A digital workflow for fabricating a polyetherketoneketone (PEKK) periodontal splint is described. The antibacterial properties of PEKK and the precision and efficiency of digital technology led to the provision of a splint with no adverse effects on oral hygiene or periodontal maintenance during a 2-year follow-up.

Immune thrombocytopenia (ITP) is a common hematological disorder. Our previous study has found that exosomal miR-146a-5p derived from bone marrow mesenchymal stromal cells (BMSCs) regulate Th17/Treg balance to alleviate ITP. This work further investigated the role of miR-146a-5p in ITP with pregnancy. Compared with healthy pregnant volunteers, the levels of Th1 cells and IFN-γ were increased, the levels of Th2 cells and IL-4 were decreased in peripheral blood of ITP patients with pregnancy. Then, human BMSCs-exosomes repressed the ratio of Th1/Th2 cells in CD4+ T cells, while BMSCs-exosomes with miR-146a-5p inhibitor increased Th1/Th2 cell ratio. Moreover, an ITP mouse model with pregnancy was constructed by administering anti-CD41 antibody in pregnant mice to verify the role of BMSCs-Exo in vivo. BMSCs-Exo elevated the number of platelet and megakaryocyte, improved the function of gastric, spleen and thymus tissues in ITP mice with pregnancy, which attributed to delivery miR-146a-5p. Furthermore, miR-146a-5p interacted with CARD10, and then repressed CARD10/NF-κB signaling pathway. BMSCs-exosomes promoted proliferation and inhibited apoptosis of Dami cells. In conclusion, BMSCs-exosomal miR-146a-5p reduced Th1/Th2 cell ratio to elevate proliferation and inhibit apoptosis of Dami cells, thereby alleviating ITP with pregnancy development. Therefore, miR-146a-5p may be a target for ITP with pregnancy treatment.

The ability to control stem cell function is the key to stem cell-based therapy and living tissue regeneration. In natural conditions, histone deacetylases (HDAC) are regarded as the important defining epigenetic reprogramming for stem cell differentiation. To date, human adipose-derived stem cells (hADSCs) have been widely utilised for bone tissue engineering applications. The present study aimed to examine the effect of a novel HDAC2&3-selective inhibitor, MI192, on hADSCs epigenetic reprogramming for regulating its osteogenic potential in vitro. The results confirmed that MI192 treatment reduced the hADSCs viability in a time and dose-dependent manner. The optimal concentration and pre-treatment time of MI192 for hADSCs osteogenic induction was 30 μM and 2 days representatively. A quantitative biochemical assay confirmed that the pre-treatment with MI192 (30 μM) for 2 days significantly enhanced hADSCs alkaline phosphatase (ALP) specific activity (P<0.05) compared with that of the valproic acid (VPA) pre-treatment group. Real-time PCR analysis revealed that MI192 pre-treatment up-regulated hADSCs gene expressions of osteogenic markers (e.g., Runx2, Col1, and OCN) under the osteogenic induction. DNA flow cytometric analysis indicated that two days’ pre-treatment with MI192 (30 μM) resulted in G2/M arrest in hADSCs and this G2/M arrest was reversible. Our results suggest that MI192 is capable of epigenetic reprogramming of hADSCs via HDAC inhibition for controlling the cell cycle, resulting in enhancing hADSCs osteogenic differentiation, which indicates the potential of using MI192 for promoting bone tissue regeneration.

OBJECTIVES:The regulatory mechanisms of GCN5 (General control non-repressed protein5) in the osteogenic differentiation of mesenchymal stem cells (MSCs) in periodontitis are still unclear. The purpose of this review focuses on the regulating roles of GCN5 in bone metabolism and periodontitis, discusses the potential molecular mechanism and provides targets and new ideas for the treatment of periodontitis.MATERIAL AND METHODS:The integrative review methodology was used. Data sources include PubMed, Cochrane Library, and additional sources.RESULTS:MSCs play an important role in the osteogenesis balance of periodontal tissue. Periodontal ligament stem cells (PDLSCs) from periodontitis patients exhibited defective osteogenic differentiation capacities. Histone acetylation is important in regulating the differentiation of different types of MSCs cells and is closely related to the reduced osteogenic differentiation of PDLSCs. GCN5, one of the first histone acetyltransferase linked to gene transcriptional activation, participates in many biological processes of mesenchymal stem cells. Downregulation of GCN5 expression and lack of GCN5 caused decreased osteogenic differentiation of PDLSCs. Intercellular information exchange may be an important way for MSCs to exert their regulatory and therapeutic functions.CONCLUSIONS:GCN5 affects the function of cell metabolism-related genes by regulating the acetylation status of histones or non-histones, thereby regulating some important progress of MSCs such as PDLSCs' osteogenic differentiation and BMCS osteogenic differentiation.

Immune thrombocytopenia (ITP) is an acquired autoimmune hemorrhagic disorder characterized by persistent thrombocytopenia. It may be induced by different pathogenesis due to its heterogeneity, and the therapeutic effects vary on different patients. Bone marrow derived mesenchymal stem cells (BMMSCs) can modulate innate and adaptive immunity, thus resulting in a tolerant microenvironment. Functional defects and immunomodulatory disorders of BMMSCs are significant causes of ITP. Functional effects associated with the activation of the P53 pathway include decreased activity of the phosphatidylinositol 3 kinase/AKT pathway and activation of the TNFAIP3/NF-κB/SMAD7 pathway. Immune dysfunction appears to be correlated with an impaired ability of BMMSCs to induce various types of immune cells in ITP. An in-depth investigation into the pathogenesis of ITP facilitates the treatment of ITP, but larger-scale clinical trials are needed to verify the efficacy of exogenous BMMSCs in the clinical treatment of ITP.

This clinical report describes the fabrication of conventional complete dentures with polyetherketoneketone (PEKK) frameworks made with computer-aided design and computer-aided manufacturing (CAD-CAM). No biologic or prosthetic complications were observed at the 1-year follow-up.

SHP2, encoded by the PTPN11 gene, participates in multiple cell functions including cell proliferation, movement, and differentiation. PTPN11 loss-of-function and gain-of-function mutations are both associated with diseases, such as Noonan syndrome, whose manifestations include bone defects, suggesting a crucial role for SHP2 in the skeleton. However, the exact mechanisms by which SHP2 regulates bone development remain unclear. This review focuses on the current understanding of the regulation of SHP2 and highlights the vital roles of SHP2 in skeletal development, especially its roles in ossification. Overall, a better understanding of the functions of SHP2 in ossification will provide a new avenue to treat-related skeletal diseases.

Xeroderma Pigmentosum group D (XPD) gene has been shown to suppress hepatocellular carcinoma (HCC) progression, but its mechanism remains not fully understood. ETS-related gene (ERG) is generally known as an oncogenic gene. This study aimed to explore whether XPD regulated HCC cell proliferation, apoptosis and cell cycle by inhibiting ERG expression via the PPARγ pathway. The human hepatoma cells (HepG2) were transfected with the XPD overexpression vector (pEGFP-N2/XPD) or empty vector (pEGFP-N2). The PPARγ inhibitor GW9662 was used to determine whether XPD effects were mediated by activation of PPARγ pathway. Cell cycle and apoptosis were ascertained by flow cytometry, and cell viability was measured by MTT assay. Reverse transcription-polymerase chain reaction and Western blot were performed to determine the mRNA and protein levels. Overexpression of XPD significantly enhanced the expression of PPARγ and p-PPARγ, whereas it downregulated that of ERG and cdk7. Furthermore, XPD overexpression notably inhibited proliferation, promoted apoptosis and decreased the percentage of cells in the S + G2 phase of HepG2 cells. However, these effects of XPD overexpression were abrogated by GW9662. Collectively, XPD suppresses proliferation and promotes apoptosis of HepG2 cells by downregulating ERG expression via activation of the PPARγ pathway.

Bone marrow mesenchymal stem cells (BMSCs) in acute myeloid leukemia (AML) microenvironment undergo modification that includes expression of contents in the small-sized extracellular vesicles (EVs) they secrete. This study aims to investigate whether small-sized EVs from BMSCs of AML patients regulate AML progression by modifying the expression of miR-26a-5p. Small-sized EVs from BMSCs of AML patients (AML-BMSC-EVs) or healthy controls (HC-BMSC-EVs) were isolated by ultra-centrifugation and administered to AML cells (OCI/AML-2 and THP-1). Cell proliferation, migration, and invasion were evaluated by CCK-8 assay, Transwell migration and invasion assays, respectively. Compared with HC-BMSC-EVs, AML-BMSC-EVs contained higher expression of miR-26a-5p and promoted AML cell proliferation, migration, and invasion. Inhibition of miR-26a-5p expression in AML-BMSC-EVs could abrogate the promoting effects of AML-BMSC-EVs on AML cell proliferation, migration, and invasion. Furthermore, GSK3β was a direct target of miR-26a-5p. Moreover, AML-BMSC-EVs inhibited GSK3β expression and activated Wnt/β-catenin signaling in AML cells. Additionally, GSK3β overexpression in THP-1 cells counteracted the promoting effects of AML-BMSCs-EVs on THP-1 cell proliferation, migration, and invasion. AML-BMSC-EVs promoted AML progression by transferring miR-26a-5p to AML cells and subsequently activating the Wnt/β-catenin pathway.

Bone marrow mesenchymal stem cells (BMSCs) are associated with immune thrombocytopenia (ITP), the underlying mechanism has not been fully elucidated. Here, we attempted to investigate whether BMSCs can regulate Th17/Treg imbalance in ITP through the exosome pathway. We first assessed the proportions of Th17 cells and Tregs in ITP patients, showing that ITP patients exhibited an evident imbalance of Th17/Treg. BMSCs-exosomes' treatment significantly reduced Th17/Treg ratio in the CD4+ T cells of ITP patients. Moreover, miR-146a-5p was highly expressed in BMSCs-exosomes. The expression of miR-146a-5p was obviously increased in CD4+ T cells following the treatment of BMSCs-exosomes. BMSCs-exosomal miR-146a-5p silencing promoted the proportions of Th17 cells and repressed the proportions of Tregs in CD4+ T cells. In addition, miR-146a-5p directly interacted with IL-1R-associated kinase-1 (IRAK), and repressed IRAK1 expression. IRAK1 overexpression promoted Th17/Treg ratio in CD4+ T cells, which was abolished by BMSCs-exosomal miR-146a-5p. In conclusion, these findings demonstrate that BMSC-derived exosomal miR-146a-5p regulates Th17/Treg imbalance in ITP by repressing IRAK1 expression. Thus, this work suggests that BMSCs-exosomal miR-146a-5p may be a potential therapeutic target for ITP.

Dental-tissue-derived stem cells have been used for tissue engineering owing to their ease of isolation and efficacy in in vitro and in vivo proliferation and differentiation. Nanohydroxyapatite/chitosan/gelatin (nHA/CG) three-dimensional porous scaffolds are promising for bone tissue engineering, especially jaw bone regeneration, because of their structural and functional similarity to natural bone. In our previous study, the efficiency of scaffolds with stem cell complexes in osteogenesis was confirmed in vivo in immunocompromised mice. However, studies on the bone regeneration efficiency of stem cell-seeded nHA/CG scaffolds using large animal jaw bone defect models have not been conducted. This study evaluated the bone regeneration potential of the nHA/CG scaffolds with transplanted human periodontal ligament stem cells (hPDLSCs) in critical-sized jaw bone defects in minipigs. The hPDLSCs isolated from periodontal ligaments of discarded teeth (postorthodontic purposes) were seeded onto the nHA/CG scaffolds. The scaffold was successfully synthesized according to our previous studies. Forty-eight critical-sized jaw bone defects were created in 12 minipigs. The defects were randomly assigned to one of three groups [scaffolds with seeded hPDLSCs (hPDLSCs/nHA/CG), only scaffold (nHA/CG), and a negative control group, ie, no cells and scaffolds implanted into defects] to investigate jaw bone regeneration. The bone regeneration capacities of the three groups were assessed for up to 12 weeks. The results showed that the hPDLSCs adhered well to the nHA/CG scaffold in vitro, and the cell-nHA/CG composites significantly increased new bone formation and generated large bones with normal architectures and vascularization in vivo compared to the nHA/CG and control groups. Immunohistochemistry staining showed that runt-related transcription factor 2 (Runx2) was highly expressed in the bone marrow formed in the hPDLSCs/nHA/CG group. This study provides strong evidence for future clinical applications of the nHA/CG scaffolds transplanted with hPDLSCs to regenerate the bone in large jaw bone defects.

Mesenchymal Stem Cells (MSCs) exhibit enormous therapeutic potential because of their indispensable regenerative, reparative, angiogenic, anti-apoptotic, and immunosuppressive properties. MSCs can best differentiate into mesodermal cell lineages, including osteoblasts, adipocytes, muscle cells, endothelial cells and chondrocytes. Specific differentiation of MSCs could be induced through limited conditions. In addition to the relevant differentiation factors, drastic changes also occur in the microenvironment to conduct it in an optimal manner for particular differentiation. Recent evidence suggests that the mitochondria participate in the regulating of direction and process of MSCs differentiation. Therefore, our current review focuses on how mitochondria participate in both osteogenesis and adipogenesis of MSC differentiation. Besides that, in our current review, we try to provide a further understanding of the relationship between the behavior of mitochondria and the direction of MSC differentiation, which could optimize current cellular culturing protocols for further facilitating tissue engineering by adjusting specific conditions of stem cells.

We investigated the biological functions and mechanism of miRNA-301a on apoptosis in chronic myelogenous leukemia (CML). The expression of mi RNA-301a in patient with CML cells was higher than the expression of normal patients. Overall survival (OS) of chronic granulocytic leukemia cell patient with low miRNA-301 expression was superior to that of CML patient with high miRNA-301 expression. Moreover, the upregulation of miRNA-301a increased cell proliferation, inhibited apoptosis and caspase-3 and-9 activity of K562 cells. Next, the upregulation of miRNA-301a suppressed Bax/Bcl-2 rate and TIMP2 protein expression, increased phosphorylation-ERK1/2 and decreased phosphorylation-AKT protein expression of K562 cells. Furthermore, si-TIMP2 expression enhanced the upregulation of miRNA-301a on the promotion of cell proliferation, inhibition of apoptosis and caspase-3 and -9 activity, suppression of Bax/Bc1-2 rate, increasing phosphorylation-ERK1/2 and decreasing phosphorylation-AKT protein expression of K562 cells. Taken together, our results clearly suggested that miRNA-301a induces apoptosis of CML cells by directly targeting the TIMP2/ERK1/2 and AKT pathways.

Translational research in bone tissue engineering is essential for "bench to bedside" patient benefit. However, the ideal combination of stem cells and biomaterial scaffolds for bone repair/regeneration is still unclear. The aim of this study is to investigate the osteogenic capacity of a combination of poly(DL-lactic acid) (PDLLA) porous foams containing 5 wt% and 40 wt% of Bioglass particles with human adipose-derived stem cells (ADSCs) in vitro and in vivo. Live/dead fluorescent markers, confocal microscopy and scanning electron microscopy showed that PDLLA/Bioglass porous scaffolds supported ADSC attachment, growth and osteogenic differentiation, as confirmed by enhanced alkaline phosphatase (ALP) activity. Higher Bioglass content of the PDLLA foams increased ALP activity compared with the PDLLA only group. Extracellular matrix deposition after 8 weeks in the in vitro cultures was evident by Alcian blue/Sirius red staining. In vivo bone formation was assessed by using scaffold/ADSC constructs in diffusion chambers transplanted intraperitoneally into nude mice and recovered after 8 weeks. Histological and immunohistochemical assays indicated significant new bone formation in the 40 wt% and 5 wt% Bioglass constructs compared with the PDLLA only group. Thus, the combination of a well-developed biodegradable bioactive porous PDLLA/Bioglass composite scaffold with a high-potential stem cell source (human ADSCs) could be a promising approach for bone regeneration in a clinical setting.

<正>间充质干细胞(MSCs)[1-3]是一类具有自我更新和多向分化潜能的成体干细胞,在组织修复和再生的过程中起着非常重要的作用。MSCs可在体外进行培养扩增,在应用激素或生长因子的适当培养条件下可分化为成骨细胞、脂肪细胞、软骨细胞、神经细胞以及肌肉细胞等多种组织细胞[4-7]。MSCs可以从多种组织器官中分离出来,如骨髓、脐带血和脂肪[8]。其中,骨髓间充质干细胞(BMSC)是研究较多的一种成体干细胞,

Many studies demonstrate that the type of adjacent mesenchymal cells can affect epidermal morphogenesis of bilayered tissue-engineered skin. However, whether a mixture of different mesenchymal cell types can improve epidermal morphogenesis of bioengineered skin remains unknown. In this study, keratinocytes, dermal fibroblasts and adipose tissue-derived stem cells (ADSCs) were isolated and purified from human skin and subcutaneous fat. Conditioned medium generated from a mixture of dermal fibroblasts and ADSCs at the ratio of 1:1 was superior to that from fibroblasts or ADSCs alone in promoting keratinocyte proliferation, as indicated by MTT assay. Furthermore, ELISA results showed that the cytokine levels of human hepatocyte growth factor and keratinocyte growth factor (also known as FGF7) in the mixed fibroblasts/ADSC group were higher than those in the ADSC or dermal fibroblasts group. To examine the potential roles of mixed fibroblasts and ADSCs on epidermal morphogenesis, a three-dimensional tissue engineered skin system was applied. Histological analyses demonstrated that keratinocytes proliferated extensively over the mixture of fibroblasts and ADSCs, and formed a thick epidermal layer with well-differentiated structures. Keratin 10 (epidermal differentiation marker) was expressed in the suprabasal layer of bilayered tissue-engineered skin in the mixed fibroblasts and ADSCs group. Desmosomes and hemidesmosomes were detected in the newly formed epidermis by transmission electron microscopy analysis. Together, these findings revealed for the first time that a mixture of fibroblasts and ADSCs in bilayered tissue-engineered skin can improve epidermal morphogenesis.

This paper is aimed to investigate the repair of rabbit radial bone defect by the recombinant human bone morphogenetic protein 2/poly-lactideco-glycolic acid microsphere with fibrin sealant (rhBMP-2/PLGA/FS). The radial bone defect models were prepared using New Zealand white rabbits, which were randomly divided into 3 groups, experiment group which were injected with eMP-2/PLGA/FS at bone defect location, control group which were injected with FS at bone defect location, and blank control group without treatment. The ability of repairing bone defect was evaluated with X-ray radiograph. Bone mineral density in the defect regions was analysed using the level of ossification. The osteogenetic ability of repairing bone defect, the degradation of the material, the morphologic change and the bone formation were assessed by HE staining and Masson staining. The result showed that rhBMP-2/PLGA/FS had overwhelming superiority in the osteogenetic ability and quality of bone defect over the control group, and it could promote the repair of bone defect and could especially repair the radial bone defect of rabbit well. It may be a promising and efficient synthetic bone graft.

Cell/microcarrier combinations can be injected to repair tissue defects, but whether currently available microcarriers can be utilized to repair different tissue defects remains unknown. Here, we compared the suitability of fabricated micronized acellular dermal matrix (MADM), micronized small intestinal submucosa (MSIS), and gelatin microspheres as expansion and delivery scaffolds for adipose-derived mesenchymal stem cells (ADSCs). The results of MTS assay, scanning electron microscopy (SEM), and flow cytometry suggested that the three microcarriers all have good biocompatibility. Quantitative polymerase chain reaction revealed enhanced epidermal growth factor, vascular endothelial growth factor, basal fibroblast growth factor, and transforming growth factor-β expression levels after ADSCs had been cultured on MADM or MSIS for 5 days. After culturing ADSCs on microcarriers in osteogenic medium for 7 days, the expression levels of bone formation-related genes were enhanced. ADSC/microcarrier treatment accelerated wound closure. The ADSC/MADM and ADSC/MSIS combinations retained more of the original implant volume at 1 month postimplantation than ADSC/gelatin microspheres combination in soft-tissue augmentation studies. All implants displayed fibroblast and capillary vessel infiltrations; but ectopic bone formation did not occur, and the calvarial defect repair results were unfavorable. Our study demonstrates the potential utility of these microcarriers not only as a cell-culture substrate but also as a cell-transplantation vehicle for skin regeneration and soft-tissue reconstruction.

BACKGROUND: Refractory wound is difficult to treat using traditional methods in the clinic. Studies have shown that growth factor plays an important role in wound healing, and transgenic therapy is emerging to treat refractory wound. OBJECTIVE: To review the research status and progress of treating refractory wound by summarizing literatures concerning gene therapy. METHODS: PubMed database was searched by the first author using key words of "gene therapy, burns, chronic wounds" for English papers published between January 1999 and December 2008. Documents with regard to refractory wound and gene therapy were included. Totally 33 literatures were analyzed. RESULTS AND CONCLUSION: According to sources of transfected cells, the transgenic technology can be divided into in vivo gene transfection and in vitro gene transfection. The in vivo gene transfection processes greater superiority than other methods. Though it can not be spread in clinical application, transgenic technology owns extensive prospect.