81 research outputs found
Crucial role of vinexin for keratinocyte migration in vitro and epidermal wound healing in vivo.
In the process of tissue injury and repair, epithelial cells rapidly migrate and form epithelial sheets. Vinexin is a cytoplasmic molecule of the integrin-containing cell adhesion complex localized at focal contacts in vitro. Here, we investigated the roles of vinexin in keratinocyte migration in vitro and wound healing in vivo. Vinexin knockdown using siRNA delayed migration of both HaCaT human keratinocytes and A431 epidermoid carcinoma cells in scratch assay but did not affect cell proliferation. Induction of cell migration by scratching the confluent monolayer culture of these cells activated both EGFR and ERK, and their inhibitors AG1478 and U0126 substantially suppressed scratch-induced keratinocyte migration. Vinexin knockdown in these cells inhibited the scratch-induced activation of EGFR, but not that of ERK, suggesting that vinexin promotes cell migration via activation of EGFR. We further generated vinexin (-/-) mice and isolated their keratinocytes. They similarly showed slow migration in scratch assay. Furthermore, vinexin (-/-) mice exhibited a delay in cutaneous wound healing in both the back skin and tail without affecting the proliferation of keratinocytes. Together, these results strongly suggest a crucial role of vinexin in keratinocyte migration in vitro and cutaneous wound healing in vivo
Exploring the capability of mayenite (12CaO·7Al₂O₃) as hydrogen storage material
We utilized nanoporous mayenite (12CaO·7Al₂O₃), a cost-effective material, in the hydride state (H⁻) to explore the possibility of its use for hydrogen storage and transportation. Hydrogen desorption occurs by a simple reaction of mayenite with water, and the nanocage structure transforms into a calcium aluminate hydrate. This reaction enables easy desorption of H⁻ ions trapped in the structure, which could allow the use of this material in future portable applications. Additionally, this material is 100% recyclable because the cage structure can be recovered by heat treatment after hydrogen desorption. The presence of hydrogen molecules as H⁻ ions was confirmed by ¹H-NMR, gas chromatography, and neutron diffraction analyses. We confirmed the hydrogen state stability inside the mayenite cage by the first-principles calculations to understand the adsorption mechanism and storage capacity and to provide a key for the use of mayenite as a portable hydrogen storage material. Further, we succeeded in introducing H⁻ directly from OH⁻ by a simple process compared with previous studies that used long treatment durations and required careful control of humidity and oxygen gas to form O₂ species before the introduction of H⁻
A toxicoproteomic study on cardioprotective effects of pre-administration of docetaxel in a mouse model of adriamycin-induced cardiotoxicity.
Studies suggest that pre-administration of docetaxel (DOC) in adriamycin (ADR)-DOC combination anticancer therapy results in stronger antitumor effects and fewer ADR-induced cardiotoxic deaths in mouse model, yet no mechanism explaining this effect has been established. The aim of this study was to identify cellular processes in mouse heart tissue affected by different ADR/DOC dosing protocols using a toxicoproteomic approach. We applied fluorogenic derivatization-liquid chromatography-tandem mass spectrometry (FD-LC-MS/MS) - which consists of fluorogenic derivatization, separation and fluorescence detection by LC, and identification by LC-tandem mass spectrometry - to the proteomic analysis of heart tissue from control, intermittent-dosing (DOC-ADR), and simultaneous-dosing (ADR&DOC) groups. In DOC-ADR group, ADR was administered 12h after DOC injection; in ADR&DOC group, both drugs were administered simultaneously; in control group, saline was administered at the same timing as ADR injection of other groups. Heart samples were isolated from all mice 1 week after the treatment. The highly reproducible and sensitive method (FD-LC-MS/MS) identified nine proteins that were differentially expressed in heart tissue of control and the two treatment groups; seven of these nine proteins participate in cellular energy production pathways, including glycolysis, the tricarboxylic acid cycle, and the mitochondrial electron transport chain. Significantly higher expression of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was observed in the DOC-ADR group, the group with the fewer cardiotoxic deaths, than in the ADR&DOC group. Therefore, GAPDH may have potential as a drug target for protective intervention and a biomarker for evaluation of the cardioprotective effects in pre-clinical studies
Immune checkpoint molecule DNAM-1/CD112 axis is a novel target for natural killer-cell therapy in acute myeloid leukemia
Acute myeloid leukemia (AML) is a hematologic malignancy that frequently relapses, even if remission can be achieved with intensive chemotherapy. One known relapse mechanism is the escape of leukemic cells from immune surveillance. Currently, there is no effective immunotherapy for AML because of the lack of specific antigens. Here, we aimed to elucidate the association between CD155 and CD112 in AML cell lines and primary AML samples and determine the therapeutic response. Briefly, we generated NK-92 cell lines (NK-92) with modified DNAX-associated molecule 1 (DNAM-1) and T-cell immunoglobulin and ITIM domain (TIGIT), which are receptors of CD155 and CD112, respectively. Analysis of 200 cases of AML indicated that the survival of patients with high expression of CD112 was shorter than that of patients with low expression. NK-92 DNAM-1 exhibited enhanced cytotoxic activity against AML cell lines and primary cells derived from patients with AML. DNAM-1 induction in NK-92 cells enhanced the expression of cytotoxicity-related genes, thus overcoming the inhibitory activity of TIGIT. Between CD155 and CD112, CD112 is an especially important target for natural killer (NK)-cell therapy of AML. Using a xenograft model, we confirmed the enhanced antitumor effect of NK-92 DNAM-1 compared with that of NK-92 alone. We also discovered that CD112 (Nectin-2), an immune checkpoint molecule belonging to the Nectin/Nectin-like family, functions as a novel target of immunotherapy. In conclusion, modification of the DNAM-1/CD112 axis in NK cells may be an effective novel immunotherapy for AML. Furthermore, our findings suggest that the levels of expression of these molecules are potential prognostic markers in AML
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