bcl-x is expressed in embryonic and postnatal neural tissues and functions to prevent neuronal cell death.
Previous studies have implicated the bcl-2 protooncogene as a potential regulator of neuronal survival. However, mice lacking functional bcl-2 exhibited normal development and maintenance of the central nervous system (CNS). Since bcl-2 appears dispensable for neuronal survival, we have examined the expression and function of bcl-x, another member of the bcl-2 family of death regulatory genes. Bcl-2 is expressed in neuronal tissues during embryonic development but is down-regulated in the adult CNS. In contrast, Bcl-xL expression is retained in neurons of the adult CNS. Two different forms of bcl-x mRNA and their corresponding products, Bcl-xL and Bcl-x beta, were expressed in embryonic and adult neurons of the CNS. Microinjection of bcl-xL and bcl-x beta cDNAs into primary sympathetic neurons inhibited their death induced by nerve growth factor withdrawal. Thus, Bcl-x proteins appear to play an important role in the regulation of neuronal survival in the adult CNS.
González-García
M
M
Department of Pathology and Anatomy, University of Michigan Medical School, Ann Arbor 48109, USA.
García
I
I
Ding
L
L
O'Shea
S
S
Boise
L H
LH
Thompson
C B
CB
Núñez
G
G
D000375:Aging / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D001921:Brain / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*; D016923:Cell Death / Q000502:physiology*; D002478:Cells, Cultured; D018076:DNA, Complementary; D005314:Embryonic and Fetal Development; D017403:In Situ Hybridization; D008099:Liver / Q000378:metabolism; D008845:Microinjections; D009474:Neurons / Q000166:cytology* / Q000378:metabolism*; D009928:Organ Specificity; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis*; D019253:Proto-Oncogene Proteins c-bcl-2; D051381:Rats; D013116:Spinal Cord / Q000254:growth & development / Q000378:metabolism*; D017783:Superior Cervical Ganglion / Q000166:cytology / Q000502:physiology; D051020:bcl-X Protein
C494813:Bcl2l1 protein, rat; D018076:DNA, Complementary; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051020:bcl-X Protein