目的 探究驱动蛋白家族成员2A(kinesin family member 2A,KIF2A)对肝癌细胞5-FU耐药的作用及其作用机制。方法 采用浓度梯度递增联合大剂量间断冲击的方法诱导肝癌细胞BEL7402对5-FU耐药,以构建耐药株BEL7402/5-FU。采用慢病毒技术构建K...目的 探究驱动蛋白家族成员2A(kinesin family member 2A,KIF2A)对肝癌细胞5-FU耐药的作用及其作用机制。方法 采用浓度梯度递增联合大剂量间断冲击的方法诱导肝癌细胞BEL7402对5-FU耐药,以构建耐药株BEL7402/5-FU。采用慢病毒技术构建KIF2A沉默的BEL7402/5-FU细胞。用Notch1/Hes1信号通路激动剂丙戊酸(valproic acid,VPA)对KIF2A沉默的BEL7402/5-FU细胞进行干预。用CCK-8实验、蛋白印迹法、免疫荧光、流式细胞术检测细胞活性、细胞凋亡率、KIF2A、cleaved-caspase-3、Notch1和Hes1的蛋白表达。结果 BEL7402/5-FU细胞具有强5-FU耐药性,其IC_(50)为344.2μmol/L,是BEL7402细胞的92倍(IC_(50)=3.730μmol/L)。与BEL7402细胞比较,BEL7402/5-FU细胞中KIF2A蛋白表达明显增加(P<0.001);与si-NC组比较,si-KIF2A组BEL7402/5-FU细胞活性明显下降(P<0.001)、凋亡率和cleaved-caspase-3蛋白表达明显增加(P<0.001),另外Notch1和Hes1蛋白表达明显减少(P<0.001);与si-NC+5-FU组比较,si-KIF2A+5-FU组BEL7402/5-FU细胞活性显著下降(P<0.001)、凋亡率显著增加(P<0.001);与si-KIF2A+5-FU组比较,si-KIF2A+5-FU+VPA组BEL7402/5-FU细胞活性明显提高(P<0.001)、凋亡率显著降低(P<0.001)、Notch1和Hes1蛋白表达量显著增加(P<0.001)。结论 KIF2A的沉默通过抑制Notch1/Hes1信号通路活性减弱BEL7402/5-FU细胞对5-FU的化疗耐药性。展开更多
Apoptosis induced by endoplasmic reticulum(ER)stress plays a crucial role in mediating brain damage after ischemic stroke.Recently,Hes1(hairy and enhancer of split 1)has been implicated in the regulation of ER stress,...Apoptosis induced by endoplasmic reticulum(ER)stress plays a crucial role in mediating brain damage after ischemic stroke.Recently,Hes1(hairy and enhancer of split 1)has been implicated in the regulation of ER stress,but whether it plays a functional role after ischemic stroke and the underlying mechanism remain unclear.In this study,using a mouse model of ischemic stroke via transient middle cerebral artery occlusion(tMCAO),we found that Hes1 was induced following brain injury,and that siRNA-mediated knockdown of Hes1 increased the cerebral infarction and worsened the neurological outcome,suggesting that Hes1 knockdown exacerbates ischemic stroke.In addition,mechanistically,Hes1 knockdown promoted apoptosis and activated the PERK/eIF2a/ATF4/CHOP signaling pathway after tMCAO.These results suggest that Hes1 knockdown promotes ER stress-induced apoptosis.Furthermore,inhibition of PERK with the specific inhibitor GSK2606414 markedly attenuated the Hes1 knockdown-induced apoptosis and the increased cerebral infarction as well as the worsened neurological outcome following tMCAO,implying that the protection of Hes1 against ischemic stroke is associated with the amelioration of ER stress via modulating the PERK/eIF2a/ATF4/CHOP signaling pathway.Taken together,these results unveil the detrimental role of Hes1 knockdown after ischemic stroke and further relate it to the regulation of ER stress-induced apoptosis,thus highlighting the importance of targeting ER stress in the treatment of ischemic stroke.展开更多
In order to investigate the role of the Notch signaling pathway in skeletal muscle fibrosis after nerve injury, 60 Sprague-Dawley rats were selected and divided randomly into a control and two experimental groups. Gro...In order to investigate the role of the Notch signaling pathway in skeletal muscle fibrosis after nerve injury, 60 Sprague-Dawley rats were selected and divided randomly into a control and two experimental groups. Group A served as controls without any treatment. Rats in groups B were injected intraperitoneally with 0.2 mL PBS and those in group C were injected intraperitoneally with 0.2 mL PBS+100 ymol/L, 0.2 mL N-[N-(3,5-difluorophenacetyl)-l-alanyl]- S-phenylglycine t-butyl ester (DAPT, a gamma-secretase inhibitor that suppresses Notch signaling) respectively, on postoperative days 1, 3, 7, 10, and 14 in a model of denervation-induced skeletal muscle fibrosis by right sciatic nerve transection. Five rats from each group were euthanized on postoperative days 1, 7, 14, and 28 to collect the right gastrocnemii, and hematoxylin and eosin (HE) staining, immunohistochemistry test, real-time PCR, and Western blotting were performed to assess connective tissue hyperplasia and fibroblast density as well as expression of Notch 1, Jagged 1, and Notch downstream molecules Hes 1 and collagen I (COL I) on day 28. There was no significant difference in HE-stained fibroblast density between group B and C on postoperative day 1. However, fibroblast density was significantly higher in group B than in group C on postoperative days 7, 14, and 28. Notch 1, Jagged 1, Hes 1, and COL I proteins in the gastrocnemius were expressed at very low levels in group A but at high levels in group B. Expression levels of these proteins were significantly lower in group C than in group B (P<0.05), but they were higher in group C than in group A (P<0.05) on postoperative day 28. We are led to conclude that locking the Notch signaling pathway inhibits fibrosis progression of denervated skeletal muscle. Thus, it may be a new approach for treatment of fibrosis of denervated skeletal muscle.展开更多
文摘目的 探究驱动蛋白家族成员2A(kinesin family member 2A,KIF2A)对肝癌细胞5-FU耐药的作用及其作用机制。方法 采用浓度梯度递增联合大剂量间断冲击的方法诱导肝癌细胞BEL7402对5-FU耐药,以构建耐药株BEL7402/5-FU。采用慢病毒技术构建KIF2A沉默的BEL7402/5-FU细胞。用Notch1/Hes1信号通路激动剂丙戊酸(valproic acid,VPA)对KIF2A沉默的BEL7402/5-FU细胞进行干预。用CCK-8实验、蛋白印迹法、免疫荧光、流式细胞术检测细胞活性、细胞凋亡率、KIF2A、cleaved-caspase-3、Notch1和Hes1的蛋白表达。结果 BEL7402/5-FU细胞具有强5-FU耐药性,其IC_(50)为344.2μmol/L,是BEL7402细胞的92倍(IC_(50)=3.730μmol/L)。与BEL7402细胞比较,BEL7402/5-FU细胞中KIF2A蛋白表达明显增加(P<0.001);与si-NC组比较,si-KIF2A组BEL7402/5-FU细胞活性明显下降(P<0.001)、凋亡率和cleaved-caspase-3蛋白表达明显增加(P<0.001),另外Notch1和Hes1蛋白表达明显减少(P<0.001);与si-NC+5-FU组比较,si-KIF2A+5-FU组BEL7402/5-FU细胞活性显著下降(P<0.001)、凋亡率显著增加(P<0.001);与si-KIF2A+5-FU组比较,si-KIF2A+5-FU+VPA组BEL7402/5-FU细胞活性明显提高(P<0.001)、凋亡率显著降低(P<0.001)、Notch1和Hes1蛋白表达量显著增加(P<0.001)。结论 KIF2A的沉默通过抑制Notch1/Hes1信号通路活性减弱BEL7402/5-FU细胞对5-FU的化疗耐药性。
基金supported by grants from the Guangxi Zhuang Autonomous Region Health and Family Planning Commission Science and Technology Project(Z2016419)Guangxi Natural Science Foundation Project(No.:2018JJA140853)the Science and Technology Project of Hunan Province,China(2014FJ4233).
文摘Apoptosis induced by endoplasmic reticulum(ER)stress plays a crucial role in mediating brain damage after ischemic stroke.Recently,Hes1(hairy and enhancer of split 1)has been implicated in the regulation of ER stress,but whether it plays a functional role after ischemic stroke and the underlying mechanism remain unclear.In this study,using a mouse model of ischemic stroke via transient middle cerebral artery occlusion(tMCAO),we found that Hes1 was induced following brain injury,and that siRNA-mediated knockdown of Hes1 increased the cerebral infarction and worsened the neurological outcome,suggesting that Hes1 knockdown exacerbates ischemic stroke.In addition,mechanistically,Hes1 knockdown promoted apoptosis and activated the PERK/eIF2a/ATF4/CHOP signaling pathway after tMCAO.These results suggest that Hes1 knockdown promotes ER stress-induced apoptosis.Furthermore,inhibition of PERK with the specific inhibitor GSK2606414 markedly attenuated the Hes1 knockdown-induced apoptosis and the increased cerebral infarction as well as the worsened neurological outcome following tMCAO,implying that the protection of Hes1 against ischemic stroke is associated with the amelioration of ER stress via modulating the PERK/eIF2a/ATF4/CHOP signaling pathway.Taken together,these results unveil the detrimental role of Hes1 knockdown after ischemic stroke and further relate it to the regulation of ER stress-induced apoptosis,thus highlighting the importance of targeting ER stress in the treatment of ischemic stroke.
文摘In order to investigate the role of the Notch signaling pathway in skeletal muscle fibrosis after nerve injury, 60 Sprague-Dawley rats were selected and divided randomly into a control and two experimental groups. Group A served as controls without any treatment. Rats in groups B were injected intraperitoneally with 0.2 mL PBS and those in group C were injected intraperitoneally with 0.2 mL PBS+100 ymol/L, 0.2 mL N-[N-(3,5-difluorophenacetyl)-l-alanyl]- S-phenylglycine t-butyl ester (DAPT, a gamma-secretase inhibitor that suppresses Notch signaling) respectively, on postoperative days 1, 3, 7, 10, and 14 in a model of denervation-induced skeletal muscle fibrosis by right sciatic nerve transection. Five rats from each group were euthanized on postoperative days 1, 7, 14, and 28 to collect the right gastrocnemii, and hematoxylin and eosin (HE) staining, immunohistochemistry test, real-time PCR, and Western blotting were performed to assess connective tissue hyperplasia and fibroblast density as well as expression of Notch 1, Jagged 1, and Notch downstream molecules Hes 1 and collagen I (COL I) on day 28. There was no significant difference in HE-stained fibroblast density between group B and C on postoperative day 1. However, fibroblast density was significantly higher in group B than in group C on postoperative days 7, 14, and 28. Notch 1, Jagged 1, Hes 1, and COL I proteins in the gastrocnemius were expressed at very low levels in group A but at high levels in group B. Expression levels of these proteins were significantly lower in group C than in group B (P<0.05), but they were higher in group C than in group A (P<0.05) on postoperative day 28. We are led to conclude that locking the Notch signaling pathway inhibits fibrosis progression of denervated skeletal muscle. Thus, it may be a new approach for treatment of fibrosis of denervated skeletal muscle.
