title: A thermo-responsive protein treatment for dry eyes.
abstract: Millions of Americans suffer from dry eye disease, and there are few effective therapies capable of treating these patients. A decade ago, an abundant protein component of human tears was discovered and named lacritin (Lacrt). Lacrt has prosecretory activity in the lacrimal gland and mitogenic activity at the corneal epithelium. Similar to other proteins placed on the ocular surface, the durability of its effect is limited by rapid tear turnover. Motivated by the rationale that a thermo-responsive coacervate containing Lacrt would have better retention upon administration, we have constructed and tested the activity of a thermo-responsive Lacrt fused to an elastin-like polypeptide (ELP). Inspired from the human tropoelastin protein, ELP protein polymers reversibly phase separate into viscous coacervates above a tunable transition temperature. This fusion construct exhibited the prosecretory function of native Lacrt as illustrated by its ability to stimulate β-hexosaminidase secretion from primary rabbit lacrimal gland acinar cells. It also increased tear secretion from non-obese diabetic (NOD) mice, a model of autoimmune dacryoadenitis, when administered via intra-lacrimal injection. Lacrt ELP fusion proteins undergo temperature-mediated assembly to form a depot inside the lacrimal gland. We propose that these Lacrt ELP fusion proteins represent a potential therapy for dry eye disease and the strategy of ELP-mediated phase separation may have applicability to other diseases of the ocular surface.
authors.affiliation: Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA, United States.
authors.forename: Wan
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA, United States.
authors.forename: Aarti
authors.initials: A
authors.lastname: Jashnani
authors.affiliation: Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA, United States.
authors.forename: Suhaas R
authors.initials: SR
authors.lastname: Aluri
authors.affiliation: Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA, United States.
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Gustafson
authors.affiliation: Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA, United States.
authors.forename: Pang-Yu
authors.initials: PY
authors.lastname: Hsueh
authors.affiliation: Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA, United States.
authors.forename: Frances
authors.initials: F
authors.lastname: Yarber
authors.affiliation: Department of Integrated Science and Technology, James Madison University, Harrisonburg, VA, United States.
authors.forename: Robert L
authors.initials: RL
authors.lastname: McKown
authors.affiliation: Department of Cell Biology, School of Medicine of the University of Virginia, Charlottesville, VA, United States.
authors.forename: Gordon W
authors.initials: GW
authors.lastname: Laurie
authors.affiliation: Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA, United States; Department of Physiology and Biophysics, Keck School of Medicine of the University of Southern California, Los Angeles, CA, United States.
authors.forename: Sarah F
authors.initials: SF
authors.lastname: Hamm-Alvarez
authors.affiliation: Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA, United States; Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, United States. Electronic address: jamackay@usc.edu.
authors.forename: J Andrew
authors.initials: JA
authors.lastname: MacKay
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D003607:Dacryocystitis / Q000276:immunology; D003692:Delayed-Action Preparations; D015352:Dry Eye Syndromes / Q000188:drug therapy*; D004549:Elastin / Q000737:chemistry / Q000627:therapeutic use*; D005260:Female; D006023:Glycoproteins / Q000737:chemistry / Q000627:therapeutic use*; D054819:Hexosaminidase B / Q000378:metabolism; D006358:Hot Temperature; D006801:Humans; D066298:In Vitro Techniques; D007765:Lacrimal Apparatus / Q000378:metabolism; D008297:Male; D008810:Mice, Inbred C57BL; D016688:Mice, Inbred NOD; D061251:Primary Cell Culture; D011506:Proteins / Q000737:chemistry / Q000627:therapeutic use*; D011817:Rabbits; D011993:Recombinant Fusion Proteins; D013666:Tears / Q000378:metabolism; D057900:Transcytosis
chemical_list: D000199:Actins; D003692:Delayed-Action Preparations; D006023:Glycoproteins; C431764:LACRT protein, human; D011506:Proteins; D011993:Recombinant Fusion Proteins; D004549:Elastin; D054819:Hexosaminidase B
keywords: Elastin-like polypeptides (ELPs); Lacrimal gland; Lacritin; Prosecretory; Thermo-responsive; Uptake