Methods and insights from the characterization of osteoprogenitor cells of bats (Mammalia: Chiroptera).
Animals; Bone Marrow Cells/cytology; Cell Differentiation/genetics; Cell Proliferation; Cells; Cellular Reprogramming; Chiroptera; Core Binding Factor Alpha 1 Subunit/genetics/metabolism; Cultured; Inbred C57BL; Mice; Osteoblasts/cytology/*metabolism; Osteocalcin/genetics/metabolism; Osteogenesis/*genetics; Real-Time Polymerase Chain Reaction; Stem Cells/*cytology/metabolism; Transcription Factors/genetics/metabolism
Osteoprogenitor cells contribute to the development and maintenance of skeletal tissues. Bats are unique model taxa whose cellular processes are poorly understood, especially in regards to skeletal biology. Forelimb bones of bats, unlike those of terrestrial mammals, bend during flight and function in controlled deformation. As a first step towards understanding the molecular processes governing deposition of this flexible bone matrix, we provide the first method for isolation and differentiation of cell populations derived from the bone marrow and cortical bone of bats, and compare results with those harvested from C57BL/6J mice. Osteogenic capacity of these cells was assessed via absolute quantitative real-time PCR (qPCR) and through quantification of in vitro mineral deposition. Results indicate the differentiated bone cells of bats display significantly lower gene expression of known osteogenic markers (Runt-related transcription factor (RUNX2), osteocalcin (BGLAP) and osterix (SP7)), and deposit a less-mineralized matrix compared with murine controls. By characterizing the in vitro performance of osteoprogenitor cells throughout differentiation and matrix production, this study lays the ground work for in vitro manipulations of bat stem and osteoprogenitor cells and extends our understanding of the cellular diversity across mammals that occupy different habitats.
Ball H C; Moussa F M; Mbimba T; Orman R; Safadi F F; Cooper L N
Stem cell research
2016
2016-07
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1016/j.scr.2016.05.009" target="_blank" rel="noreferrer noopener">10.1016/j.scr.2016.05.009</a>
Mutation in osteoactivin decreases bone formation in vivo and osteoblast differentiation in vitro.
*Signal Transduction; Alkaline Phosphatase/metabolism; Animals; Apoptosis; Bone and Bones/metabolism/pathology; Cell Differentiation/genetics; Eye Proteins/*genetics; Inbred DBA; Male; Membrane Glycoproteins/*genetics; Mice; Mutation; Newborn; Osteoblasts/cytology/*physiology; Osteocalcin/*genetics; Osteogenesis/*genetics; Phenotype; Receptors; Transforming Growth Factor beta/metabolism
We have previously identified osteoactivin (OA), encoded by Gpnmb, as an osteogenic factor that stimulates osteoblast differentiation in vitro. To elucidate the importance of OA in osteogenesis, we characterized the skeletal phenotype of a mouse model, DBA/2J (D2J) with a loss-of-function mutation in Gpnmb. Microtomography of D2J mice showed decreased trabecular mass, compared to that in wild-type mice [DBA/2J-Gpnmb(+)/SjJ (D2J/Gpnmb(+))]. Serum analysis showed decreases in OA and the bone-formation markers alkaline phosphatase and osteocalcin in D2J mice. Although D2J mice showed decreased osteoid and mineralization surfaces, their osteoblasts were increased in number, compared to D2J/Gpnmb(+) mice. We then examined the ability of D2J osteoblasts to differentiate in culture, where their differentiation and function were decreased, as evidenced by low alkaline phosphatase activity and matrix mineralization. Quantitative RT-PCR analyses confirmed the decreased expression of differentiation markers in D2J osteoblasts. In vitro, D2J osteoblasts proliferated and survived significantly less, compared to D2J/Gpnmb(+) osteoblasts. Next, we investigated whether mutant OA protein induces endoplasmic reticulum stress in D2J osteoblasts. Neither endoplasmic reticulum stress markers nor endoplasmic reticulum ultrastructure were altered in D2J osteoblasts. Finally, we assessed underlying mechanisms that might alter proliferation of D2J osteoblasts. Interestingly, TGF-beta receptors and Smad-2/3 phosphorylation were up-regulated in D2J osteoblasts, suggesting that OA contributes to TGF-beta signaling. These data confirm the anabolic role of OA in postnatal bone formation.
Abdelmagid Samir M; Belcher Joyce Y; Moussa Fouad M; Lababidi Suzanne L; Sondag Gregory R; Novak Kimberly M; Sanyurah Afif S; Frara Nagat A; Razmpour Roshanak; Del Carpio-Cano Fabiola E; Safadi Fayez F
The American journal of pathology
2014
2014-03
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1016/j.ajpath.2013.11.031" target="_blank" rel="noreferrer noopener">10.1016/j.ajpath.2013.11.031</a>