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Ablation of the mammalian lectin galectin‐8 induces bone defects in mice
Author(s) -
Vinik Yaron,
ShatzAzoulay Hadas,
HiramBab Sahar,
Kandel Leonid,
Gabet Yankel,
Rivkin Gurion,
Zick Yehiel
Publication year - 2018
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fj.201700716r
Subject(s) - endocrinology , medicine , osteoblast , chemistry , rankl , sclerostin , bone remodeling , bone morphogenetic protein 2 , dmp1 , osteopontin , osteocalcin , bone mineral , osteoporosis , receptor , alkaline phosphatase , microbiology and biotechnology , biology , activator (genetics) , signal transduction , wnt signaling pathway , biochemistry , viral matrix protein , gene , in vitro , enzyme
Mice overexpressing galectin‐8 [gal‐8 transgenic (Tg)], a secreted mammalian lectin, exhibit enhanced bone turnover and reduced bone mass, similar to cases of postmenopausal osteoporosis. Here, we show that gal‐8 knockout (KO) mice have increased bone mass accrual at a young age but exhibit accelerated bone loss during adulthood. These phenotypes can be attributed to a gal‐8‐mediated increase in receptor activator of NF‐κB ligand (RANKL) expression that promotes osteoclastogenesis, combined with direct inhibition of osteoblast differentiation, evident by reduced bone morphogenetic protein (BMP) signaling, reduced phosphorylation of receptor regulated mothers against decapentaplegic homolog (R‐SMAD) and reduced expression of osteoblast differentiation markers osterix, osteocalcin, runt‐related transcription factor 2 (RUNX2), dentin matrix acidic phosphoprotein‐1 (DMP1), and alkaline phosphatase. At the same time, gal‐8 promotes expression of estrogen receptor a (ESR1). Accordingly, the rate of bone loss is accelerated in ovariectomized, estrogen‐deficient gal‐8 Tg mice, whereas gal‐8 KO mice, having low levels of ESR1, are refractory to ovariectomy. Finally, gal‐8 mRNA positively correlates with the mRNA levels of osteoclastogenic markers RANKL, tartrate‐resistant acid phosphatase, and cathepsin K in human femurs. Collectively, these findings identify gal‐8 as a new physiologic player in the regulation of bone mass.—Vinik, Y., Shatz‐Azoulay, H., Hiram‐Bab, S., Kandel, L., Gabet, Y., Rivkin, G., Zick, Y. Ablation of the mammalian lectin galectin‐8 induces bone defects in mice. FASEB J. 32, 2366–2380 (2018). www.fasebj.org