Osteogenesis Of Mesenchymal Stem Cells Research Articles

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The cover image is based on the Original Article MiR-26a-tetrahedral framework nucleic acids mediated osteogenesis of adipose-derived mesenchymal stem cells by Xiaoru Shao et al., https://doi.org/10.1111/cpr.13272.

Circ_0003204 regulates the osteogenic differentiation of human adipose-derived stem cells via miR-370-3p/HDAC4 axis

Human adipose-derived stem cells (hASCs) are a promising cell type for bone tissue regeneration. Circular RNAs (circRNAs) have been shown to play a critical role in regulating various cell differentiation and involve in mesenchymal stem cell osteogenesis. However, how circRNAs regulate hASCs in osteogenesis is still unclear. Herein, we found circ_0003204 was significantly downregulated during osteogenic differentiation of hASCs. Knockdown of circ_0003204 by siRNA or overexpression by lentivirus confirmed circ_0003204 could negatively regulate the osteogenic differentiation of hASCs. We performed dual-luciferase reporting assay and rescue experiments to verify circ_0003204 regulated osteogenic differentiation via sponging miR-370-3p. We predicted and confirmed that miR-370-3p had targets in the 3′-UTR of HDAC4 mRNA. The following rescue experiments indicated that circ_0003204 regulated the osteogenic differentiation of hASCs via miR-370-3p/HDAC4 axis. Subsequent in vivo experiments showed the silencing of circ_0003204 increased the bone formation and promoted the expression of osteogenic-related proteins in a mouse bone defect model, while overexpression of circ_0003204 inhibited bone defect repair. Our findings indicated that circ_0003204 might be a promising target to promote the efficacy of hASCs in repairing bone defects.

LncRNA BC083743 Silencing Exacerbated Osteoporosis by Regulating the miR-103-3p/SATB2 Axis to Inhibit Osteogenic Differentiation.

Objective The target of the present paper was to reveal the influence of LncRNA BC083743 on osteogenesis in human bone marrow mesenchymal stem cells (hBMSCs). Methods Serum specimens from osteoporotic patients and normal subjects were collected to isolate hBMSCs from femoral head tissue. The levels of BC083743 and miR-103-3p in serum and hBMSCs were measured by QRT-PCR. Alkaline phosphatase (ALP) activity test and alizarin red dyeing were used to identify ALP activity and mineralization forming ability of hBMSCs after transfection with si-BC083743 (siRNA-targeting BC083743). In addition, QRT-PCR and immunoblotting were conducted to identify the expressing levels of Runt-related transcription factor 2(Runx2), osteoprotegerin (OPG), and bone morphogenetic protein 2 (BMP2) in hBMSCs. Dual-luciferase reporter gene and RNA pull-down assays were employed to substantiate the binding of BC083743 to miR-103-3p and miR-103-3p to SATB2. Results BC083743 expression was significantly downregulated in sera from patients with osteoporosis, and osteogenic differentiation-related genes and BC083743 expression were obviously upregulated as the time to osteogenic differentiation increased. BC083743 knockdown hindered the osteogenic differentiation of hBMSCs. BC083743 was aimed at miR-103-3p and miR-103-3p inhibitors partially reversed the inhibitory effect of BC083743 downregulation on hBMSCs osteogenesis. BC083743 silencing downregulated SATB2 through uptake of miR-103-3p, thereby inhibiting hBMSCs osteogenesis to exacerbate osteoporosis. Conclusion BC083743/miR-103-3p/SATB2 axis inhibited osteogenic differentiation and exacerbated osteoporosis, which may offer brand-new molecular aims for the treatment of clinical osteoporosis.

Physically Cross-Linked DNA Hydrogel-Based Sustained Cytokine Delivery for In Situ Diabetic Alveolar Bone Rebuilding.

The development of a biodegradable and shape-adaptable bioscaffold that can enhance local cytokine retention and bioactivity is essential for the application of immunotherapy in periodontal diseases. Here, we report a biodegradable, anti-inflammatory, and osteogenic ILGel that uses a physically cross-linked DNA hydrogel as a soft bioscaffold for the long-term sustained release of cytokine interleukin-10 (IL-10) to accelerate diabetic alveolar bone rebuilding. Porous microstructures of ILGel favored the encapsulation of IL-10 and maintained IL-10 bioactivity for at least 7 days. ILGel can be gradually degraded or hydrolyzed under physiological conditions, avoiding the potential undesired side effects on dental tissues. Long-term sustained release of bioactive IL-10 from ILGel not only promoted M2 macrophage polarization and attenuated periodontal inflammation but also triggered osteogenesis of mesenchymal stem cells (MSCs), leading to accelerated alveolar bone formation and healing of alveolar bone defects under diabetic conditions in vivo. ILGel treatment significantly accelerated the defect healing rate of diabetic alveolar injury up to 93.42 ± 4.6% on day 21 post treatment compared to that of free IL-10 treatment (63.30 ± 7.39%), with improved trabecular architectures. Our findings imply the potential application of the DNA hydrogel as the bioscaffold for cytokine-based immunotherapy in diabetic alveolar bone injury and other periodontal diseases.

Silk-based hydrogel incorporated with metal-organic framework nanozymes for enhanced osteochondral regeneration.

Osteochondral defects (OCD) cannot be efficiently repaired due to the unique physical architecture and the pathological microenvironment including enhanced oxidative stress and inflammation. Conventional strategies, such as the control of implant microstructure or the introduction of growth factors, have limited functions failing to manage these complex environments. Here we developed a multifunctional silk-based hydrogel incorporated with metal-organic framework nanozymes (CuTA@SF) to provide a suitable microenvironment for enhanced OCD regeneration. The incorporation of CuTA nanozymes endowed the SF hydrogel with a uniform microstructure and elevated hydrophilicity. In vitro cultivation of mesenchymal stem cells (MSCs) and chondrocytes showed that CuTA@SF hydrogel accelerated cell proliferation and enhanced cell viability, as well as had antioxidant and antibacterial properties. Under the inflammatory environment with the stimulation of IL-1β, CuTA@SF hydrogel still possessed the potential to promote MSC osteogenesis and deposition of cartilage-specific extracellular matrix (ECM). The proteomics analysis further confirmed that CuTA@SF hydrogel promoted cell proliferation and ECM synthesis. In the full-thickness OCD model of rabbit, CuTA@SF hydrogel displayed successfully in situ OCD regeneration, as evidenced by micro-CT, histology (HE, S/O, and toluidine blue staining) and immunohistochemistry (Col I and aggrecan immunostaining). Therefore, CuTA@SF hydrogel is a promising biomaterial targeted at the regeneration of OCD.

Synergistic effects of fluid shear stress and adhesion morphology on the apoptosis and osteogenesis of mesenchymal stem cells.

Mechanical microenvironments, such as characteristics defining mechanical environments and fluid flow play an important role in steering the fate of mesenchymal stem cells (MSCs). However, the synergistic effect of adhesion morphology and fluid flow on the biological behavior of MSCs is seldom investigated. In this article, 0.5 or 0.8Pa fluid shear stress (FSS) was applied to the MSCs on micropatterned substrates, and the apoptosis and osteogenic differentiation of MSCs were measured by double fluorescent staining. Results showed that the cellular adhesion patterns with low circularity and large area are beneficial to the osteogenic differentiation of individual MSCs. Meanwhile, FSS facilitated osteogenic differentiation of MSCs, as shown by the expression of alkaline phosphatase, osteocalcin, and collagen I. In addition, nuclear transfer of Yes-associated protein, a transcriptional regulator in MSCs, was enhanced after being exposed to FSS. These results demonstrated the synergistic effects of FSS and adhesion morphology in directing the fate of MSCs, and these effects may be adopted to design bio-functional substrates for cell transplantation in tissue engineering.

Transfer of microRNA-22-3p by M2 macrophage-derived extracellular vesicles facilitates the development of ankylosing spondylitis through the PER2-mediated Wnt/β-catenin axis

Pathological osteogenesis and inflammation possess critical significance in ankylosing spondylitis (AS). The current study aimed to elucidate the mechanisms regarding extracellular vesicle (EV)-packaged microRNA-22-3p (miR-22-3p) from M2 macrophages in the osteogenic differentiation of mesenchymal stem cells (MSCs) in AS. EVs were initially isolated from M2 macrophages, which had been treated with either restored or depleted miR-22-3p. AS-BMSCs were subsequently treated with M2 macrophage-derived EVs to detect osteogenic differentiation in BMSCs using gain- or loss-of-function experiments. The binding affinity among miR-22-3p, period circadian protein 2 (PER2), and Wnt7b was identified. Finally, AS mouse models were established for testing the effects of M2-EV-miR-22-3p on the bone metastatic microenvironment in vivo. miR-22-3p from M2 macrophages could be transferred into BMSCs via EVs, which promoted the osteogenic differentiation of AS-BMSCs. miR-22-3p inhibited PER2, while PER2 blocked the Wnt/β-catenin signaling pathway via Wnt7b inhibition. M2-EV-shuttled miR-22-3p facilitated alkaline phosphatase activity and extracellular matrix mineralization via PER2-regulated Wnt/β-catenin axis, stimulating the BMSC osteogenic differentiation. Taken together, these findings demonstrate that miR-22-3p in M2 macrophage-released EVs downregulates PER2 to facilitate the osteogenesis of MSCs via Wnt/β-catenin axis.

LncRNA H19 mediates BMP9-induced angiogenesis in mesenchymal stem cells by promoting the p53-Notch1 angiogenic signaling axis

BMP9 mediated osteogenic differentiation mechanisms of MSCs were widely explored, however, mechanisms of BMP9-induced angiogenesis still need to be clarified. We previously characterized that Notch1 promoted BMP9-induced osteogenesis–angiogenesis coupling process in mesenchymal stem cells (MSCs). Here, we explored the underlying mechanisms of lncRNA H19 (H19) mediated regulation of BMP9-induced angiogenesis through activating Notch1 signaling. We demonstrated that basal expression level of H19 was high in MSCs, and silencing H19 attenuates BMP9-induced osteogenesis and angiogenesis of MSCs both in vitro and in vivo. Meanwhile, we identified that BMP9-induced production of CD31+ cells was indispensable for BMP9-induced bone formation, and silencing H19 dramatically blocked BMP9-induced production of CD31+ cells. In addition, we found that down-regulation of H19 inhibited BMP9 mediated blood vessel formation and followed subsequent bone formation in vivo. Mechanistically, we clarified that H19 promoted p53 phosphorylation by direct interacting and phosphorylating binding, and phosphorylated p53 potentiated Notch1 expression and activation of Notch1 targeting genes by binding on the promoter area of Notch1 gene. These findings suggested that H19 regulated BMP9-induced angiogenesis of MSCs by promoting the p53-Notch1 angiogenic signaling axis.

Prevention of collagen hydrogel contraction using polydopamine-coating and alginate outer shell increases cell contractile force.

Collagen is the most abundant protein in the extracellular matrix of mammals and has a great effect on various cell behaviors including adhesion, differentiation, and migration. However, it is difficult to utilize collagen gel as a physical scaffold in vitro because of its severe contraction. Decrease in the overall hydrogel volume induces changes in cell distribution, and mass transfer within the gel. Uncontrolled mechanical and physiological factors in the fibrous matrix result in uncontrolled cell behaviors in the surrounding cells. In this study, two strategies were used to minimize the contraction of collagen gel. A disk-shaped frame made of polydopamine-coated polydimethylsiloxane (PDMS) prevented horizontal contraction at the edge of the hydrogel. The sequentially cross-linked collagen gel with alginate outer shell (CA-shell) structure inhibited the vertical gel contraction. The combined method synergistically prevented the hydrogel from shrinkage in long-term 3D cell culture. We observed the shift in balance of differentiation from adipogenesis to osteogenesis in mesenchymal stem cells under the environment where gel contraction was prevented, and confirmed that this phenomenon is closely associated with the mechanotransduction based on Yes-associated protein (YAP) localization. Development of this contraction inhibition platform made it possible to investigate the influence of regulation of cellular microenvironments. The physical properties of the hydrogel fabricated in this study were similar to that of pure collagen gel but completely changed the cell behavior within the gel by inhibition of gel contraction. The platform can be used to broaden our understanding of the fundamental mechanism underlying cell-matrix interactions and reproduce extracellular matrix in vivo.

A bioactive porous scaffold containing collagen/ phosphorous-modified polycaprolactone for osteogenesis of adipose-derived mesenchymal stem cells

A biocompatible scaffold with appropriate physicochemical properties and efficient biological performance is the main component of bone tissue engineering. Here, we report the fabrication of collagen/P-PCL, a bioactive hybrid scaffold containing collagen and phosphorus-modified polycaprolactone (P-PCL). The phosphorylated polymer was synthesized and characterized by FT-IR spectroscopy. Porous scaffold prepared by mixing and cross-linking collagen and P-PCL solution, followed by freeze-drying method. The obtained hybrid scaffold was characterized by FT-IR and its morphology was observed by SEM. Density, porosity, swelling ratio, mechanical behavior, and degradability of the scaffold were assessed. Finally, biological responses of Adipose-derived Mesenchymal Stem Cells (AD-MSCs) seeded on the scaffold were evaluated. MTT assay revealed that the scaffold could be considered biocompatible. The scaffold was osteoconductive and efficiently support cell attachment and improved proliferation of AD-MSCs. Higher ALP activity and the appearance of more mineralized nodules on the collagen/P-PCL scaffold than in other test groups were concrete proof of the osteoinductivity of this scaffold. Moreover, real-time PCR analyses confirmed that the collagen/P-PCL scaffold was able to induce the AD-MSCs toward osteogenic differentiation. The results suggested that a biodegradable collagen/P-PCL scaffold holds potential for bone regeneration applications.

Kaempferol promotes the osteogenesis in rBMSCs via mediation of SOX2/miR-124-3p/PI3K/Akt/mTOR axis

BackgroundIt is reported that the osteogenesis in bone marrow mesenchymal stem cells (BMSCs) can alleviate osteoporosis progression. It has been found that Kae can promote the osteogenesis in BMSCs. However, the mechanism by which Kae mediates the osteogenesis in BMSCs is largely unknown. MethodsRBMSCs were collected from rats. The cytotoxicity of Kae was detected by CCK-8 assay. The osteogenic calcification in rBMSCs was measured by alizarin red staining, and ALP staining was performed to test the ALP activity in rBMSCs. The binding relationship between SOX2 and miR-124-3p was explored by dual luciferase report assay and Chromatin Immunoprecipitation (ChIP). RT-qPCR and western blot were performed to assess mRNA and protein levels, respectively. ResultsKae (10 μM) significantly increased the calcification, ALP activity, SOX2 level, activated PI3K/Akt/mTOR signaling and inhibited miR-124-3p level in rBMSCs, while knockdown of SOX2 reversed this phenomenon. Meanwhile, SOX2 suppressed the transcription of miR-124-3p, and SOX2 promoted the osteogenic differentiation in rBMSCs via regulation of miR-124-3p. MiR-124-3p could inactivate PI3K/Akt/mTOR to inhibit the osteogenic differentiation. ConclusionKae significantly promoted the osteogenesis in rBMSCs via mediation of SOX2/miR-124-3p/PI3K/Akt/mTOR axis. Thus, our study might shed new lights in exploring new methods against osteoporosis.

The chitosan/carboxymethyl cellulose/montmorillonite scaffolds incorporated with epigallocatechin-3-gallate-loaded chitosan microspheres for promoting osteogenesis of human umbilical cord-derived mesenchymal stem cell

Epigallocatechin-3-gallate (EGCG) is a plant-derived flavonoid compound with the ability to promote the differentiation of human bone marrow-derived mesenchymal stem cells (MSCs) into osteoblasts. However, the effect of EGCG on the osteogenic differentiation of the human umbilical cord-derived mesenchymal stem cells (HUMSCs) is rarely studied. Therefore, in this study, the osteogenic effects of EGCG are studied in the HUMSCs by detecting cell proliferation, alkaline phosphatase (ALP) activity, calcium deposition and the expression of relevant osteogenic markers. The results showed that EGCG can promote the proliferation and osteogenic differentiation of the HUMSCs in vitro at a concentration of 2.5–5.0 μM. Unfortunately, the EGCG is easily metabolized by cells during cell culture, which reduces its bioavailability. Therefore, in this paper, EGCG-loaded microspheres (ECM) were prepared and embedded in chitosan/carboxymethyl cellulose/montmorillonite (CS/CMC/MMT) scaffolds to form CS/CMC/MMT-ECM scaffolds for improving the bioavailability of EGCG. The HUMSCs were cultured on CS/CMC/MMT-ECM scaffolds to induce osteogenic differentiation. The results showed that the CS/CMC/MMT-ECM scaffold continuously released EGCG for up to 22 days. In addition, CS/CMC/MMT-ECM scaffolds can promote osteoblast differentiation. Taken together, the present study suggested that entrainment of ECM into CS/CMC/MMT scaffolds was a prospective scheme for promotion osteogenic differentiation of the HUMSCs.Graphical

Effect of miR-381-3p/FGF7 axis on the osteogenic differentiation of bone marrow mesenchymal stem cells through MEK/ERK signaling pathway

Although microRNAs (miRNAs) exert an important role in the osteogenesis of mesenchymal stem cells (MSCs), the effect of miR-381-3p on the osteogenic differentiation in MBD‑MSCs is still unclear. The BMMSCs from patients with MBD (MBD‑MSC) or normal participants (Normal‑MSC) were isolated and induced to differentiation with dexamethasone. BMMSCs were transfected with miR-381-3p mimic, miR-381-3p inhibitor, and FGF7 siRNA to regulate the expression of miR-381-3p or FGF7. The direct binding between miR-381-3p and FGF7 was predicted and confirmed by bioinformatics prediction and luciferase reporter assay. The effect of miR-381-3p on the osteogenic differentiation of BMMSCs was assessed by RT‑qPCR, alizarin Red S staining and western blot assays. Isolated BMMSCs showed the regular morphology, and were positive for CD44, CD90 and CD105 but negative for CD34 and CD45 markers. The calcium deposition and the relative mRNA expression levels of ALP, OC and OPN after induction were markedly enhanced. MiR-381-3p was upregulated in BMMSCs. Also, inhibition of miR-381-3p notably promoted osteogenic differentiation, vice versa. Besides, miR-381-3p could directly target FGF7 and negatively modulate the expression of FGF7. Moreover, inhibition of FGF7 attenuated the increase of the calcium deposition, and the relative mRNA expression of ALP, OC and OPN caused by the downregulation of miR-381-3p. In addition, the miR-381-3p inhibitor-induced the enhancement of the relative protein expressions of FGFR2, p-MEK and p-ERK1/2 were significantly reduced by the co-transfection of si-FGF7. Furthermore, the application of LY3214996, the inhibitor of ERK also verified these outcomes. MiR-381-3p directly targeting FGF7 modulated the osteogenic differentiation via MEK/ERK signaling pathway in BMMSCs.

In situ construction of flower-like nanostructured calcium silicate bioceramics for enhancing bone regeneration mediated via FAK/p38 signaling pathway

BackgroundThe repair of tissue defects has attracted considerable attention and remained a substantial challenge. Calcium silicate (CaSiO3, CS) bioceramics have attracted the interest of researchers due to their excellent biodegradability. Recent studies have demonstrated that nanoscale-modified bioactive materials with favorable biodegradability could promote bone tissue regeneration, providing an alternative approach for the repair of bone defects. However, the direct construction of biodegradable nanostructures in situ on CS bioceramics was still difficult.ResultsIn this study, flower-like nanostructures were flexibly prepared in situ on biodegradable CS bioceramics via hydrothermal treatment. The flower-like nanostructure surfaces exhibited better hydrophilicity and more significantly stimulated cell adhesion, alkaline phosphatase (ALP) activity, and osteogenic differentiation. Furthermore, the CS bioceramics with flower-like nanostructures effectively promoted bone regeneration and were gradually replaced with newly formed bone due to the favorable biodegradability of these CS bioceramics. Importantly, we revealed an osteogenesis-related mechanism by which the FAK/p38 signaling pathway could be involved in the regulation of bone mesenchymal stem cell (BMSC) osteogenesis by the flower-like nanostructure surfaces.ConclusionsFlower-like nanostructure surfaces on CS bioceramics exerted a strong effect on promoting bone repair and regeneration, suggesting their excellent potential as bone implant candidates for improving bone regeneration.Graphical

Integrative analysis reveals a lineage-specific circular RNA landscape for adipo-osteogenesis of human mesenchymal stem cells

BackgroundThe balance between osteogenesis and adipogenesis of mesenchymal stem cells (MSCs) is critical to skeletal development and diseases. As a research hotspot, circular RNAs (circRNAs) have expanded our understanding of a hidden layer of the transcriptome. Yet, their roles during adipo-osteogenesis remain poorly described.MethodsThe identity of human MSCs derived from bone marrow and adipose were first determined by flow cytometry, cellular staining, and quantitative polymerase chain reaction (qPCR). Multi-strategic RNA-sequencing was performed using Poly A, RiboMinus and RiboMinus/RNase R methods. Integrative analysis was performed to identify lineage-specific expressed circRNAs. The structural and expressional characteristics were identified by Sanger sequencing and qPCR, respectively. The regulatory effects of adipogenesis-specific circ-CRLF1 were confirmed using siRNA transcfection and qPCR.ResultsWe generated a whole transcriptome map during adipo-osteogenesis based on 10 Poly A, 20 RiboMinus and 20 RiboMinus/ RNase R datasets. A total of 31,326 circRNAs were identified and quantified from ~ 3.4 billion paired-end reads. Furthermore, the integrative analysis revealed that 1166 circRNA genes exhibited strong lineage-specific expression patterns. Their host genes were enriched in distinct biological functions, such as cell adhesion, cytokine signaling, and cell division. We randomly selected and validated the back-spliced junction sites and expression patterns of 12 lineage-specific circRNAs. Functional analysis indicated that circ-CRLF1 negatively regulated adipogenesis.ConclusionsOur integrative analysis reveals an accurate and generally applicable lineage-specific circRNA landscape for adipo-osteogenesis of MSCs and provides a potential therapeutic target, circ-CRLF1, for the treatment of skeleton-related disease.

Tough, Flexible, and Bioactive Amphoteric Copolymer-Based Hydrogel for Bone Regeneration without Encapsulation of Seed Cells/Simulating Cues.

Bone tissue scaffolds with good bulk or surface osteoconductivity are always pursued by biomaterial scientists. In this paper, we design a tough and flexible amphoteric copolymer-based (AC) hydrogel with bioactive groups for bone regeneration. In detail, our hydrogels are copolymerized with N-acyl glycinamide (NAGA), anionic acrylate alendronate (AcAln), and cationic (2-(acryloyloxy)ethyl) trimethyl ammonium chloride (DMAEA-Q) by free radical polymerization. There are three kinds of synergetic physical cross-links among our polyamphion hydrogels: (1) double hydrogen bonds between amide groups in NAGA to provide toughness, (2) hydrogen bonds between dual bisphosphite groups in AcAln, and (3) weak ionic pairs between the anionic bisphosphite groups and the cationic quaternary ammonium groups in DMAEA-Q to offer flexibility. The AC hydrogel shows osteoid-like viscoelasticity, which makes the AC hydrogel osteogenesis inductive. During the repairing process, the bioactive bisphosphite groups accelerate the calcium fixation to expedite the mineralization of the new-formed bone. At the same time, the surface charge property of AC hydrogels also prevents fibrous cyst formation, thus guaranteeing osseointegration. Our in vitro data strongly demonstrate that the AC hydrogel is an excellent matrix to induce osteogenesis of rat bone marrow mesenchymal stem cells. More importantly, the following in vivo experiments further prove that the AC hydrogel can reach satisfactory bone regeneration without encapsulation of seed cells or application of external simulating cues. These exciting results demonstrate that our AC hydrogel is a promising scaffold for bone regeneration. Our work can also inspire the constituent and structure design of biomaterial scaffolds for tissue regeneration.

LncRNA MEG3 promotes osteogenesis of hBMSCs by regulating miR-21-5p / SOD3 axis.

This study aimed to investigate the role of long non-coding (Lnc) RNA MEG3 on the osteogenesis of human bone marrow mesenchymal stem cells (hBMSCs). The binding of miR-21-5p to LncRNA MEG3 and SOD3 was determined using luciferase reporter assay; fluorescence quantitative PCR was used to detect the expression of LncRNA MEG3 at different induction times. hBMSCs were transfected with LncRNA MEG3 overexpression vector and induced for osteoblasts for 14 days. Alkaline phosphatase (ALP) staining, and alizarin red staining were used to detect bone differentiation, immunofluorescence assays were used to detect the expression of SOD3 and COL2A1. Luciferase reporter assay revealed that miR-21-5p bond to LncRNA MEG3 and SOD3. Flow cytometry analysis showed that hBMSCs were highly pure. After osteogenic induction for 14 days, compared with the control group, the overexpression of LncRNA MEG3 significantly increased the activity of ALP and enhanced the formation of calcium nodules in hBMSCs. The overexpression also increased the expression of COL2A1 and SOD3 significantly (P<0.05). LncRNA MEG3 can promote the osteogenesis and bone regeneration of hBMSCs and increasing the expression of SOD3 and COL2A1 via targeting the miR-21-5p/SOD3 axis.

Recent Advances in Enhancement Strategies for Osteogenic Differentiation of Mesenchymal Stem Cells in Bone Tissue Engineering.

Although bone is an organ that displays potential for self-healing after damage, bone regeneration does not occur properly in some cases, and it is still a challenge to treat large bone defects. The development of bone tissue engineering provides a new approach to the treatment of bone defects. Among various cell types, mesenchymal stem cells (MSCs) represent one of the most promising seed cells in bone tissue engineering due to their functions of osteogenic differentiation, immunomodulation, and secretion of cytokines. Regulation of osteogenic differentiation of MSCs has become an area of extensive research over the past few years. This review provides an overview of recent research progress on enhancement strategies for MSC osteogenesis, including improvement in methods of cell origin selection, culture conditions, biophysical stimulation, crosstalk with macrophages and endothelial cells, and scaffolds. This is favorable for further understanding MSC osteogenesis and the development of MSC-based bone tissue engineering.

METTL3-mediated LINC00657 promotes osteogenic differentiation of mesenchymal stem cells via miR-144-3p/BMPR1B axis

N6-methyladenosine (m6A) modification plays a crucial role in the progression of osteoporosis (OP). The study aimed to explore the effects of methyltransferase-like 3 (METTL3) in OP. The levels of METTL3, LINC00657, miR-144-3p and BMPR1B were detected using qPCR. Osteogenesis was assessed using alizarin red and alkaline phosphatase (ALP) staining assays. The protein expression of Bglap, Runx2 and Col1a1 was measured by western blot. The targets of LINC00657 and miR-144-3p were screened by bioinformatic analysis. The interaction between miR-144-3p and LINC00657 or BMPR1B was analyzed by dual-luciferase reporter assay and RNA pull-down assay. The results showed that METTL3 was downregulated in OP. METTL3 mediated m6A methylation of LINC00657 to promote the development of osteogenesis. Further study indicated that LINC00657 functioned as a ceRNA to upregulate BMPR1B via sponging miR-144-3p. Additionally, BMPR1B knockdown alleviated the effects of METTL3 on osteogenesis of bone marrow mesenchymal stem cells (BMSCs). Taken together, METTL3 facilitated osteogenic differentiation of BMSCs via the LINC00657/miR-144-3p/BMPR1B axis. Our findings may provide a novel insight of m6A methylation in the development of OP.

Therapeutic effect of platelet-rich plasma on glucocorticoid-induced rat bone marrow mesenchymal stem cells in vitro

BackgroundGlucocorticoid-induced osteonecrosis of the femoral head (GIONFH) is a progressive and disabling disease caused by long-term or high-dose glucocorticoid use. Decreased osteogenesis and proliferation of bone marrow mesenchymal stem cells (BMSCs) are the main pathogenesis of GIONFH. Platelet-rich plasma (PRP) has been shown to play a promising role in bone regeneration. However, the effects of PRP on glucocorticoid-induced BMSCs inhibition remains elusive. The objective of this study was to explore whether PRP could improve the in vitro biological activities of BMSCs inhibited by high-dose glucocorticoid in vitro.MethodsIn this study, a dexamethasone (Dex)-induced in vitro cell model was established. The effects of PRP on proliferation, migration, cell cycle and apoptosis of rat BMSCs induced with high-dose Dex compared to BMSCCTRL, using CCK-8 assay, transwell, flow cytometry and TUNEL assay, respectively. We further performed the alkaline phosphatase (ALP) and alizarin red (ALR) staining to explore the influence of PRP on osteogenic differentiation. Western Blot was used to detect the expression of Bcl-2, Caspase-3, RUNX2 apoptosis, and osteogenic-related proteins.ResultsWe observed increased apoptosis rate and Caspase-3 expression, and the decreased migration and osteogenic differentiation, and down-regulation of RUNX-2 and Bcl-2 expression in Dex-induced BMSCs. PRP could reverse these inhibitory effects of Dex, and enhance the BMSCs proliferation, migration, and osteogenic ability in vitro.ConclusionOur vitro study showed that PRP significantly protected BMSCs from Dex-induced apoptosis, and further promoted BMSCs proliferation, migration, and osteogenic differentiation. This study provides a scientific basis for the prevention and treatment of GIONFH with PRP. Meanwhile, it also lays the foundation for the application of PRP in other musculoskeletal diseases.