Drug Discovery Today: Disease Models最新文献

Recent studies have brought renewed interest to the hypothesis that infection plays a role in the pathogenesis of Alzheimer’s disease (AD). In particular, herpesviruses such as herpes simplex virus-1 (HSV-1) and human herpesvirus-6 (HHV-6) have had an extensive history of association with AD. The interplay between viral infection and a variety of neurological diseases has long been an area of interest but proving causality has been elusive. Two recent studies, Readhead et al. (2018) and Eimer et al. (2018) have again renewed the debate concerning the role of pathogens (herpesviruses) in AD. In this review, we will briefly discuss the literature in support of a herpesvirus role in AD pathogenesis and try to bridge two main observations in AD research; the ability of Aβ to aggregate with pathogens, and the detection of herpesviruses in AD brain material compared to non-AD controls. While the data linking AD and human herpesviruses suggest that these pathogens may contribute to disease progression, further work is needed to determine the significance of these observations, if any, to the etiology of the disease.

Over the past decade there has been growing interest in elucidating the role of neuroinflammation in seizure generation. Several preclinical studies have revealed that infection with neurotropic viruses such as HHV-6 can trigger an inflammatory cascade involving infected CNS cells. These findings are corroborated by clinical studies, that have shown an association with HHV-6 infection and different epilepsy syndromes and have detected HHV-6 viral DNA in saliva, blood, CSF and resected epileptogenic tissue from children and adults with seizures and chronic epilepsy.

In this focused review we will analyze main clinical associations that link HHV-6 infection with seizures and proposed pathogenic mechanisms by which infection with HHV-6 can lead to a proinflammatory milieu contributing to seizure generation and in some instances later development of epilepsy.

Progressive multifocal leukoencephalopathy (PML), is an opportunistic brain infection that is caused by the JC virus. It usually occurs in patients with an underlying disease and therapies used to treat such diseases that inhibit normal immune system function. For example, multiple sclerosis patients treated with natalizumab have been identified at risk for PML. This serious adverse event has been very instructive in improving understanding of PML pathogenesis, biomarkers and patient management with this disease in recent years.

Epstein-Barr Virus (EBV) is a ubiquitous human herpesvirus that contributes to the etiology of diverse human cancers and auto-immune diseases. EBV establishes a relatively benign, long-term latent infection in over 90 percent of the adult population. Yet, it also increases risk for certain cancers and auto-immune disorders depending on complex viral, host, and environmental factors that are only partly understood. EBV latent infection is found predominantly in memory B cells, but the natural infection cycle and pathological aberrations enable EBV to infect numerous other cell types, including oral, nasopharyngeal, and gastric epithelia, B-, T-, and NK-lymphoid cells, myocytes, adipocytes, astrocytes, and neurons. EBV infected cells, free virus, and gene products can also be found in the CNS. In addition to the direct effects of EBV on infected cells and tissue, the effect of chronic EBV infection on the immune system is also thought to contribute to pathogenesis, especially auto-immune disease. Here, we review properties of EBV infection that may shed light on its potential pathogenic role in neurological disorders.

Neurocognitive disorders associated with HIV-1 infection affect more than half of persons living with HIV (PLWH) under retroviral therapy. Understanding the molecular mechanisms and the complex cellular network communication underlying neurological dysfunction is critical for the development of an effective therapy. As with other neurological disorders, challenges to studying HIV infection of the brain include limited access to clinical samples and proper reproducibility of the complexity of brain networks in cellular and animal models. This review focuses on cellular models used to investigate various aspects of neurological dysfunction associated with HIV infection.

The etiology and pathogenesis of MS is likely to involve multiple factors interacting with each other, and the role of infectious and viral agents is still under debate, however a consistent amount of studies suggests that some viruses are associated with the disease. The strongest documentation has come from the detection of viral nucleic acid or antigen or of an anti-viral antibody response in MS patients. A further step for the study of the mechanism viruses might be involved in can be made using in vitro and in vivo models. While in vitro models, based on glial and neural cell lines from various sources are widely used, in vivo animal models present challenges. Indeed neurotropic animal viruses are currently used to study demyelination in well-established models, but animal models of demyelination by human virus infection have only recently been developed, using animal gammaherpesviruses closely related to Epstein Barr virus (EBV), or using marmosets expressing the specific viral receptor for Human Herpesvirus 6 (HHV-6). The present review will illustrate the main potential mechanisms of MS pathogenesis possibly associated with viral infections and viruses currently used to study demyelination in animal models. Then the viruses most strongly linked with MS will be discussed, in the perspective that more than one virus might have a role, with varying degrees of interaction, contributing to MS heterogeneity.

Alkaptonuria (AKU) is a rare metabolic disease of historical and medical interest. Despite the identification of gene and protein defects leading to the accumulation of homogentisic acid (HGA), little is known on how HGA is transformed into an ochronotic pigment (the hallmark of the disease) leading to a range of clinical manifestations. Major obstacles in tackling the pathological features of AKU are the rarity of biological samples, the invasiveness of sampling techniques and the intrinsic difficulties of studying the pigmented tissues. This review provides an overview of the in vitro and ex vivo cell and tissue models that were recently developed and characterized to fill the above-mentioned gaps in the knowledge of AKU.

Rett syndrome (RTT) is a progressive neurodevelopmental disease, which affects almost exclusively the female gender (prevalence of about 1:10,000). RTT symptoms are usually characterized by loss of purposeful hand skills, mental retardation and motor impairment, resulting in a plethora of other systemic co-morbidities. Mutations in the methyl-CpG binding protein 2 gene (MECP2) are the main genetic cause of the disorder, however molecular mechanisms leading from MeCP2 defects to this complicated pathology still need to be clarified. To investigate this and other aspects of RTT, several experimental models have been generated that include animal models, and in vitro approaches. In this article we briefly summarized the main models used for RTT investigations, and special focus is given to the use of primary fibroblasts isolated from RTT patients, since they represent a reliable disease-in-a-dish model, which can help researcher to elucidate cellular and molecular mechanisms of this disease.

Since the initial description of Chediak-Higashi syndrome (CHS), over 75 years ago, several studies have been conducted to underscore the role of the lysosomal trafficking regulator (LYST) gene in the pathogenesis of disease. CHS is a rare autosomal recessive disorder, which is caused by biallelic mutations in the highly conserved LYST gene. The disease is characterized by partial oculocutaneous albinism, prolonged bleeding, immune and neurologic dysfunction, and risk for the development of hemophagocytic lympohistiocytosis (HLH). The presence of giant secretory granules in leukocytes is the classical diagnostic feature, which distinguishes CHS from closely related Griscelli and Hermansky-Pudlak syndromes. While the exact mechanism of the formation of the giant granules in CHS patients is not understood, dysregulation of LYST function in regulating lysosomal biogenesis has been proposed to play a role. In this review, we discuss the clinical characteristics of the disease and highlight the functional consequences of enlarged lysosomes and lysosome-related organelles (LROs) in CHS.