Yunxiang Zhu, PhD

Research Biosketch Contact

Yunxiang Zhu is a Research Associate in the laboratory of Dr. C William Davis.

Research Focus

My intellectual and professional development has been shaped by a desire to discover and elucidate physiological and pathological processes involved in human diseases, especially the upper and lower airways, to generate potentially new therapeutic approaches to disease.

Practicing as an ENT physician after graduating from Tongji Medical University, China, my interests gradually focused on Rhinology. Although Rhinology is a branch of otolaryngology, nose and nasal sinus diseases should be considered in part to be airway diseases since they are very similar in epithelial cell phenotype, defense mechanisms, and pathophysiology. Hence, for the last several years, I have been working as a Postdoctoral Research Associate and Research Associate currently, in CW Davis' Lab in the UNC Cystic Fibrosis Center.

The goal of my work has been to understand the molecular mechanism of mucin secretion. Mucins are secreted from goblet cells and submucosal glands; after that, they mature into mucus, a key component in mucocialiary clearance. An experimental mouse trachea perfusion system was established, and multiple strains of gene-manipulated mice were studied.

In our most significant work, we found that the exocytotic priming protein, Munc13-2 mediates basal mucin secretion. This work was conducted in the mouse airways, where the principal secretory cell, the Clara cell, was previously considered a non-mucin secreting cell type under control conditions. In the Munc13-2 null mouse, we observed significant mucin stores. Significantly, these findings may indicate that human Clara cells are the source of mucins in the small airways, the site where airway diseases such as chronic bronchitis and cystic fibrosis are thought to be initiated. Hence, our work indicates that the mucin basal secretory pathway may play an important role in airway physiology and pathology.

In the present, I am focusing on studying the molecular mechanism and regulation of basal mucin secretion and of mechanical stimulation induced mucin secretion.

Current Research Projects

  • Project: The molecular mechanism of basal mucin secretion of goblet cells.
  • Project: The molecular mechanism of mechanical stimulation-induced mucin secretion.
  • Project: The mechanism of intracellular packing of the mucin granule and the mucus maturing process.

Previous Research Projects

  • Project: Smoking regulates mucin secretion and/or mucin synthesis.
    Result: Smoking does not trigger mucin secretion.
  • The regulating mechanism of mucin biosynthesis in the goblet cells.
    Result: Post-transcriptional regulation mechanism plays an important role in biosynthesis.
  • Project: Munc13-2 regulates goblet cell mucin secretion.
    Result: Munc13-2 regulates basal mucin secretion of goblet cells, but not agonist-stimulated mucin secretion. Clara cells appear to be a source of mucin in mouse proximal airway.
  • Project: MARCKS (myristoylated alanine-rich C kinase substrate) regulates degranulation of mast cells and mucin secretion of airway goblet cells.
    Result: Although MARCKS is one of the PKC substrates, it is not essential for either degranulation of mast cells, or mucin secretion of airway goblet cells.
  • Project: PKCs regulate goblet cell mucin secretion.
    Result: nPKCε, a P2Y2-R downstream effector, regulates mucin secretion from airway goblet cells.

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Biographical Sketch

Education and Training

(2004-2011) Postdoctoral Research Associate, Cystic Fibrosis Center (Dept. of Pulmonary Medicine), University of North Carolina at Chapel Hill, Chapel Hill, NC.

(2001-2004) M.D. (Ph.D. Equivalent), Dept. of Otolaryngology- Head and Neck Surgery, Tongji Medical Col of Huazhong Univ. of Science & Technology, Wuhan, China.

(1995-1998) Residency, Dept. of Otolaryngology- Head and Neck Surgery, Tongji Hospital, Tongji Medical Col of Huazhong Univ of Science & Technology, Wuhan, China.

(1988-1995) Combined M.B. (M.D. Equivalent)/M. Med., Dept. of Surgery, Tongji Hospital, Tongji Medical Col of Huazhong Univ. of Science & Technology, Wuhan, China.

Professional Experience

(2009-present) Research Associate, Cystic Fibrosis Center (Dept. of Pulmonary Medicine), University of North Carolina at Chapel Hill, Chapel Hill, NC.

(1998-2001) Attending Physician, Dept. of Otolaryngology- Head and Neck Surgery, Tongji Hospital, Tongji Medical Col of Huazhong Univ of Science & Technology, Wuhan, China.

Selected Publications

Please see Pubmed feed in righthand column for links to current publications.

1. Seminario-Vidal L, Okada SF, Sesma JI, Kreda SM, van Heusden CA, Zhu Y, et al. RHO signaling regulates pannexin 1-mediated ATP release from airway epithelia. J Biol Chem. 2011 Jul 29;286 (30):26277-86. PMID: 21606493.

2. Zhu Y, Ehre C, Abdullah LH, et al. Munc13-2 -/- baseline secretion defect reveals source of oligomeric mucins in mouse airways. J Physiol. 2008 Apr;586(7):1977-92. PMID: 18258655. This paper was highlighted in the Physiology, 23:184, 2008.

3. Ehre C, Zhu Y, Abdullah LH, et al. nPKCε, a P2Y2-R downstream effector in regulated mucin secretion from airway goblet cells. Am J Physiol Cell Physiol. 2007 Nov; 293(5):C1445-54. PMID:17728398.

4. Zhu Y, He Y, Gao Q, et al. 2003. The value of Multiplanar Reconstructions of Helical CT for Endoscopic Sinus Surgery. Journal of Chinese Otorhinolaryngology (Chinese). 38(3), 233-234.

5. Gao Q, Lui Z, Tao Y, Cui Y, You X, Zhu Y, et al. 1998. Nasal packing and packing material choosing after ESS (with clinical analysis of 769 cases). Journal of Clinical Otorhinolaryngology (Chinese). 12(11), 493-495.

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Contact Information

6010 Thurston-Bowles Bldg.
The University of North Carolina at Chapel Hill
Campus Box #7248
Chapel Hill, NC 27599
Phone (work): (919) 966-7061
Phone (mobile): (919) 619-4507
Email: yunxiang@email.unc.edu

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