Induction of enhanced green fluorescent protein expression in response to lesions in the nervous system.
We have generated a mouse strain carrying a transgene driven by a strong and ubiquitous promoter (human cytomegalovirus hCMV/beta-actin) and containing an enhanced green fluorescent protein (eGFP) coding sequence upstream of the 3' untranslated region (3'UTR) of tissue-type plasminogen activator (t-PA) mRNA. The 3'UTR of t-PA mRNA is known to be involved in the reversible deadenylation and translational repression of transcripts in mouse oocytes. hCMV/beta-actin-eGFP-3'UTR t-PA transgenic mice express eGFP mRNA in all brain structures analyzed but lack eGFP fluorescence, with the exception of blood vessels, choroid plexus, and Purkinje cells. Taking advantage of these features, we tested whether certain pathological conditions, in particular injuries of the nervous system, might trigger eGFP fluorescence in traumatized cells or neurons. From this perspective, we analyzed eGFP mRNA expression and eGFP fluorescence in experimental models of nervous system lesions, such as motoneuron axotomy and cerebral stroke induced by middle cerebral artery occlusion. We found an increase in eGFP fluorescence in specific brain areas in cells suffering or reacting to these injuries. This increased fluorescence is correlated with an increased transcription of eGFP in lesioned cells, presumably enhanced by a release of the translational silencing mediated by the 3'UTR region of the t-PA mRNA. This transgenic mouse model may prove useful to study the development of neurodegenerative lesions.
Dubois-Dauphin
Michel
M
Department of Geriatrics, Biology of Aging Laboratory, Geneva University Hospital, 1225 Chêne-Bourg, Geneva, Switzerland. michel.dubois-dauphin@medecine.unige.ch
Eder-Colli
Lorenza
L
Vallet
Philippe
P
Stutz
André
A
Nef
Serge
S
Vassalli
Jean-Dominique
JD
D000818:Animals; D001921:Brain / Q000033:anatomy & histology / Q000378:metabolism; D020220:Facial Nerve Injuries / Q000378:metabolism; D007839:Functional Laterality; D005786:Gene Expression Regulation; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D049452:Green Fluorescent Proteins; D006801:Humans; D017403:In Situ Hybridization / Q000379:methods; D020244:Infarction, Middle Cerebral Artery / Q000150:complications / Q000378:metabolism; D008164:Luminescent Proteins / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic; D008856:Microscopy, Fluorescence; D006517:Murine hepatitis virus; D009420:Nervous System / Q000378:metabolism* / Q000473:pathology; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000502:physiology; D020521:Stroke / Q000209:etiology / Q000378:metabolism*; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000502:physiology*; D014404:Tubulin / Q000378:metabolism; D014452:Ubiquitins / Q000235:genetics; D020506:Untranslated Regions
D005904:Glial Fibrillary Acidic Protein; D008164:Luminescent Proteins; D012333:RNA, Messenger; C498585:TUBB3 protein, human; D014404:Tubulin; D014452:Ubiquitins; D020506:Untranslated Regions; D049452:Green Fluorescent Proteins; D010959:Tissue Plasminogen Activator