Dataset Information

Fyn promotes proliferation, differentiation, survival and function of osteoclast lineage cells.

ABSTRACT: c-Src and Lyn are the only Src family kinases (SFKs) with established activity in osteoclasts (OCs). c-Src promotes function via cytoskeletal organization of the mature resorptive cell while Lyn is a negative regulator of osteoclastogenesis. We establish that Fyn, another SFK, also impacts the OC, but in a manner distinctly different than c-Src and Lyn. Fyn deficiency principally alters cells throughout the osteoclastogenic process, resulting in diminished numbers of resorptive polykaryons. Arrested OC formation in the face of insufficient Fyn reflects reduced proliferation of precursors, in response to M-CSF and retarded RANK ligand (RANKL)-induced differentiation, attended by suppressed activation of the osteoclastogenic signaling molecules, c-Jun, and NF-?B. The anti-apoptotic properties of RANKL are also compromised in cells deleted of Fyn, an event mediated by increased Bim expression and failed activation of Akt. The defective osteoclastogenesis of Fyn-/- OCs dampens bone resorption, in vitro. Finally, while Fyn deficiency does not regulate basal osteoclastogenesis, in vivo, it reduces that stimulated by RANKL by ~2/3. Thus, Fyn is a pro-resorptive SFK, which exerts its effects by prompting proliferation and differentiation while attenuating apoptosis of OC lineage cells.

SUBMITTER: Kim HJ

PROVIDER: S-EPMC3719388 | biostudies-literature | 2010 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Fyn promotes proliferation, differentiation, survival and function of osteoclast lineage cells.

Kim Hyun-Ju HJ Warren Julia T JT Kim Shin-Yoon SY Chappel Jean C JC DeSelm Carl J CJ Ross F Patrick FP Zou Wei W Teitelbaum Steven L SL

Journal of cellular biochemistry 20101201 5

c-Src and Lyn are the only Src family kinases (SFKs) with established activity in osteoclasts (OCs). c-Src promotes function via cytoskeletal organization of the mature resorptive cell while Lyn is a negative regulator of osteoclastogenesis. We establish that Fyn, another SFK, also impacts the OC, but in a manner distinctly different than c-Src and Lyn. Fyn deficiency principally alters cells throughout the osteoclastogenic process, resulting in diminished numbers of resorptive polykaryons. Arre ...[more]

PMID: 20717919

Similar Datasets

Project description:It has been shown that high vitamin A intake is associated with bone fragility and fractures in both animals and humans. However, the mechanism by which vitamin A affects bones is unclear. In the present study, the direct effects of retinoic acid (RA) on human and murine osteoclastogenesis were evaluated using cultured peripheral blood CD14(+) monocytes and RAW264.7 cells. Both the activity of the osteoclast marker tartrate resistant acid phosphatase (TRAP) in culture supernatant and the expression of the genes involved in osteoclast differentiation together with bone resorption were measured. To our knowledge, this is the first time that the effects of RA on human osteoclast progenitors and mature osteoclasts have been studied in vitro. RA stimulated proliferation of osteoclast progenitors both from humans and mice. In contrast, RA inhibited differentiation of the receptor activator of nuclear factor ?B ligand (RANKL)-induced osteoclastogenesis of human and murine osteoclast progenitors via retinoic acid receptors (RARs). We also show that the mRNA levels of receptor activator of nuclear factor ?B (RANK), the key initiating factor and osteoclast associated receptor for RANKL, were potently suppressed by RA in osteoclast progenitors. More importantly, RA abolished the RANK protein in osteoclast progenitors. This inhibition could be partially reversed by a RAR pan-antagonist. Furthermore, RA treatment suppressed the expression of the transcription factor nuclear factor of activated T-cells cytoplasmic 1 (NFATc1) and increased the expression of interferon regulatory factor-8 (IRF-8) in osteoclast progenitors via RARs. Also, RA demonstrated differential effects depending on the material supporting the cell culture. RA did not affect TRAP activity in the culture supernatant in the bone slice culture system, but inhibited the release of TRAP activity if cells were cultured on plastic. In conclusion, our results suggest that retinoic acid increases proliferation of human osteoclast progenitors and that it inhibits RANK-stimulated osteoclast differentiation by suppressing RANK.

Project description:BACKGROUND:Lymphotoxin (LT) is a lymphokine mainly expressed in lymphocytes. LT? binds one or two membrane-associated LT? to form LT?2?1 or LT?1?2 heterotrimers. The predominant LT?1?2 binds to LT? receptor (LT?R) primarily expressed in epithelial and stromal cells. Most studies on LT?R signaling have focused on the organization, development, and maintenance of lymphoid tissues. However, the roles of LT?R signaling in the nervous system, particularly in neurogenesis, remain unknown. Here, we investigated the role of LT?R-mediated NF?B signaling in regulating neural lineage differentiation. METHODS:The C57BL/6J wild-type and GFAP-dnI?B? transgenic mice were used. Serum-free embryoid bodies were cultured from mouse embryonic stem cells and further induced into neural stem/progenitor cells (NSCs/NPCs). Primary neurospheres were cultured from embryonic and adult mouse brains followed by monolayer culture for amplification/passage. NF?B activation was determined by adenovirus-mediated NF?B-firefly-luciferase reporter assay and p65/RelB/p52 nuclear translocation assay. LT?R mRNA expression was evaluated by quantitative RT-PCR and LT?R protein expression was determined by immunohistochemistry and Western blot analysis. Multilabeled immunocytochemistry or immunohistochemistry followed by fluorescent confocal microscopy and quantitative analysis of neural lineage differentiation were performed. Graphing and statistical analysis were performed with GraphPad Prism software. RESULTS:In cultured NSCs/NPCs, LT?1?2 stimulation induced an activation of classical and non-classical NF?B signaling. The expression of LT?R-like immunoreactivity in GFAP+/Sox2+ NSCs was identified in well-established neurogenic zones of adult mouse brain. Quantitative RT-PCR and Western blot analysis validated the expression of LT?R in cultured NSCs/NPCs and brain neurogenic regions. LT?R expression was significantly increased during neural induction. LT?1?2 stimulation in cultured NSCs/NPCs promoted astroglial and oligodendrocytic lineage differentiation, but inhibited neuronal lineage differentiation. Astroglial NF?B inactivation in GFAP-dnI?B? transgenic mice rescued LT?R-mediated abnormal phenotypes of cultured NSCs/NPCs. CONCLUSION:This study provides the first evidence for the expression and function of LT?R signaling in NSCs/NPCs. Activation of LT?R signaling promotes glial lineage differentiation. Our results suggest that neurogenesis is regulated by the adaptive immunity and inflammatory responses.

Dataset Information

Fyn promotes proliferation, differentiation, survival and function of osteoclast lineage cells.

Publications

Fyn promotes proliferation, differentiation, survival and function of osteoclast lineage cells.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure