›› 2018, Vol. 61 ›› Issue (8): 895-904.doi: 10.16380/j.kcxb.2018.08.002

• 研究论文 • 上一篇    下一篇

饥饿胁迫对家蚕糖脂代谢的影响及BmFoxO的作用

孟竹, 文茂羽, 康晓丽, 卢忠燕*, 赵萍, 夏庆友   

  1.  (西南大学生物技术学院, 家蚕基因组生物学国家重点实验室, 重庆 400716)
  • 出版日期:2018-08-20 发布日期:2018-08-20

Effects of starvation stress on the glucose and lipid metabolism and the role of BmFoxO in Bombyx mori

MENG Zhu, WEN Mao-Yu, KANG XiaoLi, LU Zhong-Yan*, ZHAO Ping, XIA Qing-You    

  1.  (State Key Laboratory of Silkworm Genome Biology, School of Biotechnology, Southwest University, Chongqing 400716, China)
  • Online:2018-08-20 Published:2018-08-20

摘要:  【目的】饥饿是生物体在其发育周期中经历的主要压力源之一。本研究旨在了解饥饿胁迫后家蚕Bombyx mori糖脂代谢的变化,并探讨叉头框转录因子O亚族(forkhead box transcription factor O, FoxO)基因在其中的作用。【方法】选用家蚕5龄第2日幼虫进行连续饥饿处理72 h,每隔12 h测定脂肪体中甘油三酯和糖原的含量以及血淋巴中海藻糖的浓度;利用荧光定量PCR技术检测脂肪体中脂质代谢相关基因以及胰岛素通路中BmFoxO基因、胰岛素受体(insulin receptor, InR)基因和蛋白激酶B(protein kinase B, Akt)基因的表达量变化。构建增量表达BmFoxO的载体,转染BmE细胞,荧光定量PCR检测BmE细胞中糖脂代谢相关基因的表达情况。【结果】在连续饥饿的72 h内家蚕幼虫脂肪体中糖原和甘油三酯的含量持续降低,在饥饿48-72 h之间血淋巴中海藻糖浓度升高。荧光定量PCR结果显示,家蚕在受到饥饿胁迫后脂肪体中脂质分解代谢基因和胰岛素通路中BmFoxO, InRAkt表达量显著增加,因此导致家蚕脂类分解增强。在BmE细胞中增量表达BmFoxO后,检测到BmFoxO, InRAkt基因的表达变化趋势与饥饿处理家蚕后的结果相似。【结论】BmFoxO可以调控家蚕体内的糖脂代谢,并参与家蚕对饥饿的抵抗。本研究为进一步研究BmFoxO在家蚕个体生长代谢方面的功能奠定了基础。

关键词: 家蚕, BmFoxO, 饥饿胁迫, 糖脂代谢, 胰岛素通路

Abstract: 【Aim】 Starvation is one of the main stress signals for organisms in their developmental cycle. The purpose of this study is to understand how the silkworm (Bombyx mori) adjusts the metabolism conditions to survive after starvation and to explore the role of forkhead box transcription factor O gene (FoxO) in this process. 【Methods】 The 5th instar day-2 larvae of B. mori were subjected to chronical starvation for 72 h, the contents of triglyceride and glycogen in the fat body and the concentration of trehalose in the hemolymph were measured every 12 h, and the expression levels of BmFoxO, insulin receptor gene (InR) and protein kinase B gene (Akt) of insulin pathway and genes related to lipid metabolism were detected in the fat body by qPCR. A vector overexpressing BmFoxO was constructed and transfected into BmE cells, and the expression levels of genes related to glucose and lipid metabolism in BmE cells were detected by qPCR. 【Results】 The contents of glycogen and triglyceride in the fat body of the silkworm larvae continuously decreased within 72 h after starvation, and the concentration of trehalose in the hemolymph increased during 48 to 72 h after starvation. qPCR results revealed that the expression levels of genes of insulin pathway such as BmFoxO, InR and Akt and those linked to lipid metabolism enhanced remarkably during starvation stress, accelerating lipolysis. After overexpression of BmFoxO in BmE cells, the genes BmFoxO, InR and Akt showed a similar expression trend to that in B. mori larvae under starvation stress. 【Conclusion】 BmFoxO can regulate the glucose and lipid metabolism, and participate in the resistance to starvation in the silkworm. This study provides a basis for further studying the function of BmFoxO in the growth and metabolism in the silkworm.

Key words: Bombyx mori, BmFoxO, starvation stress, glucose and lipid metabolism, insulin pathway