Investigation of the Micromechanical Behavior of a Ti68Nb7Ta3Zr4Mo18 (at.%) High-Entropy Alloy.

Intense research efforts are focused on the development of advanced high-entropy alloys intended for premium aerospace components and other applications, where high strength and good formability are crucial. The mechanical properties of these alloys are closely related to the phase transformation, dislocation evolution, and grain size, and these factors are affected by the deformation temperature. The response of the retained austenite to strain-induced martensitic transformation at various temperatures was studied in an advanced Ti68Nb7Ta3Zr4Mo18 (at.%) high-entropy alloy via molecular dynamics simulation. It was found that the Ti68Nb7Ta3Zr4Mo18 alloy changes from a single crystal to a polycrystal during the tensile process, and the transition of the Ti68Nb7Ta3Zr4Mo18 (at.%) high-entropy alloy from the BCC phase to the FCC phase occurs. At high temperatures and low strain rates, grain boundary slip is the main deformation mechanism, and at low temperatures and high strain rates, dislocation slip replaces grain boundary slip as the dominant deformation mechanism, which improves the strength of the alloy. Moreover, when the grain size is too small, the strength of the alloy decreases, which does not satisfy the fine grain strengthening theory and shows an inverse Hall-Petch relationship. This study offers a new compositional window for the additive manufactured lightweight high-strength material categories for various applications including the aerospace industry.

Cell shape-based chemical screening reveals an epigenetic network mediated by focal adhesions.

Adapter proteins CRK and CRKL participate in a variety of signaling pathways, including cell adhesion, and fate regulation of mammalian cells. However, the molecular functions of CRK/CRKL in epigenetic regulation remain largely unknown. Here, we developed a pipeline to evaluate cell morphology using high-content image analysis combined with chemical screening of kinase and epigenetic modulators. We found that CRK/CRKL modulates gene regulatory networks associated with cell morphology through epigenetic alteration in mouse embryonic fibroblasts. Integrated epigenome and transcriptome analyses revealed that CRK/CRKL is involved in super-enhancer activity and upregulation of Cdt1, Rin1, and Spp1 expression for the regulation of cell morphology. Screening of a library of 80 epigenetic inhibitors showed that histone H3 modifiers, euchromatic histone methyltransferase 2 and mitogen- and stress-activated kinase 1, may be important for CRK/CRKL-mediated morphological changes. Taken together, our results indicate that CRK/CRKL plays a critical role in gene regulatory networks through epigenetic modification. DATABASES: Chromatin immunoprecipitation sequencing and RNA sequencing data were deposited in the DNA Data Bank of Japan under DRA011080 and DRA011081 accession numbers, respectively.

A Computational Framework for Prediction and Analysis of Cancer Signaling Dynamics from RNA Sequencing Data-Application to the ErbB Receptor Signaling Pathway.

A current challenge in systems biology is to predict dynamic properties of cell behaviors from public information such as gene expression data. The temporal dynamics of signaling molecules is critical for mammalian cell commitment. We hypothesized that gene expression levels are tightly linked with and quantitatively control the dynamics of signaling networks regardless of the cell type. Based on this idea, we developed a computational method to predict the signaling dynamics from RNA sequencing (RNA-seq) gene expression data. We first constructed an ordinary differential equation model of ErbB receptor → c-Fos induction using a newly developed modeling platform BioMASS. The model was trained with kinetic parameters against multiple breast cancer cell lines using autologous RNA-seq data obtained from the Cancer Cell Line Encyclopedia (CCLE) as the initial values of the model components. After parameter optimization, the model proceeded to prediction in another untrained breast cancer cell line. As a result, the model learned the parameters from other cells and was able to accurately predict the dynamics of the untrained cells using only the gene expression data. Our study suggests that gene expression levels of components within the ErbB network, rather than rate constants, can explain the cell-specific signaling dynamics, therefore playing an important role in regulating cell fate.

Essential role of the Crk family-dosage in DiGeorge-like anomaly and metabolic homeostasis.

CRK and CRKL (CRK-like) encode adapter proteins with similar biochemical properties. Here, we show that a 50% reduction of the family-combined dosage generates developmental defects, including aspects of DiGeorge/del22q11 syndrome in mice. Like the mouse homologs of two 22q11.21 genes CRKL and TBX1, Crk and Tbx1 also genetically interact, thus suggesting that pathways shared by the three genes participate in organogenesis affected in the syndrome. We also show that Crk and Crkl are required during mesoderm development, and Crk/Crkl deficiency results in small cell size and abnormal mesenchyme behavior in primary embryonic fibroblasts. Our systems-wide analyses reveal impaired glycolysis, associated with low Hif1a protein levels as well as reduced histone H3K27 acetylation in several key glycolysis genes. Furthermore, Crk/Crkl deficiency sensitizes MEFs to 2-deoxy-D-glucose, a competitive inhibitor of glycolysis, to induce cell blebbing. Activated Rapgef1, a Crk/Crkl-downstream effector, rescues several aspects of the cell phenotype, including proliferation, cell size, focal adhesions, and phosphorylation of p70 S6k1 and ribosomal protein S6. Our investigations demonstrate that Crk/Crkl-shared pathways orchestrate metabolic homeostasis and cell behavior through widespread epigenetic controls.

Clinical efficacy and safety of apatinib combined with S-1 in advanced esophageal squamous cell carcinoma.

Background Esophageal cancer is a very common malignant tumor in China, especially esophageal squamous cell carcinoma (ESCC), but there is currently no effective treatment for patients after first-line chemotherapy failure. Apatinib has shown promising outcomes in treatment with various solid tumors. Objectives To evaluate the clinical efficacy and safety of apatinib combined with S-1 in the treatment of advanced ESCC patients after first-line chemotherapy failure. Methods In this prospective study, fifteen patients with advanced ESCC who failed first-line chemotherapy were enrolled from Nov 2016 to Apr 2019. Patients received the combination therapy with apatinib (250-500 mg, once daily) plus S-1 (40-60 mg based on body surface area, twice daily). Primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), disease control rate (DCR) and objective response rate (ORR). Adverse events (AEs) were recorded to evaluate the safety. Results A total of 12 patients were included in the efficacy analysis. The median PFS was 6.23 months, and the median OS was 8.83 months. Two (16.67%) patients achieved partial remission, 9 patients (75.00%) achieved stable disease and 1 (8.33%) patient achieved progressive disease. DCR and ORR was 91.67%and 16.67%, respectively. Most frequent AEs were hypertension, myelosuppression, weakness, hemorrhage, hand-foot syndrome, total bilirubin elevation, sick, proteinuria, oral ulcer, loss of appetite, and transaminase elevation. The most AEs were in grade I~II. Conclusion The combination therapy of apatinib plus S-1 was effective and well tolerated in the treatment of advanced ESCC patients after first-line chemotherapy failure. The combination therapy has the potential to be a potent therapeutic option for advanced ESCC patients after first-line chemotherapy failure.

Class I histone deacetylase (HDAC) inhibitor CI-994 promotes functional recovery following spinal cord injury.

Spinal cord injury (SCI) induces severe and long-lasting neurological disability. Accumulating evidence has suggested that histone deacetylase (HDAC) inhibitors exert neuroprotective effects against various insults and deficits in the central nervous system. In the present study, we assessed the effect of the class I HDAC inhibitor CI-994 in a mouse model of SCI. Following SCI, mice were treated with either dimethyl sulfoxide (control vehicle) or 1, 10, or 30 mg/kg CI-994. Level of acetylated histone H3 expression was increased in the motor cortex and spinal cord of 10 mg/kg CCI-994-treated mice after SCI. CI-994 increased histone H3 acetylation in the myeloperoxidase-positive neutrophils and CD68-positive microglia/macrophages in the spinal cord. Although it did not appear to contribute to corticospinal tract axonal reorganization, intraperitoneal injection of CI-994 promoted behavioral recovery following SCI. Furthermore, administration of CI-994 suppressed neutrophil accumulation, inflammatory cytokine expressions, and neuronal loss as early as 3 days following injury. Thus, our findings indicate that HDAC inhibitors may improve functional recovery following SCI, especially during the early stages of the disease.

The RNA-binding protein MARF1 promotes cortical neurogenesis through its RNase activity domain.

Cortical neurogenesis is a fundamental process of brain development that is spatiotemporally regulated by both intrinsic and extrinsic cues. Although recent evidence has highlighted the significance of transcription factors in cortical neurogenesis, little is known regarding the role of RNA-binding proteins (RBPs) in the post-transcriptional regulation of cortical neurogenesis. Here, we report that meiosis arrest female 1 (MARF1) is an RBP that is expressed during neuronal differentiation. Cortical neurons expressed the somatic form of MARF1 (sMARF1) but not the oocyte form (oMARF1). sMARF1 was enriched in embryonic brains, and its expression level decreased as brain development progressed. Overexpression of sMARF1 in E12.5 neuronal progenitor cells promoted neuronal differentiation, whereas sMARF1 knockdown decreased neuronal progenitor differentiation in vitro. We also examined the function of sMARF1 in vivo using an in utero electroporation technique. Overexpression of sMARF1 increased neuronal differentiation, whereas knockdown of sMARF1 inhibited differentiation in vivo. Moreover, using an RNase domain deletion mutant of sMARF1, we showed that the RNase domain is required for the effects of sMARF1 on cortical neurogenesis in vitro. Our results further elucidate the mechanisms of post-transcriptional regulation of cortical neurogenesis by RBPs.

The newly identified migration inhibitory protein regulates the radial migration in the developing neocortex.

Neuronal migration is a crucial process in the organization of the developing cerebral cortex. Although a number of positive regulatory mechanisms of radial migration have been identified, negative cell-autonomous mechanisms have yet to be fully described. Here we report a newly identified Migration Inhibitory Protein (MINP, formerly known as 2900011O08Rik) that negatively regulates radial migration. MINP mRNA was specifically detected in the central and peripheral nervous system, and especially enriched in the cerebral cortex. MINP immunoreactivity co-localized with the neuronal marker Tuj1 and was detected in the cytoplasm of post-mitotic neurons. To elucidate the function of MINP in the developing brain, we performed in utero electroporation of MINP siRNA, MINP shRNA, or MINP-overexpressing vectors into mouse cortices and carried out in vivo migration assays. Whereas knockdown of MINP did not alter neuronal morphology, the radial migration was found accelerated by MINP knockdown, and reduced by MINP overexpression. This migration phenotype was also confirmed in vitro, indicating that MINP regulates neuronal migration in a cell-autonomous fashion. Furthermore, downregulation of MINP affected microtubule stability by interacting with tubulin that is a potential mechanism involved in the regulation of neuronal migration.

Preparation of monoclonal antibody against HPT and its application to detecting marker protein in genetically modified rice.

OBJECTIVE: To produce the monoclonal antibodies (mAbs) against hygromycin B phosphotransferase (HPT) and to develop immunoassay based on mAbs for biosafety assessment of HPT in genetically modified rice (GM rice). METHODS: BALB/c mice were immunized with purified recombinant 6His. HPT protein, and the conventional hybridoma technology was used to generate the monoclonal hybridoma cells. ELISA and Western blot were used to analyze the specificity of mAbs recognizing HPT and the cross reaction with other proteins. A double-Ab sandwich ELISA method was established to detect HPT expression level in the sck gene-modified rice plants. RESULTS: Four hybridomas, named F1, D4-2, D4-4, and D4-5, producing the mAbs against HPT were successfully obtained with the titer of ascetic mAbs ranging from 1x10(-4) to 1x10(-5). Identification of subclass showed that all the produced mAbs belonged to IgG1. Western blot showed specific binding reaction between the mAbs to the HPT proteins expressed in the GM rice. A double sandwich ELISA coated with anti-HPT polyclonal antibody was established with mAbs as sandwich antibody, which showed a sensitivity of 30ng/mL and did not crossreact with other proteins. The expression level of HPT in the leaves of sck-transformed lines was detected (80-150ng/mL). But HPT protein in the grain and seed of GM rice could not be detected using this ELISA assay. CONCLUSION: Anti-HPT mAbs prepared herein have a high specificity and can be used for rapid assay of HPT antigen. The expression level of HPT in the GM rice grain and seed is lower than our ELISA detection limit.

Stability of SARS coronavirus in human specimens and environment and its sensitivity to heating and UV irradiation.

OBJECTIVE: The causal agent for SARS is considered as a novel coronavirus that has never been described both in human and animals previously. The stability of SARS coronavirus in human specimens and in environments was studied. METHODS: Using a SARS coronavirus strain CoV-P9, which was isolated from pharyngeal swab of a probable SARS case in Beijing, its stability in mimic human specimens and in mimic environment including surfaces of commonly used materials or in household conditions, as well as its resistance to temperature and UV irradiation were analyzed. A total of 10(6) TCID50 viruses were placed in each tested condition, and changes of the viral infectivity in samples after treatments were measured by evaluating cytopathic effect (CPE) in cell line Vero-E6 at 48 h after infection. RESULTS: The results showed that SARS coronavirus in the testing condition could survive in serum, 1:20 diluted sputum and feces for at least 96 h, whereas it could remain alive in urine for at least 72 h with a low level of infectivity. The survival abilities on the surfaces of eight different materials and in water were quite comparable, revealing reduction of infectivity after 72 to 96 h exposure. Viruses stayed stable at 4 degrees C, at room temperature (20 degrees C) and at 37 degrees C for at least 2 h without remarkable change in the infectious ability in cells, but were converted to be non-infectious after 90-, 60- and 30-min exposure at 56 degrees C, at 67 degrees C and at 75 degrees C, respectively. Irradiation of UV for 60 min on the virus in culture medium resulted in the destruction of viral infectivity at an undetectable level. CONCLUSION: The survival ability of SARS coronavirus in human specimens and in environments seems to be relatively strong. Heating and UV irradiation can efficiently eliminate the viral infectivity.