Diffuse Optical Spectroscopy and Imaging to Detect and Quantify Adipose Tissue Browning

Sci Rep. 2017 Feb 1:7:41357. doi: 10.1038/srep41357.

Abstract

Adipose (fat) tissue is a complex metabolic organ that is highly active and essential. In contrast to white adipose tissue (WAT), brown adipose tissue (BAT) is deemed metabolically beneficial because of its ability to burn calories through heat production. The conversion of WAT-resident adipocytes to "beige" or "brown-like" adipocytes has recently attracted attention. However, it typically takes a few days to analyze and confirm this browning of WAT through conventional molecular, biochemical, or histological methods. Moreover, accurate quantification of the overall browning process is not possible by any of these methods. In this context, we report the novel application of diffuse reflectance spectroscopy (DRS) and multispectral imaging (MSI) to detect and quantify the browning process in mice. We successfully demonstrated the time-dependent increase in browning of WAT, following its induction through β-adrenergic agonist injections. The results from these optical techniques were confirmed with those of standard molecular and biochemical assays, which measure gene and protein expression levels of UCP1 and PGC-1α, as well as with histological examinations. We envision that the reported optical methods can be developed into a fast, real time, cost effective and easy to implement imaging approach for quantification of the browning process in adipose tissue.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipocytes / drug effects
  • Adipocytes / metabolism
  • Adipose Tissue, Brown / drug effects
  • Adipose Tissue, Brown / metabolism*
  • Animals
  • Biomarkers / metabolism
  • Dioxoles / pharmacology
  • Gene Expression Regulation / drug effects
  • Imaging, Three-Dimensional*
  • Mice, Inbred BALB C
  • Mice, Nude
  • Optical Fibers
  • Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha / metabolism
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Spectrum Analysis / methods*
  • Uncoupling Protein 1 / metabolism

Substances

  • Biomarkers
  • Dioxoles
  • Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha
  • Ppargc1a protein, mouse
  • RNA, Messenger
  • Uncoupling Protein 1
  • disodium (R,R)-5-(2-((2-(3-chlorophenyl)-2-hydroxyethyl)-amino)propyl)-1,3-benzodioxole-2,3-dicarboxylate