Horm Metab Res 2020; 52(10): 747-754
DOI: 10.1055/a-1207-1212
Endocrine Research

Unacylated Ghrelin Regulates Glucose-Sensitive Neurons Activity and Glycolipid Metabolism via Orexin-A Neurons in the Lateral Hypothalamic Area

Manqing Su
1   Department of Pharmacy, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, China
,
Meixing Yan
2   Qingdao Women and Children’s Hospital, Qingdao, China
,
Jiatong Yao
1   Department of Pharmacy, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, China
,
Yanpeng Fang
1   Department of Pharmacy, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, China
,
Hong Jin
1   Department of Pharmacy, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, China
,
Yanling Gong
1   Department of Pharmacy, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, China
› Author Affiliations
Funding Information Shandong Eco-Chemical Cooperative Innovation Center, Shandong Provincial Key Laboratory of Multiphase Fluid Reaction and Separation Engineering, and Shandong Provincial R & D Program Key Project. No. 2018GSF119005.

Abstract

The objective of the study was to investigate the regulatory actions of unacylated ghrelin (UAG) on glucose-sensitive (GS) neurons and glycolipid metabolism in the lateral hypothalamus area (LHA) and its involvement with orexin-A-immunopositive neurons. The effects of UAG administered into the LHA on GS neurons discharges and glycolipid metabolism were detected by single neuron discharge recording, biochemical index analysis and quantitative real-time PCR; the level of c-fos protein in orexin-A-immunopositive neurons was observed using immunofluorescence staining. UAG microinjected into the LHA activated glucose-inhibited neurons, which were partially blocked by pre-administration of anti-orexin-A antibody in the LHA. Furthermore, UAG microinjected into the LHA significantly reduced serum triglycerides (TG), total cholesterol, low-density lipoprotein cholesterol, blood glucose, insulin and hepatic TG levels, while elevated serum high-density lipoprotein cholesterol levels. UAG elevated the mRNA expression of carnitine palmitoyltransferase-1 and reduced the mRNA expression of acetyl-CoA carboxylase-1 in the liver. The above-mentioned effects of UAG were partially blocked by pre-administration of anti-orexin-A antibody. The expressions of orexin-A and c-fos were observed in the LHA. After UAG injection into the LHA, some neurons showed double labeling, and the percentage of double-labeled orexin-A/c-fos neurons in orexin-A-immunopositive neurons increased significantly. UAG in the LHA regulates glycolipid metabolism by activating orexin-A-immunopositive neurons in the LHA.



Publication History

Received: 20 December 2019

Accepted after revision: 17 June 2020

Article published online:
27 July 2020

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