丙酸对肉牛肌内前脂肪细胞分化的影响  

Effects of Propionate on Differentiation of Bovine (Bos taurus) Intramuscular Preadipocytes

作　　者：万荣 周振明[2] 孟庆翔[2] WAN Rong;ZHOU Zhen-Ming;MENG Qing-Xiang(College of Agriculture and Food Engineering,Baise University,Baise 533000,China;College of Animal Science and Technology/Beef Cattle Research Center,China Agricultural University,Beijing 100193,China)

机构地区：[1]百色学院农业与食品工程学院,百色533000 [2]中国农业大学动物科技学院/肉牛研究中心,北京100193

出　　处：《农业生物技术学报》2021年第7期1295-1302,共8页Journal of Agricultural Biotechnology

基　　金：百色学院科研启动经费(DC2000002684)。

摘　　要：肌内脂肪是衡量牛肉品质的重要指标,肌内前脂肪细胞的分化对于大理石纹牛肉的形成至关重要。本研究旨在探究丙酸对肉牛(Bos taurus)肌内前脂肪细胞分化的影响,从细胞和分子水平解析肉牛肌内脂肪组织分化的信号机制。采用Ⅰ型胶原酶消化法分离获得牛肌内前脂肪细胞,设计不同剂量丙酸(1,3和6 mmol/L)、胰岛素(10μg/mL)和地塞米松(0.25μmol/L)的不同组合分化培养基,诱导培养肉牛肌内前脂肪细胞6 d。细胞内脂肪含量测定和qRT-PCR技术分析表明,丙酸呈剂量依赖性地增加肌内前脂肪细胞胞质内脂肪含量(P<0.05),1、3和6 mmol/L的丙酸均显著升高了肌内前脂肪细胞中PPARγ、C/EBPαmRNA的表达水平(P<0.05)。在丙酸、胰岛素和地塞米松都加入培养基时,培养的细胞胞质内脂肪含量最高,细胞中PPARγ、C/EBPαmRNA的表达水平最高。然而,当分别去掉胰岛素和地塞米松后,培养的细胞胞质内脂肪含量分别下降77%、85%,细胞中PPARγ、C/EBPαmRNA的表达显著降低(P<0.05)。而且,当从分化培养基中去除丙酸时,培养的细胞胞质内脂肪含量也降低了68%,细胞中PPARγ、C/EBPαmRNA的表达水平也显著降低(P<0.05)。以上结果表明,丙酸刺激肉牛肌内前脂肪细胞的分化可能是通过发挥类似激素(如胰岛素或地塞米松)的第一信使功能,作为信号分子通过信号转导机制达到刺激肌内前脂肪细胞的分化。本研究为阐明肉牛肌内脂肪的沉积机制,实现营养调控模式生产高档牛肉提供基础资料。Intramuscular fat is an important indicatior of beef quality, and preadipocyte differentiation is crucial for the formation of marbled beef. The purpose of this study was to explore the effect of propionic acid on the differentiation of intramuscular preadipocytes in bovine, and to analyze the signal mechanism of intramuscular preadipocyte differentiation from the cellular and molecular level. Bovine intramuscular preadipocytes were isolated by Collagenase Ⅰ under sterile conditions, differentiation medium with different combinations of different doses of propionate(1, 3 and 6 mmol/L), 0 μg/mL insulin and 0.25 μmol/L dexamethasonethe were designed to induce the differentiation of bovine intramuscular preadipocytes for 6 d.The results of determination of intracytoplasmic lipid contents and qRT-PCR analysis showed that, propionate significantly enhanced the intracytoplasmic lipid contents of bovine intramuscular preadipocytes in a dose dependent manner(P<0.05), and 1, 3 and 6 mmol/L significantly up-regulated the expression of PPARγ and C/EBPα m RNA of bovine intramuscular preadipocytes(P<0.05). The combination of propionate, insulin, and dexamethasone resulted in the greatest intracytoplasmic lipid content, whereas the removal of dexamethasone,insulin or propionate reduced intracytoplasmic lipid content by 85%, 77% and 68% respectively compared with the combination of propionate, insulin, and dexamethasone(P<0.05). Furthermore, the expression level of PPARγ and C/EBPα mRNA were decreased significantly(P<0.05). These results indicated that propionate may stimulate the differentiation of bovine intramuscular preadipocytes by acting as the first messenger of hormones(such as insulin or dexamethasone), and acting as a signal molecule through signal transduction mechanism. This study provides basic data for elucidating the deposition mechanism of intramuscular fat in beef cattle and realizing the nutritional regulation mode to produce high quality beef.

关 键 词：肉牛 肌内前脂肪细胞 分化 脂肪含量 丙酸 

分 类 号：S185[农业科学—农业基础科学]