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Branch‐Chain Interpenetration of the Mesothelial Glycocalyx with Naturally‐Occurring Biopolymers
Author(s) -
Zheng Yifan,
Pierce Aidan,
Wagner Willi,
Servais Andrew,
Ackermann Maximilian,
Mentzer Steven
Publication year - 2020
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2020.34.s1.08953
Subject(s) - glycocalyx , mesothelium , mesothelial cell , chemistry , polysaccharide , biophysics , pectin , adhesion , microbiology and biotechnology , biochemistry , anatomy , biology , pathology , medicine , organic chemistry
The mesothelial surface layer of the lung, heart, bowel, and liver is a dynamic epithelial tissue that regulates a variety of physiologic processes including the healing of visceral organ injuries. A major barrier to addressing these injuries is the slippery and nonadhesive surface of visceral organs, which consists of a carbohydrate‐rich glycocalyx. The glycocalyx is difficult to study, however, because traditional fixation methods destroy this carbohydrate layer. To define the mesothelial glycocalyx, we utilized a high pressure (2100 bar) and rapid freezing technique of the pleura. Examining the glycocalyx with scanning electron microscopy, we demonstrated that the pleural glycocalyx is more than 100‐times thicker than previously realized (more than 12 um) and is notable for its branch‐chain polysaccharide structure. The unique branch‐chain structure of the mesothelial glycocalyx is reminiscent of the plant structural heteropolysaccharide called pectin. Pectin has a branch‐chain polysaccharide structure that appears to mirror the glycocalyx. When 35 mm circular pectin films were applied to porcine mesothelium, the pectin films appeared to fuse with the mesothelial surface. Our hypothesis is that pectin adhesion to mesothelium is via branch‐chain entanglement. Quantitative adhesive strength testing demonstrated that pectin was significantly more adhesive to the mesothelial surface than linear‐chain polysaccharide polymers (p<0.0001). The work of adhesion between pectin and mesothelial glycocalyx was measured to be 80 to 90 N*sec while the work of adhesion measured between linear‐chain polymers and mesothelium was 10 to 20 N*sec. Transillumination stereomicroscopy of the interaction between two branch‐chain polymers demonstrated entanglement of the polymer chains, while stereomicroscopy of the branch‐chain polymer with the linear‐chain polymer or two linear‐chain polymers demonstrated no entanglement. We conclude that the effective binding of pectin to the mesothelial glycocalyx is the result of reciprocal branch‐chain interactions between these structural polysaccharide polymers. We anticipate that the adhesivity between branch‐chain polymers will provide important experimental and therapeutic opportunities in the study of the mesothelium.