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1.
Int J Mol Sci ; 24(10)2023 May 13.
Article in English | MEDLINE | ID: mdl-37240054

ABSTRACT

Uncoupling protein 1 (UCP1) plays a central role in thermogenic tissues by uncoupling cellular respiration to dissipate energy. Beige adipocytes, an inducible form of thermogenic cells in subcutaneous adipose tissue (SAT), have become a major focus in obesity research. We have previously shown that eicosapentaenoic acid (EPA) ameliorated high-fat diet (HFD)-induced obesity by activating brown fat in C57BL/6J (B6) mice at thermoneutrality (30 °C), independently of UCP1. Here, we investigated whether ambient temperature (22 °C) impacts EPA effects on SAT browning in wild-type (WT) and UCP1 knockout (KO) male mice and dissected underlying mechanisms using a cell model. We observed resistance to diet-induced obesity in UCP1 KO mice fed HFD at ambient temperature, with significantly higher expression of UCP1-independent thermogenic markers, compared to WT mice. These markers included the fibroblast growth factor 21 (FGF21) and sarco/endoplasmic reticulum Ca2+-ATPase 2b (SERCA2b), suggesting the indispensable role of temperature in beige fat reprogramming. Surprisingly, although EPA induced thermogenic effects in SAT-derived adipocytes harvested from both KO and WT mice, EPA only increased thermogenic gene and protein expression in the SAT of UCP1 KO mice housed at ambient temperature. Collectively, our findings indicate that the thermogenic effects of EPA, which are independent of UCP1, occur in a temperature-dependent manner.


Subject(s)
Adipose Tissue, Brown , Eicosapentaenoic Acid , Male , Animals , Mice , Temperature , Uncoupling Protein 1/genetics , Uncoupling Protein 1/metabolism , Eicosapentaenoic Acid/pharmacology , Eicosapentaenoic Acid/metabolism , Mice, Knockout , Mice, Inbred C57BL , Adipose Tissue, Brown/metabolism , Obesity/metabolism , Subcutaneous Fat/metabolism , Thermogenesis/genetics , Adipose Tissue, White/metabolism
2.
J Nutr Biochem ; 115: 109242, 2023 05.
Article in English | MEDLINE | ID: mdl-36442715

ABSTRACT

Obesity is associated with an imbalance of micro-and macro-nutrients, gut dysbiosis, and a "leaky" gut phenomenon. Polyphenols, such as curcumin, resveratrol, and anthocyanins may alleviate the systemic effects of obesity, potentially by improving gut microbiota, intestinal barrier integrity (IBI), and zinc homeostasis. The essential micronutrient zinc plays a crucial role in the regulation of enzymatic processes, including inflammation, maintenance of the microbial ecology, and intestinal barrier integrity. In this review, we focus on IBI- which prevents intestinal lipopolysaccharide (LPS) leakage - as a critical player in polyphenol-mediated protective effects against obesity-associated white adipose tissue (WAT) inflammation. This occurs through mechanisms that block the movement of the bacterial endotoxin LPS across the gut barrier. Available research suggests that polyphenols reduce WAT and systemic inflammation via crosstalk with inflammatory NF-κB, the mammalian target of rapamycin (mTOR) signaling and zinc homeostasis.


Subject(s)
Gastrointestinal Microbiome , Humans , Polyphenols/pharmacology , Lipopolysaccharides/pharmacology , Anthocyanins/pharmacology , Obesity/microbiology , Inflammation/drug therapy , Anti-Inflammatory Agents/pharmacology , Homeostasis , Zinc/pharmacology , Dysbiosis/microbiology
3.
Nutrients ; 16(1)2023 Dec 25.
Article in English | MEDLINE | ID: mdl-38201900

ABSTRACT

The plant-derived polyphenol curcumin alleviates the inflammatory and metabolic effects of obesity, in part, by reducing adipose tissue inflammation. We hypothesized that the benefits of curcumin supplementation on diet-induced obesity and systemic inflammation in mice occur through downregulation of white adipose tissue (WAT) inflammation. The hypothesis was tested in adipose tissue from high-fat diet-induced obese mice supplemented with or without curcumin and in 3T3-L1 adipocytes treated with or without curcumin. Male B6 mice were fed a high-fat diet (HFD, 45% kcal fat) with or without 0.4% (w/w) curcumin supplementation (HFC). Metabolic changes in these mice have been previously reported. Here, we determined the serum levels of the curcumin metabolites tetrahydrocurcumin (THC) and curcumin-O-glucuronide (COG) using mass spectrometry. Moreover, we determined interleukin 6 (IL-6) levels and proteomic changes in LPS-stimulated 3T3-L1 adipocytes treated with or without curcumin by using immunoassays and mass spectrometry, respectively, to gain further insight into any altered processes. We detected both curcumin metabolites, THC and COG, in serum samples from the curcumin-fed mice. Both curcumin and its metabolites reduced LPS-induced adipocyte IL-6 secretion and mRNA levels. Proteomic analyses indicated that curcumin upregulated EIF2 and mTOR signaling pathways. Overall, curcumin exerted anti-inflammatory effects in adipocytes, in part by reducing IL-6, and these effects may be linked to the upregulation of the mTOR signaling pathway, warranting additional mechanistic studies on the effects of curcumin and its metabolites on metabolic health.


Subject(s)
Curcumin , Glucuronides , Animals , Mice , Curcumin/pharmacology , Interleukin-6/genetics , Lipopolysaccharides , Proteomics , Adipocytes , Adipose Tissue, White , Anti-Inflammatory Agents/pharmacology , Inflammation/drug therapy , TOR Serine-Threonine Kinases , Obesity/drug therapy
4.
Biochim Biophys Acta Mol Basis Dis ; 1868(10): 166477, 2022 10 01.
Article in English | MEDLINE | ID: mdl-35780942

ABSTRACT

Impaired metabolic functions underlie the pathophysiology of diabetes and obesity. The renin-angiotensin system (RAS) is one pathway related to the pathophysiology of both diseases. RAS activation in metabolically active tissues exerts pro-inflammatory effects via angiotensin II (Ang II), linked to dysfunction in cellular processes such as autophagy, which is associated with obesity and diabetes. Here, we determined whether RAS is involved in metabolic dysregulations in a Type 1 Diabetes (T1D) mouse model, treated with captopril, and in an obesity mouse model (Agt-Tg) that overexpresses angiotensinogen (Agt) in adipose tissue. T1D mice had lower plasma leptin, resistin and higher non-esterified fatty acids (NEFA) compared to wild type (Wt) mice, even under captopril treatment. Further, mRNA levels for Agt, At1, Insr, and Beclin1 were upregulated in muscle and liver of T1D mice with captopril compared to Wt. Moreover, autophagy markers LC3 and p62 proteins were decreased, regardless of captopril treatment in the liver from T1D mice. In obese Wt mice, captopril increased muscle Irs1 gene levels. Further, captopril reduced mRNA levels of At1, Insr, Ampk, Beclin1, Atg12, and Lc3 in the liver from both Wt and Agt-Tg mice, while Agt, At1, Insr, and Atg12 expression was reduced in Agt-Tg mice without captopril treatment. Irs1 expression was decreased in the liver from obese Wt mice treated with captopril. Our results suggest that captopril treatment upregulates components of RAS, insulin signaling, and autophagy in both muscle and liver, indicating potential utility of captopril in targeting both insulin sensitivity and autophagy in diabetes and obesity.


Subject(s)
Captopril , Diabetes Mellitus, Type 1 , Animals , Autophagy , Beclin-1/metabolism , Captopril/pharmacology , Diabetes Mellitus, Type 1/drug therapy , Diabetes Mellitus, Type 1/metabolism , Diet , Glucose/metabolism , Liver/metabolism , Mice , Mice, Obese , Muscles/metabolism , Obesity/drug therapy , Obesity/metabolism , RNA, Messenger/metabolism
5.
Biomedicines ; 9(11)2021 Oct 27.
Article in English | MEDLINE | ID: mdl-34829779

ABSTRACT

Visceral obesity may be a driving factor in nonalcoholic fatty liver disease (NAFLD) development. Previous studies have shown that the omega-3 polyunsaturated fatty acid, eicosapentaenoic acid (EPA), ameliorates obesity in high-fat (HF) fed male, C57Bl/6 mice at thermoneutral conditions, independent of uncoupling protein 1 (UCP1). Our goals herein were to investigate sex-dependent mechanisms of EPA in the livers of wild type (WT) and UCP1 knockout (KO) male and female mice fed a HF diet (45% kcal fat; WT-HF, KO-HF) with or without supplementation of 36 g/kg EPA (WT-EPA, KO-EPA). KO significantly increased body weight in males, with no significant reductions with EPA in the WT or KO groups. In females, there were no significant differences in body weight among KO groups and no effects of EPA. In males, liver TGs were significantly higher in the KO-HF group and reduced with EPA, which was not observed in females. Accordingly, gene and protein markers of mitochondrial oxidation, peroxisomal biogenesis and oxidation, as well as metabolic futile cycles were sex-dependently impacted by KO and EPA supplementation. These findings suggest a genotypic difference in response to dietary EPA supplementation on the livers of male and female mice with diet-induced obesity and housed at thermoneutrality.

6.
Crit Rev Biochem Mol Biol ; 56(5): 455-481, 2021 10.
Article in English | MEDLINE | ID: mdl-34182855

ABSTRACT

Over accumulation of lipids in adipose tissue disrupts metabolic homeostasis by affecting cellular processes. Endoplasmic reticulum (ER) stress is one such process affected by obesity. Biochemical and physiological alterations in adipose tissue due to obesity interfere with adipose ER functions causing ER stress. This is in line with increased irregularities in other cellular processes such as inflammation and autophagy, affecting overall metabolic integrity within adipocytes. Additionally, microRNAs (miRNAs), which can post-transcriptionally regulate genes, are differentially modulated in obesity. A better understanding and identification of such miRNAs could be used as novel therapeutic targets to fight against diseases. In this review, we discuss ways in which ER stress participates as a common molecular process in the pathogenesis of obesity-associated metabolic disorders. Moreover, our review discusses detailed underlying mechanisms through which ER stress and miRNAs contribute to metabolic alteration in adipose tissue in obesity. Hence, identifying mechanistic involvement of miRNAs-ER stress cross-talk in regulating adipose function during obesity could be used as a potential therapeutic approach to combat chronic diseases, including obesity.


Subject(s)
MicroRNAs , Adipose Tissue , Endoplasmic Reticulum/genetics , Endoplasmic Reticulum Stress/genetics , Humans , MicroRNAs/genetics , Obesity/genetics
7.
J Clin Aesthet Dermatol ; 13(7): 18-23, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32983332

ABSTRACT

BACKGROUND: The effectiveness of different combined oral contraceptive pills and metformin in reducing hirsutism in patients with polycystic ovary syndrome (PCOS) remains unclear. OBJECTIVE: We sought to determine the effects of ethinylestradiol (35µg)/cyproterone acetate (2mg) (EE/CPA) and ethinylestradiol (20µg)/desogestrel (0.15mg) (EE/DES), alone or with metformin, on hirsutism in PCOS. METHODS: A randomized, double-blind, triple-dummy study was conducted on women with PCOS and hirsutism (N=107) who received one of four drug combinations (Arm A: EE/CPA; Arm B: EE/DES; Arm C: EE/CPA plus metformin; or Arm D: EE/DES plus metformin). Hirsutism was assessed at baseline, six months, and 12 months by using five outcomes variables. RESULTS: No outcomes variable showed a significant difference between the four arms at 12 months. There was a significant reduction in both hair density and modified Ferriman-Gallwey score (mFGS) in Arm A, mFGS in Arm B, hair density in Arm C, and diameter of sideburn hair in Arm D, respectively. Separately, there was a significant increase noted in the hair growth rate of chin and an improvement in patients' perceptions of hirsutism in all four study arms. CONCLUSION: EE/CPA and EE/DES were equally effective in improving hirsutism in PCOS, with no added benefit from low-dose metformin. Sri Lanka Clinical Trials Registry (http://www.slctr.lk) registration no. SLCTR/2015/007.

8.
Adipocyte ; 9(1): 360-373, 2020 12.
Article in English | MEDLINE | ID: mdl-32654628

ABSTRACT

Obesity is a complex disease of global epidemic proportions. Adipose tissue expansion and chronic low-grade inflammation, locally and systemically, are hallmark features of obesity. Obesity is associated with several other chronic diseases, which are also characterized by inflammation. Determination of adipocyte size and macrophage content in adipose tissue is a critical step in assessing changes in this tissue with obesity. Here, we introduce a complete standalone software package, AdipoGauge, to analyse microscopic images derived from haematoxylin and eosin (H&E)-stained and immunofluorescently stained histology sections of adipose tissue. The software package is a user-friendly application that does not require a vast knowledge of computer science or costly commercial tools. AdipoGauge includes analysing tools that are capable of cell counting and colour separation. Furthermore, it can quantify the cell data in images both with and without clear boundaries around the cells. It can also remove objects from the image that are not intended for analysis, such as blood vessels or partial cells at edges of slide sections. The simple and state-of-the-art graphical user interface requires minimal time and learning.


Subject(s)
Fluorescent Antibody Technique/methods , Image Processing, Computer-Assisted/methods , Immunohistochemistry/methods , Microscopy , Software , Adipocytes/pathology , Adipose Tissue/pathology , Animals , Humans , Macrophages/pathology , Mice , Microscopy/methods
9.
Cells ; 9(6)2020 05 26.
Article in English | MEDLINE | ID: mdl-32466437

ABSTRACT

Overactivation of the renin-angiotensin system (RAS) during obesity disrupts adipocyte metabolic homeostasis and induces endoplasmic reticulum (ER) stress and inflammation; however, underlying mechanisms are not well known. We propose that overexpression of angiotensinogen (Agt), the precursor protein of RAS in adipose tissue or treatment of adipocytes with Angiotensin II (Ang II), RAS bioactive hormone, alters specific microRNAs (miRNA), that target ER stress and inflammation leading to adipocyte dysfunction. Epididymal white adipose tissue (WAT) from B6 wild type (Wt) and transgenic male mice overexpressing Agt (Agt-Tg) in adipose tissue and adipocytes treated with Ang II were used. Small RNA sequencing and microarray in WAT identified differentially expressed miRNAs and genes, out of which miR-690 and mitogen-activated protein kinase kinase 3 (MAP2K3) were validated as significantly up- and down-regulated, respectively, in Agt-Tg, and in Ang II-treated adipocytes compared to respective controls. Additionally, the direct regulatory role of miR-690 on MAP2K3 was confirmed using mimic, inhibitors and dual-luciferase reporter assay. Downstream protein targets of MAP2K3 which include p38, NF-κB, IL-6 and CHOP were all reduced. These results indicate a critical post-transcriptional role for miR-690 in inflammation and ER stress. In conclusion, miR-690 plays a protective function and could be a useful target to reduce obesity.


Subject(s)
Angiotensin II/pharmacology , Endoplasmic Reticulum Stress , Inflammation/genetics , MicroRNAs/metabolism , 3T3-L1 Cells , Adipocytes/drug effects , Adipocytes/metabolism , Adipose Tissue, White/metabolism , Animals , Base Sequence , Biomarkers/metabolism , Endoplasmic Reticulum Stress/drug effects , Endoplasmic Reticulum Stress/genetics , Gene Expression Regulation/drug effects , Inflammation/pathology , MAP Kinase Signaling System/drug effects , MAP Kinase Signaling System/genetics , Male , Mice , Mice, Inbred C57BL , MicroRNAs/genetics , Renin-Angiotensin System/drug effects , Renin-Angiotensin System/genetics , Reproducibility of Results , Signal Transduction/drug effects
10.
J Nutr ; 150(7): 1693-1704, 2020 07 01.
Article in English | MEDLINE | ID: mdl-32271912

ABSTRACT

Inflammation is largely mediated by immune cells responding to invading pathogens, whereas metabolism is oriented toward producing usable energy for vital cell functions. Immunometabolic alterations are considered key determinants of chronic inflammation, which leads to the development of chronic diseases. Studies have demonstrated that macrophages and the NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome are activated in key metabolic tissues to contribute to increased risk for type 2 diabetes mellitus, Alzheimer disease, and liver diseases. Thus, understanding the tissue-/cell-type-specific regulation of the NLRP3 inflammasome is crucial for developing intervention strategies. Currently, most of the nutrients and bioactive compounds tested to determine their inflammation-reducing effects are limited to animal models. Future studies need to address how dietary compounds regulate immune and metabolic cell reprograming in humans.


Subject(s)
Gene Expression Regulation/immunology , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Brain/immunology , Humans , Inflammasomes , Liver/immunology , Macrophages , NLR Family, Pyrin Domain-Containing 3 Protein/genetics
11.
Cell Death Dis ; 11(2): 87, 2020 02 03.
Article in English | MEDLINE | ID: mdl-32015340

ABSTRACT

Metabolic syndrome (MetS) is a complex, emerging epidemic which disrupts the metabolic homeostasis of several organs, including liver, heart, pancreas, and adipose tissue. While studies have been conducted in these research areas, the pathogenesis and mechanisms of MetS remain debatable. Lines of evidence show that physiological systems, such as the renin-angiotensin system (RAS) and autophagy play vital regulatory roles in MetS. RAS is a pivotal system known for controlling blood pressure and fluid balance, whereas autophagy is involved in the degradation and recycling of cellular components, including proteins. Although RAS is activated in MetS, the interrelationship between RAS and autophagy varies in glucose homeostatic organs and their cross talk is poorly understood. Interestingly, autophagy is attenuated in the liver during MetS, whereas autophagic activity is induced in adipose tissue during MetS, indicating tissue-specific discordant roles. We discuss in vivo and in vitro studies conducted in metabolic tissues and dissect their tissue-specific effects. Moreover, our review will focus on the molecular mechanisms by which autophagy orchestrates MetS and the ways future treatments could target RAS in order to achieve metabolic homeostasis.


Subject(s)
Autophagy/physiology , Metabolic Syndrome/pathology , Renin-Angiotensin System/physiology , Adipose Tissue/metabolism , Adipose Tissue/pathology , Energy Metabolism , Heart Diseases/metabolism , Heart Diseases/pathology , Humans , Inflammation , Insulin Resistance , Liver/metabolism , Liver/pathology , Metabolic Syndrome/metabolism , Obesity/metabolism , Obesity/pathology
12.
Contemp Clin Trials Commun ; 16: 100453, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31650073

ABSTRACT

Mobile phone-based health interventions (mHealth) are viewed as an attractive approach to foster behaviour change, and found to be effective in promoting physical activity and healthy diets. The present study aims to investigate whether mHealth with advice for dietary and lifestyle modifications would reduce 10-year cardio vascular disease (CVD) risk among overweight or obese adults aged 35-64 years in Sri Lanka. A two-group parallel-arm randomized controlled trial (RCT) was conducted in Colombo district, recruiting 1200 individuals aged 35-64 years with a body mass index (BMI) of ≥25 kgm-2. Participants were randomly assigned either to mHealth package (intervention arm, n = 600) or usual care (control arm, n = 600). The intervention package contains a series of dietary and lifestyle improvement messages, a mobile application to register participants, and a web application to deliver these messages. Participants in the intervention arm receive 2 voice and 2 text messages per week to their mobile phones for a period of 12 months. The primary outcome (10-year CVD risk) will be assessed according to sex, age, smoking status, blood pressure, serum cholesterol and glycaemic status. Data are collected at enrollment and after 12 months of intervention on: dietary practices, physical activity, smoking, anthropometry, body composition, blood pressure, fasting plasma glucose, HbA1c and lipid profile. Analysis of effect will be performed by intention-to-treat principle, comparing the outcomes between intervention and control arms. The study resulted in a comprehensive mHealth nutrition and lifestyle package (mHENAL) and successfully completed recruitment and baseline assessment of participants. The message delivery is in progress.

13.
Diabetes Metab Syndr Obes ; 12: 863-872, 2019.
Article in English | MEDLINE | ID: mdl-31354322

ABSTRACT

Purpose: Nonalcoholic fatty liver disease (NAFLD) is often referred to as the hepatic manifestation of the metabolic syndrome. The relationship between body weight, NAFLD, and insulin resistance is not well characterized in humans. Additionally, it is unclear why South Asians develop these complications at lower levels of obesity compared to their Western counterparts. Patients and methods: To address this question, we performed a cross-sectional study using a convenience sample of Sri Lankan adult females (n=34) and collected anthropometric data, adipose tissue specimens (for histology), and fasted serum samples (for metabolic and inflammatory markers). Hepatic steatosis was assessed by ultrasound scanning and used to classify participants as NAFL 0, NAFL 1, and NAFL 2. Results: Waist circumference significantly increased with increasing NAFL grade. Participants with NAFL had significantly higher body mass index, hip circumference, and fasting plasma glucose, as well as a higher mean adipocyte area in both abdominal subcutaneous and visceral areas, indicating a higher degree of adipocyte hypertrophy associated with fatty liver. There were, however, no differences in measures of dyslipidemia. Of the multiple adipokines measured, resistin was the only proinflammatory adipokine significantly elevated in NAFL 2. Conclusion: These findings indicate that measures of adiposity, fasting serum glucose, and resistin may be important indicators of NAFLD in South Asian women.

14.
Sci Rep ; 9(1): 8481, 2019 06 11.
Article in English | MEDLINE | ID: mdl-31186446

ABSTRACT

The Renin Angiotensin System (RAS), a key regulator of blood pressure has been linked to metabolic disorders. We have previously reported that adipose overexpression of angiotensinogen in mice (Agt-Tg) induces obesity, in part mediated by adipose tissue inflammation, through yet unidentified mechanisms. Hence, we hypothesize that adipose tissue enrichment of angiotensinogen leads to activation of inflammatory cascades and endoplasmic reticulum (ER) stress, thereby, contributing to obesity. We used wild type (Wt), Agt-Tg and Agt-knockout (KO) mice along with 3T3-L1 and human adipocytes treated with RAS, ER stress and inflammation inhibitors. ER stress and pro-inflammation markers were significantly higher in Agt-Tg compared to Wt mice and captopril significantly reduced their expression. Furthermore, in vitro treatment with Ang II significantly induced ER stress and inflammation, whereas angiotensin II receptor inhibitor, telmisartan reduced RAS effects. Moreover, miR-30 family had significantly lower expression in Agt-Tg group. MiR-708-5p and -143-3p were upregulated when RAS was overexpressed, and RAS antagonists reduced miR-143-3p and -708-5p in both mouse adipose tissue and adipocytes. Activation of RAS by Ang II treatment, increased inflammation and ER stress in adipocytes mainly via AT1 receptor, possibly mediated by miR-30 family, -708-5p and/or -143-3p. Hence, RAS and mediating microRNAs could be used as potential targets to reduce RAS induced obesity and related comorbid diseases.


Subject(s)
Adipocytes/pathology , Adipose Tissue/pathology , Angiotensin II/pharmacology , Endoplasmic Reticulum Stress/drug effects , 3T3-L1 Cells , Adipocytes/drug effects , Adipocytes/metabolism , Adipose Tissue/drug effects , Animals , Captopril/pharmacology , Diet , Humans , Inflammation/pathology , Mice , Mice, Transgenic , MicroRNAs/genetics , MicroRNAs/metabolism , NF-kappa B/antagonists & inhibitors , NF-kappa B/metabolism , Renin-Angiotensin System/drug effects , YY1 Transcription Factor/metabolism
15.
Nutrients ; 11(3)2019 Mar 12.
Article in English | MEDLINE | ID: mdl-30871035

ABSTRACT

The prevalence of nonalcoholic fatty liver disease (NAFLD) is increasing worldwide, concurrent with increased obesity. Thus, there is urgent need for research that can lead to effective NAFLD prevention/treatment strategies. Omega-3 polyunsaturated fatty acids (n-3 PUFAs), including eicosapentaenoic acid (EPA), improve inflammation- and dyslipidemia-related metabolic disorders; however, mechanisms mediating the benefits of n-3 PUFAs in NAFLD treatment are less understood. We previously reported that EPA reversed obesity-induced hepatic steatosis in high-fat (HF)-fed B6 mice. Utilizing a combination of biochemical analyses of liver tissues from HF and HF-EPA-fed mice and a series of in vitro studies in tumor necrosis factor-alpha (TNF-α)-stimulated HepG2 cells, we dissect the mechanistic effects of EPA in reducing hepatic steatosis, including the role of EPA-targeted microRNAs (miRNA). With EPA, hepatic lipid metabolism was improved in HF-EPA mice, as indicated by decreased protein and messenger RNA (mRNA) levels of fatty acid synthase (FASN) and acetyl-CoA carboxylase (Acaca) gene, and increased mRNA levels for the peroxisome proliferator activated receptor-α (Pparα), and carnitine palmitoyltransferase (Cpt) 1a and 2 genes in the HF-EPA mice. Additionally, inflammation was reduced, as shown by decreased tumor necrosis factor-alpha (Tnfα) gene expression. Accordingly, EPA also significantly reduced FASN and ACACA mRNAs in human HepG2 cells. Glycolysis, estimated by extracellular acidification rate, was significantly reduced in HepG2 cells treated with EPA vs. vehicle. Furthermore, we identified several miRNAs that are regulated by EPA in mouse liver, including miR-19b-3p, miR-21a-5p, and others, which target lipid metabolism and inflammatory pathways. In conclusion, our findings provide novel mechanistic evidence for beneficial effects of EPA in NAFLD, through the identification of specific genes and miRNAs, which may be further exploited as future NAFLD therapies.


Subject(s)
Diet, High-Fat/adverse effects , Eicosapentaenoic Acid/pharmacology , Obesity/chemically induced , Animals , Fatty Acids/metabolism , Gene Expression Regulation/drug effects , Hep G2 Cells , Humans , Lipid Metabolism/drug effects , Lipid Peroxidation/drug effects , Liver/metabolism , Male , Mice , Mice, Inbred C57BL , MicroRNAs/metabolism
16.
Mol Nutr Food Res ; 63(7): e1800821, 2019 04.
Article in English | MEDLINE | ID: mdl-30657255

ABSTRACT

SCOPE: Brown adipose tissue (BAT) dissipates energy through uncoupling protein 1 (UCP1) and has been proposed as an anti-obesity target. It was reported previously that a high-fat (HF) diet enriched in eicosapentaenoic acid (EPA) significantly increased UCP1 and other thermogenic markers in BAT. It is hypothesized that these effects are mediated through UCP1-dependent regulation. METHODS AND RESULTS: Wild-type (WT) and UCP1 knockout (KO) B6 male mice were housed at thermoneutrality and fed a HF diet, without or with eicosapentaenoic acid (EPA)-enriched fish oil. HF-fed KO mice were heavier and had higher BAT lipid content than other groups. Protective effects of EPA in WT, previously observed at 22 °C (reduced adiposity, improved glucose tolerance, and increased UCP1), disappeared at thermoneutrality. Mitochondrial proteins, cytochrome c oxidase subunit 1 (COX I), COX I, II, and IV were reduced in the KO mice compared to WT. Unexpectedly, EPA attenuated weight and fat mass gain and improved glucose tolerance in the KO mice. Finally, EPA increased BAT peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC1α) protein and gene expression, and whole-body oxygen consumption in KO mice, consistent with increased mitochondria DNA (mtDNA)/nuclear DNA (nucDNA) ratio. CONCLUSIONS: EPA rescued the weight gain and glucose intolerance in UCP1 KO mice at thermoneutrality, independent of UCP1; these effects may be mediated in part via increased oxygen consumption and BAT PGC1α.


Subject(s)
Adipose Tissue/drug effects , Eicosapentaenoic Acid/pharmacology , Glucose Intolerance/drug therapy , Oxygen/metabolism , Uncoupling Protein 1/genetics , Adipose Tissue/metabolism , Animals , Diet, High-Fat/adverse effects , Eating/drug effects , Energy Metabolism/drug effects , Gene Expression Regulation/drug effects , Male , Mice, Knockout , Mitochondria/drug effects , Mitochondria/metabolism , Obesity/metabolism , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/genetics , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/metabolism , Temperature , Uncoupling Protein 1/metabolism , Weight Gain/drug effects
17.
Ceylon Med J ; 64(3): 82-90, 2019 Sep 30.
Article in English | MEDLINE | ID: mdl-32115403

ABSTRACT

Introduction: Adolescents have high vulnerability for body image distortions which may result in many psychological and physical problems. Objectives: This study aimed to determine body image perception and dissatisfaction among rural schooling adolescents in Sri Lanka. Methods: Adolescents (aged 13-16 years) were selected using probability-based sampling framework. Self-administered figure rating scale was used to assess perceived current (PCBS) and ideal (IBS) body size and body discrepancy score (BDS = PCBS ­ IBS). Pubertal stage was assessed with pubertal development scale. Anthropometry was done according to WHO guidelines. Results: Of 3128 students studied, 47.8% were boys. Median PCBS was 4 (inter quartile range 1) for boys and 4 (2) for girls. Boys aspire a larger body size compared to girls and the respective median IBS were 5 (0) and 4 (1). More boys (70.4%, n = 1053) than girls (66.4%, n = 1084) were dissatisfied about their current body size; χ2 = 5.5, df = 1, p < 0.05. Overweight students recorded higher PCBS and were more dissatisfied with their body size when compared to others. Nearly half of boys and 29.6% girls wanted to have a larger body size than their current. The main influencing factor of body dissatisfaction was body mass index. Conclusions: Body dissatisfaction is evident even among rural adolescents, affecting boys more than girls. Many students show a desire to have a larger body size than their current. This study also provides valid and reliable tools to assess body dissatisfaction and pubertal development in Sinhala speaking adolescents.


Subject(s)
Body Dissatisfaction/psychology , Body Image/psychology , Rural Population/statistics & numerical data , Students/psychology , Adolescent , Female , Humans , Male , Psychiatric Status Rating Scales , Sri Lanka
18.
Ceylon Med J ; 64(3): 111-117, 2019 Sep 30.
Article in English | MEDLINE | ID: mdl-32120461

ABSTRACT

Introduction: Visceral adiposity index (VAI) is a mathematical index derived from the body mass index (BMI), waist circumference (WC), serum fasting triglyceride (TG) and high-density lipoprotein cholesterol (HDL-C). It reflects visceral adipocyte dysfunction (VAD) and is associated with cardiometabolic risk. Women with polycystic ovarian syndrome (PCOS) have adipocyte dysfunction, which is associated with metabolic disorders. Hirsutism in PCOS is considered to be due to high insulin levels which enhances androgen activity at the pilosebaceous unit. Objectives: To determine the association between VAI, hirsutism and cardiometabolic risk factors in patients with PCOS. Methods: A total of 99 patients aged 18-40 years with PCOS diagnosed by the Rotterdam consensus criteria-2003 and a hirsutism score of 8 or more according to the Ferriman-Gallway Score (FGS) were studied. BMI, WC, fasting lipid profile, serum leptin, insulin, sex hormone binding globulin (SHBG), free-androgen index (FAI), fasting blood glucose (FBG) and oral glucose tolerance test (OGTT) were determined. Homeostasis model assessment (HOMA)-beta, HOMA-insulin resistance (IR) and VAI were calculated. Diameter and rate of hair growth at sideburns and chin; density of hair at sideburns were measured. Data were analyzed by SPSS-22.0. Results: There was no significant association between parameters of hirsutism and VAI. There was a significant association between VAI and OGTT, FAI, systolic and diastolic blood pressure: but not between VAI and other metabolic parameters. Conclusion: Visceral adipocyte dysfunction is closely linked to glucose intolerance and blood pressure in women with PCOS. However, hirsutism is unlikely to be due to adipocyte dysfunction.


Subject(s)
Glucose Intolerance/etiology , Hirsutism/etiology , Intra-Abdominal Fat/physiopathology , Obesity, Abdominal/etiology , Polycystic Ovary Syndrome/physiopathology , Adolescent , Adult , Blood Pressure , Body Mass Index , Cross-Sectional Studies , Fasting/blood , Female , Humans , Insulin/blood , Polycystic Ovary Syndrome/blood , Polycystic Ovary Syndrome/complications , Risk Factors , Triglycerides/blood , Waist Circumference , Young Adult
19.
Biochim Biophys Acta Mol Cell Biol Lipids ; 1863(12): 1523-1531, 2018 12.
Article in English | MEDLINE | ID: mdl-30261280

ABSTRACT

Brown adipose tissue (BAT) dissipates chemical energy as heat via thermogenesis and protects against obesity by increasing energy expenditure. However, regulation of BAT by dietary factors remains largely unexplored at the mechanistic level. We investigated the effect of eicosapentaenoic acid (EPA) on BAT metabolism. Male C57BL/6J (B6) mice were fed either a high-fat diet (HF, 45% kcal fat) or HF diet supplemented with EPA (HF-EPA, 6.75% kcal EPA) for 11 weeks. RNA sequencing (RNA-Seq) and microRNA (miRNA) profiling were performed on RNA from BAT using Illumina HiSeq and Illumina Genome Analyzer NextSeq, respectively. We conducted pathway analyses using ingenuity pathway analysis software (IPA®) and validated some genes and miRNAs using qPCR. We identified 479 genes that were differentially expressed (2-fold change, n = 3, P ≤ 0.05) in BAT from HF compared to HF-EPA. Genes negatively correlated with thermogenesis such as hypoxia inducible factor 1 alpha subunit inhibitor (Hif1an), were downregulated by EPA. Pathways related to thermogenesis such as peroxisome proliferator-activated receptor (PPAR) were upregulated by EPA while pathways associated with obesity and inflammation such as nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) were downregulated by EPA. MiRNA profiling identified nine and six miRNAs that were upregulated and downregulated by EPA, respectively (log2 fold change > 1.25, n = 3, P ≤ 0.05). Key regulatory miRNAs which were involved in thermogenesis, such as miR-455-3p and miR-129-5p were validated using qPCR. In conclusion, the depth of transcriptomic and miRNA profiling revealed novel mRNA-miRNA interaction networks in BAT which are involved in thermogenesis, and regulated by EPA.


Subject(s)
Diet, High-Fat/adverse effects , Eicosapentaenoic Acid/administration & dosage , Gene Expression Profiling/methods , Gene Regulatory Networks/drug effects , MicroRNAs/genetics , Obesity/genetics , Adipose Tissue, Brown/metabolism , Animals , Disease Models, Animal , Eicosapentaenoic Acid/pharmacology , Gene Expression Regulation/drug effects , Male , Mice , Mice, Inbred C57BL , Mice, Obese , Obesity/chemically induced , Sequence Analysis, RNA/methods
20.
Oncotarget ; 9(10): 9246-9261, 2018 Feb 06.
Article in English | MEDLINE | ID: mdl-29507687

ABSTRACT

Obesity contributes to metabolic disorders such as diabetes and cardiovascular disease. Characterization of differences between the main adipose tissue depots, white (WAT) [including subcutaneous (SAT) and visceral adipose tissue (VAT)] and brown adipose tissue (BAT) helps to identify their roles in obesity. Thus, we studied depot-specific differences in whole transcriptome and miRNA profiles of SAT, VAT and BAT from high fat diet (HFD/45% of calories from fat) fed mice using RNA sequencing and small RNA-Seq. Using quantitative real-time polymerase chain reaction, we validated depot-specific differences in endoplasmic reticulum (ER) stress related genes and miRNAs using mice fed a HFD vs. low fat diet (LFD/10% of calories from fat). According to the transcriptomic analysis, lipogenesis, adipogenesis, inflammation, endoplasmic reticulum (ER) stress and unfolded protein response (UPR) were higher in VAT compared to BAT, whereas energy expenditure, fatty acid oxidation and oxidative phosphorylation were higher in BAT than in VAT of the HFD fed mice. In contrast to BAT, ER stress marker genes were significantly upregulated in VAT of HFD fed mice than the LFD fed mice. For the first time, we report depot specific differences in ER stress related miRNAs including; downregulation of miR-125b-5p, upregulation miR-143-3p, and miR-222-3p in VAT following HFD and upregulation of miR-30c-2-3p only in BAT following a HFD in mice than the LFD mice. In conclusion, HFD differentially regulates miRNAs and genes in different adipose depots with significant induction of genes related to lipogenesis, adipogenesis, inflammation, ER stress, and UPR in WAT compared to BAT.

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