Bone marrow stem cells for urologic tissue engineering.
OBJECTIVE
Experiments in rats and dogs have demonstrated the potential of bone marrow-derived mesenchymal stem cells (MSCs) for urinary tract tissue engineering. However, the small graft size in rats and a failure to identify the MSCs in engineered tissues made it difficult to assess the true potential of these cells. Our goals were to characterize MSCs from pigs, determine their ability to differentiate into smooth muscle cells (SMCs) and use them in an autologous augmentation cystoplasty.


METHODS
MSCs were isolated from pigs and analyzed for common markers of MSCs by flow cytometry. SMC differentiation was determined by immunoblotting. MSCs were isolated, genetically labeled, expanded in vitro, seeded onto small intestinal submucosa (SIS) and used for autologous bladder augmentation.


RESULTS
Porcine MSCs are morphologically and immunophenotypically similar to human MSCs. Culturing MSCs at low density enhances proliferation rates. MSCs consistently differentiate into mature SMCs in vitro when maintained at confluence. Labeled MSCs grew on SIS over one week in vitro and survived a 2-week implantation as an autologous bladder augment in vivo. Some label-positive cells with SMC morphology were detected, but most SMCs were negative. Notably, many cells with a urothelial morphology stained positively.


CONCLUSIONS
Porcine MSCs have similar properties to MSCs from other species and consistently undergo differentiation into mature SMC in vitro under specific culture conditions. Labeled MSCs within SIS may assist tissue regeneration in augmentation cystoplasty but may not significantly incorporate into smooth muscle bundles.
Shukla
Dave
D
Department of Urology, University of California Irvine, 101 The City Dr. South, Bldg. 55, Rm. 300, Orange, CA 92868, USA.
Box
Geoffrey N
GN
Edwards
Robert A
RA
Tyson
Darren R
DR
D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology*; D002454:Cell Differentiation; D002455:Cell Division; D002469:Cell Separation; D002478:Cells, Cultured; D005260:Female; D005456:Fluorescent Dyes; D008164:Luminescent Proteins; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D032389:Myocytes, Smooth Muscle / Q000166:cytology*; D012038:Regeneration; D013552:Swine; D013556:Swine, Miniature; D023822:Tissue Engineering / Q000379:methods*; D001743:Urinary Bladder / Q000166:cytology* / Q000502:physiology; D019459:Urothelium / Q000166:cytology / Q000502:physiology
D005456:Fluorescent Dyes; D008164:Luminescent Proteins; C413663:fluorescent protein 583