Assessing the potential molecular mechanism of arsenite-induced skin cell senescence.

Arsenic exposure is a public health concern worldwide. Skin damage, as a typical lesion of arsenic exposure, the mechanism is still unknown. Studies have found that cellular senescence plays a key role in arsenic-induced skin damage, and the previous research found that the ERK/CEBPB signaling pathway may be an important molecular event of arsenic-induced skin cell senescence, but its specific mechanism is unknown. In this study, genetic engineering technology was used to construct stable HaCaT cell lines, and the role and mechanism of ERK/CEBPB signaling pathway in arsenic-induced HaCaT cell senescence were verified by knockdown and overexpression of ERK and CEBPB in both forward and backward. It was found that knockdown of CEBPB or ERK can downregulate the ERK/CEBPB signaling pathway and reduce arsenic-induced skin cell senescence. In contrast to knockdown, overexpression of CEBPB or ERK can upregulate the ERK/CEBPB signaling pathway and aggravate the senescence of skin cells caused by arsenic. These findings suggest that sodium arsenite can further promote SASP secretion and the expression of p53, p21 and p16 INK4a by activating the ERK/CEBPB signaling pathway, induce cell cycle arrest and trigger cellular senescence.

Assessing the double-edged of extracellular signal-regulated kinase/CCAAT-enhancer-binding protein beta signaling pathway in arsenic-induced skin damage and its potential foodborne interventions.

Arsenic exposure is a major environmental public health challenge worldwide. As typical manifestations for arsenic exposure, the pathogenesis of arsenic-induced skin lesions has not been fully elucidated, as well as the lack of effective control measures. In this study, we first determined the short-term and high-dose arsenic exposure can increase the apoptosis rates, while long-term low-dose arsenic exposure decrease the apoptosis rates. Then, the HaCaT cells with knockdown and overexpression of CCAAT-enhancer-binding protein ß (CEBPB) and extracellular signal-regulated kinase (ERK) were constructed. The results demonstrate that knockdown of CEBPB and ERK can reduce NaAsO2 -induced cell apoptosis by inhibiting ERK/CEBPB signaling pathway and vice versa. Further cells were treated with Kaji-Ichigoside F1 (KF1). The results clearly show that KF1 can decrease the arsenic-induced cell apoptosis rates and the expression of ERK/CEBPB signaling pathway-related genes. These results provide evidence that ERK/CEBPB signaling pathway acts as a double-edged sword in arsenic-induced skin damage. Another interesting finding was that KF1 can alleviate arsenic-induced skin cell apoptosis by inhibiting the ERK/CEBPB signaling pathway. This study will contribute to a deeper understanding of the mechanisms of arsenic-induced skin cell apoptosis, and our findings will help to identify a potential food-borne intervention in arsenic detoxification.

S1P-S1PR3-RAS promotes the progression of S1PR3hi TAL1+ T-cell acute lymphoblastic leukemia that can be effectively inhibited by an S1PR3 antagonist.

TAL1+ T-cell acute lymphoblastic leukemia (T-ALL) is a distinct subtype of leukemia with poor outcomes. Through the cooperation of co-activators, including RUNX1, GATA3, and MYB, the TAL1 oncoprotein extends the immature thymocytes with autonomy and plays an important role in the development of T-ALL. However, this process is not yet well understood. Here, by investigating the transcriptome and prognosis of T-ALL from multiple cohorts, we found that S1PR3 was highly expressed in a subset of TAL1+ T-ALL (S1PR3hi TAL1+ T-ALL), which showed poor outcomes. Through pharmacological and genetic methods, we identified a specific survival-supporting role of S1P-S1PR3 in TAL1+ T-ALL cells. In T-ALL cells, TAL1-RUNX1 up-regulated the expression of S1PR3 by binding to the enhancer region of S1PR3 gene. With hyperactivated S1P-S1PR3, T-ALL cells grew rapidly, partly by activating the KRAS signal. Finally, we assessed S1PR3 inhibitor TY-52156 in T-ALL patient-derived xenografts (PDXs) mouse model. We found that TY-52156 attenuated leukemia progression efficiently and extended the lifespan of S1PR3hi TAL1+ T-ALL xenografts. Our findings demonstrate that S1PR3 plays an important oncogenic role in S1PR3hi TAL1+ T-ALL and may serve as a promising therapeutic target.

Microstructure, Mechanical and Tribological Properties of High-Entropy Carbide (MoNbTaTiV)C5.

High-entropy carbide (NbTaTiV)C4 (HEC4), (MoNbTaTiV)C5 (HEC5), and (MoNbTaTiV)C5-SiC (HEC5S) multiphase ceramics were prepared by spark plasma sintering (SPS) at 1900 to 2100 °C, using metal carbide and silicon carbide (SiC) as raw materials. Their microstructure, and mechanical and tribological properties were investigated. The results showed that the (MoNbTaTiV)C5 synthesized at 1900-2100 °C had a face-centered cubic structure and density higher than 95.6%. The increase in sintering temperature was conducive to the promotion of densification, growth of grains, and diffusion of metal elements. The introduction of SiC helped to promote densification but weakened the strength of the grain boundaries. The average specific wear rates for HEC4 were within an order of magnitude of 10-5 mm3/N·m, and for HEC5 and HEC5S were within a range of 10-7 to 10-6 mm3/N·m. The wear mechanism of HEC4 was abrasion, while that of HEC5 and HEC5S was mainly oxidation wear.

Global trends and forecasts of breast cancer incidence and deaths.

Breast cancer (BC) is one of the major public health challenges worldwide. Studies that address the new evidence on trends of BC are of great importance for preventing and controlling the occurrence and development of diseases and improving health. The aim of this study was to analyze the outcomes for the global burden of disease (GBD), incidence, deaths, and risk factors for BC from 1990 to 2019, and predict the GBD of BC until 2050 to inform global BC control planning efforts. In this study, the results show that the regions with low levels of socio-demographic index (SDI) will have the largest disease burden of BC in the future. The leading global risk factor for death attributable to BC in 2019 was metabolic risks, followed by behavioral risks. This study supports the worldwide urgent need for comprehensive cancer prevention and control strategies to reduce exposure, early screening, and improve treatment to effectively reduce the GBD of BC.

Matrine induces autophagy in human neuroblastoma cells via blocking the AKT-mTOR pathway.

Neuroblastoma (NB) is one of the most common malignant solid tumors in children. Despite significant advances in the treatment strategy, the long-term survival rate of NB patients is only 50%. Developing new agents for NB patients deserves attention. Recent research indicates that matrine, a natural quinolizidine alkaloid component extracted from the traditional Chinese medicine Sophora root, is widely used for various diseases, including antitumor effects against a variety of cancers. However, the effect of matrine on NB is unknown. Herein, we found that matrine exerted antiproliferative activity in human NB cells in dose- and time-dependent manner. Matrine triggered autophagy in NB cells by blocking the AKT-mTOR signaling pathway and suppressing the phosphorylation of AKT and mTOR. 3-Methyladenine (3-MA), a PI3K inhibitor, protected against matrine-induced inhibition of cell proliferation, further supporting that the antitumor activity of matrine was at least partly autophagy-dependent. In vivo, matrine reduced tumor growth of SK-N-DZ cells in a dose-dependent manner. Matrine treatment significantly declined the phosphorylation of AKT and mTOR and enhanced the LC3 II/GAPDH ratio in NB xenografts. Altogether, our work uncovered the molecular mechanism underlying matrine-induced autophagy in NB and provided implications for matrine as a potential therapeutic agent against NB.

[Induction of mouse T lymphocyte differentiation in vitro by thymic organoids].

Objective To induce the differentiation of hematopoietic stem progenitor cells (HSPCs) into T cell by creating thymic organoids and simulating the three-dimensional structure of thymus tissue in vitro. Methods The retroviral vector expressing the DLL1 and Green fluorescent protein (GFP) was constructed, and the OP9-DLL1 cell line was established in OP9 cells with the aid of retroviral infection. The mRNA and protein level of DLL1 in OP9-DLL1 cells was detected by quantitative real-time PCR and Western blot respectively. Immunofluorescence assay was used to detect the DLL1 protein expression and distribution in OP9-DLL1 cells. HSPCs were extracted from E13.5 fetal liver and bone marrow of C57BL/6 mouse, and mixed with OP9-DLL1 cells in an appropriate ratio respectively, then compacted by centrifuging and cultured at the air-liquid interface in medium. Fluorescence microscope was used to observe the growth of thymic organoids. Flow cytometry was used to detect the expression of T cell surface markers, including CD3, CD4, CD8, CD25, CD44, CD45, CD117 and TCRß. Immunofluorescence cytochemical staining was used to observe the distribution of hematopoietic cells in thymic organoids. Results The retroviral vector expressing DLL1 and GFP was successfully constructed. The OP9 cells were infected with the retrovirus constructed, and OP9-DLL1 cells were obtained by GFP screening. The mRNA and protein level of DLL1 in OP9-DLL1 cells significantly increased, and DLL1 was expressed in the membrane OP9-DLL1 cells. During the 40 days of culture, the thymic organoids remained in good condition and increased gradually in volume. The thymic organoids induced programmed differentiation of T cells, and differentiation of HSPCs into CD3+ T cells. Conclusion OP9-DLL1 cells can be used to construct thymic organoids and to induce differentiation of HSPCs into T cells in vitro.

[ß-arrestin1 overexpression suppresses progression of human T-cell acute lymphatic leukemia Molt-4 cell xenograft in mice].

OBJECTIVE: To investigate the effect of ß-arrestin1 overexpression on tumor progression in a NCG mouse model bearing T-cell acute lymphocytic leukemia (T-ALL) Molt-4 cell xenograft. METHODS: Molt-4 cells were tagged with firefly-luciferase (F-Luc) by lentiviral infection, and fluorescence intensity of the cells was detected using a luminescence detector. Molt-4 cell lines with ß-arrestin1 overexpression or knockdown were constructed by lentivirus infection and injected via the tail vein in sub-lethal irradiated NCG mice. Body weight changes and survival time of the xenografted mice were observed, and the progression of T-ALL in the mice was evaluated using an in vivo fluorescence imaging system. Sixteen days after xenografting, the mice were euthanatized and tumor cell infiltration was observed in the slices of the liver and spleen. RESULTS: We successfully tagged Molt-4 cells with F-Luc and overexpressed or knocked down ß-arrestin1 in the tagged cells. Bioluminescent imaging showed obvious luminescence catalyzed by F-Luc in Molt-4 cells. After injection of Molt-4-Luc cells into irradiated NCG mice, a gradual enhancement of luminescence in the xenografted mice was observed over time, while the body weight of the mice decreased. Compared with the control mice, the mice xenografted with ß-arrestin1-overexpressing Molt-4 cells had significantly prolonged survival time (P < 0.001), while the survival time of the mice xenografted with Molt-4 cells with ß- arrestin1 knockdown was significantly shortened (P < 0.001). Histological examination revealed fewer infiltrating tumor cells in the liver and spleen of the mice xenografted with ß-arrestin1-overexpressing Molt-4 cells in comparison with the mice bearing parental Molt-4 cell xenografts. CONCLUSIONS: ß-arrestin1 overexpression suppresses tumor progression in mice bearing Molt-4 cell xenograft.