Purchase this article with an account.
J. Yamada, J. Hamuro, C. Mochida, K. Endo, S. Kinoshita; Redox Balance in Corneal Tissues Dictate the Outcome of Corneal Transplantation . Invest. Ophthalmol. Vis. Sci. 2006;47(13):1299.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
We previously reported that the intracellular glutathione (icGSH) content of antigen–presenting cells (APCs) elicited the plasticity depending on the pathogenic status in tissue microenvironments, and that increased icGSH content of APCs directs Th1 type response, strongly associated with corneal allograft rejection. GSH is also known to constitute the first line of cellular defense against oxidative tissue injury. In this study, thiol redox balance in corneal tissues was kinetically monitored in a murine model of corneal transplantation to further clarify the role of thiol redox balance in corneal tissues to direct the graft acceptance or rejection.
Corneal grafts from C57BL/10 (allogeneic) or BALB/c (syngeneic) donor mice were placed on neovascularized graft beds of a BALB/c recipient mouse. Grafted eyes were enucleated on day 7, 14, and 21days after grafting. Normal eyes were used as controls for thiol redox status in corneal tissues. Enucleated eyes were immediately frozen in liq. N2 and sectioned for staining by CD11b or monochlorobimane (MCB) which is commonly used to quantify icGSH content in many tissues. The stained specimens were analysed by confocal laser scanning microscopy.
Donor corneal epithelial layer displayed stronger MCB fluorescence than stromal and endothelial layers, both in grafted and normal eye tissues. MCB fluorescence in grafted corneal central– and recipient peripheral epithelial layer was reduced 7 days after grafting, then continued to keep the reduced level in allogenic donor corneas until 21 days, while those in syngeneic corneas recovered to normal intensity in 21 days, postoperatively. Contrary to epithelial layer, icGSH content of CD11b+ cells, infiltrated in stromal tissue, was elevated through 7 to 21 days after grafting, indicative of skewing to Thl tropic environments in stromal tissues after grafting. Infiltration of CD11b+ cells in stromal tissues was far more evident in allogeneic corneal grafting than those in syngeneic grafting, although no meaningful differences were detected in icGSH of CD11b+ cells in both groups.
Oxidative cellular stress driven by immune/inflammatory axis during allograft rejection response may promote the exchange reaction of SH to S–S (production of GSSG and protein–S–S–) in corneal epithelial layer. In contrast, an increased number of a reductive form of macrophages (RMp) with high icGSH content infiltrated into donor stromal layer, thereby RMp may participate in allograft immune rejection.
This PDF is available to Subscribers Only