Interleukin-10 gene modification attenuates hepatocyte activation of rat hepatic stellate cells in vitro.

Activation of hepatic stellate cells (HSCs) plays a key role in the progression of liver fibrosis. Interleukin-10 (IL-10), a potential anti-fibrosis cytokine, has an unfavorable pharmacokinetic profile, which limits its clinical applications. A liver-targeting gene delivery system may maintain a longer-lasting concentration in hepatic tissue with fewer side­effects in non-target tissues. In the present study, when delivered by asialoglycoprotein receptor-mediated liposomes, the IL-10 gene was highly expressed in BRL cells (a rat hepatocyte line) and attenuated the apoptosis of BRL cells induced by plasmid transfection. In a co-culture system, BRL cells demonstrated a marked ability to stimulate the proliferation of primary HSCs and their expression of α-SMA and procollagen type I. Following modification of the BRL cells with the IL-10 gene, this stimulation was attenuated and an accelerated apoptosis of the HSCs was induced. These results suggest that hepatocyte­targeting gene delivery may be an ideal technique for the IL-10 gene therapy of liver fibrosis, which requires further confirmation by in vivo studies.

[Construction of eukaryotic expression plasmid containing rat interleukin-10 gene and its expression in BRL cells in vitro].

AIM: To construct eukaryotic expression vector of rat IL-10 gene and observe its expression in hepatocyte cell line BRL. METHODS: Total RNA was extracted from rat peripheral blood mononuclear cells. The full length coding region of IL-10 was amplified by RT- nested PCR and cloned into eukaryotic expression vector pcDNA3.0. The recombinant plasmid was transfected into BRL cells with either liposome Transfast or asialoglycoprotein receptor mediated liposome PEIjet-gal respectively. The expression of IL-10 mRNA was detected with PCR and that of IL-10 secreted from BRL cells transfected by liposome PEIjet-gal was detected with ELISA. RESULTS: The recombinant plasmid was identified and confirmed with digestion of restriction endonuclease and DNA sequencing. Receptor mediated liposome PEIjet-gal exhibited significantly higher transfection efficiency than liposome Transfast and higher level secretory IL-10 expressed in BRL cells. CONCLUSION: The eukaryotic expression vector of IL-10 gene was successfully constructed. Asialoglycoprotein receptor-mediated liposome had high transfection efficiency on hepatocytes, suggesting that it could be a potential hepatocyte-targeting delivery system for IL-10 gene therapy.