Clinical value of BRE-AS1 in myocardial infarction and its role in myocardial infarction-induced cardiac muscle cell apoptosis.

Objectives. The aim of this study was to investigate the expression of long non-coding RNA (lncRNA) brain and reproductive organ-expressed protein (BRE) antisense RNA 1 (BRE-AS1) in patients with acute myocardial infarction (AMI) and its effect on ischemia/reperfusion (I/R)-induced oxidative stress and apoptosis of cardiomyocytes. Methods. Serum BRE-AS1 levels in patients with AMI was detected using quantitative real-time polymerase chain reaction (qRT-PCR). The diagnostic and prognostic values of BRE-AS1 were evaluated. H9c2 cells were treated with hypoxia/reoxygenation to establish an in vitro myocardial infarction cell model. The levels of inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and IL-6 were detected by enzyme-linked immunosorbent assay (ELISA). Levels of lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) were determined by commercial kits. Cell counting kit-8 (CCK-8) and flow cytometry were used to evaluate the cell viability and cell apoptosis. Results. The expression of BRE-AS1 in serum of patients with AMI is upregulated, which shows the clinical diagnostic value for AMI. In the I/R injury cell model, the knockout of BRE-AS1 can significantly alleviate the increase in TNF-α, IL-1ß, and IL-6 levels, inhibit the production of LDH and MDA, increase the activities of SOD and GSH-Px, promote the cell viability and suppress cell apoptosis. Conclusions. Abnormally elevated BRE-AS1 has a high diagnostic value for AMI as well as a prognostic value for major adverse cardiovascular events (MACEs). The elevation of BRE-AS1 promoted oxidative stress injury and cell apoptosis in vitro.

MiR-483-5p downregulation alleviates ox-LDL induced endothelial cell injury in atherosclerosis.

BACKGROUND: In light of the abnormal expression of microRNA (miR-483-5p) in patients with atherosclerosis (AS), its role in vascular endothelial cell injury was explored. And the mechanisms related to autophagy were also elucidated. METHODS: Human umbilical vein endothelial cells (HUVECs) were given 100 mg/L ox-LDL to induce endothelial injury. Cell transfection was done to regulate miR-483-5p levels. Cell viability and apoptosis were detected. qRT-PCR was employed for the mRNA levels' detection. RESULTS: Autophagic flux impairment of HUVECs was detected after ox-LDL treatment, along with the upregulation of miR-483-5p. Ox-LDL inhibited cell viability and promoted cell apoptosis, but these influences were changed by miR-483-5p downregulation. MiR-483-5p downregulation decreased the mRNA levels of IL-1ß, IL-6, ICAM-1 and VCAM-1. 3-MA, the autophagy inhibitor, reversed the beneficial role of miR-483-5p downregulation in ox-LDL-induced HUVECs' injury. TIMP2 acts as a target gene of miR-483-5p, and was downregulated in HUVEC models. CONCLUSION: MiR-483-5p downregulation alleviated ox-LDL-induced endothelial injury via activating autophagy, this might be related to TIMP2.

MicroRNA-218-5p regulates inflammation response via targeting TLR4 in atherosclerosis.

BACKGROUND: To investigate the expression of miR-218-5p in atherosclerosis patients and its effect on ox-LDL induced THP-1-derived macrophage inflammatory response. METHODS: RT-qPCR detected the expression of serum miR-218-5p, and the diagnostic value of miR-218-5p was analyzed by ROC curve. Pearson correlation coefficient was used to evaluate the correlation between miR-218-5p and CIMT and CRP. THP-1 cells were treated with ox-LDL to construct foam cell model. The expression of miR-218-5p was regulated by in vitro transfection technique, and the effects of miR-218-5p on cell viability, apoptosis and inflammation were investigated. Luciferase reporter genes were used to analyze target genes of miR-218-5p in cell models. RESULTS: The expression of miR-218-5p in the atherosclerosis cohort was significantly reduced, and miR-218-5p showed a good ability to distinguish patients from healthy people. Correlation analysis showed that the level of miR-218-5p was negatively correlated with the levels of CIMT and CRP. Cytological studies showed that the expression of miR-218-5p in macrophages decreased after ox-LDL induction. ox-LDL treatment on macrophages resulted in decreased cell viability, increased cell apoptosis and production of inflammatory cytokines, which contributed to the exacerbation of plaque formation. However, the above situation was reversed after upregulation of miR-218-5p. Bioinformatics analysis showed that TLR4 may be the target gene of miR-218-5p, and this hypothesis was proved by luciferase reporter gene assay. CONCLUSIONS: The expression of miR-218-5p is reduced in atherosclerosis, and it may regulate the inflammatory response of atherosclerotic foam cells by targeting TLR4, suggesting that miR-218-5p may be a promising target for clinical atherosclerosis therapy.

LncRNA LSINCT5/miR-222 regulates myocardial ischemia­reperfusion injury through PI3K/AKT pathway.

Cardiovascular diseases rank the top cause of morbidity and mortality worldwide and are usually associated with blood reperfusion after myocardial ischemia/reperfusion injury (MIRI), which often causes severe pathological damages and cardiomyocyte apoptosis. LSINCT5 expression in the plasma of MI patients (n = 53), healthy controls (n = 42) and hypoxia-reoxygenation (HR)-treated cardiomyocyte AC16 cells was examined using qRT-PCR. The effects of LSINCT5 on cell viability and apoptosis were detected by MTT and flow cytometry, respectively. The expression of apoptosis-related proteins Bcl2, Bax and caspase 3 were tested by Western blot. The interaction between LSINCT5 and miR-222 was predicted by bioinformatic analysis. Moreover, changes in viability and apoptosis of AC16 cells co-transfected with siLSINCT5 and miR-222 inhibitor after HR treatment were examined. At last, the expression of proteins in PI3K/AKT pathway, namely PTEN, PI3K and AKT, was examined to analyze the possible pathway participating in LSINCT5-mediated MI/RI. Our study showed that LSINCT5 expression was upregulated in the plasma of MI patients and HR-treated AC16 cells. LSINCT5 overexpression significantly decreased cell viability and apoptosis. Luciferase reporter gene assay and RNA pulldown assay showed that LSINCT5 was a molecular sponge of miR-222. MiR-222 silencing in AC16 cells simulated the phenotypes of MIRI patients and HR-treated cells, indicating that LSINCT5 functions via miR-222 to regulate proliferation and apoptosis of HR-treated AC16 cells. We also showed that proteins of PI3K/AKT signaling pathway were affected in HR-treated AC16 cells, and LSINTC5 knockdown rescued these effects. LncRNA LSINCT5 was upregulated during MI pathogenesis, and LSINCT5 regulated MIRI possibly via a potential LSINCT5/miR-222 axis and PI3K/AKT signaling pathway. Our findings may provide novel evidence for MIRI prevention.

A novel squaramide compound alleviates cognitive deficits through activation of Akt and Erk1/2 in a rat model of vascular dementia.

Vascular dementia is the second most common type of dementia, yet no effective treatment for it exists. Akt and Erk1/2 signaling pathways are involved in neuronal survival. It has been reported that bisperoxovanadium (pyridin-2-squaramide), a novel squaramide compound, protects against cerebral ischemia injury via activation of Akt and Erk1/2. Here, the potential neuroprotective effect of bisperoxovanadium is shown for the first time in a model of vascular dementia induced in 6-month-old male Sprague-Dawley rats by two-vessel occlusion injury applied to 6-month-old. Following this lesion, bisperoxovanadium (pyridin-2-squaramide) (1 mg/kg/day) was intragastrically administered for four successive weeks. The Morris water maze test estimated cognitive function. The morphological examination was performed by hematoxylin-eosin staining. Akt and Erk1/2 protein abundance were assessed by Western blot. Results showed that bisperoxovanadium (pyridin-2-squaramide) attenuated not only cognitive dysfunction but also alleviated histopathological changes in rats with vascular dementia. Moreover, bisperoxovanadium (pyridin-2-squaramide) ultimately reduced neuronal apoptosis represented by the Bax/Bcl-2 ratio in the CA1 (cornu ammonis 1) region of the hippocampus. Importantly, the levels of p-Akt(ser473) and p-Erk1/2(Thr202/Tyr204>) were increased after treatment with bisperoxovanadium (pyridin-2-squaramide). It is concluded that the novel squaramide compound bisperoxovanadium (pyridin-2-squaramide) might be effective in the treatment of vascular dementia by activation of Akt and Erk1/2.