Journal of Negative Results in BioMedicine - Latest Articles

In vitro studies of the influence of glutamatergic agonists on the Na+,K+-ATPase and K+-p-nitrophenylphosphatase activities in the hippocampus and frontal cortex of rats

Marcos Contó — 2012-05-10T00:00:00Z

Background: The overstimulation of excitatory glutamatergic neurotransmission and the inhibition of Na+,K+-ATPase enzymatic activity have both been implicated in neurotoxicity and are possibly related to the pathogenesis of epilepsy and neurodegenerative disorders. In the present study, we investigated whether glutamatergic stimulation by the glutamatergic agonists glutamate, alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid (AMPA), kainate and N-methyl-D-aspartate (NMDA) modulates the Na+,K+-ATPase and the K+-p-nitrophenylphosphatase activities in the crude synaptosomal fraction of the hippocampus and the frontal cortex of rats. Results: Our results demonstrated that these glutamatergic agonists did not influence the activities of Na+,K+-ATPase or K+-p-nitrophenylphosphatase in the brain structures analyzed. Assays with lower concentrations of ATP to analyze the preferential activity of the Na+,K+-ATPase isoform with high affinity for ATP did not show any influence either. Conclusions: These findings suggest that under our experimental conditions, the stimulation of glutamatergic receptors does not influence the kinetics of the Na+,K+-ATPase enzyme in the hippocampus and frontal cortex.

Lifestyle counselling during pregnancy and offspring weight development until four years of age: follow-up study of a controlled trial

Taina Mustila — 2012-05-08T00:00:00Z

Background: Fetal conditions are known to be partly responsible for the child's risk for obesity. Our pilot study aimed to determine the effect of gestational lifestyle counseling on the offspring weight gain until 4 years of age and to estimate power for future studies.Design and methodsFirst-time pregnant mothers participated in a controlled trial conducted in maternity health clinics during 2004 - 2006. The intervention included individual counseling on physical activity and diet, and an option to attend supervised group exercise sessions. The participant mothers (N = 109) received a follow-up questionnaire concerning 13 repeated growth measurements of their offspring. Response rate to the follow-up questionnaire was 66.1% (N = 72/109). Results: The increase of BMI z-score between 24 - 48 months was not significantly slower among the intervention group offspring (95% CI -0.025 to 0.009, p = 0.34) compared to control group. Z-scores for weight-for-length/height did not differ between groups when the period 0 - 48 months was analyzed (95% CI -0.010 to 0.014, p = 0.75). Conclusions: In this pilot study gestational lifestyle counseling did not significantly slow the weight gain of the offspring. Gestational intervention studies with at least 300 mothers per group are needed to confirm the possible effect on offspring's risk for obesity.Trial registrationCurrent Controlled Trials ISRCTN21512277.

Protein kinase A enhances lipopolysaccharide-induced IL-6, IL-8, and PGE2 production by human gingival fibroblasts.

Toshiaki Ara — 2012-03-27T00:00:00Z

ObjectivePeriodontal disease is accompanied by inflammation of the gingiva and destruction of periodontal tissues, leading to alveolar bone loss in severe clinical cases. Interleukin (IL)-6, IL-8, and the chemical mediator prostaglandin E2 (PGE2) are known to play important roles in inflammatory responses and tissue degradation.Recently, we reported that the protein kinase A (PKA) inhibitor H-89 suppresses lipopolysaccharide (LPS)-induced IL-8 production by human gingival fibroblasts (HGFs). In the present study, the relevance of the PKA activity and two PKA-activating drugs, aminophylline and adrenaline, to LPS-induced inflammatory cytokines (IL-6 and IL-8) and PGE2 by HGFs were examined. Methods: HGFs were treated with LPS from Porphyromonas gingivalis and H-89, the cAMP analog dibutyryl cyclic AMP (dbcAMP), aminophylline, or adrenaline. After 24 h, IL-6, IL-8, and PGE2 levels were evaluated by ELISA. Results: H-89 did not affect LPS-induced IL-6 production, but suppressed IL-8 and PGE2 production. In contrast, dbcAMP significantly increased LPS-induced IL-6, IL-8, and PGE2 production. Up to 10 microg/ml of aminophylline did not affect LPS-induced IL-6, IL-8, or PGE2 production, but they were significantly increased at 100 microg/ml. Similarly, 0.01 microg/ml of adrenaline did not affect LPS-induced IL-6, IL-8, or PGE2 production, but they were significantly increased at concentrations of 0.1 and 1 microg/ml. In the absence of LPS, H-89, dbcAMP, aminophylline, and adrenaline had no relevance to IL-6, IL-8, or PGE2 production. Conclusion: These results suggest that the PKA pathway, and also PKA-activating drugs, enhance LPS-induced IL-6, IL-8, and PGE2 production by HGFs. However, aminophylline may not have an effect on the production of these molecules at concentrations used in clinical settings (8 to 20 microg/ml in serum). These results suggest that aminophylline does not affect inflammatory responses in periodontal disease.

TGFBR3 Variation is not a Common Cause of Marfan-like Syndrome and Loeys-Dietz-like Syndrome

Krishna Singh — 2012-02-02T00:00:00Z

Marfan syndrome (MFS) is caused by mutations in the fibrillin-1 (FBN1) gene, and mutations in FBN1 are known to be responsible for over 90% of all MFS cases. Locus heterogeneity has also been reported and confirmed, with mutations in the receptor genes TGFBR1 and TGFBR2 identified in association with MFS-related phenotypes. It is now known that dysregulation of TGF-ß signaling is involved in MFS pathogenesis. To test the hypothesis that dysregulation of TGFBR3-associated TGF-ß signaling is implicated in MFS or related phenotype pathogenesis, we selected a cohort of 49 patients, fulfilling or nearly fulfilling the diagnostic criteria for MFS. The patients were known not to carry a mutation in the FBN1 gene (including three 5' upstream alternatively spliced exons), the TGFBR1 and TGFBR2 genes. Mutation screening for the TGFBR3 gene in these patients and in controls led to the identification of a total of ten exonic (one novel), four intronic (one novel) and one 3'UTR variant in the TGFBR3 gene. Our data suggest that variations in TGFBR3 gene appear not to be associated with MFS or related phenotype.

Metallothionein genes: no association with Crohn's Disease in a New Zealand population

Angharad Morgan — 2012-01-28T00:00:00Z

Metallothioneins (MTs) are excellent candidate genes for Inflammatory Bowel Disease (IBD) and have previously been shown to have altered expression in both animal and human studies of IBD. This is the first study to examine genetic variants within the MT genes and aims to determine whether such genetic variants have an important role in this disease. 28 tag SNPs in genes MT1 (subtypes A, B, E, F, G, H, M, X), MT2, MT3 and MT4 were selected for genotyping in a well-characterized New Zealand dataset consisting of 406 patients with Crohn's Disease and 638 controls. We did not find any evidence of association for MT genetic variation with CD. The lack of association indicates that genetic variants in the MT genes do not play a significant role in predisposing to CD in the New Zealand population.

Clinical predictors of inflammatory bowel disease in a genetically well-defined Caucasian population

Ziad Kanaan — 2012-01-23T00:00:00Z

Background: Crohn's disease (CD) and ulcerative colitis (UC), the two main types of inflammatory bowel disease (IBD), are multifactorial conditions of unknown etiology. The objective of this study is to examine the combined gene-environment interactions influencing IBD susceptibility in a well-defined Caucasian cohort in rural mid-America. Methods: Patients were diagnosed to have CD or UC using conventional radiologic, endoscopic, and/or histopathologic findings. Histological diagnosis was made by a single specialist gastrointestinal pathologist with a particular interest in IBD. Information regarding cigarette smoke exposure was obtained by administration of the Behavioral Risk Factor Surveillance System Survey (BRFSS) to all patients. Genomic DNA was extracted from peripheral blood leukocytes, and polymerase chain reaction (PCR) amplification and genotyping were performed for 11 Single Nucleotide Polymorphisms (SNP) in NOD2, IL23r, OCTN1 genes along with IGR. Results: Our cohort consists of 1196 patients: 435 controls, 485 CD patients, and 276 UC patients. Only patients with genotype data for at least 7 of 11 SNPs were included in our data analysis. The control groups for all 11 SNPs were in Hardy-Weinberg Equilibrium. In genotype-association SNP analysis, all NOD2 SNPs (rs5743293, rs2066844, rs2066845) and the IL23r SNP (rs11465804) showed a significant association to IBD (p < 0.03). A multiple gene-interaction analysis showed an association between NOD2 and IL23r with UC (p = 0.04). There were no associations between any OCTN1 and IGR SNPs and IBD in this cohort. A multivariable logistic regression analysis showed that female gender, "current" or "former" smoking status, family history of IBD, and NOD2 SNP minor alleles were associated with CD. Conclusion: IBD remains to be challenging to properly diagnose, characterize, and treat. Our study proposes a combined genetic, phenotypic, and environmental approach in an attempt to better understand IBD. Previously demonstrated associations between OCTN1 and IGR and IBD were not confirmed.

Influences of the G2350A Polymorphism in the ACE Gene on Cardiac Structure and Function of Ball Game Players

Yongwoo Jang — 2012-01-12T00:00:00Z

Background: Except for the I/D polymorphism in the angiotensin I-converting enzyme (ACE) gene, there were few reports about the relationship between other genetic polymorphisms in this gene and the changes in cardiac structure and function of athletes. Thus, we investigated whether the G2350A polymorphism in the ACE gene is associated with the changes in cardiac structure and function of ball game players. Total 85 healthy ball game players were recruited in this study, and they were composed of 35 controls and 50 ball game players, respectively. Cardiac structure and function were measured by 2-D echocardiography, and the G2350A polymorphism in the ACE gene analyzed by the SNaPshot method. Results: There were significant differences in left ventricular mass index (LVmassI) value among each sporting discipline studied. Especially in the athletes of basketball disciplines, indicated the highest LVmassI value than those of other sporting disciplines studied (p < 0.05). However, there were no significant association between any echocardiographic data and the G2350A polymorphism in the ACE gene in the both controls and ball game players. Conclusions: Our data suggests that the G2350A polymorphism in the ACE gene may not significantly contribute to the changes in cardiac structure and function of ball game players, although sporting disciplines of ball game players may influence the changes in LVmassI value of these athletes. Further studies using a larger sample size and other genetic markers in the ACE gene will be needed.

Genetic Polymorphisms of Nerve Growth Factor Receptor (NGFR) and the Risk of Alzheimer's Disease

Hui-Chi Cheng — 2012-01-12T00:00:00Z

Background: Loss of basal forebrain cholinergic neurons is attributable to the proapoptotic signaling induced by nerve growth factor receptor (NGFR) and may link to Alzheimer's disease (AD) risk. Only one study has investigated the association between NGFR polymorphisms and the risk of AD in an Italian population. Type 2 diabetes mellitus (DM) may modify this association based on previous animal and epidemiologic studies. Methods: This was a case-control study in a Chinese population. A total of 264 AD patients were recruited from three teaching hospitals between 2007 to 2010; 389 controls were recruited from elderly health checkup and volunteers of the hospital during the same period of time. Five common (frequency>=5%) haplotype-tagging single nucleotide polymorphisms (htSNPs) were selected from NGFR to test the association between NGFR htSNPs and the risk of AD. Results: Variant NGFR rs734194 was significantly associated with a decreased risk of AD [GG vs. TT copies: adjusted odds ratio (OR)=0.43, 95% confidence interval (CI)=0.20-0.95]. Seven common haplotypes were identified. Minor haplotype GCGCG was significantly associated with a decreased risk of AD (2 vs. 0 copies: adjusted OR=0.39, 95% CI=0.17-0.91). Type 2 DM significantly modified the association between rs2072446, rs741072, and haplotype GCTTG and GTTCG on the risk of AD among ApoE 4 non-carriers (Pinteraction<0.05). Conclusion: Inherited polymorphisms of NGFR were associated with the risk of AD; results were not significant after correction for multiple tests. This association was further modified by the status of type 2 DM.

A negative screen for mutations in calstabin 1 and 2 genes in patients with dilated cardiomyopathy.

Diogo Biagi — 2012-01-11T00:00:00Z

Background: Calstabins 1 and 2 bind to Ryanodine receptors regulating muscle excitation-contraction coupling. Mutations in Ryanodine receptors affecting their interaction with calstabins lead to different cardiac pathologies. Animal studies suggest the involvement of calstabins with dilated cardiomyopathy. Results: We tested the hypothesis that calstabins mutations may cause dilated cardiomyopathy in humans screening 186 patients with idiopathic dilated cardiomyopathy for genetic alterations in calstabins 1 and 2 genes (FKBP12 and FKBP12.6). No missense variant was found. Five no-coding variations were found but not related to the disease. Conclusions: These data corroborate other studies suggesting that mutations in FKBP12 and FKBP12.6 genes are not commonly related to cardiac diseases.

5-Azacytidine Is Insufficient For Cardiogenesis In Human Adipose-Derived Stem Cells

Wan Kamarul Zaman Wan Safwani — 2012-01-06T00:00:00Z

Background: Adipose tissue is a source of multipotent adult stem cells and it has the ability to differentiate into several types of cell lineages such as neuron cells, osteogenic cells and adipogenic cells. Several reports have shown adipose-derived stem cells (ASCs) have the ability to undergo cardiomyogenesis. Studies have shown 5-azacytidine can successfully drive stem cells such as bone marrow derived stem cells to differentiate into cardiomyogenic cells. Therefore, in this study, we investigated the effect 5-azacytidine on the cardiogenic ability of ASCs. Methods: The cardiogenic potential of ASCs was analysed by studying the morphological changes after induction, the changes in the cardiogenic genes expression i.e. GATA4, MLC-2v, MLC-2a, NKX2.5, β-MHC, α-MHC, Atrial natriuretic peptide (ANP), Connexin 43, Cardiac Troponin C, Cardiac Troponin I and myocyte enhancer factor (MEF2C) and the changes of embryonic stem cells genes expression at P5 and P10 using quantitative PCR. Results: Our results showed that the induced ASCs did not show significant morphological difference compared to the non-induced ASCs. While quantitative PCR data indicated that most cardiogenic genes and stemness genes expression level decreased after induction at P5 and P10. Conclusion: 5-azacytidine is insufficient for the cardiogenic induction of the ASCs.