Mucins, heavily glycosylated, bottle-brush shaped proteins are generated throughout our bodies to facilitate wetting and interfacial transport. In our respiratory system, mucins and generated by goblet cells above the periciliary liquid layer (PCL) and develops a viscoelastic layer that traps unavoidable contaminants (dust, bacteria, viruses) that are introduced through breathing. The viscoelasticity of this mucus layer must be properly regulated (ph, salinity, concentration) to allow the PCL to properly propel it upward and clear it from our system. Disease states, such as acute asthma and cystic fibrosis, adversely affect the rheological response and, for this purpose, a “live cell rheometer” (LCR) has been developed whereby the mucus created by living bronchial epithelial cells can be measured. To simulate asthmatic conditions, the cells are exposed to an inflammatory cytokine, IL-13. Using the LCR, it is observed that the mucus layer transitions from a viscoelastic liquid to a viscoelastic solid, indicating the mucus layer has developed a degree of crosslinking. Conversely, the introduction of a muco-active drug can be explored as a means of reverting the mucus back towards a moveable, viscoelastic liquid. For this purpose, DTT, a common reducing agent is shown to produce a desired effect.
The gastric epithelium also produces a mucus layer, although it is much more fluid that that produced by the bronchial cells. However, as in the case of the respiratory system that becomes inflamed under conditions of acute asthma, intestinal disorders, such as Chron’s disease, can also result in an overproduction of mucins and preliminary results using the LCR will be presented on this system.
About the Speaker
Gerald Fuller is the Fletcher Jones Professor of Chemical Engineering at Stanford University. He joined in 1980 following his graduate work at Caltech where he acquired his MS and PhD degrees. His undergraduate education was obtained at the University of Calgary, Canada. Professor Fuller’s interests lie in studies of rheology and interfacial fluid mechanics. His work has been recognized by receipt of the Bingham Medal of The Society of Rheology, membership in the National Academy of Engineering, election to the American Academy of Arts and Science, and honorary doctorates from the Universities of Crete, Greece, and Leuven, Belgium. He presently serves as the General Secretary to the International Committee on Rheology.
Hosts: Professor Jie Feng and Professor Randy Ewoldt