Obesity Associated Modulation of miRNA and Co-Regulated Target Transcripts in Human Adipose Tissue of Non-Diabetic Subjects

Zinc Improves Semen Parameters in High-Fat Diet-Induced Male Rats by Regulating the Expression of LncRNA in Testis Tissue

This study aimed to identify differentially expressed LncRNAs in testis tissue of male rats induced by high-fat diet and their changes after zinc supplementation, by constructing a high-fat feeding rat model, and then supplemented with zinc, and observed the expression of LncRNA in three groups of normal, high-fat fed, and zinc-intervened rats. Experimental studies show that the semen parameters of male rats with high-fat diet were decreased but recovered after zinc supplementation, and the related LncRNA also changed. Zinc may improve the high-fat diet-induced reduction of semen parameters by changing the expression of related LncRNA.

Expression pattern of miR-193a, miR122, miR155, miR-15a, and miR146a in peripheral blood mononuclear cells of children with obesity and their relation to some metabolic and inflammatory biomarkers

BACKGROUND

The widespread presence of childhood obesity has increased considerably over three decades. The present study was designed to investigate expression patterns of miR-146a, miR-155, miR-15a, miR-193a, and miR-122 in peripheral blood mononuclear cells (PBMCs) in children who are obese along with their association with metabolic and inflammatory biomarkers.

METHODS

Ninety test subjects were admitted. The profile of blood pressure, resting energy expenditure (REE), anthropometric measures, body composition, dietary intakes, physical activity levels, insulin, and lipid profile, fasting blood glucose (FBG), high-sensitivity C-reactive protein (hs-CRP), and pubertal stage have been measured. Total RNA (including small RNAs) was extracted from PBMCs. The expression levels of miRNAs were measured by stem-loop RT-qPCR.

RESULTS

The miR-155a expression level was significantly lower in obese children, children with high hs-CRP, and children with high-fat mass. Obese girls had significantly higher PBMC levels of miR-122. MiR-155a had a significant negative association with fasting insulin, HOMA-IR, and hs-CRP. There were significant positive associations between miR-193a and miR-122 expression levels and fasting insulin, HOMA-IR, and TG. MiR-15a was positively correlated with fasting insulin and HOMA-IR. Children with metabolic syndrome, insulin resistance, and high-fat mass had higher PBMC levels of miR-122 and miR-193a. Higher miR-193a and miR-122 levels were also detected in PBMCs of children with fast REE, compared to those with slow REE, and the subjects with high hs-CRP, respectively.

CONCLUSION

lower level of miR-155 expression in obese subjects and significant associations unfolds the need for more studies to detect the possible underlying mechanisms.

Evaluation of the promoter methylation status of hypoxia factor 3A and interleukin-6 genes and expression levels of mir-130b and mir-146b in childhood obesity

OBJECTIVE

Obesity, which causes many serious diseases, is increasing exponentially in childhood across the world. Epigenetic changes, as well as genetics, play an important role in the process of adipogenesis. Therefore, we aimed to examine the expression levels of obesity-related MicroRNA-130b and MicroRNA-146b and the methylation status of hypoxia factor 3A and interleukin-6 genes associated with obesity in children.

METHODS

This study was performed with 98 individuals (49 obese children and 49 controls) whose DNA was isolated from peripheral blood. Gene promoter methylations were analyzed by methylation-specific Polymerase chain reaction. In addition, expression levels of MicroRNAs were determined by quantitative real-time Polymerase chain reaction in 30 children (15 obese children and 15 controls).

RESULTS

Methylation status of interleukin-6 gene was 93.9% in obese children (n=46/49) and 100% (n=49/49) in control group (p>0.05). There was no methylation for hypoxia factor 3A gene (p>0.05). As a result of the study, there was no statistically significant difference in terms of methylation status for hypoxia factor 3A and interleukin-6 genes in the obese group compared to the control group. However, we found that expression levels of MicroRNA-130b (p<0.01) and MicroRNA-146b (p<0.001) were higher in the obese group.

CONCLUSIONS

Results support that MicroRNA-130b and MicroRNA-146b are potential biomarkers for the prevention and early diagnosis of obesity. This is the first study on childhood obesity in the Middle Black Sea region of Turkey. We believe that the results obtained by expanding the studies in our country and neighboring countries will be more decisive.

MicroRNA-148a-3p is a candidate mediator of increased bone marrow adiposity and bone loss following spinal cord injury

Spinal cord injury is often followed by osteoporosis characterized by rapid and severe bone loss. This leads to an increased risk of osteoporotic fracture in people with spinal cord injury, resulting in increased healthcare costs, morbidity, and mortality. Though it is common, the mechanisms underlying this osteoporosis are not completely understood and treatment options are limited. No biomarkers have been identified for predicting fracture risk. In this study, we sought to investigate microRNA mediated mechanisms relating to osteoporosis following spinal cord injury. We studied subjects with acute SCI (n=12), chronic SCI (n=18), and controls with no SCI (n=23). Plasma samples from all subjects underwent transcriptomic analysis to quantify microRNA expression, after which miR-148a-3p was selected for further study. We performed CT scans of the knee on all subjects with SCI and analyzed these scans to quantify bone marrow adipose tissue volume. MiR-148a-3p was upregulated in subjects with acute SCI vs chronic SCI, as well as in acute SCI vs no SCI. Subjects with chronic SCI had greater levels of marrow adiposity in the distal femoral diaphysis compared to subjects with acute SCI. MiR-148a-3p levels were negatively associated with distal femoral diaphysis marrow adiposity. A multivariable model showed that miR-148a-3p and BMI explained 24% of variation in marrow adiposity. A literature search revealed that miR-148a-3p has multiple bone and fat metabolism related targets. Our findings suggest that miR-148a-3p is a mediator of osteoporosis following spinal cord injury and a potential future therapeutic target.

Obesity, leptin, and deregulation of microRNA in lipid metabolisms: their contribution to breast cancer prognosis

Obesity and Metabolic Syndrome have been associated with cardiovascular, diabetes and cancer incidence. Obesity is a state of inflammation. There are cross-talks between adipocyte, adipokines, pro-inflammatory cytokines, insulin, leptin, and other growth factors to initiate signals for proliferation, anti-apoptosis, and angiogenesis. Those networks lead to cancer initiation, promotion, progression, and metastasis. Post menopause women with breast cancer commonly have overweight, obesity, and metabolic syndrome, which are previously reported as conditions to be associated with breast cancer prognosis. MicroRNAs (miRNAs), small non-coding RNA that regulate gene expression, are known to play important roles either in metabolic or carcinogenesis process in patients with breast cancer. Some miRNAs expressions are deregulated in persons either with obesity, breast cancer, or breast cancer with co-morbid obesity. This literature review aimed at reviewing recent publications on the role of obesity, leptin, and microRNA deregulation in adverse prognosis of breast cancer. Understanding the influence of deregulated miRNAs and their target genes in patients with breast cancer and obesity will direct more studies to explore the potential prognostic role of obesity in breast cancer from epigenetic points of view.

Association between circulating microRNAs 486, 146b and 15b and serum betatrophin levels in obese; type 2 diabetic and non-diabetic children

BACKGROUND

This study tested the association between serum levels of microRNA-486, -146b and -15b and betatrophin in normal and obese children with/without type 2 diabetes mellitus (T2DM).

METHODS

the study included 120 children; divided into three groups: G1 (50 healthy), G2 (35 obese) and G3 (35 obese with T2DM). The levels of microRNA-486, 146b and 15b and serum betatrophin were measured by their corresponding methods.

RESULTS

serum microRNA-486, -146b, -15b and betatrophin levels were significantly high in G3 followed by G2 then G1 (p = 0.002, > 0.001, > 0.001, and > 0.001, respectively). Especially in G3, these levels correlated positively with the BMI percentile (r = 0.44, 0.58, 0.38, and 0.46, p = 0.007, > 0.001, 0.021, and 0.005, respectively), serum glucose (r = 0.56, 0.49, 0.82, 0.60, and 0.42, p > 0.001, 0.003, > 0.001, and > 0.001, respectively) and HbA1c% (r = 0.56, 0.39, 0.66, and 0.42, p > 0.001, 0.019, > 0.001, and 0.032, respectively) while, showed negative correlations with correlated with serum insulin levels (r = - 0.37, - 0.42, - 0.58, and - 0.41, p = 0.021, 0.012, > 0.001 and 0.013, respectively) and with serum C-peptide levels (r = - 0.76, - 0.50, - 0.35 and - 0.42, p > 0.001, 0.002, 0.036 and 0.011, respectively). Serum betatrophin levels correlated positively with microRNA-486, -146b and -15b levels in G2 (r = 0.35, 0.80, and 0.67, p = 0.036, > 0.001, and,> 0.001, respectively), and in G3 (r = 0.57, 0.36, and 0.38, p > 0.001, 0.029 and, 0.023, respectively).

CONCLUSIONS

Circulating microRNA-486, 146b and 15b increase significantly in obese children with T2DM and these levels correlate positively with serum betatrophin levels. Further studies are required to test the role of targeting of these microRNAs and betatrophin in the timely management of obesity and/or T2DM in children.

MiR-148a promotes myocardial differentiation of human bone mesenchymal stromal cells via DNA methyltransferase 1 (DNMT1)

MicroRNAs have potential to modulate the differentiation of stem cells. In previous study, we found that miR-148a was up-regulated in myocardial differentiation of human bone mesenchymal stromal cells (hBMSCs) induced by 5'-azacytidine. However, the role of miR-148a in regulating this process still remains unclear. In this study, we investigated the function and molecular mechanism of miR-148a in myocardial differentiation of hBMSCs. We found that miR-148a was significantly increased while DNA methyltransferase 1 (DNMT1) was significantly decreased in myocardial differentiation of hBMSCs. Then, the dual luciferase reporter assays method indicated that DNMT1 was the direct target of miR-148a. In addition, we showed that up-regulation of miR-148a could enhance myocardial differentiation of hBMSCs, while down-regulation of miR-148a could inhibit myocardial differentiation process. Moreover, knockdown of DNMT1 could block the role of miR-148a in promoting myocardial differentiation of hBMSCs. Finally, MiR-148a acted on methylation level of GATA-4 and knockdown of DNMT1 could block this function. Therefore, our results indicate that miR-148a plays a vital role in regulating myocardial differentiation of hBMSCs by targeting DNMT1.

Change in circulating microRNA profile of obese children indicates future risk of adult diabetes

PURPOSE

Childhood obesity increases susceptibility to type 2 diabetes (T2D) in adults. Circulating microRNAs (miRNAs) in serum have been proposed as potential diagnostic biomarkers, and they may contribute to the progression toward T2D. Here, we investigated the possibility of predicting the future risk of adult T2D in obese children by using circulating miRNAs.

BASIC PROCEDURES

We performed miRNA high-throughput sequencing to screen relevant circulating miRNAs in obese children. The expression patterns of targeted miRNAs were further explored in obese children and adults with T2D. To investigate the underlying contributions of these miRNAs to the development of T2D, we detected the impacts of the candidate miRNAs on preadipocyte proliferation, insulin secretion by pancreatic β-cell, and glucose uptake by skeletal muscle cells.

MAIN FINDINGS

Three miRNAs (miR-486, miR-146b and miR-15b), whose expression in the circulation was most dramatically augmented in obese children and adult T2D patients, were selected for further investigation. Of these 3 miRNAs, miR-486 was implicated in accelerating preadipocyte proliferation and myotube glucose intolerance, miR-146b and miR-15b were engaged in the suppression of high concentration glucose-induced pancreatic insulin secretion, and they all contributed to the pathological processes of obesity and T2D.

PRINCIPAL CONCLUSIONS

Our results provide a better understanding of the role of circulating miRNAs, particularly miR-486, miR-146b and miR-15b, in predicting the future risk of T2D in obese children.

Energy Balance Modulation Impacts Epigenetic Reprogramming, ERα and ERβ Expression, and Mammary Tumor Development in MMTV-neu Transgenic Mice

The association between obesity and breast cancer risk and prognosis is well established in estrogen receptor (ER)-positive disease but less clear in HER2-positive disease. Here, we report preclinical evidence suggesting weight maintenance through calorie restriction (CR) may limit risk of HER2-positive breast cancer. In female MMTV-HER2/neu transgenic mice, we found that ERα and ERβ expression, mammary tumorigenesis, and survival are energy balance dependent in association with epigenetic reprogramming. Mice were randomized to receive a CR, overweight-inducing, or diet-induced obesity regimen (n = 27/group). Subsets of mice (n = 4/group/time point) were euthanized after 1, 3, and 5 months to characterize diet-dependent metabolic, transcriptional, and epigenetic perturbations. Remaining mice were followed up to 22 months. Relative to the overweight and diet-induced obesity regimens, CR decreased body weight, adiposity, and serum metabolic hormones as expected and also elicited an increase in mammary ERα and ERβ expression. Increased DNA methylation accompanied this pattern, particularly at CpG dinucleotides located within binding or flanking regions for the transcriptional regulator CCCTC-binding factor of ESR1 and ESR2, consistent with sustained transcriptional activation of ERα and ERβ. Mammary expression of the DNA methylation enzyme DNMT1 was stable in CR mice but increased over time in overweight and diet-induced obesity mice, suggesting CR obviates epigenetic alterations concurrent with chronic excess energy intake. In the survival study, CR elicited a significant suppression in spontaneous mammary tumorigenesis. Overall, our findings suggest a mechanistic rationale to prevent or reverse excess body weight as a strategy to reduce HER2-positive breast cancer risk. Cancer Res; 77(9); 2500-11. ©2017 AACR.

MiR-21a-5p suppresses bisphenol A-induced pre-adipocyte differentiation by targeting map2k3 through MKK3/p38/MAPK

Childhood obesity is a metabolic disease characterized by accumulation of excessive fat. Bisphenol A (BPA), a potential obesogen compound, possesses an estrogen mimetic activity and endocrine disruption effect. MicroRNA-21a-5p (miR-21a-5p) is reported to regulate the adipogenic differentiation. Our study showed that miR-21a-5p overexpression significantly decreased the red lipid droplets and triglyceride level in BPA-induced 3T3-L1 cells. BPA induced the mRNA and protein expression levels of PPARγ, C/EBPα and adiponectin, and the induction was inhibited by miR-21a-5p mimics transfection. MiR-21a-5p mimics inhibited the GR activity, GR phosphorylation (S220, S21a-5p2, and S234), and the activation of p38/MAPK pathway, which are elevated by BPA treatment in 3T3-L1 cells. MiR-21a-5p overexpression inhibited the protein level of MKK3, but not in the mRNA level. Luciferase activity assay showed that miR-21a-5p directly targeted map2k3 3'-UTR. MKK3 overexpression attenuated the effect of miR-21a-5p mimics transfection on 3T3-L1 differentiation. We also assessed the body weight, fat mass and the content of serum lipid in rats subcutaneous injected with BPA and miR-21a-5p mimics. MiR-21a-5p overexpression attenuated BPA-induced obesity in vivo. These findings suggested that miR-21a-5p inhibited BPA induced adipocyte differentiation by targeting map2k3 through MKK3/p38/MAPK in 3T3-L1 cells, providing a potential therapeutic strategy for BPA induced obesity.