'Circulating' T follicular helper cells (Tfh), characterized by their surface phenotypes CD4 chemokine receptor 5 (CXCR5) inducible co-stimulatory molecule (ICOS) , have been identified as the CD4 T cell subset specialized in supporting the activation, expansion and differentiation of B cells. Fibroblast-like synoviocytes (FLS) are critical in promoting inflammation and cartilage destruction in rheumatoid arthritis (RA), and the interaction between FLS and T cells is considered to facilitate FLS activation and T cell recruitment. However, it remains unknown whether RA-FLS co-cultured with activated peripheral blood mononuclear cells (PBMC) has immunoregulatory effects on peripheral Tfh. In the present study, we co-cultured RA-FLS with or without anti-CD3/CD28-stimulated PBMC. The results showed that RA-FLS co-cultured with stimulated PBMC could increase the numbers of CD4 CXCR5 ICOS T cells of RA PBMC possibly via the production of interleukin (IL)-6, a critical cytokine involved in the differentiation of Tfh cells. We also observed increased reactive oxygen species (ROS) levels in the co-culture system of RA-FLS and PBMC. The percentage of CD4 CXCR5 ICOS T cells was decreased when ROS production was inhibited by N-acetyl-L-cysteine (NAC), a specific inhibitor which can decrease ROS production. In addition, we showed that the higher levels of tumour necrosis factor (TNF)-α and IL-1β in the co-culture system and the blocking of TNF receptor 2 (TNF-R2) and IL-1β receptor (IL-1βR) both decreased the numbers of CD4 CXCR5 ICOS T cells. Our study reveals a novel mechanistic insight into how the interaction of RA-FLS and PBMC participates in the RA pathogenesis, and also provides support for the biologicals application for RA.

IL-34 is a pleiotropic cytokine, which is a key regulator of monocytes/macrophages and might participate in the pathogenesis of RA. In this study, we aimed to explore the effect of IL-34 on the monocyte-like cell line THP-1 and the quantitative variation of Th17 cells in THP-1 and RA CD4T cells coculture system. CD4T cells were purified from RA PBMC using immunomagnetic beads. THP-1 were cultured with RA CD4T cells. The frequency of Th17 cells was determined by FACS. Fluorscence indensity and expression of ROS were detected by FACS and cell staining, respectively. The expression of IL-6, IL-23, IL-21, TNF-α and IL-1β in the coculture supernatants were detected by ELISA. We found that CSF-1R was constitutively expressed on peripheral monocytes as well as THP-1, but not on the T/B cells. IL-34-CSF-1R binding could activate THP-1 to secret IL-6. IL-34 could up-regulate the numbers of Th17 cells in coculture system, which was possibly via the production of IL-6. We further observed ROS levels were increased in the coculture system. The percentage of Th17 cells was reduced when ROS production was inhibited by NAC, a specific inhibitor of ROS production. In addition, TNFRII antagonist but not IL-1βR antagonist could restrict the production of ROS, expression of IL-6 and generation of Th17 cells. In conclusion, IL-34-stimulated THP-1 can produce higher levels of ROS, which promoted IL-6 secretion and up-regulated Th17 cells. Our study suggests a novel mechanistic insight into how the interaction of IL-34-stimulated monocytes and CD4T cells participates in the RA pathogenesis.

Non-small cell lung cancer (NSCLC) constitutes the majority of all lung-cancer cases. Aquaporin 5 (AQP5) may be involved in NSCLC by promoting lung-cancer initiation and progression. The present study aimed to determine the role of AQP5 in migration and angiogenesis using NSCLC cells and HUVECs. AQPs 1, 3, 4, 5, 8 and 9 were screened in the NSCLC cell line H1299, and the present results showed that AQP5 mRNA was upregulated compared with the other AQP genes. At the protein level, AQP5 was significantly increased in H1299 cells compared with 16HBE cells. AQP5 knockdown in H1299 cells significantly decreased cell migration compared with untransfected cells, as demonstrated by both Transwell and wound closure assays. The present study further investigated H1299 ability to promote HUVEC vascularisation. The supernatants of both transfected and untransfected H1299 cells were used as conditioned medium for HUVECs, and tube formation was measured. The supernatant of AQP5-downregulated cells exhibited significantly low tube formation potential compared with untransfected cells. Similarly, vascular endothelial growth factor was significantly increased in control cells (si-NC) compared with cells transfected with small interfering RNA targeting AQP5. The present study found that AQP5 downregulation significantly decreased the phosphorylation level of epidermal growth factor receptor and the activity of the ERK1/2 pathway. In summary, the present study suggested that AQP5 influenced migration and angiogenesis in NSCLCs in vitro and may potentially exhibit similar in vivo effects.

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compromised the production of inflammatory factors in TL1A-stimulated RA-FLS, suggesting that mitochondrial dysfunction mediated by the TL1A/TNFR2 axis might amplify the inflammatory response via regulation of mitochondria-derived ROS generation. Collectively, our results reveal that TL1A might be involved in making FLS more aggressive in RA pathogenesis via cell respiration interruption.