-
[show abstract]
[hide abstract]
ABSTRACT: Background: Phosphatase and tensin homolog (PTEN) is a potent tumor suppressor gene that also plays a vital role in regulating fatty acid metabolism. Here we attempted to elucidate the role of PTEN in the regulation of fatty acid oxidation and the assembly and secretion of very low density lipoprotein (VLDL) in dairy cow liver. Methods: We transfected primary culture calf hepatocytes with adenovirus-mediated PTEN overexpression vector (AD-GFP-PTEN).PTEN-overexpressing hepatocytes and control hepatocytes were obtained. Results: Compared with controls, overexpression of PTEN significantly up-regulated CPT I, ACSL, HADH expression (p<0.05), which are all involved in fatty acid oxidation. At the same time, the expression of ApoB100 (p<0.01), ApoE (p<0.05) and MTP (p<0.01) increased. Therefore, the assembly and secretion of VLDL was enhanced (p<0.05). The expression of LDLR was slightly up-regulated, but there was no significant difference (p>0.05). To demonstrate that fatty acid metabolism was changed, we measured the concentrations of TG and VLDL. The concentration of TG was significantly decreased in hepatocytes (p<0.01), while the concentration of VLDL was significantly increased in the medium (P<0.05). Conclusions: Overexpressing PTEN enhanced fatty acid oxidation and assembly and secretion of VLDL. PTEN gene therapy could have therapeutic potential for fatty liver diseases of dairy cattle.
Cellular Physiology and Biochemistry 09/2012; 30(4):1005-1013. · 2.86 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Red-colored bones were first found in Guishan goats in the 1980s, and they were subsequently designated red-boned Guishan goats. However, the difference remains unclear between the bone mineral density (BMD) or elemental composition in bones between red-boned Guishan goats and common Guishan goats. Analysis of femoral bone samples by dual-energy X-ray absorptiometry and inductively coupled plasma optical emission spectrometry revealed an increase in bone mineral density in the femoral diaphysis and distal femur of red-boned Guishan goats at 18 and 36 months of age. The data revealed that BMD increased in both the red-boned and common Guishan goats from 18 to 36 months of age. The data also indicated that the ratio of the BMD values of red-boned to common Guishan goats was higher at 36 months of age than they were at 18 months of age. Furthermore, the levels of calcium, phosphorus, magnesium, barium, zinc, manganese, and aluminum were significantly higher in red-boned Guishan goats than common Guishan goats at 18 and 36 months of age. The results indicate that the red-boned Guishan goats were linked to the elevated levels of mineral salts observed in the bones and that this in turn may be linked to the elevated BMD levels encountered in red-boned Guishan goats. These reasons may be responsible for the red coloration in the bones of red-boned Guishan goats.
Biological trace element research 05/2012; · 1.92 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The major role of insulin-like growth factor-1 (IGF-1) in the liver is to mediate glucose uptake in hepatocytes to synthesize glycogen and maintain blood glucose homeostasis. In this study, to evaluate the role of IGF-1 on gluconeogenesis and nutrient metabolism in dairy cattle, pyruvate carboxylase (PC) and phosphoenolpyruvate carboxykinase (PEPCK) expression and enzyme activity were evaluated in primary cultures of bovine hepatocytes treated with different concentrations of IGF-1 by quantitative polymerase chain reaction and spectrophotometry, respectively. The results showed that expression of PC and PEPCK were significantly lower in bovine hepatocytes by IGF-1 treatment in test group compare to the control group (P < 0.01). As IGF-1 concentration increased, PC and PEPCK enzyme activity in bovine hepatocytes decreased. Evaluating PC and PEPCK mRNA levels and enzyme activity may thus be useful to monitor subclinical ketosis in dairy cows.
Molecular and Cellular Biochemistry 03/2012; 362(1-2):87-91. · 2.06 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Red-colored bones were found initially in some Guishan goats in the 1980s, and they were designated red-boned goats. However, it is not understood what causes the red color in the bone, or whether the red material changes the bone geometry, architecture, and metabolism of red-boned goats. Pseudopurpurin was identified in the red-colored material of the bone in red-boned goats by high-performance liquid chromatography-electrospray ionization-mass spetrometry and nuclear magnetic resonance analysis. Pseudopurpurin is one of the main constituents of Rubia cordifolia L, which is eaten by the goats. The assessment of the mechanical properties and micro-computed tomography showed that the red-boned goats displayed an increase in the trabecular volume fraction, trabecular thickness, and the number of trabeculae in the distal femur. The mean thickness, inner perimeter, outer perimeter, and area of the femoral diaphysis were also increased. In addition, the trabecular separation and structure model index of the distal femur were decreased, but the bone mineral density of the whole femur and the mechanical properties of the femoral diaphysis were enhanced in the red-boned goats. Meanwhile, expression of alkaline phosphatase and osteocalcin mRNA was higher, and the ratio of the receptor activator of the nuclear factor kappa B ligand to osteoprotegerin was markedly lower in the bone marrow of the red-boned goats compared with common goats. To confirm further the effect of pseudopurpurin on bone geometry, architecture, and metabolism, Wistar rats were fed diets to which pseudopurpurin was added for 5 months. Similar changes were observed in the femurs of the treated rats. The above results demonstrate that pseudopurpurin has a close affinity with the mineral salts of bone, and consequently a high level of mineral salts in the bone cause an improvement in bone strength and an enhancement in the structure and metabolic functions of the bone.
PLoS ONE 01/2012; 7(5):e37469. · 4.09 Impact Factor
-
Zhigang Zhang,
Xiaobing Li,
Hongbin Wang,
Changming Guo,
Li Gao,
Lei Liu,
Ruifeng Gao,
Yi Zhang, Peng Li,
Zhe Wang,
Yanfei Li,
Guowen Liu
[show abstract]
[hide abstract]
ABSTRACT: Serum concentrations of sodium, potassium, magnesium, and iron were measured in dairy cows with subclinical ketosis. Compared with healthy cows, the subclinically ketotic cows had significantly higher levels of non-esterified fatty acids and β-hydroxybutirate in serum and significantly lower levels of blood glucose (p < 0.01). No significant differences were observed, suggesting that the mineral elements measured are not involved in the pathogenesis of subclinical ketosis.
Biological trace element research 07/2011; 144(1-3):525-8. · 1.92 Impact Factor
