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Osteoblastic lysosome plays a central role in mineralization.

ABSTRACT: Mineralization is the most fundamental process in vertebrates. It is predominantly mediated by osteoblasts, which secrete mineral precursors, most likely through matrix vesicles (MVs). These vesicular structures are calcium and phosphate rich and contain organic material such as acidic proteins. However, it remains largely unknown how intracellular MVs are transported and secreted. Here, we use scanning electron-assisted dielectric microscopy and super-resolution microscopy for assessing live osteoblasts in mineralizing conditions at a nanolevel resolution. We found that the calcium-containing vesicles were multivesicular bodies containing MVs. They were transported via lysosome and secreted by exocytosis. Thus, we present proof that the lysosome transports amorphous calcium phosphate within mineralizing osteoblasts.

SUBMITTER: Iwayama T

PROVIDER: S-EPMC6609213 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature

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Osteoblastic lysosome plays a central role in mineralization.

Iwayama Tomoaki T Okada Tomoko T Ueda Tsugumi T Tomita Kiwako K Matsumoto Shuji S Takedachi Masahide M Wakisaka Satoshi S Noda Takeshi T Ogura Taku T Okano Tomomichi T Fratzl Peter P Ogura Toshihiko T Murakami Shinya S

Science advances 20190703 7

Mineralization is the most fundamental process in vertebrates. It is predominantly mediated by osteoblasts, which secrete mineral precursors, most likely through matrix vesicles (MVs). These vesicular structures are calcium and phosphate rich and contain organic material such as acidic proteins. However, it remains largely unknown how intracellular MVs are transported and secreted. Here, we use scanning electron-assisted dielectric microscopy and super-resolution microscopy for assessing live os ...[more]

PMID: 31281900

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