RESUMO
BACKGROUND: Autoimmune 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. METHODS: An 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. RESULTS: Administration 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. CONCLUSION: Vitamin D3 attenuates AITD by modulating Th17/Treg cell balance via regulating the YAP/JAK1/STAT1 axis.
RESUMO
Four alkaloids were isolated from Portulaca oleracea L., including two new compounds, 2-(4-amino-6-hydroxy-1,6-dihydropyrimidin-5-yl)-5-(hydroxymethyl)tetrahydrofuran-3,4-diol, named Olerapyrimidine (1) and (2 R,3S,4S,5R,6S)-2-(hydroxymethyl)-6-((6-hydroxypyridin-3-yl)oxy)tetrahydro-2H-pyran-3,4,5-triol, named Olerapyridine (2), and two known compounds including 1H-imidazole (3) and (5S, 6 R, 7S, 8 R)-5-amino-(2Z,4Z)-1,2,3-trihydroxybuta-2,4-dienyloxy-pentane-6,7,8,9-tetraol (4) from P. oleracea for the first time. Their structures were determined by spectroscopic methods, including UHPLC-ESI-Q-TOF/MS, 1D and 2D NMR spectra. Both Olerapyrimidine and Olerapyridine at 20 µM could inhibit the inflammatory factors, IL-1ß and TNF-α in the RAW 264.7 cells induced by LPS.