Cited by 118Bone Metabolism and DiseasesBone health and osteoporosis researchCell death mechanisms and regulation

Apoptotic osteocytes regulate osteoclast precursor recruitment and differentiation in vitro

Open access
Al‐Dujaili, Saja A., Lau, Esther, Al‐Dujaili, Hashem, Tsang, Kyle, Guenther, Axel, You, Lidan·2011·Journal of Cellular Biochemistry

Abstract

Fatigue loading causes a spatial distribution of osteocyte apoptosis co‐localized with bone resorption spaces peaking around microdamage sites. Since osteocytes have been shown to regulate osteoclast formation and activity, we hypothesize that osteocyte apoptosis regulates osteoclastogenesis. In this study, we used serum‐starvation to mimic reduced nutrient transport in microdamaged bone and induce apoptosis in MLO‐Y4 osteocyte‐like cells; conditioned medium was used to apply soluble factors released by apoptotic osteocytes (aOCY) to healthy non‐apoptotic MLO‐Y4 cells. Osteoclast precursor (RAW264.7 monocyte) migration and differentiation were assessed in the presence of conditioned media (CM) from: (A) aOCY, (B) osteocytes treated with apoptosis conditioned medium (i.e., healthy osteocytes in the presence of apoptosis cues; apoptosis CM‐treated osteocytes (atOCY)), and (C) osteocytes treated with non‐apoptosis conditioned medium (i.e., healthy osteocytes in the absence of apoptosis cues; non‐apoptosis CM‐treated osteocytes (natOCY)). Receptor activator for nuclear factor‐κB ligand (RANKL), macrophage colony stimulating factor (M‐CSF), vascular endothelial growth factor (VEGF) and osteoprotegerin (OPG) mRNA, and protein expression were measured. Our findings indicate that soluble factors released by aOCY and atOCY promoted osteoclast precursor migration (up to 64% and 24% increase, respectively) and osteoclast formation (up to 450% and 265% increase, respectively). Osteoclast size increased up to 233% in the presence of aOCY and atOCY CM. Recruitment, formation and size were unaltered by natOCY. RANKL mRNA and protein expression were upregulated only in aOCY, while M‐CSF and VEGF increased in atOCY. Addition of RANKL‐blocking antibody abolished aOCY‐induced osteoclast precursor migration and osteoclast formation. VEGF and M‐CSF blocking antibodies abolished atOCY‐induced osteoclastogenesis. These findings suggest that aOCY directly and indirectly (through atOCY) initiate targeted bone resorption by regulating osteoclast precursor recruitment and differentiation. J. Cell. Biochem. 112: 2412–2423, 2011. © 2011 Wiley‐Liss, Inc.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1002/jcb.23164

Cites

47 of 47 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Conditioned media of apoptotic MLO-Y4 cells increased osteoclast formation, osteoclast size and osteoclast precursor migration; in apoptotic MLO-Y4 cells, both RANKL mRNA and protein expression were upregulated, suggesting that the conditioned media might contain sRANKL.

    “In a different study, the conditioned media of apoptotic MLO-Y4 cells increased osteoclast formation, osteoclast size and osteoclast precursor migration. Interestingly, in apoptotic MLO-Y4 cells, both RANKL mRNA and protein expression were upregulated, suggesting that the conditioned media of this cell culture might contain sRANKL.56”
  • Conditioned media of a non-apoptotic MLO-Y4 culture did not alter osteoclast formation, size or precursor migration.

    “On the other hand, the conditioned media of a non apoptotic MLO-Y4 culture did not alter any of these aforementioned cell parameters.56”

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

Flagged first, then by citations

Cited by

Sorted by citations

Authors
Al‐Dujaili, S. A., Lau, E., Al‐Dujaili, H., Tsang, K., Guenther, A., & You, L.
Affiliations
  • University of Toronto (CA)
  • Western University (CA)
Corresponding author
You, Lidan
Venue
Journal of Cellular Biochemistry
Publisher
Wiley
Published
2011-08-18
Volume
112
Issue
9
Pages
2412-2423
ISSN
  • 0730-2312 (ISSN-L)
  • 1097-4644
OpenAlex
W2038645339
Cited by
118
References
47
Citations by year
2026: 3 · 2025: 3 · 2024: 5 · 2023: 9 · 2022: 6 · 2021: 7 · 2020: 10 · 2019: 9 · 2018: 8 · 2017: 8 · 2016: 9 · 2015: 8 · 2014: 10 · 2013: 7 · 2012: 12
FWCI
4.15
Type
journal article
Language
en
Open access
Locations
  • Journal of Cellular Biochemistry (publishedVersion)
  • PubMed (publishedVersion)
Funders
  • University of Missouri
  • University of Toronto
  • Natural Sciences and Engineering Research Council of Canada (341704)
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Bone Metabolism and Diseases
  • Health Sciences › Medicine › Orthopedics and Sports Medicine › Bone health and osteoporosis research
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Cell death mechanisms and regulation
Keywords
osteocyte apoptosis, osteoclastogenesis, bone resorption, microdamage, RANKL, macrophage colony-stimulating factor, vascular endothelial growth factor, osteoprotegerin, soluble factors, MLO-Y4 cells, RAW 264.7 macrophages, fatigue loading
MeSH terms
Animals, Cell Differentiation, Cell Line, Cell Movement, Monocytes, Osteoclasts, Osteocytes, Up-Regulation, Gene Expression, Macrophage Colony-Stimulating Factor, Culture Media, Serum-Free, Culture Media, Conditioned, Apoptosis, Vascular Endothelial Growth Factor A, Cell Size, Mice, Osteoprotegerin, RANK Ligand

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review