Novel self-setting cements based on tricalcium silicate/(ß-tricalcium phosphate/monocalcium phosphate anhydrous)/hydroxypropyl methylcellulose: From hydration mechanism to biological evaluations.

Despite the clinical success of tricalcium silicate (TCS)-based materials in endodontics, the inferior handling characteristic, poor anti-washout property and slow setting kinetics hindered their wider applications. To solve these problems, an injectable fast-setting TCS/ß-tricalcium phosphate/monocalcium phosphate anhydrous (ß-TCP/MCPA) cement was developed for the first time by incorporation of hydroxypropyl methylcellulose (HPMC) and ß-TCP/MCPA. The physical-chemical characterization (setting time, anti-washout property, injectability, compressive strength, apatite mineralization and sealing property) of TCS/(ß-TCP/MCPA) were conducted. Its hydration mechanism was also investigated. Furthermore, the cytocompatibility and osteogenic/odontogenic differentiation of stem cells isolated from human exfoliated deciduous teeth (SHED) treated with TCS/ß-TCP/MCPA were studied. The results showed that HPMC could provide TCS with good anti-washout ability and injectability but slow hydration process. However, ß-TCP/MCPA effectively enhanced anti-washout characteristics and reduced setting time due to faster hydration kinetics. TCS/(ß-TCP/MCPA) obtained around 90 % of injection rate and high compressive strength whereas excessive additions of ß-TCP/MCPA compromised its injectability and compressive strength. TCS/(ß-TCP/MCPA) can induce apatite deposition and form a tight marginal sealing at the dentin-cement interface. Additionally, TCS/(ß-TCP/MCPA) showed good biocompatibility and promoted osteo/odontogenic differentiation of SHED. In general, our results indicated that TCS/(ß-TCP/MCPA) may be particularly promising as an injectable bioactive cements for endodontic treatment.

Bone Marrow Mesenchymal Stem Cell-Derived Exosomal KLF4 Alleviated Ischemic Stroke Through Inhibiting N6-Methyladenosine Modification Level of Drp1 by Targeting lncRNA-ZFAS1.

Ischemic stroke has become a serious public health problem that causes high rates of death and disability. Bone marrow mesenchymal stem cell (BMSC)-derived exosomes have shown promising therapeutic results in IS, while the underlying mechanisms need further investigation. Cell and mice models were established through oxygen-glucose deprivation/reoxygenation (OGD/R) treatment and middle cerebral artery occlusion (MCAO)/reperfusion. Exosomes were isolated from BMSCs. Related gene and protein expression was measured by qRT-PCR, Western blotting, and immunofluorescence analysis. The biological functions of treated cells and tissues were analyzed by MTT, ELISA, JC-1, flow cytometry, TTC staining, or TUNEL staining. The interaction of KLF4/lncRNA-ZFAS1 promoter and lncRNA-ZFAS1/FTO was measured by ChIP, dual-luciferase reporter, or RIP assays. The m6A levels of Drp1 were measured by MeRIP-PCR. Mitochondrial staining and transmission electron microscopy (TEM) were used to evaluate the mitochondrial morphology in N2a cells and brain tissues. BMSC-derived exosomes increased the viability of neuronal cells treated with OGD/R while decreasing LDH release, oxidative stress, mitochondrial injury, and apoptosis. Furthermore, these effects were abolished by knockdown of exosomal KLF4. KLF4 increased lncRNA-ZFAS1 through binding to its promoter. LncRNA-ZFAS1 overexpression suppressed the m6A levels of Drp1 and reversed the promoting effect of exosomal KLF4 silencing on mitochondrial injury and the imbalance of mitochondrial dynamics by targeting FTO. Exosomal KLF4 alleviated the infarct area, neuronal injury, and apoptosis in MCAO mice through lncRNA-ZFAS1/FTO/Drp1 axis. BMSC-derived exosomal KLF4 promoted lncRNA-ZFAS1 expression to repress Drp1 m6A modification by targeting FTO, thus reducing mitochondrial dysfunction and alleviating neuronal injury in ischemic stroke.

Exosomal ZEB1 Derived from Neural Stem Cells Reduces Inflammation Injury in OGD/R-Treated Microglia via the GPR30-TLR4-NF-κB Axis.

Ischemic stroke (IS) is the most common type of stroke and the second leading cause of death overall. Neural stem cells play protective roles in IS, but the underlying mechanism remains to be determined. Neural stem cells (NSC) were obtained from the fetal brain tissue of C57BL/6J mice. NSC-derived exosomes (NSC-Exos) were identified in the conditioned medium. Internalization of NSC-Exos was analyzed by fluorescence microscopy. In vitro microglia ischemic stroke injury model was induced using oxygen glucose deprivation/re-oxygenation (OGD/R) method. Cell viability and inflammation were analyzed by MTT, qPCR, ELISA and Western blotting assay. Interaction between ZEB1 and the promoter of GPR30 was verified by luciferase assay and chromatin immunoprecipitation. NSC-Exos prevented OGD/R-mediated inhibition of cell survival and the production of inflammatory cytokines in microglia cells. NSC-Exos increased ZEB1 expression in OGD/R-treated microglia. Down-regulation of ZEB1 expression in NSC-Exos abolished NSC-Exos' protective effects on OGD/R-treated microglia. ZEB1 bound to the promoter region of GPR30 and promoted its expression. Inhibiting GPR30 reversed NSC-Exos effects on cell viability and inflammation injury in OGD/R-treated microglia. Our study demonstrated that NSC exerted cytoprotective roles through release of exosomal ZEB1,which transcriptionally upregulated GPR30 expression, resulting in a reduction in TLR4/NF-κB pathway-induced inflammation. These findings shed light on NSC-Exos' cytoprotective mechanism and highlighted its potential application in the treatment of IS.

BMSC-Derived Exosomal Egr2 Ameliorates Ischemic Stroke by Directly Upregulating SIRT6 to Suppress Notch Signaling.

Exosomes generated by BMSCs contribute to functional recovery in ischemic stroke. However, the regulatory mechanism is largely unknown. Exosomes were isolated from BMSCs. Tube formation, MTT, TUNEL, and flow cytometry assays were applied to examine cell angiogenesis, viability, and apoptosis. Protein and DNA interaction was evaluated by ChIP and luciferase assays. LDH release into the culture medium was examined. Infarction area was evaluated by TTC staining. Immunofluorescence staining was applied to examine CD31 expression. A mouse model of MCAO/R was established. BMSC-derived exosomes attenuated neuronal cell damage and facilitated angiogenesis of brain endothelial cells in response to OGD/R, but these effects were abolished by the knockdown of Egr2. Egr2 directly bound to the promoter of SIRT6 to promote its expression. The incompetency of Egr2-silencing exosomes was reversed by overexpression of SIRT6. Furthermore, SIRT6 inhibited Notch signaling via suppressing Notch1. Overexpression of SIRT6 and inhibition of Notch signaling improved cell injury and angiogenesis in OGD/R-treated cells. BMSC-derived exosomal Egr2 ameliorated MCAO/R-induced brain damage via upregulating SIRT6 to suppress Notch signaling in mice. BMSC-derived exosomes ameliorate OGD/R-induced injury and MCAO/R-caused cerebral damage in mice by delivering Egr2 to promote SIRT6 expression and subsequently suppress Notch signaling. Our study provides a potential exosome-based therapy for ischemic stroke.

LncRNA CEBPA-AS1 knockdown prevents neuronal apoptosis against oxygen glucose deprivation/reoxygenation by regulating the miR-455/GPER1 axis.

Ischemic stroke (IS) is a common nervous system disease, which is a major cause of disability and death in the world. In present study, we demonstrated a regulatory mechanism of CCAAT/enhancer binding protein-alpha antisense 1 (CEBPA-AS1) in oxygen glucose deprivation/reoxygenation (OGD/R)-induced SH-SY5Y cells, with a focus on neuronal apoptosis. CEBPA-AS1, miR-455, and GPER1 expressions were evaluated by using qRT-PCR and Western blotting. The binding relationship among CEBPA-AS1, miR-455, and GPER1 was determined by a dual luciferase reporter assay. Neuronal viability and apoptosis were examined using MTT and flow cytometry assays, followed by determination of apoptosis-related factors (caspase 3, caspase 8, caspase 9, Bax, and Bcl-2). CEBPA-AS1 and GPER1 levels were upregulated, and miR-455 level was downregulated in the cell model of OGD/R induced. CEBPA-AS1 knockdown increased SH-SY5Y viability and reduced OGD/R-induced apoptosis. CEBPA-AS1 could act as a sponge of miR-455, and CEBPA-AS1 knockdown was found to elevate miR-455 expression. miR-455 overexpression also promoted SH-SY5Y cell viability and rescued them from OGD/R-induced apoptosis by binding to GPER1. GPER1 overexpression or miR-455 inhibition reversed the anti-apoptotic effect of CEBPA-AS1 knockdown. These findings suggest a regulatory network of CEBPA-AS1/miR-455/GPER1 that mediates neuronal cell apoptosis in the OGD model, providing a better understanding of pathogenic mechanisms after IS.

Genetic polymorphisms in the ALDH2 gene and the risk of ischemic stroke in a Chinese han population.

BACKGROUND: Previous studies have shown that aldehyde dehydrogenase 2 (ALDH2) plays a role in ischemic stroke progression. In recent years, the activation of the ALDH2 pathway have been reported serving as a useful index in the identification of stroke-prone participants, and the ALDH2 pathway may be a potential target for the therapeutic intervention in ischemic stroke. MATERIALS AND METHODS: We evaluated six tagging single-nucleotide polymorphisms (SNPs) of the ALDH2 gene in a case-control study from Hainan of China (488 cases, 503 controls). We used SPSS version 17.0 statistical software, Excel software and other analysis software to explore associations between SNPs and the risk of ischemic stroke various genetic models (additive, dominant, and recessive). RESULTS: Through statistical analysis, we found that ALDH2 rs886205 [odds ratio (OR) = 6.39; 95% confidence interval (CI) = 1.19-34.38; p = 0.03] and rs7296651 (OR = 9.29; 95% CI = 1.37-63.21; p = 0.02) were associated with increased risk of ischemic stroke in recessive model analysis. In addition, we established that the "AA" genotype (OR = 5.99; 95% CI = 1.11-32.23; p = 0.037) for rs886205 and the "AA" genotype (OR = 8.93; 95% CI = 1.31-60.78; p = 0.025) for rs7296651 were associated with increased ischemic stroke risk. CONCLUSIONS: Our results provide evidence that variants of ALDH2 gene polymorphisms influence the risk of developing ischemic stroke in Han Chinese population.

Association analysis of APO gene polymorphisms with ischemic stroke risk: a case-control study in a Chinese Han population.

This study aimed to assess the association of APO gene polymorphisms and ischemic stroke risk in a Chinese Han population. In this case-control study, we genotyped 14 single nucleotide polymorphisms (SNPs) in 3 APO genes in 488 cases and 503 controls using Sequenom Mass-ARRAY technology and evaluated their association with ischemic stroke using the χ2 and genetic model analysis. In the allelic model analysis, we determined three SNPs were significantly associated with ischemic stroke: rs693 with a p value of 0.042 (OR = 1.406; 95%CI = 1.011-1.956), rs651821 with a p value of 0.007 (OR = 0.760; 95%CI = 0.622-0.929) and rs662799 with a p value of 0.006 (OR = 0.755; 95%CI = 0.618-0.923). In the genetic model analysis, we found the minor allele "A" of rs693 was associated with an increased ischemic stroke risk in the additive model and dominant model. The minor allele "C" of rs651821 was associated with a decreased ischemic stroke risk in the additive model. The minor allele "G" of rs662799 was associated with a decreased ischemic stroke risk in the additive model. Additionally, strong linkage was found in 3 blocks constituted by rs1042034, rs676210, rs693, rs673548 in APOB; rs3791981, rs679899 in APOB; and rs651821, rs662799, rs17120035 in APOA5. Our data suggested that gene polymorphisms in the APO genes may exert influences ischemic stroke susceptibility in a Chinese Han population.

Long non-coding RNAs: potential molecular biomarkers for gliomas diagnosis and prognosis.

The current grade classification system of gliomas is based on the histopathological features of these tumors and has great significance in defining groups of patients for clinical assessment. However, this classification system is also associated with a number of limitations, and as such, additional clinical assessment criteria are required. Long non-coding RNAs (lncRNAs) play a critical role in cellular functions and are currently regarded as potential biomarkers for glioma diagnosis and prognosis. Therefore, the molecular classification of glioma based on lncRNA expression may provide additional information to assist in the systematic identification of glioma. In the present paper, we review the emerging evidence indicating that specific lncRNAs may have the potential for use as key novel biomarkers and thus provide a powerful tool for the systematic diagnosis of glioma.