title: Ulinastatin protects cardiomyocytes against ischemia‑reperfusion injury by regulating autophagy through mTOR activation.
abstract: Autophagy is significant in myocardial ischemia-reperfusion (IR) injury. Ulinastatin has been demonstrated to protect cardiomyocytes against IR through inducing anti-inflammatory effects. However, whether ulinastatin has an anti‑autophagic effect is yet to be elucidated. The present study aimed to investigate the effect of ulinastatin on the regulation of autophagy during IR injury. Cardiomyocytes of neonatal rats were randomly divided into control, hypoxia-reoxygenation (HR) and ulinastatin groups. In order to investigate whether mammalian target of rapamycin (mTOR) is involved in mediating the protective effect of ulinastatin, cells were treated with the mTOR inhibitor, rapamycin 30 min prior to ulinastatin treatment. To demonstrate the anti-autophagic effect of ulinastatin in vivo, a rat IR model was established. Ulinastatin (1x104 U/kg body weight) was administered 30 min prior to the induction of IR via peritoneal injection. Light chain 3 (LC3), phosphorylated (p)‑mTOR, p‑protein kinase B (Akt) and p‑P70S6 kinase (p‑P70S6K) protein expression were assessed using western blot analysis. In addition, cell vitality, myocardial infarct size and lactate dehydrogenase (LDH) levels were measured. LC3‑Ⅱ protein expression was found to be downregulated, while p‑Akt, p‑mTOR and p‑P70S6K protein expression were observed to be upregulated by ulinastatin. In addition, cell vitality was found to increase and LDH was observed to decrease in the ulinastatin group compared with the HR group in vitro. Furthermore, rapamycin was found to attenuate the myocardial protective effect that is induced by ulinastatin. In vivo, ulinastatin was found to downregulate LC3‑Ⅱ protein expression, and reduce myocardium infarct size and LDH serum levels. These findings indicate that ulinastatin exhibits a myocardial protective effect against IR injury by regulating autophagy through mTOR activation.
authors.affiliation: Department of Cardiothoracic Surgery, Changzheng Hospital, The Second Military Medical University, Shanghai 200003, P.R. China.
authors.forename: Jian
authors.initials: J
authors.lastname: Xiao
authors.affiliation: Department of Physiology, The Second Military Medical University, Shanghai 200433, P.R. China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Department of Cardiothoracic Surgery, Changzheng Hospital, The Second Military Medical University, Shanghai 200003, P.R. China.
authors.forename: Guangyu
authors.initials: G
authors.lastname: Ji
authors.affiliation: Department of Cardiothoracic Surgery, Changzheng Hospital, The Second Military Medical University, Shanghai 200003, P.R. China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Yang
authors.affiliation: Department of Cardiothoracic Surgery, Changzheng Hospital, The Second Military Medical University, Shanghai 200003, P.R. China.
authors.forename: Bo
authors.initials: B
authors.lastname: Kang
authors.affiliation: Department of Cardiothoracic Surgery, Changzheng Hospital, The Second Military Medical University, Shanghai 200003, P.R. China.
authors.forename: Jianquan
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Department of Anesthesiology, Shanghai Chest Hospital Affiliated to Shanghai Jiaotong University, Shanghai 200030, P.R. China.
authors.forename: Feng
authors.initials: F
authors.lastname: Yao
authors.affiliation: Department of Cardiothoracic Surgery, Changzheng Hospital, The Second Military Medical University, Shanghai 200003, P.R. China.
authors.forename: Lihui
authors.initials: L
authors.lastname: Wu
authors.affiliation: Department of Physiology, The Second Military Medical University, Shanghai 200433, P.R. China.
authors.forename: Xin
authors.initials: X
authors.lastname: Ni
authors.affiliation: Department of Cardiothoracic Surgery, Changzheng Hospital, The Second Military Medical University, Shanghai 200003, P.R. China.
authors.forename: Zhinong
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000818:Animals; D001343:Autophagy / Q000187:drug effects*; D002478:Cells, Cultured; D004195:Disease Models, Animal; D015536:Down-Regulation / Q000187:drug effects; D006023:Glycoproteins / Q000494:pharmacology*; D008297:Male; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000166:cytology / Q000187:drug effects*; D010766:Phosphorylation / Q000187:drug effects; D020011:Protective Agents / Q000494:pharmacology*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000378:metabolism / Q000473:pathology; D038762:Ribosomal Protein S6 Kinases, 70-kDa / Q000378:metabolism; D020123:Sirolimus / Q000633:toxicity; D058570:TOR Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D006023:Glycoproteins; D008869:Microtubule-Associated Proteins; D020011:Protective Agents; D051057:Proto-Oncogene Proteins c-akt; D038762:Ribosomal Protein S6 Kinases, 70-kDa; D020123:Sirolimus; D058570:TOR Serine-Threonine Kinases; C526109:Anxa3 protein, rat; C028665:urinastatin