Starting at time 8 after CII task, mice had been treated daily with saline (0), 30 mg/kg TRYP, or 30 mg/kg TRYP-Ox until time 42

Starting at time 8 after CII task, mice had been treated daily with saline (0), 30 mg/kg TRYP, or 30 mg/kg TRYP-Ox until time 42. MMP-1/3 by FLS and synovial SW982 IL-6 and cells by FLS, SW982 cells, human umbilical vein endothelial cells (HUVECs), and monocytic THP-1 cells, although TRYP-Ox was generally more effective LSN 3213128 and experienced no cytotoxicity in murine arthritis models showed that both compounds significantly attenuated the development of collagen-induced arthritis (CIA) and collagen-antibodyCinduced arthritis (CAIA), with comparable efficacy. Collagen II (CII)-specific antibody levels were similarly reduced in TRYP- and TRYP-Ox-treated CIA mice. TRYP and TRYP-Ox also suppressed proinflammatory cytokine production by lymph node cells from CIA mice, with TRYP-Ox being more effective in inhibiting IL-17A, granulocyte-macrophage colony-stimulating factor (GM-CSF), and receptor activator of nuclear factor-B ligand (RANKL). Thus, even though TRYP-Ox generally experienced a better profile, possibly due to its ability to inhibit c-Jun N-terminal kinase (JNK), both TRYP and TRYP-Ox were equally effective in inhibiting the clinical symptoms and damage associated with RA. Overall, TRYP and/or TRYP-Ox may represent potential new directions for the pursuit of novel treatments for RA. (Brufani et?al., 1971), higher plants (Bergman et?al., 1985), and several species of marine micro- and macroorganisms [for review (Agafonova and Moskovkina, 2018)]. This compound has numerous pharmacological properties, including anti-inflammatory (Recio et?al., 2006; Iwaki et?al., 2011; Pathania et?al., 2014), antimicrobial (Honda et?al., 1979), antiviral (Tsai et?al., 2020), and anti-tumor activities (Kimoto et?al., 2001; Liao and Leung, 2013). For example, TRYP has been reported to reduce leukotriene-formation in human neutrophils and rat pleural exudates (Pergola et?al., 2012). Similarly, TRYP was found to be effective in protecting mice against experimentally-induced colitis regulation of the tumor necrosis factor (TNF)/nuclear factor (NF)-B and interleukin (IL)-6/transmission transducer and activator of transcription 3 (STAT3) signaling pathways (Wang et?al., 2018). Although there are no reported studies regarding the effects of TRYP on RA, the signaling pathways impacted by TRYP clearly play functions in RA pathogenesis [e.g., observe (Lubberts, 2015; Mitchell and Carmody, 2018)]. Thus, we hypothesized that TRYP or its structural analogs might be effective treatments for RA. Structural modification of natural compounds can increase compound potency and selectivity, enhance their pharmacological properties, and significantly diminish their detrimental effects (Guo, 2017). Several TRYP derivatives with numerous tetracyclic scaffold modifications have been developed, including compounds with anti-plasmodium and anti-toxoplasma properties (Krivogorsky et?al., 2008; Onambele et?al., 2015), indoleamine 2,3-dioxygenase inhibitors (Yang et?al., 2013), and DNA triplex stabilizing brokers (Chen et?al., 2007). Recently, we found that tryptanthrin-6-oxime (TRYP-Ox) experienced high affinity for JNK1-3 and also blocked activation of NF-B/AP-1 and the production of IL-6 by lipopolysaccharide-treated monocytic cells (Schepetkin et?al., 2019). Since JNK inhibition has potential for reducing inflammation associated with RA, it is affordable that JNK inhibitors could be developed as RA therapeutics (Han et?al., 2001; Bogoyevitch et?al., 2010; Koch et?al., 2015). Indeed, we found that 11and found that TRYP-Ox effectively inhibited IL-1-induced IL-6 secretion by FLS, SW-982 synovial cells, and THP-1 monocytic cells, whereas TRYP was generally less effective. We also investigated the effect of these compounds using collagen-induced arthritis (CIA) and collagen-antibody-induced arthritis (CAIA) models of RA and found that TRYP-Ox significantly reduced the clinical symptoms and Rabbit Polyclonal to PLA2G4C cartilage damage in CIA and CAIA. Surprisingly, TRYP was also effective in treating CIA and CAIA, although inhibition of cartilage destruction was more effective with TRYP-Ox. The therapeutic effects of TRYP and TRYP-Ox in CIA were associated with reduced levels of CII-specific antibodies and inhibition of proinflammatory cytokine production by lymph node (LN) cells. Overall, TRYP-Ox has LSN 3213128 a relatively greater therapeutic potential for treatment of RA compared to TRYP and represents a potential new direction for pursuit of novel treatments for RA. Materials and Methods Compounds TRYP was purchased from Combi-Blocks (San Diego, CA, USA). TRYP-Ox and IQ-1S were synthesized, as explained previously (Schepetkin et?al., 2019). The JNK inhibitor SP600125 was from Tocris Bioscience (Ellisville, MO, USA). For studies, the compounds were dissolved in dimethyl sulfoxide (DMSO) and diluted into the desired buffer or culture media. For treatments, the compounds were suspended in sterile phosphate buffer saline LSN 3213128 (PBS). CIA Induction, Treatment, and Clinical Evaluation DBA1/J male mice (6C8 weeks) were obtained from The Jackson Laboratories (Bar Harbor, ME, USA). All animal experiments were performed in accordance with National Institutes of LSN 3213128 Health guidelines and approved by the Montana State University Institutional Animal Care and Use Committee. To induce CIA in DBA1/J mice, immunization-grade bovine Type II collagen (CII) (Chondrex, Redmond, WA, USA) was solubilized in 0.05 M acetic acid (2 mg/ml), and 100 g of CII emulsified in complete Freunds adjuvant containing 4 mg/ml (Chondrex) were injected subcutaneously (strain 0111:B4 in PBS) on day 3. Control animals received an equal volume of PBS. Suspensions of TRYP, TRYP-Ox, and IQ-1S (all compounds in dose 30 mg/kg) or sterile saline were injected daily beginning at day 1 after injection of anti-CII.