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Investigating the effects of Orexin-A on thermogenesis in human deep neck brown adipose tissue

M F Pino1, A Divoux1, A V Simmonds2

  • 1Translational Research Institute for Metabolism and Diabetes, Florida Hospital, Orlando, FL, USA.

International Journal of Obesity (2005)
|July 5, 2017
PubMed
Abstract

Insights

Orexin-A (OX-A) does not increase thermogenesis in human brown adipose tissue, contrary to rodent studies. This highlights challenges in translating preclinical findings to human therapeutic development.

Area of Science:

  • Metabolism and Endocrinology
  • Cell Biology
  • Drug Discovery

Background:

  • 85% of early clinical trials fail due to molecular mechanisms, necessitating validated human models.
  • Obesity is linked to lower circulating Orexin-A (OX-A) levels in humans.
  • Rodent studies show OX-A enhances thermogenesis in brown adipose tissue (AT), but human relevance is unknown.

Purpose of the Study:

  • To establish and utilize a human cell-based model system to investigate the effects of OX-A on thermogenesis.
  • To determine if OX-A-mediated thermogenesis observed in rodents is conserved in human brown adipocytes.

Main Methods:

  • Developed a cell-based model using human brown and white adipocytes.
  • Administered OX-A alone and with adrenergic stimuli to the human adipocyte models.
  • Assessed thermogenesis and related transcriptional changes.

Main Results:

  • Orexin-A treatment did not enhance thermogenesis in human brown adipocytes.
  • No increase in thermogenesis or its transcriptional program was observed, even with adrenergic co-stimulation.
  • Results contradict previous findings in rodent models.

Conclusions:

  • Preclinical findings on Orexin-A's thermogenic effects in rodents do not translate to human brown adipocytes.
  • Validated human in vitro models are crucial for overcoming challenges in therapeutic development.
  • Further research is needed to understand OX-A's role in human metabolism and identify effective therapeutic targets.

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