Study on Dynamic Changes and Correlation of Serum Levels of Transforming Growth Factor β1 and Radiation-induced Hepatic Fibrosis in Rat

Objective: Radiation therapy of liver carcinoma may lead to the complication of radiation- induced liver disease(RILD), hepatic fibrosis, even hepatic cirrhosis. So it is of great significance to look for better serum markers for noninvasively diagnosing and monitoring radiation-induced hepatic fibrosis. In this study, we established the rats model of radiation-induced hepatic fibrosis,detected the dynamic changes of serum levels of transforming growth factor beta 1(TGF-β1), explored the correlation of TGF-β1 and the severity of radiation-induced hepatic fibrosis, and discovered the diagnosis value of TGF-β1. Methods: Forty healthy male Sprague-Dawley rats were randomly divided into model group(30 rats) and control group(10 rats). The right-half of rat liver in model group was irradiated with a single dose of 25 Gy to establish radiation-induced hepatic fibrosis model. Liver tissues from the irradiated liver, and blood sample were collected at different time points(2 months, 4 months, 6 months) after irradiation. Expression of TGF-β1 by enzyme-linked immunosorbent assay(ELISA) was performed. Pathomorphological change in the liver was observed with hematoxylineosin staining by optical microscope. Results: The expression of serum TGF-β1 of model group at different time points [2 months,(551.03±69.00) ng/L; 4 months,(645.31±109.29) ng/L; 6 months,(737.89±118.11) ng/L] was significantly higher than that of the control group(451.71±51.12 ng/L, P0.05). There were distinctly positive correlation between the serum of TGF-β1 value and severity of hepatic fibrosis(r=0.82, P0.01). Conclusion: In the development of radiation- induced fibrosis, TGF-β1 rises with the severity of hepatic fibrosis. We provide a new noninvasive and convenient means for monitoring the severity of hepatic fibrosis, and lay a theoretical foundation for subsequent TGF-β1 as a serum marker applied to clinical research of radiation-induced hepatic fibrosis.