Fate of mesoangioblasts in a vaginal birth injury model: influence of the route of administration

Currently cell therapy is considered as an experimental strategy to assist the healing process following simulated vaginal birth injury in rats, boosting the functional and morphologic recovery of pelvic floor muscles and nerves. However, the optimal administration route and dose still need to be determined. Mesangioblasts theoretically have the advantage that they can differentiate in skeletal and smooth muscle. We investigated the fate of mesoangioblasts transduced with luciferase and green fluorescent protein reporter genes (rMABs(eGFP/fLUC)) using bioluminescence, immunofluorescence and RT-PCR in rats undergoing simulated birth injury. rMABs(eGFP/fLUC) were injected locally, intravenously and intra-arterially (common iliacs and aorta). Intra-arterial delivery resulted in the highest amount of rMABs(eGFP/fLUC) in the pelvic organs region and in a more homogeneous distribution over all relevant pelvic organs. Sham controls showed that the presence of the injury is important for recruitment of intra-arterially injected rMABs(eGFP/fLUC). Injection through the aorta or bilaterally in the common iliac arteries resulted in comparable numbers of rMABs(eGFP/fLUC) in the pelvic organs, yet aortic injection was faster and gave less complications.