Department of Population Health Sciences

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https://hdl.handle.net/10919/24262

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Browsing Department of Population Health Sciences by Department "Biological Sciences"

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    Neurotrophic Factors NGF, GDNF and NTN Selectively Modulate HSV1 and HSV2 Lytic Infection and Reactivation in Primary Adult Sensory and Autonomic Neurons
    Yanez, Andy A.; Harrell, Telvin; Sriranganathan, Heather J.; Ives, Angela M.; Bertke, Andrea S. (MDPI, 2017-02-07)
    Herpes simplex viruses (HSV1 and HSV2) establish latency in peripheral ganglia after ocular or genital infection, and can reactivate to produce different patterns and frequencies of recurrent disease. Previous studies showed that nerve growth factor (NGF) maintains HSV1 latency in embryonic sympathetic and sensory neurons. However, adult sensory neurons are no longer dependent on NGF for survival, some populations cease expression of NGF receptors postnatally, and the viruses preferentially establish latency in different populations of sensory neurons responsive to other neurotrophic factors (NTFs). Thus, NGF may not maintain latency in adult sensory neurons. To identify NTFs important for maintaining HSV1 and HSV2 latency in adult neurons, we investigated acute and latently-infected primary adult sensory trigeminal (TG) and sympathetic superior cervical ganglia (SCG) after NTF removal. NGF and glial cell line-derived neurotrophic factor (GDNF) deprivation induced HSV1 reactivation in adult sympathetic neurons. In adult sensory neurons, however, neurturin (NTN) and GDNF deprivation induced HSV1 and HSV2 reactivation, respectively, while NGF deprivation had no effects. Furthermore, HSV1 and HSV2 preferentially reactivated from neurons expressing GFRα2 and GFRα1, the high affinity receptors for NTN and GDNF, respectively. Thus, NTN and GDNF play a critical role in selective maintenance of HSV1 and HSV2 latency in primary adult sensory neurons.
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    A rapid and high content assay that measures cyto-ID-stained autophagic compartments and estimates autophagy flux with potential clinical applications
    Guo, Sujuan; Liang, Yanping; Murphy, Susan F.; Huang, Angela; Shen, Haihong; Kelly, Deborah F.; Sobrado, Pablo; Sheng, Zhi (Taylor & Francis, 2015-03-01)
    The lack of a rapid and quantitative autophagy assay has substantially hindered the development and implementation of autophagy-targeting therapies for a variety of human diseases. To address this critical issue, we developed a novel autophagy assay using the newly developed Cyto-ID fluorescence dye. We first verified that the Cyto-ID dye specifically labels autophagic compartments with minimal staining of lysosomes and endosomes. We then developed a new Cyto-ID fluorescence spectrophotometric assay that makes it possible to estimate autophagy flux based on measurements of the Cyto-ID-stained autophagic compartments. By comparing to traditional autophagy approaches, we found that this assay yielded a more sensitive, yet less variable, quantification of the stained autophagic compartments and the estimate of autophagy flux. Furthermore, we tested the potential application of this autophagy assay in high throughput research by integrating it into an RNA interference (RNAi) screen and a small molecule screen. The RNAi screen revealed WNK2 and MAP3K6 as autophagy-modulating genes, both of which inhibited the MTOR pathway. Similarly, the small molecule screen identified sanguinarine and actinomycin D as potent autophagy inducers in leukemic cells. Moreover, we successfully detected autophagy responses to kinase inhibitors and chloroquine in normal or leukemic mice using this assay. Collectively, this new Cyto-ID fluorescence spectrophotometric assay provides a rapid, reliable quantification of autophagic compartments and estimation of autophagy flux with potential applications in developing autophagy-related therapies and as a test to monitor autophagy responses in patients being treated with autophagy-modulating drugs.