An experimental model of neurodegenerative disease based on porcine hemagglutinating encephalomyelitis virus-related lysosomal abnormalities

2020 ◽  
Author(s):  
Yungang Lan ◽  
Zi Li ◽  
Zhenzhen Wang ◽  
Xinran Wang ◽  
Gaili Wang ◽  
...  
Keyword(s):  
Neurodegenerative Diseases ◽  
Neuronal Ceroid Lipofuscinosis ◽  
Disease Model ◽  
Experimental Models ◽  
Neural Cells ◽  
Specific Mechanism ◽  
Encephalomyelitis Virus ◽  
Infected Cells ◽  
First Time ◽  
Porcine Hemagglutinating Encephalomyelitis Virus

Abstract Advances in experimental models for neurodegenerative diseases have enhanced the understanding of its molecular pathogenesis and begun to revealed promising therapeutic avenues. Lysosomes are involved in pathogenesis of a variety of neurodegenerative diseases and play a large role in neurodegenerative disorders caused by virus infection. However, whether virus-infected cells or animals can be used as experimental models of neurodegeneration in humans based on virus-related lysosomal dysfunction remain unclear. Porcine hemagglutinating encephalomyelitis virus (PHEV) displays neurotropism in mice and neural cells are its targets for viral progression. PHEV infection may be a risk factor for neurodegenerative diseases. Our findings demonstrated for the first time that PHEV infection can lead to lysosome disorders and showed that the specific mechanism of lysosome dysfunction is related to PGRN expression deficiency and indicated similar pathogenesis compared to human neurodegenerative diseases such as neuronal ceroid lipofuscinosis (NCL) and frontotemporal lobar degeneration (FTLD) upon PHEV infection. Trehalose can also increase progranulin (PGRN) expression and rescue abnormalities in lysosomal structure in PHEV-infected cells. In conclusion, these results suggest that PHEV may serve as a disease model for studying the pathogenic mechanisms and prevention of other degenerative diseases.

scholarly journals Microglial Progranulin: Involvement in Alzheimer’s Disease and Neurodegenerative Diseases

Cells ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 230 ◽  
Author(s):  
Anarmaa Mendsaikhan ◽  
Ikuo Tooyama ◽  
Douglas G. Walker
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Neurodegenerative Diseases ◽  
Neuronal Ceroid Lipofuscinosis ◽  
Experimental Models ◽  
Lysosomal Storage ◽  
Cellular Functions ◽  
New Treatments ◽  
Regulatory Properties ◽  
Microglial Inflammation

Neurodegenerative diseases such as Alzheimer’s disease have proven resistant to new treatments. The complexity of neurodegenerative disease mechanisms can be highlighted by accumulating evidence for a role for a growth factor, progranulin (PGRN). PGRN is a glycoprotein encoded by the GRN/Grn gene with multiple cellular functions, including neurotrophic, anti-inflammatory and lysosome regulatory properties. Mutations in the GRN gene can lead to frontotemporal lobar degeneration (FTLD), a cause of dementia, and neuronal ceroid lipofuscinosis (NCL), a lysosomal storage disease. Both diseases are associated with loss of PGRN function resulting, amongst other features, in enhanced microglial neuroinflammation and lysosomal dysfunction. PGRN has also been implicated in Alzheimer’s disease (AD). Unlike FTLD, increased expression of PGRN occurs in brains of human AD cases and AD model mice, particularly in activated microglia. How microglial PGRN might be involved in AD and other neurodegenerative diseases will be discussed. A unifying feature of PGRN in diseases might be its modulation of lysosomal function in neurons and microglia. Many experimental models have focused on consequences of PGRN gene deletion: however, possible outcomes of increasing PGRN on microglial inflammation and neurodegeneration will be discussed. We will also suggest directions for future studies on PGRN and microglia in relation to neurodegenerative diseases.

scholarly journals Porcine Hemagglutinating Encephalomyelitis Virus Enters Neuro-2a Cells via Clathrin-Mediated Endocytosis in a Rab5-, Cholesterol-, and pH-Dependent Manner

2017 ◽  
Vol 91 (23) ◽  
Author(s):  
Zi Li ◽  
Kui Zhao ◽  
Yungang Lan ◽  
Xiaoling Lv ◽  
Shiyu Hu ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Viral Entry ◽  
Intracellular Trafficking ◽  
Neural Cells ◽  
Dependent Manner ◽  
Encephalomyelitis Virus ◽  
The Central Nervous System ◽  
Ph Dependent ◽  
Porcine Hemagglutinating Encephalomyelitis Virus

ABSTRACT Porcine hemagglutinating encephalomyelitis virus (PHEV) is a highly neurovirulent coronavirus that invades the central nervous system (CNS) in piglets. Although important progress has been made toward understanding the biology of PHEV, many aspects of its life cycle remain obscure. Here we dissected the molecular mechanism underlying cellular entry and intracellular trafficking of PHEV in mouse neuroblastoma (Neuro-2a) cells. We first performed a thin-section transmission electron microscopy (TEM) assay to characterize the kinetics of PHEV, and we found that viral entry and transfer occur via membranous coating-mediated endo- and exocytosis. To verify the roles of distinct endocytic pathways, systematic approaches were used, including pharmacological inhibition, RNA interference, confocal microscopy analysis, use of fluorescently labeled virus particles, and overexpression of a dominant negative (DN) mutant. Quantification of infected cells showed that PHEV enters cells by clathrin-mediated endocytosis (CME) and that low pH, dynamin, cholesterol, and Eps15 are indispensably involved in this process. Intriguingly, PHEV invasion leads to rapid actin rearrangement, suggesting that the intactness and dynamics of the actin cytoskeleton are positively correlated with viral endocytosis. We next investigated the trafficking of internalized PHEV and found that Rab5- and Rab7-dependent pathways are required for the initiation of a productive infection. Furthermore, a GTPase activation assay suggested that endogenous Rab5 is activated by PHEV and is crucial for viral progression. Our findings demonstrate that PHEV hijacks the CME and endosomal system of the host to enter and traffic within neural cells, providing new insights into PHEV pathogenesis and guidance for antiviral drug design. IMPORTANCE Porcine hemagglutinating encephalomyelitis virus (PHEV), a nonsegmented, positive-sense, single-stranded RNA coronavirus, invades the central nervous system (CNS) and causes neurological dysfunction. Neural cells are its targets for viral progression. However, the detailed mechanism underlying PHEV entry and trafficking remains unknown. PHEV is the etiological agent of porcine hemagglutinating encephalomyelitis, which is an acute and highly contagious disease that causes numerous deaths in suckling piglets and enormous economic losses in China. Understanding the viral entry pathway will not only advance our knowledge of PHEV infection and pathogenesis but also open new approaches to the development of novel therapeutic strategies. Therefore, we employed systematic approaches to dissect the internalization and intracellular trafficking mechanism of PHEV in Neuro-2a cells. This is the first report to describe the process of PHEV entry into nerve cells via clathrin-mediated endocytosis in a dynamin-, cholesterol-, and pH-dependent manner that requires Rab5 and Rab7.

scholarly journals The PERK/PKR-eIF2α pathway negatively regulates porcine hemagglutinating encephalomyelitis virus replication by attenuating global protein translation and facilitating stress granule formation

2021 ◽  
Author(s):  
Junchao Shi ◽  
Zi Li ◽  
Rongyi Xu ◽  
Jing Zhang ◽  
Qianyu Zhou ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Severe Acute Respiratory Syndrome ◽  
Protein Translation ◽  
Stress Granule ◽  
Innate Response ◽  
Encephalomyelitis Virus ◽  
Infected Cells ◽  
Porcine Hemagglutinating Encephalomyelitis Virus

The replication of coronaviruses, including severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV) and the recently emerged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is closely associated with the endoplasmic reticulum (ER) of infected cells. The unfolded protein response (UPR), which is mediated by ER stress (ERS), is a typical outcome in coronavirus-infected cells and is closely associated with the characteristics of coronaviruses. However, the interaction between virus-induced ERS and coronavirus replication is poorly understood. Here, we demonstrated that infection with the betacoronavirus porcine hemagglutinating encephalomyelitis virus (PHEV) induced ERS and triggered all three branches of the UPR signaling pathway both in vitro and in vivo. In addition, ERS suppressed PHEV replication in mouse neuro-2a (N2a) cells primarily by activating the protein kinase R-like ER kinase (PERK)-eukaryotic initiation factor 2α (eIF2α) axis of the UPR. Moreover, another eIF2α phosphorylation kinase, IFN-induced double-stranded RNA-dependent protein kinase (PKR), was also activated and acted cooperatively with PERK to decrease PHEV replication. Furthermore, we demonstrated that the PERK/PKR-eIF2α pathways negatively regulated PHEV replication by attenuating global protein translation. Phosphorylated eIF2α also promoted the formation of stress granule (SG), which in turn repressed PHEV replication. In summary, our study presents a vital aspect of the host innate response to invading pathogens and reveals attractive host targets (e.g., PERK, PKR and eIF2α) for antiviral drugs. IMPORTANCE Coronavirus diseases are caused by different coronaviruses of importance in humans and animals, and specific treatments are extremely limited. ERS, which can activate the UPR to modulate viral replication and the host innate response, is a frequent occurrence in coronavirus-infected cells. PHEV, a neurotropic β-coronavirus, causes nerve cell damage, which accounts for the high mortality rates in suckling piglets. However, it remains incompletely understood whether the highly developed ER in nerve cells plays an antiviral role in ERS and how ERS regulates viral proliferation. In this study, we found that PHEV infection induced ERS and activated the UPR both in vitro and in vivo and that the activated PERK/PKR-eIF2α axis inhibited PHEV replication through attenuating global protein translation and promoting SG formation. A better understanding of coronavirus-induced ERS and UPR activation may reveal the pathogenic mechanism of coronavirus and facilitate the development of new treatment strategies for these diseases.

scholarly journals Activation of pro-apoptotic cells, reactive astrogliosis and hyperphosphorylation of tau protein in trimethyltin-induced hippocampal injury in rats

2020 ◽  
Vol 9 (2) ◽  
pp. 1782-1788
Author(s):  
A.A. Okesina ◽  
M.S. Ajao ◽  
M.O. Buhari ◽  
A.M. Afodun ◽  
K.B. Okesina ◽  
...  
Keyword(s):  
Neurodegenerative Diseases ◽  
Tau Protein ◽  
Genetic Factors ◽  
Disease Model ◽  
Amyloid Plaques ◽  
Control Group ◽  
Neural Cells ◽  
Reactive Astrogliosis ◽  
Parkinson’S Diseases ◽  
Male Wistar Rats

Neurodegenerative diseases cause neural cells to lose both the functional and sensory abilities as a result of genetic factors, proteopathies and mitochondrial dysfunction. Neurodegeneration forms the basis of most neurodegenerative disorders for example Alzheimer’s disease, Huntington’s diseases, and Parkinson’s diseases. The mechanism that underlines the process of neurodegeneration is not well understood. Understanding the process and mechanism involved in neurodegeneration might offer a better therapeutic approach to positively manage cases of neurodegenerative diseases. Therefore, this study’s target was to create an animal model to study neurodegeneration. Sixteen adult male Wistar rats were used in the study and divided into two groups. Control (0.2 mL of normal saline (NS)), and trimethyltin-treated (TMT, 8 mg/kg stat dose only). These animals underwent perfusion with 4% paraformaldehyde, brain excision and analysis of p53 antigen, GFAP and Bielshowsky on these tissues. The results showed that animals in the control group showed presence of activated p53 antigen, reactive astrogliosis, neurofibrillary tangles, and amyloid plaques within the cytoplasm of the hippocampal cells. Cornus Ammonis (CA2) and (CA3) showed more of the trimethylrtin injury than CA1 and CA4. This study thus revealed that, intra-peritoneal administration of single dose of 8mg/kg of trimethyltin can offer an attractive disease model to study some neurodegenerative diseases. Keywords: p53 antigen, Bielshowsky, Glia fibrillary acidic protein, Trimethyltin, Hippocampus,

scholarly journals Emerging hiPSC Models for Drug Discovery in Neurodegenerative Diseases

2021 ◽  
Vol 22 (15) ◽  
pp. 8196
Author(s):  
Dorit Trudler ◽  
Swagata Ghatak ◽  
Stuart A. Lipton
Keyword(s):  
Drug Discovery ◽  
Animal Models ◽  
Neurodegenerative Diseases ◽  
Disease Modeling ◽  
Induced Pluripotent Stem Cell ◽  
Neural Function ◽  
Neural Cells ◽  
Human Samples ◽  
Healthy Donors ◽  
Induced Pluripotent

Neurodegenerative diseases affect millions of people worldwide and are characterized by the chronic and progressive deterioration of neural function. Neurodegenerative diseases, such as Alzheimer’s disease (AD), Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS), and Huntington’s disease (HD), represent a huge social and economic burden due to increasing prevalence in our aging society, severity of symptoms, and lack of effective disease-modifying therapies. This lack of effective treatments is partly due to a lack of reliable models. Modeling neurodegenerative diseases is difficult because of poor access to human samples (restricted in general to postmortem tissue) and limited knowledge of disease mechanisms in a human context. Animal models play an instrumental role in understanding these diseases but fail to comprehensively represent the full extent of disease due to critical differences between humans and other mammals. The advent of human-induced pluripotent stem cell (hiPSC) technology presents an advantageous system that complements animal models of neurodegenerative diseases. Coupled with advances in gene-editing technologies, hiPSC-derived neural cells from patients and healthy donors now allow disease modeling using human samples that can be used for drug discovery.

scholarly journals Prion Diseases: A Unique Transmissible Agent or a Model for Neurodegenerative Diseases?

Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 207
Author(s):  
Diane L. Ritchie ◽  
Marcelo A. Barria
Keyword(s):  
Public Health ◽  
Neurodegenerative Diseases ◽  
Prion Protein ◽  
Neurodegenerative Disorders ◽  
Prion Diseases ◽  
Experimental Models ◽  
Misfolded Proteins ◽  
Current Evidence

The accumulation and propagation in the brain of misfolded proteins is a pathological hallmark shared by many neurodegenerative diseases such as Alzheimer’s disease (Aβ and tau), Parkinson’s disease (α-synuclein), and prion disease (prion protein). Currently, there is no epidemiological evidence to suggest that neurodegenerative disorders are infectious, apart from prion diseases. However, there is an increasing body of evidence from experimental models to suggest that other pathogenic proteins such as Aβ and tau can propagate in vivo and in vitro in a prion-like mechanism, inducing the formation of misfolded protein aggregates such as amyloid plaques and neurofibrillary tangles. Such similarities have raised concerns that misfolded proteins, other than the prion protein, could potentially transmit from person-to-person as rare events after lengthy incubation periods. Such concerns have been heightened following a number of recent reports of the possible inadvertent transmission of Aβ pathology via medical and surgical procedures. This review will provide a historical perspective on the unique transmissible nature of prion diseases, examining their impact on public health and the ongoing concerns raised by this rare group of disorders. Additionally, this review will provide an insight into current evidence supporting the potential transmissibility of other pathogenic proteins associated with more common neurodegenerative disorders and the potential implications for public health.

Abstract 260: Autophagy And Necrosis Underlie Polyglutamine Amyloid Oligomer Induced Heart Failure.

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Scott Pattison ◽  
Atsushi Sanbe ◽  
Raisa Klevitsky ◽  
Hanna Osinska ◽  
Jeffrey Robbins
Keyword(s):  
Heart Failure ◽  
Neurodegenerative Diseases ◽  
Pathogenic Mechanism ◽  
Positive Staining ◽  
Neural Cells ◽  
Conformational Structure ◽  
Human Heart Failure ◽  
Specific Expression ◽  
Amyloid Oligomers ◽  
Amyloid Oligomer

Introduction: Amyloid oligomers, the entities believed to cause toxicity in many neurodegenerative diseases, have been observed in mouse and human heart failure samples. Amyloid oligomers are a diverse group of proteins that differ in sequence, but share a common conformational structure, and may impart a shared pathogenic mechanism. The purpose of this study was to test the hypothesis that expression and accumulation of amyloid oligomers are cytotoxic and sufficient to directly cause heart failure. Polyglutamine (PQ) repeats (>50) are known to form amyloid oligomers and induce toxicity in neural cells, causing Huntington′s and other neurodegenerative diseases, while shorter PQ peptides are benign. Hypothesis: Cardiomyocyte-autonomous expression of an exogenous PQ amyloid oligomer will be toxic to cardiomyocytes and result in heart failure. Methods: Transgenic mice were created with cardiomyocyte-specific expression of an amyloid oligomer forming peptide of 83 PQ repeats (PQ83) or a non-amyloid forming peptide of 19 PQ repeats (PQ19) as a non-pathological control. Both constructs were HA tagged. Results: A PQ83 line with relatively low levels of expression was generated, along with a PQ19 line that expressed at approximately 9-fold the levels observed in the PQ83 line. Hearts expressing PQ83 develop cardiac dysfunction and dilation by 5 months and exhibit 100% mortality by 8 months of age, whereas PQ19 mice have normal cardiac function, morphology and lifespan. PQ83 protein accumulates in cardiomyocytes as SDS-insoluble aggresomes with amyloid oligomer-positive staining. PQ83 hearts exhibited no signs of apoptosis. Ultrastructural analysis revealed that PQ83 hearts undergo autophagy, as evidenced by increased autophagosomal and lysosomal content. PQ83 hearts also show characteristics of necrotic death, including infiltration of inflammatory cells, cardiomyocyte vacuolization and increased staining for the membrane attack complex that causes sarcolemmal permeabilization. The data confirm the hypothesis that expression of an exogenous amyloid oligomer is toxic to cardiomyocytes and is sufficient to cause heart failure. The pathogenic mechanism appears to lead to cardiomyocyte death through autophagy and necrosis.

scholarly journals The evidence of porcine hemagglutinating encephalomyelitis virus induced nonsuppurative encephalitis as the cause of death in piglets

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2443 ◽  
Author(s):  
Zi Li ◽  
Wenqi He ◽  
Yungang Lan ◽  
Kui Zhao ◽  
Xiaoling Lv ◽  
...  
Keyword(s):  
Nervous System ◽  
Cause Of Death ◽  
Viral Infections ◽  
Vaccine Development ◽  
Wild Strain ◽  
Effective Vaccine ◽  
Symptoms Of Depression ◽  
Encephalomyelitis Virus ◽  
Cns Dysfunction ◽  
Porcine Hemagglutinating Encephalomyelitis Virus

An acute outbreak of porcine hemagglutinating encephalomyelitis virus (PHEV) infection in piglets, characterized with neurological symptoms, vomiting, diarrhea, and wasting, occurred in China. Coronavirus-like particles were observed in the homogenized tissue suspensions of the brain of dead piglets by electron microscopy, and a wild PHEV strain was isolated, characterized, and designated as PHEV-CC14. Histopathologic examinations of the dead piglets showed characteristics of non-suppurative encephalitis, and some neurons in the cerebral cortex were degenerated and necrotic, and neuronophagia. Similarly, mice inoculated with PHEV-CC14 were found to have central nervous system (CNS) dysfunction, with symptoms of depression, arched waists, standing and vellicating front claws. Furthmore, PHEV-positive labeling of neurons in cortices of dead piglets and infected mice supported the viral infections of the nervous system. Then, the major structural genes of PHEV-CC14 were sequenced and phylogenetically analyzed, and the strain shared 95%–99.2% nt identity with the other PHEV strains available in GenBank. Phylogenetic analysis clearly proved that the wild strain clustered into a subclass with a HEV-JT06 strain. These findings suggested that the virus had a strong tropism for CNS, in this way, inducing nonsuppurative encephalitis as the cause of death in piglets. Simultaneously, the predicted risk of widespread transmission showed a certain variation among the PHEV strains currently circulating around the world. Above all, the information presented in this study can not only provide good reference for the experimental diagnosis of PHEV infection for pig breeding, but also promote its new effective vaccine development.

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