BackgroundReactive oxygen species are important mediators exerting toxic effects on various organs during ischemia-reperfusion (IR) injury. We hypothesized that adipose-derived mesenchymal stem cells (ADMSCs) protect the kidney against oxidative stress and inflammatory stimuli in rat during renal IR injury.MethodsAdult male Sprague-Dawley (SD) rats (n = 24) were equally randomized into group 1 (sham control), group 2 (IR plus culture medium only), and group 3 (IR plus immediate intra-renal administration of 1.0 × 106 autologous ADMSCs, followed by intravenous ADMSCs at 6 h and 24 h after IR). The duration of ischemia was 1 h, followed by 72 hours of reperfusion before the animals were sacrificed.ResultsSerum creatinine and blood urea nitrogen levels and the degree of histological abnormalities were markedly lower in group 3 than in group 2 (all p < 0.03). The mRNA expressions of inflammatory, oxidative stress, and apoptotic biomarkers were lower, whereas the anti-inflammatory, anti-oxidative, and anti-apoptotic biomarkers were higher in group 3 than in group 2 (all p < 0.03). Immunofluorescent staining showed a higher number of CD31+, von Willebrand Factor+, and heme oxygenase (HO)-1+ cells in group 3 than in group 2 (all p < 0.05). Western blot showed notably higher NAD(P)H quinone oxidoreductase 1 and HO-1 activities, two indicators of anti-oxidative capacity, in group 3 than those in group 2 (all p < 0.04). Immunohistochemical staining showed higher glutathione peroxidase and glutathione reductase activities in group 3 than in group 2 (all p < 0.02)ConclusionADMSC therapy minimized kidney damage after IR injury through suppressing oxidative stress and inflammatory response.

Abstract-Obstructive sleep apnea, a syndrome leading to recurrent intermittent hypoxia (IH), has been associated previously with hypercholesterolemia, independent of underlying obesity. We examined the effects of experimentally induced IH on serum lipid levels and pathways of lipid metabolism in the absence and presence of obesity. Lean C57BL/6J mice and leptin-deficient obese C57BL/6J-Lep ob mice were exposed to IH for five days to determine changes in serum lipid profile, liver lipid content, and expression of key hepatic genes of lipid metabolism. In lean mice, exposure to IH increased fasting serum levels of total cholesterol, high-density lipoprotein (HDL) cholesterol, phospholipids (PLs), and triglycerides (TGs), as well as liver TG content. These changes were not observed in obese mice, which had hyperlipidemia and fatty liver at baseline. In lean mice, IH increased sterol regulatory element binding protein 1 (SREBP-1) levels in the liver, increased mRNA and protein levels of stearoyl-coenzyme A desaturase 1 (SCD-1), an important gene of TG and PL biosynthesis controlled by SREBP-1, and increased monounsaturated fatty acid content in serum, which indicated augmented SCD-1 activity. In addition, in lean mice, IH decreased protein levels of scavenger receptor B1, regulating uptake of cholesterol esters and HDL by the liver. We conclude that exposure to IH for five days increases serum cholesterol and PL levels, upregulates pathways of TG and PL biosynthesis, and inhibits pathways of cholesterol uptake in the liver in the lean state but does not exacerbate the pre-existing hyperlipidemia and metabolic disturbances in leptin-deficient obesity. Key Words: obstructive sleep apnea Ⅲ cholesterol homeostasis Ⅲ lipids Ⅲ hypoxia Ⅲ mouse Ⅲ gene expression O bstructive sleep apnea (SA) is the most common form of sleep-disordered breathing and is characterized by recurrent collapse of the upper airway during sleep, leading to periods of intermittent hypoxia (IH) and sleep fragmentation. 1 SA is present in 2% of women and 4% of men in the general US population, but it is more common in obese individuals. 2,3 SA is an independent risk factor for increased cardiovascular morbidity and mortality. 4 -7 It has been postulated that metabolic dysfunction in SA may provide an intermediate step linking IH and sleep disturbances to cardiovascular disease. Although several recent studies have focused on the effects of SA on dysregulating glucose and insulin metabolism, 2,8 -10 little information is available about the impact of SA on lipid metabolism. Abnormalities in lipid regulation that occur in response to SA may act to increase the cardiovascular risk in an already susceptible population. Although obesity is one of the risk factors for elevations in total cholesterol (TC) and low-density lipoprotein (LDL) cholesterol levels, 11 recent clinical studies indicate that SA may also contribute to hypercholesterolemia. [12][13][14][15] Thus, obesity and IH may interact to alter lipid metabolism in SA.Key steps of lipid metaboli...