Idiopathic pulmonary arterial hypertension (IPAH) is a progressive and fatal disease. Sustained pulmonary vasoconstriction and vascular remodeling are the major causes for the elevated PVR and PAP in IPAH patients. An increase in cytosolic Ca ([Ca ]cyt) in pulmonary arterial smooth muscle cells (PASMC) is a major 2+ 2+ trigger for pulmonary vasoconstriction and for pulmonary vascular remodeling due to its stimulatory effect on PASMC proliferation and migration. Abnormally enhanced Ca2+ entry in PASMC because of upregulated expression of membrane receptors (e.g., CaSR) and Ca2+ channels (e.g., TRPC6/C3) contributes to the development and progression of PAH. Downregulation of voltage-gated K+ (Kv) channel expression and decrease in Kv currents (IK(V)) in PASMC contribute to a) increasing PASMC contraction, proliferation and migration by inducing membrane depolarization that opens voltage-dependent Ca2+ channels and raises [Ca ]cyt and b) inhibiting PASMC apoptosis by attenuating apoptotic volume decrease (AVD) and maintaining 2+ high [K ]cyt to inhibit caspases. Enhanced PASMC proliferation and inhibited PASMC apoptosis both contribute + to pulmonary vascular wall thickening. Our data show that selectively increased miRNAs are involved in posttranscriptionally downregulating Kv channels to stimulate PASMC proliferation and inhibit PASMC apoptosis in IPAH patients. Ca2+-sensing receptor (CaSR), a G protein-coupled receptor that can be activated by extracellular Ca2+, is upregulated in IPAH-PASMC compared to normal PASMC. Activation of CaSR in IPAH-PASMC induces receptor-operated Ca entry (ROCE) via diacylglycerol (DAG), while IP3-mediate active 2+ depletion of Ca2+ from the SR results in store-operated Ca2+ entry (SOCE). Extracellular Ca2+-induced CaSR activation also inhibits Kv channels and activate other signal transduction pathways to induce cell proliferation. The overall goal of this research program is to continue to investigate: i) the molecular and cellular mechanisms involved in the posttranscriptional downregulation of Kv channels and other K+ channels by miRNAs that are enhanced in PASMC from IPAH patients; ii) the genetic and molecular mechanisms responsible for the transcriptional upregulation of CaSR and receptor-operated (ROC) and store-operated (SOC) Ca2+ channels (e.g., TRPC3/C6, TRPV1, Orai1/2 and STIM1/2) in PASMC from IPAH patients; iii) the cellular and pathophysiological mechanisms involved in the CaSR-mediated functional activation of TRPC/Orai channels (and STIM1/2 oligomerization and translocation) and functional inhibition of Kv channels in PASMC from IPAH patients; and iv) the potential targets involved in the pathogenic Ca2+ signaling that can be used to develop novel therapy or combination therapy for PAH. Our laboratory has extensive research and technical experience in studying pathogenic mechanisms of IPAH and pulmonary hypertension associated with hypoxic lung disease. The forthcoming results from these studies will provide highly impactful insights into developing novel therapies for IPAH and other forms of pulmonary hypertension.
Idiopathic pulmonary arterial hypertension (IPAH) is a rare and fatal disease that predominantly affects young women. Abnormalities in pulmonary arteries, the blood vessels in the lungs, have been shown to relate to the elevated blood pressure in the lungs. This study is designed to determine the role of receptors and ion channels, proteins on cell membrane that mediate cell growth and mobility in the cellular processes that lead to the high blood pressure in the lungs in patients with this devastating disease, and to reveal potential novel targets for therapeutic approaches to treat IPAH.
|Gross, Christine M; Kellner, Manuela; Wang, Ting et al. (2018) LPS-induced Acute Lung Injury Involves NF-?B-mediated Downregulation of SOX18. Am J Respir Cell Mol Biol 58:614-624|
|Miao, Ran; Wan, Jun; Liu, Jie et al. (2018) Bone Marrow-Derived Endothelial Progenitor Cells Contribute to Monocrotaline-Induced Pulmonary Arterial Hypertension in Rats via Inhibition of Store-Operated Ca2+ Channels. Biomed Res Int 2018:4892349|
|Dai, Jingbo; Zhou, Qiyuan; Tang, Haiyang et al. (2018) Smooth muscle cell-specific FoxM1 controls hypoxia-induced pulmonary hypertension. Cell Signal 51:119-129|
|O'Donnell, Martha E; Yuan, Jason X-J (2018) Pathophysiology of stroke: the many and varied contributions of brain microvasculature. Am J Physiol Cell Physiol 315:C341-C342|
|Delpire, Eric; Hamilton, Kirk L; Hawke, Thomas J et al. (2018) AJP-Cell Physiology begins landmark reviews in cell physiology: an editorial from the senior editors of AJP-Cell Physiology. Am J Physiol Cell Physiol 314:C1-C2|
|Tang, Haiyang; Babicheva, Aleksandra; McDermott, Kimberly M et al. (2018) Endothelial HIF-2? contributes to severe pulmonary hypertension due to endothelial-to-mesenchymal transition. Am J Physiol Lung Cell Mol Physiol 314:L256-L275|
|He, Xi; Song, Shanshan; Ayon, Ramon J et al. (2018) Hypoxia selectively upregulates cation channels and increases cytosolic [Ca2+] in pulmonary, but not coronary, arterial smooth muscle cells. Am J Physiol Cell Physiol 314:C504-C517|
|Song, Shanshan; Carr, Shane G; McDermott, Kimberly M et al. (2018) STIM2 (Stromal Interaction Molecule 2)-Mediated Increase in Resting Cytosolic Free Ca2+ Concentration Stimulates PASMC Proliferation in Pulmonary Arterial Hypertension. Hypertension 71:518-529|
|Wang, Ziyi; Yang, Kai; Zheng, Qiuyu et al. (2018) Divergent Changes of p53 in Pulmonary Arterial Endothelial and Smooth Muscle Cells Involved in the Development of Pulmonary Hypertension. Am J Physiol Lung Cell Mol Physiol :|
|Kurdyukov, Sergey; Eccles, Cody A; Desai, Ankit A et al. (2018) New cases of Glucose-6-Phosphate Dehydrogenase deficiency in Pulmonary Arterial Hypertension. PLoS One 13:e0203493|
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