Starvation-induced phosphorylation activates gasdermin A to initiate pyroptosis.

Pyroptosis, a pro-inflammatory form of programmed cell death, is crucial for host defense against pathogens and danger signals. Proteolytic cleavage of gasdermin proteins B-E (GSDMB-GSDME) is well established as a trigger for pyroptosis, but the intracellular activation mechanism of GSDMA remains elusive. Here, we demonstrate that severe starvation induces pyroptosis through phosphorylation-induced activation of GSDMA. Nutrient stresses stimulate GSDMA activation via phosphorylation mediated by Unc-51-like autophagy-activating kinase 1 (ULK1). Phosphorylation of Ser353 on human GSDMA by ULK1 or the phospho-mimetic Ser353Asp mutant of GSDMA liberates GSDMA from auto-inhibition, facilitating its membrane targeting and initiation of pyroptosis. To further validate the significance of GSDMA phosphorylation, we generated a constitutively active mutant Ser354Asp of mouse Gsdma, which induced skin inflammation and hyperplasia in mice, reminiscent of phenotypes with activated Gsdma. This study uncovers phosphorylation of GSDMA as a mechanism underlying pyroptosis initiation and cellular response to nutrient stress.

CRLF1 bridges AKT and mTORC2 through SIN1 to inhibit pyroptosis and enhance chemo-resistance in ovarian cancer.

Ovarian cancer, the second most leading cause of gynecologic cancer mortality worldwide, is challenged by chemotherapy resistance, presenting a significant hurdle. Pyroptosis, an inflammation-linked programmed cell death mediated by gasdermins, has been shown to impact chemoresistance when dysregulated. However, the mechanisms connecting pyroptosis to chemotherapy resistance in ovarian cancer are unclear. We found that cytokine receptor-like factor 1 (CRLF1) is a novel component of mTORC2, enhancing AKT Ser473 phosphorylation through strengthening the interaction between AKT and stress-activated protein kinase interacting protein 1 (SIN1), which in turn inhibits the mitogen-activated protein kinase kinase kinase 5 (ASK1)-JNK-caspase-3-gasdermin E pyroptotic pathway and ultimately confers chemoresistance. High CRLF1-expressing tumors showed sensitivity to AKT inhibition but tolerance to cisplatin. Remarkably, overexpression of binding-defective CRLF1 variants impaired AKT-SIN1 interaction, promoting pyroptosis and chemosensitization. Thus, CRLF1 critically regulates chemoresistance in ovarian cancer by modulating AKT/SIN1-dependent pyroptosis. Binding-defective CRLF1 variants could be developed as tumor-specific polypeptide drugs to enhance chemotherapy for ovarian cancer.

Reducing anxiety and enhancing satisfaction in thyroid patients with DietLens application during radioactive iodine therapy: A quasi-experimental study.

Hyperthyroidism and thyroid cancer significantly impact health, and often require Radioactive Iodine (RAI) therapy. Anxiety is common in patients undergoing RAI, particularly related to dietary compliance. This study aimed to assess the effectiveness of the mobile health application, DietLens in reducing anxiety and increasing satisfaction in patients preparing for RAI therapy, focusing on low-iodine diet (LID). A quasi-experimental study was conducted in a Singapore tertiary hospital outpatient department from March 13, 2019 to March 27, 2020, involving patients scheduled for their first RAI treatment. Participants were divided into a control group receiving standard care and an intervention group using DietLens alongside standard care. Anxiety levels were assessed using the Zung Self-Rating Anxiety Scale, and satisfaction levels were measured through self-reported questionnaires. In the study, 56 participants were initially divided into control (n = 28) and intervention (n = 28) groups. After accounting for dropouts, 50 participants finished the study, with each group comprising 25 individuals. Anxiety levels were similar between groups pre-intervention. Post-intervention, the intervention group displayed a significant decrease in anxiety levels compared to the control group (independent t-test: t (48) = 2.50, p = 0.02). The multivariate linear regression analysis indicated that being in the intervention group was significantly associated with a decrease in post-intervention anxiety score (ß = -4.03, 95 % CI: -7.33 to -0.72, p = 0.02). Fisher's Exact Test revealed a borderline significant difference in satisfaction with educational materials and the overall treatment process, with 100 % of the intervention group expressing satisfaction compared to 80 % in the control group, resulting in a p-value of 0.052 in both instances. DietLens was effective in reducing anxiety and enhancing satisfaction related to RAI therapy preparation, particularly in managing a LID, highlighting a beneficial role for digital interventions in healthcare settings.

Effects of ferroptosis-related gene HSPB1 on acute myeloid leukemia.

INTRODUCTION: The purpose of this study was to investigate the effects and potential mechanisms of ferroptosis-related gene heat shock protein beta-1 (HSPB1) on acute myeloid leukemia (AML). METHODS: The RNA-seq and clinical data of AML samples were obtained from the Genomic Data Commons database, and the FerrDb database was used to screen the marker, drive and suppressor of ferroptosis. Besides, DESeq2 was applied for differential expression analysis on AML samples and screening for differentially expressed genes (DEGs). The screened DEGs were subjected to the intersection analysis with ferroptosis-related genes to identify the ferroptosis-related DEGs. Next, the functional pathways of ferroptosis-related DEGs were further be discussed by Gene Ontology as well as Kyoto Encyclopedia of Genes and Genomes enrichment analysis of DEGs. Additionally, lasso regression analysis was employed to determine the differential genes related to prognosis in patients with AML and the survival analysis was performed. Subsequently, quantitative real-time polymerase chain reaction and western blot assay were applied to detect the mRNA and protein expression levels of HSPB1 in normal/AML bone marrow tissues and human normal (HS-5)/AML (HL-60) bone marrow cells, respectively. Furthermore, HSPB1 was knocked down to assess the expression changes of glutathione peroxidase 4 and acyl-CoA synthetase long-chain family member 4. Ultimately, the viability and oxidative stress levels of HL-60 were analyzed by Cell Counting Kit-8 and biochemical detection. RESULTS: A total of 4986 DEGs were identified in AML samples, with 3324 up-regulated and 1662 down-regulated. The enrichment analysis illustrated that ferroptosis-related DEGs were significantly enriched in response to metal irons, oxidative stress, and other pathways. After lasso regression analysis, 17 feature genes related to the prognosis of patients with AML were obtained, with HSPB1 exhibiting a significant correlation. The reliability of our models was verified by Cox regression analysis and survival analysis of the hazard model. Furthermore, the outcomes of quantitative real-time polymerase chain reaction and western blot showed that mRNA and protein expression levels of HSPB1 were significantly increased in the AML Group and HL-60 cells. The knockdown of HSPB1 in HL-60 cells reduced the protein level of glutathione peroxidase 4, increased the protein level of acyl-CoA synthetase long-chain family member 4, decreased the cell viability, and aggravated oxidative stress. CONCLUSION: Ferroptosis-related gene HSPB1 is highly expressed in patients with AML. In addition, HSPB1 may be involved in the occurrence and development of AML by regulating oxidative stress and ferroptosis-related pathways. This study provides new clues for further understanding of AML molecular mechanisms. Also, HSPB1 is expected to be a potential therapeutic target for AML in the future.

The Expression of Two Distinct Sets of Glycolytic Enzymes Reveals Differential Effects of Glycolytic Reprogramming on Pancreatic Ductal Tumorigenesis in Mice.

Pancreatic ductal adenocarcinoma (PDAC) is associated with enhanced aerobic glycolysis through elevated glucose uptake and the upregulated expression of genes encoding rate-limiting glycolytic enzymes. However, the direct impact of altered glycolytic pathways on pancreatic tumor progression has not been thoroughly investigated. Here, we utilized two strains of BAC transgenic mice with pancreatic expression of two distinct sets of glycolytic genes each arranged in a polycistronic fashion (PFKFB3-HK2-GLUT1 and LDHA-PDK1, respectively) to investigate the role of altered glycolysis on the development of pancreatic ductal tumor development in the Pdx1-Cre; LSL-KrasG12D mice. The overexpression of the two sets of glycolytic genes exhibited no significant effects on tumor development in the 4-5-month-old mice (the PanIN2 lesions stage). In the 9-10-month-old mice, the overexpression of PFKFB3-HK2-GLUT1 significantly accelerated PanIN3 progression, exhibiting elevated levels of ductal cell marker CK19 and tumor fibrosis. Surprisingly, the overexpression of LDHA-PDK1 significantly attenuated the progression of PanIN3 in the 9-10-month-old mice with significantly downregulated levels of CK19 and fibrosis. Therefore, distinct set of glycolytic enzymes that are involved in different glycolytic routes exhibited contrasting effects on pancreatic ductal tumor development depending on the tumor stages, providing novel insights into the complexity of the glycolytic pathway in the perspective of PDAC development and therapy.

[Effect of Polyvinyl Alcohol/Graphene Oxide Aerogel on the Biological Characteristics of Acute Leukemia Cell Lines].

OBJECTIVE: To investigate the effects of polyvinyl alcohol (PVA) + graphene oxide (GO, weight content 1 wt%) aerogel three-dimensional (3D) scaffolds culture system on the proliferation, phenotype and drug resistance of ALL cell line Jurkat and AML cell line HL-60. METHODS: Jurkat cells and HL-60 cells were seeded in PVA+GO aerogel scaffolds for culture, and the structure of cells were observed by the scanning electron microscopy. Cell proliferation activity was measured by Cell Counting Kit-8 (CCK-8), cell phenotypes were analyzed by flow cytometry after fluorescent staining, then were compared with 2D cultured cells. Ara-C was used in drug resistance experiment, and CCK8 was used to detected cell proliferation activity. RESULTS: The proliferation activity of Jurkat cells grown in aerogel scaffolds was higher than that by 2D cultured in long-term culture. However, in HL-60 cells, the proliferation activity on 3D scaffold only at the 8th to 20th day was higher than that on the traditional 2D culture. Expression of CD4 in Jurkat cells increased after culture for 30 days, but the cell phenotypes in the 3D aerogel scaffolds were similar to 2D cultured cells. Phenotype of HL-60 cells was certainly changed after culture for 30 days, the cells can be divided into CD13+CD14-CD45+HLA-DR+,CD13-CD14--CD45+HLA-DR+ and CD13-CD14-CD45+HLA-DR- groups, and a new CD13+CD14-CD45-HLA-DR+ group of cells appeared in the cells cultured in 3D scaffolds, but not in 2D cultured cells. Drug resistance experiments showed that Jurkat cells in aerogel scaffolds have stronger drug resistance than those in 2D culture. CONCLUSION: PVA+GO (1 wt%) aerogel scaffolds can improve the proliferation and drug resistance of leukemia cells, and the phenotypes were the same as those in 2D culture, which can be used for cell amplification and biology characteristics studies and drug experiments. However, cell phenotypes should be analyzed before culture, and the effects of phenotypes changes on drug resistance should be eliminated.

Combination of 4-hydroperoxy cyclophosphamide and methotrexate inhibits IL-6/sIL-6R-induced RANKL expression in fibroblast-like synoviocytes via suppression of the JAK2/STAT3 and p38MAPK signaling pathway.

Although conventional combination therapy is effective for most patients with rheumatoid arthritis (RA), many still do not respond to current therapies. Therefore, novel combination regimens that better target cellular processes involved in RA pathogenesis are required. Preliminary studies have demonstrated the beneficial effects of a combination of cyclophosphamide (CTX) and methotrexate (MTX) in models of RA. Using western blotting, real-time polymerase chain reaction, enzyme-linked immunosorbent assays, and immunofluorescent staining, we demonstrated that the combination of 4-hydroperoxy CTX (4-H-CTX) and MTX inhibited the expression of receptor activator of nuclear factor-κB ligand (RANKL) in fibroblast-like synoviocytes (FLS) treated with the interleukin (IL)-6/soluble IL-6 receptor (sIL-6R) complex. To elucidate the mechanisms underlying this effect, we treated RA-FLS with the JAK2/STAT3 inhibitor AG490 or p38MAPK inhibitor SB203580. The results showed that IL-6/sIL-6R-induced RANKL upregulation required phosphorylation-mediated activation of STAT3 and p38 signaling, and that 4-H-CTX and/or MTX inhibited RANKL expression in IL-6/sIL-6R-stimulated FLS by suppressing JAK2/STAT3 and p38MAPK signaling. This study demonstrated for the first time the inhibitory effects of 4-H-CTX and MTX on RANKL expression in IL-6/sIL-6R-stimulated FLS via suppression of STAT3 and p38MAPK phosphorylation. These results identify promising therapeutic agents that might have clinical applications in patients with RA who are at high risk of bone erosion or do not respond well to conventional therapy.

Comparative Proteomic Analysis of the Effect of the Four-Herb Chinese Medicine ANBP on Promoting Mouse Skin Wound Healing.

Traditional Chinese medicine has great potential to improve wound healing. ANBP, the mixture of 4 Chinese herbs- Agrimoniapilosa, Nelumbonucifera, Boswelliacarteri, and Pollen typhae-is effective in trauma treatment while its mechanism is still elusive. In this study, quantitative proteomics and bioinformatics analyses were performed to decipher the possible roles of ANBP in accelerated wound healing of mouse skin. Among all 3171 identified proteins, 90, 71, 80, and 140 proteins were found to be differently expressed in 6 hours, 3 days, 7 days, and 14 days ANBP-treated tissues compared with corresponding control tissues, respectively. The result showed that different biological processes and pathways were activated at different healing stages. At the early healing stage, ANBP treatment mainly affected several biological processes, including immune and defense response, vascular system restoration, hemostasis and coagulation regulation, lipid metabolism and signal transduction, while muscle tissue, hair, epidermis, extracellular matrix and tissue remodeling related activities were the major events in ANBP promoted later wound healing. This is the first quantitative proteome study of ANBP-treated wound tissues, which provide a new perspective for the mechanism of ANBP accelerated wound healing and is of guiding significance for clinical application of ANBP in trauma disorders cure.

[Ratio of Primary Bone Marrow Cells after Induction Chemothrapy for Two Weeks in the Patients with Ph- ALL and Its Influence on Complete Remission and Overall Progrosis].

OBJECTIVE: To investigate the influence of bone marrow blasts ratio after induction chemotherapy for 2 weeks in patients with Ph- ALL, and it's influence on complete remission (CR) and overall prognosis. METHODS: A total of 172 patients with Ph- ALL in our hospital from March 2012 to February 2016 were selected. The bone marrow blast ratio was analyzed by the receiver-operating characteristic curve (ROC) in patients after induction chemotherapy for 2 weeks, at same time its influence on CR and overall prognosis of Ph- ALL patients was evaluated. RESULTS: The cutoff value of CR was 0.075, its area under ROC was 0.763; the comparison of area under ROC with Az=0.5 showed statistically significant difference, therefore 172 patients with Ph- ALL were grouped according to bone marrow blast ratio after induction chemotherapy for 2 weeks: 104 cases (60.5%) with bone marrow blast ratio <0.075, 68 cases (39.5%) with bone marrow blast ratio ≥0.075. The Ph- ALL patinets with bone marrow blast ratio <0.075 who achieved CR and finally achieved CR after induction chemotherapy for 4 weeks acconnted for 89 (85.6%) and 99(95.2%) respectively, which were significantly higher than those in Ph- ALL patients with bone marrow blast ratio≥0.075, [29(42.6%) and 52 (76.5%)](P<0.05). In addition, the influencing factor clinically reducing the OS and DFS rate of patients and enhancing the ralapse rate of patients were mainly chemotherapy, the failure of induction chemotherapy (patients did not achieve CR after induction therapy for 4 weeks), the bone marrow blast ratio≥0.075 after induction treatment for 2 weeks, and CNSL at diagnosis and so on, while the enhaced WBC count at diagnosis was poor factor affecting the DFS rate of patients. CONCLUSION: After induction chemotherapy for 2 weeks, the elevated bone marrow blast ratio in Ph- ALL patients will be infavourable to CR, and the overall prognosis is poor.

p53 pathway is involved in cell competition during mouse embryogenesis.

The function of tumor suppressor p53 has been under intense investigation. Acute stresses such as DNA damage are able to trigger a high level of p53 activity, leading to cell cycle arrest or apoptosis. In contrast, the cellular response of mild p53 activity induced by low-level stress in vivo remains largely unexplored. Murine double minute (MDM)2 and MDM4 are two major negative regulators of p53. Here, we used the strategy of haploinsufficiency of Mdm2 and Mdm4 to induce mild p53 activation in vivo and found that Mdm2+/-Mdm4+/- double-heterozygous mice exhibited normal embryogenesis. However, closer examination demonstrated that the Mdm2+/-Mdm4+/- cells exhibited a growth disadvantage and were outcompeted during development in genetic mosaic embryos that contained wild-type cells. Further study indicated the out-competition phenotype was dependent on the levels of p53. These observations revealed that cells with mild p53 activation were less fit and exhibited altered fates in a heterotypic environment, resembling the cell competition phenomenon first uncovered in Drosophila By marking unfit cells for elimination, p53 may exert its physiological role to ensure organ and animal fitness.

Mouse Double Minute 2 Actively Suppresses p53 Activity in Oocytes during Mouse Folliculogenesis.

The p53 signaling network is indispensible in cellular stress responses and tumor suppression. Negative regulations of p53 by mouse double minute 2 (MDM2) and its homolog MDM4 are an integrated component of the network and have been implicated in regulating the stress responses and the maintenance of normal development and homeostasis of multiple somatic cell lineages. However, the regulatory role of MDM2 on p53 and stress responses in female germ cells remains undetermined. Here, we used the Cre-loxP system to delete Mdm2 in oocytes at different stages of folliculogenesis in mice. Mdm2 deletion resulted in a clear p53 nuclear accumulation in the oocytes and impeded fertilities with early follicular loss in mice, resembling human premature ovarian failure phenotypes. These phenotypes were fully rescued by concurrent deletion of p53 in mice. In addition, Nutlin-3, a small molecule compound that inhibited the binding of MDM2 to p53, also promoted p53-dependent oocyte death. Although cancer therapeutic agents 5-fluorouracil and doxorubicin could not induce a robust p53 activation in the wild-type oocytes, they induced p53 nuclear accumulation in the Mdm2 and Mdm4 double heterozygous oocytes. These results demonstrated a critical prosurvival role for MDM2 in the oocytes. Moreover, they suggested a more tightened and rigorous regulatory mode for the MDM2/MDM4-p53 network in female germ cells under stress situations.

p53 in the Myeloid Lineage Modulates an Inflammatory Microenvironment Limiting Initiation and Invasion of Intestinal Tumors.

Chronic inflammation promotes the development and progression of various epithelial tumors. Wild-type p53 suppresses inflammation, but it is unclear whether the role of p53 in suppression of inflammation is linked to its tumor suppression function. Here, we established mouse models of myeloid lineage-specific p53 deletion or activation to examine its role in inflammation-related intestinal tumorigenesis. Impaired p53 in the myeloid linage resulted in elevated levels of inflammatory mediators and stimulated adenoma initiation in Apc(Min/+) mice. In contrast, mice with mild p53 activation in the myeloid lineage attenuated the inflammatory response and were more resistant to intestinal tumor development and invasion, which were initiated through Apc(Min/+) mutation or carcinogen and promoted by colitis. Furthermore, p53 activation also suppressed alternative (M2) macrophage polarization together with c-MYC downregulation. Therefore, as a regulator of macrophage function, p53 is critical to protection against tumorigenesis in a non-cell-autonomous manner.

Interaction of HSP20 with a viral RdRp changes its sub-cellular localization and distribution pattern in plants.

Small heat shock proteins (sHSPs) perform a fundamental role in protecting cells against a wide array of stresses but their biological function during viral infection remains unknown. Rice stripe virus (RSV) causes a severe disease of rice in Eastern Asia. OsHSP20 and its homologue (NbHSP20) were used as baits in yeast two-hybrid (YTH) assays to screen an RSV cDNA library and were found to interact with the viral RNA-dependent RNA polymerase (RdRp) of RSV. Interactions were confirmed by pull-down and BiFC assays. Further analysis showed that the N-terminus (residues 1-296) of the RdRp was crucial for the interaction between the HSP20s and viral RdRp and responsible for the alteration of the sub-cellular localization and distribution pattern of HSP20s in protoplasts of rice and epidermal cells of Nicotiana benthamiana. This is the first report that a plant virus or a viral protein alters the expression pattern or sub-cellular distribution of sHSPs.

In vivo RNAi screen identifies candidate signaling genes required for collective cell migration in Drosophila ovary.

Collective migration of loosely or closely associated cell groups is prevalent in animal development, physiological events, and cancer metastasis. However, our understanding of the mechanisms of collective cell migration is incomplete. Drosophila border cells provide a powerful in vivo genetic model to study collective migration and identify essential genes for this process. Using border cell-specific RNAi-silencing in Drosophila, we knocked down 360 conserved signaling transduction genes in adult flies to identify essential pathways and genes for border cell migration. We uncovered a plethora of signaling genes, a large proportion of which had not been reported for border cells, including Rack1 (Receptor of activated C kinase) and brk (brinker), mad (mother against dpp), and sax (saxophone), which encode three components of TGF-ß signaling. The RNAi knock down phenotype was validated by clonal analysis of Rack1 mutants. Our data suggest that inhibition of Src activity by Rack1 may be important for border cell migration and cluster cohesion maintenance. Lastly, results from our screen not only would shed light on signaling pathways involved in collective migration during embryogenesis and organogenesis in general, but also could help our understanding for the functions of conserved human genes involved in cancer metastasis.