title: Isoform-specific regulation of osteogenic factors by polypeptide N-Acetylgalactosaminyltransferases 1 and 4.
abstract: The family of UDP-GalNAc polypeptide: N-Acetylgalactosaminlytransfersases (ppGalNAcTs) catalyzes the initial step of O-linked protein glycosylation. Mucin-type O-glycoproteins are abundant in the bone and may play an important role in osteogenesis. Herein, we examined the effects of ppGalNAc-T isoforms on osteogenesis of MC3T3-E1 pre-osteoblasts. We found that ppGalNAc-T1 and -T4 isoforms were highly expressed during osteogenesis of MC3T3-E1 and their knockdown by short hairpin RNA (shRNA) decreased osteoblast formation and bone mineralization. Knockdown of ppGalNAc-T1 or -T4 decreased mRNA and protein levels of bone sialoprotein (BSP). Knockdown of ppGalNAc-T1decreased mRNA levels of osteocalcin (OC), osteoprotegerin (OPG). Knockdown ofppGalNAc-T4 isoform decreased mRNA levels of OC, OPG and vitamin D receptor (VDR). While knockdown of T1 or T4 isoforms did not change the expression of osteopontin (OPN), COLLI, receptor activator for nuclear factor-κB ligand (RANKL) and transforming growth factor-β (TGF-β). Our results demonstrated that the ppGalNAc-T4 was highly expressed in MC3T3-E1 cells during osteogenesis for the first time. We also found that ppGalNAc-T1 and -T4 affected the expression of different osteogenic factors, suggesting distinct roles ppGalNAc-T isoformsplay in regulating osteogenesis in vitro.
authors.affiliation: Department of Biochemistry and Molecular Biology, Soochow University Medical College, Suzhou, 215123, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Tang
authors.affiliation: Department of Biochemistry and Molecular Biology, Soochow University Medical College, Suzhou, 215123, China.
authors.forename: Hanxi
authors.initials: H
authors.lastname: Zheng
authors.affiliation: Department of Biochemistry and Molecular Biology, Soochow University Medical College, Suzhou, 215123, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Biochemistry and Molecular Biology, Soochow University Medical College, Suzhou, 215123, China.
authors.forename: Shangshang
authors.initials: S
authors.lastname: Gao
authors.affiliation: Department of Biochemistry and Molecular Biology, Soochow University Medical College, Suzhou, 215123, China.
authors.forename: Xiaorui
authors.initials: X
authors.lastname: Shi
authors.affiliation: Department of Biochemistry and Molecular Biology, Soochow University Medical College, Suzhou, 215123, China. Electronic address: liujingjing@suda.edu.cn.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Biochemistry and Molecular Biology, Soochow University Medical College, Suzhou, 215123, China. Electronic address: xulan@suda.edu.cn.
authors.forename: Lan
authors.initials: L
authors.lastname: Xu
mesh_terms: D016475:3T3 Cells; D000818:Animals; D002113:Calcification, Physiologic; D002384:Catalysis; D018929:Cell Culture Techniques; D002454:Cell Differentiation; D005786:Gene Expression Regulation; D058574:Integrin-Binding Sialoprotein / Q000378:metabolism; D051379:Mice; D017350:N-Acetylgalactosaminyltransferases / Q000378:metabolism*; D010006:Osteoblasts / Q000378:metabolism; D010012:Osteogenesis; D053495:Osteopontin / Q000378:metabolism; D010455:Peptides / Q000378:metabolism; D020033:Protein Isoforms / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D018167:Receptors, Calcitriol / Q000378:metabolism; D000097763:Polypeptide N-acetylgalactosaminyltransferase
chemical_list: D058574:Integrin-Binding Sialoprotein; D017350:N-Acetylgalactosaminyltransferases; D053495:Osteopontin; D010455:Peptides; D020033:Protein Isoforms; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D018167:Receptors, Calcitriol; D000097763:Polypeptide N-acetylgalactosaminyltransferase
keywords: MC3T3-E1 Sub14 pre-osteoblasts; Osteogenesis; UDP-GalNAc: polypeptide N-Acetylgalactosaminlytransfersases