Paving a way to treat spastic paraplegia 50.

Spastic paraplegia 50 (SPG50) is a rare neurodegenerative disease caused by loss-of-function mutations in AP4M1. There are no effective treatments for SPG50 or any other type of SPG, and current treatments are limited to symptomatic management. In this issue of the JCI, Chen et al.

Tyrosine phosphorylation of NLRP3 by the Src family kinase Lyn suppresses the activity of the NLRP3 inflammasome.

In response to microbes and other danger signals, the NLRP3 inflammasome in immune cells triggers the activation of the protease caspase-1, which mediates the maturation of the inflammatory cytokine IL-1β. Here, we investigated how the NLRP3 inflammasome is regulated. We found that its activation in primary mouse macrophages induced the Src family kinase Lyn to phosphorylate NLRP3 at Tyr, which correlated with a subsequent increase in its ubiquitination that facilitated its proteasome-mediated degradation.

Efficacy and long-term safety of CRISPR/Cas9 genome editing in the SOD1-linked mouse models of ALS.

CRISPR/Cas9-mediated genome editing provides potential for therapeutic development. Efficacy and long-term safety represent major concerns that remain to be adequately addressed in preclinical studies. Here we show that CRISPR/Cas9-mediated genome editing in two distinct SOD1-amyotrophic lateral sclerosis (ALS) transgenic mouse models prevented the development of ALS-like disease and pathology.

Early death of ALS-linked CHCHD10-R15L transgenic mice with central nervous system, skeletal muscle, and cardiac pathology.

Mutations in coiled-coil-helix-coiled-coil-helix domain containing 10 () have been identified in patients suffering from various degenerative diseases including mitochondrial myopathy, spinal muscular atrophy Jokela type, frontotemporal dementia, and/or amyotrophic lateral sclerosis (ALS). The pathogenic mechanism underlying -linked divergent disorders remains largely unknown. Here we show that transgenic mice overexpressing an ALS-linked CHCHD10 p.

Glutathione Reductase Promotes Fungal Clearance and Suppresses Inflammation during Systemic Infection in Mice.

Glutathione reductase (Gsr) catalyzes the reduction of glutathione disulfide to glutathione, which plays an important role in redox regulation. We have previously shown that Gsr facilitates neutrophil bactericidal activities and is pivotal for host defense against bacterial pathogens. However, it is unclear whether Gsr is required for immune defense against fungal pathogens.

Incidence and Clinical Features of TRPV4-Linked Axonal Neuropathies in a USA Cohort of Charcot-Marie-Tooth Disease Type 2.

Mutations in TRPV4 are linked to a group of clinically distinct, but also overlapping axonal neuropathies, including Charcot-Marie-Tooth disease type 2C (CMT2C), scapuloperoneal spinal muscular atrophy, and congenital distal spinal muscular atrophy. The incidence of TRPV4-linked cases ranges from 0 to 7% in overall axonal neuropathy cohorts from European countries and Australia. However, the data from other areas remain largely unknown.

Loss-of-function mutations in TDRD7 lead to a rare novel syndrome combining congenital cataract and nonobstructive azoospermia in humans.

Purpose: Comorbid familial nonobstructive azoospermia (NOA) and congenital cataract (CC) have not been reported previously, and no single human gene has been associated with both diseases in humans. Our purpose was to uncover novel human mutations and genes causing familial NOA and CC.

Methods: We performed whole-exome sequencing for two brothers with both NOA and CC from a consanguineous family.

A novel ALS-associated variant in regulates motor axon morphogenesis.

The etiological underpinnings of amyotrophic lateral sclerosis (ALS) are complex and incompletely understood, although contributions to pathogenesis by regulators of proteolytic pathways have become increasingly apparent. Here, we present a novel variant in that is associated with ALS and show that its expression compromises motor axon morphogenesis in mouse motor neurons and in zebrafish. We further demonstrate that the ALS-associated variant impairs proteasomal function, and identify the Wnt signaling pathway effector beta-catenin as a substrate.

Nuclear export of misfolded SOD1 mediated by a normally buried NES-like sequence reduces proteotoxicity in the nucleus.

Over 170 different mutations in the gene encoding SOD1 all cause amyotrophic lateral sclerosis (ALS). Available studies have been primarily focused on the mechanisms underlying mutant SOD1 cytotoxicity. How cells defend against the cytotoxicity remains largely unknown.

Sirt3 protects dopaminergic neurons from mitochondrial oxidative stress.

Age-dependent elevation in mitochondrial oxidative stress is widely posited to be a major factor underlying the loss of substantia nigra pars compacta (SNc) dopaminergic neurons in Parkinson's disease (PD). However, mechanistic links between aging and oxidative stress are not well understood. Sirtuin-3 (Sirt3) is a mitochondrial deacetylase that could mediate this connection.

The Parkinson's disease-linked protein TMEM230 is required for Rab8a-mediated secretory vesicle trafficking and retromer trafficking.

TMEM230 is a newly identified Parkinson's disease (PD) gene encoding a transmembrane protein whose cellular and pathogenic roles remain largely unknown. Here, we demonstrate that loss of TMEM230 disrupts retromer cargo CI-M6PR (cation-independent mannose 6-phosphate receptor) trafficking and autophagic cargo degradation rates. TMEM230 depletion further inhibits extracellular secretion of the autophagic cargo p62 and immature lysosomal hydrolases in Golgi-derived vesicles leading to their intracellular accumulation, and is specifically mediated by loss of the small GTPase Rab8a.

Early Impairment of Synaptic and Intrinsic Excitability in Mice Expressing ALS/Dementia-Linked Mutant UBQLN2.

Frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) are believed to represent the different outcomes of a common pathogenic mechanism. However, while researchers have intensely studied the involvement of motor neurons in the ALS/FTD syndrome, very little is known about the function of hippocampal neurons, although this area is critical for memory and other cognitive functions. We investigated the electrophysiological properties of CA1 pyramidal cells in slices from 1 month-old UBQLN2 mice, a recently generated model of ALS/FTD that shows heavy depositions of ubiquilin2-positive aggregates in this brain region.

Identification of TMEM230 mutations in familial Parkinson's disease.

Parkinson's disease is the second most common neurodegenerative disorder without effective treatment. It is generally sporadic with unknown etiology. However, genetic studies of rare familial forms have led to the identification of mutations in several genes, which are linked to typical Parkinson's disease or parkinsonian disorders.

Exome Sequencing of a Pedigree Reveals S339L Mutation in the TLN2 Gene as a Cause of Fifth Finger Camptodactyly.

Camptodactyly is a digit deformity characterized by permanent flexion contracture of one or both fifth fingers at the proximal interphalangeal joints. Though over 60 distinct types of syndromic camptodactyly have been described, only one disease locus (3q11.2-q13.

Clinicopathologic report of ocular involvement in ALS patients with C9orf72 mutation.

Our objective was to present clinicopathologic evidence of anterior visual pathway involvement in patients with amyotrophic lateral sclerosis (ALS) secondary to a C9orf72 mutation. Two related patients from an extended pedigree with ALS and GGGGCC hexanucleotide repeat expansion in the C9orf72 gene (C9-ALS) underwent neuro-ophthalmologic examination. Following death and tissue donation of the younger ALS patient, histopathologic examination of the retina, optic nerve and central nervous system (CNS) was performed.

Dendritic spinopathy in transgenic mice expressing ALS/dementia-linked mutant UBQLN2.

Mutations in the gene encoding ubiquilin2 (UBQLN2) cause amyotrophic lateral sclerosis (ALS), frontotemporal type of dementia, or both. However, the molecular mechanisms are unknown. Here, we show that ALS/dementia-linked UBQLN2(P497H) transgenic mice develop neuronal pathology with ubiquilin2/ubiquitin/p62-positive inclusions in the brain, especially in the hippocampus, recapitulating several key pathological features of dementia observed in human patients with UBQLN2 mutations.

Mutation in the novel nuclear-encoded mitochondrial protein CHCHD10 in a family with autosomal dominant mitochondrial myopathy.

Mitochondrial myopathies belong to a larger group of systemic diseases caused by morphological or biochemical abnormalities of mitochondria. Mitochondrial disorders can be caused by mutations in either the mitochondrial or nuclear genome. Only 5% of all mitochondrial disorders are autosomal dominant.

Alzheimer disease and amyotrophic lateral sclerosis: an etiopathogenic connection.

The etiopathogenesis of neither the sporadic form of Alzheimer disease (AD) nor of amyotrophic lateral sclerosis (ALS) is well understood. The activity of protein phosphatase-2A (PP2A), which regulates the phosphorylation of tau and neurofilaments, is negatively regulated by the myeloid leukemia-associated protein SET, also known as inhibitor-2 of PP2A, I2(PP2A). In AD brain, PP2A activity is compromised, probably because I2(PP2A) is overexpressed and is selectively cleaved at asparagine 175 into an N-terminal fragment, I2NTF, and a C-terminal fragment, I2CTF, and both fragments inhibit PP2A.

Iron accumulation in deep cortical layers accounts for MRI signal abnormalities in ALS: correlating 7 tesla MRI and pathology.

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder characterized by cortical and spinal motor neuron dysfunction. Routine magnetic resonance imaging (MRI) studies have previously shown hypointense signal in the motor cortex on T(2)-weighted images in some ALS patients, however, the cause of this finding is unknown. To investigate the utility of this MR signal change as a marker of cortical motor neuron degeneration, signal abnormalities on 3T and 7T MR images of the brain were compared, and pathology was obtained in two ALS patients to determine the origin of the motor cortex hypointensity.