Targeting Extracellular Cyclophilin A Reduces Neuroinflammation and Extends Survival in a Mouse Model of Amyotrophic Lateral Sclerosis

Background Histamine is an immune modulator, neuroprotective, and remyelinating agent, beneficially acting on skeletal muscles and promoting anti‐inflammatory features in amyotrophic lateral sclerosis (ALS) microglia. Drugs potentiating the endogenous release of histamine are in trial for neurological diseases, with a role not systematically investigated in ALS. Here, we examine histamine pathway associations in ALS patients and the efficacy of a histamine‐mediated therapeutic strategy in ALS mice. Methods We adopted an integrative multi‐omics approach combining gene expression profiles, copy number variants, and single nucleotide polymorphisms of ALS patients. We treated superoxide dismutase 1 (SOD1)‐G93A mice that recapitulate key ALS features, with the brain‐permeable histamine precursor histidine in the symptomatic phase of the disease and analysed the rescue from disease pathological signs. We examined the action of histamine in cultured SOD1‐G93A motor neuron‐like cells. Results We identified 13 histamine‐related genes deregulated in the spinal cord of two ALS patient subgroups, among which genes involved in histamine metabolism, receptors, transport, and secretion. Some histamine‐related genes overlapped with genomic regions disrupted by DNA copy number and with ALS‐linked pathogenic variants. Histidine treatment in SOD1‐G93A mice proved broad efficacy in ameliorating ALS features, among which most importantly lifespan, motor performance, microgliosis, muscle atrophy, and motor neurons survival in vivo and in vitro . Conclusions Our gene set/pathway enrichment analyses and preclinical studies started at the onset of symptoms establish that histamine‐related genes are modifiers in ALS, supporting their role as candidate biomarkers and therapeutic targets. We disclose a novel important role for histamine in the characterization of the multi‐gene network responsible for ALS and, furthermore, in the drug development process.

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“…Mice were injected i.p. every 48 h from disease onset (110 days,) until 150 days of age or terminal stage.…”

Section: Methodsmentioning

confidence: 99%

Histaminergic transmission slows progression of amyotrophic lateral sclerosis

Apolloni

Amadio

Fabbrizio

et al. 2019

J cachexia sarcopenia muscle

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“…For western blot (WB), samples (15 µg) were separated in 12% SDS-polyacrylamide gels and transferred to polyvinylidene difluoride membranes (Millipore), as described previously (Lauranzano et al, 2015). For dot blot, proteins (3 µg) were loaded directly onto nitrocellulose Trans-blot transfer membranes (0.45 µm; Bio-Rad),depositing each sample on the membrane by vacuum filtration, as described previously (Basso et al, 2009;Filareti et al, 2017;Massignan et al, 2007;Nardo et al, 2011;Pasetto et al, 2017). WB and dot blot membranes were blocked with 3% (w/v) BSA (Sigma-Aldrich) and 0.1% (v/v) Tween 20 in Tris-buffered saline, pH 7.5, and incubated with primary antibodies according to the manufacturer's protocol and then with peroxidaseconjugated secondary antibodies (GE Healthcare).…”

Section: Immunoblottingmentioning

confidence: 99%

“…In PPIA-/-mice, we found astrogliosis that increased with age, but no microglial activation. We know that PPIA itself has a role in microglial activation and the neuroinflammatory response by activating the CD147/EMMPRIM receptor, therefore PPIA-/-mice are not suitable to investigate this feature of the pathology (Bouybayoune et al, 2019;Pasetto et al, 2017) .…”

Section: Ftld-tdp Is the Most Common Neuropathologic Type Of Ftld Andmentioning

confidence: 99%

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Defective cyclophilin A induces TDP-43 proteinopathy: implications for amyotrophic lateral sclerosis and frontotemporal dementia

Pasetto

Grassano

Pozzi

et al. 2020

Preprint

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Frontotemporal dementia (FTD) is a common cause of early-onset dementia, characterized by frontotemporal lobar degeneration and considerable clinical, genetic and neuropathological heterogeneity. Several mouse models of FTD have been generated targeting genes with known pathogenic roles. However, each of these models recapitulates only certain aspects of the human disease. Cyclophilin A (PPIA) is a multifunctional protein abundantly expressed in the brain, with double-edged functions. Intracellularly, it is mainly protective as a foldase and molecular chaperone with scaffolding properties. Extracellularly, it behaves as a proinflammatory cytokine able to activate an aberrant inflammatory response. In a previous work, we found that PPIA governs TDP-43 functions and its deficiency exacerbates disease in a mouse model of ALS.Selective inhibition of extracellular PPIA rescued motor neurons and increased survival. To decipher PPIA's functions in the central nervous system, we planned a deep neuropathological and behavioral characterization of PPIA knock-out (PPIA-/-) mice throughout their lifespan. They develop a neurodegenerative disease that recapitulates key features of the behavioral variant of FTD associated with TDP-43 pathology. PPIA-/-mice present progressive hippocampal and cortex atrophy, with neuronal death and clear-cut TDP-43 pathology that include fragmentation, hyperphosphorylation, and cytoplasmic mislocalization/nuclear clearing. Mice exhibit increased disinhibition, defects in social behavior, but no memory and motor impairment. On a molecular level, our findings indicate that PPIA is involved in multiple genes and pathways that have a dominant protective effect in the brain, and is fundamental for TDP-43 function. Considering that an impaired interaction of TDP-43 with PPIA has been observed in ALS/FTD patients, the PPIA-/-mouse is a useful experimental model to investigate the mechanism at the basis of TDP-43 pathology and develop novel therapeutic approaches for ALS/FTD and possibly other TDP-43 proteinopathies.

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“…MMP2, MMP9), and ROS. Cyclophilin inhibitors block binding to CD147 and these and genetic Cyp A deletion have exerted potent anti-inflammatory activities in animal models of chronic asthma, arthritis, atherosclerosis, acute pulmonary embolism, stroke, thrombosis, aortic aneurysm, myocarditis, coronary artery disease, pulmonary arterial hypertension, amyotrophic lateral sclerosis, and other conditions [192,[204][205][206][207][208][209][210][211][212][213]. One of the activities of activated leukocytes is the oxidative burst in which NADPH oxidase generates ROS, and Cyp D inhibition has been shown to decrease oxidative burst and its consequences both in vitro and in vivo [214].…”

Section: Cyclophilin Involvement In Inflammationmentioning

confidence: 99%