Tissue-specific expression of ALA synthase-1 and heme oxygenase-1 and their expression in livers of rats chronically exposed to ethanol

Abstract 

5-Aminolevulinic acid synthase-1 (ALAS1) and heme oxygenase-1 (HO-1) are the rate-controlling enzymes for heme biosynthesis and degradation, respectively. Expression of these two genes showed tissue-specific expression pattern at both mRNA and protein levels in selected non-treated rat tissues. In the livers of rats receiving oral ethanol for 10 weeks, ALAS1 mRNA levels were increased by 65%, and the precursor and mature ALAS1 protein levels were increased by 1.8- and 2.3-fold, respectively, while no changes were observed in HO-1 mRNA and protein levels, compared with pair-fed controls. These results provide novel insights into the effects of chronic ethanol consumption on hepatic heme biosynthesis and porphyrias.

Abbreviations: ALAS1, 5-aminolevulinic acid synthase-1, ALAS2, 5-aminolevulinic acid synthase 2, ER, endoplasmic reticulum, GAPDH, glyceraldehyde 3-phosphate dehydrogenase, HO-1, heme oxygenase-1, LDC, Lieber-DeCarli, PCR, polymerase chain reaction, qRT-PCR, quantitative real-time PCR, SDS–PAGE, sodium dodecyl sulfate–polyacrylamide gel electrophoresis

Keywords: 5-Aminolevulinic acid synthase-1 (ALAS1), Heme oxygenase-1 (HO-1), Ethanol, Gene expression, Porphyria, Rat liver