Erythroblast transformation-specific 2 correlates with vascular smooth muscle cell apoptosis in rat heterotopic heart transplantation model.
BACKGROUND
Cardiac allograft vasculopathy (CAV) decreases the long-term survival of heart transplantation recipients. Vascular smooth muscle cell (VSMC) apoptosis is an important pathological feature of CAV. Erythroblast transformation-specific 2 (Ets-2), as a transcription factor, participates in cell apoptosis and plays an important role in organ transplantation.


METHODS
Hearts from Wistar-Furth (WF:RT1u) rats were heterotopically transplanted into Lewis (Lew:RT1(l)) rats without immunosuppression. Additional syngeneic heterotopic cardiac transplantations were performed in Lewis rats. HE staining was used to identify CAV. Ets-2 expression was examined by western blot. Ets-2 tissue location was examined by immunohistochemical assay and double immunostaining. Cleaved caspase 3 expression was detected by western blot. Co-localization of Ets-2 and cleaved caspase 3 was detected by double immunostaining. Ets-2, p53, cleaved caspase 3 and Bcl-xl expression in rat VSMC line A7R5 was examined after Ets-2 siRNA transfection. TUNEL assay was applied to detect A7R5 apoptosis with or without ETS-2 siRNA transfection. Immunoprecipitation was performed to explore the interaction between Ets-2 and p53.


RESULTS
Ets-2 expression decreased in the allograft group but had no obvious change in the isograft group. Meanwhile, the phenomenon of CAV was observed in the allograft group and there is neointima formation in the isograft group which is not obvious compared with allograft group. Additionally, Ets-2 expression was opposite to VSMC apoptosis in the allograft group. In vitro, Ets-2 siRNA transfection in A7R5cells resulted in enhanced cell apoptosis. Finally, Ets-2 interacted with p53.


CONCLUSIONS
Ets-2 might inhibit VSMC apoptosis via p53 pathway. The results further elucidate the molecular mechanism of VSMC apoptosis after heart transplantation during CAV and provide theoretical basis for seeking new specific drug targets for CAV prevention and treatment.
Department of Pathogen Biology, Medical College, Nantong University, Nantong 226001, China;; Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College, Nantong University, Nantong 226001, China;
Xiaojuan
X
Liu
Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College, Nantong University, Nantong 226001, China;; Department of Thoracic Surgery, Affiliated Hospital of Nantong University, Nantong 226001, China;
Daliang
D
Yan
Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College, Nantong University, Nantong 226001, China;; Department of Thoracic Surgery, Affiliated Cancer Hospital of Nantong University, Nantong 226361, China;
Yangcheng
Y
Li
Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College, Nantong University, Nantong 226001, China;; Department of Thoracic Surgery, Rugao People's Hospital, Rugao 226500, China;
Xilin
X
Sha
Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College, Nantong University, Nantong 226001, China;; Department of Thoracic Surgery, Affiliated Hospital of Nantong University, Nantong 226001, China;
Kunpeng
K
Wu
Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College, Nantong University, Nantong 226001, China;; Department of Thoracic Surgery, Affiliated Hospital of Nantong University, Nantong 226001, China;
Jianhua
J
Zhao
Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College, Nantong University, Nantong 226001, China;; Department of Thoracic Surgery, Affiliated Hospital of Nantong University, Nantong 226001, China;
Chen
C
Yang
Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College, Nantong University, Nantong 226001, China;; Department of Vasculocardiology, Affiliated Hospital of Nantong University, Nantong 226001, China.
Chao
C
Zhang
Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College, Nantong University, Nantong 226001, China;; Department of Thoracic Surgery, Affiliated Hospital of Nantong University, Nantong 226001, China;
Jiahai
J
Shi
Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College, Nantong University, Nantong 226001, China;; Department of Vasculocardiology, Affiliated Hospital of Nantong University, Nantong 226001, China.
Xiang
X
Wu
Cardiac transplantation; cardiac allograft vasculopathy (CAV); erythroblast transformation-specific 2 (Ets-2); vascular smooth muscle cell apoptosis (VSMC apoptosis)