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The Nrf2-p27(kip1) pathway serves as a novel negative feedback mechanism in Ang II-induced pathogenesis of cardiac hypertrophy, independent of changes in blood pressure.

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It is increasingly recognized that vitamin D deficiency is associated with increased risks of metabolic disorders among overweight children. A recent study showed that vitamin D deficiency exacerbated inflammation in nonalcoholic fatty liver disease through activating toll-like receptor 4 in a high-fat diet (HFD) rat model. The present study aimed to further investigate the effects of vitamin D deficiency on HFD-induced insulin resistance and hepatic lipid accumulation. Male ICR mice (35 d old) were randomly assigned into 4 groups as follows. In control diet and vitamin D deficiency diet (VDD) groups, mice were fed with purified diets. In HFD and VDD+HFD groups, mice were fed with HFD. In VDD and VDD+HFD groups, vitamin D in feed was depleted. Feeding mice with vitamin D deficiency diet did not induce obesity, insulin resistance, and hepatic lipid accumulation. By contrary, vitamin D deficiency markedly alleviated HFD-induced overweight, hyperinsulinemia, and hepatic lipid accumulation. Moreover, vitamin D deficiency significantly attenuated HFD-induced up-regulation of hepatic peroxisome proliferator-activated receptor γ, which promoted hepatic lipid uptake and lipid droplet formation, and its target gene cluster of differentiation 36. In addition, vitamin D deficiency up-regulated carnitine palmitoyltrans 2, the key enzyme for fatty acid β-oxidation, and uncoupling protein 3, which separated oxidative phosphorylation from ATP production, in adipose tissue. These data suggest that vitamin D deficiency is not a direct risk factor for obesity, insulin resistance, and hepatic lipid accumulation. Vitamin D deficiency alleviates HFD-induced overweight, hyperinsulinemia, and hepatic lipid accumulation through promoting fatty acid β-oxidation and elevating energy expenditure in adipose tissue.

Acetaminophen (APAP) overdose is the most frequent cause of acute liver failure and is primarily caused by cytochrome P450 (CYP) 2E1-driven conversion of APAP into hepatotoxic metabolites. Several reports showed that melatonin attenuated APAP-induced acute liver failure. Nevertheless, the exact mechanism remains obscure. In the present study, we investigated the effects of melatonin on apoptosis-inducing factor (AIF)-dependent cell death in APAP-induced acute liver failure. Mice were intraperitoneally (i.p.) injected with different doses of melatonin (1.25, 5, 20 mg/kg) 30 min before APAP (300 mg/kg, i.p.). As expected, melatonin significantly alleviated APAP-induced cell death, as determined by TdT-mediated dUTP-biotin nick end labeling (TUNEL) assay. Further analysis showed that melatonin significantly attenuated APAP-induced activation of the serine/threonine kinase receptor interacting protein 1 (RIP1). In addition, melatonin inhibited APAP-induced hepatic c-Jun N-terminal kinase (JNK) phosphorylation and mitochondrial Bax translocation. Correspondingly, melatonin inhibited APAP-induced translocation of AIF from mitochondria to nuclei. Interestingly, no changes were induced by melatonin on hepatic CYP2E1 expression. In addition, melatonin had little effect on APAP-induced hepatic glutathione (GSH) depletion. In conclusion, melatonin protects against AIF-dependent cell death during APAP-induced acute liver failure through its direct inhibition of hepatic RIP1 and subsequent JNK phosphorylation and mitochondrial Bax translocation.

Economy has developed rapidly in China, and the clustering of cardiovascular risk factors in subjects increased remarkably over the past two decades. However, no data are available regarding the temporal prevalence of hyperuricemia and its correlates in this rapidly developing area, especially in the inland area. The cross-sectional survey was based on a random sample of 4,218 residents aged 35-64 years in the Jinan area. Hyperuricemia was defined as serum uric acid ≥ 416 μmol/L in men and ≥ 357 μmol/L in women. Subjects underwent physical examination and fasting blood testing. Complete data were available for analysis from 1,979 men and 2,062 women. The age-adjusted prevalence of hyperuricemia was 6.4 % for men and 2.1 % for women. The prevalence of hyperuricemia was greater in urban (6.7 %) than in rural areas (1.7 %) of Jinan city. Multivariate logistic regression models revealed hyperuricemia associated with hypertriglyceridemia [men: odds ratio (OR) = 6.101, 95 % confidence interval (CI) 4.064-9.159; women: OR = 7.103, 95 % CI 3.578-14.099] and high serum creatinine level (men: OR = 2.603, 95 % CI 1.602-4.230; women: OR = 5.237, 95 % CI 2.667-10.284). Hyperuricemia was also significantly associated with male sex, urban residence, hypertension, obesity, and hypercholesterolemia. Age (1-year increase) was negatively associated with hyperuricemia in men but positively associated with hyperuricemia in women. In conclusion, the prevalence of hyperuricemia is higher in urban than rural areas of Jinan, China. Male sex, urban residence, hypertension, obesity, hypercholesterolemia, hypertriglyceridemia, and high serum creatinine level contributed to hyperuricemia in this population.

Background/Aims: Previous studies have suggested that myricetin (Myr) could promote the expression and nuclear translocation of nuclear factor (erythroid-derived 2)-like (Nrf2). This study aimed to investigate whether Myr could attenuate diabetes-associated kidney injuries and dysfunction in wild-type (WT) and Nrf2 knockdown (Nrf2-KD) mice. Methods: Lentivirus-mediated Nrf2-KD and WT mice were used to establish type 1 diabetes mellitus (DM) by streptozotocin (STZ) injection. WT and Nrf2-KD mice were then randomly allocated into four groups: control (CON), Myr, STZ, and STZ + Myr. Myr (100 mg/kg/day) or vehicle was administered for 6 months. Kidneys were harvested and weighed at the end of the experiment. Hematoxylin and eosin staining and Masson’s trichrome staining were used to assess the morphology and fibrosis of the kidneys, respectively. Urinary albumin-to-creatinine ratio was used to test renal function. Western blotting was performed to determine oxidative-stress- or inflammation-associated signaling pathways. Real-time polymerase chain reaction (RT-PCR) was performed to detect the expression of fibrosis or inflammatory cytokines at the message Ribonucleic Acid (mRNA) level. Results: In WT mice, Myr alleviated DM-induced renal dysfunction, fibrosis, and oxidative damage and enhanced the expression of Nrf2 and its downstream genes. After knockdown of Nrf2, Myr treatment partially but significantly mitigated DM-induced renal dysfunction and fibrosis, which might be associated with inhibition of the I-kappa-B (IκB)/nuclear factor-κB (NF-κB) (P65) signaling pathway. Conclusions: This study showed that Myr prevented DM-associated decreased expression of Nrf2 and inhibited IκB/NF-κB (P65) signaling pathway. Moreover, inhibition of IκB/NF-κB (P65) signaling pathway is independent of the regulation of Nrf2. Thus, Myr could be a potential treatment for preventing the development and progression of DM-associated kidney injuries and dysfunction.

Several studies explored the association between vitamin D status and nonalcoholic fatty liver disease with contradictory results. We aimed to investigate the association between vitamin D status, inflammatory cytokines and liver fibrosis in nonalcoholic fatty liver disease patients. Two hundred nineteen nonalcoholic fatty liver disease patients and 166 age- and gender- matched healthy controls were recruited for this study. Serum 25(OH)D was measured by radioimmunoassay. Serum interleukin-8 and transforming growth factor-β1 were measured using ELISA. Serum 25(OH)D was only marginally decreased in nonalcoholic fatty liver disease patients. Interestingly, serum 25(OH)D was markedly reduced in nonalcoholic fatty liver disease patients with advanced liver fibrosis compared to nonalcoholic fatty liver disease patients with indeterminate liver fibrosis and no advanced fibrosis. Logistic regression analysis showed that there was an inverse association between serum 25(OH)D and severity of liver fibrosis in nonalcoholic fatty liver disease patients. Further analysis showed that serum interleukin-8 was elevated in nonalcoholic fatty liver disease patients, the highest interleukin-8 in patients with advanced fibrosis. An inverse correlation between serum 25(OH)D and interleukin-8 was observed in nonalcoholic fatty liver disease patients with and without liver fibrosis. Although serum transforming growth factor-β1 was slightly elevated in nonalcoholic fatty liver disease patients, serum transforming growth factor-β1 was reduced in nonalcoholic fatty liver disease patients with advanced fibrosis. Unexpectedly, a positive correlation between serum 25(OH)D and transforming growth factor-β1 was observed in nonalcoholic fatty liver disease patients with advanced fibrosis. In conclusion, low vitamin D status is associated with advanced liver fibrosis in nonalcoholic fatty liver disease patients. Interleukin-8 may be an important mediator for hepatic fibrosis in nonalcoholic fatty liver disease patients with low vitamin D status.