miRNAs, polyphenols, and chronic disease

Salidroside inhibits insulin resistance and hepatic steatosis by downregulating miR-21 and subsequent activation of AMPK and upregulation of PPARα in the liver and muscles of high fat diet-fed rats

This study evaluated if salidroside (SAL) alleviates high-fat diet (HFD)-induced non-alcoholic fatty liver disease (NAFLD) by downregulating miR-21. Rats (n = 8/group) were treated for 12 weeks as normal diet (control/ND), ND + agmoir negative control (NC) (150 µg/kg), ND + SAL (300 mg/kg), HFD, HFD + SAL, HFD + compound C (an AMPK inhibitor) (200 ng/kg), HFD + SAL + NXT629 (a PPAR-α antagonist) (30 mg/kg), and HFD + SAL + miR-21 agomir (150 µg/kg). SAL improved glucose and insulin tolerance and preserved livers in HFD-fed rats. In ND and HFD-fed rats, SAL reduced levels of serum and hepatic lipids and the hepatic expression of SREBP1, SREBP2, fatty acid (FA) synthase, and HMGCOAR. It also activated hepatic Nrf2 and increased hepatic/muscular activity of AMPK and levels of PPARα. All effects afforded by SAL were prevented by CC, NXT629, and miR-21 agmoir. In conclusion, activation of AMPK and upregulation of PPARα mediate the anti-steatotic effect of SAL.

Childhood obesity, metabolic syndrome, and oxidative stress: microRNAs go on stage

The incidence of childhood obesity and metabolic syndrome has grown notably in the last years, becoming major public health burdens in developed countries. Nowadays, oxidative stress is well-recognized to be closely associated with the onset and progression of several obesity-related complications within the framework of a complex crosstalk involving other intertwined pathogenic events, such as inflammation, insulin disturbances, and dyslipidemia. Thus, understanding the molecular basis behind these oxidative dysregulations could provide new approaches for the diagnosis, prevention, and treatment of childhood obesity and associated disorders. In this respect, the transcriptomic characterization of miRNAs bares great potential because of their involvement in post-transcriptional modulation of genetic expression. Herein, we provide a comprehensive literature revision gathering state-of-the-art research into the association between childhood obesity, metabolic syndrome, and miRNAs. We put special emphasis on the potential role of miRNAs in modulating obesity-related pathogenic events, with particular focus on oxidative stress.

Hsa_circ_0084912 Drives the Progression of Cervical Cancer Via Regulating miR-429/SOX2 Pathway

We focus on hsa_circ_0084912's role in Cervical cancer (CC) and its molecular pathways. In order to determine the expression of Hsa_circ_0084912, miR-429, and SOX2 in CC tissues and cells, Western blotting and quantitative real-time polymerase chain reaction (qRT-PCR) were utilized. Cell counting kit 8 (CCK-8), colony formation and Transwell assays were respectively to analyze CC cell proliferation viability, clone formation ability and migration. RNA immunoprecipitation (RIP) assay and dual-luciferase assay were used to assure the targeting correlation among hsa_circ_0084912/SOX2 and miR-429. By using a xenograft tumor model, the hsa_circ_0084912 impact on CC cell proliferation in vivo was confirmed. Hsa_circ_0084912 and SOX2 expressions were aggrandized, however, miR-429 expression was descended in CC tissues and cells. Silencing hsa_circ_0084912 inhibited cell proliferation, colony formation and migration in vitro of CC, meanwhile reducing growth of tumor in vivo. MiR-429 might be sponged by Hsa_circ_0084912 to control SOX2 expression. Hsa_circ_0084912 knockdown impact on the malignant phenotypes of CC cells was restored by miR-429 inhibitor. Moreover, SOX2 silencing eliminated the promotive effects of miR-429 inhibitors on CC cell malignancies. By raising SOX2 expression by targeting miR-429, hsa_circ_0084912 accelerated the development of CC, offering fresh proof that it is a viable target for CC treatment.

An overview of natural products that modulate the expression of non-coding RNAs involved in oxidative stress and inflammation-associated disorders

Oxidative stress is a state in which oxidants are produced in excess in the body's tissues and cells, resulting in a biological imbalance amid the generation of reactive oxygen and nitrogen species (RONS) from redox reactions. In case of insufficient antioxidants to balance, the immune system triggers signaling cascades to mount inflammatory responses. Oxidative stress can have deleterious effects on major macromolecules such as lipids, proteins, and nucleic acids, hence, Oxidative stress and inflammation are among the multiple factors contributing to the etiology of several disorders such as diabetes, cancers, and cardiovascular diseases. Non-coding RNAs (ncRNAs) which were once referred to as dark matter have been found to function as key regulators of gene expression through different mechanisms. They have dynamic roles in the onset and development of inflammatory and oxidative stress-related diseases, therefore, are potential targets for the control of those diseases. One way of controlling those diseases is through the use of natural products, a rich source of antioxidants that have drawn attention with several studies showing their involvement in combating chronic diseases given their enormous gains, low side effects, and toxicity. In this review, we highlighted the natural products that have been reported to target ncRNAs as mediators of their biological effects on oxidative stress and several inflammation-associated disorders. Those natural products include Baicalein, Tanshinone IIA, Geniposide, Carvacrol/Thymol, Triptolide, Oleacein, Curcumin, Resveratrol, Solarmargine, Allicin, aqueous extract or pulp of Açai, Quercetin, and Genistein. We also draw attention to some other compounds including Zanthoxylum bungeanum, Canna genus rhizome, Fuzi-ganjiang herb pair, Aronia melanocarpa, Peppermint, and Gingerol that are effective against oxidative stress and inflammation-related disorders, however, have no known effect on ncRNAs. Lastly, we touched on the many ncRNAs that were found to play a role in oxidative stress and inflammation-related disorders but have not yet been investigated as targets of a natural product. Shedding more light into these two last points of shadow will be of great interest in the valorization of natural compounds in the control and therapy of oxidative stress- and inflammation-associated disorders.

Cardioprotective Properties of Phenolic Compounds: A Role for Biological Rhythms

Cardiovascular diseases (CVD) are the leading cause of deaths worldwide and their prevalence is continuously increasing. Available treatments may present several side effects and therefore the development of new safer therapeutics is of interest. Phenolic compounds have shown several cardioprotective properties helpful in reducing different CVD risk factors such as inflammation, elevated blood pressure, hyperlipidemia, or endothelial dysfunction. These factors are significantly influenced by biological rhythms which are in fact emerging as key modulators of important metabolic and physiological processes. Thus, increased events of CVD have been observed under circadian rhythm disruption or in winter versus other seasons. These rhythms can also affect the functionality of phenolic compounds. Indeed, different effects have been observed depending on the administration time or under different photoperiods. Therefore, in this review the focus will be on the potential of phenolic compounds as therapeutics to prevent CVD via biological rhythm modulation.

Polyphenols target miRNAs as a therapeutic strategy for diabetic complications

MiRNAs are a large group of non-coding RNAs which participate in different cellular pathways like inflammation and oxidation through transcriptional, post-transcriptional, and epigenetic regulation. In the post-transcriptional regulation, miRNA interacts with the 3'-UTR of mRNAs and prevents their translation. This prevention or dysregulation can be a cause of pathological conditions like diabetic complications. A huge number of studies have revealed the association between miRNAs and diabetic complications, including diabetic nephropathy, cardiomyopathy, neuropathy, retinopathy, and delayed wound healing. To address this issue, recent studies have focused on the use of polyphenols as selective and safe drugs in the treatment of diabetes complications. In this article, we will review the involvement of miRNAs in diabetic complications' occurrence or development. Finally, we will review the latest findings on targeting miRNAs by polyphenols like curcumin, resveratrol, and quercetin for diabetic complications therapy.

ncRNAs and polyphenols: new therapeutic strategies for hypertension

Polyphenols have gained significant attention in protecting several chronic diseases, such as cardiovascular diseases (CVDs). Accumulating evidence indicates that polyphenols have potential protective roles for various CVDs. Hypertension (HTN) is among the hazardous CVDs accounting for nearly 8.5 million deaths worldwide. HTN is a complex and multifactorial disease and a combination of genetic susceptibility and environmental factors play major roles in its development. However, the underlying regulatory mechanisms are still elusive. Polyphenols have shown to cause favourable and beneficial effects in the management of HTN. Noncoding RNAs (ncRNAs) as influential mediators in modulating the biological properties of polyphenols, have shown significant footprints in CVDs. ncRNAs control basic functions in virtually all cell types relevant to the cardiovascular system and, thus, a direct link with blood pressure (BP) regulation is highly probable. Recent evidence suggests that a number of ncRNAs, including main small ncRNAs, microRNAs (miRNAs) and long ncRNAs (lncRNAs), play crucial roles with respect to the antihypertensive effects of polyphenols. Indeed, targeting lncRNAs by polyphenols will be a novel and promising strategy in the management of HTN. Herein, we reviewed the effects of polyphenols in HTN. Additionally, we emphasized on the potential effects of polyphenols on regulations of main ncRNAs, which imply the role of polyphenols in regulating ncRNAs in order to exert protective effects and thus proposing them as new targets for HTN treatment.Abbreviations : CVD: cardiovascular disease; BP: blood pressure; HTN: hypertension, lncRNAs: long noncoding RNAs; p38-MAPK: p38-mitogenactivated protein kinase; OPCs: oligomeric procyanidins; GTP: guanosine triphosphate; ROS: reactive oxygen species; cGMP: cyclic guanosine monophosphate; SGC: soluble guanylate cyclase; PI3K: phosphatidylinositol 3-kinase; cGMP: Cyclic GMP; eNOS: endothelial NO synthase; ERK ½: extracellular signal-regulated kinase ½; L-Arg: L-Arginine; MAPK: mitogen-activated protein kinases; NO: Nitric oxide; P: Phosphorus; PDK1: Phosphoinositide-dependent kinase 1; PI3-K: Phosphatidylinositol 3-kinase; PIP2: Phosphatidylinositol diphosphate; ncRNAs: non-protein-coding RNA; miRNAs: microRNAs; OPCs: oligomeric procyanidins; RES: resveratrol; GE: grape extract; T2DM: type 2 diabetes mellitus; IL: interleukin; TNF-α: tumour necrosis factor-alpha; NF-κB: nuclear factor NF-kappa-B; ALP: alkaline phosphatase; PARP1: poly [ADP-ribose] polymerase 1; HIF1a: Hypoxia-inducible-factor 1A; NFATc2: nuclear factor of activated T cells 2; PAD: peripheral artery disease; SHR: spontaneously hypertensive rat; RAAS: renin-angiotensin-aldosterone system; AT₁R: angiotensin type-1 receptor; Nox: NADPH oxidase; HO-1: haem oxygenase-1; JAK/STAT: Janus kinase/signal transducers/activators of the transcription; PNS: panax notoginseng saponin; snoRNA: small nucleolar RNA; hnRNA: heterogeneous nuclear RNA; VSMCs: vascular smooth muscle cells; irf7: interferon regulatory factor 7; limo2: LIM only domain 2; GWAS: genome-wide association study; GAS5: Growth arrest-specific 5; Asb3, Ankyrin repeat and SPCS box containing 3; Chac2: cation transport regulator homolog 2; Pex11b: peroxisomal membrane 11B; Sp5: Sp5 transcription factor; EGCG: epigallocatechin gallate; ApoE: Apo lipoprotein E; ERK-MAP kinase: extracellular signal-regulated kinases-mitogen-activated protein kinase; PAH: pulmonary artery hypertension; PAP: pulmonary arterial pressure; HIF1a: hypoxia-inducible-factor 1A; NFATc2: nuclear factor of activated T cells 2; HMEC-1: Human microvascular endothelial cells; stat2: signal transducers and activators of transcription 2; JNK: c-Jun N-terminal kinase; iNOS: inducible NO synthase. SNP: single nucleotide polymorphism; CAD: coronary artery disease.

Natural and Synthetic Agents Targeting Reactive Carbonyl Species against Metabolic Syndrome

Reactive carbonyl species (RCS) may originate from the oxidation of unsaturated fatty acids and sugar in conditions of pathology. They are known to have high reactivity towards DNA as well as nucleophilic sites of proteins, resulting in cellular dysfunction. It has been considered that various pathological conditions are associated with an increased level of RCS and their reaction products. Thus, regulating the levels of RCS may be associated with the mitigation of various metabolic and neurodegenerative disorders. In order to perform a comprehensive review, various literature databases, including MEDLINE, EMBASE, along with Google Scholar, were utilized to obtain relevant articles. The voluminous review concluded that various synthetic and natural agents are available or in pipeline research that hold tremendous potential to be used as a drug of choice in the therapeutic management of metabolic syndrome, including obesity, dyslipidemia, diabetes, and diabetes-associated complications of atherosclerosis, neuropathy, and nephropathy. From the available data, it may be emphasized that various synthetic agents, such as carnosine and simvastatin, and natural agents, such as polyphenols and terpenoids, can become a drug of choice in the therapeutic management for combating metabolic syndromes that involve RCS in their pathophysiology. Since the RCS are known to regulate the biological processes, future research warrants detailed investigations to decipher the precise mechanism.

Sumac fruit supplementation improve glycemic parameters in patients with metabolic syndrome and related disorders: A systematic review and meta-analysis

BACKGROUND

Metabolic syndrome (MetS) is the one of the main causes of mortality worldwide. Several randomized controlled trials (RCTs) have revealed the beneficial effects of sumac (Rhus coriaria) on cardiometabolic risk factors. However, the entirety of the evidence has yet to be summarized in a systematic review.

OBJECTIVE

The aim of this systematic review and meta-analysis was to evaluate the effects of sumac on several cardiometabolic risk factors in patients with MetS and related disorders.

METHODS

We reviewed Medline, Scopus, Web of Science and Cochrane CENTRAL for RCTs published from inception to December 2020 evaluating the impact of sumac in adults with MetS or related disorders. Outcome measures included anthropometric measures, glycemic indices, blood lipids, blood pressure and liver enzymes. Pooled effect sizes were reported as standard mean differences (SMDs) and 95% confidence intervals (CIs). Trials were pooled using a random effects model.

RESULTS

Nine studies enrolling 526 participants met the inclusion criteria for this meta-analysis. Our results indicate that sumac intake significantly decrease fasting blood sugar (FBS) (SMD: -0.28; 95% CI: -0.54, -0.02; I² = 00.0%), insulin (SMD: -0.67; 95% CI: -0.99, -0.36; I² = 03.7%), and insulin resistance (measured through the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR)) (SMD: -0.79; 95% CI: -1.24, -0.34; I² = 50.1%). Sumac intake did not have a significant impact on weight, body mass index (BMI), waist circumference (WC), hip circumference (HC), waist to hip ratio (WHR), HbA1c, total cholesterol (TC), triglycerides (TG), high density lipoproteins (HDL), low density lipoprotein (LDL), systolic blood pressure (SBP), diastolic blood pressure (DBP), aspartate transaminase (AST) and alanine transaminase (ALT).

CONCLUSION

Sumac, as an adjuvant therapy, may decrease serum levels of FBS, insulin and HOMA-IR. However, due to high heterogeneity in the included studies, these findings must be interpreted with great caution. Larger, well-designed placebo-controlled clinical trials are still needed to further evaluate the capacity of sumac as a complementary treatment to control MetS risk factors.

Mastiha has efficacy in immune-mediated inflammatory diseases through a microRNA-155 Th17 dependent action

Mastiha is a natural nutritional supplement with known anti-inflammatory properties. Non-alcoholic fatty liver disease (NAFLD) and Inflammatory bowel disease (IBD) are immune mediated inflammatory diseases that share common pathophysiological features. Mastiha has shown beneficial effects in both diseases. MicroRNAs have emerged as key regulators of inflammation and their modulation by phytochemicals have been extensively studied over the last years. Therefore, the aim of this study was to investigate whether a common route exists in the anti-inflammatory activity of Mastiha, specifically through the regulation of miRNA levels. Plasma miR-16, miR-21 and miR-155 were measured by Real-Time PCR before and after two double blinded and placebo-controlled randomized clinical trials with Mastiha. In IBD and particularly in ulcerative colitis patients in relapse, miR-155 increased in the placebo group (p = 0.054) whereas this increase was prevented by Mastiha. The mean changes were different in the two groups even after adjusting for age, sex and BMI (p = 0.024 for IBD and p = 0.042). Although the results were not so prominent in NAFLD, miR-155 displayed a downward trend in the placebo group (p = 0.054) whereas the levels did not changed significantly in the Mastiha group in patients with less advanced fibrosis. Our results propose a regulatory role for Mastiha in circulating levels of miR-155, a critical player in T helper-17 (Th17) differentiation and function.

Personalized Nutrition Approach in Pregnancy and Early Life to Tackle Childhood and Adult Non-Communicable Diseases

The development of childhood and adult non-communicable diseases (NCD) is associated with environmental factors, starting from intrauterine life. A new theory finds the roots of epigenetic programming in parental gametogenesis, continuing during embryo development, fetal life, and finally in post-natal life. Maternal health status and poor nutrition are widely recognized as implications in the onset of childhood and adult diseases. Early nutrition, particularly breastfeeding, also plays a primary role in affecting the health status of an individual later in life. A poor maternal diet during pregnancy and lack of breastfeeding can cause a nutrient deficiency that affects the gut microbiota, and acts as a cofactor for many pathways, impacting the epigenetic controls and transcription of genes involved in the metabolism, angiogenesis, and other pathways, leading to NCDs in adult life. Both maternal and fetal genetic backgrounds also affect nutrient adsorption and functioning at the cellular level. This review discusses the most recent evidence on maternal nutrition and breastfeeding in the development of NCD, the potentiality of the omics technologies in uncovering the molecular mechanisms underlying it, with the future prospective of applying a personalized nutrition approach to prevent and treat NCD from the beginning of fetal life.

Grape seed proanthocyanidins suppressed macrophage foam cell formation by miRNA-9 via targeting ACAT1 in THP-1 cells

Abnormal lipid metabolism in macrophages leads to atherosclerosis (AS). Excessive LDL cholesterol uptake by macrophages in the aortic endothelium leads to formation of foam cells. Previous studies suggested that proanthocyanidins effectively suppress this process, while the in-depth mechanism has not been elucidated. In mononuclear THP-1 cells, we found that the oligomeric fraction of proanthocyanidins was more effective in suppressing foam cell formation and 25 μg ml-1 for 48 h were the optimum conditions. Under these model conditions, we investigated gene expression and for the first time reported expression of regulatory microRNA (miRNA). It was found that the proanthocyanidins restrained macrophage foaming mainly by lowering the expression levels of cholesterol influx-related receptors CD36 and SR-A, and promoting the expression of cholesterol efflux-related receptor ABCA1. Further, it was latest revealed that proanthocyanidins could notably inhibit the expression of ACAT1, a key gene for intracellular cholesterol esterification. Further investigation was performed on the expression of regulatory miRNAs (miR-134 for CD36, miR-134, miR-155 for SR-A, miR-155, let-7g for LOX-1, miR-9 for ACAT1, miR-27a, miR-19b, miR-10b and miR-33a for ABCA1). The relative expression of miR-9, a miRNA targeting ACAT1, was decreased after the treatment of proanthocyanidins. It was most likely that proanthocyanidins suppressed the expression of ACAT1 via up-regulating the expression of miR-9, thus lessening the intracellular lipid accumulation and eventually inhibiting macrophage foam cell formation. This assumption was further verified by use of miR-9 mimic and its inhibitor.

Reprogramming of miR-181a/DNA methylation patterns contribute to the maternal nicotine exposure-induced fetal programming of cardiac ischemia-sensitive phenotype in postnatal life

Background: E-cigarette and other novel electronic nicotine delivery systems (ENDS) have recently entered the market at a rapid pace. The community desperately needs answers about the health effects of ENDS. The present study tested the hypothesis that perinatal nicotine exposure (PNE) causes a gender-dependent increase in vulnerability of the heart to ischemia-reperfusion (I/R) injury and cardiac dysfunction in male rat offspring via reprogramming of the miRNA-181a (miR-181a)-mediated signaling pathway and that miR-181a antisense could rescue this phenotype. Methods: Nicotine or saline was administered to pregnant rats via subcutaneous osmotic minipumps from gestational day 4 until postnatal day 10. Cardiac function and molecular biological experiments were conducted in ~3- month-old offspring. Results: PNE enhanced I/R-induced cardiac dysfunction and infarction in adult male but not in female offspring, which was associated with miR-181a over-expression in left ventricle tissues. In addition, PNE enhanced offspring cardiac angiotensin receptor (ATR) expressions via specific CpG hypomethylation of AT₁R/AT₂R promoter. Furthermore, PNE attenuated cardiac lncRNA H19 levels, but up-regulated cardiac TGF-β/Smads family proteins and consequently up-regulated autophagy-related protein (Atg-5, beclin-1, LC3 II, p62) expression in the male offspring. Of importance, treatment with miR-181a antisense eliminated the PNE's effect on miR-181a expression/H19 levels and reversed PNE-mediated I/R-induced cardiac infarction and dysfunction in male offspring. Furthermore, miR-181a antisense also attenuated the effect of PNE on AT₁R/AT₂R/TGF-β/Smads/autophagy-related biomarkers in the male offspring. Conclusion: Our data suggest that PNE could induce a reprogramming of cardiac miR-181a expression/DNA methylation pattern, which epigenetically modulates ATR/TGF-β/autophagy signaling pathways, leading to gender-dependent development of ischemia-sensitive phenotype in postnatal life. Furthermore, miR-181a could severe as a potential therapeutic target for rescuing this phenotype.

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.

The Two-Way Polyphenols-Microbiota Interactions and Their Effects on Obesity and Related Metabolic Diseases

Metabolic diseases can change the gut microbiota composition and function, and pathogenic bacteria contribute to the development of metabolic disorders. Polyphenols may act in the gut microbiota to favor the increase of beneficial bacteria and hamper the increase of pathogenic bacteria. In addition, the microbiota may act on polyphenols to increase their bioavailability. This two-way interactions between polyphenols and the gut microbiota could affect human metabolism and reduce cardiometabolic risk. Despite the possible benefits of polyphenols for human health through modulating the microbiome, studies are scarce, and present several limitations. This review provides an overview of the polyphenol-microbiota interactions and its effects on metabolic disorders.

Health benefits of resveratrol: Evidence from clinical studies

Resveratrol is a polyphenolic nutraceutical that exhibits pleiotropic activities in human subjects. The efficacy, safety, and pharmacokinetics of resveratrol have been documented in over 244 clinical trials, with an additional 27 clinical trials currently ongoing. Resveretrol is reported to potentially improve the therapeutic outcome in patients suffering from diabetes mellitus, obesity, colorectal cancer, breast cancer, multiple myeloma, metabolic syndrome, hypertension, Alzheimer's disease, stroke, cardiovascular diseases, kidney diseases, inflammatory diseases, and rhinopharyngitis. The polyphenol is reported to be safe at doses up to 5 g/d, when used either alone or as a combination therapy. The molecular basis for the pleiotropic activities of resveratrol are based on its ability to modulate multiple cell signaling molecules such as cytokines, caspases, matrix metalloproteinases, Wnt, nuclear factor-κB, Notch, 5'-AMP-activated protein kinase, intercellular adhesion molecule, vascular cell adhesion molecule, sirtuin type 1, peroxisome proliferator-activated receptor-γ coactivator 1α, insulin-like growth factor 1, insulin-like growth factor-binding protein 3, Ras association domain family 1α, pAkt, vascular endothelial growth factor, cyclooxygenase 2, nuclear factor erythroid 2 like 2, and Kelch-like ECH-associated protein 1. Although the clinical utility of resveratrol is well documented, the rapid metabolism and poor bioavailability have limited its therapeutic use. In this regard, the recently produced micronized resveratrol formulation called SRT501, shows promise. This review discusses the currently available clinical data on resveratrol in the prevention, management, and treatment of various diseases and disorders. Based on the current evidence, the potential utility of this molecule in the clinic is discussed.

Histopathological and Biochemical Effects of Thyme Essential Oil on H2O2 Stress in Heart Tissues

BACKGROUND

Thymus algeriensis (T. algeriensis) is traditionally used in Tunisia to treat many human diseases. The aim of the present study was to investigate whether terpenes extracted from the aerial parts of T. algeriensis are potent cardioprotective agents for hydrogen peroxide (H₂O₂)-induced cardiotoxicity in rats.

METHOD

Thirty (30) rats were divided into six groups as per the experimental design: control (n = 6); 0.1 mmol/L H₂O₂ (LD H₂O₂) (n = 6); 1 mmol/L H₂O₂ (HD H₂O₂) (n = 6); oily fraction of T. algeriensis (OFTS) (180 mg/kg b.wt) (n = 6); OFTS + 0.1 mmol/L H₂O₂ (n = 6); and OFTS + 1 mmol/L H₂O₂ (n = 6).

RESULTS

The H₂O₂ demonstrated concentration-dependent cardiotoxic effects in vitro. While, exposure of rats to OFTS significantly depleted H₂O₂-induced protein oxidation and lipid peroxidation, it raised antioxidant defence enzymes, and protected against H₂O₂-induced histopathological alterations. The antioxidant potential of the thyme essence was assessed by both enzymatic and non-enzymatic antioxidants.

CONCLUSION

In conclusion, OFTS may be a potential compound for the therapy of oxidative stress-induced heart disease.

Polyphenols regulating microRNAs and inflammation biomarkers in obesity

Obesity is one of the most prevalent health problems worldwide. It is a complex disease that is generally accompanied by insulin resistance, increases in oxidative stress and inflammation biomarkers, and potentially, microRNA (miRNA) dysregulation. Polyphenols may act on obesity and its metabolic consequences. Circulating miRNAs have been studied as potential biomarkers for inflammatory and metabolic diseases, and their use may improve the diagnostic tools currently available and the ability to diagnose specific diseases. To our knowledge, data regarding the link between the consumption of polyphenols from food sources, miRNA expression, and inflammation biomarkers related to obesity is scarce, and most data available describing this relationship are found in cancer studies. This review focuses on the polyphenols that modulate the metabolism, inflammation, or both related to obesity to understand the extent to which miRNA expression can be modulated by dietary interventions.

Dietary compounds have potential in controlling atherosclerosis by modulating macrophage cholesterol metabolism and inflammation via miRNA

Atherosclerosis (AS) is a typical example of a widespread fatal cardiovascular disease. Accumulation of cholesterol-laden macrophages in the artery wall forms the starting point of AS. Increased influx of oxidized low-density lipoprotein to macrophages and decreased efflux of free cholesterol out of macrophages constitute major factors promoting the development of AS. Inflammation further aggravates the development of AS along or via interaction with the cholesterol metabolism. Many microRNAs (miRNAs) are related to the regulation of macrophage in AS in aspects of cholesterol metabolism and inflammation signaling. Dietary compounds perform AS inhibitory effects via miRNAs in the cholesterol metabolism (miR-19b, miR-378, miR-10b, miR-33a, and miR-33b) and two miRNAs in the inflammation signaling (miR-155 and miR-146a). The targeted miRNAs in the cholesterol metabolism vary greatly among different food compounds; however, in inflammation signaling, most food compounds target miR-155. Many receptors are involved in macrophages via miRNAs, including ABCA1 and ABCG1 as major receptors in the cholesterol metabolism, while nuclear factor-κB (NF-κB) and Nrf2 signaling and PI3K/AKT signaling pathways are targeted during inflammation. This article reviews current literature to investigate possible AS therapy with dietary compounds via targeting miRNAs. Currently existing problems were also discussed to guide further studies.

Resveratrol and pterostilbene as a microRNA-mediated chemopreventive and therapeutic strategy in prostate cancer

Growing evidence indicates that deregulation of the epigenetic machinery comprising the microRNA (miRNA) network is a critical factor in the progression of various diseases, including cancer. Concurrently, dietary phytochemicals are being intensively studied for their miRNA-mediated health-beneficial properties, such as anti-inflammatory, cardioprotective, antioxidative, and anticancer properties. Available experimental data have suggested that dietary polyphenols may be effective miRNA-modulating chemopreventive and therapeutic agents. Moreover, noninvasive detection of changes in miRNA expression in liquid biopsies opens enormous possibilities for their clinical utilization as novel prognostic and predictive biomarkers. In our published studies, we identified resveratrol-regulated miRNA profiles in prostate cancer. Resveratrol downregulated the phosphatase and tensin homolog (PTEN)-targeting members of the oncogenic miR-17 family of miRNAs, which are overexpressed in prostate cancer. We have functionally validated the miRNA-mediated ability of resveratrol and its potent analog pterostilbene to rescue the tumor suppressor activity of PTEN in vitro and in vivo. Taken together, our findings implicate the use of resveratrol and its analogs as an attractive miRNA-mediated chemopreventive and therapeutic strategy in prostate cancer and the use of circulating miRNAs as potential predictive biomarkers for clinical development.

Fish Oil Feeding Modulates the Expression of Hepatic MicroRNAs in a Western-Style Diet-Induced Nonalcoholic Fatty Liver Disease Rat Model

Nonalcoholic fatty liver disease (NAFLD) is one of the most prevalent chronic liver diseases worldwide. Recent studies have indicated that fish oil supplementation has benefits against NAFLD. Our previous transcriptomic study has validated the effect of fish oil supplementation on altering hepatic gene expression in a NAFLD rat model. In the current study, we examined the effects of fish oil on the expression of hepatic microRNAs. Male Sprague–Dawley rats were fed with a lab chow (CON), high-fat high-cholesterol diet (WD), or WD supplemented with fish oil (FOH), respectively. Small RNAs were extracted from livers for RNA-sequencing. A total of 79 miRNAs were identified as differentially expressed miRNAs (DEMs) between FOH and WD groups, exemplified by rno-miR-29c-3p, rno-miR-30d-5p, rno-miR-33-5p, rno-miR-34a, and rno-miR-328a-3p. Functional annotation of DEMs predicted target genes suggested that the altered hepatic miRNAs contributed to fish oil modification of hepatic lipid metabolism and signaling transduction. Integrative analysis of DEMs and differentially expressed genes suggested that the expression difference of Pcsk9, Insig2, Per3, and Socs1/3 between FOH and WD groups may be due to miRNA modification. Our study reveals that fish oil supplementation alters hepatic expression of miRNAs, which may contribute to fish oil amelioration of NAFLD in rats.

Effects of Polyphenols on Oxidative Stress-Mediated Injury in Cardiomyocytes

Cardiovascular diseases are the main cause of mortality and morbidity in the world. Hypertension, ischemia/reperfusion, diabetes and anti-cancer drugs contribute to heart failure through oxidative and nitrosative stresses which cause cardiomyocytes nuclear and mitochondrial DNA damage, denaturation of intracellular proteins, lipid peroxidation and inflammation. Oxidative or nitrosative stress-mediated injury lead to cardiomyocytes apoptosis or necrosis. The reactive oxygen (ROS) and nitrogen species (RNS) concentration is dependent on their production and on the expression and activity of anti-oxidant enzymes. Polyphenols are a large group of natural compounds ubiquitously expressed in plants, and epidemiological studies have shown associations between a diet rich in polyphenols and the prevention of various ROS-mediated human diseases. Polyphenols reduce cardiomyocytes damage, necrosis, apoptosis, infarct size and improve cardiac function by decreasing oxidative stress-induced production of ROS or RNS. These effects are achieved by the ability of polyphenols to modulate the expression and activity of anti-oxidant enzymes and several signaling pathways involved in cells survival. This report reviews current knowledge on the potential anti-oxidative effects of polyphenols to control the cardiotoxicity induced by ROS and RNS stress.

8-C-(E-phenylethenyl)quercetin from onion/beef soup induces autophagic cell death in colon cancer cells through ERK activation

SCOPE

Quercetin, a flavonoid, widely distributed in edible fruits and vegetables, was reported to effectively inhibit 2-amino-1-methyl-6-phenylimidazo[4, 5-b]pyridine (PhIP) formation in a food model (roast beef patties) with itself being converted into a novel compound 8-C-(E-phenylethenyl)quercetin (8-CEPQ). Here we investigated whether 8-CEPQ could be formed in a real food system, and tested its anticancer activity in human colon cancer cell lines.

METHODS AND RESULTS

LC-MS was applied for the determination of 8-CEPQ formation in onion/beef soup. Anticancer activity of 8-CEPQ was evaluated by using cell viability assay and flow cytometry. Results showed that 8-CEPQ suppressed proliferation and caused G₂ phase arrest in colon cancer cells. Based on immunofluorescent staining assay, western blot assay, and RNA knockdown data, we found that 8-CEPQ did not cause apoptotic cell death. Instead, it induced autophagic cell death. Moreover, treatment with 8-CEPQ induced phosphorylation of extracellular signal-regulated kinase (ERK). Inhibition of ERK phosphorylation by the mitogen-activated protein kinase kinase (MEK)/ERK inhibitor U0126 attenuated 8-CEPQ-induced autophagy and reversed 8-CEPQ-mediated cell growth inhibition.

CONCLUSION

Our results demonstrate that 8-CEPQ, a novel quercetin derivative, could be formed in onion/beef soup. 8-CEPQ inhibited colon cancer cell growth by inducing autophagic cell death through ERK activation.

miR-106b inhibits tau phosphorylation at Tyr18 by targeting Fyn in a model of Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by β-amyloid deposits and neurofibrillary tangles consisting of hyperphosphorylated tau protein. Increasing evidence has revealed that microRNAs (miRNAs) are implicated in the pathogenesis of AD. However, the effect of miRNAs on abnormal tau phosphorylation remains largely unclear so far. In this study, we investigated the role of miR-106b in tau phosphorylation and identified a new molecular mechanism of the hyperphosphorylation of tau. The results of qRT-PCR showed that the expression level of miR-106b was decreased, but Fyn was increased in the temporal cortex of AD patients. Overexpression of miR-106b inhibited Aβ1-42-induced tau phosphorylation at Tyr18 in SH-SY5Y cells stably expressing tau (SH-SY5Y/tau), whereas no changes were observed in tau phosphorylation at Ser396/404. Dual-luciferase reporter gene assay validated that Fyn was a direct target gene of miR-106b. In addition, western blot analysis revealed that Fyn protein expression was suppressed when SH-SY5Y cells were transfected with miR-106b mimics. Endogenous Fyn expression was knockdown by transfection with a small interfering RNA specific for Fyn (si-Fyn). The phosphorylation level of tau at Tyr 18 was decreased in the si-Fyn group compared with the negative control group, but the inhibitory effect of si-Fyn on tau phosphorylation was attenuated when miR-106b expression was inhibited. Taken together, these data suggest that miR-106b inhibits Aβ1-42-induced tau phosphorylation at Tyr18 by targeting Fyn. Our findings extend the knowledge about the regulation of tau phosphorylation and the regulatory mechanism of Fyn gene expression.

Involvement of miR-539-5p in the inhibition of de novo lipogenesis induced by resveratrol in white adipose tissue

Proposed miRNA mechanisms of action of resveratrol in triacylglycerol metabolism changes in adipose tissue.

Shikonin inhibits adipogenic differentiation via regulation of mir-34a-FKBP1B

Shikonin is a naturally occurring naphthoquinone pigment and a major constituent present in Lithospermum erythrorhizon. Since microRNAs (miRNAs) are one of the key post-transcriptional regulators of adipogenesis, their manipulation represents a potential new strategy to inhibit adipogenesis. Our aim was to investigate shikonin-dependent inhibition of adipogenesis with an emphasis on miRNA-related processes. Mir-34a increased during induced adipogenesis, and this was suppressed in the presence of shikonin. mRNA expression of FKBP1B, a suggested target of mir-34a according to bioinformatics studies, decreased during adipogenesis, but was recovered by shikonin treatment, which reversely correlated with mir-34a expression. A mir-34a inhibitor suppressed MDI-induced adipogenesis by blocking PPARγ and C/EBPα expression, while suppression of mir-34a recovered MDI-induced down-regulation of FKBP1B expression. A mir-34a mimic decreased FKBP1B mRNA expression in 3T3-L1 preadipocytes. We also observed that mir-34a bound directly to the 3'-untranslated region of FKBP1B. Finally, FKBP1B overexpression attenuated MDI-induced adipogenesis, PPARγ, and C/EBPα expression. These results suggest that mir-34a regulates adipogenesis by targeting FKBP1B expression. Our findings reveal that shikonin prevents adipogenesis by blocking the mir-34a-FKBP1B pathway which represents a promising potential target for preventing obesity.

Intake of grape procyanidins during gestation and lactation impairs reverse cholesterol transport and increases atherogenic risk indexes in adult offspring

Cardiovascular disease (CVD) is one of the most prevalent noncommunicable diseases in humans. Different studies have identified dietary procyanidins as bioactive compounds with beneficial properties against CVD by improving lipid homeostasis, among other mechanisms. The aim of this work was to assess whether grape seed procyanidin consumption at a physiological dose during the perinatal period could influence the CVD risk of the offspring. Wistar rat dams were treated with a grape seed procyanidin extract (GSPE; 25mg/kg of body weight per day) or vehicle during gestation and lactation. The adult male offspring of GSPE-treated dams presented decreased high-density lipoprotein cholesterol (HDL-C) levels, increased total cholesterol-to-HDL-C ratios and an exacerbated fasting triglyceride-to-HDL-C ratios (atherogenic index of plasma) compared to the control group. Impaired reverse cholesterol transport (RCT) was evidenced by the accumulation of cholesterol in skeletal muscle and by decreased fecal excretion of cholesterol and bile acids, which was consistent with the observed mRNA down-regulation of the rate-limiting enzyme in the hepatic bile acid synthesis pathway Cyp7A1. Conversely, GSPE programming also resulted in up-regulated gene expression of different key components of the RCT process, such as hepatic Npc1, Abcg1, Abca1, Lxra, Srebp2, Lcat, Scarb1 and Pltp, and the repression of microRNA miR-33a expression, a key negative controller of hepatic RCT at the gene expression level. Our results show that maternal intake of grape procyanidins during the perinatal period impacts different components of the RCT process, resulting in increased CVD risk in the adult offspring.

Targeting metabolic disorders by natural products

The most prevalent metabolic disorders are diabetes mellitus, obesity, dyslipidemia, osteoporosis and metabolic syndrome, which are developed when normal metabolic processes are disturbed. The most common pathophysiologies of the above disorders are oxidative stress, Nrf2 pathways, epigenetic, and change in miRNA expression. There is a challenge in the prevention and treatment of metabolic disorders due to severe adverse effects of some synthetic drugs, their high cost, lack of safety and poverty in some conditions, and insufficient accessibility for the general population in the world. With increasing interest in shifting from synthetic drugs to phytotherapy as an alternative treatment, there is still a gap in scientific evidences of plant-derived therapeutic benefits. One reason may be slow rate of translation of animal studies' findings into human clinical trials. Since metabolic disorders are multifactorial, it seems that poly-herbal medications, or drug-herbal combination are needed for their treatment. However, further researches to determine the most effective plant-derived metabolites, and their cellular mechanism in order to set priorities for well-designed animal and clinical trials, and also more studies with strong scientific evidences such as systematic review and meta-analysis of controlled studies are needed.

Living long and ageing well: is epigenomics the missing link between nature and nurture?

Human longevity is a complex trait and increasingly we understand that both genes and lifestyle interact in the longevity phenotype. Non-genetic factors, including diet, physical activity, health habits, and psychosocial factors contribute approximately 50% of the variability in human lifespan with another 25% explained by genetic differences. Family clusters of nonagenarian and centenarian siblings, who show both exceptional age-span and health-span, are likely to have inherited facilitatory gene groups, but also have nine decades of life experiences and behaviours which have interacted with their genetic profiles. Identification of their shared genes is just one small step in the link from genes to their physical and psychological profiles. Behavioural genomics is beginning to demonstrate links to biological mechanisms through regulation of gene expression, which directs the proteome and influences the personal phenotype. Epigenetics has been considered the missing link between nature and nurture. Although there is much that remains to be discovered, this article will discuss some of genetic and environmental factors which appear important in good quality longevity and link known epigenetic mechanisms to themes identified by nonagenarians themselves related to their longevity. Here we suggest that exceptional 90-year old siblings have adopted a range of behaviours and life-styles which have contributed to their ageing-well-phenotype and which link with important public health messages.

The effect of polyunsaturated fatty acids on obesity through epigenetic modifications

BACKGROUND AND PURPOSE

In recent years it has been demonstrated that polyunsaturated fatty acids (PUFA) have anti-inflammatory and as regulators of lipid metabolism. However, the epigenomic mechanisms involved in these processes are not known in depth. The aim of this review was to describe the scientific evidence supports that regular consumption of PUFA may reduce obesity and overweight by altering epigenetic marks.

MATERIAL AND METHODS

A search of recent publications was carried out in human clinical trials, as well as animal model and in vitro experiments.

RESULTS

Exist a possible therapeutic effect of PUFAs on the prevention and development of obesity due to their ability to reversively modify the methylation of the promoters of genes associated with lipid metabolism and to modulate the activity of certain microRNAs.

CONCLUSIONS

A better knowledge and understanding of the PUFAs role in epigenetic regulation of obesity is possible with the current published results. The PUFAs may modulate the promotor epigenetic marks in several adipogenic genes and regulate the expression of several miRNAs.

Dietary apigenin reduces LPS-induced expression of miR-155 restoring immune balance during inflammation

SCOPE

High incidence of inflammatory diseases afflicts the increasing aging-population infringing a great health burden. Dietary flavonoids, including the flavone apigenin, are emerging as important anti-inflammatory nutraceuticals due to their health benefits, lack of adverse effects and reduced costs. MicroRNAs (miRs) play a central role in inflammation by regulating gene expression, yet how dietary ingredients affect miRs is poorly understood. The aim of this study was to identify miRs involved in the anti-inflammatory activity of apigenin and apigenin-rich diets and determine their immune regulatory mechanisms in macrophages and in vivo.

METHODS AND RESULTS

A high-throughput quantitative reverse transcriptase PCR screen of 312 miRs in macrophages revealed that apigenin reduced LPS-induced miR-155 expression. Analyses of miR-155 precursor and primary transcript indicated that apigenin regulated miR-155 transcriptionally. Apigenin-reduced expression of miR-155 led to the increase of anti-inflammatory regulators forkhead box O3a and smooth-muscle-actin and MAD-related protein 2 in LPS-treated macrophages. In vivo, apigenin or a celery-based apigenin-rich diet reduced LPS-induced expression of miR-155 and decreased tumor necrosis factor α in lungs from LPS-treated mice.

CONCLUSION

These results demonstrate that apigenin and apigenin-rich diets exert effective anti-inflammatory activity in vivo by reducing LPS-induced expression of miR-155, thereby restoring immune balance.

Potential epigenetic mechanism in non-alcoholic Fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is characterized by excessive fat accumulation in the liver. It ranges from simple steatosis to its more aggressive form, non-alcoholic steatohepatitis (NASH), which may develop into hepatic fibrosis, cirrhosis, or hepatocellular carcinoma (HCC) if it persists for a long time. However, the exact pathogenesis of NAFLD and the related metabolic disorders remain unclear. Epigenetic changes are stable alterations that take place at the transcriptional level without altering the underlying DNA sequence. DNA methylation, histone modifications and microRNA are among the most common forms of epigenetic modification. Epigenetic alterations are involved in the regulation of hepatic lipid metabolism, insulin resistance, mitochondrial damage, oxidative stress response, and the release of inflammatory cytokines, all of which have been implicated in the development and progression of NAFLD. This review summarizes the current advances in the potential epigenetic mechanism of NAFLD. Elucidation of epigenetic factors may facilitate the identification of early diagnositic biomarkers and development of therapeutic strategies for NAFLD.

Roles of proanthocyanidin rich extracts in obesity

Obesity is a multifactorial disorder involving an abnormal or excessive amount of body fat.

Nutrigenetics and nutrigenomics insights into diabetes etiopathogenesis

Diabetes mellitus (DM) is considered a global pandemic, and the incidence of DM continues to grow worldwide. Nutrients and dietary patterns are central issues in the prevention, development and treatment of this disease. The pathogenesis of DM is not completely understood, but nutrient-gene interactions at different levels, genetic predisposition and dietary factors appear to be involved. Nutritional genomics studies generally focus on dietary patterns according to genetic variations, the role of gene-nutrient interactions, gene-diet-phenotype interactions and epigenetic modifications caused by nutrients; these studies will facilitate an understanding of the early molecular events that occur in DM and will contribute to the identification of better biomarkers and diagnostics tools. In particular, this approach will help to develop tailored diets that maximize the use of nutrients and other functional ingredients present in food, which will aid in the prevention and delay of DM and its complications. This review discusses the current state of nutrigenetics, nutrigenomics and epigenomics research on DM. Here, we provide an overview of the role of gene variants and nutrient interactions, the importance of nutrients and dietary patterns on gene expression, how epigenetic changes and micro RNAs (miRNAs) can alter cellular signaling in response to nutrients and the dietary interventions that may help to prevent the onset of DM.

Flavonoids and saponins extracted from black bean (Phaseolus vulgaris L.) seed coats modulate lipid metabolism and biliary cholesterol secretion in C57BL/6 mice

Black bean (Phaseolus vulgaris L.) seed coats are a rich source of natural compounds with potential beneficial effects on human health. Beans exert hypolipidaemic activity; however, this effect has not been attributed to any particular component, and the underlying mechanisms of action and protein targets remain unknown. The aim of the present study was to identify and quantify primary saponins and flavonoids extracted from black bean seed coats, and to study their effects on lipid metabolism in primary rat hepatocytes and C57BL/6 mice. The methanol extract of black bean seed coats, characterised by a HPLC system with a UV–visible detector and an evaporative light-scattering detector and HPLC–time-of-flight/MS, contained quercetin 3-O-glucoside and soyasaponin Af as the primary flavonoid and saponin, respectively. The extract significantly reduced the expression of SREBP1c, FAS and HMGCR, and stimulated the expression of the reverse cholesterol transporters ABCG5/ABCG8 and CYP7A1 in the liver. In addition, there was an increase in the expression of hepatic PPAR-α. Consequently, there was a decrease in hepatic lipid depots and a significant increase in bile acid secretion. Furthermore, the ingestion of this extract modulated the proportion of lipids that was used as a substrate for energy generation. Thus, the results suggest that the extract of black bean seed coats may decrease hepatic lipogenesis and stimulate cholesterol excretion, in part, via bile acid synthesis.

How does the Mediterranean diet promote cardiovascular health? Current progress toward molecular mechanisms: gene-diet interactions at the genomic, transcriptomic, and epigenomic levels provide novel insights into new mechanisms

Epidemiological evidence supports a health-promoting effect of the Mediterranean Diet (MedDiet), especially in the prevention of cardiovascular diseases. These cardiovascular benefits have been attributed to a number of components of the MedDiet such as monounsaturated fatty acids, antioxidant vitamins and phytochemicals. However, the underlying mechanisms remain unknown. Likewise, little is known about the genes that define inter-individual variation in response to the MedDiet, although the TCF7L2 gene is emerging as an illustrative candidate for determining relative risk of cardiovascular events in response to the MedDiet. Moreover, omics technologies are providing evidence supporting potential mechanisms, some of them implicating epigenetics (i.e. microRNAs, methylation), and certain data suggest that some traditional foods could contribute via microRNAs possibly acting as exogenous regulators of gene expression. Future research should aim at increasing and consolidating the nutrigenetic and nutrigenomic knowledge of the MedDiet in order to provide sound, personalized and optimized nutritional recommendations.

Resveratrol and EGCG bind directly and distinctively to miR-33a and miR-122 and modulate divergently their levels in hepatic cells

Modulation of miR-33 and miR-122 has been proposed to be a promising strategy to treat dyslipidemia and insulin resistance associated with obesity and metabolic syndrome. Interestingly, specific polyphenols reduce the levels of these mi(cro)RNAs. The aim of this study was to elucidate the effect of polyphenols of different chemical structure on miR-33a and miR-122 expression and to determine whether direct binding of the polyphenol to the mature microRNAs (miRNAs) is a plausible mechanism of modulation. The effect of two grape proanthocyanidin extracts, their fractions and pure polyphenol compounds on miRNA expression was evaluated using hepatic cell lines. Results demonstrated that the effect on miRNA expression depended on the polyphenol chemical structure. Moreover, miR-33a was repressed independently of its host-gene SREBP2. Therefore, the ability of resveratrol and epigallocatechin gallate to bind miR-33a and miR-122 was measured using ¹H NMR spectroscopy. Both compounds bound miR-33a and miR-122 and differently. Interestingly, the nature of the binding of these compounds to the miRNAs was consistent with their effects on cell miRNA levels. Therefore, the specific and direct binding of polyphenols to miRNAs emerges as a new posttranscriptional mechanism by which polyphenols could modulate metabolism.

Chronic administration of proanthocyanidins or docosahexaenoic acid reverses the increase of miR-33a and miR-122 in dyslipidemic obese rats

miR-33 and miR-122 are major regulators of lipid metabolism in the liver, and their deregulation has been linked to the development of metabolic diseases such as obesity and metabolic syndrome. However, the biological importance of these miRNAs has been defined using genetic models. The aim of this study was to evaluate whether the levels of miR-122 and miR-33a in rat liver correlate with lipemia in nutritional models. For this purpose, we analyzed the levels of miRNA-33a and miR-122 in the livers of dyslipidemic cafeteria diet-fed rats and of cafeteria diet-fed rats supplemented with proanthocyanidins and/or ω-3 PUFAs because these two dietary components are well-known to counteract dyslipidemia. The results showed that the dyslipidemia induced in rats that were fed a cafeteria diet resulted in the upregulation of miR-33a and miR-122 in the liver, whereas the presence of proanthocyanidins and/or ω-3 PUFAs counteracted the increase of these two miRNAs. However, srebp2, the host gene of miR-33a, was significantly repressed by ω-3 PUFAs but not by proanthocyanidins. Liver mRNA levels of the miR-122 and miR-33a target genes, fas and pparβ/δ, cpt1a and abca1, respectively, were consistent with the expression of these two miRNAs under each condition. Moreover, the miR-33a and abca1 levels were also analyzed in PBMCs. Interestingly, the miR-33a levels evaluated in PBMCs under each condition were similar to the liver levels but enhanced. This demonstrates that miR-33a is expressed in PBMCs and that these cells can be used as a non-invasive way to reflect the expression of this miRNA in the liver. These findings cast new light on the regulation of miR-33a and miR-122 in a dyslipidemic model of obese rats and the way these miRNAs are modulated by dietary components in the liver and in PBMCs.