ABSTRACT
BACKGROUND: Collagen-induced arthritis (CIA), a murine experimental disease model induced by immunization with type II collagen (CII), is used to evaluate novel therapeutic strategies for rheumatoid arthritis. Adult stem cell marker Musashi-1 (Msi1) plays an important role in regulating the maintenance and differentiation of stem/precursor cells. The objectives of this investigation were to perform a morphological study of the experimental CIA model, evaluate the effect of TNFα-blocker (etanercept) treatment, and determine the immunohistochemical expression of Msi1 protein. METHODS: CIA was induced in 50 male DBA1/J mice for analyses of tissue and serum cytokine; clinical and morphological lesions in limbs; and immunohistochemical expression of Msi1. RESULTS: Clinically, TNFα-blocker treatment attenuated CIA on day 32 after immunization (P < 0.001). Msi1 protein expression was significantly higher in joints damaged by CIA than in those with no lesions (P < 0.0001) and was related to the severity of the lesions (Spearman's rho = 0.775, P = 0.0001). CONCLUSIONS: Treatment with etanercept attenuates osteoarticular lesions in the murine CIA model. Osteoarticular expression of Msi1 protein is increased in joints with CIA-induced lesion and absent in nonlesioned joints, suggesting that this protein is expressed when the lesion is produced in order to favor tissue repair.
Subject(s)
Arthritis, Experimental/genetics , Arthritis, Rheumatoid/genetics , Nerve Tissue Proteins/biosynthesis , RNA-Binding Proteins/biosynthesis , Animals , Arthritis, Experimental/physiopathology , Arthritis, Rheumatoid/pathology , Cell Differentiation/genetics , Disease Models, Animal , Humans , Mice , Nerve Tissue Proteins/genetics , RNA-Binding Proteins/genetics , Stem Cells/metabolismABSTRACT
INTRODUCTION: It is difficult to prevent and treat intra- and peri-neural fibrosis after peripheral nerve surgery. Many authors have attempted to develop and verify the effectiveness of substances to decrease the formation of adherences in different tissues. MATERIAL AND METHODS: this study aimed to assess the effectiveness of a barrier of oxidized regenerated cellulose (ORC) to reduce adherence and perineural fibrosis in a model of surgical perineural induced fibrosis in rat sciatic nerve in 40 rats. After tissue aggression, the nerve of the right rear limb was wrapped in ORC and the left limb served as control. Animals were killed at 3 and 6 weeks, and nerves and muscle mass were extracted en bloc. Connective tissue was quantified by conventional histopathological techniques and Fibrosis HR(R) automatic image analysis. RESULTS: No significant differences were found in intra- or peri-neural induced fibrosis between control nerves (6.88% and 8.90%, respectively) and treated nerves (6.57% and 9.90%) at 3 or 6 weeks (10.41% and 12.51% in controls; 11.85% and 15.72% in treated nerves). Inflammatory phenomena and granulomatous reactions were more frequent in treated animals. CONCLUSIONS: ORC conferred no advantage in prevention of nerve fibrosis and might have interfered with healing.
