Accumulating evidence has implicated that GLP-1 may have a beneficial effect on cardiovascular and renal diseases but the mechanism is not fully understood. Here we show that GLP-1 analog, liraglutide, inhibits oxidative stress and albuminuria in streptozotocin (STZ)-induced type 1 diabetes mellitus rats, via a protein kinase A (PKA)-mediated inhibition of renal NAD(P)H oxidases. Diabetic rats were randomly treated with subcutaneous injections of liraglutide (0.3 mg/kg/12 h) for 4 weeks. Oxidative stress markers (urinary 8-hydroxy-2'-deoxyguanosine and renal dihydroethidium staining), expression of renal NAD(P)H oxidase components, transforming growth factor-β (TGF-β), fibronectin and urinary albumin excretion were measured. In vitro effect of liraglutide was evaluated using cultured renal mesangial cells. Administration of liraglutide did not affect plasma glucose levels or body weights in STZ diabetic rats, but normalized oxidative stress markers, expression of NAD(P)H oxidase components, TGF-β, fibronectin in renal tissues and urinary albumin excretion, all of which were significantly increased in diabetic rats. In addition, in cultured renal mesangial cells, incubation with liraglutide for 48 h inhibited NAD(P)H-dependent superoxide production evaluated by lucigenin chemiluminescence in a dose-dependent manner. This effect was reversed by both PKA inhibitor H89 and adenylate cyclase inhibitor SQ22536, but not by Epac2 inhibition via its small interfering RNA. Liraglutide may have a direct beneficial effect on oxidative stress and diabetic nephropathy via a PKA-mediated inhibition of renal NAD(P)H oxidase, independently of a glucose-lowering effect.

We and other investigators have reported that bilirubin and its precursor biliverdin may have beneficial effects on diabetic vascular complications, including nephropathy, via its antioxidant effects. Here, we investigated whether phycocyanin derived from Spirulina platensis, a blue-green algae, and its chromophore phycocyanobilin, which has a chemical structure similar to that of biliverdin, protect against oxidative stress and renal dysfunction in db/db mice, a rodent model for Type 2 diabetes. Oral administration of phycocyanin (300 mg/kg) for 10 wk protected against albuminuria and renal mesangial expansion in db/db mice, and normalized tumor growth factor-β and fibronectin expression. Phycocyanin also normalized urinary and renal oxidative stress markers and the expression of NAD(P)H oxidase components. Similar antioxidant effects were observed following oral administration of phycocyanobilin (15 mg/kg) for 2 wk. Phycocyanobilin, bilirubin, and biliverdin also inhibited NADPH dependent superoxide production in cultured renal mesangial cells. In conclusion, oral administration of phycocyanin and phycocyanobilin may offer a novel and feasible therapeutic approach for preventing diabetic nephropathy.

Intrauterine environment may influence the health of postnatal offspring. There have been many studies on the effects of maternal high-fat diet (HFD) on diabetes and glucose metabolism in offspring. Here, we investigated the effects in male and female offspring. C57/BL6J mice were bred and fed either control diet (CD) or HFD from conception to weaning, and offspring were fed CD or HFD from 6 to 20 wk. At 20 wk, maternal HFD induced glucose intolerance and insulin resistance in offspring. Additionally, liver triacylglycerol content, adipose tissue mass, and inflammation increased in maternal HFD. In contrast, extending previous observations, insulin secretion at glucose tolerance test, islet area, insulin content, and PDX-1 mRNA levels in isolated islets were lower in maternal HFD in males, whereas they were higher in females. Oxidative stress in islets increased in maternal HFD in males, whereas there were no differences in females. Plasma estradiol levels were lower in males than in females and decreased in offspring fed HFD and also decreased by maternal HFD, suggesting that females may be protected from insulin deficiency by inhibiting oxidative stress. In conclusion, maternal HFD induced insulin resistance and deterioration of pancreatic ␤-cell function, with marked sex differences in adult offspring accompanied by adipose tissue inflammation and liver steatosis. Additionally, our results demonstrate that potential mechanisms underlying sex differences in pancreatic ␤-cell function may be related partially to increases in oxidative stress in male islets and decreased plasma estradiol levels in males.

The Lactobacillus gasseri SBT2055 (LG2055) is a probiotic lactic acid bacterium with properties such as bile tolerance and ability to improve the intestinal environment. In this study, we established that the oral administration of LG2055 exhibits efficacy to protect mice infected with the influenza virus A/PR8. The body weight losses were lower with the LG2055 administration after the PR8 virus infection. At 5 days after the infection, the virus titer was significantly decreased as was the amount of produced IL-6 in the lung tissue, the number of total cells in the bronchoalveolar lavage fluid was reduced by the LG2055 administration. The expression of the Mx1 and Oas1a genes, critical for the viral clearance in the lung tissues was increased by the pre-treatment with LG2055. These findings suggest that the LG2055 administration is effective for the protection against influenza A virus infection by the down-regulation of viral replication through the induction of antiviral genes expression.

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The aim of the present study was to explore the relationship between work environment and moral sensitivity among Japanese (n = 138) and Norwegian nurses (n = 71), and to compare the results from a sociocultural perspective using a descriptive-correlational design. Data were analyzed using descriptive and inferential statistics. The results point to a significant relationship between work environment and moral sensitivity for both groups of nurses. In comparison, the Japanese nurses were more focused on 'patient centered oriented care', reported 'work engagement', seeking 'meaning in difficult caring situations' and 'following rules'. In addition, they ranked the factor 'values in action of patient care' as significant and 'relation to superior and colleagues' and 'job stress and anxiety' ranked significant to 'moral conflicts'. The Norwegian nurses were more independent, which was correlated with moderate significance with 'job stress and anxiety'. A significant correlation was found between 'physical and mental symptoms' and 'moral conflicts' among Norwegian nurses.