P-Selectin-β2-Integrin Cross-Talk: A Molecular Mechanism For Polymorphonuclear Leukocyte Recruitment At The Site Of Vascular Damage

IntroductionPlatelets activated at the site of vascular damage play a pivotal role in polymorphonuclear (PMN) leukocyte accumulation in a growing thrombus2,3 and may substitute endothelial cells in the recruitment and migration of leukocytes through damaged vessel wall.4 Leukocytes, accumulated in a platelet thrombus, can contribute to further platelet activation5 and to increased fibrin deposition.6 These events, on the one hand, may contribute to the maintenance of vascular and tissue integrity. They may, however, play a pathogenic role in inflammatory and thrombotic disease, providing some biological plausibility to the epidemiological evidence of significant association between leukocyte count and the incidence of coronary heart disease.7,8 We shall focus our attention on the molecular mechanisms involved in the recruitment of PMN leukocytes on activated platelets as it occurs at the site of vascular damage, with particular attention to P-selectin- β2-integrin cross-talk.

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Glia Maturation Factor-Gamma Mediates Human Monocytes Migration Through Regulating β1/β2-Integrin Recycling

Blood ◽

10.1182/blood.v122.21.1027.1027 ◽

2013 ◽

Vol 122 (21) ◽

pp. 1027-1027

Author(s):

Wulin Aerbajinai ◽

Lunhua Liu ◽

Chutima Kumkhaek ◽

Kyung Chin ◽

Griffin P. Rodgers

Keyword(s):

Plasma Membrane ◽

Molecular Mechanisms ◽

Conflicts Of Interest ◽

Inflammatory Cells ◽

Effective Control ◽

Glia Maturation Factor ◽

Β2 Integrin ◽

Maturation Factor ◽

Early Endosomes ◽

And Migration

Abstract Recruitment of monocytes is essential for effective control and clearance of invading pathogens by migrating to the sites of infection, but recruited monocytes also contribute to the pathogenesis of chronic inflammatory and degenerative diseases, such as rheumatoid arthritis, multiple sclerosis, atherosclerosis and cancer. Thus, understanding the mechanisms controlling monocytes migration within different environments is of paramount importance. Although it is clear that adhesion signaling via integrin receptors and the surrounding ECM play a significant role in regulating migration of monocytes to site of inflammation, the underlying cellular and molecular mechanisms responsible for these process is still not fully characterized. Defining the molecular circuits through which integrins regulate monocytes motility is therefore important for gaining a better understanding of monocytes function. Glia maturation factor gamma (GMFG), a novel ADF/cofilin superfamily protein that is predominantly expressed in inflammatory cells, has been implicated in regulating actin reorganization. We have previously demonstrated that GMFG plays a role in regulating neutrophil chemotaxis and migration. We now examine whether GMFG has similar effects on monocytes and the cellular mechanism for these effects by using small-interfering RNA to knockdown GMFG in human primary monocytes. Knockdown of endogenous GMFG results in significantly reduced (220.6 ± 9.4 to 89.0 ± 3.2, p<0.003) chemotactic migration toward SDF-1 and enhanced adhesion on fibronectin, VCAM-1 and ICAM-1 compared with control siRNA transfected cells. Flow cytometry analysis shows that knockdown of GMFG enhances the expression of β1-, β2−integrin on the cell surface compared with control cells. Confocal microscopy analysis exhibited that GMFG is colocalized with internalized β1-, β2-integrin in early endosomes in primary monocytes. However, an internalization assay shows that β1- and β2-integrin were internalized with similar kinetics during the initial uptake time points both in control or GMFG knockdown primary monocytes. These data demonstrated that internalization of β1- and β2-integrin was not impaired in GMFG knockdown cells, suggesting that GMFG regulates β integrins recycling. Antibody-based recycling assays showed that GMFG knockdown cells resulted in enhanced plasma membrane exocytosis of β1- and β2-integrin compared with control cells. Western blot analysis revealed that SDF-1 stimulated the phosphoryalation of FAK (Tyr397) is moderately (∼ 40%) increased in GMFG knockdown monocytes compared with control cells. These results suggest that impaired monocytes migrated toward SDF-1 stimulation in GMFG depletion monocytes is due to enhanced adhesion, which is caused by accelerated recycling of β1- and β2-integrin to the surface. Taken together, these results indicate that GMFG is required to maintain the proper expression levels of β1- and β2-integrin on the plasma membrane and is fundamental for integrin-mediated monocytes motility. Disclosures: No relevant conflicts of interest to declare.

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Wnt/beta-catenin and PI3K/Akt/mTOR Signaling Pathways in Glioblastoma: Two Main Targets for Drug Design: A Review

Current Pharmaceutical Design ◽

10.2174/1381612826666200131100630 ◽

2020 ◽

Vol 26 (15) ◽

pp. 1729-1741 ◽

Cited By ~ 4

Author(s):

Seyed H. Shahcheraghi ◽

Venant Tchokonte-Nana ◽

Marzieh Lotfi ◽

Malihe Lotfi ◽

Ahmad Ghorbani ◽

...

Keyword(s):

Signaling Pathways ◽

Molecular Mechanisms ◽

Cellular Proliferation ◽

Chemotherapy Resistance ◽

Wnt Signaling Pathway ◽

Therapeutic Interventions ◽

Beta Catenin ◽

Clinical Prognosis ◽

Invasion And Migration ◽

And Migration

: Glioblastoma (GBM) is the most common and malignant astrocytic glioma, accounting for about 90% of all brain tumors with poor prognosis. Despite recent advances in understanding molecular mechanisms of oncogenesis and the improved neuroimaging technologies, surgery, and adjuvant treatments, the clinical prognosis of patients with GBM remains persistently unfavorable. The signaling pathways and the regulation of growth factors of glioblastoma cells are very abnormal. The various signaling pathways have been suggested to be involved in cellular proliferation, invasion, and glioma metastasis. The Wnt signaling pathway with its pleiotropic functions in neurogenesis and stem cell proliferation is implicated in various human cancers, including glioma. In addition, the PI3K/Akt/mTOR pathway is closely related to growth, metabolism, survival, angiogenesis, autophagy, and chemotherapy resistance of GBM. Understanding the mechanisms of GBM’s invasion, represented by invasion and migration, is an important tool in designing effective therapeutic interventions. This review will investigate two main signaling pathways in GBM: PI3K/Akt/mTOR and Wnt/beta-catenin signaling pathways.

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Effects and Mechanisms of Anlotinib and Dihydroartemisinin Combination Therapy in Ameliorating Malignant Biological Behavior of Gastric Cancer Cells

Current Pharmaceutical Biotechnology ◽

10.2174/1389201021666200623132803 ◽

2020 ◽

Vol 21 ◽

Author(s):

Qiong Luo ◽

Suyun Zhang ◽

Donghuan Zhang ◽

Rui Feng ◽

Nan Li ◽

...

Keyword(s):

Gastric Cancer ◽

Cancer Cells ◽

Molecular Mechanisms ◽

Chorioallantoic Membrane ◽

Cell Counting ◽

Biological Behavior ◽

Gastric Cancer Cells ◽

Invasion And Migration ◽

Apoptosis Related Protein ◽

And Migration

Background: Gastric cancer(GC) is currently one of the major malignancies that threatens human lives and health. Anlotinib is a novel small-molecule that inhibits angiogenesis to exert anti-tumor effects. However, the function in gastric cancer is incompletely understood. Objective: The aim of the present study was to investigate the anti-tumor effects and molecular mechanisms of anlotinib combined with dihydroartemisinin (DHA) in SGC7901 gastric cancer cells. Method: Different concentrations of anlotinib and DHA were used to treat SGC7901 gastric cancer cells, after which cell proliferation was measured. Drug interactions of anlotinib and DHA were analyzed by the Chou-Talalay method with CompuSyn software. proliferation, apoptosis, invasion, migration, and angiogenesis were measured using the cell counting kit-8 (CCK8) assay, flow cytometry, Transwell invasion assays, scratch assays, and chicken chorioallantoic membrane (CAM) assays. proliferation-associated protein (Ki67), apoptosis-related protein (Bcl-2), and vascular endothelial growth factor A (VEGF-A) were quantified by Western bloting. Results: The combination of 2.5 μmol/L of anlotinib and 5 of μmol/L DHA was highly synergistic in inhibiting cell growth, significantly increased the apoptosis rate and suppressed obviously the invasion and migration capability and angiogenesis of gastric cancer cells. In addition, the expression levels of Ki67, Bcl-2, and VEGF-A, as well as angiogenesis, were significantly decreased in the Combination of drugs compared with in control and either drug alone. Conclusion: The combination of anlotinib and DHA showed synergistic antitumor activity, suggesting their potential in treating patients with gastric cancer.

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Circular RNA mmu_circ_0005019 inhibits fibrosis of cardiac fibroblasts and reverses electrical remodeling of cardiomyocytes

BMC Cardiovascular Disorders ◽

10.1186/s12872-021-02128-w ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Na Wu ◽

Chengying Li ◽

Bin Xu ◽

Ying Xiang ◽

Xiaoyue Jia ◽

...

Keyword(s):

Molecular Mechanisms ◽

Cardiac Fibroblasts ◽

Circular Rna ◽

Protective Role ◽

Luciferase Reporter ◽

Loss Of Function ◽

Candidate Target ◽

Paired Control ◽

Reporter Assays ◽

And Migration

Abstract Background Circular RNA (circRNA) have been reported to play important roles in cardiovascular diseases including myocardial infarction and heart failure. However, the role of circRNA in atrial fibrillation (AF) has rarely been investigated. We recently found a circRNA hsa_circ_0099734 was significantly differentially expressed in the AF patients atrial tissues compared to paired control. We aim to investigate the functional role and molecular mechanisms of mmu_circ_0005019 which is the homologous circRNA in mice of hsa_circ_0099734 in AF. Methods In order to investigate the effect of mmu_circ_0005019 on the proliferation, migration, differentiation into myofibroblasts and expression of collagen of cardiac fibroblasts, and the effect of mmu_circ_0005019 on the apoptosis and expression of Ito, INA and SK3 of cardiomyocytes, gain- and loss-of-function of cell models were established in mice cardiac fibroblasts and HL-1 atrial myocytes. Dual-luciferase reporter assays and RIP were performed to verify the binding effects between mmu_circ_0005019 and its target microRNA (miRNA). Results In cardiac fibroblasts, mmu_circ_0005019 showed inhibitory effects on cell proliferation and migration. In cardiomyocytes, overexpression of mmu_circ_0005019 promoted Kcnd1, Scn5a and Kcnn3 expression. Knockdown of mmu_circ_0005019 inhibited the expression of Kcnd1, Kcnd3, Scn5a and Kcnn3. Mechanistically, mmu_circ_0005019 exerted biological functions by acting as a miR-499-5p sponge to regulate the expression of its target gene Kcnn3. Conclusions Our findings highlight mmu_circ_0005019 played a protective role in AF development and might serve as an attractive candidate target for AF treatment.

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Cyr61 promotes Schwann cell proliferation and migration via αvβ3 integrin

BMC Molecular and Cell Biology ◽

10.1186/s12860-021-00360-y ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Zhenghui Cheng ◽

Yawen Zhang ◽

Yinchao Tian ◽

Yuhan Chen ◽

Fei Ding ◽

...

Keyword(s):

Nerve Injury ◽

Peripheral Nerves ◽

Molecular Mechanisms ◽

Αvβ3 Integrin ◽

Promoting Effect ◽

Ccn Family ◽

And Migration ◽

Proliferation And Migration

Abstract Background Schwann cells (SCs) play a crucial role in the repair of peripheral nerves. This is due to their ability to proliferate, migrate, and provide trophic support to axon regrowth. During peripheral nerve injury, SCs de-differentiate and reprogram to gain the ability to repair nerves. Cysteine-rich 61 (Cyr61/CCN1) is a member of the CCN family of matrix cell proteins and have been reported to be abundant in the secretome of repair mediating SCs. In this study we investigate the function of Cyr61 in SCs. Results We observed Cyr61 was expressed both in vivo and in vitro. The promoting effect of Cyr61 on SC proliferation and migration was through autocrine and paracrine mechanisms. SCs expressed αvβ3 integrin and the effect of Cyr61 on SC proliferation and migration could be blocked via αvβ3 integrin. Cyr61 could influence c-Jun protein expression in cultured SCs. Conclusions In this study, we found that Cyr61 promotes SC proliferation and migration via αvβ3 integrin and regulates c-Jun expression. Our study contributes to the understanding of cellular and molecular mechanisms underlying SC’s function during nerve injury, and thus, may facilitate the regeneration of peripheral nerves after injury.

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Regulation of Store-Operated Ca2+ Entry by SARAF

Cells ◽

10.3390/cells10081887 ◽

2021 ◽

Vol 10 (8) ◽

pp. 1887

Author(s):

Inbal Dagan ◽

Raz Palty

Keyword(s):

Molecular Mechanisms ◽

Feedback Mechanism ◽

Cellular Biology ◽

Excitable Cells ◽

Major Pathway ◽

Negative Feedback Mechanism ◽

Crac Channels ◽

Dependent Inactivation ◽

Crac Channel ◽

The One

Calcium (Ca2+) signaling plays a dichotomous role in cellular biology, controlling cell survival and proliferation on the one hand and cellular toxicity and cell death on the other. Store-operated Ca2+ entry (SOCE) by CRAC channels represents a major pathway for Ca2+ entry in non-excitable cells. The CRAC channel has two key components, the endoplasmic reticulum Ca2+ sensor stromal interaction molecule (STIM) and the plasma-membrane Ca2+ channel Orai. Physical coupling between STIM and Orai opens the CRAC channel and the resulting Ca2+ flux is regulated by a negative feedback mechanism of slow Ca2+ dependent inactivation (SCDI). The identification of the SOCE-associated regulatory factor (SARAF) and investigations of its role in SCDI have led to new functional and molecular insights into how SOCE is controlled. In this review, we provide an overview of the functional and molecular mechanisms underlying SCDI and discuss how the interaction between SARAF, STIM1, and Orai1 shapes Ca2+ signaling in cells.

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Knockdown CYP2S1 inhibits lung cancer cells proliferation and migration

Cancer Biomarkers ◽

10.3233/cbm-210189 ◽

2021 ◽

pp. 1-9

Author(s):

Huan Guo ◽

Baozhen Zeng ◽

Liqiong Wang ◽

Chunlei Ge ◽

Xianglin Zuo ◽

...

Keyword(s):

Lung Cancer ◽

Cell Proliferation ◽

Cell Growth ◽

Cancer Cells ◽

Molecular Mechanisms ◽

Lung Cancer Cells ◽

Invasion And Migration ◽

And Migration

BACKGROUND: The incidence of lung cancer in Yunnan area ranks firstly in the world and underlying molecular mechanisms of lung cancer in Yunnan region are still unclear. We screened a novel potential oncogene CYP2S1 used mRNA microassay and bioinformation database. The function of CYP2S1 in lung cancer has not been reported. OBJECTIVE: To investigate the functions of CYP2S1 in lung cancer. METHODS: Immunohistochemistry and Real-time PCR were used to verify the expression of CYP2S1. Colony formation and Transwell assays were used to determine cell proliferation, invasion and migration. Xenograft assays were used to detected cell growth in vivo. RESULTS: CYP2S1 is significantly up-regulated in lung cancer tissues and cells. Knockdown CYP2S1 in lung cancer cells resulted in decrease cell proliferation, invasion and migration in vitro. Animal experiments showed downregulation of CYP2S1 inhibited lung cancer cell growth in vivo. GSEA analysis suggested that CYP2S1 played functions by regulating E2F targets and G2M checkpoint pathway which involved in cell cycle. Kaplan-Meier analysis indicated that patients with high CYP2S1 had markedly shorter event overall survival (OS) time. CONCLUSIONS: Our data demonstrate that CYP2S1 exerts tumor suppressor function in lung cancer. The high expression of CYP2S1 is an unfavorable prognostic marker for patient survival.

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Diabetes and Thrombosis: A Central Role for Vascular Oxidative Stress

Antioxidants ◽

10.3390/antiox10050706 ◽

2021 ◽

Vol 10 (5) ◽

pp. 706

Author(s):

Aishwarya R. Vaidya ◽

Nina Wolska ◽

Dina Vara ◽

Reiner K. Mailer ◽

Katrin Schröder ◽

...

Keyword(s):

Diabetes Mellitus ◽

Molecular Mechanisms ◽

Vascular System ◽

Cell Damage ◽

National Health System ◽

Vascular Damage ◽

Circulating Cells ◽

Environmental Causes ◽

Vascular Oxidative Stress

Diabetes mellitus is the fifth most common cause of death worldwide. Due to its chronic nature, diabetes is a debilitating disease for the patient and a relevant cost for the national health system. Type 2 diabetes mellitus is the most common form of diabetes mellitus (90% of cases) and is characteristically multifactorial, with both genetic and environmental causes. Diabetes patients display a significant increase in the risk of developing cardiovascular disease compared to the rest of the population. This is associated with increased blood clotting, which results in circulatory complications and vascular damage. Platelets are circulating cells within the vascular system that contribute to hemostasis. Their increased tendency to activate and form thrombi has been observed in diabetes mellitus patients (i.e., platelet hyperactivity). The oxidative damage of platelets and the function of pro-oxidant enzymes such as the NADPH oxidases appear central to diabetes-dependent platelet hyperactivity. In addition to platelet hyperactivity, endothelial cell damage and alterations of the coagulation response also participate in the vascular damage associated with diabetes. Here, we present an updated interpretation of the molecular mechanisms underlying vascular damage in diabetes, including current therapeutic options for its control.

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Structural basis for activation of trimeric Gi proteins by multiple growth factor receptors via GIV/Girdin

Molecular Biology of the Cell ◽

10.1091/mbc.e14-05-0978 ◽

2014 ◽

Vol 25 (22) ◽

pp. 3654-3671 ◽

Cited By ~ 40

Author(s):

Changsheng Lin ◽

Jason Ear ◽

Krishna Midde ◽

Inmaculada Lopez-Sanchez ◽

Nicolas Aznar ◽

...

Keyword(s):

Growth Factor ◽

G Proteins ◽

Protein Interaction ◽

Cross Talk ◽

Tyrosine Kinases ◽

Molecular Mechanisms ◽

Growth Factor Receptors ◽

Structural Basis ◽

Nucleotide Exchange ◽

Protein Protein Interaction

A long-standing issue in the field of signal transduction is to understand the cross-talk between receptor tyrosine kinases (RTKs) and heterotrimeric G proteins, two major and distinct signaling hubs that control eukaryotic cell behavior. Although stimulation of many RTKs leads to activation of trimeric G proteins, the molecular mechanisms behind this phenomenon remain elusive. We discovered a unifying mechanism that allows GIV/Girdin, a bona fide metastasis-related protein and a guanine-nucleotide exchange factor (GEF) for Gαi, to serve as a direct platform for multiple RTKs to activate Gαi proteins. Using a combination of homology modeling, protein–protein interaction, and kinase assays, we demonstrate that a stretch of ∼110 amino acids within GIV C-terminus displays structural plasticity that allows folding into a SH2-like domain in the presence of phosphotyrosine ligands. Using protein–protein interaction assays, we demonstrated that both SH2 and GEF domains of GIV are required for the formation of a ligand-activated ternary complex between GIV, Gαi, and growth factor receptors and for activation of Gαi after growth factor stimulation. Expression of a SH2-deficient GIV mutant (Arg 1745→Leu) that cannot bind RTKs impaired all previously demonstrated functions of GIV—Akt enhancement, actin remodeling, and cell migration. The mechanistic and structural insights gained here shed light on the long-standing questions surrounding RTK/G protein cross-talk, set a novel paradigm, and characterize a unique pharmacological target for uncoupling GIV-dependent signaling downstream of multiple oncogenic RTKs.

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