The Gasdermin D N-terminal fragment acts as a negative feedback system to inhibit inflammasome-mediated activation of Caspase-1/11.

Inflammatory pathways usually utilize negative feedback regulatory systems to prevent tissue damage arising from excessive inflammatory response. Whether such negative feedback mechanisms exist in inflammasome activation remains unknown. Gasdermin D (GSDMD) is the pyroptosis executioner of downstream inflammasome signaling. Here, we found that GSDMD, after its cleavage by caspase-1/11, utilizes its RFWK motif in the N-terminal ß1-ß2 loop to inhibit the activation of caspase-1/11 and downstream inflammation in a negative feedback manner. Furthermore, an RFWK motif-based peptide inhibitor can inhibit caspase-1/11 activation and its downstream substrates GSDMD and interleukin-1ß cleavage, as well as lipopolysaccharide-induced sepsis in mice. Collectively, these findings provide a demonstration of the N-terminal fragment of GSDMD as a negative feedback regulator controlling inflammasome activation and a detailed delineation of the underlying inhibitory mechanism.

Unravelling CD4+ T cell diversity and tissue adaptation of Tregs in abdominal aortic aneurysms through single-cell sequencing.

Immune cell infiltration is a significant pathological process in abdominal aortic aneurysms (AAA). T cells, particularly CD4+ T cells, are essential immune cells responsible for substantial infiltration of the aorta. Regulatory T cells (Tregs) in AAA have been identified as tissue-specific; however, the time, location, and mechanism of acquiring the tissue-specific phenotype are still unknown. Using single-cell RNA sequencing (scRNA-seq) on CD4+ T cells from the AAA aorta and spleen, we discovered heterogeneity among CD4+ T cells and identified activated, proliferating and developed aorta Tregs. These Tregs originate in the peripheral tissues and acquire the tissue-specific phenotype in the aorta. The identification of precursors for Tregs in AAA provides new insight into the pathogenesis of AAA.

Crosstalk between Interleukin-1 Receptor-Like 1 and Transforming Growth Factor-ß Receptor Signaling Promotes Renal Fibrosis

IL-33, a member of the IL-1 family, acts as an alarmin in immune response. Epithelial-mesenchymal transition and transforming growth factor-ß (TGF-ß)­induced fibroblast activation are key events in the development of renal interstitial fibrosis. The current study found increased expression of IL-33 and interleukin-1 receptor-like 1 (IL1RL1, alias ST2), the receptor for IL-33, in human fibrotic renal tissues. In addition, IL-33­ or ST2-deficient mice showed significantly reduced levels of fibronectin, α-smooth muscle actin, and vimentin, and increased E-cadherin levels. In HK-2 cells, IL-33 promotes the phosphorylation of the TGF-ß receptor (TGF-ßR), Smad2, and Smad3, and the production of extracellular matrix (ECM), with reduced expression of E-cadherin. Blocking TGF-ßR signaling or suppressing ST2 expression impeded Smad2 and Smad3 phosphorylation, thereby reducing ECM production, suggesting that IL-33­induced ECM synthesis requires cooperation between the two pathways. Mechanistically, IL-33 treatment induced a proximate interaction between ST2 and TGF-ßRs, activating downstream Smad2 and Smad3 for ECM production in renal epithelial cells. Collectively, this study identified a novel and essential role for IL-33 in promoting TGF-ß signaling and ECM production in the development of renal fibrosis. Therefore, targeting IL-33/ST2 signaling may be an effective therapeutic strategy for renal fibrosis.

Low muscle density in children with osteogenesis imperfecta using opportunistic low-dose chest CT: a case-control study.

BACKGROUND: The aim of the study was to investigate the muscle differences in children with osteogenesis imperfecta (OI) using opportunistic low-dose chest CT and to compare different methods for the segmentation of muscle in children. METHODS: This single center retrospective study enrolled children with OI and controls undergoing opportunistic low-dose chest CT obtained during the COVID pandemic. From the CT images, muscle size (cross-sectional area) and density (mean Hounsfield Units [HU]) of the trunk muscles were measured at the mid-T4 and the mid-T10 level using two methods, the fixed thresholds and the Gaussian mixture model. The Bland-Altman method was also used to compute the strength of agreement between two methods. Comparison of muscle results between OI and controls were analyzed with Student t tests. RESULTS: 20 children with OI (mean age, 9.1 ± 3.3 years, 15 males) and 40 age- and sex-matched controls were enrolled. Mean differences between two methods were good. Children with OI had lower T4 and T10 muscle density than controls measured by the fixed thresholds (41.2 HU vs. 48.0 HU, p < 0.01; 37.3 HU vs. 45.9 HU, p < 0.01). However, children with OI had lower T4 muscle size, T4 muscle density, T10 muscle size and T10 muscle density than controls measured by the Gaussian mixture model (110.9 vs. 127.2 cm2, p = 0.03; 44.6 HU vs. 51.3 HU, p < 0.01; 72.6 vs. 88.0 cm2, p = 0.01; 41.6 HU vs. 50.3 HU, p < 0.01, respectively). CONCLUSIONS: Children with OI had lower trunk muscle density indicating that OI might also impair muscle quality. Moreover, the fixed thresholds may not be suitable for segmentation of muscle in children.

Network pharmacology analysis and experimental verification of the antitumor effect and molecular mechanism of isocryptomerin on HepG2 cells.

Isocryptomerin (ISO) is a flavonoid isolated from the natural medicine Selaginellae Herba, which has various pharmacological activities. This study investigated the antitumor effect and underlying molecular mechanism of ISO on hepatocellular carcinoma (HCC) HepG2 cells. The cell viability assay revealed that ISO has a considerable killing effect on HCC cell lines. The apoptosis assay showed that ISO induced mitochondria-dependent apoptosis through the Bad/cyto-c/cleaved (cle)-caspase-3/cleaved (cle)-PARP pathway. The network pharmacological analysis found 13 key target genes, and epidermal growth factor receptor (EGFR), AKT, mitogen-activated protein kinase (MAPK), and reactive oxygen species (ROS) signaling pathways were strongly associated with ISO against HCC. Further verification of the results showed that ISO induced apoptosis by increasing p-p38 and p-JNK expression and decreasing p-EGFR, p-SRC, p-ERK, and p-STAT3 expression. Furthermore, ISO induced G0/G1 phase arrest by downregulating p-AKT, Cyclin D, and CDK 4 expression and upregulating p21 and p27 expression in HepG2 cells. Moreover, ISO inhibited HepG2 cell migration by decreasing p-GSK-3ß, ß-catenin, and N-cadherin expression and increasing E-cadherin expression. Additionally, ISO promoted ROS accumulation in HepG2 cells, and ISO-induced apoptosis, arrest cell cycle, and inhibition of migration were reversed by an ROS scavenger, N-acetyl- l-cysteine. Overall, ISO induced cell apoptosis and cell cycle arrest and inhibited cell migration by ROS-mediated EGFR, AKT, and MAPK signaling pathways in HepG2 cells.

Dirac semimetal-assisted near-field radiative thermal rectifier and thermostat based on phase transition of vanadium dioxide.

The near-field thermal radiation has broad application prospects in micro-nano-scale thermal management technology. In this paper, we report the Dirac semimetal-assisted (AlCuFe quasicrystal) near-field radiative thermal rectifier (DSTR) and thermostat (DST), respectively. The DSTR is made of a Dirac semimetal-covered vanadium dioxide (VO2) plate and silicon dioxide (SiO2) plate separated by a vacuum gap. The left and right sides of DST are consisted of the SiO2 covered with Dirac semimetal, and the intermediate plate is the VO2. The strong coupling of the surface electromagnetic modes between the Dirac semimetal, SiO2, and insulating VO2 leads to enhance near-field radiative transfer. In the DSTR, the net radiative heat flux of VO2 in the insulating state is much larger than that in metallic state. When the vacuum gap distance d=100 nm, Fermi level EF=0.20 eV, and film thickness t=12 nm, the global rectification factor of DSTR is 3.5, which is 50% higher than that of structure without Dirac semimetal. In the DST, the equilibrium temperature of the VO2 can be controlled accurately to achieve the switching between the metallic and insulating state of VO2. When the vacuum gap distance d=60 nm, intermediate plate thickness δ=30 nm, and film thickness t=2 nm, with the modulation of Fermi level between 0.05-0.15 eV, the equilibrium temperature of VO2 can be controlled between 325-371 K. In brief, when the crystalline state of VO2 changes between the insulating and metallic state with temperature, the active regulation of near-field thermal radiation can be realized in both two-body and three-body parallel plate structure. This work will pave a way to further improve performance of near-field radiative thermal management and modulation.

Effective protection: the embryonic development and clinical outcomes of emergency vitrification of 1246 oocytes and Day 0-Day 5 embryos in a natural disaster.

STUDY QUESTION: Can emergency vitrification protect embryos and oocytes during natural disasters or other events that prevent normal practice to achieve satisfactory embryonic development and clinical outcomes at a later time? SUMMARY ANSWER: Emergency vitrification of oocytes and Day 0-Day 5 (D0-D5) embryos during disasters is a safe and effective protective measure. WHAT IS KNOWN ALREADY: When some destructive events such as floods, earthquakes, tsunamis, and other accidents occur, emergency vitrification in embryo laboratories to protect human embryos, oocytes, and sperm is one of the important measures of an IVF emergency plan. However, there are few detailed reports on emergency vitrification in a state of disaster, especially about oocytes and D0 zygotes. Therefore, the effectiveness and safety of emergency vitrification of oocytes and D0-D5 embryos in disaster states are still unclear. STUDY DESIGN, SIZE, DURATION: A retrospective study was made in the Reproductive Medicine Center of the First Affiliated Hospital of Zhengzhou University from January 2018 to November 2022. The record rainstorms in Zhengzhou, China, caused severe flooding, traffic disruptions, and power outages. From 17:30, 20 July 2021 to 17:30, 21 July 2021, 1246 oocytes and D0-D5 embryos of 155 patients were vitrified whilst the laboratory had only an emergency power supply. PARTICIPANTS/MATERIALS, SETTING, METHODS: As of 21 December 2021, 1149 emergency vitrified oocytes and D0-D5 embryos of 124 patients underwent frozen-thawed embryo transfer (FET). They were divided into the following four groups according to the days of embryo culture in vitro: oocyte group, Day 0-Day 1 (D0-D1) group, Day 2-Day 3 (D2-D3) group, and Day 4-Day 5 (D4-D5) group. Control groups for each were selected from fresh cycle patients who underwent IVF/ICSI from January 2018 to October 2021. Control and emergency vitrification patients were matched on criteria that included age, fertilization method, days of embryonic development, and number and grade of transferred embryos. A total of 493 control patients were randomly selected from the eligible patients and matched with the emergency vitrification groups in a ratio of 4:1. The results of assisted reproduction and follow-up of pregnancy were analyzed. The embryonic development, clinical outcomes, and birth outcomes in each group were statistically analyzed. MAIN RESULTS AND THE ROLE OF CHANCE: A significant difference was observed in fertilization rate (81% versus 72%, P = 0.022) between the oocyte group and the control group. Significant differences were also observed in the monozygotic twin pregnancy rate (10% versus 0%, P = 0.038) and ectopic pregnancy rate (5% versus 0%, P = 0.039) between the D0-D1 group and the control group. No significant differences (P > 0.05) were observed between vitrified oocytes/D0-D1 embryos/D2-D3 embryos and the control group on the number of high-quality embryos (3.17 ± 3.00 versus 3.84 ± 3.01, P = 0.346; 5.04 ± 3.66 versus 4.56 ± 2.87, P = 0.346; 4.85 ± 5.36 versus 5.04 ± 4.64, P = 0.839), the number of usable blastocysts (1.22 ± 1.78 versus 1.21 ± 2.03, P = 0.981; 2.16 ± 2.26 versus 1.55 ± 2.08, P = 0.090; 2.82 ± 3.23 versus 2.58 ± 3.32, P = 0.706), clinical pregnancy rate (56% versus 57%, P = 0.915; 55% versus 55%, P = 1.000; 40% versus 50%, P = 0.488), miscarriage rate (30% versus 15%, P = 0.496; 5% versus 11%, P = 0.678; 17% versus 20%, P = 1.000), and live birth rate (39% versus 49%, P = 0.460; 53% versus 50%, P = 0.772; 33% versus 40%, P = 0.635). No significant differences (P > 0.05) were observed between the D4-D5 group and the control group on clinical pregnancy rate (40% versus 55%, P = 0.645), miscarriage rate (0% versus 18%, P = 1.000), and live birth rate (40% versus 45%, P = 1.000). LIMITATIONS, REASONS FOR CAUTION: The retrospective study design is a limitation. The timing and extent of natural disasters are unpredictable, so the sample size of vitrified oocytes, zygotes, and embryos is beyond experimental control. WIDER IMPLICATIONS OF THE FINDINGS: This study is the first study analyzing embryonic development, clinical outcomes, and birth outcomes of large samples of oocytes, D0 zygotes, and D1-D5 embryos after emergency vitrification under the disaster conditions. The results show that emergency vitrification is a safe and effective protective measure applicable to oocytes and D0-D5 embryos. The embryology laboratories need to be equipped with an emergency uninterrupted power supply capable of delivering for 6-8 h at full load. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the National Natural Science Foundation of China (grant 81871206). The authors declare that they have no conflicts of interest. All authors have completed the ICMJE Disclosure form. TRIAL REGISTRATION NUMBER: N/A.

Topological plasmons in stacked graphene nanoribbons.

In this Letter, we theoretically study the topological plasmons in Su-Schrieffer-Heeger (SSH) model-based graphene nanoribbon (GNR) layers. We find that for the one-dimensional (1D) stacked case, only two topological modes with the field localized in the top or bottom layer are predicted to exist by the Zak phase. When we further expand the stacked 1D GNR layers to two-dimensional (2D) arrays in the in-plane direction, the topology is then characterized by the 2D Zak phase, which predicts the emergence of three kinds of topological modes: topological edge, surface, and corner modes. For a 2D ribbon array with Nx × Ny units, there are 4(Ny - 1), 4(Nx - 1), and 4 topological edge, surface, and corner modes, and the field is highly localized at the edge/surface/corner ribbons. This work offers a platform to realize topological modes in GNRs and could be important for the design of topological photonic devices such as lasers and sensors.

SNS-023 sensitizes hepatocellular carcinoma to sorafenib by inducing degradation of cancer drivers SIX1 and RPS16.

Hepatocellular carcinoma (HCC) remains challenging due to the lack of efficient therapy. Promoting degradation of certain cancer drivers has become an innovative therapy. The nuclear transcription factor sine oculis homeobox 1 (SIX1) is a key driver for the progression of HCC. Here, we explored the molecular mechanisms of ubiquitination of SIX1 and whether targeting SIX1 degradation might represent a potential strategy for HCC therapy. Through detecting the ubiquitination level of SIX1 in clinical HCC tissues and analyzing TCGA and GEPIA databases, we found that ubiquitin specific peptidase 1 (USP1), a deubiquitinating enzyme, contributed to the lower ubiquitination and high protein level of SIX1 in HCC tissues. In HepG2 and Hep3B cells, activation of EGFR-AKT signaling pathway promoted the expression of USP1 and the stability of its substrates, including SIX1 and ribosomal protein S16 (RPS16). In contrast, suppression of EGFR with gefitinib or knockdown of USP1 restrained EGF-elevated levels of SIX1 and RPS16. We further revealed that SNS-023 (formerly known as BMS-387032) induced degradation of SIX1 and RPS16, whereas this process was reversed by reactivation of EGFR-AKT pathway or overexpression of USP1. Consequently, inactivation of the EGFR-AKT-USP1 axis with SNS-032 led to cell cycle arrest, apoptosis, and suppression of cell proliferation and migration in HCC. Moreover, we showed that sorafenib combined with SNS-032 or gefitinib synergistically inhibited the growth of Hep3B xenografts in vivo. Overall, we identify that both SIX1 and RPS16 are crucial substrates for the EGFR-AKT-USP1 axis-driven growth of HCC, suggesting a potential anti-HCC strategy from a novel perspective.

Cognitive appraisal and depression in cancer patients undergoing chemotherapy: mediation by perceived stress and self-efficacy.

PURPOSE: Cancer patients undergoing chemotherapy are prone to suffering a higher incidence rate of depression, leading to poor quality of life. However, how cancer affects depression is unclear. This study aimed to examine whether the relationship between cognitive appraisal and depression is mediated by perceived stress and self-efficacy in cancer patients undergoing chemotherapy. METHODS: A total of 421 cancer patients undergoing chemotherapy participated in this cross-sectional survey. Cognitive appraisal of cancer, perceived stress, self-efficacy, and depression were measured with the Perceived Life Threat Scale, Perceived Stress Scale, General Self-efficacy Scale and Hospital Anxiety, and Depression Scale-Depression Scale, respectively. Path analysis was performed to analyze the mediating effects of perceived stress and self-efficacy on the relationship between cognitive appraisal of cancer and depression. RESULTS: Cognitive appraisal of cancer exerted direct (b = 0.066, SE = 0.020, p < 0.001, bias-corrected 95% CI = [0.027, 0.106]) and indirect (mediated by depression and insomnia) (b = 0.136, SE = 0.015, p < 0.001, bias-corrected 95% CI = [0.107, 0.167]) effects on depression. Perceived stress and self-efficacy were significant in mediating the relationship between cognitive appraisal of cancer and depression (b = 0.101, SE = 0.014, p < 0.001, bias-corrected 95% CI = [0.074, 0.132]; b = 0.021, SE = 0.006, p < 0.001, bias-corrected 95% CI = [0.006, 0.028], respectively). Additionally, a sequential mediating effect of perceived stress via self-efficacy was found, and the mediating effect size was 0.014 (p < 0.01, bias-corrected 95% CI = [0.010,0.034]). CONCLUSIONS: This study suggests that medical staff could prevent or relieve depression through improving self-efficacy or reducing perceived stress in cancer patients undergoing chemotherapy.