title: Presence of stem/progenitor cells in the rat penis.
abstract: Tissue resident stem cells are believed to exist in every organ, and their identification is commonly done using a combination of immunostaining for putative stem cell markers and label-retaining cell (LRC) strategy. In this study, we employed these approaches to identify potential stem cells in the penis. Newborn rats were intraperitoneally injected with thymidine analog, 5-ethynyl-2-deoxyuridine (EdU), and their penis was harvested at 7 h, 3 days, 1 week, and 4 weeks. It was processed for EdU stains and immunofluorescence staining for stem cell markers A2B5, PCNA, and c-kit. EdU-positive cells were counted for each time point and co-localized with each stem cell marker, then isolated and cultured in vitro followed by their characterization using flowcytometry and immunofluorescence. At 7 h post-EdU injection, 410 ± 105.3 penile corporal cells were labeled in each cross-section (∼28%). The number of EdU-positive cells at 3 days increased to 536 ± 115.6, while their percentage dropped to 25%. Progressively fewer EdU-positive cells were present in the sacrificed rat penis at longer time points (1 and 4 weeks). They were mainly distributed in the subtunic and perisinusoidal spaces, and defined as subtunic penile progenitor cells (STPCs) and perisinusoidal penile progenitor cells (PPCs). These cells expressed c-kit, A2B5, and PCNA. After culturing in vitro, only ∼0.324% corporal cells were EdU-labeled LRCs and expressed A2B5/PCNA. Therefore, labeling of penis cells by EdU occurred randomly, and label retaining was not associated with expression of c-kit, A2B5, or PCNA. The penile LRCs are mainly distributed within the subtunic and perisinusoidal space.
authors.affiliation: 1 Knuppe Molecular Urology Laboratory, Department of Urology, School of Medicine, University of California , San Francisco, San Francisco, California.
authors.forename: Guiting
authors.initials: G
authors.lastname: Lin
authors.forename: Amjad
authors.initials: A
authors.lastname: Alwaal
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Zhang
authors.forename: Jianwen
authors.initials: J
authors.lastname: Wang
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.forename: Huixi
authors.initials: H
authors.lastname: Li
authors.forename: Guifang
authors.initials: G
authors.lastname: Wang
authors.forename: Hongxiu
authors.initials: H
authors.lastname: Ning
authors.forename: Ching-Shwun
authors.initials: CS
authors.lastname: Lin
authors.forename: Zhongcheng
authors.initials: Z
authors.lastname: Xin
authors.forename: Tom F
authors.initials: TF
authors.lastname: Lue
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000943:Antigens, Differentiation / Q000096:biosynthesis*; D002469:Cell Separation; D005786:Gene Expression Regulation / Q000502:physiology*; D008297:Male; D010413:Penis / Q000166:cytology* / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism*
chemical_list: D000943:Antigens, Differentiation