Dataset Information

Transmembrane member 16A participates in hydrogen peroxide-induced apoptosis by facilitating mitochondria-dependent pathway in vascular smooth muscle cells.

ABSTRACT:

Background and purpose

Transmembrane member 16A (TMEM16A), an intrinsic constituent of the Ca²⁺ -activated Cl^- channel, is involved in vascular smooth muscle cell (VSMC) proliferation and hypertension-induced cerebrovascular remodelling. However, the functional significance of TMEM16A for apoptosis in basilar artery smooth muscle cells (BASMCs) remains elusive. Here, we investigated whether and how TMEM16A contributes to apoptosis in BASMCs.

Experimental approach

Cell viability assay, flow cytometry, Western blot, mitochondrial membrane potential assay, immunogold labelling and co-immunoprecipitation (co-IP) were performed.

Key results

Hydrogen peroxide (H₂ O₂ ) induced BASMC apoptosis through a mitochondria-dependent pathway, including by increasing the apoptosis rate, down-regulating the ratio of Bcl-2/Bax and potentiating the loss of the mitochondrial membrane potential and release of cytochrome c from the mitochondria to the cytoplasm. These effects were all reversed by the silencing of TMEM16A and were further potentiated by the overexpression of TMEM16A. Endogenous TMEM16A was detected in the mitochondrial fraction. Co-IP revealed an interaction between TMEM16A and cyclophilin D, a component of the mitochondrial permeability transition pore (mPTP). This interaction was up-regulated by H₂ O₂ but restricted by cyclosporin A, an inhibitor of cyclophilin D. TMEM16A increased mPTP opening, resulting in the activation of caspase-9 and caspase-3. The results obtained with cultured BASMCs from TMEM16A smooth muscle-specific knock-in mice were consistent with those from rat BASMCs.

Conclusions and implications

These results suggest that TMEM16A participates in H₂ O₂ -induced apoptosis via modulation of mitochondrial membrane permeability in VSMCs. This study establishes TMEM16A as a target for therapy of several remodelling-related diseases.

SUBMITTER: Zeng JW

PROVIDER: S-EPMC6109215 | biostudies-literature | 2018 Sep

REPOSITORIES: biostudies-literature

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Publications

Transmembrane member 16A participates in hydrogen peroxide-induced apoptosis by facilitating mitochondria-dependent pathway in vascular smooth muscle cells.

Zeng Jia-Wei JW Chen Bao-Yi BY Lv Xiao-Fei XF Sun Lu L Zeng Xue-Lin XL Zheng Hua-Qing HQ Du Yan-Hua YH Wang Guan-Lei GL Ma Ming-Ming MM Guan Yong-Yuan YY

British journal of pharmacology 20180809 18

<h4>Background and purpose</h4>Transmembrane member 16A (TMEM16A), an intrinsic constituent of the Ca<sup>2+</sup> -activated Cl<sup>-</sup> channel, is involved in vascular smooth muscle cell (VSMC) proliferation and hypertension-induced cerebrovascular remodelling. However, the functional significance of TMEM16A for apoptosis in basilar artery smooth muscle cells (BASMCs) remains elusive. Here, we investigated whether and how TMEM16A contributes to apoptosis in BASMCs.<h4>Experimental approach ...[more]

PMID: 29968377

Similar Datasets

Project description:Cell apoptosis is a biochemical and molecular pathway essential for maintaining cellular homeostasis. It is an integrated process involving in a series of signal transduction cascades. Moreover, the apoptotic pathways may be initiated inside various subcellular organelles. Increasing evidence indicates that hydrogen peroxide (H2O2) is closely related to cell apoptosis, particularly in the mitochondria. However, during the apoptotic process, the synergetic variation of H2O2 levels in different compartments is seldom explored, particularly in two important organelles: mitochondria and endoplasmic reticulum (ER). To solve this problem, we developed two new organelle-specific fluorescent probes termed MI-H2O2 and ER-H2O2 that can detect H2O2 in mitochondria and ER, respectively or simultaneously. Experimental results demonstrated that MI-H2O2 and ER-H2O2 display distinguishable excitation and emission spectra, as well as excellent organelle targeting capabilities. Therefore, we used MI-H2O2 and ER-H2O2 to successfully image exogenous or endogenous hydrogen peroxide in the mitochondria and ER. Interestingly, during diverse apoptotic stimuli, dual-color fluorescence imaging results revealed that the changes of H2O2 levels in mitochondria and ER are different. The H2O2 levels are enhanced in both the mitochondria and ER during the l-buthionine sulfoximine (BSO)-treated cell apoptosis process. During mitochondria-oriented apoptosis induced by carbonyl cyanide m-chlorophenylhydrazone (CCCP) or rotenone, H2O2 levels prominently and continuously increase in the mitochondria, whereas the ER H2O2 levels were found to rise subsequently after a delay. Moreover, during ER-oriented apoptosis induced by tunicamycin, ER is the major site for overproduction of H2O2, and delayed elevation of the H2O2 levels was found in the mitochondria. Altogether, this dual-probe and multicolor imaging approach may offer a proven methodology for studying molecular communication events on H2O2-related apoptosis and also other physiological and pathological processes within different subcellular organelles.

Dataset Information

Transmembrane member 16A participates in hydrogen peroxide-induced apoptosis by facilitating mitochondria-dependent pathway in vascular smooth muscle cells.

Background and purpose

Experimental approach

Key results

Conclusions and implications

Publications

Transmembrane member 16A participates in hydrogen peroxide-induced apoptosis by facilitating mitochondria-dependent pathway in vascular smooth muscle cells.

Similar Datasets

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