A collagen enhancer-promoter construct in transgenic mice is markedly stimulated by ethanol administration
✍ Scribed by C M Walton; G Y Wu; C A Petruff; S H Clark; A C Lichtler; C H Wu
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 275 KB
- Volume
- 23
- Category
- Article
- ISSN
- 0270-9139
No coin nor oath required. For personal study only.
✦ Synopsis
tion assays. Furthermore, the transgene product as mea-Type I collagen synthesis and deposition is generally sured by CAT activity in ethanol-treated mice was signifindicative of irreversible damage in alcohol-induced ciricantly increased threefold over saline-treated controls. rhosis in humans. However, in rodents, ethanol alone We conclude that the 5-flanking region of the rat a1(I) does not readily cause hepatic fibrosis. To determine collagen gene does contain regulatory elements that are whether this is because of a lack of ethanol-responsive strongly responsive to ethanol administration. (HEPAelements, an artificial enhancer construct controlling TOLOGY 1996;23:310-315.) rat type I collagen gene transcription was prepared in transgenic mice. The gene construct, ColCAT3.6, was a chimeric sequence containing the marker chloramphen-The regulation of collagen synthesis is important in icol acetyltransferase (CAT) gene linked to 3.5 kb of the the control of the formation of normal extracellular marat a1(I) 5-flanking DNA, and 115 base pairs (bp) of trantrices as well as the pathological ones that occur in scribed collagen gene. Groups of transgenic mice were fibrotic diseases. It has been shown previously that in given 4 g/kg ethanol orally, twice daily for 4 weeks. As
a positive control for hepatic fibrosis, transgenic mice fibrotic states, type III collagen is deposited inwere given intraperitoneal injections of CCl 4 , twice itially, 1-3 whereas in later stages, type I collagen preweekly for 4 weeks. Livers were assayed for CAT activdominates as a major component of fibrous bands. In ity. Endogenous mouse collagen a1(I) messenger RNA humans, the major causes of liver fibrosis, viral hepati-(mRNA) and transgene CAT mRNA were measured by tis and ethanol abuse, both have been found to follow RNase protection assays. Collagen synthesis in livers this pattern. 1 However, in rodents, ethanol given in from the transgenic mice treated with ethanol were inthe diet does not produce the fibrotic scarring seen in creased over controls, but the levels were not signifihumans. Only by intragastric infusion of high levels of cantly different. Endogenous collagen a1(I) steady-state ethanol can some semblance of alcohol-induced fibrosis mRNA levels in ethanol-treated mice were not signifibe simulated. 4 To determine whether certain regulacantly different compared with saline-treated controls.
However, the transgene mRNA levels in ethanol-treated tory elements that govern the transcription of the collaanimals increased approximately 21-fold compared with gen gene in rodents might be responsible for this obsaline-treated controls, as measured by RNase protecserved difference in response, we used transgenic mice with a chimeric collagen promoter construct to obtain simultaneous measurements of endogenous and trans-Abbreviations: bp, base pairs; CAT, chloramphenicol acetyltransferase;
gene constructs in response to ethanol.
mRNA, messenger RNA.