Abstract
Purpose: :
Mammalian PGLYRP1 is highly expressed in the bone marrow and neutrophils and has a direct antibacterial effect in vitro. We found Pglyrp1 gene significantly expressed in the cornea. This observation directed us to further study the localization of PGLYRP1 protein in cornea and the role of this protein in cornea.
Methods: :
Immunofluorescence analysis was performed on frozen eye section of the human and mouse by staining with antibodies against human and mouse PGLYRP1 respectively. Expression of PGLYRP1 in BALB/c versus Pglyrp1-/- mouse cornea and corneal epithelium were assessed by western blot. PGLYRP1 mRNA expression level in mouse corneal epithelium was tested by real-time PCR. Corneal wound healing was evaluated by fluorescein staining in BALB/c versus Pglyrp1-/- mouse. Antibacterial effects of corneal PGLYRP1 were assayed by measuring bacterial growth in vitro, in the presence of wild type corneal epithelial extracts before and after antibody-mediated blocking of PGLYRP1.
Results: :
PGLYRP1 is highly expressed in the epithelium of human and mouse cornea. Further whole mount staining of the mouse cornea confirmed that PGLYRP1 is expressed in the differentiated superficial and intermediate wing cells of the epithelium. In vitro corneal epithelial extracts of Pglyrp1-/- mouse shows reduced bacteriostatic activity compared to wild type BALB/c mouse. Healing of epithelial injury was delayed in the Pglyrp1-/- mouse.
Conclusions: :
This is the first report of the presence of this antimicrobial protein in the corneal epithelium. At the ocular surface PGLYRP1 may be a microbe deterrent with broad specificity. Additionally delayed corneal wound healing in the Pglyrp1-/- mouse implicate possible interactions between PGLYRP1 and epithelial cell survival associated signaling events.
Keywords: cornea: epithelium • protective mechanisms • wound healing