ABSTRACT
AIM: Liver fibrosis represents a process of healing and scarring in response to chronic liver injury. Effective therapies for liver fibrosis are lacking. Interleukin-10 (IL-10) is a cytokine that downregulates pro-inflammatory responses and has a modulatory effect on hepatic fibrogenesis. The aim of this study was to investigate whether electroporative IL-10 gene therapy has a hepatic fibrolytic effect on mice. METHODS: Hepatic fibrosis was induced by administering carbon tetrachloride (CCl4) for 10 weeks in mice. The human IL-10 expression plasmid was delivered via electroporation after hepatic fibrosis was established. Histopathology, reverse transcription polymerase chain reaction (RT-PCR), immunoblotting, and gelatin zymography were used to investigate the possible mechanisms of action of IL-10. RESULTS: Human IL-10 gene therapy reversed CCl4-induced liver fibrosis in mice. RT-PCR revealed that IL-10 gene therapy attenuated liver TGF-beta1, collagen alpha1, fibronectin, and cell adhesion molecule mRNA upregulation. Following gene transfer, both the activation of alpha-smooth muscle actin and cyclooxygenase-2 were significantly attenuated. Furthermore, IL-10 significantly inhibited matrix metalloproteinase-2 (MMP-2) and tissue inhibitors of matrix metalloproteinase (TIMP) activation after CCl4 intoxication. CONCLUSIONS: We demonstrated that IL-10 gene therapy attenuated CCl4-induced liver fibrosis in mice. IL-10 prevented upregulated fibrogenic and pro-inflammatory gene responses. Its collagenolytic effect may be attributed to MMP and TIMP modulation. IL-10 gene therapy may be an effective therapeutic modality against liver fibrosis with potential clinical use.
Subject(s)
Genetic Therapy , Interleukin-10/genetics , Liver Cirrhosis, Experimental , Actins/metabolism , Animals , Collagen Type I/metabolism , Cyclooxygenase 2/metabolism , Electroporation , Fibronectins/metabolism , Gene Transfer Techniques , Intercellular Adhesion Molecule-1/metabolism , Liver/metabolism , Liver/pathology , Liver Cirrhosis, Experimental/therapy , Male , Matrix Metalloproteinase 2/metabolism , Mice , Mice, Inbred ICR , RNA, Messenger/biosynthesis , RNA, Messenger/genetics , Tissue Inhibitor of Metalloproteinases/metabolism , Transforming Growth Factor beta/metabolism , Transforming Growth Factor beta1 , Tumor Necrosis Factor-alpha/metabolism , Vascular Cell Adhesion Molecule-1/biosynthesis , Vascular Cell Adhesion Molecule-1/geneticsABSTRACT
Hepatic fibrosis represents a process of healing and scarring in response to chronic liver injury. Interleukin-10 (IL-10) is a cytokine that downregulates the proinflammatory response and has a modulatory effect on hepatic fibrogenesis. The aim of this study was to investigate whether IL-10 gene therapy possesses anti-hepatic fibrogenesis in mice. Liver fibrosis was induced by long-term thioacetamide administration in mice. Human IL-10 expression plasmid was delivered via electroporation after liver fibrosis established. IL-10 gene therapy reversed hepatic fibrosis and prevented cell apoptosis in a thioacetamide-treated liver. RT-PCR revealed IL-10 gene therapy to reduce liver transforming growth factor-beta1, tumor necrosis factor-alpha, collagen alpha1, cell adhesion molecule, and tissue inhibitors of metalloproteinase mRNA upregulation. Following gene transfer, the activation of alpha-smooth muscle actin and cyclooxygenase-2 was significantly attenuated. In brief, IL-10 gene therapy might be an effective therapeutic reagent for liver fibrosis with potential future clinical applications.
Subject(s)
Genetic Therapy , Interleukin-10/genetics , Liver Cirrhosis/therapy , Thioacetamide/toxicity , Animals , Base Sequence , Blotting, Western , Cyclooxygenase 2 , DNA Primers , Immunohistochemistry , In Situ Nick-End Labeling , Liver Cirrhosis/chemically induced , Male , Mice , Mice, Inbred ICR , Prostaglandin-Endoperoxide Synthases/metabolism , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
AIM: To investigate effects of the cyclin-dependent kinase5 (Cdk5) inhibitor roscovitine on formalin-induced nociceptive responses in rats. METHODS: The flinch response as a methood of pain threshold measurement and intrathecal injection techniques were used. Cdk5 and phosphorylation of its downstream target, DARPP-32 (dopamine- and cAMP-regulated phosphoprotein of M(r) 32 kDa), were investigated by Western blot analysis. RESULTS: Rats demonstrated a typical flinch response after formalin injection. Intrathecal roscovitine injections significantly suppressed the flinch response in a dose-dependent manner. Western blot analysis showed that phosphorylated DARPP-32 at Thr75 increased in concentration after formalin hyperalgesia, with this effect reduced by roscovitine administration. This antinociception was partially attenuated by administration of naloxone before the formalin test. CONCLUSION: DARPP-32 phosphorylation is involved in acute inflammatory pain response. Intrathecal roscovitine administration attenuates formalin-induced nociceptive responses and there is potential for further application.
