Alpha-melanocyte-stimulating hormone gene therapy reverses carbon tetrachloride induced liver fibrosis in mice.
BACKGROUND
Hepatic fibrosis represents a process of healing and scarring in response to chronic liver injury. Effective therapies are lacking. We have previously demonstrated that alpha-melanocyte-stimulating hormone (alpha-MSH) gene therapy protects against thioacetamide-induced acute liver failure in mice. Recent reports showed that collagen metabolism is a novel target of alpha-MSH. Therefore, the aim of this study is to investigate whether alpha-MSH gene therapy possesses anti-hepatic fibrogenic effect in mice.


METHODS
Liver fibrosis was induced in mice by administering carbon tetrachloride (CCl4) continuously for 10 weeks. Alpha-MSH expression plasmid was delivered via electroporation after liver fibrosis had been established. Histopathology, reverse-transcription polymerase chain reaction (RT-PCR), immunoblotting, and gelatin zymography were used to investigate its possible mechanisms of action.


RESULTS
Alpha-MSH gene therapy reversed established liver fibrosis in CCl4-treated mice. RT-PCR revealed that alpha-MSH gene therapy attenuated the liver TGF-beta1, collagen alpha1, and cell adhesion molecule mRNA upregulation. Following gene transfer, both the activation of alpha-smooth muscle actin (alpha-SMA) and cyclooxygenase-2 (COX-2) was significantly attenuated. Further, alpha-MSH significantly increased matrix metalloproteinase (MMP) activity with tissue inhibitors of matrix metalloproteinase (TIMP) inactivation.


CONCLUSIONS
We have demonstrated that alpha-MSH gene therapy reversed established liver fibrosis in mice. It also prevented the upregulated fibrogenic and proinflammatory gene response after CCl4 administration. Its collagenolytic effect may be attributed to MMP and TIMP modulation. In summary, alpha-MSH gene therapy may be an effective therapeutic modality against liver fibrosis with potential clinical use.
Lee
Tsung-Hsing
TH
Department of Anesthesiology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan.
Jawan
Bruno
B
Chou
Wen-Ying
WY
Lu
Cheng-Nan
CN
Wu
Chia-Ling
CL
Kuo
Hsiao-Mei
HM
Concejero
Allan M
AM
Wang
Cheng-Haung
CH
D000199:Actins / Q000378:metabolism; D000818:Animals; D002251:Carbon Tetrachloride / Q000633:toxicity*; D015815:Cell Adhesion Molecules / Q000235:genetics; D051546:Cyclooxygenase 2 / Q000378:metabolism; D018274:Electroporation; D004789:Enzyme Activation; D005780:Gelatin / Q000378:metabolism; D005786:Gene Expression Regulation; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D007249:Inflammation / Q000235:genetics; D008099:Liver / Q000166:cytology / Q000473:pathology; D008103:Liver Cirrhosis / Q000139:chemically induced / Q000235:genetics* / Q000473:pathology* / Q000628:therapy; D008297:Male; D020782:Matrix Metalloproteinases / Q000235:genetics; D051379:Mice; D008813:Mice, Inbred ICR; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000235:genetics; D000521:alpha-MSH / Q000235:genetics* / Q000378:metabolism*
D000199:Actins; D015815:Cell Adhesion Molecules; D012333:RNA, Messenger; D019715:Tissue Inhibitor of Metalloproteinase-1; D000521:alpha-MSH; D005780:Gelatin; D002251:Carbon Tetrachloride; D051546:Cyclooxygenase 2; D020782:Matrix Metalloproteinases