1,25(OH)2D3 inhibits oxidative stress and monocyte adhesion by mediating the upregulation of GCLC and GSH in endothelial cells treated with acetoacetate (ketosis)

Vitamin D and ischemic stroke - Association, mechanisms, and therapeutics

Confronting the rising tide of ischemic stroke and its associated mortality and morbidity with ageing, prevention and acute management of ischemic stroke is of paramount importance. Mounting observational studies have established a non-linear association of vitamin D status with cardiovascular diseases, including ischemic stroke. Paradoxically, current clinical trials fail to demonstrate the cardiovascular benefits of vitamin D supplementation. We aim to update recent clinical and experimental findings on the role of vitamin D in the disease course of ischemic stroke, from its onset, progression, recovery, to recurrence, and the established and alternative possible pathophysiological mechanisms. This review justifies the necessities to address stroke etiological subtypes and focus on vitamin D-deficient subjects for investigating the potential of vitamin D supplementation as a preventive and therapeutic approach for ischemic stroke. Well-powered clinical trials are warranted to determine the efficacy, safety, timing, target individuals, optimal dosages, and target 25OHD concentrations of vitamin D supplementation in the prevention and treatment of ischemic stroke.

Vitamin D ameliorates Aeromonas hydrophila-induced iron-dependent oxidative damage of grass carp splenic macrophages by manipulating Nrf2-mediated antioxidant pathway

Aeromonas hydrophila (A. hydrophila) is one of major pathogenic bacteria in aquaculture and potentially virulent to grass carp (Ctenopharyngodon idella). As an essential nutrient for fish, vitamin D3 (VD3) has been reported to play a role against oxidative stress, but the exact mechanism remains to be elusive. In this study, we found that A. hydrophila induced ferrugination and macrophage aggregation in the spleen of grass carp. Along this line, using the splenic macrophages as the model, the effects of VD3 on A. hydrophila-caused iron deposition and subsequent injuries were determined. In the context, 1,25D3 (the active form of VD3) significantly reduced cellular free Fe2+, lipid peroxidation and lactic dehydrogenase (LDH) release induced by A. hydrophila in the splenic macrophages, indicating the protective effects of VD3 on A. hydrophila-led to ferroptosis-related injuries. In support of this notion, 1,25D3 was effective in hindering ferroptosis inducers-stimulated LDH release in the same cells. Mechanically, 1,25D3 enhanced iron export protein (ferroportin1) and glutathione peroxidase 4 (GPX4) protein levels, and glutathione (GSH) contents via vitamin D receptor (VDR). Moreover, NF-E2-related factor 2 (Nrf2) pathway mediated the regulation of 1,25D3 on GPX4 protein expression and GSH synthesis. Meanwhile, 1,25D3 maintained the stability of Nrf2 proteins possibly by attenuating its ubiquitination degradation. Furthermore, in vivo experiments showed that 1,25D3 injection could not only improve the survival of fish infected by A. hydrophila, but also enhance GSH amounts and decrease malonaldehyde (MDA) contents and iron deposition in the spleen. In summary, our data for the first time suggest that VD3 is a potential antioxidant in fish to fight against A. hydrophila induced-ferroptotic damages.

A review of the critical role of vitamin D axis on the immune system

In recent years, the physiological and molecular functions of vitamin D (Vit-D) have been deeply investigated. At first, Vit-D was considered a regulator of mineral and skeletal homeostasis. However, due to the extensive-expression pattern of Vit-D receptor (VDR) in almost every non-skeletal cell, Vit-D is considered mainly a multifunctional agent with broad effects on various tissues, notably the immune system. The expression of VDR in immune cells such as dendritic cells, monocyte/macrophage, neutrophils, B cells and T cells has been well demonstrated. Besides, such immune cells are capable of metabolizing the active form of Vit-D which means that it can module the immune system in both paracrine and autocrine manners. Vit-D binding protein (DBP), that regulates the levels and homeostasis of Vit-D, is another key molecule capable of modulating the immune system. Recent studies indicate that dysregulation of Vit-D axis, variations in the DBP and VDR genes, and Vit-D levels might be risk factors for the development of autoimmune disease. Here, the current evidence regarding the role of Vit-D axis on the immune system, as well as its role in the development of autoimmune disease will be clarified. Further insight will be given to those studies that investigated the association between single nucleotide polymorphisms of DBP and VDR genes with autoimmune disease susceptibility.

Clinical and Biochemical Study of Pregnancy Toxemia in Iraqi Ewes

Pregnancy toxemia (PT), also known as ketosis or twin lamb disease, is a group of in-sequence metabolic disorders usually observed in the last pregnancy period of ewes. Blood samples from 60 Awassi ewes were collected, including 50 ewes suffering from PT and 10 healthy ewes (2-8 years old) as a control group. All of them were in their final month of pregnancy from different regions of Salah Aldin Governorate, Iraq. The samples were collected between October 2021 and February 2022. Biochemical analysis of serum concentrations of all parameters was performed using the atomic absorption spectrophotometer, except for the beta-hydroxybutyrate and non-esterified fatty acids that were analyzed by enzyme-linked immunosorbent assay method. The results of the clinical criteria tests for temperature, respiration, and pulse showed nonsignificant differences (P<0.05) in the infected animals, compared to the healthy group. Clinical signs included depression, loss of appetite, weight loss, lying down, odor of ketogenic bodies through breathing, inability to walk, neurological signs, dental grinding, jaundice, blindness, bloat, dystocia, animal death, and fetal death. Based on the results of the biochemical parameters tests of the blood, a significant increase (P<0. 05) was observed in the parameters of the results of beta-hydroxybutyrate, non-esterified fatty acids, triglycerides, total bilirubin, and liver enzymes (ALT, AST, ALP, and GGT) in the animals affected by PT, compared to the control group. However, a significant decrease (P<0.05) was observed in the parameters of glucose, cholesterol, total protein, albumin, and globulin in the affected animals, compared to the healthy group. Concerning the association between disease and oxidative stress criteria, the infected animals showed a substantial (P<0.05) increase in malondialdehyde concentration and a significant (P<0.05) drop in glutathione and superoxide dismutase levels.

Endothelial Glycocalyx Preservation-Impact of Nutrition and Lifestyle

The endothelial glycocalyx (eGC) is a dynamic hair-like layer expressed on the apical surface of endothelial cells throughout the vascular system. This layer serves as an endothelial cell gatekeeper by controlling the permeability and adhesion properties of endothelial cells, as well as by controlling vascular resistance through the mediation of vasodilation. Pathogenic destruction of the eGC could be linked to impaired vascular function, as well as several acute and chronic cardiovascular conditions. Defining the precise functions and mechanisms of the eGC is perhaps the limiting factor of the missing link in finding novel treatments for lifestyle-related diseases such as atherosclerosis, type 2 diabetes, hypertension, and metabolic syndrome. However, the relationship between diet, lifestyle, and the preservation of the eGC is an unexplored territory. This article provides an overview of the eGC's importance for health and disease and describes perspectives of nutritional therapy for the prevention of the eGC's pathogenic destruction. It is concluded that vitamin D and omega-3 fatty acid supplementation, as well as healthy dietary patterns such as the Mediterranean diet and the time management of eating, might show promise for preserving eGC health and, thus, the health of the cardiovascular system.

Vitamin D Deficiency in Both Oral and Systemic Manifestations in SARS-CoV-2 Infection: Updated Review

The specialized literature emphasizes the fact that vitamin D has a potentially beneficial effect in the context of the current COVID-19 pandemic. The purpose of this article is to highlight the role of vitamin D, both prophylactic and curative, in the treatment of patients diagnosed with COVID-19. Even though its relevance is still unknown and causes various controversies, there is currently no specific treatment for patients diagnosed with COVID-19. There are various prevention strategies with new vaccination schedules, but additional randomized and clinical trials are still needed to combat this pandemic. In addition to the systemic manifestations of SARS-CoV-2 infection, oral manifestations of this disease have also been described in the literature. The etiology of oral manifestations associated with COVID-19 infection and vitamin D deficiency remains controversial. In the present studies, oral manifestations such as salivary gland infections, aphthae, erythema, gingivitis, ulcers, etc. have been reported. This is a new topic, and the prevalence of manifestations is described in only a few studies, which is inconsistent with the number of COVID-19 cases reported since the beginning of the pandemic. The clinical symptomatology in patients with current COVID-19 infection is polymorphic. Whether the oral manifestation is directly caused by SARS-CoV-2 or a secondary manifestation remains an important topic to analyze and discuss.

Vitamin D Supplementation in Patients with Juvenile Idiopathic Arthritis

Vitamin D has been implicated in the pathogenesis of skeletal disorders and various autoimmune disorders. Vitamin D can be consumed from the diet or synthesized in the skin upon ultraviolet exposure and hydroxylation in the liver and kidneys. In its bioactive form, vitamin D exerts a potent immunomodulatory effect and is important for bone health. Juvenile idiopathic arthritis (JIA) is a collection of inflammatory joint diseases in children that share the manifestation of inflamed synovium, which can result in growth arrest, articular deformity, bone density loss, and disability. To evaluate the potential effect of vitamin D on JIA disease manifestations and outcomes, we review the role of vitamin D in bone metabolism, discuss the mechanism of vitamin D in modulating the innate and adaptive immune systems, evaluate the clinical significance of vitamin D in patients with JIA, and summarize the supplementation studies.

Vitamin D as therapeutic modulator in cerebrovascular diseases: a mechanistic perspectives

Vitamin D deficiency has been linked to several major chronic diseases, such as cardiovascular and neurodegenerative diseases, diabetes, and cancer, linked to oxidative stress, inflammation, and aging. Vitamin D deficiency appears to be particularly harmful to the cardiovascular system, as it can cause endothelial dysfunctioning and vascular abnormalities through the modulation of various downstream mechanisms. As a result, new research indicates that therapeutic approaches targeting vitamin D inadequacies or its significant downstream effects, such as impaired autophagy, abnormal pro-inflammatory and pro-oxidant reactions, may delay the onset and severity of major cerebrovascular disorders such as stroke and neurologic malformations. Vitamin D modulates the various molecular pathways, i.e., Nitric Oxide, PI3K-Akt Pathway, cAMP pathway, NF-kB Pathway, Sirtuin 1, Nrf2, FOXO, in cerebrovascular disorder. The current review shows evidence for vitamin D's mitigating or slowing the progression of these cerebrovascular disorders, which are significant causes of disability and death worldwide.

Exosomes: Potential Player in Endothelial Dysfunction in Cardiovascular Disease

Exosomes are spherical bilayer membrane vesicles with an average diameter of 40-100 nm. These particles perform a wide range of biological activities due to their contents, including proteins, nucleic acids, lipids, lncRNA, and miRNA. Exosomes are involved in inflammation induction, oxidative stress and apoptosis, which can be effective in endothelial dysfunction. Due to the induction of mentioned processes in the endothelial cells, the intercellular connections are destroyed, cell permeability increases and finally cell efficiency decreases and functional defects occur. Cardiovascular disease (CVDs) are of consequences of endothelial dysfunction. Thus by identifying the exosome signaling pathways, which induce inflammation, oxidative stress, and apoptosis, endothelial dysfunction and subsequently CVDs can be reduced; exosomes can be used for appropriate target therapy.

Association of Serum β-Hydroxybutyrate and Coronary Artery Disease in an Urban Chinese Population

Ketone bodies, including β-hydroxybutyrate (BHB), acetoacetate (AA), and acetone, can substitute and alternate with glucose under conditions of fuel/food deficiency. Ketone-body metabolism is increased in a myriad of tissue-metabolism disorders. Perturbations in metabolism are major contributors to coronary artery disease (CAD). We investigated the association of BHB with CAD. A total of 2,970 people of Chinese Han ethnicity were enrolled. The Gensini score was calculated for all patients who had positive findings. The serum level of BHB and other laboratory parameters were measured. The association of serum levels of metabolites with traditionally risk factors and CAD severity was analyzed. The BHB was found to be associated with some traditional risk factors of CAD and CAD severity, as determined by the Gensini score or the number of diseased regions. Moreover, BHB was associated with the T3/T1 tertiles of the Gensini score after the adjustment for traditional risk factors by multivariable logistic regression analysis. The association of BHB with CAD severity was more obvious in women. Taken together, these data suggest that the circulating BHB level is independently associated with CAD severity, and that this association is more pronounced in women.

Progress in the Relationship between Vitamin D Deficiency and the Incidence of Type 1 Diabetes Mellitus in Children

Type 1 diabetes mellitus (T1DM) is an autoimmune disease, due to a large number of islet β cells damaged, resulting in an absolute lack of insulin, ultimately relying on insulin therapy. Vitamin D is a fat-soluble sterol derivative that not only participates in calcium and phosphorus metabolism but also acts as an immunomodulatory role by binding to nuclear vitamin D receptors to regulate the expression of transcription factors. Increasing evidence has shown that vitamin D has immunoregulation and anti-inflammatory effects, and it may play a role in T cell regulatory responses due to downregulation in the expression of cathepsin G and inhibition of CD4+ T cell activation and protection of β cells from immune attack and is beneficial in decreasing oxidative stress in T1DM patients. Epidemiologic evidence demonstrates involvement of vitamin D deficiency in T1DM pathogenesis, with the immune system improperly targeting and destroying its own islet β cells. In addition, polymorphisms in genes critical for vitamin D metabolism may increase the risk of islet autoimmunity and T1DM. In this paper, the relationship between vitamin D deficiency and the molecular mechanism of T1DM was discussed.

Mechanisms Linking Vitamin D Deficiency to Impaired Metabolism: An Overview

Vitamin D deficiency is a common health problem worldwide. Despite its known skeletal effects, studies have begun to explore its extra-skeletal effects, that is, in preventing metabolic diseases such as obesity, hyperlipidemia, and diabetes mellitus. The mechanisms by which vitamin D deficiency led to these unfavorable metabolic consequences have been explored. Current evidence indicates that the deficiency of vitamin D could impair the pancreatic β-cell functions, thus compromising its insulin secretion. Besides, vitamin D deficiency could also exacerbate inflammation, oxidative stress, and apoptosis in the pancreas and many organs, which leads to insulin resistance. Together, these will contribute to impairment in glucose homeostasis. This review summarizes the reported metabolic effects of vitamin D, in order to identify its potential use to prevent and overcome metabolic diseases.

Attenuation of Oxidative Stress, Interleukin-6, High-Sensitivity C-Reactive Protein, Plasminogen Activator Inhibitor-1, and Fibrinogen with Oral Vitamin D Supplementation for Six Months in Patients with Type 2 Diabetes Mellitus having Vitamin D Deficiency

Objectives  Type 2 diabetes mellitus (T2DM) associated with oxidative stress and inflammation causes endothelial dysfunction, which promotes cardiovascular risk. Vitamin D with its pleiotropic effect is said to protect against cardiovascular risk. However, with vitamin D deficiency being more prevalent in T2DM, the cardiovascular risk may get compounded.

Materials and Methods  An interventional study was conducted on 100 patients with T2DM having vitamin D deficiency (vitamin D < 20 ng/mL), who were given oral supplementation of 2,000 IU/day of vitamin D for a period of 6 months. Serum vitamin D, biomarkers of oxidative stress, malondialdehyde (MDA), oxidized LDL (OxLDL), ferric reducing ability of plasma (FRAP), biomarkers of inflammation, high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), plasminogen activator inhibitor-1 (PAI-1), and fibrinogen were measured at baseline and at the end of the third and sixth month of vitamin D supplementation.

Statistical Analysis  Repeated measures analysis of variance (ANOVA) was applied for comparison between baseline and third- and sixth-month data after vitamin D supplementation. Linear regression by generalized estimating equations (GEE), which grouped repeated measures for each subject and accounted for correlations that may occur from multiple observations within subjects, was applied.

Results  Serum vitamin D levels reached normal levels with a significant decrease in OxLDL, hsCRP, IL-6, PAI-1, and fibrinogen levels, with a significant increase in FRAP ( p  = 0.001) levels at the end of 6 months of vitamin D supplementation. These changes were observed even after correction with glycemic control (HbA1c). However, a significant decrease in MDA was observed only at the end of the sixth month of vitamin D supplementation. Vitamin D levels showed a significant negative association with Ox-LDL, Hs-CRP, IL-6, PAI-1, and fibrinogen, even after adjusting for BMI and statin use ( p  = 0.001).

Conclusion  Supplementation of vitamin D for a period of 6 months in patients with T2DM having vitamin D deficiency is beneficial in the attenuation of oxidative stress and inflammation.

Vitamin D Prevents High Glucose-Induced Lipid Droplets Accumulation in Cultured Endothelial Cells: The Role of Thioredoxin Interacting Protein

Vitamin D (VitD) exerts protective effects on the endothelium, which is fundamental for vascular integrity, partly by inhibiting free radical formation. We found that VitD prevents high glucose-induced Thioredoxin Interacting Protein (TXNIP) upregulation. Increased amounts of TXNIP are responsible for the accumulation of reactive oxygen species and, as a consequence, of lipid droplets. This is associated with increased amounts of triglycerides as the result of increased lipogenesis and reduced fatty acid oxidation. Remarkably, VitD rebalances the redox equilibrium, restores normal lipid content, and prevents the accumulation of lipid droplets. Our results highlight TXNIP as one of the targets of VitD in high glucose-cultured endothelial cells and shed some light on the protective effect of VitD on the endothelium.

The Immunomodulatory Function of Vitamin D, with Particular Reference to SARS-CoV-2

Vaccines are the only way to reduce the morbidity associated to SARS-CoV-2 infection. The appearance of new mutations urges us to increase the effectiveness of vaccines as a complementary alternative. In this context, the use of adjuvant strategies has improved the effectiveness of different vaccines against virus infections such as dengue, influenza, and common cold. Recent reports on patients infected by COVID-19 reveal that low levels of circulating vitamin D correlate with a severe respiratory insufficiency. The immunomodulatory activity of this micronutrient attenuates the synthesis of pro-inflammatory cytokines and at the same time, increases antibody production. Therefore, the present review proposes the use of vitamin D as adjuvant micronutrient to increase the efficacy of vaccines against SARS-CoV-2 infection.

Ethanol extract of Gynura bicolour reduces atherosclerosis risk by enhancing antioxidant capacity and reducing adhesion molecule levels

CONTEXT

Gynura bicolour (Roxb. and Willd.) DC (Asteraceae) leaf is a common vegetable. Ethanol extracts of fresh G. bicolour leaves (GBEE) have several physiological effects, but studies on atherosclerosis are limited.

OBJECTIVE

We investigated the oxidant scavenging ability and vascular adhesion molecule expression of these extracts.

MATERIALS AND METHODS

The antioxidant effects of 0.05-0.4 mg/mL GBEE were analyzed in vitro. Intracellular antioxidant capacity and adhesion molecule levels were detected in EA.hy926 cells pre-treated with 10-100 μg/mL GBEE for 8 h, then TNF-α for 3 h. The antioxidant capacity of red blood cells and the adhesion molecule levels in the thoracic aorta were detected in high-fat diet (HFD)-fed Sprague-Dawley rats treated with GBEE for 12 weeks.

RESULTS

The in vitro EC₅₀ values of GBEE based on its DPPH radical-scavenging ability, reducing power, and ferrous ion-chelating ability were 0.20, 3.21 and 0.49 mg/mL, respectively. In TNF-α-treated EA.hy926 cells, the thiobarbituric acid-reactive substance levels were decreased after 10, 50, or 100 μg/mL GBEE treatments (IC₅₀: 19.1 mg/mL). When HFD-fed rats were co-treated with GBEE, the GBEE-H group exhibited 25% higher glutathione levels than the HFD group (p < 0.05). E-selectin, intercellular adhesion molecule-1, and vascular cell adhesion protein-1 levels were decreased in TNF-α-treated EA.hy926 cells after GBEE treatment (by approximately 11-73%; p < 0.05), and the above three adhesion molecules levels were decreased in HFD-fed rats with combined GBEE treatment (by approximately 30-77%; p < 0.05).

CONCLUSIONS

GBEE can protect the vascular endothelium by reducing adhesion molecule expression and regulating antioxidants. It may have the potential to prevent atherosclerosis.

An evaluation of the relationship between vitamin D level and CTRP-9, tumor necrosis factor-alpha, thiol-disulfide hemostasis in women

OBJECTIVE

Many chronic diseases such as malignancy, cardiovascular diseases, endothelial dysfunction, and autoimmune diseases, which have been shown to be related to vitamin D in various studies; have similar relations with CTRP-9, TNFα, and thiol-disulfide hemostasis. We aimed to contribute to the literature by evaluating the relationship between CTRP-9, TNFα, and thiol-disulfide hemostasis and vitamin D levels, which we thought may have some effects on the pathogenesis of vitamin D deficiency.

METHODS

In our study, 78 female volunteers older than 18 years were included. Volunteers were divided into three groups according to the reference values of vitamin D levels. Biochemical parameters, CTRP-9, TNFα, and thiol/disulfide hemostasis tests taken from all volunteers were studied.

RESULTS

In this study, there was a significant difference in CTRP-9, TNFα, total thiol (TT), native thiol (NT), DIS (disulfide), TT/DIS, and NT/DIS levels in vitamin D groups (p<0.05). There was a significant negative correlation between vitamin D and TNFα and DIS, while a significant positive correlation was found with CTRP-9, TT, NT, TT/DIS, and NT/DIS (p<0.05).

CONCLUSIONS

It was determined that vitamin D deficiency causes a significant decrease in CTRP-9 level and a significant increase in TNFα level, as well as an increase in thiol/disulfide hemostasis in favor of disulfide, which may be a risk factor for increased oxidative stress. We considered that these changes may play mediator roles for many chronic diseases and metabolic disorders that are increasing in frequency due to vitamin D deficiency.

Vitamin D3 Prevents the Deleterious Effects of Testicular Torsion on Testis by Targeting miRNA-145 and ADAM17: In Silico and In Vivo Study

Testicular torsion (TT) is the most common urological emergency in children and young adults that can lead to infertility in many cases. The ischemia-reperfusion (IR) injury due to TT has been implicated in the pathogenesis of testicular damage. The main pathological mechanisms of contralateral injury after ipsilateral TT are not fully understood. In the presented study, we investigated the molecular and microscopic basis of ipsilateral and contralateral testicular injury following ipsilateral testicular torsion detorsion (T/D) and explored the possible protective role of vitamin D3. The biochemical analysis indicated that IR injury following T/D significantly decreased the activity of testicular glutathione peroxidase (GPx) enzyme, level of serum testosterone, serum inhibin B, and expression of testicular miRNA145, while increased the activity of testicular myeloperoxidase (MPO) enzyme, level of testicular malondialdehyde (MDA), level of serum antisperm-antibody (AsAb), and expression of ADAM-17. The histological and semen analysis revealed that torsion of the testis caused damages on different tissues in testis. Interestingly, administration of vitamin D3 prior to the IR injury reversed the deterioration effect of IR injury on the testicular tissues as indicated by biochemical and histological analysis which revealed normal appearance of the seminiferous tubules with an apparent decrease in collagen fiber deposition in both ipsilateral and contralateral testes. Our results revealed that the protective effect of vitamin D3 treatment could be attributed to target miRNA145 and ADAM17 protein. To further investigate these findings, we performed a detailed molecular modelling study in order to explore the binding affinity of vitamin D3 toward ADAM17 protein. Our results revealed that vitamin D3 has the ability to bind to the active site of ADAM17 protein via a set of hydrophobic and hydrophilic interactions with high docking score. In conclusion, this study highlights the protective pharmacological application of vitamin D3 to ameliorate the damages of testicular T/D on the testicular tissues via targeting miRNA145 and ADAM17 protein.

Causal Links between Hypovitaminosis D and Dysregulation of the T Cell Connection of Immunity Associated with Obesity and Concomitant Pathologies

Subclinical inflammation in morbid obesity is associated with immune activation and the development of concomitant diseases. Impaired immune homeostasis and immune cell dysregulation in adipose tissue are associated with phenotypic and functional changes in the pool of T lymphocytes and the development of chronic hypovitaminosis D. Low vitamin D levels in obesity lead to the activation, proliferation and production of pro-inflammatory mediators by T cells. Hypovitaminosis D is the cause of a decrease in the functional potential of regulatory and anti-inflammatory lymphocytes and the maintenance of the inflammatory response. The exact molecular genetic mechanisms of the effect of vitamin D on T lymphocytes have not been fully elucidated. Therefore, uncovering the functional role of T cells and their relationship to vitamin D homeostasis in the context of obesity development may contribute to the development of new pathogenetic methods for clinical prediction of the risk of metabolic, oncologic, autoimmune and infectious complications. The review presents the molecular genetic mechanisms of the effect of vitamin D on adipose tissue resident T lymphocytes and the characteristics of vitamin D receptor expression, and analyzes the phenotypic and functional characteristics of potentially pathogenic T lymphocytes in relation to the development of obesity and its associated complications.

Could Vitamin D Be Effective in Prevention of Preeclampsia?

Prevention of preeclampsia (PE) remains one of the most significant problems in perinatal medicine. Due to the possible unpredictable course of hypertension in pregnancy, primarily PE and the high complication rate for the mother and fetus/newborn, it is urgent to offer pregnant women in high-risk groups effective methods of preventing the PE development or delaying its appearance. In addition, due to the association of PE with an increased risk of developing cardiovascular diseases (CVD) in later life, effective preeclampsia prevention could also be important in reducing their incidence. Ideal PE prophylaxis should target the pathogenetic changes leading to the development of PE and be safe for the mother and fetus, inexpensive and freely available. Currently, the only recognized method of PE prevention recommended by many institutions around the world is the use of a small dose of acetylsalicylic acid in pregnant women with risk factors. Unfortunately, some cases of PE are diagnosed in women without recognized risk factors and in those in whom prophylaxis with acetylsalicylic acid is not adequate. Hence, new drugs which would target pathogenetic elements in the development of preeclampsia are studied. Vitamin D (Vit D) seems to be a promising agent due to its beneficial effect on placental implantation, the immune system, and angiogenic factors. Studies published so far emphasize the relationship of its deficiency with the development of PE, but the data on the benefits of its supplementation to reduce the risk of PE are inconclusive. In the light of current research, the key issue is determining the protective concentration of Vit D in a pregnant woman. The study aims to present the possibility of using Vit D to prevent PE, emphasizing its impact on the pathogenetic elements of preeclampsia development.

Vitamin D, Its Role in Recovery after Muscular Damage Following Exercise

Aside from its role in bone metabolism, vitamin D is a key immunomodulatory micronutrient. The active form of vitamin D (1,25(OH)D) seems to modulate the innate immune system through different mechanisms. The vitamin is involved in the differentiation of monocytes into macrophages, increasing the phagocytic and chemotactic functions of these cells. At the same time, vitamin D enables efferocytosis and prevents immunopathology. In addition, vitamin D is involved in other processes related to immune function, such as inflammation. Regarding muscle tissue, vitamin D plays an active role in muscle inflammatory response, protein synthesis, and regulation of skeletal muscle function. Two mechanisms have been proposed: A direct role of 1,25(OH)D binding to vitamin D receptors (VDRs) in muscle cells and the modulation of calcium transport in the sarcoplasmic reticulum. This second mechanism needs additional investigation. In conclusion, vitamin D seems to be effective in cases of deficiency and/or if there is a great muscular commitment, such as in high intensity exercises.

Melatonin provides protection against cisplatin-induced ovarian damage and loss of fertility in mice

RESEARCH QUESTION

Can melatonin provide non-invasive ovarian protection against damage caused by cis-diamminedichloroplatinum (cisplatin) and preserve fertility in female cancer patients? And if so, what is the possible mechanism?

DESIGN

Athymic BALB/c nude tumour-bearing female mice were used to demonstrate whether melatonin affects the antineoplastic effect when co-administrated with cisplatin. Sexually mature and newborn C57BL/6 female mice were used to evaluate the potential effects of melatonin on the ovarian follicle pool, pregnancy rate and litter number in cisplatin-treated mice. The ovaries underwent immunohistochemical, TdT (terminal deoxynucleotidyl transferase)-mediated dUTP nick-end labelling (TUNEL) and gene array analysis to explore the underlying mechanism. In addition, granulosa cells were isolated to investigate the potential protective mechanism of melatonin.

RESULTS

Melatonin not only enhanced the anti-cancer effect of cisplatin in tumour-bearing nude mice, but also reduced ovarian toxicity and preserved long-term fertility in cisplatin-treated C57BL/6 female mice. When co-administrated, melatonin was able to reduce the DNA damage and toxic effects on lipid peroxidation in the ovaries caused by cisplatin. Specifically, melatonin was able to largely restore lipid peroxidation in granulosa cells and thus prevent ovarian follicles from being depleted.

CONCLUSIONS

Melatonin has the potential to be used as a chemotherapeutic adjuvant to simultaneously improve the outcome of anti-cancer treatment and preserve ovarian function during cisplatin chemotherapy. Notably, its properties of DNA protection and antioxidant effects on follicles may benefit female cancer survivors and prevent premature ovarian failure as well as fertility loss caused by chemotherapy.

Ketogenic Diets and Cardio-Metabolic Diseases

While the prevalence of cardio-metabolic diseases (CMDs) has become a worldwide epidemic, much attention is paid to managing CMDs effectively. A ketogenic diet (KD) constitutes a high-fat and low-carbohydrate diet with appropriate protein content and calories. KD has drawn the interests of clinicians and scientists regarding its application in the management of metabolic diseases and related disorders; thus, the current review aimed to examine the evidences surrounding KD and the CMDs to draw the clinical implications. Overall, KD appears to play a significant role in the therapy of various CMDs, which is manifested by the effects of KDs on cardio-metabolic outcomes. KD therapy is generally promising in obesity, heart failure, and hypertension, though different voices still exist. In diabetes and dyslipidemia, the performance of KD remains controversial. As for cardiovascular complications of metabolic diseases, current evidence suggests that KD is generally protective to obese related cardiovascular disease (CVD), while remaining contradictory to diabetes and other metabolic disorder related CVDs. Various factors might account for the controversies, including genetic background, duration of therapy, food composition, quality, and sources of KDs. Therefore, it's crucial to perform more rigorous researches to focus on clinical safety and appropriate treatment duration and plan of KDs.

Vitamin D Deficiency as a Predictor of a High Prevalence of Coronary Artery Disease in Pancreas Transplant Candidates With Type 1 Diabetes

INTRODUCTION

Pancreas transplantation is a high-risk procedure in terms of cardiovascular complications. Therefore, identification of all cardiovascular risk factors is crucial to prevent cardiovascular complications after pancreas transplantation. Vitamin D deficiency (VDD) appears to be a potential risk factor for coronary artery disease.

OBJECTIVE

To determine the prevalence of VDD in pancreas transplant candidates, and further to examine the relationship between vitamin D and the prevalence of coronary artery disease and lipid profile parameters.

MATERIALS AND METHODS

This is a prospective cross-sectional study. We enrolled consecutive patients with type 1 diabetes eligible for simultaneous pancreas-kidney transplantation or pancreas transplant alone. The laboratory tests included HbA1c, lipid profile, creatinine, and total 25-hydroxyvitamin D (25(OH)D). The diagnosis of coronary artery disease was based on coronary angiography.

RESULTS

The study population included 48 patients. VDD was revealed in 48% of patients and coronary artery disease in 35% of patients. The mean concentration of vitamin D in the entire cohort was 21.3 ± 9.48 ng/ml. The median value of 25(OH)D in patients with coronary artery disease was significantly lower than in patients without coronary artery disease (18.5 (11.6-21.5) vs. 24.8 (18.4-31.8) ng/ml, p = 0.018). There was a significant relationship between VDD and coronary artery disease (OR = 4.36; 95% confidence interval (CI): 1.22-15.64, p = 0.034). A patient's odds of having coronary artery disease while having a sufficient level of vitamin D was 4.36 times lower than if the patient had VDD. There was a significant relationship between VDD and hypertension (OR = 5.91; 95% CI: 1.12-31.20, p = 0.039) and hemodialysis (OR = 4.25; 95% CI: 1.25-14.5, p = 0.023). There was no significant correlation between 25(OH)D and lipid profile.

CONCLUSIONS

VDD is highly prevalent in pancreas transplant candidates with type 1 diabetes. There is a significant relationship between VDD and increased prevalence of coronary disease. The lack of any significant association between serum vitamin D and lipid profile suggests that the relationship between vitamin D and coronary artery disease results from other causes.

Evidence Regarding Vitamin D and Risk of COVID-19 and Its Severity

Vitamin D deficiency co-exists in patients with COVID-19. At this time, dark skin color, increased age, the presence of pre-existing illnesses and vitamin D deficiency are features of severe COVID disease. Of these, only vitamin D deficiency is modifiable. Through its interactions with a multitude of cells, vitamin D may have several ways to reduce the risk of acute respiratory tract infections and COVID-19: reducing the survival and replication of viruses, reducing risk of inflammatory cytokine production, increasing angiotensin-converting enzyme 2 concentrations, and maintaining endothelial integrity. Fourteen observational studies offer evidence that serum 25-hydroxyvitamin D concentrations are inversely correlated with the incidence or severity of COVID-19. The evidence to date generally satisfies Hill's criteria for causality in a biological system, namely, strength of association, consistency, temporality, biological gradient, plausibility (e.g., mechanisms), and coherence, although experimental verification is lacking. Thus, the evidence seems strong enough that people and physicians can use or recommend vitamin D supplements to prevent or treat COVID-19 in light of their safety and wide therapeutic window. In view of public health policy, however, results of large-scale vitamin D randomized controlled trials are required and are currently in progress.

Chronic Kidney Disease as Oxidative Stress- and Inflammatory-Mediated Cardiovascular Disease

Generating reactive oxygen species (ROS) is necessary for both physiology and pathology. An imbalance between endogenous oxidants and antioxidants causes oxidative stress, contributing to vascular dysfunction. The ROS-induced activation of transcription factors and proinflammatory genes increases inflammation. This phenomenon is of crucial importance in patients with chronic kidney disease (CKD), because atherosclerosis is one of the critical factors of their cardiovascular disease (CVD) and increased mortality. The effect of ROS disrupts the excretory function of each section of the nephron. It prevents the maintenance of intra-systemic homeostasis and leads to the accumulation of metabolic products. Renal regulatory mechanisms, such as tubular glomerular feedback, myogenic reflex in the supplying arteriole, and the renin-angiotensin-aldosterone system, are also affected. It makes it impossible for the kidney to compensate for water-electrolyte and acid-base disturbances, which progress further in the mechanism of positive feedback, leading to a further intensification of oxidative stress. As a result, the progression of CKD is observed, with a spectrum of complications such as malnutrition, calcium phosphate abnormalities, atherosclerosis, and anemia. This review aimed to show the role of oxidative stress and inflammation in renal impairment, with a particular emphasis on its influence on the most common disturbances that accompany CKD.

Therapeutic effects of vitamin D on acetic acid-induced colitis in rats

PURPOSE

To analyze the effect of calcitriol treatment on acute colitis in an experimental rat model.

METHODS

A total of 24 adult Sprague Dawley albino rats were randomly separated into 3 equal groups: control group (n:8), colitis group (n:8), calcitriol administered group (n:8). A single dose of acetic acid (1 ml of 4% solution) was administered intrarectally to induce colitis. Group 1 was given 1 ml/kg 0.9% NaCl intraperitoneally; rats belonging to Group 2 were administered calcitriol 1 µg/kg for 5 days.

RESULTS

Plasma tumor necrosis factor alpha, Pentraxin 3, and malondialdehyde levels were significantly lower in the calcitriol administered colitis group than in the standard colitis group (p<0.01). In the Calcitriol group, there was a significant histological improvement in hyperemia, hemorrhage and necrotic areas in the epithelium compared to the placebo group (p <0.000).

CONCLUSION

The findings suggest that calcitriol may be an agent that could be used in acute colitis treatment.

The protective effects of aloperine against ox-LDL-induced endothelial dysfunction and inflammation in HUVECs

Atherosclerosis is a potentially life-threatening cardiovascular disease characterized by chronic endothelial inflammation and the formation of atherosclerotic lesions. Circulating ox-LDL is known to induce atherosclerosis by triggering oxidative stress, the expression of inflammatory mediators and adhesion molecules, as well as downregulating the atheroprotective transcriptional factor KLF2. Aloperine is an alkaloid compound isolated from the plant Sophora alopecuroides. Here, we employed various experimental methods to determine the effects of aloperine on ox-LDL-induced markers of atherosclerosis. DHE staining revealed that aloperine may restore the oxidant/antioxidant balance in HUVECs by reducing the level of ROS and rescuing the reduction in NOQ-1 and GCLC induced by ox-LDL. Aloperine treatment reduced ox-LDL-induced expression of IL-6, MCP-1, VCAM-1, and E-selectin and rescued the reduction in KLF2. Aloperine also downregulated ox-LDL-induced expression of the LOX-1. We also demonstrate that aloperine improved cell viability and inhibited the adhesion of U937 monocytes to HUVECs. Finally, we demonstrate that the effects of aloperine are mediated through the rescue of KLF2 expression via suppression of the phosphorylation of p53 protein. Together, our results implicate the potential of aloperine as a safe and effective antiatherosclerosis treatment.

Vitamin D's Effect on Immune Function

Ever since its discovery by Windhaus, the importance of the active metabolite of vitamin D (1,25-dihydroxyvitamin D₃; 1,25-(OH)2D₃) has been ever expanding. In this review, the attention is shifted towards the importance of the extra-skeletal effects of vitamin D, with special emphasis on the immune system. The first hint of the significant role of vitamin D on the immune system was made by the discovery of the presence of the vitamin D receptor on almost all cells of the immune system. In vitro, the overwhelming effect of supra-physiological doses of vitamin D on the individual components of the immune system is very clear. Despite these promising pre-clinical results, the translation of the in vitro observations to solid clinical effects has mostly failed. Nevertheless, the evidence of a link between vitamin D deficiency and adverse outcomes is overwhelming and clearly points towards avoidance of vitamin D deficiency especially in early life.

Vitamin D and Endothelial Function

Vitamin D is known to elicit a vasoprotective effect, while vitamin D deficiency is a risk factor for endothelial dysfunction (ED). ED is characterized by reduced bioavailability of a potent endothelium-dependent vasodilator, nitric oxide (NO), and is an early event in the development of atherosclerosis. In endothelial cells, vitamin D regulates NO synthesis by mediating the activity of the endothelial NO synthase (eNOS). Under pathogenic conditions, the oxidative stress caused by excessive production of reactive oxygen species (ROS) facilitates NO degradation and suppresses NO synthesis, consequently reducing NO bioavailability. Vitamin D, however, counteracts the activity of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase which produces ROS, and improves antioxidant capacity by enhancing the activity of antioxidative enzymes such as superoxide dismutase. In addition to ROS, proinflammatory mediators such as TNF-α and IL-6 are risk factors for ED, restraining NO and eNOS bioactivity and upregulating the expression of various atherosclerotic factors through the NF-κB pathway. These proinflammatory activities are inhibited by vitamin D by suppressing NF-κB signaling and production of proinflammatory cytokines. In this review, we discuss the diverse activities of vitamin D in regulating NO bioavailability and endothelial function.

Nutritional and environmental contributions to Autism Spectrum Disorders: Focus on nutrigenomics as complementary therapy

The prevalence of autism spectrum disorders (ASD) has risen sharply in the last 30 years, posing a major public health concern and a big emotional and financial challenge for families. While the underlying causes remain to be fully elucidated, evidence shows moderate genetic heritability contribution, but heavy environmental influence. Over the last decades, modern lifestyle has deeply changed our eating, rest, and exercise habits, while exposure to air, water, and food chemical pollution has increased due to indiscriminate use of pesticides, food additives, adjuvants, and antibiotics. The result is a drastic change in the quality of our energy source input, and an overload for antioxidant and detoxification pathways that compromises normal metabolism and homeostasis. Current research shows high prevalence of food selectivity and/or food allergy among children with autism, resulting in essential micronutrient deficits that may trigger or aggravate physical and cognitive symptoms. Nutrigenomics is an emerging discipline that focuses on genotype-micronutrient interaction, and a useful approach to tailor low risk, personalized interventions through diet and micronutrient supplementation. Here, we review available literature addressing the role of micronutrients in the symptomatology of ASD, the metabolic pathways involved, and their therapeutic relevance. Personalized and supervised supplementation according to individual needs is suggested as a complement of traditional therapies to improve outcome both for children with autism and their families.

Serum 25(OH)D concentration and its association with inflammation and oxidative stress in the middle-aged Indian healthy and diabetic subjects

BACKGROUND

Vitamin D deficiency is associated with inflammation and oxidative stress. We have studied the association of 25-hydroxyvitamin D [25(OH)D] with markers of inflammation and oxidative stress.

METHODS

We have recruited total 180 male and female subjects aged between 30 and 50 years and divided them into two groups as control (n = 90) and T2DM (n = 90). We have measured 25(OH)D concentration, markers of inflammation including interleukin (IL)-6, IL-1β, and tumor necrosis factor-α (TNF-α) and markers of oxidative stress including malondialdehyde (MDA) and oxidized low-density lipoprotein (Ox-LDL) by using standard methods.

RESULTS

We stratified control and T2DM groups by 25(OH)D concentration and it indicates that in severe deficiency and sufficiency category IL-6, IL-1β, TNF-α, and Ox-LDL were significantly different while in moderate deficiency category only MDA was significantly different, among control and T2DM groups. In an insufficiency category, IL-6, IL-1β, TNF-α, MDA, and Ox-LDL were significantly different among control and T2DM groups. Correlation analysis indicates a negative correlation of 25(OH)D with IL-6, IL-1β, TNF-α, and Ox-LDL among total subjects. Further, logistic regression analysis demonstrated a significant association of different categories of 25(OH)D with IL-6, IL-1β, TNF-α, and Ox-LDL before and after adjustment to body mass index and waist to hip ratio.

CONCLUSION

This study suggest that vitamin D may have significant implications in the prevention of inflammation and oxidative stress.

Immunomodulatory Effects of Vitamin D in Pregnancy and Beyond

In addition to its role in calcium homeostasis and bone formation, a modulatory role of the active form of vitamin D on cells of the immune system, particularly T lymphocytes, has been described. The effects of vitamin D on the production and action of several cytokines has been intensively investigated in recent years. In this connection, deficiency of vitamin D has been associated with several autoimmune diseases, including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), antiphospholipid syndrome (APS), Hashimoto Thyroiditis (HT), and multiple sclerosis (MS). In a successful pregnancy, the maternal immune response needs to adapt to accommodate the semiallogeneic fetus. Disturbances in maternal tolerance are implicated in infertility and pregnancy complications such as miscarriages (RM) and preeclampsia (PE). It is well-known that a subset of T lymphocytes, regulatory T cells (Tregs) exhibit potent suppressive activity, and have a crucial role in curtailing the destructive response of the immune system during pregnancy, and preventing autoimmune diseases. Interestingly, vitamin D deficiency is common in pregnant women, despite the widespread use of prenatal vitamins, and adverse pregnancy outcomes such as RM, PE, intrauterine growth restriction have been linked to hypovitaminosis D during pregnancy. Research has shown that autoimmune diseases have a significant prevalence within the female population, and women with autoimmune disorders are at higher risk for adverse pregnancy outcomes. Provocatively, dysregulation of T cells plays a crucial role in the pathogenesis of autoimmunity, and adverse pregnancy outcomes where these pathologies are also associated with vitamin D deficiency. This article reviews the immunomodulatory role of vitamin D in autoimmune diseases and pregnancy. In particular, we will describe the role of vitamin D from conception until delivery, including the health of the offspring. This review highlights an observational study where hypovitaminosis D was correlated with decreased fertility, increased disease activity, placental insufficiency, and preeclampsia in women with APS.

New Insights on Low Vitamin D Plasma Concentration as a Potential Cardiovascular Risk Factor

The role of Vitamin D hormone in human health and disease is still debated. Recently, growing attention has been paid to its putative role in cardiovascular system homeostasis with several studies that suggested a correlation between low vitamin D levels and increased cardiovascular risk. Several mechanisms are involved in the development of cardiovascular diseases: systemic inflammation, endothelial dysfunction, arterial hypertension and insulin resistance. In the present paper, we have revised the current literature supporting a role for vitamin D in the development of these pathogenetic processes. Finally, we have evaluated the current evidence linking vitamin D to atherosclerosis and its natural consequence, cardiovascular diseases.

Aqueous Extract of Mori Folium Exerts Bone Protective Effect Through Regulation of Calcium and Redox Homeostasis via PTH/VDR/CaBP and AGEs/RAGE/Nox4/NF-κB Signaling in Diabetic Rats

Purpose: The present study is aimed to explore whether the aqueous extract of Mori Folium (MF) exhibits bone protective effect by regulating calcium and redox homeostasis in diabetic rats, and to identify the signaling pathways involved in this process. Methods: Diabetic rats were established using high-sugar and high-fat diet and streptozotocin (STZ) (30 mg/kg for 3 consecutive days). The serum levels of osteocalcin (OC), insulin-like growth factor-1 (IGF-1), tartrate-resistant acid phosphatase (TRAP), phosphorus (P), calcium (Ca), 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], parathormone (PTH), advanced glycation end products (AGEs), superoxide dismutase (SOD), and malondialdehyde (MDA), total antioxidant capacity (TAC), 8-hydroxy-2'-deoxyguanosine (8-OH-dG), and interleukin 6 (IL-6) were determined by ELISA or biochemical assays. Histopathological alterations in the femurs were evaluated by the stainings of hematoxylin-eosin (H&E) and alizarin red S. In addition, femoral strength was detected by a three-point bending assay, bone microstructure was detected with micro-computer tomography. Bone material properties were examined by Fourier-transform infrared spectroscopy. Furthermore, the expressions of IGF-1, runt-related transcription factor 2 (Runx2), osteoprotegerin (OPG), receptor activator of nuclear factor kappa-B ligand (RANKL), cathepsin K, AGEs, receptor of advanced glycation end products (RAGE), NADPH oxidase 4 (Nox4), and nuclear factor kappa-B (NF-κB) in the femurs and tibias, and the alterations in the levels of calcium-binding protein-28k (CaBP-28k), transient receptor potential V6 (TRPV6), and vitamin D receptor (VDR) in the kidneys and duodenums were determined by western blot and immunohistochemical analysis. Results: Treatment of diabetic rats with MF aqueous extract induces an increase in the levels of OC and IGF-1 as well as a decrease in TRAP level in serum. MF treatment also upregulates the expression of OPG, downregulates the expressions of AGEs, RAGE, Nox4, NF-κB, and RANKL, which leads to improve bone microstructure and strength exhibited by an increase in cortical area ratio, cortical thickness, and trabecular area ratio as well as ultimate load, elastic modulus, and bending stress in the femurs and tibias of diabetic rats. In addition, MF aqueous extract preserves bone material properties by decreasing the ratio of fatty acid/collagen and increasing the ratio of mineral/matrix in the femurs of diabetic rats. Moreover, MF treatment increases the levels of P, Ca, and 1,25(OH)2D3, and decreases the level of PTH in the serum, as well as upregulates the expressions of TRPV6 and VDR in the duodenums and CaBP-28k in the kidneys of diabetic rats. Additionally, MF has ability of rebuilding redox homeostasis and eliminating inflammatory stress by increasing the levels of SOD and TAC as well as decreasing the levels of IL-6, AGEs, MDA, and 8-OH-dG. Conclusions: MF treatment may improve bone quality through maintenance of calcium homeostasis via regulating the PTH/VDR/CaBP signaling, and elimination of oxidative stress via regulating the AGEs/RAGE/Nox4/NF-κB signaling. These results may suggest the potential of MF in preventing the development of diabetic osteoporosis.

Dose-dependent effects of vitamin 1,25(OH)2D3 on oxidative stress and apoptosis

Background The purpose of this study is to examine the dose-dependent effects of vitamin 1,25(OH)2D3 on apoptosis and oxidative stress. Methods In this study, 50 male Balb/c mice were used as control and experiment groups. The mice were divided into 5 groups each consisting of 10 mice. Calcitriol was intraperitoneally administered as low dose, medium dose, medium-high dose and high dose vitamin D groups (at 0.5, 1, 5 and 10 μg/kg, respectively), for three times a week during 14 days. At the end of the study, annexin V was measured by enzyme-linked immunosorbent assay method, and total antioxidant capacity and total oxidant status values were measured by colorimetric method in serum. Hematoxylin eosin staining was performed in liver tissues and periodic acid schiff staining was performed in kidney tissues. Results While comparing the results of medium-high dose (5 μg/kg) and high dose (10 μg/kg) vitamin D administration to that of the control group, it was observed that serum antioxidant status and annexin V levels decreased and glomerular mesenchial matrix ratio increased in kidney (p<0.05). In addition to these findings, in the group receiving high dose vitamin D (10 μg/kg), it was observed that the damage to the liver increased together with the the oxidative stress index values (p<0.05). Conclusions As a result, this study was the first in the literature to report that use of high-dose vitamin D (10 μg/kg) results in oxidant effect, rather than being an antioxidant, and causes severe histopathological toxicity in the liver and kidney.

Vitamin D3 repressed astrocyte activation following lipopolysaccharide stimulation in vitro and in neonatal rats

Vitamin D3 has been reported to be an immunity modulator and high levels of vitamin D3 are correlated with a decreased risk for developing diseases in the central nervous system. Astrocytes are important immune cells and contribute toward inflammation during neurological diseases. The vitamin D receptor has been reported to be expressed in astrocytes; however, the effect of vitamin D3 on astrocyte activation has not been studied. Here, we found that lipopolysaccharide stimulation in astrocytes could enhance the expression of vitamin D receptor and Cyp27B1, which encodes the enzyme for converting vitamin D3 into its active form. Vitamin D3 suppressed the expression of proinflammatory cytokines tumour necrosis factor-α, interleukin-1β, vascular endothelial growth factor, and also TLR4 in activated astrocytes. Astrocyte activation was further found to be suppressed after the administration of vitamin D3 in neonatal rats injected with lipopolysaccharide in vivo. We demonstrated the antiactivation effect of vitamin D3 in astrocytes after lipopolysaccharide stimulation. Considering the function of reactive astrocytes in augmenting inflammatory response in neurodegeneration and brain injury, the finding that vitamin D3 administration may inhibit astrocyte activation may be potentially useful for the treatment of central nervous system disorders.

Oxidative stress in critically ill ventilated adults: effects of vitamin D3 and associations with alveolar macrophage function

Background

Disruptions in redox balance lead to oxidative stress, a promoter of morbidity in critical illness. This study aimed to: 1) characterize the plasma and alveolar thiol/disulfide redox pools, 2) examine their associations with alveolar macrophage phagocytosis, and 3) determine the effect of high dose vitamin D₃ on plasma thiol/disulfide redox.

Methods

Subjects were 30 critically ill, ventilated adults in a double-blind randomized trial of high-dose (250 000 or 500 000 IU) vitamin D₃ or placebo. Baseline bronchoalveolar lavage fluid (BALF) samples were analyzed for determination of alveolar phagocytosis index (PI) and for concentrations of glutathione (GSH), glutathione disulfide (GSSG), cysteine (Cys), cystine (CySS), and their respective redox potentials (EhGSSG and EhCySS). Plasma redox outcomes were assessed at baseline and days 7 and 14.

Results

Baseline plasma Cys was inversely associated with alveolar PI (ρ = −0.69, P=0.003), and E_hCySS was positively associated with PI (ρ = 0.61, P=0.01). Over time, among all subjects there was an increase in plasma GSH levels and a decrease in E_hGSSG (P<0.01 for both), with no difference by treatment group. Vitamin D₃ decreased oxidized plasma GSSG to a more normal state (P for group × time=0.009).

Conclusions

Oxidative stress indicators were positively associated with alveolar macrophage phagocytic function in acutely ill ventilated adults. High-dose vitamin D₃ decreased plasma GSSG concentrations, which suggests that vitamin D can possibly improve the oxidative stress environment.

Inactivation of HMGCL promotes proliferation and metastasis of nasopharyngeal carcinoma by suppressing oxidative stress

Altered metabolism is considered as a hallmark of cancer. Here we investigated expression of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) 2 lyase (HMGCL), an essential enzyme in ketogenesis, which produces ketone bodies by the breakdown of fatty acids to supply energy, in nasopharyngeal carcinoma (NPC). The expression of HMGCL was silenced in NPC tissue. Downregulation of HMGCL in NPC was associated with low intracellular β-hydroxybutyrate (β-HB) production, thereby reducing reactive oxygen species (ROS) generation. Ectopic expression of HMGCL restored β-HB level, associated with suppressed proliferation and colony formation of NPC cells in vitro and decreased tumorigenicity in vivo. HMGCL suppressed the migration and invasion of NPC cells in vitro via mesenchymal-epithelial transition. Furthermore, extracellular β-HB supply suppressed the proliferation and migration of NPC cells. Both intra- and extracellular β-HB exerting a suppressive role in NPC depends on ROS generation. Ketogenesis may be impaired in NPC cells due to lack of HMGCL expression, suggesting that it may be a promising target in NPC therapy.

Vitamin D endocrinology on the cross-road between immunity and metabolism

The effects of vitamin D on the immune function have been recognized for more than a quarter of a century. However, our understanding of the multifactorial nature of the effects of vitamin D at the cellular, molecular and metabolic level in different immune cells of the innate and adaptive immune system has dramatically progressed during the last decades. In this review, we summarize the main metabolic pathways preferentially used in different subsets of macrophages, dendritic cells, T and B cells as well as the immunomodulatory effects of vitamin D on these cells. We will highlight the metabolic reprogramming happening in vitamin D-conditioned tolerogenic dendritic cells. A better knowledge of the dynamics of metabolic states in immune subsets and their possible roles in inflammation and autoimmunity may advance the development of novel immunotherapies. Likewise, the implications of effects of vitamin D on immunometabolism may progress our insights in the nature of immune responses in health and disease.

Multi-dimensional Roles of Ketone Bodies in Fuel Metabolism, Signaling, and Therapeutics

Ketone body metabolism is a central node in physiological homeostasis. In this review, we discuss how ketones serve discrete fine-tuning metabolic roles that optimize organ and organism performance in varying nutrient states and protect from inflammation and injury in multiple organ systems. Traditionally viewed as metabolic substrates enlisted only in carbohydrate restriction, observations underscore the importance of ketone bodies as vital metabolic and signaling mediators when carbohydrates are abundant. Complementing a repertoire of known therapeutic options for diseases of the nervous system, prospective roles for ketone bodies in cancer have arisen, as have intriguing protective roles in heart and liver, opening therapeutic options in obesity-related and cardiovascular disease. Controversies in ketone metabolism and signaling are discussed to reconcile classical dogma with contemporary observations.

Is Vitamin D Deficiency Implicated in Autonomic Dysfunction?

Dysautonomia, dysfunction of the autonomic nervous system, presents with heterogeneous clinical features from an imbalanced regulation of the sympathetic and parasympathetic nervous systems. Low Vitamin D levels can explain the heterogeneous clinical features of migraine headaches, cardiac and gastrointestinal dysfunction, and oxidative stress evident in dysautonomia patients. The role of Vitamin D in modulating pain sensitivity has been recently established. However, there is a lack of research and understanding regarding the association between Vitamin D deficiency and autonomic dysfunction. Vitamin D is a neuroactive hormone that modulates autonomic balance, regulating the sympathetic and parasympathetic nervous systems, and has multisystem benefits. The following review explores the literature and addresses the relationship between Vitamin D deficiency and autonomic dysfunction. Overall, this literature review implicates Vitamin D deficiency in autonomic dysfunction and elucidates the potential therapeutic role of Vitamin D in autonomic disorders. PubMed search was performed for English articles from 1996 to 2016. Following keywords: Vitamin D, autonomic dysfunction and orthostatic hypotension, Vitamin D receptor, migraine and traumatic brain injury, Vitamin D, cardiac and gastrointestinal disease, Vitamin D, glutathione, oxidative stress, and serotonin were included. Only articles reporting primary data relevant to the above question were included in the study.

New Pathogenic Concepts and Therapeutic Approaches to Oxidative Stress in Chronic Kidney Disease

In chronic kidney disease inflammatory processes and stimulation of immune cells result in overproduction of free radicals. In combination with a reduced antioxidant capacity this causes oxidative stress. This review focuses on current pathogenic concepts of oxidative stress for the decline of kidney function and development of cardiovascular complications. We discuss the impact of mitochondrial alterations and dysfunction, a pathogenic role for hyperuricemia, and disturbances of vitamin D metabolism and signal transduction. Recent antioxidant therapy options including the use of vitamin D and pharmacologic therapies for hyperuricemia are discussed. Finally, we review some new therapy options in diabetic nephropathy including antidiabetic agents (noninsulin dependent), plant antioxidants, and food components as alternative antioxidant therapies.