RESUMEN
BACKGROUND: Clinical evidence revealed abnormal prevalence of coronary artery (CA) disease in patients with pulmonary hypertension (PH). The mechanistic connection between PH and CA disease is unclear. Serotonin (5-hydroxytryptamine), reactive oxygen species, and Ca2+ signaling have been implicated in both PH and CA disease. Our recent study indicates that NOXs (NADPH [nicotinamide adenine dinucleotide phosphate] oxidases) and TRPM2 (transient receptor potential cation channel subfamily M member 2) are key components of their interplay. We hypothesize that activation of the NOX-TRPM2 pathway facilitates the remodeling of CA in PH. METHODS: Left and right CAs from chronic hypoxia and monocrotaline-induced PH rats were collected to study vascular reactivity, gene expression, metabolism, and mitochondrial function. Inhibitors or specific siRNA were used to examine the pathological functions of NOX1/4-TRPM2 in CA smooth muscle cells. RESULTS: Significant CA remodeling and 5-hydroxytryptamine hyperreactivity in the right CA were observed in PH rats. NOX1/4-mediated reactive oxygen species production coupled with TRPM2-mediated Ca2+ influx contributed to 5-hydroxytryptamine hyperresponsiveness. CA smooth muscle cells from chronic hypoxia-PH rats exhibited increased proliferation, migration, apoptosis, and metabolic reprogramming in an NOX1/4-TRPM2-dependent manner. Furthermore, the NOX1/4-TRPM2 pathway participated in mitochondrial dysfunction, involving mitochondrial DNA damage, reactive oxygen species production, elevated mitochondrial membrane potential, mitochondrial Ca2+ accumulation, and mitochondrial fission. In vivo knockdown of NOX1/4 alleviated PH and suppressed CA remodeling in chronic hypoxia rats. CONCLUSIONS: PH triggers an increase in 5-hydroxytryptamine reactivity in the right CA and provokes metabolic reprogramming and mitochondrial disruption in CA smooth muscle cells via NOX1/4-TRPM2 activation. This signaling pathway may play an important role in CA remodeling and CA disease in PH.
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Hipertensión Pulmonar , Canales Catiónicos TRPM , Humanos , Ratas , Animales , Hipertensión Pulmonar/metabolismo , Serotonina/farmacología , Serotonina/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Vasos Coronarios/patología , Canales Catiónicos TRPM/genética , Canales Catiónicos TRPM/metabolismo , Reprogramación Metabólica , Transducción de Señal , NADPH Oxidasas/metabolismo , Hipoxia/complicaciones , Hipoxia/metabolismo , Miocitos del Músculo Liso/metabolismo , NADPH Oxidasa 1/metabolismoRESUMEN
For decades, numerous experimental animal models have been developed to examine the pathophysiologic mechanisms and potential treatments for abdominal aortic aneurysms (AAAs) in diverse species with varying chemical or surgical approaches. This study aimed to create an AAA mouse model by the periarterial incubation with papain, which can mimic human AAA with advantages such as simplicity, convenience, and high efficiency. Eighty C57BL/6J male mice were randomly assigned to 1 of the 4 groups: papain (1.0 or 2.0 mg), porcine pancreatic elastase, and phosphate-buffered solution. The aortic segment was wrapped for 20 minutes, and the diameter was measured using ultrasound preoperatively and postoperative days 7 and 14. Then, the mice were killed for histomorphometric and immunohistochemical analyses. According to ultrasound measurements and histomorphometric analyses, on postoperative day 7, 65% of mice in the 1.0-mg papain group and 60% of mice in the 2.0-mg papain group developed AAA. In both papain groups, 100% of mice developed AAA, and 65% of mice in the porcine pancreatic elastase group developed AAA on postoperative day 14. Furthermore, hematoxylin/eosin, elastin van Gieson, and Masson staining of tissues from the papain group revealed thickened media and intimal hyperplasia, collagen sediments, and elastin destruction, indicating that AAA histochemical alteration was similar to that of humans. In addition, the immunohistochemical analysis was conducted to detect infiltrated inflammatory cells, such as macrophages and leukocytes, in the aortic wall and hyperplasic adventitia. The expression of matrix metalloproteinase 2 and 9 was significantly upregulated in papain and human AAA tissues. Periarterial incubation with 1.0 mg of papain for 20 minutes can successfully create an experimental AAA model in mice for 14 days, which can be used to explore the mechanism and treatment of human AAA.
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Aorta Abdominal , Aneurisma de la Aorta Abdominal , Masculino , Ratones , Humanos , Animales , Porcinos , Aorta Abdominal/metabolismo , Metaloproteinasa 2 de la Matriz/metabolismo , Elastina/efectos adversos , Elastina/metabolismo , Papaína/efectos adversos , Papaína/metabolismo , Ratones Endogámicos C57BL , Aneurisma de la Aorta Abdominal/inducido químicamente , Aneurisma de la Aorta Abdominal/metabolismo , Modelos Animales de Enfermedad , Elastasa Pancreática/efectos adversos , Elastasa Pancreática/metabolismoRESUMEN
BACKGROUND: Pulmonary arterial hypertension maintains rapid cell proliferation and vascular remodeling through metabolic reprogramming. Recent studies suggested that circRNAs play important role in pulmonary vascular remodeling and pulmonary arterial smooth muscle cells proliferation. However, the relationship between circRNA, cell proliferation, and metabolic reprogramming in pulmonary arterial hypertension has not been investigated. METHODS: RNA-seq and qRT-PCR reveal the differential expression profile of circRNA in pulmonary arteries of pulmonary arterial hypertension rat models. Transfection was used to examine the effects of circSMOC1 on pulmonary artery smooth muscle cells, and the roles of circSMOC1 in vivo were investigated by adenoassociated virus. Mass spectrometry, RNA pull-down, RNA immunoprecipitation, and dual-luciferase reporter assay were performed to investigate the signaling pathway of circSMOC1 regulating the metabolic reprogramming. RESULTS: CircSMOC1 was significantly downregulated in pulmonary arteries of pulmonary arterial hypertension rats. CircSMOC1 knockdown promoted proliferation and migration and enhanced aerobic glycolysis of pulmonary artery smooth muscle cells. CircSMOC1 overexpression in vivo alleviates pulmonary vascular remodeling, right ventricular pressure, and right heart hypertrophy. In the nucleus, circSMOC1 directly binds to PTBP1 (polypyrimidine tract-binding protein), competitively inhibits the specific splicing of PKM (pyruvate kinase M) premRNA, resulting in the upregulation of PKM2 (pyruvate kinase M2), the key enzyme of aerobic glycolysis, to enhance glycolysis. In the cytoplasm, circSMOC1 acted as a miR-329-3p sponge, and its reduction in pulmonary arterial hypertension suppressed PDHB (pyruvate dehydrogenase E1 subunit beta) expression, leading to the impairment of mitochondrial oxidative phosphorylation. CONCLUSIONS: circSMOC1 is crucially involved in the metabolic reprogramming of pulmonary artery smooth muscle cells through PTBP1 and miR-329-3p to regulate pulmonary vascular remodeling in pulmonary arterial hypertension.
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MicroARNs , Proteína de Unión al Tracto de Polipirimidina , Hipertensión Arterial Pulmonar , ARN Circular , Animales , Ratas , Proliferación Celular/genética , MicroARNs/genética , MicroARNs/metabolismo , Miocitos del Músculo Liso/metabolismo , Proteína de Unión al Tracto de Polipirimidina/genética , Proteína de Unión al Tracto de Polipirimidina/metabolismo , Hipertensión Arterial Pulmonar/genética , Arteria Pulmonar/metabolismo , Piruvato Quinasa/genética , Piruvato Quinasa/metabolismo , Piruvato Quinasa/farmacología , ARN Circular/genética , Remodelación Vascular/genéticaRESUMEN
The transient receptor potential canonical (TRPC) channels have been implicated in various types of malignancies including gastric cancer (GC). However, the detailed mechanisms of TRPC channels underlying cell proliferation and apoptosis of GC cells remain largely unknown. Here, we report that TRPC3 was highly expressed in clinical GC specimens and correlated with GC malignant progression and poor prognosis. Forced expression of TRPC3 in GC cells enhanced both receptor-operated Ca2+ entry (ROCE) and store-operated Ca2+ entry (SOCE) and promoted the nuclear factor of activated T cell 2 (NFATc2) nuclear translocation by AKT/GSK-3ß and CNB2 signaling. Pharmacological inhibition of TRPC3 or CRISPR/Cas9-mediated TRPC3 knockout effectively inhibited the growth of GC cells both in vitro and in vivo. These effects were reversible by the rescue of TRPC3 expression. Furthermore, we confirmed the role of TRPC3 and the ROCE-AKT/GSK3ß-CNB2/NFATc2 signaling cascade in regulating cell cycle checkpoint, apoptosis cascade, and intracellular ROS production in GC. Overall, our findings suggest an oncogenic role of TRPC3 in GC and may highlight a potential target of TRPC3 for therapeutic intervention of GC and its malignant progression.
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Carcinogénesis/metabolismo , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Factores de Transcripción NFATC/metabolismo , Transducción de Señal/fisiología , Neoplasias Gástricas/metabolismo , Canales Catiónicos TRPC/metabolismo , Animales , Apoptosis/fisiología , Carcinogénesis/patología , Línea Celular Tumoral , Proliferación Celular/fisiología , Humanos , Ratones , Oncogenes/fisiología , Transporte de Proteínas/fisiología , Especies Reactivas de Oxígeno/metabolismo , Neoplasias Gástricas/patologíaRESUMEN
Pulmonary hypertension (PH) is characterized by profound vascular remodeling and altered Ca2+ homeostasis in pulmonary arterial smooth muscle cells (PASMCs). Magnesium ion (Mg2+), a natural Ca2+ antagonist and a cofactor for numerous enzymes, is crucial for regulating diverse cellular functions, but its roles in PH remains unclear. Here, we examined the roles of Mg2+ and its transporters in PH development. Chronic hypoxia and monocrotaline induced significant PH in adult male rats. It was associated with a reduction of [Mg2+]i in PASMCs, a significant increase in gene expressions of Cnnm2, Hip14, Hip14l, Magt1, Mmgt1, Mrs2, Nipa1, Nipa2, Slc41a1, Slc41a2 and Trpm7; upregulation of SLC41A1, SLC41A2, CNNM2, and TRPM7 proteins; and downregulation of SLC41A3 mRNA and protein. Mg2+ supplement attenuated pulmonary arterial pressure, right heart hypertrophy, and medial wall thickening of pulmonary arteries, and reversed the changes in the expression of Mg2+ transporters. Incubation of PASMCs with a high concentration of Mg2+ markedly inhibited PASMC proliferation and migration, and increased apoptosis, whereas a low level of Mg2+ produced the opposite effects. siRNA targeting Slc41a1/2, Cnnm2, and Trpm7 attenuated PASMC proliferation and migration, but promoted apoptosis; and Slc41a3 overexpression also caused similar effects. Moreover, siRNA targeting Slc41a1 or high [Mg2+] incubation inhibited hypoxia-induced upregulation and nuclear translocation of NFATc3 in PASMCs. The results, for the first time, provide the supportive evidence that Mg2+ transporters participate in the development of PH by modulating PASMC proliferation, migration, and apoptosis; and Mg2+ supplementation attenuates PH through regulation of Mg2+ transporters involving the NFATc3 signaling pathway.
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Proteínas de Transporte de Catión/metabolismo , Hipertensión Pulmonar/metabolismo , Hipoxia/metabolismo , Magnesio/metabolismo , Músculo Liso Vascular/metabolismo , Arteria Pulmonar/metabolismo , Remodelación Vascular/efectos de los fármacos , Animales , Apoptosis/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Regulación hacia Abajo , Magnesio/farmacología , Masculino , Monocrotalina/farmacología , Músculo Liso Vascular/efectos de los fármacos , Miocitos del Músculo Liso/metabolismo , Arteria Pulmonar/efectos de los fármacos , Ratas , Regulación hacia ArribaRESUMEN
NEW FINDINGS: What is the central question of this study? The aim was to examine and compare the contributions of caveolin-1 to the contractile responses mediated by L-type voltage-dependent calcium channels, store-operated Ca2+ channels and receptor-operated Ca2+ channels in two different types of arteries from two-kidney, one-clip hypertensive rats. What is the main finding and its importance? We demonstrated that the density of caveolae and caveolin-1 expression were significantly upregulated in the aorta of two-kidney, one-clip hypertensive rats, but not in the third-order branches of mesenteric arteries. We highlight that caveolin-1 plays an important role in aortic constriction by enhancing receptor-operated Ca2+ entry in the hypertensive rat model. ABSTRACT: Calcium and its multiple regulatory mechanisms are crucial for the development of hypertension. Among these regulatory mechanisms, store-operated Ca2+ entry (SOCE) and receptor-operated Ca2+ entry (ROCE) mediate agonist-induced calcium influx, contributing to vascular contraction. The SOCE and ROCE are regulated by a variety of mechanisms involving caveolin-1 (Cav1), which has been found to be strongly associated with hypertension in gene polymorphism. In the present study, we investigated the role of Cav1 during the enhanced activity of calcium channels in hypertensive arteries. We demonstrated that the expression level of Cav1 was significantly increased in the aorta of two-kidney, one-clip (2K1C) hypertensive rats. The disruption of caveolae by methyl-ß-cyclodextrin did not cause a marked difference in agonist-induced vasoconstriction in the third-order branches of the mesenteric arteries but strongly suppressed the aortic contractile response to endothelin-1 in the 2K1C group, which was not found in the control group. The increase in Cav1 by introduction of Cav1 scaffolding domain enhancing peptide promoted the 1-oleoyl-2-acetyl-glycerol-induced ROCE in hypertensive aortic smooth muscle cells but did not enhance the cyclopiazonic acid-induced SOCE. In the resistance arteries, similar changes were not observed, and no statistical changes of Cav1 expression were evident in the third-order branches of the mesenteric arteries. Our results indicate that increased Cav1 expression might promote the altered [Ca2+ ]i -induced aortic vasoreactivity by enhancing ROCE and be involved in the pathogenesis of hypertension.
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Aorta/metabolismo , Calcio/metabolismo , Caveolina 1/metabolismo , Hipertensión/metabolismo , Animales , Masculino , Arterias Mesentéricas/metabolismo , Músculo Liso Vascular/metabolismo , Miocitos del Músculo Liso/metabolismo , Ratas , Ratas Sprague-DawleyRESUMEN
Pulmonary hypertension (PH) is characterized by enhanced vasoconstriction and vascular remodeling, which are attributable to the alteration of Ca2+ homeostasis in pulmonary arterial smooth muscle cells (PASMCs). It is well established that store-operated Ca2+ entry (SOCE) is augmented in PASMCs during PH and that it plays a crucial role in PH development. Our previous studies showed that the melastatin-related transient receptor potential 8 (TRPM8) is down-regulated in PASMCs of PH animal models, and activation of TRPM8 causes relaxation of pulmonary arteries (PAs). However, the mechanism of TRPM8-induced PA relaxation is unclear. Here we examined the interaction of TRPM8 and SOCE in PAs and PASMCs of normoxic and chronic hypoxic pulmonary hypertensive (CHPH) rats, a model of human group 3 PH. We found that TRPM8 was down-regulated and TRPM8-mediated cation entry was reduced in CHPH-PASMCs. Activation of TRPM8 with icilin caused concentration-dependent relaxation of cyclopiazonic acid (CPA) and endothelin-1 contracted endothelium-denuded PAs, and the effect was abolished by the SOCE antagonist Gd3+ Application of icilin to PASMCs suppressed CPA-induced Mn2+ quenching and Ca2+ entry, which was reversed by the TRPM8 antagonist N-(3-aminopropyl)-2-([(3-methylphenyl)methyl])-oxy-N-(2-thienylmethyl)benzamide hydrochloride salt (AMTB). Moreover, the inhibitory effects of icilin on SOCE in PA and PASMCs of CHPH rats were significantly augmented due to enhanced SOCE activity in PH. Our results, therefore, demonstrated a novel mechanism of TRPM8-mediated inhibition of SOCE in pulmonary vasculature. Because SOCE is important for vascular remodeling and enhanced vasoconstriction, down-regulation of TRPM8 in PASMCs of CHPH rats may minimize its inhibitory influence to allow unimpeded SOCE activity for PH development.
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Calcio/metabolismo , Hipertensión Pulmonar/patología , Hipertensión Pulmonar/fisiopatología , Arteria Pulmonar/fisiopatología , Canales Catiónicos TRPM/metabolismo , Vasodilatación/efectos de los fármacos , Animales , Transporte Biológico/efectos de los fármacos , Hipoxia de la Célula/efectos de los fármacos , Endotelina-1/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Hipertensión Pulmonar/metabolismo , Masculino , Miocitos del Músculo Liso/efectos de los fármacos , Miocitos del Músculo Liso/metabolismo , Arteria Pulmonar/efectos de los fármacos , Pirimidinonas/farmacología , Ratas , Ratas Sprague-Dawley , Canales Catiónicos TRPC/metabolismo , Vasoconstricción/efectos de los fármacosRESUMEN
This study was aimed to establish an optimized method to observe the synchronous changes of vascular tension and intracellular Ca2+ signal in the third-order branches of mesenteric arteries (sMA, diameter: 100-300 µm). The vascular tension and intracellular Ca2+ signal changes in response to potassium chloride (KCl), endothelin-1 (ET-1) and Gd3+ were detected using confocal wire myograph system and confocal laser scanning microscopy imaging technique, respectively. The experimental results were analyzed to explore the optimal experimental conditions. The results showed that KCl caused contraction in sMA significantly, and the intracellular Ca2+ level of vascular smooth muscle cells (VSMCs) was also increased under 20× and 40× objective lens. Compared with those under the 40× objective lens, the Ca2+ signal change was larger and the fluorescence value was more stable under the 20× objective lens, whereas the Ca2+ signal change was not obvious under the 10× objective lens. ET-1 (1-10 nmol/L) caused concentration dependent contraction in sMA significantly, and the intracellular Ca2+ signal of VSMCs was also enhanced in a concentration dependent manner. Additionally, Gd3+ significantly reduced the contraction of sMA and the intracellular Ca2+ signal of VSMCs caused by ET-1. The results suggest that the intracellular Ca2+ signal of VSMCs changes with vascular contraction or relaxation caused by the agonists or antagonists of Ca2+ channels. We successfully recorded both changes synchronously using confocal wire myograph system and confocal laser scanning microscopy imaging technique at the same time. Based on the analysis of the experimental results, we concluded that 20× objective lens provides the best experimental condition. Compared to combination of vascular tone detection method and real-time cellular fluorescence imaging technique, the present synchronous method is convenient and helpful to reduce experimental error.
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Señalización del Calcio/fisiología , Arterias Mesentéricas/fisiología , Animales , Endotelina-1/farmacología , Masculino , Microscopía Confocal , Músculo Liso Vascular/metabolismo , Miocitos del Músculo Liso/metabolismo , Cloruro de Potasio/farmacología , Ratas , Ratas Sprague-DawleyRESUMEN
OBJECTIVE: To evaluate the effects of environmental factors and microRNAs (miRNAs) (miR-126, miR-143, and miR-145) on the risk of coronary heart disease (CHD). METHODS: A frequency-matched case-control study (450 patients, 450 controls) was conducted from April 2014 to December 2016 in Fuzhou City, China. Environmental factors were investigated using a self-administered questionnaire, and the expression levels of miR-126, miR-143, and miR-145 were determined by quantitative real-time Polymerase Chain Reaction (PCR) in peripheral blood mononuclear cells. Unconditional logistic regression models were used for statistical evaluation. RESULTS: Alcohol consumption, high-salt diets, high-intensity work, and lack of physical activity were significantly associated with increased CHD risk, whereas light diet was significantly associated with decreased risk. MiR-126, miR-143, and miR-145 were highly expressed in the CHD group compared with the control group. After adjustment for other environmental factors, unconditional logistic regression results revealed that miR-126, miR-143, and depression were the independent risk factors of CHD, and light diet was the independent protective factor of CHD. CONCLUSIONS: Our data suggest that a family history of CHD, anxiety, and alcohol consumption was significantly associated with increased CHD risk, whereas light diet was significantly associated with decreased risk. Furthermore, miR-126 and miR-143 in combination with several risk factors, could play a joint role in the development of CHD. Therefore, it is necessary to manage patients with CHD in all directions and multiple level.
RESUMEN
BACKGROUND/AIMS: Alterations in intracellular Ca2+ concentration ([Ca2+]i) underlie the pathogenesis of various cardiovascular diseases. Caveolin-1 (Cav-1) is the primary functional protein associated with caveolae, which are invaginations in the plasma membrane, and is a regulator of [Ca2+]i signaling. Caveolae and Cav-1 increase the activity of store-operated Ca2+ channels (SOCC) in rat pulmonary arterial smooth muscle cells (PASMCs), and these enhancing effects were more pronounced in rats with pulmonary hypertension (PH). Classical transient receptor potential (TRPC) proteins are highly expressed in vascular smooth muscle cells, and these proteins form functional receptor-operated Ca2+ channels (ROCC) and SOCC in PASMCs. Previous studies suggested that functional and structural changes in aortas might occur during the pathological process of PH. Our data demonstrated that Cav-1 and TRPC were also abundant in the aorta smooth muscle cells (AoSMCs) of PH rats. However, previous PH research primarily focused on Ca2+ channels in pulmonary arteries, but not functional changes in Ca2+ channels in aortas. The contribution of Cav-1 of AoSMCs to alterations of Ca2+ signaling in aortic functions during the pathological process of PH has not been fully characterized. Therefore, this study investigated alterations in Cav-1 expression and the relationship of these changes to Ca2+ channels in AoSMCs of PH rats. METHODS: The present study examined physiological caveolae and Cav-1 expression and characterized the function of altered Cav-1 expression in rat aortas with PH. RESULTS: The appearance of caveolae with Cav-1 expression increased significantly in the aortas of rats with PH, but TRPC1 and TRPC6 expression was not altered. In vitro experiments demonstrated that caveolae contributed to phenylephrine, endothelin-1, and 1-oleoyl-2-acetyl-sn-glycerol (OAG)-induced aortic vasoreactivity, but KCl and cyclopiazonic acid had no effect, which suggests the vital ability of Cav-1 to regulate ROCC activity. The introduction of Cav-1 scaffolding domain peptide enhanced OAG-induced ROCC function in primary AoSMCs. CONCLUSION: Cav-1 is specifically associated with ROCC in aortas and plays a vital role in altering vasoreactivity, which affects cardiovascular diseases pathology. Caveolae and Cav-1 up-regulation may affect the function of ROCC in rat models of PH.
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Aorta/metabolismo , Calcio/metabolismo , Caveolina 1/metabolismo , Hipertensión Pulmonar/metabolismo , Animales , Aorta/fisiología , Aorta/ultraestructura , Western Blotting , Caveolas/metabolismo , Caveolina 1/genética , Células Cultivadas , Expresión Génica , Hipertensión Pulmonar/genética , Hipertensión Pulmonar/fisiopatología , Masculino , Microscopía Electrónica de Transmisión , Miocitos del Músculo Liso/metabolismo , Fenilefrina/farmacología , Ratas Sprague-Dawley , Receptores de Superficie Celular/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Canales Catiónicos TRPC/genética , Canales Catiónicos TRPC/metabolismo , Vasoconstricción/efectos de los fármacos , Vasoconstrictores/farmacologíaRESUMEN
Caveolin-1 (Cav-1) is a major component protein associated with caveolae in the plasma membrane and has been identified as a regulator of store-operated Ca(2+) entry (SOCE) and receptor-operated Ca(2+) entry (ROCE). However, the contributions of caveolae/Cav-1 of pulmonary arterial smooth muscle cells (PASMCs) to the altered Ca(2+) signaling pathways in pulmonary arteries (PAs) during pulmonary hypertension (PH) have not been fully characterized. The present study quantified caveolae number and Cav-1 expression, and determined the effects of caveolae disruption on ET-1, cyclopiazonic acid (CPA) and 1-Oleoyl-2-acetyl-glycerol (OAG)-induced contraction in PAs and Ca(2+) influx in PASMCs of chronic hypoxia (CH)- and monocrotaline (MCT)-induced PH rats. We found that the number of caveolae, and the Cav-1 mRNA and protein levels were increased significantly in PASMCs in both PH models. Disruption of caveolae by cholesterol depletion with methyl-ß-cyclodextrin (MßCD) significantly inhibited the contractile response to ET-1, CPA and OAG in PAs of control rats. ET-1, SOCE and ROCE-mediated contractile responses were enhanced, and their susceptibility to MßCD suppression was potentiated in the two PH models. MßCD-induced inhibition was reversed by cholesterol repletion. Introduction of Cav-1 scaffolding domain peptide to mimic Cav-1 upregulation caused significant increase in CPA- and OAG-induced Ca(2+) entry in PASMCs of control, CH and MCT-treated groups. Our results suggest that the increase in caveolae and Cav-1 expression in PH contributes to the enhanced agonist-induced contraction of PA via modulation of SOCE and ROCE; and targeting caveolae/Cav-1 in PASMCs may provide a novel therapeutic strategy for the treatment of PH.