Nishi Yoshihiro, Mifune Hiroharu, Kojima Masayasu
Department of Physiology, Kurume University School of Medicine, Asahi-machi, Kurume, Japan.
Methods Enzymol. 2012;514:303-15. doi: 10.1016/B978-0-12-381272-8.00019-2.
We found in a primary study that ingestion of medium-chain fatty acids (MCFAs) or medium-chain triacylglycerols (MCTs) increased the stomach contents of acyl ghrelin, and we further showed that the carbon-chain length of the acyl groups that modified the nascent ghrelin peptides corresponded to that of the ingested MCFAs or MCTs. These findings clearly demonstrated that the ingested MCFAs are directly used for the acyl-modification of ghrelin. Before the discovery of ghrelin-O-acyltransferase (GOAT), our in vivo study suggested that the putative GOAT preferred MCTs (composed of C6:0 to C10:0 FFAs) to either short- or long-chain triglycerides. In another study, we suggested that MCFAs or MCTs might represent a potential therapeutic modality for the clinical manipulation of energy metabolism through the modulation of ghrelin activity. After the discovery of GOAT, many studies have been done on the acylation of ghrelin using MCFAs, MCTs, or their derivatives; however, results and interpretations have been inconsistent, largely due to the differences in experimental conditions. This chapter describes detailed methods for the analysis of ghrelin acylation in vivo to facilitate future research in this field.
我们在一项初步研究中发现，摄入中链脂肪酸（MCFAs）或中链甘油三酯（MCTs）会增加胃内酰基胃饥饿素的含量，并且我们进一步表明，修饰新生胃饥饿素肽的酰基的碳链长度与摄入的MCFAs或MCTs的碳链长度相对应。这些发现清楚地表明，摄入的MCFAs直接用于胃饥饿素的酰基修饰。在发现胃饥饿素O-酰基转移酶（GOAT）之前，我们的体内研究表明，假定的GOAT对MCTs（由C6:0至C10:0脂肪酸组成）的偏好高于短链或长链甘油三酯。在另一项研究中，我们提出MCFAs或MCTs可能代表一种潜在的治疗方式，可通过调节胃饥饿素活性来临床调控能量代谢。在发现GOAT之后，已经使用MCFAs、MCTs或其衍生物对胃饥饿素的酰化进行了许多研究；然而，结果和解释并不一致，这在很大程度上是由于实验条件的差异。本章描述了体内胃饥饿素酰化分析的详细方法，以促进该领域未来的研究。
