Basic Research
Copyright ©2005 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 21, 2005; 11(15): 2264-2268
Published online Apr 21, 2005. doi: 10.3748/wjg.v11.i15.2264
Effects of fibril- or fixed-collagen on matrix metalloproteinase-1 and tissue inhibitor of matrix metalloproteinase-1 production in the human hepatocyte cell line HLE
Makoto Nakamuta, Kazuhiro Kotoh, Munechika Enjoji, Hajime Nawata
Makoto Nakamuta, Kazuhiro Kotoh, Munechika Enjoji, Hajime Nawata, Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
Author contributions: All authors contributed equally to the work.
Correspondence to: Makoto Nakamuta, Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. nakamuta@intmed3.med.kyushu-u.ac.jp
Telephone: +81-92-642-5282 Fax: +81-92-642-5287
Received: June 15, 2004
Revised: June 16, 2004
Accepted: August 21, 2004
Published online: April 21, 2005
Abstract

AIM: Matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) are central to the spontaneous resolution of liver fibrosis. The mechanisms involved have been investigated in hepatic stellate cells (HSC), but not in hepatocytes. We investigated the effects of fibril- and fixed-collagen on MMP-1 and TIMP-1 production in hepatocytes, using the HLE cell line.

METHODS: Fibril type I and IV collagen were prepared by HCl digestion of type I and IV collagen, respectively. For fixed-collagen, culture dishes were coated with fibril type I or IV collagen and fixed by ultraviolet. Type I collagenase activity was measured using fluorescein isothiocyanate-labeled type I collagen. MMP-1 and TIMP-1 in HLE cells were measured by a one-step sandwich enzyme immunoassay.

RESULTS: Both fibril type I and IV collagen significantly increased type I collagenase activity about two-fold compared with no fibril collagen. The effects of the fibril collagen were not affected by the coating condition. There was no significant difference in the effects on collagenase activity between cells cultured in medium containing fibril type I collagen and those cultured in the presence of type IV collagen. Both types of fibril collagen significantly increased MMP-1 production, and showed more than 10-fold higher levels of MMP-1 than the control. The enhanced MMP-1 production by fibril collagens was unaffected by the coating condition. By contrast, TIMP-1 production was not changed by the addition of fibril type I or IV collagen, and neither was it affected by the coating conditions. Coating with type I collagen significantly suppressed MMP-1 production by almost one-tenth compared with no coating. By contrast, TIMP-1 production was not affected by either the absence of a collagen coat or by increasing the concentration of the coating collagen.

CONCLUSION: These results indicated that, in HLE cells, fibril- and fixed-collagen have opposite effects on MMP-1 production without affecting TIMP production. Fibril collagen induced collagenase activity by up-regulation of MMP-1 production without affecting TIMP-1 production. By contrast, fixed collagen reduced MMP-1 production. Our results suggest that hepatocytes might also play an important role in the regulation of the hepatic fibrosis alongside HSC.

Keywords: Hepatocyte; Fibril-collagen; Fixed collagen