Treating Stress Urinary Incontinence With Stem Cells

medicalnewstoday ^ | 06.15.08

[Coleus]

Dr. Rodriguez discussed use of stem cells for treating SUI (Stress Urinary Incontinence). A stem cell is embryonic, adult, or engineered. Embryonic stem cells come from the blastocyst which is totipotent or pluripotent. These cells are immortal, identical clonal cells with long-term self renewal. Controversies include possible tumor formation, the difficulty maintaining cell cultures and ethical issues.

Embryonic stem cells can differentiate into ectoderm, mesoderm and endoderm. Adult stem cells include hematopoetic stem cells, such as derived from bone marrow. This requires a bone marrow harvest, with low yield and difficulty to expand clones. A variety of other tissues have been studied such as muscle or fat. This avoids ethical issues and it is easier to expand clones. However they are not immortal, identical, or totipotent and have no specific markers for identification. A technique of somatic cell nuclear transfer was described, in which the DNA from an oocyte is transferred to other cell types. This technique was used to clone Dolly the sheep, for example. Reprogramming the nuclear material of an existing adult cell type is also recently reported, and a new potential technique.

Regarding SUI, the urethra can have atrophy and loss of neuronal mass. Research is focusing on cell type, matrix and delivery systems, tissue survival and function. The cells sources include adipose derived stem cells for intrinsic smooth muscle of the urethra replacement or muscle derived stem cells for skeletal sphincteric reconstruction. She described development of an animal model the mimic this process. She showed that the cells migrate in vivo to appropriate tissue areas. Microspheres permit localization of the cells. They have reported clonogenic stem cell differentiation of adipose cells. Implantation into animals and tissue harvesting data supports cell differentiation and function. Muscle derived stem cells are used for regeneration of the skeletal sphincter. At 6 weeks in animals using these cells, there is restitution of leak-point pressure.

An Austrian group reported on injection of collagen and fibroblasts with progenitor cells in the sphincter area of patients. They had 79% continence at one year with increased thickness and contractility of the rhabdosphincter, but continence decreased to 63% at 2 years. She challenged herself with the question of whether this is a functional process or only a sophisticated bulking agent. Presented by Larissa V. Rodriguez, MD, at the Annual Meeting of the American Urological Association (AUA) - May 17 - 22, 2008. Orange County Convention Center - Orlando, Florida, USA.