ABSTRACT
Ischemia-reperfusion (IR) injury is a major cause of clinical emergencies during and after surgical procedures.Propofol protects the heart from cardiovascular IR injury by inhibiting autophagy. MicroRNAs (miRNAs)participate in anesthetic-regulated cardiovascular injury. MiR-20b-5p targets unc-51-like autophagy activatingkinase 1 (ULK1). Its role in propofol-modulated cardiovascular IR injury remains unclear, however. In thisstudy, we used an in vitro model of hypoxia-reoxygenation (HR)-induced injury to human umbilical veinendothelial cells (HUVECs) to determine the protective effect of miR-20b-5p in cells preconditioned withpropofol. We found that miR-20b-5p was significantly higher and ULK1 was lower in propofol-preconditionedHUVECs with HR injury than in HUVECs with HR injury only. Additionally, miR-20b-5p overexpressionincreased cell viability and repressed autophagy and apoptosis more in propofol-preconditioned HUVECs withHR injury than in HUVECs with HR injury only. A luciferase reporter assay confirmed the target reactionbetween miR-20b-5p and ULK1. Overexpression of ULK1 restrained the protective effect of miR-20b-5p inpropofol-preconditioned HUVECs with HR injury. In conclusion, our results indicate that propofol inhibitsautophagic cell death via the miR-20b-5p-ULKI axis and that ULK1 may be a therapeutic target for cardiovascular IR injury
ABSTRACT
OBJECTIVE: To explore the effect of electroacupuncture (EA) at "Zusanli" (ST36) on gastrointestinal motility and expression of autophagy marker LC3 and autophagy signaling pathway molecule AMP-activated protein kinase (AMPK) in rats with functional dyspepsia (FD), so as to explore its mechanisms underlying improvement of FD. METHODS: A total of 40 male SD rats were randomly divided into blank control, model, EA, AMPK inhibitor and EA＋AMPK inhibitor groups, with 8 rats in each group. The FD model was established by tail-clip (30 min/time, twice daily) ＋ single day feeding, and gavage of normal saline (2 mL/time, twice a day) for 2 successive weeks. For rats of EA and EA＋AMPK inhibitor groups, EA (4 Hz, 1.0 mA) was applied to bilateral ST36 for 20 min, once daily for 7 successive days. For rats of the AMPK-inhibitor and EA＋AMPK inhibitor groups, Compound C (20 mg/kg) solution was administered by intraperitoneal injection before every EA administration. The gastric residual rate and small intestinal transit rate were calculated based on the weight of stomach and length of ink propelling and total small intestine, respectively. The expression levels of c-kit, microtubule-associated protein 1 light chain 3, Beclin 1, phosphorylated (p)-AMPK and p-unc-51 like autophagy activating kinase 1(ULK1) in the gastric antrum tissue were detected by using Western blot. RESULTS: Compared with the blank control group, the gastric residual rate and the expression levels of LC3-Ⅱ/LC3Ⅰ， Beclin 1, p-AMPK and p-ULK1 proteins were significantly increased, and the small intestinal transit rate and the expression of c-kit protein obviously decreased in the model group (P0.05). CONCLUSION: EA at ST36 can promote gastrointestinal motility in FD rats, which is possibly mediated by inhibiting excessive autophagy of interstitial cells of Cajal via down-regulating AMPK/ULK1 signaling.
ABSTRACT
Objective To explore the changes of Beclin-1,P62/SQSTM1,microtubule-associated protein 1 light chain 3 (LC3)and unc-51 like autophagy activating kinase 1 (ULK-1)in the brains of the rats in the deve-lopmental stage with epilepsy. Methods Seventy-two male Sprague Dawley (SD)rats aged 21 days were randomly divided into the control group and the epilepsy group. The rats in 2 groups were randomly subdivided into 4 groups according to the time intervals (3 h,6 h,12 h and 48 h),respectively,with 9 rats in each group. The rats in the epilep-sy group were injected with kainic acid (12 mg/kg)to induce epilepsy,and the rats in the control group were injected with equal volume of saline. The rats in 2 groups were anaesthetized and sacrificed. Then,the brain tissues of the rats were quickly removed according to the time intervals. The brain damages were determined by adopting Nissl staining method. The apoptotic cells were detected by Terminal - deoxynucleoitidyl transferase mediated nick end labeling (TUNEL)assays. The expressions of Beclin-1,P62/SQSTM1,LC3 and ULK-1 mRNA levels in cortex were mea-sured by using real-time quantitative polymerase chain reaction (qPCR)analysis. Results Nissl staining indicated that many neurons were damaged performing vague outline,irregularly aligned,pyknotic nuclei and shrunken somata in the epilepsy 48 h group. In addition,there was a huge loss of neurons in cortex in the epilepsy 48 h group [(82 ± 8)num-bers],compared with the control group [(122 ± 8)numbers],and the difference was statistically significant (F＝3. 768, P＝0. 01). The apoptotic cells tremendously increased in the epilepsy 48 h group [(13 ± 7)numbers],compared with the control group [(2 ± 1)numbers]by TUNEL analysis,and the diffe-rence was statistically significant (t＝ -3. 821, P＝0. 003). qPCR showed the mRNA levels of Beclin-1,P62/SQSTM1,LC3 and ULK-1 were upregulated in the epi-lepsy 12 h group (1. 70 ± 0. 75,1. 75 ± 0. 77,1. 52 ± 0. 43,7. 48 ± 6. 12)and the epilepsy 48 h group (1. 63 ± 0. 43, 1. 48 ± 0. 74,1. 74 ± 0. 55,7. 69 ± 5. 65),compared with the control group (1. 00,1. 00,1. 00,1. 00),and the differences were statistically significant (F＝2. 820,3. 452,5. 811,5. 002,all P＜0. 05). Conclusion The autophagy activates be-fore apoptosis occurs,and autophagy-related genes probably are involved in epilepsy-induced brain damage.