Vitamin D and toll like receptors

Association between Vitamin D Deficiency and Prediabetes Phenotypes: A Population-Based Study in Henan, China

The evidence remains inconsistent regarding whether vitamin D deficiency (VDD) increases the risk of prediabetes. This study aimed to examine whether there is sex-specific association between VDD and impaired fasting glucose (IFG) or impaired glucose tolerance (IGT) in Henan. The data were sourced from the survey of chronic diseases and nutrition in Henan. Multinomial logistic regression models based on complex sampling design and weight were developed to estimate the odds ratio (OR) and confidence interval (95%CI) for measuring the association between VDD and IFG/IGT. The prevalence rate of IGT in men was 20.1% in the VDD group, significantly higher than that in the non-VDD group (10.5%), but no significant difference was observed in women between the VDD and non-VDD groups; there were no significant differences in IFG prevalence between the VDD and non-VDD groups in either men or women. It was found that the association between VDD and IGT was statistically significant in men. The adjusted OR (95%CI) of VDD was 1.99 (1.24-3.19) for IGT in men and 14.84 (4.14-53.20) for IGT in men having a family history of DM. Thus, men with VDD were more likely to live with IGT than those without VDD, especially for men having a family history of diabetes.

Vaccinomics and adversomics: key elements for a personalized vaccinology

Vaccines are one of the most important and effective tools in the prevention of infectious diseases and research about all the aspects of vaccinology are essential to increase the number of available vaccines more and more safe and effective. Despite the unquestionable value of vaccinations, vaccine hesitancy has spread worldwide compromising the success of vaccinations. Currently, the main purpose of vaccination campaigns is the immunization of whole populations with the same vaccine formulations and schedules for all individuals. A personalized vaccinology approach could improve modern vaccinology counteracting vaccine hesitancy and giving great benefits for human health. This ambitious purpose would be possible by facing and deepening the areas of vaccinomics and adversomics, two innovative areas of study investigating the role of a series of variables able to influence the immune response to vaccinations and the development of serious side effects, respectively. We reviewed the recent scientific knowledge about these innovative sciences focusing on genetic and non-genetic basis involved in the individual response to vaccines in terms of both immune response and side effects.

Do chemokine/chemokine receptor axes play paramount parts in trafficking and oriented locomotion of monocytes/macrophages toward the lungs of COVID-19 infected patients? A systematic review

The COVID-19 (coronavirus disease 2019) is a well-defined viral infection, resulting from SARS-CoV-2 (severe acute respiratory syndrome- coronavirus-2). The innate immune system serves as the first line of defense to limit viral spreading and subsequently stimulate adaptive immune responses by the prominent aids of its cellular and molecular arms. Monocytes are defined as the most prominent innate immune cells (IICs) that are reactive against invading pathogens. These cells support host protection against the virus that is mediated by several non-specific mechanisms such as phagocytosis, producing antiviral enzymes, and recruitment of immune cells toward and into the infected tissues. They have the ability to egress from blood and migrate to the SARS-CoV-2 infected regions by the aid of some defense-related functions like chemotaxis, which is mediated by chemical compounds, e.g., chemokines. Chemokines, in addition to their related ligands are categorized within the most important and deserved agents involved in oriented trafficking of monocytes/macrophages towards and within the lung parenchyma in both steady state and pathological circumstances, including COVID-19-raised infection. However, the overexpression of chemokines could have deleterious effects on various organs through the induction of cytokine storm and may be the most important leading mechanisms in the pathogenesis of COVID-19. Authors have aimed the current review article to describe present knowledge about the interplay between monocytes/macrophages and SARS-CoV-2 with a focus on the ability of IICs to migrate and home into the lung of COVID-19 patients through various chemokine-chemokine receptor axes to promote our understanding regarding this disease.

Low plasma vitamin D is associated with increased 28-day mortality and worse clinical outcomes in critically ill patients

BACKGROUND & OBJECTIVE

Patients in the intensive care unit have a high prevalence of vitamin D deficiency (VDD). In the present study, clinical outcomes in the ICU were analyzed with vitamin D status.

MATERIALS AND METHODS

In this prospective, multicenter study, sampling was conducted on seven ICUs in three hospitals. Within the first 24 h of ICU admission, patient's serum vitamin D levels were measured, and their disease severity was monitored using the scores of acute physiologic assessment and chronic health evaluation II (APACHE II), sequential organ failure assessment (SOFA), and the modified Nutrition Risk in Critically ill (mNUTRIC) score.

RESULTS

A total of 236 patients were enrolled in this study, of which 163 (69.1%) had lower vitamin D levels than 20 ng/ml upon ICU admission. The patients with VDD had higher APACHE II scores)P = 0.02), SOFA scores (P < 0.001), and mNUTRIC scores (P = 0.01). Patients with sufficient levels of vitamin D (> 30 ng/ml) had a shorter stay at ICU (P < 0.001). VDD was independently associated with 28-day mortality (OR: 4.83; 95% CI: 1.63-14.27; P = 0.004).

CONCLUSION

The data showed that VDD was common among the critically ill and was related to a more severe course of illness and a higher mortality rate.

Mini-Review on Vitamin D in Pediatric Population and its Role in Respiratory and Atopic Disorders

In recent years, our comprehension of the function of vitamin D has significantly evolved. The ubiquitous presence of the vitamin D receptor (Vitamin D Receptor- VDR) in the body has led to its redefinition from a steroidal hormone primarily involved in skeletal functions to a hormone with pleiotropic effects, exerting its influence on the circulatory, nervous, and immune systems. This has prompted investigations into its potential use in preventing and treating chronic metabolic disorders, cardiovascular diseases, infections, and allergic and autoimmune diseases. This comprehensive review explores the various aspects of vitamin D, including its sources, synthesis, functions, and its impact on different physiological systems. It delves into the epidemiology of vitamin D deficiency, highlighting its occurrence among various age demographics and geographic regions. The impact of vitamin D on the immune system is also explored, elucidating its immunomodulatory and anti-inflammatory properties, particularly in the context of respiratory infections. The review discusses emerging evidence concerning the potential advantages of vitamin D in respiratory diseases, pediatric asthma and atopic dermatitis. It also addresses vitamin D supplementation recommendations for various pediatric populations, including term and preterm infants. The growing concern regarding the global health impacts of insufficient vitamin D levels necessitates further research to bridge gaps in knowledge, particularly in enhancing screening, prevention, and approaches to address vitamin D deficiency from birth onwards. In summary, this comprehensive overview underscores the vital role of vitamin D, highlighting the significance of understanding its multifaceted functions and the need for tailored supplementation strategies, especially in vulnerable populations.

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.

Infections and Autoimmunity-The Immune System and Vitamin D: A Systematic Review

Both 25-autoimmunity and(25(OH)D: calcifediol) and its active form, 1,25-dihydroxyvitamin D (1,25(OH)2D: calcitriol), play critical roles in protecting humans from invasive pathogens, reducing risks of autoimmunity, and maintaining health. Conversely, low 25(OH)D status increases susceptibility to infections and developing autoimmunity. This systematic review examines vitamin D's mechanisms and effects on enhancing innate and acquired immunity against microbes and preventing autoimmunity. The study evaluated the quality of evidence regarding biology, physiology, and aspects of human health on vitamin D related to infections and autoimmunity in peer-reviewed journal articles published in English. The search and analyses followed PRISMA guidelines. Data strongly suggested that maintaining serum 25(OH)D concentrations of more than 50 ng/mL is associated with significant risk reduction from viral and bacterial infections, sepsis, and autoimmunity. Most adequately powered, well-designed, randomized controlled trials with sufficient duration supported substantial benefits of vitamin D. Virtually all studies that failed to conclude benefits or were ambiguous had major study design errors. Treatment of vitamin D deficiency costs less than 0.01% of the cost of investigation of worsening comorbidities associated with hypovitaminosis D. Despite cost-benefits, the prevalence of vitamin D deficiency remains high worldwide. This was clear among those who died from COVID-19 in 2020/21-most had severe vitamin D deficiency. Yet, the lack of direction from health agencies and insurance companies on using vitamin D as an adjunct therapy is astonishing. Data confirmed that keeping an individual's serum 25(OH)D concentrations above 50 ng/mL (125 nmol/L) (and above 40 ng/mL in the population) reduces risks from community outbreaks, sepsis, and autoimmune disorders. Maintaining such concentrations in 97.5% of people is achievable through daily safe sun exposure (except in countries far from the equator during winter) or taking between 5000 and 8000 IU vitamin D supplements daily (average dose, for non-obese adults, ~70 to 90 IU/kg body weight). Those with gastrointestinal malabsorption, obesity, or on medications that increase the catabolism of vitamin D and a few other specific disorders require much higher intake. This systematic review evaluates non-classical actions of vitamin D, with particular emphasis on infection and autoimmunity related to the immune system.

Towards a Future of Personalized Vaccinology: Study on Individual Variables Influencing the Antibody Response to the COVID-19 Vaccine

The COVID-19 pandemic has hugely impacted many different aspects of human health, and vaccination is one of the most effective weapons to manage it. However, many different factors, such as age, gender, comorbidities and lifestyles, play a role in the response to infections and vaccines. We carried out this study to evaluate the potential role played by some individual factors in the production of anti-COVID-19 antibodies in the light of personalized and future vaccinology. We conducted an observational study consisting of a retrospective phase, exploiting previous data about anti-COVID-19 antibody responses, with a prospective phase to investigate individual variables through the use of a questionnaire. The antibody response after the COVID-19 vaccination was inversely related to old age, increased BMI and the number of smoking years, while a positive correlation was found with moderate alcohol consumption and especially with circulating levels of vitamin D, as clearly shown by the multivariate regression analysis. Our study showed that a number of variables are involved in the COVID-19 vaccine antibody response. These findings are very important and can be considered in the light of a future and personalized vaccinology.

Vitamin D status can affect COVID-19 outcomes also in pediatric population

Background

vitamin D influences the immune system and the inflammatory response. It is known that vitamin D supplementation reduces the risk of acute respiratory tract infection. In the last two years, many researchers have investigated vitamin D's role in the pathophysiology of COVID-19 disease.

Results

the findings obtained from clinical trials and systematic reviews highlight that most patients with COVID-19 have decreased vitamin D levels and low levels of vitamin D increase the risk of severe disease. This evidence seems to be also confirmed in the pediatric population.

Conclusions

further studies (systematic review and meta-analysis) conducted on children are needed to confirm that vitamin D affects COVID-19 outcomes and to determine the effectiveness of supplementation and the appropriate dose, duration and mode of administration.

Redclaw crayfish (Cherax quadricarinatus) responds to Vibrio parahaemolyticus infection by activating toll and immune deficiency signaling pathways and transcription of associated immune response genes

In invertebrates, several genes controlled by the Toll and immunodeficiency (IMD) signaling cascade are altered during microbial infection. However, little is known about the expression patterns of innate immune response genes in red-clawed crayfish (Cherax quadricarinatus). In the present study, the transcription of five genes was assessed in C. quadricarinatus challenged with Vibrio parahaemolyticus (V. parahaemolyticus). The expression of Relish, Toll-like receptor (TLR), tumor necrosis factor receptor-related factor 6 (TRAF6), Akirin, and IMD in different tissues and at different time points after infection were assessed. In addition, the Relish gene was amplified, the protein conformation of the Relish gene was predicted, and gene expression changes associated with antimicrobial peptide production in C. quadricarinatus were analyzed using RNA interference (RNAi). During V. parahaemolyticus infection, the transcripts of the above five genes were significantly increased in the hepatopancreas of C. quadricarinatus (P < 0.05). In contrast, TLR was significantly downregulated in muscle tissue at the initial stage of infection (P < 0.05); TRAF6 and IMD were significantly down-regulated throughout infection (P < 0.05); Akirin transcripts had the lowest abundance at 24 h post-infection; Relish, IMD and Akirin genes were significantly up-regulated in gill tissue at the early stage of infection (P < 0.05); only TRAF6 was significantly up-regulated at 6, 24 and 48 h after infection. The Relish gene of C. quadricarinatus is closely related to the Exopalaemon carinicauda. When the Relish gene was knocked down by RNAi, the V. parahaemolyticus challenge showed that the mortality rate of the RANi group was significantly higher than that of the NC group; pathological sections showed that the hepatopancreatic tissue damage was the most severe 12 h after the interference; and the interference significantly inhibited IRF4, NF-κB, ALF, laccase, SOD1, and lectin genes. Therefore, it can be hypothesized that the Toll and IMD pathways are activated in C. quadricarinatus in response to bacterial infection and that genes associated with these pathways are differentially transcribed in different tissues. This study provides insights into the Toll and IMD signaling pathways and the spatiotemporal expression of key genes regulating bacterial infection resistance in C. quadricarinatus.

Vitamin D modulates the expression of Toll-like receptors and pro-inflammatory cytokines without affecting Chikungunya virus replication, in monocytes and macrophages

Chikungunya virus (CHIKV) is a zoonotic arthropod-borne virus that causes Chikungunya fever (CHIKF), a self-limiting disease characterized by myalgia and acute or chronic arthralgia. CHIKF pathogenesis has an important immunological component since higher levels of pro-inflammatory factors, including cytokines and chemokines, are detected in CHIKV-infected patients. In vitro studies, using monocytes and macrophages have shown that CHIKV infection promotes elevated production of pro-inflammatory cytokines and antiviral response factors. Vitamin D3 (VD3) has been described as an important modulator of immune response and as an antiviral factor for several viruses. Here, we aimed to study the effects of VD3 treatment on viral replication and pro-inflammatory response in CHIKV-infected human monocytes (VD3-Mon) and monocyte-derived macrophages differentiated in the absence (MDMs) or the presence of VD3 (VD3-MDMs). We found that VD3 treatment did not suppress CHIKV replication in either VD3-Mon or VD3-MDMs. However, the expression of VDR, CAMP and CYP24A1 mRNAs was altered by CHIKV infection. Furthermore, VD3 treatment alters TLRs mRNA expression and production of pro-inflammatory cytokines, including TNFα and CXCL8/IL8, but not IL1β and IL6, in response to CHIKV infection in both VD3-Mon and VD3-MDMs. While a significant decrease in CXCL8/IL8 production was observed in CHIKV-infected VD3-Mon, significantly higher production of CXCL8/IL8 was observed in CHIKV-infected VD3-MDM at 24 hpi. Altogether, our results suggest that vitamin D3 may play an important role in ameliorating pro-inflammatory response during CHIKV infection in human Mon, but not in MDMs. Although further studies are needed to evaluate the efficacy of VD3; nevertheless, this study provides novel insights into its benefits in modulating the inflammatory response elicited by CHIKV infection in humans.

Impact of 12-Week Moderate-Intensity Aerobic Training on Inflammasome Complex Activation in Elderly Women

Aging often associates with a chronic low-grade inflammatory status that can be consequent to the activation of Toll-like receptors (TLRs) and the downstream NLR family pyrin domain containing 3 (NLRP3) inflammasome and causes a chronic secretion of pro-inflammatory cytokines. Since exercise has known anti-inflammatory effects, we investigated the effect of Nordic walking training on inflammasome activation and downstream effectors in elderly women. A population of elderly women was divided into EXP (n = 29) that completed 12 weeks of the moderate-intensity aerobic training program and CTRL (n = 29), performing no activity. Blood samples were taken before and after the first (T1-pre and T1-post, respectively) and last (T2-pre and T2-post, respectively) exercise unit. Inflammasome activation status was assessed by whole blood NLRP3 and TLR4 expression by RT-qPCR. Serum levels of IL-1β, IL-6, TNFα, and IL-18 cytokines were assayed by multiplex fluorescent beads-based immunoassays or ELISA. NLRP3 and TLR4 levels were reduced 2 folds between T1-pre and T2-pre and induced at T2-post, compared to T2-pre, by 2.6- and 2.9-fold, respectively. A single exercise bout elicited a 1. 38-, 1. 5-, and 1.36-fold rise of IL-1β, TNFα, and IL-6 concentration, respectively, although not significant, at the beginning of the training (T1-pre vs. T1-post), a 1.4-fold decrease for IL-1β and TNFα at the end of the training (T1-pre vs. T2-pre), and a 2-, 1.8- and 1.26-fold increase after the last exercise session (T2-pre vs. T2-post) for the three cytokines. When stratifying the population based on BMI in normal weight (NW) and overweight (OW), NLRP3 and TLR4 expression was affected only in NW. As for inflammatory cytokines, IL-1β was modulated in NW at the beginning of the training, whereas in OW at the end of the training; for TNFα, this time-dependent modulation was significant only in OW. Applied aerobic training affected the resting expression of inflammasome constituents (NLRP3 and TLR4) and levels of downstream effectors (IL-1β, TNFα, and IL-6). However, at the end of the program, participants acquire an acute inflammatory response to exercise that was absent at baseline. Future studies would have to define the molecular mechanisms associated with, and how to potentiate, the exercise-associated inflammatory response.

The Potential of Toll-Like Receptors to Modulate Avian Immune System: Exploring the Effects of Genetic Variants and Phytonutrients

Toll-like receptors (TLRs) are pathogen recognition receptors, and primitive sources of innate immune response that also play key roles in the defense mechanism against infectious diseases. About 10 different TLRs have been discovered in chicken that recognize ligands and participate in TLR signaling pathways. Research findings related to TLRs revealed new approaches to understand the fundamental mechanisms of the immune system, patterns of resistance against diseases, and the role of TLR-specific pathways in nutrient metabolism in chicken. In particular, the uses of specific feed ingredients encourage molecular biologists to exploit the relationship between nutrients (including different phytochemicals) and TLRs to modulate immunity in chicken. Phytonutrients and prebiotics are noteworthy dietary components to promote immunity and the production of disease-resistant chicken. Supplementations of yeast-derived products have also been extensively studied to enhance innate immunity during the last decade. Such interventions pave the way to explore nutrigenomic approaches for healthy and profitable chicken production. Additionally, single-nucleotide polymorphisms in TLRs have shown potential association with few disease outbreaks in chickens. This review aimed to provide insights into the key roles of TLRs in the immune response and discuss the potential applications of these TLRs for genomic and nutritional interventions to improve health, and resistance against different fatal diseases in chicken.

Polymorphisms in genes related to oxidative stress and inflammation: Emerging links with the pathogenesis and severity of Cerebral Cavernous Malformation disease

Cerebral Cavernous Malformation (CCM) is a cerebrovascular disease of genetic origin affecting 0.5% of the population and characterized by abnormally enlarged and leaky capillaries that predispose to seizures, neurological deficits, and intracerebral hemorrhage (ICH). CCM occurs sporadically or is inherited as dominant condition with incomplete penetrance and highly variable expressivity. Three disease genes have been identified: KRIT1 (CCM1), CCM2 and CCM3. Previous results demonstrated that loss-of-function mutations of CCM genes cause pleiotropic effects, including defective autophagy, altered reactive oxygen species (ROS) homeostasis, and enhanced sensitivity to oxidative stress and inflammatory events, suggesting a novel unifying pathogenetic mechanism, and raising the possibility that CCM disease onset and severity are influenced by the presence of susceptibility and modifier genes. Consistently, genome-wide association studies (GWAS) in large and homogeneous cohorts of patients sharing the familial form of CCM disease and identical mutations in CCM genes have led to the discovery of distinct genetic modifiers of major disease severity phenotypes, such as development of numerous and large CCM lesions, and susceptibility to ICH. This review deals with the identification of genetic modifiers with a significant impact on inter-individual variability in CCM disease onset and severity, including highly polymorphic genes involved in oxidative stress, inflammatory and immune responses, such as cytochrome P450 monooxygenases (CYP), matrix metalloproteinases (MMP), and Toll-like receptors (TLR), pointing to their emerging prognostic value, and opening up new perspectives for risk stratification and personalized medicine strategies.

Peritraumatic Vitamin D levels predict chronic pain severity and contribute to racial differences in pain outcomes following Major Thermal Burn Injury

Major thermal burn injuries result in approximately 40,000 hospitalizations in the United States each year. Chronic pain affects up to 60% of burn survivors, Black Americans have worse chronic pain outcomes than White Americans. Mechanisms of chronic pain pathogenesis after burn injury, and accounting for these racial differences, remain poorly understood. Due to socioeconomic disadvantage and differences in skin absorption, Black Americans have an increased prevalence of Vitamin D deficiency. We hypothesized that peritraumatic Vitamin D levels predict chronic pain outcomes after burn injury and contribute to racial differences in pain outcomes. Among burn survivors (n=77, 52% White, 48% Black, 77% male), peritraumatic Vitamin D levels were more likely to be deficient in Blacks vs. Whites (27/37 (73%) vs. 14/40 (35%), p<.001). Peritraumatic Vitamin D levels were inversely associated with chronic post-burn pain outcomes across all burn injury survivors, including those who were and were not Vitamin D deficient, and accounted for approximately 1/3 of racial differences in post-burn pain outcome. Future studies are needed to evaluate potential mechanisms mediating the effect of Vitamin D on post-burn pain outcomes and the potential efficacy of Vitamin D in improving pain outcomes and reducing racial differences.

Vitamin D Modulation of the Innate Immune Response to Paediatric Respiratory Pathogens Associated with Acute Lower Respiratory Infections

Vitamin D is an essential component of immune function and childhood deficiency is associated with an increased risk of acute lower respiratory infections (ALRIs). Globally, the leading childhood respiratory pathogens are Streptococcus pneumoniae, respiratory syncytial virus and the influenza virus. There is a growing body of evidence describing the innate immunomodulatory properties of vitamin D during challenge with respiratory pathogens, but recent systematic and unbiased synthesis of data is lacking, and future research directions are unclear. We therefore conducted a systematic PubMed literature search using the terms “vitamin D” and “Streptococcus pneumoniae” or “Respiratory Syncytial Virus” or “Influenza”. A priori inclusion criteria restricted the review to in vitro studies investigating the effect of vitamin D metabolites on human innate immune cells (primary, differentiated or immortalised) in response to stimulation with the specified respiratory pathogens. Eleven studies met our criteria. Despite some heterogeneity across pathogens and innate cell types, vitamin D modulated pathogen recognition receptor (PRRs: Toll-like receptor 2 (TLR2), TLR4, TLR7 and nucleotide-binding oligomerisation domain-containing protein 2 (NOD2)) expression; increased antimicrobial peptide expression (LL-37, human neutrophil peptide (HNP) 1-3 and β-defensin); modulated autophagosome production reducing apoptosis; and modulated production of inflammatory cytokines (Interleukin (IL) -1β, tumour necrosis factor-α (TNF-α), interferon-ɣ (IFN-ɣ), IL-12p70, IFN-β, Regulated on Activation, Normal T cell Expressed (RANTES), IL-10) and chemokines (IL-8 and C-X-C motif chemokine ligand 10 (CXCL10)). Differential modulation of PRRs and IL-1β was reported across immune cell types; however, this may be due to the experimental design. None of the studies specifically focused on immune responses in cells derived from children. In summary, vitamin D promotes a balanced immune response, potentially enhancing pathogen sensing and clearance and restricting pathogen induced inflammatory dysregulation. This is likely to be important in controlling both ALRIs and the immunopathology associated with poorer outcomes and progression to chronic lung diseases. Many unknowns remain and further investigation is required to clarify the nuances in vitamin D mediated immune responses by pathogen and immune cell type and to determine whether these in vitro findings translate into enhanced immunity and reduced ALRI in the paediatric clinical setting.

Does involucrin have a role in verruca vulgaris? A clinical and immunohistochemical study

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Severe Acute Respiratory Syndrome Coronavirus 2: The Role of the Main Components of the Innate Immune System

At the end of December 2019, the COVID-19 pandemic began in Wuhan of China. COVID-19 affects different people with a wide spectrum of clinical manifestations, ranging from asymptomatic with recovery without hospitalization up to a severe acute respiratory syndrome (SARS). The innate and adaptive immunity appears responsible for the defense against the virus and recovery from the disease. The innate immune system, as the first line of defense, is essential for the detection of virus and subsequent activation of acquired immunity. The innate immune response is carried out by sentinel cells such as monocytes/macrophages and dendritic cells and by receptors known as pattern recognition receptors (PRR). These receptors can recognize various components of the virus, which lead to intracellular signaling and subsequently the synthesis of various cytokines. These cytokines then recruit other immune cells, activate adaptive immune responses, and inhibit viral spreading. The most common receptors include Toll-like receptors, C-type lectin receptors, and RIG-I like receptors. This review describes the current knowledge about the interplay between innate immune responses and SARS-CoV-2 with a focus on the innate immune cells and the role of their receptors in viral RNA recognition, as well as their mechanisms for recognizing SARS-CoV-2.

A comprehensive mechanistic review insight into the effects of micronutrients on toll-like receptors functions

Toll-like receptors (TLRs) are the special proteins receptors for recognition of molecules related to the pathogens. In this way, TLRs and secreted cytokines as a result of TLRs activation are involved in the inflammation pathways. So far, in vivo and in vitro studies have demonstrated that micronutrients (vitamins & minerals) with a broad range of effects on body health, can regulate TLRs signaling pathways. Current review aimed at determining the possible mechanisms of micronutrient effects on TLRs functions. In the aspect of gene expression, micronutrients have inconsistent effects on mRNA level of TLRs which are dependent on time, dose and type of studied TLR. Also, some micronutrients affect gene expression of TLRs signaling mediators namely TLRs adaptors like Myeloid differentiation primary response 88 (MyD88). In the aspect of TLRs signaling pathways, nuclear factor-κB (NF-κB) is an important mediator which is regulated by micronutrients. Also, the regulatory effects of micronutrients on phosphorylation reactions may be effective in the activation/inactivation of TLRs signaling mediators. In addition, zinc can regulate TLRs signaling indirectly via the zinc finger proteins which have contradictory effects on TLRs cascade. In conclusion, the relationship between micronutrients and TLRs signaling is complicated and depends on some known internal, external and genetic factors like form of studied micronutrient, cell type, TLR agonist, dose and time of exposure, inflammation, apoptosis, cell cycle, and environmental factors. Some unknown factors may be effective in TLRs response and as a result additional mechanistic studies are needed to elucidate exact effect of micronutrients on TLRs signaling.

Association of vitamin D status and the risk of cardiovascular disease as assessed by various cardiovascular risk scoring systems in patients with type 2 diabetes mellitus

OBJECTIVE

The aim of the present study was to evaluate the relationship between vitamin D (25[OH]D) status and the risk of cardiovascular disease as assessed by various cardiovascular risk scoring systems such as QRISK2, BNF, ASSING, SCORE, and Framingham in patients with type 2 diabetes mellitus(T2DM).

METHODS

The study included 108 patients with vitamin D insufficiency (25[OH]D ≥ 10-30 ng/mL) and 100 patients with vitamin D deficiency (25[OH]D < 10 ng/mL), who were admitted to the diabetes outpatient clinics due to T2DM and who were aged 45-65 years. QRISK2, BNF, ASSING, SCORE, and Framingham were calculated and compared between the two groups.

RESULTS

HbA1c levels were significantly higher in patients with vitamin D deficiency. Patients with vitamin D deficiency had significantly higher Framingham risk score (p < .001) and significantly lower BNF score (p < .001), whereas other scores did not significantly differ between the groups. There was a moderate, statistically significant correlation between 25[OH]D levels and Framingham risk score in negative direction (r = 0.537) and a weak but statistically significant correlation between 25[OH]D levels and BNF score (r = 0.295). 25[OH]D levels were significantly higher and HbA1c levels were significantly lower in patients with Framingham cardiovascular risk score ≤10%.

CONCLUSION

We found a close relationship with Framingham cardiovascular risk score in diabetic patients with very low serum vitamin D levels. Cardiovascular risk as assessed by the Framingham's scale increases with decreasing 25[OH]D levels. BNF score was negatively correlated with 25[OH]D levels.

Regular Aerobic Exercise and Vitamin D3 Supplementation-Reduced Anthropometric Measures and the Hydrogen Peroxide-Induced Expression of TNF-α in Rats

Introduction: Inflammation, oxidative stress (OS), and obesity are documented to play key roles in the pathogenesis of cardiovascular diseases (CVDs). Accordingly, tumor necrosis factor-α (TNF-α) and hydrogen peroxide (H2 O2 ), as a main innate immunity pro-inflammatory cytokine and a main free radical, respectively, are the main risk factors for CVDs. The present study aimed to evaluate the effects of OS, regular aerobic exercise (RAE), and vitamin D3 (VD3) on the expression of TNF-α in the myocardial cells in a rat model. Methods: In this experimental study, 48 male Wistar rats were divided into 8 groups (6 in each group) including healthy controls, sham (injected with dimethyl sulfoxide [DMSO] + saline), H2 O2 (either 1 or 2 mmol/kg), H2 O2 (1 mmol/kg) + VD3, H2 O2 (2 mmol/kg) + VD3, H2O2 (1 mmol/kg) + RAE, and H2 O2 (2 mmol/kg) + RAE. TNF-α level of myocardial cells was evaluated after 8 weeks using the ELISA technique. Results: The results of the study demonstrated that exposure to 2 mmol/kg of H2 O2 significantly increased TNF-α level of myocardial cells compared to the rats which were exposed to one mmol/ kg H2 O2 (P=0.039). Furthermore, RAE (P=0.040), and the combination of RAE+VD3 (P=0.049) significantly reduced the expression of myocardial TNF-α. Conclusion: In general, VD3 and RAE were found to suppress TNF-α expression induced by H2 O2 in the rat myocardium. Therefore, they can be considered as potential therapeutic interventions for reducing OS-induced inflammation in the damaged myocardial cells.