SGK1 mediates hypotonic challenge-induced proliferation in basilar artery smooth muscle cells via promoting CREB signaling pathway
SGK1 mediates hypotonic challenge-induced proliferation in basilar artery smooth muscle cells via promoting CREB signaling pathway
复制标题
SGK1通过促进CREB信号通路介导低渗激发诱导的基底动脉平滑肌细胞增殖
DOI：
10.1016/j.ejphar.2021.173997
复制
发表时间：
2021-03-07
影响因子：
5
通讯作者：
Guan, Yong-Yuan
中科院分区：
文献类型：
--
作者：
Chen, Bao-Yi;Wang, Su-Rong;Guan, Yong-Yuan
低渗刺激使细胞体积增大，细胞增殖增加，其确切机制尚不清楚。糖皮质激素诱导的激酶-1（SGK 1）是一种丝氨酸/苏氨酸激酶，可受渗透压调节。我们已经发现，SGK 1被激活的低渗溶液诱导的细胞内Cl-浓度的降低。因此，我们进一步研究了SGK 1是否介导了低渗溶液诱导的基底平滑肌细胞（BASMCs）增殖及其内在机制。本研究采用BrdU掺入法、流式细胞术、Western blotting检测细胞活力、细胞周期转换、细胞周期调控因子及相关蛋白的表达。我们发现SGK 1的沉默在很大程度上减弱了低渗刺激诱导的细胞活力增加和细胞周期从G（0）/G（1）期向S期的转变，而SGK 1的过表达则表现出相反的效果。SGK 1对细胞增殖的影响与其上调细胞周期蛋白D1和E1，下调p27和p21有关，这是通过SGK 1与cAMP反应元件结合蛋白（CREB）的相互作用介导的。此外，我们过表达ClC-3 Cl-通道，以进一步验证SGK 1在低Cl环境诱导的增殖中的作用。结果显示，ClC-3的过表达进一步增强了低渗溶液诱导的细胞活力、细胞周期转换和CREB激活，而SGK 1的沉默或过表达则减轻或增强了这些。总之，本研究为SGK 1作为一种Cl-敏感性激酶，在低渗透压和BASMCs增殖之间起着重要作用提供了有力的证据，并为增殖相关性心血管疾病的治疗提供了新的思路。
Hypotonic stimulus enlarges cell volume and increased cell proliferation with the exact mechanisms unknown. Glucocorticoid-induced kinase-1 (SGK1) is a serine/threonine kinase that can be regulated by osmotic pressure. We have revealed that SGK1 was activated by hypotonic solution-induced lowering of intracellular Cl- concentration. Therefore, we further examined whether SGK1 mediated hypotonic solution-induced proliferation and the internal mechanisms in basilar smooth muscle cells (BASMCs). In the present study, BrdU incorporation assay, flow cytometry, western blotting were performed to evaluate cell viability, cell cycle transition, and the expression of cell cycle regulators and other related proteins. We found that silence of SGK1 largely blunted hypotonic challenge-induced increase in cell viability and cell cycle transition from G(0)/G(1) phase to S phase, whereas overexpression of SGK1 showed the opposite effects. The effect of SGK1 on proliferation was related to the upregulation of cyclin D1 and cyclin E1, and the downregulation of p27 and p21, which is mediated by the interaction between SGK1 and cAMP responsive element-binding protein (CREB). Moreover, we overexpressed ClC-3 Cl- channel to further verify the role of SGK1 in low Cl environment-induced proliferation. The results revealed that overexpression of ClC-3 further enhanced hypotonic solution-induced cell viability, cell cycle transition, and CREB activation, which were alleviated or potentiated by silencing or overexpression of SGK1. In summary, this study provides compelling evidences that SGK1, as a Cl- sensitive kinase, is a critical link between low osmotic pressure and proliferation in BASMCs, and shed a new light on the treatment of proliferationassociated cardiovascular diseases.