Association of subcutaneous and visceral fat with circulating microRNAs in a middle-aged Japanese population

Abstract

Purpose It has been demonstrated that circulating microRNA profiles are affected by physiological conditions. Several studies have demonstrated that microRNAs play important roles in the regulation of adiposity. However, few have investigated the relationship between circulating microRNAs and obesity, which has become a major public health problem worldwide. This study investigated the association between circulating microRNAs and obesity in a Japanese population. Methods Obesity parameters, such as subcutaneous and visceral fat adipose tissue, body fat percentage, and body mass index were assessed in a cross-sectional sample of 526 participants who attended health examinations in Yakumo, Japan. In addition, five circulating microRNAs (miR-20a, -21, -27a, -103a, and -320), which are involved in adipocyte proliferation and differentiation, were quantified using real-time polymerase chain reaction amplification. Results We compared the circulating microRNA concentrations in a percentile greater than 75th (high) with below the value (low) of subcutaneous adipose tissue, visceral fat adipose tissue, body mass index, and per cent body fat. For visceral fat adipose tissue, significant decrease in miR-320 expression was observed in high group. Also, for body mass index, significant change of miR-20a, -27a, 103a, and 320 expression level was observed in high group. Multiple linear regression analysis demonstrated that circulating levels of some microRNA such as miR-27a were significantly associated with subcutaneous adipose tissue, visceral fat adipose tissue, and body mass index. Conclusions Our findings support the need for further studies to determine whether such changes are consistent across different populations and whether the identified microRNAs may represent novel biomarkers to predict the susceptibility and progression of obesity-related disorders.

Association of circulating miR-20a, miR-27a, and miR-126 with non-alcoholic fatty liver disease in general population

“…In the present study, the levels of serum miR-20a and miR-27a, which are associated with obesity, MetS, and T2DM 14,[22][23][24] , were found to be significantly lower in NAFLD subjects. It has been reported that NAFLD shows ectopic fat accumulation that is usually accompanied by decreased glycogen synthesis 40 .…”

“…We examined whether the levels of circulating miR-20a, miR-27a, and miR-126, which are known to be associated with obesity, MetS, and/or T2DM 14,[22][23][24][25][26][27][28] , were altered in NAFLD subjects. Serum miR-20a and miR-27a levels were significantly lower in NAFLD subjects than in normal subjects ( Fig.…”

“…To date, several studies have demonstrated that NAFLD may change circulating miRNA expression 14,15,33,34 . For example, NAFLD patients show the up-regulated expression of circulating miRNAs, such as miR-21, miR-34a, miR-122, and miR-451 7 .…”

“…In addition, miRNAs are stable within bodily fluids (particularly plasma and serum) in which ribonuclease (RNase) molecules exist given that miRNAs are covered with small particles, including exosomes, high-density lipoproteins, and Argonaute, which protect miRNAs from degradation by RNase 11 . Recently, it has been reported that circulating miRNAs are associated with several diseases 7,[12][13][14][15][16] . For example, we have reported that serum miR-21, miR-34a, miR-122 and miR-451 levels are elevated in middle-aged Japanese NAFLD patients and that the level of serum miR-122 is closely associated with the severity of liver steatosis in both male and female NAFLD patients 7 .…”

Associations of Circulating MicroRNAs (miR-17, miR-21, and miR-150) and Chronic Kidney Disease in a Japanese Population

“…Approximately 3,000 species of human miRNAs have been identified to date and regulate over 30% of all human transcripts. 1,2 Accumulated evidence has revealed that miRNAs are associated with various pathophysiological conditions 3 and the development of diseases, such as cancer, [4][5][6][7][8] cardiovascular disease (CVD), 9,10 diabetes, 11 liver disease, 12,13 kidney disease, 14 and autoimmune disease. 15,16 In addition, previous studies have demonstrated that miRNAs are highly stable in body fluids, such as serum 17 and urine, 18 because protein-bound or microvesicle-derived miRNAs in blood vessels are protected from degradation.…”