The role of oncostatin M regulates osteoblastic differentiation of dental pulp stem cells through STAT3 pathway

Oncostatin M: Dual Regulator of the Skeletal and Hematopoietic Systems

PURPOSE OF THE REVIEW

The bone and hematopoietic tissues coemerge during development and are functionally intertwined throughout mammalian life. Oncostatin M (OSM) is an inflammatory cytokine of the interleukin-6 family produced by osteoblasts, bone marrow macrophages, and neutrophils. OSM acts via two heterodimeric receptors comprising GP130 with either an OSM receptor (OSMR) or a leukemia inhibitory factor receptor (LIFR). OSMR is expressed on osteoblasts, mesenchymal, and endothelial cells and mice deficient for the Osm or Osmr genes have both bone and blood phenotypes illustrating the importance of OSM and OSMR in regulating these two intertwined tissues.

RECENT FINDINGS

OSM regulates bone mass through signaling via OSMR, adaptor protein SHC1, and transducer STAT3 to both stimulate osteoclast formation and promote osteoblast commitment; the effect on bone formation is also supported by action through LIFR. OSM produced by macrophages is an important inducer of neurogenic heterotopic ossifications in peri-articular muscles following spinal cord injury. OSM produced by neutrophils in the bone marrow induces hematopoietic stem and progenitor cell proliferation in an indirect manner via OSMR expressed by bone marrow stromal and endothelial cells that form hematopoietic stem cell niches. OSM acts as a brake to therapeutic hematopoietic stem cell mobilization in response to G-CSF and CXCR4 antagonist plerixafor. Excessive OSM production by macrophages in the bone marrow is a key contributor to poor hematopoietic stem cell mobilization (mobilopathy) in people with diabetes. OSM and OSMR may also play important roles in the progression of several cancers. It is increasingly clear that OSM plays unique roles in regulating the maintenance and regeneration of bone, hematopoietic stem and progenitor cells, inflammation, and skeletal muscles. Dysregulated OSM production can lead to bone pathologies, defective muscle repair and formation of heterotopic ossifications in injured muscles, suboptimal mobilization of hematopoietic stem cells, exacerbated inflammatory responses, and anti-tumoral immunity. Ongoing research will establish whether neutralizing antibodies or cytokine traps may be useful to correct pathologies associated with excessive OSM production.

Oncostatin M regulates macrophages polarization in osseointegration via yes-associated protein

OBJECTIVES

Oncostatin M(OSM), secreted by monocytes and macrophages, has been noted to participate in bone homeostasis and macrophage polarization, which might be regulated by yes-associated protein (YAP). This study aimed to elucidate the influence and mechanisms of OSM-YAP on macrophages polarization in osseointegration.

MATERIAL AND METHODS

In vitro, flow cytometry, real-time PCR, and Elisa were performed to evaluate inflammatory function in bone marrow-derived macrophages (BMDMs) with OSM, siOSMR, and YAP inhibitor verteporfin (VP). In vivo, macrophage-specific YAP-deficient mice were generated to investigate the role of OSM via YAP signaling in osseointegration.

RESULTS

This study demonstrated that OSM could inhibit the M1 polarization, promote the M2 polarization, and induce the expression of osteogenic-related factors via VP. The conditional knock-out of YAP inhibited the osseointegration in mice, and promoted the inflammatory reaction around the implants, while OSM could restore the effect.

CONCLUSIONS

Our results demonstrated that OSM might play an important role in the polarization of BMDMs, and bone formation around dental and femoral implants. This effect was closely conducted by Hippo-YAP pathway.

CLINICAL SIGNIFICANCE

Understanding the role and mechanism of OSM in macrophage polarization around dental implants could improve comprehension of signal network of osseointegration, and it might offer a potential target of therapies to accelerate osseointegration and reduce inflammatory reactions.

Transcriptomic Changes toward Osteogenic Differentiation of Mesenchymal Stem Cells on 3D-Printed GelMA/CNC Hydrogel under Pulsatile Pressure Environment

Biomimetic soft hydrogels used in bone tissue engineering frequently produce unsatisfactory outcomes. Here, it is investigated how human bone-marrow-derived mesenchymal stem cells (hBMSCs) differentiated into early osteoblasts on remarkably soft 3D hydrogel (70 ± 0.00049 Pa). Specifically, hBMSCs seeded onto cellulose nanocrystals incorporated methacrylate gelatin hydrogels are subjected to pulsatile pressure stimulation (PPS) of 5-20 kPa for 7 days. The PPS stimulates cellular processes such as mechanotransduction, cytoskeletal distribution, prohibition of oxidative stress, calcium homeostasis, osteogenic marker gene expression, and osteo-specific cytokine secretions in hBMSCs on soft substrates. The involvement of Piezo 1 is the main ion channel involved in mechanotransduction. Additionally, RNA-sequencing results reveal differential gene expression concerning osteogenic differentiation, bone mineralization, ion channel activity, and focal adhesion. These findings suggest a practical and highly scalable method for promoting stem cell commitment to osteogenesis on soft matrices for clinical reconstruction.

3D printed Ti-5Cu alloy accelerates osteogenic differentiation of MC3T3-E1 cells by stimulating the M2 phenotype polarization of macrophages

Ti-5Cu alloy has been proved to have excellent mechanical properties and cell compatibility and has certain antibacterial properties due to the addition of Cu. However, there are few studies on the effects of Ti-5Cu alloy on macrophage polarization and immune-related bone formation. In this study, we prepared Ti-5Cu alloy by three-dimensional printing technology and found that Ti-5Cu alloy presented a much smoother surface compared with Ti. In addition, the CCK-8 results indicated the Ti-5Cu alloy had no cytotoxicity to RAW264.7 cells by co-culture. The results of inductively coupled plasma mass spectrometry showed that the concentration of Cu²⁺ was 0.133 mg/L after 7 days of co-culture, and the CCK-8 results proved that Cu²⁺ had no cytotoxicity to RAW264.7 at this concentration. Then, we studied the effects of Ti-5Cu alloy on macrophage polarization; it was shown that the Ti-5Cu alloy is more prone to modulate the RAW264.7 polarization towards the M2 phenotype and the conditioned medium derived from Ti-5Cu alloy significantly promoted the proliferation and osteogenic differentiation of MC3T3-E1 cells. However, when the expression of Oncostatin M (OSM) gene of RAW264.7 was knocked down, the osteogenic differentiation of MC3T3-E1 cells was decreased. This suggests that the OSM secreted by RAW264.7 co-cultured with Ti-5Cu alloy could accelerate the osteogenic differentiation of MC3T3-E1 cells by acting on OSMR/gp130 receptors.

Adipokines in dental pulp: physiological, pathological, and potential therapeutic roles

BACKGROUND

Hundreds of adipokines have been identified, and their extensive range of endocrine functions-regulating distant organs such as oral tissues-and local autocrine/paracrine roles have been studied. In dentistry, however, adipokines are poorly known proteins in the dental pulp; few of them have been studied despite their large number. This study reviews recent advances in the investigation of dental-pulp adipokines, with an emphasis on their roles in inflammatory processes and their potential therapeutic applications.

HIGHLIGHTS

The most recently identified adipokines in dental pulp include leptin, adiponectin, resistin, ghrelin, oncostatin, chemerin, and visfatin. They have numerous physiological and pathological functions in the pulp tissue: they are closely related to pulp inflammatory mechanisms and actively participate in cell differentiation, mineralization, angiogenesis, and immune-system modulation.

CONCLUSION

Adipokines have potential clinical applications in regenerative endodontics and as biomarkers or targets for the pharmacological management of inflammatory and degenerative processes in dental pulp. A promising direction for the development of new therapies may be the use of agonists/antagonists to modulate the expression of the most studied adipokines.

Irradiation Haematopoiesis Recovery Orchestrated by IL-12/IL-12Rβ1/TYK2/STAT3-Initiated Osteogenic Differentiation of Mouse Bone Marrow-Derived Mesenchymal Stem Cells

Purpose

Repairing the irradiation-induced osteogenic differentiation injury of bone marrow mesenchymal stem cells (BM-MSCs) is beneficial to recovering haematopoiesis injury in radiotherapy; however, its mechanism is elusive. Our study aimed to help meet the needs of understanding the effects of radiotherapy on BM-MSC osteogenic potential.

Methods and Materials

Balb/c mice and the BM-MSCs were used to evaluate the irradiation-induced osteogenic differentiation injury in vivo. The cellular and molecular characterization were applied to determine the mechanism for recovery of irradiation-derived haematopoiesis injuries.

Results

We report a functional role of IL-12 in acute irradiation hematopoietic injury recovery and intend to dissect the possible mechanisms through BM-MSC, other than the direct effect of IL-12 on hematopoietic stem and progenitor cells (HSPCs). Specifically, we show that early use of IL-12 enhanced the osteogenic differentiation of BM-MSCs through IL-12Rβ1/TYK2/STAT3 signaling; furthermore, IL-12 induced osteogenesis facilitated bone formation and irradiation hematopoiesis recovery when transplanted BM-MSCs in the femur of Balb/c mice. For the mechanism of action, we found that IL-12 receptor beta 1 (IL-12Rβ1) expression of irradiated BM-MSCs was upregulated rapidly, coincidentally consistent with early use of IL-12 induced osteogenic differentiation enhancement. IL-12Rβ1 and tyrosine kinase 2 gene (Tyk2) silencing experiments and phosphotyrosine of signal transducer and activator of transcription 3 (p-STAT3) suppression experiments indicated the IL-12Rβ1/TYK2/STAT3 signaling was essential in IL-12-induced osteogenic differentiation enhancement of BM-MSCs.

Conclusion

These findings suggested that IL-12 may exert BM-MSCs-based hematopoietic recovery by repairing osteogenic differentiation abilities damages through IL-12Rβ1/TYK2/STAT3 signaling pathway post-irradiation.

Osteoinductive and antimicrobial mechanisms of graphene-based materials for enhancing bone tissue engineering

Graphene-based materials (GMs) have great application prospects in bone tissue engineering due to their osteoinductive ability and antimicrobial activity. GMs induce osteogenic differentiation through several mechanisms and pathways in bone tissue engineering. First of all, the surface and high hardness of the porous folds of graphene or graphene oxide (GO) can generate mechanical stimulation to initiate a cascade of reactions that promote osteogenic differentiation without any chemical inducers. In addition, change of the extracellular matrix (ECM), regulation of macrophage polarization, the oncostatin M (OSM) signaling pathway, the MAPK signaling pathway, the BMP signaling pathway, the Wnt/β-catenin signaling pathway, and other pathways are involved in GMs' regulation of osteogenesis. In bone tissue engineering, GMs prevent the formation of microbial biofilms mainly through preventing microbial adhesion and killing them. The former is mainly achieved by reducing surface free energy (SFE) and increasing hydrophobicity. The latter mainly includes oxidative stress and photothermal/photodynamic effects. Graphene and its derivatives (GDs) are mainly combined with bioactive ceramic materials, metal materials and macromolecular polymers to play an antimicrobial effect in bone tissue engineering. Concentration, number of layers, and type of GDs often affect the antimicrobial activity of GMs. In this paper, we reviewed relevant osteoinductive and antimicrobial mechanisms of GMs and their applications in bone tissue engineering.

Oncostatin M enhances osteogenic differentiation of dental pulp stem cells derived from supernumerary teeth

Supernumerary tooth (ST) may arise from uncertain developmental abnormalities or underlying genetic causes, and the extraction at the early age is recommended. Dental pulp stem cells (DPSCs) are the valuable resource for the regeneration of tooth and related craniofacial structures. DPSCs isolated from ST (sDPSCs) have not been fully characterized despite the potential in the applications. The objectives of this study are the efficient isolation of sDPSCs and the analysis of the properties as stem cells. sDPSCs were established by hammer-cracking and separation of the intact pulp from ST. sDPSCs in the culture were examined by light microscope and flow cytometer for the morphology and the surface marker expression. sDPSCs exhibited the cellular morphology of typical mesenchymal stem cells and expressed CD44, CD73, CD90, CD105 and CD166, but not CD14, CD34 or CD45. sDPSCs showed the differentiation potential toward osteogenic, chondrogenic and adipogenic lineages. During osteogenic differentiation, the stimulation by Oncostatin M enhanced the differentiation and significantly increased the expression of genes involved in the hard tissue repair, such as BMP2, BMP4, BMP6 and RUNX2. sDPSCs can be effectively derived from ST and displays the characteristics of mesenchymal stem cells in the maintenance and the differentiation. sDPSCs satisfies the quality as DPSCs thus provide the valuable resource to the regenerative therapy.

IL-21 promotes osteoblastic differentiation of human valvular interstitial cells through the JAK3/STAT3 pathway

Objectives: This study amied to whether IL-21 promotes osteoblast transdifferentiation of cultured human Valvular interstitial cells (VICs). Methods: We first confirmed that IL-21 alters gene expression between CAVD aortic valve tissue and normal samples by immunohistochemistry, qPCR, and western blotting. VICs were cultured and treated with IL-21. Gene and protein expression levels of the osteoblastic markers ALP and Runx2, which can be blocked by specific JAK3 inhibitors and/or siRNA of STAT3, were measured. Results: IL-21 expression was upregulated in calcified aortic valves and promotes osteogenic differentiation of human VICs. IL-21 accelerated VIC calcification through the JAK3/STAT3 pathway. Conclusion: Our data suggest that IL-21 is a key factor in valve calcification and a promising candidate for targeted therapeutics for CAVD.

Cellular hypoxia promotes osteogenic differentiation of mesenchymal stem cells and bone defect healing via STAT3 signaling

Background

Hypoxia in the vicinity of bone defects triggers the osteogenic differentiation of precursor cells and promotes healing. The activation of STAT3 signaling in mesenchymal stem cells (MSCs) has similarly been reported to mediate bone regeneration. However, the interaction between hypoxia and STAT3 signaling in the osteogenic differentiation of precursor cells during bone defect healing is still unknown.

Methods

In this study, we assessed the impact of different durations of CoCl₂-induced cellular hypoxia on the osteogenic differentiation of MSCs. Role of STAT3 signaling on hypoxia induced osteogenic differentiation was analyzed both in vitro and in vivo. The interaction between cellular hypoxia and STAT3 signaling in vivo was investigated in a mouse femoral bone defect model.

Results

The peak osteogenic differentiation and expression of vascular endothelial growth factor (VEGF) occurred after 3 days of hypoxia. Inhibiting STAT3 reversed this effect. Hypoxia enhanced the expression of hypoxia-inducible factor 1-alpha (HIF-1α) and STAT3 phosphorylation in MSCs. Histology and μ-CT results showed that CoCl₂ treatment enhanced bone defect healing. Inhibiting STAT3 reduced this effect. Immunohistochemistry results showed that CoCl₂ treatment enhanced Hif-1α, ALP and pSTAT3 expression in cells present in the bone defect area and that inhibiting STAT3 reduced this effect.

Conclusions

The in vitro study revealed that the duration of hypoxia is crucial for osteogenic differentiation of precursor cells. The results from both the in vitro and in vivo studies show the role of STAT3 signaling in hypoxia-induced osteogenic differentiation of precursor cells and bone defect healing.

Identification and Analysis of lncRNAs by Whole-Transcriptome Sequencing in Porcine Preadipocytes Induced by BMP2

Bone morphogenetic protein 2 (BMP2) can mediate the signaling of R-Smads and regulate different biological functions, including adipocyte differentiation. Long noncoding RNAs (lncRNAs) can be involved in many important biological processes, including fat metabolism, as miRNA sponges. This study aimed to investigate the molecular mechanism of fat deposition and to provide useful information for the prevention and treatment of lipid-related diseases. lncRNA sequencing was performed to compare and analyze, for the first time, the expression of lncRNAs in BMP2-induced and non-BMP2-induced preadipocytes from Junmu1 pigs. In addition, functional annotation and enrichment analysis of differentially expressed lncRNA target genes were carried out. lncRNAs and mRNAs were compared and analyzed. lncRNAs were identified that may regulate adipogenesis and lipid metabolism. The results give a theoretical basis for further studies on fat deposition mechanisms and provide potential therapeutic targets for metabolic diseases.

Immunomodulatory properties of graphene oxide for osteogenesis and angiogenesis

Background

The osteo-immunomodulatory properties of biomaterials play an important role in the outcomes of bone regeneration. Graphene oxide (GO) has been widely applied in many research fields due to its unique properties. However, the immunomodulatory properties of GO as a biomaterial for bone tissue engineering are still unclear.

Materials and methods

In this study, we evaluated the Inflammatory response of RAW264.7 cells influenced by GO. Then the osteogenic differentiation of BMSCs, and angiogenic differentiation of human umbilical vein endothelial cells (HUVECs) by stimulation with GO/RAW 264.7-conditioned culture medium were accessed. We also further investi gated the possible mechanisms underlying the osteo- and angio-immunomodulatory effects of GO.

Results

Our results showed that GO stimulates the secretion of oncostatin M, tumor necrosis factor alpha and other factors through the nuclear factor-κB pathway. GO/RAW264.7-conditioned medium promoted the osteogenic differentiation of BMSCs, stimulated upregulation of the HUVECs of vascular-related receptors, and promoted their tube formation in vitro.

Conclusion

In conclusion, our research shows that GO, as a biomaterial, can induce the formation of a beneficial osteo-immunomodulatory environment and is a promising biomaterial for bone tissue engineering.

Dental pulp stem cells and osteogenesis: an update

Dental pulp stem cells constitute an attractive source of multipotent mesenchymal stem cells owing to their high proliferation rate and multilineage differentiation potential. Osteogenesis is initiated by osteoblasts, which originate from mesenchymal stem cells. These cells express specific surface antigens that disappear gradually during osteodifferentiation. In parallel, the appearance of characteristic markers, including alkaline phosphatase, collagen type I, osteocalcin and osteopontin characterize the osteoblastic phenotype of dental pulp stem cells. This review will shed the light on the osteogenic differentiation potential of dental pulp stem cells and explore the culture medium components, and markers associated with osteodifferentiation of these cells.

Mesenchymal Stem Cells of Dental Origin for Inducing Tissue Regeneration in Periodontitis: A Mini-Review

Periodontitis is a chronic disease that begins with a period of inflammation of the supporting tissues of the teeth table and then progresses, destroying the tissues until loss of the teeth occurs. The restoration of the damaged dental support apparatus is an extremely complex process due to the regeneration of the cementum, the periodontal ligament, and the alveolar bone. Conventional treatment relies on synthetic materials that fill defects and replace lost dental tissue, but these approaches are not substitutes for a real regeneration of tissue. To address this, there are several approaches to tissue engineering for regenerative dentistry, among them, the use of stem cells. Mesenchymal stem cells (MSC) can be obtained from various sources of adult tissues, such as bone marrow, adipose tissue, skin, and tissues of the orofacial area. MSC of dental origin, such as those found in the bone marrow, have immunosuppressive and immunotolerant properties, multipotency, high proliferation rates, and the capacity for tissue repair. However, they are poorly used as sources of tissue for therapeutic purposes. Their accessibility makes them an attractive source of mesenchymal stem cells, so this review describes the field of dental stem cell research and proposes a potential mechanism involved in periodontal tissue regeneration induced by dental MSC.

The Role of Epithelial Stat3 in Amelogenesis during Mouse Incisor Renewal

The aim of this study was to evaluate the role of epithelial signal transducer and activator of transcription 3 (STAT3) in mouse incisor amelogenesis. Since Stat3 is expressed in the epithelial component of developing and adult mouse teeth, we generated and analyzed Krt14Cre/+;Stat3fl/fl mutant mice in which Stat3 was inactivated in epithelia including ameloblast progenitors and ameloblasts, the cells responsible for enamel formation. Histological analysis showed little enamel matrix in mutant incisors compared to controls. Delayed incisor enamel mineralization was demonstrated using micro-computed X-ray tomography analysis and was supported by an increase in the pre-expression distance of enamel-enriched proteins such as amelogenin, ameloblastin, and kallikrein-4. Lastly, scanning electron microscopy analysis showed little enamel mineralization in mutant incisors underneath the mesial root of the 1st molar; however, the micro-architecture of enamel mineralization was similar in the erupted portion of control and mutant incisors. Taken together, our findings demonstrate for the first time that the absence of epithelial Stat3 in mice leads to delayed incisor amelogenesis.