TY - JOUR
T1 - Expression of the chicken peroxisome proliferator-activated receptor-γ gene is influenced by aging, nutrition, and agonist administration
AU - Sato, K.
AU - Fukao, K.
AU - Seki, Y.
AU - Akiba, Y.
PY - 2004/8
Y1 - 2004/8
N2 - Peroxisome proliferatior-activated receptor-γ (PPARγ) is a transcription factor that modulates lipid and glucose metabolism in mammals. The aim of the present study was to investigate whether chicken PPARγ is expressed in tissues in a similar manner to mammalian PPAR and whether it is involved in the regulation of lipid metabolism, particularly in the regulation of fat accumulation in adipose tissue and ovaries. In 30-wk-old chickens, PPARγ mRNA was detected in most tissues that were examined. Of those tissues expressing chicken PPARγ mRNA, the lowest expression levels were found in adipose tissue, the tissue that in mammals was shown to express the highest levels of PPARγ mRNA. Chicken PPARγ mRNA expression in abdominal adipose tissue tended to increase with age, as shown by higher expression levels at 6 wk than at 1 and 2 wk of age. With regard to nutritional modulation, PPARγ mRNA levels in abdominal adipose tissue were significantly higher in broiler chickens fed for 7 d a diet containing 8% safflower oil (18:2-rich) or linseed oil (18:3-rich) compared with chickens fed a diet containing olive oil (18:1-rich). In contrast, feeding a 3% cholesterol-supplemented diet for 7 d resulted in no changes to adipose PPARγ mRNA expression. In broiler chickens orally administered troglitazone, a PPARγ ligand, abdominal fat pad weight and PPARγ and lipoprotein lipase (LPL) mRNA levels were significantly increased relative to those of control chickens. Levels of PPARγ mRNA in liver, skeletal muscle, and ovaries were increased with the onset of egg laying, whereas in adipose tissue the level of PPARγ mRNA was decreased. These findings suggest that PPARγ plays an important role in the regulation of fat deposition and egg production and the characteristic pattern of PPARγ mRNA expression may be indicative of specific differences in the lipid and glucose metabolism of chickens compared with mammals.
AB - Peroxisome proliferatior-activated receptor-γ (PPARγ) is a transcription factor that modulates lipid and glucose metabolism in mammals. The aim of the present study was to investigate whether chicken PPARγ is expressed in tissues in a similar manner to mammalian PPAR and whether it is involved in the regulation of lipid metabolism, particularly in the regulation of fat accumulation in adipose tissue and ovaries. In 30-wk-old chickens, PPARγ mRNA was detected in most tissues that were examined. Of those tissues expressing chicken PPARγ mRNA, the lowest expression levels were found in adipose tissue, the tissue that in mammals was shown to express the highest levels of PPARγ mRNA. Chicken PPARγ mRNA expression in abdominal adipose tissue tended to increase with age, as shown by higher expression levels at 6 wk than at 1 and 2 wk of age. With regard to nutritional modulation, PPARγ mRNA levels in abdominal adipose tissue were significantly higher in broiler chickens fed for 7 d a diet containing 8% safflower oil (18:2-rich) or linseed oil (18:3-rich) compared with chickens fed a diet containing olive oil (18:1-rich). In contrast, feeding a 3% cholesterol-supplemented diet for 7 d resulted in no changes to adipose PPARγ mRNA expression. In broiler chickens orally administered troglitazone, a PPARγ ligand, abdominal fat pad weight and PPARγ and lipoprotein lipase (LPL) mRNA levels were significantly increased relative to those of control chickens. Levels of PPARγ mRNA in liver, skeletal muscle, and ovaries were increased with the onset of egg laying, whereas in adipose tissue the level of PPARγ mRNA was decreased. These findings suggest that PPARγ plays an important role in the regulation of fat deposition and egg production and the characteristic pattern of PPARγ mRNA expression may be indicative of specific differences in the lipid and glucose metabolism of chickens compared with mammals.
KW - Chicken
KW - Fat deposition
KW - Peroxisome proliferator-activated receptor-γ
KW - mRNA expression
UR - http://www.scopus.com/inward/record.url?scp=4444329610&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=4444329610&partnerID=8YFLogxK
U2 - 10.1093/ps/83.8.1342
DO - 10.1093/ps/83.8.1342
M3 - Article
C2 - 15339009
AN - SCOPUS:4444329610
SN - 0032-5791
VL - 83
SP - 1342
EP - 1347
JO - Poultry Science
JF - Poultry Science
IS - 8
ER -