Pro-apoptotic effects of imatinib on PDGF-stimulated pulmonary artery smooth muscle cells from patients with idiopathic pulmonary arterial hypertension

• Published in: International journal of cardiology 2012-08, Vol.159 (2), p.100-106
• Main Authors: Nakamura, Kazufumi, Akagi, Satoshi, Ogawa, Aiko, Kusano, Kengo F, Matsubara, Hiromi, Miura, Daiji, Fuke, Soichiro, Nishii, Nobuhiro, Nagase, Satoshi, Kohno, Kunihisa, Morita, Hiroshi, Oto, Takahiro, Yamanaka, Ryutaro, Otsuka, Fumio, Miura, Aya, Yutani, Chikao, Ohe, Tohru, Ito, Hiroshi
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Apoptosis; Apoptosis - drug effects; Apoptosis - physiology; Arterial hypertension. Arterial hypotension; Benzamides - pharmacology; Biological and medical sciences; Blood and lymphatic vessels; Cardiology. Vascular system; Cardiovascular; Cell Proliferation - drug effects; Child; Familial Primary Pulmonary Hypertension; Female; Humans; Hypertension; Hypertension, Pulmonary - drug therapy; Hypertension, Pulmonary - pathology; Imatinib Mesylate; Male; Medical sciences; Myocytes, Smooth Muscle - drug effects; Myocytes, Smooth Muscle - physiology; Piperazines - pharmacology; Pneumology; Proto-Oncogene Proteins c-sis - antagonists & inhibitors; Proto-Oncogene Proteins c-sis - pharmacology; Pulmonary; Pulmonary Artery - cytology; Pulmonary Artery - drug effects; Pulmonary Artery - physiology; Pulmonary hypertension. Acute cor pulmonale. Pulmonary embolism. Pulmonary vascular diseases; Pyrimidines - pharmacology; Remodeling; Treatment Outcome; Young Adult
• ISSN: 0167-5273; 1874-1754
• DOI: 10.1016/j.ijcard.2011.02.024

Abstract Background Remodeling of the pulmonary artery by an inappropriate increase of pulmonary artery smooth muscle cells (PASMCs) is problematic in the treatment of idiopathic pulmonary arterial hypertension (IPAH). Effective treatment that achieves reverse remodeling is required. The aim of this study was to assess the pro-apoptotic effects of imatinib, a platelet-derived growth factor (PDGF)-receptor tyrosine kinase inhibitor, on PASMCs obtained from patients with IPAH. Methods PASMCs were obtained from 8 patients with IPAH undergoing lung transplantation. Cellular proliferation was assessed by3 H-thymidine incorporation. Pro-apoptotic effects of imatinib were examined using TUNEL and caspase-3,7 assays and using transmission electron microscopy. Results Treatment with imatinib (0.1 to 10 μg/mL) significantly inhibited PDGF-BB (10 ng/mL)-induced proliferation of PASMCs from IPAH patients. Imatinib (1 μg/mL) did not induce apoptosis in quiescent IPAH-PASMCs, but it had a pro-apoptotic effect on IPAH-PASMCs stimulated with PDGF-BB. Imatinib did not induce apoptosis in normal control PASMCs with or without PDGF-BB stimulation. PDGF-BB induced phosphorylation of Akt at 15 min, and Akt phosphorylation was inhibited by imatinib in IPAH-PASMCs. Akt-I-1/2 (1 μmol/L), an Akt inhibitor, in the presence of PDGF-BB significantly increased apoptotic cells compared with the control condition. Thus, Akt-I-1/2 could mimic the effects of imatinib on PASMCs. Conclusion Imatinib has anti-proliferative and pro-apoptotic effects on IPAH-PASMCs stimulated with PDGF. The inhibitory effect of imatinib on Akt phosphorylation induced by PDGF plays an important role in the pro-apoptotic effect.