Role of microRNAs on adipogenesis, chronic low-grade inflammation, and insulin resistance in obesity

The Gut Microbial Regulation of Epigenetic Modification from a Metabolic Perspective

Obesity is a global health challenge that has received increasing attention in contemporary research. The gut microbiota has been implicated in the development of obesity, primarily through its involvement in regulating various host metabolic processes. Recent research suggests that epigenetic modifications may serve as crucial pathways through which the gut microbiota and its metabolites contribute to the pathogenesis of obesity and other metabolic disorders. Hence, understanding the interplay between gut microbiota and epigenetic mechanisms is crucial for elucidating the impact of obesity on the host. This review primarily focuses on the understanding of the relationship between the gut microbiota and its metabolites with epigenetic mechanisms in several obesity-related pathogenic mechanisms, including energy dysregulation, metabolic inflammation, and maternal inheritance. These findings could serve as novel therapeutic targets for probiotics, prebiotics, and fecal microbiota transplantation tools in treating metabolic disruptions. It may also aid in developing therapeutic strategies that modulate the gut microbiota, thereby regulating the metabolic characteristics of obesity.

miRNAs as Interconnectors between Obesity and Cancer

Obesity and cancer are a concern of global interest. It is proven that obesity may trigger the development or progression of some types of cancer; however, the connection by non-coding RNAs has not been totally explored. In the present review, we discuss miRNAs and lncRNAs dysregulation involved in obesity and some cancers, shedding light on how these conditions may exacerbate one another through the dysregulation of ncRNAs. lncRNAs have been reported as regulating microRNAs. An in silico investigation of lncRNA and miRNA interplay is presented. Our investigation revealed 44 upregulated and 49 downregulated lncRNAs in obesity and cancer, respectively. miR-375, miR-494-3p, miR-1908, and miR-196 were found interacting with 1, 4, 4 and 4 lncRNAs, respectively, which are involved in PPARγ cell signaling regulation. Additionally, miR-130 was found to be downregulated in obesity and reported as modulating 5 lncRNAs controlling PPARγ cell signaling. Similarly, miR-128-3p and miR-143 were found to be downregulated in obesity and cancer, interacting with 5 and 4 lncRNAs, respectively, associated with MAPK cell signaling modulation. The delicate balance between miRNA and lncRNA expression emerges as a critical determinant in the development of obesity-associated cancers, presenting these molecules as promising biomarkers. However, additional and deeper studies are needed to reach solid conclusions about obesity and cancer connection by ncRNAs.

Treatment of obesity by acupuncture combined with medicine based on pathophysiological mechanism: A review

Obesity is a complex, multifactorial disease. The incidence of overweight and obesity has doubled worldwide since 1980, and nearly one-third of the world population is now classified as overweight or obese. Obesity rates are increasing in all age groups and for both sexes, regardless of geographic region, race, or socioeconomic status, although they are generally higher in older adults and women. Although the absolute prevalence of overweight and obesity varies widely, this trend is similar across different regions and countries. In some developed countries, the prevalence of obesity has levelled off over the past few years. However, obesity has become a health problem that cannot be ignored in low- and middle-income countries. Although the drug treatment model of modern medicine has a significant therapeutic effect in the treatment of obesity, its adverse effects are also obvious. Acupuncture combined with Chinese medicine treatment of obesity has prominent advantages in terms of clinical efficacy, and its clinical safety is higher, with fewer adverse reactions. The combination of acupuncture and medicine in the treatment of obesity is worth exploring.

Circulating MiRNAs Are Associated With Low-grade Systemic Inflammation and Leptin Levels in Older Adults

Inflammaging refers to the low-grade systemic inflammation that occurs with aging present in chronic non-communicable diseases. MicroRNAs (miRNAs) are potential biomarkers for these diseases in older adults. This study aimed to assess the expression of 21 circulating miRNAs and their associations with inflammatory biomarkers in older adults. This cross-sectional study was performed with 200 individuals participating in ISA-Nutrition. The systemic low-grade inflammation score (SIS) was calculated from the plasma concentration of 10 inflammatory biomarkers. Circulating miRNA expression was assessed using the Fluidigm method. Wilcoxon-Mann-Whitney test was employed to determine differences in SIS among groups distributed according to sex and presence of MetS. Spearman's correlation was used to estimate correlations among SIS, leptin levels, miRNA expression, and variables of interest. Analyses were performed using software R version 4.2.3, with a significance level of 0.05. The final sample consisted of 193 individuals with a mean age of 69.1 (SE = 0.5) years, being 64.7% individuals with metabolic syndrome (MetS). Positive correlations were observed between leptin concentration and metabolic risk factors, and leptin concentration was higher in individuals with MetS compared to those without MetS. The expression of 15 circulating miRNAs was negatively correlated with leptin concentration. GLMs showed negative associations between miRNAs (miR-15a, miR-16, miR-223, miR-363, miR-532), leptin, and/or SIS values; and only miR-21 showed positive association with SIS values. The results suggest the presence of peripheral leptin resistance associated with low-grade inflammation and plasma expression of miRNAs in older adults. These findings suggest the potential role of miRNAs as biomarkers for cardiometabolic risk.

A Review of micro RNAs changes in T2DM in animals and humans

Type 2 diabetes mellitus (T2DM) and its associated complications have become a crucial public health concern in the world. According to the literature, chronic inflammation and the progression of T2DM have a close relationship. Accumulated evidence suggests that inflammation enhances the insulin secretion lost by islets of Langerhans and the resistance of target tissues to insulin action, which are two critical features in T2DM development. Based on recently highlighted research that plasma concentration of inflammatory mediators such as tumor necrosis factor α and interleukin-6 are elevated in insulin-resistant and T2DM, and it raises novel question marks about the processes causing inflammation in both situations. Over the past few decades, microRNAs (miRNAs), a class of short, noncoding RNA molecules, have been discovered to be involved in the regulation of inflammation, insulin resistance, and T2DM pathology. These noncoding RNAs are specifically comprised of RNA-induced silencing complexes and regulate the expression of specific protein-coding genes through various mechanisms. There is extending evidence that describes the expression profile of a special class of miRNA molecules altered during T2DM development. These modifications can be observed as potential biomarkers for the diagnosis of T2DM and related diseases. In this review study, after reviewing the possible mechanisms involved in T2DM pathophysiology, we update recent information on the miRNA roles in T2DM, inflammation, and insulin resistance.

Insulin resistance and adverse lipid profile in untreated very early rheumatoid arthritis patients: A single-center, cross-sectional study in China

Objectives

This study aims to evaluate the presence and factors related to insulin resistance (IR) in untreated very early rheumatoid arthritis (RA) patients.

Patients and methods

Between June 2020 and July 2021, a total of 90 RA patients (29 males, 61 females; mean age: 49.3±10.2 years; range 24 to 68 years) and 90 age-, sex- and body mass index (BMI)-matched controls (35 males, 55 females; mean age: 48.3±5.1 years; range 38 to 62 years) were included. Homeostatic model assessment was applied to evaluate IR (HOMA-IR) and β-cell function (HOMA-β). Disease activity score 28 (DAS28) was used to estimate disease activity. Lipid profile, hemoglobin A1c (HbA1c), glucose, insulin, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) were measured. Logistic regression analysis was performed to investigate the relationship between the IR and clinical features of RA patients.

Results

The RA patients had higher HOMA-IR values (p<0.001) and adverse lipid profile. The IR was positively correlated with age (r=0.35, p<0.01), CRP (r=0.42, p<0.001), ESR (r=0.33, p<0.01), disease duration (r=0.28, p<0.01), and DAS28 (r=0.50, p<0.001). The DAS28, CRP and age, but not sex and menopausal status, were independently associated with IR.

Conclusion

Insulin resistance was present in untreated very early RA patients. The DAS28, CRP, and age were independent predictors for the presence of IR. Based on these findings, RA patients should be evaluated early for the presence of IR to reduce the risk of metabolic diseases.

Recent progress in epigenetics of obesity

Nowadays, obesity is one of the largest public health problems worldwide. In the last few decades, there has been a marked increase in the obesity epidemic and its related comorbidities. Worldwide, more than 2.2 billion people (33%) are affected by overweight or obesity (712 million, 10%) and its associated metabolic complications. Although a high heritability of obesity has been estimated, the genetic variants conducted from genetic association studies only partially explain the variation of body mass index. This has led to a growing interest in understanding the potential role of epigenetics as a key regulator of gene-environment interactions on the development of obesity and its associated complications. Rapid advances in epigenetic research methods and reduced costs of epigenome-wide association studies have led to a great expansion of population-based studies. The field of epigenetics and metabolic diseases such as obesity has advanced rapidly in a short period of time. The main epigenetic mechanisms include DNA methylation, histone modifications, microRNA (miRNA)-mediated regulation and so on. DNA methylation is the most investigated epigenetic mechanism. Preliminary evidence from animal and human studies supports the effect of epigenetics on obesity. Studies of epigenome-wide association studies and genome-wide histone modifications from different biological specimens such as blood samples (newborn, children, adolescent, youth, woman, man, twin, race, and meta-analysis), adipose tissues, skeletal muscle cells, placenta, and saliva have reported the differential expression status of multiple genes before and after obesity interventions and have identified multiple candidate genes and biological markers. These findings may improve the understanding of the complex etiology of obesity and its related comorbidities, and help to predict an individual's risk of obesity at a young age and open possibilities for introducing targeted prevention and treatment strategies.

Circulating microRNA Related to Cardiometabolic Risk Factors for Metabolic Syndrome: A Systematic Review

MicroRNA regulates multiple pathways in inflammatory response, adipogenesis, and glucose and lipid metabolism, which are involved in metabolic syndrome (MetS). Thus, this systematic review aimed at synthesizing the evidence on the relationships between circulating microRNA and risk factors for MetS. The systematic review was registered in the PROSPERO database (CRD42020168100) and included 24 case-control studies evaluating microRNA expression in serum/plasma of individuals ≥5 years old. Most of the studies focused on 13 microRNAs with higher frequency and there were robust connections between miR-146a and miR-122 with risk factors for MetS, based on average weighted degree. In addition, there was an association of miR-222 with adiposity, lipid metabolism, glycemic metabolism, and chronic inflammation and an association of miR-126, miR-221, and miR-423 with adiposity, lipid, and glycemic metabolism. A major part of circulating microRNA was upregulated in individuals with risk factors for MetS, showing correlations with glycemic and lipid markers and body adiposity. Circulating microRNA showed distinct expression profiles according to the clinical condition of individuals, being particularly linked with increased body fat. However, the exploration of factors associated with variations in microRNA expression was limited by the variety of microRNAs investigated by risk factor in diverse studies identified in this systematic review.

Novel Noninvasive Approaches to the Treatment of Obesity: From Pharmacotherapy to Gene Therapy

Recent insights into the pathophysiologic underlying mechanisms of obesity have led to the discovery of several promising drug targets and novel therapeutic strategies to address the global obesity epidemic and its comorbidities. Current pharmacologic options for obesity management are largely limited in number and of modest efficacy/safety profile. Therefore, the need for safe and more efficacious new agents is urgent. Drugs that are currently under investigation modulate targets across a broad range of systems and tissues, including the central nervous system, gastrointestinal hormones, adipose tissue, kidney, liver, and skeletal muscle. Beyond pharmacotherapeutics, other potential antiobesity strategies are being explored, including novel drug delivery systems, vaccines, modulation of the gut microbiome, and gene therapy. The present review summarizes the pathophysiology of energy homeostasis and highlights pathways being explored in the effort to develop novel antiobesity medications and interventions but does not cover devices and bariatric methods. Emerging pharmacologic agents and alternative approaches targeting these pathways and relevant research in both animals and humans are presented in detail. Special emphasis is given to treatment options at the end of the development pipeline and closer to the clinic (ie, compounds that have a higher chance to be added to our therapeutic armamentarium in the near future). Ultimately, advancements in our understanding of the pathophysiology and interindividual variation of obesity may lead to multimodal and personalized approaches to obesity treatment that will result in safe, effective, and sustainable weight loss until the root causes of the problem are identified and addressed.

Stress-induced miRNAs isolated from wheat have a unique therapeutic potential in ultraviolet-stressed human keratinocyte cells

Increasing evidence supports the existence of cross-kingdom gene regulation. However, the therapeutic potential of stress-specific plant miRNAs and their role in UV-related pathologies in human tissue remain largely unexplored. The aim of this study was to investigate the therapeutic potential and mechanisms of action of stress-induced miRNA cocktails (SI-WmiRs) from Einkorn wheat (Triticum monococcum L.) on human keratinocyte (HaCaT) cells exposed to a high dose of UV-B radiation. We used a biofactory approach and irradiated wheatgrass with UV-C for 240 min to obtain the specific SI-WmiRs that wheat produces to recover from UV stress. We followed the plant with molecular and biochemical analyses and extracted our SI-WmiRs at the most appropriate time (0 h and 6 h after UV-C application). Then, we applied the SI-WmiR cocktail to HaCaT cells exposed to high-dose of UV-B radiation. Our results show that UV-B radiation induced lipid peroxidation and DNA damage, as demonstrated by increased malondialdehyde (MDA) levels and changes in the RAPD band profile, respectively. UV stress also impaired IL6/JAK2/STAT3 signalling and activated the inflammatory mediators IL6 and TNF-α in HaCaT cells, leading to significant induction of apoptotic cell death. We found that SI-WmiR transfection prevents lipid peroxidation and oxidative stress-related DNA damage by increasing antioxidant (CuZn-SOD, Mn-SOD) and DNA repair (EXO1, SMUG1 and XRCC3) gene expression. In addition, SI-WmiRs regulated IL6/JAK2/STAT3 signalling by reducing JAK2 and STAT3 gene expression and phosphorylated protein levels compared to the control treatments. Moreover, SI-WmiRs inhibited pro-apoptotic BAX, Caspase 3 and Caspase 8 gene expression and protein levels to prevent apoptosis of UV-stressed HaCaT cells. Our results demonstrate that stress-induced wheat miRNAs produced using a biofactory approach have strong potential as a novel and effective alternative therapy for UV stress-related skin damage.

Association between obesity grade and the age of the first acute coronary syndrome: A cross-sectional observational study

BACKGROUND

The study evaluates how obesity grade is associated with age during the first acute coronary syndrome (ACS) and examines the effect of cardiovascular (CV) risk factors and the age of first ACS in patients with severe obesity.

METHODS

We enrolled consecutive patients diagnosed with first episode of ACS between 2014 and 2019, and categorized them by body mass indices (BMI). Severe obesity was defined as BMI ≥35 kg/m². Independent variables affecting the age of first ACS were examined by linear regression analysis.

RESULTS

A total of 1005 patients (mean age, 57.5 ± 12.3 years; 19.3% female) were included. Approximately 6% and 12% of obese patients and normal weight patients had no other risk factors. Patients with ACS with severe obesity were younger than those with ACS in the grade-I obesity, overweight, and normal-weight groups (52.8 ± 9.9 vs. 55.3 ± 10.9, 56.8 ± 11.4, and 61.4 ± 14.2, respectively, p < 0.001). BMI had a strong, inverse linear relationship with earlier age of first ACS. The number of patients with no risk factors was significantly high in normal-weight individuals compared with patients with severe obesity (11.6% vs 5.6%, p = 0.037). After adjusting for CV risk factors, patients with overweight, grade-I obesity, and severe obesity may experience first ACS sooner than those with normal-weight by 3.9, 6.1, and 7.7 years, respectively (p < 0.001). However, males and females with severe obesity without CV risk factors experienced the first ACS episode 16 and 22 years later than those with the highest number of risk factors, respectively.

CONCLUSION

Patients with severe obesity experience first ACS episode 7.7 years earlier than those with normal-weight. Absence of CV risk factors in people with obesity can improve the potential negative effect of obesity on the ACS age.

TRIAL REGISTRATION

NCT04578964, 08 October 2020.

Interleukin-1β in Multifactorial Hypertension: Inflammation, Vascular Smooth Muscle Cell and Extracellular Matrix Remodeling, and Non-Coding RNA Regulation

The biological activities of interleukins, a group of circulating cytokines, are linked to the immuno-pathways involved in many diseases. Mounting evidence suggests that interleukin-1β (IL-1β) plays a significant role in the pathogenesis of various types of hypertension. In this review, we summarized recent findings linking IL-1β to systemic arterial hypertension, pulmonary hypertension, and gestational hypertension. We also outlined the new progress in elucidating the potential mechanisms of IL-1β in hypertension, focusing on it's regulation in inflammation, vascular smooth muscle cell function, and extracellular remodeling. In addition, we reviewed recent studies that highlight novel findings examining the function of non-coding RNAs in regulating the activity of IL-1β and its associated proteins in the setting of hypertension. The information collected in this review provides new insights into understanding the pathogenesis of hypertension and could lead to the discovery of new anti-hypertensive therapies to combat this highly prevalent disease.

Obesity: Epidemiology, Pathophysiology, and Therapeutics

Obesity is a complex multifactorial disease that accumulated excess body fat leads to negative effects on health. Obesity continues to accelerate resulting in an unprecedented epidemic that shows no significant signs of slowing down any time soon. Raised body mass index (BMI) is a risk factor for noncommunicable diseases such as diabetes, cardiovascular diseases, and musculoskeletal disorders, resulting in dramatic decrease of life quality and expectancy. The main cause of obesity is long-term energy imbalance between consumed calories and expended calories. Here, we explore the biological mechanisms of obesity with the aim of providing actionable treatment strategies to achieve a healthy body weight from nature to nurture. This review summarizes the global trends in obesity with a special focus on the pathogenesis of obesity from genetic factors to epigenetic factors, from social environmental factors to microenvironment factors. Against this background, we discuss several possible intervention strategies to minimize BMI.

Aging, MicroRNAs, and Heart Failure

Aging is a major risk factor for heart failure, one of the leading causes of death in Western society. The mechanisms that underlie the different forms of heart failure have been elucidated only in part and the role of noncoding RNAs is still poorly characterized. Specifically, microRNAs (miRNAs), a class of small noncoding RNAs that can modulate gene expression at the posttranscriptional level in all cells, including myocardial and vascular cells, have been shown to play a role in heart failure with reduced ejection fraction. In contrast, miRNAs role in heart failure with preserved ejection fraction, the predominant form of heart failure in the elderly, is still unknown. In this review, we will focus on age-dependent miRNAs in heart failure and on some other conditions that are prevalent in the elderly and are frequently associated with heart failure with preserved ejection fraction.

High expression levels of circulating microRNA-122 and microRNA-222 are associated with obesity in children with Mayan ethnicity

OBJECTIVES

High expression levels (HELs) of microRNA-122 (miR-122) or microRNA-222 (miR-222) have been associated with insulin resistance (IR), which leads to the development of obesity. The association between HELs of circulating miR-122 and miR-222 and the risk of obesity was evaluated in Mexican school-aged children, where childhood obesity is the primary cause of morbidity.

METHODS

Anthropometric data, biochemical parameters, and caloric intake were obtained in 50 children with obesity and 49 children with normal weight. The expression of circulating miR-122 and miR-222 was measured by quantitative real-time polymerase chain reaction amplification. Data were analyzed using Student t test, Pearson correlation coefficient, associations with chi-square, and multiple linear and logistic regressions with SPSS software v.23.

RESULTS

The mean relative expression for miR-122 and miR-222 was 0.33 and 5.65, respectively, for children with obesity and 0.22 and 3.16, respectively, for children with normal weight. The expression of miR-122 and miR-222 was 1.47 and 1.78-fold higher, respectively, in children with obesity (P = 0.001 and P = 0.025). HELs of both miR-122 and miR-222 were associated with body mass index (BMI), waist to height ratio (WHR), fat percentage, serum high-density lipid levels, triglycerides (TGs), and metabolic index (MI) (P < .001).

CONCLUSIONS

The HELs of circulating miR-122 conferred a 3.85-fold increase in the risk for obesity, whereas the HELs of both miR-122 and miR-222 conferred a 3.11-fold increase in the risk for obesity, which were also associated with higher anthropometric or biochemical parameters, such as BMI, WHR, fat percentage, serum high-density lipid levels, TGs, and MI, in Mayan children.

miR-100-3p inhibits the adipogenic differentiation of hMSCs by targeting PIK3R1 via the PI3K/AKT signaling pathway

MicroRNAs play an important role in the adipogenic differentiation of human bone marrow mesenchymal stem cells (hMSCs). How miR-100-3p influences such adipogenesis, however, remains uncertain. In this study, hMSC adipogenic differentiation was associated with miR-100-3p downregulation, and overexpressing this miRNA inhibited adipogenesis and the expression of adipogenic marker genes. Through bioinformatics approaches, miR-100-3p can bind the 3'-untranslated region (3'-UTR) of the mRNA encoding phosphoinositide 3-kinase regulatory subunit 1 (PIK3R1) such that miR-100-3p overexpression resulted in significant reductions in PIK3R1 expression. Importantly, overexpressing PIK3R1 was sufficient to reverse the anti-adipogenic effects of miR-100-3p overexpression. PIK3R1 is a critical component of the PI3K/AKT signaling pathway, and miR-100-3p overexpression resulted in reduced AKT phosphorylation in the context of adipogenesis. In addition, the adipogenic differentiation of hMSCs in which miR-100-3p was overexpressed was further enhanced upon treatment with the PI3K/AKT agonist 740Y-P relative to miR-100-3p overexpression alone. Taken together, these findings provide evidence that miR-100-3p inhibits the adipogenic differentiation of hMSCs by targeting PIK3R1 via the PI3K/AKT signaling pathway.

UCP2, IL18, and miR-133a-3p are dysregulated in subcutaneous adipose tissue of patients with obesity

The aim of this study was to compare the expression of UCP2, NLRP3, IL1B, IL18, and miR-133a-3p in subcutaneous adipose tissue (SAT) of 61 patients divided according to BMI: Group 1 (n = 8; BMI<25.0 kg/m²), Group 2 (n = 24; BMI 30.0-39.9 kg/m²), and Group 3 (n = 29; BMI≥40.0 kg/m²). SAT biopsies were obtained from individuals who underwent bariatric surgery or elective abdominal surgery. Gene expressions were quantified using qPCR. Bioinformatics analyses were employed to investigate target genes and pathways related to miR-133a-3p. UCP2 and miR-133a-3p expressions were decreased in SAT of Groups 2 and 3 while IL18 was increased compared to Group 1. NLRP3 and IL1B expressions did not differ between groups; however, NLRP3 was positively correlated with waist circumference and excess weight. Bioinformatics analysis demonstrated that UCP2 and NLRP3 are targets of miR-133a-3p. In conclusion, UCP2 and miR-133a-3p expressions are downregulated in patients with obesity, while IL18 is upregulated. NRLP3 is correlated with waist circumference and weight excess.

miR-324-5p promotes adipocyte differentiation and lipid droplet accumulation by targeting Krueppel-like factor 3 (KLF3)

miRNAs, a kind of noncoding small RNA, play a significant role in adipose differentiation. In this study, we explored the effect of miR-324-5p in adipose differentiation, and found that miR-324-5p could promote adipocytes differentiation and increase body weight in mice. We overexpressed miR-324-5p during adipocytes differentiation, by oil red O and bodipy staining found that lipid accumulation was increased, and the expression level of adipogenic related genes were significantly increased. And the opposite experimental results were obtained after inhibiting miR-324-5p. In vivo, we injected miR-324-5p agomiR in obese mice and found that body weight, adipocyte area, and adipogenic-related gene expression level were significantly increased but lipolytic genes were decreased. To further explore the mechanism of miR-324-5p regulation in lipid accumulation, we constructed Krueppel-like factor 3 (KLF3) 3'-untranslated region luciferase reporter vector and KLF3 pcDNA 3.1 overexpression vector, and found that miR-324-5p was able to directly target KLF3. Overall, in this study we found that miR-324-5p could promote mice preadipoytes differentiation and increase mice fat accumulation by targeting KLF3.

Nutritional genomics, inflammation and obesity

The Human Genome Project has significantly broadened our understanding of the molecular aspects regulating the homeostasis and the pathophysiology of different clinical conditions. Consequently, the field of nutrition has been strongly influenced by such improvements in knowledge - especially for determining how nutrients act at the molecular level in different conditions, such as obesity, type 2 diabetes, cardiovascular disease, and cancer. In this manner, characterizing how the genome influences the diet and vice-versa provides insights about the molecular mechanisms involved in chronic inflammation-related diseases. Therefore, the present review aims to discuss the potential application of Nutritional Genomics to modulate obesity-related inflammatory responses. Arch Endocrinol Metab. 2020;64(3):205-22.

Genistein inhibits high fat diet-induced obesity through miR-222 by targeting BTG2 and adipor1

Obesity and diabetes mellitus have become major health problems worldwide. In recent years, genistein has been found to be capable of inhibiting obesity and alleviating insulin resistance. However, the molecular mechanism of genistein against obesity is still not fully understood. In this study, we used 3T3-L1 preadipocytes and obese mice as models to explore the molecular mechanism of genistein against obesity. We found that genistein can inhibit obesity and downregulate the expression of miR-222 in mouse adipose tissue. In 3T3-L1 preadipocytes, treatment with miR-222 inhibitor or genistein reduced the expression of miR-222 and promoted lipid decomposition, while miR-222 treatment increased the expression of miR-222 and inhibited lipolysis. Moreover, the dual-luciferase reporter assay system confirmed that BTG2 and adipor1 are the target genes of miR-222. Experiments conducted in vitro and in vivo suggest that genistein may regulate lipid metabolism in the adipose tissue of obese mice by regulating the expression of miR-222 and its target genes, BTG2 and adipor1. Our findings provide a new epigenetic mechanism underpinning the ability of genistein to resist obesity. These results may provide a reference point for the dietary treatment of obesity and type 2 diabetes mellitus.

Circulating microRNAs in human obesity: a systematic review

Context: Differential expression profiles of microRNAs have been reported in human obesity suggesting a miRNAs role in the development of obesity and associated disorders. Objective: To review circulating microRNAs (c-miRNAs) dysregulated in human obesity and to predict their possible target genes. Methods: We performed a systematic review on PubMed database (PROSPERO, CRD42017077742) for original works on c-miRNAs and human obesity and recorded c-miRNAs with differential expression profiles. Potential target genes and metabolic pathways for dysregulated miRNAs with at least two independent reports were searched using bioinformatic tools. Results: Twenty-two c-miRNAs are overexpressed, nine underexpressed and two c-miRNAs dysregulated in both directions in people with obesity compared to lean controls. Bioinformatic analyses suggest these c-miRNAs target on genes associated with fatty acid metabolism and PI3k/Akt pathway. Conclusion: Literature records 33 c-miRNAs confirmedly dysregulated in human obesity. Their predicted target genes are involved in pathways that could explain the development of obesity and its comorbidities. Further research will clarify the role of these miRNAs on metabolic diseases and their usefulness for the prognosis, prevention and treatment of obesity.

Dietary plant miRNAs as an augmented therapy: cross-kingdom gene regulation

Cross-kingdom gene regulation by microRNAs (miRNAs) initiated a hot debate on the effective role of orally acquired plant miRNAs on human gene expression. It resulted in the expansion of gene regulation theories and role of plant miRNAs in cross-kingdom regulation of gene expression. This opened up the discussion that 'Whether we really get what we eat?' and 'Whether the orally acquired miRNAs really have a biologically important consequences after entering our digestive and circulatory system?' The reports of orally acquired plant miRNAs inside human alimentary canal have been a topic of discussion in the scientific community. The cross-kingdom gene regulations have raised our hopes to explore the exciting world of plant miRNAs as therapeutic potential and dietary supplements. However, there are reports which have raised concerns over any such cross-kingdom regulation and argued that technical flaws in the experiments might have led to such hypothesis. This review will give the complete understanding of exogenous application and cross-kingdom regulation of plant miRNAs on human health. Here, we provide update and discuss the consequences of plant miRNA mediated cross-kingdom gene regulation and possibilities for this exciting regulatory mechanism as an augmented therapy against various diseases.

Quantum Dot Based Nano-Biosensors for Detection of Circulating Cell Free miRNAs in Lung Carcinogenesis: From Biology to Clinical Translation

Lung cancer is the most frequently occurring malignancy and the leading cause of cancer-related death for men in our country. The only recommended screening method is clinic based low-dose computed tomography (also called a low-dose CT scan, or LDCT). However, the effect of LDCT on overall mortality observed in lung cancer patients is not statistically significant. Over-diagnosis, excessive cost, risks associated with radiation exposure, false positive results and delay in the commencement of the treatment procedure questions the use of LDCT as a reliable technique for population-based screening. Therefore, identification of minimal-invasive biomarkers able to detect malignancies at an early stage might be useful to reduce the disease burden. Circulating nucleic acids are emerging as important source of information for several chronic pathologies including lung cancer. Of these, circulating cell free miRNAs are reported to be closely associated with the clinical outcome of lung cancer patients. Smaller size, sequence homology between species, low concentration and stability are some of the major challenges involved in characterization and specific detection of miRNAs. To circumvent these problems, synthesis of a quantum dot based nano-biosensor might assist in sensitive, specific and cost-effective detection of differentially regulated miRNAs. The wide excitation and narrow emission spectra of these nanoparticles result in excellent fluorescent quantum yields with a broader color spectrum which make them ideal bio-entities for fluorescence resonance energy transfer (FRET) based detection for sequential or simultaneous study of multiple targets. In addition, photo-resistance and higher stability of these nanoparticles allows extensive exposure and offer state-of-the art sensitivity for miRNA targeting. A major obstacle for integrating QDs into clinical application is the QD-associated toxicity. However, the use of non-toxic shells along with surface modification not only overcomes the toxicity issues, but also increases the ability of QDs to quickly detect circulating cell free miRNAs in a non-invasive mode. The present review illustrates the importance of circulating miRNAs in lung cancer diagnosis and highlights the translational prospects of developing QD-based nano-biosensor for rapid early disease detection.

Follistatin-Like 1 Is Downregulated in Morbidly and Super Obese Central-European Population

Follistatin-like 1 (FSTL1) is a secreted adipomyokine with a possible link to obesity; however, its connection to extreme obesity currently remains unknown. In order to analyze such association for the very first time, we employed a unique cohort of morbidly and super obese individuals with a mean BMI of 44.77 kg/m² and measured the levels of circulating FSTL1. We explored the 3′ UTR of FSTL1 to locate a genetic variant which impairs microRNA binding. We located and investigated such SNP (rs1057231) in relation to the FSTL1 protein level, obesity status, and other body composition parameters. We observed a significant decline in FSTL1 level in obese subjects in comparison to nonobese ones. The evaluated SNP was found to correlate with FSTL1 only in nonobese subjects. The presented results were not affected by sex since both males and females expressed FSTL1 equally. We suggest that the FSTL1 decrease observed in extremely obese subjects is a result of adipogenesis reduction accompanied by a senescence of preadipocytes which otherwise willingly express FSTL1, increased adipocyte apoptosis, and epigenetic FSTL1 silencing.

The type of dietary fat and dietary energy restriction affects the activity of the desaturases in the liver microsomes

The aim of present study was to investigate the effect of different dietary oils and the dietary energy restriction on the activity of enzymes participating in the process of arachidonic acid synthesis and on fatty acid profile in serum. It was also evaluated how diet modification affects the weight of animals and weight of the specific organs: liver, kidney and spleen. Wistar male rats were divided into 6 groups according to the diet fed (control, sunflower oil, olive oil, rapeseed oil, fish oil and a group of dietary energy restriction - DER group). The enzyme activities were established indirectly in liver microsomes. To this aim the method of high performance liquid chromatography with UV/VIS detection was used. In addition, the indices of ∆⁶-desaturase (D6D) and ∆⁵-desaturase (D5D) were determined. Significant differences in the concentrations of fatty acids and enzyme activity were observed. The results concerning desaturases show the negative correlation between n-3 polyunsaturated fatty acids intake and enzymes activity. The highest D6D activity was observed in microsomes obtained from sunflower oil fed rats and the lowest D6D activity was in the DER group. D5D index did not differ much depending on the diet. Among groups supplemented with oils the higher mean values of the weight of liver were observed in the group supplemented with rapeseed oil. Consumption of diets supplemented with edible oils of different fatty acid profile influence both serum fatty acid composition and the activity of ∆⁶- and Δ⁵-desaturase.

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

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.

Nutrimiromics: Role of microRNAs and Nutrition in Modulating Inflammation and Chronic Diseases

Nutrimiromics studies the influence of the diet on the modification of gene expression due to epigenetic processes related to microRNAs (miRNAs), which may affect the risk for the development of chronic diseases. miRNAs are a class of non-coding endogenous RNA molecules that are usually involved in post-transcriptional gene silencing by inducing mRNA degradation or translational repression by binding to a target messenger RNA. They can be controlled by environmental and dietary factors, particularly by isolated nutrients or bioactive compounds, indicating that diet manipulation may hold promise as a therapeutic approach in modulating the risk of chronic diseases. This review summarizes the evidence regarding the influence of nutrients and bioactive compounds on the expression of miRNAs related to inflammation and chronic disease in several models (cell culture, animal models, and human trials).

MicroRNA-130b attenuates dexamethasone-induced increase of lipid accumulation in porcine preadipocytes by suppressing PPAR-γ expression

In this study, two experiments were conducted to determine the role of miR-130b in dexamethasone (DEX)-induced lipid accumulation. Porcine preadipocytes were treated with 10⁻⁶ M DEX for 48 h to investigate effects of DEX in lipid accumulation. Next, in order to illustrate the regulatory role of miR-130b on lipid accumulation induced by DEX, miRNA scrambled control (miR-SC), miR-130b overexpression plasmid and miR-130b inhibitor were respectively transfected into porcine preadipocytes at 24 h before DEX treatment for 48 h (miR-SC-DEX, miR-130b-DEX and miR-130b-inhibitor-DEX). Results showed that 10⁻⁶ M DEX significantly increased TG concentration and expression of miR-130b as well as its target gene peroxisome proliferator-activated receptor-γ (PPAR-γ). Dual-luciferase reporter assays indicated that PPAR-γ expression was negatively regulated by miR-130b, while this effect was abolished with cotransfection of miR-130b and miR-130b inhibitor. In addition, miR-130b-DEX did not change cell proliferation but significantly decreased TG concentration and PPAR-γ expression compared to miR-SC-DEX cells, while miR-130b-inhibitor-DEX cells presented opposite results. Furthermore, miR-130b-DEX significantly reduced expression of PPAR-γ downstream factor perilipin 1 as well as adipogenesis genes fatty acid synthase, acetyl coenzyme A carboxylase, 11β hydroxysteroid dehydrogenase type 1 and fat mass and obesity-associated gene, whereas expression as well as enzyme activity of adipose triglyceride lipase and hormone-sensitive lipase were greatly increased. Overall, these results clarified the role of miR-130b in DEX-induced increase of lipid accumulation in porcine preadipocytes, suggesting that miR-130b might be deemed as a novel potential therapeutic target for DEX-induced increase of lipid accumulation, and consequently provide new insights in obesity control.