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Lorenz, J.* ; Richter, S.* ; Kirstein, A.S.* ; Kolbig, F.* ; Nebe, M.* ; Schulze, M.* ; Kiess, W.* ; Spitzbarth, I.* ; Klöting, N. ; Le Duc, D.* ; Baschant, U.* ; Garten, A.*

Pten knockout in mouse preosteoblasts leads to changes in bone turnover and strength.

JBMR Plus 8:ziad016 (2024)
Publ. Version/Full Text DOI PMC
Open Access Gold
Creative Commons Lizenzvertrag
Bone development and remodeling are controlled by the phosphoinositide-3-kinase (Pi3k) signaling pathway. We investigated the effects of downregulation of phosphatase and tensin homolog (Pten), a negative regulator of Pi3k signaling, in a mouse model of Pten deficiency in preosteoblasts. We aimed to identify mechanisms that are involved in the regulation of bone turnover and are linked to bone disorders. Femora, tibiae, and bone marrow stromal cells (BMSCs) isolated from mice with a conditional deletion of Pten (Pten cKO) in Osterix/Sp7-expressing osteoprogenitor cells were compared to Cre-negative controls. Bone phenotyping was performed by μCT measurements, bone histomorphometry, quantification of bone turnover markers CTX and procollagen type 1 N propeptide (P1NP), and three-point bending test. Proliferation of BMSCs was measured by counting nuclei and Ki-67-stained cells. In vitro, osteogenic differentiation capacity was determined by ALP staining, as well as by detecting gene expression of osteogenic markers. BMSCs from Pten cKO mice were functionally different from control BMSCs. Osteogenic markers were increased in BMSCs derived from Pten cKO mice, while Pten protein expression was lower and Akt phosphorylation was increased. We detected a higher trabecular bone volume and an altered cortical bone morphology in Pten cKO bones with a progressive decrease in bone and tissue mineral density. Pten cKO bones displayed fewer osteoclasts and more osteoblasts (P = .00095) per trabecular bone surface and a higher trabecular bone formation rate. Biomechanical analysis revealed a significantly higher bone strength (P = .00012 for males) and elasticity of Pten cKO femora. On the cellular level, both proliferation and osteogenic differentiation capacity of Pten cKO BMSCs were significantly increased compared to controls. Our findings suggest that Pten knockout in osteoprogenitor cells increases bone stability and elasticity by increasing trabecular bone mass and leads to increased proliferation and osteogenic differentiation of BMSCs.
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Publication type Article: Journal article
Document type Scientific Article
Corresponding Author
Keywords Pten ; Bone Marrow ; Osteoprogenitor ; Osterix ; Stem Cells; Mice; Differentiation; Abnormalities; Inactivation; Osterix
ISSN (print) / ISBN 2473-4039
e-ISSN 2473-4039
Journal JBMR Plus
Quellenangaben Volume: 8, Issue: 3, Pages: , Article Number: ziad016 Supplement: ,
Publisher Wiley
Publishing Place Great Clarendon St, Oxford Ox2 6dp, England
Non-patent literature Publications
Reviewing status Peer reviewed
Institute(s) Helmholtz Institute for Metabolism, Obesity and Vascular Research (HI-MAG)
Grants Leipzig University within the program of Open Access Publishing
German Research Foundation (DFG)