TMEM16A ameliorates vascular remodeling by suppressing autophagy via inhibiting Bcl-2-p62 complex formation
TMEM16A ameliorates vascular remodeling by suppressing autophagy via inhibiting Bcl-2-p62 complex formation
复制标题
TMEM16A 通过抑制 Bcl-2-p62 复合物形成来抑制自噬，从而改善血管重塑。
DOI：
10.7150/thno.41028
复制
发表时间：
2020-01-01
期刊：
影响因子：
12.4
通讯作者：
Guan, Yong-Yuan
中科院分区：
文献类型：
--
作者：
Lv, Xiao-Fei;Zhang, Ya-Juan;Guan, Yong-Yuan
基本原理：跨膜元件16 A（TMEM 16 A）是钙激活的氯离子通道的组分，其调节血管平滑肌细胞（SMC）增殖和重塑。自噬是真核生物中高度保守的细胞分解代谢过程，在血管平滑肌细胞中发挥重要的生理功能。在目前的研究中，我们研究了TMEM 16 A和血管重塑过程中的自噬之间的关系。方法：我们产生了一个转基因小鼠，过表达TMEM 16 A特异性血管平滑肌细胞，以验证TMEM 16 A在血管重塑中的作用。采用的技术包括免疫荧光，电子显微镜，免疫共沉淀，和Western blotting.Results：自噬被激活血管紧张素II（AngII）诱导的高血压小鼠TMEM 16 A表达下降的动脉瘤。轻链3B（LC 3B）阳性斑点的数量与高血压期间主动脉的中横截面积和TMEM 16 A的表达相关。SMC特异性TMEM 16 A过表达显著抑制小鼠动脉瘤中AngII诱导的自噬。此外，在小鼠主动脉SMC（MASMC）中，AngII诱导的自噬体形成和自噬通量被TMEM 16 A上调阻断，并被TMEM 16 A敲低促进。TMEM 16 A对自噬的作用不依赖于mTOR途径，但与液泡蛋白分选34（VPS 34）酶的激酶活性降低相关。VPS 34的过表达减弱了TMEM 16 A过表达对MASMC增殖的影响，而TMEM 16 A下调的影响被VPS 34抑制剂消除。此外，免疫共沉淀测定揭示TMEM 16 A与p62相互作用。TMEM 16 A过表达抑制AngII诱导的p62-Bcl-2结合并增强Bcl-2-Beclin-1相互作用，导致Beclin-1/VPS 34复合物形成的抑制。结论：TMEM 16 A通过调节p62、Bcl-2、Beclin-1和VPS 34之间的相互作用，协同抑制血管自噬和重塑
Rationale: Transmembrane member 16A (TMEM16A) is a component of calcium-activated chloride channels that regulate vascular smooth muscle cell (SMC) proliferation and remodeling. Autophagy, a highly conserved cellular catabolic process in eukaryotes, exerts important physiological functions in vascular SMCs. In the current study, we investigated the relationship between TMEM16A and autophagy during vascular remodeling.Methods: We generated a transgenic mouse that overexpresses TMEM16A specifically in vascular SMCs to verify the role of TMEM16A in vascular remodeling. Techniques employed included immunofluorescence, electron microscopy, co-immunoprecipitation, and Western blotting.Results: Autophagy was activated in aortas from angiotensin II (AngII)-induced hypertensive mice with decreased TMEM16A expression. The numbers of light chain 3B (LC3B)-positive puncta in aortas correlated with the medial cross-sectional aorta areas and TMEM16A expression during hypertension. SMC-specific TMEM16A overexpression markedly inhibited AngII-induced autophagy in mouse aortas. Moreover, in mouse aortic SMCs (MASMCs), AngII-induced autophagosome formation and autophagic flux were blocked by TMEM16A upregulation and were promoted by TMEM16A knockdown. The effect of TMEM16A on autophagy was independent of the mTOR pathway, but was associated with reduced kinase activity of the vacuolar protein sorting 34 (VPS34) enzyme. Overexpression of VPS34 attenuated the effect of TMEM16A overexpression on MASMC proliferation, while the effect of TMEM16A downregulation was abrogated by a VPS34 inhibitor. Further, co-immunoprecipitation assays revealed that TMEM16A interacts with p62. TMEM16A overexpression inhibited AngII-induced p62-Bcl-2 binding and enhanced Bcl-2-Beclin-1 interactions, leading to suppression of Beclin-1/VPS34 complex formation. However, TMEM16A downregulation showed the opposite effects.Conclusion: TMEM16A regulates the four-way interaction between p62, Bcl-2, Beclin-1, and VPS34, and coordinately prevents vascular autophagy and remodeling