Neuron-specific conditional expression of a mitochondrially targeted fluorescent protein in mice.
Mitochondrial dysfunction contributes to the pathophysiology of both acute and chronic neurodegenerative disorders. Quantification of mitochondrial bioenergetic properties generally requires the use of isolated brain mitochondria. However, the involvement of neuronal mitochondrial dysfunction in these disorders is limited by the lack of markers, and therefore isolation procedures, that distinguish neuronal compared with astrocyte mitochondria. To address this and other issues concerning neuronal mitochondria in the CNS, transgenic mice were generated that express a fluorescent protein targeted specifically to neurons. A neuron-specific promoter, CaMKIIalpha (calcium/calmodulin-dependent kinase IIalpha) driven tTA (tetracycline transactivator) mice were crossed with TRE (tetracycline responsive element) driven mitochondrial targeted enhanced yellow fluorescent protein (eYFP) mice. Expression of eYFP in the bigenic mouse brain was observed only in neuronal mitochondria of striatum, forebrain, and hippocampus and was enhanced by the removal of the tetracycline analog doxycycline (Dox) in the diet. The respiratory control ratio of synaptic and nonsynaptic mitochondria isolated from eYFP-expressing mice was the same as control mice, suggesting that neuronal mitochondria expressing eYFP maintain normal bioenergetic functions. More importantly, the development of Dox-inducible, neuron targeted mito/eYFP transgenic mice offer a unique in vivo model for delineating the participation of neuronal mitochondria in neuronal survival and death.
Chandrasekaran
Krish
K
Department of Anesthesiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA. kchan004@umaryland.edu
Hazelton
Julie L
JL
Wang
Yu
Y
Fiskum
Gary
G
Kristian
Tibor
T
D000818:Animals; D001426:Bacterial Proteins / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics*; D001923:Brain Chemistry / Q000235:genetics; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000096:biosynthesis / Q000235:genetics; D004195:Disease Models, Animal; D004734:Energy Metabolism / Q000235:genetics; D005456:Fluorescent Dyes; D018507:Gene Expression Regulation, Developmental; D018390:Gene Targeting / Q000379:methods*; D008164:Luminescent Proteins / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008928:Mitochondria / Q000737:chemistry / Q000378:metabolism*; D019636:Neurodegenerative Diseases / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D009474:Neurons / Q000737:chemistry / Q000166:cytology / Q000378:metabolism*; D020521:Stroke / Q000201:enzymology / Q000235:genetics / Q000473:pathology
D001426:Bacterial Proteins; D005456:Fluorescent Dyes; D008164:Luminescent Proteins; C054562:yellow fluorescent protein, Bacteria; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases; C517671:Camk2a protein, mouse