Molecular Characterization of Goose Phosphoenolpyruvate Carboxylase Kinase 1 (Pepck) Gene and Its Potential Role in Hepatic Steatosis Induced by Overfeeding

Over-accumulation of triglycerides (TGs) in goose hepatocytes leads to the formation of fatty acid liver. Phosphoenolpyruvate carboxylase kinase 1 (PEPCK) is regarded as the rate-limiting enzyme for gluconeogenesis, and there is evidence that PEPCK is involved in regulating hepatic glucolipid metabolism. Hence, we proposed that PEPCK may have a role in goose hepatic steatosis. To test our hypothesis, the present study was conducted to firstly determine the sequence characteristics of goose PEPCK and then to explore its role in overfeeding-induced fatty liver. Our results showed that goose PEPCK encodes a 622-amino-acids protein that contains highly conserved oxaloacetate-binding domain, kinase-1 and kinase-2 motifs. PEPCK had higher mRNA levels in goose liver, and overfeeding markedly increased its expression in livers of both Sichuan White and Landes geese (p 0.05). Besides, expression of PEPCK was positively correlated with hepatic TG levels as well as plasma glucose and insulin concentrations. Additionally, in cultured goose primary hepatocyte, treatment with either oleic acid (0.8, 1.2 or 1.6 mM) or linoleic acid (0.125 or 0.25 mM) significantly (p 0.05) enhanced the expression of PEPCK. Taken together, these data suggested a role for PEPCK in the occurrence of overfeeding-induced goose hepatic steatosis.(AU)

Molecular Characterization of Goose Phosphoenolpyruvate Carboxylase Kinase 1 (Pepck) Gene and Its Potential Role in Hepatic Steatosis Induced by Overfeeding

Over-accumulation of triglycerides (TGs) in goose hepatocytes leads to the formation of fatty acid liver. Phosphoenolpyruvate carboxylase kinase 1 (PEPCK) is regarded as the rate-limiting enzyme for gluconeogenesis, and there is evidence that PEPCK is involved in regulating hepatic glucolipid metabolism. Hence, we proposed that PEPCK may have a role in goose hepatic steatosis. To test our hypothesis, the present study was conducted to firstly determine the sequence characteristics of goose PEPCK and then to explore its role in overfeeding-induced fatty liver. Our results showed that goose PEPCK encodes a 622-amino-acids protein that contains highly conserved oxaloacetate-binding domain, kinase-1 and kinase-2 motifs. PEPCK had higher mRNA levels in goose liver, and overfeeding markedly increased its expression in livers of both Sichuan White and Landes geese (p 0.05). Besides, expression of PEPCK was positively correlated with hepatic TG levels as well as plasma glucose and insulin concentrations. Additionally, in cultured goose primary hepatocyte, treatment with either oleic acid (0.8, 1.2 or 1.6 mM) or linoleic acid (0.125 or 0.25 mM) significantly (p 0.05) enhanced the expression of PEPCK. Taken together, these data suggested a role for PEPCK in the occurrence of overfeeding-induced goose hepatic steatosis.

Effects of Vitamin E Supplementation on Serum Hormones and Gene Expression of Anti-season Breeding Xingguo Grey Geese (Anser cygnoides)

The objective of this study was to analyse the impact of dietary vitamin E supplementation on laying performance, serum reproductive hormones concentration and gene expression in ovary and follicles of anti-season breeding goose. A total of 210 anti-season breeding geese were divided into seven treatments with six replications. Each group was supplied with diets containing different vitamin E (DL--tocopherol acetate) contents (0, 10, 20, 40, 80, 160, 320mg/kg). We observed that the egg production and laying rate improved significantly at doses of 10 and 80 mg/kg, while the highest egg weight appeared in the 320 mg/kg group. Meantime, 80 mg/kg of vitamin E supplementation significantly improved the concentration of follicle-stimulating hormone (FSH), luteinizing hormone (LH) and estradiol (E2) in serum (p 0.05). Dietary vitamin E supplementation significantly enhanced mRNA expression of FSHR, LHR and ESR1 at a dose of 80mg/kg, while PRLR increased at doses of 10 and 20mg/kg (p 0.05). It was found that the mRNA expression of Dicer increased at doses of 40 and 80 mg/kg of vitamin E supplementation in the ovary, SWF, LWF and SYF, respectively. Thence, Dietary vitamin E supplementation could improve egg laying performance, plasma reproductive hormones and the mRNA expression of reproductive hormone receptor genes in ovary, as well as the mRNA expression of Dicer in ovary, SWF, LWF and SYF. It was supposed that 80 mg/kg of vitamin E supplementation in dietary was appropriate to improve the fertility of anti-season breeding Xingguo grey goose.(AU)

Effects of Vitamin E Supplementation on Serum Hormones and Gene Expression of Anti-season Breeding Xingguo Grey Geese (Anser cygnoides)

The objective of this study was to analyse the impact of dietary vitamin E supplementation on laying performance, serum reproductive hormones concentration and gene expression in ovary and follicles of anti-season breeding goose. A total of 210 anti-season breeding geese were divided into seven treatments with six replications. Each group was supplied with diets containing different vitamin E (DL--tocopherol acetate) contents (0, 10, 20, 40, 80, 160, 320mg/kg). We observed that the egg production and laying rate improved significantly at doses of 10 and 80 mg/kg, while the highest egg weight appeared in the 320 mg/kg group. Meantime, 80 mg/kg of vitamin E supplementation significantly improved the concentration of follicle-stimulating hormone (FSH), luteinizing hormone (LH) and estradiol (E2) in serum (p 0.05). Dietary vitamin E supplementation significantly enhanced mRNA expression of FSHR, LHR and ESR1 at a dose of 80mg/kg, while PRLR increased at doses of 10 and 20mg/kg (p 0.05). It was found that the mRNA expression of Dicer increased at doses of 40 and 80 mg/kg of vitamin E supplementation in the ovary, SWF, LWF and SYF, respectively. Thence, Dietary vitamin E supplementation could improve egg laying performance, plasma reproductive hormones and the mRNA expression of reproductive hormone receptor genes in ovary, as well as the mRNA expression of Dicer in ovary, SWF, LWF and SYF. It was supposed that 80 mg/kg of vitamin E supplementation in dietary was appropriate to improve the fertility of anti-season breeding Xingguo grey goose.

Effects of Dietary Energy Concentration on Reproductive Hormone Secretion and Gene Expression in the Hypothalamus-Pituitary-Gonad Axis in Laying Geese

The objective of the study was to investigate the mechanism by which dietary energy concentration regulates laying performance in geese. Eighty 558-day-old female Sichuan White geese were randomly allotted to two dietary treatments, each treatment was fed 1 of 2 experimental diets containing 10.00 (deficient) or 11.80MJ/kg metabolizable energy (sufficient) for 30 days. Laying performance, hormone concentration and gene expressions in hypothalamus-pituitary-gonadal axis were examined in geese. Birds fed the sufficient-energy diet had significantly higher average egg weight, daily laying rate, and lower feed to egg ratio than those fed the deficient-energy (p 0.05). The birds fed sufficient-energy diet had higher concentration of serum insulin like growth factor 1 (IGF-1), gonadotropin-releasing hormone (GnRH), follicle-stimulating hormone (FSH) and estradiol (E2) than those in deficient-energy diet (p 0.05). The mRNA expression levels of GnRH in the hypothalamus, FSH in the pituitary and E2 in the ovary of birds fed sufficient-energy diet were higher than the corresponding counterpart in deficient-energy diet (p 0.05), respectively. In conclusion, the study implied that dietary energy modifies laying possibly through regulating reproductive hormone secretion and gene expression in hypothalamus-pituitary-gonad axis in laying geese.(AU)

Effects of Dietary Energy Concentration on Reproductive Hormone Secretion and Gene Expression in the Hypothalamus-Pituitary-Gonad Axis in Laying Geese

The objective of the study was to investigate the mechanism by which dietary energy concentration regulates laying performance in geese. Eighty 558-day-old female Sichuan White geese were randomly allotted to two dietary treatments, each treatment was fed 1 of 2 experimental diets containing 10.00 (deficient) or 11.80MJ/kg metabolizable energy (sufficient) for 30 days. Laying performance, hormone concentration and gene expressions in hypothalamus-pituitary-gonadal axis were examined in geese. Birds fed the sufficient-energy diet had significantly higher average egg weight, daily laying rate, and lower feed to egg ratio than those fed the deficient-energy (p 0.05). The birds fed sufficient-energy diet had higher concentration of serum insulin like growth factor 1 (IGF-1), gonadotropin-releasing hormone (GnRH), follicle-stimulating hormone (FSH) and estradiol (E2) than those in deficient-energy diet (p 0.05). The mRNA expression levels of GnRH in the hypothalamus, FSH in the pituitary and E2 in the ovary of birds fed sufficient-energy diet were higher than the corresponding counterpart in deficient-energy diet (p 0.05), respectively. In conclusion, the study implied that dietary energy modifies laying possibly through regulating reproductive hormone secretion and gene expression in hypothalamus-pituitary-gonad axis in laying geese.

The effect of hydrated sodium calcium aluminosilicate on fatty liver and the composition of the intestinal microbiota in overfed landes geese

Goose fatty liver is a delicious food product and the overfeeding will cause the abnormal physiology of the geese. The objective of this study was to investigate the effect of supplementation with hydrated sodium calcium aluminosilicate (HSCAS) on the fatty liver, ileal and cecal microbiota of Landes geese during overfeeding. Sixty 70-day-old Landes geese (body weight= 3.0 ± 0.05 kg) were randomly divided into three groups, two of which were overfed with whole corn supplemented with or without HSCAS for 20 days when the fatty liver reaches to the maximum size and the negative control group was ad libitum access to the corn basal diet. The intestinal contents of the ileum and cecum from three geese per group were used for high-throughput sequencing. As a result of this study, the HSCAS-treatment led to an increase in relative liver weight (p 0.05) of geese compared with the overfeeding control group. The richness and diversity of the bacterial communities decreased in the ileum and ceca after overfeeding. Overfeeding increased the relative abundance of Firmicutes, especially Lactobacillus, in ileal samples. HSCAS supplementation increased the relative abundance of Lactobacillus, and decreased the relative abundance of Actinobacillus in the ileum and the relative abundance of Erysipelotrichi, Bacteroides and Escherichia in the ceca. Bacterial richness indicators were also increased in samples from ileum and ceca after HSCAS supplementation. In conclusion, dietary HSCAS supplementation promoted liver performance in overfed Landes geese. HSCAS treatment had a beneficial effect on the intestinal microbiota composition in geese during the overfeeding.(AU)

The effect of hydrated sodium calcium aluminosilicate on fatty liver and the composition of the intestinal microbiota in overfed landes geese

Goose fatty liver is a delicious food product and the overfeeding will cause the abnormal physiology of the geese. The objective of this study was to investigate the effect of supplementation with hydrated sodium calcium aluminosilicate (HSCAS) on the fatty liver, ileal and cecal microbiota of Landes geese during overfeeding. Sixty 70-day-old Landes geese (body weight= 3.0 ± 0.05 kg) were randomly divided into three groups, two of which were overfed with whole corn supplemented with or without HSCAS for 20 days when the fatty liver reaches to the maximum size and the negative control group was ad libitum access to the corn basal diet. The intestinal contents of the ileum and cecum from three geese per group were used for high-throughput sequencing. As a result of this study, the HSCAS-treatment led to an increase in relative liver weight (p 0.05) of geese compared with the overfeeding control group. The richness and diversity of the bacterial communities decreased in the ileum and ceca after overfeeding. Overfeeding increased the relative abundance of Firmicutes, especially Lactobacillus, in ileal samples. HSCAS supplementation increased the relative abundance of Lactobacillus, and decreased the relative abundance of Actinobacillus in the ileum and the relative abundance of Erysipelotrichi, Bacteroides and Escherichia in the ceca. Bacterial richness indicators were also increased in samples from ileum and ceca after HSCAS supplementation. In conclusion, dietary HSCAS supplementation promoted liver performance in overfed Landes geese. HSCAS treatment had a beneficial effect on the intestinal microbiota composition in geese during the overfeeding.

Gene Expression Patterns of Geese Expression Patterns of L-FABP, Spot 14, OB and APO A1 Genes in Different Tissues of Overfed and Control Geese

Ten-week-old Langde geese in similar body weight were randomly selected, four for overfeeding and four for routinly feeding. The abundance of liver fatty acid-binding protein (L-FABP), thyroid hormone-responsive (THRSP or Spot 14), obese (OB), and apolipoprotein A1 (Apo A1) genes in goose were detected by quantitative RT-PCR. L-FABP was higher expressed in liver and intestine than other tissues, but no expression was detected in the pancreas or brain. The other three genes were widely expressed in different tissues, OB was higher expressed in pancreas and abdominal fat, Spot 14 and Apo A1 was higher expressed in sebum and abdominal fat. Spot 14 and Apo A1 genes were up-regulated in overfed goose livers compared with that in the control. Thus, Spot 14 and Apo A1 genes may play important roles in lipid metabolism in goose fat liver.(AU)

Gene Expression Patterns of Geese Expression Patterns of L-FABP, Spot 14, OB and APO A1 Genes in Different Tissues of Overfed and Control Geese

Ten-week-old Langde geese in similar body weight were randomly selected, four for overfeeding and four for routinly feeding. The abundance of liver fatty acid-binding protein (L-FABP), thyroid hormone-responsive (THRSP or Spot 14), obese (OB), and apolipoprotein A1 (Apo A1) genes in goose were detected by quantitative RT-PCR. L-FABP was higher expressed in liver and intestine than other tissues, but no expression was detected in the pancreas or brain. The other three genes were widely expressed in different tissues, OB was higher expressed in pancreas and abdominal fat, Spot 14 and Apo A1 was higher expressed in sebum and abdominal fat. Spot 14 and Apo A1 genes were up-regulated in overfed goose livers compared with that in the control. Thus, Spot 14 and Apo A1 genes may play important roles in lipid metabolism in goose fat liver.

Molecular Cloning and Mrna Expression Analysis of Sichuan White Goose (Anser Cygnoides) Chrebp Gene

The carbohydrate response element-binding protein (ChREBP) is an important nuclear factor that regulates glycolysis and de novo lipogenesis. However, the role of ChREBP in fatty liver development in geese remains unclear. In order to understand the function of ChREBP in lipid metabolism of geese, we first cloned the complete cDNA of the ChREBP of the Sichuan White goose (Anser cygnoides) using RT-PCR, 5 RACE and 3 RACE, and analyzed goose ChREBP expression in nine different tissues using real-time PCR technology. The results showed that the goose ChREBP CDS consists of 945bp nucleotides that encode 314 amino acids, and the sequence has high similarities with the swan goose (Anser cygnoides domesticus) and duck (Anas platyrhynchos) sequences, both at the nucleotide and amino acid levels. The predicted ChREBP protein had a molecular mass of 35.64 kDa with pI value of 5.36. The phylogenetic analysis indicated its evolutionary relationships with corresponding orthologous sequences in swan geese and ducks. The qPCR assays revealed that ChREBP is highly expressed in liver in the Sichuan White goose. Together, these results indicate that goose ChREBP may play an important role in the development of hepatic steatosis.(AU)

Molecular Cloning and Mrna Expression Analysis of Sichuan White Goose (Anser Cygnoides) Chrebp Gene

The carbohydrate response element-binding protein (ChREBP) is an important nuclear factor that regulates glycolysis and de novo lipogenesis. However, the role of ChREBP in fatty liver development in geese remains unclear. In order to understand the function of ChREBP in lipid metabolism of geese, we first cloned the complete cDNA of the ChREBP of the Sichuan White goose (Anser cygnoides) using RT-PCR, 5 RACE and 3 RACE, and analyzed goose ChREBP expression in nine different tissues using real-time PCR technology. The results showed that the goose ChREBP CDS consists of 945bp nucleotides that encode 314 amino acids, and the sequence has high similarities with the swan goose (Anser cygnoides domesticus) and duck (Anas platyrhynchos) sequences, both at the nucleotide and amino acid levels. The predicted ChREBP protein had a molecular mass of 35.64 kDa with pI value of 5.36. The phylogenetic analysis indicated its evolutionary relationships with corresponding orthologous sequences in swan geese and ducks. The qPCR assays revealed that ChREBP is highly expressed in liver in the Sichuan White goose. Together, these results indicate that goose ChREBP may play an important role in the development of hepatic steatosis.

Change of the mtor pathway in tissues of overfed geese

This study aimed at examining the effect of overfeeding on the activity of the mTOR pathway in the liver and muscle tissues of Gang geese. Eighty healthy male Gang geese were reared under the same feeding conditions, and were divided at 14 weeks of age into a control group and an overfed group. All birds were slaughtered after three weeks of over feeding. Gene expression and protein content of several genes involved in the mTOR pathway were evaluated. The results showed that the gene expression of mTOR, raptor, and rictor, and the protein contents of mTOR and PI3K were higher in liver, breast muscle, and leg muscle of the overfed group than that of control group. However, the S6K expression level was clearly lower in the liver of the overfed group than that of control group, and there was no evident difference in both breast muscle and leg muscle between the control group and the overfed group. These results suggest that overfeeding induces the activity of raptor, rictor, and mTOR, and that mTOR signaling pathway was closely linked with PI3K pathway in the evaluated geese.(AU)

Change of the mtor pathway in tissues of overfed geese

This study aimed at examining the effect of overfeeding on the activity of the mTOR pathway in the liver and muscle tissues of Gang geese. Eighty healthy male Gang geese were reared under the same feeding conditions, and were divided at 14 weeks of age into a control group and an overfed group. All birds were slaughtered after three weeks of over feeding. Gene expression and protein content of several genes involved in the mTOR pathway were evaluated. The results showed that the gene expression of mTOR, raptor, and rictor, and the protein contents of mTOR and PI3K were higher in liver, breast muscle, and leg muscle of the overfed group than that of control group. However, the S6K expression level was clearly lower in the liver of the overfed group than that of control group, and there was no evident difference in both breast muscle and leg muscle between the control group and the overfed group. These results suggest that overfeeding induces the activity of raptor, rictor, and mTOR, and that mTOR signaling pathway was closely linked with PI3K pathway in the evaluated geese.