Vitamin D limits inflammation-linked microRNA expression in adipocytes in vitro and in vivo: A new mechanism for the regulation of inflammation by vitamin D

Dietary modulation of microRNAs in insulin resistance and type 2 diabetes

The prevalence of type 2 diabetes is increasing worldwide. Various molecular mechanisms have been proposed to interfere with the insulin signaling pathway. Recent advances in proteomics and genomics indicate that one such mechanism involves the post-transcriptional regulation of insulin signaling by microRNA (miRNA). These noncoding RNAs typically induce messenger RNA (mRNA) degradation or translational repression by interacting with the 3' untranslated region (3'UTR) of target mRNA. Dietary components and patterns, which can either enhance or impair the insulin signaling pathway, have been found to regulate miRNA expression in both in vitro and in vivo studies. This review provides an overview of the current knowledge of how dietary components influence the expression of miRNAs related to the control of the insulin signaling pathway and discusses the potential application of these findings in precision nutrition.

Inflammation-related miRNAs in obesity, CVD, and NAFLD

Obesity, cardiovascular diseases (CVD), and nonalcoholic fatty liver disease (NAFLD) pose significant worldwide health challenges, characterized by complex interplay among inflammatory pathways that underlie their development. In this review, we examine the contribution of inflammation and associated signaling molecules to the pathogenesis of these conditions, while also emphasizing the significant participation of non-coding RNAs (ncRNAs) in modulating inflammatory pathways. In the context of obesity, aberrant expression patterns of inflammatory-associated miRNAs play a contributory role in adipose tissue inflammation and insulin resistance, thereby exacerbating disturbances in metabolic homeostasis. Similarly, in CVD, dysregulated miRNA expression alters inflammatory reactions, disrupts endothelial function, and induces cardiac remodeling, thereby impacting the advancement of the disease. Moreover, in the context of NAFLD, inflammatory-associated miRNAs are implicated in mediating hepatic inflammation, lipid deposition, and fibrosis, underscoring their candidacy as promising therapeutic targets. Additionally, the competing endogenous RNA (ceRNA) network has emerged as a novel regulatory mechanism in the etiology of CVD, obesity, and NAFLD, wherein ncRNAs assume pivotal roles in facilitating communication across diverse molecular pathways. Moreover, in the concluding section, we underscored the potential efficacy of directing interventions towards inflammatory-related miRNAs utilizing herbal remedies and therapies based on exosome delivery systems as a promising strategy for ameliorating pathologies associated with inflammation in obesity, CVD, and NAFLD.

The effect of active vitamin D supplementation on body weight and composition: A meta-analysis of individual participant data

BACKGROUND & AIMS

Obesity is associated with vitamin D (VitD) deficiency. However, previous studies showed mixed effects of VitD (25-hydroxyVitD/calcidiol) supplementation on body weight. The biological actions of VitD require the hydroxylation of inactive VitD into active VitD (1.25-dihydroxyVitD/calcitriol). This step is highly regulated; therefore, supplementing with inactive VitD might not be sufficient to overcome the potential adverse health effects of VitD deficiency. The objective of this study was to conduct a systematic review and individual participant data (IPD) meta-analysis of data acquired from randomised placebo-controlled calcitriol trials (RCTs) to determine the effects of calcitriol on body weight and weight-related parameters.

METHODS

Studies were identified from MEDLINE, EMBASE, and CENTRAL databases up to January 27, 2024, and excluded those involving dialysis or cancer patients. We obtained IPD from eligible trials and assessed bias using the Cochrane Collaboration risk-of-bias tool and methodological quality using the Heyland Methodological Quality Score. The study was prospectively registered with PROSPERO (CRD42017076202).

RESULTS

Although none of the studies reported information regarding our primary objective, we obtained IPD for 411 patients, with 206 randomised to receive calcitriol and 205 to placebo. This dataset enabled us to conduct an IPD meta-analysis with 17,084 person-months of follow-up (median: 11 months). Meta-analysis showed that calcitriol does not alter body weight, BMI, waist circumference, fat mass or lean body mass compared to placebo. Adjusting for age and sex did not alter the outcomes.

CONCLUSIONS

In conclusion, this systematic review and IPD meta-analysis indicate that calcitriol does not affect body weight in normal-weight postmenopausal women and lean patients with type 1 diabetes nor in people suffering from obesity, type 2 diabetes and chronic kidney disease. Whether calcitriol lowers body weight in VitD-sufficient people with obesity remains to be elucidated.

Relationship between Vitamin D Insufficiency, Lipid Profile and Atherogenic Indices in Healthy Women Aged 18-50 Years

Although vitamin D insufficiency has been correlated with an increased risk of cardiovascular disease (CVD), there are few data on the association between 25-hydroxyvitamin D (25(OH)D) and atherogenic indices predictive of CVD. This study investigated the relationship of vitamin D status with lipid profile and atherogenic indices in adult women in Morocco. Three hundred women aged 18 to 50 years from Meknes were included. Fasting 25(OH)D and lipid concentrations were assayed by a one-step electrochemiluminescence-based immunoassay and an enzymatic method, respectively. Atherogenic indices (atherogenic index of plasma (AIP), atherogenic coefficient (AC), non-HDL cholesterol (non-HDL-C), Castelli risk indices I and II (CRI-I and II), and CHOLIndex (CI)) were calculated using conventional lipid parameters. Logistic regression models and operating characteristic curve (ROC) analysis were used to assess the relationship of the variables and estimate the threshold of 25(OH)D levels associated with high atherogenic indices. 25(OH) D below 20 ng/mL was significantly associated with an enhanced risk of hypertriglyceridemia and elevated values of AIP, AC, non-HDL-C, and CRI-I with an OR (95% CI) of 4.904 (1.856-12.959), 3.637 (2.149-6.158), 3.589 (1.673-7.700), 2.074 (1.215-3.540), and 2.481 (1.481-4.123), respectively. According to the ROC analysis, the likelihood of hypertriglyceridemia and high values of AIP, AC, non-HDL-C, and CRI-I were associated with 25(OH)D thresholds ≤15.15 ng/mL, ≤17.5 ng/mL, ≤19.8 ng/mL, ≤20.1 ng/mL, and ≤19.5 ng/mL, respectively, all p < 0.01. Based on the atherogenic indices, this study indicates that vitamin D below 20 ng/mL may increase the risk of cardiovascular disease in adult women. Additional health measures are essential to raise awareness among women and health professionals of preventing and controlling cardiovascular risk factors, particularly among young individuals.

Topical Vitamin D Prevents Bone Loss and Inflammation in a Mouse Model

There is a strong association between vitamin D levels and periodontal disease based on numerous epidemiological studies. We have previously shown that experimental deficiency of serum vitamin D in mice leads to gingival inflammation and alveolar bone loss. Treatment of cultured oral epithelial cells with the active form of vitamin D, 1,25(OH)2 vitamin D3 (1,25(OH)2D3), inhibits the extracellular growth and intracellular invasion of bacteria associated with periodontal disease. Maintenance of periodontal health may be due in part to the anti-inflammatory activities of vitamin D. Furthermore, this hormone can induce the expression of an antimicrobial peptide in cultured oral epithelial cells. We have shown that oral epithelial cells are capable of converting inactive vitamin D to the active form, suggesting that topical treatment of the oral epithelium with inactive vitamin D could prevent the development of periodontitis. We subjected mice to ligature-induced periodontitis (LIP), followed by daily treatment with inactive vitamin D or 1,25(OH)2D3. Treatment with both forms led to a reduction in ligature-induced bone loss and inflammation. Gingival tissues obtained from vitamin D-treated LIP showed production of specialized proresolving mediators (SPM) of inflammation. To examine the mechanism, we demonstrated that apical treatment of 3-dimensional cultures of primary gingival epithelial cells with vitamin D prevented lipopolysaccharide-induced secretion of proinflammatory cytokines and led to a similar production of SPM. Analysis of the oral microbiome of the mice treated with vitamin D showed significant changes in resident bacteria, which reflects a shift toward health-associated species. Together, our results show that topical treatment of oral tissues with inactive vitamin D can lead to the maintenance of periodontal health through the regulation of a healthy microbiome and the stimulation of resolution of inflammation. This strongly supports the development of a safe and effective vitamin D-based topical treatment or preventive agent for periodontal inflammation and disease.

Aging alone or combined with obesity increases white adipose tissue inflammatory status in male mice

White adipose tissue (WAT) has been recognized as a fundamental and crucial organ of interest in research focusing on inflammation during obesity or aging. WAT is also proposed as a significant component of cholecalciferol and 25-hydroxyvitamin D (25(OH)D) storage, which participates in the decrease of 25(OH)D plasma levels reported during aging and obesity. In the present study, we evaluated WAT and plasma cholecalciferol and 25(OH)D content together with inflammatory status to highlight the putative relationship between vitamin D status and inflammatory process during aging alone or combined with obesity. Circulating cholecalciferol and 25(OH)D and the stored quantity of cholecalciferol and 25(OH)D in WAT were quantified in young and old mice fed a control or obesogenic diet. The inflammation was assessed by measuring plasma inflammatory cytokines, mRNA, and microRNAs inflammatory-associated in WAT. The combination of aging and obesity decreased 25(OH)D plasma levels but did not modify circulating inflammatory markers. A cumulative effect of aging and obesity was observed in WAT, with rising mRNA inflammatory cytokines, notably Ccl5 and Tnf. Interestingly, aging and obesity-associated were also characterized by increased inflammatory microRNA expression. The inflammatory parameters in WAT were negatively correlated with the plasma 25(OH)D but positively correlated with the quantity of cholecalciferol and 25(OH)D in WAT. These results support the cumulative effect of obesity and aging in aggravation of WAT inflammation and suggest that accumulation of cholecalciferol and 25(OH)D in WAT could constitute a mechanism to counteract WAT inflammation during aging and obesity.

A 12-week double-blind randomised controlled trial investigating the effect of dietary supplementation with 5000 μg/d (125 µg/d) vitamin D in adults with asthma

Vitamin D deficiency has previously been linked to higher rates of exacerbation and reduced lung function in asthmatics. Previous randomised controlled trials investigating the effect of vitamin D supplementation have mainly focused on children with asthma. Trials involving adults have typically used bolus dosing regimens, and the main outcomes have been patient-focused without investigating underlying inflammation. The present study aimed to conduct a 12-week placebo-controlled randomised controlled trials administering a daily 5000 μg (125 µg) vitamin D3 supplement to adults with mild to moderate asthma. A total of 32 participants were randomised to receive either the 5000 μg vitamin D3 supplement or an identical matching placebo. The primary outcome of the study was lung function measured by the ratio of FEV1:FVC (effect size 2·5) with secondary outcomes including asthma symptoms and inflammatory biomarkers. There was a small but statistically significant higher increase in the mean (±sd) ratio of FEV1:FVC from baseline to post-intervention in the vitamin D group (+0·05 ± 0·06) compared with the placebo group (+0·006 ± 0·04, P = 0·04). There was no effect of the intervention on asthma control test scores, or the inflammatory biomarkers measured. There was a moderate, significant association between baseline plasma 25(OH)D concentration and baseline plasma IL-10 (r = 0·527, P = 0·005) and TNF-α (r = −0·498. P = 0·008) concentrations. A daily vitamin D3 supplement led to slightly improved lung function in adult asthmatics and may be a useful adjunct to existing asthma control strategies, particularly for individuals with suboptimal vitamin D status.

Decoding the secrets of longevity: unraveling nutraceutical and miRNA-Mediated aging pathways and therapeutic strategies

MicroRNAs (miRNAs) are short RNA molecules that are not involved in coding for proteins. They have a significant function in regulating gene expression after the process of transcription. Their participation in several biological processes has rendered them appealing subjects for investigating age-related disorders. Increasing data indicates that miRNAs can be influenced by dietary variables, such as macronutrients, micronutrients, trace minerals, and nutraceuticals. This review examines the influence of dietary factors and nutraceuticals on the regulation of miRNA in relation to the process of aging. We examine the present comprehension of miRNA disruption in age-related illnesses and emphasize the possibility of dietary manipulation as a means of prevention or treatment. Consolidating animal and human research is essential to validate the significance of dietary miRNA control in living organisms, despite the abundance of information already provided by several studies. This review elucidates the complex interaction among miRNAs, nutrition, and aging, offering valuable insights into promising areas for further research and potential therapies for age-related disorders.

The Roles of MicroRNAs in Asthma and Emerging Insights into the Effects of Vitamin D3 Supplementation

Asthma is one of the most common chronic non-communicable diseases worldwide, characterized by variable airflow limitation secondary to airway narrowing, airway wall thickening, and increased mucus resulting from chronic inflammation and airway remodeling. Current epidemiological studies reported that hypovitaminosis D is frequent in patients with asthma and is associated with worsening the disease and that supplementation with vitamin D3 improves asthma symptoms. However, despite several advances in the field, the molecular mechanisms of asthma have yet to be comprehensively understood. MicroRNAs play an important role in controlling several biological processes and their deregulation is implicated in diverse diseases, including asthma. Evidence supports that the dysregulation of miR-21, miR-27b, miR-145, miR-146a, and miR-155 leads to disbalance of Th1/Th2 cells, inflammation, and airway remodeling, resulting in exacerbation of asthma. This review addresses how these molecular mechanisms explain the development of asthma and its exacerbation and how vitamin D3 may modulate these microRNAs to improve asthma symptoms.

An Overview of Different Vitamin D Compounds in the Setting of Adiposity

A large body of research shows an association between higher body weight and low vitamin D status, as assessed using serum 25-hydroxyvitamin D concentrations. Vitamin D can be metabolised in adipose tissue and has been reported to influence gene expression and modulate inflammation and adipose tissue metabolism in vitro. However, the exact metabolism of vitamin D in adipose tissue is currently unknown. White adipose tissue expresses the vitamin D receptor and hydroxylase enzymes, substantially involved in vitamin D metabolism and efficacy. The distribution and concentrations of the generated vitamin D compounds in adipose tissue, however, are largely unknown. Closing this knowledge gap could help to understand whether the different vitamin D compounds have specific health effects in the setting of adiposity. This review summarises the current evidence for a role of vitamin D in adipose tissue and discusses options to accurately measure vitamin D compounds in adipose tissue using liquid chromatography tandem mass spectrometry (LC/MS-MS).

From the Sun to the Cell: Examining Obesity through the Lens of Vitamin D and Inflammation

Obesity affects more than one billion people worldwide and often leads to cardiometabolic chronic comorbidities. It induces senescence-related alterations in adipose tissue, and senescence is closely linked to obesity. Fully elucidating the pathways through which vitamin D exerts anti-inflammatory effects may improve our understanding of local adipose tissue inflammation and the pathogenesis of metabolic disorders. In this narrative review, we compiled and analyzed the literature from diverse academic sources, focusing on recent developments to provide a comprehensive overview of the effect of vitamin D on inflammation associated with obesity and senescence. The article reveals that the activation of the NF-κB (nuclear factor kappa B subunit 1) and NLRP3 inflammasome (nucleotide-binding domain, leucine-rich-containing, pyrin domain-containing-3) pathways through the toll-like receptors, which increases oxidative stress and cytokine release, is a common mechanism underlying inflammation associated with obesity and senescence, and it discusses the potential beneficial effect of vitamin D in alleviating the development of subclinical inflammation. Investigating the main target cells and pathways of vitamin D action in adipose tissue could help uncover complex mechanisms of obesity and cellular senescence. This review summarizes significant findings related to opportunities for improving metabolic health.

Effect of tomato, tomato-derived products and lycopene on metabolic inflammation: from epidemiological data to molecular mechanisms

The goal of this narrative review is to summarise the current knowledge and limitations related to the anti-inflammatory effects of tomato, tomato-derived products and lycopene in the context of metabolic inflammation associated to cardiometabolic diseases. The potential of tomato and tomato-derived product supplementation is supported by animal and in vitro studies. In addition, intervention studies provide arguments in favour of a limitation of metabolic inflammation. This is also the case for observational studies depicting inverse association between plasma lycopene levels and inflammation. Nevertheless, current data of intervention studies are mixed concerning the anti-inflammatory effect of tomato and tomato-derived products and are not in favour of an anti-inflammatory effect of pure lycopene in humans. From epidemiological to mechanistic studies, this review aims to identify limitations of the current knowledge and gaps that remain to be filled to improve our comprehension in contrasted anti-inflammatory effects of tomato, tomato-derived products and pure lycopene.

Vitamin D Modulates Lipid Composition of Adipocyte-Derived Extracellular Vesicles Under Inflammatory Conditions

SCOPE

Adipocyte-derived extracellular vesicles (AdEVs) convey lipids that can play a role in the energy homeostasis. Vitamin D (VD) has been shown to limit the metabolic inflammation as it decreases inflammatory markers expression in adipose tissue (AT). However, VD effect on adipocytes-derived EVs has never been investigated.

METHODS AND RESULTS

Thus, the aim of this study is to evaluate the AdEVs lipid composition by LC-MS/MS approach in 3T3-L1 cells treated with VD or/and pro-inflammatory factor (tumor necrosis factor α [TNFα]). Among all lipid species, four are highlighted (glycerolipids, phospholipids, lysophospholipids, and sphingolipids) with a differential content between small (sEVs) and large EVs (lEVs). This study also observes that VD alone modulates EV lipid species involved in membrane fluidity and in the budding of membrane. EVs treated with VD under inflammatory conditions have different lipid profiles than the control group, which is more pronounced in lEVs. Indeed, 25 lipid species are significantly modulated in lEVs, compared with only seven lipid species in sEVs.

CONCLUSIONS

This study concludes that VD, alone or under inflammatory conditions, is associated with specific lipidomic signature of sEVs and lEVs. These observations reinforce current knowledge on the anti-inflammatory effect of VD.

The Role of Vitamin D and Its Molecular Bases in Insulin Resistance, Diabetes, Metabolic Syndrome, and Cardiovascular Disease: State of the Art

In the last decade, an increasing awareness was directed to the role of Vitamin D in non-skeletal and preventive roles for chronic diseases. Vitamin D is an essential hormone in regulating calcium/phosphorous balance and in the pathogenesis of inflammation, insulin resistance, and obesity. The main forms of vitamin D, Cholecalciferol (Vitamin D3) and Ergocalciferol (Vitamin D2) are converted into the active form (1,25-dihydroxyvitamin D) thanks to two hydroxylations in the liver, kidney, pancreas, and immune cells. Some anti-inflammatory cytokines are produced at higher levels by vitamin D, while some pro-inflammatory cytokines are released at lower levels. Toll-Like Receptor (TLR) expression is increased, and a pro-inflammatory state is also linked to low levels of vitamin D. Regardless of how it affects inflammation, various pathways suggest that vitamin D directly improves insulin sensitivity and secretion. The level of vitamin D in the body may change the ratio of pro- to anti-inflammatory cytokines, which would impact insulin action, lipid metabolism, and the development and function of adipose tissue. Many studies have demonstrated an inverse relationship between vitamin D concentrations and pro-inflammatory markers, insulin resistance, glucose intolerance, metabolic syndrome, obesity, and cardiovascular disease. It is interesting to note that several long-term studies also revealed an inverse correlation between vitamin D levels and the occurrence of diabetes mellitus. Vitamin D supplementation in people has controversial effects. While some studies demonstrated improvements in insulin sensitivity, glucose, and lipid metabolism, others revealed no significant effect on glycemic homeostasis and inflammation. This review aims to provide insight into the molecular basis of the relationship between vitamin D, insulin resistance, metabolic syndrome, type 1 and 2 diabetes, gestational diabetes, and cardiovascular diseases.

Novel insights regarding the role of noncoding RNAs in diabetes

Diabetes mellitus (DM) is a group of metabolic disorders defined by hyperglycemia induced by insulin resistance, inadequate insulin secretion, or excessive glucagon secretion. In 2021, the global prevalence of diabetes is anticipated to be 10.7% (537 million people). Noncoding RNAs (ncRNAs) appear to have an important role in the initiation and progression of DM, according to a growing body of research. The two major groups of ncRNAs implicated in diabetic disorders are miRNAs and long noncoding RNAs. miRNAs are single-stranded, short (17–25 nucleotides), ncRNAs that influence gene expression at the post-transcriptional level. Because DM has reached epidemic proportions worldwide, it appears that novel diagnostic and therapeutic strategies are required to identify and treat complications associated with these diseases efficiently. miRNAs are gaining attention as biomarkers for DM diagnosis and potential treatment due to their function in maintaining physiological homeostasis via gene expression regulation. In this review, we address the issue of the gradually expanding global prevalence of DM by presenting a complete and up-to-date synopsis of various regulatory miRNAs involved in these disorders. We hope this review will spark discussion about ncRNAs as prognostic biomarkers and therapeutic tools for DM. We examine and synthesize recent research that used novel, high-throughput technologies to uncover ncRNAs involved in DM, necessitating a systematic approach to examining and summarizing their roles and possible diagnostic and therapeutic uses.

Vitamin D/vitamin D receptor pathway in non-alcoholic fatty liver disease

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide, but underlying mechanisms are not fully understood. In recent years, a growing body of evidence has emphasized the therapeutic role of vitamin D in NAFLD, but the specific mechanism remains to be investigated.

AREAS COVERED

This review summarized the roles of vitamin D/VDR (vitamin D receptor) pathway in different types of liver cells (such as hepatocytes, hepatic stellate cells, liver macrophages, T lymphocytes, and other hepatic immune cells) in case of NAFLD. Meanwhile, the effects of pathways in the gut-liver axis, adipose tissue-liver axis, and skeletal muscle-liver axis on the development of NAFLD were further reviewed. Relevant literature was searched on PubMed for the writing of this review.

EXPERT OPINION

The precise regulation of regional vitamin D/VDR signaling pathway based on cell-specific or tissue-specific function will help clarify the potential mechanism of vitamin D in NAFLD, which may provide new therapeutic targets to improve the safety and efficacy of vitamin D based drugs.

Epigenetic regulation of vitamin D deficiency

Tweetable abstract Epigenetic insights into vitamin D deficiency, a global health concern, are described here. This editorial illuminates the role of epigenetic mechanisms in understanding the molecular basis of vitamin D deficiency, shedding light on precision medicine.

Psychological Outcomes and Quality of Life of Fibromyalgia Patients with Vitamin D Supplementation-A Meta-Analysis

The efficacy of current pharmaceutical treatments for fibromyalgia are limited. Vitamin D has shown promise in relieving pain. However, there is a lack of comprehensive analysis of psychological outcomes with vitamin D supplementation in fibromyalgia. This study aimed to investigate the impact of vitamin D supplementation on psychological outcomes and quality of life in fibromyalgia patients, given the unmet clinical need for effective treatment options. A meta-analysis of randomized controlled trials comparing vitamin D to placebo and prospective studies examining changes before and after vitamin D supplementation for patients with fibromyalgia was conducted to evaluate the effects of vitamin D on psychological outcomes, quality of life, and pain scores in patients with fibromyalgia. Databases were searched for relevant articles published from earliest available date to October 31, 2022. (PROSPERO number, CRD42022369889). We included 8 trials with a total of 694 participants and found that vitamin D supplementation had significant positive effects on physical function (standard mean differences (SMD) = 0.44, 95% CI = [0.10, 0.77 ]), role limitations due to emotional health (SMD = 0.57, 95% CI = [0.32, 0.82]), social function (SMD = 0.50, 95% CI = [0.08, 0.93]), and general health (SMD = 0.36, 95% CI = [0.11, 0.61]). Improvement of the Fibromyalgia Impact Questionnaire (FIQ) scores was noted (SMD = -0.414, 95% CI = [-0.808, -0.021]), but not on the Visual Analog Scale (VAS) (SMD = -0.15, 95% CI = [-0.771, 0.471]) and the Beck's Depression Inventory (BDI) scores (SMD = -0.456, 95% CI = [-1.27, 0.30]). In conclusion, vitamin D supplementation might be an alternative option for improvement of psychological outcomes and quality of life in patients with fibromyalgia.

Oxidative Stress and Epigenetics: miRNA Involvement in Rare Autoimmune Diseases

Autoimmune diseases (ADs) such as Sjögren’s syndrome, Kawasaki disease, and systemic sclerosis are characterized by chronic inflammation, oxidative stress, and autoantibodies, which cause joint tissue damage, vascular injury, fibrosis, and debilitation. Epigenetics participate in immune cell proliferation and differentiation, which regulates the development and function of the immune system, and ultimately interacts with other tissues. Indeed, overlapping of certain clinical features between ADs indicate that numerous immunologic-related mechanisms may directly participate in the onset and progression of these diseases. Despite the increasing number of studies that have attempted to elucidate the relationship between miRNAs and oxidative stress, autoimmune disorders and oxidative stress, and inflammation and miRNAs, an overall picture of the complex regulation of these three actors in the pathogenesis of ADs has yet to be formed. This review aims to shed light from a critical perspective on the key AD-related mechanisms by explaining the intricate regulatory ROS/miRNA/inflammation axis and the phenotypic features of these rare autoimmune diseases. The inflamma-miRs miR-155 and miR-146, and the redox-sensitive miR miR-223 have relevant roles in the inflammatory response and antioxidant system regulation of these diseases. ADs are characterized by clinical heterogeneity, which impedes early diagnosis and effective personalized treatment. Redox-sensitive miRNAs and inflamma-miRs can help improve personalized medicine in these complex and heterogeneous diseases.

Vitamin D modulates inflammatory response of DENV-2-infected macrophages by inhibiting the expression of inflammatory-liked miRNAs

Dengue disease caused by dengue virus (DENV) infection is the most common vector-borne viral disease worldwide. Currently, no treatment is available to fight dengue symptoms. We and others have demonstrated the antiviral and immunomodulatory properties of VitD3 as a possible therapy for DENV infection. MicroRNAs (miRNAs) are small non-coding RNAs responsible for the regulation of cell processes including antiviral defense. Previous transcriptomic analysis showed that VitD3 regulates the expression of genes involved in stress and immune response by inducing specific miRNAs. Here, we focus on the effects of VitD3 supplementation in the regulation of the expression of inflammatory-liked miR-182-5p, miR-130a-3p, miR125b-5p, miR146a-5p, and miR-155-5p during DENV-2 infection of monocyte-derived macrophages (MDMs). Further, we evaluated the effects of inhibition of these miRNAs in the innate immune response. Our results showed that supplementation with VitD3 differentially regulated the expression of these inflammatory miRNAs. We also observed that inhibition of miR-182-5p, miR-130a-3p, miR-125b-5p, and miR-155-5p, led to decreased production of TNF-α and TLR9 expression, while increased the expression of SOCS-1, IFN-β, and OAS1, without affecting DENV replication. By contrast, over-expression of miR-182-5p, miR-130a-3p, miR-125b-5p, and miR-155-5p significantly decreased DENV-2 infection rates and also DENV-2 replication in MDMs. Our results suggest that VitD3 immunomodulatory effects involve regulation of inflammation-linked miRNAs expression, which might play a key role in the inflammatory response during DENV infection.

The Impact of Diet and Physical Activity on Psoriasis: A Narrative Review of the Current Evidence

Psoriasis is an inflammatory disease with strong genetic links and numerous features of autoimmunity that are also influenced by environment and lifestyle, including nutritional factors and physical activity (PA), with regards to the condition of patients. Recent reports in the field of nutrigenomics indicate a significant impact of nutrients in modulating microRNAs. However, few studies have evaluated the effect of nutritional systems and PA on treating psoriasis. This narrative review updates information regarding the current dietary recommendations for individuals with psoriasis and discusses the role of diet and PA in psoriasis prevention and treatment. Application of nutrigenetics in psoriasis therapy is also discussed. The PubMed and Google Scholar databases were searched using the MeSH terms for "nutrigenomics", "dietetics", "diet therapy", "diet", "physical activity", and "exercise" in conjunction with the MeSH terms for "psoriasis" and "dermatology". Evidence has shown that patients with psoriasis should have a personalized anti-inflammatory diet. Psoriasis patients are less physically active; most performed exercises of low-to-moderate intensity and were less likely to undertake regular exercise. Identifying nutrigenomic discoveries and the current lifestyle interventions associated with psoriasis can help physicians and physical therapists develop educational programs to manage and protect against the disease.

The Role of Maternal Vitamin D Deficiency in Offspring Obesity: A Narrative Review

Currently, vitamin D (VD) deficiency during pregnancy is widespread globally, causing unfavorable pregnancy outcomes for both mothers and infants for a longer time than expected, based on the Developmental Origins of Health and Disease (DOHaD) theory. As VD plays a key role in maintaining normal glucose and lipid metabolism, maternal VD deficiency may lead to obesity and other obesity-related diseases among offspring later in life. This review mainly focuses on the effect of maternal VD deficiency on offspring lipid metabolism, reviewing previous clinical and animal studies to determine the effects of maternal VD deficit on offspring obesity and potential mechanisms involved in the progression of offspring obesity. Emerging clinical evidence shows that a low VD level may lead to abnormal growth (either growth restriction or largeness for gestational age) and lipid and glucose metabolism disorders in offspring. Here, we also outline the link between maternal VD deficiency and life-long offspring effects, including the disorder of adipogenesis, the secretion of adipocytokines (including leptin, resistin, and adiponectin), activated systemic inflammation, increased oxidative reactions in adipose tissue, insulin resistance, and abnormal intestinal gut microbiota. Thus, there is an urgent need to take active steps to address maternal VD deficiency to relieve the global burden of obesity.

Double blind control trial of vitamin D fortified milk on the expression of lncRNAs and adiponectin for patients with metabolic syndrome

BACKGROUND

Metabolic syndrome (Mets) is a common metabolic disorder in which hypoadiponectinemia is one of the consequences for the body caused by inflammation, and vitamin D may help improve inflammatory symptoms. LncRNAs (long non-coding RNA) play several different regulatory roles in the body. The goal of this study was to see how adding vitamin D to milk affected the levels of adiponectin and inflammatory lncRNAs in the serum of people with Mets.

METHODS

This clinical trial was conducted on staff and students between the ages of 30 and 50 at Mashhad University of Medical Sciences and met the International Diabetes Federation's criteria for Mets. Eighty-two Mets were assigned randomly to one of two groups for ten weeks: fortified milk (FM) with 1500 IU vitamin D or non-fortified milk (NFM). Total RNA was extracted from both frozen clinical samples using Trizol reagent. APQ AS and MALAT1 lncRNA gene expression were measured by Real-Time PCR.

RESULTS

Serum adiponectin levels in the FM group increased significantly compared to the NFM group (p = 0.01). Also, the expression of APQ AS and MALAT1 genes decreased after ten weeks, which showed a significant decrease in APQ AS (p = 0.036).

CONCLUSION

As in FM, vitamin D may have anti-inflammatory effects and increase adiponectin levels in people with Mets via decreasing APQ AS gene expression.

Vitamin-D ameliorates sepsis-induced acute lung injury via augmenting miR-149-5p and downregulating ER stress

Acute lung injury is a life-threatening medical problem induced by sepsis or endotoxins and may be associated with enhanced Endoplasmic reticulum stress (ER stress). Vitamin-D (Vit-D) possesses an anti-inflammatory effect; however, this specific mechanism on acute lung injury is still unknown. Here we scrutinize the mechanism of Vit-D on Acute lung injury (ALI) models and explored the Vit-D augmented miRNA's role in regulating the ER stress pathway in ALI. Sepsis was induced by CLP, and Endotoxemia was caused by lipopolysaccharide (LPS). We found that Vit-D alleviates pulmonary edema, improves lung histoarchitecture, infiltration of neutrophils, endothelial barrier in mice, and improves ER stress markers Activating Transcription Factor 6 (ATF6) and CHOP (C/EBP Homologous Protein) expression elevated by CLP/LPS induce ALI. Vit-D decreases the nitric oxide production and ATF6 in macrophages induced by LPS. Vit-D augments miR (miR-149-5p) in LPS-induce macrophages, CLP, and LPS-induced ALI models. Vit-D enhanced miRNA-149-5p when overexpressed, inhibited ER-specific ATF6 inflammatory pathway in LPS-stimulated macrophages, and improved histoarchitecture of the lung in LPS/CLP-induced mice models. This vitro and vivo studies demonstrate that Vit-D could improve ALI induced by CLP/LPS. In this regard, miR-149-5p may play a crucial role in vitamin-D inhibiting LPS/CLP induce ALI. The mechanism might be an association of increased miR-149-5p and its regulated gene target ATF6, and downstream CHOP proteins were suppressed. Thus, these findings demonstrate that the anti-inflammatory effect of Vit-D is achieved by augmentation of miRNA-149-5p expression, which may be a key physiologic mediator in the prevention and treatment of ALI.

MicroRNA-150 (miR-150) and Diabetic Retinopathy: Is miR-150 Only a Biomarker or Does It Contribute to Disease Progression?

Diabetic retinopathy (DR) is a chronic disease associated with diabetes mellitus and is a leading cause of visual impairment among the working population in the US. Clinically, DR has been diagnosed and treated as a vascular complication, but it adversely impacts both neural retina and retinal vasculature. Degeneration of retinal neurons and microvasculature manifests in the diabetic retina and early stages of DR. Retinal photoreceptors undergo apoptosis shortly after the onset of diabetes, which contributes to the retinal dysfunction and microvascular complications leading to vision impairment. Chronic inflammation is a hallmark of diabetes and a contributor to cell apoptosis, and retinal photoreceptors are a major source of intraocular inflammation that contributes to vascular abnormalities in diabetes. As the levels of microRNAs (miRs) are changed in the plasma and vitreous of diabetic patients, miRs have been suggested as biomarkers to determine the progression of diabetic ocular diseases, including DR. However, few miRs have been thoroughly investigated as contributors to the pathogenesis of DR. Among these miRs, miR-150 is downregulated in diabetic patients and is an endogenous suppressor of inflammation, apoptosis, and pathological angiogenesis. In this review, how miR-150 and its downstream targets contribute to diabetes-associated retinal degeneration and pathological angiogenesis in DR are discussed. Currently, there is no effective treatment to stop or reverse diabetes-caused neural and vascular degeneration in the retina. Understanding the molecular mechanism of the pathogenesis of DR may shed light for the future development of more effective treatments for DR and other diabetes-associated ocular diseases.

Investigating the Role of Circulating miRNAs as Biomarkers in Colorectal Cancer: An Epidemiological Systematic Review

Colorectal cancer (CRC) is one of the most common cancers worldwide. Primary and secondary preventions are key to reducing the global burden. MicroRNAs (miRNAs) are a group of small non-coding RNA molecules, which seem to have a role either as tumor suppressor genes or oncogenes and to be related to cancer risk factors, such as obesity and inflammation. We conducted a systematic review and meta-analysis to identify circulating miRNAs related to CRC diagnosis that could be selected as biomarkers in a meet-in-the-middle analysis. Forty-four studies were included in the systematic review and nine studies in the meta-analysis. The pooled sensitivity and specificity of miR-21 for CRC diagnosis were 77% (95% CI: 69–84) and 82% (95% CI: 70–90), respectively, with an AUC of 0.86 (95% CI: 0.82–0.88). Several miRNAs were found to be dysregulated, distinguishing patients with CRC from healthy controls. However, little consistency was present across the included studies, making it challenging to identify specific miRNAs, which were consistently validated. Understanding the mechanisms by which miRNAs become biologically embedded in cancer initiation and promotion may help better understand cancer pathways to develop more effective prevention strategies and therapy approaches.

Recent insights into vitamin D, adipocyte, and adipose tissue biology

Several studies bring strong evidence for an active role of vitamin D and its metabolites in physiological adipocyte and adipose tissue processes in adulthood. This role includes effects of vitamin D on key adipose tissue and adipocyte biology parameters, including adipogenesis, energy metabolism, and inflammation. Interestingly, recent data also point to a role of maternal vitamin D deficiency in adipocyte and adipose tissue metabolic programming in offspring. This review summarizes the current state of knowledge on the biological effect of vitamin D on adipocyte/adipose tissue physiology.

Maternal Vitamin D Deficiency in Mice Increases White Adipose Tissue Inflammation in Offspring

Vitamin D is acknowledged to play an important biological and metabolic role in adipose tissue, which is also the main storage site for this vitamin. Its anti-inflammatory effect in adipocytes and adipose tissue has notably been highlighted in adult mice. This vitamin is also crucial during fetal development since maternal vitamin D deficiency is suspected to program future metabolic disorders. Based on these observations, the aim of this study was to evaluate the consequences of maternal vitamin D deficiency (VDD) on white adipose tissue inflammation in adult offspring fed with normal or obesogenic diet (high-fat diet). White adipose tissue morphology, RNA and miRNA expression profiles, and signaling pathways were studied in adult males and females. In males, a HF diet coupled with maternal VDD increased expression of RNA and miRNA linked to inflammation leading to over-representation of inflammatory pathways. Interestingly, genomic and epigenetic profiles were associated with activation of the NF-kB signaling pathway and adiposity index. In females, no major modulation of inflammatory pathways was observed under VDD, contrarily to males. We concluded that maternal VDD coupled with HF diet activated inflammatory pathway in adipose tissue of the offspring, in a sex-dependent manner. Such activation is strongly related to activation of NF-kB signaling and increased adiposity only in males.

Vitamin D and Obesity/Adiposity—A Brief Overview of Recent Studies

Observational studies classically find an inverse relationship between human plasma 25-hydroxyvitamin D concentration and obesity. However, interventional and genetic studies have failed to provide clear conclusions on the causal effect of vitamin D on obesity/adiposity. Likewise, vitamin D supplementation in obese rodents has mostly failed to improve obesity parameters, whereas several lines of evidence in rodents and prospective studies in humans point to a preventive effect of vitamin D supplementation on the onset of obesity. Recent studies investigating the impact of maternal vitamin D deficiency in women and in rodent models on adipose tissue biology programming in offspring further support a preventive metabolically driven effect of vitamin D sufficiency. The aim of this review is to summarize the state of the knowledge on the relationship between vitamin D and obesity/adiposity in humans and in rodents and the impact of maternal vitamin D deficiency on the metabolic trajectory of the offspring.

Dietary Acid Load Modulation of Asthma-Related miRNAs in the Exhaled Breath Condensate of Children

Individual nutrients and bioactive compounds have been implicated in the expression of microRNAs (miRNAs), which are related to inflammation and asthma. However, evidence about the impact of diet is scarce. Therefore, we aimed to assess the association between dietary acid load and asthma-related miRNA in the exhaled breath condensate (EBC) of school-aged children. This cross-sectional analysis included 150 participants aged 7 to 12 years (52% girls) from a nested case–control study, which randomly selected 186 children attending 71 classrooms from 20 public schools located in city of Porto, Portugal. Dietary data were collected by one 24 h-recall questionnaire. Dietary acid load was assessed using the potential renal acid load (PRAL) and net endogenous acid production (NEAP) scores. Based on previous studies, eleven asthma-related miRNAs were chosen and analyzed in EBC by reverse transcription-quantitative real-time PCR. PRAL, NEAP and miRNAs were categorized as high or low according to the median. Logistic regression models were performed to assess the association between dietary acid load scores and miRNAs. Children in high dietary acid load groups (PRAL ≥ 14.43 and NEAP ≥ 55.79 mEq/day) have significantly increased odds of having high miR-133a-3p levels. In conclusion, higher dietary acid loads possibly modulate asthma-related miRNAs of school-aged children.

NAFLD and Vitamin D: Evidence for Intersection of MicroRNA Regulated Pathways

Non-alcoholic fatty liver disease (NAFLD) is now the most common cause of chronic liver disease, worldwide. The molecular pathogenesis of NAFLD is complex, involving numerous signalling molecules including microRNAs (miRNAs). Dysregulation of miRNA expression is associated with hepatic inflammation, fibrosis and hepatocellular carcinoma. Although miRNAs are also critical to the cellular response to vitamin D, mediating regulation of the vitamin D receptor (VDR) and vitamin D’s anticancer effects, a role for vitamin D regulated miRNAs in NAFLD pathogenesis has been relatively unexplored. Therefore, this review aimed to critically assess the evidence for a potential subset of miRNAs that are both dysregulated in NAFLD and modulated by vitamin D. Comprehensive review of 89 human studies identified 25 miRNAs found dysregulated in more than one NAFLD study. In contrast, only 17 studies, including a protocol for a trial in NAFLD, had examined miRNAs in relation to vitamin D status, response to supplementation, or vitamin D in the context of the liver. This paper summarises these data and reviews the biological roles of six miRNAs (miR-21, miR-30, miR-34, miR-122, miR-146, miR-200) found dysregulated in multiple independent NAFLD studies. While modulation of miRNAs by vitamin D has been understudied, integrating the data suggests seven vitamin D modulated miRNAs (miR-27, miR-125, miR-155, miR-192, miR-223, miR-375, miR-378) potentially relevant to NAFLD pathogenesis. Our summary tables provide a significant resource to underpin future hypothesis-driven research, and we conclude that the measurement of serum and hepatic miRNAs in response to vitamin D supplementation in larger trials is warranted.

Vitamin D status is favorably associated with the cardiovascular risk factors in adults with obesity

BACKGROUND & AIMS

Previous investigations have been indicated that vitamin D deficiency is an amendable risk for cardiovascular disease (CVD) in the general populations. Limited data is available concerning the relationship of vitamin D status and risk factors of CVD in the individuals with obesity and the existing data are highly controversial. We investigated whether serum vitamin D situation is related to multiple traditional CVD risk factors in Iranian obese subjects.

METHODS

A cross-sectional study was done among 214 Iranian adults with obesity (94 males and 120 females) aged 20-60 years, who attended the specialized outpatient clinics in Zabol city. Participants were categorized as vitamin D sufficient, insufficient, and deficient according to their serum 25(OH)D concentrations. Afterward, the presence of hypercholesterolemia, hypertriglyceridemia, low high-density lipoprotein cholesterol (HDL-C), high low-density lipoprotein cholesterol (LDL-C) as well as diabetes, hypertension, and high serum concentrations of high-sensitivity C-reactive protein (hs-CRP) as CVD risk factors were evaluated in the participants.

RESULTS

There was a noticeable regular trend regarding hypercholesterolemia (p = 0.008), high LDL-C (p = 0.024), hypertension (p = 0.021), and high hs-CRP (p < 0.0001) across various categories of vitamin D status. In adjusted model, vitamin D-deficient subjects were at higher risk for having hypercholesterolemia (OR: 3.22, p = 0.031), high LDL-C (OR: 2.37, p = 0.047), hypertension (OR: 2.32, p = 0.042), and high hs-CRP (OR: 5.49, p = 0.001) than ones with sufficient vitamin D status.

CONCLUSIONS

Vitamin D deficiency in obese subjects was found to be strongly related to higher risk of unfavorable lipid profile, hypertension, and high hs-CRP.

Association of vitamin D status and cardio-metabolic risk factors in children and adolescents: the CASPIAN-V study

BACKGROUND

Metabolic syndrome (MetS) starts from early life and is one of the important underlying factors for non-communicable diseases (NCDs) in adulthood. Controversial evidence exists on the role of vitamin D deficiency in increasing the risk of pediatric MetS.

OBJECTIVE

This study aimed to assess the relationship between vitamin D level with MetS and its components in children and adolescents.

METHODS

This nationwide cross-sectional study was performed as part of a surveillance program in Iran. Participants were 2596 students, aged 7 to 18 years, living in 30 provinces. In addition to filling questionnaires, a physical examination was conducted, and blood samples were collected. The serum concentration of 25-hydroxy vitamin D (25(OH)D) was measured using the direct competitive immunoassay chemiluminescence method.

RESULTS

2596 students with a mean age of 12.2 y (55.1% boys) were recruited. Prevalence of vitamin D deficiency and insufficiency in participants was 10.6% (n = 276), and 60.5% (n = 1570), respectively. The prevalence of MetS was higher in the vitamin D deficient group. Students with deficient vitamin D levels had higher odds of MetS (OR: 4.25, 95%CI: 2.26-7.98), abdominal obesity (OR: 2.24, 95%CI: 1.61-3.12), low HDL-C (OR: 1.65, 95%CI: 1.18-2.30) and high fasting blood sugar (OR: 2.56, 95%CI: 1.43-4.57) in comparison to those with sufficient level of vitamin D.

CONCLUSION

Vitamin D deficiency was associated with increased odds of MetS and its components in the Iranian pediatric population. These findings underscore the importance of prevention and control of vitamin D deficiency in preventative programs against NCDs.

Influence of the Bioactive Diet Components on the Gene Expression Regulation

Diet bioactive components, in the concept of nutrigenetics and nutrigenomics, consist of food constituents, which can transfer information from the external environment and influence gene expression in the cell and thus the function of the whole organism. It is crucial to regard food not only as the source of energy and basic nutriments, crucial for living and organism development, but also as the factor influencing health/disease, biochemical mechanisms, and activation of biochemical pathways. Bioactive components of the diet regulate gene expression through changes in the chromatin structure (including DNA methylation and histone modification), non-coding RNA, activation of transcription factors by signalling cascades, or direct ligand binding to the nuclear receptors. Analysis of interactions between diet components and human genome structure and gene activity is a modern approach that will help to better understand these relations and will allow designing dietary guidances, which can help maintain good health.

Combined Beneficial Effect of Voluntary Physical Exercise and Vitamin D Supplementation in Diet-induced Obese C57BL/6J Mice

PURPOSE

Physical exercise (PE) combined with nutritional approaches has beneficial effects that are widely advocated to improve metabolic health. Here we used voluntary PE together with vitamin D (VD) supplementation, which has already shown beneficial effects in primary and tertiary prevention in obese mice models, to study their combined additive effects on body weight management, glucose homeostasis, metabolic inflammation, and liver steatosis as key markers of metabolic health.

METHODS

Ten-week-old male C57BL/6J mice were fed a high-fat/sucrose (HFS) diet for 10 wk, then assigned to a 15-wk intervention period with PE, VD supplementation, or both PE and VD supplementation. Morphological, histological, and molecular phenotype data were characterized.

RESULTS

The HFS-induced increases in body mass, adiposity, and adipocyte hypertrophy were improved by PE but not by VD supplementation. The HFS-induced inflammation (highlighted by chemokines mRNA levels) in inguinal adipose tissue was decreased by PE and/or VD supplementation. Furthermore, the intervention combining PE and VD showed additive effects on restoring insulin sensitivity and improving hepatic steatosis, as demonstrated through a normalization of size and number of hepatic lipid droplets and triglyceride content and a significant molecular-level decrease in the expression of genes coding for key enzymes in hepatic de novo lipogenesis.

CONCLUSIONS

Taken together, our data show beneficial effects of combining PE and VD supplementation on obesity-associated comorbidities such as insulin resistance and hepatic disease in mice. This combined exercise-nutritional support strategy could prove valuable in obesity management programs.

MicroRNA: A mediator of diet-induced cardiovascular protection

Diets containing nutrients such as polyunsaturated fatty acids, polyphenols, or vitamins have been shown to have cardiovascular benefits. Micro (mi)RNAs are fundamental regulators of gene expression and function in the cardiovascular system. Diet-induced cardiovascular benefits are associated with changes in endogenous expression of miRNAs in the cardiovascular system. In addition, emerging studies have shown that miRNAs present in the food can be transported in the circulation to tissues. These exogenous miRNAs may also affect cardiovascular function contributing to the diet-induced benefits. This review discusses the emerging role of both endogenous and exogenous miRNAs as mediators of diet-induced cardiovascular protection. Understanding the mechanisms of diet-mediated actions through modulation of miRNA may provide a potential strategy for new therapies.

Effects of Calcium and Vitamin D Co-supplementation on the Lipid Profile: A Systematic Review and Meta-analysis

PURPOSE

Calcium and vitamin D co-supplementation is common and widely used, but randomized, controlled trials (RCTs) have yielded inconclusive results concerning its impact on the serum lipid profile.

METHODS

A comprehensive literature search of Medline, Web of Science, Scopus, Embase, Cochrane Central Register of Controlled Trials, and clinical trial registry databases was conducted to identify placebo-controlled RCTs that were published through September 2020 and that evaluated the impact of calcium and vitamin D co-supplementation on total cholesterol (TC), triglycerides (TGs), low- and very-low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol (HDL-C). Standardized mean differences (SMDs) were pooled using random-effects meta-analysis models.

FINDINGS

Thirteen studies in a total of 2304 participants met the inclusion criteria. Calcium and vitamin D co-supplementation was associated with significant reductions in both TC (SMD, -0.81; 95% CI, -1.35 to -0.27; I² = 94.6%) and TGs (SMD, -0.50; 95% CI, -0.91 to -0.08; I² = 91.5%), and with a significant increase in HDL-C (SMD, 1.22; 95% CI, 0.60 to 1.83; I² = 95.4%). However, calcium and vitamin D co-supplementation were not found to be associated with significantly decreased low-density lipoprotein cholesterol (SMD, -0.39; 95% CI, -0.78 to 0.01; I² = 90.1%) or very-low-density lipoprotein cholesterol (SMD, -0.01; 95% CI, -0.70 to 0.69; I² = 82.3%).

IMPLICATIONS

The findings from the present systematic review and meta-analysis suggest that calcium and vitamin D co-supplementation has a beneficial effect on TC, TG, and HDL-C. Larger-scale, well-designed RCTs are needed to clarify the effect of calcium and vitamin D co-supplementation on all lipid-profile components.

The Role of miR-155 in Nutrition: Modulating Cancer-Associated Inflammation

Nutrition plays an important role in overall human health. Although there is no direct evidence supporting the direct involvement of nutrition in curing disease, for some diseases, good nutrition contributes to disease prevention and our overall well-being, including energy level, optimum internal function, and strength of the immune system. Lately, other major, but more silent players are reported to participate in the body’s response to ingested nutrients, as they are involved in different physiological and pathological processes. Furthermore, the genetic profile of an individual is highly critical in regulating these processes and their interactions. In particular, miR-155, a non-coding microRNA, is reported to be highly correlated with such nutritional processes. In fact, miR-155 is involved in the orchestration of various biological processes such as cellular signaling, immune regulation, metabolism, nutritional responses, inflammation, and carcinogenesis. Thus, this review aims to highlight those critical aspects of the influence of dietary components on gene expression, primarily on miR-155 and its role in modulating cancer-associated processes.

Vitamin D: Not Just Bone Metabolism but a Key Player in Cardiovascular Diseases

Vitamin D is the first item of drug expenditure for the treatment of osteoporosis. Its deficiency is a condition that affects not only older individuals but also young people. Recently, the scientific community has focused its attention on the possible role of vitamin D in the development of several chronic diseases such as cardiovascular and metabolic diseases. This review aims to highlight the possible role of vitamin D in cardiovascular and metabolic diseases. In particular, here we examine (1) the role of vitamin D in diabetes mellitus, metabolic syndrome, and obesity, and its influence on insulin secretion; (2) its role in atherosclerosis, in which chronic vitamin D deficiency, lower than 20 ng/mL (50 nmol/L), has emerged among the new risk factors; (3) the role of vitamin D in essential hypertension, in which low plasma levels of vitamin D have been associated with both an increase in the prevalence of hypertension and diastolic hypertension; (4) the role of vitamin D in peripheral arteriopathies and aneurysmal pathology, reporting that patients with peripheral artery diseases had lower vitamin D values than non-suffering PAD controls; (5) the genetic and epigenetic role of vitamin D, highlighting its transcriptional regulation capacity; and (6) the role of vitamin D in cardiac remodeling and disease. Despite the many observational studies and meta-analyses supporting the critical role of vitamin D in cardiovascular physiopathology, clinical trials designed to evaluate the specific role of vitamin D in cardiovascular disease are scarce. The characterization of the importance of vitamin D as a marker of pathology should represent a future research challenge.

Obesity, oxidative DNA damage and vitamin D as predictors of genomic instability in children and adolescents

BACKGROUND/OBJECTIVES

Epidemiological evidence indicates obesity in childhood and adolescence to be an independent risk factor for cancer and premature mortality in adulthood. Pathological implications from excess adiposity may begin early in life. Obesity is concurrent with a state of chronic inflammation, a well-known aetiological factor for DNA damage. In addition, obesity has been associated with micro-nutritional deficiencies. Vitamin D has attracted attention for its anti-inflammatory properties and role in genomic integrity and stability. The aim of this study was to determine a novel approach for predicting genomic instability via the combined assessment of adiposity, DNA damage, systemic inflammation, and vitamin D status.

SUBJECTS/METHODS

We carried out a cross-sectional study with 132 participants, aged 10-18, recruited from schools and paediatric obesity clinics in London. Anthropometric assessments included BMI Z-score, waist and hip circumference, and body fat percentage via bioelectrical impedance. Inflammation and vitamin D levels in saliva were assessed by enzyme-linked immunosorbent assay. Oxidative DNA damage was determined via quantification of 8-hydroxy-2'-deoxyguanosine in urine. Exfoliated cells from the oral cavity were scored for genomic instability via the buccal cytome assay.

RESULTS

As expected, comparisons between participants with obesity and normal range BMI showed significant differences in anthropometric measures (p < 0.001). Significant differences were also observed in some measures of genomic instability (p < 0.001). When examining relationships between variables for all participants, markers of adiposity positively correlated with acquired oxidative DNA damage (p < 0.01) and genomic instability (p < 0.001), and negatively correlated with vitamin D (p < 0.01). Multiple regression analyses identified obesity (p < 0.001), vitamin D (p < 0.001), and oxidative DNA damage (p < 0.05) as the three significant predictors of genomic instability.

CONCLUSIONS

Obesity, oxidative DNA damage, and vitamin D deficiency are significant predictors of genomic instability. Non-invasive biomonitoring and predictive modelling of genomic instability in young patients with obesity may contribute to the prioritisation and severity of clinical intervention measures.

Epigenetic signatures underlying inflammation: an interplay of nutrition, physical activity, metabolic diseases, and environmental factors for personalized nutrition

AIM AND OBJECTIVE

Emerging translational evidence suggests that epigenetic alterations (DNA methylation, miRNA expression, and histone modifications) occur after external stimuli and may contribute to exacerbated inflammation and the risk of suffering several diseases including diabetes, cardiovascular diseases, cancer, and neurological disorders. This review summarizes the current knowledge about the harmful effects of high-fat/high-sugar diets, micronutrient deficiencies (folate, manganese, and carotenoids), obesity and associated complications, bacterial/viral infections, smoking, excessive alcohol consumption, sleep deprivation, chronic stress, air pollution, and chemical exposure on inflammation through epigenetic mechanisms. Additionally, the epigenetic phenomena underlying the anti-inflammatory potential of caloric restriction, n-3 PUFA, Mediterranean diet, vitamin D, zinc, polyphenols (i.e., resveratrol, gallic acid, epicatechin, luteolin, curcumin), and the role of systematic exercise are discussed.

METHODS

Original and review articles encompassing epigenetics and inflammation were screened from major databases (including PubMed, Medline, Science Direct, Scopus, etc.) and analyzed for the writing of the review paper.

CONCLUSION

Although caution should be exercised, research on epigenetic mechanisms is contributing to understand pathological processes involving inflammatory responses, the prediction of disease risk based on the epigenotype, as well as the putative design of therapeutic interventions targeting the epigenome.

Calcitriol alleviates ethanol-induced hepatotoxicity via AMPK/mTOR-mediated autophagy

Excessive ethanol consumption causes cellular damage, leading to fetal alcohol syndrome and alcohol liver diseases, which are frequently seen with vitamin D (VD) deficiency. A great deal of progress has been achieved in the mechanisms of ethanol-induced hepatocyte damage. However, there are limited intervention means to reduce or rescue hepatocytes damage caused by ethanol. On the basis of our preliminary limited screen process, calcitriol showed a positive effect on protecting hepatocyte viability. Therefore, the molecular basis is worth elucidating. We found that calcitriol pretreatment markedly improved the cell viability, decreased cell apoptosis and oxidative stress and alleviated the abnormal mitochondrial morphology and membrane potential of hepatocytes induced by ethanol. Notably, autophagy was significantly enhanced by calcitriol, as evident by the increasing number of autophagosomes and autolysosomes, upregulated LC3B-Ⅱ and ATG5 levels, and promotion of p62 degradation. Furthermore, calcitriol pretreatment increased the colocalization of GFP-LC3-labeled autophagosomes with mitochondria, suggesting that calcitriol effectively promoted ethanol-induced mitophagy in hepatocytes. In addition, the inhibition of autophagy attenuated the protective and preventive effect of calcitriol. Furthermore, the effect of calcitriol on autophagy was regulated by AMPK/mTOR signaling, and signaling transduction was dependent on the Vitamin D receptor (VDR). In conclusion, calcitriol ameliorates ethanol-induced hepatocyte damage by enhancing autophagy. It may offer a convenient preventive and hepatoprotective mean for people on occasional social drink.

Prenatal maternal vitamin D deficiency sex-dependently programs adipose tissue metabolism and energy homeostasis in offspring

In utero environment is crucial to ensure normal development of the fetus and to program metabolic health throughout the life. Beside macronutrients, the role of micronutrients, including vitamin D, begins to be explore. The aim of this study was to decipher the impact of maternal vitamin D deficiency (VDD), in normal and high-fat (HF) diet context, on adipose tissue metabolism and energy homeostasis in offspring, considering sex-specific responses. Body weight, energy expenditure, and spontaneous activity was differential impacted in juvenile male and female offspring born from VDD mice. In adulthood, a HF diet combined with maternal VDD disrupted glucose homeostasis and adiposity in male offspring but not in females. Such phenotypes were associated to different transcriptomic profiles in adipose tissue, which could be related to differential modulation of plasma 17β-estradiol concentrations. Thus, maternal VDD sex-dependently modulated metabolic fate of the offspring, especially when associated with HF diet in adulthood.

The Molecular Mechanisms by Which Vitamin D Prevents Insulin Resistance and Associated Disorders

Numerous studies have shown that vitamin D deficiency is very common in modern societies and is perceived as an important risk factor in the development of insulin resistance and related diseases such as obesity and type 2 diabetes (T2DM). While it is generally accepted that vitamin D is a regulator of bone homeostasis, its ability to counteract insulin resistance is subject to debate. The goal of this communication is to review the molecular mechanism by which vitamin D reduces insulin resistance and related complications. The university library, PUBMED, and Google Scholar were searched to find relevant studies to be summarized in this review article. Insulin resistance is accompanied by chronic hyperglycaemia and inflammation. Recent studies have shown that vitamin D exhibits indirect antioxidative properties and participates in the maintenance of normal resting ROS level. Appealingly, vitamin D reduces inflammation and regulates Ca²⁺ level in many cell types. Therefore, the beneficial actions of vitamin D include diminished insulin resistance which is observed as an improvement of glucose and lipid metabolism in insulin-sensitive tissues.

Decreased miR-150 in obesity-associated type 2 diabetic mice increases intraocular inflammation and exacerbates retinal dysfunction

INTRODUCTION

Diabetic retinopathy (DR) is the leading cause of blindness among the working population in the USA. Current therapies, including anti-vascular endothelial growth factor treatments, cannot completely reverse the visual defects induced by DR. MicroRNA-150 (miR-150) is a regulator that suppresses inflammation and pathological angiogenesis. In patients with diabetes, miR-150 is downregulated. As chronic inflammation is a major contributor to the pathogenesis of DR, whether diabetes-associated decrease of miR-150 is merely associated with the disease progression or decreased miR-150 causes retinal inflammation and pathological angiogenesis is still unknown.

RESEARCH DESIGN AND METHODS

We used high-fat diet (HFD)-induced type 2 diabetes (T2D) in wild type (WT) and miR-150 knockout (miR-150^-/-) mice for this study and compared retinal function and microvasculature morphology.

RESULTS

We found that WT mice fed with an HFD for only 1 month had a significant decrease of miR-150 in the blood and retina, and retinal light sensitivity also decreased. The miR-150^-/- mice on the HFD developed diabetes similar to that of the WT. At 7-8 months old, miR-150^-/- mice under normal diet had increased degeneration of retinal capillaries compared with WT mice, indicating that miR-150 is important in maintaining the structural integrity of retinal microvasculature. Deletion of miR-150 worsened HFD-induced retinal dysfunction as early as 1 month after the diet regimen, and it exacerbated HFD-induced T2DR by further increasing retinal inflammation and microvascular degeneration.

CONCLUSION

These data suggest that decreased miR-150 caused by obesity or diabetic insults is not merely correlated to the disease progression, but it contributes to the retinal dysfunction and inflammation, as well as the development of DR.

Vitamin D inhibits the proliferation of Oral Squamous Cell Carcinoma by suppressing lncRNA LUCAT1 through the MAPK pathway

Background: Oral squamous cell carcinoma (OSCC) is the most common type of oral cancer worldwide. Recent studies have suggested that vitamin D (VitD) is associated with a reduced risk of many chronic illnesses, including cancer. However, the role of vitamin D in OSCC has rarely been reported. Materials and Methods: The effect of vitamin D and control treatment were examined by cell clone formation assay. Using RNA-seq, we globally identified VitD-regulated long noncoding RNAs (lncRNAs). The expression of LUCAT1 in OSCC tissues and cell lines was examined by qRT-PCR. The correlation between LUCAT1 expression level and clinicopathological characteristics was analyzed. The biological roles of LUCAT1 in OSCC cell proliferation was determined by CCK8 and cell colony formation. The role of LUCAT1 in OSCC growth was further confirmed by mouse xenograft tumor model. Combined with the literature, the mechanism of action of LUICAT1 was verified by western blot. Results: In this study, we observed that VitD inhibited tumour cell growth in OSCC. We found that lncRNA LUCAT1 was downregulated by VitD and served as an important mediator of VitD in inhibiting OSCC cell proliferation. Moreover, we observed that the expression of LUCAT1 was significantly upregulated in OSCC tissues compared to non-tumour tissues. We further demonstrated that LUCAT1 promoted the proliferation of oral cancer cells by enhancing the activation of the mitogen protein kinase (MAPK) signalling pathway. Conclusion: In summary, our results show that VitD inhibited the growth of OSCC cells through the LUCAT1-MAPK signalling pathway. Our study suggested that VitD could suppress the progression of oral cancer, and LUCAT1 may be a potential tumour marker for the diagnosis and prognosis of OSCC.

Pathogenesis of psoriasis in the "omic" era. Part III. Metabolic disorders, metabolomics, nutrigenomics in psoriasis

Psoriasis is a systemic disease that is strictly connected with metabolic disorders (insulin resistance, atherogenic dyslipidemia, arterial hypertension, and cardiovascular diseases). It occurs more often in patients with a more severe course of the disease. Obesity is specially an independent risk factor and it is associated with a worse treatment outcome because of the high inflammatory activity of visceral fatty tissue and the production of inflammatory mediators involved in the development of both psoriasis and metabolic disorders. However, in psoriasis the activation of the Th17/IL-17 and the abnormalities in the Th17/Treg balance axis are observed, but this pathomechanism does not fully explain the frequent occurrence of metabolic disorders. Therefore, there is a need to look for better biomarkers in the diagnosis, prognosis and monitoring of concomitant disorders and therapeutic effects in psoriasis. In addition, the education on the use of a proper diet as a prophylaxis for the development of the above disorders is an important element of holistic care for a patient with psoriasis. Diet may affect gene expression due to epigenetic modification which encompasses interactions of environment, nutrition and diseases. Patients with psoriasis should be advised to adopt proper diet and dietician support.

Vitamin D status affects the relationship between lipid profile and high-sensitivity C-reactive protein

Background

The biological pathways through which vitamin D is involved in the regulation of systemic inflammation remain largely unknown.

Objective

The objective of this study was to evaluate the role of vitamin D status on the relationship between lipid profile and high-sensitivity C-reactive protein (hs-CRP) in pregnant women.

Design

Serum 25-hydroxyvitamin D (25(OH)D), hs-CRP, and indicators of lipid profiles (total cholesterol, TC; triglyceride, TG; high-density lipoprotein cholesterol, HDL-C; low-density lipoprotein cholesterol, LDL-C), were measured in 2479 pregnant women during the second trimester. Potential confounding including maternal sociodemographic characteristics, perinatal health status, diet, and lifestyle was prospectively collected. Multiple regression models and cubic models were used to evaluate the associations.

Results

There was a significant non-linear relationship between lipid profile (TC, TG, HDL-C, LDL-C) and hs-CRP (P < 0.05). Increased serum 25(OH)D was significantly associated with decreasing TC, TG, HDL-C, LDL-C, and hs-CRP levels. Compared with medium levels of lipids group, pregnant women with higher levels of TC or TG have higher levels of hs-CRP, and pregnant women with lower levels of TC, HDL-C or LDL-C also have higher levels of hs-CRP in the vitamin D deficient group, and there was a significant correlation between low levels of TG and decreased hs-CRP (adjusted β for TG: -0.063, 95%CI: − 0.120,-0.007) in the non-vitamin D deficient group. Mediators that had appreciable shares of the associations between 25(OH)D and hs-CRP was TG (10.2% of the association; β = − 0.011; total indirect effect: 95% CI: − 0.019, − 0.002). The cubic model suggested that a steep increase in the adjusted regression coefficient of lipid with hs-CRP up to 50 nmol/L of 25(OH)D, and the highest adjusted regression coefficients were observed in pregnant women with 25(OH)D above 50 nmol/L.

Conclusion

Our findings suggest that high levels of vitamin D during pregnancy may improve lipid profile levels and inhibit elevated hs-CRP induced by high lipid metabolism.

The Effect of Vitamin D Supplementation on Insulin Sensitivity: A Systematic Review and Meta-analysis

BACKGROUND

Vitamin D has been suggested to affect peripheral insulin sensitivity. Evidence regarding the effect of vitamin D supplementation on insulin sensitivity is still conflicting.

PURPOSE

This meta-analysis aimed to assess the effect of vitamin D supplementation on insulin sensitivity in humans with or at risk for insulin resistance.

DATA SOURCES AND STUDY SELECTION

PubMed, Web of Science, Embase, CINAHL, and Cochrane Library were systematically searched for randomized controlled trials (RCTs) from 1980 until 31 December 2018 reporting treatment effects of vitamin D supplementation on insulin sensitivity.

DATA EXTRACTION

The main outcome of interest was the change in insulin sensitivity, derived from the gold standard hyperinsulinemic-euglycemic clamp or the Matsuda index derived from the oral glucose tolerance test and insulin sensitivity index from intravenous glucose tolerance test. We extracted data on the standardized mean difference between the vitamin D treatment and placebo groups in change from baseline insulin sensitivity.

DATA SYNTHESIS

Eighteen RCTs were included in this meta-analysis comparing vitamin D supplementation (n = 612) with placebo (n = 608). Vitamin D supplementation had no effect on insulin sensitivity (standardized mean difference -0.01, 95% CI -0.12, 0.10; P = 0.87, I ² = 0%). Visual inspection of funnel plot symmetry did not suggest potential publication bias.

LIMITATIONS

The number of individuals who participated in the included studies was relatively small, possibly due to the invasive character of the measurement (e.g., clamp).

CONCLUSIONS

This meta-analysis provides no evidence that vitamin D supplementation has a beneficial effect on peripheral insulin sensitivity in people with or at risk for insulin resistance.