Yuhu He1,2,3, Caojian Zuo3,4, Daile Jia3,5, Peiyuan Bai3,5, Deping Kong1, Di Chen3, Guizhu Liu6, Juanjuan Li3, Yuanyang Wang1, Guilin Chen1, Shuai Yan3, Bing Xiao3, Jian Zhang1, Lingjuan Piao3, Yanli Li1, Yi Deng1, Bin Li7, Philippe P Roux8,9, Katrin I Andreasson10, Richard M Breyer11,12, Yunchao Su13, Jian Wang6, Ankang Lyu5, Yujun Shen1, Ying Yu1,3,6. 1. Department of Pharmacology, Tianjin Key Laboratory of Inflammation Biology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China. 2. Department of Cardiovascular Medicine, Second Xiangya Hospital, Central South University, Changsha, Hunan, China. 3. Chinese Academy of Sciences Key Laboratory of Nutrition, Metabolism and Food Safety, Shanghai Institute of Nutrition and Health, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China. 4. Department of Cardiology, Shanghai General Hospital, and. 5. Department of Cardiology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China. 6. State Key Laboratory of Respiratory Diseases, Guangzhou Institute of Respiratory Health, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China. 7. Orthopedic Institute, Soochow University, Jiangsu, China. 8. Institute for Research in Immunology and Cancer and. 9. Department of Pathology and Cell Biology, University of Montreal, Montreal, Quebec, Canada. 10. Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California. 11. Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, Tennessee. 12. Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee; and. 13. Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, Georgia.
Abstract
Rationale: Vascular remodeling, including smooth muscle cell hypertrophy and proliferation, is the key pathological feature of pulmonary arterial hypertension (PAH). Prostaglandin I2 analogs (beraprost, iloprost, and treprostinil) are effective in the treatment of PAH. Of note, the clinically favorable effects of treprostinil in severe PAH may be attributable to concomitant activation of DP1 (D prostanoid receptor subtype 1). Objectives: To study the role of DP1 in the progression of PAH and its underlying mechanism. Methods: DP1 levels were examined in pulmonary arteries of patients and animals with PAH. Multiple genetic and pharmacologic approaches were used to investigate DP1-mediated signaling in PAH.Measurements and Main Results: DP1 expression was downregulated in hypoxia-treated pulmonary artery smooth muscle cells and in pulmonary arteries from rodent PAH models and patients with idiopathic PAH. DP1 deletion exacerbated pulmonary artery remodeling in hypoxia-induced PAH, whereas pharmacological activation or forced expression of the DP1 receptor had the opposite effect in different rodent models. DP1 deficiency promoted pulmonary artery smooth muscle cell hypertrophy and proliferation in response to hypoxia via induction of mTORC1 (mammalian target of rapamycin complex 1) activity. Rapamycin, an inhibitor of mTORC1, alleviated the hypoxia-induced exacerbation of PAH in DP1-knockout mice. DP1 activation facilitated raptor dissociation from mTORC1 and suppressed mTORC1 activity through PKA (protein kinase A)-dependent phosphorylation of raptor at Ser791. Moreover, treprostinil treatment blocked the progression of hypoxia-induced PAH in mice in part by targeting the DP1 receptor.Conclusions: DP1 activation attenuates hypoxia-induced pulmonary artery remodeling and PAH through PKA-mediated dissociation of raptor from mTORC1. These results suggest that the DP1 receptor may serve as a therapeutic target for the management of PAH.
Rationale: Vascular remodeling, including smooth muscle cell hypertrophy and proliferation, is the key pathological feature of pulmonary arterial hypertension (PAH). Prostaglandin I2 analogs (beraprost, iloprost, and treprostinil) are effective in the treatment of PAH. Of note, the clinically favorable effects of treprostinil in severe PAH may be attributable to concomitant activation of DP1 (D prostanoid receptor subtype 1). Objectives: To study the role of DP1 in the progression of PAH and its underlying mechanism. Methods:DP1 levels were examined in pulmonary arteries of patients and animals with PAH. Multiple genetic and pharmacologic approaches were used to investigate DP1-mediated signaling in PAH.Measurements and Main Results:DP1 expression was downregulated in hypoxia-treated pulmonary artery smooth muscle cells and in pulmonary arteries from rodent PAH models and patients with idiopathic PAH. DP1 deletion exacerbated pulmonary artery remodeling in hypoxia-induced PAH, whereas pharmacological activation or forced expression of the DP1 receptor had the opposite effect in different rodent models. DP1 deficiency promoted pulmonary artery smooth muscle cell hypertrophy and proliferation in response to hypoxia via induction of mTORC1 (mammalian target of rapamycin complex 1) activity. Rapamycin, an inhibitor of mTORC1, alleviated the hypoxia-induced exacerbation of PAH in DP1-knockout mice. DP1 activation facilitated raptor dissociation from mTORC1 and suppressed mTORC1 activity through PKA (protein kinase A)-dependent phosphorylation of raptor at Ser791. Moreover, treprostinil treatment blocked the progression of hypoxia-induced PAH in mice in part by targeting the DP1 receptor.Conclusions: DP1 activation attenuates hypoxia-induced pulmonary artery remodeling and PAH through PKA-mediated dissociation of raptor from mTORC1. These results suggest that the DP1 receptor may serve as a therapeutic target for the management of PAH.
Authors: Kathryn G Foster; Hugo A Acosta-Jaquez; Yves Romeo; Bilgen Ekim; Ghada A Soliman; Audrey Carriere; Philippe P Roux; Bryan A Ballif; Diane C Fingar Journal: J Biol Chem Date: 2009-10-28 Impact factor: 5.157