Scope: Brown adipose tissue (BAT) is the main regulator of thermogenesis by increasing energy expenditure through the uncoupling of oxidative metabolism from ATP synthesis. There is a growing body of evidence for BAT being the key responsible organ in combating obesity and its related disorders. Herein we propose the fungal protein ostreolysin (Oly), which has been previously shown to bind to cholesterol-enriched raft-like membrane domains (lipid rafts) of mammalian cells, as a suitable candidate for interaction with brown preadipocytes. The aim of the present study was therefore to characterize the mechanism by which a recombinant version of ostreolysin (rOly) induces brown adipocyte differentiation. Methods and results: Primary isolated brown preadipocytes or HIB-1B brown preadipocyte cells were treated with rOly and the effects on morphology, lipid accumulation, respiration rate, and associated gene and protein expression were measured. rOly upregulated mRNA and protein levels of factors related to brown adipocyte differentiation, induced lipid droplet formation, and increased cellular respiration rate due to expression of uncoupling protein 1. rOly also upregulated β-tubulin expression, and therefore microtubules might be involved in its mechanism of action. Conclusion: rOly promotes brown adipocyte differentiation, suggesting a new mechanism for rOly's contribution to the battle against obesity.
Bibliographical noteFunding Information:
B.S. and T.O. conceived and designed the experiments. T.O. performed most of the experiments and data analysis. M.S., A.D.P., and M.Y.N. modeled, analyzed, and visualized the 3D structure of the protein. A.F. and H.A. performed the chemical analyses of the protein. L.G. performed the proteomic analyses. I.P. provided technical assistance. K.S. performed some preliminary experiments. Y.H. conceived some of the experiments. B.S. contributed reagents, materials, and analytical tools. T.O. and B.S. wrote the manuscript and all of the authors made critical revisions. This research was partially funded by a grant number 390093, from Nofar, Chief Scientist, Israel. ERA-NET TargetECM network funding via Chief Science Ministry of Health, is gratefully acknowledged. A.D.P. is a recipient of the Lady Davis postdoctoral fellowship.
This research was partially funded by a grant number 390093, from Nofar, Chief Scientist, Israel. ERA-NET TargetECM network funding via Chief Science Ministry of Health, is gratefully acknowledged. A.D.P. is a recipient of the Lady Davis postdoctoral fellowship.
© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
- Brown adipocyte differentiation
- Brown adipose tissue
- Lipid droplet