scholarly journals SIRT1 inhibits rheumatoid arthritis fibroblast-like synoviocyte aggressiveness and inflammatory response via suppressing NF-κB pathway

2018 ◽  
Vol 38 (3) ◽  
Author(s):  
Guoqing Li ◽  
Zhongbing Xia ◽  
Ying Liu ◽  
Fanru Meng ◽  
Xia Wu ◽  
...  

Rheumatoid arthritis (RA) is an autoimmune disease of the joints characterized by synovial hyperplasia and chronic inflammation. Fibroblast-like synoviocytes (FLS) play a central role in RA initiation, progression, and perpetuation. Prior studies showed that sirtuin 1 (SIRT1), a deacetylase participating in a broad range of transcriptional and metabolic regulations, may impact cell proliferation and inflammatory responses. However, the role of SIRT1 in RA–FLS was unclear. Here, we explored the effects of SIRT1 on the aggressiveness and inflammatory responses of cultured RA-FLS. SIRT1 expression was significantly lower in synovial tissues and FLS from RA patients than from healthy controls. Overexpression of SIRT1 significantly inhibited RA-FLS proliferation, migration, and invasion. SIRT1 overexpression also significantly increased RA-FLS apoptosis and caspase-3 and -8 activity. Focusing on inflammatory phenotypes, we found SIRT1 significantly reduced RA-FLS secretion of TNF-α, IL-6, IL-8, and IL-1β. Mechanistic studies further revealed SIRT1 suppressed NF-κB pathway by reducing p65 protein expression, phosphorylation, and acetylation in RA-FLS. Our results suggest SIRT1 is a key regulator in RA pathogenesis by suppressing aggressive phenotypes and inflammatory response of FLS. Enhancing SIRT1 expression or function in FLS could be therapeutic beneficial for RA by inhibiting synovial hyperplasia and inflammation.

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Wei Qu ◽  
Ling Jiang ◽  
Guanhua Hou

Abstract Background Circular RNAs (circRNAs) are associated with rheumatoid arthritis (RA) development. The purpose of this study is to explore the function and mechanism of circRNA fragile mental retardation 2 (circ-AFF2) in the processes of rheumatoid arthritis fibroblast-like synoviocytes (RAFLSs). Methods Circ-AFF2, microRNA (miR)-650, and 2′,3′-cyclic nucleotide 3′-phosphodiesterase (CNP) levels were determined in synovial tissues of RA and RAFLSs by quantitative reverse transcription polymerase chain reaction or Western blotting. Cell proliferation, inflammatory response, apoptosis, caspase3 activity, migration, invasion, and epithelial-mesenchymal transition (EMT) were investigated using Cell Counting Kit-8 (CCK-8), enzyme-linked immunosorbent assay (ELISA), flow cytometry, Transwell, and Western blotting analyses. Dual-luciferase reporter, RNA immunoprecipitation (RIP), and pull-down assays were performed to assess the binding relationship. Results Circ-AFF2 expression level was enhanced in synovial tissues of RA and RAFLSs. Circ-AFF2 overexpression facilitated cell proliferation, inflammatory response, migration, invasion, and EMT and repressed apoptosis in RAFLSs. Circ-AFF2 downregulation played an opposite role. Circ-AFF2 targeted miR-650, and miR-650 downregulation reversed the effect of circ-AFF2 interference on RAFLS processes. CNP was targeted by miR-650, and circ-AFF2 increased CNP expression by regulating miR-650. MiR-650 overexpression constrained cell proliferation, inflammatory response, migration, invasion, and EMT and contributed to apoptosis by decreasing CNP in RAFLSs. Conclusion Circ-AFF2 promoted proliferation, inflammatory response, migration, and invasion of RAFLSs by modulating the miR-650/CNP axis.


Life ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 587
Author(s):  
Fu-Tzu Pai ◽  
Cheng-You Lu ◽  
Chia-Hsin Lin ◽  
John Wang ◽  
Ming-Cheng Huang ◽  
...  

Background: Rheumatoid arthritis is an autoimmune disease that may lead to severe complications. The fruit of Psoralea corylifolia L. (PCL) is widely used in traditional Chinese medicine as a well-known herbal treatment for orthopedic diseases. However, there is a lack of studies of its effects on rheumatoid arthritis. The purpose of the study was to investigate the effects and mechanisms of concentrated herbal granules of PCL on rheumatoid arthritis to provide some insights for future development of new drug for the treatment of rheumatoid arthritis. Methods: We used collagen-induced arthritis (CIA) DBA/1J mice as an experimental model to mimic human rheumatoid arthritis. The mice were immunized with collagen on days 0 and 21 and then orally administered 200 mg/kg/day PCL on days 22–49. Starch was used as a control. The mice were sacrificed on day 50. Clinical phenotypes, joint histopathology, and immunological profiles were measured. Results: Compared to the CIA or CIA + Starch group, the CIA + PCL group had significantly ameliorated clinical severity and decreased paw swelling. Histopathological analysis of the hind paws showed that PCL mitigated the erosion of cartilage and the proliferation of synovial tissues. There were significant differences in the levels of TNF-α, IL-6 and IL-17A, as measured by ELISA, and the percentages of CD4 + IL-17A+, CD4 + TNF-α+, CD4 + IFN-γ+ T cells. Furthermore, we also found that in mice treated with CIA + PCL, the percentage and number of bone marrow-derived suppressor cells (MDSCs; Gr1+ CD11b+) increased significantly. Conclusions: We provided evidence for the potential antiarthritic effects of PCL through the inhibition of inflammation and increase of MDSCs. These findings indicate that PCL may be a promising therapeutic herb for the treatment of rheumatoid arthritis.


2021 ◽  
Author(s):  
Kim Chiok ◽  
Kevin Hutchison ◽  
Lindsay Grace Miller ◽  
Santanu Bose ◽  
Tanya A Miura

Critically ill COVID-19 patients infected with SARS-CoV-2 display signs of generalized hyperinflammation. Macrophages trigger inflammation to eliminate pathogens and repair tissue, but this process can also lead to hyperinflammation and resulting exaggerated disease. The role of macrophages in dysregulated inflammation during SARS-CoV-2 infection is poorly understood. We used SARS-CoV-2 infected and glycosylated soluble SARS-CoV-2 Spike S1 subunit (S1) treated THP-1 human-derived macrophage-like cell line to clarify the role of macrophages in pro-inflammatory responses. Soluble S1 upregulated TNF-α and CXCL10 mRNAs, and induced secretion of TNF-α from THP-1 macrophages. While THP-1 macrophages did not support productive SARS-CoV-2 replication, virus infection resulted in upregulation of both TNF-α and CXCL10 genes. Our study shows that S1 is a key viral component inducing inflammatory response in macrophages, independently of virus replication. Thus, virus-infected or soluble S1-activated macrophages may become sources of pro-inflammatory mediators contributing to hyperinflammation in COVID-19 patients.


2019 ◽  
Vol 65 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Hong Xiao Cui ◽  
Xiu Rong Xu

Rabbit is susceptible to intestinal infection, which often results in severe inflammatory response. To investigate whether the special community structure of rabbit intestinal bacteria contributes to this susceptibility, we compared the inflammatory responses of isolated rabbit crypt and villus to heat-treated total bacteria in pig, chicken, and rabbit ileal contents. The dominant phylum in pig and chicken ileum was Firmicutes, while Bacteroidetes was dominant in rabbit ileum. The intestinal bacteria from rabbit induced higher expression of toll-like receptor 4 (TLR4) in rabbit crypt and villus (P < 0.05). TLR2 and TLR3 expression was obviously stimulated by chicken and pig intestinal bacteria (P < 0.05) but not by those of rabbit. The ileal bacteria from those three animals all increased the expression of tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) in crypts and villus (P < 0.05). Chicken and pig ileal bacteria also stimulated the expression of anti-inflammatory factors interferon beta (IFN-β) and IL-10 (P < 0.05), while those of rabbit did not (P > 0.05). In conclusion, a higher abundance of Gram-negative bacteria in rabbit ileum did not lead to more expressive pro-inflammatory cytokines in isolated rabbit crypt and villus, but a higher percentage of Lactobacillus in chicken ileum might result in more expressive anti-inflammatory factors.


2003 ◽  
Vol 10 (5) ◽  
pp. 813-820 ◽  
Author(s):  
Silvia Fernández-Serrano ◽  
Jordi Dorca ◽  
Mercè Coromines ◽  
Jordi Carratalà ◽  
Francesc Gudiol ◽  
...  

ABSTRACT In order to analyze the characteristics of the inflammatory response occurring in blood during pneumonia, we studied 38 patients with severe community-acquired pneumonia. Venous and arterial blood samples were collected at study entry and on days 1, 2, 3, 5, and 7 after inclusion. The concentrations of proinflammatory (tumor necrosis factor alpha [TNF-α], interleukin 1β [IL-1β], IL-6, and IL-8) and anti-inflammatory (IL-10) cytokines were determined in order to detect differences related to the origin of the sample, the causative organism, the clinical variables, and the final outcome of the episode. Legionella pneumonia infections showed higher concentrations of TNF-α, IL-6, IL-8, and IL-10. After 24 h, plasma IL-6, IL-8, and IL-10 concentrations in pneumococcal episodes increased, whereas in the same time interval, cytokine concentrations in Legionella episodes markedly decreased. The characteristics of the inflammatory response in bacteremic pneumococcal episodes were different from those in nonbacteremic episodes, as indicated by the higher plasma cytokine concentrations in the former group. Finally, our analysis of cytokine concentrations with regard to the outcome—in terms of the need for intensive care unit admittance and/or mechanical ventilation as well as mortality—suggests that there is a direct relationship between the intensity of the inflammatory response measured in blood and the severity of the episode.


2021 ◽  
Vol 18 (10) ◽  
pp. 2011-2017
Author(s):  
Lan Chai ◽  
Xian Zhen Zhang ◽  
Hai fang Ma ◽  
Fang Yuan

Purpose: To investigate the effect of microRNA 498 (miR-498) on proliferation and inflammation of rheumatoid arthritis (RA) fibroblast-like synoviocytes (RA-FLSs) in rheumatoid arthritis (RA). Methods: MiR-498 level was evaluated in both RA synovial tissues and RA-FLSs using real-time polymerase chain reaction (PCR). MicroRNA-498 overexpression or knockdown was performed in RAFLSs. Proliferation, apoptosis, cell cycle and inflammation induced by miR-498 mimics or inhibitor were used to explore the function of miR-498 in RA. Results: Expression level of miR-498 was downregulated in both RA synovial tissues and RA- FLSs. MicroRNA-498 mimics decreased proliferation and arrested cell cycle, whereas miR-498 inhibitor caused the opposite effects in RA-FLSs. In addition, miR-498 mimics suppressed inflammation and promoted cell apoptosis, while miR-498 inhibitor promoted inflammation and inhibited cell apoptosis in RA-FLSs. Furthermore, the effect of miR-498 on the proliferation, inflammation and apoptosis of RAFLSs was mediated by its ability to target and downregulate JAK1. Conclusion: These results indicate that miR-498 inhibits the proliferation and inflammatory responses of RA-FLSs by targeting JAK1, thus revealing a new therapeutic target for RA treatment.


2020 ◽  
Vol 40 (8) ◽  
Author(s):  
Shanshan Yang ◽  
Wei Yin ◽  
Yan Ding ◽  
Fan Liu

Abstract Backgrounds: Rheumatoid arthritis (RA) is a frequent autoimmune disease. Emerging evidence indicated that ZNFX1 antisense RNA1 (ZFAS1) participates in the physiological and pathological processes in RA. However, knowledge of ZFAS1 in RA is limited, the potential work pathway of ZFAS1 needs to be further investigated. Methods: Levels of ZFAS1, microRNA (miR)-2682-5p, and ADAM metallopeptidase with thrombospondin type 1 motif 9 (ADAMTS9) were estimated using quantitative real-time polymerase chain reaction (qRT-PCR) assay. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was conducted to explore the ability of cell proliferation in fibroblast-like synoviocytes (FLS-RA). Cell apoptosis was measured via flow cytometry. Also, levels of ADAMTS9, apoptosis-related proteins, cleaved-caspase-3 (active large subunit), and autophagy-related proteins were identified adopting Western blot. Enzyme-linked immunosorbent assay (ELISA) was performed to determine the productions of inflammatory cytokines. Beside, the interrelation between miR-2682-5p and ZFAS1 or ADAMTS9 was verified utilizing dual-luciferase reporter assay. Results: High levels of ZFAS1 and ADAMTS9, and a low level of miR-2682-5p were observed in RA synovial tissues and FLS-RA. Knockdown of ZFAS1 led to the curbs of cell proliferation, inflammation, autophagy, and boost apoptosis in FLS-RA, while these effects were abolished via regaining miR-2682-5p inhibition. Additionally, the influence of miR-2682-5p on cell phenotypes and inflammatory response were eliminated by ADAMTS9 up-regulation in FLS-RA. Mechanically, ZFAS1 exerted its role through miR-2682-5p/ADAMTS9 axis in RA. Conclusion: ZFAS1/miR-2682-5p/ADAMTS9 axis could modulate the cell behaviors, inflammatory response in FLS-RA, might provide a potential therapeutic target for RA treatment.


2021 ◽  
Author(s):  
He Tong ◽  
Li Wang ◽  
Kefan Zhang ◽  
Jing Shi ◽  
yongshuai Wu ◽  
...  

Abstract BackgroundThe phagocytic S100 protein, which mediates inflammatory responses and recruits inflammatory cells to sites of tissue damage, has long been known to be expressed in cells of myeloid origin. S100A6 belongs to the A group of the S100 protein family of Ca2+-binding proteins. Currently, the mechanism by which S100A6 mediates the inflammatory response and recruits inflammatory cells to the tissue injury site is unknown.MethodsA mouse model of carbon tetrachloride (CCl4)-induced acute liver injury (ALI) was established, and the transcriptomes of postinjury 2d and 5d liver tissues were sequenced. Enzyme-linked immunosorbent assay was used to determine the expression of inflammatory factors (TNF-α, IL-1β, IL-6, and IL-8) in the supernatant of the liver. Immunohistochemical analysis confirmed the expression of S100A6 in the liver cells. In vitro experiments proved the pro-inflammatory function of S100A6, and western blotting (WB) showed that the pathways were activated. The transwell experiment showed the infiltration of mononuclear/macrophages.ResultsWe found that S100A6 is highly expressed in liver cells during the most severe period of ALI, suggesting that it acts as an endogenous danger signal and has a pro-inflammatory function. In vitro, the mouse S100A6 recombinant protein was used to stimulate liver Kupffer cells to promote the secretion of TNF-α, IL-1β, IL-6, and IL-8. Further mechanistic experiments revealed that S100A6 acts as an endogenous danger signal to activate p-P38 and p-JNK downstream of the TLR4 and P65 pathways. Similarly, transcriptome data showed that S100A6 can activate the inflammatory response in Kuffer cells. WB revealed that S100A6 had no significant effect on cell apoptosis. To continue to explore the mechanism of monocyte/macrophage infiltration, we found that TNF-α stimulates liver cells as the main source of CCL2. TNF-α can initiate the p-P38 and p-JNK pathways of liver cells to produce CCL2, thereby recruiting the infiltration of mononuclear/macrophages. ConclusionsTaken together, S100A6 is an endogenous danger signal that mediates inflammatory responses and recruits inflammatory cells to sites of tissue damage.


2020 ◽  
Author(s):  
Ha-Reum Lee ◽  
Su-Jin Yoo ◽  
Jinhyun Kim ◽  
In Seol Yoo ◽  
Chan Keol Park ◽  
...  

Abstract Background: Reactive oxygen species (ROS) regulate the migration and invasion of fibroblast-like synoviocytes (FLS), which are key effector cells in rheumatoid arthritis (RA) pathogenesis. Nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4) induces ROS generation and consequently, enhances cell migration. Despite the important interrelationship between RA, FLS, and ROS, the effect of NOX4 on RA pathogenesis remains unclear. Methods: FLS isolated from RA (n=5) and osteoarthritis (OA, n=5) patients were stimulated with recombinant interleukin 17 (IL-17; 10 ng/ml) and tumor necrosis factor alpha (TNF-α; 10 ng/ml) for 1 h. Cell migration, invasion, adhesion molecule expression, vascular endothelial growth factor (VEGF) secretion, and ROS expression were examined. The mRNA and protein levels of NOX4 were analyzed by RT-qPCR and western blotting, respectively. The NOX4 inhibitor GLX351322 and NOX4 siRNA were used to inhibit NOX4 to probe the effect of NOX4 on these cellular processes. Results: Migration of RA FLS was increased 2.48-fold after stimulation with IL-17 and TNF-α, while no difference was observed for OA FLS. ROS expression increased in parallel with invasiveness of FLS following cytokine stimulation. When the expression of NOX was examined, NOX4 was significantly increased by 9.73-fold in RA FLS compared to unstimulated FLS. Following NOX4 inhibition, cytokine-induced vascular cell adhesion molecule 1 (VCAM1), VEGF, and migration and invasion capacity of RA FLS were markedly decreased to unstimulated levels. Conclusion: NOX4 is a key contributor to cytokine-enhanced migration and invasion via modulation of ROS, VCAM1, and VEGF in RA FLS.


2020 ◽  
Author(s):  
Jianting Wen ◽  
Jian Liu ◽  
Xin Wang ◽  
Jie Wang

Abstract Background: The present study explored the possible functions and the underlying mechanism of long Non-coding RNA LINC02085 in rheumatoid arthritis (RA). Methods: Primary fibroblast-like synoviocytes (FLS) were separated from synovial tissues and was established cell lines, then cultured for subsequent cell experiments by transfecting different vectors. Rat with AA were injected with sh-LINC02085. The progression of AA was explored by measuring arthritis score and histologic analysis. ELISA analysis was employed to detect the levels of inflammatory cytokines. CCK8 assay, migration and invasion assays were used to evaluate the proliferation, migration and invasion abilities of cells, respectively. Besides, the levels of the the PI3K/AKT pathway-related proteins were measured by WB and IF. Results: The expression level of LINC02085 was significant high in patients with RA, and positively associated with clinical indexes. We found that LINC02085 was upregulated in RA -FLS and TNF-αstimulated. And overexpression of LINC02085 could promote proliferation, migration and invasion induced by TNF-α, through upregulating the levels of TNF-αand TNFAIP2 and promoting the activation of PI3K/AKT pathway. Whereas downexpression of LINC02085 received the opposite results. Knockdown of LINC02085 significantly ameliorated the progression of AA reflected by decreased arthritis score and cartilage destruction. Conclusion: The present study revealed that LINC02085 could regulate cell growth and inflammatory response of RA-FLS by activating the PI3K/ AKT signaling pathway, subsequently playing important roles in promoting the occurrence and development of RA.


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