Human Circulating MicroRNA-1 and MicroRNA-126 as Potential Novel Indicators for Acute Myocardial Infarction

Circulating miRNAs have been shown as promising biomarkers for various pathologic conditions. The aim of this study was to clarify that circulating miR-1 and miR-126 in human plasma might be useful as biomarkers in acute myocardial infarction (AMI). In our study, after pre-test, two candidate miRNAs were detected by using real-time RT-PCR. Cardiac troponin I (cTnI) concentrations were measured by ELISA assay in plasma from patients with AMI (n=17) and healthy subjects (n=25), simultaneously. Increased miR-1 and decreased miR-126 in plasma from patients with AMI after the onset of symptoms compared with healthy subjects were found. A remarkable finding in this study is that miR-1, miR-126 and cTnI expression levels exhibited the same trend. Our results suggest that the plasma concentrations of miR-1 and miR-126 may be useful indicators for AMI

β-AR Blockers Suppresses ER Stress in Cardiac Hypertrophy and Heart Failure

Long-term β-adrenergic receptor (β-AR) blockade reduces mortality in patients with heart failure. Chronic sympathetic hyperactivity in heart failure causes sustained β-AR activation, and this can deplete Ca(2+) in endoplasmic reticulum (ER) leading to ER stress and subsequent apoptosis. We tested the effect of β-AR blockers on ER stress pathway in experimental model of heart failure.ER chaperones were markedly increased in failing hearts of patients with end-stage heart failure. In Sprague-Dawley rats, cardiac hypertrophy and heart failure was induced by abdominal aortic constriction or isoproterenol subcutaneous injection. Oral β-AR blockers treatment was performed in therapy groups. Cardiac remodeling and left ventricular function were analyzed in rats failing hearts. After 4 or 8 weeks of banding, rats developed cardiac hypertrophy and failure. Cardiac expression of ER chaperones was significantly increased. Similar to the findings above, sustained isoproterenol infusion for 2 weeks induced cardiac hypertrophy and failure with increased ER chaperones and apoptosis in hearts. β-AR blockers treatment markedly attenuated these pathological changes and reduced ER stress and apoptosis in failing hearts. On the other hand, β-AR agonist isoproterenol induced ER stress and apoptosis in cultured cardiomyocytes. β-AR blockers largely prevented ER stress and protected myocytes against apoptosis. And β-AR blockade significantly suppressed the overactivation of CaMKII in isoproterenol-stimulated cardiomyocytes and failing hearts in rats.Our results demonstrated that ER stress occurred in failing hearts and this could be reversed by β-AR blockade. Alleviation of ER stress may be an important mechanism underlying the therapeutic effect of β-AR blockers on heart failure

ER Stress Negatively Modulates the Expression of the miR-199a/214 Cluster to Regulates Tumor Survival and Progression in Human Hepatocellular Cancer

Background: Recent studies have emphasized causative links between microRNAs (miRNAs) deregulation and tumor development. In hepatocellular carcinoma (HCC), more and more miRNAs were identified as diagnostic and prognostic cancer biomarkers, as well as additional therapeutic tools. This study aimed to investigate the functional significance and regulatory mechanism of the miR-199a2/214 cluster in HCC progression. Methods and Findings: In this study, we showed that miR-214, as well as miR-199a-3p and miR-199a-5p levels were significantly reduced in the majority of examined 23 HCC tissues and HepG2 and SMMC-7721 cell lines, compared with their nontumor counterparts. To further explore the role of miR-214 in hepatocarcinogenesis, we disclosed that the ER stressinduced pro-survival factor XBP-1 is a target of miR-214 by using western blot assay and luciferase reporter assay. Reexpression of miR-214 in HCC cell lines (HepG2 and SMMC-7721) inhibited proliferation and induced apoptosis. Furthermore, ectopic expression of miR-214 dramatically suppressed the ability of HCC cells to form colonies in vitro and to develop tumors in a subcutaneous xenotransplantation model of the BALB/c athymic nude mice. Moreover, reintroduction of XBP-1s attenuated miR-214-mediated suppression of HCC cells proliferation, colony and tumor formation. To further understand the mechanism of the miR-199a/214 cluster down-expression in HCC, we found that thapsigargin (TG) and tunicamycin (TM) or hypoxia-induced unfolded protein response (UPR) suppresses the expression of the miR-199a/21

β-AR blockers protected cardiomyocytes against ER stress-mediated apoptosis.

<p>(A) β-AR blockers suppressed activation of caspase-12 in H9c2(2–1) cells. Cells were treated with TG (5 µmol/L) or TM (5 µg/ml) with or without metoprolol (10 µmol/L) or propranolol (10 µmol/L) for 12 hours. Cell lysates were then immunoblotted for caspase-12. Caspase-12 cleavage was normalized to β-actin. *P<0.05 vs. control, #P<0.05 vs. TM, & P<0.05 vs. TG. (B) and (C) Hochst-positive cells (%). H9c(2–1) cells were pretreated with metoprolol (10 µmol/L, 1 h) or propranolol (10 µmol/L, 1 h), then exposed to TG (5 µmol/L, 24 h) or TM (5 µg/ml, 24 h) before staining with Hochst33258 as indicated. Hochst-positive cells are expressed as a percentage of the number of total cells. **P<0.001 vs. control. # P<0.05 vs. TG or TM. (D) Anexin V-positive cells (%). H9c(2–1) cells were pretreated with metoprolol (10 µmol/L, 1 h) or propranolol (10 µmol/L, 1 h), then exposed to TG (5 µmol/L, 24 h) before staining with Anexin V/PI as indicated. Analyze by flow cytometry immediately after incubation. Anexin V-positive cells are expressed as a percentage of the number of total cells. *P<0.05 vs. control. #P<0.05 vs. TG.</p

MOESM1 of MicroRNA regulation of unfolded protein response transcription factor XBP1 in the progression of cardiac hypertrophy and heart failure in vivo

Additional file 1. Real-time PCR analysis of the ratio of miR-30a*/miR-214 in mice heart and VEGF and EDEM mRNA in siRNA-XBP1treated H9C2 cells and representative immunostaining of CD31 in hearts are presented

Hemodynamic parameters in AAC rats and AAC rats with β-AR blocker treatment.

<p>HR, heart rate; LVEDP, left ventricular end diastolic pressure; Ea, arterial elastance; dP/dtmax, maximal slope of systolic pressure increment; dP/dt min maximal slope of diastolic pressure decrement; meto, metoprolol; prop, propranolol. Data are mean ± s.d. * P<0.05 versus control; †P<0.05 vs. AAC.</p

β-AR blockers suppressed ER stress-mediated apoptosis in cardiac hypertrophy and failure.

<p>(A) and (B) CHOP was increased in AAC rats (4 or 8 weeks after operation), and metoprolol (30 mg/kg/d for 4 or 8 weeks)or propranolol (30 mg/kg/d for 4 or 8 weeks) treatment reduced expression of CHOP. CHOP was normalized to β-actin. (C) Representative images of TUNEL showing cardiac myocytes apoptosis and quantitative analysis of TUNEL-positive myocardial cells in rats. Nuclei of normal cells are blue, and nuclei of apoptosis cells (TUNEL-positive cells) are brown.</p

β-AR blockers suppressed ER stress in hypertrophic and failing hearts of rats.

<p>(A) ER chaperone GRP78 and spliced XBP-1 were increased in AAC rats (1or 4 or 8 weeks after operation), and metoprolol treatment (30 mg/kg/d for 8 weeks) reduced the epression of GRP78 and spliced XBP-1. Proteins were normalized to β-actin. (B) GRP78 was increased in AAC rats (4 weeks), and propranolol treatment (30 mg/kg/d for 4 weeks) reduced the epression of GRP78. Protein was normalized to β-actin. (C) Immunohistochemical analyses of rats’ hearts and number of GRP78, KDEL and CHOP-positive cells per mm². Scale bar, 40 µm. For (A) to (C), *P<0.05 vs. sham, #P<0.05 vs. AAC. (D) GRP78 and spliced XBP-1 was increased in Iso rats, and metoprolol treatment (30 mg/kg/d for 2 weeks) reduced the epression of GRP78 and spliced XBP-1. Proteins were normalized to β-actin. *P<0.05 vs. control, #P<0.05 vs. Iso.</p

Hemodynamic parameters in Iso rats and Iso rats with β-AR blocker treatment.

<p>HR, heart rate; PES, end-systolic pressure; PED, end-diastolic pressure; dP/dtmax, maximal slope of systolic pressure increment; dP/dt min maximal slope of diastolic pressure decrement; Iso, isoproterenol; meto, metoprolol. Data are mean ± s.d. *P<0.05 vs. control.</p