title: Isolation and characterization of human trophoblast side-population (SP) cells in primary villous cytotrophoblasts and HTR-8/SVneo cell line.
abstract: Recently, numerous studies have identified that immature cell populations including stem cells and progenitor cells can be found among "side-population" (SP) cells. Although SP cells isolated from some adult tissues have been reported elsewhere, isolation and characterization of human trophoblast SP remained to be reported. In this study, HTR-8/SVneo cells and human primary villous cytotrophoblasts (vCTBs) were stained with Hoechst 33342 and SP and non-SP (NSP) fractions were isolated using a cell sorter. A small population of SP cells was identified in HTR-8/SVneo cells and in vCTBs. SP cells expressed several vCTB-specific markers and failed to express syncytiotrophoblast (STB) or extravillous cytotrophopblast (EVT)-specific differentiation markers. SP cells formed colonies and proliferated on mouse embryonic fibroblast (MEF) feeder cells or in MEF conditioned medium supplemented with heparin/FGF2, and they also showed long-term repopulating property. SP cells could differentiate into both STB and EVT cell lineages and expressed several differentiation markers. Microarray analysis revealed that IL7R and IL1R2 were exclusively expressed in SP cells and not in NSP cells. vCTB cells sorted as positive for both IL7R and IL1R2 failed to express trophoblast differentiation markers and spontaneously differentiated into both STB and EVT in basal medium. These features shown by the SP cells suggested that IL7R and IL1R2 are available as markers to detect the SP cells and that vCTB progenitor cells and trophoblast stem cells were involved in the SP cell population.
authors.affiliation: Department of Obstetrics and Gynecology, Graduate School of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka, Japan.
authors.forename: Tomoka
authors.initials: T
authors.lastname: Takao
authors.forename: Kazuo
authors.initials: K
authors.lastname: Asanoma
authors.forename: Kiyoko
authors.initials: K
authors.lastname: Kato
authors.forename: Kotaro
authors.initials: K
authors.lastname: Fukushima
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Tsunematsu
authors.forename: Toshio
authors.initials: T
authors.lastname: Hirakawa
authors.forename: Sueo
authors.initials: S
authors.lastname: Matsumura
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Seki
authors.forename: Satoru
authors.initials: S
authors.lastname: Takeda
authors.forename: Norio
authors.initials: N
authors.lastname: Wake
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D002469:Cell Separation / Q000379:methods*; D017077:Culture Media, Conditioned / Q000494:pharmacology; D015536:Down-Regulation / Q000187:drug effects; D004622:Embryo, Mammalian / Q000166:cytology; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D051379:Mice; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000187:drug effects; D017472:Receptors, Interleukin-1 / Q000378:metabolism; D020395:Receptors, Interleukin-7 / Q000378:metabolism; D058985:Side-Population Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D014327:Trophoblasts / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D015415:Biomarkers; D017077:Culture Media, Conditioned; D017472:Receptors, Interleukin-1; D020395:Receptors, Interleukin-7