CYP epoxygenase 2J2 prevents cardiac fibrosis by suppression of transmission of pro-inflammation from cardiomyocytes to macrophages.

Cytochrome P450 epoxygenase (CYP450)-derived epoxyeicosatrienoic acids (EETs) are important regulators of cardiac remodeling; but the underlying mechanism remains unclear. The present study aimed to elucidate how EETs regulated cardiac fibrosis in response to isoprenaline (Iso) or angiotensin (Ang) II. Cardiac-specific human CYP2J2 transgenic mice (Tr) and wild-type (WT) C57BL/6 littermates were infused with Iso- or Ang II. Two weeks after infusion, Tr mice showed more alleviative cardiac fibrosis and inflammation compared with WT mice. In vitro, we found Iso or Ang II induced nuclear transfer of NF-κB p65 and inflammatory cytokines expression in cardiomyocytes. Furthermore, inflammation response emerged in macrophages cultured in cardiomyocytes-conditioned medium. When pretreatment with 14,15-EET in cardiomyocytes, the inflammatory response was markedly suppressed and the transmission of inflammation from cardiomyocytes to macrophages was reduced. In conclusion, CYP2J2 and EETs prevent cardiac fibrosis and cardiac dysfunction by suppressing transmission of pro-inflammation from cardiomyocytes to macrophages in heart, suggesting that elevation of EETs level could be a potential strategy to prevent cardiac fibrosis.

C-reactive protein polymorphisms and genetic susceptibility to ischemic stroke and hemorrhagic stroke in the Chinese Han population.

AIM: The inflammatory marker C-reactive protein (CRP) has been strongly correlated with the risk of cardiovascular disease. Some single-nucleotide polymorphisms (SNPs) have been reported to be associated with serum CRP levels. In this study, we assessed the genetic association between SNPs within the CRP gene and ischemic and hemorrhagic stroke in the Han Chinese population. METHODS: This study comprises 564 ischemic stroke patients, 220 hemorrhagic stroke patients and 564 controls from the ethnic Han Chinese population in Wuhan. Four CRP SNPs, -757A>G (rs3093059), -717A>G (rs2794521), -286C>T>A (rs3091244) and +2147C>T (rs1205), were genotyped from patients using TaqMan assays. RESULTS: The A allele frequency for the -717A>G polymorphism was significant higher in controls than in ischemic stroke patients (P=0.037), after adjustment for traditional risk factors (odds ratio 0.28; 95% CI 0.12-0.65; P=0.003), suggesting a protective effect for this allele against ischemic stroke. Haplotype analysis showed that the H3 (G-C-C) haplotype conferred a significantly increased risk of ischemic stroke (odds ratio 1.052, 95% CI 1.001-1.106: P=0.047). Neither CRP genotypes nor haplotypes showed an association with hemorrhagic stroke. However, the frequency for haplotype H5 (A-T-C) was significantly higher in ischemic stroke than hemorrhagic stroke patients (P=0.0003). CONCLUSION: These data suggest that the CRP gene -717A allele confers a protective effect against ischemic stroke. Furthermore, the H3 haplotype (G-C-C) is an independent risk marker for ischemic stroke, whereas the H5 haplotype (A-T-C) can be used as a prognostic marker of hemorrhagic stroke.

[Upregulated voltage-gated potassium channel Kv1.3 on the CD4+CD28null T lymphocyte from patients with acute coronary syndrome].

OBJECTIVE: The purpose of our study is to observe the voltage-gated potassium channel Kv1.3 expression on CD4+CD28null T cells from the peripheral blood of ACS patients by the patch clamp technique. METHODS: Kv1.3 potassium channels expression from 17 patients with ACS and 11 healthy age-matched normal controls was detected in single cell (CD4+CD28null T cells and CD4+CD28+ T cells) by fluorescence microscopy and patch clamp. RESULTS: The percent of CD4+CD28nullT cells are higher in the ACS (6.97% +/- 2.05%) than that in the controls (1.38% +/- 0.84%, P < 0.05). The concentration of hsCRP is directly correlated with the number of the CD4+CD28null T cells in the ACS (r = 0.52, P < 0.05). The conductance [(6.89 +/- 1.17) nS vs. (3.36 +/- 0.66) nS], dens [(1.95 +/- 0.80) n/microm2 vs. (1.13 +/- 0.57) n/microm2] and numbers [(574.5 +/- 97.6) n/cell vs. (280.3 +/- 55.3) n/cell] of the Kv1.3 channels on the CD4+CD28null T cells are significantly higher than those on the CD4+CD28+ T cells (all P < 0.01) in ACS patients, but were similar on CD4+CD28+ T cells between ACS patients and controls. CONCLUSION: The CD4+CD28null T cells in the ACS and the numbers of Kv1.3 channels on the CD4+CD28null T cells from the ACS patients are significantly upregulated and might contribute to the pathogenesis of ACS.

[Effects of telmisartan on endoplasmic reticulum stress induced cardiomyocyte apoptosis in abdominal aortic banded rats].

OBJECTIVE: To investigate the effects of telmisartan on endoplasm reticulum (ER) stress signal pathways and cardiomyocyte apoptosis in abdominal aortic banded rats. METHODS: Male SD rats were randomly divided into sham-operated group, abdominal aortic banding group (AAB) and AAB + telmisartan (5 mgxkg(-1)xd(-1) per gavage, beginning at 1 week before AAB for 8 weeks, n = 10 each). Ten weeks post AAB, hemodynamic measurements were performed, whole heart and left ventricular weights were obtained, cardiomyocyte apoptosis was measured by TUNEL method. Myocardial GRP78 and CHOP protein expressions were detected by Western blot and immunohistochemistry. RESULTS: The ratio of left ventricular weight to body weight, the ratio of heart weight to body weight, left ventricular end diastolic pressure and the apoptosis index were significantly increased while left ventricular end systolic pressure and +/- dp/dt(max) were significantly decreased in AAB group than those in sham-operated group (all P < 0.01), these changes could be significantly attenuated by telmisartan (all P < 0.01). Moreover, myocardial GRP78 and CHOP expressions were significantly upregulated in AAB group than those in sham-operated group and telmisartan could significantly downregulate the increased GRP78, CHOP expressions (all P < 0.01). CONCLUSIONS: Increased ER stress might be responsible for enhanced cardiomyocyte apoptosis in AAB rats. Telmisartan effectively attenuated the cardiomyocyte apoptosis and cardiac hypertrophy in AAB rats possibly through reducing ER stress.

Mechanism of oxidative stress-induced GADD153 gene expression in vascular smooth muscle cells.

Oxidative stress plays a critical role in normal functioning of cardiac and vascular cells as well as in the pathogenesis of cardiovascular disease. Growth arrest and DNA damage-inducible gene 153 (GADD153), which is upregulated by oxidative stress, regulates the cell cycle and apoptosis. Previously an AP-1 was reported to contribute significantly to GADD153 gene transcriptional activation by oxidative stress. Recently, we have reported that GADD153 gene promoter activity is negatively regulated by nuclear factor 1 (NF1), in vascular smooth muscle cells (VSMCs). The aim of this study was to elucidate the roles of AP-1 and NF1 in GADD153 gene induction by oxidative stress in VSMCs. H(2)O(2) induced GADD153 mRNA and reduced NF1 mRNA expression. In the electromobility shift assay, H(2)O(2) induced AP-1-binding activity and reduced NF1-binding activity. Overexpression of NF1 significantly suppressed the induction of the GADD153 gene after treatment with H(2)O(2). These results revealed that induction of the GADD153 gene by oxidative stress is regulated mainly by two nuclear factors, NF1 and AP-1.