Methamphetamine persistently increases alpha-synuclein and suppresses gene promoter methylation within striatal neurons

Abstract Methamphetamine (Meth) produces a variety of epigenetic effects in the brain, which are seminal to establish long-lasting alterations in neuronal activity. However, most epigenetic changes were described by measuring the rough amount of either histone acetylation and methylation or direct DNA methylation, without focusing on a specific DNA sequence. This point is key to comprehend Meth-induced phenotypic changes, brain plasticity, addiction and neurodegeneration. In this research paper we analyze the persistence of Meth-induced striatal synucleinopathy at a prolonged time interval of Meth withdrawal. At the same time, Meth-induced alterations, specifically within alpha-synuclein gene (SNCA) or its promoter, were evaluated. We found that exposure to high and/or prolonged doses of Meth, apart from producing nigro-striatal toxicity, determines a long-lasting increase in striatal alpha-synuclein levels. This is consistent along immune-blotting, immune-histochemistry, and electron microscopy. This was neither associated with an increase of SNCA copy number nor with alterations within SNCA sequence. However, we documented persistently demethylation within SNCA promoter, which matches the increase in alpha-synuclein protein. The amount of the native protein, which was measured stoichiometrically within striatal neurons, surpasses the increase reported following SNCA multiplications. Demethylation was remarkable (ten-fold of controls) and steady, even at prolonged time intervals being tested so far (up to 21 days of Meth withdrawal). Similarly alpha-synuclein protein assayed stoichiometrically steadily increased roughly ten-fold of controls. Meth-induced increase of alpha-synuclein was also described within limbic areas. These findings are discussed in the light of Meth-induced epigenetic changes, Meth-induced phenotype alterations, and Meth-induced neurodegeneration

Persistent paradoxical eff ects on striatal and limbic a-synuclein and tyrosine hydroxylase following methamphetamine withdrawal

Methamphetamine (METH) produces a variety of epigenetic eff ects in the brain, which are seminal to establish long-lasting alterations in neuronal activity. A number of studies were car ried out aimed at rough assessment of the amount of either histone acetylation and methyla tion or direct DNA methylation, without a selective analysis of specifi c genes. In the present study we wish to assess whether METH-induced epigenetic alterations may specifi cally engage the expression of a-synuclein, which is a key protein in neurodegeneration and synaptic plastic ity. In this way, a potential long-term alteration of brain circuitries may produce a variation in the threshold for neurotoxicity, sensitization, addiction and neurodegeneration. Thus, the occur rence of long-term changes in the expression of the protein were analyzed in parallel with per sistent changes in a specifi c marker of integrity of meso-striatal/meso-limbic pathway, which is the expression of tyrosine hydroxylase (TH) both in the mesencephalon and within dorsal striatum. The integrity of dopamine (DA) projection was assessed at the level of the olfactory tubercle, the nucleus accumbens and fundus striati. Prolonged exposure to small doses of METH, produces nigro-striatal toxicity, when assessed at short time intervals following prolonged exposure. However, at prolonged time intervals a paradoxical increase progressively occurred in TH immunostaining within limbic regions. Such an increase exceeds at large the amount of TH expressed in controls. This occurs concomitantly with an overexpression of the primary transcript as well as the protein alpha synuclein within the same brain regions and dorsal striatum. This increase is persistent at prolonged time inter val of METH withdrawal.The increase in the primary a-synuclein transcript is due to hypomethylation of specifi c CPG islands placed in the SNCA gene promoter which ranged roughly ten-fold of controls, it was steady, and it persisted at least 21 days following METH withdrawal. Thus, such an appar ent synucleinopathy induced by METH indeed was associated with increased mesolimbic DA innervation, which equally surpasses several folds the amount which was measured in controls and persists at least for three weeks. The increase in SNCA is not associated with an increase of SNCA copy number. Nonetheless, the amount of the native protein, which is detected by ultra structural stoichiometry, exceeds the increase reported following genetic SNCA multiplications (ten-fold of controls). These fi ndings are discussed in the light of METH-induced phenotype changes which accompany toxicity, sensitization, addiction and neurodegeneration

Rapamycin promotes differentiation increasing βIII-tubulin, NeuN, and NeuroD while suppressing nestin expression in glioblastoma cells

Glioblastoma cells feature mammalian target of rapamycin (mTOR) up-regulation which relates to a variety of effects such as: lower survival, higher infiltration, high stemness and radio- and chemo-resistance. Recently, it was demonstrated that mTOR may produce a gene shift leading to altered protein expression. Therefore, in the present study we administered different doses of the mTOR inhibitor rapamycin to explore whether the transcription of specific genes are modified. By using a variety of methods we demonstrate that rapamycin stimulates gene transcription related to neuronal differentiation while inhibiting stemness related genes such as nestin. In these experimental conditions, cell phenotype shifts towards a pyramidal neuron-like shape owing long branches. Rapamycin suppressed cell migration when exposed to fetal bovine serum (FBS) while increasing the cell adhesion protein phospho-FAK (pFAK). The present study improves our awareness of basic mechanisms which relate mTOR activity to the biology of glioblastoma cells. These findings apply to a variety of effects which can be induced by mTOR regulation in the brain. In fact, the ability to promote neuronal differentiation might be viewed as a novel therapeutic pathway to approach neuronal regeneration

A Large Family with p.Arg554His Mutation in ABCD1: Clinical Features and Genotype/Phenotype Correlation in Female Carriers

X-linked adrenoleukodystrophy (X-ALD, OMIM #300100) is the most common peroxisomal disorder clinically characterized by two main phenotypes: adrenomyeloneuropathy (AMN) and the cerebral demyelinating form of X-ALD (cerebral ALD). The disease is caused by defects in the gene for the adenosine triphosphate (ATP)-binding cassette protein, subfamily D (ABCD1) that encodes the peroxisomal transporter of very-long-chain fatty acids (VLCFAs). The defective function of ABCD1 protein prevents β-oxidation of VLCFAs, which thus accumulate in tissues and plasma, to represent the hallmark of the disease. As in many X-linked diseases, it has been routinely expected that female carriers are asymptomatic. Nonetheless, recent findings indicate that most ABCD1 female carriers become symptomatic, with a motor disability that typically appears between the fourth and fifth decade. In this paper, we report a large family in which affected males died during the first decade, while affected females develop, during the fourth decade, progressive lower limb weakness with spastic or ataxic-spastic gait, tetra-hyperreflexia with sensory alterations. Clinical and genetic evaluations were performed in nine subjects, eight females (five affected and three healthy) and one healthy male. All affected females were carriers of the c.1661G>A (p.Arg554His, rs201568579) mutation. This study strengthens the relevance of clinical symptoms in female carriers of ABCD1 mutations, which leads to a better understanding of the role of the genetic background and the genotype-phenotype correlation. This indicates the relevance to include ABCD1 genes in genetic panels for gait disturbance in women

Decipher non-canonical SPAST splicing mutations with the help of functional assays in patients affected by spastic paraplegia 4 (SPG4)

Flowchart showing the molecular approach used to decipher the non-canonical splicing mutations

Establishing an online resource to facilitate global collaboration and inclusion of underrepresented populations:Experience from the MJFF Global Genetic Parkinson's Disease Project

Parkinson's disease (PD) is the fastest-growing neurodegenerative disorder, currently affecting ~7 million people worldwide. PD is clinically and genetically heterogeneous, with at least 10% of all cases explained by a monogenic cause or strong genetic risk factor. However, the vast majority of our present data on monogenic PD is based on the investigation of patients of European White ancestry, leaving a large knowledge gap on monogenic PD in underrepresented populations. Gene-targeted therapies are being developed at a fast pace and have started entering clinical trials. In light of these developments, building a global network of centers working on monogenic PD, fostering collaborative research, and establishing a clinical trial-ready cohort is imperative. Based on a systematic review of the English literature on monogenic PD and a successful team science approach, we have built up a network of 59 sites worldwide and have collected information on the availability of data, biomaterials, and facilities. To enable access to this resource and to foster collaboration across centers, as well as between academia and industry, we have developed an interactive map and online tool allowing for a quick overview of available resources, along with an option to filter for specific items of interest. This initiative is currently being merged with the Global Parkinson's Genetics Program (GP2), which will attract additional centers with a focus on underrepresented sites. This growing resource and tool will facilitate collaborative research and impact the development and testing of new therapies for monogenic and potentially for idiopathic PD patients.</p

Embracing monogenic Parkinson's disease: the MJFF Global Genetic PD Cohort

© 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.Background: As gene-targeted therapies are increasingly being developed for Parkinson's disease (PD), identifying and characterizing carriers of specific genetic pathogenic variants is imperative. Only a small fraction of the estimated number of subjects with monogenic PD worldwide are currently represented in the literature and availability of clinical data and clinical trial-ready cohorts is limited. Objective: The objectives are to (1) establish an international cohort of affected and unaffected individuals with PD-linked variants; (2) provide harmonized and quality-controlled clinical characterization data for each included individual; and (3) further promote collaboration of researchers in the field of monogenic PD. Methods: We conducted a worldwide, systematic online survey to collect individual-level data on individuals with PD-linked variants in SNCA, LRRK2, VPS35, PRKN, PINK1, DJ-1, as well as selected pathogenic and risk variants in GBA and corresponding demographic, clinical, and genetic data. All registered cases underwent thorough quality checks, and pathogenicity scoring of the variants and genotype-phenotype relationships were analyzed. Results: We collected 3888 variant carriers for our analyses, reported by 92 centers (42 countries) worldwide. Of the included individuals, 3185 had a diagnosis of PD (ie, 1306 LRRK2, 115 SNCA, 23 VPS35, 429 PRKN, 75 PINK1, 13 DJ-1, and 1224 GBA) and 703 were unaffected (ie, 328 LRRK2, 32 SNCA, 3 VPS35, 1 PRKN, 1 PINK1, and 338 GBA). In total, we identified 269 different pathogenic variants; 1322 individuals in our cohort (34%) were indicated as not previously published. Conclusions: Within the MJFF Global Genetic PD Study Group, we (1) established the largest international cohort of affected and unaffected individuals carrying PD-linked variants; (2) provide harmonized and quality-controlled clinical and genetic data for each included individual; (3) promote collaboration in the field of genetic PD with a view toward clinical and genetic stratification of patients for gene-targeted clinical trials. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.Michael J. Fox Foundation for Parkinson's Research. Grant Number: ID 15015.02. NIHR Cambridge Biomedical Research Centre. Grant Number: BRC-1215-20014info:eu-repo/semantics/publishedVersio

Effects of Prolonged Seizures on Basal Forebrain Cholinergic Neurons: Evidence and Potential Clinical Relevance

Seizures originating from limbic structures, especially when prolonged for several minutes/hours up to status epilepticus (SE), can cause specific neurodegenerative phenomena in limbic and subcortical structures. The cholinergic nuclei belonging to the basal forebrain (BF) (namely, medial septal nucleus (MSN), diagonal band of Broca (DBB), and nucleus basalis of Meynert (NBM)) belong to the limbic system, while playing a pivotal role in cognition and sleep-waking cycle. Given the strong interconnections linking these limbic nuclei with limbic cortical structures, a persistent effect of SE originating from limbic structures on cBF morphology is plausible. Nonetheless, only a few experimental studies have addressed this issue. In this review, we describe available data and discuss their significance in the scenario of seizure-induced brain damage. In detail, the manuscript moves from a recent study in a model of focally induced limbic SE, in which the pure effects of seizure spreading through the natural anatomical pathways towards the&nbsp;cholinergic nuclei of BF were&nbsp;tracked by neuronal degeneration. In this experimental setting, a loss of cholinergic neurons was measured in all BF nuclei, to various extents depending on the specific nucleus. These findings are discussed in the light of the effects on the very same nuclei following SE induced by systemic injections of kainate or pilocarpine. The various effects including discrepancies among different studies are discussed. Potential implications for human diseases are included

An attempt to dissect a peripheral marker based on cell pathology in Parkinson's disease

Peripheral markers in Parkinson's disease (PD) represent a hot issue to provide early diagnosis and assess disease progression. The gold standard marker of PD should feature the same reliability as the pathogenic alteration, which produces the disease itself. PD is foremost a movement disorder produced by a loss of nigrostriatal dopamine innervation, in which striatal dopamine terminals are always markedly reduced in PD patients to an extent, which never overlaps with controls. Similarly, a reliable marker of PD should possess such a non-overlapping feature when compared with controls. In the present study, we provide a novel pathological hallmark, the autophagosome, which in each PD patient was always suppressed compared with each control subject. Autophagosomes were counted as microtubule-associated proteins 1A/1B light chain 3B (LC3)-positive vacuoles at ultrastructural morphometry within peripheral (blood) blood mononuclear cells (PBMC). This also provides the gold standard to assess the autophagy status. Since autophagy may play a role in the pathogenesis of PD, autophagosomes may be a disease marker, while participating in the biology of the disease. Stoichiometric measurement of alpha-synuclein despite significantly increased in PD patients, overlapped between PD and control patients. Although the study need to be validated in large populations, the number of autophagy vacuoles is neither related with therapy (the amount was similarly suppressed in a few de novo patients), nor the age in PD or controls

Occurrence of Total and Proteinase K-Resistant Alpha-Synuclein in Glioblastoma Cells Depends on mTOR Activity

Alpha-synuclein (-syn) is a protein considered to be detrimental in a number of degenerative disorders (synucleinopathies) of which -syn aggregates are considered a pathological hallmark. The clearance of -syn strongly depends on autophagy, which can be stimulated by inhibiting the mechanistic target of rapamycin (mTOR). Thus, the overexpression of mTOR and severe autophagy suppression may produce -syn accumulation, including the proteinase K-resistant protein isoform. Glioblastoma multiforme (GBM) is a lethal brain tumor that features mTOR overexpression and severe autophagy inhibition. Cell pathology in GBM is reminiscent of a fast, progressive degenerative disorder. Therefore, the present work questions whether, as is analogous to neurons during degenerative disorders, an overexpression of -syn occurs within GBM cells. A high amount of -syn was documented in GBM cells via real-time PCR (RT-PCR), Western blotting, immunohistochemistry, immuno-fluorescence, and ultrastructural stoichiometry, compared with the amount of a e b -synucleins and compared with the amount of -syn counted within astrocytes. The present study indicates that (i) -syn is overexpressed in GBM cells, (ii) -syn expression includes a proteinase-K resistant isoform, (iii) -syn is dispersed from autophagy-like vacuoles to the cytosol, (iv) -syn overexpression and cytosol dispersion are mitigated by rapamycin, and (v) the -syn-related GBM-like phenotype is mitigated by silencing the SNCA gene