Effect of BDNF Val66Met on Memory Decline and Hippocampal Atrophy in Prodromal Alzheimer’s Disease: A Preliminary Study

Objective

Cross-sectional genetic association studies have reported equivocal results on the relationship between the brain-derived neurotrophic factor (BDNF) Val66Met and risk of Alzheimer’s disease (AD). As AD is a neurodegenerative disease, genetic influences may become clearer from prospective study. We aimed to determine whether BDNF Val66Met polymorphism influences changes in memory performance, hippocampal volume, and Aβ accumulation in adults with amnestic mild cognitive impairment (aMCI) and high Aβ.

Methods

Thirty-four adults with aMCI were recruited from the Australian, Imaging, Biomarkers and Lifestyle (AIBL) Study. Participants underwent PiB-PET and structural MRI neuroimaging, neuropsychological assessments and BDNF genotyping at baseline, 18 month, and 36 month assessments.

Results

In individuals with aMCI and high Aβ, Met carriers showed significant and large decline in episodic memory (d = 0.90, p = .020) and hippocampal volume (d = 0.98, p = .035). BDNF Val66Met was unrelated to the rate of Aβ accumulation (d = −0.35, p = .401).

Conclusions

Although preliminary due to the small sample size, results of this study suggest that high Aβ levels and Met carriage may be useful prognostic markers of accelerated decline in episodic memory, and reductions in hippocampal volume in individuals in the prodromal or MCI stage of AD.     

Association between circulating irisin levels and epicardial fat in patients with treatment-naïve overt hyperthyroidism

Abstract

Background: Hyperthyroidism is associated with increased metabolic activity and thermogenesis. Irisin is a key molecule in thermogenesis and energy expenditure via adipose tissue browning. Epicardial fat was previously defined as brown-like fat. Thus, here we aimed to evaluate the association between serum irisin level and epicardial fat thickness (EFT) in patients with hyperthyroidism.

Methods: A total of 25 hyperthyroid patients and 24 age-, sex- and BMI-matched healthy controls were enrolled. Serum irisin levels, thyroid hormone levels, and body compositions were compared. EFT was measured via transthoracic echocardiography.

Results: Serum irisin level and EFT were significantly higher in the hyperthyroid group (p?<?0.001 and p?=?0.001, respectively). The distributions of fat-free mass, muscle mass and fat mass were similar between the study groups. Serum irisin level was negatively correlated with TSH (p?<?0.001) and positively correlated with fT3 (p?<?0.001), fT4 (p?<?0.001) and TSH receptor antibody (p?=?0.002) levels and EFT (p?=?0.001). In multivariate linear regression analysis, TSH (β?=??0.475, p?<?0.001) and EFT (β?=?0.290, p?=?0.023) levels were significantly associated with serum irisin levels.

Conclusions: An increased serum irisin level associated with EFT might contribute to metabolic derangement in hyperthyroidism. Further studies are needed to elucidate whether irisin levels and EFT are affected by hyperthyroidism or vice versa.     

BDNF Val66Met and cognition: all,none, or some? A meta‐analysis of the genetic association

The Val66Met, G196A (rs6265) polymorphism in the brain-derived neurotrophic factor gene, BDNF, located at 11p13, has been associated with a wide range of cognitive functions. Yet, the pattern of results is complex and conflicting. In this study, we conducted a meta-analysis that included 23 publications containing 31 independent samples comprised of 7095 individuals. The phenotypes that were examined in this analysis covered a wide variety of cognitive functions and included indicators of general cognitive ability, memory, executive function, visual processing skills and cognitive fluency. The meta-analysis did not establish significant genetic associations between the Val66Met polymorphism and any of the phenotypes that were included.     

Metabolomic analysis of biochemical changes in the plasma and urine of first-episode neuroleptic-naïve schizophrenia patients after treatment with risperidone

Early findings propose that impaired neurotransmission in the brain plays a key role in the pathophysiology of schizophrenia. Recent advances in understanding its multiple etiologies and pathogenetic mechanisms provide more speculative hypotheses focused on even broader somatic systems. Using a targeted tandem mass spectrometry (MS/MS)-based metabolomic platform, we compared metabolic signatures consisting of monoamine and amino acid neurotransmitter (NT) metabolites in plasma/urine simultaneously between first-episode neuroleptic-na?ve schizophrenia patients (FENNS) and healthy controls before and after a 6-week risperidone monotherapy, which suggest that the patient NT profiles are restoring during treatment. To detect and identify potential biomarkers associated with schizophrenia and risperidone treatment, we also performed a combined ultraperformance liquid chromatography-mass spectrometry (UPLC-MS) and (1)H nuclear magnetic resonance (NMR)-based metabolomic profiling of the same samples, indicating a further deviation of the patients' global metabolic profile from that of controls. The NTs and their metabolites together with the 32 identified biomarkers underpin that metabolic pathways including NT metabolism, amino acid metabolism, glucose metabolism, lipid metabolism, energy metabolism, antioxidant defense system, bowel microflora and endocrine system are disturbed in FENNS. Among them, pregnanediol, citrate and α-ketoglutarate (α-KG) were significantly associated with symptomatology of schizophrenia after Bonferroni correction and may be useful biomarkers for monitoring therapeutic efficacy. These findings promise to yield valuable insights into the pathophysiology of schizophrenia and may advance the approach to treatment, diagnosis and disease prevention of schizophrenia and related syndromes.     

Genetic polymorphisms of Fas (CD95) and Fas ligand (CD178) influence the rise in CD4+ T cell count after antiretroviral therapy in drug-naïve HIV-positive patients

Fas and Fas ligand (FasL) are the main genes that control cell death in the immune system. Indeed, they are crucial for the regulation of T lymphocyte homeostasis because they can influence cell proliferation. A strong debate exists on the importance of Fas/FasL system during HIV infection, which is characterized by the loss of CD4+ T cells directly, or indirectly, caused by the virus. To investigate whether the genetic background of the host plays a role in the immunoreconstitution, we studied the influence of different Fas and FasL polymorphisms on CD4+ T lymphocyte count and plasma viral load following initiation of highly active antiretroviral therapy (HAART) in drug-naïve HIV+ patients. We studied 131 individuals, who were compared to 136 healthy donors. Statistical analysis was performed by using X ² test, Fischer's Exact Test, and analysis for repeated measurements. The group of HIV+ patients had an unexpected lower frequency of FasLnt169 polymorphism (delT allele) than healthy controls (p=0.039). We then observed no significant differences in the immune reconstitution, in terms of CD4+ T cell increase, when the influence of single alleles of the gene Fas or FasL was considered. However, the combination of some polymorphisms of Fas or FasL significantly influenced CD4+ T cell production and viral load decrease, showing that these genes can play a role in the immunoreconstitution triggered by antiretroviral therapy.     

Remote monitoring of pulmonary artery pressures with CardioMEMS in patients with chronic heart failure and NYHA class III: first experiences in the Netherlands

We report the first patient experiences with the CardioMEMS device in the Erasmus MC Thorax Center in the Netherlands. In line with clinical trial evidence, the device is applicable in patients with chronic heart failure in functional New York Heart Association class III with at least 1 admission for heart failure in the past 12 months. CardioMEMS has been shown to be safe and reliable, and effective in reducing the number of hospitalisations for heart failure by guided therapy based on pulmonary artery pressures.     

17β-Estradiol and steady-state concentrations of H2O2: antiapoptotic effect in endometrial cells from patients with endometriosis

Increased levels of hydrogen peroxide (H₂O₂) can initiate protective responses to limit or repair oxidative damage. However, H₂O₂ signals also fine-tune responses to growth factors and cytokines controlling cell division, differentiation, and proliferation. Because 17β-estradiol (E₂) also plays important roles in these processes, and is considered a major risk factor in the development and progression of endometriosis, this study evaluated whether E₂ has an antiapoptotic effect on oxidative stress in endometrial cells in combination with steady-state H₂O₂ levels ([H₂O₂]ss). Endometrial stromal cells were prepared from the eutopic endometrium of 18 women with and without endometriosis to produce primary cells. These cells were stimulated with E₂ for 20 h, exposed to [H₂O₂]ss, and examined for cell viability, proliferation, and apoptosis. The endometrial cells from women with endometriosis maintained the steady state for 120 min at high H₂O₂ concentrations. When they were pretreated with E₂ and exposed to [H₂O₂]ss, a decrease in apoptosis level was observed compared to the control cells (p<0.01). The endometrial cells from patients with endometriosis subjected to both E₂ and [H₂O₂]ss showed increased ERK phosphorylation. These findings suggested that H₂O₂ is a signaling molecule that downregulates apoptosis in endometrial cells, supporting the fact that endometriosis, albeit a benign disease, shares some features with cancer such as decreased catalase levels. These results link the E₂ effects on [H₂O₂]ss to resistance to apoptosis and progression of endometriosis.     

Lack of correlation between seminal and plasma HIV-1 viral loads is associated with CD4 T cell depletion in therapy-naïve HIV-1+ patients

The present study was conducted to investigate a possible correlation between plasma (PVL) and seminal viral load (SVL) on treatment-na?ve HIV-1-infected patients in Vitória, ES, Brazil. We also evaluated whether the progressive immunosuppression associated with HIV disease (as evidenced by declining CD4 T cell counts) has any impact on the correlation between PVL and SVL HIV-1. Viral load on paired blood and semen samples from 56 consecutive treatment-na?ve patients were evaluated and compared to CD4 cell counts. Viral load and T cell counts (cells/microl) were determined by NASBA and by flow cytometry, respectively. Overall, a strong positive correlation between PVL and SVL (rho = 0.438, p = 0.001) was observed. However, when patients were grouped according to their CD4 counts, this correlation was only significant among patients with CD4 counts > 200 cells/microl. Results presented here demonstrate the existence of a strong correlation between PVL and SVL on patients with CD4 cell counts > 200 cells/microl, suggesting that this association may correlate with disease progression.     

Simultaneous identification of GSTP1 Ile105→Val105 and Ala114→Val114 substitutions using an amplification refractory mutation systempolymerase chain reactionassay: studies in patients with asthma

Background  

The glutathione S-transferase (GST) enzyme GSTP1 utilizes byproducts of oxidative stress. We previously showed that alleles of GSTP1 that encode the Ile105→Val105 substitution are associated with the asthma phenotypes of atopy and bronchial hyperresponsiveness (BHR). However, a further polymorphic site (Ala114→Val114) has been identified that results in the following alleles: GSTP1 ^* A (wild-type Ile105→Ala114), GSTP1 ^* B (Val105→Ala114), GSTP1 ^* C (Val105→Val114) and GSTP1 ^* D (Ile105→Val114).     

Association of TNF-α polymorphism rs1800629 with multisomatoform disorder in a group of German patients and healthy controls: An explorative study

IntroductionThe etiology of multisomatoform disorder (MSD) is still largely unknown, but genetic factors seem to have an influence on pathogenesis. Pain is a major symptom of MSD and polymorphisms of different proinflammatory cytokines have been found associated with pain in former studies. Therefore, we presumed that cytokine polymorphisms could also be associated with MSD.Patients and methodsGroups of 148 MSD patients with pain as the leading clinical symptom and 149 age and gender matched healthy controls participated in this study. Nine cytokine polymorphisms were genotyped and statistically analyzed for associations with MSD.ResultsAllelic and genotypic associations were found for rs16944 (interleukin 1β), rs1800629 (tumor necrosis factor) and rs909253 (lymphotoxin α). After correcting for multiple testing, the association of rs1800629 with MSD remained significant. The rare A-allele was correlated with MSD (p = 0.007).DiscussionSince the common G-allele of rs1800629 (TNFα) occurs much more often in the control group than in the MSD group it is assumed to be protective. Being carrier of the A-allele seems to be a risk factor for MSD.     

The MTRR 66A>G polymorphism and maternal risk of birth of a child with Down syndrome in Caucasian women: a case–control study and a meta-analysis

We performed a large case–control study and a meta-analysis of the literature to address the role of the methionine synthase reductase (MTRR) c.66A>G polymorphism as a maternal risk factor for the birth of a child with Down Syndrome (DS) among Caucasian women. A total of 253 mothers of a DS child (MDS) and 298 control mothers of Italian origin were included in the case–control study. The meta-analysis of previous and present data involved a total of seven studies performed in Caucasian populations (971 MDS and 1,387 control mothers). Results from the meta-analysis indicated overall a positive significant association between MTRR c.66A>G genotype [OR 1.36 (95 % CI 1.10–1.68), dominant model] and allele frequencies [OR 1.26 (95 % CI 1.04–1.51), allele contrast model] and maternal risk of birth of a child with DS. A sensitivity analysis revealed some interesting differences between Europeans, Caucasians of European descent, and inhabitants of Mediterranean regions, suggesting the possibility of population-specific modifying factors. The case–control study revealed association of the polymorphism with increased folate levels, and a possible interaction with the methionine synthase (MTR) c.2756A>G one, that resulted in a borderline significant maternal risk of birth of a child with DS for the double heterozygous MTR 2756AG/MTRR 66AG genotype [OR 1.79 (95 % CI 1.00–3.18)]. Overall, present data suggest that the MTRR c.66A>G polymorphism represents a risk factor for the birth of a child with DS among white Caucasian women. However, the combined presence of other genetic factors and interactions with geographic and environmental ones, can modify the effect of the single polymorphism alone, leading to population specific effect sizes.     

Serum concentrations of fibroblast growth factor 19 in patients with obesity and type 2 diabetes mellitus: the influence of acute hyperinsulinemia, very-low calorie diet and PPAR-α agonist treatment

The aim of our study was to measure serum concentrations of fibroblast growth factor 19 (FGF-19) in patients with obesity (OB), obesity and type 2 diabetes mellitus (T2DM) and healthy subjects (C) at baseline and after selected interventions. We measured serum FGF-19 levels and other biochemical and hormonal parameters in 29 OB and 19 T2DM females and 30 sex- and age-matched control subjects. The interventions were acute hyperinsulinemia during isoglycemic-hyperinsulinemic clamp (n=11 for T2DM and 10 for C), very-low calorie diet (VLCD, n=12 for OB) and 3 months treatment with PPAR-alpha agonist fenofibrate (n=11 for T2DM). Baseline serum FGF-19 levels were significantly lower in OB relative to C group (132.1+/-12.7 vs. 202.2+/-16.7 pg/ml, p<0.05), while no significant difference was observed between T2DM and OB or control group. Acute hyperinsulinemia tended to decrease FGF-19 levels in both healthy and T2DM subjects. Three weeks of VLCD in OB group had no significant effect on FGF-19, whereas three months of fenofibrate treatment markedly reduced FGF-19 levels in T2DM patients (194.58+/-26.2 vs. 107.47+/-25.0 pg/ml, p<0.05). We conclude that FGF-19 levels in our study were at least partially dependent upon nutritional status, but were not related to parameters of glucose metabolism or insulin sensitivity.