ABSTRACT
Objective To study the expression of the three autophagy-associated proteins, BECN1, LC3 and p62, after the injury of the skeletal muscle of rats and to explore its application in differentiation between antemortem and postmortem injury. Methods The 72 healthy Sprague-Dawley rats were randomly divided into the undamaged control group, the antemortem injury group （0.5 h, 1 h, 2 h, 4 h, 8 h, 16 h and 24 h） and postmortem injury group （0.5 h, 1 h, 2 h and 4 h）. A model of the injured right hind limb of rats was constructed. The expressions of the autophagy-associated proteins, BECN1, LC3-2/LC3-1 and p62, in the control group, the antemortem injury group and postmortem injury group were detected by Western blotting method. The data were respectively centralized and standardized and the orthogonal partial least square-discrimination analysis （OPLS-DA） identification model of antemortem and postmortem injury groups was constructed. Results The expression of BECN1, p62 protein and LC3-2/LC3-1 after the injury of the skeletal muscle of the rats showed different degrees of changes, but the differences among the 3 groups had no statistical significance. Antemortem and postmortem injury groups can be distinguished by centralizing and standardizing the expression levels of autophagy protein BECN1 and the ratio of LC3-2/LC3-1. The principal components extracted from OPLS-DA model of antemortem injury and postmortem injury had a relatively good interpretation of the model （Rx2=0.563, Ry2=0.439）, but it were less predictive （Q2=0.366）. Conclusion The expression of BECN1 and the ratio of LC3-2/LC3-1 in injured local tissue of the rat skeletal muscle can be used for the differentiation of antemortem injury group and postmortem injury group.
Subject(s)
Animals , Rats , Autophagy , Muscle, Skeletal , Postmortem Changes , Proteins/metabolism , Rats, Sprague-DawleyABSTRACT
OBJECTIVE: To observe the effect of moxibustion (Moxi) preconditioning with seed-sized moxa cones on myocardial ischemia-reperfusion injury (MI/RI) at different stages, and to analyze the correlation between this effect and the expression of autophagy related protein Beclin 1. METHODS: This study contains two parts: 1) changes of myocardial pathological injury and percentages of myocardial infarcted area at different time-points after modeling and Moxi intervention, and 2) effect of Moxi on contents of serum cardiac troponin T(cTnT) and expression of myocardial Bcl-2, Bax and Beclin 1 proteins. In the first part, 42 SD rats were randomly divided into model group, 1 day (d) Moxi group, 2 d Moxi group, 3 d Moxi group，4 d Moxi group, 5 d Moxi group and 7 d Moxi group. The model of MI/RI was established by ligating the left anterior descending coronary artery (LAD) for 30 min and reperfusion for 240 min. The electrocardiogram (ECG) of standard limb lead Ⅱ was monitored and the heart was taken 4 h after reperfusion for examining myocardial infarcted size with triphenyl tetrazolium chloride (TTC) staining. In the second part, 48 SD rats were randomized into sham-operation, model, moxibustion and autophagy inhibitor (3-MA) groups, with 12 rats in each group. The serum cTnT level was assayed and histopathological changes of the myocardial tissue below the ligation site were examined with HE staining, and the expression levels of Bcl-2, Bax and Beclin 1 proteins in the myocardial tissue below the LAD-ligated site were detected using Western blot. RESULTS: Compared with the model group, the percentages of myocardial infarcted area were significantly decreased in the 4 d, 5 d and 7 d Moxi groups (P0.05). The state of MI-induced breakage and disordered arrangement of myocardial fibers with interstitial edema and inflammatory cell infiltration at the MI stage in the Moxi group and at the reperfusion stage in the autophagy inhibitor group was relatively lighter. The levels of serum cTnT content and Bax/Bcl-2 and Beclin 1 protein expression at the MI and reperfusion stages were significantly higher in the model group than in the sham-operation group (P<0.01), and considerably lower in the Moxi and autophagy groups than in the model group (P<0.01). The serum cTnT content, ratio of Bax/Bcl-2 expression and Beclin 1 expression levels at the MI and reperfusion stages were significantly lower in the autophagy inhibitor group than in the Moxi group (P<0.05). CONCLUSIONS: Moxibustion with seed-sized moxa cones at "Neiguan" (PC 6) can effectively alleviate myocardial ischemia in MI/RI rats, which is probably related to its effect in down-regulating Bax/Bcl-2 and Beclin 1 expression and in inhibiting autophagy.
ABSTRACT
OBJECTIVE:To study the effects of Shenfu qiangxin(SFQX)pills on the expression of autophagy-associated pro-tein LC3b and pro apoptotic gene Bax in myocardial cells of rats with cardiorenal syndrome (CRS). METHODS:Rats were ran-domly divided into sham operation group(water),model group(water),positive control group(Captopril tablets 2.3 mg/kg)and SFQX pills high-dose,medium-dose and low-dose groups [13.2,6.6,3.3 g(crude drug)/kg],with 10 rats in each group. CRS mod-el was induced in those groups by abdominal-aortae-constriction+acute renal ischemia reperfusion injury except for sham operation group;and they were given relevant medicine intragastrically 8 week after operation,once a day,for consecutive 4 weeks. Plasma contents of Cr and ALD,the protein expression of LC3b and Bax in myocardial tissue of rats were detected 24 h after last medica-tion;ventricular index was calculated,and morphological change of myocardial tissue was observed. RESULTS:Compared with sham operation group,the plasma contents of Cr and ALD,ventricular index and the protein expression of LC3b in myocardial tis-sue increased significantly in model group (P<0.05 or P<0.01);and myocardial cell suffered from endochylema red deletion, myocardial cross striation disorder,intercellular space fibrosis aggravation and so on. Compared with model group,the plasma con-tents of Cr and ALD(except for positive control group)and the protein expression of LC3b and Bax in myocardial tissue decreased significantly in positive control group and SFQX pills high-dose group(P<0.05 or P<0.01);myocardial pathological change was improved;the ventricular index decreased significantly in SFQX pills low-dose and medium-dose groups (P<0.05). CONCLU-SIONS:SFQX pills can decrease the plasma contents of Cr and ALD,inhibit myocardial cell autophagy and apoptosis in CRS rats.