Browsing by Author "Zhou, Ting"
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Item Open Access An Antimicrobial Peptide and Its Neuronal Receptor Regulate Dendrite Degeneration in Aging and Infection.(Neuron, 2018-01-03) E, Lezi; Zhou, Ting; Koh, Sehwon; Chuang, Marian; Sharma, Ruchira; Pujol, Nathalie; Chisholm, Andrew D; Eroglu, Cagla; Matsunami, Hiroaki; Yan, DongInfections have been identified as possible risk factors for aging-related neurodegenerative diseases, but it remains unclear whether infection-related immune molecules have a causative role in neurodegeneration during aging. Here, we reveal an unexpected role of an epidermally expressed antimicrobial peptide, NLP-29 (neuropeptide-like protein 29), in triggering aging-associated dendrite degeneration in C. elegans. The age-dependent increase of nlp-29 expression is regulated by the epidermal tir-1/SARM-pmk-1/p38 MAPK innate immunity pathway. We further identify an orphan G protein-coupled receptor NPR-12 (neuropeptide receptor 12) acting in neurons as a receptor for NLP-29 and demonstrate that the autophagic machinery is involved cell autonomously downstream of NPR-12 to transduce degeneration signals. Finally, we show that fungal infections cause dendrite degeneration using a similar mechanism as in aging, through NLP-29, NPR-12, and autophagy. Our findings reveal an important causative role of antimicrobial peptides, their neuronal receptors, and the autophagy pathway in aging- and infection-associated dendrite degeneration.Item Open Access The Epstein-Barr virus (EBV)-induced tumor suppressor microRNA MiR-34a is growth promoting in EBV-infected B cells.(Journal of virology, 2012-06) Forte, Eleonora; Salinas, Raul E; Chang, Christina; Zhou, Ting; Linnstaedt, Sarah D; Gottwein, Eva; Jacobs, Cassandra; Jima, Dereje; Li, Qi-Jing; Dave, Sandeep S; Luftig, Micah AEpstein-Barr virus (EBV) infection of primary human B cells drives their indefinite proliferation into lymphoblastoid cell lines (LCLs). B cell immortalization depends on expression of viral latency genes, as well as the regulation of host genes. Given the important role of microRNAs (miRNAs) in regulating fundamental cellular processes, in this study, we assayed changes in host miRNA expression during primary B cell infection by EBV. We observed and validated dynamic changes in several miRNAs from early proliferation through immortalization; oncogenic miRNAs were induced, and tumor suppressor miRNAs were largely repressed. However, one miRNA described as a p53-targeted tumor suppressor, miR-34a, was strongly induced by EBV infection and expressed in many EBV and Kaposi's sarcoma-associated herpesvirus (KSHV)-infected lymphoma cell lines. EBV latent membrane protein 1 (LMP1) was sufficient to induce miR-34a requiring downstream NF-κB activation but independent of functional p53. Furthermore, overexpression of miR-34a was not toxic in several B lymphoma cell lines, and inhibition of miR-34a impaired the growth of EBV-transformed cells. This study identifies a progrowth role for a tumor-suppressive miRNA in oncogenic-virus-mediated transformation, highlighting the importance of studying miRNA function in different cellular contexts.Item Open Access The missense of smell: functional variability in the human odorant receptor repertoire.(Nat Neurosci, 2014-01) Mainland, Joel D; Keller, Andreas; Li, Yun R; Zhou, Ting; Trimmer, Casey; Snyder, Lindsey L; Moberly, Andrew H; Adipietro, Kaylin A; Liu, Wen Ling L; Zhuang, Hanyi; Zhan, Senmiao; Lee, Somin S; Lin, Abigail; Matsunami, HiroakiHumans have ~400 intact odorant receptors, but each individual has a unique set of genetic variations that lead to variation in olfactory perception. We used a heterologous assay to determine how often genetic polymorphisms in odorant receptors alter receptor function. We identified agonists for 18 odorant receptors and found that 63% of the odorant receptors we examined had polymorphisms that altered in vitro function. On average, two individuals have functional differences at over 30% of their odorant receptor alleles. To show that these in vitro results are relevant to olfactory perception, we verified that variations in OR10G4 genotype explain over 15% of the observed variation in perceived intensity and over 10% of the observed variation in perceived valence for the high-affinity in vitro agonist guaiacol but do not explain phenotype variation for the lower-affinity agonists vanillin and ethyl vanillin.Item Open Access Transcriptome and Functional Analysis of Carotid Body Glomus Cells(2016) Zhou, TingThe carotid body (CB) is a major arterial chemoreceptor containing glomus cells that are activated by changes in arterial blood contents including oxygen. Despite significant advancement in the characterization of their physiological properties, our understanding on the underlying molecular machinery and signaling pathway in CB glomus cells is still limited.
To overcome these limitations, in chapter 1, I demonstrated the first transcriptome profile of CB glomus cells using single cell sequencing technology, which allowed us to uncover a set of abundantly expressed genes, including novel glomus cell-specific transcripts. These results revealed involvement of G protein-coupled receptor (GPCR) signaling pathway, various types of ion channels, as well as atypical mitochondrial subunits in CB function. I also identified ligands for the mostly highly expressed GPCR (Olfr78) in CB glomus cells and examined this receptor’s role in CB mediated hypoxic ventilatory response.
Current knowledge of CB suggest glomus cells rely on unusual mitochondria for their sensitivity to hypoxia. I previously identified the atypical mitochondrial subunit Ndufa4l2 as a highly over-represented gene in CB glomus cells. In chapter 2, to investigate the functional significance of Ndufa4l2 in CB function, I phenotyped both Ndufa4l2 knockout mice and mice with conditional Ndufa4l2 deletion in CB glomus cells. I found that Ndufa4l2 is essential to the establishment of regular breathing after birth. Ablating Ndufa4l2 in postnatal CB glomus cells resulted in defective CB sensitivity to hypoxia as well as CB mediated hypoxic ventilatory response. Together, our data showed that Ndufa4l2 is critical to respiratory control and the oxygen sensitivity of CB glomus cells.