Plant-derived soybean peroxidase stimulates osteoblast collagen biosynthesis and matrix mineralization
Ontology highlight
ABSTRACT: Bone defects arising from fractures or disease represent a significant problem for surgeons to manage and are a substantial economic burden on the healthcare economy. Recent advances in the development of biomaterial substitutes provides an attractive alternative to the current “gold standard” autologous bone grafting. Despite on-going research, we are yet to identify cost effective biocompatible, osteo-inductive factors that stimulate controlled, accelerated bone regeneration.We have recently reported that enzymes with peroxidase activity possess previously unrecognised roles in extracellular matrix biosynthesis, angiogenesis and osteoclastogenesis, which are essential processes in bone remodelling and repair. Here, we report for the first time, that plant-derived soybean peroxidase (SBP) possesses pro-osteogenic ability by promoting collagen I biosynthesis and matrix mineralization of human osteoblasts in vitro. Mechanistically, SBP regulates osteogenic genes responsible for inflammation, extracellular matrix remodelling and ossification, which are necessary for normal bone healing. Furthermore, SBP was shown to have osteo-inductive properties, that when combined with commercially available biphasic calcium phosphate (BCP) granules can accelerate bone repair in a critical size long bone defect ovine model. Micro-CT analysis showed that SBP when combined with commercially available biphasic calcium phosphate (BCP) granules significantly increased bone formation within the defects as early as 4 weeks compared to BCP alone. Histomorphometric assessment demonstrated accelerated bone formation prominent at the defect margins and surrounding individual BCP granules, with evidence of intramembranous ossification. These results highlight the capacity of SBP to be an effective regulator of osteoblastic function and may be beneficial as a new and cost effective osteo-inductive agent to accelerate repair of large bone defects.
Project description:Neurogenic heterotopic ossifications are intramuscular bone formations developing following central nervous system injury. The pathophysiology is poorly understood and current treatments for this debilitating condition remain unsatisfying. Here we explored the role of miRNAs in a clinically relevant mouse model that combines muscle and spinal cord injury (SCI), and in patients’ cells. We found an osteo-suppressive miRNAs response in injured muscle that was hindered when the spinal cord injury was associated. In isolated fibro-adipogenic progenitors from damaged muscle (cells at the origin of ossification), spinal cord injury induced a downregulation of osteo-suppressive miRNAs while osteogenic markers were overexpressed. The overexpression of selected miRNAs in patient’s fibro-adipogenic progenitors inhibited mineralization and osteo-chondrogenic markers in vitro. Altogether, we highlighted an osteo-suppressive mechanism involving multiple miRNAs in response to muscle injury that prevents osteogenic commitment and which is ablated by the neurologic lesion in heterotopic ossification pathogenesis. This provides new research hypotheses for preventive treatments.
Project description:Osteogenesis imperfecta (OI) type V is the second most common form of OI, distinguished by hyperplastic callus formation and calcification of the interosseous membranes in addition to bone fragility. All patients carry a dominant pathogenic variant (c.-14C>T) in IFITM5. Here, we generated a conditional Rosa26 knock-in mouse model to study the mechanistic consequences of the recurrent mutation. Expression of the mutant Ifitm5 in osteo-chondroprogenitor or chondrogenic cells resulted in low bone mass and growth retardation. Mutant limbs showed impaired endochondral ossification, cartilage overgrowth, and abnormal growth plate architecture. The cartilage phenotype correlates with the pathology reported in OI type V patients. Surprisingly, expression of mutant Ifitm5 in matrix-synthesizing or mature osteoblasts caused no obvious skeletal abnormalities. In contrast, earlier expression in osteo-chondroprogenitors was associated with increase in the skeletal progenitor population within the periosteum. Mutant IFITM5 disrupts early skeletal homeostasis in part by activating ERK signaling and downstream SOX9 protein, and inhibition of these pathways partially rescued the phenotype in mutant animals. . Tracing of chondrogenic cells expressing the mutant Ifitm5 using the Ai9 reporter showed retention of Ai9+ cells in the growth plate and delayed migration to the bone shaft. RNA sequencing demonstrated enrichment for chondrogenic markers in the bone. These data identify the contribution of a defect in osteo-chondroprogenitor differentiation and not osteoblast function as a driver in the pathogenesis of OI type V.
Project description:In this study, we aimed to develop microphysiological osteochondral (OC) tissue chips derived from human induced pluripotent stem cells (iPSCs) to model the pathologies of OA. We first induced iPSCs into mesenchymal progenitor cells (iMPCs) and optimized the chondro- and osteo-inductive conditions for iMPCs. Then iMPCs were encapsulated into photocrosslinked gelatin scaffolds and cultured within a dual-flow bioreactor, in which the top stream was chondrogenic medium and the bottom stream was osteogenic medium. After 28 days of differentiation, biphasic OC tissue and monophasic chondral (CH) tissue chips were successfully generated and phenotypes were confirmed by real time RT-PCR. The OC tissues were cut into Top and Bottom (Bot), and both parts were compared with each other. CH tissue were compared with their phenotype on Day 0. Total RNA was extracted from the samples and processed for qPCR according to the manufacturer's instructions.
Project description:Objectives: This study aimed to identify a set of differentially expressed genes (DEGs) in dorsal root ganglions (DRGs) between bone cancer pain (BCP) and sham BCP rats using RNA-sequencing (RNA-Seq). Methods: We established a rat BCP model by implanting MRMT-1 cells into the bone marrow cavity of left tibia. RNA-Seq was used to screen related genes. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis and protein-protein interaction (PPI) network analysis were conducted to investigate the bioinformatics functions of DEGs and possible potential pathological mechanisms of BCP. Results: RNA-Seq of ipsilateral DRGs from model rats identified a total of 152 DEGs compared to sBCP rats. The expression changes of four randomly selected DEGs were verified by qPCR. Four significant signaling pathways have been found for BCP including MAPK signaling pathway, calcium signaling pathway, apelin signaling pathway and oxytocin signaling pathway. Cxcl13 in DRGs was identified as a key player in the BCP model by comparing with published datasets in classic pain models. A core set of genes contributed to BCP mechanism were sorted out by PPI network analysis. Conclusions: These altered mRNAs and signaling pathways might be potential therapeutic targets for BCP treatment, which can guide future research on the molecular mechanism of BCP.
Project description:In March 2006, murine Bone Marrow Stromal Cells (BMSC) were flown in the Soyuz 12S to the International Space Station to investigate the effects of microgravity on their osteogenic potential in a three-dimensional environment. BMSC were grown in porous bioceramic Skelite disks (Φ 9 mm x T 1.2 mm). The constructs were exposed to microgravity for ca. 8 days, then fixed for RNA extraction. While the flight experiment was performed in fully automated hardware inside the KUBIK incubator, one group of control samples were incubated inside manually operated hardwares (flight control), and the other control group was incubated under routine laboratory conditions (lab control). The altered gene expression profile was analyzed by Mouse Gene 1.0 ST array (Affymetrix) representing whole-transcript coverage. Each one of the 28853 genes is represented on the array by approximately 26 probes spread across the full length of the gene, providing a more complete and more accurate picture of gene expression than the 3â based expression array design. A few days of microgravity were sufficient to determinate, at least at the molecular level, an effect in the BMSC; this response expressed a stress condition able to determinate consequences on several compartments and cellular functions. In particular, it seems to promote a gene expression, known to be associated with neurogenic activity (e.g. axon guidance), perhaps promoting the BMSC capability to be committed in that direction. The osteo-induction, by dexamethasone-based medium, due to the short duration of stimulation, did not have the possibility to manifest itself at the phenotypic level but only partially at the molecular level. Keywords: gene expression array-based, count Comparison of microgravity effects on bone marrow stromal cells maintained both in growth and in osteo-inductive conditions.
Project description:Endochondral bone formation is orchestrated by growth factors produced by chondrocytes and deposited in cartilage matrix. Some of these factors were identified, but their complete list and relationship remains unknown. In this work the growth factors were isolated from calcified cartilage of costochondral junctions. The isolation involved hyaluronidase digestion, guanidinium hydrochloride (GuHCl) extraction, HCl decalcification and GuHCl extraction of decalcified matrix. Growth factors were purified by heparin chromatography and estimated by enzyme-linked immunosorbent assay (ELISA) or used for protein sequence analysis. Bone morphogenetic protein-7 (BMP-7), Growth/differentiation factor 5 (GDF-5), and NEL-like protein 1 (NELL-1) quantitatively dominated in material obtained in all steps of isolation. During ossification perivascular cells and septoclasts enter the cartilage and release growth factors stimulating osteoclastogenesis. Osteoclasts dissolve calcified cartilage and transport released factors needed for stimulation of osteoprogenitor cells. Presence of BMP-7, GDF-5 and NELL-1 at the site of initial bone formation may suggest that their synergistic action favors osteogenesis.
Project description:The skull vault is composed of frontal and parietal bones that are connected by flexible sutures that protect the growing brain. Intramembranous ossification in the prenatal skull vault starts by mid-gestation in the mouse, and sutures must remain flexible for normal growth and development. Therefore, the balance of bone formation and remodeling needs to be precisely controlled because premature ossification in the sutures causes craniosynostosis (CS) to develop. CS has a variable clinical presentation where two frontal bones may be fused together, or a frontal bone may be fused to a parietal bone. While most studies focus on the premature suture ossification, we hypothesized that the process of intramembranous ossification in the frontal and parietal bones contributes to the etiology of CS. By bulk RNASeq we identified 536 unique transcripts between the frontal and parietal compartments.Taken together, we propose that the frontal bone is more active in bone remodeling than the parietal bone, and this control is important for temporal onset of intramembranous ossification in the skull vault.
Project description:To investigate the alteration of bone marrow environment caused by Pinch loss, we performed single-cell RNA-sequencing on bone marrow cells, including hematopoietic cells and non-hematopietic stromal cells. As results indicated, we found both cell type proportion and transcriptomic signatures were dramatically altered by Pinch loss. We identified genes related to ossification, extracellular matrix organization, skeletal system development, and vasculature structure development were significantly differentially expressed between control group and dKO group in many mesenchymal stromal cells. Our results revealed Pinch loss disrupted homeostasis of bone marrow niche, monocytes in bone marrow were actively involved in inflammatory response, and functions of mesenchymal stromal cells was severely disrupted.
Project description:Histone deacetylase inhibitors are efficacious epigenetic-based therapies for some cancers and neurological disorders; however, these drugs inhibit multiple Hdacs and have detrimental effects on the pre- and post-natal skeleton. To better understand how Hdac inhibitors affect the skeleton, we focused on understanding the role of one of their targets, Hdac3, in endochondral bone formation by deleting it in immature murine chondrocyte micro masses with Adeno-Cre. Hdac3-deficient chondrocytes expressed higher levels of pro-inflammatory and matrix degrading genes (e.g., Il-6, Mmp3, Mmp13, Saa3) and lower levels of genes related to the extracellular matrix production, bone development and ossification (e.g., Acan, Col2a1, Ihh, Col10a1). Histone acetylation was increased in and around genes with elevated expression.
Project description:Histone deacetylase inhibitors are efficacious epigenetic-based therapies for some cancers and neurological disorders; however, these drugs inhibit multiple Hdacs and have detrimental effects on the pre- and post-natal skeleton. To better understand how Hdac inhibitors affect the skeleton, we focused on understanding the role of one of their targets, Hdac3, in endochondral bone formation by deleting it in immature murine chondrocyte micro masses with Adeno-Cre. Hdac3-deficient chondrocytes expressed higher levels of pro-inflammatory and matrix degrading genes (e.g., Il-6, Mmp3, Mmp13, Saa3) and lower levels of genes related to the extracellular matrix production, bone development and ossification (e.g., Acan, Col2a1, Ihh, Col10a1). Histone acetylation was increased in and around genes with elevated expression.