Background: There is evidence that the nicotinic α7-acetylcholine receptor (α7-AChR) is involved in the pathophysiology of schizophrenia. Several neurotransmitter receptors, including α7-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 α7 mRNA expression in PBL between schizophrenia patients and control individuals in order to determine whether any correlation exists between α7 mRNA expression in PBL and severity of schizophrenia. In addition, the isoforms of α7-AChR expressed are identified. Method: 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 α7 mRNA was measured by RT-PCR. Results: We observed a significantly lower level of α7 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 α7-subunit gene expression. Conclusion: Observations confirm that the α7 mRNA in PBL represents the duplicated α7-AChR gene rather than the classic α7-AChR gene. Our study observations further substantiate the involvement of α7-AChR in the pathophysiology of schizophrenia and, while preliminary, indicate that the α7-AChR may be expressed and be readily measured in the peripheral blood circulation.
- Nicotinic α7-acetylcholine receptor