TY - JOUR
T1 - The Rho-specific guanine nucleotide exchange factor Plekhg5 modulates cell polarity, adhesion, migration, and podosome organization in macrophages and osteoclasts
AU - Iwatake, Mayumi
AU - Nishishita, Kazuhisa
AU - Okamoto, Kuniaki
AU - Tsukuba, Takayuki
N1 - Funding Information:
This work was supported by JSPS KAKENHI (Grants-in-Aid for Scientific Research) Grant Numbers 15H05298 , 16K15790 , 16K11863 , 16K11510 , and 16H00687 .
Publisher Copyright:
© 2017 Elsevier Inc.
PY - 2017/10/15
Y1 - 2017/10/15
N2 - Osteoclasts are multinucleated bone-resorbing cells that are formed by fusion of monocyte/macrophage lineage. Osteoclasts and macrophages generate podosomes that are actin-based dynamic organelles implicated in cell adhesion, spreading, migration, and degradation. However, the detailed mechanisms of podosome organization remain unknown. Here, we identified the Rho-specific guanine-nucleotide exchange factor (Rho-GEF) Plekhg5 as an up-regulated gene during differentiation of osteoclasts from macrophages. Knockdown of Plekhg5 with small interfering RNA in both macrophages and osteoclasts induced larger cell formation with impaired cell polarity and resulted in an elongated and flattened shape. In macrophages, Plekhg5 depletion enhanced random migration, but impaired directional migration, adhesion, and matrix degradation. Plekhg5 in osteoclasts affected random migration, podosome organization, and bone resorption. Plekhg5 depletion affected signaling and localization of several Rho downstream effectors. In fact, end-binding protein 1 (EB1), cofilin and vinculin were abnormally localized in Plekhg5-depleted cells, and mDia1 and LIM kinase (LIMK)1 were upregulated in Plekhg5-depleted cells compared with control cells. However, overexpression of Plekhg5 in macrophages induced an increase in its mRNA level, but failed to increase the protein level, indicating that overexpressed Plekhg5 was degraded in macrophages but not HEK293T cells. Thus, Plekhg5 affects cell polarity, migration, adhesion, degradation, and podosome organization in macrophages and osteoclasts.
AB - Osteoclasts are multinucleated bone-resorbing cells that are formed by fusion of monocyte/macrophage lineage. Osteoclasts and macrophages generate podosomes that are actin-based dynamic organelles implicated in cell adhesion, spreading, migration, and degradation. However, the detailed mechanisms of podosome organization remain unknown. Here, we identified the Rho-specific guanine-nucleotide exchange factor (Rho-GEF) Plekhg5 as an up-regulated gene during differentiation of osteoclasts from macrophages. Knockdown of Plekhg5 with small interfering RNA in both macrophages and osteoclasts induced larger cell formation with impaired cell polarity and resulted in an elongated and flattened shape. In macrophages, Plekhg5 depletion enhanced random migration, but impaired directional migration, adhesion, and matrix degradation. Plekhg5 in osteoclasts affected random migration, podosome organization, and bone resorption. Plekhg5 depletion affected signaling and localization of several Rho downstream effectors. In fact, end-binding protein 1 (EB1), cofilin and vinculin were abnormally localized in Plekhg5-depleted cells, and mDia1 and LIM kinase (LIMK)1 were upregulated in Plekhg5-depleted cells compared with control cells. However, overexpression of Plekhg5 in macrophages induced an increase in its mRNA level, but failed to increase the protein level, indicating that overexpressed Plekhg5 was degraded in macrophages but not HEK293T cells. Thus, Plekhg5 affects cell polarity, migration, adhesion, degradation, and podosome organization in macrophages and osteoclasts.
KW - Cell migration
KW - Cell polarity
KW - Macrophage
KW - Osteoclast
KW - Podosome
KW - Rho-GEF
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U2 - 10.1016/j.yexcr.2017.08.025
DO - 10.1016/j.yexcr.2017.08.025
M3 - Article
C2 - 28847484
AN - SCOPUS:85028608623
VL - 359
SP - 415
EP - 430
JO - Experimental Cell Research
JF - Experimental Cell Research
SN - 0014-4827
IS - 2
ER -