DNA methylome, R-loop and clinical exome profiling of patients with sporadic amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by the death of motor neurons, the aetiology of which is essentially unknown. Here, we present an integrative epigenomic study in blood samples from seven clinically characterised sporadic ALS patients to elucidate molecular factors associated with the disease. We used clinical exome sequencing (CES) to study DNA variants, DNA-RNA hybrid immunoprecipitation sequencing (DRIP-seq) to assess R-loop distribution, and reduced representation bisulfite sequencing (RRBS) to examine DNA methylation changes. The above datasets were combined to create a comprehensive repository of genetic and epigenetic changes associated with the ALS cases studied. This repository is well-suited to unveil new correlations within individual patients and across the entire patient cohort. The molecular attributes described here are expected to guide further mechanistic studies on ALS, shedding light on the underlying genetic causes and facilitating the development of new epigenetic therapies to combat this life-threatening disease.

Single Nucleotide Polymorphisms of Indoleamine 2,3-Dioxygenase 1 Influenced the Age Onset of Parkinson's Disease.

BACKGROUND: Earlier studies reported alterations of the kynurenine (KYN) pathway of tryptophan (TRP) metabolism in Parkinson's disease (PD). The first rate-limiting enzymes indoleamine 2,3-dioxygenase (IDO) and tryptophan dioxygenase were observed upregulated, resulting elevated KYN/TRP ratios in the serum and cerebrospinal fluid samples of patients with PD. More and more single nucleotide polymorphisms (SNPs) have been identified in a population of PD. However, little is known about the impact of genetic variations of the IDO on the pathogenesis of PD. METHODS: SNP analysis of IDO1 was performed by allelic discrimination assay with fluorescently labelled TaqMan probes and a subgroup analysis was conducted according to the age of PD onset. The frame shifts variant rs34155785, intronic variant rs7820268, and promotor region variant rs9657182 SNPs of 105 PD patients without comorbidity were analyzed and compared to 129 healthy controls. RESULTS: No significant correlation was found in three SNPs between PD patients and healthy controls. However, the subgroup analysis revealed that A alleles of rs7820268 SNP or rs9657182 SNP carriers contribute to later onset of PD than non-carriers. CONCLUSIONS: The study suggested that SNPs of IDO1 influenced the age onset of PD and genotyping of SNPs in certain alleles potentially serves as a risk biomarker of PD.

Co-Players in Chronic Pain: Neuroinflammation and the Tryptophan-Kynurenine Metabolic Pathway.

Chronic pain is an unpleasant sensory and emotional experience that persists or recurs more than three months and may extend beyond the expected time of healing. Recently, nociplastic pain has been introduced as a descriptor of the mechanism of pain, which is due to the disturbance of neural processing without actual or potential tissue damage, appearing to replace a concept of psychogenic pain. An interdisciplinary task force of the International Association for the Study of Pain (IASP) compiled a systematic classification of clinical conditions associated with chronic pain, which was published in 2018 and will officially come into effect in 2022 in the 11th revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-11) by the World Health Organization. ICD-11 offers the option for recording the presence of psychological or social factors in chronic pain; however, cognitive, emotional, and social dimensions in the pathogenesis of chronic pain are missing. Earlier pain disorder was defined as a condition with chronic pain associated with psychological factors, but it was replaced with somatic symptom disorder with predominant pain in the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) in 2013. Recently clinical nosology is trending toward highlighting neurological pathology of chronic pain, discounting psychological or social factors in the pathogenesis of pain. This review article discusses components of the pain pathway, the component-based mechanisms of pain, central and peripheral sensitization, roles of chronic inflammation, and the involvement of tryptophan-kynurenine pathway metabolites, exploring the participation of psychosocial and behavioral factors in central sensitization of diseases progressing into the development of chronic pain, comorbid diseases that commonly present a symptom of chronic pain, and psychiatric disorders that manifest chronic pain without obvious actual or potential tissue damage.

Crosstalk between Existential Phenomenological Psychotherapy and Neurological Sciences in Mood and Anxiety Disorders.

Psychotherapy is a comprehensive biological treatment modifying complex underlying cognitive, emotional, behavioral, and regulatory responses in the brain, leading patients with mental illness to a new interpretation of the sense of self and others. Psychotherapy is an art of science integrated with psychology and/or philosophy. Neurological sciences study the neurological basis of cognition, memory, and behavior as well as the impact of neurological damage and disease on these functions, and their treatment. Both psychotherapy and neurological sciences deal with the brain; nevertheless, they continue to stay polarized. Existential phenomenological psychotherapy (EPP) has been in the forefront of meaning-centered counseling for almost a century. The phenomenological approach in psychotherapy originated in the works of Martin Heidegger, Ludwig Binswanger, Medard Boss, and Viktor Frankl, and it has been committed to accounting for the existential possibilities and limitations of one's life. EPP provides philosophically rich interpretations and empowers counseling techniques to assist mentally suffering individuals by finding meaning and purpose to life. The approach has proven to be effective in treating mood and anxiety disorders. This narrative review article demonstrates the development of EPP, the therapeutic methodology, evidence-based accounts of its curative techniques, current understanding of mood and anxiety disorders in neurological sciences, and a possible converging path to translate and integrate meaning-centered psychotherapy and neuroscience, concluding that the EPP may potentially play a synergistic role with the currently prevailing medication-based approaches for the treatment of mood and anxiety disorders.

Searching for Peripheral Biomarkers in Neurodegenerative Diseases: The Tryptophan-Kynurenine Metabolic Pathway.

Neurodegenerative diseases are multifactorial, initiated by a series of the causative complex which develops into a certain clinical picture. The pathogenesis and disease course vary from patient to patient. Thus, it should be likewise to the treatment. Peripheral biomarkers are to play a central role for tailoring a personalized therapeutic plan for patients who suffered from neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and multiple sclerosis, among others. Nevertheless, the use of biomarkers in clinical practice is still underappreciated and data presented in biomarker research for clinical use is still uncompelling, compared to the abundant data available for drug research and development. So is the case with kynurenines (KYNs) and the kynurenine pathway (KP) enzymes, which have been associated with a wide range of diseases including cancer, autoimmune diseases, inflammatory diseases, neurologic diseases, and psychiatric disorders. This review article discusses current knowledge of KP alterations observed in the central nervous system as well as the periphery, its involvement in pathogenesis and disease progression, and emerging evidence of roles of microbiota in the gut-brain axis, searching for practical peripheral biomarkers which ensure personalized treatment plans for neurodegenerative diseases.

The rs13388259 Intergenic Polymorphism in the Genomic Context of the BCYRN1 Gene Is Associated with Parkinson's Disease in the Hungarian Population.

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by bradykinesia, resting tremor, and muscle rigidity. To date, approximately 50 genes have been implicated in PD pathogenesis, including both Mendelian genes with rare mutations and low-penetrance genes with common polymorphisms. Previous studies of low-penetrance genes focused on protein-coding genes, and less attention was given to long noncoding RNAs (lncRNAs). In this study, we aimed to investigate the susceptibility roles of lncRNA gene polymorphisms in the development of PD. Therefore, polymorphisms (n=15) of the PINK1-AS, UCHL1-AS, BCYRN1, SOX2-OT, ANRIL and HAR1A lncRNAs genes were genotyped in Hungarian PD patients (n=160) and age- and sex-matched controls (n=167). The rare allele of the rs13388259 intergenic polymorphism, located downstream of the BCYRN1 gene, was significantly more frequent among PD patients than control individuals (OR = 2.31; p=0.0015). In silico prediction suggested that this polymorphism is located in a noncoding region close to the binding site of the transcription factor HNF4A, which is a central regulatory hub gene that has been shown to be upregulated in the peripheral blood of PD patients. The rs13388259 polymorphism may interfere with the binding affinity of transcription factor HNF4A, potentially resulting in abnormal expression of target genes, such as BCYRN1.

High-throughput sequencing revealed a novel SETX mutation in a Hungarian patient with amyotrophic lateral sclerosis.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the degeneration of the motor neurons. To date, 126 genes have been implicated in ALS. Therefore, the heterogenous genetic background of ALS requires comprehensive genetic investigative approaches. METHODS: In this study, DNA from 28 Hungarian ALS patients was subjected to targeted high-throughput sequencing of the coding regions of three Mendelian ALS genes: FUS, SETX, and C9ORF72. RESULTS: A novel heterozygous missense mutation (c.791A>G, p.N264S) of the SETX gene was identified in a female patient presenting an atypical ALS phenotype, including adult onset and lower motor neuron impairment. No further mutations were detected in the other Mendelian ALS genes investigated. CONCLUSION: Our study contributes to the understanding of the genetic and phenotypic diversity of motor neuron diseases (MNDs). Our results also suggest that the elucidation of the genetic background of MNDs requires a complex approach, including the screening of both Mendelian and non-Mendelian genes.

Genetic analysis of the SOD1 and C9ORF72 genes in Hungarian patients with amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the death of motor neurons. To date, more than 20 genes have been implicated in ALS, and of these, the 2 most frequently mutated are the superoxide dismutase 1 (SOD1) gene and the chromosome 9 open reading frame 72 (C9ORF72) gene. In this study, we aimed to investigate the contribution of these 2 Mendelian genes to the development of the disease in Hungarian ALS patients (n = 66). Direct sequencing of the SOD1 gene revealed a novel (p.Lys91ArgfsTer8) and 3 recurrent heterozygous mutations (p.Val14Met, p.Asp90Ala, and p.Leu144Phe) in 5 patients. The novel p.Lys91ArgfsTer8 mutation led to a frameshift causing the addition of 8 new amino acids, including a premature stop codon at position 99. The GGGGCC hexanucleotide repeat expansion of the C9ORF72 gene was present in 1 ALS patient. This study represents the first genetic analysis of 2 major ALS causative genes in a cohort of Hungarian ALS patients and contributes to the further understanding of the genetic and phenotypic diversity of ALS.

Investigational α-synuclein aggregation inhibitors: hope for Parkinson's disease.

INTRODUCTION: The therapeutic management of Parkinson's disease (PD) is challenging and has not been fully resolved. The main challenges include motor fluctuations and levodopa-induced dyskinesia. Moreover, no disease-modifying or neuroprotective therapy is currently available. Areas covered: This review focuses on α-synuclein aggregation inhibitors and their therapeutic role in PD, with special attention to heat shock proteins, immunotherapy (active and passive), the potential of targeting the Ser129 phosphorylation site, and the antibiotic possibilities. Expert opinion: The induction of chaperones may provide beneficial strategy to target synucleinopathies, but further investigations are needed to find the best options. The promising preclinical results with immunotherapy suggest that it may be a valuable disease-modifying therapy in PD in the future. Clinical trials are currently in the initial phases, and future studies need to confirm the beneficial therapeutic effect in humans and clarify open questions as regards the exact mode of action and potential safety concerns. In case of covalent modifications, phosphorylation of α-synuclein is of outstanding importance; however, conflicting results and open questions exist which necessitate clarification. In vitro results suggest that several antibiotics may also influence α-synuclein aggregation, but these results are to be confirmed in the future.

Promising therapeutic agents for the treatment of Parkinson's disease.

INTRODUCTION: The therapeutic management of Parkinson's disease has not yet been fully resolved, with motor fluctuations and levodopa-induced dyskinesia representing special therapeutic challenges. Furthermore, no disease-modifying therapies are currently available. AREAS COVERED: This review focuses on promising novel therapies that are at present under investigation in Phase I or Phase II trials. Special emphasis is placed on gene therapies: vectors, the utilized gene constructs and the side-effects. Moreover, the main risk factors of the gene therapy (the insertional mutagenesis, the uncontrolled overproduction of the expressed protein and the autoimmune and inflammatory responses) are described. EXPERT OPINION: Gene therapies represent a promising field in the therapeutic palette. In order to mitigate the side-effects of this therapy, the developments focus on the vectors applied. Gene therapy appears to be promising candidate for the management of motor complications in advanced stages of Parkinson's disease. In addition to dopamine replacement therapy, this field may also offer a solution for neurogenesis and neuroprotection.

An assessment of the frequency of mutations in the GBA and VPS35 genes in Hungarian patients with sporadic Parkinson's disease.

Parkinson's disease (PD) is the second most common neurodegenerative disorder, with cases of either familial or sporadic origin. Several polymorphisms in a number of genes have been proved to have an important role in the development of PD. Particular attention has recently been paid to genes of the glucocerebrosidase (GBA) and the vacuolar protein sorting-associated protein 35 (VPS35). In this study, the three most common mutations (L444P, N370S and R120W) of the GBA gene and the D620N mutation of the VPS35 gene were examined in 124 Hungarian patients diagnosed with sporadic PD (SPD) and 122 control subjects. The frequency of the L444P mutation of the GBA gene proved to be higher in the PD patients (2.4%) than in the controls (0%), although the difference was not statistically significant. All the patients who carried the mutant allele were in the early-onset PD (EOPD) group. However, neither the R120W nor the N370S variant of the GBA gene nor D620N mutation of the VPS35 gene were detected among the PD cases or the controls. Even though these results suggest that the studied mutations are quite rare in SPD patients, the most frequent L444P mutation of the GBA gene may be associated with the development of EOPD in the Hungarian population.

Memantine and Kynurenic Acid: Current Neuropharmacological Aspects.

Glutamatergic neurotransmission, of special importance in the human brain, is implicated in key brain functions such as synaptic plasticity and memory. The excessive activation of N-methyl- D-aspartate (NMDA) receptors may result in excitotoxic neuronal damage; this process has been implicated in the pathomechanism of different neurodegenerative disorders, such as Alzheimer's disease (AD). Memantine is an uncompetitive antagonist of NMDA receptors with a favorable pharmacokinetic profile, and is therefore clinically well tolerated. Memantine is approved for the treatment of AD, but may additionally be beneficial for other dementia forms and pain conditions. Kynurenic acid (KYNA) is an endogenous antagonist of NMDA receptors which has been demonstrated under experimental conditions to be neuroprotective. The development of a well-tolerated NMDA antagonist may offer a novel therapeutic option for the treatment of neurodegenerative disease and pain syndromes. KYNA may be a valuable candidate for future drug development.

Brain Aging and Disorders of the Central Nervous System: Kynurenines and Drug Metabolism.

INTRODUCTION: The kynurenine pathway includes several neuroactive compounds, including kynurenic acid, picolinic acid, 3-hydroxykynurenine and quinolinic acid. The enzymatic cascade of the kynurenine pathway is tightly connected with the immune system, and may provide a link between the immune system and neurotransmission. Main Areas Covered: Alterations in this cascade are associated with neurodegenerative, neurocognitive, autoimmune and psychiatric disorders, such as Parkinson's disease, Huntington's disease, Alzheimer's disease, multiple sclerosis, amyotrophic lateral sclerosis, migraine or schizophrenia. HIGHLIGHTS: This review highlights the alterations in this metabolic pathway in the physiological aging process and in different disorders. A survey is also presented of therapeutic possibilities of influencing this metabolic route, which can be achieved through the use of synthetic kynurenic acid analogues, enzyme inhibitors or even nanotechnology.

The Genetic Link between Parkinson's Disease and the Kynurenine Pathway Is Still Missing.

Background. There is substantial evidence that the kynurenine pathway (KP) plays a role in the normal physiology of the brain and is involved in the pathology of neurodegenerative disorders such as Huntington's disease and Parkinson's disease (PD). Objective. We set out to investigate the potential roles in PD of single nucleotide polymorphisms (SNPs) from one of the key enzymes of the KP, kynurenine 3-monooxygenase (KMO). Methods. 105 unrelated, clinically definitive PD patients and 131 healthy controls were enrolled to investigate the possible effects of the different alleles of KMO. Fluorescently labeled TaqMan probes were used for allele discrimination. Results. None of the four investigated SNPs proved to be associated with PD or influenced the age at onset of the disease. Conclusions. The genetic link between the KP and PD is still missing. The investigated SNPs presumably do not appear to influence the function of KMO and probably do not contain binding sites for regulatory proteins of relevance in PD. This is the first study to assess the genetic background behind the biochemical alterations of the kynurenine pathway in PD, directing the attention to this previously unexamined field.

Chemokine receptor V Δ32 deletion in multiple sclerosis patients in Csongrád County in Hungary and the North-Bácska region in Serbia.

The roles of chemokine receptor V (CCR5) and its polymorphism, rs333 in multiple sclerosis (MS) are controversial. We investigated the receptor and its deletion in a large MS (428) and a numerous control (831) population in Csongrád County (Hungary) and North-Bácska (Serbia). Taqman probes firstly were used for the allele discrimination. There was no significant difference in genotype (OR=1.092, 95% CI=0.807-1.478, p=0.568 for wt/wt (wt=wild type allele) vs wt/Δ32, Δ32/Δ32 (Δ32=Δ32 base pair deletion allele)) or allele frequency (OR=0.914, 95% CI=0.692-1.207, p=0.525). Neither the deletion nor the wt allele affected the Expanded Disability Status Scale score or the age at onset. Our results indicate no association between the CCR5 Δ32 allele and MS.

Association of vitamin D receptor gene polymorphisms and Parkinson's disease in Hungarians.

Vitamin D receptor (VDR) gene encodes a transcription factor that influences calcium homeostasis and immunoregulation, and may play a role in neurological disorders including Parkinson's disease (PD). The investigations of the association between VDR and PD in different populations revealed various results. In a present study 100 PD patients and 109 healthy controls from the Hungarian population were genotyped for four polymorphic sites (BsmI, ApaI, FokI and TaqI) in the VDR gene. The polymorphisms were determined by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). Our results demonstrate an association between the FokI C allele and PD; the frequency of the C allele was significantly higher in PD patients than in controls, suggesting that this polymorphism may have a role in the development of PD in these patients.

Rapid genotyping of genetically modified laboratory animals from whole blood samples without DNA preparation.

A new, rapid method is described which permits the genotyping of genetically modified animals from a microlitre volume of whole blood samples via one step polymerase chain reaction amplification. The major advantage of the presented method is the exclusion of a DNA preparation step, which significantly reduces the time expenditure and work load of the genetic testing. Pilot studies indicate, that this method is efficient and applicable also on tissue biopsies and larger amount of blood providing a rapid and reliable new technique over conventional genotyping approaches.