Jiangsu Collaborative Innovation Center of Regional Modern Agriculture & Environmental Protection, Huaiyin Normal University, Huaian 223300, China.
Key Laboratory of Molecular Animal Nutrition, Ministry of Education, College of Animal Science, Zhejiang University, Hangzhou 310058, China.
Poult Sci. 2019 Apr 1;98(4):1842-1853. doi: 10.3382/ps/pey540.
The objective of this research was to examine the effects of prolactin (PRL) on the lipid synthesis of organ-cultured pigeon crops in vitro. In experiment 1, the histology, activities of enzymes, and expression of genes involved in metabolism and apoptosis of organ-cultured pigeon crops were analyzed over a 7-d culture period. The results showed that cultured crops maintained their structural integrity for up to 3 d in vitro. Beyond 3 d, caspase-3 activity and Bak1 gene expression increased with day of culture, whereas the activities of succinate dehydrogenase, Na+-K+-ATPase, Ca2+-Mg2+-ATPase, total ATPase, and gene expression of Bcl-2 and CK-19 diminished (P < 0.05). In experiment 2, the crops were cultured for 24, 36, and 48 h in medium containing 0, 25, or 50 ng/mL PRL, respectively, and the accumulation of lipid droplets, lipid content, and expression of fatty acid transportation- and lipogenesis-related genes were analyzed. The results showed that the crops with PRL supplements showed higher amounts of lipid droplets than those of the controls, and the droplets were mainly located in the basal nutritive layer in response to PRL. The efficacy of inducing lipid accumulation increased as the concentration of PRL increased. Crops with 50 ng/mL PRL incubated for 36 h displayed the maximal lipid content. Increasing the concentration of PRL from 0 to 50 ng/mL resulted in a dose-dependent increase in the expression of acetyl-CoA carboxylase, fatty acid synthase, fatty acid translocase, fatty acid binding protein 5, acyl-CoA binding protein, and peroxisome proliferator-activated receptor γ genes after incubation for 36 h (P < 0.05). Therefore, our results indicated that the organ-cultured pigeon crops maintained good viability for up to 3 d in vitro. Furthermore, PRL induced the lipid synthesis of organ-cultured pigeon crops in a dose- and time-dependent manner, which was related to the increased expression of genes involved in fatty acid transportation and lipogenesis.
本研究旨在探讨催乳素（PRL）对体外培养鸽嗉囊脂类合成的影响。在实验 1 中，我们分析了器官培养鸽嗉囊的组织学、代谢和细胞凋亡相关酶的活性以及基因表达情况，结果显示，体外培养的嗉囊在 3 天内可保持结构完整性，超过 3 天后，半胱氨酸天冬氨酸蛋白酶 3 （caspase-3）活性和 Bak1 基因表达增加，而琥珀酸脱氢酶、Na+-K+-ATP 酶、Ca2+-Mg2+-ATP 酶、总 ATP 酶和 Bcl-2 及 CK-19 的基因表达减少（P<0.05）。在实验 2 中，我们分别将嗉囊在含 0、25 或 50ng/mL PRL 的培养基中培养 24、36 和 48 小时，分析脂质滴的积累、脂质含量以及脂肪酸转运和脂肪生成相关基因的表达情况。结果表明，添加 PRL 的嗉囊比对照组有更多的脂质滴，这些脂质滴主要位于基础营养层，这是对 PRL 的响应。随着 PRL 浓度的增加，诱导脂质积累的效果增强。孵育 36 小时后，含 50ng/mL PRL 的嗉囊显示出最大的脂质含量。增加 PRL 浓度（0-50ng/mL）可导致乙酰辅酶 A 羧化酶、脂肪酸合酶、脂肪酸转运蛋白、脂肪酸结合蛋白 5、酰基辅酶 A 结合蛋白和过氧化物酶体增殖物激活受体 γ 基因在孵育 36 小时后的表达呈剂量依赖性增加（P<0.05）。因此，我们的结果表明，体外培养的鸽嗉囊在 3 天内保持良好的活力。此外，PRL 以剂量和时间依赖的方式诱导器官培养鸽嗉囊的脂类合成，这与脂肪酸转运和脂肪生成相关基因表达的增加有关。
