VitD3 Treatment Research Articles

1,25-D3 ameliorates ischemic brain injury by alleviating endoplasmic reticulum stress and ferroptosis: Involvement of vitamin D receptor and p53 signaling

Endoplasmic reticulum stress (ERS) and ferroptosis are linked to cerebral ischemia reperfusion injury (CIRI). The neuroprotective properties of 1α, 25-dihydroxyvitamin D3 (VitD3 or 1,25-D3) have been well established; however, the mechanism by which VitD3 treats CIRI through ERS and ferroptosis has not been examined. Hence, we developed middle cerebral artery occlusion/reperfusion (MCAO/R) model in SD rats to ascertain if VitD3 preconditioning mediates ERS and ferroptosis involving of p53 signaling. In this study, we observed that VitD3 can reduce infarction volume and cerebral edema, which leads to the improvement of nerve function. HE, Nissl and Tunel staining showed that VitD3 treatment significantly improved the morphology of neuronal cells and reduced their death. The expression and activation of Vitamin D receptor (VDR), PKR-like ER kinase (PERK), C/EBP-homologous protein (CHOP), p53, nuclear factor erythroid 2-related factor 2 (Nrf2), glutathione peroxidase 4 (GPX4) and reactive oxygen species (ROS) in the ischemic penumbral area were detected by real-time qPCR, Western-blotting and Elisa. The results showed that after VitD3 treatment, VDR increased, ERS-related indices (PERK, CHOP) significantly decreased and ferroptosis-related indices (Nrf2, GPX4) increased. As a VDRs antagonist, pyridoxal-5-phosphate (P5P) can partially block the neuroprotective effects of VitD3. Therefore, CIRI can induce ERS and ferroptosis in the ischemic penumbra area and VitD3 may ameliorate nerve damage in CIRI rats by up-regulating VDR, alleviating p53-associated ERS and ferroptosis.

Vitamin D3 attenuates autoimmune thyroiditis by regulating Th17/Treg cell differentiation via YAP/JAK1/STAT1 axis

BackgroundAutoimmune thyroiditis (AITD) is an organ-specific autoimmune disease. Substantial evidence suggests that Vitamin D (VitD) deficiency is closely associated with an increased risk of AITD. However, the effects of VitD3 on immune cells, especially Th17/Treg cell subsets, and the underlying molecular mechanism in AITD have not yet been investigated. MethodsAn experimental autoimmune thyroiditis (EAT) mouse model was established with a high-iodine diet. After 8 weeks, thyroid injury was assessed using hematoxylin and eosin (H&E) staining. ELISA was employed to measure serum levels of thyroxine (T3 and T4), thyroid autoimmune antibodies (Tg-Ab and TPO-Ab), and inflammatory cytokines. Flow cytometry and multiplex fluorescence immunohistochemical (mIHC) assays were used to analyze Th17/Treg cell subsets. The CCK-8 and flow cytometry assays were used to determine cell viability and apoptosis. ResultsAdministration of VitD3 reduced thyroid follicle destruction, decreased lymphocyte infiltration, and lowered T3, T4, Tg-Ab, and TPO-Ab serum levels in EAT mice. VitD3 treatment also reduced the frequency of Th17 cells while promoting the Treg cell subset both in the thyroid tissue and in the splenocytes cultured in vitro. Furthermore, VitD3 administration suppressed the production of inflammatory cytokines in EAT mice. VitD3 was also found to regulate Treg cells' differentiation, viability, and apoptosis. Mechanistically, we discovered that VitD3 treatment upregulated YAP expression and activated the JAK/STAT pathway. Rescue assays confirmed that depletion of YAP counteracted the effects of VitD3 on Treg cell differentiation and function. ConclusionVitamin D3 attenuates AITD by modulating Th17/Treg cell balance via regulating the YAP/JAK1/STAT1 axis.

Vitamin D regulates COVID-19 associated severity by suppressing the NLRP3 inflammasome pathway.

The role of vitamin D3 (VitD3) in modulating innate and adaptive immunity has been reported in different disease contexts. Since the start of the coronavirus disease-2019 (COVID-19) pandemic, the role of VitD3 has been highlighted in many correlational and observational studies. However, the exact mechanisms of action are not well identified. One of the mechanisms via which VitD3 modulates innate immunity is by regulating the NLRP3-inflammasome pathway, being a main underlying cause of SARS-CoV-2-induced hyperinflammation. Blood specimens of severe COVID-19 patients with or without VitD3 treatment were collected during their stay in the intensive care unit and patients were followed up for 29 days. qPCR, western blot, and ELISA were done to investigate the mechanism of action of VitD3 on the NLRP3 inflammasome activation. We here report the ability of VitD3 to downregulate the NLRP3-inflammsome pathway in severe COVID-19 patients. Lower inflammasome pathway activation was observed with significantly lower gene and protein expression of NLRP3, cleaved caspase-1, ASC and IL-1β among severe COVID-19 patients treated with VitD3. The reduction of the inflammasome pathway was associated with a reduction in disease severity markers and enhancement of type I IFN pathway. Our data reveals an important anti-inflammatory effect of VitD3 during SARS-CoV-2 infection. Further investigations are warranted to better characterize the ability of VitD3 to control disease pathogenesis and prevent progression to severe states. This will allow for a more efficient use of a low cost and accessible treatment like VitD3.

Vitamin D3 mitigates type 2 diabetes induced by a high carbohydrate-high fat diet in rats: Role of the purinergic system

This study evaluated the effect of vitamin D3 (VIT D3) supplementation on the enzymatic activities and density of ectonucleoside triphosphate diphosphohydrolase (E-NTPDase), ecto-5-nucleotidase (E-5′-NT), adenosine deaminase (ADA), as well as the density of P2 × 7R, P2Y12R, A1R, A2AR receptors, IL-1β, and oxidative parameters in type 2 diabetic rats. Forty male Wistar rats were fed a high carbohydrate-high fat diet (HCHFD) and received an intraperitoneal injection containing a single dose of streptozotocin (STZ, 35 mg/kg). Animals were divided into four groups: 1) control; 2) control/VIT D3 12 µg/kg; 3) diabetic; and 4) diabetic/VIT D3 12 µg/kg. Results show that VIT D3 reduced blood glucose, ATP hydrolysis, ADA activity, P2Y12R density (platelets), as well as ATP, ADP, and AMP hydrolysis and ADA activity (synaptosomes). Moreover, VIT D3 increased insulin levels and AMP hydrolysis (platelets) and improved antioxidant defense. Therefore, we suggest that VIT D3 treatment modulates hyperglycemia-induced changes via purinergic enzymes and receptor expression, consequently attenuating insulin homeostasis dysregulation in the diabetic state.

Abstract 14841: Higher Than Daily RDA Recommended Vitamin D 3 Dosing and Multiple Titrations Are Required to Achieve >40 ng/mL 25-hydroxy Vitamin D Levels in Acute Coronary Syndrome (ACS) Participants Enrolled and Randomized to Targeted Vitamin D Treatment: The Target D Trial

Background: Low vitamin (vit) D serum levels in observational data are associated with increased cardiovascular (CV) events. Prevalence of vit D deficiency (≤20 ng/mL) in the USA is estimated at 40%. Meanwhile, doses for USA recommended dietary allowance (RDA) are 600-800 IU. Several randomized trials of vit D therapy did not use serum levels to target dosing, rather utilized doses from 2000 to 4000 IU daily. The Target-D trial utilizes an achieved vit D serum (>40 ng/mL) strategy. We provide an initial overview of dosing and titration to achieve vit D serum levels >40 ng/mL. Methods: Target-D (NCT: 02996721), a randomized event-driven trial, enrolled (April 2017-May 2023) a total of 632 (316/arm) acute coronary syndrome (ACS) patients to targeted vit D 3 treatment or standard of care. Vit D 3 supplementation was based on a dosing algorithm (Table 1). For baseline serum vit D >40, no supplementation is given, and participants return at 12-months for reassessment. Those with a baseline serum vit D ≤40, the algorithm is applied, and participants return in 3-month intervals for assessment and dosing adjustment, until levels are >40 ng/mL. Results: Of the 316 (62.8±11.3 yrs, 23.1% female, 90% white) treatment participants, 89.4% (n=279) required vit D 3 dosing. Mean serum vit D was 25.9±11.5 ng/mL (median: 24, range: 5-84). Table 2 shows the percent of participants achieving >40 ng/mL at each interval by dose. Only 13.5% of participants were able to achieve >40 ng/mL using < 2000 IU, 20.8% needed 3000-4000 IU, 51% needed 5000-8000 IU, and 14.6% required > 10,000 IU. Conclusions: At our center, ACS patients have low serum vit D levels. Participants randomized to vit D 3 required doses well above US daily RDA, with 86.5% requiring >2,000 daily and 14.6% requiring > 10,000 IU. Less than 65% achieved >40 at 3 months, another 25% required 6 months. Contemporary vit D studies may have underdosed study participants, potentially achieving treatment serum levels less than “therapeutic”.

Evaluation of serum anti-Müllerian hormone concentrations following treatment with vitamin D in Holstein Friesian heifers.

Anti-Müllerian hormone (AMH) levels in the blood of dairy cattle are associated with the count of antral follicles (AFC), ovarian function. Numerous studies, particularly in human medicine, have shown that vitamin D3 (Vit D3) has a positive effect on AMH levels. To our knowledge, the effects of Vit D3 on serum AMH levels in heifers have not been investigated. The goal of the current study was to evaluate the concentrations of serum AMH in dairy heifers following Vit D3 treatment. The study included 20 healthy non-pregnant Holstein Friesian heifers. These animals came to estrus at least once. All heifers received a single intramuscular dosage of 5 million IU Vit D3 (Cholecalciferol). Blood samples were collected from the coccygeal veins of all animals before and after Vit D3 injection (days 7, 14, and 28) for the measurement of AMH and 25(OH)D concentrations. In our analysis, we observed that after exogenous Vit D3 administration, circular 25(OH)D increased constantly (up to day 28 after Vit D3 injection) in all animals. On day 28, AMH concentrations saw a 10% increase in comparison with those measured the day before the Vit D3 injection. However, a comparison of AMH concentrations measured across days did not reveal statistically significant differences between Day 0, 7, 14, and 28 levels (p = .10). Furthermore, no statistical correlation was observed between the pairs (age-AMH) and (weight-AMH). Considering all times, no correlation was found between 25(OH)D and blood AMH levels. These findings demonstrated that exogenous Vit D3 did not affect serum AMH in Holstein Friesian heifers.

A comparative absorption study of sucrosomial® orodispersible vitamin D3 supplementation vs. a reference chewable tablet and soft gel capsule vitamin D3 in improving circulatory 25(OH)D levels in healthy adults with vitamin D deficiency-Results from a prospective randomized clinical trial.

Vitamin D (Vit D) deficiency (VDD), associated with diverse health conditions, is commonly treated with Vit D3 supplements. However, the gastrointestinal (GI) absorption of Vit D3 in different formulations has not been well studied. We aimed to compare the absorption of an innovative phospholipids-sucrester matrix biodelivery vehicle-based (sucrosomial®) orodispersible Vit D3 preparation against a reference chewable tablet and soft gel capsule (SGC) Vit D3 formulations in Vit D-deficient healthy adults. In study 1, 25 subjects were randomized to receive a weekly single dose of 200,000 IU of sucrosomial® Vit D3 (n = 12) or chewable tablet Vit D3 (n = 13) for 3 weeks. In study 2, 20 subjects were randomized to receive a single dose of 200,000 IU every other week of sucrosomial® Vit D3 (n = 10) or SGC Vit D3 (n = 10) for 6 weeks. Circulatory 25-hydroxyvitamin D3 [25(OH)D] levels were reassessed after 2, 3, and 6 weeks in study 1 and after 4 and 6 weeks in study 2. In study 1, after 2 weeks, circulatory 25(OH)D levels increased significantly in both Vit D3 treatment groups (p < 0.0001) but improved markedly in the sucrosomial® Vit D3 group, with no further considerable change after 3 and 6 weeks in both groups. Overall, at all three follow-ups, sucrosomial® Vit D3 treatment achieved significantly higher and sustained 25(OH)D levels (p < 0.001). In study 2, after 4 weeks, both Vit D3 treatment groups showed significant improvement in circulatory 25(OH)D levels (p < 0.0001) but substantially higher in the sucrosomial® group with statistically significant differences between the two treatment groups (p = 0.02). At the 6-week follow-up, only subjects in the sucrosomial® Vit D3 group showed a further increase in circulatory 25(OH)D levels (p = 0.049), but no further significant changes in the levels of the SGC Vit D3 group (p = 0.062), showing a statistically significant difference between the two treatment groups (p = 0.002). The Vit D3 treatment was well tolerated by all participants, and no treatment-emergent effects or serious adverse events were reported. Our results suggest that the sucrosomial® Vit D3 preparation absorbs efficiently in the GI system, achieving adequately higher and sustained circulatory Vit D levels in VDD, and thus can effectively contribute to the body protection against VDD-associated health conditions. clinicaltrials.gov, identifier: NCT05706259.

1α,25-Dihydroxyvitamin D3 Improves Follicular Development and Steroid Hormone Biosynthesis by Regulating Vitamin D Receptor in the Layers Model

1α,25-Dihydroxyvitamin D3 (VitD3) is the active form of vitamin D, and it regulates gene expression and protein synthesis in mammalian follicle development. However, the function of VitD3 in the follicular development of layers remains unclear. This study investigated, through in vivo and in vitro experiments, the effects of VitD3 on follicle development and steroid hormone biosynthesis in young layers. In vivo, ninety 18-week-old Hy-Line Brown laying hens were randomly divided into three groups for different treatments of VitD3 (0, 10, and 100 μg/kg). VitD3 supplementation promoted follicle development, increasing the number of small yellow follicles (SYFs) and large yellow follicles (LYFs) and the thickness of the granulosa layer (GL) of SYFs. Transcriptome analysis revealed that VitD3 supplementation altered gene expression in the ovarian steroidogenesis, cholesterol metabolism, and glycerolipid metabolism signaling pathways. Steroid hormone-targeted metabolomics profiling identified 20 steroid hormones altered by VitD3 treatment, with 5 being significantly different among the groups. In vitro, it was found that VitD3 increased cell proliferation, promoted cell-cycle progression, regulated the expression of cell-cycle-related genes, and inhibited the apoptosis of granulosa cells from pre-hierarchical follicles (phGCs) and theca cells from prehierarchical follicles (phTCs). In addition, the steroid hormone biosynthesis-related genes, estradiol (E2) and progesterone (P4) concentrations, and vitamin D receptor (VDR) expression level was significantly altered by VitD3. Our findings identified that VitD3 altered the gene expression related to steroid metabolism and the production of testosterone, estradiol, and progesterone in the pre-hierarchical follicles (PHFs), resulting in positive effects on poultry follicular development.

Elevated Pro-inflammatory Cytokine Levels in Acute Reflux Esophagitis Are Reduced by 1,25 Dihydroxy Vitamin D3.

Gastric acid reflux into the esophagus can cause irritation and inflammation of the esophagus and progress to reflux esophagitis (RE). Vitamin D3 (VitD3) has anti-inflammatory effects and plays an important regulatory role in adaptive and innate immunity. We hypothesized that VitD3 may play a protective role in RE. Seventy male Sprague-Dawley rats were used, and acute RE (n=35) or chronic RE (n=35) were surgically induced. The effects of different doses of VitD3 on morphological changes and alteration of pro-inflammatory cytokine levels were examined in the rat models. Western blot analysis was performed to determine protein expression levels of IL-1β, IL-6, and IL-8 in esophageal tissues. Serum levels of VitD3 and calcium were determined using enzyme-linked immunosorbent assays. The protein expression of pro-inflammatory cytokines IL-1β, IL-6, and IL-8 was found significantly increased in RE. VitD3 treatment significantly reduced the levels of these pro-inflammatory cytokines in both the low-dose and high-dose VitD3 groups compared to control groups in acute RE, but not chronic RE. Macrographic and histopathological examination revealed various degrees of esophageal impairment in rats following surgical induction of acute or chronic RE in rats. These impairments were not improved by VitD3. Morphological grading of esophageal mucosa showed no significant differences between acute and chronic RE. Elevated serum levels of calcium were observed after VitD3 treatment. IL-1β, IL-6, and IL-8 levels were significantly elevated in RE. The abnormal increase in these important pro-inflammatory cytokines was suppressed by VitD3 in the rat models of acute RE. These novel findings suggest a potential protective role of VitD3 in early-stage RE.

Vitamin D3 eradicates Helicobacter pylori by inducing VDR-CAMP signaling.

Vitamin D3 [VitD3, 1,25 (OH)2D3] is known to have immunomodulatory and anti-microbial properties; however, its activity against Helicobacter pylori is unclear. In this study, we established H. pylori infection models in wild-type and VitD3 receptor (VDR) knockdown mice and analyzed the effects of VitD3 and their underlying mechanisms. VDR+/+ and VDR+/- mice were intragastrically infected with the H. pylori SS1 strain. After confirmation of H. pylori infection, mice were treated with different doses of VitD3. The infection levels in stomach tissues were quantified using the colony-forming assay, and the expression levels of the VDR and cathelicidin antimicrobial peptide (CAMP) in the gastric mucosa were analyzed by immunohistochemistry and western blotting. The gastric mucosa of VDR+/- mice was more susceptible to H. pylori colonization and had lower levels of VDR and CAMP expression than that of VDR+/+ mice. H. pylori infection upregulated VDR and CAMP expression in the stomach of both wild-type and mutant mice, and VitD3 treatment resulted in further increase of VDR and CAMP levels, while significantly and dose-dependently decreasing the H. pylori colonization rate in both mouse groups, without affecting blood calcium or phosphorus levels. Our data indicate that oral administration of VitD3 reduces the H. pylori colonization rate and upregulates VDR and CAMP expression in the gastric mucosa, suggesting a role for VitD3/VDR/CAMP signaling in the eradication of H. pylori in the stomach. These findings provide important insights into the mechanism underlying the anti-H. pylori activity of VitD3 and should be useful in the development of measures to eradicate H. pylori.

Synergistic Anti-Cancer Activity of the Combination of 1,25-Dihydroxyvitamin D3 and Retinoic Acid in U937 Cell Line.

MicroRNA is a form of non-coding RNAs that able to regulate gene expression. miR-424 is one of the members of the regulatory family, which plays an important role in the proliferation and differentiation of myeloid cells. Epigenetic changes can change the level of miR-424 under environmental factors. Therefore, the level of expression of miR-424 in U937 cells of the myeloid line was evaluated in this research under the influence of vitamin D3 (VitD3) and retinoic acid (RA). In this study, U937 cells were cultured in the presence of VitD3, and RA to evaluate cell proliferation, viability via the trypan blue exclusion test, and expression level of miR-424 by real-time PCR at specific times. Cell proliferation has shown a significant decrease in the RA group versus other groups during incubation times (P < 0.05). In VitD3 group, there was a significant increase in cell proliferation after 24- and 48-hours incubation periods versus other groups. In the VitD3 and RA groups, the increase of cell proliferation caused the downregulation of miR-424. In addition, the upregulation of VitD3 group and downregulation of the RA group were significant versus the control group (P < 0.05). We concluded that the expression level of miR-424 was critically affected in the dose- and time-dependent of RA and VitD3 treatment in the U937 cell line. Treatment with VitD3 decreased the expression of miR-424 and RA treatment increase miR-424 expression level in physiological doses.

Immunopharmacological Properties of VitD3: 1, 25VitD3 Modulates Regulatory T Cells and Th17 Cells and the Cytokine Balance in PBMCs from Women with Unexplained Recurrent Spontaneous Abortion (URSA).

VitD3 may contribute to a successful pregnancy through modulation of immune responses. Therefore, VitD3 deficiency may have a role in the immunopathogenesis of unexplained recurrent spontaneous abortion (URSA). However, the mechanisms of immunomodulatory actions of VitD3 in decreasing the risk of recurrent spontaneous abortion have not been understood well. The purpose of this research was to investigate the influence of 1,25VitD3 on regulatory T cells /Th17 axis, the gene expressions and concentrations of related cytokines including, TGF-β, IL-10, IL-6, IL-23, and IL-17A in peripheral blood mononuclear cells (PBMCs) of healthy women as a control group and women with URSA. Isolation of PBMCs was performed from peripheral blood of the subjects of the studied groups (20 women with URSA as a case group, and 20 control women). The effects of 1,25VitD3 (50 nM, for 24 hours) on the studied parameters were evaluated and were compared to the positive and negative controls in vitro. Flow cytometry analysis was used to determine the percentages of regulatory T cells and Th17 cells. For gene expression measurement and cytokines assay, Realtime PCR and ELISA were carried out. The proportion of regulatory T cells was markedly lower, while the proportion of Th17 cells in women with URSA was considerably higher than in the control group (P=0.01, P=0.01). The ratio of the frequency of Tregs to the baseline (1,25VitD3/Untreated) increased, while the ratio of the frequency of Th17 cells to the baseline decreased in women with URSA relative to the controls (P= 0.01, P=0.04). 1,25VitD3 increased IL-10 expressions at both the protein and mRNA levels in PBMCs in women with URSA relative to the control group (P=0.0001, P=0.04). TGF-β levels in the cultured supernatants decreased significantly in the case group in the presence of 1,25Vit- D3 relative to the controls (P=0.03). 1,25VitD3 treatment also significantly decreased gene expressions of IL-6, IL-17A, and IL-23 in PBMCs of women with URSA (P=0.01, P=0.001, P=0.0005), as well as the levels of those cytokines in cell culture supernatants (P=0.03, P=0.02, P=0.01, respectively) in women with URSA relative to the controls. According to the findings of this research, modulation of immune responses by 1,25VitD3 is accomplished by strengthening Tregs function and inhibiting inflammatory responses of Th17 cells, which may have a positive impact on pregnancy outcome. Thus, as an immunomodulating agent, VitD3 may be effective in reducing the risk of URSA.

Evaluation of the effects of 1,25VitD3 on Th17 cells and Tregs in HTLV-1 infected cell lines

Human T-lymphotropic virus type 1 (HTLV-1) causes chronic infections of human T lymphocytes. The present study aimed to evaluate the effects of 1,25VitD3 on the proportion of Tregs and Th17 cells, the expression of related transcription factors (ROR-γt and FOXP3) and cytokines (IL-10, TGF-β, IL-6, and IL-17 A) in the HTLV-1infected cell lines MT-2 and MT-4. MT-2 and MT-4 cells and control PBMCs were treated with 1,25VitD3 and percentages of Tregs and Th17 cells was determined by flow cytometry. Gene expression and cytokine levels were analyzed by real-time PCR and ELISA, respectively. Treatment with-1,25VitD3 increased the percentage of Tregs in MT-2 and MT-4 cells, while it decreased the percentage of Th17 cells among MT-2 cells. 1,25VitD3 treatment also significantly improved FOXP3 gene expression in MT-2 cells, while reducing ROR-γt-gene expression in MT-2 and MT-4 cells comparing to untreated cells. Treatment with 1,25VitD3 significantly improved IL-10 levels in MT-2 cells, as well as TGF-β levels in both cell lines culture supernatants. 1,25VitD3 treatment diminished IL-6 levels in cell culture supernatants of MT-2 and MT-4 as well as IL-17 A levels in MT-2. Here we showed, that 1,25VitD3 modulated immune responses by enhancing Tregs differentiation and functions as well as inhibiting Th17 differentiation and actions in HTLV-1 infected cell lines. This suggests that VitD3 may have therapeutic effects in HTLV-1-related diseases by suppressing adverse inflammatory responses. Keywords: Tregs; Th17 cells; HTLV-1; 1, 25VitD3.

Evaluation of the Effects of 1,25VitD3 on Inflammatory Responses and IL-25 Expression.

VitD3 may contribute to a successful pregnancy through modulation of immune responses, so VitD3 deficiency may have a role in the immunopathogenesis of unexplained recurrent spontaneous abortion (URSA). However, the mechanisms of immunomodulatory actions of VitD3 in decreasing the risk of recurrent spontaneous abortion have not been understood well. Objective: The purpose of this research was to investigate the influence of 1,25VitD3 on IL-25 and related cytokines of Th17 cells including IL-17A, IL-6, and IL-23 in peripheral blood mononuclear cells of healthy women as a control group and women with unexplained recurrent spontaneous abortion. Method: Isolation of peripheral blood mononuclear cells (PBMCs) was performed from peripheral blood of the subjects of the studied groups (20 women with URSA as a case group, and 20 control women). The effects of 1,25VitD3 (50 nM, for 24 h) on the studied parameters were evaluated and were compared to the positive and negative controls in vitro. Flow cytometry analysis was used to determine the percentages of regulatory T cells and Th17 cells. For gene expression measurement and cytokines assay, real-time PCR and ELISA were carried out. Results: The proportion of Th17 cells in women with URSA was considerably higher than in the control group. IL-25 mRNA and protein levels in cultured PBMCs from women with URSA were lower than the controls. 1,25VitD3 increased IL-25 expressions at both the protein and mRNA levels in PBMCs from women with URSA relative to the control group. Additionally, 1,25VitD3 treatment not only significantly decreased the percentage of Th17 cells frequency but also reduced expressions of IL-6, IL-17A, and IL-23 in PBMCs from women with URSA. Conclusion: 1,25VitD3 may diminish inflammatory responses cells via downregulation of IL-25 expression. It could be an interesting subject for future researches in the field of the immunopathology of URSA to identify molecular pathways in URSA treatment.

Regulation of innate immune responses in macrophages differentiated in the presence of vitamin D and infected with dengue virus 2.

A dysregulated or exacerbated inflammatory response is thought to be the key driver of the pathogenesis of severe disease caused by the mosquito-borne dengue virus (DENV). Compounds that restrict virus replication and modulate the inflammatory response could thus serve as promising therapeutics mitigating the disease pathogenesis. We and others have previously shown that macrophages, which are important cellular targets for DENV replication, differentiated in the presence of bioactive vitamin D (VitD3) are less permissive to viral replication, and produce lower levels of pro-inflammatory cytokines. Therefore, we here evaluated the extent and kinetics of innate immune responses of DENV-2 infected monocytes differentiated into macrophages in the presence (D3-MDMs) or absence of VitD3 (MDMs). We found that D3-MDMs expressed lower levels of RIG I, Toll-like receptor (TLR)3, and TLR7, as well as higher levels of SOCS-1 in response to DENV-2 infection. D3-MDMs produced lower levels of reactive oxygen species, related to a lower expression of TLR9. Moreover, although VitD3 treatment did not modulate either the expression of IFN-α or IFN-β, higher expression of protein kinase R (PKR) and 2'-5'-oligoadenylate synthetase 1 (OAS1) mRNA were found in D3-MDMs. Importantly, the observed effects were independent of reduced infection, highlighting the intrinsic differences between D3-MDMs and MDMs. Taken together, our results suggest that differentiation of MDMs in the presence of VitD3 modulates innate immunity in responses to DENV-2 infection.

Vitamin D3 attenuates oxidative stress and regulates glucose level and leukocyte count in a semi-chronic streptozotocin-induced diabetes model.

Vitamin D3 (vit-D3) is a potent immunomodulator with anti-inflammatory and antioxidative properties. We used streptozotocin (STZ)-induced rat model of diabetes (DM) to evaluate the effects of vit-D3. We measured serum biochemical parameters, interleukin-17 (IL-17), osteocalcin (OC), malondialdehyde (MDA), and immune cell count on the 21st day of experiment. A total of 24 Wistar rats were randomly divided into three groups. Each group had eight rats. During the 1st day of the experiment, the control group was injected intraperitoneally with citrate buffer, while STZ group and STZ + vit-D3 group were injected by a single i.p. dose (35mg/kg) of STZ dissolved in citrate buffer (pH 4,5; 0,1M). Vitamin D3 was applied via oral gavage once daily to the STZ + vit-D3 group for a total period of 14days, starting from the 7th day of the experiment. STZ rats showed a significant reduction in OC and an increase in MDA and IL-17 serum concentrations compared to the control rats. We also observed a significant STZ-associated decrease in the number of lymphocytes and a significant increase in monocyte and eosinophil number. Oral treatment with vit-D3 to STZ-induced diabetic rats significantly increased OC and decreased MDA serum levels. Furthermore, vit-D3 treatment resulted in a good regulation of hematopoiesis such as increase in the number of segmented granulocytes and lymphocytes and a reduction in the number of monocytes and eosinophils. Vit-D3 treatment has important therapeutic effects; among many others it can attenuate oxidative stress and ameliorate the hyperglycemic state in the STZ-induced rat diabetic model, which is promising for further clinical trials.

Vitamin D3 induces mesenchymal-to-endothelial transition and promotes a proangiogenic niche through IGF-1 signaling

SummaryAlthough vitamin D3 (VitD3) prevents angiogenesis in cancer, VitD3 deficiency is associated with greater incidence of cardiovascular events in patients. We examined the influence of VitD3 on the angiogenic potential of mesenchymal stem cells (MSCs). VitD3 treatment increased the expression of proangiogenic molecules in MSCs, which exhibited an endothelial cell-like phenotype and promoted vascularization in vitro and in vivo. VitD3 activated the IGF-1 promoter and boosted IGF-1 receptor (IGF-1R) signaling, which was essential for the mesenchymal-to-endothelial transition (MEndoT) of MSCs. VitD3-treated MSCs created a proangiogenic microenvironment for co-cultured arterial endothelial cells, as well as aortic rings. The induction of MEndoT and angiogenesis promotion by VitD3-stimulated MSCs was attenuated by IGF-1R inhibitor picropodophyllin. We conclude that VitD3 promotes MEndoT in MSCs, and VitD3-treated MSCs augment vascularization by producing a proangiogenic niche through continued IGF-1 secretion. These results suggest a potential therapeutic role of VitD3 toward enhancing MSC-induced angiogenesis.

Effects of aspirin, vitamin D3, and progesterone on pregnancy outcomes in an autoimmune recurrent spontaneous abortion model.

High proportions of placental lymphocytes expressing DX5+/CD25+/FOXP3+/CD45+/CD4+ are beneficial to maintain immune tolerance and improve pregnancy outcomes. This study aimed to compare and evaluate the therapeutic effects of aspirin, vitamin D3 (VitD3), and progesterone on the autoimmune recurrent spontaneous abortion (RSA) model. The autoimmune RSA mouse model was constructed, and the embryo loss rate was calculated for each group. Then, primary mouse placental lymphocytes were isolated, and the expression of DX5+/CD25+/FOXP3+/CD45+/CD4+ was detected through flow cytometry. The serum levels of anti-cardiolipin antibody (ACA), β2-GP1, CXCL6, IFN-γ, and IL-6 were measured by ELISA to evaluate the proportion of Th1 and Th2 cells. Autoimmune RSA significantly increased the embryo loss rate, which was improved by aspirin, VitD3, and progesterone treatment, and progesterone treatment had the best effect among the three treatments. The positive expression of DX5+/CD25+/FOXP3+/CD45+/CD4+ in the VitD3 and progesterone groups was significantly higher than that in the autoimmune RSA group, and the expression was highest in the progesterone treatment group. In the plasma of autoimmune RSA mice, the ACA, β2-GP1, CXCL6, and IFN-γ levels were significantly higher and the IL-6 level was lower than the levels in control mice. All these changes could be reversed by aspirin and progesterone treatment. In conclusion, aspirin, VitD3 and progesterone treatment improved pregnancy outcomes in autoimmune RSA mice by regulating the Th1/Th2 balance and cytokines, and progesterone had the best effect of the three treatments.

Vitamin D Attenuates Ischemia/Reperfusion-Induced Cardiac Injury by Reducing Mitochondrial Fission and Mitophagy.

Myocardial infarction is the leading cause of morbidity and mortality worldwide. Although myocardial reperfusion after ischemia (I/R) is an effective method to save ischemic myocardium, it can cause adverse reactions, including increased oxidative stress and cardiomyocyte apoptosis. Mitochondrial fission and mitophagy are essential factors for mitochondrial quality control, but whether they play key roles in cardiac I/R injury remains unknown. New pharmacological or molecular interventions to alleviate reperfusion injury are currently considered desirable therapies. Vitamin D3 (Vit D3) regulates cardiovascular function, but its physiological role in I/R-exposed hearts, especially its effects on mitochondrial homeostasis, remains unclear. An in vitro hypoxia/reoxygenation (H/R) model was established in H9c2 cells to simulate myocardial I/R injury. H/R treatment significantly reduced H9c2 cell viability, increased apoptosis, and activated caspase 3. In addition, H/R treatment increased mitochondrial fission, as manifested by increased expression of phosphorylated dynein-related protein 1 (p-Drp1) and mitochondrial fission factor (Mff) as well as increased mitochondrial translocation of Drp1. Treatment with the mitochondrial reactive oxygen species scavenger MitoTEMPO increased cell viability and decreased mitochondrial fission. H/R conditions elicited excessive mitophagy, as indicated by increased expression of BCL2-interacting protein 3 (BNIP3) and light chain (LC3BII/I) and increased formation of autolysosomes. In contrast, Vit D3 reversed these effects. In a mouse model of I/R, apoptosis, mitochondrial fission, and mitophagy were induced. Vit D3 treatment mitigated apoptosis, mitochondrial fission, mitophagy, and myocardial ultrastructural abnormalities. The results indicate that Vit D3 exerts cardioprotective effects against I/R cardiac injury by protecting mitochondrial structural and functional integrity and reducing mitophagy.

Vitamin D3/vitamin D receptor signaling mitigates symptoms of post-stroke depression in mice by upregulating hippocampal BDNF expression

Elucidation of the pathogenic mechanisms underlying post-stroke depression (PSD) could aid in the development of effective treatments. The present study explored whether Vitamin D3 (VitD3) can function as an antidepressant in PSD model mice and whether the effect is mediated by upregulation of brain-derived neurotrophic factor (BDNF). Mice were subjected to middle cerebral artery occlusion (MCAO) combined with chronic unpredicted mild stress (CUMS) to established the PSD model. For the mice in each group, Longa and Berderson behavioral tests were performed to evaluate motor function, sucrose preference and forced swimming tests were conducted to assess the cardinal depression-like behaviors anhedonia and helplessness, and western blot and immunohistochemistry were conducted to measure the levels of vitamin D receptor (VDR) and BDNF expression levels in mouse hippocampus. Compared to MCAO alone, subsequent CUMS aggravated motor dysfunction and depression-like behaviors, whereas injection of calcitriol (VitD3) enhanced expression levels of VDR and BDNF in the hippocampus as well as ameliorated both motor dysfunction and depression-like behaviors of PSD model mice, with optimal efficacy at 25 μg/kg. Injection of a BDNF-binding protein (TrkB-IgG) almost completely reversed the antidepressant and neuroprotective effects of VitD3, strongly suggesting that VitD3 improved motor dysfunction and depression-like behaviors in PSD model mice by promoting hippocampal BDNF signaling. Modulation of hippocampal BDNF by VitD3 treatment could be an effective strategy for prevention and treatment of PSD.