Low levels of alpha7-nicotinic acetylcholine receptor mRNA on peripheral blood lymphocytes in schizophrenia and its association with illness severity.
BACKGROUND
There is evidence that the nicotinic alpha7-acetylcholine receptor (alpha7-AChR) is involved in the pathophysiology of schizophrenia. Several neurotransmitter receptors, including alpha7-AChR, have been demonstrated on peripheral blood lymphocytes (PBL) and it has been suggested that these peripheral receptors may reflect corresponding brain receptors.


OBJECTIVE
In this study we compare alpha7 mRNA expression in PBL between schizophrenia patients and control individuals in order to determine whether any correlation exists between alpha7 mRNA expression in PBL and severity of schizophrenia. In addition, the isoforms of alpha7-AChR expressed are identified.


METHODS
Peripheral venous blood samples were collected from individuals with schizophrenia (n = 44) and from healthy subjects (n = 16). Symptomatology and illness severity were assessed using standard clinical psychiatric evaluation scales. RNA was prepared from isolated lymphocytes and alpha7 mRNA was measured by RT-PCR.


RESULTS
We observed a significantly lower level of alpha7 mRNA on PBLs of schizophrenia patients in comparison with healthy controls (p < 0.00). A tendency to a negative correlation was noted between the CGI score, reflecting illness severity, and the alpha7-subunit gene expression.


CONCLUSIONS
Observations confirm that the alpha7 mRNA in PBL represents the duplicated alpha7-AChR gene rather than the classic alpha7-AChR gene. Our study observations further substantiate the involvement of alpha7-AChR in the pathophysiology of schizophrenia and, while preliminary, indicate that the alpha7-AChR may be expressed and be readily measured in the peripheral blood circulation.
Perl
Orly
O
Department of Immunology, The Weizmann Institute of Science, Rehovot, Israel.
Strous
Rael D
RD
Dranikov
Angela
A
Chen
Rina
R
Fuchs
Sara
S
D000199:Actins / Q000235:genetics / Q000378:metabolism*; D000328:Adult; D000368:Aged; D002908:Chronic Disease; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D008214:Lymphocytes / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010554:Personality Disorders / Q000378:metabolism*; D020033:Protein Isoforms; D011569:Psychiatric Status Rating Scales; D012333:RNA, Messenger / Q000378:metabolism*; D011978:Receptors, Nicotinic / Q000235:genetics / Q000378:metabolism*; D012559:Schizophrenia / Q000378:metabolism*; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D064569:alpha7 Nicotinic Acetylcholine Receptor
D000199:Actins; C579167:Chrna7 protein, human; D020033:Protein Isoforms; D012333:RNA, Messenger; D011978:Receptors, Nicotinic; D064569:alpha7 Nicotinic Acetylcholine Receptor