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TMEM16A ameliorates vascular remodeling by suppressing autophagy via inhibiting Bcl-2-p62 complex formation
- Source :
- Theranostics
- Publication Year :
- 2019
-
Abstract
- 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.
- Subjects :
- 0301 basic medicine
Genetically modified mouse
Male
autophagy
Vascular smooth muscle
vascular remodeling
Myocytes, Smooth Muscle
Medicine (miscellaneous)
Mice, Transgenic
030204 cardiovascular system & hematology
Muscle, Smooth, Vascular
03 medical and health sciences
Mice
0302 clinical medicine
Downregulation and upregulation
vacuolar protein sorting 34
Cellular catabolic process
Animals
Kinase activity
Pharmacology, Toxicology and Pharmaceutics (miscellaneous)
PI3K/AKT/mTOR pathway
Anoctamin-1
Cells, Cultured
smooth muscle cell
transmembrane member 16A
Chemistry
Autophagy
Angiotensin II
Class III Phosphatidylinositol 3-Kinases
Cell biology
Mice, Inbred C57BL
030104 developmental biology
Proto-Oncogene Proteins c-bcl-2
cardiovascular system
Transcription Factor TFIIH
Research Paper
Subjects
Details
- ISSN :
- 18387640
- Volume :
- 10
- Issue :
- 9
- Database :
- OpenAIRE
- Journal :
- Theranostics
- Accession number :
- edsair.doi.dedup.....be4adb1b2107ad9c25670dea0898faef