TDP-43 ameliorates aging-related cartilage degradation through preventing chondrocyte senescence.

Senescent chondrocytes or signaling mechanisms leading to senescence are promising new therapeutic approaches for ameliorating cartilage degradation. Herein, we show that the transactive response DNA/RNA-binding protein (TDP-43) regulates chondrocyte senescence and ameliorates cartilage degradation. First, a significant decrease in TDP-43 was observed in 16-month-old mice compared with younger mice. Immunohistochemistry (IHC) analysis of mouse articular cartilage showed that p21, p16, p53, and matrix metalloprotein-13 (MMP13) were increased, but laminB1 and Collagen type II alpha1 1 chain (Col2a1) were decreased in 16-month-old mice. Furthermore, TDP-43 levels were decreased in vivo following D-galactose (D-gal) induction. Therefore, we investigated the role of TDP-43 in the senescent chondrocytes. ATDC5 cells were induced to overexpress TDP-43. Western blot analysis showed increased expression of laminB1, Ki67, and PCNA but decreased expression of p21, p16, p53, and MMP13. Senescence-associated-ß-galactosidase (SA-ß-Gal) assay, γH2AX staining, and EdU were performed to assess changes in chondrocytes, showing weaker SA-ß-Gal and γH2AX staining but stronger EdU and Alican Blue staining. However, TDP-43 deficiency had opposing effects, and similar to D-gal stimulation results. Taken together, our data verified that TDP-43 negatively correlated with senescence markers, positively correlated with cell proliferation markers, and could alleviate cartilage degradation induced by D-gal. This may be an essential mechanism of cellular senescence and cartilage degradation.

Enhancing clinical safety in bioengineered-root regeneration: The use of animal component-free medium.

Background: Most studies used animal serum-containing medium for bioengineered-root regeneration, but ethical and safety issues raised by animal serum are a potentially significant risk for clinical use. Thus, this study aimed to find a safer method for bioengineered-root regeneration. Methods: The biological properties of human dental pulp stem cells (hDPSCs) cultured in animal component-free (ACF) medium or serum-containing medium (5%, 10% serum-containing medium, SCM) were compared in vitro. hDPSCs were cultured in a three-dimensional (3D) environment with human-treated dentin matrix (hTDM). The capacity for odontogenesis was compared using quantitative real-time PCR (qPCR) and Western blot. Subsequently, the hDPSCs/hTDM complexes were transplanted into nude mice subcutaneously. Histological staining was then used to verify the regeneration effect in vivo. Results: ACF medium promoted the migration of hDPSCs, but slightly inhibited the proliferation of hDPSCs in the first three days of culture compared to SCM. However, it had no significant effect on cell aging and apoptosis. After 7 days of 3D culture in ACF medium with hTDM, qPCR showed that DMP1, DSPP, OCN, RUNX2, and ß-tubulin III were highly expressed in hDPSCs. In addition, 3D cultured hDPSCs/hTDM complexes in ACF medium regenerated dentin, pulp, and periodontal ligament-like tissues similar to SCM groups in vivo. Conclusion: ACF medium was proved to be an alternative medium for bioengineered-root regeneration. The strategy of using ACF medium to regenerate bioengineered-root can improve clinical safety for tooth tissue engineering.

High-yield nanovesicles extruded from dental follicle stem cells promote the regeneration of periodontal tissues as an alternative of exosomes.

AIM: To identify an optimized strategy for the large-scale production of nanovesicles (NVs) that preserve the biological properties of exosomes (EXOs) for use in periodontal regeneration. MATERIALS AND METHODS: NVs from dental follicle stem cells (DFSCs) were prepared through extrusion, and EXOs from DFSCs were isolated. The yield of both extruded NVs (eNVs) and EXOs were quantified through protein concentration and particle number analyses. Their pro-migration, pro-proliferation and pro-osteogenesis capacities were compared subsequently in vitro. Additionally, proteomics analysis was conducted. To further evaluate the periodontal regeneration potential of eNVs and EXOs, they were incorporated into collagen sponges and transplanted into periodontal defects in rats. In vivo imaging and H&E staining were utilized to verify their biodistribution and safety. Micro-Computed Tomography analysis and histological staining were performed to examine the regeneration of periodontal tissues. RESULTS: The yield of eNVs was nearly 40 times higher than that of EXOs. Interestingly, in vitro experiments indicated that the pro-migration and pro-proliferation abilities of eNVs were superior, and the pro-osteogenesis potential was comparable to EXOs. More importantly, eNVs exhibited periodontal regenerative potential similar to that of EXOs. CONCLUSIONS: Extrusion has proven to be an efficient method for generating numerous eNVs with the potential to replace EXOs in periodontal regeneration.

Effect of a digital assessment system for the preclinical tooth preparation of metal-ceramic crowns: A pilot study.

STATEMENT OF PROBLEM: Tooth preparation is a fundamental aspect of prosthodontics and serves as a focal point in preclinical courses. Conventional pedagogy relies heavily on the expertise of instructors, whereas digital technology has the potential to offer instantaneous feedback. The efficacy of a digital assessment system in comparison with traditional teaching methods remains uncertain. PURPOSE: The purpose of this study was to compare the training effects of traditional assessment and digital evaluation on tooth preparations for the metal-ceramic crowns performed by preclinical students on the convergence angle and tooth reduction. MATERIAL AND METHODS: A total of 40 predoctoral students were randomly divided into the digital group and the traditional group to complete tooth preparation for a metal-ceramic crown on a left mandibular first molar. Students in the traditional group were taught by an experienced instructor, while the digital group students were trained by an objective digital assessment system without instructor guidance. Each student completed the tooth preparation in 20 min, received feedback according to the respective training methods, and later prepared another tooth. In this way, all students completed 4 tooth preparations in 2 weeks. All preparations were evaluated by an optical scanner. Parameters for comparing the digital group with the traditional group were the convergence angle and reduction at different stages. Questionnaires on the digital training system were answered by the students of the digital group. The t tests or Wilcoxon signed rank tests and chi-squared tests were used to analyze the differences between the 2 groups (α=.01). RESULTS: A decreasing trend in convergence angle was seen in both groups, but the 2 groups were statistically similar (P>.01). After training, a decreasing trend was seen in under-reduction and overreduction on 5 surfaces in the digital group. Conversely, in the traditional group, a noteworthy increase was seen in under-reduction on the distal surface (P=.002). Nevertheless, no significant difference was found between the 2 groups (P>.01). According to the results of the questionnaire, over 80% of the students had a positive attitude toward the digital assessment system, and more than 80% of the students expressed their interest in the digital assessment system for tooth preparation training. CONCLUSIONS: Traditional teaching and digital feedback provided similar training effects to improve the quality of tooth preparations for preclinical dental students.

MiR-3529-3p from PDGF-BB-induced cancer-associated fibroblast-derived exosomes promotes the malignancy of oral squamous cell carcinoma.

AIMS: This study aims to explore the role of exosomes from cancer-associated fibroblasts (CAFs) induced by PDGF-BB in promoting the malignancy of oral squamous cell carcinoma (OSCC) and provide new insight into the mechanism of OSCC progression and its treatment. MAIN METHODS: Exosomes were extracted from human oral mucosa fibroblasts (hOMFs) and CAFs. Differentially expressed miRNAs of exosomes between hOMFs and CAFs were analysed using high-throughput sequencing and self-programmed R software. Cal-27, a human tongue squamous carcinoma cell line, was treated with exosomes. Differentially expressed miRNAs between clinical cancer tissues and adjacent tissues and between hOMF and CAF exosomes were verified by qRT‒PCR. The effect of miR-3529-3p on Cal-27 cells was clarified by overexpressing or knocking down miR-3529-3p in Cal-27 cells. Sample expression and differentially expressed miRNA expression were compared between cancer and paracarcinoma tissues. KEY FINDINGS: We found that exosomes from CAFs (CAF-Exos) were internalized by tongue squamous carcinoma cells and promoted their proliferation, migration, invasion, and antiapoptotic effects. MiR-3529-3p was a significant differentially expressed miRNA between CAF-Exos and exosomes from hOMFs (hOMF-Exos). The overexpression of miR-3529-3p promoted proliferation, migration, and invasion and inhibited apoptosis of Cal-27 cells. SIGNIFICANCE: This study explores the role of PDGF-BB-induced CAFs in promoting malignancy in OSCC. This study will provide new insight into the mechanism of OSCC progression and its treatment.

Microbe-host interactions: structure and functions of Gram-negative bacterial membrane vesicles.

Bacteria-host interaction is a common, relevant, and intriguing biological phenomena. The host reacts actively or passively to the bacteria themselves, their products, debris, and so on, through various defense systems containing the immune system, the bacteria communicate with the local or distal tissues of the host via their own surface antigens, secreted products, nucleic acids, etc., resulting in relationships of attack and defense, adaptation, symbiosis, and even collaboration. The significance of bacterial membrane vesicles (MVs) as a powerful vehicle for the crosstalk mechanism between the two is growing. In the recent decade, the emergence of MVs in microbial interactions and a variety of bacterial infections, with multiple adhesions to host tissues, cell invasion and evasion of host defense mechanisms, have brought MVs to the forefront of bacterial pathogenesis research. Whereas MVs are a complex combination of molecules not yet fully understood, research into its effects, targeting and pathogenic components will advance its understanding and utilization. This review will summarize structural, extraction and penetration information on several classes of MVs and emphasize the role of MVs in transport and immune response activation. Finally, the potential of MVs as a therapeutic method will be highlighted, as will future research prospects.

The tree shrew as a new animal model for the study of periodontitis.

AIM: Periodontitis is an inflammatory, infectious disease of polymicrobial origin that can damage tooth-supporting bone and tissue. Tree shrews, evolutionarily closer to humans than commonly used rodent models, have been increasingly used as biomedical models. However, a tree shrew periodontitis model has not yet been established. MATERIALS AND METHODS: Periodontitis was induced in male tree shrews/Sprague-Dawley rats by nylon thread ligature placement around the lower first molars. Thereafter, morphometric and histological analyses were performed. The distance from the cemento-enamel junction to the alveolar bone crest was measured using micro-computed tomography. Periodontal pathological tissue damage, inflammation and osteoclastogenesis were assessed using haematoxylin and eosin staining and quantitative immunohistochemistry, respectively. RESULTS: Post-operatively, gingival swelling, redness and spontaneous bleeding were observed in tree shrews but not in rats. After peaking, bone resorption decreased gradually until plateauing in tree shrews. Contrastingly, rapid and near-complete bone loss was observed in rats. Inflammatory infiltrates were observed 1 week post operation in both models. However, only the tree shrew model transitioned from acute to chronic inflammation. CONCLUSIONS: Our study revealed that a ligature-induced tree shrew model of periodontitis partly reproduced the pathological features of human periodontitis and provided theoretical support for using tree shrews as a potential model for human periodontitis.

Analysis of mRNA-miRNA interaction network reveals the role of CAFs-derived exosomes in the immune regulation of oral squamous cell carcinoma.

BACKGROUND: Cancer-associated fibroblasts (CAFs) have significant tumor regulatory functions, and CAFs-derived exosomes (CAFs-Exo) released from CAFs play an important role in the progression of oral squamous cell carcinoma (OSCC). However, a lack of comprehensive molecular biological analysis leaves the regulatory mechanisms of CAFs-Exo in OSCC unclear. METHODS: We used platelet derived growth factor-BB (PDGF-BB) to induce the transformation of human oral mucosa fibroblast (hOMF) into CAFs, and extracted exosomes from the supernatant of CAFs and hOMF. We validated the effect of CAFs-Exo on tumor progression by exosomes co-culture with Cal-27 and tumor-forming in nude mice. The cellular and exosomal transcriptomes were sequenced, and immune regulatory genes were screened and validated using mRNA-miRNA interaction network analysis in combination with publicly available databases. RESULTS: The results showed that CAFs-Exo had a stronger ability to promote OSCC proliferation and was associated with immunosuppression. We discovered that the presence of immune-related genes in CAFs-Exo may regulate the expression of PIGR, CD81, UACA, and PTTG1IP in Cal-27 by analyzing CAFs-Exo sequencing data and publicly available TCGA data. This may account for the ability of CAFs-Exo to exert immunomodulation and promote OSCC proliferation. CONCLUSIONS: CAFs-Exo was found to be involved in tumor immune regulation through hsa-miR-139-5p, ACTR2 and EIF6, while PIGR, CD81, UACA and PTTG1IP may be potentially effective targets for the treatment of OSCC in the future.

Targeting NLRP3 Inflammasome Alleviates Synovitis by Reducing Pyroptosis in Rats with Experimental Temporomandibular Joint Osteoarthritis.

The mechanism of temporomandibular joint osteoarthritis (TMJOA), which leads to the final erosion of cartilage and subchondral bone, has been widely demonstrated, but still not clearly elucidated. Many studies have pointed that NLRP3-mediated inflammation played a vital role in degenerative diseases. However, its interaction with synovitis of TMJOA has remained poorly investigated. In our study, we explored the role of NLRP3 inflammasome in TMJOA synovitis and the therapeutic potential of caspase-1 and NLRP3 inhibitors. By establishing a rat TMJOA model, we found that NLRP3 was upregulated in synovial tissue of TMJOA. It was involved in the progress of a programmed cell death called pyroptosis, which was caspase-1 dependent and ultimately triggered inflammatory mediator interleukin IL-1ß release. Treatment with Ac-YVAD-cmk and MCC950, inhibitors targeting caspase-1 and NLRP3, respectively, significantly suppressed pyroptosis in TMJOA synovial tissue. Then, a macrophage- and fibroblast-like synoviocyte (FLS) cocultured model further verified the above results. Macrophage somehow promoted FLS pyroptosis in this study. Our results suggested that the NLRP3 inflammasome-mediated pyroptosis participated in synovial inflammation of TMJOA. Interfering with the progress could be a potential option for controlling TMJOA development.

Comparative study of dedifferentiated fat cell and adipose-derived stromal cell sheets for periodontal tissue regeneration: In vivo and in vitro evidence.

AIM: To compare the efficacy of adipocyte-derived dedifferentiated fat (DFAT) cell and adipose-derived stromal cell (ADSC) sheets for regenerative treatment of intra-bony periodontal defects. MATERIALS AND METHODS: DFAT cells were obtained using the ceiling culture method and were compared with ADSCs using Cell Counting Kit-8, colony formation assay, surface antigen identification, and multilineage differentiation assays. DFAT and ADSC sheets were prepared in a cell sheet culture medium. The biological characteristics of DFAT cell and ADSC sheets were compared using haematoxylin and eosin staining, quantitative reverse transcription polymerase chain reaction, and immunofluorescence staining. Micro-computed tomography and histological staining were used to compare the effects of the two cell sheets on the repair of periodontal intra-bony defects in rats. RESULTS: DFAT cells and ADSCs demonstrated mesenchymal stem cell characteristics. Both cell types were CD29-, CD90-, and CD146-positive and CD31-, CD34-, and CD45-negative. DFAT cells and ADSCs exhibited similar osteogenic and adipogenic differentiation capabilities and colony formation ability. DFAT cells displayed stronger proliferation capabilities compared with ADSCs. Compared with the ADSC sheets, DFAT cell sheets exhibited a higher expression of periodontal-related genes and proteins and greater ability to regenerate periodontal tissue. CONCLUSIONS: Our findings suggest that DFAT cell sheets are an ideal seed cell source and form of cell delivery for periodontal intra-bony defects.

Hypoxia-inducible factor expression is related to apoptosis and cartilage degradation in temporomandibular joint osteoarthritis.

BACKGROUND: It remains unclear etiology of cartilaginous tissues in osteoarthritis (OA) lesions. In this study, we hypothesized the accumulation of hypoxia-inducible factor (HIF) and activated apoptosis relate to condylar cartilage degeneration in vivo. METHODS: Malocclusion stress was applied for 2 weeks, 4 weeks and 8 weeks to induce an OA-like lesion animal model in rats. Histological analysis was performed by H&E staining and Safranin O/fast green staining. The expression levels of protein in condylar cartilage were examined by immunostaining to evaluate cartilage degeneration. RESULTS: We found apparent histological phenotypes associated with degeneration in the occlusion disorder (OD) stress group. The OD group at 4 weeks and 8 weeks had obviously reduced expression of Aggrecan (Acan) and type II collagen (Col II) in cartilage. In contrast, the OD groups had higher levels of ADAM metallopeptidase with thrombospondin type 5 (ADAMTS5) and matrix metallopeptidase 13 (MMP13) in the condylar cartilage than the control group. Moreover, the OD group cartilage had prominent degenerative changes with reduced levels of hypoxia inducible factor 1 alpha (HIF1α) and increased levels of hypoxia inducible factor 2 alpha (HIF2α) and the apoptosis factor Caspase3 in condylar cartilage at 8 weeks. CONCLUSION: Thus, abnormal hypoxic conditions inducing Occlusion disorder stress results in cartilage degeneration. opposite expression patterns of HIF1α and HIF2α could be involved in the pathogenesis of condylar cartilage degeneration and chondrocyte apoptosis. HIF2α may provide a potential negative feedback mechanism for HIF1α during cartilage damage.

A new species of the idiocerine leafhopper genus Chinaocerus Zhang amp; Li (Hemiptera: Cicadellidae) from northwest China, with a checklist and key to species.

A new leafhopper species, Chinaocerus dentatus Zhang sp. nov., is described and illustrated from Qinghai and Gansu Provinces, China. Specimens were collected from willow (Salix sp.). A checklist and key to species of the genus are provided.

Small extracellular vesicles from dental follicle stem cells provide biochemical cues for periodontal tissue regeneration.

BACKGROUND: Treatments based on stem cell-derived small extracellular vesicles (sEVs) have been explored as an alternative to stem cell transplantation-based therapies in periodontal regeneration. Dental follicle stem cells (DFSCs) have shown great potential for regenerative medicine applications. However, it is unclear whether sEVs derived from DFSCs (DFSCs-sEVs) could be used in periodontal regeneration. This study investigates whether DFSCs-sEVs could regenerate damaged periodontal tissue and the potential underlying mechanism. METHODS: DFSCs-sEVs were isolated and identified, and periodontal ligament stem cells (PDLSCs) were cocultured with the isolated sEVs. The effect of DFSCs-sEVs on the biological behaviour of PDLSCs was examined using EdU assay, CCK-8 assay, cell cycle analysis, wound healing, alizarin red staining, qRT-PCR, and western blot analysis. RNA sequencing and functional enrichment analysis were used to detect the signal pathway involved in the effect of DFSCs-sEVs on PDLSCs. PDLSCs were pretreated with ERK1/2 or p38 MAPK inhibitors to investigate the possible involvement of the ERK1/2 and p38 MAPK pathways. Additionally, DFSCs-sEVs were combined with collagen sponges and transplanted into the periodontal defects in SD rats, and then, pathological changes in periodontal tissue were examined using haematoxylin and eosin (HE) staining and micro-CT. RESULTS: PDLSCs could internalize DFSCs-sEVs, thereby enhancing the proliferation assessed using EdU assay, CCK-8 assay and cell cycle analysis. DFSCs-sEVs significantly enhanced the migration of PDLSCs. DFSCs-sEVs promoted osteogenic differentiation of PDLSCs, showing deep Alizarin red staining, upregulated osteogenic genes (RUNX2, BSP, COL1), and upregulated protein expression (RUNX2, BSP, COL1, ALP). We found that p38 MAPK signalling was activated via phosphorylation. Inhibition of this signalling pathway with a specific inhibitor (SB202190) partially weakened the enhanced proliferation. After DFSCs-sEVs transplantation, new periodontal ligament-like structures and bone formation were observed in the damaged periodontal area in rats. Labelled DFSCs-sEVs were observed in the newly formed periodontal ligament and soft tissue of the defect area. CONCLUSIONS: Our study demonstrated that DFSCs-sEVs promoted periodontal tissue regeneration by promoting the proliferation, migration, and osteogenic differentiation of PDLSCs. The effect of DFSCs-sEVs in promoting PDLSCs proliferation may be partially attributed to the activation of p38 MAPK signalling pathway. DFSCs-sEVs provide us with a novel strategy for periodontal regeneration in the future.

PRMT1 promotes extracellular matrix degradation and apoptosis of chondrocytes in temporomandibular joint osteoarthritis via the AKT/FOXO1 signaling pathway.

Temporomandibular joint osteoarthritis (TMJOA) is a chronic degenerative joint disease characterized by extracellular matrix (ECM) degradation and chondrocyte apoptosis. The aim of this study was to investigate the role of PRMT1 in TMJOA pathogenesis and its underlying molecular mechanism. Compared to the control group, PRMT1 was highly expressed in IL-1ß-treated chondrocytes and articular cartilage following MIA injection into rat TMJs. Furthermore, knocking down PRMT1 considerably inhibited ECM degradation and apoptosis induced by IL-1ß. Mechanistic analyses further revealed that PRMT1 knockdown activated the PI3K/AKT signaling pathway and prevented FOXO1 from translocating to the nucleus. Moreover, an inhibitor of AKT (LY294002) rescued the effect of PRMT1 knockdown on IL-1ß-induced ECM degradation and apoptosis, and AMI-1, a selective inhibitor of PRMT1, inhibited PRMT1 expression and reversed the pathological progress of TMJOA. Thus, our findings suggest that PRMT1 plays an essential role in ECM degradation and chondrocyte apoptosis in TMJOA via the AKT/FOXO1 signaling pathway.

Xenogeneic dentin matrix as a scaffold for biomineralization and induced odontogenesis.

Commonly recognized mechanisms of the xenogeneic-extracellular matrix-based regenerative medicine include timely degradation, release of bioactive molecules, induced differentiation of stem cells, and well-controlled inflammation. This process is most feasible for stromal tissue reconstruction, yet unsuitable for non-degradable scaffold and prefabricated-shaped tissue regeneration, like odontogenesis. Treated dentin matrix (TDM) has been identified as a bioactive scaffold for dentin regeneration. This study explored xenogeneic porcine TDM (pTDM) for induced odontogenesis. The biological characteristics of pTDM were compared with human TDM (hTDM). To investigate its bioinductive capacities on allogeneic dental follicle cells (DFCs) in the inflammation microenvironment, pTDM populated with human DFCs were co-cultured with human peripheral blood mononuclear cells (hPBMCs), and pTDM populated with rat DFCs were transplanted into rat subcutaneous model. The results showed pTDM possessed similar mineral phases and bioactive molecules with hTDM. hDFCs, under the induction of pTDM and hTDM, expressed similar col-I, osteopontin and alkaline phosphatase (ALP) (all expressed by odontoblasts). Whereas, the expression of col-I, dentin matrix protein-1 (DMP-1) and bone sialoprotein (BSP) were down-regulated when cocultured with hPBMCs. The xenogeneic implants inevitably initiated Th1 inflammation (up-regulated CD8, TNF-α, IL-1ß, etc)in vivo. However, the biomineralization of pre-dentin and cementum were still processed, and collagen fibrils, odontoblast-like cells, fibroblasts contributed to odontogenesis. Although partially absorbed at 3 weeks, the implants were positively expressed odontogenesis-related-proteins like col-I and DMP-1. Taken together, xenogeneic TDM conserved ultrastructure and molecules for introducing allogeneic DFCs to odontogenic differentiation, and promoting odontogenesis and biomineralizationin vivo. Yet effective immunomodulation methods warrant further explorations.

Recruited CD68+CD206+ macrophages orchestrate graft immune tolerance to prompt xenogeneic-dentin matrix-based tooth root regeneration.

Successful regenerative medicine strategies of xenogeneic extracellular matrix need a synergistic balance among inflammation, fibrosis, and remodeling process. Adaptive macrophage subsets have been identified to modulate inflammation and orchestrate the repair of neighboring parenchymal tissues. This study fabricated PPARγ-primed CD68+CD206+ M2 phenotype (M2γ), and firstly verified their anti-inflammatory and tissue-regenerating roles in xenogeneic bioengineered organ regeneration. Our results showed that Th1-type CD3+CD8+ T cell response to xenogeneic-dentin matrix-based bioengineered root complex (xeno-complex) was significantly inhibited by M2γ macrophage in vitro. PPARγ activation also timely recruited CD68+CD206+ tissue macrophage polarization to xeno-complex in vivo. These subsets alleviated proinflammatory cytokines (TNF-α, IFN-γ) at the inflammation site and decreased CD3+CD8+ T lymphocytes in the periphery system. When translated to an orthotopic nonhuman primate model, PPARγ-primed M2 macrophages immunosuppressed IL-1ß, IL-6, TNF-α, MMPs to enable xeno-complex to effectively escape immune-mediated rejection and initiate graft-host synergistic integrity. These collective activities promoted the differentiation of odontoblast-like and periodontal-like cells to guide pulp-dentin and cementum-PDLs-bone regeneration and rescued partially injured odontogenesis such as DSPP and periostin expression. Finally, the regenerated root showed structure-biomechanical and functional equivalency to the native tooth. The timely conversion of M1-to-M2 macrophage mainly orchestrated odontogenesis, fibrogenesis, and osteogenesis, which represents a potential modulator for intact parenchymal-stromal tissue regeneration of targeted organs.

Corrigendum to "N-Acetyl Cysteine as a Novel Polymethyl Methacrylate Resin Component: Protection against Cell Apoptosis and Genotoxicity".

[This corrects the article DOI: 10.1155/2019/1301736.].

N-Acetyl Cysteine as a Novel Polymethyl Methacrylate Resin Component: Protection against Cell Apoptosis and Genotoxicity.

The present study investigated the antiapoptotic and antigenotoxic capabilities of N-acetyl cysteine- (NAC-) containing polymethyl methacrylate (PMMA) resin. An in vitro Transwell insert model was used to mimic the clinical provisional restorations placed on vital teeth. Various parameters associated with cell apoptosis and genotoxicity were investigated to obtain a deeper insight into the underlying mechanisms. The exposure of human dental pulp cell (hDPC) cultures to the PMMA resin (Unifast Trad™) resulted in a rapid increase in reactive oxygen species (ROS) level beginning at 1 h, which was followed by time-dependent cell detachment and overt death. The formation of γ-H2AX and cell cycle G1 phase arrest indicated that oxidative DNA damage occurred as a result of the interactions between DNA bases and ROS, beyond the capacities of cellular redox regulation. Such oxidative DNA damage triggers the activation of p53 via the ataxia telangiectasia mutated (ATM) signaling pathway and the induction of intrinsic mitochondrial apoptosis. Oxidative stress, cell apoptosis, and DNA damage induced by the PMMA resin were recovered to almost the level of untreated controls by the incorporation of NAC. The results indicate that the PMMA resin induced the intrinsic mitochondrial apoptosis as a consequence of p53 activation via the ATM pathway in response to oxidative DNA damage. More importantly, the incorporation of NAC as a novel component into the Unifast Trad™ PMMA resin offers protective effects against cell apoptosis and genotoxicity. This procedure represents a beneficial strategy for developing more biocompatible PMMA-based resin materials.

Comprehensive analysis of long noncoding RNAs and mRNAs expression profiles and functional networks during chondrogenic differentiation of murine ATDC5 cells.

Chondrogenic differentiation is a coordinated biological process orchestrated by various cell signaling pathways, involving complex pathways regulated at both transcriptional and post-transcriptional levels. Long noncoding RNAs (lncRNAs) are emerging as important regulators in the modulation of multiple cell processes. However, the potential roles of lncRNAs and their regulatory mechanisms in chondrogenic differentiation remain largely unclear. In this study, microarray was performed to detect the expression profiles of lncRNAs and messenger RNAs (mRNAs) during chondrogenic differentiation of murine chondrogenic cell line ATDC5. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed to explore their functions. Coding-noncoding co-expression (CNC) and competing endogenous RNA (ceRNA) networks were also constructed with bioinformatics methods. The results revealed that 1009 lncRNAs and 1206 mRNAs were differentially regulated during chondrogenic differentiation. GO and KEGG pathway analysis indicated that the principal functions of the transcripts were associated with system development and extracellular matrix-receptor interaction, TGF-ß signaling, and PI3K-Akt signaling pathways. The CNC network showed that lncRNA AK136902 was positively correlated with prostaglandin F receptor (FP). The ceRNA network covered 3 lncRNAs, 121 miRNAs and 241 edges. The upregulated lncRNA AK136902, AK016344, and ENSMUST00000180767 might promote chondrogenic differentiation by acting as ceRNAs. Knockdown of lncRNA AK136902 could inhibit the mRNA expression of FP and other chondrogenic related genes, including Aggrecan and Col2a1 during chondrogenic differentiation. Our results provide a new perspective on the modulation of lncRNAs during chondrogenic differentiation.

Treated dentin matrix particles combined with dental follicle cell sheet stimulate periodontal regeneration.

OBJECTIVE: Periodontal tissue engineering is an attractive approach for restoring periodontal-supporting structures and functions. However, complete periodontal regeneration has not been accomplished. Previous studies demonstrated the feasibility of using cell sheets and treated dentin matrix (TDM) to regenerate bio-roots. METHODS: In this study, we regenerated periodontal tissue using cell sheets combined with TDM particles (TDMPs). Human dental follicle cells (hDFCs) were isolated and characterized. Human dental follicle cells sheets (hDFCSs) and human TDMPs (hTDMP) were fabricated and characterized. The osteogenic effect of hTDMP was evaluated on human bone marrow stromal cells (hBMSCs) in vitro and a rat calvarial bone defect in vivo. Real-time PCR, western blotting, radiograph analysis, and histological analysis were performed to evaluate the periodontal induction capacity of hTDMP. One-wall periodontal intrabony defects were prepared to evaluate the periodontal regeneration capacity of TDMP/DFCSs on beagle dogs. RESULTS: The results showed that hDFCs were mesenchymal stem cells. hTDMP promoted the proliferation and osteogenic differentiation of hBMSCs. New bone formation was observed in the rat calvarial bone defect zone in both the hTDMP and hydroxyapatite/ß-tricalcium phosphate groups. Periodontal-like tissues showed better regeneration in the canine TDMP+DFCS group than in the other groups. SIGNIFICANCE: These results demonstrate the potential of using TDMP/DFCSs in periodontal regeneration.