A new single-nucleotide mutation (rs362719) of the reelin (RELN) gene associated with schizophrenia in female Chinese Han

Reelin is an extracellular signaling protein that plays an important role in the development of the central nervous system. Post-mortem studies have shown lower reelin protein levels in the brains of patients with schizophrenia and bipolar disorder compared with controls. Genetic studies have also shown that mutations in the reelin gene (RELN) increase the risk for schizophrenia and bipolar disorder. We evaluated whether an RELN gene variant, rs362719, which has been associated with increased susceptibility to bipolar disorder, is also associated with susceptibility to schizophrenia. We included 405 Chinese Han schizophrenia patients and 390 controls in our study. The polymorphism was genotyped by PCR and RFLP methods. We found a significant difference in allele frequency distribution (P< 0.05) between schizophrenia patients and controls. The frequency of the A allele was significantly higher in schizophrenia patients than in healthy controls. The effect of SNP rs362719 on allele distribution was significant in female (P < 0.05) but not in male participants (P = 0.473). Besides the gender factor, demographic and clinical characteristics of the rs362719 genotype groups were also analyzed using the chi-square test, but no significant differences were found. We conclude that rs362719 of the RELN gene is associated with susceptibility to schizophrenia in Chinese Han, possibly through a gender-specific mechanism. Further studies will be needed to confirm this genetic risk factor for schizophrenia.     

胆囊收缩素及受体基因多态性与精神分裂症的相关性研究

目的：探讨胆囊收缩素（cholecystokinin,CCK）基因、胆囊收缩素A受体（cholecystokininAreceptor。CCKAR）基因和胆囊收缩素B受体（cholecystokinin A recepmr,CCKBR）基因多态性与精神分裂症之间的相关性。方法：采用聚合酶链式反应．限制性片段长度多态性方法,对420例精神分裂症患者（病例组）和455例健康个体（对照组）三个基因的6个单核苷酸多态性（single nucleotide polymorphism,SNPs）位点（rs11571842、rs13069836、rs1800908、rs1800857、rs1042047、rs4758092）的多态性进行检测。并比较两组人群中基因型和等位基因频率分布的差异。结果：对照组6个SNPs位点的基因型频率分布均符合Hardy-Weinbere平衡（P〉0．05）;CCKAR基因rs1800857位点基因型频率分布在精神分裂症组与正常对照组间存在显著性差异（P〈0．000）,病例组T等位基因频率显著高于对照组（P〈0．01）。结论：CCKAR基因多态性与精神分裂症相关,携带T等位基因的个体可能更容易患精神分裂症。     

Monocyte chemoattractant protein-1 in schizophrenia: -2518A/G genetic variant and protein levels in Armenian population

Monocyte chemoattractant protein-1 (MCP-1) has been proposed as a contributory factor in pathophysiology of schizophrenia. The aim of the current study was to explore the possible association of the MCP-1-2518A/G genetic polymorphism and plasma levels of MCP-1 in patients with paranoid schizophrenia. The MCP-1-2518A/G (rs1024611) polymorphism and blood levels of MCP-1 in patients with paranoid schizophrenia and healthy subjects were evaluated and compared. One hundred and three chronic patients with paranoid schizophrenia treated with neuroleptics and 105 healthy subjects were genotyped using polymerase chain reaction with sequence-specific primers (PCR-SSP) and their MCP-1 plasma levels were measured by a solid-phase enzyme-linked immunosorbent assay (ELISA). When comparisons were made between patients and controls, the frequency of the MCP-1-2518*G minor allele (35% vs 23%, p=0.009, OR=1.77, 95% CI: 1.1-2.04) and also of the MCP-1-2518*G carriers (60% vs 40%, p=0.003, OR=2.27, 95% CI: 1.13-2.01) were higher in patients. The mean value of the MCP-1 plasma level in patients with schizophrenia was significantly higher than in controls. Interestingly, the patients with the GG genotype had the highest MCP-1 level (711.4 ± 211.4 pg/ml), followed by those with the AG genotype (472.1 ± 135.8 pg/ml) and AA (372.4 ± 180.2 pg/ml) homozygotes. In conclusion, we report here the association of the -2518A/G genetic polymorphism and increased plasma levels of MCP-1 with schizophrenia and nominate -2518*G minor allele as a risk factor for schizophrenia in Armenian population.     

Glycogen Synthase Kinase-3 and Omi/HtrA2 Induce Annexin A2 Cleavage followed by Cell Cycle Inhibition and Apoptosis

Annexin A2 is involved in multiple cellular processes, including cell survival, growth, division, and differentiation. A lack of annexin A2 makes cells more sensitive to apoptotic stimuli. Here, we demonstrate a potential mechanism for apoptotic stimuli-induced annexin A2 cleavage, which contributes to cell cycle inhibition and apoptosis. Annexin A2 was persistently expressed around the proliferative but not the necrotic region in BALB/c nude mice with human lung epithelial carcinoma cell A549-derived tumors. Knockdown expression of annexin A2 made cells susceptible to either serum withdrawal-induced cell cycle inhibition or cisplatin-induced apoptosis. Under apoptotic stimuli, annexin A2 was time-dependently cleaved. Mechanistic studies have shown that protein phosphatase 2A (PP2A)-activated glycogen synthase kinase (GSK)-3 is essential for this process. Therefore, inhibiting GSK-3 reversed serum withdrawal-induced cell cycle inhibition and cisplatin-induced apoptosis. Furthermore, inhibiting serine proteases blocked apoptotic stimuli-induced annexin A2 cleavage. Bax activation and Mcl-1 destabilization, which is regulated by PP2A and GSK-3, caused annexin A2 cleavage via an Omi/HtrA2-dependent pathway. Taking these results together, we conclude that GSK-3 and Omi/HtrA2 synergistically cause annexin A2 cleavage and then cell cycle inhibition or apoptosis.     

Flow cytometric scoring of apoptosis compared to electron microscopy in gamma irradiated lymphocytes

One of the early events occurring at the cell membrane during apoptosis is the translocation of phosphatidylserine from the inner side of the plasma membrane to the outer layer. These phosphatidylserine groups can be bound by fluorescein isothiocyanate (FITC)-labelled annexin V. The aim of this study was to evaluate the power of the annexin V flow cytometric assay in detecting apoptosis in gamma irradiated peripheral blood lymphocytes and in differentiating between apoptosis and primary necrosis in these cells. Therefore, 5 Gy and 20 Gy gamma irradiated peripheral blood mononuclear cells (PBMCs) were examined after a 24-h culture period. The terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) technique was performed as well. A comparison with an electron microscopic (EM) evaluation was made. EM is based on established morphological criteria allowing the classification of cells into four groups: viable, early apoptotic, secondary necrotic and primary necrotic cells. EM performed on annexin V positive sorted cells proved that a 5 Gy gamma irradiation of PBMCs mainly causes apoptosis, whereas a 20 Gy gamma irradiation mainly induces primary necrosis. Neither the annexin V flow cytometric assay nor the TUNEL assay were able to distinguish between primary and secondary necrotic cells. These results illustrate that if quantification of apoptosis is required, one should be careful in interpreting flow cytometric results obtained by annexin V or TUNEL staining in peripheral blood lymphocytes. Although in general primary necrotic cells show an increased forward scatter due to cellullar swelling, both early apoptotic and necrotic (primary or secondary) lymphocytes show a decreased forward scatter signal. Moreover, both primary and secondary necrotic lymphocytes are annexin V and propidium iodide (PI) positive and therefore indistinguishable. We conclude that if a new experiment focusing on apoptosis is set up, an initial EM evaluation is mandatory. If EM shows that the apoptosis inducing agent used in the design of the experiments is not causing primary necrosis, than the annexin V flow cytometric assay can provide rapid and quantitative information about apoptosis.     

Cortical Surface Area Correlates with STON2 Gene Ser307Pro Polymorphism in First-Episode Treatment-Na?ve Patients with Schizophrenia

Background

Evidence shows that STON2 gene is associated with synaptic function and schizophrenia. This study aims to explore the relationship between two functional polymorphisms (Ser307Pro and Ala851Ser) of STON2 gene and the cortical surface area in first-episode treatment-naïve patients with schizophrenia and healthy controls.

Methodology/Principal Findings

Magnetic resonance imaging of the whole cortical surface area, which was computed by an automated surface-based technique (FreeSurfer), was obtained from 74 first-episode treatment-naïve patients with schizophrenia and 55 healthy controls. Multiple regression analysis was performed to investigate the effect of genotype subgroups on the cortical surface area. A significant genotype-by-diagnosis effect on the cortical surface area was observed. Pro-allele carriers of Ser307Pro polymorphism had larger right inferior temporal surface area than Ser/Ser carriers in the patients with schizophrenia; however, no significant difference was found in the same area in the healthy controls. The Ala851Ser polymorphism of STON2 gene was not significantly associated with the cortical surface area in patients with schizophrenia and healthy controls.

Conclusions/Significance

The present study demonstrated that the functional variant of the STON2 gene could alter cortical surface area on the right inferior temporal and contribute to the pathogenesis of schizophrenia.     

Annexin A5 inhibits engulfment through internalization of PS-expressing cell membrane patches

Apoptosis and subsequent clearance of apoptotic cells are important for the prevention of diseases. Therefore, it is essential to understand the mechanisms underlying the biology of phagocytic clearance of apoptotic cells. The best characterized "eat me" signal on the surface of apoptotic cells is phosphatidylserine (PS). Recently, we demonstrated that annexin A5 mediates the internalization of PS-expressing membrane patches and down regulates surface expression of tissue factor. Here, we investigated the role of PS in the phagocytosis of apoptotic cells using annexin A5. Using a novel flow cytometric-based phagocytosis assay, we observed that engulfment was inhibited with 20% if annexin A5 was added to PS-expressing cells that had completed apoptosis. The inhibition increased to more than 50% if annexin A5 was added during the apoptotic process. This inhibition is specific for annexin A5, since the mutant M23 and annexin A1 did not further increase the inhibition of phagocytosis when added during the apoptotic process. Interestingly, cells with internalized annexin A5 still express PS at their surface. We conclude that other ligands within the PS-expressing membrane patch act together with PS as an "eat me" signal.     

Membrane polyunsaturated fatty acids and CSF cytokines in patients with schizophrenia

Findings to date provide evidence that altered membrane structure and function are present in patients with either first-episode or chronic schizophrenia, suggesting defects in phospholipid metabolism and cell signaling in schizophrenia. The purpose of this investigation is to test whether decreased membrane polyunsaturated fatty acids (PUFAs) were associated with an increased secretion of proinflammatory cytokines. Thus, we measured interleukin 6 (IL-6) and interleukin 10 (IL-10) in cerebrospinal fluid (CSF) of patients with chronic schizophrenia as well as PUFAs of red blood cell (RBC) membranes from the same individuals. A significant and inverse correlation was found between CSF IL-6 (not IL-10) and RBC membrane PUFAs levels in both haloperidol-treated and medication-free patients with schizophrenia. Specifically, such an association was found in the n-6 (18:2, 20:4, and 22:4) and, to a lesser extent, the n-3 fatty acids. Taken together, the present findings suggest that decreased membrane PUFAs may be related to an immune disturbance in schizophrenia, possibly resulting from an increased phospholipase A2 activity mediated through the proinflammatory cytokines.     

Association of serotonin 2A receptor and lack of association of CYP1A2 gene polymorphism with tardive dyskinesia in a Turkish population

The aim of this study was to investigate the possible association of serotonin 2A receptor gene (HTR2A) -1438 G/A polymorphism and CYP1A2 gene 163C/A polymorphism with tardive dyskinesia (TD) in a Turkish population. A total of 47 patients with persistent TD, 80 patients who were consistently without TD, and 100 healthy controls were included in this study. The polymorphic regions of -1438 G/A polymorphism of HTR2A receptor gene (rs6311) and 163C/A of CYP1A2 (rs762551) gene were amplified using polymerase chain reaction (PCR), followed by digestion with restriction enzymes MspI and Bsp1201. Genotype and allele frequencies were calculated by the chi(2)-test. Crude and adjusted odds ratios (ORs) were estimated, and 95% confidence intervals (CIs) were computed by multivariate logistic regression analysis. The genotype and allele frequencies of HTR2A and CYP1A2 gene were similar in schizophrenia with TD, schizophrenia without TD, and healthy controls. The logistic regression analysis showed that cumulative exposure to antipsychotic drugs for every year (p = 0.003; OR = 1.15; CI = 1.07-1.23), and AA genotype of HTR2A gene (p = 0.0258; OR = 4.34; CI = 1.19-15.81) are risk factors for TD. The same logistic regression model showed no association between CYP1A2 polymorphism and TD. The results of the present study seem to indicate that HTR2A gene polymorphism influences the tendency to express TD following prolonged antipsychotic drug exposure in Turkish schizophrenia patients.     

HSP70 polymorphisms in first psychotic episode drug-naïve schizophrenic patients

Aims

The aim of this study is to investigate differences in HSPA8 polymorphisms between first-episode psychotic (FEP) schizophrenic patients and healthy participants after adjustment for temperamental personality traits.

Main methods

This study included fifty drug-naive schizophrenic patients with an FEP and fifty healthy participants who served as controls. Genotyping of HSPA8 polymorphisms was performed in patients and healthy subjects as well. Personality characteristics were assessed using the standardized Greek version of the Alternative Five-Factor Zuckerman–Kuhlman Personality Questionnaire (ZKPQ).

Key findings

Our results showed that FEP patients presented a polymorphism differentiation related to the HSPA8 gene (rs1136141), and a higher frequency of T carriers compared to healthy controls was observed. The HSP8A polymorphism and the levels of Neuroticism as measured by the Alternative Five-Factor ZKPQ were the variables most closely and independently associated with FEP in multiple logistic regression analysis, and the odds of being assessed with a FEP was 2.8 times greater in T carriers compared to non-carriers.

Significance

Present findings indicate a role of HSP8A in FEP and underline the importance of including personality traits in the study of the factors associated with the development of schizophrenia.     

Genetic variants of GRIA1 are associated with susceptibility to schizophrenia in Korean population

The α-amino-3-hydroxy-5-methyl-4-propionic acid (AMPA) receptors are important for glutamate synaptic transmission in the central nervous system. Glutamate receptor, ionotropic, AMPA receptor 1 gene (GRIA1) belongs to the family of AMPA receptors. There is increasing evidence that AMPA receptors dysfunction may be related to an increased susceptibility to schizophrenia. The aim of this study was therefore to investigate whether genetic polymorphisms of GRIA1 are associated with schizophrenia and their clinical symptoms (hallucinations and delusions) in Korean population. Five single nucleotide polymorphisms (rs1428920, rs1552834, rs1422889, rs10035143, and rs2926835) of the GRIA1 were genotyped in 218 schizophrenia patients and 380 healthy controls, using a direct sequencing. All patients were evaluated by the Operational Criteria Checklist for Psychotic Illness. The genotype and allelic frequencies of rs1428920 and rs2926835 showed significant association between schizophrenia and controls (rs1428920, permutation p?=?0.008, 0.008; rs2926835, permutation p?=?0.038, 0.041, respectively). A significantly increased risk of schizophrenia was associated with the A allele of rs1428920 and rs2926835 of GRIA1. Furthermore, we found that rs1428920 was weakly associated with hallucinations of schizophrenia, but this significance disappeared after multiple testing (permutation p?=?0.119). These results suggest that GRIA1 polymorphism may have influence upon the risk of developing schizophrenia.     

Genetic variability in sodium-glucose cotransporter 2 influences glycemic control and risk for diabetic retinopathy in type 2 diabetes patients

BackgroundGluconeogenesis and renal glucose excretion in kidneys both play an important role in glucose homeostasis. Sodium-glucose cotransporter (SGLT2), coded by the SLC5A2 gene is responsible for reabsorption up to 99% of the filtered glucose in proximal tubules. SLC5A2 genetic polymorphisms were suggested to influence glucose homeostasis. We investigated if common SLC5A2 rs9934336 polymorphism influences glycemic control and risk for macro or microvascular complications in Slovenian type 2 diabetes (T2D) patients.MethodsAll 181 clinically well characterized T2D patients were genotyped for SLC5A2 rs9934336 G>A polymorphism. Associations with glycemic control and T2D complications were assessed with nonparametric tests and logistic regression.ResultsSLC5A2 rs9934336 was significantly associated with increased fasting blood glucose levels (P<0.001) and HbA1c levels under the dominant genetic model (P=0.030). After adjustment for T2D duration, significantly higher risk for diabetic retinopathy was present in carriers of at least one polymorphic SLC5A2 rs9934336 A allele compared to non-carriers (OR=7.62; 95%CI=1.65-35.28; P=0.009).ConclusionsOur pilot study suggests an important role of SLC5A2 polymorphisms in the physiologic process of glucose reabsorption in kidneys in T2D patients. This is also the first report on the association between SLC5A2 polymorphism and diabetic retinopathy.     

Purinergic P2X7 receptor functional genetic polymorphisms are associated with the susceptibility to osteoporosis in Chinese postmenopausal women

Osteoporosis (OP) is a major public health problem worldwide. Genetic factors are considered to be major contributors to the pathogenesis of OP. The purinergic P2X7 receptor (P2X7R) has been shown to play a role in the regulation of osteoblast and osteoclast activity and has been considered as an important candidate gene for OP. A case–control study was performed to investigate the associations of functional single nucleotide polymorphisms (SNPs) in the P2X7R gene (rs2393799, rs7958311, rs1718119, rs2230911, and rs3751143) with susceptibility to OP in 400 Chinese OP patients and 400 controls. Results showed that rs3751143 was associated with OP; in particular, carriers of the C allele and CC/(AC + CC) genotypes were at a higher risk of OP, but no significant association of rs2230911, rs7958311, rs1718119, and rs2393799 with OP risk was observed. Analysis of the haplotypes revealed one haplotype (rs1718119G-rs2230911G-rs3751143C) that appeared to be a significant “risk” haplotype with OP. The rs3751143 polymorphism was associated with osteoclast apoptosis; ATP-induced caspase-1 activity of osteoclasts with AC and CC genotypes is lower than that of osteoclasts with AA genotype in vitro. The findings suggest that the P2X7R rs3751143 functional polymorphism might contribute to OP susceptibility in Chinese postmenopausal women.     

Non-fusion expression in Escherichia coli: Single-step purification of recombinant human annexin A5 for detection of apoptosis

Recombinant human annexin A5 (rh-annexin A5) was originally used to detect early stages of apoptosis in vitro. With the development of radioactive labeling and imaging techniques, annexin A5 labeled with radioactive markers can play a more important role in monitoring apoptotic cells in vivo. To obtain highly pure rh-annexin A5 with an easy and inexpensive purification approach, we constructed a pJLA503-annexin A5 expression plasmid, which could overexpress human annexin A5 in a soluble form in Escherichia coli. Then a novel purification method based on Ca2+-dependent phosphatidylserine (PS)-binding activity was established, whereby the purity of rh-annexin A5 was increased to 98%. To confirm the PS affinity of rh-annexin A5 produced by this purification protocol, a simple and reliable lipid membrane model was prepared and used in the binding test. As a probe to detect apoptosis, the fluorescein isothiocyanate-labeled rh-annexin A5 was incubated with apoptotic cells. The results showed that the labeled rh-annexin A5 possessed high affinity for PS molecule and was able to indicate different apoptotic states.     

Increased production of TGF-beta and apoptosis of T lymphocytes isolated from peripheral blood in COPD

Chronic obstructive pulmonary disease (COPD) is associated with inflammation of airway epithelium, including an increase in the number of intraepithelial T cells. Increased apoptosis of these T cells has been reported in the airways in COPD, and although this process is critical for clearing excess activated T cells, excessive rates of apoptosis may result in unbalanced cellular homeostasis, defective clearance of apoptotic material by monocytes/macrophages, secondary necrosis, and prolongation of the inflammatory response. Lymphocytes are known to traffic between the airway and the peripheral circulation, thus we hypothesized that in COPD, circulating T cells may show an increased propensity to undergo apoptosis. We analyzed phytohemagglutinin (PHA)-stimulated peripheral blood T cells from COPD patients and controls for apoptosis using flow cytometry and staining with annexin V and 7-aminoactinomycin D. As several pathways are involved in induction of apoptosis of T cells, including transforming growth factor (TGF)-beta/TGF receptor (TGFR), TNF-alpha/TNFR1, and Fas/Fas ligand, these mediators were also investigated in peripheral blood samples from these subject groups. Significantly increased apoptosis of PHA-stimulated T cells was observed in COPD (annexin positive 75.0 +/- 14.7% SD vs. control 50.2 +/- 21.8% SD, P = 0.006), along with upregulation of TNF-alpha/TNFR1, Fas, and TGFR. Monocyte production of TGF-beta was also increased. In conclusion we have demonstrated the novel finding of increased apoptosis of stimulated T cells in COPD and have also shown that the increased T-cell death may be associated with upregulation of apoptotic pathways, TGF-beta, TNF-alpha, and Fas in the peripheral blood in COPD.     

The CD40 gene polymorphism rs1883832 is associated with risk of acute coronary syndrome in a Chinese case-control study

Numerous reports in the past few years have demonstrated that atherosclerosis is a lipid-driven, chronic inflammatory disease of the vessel. Recent studies have indicated that the immune mediator CD40-CD40L (CD40 ligand), which is expressed on several inflammatory cells within human atherosclerotic lesions, has roles in atherogenesis. A functional polymorphism (-1C>T, rs1883832) in the 5' untranslated region of TNFRSF5 gene has been reported to affect CD40 expression and be associated with several chronic inflammatory and autoimmune diseases. The aim of the present study was to validate the potential coronary artery disease susceptibility marker in a Chinese case-control study. A total of 160 patients with acute coronary syndrome (ACS) and 180 control subjects were used to genotype and identify this single-nucleotide polymorphism by polymerase chain reaction-restriction fragment length polymorphism and sequencing, respectively. Peripheral blood mononuclear cells were isolated and incubated with interferon-γ with or without pretreatment of fluvastatin, followed by measurement of CD40 expression using flow cytometry. In addition, soluble CD40L was determined by ELISA as another biomarker of coronary artery disease. The distribution of the rs1883832 genotypes (CC, CT, and TT) was 33.1%, 54.4%, and 12.5% in the ACS group and 22.8%, 53.3%, and 23.9% in controls, respectively. The frequency of the C allele was significantly higher among ACS patients compared with controls (60.3% vs. 49.4%, odds ratio=1.554, 95% confidence intervals: 1.146-2.107, p<0.05). ACS patients showed a significant increase of CD40 and sCD40L coexpression compared with controls (p<0.05). Cell culture experiments showed that CC carriers presented significantly higher CD40 expression levels than CT and TT subjects (p<0.05). Additionally, fluvastatin suppressed CD40 expression in all three genotypes. These data suggest that the single-nucleotide polymorphism of CD40 gene is associated with susceptibility to ACS in Chinese population, and the polymorphism may influence the CD40 production. These expand the understanding of inflammatory mechanisms during atherogenesis.     

Annexin V/beta5 integrin interactions regulate apoptosis of growth plate chondrocytes

Apoptosis of terminally differentiated chondrocytes allows the replacement of growth plate cartilage by bone. Despite its importance, little is known about the regulation of chondrocyte apoptosis. We show that overexpression of annexin V, which binds to the cytoplasmic domain of beta5 integrin and protein kinase C alpha (PKCalpha), stimulates apoptotic events in hypertrophic growth plate chondrocytes. To determine whether the balance between the interactions of annexin V/beta5 integrin and annexin V/active PKCalpha play a role in the regulation of terminally differentiated growth plate chondrocyte apoptosis, a peptide mimic of annexin V (Penetratin (Pen)-VVISYSMPD) that binds to beta5 integrin but not to PKCalpha was used. This peptide stimulated apoptotic events in growth plate chondrocytes. Suppression of annexin V expression using small interfering ribonucleic acid decreased caspase-3 activity and increased cell viability in Pen-VVISYSMPD-treated growth plate chondrocytes. An activator of PKC resulted in a further decrease of cell viability and further increase of caspase-3 activity in Pen-VVISYSMPD-treated growth plate chondrocytes, whereas inhibitors of PKCalpha led to an increase of cell viability and decrease of caspase-3 activity of Pen-VVISYSMPD-treated cells. These findings suggest that binding of annexin V to active PKCalpha stimulates apoptotic events in growth plate chondrocytes and that binding of annexin Vto beta5 integrin controls these interactions and ultimately apoptosis.     

Assessment of cardiovascular apoptosis in the isolated rat heart by magnetic resonance molecular imaging

Apoptosis, an active process of cell self-destruction, is associated with myocardial ischemia. The redistribution of phosphatidylserine (PS) from the inner to the outer leaflet of the cell membrane is an early event in apoptosis. Annexin V, a protein with high specificity and tight binding to PS, was used to identify and localize apoptosis in the ischemic heart.Fluorescein-labeled annexin V has been used routinely for the assessment of apoptosis in vitro. For the detection of apoptosis in vivo, positron emission tomography and single-photon emission computed tomography have been shown to be suitable tools. In view of the relatively low spatial resolution of nuclear imaging techniques, we developed a high-resolution contrast-enhanced magnetic resonance imaging (MRI) method that allows rapid and noninvasive monitoring of apoptosis in intact organs. Instead of employing superparamagnetic iron oxide particles linked to annexin V, a new T1 contrast agent was used. To this effect, annexin V was linked to gadolinium diethylenetriamine pentaacetate (Gd-DTPA)-coated liposomes.The left coronary artery of perfused isolated rat hearts was ligated for 30 min followed by reperfusion. T(1) and T(2)* images were acquired by using an 11.7-T magnet before and after intracoronary injection of Gd-DTP-labeled annexin V to visualize apoptotic cells. A significant increase in signal intensity was visible in those regions containing cardiomyocytes in the early stage of apoptosis. Because labeling of early apoptotic cell death in intact organs by histological and immunohistochemical methods remains challenging, the use of Gd-DTPA-labeled annexin V in MRI is clearly an improvement in rapid targeting of apoptotic cells in the ischemic and reperfused myocardium.     

The ALDH2 rs671 Polymorphism Affects Post-Stroke Epilepsy Susceptibility and Plasma 4-HNE Levels

Recent studies have demonstrated the protective effect of mitochondrial aldehyde dehydrogenase 2 (ALDH2) in cardiovascular diseases. Increased levels of the potential ALDH2 substrate 4-hydroxynonenal (4-HNE) are involved in myocardial/cerebral ischemia accompanied by a high level of oxidative stress. In this investigation, we first performed a case-control study to explore the potential association of ALDH2 rs671 polymorphism and post-stroke epilepsy (PSE). Then, we performed an in vitro study to determine whether the overexpression of ALDH2 could decrease the level of oxidative stress and the apoptosis ratio induced by 4-HNE. There was a significant difference in the distribution of the allele and genotype frequencies of the rs671 polymorphism between PSE patients and ischemic stroke (IS) patients. Individuals with the rs671 A allele showed significantly higher levels of plasma 4-HNE. The overexpression of ALDH2 partially blocked the increased levels of malondialdehyde (MDA), reactive oxygen species (ROS) and apoptosis ratio induced by 4-HNE and also partially restored the ALDH2 activity in PC12 cells; these effects were reversed in the presence of εV1-2. Our results suggest that the ALDH2 rs671 polymorphism is associated with PSE susceptibility and affects the 4-HNE levels. Targeting ALDH2 might be a useful strategy for the treatment or prevention of PSE.     

No evidence for association between DRD3 and COMT with schizophrenia in a Malay population

Molecular components of the dopamine D3 receptor (DRD3) may play an important role in the pathophysiology of schizophrenia. Previous studies have demonstrated an association between DRD3 Ser9Gly and cathechol-o-methyltransferase (COMT, SNP = rs165656) polymorphisms and schizophrenia but the results were inconclusive. We investigated this apparent association between Ser9Gly (A/G) polymorphism and an intronic SNP (dbSNP or rs165656) in 261 Malay patients diagnosed with schizophrenia and 216 controls, using PCR-RFLP. The genotype distribution of the polymorphism DRD3 Ser9Gly was in Hardy-Weinberg equilibrium (HWE) for patients (P = 0.1251) and out of HWE for controls (P = 0.0137). However, both healthy controls and schizophrenia patients were out of HWE for the polymorphism COMT rs165656. Based on allele and genotype frequencies in both groups, we found no significant association of DRD3 Ser9Gly polymorphisms and COMT (rs165656) with schizophrenia in Malays. Further studies should examine the association between other dopamine-related genes and the behavioral phenotypes of schizophrenia.