Pedtidomics of Cpefat/fat mouse hypothalamus -: Effect of food deprivation and exercise on peptide levels
Pedtidomics of Cpefat/fat mouse hypothalamus -: Effect of food deprivation and exercise on peptide levels
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DOI：
10.1074/jbc.m411178200
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发表时间：
2005-02-11
影响因子：
4.8
通讯作者：
Fricker, LD
中科院分区：
文献类型：
--
作者：
Che, FY;Yuan, Q;Fricker, LD
羧基肽酶E是多种神经内分泌肽生物合成的主要酶。此前，我们开发了一种从由于自然发生的点突变而缺乏羧肽酶E活性的小鼠(脂肪/脂肪小鼠)中分离神经肽加工中间体的技术。在这项研究中，我们使用稳定的同位素标记和质谱学的差异标记程序来量化CPE(FAT/FAT)小鼠在两种不同模式下下丘脑多肽的相对变化，每种模式都会导致体重减少10%。一种模式是在正常的久坐状态下禁食2天(即标准的鼠笼)；另一种模式是让小鼠在4周内自由使用运动轮并免费进食。在两项研究中都检测到大约50个多肽，在两个研究中至少有一项检测到超过80个多肽。禁食使28种多肽增加了50%，其中一些增加了2-3倍。相比之下，在运动轮组中，只有三种多肽增加了50%，许多多肽在运动后略有下降15%-30%。在这两项研究中检测到的多肽中，大约有一半是通过串联质谱仪进行鉴定的。被发现在缺乏食物但没有运动的情况下升高的多肽包括一些前脑啡肽原片段、促甲状腺激素释放激素原、分泌颗粒素II、嗜铬颗粒素B和前SAAS。综上所述，这些多肽在两种范式中的不同调节表明，这种调节不是由于较低的体重，而是由于两种范式实现较低体重的方式。
Carboxypeptidase E is a major enzyme in the biosynthesis of numerous neuroendocrine peptides. Previously, we developed a technique for the isolation of neuropeptide-processing intermediates from mice that lack carboxypeptidase E activity Cpe(fat/fat) mice) due to a naturally occurring point mutation. In the present study, we used a differential labeling procedure with stable isotopic tags and mass spectrometry to quantitate the relative changes in a number of hypothalamic peptides in Cpe(fat/fat) mice in two different paradigms that each cause an similar to10% decrease in body mass. One paradigm involved a 2-day fast under normal sedentary conditions (i.e. standard mouse cages); the other involved giving mice access to an exercise wheel for 4 weeks with free access to food. Approximately 50 peptides were detected in both studies, and over 80 peptides were detected in at least one of the two studies. Twenty-eight peptides were increased >50% by food deprivation, and some of these were increased by 2- to 3-fold. In contrast, only three peptides were increased >50% in the group with exercise wheels, and many peptides showed a slight 15-30% decrease upon exercise. Approximately one-half of the peptides detected in both studies were identified by tandem mass spectrometry. Peptides found to be elevated by food deprivation but not exercise included a number of fragments of proenkephalin, prothyrotropin-releasing hormone, secretogranin II, chromogranin B, and pro-SAAS. Taken together, the differential regulation of these peptides in the two paradigms suggests that the regulation is not due to the lower body weight but to the manner in which the paradigms achieved this lower body weight.