Rho kinase and Na /H exchanger mediate endothelin-1-induced pulmonary arterial smooth muscle cell proliferation and migration. Huetsch John C,Walker Jasmine,Undem Clark,Lade Julie,Yun Xin,Baksh Syeda,Jiang Haiyang,Lai Ning,Shimoda Larissa A Physiological reports Excessive production of endothelin-1 (ET-1) has been observed in almost all forms of pulmonary hypertension. ET-1, a highly potent vasoconstrictor, can also potentiate pulmonary arterial smooth muscle cell (PASMC) growth and migration, both of which contribute to the vascular remodeling that occurs during the development of pulmonary hypertension. Increasing evidence indicates that alkalinization of intracellular pH (pH ), typically due to activation of Na /H exchange (NHE), is associated with enhanced PASMC proliferation and migration. We recently demonstrated that application of exogenous ET-1 increased NHE activity in murine PASMCs via a mechanism requiring Rho kinase (ROCK). However, whether ROCK and/or increased NHE activity mediate ET-1-induced migration and proliferation in PASMCs remains unknown. In this study, we used fluorescent microscopy in transiently cultured PASMCs from distal pulmonary arteries of the rat and the pH-sensitive dye, BCECF-AM, to measure changes in resting pH and NHE activity induced by exposure to exogenous ET-1 (10  mol/L) for 24 h. Cell migration and proliferation in response to ET-1 were also measured using Transwell assays and BrdU incorporation, respectively. We found that application of exogenous ET-1 had no effect on NHE1 expression, but increased pH , NHE activity, migration, and proliferation in rat PASMCs. Pharmacologic inhibition of NHE or ROCK prevented the ET-1-induced changes in cell function (proliferation and migration). Our results indicate that ET-1 modulates PASMC migration and proliferation via changes in pH homeostasis through a pathway involving ROCK. 10.14814/phy2.13698
    Orai1, 2, 3 and STIM1 promote store-operated calcium entry in pulmonary arterial smooth muscle cells. Wang Jian,Xu Chuyi,Zheng Qiuyu,Yang Kai,Lai Ning,Wang Tao,Tang Haiyang,Lu Wenju Cell death discovery Previous studies have demonstrated that besides the classic canonical transient receptor potential channel family, Orai family and stromal interaction molecule 1 (STIM1) might also be involved in the regulation of store-operated calcium channels (SOCCs). An increase in cytosolic free Ca concentration promoted by store-operated Ca entry (SOCE) in pulmonary arterial smooth muscle cells (PASMCs) is a major trigger for pulmonary vasoconstriction and proliferation and migration of PASMCs. In this study, our data revealed the following: (1) in both rat distal pulmonary arteries and PASMCs, chronic hypoxia exposure upregulated the expression of Orai1 and Orai2, without affecting Orai3 and STIM1; (2) either heterozygous knockout of HIF-1 in mice or knockdown of HIF-1 in PASMCs abolished the hypoxic upregulation of Orai2, but not Orai1, suggesting the hypoxic upregulation of Orai2 depends on HIF-1; and (3) using small interference RNA knockdown strategies, Orai1, 2, 3 and STIM1 were all shown to mediate SOCE in hypoxic PASMCs. Together, these results suggested that the components of SOCCs, including Orai1, 2, 3 and STIM1, may lead to novel therapeutic targets for the treatment of chronic hypoxia-induced pulmonary hypertension. 10.1038/cddiscovery.2017.74
    Aquaporin 1-mediated changes in pulmonary arterial smooth muscle cell migration and proliferation involve β-catenin. Yun Xin,Jiang Haiyang,Lai Ning,Wang Jian,Shimoda Larissa A American journal of physiology. Lung cellular and molecular physiology Exposure to hypoxia induces migration and proliferation of pulmonary arterial smooth muscle cells (PASMCs), leading to vascular remodeling and contributing to the development of hypoxic pulmonary hypertension. The mechanisms controlling PASMC growth and motility are incompletely understood, although aquaporin 1 (AQP1) plays an important role. In tumor, kidney, and stem cells, AQP1 has been shown to interact with β-catenin, a dual function protein that activates the transcription of crucial target genes (i.e., c-Myc and cyclin D1) related to cell migration and proliferation. Thus the goal of this study was to examine mechanisms by which AQP1 mediates PASMC migration and proliferation, with a focus on β-catenin. Using primary rat PASMCs from resistance level pulmonary arteries infected with adenoviral constructs containing green fluorescent protein (control; AdGFP), wild-type AQP1 (AdAQP1), or AQP1 with the COOH-terminal tail deleted (AdAQP1M), we demonstrated that increasing AQP1 expression upregulated β-catenin protein levels and the expression (mRNA and protein) of the known β-catenin targets c-Myc and cyclin D1. In contrast, infection with AdAQP1M had no effect on any of these variables. Using silencing approaches to reduce β-catenin levels prevented both hypoxia- and AQP1-induced migration and proliferation of PASMCs, as well as induction of c-Myc and cyclin D1 by AQP1. Thus our results indicate that elevated AQP1 levels upregulate β-catenin protein levels, via a mechanism requiring the AQP1 COOH-terminal tail, enhancing expression of β-catenin targets and promoting PASMC proliferation and migration. 10.1152/ajplung.00247.2016
    Genetic Variants in the Hedgehog Interacting Protein Gene Are Associated with the FEV1/FVC Ratio in Southern Han Chinese Subjects with Chronic Obstructive Pulmonary Disease. Zhang Zili,Wang Jian,Zheng Zeguang,Chen Xindong,Zeng Xiansheng,Zhang Yi,Li Defu,Shu Jiaze,Yang Kai,Lai Ning,Dong Lian,Lu Wenju BioMed research international BACKGROUND:Convincing evidences have demonstrated the associations between and polymorphisms and COPD in non-Asian populations. Here genetic variants in and were investigated in Southern Han Chinese COPD. METHODS:A case-control study was conducted, including 989 cases and 999 controls. The associations between SNPs genotypes and COPD were performed by a logistic regression model; for SNPs and COPD-related phenotypes such as lung function, COPD severity, pack-year of smoking, and smoking status, a linear regression model was employed. Effects of risk alleles, genotypes, and haplotypes of the 3 significant SNPs in the gene on FEV/FVC were also assessed in a linear regression model in COPD. RESULTS:The mean FEV/FVC% value was 46.8 in combined COPD population. None of the 8 selected SNPs apparently related to COPD susceptibility. However, three SNPs (rs12509311, rs13118928, and rs182859) in were associated significantly with the FEV/FVC% ( = 4.1 × 10) in COPD adjusting for gender, age, and smoking pack-years. Moreover, statistical significance between risk alleles and the FEV/FVC% ( = 2.3 × 10), risk genotypes, and the FEV/FVC% ( = 3.5 × 10) was also observed in COPD. CONCLUSIONS:Genetic variants in were related with FEV/FVC in COPD. Significant relationships between risk alleles and risk genotypes and FEV/FVC in COPD were also identified. 10.1155/2017/2756726
    Clinical characteristics and risk factors of pulmonary hypertension associated with chronic respiratory diseases: a retrospective study. Chen Yonghua,Liu Chunli,Lu Wenju,Li Mengxi,Hadadi Cyrus,Wang Elizabeth Wenqian,Yang Kai,Lai Ning,Huang Junyi,Li Shiyue,Zhong Nanshan,Zhang Nuofu,Wang Jian Journal of thoracic disease BACKGROUND:Chronic respiratory disease-associated pulmonary hypertension (PH) is an important subtype of PH, which lacks clinical epidemiological data in China. METHODS:Six hundred and ninety three patients hospitalized from 2010 to 2013 were classified by echocardiography according to pulmonary arterial systolic pressure (PASP): mild (36≤ PASP <50 mmHg); moderate (50≤ PASP <70 mmHg) and severe (PASP ≥70 mmHg). RESULTS:Dyspnea (93.51%) was the most common symptom. Hemoptysis observed in the severe group (6.42%) was significantly higher than the other two groups (P<0.05). COPD (78.35%), lung bullae (44.16%), tuberculosis (including obsolete pulmonary tuberculosis) (38.82%), and bronchiectasis (30.45%) were frequently present. Mild group occupied the highest proportion (84.7%) in COPD, while severe group occupied the highest proportion (19.3%) in pulmonary embolism (P<0.01). Age, partial pressure of oxygen (PaO2), hematocrit (HCT), partial pressure of carbon dioxide (PaCO2), increase of N-terminal pro brain natriuretic peptide (NT-proBNP) and right ventricular (RV) diameter (>20 mm) were associated with moderate-to-severe PH, while RV [odds ratio (OR) =3.53, 95% CI, 2.17-5.74], NT-proBNP (OR=2.44, 95% CI, 1.51-3.95), HCT (OR=1.03, 95% CI, 1.00-1.07) and PaCO2 (OR=1.01, 95% CI, 1.00-1.03) were independent risk factors. CONCLUSIONS:PH related to respiratory diseases is mostly mild to moderate, and the severity is associated with the category of respiratory disease. Increased HCT can be an independent risk factor for PH related to chronic respiratory diseases. 10.21037/jtd.2016.02.58
    Study Design and Interim Outcomes of Guangzhou Institute of Respiratory Disease COPD Biobank. Lu Wenju,Zheng Zeguang,Chen Xindong,Tan Hui,Wang Jian,Zhang Zili,Zheng Jinping,Chen Rongchang,Zhang Chenting,Xu Xiaoming,Chen Yuqin,Yang Quan,Xiong Mingmei,Guo Meihua,Zhou Qipeng,Tang Chun,Wang Yingfeng,Ye Jinmei,Li Defu,Shu Jiaze,Tan Shu,Xu Chuyi,Wang Yan,Lai Ning,Yang Kai,Lu Jiachun,Ran Pixin,Zhong Nanshan COPD BACKGROUND:GIRD COPD Biobank is a multicenter observational study blood-based database with local characteristics, in order to investigate the causes, risk factors, pathogenesis, prevalence patterns and trends of COPD and promote new pathogenic insights in China. METHODS:We enrolled 855 clinically COPD patients and 660 controls with normal lung function. Extensive data collection has been undertaken with questionnaires, clinical measurements, and collection and storage of blood specimens, following Standard Operating Procedures (SOP). All surveys had similar quality controls, supervisions, and training of the investigator team. RESULTS:Since September 2010, a total of 1515 subjects (1116 [73.7%] males; 855 [56.4%] diagnosed with COPD) were enrolled. Analyses of the design and interim results of the GIRD COPD Biobank Study identified patients with COPD were older, lower educational level, a longer history of pack-year smoking, less in kitchen fan usage, X-ray exposure, and history of disease (P < 0.01 for all); Most of the COPD subjects belonged to moderately severe or worse, stratified according to Global Lung Function Initiative (GLI); COPD patients had relatively more co-morbidities than controls; Environmental hazard exposures might be the main contributors to the reported respiratory symptoms; Cold air, haze, and influenza acted the top three factors to induce respiratory symptoms in both COPD cases and controls. CONCLUSION:The GIRD COPD Biobank Study has the potential to provide substantial novel insights into the genetics, biomarkers, environmental and lifestyle aspects of COPD. It is expected to provide new insights for pathogenesis and the long-term progression of COPD. 10.3109/15412555.2015.1069807
    Leydig cell tumor with lung metastasis diagnosed by lung biopsy. Lai Ning,Zeng Xin,Li Meichan,Shu Jiaze International journal of clinical and experimental pathology Leydig cell tumors are very rare and account for only 3% of testicular tumors and are generally benign. Only less than 0.2% of all testicular cancers were evidenced by metastatic spread. We report a 34-year-old man visited hospital because of coughing sputum mixed with blood. His chest CT showed bilateral patch clouding opacity. He was suspected with allergic alveolitis and treated with methylprednisolone. However, his symptoms and general condition deteriorated, and he visited our hospital. He had no abnormal findings on physical examination. A chest radiograph showed pneumonia in whole lung and CT showed multiple nodules and diffused ground glass opacities in both lung fields. Lung biopsy confirmed a diagnosis of Leydig cell tumor with lung metastasis. The diagnosis is based on the histopathology and immunohistochemistry.
    Ca(2+) and ion channels in hypoxia-mediated pulmonary hypertension. Lai Ning,Lu Wenju,Wang Jian International journal of clinical and experimental pathology Alveolar hypoxia, a consequence of many lung diseases, can have adverse effects on the pulmonary vasculature. The changes that occur in the pulmonary circulation with exposure to chronic hypoxia include reductions in the diameter of the pulmonary arteries due to structural remodeling of the vasculature. Although the structural and functional changes that occur in the development of pulmonary hypertension have been well investigated, less is known about the cellular and molecular mechanisms of this process. This review will discuss the role of several potassium and calcium channels in hypoxic pulmonary vasoconstriction, both in elevating calcium influx into pulmonary artery smooth muscle cells (PASMCs). In addition to other signal transduction pathways, Ca(2+) signaling in PASMCs plays an important role in the development and progression of pulmonary hypertension due to its central roles in vasoconstriction and vascular remodeling. This review will focus on the effect of chronic hypoxia on ion channels and the potential pathogenic role of Ca(2+) signaling and regulation in the progression of pulmonary hypertension.
    Intravascular large B-cell lymphoma confirmed by lung biopsy. Liu Chunli,Lai Ning,Zhou Ying,Li Shiyue,Chen Rongchang,Zhang Nuofu International journal of clinical and experimental pathology Intravascular lymphoma is a very rare form of large B-cell non-Hodgkin's lymphoma which is characterized by selective growth of lymphoma cells within the lumina of small blood vessels. We report a 64-year-old woman visited hospital because of persistent cough, intermittent high fever as high as 38.7 °C and occasional shortness of breath. Her chest CT showed left upper lobe pneumonia and tuberculosis skin test (PPD test) was positive. She was suspected with tuberculosis and treated with anti-tuberculosis drugs. However, her symptoms and general condition deteriorated, and she visited our hospital. She had no abnormal findings on physical examination, but had abnormal laboratory findings, including decreased hemoglobin, elevated LDH and C-reactive protein. Arterial blood gas analysis showed moderate hypoxaemia. A chest radiograph showed pneumonia in whole lung and CT showed diffused ground glass opacities in both lung fields. Lung biopsy confirmed a diagnosis of intravascular large B-cell lymphoma. Primary pulmonary manifestation is very rare. The diagnosis is based on the histopathology and immunohistochemistry.
    The aquaporin 1 C-terminal tail is required for migration and growth of pulmonary arterial myocytes. Lai Ning,Lade Julie,Leggett Kyle,Yun Xin,Baksh Syeda,Chau Eric,Crow Michael T,Sidhaye Venkataramana,Wang Jian,Shimoda Larissa A American journal of respiratory cell and molecular biology Pulmonary arterial smooth muscle cell (PASMC) proliferation and migration are important contributors to the vascular remodeling that occurs during development of pulmonary hypertension. We previously demonstrated that aquaporin (AQP)1, a member of the water channel family of proteins, was expressed in PASMCs and was necessary for hypoxia-induced migration; however, the mechanism by which AQP1 controls this response is unclear. The C-terminal tail of AQP1 contains putative calcium (EF-hand) and protein binding sites. Thus, we wanted to explore whether the C-terminal tail or the EF-hand motif of AQP1 was required for migration and proliferation. Rat PASMCs were isolated from distal pulmonary arteries, and proliferation and migration were measured using BrdU incorporation and transwell filters, respectively. To deplete AQP1, PASMCs were transfected with AQP1 small interference RNA (siRNA) or nontargeting siRNA. Knockdown of AQP1 reduced basal proliferation and hypoxia-induced migration and proliferation in PASMCs. In subsequent experiments, wild-type AQP1, AQP1 lacking the entire cytoplasmic C-terminal tail, or AQP1 with a mutation in the EF-hand motif were expressed in PASMCs using adenoviral constructs. For all AQP1 constructs, infection increased AQP1 protein levels, water permeability, and the change in cell volume induced by hypotonic challenge. Infection with wild-type and EF-hand mutated AQP1, but not C-terminal-deleted AQP1, increased PASMC migration and proliferation. Our results suggest that AQP1 controls proliferation and migration in PASMCs and that the mechanism requires the C-terminal tail of the protein but is independent of water transport or the EF-hand motif. 10.1165/rcmb.2013-0374OC
    Effects of chronic exposure to cigarette smoke on canonical transient receptor potential expression in rat pulmonary arterial smooth muscle. Wang Jian,Chen Yuqin,Lin Chunyi,Jia Jing,Tian Lichun,Yang Kai,Zhao Lei,Lai Ning,Jiang Qian,Sun Yueqian,Zhong Nanshan,Ran Pixin,Lu Wenju American journal of physiology. Cell physiology To clarify the possible mechanism of cigarette smoke (CS)-induced pulmonary hypertension and furthermore provide effective targets for prevention and treatment, the effects of chronic CS on rat pulmonary arterial smooth muscle in vivo and nicotine treatment on rat pulmonary arterial smooth muscle cells (PASMCs) in vitro were investigated. In this study, we demonstrated that chronic CS exposure led to rat weight loss, right ventricular hypertrophy, and pulmonary arterial remodeling. A fluorescence microscope was used to measure intracellular calcium concentration ([Ca(2+)]i) in rat distal PASMCs. Results showed that basal [Ca(2+)]i and store-operated calcium entry (SOCE) levels in PASMCs from 3- and 6-mo CS-exposed rats were markedly higher than those in cells from the unexposed control animals (the increases in 6-mo CS group were more significant than that in 3-mo group), accompanied with increased canonical transient receptor potential 1 (TRPC1) and TRPC6 expression at both mRNA and protein levels in isolated distal PA. Simultaneously, in vitro study showed that nicotine treatment (10 nM) significantly increased basal [Ca(2+)]i and SOCE and upregulated TRPC1 and TRPC6 expression in cultured rat distal PASMCs. TRPC siRNA knockdown strategies revealed that the elevations of basal [Ca(2+)]i and SOCE induced by nicotine in PASMCs were TRPC1 and TRPC6 dependent. These results suggested that chronic CS-induced changes in vascular tone and structure in PA and the development of pulmonary hypertension might be largely due to upregulation of TRPC1 and TRPC6 expression in PASMCs, in which nicotine played an important role. 10.1152/ajpcell.00048.2013
    Bone morphogenetic protein 2 decreases TRPC expression, store-operated Ca(2+) entry, and basal [Ca(2+)]i in rat distal pulmonary arterial smooth muscle cells. Zhang Yi,Lu Wenju,Yang Kai,Xu Lei,Lai Ning,Tian Lichun,Jiang Qian,Duan Xin,Chen Minsheng,Wang Jian American journal of physiology. Cell physiology Recent studies indicate that multiple bone morphogenetic protein (BMP) family ligands and receptors are involved in the development of pulmonary arterial hypertension, yet the underlying mechanisms are incompletely understood. Although BMP2 and BMP4 share high homology in amino acid sequence, they appear to exert divergent effects on chronic hypoxic pulmonary hypertension (CHPH). While BMP4 promotes vascular remodeling, BMP2 prevents CHPH. We previously demonstrated that BMP4 upregulates the expression of canonical transient receptor potential channel (TRPC) proteins and, thereby, enhances store-operated Ca(2+) entry (SOCE) and elevates intracellular Ca(2+) concentration ([Ca(2+)]i) in pulmonary arterial smooth muscle cells (PASMCs). In this study, we investigated the effects of BMP2 on these variables in rat distal PASMCs. We found that treatment with BMP2 (50 ng/ml, 60 h) inhibited TRPC1, TRPC4, and TRPC6 mRNA and protein expression. Moreover, BMP2 treatment led to reduced SOCE and decreased basal [Ca(2+)]i in PASMCs. These alterations were associated with decreased PASMC proliferation and migration. Conversely, knockdown of BMP2 with specific small interference RNA resulted in increased cellular levels of TRPC1, TRPC4, and TRPC6 mRNA and protein, enhanced SOCE, elevated basal [Ca(2+)]i, and increased proliferation and migration of PASMCs. Together, these results indicate that BMP2 participates in regulating Ca(2+) signaling in PASMCs by inhibiting TRPC1, TRPC4, and TRPC6 expression, thus leading to reduced SOCE and basal [Ca(2+)]i and inhibition of cell proliferation and migration. 10.1152/ajpcell.00036.2012
    Sildenafil inhibits hypoxia-induced transient receptor potential canonical protein expression in pulmonary arterial smooth muscle via cGMP-PKG-PPARγ axis. Wang Jian,Yang Kai,Xu Lei,Zhang Yi,Lai Ning,Jiang Hua,Zhang Yajie,Zhong Nanshan,Ran Pixin,Lu Wenju American journal of respiratory cell and molecular biology Transient receptor potential canonical (TRPC) proteins play important roles in chronically hypoxic pulmonary hypertension (CHPH). Previous results indicated that sildenafil inhibited TRPC1 and TRPC6 expression in rat distal pulmonary arteries (PAs). However, the underlying mechanisms remain unknown. We undertook this study to investigate the downstream signaling of sildenafil's regulation on TRPC1 and TRPC6 expression in pulmonary arterial smooth muscle cells (PASMCs). Hypoxia-exposed rats (10% O2 for 21 d) and rat distal PASMCs (4% O2 for 60 h) were taken as models to mimic CHPH. Real-time PCR, Western blotting, and Fura-2-based fluorescent microscopy were performed for mRNA, protein, and Ca(2+) measurements, respectively. The cellular cyclic guanosine monophosphate (cGMP) analogue 8-(4-chlorophenylthio)-guanosine 3',5'-cyclic monophosphate sodium salt (CPT-cGMP) (100 μM) inhibited TRPC1 and TRPC6 expression, store-operated Ca(2+) entry (SOCE), and the proliferation and migration of PASMCs exposed to prolonged hypoxia. The inhibition of CPT-cGMP on TRPC1 and TRPC6 expression in PASMCs was relieved by either the inhibition or knockdown of cGMP-dependent protein kinase (PKG) and peroxisome proliferator-activated receptor γ (PPARγ) expression. Under hypoxic conditions, CPT-cGMP increased PPARγ expression. This increase was abolished by the PKG antagonists Rp8 or KT5823. PPARγ agonist GW1929 significantly decreased TRPC1 and TRPC6 expression in PASMCs. Moreover, hypoxia exposure decreased, whereas sildenafil treatment increased, PKG and PPARγ expression in PASMCs ex vivo, and in rat distal PAs in vivo. The suppressive effects of sildenafil on TRPC1 and TRPC6 in rat distal PAs and on the hemodynamic parameters of CHPH were inhibited by treatment with the PPARγ antagonist T0070907. We conclude that sildenafil inhibits TRPC1 and TRPC6 expression in PASMCs via cGMP-PKG-PPARγ-dependent signaling during CHPH. 10.1165/rcmb.2012-0185OC
    Sodium tanshinone IIA sulfonate inhibits canonical transient receptor potential expression in pulmonary arterial smooth muscle from pulmonary hypertensive rats. Wang Jian,Jiang Qian,Wan Limei,Yang Kai,Zhang Yi,Chen Yuqin,Wang Elizabeth,Lai Ning,Zhao Lei,Jiang Hua,Sun Yueqian,Zhong Nanshan,Ran Pixin,Lu Wenju American journal of respiratory cell and molecular biology Danshen, the dried root of Salvia miltiorrhiza, is widely used in clinics in China for treating various diseases, including cardiovascular diseases. Sodium tanshinone IIA sulfonate (STS), a water-soluble derivative of tanshinone IIA isolated as the major active component from Danshen, was recently reported to be effective in attenuating the characteristic pulmonary vascular changes associated with chronically hypoxic pulmonary hypertension (CHPH); however, the underlying detailed mechanisms are poorly understood. In this study, we investigated the effects of STS on basal intracellular Ca(2+) concentration ([Ca(2+)](i)) and store-operated Ca(2+) entry (SOCE) in distal pulmonary arterial smooth muscle cells (PASMCs) exposed to prolonged hypoxia or isolated from CHPH rats. SOCE measured by Mn(2+) quenching of Fura-2 fluorescence in PASMCs from rats exposed to chronic hypoxia (10% O(2), 21 d) was increased by 59%, and basal [Ca(2+)](i) was increased by 119%; this effect was inhibited by intraperitoneal injection of STS. These inhibitory effects of STS on hypoxic increases of SOCE and basal [Ca(2+)](i) were associated with reduced expression of canonical transient receptor potential (TRPC)1 and TRPC6 in distal pulmonary arterial smooth muscle and decreases on right ventricular pressure, right ventricular hypertrophy, and peripheral pulmonary vessel thickening. In ex vivo cultured distal PASMCs from normoxic rats, STS (0-25 μM) dose-dependently inhibited hypoxia-induced cell proliferation and migration, paralleled with attenuation in increases of basal [Ca(2+)](i), SOCE, mRNA, and protein expression of TRPC1 and TRPC6. STS also relieved right ventricular systolic pressure, right ventricular hypertrophy, and TRPC1 and TRPC6 protein expression in distal pulmonary arteries in a monocrotaline-induced rat model of pulmonary arterial hypertension. These results indicate that STS prevents pulmonary arterial hypertension development likely by inhibiting TRPC1 and TRPC6 expression, resulting in normalized basal [Ca(2+)](i) and attenuated proliferation and migration of PASMCs. 10.1165/rcmb.2012-0071OC
    Hypoxia-induced migration in pulmonary arterial smooth muscle cells requires calcium-dependent upregulation of aquaporin 1. Leggett Kyle,Maylor Julie,Undem Clark,Lai Ning,Lu Wenju,Schweitzer Kelly,King Landon S,Myers Allen C,Sylvester J T,Sidhaye Venkataramana,Shimoda Larissa A American journal of physiology. Lung cellular and molecular physiology Pulmonary arterial smooth muscle cell (PASMC) migration is a key component of the vascular remodeling that occurs during the development of hypoxic pulmonary hypertension, although the mechanisms governing this phenomenon remain poorly understood. Aquaporin-1 (AQP1), an integral membrane water channel protein, has recently been shown to aid in migration of endothelial cells. Since AQP1 is expressed in certain types of vascular smooth muscle, we hypothesized that AQP1 would be expressed in PASMCs and would be required for migration in response to hypoxia. Using PCR and immunoblot techniques, we determined the expression of AQPs in pulmonary vascular smooth muscle and the effect of hypoxia on AQP levels, and we examined the role of AQP1 in hypoxia-induced migration in rat PASMCs using Transwell filter assays. Moreover, since the cytoplasmic tail of AQP1 contains a putative calcium binding site and an increase in intracellular calcium concentration ([Ca(2+)](i)) is a hallmark of hypoxic exposure in PASMCs, we also determined whether the responses were Ca(2+) dependent. Results were compared with those obtained in aortic smooth muscle cells (AoSMCs). We found that although AQP1 was abundant in both PASMCs and AoSMCs, hypoxia selectively increased AQP1 protein levels, [Ca(2+)](i), and migration in PASMCs. Blockade of Ca(2+) entry through voltage-dependent Ca(2+) or nonselective cation channels prevented the hypoxia-induced increase in PASMC [Ca(2+)](i), AQP1 levels, and migration. Silencing AQP1 via siRNA also prevented hypoxia-induced migration of PASMCs. Our results suggest that hypoxia induces a PASMC-specific increase in [Ca(2+)](i) that results in increased AQP1 protein levels and cell migration. 10.1152/ajplung.00130.2012
    Bone morphogenetic protein 4 enhances canonical transient receptor potential expression, store-operated Ca2+ entry, and basal [Ca2+]i in rat distal pulmonary arterial smooth muscle cells. Lu Wenju,Ran Pixin,Zhang Dandan,Lai Ning,Zhong Nanshan,Wang Jian American journal of physiology. Cell physiology Recent advances have identified an important role of bone morphogenetic protein 4 (BMP4) in pulmonary vascular remodeling, yet the underlying mechanisms remain largely unexplored. We have previously found that Ca(2+) influx through store-operated calcium channels (SOCC), which are mainly thought to be composed of canonical transient receptor potential (TRPC) proteins, likely contribute to the pathogenic development of chronic hypoxic pulmonary hypertension. In this study, we investigated the effect of BMP4 on expression of TRPC and store-operated Ca(2+) entry (SOCE) in pulmonary arterial smooth muscle cells (PASMCs). Real-time quantitative PCR and Western blotting revealed that treatment with BMP4 (50 ng/ml, 60 h) increased TRPC1, TRPC4, and TRPC6 mRNA and protein expression in growth-arrested rat distal PASMCs. Moreover, in comparison to vehicle control, cells treated with BMP4 also exhibited enhanced SOCE, and elevated basal intracellular calcium concentration ([Ca(2+)](i)) as determined by fluorescent microscopy using the Ca(2+) indicator Fura-2 AM. Perfusing cells with Ca(2+)-free Krebs-Ringer bicarbonate solution (KRBS) or KRBS containing SOCC antagonists SKF-96365 or NiCl(2) attenuated the increases in basal [Ca(2+)](i) caused by BMP4. Specific knockdown of BMP4 by small interference RNA significantly decreased the mRNA and protein expression of TRPC1, TRPC4, and TRPC6 and reduced SOCE and basal [Ca(2+)](i) in serum-stimulated PASMCs. We conclude that BMP4 regulates calcium signaling in PASMCs likely via upregulation of TRPC expression, leading to enhanced SOCE and basal [Ca(2+)](i) in PASMCs, and by this mechanism contributes to pulmonary vascular remodeling during pulmonary arterial hypertension. 10.1152/ajpcell.00040.2010
    Revisiting the mechanism of hypoxic pulmonary vasoconstriction using isolated perfused/ventilated mouse lung. Jain Pritesh P,Hosokawa Susumu,Xiong Mingmei,Babicheva Aleksandra,Zhao Tengteng,Rodriguez Marisela,Rahimi Shamin,Pourhashemi Kiana,Balistrieri Francesca,Lai Ning,Malhotra Atul,Shyy John Y-J,Valdez-Jasso Daniela,Thistlethwaite Patricia A,Makino Ayako,Yuan Jason X-J Pulmonary circulation Hypoxic Pulmonary Vasoconstriction (HPV) is an important physiological mechanism of the lungs that matches perfusion to ventilation thus maximizing O saturation of the venous blood within the lungs. This study emphasizes on principal pathways in the initiation and modulation of hypoxic pulmonary vasoconstriction with a primary focus on the role of Ca signaling and Ca influx pathways in hypoxic pulmonary vasoconstriction. We used an ex vivo model, isolated perfused/ventilated mouse lung to evaluate hypoxic pulmonary vasoconstriction. Alveolar hypoxia (utilizing a mini ventilator) rapidly and reversibly increased pulmonary arterial pressure due to hypoxic pulmonary vasoconstriction in the isolated perfused/ventilated lung. By applying specific inhibitors for different membrane receptors and ion channels through intrapulmonary perfusion solution in isolated lung, we were able to define the targeted receptors and channels that regulate hypoxic pulmonary vasoconstriction. We show that extracellular Ca or Ca influx through various Ca-permeable channels in the plasma membrane is required for hypoxic pulmonary vasoconstriction. Removal of extracellular Ca abolished hypoxic pulmonary vasoconstriction, while blockade of L-type voltage-dependent Ca channels (with nifedipine), non-selective cation channels (with 30 µM SKF-96365), and TRPC6/TRPV1 channels (with 1 µM SAR-7334 and 30 µM capsazepine, respectively) significantly and reversibly inhibited hypoxic pulmonary vasoconstriction. Furthermore, blockers of Ca-sensing receptors (by 30 µM NPS2143, an allosteric Ca-sensing receptors inhibitor) and Notch (by 30 µM DAPT, a γ-secretase inhibitor) also attenuated hypoxic pulmonary vasoconstriction. These data indicate that Ca influx in pulmonary arterial smooth muscle cells through voltage-dependent, receptor-operated, and store-operated Ca entry pathways all contribute to initiation of hypoxic pulmonary vasoconstriction. The extracellular Ca-mediated activation of Ca-sensing receptors and the cell-cell interaction via Notch ligands and receptors contribute to the regulation of hypoxic pulmonary vasoconstriction. 10.1177/2045894020956592