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Autologous transplantation of porcine muscle-derived cells into uninjured urethral sphincter enhance urethral closure pressure

Anna Burdzinska¹, Robert Crayton², Bartosz Dybowski², ukasz Koperski³, Marta Idziak¹, Kamila Gala¹, Piotr Radziszewski², Leszek Paczek¹

¹Department of Immunology, Transplantology and Internal Diseases; ²Department of Urology; ³Department of Pathology, Medical University of Warsaw, Warsaw, Poland

Myogenic cell therapy is considered as an alternative method to treat urinary incontinence. Cell transfer into urethral sphincter of rodents was reported to be successful. However, larger animal models usually allow for more adequate testing of new potential therapies. The present study analyses the fate of muscle-derived cells (MDCs) autotransplanted into uninjured porcine external urethral sphincter (EUS) and the effect on maximal urethral closure pressure (MUCP).

The experiment was performed on immature female pigs. Cells isolated for transplantation were identified by immunoblotting and their ability to differentiate. After the third passage, 60x10(6) of MDCs were labeled with fluorochrome PKH26 and injected in three depots into the EUS using urethrocystoscopy (n=5). Urodynamic assessments were performed before transplantation (day 1) and 4 weeks after treatment (day 28). Pigs were euthanized at day 28 and urethras were collected. In control, untreated group (n=5) urodynamic evaluations were performed in the same time points to assess the effect of growth on MUCP changes. Additionally, two pigs in which the vehicle was injected only served as negative control for histological studies.

Isolated MDCs expressed desmin and were able to fuse into myotubes in vitro. Transplanted cells were present at the sites of injections. The areas of fluorescence corresponded to three depots what indicated that injected cells did not migrate. Donor cells were localized within muscle layer, but also in other parts of urethral sections what suggested that the technique of injection was not precise enough. Nevertheless, the mean MUCP value in transplanted group increased from 23.4 at day 1 to 34.5 mmH2O at day 28 (p<0.05). Moreover, the difference between MUCP in transplanted and control groups at day 28 was also significant (increase by 32%, p=0.01).

In conclusion, porcine model is suitable for further optimization of procedures associated with cell therapy in cases of urinary incontinence.