Coexistence of CMT-2D and distal SMA-V phenotypes in an Italian family with a GARS gene mutation.

An Italian multigenerational family with four members affected by an axonal Charcot-Marie-Tooth type 2D (CMT-2D) or distal spinal muscular atrophy (dSMA) phenotype with upper limb predominance, variable age at onset, degree of disability, and autosomal dominant inheritance is reported. A novel heterozygous missense GARS gene mutation (D500N) was identified.

VEGF gene variability and type 1 diabetes: evidence for a protective role.

Vascular endothelial growth factor (VEGF) is a multifunctional cytokine originally described as an angiogenic factor. A number of reports have recently demonstrated that VEGF increases pancreatic islet survival after islet transplantation by stimulating angiogenesis and improving islet revascularization. Whether VEGF can protect from the autoimmune destruction of insulin-producing beta-cells that characterizes the development of type 1 diabetes is presently unknown.

Transplanted ALDHhiSSClo neural stem cells generate motor neurons and delay disease progression of nmd mice, an animal model of SMARD1.

Spinal muscular atrophy with respiratory distress type 1 (SMARD1) is an infantile autosomal-recessive motor neuron disease caused by mutations in the immunoglobulin micro-binding protein 2. We investigated the potential of a spinal cord neural stem cell population isolated on the basis of aldehyde dehydrogenase (ALDH) activity to modify disease progression of nmd mice, an animal model of SMARD1. ALDH(hi)SSC(lo) stem cells are self-renewing and multipotent and when intrathecally transplanted in nmd mice generate motor neurons properly localized in the spinal cord ventral horns.

Identification of a primitive brain-derived neural stem cell population based on aldehyde dehydrogenase activity.

Stem cells are undifferentiated cells defined by their ability to self-renew and differentiate to progenitors and terminally differentiated cells. Stem cells have been isolated from almost all tissues, and an emerging idea is that they share common characteristics such as the presence of ATP-binding cassette transporter G2 and high telomerase and aldehyde dehydrogenase (ALDH) activity, raising the hypothesis of a set of universal stem cell markers. In the present study, we describe the isolation of primitive neural stem cells (NSCs) from adult and embryonic murine neurospheres and dissociated tissue, based on the expression of high levels of ALDH activity.

Multipotentiality, homing properties, and pyramidal neurogenesis of CNS-derived LeX(ssea-1)+/CXCR4+ stem cells.

Achieving efficient distribution of neural stem cells throughout the central nervous system (CNS) and robust generation of specific neurons is a major challenge for the development of cell-mediated therapy for neurodegenerative diseases. We isolated a primitive neural stem cell subset, double positive for LeX(Le) and CXCR4(CX) antigens that possesses CNS homing potential and extensive neuronal repopulating capacity. Le+CX+ cells are multipotential and can generate neurons as well as myogenic and endothelial cells.

Is M129V of PRNP gene associated with Alzheimer's disease? A case-control study and a meta-analysis.

The methionine/valine (M/V) polymorphism at codon 129 within the prion protein gene (PRNP) represents a known risk factor for Creutzfeldt-Jakob disease (CJD). Few authors reported also the effects of this polymorphism on the risk of Alzheimer's disease (AD), although with controversial results. To better clarify this issue, we performed a novel case-control study and a meta-analysis of published association studies between PRNP and AD.

Polyneuropathy in POEMS syndrome: role of angiogenic factors in the pathogenesis.

In order to clarify the role of angiogenic factors in polyneuropathy of POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, skin changes) syndrome, we measured the serum concentrations of vascular endothelial growth factor (VEGF) and erythropoietin (EPO) in 11 patients and correlated these with VEGF and EPO peripheral nerve expression and the degree of endoneurial vessel involvement. We found that POEMS syndrome was associated with high levels of serum VEGF and, conversely, low levels of serum EPO. Similarly, in POEMS nerves VEGF was highly expressed in blood vessels and some non-myelin-forming Schwann cells.

Vascular endothelial growth factor gene variability is associated with increased risk for AD.

Converging evidence points to a pivotal role of vascular endothelial growth factor (VEGF) in neuronal protection and a lack of its activity in neurodegenerative disorders. To investigate this possible association, we screened the VEGF gene promoter for various well-known single-nucleotide polymorphisms in a series of 249 consecutively recruited Italian patients with sporadic Alzheimer's disease (AD). Genetic analysis indicated different distributions of two single-nucleotide polymorphisms in the AD population compared with healthy control subjects.

Skeletal muscle gene expression profiling in mitochondrial disorders.

Extremely variable clinic and genetic features characterize mitochondrial encephalomyopathy (MEM). Pathogenic mitochondrial DNA (mtDNA) defects can be divided into large-scale rearrangements and single point mutations. Clinical manifestations become evident when a threshold percentage of the total mtDNA is mutated.

Influence of the Glu298Asp polymorphism of NOS3 on age at onset and homocysteine levels in AD patients.

The distribution of the Glu298Asp polymorphism in NOS3 gene was determined in 405 Italian patients with "probable" Alzheimer's disease (AD) compared with 253 age-matched controls. Total plasma homocysteine (tHcy) levels were evaluated in 97 patients and 23 controls, and were correlated with the Glu298Asp genotype. A significantly increased frequency of the Glu/Glu genotype in late onset AD (LOAD) patients was found.

Wild-type bone marrow cells ameliorate the phenotype of SOD1-G93A ALS mice and contribute to CNS, heart and skeletal muscle tissues.

Amyotrophic lateral sclerosis (ALS) is a progressive, lethal neurodegenerative disease without any effective therapy. To evaluate the potential of wild-type bone marrow (BM)-derived stem cells to modify the ALS phenotype, we generated BM chimeric Cu/Zn superoxide dismutase (SOD1) mice by transplantation of BM cells derived from mice expressing green fluorescent protein (GFP) in all tissues and from Thy1-YFP mice that express a spectral variant of GFP (yellow fluorescent protein) in neurons only. In the recipient cerebral cortex, we observed rare GFP+ and YFP+ neurons, which were probably generated by cell fusion, as demonstrated by fluorescence in situ hybridization (FISH) analysis, suggesting that this phenomenon is not limited to Purkinje cells.

Skeletal muscle differentiation potential of human adult bone marrow cells.

Murine bone marrow (BM) cells have been shown to undergo myogenic differentiation and participate in muscle repair in different muscle regeneration models. In the present paper, we report on a subset of cells (CD45+/desmin+) with myogenic potential being present at very low frequencies in human adult BM. By a simple culture method, we were able to obtain in vitro multinucleated myotubes in up to 20% of the cultures.

Neuronal differentiation of murine bone marrow Thy-1- and Sca-1-positive cells.

Recent evidence suggests that cells from bone marrow can acquire neuroectodermal phenotypes in cell culture or after transplantation in animal models and in the human brain. However, isolation of the bone marrow cell subpopulation with neuronal differentiation potential remains a challenge. To isolate and expand neural progenitors from whole murine bone marrow, bone marrow was obtained from hind limb bone of C57BL6 mice and plated in culture with neuronal medium with basic fibroblast growth factor and epidermal growth factor.

A library of siRNA duplexes targeting the phosphoinositide 3-kinase pathway: determinants of gene silencing for use in cell-based screens.

Gene silencing through RNA interference (RNAi) has been established as a means of conducting reverse genetic studies. In order to better understand the determinants of short interfering RNA (siRNA) knockdown for use in high-throughput cell-based screens, 148 siRNA duplexes targeting 30 genes within the PI3K pathway were selected and synthesized. The extent of RNA knockdown was measured for 22 genes by quantitative real-time PCR.

POLG mutations in sporadic mitochondrial disorders with multiple mtDNA deletions.

The accumulation of multiple mitochondrial DNA (mtDNA) deletions in stable tissues is a distinctive feature of several autosomal disorders, characterized by Progressive External Ophthalmoplegia (PEO), ptosis, and proximal myopathy. At least three nuclear genes are responsible for these disorders: ANT1 and C10orf2 cause autosomal dominant PEO, while mutations of DNA polymerase gammaA (POLG1 or POLG) gene on chromosome 15q25 causes both autosomal dominant and recessive forms of PEO. To investigate the contribution of these genes to the sporadic cases of PEO with multiple mtDNA deletions, we studied 31 mitochondrial myopathy patients without any family history for the disorder: 23 had PEO with myopathy, with or without the additional features of pigmentary retinopathy, ataxia, neurosensorial hypoacusia and diabetes mellitus, 7 presented isolated myopathy and one a peripheral neuropathy with ptosis.

Mitochondrial A12308G polymorphism affects clinical features in patients with single mtDNA macrodeletion.

Mitochondrial (mt)DNA alterations cause cellular energy failure and respiratory chain dysfunction. Single large-scale rearrangements represent the most common mtDNA mutations and are responsible for very variable clinical manifestations. Here, we show an increased frequency of the A12308G substitution, a common polymorphism used to define the European mtDNA haplogroup U, in mitochondrial patients carrying mtDNA single macrodeletion.

Remarkable infidelity of polymerase gammaA associated with mutations in POLG1 exonuclease domain.

Objective: To better understand the still unknown pathologic mechanism involved in the accumulation of multiple mtDNA deletions in stable tissues.

Methods: A large-scale screening of mtDNA molecules from skeletal muscle was performed in 14 patients with progressive external ophthalmoplegia (PEO) and 2 patients with mitochondrial neurogastrointestinal encephalomyopathy carrying mutations on ANT1, C10ORF2 or POLG1, and TP genes.

Results: Patients with at least one mutation in the exonuclease domain of POLG1 showed the highest frequency of individually rare point mutations only in the mtDNA control region; in addition, high levels, in terms of frequency and heteroplasmy, of recurrent mutations (A189G, T408A, and T414G) and alterations affecting the (HT)D310 region were detectable in many of the patients.

High mutational burden in the mtDNA control region from aged muscles: a single-fiber study.

The ageing process is associated with the accumulation of somatic mutations of mitochondrial DNA (mtDNA). The aged human skeletal muscle tissue presents a mosaic of fibers when stained histochemically for cytochrome c oxidase (COX) activity with a proportion of COX negative fibers. Given the potential relevance of any alteration in the mtDNA control region for replication, we analysed the correlation between the presence of mutations and their degree of heteroplasmy and the COX phenotype in individual muscle fibers of aged healthy donors.

Novel missense mutation and large deletion of GNE gene in autosomal-recessive inclusion-body myopathy.

The UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE) gene is the causative gene for autosomal-recessive hereditary inclusion-body myopathy (h-IBM). Two sisters affected with autosomal-recessive h-IBM were shown to be compound heterozygous for two novel GNE mutations: a large deletion involving exons 1-9, and a R162C amino acid change in the epimerase domain. This is the first deletion event observed in a GNE allele and expands the molecular pathogenesis of autosomal-recessive h-IBM.

The 129 codon polymorphism of the prion protein gene influences earlier cognitive performance in Down syndrome subjects.

Recently, a frequent prion protein gene (PRNP) polymorphism consisting of a methionine (M) for valine (V) substitution at codon 129 has been associated with cognitive impairment in elderly individuals. Down syndrome (DS) is associated with mental retardation and development of Alzheimer-like brain abnormalities. In the present study, we investigated the role of the PRNP polymorphism in 122 relatively young Italian DS patients.

Altered glutamate uptake in peripheral tissues from Down syndrome patients.

Overexpression of APP and SOD induces beta-amyloid deposition and oxidative stress in Down syndrome (DS) patients. Both phenomena may impair glutamate transport and decreased glutamate uptake sites have been demonstrated in patient brains at autopsy. Since alterations of APP metabolism and oxidative damage are systemic, we investigated glutamate uptake in platelets and fibroblasts from DS patients to explore whether abnormalities in this process are inherent properties of DS cells and not secondary to neurodegeneration.

Tumor necrosis factor-alpha (TNF-alpha) stimulates chemotactic response in mouse myogenic cells.

Migration of transplanted myogenic cells occurs during both embryogenesis and regeneration of skeletal muscles and is important for successful myoblast transplantation, but little is known about factors that promote chemotaxis of these cells. Tumor necrosis factor-alpha (TNF-alpha) is known to induce chemotactic effect on several cell types. In this study, we investigated its influence on the in vitro and in vivo motility of C2C12 and primary myoblasts.

Pathogen discovery from human tissue by sequence-based computational subtraction.

We have recently reported a new pathogen discovery approach, "computational subtraction". With this approach, non-human transcripts are detected by sequencing cDNA libraries from infected tissue and eliminating those transcripts that match the human genome. We show now that this method is experimentally feasible.

[Phonological processing in children with attention deficit hyperactivity disorder: is methylphenidate effective?].

Introduction: Although attention deficit hyperactivity disorder (ADHD) is usually associated with language disorders, there are few studies of phonological processing and the efficacy of psychostimulants (methylphenidate) on this.

Objective: 1. To find whether there are differences in the development of phonological processing, evaluated using linguistic segmentation tests and tests of lexical fluency with a phonetic mediator, between children with ADHD and normal children; and 2.