MiR-181a affects myocardial ischemia-reperfusion injury in rats via regulating akt signaling pathway

OBJECTIVE

The aim of this study was to explore the influence of the micro ribonucleic acid (miR)-181a on myocardial ischemia-reperfusion injury (MIRI) in rats by regulating the protein kinase B (Akt) signaling pathway.

MATERIALS AND METHODS

A total of 30 male Sprague-Dawley rats were randomly divided into three groups, including: sham operation group (Sham group), ischemia-reperfusion group (I/R group), and miR group (MiR-181a group). The model of myocardial ischemia-reperfusion was successfully established in rats. The concentration of blood nitric oxide (NO) was detected by the relative kits. Myocardial apoptosis in rats of the three groups was detected using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. Furthermore, the expressions of myocardial cell apoptosis-related proteins and tumor necrosis factor-α (TNF-α), and the degree of Akt phosphorylation were determined by Western blotting.

RESULTS

Compared with Sham group and miR-181a group, I/R group exhibited significantly elevated left ventricular end-diastolic pressure (LVEDP) (p<0.05). However, the left ventricular end-systolic pressure (LVESP), stroke work (SW), differential pressure (DP), end-systolic pressure-volume relationship (ESPVR), and end-diastolic pressure-volume relationship (EDPVR) significantly decreased in the I/R group (p<0.05). In comparison with miR-181a group, the apoptosis index of myocardial cells was remarkably elevated in the I/R group, showing statistically significant differences (p<0.05). The protein bands were analyzed using the Quantity One detection software. The results demonstrated that, compared with the Sham group, I/R group showed significantly elevated expressions of cysteine-aspartic protease (Caspase)-3 and TNF-α in rat myocardial tissues (p<0.05). However, the protein levels of Akt and endothelial NO synthase (eNOS) phosphorylation and NO in rat myocardial cells were significantly down-regulated (p<0.05).

CONCLUSIONS

MiR-181a activates Akt to promote the phosphorylation of its downstream protein eNOS, inhibit the apoptosis of myocardial cells, and alleviate MIRI.

Role and mechanism of microRNA-548c-3p/c-Myb in myocardial infarction fibrosis in rats

OBJECTIVE

To investigate the role of micro ribonucleic acid (miR)-548c-3p in myocardial fibrosis after myocardial infarction (MI), and to explore the possible underlying.

MATERIALS AND METHODS

The rat model of MI was successfully established in-vivo. MiR-548c-3p was upregulated via lentivirus transfection with miR-548c-3p mimics. Cardiac function of rats was detected via echocardiography. Meanwhile, Sirius red and Masson staining were used to detect the level of fibrosis index in MI model. Subsequently, myocardial fibroblasts were isolated and cultured in vitro. An oxygen-glucose deprivation (OGD) model was established to mimicking the ischemic condition. Furthermore, the relationship between miR-548c-3p and c-Myb was verified, and the levels of fibrosis-related factors (including α-SMA and COL1A1) were measured.

RESULTS

In-vivo experiments showed that miR-548c-3p expression in rats was significantly down-regulated at 2 and 4 weeks after MI. Up-regulation of miR-548c-3p significantly improved cardiac function, reduced myocardial fibrosis and inhibited the protein expression of proto-oncogene c-Myb (c-Myb). In vitro experiments revealed that c-Myb was a target gene of miR-548c-3p. In addition, miR-548c-3p could inhibit the expressions of α-SMA and COL1A1 through targeting c-Myb.

CONCLUSIONS

MiR-548c-3p could improve myocardial fibrosis by targeting c-Myb.

Angiopoietin-like protein 3 markedly enhanced in the hyperlipidemia related proteinuria

BACKGROUND

Angiopoietin-like protein 3(ANGPTL3) is well acknowledged as a key regulator of lipid metabolism. Now, there have not been enough data to explain the mechanism of hyperlipidemia related proteinuria. In this study, we hoped to investigate the changes of Angiopoietin-like protein 3(ANGPTL3) levels in hyperlipidemia patients with different proteinuria levels.

METHODS

Seventy-one patients with hyperlipidemia were selected, who were hospitalized in Gansu Provincial People's Hospital from September 2016 to September 2017, and 20 healthy people in the physical examination center were selected. We combed through medical history and conducted clinical biochemical indicators of blood urea nitrogen (BUN), serum creatinine (SCr), 24 h urine protein quantitation (24hUPro), cholesterol (TC), triglyceride (TG), high density lipoprotein (HDL) and low detection of density lipoproteins (LDL-C). The concentration of serum ANGPTL3 was measured by ELISA.

RESULTS

1. Serum ANGPTL3 in patients with hyperlipidemia related proteinuria was higher than that in the control group, and the difference was statistically significant (p < 0.05); 2. 24hUPro and BMI (r = 0.321, P = 0.002), TC (r = 0.465, P = 0.000), TG (r = 0.281, P = 0.007), LDL (r = 0.478, P = 0.000) in patients with hyperlipidemia related proteinuria are positively correlated, suggesting that dyslipidemia is related to the occurrence of proteinuria; 3. BMI, TC, TG and LDL in patients with hyperlipidemia related proteinuria were positively correlated with serum ANGPTL3. 4. The 24hUPro of patients with hyperlipidemia related proteinuria was positively correlated with serum ANGPTL3 levels, and BUN and SCr were not associated with serum ANGPTL3 level. 5. There was no significant difference in TC, TG, BMI, 24hUPro and serum ANGPTL3 between the statin-treated and the untreated groups in patients with hyperlipidemia related proteinuria.

CONCLUSIONS

Angiopoietin-like protein 3 markedly enhanced in the hyperlipidemia related proteinuria.

A baculovirus vector derived from immediately early gene promoter of Autographa californica nuclear polyhedrosis virus

A transfer vector was constructed in which the neomycin resistance (neo) gene was under the control of a copy of Autographa californica nuclear polyhedrosis virus (AcMNPV) IE1 gene promoter at the p10 locus. After cotransfection of Spodoptera frugiperda (Sf9) cells with the transfer vector and infectious AcMNPV DNA, the recombinant virus-containing neo gene was selected by serial passage of the mixed progenies from cotransfection. This was done at low MOI in the presence of G418 in growth medium and was followed by limited dilution. RNA dot hybridization showed that the neo gene was transcribed from immediately early phase to very late phase, in infected Sf9 cells. These results demonstrate that a new baculovirus vector system had been constructed in infected cells. Furthermore, a new method for selection of positive recombinant baculovirus had been developed.