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Background/Aims: Recent studies have shown that circulating microRNAs (miRNAs) are emerging as promising biomarkers for cardiovascular diseases. This study aimed to determine whether miR-19b-3p, miR-134-5p and miR-186-5p can be used as novel indicators for acute myocardial infarction (AMI). Methods: To investigate the kinetic expression of the three selected miRNAs, we enrolled 18 patients with AMI and 20 matched controls. Plasma samples were collected from each participant, and total RNA was extracted. Quantitative real-time PCR and ELISA assays were used to investigate the expression of circulating miRNAs and cardiac troponin I (cTnI), respectively. Plasma samples from another age- and gender-matched cohort were collected to investigate the impact of medications for AMI on the expression of the selected miRNAs. Results: Levels of plasma miR-19b-3p, miR-134-5p and miR-186-5p were significantly increased in early stage of AMI. Plasma miR-19b-3p and miR-134-5p levels reached peak expression immediately after admission (T0), whereas miR-186-5p achieved peak expression at 4 h after T0. All of these times were earlier than the peak for cTnI (8 h after T0). In addition, all three miRNAs were positively correlated with cTnI. Receiver Operating Characteristic (ROC) analysis indicated that each single miRNA showed considerable diagnostic efficiency for predicting AMI. Furthermore, combining all three miRNAs in a panel increased the efficiency of distinguishing between patients with AMI and controls. Moreover, we found that heparin and medications for AMI did not impact the expression of these circulating miRNAs. Conclusion: Circulating miR-19b-3p, miR-134-5p and miR-186-5p could be considered promising novel diagnostic biomarkers for the early phase of AMI.

Although neural stem cell (NSC) transplantation is widely expected to become a therapy for nervous system degenerative diseases and injuries, the low neuronal differentiation rate of NSCs transplanted into the inner ear is a major obstacle for the successful treatment of spiral ganglion neuron (SGN) degeneration. In this study, we validated whether the local microenvironment influences the neuronal differentiation of transplanted NSCs in the inner ear. Using a rat SGN degeneration model, we demonstrated that transplanted NSCs were more likely to differentiate into microtubule-associated protein 2 (MAP2)-positive neurons in SGN-degenerated cochleae than in control cochleae. Using real-time quantitative PCR and an immunofluorescence assay, we also proved that the expression of Wnt1 (a ligand of Wnt signaling) increases significantly in Schwann cells in the SGN-degenerated cochlea. We further verified that NSC cultures express receptors and signaling components for Wnts. Based on these expression patterns, we hypothesized that Schwann cell-derived Wnt1 and Wnt signaling might be involved in the regulation of the neuronal differentiation of transplanted NSCs. We verified our hypothesis in vitro using a coculture system. We transduced a lentiviral vector expressing Wnt1 into cochlear Schwann cell cultures and cocultured them with NSC cultures. The coculture with Wnt1-expressing Schwann cells resulted in a significant increase in the percentage of NSCs that differentiated into MAP2-positive neurons, whereas this differentiation-enhancing effect was prevented by Dkk1 (an inhibitor of the Wnt signaling pathway). These results suggested that Wnt1 derived from cochlear Schwann cells enhanced the neuronal differentiation of transplanted NSCs through Wnt signaling pathway activation. Alterations of the microenvironment deserve detailed investigation because they may help us to conceive effective strategies to overcome the barrier of the low differentiation rate of transplanted NSCs.

OBJECTIVE: CD4(+) latency-associated peptide (LAP)(+) regulatory T cells (Tregs) are a newly discovered T cell subset in humans and the role of these cells in patients with acute coronary syndrome (ACS) has not been explored. We designed to investigate whether circulating frequency and function of CD4(+)LAP(+) Tregs are defective in ACS. METHODS: One hundred eleven ACS patients (acute myocardial infarction and unstable angina) and 117 control patients were enrolled in the study. The control patients consisted of chronic stable angina (CSA) and chest pain syndrome (CPS). The frequencies of circulating CD4(+)LAP(+) Tregs and the expression of the transmembrane protein glycoprotein-A repetitions predominant (GARP) on CD4(+) T cells were determined by flow cytometry. The function of CD4(+)LAP(+) Tregs was detected using thymidine uptake. Serum interleukin-10 (IL-10) and transforming growth factor-β protein (TGF-β) levels were detected using ELISA and expression of GARP mRNA in peripheral blood mononuclear cells (PBMCs) was measured by real time-polymerase chain reaction. RESULTS: We found ACS patients had a significantly lower frequency of circulating CD4(+)LAP(+) Tregs, and the function of these cells was reduced compared to controls. The expression of GARP in CD4(+) T cells and the serum levels of TGF-β in ACS patients were lower than those of control patients. The serum levels of IL-10 were similar between the two cohorts. CONCLUSIONS: A novel regulatory T cell subset, defined as CD4(+)LAP(+) T cells is defective in ACS patients.

BACKGROUND: A reduction in cochlear blood flow plays an essential role in noise-induced hearing loss (NIHL). The timely regulation of cochlear perfusion determines the progression and prognosis of NIHL. Hydrogen sulfide (H(2)S) has attracted increasing interest as a vasodilator in cardiovascular systems. This study identified the role of H(2)S in cochlear blood flow regulation and noise protection. METHODOLOGY/PRINCIPAL FINDINGS: The gene and protein expression of the H(2)S synthetase cystathionine-γ-lyase (CSE) in the rat cochlea was examined using immunofluorescence and real-time PCR. Cochlear CSE mRNA levels varied according to the duration of noise exposure. A chronic intracochlear infusion model was built and artificial perilymph (AP), NaHS or DL-propargylglycine (PPG) were locally administered. Local sodium hydrosulfide (NaHS) significantly increased cochlear perfusion post-noise exposure. Cochlear morphological damage and hearing loss were alleviated in the NaHS group as measured by conventional auditory brainstem response (ABR), cochlear scanning electron microscope (SEM) and outer hair cell (OHC) count. The highest percentage of OHC loss occurred in the PPG group. CONCLUSIONS/SIGNIFICANCE: Our results suggest that H(2)S plays an important role in the regulation of cochlear blood flow and the protection against noise. Further studies may identify a new preventive and therapeutic perspective on NIHL and other blood supply-related inner ear diseases.

We report here the identification of the key sites for the beta structure motifs of the islet amyloid polypeptide (IAPP) analogs by using scanning tunneling microscopy (STM). Duplex folding structures in human IAPP8-37 (hIAPP8-37) assembly were observed featuring a hairpin structure. The multiplicity in rIAPP assembly structures indicates the polydispersity of the rat IAPP8-37 (rIAPP8-37) beta-like motifs. The bimodal length distribution of beta structure motifs for rIAPP8-37 R18H indicates the multiple beta segments linked by turns. The IAPP8-37 analogs share common structure motifs of IAPP8-17 and IAPP26-37 with the most probable key sites at positions around Ser19/Ser20 and Gly24. These observations reveal the similar amyloid formation tendency in the C and N terminus segments because of the sequence similarity, while the differences in specific amino acids at each key site manifest the effect of sequence variations. The results could be beneficial for studying structural polymorphism of amyloidal peptides with multiple beta structure motifs. [ABSTRACT FROM AUTHOR]

Many studies have suggested that VSMC (vascular smooth muscle cell) apoptosis plays a key role in destabilization and rupture of atherosclerotic plaques. Therefore protection for VSMCs from apoptosis is a promising approach to stabilize 'vulnerable' lesions. However, the mechanisms as to why VSMCs in the fibrous cap often appear as profilerated in early stages, but turn apoptotic in advanced stages, are still unknown. In the present study, using RNAi (RNA interference) technology and a CaN (calcineurin) antagonist, the correlation between CaN and RANTES (regulated upon activation, normal T-cell expressed and secreted) in cultured rat apoptotic VSMCs stimulated by IFNγ (interferon γ; 20 ng/ml) and CD40L (CD40 ligand; 100 ng/ml) was investigated. RANTES released from VSMCs in each group was measured by ELISA and its mRNA in VSMCs was determined by RT (reverse transcription)-PCR. The total activity and expression of CaN in VSMCs were detected by the zymochemistry method and Western blot analysis respectively. From the results of the present study it can be hypothesized that an elevated CaN concentration in endochylema, by the CD40-CD40L signal pathway, induces VSMC apoptosis accomplished by the overexpression of RANTES. Therefore RANTES is a potential target for treating vulnerable atherosclerotic plaques owing to its crucial downstream regulating role in CaN-dependent VSMC apoptosis. [ABSTRACT FROM AUTHOR]

Previous studies demonstrated that metformin has obvious antiatherogenic properties, but the exact mechanism remains unclear. Therefore, we established an atherosclerotic rabbit model in order to investigate the potential effects of metformin on transcription factor nuclear factor κB (NF-κB) and serum high-sensitivity C-reactive protein (hs-CRP) level, which had been regarded as proatherogenic factors. New Zealand rabbits were randomly divided into three groups: a control group ( n = 8), an atherosclerotic group (AS group, n = 8), and a metformin treatment group (Met group, n = 8). The experimental atherosclerotic rabbit model was successfully established at the end of the 8th week. From the 9th week, rabbits in the Met group were administered with 150 mg/kg metformin daily by gavage. Blood samples were collected at days 0 and 8, and at 16 weeks to detect the level of blood lipid and serum glucose. At the end of the experiment, blood samples were withdrawn for determining serum hs-CRP. Aortic samples were harvested for histomorphometric analysis. Immunohistochemistry and Western blotting were used to detect the expression of NF-κB subunit p65 in nuclear extracts and phosphorylation of inhibitor of nuclear factor κB (IκB) in cytoplasmic extracts. An experimental atherosclerotic rabbit model was successfully established. The expression of nuclear NF-κB subunit p65 and cytoplasmic phosphorylation of IκB protein in the vessel wall was enhanced ( P < 0.01, respectively) in the AS group, and serum hs-CRP level was significantly increased in the AS group compared with the control group (3.90 ± 0.25 mg/l versus 1.36 ± 0.14 mg/l, P < 0.01). Treatment with metformin significantly attenuated the progression of aortic atherosclerosis. In the Met group, there was a marked reduction in nuclear NF-κB subunit p65 and cytoplasmic phosphorylation of IκB protein expression ( P < 0.01). Serum hs-CRP concentration was also significantly decreased (3.20 ± 0.20 mg/l versus 3.90 ± 0.25 mg/l, P < 0.05). Metformin inhibits the phosphorylation of IκB and the activation of NF-κB in the vessel wall of experimental atherogenesis of rabbits, as well as decreasing the serum level of hs-CRP, thus suggesting that metformin has vascular anti-inflammatory properties, which may be one of its antiatherogenic mechanisms. [ABSTRACT FROM AUTHOR]

Abstract Purpose  Pioglitazone, used clinically in the treatment of type 2 diabetes mellitus, has been implicated as a regulator of cellular inflammatory and ischemic responses. The present study examined whether pioglitazone could inhibit cadiocyte apoptosis and reduce mitochondrial ultrastructure injury and membrane potential loss in the ischemic/reperfused heart of the rat. Furthermore, we investigated whether the protective effect of pioglitazone was related to opening of the mitochondrialATP-sensitive potassium channels. Methods  Adult male Sprague–Dawley rats were subjected to 30 min of ischemia followed by 4 h of reperfusion. At 24 h before ischemia, rats were randomized to receive 0.9% saline, 5-hydroxydecanoate (5-HD, 10 mg kg−1, i.v.) plus pioglitazone (3 mg kg−1, i.v.) or pioglitazone (3 mg kg−1, i.v.). One group served as sham control. We investigated mitochondrial structure, apoptosis rate and Bcl-2, Bax and Caspase-3 proteins by immunohistochemistry staining. RT-PCR was used to determine the expression of P38MAPKmRNA and JNKmRNA. Western blotting was used to measure the expression of P38MAPK, JNK and NFκB P65. A second group of rats were randomly divided into sham-operated, ischemia/reperfusion (I/R), pioglitazone treatment, 5-HD  pioglitazone and 5-HD groups and the size of myocardial infarction was determined. Primary cultured cardiomyocytes of neonatal Sprague–Dawley rats were divided into control, hypoxia reoxygenation, different concentrations of pioglitazone and 5-HD  pioglitazone groups. JC-1 staining flowcytometry was used to examine mitochondrial membrane potential (ΔΨm). Results  Pioglitazone decreased mitochondrial ultrastructural damage compared to I/R, and reduced infarct size from 34.93 ± 5.55% (I/R) to 20.24 ± 3.93% (P P P P P  Conclusion  Pioglitazone inhibited cadiocyte apoptosis and reduced mitochondrial ultrastructure injury and membrane potential loss in the ischemic/reperfused heart of rat. These protective effects of pioglitazone may be related to opening mitochondrialATP-sensitive potassium channels. [ABSTRACT FROM AUTHOR]