title: Gene expression in human accessory lacrimal glands of Wolfring.
abstract: OBJECTIVE
  The accessory lacrimal glands are assumed to contribute to the production of tear fluid, but little is known about their function. The goal of this study was to conduct an analysis of gene expression by glands of Wolfring that would provide a more complete picture of the function of these glands.
  
  
  METHODS
  Glands of Wolfring were isolated from frozen sections of human eyelids by laser microdissection. RNA was extracted from the cells and hybridized to gene expression arrays. The expression of several of the major genes was confirmed by immunohistochemistry.
  
  
  RESULTS
  Of the 24 most highly expressed genes, 9 were of direct relevance to lacrimal function. These included lysozyme, lactoferrin, tear lipocalin, and lacritin. The glands of Wolfring are enriched in genes related to protein synthesis, targeting, and secretion, and a large number of genes for proteins with antimicrobial activity were detected. Ion channels and transporters, carbonic anhydrase, and aquaporins were abundantly expressed. Genes for control of lacrimal function, including cholinergic, adrenergic, vasoactive intestinal polypeptide, purinergic, androgen, and prolactin receptors were also expressed in gland of Wolfring.
  
  
  CONCLUSIONS
  The data suggest that the function of glands of Wolfring is similar to that of main lacrimal glands and are consistent with secretion electrolytes, fluid, and protein under nervous and hormonal control. Since these glands secrete directly onto the ocular surface, their location may allow rapid response to exogenous stimuli and makes them readily accessible to topical drugs.
authors.affiliation: Department of Biology, Calvin College, Grand Rapids, Michigan 49546, USA. jubels@calvin.edu
authors.forename: John L
authors.initials: JL
authors.lastname: Ubels
authors.forename: Ilene K
authors.initials: IK
authors.lastname: Gipson
authors.forename: Sandra J
authors.initials: SJ
authors.lastname: Spurr-Michaud
authors.forename: Ann S
authors.initials: AS
authors.lastname: Tisdale
authors.forename: Rachel E
authors.initials: RE
authors.lastname: Van Dyken
authors.forename: Mark P
authors.initials: MP
authors.lastname: Hatton
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005136:Eye Proteins / Q000235:genetics*; D005143:Eyelids / Q000378:metabolism; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D015870:Gene Expression / Q000502:physiology*; D020869:Gene Expression Profiling; D006023:Glycoproteins / Q000235:genetics; D006801:Humans; D007765:Lacrimal Apparatus / Q000378:metabolism*; D007781:Lactoferrin / Q000235:genetics; D054834:Lipocalins / Q000235:genetics; D008297:Male; D008856:Microscopy, Fluorescence; D008875:Middle Aged; D009113:Muramidase / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D046888:Tissue Array Analysis
chemical_list: D005136:Eye Proteins; D006023:Glycoproteins; C431764:LACRT protein, human; C490098:LTF protein, human; D054834:Lipocalins; D009113:Muramidase; D007781:Lactoferrin