Change of dopamine receptor mRNA expression in lymphocyte of schizophrenic patients

Abstract

BackgroundThough the dysfunction of central dopaminergic system has been proposed, the etiology or pathogenesis of schizophrenia is still uncertain partly due to limited accessibility to dopamine receptor. The purpose of this study was to define whether or not the easily accessible dopamine receptors of peripheral lymphocytes can be the peripheral markers of schizophrenia.Results44 drug-medicated schizophrenics for more than 3 years, 28 drug-free schizophrenics for more than 3 months, 15 drug-naïve schizophrenic patients, and 31 healthy persons were enrolled. Sequential reverse transcription and quantitative polymerase chain reaction of the mRNA were used to investigate the expression of D3 and D5 dopamine receptors in peripheral lymphocytes. The gene expression of dopamine receptors was compared in each group. After taking antipsychotics in drug-free and drug-naïve patients, the dopamine receptors of peripheral lymphocytes were sequentially studied 2nd week and 8th week after medication.In drug-free schizophrenics, D3 dopamine receptor mRNA expression of peripheral lymphocytes significantly increased compared to that of controls and drug-medicated schizophrenics, and D5 dopamine receptor mRNA expression increased compared to that of drug-medicated schizophrenics. After taking antipsychotics, mRNA of dopamine receptors peaked at 2nd week, after which it decreases but the level was above baseline one at 8th week. Drug-free and drug-naïve patients were divided into two groups according to dopamine receptor expression before medications, and the group of patients with increased dopamine receptor expression had more severe psychiatric symptoms.ConclusionsThese results reveal that the molecular biologically-determined dopamine receptors of peripheral lymphocytes are reactive, and that increased expression of dopamine receptor in peripheral lymphocyte has possible clinical significance for subgrouping of schizophrenis.

Dopamine D1-Like Receptor Antagonist Attenuates Th17-Mediated Immune Response and Ovalbumin Antigen-Induced Neutrophilic Airway Inflammation

“…The extent of dopamine receptor expression is different among diseases (51)(52)(53)(54)(55). For example, expression of D3 receptor is upregulated in schizophrenia (51,52).…”

“…For example, expression of D3 receptor is upregulated in schizophrenia (51,52). Expression of D2-like-R decreased in Alzheimer's disease (53).…”

Dopamine Receptor Gene (DRD1-DRD5) Expression Changes as Stress Factors Associated with Breast Cancer

“…For instance, significant decreasing in D2-D4 were reported in PBMCs of non-small cell long cancer (Shaikhpoor et al, 2012). Kwak et al (2001) were reported significant elevation in the expression level of D2 and D3 genes in schizophrenia (Kwak et al, 2001). In arthritis rheumatoid, the expression of D2 was decreased and D4 was elevated, respectively.…”

“…There are five different subtypes for dopamine receptors (DRD1-DRD5) which are classified into two families including D1-like family (stimulatory receptors) and D2-like family (inhibitory receptors) (Kirillova et al, 2008;Beaulieu and Gainetdinov, 2011). Prior studies reported that in different diseases the gene expression of dopamine receptors have been altered in immune and nervous systems (Kwak et al, 2001;Jafari et al, 2013). For instance, significant decreasing in D2-D4 were reported in PBMCs of non-small cell long cancer (Shaikhpoor et al, 2012).…”

“…Different studies showed that these receptor genes expression profiles were changed associated with chronic stress condition in various types of diseases including lupus erythematosus, schizophrenia and non-small lung cancer (Kwak et al, 2001;Shaikhpoor et al, 2012;Jafari et al, 2013). Whereas, regarding to the importance of dopamine receptors gene expression changes in pathogenesis of diseases related to chronic stress, in breast cancer patients has not been reported yet.…”