Preclinical Evidence of Nogo-A Inhibition in Stroke Recovery: A Scoping Review.

Stroke is one of the leading causes of disability worldwide. Although preclinical studies have shown promising results of pharmacotherapies to enhance stroke recovery, no drug has been approved for stroke recovery in patients. In this article, we review the preclinical data of one promising treatment, inhibition of NgR1 (Nogo receptor 1) signaling, for stroke recovery.

mGluR4-Npdc1 complex mediates α-synuclein fibril-induced neurodegeneration.

Fibrils of misfolded α-synuclein (α-syn) accumulate in Parkinson's disease and other synucleinopathies, spreading between cells to template further misfolding and drive neurodegeneration. α-syn fibril entry into healthy neurons is recognized as a key step in the disease process but remains ill-defined mechanistically. Here, we comprehensively assessed the membrane proteome for binding of α-syn fibrils.

The role of endolysosomal progranulin and TMEM106B in neurodegenerative diseases.

Although different neurodegenerative diseases are defined by distinct pathological proteins, they share many common features including protein aggregation. Despite this commonality, most current therapeutic approaches in the field, such as anti-aggregate antibodies, are focused on individual diseases or single neuropathologies with only limited success. The endolysosomal proteins progranulin and TMEM106B were both initially associated with frontotemporal lobar degeneration but have subsequently also been linked to other neurodegenerative diseases.

Multi-ancestry genome-wide meta-analysis of 56,241 individuals identifies known and novel cross-population and ancestry-specific associations as novel risk loci for Alzheimer's disease.

Background: Limited ancestral diversity has impaired our ability to detect risk variants more prevalent in ancestry groups of predominantly non-European ancestral background in genome-wide association studies (GWAS). We construct and analyze a multi-ancestry GWAS dataset in the Alzheimer's Disease Genetics Consortium (ADGC) to test for novel shared and population-specific late-onset Alzheimer's disease (LOAD) susceptibility loci and evaluate underlying genetic architecture in 37,382 non-Hispanic White (NHW), 6728 African American, 8899 Hispanic (HIS), and 3232 East Asian individuals, performing within ancestry fixed-effects meta-analysis followed by a cross-ancestry random-effects meta-analysis.

Results: We identify 13 loci with cross-population associations including known loci at/near CR1, BIN1, TREM2, CD2AP, PTK2B, CLU, SHARPIN, MS4A6A, PICALM, ABCA7, APOE, and two novel loci not previously reported at 11p12 (LRRC4C) and 12q24.

[F]SynVesT-1 PET Detects SV2A Changes in the Spinal Cord and Brain of Rats with Spinal Cord Injury.

Traumatic spinal cord injury (SCI) is a devastating neurologic condition lacking effective prognostic and treatment methods. PET imaging of synaptic vesicle glycoprotein 2A (SV2A) has been used in measuring synapse changes. We explore the feasibility of using [F]SynVesT-1 PET to detect the synaptic changes in a rat model of SCI.

Crossing the Valley of Death in Spinal Cord Injury: Learning from Successful Translators.

A straightforward path to successful scientific translation remains uncharted, particularly in a complex progressive condition such as spinal cord injury (SCI), which affects multiple body functions simultaneously. Evolving regulatory requirements add to the complexity and expense of attaining a treatment that is both safe and efficacious. Although rare, there are examples of SCI scientists who have successfully navigated the "valley of death" from discovery science to completed clinical trials.

The neuropathologic basis for translational biomarker development in the macaque model of late-onset Alzheimer's disease.

BackgroundAccurate placement of the macaque within the Alzheimer's disease (AD) research framework is essential to discover early-stage predictive biomarkers.ObjectiveTo assess utility of the aging macaque in advancing translational biomarker development for preclinical AD, we evaluated relative signal strength of comparable neuropathologic phenomena in macaques and patients.MethodsWe compared pathology in patient and macaque formalin-fixed paraffin embedded (FFPE) tissues using identical criteria.

Aging-dependent loss of functional connectivity in a mouse model of Alzheimer's disease and reversal by mGluR5 modulator.

Amyloid accumulation in Alzheimer's disease (AD) is associated with synaptic damage and altered connectivity in brain networks. While measures of amyloid accumulation and biochemical changes in mouse models have utility for translational studies of certain therapeutics, preclinical analysis of altered brain connectivity using clinically relevant fMRI measures has not been well developed for agents intended to improve neural networks. Here, we conduct a longitudinal study in a double knock-in mouse model for AD (App/hMapt), monitoring brain connectivity by means of resting-state fMRI.

Cellular Prion Protein Conformational Shift after Liquid-Liquid Phase Separation Regulated by a Polymeric Antagonist and Mutations.

Liquid-liquid phase separation (LLPS) of intrinsically disordered proteins has been associated with neurodegenerative diseases, although direct mechanisms are poorly defined. Here, we report on a maturation process for the cellular prion protein (PrP) that involves a conformational change after LLPS and is regulated by mutations and poly(4-styrenesulfonic acid--maleic acid) (PSCMA), a molecule that has been reported to rescue Alzheimer's disease-related cognitive deficits by antagonizing the interaction between PrP and amyloid-β oligomers (Aβo). We show that PSCMA can induce reentrant LLPS of PrP and lower the saturation concentration () of PrP by 100-fold.

Repetitive Mild Closed-Head Injury Induced Synapse Loss and Increased Local BOLD-fMRI Signal Homogeneity.

Repeated mild head injuries due to sports, or domestic violence and military service are increasingly linked to debilitating symptoms in the long term. Although symptoms may take decades to manifest, potentially treatable neurobiological alterations must begin shortly after injury. Better means to diagnose and treat traumatic brain injuries requires an improved understanding of the mechanisms underlying progression and means through which they can be measured.

Repetitive mild closed-head injury induced synapse loss and increased local BOLD-fMRI signal homogeneity.

Repeated mild head injuries due to sports, or domestic violence and military service are increasingly linked to debilitating symptoms in the long term. Although symptoms may take decades to manifest, potentially treatable neurobiological alterations must begin shortly after injury. Better means to diagnose and treat traumatic brain injuries, requires an improved understanding of the mechanisms underlying progression and means through which they can be measured.

Reduced progranulin increases tau and α-synuclein inclusions and alters mouse tauopathy phenotypes via glucocerebrosidase.

Comorbid proteinopathies are observed in many neurodegenerative disorders including Alzheimer's disease (AD), increase with age, and influence clinical outcomes, yet the mechanisms remain ill-defined. Here, we show that reduction of progranulin (PGRN), a lysosomal protein associated with TDP-43 proteinopathy, also increases tau inclusions, causes concomitant accumulation of α-synuclein and worsens mortality and disinhibited behaviors in tauopathy mice. The increased inclusions paradoxically protect against spatial memory deficit and hippocampal neurodegeneration.

Aging-Dependent Loss of Connectivity in Alzheimer's Model Mice with Rescue by mGluR5 Modulator.

Amyloid accumulation in Alzheimer's disease (AD) is associated with synaptic damage and altered connectivity in brain networks. While measures of amyloid accumulation and biochemical changes in mouse models have utility for translational studies of certain therapeutics, preclinical analysis of altered brain connectivity using clinically relevant fMRI measures has not been well developed for agents intended to improve neural networks. Here, we conduct a longitudinal study in a double knock-in mouse model for AD ( ), monitoring brain connectivity by means of resting-state fMRI.

Neuronal transcriptome, tau and synapse loss in Alzheimer's knock-in mice require prion protein.

Background: Progression of Alzheimer's disease leads to synapse loss, neural network dysfunction and cognitive failure. Accumulation of protein aggregates and brain immune activation have triggering roles in synaptic failure but the neuronal mechanisms underlying synapse loss are unclear. On the neuronal surface, cellular prion protein (PrP) is known to be a high-affinity binding site for Amyloid-β oligomers (Aβo).

Development of neural repair therapy for chronic spinal cord trauma: soluble Nogo receptor decoy from discovery to clinical trial.

Purpose Of Review: After traumatic spinal cord injury (SCI), neurological deficits persist due to the disconnection of surviving neurons. While repair of connectivity may restore function, no medical therapy exists today.This review traces the development of the neural repair-based therapeutic AXER-204 from animal studies to the recent clinical trial for chronic cervical SCI.

Amino-terminal proteolytic fragment of the axon growth inhibitor Nogo-A (Rtn4A) is upregulated by injury and promotes axon regeneration.

After adult mammalian central nervous system injury, axon regeneration is extremely limited or absent, resulting in persistent neurological deficits. Axon regeneration failure is due in part to the presence of inhibitory proteins, including NogoA (Rtn4A), from which two inhibitory domains have been defined. When these inhibitory domains are deleted, but an amino-terminal domain is still expressed in a gene trap line, mice show axon regeneration and enhanced recovery from injury.

Soluble Nogo-Receptor-Fc decoy (AXER-204) in patients with chronic cervical spinal cord injury in the USA: a first-in-human and randomised clinical trial.

Background: Spinal cord injury (SCI) causes neural disconnection and persistent neurological deficits, so axon sprouting and plasticity might promote recovery. Soluble Nogo-Receptor-Fc decoy (AXER-204) blocks inhibitors of axon growth and promotes recovery of motor function after SCI in animals. This first-in-human and randomised trial sought to determine primarily the safety and pharmacokinetics of AXER-204 in individuals with chronic SCI, and secondarily its effect on recovery.

TMEM106B Puncta Is Increased in Multiple Sclerosis Plaques, and Reduced Protein in Mice Results in Delayed Lipid Clearance Following CNS Injury.

During inflammatory, demyelinating diseases such as multiple sclerosis (MS), inflammation and axonal damage are prevalent early in the course. Axonal damage includes swelling, defects in transport, and failure to clear damaged intracellular proteins, all of which affect recovery and compromise neuronal integrity. The clearance of damaged cell components is important to maintain normal turnover and restore homeostasis.

Nogo receptor-Fc delivered by haematopoietic cells enhances neurorepair in a multiple sclerosis model.

Nogo receptor 1 is the high affinity receptor for the potent myelin-associated inhibitory factors that make up part of the inflammatory extracellular milieu during experimental autoimmune encephalomyelitis. Signalling through the Nogo receptor 1 complex has been shown to be associated with axonal degeneration in an animal model of multiple sclerosis, and neuronal deletion of this receptor homologue, in a disease specific manner, is associated with preserving axons even in the context of neuroinflammation. The local delivery of Nogo receptor(1-310)-Fc, a therapeutic fusion protein, has been successfully applied as a treatment in animal models of spinal cord injury and glaucoma.

Single-cell transcriptomic atlas of Alzheimer's disease middle temporal gyrus reveals region, cell type and sex specificity of gene expression with novel genetic risk for MERTK in female.

Alzheimer's disease, the most common age-related neurodegenerative disease, is closely associated with both amyloid-ß plaque and neuroinflammation. Two thirds of Alzheimer's disease patients are females and they have a higher disease risk. Moreover, women with Alzheimer's disease have more extensive brain histological changes than men along with more severe cognitive symptoms and neurodegeneration.

Decreased synaptic vesicle glycoprotein 2A binding in a rodent model of familial Alzheimer's disease detected by [F]SDM-16.

Introduction: Synapse loss is one of the hallmarks of Alzheimer's disease (AD) and is associated with cognitive decline. In this study, we tested [F]SDM-16, a novel metabolically stable SV2A PET imaging probe, in the transgenic APPswe/PS1dE9 (APP/PS1) mouse model of AD and age-matched wild-type (WT) mice at 12 months of age.

Methods: Based on previous preclinical PET imaging studies using [C]UCB-J and [F]SynVesT-1 in the same strain animals, we used the simplified reference tissue model (SRTM), with brain stem as the pseudo reference region to calculate distribution volume ratios (DVRs).