Micro RNAs 26b, 20a inversely correlate with GSK-3 ß/NF-κB/NLRP-3 pathway to highlight the additive promising effects of atorvastatin and quercetin in experimental induced arthritis.

Rheumatoid arthritis (RA) is an inflammatory disease with challenging therapeutic potential due to the implication of cross-talking intracellular pathways in the pathogenesis of the disease. This study aimed to evaluate the effects of the combination therapy of atorvastatin and quercetin on glycogen synthase kinase-3 beta/ nuclear factor kappa-B/ nucleotide-binding oligomerization domain-like receptor family pyrin domain containing-3 or inflammasome (GSK-3ß/NF-KB/NLRP-3) pathway as well as on microRNAs 26b and 20a (miR-26b, miR-20a) and to investigate the possible beneficial outcomes of the combination to offer a better treatment option than methotrexate (MTX) in adjuvant-induced arthritis (AIA). Assessment of arthritis progression, serum inflammatory, and oxidative parameters were done. The tibiotarsal tissue expression of the inflammatory parameters was evaluated. Western blot analysis was done to assess the expression level of the important members in the GSK-3ß/NF-κB/NLRP-3 pathway. Furthermore, the expression level of both microRNAs and serum level of transaminases were determined. All treatments, especially the combination regimen, abated arthritis progression, the elevated serum level of inflammatory and oxidative stress parameters in arthritic rats. Moreover, They down-regulated the gene expression of the important members of the aforementioned signaling pathway, amended the tissue levels of inflammatory parameters and elevated the expression level of miR-26b and miR-20a. Finally, we concluded that the combination therapy modulated miR-26b and miR-20a as well as GSK-3ß/NF-κB/NLRP-3 pathway, provided additive anti-inflammatory and anti-oxidant effects and offered an additional hepatoprotective effect as compared to untreated arthritic rats and MTX-treated groups, suggesting its promising role to be used as replacement therapy to MTX in RA.

Metformin and omega-3 fish oil elicit anti-inflammatory effects via modulation of some dysregulated micro RNAs expression and signaling pathways in experimental induced arthritis.

OBJECTIVE: Rheumatoid arthritis is a progressive inflammatory disease with multiple dysfunctional intracellular signaling pathways that necessitate new approaches for its management. Hence, the study aimed to inspect the ability of the combination therapy of metformin and omega-3 to modulate different signaling pathways and micro RNAs such as (miR-155, miR-146a and miR-34) as new targets in order to mitigate adjuvant-induced arthritis and compare their effect to that of methotrexate. METHODS: Fourteen days post adjuvant injection, Sprague-Dawley rats were treated orally with metformin (200 mg/kg/day) and/or omega-3 (300 mg/kg/day) or intraperitoneally with methotrexate (2 mg/kg/week) for 4 weeks. RESULTS AND CONCLUSION: All drug treatments amended the arthrogram score and hind paw swelling as well as decreased serum tumor necrosis factor (TNF)-α and interleukin (IL)-1ß levels. On the molecular level, all therapies activated phospho-5'adenosine monophosphate-activated protein kinase (p-AMPK) and protein phosphatase 2A (PP2A), while they inhibited phospho-mammalian target of rapamycin (p-mTOR), phospho-signal transducers and activators of transcription (p-STAT3), nuclear factor (NF)-κB p65 subunit, phosho38 mitogen-activated protein kinase (p38 MAPK) and phospho- c-Jun N-terminal kinase (p-JNK). In addition, they decreased the elevated expression level of miRNA-155, 146a and increased the expression level of miRNA-34 and they decreased the expression level of retinoic acid receptor related orphan receptor γT (RORγT) and increased that of fork head box P3 (FOXP3), correcting Th17/Treg cells balance. On most of the aforementioned parameters, the effect of the combination therapy was comparable to that of methotrexate, emphasizing that this combination possesses better additive anti-inflammatory effect than either drug when used alone. In addition, the combination was capable of normalizing the serum transaminases levels as compared to untreated group offering hepatoprotective effect and suggesting the possibility of its use as a replacement therapeutic strategy for MTX in rheumatoid arthritis.