Advanced Optical Microscopy: Unveiling Functional Insights Regarding a Novel PPP2R1A Variant and Its Unreported Phenotype.

The number of genes implicated in neurodevelopmental conditions is rapidly growing. Recently, variants in PPP2R1A have been associated with syndromic intellectual disability and a consistent, but still expanding, phenotype. The PPP2R1A gene encodes a protein subunit of the serine/threonine protein phosphatase 2A enzyme, which plays a critical role in cellular function. We report an individual showing pontocerebellar hypoplasia (PCH), microcephaly, optic and peripheral nerve abnormalities, and an absence of typical features like epilepsy and an abnormal corpus callosum. He bears an unreported variant in an atypical region of PPP2R1A. In silico studies, functional analysis using immunofluorescence, and super-resolution microscopy techniques were performed to investigate the pathogenicity of the variant. This analysis involved a comparative analysis of the patient's fibroblasts with both healthy control cells and cells from an individual with the previously described phenotype. The results showed reduced expression of PPP2R1A and the presence of aberrant protein aggregates in the patient's fibroblasts, supporting the pathogenicity of the variant. These findings suggest a potential association between PPP2R1A variants and PCH, expanding the clinical spectrum of PPP2R1A-related neurodevelopmental disorder. Further studies and descriptions of additional patients are needed to fully understand the genotype-phenotype correlation and the underlying mechanisms of this novel phenotype.

Changes in the stool and oropharyngeal microbiome in obsessive-compulsive disorder.

Although the etiology of obsessive-compulsive disorder (OCD) is largely unknown, it is accepted that OCD is a complex disorder. There is a known bi-directional interaction between the gut microbiome and brain activity. Several authors have reported associations between changes in gut microbiota and neuropsychiatric disorders, including depression or autism. Furthermore, a pediatric-onset neuropsychiatric OCD-related syndrome occurs after streptococcal infection, which might indicate that exposure to certain microbes could be involved in OCD susceptibility. However, only one study has investigated the microbiome of OCD patients to date. We performed 16S ribosomal RNA gene-based metagenomic sequencing to analyze the stool and oropharyngeal microbiome composition of 32 OCD cases and 32 age and gender matched controls. We estimated different α- and ß-diversity measures and performed LEfSe and Wilcoxon tests to assess differences in bacterial distribution. OCD stool samples showed a trend towards lower bacterial α-diversity, as well as an increase of the relative abundance of Rikenellaceae, particularly of the genus Alistipes, and lower relative abundance of Prevotellaceae, and two genera within the Lachnospiraceae: Agathobacer and Coprococcus. However, we did not observe a different Bacteroidetes to Firmicutes ratio between OCD cases and controls. Analysis of the oropharyngeal microbiome composition showed a lower Fusobacteria to Actinobacteria ratio in OCD cases. In conclusion, we observed an imbalance in the gut and oropharyngeal microbiomes of OCD cases, including, in stool, an increase of bacteria from the Rikenellaceae family, associated with gut inflammation, and a decrease of bacteria from the Coprococcus genus, associated with DOPAC synthesis.

Neuregulin-1 promotes functional improvement by enhancing collateral sprouting in SOD1(G93A) ALS mice and after partial muscle denervation.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive degeneration of motoneurons, which is preceded by loss of neuromuscular connections in a "dying back" process. Neuregulin-1 (Nrg1) is a neurotrophic factor essential for the development and maintenance of neuromuscular junctions, and Nrg1 receptor ErbB4 loss-of-function mutations have been reported as causative for ALS. Our main goal was to investigate the role of Nrg1 type I (Nrg1-I) in SOD1(G93A) mice muscles. We overexpressed Nrg1-I by means of an adeno-associated viral (AAV) vector, and investigated its effect by means of neurophysiological techniques assessing neuromuscular function, as well as molecular approaches (RT-PCR, western blot, immunohistochemistry, ELISA) to determine the mechanisms underlying Nrg1-I action. AAV-Nrg1-I intramuscular administration promoted motor axon collateral sprouting by acting on terminal Schwann cells, preventing denervation of the injected muscles through Akt and ERK1/2 pathways. We further used a model of muscle partial denervation by transecting the L4 spinal nerve. AAV-Nrg1-I intramuscular injection enhanced muscle reinnervation by collateral sprouting, whereas administration of lapatinib (ErbB receptor inhibitor) completely blocked it. We demonstrated that Nrg1-I plays a crucial role in the collateral reinnervation process, opening a new window for developing novel ALS therapies for functional recovery rather than preservation.

Lack of synergistic effect of resveratrol and sigma-1 receptor agonist (PRE-084) in SOD1G9³A ALS mice: overlapping effects or limited therapeutic opportunity?

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is an adult onset neurodegenerative disease characterized by the loss of motoneurons (MNs) in the spinal cord, brainstem and motor cortex, causing progressive paralysis and death. Nowadays, there is no effective therapy and most patients die 2-5 years after diagnosis. Sigma-1R is a transmembrane protein highly expressed in the CNS and specially enriched in MNs. Mutations on the Sigma-1R leading to frontotemporal lobar degeneration-ALS were recently described in human patients. We previously reported the therapeutic role of the selective sigma-1R agonist 2-(4-morpholi-nethyl)1-phenylcyclohexanecarboxylate (PRE-084) in SOD1G93A ALS mice, that promoted spinal MN preservation and extended animal survival by controlling NMDA receptor calcium influx. Resveratrol (RSV, trans-3,4',5-trihydroxystilbene) is a natural polyphenol with promising neuroprotective effects. We recently found that RSV administration to SOD1G93A mice preserves spinal MN function and increases mice survival. These beneficial effects were associated to activation of Sirtuin 1 (Sirt1) and AMP-activated protein kinase (AMPK) pathways, leading to the modulation of autophagy and an increase of mitochondrial biogenesis. The main goal of this work was to assess the effect of combined RSV and PRE-084 administration in SOD1G93A ALS mice. METHODS: We determined the locomotor performance of the animals by rotarod test and evaluated spinal motoneuron function using electrophysiological tests. RESULTS: RSV plus PRE-084 treatment from 8 weeks of age significantly improved locomotor performance and spinal MN function, accompanied by a significant reduction of MN degeneration and an extension of mice lifespan. In agreement with our previous findings, there was an induction of PKC-specific phosphorylation of the NMDA-NR1 subunit and an increased expression and activation of Sirt1 and AMPK in the ventral spinal cord of treated SOD1G93A animals. CONCLUSIONS: Although combined PRE and RSV treatment significantly ameliorated SOD1G93A mice, it did not show a synergistic effect compared to RSV-only and PRE-084-only treated groups.

Treatment with anti-TNF alpha protects against the neuropathy induced by the proteasome inhibitor bortezomib in a mouse model.

Bortezomib (BTZ), a proteasome inhibitor, is an effective anti-neoplastic drug used in the treatment of multiple myeloma and mantle cell lymphoma. However, it can induce a reversible peripheral neuropathy that may lead to treatment discontinuation. The mechanism through which BTZ exerts toxic effects in peripheral neurons is not clear. Release of proinflammatory cytokines after nerve damage can induce neurodegeneration, but the effects of BTZ on cytokine expression in neurons are unknown, although BTZ modulates the expression of cytokines, such as TNF-α and IL-6, in tumor cells. The aim of this study was to evaluate the expression and the role of these cytokines on the course of BTZ induced neuropathy in mice. IL-6, TNF-α, TGF-ß1 and IL-1ß were up-regulated in dorsal root ganglia but TNF-α and IL-6 increased faster and higher. Then, we studied the potential neuroprotective effect of selective antibodies anti-TNF-α and anti-IL-6 on the evolution of the neuropathy. Treatment with anti-TNF-α but not with anti-IL-6 significantly prevented the decrease of sensory nerve action potentials amplitude and the loss of myelinated and unmyelinated fibers. We conclude that monoclonal antibodies directed against TNF-α may be a suitable neuroprotective therapy against the neurotoxicity induced by BTZ.

Di-µ-chlorido-bis-{chlorido[(R)/(S)-1,5-di-phenyl-3-(2-pyridyl-κN)-2-pyrazoline-κN]zinc(II)}.

In the centrosymmetric binuclear title compound, [Zn(2)Cl(4)(C(20)H(17)N(3))(2)], the coordination geometry of the Zn(II) ion can be described as a distorted ZnN(2)Cl(3) trigonal bipyramid (τ = 0.89), arising from the N,N'-bidentate ligand, a terminal chloride ion and two bridging chloride ions. The N atoms occupy one axial and one equatorial site and the terminal chloride ion occupies an equatorial site. The dihedral angle between the pyridine and pyrazole rings is 12.8 (2)°. In the crystal, aromatic π-π stacking [centroid-centroid separations = 3.812 (3) and 3.848 (3) Å] and C-H⋯Cl and C-H⋯π inter-actions help to establish the packing.

Nucleotide, cytogenetic and expression impact of the human chromosome 8p23.1 inversion polymorphism.

BACKGROUND: The human chromosome 8p23.1 region contains a 3.8-4.5 Mb segment which can be found in different orientations (defined as genomic inversion) among individuals. The identification of single nucleotide polymorphisms (SNPs) tightly linked to the genomic orientation of a given region should be useful to indirectly evaluate the genotypes of large genomic orientations in the individuals. RESULTS: We have identified 16 SNPs, which are in linkage disequilibrium (LD) with the 8p23.1 inversion as detected by fluorescent in situ hybridization (FISH). The variability of the 8p23.1 orientation in 150 HapMap samples was predicted using this set of SNPs and was verified by FISH in a subset of samples. Four genes (NEIL2, MSRA, CTSB and BLK) were found differentially expressed (p<0.0005) according to the orientation of the 8p23.1 region. Finally, we have found variable levels of mosaicism for the orientation of the 8p23.1 as determined by FISH. CONCLUSION: By means of dense SNP genotyping of the region, haplotype-based computational analyses and FISH experiments we could infer and verify the orientation status of alleles in the 8p23.1 region by detecting two short haplotype stretches at both ends of the inverted region, which are likely the relic of the chromosome in which the original inversion occurred. Moreover, an impact of 8p23.1 inversion on gene expression levels cannot be ruled out, since four genes from this region have statistically significant different expression levels depending on the inversion status. FISH results in lymphoblastoid cell lines suggest the presence of mosaicism regarding the 8p23.1 inversion.

Absence of cytogenetic effects in children and adults with attention-deficit/hyperactivity disorder treated with methylphenidate.

Attention-deficit/hyperactivity disorder (ADHD) is the most common psychiatric condition with onset in childhood, and in more than 50% of cases it persists into adulthood as a chronic disorder. Over five million methylphenidate (MPH) prescriptions were issued in the USA in 2003, mostly for children. A previous report [R.A. El-Zein, S.Z. Abdel-Rahman, M.J. Hay, M.S. Lopez, M.L. Bondy, D.L. Morris and M.S. Legator Cytogenetic effects in children treated with methylphenidate, Cancer Lett. 230 (2005) 284-291.] described the induction of chromosome abnormalities by MPH in children treated for three months, contrary to most of the in vitro and in vivo studies reported since then. We present new relevant information concerning the cytogenetic effects of MPH in children and adults. We include a prospective sample of 12 children and 7 adults with a new diagnosis of ADHD and naive to MPH. We analyzed the cytogenetic effects on peripheral lymphocytes before and three months after starting MPH therapy. The cytogenetic analyses included a cytokinesis-block micronucleus (CBMN) assay, a sister chromatid exchange (SCE) analysis and the determination of chromosome aberrations (CA). Following the same strategy and analyzing the same cytogenetic endpoints that were investigated in the original report [R.A. El-Zein, S.Z. Abdel-Rahman, M.J. Hay, M.S. Lopez, M.L. Bondy, D.L. Morris and M.S. Legator Cytogenetic effects in children treated with methylphenidate, Cancer Lett. 230 (2005) 284-291.], we found no evidence of increased frequency of micronuclei, sister chromatid exchanges or chromosome aberrations induced by MPH in children and adult populations. MPH treatment of children and adults with ADHD resulted in no significant genomic damage (as suggested by the three endpoints studied), results that do not support a potential increased risk of cancer after exposure to MPH.