Vitamin D boosts immune response of macrophages through a regulatory network of microRNAs and mRNAs

Focusing on non-responders to infliximab with ulcerative colitis, what can we do first and next?

BACKGROUND

Ulcerative colitis (UC) is a chronic immune-mediated inflammation of the colorectum, for which infliximab (IFX) is currently the mainstay of treatment. However, one-third of patients with UC still fail to benefit from the IFX therapy, and early exposure to IFX impairs the efficacy of other subsequent biologics. Therefore, personalized therapeutic system is urgently needed to assist in clinical decision-making and precision treatment.

METHODS

Four microarray datasets of colonic biopsies from UC patients treated with IFX were obtained from the GEO database to form the Training Cohort and Validation Cohort. Differentially expressed genes (DEGs) in Training Cohort were identified and enriched for GO, KEGG and immune cell infiltration analysis. A prediction model for IFX efficacy was developed based on the LASSO and Logistic regression. The predictive accuracy of the model was verified by the Validation Cohort, and the model-genes/proteins were validated by immunohistochemistry. Gene-drug, gene-ncRNA interaction analysis were performed to identify drugs or non-coding RNAs (ncRNAs) that potentially interacted with the model-genes. Homology Modeling and Molecular Docking were conducted to filter the optimal candidate as the subsequent adjuvant or alternative for IFX in predicted non-responders. At last, the down-regulation of the key model-gene/protein CYP24A1 by the drug candidate Deferasirox was verified by Western Blot and qRT-PCR Assay based on cellular experiments.

RESULTS

A total of 113 DEGs were identified in the Training Cohort, mainly enriched in inflammatory cell chemotaxis, migration, and response to molecules derived from intestinal microbiota. Activated pro-inflammatory innate immune cells, including neutrophils, M1 macrophages, activated dendritic cells and mast cells, were significantly enriched in colons of non-responders. The prediction model based on three model-genes (IFI44L, CYP24A1, and RGS1) exhibited strong predictive efficacy, with AUC values of 0.901 and 0.80 in the Training and Validation Cohorts, respectively. Higher expression of the three model-genes/proteins in colons of non-responders to IFX was confirmed by clinical colonic mucosal biopsies. 4 Drugs (Calcitriol, Lunacalcipol, Deferasirox, Telaprevir), 15 miRNAs and 66 corresponding lnRNAs interacting with model-genes were identified. The protein 3D structure of the key model-gene/protein (human-derived CYP24A1) was developed. Through the Molecular Docking and cellular experimental validation, Deferasirox, which significantly down-regulated both the RNA and protein expression of CYP24A1, was identified as the optimal adjuvant or alternative for IFX in predicted non-responders with UC.

CONCLUSION

This study developed a novel prediction model for pre-assessing the efficacy of IFX in patients with UC, as the first step towards personalized therapy. Meanwhile, drugs and non-coding RNAs were provided as potential candidates to develop the next-step precise treatment for the predicted non-responders. In particular, Defeasirox appears to hold promise as an adjuvant or alternative to IFX for the optimization of UC therapy.

Genomic and non-genomic action of vitamin D on ion channels - Targeting mitochondria

Recent studies revealed that mitochondria are not only a place of vitamin D3 metabolism but also direct or indirect targets of its activities. This review summarizes current knowledge on the regulation of ion channels from plasma and mitochondrial membranes by the active form of vitamin D3 (1,25(OH)2D3). 1,25(OH)2D3, is a naturally occurring hormone with pleiotropic activities; implicated in the modulation of cell differentiation, and proliferation and in the prevention of various diseases, including cancer. Many experimental data indicate that 1,25(OH)2D3 deficiency induces ionic remodeling and 1,25(OH)2D3 regulates the activity of multiple ion channels. There are two main theories on how 1,25(OH)2D3 can modify the function of ion channels. First, describes the involvement of genomic pathways of response to 1,25(OH)2D3 in the regulation of the expression of the genes encoding channels, their auxiliary subunits, or additional regulators. Interestingly, intracellular ion channels, like mitochondrial, are encoded by the same genes as plasma membrane channels. Therefore, the comprehensive genomic regulation of the channels from these two different cellular compartments we analyzed using a bioinformatic approach. The second theory explores non-genomic pathways of vitamin D3 activities. It was shown, that 1,25(OH)2D3 indirectly regulates enzymes that impact ion channels, change membrane physical properties, or directly bind to channel proteins. In this article, the involvement of genomic and non-genomic pathways regulated by 1,25(OH)2D3 in the modulation of the levels and activity of plasma membrane and mitochondrial ion channels was investigated by an extensive review of the literature and analysis of the transcriptomic data using bioinformatics.

Alterations in Circadian Rhythms, Sleep, and Physical Activity in COVID-19: Mechanisms, Interventions, and Lessons for the Future

Although the world is acquitting from the throes of COVID-19 and returning to the regularity of life, its effects on physical and mental health are prominently evident in the post-pandemic era. The pandemic subjected us to inadequate sleep and physical activities, stress, irregular eating patterns, and work hours beyond the regular rest-activity cycle. Thus, perturbing the synchrony of the regular circadian clock functions led to chronic psychiatric and neurological disorders and poor immunological response in several COVID-19 survivors. Understanding the links between the host immune system and viral replication machinery from a clock-infection biology perspective promises novel avenues of intervention. Behavioral improvements in our daily lifestyle can reduce the severity and expedite the convalescent stage of COVID-19 by maintaining consistent eating, sleep, and physical activity schedules. Including dietary supplements and nutraceuticals with prophylactic value aids in combating COVID-19, as their deficiency can lead to a higher risk of infection, vulnerability, and severity of COVID-19. Thus, besides developing therapeutic measures, perpetual healthy practices could also contribute to combating the upcoming pandemics. This review highlights the impact of the COVID-19 pandemic on biological rhythms, sleep-wake cycles, physical activities, and eating patterns and how those disruptions possibly contribute to the response, severity, and outcome of SARS-CoV-2 infection.

The Effects of Vitamin D Supplementation on C-Reactive Protein and Systolic and Diastolic Blood Pressure in Postmenopausal Women: A Meta-Analysis and Systematic Review of Randomized Controlled Trials

BACKGROUND

An inverse relationship between vitamin D supplementation and C-reactive protein (CRP) and hypertension has been reported, mostly through observational data. This inverse relationship, however, has not been confirmed in randomized controlled trials (RCTs). A meta-analysis of RCTs is needed to provide more robust evidence.

OBJECTIVE

This systematic review of RCTs was conducted to assess the effect of vitamin D supplementation on CRP, systolic blood pressure (SBP), and diastolic blood pressure (DBP) in postmenopausal women.

METHODS

Four databases (PubMed, Web of Science, Embase, and Scopus) were systemically searched to identify relevant RCTs published in international scientific journals up to January 2023. Changes from baseline and SDs of CRP, SBP, and DBP were compared between postmenopausal women who received vitamin D supplementation and those who did not (controls). These parameters were applied to compute the overall effect sizes using the random-effects model. Data were summarized as mean difference (MD) with 95% CI. Heterogeneity among arms was scrutinized using the Cochrane's Q test and I2 statistic. Publication bias was judged by means of funnel plots and Egger's test.

RESULTS

Seven studies with 6 arms on CRP, 6 arms on SBP, and 6 arms on DBP were included in the meta-analysis. Combined effect sizes suggested a significant effect of vitamin D supplementation on CRP (MD = -0.65 mg/L; 95% CI -0.93 to -0.37 mg/L; P < .001). In addition, CRP concentrations were significantly reduced after vitamin D supplementation in studies with a duration of more than 3 months (MD = -0.91 mg/L; 95% CI -1.37 to -0.45 mg/L; P < .001) and studies involving doses of ≤1,000 IU/d (MD = -2.10 mg/L; 95% CI -2.51 to -1.68 mg/L; P < .001). Vitamin D supplementation did not reduce SBP significantly (MD = -1.06 mm Hg; 95% CI -2.43 to 0.30 mm Hg; P = .127) and DBP (MD = 0.003 mm Hg; 95% CI -0.86 to 0.86 mm Hg; P = .994) levels compared with control groups.

CONCLUSIONS

This meta-analysis concluded that vitamin D supplementation is associated with reduced CRP concentrations among postmenopausal women.

Immunomodulatory effect of vitamin D supplementation on Behçet's disease patients: effect on nitric oxide and Th17/Treg cytokines production

INTRODUCTION

In the last decade, an immuno-modulatory effect of vitamin D supplementation have emerged as a potential therapeutic approach for some inflammatory and autoimmune diseases. As previously reported, vitamin D deficiency was strongly linked to several diseases as Behçet's disease (BD). BD is a chronic systemic inflammatory disorder with autoimmunity, genetic and environmental factors involvement. The aim of our current study is to set up a new therapeutic strategy in BD, combining conventional therapy and vitamin D supplementation.

MATERIALS AND METHODS

Blood samples were collected from active and inactive BD patients and healthy controls (HC) to evaluate 25(OH) vitamin D levels using an electrochemiluminescence method. All deficient and insufficient vitamin D BD patients' were supplemented with vitamin D3 (CHOLECALCIFEROL, 200 000 UI/1 ml). In this context, NO, IL-17A and IL-10 levels were evaluated in patients and HC in vivo and ex vivo using Griess and ELISA methods respectively.

RESULTS

Before supplementation, we noted with interest that BD patients had vitamin D deficiency, associated with elevated in vivo and ex vivo NO and IL-17A levels compared to HC. Conversely, low IL-10 levels were observed in the same BD patients in comparison to HC. Interestingly, restored vitamin D status in supplemented BD patients was related to the decreased NO levels. In the same way, the IL-10/IL-17A ratio was improved.

CONCLUSIONS

Collectively, our data suggest that vitamin D supplementation in combination with conventional treatments has a beneficial effect and could constitute a good therapeutic candidate for alleviating inflammatory responses during Behçet disease.

The Associations of Cardiometabolic and Dietary Variables with Clinical Periodontitis in Adults with and without Type 2 Diabetes: A Cross-Sectional Study

Periodontitis is a commonly occurring inflammatory oral disease affecting a large proportion of global and US adults and is characterized by the destruction of the tooth-supporting apparatus. Its etiology is multifactorial, and type 2 diabetes and diet play critical roles in its remission and progression. However, few studies have addressed nutritional and serum vitamin D status in adults with periodontitis in the presence of diabetes. A cross-sectional study (n = 78), and a sub-set of age- and BMI-matched case-control studies (n = 50), were conducted to examine differences in dietary and cardiometabolic variables, and serum vitamin D in adults with periodontitis with or without diabetes. Participants provided fasting blood samples and 24-h diet recalls on at least two different days. Data on health history, body weight, height, nutritional habits, and clinical features of periodontitis were also collected. The Mann-Whitney U Test (with exact p-value estimation by Monte Carlo simulation) was used to examine differences by diabetes status in continuous and ordinal variables. Results revealed significantly lower serum vitamin D, and dietary intake of fruits, vegetables, dairy, vitamins A and C in adults with periodontitis with vs. without diabetes in the sub-study (all p < 0.05). In the overall sample, adults with diabetes presented with higher caries risk measures and lower numbers of teeth than those without diabetes; plaque and bleeding scores did not differ by diabetes status. Finally, a significant associations of food habits was observed, especially consuming protein-rich foods twice a day with a lower bleeding score, and daily consumption of fried or fast foods with a fewer number of teeth present (all p < 0.05). The present findings show significant dietary and serum vitamin D inadequacies among adults with periodontitis, and diabetes further aggravates the observed malnourishment and oral health.

COVID-19 Vaccination in Pregnancy: Pilot Study for Maternal and Neonatal MicroRNA Profiles

This pilot study explores alterations in miRNA profiles among pregnant women and their neonates upon receiving different doses of COVID-19 vaccines. Blood samples, including maternal blood (MB) and neonatal cord blood (CB), collected from five pregnant women were scrutinized using the miRNA PanelChip Analysis System, identifying nine distinct miRNAs, including miR-451a and miR-1972, which exhibited significant downregulation with two vaccine doses in both MB and CB. When compared with women vaccinated with four doses, miR-486-5p, miR-451a, and miR-1972 in the two-dose group also showed notable downregulation. Evaluating recipients of three and four doses, miR-423-5p and miR-1972 expression were significantly reduced in both MB and CB. Further comparative analysis highlighted a decline in miR-223-3p expression with increasing vaccine doses, while miR15a-5p, miR-16-5p, and miR-423-5p showed an upward trend. Notably, miR-451a, miR-1972, and miR-423-5p levels varied across doses and were associated with pathways such as "PI3K-Akt", "neurotrophin signaling", and "cortisol synthesis", suggesting the profound influence of vaccination on diverse molecular mechanisms. Our research has uncovered that escalating vaccine dosages impact miRNA profiles, which may be associated with the immunological response mechanisms in both the mother and fetus, thus indicating a substantial impact of vaccination on various molecular processes.

Vitamin D Influences the Activity of Mast Cells in Allergic Manifestations and Potentiates Their Effector Functions against Pathogens

Mast cells (MCs) are abundant at sites exposed to the external environment and pathogens. Local activation of these cells, either directly via pathogen recognition or indirectly via interaction with other activated immune cells and results in the release of pre-stored mediators in MC granules. The release of these pre-stored mediators helps to enhance pathogen clearance. While MCs are well known for their protective role against parasites, there is also significant evidence in the literature demonstrating their ability to respond to viral, bacterial, and fungal infections. Vitamin D is a fat-soluble vitamin and hormone that plays a vital role in regulating calcium and phosphorus metabolism to maintain skeletal homeostasis. Emerging evidence suggests that vitamin D also has immunomodulatory properties on both the innate and adaptive immune systems, making it a critical regulator of immune homeostasis. Vitamin D binds to its receptor, called the vitamin D receptor (VDR), which is present in almost all immune system cells. The literature suggests that a vitamin D deficiency can activate MCs, and vitamin D is necessary for MC stabilization. This manuscript explores the potential of vitamin D to regulate MC activity and combat pathogens, with a focus on its ability to fight viruses.

Vitamin D is inversely associated with Monocyte to HDL-C ratio among medical staff in Chengdu, China

PURPOSE

The primary objective of this study was to explore the association of vitamin D with the monocyte to HDL-C ratio (MHR) among medical staff in Chengdu, China.

MATERIALS AND METHODS

This cross-sectional study involved 538 medical staff, including 393 females and 145 males, and included data on gender, age, body mass index, and laboratory parameters (including complete blood count, vitamin D levels, lipid, etc.). According to serum 25 (OH)D < 20 ng/ml as vitamin D deficiency, subjects were divided into two groups based on serum 25 (OH)D levels: a vitamin D deficiency group with serum 25 (OH)D < 20 ng/ml and a vitamin D sufficiency group with serum 25 (OH)D ≥ 20 ng/ml. When considering vitamin D as a categorical variable, a multivariable logistic regression analysis was conducted to assess the risk factors associated with vitamin D deficiency. On the other hand, when examining the factors influencing vitamin D levels as a continuous variable, a multiple linear regression model was utilized.

RESULTS

The prevalence of vitamin D deficiency was 86.25% among all the participants. Males exhibited a higher risk of vitamin D deficiency compared to females (β=0.383, P = 0.026). Vitamin D deficiency risk decreased with age (β = 0.910, P < 0.001). Additionally, elevated values of MHR were associated with an increased risk of vitamin D deficiency (β = 1.530, P = 0.019). When treating vitamin D as a continuous variable, the results of multiple linear regression revealed that age (β = 0.342, P < 0.001), and TG (β=-1.327, P = 0.010) were independent influencing factors for vitamin D levels, indicating that vitamin D levels increase with age. A reverse association between MHR and vitamin D levels demonstrated a marginal trend toward significance (β=-0.581, P = 0.052).

CONCLUSIONS

Vitamin D is inversely associated with MHR among young medical staff in Chengdu, China.

Potential tactics with vitamin D and certain phytochemicals for enhancing the effectiveness of immune-checkpoint blockade therapies

Immunotherapy strategies targeting immune checkpoint molecules such as programmed cell death-1 (PD-1) and cytotoxic T-lymphocyte-associated protein-4 (CTLA-4) are revolutionizing oncology. However, its effectiveness is limited in part due to the loss of effector cytotoxic T lymphocytes. Interestingly, supplementation of vitamin D could abolish the repressive effect of programmed cell death-ligand 1 (PD-L1) on CD8⁺ T cells, which might prevent the lymphocytopenia. In addition, vitamin D signaling could contribute to the differentiation of T-regulatory (Treg) cells associated with the expression of Treg markers such as forkhead box P3 (FOXP3) and CTLA-4. Furthermore, vitamin D may be associated with the stimulation of innate immunity. Peroxisome proliferator-activated receptor (PPAR) and estrogen receptor (ESR) signaling, and even the signaling from phosphoinositide-3 kinase (PI3K)/AKT pathway could have inhibitory roles in carcinogenesis possibly via the modulation of immune checkpoint molecules. In some cases, certain small molecules including vitamin D could be a novel therapeutic modality with a promising potential for the better performance of immune checkpoint blockade cancer therapies.

Vitamin D modulates expression of antimicrobial peptides and proinflammatory cytokines to restrict Zika virus infection in macrophages

Although the impact of Zika virus (ZIKV) infection on human health has been well documented, we still have no vaccine or effective treatment. This fact highlights the importance of searching for alternative therapy for treating ZIKV. To search for ZIKV antivirals, we examined the effect of vitamin D in monocyte-derived macrophages (MDMs) differentiated in the presence of vitamin D (D3-MDM) and explored the molecular mechanisms by analyzing transcriptional profiles. Our data show the restriction of ZIKV infection in D3-MDMs as compared to MDMs. Transcriptional profiles show that vitamin D alters about 19% of Zika response genes (8.2% diminished and 10.8% potentiated). Among the genes with diminished expression levels, we found proinflammatory cytokines and chemokines such as IL6, TNF, IL1A, IL1B, and IL12B, CCL1, CCL4, CCL7, CXCL3, CXCL6, and CXCL8. On the other hand, genes with potentiated expression were related to degranulation such as Lysozyme, cathelicidin (CAMP), and Serglycin. Since the CAMP gene encodes the antimicrobial peptide LL-37, we treated MDMs with LL-37 and infected them with ZIKV. The results showed a decrease in the proportion of infected cells. Our data provide new insights into the role of vitamin D in restricting ZIKV infection in macrophages that are mediated by induction of cathelicidin/LL-37 expression and downregulation of proinflammatory genes. Results highlight the biological relevance of vitamin D-inducible peptides as an antiviral treatment for Zika fever.

Obesity and dysregulated innate immune responses: impact of micronutrient deficiencies

Obesity is associated with the development of various complications, including diabetes, atherosclerosis, and an increased risk for infections, driven by dysfunctional innate immune responses. Recent insights have revealed that the availability of nutrients is a key determinant of innate immune cell function. Although the presence of obesity is associated with overnutrition of macronutrients, several micronutrient deficiencies, including Vitamin D and zinc, are often present. Micronutrients have been attributed important immunomodulatory roles. In this review, we summarize current knowledge of the immunomodulatory effects of Vitamin D and zinc. We also suggest future lines of research to further improve our understanding of these micronutrients; this may serve as a stepping-stone to explore micronutrient supplementation to improve innate immune cell function during obesity.

Latest Knowledge on the Role of Vitamin D in Hypertension

Hypertension is the third leading cause of the global disease burden, and while populations live longer, adopt more sedentary lifestyles, and become less economically concerned, the prevalence of hypertension is expected to increase. Pathologically elevated blood pressure (BP) is the strongest risk factor for cardiovascular disease (CVD) and related disability, thus making it imperative to treat this disease. Effective standard pharmacological treatments, i.e., diuretics, angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blocker (ARBs), beta-adrenergic receptor blockers (BARBs), and calcium channel blockers (CCBs), are available. Vitamin D (vitD) is known best for its role in bone and mineral homeostasis. Studies with vitamin D receptor (VDR) knockout mice show an increased renin-angiotensin-aldosterone system (RAAS) activity and increased hypertension, suggesting a key role for vitD as a potential antihypertensive agent. Similar studies in humans displayed ambiguous and mixed results. No direct antihypertensive effect was shown, nor a significant impact on the human RAAS. Interestingly, human studies supplementing vitD with other antihypertensive agents reported more promising results. VitD is considered a safe supplement, proposing its great potential as antihypertensive supplement. The aim of this review is to examine the current knowledge about vitD and its role in the treatment of hypertension.