Abstract
Purpose: :
Up to 30-40 % of corneal grafts are lost during organ cultivation due to endothelial cell damage, thereby limiting the number of available transplants. Here, the influence of culture media on cell viability of mice corneal endothelium and epithelium was investigated.
Methods: :
Mice cornea were excised and cultured for 4 days in standard corneal organ culture medium MEM+2% fetal calf serum (FCS) or serum-free Human Endothelial-SFM, each supplemented with either 6% Dextran or 7,5% hydroxyl-ethyl starch (HES). In some corneas, apoptosis was induced by staurosporine administration (0,5 µmol/l, at day 3) as apoptosis control. Samples were then fixed, paraffin-embedded and evaluated morphologically (HE-staining) and by immunohistochemical detection of caspase-3 and -8, Bcl-2 and HSP-32.
Results: :
Phase contrast microcopy revealed no endothelial cell alterations after 24h of organ cultivation. After 4 days the endothelia of SFM cultured corneas appeared normal and showed strong staining for HSP-32, while in MEM cultured corneas the endothelia were lost or showed morphological signs of apoptosis, and were positive for caspase-3 and caspase-8, but had less HSP-32 positivity. After 4 days the epithelia of SFM cultured corneas had a regular architecture with 1 basal layer of prismatic cells, 2 layers of cuboidal cells and 2 layers of suprabasal squamous cells. The epithelia of MEM cultured corneas had only up to 2 layers of cuboidal cells covered by 2 layers of squamous cells, but no prismatic cells, and showed stronger staining for caspase-3, caspase-8 and HSP-32 compared to SFM-stored corneas. Bcl-2-staining was more regular in the epithelia of SFM-stored corneas compared to MEM-stored corneas. Caspase-3 staining was slightly higher in HES-supplemented media than in Dextran-supplemented media.
Conclusions: :
SFM-based media promoted corneal endothelial and epithelial cell survival during organ cultivation, while MEM-based media lead to endothelial cell loss and cell reduction in the epithelium and stroma.
Keywords: cornea: storage • transplantation • apoptosis/cell death