Topical Administration of Lacritin Peptide for the Treatment of Canine Keratoconjunctivitis Sicca
Channel: JMU ISAT
Date: 2017-07-01

Full Title: Topical Administration of Lacritin Peptide for the Treatment of Canine Keratoconjunctivitis Sicca by Eliza Gaylord
Advised by: Dr. Robert McKown
Sponsor: Dr. Julie Disney
Abstract: Keratoconjunctivitis sicca (KCS), also known as dry eye disease, causes a deficiency of tears in both humans and canines. Due to the lack of effective therapeutics for the treatment of dry eye disease, there is a market potential for a novel secretion enhancing factor. Lacritin, a naturally occurring tear glycoprotein, has demonstrated increased basal tearing in rabbits when topically applied to the ocular surface. This study aims to characterize Lacritin as a biomarker of dry eye disease and potential therapeutic for canines with KCS. A total of 46 canine tear samples, 24 normal and 22 diagnosed with KCS, were obtained through a collaboration with the Virginia-Maryland College of Veterinarian Medicine and transported to James Madison University for analysis. After elution, a bicinchoninic acid assay (BCA) was used to determine total tear protein in the samples. An indirect enzymelinked immunosorbent assay (ELISA) was then used to determine the total tear Lacritin concentration in each sample using previously cloned and purified canine Lacritin as a standard. Total tear protein of the samples was normalized and the proteins were separated using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Western blot analysis with canine Lacritin antibodies was used to visualize Lacritin proteins and densitometry was used to determine the amount of the active Lacritin monomer (~18 kDa) band present. This study demonstrated a correlation between reduced tear production in canines and reduced amounts of canine Lacritin present in tear samples as determined by both ELISA and western blot densitometry. Thus, canine Lacritin shows promise as a replacement therapeutic for the treatment of dry eye disease.