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Objective:To investigate the role of microRNA-338-3p (miR-338-3p) in regulating the generation and function of interphotoreceptor retinoid-binding protein (IRBP) 1-20-specific T helper 17 (Th17) cells in experimental autoimmune uveitis (EAU). Methods:Bone marrow cells were flushed from the femurs and tibiae of wild-type C57BL/6 mice and cultured in the presence of granulocyte macrophage-colony stimulating factor (GM-CSF) and interleukin-4 (IL-4)to differentiate into bone marrow-derived dendritic cells (BMDCs). On day 5 after induction, immature BMDCs were collected and divided into miR-338-3p mimics transfection group and mimics negative control transfection group, then transfected with miR-338-3p mimics or negative mimics according to grouping.Twenty-four hours after transfection, the BMDCs were stimulated with 100 ng/ml of lipopolysaccharide to mature.Relative expression levels of miR-338-3p, IL-6, IL-23 and IL-1β mRNA in BMDCs of the two groups were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The EAU model was established with IRBP 1-20, incomplete Freund adjuvant and mycobacterium tuberculosis (H37Ra) in mice.On day 13 after modeling, T cells were isolated from the mice spleen or draining lymph nodes and co-cultured with miR-338-3p mimics or negative control mimics-transfected BMDCs under Th17-polarizing conditions.Concentration of IL-17 in the supernatant was detected by ELISA.Relative expression levels of retinoic acid receptor-related orphan nuclear receptor γt (RORγt) and IL-17 mRNA were analyzed by qRT-PCR.The proportion of IL-17 + cells among T cells co-cultured with BMDCs was assessed by flow cytometry.To further verify the role of miR-338-3p in dendritic cells on Th17 cells, BMDCs transfected with miR-338-3p inhibitor or control inhibitor were co-cultured with T cells isolated from spleen or draining lymph nodes of EAU mice.Concentration of IL-17 in the supernatant was detected by ELISA.The use and care of the animals complied with Regulations for the Administration of Affairs Concerning Experiment Animals by State Science and Technology Commission.The study protocol was approved by the Institutional Animal Care and Use Committee of Tianjin Medical University (No.TJYY2019110117). Results:Relative expression level of miR-338-3p in BMDCs was significantly increased in the miR-338-3p mimics transfection group than the mimics negative control group ( t=6.861, P=0.002). In T cells co-cultured with miR-338-3p mimics-transfected BMDCs, the relative expression levels of RORγt and IL-17 mRNA were 1.34±0.16 and 1.33±0.16, which were significantly higher than 1.00±0.01 and 1.00±0.01 in the mimics negative control group ( t=3.632, P=0.022; t=3.681, P=0.021). ELISA showed that the concentration of IL-17 in the supernatant was (5 941.00±452.40)pg/ml in the miR-338-3p mimics transfection group, which was significantly higher than (4 299.00±348.30)pg/ml in the mimics negative control group ( t=4.979, P=0.008), and IL-17 concentration in the supernatant was (3 092.00±200.90)pg/ml in the miR-338-3p inhibitor transfection group, which was lower than (4 063.00±131.50)pg/ml in the inhibitor negative control group ( t=7.005, P=0.002). The proportion of IL-17 + cells among T cells was (8.03±1.35)% in the miR-338-3p mimics transfection group, which was significantly higher than (4.52±0.73)% in the mimics negative control group ( t=3.968, P=0.017). The relative expression levels of IL-6, IL-23, and IL-1β mRNA were 2.23±0.21, 2.21±0.56, 2.32±0.43, respectively in the miR-338-3p mimics transfection group, which were significantly higher than 1.00±0.06, 1.00±0.07, 1.01±0.15 in the mimics negative control group ( t=10.290, P=0.001; t=3.747, P=0.020; t=5.280, P=0.006). Conclusions:Overexpression of miR-338-3p in BMDCs can promote the IRBP 1-20-specific Th17 cell response by increasing the expression of Th17-polarizing cytokines including IL-6, IL-1β and IL-23.
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Ulcerative colitis (UC) manifests as an etiologically complicated and relapsing gastrointestinal disease. The enteric nervous system (ENS) plays a pivotal role in rectifying and orchestrating the inflammatory responses in gut tract. Berberine, an isoquinoline alkaloid, is known as its anti-inflammatory and therapeutic effects in experimental colitis. However, little research focused on its regulatory function on ENS. Therefore, we set out to explore the pathological role of neurogenic inflammation in UC and the modulating effects of berberine on neuro-immune interactions. Functional defects of enteric glial cells (EGCs), with decreased glial fibrillary acidic protein (GFAP) and increased substance P expression, were observed in DSS-induced murine UC. Administration of berberine can obviously ameliorate the disease severity and restore the mucosal barrier homeostasis of UC, closely accompanying by maintaining the residence of EGCs and attenuating inflammatory infiltrations and immune cells overactivation. , berberine showed direct protective effects on monoculture of EGCs, bone marrow-derived dendritic cells (BMDCs), T cells, and intestinal epithelial cells (IECs) in the simulated inflammatory conditions. Furthermore, berberine could modulate gut EGCs-IECs-immune cell interactions in the co-culture systems. In summary, our study indicated the EGCs-IECs-immune cell interactions might function as a crucial paradigm in mucosal inflammation and provided an infusive mechanism of berberine in regulating enteric neurogenic inflammation.
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BACKGROUND: The genus Flavivirus consists of many emerging arboviruses, including Dengue virus (DV), Japanese encephalitis virus (JEV) and West Nile virus (WNV). Effective preventive vaccines remain elusive for these diseases. Mice are being increasingly used as the animal model for vaccine studies. However, the pathogenic mechanisms of these viruses are not clearly understood. Here, we investigated the interaction of DV and JEV with murine bone marrow-derived dendritic cells (bmDC). METHODS: ELISA and FACS analysis were employed to investigate cytokine production and phenotypic changes of DCs obtained from bone marrow following flavivirus infection. RESULTS: We observed that these viruses altered the cytokine profile and phenotypic markers. Although both viruses belong to the same family, JEV-infected bmDC produced anti-inflammatory cytokine (IL-10) along with pro-inflammatory cytokines, whereas DV infection induced production of large amounts of pro-inflammatory cytokines (IL-6 and TNF-alpha) and no IL-10 from murine bmDCs. Both flaviviruses also up-regulated the expression of co-stimulatory molecules such as CD40, CD80 and CD86. JEV infection led to down-regulation of MHC II expression on infected bmDCs. We also found that cytokine production induced by JEV and DV is MyD88-dependent. This dependence was complete for DV, as cytokine production was completely abolished in the absence of MyD88. With regard to JEV, the absence of MyD88 led to a partial reduction in cytokine levels. CONCLUSION: Here, we demonstrate that MyD88 plays an important role in the pathogenesis of flaviviruses. Our study provides insight into the pathogenesis of JEV and DV in the murine model.