RT Journal Article SR Electronic T1 Autocrine activation by interleukin 1alpha induces the fibrogenic phenotype of systemic sclerosis fibroblasts. JF The Journal of Rheumatology JO J Rheumatol FD The Journal of Rheumatology SP 1946 OP 1954 VO 31 IS 10 A1 Yasushi Kawaguchi A1 Susan A McCarthy A1 Simon C Watkins A1 Timothy M Wright YR 2004 UL http://www.jrheum.org/content/31/10/1946.abstract AB OBJECTIVE: To explore the cellular localization of interleukin 1alpha (IL-1alpha) in cultured fibroblasts from lesional skin of patients with systemic sclerosis (SSc) and to study the role of intracellular IL-1alpha in the activation of fibroblasts. METHODS: Dermal fibroblasts were derived from 12 patients with SSc. Expression of IL-1alpha mRNA was examined using reverse transcriptase-polymerase chain reaction (RT-PCR). The cellular distribution of IL-1alpha was examined by subcellular fractionation, flow cytometry, and immunocytochemistry. A full-length IL-1alpha cDNA was subcloned into the pcDNA3 vector to create sense and antisense-encoding constructs. Normal and SSc fibroblasts were stably transfected with the sense and antisense-encoding constructs, respectively. Stably transfected fibroblast clones were analyzed for the production of procollagen and IL-6 protein by ELISA, alpha1(I) procollagen mRNA by Northern blot hybridization, and proliferation by [3H]thymidine incorporation. RESULTS: SSc-affected fibroblasts constitutively expressed intracellular IL-1alpha, which was predominantly located in the nucleus. Inhibition of IL-1alpha expression in SSc-affected fibroblasts using antisense constructs resulted in decreased proliferation, IL-6 production, and procollagen synthesis. Conversely, overexpression of IL-1alpha in normal fibroblasts resulted in development of the SSc fibroblast phenotype. CONCLUSION: IL-1alpha is an important autocrine fibrogenic factor in SSc, suggesting that inhibition of intracellular IL-1alpha may be a novel strategy for the treatment of SSc.