Bone-derived Cells Research Articles

An investigation into the cytotoxic effects of microbubbles and their constituents on osteosarcoma and bone marrow stromal cells

BackgroundUltrasound-responsive microbubbles offer a means of achieving minimally invasive, localised drug delivery in applications including regenerative medicine. To facilitate their use, however, it is important to determine any cytotoxic effects they or their constituents may have. The aim of this study was to test the hypothesis that phospholipid-shelled microbubbles are non-toxic to human bone-derived cells at biologically-relevant concentrations. MethodsMicrobubbles were fabricated using combinations of 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC), 1,2-dibehenoyl-sn-glycero-3-phosphocholine (DBPC), polyoxyethylene(40) stearate (PEG40S) and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene-glycol)-2000] (DSPE-PEG2000). Microbubble size and concentration were measured as a function of time and temperature by optical microscopy. Effects on MG63 osteosarcoma and human bone marrow stromal cells (BMSCs) were measured for up to 72 h by assay for viability, metabolic activity and proliferation. ResultsDBPC:DSPE-PEG2000 microbubbles were significantly more stable than DSPC:PEG40S microbubbles under all conditions tested. Serum-containing medium had no detrimental effect on microbubble stability, but storage at 37 °C compared to at 4 °C reduced stability for both preparations, with almost complete dissolution of microbubbles at times ≥24 h. DSPC:PEG40S microbubbles had greater inhibitory effects on cell metabolism and growth than DBPC:DSPE-PEG2000 microbubbles, with PEG40S found to be the principle inhibitory component. These effects were only evident at high microbubble concentrations (≥20% (v/v)) or with prolonged culture (≥24 h). Increasing cell-microbubble contact by inversion culture in a custom-built device had no inhibitory effect on metabolism. ConclusionsThese data indicate that, over a broad range of concentrations and incubation times, DBPC:DSPE-PEG2000 and DSPC:PEG40S microbubbles have little effect on osteoblastic cell viability and growth, and that PEG40S is the principle inhibitory component in the formulations investigated.

The osteogenic and mineralogenic potential of the microalgae Skeletonema costatum and Tetraselmis striata CTP4 in fish models

Skeletal disorders are problematic aspects for the aquaculture industry as skeletal deformities, which affect most species of farmed fish, increase production costs and affect fish welfare. Following recent findings that show the presence of osteoactive compounds in marine organisms, we evaluated the osteogenic and mineralogenic potential of commercially available microalgae strains Skeletonema costatum and Tetraselmis striata CTP4 in several fish systems. Ethanolic extracts increased extracellular matrix mineralization in gilthead seabream (Sparus aurata) bone-derived cell cultures and promoted osteoblastic differentiation in zebrafish (Danio rerio) larvae. Long-term dietary exposure to both extracts increased bone mineralization in zebrafish and upregulated the expression of genes involved in bone formation (sp7, col1a1a, oc1, and oc2), bone remodeling (acp5a), and antioxidant defenses (cat, sod1). Extracts also improved the skeletal status of zebrafish juveniles by reducing the incidence of skeletal anomalies. Our results indicate that both strains of microalgae contain osteogenic and mineralogenic compounds, and that ethanolic extracts have the potential for an application in the aquaculture sector as dietary supplements to support fish bone health. Future studies should also identify osteoactive compounds and establish whether they can be used in human health to broaden the therapeutic options for bone erosive disorders such as osteoporosis.

Histological and Immunological Evaluation of the Osteogenic Effects of Compact Bone-Delivered Stem Cell on Spongiosis Bone in the Rat Zygomatic Arch Defect Model.

In stem cell applications, apart from bone marrow and adipose tissue, compact bone is also used as an alternative. However, studies on this subject are limited. In our study, we investigated the effect of stem cell derived from compact bone on rat zygomatic arch defect. Fifteen rats were included in the study. Five rats were killed to obtain stem cells before the experiment. The rats were divided into 2 groups with 5 rats each. In group 1, compact bone-derived stem cell was applied. In group 2, adipose tissue-derived stem cell was applied. Right zygomatic arch defect was created in rats in both groups. Zygomatic bones were decellularized by cryosurgery. Stem cells were transferred to zygomatic bones. The number of stem cells, stem cell differentiation, and superficial markers obtained from the groups were examined. Histologically, cell structure, osteocyte count and osteopontin scores, elemental composition of the groups, percentages of resemblance to intact bone, osteocytes numbers, and cells were examined by electron microscopy of the bones in the groups after killing. The number of stem cells administered to the groups was 5 × 107 and 3.2 × 107 for group 1 and group 2, respectively (P > 0.05). Histologically, the morphology of the cells in group 1 was found to be healthier than group 2. The number of osteocytes was 97.56 ± 15.4 and 132.93 ± 10.8 in group 1 and group 2, respectively (P < 0.05). The osteopontin score was 3.47 ± 0.73 and 65 ± 0.64 in group 1 and group 2, respectively (P < 0.05). In the electron microscope examination, the morphologies of the cells in group 1 were seen more normal. The Ca/P ratio of the groups was 1.51 and 1.59 in group 1 and group 2, respectively (P > 0.05). Osteocyte counts were 10.7 ± 2.8 and 6.1 ± 1.2 in group 1 and group 2, respectively (P < 0.05). Morphological similarity percentages to normal bone were 88.4% and 79.6% in group 1 and group 2, respectively (P > 0.05). Stem cells obtained from compact bone gave positive results in zygomatic arch defect. This method can also be used as an alternative in stem cell applications.

Human alveolar bone-derived mesenchymal stem cell cultivation on a 3D-printed PDLLA scaffold for bone formation

This study aimed to assess effects of 3-dimensionally (3D) printed poly-d,l-lactin (PDLLA) on human alveolar bone-derived mesenchymal stem cell (h-ABMSC) osteogenic proliferation and differentiation. Human ABMSCs were cultured and identified using flow cytometry and morphological analysis. Control and PDLLA experimental groups were assessed using a Cell Counting Kit-8 (CCK-8) to detect cellular cytotoxicity and proliferative activity. Real-time quantitative polymerase chain reaction was used to determine expression levels of osteogenesis genes including alkaline phosphatase (ALP), Runt-related transcription factor 2 (Runx-2), osteopontin (OPN), and osteocalcin (OCN). The results showed that h-ABMSCs were successfully cultured and revealed by microscopic observation. Human ABMSCs were spindle-shaped, with clustered and fish-like primary cells. Cell surface markers were negative for CD34 and positive for CD44 and CD90. PDLLA had no cytotoxicity. Human ABMSCs proliferated normally, and osteogenic differentiation of the cells was observed on the surface of PDLLA. Cellular proliferative activity and expression levels of osteogenesis-related genes of PDLLA and control groups showed no significant difference, including ALP, Runx-2, OPN, and OCN. These results suggest that 3D-printed PDLLA has good cell compatibility and biological activity.

Icariin promotes the proliferation and osteogenic differentiation of bone-derived mesenchymal stem cells in patients with osteoporosis and T2DM by upregulating GLI-1

BackgroundThe function of mesenchymal stem cells (MSCs) from patients with osteoporosis (OP) is impaired and worsens in patients with type 2 diabetes mellitus (T2DM). Icariin (ICA) is the major active flavonoid glucoside isolated from traditional Chinese herbal Epimedium pubescens, and confirmed able to improve bone mass of OP patients.ObjectiveTo investigate the effect of ICA on the proliferation and osteogenic differentiation of bone-derived MSCs (BMSCs) from patients with OP and T2DM and uncover the potential mechanism.MethodsBMSCs were treated with ICA, and proliferation and osteogenic potency were evaluated using the 2,5-diphenyl-2H-tetrazolium bromide (MTT) assay and detection of osteogenic markers (ALP, RUNX2, SPP1, COL1A1, and mineralized nodules) was performed. RNA sequencing and bioinformatic analysis were performed to identify differentially expressed genes (DEGs) after ICA treatment and screen proliferation- and osteogenic differentiation-related processes. Gene gain and loss were performed to confirm the role of the key candidate gene.ResultsICA significantly promoted the proliferation and osteogenic differentiation of BMSCs. A total of 173 DEGs were identified after ICA treatment. Six DEGs (GLI-1, IGF2, BMP6, WNT5A, PTHLH, and MAPK14) enriched in both proliferation- and osteogenic differentiation-related processes were screened; GLI-1 had the highest validated |log2FC| value. Overexpression of GLI-1 enhanced the proliferation and osteogenic differentiation of BMSCs, and knockdown of GLI-1 weakened the positive effect of ICA on BMSCs.ConclusionICA promoted the proliferation and osteogenic differentiation of impaired BMSCs by upregulating GLI-1.

Nanoscale β-TCP-Laden GelMA/PCL Composite Membrane for Guided Bone Regeneration.

Major advances in the field of periodontal tissue engineering have favored the fabrication of biodegradable membranes with tunable physical and biological properties for guided bone regeneration (GBR). Herein, we engineered innovative nanoscale beta-tricalcium phosphate (β-TCP)-laden gelatin methacryloyl/polycaprolactone (GelMA/PCL-TCP) photocrosslinkable composite fibrous membranes via electrospinning. Chemo-morphological findings showed that the composite microfibers had a uniform porous network and β-TCP particles successfully integrated within the fibers. Compared with pure PCL and GelMA/PCL, GelMA/PCL-TCP membranes led to increased cell attachment, proliferation, mineralization, and osteogenic gene expression in alveolar bone-derived mesenchymal stem cells (aBMSCs). Moreover, our GelMA/PCL-TCP membrane was able to promote robust bone regeneration in rat calvarial critical-size defects, showing remarkable osteogenesis compared to PCL and GelMA/PCL groups. Altogether, the GelMA/PCL-TCP composite fibrous membrane promoted osteogenic differentiation of aBMSCs in vitro and pronounced bone formation in vivo. Our data confirmed that the electrospun GelMA/PCL-TCP composite has a strong potential as a promising membrane for guided bone regeneration.

Induction of Reactive Bone Stromal Fibroblasts in 3D Models of Prostate Cancer Bone Metastases.

A dynamic interplay between prostate cancer (PCa) cells and reactive bone stroma modulates the growth of metastases within the bone microenvironment. Of the stromal cells, metastasis-associated fibroblasts (MAFs) are known to contribute but are the least studied cell type in PCa tumour progression. It is the aim of the current study to establish a biologically relevant 3D in vitro model that mimics the cellular and molecular profiles of MAFs found in vivo. Using 3D in vitro cell culture models, the bone-derived fibroblast cell line, HS-5, was treated with conditioned media from metastatic-derived PCa cell lines, PC3 and MDA-PCa 2b, or mouse-derived fibroblasts 3T3. Two corresponding reactive cell lines were propagated: HS5-PC3 and HS5-MDA, and evaluated for alterations in morphology, phenotype, cellular behaviour, plus protein and genomic profiles. HS5-PC3 and HS5-MDA displayed distinct alterations in expression levels of N-Cadherin, non-functional E-Cadherin, alpha-smooth muscle actin (α-SMA), Tenascin C, and vimentin, along with transforming growth factor receptor expression (TGF β R1 and R2), consistent with subpopulations of MAFs reported in vivo. Transcriptomic analysis revealed a reversion of HS5-PC3 towards a metastatic phenotype with an upregulation in pathways known to regulate cancer invasion, proliferation, and angiogenesis. The exploitation of these engineered 3D models could help further unravel the novel biology regulating metastatic growth and the role fibroblasts play in the colonisation process.

Nanostructured bioactive glasses: A bird's eye view on cancer therapy.

Bioactive glasses (BGs) arewell known for their successful applications in tissue engineering and regenerative medicine. Recent experimental studies have shown their potential usability in oncology, either alone or in combination with other biocompatible materials, such as biopolymers. Direct contact with BG particles has been found to cause toxicity and death in specific cancer cells (bone-derived neoplastic stromal cells) in vitro. Nanostructured BGs (NBGs) can be doped with anticancer elements, such as gallium, to enhance their toxic effects against tumor cells. However, the molecular mechanisms and intracellular targets for anticancer compositions of NBGs require further clarification. NBGs have been successfully evaluated for use in various well-established cancer treatment strategies, including cancer hyperthermia, phototherapy, and anticancer drug delivery. Existing results indicate that NBGs not only enhance cancer cell death, but can also participate in the regeneration of lost healthy tissues. However, the application of NBGs in oncology is still in its early stages, and numerous unanswered questions must be addressed. For example, the impact of the composition, biodegradation, size, and morphology of NBGs on their anticancer efficacy should be defined for each type of cancer and treatment strategy. Moreover, it should be more clearly assessed whether NBGs can shrink tumors, slow/stop cancer progression, or cure cancer completely. In this regard, the use of computational studies (in silico methods) is highly recommended to design the most effective glass formulations for cancer therapy approaches and to predict, to some extent, the relevant properties, efficacy, and outcomes. This article is categorized under: Implantable Materials and Surgical Technologies > Nanomaterials and Implants Implantable Materials and Surgical Technologies > Nanotechnology in Tissue Repair and Replacement Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Exosomes derived from mesenchymal stromal cells promote bone regeneration by delivering miR-182–5p-inhibitor

Exosomes, small extracellular vesicles that function as a key regulator of cell-to-cell communication, are emerging as a promising candidate for bone regeneration. Here, we aimed to investigate the effect of exosomes from pre-differentiated human alveolar bone-derived bone marrow mesenchymal stromal cells (AB-BMSCs) carrying specific microRNAs on bone regeneration. Exosomes secreted from AB-BMSCs pre-differentiated for 0 and 7 days were cocultured with BMSCs in vitro to investigate their effect on the differentiation of the BMSCs. MiRNAs from AB-BMSCs at different stages of osteogenic differentiation were analyzed. BMSCs seeded on poly-L-lactic acid(PLLA) scaffolds were treated with miRNA antagonist-decorated exosomes to verify their effect on new bone regeneration. Exosomes pre-differentiated for 7 days effectively promoted the differentiation of BMSCs. Bioinformatic analysis revealed that miRNAs within the exosomes were differentially expressed, including the upregulation of osteogenic miRNAs (miR-3182, miR-1468) and downregulation of anti-osteogenic miRNAs (miR-182–5p, miR-335–3p, miR-382–5p), causing activation of the PI3K/Akt signaling pathway. The treatment of BMSC-seeded scaffolds with anti-miR-182–5p decorated exosomes demonstrated enhanced osteogenic differentiation and efficient formation of new bone. In conclusion, Osteogenic exosomes secreted from pre-differentiated AB-BMSCs were identified and the gene modification of exosomes provides great potential as a bone regeneration strategy. Data Availability StatementData generated or analyzed in this paper partly are available in the GEO public data repository(http://www.ncbi.nlm.nih.gov/geo).

Potential of Oral Cavity Stem Cells for Bone Regeneration: A Scoping Review

Bone loss is a common problem that ranges from small defects to large defects after trauma, surgery, or congenital malformations. The oral cavity is a rich source of mesenchymal stromal cells (MSCs). Researchers have documented their isolation and studied their osteogenic potential. Therefore, the objective of this review was to analyze and compare the potential of MSCs from the oral cavity for use in bone regeneration. Methods: A scoping review was carried out following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines. The databases reviewed were PubMed, SCOPUS, Scientific Electronic Library Online (SciELO), and Web of Science. Studies using stem cells from the oral cavity to promote bone regeneration were included. Results: A total of 726 studies were found, of which 27 were selected. The MSCs used to repair bone defects were (I) dental pulp stem cells of permanent teeth, (II) stem cells derived from inflamed dental pulp, (III) stem cells from exfoliated deciduous teeth, (IV) periodontal ligament stem cells, (V) cultured autogenous periosteal cells, (VI) buccal fat pad-derived cells, and (VII) autologous bone-derived mesenchymal stem cells. Stem cells associate with scaffolds to facilitate insertion into the bone defect and to enhance bone regeneration. The biological risk and morbidity of the MSC-grafted site were minimal. Successful bone formation after MSC grafting has been shown for small defects with stem cells from the periodontal ligament and dental pulp as well as larger defects with stem cells from the periosteum, bone, and buccal fat pad. Conclusions: Stem cells of maxillofacial origin are a promising alternative to treat small and large craniofacial bone defects; however, an additional scaffold complement is required for stem cell delivery.

Spontaneous spheroids from alveolar bone-derived mesenchymal stromal cells maintain pluripotency of stem cells by regulating hypoxia-inducible factors

BackgroundSpontaneous spheroid culture is a novel three-dimensional (3D) culture strategy for the rapid and efficient selection of progenitor cells. The objectives of this study are to investigate the pluripotency and differentiation capability of spontaneous spheroids from alveolar bone-derived mesenchymal stromal cells (AB-MSCs); compare the advantages of spontaneous spheroids to those of mechanical spheroids; and explore the mechanisms of stemness enhancement during spheroid formation from two-dimensional (2D) cultured cells.MethodsAB-MSCs were isolated from the alveolar bones of C57BL/6 J mice. Spontaneous spheroids formed in low-adherence specific culture plates. The stemness, proliferation, and multi-differentiation capacities of spheroids and monolayer cultures were investigated by reverse transcription quantitative polymerase chain reaction (RT-qPCR), immunofluorescence, alkaline phosphatase (ALP) activity, and oil-red O staining. The pluripotency difference between the spontaneous and mechanical spheroids was analyzed using RT-qPCR. Hypoxia-inducible factor (HIFs) inhibition experiments were performed to explore the mechanisms of stemness maintenance in AB-MSC spheroids.ResultsAB-MSCs successfully formed spontaneous spheroids after 24 h. AB-MSC spheroids were positive for MSC markers and pluripotency markers (Oct4, KLF4, Sox2, and cMyc). Spheroids showed higher Ki67 expression and lower Caspase3 expression at 24 h. Under the corresponding conditions, the spheroids were successfully differentiated into osteogenic and adipogenic lineages. AB-MSC spheroids can induce neural-like cells after neurogenic differentiation. Higher expression of osteogenic markers, adipogenic markers, and neurogenic markers (NF-M, NeuN, and GFAP) was found in spheroids than in the monolayer. Spontaneous spheroids exhibited higher stemness than mechanical spheroids did. HIF-1α and HIF-2α were remarkably upregulated in spheroids. After HIF-1/2α-specific inhibition, spheroid formation was significantly reduced. Moreover, the expression of the pluripotency genes was suppressed.ConclusionsSpontaneous spheroids from AB-MSCs enhance stemness and pluripotency. HIF-1/2α plays an important role in the stemness regulation of spheroids. AB-MSC spheroids exhibit excellent multi-differentiation capability, which may be a potent therapy for craniomaxillofacial tissue regeneration.

BMP-2 transgenic alveolar bone-derived marrow stem cells attenuate osteonecrosis of the femoral head

Background: Osteonecrosis of the femoral head (ONFH) results in activity-related hip pain and disability, affecting around 20 million people worldwide. However, there is absent of effective therapeutic approaches for ONFH. The transplantation of mesenchymal stem cells was reported to be a promising method for ONFH therapy. In this study, we explored if bone morphogenetic protein-2 (BMP-2) transgenic alveolar bone-derived marrow stem cells (ABMSCs) could be applied to treat ONFH.&#x0D; Methods: We established an ONFH mouse model by injection of steroid, and implanted ABMSCs and BMP-2 transgenic ABMSCs into the steroid-impaired femoral head. Gene expression and the pathological alternation of the tissues were analyzed by qRT-PCR and hematoxylin and eosin staining, respectively. Tartrate-resistant acid phosphatase staining was applied to detect osteoclastogenesis. Enzyme linked immunosorbent assay (ELISA) and Western blot were performed to evaluate the protein expression in the sera and tissues, respectively.&#x0D; Results: ABMSCs attenuated steroid-induced ONFH and ameliorated the serum concentration of osteogenesis-associated proteins in the ONFH mice. Mechanistically, ABMSCs inhibited osteoclast differentiation by inactivating the RANKL/RANK/OPG signaling pathway. BMP-2 overexpression enhanced ABMSCs to alleviate ONFH.&#x0D; Conclusions: ABMSCs and BMP-2 Transgenic ABMSCs attenuate ONFH by promoting osteoblastogenesis and inhibiting osteoclastogenesis via inactivating the RANKL/RANK/OPG signaling pathway.

The Emerging Biological Functions of Exosomes from Dental Tissue-Derived Mesenchymal Stem Cells.

Exosomes are one kind of small-cell extracellular membranous vesicles that can regulate intercellular communication and give rise to mediating the biological behaviors of cells, involving in tissue formation, repair, the modulation of inflammation, and nerve regeneration. The abundant kinds of cells can secret exosomes, among them, mesenchymal stem cells (MSCs) are very perfect cells for mass production of exosomes. Dental tissue-derived mesenchymal stem cells (DT-MSCs), including dental pulp stem cells, stem cells from exfoliated deciduous teeth, stem cells from apical papilla, stem cells from human periodontal ligament (PDLSCs), gingiva-derived mesenchymal stem cells, dental follicle stem cells, tooth germ stem cells, and alveolar bone-derived mesenchymal stem cells, are now known as a potent tool in the area of cell regeneration and therapy, more importantly, DT-MSCs can also release numerous types of exosomes, participating in the biological functions of cells. Hence, we briefly depict the characteristics of exosomes, give a detailed description of the biological functions and clinical application in some respects of exosomes from DT-MSCs through systematically reviewing the latest evidence, and provide a rationale for their use as tools for potential application in tissue engineering.

Is mandible derived mesenchymal stromal cells superior in proliferation and regeneration to long bone-derived mesenchymal stromal cells?

Mesenchymal stromal cells (MSCs) are cells with the characteristic ability of self-renewal along with the ability to exhibit multilineage differentiation. Bone marrow (BM) is the first tissue in which MSCs were identified and BM-MSCs are most commonly used among various MSCs in clinical settings. MSCs can stimulate and promote osseous regeneration. Due to the difference in the development of long bones and craniofacial bones, the mandibular-derived MSCs (M-MSCs) have distinct differentiation characteristics as compared to that of long bones. Both mandibular and long bone-derived MSCs are positive for MSC-associated markers such as CD-73, -105, and -106, stage-specific embryonic antigen 4 and Octamer-4, and negative for hematopoietic markers such as CD-14, -34, and -45. As the M-MSCs are derived from neural crest cells, they have embryogenic cells which promote bone repair and high osteogenic potential. In vitro and in vivo animal-based studies demonstrate a higher rate of proliferation and high osteogenic potential for M-MSCs as compared to long-bones MSCs, but in vivo studies in human subjects are lacking. The BM-MSCs have their advantages and limitations. M-MSCs may be utilized as an alternative source of MSCs which can be utilized for tissue engineering and promoting the regeneration of bone. M-MSCs may have potential advantages in the repair of craniofacial or orofacial defects. Considering the utility of M-MSCs in the field of orthopaedics, we have discussed various unresolved questions, which need to be explored for their better utility in clinical practice.

Bioactive Glass Inhibits Tumor Development from Giant Cell Tumor of Bone-Derived Neoplastic Stromal Cells in a Chicken Chorioallantoic Membrane Assay.

Tumor recurrence is a major problem during the treatment of giant cell tumors of bone (GCTB). We recently identified tumor cell-specific cytotoxic effects of bioactive glasses (BGs) toward neoplastic stromal cells derived from GCTB tissue (GCTSCs) in vitro. Since these data indicated a promising role of BGs in the adjuvant treatment of GCTBs, we aimed to investigate the transferability of the in vitro data into the more complex in vivo situation in the current study. We first analyzed the cytotoxicity of three different BGs in vitro by WST-1 assay after co-cultivation with primary GCTSC cell lines. The effects of BGs on tumor engraftment and growth were analyzed by chicken chorioallantoic membrane (CAM) assays and subsequent quantification of tumor take rates and tumor volumes. In vitro, all tested BGs displayed a cytotoxic effect on GCTSCs that was dependent on BG composition, concentration, and particle size. Comparable effects could be observed within the in vivo environment resulting in reduced tumor take rates and tumor volumes in BG-treated samples. These data indicate a possible clinical application of BGs in the context of GCTB therapy, mediating a reduction of recurrence rates with the simultaneous promotion of bone regeneration.

Impact of intravenously administered cranial bone-derived mesenchymal stem cells on functional recovery in experimental spinal cord injury

Impairments of the central nervous system, such as stroke, brain trauma, and spinal cord injury (SCI), cannot be reversed using current treatment options. Herein, we compared the characteristics of rat cranial bone-derived mesenchymal stem cells (rcMSCs) and rat bone marrow-derived mesenchymal stem cells (rbMSCs). We also investigated the therapeutic effects of intravenously administered rcMSCs and rbMSCs in a rat model of cervical SCI (cSCI) and elucidated its undrelying mechanism. Comprehensive comparative bioinformatics analysis of rcMSCs and rbMSCs RNA sequencing revealed that genes associated with leukocyte transendothelial migration and chemokine signaling were significantly downregulated in rcMSCs. Rats were divided into three groups that received intrtravenous administration of rcMSC, rbMSC, or phosphate-buffered saline (control) 24 h after cSCI. The rcMSC-treated group showed improved functional recovery over the rbMSC-treated and control groups, and reduced lesion volume compared with the control group. The mRNA expression of nitric oxide synthase 2 at the spinal cord lesion site was significantly higher in the rcMSC-treated group than in the control and rbMSCs-treated groups, whereas that of transforming growth factor-β was significantly higher in the rcMSC-treated group compared to that in the control group. The transcriptome data indicated that rcMSCs and rbMSCs differentially affect inflammation. The intravenous administration of rcMSCs contributed to functional recovery and lesion reduction in cSCI. The rcMSCs have the potential to induce an anti-inflammatory environment in cSCI.

Nanosilica-Anchored Polycaprolactone/Chitosan Nanofibrous Bioscaffold to Boost Osteogenesis for Bone Tissue Engineering.

The strategy of incorporating bioactive inorganic nanomaterials without side effects as osteoinductive supplements is promising for bone regeneration. In this work, a novel biomass nanofibrous scaffold synthesized by electrospinning silica (SiO2) nanoparticles into polycaprolactone/chitosan (PCL/CS) nanofibers was reported for bone tissue engineering. The nanosilica-anchored PCL/CS nanofibrous bioscaffold (PCL/CS/SiO2) exhibited an interlinked continuous fibers framework with SiO2 nanoparticles embedded in the fibers. Compact bone-derived cells (CBDCs), the stem cells derived from the bone cortex of the mouse, were seeded to the nanofibrous bioscaffolds. Scanning electron microscopy and cell counting were used to observe the cell adhesion. The Counting Kit-8 (CCK-8) assay was used. Alkaline phosphatase (ALP), Alizarin red staining, real-time Polymerase Chain Reaction and Western blot tests were performed to confirm the osteogenesis of the CBDCs on the bioscaffolds. The research results demonstrated that the mechanical property of the PCL together with the antibacterial and hydrophilic properties of the CS are conducive to promoting cell adhesion, growth, migration, proliferation and differentiation. SiO2 nanoparticles, serving as bone induction factors, effectively promote the osteoblast differentiation and bone regeneration. This novel SiO2-anchored nanofibrous bioscaffold with superior bone induction activity provides a better way for bone tissue regeneration.

TCDD alters essential transcriptional regulators of osteogenic differentiation in multipotent mesenchymal stem cells.

Differentiation of multipotent mesenchymal stem cells (MSCs) into bone-forming osteoblasts requires strict coordination of transcriptional pathways. Aryl hydrocarbon receptor ligands, such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), have been shown to alter osteoblast differentiation in vitro and bone formation in multiple developmental in vivo models. The goal of the present study was to establish a global transcriptomic landscape during early, intermediate, and apical stages of osteogenic differentiation in vitro in response to TCDD exposure. Human bone-derived mesenchymal stem cells (hBMSCs) were cultured in growth media (GM), osteogenic differentiation media (ODM), or ODM containing 10 nM TCDD (ODM + TCDD), thus enabling a comparison of the transcriptomic profiles of undifferentiated, differentiated, and differentiated-TCDD-exposed hBMSCs, respectively. In this test system, exposure to TCDD attenuated the differentiation of hBMSCs into osteoblasts as evidenced by reduced alkaline phosphatase activity and mineralization. At various timepoints, we observed altered expression of genes that play a role in the Wnt, fibroblast growth factor, bone morphogenetic protein/transforming growth factor beta developmental pathways, as well as pathways related to extracellular matrix organization and deposition. Reconstruction of gene regulatory networks with the interactive dynamic regulatory event miner (iDREM) analysis revealed modulation of transcription factors (TFs) including POLR3G, NR4A1, RDBP, GTF2B, POU2F2, and ZEB1, which may putatively influence osteoblast differentiation and the requisite deposition and mineralization of bone extracellular matrix. We demonstrate that the combination of RNA-Seq data in conjunction with the iDREM regulatory model captures the transcriptional dynamics underlying MSC differentiation under different conditions in vitro. Model predictions are consistent with existing knowledge and provide a new tool to identify novel pathways and TFs that may facilitate a better understanding of the osteoblast differentiation process, perturbation by exogenous agents, and potential intervention strategies targeting those specific pathways.

Hypoxia promotes osteogenesis by facilitating acetyl-CoA-mediated mitochondrial-nuclear communication.

Bone-derived mesenchymal stem cells (MSCs) reside in a hypoxic niche that maintains their differentiation potential. While hypoxia (low oxygen concentration) was reported to critically support stem cell function and osteogenesis, the molecular events triggering changes in stem cell fate decisions in response to normoxia (high oxygen concentration) remain elusive. Here, we study the impact of normoxia on mitochondrial-nuclear communication during stem cell differentiation. We show that normoxia-cultured murine MSCs undergo profound transcriptional alterations which cause irreversible osteogenesis defects. Mechanistically, high oxygen promotes chromatin compaction and histone hypo-acetylation, particularly on promoters and enhancers of osteogenic genes. Although normoxia induces metabolic rewiring resulting in elevated acetyl-CoA levels, histone hypo-acetylation occurs due to the trapping of acetyl-CoA inside mitochondria owing to decreased citrate carrier (CiC) activity. Restoring the cytosolic acetyl-CoA pool remodels the chromatin landscape and rescues the osteogenic defects. Collectively, our results demonstrate that the metabolism-chromatin-osteogenesis axis is perturbed upon exposure to high oxygen levels and identifies CiC as a novel, oxygen-sensitive regulator of the MSC function.

Hydroxytyrosol-rich extract from olive juice as an additive in gilthead sea bream juveniles fed a high-fat diet: Regulation of somatic growth.

The dietary inclusion of plant-based products in fish feeds formulation is required for the sustainable development of aquaculture. Moreover, considering functional diets, hydroxytyrosol, one of the major phenolic compounds found in olives (Olea europaea), has been identified as a potential candidate to be used in the aquafeeds industry due to its health promoting abilities. The aim of this study was to evaluate the effects of the inclusion of an olive juice extract rich in hydroxytyrosol as an additive (0.52 g HT/kg feed) in a high-fat (24% lipids) diet in gilthead sea bream (Sparus aurata) juveniles. Moreover, the experimental diets, with or without the extract, were administered daily at a standard (3% of total biomass in the tank) or restricted ration (40% reduction) for 8–9 weeks. Growth and biometric parameters, insulin-like growth factor 1 (IGF-1) plasma levels and growth hormone/IGF axis-, myogenic- and osteogenic-related genes expression in liver, white muscle and/or bone were analyzed. Moreover, in vitro cultures of vertebra bone-derived cells from fish fed the diets at a standard ration were performed at weeks 3 and 9 to explore the effects of hydroxytyrosol on osteoblasts development. Although neither body weight or any other biometric parameter were affected by diet composition after 4 or 8 weeks, the addition of the hydroxytyrosol-rich extract to the diet increased IGF-1 plasma levels, regardless of the ration regime, suggesting an anabolic condition. In muscle, the higher mRNA levels of the binding protein igfbp-5b and the myoblast fusion marker dock5 in fish fed with the hydroxytyrosol-rich diet suggested that this compound may have a role in muscle, inducing development and a better muscular condition. Furthermore in bone, increased osteogenic potential while delayed matrix mineralization after addition to the diet of the olive juice extract was supported by the upregulated expression of igf-1 and bmp4 and reduced transcript levels of osteopontin. Overall, this study provides new insights into the beneficial use of hydroxytyrosol as a dietary additive in gilthead sea bream functional diets to improve muscle-skeletal condition and, the aquaculture industry.