ABSTRACT
Diabetic cardiomyopathy (DCM) is caused by diabetes and can result in heart failure. Long noncoding RNAs (lncRNAs) have been demonstrated to be closely associated with DCM development. The present study aimed to investigate whether lncRNAmetastasisassociated lung adenocarcinoma transcript1 (MALAT1) altered high glucose (HG)induced H9C2 cardiomyocyte pyroptosis by targeting microRNA (miR)1413p. H9C2 cells were treated with normal glucose (NG) or HG. lncRNAMALAT1 and miR1413p expression levels were determined via reverse transcriptionquantitative PCR (RTqPCR). MALAT1 and miR1413p knockdown and overexpression were established and confirmed via RTqPCR. The association between MALAT1 expression and miR1413p expression, as well as the induction of pyroptosis and gasdermin D (GSDMD)N expression were evaluated by performing dual luciferase reporter, TUNEL staining and immunofluorescence staining assays, respectively. Western blotting was conducted to measure the expression levels of pyroptosisassociated proteins, including apoptosisassociated specklike protein, GSDMDN, caspase1, nucleotide oligomerization domainlike receptor protein 3 and GSDMD. MALAT1 mRNA expression levels were significantly increased, whereas miR1413p expression levels were significantly decreased in HGtreated H9C2 cells compared with the NG group. Compared with the HG group, MALAT1 overexpression significantly reduced miR1413p expression levels, increased the rate of TUNEL positive cells and upregulated the expression levels of pyroptosisassociated proteins. MALAT1 knockdown displayed the opposite effect on the rate of TUNEL positive cells and the expression levels of pyroptosisassociated proteins. Furthermore, the rate of TUNEL positive cells, and GSDMDN and pyroptosisassociated protein expression levels were significantly reduced by miR1413p overexpression in MALAT1overexpression H9C2 cells. The results indicated that compared with NG treatment, HG treatment increased MALAT1 expression levels and decreased miR1413p expression levels in H9C2 cells. Therefore, the present study suggested that lncRNAMALAT1 targeted miR1413p to promote HGinduced H9C2 cardiomyocyte pyroptosis.
Subject(s)
Gene Expression Regulation , Glucose/pharmacology , MicroRNAs/genetics , Myocytes, Cardiac/drug effects , Pyroptosis/drug effects , RNA, Long Noncoding/genetics , Animals , Caspase 1/genetics , Caspase 1/metabolism , Cell Line , Dose-Response Relationship, Drug , Down-Regulation , Glucose/metabolism , Intracellular Signaling Peptides and Proteins/genetics , Intracellular Signaling Peptides and Proteins/metabolism , Myocytes, Cardiac/cytology , Myocytes, Cardiac/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Phosphate-Binding Proteins/genetics , Phosphate-Binding Proteins/metabolism , Pyroptosis/genetics , RatsABSTRACT
OBJECTIVE: To evaluate Candesartan therapeutic effect against atherosclerotic plaque rupture and to explore the related mechanisms. METHODS: Thirty-four New Zealand White male rabbits were randomly divided into three groups: the control group, the model control group and the Candesartan intervention group. The control group rabbits were fed with a normal diet. Rabbits of the latter two groups were fed with a 1% high-cholesterol diet and received a balloon catheter injury respectively one week after the cholesterol feeding. Candesartan (0.5 mgâ±kg⻹â±d⻹) was given to the Candesartan group rabbits 2 days before the performance of the balloon catheter injury. By the end of 12(th) week of the experiment, Russell's viper venom was used for rabbits of both the model control and the Candesartan groups in order to induce rupture of the plaques developed and followed by sacrifice of all the rabbits of the 3 groups. The aortas were removed and fixed for histological evaluation. Immunohistochemistry of MMP-9, macrophage markers and collagen were performed. The protein expression of MMP-9 was determined using Western blot analysis. RESULTS: In the model control group, 7 of 9 rabbits with a total of 12 plaques developed rupture and thrombosis of the plaques after the induction. In contrast, only 2 of 10 rabbits with a total of 3 plaques demonstrated rupture and thrombosis in the Candesartan group (P < 0.05). The control group rabbits did not have plaque rupture and thrombosis. Compared with the model group, both the percentage area of MMP-9 and macrophages in the plaques were significantly decreased in the Candesartan group (12.35% ± 4.28% vs 32.58% ± 9.16%, P < 0.05; 13.87% ± 4.91% vs 23.8% ± 7.45%, P < 0.05). There was an increased percentage of collagen content in total plaques of the Candesartan group (30.27% ± 11.36% vs 4.18% ± 1.28%, P < 0.01). Compared with the model group, the protein expression of MMP-9 was significantly decreased in the Candesartan group (P < 0.01). CONCLUSION: Candesartan has a preventive value against atherosclerotic plaque rupture in hypercholesterolemic rabbits, likely through its reduction of MMP-9 expression, inhibition of macrophage accumulation and increase of collagen content within the plaques.