101. Autocrine activation by interleukin 1alpha induces the fibrogenic phenotype of systemic sclerosis fibroblasts.
- Author
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Kawaguchi Y, McCarthy SA, Watkins SC, and Wright TM
- Subjects
- Cell Proliferation, Cells, Cultured, Fibroblasts cytology, Fibrosis, Humans, Interleukin-1 genetics, Interleukin-6 metabolism, Oligonucleotides, Antisense genetics, Oligonucleotides, Antisense metabolism, Phenotype, Procollagen metabolism, RNA, Messenger metabolism, Subcellular Fractions metabolism, Autocrine Communication, Fibroblasts physiology, Interleukin-1 metabolism, Scleroderma, Systemic immunology, Scleroderma, Systemic pathology
- Abstract
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.
- Published
- 2004