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1.
J Fungi (Basel) ; 9(6)2023 Jun 14.
Article in English | MEDLINE | ID: mdl-37367604

ABSTRACT

Important for the infection of an insect with an entomopathogenic fungus and its use as a plant protection agent are its growth, conidiation, germination, and virulence, which all depend on the environmental temperature. We investigated not only the effect of environmental temperature but also that of production temperature of the fungus. For this purpose, Metarhizium brunneum JKI-BI-1450 was produced and incubated at different temperatures, and the factors mentioned as well as conidial size were determined. The temperature at which the fungus was produced affects its subsequent growth and conidiation on granule formulation, the speed of germination, and the conidial width, but not its final germination or virulence. The growth and conidiation was at its highest when the fungus was produced at 25 °C, whereas when the germination was faster, the warmer the fungus was produced. The incubation temperature optimum of JKI-BI-1450 in relation to growth, speed of germination, and survival time was 25-30 °C and for conidiation 20-25 °C. Conidial length decreased with increasing incubation temperature. Although the fungus could not be adapted to unfavorable conditions by the production temperature, it was found that the quality of a biological control agent based on entomopathogenic fungi can be positively influenced by its production temperature.

2.
PLoS One ; 18(3): e0283543, 2023.
Article in English | MEDLINE | ID: mdl-36972276

ABSTRACT

Insect pests introduced in eucalyptus plantations in Brazil are mostly of Australian origin, but native microorganisms have potential for their management. High quality biopesticide production based on entomopathogenic fungi depends on adequate technologies. The objective of this study was to evaluate Mycoharvester® equipment to harvest and separating particles to obtain pure Metarhizium anisopliae conidia to manage Thaumastocoris peregrinus Carpintero & Dellapé, 2006 (Hemiptera: Thaumastocoridae). The Mycoharvester® version 5b harvested and separated M. anisopliae spores. The pure conidia were suspended in Tween 80® (0.1%) and calibrated to the concentrations of 1 x 106, 107, 108 and 109 conidia/ml to evaluate the pathogenicity, lethal concentration 50 and 90 (LC50, LC90) and lethal time 50 and 90 (LT50, LT90) of this fungus to T. peregrinus. This equipment harvested 85% of the conidia from rice, with production of 4.8 ± 0.38 x 109 conidia/g dry mass of substrate + fungus. The water content of 6.36% of the single spore powder (pure conidia) separated by the Mycoharvester® was lower than that of the agglomerated product. The product harvested at the concentrations of 108 and 109 conidia/ml caused high mortality to T. peregrinus third instar nymphs and adults. The separation of conidia produced by solid-state fermentation with the Mycoharvester® is an important step toward optimizing the fungal production system of pure conidia, and to formulate biopesticides for insect pest management.


Subject(s)
Cyclonic Storms , Heteroptera , Metarhizium , Animals , Spores, Fungal , Powders , Australia , Heteroptera/microbiology , Pest Control, Biological
3.
Neurobiol Aging ; 66: 178.e1-178.e8, 2018 06.
Article in English | MEDLINE | ID: mdl-29395286

ABSTRACT

Although multiple susceptibility loci for late-onset Alzheimer's disease (LOAD) have been identified, a large portion of the genetic risk for this disease remains unexplained. LOAD risk may be associated with single-nucleotide polymorphisms responsible for changes in gene expression (eSNPs). To detect eSNPs associated with LOAD, we integrated data from LOAD genome-wide association studies and expression quantitative trait loci using Sherlock (a Bayesian statistical method). We identified a cis-regulatory eSNP (rs2927438) located on chromosome 19q13.32, for which subsequent analyses confirmed the association with both LOAD risk and the expression level of several nearby genes. Importantly, rs2927438 may represent an APOE-independent LOAD eSNP according to the weak linkage disequilibrium of rs2927438 with the 2 polymorphisms (rs7412 and rs429358) defining the APOE-ε2, -ε3, and -ε4 alleles. Furthermore, rs2927438 does not influence chromatin interaction events at the APOE locus or cis-regulation of APOE expression. Further exploratory analysis revealed that rs2927438 is significantly associated with tau levels in the cerebrospinal fluid. Our findings suggest that rs2927438 may confer APOE-independent risk for LOAD.


Subject(s)
Alzheimer Disease/etiology , Alzheimer Disease/genetics , Apolipoproteins E/genetics , Chromosomes, Human, Pair 19/genetics , Genome-Wide Association Study , Polymorphism, Single Nucleotide/genetics , tau Proteins/cerebrospinal fluid , Alleles , Alzheimer Disease/metabolism , Alzheimer Disease/pathology , Amyloid beta-Peptides/metabolism , Apolipoproteins E/metabolism , Female , Gene Expression/genetics , Genetic Predisposition to Disease/genetics , Hippocampus/metabolism , Hippocampus/pathology , Humans , Linkage Disequilibrium/genetics , Male , Organ Size , Peptide Fragments/metabolism , Quantitative Trait Loci/genetics , Risk , tau Proteins/metabolism
4.
Int J Mol Sci ; 16(1): 1312-35, 2015 Jan 07.
Article in English | MEDLINE | ID: mdl-25574603

ABSTRACT

Classical autism or autistic disorder belongs to a group of genetically heterogeneous conditions known as Autism Spectrum Disorders (ASD). Heritability is estimated as high as 90% for ASD with a recently reported compilation of 629 clinically relevant candidate and known genes. We chose to undertake a descriptive next generation whole exome sequencing case study of 30 well-characterized Caucasian females with autism (average age, 7.7 ± 2.6 years; age range, 5 to 16 years) from multiplex families. Genomic DNA was used for whole exome sequencing via paired-end next generation sequencing approach and X chromosome inactivation status. The list of putative disease causing genes was developed from primary selection criteria using machine learning-derived classification score and other predictive parameters (GERP2, PolyPhen2, and SIFT). We narrowed the variant list to 10 to 20 genes and screened for biological significance including neural development, function and known neurological disorders. Seventy-eight genes identified met selection criteria ranging from 1 to 9 filtered variants per female. Five females presented with functional variants of X-linked genes (IL1RAPL1, PIR, GABRQ, GPRASP2, SYTL4) with cadherin, protocadherin and ankyrin repeat gene families most commonly altered (e.g., CDH6, FAT2, PCDH8, CTNNA3, ANKRD11). Other genes related to neurogenesis and neuronal migration (e.g., SEMA3F, MIDN), were also identified.


Subject(s)
Autistic Disorder/genetics , Adolescent , Ankyrins/genetics , Cadherins/genetics , Child , Child, Preschool , Female , Genome, Human , High-Throughput Nucleotide Sequencing , Humans , Neurogenesis/genetics , Polymorphism, Single Nucleotide , Sequence Analysis, DNA
5.
Appl Biochem Biotechnol ; 175(5): 2357-65, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25492687

ABSTRACT

The aim of this study is to establish a quantitative determination of the vegetative insecticidal protein Vip3A from the culture supernatant of Bacillus thuringiensis either by ELISA or by the conventional quantification method of the Western blot band. The Vip3A protein was produced by fermentation of the B. thuringiensis reference strain BUPM95 in 3 L. By Western blot, the Vip3Aa16 toxin was detected in the culture supernatant during the exponential growth phase of B. thuringiensis BUPM95. However, the detection of Vip3Aa16 on Western blot showed in addition to the toxin two other strips (62 and 180 kDa) recognized by the anti-Vip3Aa16 polyclonal antibodies prepared at the Centre of Biotechnology of Sfax Tunisia. For that reason and in order to develop a technique for reliable quantification of the toxin, we have considered the production of polyclonal antibodies at the Julius Kühn Institute, Germany. These antibodies were the basis for the production of monoclonal antibodies directed against the protein produced by the Vip3Aa16 recombinant strain Escherichia coli BL21 (DE3). These monoclonal antibodies were tested by plate-trapped antigen (PTA) and triple antibody sandwich enzyme-linked immunosorbent assay (TAS-ELISA). The selection of hybridoma supernatants gave us four positive clones producing monoclonal antibodies.


Subject(s)
Antibodies, Monoclonal/analysis , Antibodies/analysis , Bacillus thuringiensis/metabolism , Bacterial Proteins/analysis , Blotting, Western/methods , Enzyme-Linked Immunosorbent Assay/methods , Escherichia coli/metabolism , Antibodies/genetics , Antibodies/metabolism , Antibodies, Monoclonal/genetics , Antibodies, Monoclonal/metabolism , Bacillus thuringiensis/chemistry , Bacillus thuringiensis/genetics , Bacillus thuringiensis/growth & development , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Escherichia coli/genetics
6.
Prep Biochem Biotechnol ; 45(5): 411-20, 2015.
Article in English | MEDLINE | ID: mdl-24839868

ABSTRACT

Seventy-eight Bacillus thuringiensis isolates were selected for a screening against the Lepidoptera species Agrotis segetum to search the higher insecticidal activity. In a preliminary bioassay, the spore-crystal mixture of 78 B. thuringiensis isolates was tested against L1 larvae of A. segetum. Fifty-two isolates had more than 60% corrected mortality after 3 days. Seven isolates caused a corrected mortality of 100% on A. segetum. Twelve isolates were selected for a second bioassay investigating the effect of the vegetative insecticidal protein (Vip) against third-instar larvae. After 7 days, the weight gain and the larval stage of each larva were recorded. This bioassay showed an aberration in larval growth increases, morphology, and weight gain. After plasmid pattern analysis, the most active strains are most likely B. thuringiensis kurstaki strains expressing the Vip3A toxin. The absence of two proteinase activities observed in the case of Cry1Ac would be the consequence of the difference in susceptibility of A. segetum to the toxins used.


Subject(s)
Bacillus thuringiensis/pathogenicity , Moths/metabolism , Moths/microbiology , Peptide Hydrolases/analysis , Animals , Bacillus thuringiensis/genetics , Bacillus thuringiensis Toxins , Bacterial Proteins/analysis , Biological Control Agents , Endotoxins/analysis , Hemolysin Proteins/analysis , Insect Proteins/analysis , Larva/microbiology , Mortality , Plasmids
7.
Per Med ; 10(8): 835-848, 2013 Nov.
Article in English | MEDLINE | ID: mdl-29776283

ABSTRACT

The era of personalized medicine is upon us and it is being fueled by large available data sets of many types that are setting the foundation for the development of more precise diagnostic tools and targeted therapies, which are improving patient outcomes. Technology innovation and concomitant price decreases in molecular scanning technologies are at the heart of this change, both accelerating at a rate that has exceeded Moore's law. This technology trend is enabling the research community to generate, and make publicly available, massive amounts of genomic data. These data come in the form not only of contextual information about the structure and function of the genome, but also in the form of variants that are correlated with human disease. Coupled with this molecular information, we are making dramatic inroads into capturing and making available high-resolution phenotypic and environmental exposure data through both incentives to physicians to migrate electronic medical records and to adoption of consumer-facing data collection and aggregation technologies. These large-scale genomic, environmental and phenotypic data together allow us to provide a multitude of new diagnostic correlations across the spectrum of possible clinical indications. To fully leverage the data foundation that will lead us to precise diagnostics and truly move the needle in outcome improvement, we need to achieve a culture shift as to how to apply this new personalized and probabilistic diagnostic information to better practice the art of medicine.

10.
Neurol Res Int ; 2012: 582075, 2012.
Article in English | MEDLINE | ID: mdl-22830016

ABSTRACT

Objectives. To determine if therapy with pioglitazone HCl and tretinoin could slow disease progression in patients with ALS. Levels of tau and pNFH in the cerebrospinal fluid were measured to see if they could serve as prognostic indicators. Methods. 27 subjects on stable doses of riluzole were enrolled. Subjects were randomized to receive pioglitazone 30 mg/d and tretinoin 10 mg/BID for six months or two matching placebos. ALSFRS-R scores were followed monthly. At baseline and at the final visit, lumbar punctures (LPs) were performed to measure cerebrospinal fluid (CSF) biomarker levels. Results. Subjects treated with tretinoin, pioglitazone, and riluzole had an average rate of decline on the ALSFRS-R scale of -1.02 points per month; subjects treated with placebo and riluzole had a rate of decline of -.86 (P = .18). Over six months of therapy, CSF tau levels decreased in subjects randomized to active treatment and increased in subjects on placebo. Further higher levels of pNF-H at baseline correlated with a faster rate of progression. Conclusion. ALS patients who were treated with tretinoin and pioglitazone demonstrated no slowing on their disease progression. Interestingly, the rate of disease progression was strongly correlated with levels of pNFH in the CSF at baseline.

11.
Recent Pat DNA Gene Seq ; 6(3): 175-9, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22827596

ABSTRACT

An extraordinary revolution in medical research has taken place over the past decade, enabled by the completion of the first human genome sequence in 2001. The Human Genome Project (HGP) has resulted in the 6 billion letter reference human genome sequence and the ultra-high throughput technologies used by medical researchers to identify correlations between positions within the human genome (genotypes) and diseases or traits (phenotypes). Just as every human disease has a genetic component, so too does every human trait. The vast majority of these diseases and traits also have an environmental component that works in conjunction with the body's hardwiring to produce the resultant phenotype- termed "complex genetic traits". A derivative of the HGP has been a deeper understanding not only of diseases but of normal human variability across the population, including aspects of athleticism. The technologies also now exist for consumers to cheaply gain access to variations in the genetic code that are correlated to traits that confer aspects of longevity, memory performance, athleticism and a multitude of others there-through gaining insight into propensities. Communication of propensity to a phenotype such as athletic performance is fraught with technical, legal (e.g., patents), social and ethical issues. That being said, the information is available, has benefit in some cases, and will be utilized in the future. Given that the "genie is out of the bottle" with respect to our ability to deliver this genetic information to individuals, over the past decade our team has worked diligently to craft the appropriate testing and communication paradigms for complex traits. Here we discuss several of the major risks and benefits of this type of testing for athletic performance. It is important to understand the limitations of genetic information in determining the vast majority of traits.


Subject(s)
Athletic Performance/physiology , Genetic Predisposition to Disease , Genetic Testing , Genome, Human , Athletes , Athletic Injuries/genetics , Genetic Variation , Genotype , Humans , Odds Ratio , Phenotype , Propensity Score , Quantitative Trait, Heritable , Risk Factors
12.
PLoS One ; 6(2): e16715, 2011 Feb 17.
Article in English | MEDLINE | ID: mdl-21379579

ABSTRACT

A causal role of mutations in multiple general transcription factors in neurodevelopmental disorders including autism suggested that alterations in global levels of gene expression regulation might also relate to disease risk in sporadic cases of autism. This premise can be tested by evaluating for changes in the overall distribution of gene expression levels. For instance, in mice, variability in hippocampal-dependent behaviors was associated with variability in the pattern of the overall distribution of gene expression levels, as assessed by variance in the distribution of gene expression levels in the hippocampus. We hypothesized that a similar change in variance might be found in children with autism. Gene expression microarrays covering greater than 47,000 unique RNA transcripts were done on RNA from peripheral blood lymphocytes (PBL) of children with autism (n = 82) and controls (n = 64). Variance in the distribution of gene expression levels from each microarray was compared between groups of children. Also tested was whether a risk factor for autism, increased paternal age, was associated with variance. A decrease in the variance in the distribution of gene expression levels in PBL was associated with the diagnosis of autism and a risk factor for autism, increased paternal age. Traditional approaches to microarray analysis of gene expression suggested a possible mechanism for decreased variance in gene expression. Gene expression pathways involved in transcriptional regulation were down-regulated in the blood of children with autism and children of older fathers. Thus, results from global and gene specific approaches to studying microarray data were complimentary and supported the hypothesis that alterations at the global level of gene expression regulation are related to autism and increased paternal age. Global regulation of transcription, thus, represents a possible point of convergence for multiple etiologies of autism and other neurodevelopmental disorders.


Subject(s)
Autistic Disorder/genetics , Gene Expression Regulation , Paternal Age , Adult , Algorithms , Autistic Disorder/blood , Autistic Disorder/etiology , Autistic Disorder/metabolism , Blood Cells/metabolism , Case-Control Studies , Child , Child, Preschool , Female , Gene Expression Profiling , Humans , Male , Microarray Analysis , Middle Aged , Risk Factors , Validation Studies as Topic , Young Adult
13.
Am J Hum Genet ; 88(2): 127-37, 2011 Feb 11.
Article in English | MEDLINE | ID: mdl-21255762

ABSTRACT

By using homozygosity mapping in a consanguineous Pakistani family, we detected linkage of nonsyndromic hearing loss to a 7.6 Mb region on chromosome 3q13.31-q21.1 within the previously reported DFNB42 locus. Subsequent candidate gene sequencing identified a homozygous nonsense mutation (c.1135G>T [p.Glu379X]) in ILDR1 as the cause of hearing impairment. By analyzing additional consanguineous families with homozygosity at this locus, we detected ILDR1 mutations in the affected individuals of 10 more families from Pakistan and Iran. The identified ILDR1 variants include missense, nonsense, frameshift, and splice-site mutations as well as a start codon mutation in the family that originally defined the DFNB42 locus. ILDR1 encodes the evolutionarily conserved immunoglobulin-like domain containing receptor 1, a putative transmembrane receptor of unknown function. In situ hybridization detected expression of Ildr1, the murine ortholog, early in development in the vestibule and in hair cells and supporting cells of the cochlea. Expression in hair cell- and supporting cell-containing neurosensory organs is conserved in the zebrafish, in which the ildr1 ortholog is prominently expressed in the developing ear and neuromasts of the lateral line. These data identify loss-of-function mutations of ILDR1, a gene with a conserved expression pattern pointing to a conserved function in hearing in vertebrates, as underlying nonsyndromic prelingual sensorineural hearing impairment.


Subject(s)
Codon, Nonsense/genetics , Genes, Recessive/genetics , Genetic Predisposition to Disease , Hearing Loss/genetics , Receptors, Cell Surface/genetics , Animals , Chromosome Mapping , Chromosomes, Human, Pair 3/genetics , Consanguinity , Ear, Inner , Female , Genetic Linkage , Genotype , Humans , In Situ Hybridization , Lod Score , Male , Mice , Pedigree , Zebrafish
14.
Neurobiol Aging ; 32(3): 550.e1-4, 2011 Mar.
Article in English | MEDLINE | ID: mdl-20138404

ABSTRACT

Mutations in the FUS gene have recently been described as a cause of familial amyotrophic lateral sclerosis (ALS), but their role in the pathogenesis of sporadic ALS is unclear. We undertook mutational screening of all coding exons of FUS in 228 sporadic ALS cases, and, as previous reports suggest that exon 15 represents a mutational hotspot, we sequenced this exon in an additional 1295 sporadic cases. Six variants in six different cases were found, indicating that FUS mutations can underlie apparently sporadic ALS, but account for less than 1% of this form of disease.


Subject(s)
Amyotrophic Lateral Sclerosis/genetics , Mutation/genetics , RNA-Binding Protein FUS/genetics , Adolescent , Adult , Aged , Aged, 80 and over , Child , DNA Mutational Analysis/methods , Exons/genetics , Female , Genotype , Humans , Italy , Male , Middle Aged , United States , Young Adult
15.
Laryngoscope ; 120(12): 2489-93, 2010 Dec.
Article in English | MEDLINE | ID: mdl-21046548

ABSTRACT

OBJECTIVES/HYPOTHESIS: To determine the cause of autosomal dominant hearing loss segregating in an American family. STUDY DESIGN: Family study. METHODS: Otologic and audiometric examination was performed on affected family members. Genome wide parametric multipoint linkage mapping using a dominant model was performed with Affymetrix 50K GeneChip data. Direct sequencing was used to confirm the causative mutation. RESULTS: In American family 467, segregating autosomal dominant nonsyndromic hearing loss, a novel heterozygous missense mutation (c.362T>C; p.F121S) was identified in the COCH gene. This mutation was also associated with vestibular dysfunction typical of other DFNA9 families. However, affected family members also exhibited memory loss and night blindness. CONCLUSIONS: The novel COCH mutation affects the functionally important limulus factor C, Coch-5b2 and Lgl1 domain where most DFNA9 mutations have been localized. The onset of the hearing loss, in the 2nd or 3rd decade of life, is earlier than in most DFNA9 families. The progression of hearing loss and vestibular dysfunction in the American family is typical of other DFNA9 families with mutations in this domain. Memory loss and night blindness have not been previously reported in DFNA9 families.


Subject(s)
DNA/genetics , Genetic Association Studies/methods , Genetic Predisposition to Disease , Hearing Loss, Sensorineural/genetics , Mutation, Missense , Proteins/genetics , Audiometry , Disease Progression , Extracellular Matrix Proteins , Family , Female , Hearing Loss, Sensorineural/diagnosis , Hearing Loss, Sensorineural/physiopathology , Humans , Male , Pedigree , Polymerase Chain Reaction , Polymorphism, Single Nucleotide , United States
16.
Biomaterials ; 31(34): 8882-8, 2010 Dec.
Article in English | MEDLINE | ID: mdl-20832112

ABSTRACT

Human cells in vivo are exposed to a topographically rich, 3-dimenisional environment which provides extracellular cues initiating a cascade of biochemical signals resulting in changes in cell behavior. One primary focus of our group is the development of biomimetic substrates with anisotropic nanoscale topography to elucidate the mechanisms by which physical surface cues are translated into biochemical signals. To investigate changes in gene expression as a result of nanotopographic cues, Human Umbilical Vein Endothelial Cells (HUVECs) were cultured on chemically identical flat and 400 nm pitch nanogrooved surfaces. After 12 h, RNA was harvested for an Affymetrix HG U133 Plus 2.0 gene array. Of over 47,000 possible gene probes, 3171 had at least a two-fold difference in expression between the control flat and 400 nm pitch. The gene ontology groups with the most significant increase in expression are involved in protein modification and maintenance, similar to cells upregulating chaperone and protein synthesis genes in response to physical stresses. The most significant decreases in expression were observed with cell cycle proteins, including cyclins and checkpoint proteins. Extracellular matrix proteins, including integrins, collagens, and laminins, are almost uniformly downregulated on the 400 nm pitch surfaces compared to control. The downregulation of one of these genes, integrin beta 1, was confirmed via quantitative PCR. Together, these gene array data, in addition to our studies of cell behavior on nanoscale surfaces, contribute to our understanding of the signaling pathways modulated by topographical surface cues.


Subject(s)
Endothelial Cells/metabolism , Gene Expression Regulation , Nanostructures/chemistry , Cell Cycle/genetics , Cell Proliferation , Cyclin-Dependent Kinases/genetics , Cyclin-Dependent Kinases/metabolism , Cyclins/genetics , Cyclins/metabolism , Down-Regulation/genetics , Extracellular Matrix Proteins/genetics , Extracellular Matrix Proteins/metabolism , Humans , Integrins/genetics , Integrins/metabolism , Particle Size , Umbilical Veins/cytology , Up-Regulation/genetics
17.
Proc Natl Acad Sci U S A ; 107(18): 8404-9, 2010 May 04.
Article in English | MEDLINE | ID: mdl-20404173

ABSTRACT

A recently identified variant within the fat mass and obesity-associated (FTO) gene is carried by 46% of Western Europeans and is associated with an approximately 1.2 kg higher weight, on average, in adults and an approximately 1 cm greater waist circumference. With >1 billion overweight and 300 million obese persons worldwide, it is crucial to understand the implications of carrying this very common allele for the health of our aging population. FTO is highly expressed in the brain and elevated body mass index (BMI) is associated with brain atrophy, but it is unknown how the obesity-associated risk allele affects human brain structure. We therefore generated 3D maps of regional brain volume differences in 206 healthy elderly subjects scanned with MRI and genotyped as part of the Alzheimer's Disease Neuroimaging Initiative. We found a pattern of systematic brain volume deficits in carriers of the obesity-associated risk allele versus noncarriers. Relative to structure volumes in the mean template, FTO risk allele carriers versus noncarriers had an average brain volume difference of approximately 8% in the frontal lobes and 12% in the occipital lobes-these regions also showed significant volume deficits in subjects with higher BMI. These brain differences were not attributable to differences in cholesterol levels, hypertension, or the volume of white matter hyperintensities; which were not detectably higher in FTO risk allele carriers versus noncarriers. These brain maps reveal that a commonly carried susceptibility allele for obesity is associated with structural brain atrophy, with implications for the health of the elderly.


Subject(s)
Alleles , Brain/anatomy & histology , Obesity/genetics , Proteins/genetics , Aged , Alpha-Ketoglutarate-Dependent Dioxygenase FTO , Brain/metabolism , Genetic Predisposition to Disease , Humans , Imaging, Three-Dimensional , Magnetic Resonance Imaging , Organ Size , Risk Factors
18.
Neuroimage ; 51(2): 542-54, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20197096

ABSTRACT

In a genome-wide association study of structural brain degeneration, we mapped the 3D profile of temporal lobe volume differences in 742 brain MRI scans of Alzheimer's disease patients, mildly impaired, and healthy elderly subjects. After searching 546,314 genomic markers, 2 single nucleotide polymorphisms (SNPs) were associated with bilateral temporal lobe volume (P<5 x 10(-7)). One SNP, rs10845840, is located in the GRIN2B gene which encodes the N-methyl-d-aspartate (NMDA) glutamate receptor NR2B subunit. This protein - involved in learning and memory, and excitotoxic cell death - has age-dependent prevalence in the synapse and is already a therapeutic target in Alzheimer's disease. Risk alleles for lower temporal lobe volume at this SNP were significantly over-represented in AD and MCI subjects vs. controls (odds ratio=1.273; P=0.039) and were associated with mini-mental state exam scores (MMSE; t=-2.114; P=0.035) demonstrating a negative effect on global cognitive function. Voxelwise maps of genetic association of this SNP with regional brain volumes, revealed intense temporal lobe effects (FDR correction at q=0.05; critical P=0.0257). This study uses large-scale brain mapping for gene discovery with implications for Alzheimer's disease.


Subject(s)
Alzheimer Disease/genetics , Nerve Degeneration/genetics , Receptors, N-Methyl-D-Aspartate/genetics , Temporal Lobe/pathology , Aged , Alzheimer Disease/pathology , Genome-Wide Association Study , Genotype , Humans , Image Interpretation, Computer-Assisted , Magnetic Resonance Imaging , Nerve Degeneration/pathology , Polymorphism, Single Nucleotide
19.
BMC Genomics ; 11: 25, 2010 Jan 12.
Article in English | MEDLINE | ID: mdl-20067632

ABSTRACT

BACKGROUND: Neurofibrillary tangles (NFT), a cardinal neuropathological feature of Alzheimer's disease (AD) that is highly correlated with synaptic loss and dementia severity, appear to be partly attributable to increased phosphorylation of the microtubule stabilizing protein tau at certain AD-related residues. Identifying the kinases involved in the pathologic phosphorylation of tau may provide targets at which to aim new AD-modifying treatments. RESULTS: We report results from a screen of 572 kinases in the human genome for effects on tau hyperphosphorylation using a loss of function, high-throughput RNAi approach. We confirm effects of three kinases from this screen, the eukaryotic translation initiation factor 2 alpha kinase 2 (EIF2AK2), the dual-specificity tyrosine-(Y)-phosphorylation regulated kinase 1A (DYRK1A), and the A-kinase anchor protein 13 (AKAP13) on tau phosphorylation at the 12E8 epitope (serine 262/serine 356). We provide evidence that EIF2AK2 effects may result from effects on tau protein expression, whereas DYRK1A and AKAP13 are likely more specifically involved in tau phosphorylation pathways. CONCLUSIONS: These findings identify novel kinases that phosphorylate tau protein and provide a valuable reference data set describing the kinases involved in phosphorylating tau at an AD-relevant epitope.


Subject(s)
Alzheimer Disease/enzymology , Protein Kinases/analysis , RNA, Small Interfering/analysis , tau Proteins/metabolism , Alzheimer Disease/genetics , Cell Line, Tumor , Gene Expression Profiling , Genetic Testing , Genome, Human , Humans , Phosphorylation , Protein Kinases/genetics , RNA, Small Interfering/genetics , Up-Regulation
20.
Eur J Hum Genet ; 18(6): 685-93, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20068591

ABSTRACT

This study aimed at contributing to the elucidation of the genetic basis of age-related hearing impairment (ARHI), a common multifactorial disease with an important genetic contribution as demonstrated by heritability studies. We conducted a genome-wide association study (GWAS) in the Finnish Saami, a small, ancient, genetically isolated population without evidence of demographic expansion. The choice of this study population was motivated by its anticipated higher extent of LD, potentially offering a substantial power advantage for association mapping. DNA samples and audiometric measurements were collected from 352 Finnish Saami individuals, aged between 50 and 75 years. To reduce the burden of multiple testing, we applied principal component (PC) analysis to the multivariate audiometric phenotype. The first three PCs captured 80% of the variation in hearing thresholds, while maintaining biologically important audiometric features. All subjects were genotyped with the Affymetrix 100 K chip. To account for multiple levels of relatedness among subjects, as well as for population stratification, association testing was performed using a mixed model. We summarised the top-ranking association signals for the three traits under study. The top-ranked SNP, rs457717 (P-value 3.55 x 10(-7)), was associated with PC3 and was localised in an intron of the IQ motif-containing GTPase-activating-like protein (IQGAP2). Intriguingly, the SNP rs161927 (P-value 0.000149), seventh-ranked for PC1, was positioned immediately downstream from the metabotropic glutamate receptor-7 gene (GRM7). As a previous GWAS of a European and Finnish sample set already suggested a role for GRM7 in ARHI, this study provides further evidence for the involvement of this gene.


Subject(s)
Hearing Loss/genetics , Age Factors , Aged , Aged, 80 and over , Aging/genetics , Aging/physiology , Female , Finland/epidemiology , Gene Frequency , Genome-Wide Association Study , Hearing Loss/epidemiology , Humans , Male , Middle Aged , Polymorphism, Single Nucleotide , Receptors, Metabotropic Glutamate/genetics , Receptors, Metabotropic Glutamate/physiology , Scandinavian and Nordic Countries/ethnology , Validation Studies as Topic , ras GTPase-Activating Proteins/genetics , ras GTPase-Activating Proteins/physiology
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