J. Lorenz, Sandy Richter, Anna S. Kirstein, Florentien Kolbig, Michèle Nebe, Marco Schulze, Wieland Kiess, Ingo Spitzbarth, Nora Klöting, D. Le Duc, Ulrike Baschant, A. Garten
{"title":"小鼠前成骨细胞中的 Pten 基因敲除导致骨转换和骨强度发生变化","authors":"J. Lorenz, Sandy Richter, Anna S. Kirstein, Florentien Kolbig, Michèle Nebe, Marco Schulze, Wieland Kiess, Ingo Spitzbarth, Nora Klöting, D. Le Duc, Ulrike Baschant, A. Garten","doi":"10.1093/jbmrpl/ziad016","DOIUrl":null,"url":null,"abstract":"\n 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.\n 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 P1NP and 3-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.\n 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 = 0.00095) per trabecular bone surface and a higher trabecular bone formation rate. Biomechanical analysis revealed a significantly higher bone strength (p = 0.00012 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.\n 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 bone marrow stromal cells.","PeriodicalId":14611,"journal":{"name":"JBMR Plus","volume":null,"pages":null},"PeriodicalIF":3.4000,"publicationDate":"2024-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Pten knockout in mouse preosteoblasts leads to changes in bone turnover and strength\",\"authors\":\"J. Lorenz, Sandy Richter, Anna S. Kirstein, Florentien Kolbig, Michèle Nebe, Marco Schulze, Wieland Kiess, Ingo Spitzbarth, Nora Klöting, D. Le Duc, Ulrike Baschant, A. Garten\",\"doi\":\"10.1093/jbmrpl/ziad016\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"\\n 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.\\n 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 P1NP and 3-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.\\n 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 = 0.00095) per trabecular bone surface and a higher trabecular bone formation rate. Biomechanical analysis revealed a significantly higher bone strength (p = 0.00012 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.\\n 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 bone marrow stromal cells.\",\"PeriodicalId\":14611,\"journal\":{\"name\":\"JBMR Plus\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":3.4000,\"publicationDate\":\"2024-01-04\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"JBMR Plus\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1093/jbmrpl/ziad016\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"ENDOCRINOLOGY & METABOLISM\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"JBMR Plus","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1093/jbmrpl/ziad016","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENDOCRINOLOGY & METABOLISM","Score":null,"Total":0}
Pten knockout in mouse preosteoblasts leads to changes in bone turnover and strength
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 P1NP and 3-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 = 0.00095) per trabecular bone surface and a higher trabecular bone formation rate. Biomechanical analysis revealed a significantly higher bone strength (p = 0.00012 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 bone marrow stromal cells.