Molecular comparison of GLT1+ and ALDH1L1+ astrocytes in vivo in astroglial reporter mice.
Astrocyte heterogeneity remains largely unknown in the CNS due to lack of specific astroglial markers. In this study, molecular identity of in vivo astrocytes was characterized in BAC ALDH1L1 and BAC GLT1 eGFP promoter reporter transgenic mice. ALDH1L1 promoter is selectively activated in adult cortical and spinal cord astrocytes, indicated by the overlap of eGFP expression with ALDH1L1 and GFAP, but not with NeuN, APC, Olig2, IbaI, PDGFRα immunoreactivity in BAC ALDH1L1 eGFP reporter mice. Interestingly, ALDH1L1 expression levels (protein, mRNA, and promoter activity) in spinal cord were selectively decreased during postnatal maturation. In contrast, its expression was up-regulated in reactive astrocytes in both acute neural injury and chronic neurodegenerative (G93A mutant SOD1) conditions, similar to GFAP, but opposite of GLT1. ALDH1L1(+) and GLT1(+) cells isolated through fluorescence activated cell sorting (FACS) from BAC ALDH1L1 and BAC GLT1 eGFP mice share a highly similar gene expression profile, suggesting ALDH1L1 and GLT1 are co-expressed in the same population of astrocytes. This observation was further supported by overlap of the eGFP driven by the ALDH1L1 genomic promoter and the tdTomato driven by a 8.3kb EAAT2 promoter fragment in astrocytes of BAC ALDH1L1 eGFP X EAAT2-tdTomato mice. These studies support ALDH1L1 as a general CNS astroglial marker and investigated astrocyte heterogeneity in the CNS by comparing the molecular identity of the ALDH1L1(+) and GLT1(+) astrocytes from astroglial reporter mice. These astroglial reporter mice provide useful in vivo tools for the molecular analysis of astrocytes in physiological and pathological conditions.
Department of Neurology, Johns Hopkins University, Baltimore, Maryland 21205, USA.
Yongjie
Y
Yang
Svetlana
S
Vidensky
Lin
L
Jin
Chunfa
C
Jie
Ileana
I
Lorenzini
Miriam
M
Frankl
Jeffrey D
JD
Rothstein
D000444:Aldehyde Dehydrogenase / Q000235:genetics*; D000080924:Aldehyde Dehydrogenase 1 Family; D000818:Animals; D001253:Astrocytes / Q000378:metabolism*; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology; D022202:Chromosomes, Artificial, Bacterial / Q000235:genetics; D027342:Excitatory Amino Acid Transporter 2 / Q000235:genetics*; D005434:Flow Cytometry / Q000379:methods; D020869:Gene Expression Profiling / Q000379:methods; D005786:Gene Expression Regulation / Q000235:genetics*; D005904:Glial Fibrillary Acidic Protein / Q000235:genetics / Q000378:metabolism; D050491:Glutamate Plasma Membrane Transport Proteins / Q000235:genetics; D049452:Green Fluorescent Proteins / Q000235:genetics; D006801:Humans; D007527:Isoenzymes / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009474:Neurons / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D037121:Plant Lectins / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D050697:Retinal Dehydrogenase; D013116:Spinal Cord / Q000166:cytology; D013482:Superoxide Dismutase / Q000235:genetics
D027342:Excitatory Amino Acid Transporter 2; D005904:Glial Fibrillary Acidic Protein; D050491:Glutamate Plasma Membrane Transport Proteins; D007527:Isoenzymes; D037121:Plant Lectins; C493397:SLC1A2 protein, human; C485184:enhanced green fluorescent protein; C034981:tomato lectin; D049452:Green Fluorescent Proteins; C109415:SOD1 G93A protein; D013482:Superoxide Dismutase; D000080924:Aldehyde Dehydrogenase 1 Family; D000444:Aldehyde Dehydrogenase; C510223:ALDH1A1 protein, human; C515028:ALDH1A1 protein, mouse; D050697:Retinal Dehydrogenase