In this study, we found that catechins found in green tea (EGCG, EGC, and EC) differentially interfere with the IL-1β signaling pathway which regulates the expression of pro-inflammatory mediators (IL-6 and IL-8) and Cox-2 in primary human rheumatoid arthritis synovial fibroblasts (RASFs). EGCG and EGC inhibited IL-6, IL-8, and MMP-2 production and selectively inhibited Cox-2 expression. EC did not exhibit any inhibitory effects. When we looked at the expression of key signaling proteins in the IL-1β signaling pathway, we found all the tested catechins could inhibit TAK-1 activity. Therefore, the consumption of green tea offers an overall anti-inflammatory effect. Molecular docking analysis confirms that EGCG, EGC, and EC all occupy the active site of the TAK1 kinase domain. However, EGCG occupies the majority of the TAK1 active site. In addition to TAK1 inhibition, EGCG can also inhibit P38 and nuclear NF-κB expression whereas EC and EGC were not effective inhibitors. Our findings suggest one of the main health benefits associated with the consumption of green tea are due to the activity of EGCG and EGC which are both present at higher amounts. Although EGCG is the most effective catechin at inhibiting downstream inflammatory signaling, its effectiveness could be hindered by the presence of EC. Therefore, varying EC content in green tea may reduce the anti-inflammatory effects of other potential catechins in green tea.

Management of pain in the treatment of rheumatoid arthritis (RA) is a priority that is not fully addressed by the conventional therapies. In the present study, we evaluated the efficacy of cannabinoid receptor 2 (CB2) agonist JWH-015 using RA synovial fibroblasts (RASFs) obtained from patients diagnosed with RA and in a rat adjuvant-induced arthritis (AIA) model of RA. Pretreatment of human RASFs with JWH-015 (10–20 μM) markedly inhibited the ability of pro-inflammatory cytokine interleukin-1β (IL-1β) to induce production of IL-6 and IL-8 and cellular expression of inflammatory cyclooxygenase-2 (COX-2). JWH-015 was effective in reducing IL-1β-induced phosphorylation of TAK1 (Thr 184/187 ) and JNK/SAPK in human RASFs. While the knockdown of CB2 in RASFs using siRNA method reduced IL-1β-induced inflammation, JWH-015 was still effective in eliciting its anti-inflammatory effects despite the absence of CB2, suggesting the role of non-canonical or an off-target receptor. Computational studies using molecular docking and molecular dynamics simulations showed that JWH-105 favorably binds to glucocorticoid receptor (GR) with the binding pose and interactions similar to its well-known ligand dexamethasone. Furthermore, knockdown of GR using siRNA abrogated JWH-015's ability to reduce IL-1β-induced IL-6 and IL-8 production. In vivo , administration of JWH-015 (5 mg/kg, daily i.p. for 7 days at the onset of arthritis) significantly ameliorated AIA in rats. Pain assessment studies using von Frey method showed a marked antinociception in AIA rats treated with JWH-015. In addition, JWH-015 treatment inhibited bone destruction as evident from micro-CT scanning and bone analysis on the harvested joints and modulated serum RANKL and OPG levels. Overall, our findings suggest that CB2 agonist JWH-015 elicits anti-inflammatory effects partly through GR. This compound could further be tested as an adjunct therapy for the management of pain and tissue destruction as a non-opioid for RA.

Transforming growth factor β (TGF-β) is a multifunctional cytokine that is synthesized by many types of cells and regulates the cell cycle. Increasing evidence has led to TGF-β receiving increased and deserved attention in recent years because it may play a potentially novel and critical role in the development and progression of myocardial fibrosis and the subsequent progress of ventricular remodeling (VR). Numerous studies have highlighted a crucial role of TGF-β in VR and suggest potential therapeutic targets of the TGF-β signaling pathways for VR. Changes in TGF-β activity may elicit anti-VR activity and may serve as a novel therapeutic target for VR therapy. This review we discusses the smad-dependent signaling pathway, such as TGF-β/Smads, TGF-β/Sirtuins, TGF-β/BMP, TGF-β/miRNAs, TGF-β/MAPK, and Smad-independent signaling pathway of TGF-β, such as TGF-β/PI3K/Akt, TGF-β/ Rho/ROCK,TGF-β/Wnt/β-catenin in the cardiac fibrosis and subsequent progression of VR. Furthermore, agonists and antagonists of TGF-β as potential therapeutic targets in VR are also described.

The IL‐1 cytokines are considered among the first family of cytokines that orchestrate acute and chronic inflammatory diseases. Both IL‐1β and IL‐1α are members of the IL‐1 family; however, their distinct roles in the inflammatory processes remain poorly understood. We explored the role of IL‐1α in IL‐1β‐activated signaling pathways causing synovial inflammation in rheumatoid arthritis (RA). Using synovial fibroblasts isolated from RA joints, we found that IL‐1β significantly stimulated IL‐1α expression, which was selectively inhibited by blocking the NF‐κB pathway. Knockdown of IL‐1α using small interfering RNA abolished IL‐1β‐induced pro‐IL‐1α and pro‐IL‐1β expression and suppressed inflammation. Native and chromatin immunoprecipitation studies showed that IL‐1α cooperates in NF‐κBp65 binding to the distal region of IL‐1α promoter and to the proximal region of IL‐1β promoter upstream of the transcription start site to stabilize their gene transcription. Molecular dynamics simulation of IL‐1α or IL‐1β binding to IL‐1 receptor showed distinct interaction sites that corroborate with the ability of IL‐1α to differentially activate phosphorylation of signaling proteins compared with IL‐1β. Our study highlights the importance of IL‐1α in mediating IL‐1β–induced inflammation in addition to maintaining its expression and providing a rationale for targeting IL‐1α to minimize the role of IL‐1β in inflammatory diseases like RA.—Singh, A. K., Fechtner, S., Chourasia, M., Sicalo, J., Ahmed, S. Critical role of IL‐1α in IL‐1β–induced inflammatory responses: cooperation with NF‐κBp65 in transcriptional regulation. FASEB J. 33, 2526–2536 (2019). http://www.fasebj.org

Objective Patients with established rheumatoid arthritis (RA) demonstrate altered immune responses to Epstein‐Barr virus (EBV), but the presence and roles of EBV have not been fully explored during the pre–clinical disease period. This study was undertaken to determine if EBV infection, as evidenced by an altered anti‐EBV antibody response, either plays an important role in driving the development of RA or is a result of expanded RA‐related autoimmunity. Methods A total of 83 subjects with RA according to the 1987 American College of Rheumatology (ACR) criteria and 83 age‐, sex‐, and race‐matched control subjects without RA were included in our study. We collected sera from RA subjects and matched controls during the pre–RA and post–RA diagnosis periods and tested the sera for the presence of 5 anti‐EBV antibodies (anti–EBV nuclear antigen 1 IgG isotype, anti–viral capsid antigen [anti‐VCA] isotypes IgG and IgA, and anti–early antigen [EA] isotypes IgG and IgA), 7 RA‐related autoantibodies (rheumatoid factor measured by nephelometry [RF‐Neph] as well as isotype‐specific IgA‐RF, IgM‐RF, and IgG‐RF, and anti–cyclic citrullinated peptide [anti‐CCP] antibodies, including anti‐CCP2, anti‐CCP3, and anti‐CCP3.1), 22 cytokines/chemokines, 36 individual anti–citrullinated protein antibodies, and IgG–cytomegalovirus (CMV) antibodies. Random forest classification, mixed modeling, and joint mixed modeling were used to determine differences in anti‐EBV antibody levels between RA subjects and controls. Results Random forest analysis identified the presence of preclinical EBV antibodies in the serum that differentiated RA subjects from controls without RA. Specifically, IgG‐EA antibody levels were higher in RA subjects (mean ± SD 0.82 ± 0.72 international standardized ratio [ISR]) compared to controls (mean ± SD 0.49 ± 0.28 ISR). In subjects with RA, elevated serum IgG‐EA levels in the preclinical period before seroconversion were significantly correlated with increased serum IgM‐RF levels (P = 0.007), whereas this correlation was not seen in control subjects without RA (P = 0.15). IgG‐CMV antibody levels did not differ between groups. Conclusion Subjects whose serum IgG‐EA antibody levels are elevated in the preclinical period will eventually develop RA, which suggests that EBV reactivation cycles are increased during the preclinical period of RA. A combination of RF and EBV reactivation may play an important role in the development of RA.