Yin Chen
Assistant Professor, BIO5 Institute
Associate Professor, Pharmacology and Toxicology
Primary Department
(520) 626-4715
Research Interest
Yin Chen, PhD. is an Assistant Professor in Pharmacology and Toxicology in the College of Pharmacy at UA. Dr. Chen’s research focus is on epithelial biology. He was a research faculty in University of California, Davis and an Assistant Investigator in Chemical Industry Institute of Toxicology (former CIIT and later Hamner Institute). His long-term research objective is to understand the dysfunction of airway epithelial mucosa in the pathogenesis of a variety of acute and chronic airway diseases. His current research programs are: a) understanding the molecular mechanisms underlying airway mucous cell development and mucous cell metaplasia in chronic diseases including cancer, COPD and asthma; (b) understanding the function and regulation of novel COPD associated genes and developing novel compounds to treat COPD; (c) understanding the impact of fungal exposure on airway innate immunity and its contribution to the development and exacerbation of asthma. Dr. Chen has more than 30 publications including peer-reviewed research articles, reviews and book chapters. He has served as the PI on one R01, two R21, one Flight Attendant Medical Institute (FAMRI) Innovative Clinical Award and one Arizona Biomedical Research Commission Award. He has also served as co-PI on two R01 and one P01 grants. He has built a long productive track record in studying airway mucus production and respiratory viral infection using primary airway epithelial cell model. He routinely cultivate and use primary epithelial cells from eye, salivary gland, airway surface and submucosal gland in different species (e.g. human, monkey, pig, rat and mouse) as our in vitro model to study mucin genes. The differentiated primary culture model demonstrates pseudostratified morphology, is composed of ciliated, non-ciliated, and goblet cells, and has a transepithelial barrier with high electro-resistance. He has also established in vivo exposure system to study the pulmonary effect of the exposure to particulates, pathogens and gases. Using this system, he has developed various airway disease models including CS-induced COPD model, ovalbumin-induced asthma model, fungal-induced asthma model and several infection models such as H1N1, rhinovirus, Aspergillus, and Alternaria.

Publications

Y., D., Reen, W. u., Chen, Y., Tarasova, N., & Chang, M. M. (2007). PMA stimulates MUC5B gene expression through an Sp1-based mechanism in airway epithelial cells. American Journal of Respiratory Cell and Molecular Biology, 37(5), 589-597.

PMID: 17600309;PMCID: PMC2048678;Abstract:

We previously showed that the MUC5B gene expression was elevated by phorbol 12-myristate 13-acetate (PMA) through an epidermal growth factor receptor-independent Ras/MEKK1/JNK and P38 signaling-based transcriptional mechanism. In the current study, we elucidated the molecular basis of this transcriptional regulation using promoter-reporter gene expression and chromatin immunoprecipitation (ChIP) assays with primary human bronchial epithelial cells that are cultured at the air-liquid interface. We have observed that PMA-induced MUC5B promoter activity is blocked by the Sp1-binding inhibitor, mithramycin A, in a dose-dependent manner. Deletion analysis with the MUC5B promoter construct demonstrated that both basal and PMA-induced promoter-reporter activities reside within the -222/-78 bp region relative to the transcriptional start site. NoShift transcriptional factor assays demonstrated that PMA stimulated Sp1 binding, but not STAT1 and c-Myc binding. Immunoprecipitation studies also verified the enhanced phosphorylation of Sp1 after PMA treatment. Site-directed mutagenesis and transfection studies demonstrated the involvement of Sp1-1 (-122/-114) and the Sp1-2 (-197/-186) cis elements in the basal and PMA-induced MUC5B promoter activity. The ChIP assay with anti-RNA polymerase II reconfirmed the PMA-induced MUC5B promoter activity by showing enhanced RNA polymerase II-DNA complex containing putative MUC5B Sp1-1, Sp1-2, or Sp1-3 sites. However, the ChIP assay using anti-Sp1 antibody demonstrated that the PMA-stimulated binding is only at Sp1-2. These results suggested an Sp1-based transcriptional mechanism with Sp1-1 as the regulator of basal MUC5B promoter activity and Sp1-2 as the regulator of PMA-induced MUC5B gene expression in the human airway epithelial cells.

Chen, Y., Zhao, Y. H., Kalaslavadi, T. B., Hamati, E., Nehrke, K., Le, A. D., Ann, D. K., & Reen, W. u. (2004). Genome-Wide Search and Identification of a Novel Gel-Forming Mucin MUC19/Muc19 in Glandular Tissues. American Journal of Respiratory Cell and Molecular Biology, 30(2), 155-165.

PMID: 12882755;Abstract:

Gel-forming mucins are major contributors to the viscoelastic properties of mucus secretion. Currently, four gel-forming mucin genes have been identified: MUC2, MUC5AC, MUCSB, and MUC6. All these genes have five major cysteine-rich domains (four von Willebrand factor [vWF] C or D domains and one Cystine-knot [CT] domain) as their distinctive features, in contrast to other non-gel-forming type of mucins. The CT domain is believed to be involved in the initial mucin dimer formation and have very succinct relationship between different gel-forming mucins across different species. Because of gene duplication and evolutional modification, it is very likely that other gel-forming mucin genes exist. To search for new gel-forming mucin candidate genes, a "Hidden Markov Model"(HMM) was built from the common features of the CT domains of those gel-forming mucins. By using this model to screen all protein databases as well as the six-frame translated expression sequence tag and translated human genomic databases, we identified a locus located at the peri-centromere region of human chromosome 12 and the corresponding homologous region of mouse chromosome 15. We cloned the 3′ end of this gene and its mouse homolog. We found one vWF C domain, one CT domain, and various mucin-like threonine/serine-rich repeats. Phylogenetic analysis indicated the close relationship between this gene and the submaxillary mucin from porcine and bovine. A polydispersed signal was observed on the Northern blot, which indicates very large mRNA size. Further analysis of the upstream genomic sequences generated from human and mouse genome projects revealed three additional vWF D domains and many mucin-like threonine/serine- rich repeats. The expression of this gene is restricted to the mucous cells of various glandular tissues, including sublingual gland, submandibular gland, and submucosal gland of the trachea. Based on the chronological convention, we have given the name MUC19 to the human ortholog and Muc19 to the mouse.

Deng, J., Chen, Y., & Reen, W. u. (2000). Induction of cell cornification and enhanced squamous-cell marker SPRR1 gene expression by phorbol ester are regulated by different signaling pathways in human conducting airway epithelial cells. American Journal of Respiratory Cell and Molecular Biology, 22(5), 597-603.

PMID: 10783132;Abstract:

Phorbol ester is a strong inducer for both cell cornification and squamous-cell marker SPRR1 gene expression in conducting airway epithelial cells. However, the signaling pathways involved in the regulation of both events have not been completely elucidated. The current study focuses on the common and divergent pathways involved in the induction of these two activities by phorbol-13-myristate-12-acetate (PMA). Using a protein kinase (PK) C inhibitor, bisindolylmaleimide I, PMA-induced cell cornification and SPRR1 gene expression were abolished. Further, a PKC activator, indolactam V, induced cell cornification in the absence of PMA treatment. These results suggest a PKC-dependent signaling pathway for both gene induction and enhanced cell cornification by PMA. However, a mitogen-activated protein kinase-specific inhibitor, PD98059, could only block the gene induction event but failed to prevent cell cornification induced by PMA. These results suggest that diverse signaling pathways after PKC activation by PMA are involved in the regulation of these two events.

Lee, W., Chen, Y., Wang, W., & Mosser, A. (2015). Infectivity assays of human rhinovirus-A and -B serotypes. Methods in molecular biology (Clifton, N.J.), 1221, 71-81.

Infectivity is a fundamental property of viral pathogens such as human rhinoviruses (HRVs). This chapter describes two methods for measuring the infectivity of HRV-A and -B serotypes: end point dilution (TCID50) assay and plaque assay. End point dilution assay is a quantal, not quantitative, assay that determines the dilution of the sample at which 50 % of the aliquots have infectious virus. It can be used for all the HRV-A and -B serotypes and related clinical isolates that grow in cell culture and induce cytopathic effect (CPE), degenerative changes in cells that are visible under a microscope. Plaque assay is a quantitative assay that determines the number of infectious units of a virus in a sample. After an infectious unit of virus infects one cell, the infected cell produces progeny viruses that then infect and kill a circle of adjacent cells. This circle of dead cells detaches from the dish and thus leaves a clear hole in a cell monolayer. Plaque assay works only for HeLa-adapted HRV-A and -B serotypes that can make visible plaques on the cell monolayer. Currently the end point dilution assay and plaque assay have not been developed for the newly discovered HRV-C.

Kao, C. Y., Chen, Y., Zhao, Y. H., & Reen, W. u. (2003). ORFeome-based search of airway epithelial cell-specific novel human β-defensin genes. American Journal of Respiratory Cell and Molecular Biology, 29(1), 71-80.

PMID: 12600824;Abstract:

β-Defensin is one of the major host defense shields produced by various tissues and organs against microbial infection. To date, four human β-defensins (DEFBs) gene products that share a consensus six-cysteine motif have been discovered. The hidden Markov model (HMM) profile was constructed from the common features of those known β-defensin peptides to search for additional novel DEFB genes. A genome-wide search of the profile against ORFeome-based peptide databases (e.g., Ensembl project) led to the identification of six new DEFB members that also shared the conserved six-cysteine motif. Phylogenetic analysis supported a close relationship of these six new members with existing DEFB genes. Polymerase Chain Reaction studies of human tissue cDNA panels confirmed the expression of all six novel DEFB genes in various tissues. Two of them, DEFB106 and DEFB109, were expressed in the lung. A pilot study with cRNA probes for in situ hybridization and a synthetic propeptide for the functional characterization demonstrated the tissue-/ cell-specific expression and the strong antimicrobial activity of DEFB106. These results support the utility of ORFeome-based HMM search in gene discovery for members of a specific gene family. The novel DEFB genes identified in this study may significantly contribute to overall antimicrobial host defenses.