miRNA Profiles of Tubular Cells: Diagnosis of Kidney Injury

MicroRNAs (miRNAs) are small noncoding RNAs of 18–23 nucleotides that regulate gene expression. Recently, plasma miRNAs have been investigated as biomarkers for various physiological and pathological conditions. The present study details the conserved miRNA expression profiles of tubular tissues, and discusses whether they could be used to distinguish between proximal tubule injury, diagnose acute kidney injury (AKI), and the early-stage renal tubular dysfunction. miRNA expression was assessed with miRNA array and real-time reverse transcription polymerase chain reaction using the TaqMan system. The expression profiles of miR-200a/b/c, miR-145, miR-192, miR-194, miR-216a/b, miR-217, and miR-449a in human and rat tubular tissues such as the kidneys, lung, small intestine, and various exocrine glands were adequate for discriminating tubular tissues. In the kidney, miR-192 and miR-194 were highly expressed, whereas miR-145 and miR-449a were absent. miR-145 and miR-449a were relatively specifically expressed in small intestine and lung, respectively. Therefore, the combined levels of miR-200a/b/c, miR-192, and miR-194 in plasma were very useful in diagnosing AKI induced by contact freezing in mice. Moreover, urinary miR-200a levels were useful for the diagnosis of renal tubular dysfunction in Dahl salt-sensitive rat with high salt administration. Our results indicate that miRNA expression profiles are useful as biomarkers for identification of various kidney injuries

Oral administration of the β-glucan produced by Aureobasidium pullulans ameliorates development of atherosclerosis in apolipoprotein E deficient mice

The Aureobasidium pullulans-produced β-glucan (AP-PG) is an immune stimulator, and believed to exhibit beneficial effects on health through its immune stimulating activity. Here, the effect of oral administration of AP-PG on high-fat diet (HFD)-induced atherosclerosis was evaluated using apolipoprotein E deficient mice, a widely used mouse model for atherosclerosis. The results demonstrated that HFD-induced development of atherosclerosis was significantly reduced in the AP-PG-treated mice when compared with that of the control mice. In serological analysis, blood levels of oxidized low-density lipoprotein cholesterol, a well-known risk factor for the development of atherosclerosis, were significantly reduced in the AP-PG-treated group of mice. Further, immunohistochemical analysis using MOMA-2 antibody showed that oral administration of AP-PG is effective in ameliorating vascular accumulation of macrophages. These data suggest the possibility that oral administration of AP-PG is effective in ameliorating HFD-induced development of atherosclerosis

Oral administration of the Aureobasidium pullulans-derived β-glucan effectively prevents the development of high fat diet-induced fatty liver in mice

Aureobasidium pullulans-derived β-glucan (AP-PG) consisting of a β-(1,3)-linked glucose main chain and β-(1,6)-linked glucose branches is taken as a supplement to improve health. This study demonstrates that oral administration of AP-PG is effective to prevent the development of high-fat diet (HFD)-induced fatty liver in mice. Here, C57BL/6N mice were fed with a normal diet or HFD, and AP-PG diluted in drinking water was administered orally. After 16 weeks, the serological analysis showed that HFD-induced high blood cholesterol and triglyceride levels were reduced by the oral administration of AP-PG. Further, HFD induced-fatty liver was significantly reduced by the oral administration of AP-PG. The triglyceride accumulation in the liver was also significantly reduced in mice administered AP-PG. Liver injury as indicated by an increase in serum alanine aminotransferase (ALT) in the HFD-fed mice was significantly reduced in the mice administered AP-PG orally, and the gene expression of cholesterol 7 alpha-hydroxylase (CYP7A1) which is known to be involved in cholesterol degradation in the liver was significantly increased in the AP-PG administered mice. These results suggest the possibility that the oral administration of AP-PG is effective to prevent the development of non-alcoholic fatty liver disease (NAFLD)

Interleukin-17A Deficiency Accelerates Unstable Atherosclerotic Plaque Formation in Apolipoprotein E-Deficient Mice

Objective: Interleukin-17A (IL-17A), an inflammatory cytokine, has been implicated in atherosclerosis, in which inflammatory cells within atherosclerotic plaques express IL-17A. However, its role in the development of atheroscelrosis remains to be controversial. Methods and Results: To directly examine the role of IL-17A in atherosclerosis, we generated apolipoprotein E (ApoE)/IL-17A double-deficient (ApoE^[-/-]IL-17A^[-/-]) mice. Mice were fed with high-fat diet (HFD) for either 8 or 16 weeks, both starting at ages of 6-8 weeks. We found that splenic CD4+ T cells produced high amounts of IL-17A in ApoE^[-/-] mice after HFD feeding for 8 weeks. Atherosclerosis was significantly accelerated in HFD-fed ApoE^[-/-]IL-17A^[-/-] mice compared with ApoE^[-/-] mice. Splenic CD4+ T-cells of ApoE^[-/-]IL-17A^[-/-] mice after HFD feeding for 8 weeks, but not for 16 weeks, exhibited increased IFN-γ and decreased IL-5 production. Importantly, formation of vulnerable plaque as evidenced by reduced numbers of vascular smooth muscle cells and reduced type I collagen deposition in the plaque was detected in ApoE^[-/-]IL-17A^[-/-] mice after HFD feeding for 8 weeks. Conclusions: These results suggest that IL-17A regulates the early phase of atherosclerosis development after HFD feeding and plaque stability, at least partly if not all by modulating IFN-γ and IL-5 production from CD4+ T-cells

Establishment of the MethyLight Assay for Assessing Aging, Cigarette Smoking, and Alcohol Consumption

The environmental factors such as aging, smoking, and alcohol consumption have been reported to influence DNA methylation (DNAm). However, the versatility of DNAm measurement by DNAm array systems is low in clinical use. Thus, we developed the MethyLight assay as a simple method to measure DNAm. In the present study, we isolated peripheral blood DNA from 33 healthy volunteers and selected cg25809905, cg02228185, and cg17861230 as aging, cg23576855 as smoking, and cg02583484 as alcohol consumption biomarkers. The predicted age by methylation rates of cg25809905 and cg17861230 significantly correlated with chronological age. In immortalized B-cells, DNAm rates of two sites showed a younger status than the chronological age of donor. On the other hand, the predicted age of the patients with myocardial infarction (MI) was not accelerated. The methylation rate of cg23576855 was able to discriminate the groups based on the smoking status. The DNAm rate of cg02583484 was reduced in subjects with habitual alcohol consumption compared to that of subjects without habitual alcohol consumption. In conclusion, our MethyLight assay system reconfirms that aging, smoking, and alcohol consumption influenced DNAm in peripheral blood in the Japanese. This MethyLight system will facilitate DNAm measurement in epidemiological and clinical studies