Improved nude mouse models for green fluorescence human endometriosis

Aim: To establish an improved noninvasive fluorescent animal model for endometriosis.

Material and methods: Adenovirus encoding enhanced green fluorescent protein (Ad-eGFP) was used to transfect primary culture endometrial glandular cells and stromal cells (purified cell transfection and mixed injection, Group 1) as well as endometrial fragments (tissues transfection and injection, Group 2). Transfection results were compared between the cells and tissues in vitro. The GFP-transfected cells suspension of Group 1 or endometrial fragments of Group 2, with similar weight, were injected into nude mice subcutaneously and noninvasively observed every 5 days until day 15 (Subgroup 1, N = 5), day 20 (Subgroup 2, N = 5) or day 25 (Subgroup 3, N =11). The positive rates and duration times of the fluorescent lesions were calculated.

Results: After 18 h of incubation, glandular cells and stromal cells all had higher GFP-positive rates. In vivo imaging showed that the GFP positive rates of Group 1 were significantly higher than those of Group 2. The fluorescent-positive durations of Groups 1 and 2 were 23.636 ± 4.523 days and 5.909 ± 5.394 days, respectively (P < 0.001). In vivo analysis demonstrated that on days 15, 20, and 25, there were more typical lesions and fluorescent-positive lesions formed in Group 1 and that the lesion weight in Group 1 was greater. The structures of the lesions were all identified as human origin.

Conclusion: A noninvasive animal model for endometriosis created by subcutaneous injection of an Ad-eGFP-transfected endometrial glandular and stromal cells suspension had higher a positive rate, longer duration time of fluorescent imaging and greater lesion weight.