Purpose:
To investigate the role of interleukin-1 (IL-1) in modulating myofibroblast viability in mice corneas with haze induced by irregular phototherapeutic keratectomy (PTK).
Methods:
female B6;129S1-Il1r1tm1Roml/J homozygous IL-1RI knockout mice and control B6129SF2/J mice were included in this study. Haze-generating irregular phototherapeutic keratectomy (PTK) was performed in one eye. Mice were euthanized at 1 month and 6 months after surgery and the eyes were cryo-preserved in OCT. The contralateral eye served as unwounded control. There were four eyes in each group at each time point. Immunohistochemistry was performed for α-smooth muscle actin (SMA) and vimentin (Vim) in the unwounded and wounded corneas.
Results:
No stromal SMA was detected in the stroma of unwounded corneas. SMA+ myofibroblast density was significantly higher in the IL-1RI knockout group than the control group at 1 month (1.6±0.2 and 0.7±0.1, respectively) and at 6 months (1.1±0.2 and 0.3±0.1, respectively, table). More vimentin+ cells were detected in the stroma of unwounded Il-1R knockout corneas than unwounded control corneas at 1 month (9.5±0.1 and 6.5±0.4, respectively) and at 6 months (9.06±0.4 and 6.06±0.3, respectively). These differences were significant (p< 0.01).
Conclusions:
Recent in vitro work has demonstrated an antagonistic effect of TGFβ and IL-1 on myofibroblast viability and discovered- IL-1 effects in promoting myofibroblast apoptosis are suppressed by TGFβ. This in situ study confirms that IL-1 is an important modulator of myofibroblast viability during corneal wound healing and that IL-1 may have a role in suppressing vim+ SMA- myofibroblast precursors when stromal levels of TGFβ are low.
Keywords: cornea: stroma and keratocytes • inflammation • refractive surgery: complications