Aquaporin 5 promotes tumor migration and angiogenesis in non-small cell lung cancer cell line H1299.

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.

TL1A/TNFR2-mediated mitochondrial dysfunction of fibroblast-like synoviocytes increases inflammatory response in patients with rheumatoid arthritis via reactive oxygen species generation.

Rheumatoid arthritis (RA) is the major autoimmune destructive disease of joints with a complicated pathogenesis. The contribution of tumor necrosis factor-like ligand 1A (TL1A) in RA pathogenesis, especially on fibroblast-like synoviocytes (FLS), has been suggested clinically. The present study investigated the role of TL1A in mitochondrial dysfunction, induced oxidative stress in mitochondria, apoptosis resistance and the inflammatory response in FLS obtained from RA patients (RA-FLS). RA-FLS were incubated with TL1A and tumor necrosis factor receptor 2 (TNFR2) antagonist. Respiratory function, mitochondrial membrane potential and respiration associated genes of mitochondria were measured in both TL1A stimulated and non-stimulated RA-FLS. Additionally, the effects of TL1A on reactive oxygen species (ROS) production in mitochondria, apoptosis and the inflammatory response in RA-FLS were also assessed. The role of TL1A in association between ROS generation, especially mitochondrial type and the inflammatory response, was evaluated by measuring inflammation-related cytokines and signaling pathways using ROS inhibitors, diphenyleneiodonium chloride and Mito-TEMPO (Sigma-Aldrich, Miamisburg, OH, USA). We found that TL1A induced mitochondrial dysfunction by weakening mitochondrial respiration and membrane potential, which was blocked by a TNFR2 antagonist. Increased ROS synthesis in impaired mitochondria was observed with MitoSOX (Invitrogen, CA, USA) immunofluorescence staining in TL1A-stimulated RA-FLS but inhibited by a TNFR2 antagonist. TL1A influenced apoptosis resistance and inflammatory mediators via TNFR2. Inhibition of mitochondria-derived ROS 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.

ER-stressed MSC displayed more effective immunomodulation in RA CD4+CXCR5+ICOS+ follicular helper-like T cells through higher PGE2 binding with EP2/EP4.

Objectives: To analyze the further immunomodulatory effects of endoplasmic reticulum (ER)-stressed umbilical cord-derived mesenchymal stem cells MSCs (UC-MSCs) on rheumatoid arthritis (RA) CD4+CXCR5+ICOS+ T (follicular helper-like T, Tfh) cells.Methods: MSCs were isolated from umbilical cord and surface markers were identified by flow cytometry. CD4+ T cells were purified from RA patients' peripheral blood mononuclear cells (PBMCs) using immunomagnetic beads. Thapsigargin (Tg)-stimulated or unstimulated MSCs were co-cultured with RA CD4+ T cells. CD4+CXCR5+ICOS+ T cells were analyzed with fluorescence activating cell sorter (FACS) and major soluble factors secreted by MSCs were detected by qRT-PCR as well as ELISA. Receptors of prostanoid E2 (PGE2), known as EP1-4, on CD4+ T cells were tested with RT-PCR and FACS. Proportion of CD4+CXCR5+ICOS+ T cells was determined after EP2/EP4 antagonists and anti-IL-6R antibody was added into co-cultured system, respectively.Results: ER-stressed MSCs further down-regulated peripheral CD4+CXCR5+ICOS+ T cells compared with Tg-stimulated MSCs and CD4+ T co-cultured group. PGE2 and IL-6 increased obviously in the supernatants. EP2/EP4 could be detected on CD4+ T cells and frequencies of CD4+CXCR5+ICOS+ T cells were upregulated when EP2 and/or EP4 antagonists rather than anti-IL-6R antibody were added.Conclusions: ER-stressed MSCs exhibited better inhibition effect on RA CD4+CXCR5+ICOS+ T cells by releasing PGE2, indicating the immunosuppressive effect of MSCs could be enhanced by induction of ER stress.

TL1A mediates fibroblast-like synoviocytes migration and Indian Hedgehog signaling pathway via TNFR2 in patients with rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by joints inflammation. One of the aggressive characteristics of RA fibroblast-like synoviocytes (FLS) is the tendency for migration in the local environment, which plays a central role in the RA pathogenesis. Tumor Necrosis Factor (TNF)-like cytokine 1A (TL1A) is a member of TNF superfamily, which has a role in autoimmunity and influences the RA-FLS behavior through TNF receptor 2 (TNFR2). We investigated the effect of TNF-like cytokine 1A (TL1A) on RA-FLS migration using patients' samples. Specifically, we examined the hedgehog signaling pathway which is a key regulator in chondrocyte growth and differentiation. We found that TL1A increased significantly the hedgehog homologue Indian hedgehog (IHH) and its receptor Patched 1, 2 (PTCH 1, 2) in RA-FLS. In addition, TL1A-stimulated RA-FLS promoted significantly IHH protein expression. However, both mRNA and protein levels decreased substantially after blocking TL1A with TNFR2 antagonist. The migratory property of RA-FLS was enhanced after stimulation of RA-FLS with TL1A, but was compromised following TL1A blockage. In conclusion, our study has revealed that TL1A modulated RA-FLS migration and Indian hedgehog signaling pathway using TNFR2.

Leptin Upregulates Peripheral CD4+CXCR5+ICOS+ T Cells via Increased IL-6 in Rheumatoid Arthritis Patients.

CD4+CXCR5+ICOS+ T cells, known as Tfh (T Follicular helper) cells, are required for antibody production. Abnormal production and differentiation of Tfh cells are involved in many autoimmune diseases, including rheumatoid arthritis (RA). Leptin has the property of modulating immune system. Here, we explored the effect of leptin on CD4+CXCR5+ICOS+ T cells production in RA patients. Serum leptin levels were measured by enzyme-linked immunosorbent assay (ELISA). Peripheral blood mononuclear cells (PBMC) stimulated with CD3/CD28 were cultured in the presence and absence of leptin and with or without anti-IL-6 receptor (anti-IL-6R), anti-IL-21R, and anti-IL-12R antibody respectively. IL-6, IL-21, and IL-12 levels were determined by ELISA. Bcl-6 was detected by reverse transcription-polymerase chain reaction. STAT1, pSTAT1, STAT3, and pSTAT3 were examined by western blot. We found that leptin levels were higher in RA patients than healthy controls. Leptin-stimulated RA PBMC upregulated CD4+CXCR5+ICOS+ T cells, along with increased IL-6, IL-21, and IL-12.CD4+CXCR5+ICOS+ T cells, Bcl-6 mRNA expression, pSTAT1, and pSTAT3 obviously declined when anti-IL-6R antibody was added into leptin-treated RA PBMC, which suggested that leptin upregulated RA CD4+CXCR5+ICOS+ T cells via increased IL-6 by activation of STAT1 and STAT3. We presented an innovative mechanism on how leptin participated in RA pathogenesis.

Increased IL-6 expression on THP-1 by IL-34 stimulation up-regulated rheumatoid arthritis Th17 cells.

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 CD4+T cells coculture system. CD4+T cells were purified from RA PBMC using immunomagnetic beads. THP-1 were cultured with RA CD4+T 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-1ß 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-1ßR 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 CD4+T cells participates in the RA pathogenesis.