An effective therapeutic regimen for hepatic fibrosis requires a deep understanding of the pathogenesis mechanism. Hepatic fibrosis is characterized by activated hepatic stellate cells (aHSCs) with an excessive production of extracellular matrix. Although promoted activation of HSCs by M2 macrophages has been demonstrated, the molecular mechanism involved remains ambiguous. Herein, we propose that the vitamin D receptor (VDR) involved in macrophage polarization may regulate the communication between macrophages and HSCs by changing the functions of exosomes. We confirm that activating the VDR can inhibit the effect of M2 macrophages on HSC activation. The exosomes derived from M2 macrophages can promote HSC activation, while stimulating VDR alters the protein profiles and reverses their roles in M2 macrophage exosomes. Smooth muscle cell-associated protein 5 (SMAP-5) was found to be the key effector protein in promoting HSC activation by regulating autophagy flux. Building on these results, we show that a combined treatment of a VDR agonist and a macrophage-targeted exosomal secretion inhibitor achieves an excellent anti-hepatic fibrosis effect. In this study, we aim to elucidate the association between VDR and macrophages in HSC activation. The results contribute to our understanding of the pathogenesis mechanism of hepatic fibrosis, and provide potential therapeutic targets for its treatment.
Humans ; Hepatic Stellate Cells/pathology* ; Receptors, Calcitriol ; Liver Cirrhosis/pathology* ; Macrophages/metabolism*

Vitamin D plays an important role in mineral and bone homeostasis, immune responses, cardiovascular function and keratinocyte proliferation and differentiation. Vitamin D performs most of its functions by binding to vitamin D receptors (VDR), which interact with other intracellular signaling pathways to regulate bone metabolism, inflammation, immunity, cell cycle progression and apoptosis. Autophagy is a basic stress response in yeast, plants and mammals, and plays a critical role in maintaining optimal functional states at the level of cells and organs. Vitamin D/VDR plays an anti-infection role via inducing and regulating autophagy.
Animals ; Autophagy ; Humans ; Inflammation ; Mammals/metabolism* ; Receptors, Calcitriol/metabolism* ; Vitamin D/physiology* ; Vitamins

OBJECTIVE: To identify the miRNAs targeting vitamin D receptor (VDR) gene and their effect on parathyroid hormone (PTH) secretion in secondary hyperparathyroidism. METHODS: Primary parathyroid cells with secondary hyperparathyroidism were isolated by collagenase digestion and cultured. The miRNAs targeting VDR were screened by bioinformatics methods and full transcriptome sequencing, and dual-luciferase reporter assay was used to verify the targeting relationship between VDR and the screened miRNA. The effects of overexpression or inhibition of the candidate miRNA on VDR mRNA and protein expressions and PTH secretion were evaluated using qRT-PCR and Western blotting. The expression levels of the candidate miRNAs and VDR mRNA in clinical specimens of parathyroid tissues were verified by qRT-PCR, and the expression of VDR protein was detected by immunohistochemistry. RESULTS: We successfully isolated primary parathyroid cells. Dual-luciferase reporter assay verified the targeting relationship of hsa-miR-149-5p, hsa-miR-221-5p, hsa-miR-222-3p, hsa-miR-29a-5p, hsa-miR-301a-5p, hsa-miR-873-5p, hsa-miR-93-3p with VDR, and among them, the overexpression of hsa-miR-149-5p and hsa-miR-301a-5p significantly increased PTH secretion in the parathyroid cells. In patients with secondary hyperparathyroidism, hsa-miR-149-5p was highly expressed in the parathyroid tissues (P=0.046), where the expressions of VDR mRNA (P=0.0267) and protein were both decreased. CONCLUSION The two miRNAs, hsa-miR-149-5p and hsa-miR-301a-5p, may promote the secretion of PTH in patients with secondary hyperparathyroidism by down-regulating the expression of VDR gene.
Humans ; Hyperparathyroidism, Secondary/genetics* ; MicroRNAs/metabolism* ; Parathyroid Hormone ; RNA, Messenger ; Receptors, Calcitriol/genetics*

To investigate the expressions of mucosal barrier proteins in colon cell line DLD-1 under hypoxic environment and its mechanism. Methods After DLD-1 cells were treated separately with hypoxia(l% O),vitamin D(100 nmol/L),or vitamin D plus hypoxia for 48 hours,the expressions of vitamin D receptor(VDR),tight junction proteins zonula occludens-1(ZO-1),occludin,Claudin-1,and adherent junction protein(E-cadherin)were determined by Western blot.Stable VDR knock-down(Sh-VDR)DLD-1 cell line and control DLD-1 cell line were established by lentivirus package technology and the protein expressions after hypoxia treatment were detected. Results Compared with control group,the expressions of occludin,Claudin-1,and VDR increased significantly after hypoxia treatment(all <0.001).In addition to the protein expressions of occludin,Claudin-1 and VDR,the expressions of ZO-1 and E-cadherin were also obviously higher in vitamin D plus hypoxia group than in single vitamin D treatment group(all <0.001).After hypoxia treatment,Sh-VDR cell line showed significantly decreased expressions of ZO-1(<0.001),occludin(<0.05),Claudin-1(<0.01)and E-cadherin(<0.001)when compared with untreated Sh-VDR cell line. Conclusion VDR acts as a regulator for the expressions of intestinal mucosal barrier proteins under hypoxia environment in DLD-1 colon cell line,indicating that VDR pathway may be another important protective mechanism for gut barrier in low-oxygen environment.
Antigens, CD ; metabolism ; Cadherins ; metabolism ; Cell Hypoxia ; Cell Line ; Claudin-1 ; metabolism ; Colon ; cytology ; Humans ; Occludin ; metabolism ; Receptors, Calcitriol ; metabolism ; Tight Junctions ; Vitamin D ; pharmacology ; Zonula Occludens-1 Protein ; metabolism

Over the past decade, there has been increasing attention on the interaction between microbiota and bile acid metabolism. Bile acids are not only involved in the metabolism of nutrients, but are also important in signal transduction for the regulation of host physiological activities. Microbial-regulated bile acid metabolism has been proven to affect many diseases, but there have not been many studies of disease regulation by microbial receptor signaling pathways. This review considers findings of recent research on the core roles of farnesoid X receptor (FXR), G protein-coupled bile acid receptor (TGR5), and vitamin D receptor (VDR) signaling pathways in microbial-host interactions in health and disease. Studying the relationship between these pathways can help us understand the pathogenesis of human diseases, and lead to new solutions for their treatments.
Bile Acids and Salts/metabolism* ; Gastrointestinal Microbiome ; Humans ; Inflammation/metabolism* ; Metabolic Syndrome/metabolism* ; Receptors, Calcitriol/physiology* ; Receptors, Cytoplasmic and Nuclear/physiology* ; Receptors, G-Protein-Coupled/physiology* ; Signal Transduction/physiology*

Vitamin D (VD) is essential for bone health, and VD or its analogues are widely used in clinics to ameliorate bone loss. The targets and mode of VD anti-osteoporotic actions appear to be different from those of other classes of drugs modulating bone remodeling. VD exerts its biological activities through the nuclear VD receptor (VDR)-mediated transcriptional regulation of target mRNA and non-coding RNA genes. VD-induced gene regulation involves epigenetic modifications of chromatin conformation at the target loci as well as reconfiguration of higher-order chromosomal organization through VDR-mediated recruitment of various regulatory factors. Enhancer RNAs (eRNA), a class of non-coding enhancer-derived RNAs, have recently emerged as VDR target gene candidates that act through reorganization of chromatin looping to induce enhancer-promoter interaction in activation of mRNA-encoding genes. This review outlines the molecular mechanisms of VD actions mediated by the VDR and suggests novel function of eRNAs in VDR transactivation.
Bone Remodeling ; Chromatin ; Epigenomics ; Metabolism ; Receptors, Calcitriol ; RNA ; RNA, Messenger ; RNA, Untranslated ; Transcriptional Activation ; Vitamin D ; Vitamins

OBJECTIVE: There is asingle nucleotide polymorphism (SNP) in the exon 2 of the vitamin D receptor (VDR) gene that can be distinguished using the restriction endonuclease FokI, and accordingly divided into three genotypes: FF, Ff and ff. VDR-FokI polymorphism was the only known SNP that could alter the protein structure of VDR. CYP24A1 is the gene encoding vitamin D 24 hydroxylase and is a vitamin D responsive gene. The influence of rs2228570 on transcriptional activation by VDR in human gingival fibroblasts (hGF) and periodontal ligament cells (hPDLC) was investigated in this study. METHODS: hGF and hPDLC of 12 donors' were primarily cultured and genomic DNA was extracted. A part of genomic DNA with the length of 267 bp was obtained using PCR, which contained the SNP. VDR-Fok I genotypes were determined according to the results of restriction fragment length polymorphism. hGF and hPDLC were stimulated with 10 nmol/L 1α,25 dihydroxy vitamin D₃ (1,25OH₂D₃) or 1 000 nmol/L 25 hydroxy vitamin D₃ (25OHD₃) for 48 h before RNA was extracted. Then VDR antagonist ZK159222 was used or not used during 1,25OH₂D₃ or 25OHD₃ stimulation with hGF and hPDLC. After 1,25OH₂D₃ stimulation for 48 h, the proteins in hGF and hPDLC were also collected. The protein expressions of CYP24A1 and VDR were detected using Western blot. RESULTS: Among the 12 donors' cell cultures, the number of FF, ff and Ff genotypes was 4, 3 and 5, respectively.After stimulation with 1,25OH₂D₃ or 25OHD₃ for 48 h,CYP24A1 mRNA levels in FF-hGF were significantly higher than those in other hGF genotypes(1,25OH₂D₃: F=31.147, P<0.01; 25OHD₃: F= 32.061,P <0.01), as was in FF-hPDLC (1,25OH₂D₃: F=23.347, P<0.01; 25OHD₃: F=32.569,P<0.01). When ZK159222 was used before 1,25OH₂D₃ stimulation, this statistically significant difference disappeared (hGF: F=0.246, P=0.787; hPDLC: F=0.574, P=0.583). When ZK159222 was used before 25OHD₃ stimulation, the trend was similar (hGF: F=1.636, P=0.248; hPDLC: F=0.582, P=0.578).After stimulation with 1,25OH₂D₃ for 48 h, CYP24A1 protein levels in FF-hGF were significantly higher than those in the other hGF genotypes (F=12.368, P <0.01), as was in FF-hPDLC (F=15.749, P <0.01). In hGF and hPDLC, the mRNA or protein expression of VDR of different genotypes was not significantly different under different stimulation conditions.The paired comparison showed that there was no statistically significant difference between the expression of CYP24A1 in hGF and that in hPDLC under all the stimulation conditions, as was the expression of VDR. CONCLUSION In hGF and hPDLC, the FF-VDR genotype is associated with the more remarkable up-regulation of CYP24A1than the other genotypes, indicating that transcriptional activation of FF-VDR might be higher than those of other vitamin D receptors.
Fibroblasts/metabolism* ; Genotype ; Humans ; Periodontal Ligament/metabolism* ; Polymorphism, Genetic ; Polymorphism, Restriction Fragment Length ; Polymorphism, Single Nucleotide ; Receptors, Calcitriol/genetics* ; Vitamin D3 24-Hydroxylase/metabolism*

OBJECTIVE: Autism spectrum disorder (ASD) is a complex neurodevelopmental syndrome with an increasingly prevalent etiology, yet not fully understood. It has been thought that vitamin D, complex B vitamin levels and homocysteine are associated with environmental factors and are important in ASD. The aim of this study was to examine serum vitamin D, vitamin D receptor (VDR), homocysteine, vitamin B6, vitamin B12 and folate levels in ASD. METHODS: In this study, serum vitamin D and VDR, homocysteine, vitamins B6, B12 and folate levels were determined in 60 patients with ASD (aged 3 to 12 years) and in 45 age-gender matched healthy controls. In addition, calcium, phosphorus and alkaline phosphatase, which are associated with vitamin D metabolism, were measured from serum in both groups. ASD severity was evaluted by the Childhood Autism Rating Scale (CARS). RESULTS: Serum vitamin D and VDR were substantially reduced in patients with ASD in comparision to control group. However, homocysteine level was significantly higher and vitamin B6, vitamin B12 and folate were also reduced in patients with ASD. Total CARS score showed a positive association with homocysteine and a negative correlation with vitamins D, B6, B12, folate and VDR. CONCLUSION: This comprehensive study, which examines many parameters has shown that low serum levels of vitamins D, B6, B12, folate and VDR as well as high homocysteine are important in the etiopathogenesis of ASD. However, further studies are required to define the precise mechanism(s) of these parameters and their contributions to the etiology and treatment of ASD.
Alkaline Phosphatase ; Autism Spectrum Disorder* ; Autistic Disorder* ; Calcium ; Child* ; Folic Acid ; Homocysteine ; Humans ; Metabolism ; Phosphorus ; Receptors, Calcitriol* ; Vitamin B 12 ; Vitamin B 6 ; Vitamin D* ; Vitamins*

Vitamin D is an important secosteroid hormone in skeletal and non-skeletal systems. Vitamin D has relevance to muscle and immune function, hypertension, diabetes mellitus, cancer, and pregnancy because vitamin D receptors (VDR) are present in many non-skeletal tissues. Vitamin D acts on target tissues via the binding of its active form to VDR. As vitamin D affects not only bone metabolism but also glucose metabolism, vitamin D deficiency may affect the development of gestational diabetes mellitus and fetal growth. Although vitamin D deficiency is prevalent during pregnancy, there are conflicting reports on the effect of vitamin D deficiency on pregnancy complications, such as fetal growth restriction and gestational diabetes. This article reviews published papers on the effects of vitamin D on gestational diabetes and fetal growth.
Diabetes Mellitus ; Diabetes, Gestational* ; Female ; Fetal Development ; Glucose ; Hypertension ; Metabolism ; Pregnancy ; Pregnancy Complications ; Receptors, Calcitriol ; Vitamin D Deficiency ; Vitamin D* ; Vitamins*

Objective: To investigate the effect of small interfering RNA silencing the vitamin D receptor (VDR) on the biological behavior of prostate cancer PC-3 cells. METHODS: We constructed the VDR-shRNA lentiviral vector and determined the mRNA and protein expressions of VDR by RT-PCR and Western blot. Using scratch wound healing and Transwell chamber assays, we detected the changes in the migration and invasiveness of the PC-3 cells after silencing VDR. RESULTS: The VDR-shRNA plasmid significantly interfered the VDR expression and successfully screened the cell lines with stable VDR-shRNA interference. The rate of scratch wound healing was markedly lower in the VDR interference group than in the blank control and LV3 negative control groups (59% vs 73.6% and 77.8%, P <0.05), but with no statistically significant difference between the latter two (P >0.05), and so was the count of permeable cells (P <0.05), but with no significant difference between the latter two groups, either (P >0.05). The migration ability and invasiveness of the VDR-treated cells were remarkably decreased as compared with those of the control cells. CONCLUSIONS Down-regulated expression of the VDR gene may reduce the migration and invasiveness of prostate cancer cells.
Cell Line, Tumor ; Cell Movement ; genetics ; Cell Proliferation ; Down-Regulation ; Gene Silencing ; Humans ; Lentivirus ; Male ; Neoplasm Invasiveness ; genetics ; Plasmids ; Prostatic Neoplasms ; genetics ; pathology ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; Receptors, Calcitriol ; genetics ; metabolism ; Transfection ; Wound Healing ; genetics