Activation of vitamin D receptor promotes VEGF and CuZn-SOD expression in endothelial cells

Ubiquinone (Coenzyme Q-10) Supplementation Influences Exercise-Induced Changes in Serum 25(OH)D3 and the Methyl-Arginine Metabolites: A Double-Blind Randomized Controlled Trial

Researchers have studied the effects of exercise on serum methyl-arginine and vitamin D metabolites; however, the effects of exercise combined with antioxidants are not well documented. Since oxidative stress affects the metabolism of vitamin D and methyl-arginine, we hypothesised that the antioxidant coenzyme Q10 (CoQ10) might modulate exercise-induced changes. A group of twenty-eight healthy men participated in this study and were divided into two groups: an experimental group and a control group. The exercise test was performed until exhaustion, with gradually increasing intensity, before and after the 21-day CoQ10 supplementation. Blood samples were collected before, immediately after, and 3 and 24 h after exercise. CoQ10, vitamin D metabolites, asymmetric dimethylarginine (ADMA), symmetric dimethylarginine, methylarginine, dimethylamine, arginine, citrulline, and ornithine were analysed in serum samples. CoQ10 supplementation caused a 2.76-fold increase in the concentration of serum CoQ10. Conversely, the 25(OH)D3 concentration increased after exercise only in the placebo group. ADMA increased after exercise before supplementation, but a decrease was observed in the CoQ10 supplementation group 24 h after exercise. In conclusion, our data indicate that CoQ10 supplementation modifies the effects of exercise on vitamin D and methyl-arginine metabolism, suggesting its beneficial effects. These findings contribute to the understanding of how antioxidants like CoQ10 can modulate biochemical responses to exercise, potentially offering new insights for enhancing athletic performance and recovery.

Cytokine storm modulation using cholecalciferol and low dose gamma radiation in Escherichia coli infected mice

This work investigates the efficiency of cholecalciferol and low dose gamma radiation in modulating cytokine storm through their impact on inflammatory and anti-inflammatory cytokine and protecting against lung and liver injuries. Male Swiss albino mice were exposed to 0.2 Gy gamma radiation/week for four consecutive weeks then injected intraperitoneally (i.p) with a single dose of 8.3 × 106 CFU Escherichia coli/g b.w. then injected i.p. with 1.0 mg/kg cholecalciferol (Vit D3) for 7 days starting 4 h after E. coli injection. The results revealed that Cholecalciferol and low dose gamma radiation caused significant depletion in the severity of E. coli infection (colony forming unit per milliliter), log10 of E. coli, Tumor necrosis factor alpha, Interleukin 6, VEGF, alanine aminotransferase, and aspartate aminotransferase levels and significant elevation in IL-10, IL-4, and HO-1. Immunohistochemical analysis of caspase-3 expression in lung tissue section showed low caspase-3 expression in cholecalciferol and low dose gamma radiation treated group. Histopathological examinations were performed in both lung and liver tissues which also emphasis the biochemical findings. Our results exhibit the importance of cholecalciferol and low dose gamma radiation in improving liver function and providing anti-inflammatory response in diseases causing cytokine storm.

Oxidative stress contributes to hypermethylation of Histone H3 lysine 9 in placental trophoblasts from preeclamptic pregnancies

Background and objective

Aberrant epigenetic regulation and increased oxidative stress in the placenta play a significant role in placental pathophysiology and fetal programming in preeclampsia, a hypertensive disorder in human pregnancy. The purpose of the study is to investigate if hypermethylation of histone H3K9 occurs in placental trophoblasts from preeclampsia.

Methods

Trophoblasts were isolated and cultured from 14 placentas, 7 from normotensive pregnant women and 7 from preeclamptic pregnancies. Methylated H3K9 expression and antioxidant superoxide dismutase expression were determined by Western blot. We also examined consequences of oxidative stress and the downstream effects of histone methyltransferase inhibition on H3K9 expression associated with antioxidant CuZn-SOD and Mn-SOD expression in placental trophoblasts.

Results

We found that expression of mono-, di-, and tri-methylation of histone H3 lysine 9 (H3K9me1, H3K9me2 and H3K9me3) was significantly increased, p<0.01, which correlated with downregulation of antioxidant superoxide dismutase CuZn-SOD and Mn-SOD expression, in trophoblasts from preeclamptic placentas compared to those from uncomplicated control placentas. We further demonstrated hypoxia could promote histone H3K9 methylation in placental trophoblasts, and hypoxia-induced upregulation of H3K9me1, H3K9me2 and H3K9me3 expression was reversible when hypoxic condition was removed. In addition, we also uncovered that inhibition of methyltransferase not only prevented hypoxia-induced upregulation of H3K9me1, H3K9me2 and H3K9me3 expression, but also abolished hypoxia-induced downregulation of CuZn-SOD and Mn-SOD expression in placental trophoblasts.

Conclusions

These findings are noteworthy and provide further evidence that increased oxidative stress in the intrauterine environment is likely a mechanism to induce aberrant histone modification in placental trophoblasts in preeclampsia. Moreover, CuZn-SOD and Mn-SOD expression/activity are possibly H3K9 methylation-dependent in placental trophoblasts, which further suggest that oxidative stress and aberrant histone modification have significant impact on placental trophoblasts/fetal programming in preeclampsia.

Emerging role of vitamin D3 in alleviating intestinal structure injury caused by Aeromonas hydrophila in grass carp (Ctenopharyngodon idella)

Bacterial pathogens destroy the structural integrity of functional organs in fish, leading to severe challenges in the aquaculture industry. Vitamin D3 (VD3) prevents bacterial infections and strengthens immune system function via vitamin D receptor (VDR). However, the correlation between VD3/VDR and the structural integrity of functional organs remains unclarified. This study aimed to investigate the influence of VD3 supplementation on histological characteristics, apoptosis, and tight junction characteristics in fish intestine during pathogen infection. A total of 540 healthy grass carp (257.24 ± 0.63 g) were fed different levels of VD3 (15.2, 364.3, 782.5, 1,167.9, 1,573.8, and 1,980.1 IU/kg) for 70 d. Subsequently, fish were challenged with Aeromonas hydrophila, a pathogen that causes intestinal inflammation. Our present study demonstrated that optimal supplementation with VD3 (1) alleviated intestinal structural damage, and inhibited oxidative damage by reducing levels of oxidative stress biomarkers; (2) attenuated excessive apoptosis-related death receptor and mitochondrial pathway processes in relation to p38 mitogen-activated protein kinase signaling (P < 0.05); (3) enhanced tight junction protein expression by inhibiting myosin light chain kinase signaling (P < 0.05); and (4) elevated VDR isoform expression in fish intestine (P < 0.05). Overall, the results demonstrated that VD3 alleviates oxidative injury, apoptosis, and the destruction of tight junction protein under pathogenic infection, thereby strengthening pathogen defenses in the intestine. This finding supports the rationale for VD3 intervention as an essential practice in sustainable aquaculture.

Vitamin D and Its Receptors in Cervical Cancer

Several studies have investigated the relationship between vitamin D (VD) and its receptors (VDR) and the risk of cervical cancer. However, the underlying mechanisms that underpin these associations remain incompletely comprehended. In this review, we analyzed the impacts of VD and VDR on cervical cancer and related mechanisms, and discussed the effects of VD, calcium, and other vitamins on cervical cancer. Our literature research found that VD, VDR and their related signaling pathways played indispensable roles in the occurrence and progression of cervical cancer. Epidemiological studies have established associations between VD, VDR, and cervical cancer susceptibility. Current studies have shown that the inhibitory effect of VD and VDR on cervical cancer may be attributed to a variety of molecules and pathways, such as the EAG potassium channel, HCCR-1, estrogen and its receptor, p53, pRb, TNF-α, the PI3K/Akt pathway, and the Wnt/β-catenin pathway. This review also briefly discussed the association between VDR gene polymorphisms and cervical cancer, albeit a comprehensive elucidation of this relationship remains an ongoing research endeavor. Additionally, the potential ramifications of VD, calcium, and other vitamins on cervical cancer has been elucidated, yet further exploration into the precise mechanistic underpinnings of these potential effects is warranted. Therefore, we suggest that further studies should focus on explorations into the intricate interplay among diverse molecular pathways and entities, elucidation of the mechanistic underpinnings of VDR polymorphic loci changes in the context of HPV infection and VD, inquiries into the mechanisms of VD in conjunction with calcium and other vitamins, as well as investigations of the efficacy of VD supplementation or VDR agonists as part of cervical cancer treatment strategies in the clinical trials.

Protective effects of vitamin D3 (cholecalciferol) on vancomycin-induced oxidative nephrotoxic damage in rats

CONTEXT

Vancomycin (VCM), an important antibiotic against refractory infections, has been used to treat secondary infections in severe COVID-19 patients. Regrettably, VCM treatment has been associated with nephrotoxicity. Vitamin D₃ can prevent nephrotoxicity through its antioxidant effect.

OBJECTIVE

This study tests the antioxidant effect of vitamin D₃ in the prevention of VCM-induced nephrotoxicity.

MATERIALS AND METHODS

Wistar Albino rats (21) were randomly divided into 3 groups: (A) control; (B) VCM 300 mg/kg daily for 1 week; and (C) VCM plus vitamin D₃ 500 IU/kg daily for 2 weeks. All the rats were sacrificed and serum was separated to determine kidney function parameters. Their kidneys were also dissected for histological examination and for oxidative stress markers.

RESULTS

Lipid peroxidation, creatinine, and urea levels decreased significantly (p < 0.0001) in the vitamin D₃-treated group (14.46, 84.11, 36.17%, respectively) compared to the VCM group that was given VCM (MIC<2 μg/mL) only. A significant increase was observed in superoxide dismutase levels in the vitamin D₃-treated group (p < 0.05) compared to rats without treatment. Furthermore, kidney histopathology of the rats treated with vitamin D₃ showed that dilatation, vacuolization and necrosis tubules decreased significantly (p < 0.05) compared with those in the VCM group. Glomerular injury, hyaline dystrophy, and inflammation improved significantly in the vitamin D₃ group (p < 0.001, p < 0.05, p < 0.05, respectively) compared with the VCM group.

DISCUSSION AND CONCLUSIONS

Vitamin D₃ can prevent VCM nephrotoxicity. Therefore, the appropriate dose of this vitamin must be determined, especially for those infected with COVID-19 and receiving VCM, to manage their secondary infections.

Disruption of Vitamin D Signaling Impairs Adaptation of Cerebrocortical Microcirculation to Carotid Artery Occlusion in Hyperandrogenic Female Mice

Vitamin D deficiency contributes to the pathogenesis of age-related cerebrovascular diseases, including ischemic stroke. Sex hormonal status may also influence the prevalence of these disorders, indicated by a heightened vulnerability among postmenopausal and hyperandrogenic women. To investigate the potential interaction between sex steroids and disrupted vitamin D signaling in the cerebral microcirculation, we examined the cerebrovascular adaptation to unilateral carotid artery occlusion (CAO) in intact, ovariectomized, and hyperandrogenic female mice with normal or functionally inactive vitamin D receptor (VDR). We also analyzed the morphology of leptomeningeal anastomoses, which play a significant role in the compensation. Ablation of VDR by itself did not impact the cerebrocortical adaptation to CAO despite the reduced number of pial collaterals. While ovariectomy did not undermine compensatory mechanisms following CAO, androgen excess combined with VDR inactivity resulted in prolonged hypoperfusion in the cerebral cortex ipsilateral to the occlusion. These findings suggest that the cerebrovascular consequences of disrupted VDR signaling are less pronounced in females, providing a level of protection even after ovariectomy. Conversely, even short-term androgen excess with lacking VDR signaling may lead to unfavorable outcomes of ischemic stroke, highlighting the complex interplay between sex steroids and vitamin D in terms of cerebrovascular diseases.

VDR alleviates endothelial cell injury in arteriovenous fistula through inhibition of P66Shc-mediated mitochondrial ROS

To investigate the effects and mechanism of Vitamin D receptor (VDR) signaling on arteriovenous fistula (AVF) endothelial cell injury. Venous tissues of AVF stenosis patients were collected and analyzed, vascular morphology, reactive oxygen species (ROS), and the expression of VDR, P66Shc, fibronectin (FN), collagen-1 (Col-1) were detected. In addition, human umbilical vein endothelial cells (HUVECs) was used in in vitro studies. HUVECs was incubated with transforming growth factor-beta (TGF-β, 50 ng/ml). Aditionally, paricalcitol, VDR overexpression plasmid and Pin1 inhibitor Juglone were used to investigate the regulatory mechanism of VDR in mitochondrial ROS. The parameters of ROS (e.g. MitoSox) and the expression of FN, Col-1 were tested. Moreover, the mitochondrial translocation of P66Shc was analyzed. The expression of VDR was obviously decreased in the venous tissues of AVF stenosis patients. On the contrary, the expression of P66Shc, P-P66Shc, FN, Col-1 and 8-OHdG were increased significantly in the venous tissues of AVF stenosis patients (P < 0.05). In line with this, the level of mitochondrial ROS and the expression of P66Shc, P-P66Shc, FN, Col-1 increased obviously in HUVECs cells under TGF-β condition. Both VDR over-expression plasmid and Pin1 inhibitor Juglone could alleviate TGF-β induced endothelial injury. Mechanistically, VDR overexpression plasmid and Juglone could inhibit the expression of Pin1, and then restrain P66Shc mitochondrial translocation, eventually reduce the level of mitochondrial ROS. Our research indicated that activation of VDR could alleviate venous endothelial cell dysfunction through inhibiting Pin1-mediated mitochondrial translocation of P66Shc and consequently reducing mitochondrial ROS. It suggested that VDR signaling might be an effective target for AVF stenosis treatment.

Vitamin D Receptor Expression Limits the Angiogenic and Inflammatory Properties of Retinal Endothelial Cells

The integrity of retinal endothelial cell (EC) is essential for establishing and maintaining the retinal blood barrier to ensure proper vision. Vitamin D is a hormone with known protective roles in EC function. The majority of vitamin D action is mediated through the vitamin D receptor (VDR). VDR is a nuclear receptor whose engagement by vitamin D impacts the expression of many genes with important roles in regulation of angiogenesis and inflammation. Although many studies have investigated vitamin D-VDR action in cardiovascular protection and tumor angiogenesis, its impact on retinal EC function and regulation of ocular angiogenesis and inflammation is exceedingly limited. We previously showed calcitriol, the active form of vitamin D, is a potent inhibitor of retinal neovascularization in vivo and retinal EC capillary morphogenesis in vitro. Here, using retinal EC prepared from wild-type (Vdr+/+) and VDR-deficient (Vdr-/-) mice, we show that retinal EC express VDR and its expression is induced by calcitriol. The lack of VDR expression had a significant impact on endothelial cell-cell and cell-matrix interactions. Vdr-/- retinal EC proliferated at a slower rate and were more adherent and less migratory. They also exhibited increased expression levels of inflammatory markers driven in part by sustained activation of STAT1 and NF-κB pathways and were more sensitive to oxidative challenge. These changes were attributed, in part, to down-regulation of endothelial nitric oxide synthetase, enhanced hepcidin expression, and increased intracellular iron levels. Taken together, our results indicate that VDR expression plays a fundamental role in maintaining the proper angiogenic and inflammatory state of retinal EC.

Role of Vitamin D Deficiency in the Pathogenesis of Cardiovascular and Cerebrovascular Diseases

Deficiency in vitamin D (VitD), a lipid-soluble vitamin and steroid hormone, affects approximately 24% to 40% of the population of the Western world. In addition to its well-documented effects on the musculoskeletal system, VitD also contributes importantly to the promotion and preservation of cardiovascular health via modulating the immune and inflammatory functions and regulating cell proliferation and migration, endothelial function, renin expression, and extracellular matrix homeostasis. This brief overview focuses on the cardiovascular and cerebrovascular effects of VitD and the cellular, molecular, and functional changes that occur in the circulatory system in VitD deficiency (VDD). It explores the links among VDD and adverse vascular remodeling, endothelial dysfunction, vascular inflammation, and increased risk for cardiovascular and cerebrovascular diseases. Improved understanding of the complex role of VDD in the pathogenesis of atherosclerotic cardiovascular diseases, stroke, and vascular cognitive impairment is crucial for all cardiologists, dietitians, and geriatricians, as VDD presents an easy target for intervention.

Paricalcitol Improves the Angiopoietin/Tie-2 and VEGF/VEGFR2 Signaling Pathways in Adriamycin-Induced Nephropathy

Renal endothelial cell (EC) injury and microvascular dysfunction contribute to chronic kidney disease (CKD). In recent years, increasing evidence has suggested that EC undergoes an endothelial-to-mesenchymal transition (EndoMT), which might promote fibrosis. Adriamycin (ADR) induces glomerular endothelial dysfunction, which leads to progressive proteinuria in rodents. The activation of the vitamin D receptor (VDR) plays a crucial role in endothelial function modulation, cell differentiation, and suppression of the expression of fibrotic markers by regulating the production of nitric oxide (NO) by activating the endothelial NO synthase (eNOS) in the kidneys. This study aimed to evaluate the effect of paricalcitol treatment on renal endothelial toxicity in a model of CKD induced by ADR in rats and explore mechanisms involved in EC maintenance by eNOS/NO, angiopoietins (Angs)/endothelium cell-specific receptor tyrosine kinase (Tie-2, also known as TEK) and vascular endothelial growth factor (VEGF)-VEGF receptor 2 (VEGFR2) axis. The results show that paricalcitol attenuated the renal damage ADR-induced with antiproteinuric effects, glomerular and tubular structure, and function protection. Furthermore, activation of the VDR promoted the maintenance of the function and structure of glomerular, cortical, and external medullary endothelial cells by regulating NO production. In addition, it suppressed the expression of the mesenchymal markers in renal tissue through attenuation of (transforming growth factor-beta) TGF-β1/Smad2/3-dependent and downregulated of Ang-2/Tie-2 axis. It regulated the VEGF/VEGFR2 pathway, which was ADR-deregulated. These effects were associated with lower AT1 expression and VDR recovery to renal tissue after paricalcitol treatment. Our results showed a protective role of paricalcitol in the renal microvasculature that could be used as a target for treating the beginning of CKD.

Effects of dietary vitamin D3 supplementation on the growth performance, tissue Ca and P concentrations, antioxidant capacity, immune response and lipid metabolism in Litopenaeus vannamei larvae

An 8-week feeding trial was conducted to investigate the effects of dietary vitamin D3 supplementation on the growth performance, tissue Ca and P concentrations, antioxidant capacity, immune response and lipid metabolism in Litopenaeus vannamei larvae. A total of 720 shrimp (initial weight 0·50 ± 0·01 g) were randomly distributed into six treatments, each of which had three duplicates of forty shrimp per duplicate. Six isonitrogenous and isolipidic diets were formulated to contain graded vitamin D3 (0·18, 0·23, 0·27, 0·48, 0·57 and 0·98 mg/kg of vitamin D3, measured) supplementation levels. The results revealed that L. vannamei fed diet containing 0·48 mg/kg of vitamin D3 achieved the best growth performance. Compared with the control group, supplementing 0·48 mg/kg of vitamin D3 significantly increased (P < 0·05) the activities of catalase, total antioxidative capacity, alkaline phosphatase and acid phosphatase in serum and hepatopancreas. Expression levels of antioxidant and immune-related genes were synchronously increased (P < 0·05). Carapace P and Ca concentrations were increased (P < 0·05) with the increased vitamin D3 supplementation levels. Further analysis of lipid metabolism-related genes expression showed that shrimp fed 0·48 mg of vitamin D3 per kg diet showed the highest value in the expression of lipid synthesis-related genes, while shrimp fed 0·98 mg of vitamin D3 per kg diet showed the highest value in the expression of lipolysis-related genes. In conclusion, the results of present study indicated that dietary supplementation of 0·48 mg/kg of vitamin D3 could increase Ca and P concentrations, improve antioxidant capacity and immune response, and influence lipid metabolism in L. vannamei.

Skin pigmentation is negatively associated with circulating vitamin D concentration and cutaneous microvascular endothelial function

Darkly pigmented individuals are at the greatest risk of hypovitaminosis D, which may result in microvascular endothelial dysfunction via reduced nitric oxide (NO) bioavailability and/or increased oxidative stress and inflammation. We investigated the associations among skin pigmentation (M-index; skin reflectance spectrophotometry), serum vitamin D concentration [25(OH)D], circulating inflammatory cytokine (TNF-α, IL-6, and IL-10) concentrations, and the NO contribution to local heating-induced cutaneous vasodilation (%NO-mediated vasodilation) in a diversely pigmented cohort of young adults. An intradermal microdialysis fiber was placed in the forearms of 33 healthy adults (14 men/19 women; 18-27 yr; M-index, 30-81 AU) for local delivery of pharmacological agents. Lactated Ringer's solution was perfused through the fiber during local heating-induced (39°C) cutaneous vasodilation. After attaining stable elevated blood flow, 15 mM NG-nitro-l-arginine methyl ester (l-NAME; NO synthase inhibiter) was infused to quantify %NO-mediated vasodilation. Red cell flux was measured (laser-Doppler flowmetry; LDF) and cutaneous vascular conductance (CVC = LDF/MAP) was normalized to maximal (%CVCmax; 28 mM sodium nitroprusside + 43°C). Serum [25(OH)D] and circulating cytokines were analyzed by ELISA and multiplex assay, respectively. M-index was negatively associated with [25(OH)D] (r = -0.57, P < 0.0001) and %NO-mediated vasodilation (r = -0.42, P = 0.02). Serum[25(OH)D] was positively related to %NO (r = 0.41, P = 0.02). Controlling for [25(OH)D] weakened the association between M-index and %NO-mediated dilation (P = 0.16, r = -0.26). There was a negative curvilinear relation between [25(OH)D] and circulating IL-6 (r = -0.56, P < 0.001), but not TNF-α or IL-10 (P ≥ 0.14). IL-6 was not associated with %NO-mediated vasodilation (P = 0.44). These data suggest that vitamin D insufficiency/deficiency may contribute to reduced microvascular endothelial function in healthy, darkly pigmented young adults.NEW & NOTEWORTHY Endothelial dysfunction, an antecedent to hypertension and overt CVD, is commonly observed in otherwise healthy Black adults, although the underlying causes remain unclear. We show that reduced vitamin D availability with increasing degrees of skin pigmentation is associated with reduced microvascular endothelial function, independent of race or ethnicity, in healthy young adults. Greater prevalence of vitamin D deficiency in more darkly pigmented individuals may predispose them to increased risk of endothelial dysfunction.

Aberrant endothelial expression of hnRNPC1/C2 and VDR and reduced maternal vitamin D levels in women with preeclampsia

Vitamin D deficiency is a widespread health problem globally and vitamin D deficiency/ insufficiency in pregnancy is a risk factor for preeclampsia, a hypertensive disorder in human pregnancy. Vitamin D elicits its biological effects through binding to its receptor VDR. In the present study, we determined maternal vascular expression of VDR and hnRNPC1/C2, a native repressor of VDR, in subcutaneous adipose tissue from women with normal pregnancy and preeclampsia. Maternal antenatal and postnatal vitamin D levels were measured. We found that hnRNPC1/C2 expression was markedly increased, while VDR expression was markedly reduced, in maternal vessel endothelium and smooth muscle cells from women with preeclampsia compared to that from normal pregnant controls. Reduced VDR expression was relevant to low maternal antenatal and postnatal vitamin D levels in women with preeclampsia. Using human umbilical vein endothelial cells (HUVECs) as an endothelial model, we further investigated the role of hnRNPC1/C2-mediated VDR expression in endothelial cells, and tested effect of hnRNPC1/C2 inhibition on endothelial response to bioactive vitamin D, 1,25(OH)₂D₃. Our results showed that inhibition of hnRNPC1/C2 by hnRNPC1/C2 siRNA resulted in not only an increase in endothelial VDR expression, but further improved endothelial response to 1,25(OH)₂D₃. These findings indicate that aberrant hnRNPC1/C2 expression may contribute to reduced vascular expression of VDR in women with preeclampsia and suggest that hnRNPC1/C2 could be a target for improving vascular endothelial cell response to vitamin D.

Dietary vitamin K3 activates mitophagy, improves antioxidant capacity, immunity and affects glucose metabolism in Litopenaeus vannamei

An 8-week feeding experiment was conducted to appraise the influence of dietary vitamin K₃ on the growth performance, antioxidant capacities, immune responses, mitophagy and glucose metabolism in Litopenaeus vannamei. Six diets containing graded dietary vitamin K₃ (0.40(control), 9.97, 20.29, 39.06, 79.81 and 156.02 mg kg^-1 of vitamin K₃, respectively) levels were formulated. A total of 900 shrimp with 0.90 g initial weight were randomly assigned to six diets with three replications. Our results revealed that diets supplemented with 9.97-156.02 mg kg^-1 vitamin K₃ didn't affect the growth performance in L. vannamei. In general, compared with the control group, 39.06 mg kg^-1 vitamin K₃ group significantly increased (P < 0.05) the total antioxidative capacity, and the activities of catalase, glutathione, nitric oxide synthase, alkaline phosphatase and acid phosphatase in serum and hepatopancreas. 39.06 mg kg^-1 vitamin K₃ group significantly decreased (P < 0.05) the malondialdehyde in serum and hepatopancreas. The mRNA levels of antioxidant and immune related genes were increased synchronously (P < 0.05). In addition, 39.06 mg kg^-1 vitamin K₃ group increased glycogen content and levels of mitophagy (pink1, ampkα, parkin, lc3, atg13, atg12) genes. Expression levels of glucose transport related gene (glut1), glycolysis related genes (hk, pfk), glycogen synthesis related genes (gsk-3β, gys), insulin-like peptides (ILPs)/AKT/PI3K pathway related genes (insr, irsl, akt, pi3k, pdpk1) were increased in the hepatopancreas of 39.06 mg kg^-1 vitamin K₃ group. In conclusion, the present results indicated that although dietary supplementing vitamin K₃ had no influence on the growth performance, 39.06 mg kg^-1 vitamin K₃ could activate ampkα/pink1/parkin mediated mitophagy, improve antioxidant capacity and immune response. Moreover, vitamin K₃ could trigger ILPs/AKT/PI3K signaling pathways and influence glucose metabolism in L. vannamei. This finding would help to advance the field of vitamin K₃ nutrition and guide the development of future crustacean feeds.

Histopathological role of vitamin D deficiency in recurrent/chronic tonsillitis pathogenesis: Vascular epithelial growth factor-mediated angiogenesis in tonsil

Objectives

Our aim in this study is to reveal the role of vitamin D deficiency in the pathogenesis of recurrent/chronic tonsillitis and to determine the expression of vascular epithelial growth factor (VEGF).

Material and Methods

This study was conducted between September and February. Thirty‐two patients between the ages of 3 and 35 (mean age 9.71) with recurrent episodes of chronic tonsillitis were selected. Patients were divided into four groups according to their 25OHD levels. Patients with 25OHD levels 0–10 ng/ml were determined as Group 1, 11–20 ng/ml Group 2, 21–30 ng/ml Group 3, and 31–50 ng/ml control Group 4. Routine histological tissue sampling was performed for histopathological evaluation of the tonsillar tissues under light microscope (LM). Five micron sections were taken from the paraffin blocks and stained with Hematoxylin Eosin (HE) and Trichrome Masson (TCM). VEGF expression was examined immunohistochemically for each group.

Results

Our analysis showed VEGF expression in all study groups (32 tonsillar tissues). Group 1 and Group 2 histopathological scores were significantly higher than the other groups (p < .001). There were significant differences in VEGF expressions between the four groups (p < .001). 25OHD levels of the patients in Groups 1 and 2 with strong VEGF expression were significantly lower than the other groups (p < .001).

Conclusions

In conclusion, this study showed an increased angiogenesis in tonsil and an increase in VEGF expression of the tonsillar surface epithelium when blood serum 25OHD levels <20 ng/ml.

The peculiar role of vitamin D in the pathophysiology of cardiovascular and neurodegenerative diseases

Vitamin D is a hormone with both genomic and non-genomic actions. It exerts its activity by binding vitamin D receptor (VDR), which belongs to the superfamily of nuclear receptors and ligand-activated transcription factors. Since VDR has been found in various tissues, it has been estimated that it regulates approximately 3% of the human genome. Several recent studies have shown pleiotropic effects of vitamin D in various processes such as cellular proliferation, differentiation, DNA repair and apoptosis and its involvement in different pathophysiological conditions as inflammation, diabetes mellitus, and anemia. It has been suggested that vitamin D could play an important role in neurodegenerative and cardiovascular disorders. Moderate to strong associations between lower serum vitamin D concentrations and stroke and cardiovascular events have been identified in different analytic approaches, even after controlling for traditional demographic and lifestyle covariates. The mechanisms behind the associations between vitamin D and cerebrovascular and cardiologic profiles have been widely examined both in animal and human studies. Optimization of vitamin D levels in human subjects may improve insulin sensitivity and beta-cell function and lower levels of inflammatory markers. Moreover, it has been demonstrated that altered gene expression of VDR and 1,25D3-membrane-associated rapid response steroid-binding (1,25D3-MARRS) receptor influences the role of vitamin D within neurons and allows them to be more prone to degeneration. This review summarizes the current understanding of the molecular mechanisms underlying vitamin D signaling and the consequences of vitamin D deficiency in neurodegenerative and cardiovascular disorders.

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.

Beneficial Role of Vitamin D on Endothelial Progenitor Cells (EPCs) in Cardiovascular Diseases

Cardiovascular diseases (CVDs) are the leading cause of death in the world. Endothelial progenitor cells (EPCs) are currently being explored in the context of CVD risk. EPCs are bone marrow derived progenitor cells involved in postnatal endothelial repair and neovascularization. A large body of evidence from clinical, animal, and in vitro studies have shown that EPC numbers in circulation and their functionality reflect endogenous vascular regenerative capacity. Traditionally vitamin D is known to be beneficial for bone health and calcium metabolism and in the last two decades, its role in influencing CVD and cancer risk has generated significant interest. Observational studies have shown that low vitamin D levels are associated with an adverse cardiovascular risk profile. Still, Mendelian randomization studies and randomized control trials (RCTs) have not shown significant effects of vitamin D on cardiovascular events. The criticism regarding the RCTs on vitamin D and CVD is that they were not designed to investigate cardiovascular outcomes in vitamin D-deficient individuals. Overall, the association between vitamin D and CVD remains inconclusive. Recent clinical and experimental studies have demonstrated the beneficial role of vitamin D in increasing the circulatory level of EPC as well as their functionality. In this review we present evidence supporting the beneficial role of vitamin D in CVD through its modulation of EPC homeostasis.

Expression profile of the Kisspeptin/Kiss1r system and angiogenic and immunological mediators in the ovary of cyclic and pregnant cats

The Kisspeptin/Kiss1r system has been studied in mammalian ovaries. However, there are still no studies on the modulation of this system and its relationship with angiogenic and immunological mediators in the ovary of domestic cats, especially during pregnancy. We evaluated the expression of Kisspeptin/Kiss1r and angiogenic and immunological mediators during folliculogenesis, luteogenesis and luteal regression of cyclic and pregnant cats. The ovary exhibited moderate to intense expression for Kiss1, VEGF, Flk-1, INFγ and MIF in oocytes and the follicular wall, while Kiss1r expression was low in granulosa cells. In these cells, there was also a greater expression of Kiss1, INFγ and MIF, mainly in secondary follicles, while tertiary and preovulatory follicles exhibited greater expression of VEGF and Flk-1 in this layer. In luteogenesis, Kiss1 immunostaining was higher in mature corpora lutea (MCL) of pregnant cats compared to vacuolated CL (VCL) and corpus albicans (CA). Pregnancy also increased the luteal gene expression of Kiss1 as well as Kiss1, Kiss1r, Flk-1, and MIF immunostaining in MCL, while reduced the area of VEGF expression in VCL and luteal mRNA expression of Mif when compared to non-pregnant animals. In addition, positive gene correlation between Kiss1r and Mif was observed in the CL. Kiss1, Kiss1r, Vegf and Mif expression were lower in the CA of cats in anestrus. These findings reveal that the expression of Kisspeptin/Kiss1r and angiogenic and immunological mediators, in the ovary of domestic cats, depend on the follicular and luteal stage, and the luteal expression of these mediators is influenced by pregnancy.

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.

Early Changes of VEGF Levels After Zoledronic Acid in Women With Postmenopausal Osteoporosis: A Potential Role of Vitamin D

Zoledronic acid (Zol) is a widely used intravenous aminobisphosphonate to treat both benign and malignant skeletal diseases, and bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a serious side effect whose pathophysiology remains poorly understood. Vascular Endothelial Growth Factor (VEGF) has been recognized to mediate BRONJ in cancer patients undergoing Zol treatment, however data on VEGF are lacking in patients with osteoporosis. Increasing evidences demonstrate that vitamin D influences VEGF levels. The aim of this study was to investigate the influence of Zol on VEGF levels and the possible role for vitamin D on the Zol mediated changes of VEGF concentration in women with postmenopausal osteoporosis. Twenty-eight postmenopausal women with osteoporosis were enrolled and randomized into two groups to receive Zol (5 mg) or placebo. At baseline, at day-3 and day-30 VEGF serum levels were measured; bone turnover markers, 25-hydroxyvitamin D [25(OH)D] and serum calcium were evaluated at baseline. In Zol-treated women, VEGF increased significantly on day-3, and then decreased on day-30. In the Zol-treated women, the percent change of VEGF levels between baseline and day-30 (-18% at day-30 vs. baseline, p = 0.01) was significantly associated with serum 25(OH)D values (r = 0.29, p = 0.028). At a stepwise multiple regression analysis, after correcting for age, BMI, time since menopause, femoral neck BMD, osteocalcin, C-terminal telopeptide of type 1 collagen, and baseline VEGF levels, 25(OH)D levels were independently associated with VEGF change (β = 1.7, SE = 0.71, p = 0.03). For the first time, we detected early modifications of circulating VEGF in postmenopausal women receiving Zol for osteoporosis, identifying a vitamin D-dependent modulation of these changes.

Maternal Vit D supplementation in AMA mice and the role of Vit D/VDR signaling in the offspring's cognition

OBJECTIVE

To explore the molecular mechanism underlying the effect of maternal vitamin D (Vit D) supplementation before pregnancy in advanced maternal age (AMA) mice on the offspring's cognitive function.

METHODS

Thirty-two-week-old female mice either received 10 IU/g body weight vitamin D₃ dissolved in 200 μl corn oil (32W+VD group), or 200 μl corn oil (32W group) per day for one week. Another group of eight-week-old female mice received the same amount of corn oil as 32W group was set as normal reproductive age control (8W group). Then the three groups of female mice were mating with ten-week-old male mice at 2:1 ratio, the offspring were weaned at the age of 3 weeks and housed until the age of 6 weeks. Vit D metabolites and enzymes involved in Vit D metabolism were measured in both mothers and their offspring. Vit D receptor (VDR) and synaptic markers were determined in the offspring hippocampus. Vit D response elements in HIF-1α promoter were predicted, and VDR transcriptional target genes and related signaling molecules were also detected.

RESULTS

Vit D intervention markedly improved the serum 1,25 dihydroxy vitamin D₃ (1,25(OH)₂D₃) concentration in early pregnancy, middle pregnancy and late pregnancy stages in AMA mice. The hippocampal 1,25(OH)₂D₃ levels in the offspring showed the similar pattern. Subsequently, the expression of Cyp27b1, the gene encoding enzyme that converts 25(OH)D₃ to 1,25(OH)₂D₃, in the hippocampus of the offspring from AMA mice was significantly lower than that of the offspring from normal female mice, and was restored by Vit D supplementation. VDR (Vit D receptor), which mediates the cellular actions of active 1,25(OH)₂D₃, was also rescued by Vit D supplementation, especially in dentate gyrus (DG) region of hippocampus. Concurrently, the synaptic markers NR1, NR2A, and PSD-93 in the hippocampus were reversed in 32W+VD group. Finally, we found that Vit D supplementation may affect PI3K-AKT, PLC-ERK1/2, and p38-MAPK signaling molecules by mediating HIF1α expression via VDR.

CONCLUSION

Our findings highlight the biological significance of maternal Vit D supplementation before pregnancy on Vit D metabolism, and signaling molecules in the offspring, underlying the potential mechanism of the cognitive impairment in the offspring born to AMA mice.

Effects of Parenteral Vitamin D3 Supplementation on Hematological Parameters of Healthy Holstein Bulls

Vitamin D has been shown to play physiological functions beyond calcium and phosphorus homeostasis and control bone metabolism in the body since its cellular receptors are present in numerous tissues. A total of 20 healthy bulls were divided into four groups to evaluate the effect of different doses of vitamin D3 on the number of bovine blood cells. Groups A, B, C, and D received 11,000, 22,000, 33,000, and 44,000 units/kg of vitamin D3, respectively. The control group was injected with 10 ml of physiological saline intramuscularly. Blood samples were taken before the injection, as well as 2, 4, and 6 days after the injection; furthermore, the white blood cell counts (including granulocytes and lymphocytes), hematocrit, haemoglobin, and platelets were examined by a cell counter. The results showed that vitamin D could cause leukopenia (e.g., neutropenia and lymphopenia), thrombocytopenia, as well as an increase in hematocrit and hemoglobin levels in the blood. Although the mentioned increase or decrease is largely dose- and time-dependent, the first and best group to indicate this is group B. To find the second group, the investigation of the long-term effects of injections, especially in high doses, and evaluation of different tests are required with larger groups over a longer period.

Calcitriol Treatment Attenuates Uric Acid-Induced Kidney Injury via Super Oxide Dismutase-1 (SOD-1) Upregulation and Fibrosis Reduction

Background

Hyperuricemia induces nephropathy through the mediation of oxidative stress, tubular injury, inflammation, and fibrosis. The high uric acid level is associated with the reduction of vitamin D levels. However, the reno-protective effects of this vitamin in hyperuricemia condition remain unknown. This study aimed to elucidate calcitriol treatment in a uric acid-induced hyperuricemia mice model.

Methods

: Uric acid (125 mg/kg body weight [BW]) was administered intraperitoneally for 7 (UA7) and 14 (UA14) days. Calcitriol (0.5 g/kg BW) was intraperitoneally injected for the following seven days, after 14 days of uric acid induction (UA14VD7 group). The control group received NaCl 0.9%, by the same route. Serum creatinine was measured using calorimetric method, and uric acid levels were assessed using enzymatic calorimetric assay. Tubular injury and fibrosis were assessed using PAS and Sirius red staining. RT-PCR and real-time reverse transcription PCR were carried out for the analyses of SOD-1, Collagen-1, and TGF-1 mRNA expression in the kidney. Immunostaining of super oxide dismutase type 1 (SOD-1) was performed to detect its expression in the kidney.

Results

Uric acid and creatinine levels markedly increased in UA14 groups, followed by an exacerbation of tubular injury. RT-PCR revealed the upregulation of Collagen-1 and TGF-1, along with the downregulation of SOD-1. Calcitriol treatment attenuated the injury with reducing uric acid and creatinine levels, as well as tubular injury. This was associated with lower Collagen-1 and TGF-1 mRNA expression compared to the UA7 and UA14 groups. SOD-1 was upregulated in epithelial cells in the UA14VD7 group.

Conclusion

Calcitriol treatment after uric acid induction may attenuate kidney injury through upregulation of SOD-1 and downregulation of Collagen-1 and TGF-1 gene expression.

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.

The Role of Micronutrients in the Pathogenesis of Alcohol-Related Liver Disease

AIMS

Chronic alcohol consumption may result in liver injury and chronic liver disease, but other factors are likely to influence disease progression. Malnutrition, specifically micronutrient deficiency, is frequently associated with both alcohol use disorder and chronic liver disease. We hypothesize that micronutrient deficiencies may affect the progression of liver disease in this population.

METHODS

Systematic integrative review of the medical literature; electronic search of MEDLINE 1950-2021; studies investigating role of any micronutrient in the acceleration of alcohol-related liver injury in humans or animals. Studies which specifically related to alcoholic hepatitis were excluded. Outcomes were extracted and recorded in tabulated form and discussed narratively.

RESULTS

We identified 46 studies investigating the role of micronutrient deficiencies in the pathogenesis of alcohol-related liver disease. Specific micronutrients which were identified included folic acid or related B vitamins (n = 9 studies), Vitamin D (n = 9 studies), magnesium (n = 8 studies), zinc (n = 8 studies) and selenium (n = 12 including one systematic review). Observational evidence suggests a potential role of magnesium deficiency in accelerating alcohol-related liver injury with weak or negative evidence for other micronutrients.

CONCLUSIONS

Magnesium deficiency may increase the risk of alcohol-related liver injury and adverse liver outcomes. However, currently, there is insufficient evidence to support magnesium supplementation except for clinically relevant magnesium deficiency. Long-term prospective cohort studies assessing the impact of micronutrients on liver disease progression in patients with alcohol use disorder are lacking and may help determine whether there is a causal role for micronutrient deficiencies in alcohol-related liver injury.

Influences of dietary vitamin D3 on growth, antioxidant capacity, immunity and molting of Chinese mitten crab (Eriocheir sinensis) larvae

This study investigates the effects of vitamin D₃ (VD₃) on growth performance, antioxidant capacity, immunity and molting of larval Chinese mitten crab Eriocheir sinensis. A total of 6,000 larvae (7.52 ± 0.10 mg) were fed with six isonitrogenous and isolipidic experimental diets with different levels of dietary VD₃ (0, 3000, 6000, 9000, 12000 and 36000 IU/kg) respectively for 23 days. The highest survival and molting frequency were found in crabs fed 6000 IU/kg VD₃. Weight gain, specific growth rate, and carapace growth significantly increased in crabs fed 3000 and 6000 IU/kg VD₃ compared to the control. Broken-line analysis of molting frequency, weight gain and specific growth rate against dietary VD₃ levels indicates that the optimal VD₃ requirement for larval crabs is 4825-5918 IU/kg. The highest whole-body VD₃ content occurred in the 12000 IU/kg VD₃ group, and the 25-dihydroxy VD₃ content decreased with the increase of dietary VD₃. The malonaldehyde content was lower than the control. Moreover, the superoxide dismutase activity, glutathione peroxidase and total antioxidant capacity of crab fed 6000 IU/kg VD₃ were significantly higher than in control. Crabs fed 9000 IU/kg showed the highest survival after 120 h of salinity stress, and the relative mRNA expressions indicate vitamin D receptor (VDR) is the important regulatory element in molting and innate immunity. The molting-related gene expressions showed that the response of crab to salinity was self-protective. This study would contribute to a new understanding of the molecular basis underlying molting and innate immunity regulation by vitamin D₃ in E. sinensis.

Kisspeptin/Kiss1r system and angiogenic and immunological mediators at the maternal-fetal interface of domestic cats

The Kisspeptin/Kiss1r system is a key regulator of reproduction by stimulating gonadotrophin-releasing hormone and luteinizing hormone release, and in vitro studies have shown that Kisspeptin can modulate angiogenesis and immune function, factors that are also essential for reproduction However, there are no studies on the expression of Kisspeptin/Kiss1r at the maternal-fetal interface in domestic cats and its relationship with angiogenic and immunological mediators. Thus, our objective was to evaluate the spatiotemporal expression profile of Kisspeptin/Kiss1r and angiogenic and immunological mediators in the uterus and placenta of domestic cats during pregnancy. Uterus and placenta samples were collected from cats in mid pregnancy (N = 6) and late pregnancy (N = 6), in addition to uterus from non-pregnant cats in diestrus (N = 7), to evaluate protein and gene expression of kisspeptin (Kiss1), kisspeptin receptor (Kiss1r), vascular endothelial growth factor (VEGF), tyrosine kinase receptor (Flk-1), placental growth factor (PLGF), interferon gamma (INFγ), migration inhibiting factor (MIF), tumor necrosis factor (TNFα), interleukins (IL6 and IL10) by immunohistochemistry and quantitative polymerase chain reaction. Pregnancy increased the uterine expression of Kiss1 and Kiss1r, especially at the late pregnancy, in addition to upregulating INFy, MIF, Vegf, Il10, and Tnf and downregulating Plgf. Higher placental expression of Kiss1r and Plgf mRNA occurred at the late pregnancy, while the expression of Kiss1, VEGF, Flk-1, INFy, TNFα, Il6, and IL10 was higher in the mid of pregnancy. A positive correlation between Kiss1 and Tnf was observed in the placenta, while Kiss1r had a negative correlation with Infγ, Il6, and Il10. The findings reveal that Kisspeptin/Kiss1r and angiogenic and immunological mediators at the maternal-fetal interface of pregnant cat have a gene correlation and are modulated by the gestational age. These data suggest possible functional links of Kisspeptin in placental angiogenesis and immunology.

Ferrotoxicity and Its Amelioration by Calcitriol in Cultured Renal Cells

Globally, acute kidney injury (AKI) is associated with significant mortality and an enormous economic burden. Whereas iron is essential for metabolically active renal cells, it has the potential to cause renal cytotoxicity by promoting Fenton chemistry-based oxidative stress involving lipid peroxidation. In addition, 1,25-dihydroxyvitamin D3 (calcitriol), the active form of vitamin D, is reported to have an antioxidative role. In this study, we intended to demonstrate the impact of vitamin D on iron-mediated oxidant stress and cytotoxicity of Vero cells exposed to iohexol, a low osmolar iodine-containing contrast media in vitro. Cultured Vero cells were pretreated with 1,25-dihydroxyvitamin D3 dissolved in absolute ethanol (0.05%, 2.0 mM) at a dose of 1 mM for 6 hours. Subsequently, iohexol was added at a concentration of 100 mg iodine per mL and incubated for 3 hours. Total cellular iron content was analysed by a flame atomic absorption spectrophotometer at 372 nm. Lipid peroxidation was determined by TBARS (thiobarbituric acid reactive species) assay. Antioxidants including total thiol content were assessed by Ellman’s method, catalase by colorimetric method, and superoxide dismutase (SOD) by nitroblue tetrazolium assay. The cells were stained with DAPI (4 ${}^{\prime }$ ,6-diamidino-2-phenylindole), and the cytotoxicity was evaluated by viability assay (MTT assay). The results indicated that iohexol exposure caused a significant increase of the total iron content in Vero cells. A concomitant increase of lipid peroxidation and decrease of total thiol protein levels, catalase, and superoxide dismutase activity were observed along with decreased cell viability in comparison with the controls. Furthermore, these changes were significantly reversed when the cells were pretreated with vitamin D prior to incubation with iohexol. Our findings of this in vitro model of iohexol-induced renotoxicity lend further support to the nephrotoxic potential of iron and underpin the possible clinical utility of vitamin D for the treatment and prevention of AKI.

Placental growth factor and Fms related tyrosine kinase-1 are hypomethylated in preeclampsia placentae

Aim: This study aims to examine the DNA methylation (DNAm) and expression patterns of genes associated with placental angiogenesis in preeclampsia. Materials & methods: DNAm and expression were examined in normotensive (n = 100) and preeclampsia (n = 100) women using pyrosequencing and quantitative real-time PCR respectively. Results: Hypomethylation at several CpGs was observed in PlGF and FLT-1 in women with preeclampsia compared to normotensive controls. PlGF expression was lower in women with preeclampsia while FLT-1 expression was comparable. DNAm at various CpGs was negatively correlated with expression in both the genes and were associated with maternal blood pressure and birth outcomes. Conclusion: DNAm and expression of angiogenic factors in placentae are differentially regulated in preeclampsia and influence birth outcomes.

Calcitriol increases frataxin levels and restores mitochondrial function in cell models of Friedreich Ataxia

Friedreich ataxia (FA) is a neurodegenerative disease caused by the deficiency of frataxin, a mitochondrial protein. In primary cultures of dorsal root ganglia neurons, we showed that frataxin depletion resulted in decreased levels of the mitochondrial calcium exchanger NCLX, neurite degeneration and apoptotic cell death. Here, we describe that frataxin-deficient dorsal root ganglia neurons display low levels of ferredoxin 1 (FDX1), a mitochondrial Fe/S cluster-containing protein that interacts with frataxin and, interestingly, is essential for the synthesis of calcitriol, the active form of vitamin D. We provide data that calcitriol supplementation, used at nanomolar concentrations, is able to reverse the molecular and cellular markers altered in DRG neurons. Calcitriol is able to recover both FDX1 and NCLX levels and restores mitochondrial membrane potential indicating an overall mitochondrial function improvement. Accordingly, reduction in apoptotic markers and neurite degeneration was observed and, as a result, cell survival was also recovered. All these beneficial effects would be explained by the finding that calcitriol is able to increase the mature frataxin levels in both, frataxin-deficient DRG neurons and cardiomyocytes; remarkably, this increase also occurs in lymphoblastoid cell lines derived from FA patients. In conclusion, these results provide molecular bases to consider calcitriol for an easy and affordable therapeutic approach for FA patients.

Ferrotoxicity and Its Amelioration by Calcitriol in Cultured Renal Cells

Globally, acute kidney injury (AKI) is associated with significant mortality and an enormous economic burden. Whereas iron is essential for metabolically active renal cells, it has the potential to cause renal cytotoxicity by promoting Fenton chemistry-based oxidative stress involving lipid peroxidation. In addition, 1,25-dihydroxyvitamin D3 (calcitriol), the active form of vitamin D, is reported to have an antioxidative role. In this study, we intended to demonstrate the impact of vitamin D on iron-mediated oxidant stress and cytotoxicity of Vero cells exposed to iohexol, a low osmolar iodine-containing contrast media in vitro. Cultured Vero cells were pretreated with 1,25-dihydroxyvitamin D3 dissolved in absolute ethanol (0.05%, 2.0 mM) at a dose of 1 mM for 6 hours. Subsequently, iohexol was added at a concentration of 100 mg iodine per mL and incubated for 3 hours. Total cellular iron content was analysed by a flame atomic absorption spectrophotometer at 372 nm. Lipid peroxidation was determined by TBARS (thiobarbituric acid reactive species) assay. Antioxidants including total thiol content were assessed by Ellman's method, catalase by colorimetric method, and superoxide dismutase (SOD) by nitroblue tetrazolium assay. The cells were stained with DAPI (4',6-diamidino-2-phenylindole), and the cytotoxicity was evaluated by viability assay (MTT assay). The results indicated that iohexol exposure caused a significant increase of the total iron content in Vero cells. A concomitant increase of lipid peroxidation and decrease of total thiol protein levels, catalase, and superoxide dismutase activity were observed along with decreased cell viability in comparison with the controls. Furthermore, these changes were significantly reversed when the cells were pretreated with vitamin D prior to incubation with iohexol. Our findings of this in vitro model of iohexol-induced renotoxicity lend further support to the nephrotoxic potential of iron and underpin the possible clinical utility of vitamin D for the treatment and prevention of AKI.

Maternal Vitamin D Deficiency Causes Sustained Impairment of Lung Structure and Function and Increases Susceptibility to Hyperoxia-induced Lung Injury in Infant Rats

Vitamin D deficiency (VDD) during pregnancy is associated with increased respiratory morbidities and risk for chronic lung disease after preterm birth. However, the direct effects of maternal VDD on perinatal lung structure and function and whether maternal VDD increases the susceptibility of lung injury due to hyperoxia are uncertain. In the present study, we sought to determine whether maternal VDD is sufficient to impair lung structure and function and whether VDD increases the impact of hyperoxia on the developing rat lung. Four-week-old rats were fed VDD chow and housed in a room shielded from ultraviolet A/B light to achieve 25-hydroxyvitamin D concentrations <10 ng/ml at mating and throughout lactation. Lung structure was assessed at 2 weeks for radial alveolar count, mean linear intercept, pulmonary vessel density, and lung function (lung compliance and resistance). The effects of hyperoxia for 2 weeks after birth were assessed after exposure to fraction of inspired oxygen of 0.95. At 2 weeks, VDD offspring had decreased alveolar and vascular growth and abnormal airway reactivity and lung function. Impaired lung structure and function in VDD offspring were similar to those observed in control rats exposed to postnatal hyperoxia alone. Maternal VDD causes sustained abnormalities of distal lung growth, increases in airway hyperreactivity, and abnormal lung mechanics during infancy. These changes in VDD pups were as severe as those measured after exposure to postnatal hyperoxia alone. We speculate that antenatal disruption of vitamin D signaling increases the risk for late-childhood respiratory disease.

Ferrotoxicity and its amelioration by endogenous vitamin D in experimental acute kidney injury

This work provides in-depth insights on catalytic iron-induced cytotoxicity and the resultant triggering of endogenous vitamin D synthesis in experimental acute kidney injury. Our results reveal significantly elevated levels of catalytic iron culminating in oxidant-mediated renal injury and a concomitant increase in 1,25-dihdyroxyvitamin D3 levels. Also, changes in other iron-related proteins including transferrin, ferritin, and hepcidin were observed both in the serum as well as in their mRNA expression. We consider all these findings vital since no connection between catalytic iron and vitamin D has been established so far. Furthermore, we believe that this work provides new and interesting results, with catalytic iron emerging as an important target in ameliorating renal cellular injury, possibly by timely administration of vitamin D. It also needs to be seen if these observations made in rats could be translated to humans by means of robust clinical trials.

Four weeks of vitamin D supplementation improves nitric oxide-mediated microvascular function in college-aged African Americans

Reduced nitric oxide (NO)-mediated cutaneous vasodilation, secondary to increased oxidative stress, presents in young African American (AA) compared with European American (EA) adults and may be modulated by vitamin D status. We assessed cutaneous microvascular function in 18 young, healthy (21 ± 2 yr; 9 men, 9 women) subjects before (pre, 8 AA, 10 EA) 4 wk of 2,000 IU/day oral vitamin D supplementation and in 13 subjects after (post, 7 AA, 6 EA) 4 wk of 2,000 IU/day oral vitamin D supplementation. Serum vitamin D concentrations [25(OH)D] were measured at each visit. Three intradermal microdialysis fibers placed in the ventral forearm were randomized for treatment with 10 μM Tempol, 100 μM apocynin, or lactated Ringer's solution (control). Local heating (39°C) induced cutaneous vasodilation; red cell flux was measured at each site (laser-Doppler flowmetry), and cutaneous vascular conductance (CVC = flux/MAP) was expressed as a percentage of maximum (28 mM sodium nitroprusside, +43°C) for each phase of local heating. After stable elevated blood flow was attained, 15 mM N^G-nitro-l-arginine methyl ester (l-NAME; NO synthase inhibitor) was perfused at all sites to quantify the NO contribution to cutaneous vasodilation (%NO), calculated as the difference between local heating and l-NAME plateaus. Serum [25(OH)D], the magnitude of the local heating response, and %NO were all lower in AAs versus EAs (P < 0.01). Tempol (P = 0.01), but not apocynin (P ≥ 0.19), improved the local heating response and %NO. Four weeks of supplementation improved serum [25(OH)D], the local heating response, and %NO in AAs (P ≤ 0.04) but not in EAs (P ≥ 0.41). Vitamin D supplementation mitigated endothelial dysfunction, an antecedent to overt cardiovascular disease (CVD), in otherwise healthy, young AA adults.NEW & NOTEWORTHY Endothelial dysfunction, an antecedent to overt cardiovascular disease (CVD), is observed earlier and more frequently in otherwise healthy African Americans (AAs) when compared with other ethnic groups. Vitamin D may modulate endothelial function, and darkened skin pigmentation increases risk of vitamin D deficiency. We show that 4 wk of 2,000 IU/day vitamin D supplementation improves microvascular responses to local heating in AAs. Ensuring adequate vitamin D status may mitigate development of cardiovascular dysfunction in this at-risk population.

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.

Ferrotoxicity and its amelioration by endogenous vitamin D in experimental acute kidney injury

Acute kidney injury causes significant morbidity and mortality. This experimental animal study investigated the simultaneous impact of iron and vitamin D on acute kidney injury induced by iohexol, an iodinated, non-ionic monomeric radiocontrast agent in Wistar rats. Out of 36 healthy male Wistar rats, saline was injected into six control rats (group 1) and iohexol into the remaining 30 experimental rats (groups 2 to 6 comprising six rats each). Biochemical, renal histological changes, and gene expression of iron-regulating proteins and 1 α-hydroxylase were analyzed. Urinary neutrophil gelatinase-associated lipocalin (NGAL), serum creatinine, urine protein, serum and urine catalytic iron, 25-hydroxyvitamin D3, 1,25-dihydroxyvitamin D3, and tissue lipid peroxidation were assayed. Rats injected with iohexol showed elevated urinary NGAL (11.94 ± 6.79 ng/mL), serum creatinine (2.92 ± 0.91 mg/dL), and urinary protein levels (11.03 ± 9.68 mg/mg creatinine) together with histological evidence of tubular injury and iron accumulation. Gene expression of iron-regulating proteins and 1 α-hydroxylase was altered. Serum and urine catalytic iron levels were elevated (0.57 ± 0.17; 48.95 ± 29.13 µmol/L) compared to controls (0.49 ± 0.04; 20.7 ± 2.62 µmol/L, P < 0.001). Urine catalytic iron positively correlated with tissue peroxidation (r = 0.469, CI 0.122 to 0.667, P = 0.004) and urinary NGAL (r = 0.788, CI 0.620 to 0.887, P < 0.001). 25-hydroxyvitamin D3 (61.58 ± 9.60 ng/mL) and 1,25-dihydroxyvitamin D3 (50.44 ± 19.76 pg/mL) levels increased simultaneously. In a multivariate linear regression analysis, serum iron, urine catalytic iron, and tissue lipid peroxidation independently and positively predicted urinary NGAL, an acute kidney injury biomarker. This study highlights the nephrotoxic potential of catalytic iron besides demonstrating a concurrent induction of vitamin D endogenously for possible renoprotection in acute kidney injury.

Impact statement

This work provides in-depth insights on catalytic iron-induced cytotoxicity and the resultant triggering of endogenous vitamin D synthesis in experimental acute kidney injury. Our results reveal significantly elevated levels of catalytic iron culminating in oxidant-mediated renal injury and a concomitant increase in 1,25-dihdyroxyvitamin D3 levels. Also, changes in other iron-related proteins including transferrin, ferritin, and hepcidin were observed both in the serum as well as in their mRNA expression. We consider all these findings vital since no connection between catalytic iron and vitamin D has been established so far. Furthermore, we believe that this work provides new and interesting results, with catalytic iron emerging as an important target in ameliorating renal cellular injury, possibly by timely administration of vitamin D. It also needs to be seen if these observations made in rats could be translated to humans by means of robust clinical trials.

Gut instincts: vitamin D/vitamin D receptor and microbiome in neurodevelopment disorders

The gut microbiome regulates a relationship with the brain known as the gut–microbiota–brain (GMB) axis. This interaction is influenced by immune cells, microbial metabolites and neurotransmitters. Recent findings show gut dysbiosis is prevalent in autism spectrum disorder (ASD) as well as attention deficit hyperactivity disorder (ADHD). There are previously established negative correlations among vitamin D, vitamin D receptor (VDR) levels and severity of ASD as well as ADHD. Both vitamin D and VDR are known to regulate homeostasis in the brain and the intestinal microbiome. This review summarizes the growing relationship between vitamin D/VDR signalling and the GMB axis in ASD and ADHD. We focus on current publications and summarize the progress of GMB in neurodevelopmental disorders, describe effects and mechanisms of vitamin D/VDR in regulating the microbiome and synoptically highlight the potential applications of targeting vitamin D/VDR signalling in neurodevelopment disorders.

Ablation of Vitamin D Signaling Compromises Cerebrovascular Adaptation to Carotid Artery Occlusion in Mice

Vitamin D insufficiency has been associated with increased incidence and severity of cerebrovascular disorders. We analyzed the impact of impaired vitamin D signaling on the anatomical and functional aspects of cerebrovascular adaptation to unilateral carotid artery occlusion (CAO), a common consequence of atherosclerosis and cause of ischemic stroke. Cerebrocortical blood flow (CoBF) showed a significantly increased drop and delayed recovery after CAO in mice carrying a functionally inactive vitamin D receptor (VDR) with the most sustained perfusion deficit in the temporal cortex. To identify the cause(s) for this altered adaptation, the extent of compensatory blood flow increase in the contralateral carotid artery and the morphology of pial collaterals between the anterior and middle cerebral arteries were determined. Whereas VDR deficiency had no significant influence on the contralateral carotid arterial blood flow increase, it was associated with decreased number and increased tortuosity of pial anastomoses resulting in unfavorable changes of the intracranial collateral circulation. These results indicate that VDR deficiency compromises the cerebrovascular adaptation to CAO with the most sustained consequences in the temporal cortex. The dysregulation can be attributed to the altered development and function of pial collateral circulation whereas extracranial vessels may not be impaired.

Gestational vitamin D deficiency impairs fetal lung development through suppressing type II pneumocyte differentiation

Gestational vitamin D deficiency is associated with pulmonary diseases. This study aimed to investigate the effect of gestational vitamin D deficiency on fetal lung development in mice. Absolute and relative weights of fetal lungs were reduced in vitamin D deficient (VDD) group. Incrassate mesenchyme, measured by septal wall thickness, accompanied by lessened saccular space, was shown in VDD group. Numerous immature type II pneumocytes, as determined by PAS staining, were observed in VDD group. Moreover, increased Ki67-positive cells, a marker of cell proliferation, was detected in VDD group. The additional experiments showed that Sftpa, Sftpb, Sftpc and Sftpd, four surfactant genes, were downregulated and pro-surfactant protein B was reduced in VDD group. FoxA1, FoxA2 and TTF-1, three transcription factors that regulate surfactant genes, and VEGF, a key regulator for pulmonary maturation, were downregulated in VDD group. These results suggest that gestational vitamin D deficiency impairs fetal lung development partially through suppressing type II pneumocyte differentiation.

Vitamin-D3 (α-1, 25(OH) 2D3) Protects Retinal Pigment Epithelium From Hyperoxic Insults

Purpose

Oxidative stress affects the retinal pigment epithelium (RPE) leading to development of vascular eye diseases. Cholecalciferol (VIT-D) is a known modulator of oxidative stress and angiogenesis. This in vitro study was carried out to evaluate the protective role of VIT-D on RPE cells incubated under hyperoxic conditions.

Methods

Cadaver primary RPE (PRPE) cells were cultured in hyperoxia (40% O₂) with or without VIT-D (α-1, 25(OH) 2D3). The functional and physiological effects of PRPE cells with VIT-D treatment were analyzed using molecular and biochemical tools.

Results

Vascular signaling modulators, such as vascular endothelial growth factor (VEGF) and Notch, were reduced in hyperoxic conditions but significantly upregulated in the presence of VIT-D. Additionally, PRPE conditioned medium with VIT-D induced the tubulogenesis in primary human umbilical vein endothelial cells (HUVEC) cells. VIT-D supplementation restored phagocytosis and transmembrane potential in PRPE cells cultured under hyperoxia.

Conclusions

VIT-D protects RPE cells and promotes angiogenesis under hyperoxic insult. These findings may give impetus to the potential of VIT-D as a therapeutic agent in hyperoxia induced retinal vascular diseases.

Transcriptional regulation of CYP3A4 by nuclear receptors in human hepatocytes under hypoxia

The human hepatic cytochrome P-450 3A4 (CYP3A4), recognized as a multifunctional enzyme, has a wide range of substrates including commonly used drugs. Previous investigations demonstrated that the expression of CYP3A4 in human hepatocytes could be regulated by some nuclear receptors (NRs) at transcriptional level under diverse situations. The significance of oxygen on CYP3A4-mediated metabolism seems notable while the regulatory mode of CYP3A4 in the particular case still remains elusive. Recently, striking evidence has emerged that both CYP3A4 and its regulator NR could be inhibited by exposure to hypoxia. Therefore, it is of great importance to elucidate whether and how these NRs act in the transcriptional regulation of CYP3A4 in human hepatocytes under hypoxic conditions. In this review, we mainly summarized transcriptional regulation of the pivotal enzyme CYP3A4 by NRs and explored the possible regulatory pathways of CYP3A4 via these major NRs under hypoxia, expecting to provide favorable evidence for further clinical guidance under such pathological situations.

Effects of vitamin D on steroidogenesis, reactive oxygen species production, and enzymatic antioxidant defense in human granulosa cells of normal and polycystic ovaries

Polycystic ovary syndrome (PCOS) is accompanied with many disturbances in hormone synthesis and antioxidant defense. Previous reports have indicated that Vitamin D (vit.D) affects gene expression and have roles in normal follicular development. Therefore, we investigated the effects of vit.D on steroidogenesis, apoptosis, reactive oxygen species (ROS) production, and antioxidant defenses of human normal granulosa cells (N-GCs) and granulosa cells from polycystic ovaries (PCO-GCs). Ovarian GCs were obtained during oocyte retrieval procedure from 120 women with PCOS and from 100 healthy women who referred to Shiraz Fertility Center. The isolated GCs were cultured in the presence or absence of vit.D (100 nM), for 48 h. Concentration of sex steroids was measured by ELISA. Glutathione peroxidase (GPx) and superoxide dismutase (SOD) expression and activities were assessed by q-PCR and photometric methods, respectively. The amount of ROS production was estimated using chemiluminescence and fluorescence methods. Cell viability and apoptosis were detected by Annexin-V/propidium iodide detection kit. Basal estrone and progesterone secretion by N-GCs was significantly higher than that of PCO-GCs. Vit.D significantly increased aromatase and 3β-hydroxysteroid dehydrogenase activity in N-GCs and PCO-GCs. Basal expression and activity of GPx, in PCO-GCs were significantly lower than those of N-GCs. Treatment with vit.D significantly increased genes expression and enzyme activities in both groups. Basal ROS in PCO-GCs was markedly greater than that of N-GCs, which was attenuated by vit.D treatment. Cell apoptosis was directly correlated with ROS levels. We conclude that vit.D improved N-GCs and PCO-GCs functions through affecting steroidogenesis and enzymatic antioxidant defense. Under vit.D treatment, PCO-GCs could act more similar to N-GCs.

Vitamin D Deficiency Aggravates Hepatic Oxidative Stress and Inflammation during Chronic Alcohol-Induced Liver Injury in Mice

Vitamin D deficiency has been reported in alcoholics. This study is aimed at evaluating the effects of vitamin D deficiency on chronic alcohol-induced liver injury in mice. Mice were fed with modified Lieber-DeCarli liquid diets for 6 weeks to establish an animal model of chronic alcohol-induced liver injury. In the VDD+EtOH group, mice were fed with modified diets, in which vitamin D was depleted. Vitamin D deficiency aggravated alcohol-induced liver injury. Furthermore, vitamin D deficiency aggravated hepatocyte apoptosis during alcohol-induced liver injury. Although it has a little effect on hepatic TG content, vitamin D deficiency promoted alcohol-induced hepatic GSH depletion and lipid peroxidation. Further analysis showed that vitamin D deficiency further increased alcohol-induced upregulation of hepatic inducible nitric oxide synthase (inos), two NADPH oxidase subunits p47phox and gp91phox, and heme oxygenase- (HO-) 1. By contrast, vitamin D deficiency attenuated alcohol-induced upregulation of hepatic antioxidant enzyme genes, such as superoxide dismutase (sod) 1 and gshpx. In addition, vitamin D deficiency significantly elevated alcohol-induced upregulation of hepatic proinflammatory cytokines and chemokines. Taken together, these results suggest that vitamin D deficiency aggravates hepatic oxidative stress and inflammation during chronic alcohol-induced liver injury.

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.

Vitamin D and cardiovascular disease in chronic kidney disease

Chronic kidney disease (CKD) is considered an independent risk factor for cardiovascular disease, with increased cardiovascular morbidity and mortality seen even in the early stages of CKD. Several studies have shown a high prevalence of vitamin D deficiency in individuals with CKD. Low vitamin D levels upregulate the renin-angiotensin-aldosterone system (RAAS), cause endothelial dysfunction, and increase inflammation. Epidemiological studies show an association between vitamin D deficiency and risk factors for cardiovascular disease, but a causal relationship has not been established. The high cardiovascular morbidity and mortality associated with CKD in adults requires therapies to decrease this elevated risk. However, results from several meta-analyses and randomized clinical trials in adults have not shown convincing evidence for the use of vitamin D therapy in improving cardiovascular outcomes. Lack of high-quality evidence from randomized clinical trials in children regarding the effectiveness and long-term safety of vitamin D treatment precludes any recommendations on its use to mitigate the cardiovascular burden of CKD.

Effect of vitamin D on apoptotic marker, reactive oxygen species and human sperm parameters during the process of cryopreservation

OBJECTIVES

Sperm cryopreservation plays an undeniable role in assisted reproductive technology. However, this process significantly reduces the motility, viability, morphology and nuclear integrity of sperm. Reasons of these changes were oxidative stress and apoptosis. The aim of this study was to evaluate the influence of vitamin D on the survival and integrity of fertile sperm after cryopreservation.

MATERIALS AND METHODS

Semen sample of 18 males with normal parameters was used. After swimming up, each sample was divided into two parts. 20 µmol vitamin D was added to one part as experimental group and the other part was left untreated as control group. The samples in all groups were frozen for 14 days. Post-thawing, the groups were evaluated for sperm motility, and viability using eosin staining, morphology using the Diff-Quick staining and apoptosis by TUNEL, Annexin-V and caspase-3 activity assay. By using nitrobluetetraxolium test and thiobarbituric acid, the reactive oxygen species (ROS) and lipid peroxidation of sperms were measured, respectively.

RESULTS

In comparison with control groups, motile and viable sperm concentration was substantially higher in treated groups (P-value<0.05); however, morphological analysis did not show any remarkable changes. Also, ROS and lipid peroxidation values were dramatically reduced by vitamin D (P-value<0.05). TUNEL and Annexin assay for apoptosis were considerably lower in treated groups (P-value<0.05), but caspase activity assay revealed no significant difference between groups.

CONCLUSION

The results have shown that the addition of vitamin D to a freezing medium leads to higher quality and function of human sperm.