Cavβ3 Regulates Ca(2+) Signaling and Insulin Expression in Pancreatic β-Cells in a Cell-Autonomous Manner.
Cavβ3 Regulates Ca(2+) Signaling and Insulin Expression in Pancreatic β-Cells in a Cell-Autonomous Manner.
复制标题
DOI：
10.2337/db21-0078
复制
发表时间：
2021-11
期刊：
影响因子：
7.7
通讯作者：
Belkacemi A
中科院分区：
文献类型：
--
作者：
Becker A;Wardas B;Salah H;Amini M;Fecher-Trost C;Sen Q;Martus D;Beck A;Philipp SE;Flockerzi V;Belkacemi A
电压门控Ca2+ (Cav)通道由成孔的Cavα1亚基和辅助的Cavα2-δ和Cavβ亚基组成。在成纤维细胞中，独立于Cav亚基的Cavβ3降低了对低浓度肌醇-1,4,5-三磷酸（IP3）的敏感性。同样，Cavβ3可以影响胰腺β-细胞的胞质钙浓度（[Ca2+]）。在本研究中，我们利用CRISPR/Cas9技术在胰岛素分泌大鼠β-(Ins-1)细胞中删除了cavβ 3-编码基因Cacnb3。这些细胞作为对照，研究Cavβ3在Cavβ3和IP3受体共免疫沉淀的野生型细胞中对Ca2+信号、葡萄糖诱导胰岛素分泌（GIIS）、Cav通道活性和基因表达的作用。转录和蛋白分析显示，在cavβ 3敲除细胞中，胰岛素转录因子Mafa、CaMKIV、蛋白转化酶subtilisin/kexin type-1和一氧化氮合酶-1的水平显著升高。在没有Cavβ3的情况下，Cav电流没有改变。相比之下，CREB活性，MAFA蛋白和GIIS的量，ip3依赖性Ca2+释放的程度和Ca2+振荡的频率增加。这些过程被Cavβ3蛋白以浓度依赖的方式减少。我们的研究表明，在分离的β细胞中，Cavβ3与IP3受体相互作用，独立于Cav通道功能控制IP3依赖性Ca2+信号，从而以细胞自主的方式调节胰岛素表达及其葡萄糖依赖性释放。
Voltage-gated Ca2+ (Cav) channels consist of a pore-forming Cavα1 subunit and auxiliary Cavα2-δ and Cavβ subunits. In fibroblasts, Cavβ3, independent of its role as a Cav subunit, reduces the sensitivity to low concentrations of inositol-1,4,5-trisphosphate (IP3). Similarly, Cavβ3 could affect cytosolic calcium concentration ([Ca2+]) in pancreatic β-cells. In this study, we deleted the Cavβ3-encoding gene Cacnb3 in insulin-secreting rat β-(Ins-1) cells using CRISPR/Cas9. These cells were used as controls to investigate the role of Cavβ3 on Ca2+ signaling, glucose-induced insulin secretion (GIIS), Cav channel activity, and gene expression in wild-type cells in which Cavβ3 and the IP3 receptor were coimmunoprecipitated. Transcript and protein profiling revealed significantly increased levels of insulin transcription factor Mafa, CaMKIV, proprotein convertase subtilisin/kexin type-1, and nitric oxide synthase-1 in Cavβ3-knockout cells. In the absence of Cavβ3, Cav currents were not altered. In contrast, CREB activity, the amount of MAFA protein and GIIS, the extent of IP3-dependent Ca2+ release and the frequency of Ca2+ oscillations were increased. These processes were decreased by the Cavβ3 protein in a concentration-dependent manner. Our study shows that Cavβ3 interacts with the IP3 receptor in isolated β-cells, controls IP3-dependent Ca2+-signaling independently of Cav channel functions, and thereby regulates insulin expression and its glucose-dependent release in a cell-autonomous manner.
登录
查看更多内容
影响因子：
8.8
作者：
Lee K;Kim J;Köhler M;Yu J;Shi Y;Yang SN;Ryu SH;Berggren PO
通讯作者：
Berggren PO
影响因子：
1.2
作者：
Belkacemi, Anouar;Laschke, Matthias W.;Flockerzi, Veit
通讯作者：
Flockerzi, Veit
影响因子：
4.8
作者：
Jeon, Daejong;Song, Inseon;Shin, Hee-Sup
通讯作者：
Shin, Hee-Sup
影响因子：
8.8
作者：
Belkacemi, Anouar;Hui, Xin;Flockerzi, Veit
通讯作者：
Flockerzi, Veit
影响因子：
10.9
作者：
Hang, Yan;Stein, Roland
通讯作者：
Stein, Roland