Hydrodynamic-based in vivo transfection of retinoic X receptor-alpha gene can enhance vitamin A-induced attenuation of liver fibrosis in mice.
OBJECTIVE
In hepatic stellate cells isolated from rat fibrotic livers, the amount of retinoid X receptor-alpha (RXR-alpha) mRNA is greatly reduced. However, the effectiveness of retinoids in the treatment of liver fibrosis is controversial. We hypothesized that increasing the expression levels of RXR-alpha in livers will improve the response of liver fibrosis to retinoids treatment.


METHODS
pTracer-CMV2 vector harboring both green fluorescent protein and RXR-alpha genes was given to mice with carbon tetrachloride (CCl(4))-induced liver fibrosis, by hydrodynamic-based in vivo transfection. Vitamin A was simultaneously administered to the mice. Sirius red staining and measurement of hydroxyproline content were performed to evaluate liver fibrosis. The incorporation of 5-bromo-2-deoxyribouridine (BrdU) was carried out to determine liver cell proliferation.


RESULTS
Successful transfection and expression of exogenous RXR-alpha gene in the liver was determined by observance of green fluorescence under a confocal microscope, and detection of RXR-alpha protein by immunohistochemistry. Hepatic fibrosis, evaluated by both Sirius red staining with image analysis and quantity of hydroxyproline in livers of RXR-alpha-transfected group, tapered off remarkably. The hydroxyproline content and Sirius red-positive staining area on liver sections from RXR-alpha-transfected mice decreased by 34.3% and 54.63%, respectively, compared with the control group receiving empty vector. The labeling index of BrdU in non-parenchymal cells was much lower in livers from the RXR-alpha-transfected group than that of empty vector-transfected group.


CONCLUSIONS
Hydrodynamic-based in vivo transfection of the RXR-alpha gene can enhance the vitamin A-induced attenuation of liver fibrosis in mice. One of the possible mechanisms of action for this gene treatment is inhibition of non-parenchymal cell proliferation mainly composed of hepatic stellate cells in fibrotic livers.
Chen
Chen
C
Department of Pathology, Shanghai Medical College, Fudan University, Shanghai, China.
Zhang
Jinsheng
J
Li
Jinjun
J
Huang
Jin
J
Yang
Chen
C
Huang
Guangcun
G
Shi
Jianying
J
D000818:Animals; D049109:Cell Proliferation; D004195:Disease Models, Animal; D015316:Genetic Therapy / Q000379:methods*; D022781:Hepatocytes / Q000378:metabolism; D007150:Immunohistochemistry; D008106:Liver Cirrhosis, Experimental / Q000473:pathology* / Q000628:therapy*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D018613:Microscopy, Confocal; D011336:Probability; D012333:RNA, Messenger / Q000378:metabolism; D047488:Retinoid X Receptors / Q000235:genetics*; D012680:Sensitivity and Specificity; D014162:Transfection; D014801:Vitamin A / Q000494:pharmacology*
D012333:RNA, Messenger; D047488:Retinoid X Receptors; D014801:Vitamin A