The anti-VEGF-B scFv significantly regressed established but not developing corneal blood vessels in rats.

Sex-based differences in susceptibility have been reported for a number of neovascular ocular diseases. We quantified corneal neovascularization, induced by superficial silver nitrate cautery, in male and female inbred albino Sprague-Dawley, inbred albino Fischer 344, outbred pigmented Hooded Wistar and inbred pigmented Dark Agouti rats of a range of ages. Corneal neovascular area was quantified on haematoxylin-stained corneal flatmounts by image analysis. Pro-and anti-angiogenic gene expression was measured early in the neovascular response by quantitative real-time polymerase chain reaction. Androgen and estrogen receptor expression was assessed by immunohistochemistry. Male rats from all strains, with or without ocular pigmentation, exhibited significantly greater corneal neovascular area than females: Sprague-Dawley males 43±12% (n = 8), females 25±5% (n = 12), p = 0.001; Fischer 344 males 38±10% (n = 12) females 27±8% (n = 8) p = 0.043; Hooded Wistar males 32±6% (n = 8) females 22±5% (n = 12) p = 0.002; Dark Agouti males 37±11% (n = 9) females 26±7% (n = 9) p = 0.015. Corneal vascular endothelial cells expressed neither androgen nor estrogen receptor. The expression in cornea post-cautery of Cox-2 , Vegf-a and Vegf-r2 was significantly higher in males compared with females and Vegf-r1 was significantly lower in the cornea of males compared to females, p<0.001 for each comparison. These data suggest that male corneas are primed for angiogenesis through a signalling nexus involving Cox-2 , Vegf-a , and Vegf receptors 1 and 2. Our findings re-enforce that pre-clinical animal models of human diseases should account for sex-based differences in their design and highlight the need for well characterized and reproducible pre-clinical studies that include both male and female animals.

No abstract

Unmodified controls were also performed. Graft survival was assessed by corneal clarity and rejection was confirmed histologically. Results In organ-cultured corneas, expression of anti-CD4scFv was detected at 2 days post-transduction with the adenoviral vector, compared with 5 days post-transduction with the lentivector, and was 10-fold higher from the former. More inflammation was observed in Ad-CD4scFv-modified allografts than in Lv-CD4scFv-modified grafts at 15 days postsurgery (p=0.01). The median time to rejection for unmodified, LV-eYFP and Ad-CD4scFv grafts was day 17, compared with day 22 for Lv-CD4scFv grafts (p≤0.018). Conclusion Donor corneas transduced with a lentiviral vector carrying anti-CD4scFv cDNA showed a modest but significant prolongation in graft survival compared with unmodified, Lv-eYFP and Ad-CD4scFv grafts. However, rejection still occurred in all Lv-CD4scFv grafts, indicating that sensitization may have been delayed but was not prevented.

Objective: To determine corneal allograft endothelial cell (EC) replacement and the origin of the regenerative ECs in response to rejection, and to deduce new strategy to clinical human corneal transplantation. Methods: The rejection kinetics of untreated corneal allografts was observed in a MHC class I/II disparate DA-Lewis combination. The EC integrity of rejected allografts was compared with that of normal corneas. Then the transparency recovery of the rejected grafts was analyzed. The recovering grafts were collected at different time point after rejection for EC staining to clarify the EC replacement and the origin of the regenerative cells. To elucidate the infl uence of treatment on EC replacement, adenovirus-mediated nerve growth factor (AdNGF) was transfected into the grafts before transplantation. The rejection kinetics and EC integrity of the treated grafts were documented after transplantation and compared with that of untreated cases. Results: All corneal allografts without treatment were rejected and their ECs shed. The rejected corneas recovered clear gradually. The re-constructed graft endothelium was covered by recipient-derived ECs raised from the adjacent host cornea but not from circulation-derived ECs. The AdNGF gene therapy protected the grafts against transplanted-trauma, and altered the rejection kinetics and the EC integrity. Conclusions: Recipient-derived adjacent ECs reconstruct the structure and function of rejected corneal allograft, different from other kind of grafts. EC replacement represents a reparative response to injury rather than a constant mechanism of tissue maintenance dependant on the tissue-specifi city and the milieu where the graft survives. Initiation of host-derived EC proliferation, protection of graft ECs, inducing EC chimerism of graft and recipient, and surgery approach improvement could contribute to the corneal allograft.