Methamphetamine induces autophagy in myocardial cells

Objective To investigate the process of autophagy in myocardial cells induced by methamphetamine (METH). Methods In vivo study: sixty 6-week-old male C57Bl/6 J mice were randomly(random number) divided into three groups evenly, control group, three-day METH treated group and seven-day METH treated group. Mice in control group was given physiological saline through intraperitoneal injection 2 times per day and lasted 7 days. Mice in three days group and seven days group intake methamphetamine at a dose of 15 mg/kg every time through intraperitoneal injection 2 times a day, lasted 3 days and 7 days respectively. The hearts of the mice were then obtained by anatomical method 24 hours after the last intraperitoneal injection of METH, then autophagy related proteins were detected by western blotting. In vitro study: the model was established by H9C2 cells. The cells were divided into two groups, control group (cells were cultured by normal medium) and METH group (cells were cultured by medium includes 900 mmol/mL METH for 24 hours). The expressions change of autophagy related proteins in cells were tested by Western blotting. Additionally, LC3-Ⅱ was tagged by red fluorescent and then the stained cells were visualized under a Zeiss LSM710 confocal microscope. Furthermore, the numbers of autophagosomes in cells were visualized by transmission electron microscopy. Results The expression of p62,Beclin-1and LC3 were significantly increased in METH group when compared with control group (P<0.05). The level of LC3 was significantly increased in METH treated group compared with control group visualized under a Zeiss LSM710 confocal microscope. The numbers of autophagosomes in METH group are more than control group visualized by transmission electron microscopy. Conclusions Autophagy can be induced by METH in myocardial cells. Key words: Methamphetamine (METH); autophagy; mice (C57Bl/6J); H9C2 cell line