ANTISENSE S-OLIGODEOXYNUCLEOTIDES DOWN-REGULATE TGF-BETA-PRODUCTION BY KUPFFER CELLS FROM CCL4-INJURED RAT LIVERS

TGF beta is a pleiotropic cytokine involved in multiple physiological and pathophysiological regulatory mechanisms. Since TGF beta is a disp arate modulator of cell recruitment, proliferation and extracellular m atrix phenotype for mesenchymal and nonmesenchymal cells, we have been investigating the role of this cytokine in the pathophysiology of liv er, In the present paper we investigate which hepatic cell types from CCl4-injured rat livers express TGF beta mRNA and produce TGF beta in culture, with the aim of further obliterating its biological activity by means of antisense technology. We performed a series of comprehensi ve molecular studies of in situ hybridization, northern blots, and RT- PCR and we found that only non-parenchymal cells produce TGF beta whil e its expression in hepatocytes was absent. Consistent with the in sit u hybridization findings, we observed that Kupffer cells expressed hig h steady-state levels of TGF beta mRNA, while circulating monocytes ex pressed a smaller amount of TGF beta transcripts. We did not detect TG F beta gene expression in endothelial cells. These findings were furth er confirmed by RT-PCR analyses. TGF beta activity, as measured by inh ibition of [H-3]thymidine incorporation by Mv 1 Lu mink lung epithelia l cells, was down-regulated in culture by antisense phosphorothioate o ligonucleotides. These effects of antisense oligomers were dose-depend ent and the sense oligonucleotides had no effect at the same concentra tion. (C) 1997 Elsevier Science B.V.