Altered microRNAs expression in T cells of patients with SLE involved in the lack of vitamin D

Autocrine vitamin D signaling switches off pro-inflammatory programs of TH1 cells

The molecular mechanisms governing orderly shutdown and retraction of CD4+ type 1 helper T (TH1) cell responses remain poorly understood. Here we show that complement triggers contraction of TH1 responses by inducing intrinsic expression of the vitamin D (VitD) receptor and the VitD-activating enzyme CYP27B1, permitting T cells to both activate and respond to VitD. VitD then initiated the transition from pro-inflammatory interferon-γ+ TH1 cells to suppressive interleukin-10+ cells. This process was primed by dynamic changes in the epigenetic landscape of CD4+ T cells, generating super-enhancers and recruiting several transcription factors, notably c-JUN, STAT3 and BACH2, which together with VitD receptor shaped the transcriptional response to VitD. Accordingly, VitD did not induce interleukin-10 expression in cells with dysfunctional BACH2 or STAT3. Bronchoalveolar lavage fluid CD4+ T cells of patients with COVID-19 were TH1-skewed and showed de-repression of genes downregulated by VitD, from either lack of substrate (VitD deficiency) and/or abnormal regulation of this system.

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.

T Cells in Systemic Lupus Erythematosus

T-cell dysregulation has been implicated in the loss of tolerance and overactivation of B cells in systemic lupus erythematosus (SLE). Recent studies have identified T-cell subsets and genetic, epigenetic, and environmental factors that contribute to pathogenic T-cell differentiation, as well as disease pathogenesis and clinical phenotypes in SLE. Many therapeutics targeting T-cell pathways are under development, and although many have not progressed in clinical trials, the recent approval of the calcineurin inhibitor voclosporin is encouraging. Further study of T-cell subsets and biomarkers of T-cell action may pave the way for specific targeting of pathogenic T-cell populations in SLE.

Immunomodulatory Effects of Diet and Nutrients in Systemic Lupus Erythematosus (SLE): A Systematic Review

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by multiple organ involvement, including the skin, joints, kidneys, lungs, central nervous system and the haematopoietic system, with a large number of complications. Despite years of study, the etiology of SLE remains unclear; thus, safe and specifically targeted therapies are lacking. In the last 20 years, researchers have explored the potential of nutritional factors on SLE and have suggested complementary treatment options through diet. This study systematically reviews and evaluates the clinical and preclinical scientific evidence of diet and dietary supplementation that either alleviate or exacerbate the symptoms of SLE. For this review, a systematic literature search was conducted using PubMed, Scopus and Google Scholar databases only for articles written in the English language. Based on the currently published literature, it was observed that a low-calorie and low-protein diet with high contents of fiber, polyunsaturated fatty acids, vitamins, minerals and polyphenols contain sufficient potential macronutrients and micronutrients to regulate the activity of the overall disease by modulating the inflammation and immune functions of SLE.

An autocrine Vitamin D-driven Th1 shutdown program can be exploited for COVID-19

Pro-inflammatory immune responses are necessary for effective pathogen clearance, but cause severe tissue damage if not shut down in a timely manner ^1,2 . Excessive complement and IFN-γ-associated responses are known drivers of immunopathogenesis ³ and are among the most highly induced immune programs in hyper-inflammatory SARS-CoV2 lung infection ⁴ . The molecular mechanisms that govern orderly shutdown and retraction of these responses remain poorly understood. Here, we show that complement triggers contraction of IFN-γ producing CD4 ⁺ T helper (Th) 1 cell responses by inducing expression of the vitamin D (VitD) receptor (VDR) and CYP27B1, the enzyme that activates VitD, permitting T cells to both activate and respond to VitD. VitD then initiates the transition from pro-inflammatory IFN-γ ⁺ Th1 cells to suppressive IL-10 ⁺ Th1 cells. This process is primed by dynamic changes in the epigenetic landscape of CD4 ⁺ T cells, generating superenhancers and recruiting c-JUN and BACH2, a key immunoregulatory transcription factor ^5-7 . Accordingly, cells in psoriatic skin treated with VitD increased BACH2 expression, and BACH2 haplo-insufficient CD4 ⁺ T cells were defective in IL-10 production. As proof-of-concept, we show that CD4 ⁺ T cells in the bronchoalveolar lavage fluid (BALF) of patients with COVID-19 are Th1-skewed and that VDR is among the top regulators of genes induced by SARS-CoV2. Importantly, genes normally down-regulated by VitD were de-repressed in CD4 ⁺ BALF T cells of COVID-19, indicating that the VitD-driven shutdown program is impaired in this setting. The active metabolite of VitD, alfacalcidol, and cortico-steroids were among the top predicted pharmaceuticals that could normalize SARS-CoV2 induced genes. These data indicate that adjunct therapy with VitD in the context of other immunomodulatory drugs may be a beneficial strategy to dampen hyperinflammation in severe COVID-19.

Exploring the Role of Non-Coding RNAs in the Pathophysiology of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic immune-related disorder designated by a lack of tolerance to self-antigens and the over-secretion of autoantibodies against several cellular compartments. Although the exact pathophysiology of SLE has not been clarified yet, this disorder has a strong genetic component based on the results of familial aggregation and twin studies. Variation in the expression of non-coding RNAs has been shown to influence both susceptibility to SLE and the clinical course of this disorder. Several long non-coding RNAs (lncRNAs) such as GAS5, MALAT1 and NEAT1 are dysregulated in SLE patients. Moreover, genetic variants within lncRNAs such as SLEAR and linc00513 have been associated with risk of this disorder. The dysregulation of a number of lncRNAs in the peripheral blood of SLE patients has potentiated them as biomarkers for diagnosis, disease activity and therapeutic response. MicroRNAs (miRNAs) have also been shown to affect apoptosis and the function of immune cells. Taken together, there is a compelling rationale for the better understanding of the involvement of these two classes of non-coding RNAs in the pathogenesis of SLE. Clarification of the function of these transcripts has the potential to elucidate the molecular pathophysiology of SLE and provide new opportunities for the development of targeted therapies for this disorder.

Nutritive vitamins as epidrugs

Epigenetic modifications play an important role in disease pathogenesis and therefore are a focus of intense investigation. Epigenetic changes include DNA, RNA, and histone modifications along with expression of non-coding RNAs. Various factors such as environment, diet, and lifestyle can influence the epigenome. Dietary nutrients like vitamins can regulate both physiological and pathological processes through their direct impact on epigenome. Vitamin A acts as a major regulator of above-mentioned epigenetic mechanisms. B group vitamins including biotin, niacin, and pantothenic acid also participate in modulation of various epigenome. Further, vitamin C has shown to modulate both DNA methylation and histone modifications while few reports have also supported its role in miRNA-mediated pathways. Similarly, vitamin D also influences various epigenetic modifications of both DNA and histone by controlling the regulatory mechanisms. Despite the information that vitamins can modulate the epigenome, the detailed mechanisms of vitamin-mediated epigenetic regulations have not been explored fully and hence further detailed studies are required to decipher their role at epigenome level in both normal and disease pathogenesis. The current review summarizes the available literature on the role of vitamins as epigenetic modifier and highlights the key evidences for developing vitamins as potential epidrugs.

[Vitamin D down-regulates microRNA-21 expression to promote human placental trophoblast cell migration and invasion in vitro]

OBJECTIVE

To investigate the effect of vitamin D on microRNA-21(miR-21) expression and migration and invasion of human placental trophoblast cells.

METHODS

The changes in the expression of miR-21 were detected using RT-qPCR in HTR-8/SVneo cells following stimulation by vitamin D at different doses for 24, 48 and 72 h.HTR-8/SVneo cells transfected with miR-21 mimic or inhibitor with or without vitamin D treatment were examined for changes in cell migration and invasion abilities using Transwell assay, and Western blotting was used to detect protein expressions of E-cadherin, fibronectin, and MMP9.

RESULTS

Vitamin D obviously inhibited the expression of micoRNA-21 in HTR-8/SVneo cells in a concentration-and time-dependent manner.Transfection with the miR-21 mimic significantly inhibited the migration and invasion of HTR-8/SVneo cells, and this inhibitory effect was abolished by treatment with vitamin D; transfection with miR-21 inhibitor obviously promoted the migration and invasion of HTR-8/SVneo cells, and these effects were not significantly affected by vitamin D treatment.

CONCLUSIONS

Vitamin D may promote trophoblast cell migration and invasion to accelerate the development of preeclampsia by down-regulating the expression of miR-21.

Mechanisms of vascular comorbidity in autoimmune diseases

Purpose of review

Persuasive statistics support the clinical observation that because of cardiovascular comorbidities patients with inflammatory joint disease die significantly earlier despite anti-inflammatory therapy.

Recent findings

The reason for this earlier death is multifactorial and involves a combination of a complex genetic background, environmental influences, classical cardiovascular risk factors and the impact of anti-inflammatory therapy. We will describe the importance of several new mechanisms, especially the diverse intercellular communication routes including extracellular vesicles and microRNAs that support the development of cardiovascular comorbidities.

Summary

The aim of this review is to give an updated overview about the known risk factors in the development of cardiovascular comorbidities with the latest insights about their mechanism of action. Furthermore, the impact of newly identified risk factors and significance will be discussed.

Microarray expression profile of circular RNAs and mRNAs in children with systemic lupus erythematosus

BACKGROUND

Recently, it was reported that circular RNAs (circRNAs) play the crucial role in many physiological and biological processes and can be used as biomarkers. However, the information about circRNAs in children with systemic lupus erythematosus (SLE) is limited. The aim of this study is to determine the expression of circRNAs in children with SLE and investigate the significance of circRNA for diagnosing SLE.

METHODS

Microarray profile of circRNAs and mRNAs was performed for identifying the changes in expression of circRNAs and mRNAs between children with SLE and healthy children. Quantitative polymerase chain reaction (qPCR) was used to confirm the results. Spearman correlation test was performed to assess the correlation between circRNAs and clinical variables. The receiver operating characteristic (ROC) curve was calculated for evaluating the diagnostic value.

RESULTS

A comparison between the children with SLE and healthy children revealed that 348 circRNAs and 1162 mRNAs were expressed differentially. The authors constructed a complex circRNA target network consisting of 307 matched circRNA-mRNA pairs for 124 differentially expressed circRNAs (74 circRNAs were upregulated, and 50 circRNAs were downregulated) and 142 differentially expressed mRNAs (83 mRNAs were upregulated, and 59 mRNAs were downregulated) by using gene co-expression network analysis. The competing for endogenous RNA (ceRNA) network includes 42 differentially expressed circRNAs, 41 differentially expressed mRNAs, and 71 predicted miRNAs. Among these SLE patients, we detected that the hsa_circ_0021372 and hsa_circ_0075699 levels are associated with C3 and C4 levels in children with SLE. The hsa_circ_0057762 level is positively associated with the SLEDAI-2K score. The ROC curves of circRNAs showed that the levels of hsa_circ_0057762 (AUC 0.804, 95% CI 0.607-1.0, P = 0.02) and hsa_circ_0003090 (AUC 0.848, 95% CI 0.688-1.0, P = 0.008) could differentiate the patients with SLE from the healthy controls.

CONCLUSIONS

We firstly characterized the expression profiles of circRNA and mRNA in children with SLE and propose herein their possible roles in the pathogenesis of SLE. These results provide novel insight into the mechanisms of SLE pathogenesis, and circRNAs may serve as useful biomarkers for SLE.