Analysis of dimethyl sulfoxide immunosuppression in the rat model of collagen II autoimmune arthritis: an effect dependent upon intraperitoneal administration and associated with toxicity

Thawed cryopreserved synovial mesenchymal stem cells show comparable effects to cultured cells in the inhibition of osteoarthritis progression in rats

Intra-articular injections of mesenchymal stem cells (MSCs) can inhibit the progression of osteoarthritis (OA). Previous reports have used cultured MSCs, but the ability to use thawed cryopreserved MSC stocks would be highly advantageous. Our purpose was to elucidate whether thawed cryopreserved MSCs show comparable inhibitory effects on OA progression in rats to those obtained with cultured MSCs. Cultured rat synovial MSCs or thawed MSCs were compared for in vitro viability and properties. The inhibitory effect of thawed MSCs on OA progression was evaluated by injecting cryopreservation fluid and thawed MSCs in meniscectomized rats. Cartilage degeneration was assessed using gross finding and histological scores. Cultured MSCs were then injected into one knee and thawed MSCs into the contralateral knee of the same individual to compare their effects. Cultured MSCs and MSCs thawed after cryopreservation had comparable in vitro colony formation and chondrogenic potentials. In the rat OA model, the gross finding and histological scores were significantly lower in the thawed MSC group than in the cryopreservation fluid group at 8 weeks. Finally, cartilage degeneration did not differ significantly after injection of cultured and thawed MSCs. In conclusion, thawed MSCs showed comparable inhibitory effects on OA progression to cultured MSCs.

Adenosine receptor antagonism suppresses functional and histological inflammatory changes in the rat urinary bladder

Cyclophosphamide (CYP) induces an interstitial cystitis-like inflammation. The resulting bladder dysfunction has been associated with increased release of adenosine-5'-triphosphate (ATP), structural bladder wall changes and contractile impairment. Due to the inflammatory modulatory effects of purines it was presently wondered if pre-treatment with P1 and P2 purinoceptor antagonists affect the CYP-induced alterations. Rats were pre-treated with saline or antagonists for five days, and 60 h before the in vitro functional examination the rats were administered either saline or CYP. Histological examination revealed CYP-induced bladder wall thickening largely depending on submucosal enlargement, mast cell invasion of the detrusor muscle, increase in muscarinic M5 receptor expression and macrophage migration inhibitory factor (MIF) occurrence in large parts of the urothelium. Functionally, methacholine- and ATP-evoked contractions were smaller in urinary bladders from CYP-treated rats. Pre-treatment with the P2 purinoceptor antagonist suramin and the P1A2B antagonist PSB1115 did not to any great extent affect the CYP-induced changes. The P1A1 antagonist DPCPX, however, abolished the difference of methacholine-evoked contractions between saline- and CYP-treated rats. ATP-evoked contractions were reduced in control after the DPCPX pre-treatment, but not in cystitis. The functional observations for DPCPX were supported by its suppression of CYP-induced submucosal thickening, muscarinic M5 receptor expression and, possibly, detrusor mast cell infiltration and the spread of urothelial MIF occurrence. Thus, P1A1 is an important pro-inflammatory receptor in the acute CYP-induced cystitis and a P1A1 blockade during the initial phase may suppress CYP-induced cystitis. P1A1 purinoceptors seem to regulate contractility in healthy and in inflamed rat urinary bladders.

The role of IL-4 in regulation of murine collagen-induced arthritis

Collagen-induced arthritis (CIA) is a murine model of autoimmune-mediated polyarthritis. CIA can be prevented by the administration (intravenously) of CII, inducing regulatory CD4+ T cells which produce Th2 cytokines. However, the relative importance of IL-4 in suppressing arthritis remains unclear. To address this question, a neutralizing monoclonal antibody to IL-4 was given to mice treated with tolerized, CII-specific cells. The antibody significantly reversed the expected suppression of arthritis. Moreover, CII administered intravenously to DBA/1 IL4-/- mice (developed by backcrossing C57B1/6 IL4-/- to wild-type DBA/1 mice) was completely ineffective in suppressing disease. These data support the importance of IL-4 in the regulation of autoimmune arthritis. Compensatory increases in mRNA message for other Th2 cytokines were observed, but they did not restore suppression of arthritis. Antibodies to CII, mostly IgG2a, were increased in IL4-/- mice. These studies represent a unique opportunity to analyze the role of IL-4 and its absence on an autoimmune murine model of arthritis.

Topical agents in the treatment of rheumatic disorders

Topical drug delivery may be the optimal route for the treatment of localized musculoskeletal disorders because higher drug concentrations can be achieved at the sites of clinical significance. The rationale for the use of topical salicylates and other nonsteroidal anti-inflammatory drugs (NSAIDs) in the treatment of soft-tissue rheumatic complaints and osteoarthritis is reviewed. Topical capsaicin offers another potentially beneficial therapy for the treatment of osteoarthritis of selected joints. Although there are extensive, uncontrolled experiences with DMSO that suggests its effectiveness in the treatment of musculoskeletal disorders, controlled trials yield conflicting results. The basis for the use of physical modalities such as phonophoresis and iontophoresis to improve topical drug efficacy is summarized.