Developmental expression of Bcl-2 protein in human cortex.
Apoptosis is essential for normal human neurodevelopment and is increasingly recognized for its role in various neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. Bcl-2 is a 26 kDa membrane-associated protein known to protect neurons against apoptosis. Interestingly, Bcl-2 protein levels are altered in certain neurodegenerative disorders that reveal increased apoptosis. However, little is known about the normal expression of Bcl-2 protein in human brain. Bcl-2 protein levels were determined by ELISA and semiquantitative Western Blotting in the frontal cortex of 20 human post-mortem brains, separated into three groups: six infants (age: 0.83+/-1.0 years, mean+/-S.D.), five adolescents (age: 17.4+/-1.7 years), and nine adults (age: 41.0+/-9.6 years). All subjects died of non-CNS related illness and had no history of psychiatric illness. Bcl-2 increased significantly across the age groups in the ELISA (p=0.0058) and the Western Blot (p=0.002) experiments. The ELISA demonstrated significant differences in Bcl-2 levels between infant and adolescent cortex (p<0.05), and between infant and adult cortex (p<0.01) using a post-hoc Tukey's multiple comparison test. The Western blots demonstrated a similar significant increase in Bcl-2 between infant and adult cortex (p<0. 01). A secondary analysis showed significant correlation between individual ages and Bcl-2 levels (r(2)=0.4933, p=0.0006). This study demonstrates that Bcl-2 protein expression in human cortex is developmentally regulated and supports the hypothesis that Bcl-2 is involved in normal aging.
Jarskog
L F
LF
Department of Psychiatry, C.B. #7160, University of North Carolina School of Medicine, Chapel Hill, NC 27599-7160, USA. fjarskog@css.unc.edu
Gilmore
J H
JH
D000293:Adolescent; D000328:Adult; D000375:Aging / Q000502:physiology; D000818:Animals; D017209:Apoptosis / Q000502:physiology; D015153:Blotting, Western; D001923:Brain Chemistry / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005625:Frontal Lobe / Q000737:chemistry / Q000254:growth & development* / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D009410:Nerve Degeneration / Q000503:physiopathology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis / Q000235:genetics*; D051381:Rats; D017207:Rats, Sprague-Dawley
D019253:Proto-Oncogene Proteins c-bcl-2