Role of Bone Morphogenetic Protein 4 in Hypoxic Pulmomary Hypertension

骨形态发生蛋白 4 在缺氧性肺动脉高压中的作用

• 批准号: 8251199
• 负责人: Jian Wang
• 金额: $ 36.53万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-01 至 2015-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8251199
• 关键词: ACVR1 gene; Anatomy; Animals; Apoptosis; Attenuated; Behavior; Binding; Biological Assay; Blood Vessels; Bone Morphogenetic Proteins; Calcium; Calcium Signaling; Cell Differentiation process; Cell Proliferation; Cell membrane; Chronic; Chronic lung disease; Complication; Data; Development; Disease; Distal; Exposure to; Family; Family member; Fluorescence Microscopy; Functional disorder; Gene Mutation; Gene Silencing; Generations; Germ-Line Mutation; Growth Factor; Heart failure; Homeostasis; Human; Hypertension; Hypoxia; Investigation; Knock-out; Knockout Mice; Knowledge; Lead; Literature; Lung; MAPK3 gene; Measurement; Mediating; Mediator of activation protein; Methods; Modeling; Molecular; Molecular Abnormality; Molecular Biology; Mus; Oxygen; Pathogenesis; Pathway interactions; Physiological; Play; Prevention; Process; Proteins; Pulmonary Hypertension; Pulmonary artery structure; Rattus; Regulation; Role; Second Messenger Systems; Signal Pathway; Signal Transduction; Small Interfering RNA; Smooth Muscle Myocytes; Stimulus; Subgroup; Techniques; Testing; Transforming Growth Factors; Transgenic Mice; Up-Regulation; Vascular remodeling; base; bone morphogenetic protein 4; bone morphogenetic protein receptor type II; bone morphogenetic protein receptors; cell growth; constriction; hypoxia inducible factor 1; improved; knowledge of results; mRNA Expression; member; mortality; mouse model; overexpression; pressure; protein expression; public health relevance; pulmonary arterial hypertension; receptor; research study; response; second messenger; tool; transcription factor; vasoconstriction

DESCRIPTION (provided by applicant): Chronic hypoxia (CH)-induced sustained increases in vascular tone and pulmonary vascular remodeling play key roles in the pathogenesis of chronic hypoxic pulmonary hypertension (CHPH). Despite progresses have been made on exploring the role of Ca2+ in these processes, the underlying molecular mechanisms, however, remain largely unknown. Bone morphogenetic proteins (BMPs), a subgroup of the transforming growth factor-2 (TGF-2) superfamily, are known as critical regulators in mammalian development, cell proliferation, differentiation and apoptosis. Recently, the identification of germline mutation of BMP receptor II (BMPRII) in familial pulmonary hypertension and other associated group of evidence indicate the implication of abnormal BMP signaling in the pathogenesis of pulmonary hypertension. In particular, ug-regulation of bone morphogenetic protein 4 (BMP4) by CH was suggested to be an important factor that influences the development of CHPH. We previously demonstrated that CH elevated basal intracellular [Ca2+] ([Ca2+]i) in pulmonary arterial smooth muscle cells (PASMCs) due in large part to enhanced store-operated calcium entry (SOCE) through store-operated Ca2+ channels (SOCCs) likely composed of canonical transient receptor potential proteins (TRPCs). In our recent studies, we obtained data showing a role of BMP4 in regulation of TRPCs expression and Ca2+ influx. These data include: 1) BMP4 treatment increased TRPC1 and TRPC6 expression, SOCE and basal [Ca2+]i in PASMCs; 2) Exposure to CH increased mRNA and protein expression of TRPC1 and TRPC6, SOCE and basal [Ca2+]i in PASMCs, and these CH-induced increases were attenuated by knockdown of BMP4 expression via specific BMP4 siRNA, or BMP4 depletion using its antagonist noggin; 2) CH enhanced both mRNA and protein expressions of BMP4 in mouse lung; 3) Overexpression of HIF-1a increased BMP4 expression in PASMCs, and the CH-induced increases of BMP4 expression were impaired in HIF-1a partially deficient mice. These results suggest that BMP4 participate in the regulation of Ca2+ homeostasis in PASMCs during CH via modulation of TRPC channels, acting either in downstream of HIF-1a or in concert with HIF-1a dependent up-regulation of TRPCs. On the basis of the above findings and some other data in our studies, we hypothesize that the increased [Ca2+]i in PASMCs caused by CH is due to or partially due to HIF-1 dependent upregulation of BMP4, which leads to increases in TRPCs expression, SOCE and basal [Ca2+]i in distal PASMCs, thereby contributing to CHPH. To test this hypothesis, we will perform experiments in lung, PA and/or PASMCs using the combined techniques of microfluorescence measurements and molecular biology to accomplish the following specific aims: 1) Determine the roles of HIF-1 and BMP4 in up-regulation of TRPCs expression during CH; 2) Determine BMP4 receptors and antagonist(s) that are responsible for hypoxic increases of TRPCs expression; 3) Determine the signaling pathway through which BMP4 regulates TRPCs expression in PASMCs; 4) Determine which TRPC contributes to the increases of SOCE and basal [Ca2+]i in response to CH. PUBLIC HEALTH RELEVANCE: Pulmonary hypertension (PH) is a progressive devastating disease characterized by high blood pressure in the lungs; its mechanisms remain poorly understood. Hypoxia, an important trigger of PH, has been found to enhance calcium signaling in pulmonary artery smooth muscle cells, causing cell proliferation and constriction. Our study focuses on investigation of whether and how BMP4 regulates this process, which, if successful, will lead to improved methods of pharmacological prevention and treatment of this lethal complication of chronic lung diseases.

描述（由申请人提供）：慢性缺氧（CH）引起的血管张力和肺血管重塑的持续增加在慢性低氧肺动脉高压（CHPH）的发病机理中起关键作用。尽管在探索Ca2+在这些过程中的作用方面取得了进展，但是基本的分子机制仍然在很大程度上未知。骨形态发生蛋白（BMP）是转化生长因子2（TGF-2）超家族的亚组，被称为哺乳动物发育，细胞增殖，分化和凋亡中的关键调节剂。最近，BMP受体II（BMPRII）在家族性肺动脉高压和其他相关证据组中的种系突变鉴定表明BMP信号异常在肺动脉高压的发病机理中的意义。特别是，CH对骨形态发生蛋白4（BMP4）的UG调节被认为是影响CHPH发展的重要因素。我们先前证明了CH升高的肺部动脉平滑肌细胞（PASMC）在很大程度上升高了基础细胞内[CA2+]（[Ca2+] I），这在很大程度上是由于商店操作的CA2+通道（SOCC）的增强，可能会增加商店经营的CA2+通道（SOCC）。在最近的研究中，我们获得了显示BMP4在TRPCS表达和Ca2+涌入调节中的作用的数据。这些数据包括：1）BMP4处理增加了TRPC1和TRPC6的表达，SOCE和基础[Ca2+] I在PASMC中； 2）暴露于PASMC中TRPC1和TRPC6，SOCE和基础[Ca2+] I的MRNA和蛋白质表达的增加，并且通过使用其拮抗剂Noggin通过特定的BMP4 siRNA或BMP4 deptettion敲低BMP4表达来减弱这些CH诱导的增加。 2）CH增强了小鼠肺中BMP4的mRNA和蛋白质表达； 3）HIF-1A的过表达增加了PASMC中BMP4的表达，并且在HIF-1A部分缺乏小鼠中，CH诱导的BMP4表达的增加受损。这些结果表明，BMP4通过调节TRPC通道在CH期间参与PASMC中Ca2+稳态的调节，在HIF-1A的下游或与HIF-1A依赖于TRPC的上调一起起作用。根据上述发现和我们的研究中的其他一些数据，我们假设由CH引起的PASMC中的[Ca2+] I增加是由于或部分归因于BMP4的HIF-1依赖性上调，这导致TRPCS表达，SOCE和基础[Ca2+] I在远程PASMC中的增加，在此中，CHPH供应CHPH。为了检验这一假设，我们将使用微荧光测量和分子生物学的组合技术在肺，PA和/或PASMC中进行实验，以实现以下特定目的：1）确定HIF-1和BMP4在CH期间TRPC表达上上调的作用； 2）确定导致TRPC表达低氧增加的BMP4受体和拮抗剂； 3）确定BMP4通过该信号通路调节PASMC中TRPC的表达； 4）确定哪种TRPC响应CH，有助于SOCE和基础[Ca2+] I的增加。 公共卫生相关性：肺动脉高压（PH）是一种进行性毁灭性疾病，其特征是肺部高血压；它的机制仍然很少理解。缺氧是pH值的重要触发因素，可增强肺动脉平滑肌细胞中的钙信号传导，从而导致细胞增殖和收缩。我们的研究重点是研究BMP4是否调节这一过程，如果成功的话，这将导致改进的药理学预防方法和治疗慢性肺部疾病的致命并发症的治疗方法。