Vitamin D improves autoimmune diseases by inhibiting Wnt signaling pathway.

OBJECTIVE: In this study, we investigated the development of the Wnt signaling pathway in vitamin D (VitD) to improve systemic lupus erythematosus in mice to breakthrough clinical treatment approaches. METHODS: Body weight changes were recorded during rearing. Antinuclear antibodies (ANA), anti-dsDNA, and anti-snRNP were detected in the mouse serum using an enzyme-linked immunosorbent assay. Apoptosis of Th1 and Th2 immune cells in mice was detected using flow cytometry. Reverse transcription polymerase chain reaction was used to detect the expression of T-bet, GATA3, and Wnt3a mRNA in the spleens of each group. Western blot analysis was performed to detect the expression of Wnt1, p-ß-catenin, ß-catenin, glycogen synthase kinsase3ß (GSK-3ß), Wnt3a, c-myc, and cyclin D1 protein in mice spleens. ß-catenin in mice spleen was visualized using immunohistochemistry. RESULTS: VitD did not substantial reduce the body weight of MRL/LPR mice, whereas the inhibitor did. VitD notably decreased the concentrations of ANA, anti-double-stranded DNA, and anti-snRNP in the serum of MRL/LPR mice and alleviated apoptosis of Th1 and Th2 cells. VitD markedly increased the expression of T-bet and GATA mRNA in the spleen of MRL/LPR mice and consequently increased the levels of Wnt3a and ß-catenin. Western blot analysis revealed that the levels of GSK-3ß, p-ß-catenin, Wnt1, Wnt3a, c-myc, and cyclin D1 could be reduced by VitD, compared with MRL/LPR. Immunohistochemistry demonstrated that the expression of ß-catenin was the most pronounced in the spleen of MRL/LPR mice, and the expression level of ß-catenin decreased substantially after VitD intervention. CONCLUSIONS: VitD can further inhibit the nuclear translocation of ß-catenin by downregulating the expression of Wnt ligands (Wnt1 and Wnt3a), which reduces the expression of the downstream target gene cyclin D1. Systemic lupus erythematosus in mice was improved by inhibiting the activation of Wnt/ß-catenin signal pathway.

Follicular Helper T Cells In Peyer's Patches And Galactose-Deficient Iga1 Contribute To Iga Nephropathy.

BACKGROUND: Common primary glomerulonephritis with aberrant mucosal immunity is IgA nephropathy (IgAN). T follicular helper (TFH) cells are essential in regulating B cell differentiation. Peyer's patches (PPs) are the main site where IgA+ plasmablasts differentiate. OBJECTIVE: Our study aimed to investigate the TFH cell's potential contribution to the etiology of IgA nephropathy. MATERIALS AND METHODS: In PPs from IgAN mouse models, the ratio of the TFH cell, B220+IgA+, B220+IgM+, and B220-IgA+ lymphocytes were assessed. Then, we used Western blot to assess the expression of Bcl-6, Blimp- 1, and IL-21 proteins in PPs and used RT-PCR to assess the expression of IL-21 and TGF- 1 mRNA. TFH cells coculture with spleen cells to measure the degree of IL-21 and the ratio of activation marker CD69 on the TFH cells. Naive B cells (CD27-IgD+) from children suffering from IgAN were cultured with TFH cell-related cytokines. The supernatant was detected to assess the excretion of galactose-deficient IgA1 (Gd-IgA1). RESULTS: IgAN mice developed noticeably increased degrees of IL-21 and CD69 on TFH cells than controls did, as well as higher percentages of B220+IgA+, B220+IgM+, B220+IgA+, TGF- 1, and IL-21 mRNA and Bcl-6, IL-21 proteins in PPs. The Gd-IgA1 level in the supernatant and IgAN- positive children's serum were noticeably higher than those of the healthy controls (P < 0.05). PPs provide the microenvironment to induce the production of IgA-secreting plasmablasts. CONCLUSION: TFH cells may be a key moderator to induce B cell differentiation into IgA-secreting plasmablasts and produce Gd-IgA1, which plays a significant part in IgAN's pathogenesis. It could be a new therapeutic target in the future.

Vitamin D Activates miR-126a-5p to Target GSK-3ß and Alleviates Systemic Lupus Erythematosus in MRL/LPR Mice.

BACKGROUND: The etiology of systemic lupus erythematosus (SLE) is complex, and the disease is thus difficult to cure. In this regard, it has been established that SLE patients are characterized by differing levels of vitamin D-hydroxylation; however, the direct effects of vitamin D (VitD) in these patients remain unknown. OBJECTIVE: Therefore, we investigated the effects and mechanisms of action of VitD in the context of SLE. METHODS: The effects of VitD on MRL/LPR mice were studied by synthesizing glycogen synthase kinase-3ß (GSK-3ß)-interfering lentiviruses and transfecting with miR-126a-5p mimics. Changes in the body weight of mice were recorded for 6 weeks. Western blotting was performed to determine the levels of T-bet, GATA3, and GSK-3ß protein expression, and qRT-PCR was performed to determine the levels of miR-126a-5p and GSK-3ß mRNA expression. ELISA was performed to determine the levels of ANA, dsDNA, and snRNP/Sm in mice serum. RESULTS: GSK-3ß and miR-126a-5p were expressed at high and low levels, respectively, in MRL/LPR mice. VitD (30 ng/kg) was found to reduce the expression of GSK-3ß and increase miR-126a-5p expression, which targets GSK-3ß. T-bet and GATA3 were found to be positively regulated by miR-126a-5p and VitD and negatively regulated by GSK-3ß. The body weight of mice was not altered by VitD. ANA, dsDNA, and snRNP/Sm were positively regulated by miR- 126a-5p and VitD and negatively regulated by GSK-3ß. The effects of GSK-3ß were enhanced in response to the inhibition of miR-126a-5p expression. CONCLUSION: VitD upregulated miR-126a-5p to target GSK-3ß expression, thereby alleviating the SLE in MRL/LPR mice.

Umbilical Cord-derived Mesenchymal Stem Cells with Surfactant Protein B Alleviates Inflammatory Response in Acute Respiratory Distress Syndrome by Regulating Macrophage Polarization.

Background: Acute respiratory distress syndrome (ARDS) is a severe disorder that is related to a high mortality. Mesenchymal stem cells (MSCs) have shown strong effects in relieving lung injury. Aims: To determine the role of umbilical cord-derived MSCs (UC-MSCs) together with surfactant protein B (SP-B) in ARDS. Study Design: Animal experimentation. Methods: Immunophenotypic characteristics of UC-MSCs were identified. BALB/c mice were intratracheally administrated with lipopolysaccharide (LPS) and received UC-MSCs or UC-MSCs transfected with SP-B (UC-MSCs-SP-B). Pathological changes and lung injury degrees after transplantation were assessed by histological and biochemical analyses. Inflammatory chemokine and cytokine production in the bronchoalveolar lavage fluid (BALF) was measured using enzyme-linked immunoassay. Flow cytometry was used to examine macrophage phenotypes and differentiation of T-helper 17 (Th17) and T-regulatory (Treg) in the BALF. Results: Our results showed that isolated UC-MSCs possessed multilineage differentiation potential. SP-B transfection into UC-MSCs strengthened the effects of UC-MSCs on lung function repair in LPS-induced ARDS. UC-MSCs and UC-MSCs-SP-B attenuated cellular infiltration. Additionally, UC-MSCs and UC-MSCs-SP-B inhibited the inflammatory response by promoting M2-like polarization, as well as reduced Th17 differentiation and promoted Treg differentiation. Conclusion: UC-MSCs in combination with SP-B, alleviates inflammatory reaction in ARDS by regulating macrophage polarization.

1,25-Dihydroxyvitamin D3 ameliorates podocytopenia in rats with adriamycin-induced nephropathy.

OBJECTIVE: To investigate the role of α3ß1 integrin and α/ß-dystroglycan in protective effects of 1,25(OH)2D3 on podocytes in rats with adriamycin-induced nephropathy. METHODS: Sprague-Dawley rats were randomly divided into three groups: control group (NC), nephropathy group (NE), and nephropathy+1,25(OH)2D3 group (ND). Rats in NE and ND group were injected intravenously with adriamycin (0.1 mg/10 g body weight) to induce nephropathy, and those in ND group were then subcutaneously treated with 1,25(OH)2D3 for 8 weeks. Urinary protein level, number of urine podocytes, foot process width and glomerulosclerotic index were determined. Nephrin and podocin mRNA and protein expressions were determined by RT-PCR and western blot, respectively. Podocyte density and expressions of α3ß1 integrin and α/ß-dystroglycan (DG) were analyzed by immunohistochemistry and western blot, respectively. RESULTS: The increase in proteinuria, podocyturia and width of foot process in NE group were ameliorated after treatment with 1,25(OH)2D3 for 8 weeks. The glomerulosclerotic index was significantly decreased in ND group when compared with NE group. The podocyte density in ND group (10.3±1.64 cells/glomerulus) was significantly higher than that in NE group (8.43±1.75 cells/glomerulus) (p=0.008). 1,25(OH)2D3 treatment could significantly up-regulate the mRNA and protein expressions of nephrin and podocin, and the protein expressions of α3ß1 integrin and α/ß-DG. CONCLUSION: The expressions of nephrin, podocin, α3ß1 integrin and α/ß-DG were decreased in rats with nephropathy. However, 1,25(OH)2D3 treatment could significantly up-regulate the expressions of nephrin, podocin, α3ß1 integrin and α/ß-DG proteins which might suppress podocyte detachment and podocytopenia.

1, 25-dihydroxyvitamin D3 decreases adriamycin-induced podocyte apoptosis and loss.

BACKGROUND: Selective proteinuria is frequently observed in glomerular diseases characterized by podocyte injury. Although, 1,25-dihydroxyvitamin D3 [1,25(OH)(2)D(3)] has potential therapeutic effects on chronic kidney diseases through decreasing podocyte loss, the mechanism underlying the beneficial effects of 1,25(OH)(2)D(3) on podocytes remains still unknown. The present study tested the hypothesis that 1,25(OH)(2)D(3) directly reduced podocyte apoptosis and loss. METHODS: Sprague-Dawley (SD) rats were randomly assigned into three groups: Adriamycin (ADR) group (n=15), ADR+1,25-(OH)(2)D(3) group (n=16), and control group (n=16). Rats in ADR+1,25-(OH)(2)D(3) group were treated with 1,25(OH)(2)D(3) for 8 weeks. The number of podocytes and foot process width (FPW) were detected by transmission electron microscopy. The number of apoptotic podocytes per glomerulus and that of apoptotic nuclei and caspase-3 activity in cultured podocytes were determined by TUNEL staining. The average number of podocytes per glomerulus was quantified by immunohistochemistry. Expressions of p-Smad2/3, p-Smad1/5/8, Fas, Fas-Associated protein with Death Domain (FADD), Bax, and Bcl-2 proteins were examined by Western blot assay. RESULTS: Compared with control group, proteinuria, FPW, apoptotic podocytes, caspase-3 activity, the protein expressions of p-Smad2/3, Fas, FADD, and Bax were significantly increased, podocyte density, p-Smad1/5/8 and Bcl-2 expression were decreased in ADR group. 1,25(OH)(2)D(3) significantly reduced proteinuria, FPW, caspase-3 activity, expressions of p-Smad2/3, Fas, FADD, and Bax and apoptosis of podocytes, but increased serum albumin, number of viable podocytes , p-Smad1/5/8 and Bcl-2 expression in ADR treated rats. CONCLUSION: ADR-induced podocyte apoptosis was associated with the imbalance of p-Smad2/3, p-Smad1/5/8 the activity of caspase-3 and aberrant expressions of, Fas, FADD, Bax and Bcl-2. The beneficial effects of 1,25(OH)(2)D(3 )on podocytes may be attributable to inhibit podocyte apoptosis and the amelioration of podocytopenia.