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McClendon MT, Ji W, Greene AC, Sai H, Sangji MH, Sather NA, Chen CH, Lee SS, Katchko K, Jeong SS, Kannan A, Weiner J, Cook R, Driscoll A, Lubbe R, Chang K, Haleem M, Chen F, Qiu R, Chun D, Stock SR, Hsu WK, Hsu EL, Stupp SI. A supramolecular polymer-collagen microparticle slurry for bone regeneration with minimal growth factor. Biomaterials 2023; 302:122357. [PMID: 37879188 PMCID: PMC10897953 DOI: 10.1016/j.biomaterials.2023.122357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 10/05/2023] [Accepted: 10/15/2023] [Indexed: 10/27/2023]
Abstract
Recombinant bone morphogenetic protein-2 (BMP-2) is a potent osteoinductive growth factor that can promote bone regeneration for challenging skeletal repair and even for ectopic bone formation in spinal fusion procedures. However, serious clinical side effects related to supraphysiological dosing highlight the need for advances in novel biomaterials that can significantly reduce the amount of this biologic. Novel biomaterials could not only reduce clinical side effects but also expand the indications for use of BMP-2, while at the same time lowering the cost of such procedures. To achieve this objective, we have developed a slurry containing a known supramolecular polymer that potentiates BMP-2 signaling and porous collagen microparticles. This slurry exhibits a paste-like consistency that stiffens into an elastic gel upon implantation making it ideal for minimally invasive procedures. We carried out in vivo evaluation of the novel biomaterial in the rabbit posterolateral spine fusion model, and discovered efficacy at unprecedented ultra-low BMP-2 doses (5 μg/implant). This dose reduces the growth factor requirement by more than 100-fold relative to current clinical products. This observation is significant given that spinal fusion involves ectopic bone formation and the rabbit model is known to be predictive of human efficacy. We expect the novel biomaterial can expand BMP-2 indications for difficult cases requiring large volumes of bone formation or involving patients with underlying conditions that compromise bone regeneration.
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Affiliation(s)
- Mark T McClendon
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL, 60611, United States
| | - Wei Ji
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL, 60611, United States
| | - Allison C Greene
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL, 60611, United States; Department of Orthopaedic Surgery, Northwestern University, Chicago, IL, 60611, United States
| | - Hiroaki Sai
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL, 60611, United States
| | - M Hussain Sangji
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL, 60611, United States; Department of Biomedical Engineering, Northwestern University, Evanston, IL, 60208, United States
| | - Nicholas A Sather
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL, 60611, United States
| | - Charlotte H Chen
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL, 60611, United States
| | - Sungsoo S Lee
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL, 60611, United States
| | - Karina Katchko
- Department of Orthopaedic Surgery, Northwestern University, Chicago, IL, 60611, United States
| | - Soyeon Sophia Jeong
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL, 60611, United States; Department of Orthopaedic Surgery, Northwestern University, Chicago, IL, 60611, United States
| | - Abhishek Kannan
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL, 60611, United States; Department of Orthopaedic Surgery, Northwestern University, Chicago, IL, 60611, United States
| | - Joseph Weiner
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL, 60611, United States; Department of Orthopaedic Surgery, Northwestern University, Chicago, IL, 60611, United States
| | - Ralph Cook
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL, 60611, United States; Department of Orthopaedic Surgery, Northwestern University, Chicago, IL, 60611, United States
| | - Adam Driscoll
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL, 60611, United States; Department of Orthopaedic Surgery, Northwestern University, Chicago, IL, 60611, United States
| | - Ryan Lubbe
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL, 60611, United States; Department of Orthopaedic Surgery, Northwestern University, Chicago, IL, 60611, United States
| | - Kevin Chang
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL, 60611, United States; Department of Orthopaedic Surgery, Northwestern University, Chicago, IL, 60611, United States
| | - Meraaj Haleem
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL, 60611, United States; Department of Orthopaedic Surgery, Northwestern University, Chicago, IL, 60611, United States
| | - Feng Chen
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL, 60611, United States
| | - Ruomeng Qiu
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL, 60611, United States; Department of Chemistry, Northwestern University, Evanston, IL, 60208, United States
| | - Danielle Chun
- Department of Orthopaedic Surgery, Northwestern University, Chicago, IL, 60611, United States
| | - Stuart R Stock
- Department of Cell and Molecular Biology, Northwestern University, Chicago, IL, 60611, United States
| | - Wellington K Hsu
- Department of Orthopaedic Surgery, Northwestern University, Chicago, IL, 60611, United States
| | - Erin L Hsu
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL, 60611, United States; Department of Orthopaedic Surgery, Northwestern University, Chicago, IL, 60611, United States
| | - Samuel I Stupp
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL, 60611, United States; Department of Biomedical Engineering, Northwestern University, Evanston, IL, 60208, United States; Department of Chemistry, Northwestern University, Evanston, IL, 60208, United States; Department of Materials Science and Engineering, Northwestern University, Evanston, IL, 60208, United States; Department of Medicine, Northwestern University, Chicago, IL, 60611, United States.
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Sangadala S, Kim CH, Fernandes LM, Makkar P, Beck GR, Boden SD, Drissi H, Presciutti SM. Sclerostin small-molecule inhibitors promote osteogenesis by activating canonical Wnt and BMP pathways. eLife 2023; 12:e63402. [PMID: 37560905 PMCID: PMC10431921 DOI: 10.7554/elife.63402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 08/09/2023] [Indexed: 08/11/2023] Open
Abstract
Background The clinical healing environment after a posterior spinal arthrodesis surgery is one of the most clinically challenging bone-healing environments across all orthopedic interventions due to the absence of a contained space and the need to form de novo bone. Our group has previously reported that sclerostin in expressed locally at high levels throughout a developing spinal fusion. However, the role of sclerostin in controlling bone fusion remains to be established. Methods We computationally identified two FDA-approved drugs, as well as a single novel small-molecule drug, for their ability to disrupt the interaction between sclerostin and its receptor, LRP5/6. The drugs were tested in several in vitro biochemical assays using murine MC3T3 and MSCs, assessing their ability to (1) enhance canonical Wnt signaling, (2) promote the accumulation of the active (non-phosphorylated) form of β-catenin, and (3) enhance the intensity and signaling duration of BMP signaling. These drugs were then tested subcutaneously in rats as standalone osteoinductive agents on plain collagen sponges. Finally, the top drug candidates (called VA1 and C07) were tested in a rabbit posterolateral spine fusion model for their ability to achieve a successful fusion at 6 wk. Results We show that by controlling GSK3b phosphorylation our three small-molecule inhibitors (SMIs) simultaneously enhance canonical Wnt signaling and potentiate canonical BMP signaling intensity and duration. We also demonstrate that the SMIs produce dose-dependent ectopic mineralization in vivo in rats as well as significantly increase posterolateral spine fusion rates in rabbits in vivo, both as standalone osteogenic drugs and in combination with autologous iliac crest bone graft. Conclusions Few if any osteogenic small molecules possess the osteoinductive potency of BMP itself - that is, the ability to form de novo ectopic bone as a standalone agent. Herein, we describe two such SMIs that have this unique ability and were shown to induce de novo bone in a stringent in vivo environment. These SMIs may have the potential to be used in novel, cost-effective bone graft substitutes for either achieving spinal fusion or in the healing of critical-sized fracture defects. Funding This work was supported by a Veteran Affairs Career Development Award (IK2-BX003845).
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Affiliation(s)
- Sreedhara Sangadala
- Atlanta Veterans Affairs Medical CenterDecaturUnited States
- Department of Orthopaedics, Emory University School of MedicineAtlantaUnited States
| | - Chi Heon Kim
- Department of Orthopaedics, Emory University School of MedicineAtlantaUnited States
| | - Lorenzo M Fernandes
- Atlanta Veterans Affairs Medical CenterDecaturUnited States
- Department of Orthopaedics, Emory University School of MedicineAtlantaUnited States
| | - Pooja Makkar
- Department of Biotechnology, Panjab UniversityChandigarhIndia
| | - George R Beck
- Atlanta Veterans Affairs Medical CenterDecaturUnited States
- Emory University, Division of EndocrinologyAtlantaUnited States
| | - Scott D Boden
- Department of Orthopaedics, Emory University School of MedicineAtlantaUnited States
| | - Hicham Drissi
- Atlanta Veterans Affairs Medical CenterDecaturUnited States
- Department of Orthopaedics, Emory University School of MedicineAtlantaUnited States
| | - Steven M Presciutti
- Atlanta Veterans Affairs Medical CenterDecaturUnited States
- Department of Orthopaedics, Emory University School of MedicineAtlantaUnited States
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Xu K, Chu Y, Liu Q, Fan W, He H, Huang F. NEDD4 E3 Ligases: Functions and Mechanisms in Bone and Tooth. Int J Mol Sci 2022; 23:ijms23179937. [PMID: 36077334 PMCID: PMC9455957 DOI: 10.3390/ijms23179937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 08/26/2022] [Accepted: 08/29/2022] [Indexed: 11/29/2022] Open
Abstract
Protein ubiquitination is a precisely controlled enzymatic cascade reaction belonging to the post-translational modification of proteins. In this process, E3 ligases catalyze the binding of ubiquitin (Ub) to protein substrates and define specificity. The neuronally expressed developmentally down-regulated 4 (NEDD4) subfamily, belonging to the homology to E6APC terminus (HECT) class of E3 ligases, has recently emerged as an essential determinant of multiple cellular processes in different tissues, including bone and tooth. Here, we place special emphasis on the regulatory role of the NEDD4 subfamily in the molecular and cell biology of osteogenesis. We elucidate in detail the specific roles, downstream substrates, and upstream regulatory mechanisms of the NEDD4 subfamily. Further, we provide an overview of the involvement of E3 ligases and deubiquitinases in the development, repair, and regeneration of another mineralized tissue—tooth.
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Affiliation(s)
- Ke Xu
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou 510008, China
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou 510008, China
| | - Yanhao Chu
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou 510008, China
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou 510008, China
| | - Qin Liu
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou 510008, China
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou 510008, China
| | - Wenguo Fan
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou 510008, China
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou 510008, China
| | - Hongwen He
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou 510008, China
- Correspondence: (H.H.); (F.H.)
| | - Fang Huang
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou 510008, China
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou 510008, China
- Correspondence: (H.H.); (F.H.)
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Discovery of a novel class of benzimidazoles as highly effective agonists of bone morphogenetic protein (BMP) receptor signaling. Sci Rep 2022; 12:12146. [PMID: 35840622 PMCID: PMC9287337 DOI: 10.1038/s41598-022-16394-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 07/08/2022] [Indexed: 11/09/2022] Open
Abstract
Increasing or restoring Bone Morphogenetic Protein receptor signaling is an effective therapy for conditions such as bone fracture and pulmonary arterial hypertension. However, direct use of recombinant BMPs has encountered significant obstacles. Moreover, synthetic, full agonists of BMP receptor signaling have yet to be identified. Here, we report the discovery of a novel class of indolyl-benzimidazoles, synthesized using a one-pot synthetic methodology, which appear to mimic the biochemical and functional activity of BMPs. The first-in-series compounds, SY-LB-35 and SY-LB-57, stimulated significant increases in cell number and cell viability in the C2C12 myoblast cell line. Cell cycle analysis revealed that these compounds induced a shift toward proliferative phases. SY-LB-35 and SY-LB-57 stimulated canonical Smad and non-canonical PI3K/Akt, ERK, p38 and JNK intracellular signaling pathways, similar to BMP2-stimulated responses. Importantly, increases in Smad phosphorylation and cell viability were dependent on type I BMP receptor activity. Thus, these compounds robustly activate intracellular signaling in a BMP receptor-dependent manner and may signify the first known, full agonists of BMP receptor signaling. Moreover, discovery of small molecule activators of BMP pathways, which can be efficiently formulated and targeted to diseased or damaged areas, could potentially substitute recombinant BMPs for treatment of BMP-related pathologies.
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Larraufie MH, Gao X, Xia X, Devine PJ, Kallen J, Liu D, Michaud G, Harsch A, Savage N, Ding J, Tan K, Mihalic M, Roggo S, Canham SM, Bushell SM, Krastel P, Gao J, Izaac A, Altinoglu E, Lustenberger P, Salcius M, Harbinski F, Williams ET, Zeng L, Loureiro J, Cong F, Fryer CJ, Klickstein L, Tallarico JA, Jain RK, Rothman DM, Wang S. Phenotypic screen identifies calcineurin-sparing FK506 analogs as BMP potentiators for treatment of acute kidney injury. Cell Chem Biol 2021; 28:1271-1282.e12. [PMID: 33894161 DOI: 10.1016/j.chembiol.2021.04.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 01/29/2021] [Accepted: 04/05/2021] [Indexed: 12/12/2022]
Abstract
Acute kidney injury (AKI) is a life-threatening disease with no known curative or preventive therapies. Data from multiple animal models and human studies have linked dysregulation of bone morphogenetic protein (BMP) signaling to AKI. Small molecules that potentiate endogenous BMP signaling should have a beneficial effect in AKI. We performed a high-throughput phenotypic screen and identified a series of FK506 analogs that act as potent BMP potentiators by sequestering FKBP12 from BMP type I receptors. We further showed that calcineurin inhibition was not required for this activity. We identified a calcineurin-sparing FK506 analog oxtFK through late-stage functionalization and structure-guided design. OxtFK demonstrated an improved safety profile in vivo relative to FK506. OxtFK stimulated BMP signaling in vitro and in vivo and protected the kidneys in an AKI mouse model, making it a promising candidate for future development as a first-in-class therapeutic for diseases with dysregulated BMP signaling.
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Affiliation(s)
| | - Xiaolin Gao
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Xiaobo Xia
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | | | - Joerg Kallen
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Dong Liu
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Gregory Michaud
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Andreas Harsch
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Nik Savage
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Jian Ding
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Kian Tan
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Manuel Mihalic
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Silvio Roggo
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | | | - Simon M Bushell
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Philipp Krastel
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Jinhai Gao
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Aude Izaac
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Erhan Altinoglu
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | | | - Michael Salcius
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Fred Harbinski
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Eric T Williams
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Liling Zeng
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Joseph Loureiro
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Feng Cong
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | - Christy J Fryer
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | | | | | - Rishi K Jain
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA
| | | | - Shaowen Wang
- Novartis Institutes for Biomedical Research, Cambridge, MA, USA.
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Shu DY, Ng K, Wishart TFL, Chui J, Lundmark M, Flokis M, Lovicu FJ. Contrasting roles for BMP-4 and ventromorphins (BMP agonists) in TGFβ-induced lens EMT. Exp Eye Res 2021; 206:108546. [PMID: 33773977 DOI: 10.1016/j.exer.2021.108546] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 03/02/2021] [Accepted: 03/16/2021] [Indexed: 12/28/2022]
Abstract
Transforming growth factor beta (TGFβ) and bone morphogenetic protein (BMP) signaling play opposing roles in epithelial-mesenchymal transition (EMT) of lens epithelial cells, a cellular process integral to the pathogenesis of fibrotic cataract. We previously showed that BMP-7-induced Smad1/5 signaling blocks TGFβ-induced Smad2/3-signaling and EMT in rat lens epithelial cell explants. To further explore the antagonistic role of BMPs on TGFβ-signaling, we tested the capability of BMP-4 or newly described BMP agonists, ventromorphins, in blocking TGFβ-induced lens EMT. Primary rat lens epithelial explants were treated with exogenous TGFβ2 alone, or in combination with BMP-4 or ventromorphins. Treatment with TGFβ2 induced lens epithelial cells to undergo EMT and transdifferentiate into myofibroblastic cells with upregulated α-SMA and nuclear translocation of Smad2/3 immunofluorescence. BMP-4 was able to suppress this EMT without blocking TGFβ2-nuclear translocation of Smad2/3. In contrast, the BMP agonists, ventromorphins, were unable to block TGFβ2-induced EMT, despite a transient and early ability to significantly reduce TGFβ2-induced nuclear translocation of Smad2/3. This intriguing disparity highlights new complexities in the responsiveness of the lens to differing BMP-related signaling. Further research is required to better understand the antagonistic relationship between TGFβ and BMPs in lens EMT leading to cataract.
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Affiliation(s)
- Daisy Y Shu
- School of Medical Sciences, The University of Sydney, NSW, Australia; Save Sight Institute, The University of Sydney, NSW, Australia
| | - Kevin Ng
- School of Medical Sciences, The University of Sydney, NSW, Australia
| | | | - Juanita Chui
- School of Medical Sciences, The University of Sydney, NSW, Australia
| | - Malin Lundmark
- School of Medical Sciences, The University of Sydney, NSW, Australia
| | - Mary Flokis
- School of Medical Sciences, The University of Sydney, NSW, Australia
| | - Frank J Lovicu
- School of Medical Sciences, The University of Sydney, NSW, Australia; Save Sight Institute, The University of Sydney, NSW, Australia.
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Ryan DA, Cheng J, Masuda K, Cashman JR. Role of Curcuminoids and Tricalcium Phosphate Ceramic in Rat Spinal Fusion. Tissue Eng Part C Methods 2020; 26:577-589. [PMID: 33086948 DOI: 10.1089/ten.tec.2020.0217] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Despite considerable research effort, there is a significant need for safe agents that stimulate bone formation. Treatment of large or complex bone defects remains a challenge. Implantation of small molecule-induced human bone marrow-derived mesenchymal stromal cells (hBMSCs) on an appropriate tricalcium phosphate (TCP) scaffold offers a robust system for noninvasive therapy for spinal fusion. To show the efficacy of this approach, we identified a small molecule curcuminoid that when combined with TCP ceramic in the presence of hBMSCs selectively induced growth of bone cells: after 8- or 25-day incubations, alkaline phosphatase was elevated. Treatment of hBMSCs with curcuminoid 1 and TCP ceramic increased osteogenic target gene expression (i.e., Runx2, BMP2, Osteopontin, and Osteocalcin) over time. In the presence of curcuminoid 1 and TCP ceramic, osteogenesis of hBMSCs, including proliferation, differentiation, and mineralization, was observed. No evidence of chondrogenic or adipogenic potential using this protocol was observed. Transplantation of curcuminoid 1-treated hBMSC/TCP mixtures into the spine of immunodeficient rats showed that it achieved spinal fusion and provided greater stability of the spinal column than untreated hBMSC-TCP implants or TCP alone implants. On the basis of histological analysis, greater bone formation was associated with curcuminoid 1-treated hBMSC implants manifested as contiguous growth plates with extensive hematopoietic territories. Stimulation of hBMSCs by administration of small molecule curcuminoid 1 in the presence of TCP ceramic afforded an effective noninvasive strategy that increased spinal fusion repair and provided greater stability of the spinal column after 8 weeks in immunodeficient rats. Impact statement Bone defects only slowly regenerate themselves in humans. Current procedures to restore spinal defects are not always effective. Some have side effects. In this article, a new method to produce bone growth within 8 weeks in rats is presented. In the presence of tricalcium phosphate ceramic, curcuminoid-1 small molecule-stimulated human bone marrow-derived mesenchymal stromal cells showed robust bone cell growth in vitro. Transplantation of this mixture into the spine showed efficient spinal fusion in rats. The approach presented herein provides an efficient biocompatible scaffold for delivery of a potentially clinically useful system that could be applicable in patients.
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Affiliation(s)
- Daniel A Ryan
- Human BioMolecular Research Institute, San Diego, California, USA
| | - Jiongjia Cheng
- Human BioMolecular Research Institute, San Diego, California, USA
| | - Koichi Masuda
- Department of Orthopedic Surgery, University of California, San Diego, San Diego, California, USA
| | - John R Cashman
- Human BioMolecular Research Institute, San Diego, California, USA
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8
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Vrathasha V, Weidner H, Nohe A. Mechanism of CK2.3, a Novel Mimetic Peptide of Bone Morphogenetic Protein Receptor Type IA, Mediated Osteogenesis. Int J Mol Sci 2019; 20:E2500. [PMID: 31117181 PMCID: PMC6567251 DOI: 10.3390/ijms20102500] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 05/18/2019] [Accepted: 05/19/2019] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND Osteoporosis is a degenerative skeletal disease with a limited number of treatment options. CK2.3, a novel peptide, may be a potential therapeutic. It induces osteogenesis and bone formation in vitro and in vivo by acting downstream of BMPRIA through releasing CK2 from the receptor. However, the detailed signaling pathways, the time frame of signaling, and genes activated remain largely unknown. METHODS Using a newly developed fluorescent CK2.3 analog, specific inhibitors for the BMP signaling pathways, Western blot, and RT-qPCR, we determined the mechanism of CK2.3 in C2C12 cells. We then confirmed the results in primary BMSCs. RESULTS Using these methods, we showed that CK2.3 stimulation activated OSX, ALP, and OCN. CK2.3 stimulation induced time dependent release of CK2β from BMPRIA and concurrently CK2.3 colocalized with CK2α. Furthermore, CK2.3 induced BMP signaling depends on ERK1/2 and Smad1/5/8 signaling pathways. CONCLUSION CK2.3 is a novel peptide that drives osteogenesis, and we detailed the molecular sequence of events that are triggered from the stimulation of CK2.3 until the induction of mineralization. This knowledge can be applied in the development of future therapeutics for osteoporosis.
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Affiliation(s)
- Vrathasha Vrathasha
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA.
| | - Hilary Weidner
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA.
| | - Anja Nohe
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA.
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9
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Weber J, Polo S, Maspero E. HECT E3 Ligases: A Tale With Multiple Facets. Front Physiol 2019; 10:370. [PMID: 31001145 PMCID: PMC6457168 DOI: 10.3389/fphys.2019.00370] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 03/18/2019] [Indexed: 12/19/2022] Open
Abstract
Ubiquitination plays a pivotal role in several cellular processes and is critical for protein degradation and signaling. E3 ubiquitin ligases are the matchmakers in the ubiquitination cascade, responsible for substrate recognition. In order to achieve selectivity and specificity on their substrates, HECT E3 enzymes are tightly regulated and exert their function in a spatially and temporally controlled fashion in the cells. These characteristics made HECT E3s intriguing targets in drug discovery in the context of cancer biology.
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Affiliation(s)
- Janine Weber
- Fondazione Istituto FIRC di Oncologia Molecolare, Milan, Italy
| | - Simona Polo
- Fondazione Istituto FIRC di Oncologia Molecolare, Milan, Italy.,Dipartimento di Oncologia ed Emato-Oncologia, Università degli Studi di Milano, Milan, Italy
| | - Elena Maspero
- Fondazione Istituto FIRC di Oncologia Molecolare, Milan, Italy
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Abstract
Bone morphogenetic proteins (BMPs) constitute the largest subdivision of the transforming growth factor-β family of ligands. BMPs exhibit widespread utility and pleiotropic, context-dependent effects, and the strength and duration of BMP pathway signaling is tightly regulated at numerous levels via mechanisms operating both inside and outside the cell. Defects in the BMP pathway or its regulation underlie multiple human diseases of different organ systems. Yet much remains to be discovered about the BMP pathway in its original context, i.e., the skeleton. In this review, we provide a comprehensive overview of the intricacies of the BMP pathway and its inhibitors in bone development, homeostasis, and disease. We frame the content of the review around major unanswered questions for which incomplete evidence is available. First, we consider the gene regulatory network downstream of BMP signaling in osteoblastogenesis. Next, we examine why some BMP ligands are more osteogenic than others and what factors limit BMP signaling during osteoblastogenesis. Then we consider whether specific BMP pathway components are required for normal skeletal development, and if the pathway exerts endogenous effects in the aging skeleton. Finally, we propose two major areas of need of future study by the field: greater resolution of the gene regulatory network downstream of BMP signaling in the skeleton, and an expanded repertoire of reagents to reliably and specifically inhibit individual BMP pathway components.
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Affiliation(s)
- Jonathan W Lowery
- Division of Biomedical Science, Marian University College of Osteopathic Medicine , Indianapolis, Indiana ; and Department of Developmental Biology, Harvard School of Dental Medicine , Boston, Massachusetts
| | - Vicki Rosen
- Division of Biomedical Science, Marian University College of Osteopathic Medicine , Indianapolis, Indiana ; and Department of Developmental Biology, Harvard School of Dental Medicine , Boston, Massachusetts
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Bradford STJ, Ranghini EJ, Grimley E, Lee PH, Dressler GR. High-throughput screens for agonists of bone morphogenetic protein (BMP) signaling identify potent benzoxazole compounds. J Biol Chem 2019; 294:3125-3136. [PMID: 30602563 DOI: 10.1074/jbc.ra118.006817] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 12/27/2018] [Indexed: 12/31/2022] Open
Abstract
Bone morphogenetic protein (BMP) signaling is critical in renal development and disease. In animal models of chronic kidney disease (CKD), re-activation of BMP signaling is reported to be protective by promoting renal repair and regeneration. Clinical use of recombinant BMPs, however, requires harmful doses to achieve efficacy and is costly because of BMPs' complex synthesis. Therefore, alternative strategies are needed to harness the beneficial effects of BMP signaling in CKD. Key aspects of the BMP signaling pathway can be regulated by both extracellular and intracellular molecules. In particular, secreted proteins like noggin and chordin inhibit BMP activity, whereas kielin/chordin-like proteins (KCP) enhance it and attenuate kidney fibrosis or CKD. Clinical development of KCP, however, is precluded by its size and complexity. Therefore, we propose an alternative strategy to enhance BMP signaling by using small molecules, which are simpler to synthesize and more cost-effective. To address our objective, here we developed a small-molecule high-throughput screen (HTS) with human renal cells having an integrated luciferase construct highly responsive to BMPs. We demonstrate the activity of a potent benzoxazole compound, sb4, that rapidly stimulated BMP signaling in these cells. Activation of BMP signaling by sb4 increased the phosphorylation of key second messengers (SMAD-1/5/9) and also increased expression of direct target genes (inhibitors of DNA binding, Id1 and Id3) in canonical BMP signaling. Our results underscore the feasibility of utilizing HTS to identify compounds that mimic key downstream events of BMP signaling in renal cells and have yielded a lead BMP agonist.
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Affiliation(s)
- Shayna T J Bradford
- From the Department of Pathology and.,the Molecular and Cellular Pathology Graduate Program, School of Medicine, and
| | | | - Edward Grimley
- From the Department of Pathology and.,the Molecular and Cellular Pathology Graduate Program, School of Medicine, and
| | - Pil H Lee
- the Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109
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12
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Chen D, Gehringer M, Lorenz S. Developing Small-Molecule Inhibitors of HECT-Type Ubiquitin Ligases for Therapeutic Applications: Challenges and Opportunities. Chembiochem 2018; 19:2123-2135. [PMID: 30088849 PMCID: PMC6471174 DOI: 10.1002/cbic.201800321] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Indexed: 12/11/2022]
Abstract
The ubiquitin system regulates countless physiological and disease-associated processes and has emerged as an attractive entryway for therapeutic efforts. With over 600 members in the human proteome, ubiquitin ligases are the most diverse class of ubiquitylation enzymes and pivotal in encoding specificity in ubiquitin signaling. Although considerable progress has been made in the identification of small molecules targeting RING ligases, relatively little is known about the "druggability" of HECT (homologous to E6AP C terminus) ligases, many of which are critically implicated in human pathologies. A major obstacle to optimizing the few available ligands is our incomplete understanding of their inhibitory mechanisms and the structural basis of catalysis in HECT ligases. Here, we survey recent approaches to manipulate the activities of HECT ligases with small molecules to showcase the particular challenges and opportunities these enzymes hold as therapeutic targets.
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Affiliation(s)
- Dan Chen
- Rudolf Virchow Center for Experimental BiomedicineUniversity of WürzburgJosef-Schneider-Strasse 2, Haus D1597080WürzburgGermany
| | - Matthias Gehringer
- Institute of Pharmaceutical SciencesDepartment of Pharmaceutical/Medicinal ChemistryUniversity of TübingenAuf der Morgenstelle 872076TübingenGermany
| | - Sonja Lorenz
- Rudolf Virchow Center for Experimental BiomedicineUniversity of WürzburgJosef-Schneider-Strasse 2, Haus D1597080WürzburgGermany
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13
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Abstract
Bone morphogenetic proteins (BMPs) constitute the largest subdivision of the transforming growth factor (TGF)-β family of ligands and exert most of their effects through the canonical effectors Smad1, 5, and 8. Appropriate regulation of BMP signaling is critical for the development and homeostasis of numerous human organ systems. Aberrations in BMP pathways or their regulation are increasingly associated with diverse human pathologies, and there is an urgent and growing need to develop effective approaches to modulate BMP signaling in the clinic. In this review, we provide a wide perspective on diseases and/or conditions associated with dysregulated BMP signal transduction, outline the current strategies available to modulate BMP pathways, highlight emerging second-generation technologies, and postulate prospective avenues for future investigation.
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Affiliation(s)
- Jonathan W Lowery
- Division of Biomedical Science, Marian University College of Osteopathic Medicine, Indianapolis, Indiana 46222
| | - Vicki Rosen
- Department of Developmental Biology, Harvard School of Dental Medicine, Boston, Massachusetts 02115
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14
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Presciutti S, Boden S. BMP and Beyond: A 25-Year Historical Review of Translational Spine Research at Emory University. Spine Surg Relat Res 2018; 2:1-10. [PMID: 31440639 PMCID: PMC6698547 DOI: 10.22603/ssrr.2017-0063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Accepted: 10/19/2017] [Indexed: 11/24/2022] Open
Abstract
A high rate of symptomatic spinal pseudoarthrosis and a wide range of complications associated with the use of iliac crest bone graft (the gold standard) have prompted the spine surgery community to seek alternative options to promote spinal fusion. Emory University has been one of the global leaders in this endeavor. This invited review covers the last 25 years of Emory's contributions to translational spine research, focusing specifically on our work with bone morphogenetic proteins (BMP) and the BMP signaling pathway. As a result of this work, recombinant human BMP-2 is the only Food and Drug Administration approved biologic bone graft substitute. It has been shown to significantly increase spinal fusion rates across the spinal column because of its potent ability to stimulate local bone formation through the recruitment of mesenchymal stem cells. This review covers our development of animal models of spinal fusion, our body of work regarding the translation of BMP from the benchtop to the clinic, the discovery of LMP-1 and strategies to enhance cellular responsiveness to BMPs, and the design of various small molecule drugs that can enhance local bone formation.
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Affiliation(s)
- Steven Presciutti
- Department of Orthopedic Surgery, Emory University, Atlanta, Georgia, USA
| | - Scott Boden
- Department of Orthopedic Surgery, Emory University, Atlanta, Georgia, USA
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15
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Fernández I, Gavaia PJ, Laizé V, Cancela ML. Fish as a model to assess chemical toxicity in bone. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2018; 194:208-226. [PMID: 29202272 DOI: 10.1016/j.aquatox.2017.11.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 11/14/2017] [Accepted: 11/22/2017] [Indexed: 06/07/2023]
Abstract
Environmental toxicology has been expanding as growing concerns on the impact of produced and released chemical compounds over the environment and human health are being demonstrated. Among the toxic effects observed in organisms exposed to pollutants, those affecting skeletal tissues (osteotoxicity) have been somehow overlooked in comparison to hepato-, immune-, neuro- and/or reproductive toxicities. Nevertheless, sub-lethal effects of toxicants on skeletal development and/or bone maintenance may result in impaired growth, reduced survival rate, increased disease susceptibility and diminished welfare. Osteotoxicity may occur by acute or chronic exposure to different environmental insults. Because of biologically and technically advantagous features - easy to breed and inexpensive to maintain, external and rapid rate of development, translucent larvae and the availability of molecular and genetic tools - the zebrafish (Danio rerio) has emerged in the last decade as a vertebrate model system of choice to evaluate osteotoxicity. Different experimental approaches in fish species and analytical tools have been applied, from in vitro to in vivo systems, from specific to high throughput methodologies. Current knowledge on osteotoxicity and underlying mechanisms gained using fish, with a special emphasis on zebrafish systems, is reviewed here. Osteotoxicants have been classified into four categories according to the pathway involved in the transduction of the osteotoxic effects: activation/inhibition of membrane and/or nuclear receptors, alteration of redox condition, mimicking of bone constituents and unknown pathways. Knowledge on these pathways is also reported here as it may provide critical insights into the development, production and release of future chemical compounds with none or low osteotoxicity, thus promoting the green/environmental friendly chemistry.
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Affiliation(s)
- Ignacio Fernández
- Centre of Marine Sciences (CCMAR), University of Algarve, Campus de Gambelas, Faro, Portugal.
| | - Paulo J Gavaia
- Centre of Marine Sciences (CCMAR), University of Algarve, Campus de Gambelas, Faro, Portugal; Department of Biomedical Sciences and Medicine, University of Algarve, Campus de Gambelas, Faro, Portugal
| | - Vincent Laizé
- Centre of Marine Sciences (CCMAR), University of Algarve, Campus de Gambelas, Faro, Portugal
| | - M Leonor Cancela
- Centre of Marine Sciences (CCMAR), University of Algarve, Campus de Gambelas, Faro, Portugal; Department of Biomedical Sciences and Medicine, University of Algarve, Campus de Gambelas, Faro, Portugal; Algarve Biomedical Center (ABC), Universidade do Algarve, Campus de Gambelas, Faro, Portugal
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16
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Zhang G, Cheng X, Zhou G, Xue H, Shao S, Wang Z. New pathway of icariin-induced MSC osteogenesis: transcriptional activation of TAZ/Runx2 by PI3K/Akt. Open Life Sci 2017. [DOI: 10.1515/biol-2017-0027] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
AbstractIcariin has been demonstrated to stimulate mesenchymal stem cell (MSC) osteogensis and activate several signals, such as PI3K/Akt, but how the osteogenesis was sequentially mediated is unclear. Runx2 is one of the osteogenic regulators in MSC and is regulated by the TAZ gene. The purpose of this study was to investigate whether icariin-activated PI3K/Akt crosstalked with the TAZ-Runx2 pathway to regulate MSC osteogenesis. Adipose-derived MSCs were treated with icariin alone, together with TAZ silencing or PI3K/Akt inhibitor. Normal MSCs were used as a control. The activation of PI3K/Akt, expression of TAZ and downstream expression of Runx2 were analyzed. Induction of MSC osteogenesis under different treatments was detected. The results demonstrated that icariin treatment significantly activated PI3K/Akt and TAZ expression, as well as the downstream Runx2 expression. When activation of PI3K/Akt by icariin was inhibited by LY294002, upregulated TAZ expression was reversed, as well as the downstream expression of Runx2. Consequently, with the osteogenic counteracting effects of icariin on MSCs, inhibition of TAZ upregulation by siRNA did not significantly influence PI3K/ Akt activation in icariin-treated MSCs, but icariin-induced upregulation of Runx2 and osteogenic differentiation in MSCs was counteracted. It could be concluded from these findings that icariin treatment activated PI3K/Akt and further mediated the transcriptional activation of the TAZ/Runx2 pathway to induce osteogenic differentiation of MSCs.
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Affiliation(s)
- Guoying Zhang
- Department of Orthopedics, The General Hospital of Chinese People’s Liberation Army, 28 Fuxing Road, 100853, Beijing, China
| | - Xiaofei Cheng
- Shanghai Key Laboratory of Orthopaedic Implants, Departmemt of Orthopaedic Surgery, Ninth People’s Hospital, School of Medicine, Shanghai JiaoTong University, Shanghai, China
| | - Gongshe Zhou
- Department of Orthopedics, The Center Hospital of Zhoukou, Henan Province, China
| | - Huimin Xue
- The Third People’s Hospital of Jinan. 1 North Industrial Road, Wangsheren North Street, Jinan 250132, Shandong Province, China
| | - Shan Shao
- The Third People’s Hospital of Jinan. 1 North Industrial Road, Wangsheren North Street, Jinan 250132, Shandong Province, China
| | - Zheng Wang
- Department of Orthopedics, The General Hospital of Chinese People’s Liberation Army, 28 Fuxing Road, 100853, Beijing, China
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17
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Wu T, Shu T, Kang L, Wu J, Xing J, Lu Z, Chen S, Lv J. Icaritin, a novel plant-derived osteoinductive agent, enhances the osteogenic differentiation of human bone marrow- and human adipose tissue-derived mesenchymal stem cells. Int J Mol Med 2017; 39:984-992. [PMID: 28260001 DOI: 10.3892/ijmm.2017.2906] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 01/19/2017] [Indexed: 11/05/2022] Open
Abstract
For the treatment of diseases affecting bones using bone regenerative medicine, there is an urgent need to develop safe, inexpensive drugs that can strongly induce bone formation. In the present study, we systematically investigated the effects of icaritin, a metabolic product of icariin, on the osteogenic differentiation of human bone marrow‑derived mesenchymal stem cells (hBMSCs) and human adipose tissue‑derived stem cells (hADSCs) in vitro. After treatment with icaritin at concentrations of 10‑8-10‑5 M, hBMSCs and hADSCs were examined for alkaline phosphatase activity, osteocalcin (OC) secretion, matrix mineralization and expression levels of bone‑related mRNA and proteins. Data showed that icaritin at concentrations 10‑7-10‑5 M significantly increased alkaline phosphatase activity, OC secretion at different time points, and calcium deposition at day 21. In addition, icaritin upregulated the mRNA expression of genes for bone morphogenetic proteins (BMP‑2, ‑4 and ‑7), bone transcription factors (Runx2 and Dlx5) and bone matrix proteins (ALP, OC and Col‑1). Moreover, icaritin increased the protein levels of BMPs, Runx2 and OC, as detected by western blot analysis. These findings suggest that icaritin enhances the osteogenic differentiation of hBMSCS and hADSCs. Icaritin exerts its potent osteogenic effect possibly by directly stimulating the production of BMPs. Although the osteogenic activity of icaritin in vitro was inferior to that of rhBMP‑2, icaritin displayed better results than icariin. Moreover, the low cost, simple extraction procedure, and an abundance of icaritin make it appealing as a bone regenerative medicine.
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Affiliation(s)
- Tao Wu
- Department of Emergency, Guangdong Provincial Corps Hospital of the Chinese People's Armed Police Forces, Guangzhou Medical University, Guangzhou, Guangdong 510507, P.R. China
| | - Tao Shu
- Department of Spine Surgery, The Third Affiliated Hospital of Sun Yat‑sen University, Guangzhou, Guangdong 510630, P.R. China
| | - Le Kang
- Department of Orthopaedics, Wuyi TCM Hospital of Jiangmen City, The Sixth Affiliated Hospital of the Medicine College of Jinan University, Jiangmen, Guangdong 529031, P.R. China
| | - Jinhui Wu
- Department of Emergency, Guangdong Provincial Corps Hospital of the Chinese People's Armed Police Forces, Guangzhou Medical University, Guangzhou, Guangdong 510507, P.R. China
| | - Jianzhou Xing
- Department of Emergency, Guangdong Provincial Corps Hospital of the Chinese People's Armed Police Forces, Guangzhou Medical University, Guangzhou, Guangdong 510507, P.R. China
| | - Zhiqin Lu
- Department of Emergency, Guangdong Provincial Corps Hospital of the Chinese People's Armed Police Forces, Guangzhou Medical University, Guangzhou, Guangdong 510507, P.R. China
| | - Shuxiang Chen
- Department of Orthopaedics, Wuyi TCM Hospital of Jiangmen City, The Sixth Affiliated Hospital of the Medicine College of Jinan University, Jiangmen, Guangdong 529031, P.R. China
| | - Jun Lv
- Department of Emergency, Guangdong Provincial Corps Hospital of the Chinese People's Armed Police Forces, Guangzhou Medical University, Guangzhou, Guangdong 510507, P.R. China
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18
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A Survey of Strategies to Modulate the Bone Morphogenetic Protein Signaling Pathway: Current and Future Perspectives. Stem Cells Int 2016; 2016:7290686. [PMID: 27433166 PMCID: PMC4940573 DOI: 10.1155/2016/7290686] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 05/24/2016] [Indexed: 12/14/2022] Open
Abstract
Bone morphogenetic proteins (BMPs) constitute the largest subdivision of the TGF-β family of ligands and are unequivocally involved in regulating stem cell behavior. Appropriate regulation of canonical BMP signaling is critical for the development and homeostasis of numerous human organ systems, as aberrations in the BMP pathway or its regulation are increasingly associated with diverse human pathologies. In this review, we provide a wide-perspective on strategies that increase or decrease BMP signaling. We briefly outline the current FDA-approved approaches, highlight emerging next-generation technologies, and postulate prospective avenues for future investigation. We also detail how activating other pathways may indirectly modulate BMP signaling, with a particular emphasis on the relationship between the BMP and Activin/TGF-β pathways.
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19
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Feng L, Cook B, Tsai SY, Zhou T, LaFlamme B, Evans T, Chen S. Discovery of a Small-Molecule BMP Sensitizer for Human Embryonic Stem Cell Differentiation. Cell Rep 2016; 15:2063-75. [PMID: 27210748 DOI: 10.1016/j.celrep.2016.04.066] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 02/06/2016] [Accepted: 04/18/2016] [Indexed: 12/19/2022] Open
Abstract
Sorely missing from the "toolkit" for directed differentiation of stem/progenitor cells are agonists of the BMP-signaling pathway. Using a high-throughput chemical screen, we discovered that PD407824, a checkpoint kinase 1 (CHK1) inhibitor, increases the sensitivity of cells to sub-threshold amounts of BMP4. We show utility of the compound in the directed differentiation of human embryonic stem cells toward mesoderm or cytotrophoblast stem cells. Blocking CHK1 activity using pharmacological compounds or CHK1 knockout using single guide RNA (sgRNA) confirmed that CHK1 inhibition increases the sensitivity to BMP4 treatment. Additional mechanistic studies indicate that CHK1 inhibition depletes p21 levels, thereby activating CDK8/9, which then phosphorylates the SMAD2/3 linker region, leading to decreased levels of SMAD2/3 protein and enhanced levels of nuclear SMAD1. This study provides insight into mechanisms controlling the BMP/transforming growth factor beta (TGF-β) signaling pathways and a useful pharmacological reagent for directed differentiation of stem cells.
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Affiliation(s)
- Lingling Feng
- Key Laboratory of Pesticide and Chemical Biology (CCNU), Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, Hubei 430079, China; Department of Surgery, Weill Cornell Medical College, New York, NY 10065, USA
| | - Brandoch Cook
- Department of Surgery, Weill Cornell Medical College, New York, NY 10065, USA
| | - Su-Yi Tsai
- Department of Surgery, Weill Cornell Medical College, New York, NY 10065, USA
| | - Ting Zhou
- Department of Surgery, Weill Cornell Medical College, New York, NY 10065, USA
| | - Brooke LaFlamme
- Department of Surgery, Weill Cornell Medical College, New York, NY 10065, USA
| | - Todd Evans
- Department of Surgery, Weill Cornell Medical College, New York, NY 10065, USA.
| | - Shuibing Chen
- Department of Surgery, Weill Cornell Medical College, New York, NY 10065, USA.
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20
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Controlled release in vitro of icariin from gelatin/hyaluronic acid composite microspheres. Polym Bull (Berl) 2015. [DOI: 10.1007/s00289-015-1534-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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21
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Liu H, Pan H, Yang H, Wang J, Zhang K, Li X, Wang H, Ding W, Li B, Zheng Z. LIM mineralization protein-1 suppresses TNF-α induced intervertebral disc degeneration by maintaining nucleus pulposus extracellular matrix production and inhibiting matrix metalloproteinases expression. J Orthop Res 2015; 33:294-303. [PMID: 25336289 DOI: 10.1002/jor.22732] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 08/20/2014] [Indexed: 02/04/2023]
Abstract
Imbalanced metabolism of Nucleus pulposus (NP) extracellular matrix (ECM) is closely correlated to Intervertebral Disc Degenerative Disease. LIM mineralization protein-1 (LMP-1) has been proven to induce sulfated glycosaminoglycan (sGAG) production in NP and have an anti-inflammatory effect in pre-osteoclast. However, whether it has any effect on the NP ECM production and degradation under inflammatory stimulation has not been studied. In the current study, a TNF-α induced cell model was established in vitro. Lentivirus encoding LMP-1 (LV-LMP-1) and short heparin LMP-1 (LV-shLMP-1) were constructed to overexpress and knockdown LMP-1 expression in NP cells. LMP-1 mRNA level was regulated in a dose-dependent manner after transfection. LV-LMP-1 increased whereas LV-shLMP-1 decreased collagen II, aggrecan, versican expression, and sGAG production. LV-LMP-1 abolished while LV-shLMP-1 aggravated TNF-α mediated down-regulation of the above matrix genes via ERK1/2 activation. Moreover, LV-LMP-1 abrogated TNF-α induced MMP-3 and MMP-13 expression via inhibiting p65 translocation and MMP-3 and MMP-13 promoter activity. These results indicated that LMP-1 had an ECM production maintenance effect under inflammatory stimulation. This effect was via up-regulation of matrix genes expression at least partially through ERK1/2 activation, and down-regulation of MMPs expression through NF-κB inhibition.
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Affiliation(s)
- Hui Liu
- Department of Spine Surgery, The First Affiliated Hospital, Sun Yat-sen University, 58, Zhongshan 2nd Road, 510080, Guangzhou, China
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22
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Kyllönen L, D’Este M, Alini M, Eglin D. Local drug delivery for enhancing fracture healing in osteoporotic bone. Acta Biomater 2015; 11:412-34. [PMID: 25218339 DOI: 10.1016/j.actbio.2014.09.006] [Citation(s) in RCA: 109] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 08/30/2014] [Accepted: 09/04/2014] [Indexed: 01/08/2023]
Abstract
Fragility fractures can cause significant morbidity and mortality in patients with osteoporosis and inflict a considerable medical and socioeconomic burden. Moreover, treatment of an osteoporotic fracture is challenging due to the decreased strength of the surrounding bone and suboptimal healing capacity, predisposing both to fixation failure and non-union. Whereas a systemic osteoporosis treatment acts slowly, local release of osteogenic agents in osteoporotic fracture would act rapidly to increase bone strength and quality, as well as to reduce the bone healing period and prevent development of a problematic non-union. The identification of agents with potential to stimulate bone formation and improve implant fixation strength in osteoporotic bone has raised hope for the fast augmentation of osteoporotic fractures. Stimulation of bone formation by local delivery of growth factors is an approach already in clinical use for the treatment of non-unions, and could be utilized for osteoporotic fractures as well. Small molecules have also gained ground as stable and inexpensive compounds to enhance bone formation and tackle osteoporosis. The aim of this paper is to present the state of the art on local drug delivery in osteoporotic fractures. Advantages, disadvantages and underlying molecular mechanisms of different active species for local bone healing in osteoporotic bone are discussed. This review also identifies promising new candidate molecules and innovative approaches for the local drug delivery in osteoporotic bone.
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23
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Chen S, Ryan DA, Dwyer MA, Cashman JR. Synergistic effect of Wnt modulatory small molecules and an osteoinductive ceramic on C2C12 cell osteogenic differentiation. Bone 2014; 67:109-21. [PMID: 24998670 DOI: 10.1016/j.bone.2014.06.032] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Revised: 06/15/2014] [Accepted: 06/25/2014] [Indexed: 01/25/2023]
Abstract
Although osteoinductive ceramics can induce osteoblast differentiation in vitro and bone regeneration in vivo, their effects rely solely on the limited number of endogenous stem cells. More recently, ceramic carriers seeded with culture-expanded stem cells have been reported as implants capable of in vivo bone formation. However, effective and safe signaling agents that promote cell differentiation to the osteogenic lineage are still needed. In the present report, two osteogenic small-molecules THQ-1a and PP-9 were identified by testing a series of compounds for Runx2 and BMP2 expression in C2C12 cells. Compounds THQ-1a and PP-9 modulated Wnt signaling and enhanced the expression of molecular markers of osteoblast differentiation. To probe the utility of these compounds for use with ceramic cell implants, the effect of THQ-1a and PP-9 on C2C12 cell osteogenic differentiation was investigated in the presence of a tricalcium phosphate (TCP) ceramic. The effect of THQ-1a and PP-9 on markers such as Osteocalcin and Collagen I was significantly increased in the presence of TCP ceramic. Additionally, THQ-1a or PP-9 in the presence of TCP ceramic gave a synergistic increase in alkaline phosphatase activity in the differentiation of C2C12 cells. Taken together, the results suggest an approach to directing cell lineage commitment for bone regeneration by the application of small-molecule osteogenic agents to cells in the presence of osteoinductive ceramics.
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Affiliation(s)
- Sigeng Chen
- The Human BioMolecular Research Institute, San Diego, CA 92121, USA
| | - Daniel A Ryan
- The Human BioMolecular Research Institute, San Diego, CA 92121, USA.
| | - Mary A Dwyer
- The Human BioMolecular Research Institute, San Diego, CA 92121, USA
| | - John R Cashman
- The Human BioMolecular Research Institute, San Diego, CA 92121, USA
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24
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Abstract
Although several methods have been used in bone regeneration medicine, current methods still have many limitations. The tissue used for autogenous bone graft is limited and allograft has weak osteoinductive activity. Tissue engineering provides a good choice for bone regeneration. However, the growth factors needed have a high price and short half-life. Recently, a number of small molecules have been confirmed to have osteoinductive activity and some have been clinically used. Natural small molecules including decalpenic acid, flavonoids, quinones can be extracted from plants and others can be synthesized according to the structure designed or mimicking the structure of natural small molecules. Small molecules can act as co-activator of BMP2 pathway or activate Wnt pathway; others can be the inhibitors of NF-κB signaling pathway. This review gives an overview on the small molecules with osteoinductive activity and discusses the mechanism of the small molecules.
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25
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Measuring activity in the ubiquitin-proteasome system: from large scale discoveries to single cells analysis. Cell Biochem Biophys 2014; 67:75-89. [PMID: 23686610 DOI: 10.1007/s12013-013-9621-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The ubiquitin-proteasome system (UPS) is the primary pathway responsible for the recognition and degradation of misfolded, damaged, or tightly regulated proteins in addition to performing essential roles in DNA repair, cell cycle regulation, cell migration, and the immune response. While traditional biochemical techniques have proven useful in the identification of key proteins involved in this pathway, the implementation of novel reporters responsible for measuring enzymatic activity of the UPS has provided valuable insight into the effectiveness of therapeutics and role of the UPS in various human diseases such as multiple myeloma and Huntington's disease. These reporters, usually consisting of a recognition sequence fused to an analytical handle, are designed to specifically evaluate enzymatic activity of certain members of the UPS including the proteasome, E3 ubiquitin ligases, and deubiquitinating enzymes. This review highlights the more commonly used reporters employed in a variety of scenarios ranging from high-throughput screening of novel inhibitors to single cell microscopy techniques measuring E3 ligase or proteasome activity. Finally, a recent study is presented highlighting the development of a novel degron-based substrate designed to overcome the limitations of current reporting techniques in measuring E3 ligase and proteasome activity in patient samples.
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26
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Rodríguez-Évora M, García-Pizarro E, del Rosario C, Pérez-López J, Reyes R, Delgado A, Rodríguez-Rey JC, Évora C. Smurf1 Knocked-Down, Mesenchymal Stem Cells and BMP-2 in an Electrospun System for Bone Regeneration. Biomacromolecules 2014; 15:1311-22. [DOI: 10.1021/bm401854d] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | | | - Javier Pérez-López
- Department
of Molecular Biology, University of Cantabria, IFIMAV, Santander, Spain
| | | | | | - José C Rodríguez-Rey
- Department
of Molecular Biology, University of Cantabria, IFIMAV, Santander, Spain
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27
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HUANG JIANGUO, PANG LONG, CHEN ZHIRONG, TAN XIPENG. Dual-delivery of vancomycin and icariin from an injectable calcium phosphate cement-release system for controlling infection and improving bone healing. Mol Med Rep 2013; 8:1221-7. [DOI: 10.3892/mmr.2013.1624] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 07/23/2013] [Indexed: 11/06/2022] Open
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Wong E, Sangadala S, Boden SD, Yoshioka K, Hutton WC, Oliver C, Titus L. A novel low-molecular-weight compound enhances ectopic bone formation and fracture repair. J Bone Joint Surg Am 2013; 95:454-61. [PMID: 23467869 PMCID: PMC3748970 DOI: 10.2106/jbjs.l.00275] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Use of recombinant human bone morphogenetic protein-2 (rhBMP-2) is expensive and may cause local side effects. A small synthetic molecule, SVAK-12, has recently been shown in vitro to potentiate rhBMP-2-induced transdifferentiation of myoblasts into the osteoblastic phenotype. The aims of this study were to test the ability of SVAK-12 to enhance bone formation in a rodent ectopic model and to test whether a single percutaneous injection of SVAK-12 can accelerate callus formation in a rodent femoral fracture model. METHODS Collagen disks with rhBMP-2 alone or with rhBMP-2 and SVAK-12 were implanted in a standard athymic rat chest ectopic model, and radiographic analysis was performed at four weeks. In a second set of rats (Sprague-Dawley), SVAK-12 was percutaneously injected into the site of a closed femoral fracture. The fractures were analyzed radiographically and biomechanically (with torsional testing) five weeks after surgery. RESULTS In the ectopic model, there was dose-dependent enhancement of rhBMP-2 activity with use of SVAK-12 at doses of 100 to 500 μg. In the fracture model, the SVAK-12-treated group had significantly higher radiographic healing scores than the untreated group (p = 0.028). Biomechanical testing revealed that the fractured femora in the 200 to 250-μg SVAK-12 group were 43% stronger (p = 0.008) and 93% stiffer (p = 0.014) than those in the control group. In summary, at five weeks the femoral fracture group injected with SVAK-12 showed significantly improved radiographic and biomechanical evidence of healing compared with the controls. CONCLUSIONS A single local dose of a low-molecular-weight compound, SVAK-12, enhanced bone-healing in the presence of low-dose exogenous rhBMP-2 (in the ectopic model) and endogenous rhBMPs (in the femoral fracture model). CLINICAL RELEVANCE This study demonstrates that rhBMP-2 responsiveness can be enhanced by a novel small molecule, SVAK-12. Local application of anabolic small molecules has the potential for potentiating and accelerating fracture-healing. Use of this small molecule to lower required doses of rhBMPs might both decrease their cost and improve their safety profile.
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Affiliation(s)
- Eugene Wong
- Department of Orthopaedics, Alfred Health, P.O. Box 315, Prahram, VIC 3181, Australia. E-mail address:
| | - Sreedhara Sangadala
- VA Medical Center-Research Service, 1670 Clairmont Road, Decatur, GA 30033. E-mail address for S. Sangadala: . E-mail address for C. Oliver: . E-mail address for L. Titus:
| | - Scott D. Boden
- Emory Orthopaedic and Spine Center, 59 Executive Park South, Suite 3000, Atlanta, GA 30320. E-mail address for S.D. Boden: . E-mail address for W.C. Hutton:
| | - Katsuhito Yoshioka
- Department of Orthopaedic Surgery, Kanazawa University School of Medicine, Kanazawa, 920-8641, Japan. E-mail address:
| | - William C. Hutton
- Emory Orthopaedic and Spine Center, 59 Executive Park South, Suite 3000, Atlanta, GA 30320. E-mail address for S.D. Boden: . E-mail address for W.C. Hutton:
| | - Colleen Oliver
- VA Medical Center-Research Service, 1670 Clairmont Road, Decatur, GA 30033. E-mail address for S. Sangadala: . E-mail address for C. Oliver: . E-mail address for L. Titus:
| | - Louisa Titus
- VA Medical Center-Research Service, 1670 Clairmont Road, Decatur, GA 30033. E-mail address for S. Sangadala: . E-mail address for C. Oliver: . E-mail address for L. Titus:
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Lv HS, Han QQ, Ding XL, Zhou JL, Yang PS, Miao JY, Zhao BX. Synthesis and Discovery of Novel Pyrazole Carboxamide Derivatives as Potential Osteogenesis Inducers. Arch Pharm (Weinheim) 2012; 345:870-7. [DOI: 10.1002/ardp.201200180] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Revised: 06/20/2012] [Accepted: 06/27/2012] [Indexed: 11/06/2022]
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Fan J, Bi L, Wu T, Cao L, Wang D, Nan K, Chen J, Jin D, Jiang S, Pei G. A combined chitosan/nano-size hydroxyapatite system for the controlled release of icariin. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2012; 23:399-407. [PMID: 22083857 DOI: 10.1007/s10856-011-4491-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2011] [Accepted: 11/06/2011] [Indexed: 05/29/2023]
Abstract
Icariin, a plant-derived flavonol glycoside, has been proved as an osteoinductive agent for bone regeneration. For this reason, we developed an icariin-loaded chitosan/nano-sized hydroxyapatite (IC-CS/HA) system which controls the release kinetics of icariin to enhance bone repairing. First, by Fourier transform infrared spectroscopy, we found that icariin was stable in the system developed without undergoing any chemical changes. On the other hand, X-ray diffraction, scanning electron microscopy and mechanical test revealed that the introduction of icariin did not remarkably change the phase, morphology, porosity and mechanical strength of the CS/HA composite. Then the hydrolytic degradation and drug release kinetics in vitro were investigated by incubation in phosphate buffered saline solution. The results indicated that the icariin was released in a temporally controlled manner and the release kinetics could be governed by degradation of both chitosan and hydroxyapatite matrix. Finally the in vitro bioactivity assay revealed that the loaded icariin was biologically active as evidenced by stimulation of bone marrow derived stroma cell alkaline phosphatase activity and formation of mineralized nodules. This successful IC-CS/HA system offers a new delivery method of osteoinductive agents and a useful scaffold design for bone regeneration.
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Affiliation(s)
- Junjun Fan
- Institute of Orthopaedics and Traumatology, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
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The dose-effect of icariin on the proliferation and osteogenic differentiation of human bone mesenchymal stem cells. Molecules 2011; 16:10123-33. [PMID: 22146373 PMCID: PMC6264195 DOI: 10.3390/molecules161210123] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Revised: 11/28/2011] [Accepted: 11/30/2011] [Indexed: 01/13/2023] Open
Abstract
Icariin had been reported as a potential agent for osteogenesis, but the dose-effect relationship needed further research to realize the clinical application of icariin. We isolated and purified human bone mesenchymal stem cells (hBMSCs) and stimulated them with different concentrations of icariin. The cytotoxicity of icariin was evaluated by the methylthiazolytetrazolium (MTT) assay method. The proliferation and osteogenic differentiation of such hBMSCs were investigated for different concentrations of icariin. We found that icariin had a dose-dependent effect on the proliferation and osteogenic differentiation of hBMSCs in a suitable concentration range from 10−9 M to 10−6 M, but at concentrations above 10−5 M, the cytotoxicity limited its use. The extremely low cost of icariin and its high abundance make it appealing for bone regeneration.
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Retinoic acid induces myoblasts transdifferentiation into premeiotic Stra8-positive cells. Cell Biol Int 2011; 35:365-72. [PMID: 21091440 DOI: 10.1042/cbi20100610] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Spermatogonia and sperm-like cells can be derived in vitro via the addition of RA (retinoic acid) to pluripotent ES and EG cells. At present, however, these cells have not been derived from unipotent cells. Here, we have generated premeiotic Stra8-positive cells from C2C12 myoblasts following treatment with 10 μM all-trans-RA for 8 days. The differentiated C2C12 cells exhibited spherical morphology similar to spermatogonia, and they expressed gene markers of premeiosis, meiosis and postmeiosis. In addition, some of the transdifferentiated Stra8-positive cells had a tail-like phenotype. Flow cytometry results indicated that up to 20% of RA-induced C2C12 cells were Stra8-positive. Mvh (mouse vasa homologue) protein, a germ cell-specific ATP-dependent RNA helicase and Prm1 (protamine 1) were detected in transdifferentiated cells. The DNA content in induced C2C12 cells showed that Stra8-positive cells were diploid, suggesting that the myoblast transdifferentiation was in the premeiotic stage of spermatogenesis. The derivation of Stra8-positive cells from C2C12 myoblasts has important implications for studying unipotent cell differentiation. Furthermore, C2C12 myoblasts may provide a useful in vitro cell model to study signal transduction and transdifferentiation during RA treatments.
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Liu H, Liu Y, Viggeswarapu M, Zheng Z, Titus L, Boden SD. Activation of c-Jun NH(2)-terminal kinase 1 increases cellular responsiveness to BMP-2 and decreases binding of inhibitory Smad6 to the type 1 BMP receptor. J Bone Miner Res 2011; 26:1122-32. [PMID: 21542012 DOI: 10.1002/jbmr.296] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Bone morphogenetic protein 2 (BMP-2) plays a critical role in the differentiation of precursor cells and has been approved for clinical application to induce new bone formation. To date, unexpectedly high doses of recombinant BMP-2 have been required to induce bone healing in humans. Thus, enhancing cellular responsiveness to BMP-2 potentially has critically important clinical implications. BMP responsiveness may be modulated in part by cross-talk with other signaling pathways, including mitogen-activated protein kinases (MAPKs). c-Jun NH(2)-terminal kinase (JNK) is a MAPK that has been reported to be required for late-stage differentiation of preosteoblasts and BMP-2-induced differentiation of preosteoblasts and pleuripotent cells. In this study we determined that MC3T3-E1-clone 24 cells (MC-24) can be induced by BMP-2 to differentiate into mineralizing osteoblast cultures. Using this inducible system, we employed both JNK loss-of-function and gain-of-function reagents to make three key observations: (1) JNK is required for phosphorylation of Smad1 by BMP-2 and subsequent activation of Smad1 signaling and osteoblast differentiation, (2) JNK1, but not JNK2, is required for BMP-2-induced formation of mineralized nodules, and (3) JNK1 activation decreases binding of inhibitory Smad6 to the type I BMP receptor (BMPR-I) and reciprocally increases binding of Smad1, both observations that would increase responsiveness to BMP-2. Understanding this and other pathways that lead to increased cellular responsiveness to BMPs could greatly aid more cost-effective and safe clinical delivery of these important molecules.
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Affiliation(s)
- Hui Liu
- Atlanta Veterans Affairs Medical Center and Department of Orthopaedics, Emory University School of Medicine, Decatur, GA, USA
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A synthetic compound that potentiates bone morphogenetic protein-2-induced transdifferentiation of myoblasts into the osteoblastic phenotype. Mol Cell Biochem 2010; 349:97-106. [PMID: 21110071 DOI: 10.1007/s11010-010-0664-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Accepted: 11/15/2010] [Indexed: 10/18/2022]
Abstract
There is an urgent need to develop methods that lower costs of using recombinant human bone morphogenetic proteins (BMPs) to promote bone induction. In this study, we demonstrate the osteogenic effect of a low-molecular weight compound, SVAK-12, that potentiated the effects of BMP-2 in inducing transdifferentiation of C2C12 myoblasts into the osteoblastic phenotype. Here, we report a specific compound, SVAK-12, which was selected based on in silico screenings of small-molecule databases using the homology modeled interaction motif of Smurf1-WW2 domain. The enhancement of BMP-2 activity by SVAK-12 was characterized by evaluating a BMP-specific reporter activity and by monitoring the BMP-2-induced expression of mRNA for osteocalcin and alkaline phosphatase (ALP), which are widely accepted marker genes of osteoblast differentiation. Finally, we confirmed these results by also measuring the enhancement of BMP-2-induced activity of ALP. Smurf1 is an E3 ligase that targets osteogenic Smads for ubiquitin-mediated proteasomal degradation. Smurf1 is an interesting potential target to enhance bone formation based on the positive effects on bone of proteins that block Smurf1-binding to Smad targets or in Smurf1-/- knockout mice. Since Smads bind Smurf1 via its WW2 domain, we performed in silico screening to identify compounds that might interact with the Smurf1-WW2 domain. We recently reported the activity of a compound, SVAK-3. However, SVAK-3, while exhibiting BMP-potentiating activity, was not stable and thus warranted a new search for a more stable and efficacious compound among a selected group of candidates. In addition to being more stable, SVAK-12 exhibited a dose-dependent activity in inducing osteoblastic differentiation of myoblastic C2C12 cells even when multiple markers of the osteoblastic phenotype were parallelly monitored.
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Abstract
The homologous to the E6-associated protein carboxyl terminus (HECT) domain E3 ubiquitin ligase Smurf1 is the first E3 ligase to be implicated in regulating bone cell function. The involvement of Smurf1 in multiple signaling pathways and pathological conditions is presently an area of extensive scientific interest. This review highlights recent works exploring Smurf-regulated biological processes in bone cells and highlights recent discoveries surrounding the regulatory mechanisms modulating its catalytic activity and substrate recognition capability. Moreover, we discuss the relevance of targeting the HECT E3s through the development of small-molecule inhibitors as an anticancer therapeutic strategy.
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Affiliation(s)
- Lianping Xing
- Department of Pathology, University of Rochester School of Medicine, Rochester, New York 14642, USA
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