Translocator protein (Tspo) gene promoter-driven green fluorescent protein synthesis in transgenic mice: an in vivo model to study Tspo transcription

Cell Tissue Res. 2012 Nov;350(2):261-75. doi: 10.1007/s00441-012-1478-5. Epub 2012 Aug 7.

Abstract

Translocator protein (TSPO), previously known as the peripheral-type benzodiazepine receptor, is a ubiquitous drug- and cholesterol-binding protein primarily found in the outer mitochondrial membrane as part of a mitochondrial cholesterol transport complex. TSPO is present at higher levels in steroid-synthesizing and rapidly proliferating tissues and its biological role has been mainly linked to mitochondrial function, steroidogenesis and cell proliferation/apoptosis. Aberrant TSPO levels have been linked to multiple diseases, including cancer, endocrine disorders, brain injury, neurodegeneration, ischemia-reperfusion injury and inflammatory diseases. Investigation of the functions of this protein in vitro and in vivo have been mainly carried out using high-affinity drug ligands, such as isoquinoline carboxamides and benzodiazepines and more recently, gene silencing methods. To establish a model to study the regulation of Tspo transcription in vivo, we generated a transgenic mouse model expressing green fluorescent protein (GFP) from Aequorea coerulescens under control of the Tspo promoter region (Tspo-AcGFP). The expression profiles of Tspo-AcGFP, endogenous TSPO and Tspo mRNA were found to be well-correlated. Tspo-AcGFP synthesis in the transgenic mice was seen in almost every tissue examined and as with TSPO in wild-type mice, Tspo-AcGFP was highly expressed in steroidogenic cells of the endocrine and reproductive systems, epithelial cells of the digestive system, skeletal muscle and other organs. In summary, this transgenic Tspo-AcGFP mouse model recapitulates endogenous Tspo expression patterns and could be a useful, tractable tool for monitoring the transcriptional regulation and function of Tspo in live animal experiments.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Growth Processes / physiology
  • Disease Models, Animal
  • Female
  • Green Fluorescent Proteins / biosynthesis*
  • Green Fluorescent Proteins / genetics*
  • Green Fluorescent Proteins / metabolism
  • Immunohistochemistry
  • Male
  • Mice
  • Mice, Transgenic
  • Promoter Regions, Genetic
  • RNA, Messenger / biosynthesis
  • RNA, Messenger / genetics
  • Receptors, GABA / biosynthesis*
  • Receptors, GABA / genetics*
  • Receptors, GABA / metabolism
  • Transcription, Genetic
  • Transcriptome

Substances

  • Bzrp protein, mouse
  • RNA, Messenger
  • Receptors, GABA
  • Green Fluorescent Proteins