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Shima N, Yamamura A, Fujiwara M, Amano T, Matsumoto K, Sekine T, Okano H, Kondo R, Suzuki Y, Yamamura H. Up-regulated expression of two-pore domain K + channels, KCNK1 and KCNK2, is involved in the proliferation and migration of pulmonary arterial smooth muscle cells in pulmonary arterial hypertension. Front Cardiovasc Med 2024; 11:1343804. [PMID: 38410243 PMCID: PMC10894933 DOI: 10.3389/fcvm.2024.1343804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 01/29/2024] [Indexed: 02/28/2024] Open
Abstract
Background Pulmonary arterial hypertension (PAH) is a severe and rare disease in the cardiopulmonary system. Its pathogenesis involves vascular remodeling of the pulmonary artery, which results in progressive increases in pulmonary arterial pressure. Chronically increased pulmonary arterial pressure causes right ventricular hypertrophy and subsequent right heart failure. Pulmonary vascular remodeling is attributed to the excessive proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs), which are induced by enhanced Ca2+ signaling following the up-/down-regulation of ion channel expression. Objectives In the present study, the functional expression of two-pore domain potassium KCNK channels was investigated in PASMCs from idiopathic PAH (IPAH) patients and experimental pulmonary hypertensive (PH) animals. Results In IPAH-PASMCs, the expression of KCNK1/TWIK1 and KCNK2/TREK1 channels was up-regulated, whereas that of KCNK3/TASK1 and KCNK6/TWIK2 channels was down-regulated. The similar up-regulated expression of KCNK1 and KCNK2 channels was observed in the pulmonary arterial smooth muscles of monocrotaline-induced PH rats, Sugen 5416/hypoxia-induced PH rats, and hypoxia-induced PH mice. The facilitated proliferation of IPAH-PASMCs was suppressed by the KCNK channel blockers, quinine and tetrapentylammonium. The migration of IPAH-PASMCs was also suppressed by these channel blockers. Furthermore, increases in the proliferation and migration were inhibited by the siRNA knockdown of KCNK1 or KCNK2 channels. The siRNA knockdown also caused membrane depolarization and subsequent decrease in cytosolic [Ca2+]. The phosphorylated level of c-Jun N-terminal kinase (JNK) was elevated in IPAH-PASMCs compared to normal-PASMCs. The increased phosphorylation was significantly reduced by the siRNA knockdown of KCNK1 or KCNK2 channels. Conclusion Collectively, these findings indicate that the up-regulated expression of KCNK1 and KCNK2 channels facilitates the proliferation and migration of PASMCs via enhanced Ca2+ signaling and JNK signaling pathway, which is associated with vascular remodeling in PAH.
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Affiliation(s)
- Natsumi Shima
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Aya Yamamura
- Department of Physiology, Aichi Medical University, Nagakute, Japan
| | - Moe Fujiwara
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Taiki Amano
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Kazuyuki Matsumoto
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Taiga Sekine
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Haruka Okano
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Rubii Kondo
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Yoshiaki Suzuki
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Hisao Yamamura
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
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Inagaki S, Suzuki Y, Kawasaki K, Kondo R, Imaizumi Y, Yamamura H. Mitofusin 1 and 2 differentially regulate mitochondrial function underlying Ca 2+ signaling and proliferation in rat aortic smooth muscle cells. Biochem Biophys Res Commun 2023; 645:137-146. [PMID: 36689810 DOI: 10.1016/j.bbrc.2023.01.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 01/14/2023] [Indexed: 01/18/2023]
Abstract
Mitochondria play a substantial role in cytosolic Ca2+ buffering and energy metabolism. We recently demonstrated that mitofusin 2 (Mfn2) regulated Ca2+ signaling by tethering mitochondria and sarcoplasmic reticulum (SR), and thus, facilitated mitochondrial function and the proliferation of vascular smooth muscle cells (VSMCs). However, the physiological role of mitofusin 1 (Mfn1) on Ca2+ signaling and mitochondrial function remains unclear. Herein, the roles of Mfn1 and Mfn2 in mitochondrial function underlying Ca2+ signaling, ATP production, and cell proliferation were examined in rat aortic smooth muscle A10 cells. Following an arginine vasopressin-induced increase in cytosolic Ca2+ concentration ([Ca2+]cyt), Mfn2 siRNA (siMfn2) reduced cytosolic Ca2+ removal and mitochondrial Ca2+ uptake. However, Mfn1 siRNA (siMfn1) attenuated mitochondrial Ca2+ uptake, facilitated Ca2+ removal from mitochondria, and resulted in increased [Ca2+]cyt, which was mediated by the downregulation of mitochondrial Ca2+ uniporter (MCU) expression and the upregulation of mitochondrial Na+/Ca2+ exchanger (NCLX) expression. Furthermore, siMfn1 increased the mitochondrial membrane potential, ATP production by adenine nucleotide translocase (ANT), and cell proliferation, whereas siMfn2 exhibited the opposite responses. In conclusion, Mfn1 modulates the expressions of MCU, NCLX, and ANT, and Mfn2 tethers mitochondria to SR, which demonstrates their different mitochondrial functions for Ca2+ signaling, ATP production, and the proliferation of VSMCs.
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Affiliation(s)
- Sou Inagaki
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabedori Mizuhoku, Nagoya, 467-8603, Japan
| | - Yoshiaki Suzuki
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabedori Mizuhoku, Nagoya, 467-8603, Japan
| | - Keisuke Kawasaki
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabedori Mizuhoku, Nagoya, 467-8603, Japan
| | - Rubii Kondo
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabedori Mizuhoku, Nagoya, 467-8603, Japan
| | - Yuji Imaizumi
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabedori Mizuhoku, Nagoya, 467-8603, Japan
| | - Hisao Yamamura
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabedori Mizuhoku, Nagoya, 467-8603, Japan.
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Amano T, Yamamura A, Fujiwara M, Hirai S, Kondo R, Suzuki Y, Yamamura H. Upregulated ClC3 channels/transporters elicit swelling-activated Cl - currents and induce excessive cell proliferation in idiopathic pulmonary arterial hypertension. Biol Pharm Bull 2022; 45:1684-1691. [PMID: 35989293 DOI: 10.1248/bpb.b22-00513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pulmonary arterial hypertension (PAH) is characterized by vascular remodeling of the pulmonary artery, which is mainly attributed to the excessive proliferation of pulmonary arterial smooth muscle cells (PASMCs) comprising the medial layer of pulmonary arteries. The activity of ion channels associated with cytosolic Ca2+ signaling regulates the pathogenesis of PAH. Limited information is currently available on the role of Cl- channels in PASMCs. Therefore, the functional expression of ClC3 channels/transporters was herein investigated in the PASMCs of normal subjects and patients with idiopathic pulmonary arterial hypertension (IPAH). Expression analyses revealed the upregulated expression of ClC3 channels/transporters at the mRNA and protein levels in IPAH-PASMCs. Hypoosmotic perfusion (230 mOsm) evoked swelling-activated Cl- currents (ICl-swell) in normal-PASMCs, whereas 100 μM 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS) exerted the opposite effects. The siRNA knockdown of ClC3 did not affect ICl-swell. On the other hand, ICl-swell was larger in IPAH-PASMCs and inhibited by DIDS and the siRNA knockdown of ClC3. IPAH-PASMCs grew more than normal-PASMCs. The growth of IPAH-PASMCs was suppressed by niflumic acid and DIDS, but not by 9-anthracenecarboxylic acid or T16Ainh-A01. The siRNA knockdown of ClC3 also inhibited the proliferation of IPAH-PASMCs. Collectively, the present results indicate that upregulated ClC3 channels/transporters are involved in ICl-swell and the excessive proliferation of IPAH-PASMCs, thereby contributing to the pathogenesis of PAH. Therefore, ClC3 channels/transporters have potential as a target of therapeutic drugs for the treatment of PAH.
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Affiliation(s)
- Taiki Amano
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Aya Yamamura
- Department of Physiology, Aichi Medical University
| | - Moe Fujiwara
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Seiji Hirai
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Rubii Kondo
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Yoshiaki Suzuki
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Hisao Yamamura
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
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Kawata N, Kondo R, Suzuki Y, Yamamura H. Increased TMEM16A-mediated Ca 2+-activated Cl - currents in portal vein smooth muscle cells of caveolin 1-deficient mice. Biol Pharm Bull 2022; 45:1692-1698. [PMID: 35989294 DOI: 10.1248/bpb.b22-00514] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ca2+-activated Cl- (ClCa) channels regulate membrane excitability and myogenic tone in vascular smooth muscles. TMEM16A-coding proteins are mainly responsible for functional ClCa channels in vascular smooth muscles, including portal vein smooth muscles (PVSMs). Caveolae are cholesterol-rich and Ω-shaped invaginations on the plasma membrane that structurally contributes to effective and efficient signal transduction. Caveolin 1 (Cav1) accumulates in caveolae to form functional complexes among receptors, ion channels, and kinases. The present study examined the functional roles of Cav1 in the expression and activity of ClCa channels in the portal vein smooth muscle cells (PVSMCs) of wild-type (WT) and Cav1-knockout (KO) mice. Contractile experiments revealed that the amplitude of spontaneous PVSM contractions was larger in Cav1-KO mice than WT mice. Under whole-cell patch-clamp configurations, ClCa currents were markedly inhibited by 1 μM Ani9 (a selective TMEM16A ClCa channel blocker) in WT and Cav1-KO PVSMCs. However, Ani9-sensitive ClCa currents were significantly larger in Cav1-KO PVSMCs than in WT PVSMCs. Expression analyses showed that TMEM16A expression levels were higher in Cav1-KO PVSMs than in WT PVSMs. Therefore, the caveolar structure formed by Cav1 negatively regulates the expression and activity of TMEM16A-mediated ClCa channels in vascular smooth muscle cells.
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Affiliation(s)
- Naoki Kawata
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Rubii Kondo
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Yoshiaki Suzuki
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Hisao Yamamura
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
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Ando S, Mizutani H, Muramatsu M, Hagihara Y, Mishima H, Kondo R, Suzuki Y, Imaizumi Y, Yamamura H. Involvement of small-conductance Ca2+-activated K+ (SKCa2) channels in spontaneous Ca2+ oscillations in rat pinealocytes. Biochem Biophys Res Commun 2022; 615:157-162. [DOI: 10.1016/j.bbrc.2022.05.052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 05/14/2022] [Indexed: 11/02/2022]
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