[MicroRNA-21 protects cardiomyocytes from tumor necrosis factor-α induced apoptosis in vitro via modulating PTEN/AKT/FOXO3a pathway].

OBJECTIVE: To explore the effect of microRNA-21 on tumor necrosis factor (TNF)-α induced cardiomyocytes apoptosis and the association with PTEN/AKT/FOXO3a signaling pathway. METHODS: Neonatal cardiomyocytes were isolated and cultured in vitro. Cardiomyocytes apoptosis was induced by TNF-α (10 ng/ml for 24 h) and examined by the cardiomyocytes apoptotic index. Eukaryotic expression vector for lenti-microRNA-21 was established and then transferred into the cardiomyocytes. MicroRNA-21 and PTEN mRNA were examined by qRT-PCR. Intracellular signal molecules, such as the expression of PTEN, phosphorylated PTEN, AKT, phosphorylated AKT (pAKTser473, pAKTThr308), FOXO3a, phosphorylated FOXO3a and FasL were detected by Western blot. RESULTS: MicroRNA-21 reduced TNF-α induced cardiomyocytes apoptosis [(23.42 ± 1.98)% vs. (78.37 ± 2.03)%, P < 0.05]. TNF-α downregulated the expression of microRNA-21 and upregulated the mRNA and protein expressions of PTEN. Phosphorylation of PTEN, AKT and FOXO3a was enhanced in cardiomyocytes transfected with lenti-microRNA-21 (P < 0.05). TNF-α also significantly activated the phosphorylation of PTEN, AKT and FOXO3a (P < 0.05). Compared with cardiomyocytes treated with TNF-α (10 ng/ml), the phosphorylation of PTEN, AKT and FOXO3a as well as expression of pPTEN, pAKTser473, pFOXO3a and FasL were significantly suppressed in cardiomyocytes treated with lenti-microRNA-21 and TNF-α (P < 0.05). Total AKT and FOXO3a were similar among all groups (P > 0.05). CONCLUSIONS: MicroRNA-21 could protect cardiomyocytes from TNF-α- induced apoptosis through PTEN/AKT/FOXO3a pathway, which might serve as a new therapy option for various cardiovascular diseases in the future.

Development of the Chinese version of the Dentine Hypersensitivity Experience Questionnaire.

The aim of this study was to evaluate the reliability and the validity of the Chinese version of the Dentine Hypersensitivity Experience Questionnaire (DHEQ). After translation and cross-cultural adaptation following international guidelines, 110 patients with dentine hypersensitivity were recruited to complete the questionnaire. The reliability of the Chinese version of the DHEQ was evaluated using internal consistency and test-retest methods. Construct validity was determined based on factor analysis, discriminative validity (by comparing the subscale scores difference in the degree of sensitivity being investigated), and convergent validity (by analyzing the correlation between DHEQ subscale scores and the global rating of oral health question). Cronbach's alpha value (internal reliability) for the total DHEQ score was 0.95 and the intraclass correlation coefficient (ICC) value (test-retest reliability) was 0.85. Construct validity was determined by factor analysis, extracting eight factors, accounting for 74% of the variance. All items had factor loadings of >0.40. In addition, the Chinese version of the DHEQ was found to be valid for distinguishing patients with varying degrees of dentine hypersensitivity. In terms of convergent validity, the impact scale was significantly highly correlated to the global oral health rating. The results suggest that the Chinese version of the DHEQ has satisfactory psychometric properties and is applicable for patients with dentine hypersensitivity in China.

[Role of liver X receptors on cardiomyocyte hypertrophy].

OBJECTIVE: To investigate the expression of liver X receptors (LXR) in hypertrophic myocardium and the effect of LXR agonist T0901317 on angiotensin II (AngII) induced cardiomyocyte hypertrophy. METHODS: Transverse aortic coarctation (TAC) or sham operation were performed in 2-month-old wide type mice (C57/B6). Two weeks later, the expression of LXR in myocardium was detected by quantitative real-time PCR analysis and Western blot analysis. The effect of LXR agonist T0901317 on AngII-induced hypertrophy in cultured neonatal rat cardiomyocytes was also assessed. RESULTS: Quantitative real-time PCR analysis and Western blot analysis showed that LXRalpha but not LXRbeta expression was upregulated post TAC both at mRNA and protein levels (All P < 0.05). AngII induced increased [(3)H] leucine incorporation and cardiomyocyte hypertrophy were significantly reduced by T0901317 in a dose-dependent manner (P < 0.05). T0901317 also dose-dependently inhibited atrial natriuretic peptide (ANP) gene expression in cardiomyocytes (P < 0.05). CONCLUSION: Our findings strongly suggest that LXR is a potent mediator of cardiomyocyte hypertrophy and LXR activation could attenuate AngII induced cardiomyocyte hypertrophy in vitro.

[Effects of Xuezhikang on serum levels of high sensitive-C reactive protein, matrix metalloproteinase-9 and lipoprotein in patients with acute coronary syndrome].

OBJECTIVE: To investigate the effects of Xuezhikang (XZK) on serum levels of high sensitivity-C reactive protein (Hs-CRP), matrix metalloproteinase-9 (MMP-9) and lipoprotein in patients with acute coronary syndrome (ACS). METHODS: Sixty-nine ACS patients were divided into the XZK group (40 cases) treated with conventional therapy and XZK and the control group (29 cases) with conventional therapy alone, another 30 healthy persons were assigned as the normal group. Before and after the treatment, the levels of Hs-CRP, MMP-9 and lipids were detected. RESULTS: Compared with those in the normal subjects, Hs-CRP and MMP-9 levels in the ACS patients increased significantly (P <0.05), parallel with the extent of myocardial injury. After 2 weeks of XZK treatment, levels of Hs-CRP and MMP-9 of the XZK group decreased significantly (P <0.05), while lipids levels had no remarkable changes. CONCLUSION: Hs-CRP and MMP-9 levels were closely correlated to the genesis and severity of ACS. Anti-inflammatory action of XZK plays an important role in early stage treatment of ACS patients.

N-acetylcysteine Attenuates Cobalt Nanoparticle-Induced Cytotoxic Effects through Inhibition of Cell Death, Reactive Oxygen Species-related Signaling and Cytokines Expression.

OBJECTIVE: Complex cobalt-chromium alloys, bearing surfaces of the second-generation metal-on-metal (MoM) hip prostheses, are subject to wear and generate cobalt nanoparticles (CoNPs). CoNPs could reduce cellular viability, activate the mitogen-activated protein kinase (MAPK) pathway and increase cell apoptosis via reactive oxygen species (ROS). However, the detailed mechanisms of ROS functioning on CoNP-mediated signaling molecules and cytotoxicity has not yet been fully demonstrated. The present study investigated the functional role of N-acetylcysteine (NAC) in reversing the activation of ROS signaling pathways triggered by CoNPs in normal mice kidney cells (TCMK-1 cells). METHODS: After being pretreated with NAC, TCMK-1 cells were treated with 300-700 µmol/L CoNPs, then, CCK-8 assay was used to verify the survival of TCMK-1 cells. Annexin V/PI staining was performed to investigate the apoptosis of TCMK-1 cells after NAC and different concentrations of CoNP treatments. In addition, western blot was performed to identify the cytokine (p-ERK, p-p38, and p-JNK) expression of the ROS-related MAPK signaling pathway. RESULTS: Apoptosis rate of TCMK-1 cells was increased obviously after different concentrations of CoNP treatment. However, TCMK-1 cells, pretreated with NAC, exhibited a significantly decreased apoptosis rate. In addition, p-ERK, p-p38, and p-JNK expressions were increased with CoNP treatment, which indicated that CoNPs could activate the MAPK pathway. Interestingly, this entire stimulated phenomenon by CoNPs was reversed with NAC treatment. CONCLUSIONS: These findings indicated that NAC could reverse CoNP-induced cytotoxicity by inhibiting ROS-induced cell death and cytokine expression. To our knowledge, this is the first report that describes how CoNP-induced cytotoxicity in TCMK-1 cells could be attenuated by anti-oxidative agents (NAC), which may function through inhibition of cell death and ROS.

Relationship between hOGG1 Ser326Cys gene polymorphism and coronary artery lesions in patients with diabetes mellitus.

To study the relationship between human 8-oxoguanine glycosylase (hOGG1) Ser326Cys gene polymorphism and coronary artery lesions in patients with diabetes mellitus, we analyzed 323 patients with diabetic mellitus, who underwent coronary angiography. Using PCR-RFLP, these patients were grouped into three genotypes: Cys/Cys (n=85), Ser/Ser (n=121), and Ser/Cys (n=117). Several clinical data, including history of diseases and biochemical indices were recorded. hOGG1 mRNA expression and 8-hydroxy deoxyguanosine (8-OHdG) were measured by RT-PCR and ELISA, respectively. The quantities and severity of coronary artery with lesions were analyzed from coronary angiography. The Gensini and SYNTAX scores were detected by the unitary criteria. The 8-OHdG levels showed statistical difference among the three genotypes (F=21.56, P<0.05). Also, 8-OHdG in Cys/Cys genotype was higher than Ser/Ser and Ser/Cys genotype (q=2.32, q=3.12, P<0.05). In terms of the expression of hOGGl mRNA, the measure of hOGGl/ß-actin showed significant difference among the three groups (F=12.56, P<0.05). On comparing two groups, hOGGl/ß-actin in Cys/Cys genotype was higher thanSer/Ser and Ser/Cys genotypes (q=2.32, q=3.12, P<0.05). Percentage of 3-vessel lesions was high in Cys/Cys genotype and percentage of 1-vessel lesions was low in Ser/Cys genotype. Gensini and SYNTAX scores and ratio of complex lesions were significantly higher in the Cys/Cys genotype than the other two genotypes (FGensini=47.16, FSYNTAX=55.12; P<0.05). hOGG1 Ser326Cys polymorphism showed correlation with coronary artery lesions in patients with diabetes mellitus, and Cys/Cys genotype may have more impact on the severity of lesions.

[Epidemiological survey of dentine hypersensitivity of 630 adults in rural of Sichuan province].

OBJECTIVE: To investigate the prevalence and potential risk factors of dentine hypersensitivity of adults in rural of Sichuan province. METHODS: All representative samples, including 630 adults living in rural of Sichuan Province, were selected by multi-stage, stratified and random sampling. The dentine hypersensitivity of all 630 cases was surveyed with questionnaire and oral clinical examination. SPSS 18.0 software was used for statistical analysis. RESULTS: 27.9% of all subjects were suffered from dentine hypersensitivity, sour was the most common stimulus of dentine hypersensitivity. The first premolar was the most common tooth with dentine hypersensitive, which occupied 27.4% of the total affected teeth. Female, acid regurgitation symptom, low frequency of toothbrush replacement (over 3 months), high tooth-brushing force and frequency of fresh fruits consumption (over 2 times per week) probably were high risk factors of dentine hypersensitivity. CONCLUSION: The prevalence of dentine hypersensitivity occurs in rural of Sichuan province is high, thus for future the publicity and education on dentine hypersensitivity preventive should be strengthened.