title: GPNMB promotes proliferation of developing eosinophils.
abstract: Glycoprotein non-metastatic melanoma protein B (GPNMB) is a type I transmembrane protein that is expressed in a wide variety of cell types, including haematopoietic lineages. We previously demonstrated that GPNMB is one of the most highly expressed genes at an early and intermediate stage of eosinophil development. We herein examined GPNMB expression and its possible functional effect using cord blood (CB) CD34+ haematopoietic stem cells differentiating toward eosinophils during a 24-day culture period. Western blot and confocal microscopy analyses showed that GPNMB reached its highest levels at day 12 with most GPNMB-positive cells also expressing major basic protein 1 (MBP1), an eosinophil granule protein. GPNMB declined thereafter, but was still present at an appreciable level at day 24, the time when CB eosinophils most abundantly expressed MBP1 and were thus considered fully differentiated. When the developing CB cells were cultured in the presence of a blocking anti-GPNMB antibody, cell proliferation was significantly reduced. In agreement, ectopic expression of GPNMB in heterologous cells resulted in a significant increase in cell proliferation, while small interfering RNA of GPNMB inhibited the GPNMB-mediated proliferation. Thus, GPNMB is expressed in a temporal manner during eosinophil development and delivers a proliferative signal upon activation.
authors.affiliation: Department of Bionano Technology, Hanyang University.
authors.forename: Sae Mi
authors.initials: SM
authors.lastname: Hwang
authors.affiliation: Department of Molecular and Life Sciences, College of Science and Technology, Hanyang University, Ansan, Gyeonggi-do, Republic of Korea.
authors.forename: Jin Hyun
authors.initials: JH
authors.lastname: Kang
authors.affiliation: Department of Bionano Technology, Hanyang University.
authors.forename: Bo Kyum
authors.initials: BK
authors.lastname: Kim
authors.affiliation: Department of Molecular and Life Sciences, College of Science and Technology, Hanyang University, Ansan, Gyeonggi-do, Republic of Korea.
authors.forename: Tae Gi
authors.initials: TG
authors.lastname: Uhm
authors.affiliation: Department of Molecular and Life Sciences, College of Science and Technology, Hanyang University, Ansan, Gyeonggi-do, Republic of Korea.
authors.forename: Hye Jeong
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Bioscience and Biotechnology and Protein Research Center of GRRC, College of Natural Sciences, Hankuk University of Foreign Studies, Yongin, Gyeonggi-do 449-791, Republic of Korea.
authors.forename: Hyune-Hwan
authors.initials: HH
authors.lastname: Lee
authors.affiliation: Department of Molecular and Life Sciences, College of Science and Technology, Hanyang University, Ansan, Gyeonggi-do, Republic of Korea.
authors.forename: Bert
authors.initials: B
authors.lastname: Binas
authors.affiliation: Department of Bionano Technology, Hanyang University.|Department of Molecular and Life Sciences, College of Science and Technology, Hanyang University, Ansan, Gyeonggi-do, Republic of Korea.
authors.forename: Il Yup
authors.initials: IY
authors.lastname: Chung
mesh_terms: D049109:Cell Proliferation; D002478:Cells, Cultured; D004804:Eosinophils / Q000166:cytology* / Q000378:metabolism; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*
chemical_list: C503042:GPNMB protein, human; D008562:Membrane Glycoproteins
keywords: GPNMB; MBP; cord blood; eosinophils; proliferation