scholarly journals Wnt5a/FZD4 Mediates the Mechanical Stretch-Induced Osteogenic Differentiation of Bone Mesenchymal Stem Cells

2018 ◽  
Vol 48 (1) ◽  
pp. 215-226 ◽  
Author(s):  
Qingguo Gu ◽  
Haijun Tian ◽  
Kai Zhang ◽  
Deyu Chen ◽  
Dechun Chen ◽  
...  
Keyword(s):  
Bone Formation ◽  
Osteogenic Differentiation ◽  
Mechanical Loading ◽  
Mechanical Stimulation ◽  
Mechanical Stretch ◽  
Wnt Signalling ◽  
Hindlimb Unloading ◽  
Mechanical Stimuli ◽  
Bone Mesenchymal Stem Cells ◽  
Alizarin Red

Background/Aims: Mechanical stimulation and WNT signalling have essential roles in regulating the osteogenic differentiation of bone marrow stromal cells (BMSCs) and bone formation. However, little is known regarding the regulation of WNT signalling molecule expression and therefore the osteogenic differentiation of BMSCs during osteogenesis. Methods: Microarrays of BMSCs from elderly individuals or patients with osteoporosis (GSE35959) from the GEO database were analysed using GeneSight-Lite 4.1.6 (BioDiscovery) and C2 curated gene sets downloaded from Molecular Signatures Database (MSigDB). Realtime PCR and western blotting were used to measure the expression of the indicated genes. ALP and Alizarin red staining were used to evaluate the osteogenesis of BMSCs. Results: In this study, we investigated whether mechanical loading directly regulates the expression of WNT signalling molecules and examined the role of WNT signalling in mechanical loading-triggered osteogenic differentiation and bone formation. We first studied the microarrays of samples from patients with osteoporosis and found downregulation of the GPCR ligand binding gene set in the BMSCs of patients with osteoporosis. Then, we demonstrated that mechanical stimuli can regulate osteogenesis and bone formation both in vivo and in vitro. FZD4 was upregulated during cyclic mechanical stretch (CMS)-induced osteogenic differentiation, and the JNK signalling pathway was activated. FZD4 knockdown inhibited the mechanical stimuli-induced osteogenesis and JNK activity. More importantly, we found an activating effect of WNT5A and FZD4 that regulated bone formation in response to hindlimb unloading in mice, and pretreatment with WNT5A or activation of the expression of FZD4 partly rescued the osteoporosis caused by mechanical unloading. Conclusions: Our results demonstrate, for the first time, that mechanical stimulation alters the expression of genes involved in the osteogenic differentiation of BMSCs via the direct regulation of FZD4 and that therapeutic WNT5A and FZD saRNA may be an efficient strategy for enhancing bone formation under mechanical stimulation.

scholarly journals Effect of mechanical loading on insulin-like growth factor-I gene expression in rat tibia

2007 ◽  
Vol 192 (1) ◽  
pp. 131-140 ◽  
Author(s):  
Christianne M A Reijnders ◽  
Nathalie Bravenboer ◽  
Annechien M Tromp ◽  
Marinus A Blankenstein ◽  
Paul Lips
Keyword(s):  
Bone Formation ◽  
Mrna Expression ◽  
Mechanical Loading ◽  
Mechanical Stimulation ◽  
Molecular Mechanisms ◽  
Bone Marrow Cells ◽  
Mechanical Stimuli ◽  
Igf I ◽  
Female Wistar Rats ◽  
Tibia Shaft

Mechanical loading plays an essential role in maintaining skeletal integrity. Mechanical stimulation leads to increased bone formation. However, the cellular and molecular mechanisms that are involved in the translation of mechanical stimuli into bone formation, are not completely understood. Growth factors and osteocytes, which act as mechanosensors, play a key role during the bone formation after mechanical stimulation. The aim of this study was to characterize the role of IGF-I in the translation of mechanical stimuli into bone formation locally in rat tibiae. Fifteen female Wistar rats were randomly assigned to three groups (n = 5): load, sham-loaded, and control. The four-point bending model of Forwood and Turner was used to induce a single period of mechanical loading on the tibia shaft. The effects of mechanical loading on IGF-I mRNA expression were determined with non-radioactive in situ hybridization on decalcified tibiae sections, 6 h after the loading session. Endogenous IGF-I mRNA was expressed in trabecular and cortical osteoblasts, some trabecular and sub-endocortical osteocytes, intracortical endothelial cells of blood vessels, and periosteum. Megakaryocytes, macrophages, and myeloid cells also expressed IGF-I mRNA. In the growth plate, IGF-I mRNA was located in proliferative and hypertrophic chondrocytes. Mechanical loading did not affect the IGF-I mRNA expression in osteoblasts, bone marrow cells, and chondrocytes, but the osteocytes at the endosteal side of the shaft showed a twofold increase of IGF-I mRNA expression. The proportion of IGF-I mRNA positive osteocytes in loaded tibiae was 29.3 ± 12.9% (mean ± s.d.; n = 5), whereas sham-loaded and contra-lateral control tibiae exhibited 16.7 ± 4.4% (n = 5) and 14.7 ± 4.2% (n = 10) respectively (P < 0.05). Lamellar bone formation after a single mechanical loading session was observed at the endosteal side of the shaft. In conclusion, a single loading session results in a twofold up-regulation of IGF-I mRNA synthesis in osteocytes which are present in multiple layers extending into the cortical bone of mechanically stimulated tibia shaft 6 h after loading. This supports the hypothesis that IGF-I, which is located in osteocytes, is involved in the translation of mechanical stimuli into bone formation.

miR-138-5p knockdown promotes osteogenic differentiation through FOXC1 up-regulation in human bone mesenchymal stem cells

2020 ◽  
Author(s):  
Lan Zhang ◽  
Yan Liu ◽  
Bo Feng ◽  
Li-Gong Liu ◽  
Ying-Cai Zhou ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Osteogenic Differentiation ◽  
Flow Cytometric Analysis ◽  
Human Bone ◽  
Luciferase Assay ◽  
Induction Medium ◽  
Cell Surface Antigens ◽  
Bone Mesenchymal Stem Cells ◽  
Alizarin Red

This study aimed to certify the hypothesis that miR-138-5p is expected to reduced osteodifferentiation of human bone mesenchymal stem cells (hBMSCs) by FOXC1 down-regulation. hBMSCs were separated from bone marrow and osteogenic induction medium was added to stimulate osteogenic differentiation. Flow cytometric analysis was applied to evaluate the expression of cell surface antigens associated with hBMSCs, including CD29, CD44, CD90, CD45 and CD34. qRT-PCR assay and western blot assay were determined to measure the mRNA and protein expression of miR-138-5p, OCN, RUNX2, BSP, ALP and FOXC1. Alkaline phosphatase (ALP) staining assay and Alizarin Red Staining (ARS) assay were determined to validate the osteogenic differentiation. Luciferase assay was applied to test the interaction of miR-138-5p and FOXC1. We demonstrated miR-138-5p is downregulated in osteogenic differentiated hBMSCs. Besides, miR-138-5p overexpression diminished osteodifferentiated markers expression, ALP activity and ARS activity. Furthermore, we revealed that forkhead transcription factor C1 (FOXC1) was a downstream target gene of miR-138-5p and knockdown of miR-138-5p improved the osteogenesis differentiation of hBMSCs by upregulating FOXC1. miR-138-5p knockdown promoted osteogenic differentiation in hBMSCs via directly targeting FOXC1. This study suggested miR-138-5p may be a new target for hBMSCs osteogenic differentiation and the treatment of bone defects.

scholarly journals Silencing of Long Non-Coding RNA NONHSAT009968 Ameliorates the Staphylococcal Protein A-Inhibited Osteogenic Differentiation in Human Bone Mesenchymal Stem Cells

2016 ◽  
Vol 39 (4) ◽  
pp. 1347-1359 ◽  
Author(s):  
Yi Cui ◽  
Sheng Lu ◽  
Hongbo Tan ◽  
Jun Li ◽  
Min Zhu ◽  
...  
Keyword(s):  
Stem Cells ◽  
Osteogenic Differentiation ◽  
Protein A ◽  
Staphylococcal Protein A ◽  
Activity Detection ◽  
Bone Mesenchymal Stem Cells ◽  
Alizarin Red ◽  
Inflammatory Microenvironment ◽  
Alp Activity ◽  
Spa Treatment

Background/Aims: Osteomyelitis is defined as an inflammation of the bones and bone marrow. The inflammatory microenvironment attenuates the osteogenic differentiation capacity of stem cells and inhibits osteoblast-mediated bone formation, leading to net bone loss. However, the whole expression profile, function and side effect of long non-coding RNAs (lncRNAs) on osteogenic differentiation of stem cells in an inflammatory microenvironment of osteomyelitis are not known. Methods: In the present study, human bone mesenchymal stem cells (hBMSCs) were treated with different concentrations of Staphylococcal protein A (SpA) to trigger an inflammatory microenvironment in vitro to partly duplicate the inflammatory microenvironment of osteomyelitis, which was confirmed using ELISA for detecting the inflammatory cytokines. The complete expression profiles of lncRNAs and mRNA during osteogenic differentiation of hBMSCs in an inflammatory microenvironment triggered by SpA were analyzed using a lncRNA microarray. LncRNA expression levels were verified by quantitative reverse transcription PCR analysis (qRT-PCR). The expression of NONHSAT009968 in hB-MSCs was silenced by infection with lentivirus expressing NONHSAT009968-shRNA. The expression of Runx2, OCN, OPN, COL1A1, and alkaline phosphatase (ALP) activity was detected by western blot. Alizarin red staining and ALP activity detection were carried out. Results: The results of ELISA showed that SpA treatment induced secretion of inflammatory cytokines IL-1A, IL-6, and TNFA. The results of alizarin red staining and ALP detection showed that SpA treatment suppressed the osteogenic differentiation of hBMSCs. A total of 2033 lncRNAs were found with aberrant expression in SpA-treated hBMSCs compared to controls. Among these lncRNAs, 641 were down-regulated and 1392 were up-regulated. Based on the results of qRT-PCR, lncRNA NONHSAT009968 was chosen for further investigation. The results of alizarin red staining, ALP activity detection, and western blot detection of Runx2, OCN, OPN, COL1A1, and ALP indicated that NONHSAT009968 silencing ameliorates SpA-inhibited osteogenic differentiation in hBMSCs. Conclusion: Our present study provides a basis for future analyses of the role of lncRNAs in osteoblastic differentiation in an inflammatory environment triggered by SpA, and lncRNA NONHSAT009968 might be a new target for promoting osteoblast formation.

scholarly journals lncRNA MALAT1 Mediates Osteogenic Differentiation and Apoptosis in Osteoporosis by Regulating the miR-485-5p/WNT7B Axis

2021 ◽  
Author(s):  
Yuan Zhou ◽  
Zhuo Xu ◽  
Yuanyi Wang ◽  
Qiang Song ◽  
Ruofeng Yin
Keyword(s):  
Osteogenic Differentiation ◽  
Cell Apoptosis ◽  
Binding Sites ◽  
Hindlimb Unloading ◽  
Cellular Functions ◽  
Alizarin Red ◽  
Lncrna Malat1 ◽  
Non Coding Rnas

Abstract Background: Accumulating evidence demonstrates that long non-coding RNAs (lncRNAs) are associated with the development of osteoporosis. This study aimed to investigate the effects of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) on osteogenic differentiation and cell apoptosis in osteoporosis. Methods: hindlimb unloading (HU) was performed to establish osteoporosis model in vivo. MicroCT was applied for pathological analysis. Microgravity (MG) was used to construct osteoporosis in vitro. The mRNA and miRNA expression was determined using RT-qPCR. Protein expression was determined using western blot. The binding sites between miR-485-5p and MALAT1/Wnt family member 7B (WNT7B) was predicted by bioinformatics analysis and verified by luciferase and RNA pull-down assays. Cellular functions were determined by ALP staining, Alizarin red staining, and flow cytometry assays. Results: MALAT1 expression was downregulated in HU mice and MG treated MC3T3-E1 cells. However, overexpression of MALAT1 upregulated the expression of Bmp4, Col1a1, Spp1, and enhanced ALP activity. Additionally, overexpression of MALAT1 inhibited apoptosis, decreased Bax and caspase-3 levels, and increased Bcl-2 level. Moreover, MALAT1 overexpression improved bone phenotype in vivo. MALAT1 functioned as a ceRNA to upregulate WNT7B. Overexpression of miR-485-5p rescued the promotion of osteogenic differentiation and the inhibition of apoptosis induced by MALAT1. Knockdown of WNT7B abolished the facilitation of osteogenic differentiation and the suppression of apoptosis induced by downregulation of miR-485-5p. Conclusion: In conclusion, MALAT1 promoted osteogenic differentiation and inhibited cell apoptosis through miR-485-5p/WNT7B axis, which suggested that MALAT1 is a potential target to alleviate osteoporosis.

scholarly journals MiR-26b-5p Promotes Osteogenesis of Bone Mesenchymal Stem Cells via Suppressing FGF21

2021 ◽  
Author(s):  
Bin Wang ◽  
Zhenhui Li ◽  
Caiyuan Mai ◽  
Penglin Mou ◽  
Lei Pan
Keyword(s):  
Osteogenic Differentiation ◽  
Luciferase Reporter ◽  
Control Group ◽  
Osteogenic Differentiation Medium ◽  
Bone Mesenchymal Stem Cells ◽  
Alizarin Red ◽  
Osteogenic Induction ◽  
Direct Target ◽  
Inhibition Group ◽  
Fgf21 Expression

Abstract Introduction: It has been established that miR-26b-5p actively participate in the osteogenic differentiation of bone mesenchymal stem cells (BMSCs), which is of great value in osteoporosis treatment. Database showed that Fibroblast growth factor(FGF)21 is a potential binding site of miR-26b-5p. This study aimed to investigate the molecular osteogenic mechanisms of miR-26b-5p targeting FGF21 in postmenopausal osteoporosis (PMOP). Methods: 5ml of bone marrow was aspirated from the anterior superior iliac spine in 10 PMOP women during bone marrow puncture. BMSCs were used to establish an in vitro cell model, and BMSCs markers were analyzed by flow cytometry. miR-26b-5p and FGF21 were overexpressed for 48h, and then placed in an osteogenic induction medium for osteogenic induction culture, the expression of RNA was detect using RT-qPCR. Cells from miR-26b-5p group were collected on days 7, 14 and 21 of induction for ALP and alizarin red S staining. On day 7 of induction, RT-qPCR was used to measure Runx2, Osterix (Osx), and target gene FGF21 expression levels in each group. The dual-luciferase reporter gene system was used to verify that FGF21 was a direct target of miR-26b-5p. FGF21 was measured by western blotting in the miR-26b-5p overexpression group and in the miR-26b-5p inhibition group. Results: BMSCs were identified according with the antigenic characteristics. miR-26b-5p expression was significantly upregulated after the expression of miR-26b-5p mimics; however, FGF21 expression was downregulated after FGF21 mimics. After overexpression of miR-26b-5p, the alkaline phosphatase activity and nodules of alizarin red S in the culture medium gradually increased as the induction time increased. RT-qPCR showed that the expressions of master osteogenic factors Runx2 and Osx in the BMSC+ osteogenic differentiation medium group was significantly higher than in the BMSC group, the expressions of the factors in the BMSC+ miR-26b-5p overexpression group was significantly higher than in the control group. Target gene FGF21 expression was significantly lower in the BMSC+ osteogenic differentiation medium group than in the BMSC group, and was significantly lower in the BMSC+ miR-26b-5p overexpression group than in the control group. Luciferase reporter assays demonstrated that FGF21 was a direct target of miR-26b-5p. Finally, western blotting analysis showed that FGF21 expression was significantly downregulated in the miR-26b-5p overexpressed group and upregulated in the miR-26b-5p inhibition group. Conclusion: miR-26b-5p can regulate the osteogenic differentiation of BMSCs and participate in PMOP pathogenesis via suppressing FGF21. The present study provides the basis for further studies on PMOP.

scholarly journals ER stress arm XBP1s plays a pivotal role in proteasome inhibition-induced bone formation

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Dan Zhang ◽  
Kim De Veirman ◽  
Rong Fan ◽  
Qiang Jian ◽  
Yuchen Zhang ◽  
...  
Keyword(s):  
Bone Formation ◽  
Er Stress ◽  
Osteogenic Differentiation ◽  
Osteoblast Differentiation ◽  
Bone Destruction ◽  
Proteasome Inhibition ◽  
Stress Signaling ◽  
Alizarin Red

Abstract Background Bone destruction is a hallmark of multiple myeloma (MM). It has been reported that proteasome inhibitors (PIs) can reduce bone resorption and increase bone formation in MM patients, but the underlying mechanisms remain unclear. Methods Mesenchymal stem cells (MSCs) were treated with various doses of PIs, and the effects of bortezomib or carfilzomib on endoplasmic reticulum (ER) stress signaling pathways were analyzed by western blotting and real-time PCR. Alizarin red S (ARS) and alkaline phosphatase (ALP) staining were used to determine the osteogenic differentiation in vitro. Specific inhibitors targeting different ER stress signaling and a Tet-on inducible overexpressing system were used to validate the roles of key ER stress components in regulating osteogenic differentiation of MSCs. Chromatin immunoprecipitation (ChIP) assay was used to evaluate transcription factor-promoter interaction. MicroCT was applied to measure the microarchitecture of bone in model mice in vivo. Results We found that both PERK-ATF4 and IRE1α-XBP1s ER stress branches are activated during PI-induced osteogenic differentiation. Inhibition of ATF4 or XBP1s signaling can significantly impair PI-induced osteogenic differentiation. Furthermore, we demonstrated that XBP1s can transcriptionally upregulate ATF4 expression and overexpressing XBP1s can induce the expression of ATF4 and other osteogenic differentiation-related genes and therefore drive osteoblast differentiation. MicroCT analysis further demonstrated that inhibition of XBP1s can strikingly abolish bortezomib-induced bone formation in mouse. Conclusions These results demonstrated that XBP1s is a master regulator of PI-induced osteoblast differentiation. Activation of IRE1α-XBP1s ER stress signaling can promote osteogenesis, thus providing a novel strategy for the treatment of myeloma bone disease.

Osteocytes and WNT: the Mechanical Control of Bone Formation

2010 ◽  
Vol 89 (4) ◽  
pp. 331-343 ◽  
Author(s):  
C. Galli ◽  
G. Passeri ◽  
G.M. Macaluso
Keyword(s):  
Mechanical Properties ◽  
Bone Formation ◽  
Cell Fate ◽  
Mechanical Loading ◽  
Osteoblastic Differentiation ◽  
Mechanical Stimuli ◽  
Master Regulators ◽  
Bone Maintenance ◽  
Skeletal Homeostasis ◽  
Encoding Gene

Mechanical loading is of pivotal importance in the maintenance of skeletal homeostasis, but the players involved in the transduction of mechanical stimuli to promote bone maintenance have long remained elusive. Osteocytes, the most abundant cells in bone, possess mechanosensing appendices stretching through a system of bone canaliculi. Mechanical stimulation plays an important role in osteocyte survival and hence in the preservation of bone mechanical properties, through the maintenance of bone hydratation. Osteocytes can also control the osteoblastic differentiation of mesenchymal precursors in response to mechanical loading by modulating WNT signaling pathways, essential regulators of cell fate and commitment, through the protein sclerostin. Mutations of Sost, the sclerostin-encoding gene, have dramatic effects on the skeleton, indicating that osteocytes may act as master regulators of bone formation and localized bone remodeling. Moreover, the development of sclerostin inhibitors is opening new possibilities for bone regeneration in orthopedics and the dental field.

scholarly journals Osteogenic differentiation of rat bone mesenchymal stem cells cultured on poly (hydroxybutyrate-co-hydroxyvalerate), poly (ε-caprolactone) scaffolds

2021 ◽  
Vol 32 (11) ◽  
Author(s):  
Ana A. Rodrigues ◽  
Nilza A. Batista ◽  
Sônia M. Malmonge ◽  
Suzan A. Casarin ◽  
José Augusto M. Agnelli ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Osteogenic Differentiation ◽  
Mtt Assay ◽  
Vero Cells ◽  
Sem Analysis ◽  
Bone Mesenchymal Stem Cells ◽  
Alizarin Red ◽  
Cytochemical Study ◽  
Alp Activity

AbstractBioresorbable biomaterials can fill bone defects and act as temporary scaffold to recruit MSCs to stimulate their differentiation. Among the different bioresorbable polymers studied, this work focuses on poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and poly(ε-caprolactone) (PCL). Were prepared blends of PHBV and PCL to obtain PHBV based biomaterials with good tenacity, important for bone tissue repair, associated with biocompatible properties of PCL. This study assesses the viability of Vero cells on scaffolds of PHBV, PCL, and their blends and the osteogenic differentiation of mesenchymal stem cells (MSCs). Materials were characterized in surface morphology, DSC and Impact Strength (IS). Vero cells and MSCs were assessed by MTT assay, cytochemical and SEM analysis. MSC osteogenic differentiation was evaluated through alizarin red staining and ALP activity. We found some roughness onto surface materials. DSC showed that the blends presented two distinct melting peaks, characteristic of immiscible blends. IS test confirmed that PHBV-PCL blends is an alternative for increase the tenacity of PHBV. MTT assay showed cells with high metabolic activities on extract toxicity test, but with low activity in the direct contact test. SEM analysis showed spreading cells with irregular and flattened morphology on different substrates. Cytochemical study revealed that MSCs maintained their morphology, although in smaller number for MSCs. The development of nodules of mineralized organic matrix in MSC cultures was identified by alizarin red staining and osteogenic differentiation was confirmed by the quantification of ALP activity. Thus, our scaffolds did not interfere on viability of Vero cells or the osteogenic differentiation of MSCs.

scholarly journals Mechanical Loading Shows Anti-Myeloma Effects While Rescuing Bone Loss with Net Bone Formation in a Myeloma Bone Disease Murine Model

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 3164-3164
Author(s):  
Fani Ziouti ◽  
Maximilian Rummler ◽  
Andreas Brandl ◽  
Andreas Beilhack ◽  
Maureen Lynch ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Bone Loss ◽  
Bone Formation ◽  
Bone Remodeling ◽  
Mechanical Loading ◽  
Bone Disease ◽  
Whole Body ◽  
Enzyme Linked Immunosorbent Assay ◽  
Mechanical Stimuli

Abstract Osteolytic bone disease (BD) is a hallmark of multiple myeloma (MM) with tumor cells in the bone marrow shifting the balance of the bone remodeling process towards massive bone resorption. As a result, patients develop devastating osteolytic lesions that lead to non-healing bone fractures and pain, affecting life quality and mortality rates. Bones have the capacity to adapt mass and structure to mechanical stimuli, as dramatically seen in young tennis athletes with muscle-bone asymmetries in the playing arm. We have previously shown that tibial mechanical loading rescued bone loss in our murine MOPC315.BM MM model with an advanced osteolytic phenotype. Here, we hypothesize that mechanical strain (1) modulates the bone microenvironment and (2) has antitumor activity in mice. (1) We determined bone formation and bone resorption parameters by time-lapsed microCT analysis to show how skeletal mechanical stimuli control MM bone disease (MMBD) progression over time. (2) To monitor tumor progression, we used non-invasive bioluminescence imaging (BLI) and enzyme-linked immunosorbent assay (ELISA) for detection of MOPC315.BM specific immunoglobulin A (IgA) levels. In our in vivo loading study, we injected MOPC315.BM cells intratibially (i.t.) in BALB/c mice to establish MMBD (n=17) and used PBS-injected (n=13) as well as noninjected mice (n=8) as controls. Eight (MM), seven (PBS) and 8 (noninjected) mice received compressive tibial loading for three weeks while nine (MM) and six (PBS) mice served as nonloaded controls. The bone remodeling response to mechanical loading was investigated by longitudinal in vivo microCT imaging performed every 5 days (at day 13, 18, 23, 28, and 33 after i.t. injection). MicroCT images from day 33 were geometrically registered onto images of day 13 and resampled into the same coordinate system using Amira and scripts written in Matlab for post-processing. Normalized newly mineralized and eroded bone volume (MV/BV, EV/BV), normalized formed and eroded bone surface area (MS/BS, ES/BS), mineralized thickness (MTh) and eroded depth (ED) were quantified. ANOVA was performed to examine the effect of loading and injection. Loading significantly increased the periosteal MV/BV, periosteal and endosteal MS/BS as well as decreased the periosteal EV/BV and periosteal and endocortical ES/BS. Endosteal MV/BV or EV/BV were not affected, which may be due to differences in the local strain environment at the two surfaces. In addition, mechanical stimuli did not influence ED, but led to diminished periosteal EV/BV and periosteal ES/BS suggesting fewer resorption sites in tibiae subjected to loading. Injection significantly affected periosteal and endosteal bone formation and resorption (Fig.1). Significant increases in cortical bone mass of loaded MM mice were accompanied by decreases in tumor load as evidenced by MOPC315.BM specific IgA levels (Fig. 2A). Interestingly, quantification of tibial and whole body bioluminescence signal intensities revealed controlled tumor growth in the loaded left tibia and a further delay of tumor cell dissemination throughout body of MM mice (Fig. 2B). Our data provide evidence that skeletal mechanical stimuli have anti-myeloma effects and rescue osteolytic bone loss in MMBD. The anabolic response to mechanical loads outweighs the anti-resorptive effect of MM cells, suggesting a combination of loading with bone resorption inhibitors in future therapeutic strategies. Disclosures No relevant conflicts of interest to declare.

Sign in / Sign up

Export Citation Format

Share Document