in type 1 diabetic rats by inhibiting inflammation.展开更多
目的三阴性乳腺癌（triple-negative breast cancer,TNBC）指的是雌激素受体（ER）、孕激素受体（PR）和人表皮生长因子受体2（HER2）均为阴性的一类乳腺癌亚型.其靶向治疗已成为当前乳腺癌领域亟待解决的关键问题.本研究在于探讨G蛋白...目的三阴性乳腺癌（triple-negative breast cancer,TNBC）指的是雌激素受体（ER）、孕激素受体（PR）和人表皮生长因子受体2（HER2）均为阴性的一类乳腺癌亚型.其靶向治疗已成为当前乳腺癌领域亟待解决的关键问题.本研究在于探讨G蛋白耦联雌激素受体（G protein coupled estrogen receptor,GPER）作为TNBC潜在治疗靶标的可行性.利用Real-Time、Westernbot检测GPER在TNBC细胞中的表达,并利用流式细胞仪观察GPER活化后周期及凋亡发生情况,并结合划痕试验、Confocal、免疫荧光等手段探讨GPER活化后调控TNBC细胞侵袭转移的相关机制.结果表明GPER在TNBC细胞株中高表达.其特异性激动剂G-1可明显抑制MDA-MB-231和SkBr3细胞增殖,并造成细胞G2/M期阻滞,剂量依赖性下调cyclinB的表达.GPER活化后可上调p53的mRNA及蛋白表达,并促进其入核,降低其泛素化水平并增强其Ser15的磷酸化,从而抑制细胞增殖.进一步研究表明,G-1可持续性活化ERK1/2,并通过GPER/EGFR/ERK1/2下调cy-clinB的表达.且G-1可通过GPER/EGFR/ERK1/2上调p21并磷酸化p53,从而抑制细胞增殖.裸鼠移植瘤实验发现G-1可明显抑制肿瘤生长并提高其生存率,同时瘤内的cyclinB、Bcl-2表达明显下调.从而表明GPER活化可抑制TNBC的体内外生长.进一步研究表明,GPER的活化可以抑制TNBC细胞株MDA-MB-231及BT-549等体外侵袭转移,并阻止其发生上皮间质化（epithelial to mesenchymal transition,EMT）,机制研究发现GPER活化后可诱导PKA、PI3K/Akt、及PKC的活化,并通过磷酸化GSK-3β从而抑制NF-κB的磷酸化、核转位、及转录活性,从而下调纤连蛋白FN（Fibronectin）的表达.以上研究结果表明GPER活化可抑制TNBC细胞的体内外增殖及侵袭转移,从而提示其是TNBC潜在的重要治疗靶点.展开更多
基金supported by the National New Drug Innovation Program of China(No.2017ZX09301004)the National Natural Science Foundation of China(No.81873131)。
文摘Icariin, a flavonoid glycoside, is extracted from Epimedium. This study aimed to investigate the vascular protective effects of icariin in type 1 diabetic rats by inhibiting high-mobility group box 1 (HMGB1)-related inflammation and exploring its potential mechanisms. The impact of icariin on vascular dysfunction was assessed in streptozotocin (STZ)-induced diabetic rats through vascular reactivity studies. Western blotting and immunofluorescence assays were performed to measure the expressions of target proteins. The release of HMGB1 and pro-inflammation cytokines were measured by enzyme-linked immunosorbent assay (ELISA). The results revealed that icariin administration enhanced acetylcholine-induced vasodilation in the aortas of diabetic rats. It also notably reduced the release of pro-inflammatory cytokines, including interleukin-8 (IL-8), IL-6, IL-1β, and tumor necrosis factor-alpha (TNF-α) in diabetic rats and high glucose (HG)-induced human umbilical vein endothelial cells (HUVECs). The results also unveiled that the pro-inflammatory cytokines in the culture medium of HUVECs could be increased by rHMGB1. The increased release of HMGB1 and upregulated expressions of HMGB1-related inflammatory factors, including advanced glycation end products (RAGE), Toll-like receptor 4 (TLR4), and phosphorylated p65 (p-p65) in diabetic rats and HG-induced HUVECs, were remarkably suppressed by icariin. Notably, HMGB1 translocation from the nucleus to the cytoplasm in HUVECs under HG was inhibited by icariin. Meanwhile, icariin could activate G protein-coupled estrogen receptor (GPER) and sirt1. To explore the role of GPER and Sirt1 in the inhibitory effect of icariin on HMGB1 release and HMGB-induced inflammation, GPER inhibitor and Sirt1 inhibitor were used in this study. These inhibitors diminished the effects of icariin on HMGB1 release and HMGB1-induced inflammation. Specifically, the GPER inhibitor also negated the activation of Sirt1 by icariin. These findings suggest that icariin activates GPER and increases the expression of Sirt1, which in turn reduces HMGB1 translocation and release, thereby improving vascular endothelial function in type 1 diabetic rats by inhibiting inflammation.
文摘目的三阴性乳腺癌（triple-negative breast cancer,TNBC）指的是雌激素受体（ER）、孕激素受体（PR）和人表皮生长因子受体2（HER2）均为阴性的一类乳腺癌亚型.其靶向治疗已成为当前乳腺癌领域亟待解决的关键问题.本研究在于探讨G蛋白耦联雌激素受体（G protein coupled estrogen receptor,GPER）作为TNBC潜在治疗靶标的可行性.利用Real-Time、Westernbot检测GPER在TNBC细胞中的表达,并利用流式细胞仪观察GPER活化后周期及凋亡发生情况,并结合划痕试验、Confocal、免疫荧光等手段探讨GPER活化后调控TNBC细胞侵袭转移的相关机制.结果表明GPER在TNBC细胞株中高表达.其特异性激动剂G-1可明显抑制MDA-MB-231和SkBr3细胞增殖,并造成细胞G2/M期阻滞,剂量依赖性下调cyclinB的表达.GPER活化后可上调p53的mRNA及蛋白表达,并促进其入核,降低其泛素化水平并增强其Ser15的磷酸化,从而抑制细胞增殖.进一步研究表明,G-1可持续性活化ERK1/2,并通过GPER/EGFR/ERK1/2下调cy-clinB的表达.且G-1可通过GPER/EGFR/ERK1/2上调p21并磷酸化p53,从而抑制细胞增殖.裸鼠移植瘤实验发现G-1可明显抑制肿瘤生长并提高其生存率,同时瘤内的cyclinB、Bcl-2表达明显下调.从而表明GPER活化可抑制TNBC的体内外生长.进一步研究表明,GPER的活化可以抑制TNBC细胞株MDA-MB-231及BT-549等体外侵袭转移,并阻止其发生上皮间质化（epithelial to mesenchymal transition,EMT）,机制研究发现GPER活化后可诱导PKA、PI3K/Akt、及PKC的活化,并通过磷酸化GSK-3β从而抑制NF-κB的磷酸化、核转位、及转录活性,从而下调纤连蛋白FN（Fibronectin）的表达.以上研究结果表明GPER活化可抑制TNBC细胞的体内外增殖及侵袭转移,从而提示其是TNBC潜在的重要治疗靶点.
