title: Stem cell therapy for erectile dysfunction: a critical review.
abstract: Erectile dysfunction (ED) is a prevailing health problem that seriously impacts quality of life. Current treatment options are less effective for patients having cavernous nerve (CN) injury or diabetes mellitus-related ED. These 2 types of ED are thus the main focus of past and current stem cell (SC) therapy studies. In a total of 16 studies so far, rats were exclusively used as disease models and SCs were mostly derived from bone marrow, adipose tissue, or skeletal muscle. For tracking, SCs were labeled with LacZ, green fluorescent protein, 4',6-diamidino-2-phenylindole, DiI, bromodeoxyuridine, or 5-ethynyl-2-deoxyuridine, some of which might have led to data misinterpretation. SC transplantation was done exclusively by intracavernous (IC) injection, which has been recently shown to have systemic effects. Functional assessment was done exclusively by measuring increases of IC pressure during electrostimulation of CN. Histological assessment usually focused on endothelial, smooth muscle, and CN contents in the penis. In general, favorable outcomes have been obtained in all trials so far, although whether SCs had differentiated into specific cell lineages remains controversial. Recent studies have shown that intracavernously injected SCs rapidly escaped the penis and homed into bone marrow. This could perhaps explain why intracavernously injected SCs had systemic antidiabetic effects and prolonged anti-ED effects. These hypotheses and the differentiation-versus-paracrine debate require further investigation.
authors.affiliation: Department of Urology, School of Medicine, University of California, San Francisco, California 94143-0738, USA. clin@urology.ucsf.edu
authors.forename: Ching-Shwun
authors.initials: CS
authors.lastname: Lin
authors.forename: Zhong-Cheng
authors.initials: ZC
authors.lastname: Xin
authors.forename: Zhong
authors.initials: Z
authors.lastname: Wang
authors.forename: Chunhua
authors.initials: C
authors.lastname: Deng
authors.forename: Yun-Ching
authors.initials: YC
authors.lastname: Huang
authors.forename: Guiting
authors.initials: G
authors.lastname: Lin
authors.forename: Tom F
authors.initials: TF
authors.lastname: Lue
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D019070:Cell Lineage; D002986:Clinical Trials as Topic; D004195:Disease Models, Animal; D004558:Electric Stimulation; D007172:Erectile Dysfunction / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D005456:Fluorescent Dyes; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D008297:Male; D010413:Penis / Q000503:physiopathology; D051381:Rats; D013194:Staining and Labeling; D033581:Stem Cell Transplantation / Q000009:adverse effects / Q000379:methods*; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*
chemical_list: D005456:Fluorescent Dyes; D049452:Green Fluorescent Proteins