Abstract
Purpose: :
To investigate the effects of lacking transient receptor potential cation channel subfamily V member 1 (TRPV1) receptor on expression of transforming growth factor β1 (TGFβ1), substance P and interleukin-6 (IL-6), all of which are involved in epithelial healing in cornea in mice. Healing of the epithelial defect was also assayed. Substance P is known to be expressed in sensory nerve fibers in cornea.
Methods: :
Corneal epithelial wounds were made in TRPV1 -/- (KO, n = 35) and wild type (WT) mice (n = 35) with 2mm trephine. Healing corneas were processed for total RNA extraction and real-time RT-PCR for TGFβ1, substance P and IL-6 at 6, 12 and 18 hrs post-debridement. Healing pattern of the epithelial defect was also evaluated by the measurement of the remaining defect and histological detection of BrdU-labeled epithelial cells.
Results: :
Expression of mRNAs of Substance P and IL-6, but not TGFβ1, was significantly less in a KO cornea as compared with a WT cornea at 12 hrs. The loss of TRPV1 receptor impaired resurfacing of the defected corneal epithelium and also suppressed cell proliferation in healing epithelium 24 and 36 hours.
Conclusions: :
Lacking TRPV1 ion channel receptor suppressed mRNA expression of substance P and IL-6, as well as impaired healing of corneal epithelium in mice.
Keywords: cornea: epithelium • wound healing • cytokines/chemokines