title: Grp78 Is Critical for Amelogenin-Induced Cell Migration in a Multipotent Clonal Human Periodontal Ligament Cell Line.
abstract: Periodontal ligament stem cells (PDLSCs) are known to play a pivotal role in regenerating the periodontium. Amelogenin, which belongs to a family of extracellular matrix (ECM) proteins, is a potential bioactive molecule for periodontal regenerative therapy. However, its downstream target molecules and/or signaling patterns are still unknown. Our recent proteomic study identified glucose-regulated protein 78 (Grp78) as a new amelogenin-binding protein. In this study, we demonstrate, for the first time, the cellular responses induced by the biological interaction between amelogenin and Grp78 in the human undifferentiated PDL cell line 1-17, which possesses the most typical characteristics of PDLSCs. Confocal co-localization experiments revealed the internalization of recombinant amelogenin (rM180) via binding to cell surface Grp78, and the endocytosis was inhibited by the silencing of Grp78 in 1-17 cells. Microarray analysis indicated that rM180 and Grp78 regulate the expression profiles of cell migration-associated genes in 1-17 cells. Moreover, Grp78 overexpression enhanced rM180-induced cell migration and adhesion without affecting cell proliferation, while silencing of Grp78 diminished these activities. Finally, binding of rM180 to Grp78 promoted the formation of lamellipodia, and the simultaneous activation of Rac1 was also demonstrated by NSC23766, a widely accepted Rac1 inhibitor. These results suggest that Grp78 is essential for enhancing amelogenin-induced migration in 1-17 cells. The biological interaction of amelogenin with Grp78 offers significant therapeutic potential for understanding the biological components and specific functions involved in the signal transduction of amelogenin-induced periodontal tissue regeneration.
authors.affiliation: Department of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.
authors.forename: Kyosuke
authors.initials: K
authors.lastname: Toyoda
authors.affiliation: Department of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Fukuda
authors.affiliation: Department of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.
authors.forename: Terukazu
authors.initials: T
authors.lastname: Sanui
authors.affiliation: Department of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.
authors.forename: Urara
authors.initials: U
authors.lastname: Tanaka
authors.affiliation: Department of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.
authors.forename: Kensuke
authors.initials: K
authors.lastname: Yamamichi
authors.affiliation: Department of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Atomura
authors.affiliation: Department of Endodontology, Kyushu University Hospital, Fukuoka, Japan.
authors.forename: Hidefumi
authors.initials: H
authors.lastname: Maeda
authors.affiliation: Department of Endodontology, Kyushu University Hospital, Fukuoka, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Tomokiyo
authors.affiliation: Dental and Oral Medical Center, Kurume University School of Medicine, Kurume, Fukuoka, Japan.
authors.forename: Takaharu
authors.initials: T
authors.lastname: Taketomi
authors.affiliation: Department of Clinical Chemistry and Laboratory Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Uchiumi
authors.affiliation: Department of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.
authors.forename: Fusanori
authors.initials: F
authors.lastname: Nishimura
mesh_terms: D053523:Amelogenin / Q000502:physiology*; D002448:Cell Adhesion; D002460:Cell Line; D002465:Cell Movement / Q000235:genetics / Q000502:physiology*; D049109:Cell Proliferation; D004705:Endocytosis; D000091342:Endoplasmic Reticulum Chaperone BiP; D005786:Gene Expression Regulation; D016557:Guided Tissue Regeneration, Periodontal / Q000379:methods; D006360:Heat-Shock Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D006801:Humans; D039902:Multipotent Stem Cells / Q000166:cytology* / Q000502:physiology*; D010510:Periodontal Diseases / Q000628:therapy; D010513:Periodontal Ligament / Q000166:cytology* / Q000502:physiology; D011554:Pseudopodia / Q000502:physiology; D034741:RNA, Small Interfering / Q000235:genetics; D012038:Regeneration / Q000235:genetics / Q000502:physiology; D015398:Signal Transduction; D020830:rac1 GTP-Binding Protein / Q000502:physiology
chemical_list: D053523:Amelogenin; D000091342:Endoplasmic Reticulum Chaperone BiP; C000717247:HSPA5 protein, human; D006360:Heat-Shock Proteins; C107953:RAC1 protein, human; D034741:RNA, Small Interfering; D020830:rac1 GTP-Binding Protein