title: Role of neurotrophins and neurotrophin receptors in rat conjunctival goblet cell secretion and proliferation.
abstract: OBJECTIVE
  To determine which neurotrophins (NTs)-nerve growth factor (NGF), brain-derived neurotrophin (BDNF), neurotrophin-3 (NT3), and neurotrophin-4 (NT4)-and their receptors (NTrs) TrkA, TrkB, TrkC, and p75 are present in rat conjunctiva and cultured rat goblet cells (CGCs) and whether NTs stimulate glycoconjugate secretion or cell proliferation.
  
  
  METHODS
  Western blot analysis and immunofluorescence microscopy determined presence and location of NTs and NTrs. CGCs were incubated with NTs (10(-12)-10(-8) M) for 2 or 24 hours to measure secretion or proliferation, respectively. An enzyme-linked lectin assay analyzed glycoconjugate secretion. WST-8 determined cell proliferation.
  
  
  RESULTS
  Western blot analysis showed all NTs and NTrs in both conjunctiva and CGCs. The cytoplasm of conjunctival stratified squamous cells and goblet cell lateral membranes contained NGF, BDNF, and NT4. Stratified squamous cell membranes contained NT3. In CGCs, NGF and BDNF had punctuate perinuclear staining. The nucleus contained NT3 and cytosol contained NT4. TrkA, TrkB, and p75 immunoreactivity was on conjunctival goblet cell lateral membranes. Plasma membranes of the basal layer of stratified squamous cells contained TrkA. Stratified squamous cell and goblet cell nuclei contained TrkC. In CGCs, all NTrs were present in the nucleus. NGF and BDNF, but not NT3 and NT4, induced a concentration-dependent stimulation of secretion from CGCs with a maximum increase of 10(-9) M each. No effect on cell proliferation was detected with any NTs.
  
  
  CONCLUSIONS
  Rat conjunctival goblet cells and CGCs contain all NTs and NTrs. Only NGF and BDNF stimulated goblet cell glycoconjugate secretion, and none induced CGC proliferation.
authors: Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, 20 Staniford Street, Boston, MA 02114, USA. jose.rios@schepens.harvard.edu
authors: J David
authors: JD
authors: Ríos
authors: Emiliano
authors: E
authors: Ghinelli
authors: Jian
authors: J
authors: Gu
authors: Robin R
authors: RR
authors: Hodges
authors: Darlene A
authors: DA
authors: Dartt
mesh_terms: D000818:Animals; D015153:Blotting, Western; D018929:Cell Culture Techniques; D049109:Cell Proliferation; D003228:Conjunctiva / Q000166:cytology / Q000378:metabolism*; D019084:Fluorescent Antibody Technique, Indirect; D020397:Goblet Cells / Q000378:metabolism*; D008297:Male; D008856:Microscopy, Fluorescence; D009077:Mucins / Q000378:metabolism*; D009414:Nerve Growth Factors / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017475:Receptors, Nerve Growth Factor / Q000378:metabolism*
chemical_list: D009077:Mucins; D009414:Nerve Growth Factors; D017475:Receptors, Nerve Growth Factor