scholarly journals Afadin couples RAS GTPases to the polarity rheostat Scribble

2021 ◽  
Author(s):  
Marilyn Goudreault ◽  
Valérie Gagné ◽  
Chang Hwa Jo ◽  
Swati Singh ◽  
Ryan Killoran ◽  
...  
Keyword(s):  
Growth Factor ◽  
Pdz Domain ◽  
Dependent Manner ◽  
Fha Domain ◽  
Cell Contacts ◽  
Ras Gtpases ◽  
Pi3k Activation ◽  
Interaction Map ◽  
Ras Signalling ◽  
Broad Specificity

Abstract AFDN/Afadin is required for establishment and maintenance of cell-cell contacts and is a unique effector of RAS GTPases. The biological consequences of RAS signalling to AFDN are unknown. Here, we use proximity-based proteomics to generate an interaction map for the long and short isoforms of AFDN, identifying the polarity protein SCRIB/Scribble as the top hit. We reveal that the first PDZ domain of SCRIB and the AFDN FHA domain mediate a direct but non-canonical interaction between these important adhesion and polarity proteins. Further, the dual RA domains of AFDN have broad specificity for RAS and RAP GTPases, and KRAS co-localizes with and promotes AFDN-SCRIB complex formation. Knockout of AFDN or SCRIB in MCF7 epithelial cells disrupts MAPK and PI3K activation and inhibits cell motility in a growth factor-dependent manner. These data have important implications for understanding why cells with activated RAS have reduced cell contacts and polarity defects, and finally begin to characterize AFDN as a RAS effector.

scholarly journals Ligand-induced recruitment of Na+/H+-exchanger regulatory factor to the PDGF (platelet-derived growth factor) receptor regulates actin cytoskeleton reorganization by PDGF

2003 ◽  
Vol 376 (2) ◽  
pp. 505-510 ◽  
Author(s):  
Jean-Baptiste DEMOULIN ◽  
Jeong Kon SEO ◽  
Simon EKMAN ◽  
Eva GRAPENGIESSER ◽  
Ulf HELLMAN ◽  
...  
Keyword(s):  
Growth Factor ◽  
Ph Regulation ◽  
Pdz Domain ◽  
Growth Factor Receptor ◽  
Platelet Derived Growth Factor ◽  
Dependent Manner ◽  
Pdgf Receptor ◽  
Regulatory Factor ◽  
C Terminus ◽  
Cytoskeleton Reorganization

Proteins interacting with the human PDGF (platelet-derived growth factor) β-receptor were isolated using immobilized peptides derived from the receptor C-terminus as a bait. We identified two PDZ domain proteins, namely NHERF (Na+/H+ exchanger regulatory factor, also called EBP50) and NHERF2 (E3KARP, SIP-1, TKA-1), which have been shown previously to associate with the murine PDGF receptor [Maudsley, Zamah, Rahman, Blitzer, Luttrell, Lefkowitz and Hall (2000) Mol. Cell. Biol. 20, 8352–8363]. In porcine aortic endothelial cells and in fibroblasts, NHERF recruitment was induced by PDGF treatment, but the receptor kinase activity was not required for the formation of the complex, suggesting that NHERF was not recruited in a phosphotyrosine-dependent manner. Instead, the interaction was abolished by mutation of the consensus C-terminal PDZ-interacting domain of the receptor (Leu-1106 to Ala), or truncation of the last 75 amino acid residues of the receptor. Disruption of NHERF binding to the receptor enhanced actin filament reorganization, but did not affect PDGF-induced mitogenicity and chemotaxis. Although NHERF was initially characterized as a factor required for intracellular pH regulation by β2-adrenergic receptors, we observed that it was not involved in pH regulation by PDGF. Collectively, these results suggest that the ligand-induced association of NHERF PDZ domain with the PDGF receptor tyrosine kinase controls the extent of cytoskeleton reorganization in response to PDGF.

scholarly journals Silibinin Regulates Tumor Progression and Tumorsphere Formation by Suppressing PD-L1 Expression in Non-Small Cell Lung Cancer (NSCLC) Cells

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1632
Author(s):  
Alexis Rugamba ◽  
Dong Young Kang ◽  
Nipin Sp ◽  
Eun Seong Jo ◽  
Jin-Moo Lee ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Growth Factor ◽  
Small Cell Lung Cancer ◽  
Anticancer Activity ◽  
Cell Lung Cancer ◽  
Small Cell ◽  
Migration And Invasion ◽  
Dependent Manner ◽  
Molecular Signaling ◽  
Small Cell Lung

Recently, natural compounds have been used globally for cancer treatment studies. Silibinin is a natural compound extracted from Silybum marianum (milk thistle), which has been suggested as an anticancer drug through various studies. Studies on its activity in various cancers are undergoing. This study demonstrated the molecular signaling behind the anticancer activity of silibinin in non-small cell lung cancer (NSCLC). Quantitative real-time polymerase chain reaction and Western blotting analysis were performed for molecular signaling analysis. Wound healing assay, invasion assay, and in vitro angiogenesis were performed for the anticancer activity of silibinin. The results indicated that silibinin inhibited A549, H292, and H460 cell proliferation in a concentration-dependent manner, as confirmed by the induction of G0/G1 cell cycle arrest and apoptosis and the inhibition of tumor angiogenesis, migration, and invasion. This study also assessed the role of silibinin in suppressing tumorsphere formation using the tumorsphere formation assay. By binding to the epidermal growth factor receptor (EGFR), silibinin downregulated phosphorylated EGFR expression, which then inhibited its downstream targets, the JAK2/STAT5 and PI3K/AKT pathways, and thereby reduced matrix metalloproteinase, PD-L1, and vascular endothelial growth factor expression. Binding analysis demonstrated that STAT5 binds to the PD-L1 promoter region in the nucleus and silibinin inhibited the STAT5/PD-L1 complex. Altogether, silibinin could be considered as a candidate for tumor immunotherapy and cancer stem cell-targeted therapy.

Intracisternal administration of transforming growth factor-β evokes fever through the induction of cyclooxygenase-2 in brain endothelial cells

2008 ◽  
Vol 294 (1) ◽  
pp. R266-R275 ◽  
Author(s):  
Shigenobu Matsumura ◽  
Tetsuro Shibakusa ◽  
Teppei Fujikawa ◽  
Hiroyuki Yamada ◽  
Kiyoshi Matsumura ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Growth Factor ◽  
Proinflammatory Cytokines ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Cyclooxygenase 2 ◽  
Dependent Manner ◽  
Cox 2 ◽  
Β Receptor

Transforming growth factor-β (TGF-β), a pleiotropic cytokine, regulates cell proliferation, differentiation, and apoptosis, and plays a key role in development and tissue homeostasis. TGF-β functions as an anti-inflammatory cytokine because it suppresses microglia and B-lymphocyte functions, as well as the production of proinflammatory cytokines. However, we previously demonstrated that the intracisternal administration of TGF-β induces fever like that produced by proinflammatory cytokines. In this study, we investigated the mechanism of TGF-β-induced fever. The intracisternal administration of TGF-β increased body temperature in a dose-dependent manner. Pretreatment with cyclooxygenase-2 (COX-2)-selective inhibitor significantly suppressed TGF-β-induced fever. COX-2 is known as one of the rate-limiting enzymes of the PGE2 synthesis pathway, suggesting that fever induced by TGF-β is COX-2 and PGE2 dependent. TGF-β increased PGE2 levels in cerebrospinal fluid and increased the expression of COX-2 in the brain. Double immunostaining of COX-2 and von Willebrand factor (vWF, an endothelial cell marker) revealed that COX-2-expressing cells were mainly endothelial cells. Although not all COX-2-immunoreactive cells express TGF-β receptor, some COX-2-immunoreactive cells express activin receptor-like kinase-1 (ALK-1, an endothelial cell-specific TGF-β receptor), suggesting that TGF-β directly or indirectly acts on endothelial cells to induce COX-2 expression. These findings suggest a novel function of TGF-β as a proinflammatory cytokine in the central nervous system.

scholarly journals Transactivation of Platelet-Derived Growth Factor Receptor α by the GTPase-Deficient Activated Mutant of Gα12

2006 ◽  
Vol 26 (1) ◽  
pp. 50-62 ◽  
Author(s):  
Rashmi N. Kumar ◽  
Ji Hee Ha ◽  
Rangasudhagar Radhakrishnan ◽  
Danny N. Dhanasekaran
Keyword(s):  
Growth Factor ◽  
Cell Growth ◽  
Signaling Pathway ◽  
Growth Factor Receptor ◽  
Platelet Derived Growth Factor ◽  
Dominant Negative Mutant ◽  
Dependent Manner ◽  
3T3 Cells ◽  
Nih 3T3 ◽  
Nih 3T3 Cells

ABSTRACT The GTPase-deficient, activated mutant of Gα12 (Gα12Q229L, or Gα12QL) induces neoplastic growth and oncogenic transformation of NIH 3T3 cells. Using microarray analysis, we have previously identified a role for platelet-derived growth factor receptor α (PDGFRα) in Gα12-mediated cell growth (R. N. Kumar et al., Cell Biochem. Biophys. 41:63-73, 2004). In the present study, we report that Gα12QL stimulates the functional expression of PDGFRα and demonstrate that the expression of PDGFRα by Gα12QL is dependent on the small GTPase Rho. Our results indicate that it is cell type independent as the transient expression of Gα12QL or the activation of Gα12-coupled receptors stimulates the expression of PDGFRα in NIH 3T3 as well as in human astrocytoma 1321N1 cells. Furthermore, we demonstrate the presence of an autocrine loop involving PDGF-A and PDGFRα in Gα12QL-transformed cells. Analysis of the functional consequences of the Gα12-PDGFRα signaling axis indicates that Gα12 stimulates the phosphatidylinositol 3-kinase (PI3K)-AKT signaling pathway through PDGFR. In addition, we show that Gα12QL stimulates the phosphorylation of forkhead transcription factor FKHRL1 via AKT in a PDGFRα- and PI3K-dependent manner. Since AKT promotes cell growth by blocking the transcription of antiproliferative genes through the inhibitory phosphorylation of forkhead transcription factors, our results describe for the first time a PDGFRα-dependent signaling pathway involving PI3K-AKT-FKHRL1, regulated by Gα12QL in promoting cell growth. Consistent with this view, we demonstrate that the expression of a dominant negative mutant of PDGFRα attenuated Gα12-mediated neoplastic transformation of NIH 3T3 cells.

scholarly journals Suppression of a Novel Hematopoietic Mediator in Children with Severe Malarial Anemia

2009 ◽  
Vol 77 (9) ◽  
pp. 3864-3871 ◽  
Author(s):  
Christopher C. Keller ◽  
Collins Ouma ◽  
Yamo Ouma ◽  
Gordon A. Awandare ◽  
Gregory C. Davenport ◽  
...  
Keyword(s):  
Growth Factor ◽  
Mononuclear Cells ◽  
Dependent Manner ◽  
Peripheral Blood Mononuclear ◽  
Severe Malarial Anemia ◽  
Lectin Domain ◽  
Stem Cell Growth Factor ◽  
Reticulocyte Production ◽  
Pediatric Morbidity ◽  
Malarial Anemia

ABSTRACT In areas of holoendemic Plasmodium falciparum transmission, severe malarial anemia (SMA) is a leading cause of pediatric morbidity and mortality. Although many soluble mediators regulate erythropoiesis, it is unclear how these factors contribute to development of SMA. Investigation of novel genes dysregulated in response to malarial pigment (hemozoin [PfHz]) revealed that stem cell growth factor (SCGF; also called C-type lectin domain family member 11A [CLEC11A]), a hematopoietic growth factor important for development of erythroid and myeloid progenitors, was one of the most differentially expressed genes. Additional experiments with cultured peripheral blood mononuclear cells (PBMCs) demonstrated that PfHz decreased SCGF/CLEC11A transcriptional expression in a time-dependent manner. Circulating SCGF levels were then determined for Kenyan children (n = 90; aged 3 to 36 months) presenting at a rural hospital with various severities of malarial anemia. SCGF levels in circulation (P = 0.001) and in cultured PBMCs (P = 0.004) were suppressed in children with SMA. Circulating SCGF also correlated positively with hemoglobin levels (r = 0.241; P = 0.022) and the reticulocyte production index (RPI) (r = 0.280; P = 0.029). In addition, SCGF was decreased in children with reduced erythropoiesis (RPI of <2) (P < 0.001) and in children with elevated levels of naturally acquired monocytic PfHz (P = 0.019). Thus, phagocytosis of PfHz promotes a decrease in SCGF gene products, which may contribute to reduced erythropoiesis in children with SMA.

scholarly journals Density-dependent nerve growth factor regulation of Gs-alpha RNA in pheochromocytoma 12 cells.

1990 ◽  
Vol 10 (6) ◽  
pp. 3277-3279 ◽  
Author(s):  
G Tjaden ◽  
A Aguanno ◽  
R Kumar ◽  
D Benincasa ◽  
R M Gubits ◽  
...  
Keyword(s):  
Nerve Growth Factor ◽  
Growth Factor ◽  
G Protein ◽  
Alpha Subunit ◽  
Low Density ◽  
Dependent Manner ◽  
Nerve Growth ◽  
Density Dependent ◽  
Stimulatory G Protein ◽  
Gs Alpha

Nerve growth factor (NGF) affects levels of the alpha subunit of the stimulatory G protein (Gs-alpha) in pheochromocytoma 12 cells in a bidirectional, density-dependent manner. Cells grown at high density responded to NGF treatment with increased levels of Gs-alpha mRNA and protein. Conversely, in cells grown in low-density cultures, levels of this mRNA were lowered by NGF treatment.

scholarly journals Region-Specific Microtubule Transport in Motile Cells

2000 ◽  
Vol 151 (5) ◽  
pp. 1003-1012 ◽  
Author(s):  
Anne-Marie C. Yvon ◽  
Patricia Wadsworth
Keyword(s):  
Growth Factor ◽  
Cell Motility ◽  
Cell Body ◽  
Dependent Manner ◽  
Retrograde Flow ◽  
Cell Locomotion ◽  
Quantitative Measurements ◽  
Motile Cells ◽  
Microtubule Transport ◽  
Hepatocyte Growth

Photoactivation and photobleaching of fluorescence were used to determine the mechanism by which microtubules (MTs) are remodeled in PtK2 cells during fibroblast-like motility in response to hepatocyte growth factor (HGF). The data show that MTs are transported during cell motility in an actomyosin-dependent manner, and that the direction of transport depends on the dominant force in the region examined. MTs in the leading lamella move rearward relative to the substrate, as has been reported in newt cells (Waterman-Storer, C.M., and E.D. Salmon. 1997. J. Cell Biol. 139:417–434), whereas MTs in the cell body and in the retraction tail move forward, in the direction of cell locomotion. In the transition zone between the peripheral lamella and the cell body, a subset of MTs remains stationary with respect to the substrate, whereas neighboring MTs are transported either forward, with the cell body, or rearward, with actomyosin retrograde flow. In addition to transport, the photoactivated region frequently broadens, indicating that individual marked MTs are moved either at different rates or in different directions. Mark broadening is also observed in nonmotile cells, indicating that this aspect of transport is independent of cell locomotion. Quantitative measurements of the dissipation of photoactivated fluorescence show that, compared with MTs in control nonmotile cells, MT turnover is increased twofold in the lamella of HGF-treated cells but unchanged in the retraction tail, demonstrating that microtubule turnover is regionally regulated.

scholarly journals Apurinic/apyrimidinic endonuclease 1 regulates angiogenesis in a transforming growth factor β‐dependent manner in human osteosarcoma

2015 ◽  
Vol 106 (10) ◽  
pp. 1394-1401 ◽  
Author(s):  
Xuan Jiang ◽  
Jinlu Shan ◽  
Nan Dai ◽  
Zhaoyang Zhong ◽  
Yi Qing ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Dependent Manner ◽  
Human Osteosarcoma

Safflower injection inhibits pulmonary arterial remodeling in a monocrotaline-induced pulmonary arterial hypertension rat model

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Aifeng Chen ◽  
Shibiao Ding ◽  
Liangliang Kong ◽  
Jianpu Xu ◽  
Fei He ◽  
...  
Keyword(s):  
Growth Factor ◽  
Pulmonary Arterial Hypertension ◽  
Pulmonary Artery ◽  
Arterial Hypertension ◽  
Cardiac Muscle ◽  
Rat Model ◽  
Dependent Manner ◽  
Arterial Remodeling ◽  
Pulmonary Arterial ◽  
Dose Dependent

AbstractPulmonary arterial hypertension (PAH) is a group of diseases with an increase of pulmonary artery pressure (PAP) and pulmonary vascular resistance. Here, the effects of safflower injection, a preparation of Chinese herbs, was investigated in a monocrotaline (MCT)-induced PAH rat model. PAP, carotid artery pressure (CAP), and the right ventricular hypertrophy index (RVHI) increased in the PAH group, while safflower injection was able to inhibit this increase to similar levels as observed in the normal group. The arteriole wall of the lungs and cardiac muscle were thickened and edema was observed in the PAH group, while these pathologies were improved in the herb-treated group in a dose-dependent manner. MCT treatment induced proliferation of pulmonary artery smooth muscle cells (PASMCs), which was inhibited by safflower injection in a dose-dependent manner. Our experimental results demonstrated that safflower injection can regulate pulmonary arterial remodeling through affecting the expression of connective tissue growth factor, transforming growth factor-β, integrin, collagen or fibronectin, which subsequently affected the thicknesses of the arteriole walls of the lungs and cardiac muscle, and thereby benefits the control of PAH. This means safflower injection improved the abnormalities in PAP, CAP and RVHI, and pulmonary arterial remodeling through regulation of remodeling factors.

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