Adjuvant-induced Arthritis In Rats Research Articles

Design and optimization of a series of 4-(3-azabicyclo[3.1.0]hexan-3-yl)pyrimidin-2-amines: Dual inhibitors of TYK2 and JAK1

Herein, we disclose a new series of TYK2/ JAK1 inhibitors based upon a 3.1.0 azabicyclic substituted pyrimidine scaffold. We illustrate the use of structure-based drug design for the initial design and subsequent optimization of this series of compounds. One advanced example 19 met program objectives for potency, selectivity and ADME, and demonstrated oral activity in the adjuvant-induced arthritis rat model.

Dexmedetomidine inhibits the invasion, migration, and inflammation of rheumatoid arthritis fibroblast-like synoviocytes by reducing the expression of NLRC5

Rheumatoid arthritis (RA) is a chronic, autoimmune disease characterized by inflammatory synovitis, but its pathogenesis remains unclear. NLRC5 is a newly discovered member of the NLR family that is effective in regulating autoimmunity, inflammatory responses, and cell death processes. Dexmedetomidine (DEX) has been reported to have a variety of pharmacological effects, including anti-inflammatory and analgesic effects. However, the role of DEX in RA has not been explored. In adjuvant-induced arthritis (AA) rat models, DEX (10 μg/kg and 20 μg/kg) reduced the pathological score, the arthritis score, paw swelling volume, and the serum levels of IL-1β, IL-6, IL-17A, and TNF-α. Moreover, by using Western blot and real-time quantitative PCR (RT-qPCR), it was demonstrated that DEX can inhibit the expression of IL-1β, IL-6, MMP-3, MMP-9 and P-P65 in the synovial tissue of AA rats. In human rheumatoid arthritis fibroblast-like synoviocytes (RA-FLSs), DEX (250 nM and 500 nM) was found to inhibit the expression of IL-1β, IL-6, MMP-3, MMP-9, and P-P65 following stimulation with TNF-α. Moreover, DEX can inhibit the invasion and migration of RA-FLSs stimulated by TNF-α. Finally, the expression of NLRC5 in RA-FLSs and AA rat models was also reduced by DEX. After silencing NLRC5 in RA-FLSs, the expression of IL-1β, IL-6, MMP-3, MMP-9, and P-P65, as well as the invasion and migration of cells, were significantly reduced. These results indicate that DEX inhibits the invasion, migration, and inflammation of RA-FLSs by reducing the expression of NLRC5 and inhibiting the NF-κB activation.

Novel paeonol derivatives: Design, synthesis and anti-inflammatory activity in vitro and in vivo

Paeonol has been proved to have potential anti-inflammatory activity, but its clinical application is not extensive due to the poor anti-inflammatory activity (14.74% inhibitory activity at 20μM). In order to discover novel lead compound with high anti-inflammatory activity, series of paeonol derivatives were designed and synthesized, their anti-inflammatory activities were screened in vitro and in vivo. Structure-activity relationships (SARs) have been fully concluded, and finally (E)-N-(4-(2-acetyl-5-methoxyphenoxy)phenyl)-3-(3,4,5-trimet-hoxyphenyl)acrylamide (compound 11a) was found to be the best active compound with low toxicity, which showed 96.32% inhibitory activity at 20μM and IC50 value of 6.96μM against LPS-induced over expression of nitric oxide (NO) in RAW 264.7 macrophages. Preliminary mechanism studies indicated that it could inhibit the expression of TLR4, resulting in inhibiting of NF-κB and MAPK pathways. Further studies have shown that compound 11a has obvious therapeutic effect against the adjuvant-induced rat arthritis model.

Novel 1H-pyrazolo[3,4-d]pyrimidin-6-amino derivatives as potent selective Janus kinase 3 (JAK3) inhibitors. Evaluation of their improved effect for the treatment of rheumatoid arthritis.

Selective JAK3 inhibitors have been shown to have a potential benefit in the treatment of autoimmune disorders. Here we report the identification of a series of pyrazolopyrimidine derivatives as potent JAK3 inhibitors that exploit a unique cysteine (Cys909) residue in JAK3. Most of these compounds (13k, 13n and 13t), displayed stronger anti-JAK3 kinase activity and selectivity than tofacitinib. Furthermore, the most active inhibitor 13t (IC50=0.1nM), also exhibited favourable selectivity for JAK3 in a panel of 9 kinases which contain the same cysteine. In a series of cytokinestimulated cellular analysis, compound 13t, could potently block the JAK3-STAT signaling pathway. Further biological studies, including cellular antiproliferative activity assays and a rat adjuvant-induced arthritis model for in vivo evaluation, also indicated its efficacy and low toxicity in the treatment of rheumatoid arthritis. The results of these experimental explorations suggested that 13t is a promising lead compound for the development of selective JAK3 inhibitor with therapeutic potential in rheumatoid arthritis.

Berberine encapsulated PEG-coated liposomes attenuate Wnt1/β-catenin signaling in rheumatoid arthritis via miR-23a activation

Bone erosion is a debilitating pathological process of osteopathic disorder like rheumatoid arthritis (RA). Current treatment strategies render low disease activity but with disease recurrence. To find an alternative, we designed this study with an aim to explore the underlying therapeutic effect of PEGylated liposomal BBR (PEG-BBR) against Wnt1/β-catenin mediated bone erosion in adjuvant-induced arthritic (AA) rat model and fibroblast-like synoviocytes (FLS) with reference to microRNA-23a (miR-23a) activity. Our initial studies using confocal microscopy and Near-Infrared Imaging (NIR) showed successful internalization of PEG-BBR and PEG-miR-23a in vitro and in vivo respectively and was retained till 48 h. The preferential internalization of PEG-BBR into the inflamed joint region significantly reduced the gene and protein level expression of major Wnt1 signaling mediators and reduced bone erosion in rats. Moreover, PEG-BBR treatment in FLS cells attenuated the gene and protein expression levels of FZD4, LRP5, β-catenin, and Dvl-1 through the induction of CYLD. Furthermore, inhibition of these factors resulted in reduced bone loss and increased calcium retainability by altering the RANKL/OPG axis. PEG-BBR treatment markedly inhibited the expression of LRP5 protein on par with the DKK-1 (LRP5/Wnt signaling inhibitor) and suppressed the transcriptional activation of β-catenin inside the cells. We further witnessed that miR-23a altered the expression levels of LRP5 through RNA interference. Overall, our findings endorsed that miR-23a possesses a multifaceted therapeutic efficiency like berberine in RA pathogenesis and can be considered as a potential candidate for therapeutic targeting of Wnt1/β-catenin signaling in RA disease condition.

Evodiamine attenuates adjuvant-induced arthritis in rats by inhibiting synovial inflammation and restoring the Th17/Treg balance.

Evodiamine (Evo) possesses strong anti-inflammatory activity. In this study, we determine the antiarthritic effect of Evo. Evo was administered to rats with adjuvant-induced arthritis (AA). We evaluated arthritis symptoms & histopathological changes and measured inflammatory cell infiltration, pro-inflammatory cytokine production and Th17 & Treg percentages in arthritic rats. Evo significantly improved the clinical signs of AA in rats, including decreases in paw swelling, the polyarthritis index and the number of swollen paw joints. Based on the histopathological analysis, Evo improved synovial inflammation and bone injury by inhibiting inflammatory cell infiltration, synoviocyte proliferation, pannus formation and cartilage erosion. Furthermore, the numbers of synovial CD3+ or CD68+ inflammatory cells were reduced, and the elevated levels of tumour necrosis factor-α, interleukin-1β (IL-1β) and IL-6 were restored to control levels by the Evo treatment. In addition, Evo therapy regulated the abnormal differentiation of Treg and Th17 cells, decreasing IL-17 production and increasing IL-10 levels. Finally, Evo inhibited Stat3 phosphorylation and induced Stat5 phosphorylation in rats with AA. Based on our results, Evo is a promising antiarthritic agent, potentially due to its inhibitory effect on synovial inflammation and regulatory effects on Treg and Th17 differentiation.

Antiarthritic effect of chitosan nanoparticle loaded with embelin against adjuvant‐induced arthritis in Wistar rats

Rheumatoid arthritis (RA) is associated with joint damage. Effectiveness of embelin has been established in a wide variety of inflammatory disorders, but its utility as a therapeutic agent is limited by its poor absorption, rapid metabolism, and fast systemic elimination. To apprehend these limitations, we propose to use highly bioavailable embelin-loaded chitosan nanoparticles (CS-embelin NPs) for the treatment of RA. The rats were made arthritic using a subcutaneous injection with 0.1 ml complete Freund's adjuvant (CFA) into the footpad of the left hind paw. CS-embelin NPs (25 and 50 mg/kg) was administered from day 15 to day 28 after adjuvant injection. After the experimental period, the animals were sacrificed and various biochemical markers were assessed. Arthritic score and paw swelling were significantly reduced after treatment with CS-embelin NPs. Arthritis-induced rats showed a significant increase in malondialdehyde (MDA) and nitric oxide (NO) with a concomitant reduction of antioxidants in the paw tissue. CS-embelin NPs (25 and 50 mg/kg) reduced MDA and NO levels and restored antioxidant levels to normalcy by mitigating oxidative stress. The arthritic rats exhibited elevated tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1beta (IL-1β) serum concentrations, upregulated TNF- α and IL-6 protein levels and upregulated nuclear factor-kB (NF-kB) mRNA expression in paw tissues. Treatment with CS-embelin NPs (25 and 50 mg/kg) significantly reduced serum levels and down-regulated inflammatory markers to normalcy, dose-dependently. The results suggest that CS-embelin NPs displayed a protective effect against adjuvant-induced arthritis in rats mediated through antioxidant and anti-inflammatory effects.

Cyanidin prevents the hyperproliferative potential of fibroblast-like synoviocytes and disease progression via targeting IL-17A cytokine signalling in rheumatoid arthritis

The hyperplastic phenotype of fibroblast-like synoviocytes (FLSs) plays an important role for synovitis, chronic inflammation and joint destruction in rheumatoid arthritis (RA). Interleukin 17A (IL-17A), a signature pro-inflammatory cytokine effectively influences the hyperplastic transformation of FLS cells and synovial pannus growth. IL-17A cytokine signalling participates in RA pathology by regulating an array of pro-inflammatory mediators and osteoclastogenesis. Cyanidin, a key flavonoid inhibits IL-17A/IL-17 receptor A (IL-17RA) interaction and alleviates progression and disease severity of psoriasis and asthma. However, the therapeutic efficacy of cyanidin on IL-17A cytokine signalling in RA remains unknown. In the present study, cyanidin inhibited IL-17A induced migratory and proliferative capacity of FLS cells derived from adjuvant-induced arthritis (AA) rats. Cyanidin treatment reduced IL-17A mediated reprogramming of AA-FLS cells to overexpress IL-17RA. In addition, significantly decreased expression of IL-17A dependent cyr61, IL-23, GM-CSF, and TLR3 were observed in AA-FLS cells in response to cyanidin. At the molecular level, cyanidin modulated IL-17/IL-17RA dependent JAK/STAT-3 signalling in AA-FLS cells. Importantly, cyanidin activated PIAS3 protein to suppress STAT-3 specific transcriptional activation in AA-FLS cells. Cyanidin treatment to AA rats attenuated clinical symptoms, synovial pannus growth, immune cell infiltration, and bone erosion. Cyanidin reduced serum level of IL-23 and GM-CSF and expression of Cyr 61 and TLR3 in the synovial tissue of AA rats. Notably, the level of p-STAT-3 protein was significantly decreased in the synovial tissue of AA rats treated with cyanidin. This study provides the first evidence that cyanidin can be used as IL-17/17RA signalling targeting therapeutic drug for the treatment of RA and this need to be investigated in RA patients.

Investigation of toll-like receptor (TLR) 4 inhibitor TAK-242 as a new potential anti-rheumatoid arthritis drug

BackgroundProper blocking of toll-like receptor (TLR) activation during disease progression has been reported to have inhibitory effect on the pathogenesis of rheumatoid arthritis (RA). We tested whether the TLR4 inhibitor TAK-242 had potential as a remedy for rheumatoid arthritis.MethodsThe therapeutic effect of TAK-242 was tested in vitro using the human rheumatoid fibroblast-like synoviocyte (FLS) line MH7A or primary human FLS and in an adjuvant-induced arthritis (AIA) rat model.ResultsTAK-242 dose dependently inhibited the increased expression of IL-6, IL-8, MMP-1, and VEGF in LPS-stimulated MH7A cells. It also inhibited the expression of IL-6 and IL-8 in poly(I:C), TLR3 activator-stimulated primary FLS, but not in IL-1β-stimulated primary FLS. These findings suggest that TAK-242 blocks a specific signaling pathway to some degree. Further, TAK-242 slightly inhibited mobilization of NF-κB into nuclei. In the AIA rat model, TAK-242 significantly reversed the body weight and paw thickness of AIA rats to the normal state at a dose of 5 mg/kg, but not at 3 mg/kg, and reduced the increased serum level of IL-6 and VEGF in AIA rats. It also significantly ameliorated inflammatory symptoms of joint tissues at day 21 of treatment, according to histology and RT-PCR.ConclusionsBased on the drug repositioning concept, TAK-242, which is used for the treatment of TLR4-mediated inflammatory diseases, shows potential for cost-effective development as a remedy for rheumatoid arthritis or to control the progression of RA.

Crocin Alleviates Pain Hyperalgesia in AIA Rats by Inhibiting the Spinal Wnt5a/β-Catenin Signaling Pathway and Glial Activation.

At present, most of the drugs have little effect on the pathological process of rheumatoid arthritis (RA). Analgesia is an important measure in the treatment of RA and is also one of the criteria to determine the therapeutic effects of the disease. Some studies have found that crocin, a kind of Chinese medicine, can effectively alleviate pain sensitization in pain model rats, but the mechanism is not clear. Emerging evidence indicates that crocin may inhibit the metastasis of lung and liver cancer cells from the breast by inhibiting Wnt/β-catenin and the Wnt signaling pathway is closely related to RA. Wnt5a belongs to the Wnt protein family and was previously thought to be involved only in nonclassical Wnt signaling pathways. Recent studies have shown that Wnt5a has both stimulatory and inhibitory effects on the classical Wnt signaling pathway, and so, Wnt5a has attracted increasing attention. This study demonstrated that crocin significantly increased the mechanical thresholds of adjuvant-induced arthritis (AIA) rats, suggesting that crocin can alleviate neuropathic pain. Crocin significantly decreased the levels of pain-related factors and glial activation. Foxy5, activator of Wnt5a, inhibited the above effects of crocin in AIA rats. In addition, intrathecal injection of a Wnt5a inhibitor significantly decreased hyperalgesia in AIA rats. This research shows that crocin may alleviate neuropathic pain in AIA rats by inhibiting the expression of pain-related molecules through the Wnt5a/β-catenin pathway, elucidating the mechanism by which crocin relieves neuropathic pain and provides a new way of thinking for the treatment of AIA pain.

Combination therapy of ginsenoside compound K and methotrexate was efficient in elimination of anaemia and reduction of disease activity in adjuvant-induced arthritis rats

Context Ginsenoside compound K (CK) has anti-inflammatory, immunoregulatory, and myelosuppressive protective effects. Methotrexate (MTX) is widely used in combination therapy for rheumatoid arthritis (RA). Objective To evaluate the effects of combination therapy of CK and MTX on anaemia and anti-arthritis in adjuvant-induced arthritis (AA) rats. Materials and methods AA was induced in rats by Complete Freund’s adjuvant, and divided into five groups (n = 10): normal, AA, CK 80 mg/kg, combination therapy (80 mg/kg CK combined with 0.5 mg/kg MTX), and MTX 0.5 mg/kg. From day 12, CK (once a day for 15 days) or MTX (once every 3 days, five times) were intragastrically administered. Results Combination therapy showed increased haemoglobin to 148.5 ± 10.1 g/L compared with AA (129.8 ± 11.7 g/L) and MTX (128.8 ± 18.4 g/L), and decreased reticulocytes in peripheral blood to 4.9 ± 1.1% compared with MTX (9.3 ± 3.3%). In combination therapy group, paw swelling decreased to 5.6 ± 4.3 mL compared with CK (9.4 ± 3.9 mL) and MTX (13.5 ± 7.4 mL), and swollen joint count decreased to 1.4 ± 0.8 compared with CK (2.1 ± 1.0) and MTX (2.4 ± 1.2) at day 24. Combination therapy showed decreased IL-6 to 25.1 ± 17.2 pg/mL compared with MTX (44.9 ± 4.8 pg/mL), and decreased IL-17 to 5.8 ± 3.9 pg/mL compared with MTX (10.7 ± 4.2 pg/mL). Conclusion The anti-anaemia effect of CK deserves further study, and CK can be a candidate effective drug for combined treatment in RA with anaemia.

Er Miao San, a traditional Chinese herbal formula, attenuates complete Freund’s adjuvant-induced arthritis in rats by regulating Th17/Treg cells

Context Er Miao San (EMS) is a traditional Chinese medicine composed of Atractylodis Rhizoma and Phellodendri Cortex in a 1:1 weight ratio. EMS has been used to treat rheumatism in China for many years. Objective To evaluate the anti-arthritic activity of EMS extract on adjuvant-induced arthritis (AA) in Sprague-Dawley rats and to clarify its mechanisms of action. Materials and methods EMS (0.75, 1.5 and 3 g/kg, once daily) was orally administered from day 18 after immunization to day 31. The effects of EMS on AA rats were evaluated by histopathological examination, paw swelling and polyarthritis index. The proliferation of fibroblast-like synoviocyte (FLS) and T cells was detected by CCK-8. The percentages of Th17 cells and Treg cells in splenocytes were determined by flow cytometry. Levels of cytokines in serum were detected by ELISA. Results EMS treatment significantly decreased the paw volume (from 1.20 to 0.81), polyarthritis index (from 9.56 to 4.46) and alleviated ankle joint histopathology in AA rats. EMS inhibited the proliferation of FLS and T cells. Furthermore, EMS treatment decreased Th17 cells (from 4.62 to 2.08%) and increased Treg cells (from 2.77 to 4.75%) in splenocytes. The levels of IL-17A, TNF-α and IL-6 were remarkably decreased in the serum of EMS-treated rats, whereas the levels of IL-10 and TGF-β1 were significantly increased. Conclusions EMS exhibits anti-arthritic activity in the AA model by regulating the balance of cytokines and the ratio of Th17 and Treg cells. These insights may provide an experimental basis for the clinical treatment of RA.

Anti-inflammatory effects of the root, stem and leaf extracts of Chloranthus serratus on adjuvant-induced arthritis in rats

Context Chloranthus serratus [(Thunb.) Roem. et Schult, (Chloranthaceae)] is a folk medicine used for the treatment of rheumatoid arthritis. Objective The aim of this study was to investigate anti-arthritic effects of the ethanol extracts of the roots (ER), stems (ES) and leaves (EL) of C. serratus on adjuvant arthritis rats and related mechanisms. Materials and methods The rats were immunized by intradermal injection of complete Freund’s adjuvant (CFA, 0.18 mL) into the right hind feet, and received intragastric administrations of the ER, ES and EL (2.07, 1.61 and 0.58 g/kg/d, respectively) for 14 days. The anti-arthritic activity was assessed by swelling rates, serum indicators, antioxidant capacity, histopathological and immunohistochemical analyses. Results The LD50 of the ER, ES and EL was higher than 10.35, 8.05 and 2.90 g/kg/p.o., respectively. Extract treatments decreased swelling rates, tumour necrosis factor-alpha (TNF-α), vascular endothelial growth factor (VEGF), interleukin 1 beta (IL-1β), migration inhibitory factor 1 (MIF-1), immunoglobulin G (IgG) and immunoglobulin M (IgM) levels and positive expression of VEGF in the arthritic rats (p < 0.01 or p < 0.05). The ER significantly decreased NO (3.91 ± 0.61 µmol/L), IL-6 (75.67 ± 16.83 pg/mL) and malondialdehyde (MDA) (2.28 ± 0.32 nmol/mL) contents and clearly increased IFN-γ (2082 ± 220.93 pg/mL) and superoxide dismutase (SOD) (601.98 ± 38.40 U/mL) levels. The ES and EL did not reverse the changes in some indicators. All the extracts alleviated inflammatory cell infiltration and synovial cell proliferation. Among them, the ER was the most pronounced. Discussion and conclusions ER exerts the most promising effects, as shown by inhibiting the releases of inflammatory cytokines and enhancing antioxidant capacity, which provides a scientific basis for further research on C. serratus and its clinical applications.

β-Sitosterol-loaded solid lipid nanoparticles ameliorate complete Freund’s adjuvant-induced arthritis in rats: involvement of NF-кB and HO-1/Nrf-2 pathway

Rheumatoid arthritis (RA), autoimmune disease that is categorized via chronic inflammation manifestation, obesity, cardiovascular risk and even enhanced the mortality and affect the 0.3 and 1% of population worldwide. The current experimental study was scrutinize the anti-arthritic effect of β-sitosterol loaded solid lipid nanoparticles (SLN) against complete Fruend adjuvant (CFA)-induced arthritis via dual pathway. Double emulsion solvent displacement method was used for the preparation of β-sitosterol solid lipid nanoparticles (SLN). CFA was used to induce arthritis and rats were divided into different groups for 28 days. Biochemical, anti-inflammatory, pro-inflammatory cytokines and inflammatory mediator were estimated, respectively. Receptor activator of nuclear factor kappa-B ligand (RANKL), signal transducer and activator of transcription-3 (STAT3) nuclear factor erythroid 2–related factor 2 (Nrf2), Heme Oxygenase-1(HO-1) and Nuclear factor-κB (NF-κB) expression were estimated. β-sitosterol-SLN significantly (p < .001) reduced the paw edema, arthritic index and increased the body weight. β-sitosterol-SLN increased the redox status of synovium {reduce the malonaldehyde (MDA) and increase superoxide dismutase (SOD), glutathione (GSH) and catalase (CAT)} level and reduced the cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-2, interleukin-6, interleukin-16, interleukin-17 and increased level of interleukin-10, Transforming growth factor beta (TGF-β). β-sitosterol-SLN significantly (p < .001) reduced the level of cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), vascular Endothelial Growth Factor (VEGF) and NF-κB. β-sitosterol-SLN significantly increased the expression of HO-1,Nrf2 and decreased the expression of NF-κB, RANKL, STAT3. In conclusion, β-sitosterol SLN showed the antiarthritic effect via suppression of NF-kB and activation of HO-1/Nrf-2 pathway.

Rheumatoid pain models in rodents and the application of dynamic weight-bearing test

Rheumatoid arthritis (RA) is an autoimmune systemic disease of unknown etiology, characterized by chronic inflammation and synovial infiltration of immune cells. Pain is one of the most dominant symptoms for patients with RA, which affects the health and quality of life. Animal models are helpful to study the pathogenesis of RA and related factors and mechanisms of RA-induced pain, which may aid in the development of new and better treatment strategies. Several animal models of RA have been validated to predict for efficacy in humans that include collagen type II-induced arthritis in rats and mice, adjuvant-induced arthritis in rats, and antigen induced arthritis in several species. However, the quantitative evaluation of pain in animal models is technically challenging. Until recent years, behavior methods are used to characterize acute and chronic pain stages by observing behavioral changes in preclinical arthritis models. Significant progress has been made in pain assessment with the development of nonreflexive tools, dynamic weight-bearing (DWB) apparatus was developed for the measurement of pain in rodents by capturing weight-bearing and surface distribution of the paws. In this article, we summarize several classical animal models of rheumatoid pain as well as discussion of the advantages and disadvantages of DWB test for spontaneous pain used in these models.

T-96 attenuates inflammation by inhibiting NF-κB in adjuvant-induced arthritis.

The extract of the medicinal plant, Tripterygium wilfordii Hook. f. (TW), has been used in the treatment of diverse autoimmune diseases, including rheumatoid arthritis. However, the high frequency of toxic side effects has limited its clinical use. In order to reduce toxicity without losing the therapeutic benefit, the pharmacological activity and toxicity of four compounds (T-96, triptolide, neotripterifordin, and tripterifordin) from TW were evaluated. The current study revealed that these compounds interfere with the IL-1β signaling pathway, which stimulates the secretion of pro-inflammatory cytokines (IL-6) in primary rheumatoid arthritis synovial fibroblasts (RASFs). These compounds inhibit IL-6 production, and among these, T-96 was the most effective. Moreover, T-96 blocks activation of NF-kappa B and p38 and ameliorates the joint destruction and the clinical signs of the disease in adjuvant-induced arthritic rats. These data suggest that among the four compounds of the TW, T-96 possesses highest anti-rheumatoid arthritis activity though inhibiting IL-1-mediated inflammatory signaling pathways.

Dow, Evonik bring new method for direct synthesis of propylene glycol

Bone erosion is a debilitating pathological process of osteopathic disorder like rheumatoid arthritis (RA). Current treatment strategies render low disease activity but with disease recurrence. To find an alternative, we designed this study with an aim to explore the underlying therapeutic effect of PEGylated liposomal BBR (PEG-BBR) against Wnt1/β-catenin mediated bone erosion in adjuvant-induced arthritic (AA) rat model and fibroblast-like synoviocytes (FLS) with reference to microRNA-23a (miR-23a) activity. Our initial studies using confocal microscopy and Near-Infrared Imaging (NIR) showed successful internalization of PEG-BBR and PEG-miR-23a in vitro and in vivo respectively and was retained till 48 h. The preferential internalization of PEG-BBR into the inflamed joint region significantly reduced the gene and protein level expression of major Wnt1 signaling mediators and reduced bone erosion in rats. Moreover, PEG-BBR treatment in FLS cells attenuated the gene and protein expression levels of FZD4, LRP5, β-catenin, and Dvl-1 through the induction of CYLD. Furthermore, inhibition of these factors resulted in reduced bone loss and increased calcium retainability by altering the RANKL/OPG axis. PEG-BBR treatment markedly inhibited the expression of LRP5 protein on par with the DKK-1 (LRP5/Wnt signaling inhibitor) and suppressed the transcriptional activation of β-catenin inside the cells. We further witnessed that miR-23a altered the expression levels of LRP5 through RNA interference. Overall, our findings endorsed that miR-23a possesses a multifaceted therapeutic efficiency like berberine in RA pathogenesis and can be considered as a potential candidate for therapeutic targeting of Wnt1/β-catenin signaling in RA disease condition.

ASIC1a induces synovial inflammation via the Ca2+/NFATc3/ RANTES pathway.

Rationale: Synovial inflammation is one of the main pathological features of rheumatoid arthritis (RA) and is a key factor leading to the progression of RA. Understanding the regulatory mechanism of synovial inflammation is crucial for the treatment of RA. Acid-sensing ion channel 1a (ASIC1a) is an H+-gated cation channel that promotes the progression of RA, but the role of ASIC1a in synovial inflammation is unclear. This study aimed to investigate whether ASIC1a is involved in the synovial inflammation and explore the underlying mechanisms in vitro and in vivo.Methods: The expression of ASIC1a and nuclear factor of activated T cells (NFATs) were analyzed by Western blotting, immunofluorescence, and immunohistochemistry both in vitro and in vivo. The Ca2+ influx mediated by ASIC1a was detected by calcium imaging and flow cytometry. The role of ASIC1a in inflammation was studied in rats with adjuvant-induced arthritis (AA). Inflammatory cytokine profile was analyzed by protein chip in RA synovial fibroblasts (RASF) and verified by a magnetic multi-cytokine assay and ELISA. The NFATc3-regulated RANTES (Regulated upon activation, normal T cell expressed and secreted) gene transcription was investigated by ChIP-qPCR and dual-luciferase reporter assay.Results: The expression of ASIC1a was significantly increased in human RA synovial tissues and primary human RASF as well as in ankle synovium of AA rats. Activated ASIC1a mediated Ca2+ influx to increase [Ca2+]i in RASF. The activation/overexpression of ASIC1a in RASF up-regulated the expression of inflammatory cytokines RANTES, sTNF RI, MIP-1a, IL-8, sTNF RII, and ICAM-1 among which RANTES was increased most remarkably. In vivo, ASIC1a promoted inflammation, synovial hyperplasia, articular cartilage, and bone destruction, leading to the progression of AA. Furthermore, activation of ASIC1a upregulated the nuclear translocation of NFATc3, which bound to RANTES promoter and directly regulated gene transcription to enhance RANTES expression.Conclusion: ASIC1a induces synovial inflammation, which leads to the progression of RA. Our study reveals a novel RA inflammation regulatory mechanism and indicates that ASIC1a might be a potential therapeutic target for RA.

Fisetin Attenuates Cartilage Destruction in Adjuvant-Induced Arthritis by Modulating Cartilage Cytokine Expression Correlated with Oxidative Status in the Early Phase in Experimental Animals

The present study was designed to evaluate the effect of Fisetin on the progression of adjuvant-induced arthritis in rats and explore the mechanisms underlying fisetin mediated immunomodulation. Adjuvant-induced arthritis (AIA) was induced by a single subcutaneous injection of Freund's complete adjuvant (FCA). AIA rats were treated with Fisetin daily via oral gavage, for a period of 28 days. Paw swelling changes were assessed and histopathological and radiographic analysis was conducted to evaluate the antiarthritic effect. Lipid peroxidation and antioxidant enzyme activities in the joint tissue homogenate were performed to observe the modulation of the antioxidant status along the expression of different pro-inflammatory cartilage cytokines, such as TNF-á and IL-6. Fisetin promotes both the antiarthritic and the antioxidant effect, as well as the suppression of lipid peroxidation. Fisetin significantly inhibited the development phase of arthritis, as supported by histopathological and radiographical observations, and reduced overexpression of cartilage cytokines. Fisetin not only suppressed the arthritic progression and tissue destruction, but it also demonstrated a pronounced anti-inflammatory and immunomodulatory action against the immunosuppressive properties of AIA and provided a superior effect against inflammation. Furthermore, fisetin therapy restored the BMD loss and acts as a potent antioxidant and immunomodulator, suggesting that oral administration can suppress arthritic progression in rats.

Resveratrol ameliorates rheumatoid arthritis via activation of SIRT1‐Nrf2 signaling pathway

The present study was designed to explore the biological role of resveratrol (RES) in rheumatoid arthritis (RA) and the underlying mechanism. The adjuvant-induced arthritic rats were administered RES on the 12th day after model establishment, and then arthritis assessment, oxidative stress measurement, histological examination, and immunohistochemical staining were performed. The primary rat fibroblast-like synoviocytes (FLS) were isolated and treated with RES in vitro and then cell proliferation and apoptosis assay were examined. Chromatin immunoprecipitation assay, luciferase reporter assay, intracellular reactive oxygen species (ROS) determination, western blot, and quantitative real time-polymerase chain reaction (qRT-PCR) were performed to investigate the mechanisms. RES administration decreased arthritis scores and serum levels of antioxidant enzymes, attenuated paw swelling, synovial hyperplasia, inflammatory cell infiltration, and cartilage degradation, as well as inhibited synoviocyte proliferation in synovial tissues. Further investigation indicated that RES inhibited ROS production and FLS proliferation through activating the silent information regulator 1 (SIRT1)/nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway. NF-κB was confirmed to negatively regulate miR-29a-3p and miR-23a-3p expression by directly binding to its promoter. Mechanistic analyses further revealed that Kelch-like erythroid cell-derived protein with CNC homology (ECH)-associated protein 1 (Keap1), a negative regulator of Nrf2, was a downstream target of miR-29a-3p, while miR-23a-3p directly targeted cullin3 (cul3), a master regulator of ubiquitination and degradation of Nrf2. Together, the present study provided evidence that RES ameliorated RA through activation of Nrf2-ARE signaling pathway via SIRT1/NF-κB/miR-29a-3p/Keap1 and SIRT1/NF-κB/miR-23a-3p/cul3 signaling pathway.