JOURNAL OF SHANGHAI JIAOTONG UNIVERSITY (MEDICAL SCIENCE) ›› 2021, Vol. 41 ›› Issue (2): 129-133.doi: 10.3969/j.issn.1674-8115.2021.02.001

• Basic research • Previous Articles     Next Articles

Protective effect of pituitary adenylate cyclase-activating polypeptide 38 on acute radiation-induced myocardial injury

Huan LI1(), Pei-qiang YI1, Jun SU1, Pei-zhan CHEN2, Cheng XU1, Lu CAO1, Jia-yi CHEN1, Min LI1()   

  1. 1.Department of Radiation Oncology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
    2.Clinical Research Center, Ruijin Hospital North, Shanghai Jiao Tong University School of Medicine, Shanghai 201801, China
  • Received:2020-06-01 Online:2021-02-28 Published:2021-02-28
  • Contact: Min LI E-mail:lihuan3579@163.com;lm11866@rjh.com.cn
  • Supported by:
    National Key Research and Development Program of China(2016YFC0105409);National Natural Science Foundation of China(81602791);Scientific and Technological Innovation Action Plan of Science and Technology Commission of Shanghai Municipality(19411950900);Shanghai Municipal Education Commission—Gaofeng Clinical Medicine Grant Support(20171904)

Abstract: Objective

·To explore the effect of pituitary adenylate cyclase-activating polypeptide 38 (PACAP38) on radiosensitivity of myocardial cells and its potential protective effect on acute radiation-induced myocardial injury.

Methods

·The radiation-related cardiac injury models were established by using 6 MV X-ray with H9C2 cardiomyocytes and male C57BL/6J mice which were pre-treated with different doses of PACAP38 prior to radiation exposure. H9C2 cells were treated with 10-9 and 10-7 mol/L PACAP38 2 h before irradiation. 10 μg of 0.1 μg/μL PACAP38 was administered to C57BL/6J mice intraperitoneally at 2 h before irradiation and additional doses were given at 24 h and 48 h after irradiation. In vivo and in vitro myocardial radiation injury models were divided into control group, PACAP38 group, irradiation group (IR) and PACAP38+IR group. The specific irradiation doses in vitro were 2, 4, 8 and 12 Gy. The specific irradiation dose in vivo were 14 Gy, one fraction irradiation. CCK-8 and clonogenesis assays were used to examine cell viability and radiosensitivity, respectively. Hematoxylin and eosin staining was used to evaluate the pathological changes of myocardial tissue in mice after one-month irradiation.

Results

·The cell viability of H9C2 cardiomyocytes pretreated with PACAP38 was significantly higher than that of irradiation (12 Gy) alone [10-7 mol/L PACAP38+IR group vs IR group, (98.63±2.70)% vs (83.67±0.78)%, P=0.000]. The survival fraction at 2 Gy increased from 0.53 to 0.63 and 0.70 after 10-9 and 10-7 mol/L PACAP38 pretreatment, and the sensitivity enhancement ratio of 10-9 and 10-7 mol/L PACAP38 pretreatment groups were 0.95 and 0.91, respectively. In vivo studies showed that PACAP38 could significantly alleviate the pathological damage of myocardial tissue after irradiation (14 Gy), including cardiomyocyte degeneration, eosinophilic enhancement, cytoplasmic vacuolation, nuclear pyknosis and myocardial fiber distortion.

Conclusion

·PACAP38 can significantly reduce the radiosensitivity of myocardial cells and has a certain protective effect on acute radiation-induced myocardial injury.

Key words: pituitary adenylate cyclase-activating polypeptide 38 (PACAP38), irradiation model, radiation-induced myocardial injury, cardioprotectant

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