title: Membrane vesicles nucleate mineralo-organic nanoparticles and induce carbonate apatite precipitation in human body fluids.
abstract: Recent studies indicate that membrane vesicles (MVs) secreted by various cells are associated with human diseases, including arthritis, atherosclerosis, cancer, and chronic kidney disease. The possibility that MVs may induce the formation of mineralo-organic nanoparticles (NPs) and ectopic calcification has not been investigated so far. Here, we isolated MVs ranging in size between 20 and 400 nm from human serum and FBS using ultracentrifugation and sucrose gradient centrifugation. The MV preparations consisted of phospholipid-bound vesicles containing the serum proteins albumin, fetuin-A, and apolipoprotein A1; the mineralization-associated enzyme alkaline phosphatase; and the exosome proteins TNFR1 and CD63. Notably, we observed that MVs induced mineral precipitation following inoculation and incubation in cell culture medium. The mineral precipitates consisted of round, mineralo-organic NPs containing carbonate hydroxyapatite, similar to previous descriptions of the so-called nanobacteria. Annexin V-immunogold staining revealed that the calcium-binding lipid phosphatidylserine (PS) was exposed on the external surface of serum MVs. Treatment of MVs with an anti-PS antibody significantly decreased their mineral seeding activity, suggesting that PS may provide nucleating sites for calcium phosphate deposition on the vesicles. These results indicate that MVs may represent nucleating agents that induce the formation of mineral NPs in body fluids. Given that mineralo-organic NPs represent precursors of calcification in vivo, our results suggest that MVs may initiate ectopic calcification in the human body.
authors.affiliation: From the Laboratory of Nanomaterials,; the Center for Molecular and Clinical Immunology, and; the Research Center of Bacterial Pathogenesis, Chang Gung University, Gueishan, Taoyuan 333, Taiwan.
authors.forename: Cheng-Yeu
authors.initials: CY
authors.lastname: Wu
authors.affiliation: From the Laboratory of Nanomaterials,; the Center for Molecular and Clinical Immunology, and.
authors.forename: Jan
authors.initials: J
authors.lastname: Martel
authors.affiliation: From the Laboratory of Nanomaterials,; the Center for Molecular and Clinical Immunology, and.
authors.forename: Wei-Yun
authors.initials: WY
authors.lastname: Cheng
authors.affiliation: From the Laboratory of Nanomaterials,; the Center for Molecular and Clinical Immunology, and.
authors.forename: Chao-Chih
authors.initials: CC
authors.lastname: He
authors.affiliation: the Center for Molecular and Clinical Immunology, and; the Molecular Cell Biology, Health Sciences Research Institute, University of California, Merced, California 95343.
authors.forename: David M
authors.initials: DM
authors.lastname: Ojcius
authors.affiliation: From the Laboratory of Nanomaterials,; the Center for Molecular and Clinical Immunology, and; the Laboratory of Cellular Physiology and Immunology, Rockefeller University, New York, New York 10021, and; the Biochemical Engineering Research Center, Ming Chi University of Technology, Taishan, Taipei 24301, Taiwan. Electronic address: dingeyoung@hotmail.com.
authors.forename: John D
authors.initials: JD
authors.lastname: Young
mesh_terms: D000469:Alkaline Phosphatase / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D017304:Annexin A5 / Q000737:chemistry / Q000378:metabolism; D001798:Blood Proteins / Q000737:chemistry* / Q000378:metabolism; D002114:Calcinosis; D002417:Cattle; D055252:Cell-Derived Microparticles / Q000737:chemistry* / Q000378:metabolism; D017886:Durapatite / Q000737:chemistry* / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D010718:Phosphatidylserines / Q000737:chemistry / Q000378:metabolism; D047888:Receptors, Tumor Necrosis Factor, Type I / Q000737:chemistry / Q000378:metabolism; D060149:Tetraspanin 30 / Q000737:chemistry / Q000378:metabolism
chemical_list: D017304:Annexin A5; D001798:Blood Proteins; C554586:CD63 protein, human; D010718:Phosphatidylserines; D047888:Receptors, Tumor Necrosis Factor, Type I; D060149:Tetraspanin 30; D017886:Durapatite; D000469:Alkaline Phosphatase
keywords: Atherosclerosis; Biomineralization; Calcification; Calcium; Ectopic Calcification; Membrane Vesicles; Nanobacteria; Phosphatidylserine