1
|
Thomas AS, Sassi M, Angelini R, Morgan AH, Davies JS. Acylation, a Conductor of Ghrelin Function in Brain Health and Disease. Front Physiol 2022; 13:831641. [PMID: 35845996 PMCID: PMC9280358 DOI: 10.3389/fphys.2022.831641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 03/31/2022] [Indexed: 11/22/2022] Open
Abstract
Acyl-ghrelin (AG) is an orexigenic hormone that has a unique octanoyl modification on its third serine residue. It is often referred to as the “hunger hormone” due to its involvement in stimulating food intake and regulating energy homeostasis. The discovery of the enzyme ghrelin-O-acyltransferase (GOAT), which catalyses ghrelin acylation, provided further insights into the relevance of this lipidation process for the activation of the growth hormone secretagogue receptor (GHS-R) by acyl-ghrelin. Although acyl-ghrelin is predominantly linked with octanoic acid, a range of saturated fatty acids can also bind to ghrelin possibly leading to specific functions. Sources of ghrelin acylation include beta-oxidation of longer chain fatty acids, with contributions from fatty acid synthesis, the diet, and the microbiome. In addition, both acyl-ghrelin and unacyl-ghrelin (UAG) have feedback effects on lipid metabolism which in turn modulate their levels. Recently we showed that whilst acyl-ghrelin promotes adult hippocampal neurogenesis and enhances memory function, UAG inhibits these processes. As a result, we postulated that the circulating acyl-ghrelin:unacyl-ghrelin (AG:UAG) ratio might be an important regulator of neurogenesis and cognition. In this review, we discuss emerging evidence behind the relevance of ghrelin acylation in the context of brain physiology and pathology, as well as the current challenges of identifying the provenance of the acyl moiety.
Collapse
|
2
|
Nakajima K, Maeda N, Oiso S, Kariyazono H. Decreased Plasma Octanoylated Ghrelin Levels in Mice by Oleanolic Acid. J Oleo Sci 2018; 68:103-109. [PMID: 30542007 DOI: 10.5650/jos.ess18148] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Ghrelin is a stomach-derived peptide hormone with an appetite-stimulating effect. Octanoylation on the serine-3 residue of ghrelin by ghrelin O-acyl transferase (GOAT) is essential for its orexigenic effect. Mature octanoylated ghrelin is generated by the C-terminal cleavage of octanoylated proghrelin via prohormone convertases (furin, PC1/3, or PC2). We previously established an AGS-GHRL8 cell line that produces octanoylated ghrelin in the presence of octanoic acid, and found that oleanolic acid suppresses octanoylated ghrelin production in AGS-GHRL8 cells. Here, we investigated the effects of oleanolic acid in C57BL/6J mice fed a standard, high-fat, or high-glucose diet. Oral administration of oleanolic acid for seven days (20 or 40 mg/kg) reduced plasma octanoylated ghrelin levels and body weight gain in the standard diet-fed mice but not in other two diet-fed mice. There were no significant differences in ghrelin, GOAT, furin, PC1/3, and PC2 gene expression levels between the vehicle- and oleanolic acid-treated mice fed a standard diet. Octanoyl-CoA is a substrate for ghrelin octanoylation by GOAT. We found that oleanolic acid did not affect octanoyl-CoA production in vitro. Hence, the inhibitory effect of oleanolic acid on octanoylated ghrelin production may not be related to the decrease in octanoyl-CoA. The results of this study may provide valuable knowledge for the development of anti-obesity agents with an inhibitory effect on octanoylated ghrelin production.
Collapse
Affiliation(s)
- Kensuke Nakajima
- Department of Pharmacy, Faculty of Pharmaceutical Sciences, Nagasaki International University
| | - Narumi Maeda
- Department of Pharmacy, Faculty of Pharmaceutical Sciences, Nagasaki International University
| | - Shigeru Oiso
- Department of Pharmacy, Faculty of Pharmaceutical Sciences, Nagasaki International University.,Graduate School of Pharmaceutical Sciences, Nagasaki International University
| | - Hiroko Kariyazono
- Department of Pharmacy, Faculty of Pharmaceutical Sciences, Nagasaki International University.,Graduate School of Pharmaceutical Sciences, Nagasaki International University
| |
Collapse
|
3
|
Nakajima K, Oiso S, Kariyazono H. Inhibitory Effect of (-)-Epigallocatechin-3-O-gallate on Octanoylated Ghrelin Levels in Vitro and in Vivo. Biol Pharm Bull 2018; 41:524-529. [PMID: 29607924 DOI: 10.1248/bpb.b17-00805] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ghrelin is an orexigenic peptide hormone produced in the stomach. The major active form is octanoylated ghrelin, which is modified with an n-octanoic acid at the serine-3 residue. Inhibition of octanoylated ghrelin production is useful for the prevention and improvement of obesity. We previously developed a cell-based assay system employing a ghrelin-expressing cell line, AGS-GHRL8, and found various compounds that decreased octanoylated ghrelin levels using this system. (-)-Epigallocatechin-3-O-gallate (EGCG) is a bioactive catechin in green tea and reportedly has an anti-obesity effect; however, it remains unclear whether EGCG inhibits octanoylated ghrelin production. Therefore, in this study, we investigated the effect of EGCG on octanoylated ghrelin levels in AGS-GHRL8 cells and C57BL/6J mice. EGCG significantly reduced the octanoylated ghrelin level in AGS-GHRL8 cells. In mice, three days of treatment with TEAVIGO®, which contains 97.69% EGCG, lowered the plasma octanoylated ghrelin level by 40% from that in control mice. In addition, TEAVIGO® reduced the mRNA expression of ghrelin and prohormone convertase 1/3, an enzyme responsible for the processing of proghrelin to mature ghrelin, in the mouse stomach, suggesting that the reduced expression of these genes may contribute to the inhibition of octanoylated ghrelin production. These results suggest a decrease in the octanoylated ghrelin level to be involved in the anti-obesity effect of EGCG, which thus has potential for the development of anti-obesity agents with ghrelin-lowering effect.
Collapse
Affiliation(s)
- Kensuke Nakajima
- Graduate School of Pharmaceutical Sciences, Nagasaki International University
| | - Shigeru Oiso
- Graduate School of Pharmaceutical Sciences, Nagasaki International University
| | - Hiroko Kariyazono
- Graduate School of Pharmaceutical Sciences, Nagasaki International University
| |
Collapse
|
4
|
Tung NH, Nakajima K, Uto T, Hai NT, Long DD, Ohta T, Oiso S, Kariyazono H, Shoyama Y. Bioactive Triterpenes from the Root of Salvia miltiorrhiza Bunge. Phytother Res 2017; 31:1457-1460. [PMID: 28766764 DOI: 10.1002/ptr.5877] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 07/03/2017] [Accepted: 07/03/2017] [Indexed: 11/10/2022]
Abstract
Danshen (Salvia miltiorrhiza) is a well-known medicinal herb in the oriental medicine. The current study on bioactive triterpenoid in the root of S. miltiorrhiza led to the isolation of a new highly hydroxylated ursane-type triterpene, urs-12-ene-2α,3β,7β,16α-tetraol (1) and five known ones including 2β-hydroxypomolic acid (2), maslinic acid (3), asiatic acid (4), ursolic acid (5), and oleanolic acid (6). Their structures were elucidated on the basis of extensive spectroscopic analyses and comparison with literature data. The antiproliferative testing against HL-60 cells revealed that the new compound 1 and ursolic acid (5) showed weak and moderate activities with IC50 values of 42.2 and 11.7 μM. In addition, compounds 1-3 showed inhibitory effect on ghrelin activity. Copyright © 2017 John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Nguyen Huu Tung
- Faculty of Pharmaceutical Sciences, Nagasaki International University, 2825-7 Huis Ten Bosch, Sasebo, Nagasaki, 859-3298, Japan
- School of Medicine and Pharmacy, Vietnam National University, Hanoi (VNU), 144 Xuan Thuy Street, Cau Giay, Hanoi, Vietnam
| | - Kensuke Nakajima
- Faculty of Pharmaceutical Sciences, Nagasaki International University, 2825-7 Huis Ten Bosch, Sasebo, Nagasaki, 859-3298, Japan
| | - Takuhiro Uto
- Faculty of Pharmaceutical Sciences, Nagasaki International University, 2825-7 Huis Ten Bosch, Sasebo, Nagasaki, 859-3298, Japan
| | - Nguyen Thanh Hai
- School of Medicine and Pharmacy, Vietnam National University, Hanoi (VNU), 144 Xuan Thuy Street, Cau Giay, Hanoi, Vietnam
| | - Dinh Doan Long
- School of Medicine and Pharmacy, Vietnam National University, Hanoi (VNU), 144 Xuan Thuy Street, Cau Giay, Hanoi, Vietnam
| | - Tomoe Ohta
- Faculty of Pharmaceutical Sciences, Nagasaki International University, 2825-7 Huis Ten Bosch, Sasebo, Nagasaki, 859-3298, Japan
| | - Shigeru Oiso
- Faculty of Pharmaceutical Sciences, Nagasaki International University, 2825-7 Huis Ten Bosch, Sasebo, Nagasaki, 859-3298, Japan
| | - Hiroko Kariyazono
- Faculty of Pharmaceutical Sciences, Nagasaki International University, 2825-7 Huis Ten Bosch, Sasebo, Nagasaki, 859-3298, Japan
| | - Yukihiro Shoyama
- Faculty of Pharmaceutical Sciences, Nagasaki International University, 2825-7 Huis Ten Bosch, Sasebo, Nagasaki, 859-3298, Japan
| |
Collapse
|
5
|
NAKAJIMA K, OISO S, UTO T, MORINAGA O, SHOYAMA Y, KARIYAZONO H. Triterpenes suppress octanoylated ghrelin production in ghrelin-expressing human gastric carcinoma cells . Biomed Res 2016; 37:343-349. [DOI: 10.2220/biomedres.37.343] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
| | - Shigeru OISO
- Graduate School of Pharmaceutical Sciences, Nagasaki University
| | - Takuhiro UTO
- Graduate School of Pharmaceutical Sciences, Nagasaki University
| | - Osamu MORINAGA
- Department of Natural Medicines, Daiichi University of Pharmacy
| | | | | |
Collapse
|
6
|
Oiso S, Nobe M, Iwasaki S, Nii W, Goto N, Seki Y, Nakajima K, Nakamura K, Kariyazono H. Inhibitory Effect of Oleic Acid on Octanoylated Ghrelin Production. J Oleo Sci 2015; 64:1185-92. [DOI: 10.5650/jos.ess15137] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Shigeru Oiso
- Graduate School of Pharmaceutical Sciences, Nagasaki International University
- Department of Pharmacy, Faculty of Pharmaceutical Sciences, Nagasaki International University
| | - Miyuki Nobe
- Department of Pharmacy, Faculty of Pharmaceutical Sciences, Nagasaki International University
| | - Syuhei Iwasaki
- Department of Pharmacy, Faculty of Pharmaceutical Sciences, Nagasaki International University
| | - Wakana Nii
- Department of Pharmacy, Faculty of Pharmaceutical Sciences, Nagasaki International University
| | - Natsumi Goto
- Department of Pharmacy, Faculty of Pharmaceutical Sciences, Nagasaki International University
| | - Yukari Seki
- Department of Pharmacy, Faculty of Pharmaceutical Sciences, Nagasaki International University
| | - Kensuke Nakajima
- Graduate School of Pharmaceutical Sciences, Nagasaki International University
- Department of Pharmacy, Faculty of Pharmaceutical Sciences, Nagasaki International University
| | - Kazuo Nakamura
- Department of Biopharmaceutics, Nihon Pharmaceutical University
| | - Hiroko Kariyazono
- Graduate School of Pharmaceutical Sciences, Nagasaki International University
- Department of Pharmacy, Faculty of Pharmaceutical Sciences, Nagasaki International University
| |
Collapse
|