Mesenchymal stem cell-mediated tissue regeneration is a promising approach for regenerative medicine for a wide range of applications. Here we report a new population of stem cells isolated from the root apical papilla of human teeth (SCAP, stem cells from apical papilla). Using a minipig model, we transplanted both human SCAP and periodontal ligament stem cells (PDLSCs) to generate a root/periodontal complex capable of supporting a porcelain crown, resulting in normal tooth function. This work integrates a stem cell-mediated tissue regeneration strategy, engineered materials for structure, and current dental crown technologies. This hybridized tissue engineering approach led to recovery of tooth strength and appearance.

NLRP3 inflammasome is necessary for initiating acute sterile inflammation. Recent studies have demonstrated that NLRP3 inflammasome is up-regulated and mediates myocardial ischemia/reperfusion (MI/R) injury. However, the signaling pathways that lead to the activation of NLRP3 inflammasome by MI/R injury have not been fully elucidated. C57BL/6J mice were subjected to 30 min ischemia and 3 or 24 h reperfusion. The ischemic heart exhibited enhanced inflammasome activation as evidenced by increased NLRP3 expression and caspase-1 activity and increased IL-1β and IL-18 production. Intramyocardial NLRP3 siRNA injection or an intraperitoneal injection of BAY 11-7028, an inflammasome inhibitor, attenuated macrophage and neutrophil infiltration and decreased MI/R injury, as measured by cardiomyocyte apoptosis and infarct size. The ischemic heart also exhibited enhanced interaction between Txnip and NLRP3, which has been shown to be a mechanism for activating NLRP3. Intramyocardial Txnip siRNA injection also decreased infarct size and NLRP3 activation. In vitro experiments revealed that NLRP3 was expressed in cardiac microvascular endothelial cells (CMECs), but was hardly expressed in cardiomyocytes. Simulated ischemia/reperfusion (SI/R) stimulated NLRP3 inflammasome activation in CMECs, but not in cardiomyocytes. Moreover, CMECs subjected to SI/R injury increased interactions between Txnip and NLRP3. Txnip siRNA diminished NLRP3 inflammasome activation and SI/R-induced injury, as measured by LDH release and caspase-3 activity in CMECs. ROS scavenger dissociated TXNIP from NLRP3 and inhibited the activation of NLRP3 inflammasome in the CMECs. For the first time, we demonstrated that TXNIP-mediated NLRP3 inflammasome activation in CMECs was a novel mechanism of MI/R injury. Interventions that block Txnip/NLRP3 signaling to inhibit the activation of NLRP3 inflammasomes may be novel therapies for mitigating MI/R injury.

BackgroundThe success of using glycolytic inhibitors for cancer treatment relies on better understanding the roles of each frequently deregulated glycolytic genes in cancer. This report analyzed the involvement of a key glycolytic enzyme, alpha-enolase (ENO1), in tumor progression and prognosis of human glioma.MethodsENO1 expression levels were examined in glioma tissues and normal brain (NB) tissues. The molecular mechanisms of ENO1 expression and its effects on cell growth, migration and invasion were also explored by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay, Transwell chamber assay, Boyden chamber assay, Western blot and in vivo tumorigenesis in nude mice.ResultsENO1 mRNA and protein levels were upregulated in glioma tissues compared to NB. In addition, increased ENO1 was associated disease progression in glioma samples. Knocking down ENO1 expression not only significantly decreased cell proliferation, but also markedly inhibited cell migration and invasion as well as in vivo tumorigenesis. Mechanistic analyses revealed that Cyclin D1, Cyclin E1, pRb, and NF-κB were downregulated after stable ENO1 knockdown in glioma U251 and U87 cells. Conversely, knockdown of ENO1 resulted in restoration of E-cadherin expression and suppression of mesenchymal cell markers, such as Vimentin, Snail, N-Cadherin, β-Catenin and Slug. Furthermore, ENO1 suppression inactivated PI3K/Akt pathway regulating the cell growth and epithelial-mesenchymal transition (EMT) progression.ConclusionOverexpression of ENO1 is associated with glioma progression. Knockdown of ENO1 expression led to suppressed cell growth, migration and invasion progression by inactivating the PI3K/Akt pathway in glioma cells.