Expression of adiponectin and its receptors (AdipoR1 and AdipoR2) in chicken ovary: potential role in ovarian steroidogenesis

Adiponectin and its receptors (AdipoR1 and AdipoR2) mRNAs are expressed in various chicken tissues including ovary. However, the cellular expression and the role of adiponectin system have never been investigated in chicken ovary. Here, we have shown that the level of adiponectin mRNA is about 10- to 30-fold higher (p < 0.001) in theca cells than in granulosa cells from each hierarchical yellow follicle studied (F4–F1). In contrast, the level of AdipoR1 mRNA expression was about two-fold lower in theca cells than in granulosa cells (p < 0.05) whereas those of AdipoR2 was similar in both ovarian cells. Whereas expression of adiponectin mRNA increased with follicular differentiation in theca cells, it decreased in granulosa cells. In contrast, mRNA expression of AdipoR1 and AdipoR2 in both theca and granulosa cells remained stable during yellow follicle development. To determine whether adiponectin is involved in the ovarian steroidogenesis, LH (100 ng/ml)-, FSH (100 ng/ml)- and IGF-1 (100 ng/ml)-induced progesterone production was measured in absence or presence of human recombinant adiponectin (10 μg/ml) for 36 h in cultured granulosa cells from F1, F2 and mixed F3 and F4 follicles. In absence of LH, FSH and IGF-1, adiponectin treatment had no effects on progesterone production whatever vitollegenic follicle studied. However, it increased by about two-fold IGF-1-induced progesterone secretion in F2 and F3/4 follicles whereas it halved progesterone production in response to gonadotropins (LH and FSH) in F3/4 follicles. Thus, in chicken, adiponectin, mainly expressed in theca cells, could exert paracrine or autocrine effect on the ovarian steroidogenesis.     

Analysis of myostatin and its related factors in various porcine tissues

Myostatin is expressed in skeletal muscle tissue where it functions to suppress myoblast proliferation and myofiber hypertrophy. Recently, myostatin was detected in the tendon, mammary gland, and adipose tissue of mice. We sought to determine whether myostatin is expressed in the liver, spleen, lung, and kidney of pigs. Real-time PCR and Western blots demonstrated that myostatin, follistatin, decorin, and activin receptor IIB (ActRIIB) mRNA and proteins were expressed in skeletal muscle, heart muscle, and adipose tissue, and also in liver, spleen, lung, kidney, and cultured fibroblasts. The relative abundance of myostatin was closely related to follistatin and decorin in porcine tissues. Immunohistochemical analysis further demonstrated the presence of myostatin, follistatin, and decorin in the skeletal muscle, adipose tissue, heart muscle, liver, spleen, lung, and kidney of pigs. These results suggest that myostatin could be associated with certain functions of the internal organs, such as energy metabolism or fibrosis. We conclude that myostatin is a factor broadly expressed in the internal organs and muscle tissues of pigs.     

Fasting regulates the expression of adiponectin receptors in young growing pigs

Adiponectin is an adipocyte-derived hormone that can improve insulin sensitivity. Its functions in regulating glucose utilization and fatty acid metabolism in mammals are mediated by 2 subtypes of adiponectin receptors (AdipoR1 and AdipoR2). This study was conducted to determine the effect of fasting on the expression of adiponectin and its receptors. The expression of adiponectin was not affected in s.c. adipose tissue, but adiponectin expression increased in visceral adipose tissue after fasting. In contrast, expression of both AdipoR mRNA was increased in the liver and s.c. adipose tissue of 24-h-fasted pigs compared with fed pigs, but the mRNA in muscle and visceral adipose tissue was not affected by fasting. A third putative adiponectin receptor, T-cadherin, was cloned and the mRNA expression was determined. T-Cadherin has been recognized to act as a vascular adiponectin receptor in vascular endothelial and smooth muscle cells. Our data showed that the expression of T-cadherin was decreased in the muscle of fasted pigs, suggesting that the expression of T-cadherin can be regulated by feeding status. In summary, in young pigs, adiponectin mRNA was up-regulated by fasting in visceral, but not s.c., adipose tissue, whereas AdipoR1 and AdipoR2 mRNA were increased in s.c., but not visceral, adipose tissue. The adiponectin receptor, T-cadherin, was expressed in s.c. and visceral adipose tissue and in muscle, but only muscle mRNA expression was decreased by fasting.     

Characterisation of glucose transporter (GLUT) gene expression in broiler chickens

1. Glucose transporter (GLUT) proteins, one of which is the major insulin-responsive transporter GLUT4, play a crucial role in cellular glucose uptake and glucose homeostasis in mammals. The aim of this study was to identify the extent of mRNA expression of GLUT1, GLUT2, GLUT3 and GLUT8 in chickens intrinsically lacking GLUT4. 2. GLUT1 mRNA was detected in most tissues of 3-week-old broiler chickens, with the highest expression measured in brain and adipose tissue. GLUT2 was expressed only in the liver and kidney. GLUT3 was highly expressed in the brain. GLUT8 was expressed ubiquitously, with expression in kidney and adipose tissue relatively higher than that of other tissues. 3. Expression levels of GLUT isoforms 1, 3 and 8 in skeletal muscle tissue were very low compared to the other tissues tested. 4. [3H]Cytochalasin B binding assays on tissue from 3-week-old chickens showed that the number of cytochalasin B binding sites in skeletal muscle plasma membranes was higher than in liver plasma membranes. These results suggest that GLUT proteins and/or GLUT-like proteins that bind cytochalasin B are expressed in chicken skeletal muscles. 5. It is proposed that GLUT expression and glucose transport in chicken tissues are regulated in a manner different from that in mammals.     

秦川肉牛AdipoR1和AdipoR2基因克隆、生物信息学分析及表达研究

试验旨在利用生物信息学方法对秦川牛肉用新品系(以下简称“秦川肉牛”)AdipoR1、AdipoR2基因的CDS区进行克隆及分析,并探究其在秦川肉牛不同组织及肌细胞诱导分化不同时间的表达情况。以秦川肉牛为研究对象,经PCR扩增得到AdipoR1、AdipoR2基因CDS区序列,运用生物信息学软件对其功能结构进行预测,同时采用实时荧光定量PCR术获得AdipoR1、AdipoR2基因在秦川肉牛15个组织和诱导分化后不同时间的表达量,再进行差异分析。结果显示,秦川肉牛AdipoR1基因编码序列全长为1128 bp,编码375个氨基酸,蛋白分子质量为42446.41 u,理论等电点为6.70,AdipoR1蛋白二级结构主要由α-螺旋构成,二、三级结构预测结果一致,属于亲水性蛋白,没有信号肽位点;AdipoR2基因编码序列全长1161 bp,编码386个氨基酸,蛋白分子质量为43707.70 u,理论等电点为6.27。亚细胞定位结果表明,AdipoR1蛋白有60.9%的可能定位在细胞膜,AdipoR2蛋白有73.9%的可能定位在细胞膜。不同物种氨基酸系统进化树结果显示,秦川肉牛AdipoR1、AdipoR2基因编码的氨基酸序列分别与瘤牛和野牦牛的亲缘性最近。实时荧光定量PCR结果显示,AdipoR1、AdipoR2基因在秦川肉牛心脏、肝脏、肌肉等15个组织中均有表达,且在肌肉组织中的表达量最高,极显著高于其他组织(P<0.01),在肌细胞诱导分化时序上也有明显差异。本试验揭示了AdipoR1和AdipoR2基因在秦川肉牛不同组织和肌细胞诱导分化后不同时间上的表达差异,以期为进一步探究AdipoR1、AdipoR2基因的生物学功能与调控机理奠定基础。     

Long form leptin receptor mRNA expression in the brain, pituitary, and other tissues in the pig

Much effort has focused recently on understanding the role of leptin, the obese gene product secreted by adipocytes, in regulating growth and reproduction in rodents, humans and domestic animals. We previously demonstrated that leptin inhibited feed intake and stimulated growth hormone (GH) and luteinizing hormone (LH) secretion in the pig. This study was conducted to determine the location of long form leptin receptor (Ob-Rl) mRNA in various tissues of the pig. The leptin receptor has several splice variants in the human and mouse, but Ob-Rl is the major form capable of signal transduction. The Ob-Rl is expressed primarily in the hypothalamus of the human and rodents, but has been located in other tissues as well. In the present study, a partial porcine Ob-Rl cDNA, cloned in our laboratory and specific to the intracellular domain, was used to evaluate the Ob-Rl mRNA expression by RT-PCR in the brain and other tissues in three 105 d-old prepuberal gilts and in a 50 d-old fetus. In 105 d-old gilts, Ob-Rl mRNA was expressed in the hypothalamus, cerebral cortex, amygdala, thalamus, cerebellum, area postrema and anterior pituitary. In addition, Ob-Rl mRNA was expressed in ovary, uterine body, liver, kidney, pancreas, adrenal gland, heart, spleen, lung, intestine, bone marrow, muscle and adipose tissue. However, expression was absent in the thyroid, thymus, superior vena cava, aorta, spinal cord, uterine horn and oviduct. In the 50 d-old fetus, Ob-Rl mRNA was expressed in brain, intestine, muscle, fat, heart, liver and umbilical cord. These results support the idea that leptin might play a role in regulating numerous physiological functions.     

不同营养水平小尾寒羊体内AMPK表达调控的研究

本研究旨在通过免疫组织化学及Realtime PCR来研究不同营养水平条件下磷酸蛋白激酶AMPK和P-AMPK在小尾寒羊体内的分布情况及AMPKa亚基表达量的变化。研究结果表明,AMPKα亚基在下丘脑、肝、心、肾、脾、骨骼肌、十二指肠中分布,而P-AMPK在下丘脑、肝、心、肾、骨骼肌、十二指肠等组织中分布;低营养组AMPKαlmRNA相对表达量上调的组织有下丘脑、肝、心、骨骼肌、脂肪,禁食组AMPKαltaRNA相对表达量上调的组织有骨骼肌、脂肪。低营养组AMPKa2mRNA相对表达量上调的组织有下丘脑、心、骨骼肌、脂肪,禁食组AMPKa2mRNA相对表达量上调的组织有骨骼肌、脂肪、心、下丘脑。说明能量摄入水平对小尾寒羊体内AMPKαmRNA表达丰度有影响,并且AMPK对能量摄入水平的调节具有组织特畀性。     

Differential expression of peroxisome proliferator-activated receptors alpha and gamma gene in various chicken tissues

The peroxisome proliferator-activated receptors (PPARs) are the members of superfamily of nuclear hormone receptors. A great number of studies in rodent and human have shown that PPARs were involved in the lipids metabolism. The goal of the current study was to investigate the expression pattern of PPAR genes in various tissues of chicken. The tissue samples (heart, liver, spleen, lung, kidney, stomach, intestine, brain, breast muscle and adipose) were collected from six Arber Acres broilers (8 weeks old, male and female birds are half and half). Semi-quantitative RT-PCR and Northern blot were used to characterize the expression of PPAR-alpha and PPAR-gamma genes in the above tissues. By semi-quantitative RT-PCR, the results showed the expression level of PPAR-alpha gene was higher in brain, lung, kidney, heart and intestine, medium in stomach, liver and adipose than in spleen, and it did not express in breast muscle. The expression level of PPAR-gamma gene was higher in adipose, medium in brain and kidney than in spleen, heart, lung, stomach and intestine, but it did not express in liver and breast muscle. Northern blot results showed that PPAR-alpha gene expressed in heart, liver, kidney and stomach, and the intensity of hybridization signal was the stronger in liver and kidney than in other tissues, however, PPAR-gamma gene only expressed in adipose and kidney tissues. The results of this study showed the profile of PPAR gene expression in the chicken was similar to that in rodent, human and pig. However the expression profile of chicken also have its own specific trait, i.e. compared with mammals, PPAR-alpha gene can not be detected in skeletal muscle and PPAR-gamma gene can be stronger expressed in kidney tissues. This work will provide some basic data for the PPAR genes expression and lipids metabolism of birds.     

猪FoxO1基因cDNA部分序列的克隆及其组织表达

根据人、黑猩猩及大鼠等物种FoxO1基因同源序列设计引物,利用RT-PCR方法从猪肝脏中克隆FoxO1基因cDNA的部分序列,组织特异性表达分析表明,FoxO1基因在1日龄和9月龄猪的肝、肺、肾、脾、心、胃、皮下脂肪、内脏脂肪、背最长肌和股四头肌等组织中均表达,只是表达丰度随发育阶段和组织的不同有所差异。1日龄猪的内脏脂肪中FoxO1的表达丰度最高,心脏和骨骼肌中相对较低;而9月龄猪的脾脏中FoxO1相对表达丰度最高,明显高于免疫机能尚未完全建立的初生猪,显示出FoxO1可能在机体的免疫调节中起一定作用,另外,9月龄猪的FoxO1表达丰度不仅在平滑肌和骨骼肌中有显著差异,而且在不同类型的骨骼肌中也存在显著差异,显示出FoxO1的表达可能与骨骼肌类型和运动强度有关。     

Research Progress on Adiponectin and its Receptors and their Roles in Reproduction

Adiponectin is a special protein which is secreted by adipose tissue and has many kinds of biological functions that play an important role in enhancing fatty acid oxidation,inflammation reaction and anti diabetes ect.Adiponectin mediated by AdipoR1 and AdipoR2 via AMPK,PPAR,p38MAPK signal pathway plays an important role.Adiponectin and its receptors AdipoR1 and AdipoR2 express in many tissues,AdipoR1 is mainly expressed in muscle tissue,AdipoR2 is highly expressed in liver tissue.In addition,adiponectin and its receptors also expressed in the hypothalamus,pituitary,uterus,embryo and other reproductive glands and tissues,which indicate that adiponectin plays an important role in regulating animal reproduction and embryo growth and development.     

脂联素及其受体的研究进展及在生殖中的作用

脂联素是一种由脂肪组织分泌的具有多种生物学功能的特殊蛋白,在增强脂肪酸氧化、抗炎症反应、抗糖尿病等方面起重要作用。脂联素通过AdipoR1和AdipoR2这两种受体的介导经过AMPK、PPAR、p38MAPK等信号通路来发挥生物学作用。脂联素及其受体AdipoR1和AdipoR2能在多种组织器官中表达,AdipoR1主要在肌肉组织中表达,AdipoR2则高表达于肝脏组织。此外,脂联素及其受体还能在下丘脑、垂体、子宫、胚胎等多种生殖腺和生殖组织中表达,说明脂联素在调控动物生殖及胚胎生长发育方面起重要作用。     

NPY、TSH-β、CaBP-28K基因在鸭繁殖期组织中的表达水平分析

本研究对繁殖期高邮鸭神经肽Y(NPY)、促甲状腺激素β(TSH-β)、钙结合蛋白-D28K(CaBP-28K)基因在中枢神经组织和周围组织表达量进行了实时荧光定量分析。结果表明:NPY基因在下丘脑中表达量显著高于在垂体和在小肠中的表达量(P<0.05),在卵巢、心脏、肝脏、脾脏、肾脏、胰腺、子宫、胸肌、腿肌等9个部位呈痕量表达;TSH-β基因在垂体、小肠中表达量较高,显著高于其他组织(P<0.05);CaBP-28K基因在小肠表达量最多,其次是卵巢和肾脏,但均显著大于垂体中表达量(P<0.05),在其他测定部位呈痕量表达,就生殖轴而言,CaBP-28KmRNA的表达量表现为卵巢>垂体>下丘脑。本研究为了解高邮鸭繁殖期相关基因的表达特征和内分泌机制,指导高邮鸭选种选育提供了理论依据。     

秦川肉牛AdipoR1和AdipoR2基因克隆、生物信息学分析及表达研究

试验旨在利用生物信息学方法对秦川牛肉用新品系（以下简称"秦川肉牛"）AdipoR1、AdipoR2基因的CDS区进行克隆及分析，并探究其在秦川肉牛不同组织及肌细胞诱导分化不同时间的表达情况。以秦川肉牛为研究对象，经PCR扩增得到AdipoR1、AdipoR2基因CDS区序列，运用生物信息学软件对其功能结构进行预测，同时采用实时荧光定量PCR术获得AdipoR1、AdipoR2基因在秦川肉牛15个组织和诱导分化后不同时间的表达量，再进行差异分析。结果显示，秦川肉牛AdipoR1基因编码序列全长为1 128 bp，编码375个氨基酸，蛋白分子质量为42 446.41 u，理论等电点为6.70，AdipoR1蛋白二级结构主要由α-螺旋构成，二、三级结构预测结果一致，属于亲水性蛋白，没有信号肽位点；AdipoR2基因编码序列全长1 161 bp，编码386个氨基酸，蛋白分子质量为43 707.70 u，理论等电点为6.27。亚细胞定位结果表明，AdipoR1蛋白有60.9%的可能定位在细胞膜，AdipoR2蛋白有73.9%的可能定位在细胞膜。不同物种氨基酸系统进化树结果显示，秦川肉牛AdipoR1、AdipoR2基因编码的氨基酸序列分别与瘤牛和野牦牛的亲缘性最近。实时荧光定量PCR结果显示，AdipoR1、AdipoR2基因在秦川肉牛心脏、肝脏、肌肉等15个组织中均有表达，且在肌肉组织中的表达量最高，极显著高于其他组织（P<0.01），在肌细胞诱导分化时序上也有明显差异。本试验揭示了AdipoR1和AdipoR2基因在秦川肉牛不同组织和肌细胞诱导分化后不同时间上的表达差异，以期为进一步探究AdipoR1、AdipoR2基因的生物学功能与调控机理奠定基础。     

猪PPARs基因组织表达特性的研究

以成年母猪为研究材料,采用RT-PCR半定量法对猪PPARα、β/δ和γ基因组织表达特点进行了研究。结果表明:在检测的18种组织中除胰腺组织外,3种PPAR亚型在其他17种组织中均有表达。表达量高低依次为PPARα,子宫绒毛膜>皮下脂肪>卵巢>大肠>脾脏>大脑>肾上腺>心脏>肺>小肠>脊髓>子宫蜕膜>胃>肝脏>背最长肌>膀胱>肾脏;PPARδ,子宫绒毛膜>卵巢>大肠>脾脏>肝脏>胃>皮下脂肪>大脑>肺>肾上腺>子宫蜕膜>脊髓>背最长肌>心脏>肾脏>小肠>膀胱;PPARγ,背最长肌>皮下脂肪>卵巢>脾脏>肺>大肠>膀胱>子宫绒毛膜>子宫蜕膜>心脏>胃>肝脏>肾脏>大脑>脊髓>肾上腺>小肠。3种亚型PPAR在卵巢和/或子宫绒毛膜中都有较高的表达,提示它们与猪的繁殖性能相关。