title: Inhibition of FHL1 inhibits cigarette smoke extract-induced proliferation in pulmonary arterial smooth muscle cells.
abstract: Cigarette smoke can induce pulmonary vascular remodeling, which involves pulmonary artery smooth muscle cell (PASMC) proliferation, resulting in pulmonary hypertension in chronic obstructive pulmonary disease. FHL1 is a member of the FHL subfamily, characterized by an N‑terminal half LIM domain, followed by four complete LIM domains, and has been suggested to be critical in cell proliferation. However, the effects of FHL1 on cigarette smoke‑induced PASMC proliferation and the precise molecular mechanism remain to be elucidated. The present study demonstrated that the protein expression of FHL1 correlated with cigarette smoke extract (CSE)‑induced PASMC proliferation. Knockdown of the expression of FHL1 using siRNA significantly suppressed cell proliferation and inhibited the cell cycle transition between the G1 and S phase by regulating the cyclin‑dependent kinase pathway at the basal level and following CSE stimulation. By contrast, overexpressing FHL1 using an adenovirus increased cell proliferation and promoted the cell cycle transition between the G1 and S phase. Furthermore, CSE significantly increased the protein expression of FHL1, however, exerted no effect on the mRNA expression levels. This alteration was due to the prolonged FHL1 half‑life, leading to the antagonizing of protein degradation. Collectively, these data suggested that FHL1 may be involved in excessive cell proliferation and may represent a potential therapeutic target for pulmonary hypertension.
authors.affiliation: Department of Respiratory Medicine, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China.
authors.forename: Yuping
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Respiratory Medicine, Shaoxing People's Hospital, Shaoxing, Zhejiang 312000, P.R. China.
authors.forename: Guimei
authors.initials: G
authors.lastname: Pu
authors.affiliation: Department of Respiratory Medicine, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China.
authors.forename: Chengshui
authors.initials: C
authors.lastname: Chen
authors.affiliation: Department of Respiratory Medicine, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China.
authors.forename: Li
authors.initials: L
authors.lastname: Yang
mesh_terms: D000818:Animals; D017209:Apoptosis; D049109:Cell Proliferation; D059585:G1 Phase Cell Cycle Checkpoints; D006976:Hypertension, Pulmonary / Q000209:etiology / Q000378:metabolism*; D060588:LIM Domain Proteins / Q000235:genetics / Q000378:metabolism*; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000473:pathology; D032389:Myocytes, Smooth Muscle / Q000378:metabolism*; D055550:Protein Stability; D011651:Pulmonary Artery / Q000378:metabolism / Q000473:pathology*; D051381:Rats; D012907:Smoking / Q000009:adverse effects*; D015533:Transcriptional Activation
chemical_list: C517184:Fhl1 protein, rat; D060588:LIM Domain Proteins; D009124:Muscle Proteins