Association between ghrelin gene (GHRL) polymorphisms and clinical response to atypical antipsychotic drugs in Han Chinese schizophrenia patients.

BACKGROUND: Ghrelin (GHRL) is a pivotal peptide regulator of food intake, energy balance, and body mass. Weight gain (WG) is a common side effect of the atypical antipsychotics (AAPs) used to treat schizophrenia (SZ). Ghrelin polymorphisms have been associated with pathogenic variations in plasma lipid concentrations, blood pressure, plasma glucose, and body mass index (BMI). However, it is unclear whether GHRL polymorphisms are associated with WG due to AAPs. Furthermore, there is no evidence of an association between GHRL polymorphisms and SZ or the therapeutic response to AAPs. We explored these potential associations by genotyping GHRL alleles in SZ patients and controls. We also examined the relation between these SNPs and changes in metabolic indices during AAP treatment in SZ subgroups distinguished by high or low therapeutic response. METHODS: Four SNPs (Leu72Met, -501A/C, -604 G/A, and -1062 G > C) were genotyped in 634 schizophrenia patients and 606 control subjects. RESULTS: There were no significant differences in allele frequencies, genotype distributions, or the distributions of two SNP haplotypes between SZ patients and healthy controls (P > 0.05). There was also no significant difference in symptom reduction between genotypes after 8 weeks of AAP treatment as measured by positive and negative symptom scale scores (PANSS). However, the -604 G/A polymorphism was associated with a greater BMI increase in response to AAP administration in both APP responders and non-responders as distinguished by PANSS score reduction (P < 0.001). There were also significant differences in WG when the responder group was further subdivided according to the specific AAP prescribed (P < 0.05). CONCLUSIONS: These four GHRL gene SNPs were not associated with SZ in this Chinese Han population. The -604 G/A polymorphism was associated with significant BW and BMI increases during AAP treatment. Patients exhibiting higher WG showed greater improvements in positive and negative symptoms than patients exhibiting lower weight gain or weight loss.

Association study of RELN polymorphisms with schizophrenia in Han Chinese population.

Schizophrenia (SZ) is a common and complex psychiatric disorder with a strong genetic component. Previous research suggests that mutations altering genes in neurodevelopmental pathways contribute to SZ. Reelin gene (RELN) maps to chromosome 7q22.1, the encoded protein plays a pivotal role in guiding neuronal migration, lamination and connection during embryonic brain development. Several reports had indicated that reduced RELN expression is associated with human mental illnesses such as SZ, mood disorders and autism. In this study, case-control association analyses were performed in the Han Chinese population to determine if the RELN gene is a susceptibility gene for SZ. Thirty-seven single nucleotide polymorphisms (SNPs) were genotyped in 528 paranoid SZ patients and 528 control subjects. A significant association was found between rs12705169 and SZ (p=0.001). Moreover, the haplotypes constructed from five SNPs showed significant differences between cases and controls (p=0.041). When subjects were divided by gender, rs12705169 remained significant difference only in females (OR=0.24, 95%CI=0.14-0.40 for CC and OR=0.40, 95%CI=0.27-0.58 for AC), both in the allele and genotype (p=0.0001 for both). This study describes a positive association between RELN and SZ in the Han Chinese population, and provides genetic evidence to support the gender difference of SZ.

[Effect of pyrrolidinedithiocarbamate on neural developmental disorder of adult offspring with maternal systemic exposure to Poly(I:C) during pregnancy].

OBJECTIVE: To explore the correlation between the elevated expression of cytokines under the induction of Poly(I:C) (polycytidylic acid) in maternal hosts and the abnormal behaviors of adult offsprings and understand the intervening effects of nuclear factor NF-κB inhibitor pyrrolidinedithiocarbamate (PDTC). METHODS: Poly(I:C) or saline was administered to model the maternal infection during early pregnancy in rats. And the expression of cytokines was blocked with PDTC. The maternal levels of tumor necrosis factor alpha and interleukin-10 were determined by ELISA (enzyme-linked immunosorbent assay). The adult offsprings on different treatments were then compared with regards to prepulse inhibition (PPI), passive avoidance and active avoidance. RESULTS: After the administration of Poly(I:C), there was an elevated levels of serum cytokines as shown by the markedly increased serum levels of IL-10 and TNF-α. The serum levels of IL-10 and TNF-α in the model group were significantly higher than those in the control group [(18.26 ± 1.52) pg/ml, (119.64 ± 16.42) pg/ml vs. (0.16 ± 0.13) pg/ml and (11.21 ± 1.81) pg/ml]. The elevation was partly blocked by PDTC. The serum levels of IL-10 and TNF-α in the intervention group [(12.64 ± 2.04) pg/ml and (30.34 ± 2.19) pg/ml respectively] were lower than those in the model group, but still higher than those in the control group. The psychotic-like phenotypes including defects in PPI, passive avoidance and active avoidance were observed in Poly(I:C)-treated offsprings. Such an effect was blunted by the PDTC intervention. The PPI results demonstrated that the PP2 and PP8 difference between rats in 3 groups were statistically significant, with a lower PPI value in the model group than in the intervention group, in the intervention group than in the control group and much lower in the model group than in the control group. PP4 was lower in the model group than that in the intervention group, and also lower in the model group than in the control group. There was no significant difference between the control group and the intervention group. The passive avoidance results indicated that T1 was higher in the model group than in the control and intervention groups and there was no statistical difference between the control and intervention groups. T2 was lower in the model group than in the control and intervention groups and there was no statistical difference between the control and intervention groups. And the active avoidance test results showed that total conditioned reflex times of the control group was higher than those of the intervention and model groups. No statistical difference was found between the intervention and model groups. Total reflex rate of the control group was higher than that of the intervention and model groups. No statistical difference was found between the intervention and model groups. CONCLUSION: PDTC can interfere with neural developmental disorder of adult offsprings through blunting the cytokine-mediated maternal immune response.

The nuclear factor-κB inhibitor pyrrolidine dithiocarbamate reduces polyinosinic-polycytidilic acid-induced immune response in pregnant rats and the behavioral defects of their adult offspring.

BACKGROUND: Epidemiological studies have indicated that maternal infection during pregnancy may lead to a higher incidence of schizophrenia in the offspring. It is assumed that the maternal infection increases the immune response, leading to neurodevelopmental disorders in the offspring. Maternal polyinosinic-polycytidilic acid (PolyI:C) treatment induces a wide range of characteristics in the offspring mimicking some schizophrenia symptoms in humans. These observations are consistent with the neurodevelopmental hypothesis of schizophrenia. METHODS: We examined whether suppression of the maternal immune response could prevent neurodevelopmental disorders in adult offspring. PolyI:C or saline was administered to early pregnant rats to mimic maternal infection, and the maternal immune response represented by tumor necrosis factor alpha (TNF-α) and interleukin-10 (IL-10) levels was determined by enzyme-linked immunosorbent assays (ELISA). The NF-κB inhibitor pyrrolidine dithiocarbamate (PDTC) was used to suppress the maternal immune response. Neurodevelopmental disorders in adult offspring were examined by prepulse inhibition (PPI), passive avoidance, and active avoidance tests. RESULTS: PolyI:C administration to early pregnant rats led to elevated serum cytokine levels as shown by massive increases in serum TNF-α and IL-10 levels. The adult offspring showed defects in prepulse inhibition, and passive avoidance and active avoidance tests. PDTC intervention in early pregnant rats suppressed cytokine increases and reduced the severity of neurodevelopmental defects in adult offspring. CONCLUSIONS: Our findings suggest that PDTC can suppress the maternal immune response induced by PolyI:C and partially prevent neurodevelopmental disorders of adult offspring.