Abstract
Purpose: :
To evaluate the involvement of type XVIII collagen in corneal re–innervation.
Methods: :
The expression of type XVIII collagen in C57BL6 (wild type; WT) mouse corneal nerve was assayed by confocal microscopy using anti–type XVIII collagen antibody. Corneal nerves in WT and type XVIII collagen knockout (Col18al–/–) mice were evaluated using electron microscopy and immunohistochemical analysis. Neurite sprouting was evaluated using a keratectomy wound healing model.
Results: :
Type XVIII collagen was localized to the area surrounding corneal nerve bundles in WT, which corresponded to the corneal nerve basal lamina as evidenced by co–localization of type IV collagen and laminin–2. In Col18al–/– mice, corneal nerve lacked these basal lamina markers and displayed naked corneal nerve bundle by electron microscopy. After keratectomy wound, Col18al–/– mouse corneas showed delayed neurite extension when compared to those of WT mice.
Conclusions: :
Type XVIII collagen, expressed in corneal nerve basal lamina, may play an important role in corneal re–innervation.
Keywords: cornea: basic science • innervation: neural regulation