Lipid microenvironment affects the ability of proteoliposomes harboring TNAP to induce mineralization without nucleators

• Published in: Journal of bone and mineral metabolism Vol. 37; no. 4; pp. 607 - 613
• Main Authors: Simão, Ana Maria Sper, Bolean, Maytê, Favarin, Bruno Zoccaratto, Veschi, Ekeveliny Amabile, Tovani, Camila Bussola, Ramos, Ana Paula, Bottini, Massimo, Buchet, Rene, Millán, José Luis, Ciancaglini, Pietro
• Format: Journal Article
• Language: English
• Published: Tokyo Springer Japan 01.07.2019; Springer Nature B.V; Springer Verlag
• Subjects: Adenosine Triphosphate - metabolism; Alkaline phosphatase; Alkaline Phosphatase - metabolism; Animals; Apatite; Biochemistry; Biochemistry, Molecular Biology; Calcification, Physiologic; Calcium phosphates; Cellular Microenvironment; Cholesterol; Dynamic Light Scattering; Glycosylphosphatidylinositol; Humans; Hydrolysis; Kinetics; Life Sciences; Lipid composition; Lipids; Lipids - chemistry; Matrix vesicles; Medicine; Medicine & Public Health; Membrane vesicles; Metabolic Diseases; Mineralization; Molecular biology; Original Article; Orthopedics; Phosphatidylserine; Phosphocholine; Proteolipids - metabolism; Spectroscopy, Fourier Transform Infrared; Sphingomyelin; Turbidity; Biomineralization; Alkaline phosphatase; Proteoliposome; Nucleational core; Matrix vesicles
• ISSN: 0914-8779; 1435-5604
• DOI: 10.1007/s00774-018-0962-8

Tissue-nonspecific alkaline phosphatase (TNAP), a glycosylphosphatidylinositol-anchored ectoenzyme present on the membrane of matrix vesicles (MVs), hydrolyzes the mineralization inhibitor inorganic pyrophosphate as well as ATP to generate the inorganic phosphate needed for apatite formation. Herein, we used proteoliposomes harboring TNAP as MV biomimetics with or without nucleators of mineral formation (amorphous calcium phosphate and complexes with phosphatidylserine) to assess the role of the MVs’ membrane lipid composition on TNAP activity by means of turbidity assay and FTIR analysis. We found that TNAP-proteoliposomes have the ability to induce mineralization even in the absence of mineral nucleators. We also found that the addition of cholesterol or sphingomyelin to TNAP-proteoliposomes composed of 1,2-dipalmitoyl- sn -glycero-3-phosphocholine reduced the ability of TNAP to induce biomineralization. Our results suggest that the lipid microenvironment is essential for the induction and propagation of minerals mediated by TNAP.