論文

国際誌
2020年10月31日

Rab11A Functions as a Negative Regulator of Osteoclastogenesis through Dictating Lysosome-Induced Proteolysis of c-fms and RANK Surface Receptors.

Cells
  • Yuka Okusha
  • ,
  • Manh Tien Tran
  • ,
  • Mami Itagaki
  • ,
  • Chiharu Sogawa
  • ,
  • Takanori Eguchi
  • ,
  • Tatsuo Okui
  • ,
  • Tomoko Kadowaki
  • ,
  • Eiko Sakai
  • ,
  • Takayuki Tsukuba
  • ,
  • Kuniaki Okamoto

9
11
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.3390/cells9112384

Osteoclast differentiation and activity are controlled by two essential cytokines, macrophage colony-stimulating factor (M-CSF) and the receptor activator of nuclear factor-κB ligand (RANKL). Rab11A GTPase, belonging to Rab11 subfamily representing the largest branch of Ras superfamily of small GTPases, has been identified as one of the crucial regulators of cell surface receptor recycling. Nevertheless, the regulatory role of Rab11A in osteoclast differentiation has been completely unknown. In this study, we found that Rab11A was strongly upregulated at a late stage of osteoclast differentiation derived from bone marrow-derived macrophages (BMMs) or RAW-D murine osteoclast precursor cells. Rab11A silencing promoted osteoclast formation and significantly increased the surface levels of c-fms and receptor activator of nuclear factor-κB (RANK) while its overexpression attenuated osteoclast formation and the surface levels of c-fms and RANK. Using immunocytochemical staining for tracking Rab11A vesicular localization, we observed that Rab11A was localized in early and late endosomes, but not lysosomes. Intriguingly, Rab11A overexpression caused the enhancement of fluorescent intensity and size-based enlargement of early endosomes. Besides, Rab11A overexpression promoted lysosomal activity via elevating the endogenous levels of a specific lysosomal protein, LAMP1, and two key lysosomal enzymes, cathepsins B and D in osteoclasts. More importantly, inhibition of the lysosomal activity by chloroquine, we found that the endogenous levels of c-fms and RANK proteins were enhanced in osteoclasts. From these observations, we suggest a novel function of Rab11A as a negative regulator of osteoclastogenesis mainly through (i) abolishing the surface abundance of c-fms and RANK receptors, and (ii) upregulating lysosomal activity, subsequently augmenting the degradation of c-fms and RANK receptors, probably via the axis of early endosomes-late endosomes-lysosomes in osteoclasts.

リンク情報
DOI
https://doi.org/10.3390/cells9112384
PubMed
https://www.ncbi.nlm.nih.gov/pubmed/33142674
PubMed Central
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7692573
ID情報
  • DOI : 10.3390/cells9112384
  • PubMed ID : 33142674
  • PubMed Central 記事ID : PMC7692573

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