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Lookup NU author(s): Dr Pavandeep Rai, Dr Satomi Miwa, Emeritus Professor Doug Turnbull
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
© 2021 The Author(s) 2021. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com. Context: Depot-specific expansion of orbital adipose tissue (OAT) in Graves orbitopathy (GO; an autoimmune condition producing proptosis, visual impairment and reduced quality of life) is associated with fatty acid (FA)-uptake-driven adipogenesis in preadipocytes/fibroblasts (PFs). Objective: This work sought a role for mitochondria in OAT adipogenesis in GO. Methods: Confluent PFs from healthy OAT (OAT-H), OAT from GO (OAT-GO) and white adipose tissue in culture medium compared with culture medium containing a mixed hormonal cocktail as adipogenic medium (ADM), or culture-medium containing FA-supplementation, oleate:palmitate:linoleate (45:30:25%) with/without different concentration of mitochondrial biosubstrate adenosine 5′-diphosphate/guanosine 5′-diphosphate (ADP/GDP), AICAR (adenosine analogue), or inhibitor oligomycin-A for 17 days. Main outcome measures included oil-red-O staining and foci count of differentiated adipocytes for in vitro adipogenesis, flow cytometry, relative quantitative polymerase chain reaction, MTS-assay/106 cells, total cellular-ATP detection kit, and Seahorse-XFe96-Analyzer for mitochondria and oxidative-phosphorylation (OXPHOS)/glycolysis-ATP production analysis. Results: During early adipogenesis before adipocyte formation (days 0, 4, and7), we observed OAT-specific cellular ATP production via mitochondrial OXPHOS in PFs both from OAT-H and OAT-GO, and substantially disrupted OXPHOS-ATP/glycolysis-ATP production in PFs from OAT-GO, for example, a 40% reduction in OXPHOS-ATP and trend-increased glycolysis-ATP production on days 4 and 7 compared with day 0, which contrasted with the stable levels in OAT-H. FA supplementation in culture-medium triggered adipogenesis in PFs both from OAT-H and OAT-GO, which was substantially enhanced by 1-mM GDP reaching 7% to 18% of ADM adipogenesis. The FA-uptake-driven adipogenesis was diminished by oligomycin-A but unaffected by treatment with ADP or AICAR. Furthermore, we observed a significant positive correlation between FA-uptake-driven adipogenesis by GDP and the ratios of OXPHOS-ATP/glycolysis-ATP through adipogenesis of PFs from OAT-GO. Conclusion: Our study confirmed that FA uptake can drive OAT adipogenesis and revealed a fundamental role for mitochondria-OXPHOS in GO development, which provides potential for therapeutic interventions.
Author(s): Zhang L, Rai P, Miwa S, Draman MS, Rees DA, Haridas AS, Morris DS, Tee AR, Ludgate M, Turnbull DM, Dayan CM
Publication type: Article
Publication status: Published
Journal: Endocrinology
Year: 2021
Volume: 162
Issue: 12
Print publication date: 01/12/2021
Online publication date: 02/09/2021
Acceptance date: 31/08/2021
Date deposited: 03/11/2023
ISSN (print): 0013-7227
ISSN (electronic): 1945-7170
Publisher: Endocrine Society
URL: https://doi.org/10.1210/endocr/bqab188
DOI: 10.1210/endocr/bqab188
PubMed id: 34473251
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