Prevention of CCl4-induced liver cirrhosis by ribbon antisense to transforming growth factor-β1

Transforming growth factor-Bl (TGF-s1) is an important mediator of tissue fibrosis, including liver cirrhosis. Ribbon-type antisense oligonucleotide to TGF-s1 (TGF-s1 RiAS) was designed and combined with cationic peptide derived from the nuclear localization signal of human immunodeficiency virus-1 Tat protein for enhanced cellular uptake. When Hepalclc7 cells were transfected with TGF-s1 RiAS, the level of TGF-s1 mRNA was reduced by >70%. TGF-s1 RiAS, mismatched RiAS, and normal saline were each injected into mice via the tail vein, beginning the week after intraperitoneal CCl 4 injection and continuing for 7 weeks, in order to determine whether TGF-s1 RiAS prevents the fibrotic changes induced by the CCl 4 injection. After 8 weeks of the experiment, all of the mice treated with TGF-s1 RiAS survived, compared to 50% of the control group and 65% of the mismatched RiAS-treated group. Upon examining the biochemical effects on the liver, TGF-s1 mRNA levels were reduced significantly only in the TGF-s1 RiAS-treated group. Immunohistochemical studies showed a reduced accumulation of collagen and α-smooth muscle actin. Our experimental results suggest that ribbon antisense to TGF-s1, with efficient uptake, effectively blocks the expression of TGF-s1 and prevents fibrosis of the liver.