scholarly journals Flow-dependent YAP/TAZ activities regulate endothelial phenotypes and atherosclerosis

2016 ◽  
Vol 113 (41) ◽  
pp. 11525-11530 ◽  
Author(s):  
Kuei-Chun Wang ◽  
Yi-Ting Yeh ◽  
Phu Nguyen ◽  
Elaine Limqueco ◽  
Jocelyn Lopez ◽  
...  
Keyword(s):  
Target Genes ◽  
Critical Role ◽  
Atherosclerotic Lesion ◽  
Tissue Growth ◽  
Binding Motif ◽  
Disturbed Flow ◽  
Atherosclerotic Lesions ◽  
En Face

The focal nature of atherosclerotic lesions suggests an important role of local hemodynamic environment. Recent studies have demonstrated significant roles of Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) in mediating mechanotransduction and vascular homeostasis. The objective of this study is to investigate the functional role of YAP/TAZ in the flow regulation of atheroprone endothelial phenotypes and the consequential development of atherosclerotic lesions. We found that exposure of cultured endothelial cells (ECs) to the atheroprone disturbed flow resulted in YAP/TAZ activation and translocation into EC nucleus to up-regulate the target genes, including cysteine-rich angiogenic inducer 61 (CYR61), connective tissue growth factor (CTGF), and ankyrin repeat domain 1 (ANKRD1). In contrast, the athero-protective laminar flow suppressed YAP/TAZ activities. En face analysis of mouse arteries demonstrated an increased nuclear localization of YAP/TAZ and elevated levels of the target genes in the endothelium in atheroprone areas compared with athero-protective areas. YAP/TAZ knockdown significantly attenuated the disturbed flow induction of EC proliferative and proinflammatory phenotypes, whereas overexpression of constitutively active YAP was sufficient to promote EC proliferation and inflammation. In addition, treatment with statin, an antiatherosclerotic drug, inhibited YAP/TAZ activities to diminish the disturbed flow-induced proliferation and inflammation. In vivo blockade of YAP/TAZ translation by morpholino oligos significantly reduced endothelial inflammation and the size of atherosclerotic lesions. Our results demonstrate a critical role of the activation of YAP/TAZ by disturbed flow in promoting atheroprone phenotypes and atherosclerotic lesion development. Therefore, inhibition of YAP/TAZ activation is a promising athero-protective therapeutic strategy.

scholarly journals NUSAP1 Promotes Gastric Cancer Progression Through Regulation of Yap Stability

2020 ◽  
Author(s):  
Hui Guo ◽  
Jianping Zou ◽  
Ling Zhou ◽  
Yan He ◽  
Miao Feng ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cancer Progression ◽  
Target Genes ◽  
Hippo Pathway ◽  
Critical Role ◽  
Xenograft Model ◽  
Migration And Invasion

Abstract Background:Nucleolar and spindle associated protein (NUSAP1) is involved in tumor initiation, progression and metastasis. However, there are limited studies regarding the role of NUSAP1 in gastric cancer (GC). Methods: The expression profile and clinical significance of NUSAP1 in GC were analysed in online database using GEPIA, Oncomine and KM plotter, which was further confirmed in clinical specimens.The functional role of NUSAP1 were detected utilizing in vitro and in vivo assays. Western blotting, qRT-PCR, the cycloheximide-chase, immunofluorescence staining and Co-immunoprecipitaion (Co-IP) assays were performed to explore the possible molecular mechanism by which NUSAP1 stabilizes YAP protein. Results:In this study, we found that the expression of NUSAP1 was upregulated in GC tissues and correlates closely with progression and prognosis. Additionally, abnormal NUSAP1 expression promoted malignant behaviors of GC cells in vitro and in a xenograft model. Mechanistically, we discovered that NUSAP1 physically interacts with YAP and furthermore stabilizes YAP protein expression, which induces the transcription of Hippo pathway downstream target genes. Furthermore, the effects of NUSAP1 on GC cell growth, migration and invasion were mainly mediated by YAP. Conclusions:Our data demonstrates that the novel NUSAP1-YAP axis exerts an critical role in GC tumorigenesis and progression, and therefore could provide a novel therapeutic target for GC treatment.

scholarly journals The Phospholipid Transfer Protein Gene Is a Liver X Receptor Target Expressed by Macrophages in Atherosclerotic Lesions

2003 ◽  
Vol 23 (6) ◽  
pp. 2182-2191 ◽  
Author(s):  
Bryan A. Laffitte ◽  
Sean B. Joseph ◽  
Mingyi Chen ◽  
Antonio Castrillo ◽  
Joyce Repa ◽  
...  
Keyword(s):  
Target Genes ◽  
Critical Role ◽  
Lipoprotein Metabolism ◽  
Plasma Phospholipid ◽  
Phospholipid Transfer Protein ◽  
Transfer Protein ◽  
Atherosclerotic Lesions ◽  
Phospholipid Transfer

ABSTRACT The liver X receptors (LXRs) are members of the nuclear receptor superfamily that are activated by oxysterols. In response to ligand binding, LXRs regulate a variety of genes involved in the catabolism, transport, and uptake of cholesterol and its metabolites. Here we demonstrate that LXRs also regulate plasma lipoprotein metabolism through control of the phospholipid transfer protein (PLTP) gene. LXR ligands induce the expression of PLTP in cultured HepG2 cells and mouse liver in vivo in a coordinate manner with known LXR target genes. Moreover, plasma phospholipid transfer activity is increased in mice treated with the synthetic LXR ligand GW3965. Unexpectedly, PLTP expression was also highly inducible by LXR in macrophages, a cell type not previously recognized to express this enzyme. The ability of synthetic and oxysterol ligands to regulate PLTP mRNA in macrophages and liver is lost in animals lacking both LXRα and LXRβ, confirming the critical role of these receptors. We further demonstrate that the PLTP promoter contains a high-affinity LXR response element that is bound by LXR/RXR heterodimers in vitro and is activated by LXR/RXR in transient-transfection studies. Finally, immunohistochemistry studies reveal that PLTP is highly expressed by macrophages within human atherosclerotic lesions, suggesting a potential role for this enzyme in lipid-loaded macrophages. These studies outline a novel pathway whereby LXR and its ligands may modulate lipoprotein metabolism.

Abstract 164: Endothelial Gab1 Limits Vascular Remodeling and Atherosclerosis Through Inhibition of Endothelial Inflammation

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Suowen Xu ◽  
Meimei Yin ◽  
Jingjing Zhao ◽  
Marina Koroleva ◽  
Zheng Gen Jin
Keyword(s):  
Adhesion Molecule ◽  
Vascular Remodeling ◽  
Fluid Shear Stress ◽  
Atherosclerotic Lesion ◽  
Monocyte Adhesion ◽  
Disturbed Flow ◽  
Apoe Ko Mice ◽  
Apoe Ko

Objective: We have previously shown that docking protein Grb2-associated binder 1 (Gab1) is a mechano-effector protein in response to fluid shear stress and regulates postnatal angiogenesis. The aim of this study was to determine the in vivo role of endothelial Gab1 in flow-mediated vascular remodeling and atherosclerosis and explore the underlying mechanisms. Methods and Results: To determine the role of endothelial Gab1 in disturbed flow-induced vascular remodeling in vivo, we performed partial carotid artery ligation in Gab1 endothelium-restricted knockout (Gab1-ecKO) mice and wild-type (WT) littermates, and we observed that Gab1-ecKO mice resulted in increased intima-media thickness. To examine the role of endothelial Gab1 in atherosclerosis, we next crossed Gab1-ecKO mice with ApoE KO mice. After partial ligation, Gab1-ecKO;ApoE KO mice under high fat diet showed increased atherosclerotic lesion size compared to Gab1-WT;ApoE KO mice. The levels of proatherogenic genes intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), and leukocyte infiltration were all increased in Gab1-ecKO;ApoE KO mice. Using loss- and gain-of-function studies in cultured human endothelial cells (ECs), we found that Gab1 depletion by siRNA augmented monocyte adhesion to ECs by increasing ICAM-1 and VCAM-1 expression in response to the proinflammatory cytokine TNF-α. Conversely, adenoviral overexpression of Gab1 inhibited TNFα-induced monocyte adhesion to ECs and upregulation of ICAM-1 and VCAM-1 in ECs. Conclusions: These results demonstrate that endothelial Gab1 represses disturbed flow-induced vascular remodeling and atherogenesis through inhibition of vascular inflammation. Our findings suggest that Gab1 activation might represent novel approaches for the treatment of vascular diseases, including intimal hyperplasia and atherosclerosis.

Abstract 17184: Nearly One Third of GWAS CAD Are Putative SMC Klf4 or Oct4 Targets in Advanced Atherosclerotic Lesions

Circulation ◽  
2018 ◽  
Vol 138 (Suppl_1) ◽  
Author(s):  
Gabriel F Alencar ◽  
Ryan Haskins ◽  
Vamsidhar M Venkata ◽  
Johan Bjorkegren ◽  
Stefan Bekiranov ◽  
...  
Keyword(s):  
Target Genes ◽  
Critical Role ◽  
Atherosclerotic Lesion ◽  
Protective Role ◽  
Lineage Tracing ◽  
Rna Seq ◽  
Plaque Instability ◽  
Atherosclerotic Lesions ◽  
Significant Gene ◽  
Migration Pathways

Atherosclerosis is a disease of chronic inflammation and the leading cause of morbidity and mortality worldwide. Despite decades of research, our understanding of the mechanisms regulating plaque stability remains poor. Until recently, smooth muscle cells (SMCs) were thought to play an athero-protective role in lesion pathogenesis. However, rigorous lineage tracing has shown a significant portion (>80%) of SMC-derived cells within an advanced atherosclerotic lesion did not express detectable SMC markers. Furthermore, SMC-specific conditional KO of Klf4 resulted in reduction of several indices of plaque instability and SMC-derived macrophage-like cells. In contrast, conditional KO of Oct4 in SMCs presented a reduction of SMC and increased of Lgals3+ cells within lesions, as well as increase of several indices of plaque instability. Taken together, SMCs can have a beneficial or detrimental effect in lesion pathogenesis. Hypothesis: Combinatorial analysis of Oct4/Klf4 ChIP-seq and RNA-seq of advanced atherosclerotic lesions from our SMC-Klf4 and SMC-Oct4 mice provide a unique opportunity to identify genes that play a critical role in regulating beneficial or detrimental changes in SMC phenotype. Results: SMC-Oct4 target genes are enriched for migration pathways, while SMC-Klf4 target genes are enriched for inflammation pathways. Further, atherosclerosis pathway, among others, presented significant opposite patterns (SMC-Oct4-KO up-regulation and SMC-Klf4-KO down-regulation), and presented strong significant gene anti-correlation, corroborating our phenotypic observations. Remarkably, we cross-reference our ChIP-seq datasets with CAD GWAS and found that 54 of the 161 human loci were either Klf4 and/or Oct4 SMC targets, highly suggesting that CAD GWAS genes might be affecting SMC function in lesion development/pathogenesis. To validate our results, we used the STARNET dataset, and we observed that both Oct4 and Klf4 are significantly up-regulated in aorta of CAD patients compared to controls. In addition, co-expression analysis shows that one of the Klf4 network is highly related to human GWAS CAD, including genes such as LDLR, APOE, PCSK9, TRIB1, and others. Surprisingly, more than 35% of genes in this network also are present in our SMC Klf4 ChIP-seq dataset. Conclusions: our results suggests that: late stage atherosclerotic lesions of mouse and humans seems to be more similar than previously thought; and nearly 1/3 of CAD GWAS loci appear to be affecting SMC function and are potentially Klf4/Oct4-dependent.

scholarly journals Plasmin-mediated fibrinolysis enables macrophage migration in a murine model of inflammation

Blood ◽  
2019 ◽  
Vol 134 (3) ◽  
pp. 291-303 ◽  
Author(s):  
Lakmali Munasinghage Silva ◽  
Andrew Gary Lum ◽  
Collin Tran ◽  
Molly W. Shaw ◽  
Zhen Gao ◽  
...  
Keyword(s):  
Peritoneal Cavity ◽  
Critical Role ◽  
Binding Motif ◽  
Macrophage Migration ◽  
Chemotactic Migration ◽  
Migration Of Macrophages ◽  
Deficient Mice

Abstract Efficient migration of macrophages to sites of inflammation requires cell surface–bound plasmin(ogen). Here, we investigated the mechanisms underlying the deficits of plasmin(ogen)-mediated macrophage migration in 2 models: murine thioglycollate-induced peritonitis and in vitro macrophage migration. As previously reported, macrophage migration into the peritoneal cavity of mice in response to thioglycollate was significantly impaired in the absence of plasminogen. Fibrin(ogen) deposition was noted in the peritoneal cavity in response to thioglycollate, with a significant increase in fibrin(ogen) in the plasminogen-deficient mice. Interestingly, macrophage migration was restored in plasminogen-deficient mice by simultaneous imposition of fibrinogen deficiency. Consistent with this in vivo finding, chemotactic migration of cultured macrophages through a fibrin matrix did not occur in the absence of plasminogen. The macrophage requirement for plasmin-mediated fibrinolysis, both in vivo and in vitro, was negated by deletion of the major myeloid integrin αMβ2-binding motif on the γ chain of fibrin(ogen). The study identifies a critical role of fibrinolysis in macrophage migration, presumably through the alleviation of migratory constraints imposed by the interaction of leukocytes with fibrin(ogen) through the integrin αMβ2 receptor.

Therapeutic window for Wnt-driven cancers: Role of Porcupine inhibitor

2014 ◽  
Vol 2 (2) ◽  
pp. 78-86
Author(s):  
Jon A Harris ◽  
Edward A Beutler
Keyword(s):  
Wnt Signaling ◽  
Target Genes ◽  
Critical Role ◽  
Signal Transduction Pathway ◽  
Predictive Biomarkers ◽  
Human Head ◽  
Therapeutic Window ◽  
Multiple Tumor

Wnt signaling plays a critical role in carcinogenesis; many studies over the last two decades have identified numerous signaling components that have helped to build a molecular framework for the many branches of the Wnt signal transduction pathway. However, the diverse function, integration and specificity of the Wnt signaling are still unclear. The success of Wnt pathway inhibitors has been limited for long-time by the narrow therapeutic window afforded by the requirement for Wnt signaling in normal tissue homeostasis and the lack of predictive biomarkers of response. Porcupine is a membrane bound O-acyltransferase enzyme that is required for and dedicated to palmitoylating Wnt ligands, a necessary step in the process of Wnt ligand secretion. Inhibition of Porcupine blocks Wnt dependent activities, including LRP6 phosphorylation and the expression of Wnt target genes, such as Axin2, which in turn reduces the growth of cancer cells dependent on autocrine or paracrine Wnt signaling. LGK974 is a highly potent, selective and orally bioavailable Porcupine inhibitor and efficacious in multiple tumor models at well-tolerated doses in vivo, including murine and rat mechanistic breast cancer models driven by MMTV–Wnt1, a human head and neck squamous cell carcinoma model (HN30) and RNF43-mutant pancreatic xenograft models. In this review, we will summarize the most recent advances in our understanding of these Wnt signaling pathways and the role of Porcupine in inhibition of Wnt activity.

A Role of Poly (ADP-Ribose) Polymerase in NF- B Transcriptional Activation

1999 ◽  
Vol 380 (7-8) ◽  
pp. 953-959 ◽  
Author(s):  
P. O. Hassa ◽  
M. O. Hottiger
Keyword(s):  
Transcriptional Activation ◽  
Target Genes ◽  
Inflammatory Responses ◽  
Critical Role ◽  
Gene Activation ◽  
Nuclear Complex ◽  
Activation Cascade ◽  
Ltr Promoter

AbstractThe transcription factor NF-κB plays a critical role in immune and inflammatory responses. Here we show that poly (ADP ribose) polymerase (PARP) is required for specific NF-κB transcriptional activationin vivo. The activation of the HIV-LTR promoter and an NF-κBdependent artificial promoter was drastically reduced in PARP (_/_) cells, independently of the signaling pathway through which NF-bB was induced. Furthermore NF-κB-dependent gene activation was restoredin vivoby the expression of PARP in PARP (_/_) cells. Finally, we show that both NF-κB and PARP formed a stable immunoprecipitable nuclear complex. This interaction did not need DNA binding. Our results suggest that PARP is an important cofactor in the activation cascade of NF-κB-dependent target genes.

scholarly journals LncRNA CBR3-AS1 Regulates of Breast Cancer Drug Sensitivity as a Competing Endogenous RNA Through the JNK1/MEK4‑Mediated MAPK Signal Pathway

2020 ◽  
Author(s):  
Ming Zhang ◽  
Yan Wang ◽  
Longyang Jiang ◽  
Xinyue Song ◽  
Ang Zheng ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Noncoding Rna ◽  
Target Genes ◽  
Mapk Pathway ◽  
Critical Role ◽  
Luciferase Reporter ◽  
Cancer Drug ◽  
Clinical Prognosis

Abstract Background: Adriamycin (ADR) resistance is one of the main obstacles to improve the clinical prognosis of breast cancer (BRCA) patients. Long non-coding RNAs (lncRNAs) can regulate cell behavior, but the role of these RNAs in anti ADR of BRCA remains unclear. Here we aim to investigate the imbalance of a particular long noncoding RNA, lncRNA CBR3 antisense RNA 1 (CBR3-AS1), and its role in ADR resistance.Methods: Microarray analysis of ADR-resistant BRCA cells was performed to identify CBR3-AS1. CCK8 assay and colony formation assay were used to detect the sensitivity of BRCA cells to ADR. Dual-luciferase reporter, RNA pull down, IHC and Western blot were used to verify the relationship between CBR3-AS1, miRNA and target genes. In vivo, the effect of CBR3-AS1 on BRCA resistance was observed by xenograft tumor model. The role of CBR3-AS1 in influencing ADR sensitivity was verified by clinical BRCA specimens, TCGA, CCLE, and GDSC databases.Results: Here, we found that lncRNA CBR3-AS1 was significantly increased in BRCA tissues and was closely correlated with poor prognosis. CBR3-AS1 overexpression promoted ADR resistance in BRCA cells in vitro and in vivo. Mechanistically, we identified that CBR3-AS1 functioned as a competitive endogenous RNA by acting as a molecular sponge of miR-25-3p. MEK4 and JNK1 of MAPK pathway were the direct downstream proteins of CBR3-AS1 / miR-25-3p axis in BRCA cells.Conclusions: In summary, our findings demonstrate that CBR3-AS1 plays a critical role in the chemotherapy resistance of BRCA by mediating the miR-25-3p, MEK4/JNK1 regulatory axis. The potential of CBR3-AS1 as an oncogene and therapeutic biomarker of BRCA was identified.

scholarly journals The role of the PZP domain of AF10 in acute leukemia driven by AF10 translocations

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Brianna J. Klein ◽  
Anagha Deshpande ◽  
Khan L. Cox ◽  
Fan Xuan ◽  
Mohamad Zandian ◽  
...  
Keyword(s):  
Critical Role ◽  
Cellular Transformation ◽  
Acute Leukemias ◽  
Hematopoietic Stem ◽  
Nucleosome Core ◽  
Stem And Progenitor Cells ◽  
Transforming Activity

AbstractChromosomal translocations of the AF10 (or MLLT10) gene are frequently found in acute leukemias. Here, we show that the PZP domain of AF10 (AF10PZP), which is consistently impaired or deleted in leukemogenic AF10 translocations, plays a critical role in blocking malignant transformation. Incorporation of functional AF10PZP into the leukemogenic CALM-AF10 fusion prevents the transforming activity of the fusion in bone marrow-derived hematopoietic stem and progenitor cells in vitro and in vivo and abrogates CALM-AF10-mediated leukemogenesis in vivo. Crystallographic, biochemical and mutagenesis studies reveal that AF10PZP binds to the nucleosome core particle through multivalent contacts with the histone H3 tail and DNA and associates with chromatin in cells, colocalizing with active methylation marks and discriminating against the repressive H3K27me3 mark. AF10PZP promotes nuclear localization of CALM-AF10 and is required for association with chromatin. Our data indicate that the disruption of AF10PZP function in the CALM-AF10 fusion directly leads to transformation, whereas the inclusion of AF10PZP downregulates Hoxa genes and reverses cellular transformation. Our findings highlight the molecular mechanism by which AF10 targets chromatin and suggest a model for the AF10PZP-dependent CALM-AF10-mediated leukemogenesis.

scholarly journals Splicing factor SRSF1 promotes breast cancer progression via oncogenic splice switching of PTPMT1

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Jun-Xian Du ◽  
Yi-Hong Luo ◽  
Si-Jia Zhang ◽  
Biao Wang ◽  
Cong Chen ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Progression ◽  
High Risk Group ◽  
Clinical Samples ◽  
Binding Motif ◽  
Ki 67 ◽  
Tissue Samples

Abstract Background Intensive evidence has highlighted the effect of aberrant alternative splicing (AS) events on cancer progression when triggered by dysregulation of the SR protein family. Nonetheless, the underlying mechanism in breast cancer (BRCA) remains elusive. Here we sought to explore the molecular function of SRSF1 and identify the key AS events regulated by SRSF1 in BRCA. Methods We conducted a comprehensive analysis of the expression and clinical correlation of SRSF1 in BRCA based on the TCGA dataset, Metabric database and clinical tissue samples. Functional analysis of SRSF1 in BRCA was conducted in vitro and in vivo. SRSF1-mediated AS events and their binding motifs were identified by RNA-seq, RNA immunoprecipitation-PCR (RIP-PCR) and in vivo crosslinking followed by immunoprecipitation (CLIP), which was further validated by the minigene reporter assay. PTPMT1 exon 3 (E3) AS was identified to partially mediate the oncogenic role of SRSF1 by the P-AKT/C-MYC axis. Finally, the expression and clinical significance of these AS events were validated in clinical samples and using the TCGA database. Results SRSF1 expression was consistently upregulated in BRCA samples, positively associated with tumor grade and the Ki-67 index, and correlated with poor prognosis in a hormone receptor-positive (HR+) cohort, which facilitated proliferation, cell migration and inhibited apoptosis in vitro and in vivo. We identified SRSF1-mediated AS events and discovered the SRSF1 binding motif in the regulation of splice switching of PTPMT1. Furthermore, PTPMT1 splice switching was regulated by SRSF1 by binding directly to its motif in E3 which partially mediated the oncogenic role of SRSF1 by the AKT/C-MYC axis. Additionally, PTPMT1 splice switching was validated in tissue samples of BRCA patients and using the TCGA database. The high-risk group, identified by AS of PTPMT1 and expression of SRSF1, possessed poorer prognosis in the stage I/II TCGA BRCA cohort. Conclusions SRSF1 exerts oncogenic roles in BRCA partially by regulating the AS of PTPMT1, which could be a therapeutic target candidate in BRCA and a prognostic factor in HR+ BRCA patient.

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