Brain-derived neurotrophic factor gene and protein expression in pediatric and adult depressed subjects.
BACKGROUND
Brain-derived neurotrophic factor (BDNF) is a member of a neurotrophin family and is involved in many physiological functions, including cell proliferation, migration, and differentiation, and neuron survival in the human nervous system. Abnormalities of BDNF have been implicated in the pathophysiology of depression based on observations that antidepressant drugs cause increases in the levels of BDNF in rat brains and its abnormalities have appeared in the serum of depressed patients and in postmortem brains of suicide victims.


METHODS
We examined the gene expression of BDNF in the lymphocytes and protein expression in the platelets of adult and pediatric depressed patients during a drug-free period. We determined BDNF gene expression using a quantitative RT-PCR method and protein expression using the ELISA method.


RESULTS
We observed that the gene expression of BDNF was significantly decreased in the lymphocytes of adult and pediatric depressed patients compared with normal control subjects. Similarly, the protein expression of BDNF was significantly decreased in the platelets of adult and pediatric depressed patients compared with normal control subjects.


CONCLUSIONS
To our knowledge, this is the first study that reports a decrease in BDNF gene expression in the peripheral cells of depressed patients. Because of the bidirectional movement of BDNF between the periphery and the CNS, the reduced gene expression in the lymphocytes and the protein expression in the platelets may be an index of similar abnormalities in the brain and could be a target for antidepressant drugs.
University of Illinois at Chicago, Department of Psychiatry (MC 912), 1601 West Taylor Street, Chicago, IL 60612, United States. gpandey@psych.uic.edu
Ghanshyam N
GN
Pandey
Yogesh
Y
Dwivedi
Hooriyah S
HS
Rizavi
Xinguo
X
Ren
Hui
H
Zhang
Mani N
MN
Pavuluri
D000293:Adolescent; D000328:Adult; D001714:Bipolar Disorder / Q000097:blood* / Q000235:genetics; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood* / Q000235:genetics; D002648:Child; D003866:Depressive Disorder / Q000097:blood* / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D015870:Gene Expression; D006801:Humans; D008214:Lymphocytes / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012044:Regression Analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012720:Severity of Illness Index
D019208:Brain-Derived Neurotrophic Factor; D012333:RNA, Messenger