Upregulation of Long Noncoding RNA FGD5-AS1 Ameliorates Myocardial Ischemia/Reperfusion Injury via MicroRNA-106a-5p and MicroRNA-106b-5p.

ABSTRACT: Long noncoding RNAs have been known to play key roles in myocardial ischemia/reperfusion injury. This study was conducted to investigate whether upregulation of FGD5-AS1 can improve hypoxia/reoxygenation (H/R) injury of cardiomyocytes and its underlying mechanisms. Pc-FGD5-AS1 was used to overexpress FGD5-AS1 in cardiomyocytes. Cholecystokinin octapeptide and flow cytometry assays were performed to detect the effect of FGD5-AS1 on myocardial cell H/R injury. Quantitative real-time polymerase chain reaction and luciferase reporter assay were performed to assess the relationship between FGD5-AS1 and microRNA-106a-5p (miR-106a-5p) or miR-106b-5p. In patients with acute myocardial infarction and in H/R cardiomyocytes and ischemia/reperfusion myocardium, the expression levels of FGD5-AS1 were reduced, whereas the expression levels of miR-106a-5p and miR-106b-5p were increased. Overexpression of FGD5-AS1 increased the viability of H/R-treated cardiomyocytes and reduced the levels of apoptosis and creatine kinase-MB. In addition, FGD5-AS1 could bind to miR-106a-5p or miR-106b-5p and showed a mutual inhibitory effect between them. Furthermore, overexpression of miR-106a-5p or miR-106b-5p inhibited the expression of SMAD5. FGD5-AS1 upregulated the expression of SMAD5. In conclusion, FGD5-AS1 may be a potential therapeutic target for myocardial H/R injury, and its cardioprotective effect may be realized by reducing inflammatory response and cell apoptosis.

Increased Rho kinase activity in patients with heart ischemia/reperfusion.

BACKGROUND/AIM:\: Rho kinase is a downstream effector of Rho GTPase that is known to regulate various pathological processes. The aim of this study was to evaluate the regulation of Rho kinase activity in leukocytes in patients with ischemia/reperfusion (I/R) injury. PATIENTS AND METHODS: We investigated 38 patients with acute ST-segment elevation myocardial infarction (STEMI), 26 patients with atherosclerosis (AS) and 22 normal subjects. All patients underwent coronary angiography (CAG) and all STEMI patients received primary percutaneous coronary intervention (PPCI) of the left anterior descending artery (LAD) within 12 h after chest pain on-set. Blood samples for leukocyte Rho kinase activity were obtained before CAG and 3 and 24 hours after CAG/PCI. RESULTS: Rho kinase activity increased in the I/R and AS groups. Compared with the AS group, Rho kinase activity was significantly higher in peripheral blood leukocytes in STEMI/PPCI. Furthermore, there was no correlation between changes in Rho kinase activity and changes in high-sensitivity troponin I (hs-TnI) and C-reactive protein (CRP). There was a negative correlation between Rho kinase activity and IL-6. CONCLUSION: Rho kinase is involved in the pathogenesis of heart I/R injury in patients. Inhibition of Rho kinase may be an additional therapeutic intervention for the treatment of I/R.

Salvianolic acid B alleviates neurological injury by upregulating stanniocalcin 1 expression.

Background: Salvianolic acid B (Sal B) is a representative component of phenolic acids derived from the dried root and rhizome of Salvia miltiorrhiza Bge. (Labiatae), which promotes angiogenesis in myocardial infarction and diabetic cardiomyopathy. However, whether Sal B has a neuroprotective function in ischemic stroke by promoting angiogenesis is still unclear. Methods: In the present study, ischemic stroke models were induced in rats by middle cerebral artery occlusion (MCAO), and Sal B (10 or 20 mg/kg/d) was intraperitoneally injected according to a previous study. Neurological deficits were evaluated by the modified Longa five-point scale, modified Bederson scores and cerebral infarction sizes by triphenyltetrazolium chloride (TTC) staining. Apoptotic cells were tested by cleaved-caspase3 immunofluorescence staining and an in situ cell death (TUNEL) detection kit. Human umbilical vein endothelial cells (HUVECs) exposed to hypoxia were used to investigate the effects of Sal B on angiogenesis and tube formation in vitro. Results: Sal B ameliorated the neurological deficits, decreased the cerebral infarction volumes in rats with ischemic stroke, significantly increased the expression of vascular endothelial growth factor receptor 2 (VEGFR2) and VEGFA and promoted angiogenesis both in vivo and in vitro. Furthermore, Sal B increased stanniocalcin 1 (STC1) expression, induced the phosphorylation of protein kinase B (AKT) and mammalian target of rapamycin (mTOR) activity, enhanced cell migration, and activated VEGFR2/VEGFA signaling in endothelial cells. Conclusions: This study showed that Sal B promoted angiogenesis and alleviated neurological apoptosis in rats with ischemic stroke by promoting STC1.

MicroRNA-145-5p inhibits hypoxia/reoxygenation-induced apoptosis in H9c2 cardiomyocytes by targeting ROCK1.

There is increasing evidence that microRNAs (miRs) play critical roles in the pathological and physiological processes associated with myocardial ischemia reperfusion (I/R). miR-145 has been extensively studied in the cardiovascular system; however, the role of miR-145 in myocardial I/R remains unclear. Therefore, the present study aimed to investigate the role and mechanism of miR-145-5p in myocardial I/R by establishing a hypoxia/reoxygenation (H/R) model using H9c2 cardiomyocytes. The expression of miR-145-5p was regulated by transfection and the potential target of miR-145-5p was identified. In addition, apoptosis of the cardiomyocytes was evaluated using flow cytometry and the detection of cleaved caspase-3 by western blotting. The results revealed that miR-145-5p expression was decreased while cell apoptosis and Rho-associated coiled-coil-containing kinase 1 (ROCK1) expression were increased in H/R-stimulated H9c2 cardiomyocytes. The upregulation of miR-145-5p reduced apoptosis and the expression of ROCK1 in H/R-stimulated H9c2 cardiomyocytes. Furthermore, the overexpression of ROCK1 significantly attenuated the miR-145-5p-induced reduction of apoptosis following H/R. In conclusion, the present study indicates that the overexpression of miR-145-5p inhibits H/R-induced cardiomyocyte apoptosis by targeting ROCK1.

Inhibition of Rho-kinase is involved in the therapeutic effects of atorvastatin in heart ischemia/reperfusion.

The aim of the present study was to investigate the effects of atorvastatin against heart ischemia/reperfusion (I/R) injury and its potential underlying mechanism. Rats were allocated into the following groups: Sham, I/R, atorvastatin (10 mg/kg daily), fasudil (10 mg/kg daily) and atorvastatin + fasudil in combination. Drugs were administered for 2 weeks prior to I/R injury. I/R was established by ligating the left anterior descending branch (LAD) for 30 min and releasing the ligature for 180 min. The I/R group was found to have increased myocardial infarct size, cardiomyocyte apoptosis, levels of plasma interleukin (IL)-6 and tumor necrosis factor (TNF)-α, superoxide dismutase (SOD) activity, malondialdehyde (MDA) levels and Rho-kinase activity compared with the other treatment groups (P<0.05). Moreover, pretreatment with atorvastatin significantly attenuated Rho-kinase activity, myocardial infarct size, cardiomyocyte apoptosis, levels of plasma IL-6 and TNF-α, SOD activity and MDA levels, and upregulated nitric oxide production. It was also indicated that the specific Rho-kinase inhibitor, fasudil, had the same effects as atorvastatin in I/R. Therefore, the present results suggested atorvastatin may lead to cardiovascular protection, which may be mediated by Rho-kinase inhibition in heart I/R injury.

Serum cystatin C levels relate to no-reflow phenomenon in percutaneous coronary interventions in ST-segment elevation myocardial infarction.

BACKGROUND/AIM: No-reflow is a serious and frequent event during primary percutaneous coronary intervention (PPCI) for acute ST segment elevation myocardial infarction (STEMI). The aim of this study was to identify possible predictors for no-reflow. PATIENTS AND METHODS: We investigated 218 patients with acute anterior STEMI who underwent PPCI from December 2016 to December 2018. No-reflow was defined as a coronary TIMI flow grade of ≤ 2. TIMI flow grade 3 was defined as normal reflow. RESULTS: In our study, the no-reflow phenomenon was observed in 39 patients (18%) during angiography. The patients of no-reflow group were found to be more older, diabetics, longer pain-to-balloon time, lower blood pressure, higher platelet counts and higher levels of D-Dimer and Cystatin C (Cys-C). In multivariate logistic regression analysis, only diabetes (OR = 0.371, 95% CI: 0.157-0.872, P = 0.023), longer pain-to-balloon time (OR = 1.147, 95% CI: 1.015-1.297, P = 0.028) and higher Cys-C level (OR = 10.07, 95% CI: 2.340-43.377, P = 0.002) were predictors for no-reflow. CONCLUSION: Cys-C might be a useful predictor for the no-reflow phenomenon after PPCI in STEMI patients. It might help to screen STEMI patients with high risk of no-reflow on admission.

Enhancing autophagy protects platelets in immune thrombocytopenia patients.

BACKGROUND: Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder and involves increased apoptosis of platelets. Autophagy is an essential process for platelets to maintain their life and physiological functions. However, the role of autophagy in ITP platelets was previously unclear. METHODS: In the present study, the expression of autophagy-related protein and autophagy flux were detected in platelets from ITP patients and healthy controls by immunofluorescence staining and immunoblotting, and the influence of autophagy on the viability and apoptosis of ITP platelets was further explored. RESULTS: We found that platelet autophagy was diminished in ITP patients. Platelet autophagy in ITP was regulated by the PI3K/AKT/mTOR pathway, with mTOR (mammalian target of rapamycin) as a negative regulator and class III PtdIns3K playing a crucial role in the process. Importantly, the small-molecule compound ABO (6-amino-2,3-dihydro-3-hydroxymethyl-1,4-benzoxazine) enhanced autophagy in ITP platelets. Enhancing platelet autophagy alleviated platelet destruction by inhibiting apoptosis and improving platelet viability. CONCLUSIONS: These results suggest a role for autophagy regulation in the pathogenesis of ITP, and offer a novel treatment for these patients.

An explanation of the methanogenic pathway for methane production in anaerobic digestion of nitrogen-rich materials under mesophilic and thermophilic conditions.

The impact of temperature on the anaerobic digestion of chicken manure was investigated by studying the process performance and pathway for continuously-fed digesters under mesophilic and thermophilic conditions. The mesophilic digester obtained a 15% higher methane yield compared with the thermophilic digester. Mesophilic and thermophilic digester had free ammonia of 31 and 145 mg/L, respectively. The stable carbon isotope analysis indicated that 41% and 50% of acetate was converted to methane through the syntrophic acetate oxidation and hydrogenotrophic methanogenesis (SAO-HM) pathway under mesophilic and thermophilic conditions, respectively. The genus Pseudomonas represented 10% and 16% under mesophilic and thermophilic conditions, respectively. A high abundance of the methanogens genus Methanoculleus (94% of total methanogens) in mesophilic and the genus Methanothermobacter (96%) in thermophilic digesters indicated they were the main hydrogenotrophic partners in SAO. The present study therefore illustrated that methanogenic pathway shifting, induced by free ammonia, closely correlated to the process performance.

Darapladib, a Lipoprotein-Associated Phospholipase A2 Inhibitor, Reduces Rho Kinase Activity in Atherosclerosis.

PURPOSE: Increased lipoprotein-associated phospholipase A2 (Lp-PLA2) activity and Rho kinase activity may be associated with atherosclerosis. The principal aim of this study was to examine whether darapladib (a selective Lp-PLA2 inhibitor) could reduce the elevated Lp-PLA2 and Rho kinase activity in atherosclerosis. MATERIALS AND METHODS: Studies were performed in male Sprague-Dawley rats. The atherosclerosis rats were prepared by feeding them with a high-cholesterol diet for 10 weeks. Low-dose darapladib (25 mg·kg⁻¹·d⁻¹) and high-dose darapladib (50 mg·kg⁻¹·d⁻¹) interventions were then administered over the course of 2 weeks. RESULTS: The serum levels of triglycerides, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), high-sensitivity C-reactive protein (hs-CRP), and Lp-PLA2, significantly increased in atherosclerosis model groups, as did Rho kinase activity and cardiomyocyte apoptosis (p<0.05 vs. sham group), whereas nitric oxide (NO) production was reduced. Levels of TC, LDL-C, CRP, Lp-PLA2, and Rho kinase activity were respectively reduced in darapladib groups, whereas NO production was enhanced. When compared to the low-dose darapladib group, the reduction of the levels of TC, LDL-C, CRP, and Lp-PLA2 was more prominent in the high-dose darapladib group (p<0.05), and the increase of NO production was more prominent (p<0.05). Cardiomyocyte apoptosis of the high-dose darapladib group was also significantly reduced compared to the low-dose darapladib group (p<0.05). However, there was no significant difference in Rho kinase activity between the low-dose darapladib group and the high-dose darapladib group (p>0.05). CONCLUSION: Darapladib, a Lp-PLA2 inhibitor, leads to cardiovascular protection that might be mediated by its inhibition of both Rho kinase and Lp-PLA2 in atherosclerosis.

Atorvastatin up-regulates TRIB3 independent of ATF4-CHOP pathway in atherosclerotic patients.

BACKGROUND: Macrophage apoptosis triggered by endoplasmic reticulum (ER) stress contributes much to atherosclerosis, especially plaque vulnerability. Activating transcription factor 4 (ATF4)-CCAAT/enhancer binding protein (C/EBP) homologous protein (CHOP)-Tribbles 3 (TRIB3) pathway is closely related to the ER stress. This study aimed to investigate the effect of atorvastatin on the ATF4-CHOP-TRIB3 pathway. METHODS: Forty-seven patients were randomized into 80-mg and 20-mg atorvastatin group. Follow-up was performed at weeks 6 and 12, and complete blood chemistry, lipid assay and detection of 5 target genes (tumor protein 53, ATF4, C/EBP, CHOP and TRIB3) in monocytes/macrophages were conducted. Furthermore, the interaction between dosage and duration of therapy was evaluated. RESULTS: After 12-week therapy, patients in both groups experienced significant reductions in ATF4 (P=0.038) and C/EBP (P=0.003) expressions. Tumor protein 53 (P=0.015) and TRIB3 (P=0.045) expressions increased markedly in 80-mg atorvastatin group. However, there was no significant difference in CHOP expression at three time-points and between atorvastatin groups. Moreover, there was no interaction between dosage and duration of therapy. CONCLUSIONS: Atorvastatin has an effect on ER stress through ATF4-CHOP pathway. Atorvastatin at a high dose is more likely to increase TRIB3 expression, but this warrants further investigation.