RESUMEN
The IL-1ß gene can be also be spliced with the intron 4 retention; the result is a IL-1ß splice variant 1 (IL-1ßsv1), which was significantly up-regulated in failing myocardium of dogs suffering from chronic degenerative valvular disease (CDVD). Expression of IL-1ßsv1 was assessed, at both RNA and protein levels, in organs affected by heart failure, namely, kidneys, liver, and lungs from 35 dogs suffering chronic degenerative valvular disease (CDVD) and in 20 disease free control dogs. IL-1ßsv1 RNA was detected in the dogs from both groups. In the CDVD group, the highest RNA and protein IL-1ßsv1 levels were observed in lungs, followed, in that order, by the liver and kidneys. IL-1ßsv1 protein was found in the cytoplasm of hepatocytes and IL-1ßsv1-overexpressing DH82 cells. In lungs, IL-1ßsv1 was localized in the cytoplasm and in the nuclei of bronchiolar epithelial and smooth-muscle cells. Cytoplasmic and nuclear IL-1ßsv1 expression was observed in macrophages, and a strong nuclear signal was detected in epithelial cells of the alveolar sacs. Following lipopolysaccharide (LPS) stimulation, overexpression of IL-1ßsv1 in DH82 cells decreased the pro-inflammatory response. Our results indicate that IL-1ßsv1 is constitutively expressed in both normal tissues and in tissues from cases of heart failure. The presence of IL-1ßsv1 in tissues exposed to invading agents and its anti-inflammatory activity in DH82 cells may point to its immunomodulatory role in vivo.
