101 research outputs found

    DJ-1 interacts with and regulates paraoxonase-2, an enzyme critical for neuronal survival in response to oxidative stress.

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    Loss-of-function mutations in DJ-1 (PARK7) gene account for about 1% of all familial Parkinson's disease (PD). While its physiological function(s) are not completely clear, DJ-1 protects neurons against oxidative stress in both in vitro and in vivo models of PD. The molecular mechanism(s) through which DJ-1 alleviates oxidative stress-mediated damage remains elusive. In this study, we identified Paraoxonase-2 (PON2) as an interacting target of DJ-1. PON2 activity is elevated in response to oxidative stress and DJ-1 is crucial for this response. Importantly, we showed that PON2 deficiency hypersensitizes neurons to oxidative stress induced by MPP+ (1-methyl-4-phenylpyridinium). Conversely, over-expression of PON2 protects neurons in this death paradigm. Interestingly, PON2 effectively rescues DJ-1 deficiency-mediated hypersensitivity to oxidative stress. Taken together, our data suggest a model by which DJ-1 exerts its antioxidant activities, at least partly through regulation of PON2

    Sex differences in nucleus accumbens transcriptome profiles associated with susceptibility versus resilience to subchronic variable stress

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    Depression and anxiety disorders are more prevalent in females, but the majority of research in animal models, the first step in finding new treatments, has focused predominantly on males. Here we report that exposure to subchronic variable stress (SCVS) induces depression-associated behaviors in female mice, whereas males are resilient as they do not develop these behavioral abnormalities. In concert with these different behavioral responses, transcriptional analysis of nucleus accumbens (NAc), a major brain reward region, by use of RNA sequencing (RNA-seq) revealed markedly different patterns of stress regulation of gene expression between the sexes. Among the genes displaying sex differences was DNA methyltransferase 3a (Dnmt3a), which shows a greater induction in females after SCVS. Interestingly, Dnmt3a expression levels were increased in the NAc of depressed humans, an effect seen in both males and females. Local overexpression of Dnmt3a in NAc rendered male mice more susceptible to SCVS, whereas Dnmt3a knock-out in this region rendered females more resilient, directly implicating this gene in stress responses. Associated with this enhanced resilience of female mice upon NAc knock-out of Dnmt3a was a partial shift of the NAc female transcriptome toward the male pattern after SCVS. These data indicate that males and females undergo different patterns of transcriptional regulation in response to stress and that a DNA methyltransferase in NAc contributes to sex differences in stress vulnerability

    Primary antibody deficiency in a tertiary referral hospital: A 30-year experiment

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    Background: Primary antibody deficiency (PAD) is the most common group of primary immunodeficiency disorders (PID), with a broad spectrum of clinical features ranging from severe and recurrent infections to asymptomatic disease. Objectives: The current study was performed to evaluate and compare demographic and clinical data in the most common types of PAD. Materials and Methods: We performed a retrospective review of the medical records of all PAD patients with a confirmed diagnosis of common variable immunodeficiency (CVID), hyper IgM syndrome (HIgM), selective IgA deficiency (SIgAD), and X-linked agammaglobulinemia (XLA) who were diagnosed during the last 30 years at the Children�s Medical Center, Tehran, Iran. Results: A total number of 280 cases of PAD (125 CVID, 32 HIgM, 63 SIgAD, and 60 XLA) were enrolled in the study. The median (range) age at the onset of disease in CVID, HIgM, SIgAD, and XLA was 2 (0-46), 0.91 (0-9), 1 (0-26), and 1 (0-10) years, respectively. Gastrointestinal infections were more prevalent in CVID patients, as were central nervous system infections in XLA patients. Autoimmune complications were more prevalent in HIgM patients, malignancies in CVID patients, and allergies in SIgAD patients. The mortality rate for CVID, HIgM, and XLA was 27.2, 28.1, and 25, respectively. No deaths were reported in SIgAD patients. Conclusions: SIgAD patients had the best prognosis. While all PAD patients should be monitored for infectious complications, special attention should be paid to the finding of malignancy and autoimmune disorders in CVID and HIgM patients, respectively. © 2015 Esmon Publicidad

    Primary immunodeficiency disorders in Iran: Update and new insights from the third report of the national registry

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    Background: Primary immunodeficiency disorders (PID) are a group of heterogeneous disorders mainly characterized by severe and recurrent infections and increased susceptibility to malignancies, lymphoproliferative and autoimmune conditions. National registries of PID disorders provide epidemiological data and increase the awareness of medical personnel as well as health care providers. Methods: This study presents the demographic data and clinical manifestations of Iranian PID patients who were diagnosed from March 2006 till the March of 2013 and were registered in Iranian PID Registry (IPIDR) after its second report of 2006. Results: A total number of 731 new PID patients (455 male and 276 female) from 14 medical centers were enrolled in the current study. Predominantly antibody deficiencies were the most common subcategory of PID (32.3 %) and were followed by combined immunodeficiencies (22.3 %), congenital defects of phagocyte number, function, or both (17.4 %), well-defined syndromes with immunodeficiency (17.2 %), autoinflammatory disorders (5.2 %), diseases of immune dysregulation (2.6 %), defects in innate immunity (1.6 %), and complement deficiencies (1.4 %). Severe combined immunodeficiency was the most common disorder (21.1 %). Other prevalent disorders were common variable immunodeficiency (14.9 %), hyper IgE syndrome (7.7 %), and selective IgA deficiency (7.5 %). Conclusions: Registration of Iranian PID patients increased the awareness of medical community of Iran and developed diagnostic and therapeutic techniques across more parts of the country. Further efforts must be taken by increasing the coverage of IPIDR via electronically registration and gradual referral system in order to provide better estimation of PID in Iran and reduce the number of undiagnosed cases. © 2014 Springer Science+Business Media

    Consensus Middle East and North Africa Registry on Inborn Errors of Immunity

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    Background: Inborn errors of immunity (IEIs) are a heterogeneous group of genetic defects of immunity, which cause high rates of morbidity and mortality mainly among children due to infectious and non-infectious complications. The IEI burden has been critically underestimated in countries from middle- and low-income regions and the majority of patients with IEI in these regions lack a molecular diagnosis. Methods: We analyzed the clinical, immunologic, and genetic data of IEI patients from 22 countries in the Middle East and North Africa (MENA) region. The data was collected from national registries and diverse databases such as the Asian Pacific Society for Immunodeficiencies (APSID) registry, African Society for Immunodeficiencies (ASID) registry, Jeffrey Modell Foundation (JMF) registry, J Project centers, and International Consortium on Immune Deficiency (ICID) centers. Results: We identified 17,120 patients with IEI, among which females represented 39.4%. Parental consanguinity was present in 60.5% of cases and 27.3% of the patients were from families with a confirmed previous family history of IEI. The median age of patients at the onset of disease was 36 months and the median delay in diagnosis was 41 months. The rate of registered IEI patients ranges between 0.02 and 7.58 per 100,000 population, and the lowest rates were in countries with the highest rates of disability-adjusted life years (DALY) and death rates for children. Predominantly antibody deficiencies were the most frequent IEI entities diagnosed in 41.2% of the cohort. Among 5871 patients genetically evaluated, the diagnostic yield was 83% with the majority (65.2%) having autosomal recessive defects. The mortality rate was the highest in patients with non-syndromic combined immunodeficiency (51.7%, median age: 3.5 years) and particularly in patients with mutations in specific genes associated with this phenotype (RFXANK, RAG1, and IL2RG). Conclusions: This comprehensive registry highlights the importance of a detailed investigation of IEI patients in the MENA region. The high yield of genetic diagnosis of IEI in this region has important implications for prevention, prognosis, treatment, and resource allocation

    NRF2 Activation Restores Disease Related Metabolic Deficiencies in Olfactory Neurosphere-Derived Cells from Patients with Sporadic Parkinson's Disease

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    Extent: 14p.Background: Without appropriate cellular models the etiology of idiopathic Parkinson’s disease remains unknown. We recently reported a novel patient-derived cellular model generated from biopsies of the olfactory mucosa (termed olfactory neurosphere-derived (hONS) cells) which express functional and genetic differences in a disease-specific manner. Transcriptomic analysis of Patient and Control hONS cells identified the NRF2 transcription factor signalling pathway as the most differentially expressed in Parkinson’s disease. Results: We tested the robustness of our initial findings by including additional cell lines and confirmed that hONS cells from Patients had 20% reductions in reduced glutathione levels and MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)- 2-(4-sulfophenyl)-2H-tetrazolium, inner salt] metabolism compared to cultures from healthy Control donors. We also confirmed that Patient hONS cells are in a state of oxidative stress due to higher production of H2O2 than Control cultures. siRNA-mediated ablation of NRF2 in Control donor cells decreased both total glutathione content and MTS metabolism to levels detected in cells from Parkinson’s Disease patients. Conversely, and more importantly, we showed that activation of the NRF2 pathway in Parkinson’s disease hONS cultures restored glutathione levels and MTS metabolism to Control levels. Paradoxically, transcriptomic analysis after NRF2 pathway activation revealed an increased number of differentially expressed mRNAs within the NRF2 pathway in L-SUL treated Patient-derived hONS cells compared to L-SUL treated Controls, even though their metabolism was restored to normal. We also identified differential expression of the PI3K/AKT signalling pathway, but only post-treatment. Conclusions: Our results confirmed NRF2 as a potential therapeutic target for Parkinson’s disease and provided the first demonstration that NRF2 function was inducible in Patient-derived cells from donors with uniquely varied genetic backgrounds. However, our results also demonstrated that the response of PD patient-derived cells was not co-ordinated in the same way as in Control cells. This may be an important factor when developing new therapeutics.Anthony L. Cook, Alejandra M. Vitale, Sugandha Ravishankar, Nicholas Matigian, Greg T. Sutherland, Jiangou Shan, Ratneswary Sutharsan, Chris Perry, Peter A. Silburn, George D. Mellick, Murray L. Whitelaw, Christine A. Wells, Alan Mackay-Sim and Stephen A. Woo

    Resistance to MPTP-Neurotoxicity in α-Synuclein Knockout Mice Is Complemented by Human α-Synuclein and Associated with Increased β-Synuclein and Akt Activation

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    Genetic and biochemical abnormalities of α-synuclein are associated with the pathogenesis of Parkinson's disease. In the present study we investigated the in vivo interaction of mouse and human α-synuclein with the potent parkinsonian neurotoxin, MPTP. We find that while lack of mouse α-synuclein in mice is associated with reduced vulnerability to MPTP, increased levels of human α-synuclein expression is not associated with obvious changes in the vulnerability of dopaminergic neurons to MPTP. However, expressing human α-synuclein variants (human wild type or A53T) in the α-synuclein null mice completely restores the vulnerability of nigral dopaminergic neurons to MPTP. These results indicate that human α-synuclein can functionally replace mouse α-synuclein in regard to vulnerability of dopaminergic neurons to MPTP-toxicity. Significantly, α-synuclein null mice and wild type mice were equally sensitive to neurodegeneration induced by 2′NH2-MPTP, a MPTP analog that is selective for serotoninergic and noradrenergic neurons. These results suggest that effects of α-synuclein on MPTP like compounds are selective for nigral dopaminergic neurons. Immunoblot analysis of β-synuclein and Akt levels in the mice reveals selective increases in β-synuclein and phosphorylated Akt levels in ventral midbrain, but not in other brain regions, of α-synuclein null mice, implicating the α-synuclein-level dependent regulation of β-synuclein expression in modulation of MPTP-toxicity by α-synuclein. Together these findings provide new mechanistic insights on the role α-synuclein in modulating neurodegenerative phenotypes by regulation of Akt-mediated cell survival signaling in vivo

    Mapping and Imaging the Aggressive Brain in Animals and Humans

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    Brain Health and the Batterer

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