关键词： IQGAP1   neutrophils   CD11c   integrin  

摘要： IQ motif containing GTPase activating protein 1 (IQGAP1) is a protein scaffold that integrates signals regulating various cellular functions. Recently, utilizing proteomics as a discovery tool and co-immunoprecipitation as a validation method, we reported IQGAP1 as a potential ligand for CD11c, an adhesion molecule that was highly expressed in the intracellular components of neutrophils and regulated the maturation, survival, and function of neutrophils. To date, the role of IQGAP1 in inflammation and immune response is largely unknown. In this study, we reported the direct binding of CD11c with IQGAP1 through various methods. In addition, we investigated the role of IQGAP1 in neutrophil functions by using IQGAP1 knockout (KO) mice. We discovered that IQGAP1 deficiency led to impaired bone marrow neutrophil maturation, reactive oxygen species (ROS) generation, phagocytosis, and neutrophil extracellular traps formation. Thus, for the first time, we reported the essential role of IQGAP1 in neutrophil development.

关键词： Vascular endothelial glycocalyx   Endothelial cells   IQGAP1   Rivaroxaban   Oxidative stress   PI3K/Akt pathway  

摘要： Introduction: The vascular endothelial glycocalyx, crucial for blood vessel integrity and homeostasis, is vulnerable to oxidative stress, leading to endothelial dysfunction, which strongly correlates with cardiovascular disease (CVD). This study investigates the protective effects of rivaroxaban, a factor X inhibitor, on the glycocalyx under oxidative stress condition. Methods: We examined the impact of rivaroxaban on human umbilical vein endothelial cells exposed to acute and chronic H2O2-induced oxidative stress. Results: Rivaroxaban dose-dependently suppressed syndecan-1, a key component of the glycocalyx, shedding from cell surface, and enhanced protease-activated receptor (PAR)1-PAR2/phosphatidylinositol-3-kinase (PI3K)-dependent cell viability after acute induction of H2O2. This protective effect was linked to the translocation of IQGAP1, a scaffold protein that modulates the actin cytoskeleton, to the perinucleus from the cell membrane. Under chronic H2O2 treatments, rivaroxaban improves cell viability accompanied by an increase in hyaluronidase activities, aiding the turnover and remodeling of hyaluronic acid within the glycocalyx. Conclusion: We identify that rivaroxaban protects against oxidative stress-induced endothelial glycocalyx damage and cell viability through IQGAP1/PAR1-2/PI3K/Akt pathway, offering a potential to be a therapeutic target for CVD prevention.

关键词： Ischemic stroke   Platelet-related genes   IQGAP1   Diagnostic marker   Immune cells  

摘要： Introduction: Ischemic stroke (IS) is a complex illness resulting from a combination of numerous environmental and genetic risk factors. Recent reports have shed light on the vital role that platelets play in the pathophysiology of IS. Here, we aimed to explore the potential platelet-related genes in IS and investigate the effect of plateletrelated genes in the immune microenvironment of IS. Methods: The data of IS were retrieved from the Gene Expression Omnibus database. Firstly, we screened the platelet-related genes that were correlated with the onset of IS using differential expression analysis, enrichment analyses, and protein-protein interaction (PPI) network. Moreover, we analyzed the clinical value and functional information of platelet-related genes in IS. Finally, we explored the correlation between platelet-related genes and immune cells' infiltration. Results: Ten platelet-related genes that were correlated with the onset of IS were identified, among which IQGAP1 was located at the core of the PPI network. IQGAP1 was found to be expressed in the normal brain tissue and its expression was significantly elevated in IS samples. The area under the curve (AUC) values for IQGAP1 in both the GSE16561 and GSE58294 datasets were close to 1. IQGAP1 knockdown might increase OGD/R-induced HT22 cell viability. Additionally, FoxO signaling pathway, NOD-like receptor signaling pathway, Phagosome and Platelet activation pathways were significantly activated in IS patients with high IQGAP1 expression compared to those with low IQGAP1 expression. The IS patients in the IQGAP1high and IQGAP1low groups showed dramatically different proportions of immune cells and immune-related functions, and the IQGAP1 expression was correlated with the immune cell' infiltration in IS. Conclusions: In this study, we identified the IQGAP1 might serve as a potential diagnostic marker for IS, and the IQGAP1 expression was very relevant in determining the immune cell' infiltration in IS patien

关键词： cancer stem cells   small extracellular vesicles   pY105-PKM2   IQGAP1   drug resistance  

摘要： Rationale: Non-small cell lung cancer (NSCLC) is a predominant cause of cancer-related mortality, with its progression and treatment resistance significantly influenced by cancer stem cells (CSCs) and their complex intercellular communication mechanisms. Small extracellular vesicles (sEVs) have emerged as pivotal mediators of intercellular signaling, affecting tumor microenvironment modulation and therapeutic resistance. This study investigates the role of CSC-derived sEVs in transmitting stemness traits through the selective sorting of pyruvate kinase M2 phosphorylated at the Y105 site (pY105-PKM2), mediated by the adaptor protein IQGAP1, which supports CSC maintenance and drug resistance in NSCLC. Methods: In vitro and in vivo experiments, including proteomic and transcriptomic analyses, were conducted to identify key regulators of sEV-mediated signaling. Immunoprecipitation, proximity ligation assays, and immunofluorescence were used to examine the role of IQGAP1 in the sorting of pY105-PKM2 into sEVs. Functional assays, including sphere formation, chemoresistance tests, metabolic assessments, and cell cycle analysis, were conducted to evaluate the effects of sEV-mediated delivery of pY105-PKM2 on recipient cells. Additionally, immunohistochemistry and survival analysis were performed on tumor samples from NSCLC patients to establish clinical correlations. Results: We unveiled a novel mechanism by which CSC-derived sEVs transmit stemness traits to replenish the CSC pool in NSCLC. CSC-derived sEVs were enriched with pY105-PKM2, correlating with enhanced stemness, chemoresistance, and poor clinical outcomes. Mechanistically, IQGAP1 was identified as an adaptor facilitating the selective sorting of pY105-PKM2 into sEVs through interactions with the ESCRT component TSG101. Recipient cells treated with CSC-derived sEVs exhibited metabolic reprogramming, slower cell cycle progression, and enhanced chemoresistance. The synergistic role of IQGAP1 and pY105-PKM2 was confi

关键词： ANGPTL4   Cancer-associated fibroblasts   Chemosensitivity   Mitochondria   Prostate cancer  

摘要： Introduction Cancer-associated fibroblasts (CAFs) are a critical component of the tumor microenvironment, being implicated in enhancing tumor growth and fostering drug resistance. Nonetheless, the mechanisms underlying their function in prostate cancer (PCa) remain incompletely understood, which is essential for devising effective therapeutic strategies. Objectives The main objective of this study was to explore the mechanisms by which CAFs mediate PCa growth and chemoresistance. Methods We validated through data analysis and experimentation that CAFs significantly impact PCa cell proliferation and chemoresistance. Subsequently, we conducted a comprehensive proteomic analysis of the conditioned media from CAFs and PCa cells and identified angiopoietin-like protein 4 (ANGPTL4) as a key factor. We employed ELISA and multiplex immunofluorescence assays, all of which indicated that ANGPTL4 was primarily secreted by ***, we conducted metabolomics analysis, GST pull-down assays, Co-IP, and other experiments to explore the specific molecular mechanisms of ANGPTL4 and its precise effects on PCa cells. Through drug screening, we identified Quercetin 3-O-(6′-galactopyranosyl)-β-D-galactopyranoside (QGGP) as an effective inhibitor of CAFs function. Finally, we thoroughly assessed the therapeutic potential of QGGP both as a monotherapy and in combination with docetaxel in PCa cells Results We discovered that the extracrine factor ANGPTL4 is primarily expressed in CAFs in PCa. When ANGPTL4 binds to IQ motif-containing GTPase-activating protein 1 (IQGAP1) on the PCa cell membrane, it activates the Raf-MEK-ERK-PGC1α axis, promoting mitochondrial biogenesis and OXPHOS metabolism, and thereby facilitating PCa growth and chemoresistance. Furthermore, virtual and functional screening strategies identified QGGP as a specific inhibitor of IQGAP1 that promotes its degradation. Combined with docetaxel treatment, QGGP can reverse the effects of CAFs and improve the responsiveness of

关键词： 宫颈癌   半胱氨酸天冬氨酸蛋白酶1   IQ序列三磷酸鸟苷酶激活蛋白   血管内皮生长因子C  

摘要： 目的探究半胱氨酸天冬氨酸蛋白酶1(Caspase-1)、IQ序列三磷酸鸟苷酶激活蛋白(IQGAP1)及血管内皮生长因子C(VEGF-C)在宫颈癌中的表达对患者预后的预测价值。方法选取2021年6月—2022年6月于丽水市人民医院进行宫颈癌治疗的患者180例,经手术提取宫颈癌组织作为实验组,同时搜集距离癌组织3 cm处的癌旁组织作为对照组。采用免疫组化法测定Caspase-1、IQGAP1及VEGF-C阳性表达情况,并分析其与临床特征和预后之间的关系。结果癌变组织Caspase-1、IQGAP1及VEGF-C阳性表达率(66.67%、72.22%及61.11%)与癌旁组织(39.44%、42.22%及36.11%)比较均升高,差异均有统计学意义(χ^(2)=26.778、33.090及22.517,均P<0.05)。宫颈癌癌变组织中Caspase-1、IQGAP1及VEGF-C表达与分化程度、临床分期、淋巴结转移相关(均P<0.05)。将宫颈癌患者年龄、体质量指数、瘤体直径及组织类型等因素进行控制后,Caspase-1、IQGAP1及VEGF-C仍与分化程度、临床分期、淋巴结转移显著相关(均P<0.05)。受试者特征曲线(ROC)分析Caspase-1、IQGAP1、VEGF-C及联合检测对宫颈癌预后的预测价值,其曲下面积分别为0.707、0.752、0.795及0.911。结论Caspase-1、IQGAP1及VEGF-C在宫颈癌癌变组织中均呈现上调状态,并且其表达高低变化与分化程度、临床分期、淋巴结转移和预后情况之间具有一定联系,可能共同参与该疾病的发生、发展,并对患者的预后情况产生影响。

关键词： Cancer-predisposing variant   Cingulin   Epithelial-mesenchymal transition   IQGAP1   Rac1  

摘要： Background: Cingulin (CGN) is a pivotal cytoskeletal adaptor protein located at tight junctions. This study investigates the link between CGN mutation and increased cancer susceptibility through genetic and mechanistic analyses and proposes a potential targeted therapeutic approach. Methods: In a high-cancer-density family without known pathogenic variants, we performed tumor-targeted and germline whole-genome sequencing to identify novel cancer-associated variants. Subsequently, these variants were validated in a 222 cancer patient cohort, and CGN c.3560C > T was identified as a potential cancer-risk allele. Both wild-type (WT) (c.3560C > C) and variant (c.3560C > T) were transfected into cancer cell lines and incorporated into orthotopic xenograft mice model for evaluating their effects on cancer progression. Western blot, immunofluorescence analysis, migration and invasion assays, two-dimensional gel electrophoresis with mass spectrometry, immunoprecipitation assays, and siRNA applications were used to explore the biological consequence of CGN c.3560C > T. Results: In cancer cell lines and orthotopic animal models, CGN c.3560C > T enhanced tumor progression with reduced sensitivity to oxaliplatin compared to the CGN WT. The variant induced downregulation of epithelial marker, upregulation of mesenchymal marker and transcription factor, which converged to initiate epithelial-mesenchymal transition (EMT). Proteomic analysis was conducted to investigate the elements driving EMT in CGN c.3560C > T. This exploration unveiled overexpression of IQGAP1 induced by the variant, contrasting the levels observed in CGN WT. Immunoprecipitation assay confirmed a direct interaction between CGN and IQGAP1. IQGAP1 functions as a regulator of multiple GTPases, particularly the Rho family. This overexpressed IQGAP1 was consistently associated with the activation of Rac1, as evidenced by the analysis of the cancer cell line and clinical sample harboring CGN c.3560C > T. Notably, acti

关键词： NASH   MHCII antigen presentation   Hepatocytes   PDCD4   CIITA   NASH   non-alcoholic steatohepatitis   NAFL   non-alcoholic fatty liver   NAFLD   non-alcoholic fatty liver disease   CD   chow diet   MCD   methionine choline deficiency diet   HFHC   high-fat/high-cholesterol diet   HFFD   high-fat/high-fructose   HKO   hepatocyte-specific knockout   KO   knockout   PDCD4   programmed cell death 4   CIITA   class II major histocompatibility complex transactivator   MHCII   major histocompatibility complex class II   EH1L1   EH domain-binding protein 1-like protein 1   IQGAP1   IQ motif containing GTPase activating protein 1   OVA   ovalbumin   ITT   insulin tolerance test   GTT   glucose tolerance test   AUC   area under curve   PSR   picrosirius red   KEGG   Kyoto Encyclopedia of Genes and Genomes   CO-IP   CO-immunoprecipitation   AAV8   adeno-associated virus type 8   FPKM   Fragments Per Kilobase of exon model per Million mapped fragments   ALT   alanine aminotransferase   AST   aspartate aminotransferase   PA   palmitic acid   OA   oleic acid   NC   normal chow   WT   wild type   TNF   tumor necrosis factor   RIP   RNA immunoprecipitation   IHC   immunohistochemistry   RBD   RNA binding domain   APCs   antigen-presenting cells  

摘要： Nonalcoholic steatohepatitis (NASH) is a primary cause of liver cirrhosis and hepatocellular carcinoma, presenting a significant and unmet medical challenge. The necessity to investigate the molecular mechanisms underlying NASH is highlighted by the observed decrease in programmed cell death 4 (PDCD4) expression in NASH patients, suggesting that PDCD4 may play a protective role in maintaining liver health. In this study, we identify PDCD4 as a natural inhibitor of NASH development in mice. The absence of PDCD4 leads to the spontaneous progression of NASH. Notably, PDCD4-deficient hepatocytes display elevated major histocompatibility complex class II (MHCII) expression due to CIITA activation, indicating that PCDC4 prevents the abnormal transformation of hepatocytes into antigen-presenting cells (APCs). Cell co-culture experiments reveal that hepatocytes lacking PDCD4, which resemble APCs, can directly activate CD4 + T cells by presenting multiple peptides, resulting in the release of inflammatory factors. Additionally, both cellular and animal studies show that CIITA promotes lipid accumulation in hepatocytes and exacerbates NASH progression. In summary, our findings reveal a novel role of PDCD4 in regulating CIITA and MHCII expression during NASH development, offering new therapeutic approaches for NASH treatment.