Functional characterization of peroxisome proliferator-activated receptor (PPAR) in chickens -Regulation of PPAR gene expression in embryo and early growth stages and utilization for high quality animal products-

过氧化物酶体增殖激活受体（PPAR）是一种调节哺乳动物能量、脂质和糖代谢的转录因子。本研究旨在探讨鸡PPARs是否参与能量、脂质和糖代谢的调节，以及在胚胎和孵化后的雏鸡中是否可以通过修改PPARs基因的表达来构建高质量的动物生产。(1)鸡骨骼肌中ppar对解偶联蛋白及其辅助因子的调控avUCP和avANT在鸡线粒体能量代谢中起重要作用。冷驯化7d后，avUCP的表达随PGC-1α基因表达量的增加而增加。在饥饿条件下，PPARs和avANT基因表达呈线性增加，直至饥饿48h。这些结果表明，参与线粒体膜解偶联的因子（avUCP和avANT）是由ppar和/或这些共同作用的因子调控的。(2) PPARγ在鸡脂肪细胞分化中的生理作用目前的研究表明，PPARγ在脂肪酸诱导的鸡脂肪形成过程中是脂肪细胞分化的关键调节因子。PPARβ/δ对激活PPARγ诱导的鸡脂肪生成有刺激作用。因此，PPARs在鸡脂肪形成的调控中起着至关重要的作用。(3)给鸡PPARγ合成配体agonistTroglitazone改善胰岛素刺激下骨骼肌葡萄糖转运，通过调节骨骼肌葡萄糖转运改善对葡萄糖和胰岛素的耐受性，这些影响伴随着血浆脂联素和NEFA水平的变化。这些结果表明PPARγ参与了鸡的碳水化合物代谢。(4)利用PPAR激活雏鸡的高品质肉品生产系统。7周龄雏鸡单次腹腔注射PPARγ合成配体曲格列酮可减少脂肪沉积，提高饲料利用率。因此，调控和修改PPARs的表达和活性可能是高质量鸡肉生产的有用技术。少

Peroxisome proliferation-activated receptors (PPAR) are a transcription factor that modulates energy, lipid and glucose metabolism in mammals. The aim of the present study was to investigate whether chicken PPARs is involved in the regulation of energy, lipid and glucose metabolism and whether modification of th gene expression in embryo and post-hatched chicks is utilized to build the high-quality animal production.(1) Regulation of uncoupling protein and the co-factor by PPARs in chicken skeletal musclesIn chickens, avUCP and avANT play important roles of energy metabolism in mitochondria of chickens. The expression of avUCP was increased with the increase of PGC-1α gene expression under the cold acclimation for 7days. In the condition of starvation, PPARs and avANT gene expressions were lineally increased until 48h of starvations. These results suggested that the factors involved in the uncoupling of mitochondria membrane (avUCP and avANT) are regulated by PPARs and/or these co-fact … More ors.(2) Physiological function of PPARs in chicken adipocyte differentiationThe present studies showed that PPARγ is a key regulator of adipocyte differentiation during fatty acid-induced adipogensis in chickens. PPARβ/δ stimulated the chicken adipogenesis induced by activation of PPARγ. Thus, PPARs play a crucial role in the regulation of chicken adipogenesis.(3) Improvement in insulin-stimulated glucose transport in skeletal muscles of chickens administrated with PPARs agonistTroglitazone, a PPARγ synthetic ligand, improved tolerance to glucose and insulin administration through modulation of skeletal muscle glucose transport, with these effects being accompanied by changes in plasma adiponectin and NEFA levels. These results suggested that PPARγ is involved in the carbohydrate metabolism species-specific to chickens.(4) Development of high quality meat production system by activation of PPAR in post-hatched chicksThe single intraperitoneal administration of Troglitazone, a PPARγ synthetic ligand, to newly hatched chicks resulted the reduction of fat deposition and the increase of feed utilization in chickens at 7 week of age. It is, therefore, likely that the regulation and modification of PPARs expressions and activities might be useful technique for high-quality chicken meat production. Less