Gene expression of albumin and liver-specific nuclear transcription factors in liver of protein-deprived rats.
Protein-energy malnutrition causes hypoalbuminemia. Recent work has suggested that this may be partly due to decreased transcription of the albumin gene. This study examined the role of cis-acting and transacting elements of the albumin gene during protein deprivation. Male 7-wk-old Donryu rats were fed a protein-free diet (0% casein diet) for 10 d or given restricted (pair-fed control) or free access (freely fed control) to a 25% casein diet. Serum albumin concentrations were significantly lower in the protein-deprived rats (29 +/- 1 g/L) than in the pair-fed controls (42 +/- 3 g/L) or the freely fed controls (45 +/- 3 g/L). The albumin mRNA level was also significantly lower in livers of protein-deprived rats (36% of pair-fed control). However, gel mobility shift analysis using liver nuclear extracts did not show any significant difference between the protein-deprived rats and the pair-fed controls in the binding activity to the B and D sites of the albumin promoter. Furthermore, gel mobility shift-Western blot analysis showed no significant difference between the two groups in the protein levels of nuclear transcription factors binding to the D sites. The amounts of mRNA of hepatocyte nuclear factor-1 binding to the B site were not significantly different between these two groups. These results suggest that the proximal promoter region may not play a major role in the down-regulation of the albumin gene during protein deprivation.
Ogawa
A
A
Department of Surgery II, Osaka University Medical School, Japan.
Yano
M
M
Tsujinaka
T
T
Ebisui
C
C
Morimoto
T
T
Kishibuchi
M
M
Fujita
J
J
Morita
S
S
Shiozaki
H
H
Monden
M
M
D000704:Analysis of Variance; D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D004247:DNA / Q000737:chemistry / Q000235:genetics; D015536:Down-Regulation; D005786:Gene Expression Regulation; D008099:Liver / Q000737:chemistry / Q000378:metabolism*; D008297:Male; D009841:Oligonucleotides / Q000737:chemistry; D011488:Protein Deficiency / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D051381:Rats; D012709:Serum Albumin / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors / Q000032:analysis / Q000235:genetics* / Q000378:metabolism
D009841:Oligonucleotides; D012333:RNA, Messenger; D012709:Serum Albumin; D014157:Transcription Factors; D004247:DNA