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Our laboratory is dedicated to understanding the pathophysiology of Chronic Rhinosinusitis (CRS). CRS is one of the most common medical complaints, affecting 16% of the U.S. population with an estimated aggregated cost of $6 billion dollars annually. The presumed pathophysiology leading to CRS is stasis of sinonasal secretions secondary to diminished function of the sinonasal ciliated mucosa, with subsequent microbial overgrowth and frank infection and persistent inflammation. Thus, our laboratory has three main themes: (i) sinonasal cilia function, (ii) microbial (biofilm) growth and interactions with the sinonasal mucosa, and (iii) generation of novel topical therapies for CRS patients. Using a high-speed video camera in conjunction with differential interference contrast (DIC) microscopy, we have been able to capture beating cilia and measure cilia beat frequency (CBF) from human sinus mucosal explants under multiple conditions. In order to better understand and characterize the cellular modulation of sinonasal CBF, we have incorporated the polarized epithelial air-liquid interface (ALI) culture and modified our capture system to include an inverted scope with interference modulation contrast (IMC) microscopy. In the hopes of using transgenic mouse technology, we have additionally incorporated the use of the mouse nasal septum for ALI and subsequent CBF analysis.
www.uphs.upenn.edu/pennorl/b_rhino_research.htm
The Technique
The ability to study ciliary physiology in vitro is of utmost importance in understanding the pathophysiology of CRS. Respiratory epithelium cultured at an ALI has been traditionally derived from mouse tracheas and human airways. Because the percentage of ciliated respiratory epithelial cells on a mouse trachea is relatively small compared to the nasal septum, reconstitution in an ALI culture does not approximate the high percentage of ciliated epithelium present in human sinonasal mucosa. Thus, murine tracheas are not necessarily representative of the sinonasal cavity and thus not ideal for the study of CRS. Our experience using human sinonasal tissue for establishment of ALI has demonstrated tremendous variability from culture to culture. Inherent in using human samples is an array of uncontrolled variables including genetics, medical history, environmental allergies, medication use, and exposure to environmental pollutants. Thus, we turned to the murine nose, specifically the septum for reproducible cultures in which to manipulate the signaling cascades regulating CBF and other physiologic and biochemical functions of the airway ciliated epithelial cell.
See “Murine nasal septa for respiratory epithelial air-liquid interface cultures” on page 195.
