{"title":"5-Aminoimidazole-4-carboxamide ribonucleotide formyltransferase/inosine monophosphate cyclohydrolase promotes pulmonary arterial smooth muscle cell proliferation via the Ras signaling pathway.","authors":"Xiaofan Shi, Qian Ma, Yuqing Huo, Yunchao Su","doi":"10.1152/ajpcell.00262.2024","DOIUrl":null,"url":null,"abstract":"<p><p>Pulmonary arterial hypertension (PAH) is a debilitating vascular disorder characterized by abnormal pulmonary artery smooth muscle cell (PASMC) proliferation and collagen synthesis, contributing to vascular remodeling and elevated pulmonary vascular resistance. This study investigated the critical role of 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/inosine monophosphate cyclohydrolase (ATIC) in cell proliferation and collagen synthesis in PASMCs in PAH. Here we show that ATIC levels are significantly increased in the lungs of monocrotaline (MCT)-induced PAH rat model, hypoxia-induced PAH mouse model, and platelet-derived growth factor (PDGF)-stimulated PASMCs. Inhibition of ATIC attenuated PDGF-induced cell proliferation and collagen I synthesis in PASMCs. Conversely, overexpression or knockdown of ATIC causes a significant promotion or inhibition of Ras and ERK activation, cell proliferation, and collagen synthesis in PASMCs. Moreover, ATIC deficiency attenuated Ras activation in the lungs of hypoxia-induced PAH mice. Furthermore, Ras inhibition attenuates ATIC overexpression- and PDGF-induced collagen synthesis and PASMC proliferation. Notably, we identified that transcription factors MYC, early growth response protein 1 (EGR1), and specificity protein 1 (SP1) directly binds to promoters of <i>Atic</i> gene and regulate ATIC expression. These results provide the first evidence that ATIC promotes PASMC proliferation in pulmonary vascular remodeling through the Ras signaling pathway.<b>NEW & NOTEWORTHY</b> Our findings highlight the important role of ATIC in the PASMC proliferation of pulmonary vascular remodeling through its modulation of the Ras signaling pathway and its regulation by transcription factors MYC, EGR1, and SP1. ATIC's modulation of Ras signal pathway represents a novel mechanism contributing to PAH development.</p>","PeriodicalId":7585,"journal":{"name":"American journal of physiology. Cell physiology","volume":null,"pages":null},"PeriodicalIF":5.0000,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11481986/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"American journal of physiology. Cell physiology","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1152/ajpcell.00262.2024","RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/8/12 0:00:00","PubModel":"Epub","JCR":"Q2","JCRName":"CELL BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Pulmonary arterial hypertension (PAH) is a debilitating vascular disorder characterized by abnormal pulmonary artery smooth muscle cell (PASMC) proliferation and collagen synthesis, contributing to vascular remodeling and elevated pulmonary vascular resistance. This study investigated the critical role of 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/inosine monophosphate cyclohydrolase (ATIC) in cell proliferation and collagen synthesis in PASMCs in PAH. Here we show that ATIC levels are significantly increased in the lungs of monocrotaline (MCT)-induced PAH rat model, hypoxia-induced PAH mouse model, and platelet-derived growth factor (PDGF)-stimulated PASMCs. Inhibition of ATIC attenuated PDGF-induced cell proliferation and collagen I synthesis in PASMCs. Conversely, overexpression or knockdown of ATIC causes a significant promotion or inhibition of Ras and ERK activation, cell proliferation, and collagen synthesis in PASMCs. Moreover, ATIC deficiency attenuated Ras activation in the lungs of hypoxia-induced PAH mice. Furthermore, Ras inhibition attenuates ATIC overexpression- and PDGF-induced collagen synthesis and PASMC proliferation. Notably, we identified that transcription factors MYC, early growth response protein 1 (EGR1), and specificity protein 1 (SP1) directly binds to promoters of Atic gene and regulate ATIC expression. These results provide the first evidence that ATIC promotes PASMC proliferation in pulmonary vascular remodeling through the Ras signaling pathway.NEW & NOTEWORTHY Our findings highlight the important role of ATIC in the PASMC proliferation of pulmonary vascular remodeling through its modulation of the Ras signaling pathway and its regulation by transcription factors MYC, EGR1, and SP1. ATIC's modulation of Ras signal pathway represents a novel mechanism contributing to PAH development.
期刊介绍:
The American Journal of Physiology-Cell Physiology is dedicated to innovative approaches to the study of cell and molecular physiology. Contributions that use cellular and molecular approaches to shed light on mechanisms of physiological control at higher levels of organization also appear regularly. Manuscripts dealing with the structure and function of cell membranes, contractile systems, cellular organelles, and membrane channels, transporters, and pumps are encouraged. Studies dealing with integrated regulation of cellular function, including mechanisms of signal transduction, development, gene expression, cell-to-cell interactions, and the cell physiology of pathophysiological states, are also eagerly sought. Interdisciplinary studies that apply the approaches of biochemistry, biophysics, molecular biology, morphology, and immunology to the determination of new principles in cell physiology are especially welcome.