Published online Aug 15, 2001. doi: 10.3748/wjg.v7.i4.527
Revised: April 15, 2001
Accepted: April 22, 2001
Published online: August 15, 2001
AIM: To extract and purify the transforming growth factor β (TGFβ), and to demonstrate its biological activity in vivo and induction of apoptosis of hepatocytes in vitro.
METHODS: TGFβ was isolated from fresh bovine platelets by acid/ethanol extraction method and purified with ion exchange and gel chromatography. The extracted TGFβ as injected subcutaneously to mice, and its biological activity in vivo was observed 72 hrs post-injection by HE staining. The morphological changes were observed by HE staining and the occurrence of apoptosis was detected by TUNEL method after the human normal hepatic cell line QZG was treated with 8 μg·L-1TGFβ for 12 hrs in vitro.
RESULTS: The molecular mass 25 ku TGFβ protein was successfully extracted. It was able to induce localized granulation tissue formation in vivo. TGFβ-treated hepatocytes showed obvious apoptotic morphological changes, including the pyknosis and dense-stained nuclei and cytoplasm, the fragmentary, annular or crescent nuclei, and the “bubbling” cytoplasm. Moreover, its apoptotic rate was significantly higher than that of the control group (P < 0.05).
CONCLUSION: Biological active TGFβ protein is extracted and purified successfully from bovine platelets, and it is able to induce the apoptosis of hepatocytes.