Nephronectin Expression is Inhibited by Inorganic Phosphate in Osteoblasts
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Nephronectin (Npnt), an extracellular matrix protein, is known to be a ligand of integrin α8β1, and it has also been known to play critical roles as various organs. In the present study, elevated extracellular inorganic phosphate (Pi) strongly inhibited the expression of Npnt in MC3T3-E1 cells, while the existence of extracellular calcium (Ca) was indispensable for its effect. Furthermore, Pi-induced inhibition of Npnt gene expression was recovered by inhibitors of both sodium-dependent Pi transporter (Pit) and fibroblast growth factor receptors (Fgfrs). These results demonstrated that Npnt gene expression is regulated by extracellular Pi via Pit and Fgfrs.
KeywordsNephronectin Phosphate Calcium MC3T3-E1 FGFR
This work was supported in part by the Project to Establish Strategic Research Center for Innovative Dentistry by the Ministry of Education, Culture, Sports, Science and Technology of Japan (S1411009), the Private University Research Branding Project from MEXT of Japan, and Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (16K15782, 15H05016, 15K11051, 17K09737).
TK, AY, KS, KY, NM, HO, AS, and RK involved in study concept. AY, KS, and RK: involved in formal analysis; AY, HO, AS, and RK acquired funding; TK investigated the study; TK, AY, and RK applied methodology for the study; AY and RK administrated the project; HO, AS, and RK collected the resources; AY and RK supervised and validated the study; TK and AY wrote the original manuscript; TK, AY, and RK reviewed and edited the original manuscript.
Compliance with Ethical Standards
Conflict of interest
The authors declare that they have no conflicts of interest in regard to this study.
Human and Animal Rights and Informed Consent
All animal experiments were performed in accordance with the guide for care and use of laboratory animals and approved by the Showa University Animal Care Use and Committee.
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