MEG3 shuttled by exosomes released from human bone marrow mesenchymal stem cells promotes TP53 stability to regulate MCM5 transcription in keloid fibroblasts

BACKGROUND

Despite the interest in mesenchymal stem cells (MSC), their potential to treat abnormal scarring, especially keloids, is yet to be described. The present study aimed to investigate the therapeutic potential of exosomes derived from human bone marrow MSCs (hBMSC-Exos) in alleviating keloid formation.

METHODS

Exosomes were isolated from hBMSC, and keloid fibroblasts (KFs) were treated with hBMSC-Exos. Cell counting kit-8, wound healing, transwell invasion, immunofluorescence, and western blot assays were conducted to study the malignant phenotype of KFs. Mice were induced with keloids and treated with hBMSC-Exos. The effect of hBMSC-Exos on keloid formation in vivo was evaluated by hematoxylin and eosin staining, Masson staining, immunohistochemistry, and western blotting. The GSE182192 dataset was screened for differentially expressed long non-coding RNA during keloid formation. Next, maternally expressed gene 3 (MEG3) was knocked down in hBMSC to obtain hBMSC-Exossh-MEG3. The molecular mechanism of MEG3 was investigated by bioinformatic screening, and the relationship between MEG3 and TP53 or MCM5 was verified.

RESULTS

hBMSC-Exos inhibited the malignant proliferation, migration, and invasion of KFs at same time as promoting their apoptosis, Moreover, hBMSC-Exos reduced the expression of fibrosis- and collagen-related proteins in the cells and the formation of keloids caused by KFs. The reduction in MEG3 enrichment in hBMSC-Exos weakened the inhibitory effect of hBMSC-Exos on KF activity. hBMSC-Exos delivered MEG3 to promote MCM5 transcription by TP53 in KFs. Overexpression of MCM5 in KFs reversed the effects of hBMSC-Exossh-MEG3, leading to reduced KF activity.

CONCLUSIONS

hBMSC-Exos delivered MEG3 to promote the protein stability of TP53, thereby activating MCM5 and promoting KF activity.

Bioactive materials from berberine-treated human bone marrow mesenchymal stem cells promote alveolar bone regeneration by regulating macrophage polarization

Alveolar bone regeneration has been strongly linked to macrophage polarization. M1 macrophages aggravate alveolar bone loss, whereas M2 macrophages reverse this process. Berberine (BBR), a natural alkaloid isolated and refined from Chinese medicinal plants, has shown therapeutic effects in treating metabolic disorders. In this study, we first discovered that culture supernatant (CS) collected from BBR-treated human bone marrow mesenchymal stem cells (HBMSCs) ameliorated periodontal alveolar bone loss. CS from the BBR-treated HBMSCs contained bioactive materials that suppressed the M1 polarization and induced the M2 polarization of macrophages in vivo and in vitro. To clarify the underlying mechanism, the bioactive materials were applied to different animal models. We discovered macrophage colony-stimulating factor (M-CSF), which regulates macrophage polarization and promotes bone formation, a key macromolecule in the CS. Injection of pure M-CSF attenuated experimental periodontal alveolar bone loss in rats. Colony-stimulating factor 1 receptor (CSF1R) inhibitor or anti-human M-CSF (M-CSF neutralizing antibody, Nab) abolished the therapeutic effects of the CS of BBR-treated HBMSCs. Moreover, AKT phosphorylation in macrophages was activated by the CS, and the AKT activator reversed the negative effect of the CSF1R inhibitor or Nab. These results suggest that the CS of BBR-treated HBMSCs modulates macrophage polarization via the M-CSF/AKT axis. Further studies also showed that CS of BBR-treated HBMSCs accelerated bone formation and M2 polarization in rat teeth extraction sockets. Overall, our findings established an essential role of BBR-treated HBMSCs CS and this might be the first report to show that the products of BBR-treated HBMSCs have active effects on alveolar bone regeneration.

BM-MSC-Loaded Graphene-Collagen Cryogels Ameliorate Neuroinflammation in a Rat Spinal Cord Injury Model

A major obstacle to axonal regeneration following spinal cord injury (SCI) is neuroinflammation mediated by astrocytes and microglial cells. We previously demonstrated that graphene-based collagen hydrogels alone can decrease neuroinflammation in SCI. Their regenerative potential, however, is poorly understood and incomplete. Furthermore, stem cells have demonstrated both neuroprotective and regenerative properties in spinal cord regeneration, although there are constraints connected with the application of stem cell-based therapy. In this study, we have analyzed the regeneration capability of human bone marrow mesenchymal stem cell (BM-MSC)-loaded graphene-cross-linked collagen cryogels (Gr-Col) in a thoracic (T10-T11) hemisection model of SCI. Our study found that BM-MSC-loaded Gr-Col improves axonal regeneration, reduces neuroinflammation by decreasing astrocyte reactivity, and promotes M2 macrophage polarization. BM-MSC-loaded-Gr-Col demonstrated enhanced regenerative potential compared to Gr-Col and the injury group control. Next-generation sequencing (NGS) analysis revealed that BM-MSC-loaded-Gr-Col modulates the JAK2-STAT3 pathway, thus decreasing the reactive and scar-forming astrocyte phenotype. The decrease in neuroinflammation in the BM-MSC-loaded-Gr-Col group is attributed to the modulation of Notch/Rock and STAT5a/b and STAT6 signaling. Overall, Gene Set Enrichment Analysis suggests the promising role of BM-MSC-loaded-Gr-Col in promoting axonal regeneration after SCI by modulating molecular pathways such as the PI3/Akt pathway, focal adhesion kinase, and various inflammatory pathways.

Impact of Anti-Mycotic Drugs on the Osteogenic Response of Bone Marrow Mesenchymal Stem Cells In Vitro

The treatment of fungal bone infections and infected non-unions is a huge challenge in modern trauma and orthopedics, which normally contain the local and systemic administration of anti-fungal drugs. Although frequently used, little is known about the impact of systemic and locally administered fungicides on the osteogenic regenerative capabilities of infected bone tissue, especially upon the osteogenesis of human bone marrow mesenchymal stem cells (BM-hMSCs). This study evaluates the effects of the three most common fungicides for the systemic treatment of bone infections, Voriconazole (VOR), liposomal Amphotericin B (LAMB), and Fluconazole (FLU), as well as the effects of VOR and LAMB-loaded Polymethylmethacrylate (PMMA) cement chips in different concentrations upon the osteogenic response of BM-hMSCs in vitro. Within this study, we compared the ability of BM-hMSC to differentiate into osteoblast-like cells and synthesize hydroxyapatite as assessed by radioactive 99mTechnetium-Hydroxydiphosphonate (99mTc-HDP) labeling, cell proliferation, and analyses of supernatants upon various osteogenic parameters. Our results revealed that VOR added to the cell culture medium affects the osteogenic potential of BM-hMSC negatively, while there were no detectable effects of LAMB and FLU. Moreover, we showed dose-dependent negative effects of high- and extended-dose fungicide-loaded PMMA cement due to cytotoxicity, with a higher cytotoxic potential of VOR than LAMB, while low-dose fungicide-loaded PMMA had no significant effect on the osteogenic potential of BM-hMSC in vitro.

Therapeutic Effect of Human Bone Marrow- and Adipose-Derived Stem Cells on Intervertebral Disc Degeneration: A Comparative Study on Rats

BACKGROUND

Intervertebral disc degeneration (IVD) is a pain-inflicting disorder, posing a serious threat to the elderly, and new therapies are urgently needed. In this study, we examined the potential therapeutic effect of mesenchymal stem cells (MSCs) transplantation on IVD.

METHODS

Both human adipose-derived stem cells (hADSCs) and human bone marrow mesenchymal stem cells (hBMSCs) provided by a volunteer were non-contact co-cultured with the human nucleus pulposus cells (hNPCs) to determine the efficacy of hNPCs-oriented differentiation. Flow cytometry was used to characterize the purity of hADSCs/hBMSCs. We determined the expression of surface antigen molecules, such as CD73, CD105, CD90, CD31, HLA-DR, CD34 and CD45, using flow cytometry. Osteogenic and lipogenic differentiations demonstrated by the cells were identified with Alizarin red and Oil red O staining, respectively, and changes in type II collagen and proteoglycan levels were detected by immunofluorescence. Myeloid cell-related mRNA and protein expression levels were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot, respectively. The therapeutic effect of hADSCs and hBMSCs on IVD was evaluated in experimental rats, in which degeneration was induced by needling the annulus fibrosus of the caudal intervertebral disc.

RESULTS

As evidenced by the presence of hNPCs-like morphology, both hBMSCs and hADSC could effectively differentiate into hNPCs. Using flow cytometry assays, we found high expression of type II collagen (COL2) and aggrecan (ACAN) protein in the hNPCs-like tissue. Treatment with hADSCs and hBMSCs attenuated IVD progression in the rats, and most importantly, there was no significant difference between the therapeutic effects of both types of cells on IVD, on the basis of the COL2 and SRY-Box Transcription Factor 9 (SOX9) protein expression and the histological results. Findings from the animal studies also suggested that both hADSCs and hBMSCs transplantation could be applied in IVD treatment.

CONCLUSIONS

In summary, both hADSCs and hBMSCs can attenuate the progression of IVD by delaying, rather than completely reversing the deterioration of disc degeneration, and there is no significant difference between hADSCs and hBMSCs on the therapeutic effects.

[Corrigendum] Icaritin promotes the osteogenesis of bone marrow mesenchymal stem cells via the regulation of sclerostin expression

Following the publication of the above article, the authors have contacted the Editorial Office to explain that they had assembled the cellular morphological images in Fig. 1A on p. 819 incorrectly; essentially, the cell morphology of 2 passages of hBMSCs (centre panel) should have been shown as the data panel for 3 passages of hBMSCs (right-hand panel), and likewise, the cell morphology of 3 passages of hBMSCs should have been shown as the data panel for 2 passages of hBMSCs. The revised version of Fig. 1 is shown below. The authors confirm that the errors associated with this figure did not have any significant impact on either the results or the conclusions reported in this study, and are grateful to the Editor of International Journal of Molecular Medicine for allowing them the opportunity to publish this Corrigendum. Furthermore, they apologize to the readership of the Journal for any inconvenience caused. [International Journal of Molecular Medicine 45: 816-824, 2020; DOI: 10.3892/ijmm.2020.4470].

CCK regulates osteogenic differentiation through TNFα/NF-κB in peri-implantitis

OBJECTIVE

Peri-implantitis is characterized by peri-implant mucositis and alveolar bone resorption. This study investigated cholecystokinin (CCK) expression and the mechanism underlying its involvement in peri-implantitis.

METHODS

mRNA sequencing was performed using the Gene Expression Omnibus database GSE106090. Human bone marrow mesenchymal stem cells (hBMSCs) were pretreated with various concentrations of CCK (0, 10, 30, or 100 nM) for 1 hour before induction in osteogenic differentiation medium for 2 weeks. Alkaline phosphatase (ALP) activity was determined, and the cells were stained with alizarin red. The expression levels of TNFα and the osteogenic markers ALP, RUNX2, and OCN were measured using quantitative real-time PCR. TNFα, phosphorylated P65, and total P65 levels were determined by western blot.

RESULTS

Compared with healthy individuals, 262 and 215 genes were up- and down-regulated, respectively, in the periodontal tissues of patients with peri-implantitis. CCK expression was significantly upregulated in patients with peri-implantitis. CCK reduced ALP activity, osteogenic differentiation, and levels of the osteogenic markers ALP, RUNX2, and OCN. Moreover, CCK promoted levels of TNFα and phosphorylated P65, which is a marker of activation for the NF-κB inflammatory pathway.

CONCLUSIONS

CCK regulates osteogenic differentiation through the TNFα/NF-κB axis in peri-implantitis.

[Protective effects of estrogen modified hBMSC on HG-induced injury of vascular endothelial cells]

Objective: To investigate the protective effects and potential mechanisms of estrogen modified human bone marrow mesenchymal stem cells (hBMSC) on high glucose (HG)-induced injury of vascular endothelial cells. Methods: hBMSCs were cultured under 30 mmol/l glucose to establish a high glucose model (HG), and then were divided into four groups as following: HG group (HG control, without any treatment), HG+E2 group (cells were treated with 20 μmol/L estrogen), HG+E2+ Triciribine group (cells were pretreated with 5 μmol/L protein kinase B (PKB/Akt) inhibitor for 45 min, and then modified by 20 μmol/L estrogen), and NG group (cells were cultured under normal conditions). After 12 h treatment, the cell viability of hBMSC was detected by CCK8 assay, and the contents of NO, VEGF and IL8 in the supernatant of cultured medium in each group were detected by nitrate reductase and ELISA assay (n=6). After 48 h, the expression levels of endothelial nitric oxide synthase (eNOS) and phosphorylated eNOS (p-eNOS) were detected by Western blot (n=3). In addition, the cell supernatant of each group was further extracted as conditioned medium to culture HUVECs, and the cells were subsequently divided into HG-CM group (HUVECs were treated with HG group's conditioned medium), HG+E2-CM group (HUVECs were treated with HG+E2 group's conditioned medium), HG+E2+Triciribine-CM group (HUVECs were treated with HG+E2+ Triciribine group's conditioned medium) and HG-H group (HUVEC were cultured under HG condition, which were treated with final concentration 30 mmol/l glucose). The cell viability of HUVECs in each group was detected by CCK8 assay after 12 h cultured (n=6). After 24 h treatment, the apoptosis rate of HUVECs in each group was detected by flow cytometry (n=3). Furthermore, the migration rate of HUVECs in each group was observed by wound healing assay after 48 h cultured (n=3). Results: Compared with NG group, the cell viability and eNOS protein phosphorylation level of hBMSC in HG group and the contents of NO, VEGF and IL-8 in the supernatant of cultured medium were decreased (P<0.05). Compared with HG group, the cell viability and eNOS protein phosphorylation level in HG+E2 group and the contents of NO, VEGF and IL-8 in cultured medium supernatant were increased significantly (P<0.05), whereas pre-treatment of hBMSC cells with a Akt inhibitor Triciribine, the above indexes showed reverse changes (P<0.05). Furthermore, compared with HG-CM group, the cell viability and migration ability (P<0.05) of HUVECs in HG+E2-CM group were increased significantly (P<0.05), and the proportion of apoptosis was decreased (P<0.05). While compared with HG+E2-CM group, the cell viability and migration ability of HUVECs in HG+E2+Triciribine-CM group were decreased (P<0.05), and the proportion of apoptosis was increased (P<0.05). Conclusion: Estrogen may promote the secretion of NO, VEGF and IL-8 by activating the Akt/eNOS signaling pathway of hBMSC cells, increase the cell viability and migration ability of HUVECs and inhibit the occurrence of apoptosis, play a protective role against the injury of HUVECs induced by HG condition.

E3 ligase HUWE1 promotes PDGF D-mediated osteoblastic differentiation of mesenchymal stem cells by effecting polyubiquitination of β-PDGFR

Mesenchymal stem cells (MSCs) are adult stem cell populations and exhibit great potential in regenerative medicine and oncology. Platelet-derived growth factors (PDGFs) are well known to regulate MSC biology through their chemotactic and mitogenic properties. However, their direct roles in the regulation of MSC lineage commitment are unclear. Here, we show that PDGF D promotes the differentiation of human bone marrow mesenchymal stem cells (hBMSCs) into osteoblasts and inhibits hBMSC differentiation into adipocytes. We demonstrate that PDGF D-induced β-actin expression and polymerization are essential for mediating this differential regulation of osteoblastogenesis and adipogenesis. Interestingly, we found that PDGF D induces massive upward molecular weight shifts of its cognate receptor, PDGF receptor beta (β-PDGFR) in hBMSCs, which was not observed in fibroblasts. Proteomic analysis indicated that the E3 ubiquitin ligase HECT, UBA, and WWE domain–containing protein 1 (HUWE1) associates with the PDGF D-activated β-PDGFR signaling complex in hBMSCs, resulting in β-PDGFR polyubiquitination. In contrast to the well-known role of ubiquitin in protein degradation, we provide evidence that HUWE1-mediated β-PDGFR polyubiquitination delays β-PDGFR internalization and degradation, thereby prolonging AKT signaling. Finally, we demonstrate that HUWE1-regulated β-PDGFR signaling is essential for osteoblastic differentiation of hBMSCs, while being dispensable for PDGF D-induced hBMSC migration and proliferation as well as PDGF D-mediated inhibition of hBMSC differentiation into adipocytes. Taken together, our findings provide novel insights into the molecular mechanism by which PDGF D regulates the commitment of hBMSCs into the osteoblastic lineage.

Strategy of Stem Cell Transplantation for Bone Regeneration with Functionalized Biomaterials and Vascularized Tissues in Immunocompetent Mice

The use of human bone marrow mesenchymal stem cells (hBMSCs) to regenerate and repair bone tissue defects is a complex research field of bone tissue engineering; nevertheless, it is a hot topic. One of the biggest problems is the limited survival and osteogenic capacity of the transplanted cells within the host tissue. Even for hBMSCs with their low immunogenicity, the body will still cause a local immune-inflammatory response directed against the allogeneic cells and thereby reduce the activity of the transplanted cells. Even in the case of successful transplantation, the lack of vascularization at the transplantation site makes it difficult for the transplanted cells to exchange nutrients and metabolic wastes that ultimately affects bone regeneration. In this study, we covalently modified alginate with RGD and QK peptides that were injected subcutaneously into immunocompetent mice. Histological analysis, as well as ELISA techniques, proved that this method is able to provide bioactive stem cell transplant beds containing functionalized biomaterials and vascularized surrounding tissues. Inflammation-related factors, such as IL-2, IL-6, TNF-α, and IFN-γ, around the cell graft beds decreased with time and were lowest at the second week. Then, the hBMSCs were injected into the cell transplantation beds intended to form vascularized bonelike tissues that were evaluated by micro-computed tomography (Micro CT), histological, and immunohistochemical analyses. The results showed that the expression of osteogenesis-related proteins RUNX2, COL1A1, and OPN, as well as the expression of angiogenic factor vWF and cartilage-related protein COL2A1 were significantly upregulated in the hBMSC-derived osteogenic tissue. These results suggest that the stem cell transplantation strategy by constructing bioactive cell transplant beds is effective to enhance the bone regeneration capacity of hBMSCs and holds great potential in bone tissue engineering.

Effect of Cell Therapy and Exercise Training in a Stroke Model, Considering the Cell Track by Molecular Image and Behavioral Analysis

The goal of this study is to see how combining physical activity with cell treatment impacts functional recovery in a stroke model. Molecular imaging and multimodal nanoparticles assisted in cell tracking and longitudinal monitoring (MNP). The viability of mesenchymal stem cell (MSC) was determined using a 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay and bioluminescent image (BLI) after lentiviral transduction and MNP labeling. At random, the animals were divided into 5 groups (control-G1, and experimental G2-G5). The photothrombotic stroke induction was confirmed by local blood perfusion reduction and Triphenyltetrazolium chloride (TTC), and MSC in the G3 and G5 groups were implanted after 24 h, with BLI and near-infrared fluorescence image (NIRF) tracking these cells at 28 h, 2, 7, 14, and 28 days. During a 28-day period, the G5 also conducted physical training, whereas the G4 simply did the training. At 0, 7, 14, and 28 days, the animals were functionally tested using a cylinder test and a spontaneous motor activity test. MNP internalization in MSC was confirmed using brightfield and fluorescence microscopy. In relation to G1 group, only 3% of cell viability reduced. The G2–G5 groups showed more than 69% of blood perfusion reduction. The G5 group performed better over time, with a progressive recovery of symmetry and an increase of fast vertical movements. Up to 7 days, BLI and NIRF followed MSC at the damaged site, demonstrating a signal rise that could be connected to cell proliferation at the injury site during the acute phase of stroke. Local MSC therapy mixed with physical activity resulted in better results in alleviating motor dysfunction, particularly during the acute period. When it comes to neurorehabilitation, this alternative therapy could be a suitable fit.

Barbaloin Promotes Osteogenic Differentiation of Human Bone Marrow Mesenchymal Stem Cells: Involvement of Wnt/β-catenin Signaling Pathway

BACKGROUND

Barbaloin, found in Aloe vera, exerts broad pharmacological activities, including antioxidant, anti-inflammatory, and anti-cancer. This study aims to investigate the effects of barbaloin on the osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs).

METHODS

Osteogenic induction of hBMSCs was performed in the presence or absence of barbaloin. Cell viability was determined by using the CCK-8 assay. The characteristic of hBMSCs was identified by using flow cytometry. Intracellular alkaline phosphatase (ALP) staining was performed to evaluate the ALP activity in hBMSCs. Alizarin Red S staining was performed to evaluate the matrix mineralization. The mRNA and protein levels of target genes were determined using qRT-PCR and western blotting, respectively.

RESULTS

Treatment with barbaloin (10 and 20 μg/mL) significantly increased cell viability of hBMSCs after 72 hours. In addition, treatment with barbaloin increased the mRNA expression levels of ALP and its activities. Treatment with barbaloin also increased matrix mineralization and the mRNA and protein levels of late-differentiated osteoblast marker genes BMP2, RUNX2, and SP7 in hBMSCs. The underlying mechanisms revealed that barbaloin increased the protein expressions of Wnt/β-catenin pathway-related biomarkers.

CONCLUSION

Barbaloin promotes osteogenic differentiation of hBMSCs by the regulation of the Wnt/β-catenin signaling pathway.

Bone marrow mesenchymal stem cell-derived exosomal MiR-338-3p represses progression of hepatocellular carcinoma by targeting ETS1

The present study aims to explore the function of human bone marrow mesenchymal stem cell (BMSC)-derived exosomal micro ribonucleic acid (miR)-338-3p in hepatocellular carcinoma (HCC) and further investigate its effect on HCC cell functions. Firstly, BMSCs were co-cultured with HCC cells, and BMSC-derived exosomes were identified. Next, Transwell assay and methyl thiazolyl tetrazolium (MTT) experiments were carried out to detect the effects of miR-338-3p and E26 transformation specific-1 (ETS1) on the viability, invasion, migration, and apoptosis of HCC cells through the exosomes derived from BMSCs. Furthermore, the targeting relationship between miR-338-3p and EST1 was verified via bioinformatics study and dual-luciferase reporter gene analysis. Additionally, Western blotting (WB) was carried out to measure the expression levels of EST1 and other proteins in HCC cells. It was found that BMSCs inhibited HCC cell proliferation, invasion and migration, and induced cell apoptosis, while the inhibitors of exosomes played the opposite roles. In addition, the up-regulation of exosomal miR-338-3p or the silencing of EST1 restrained HCC cell proliferation, invasion and migration, and induced cell apoptosis. In conclusion, BMSC-derived exosomal miR-338-3p delays the development of HCC by down-regulating EST1, providing a new promising treatment target for HCC.

Effect of TO901317 on GF to promote the differentiation of human bone marrow mesenchymal stem cells into dopamine neurons on Parkinson's disease

Background:

Human bone marrow mesenchymal stem cells (hBMSCs) could differentiate into dopamine-producing cells and ameliorate behavioral deficits in Parkinson’s disease (PD) models. Liver X receptors (LXRs) are involved in the maintenance of the normal function of central nervous system myelin. Therefore, the previous work of our team has found the induction of cocktail-induced to dopaminergic (DA) phenotypes from adult rat BMSCs by using sonic hedgehog (SHH), fibroblast growth factor 8 (FGF8), basic fibroblast growth factor (bFGF), and TO901317 (an agonist of LXRs) with 87.42% of efficiency in a 6-day induction period. But we did not verify whether the induced cells had the corresponding neural function.

Methods:

Expressions of LXRα, LXRβ, and tyrosine hydroxylase (TH) were detected by immunofluorescence and western blot. Adenosine triphosphate-binding cassette transporter A1 (ABCA1) was detected by quantitative real-time PCR. The induced cells were transplanted into PD rats to study whether the induced cells are working.

Results:

The induced cells can release the dopamine transmitter; the maximum induction efficiency of differentiation of hBMSCs into DA neurons was 91.67% under conditions of combined use with TO901317 and growth factors (GF). When the induced-cells were transplanted into PD rats, the expression of TH in the striatum increased significantly, and the behavior of PD rats induced by apomorphine was significantly improved.

Conclusion:

The induced cells have the function of DA neurons and have the potential to treat PD. TO901317 promoted differentiation of hBMSCs into DA neurons, which may be related to activation of the LXR-ABCA1 signaling pathway.

Chondrogenic Commitment of Human Bone Marrow Mesenchymal Stem Cells in a Perfused Collagen Hydrogel Functionalized with hTGF-β1-Releasing PLGA Microcarrier

Tissue engineering strategies can be relevant for cartilage repair and regeneration. A collagen matrix was functionalized with the addition of poly-lactic-co-glycolic acid microcarriers (PLGA-MCs) carrying a human Transforming Growth Factor β1 (hTFG-β1) payload, to provide a 3D biomimetic environment with the capacity to direct stem cell commitment towards a chondrogenic phenotype. PLGA-MCs (mean size 3 ± 0.9 μm) were prepared via supercritical emulsion extraction technology and tailored to sustain delivery of payload into the collagen hydrogel for 21 days. PLGA-MCs were coseeded with human Bone Marrow Mesenchymal Stem Cells (hBM-MSCs) in the collagen matrix. Chondrogenic induction was suggested when dynamic perfusion was applied as indicated by transcriptional upregulation of COL2A1 gene (5-fold; p < 0.01) and downregulation of COL1A1 (0.07-fold; p < 0.05) and COL3A1 (0.11-fold; p < 0.05) genes, at day 16, as monitored by qRT-PCR. Histological and quantitative-immunofluorescence (qIF) analysis confirmed cell activity by remodeling the synthetic extracellular matrix when cultured in perfused conditions. Static constructs lacked evidence of chondrogenic specific gene overexpression, which was probably due to a reduced mass exchange, as determined by 3D system Finite Element Modelling (FEM) analysis. Proinflammatory (IL-6, TNF, IL-12A, IL-1β) and anti-inflammatory (IL-10, TGF-β1) cytokine gene expression by hBM-MSC was observed only in dynamic culture (TNF and IL-1β 10-fold, p < 0.001; TGF-β1 4-fold, p < 0.01 at Day 16) confirming the cells’ immunomodulatory activity mainly in relation to their commitment and not due to the synthetic environment. This study supports the use of 3D hydrogel scaffolds, equipped for growth factor controlled delivery, as tissue engineered models for the study of in vitro chondrogenic differentiation and opens clinical perspectives for injectable collagen-based advanced therapy systems.

Human bone marrow mesenchymal stem cell-derived extracellular vesicles impede the progression of cervical cancer via the miR-144-3p/CEP55 pathway

Cervical cancer is the most common gynaecological malignancy, with a high incidence rate and mortality rate in middle‐aged women. Human bone marrow mesenchymal stem cells (hBMSCs) have been implicated in the initiation and subsequent development of cancer, along with the involvement of extracellular vesicles (EVs) mediating intracellular communication by delivering microRNAs (miRNAs or miRs). This study is aimed at investigating the physiological mechanisms by which EVs‐encapsulated miR‐144‐3p derived from hBMSCs might mediate the progression of cervical cancer. The expression profiles of centrosomal protein, 55 Kd (CEP55) and miR‐144‐3p in cervical cancer cell lines and tissues, were quantified by RT‐qPCR and Western blot analysis. The binding affinity between miR‐144‐3p and CEP55 was identified using in silico analysis and luciferase activity determination. Cervical cancer cells were co‐cultured with EVs derived from hBMSCs that were treated with either miR‐144‐3p mimic or miR‐144‐3p inhibitor. Cervical cancer cell proliferation, invasion, migration and apoptosis were detected in vitro. The effects of hBMSCs‐miR‐144‐3p on tumour growth were also investigated in vivo. miR‐144‐3p was down‐regulated, whereas CEP55 was up‐regulated in cervical cancer cell lines and tissues. CEP55 was targeted by miR‐144‐3p, which suppressed cervical cancer cell proliferation, invasion and migration and promoted apoptosis via CEP55. Furthermore, similar results were obtained by hBMSCs‐derived EVs carrying miR‐144‐3p. In vivo assays confirmed the tumour‐suppressive effects of miR‐144‐3p in hBMSCs‐derived EVs on cervical cancer. Collectively, hBMSCs‐derived EVs‐loaded miR‐144‐3p impedes the development and progression of cervical cancer through target inhibition of CEP55, therefore providing us with a potential therapeutic target for treating cervical cancer.

LINC00473 rescues human bone marrow mesenchymal stem cells from apoptosis induced by dexamethasone through the PEBP1‑mediated Akt/Bad/Bcl‑2 signaling pathway

The inhibition of the proliferation and apoptosis of bone marrow-derived mesenchymal stem cells (BMSCs) triggered by the excessive use of glucocorticoids, is considered a potential mechanism for the pathogenesis of steroid-induced osteonecrosis of the femoral head (SONFH). Long non-coding RNAs (lncRNAs) have been proven to influence the proliferation, apoptosis and differentiation of BMSCs by regulating the expression of critical genes. A previous microarray analysis by the authors confirmed the significant downregulation of LINC00473 in human BMSCs (hBMSCs) from patients with SONFH. However, the underlying role and molecular mechanisms of LINC00473 on dexamethasone (Dex)-stimulated hBMSCs remains unknown. In the present study, the expression of LINC00473 was determined in the hBMSCs of patients with SONFH and control patients. In addition, the protective effects and underlying molecular mechanisms of LINC00473 in Dex-stimulated hBMSCs were investigated. The results revealed that LINC00473 expression was significantly down-regulated in hBMSCs from patients with SONFH compared with the controls, and that the upregulation of LINC00473 attenuated the inhibitory effects exerted by 1 µM Dex on the proliferation and apoptosis of hBMSCs. Moreover, the upregulation of LINC00473 significantly promoted the protein expression of phosphorylated (p-)Akt, p-Bcl-2-associated death promoter (p-Bad) and B-cell lymphoma 2 (Bcl-2), whereas it decreased the cleavage of caspase-3, thus preventing the Dex-induced apoptosis of hBMSCs. Of note, the regulatory effects of LINC00473 on the Akt/Bad/Bcl-2 signaling pathway and its anti-apoptotic effects were similar to those of SC79 (an Akt activator), and were inhibited by MK-2206 (an Akt inhibitor). In further experiments, it was found that the upregulation of LINC00473 markedly promoted the phosphorylation of Akt in Dex-stimulated hBMSCs, and increased the protein level of phosphatidylethanolamine-binding protein 1 (PEBP1). Alternatively, the promoting effect on Akt phosphorylation induced by LINC00473 was significantly attenuated following the knockdown of PEBP1. Furthermore, the upregulation of PEBP1 triggered a marked increase in the levels of Akt phosphorylation in Dex-stimulated hBMSCs, which was line with the upregulation of LINC00473. Taken together, the results of the present study demonstrate that LINC00473 has the ability to rescue hBMSCs from Dex-induced apoptosis through the PEBP1-mediated activation of the Akt/Bad/Bcl-2 signaling pathway.

Small RNA sequencing reveals a novel tsRNA-06018 playing an important role during adipogenic differentiation of hMSCs

Transfer RNA-derived small RNAs (tsRNAs), a novel type of non-coding RNA derivative, are able to regulate a wide range of biological processes. What role these tsRNAs play in the regulation of human bone marrow mesenchymal stem cell (hMSCs) adipogenic differentiation remains uncertain. We induced the adipogenic differentiation of human bone marrow mesenchymal cells (hMSCs) and then performed small RNA transcriptomic sequencing, leading us to identify tsRNA-06018 as a target of interest based upon resultant the tsRNA expression profiles. When tsRNA-06018 was knocked down, this led to the inhibition of adipogenesis and a decrease in adipogenic marker expression. When STC2 was overexpressed, this impaired the adipogenic differentiation of these cells. We further used luciferase reporter assays to confirm that tsRNA-06018 directly binds the 3'-untranslated region (3'-UTR) of STC2. In addition, we determined that both knocking down tsRNA-06018 and overexpressing STC2 increased extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation within cells. We also assessed that the adipogenic differentiation of hMSCs in which tsRNA-06018 was knocked down was further enhanced upon the addition of the ERK1/2 inhibitor U0126 as compared tsRNA-06018 knockdown alone. Taken together, using small RNA sequencing we profiled tsRNAs in hMSCs during the process of adipogenesis, leading us to identify tsRNA-06018 as a novel regulator of this differentiation process. This tsRNA was able to regulate adipogenic differentiation by targeting STC2 via the ERK1/2 signalling pathway.

[Effect of micro RNA-335-5p regulating bone morphogenetic protein 2 on osteogenic differentiation of human bone marrow mesenchymal stem cells]

OBJECTIVE

To investigate the effect of micro RNA (miR)-335-5p regulating bone morphogenetic protein 2 (BMP-2) on the osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs).

METHODS

hBMSCs were cultured in vitro and randomly divided into control group (group A), miR-335-5p mimics group (group B), miR-335-5p mimics negative control group (group C), miR-335-5p inhibitor group (group D), and miR-335-5p inhibitor negative control group (group E). After grouping treatment and induction of osteogenic differentiation, the osteogenic differentiation of cells in each group was detected by alkaline phosphatase (ALP) and alizarin red staining; the expressions of miR-335-5p and BMP-2, Runt-related transcription factor 2 (Runx2), osteopontin (OPN), and osteocalcin (OCN) mRNAs were detected by real-time fluorescence quantitative PCR analysis; the expressions of Runx2, OPN, OCN, and BMP-2 proteins were detected by Western blot.

RESULTS

Compared with group A, the relative proportion of ALP positive cells and the relative content of mineralized nodules, the relative expressions of BMP-2, miR-335-5p, OPN, OCN, Runx2 mRNAs, the relative expressions of Runx2, OPN, OCN, and BMP-2 proteins in group B were significantly increased ( P<0.05); the above indexes in group D were significantly decreased ( P<0.05); the above indexes between groups C, E and group A were not significantly different ( P>0.05).

CONCLUSION

miR-335-5p can up-regulate BMP-2 expression and promote osteogenic differentiation of hBMSCs.

miR‑10a‑5p inhibits osteogenic differentiation of bone marrow‑derived mesenchymal stem cells

The use of human bone marrow mesenchymal stem cells (hBMSCs) as a tissue engineering application for individuals affected by osteoporosis and other types of bone loss diseases has been well studied in recent years. The osteogenic differentiation of hBMSCs can be regulated by a number of cues. MicroRNAs (miRNAs/miRs) serve as the key regulators of various biological processes; however, to the best of our knowledge, no information exists with regards to the specific modulatory effects of miR-10a-5p on osteogenic differentiation of hBMSCs. The aim of the present study was to investigate the relationship between hBMSCs and miR-10a-5p and, ultimately, to determine how miR-10a-5p affects the osteogenic differentiation process of hBMSCs in vitro and in vivo. The hBMSCs used in the present study were transfected with mirVana™ miRNA inhibitors and mimics, and transfection efficiency was assessed by fluorescence microscopy and reverse transcription-quantitative PCR (RT-qPCR). Viability of hBMSCs following transfection was analyzed using a Cell Counting Kit-8 assay. The mRNA expression levels of specific osteoblast markers, including alkaline phosphatase (ALP) and runt-related transcription factor 2 (RUNX2) were measured using RT-qPCR and western blot analysis. New bone formation was evaluated by Goldner's trichrome staining and micro-CT analysis in vivo. No significant difference in cell viability was observed among the different groups 24 h post-transfection. Overexpression of miR-10a-5p inhibited the expression of osteoblast makers in hBMSCs, whereas inhibition of miR-10a-5p upregulated the expression of ALP and RUNX2 in vitro. Furthermore, miR-10a-5p acted as a suppressor during the process of new bone formation in vivo. In conclusion, the findings of the present study suggested that miR-10a-5p served as a negative regulatory factor during osteoblast differentiation of hBMSCs and may be utilized in a treatment approach for bone repair in osteogenic-related diseases.

On the in Vitro Biocompatibility Testing of Bioactive Glasses

In this work, a new 3D cellular model-based on human bone marrow mesenchymal stem cells (BM-MSCs)-was used for the first time to test the 45S5 Bioglass^® (45S5). Such a model, previously used to evaluate the biologic performance of two novel bioactive glasses, suggested out the regenerative potential of such materials. In fact, BM-MSCs were able both to adhere and colonize the biomaterials, as well as differentiate toward osteoblasts-even in absence of specific growth factors. Surprisingly, BM-MSCs were not able to colonize 45S5 granules (almost no adhesion and/or colonization was observed), and thus, were not capable of providing any osteogenic differentiation. Therefore, the model seems to suggest that the two novel bioactive glasses have a better biologic performance than 45S5. If this hypothesis is confirmed also by in vivo tests, the 3D model may become a predictive tool for discriminating between different potential bioactive materials by comparatively evaluating them, and preliminarily selecting the best ones in relation to their biocompatibility potential-before proceeding with further experiments in vivo. This approach could favor the reduction of costs and time of pre-clinical and clinical trials.

Cyclin-Dependent Kinase 5 Inhibitor Butyrolactone I Elicits a Partial Agonist Activity of Peroxisome Proliferator-Activated Receptor γ

Adiponectin is an adipocyte-derived cytokine having an insulin-sensitizing activity. During the phenotypic screening of secondary metabolites derived from the marine fungus Aspergillus terreus, a poly cyclin-dependent kinase (CDK) inhibitor butyrolactone I affecting CDK1 and CDK5 was discovered as a potent adiponectin production-enhancing compound in the adipogenesis model of human bone marrow-derived mesenchymal stem cells (hBM-MSCs). CDK5 inhibitors exhibit insulin-sensitizing activities by suppressing the phosphorylation of peroxisome proliferator-activated receptor γ (PPARγ). However, the adiponectin production-enhancing activities of butyrolactone I have not been correlated with the potency of CDK5 inhibitor activities. In a target identification study, butyrolactone I was found to directly bind to PPARγ. In the crystal structure of the human PPARγ, the ligand-binding domain (LBD) in complex with butyrolactone I interacted with the amino acid residues located in the hydrophobic binding pockets of the PPARγ LBD, which is a typical binding mode of the PPARγ partial agonists. Therefore, the adiponectin production-enhancing effect of butyrolactone I was mediated by its polypharmacological dual modulator activities as both a CDK5 inhibitor and a PPARγ partial agonist.

KR‑12‑a6 promotes the osteogenic differentiation of human bone marrow mesenchymal stem cells via BMP/SMAD signaling

Considering the increased resistance to antibiotics in the clinic and the ideal antibacterial properties of KR‑12, the effects of KR‑12‑a6, an important analogue of KR‑12, on the osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs) were investigated. Osteogenic differentiation‑associated experiments were conducted in hBMSCs, and KR‑12‑a6 was used as an additional stimulating factor during osteogenic induction. Quantitative analysis of alkaline phosphatase (ALP) and alizarin red staining, and reverse transcription‑quantitative PCR analysis of the expression of osteogenesis‑associated genes were performed to determine the effects of KR‑12‑a6 on the osteogenic differentiation of hBMSCs. LDN‑212854 was selected to selectively suppress BMP/SMAD signaling. Western blotting was performed to investigate the underlying mechanisms. The intensity of ALP and alizarin red staining gradually increased with increasing KR‑12‑a6 concentrations. KR‑12‑a6 induced the strongest staining at 40 µg/ml, whereas 60 µg/ml and 80 µg/ml concentrations did not further increase the intensity of staining. The mRNA expression levels of RUNX2 and ALP increased in a dose‑dependent manner as early as 3 days post‑KR‑12‑a6 treatment. The mRNA expression of COL1A1, BSP and BMP2 exhibited significant upregulation from day 7 post‑KR‑12‑a6 treatment. In contrast, the mRNA levels of OSX, OCN and OPN were enhanced dramatically at day 14 following KR‑12‑a6 stimulation. Additionally, KR‑12‑a6 significantly promoted the phosphorylation of Smad1/5. Furthermore, LDN‑212854 suppressed the activation of Smad1/5 and inhibited the upregulation of several osteogenic differentiation‑associated genes in KR‑12‑a6‑treated hBMSCs. KR‑12‑a6 promoted the osteogenic differentiation of hBMSCs via BMP/SMAD signaling.

A comparative study of HAMSCs/HBMSCs transwell and mixed coculture systems

Our previous studies indicated that a coculture system containing human amnion-derived mesenchymal stem cells (HAMSCs) and human bone marrow mesenchymal stem cells (HBMSCs) has the potential of application for bone regeneration. However, there is currently no enough comparative investigation between HAMSCs/HBMSCs transwell and mixed coculture systems. This study aimed to assess the phenotype and mechanisms regulated by indirect and direct coculture systems, respectively. Two in vitro models were employed with HAMSCs and HBMSCs at a ratio of 3:1, and then were analyzed by a series of processes, including flow cytometry, alkaline phosphatase (ALP) substrate assays, Alizarin red S staining, quantitative reverse transcription polymerase chain reaction (RT-qPCR), and Western blot analysis. We found that cell proliferation, ALP activity, mineralized matrix formation, and osteoblast-related mRNA expression were accelerated in transwell coculture system compared with mixed coculture system. Conditioned medium from transwell coculture system achieved an elevated level of vascular endothelial growth factor and induced more vascular structures in human umbilical vein endothelial cells than those of mixed coculture system. Moreover, we observed that transwell coculture system, promoted osteogenesis and angiogenesis by maintaining stemness through extracellular regulated protein kinases 1/2 (ERK1/2) mitogen-activated protein kinase (MAPK) signaling pathway. U0126, a selective inhibitor of ERK1/2 MAPK signaling, significantly suppressed maintaining of the stemness-based effects on transwell coculture system. Taken together, our results compared the merits of two different models and clarified the role of HAMSCs/HBMSCs transwell coculture system in the development of bone tissue engineering. © 2019 IUBMB Life, 2019.

Low-intensity pulsed ultrasound promotes the proliferation of human bone mesenchymal stem cells by activating PI3K/AKt signaling pathways

Low-intensity pulsed ultrasound (LIPUS) is a promising therapy that is widely used in clinical applications and fundamental research. Previous research has shown that LIPUS exposure has a positive effect on stem cell proliferation. However, the impact of LIPUS exposure on human bone marrow mesenchymal stem cells (hBMSCs) remains unknown. In our study, the effect and mechanism of LIPUS exposure on the proliferation of hBMSCs were investigated, and the optimal parameters of LIPUS were determined. hBMSCs were obtained and identified by flow cytometry, and the proliferation of hBMSCs was measured using the Cell Counting Kit-8 assay to determine cell cycle and cell count. Expression levels of the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKt) pathway proteins and cyclin D1 were determined by western blot analysis. Next, hBMSCs were successfully cultured and identified as multipotent mesenchymal stem cells. We found that LIPUS could promote the proliferation of hBMSCs when the exposure time was 5 or 10 minutes per day. Furthermore, 50 or 60 mW/cm² LIPUS had a more significant effect on cell proliferation, but if cells were irradiated by LIPUS for 20 minutes once a day, an intensity of at least 50 mW/cm² could markedly inhibit cell growth. Cell cycle analysis demonstrated that LIPUS treatment drives cells to enter S and G2/M phases from the G0/G1 phase. LIPUS exposure increased phosphorylation of PI3K/AKt and significantly upregulated expression of cyclin D1. However, these effects were inhibited when cells were treated with PI3K inhibitor (LY294002), which in turn reduced LIPUS-mediated proliferation of hBMSCs. These results suggest that LIPUS exposure may be involved in the proliferation of hBMSCs via activation of the PI3K/AKt signaling pathway and high expression of cyclin D1, and the intensity of 50 or 60 mW/cm² and exposure time of 5 minutes were determined to be the optimal parameters for LIPUS exposure.

Multifunctional PLGA-based nanoparticles as a controlled release drug delivery system for antioxidant and anticoagulant therapy

Background

Ischemia/reperfusion (I/R) injury causes the generation of many ROS such as H₂O₂ and leads to vascular thrombosis, which causes tissue damage.

Purpose

In this investigation, poly (lactideco-glycolide) (PLGA)-based nanoparticles are used for their anticoagulant and antioxidant properties in vascular therapy.

Methods

Both heparin and glutathione are entrapped on PLGA-stearylamine nanoparticles by layer-by-layer interactions.

Results

The drug release rate is successfully controlled with only 10.3% of the heparin released after 96 hours. An H₂O₂-responsive platform is also developed by combining silk fibroin and horse peroxidase to detect H₂O₂ in this drug delivery system. Besides, hyaluronic acid was decorated on the surface of nanoparticles to target the human bone marrow mesenchymal stem cells (hBMSCs) for cell therapy. The results of an in vitro study indicate that the nanoparticles could be taken up by hBMSCs within 2 hours and exocytosis occurred 6 hours after cellular uptake.

Conclusion

We propose that the multifunctional nanoparticles that are formed herein can be effectively delivered to the site of an I/R injury via the hBMSC homing effect. The proposed approach can potentially be used to treat vascular diseases, providing a platform for hBMSCs for the controlled delivery of a wide range of drugs.

Human amnion-derived mesenchymal stem cells promote osteogenesis of human bone marrow mesenchymal stem cells against glucolipotoxicity

Epidemiological evidence suggests that diabetes mellitus (DM) is an important factor in promoting periodontitis. It not only affects the attachment of connective tissue but also causes loss of alveolar bone. Hence, there is an urgent need to find an effective treatment for DM‐induced bone deficiency. This study aimed to investigate the effects of human amniotic mesenchymal stem cells (HAMSCs) on the proliferation and osteogenic differentiation of DM‐induced human bone marrow mesenchymal stem cells (HBMSCs). High glucose and palmitic acid (GP) were used to mimic DM‐induced glucolipotoxicity. The proliferation levels were measured using flow cytometry. Alkaline phosphatase activity substrate assays, Alizarin red S staining, and western blotting were used to investigate osteogenic differentiation. Oxidative stress was measured by assaying the levels of reactive oxygen species. This study found that glucolipotoxicity caused by GP remarkably inhibited cell proliferation and osteogenesis, and upregulated the oxidative stress level in HBMSCs. However, HAMSCs attenuated HBMSC dysfunction through antioxidant activity by influencing p38 mitogen‐activated protein kinase and vascular endothelial growth factor secretion. In conclusion, our findings indicate that HAMSCs might be suitable for treating DM‐mediated bone deficiency.

Magnesium Deprivation Potentiates Human Mesenchymal Stem Cell Transcriptional Remodeling

Magnesium plays a pivotal role in energy metabolism and in the control of cell growth. While magnesium deprivation clearly shapes the behavior of normal and neoplastic cells, little is known on the role of this element in cell differentiation. Here we show that magnesium deficiency increases the transcription of multipotency markers and tissue-specific transcription factors in human adipose-derived mesenchymal stem cells exposed to a mixture of natural molecules, i.e., hyaluronic, butyric and retinoid acids, which tunes differentiation. We also demonstrate that magnesium deficiency accelerates the osteogenic differentiation of human bone marrow-derived mesenchymal stem cells. We argue that magnesium deprivation generates a stressful condition that modulates stem cell plasticity and differentiation potential. These studies indicate that it is possible to remodel transcription in mesenchymal stem cells by lowering extracellular magnesium without the need for genetic manipulation, thus offering new hints for regenerative medicine applications.

CD109 released from human bone marrow mesenchymal stem cells attenuates TGF-β-induced epithelial to mesenchymal transition and stemness of squamous cell carcinoma

Although there is increasing evidence that human bone marrow mesenchymal stem cells (hBM-MSCs) play an important role in cancer progression, the underlying mechanisms are poorly understood. Transforming growth factor β (TGF-β) is an important pro-metastatic cytokine. We have previously shown that CD109, a glycosylphosphatidylinositol-anchored protein, is a TGF-β co-receptor and a strong inhibitor of TGF-β signalling. Moreover, CD109 can be released from the cell surface. In the current study, we examined whether hBM-MSCs regulate the malignant properties of squamous cell carcinoma cells, and whether CD109 plays a role in mediating the effect of hBM-MSCs on cancer cells. Here we show that hBM-MSC-conditioned medium decreases proliferation and induces apoptosis in human squamous carcinoma cell lines, A431 and FaDu. Importantly, hBM-MSC-conditioned medium markedly suppresses markers of epithelial-to-mesenchymal transition and stemness, and concomitantly decreases cell migration, invasion, and spheroid formation in A431 and FaDu cells. In addition, knockdown of CD109 in hBM-MSCs abrogates the anti-malignant activity of hBM-MSC-conditioned medium on A431 and FaDu cells. Furthermore, overexpression of CD109 in A431 cells decreases their malignant traits. Together, our findings suggest that hBM-MSCs inhibit the malignant traits of squamous cell carcinoma cells by a paracrine effect via released factors and that CD109 released from hBM-MSCs, at least partially, mediates these effects.

[Immunomodulatory effects of human amniotic versus bone marrow-derived mesenchymal stem cells on peripheral blood T lymphocytes in vitro]

OBJECTIVE

To compare the immunomodulatory effects of human amniotic mesenchymal stem cell (hAMSCs) and human bone marrow mesenchymal stem cells (hBMSCs) on peripheral blood T lymphocytes in an in vitro co-culture system.

METHODS

hAMSCs and hBMSCs isolated using enzymatic digestion and Ficoll-Hypaque density gradient centrifugation, respectively, were culture-expanded in vitro to obtain the 4th-generation cells. The two MSCs were co-cultured separately with human peripheral blood mononuclear cells stimulated with phytohemagglutinin (PHA-PBMSC) to investigate the changes in T lymphocyte subsets using flow cytomety and the production of interleukin-2 (IL-2) and IL-10 by the T lymphocytes using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Co-culture with either hAMSCs or hBMSCs significantly increased the proportions of Treg, Th2 and Tc2 and decreased Th1 and Tc1 cell subsets in the PBMCs as compared with the PBMCs cultured alone (P<0.05), and the changes in the PBMCs were similar between the two co-culture systems (P>0.05). In both of the two co-culture systems, IL-2 production by the lymphocytes was significantly lowered (P<0.05) and IL-10 production was significantly increased (P<0.05) as compared with their levels in the PBMCs cultured alone; no significant difference was found in IL-2 or IL-10 levels between the two co-culture systems (P>0.05).

CONCLUSION

The MSCs derived from human amnion and bone marrow have similar immunomodulatory effects on the T lymphocytes, suggesting the possibility of using hAMSCs in the treatment of graft-versus-host disease after allogeneic hematopoietic stem cell transplantation.

* An Engineered Multiphase Three-Dimensional Microenvironment to Ensure the Controlled Delivery of Cyclic Strain and Human Growth Differentiation Factor 5 for the Tenogenic Commitment of Human Bone Marrow Mesenchymal Stem Cells

At present, injuries or rupture of tendons are treated by surgical repair or conservative approaches with unpredictable clinical outcome. Alternative strategies to repair tendon defects without the undesirable side effects associated with the current options are needed. With this in mind, a tissue engineering approach has gained considerable attention as a promising strategy. Here we investigated a synthetic three-dimensional (3D) microenvironment able to interact with stem cells and inducing, via coupled biochemical and physical signals, their early commitment toward the tenogenic lineage. This multiphase 3D construct consisted of a braided hyaluronate elastic band merged with human bone marrow mesenchymal stem cells (hBMSCs) and poly-lactic-co-glycolic acid microcarriers loaded with human growth differentiation factor 5 (hGDF-5) by means of fibrin hydrogel. The multiphase structure allowed hBMSC culture under cyclic strain within a microenvironment where a controlled amount of hGDF-5 was regularly delivered. The cooperative biochemical and physical stimuli induced significantly increased expression of tenogenic markers, such as collagen type I and III, decorin, scleraxis, and tenascin-C, within only 3 days of dynamic hBMSC culture. This approach opens exciting perspectives for future development of engineered tendon tissue substitutes.

Combined effect of pulsed electromagnetic field and sound wave on In vitro and In vivo neural differentiation of human mesenchymal stem cells

Biophysical wave stimulus has been used as an effective tool to promote cellular maturation and differentiation in the construction of engineered tissue. Pulsed electromagnetic fields (PEMFs) and sound waves have been selected as effective stimuli that can promote neural differentiation. The aim of this study was to investigate the synergistic effect of PEMFs and sound waves on the neural differentiation potential in vitro and in vivo using human bone marrow mesenchymal stem cells (hBM-MSCs). In vitro, neural-related genes in hBM-MSCs were accelerated by the combined exposure to both waves more than by individual exposure to PEMFs or sound waves. The combined wave also up-regulated the expression of neural and synaptic-related proteins in a three-dimensional (3-D) culture system through the phosphorylation of extracellular signal-related kinase. In a mouse model of photochemically induced ischemia, exposure to the combined wave reduced the infarction volume and improved post-injury behavioral activity. These results indicate that a combined stimulus of biophysical waves, PEMFs and sound can enhance and possibly affect the differentiation of MSCs into neural cells. Our study is meaningful for highlighting the potential of combined wave for neurogenic effects and providing new therapeutic approaches for neural cell therapy. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:201-211, 2017.

Nanostructured TiO₂ Surfaces Promote Human Bone Marrow Mesenchymal Stem Cells Differentiation to Osteoblasts

Micro- and nano-patterning/modification are emerging strategies to improve surfaces properties that may influence critically cells adherence and differentiation. Aim of this work was to study the in vitro biological reactivity of human bone marrow mesenchymal stem cells (hBMSCs) to a nanostructured titanium dioxide (TiO₂) surface in comparison to a coverglass (Glass) in two different culture conditions: with (osteogenic medium (OM)) and without (proliferative medium (PM)) osteogenic factors. To evaluate cell adhesion, hBMSCs phosphorylated focal adhesion kinase (pFAK) foci were analyzed by confocal laser scanning microscopy (CLSM) at 24 h: the TiO₂ surface showed a higher number of pFAK foci with respect to Glass. The hBMSCs differentiation to osteoblasts was evaluated in both PM and OM culture conditions by enzyme-linked immunosorbent assay (ELISA), CLSM and real-time quantitative reverse transcription PCR (qRT-PCR) at 28 days. In comparison with Glass, TiO₂ surface in combination with OM conditions increased the content of extracellular bone proteins, calcium deposition and alkaline phosphatase activity. The qRT-PCR analysis revealed, both in PM and OM, that TiO₂ surface increased at seven and 28 days the expression of osteogenic genes. All together, these results demonstrate the capability of TiO₂ nanostructured surface to promote hBMSCs osteoblast differentiation and its potentiality in biomedical applications.

Gene expression profiling of human bone marrow-derived mesenchymal stem cells during adipogenesis

INTRODUCTION

Adipogenesis comprises multiple processes by which mesenchymal stem cells differentiate into adipocytes. To increase our knowledge of the mechanism underlying adipogenic differentiation of human bone marrow mesenchymal stem cells (hMSCs), we performed full-genome gene expression microarray and gene ontology analyses of induced differentiation of hMSCs.

MATERIAL AND METHODS

Adipogenic differentiation of hMSCs was induced by an adipogenic medium, and total RNA was extracted from undifferentiated hMSCs (day 0) and differentiated adipocytes (day 14). Then microarray hybridization of RNA samples was performed. The GeneChip Operating Software was used to analyze the hybridization data to identify differentially expressed genes, which were performed Gene Ontology categorization and pathway analysis. Pathway-act-network and genes-act-network were built according to the Kyoto Encyclopedia of Genes and Genomes database. Some differentially expressed genes were subjected to qRT-PCR to verify the microarray data.

RESULTS

We detected a total of 3,821 differentially expressed genes, of which 753 were upregulated and 3,068 downregulated. These genes were well represented in a variety of functional categories, including collagen fibril organization, brown fat cell differentiation, cell division, and S phase of mitotic cell cycle. Subsequently, pathway analysis was conducted, and significant pathways (from top 50) were selected for pathway-act-network analysis, which indicated that the mitogen-activated protein kinase (MAPK) pathway and cell cycle were of high degrees (> 10). Gene-act-network analysis showed that insulin-like growth factor 1 receptor (IGF1R), histone deacetylase 1 (HDAC1), HDAC2, MAPK13, MAPK8, phosphoinositide-3-kinase regulatory subunit 1 (PI3KR1), and PI3KR2 also had high degrees (> 18).

CONCLUSIONS

Collectively, these data provide novel information and could serve as a basis for future study to clarify the mechanisms underlying adipocyte differentiation of hMSCs.

[Expression of miR-140-5p and prediction of its target gene in human mesenchymal stem cells during adipogenic differentiation]

OBJECTIVE

To screen the differentially expressed miRNAs and their target genes in adipogenic differentiation of human bone marrow mesenchymal stem cells (hMSCs) to better understand the mechanism for regulating the balance between osteoblast and adipocyte differentiation.

METHODS

Cultured hMSCs were induced for adipogenic differentiation, and at 0, 7, 14, and 21 days of induction, the cells were examined for miRNA and mRNA expression profiles using miRNA chip and transcriptome sequencing (RNA-seq) techniques. Correlation analysis was carried out for the miRNAs and mRNAs of potential interest. The databases including TargetScan, PicTar and miRanda were used to predict the target genes of the differentially expressed miRNA.

RESULTS

The expression of miR-140-5p was down-regulated and leukemia inhibitory factor receptor (LIFR) expression increased progressively during adipogenic differentiation of hMSCs, showing a negative correlation between them. Target gene prediction using the 3 databases identified LIFR as the target gene of miR-140-5p.

CONCLUSION

miRNA-140-5p may play an important role by regulating its target gene LIFR during adipogenic differentiation of hMSCs.

Role of (-)-epigallocatechin-3-gallate in the osteogenic differentiation of human bone marrow mesenchymal stem cells: An enhancer or an inducer?

Epidemiological investigations have revealed that the consumption of green tea, which is a rich source of (-)-epigallocatechin-3-gallate (EGCG), is associated with a reduced risk of osteoporosis. A number of in vitro and in vivo studies have also demonstrated that EGCG exerts a significant positive effect on osteogenesis; however, the single effect of EGCG on osteogenic differentiation has been seldom studied. EGCG was hypothesized to function as an enhancer or an inducer. In the present study, the effect of EGCG on the osteogenic differentiation of primary human bone marrow mesenchymal stem cells (hBMSCs), without other additives, was investigated. Three groups of stem cells were analyzed, which included a negative control group (hBMSCs cultured with culture medium only), an experimental group (cells treated with culture medium containing 2.5, 5 and 10 µM EGCG), and a positive control group (cells cultured with osteogenesis-induced culture medium). After 3, 7, 14 and 21 days, cell proliferation, alkaline phosphatase (ALP) activity and the expression of associated osteogenic genes were analyzed. The results revealed that ALP activity and the expression of associated osteogenic genes, with the exception of bone morphogenetic protein 2 (BMP2), were not affected by EGCG treatment alone. These results indicated that EGCG itself had little effect on the osteogenic differentiation of MSCs; however, EGCG was able to enhance osteogenesis in the presence of osteoinductive agents through the upregulation of BMP2 expression. Additionally, EGCG was shown to promote cell growth, demonstrating its safety as a therapeutic agent. Therefore, the present study indicated that treatment with EGCG was dependent on other osteogenic inducers.

Human bone marrow mesenchymal stem cell transplantation attenuates axonal injury in stroke rats

Previous studies have shown that transplantation of human bone marrow mesenchymal stem cells promotes neural functional recovery after stroke, but the neurorestorative mechanisms remain largely unknown. We hypothesized that functional recovery of myelinated axons may be one of underlying mechanisms. In this study, an ischemia/reperfusion rat model was established using the middle cerebral artery occlusion method. Rats were used to test the hypothesis that intravenous transplantation of human bone marrow mesenchymal stem cells through the femoral vein could exert neuroprotective effects against cerebral ischemia via a mechanism associated with the ability to attenuate axonal injury. The results of behavioral tests, infarction volume analysis and immunohistochemistry showed that cerebral ischemia caused severe damage to the myelin sheath and axons. After rats were intravenously transplanted with human bone marrow mesenchymal stem cells, the levels of axon and myelin sheath-related proteins, including microtubule-associated protein 2, myelin basic protein, and growth-associated protein 43, were elevated, infarct volume was decreased and neural function was improved in cerebral ischemic rats. These findings suggest that intravenously transplanted human bone marrow mesenchymal stem cells promote neural function. Possible mechanisms underlying these beneficial effects include resistance to demyelination after cerebral ischemia, prevention of axonal degeneration, and promotion of axonal regeneration.

Comparative Study of Microtubule-associated Protein-2 and Glial Fibrillary Acidic Proteins during Neural Induction of Human Bone Marrow Mesenchymal Stem Cells and Adipose-Derived Stem Cells

BACKGROUND

In recent years, adipose tissue, due to the stem cells contained within, has found a new special place in laboratory and clinical applications. These adipose-derived stem cells (ADSCs) have the same characteristics of bone marrow mesenchymal stem cells (BMSCs). Although bone marrow (BM) is not easily accessible and its procurements may be painful, most patients possess excess fat which can be obtained by less invasive methods; this makes adipose tissue ubiquitous, available and an ideal large-scale source for research on clinical applications.

METHODS

BMSCs and ADSCs were harvested from three healthy human and were characterized using flow-cytometry. After they were treated for neurosphere formation using basic fibroblast growth factor, epidermal growth factor, B 27; terminal differentiation was performed. In this study, we used immunocytochemistry, real time-polymerase chain reaction and western blotting techniques for detection and comparison of Nestin, microtubule-associated protein-2 (MAP-2) and glial fibrillary acidic protein (GFAP) markers in human ADSCs and BMSCs.

RESULTS

Under appropriate conditions ADSCs can differentiate into neuron-like cells and express neural markers the same as BMSCs, also the expression of GFAP marker in differentiated cells derived from ADSCs was significantly lower than the cells derived from BMSCs (P < 0.05). While the expression of MAP-2 marker in both groups was the same.

CONCLUSIONS

However, due to its advantages and according to our results based on the expression levels of GFAP and MAP-2, adipose tissue rather than BM could represent a more appropriate stem cell source for investigating the application of these cells in understanding the pathophysiology and in treatment of neurodegenerative disorders.

GRP78 secreted by tumor cells stimulates differentiation of bone marrow mesenchymal stem cells to cancer-associated fibroblasts

Cancer-associated fibroblasts (CAFs), one type of tumor-associated stromal cells, have been shown to provide a favorable environment for the malignant tumor progression. Extensive reports have demonstrated that mesenchymal stem cells (MSCs) can function as precursors for CAFs. However, the mechanisms by which tumor cells induce the transition of MSCs to CAFs have not been well established. GRP78, traditionally known as an endoplasmic reticulum (ER) chaperone, has been identified to overexpress in a variety of tumor entities and be involved in promoting survival and chemoresistance of tumor cells. Here, we interrogated the role of GRP78 in the generation of CAFs from MSCs. The results showed that GRP78 treatment induced expression of α-smooth muscle actin (α-SMA), a marker for CAFs, in human bone marrow mesenchymal stem cells (HBMSCs) as well as murine bone marrow mesenchymal stem cells (BMMSCs). This phenomenon was correlated with the stimulated phosphorylation of Smad2/3. Furthermore, the GRP78-induced α-SMA expression in HBMSCs was obviously attenuated by SB431542, a TGF-β type I receptor kinase inhibitor. Taken together, the present data suggested that tumor-derived secreted GRP78 elicited the differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) to CAFs through activating TGF-β/Smad signaling pathway, which may represent a novel mechanism for transition of BMSCs to CAFs and a hitherto unknown function of GRP78 in the tumor microenvironment.