关键词： morphine dependence   mir-124   IQGAP1   addictive   cognition  

摘要： BackgroundLong-term excessive use of morphine leads to addictive diseases and affects cognitive function. Cognitive performance is associated with genetic ***-124 plays a critical regulatory role in neurogenesis, synaptic development, brain plasticity, and the use of addictive substances. As a scaffold protein, IQGAP1 affects learning and memory dose-dependent. However, the role of miR-124 and its target protein as potential addiction biomarkers and the impact on cognitive function have not been fully explored. MethodA total of 40 patients with morphine dependence and 40 cases of healthy people were recruited. We collected basic and clinical information about the two groups. The Generalized Anxiety Disorder Scale (GAD-7), Patient Health Questionnaire-9(PHQ-9), Montreal Cognition Assessment Scale (MoCA), Pittsburgh Sleep Quality Index (PSQI) were used to assess the severity of depression, anxiety, depressive symptoms, cognitive dysfunction, and sleep quality. ResultsCompared to the control group, the morphine-dependent group had higher GAD-7, PHQ-9, PSQI scores, and more elevated miR-124 levels but lower MOCA scores and IQGAP1 levels. MiR-124, IQGAP1, the average intake last year were related to OASI ***-124, IQGAP1, PHQ-9 were associated with MOCA scores. In the multiple regression model, the levels of miR-124 and IQGAP1 were independent factors influencing the severity of morphine dependence. The level of miR-124 was an independent factor influencing the severity of cognitive impairment in patients with morphine dependence. In addition, the luciferase report confirmed that IQGAP1 mRNA is the direct target of miR-124. ConclusionMiR-124 and its target protein IQGAP1 are involved in the regulation of addiction and cognitive function in patients with morphine dependence.

关键词： Cdc42   F-actin   IQGAP1   Rac1   bone marrow mesenchymal stromal cells   liver fibrosis   migration   sphingosine 1-phosphate receptor 3  

摘要： IQ motif-containing guanosine triphosphatase (GTPase)-activating protein 1 (IQGAP1) is a cytosolic scaffolding protein involved in cell migration. Our previous studies suggest sphingosine 1-phosphate (S1P) triggers bone marrow (BM) mesenchymal stromal cells (BMSCs) to damaged liver, thereby promoting liver fibrosis. However, the role of IQGAP1 in S1P-induced BMSC migration and liver fibrogenesis remains unclear. Chimeric mice of BM cell labeled by EGFP were used to build methionine-choline-deficient and high-fat (MCDHF)-diet-induced mouse liver fibrosis. IQGAP1 small interfering RNA (siRNA) was utilized to silence IQGAP1 in vivo. IQGAP1 expression is significantly elevated in MCDHF-diet-induced mouse fibrotic livers. Positive correlations are presented between IQGAP1 and fibrosis hallmarks expressions in human and mouse fibrotic livers. In vitro, depressing IQGAP1 expression blocks S1P-induced motility and cytoskeleton remodeling of BMSCs. S1P facilitates IQGAP1 aggregating to plasma membrane via S1P receptor 3 (S1PR(3)) and Cdc42/Rac1. In addition, IQGAP1 binds to Cdc42/Rac1, regulating S1P-induced activation of Cdc42/Rac1 and mediating BMSC migration in concert. In vivo, silencing IQGAP1 reduces the recruitment of BMSCs to impaired liver and effectively alleviates liver fibrosis induced by MCDHF diet. Together, silencing IQGAP1 relieves liver fibrosis by blocking BMSC migration, providing an effective therapeutic strategy for liver fibrosis.

摘要： IQGAP1 is a multidomain scaffold protein that coordinates the direction and impact of multiple signaling pathways by scaffolding its various binding partners. However, the spatial and temporal resolution of IQGAP1 scaffolding remains unclear. Here, we use fluorescence imaging and correlation methods that allow for real-time live-cell changes in IQGAP1 localization and complex formation during signaling. We find that IQGAP1 and PIPKI gamma interact on both the plasma membrane and in cytosol. Epidermal growth factor (EGF) stimulation, which can initiate cytoskeletal changes, drives the movement of the cytosolic pool toward the plasma membrane to promote cytoskeletal changes. We also observe that a significant population of cytosolic IQGAP1-PIPKI gamma complexes localize to early endosomes, and in some instances form aggregated clusters which become highly mobile upon EGF stimulation. Our imaging studies show that PIPKI gamma and PI3K bind simultaneously to IQGAP1, which may accelerate conversion of PI4P to PI(3,4,5)P-3 that is required for cytoskeletal changes. Additionally, we find that IQGAP1 is responsible for PIPKI gamma association with two proteins associated with cytoskeletal changes, talin and Cdc42, during EGF stimulation. These results directly show that IQGAP1 provides a physical link between phosphoinositides (through PIPKI gamma), focal adhesion formation (through talin), and cytoskeletal reorganization (through Cdc42) upon EGF stimulation. Taken together, our results support the importance of IQGAP1 in regulating cell migration by linking phosphoinositide lipid signaling with cytoskeletal reorganization.

关键词： fibrosis   foreign body response   inflammation   mechanotransduction  

摘要： The aim of this study was to further elucidate the molecular mechanisms that mediate pathologic foreign body response (FBR) to biomedical implants. The longevity of biomedical implants is limited by the FBR, which leads to implant failure and patient morbidity. Since the specific molecular mechanisms underlying fibrotic responses to biomedical implants have yet to be fully described, there are currently no targeted approaches to reduce pathologic FBR. We utilized proteomics analysis of human FBR samples to identify potential molecular targets for therapeutic inhibition of FBR. We then employed a murine model of FBR to further evaluate the role of this potential target. We performed histological and immunohistochemical analysis on the murine FBR capsule tissue, as well as single-cell RNA sequencing (scRNA-seq) on cells isolated from the capsules. We identified IQ motif containing GTPase activating protein 1 (IQGAP1) as the most promising of several targets, serving as a central molecular mediator in human and murine FBR compared to control subcutaneous tissue. IQGAP1-deficient mice displayed a significantly reduced FBR compared to wild-type mice as evidenced by lower levels of collagen deposition and maturity. Our scRNA-seq analysis revealed that decreasing IQGAP1 resulted in diminished transcription of mechanotransduction, inflammation, and fibrosis-related genes, which was confirmed on the protein level with immunofluorescent staining. The deficiency of IQGAP1 significantly attenuates FBR by deactivating downstream mechanotransduction signaling, inflammation, and fibrotic pathways. IQGAP1 may be a promising target for rational therapeutic design to mitigate pathologic FBR around biomedical implants.

摘要： IQGAP is a conserved family of actin-binding proteins with essential roles in cell motility, cytokinesis, and cell adhesion, yet there remains a limited understanding of how IQGAP proteins directly influence actin filament dynamics. To close this gap, we used single-molecule and single-filament total internal reflection fluorescence microscopy to observe IQGAP regulating actin dynamics in real time. To our knowledge, this is the first study to do so. Our results demonstrate that full-length human IQGAP1 forms dimers that stably bind to actin filament sides and transiently cap barbed ends. These interactions organize filaments into thin bundles, suppress barbed end growth, and inhibit filament disassembly. Surprisingly, each activity depends on distinct combinations of IQGAP1 domains and/or dimerization, suggesting that different mechanisms underlie each functional effect on actin. These observations have important implications for how IQGAP functions as an actin regulator in vivo and how it may be regulated in different biological settings.

关键词： AmotL2   IQGAP1   and FKBP51   angiogenesis   glioblastoma stem cells   scaffold proteins   stem cell niche   stemness   tumor heterogeneity   tumor immune infiltrate   tumor microenvironment  

摘要： Glioma stem cells (GSCs) live in a continuous process of stemness reprogramming to achieve specific cell commitment within the so-called GSC niches, specifically located in periarteriolar regions. In this review, we analyze the expression levels, cellular and subcellular location, and role of three scaffold proteins (IQGAP1, FKBP51, and AmotL2) in GSC niches. Scaffold proteins contribute to cell differentiation, migration, and angiogenesis in glioblastoma. It could be of diagnostic interest for establishing stages, for therapeutic targets, and for improving glioblastoma prognosis, which is still at the experimental level.

关键词： HIV-1   HIV-1 Gag   CDC42   IQGAP1   ARP2   3   F-Actin   budding   Diaph2  

摘要： F-Actin remodeling is important for the spread of HIV via cell-cell contacts;however, the mechanisms by which HIV corrupts the actin cytoskeleton are poorly understood. Through live cell imaging and focused ion beam scanning electron microscopy (FIB-SEM), we observed F-Actin structures that exhibit strong positive curvature to be enriched for HIV buds. Virion proteomics, gene silencing, and viral mutagenesis supported a Cdc42-IQGAP1-Arp2/3 pathway as the primary intersection of HIV budding, membrane curvature and F-Actin regulation. Whilst HIV egress activated the Cdc42-Arp2/3 filopodial pathway, this came at the expense of cell-free viral release. Importantly, release could be rescued by cell-cell contact, provided Cdc42 and IQGAP1 were present. From these observations, we conclude that a proportion out-going HIV has corrupted a central F-Actin node that enables initial coupling of HIV buds to cortical F-Actin to place HIV at the leading cell edge. Whilst this initially prevents particle release, the maturation of cell-cell contacts signals back to this F-Actin node to enable viral release & subsequent infection of the contacting cell.

关键词： 垂体腺瘤   侵袭性   circ-IQGAP1   circ-ZNF79   JAK2   STAT3  

摘要： 目的:本研究基于垂体腺瘤高通量测序结果,筛选侵袭性垂体腺瘤相关基因circ-IQGAP1、circ-ZNF79,检测circ-IQGAP1、circ-ZNF79及肿瘤热门通路蛋白JAK2、STAT3在垂体腺瘤中的表达情况,剖析目的基因与JAK2/STAT3通路对垂体腺瘤侵袭性的影响,探索与垂体腺瘤侵袭性生物学行为相关的潜在生物标志物,为寻找有助于垂体腺瘤早期诊断、治疗及预后评估的新方法做一些有益的工作。方法:本课题自2020年06月至2021年03月期间于河北大学附属医院神经外科收集共计27例因无功能性垂体腺瘤(根据术前实验室检查及术后病理结果诊断)行神经内镜辅助下经鼻-蝶入路垂体腺瘤切除术的患者的垂体腺瘤组织样本(黄豆大小)。根据术前影像学检查提示,27例垂体腺瘤患者中有侵袭性垂体腺瘤患者12例,非侵袭性垂体腺瘤患者15例,采用随机数字法各纳入8例进行研究,若后期经总RNA质检不合格,再随机从剩余样本中增补。所有患者术前均未行相关手术、放化疗等其它治疗。按照垂体腺瘤的侵袭性与否,将所取的16例垂体腺瘤组织样本进行分组,其中8例侵袭性垂体腺瘤样本作为侵袭组(实验组),8例非侵袭性垂体腺瘤样本作为非侵袭组(对照组)。采用实时荧光定量PCR法(RT-PCR)检测circ-IQGAP1、circ-ZNF79在实验组和对照组垂体腺瘤组织中的相对表达情况,免疫组织化学染色方法(IHC)检测通路蛋白JAK2、STAT3在实验组和对照组垂体腺瘤组织中的相对表达情况。整理数据结果并进行统计学处理,分析目的基因、蛋白在实验组和对照组中表达的差异性,得出结论,上述研究方案经过河北大学附属医院伦理委员会批准实施。结果:1.侵袭组中circ-IQGAP1相对表达水平(0.96±0.51)显著低于非侵袭性组(2.12±0.72),(P<0.05)。2.侵袭组中circ-ZNF79相对表达水平(3.19±0.87)显著高于非侵袭组(1.34±0.71),(P<0.05)。3.侵袭性垂体腺瘤组织样本中JAK2高表达4例,表达率为50.0%;非侵袭性垂体腺瘤组织样本中JAK2高表达1例,表达率为12.5%。两组样本表达强度存在差异,侵袭性组比非侵袭性组表达强度显著增强(Z=-4.424 P<0.05)。4.侵袭性垂体腺瘤组织样本中STAT3高表达3例,表达率为37.5%;非侵袭性垂体腺瘤组织样本中STAT3高表达1例,表达率为12.5%。两组样本表达强度存在差异,侵袭性组比非侵袭性组表达强度显著增强(Z=-3.682 P<0.05)。5.在垂体腺瘤中,随着JAK2的表达水平上调,STAT3也随之上调。JAK2与ATAT3两者表达呈正相关(r=0.313 P<0.001),差异有统计学意义。结论:***-IQGAP1、circ-ZNF79、JAK2及STAT3在侵袭性垂体腺瘤和非侵袭性垂体腺瘤中均有表达。***-IQGAP1在侵袭性垂体腺瘤中相对表达水平显著低于非侵袭性垂体腺瘤,因此circ-IQGAP1可能抑制了垂体腺瘤侵袭性行为的发生。***-ZNF79在侵袭性垂体腺瘤中相对表达水平显著高于非侵袭性垂体腺瘤,因此circ-ZNF79可能促进了垂体腺瘤侵袭性行为的发生。4.与非侵袭性垂体腺瘤相比,JAK2、STAT3在侵袭性垂体腺瘤中表达强度明显增强,且表达水平呈正相关,因此JAK2/STAT3信号通路的激活可能促进了垂体腺瘤侵袭性行为的发生。