Changes in transcripts of basement components during rat liver development: Increase in laminin messenger RNAs in the neonatal period

✍ Scribed by Shimon Reif; Donald Sykes; Thomas Rossi; Milton M. Weiser

• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: English
• Weight: 684 KB
• Volume: 15
• Category: Article
• ISSN: 0270-9139
• DOI: 10.1002/hep.1840150222

✦ Synopsis

The expression of laminin and type IV collagen messenger RNA in rat liver was investigated in relation to liver development. Levels of messenger RNA for laminin chains A, B1 and B2, and a1 and 012 chains of type IV collagen were studied by Northern-blot and dot-blot analysis. Although the expression of messenger RNAs for laminin €31 and B2 chains was higher in 19-day gestational fetal liver when compared with the adult, the highest level was detected in 15-day newborns. This finding coincides with the final establishment of the mature liver. Laminin A messenger RNA was not detected in the 19-day gestational fetus or in the neonatal period. In contrast, al-(IV) and &-(IV) collagen messenger RNAs maintained high levels in the early neonate and then decreased gradually after 15 days. Our findings suggest that during late stages of liver ontogeny the main components of liver basement membrane proteins undergo a significant alteration in their synthesis. The data further suggest that laminin may play a role in the final stages of hepatic differentiation. (HEPATOLOGY 1992;15:310-315.)

The liver extracellular matrix consists of two distinct structures: the perisinusoidal connective tissue, which contains interstitial components such as collagen types I and I11 and fibronectin, and the basement membrane compartment, which contains collagen type IV and laminin (1, 2 ) . The basement membrane of the liver serves a scaffolding function, separates epithelial and endothelial cells from underlying stroma and provides a barrier to the passage of macromolecules and cells (3-5).

In addition to their cell adhesive properties, basement membrane components, particularly laminin, can stim-