1
|
Araya MK, Chen W, Ke Y, Zhou Y, Gorfe AA, Hancock JF, Liu J. Differential Lipid Binding Specificities of RAP1A and RAP1B are Encoded by the Amino Acid Sequence of the Membrane Anchors. J Am Chem Soc 2024; 146:19782-19791. [PMID: 39001846 DOI: 10.1021/jacs.4c02183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/15/2024]
Abstract
RAP1 proteins belong to the RAS family of small GTPases that operate as molecular switches by cycling between GDP-bound inactive and GTP-bound active states. The C-terminal anchors of RAP1 proteins are known to direct membrane localization, but how these anchors organize RAP1 on the plasma membrane (PM) has not been investigated. Using high-resolution imaging, we show that RAP1A and RAP1B form spatially segregated nanoclusters on the inner leaflet of the PM, with further lateral segregation between GDP-bound and GTP-bound proteins. The C-terminal polybasic anchors of RAP1A and RAP1B differ in their amino acid sequences and exhibit different lipid binding specificities, which can be modified by single-point mutations in the respective polybasic domains (PBD). Molecular dynamics simulations reveal that single PBD mutations substantially reduce the interactions of the membrane anchors with the PM lipid phosphatidylserine. In summary, we show that aggregate lipid binding specificity encoded within the C-terminal anchor determines PM association and nanoclustering of RAP1A and RAP1B. Taken together with previous observations on RAC1 and KRAS, the study reveals that the PBD sequences of small GTPase membrane anchors can encode distinct lipid binding specificities that govern PM interactions.
Collapse
Affiliation(s)
- Mussie K Araya
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, Texas 77030, United States
| | - Wei Chen
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, Texas 77030, United States
| | - Yuepeng Ke
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M University, Houston, Texas 77030, United States
- Department of Translational Medical Sciences, School of Medicine, Texas A&M University, Houston, Texas 77030, United States
| | - Yubin Zhou
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M University, Houston, Texas 77030, United States
- Department of Translational Medical Sciences, School of Medicine, Texas A&M University, Houston, Texas 77030, United States
| | - Alemayehu A Gorfe
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, Texas 77030, United States
- Graduate School of Biological Sciences, M. D. Anderson Cancer Center and University of Texas Health Science Center, Houston, Texas 77030, United States
| | - John F Hancock
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, Texas 77030, United States
- Graduate School of Biological Sciences, M. D. Anderson Cancer Center and University of Texas Health Science Center, Houston, Texas 77030, United States
| | - Junchen Liu
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, Texas 77030, United States
- Graduate School of Biological Sciences, M. D. Anderson Cancer Center and University of Texas Health Science Center, Houston, Texas 77030, United States
| |
Collapse
|
2
|
Kim YD, Park HG, Song S, Kim J, Lee BJ, Broadie K, Lee S. Presynaptic structural and functional plasticity are coupled by convergent Rap1 signaling. J Cell Biol 2024; 223:e202309095. [PMID: 38748250 PMCID: PMC11096849 DOI: 10.1083/jcb.202309095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 02/07/2024] [Accepted: 03/27/2024] [Indexed: 05/18/2024] Open
Abstract
Dynamic presynaptic actin remodeling drives structural and functional plasticity at synapses, but the underlying mechanisms remain largely unknown. Previous work has shown that actin regulation via Rac1 guanine exchange factor (GEF) Vav signaling restrains synaptic growth via bone morphogenetic protein (BMP)-induced receptor macropinocytosis and mediates synaptic potentiation via mobilization of reserve pool vesicles in presynaptic boutons. Here, we find that Gef26/PDZ-GEF and small GTPase Rap1 signaling couples the BMP-induced activation of Abelson kinase to this Vav-mediated macropinocytosis. Moreover, we find that adenylate cyclase Rutabaga (Rut) signaling via exchange protein activated by cAMP (Epac) drives the mobilization of reserve pool vesicles during post-tetanic potentiation (PTP). We discover that Rap1 couples activation of Rut-cAMP-Epac signaling to Vav-mediated synaptic potentiation. These findings indicate that Rap1 acts as an essential, convergent node for Abelson kinase and cAMP signaling to mediate BMP-induced structural plasticity and activity-induced functional plasticity via Vav-dependent regulation of the presynaptic actin cytoskeleton.
Collapse
Affiliation(s)
- Yeongjin David Kim
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, Korea
| | - Hyun Gwan Park
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, Korea
| | - Seunghwan Song
- Interdisciplinary Program in Neuroscience, Seoul National University, Seoul, Korea
| | - Joohyung Kim
- Department of Cell and Developmental Biology and Dental Research Institute, Seoul National University, Seoul, Korea
| | - Byoung Ju Lee
- Department of Cell and Developmental Biology and Dental Research Institute, Seoul National University, Seoul, Korea
| | - Kendal Broadie
- Departments of Cell and Developmental Biology, Pharmacology, and Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN, USA
| | - Seungbok Lee
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, Korea
- Interdisciplinary Program in Neuroscience, Seoul National University, Seoul, Korea
- Department of Cell and Developmental Biology and Dental Research Institute, Seoul National University, Seoul, Korea
| |
Collapse
|
3
|
Moon DO. Deciphering the Role of BCAR3 in Cancer Progression: Gene Regulation, Signal Transduction, and Therapeutic Implications. Cancers (Basel) 2024; 16:1674. [PMID: 38730626 PMCID: PMC11083344 DOI: 10.3390/cancers16091674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 04/24/2024] [Accepted: 04/24/2024] [Indexed: 05/13/2024] Open
Abstract
This review comprehensively explores the gene BCAR3, detailing its regulation at the gene, mRNA, and protein structure levels, and delineating its multifunctional roles in cellular signaling within cancer contexts. The discussion covers BCAR3's involvement in integrin signaling and its impact on cancer cell migration, its capability to induce anti-estrogen resistance, and its significant functions in cell cycle regulation. Further highlighted is BCAR3's modulation of immune responses within the tumor microenvironment, a novel area of interest that holds potential for innovative cancer therapies. Looking forward, this review outlines essential future research directions focusing on transcription factor binding studies, isoform-specific expression profiling, therapeutic targeting of BCAR3, and its role in immune cell function. Each segment builds towards a holistic understanding of BCAR3's operational mechanisms, presenting a critical evaluation of its therapeutic potential in oncology. This synthesis aims to not only extend current knowledge but also catalyze further research that could pivotally influence the development of targeted cancer treatments.
Collapse
Affiliation(s)
- Dong Oh Moon
- Department of Biology Education, Daegu University, 201 Daegudae-ro, Gyeongsan-si 38453, Gyeongsangbuk-do, Republic of Korea
| |
Collapse
|
4
|
Yamamoto K, Watanabe-Takano H, Oguri-Nakamura E, Matsuno H, Horikami D, Ishii T, Ohashi R, Kubota Y, Nishiyama K, Murata T, Mochizuki N, Fukuhara S. Rap1 small GTPase is essential for maintaining pulmonary endothelial barrier function in mice. FASEB J 2023; 37:e23310. [PMID: 38010922 DOI: 10.1096/fj.202300830rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 10/25/2023] [Accepted: 11/01/2023] [Indexed: 11/29/2023]
Abstract
Vascular permeability is dynamically but tightly controlled by vascular endothelial (VE)-cadherin-mediated endothelial cell-cell junctions to maintain homeostasis. Thus, impairments of VE-cadherin-mediated cell adhesions lead to hyperpermeability, promoting the development and progression of various disease processes. Notably, the lungs are a highly vulnerable organ wherein pulmonary inflammation and infection result in vascular leakage. Herein, we showed that Rap1, a small GTPase, plays an essential role for maintaining pulmonary endothelial barrier function in mice. Endothelial cell-specific Rap1a/Rap1b double knockout mice exhibited severe pulmonary edema. They also showed vascular leakage in the hearts, but not in the brains. En face analyses of the pulmonary arteries and 3D-immunofluorescence analyses of the lungs revealed that Rap1 potentiates VE-cadherin-mediated endothelial cell-cell junctions through dynamic actin cytoskeleton reorganization. Rap1 inhibits formation of cytoplasmic actin bundles perpendicularly binding VE-cadherin adhesions through inhibition of a Rho-ROCK pathway-induced activation of cytoplasmic nonmuscle myosin II (NM-II). Simultaneously, Rap1 induces junctional NM-II activation to create circumferential actin bundles, which anchor and stabilize VE-cadherin at cell-cell junctions. We also showed that the mice carrying only one allele of either Rap1a or Rap1b out of the two Rap1 genes are more vulnerable to lipopolysaccharide (LPS)-induced pulmonary vascular leakage than wild-type mice, while activation of Rap1 by administration of 007, an activator for Epac, attenuates LPS-induced increase in pulmonary endothelial permeability in wild-type mice. Thus, we demonstrate that Rap1 plays an essential role for maintaining pulmonary endothelial barrier functions under physiological conditions and provides protection against inflammation-induced pulmonary vascular leakage.
Collapse
Affiliation(s)
- Kiyotake Yamamoto
- Department of Molecular Pathophysiology, Institute for Advanced Medical Sciences, Nippon Medical School, Tokyo, Japan
- Department of Pharmaceutical Information Science, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
- Laboratory of Vascular and Cellular Dynamics, Department of Medical Sciences, University of Miyazaki, Miyazaki, Japan
| | - Haruko Watanabe-Takano
- Department of Molecular Pathophysiology, Institute for Advanced Medical Sciences, Nippon Medical School, Tokyo, Japan
| | - Eri Oguri-Nakamura
- Department of Molecular Pathophysiology, Institute for Advanced Medical Sciences, Nippon Medical School, Tokyo, Japan
| | - Hitomi Matsuno
- Department of Molecular Pathophysiology, Institute for Advanced Medical Sciences, Nippon Medical School, Tokyo, Japan
| | - Daiki Horikami
- Department of Animal Radiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Tomohiro Ishii
- Department of Molecular Pathophysiology, Institute for Advanced Medical Sciences, Nippon Medical School, Tokyo, Japan
| | - Ryuji Ohashi
- Department of Integrated Diagnostic Pathology, Nippon Medical School, Tokyo, Japan
| | - Yoshiaki Kubota
- Department of Anatomy, Keio University School of Medicine, Tokyo, Japan
| | - Koichi Nishiyama
- Laboratory of Vascular and Cellular Dynamics, Department of Medical Sciences, University of Miyazaki, Miyazaki, Japan
| | - Takahisa Murata
- Department of Animal Radiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Naoki Mochizuki
- Department of Cell Biology, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan
| | - Shigetomo Fukuhara
- Department of Molecular Pathophysiology, Institute for Advanced Medical Sciences, Nippon Medical School, Tokyo, Japan
| |
Collapse
|
5
|
Kumar S, Stainer A, Dubrulle J, Simpkins C, Cooper JA. Cas phosphorylation regulates focal adhesion assembly. eLife 2023; 12:e90234. [PMID: 37489578 PMCID: PMC10435235 DOI: 10.7554/elife.90234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 07/19/2023] [Indexed: 07/26/2023] Open
Abstract
Integrin-mediated cell attachment rapidly induces tyrosine kinase signaling. Despite years of research, the role of this signaling in integrin activation and focal adhesion assembly is unclear. We provide evidence that the Src-family kinase (SFK) substrate Cas (Crk-associated substrate, p130Cas, BCAR1) is phosphorylated and associated with its Crk/CrkL effectors in clusters that are precursors of focal adhesions. The initial phospho-Cas clusters contain integrin β1 in its inactive, bent closed, conformation. Later, phospho-Cas and total Cas levels decrease as integrin β1 is activated and core focal adhesion proteins including vinculin, talin, kindlin, and paxillin are recruited. Cas is required for cell spreading and focal adhesion assembly in epithelial and fibroblast cells on collagen and fibronectin. Cas cluster formation requires Cas, Crk/CrkL, SFKs, and Rac1 but not vinculin. Rac1 provides positive feedback onto Cas through reactive oxygen, opposed by negative feedback from the ubiquitin proteasome system. The results suggest a two-step model for focal adhesion assembly in which clusters of phospho-Cas, effectors and inactive integrin β1 grow through positive feedback prior to integrin activation and recruitment of core focal adhesion proteins.
Collapse
Affiliation(s)
- Saurav Kumar
- Fred Hutchinson Cancer CenterSeattleUnited States
| | | | | | | | | |
Collapse
|
6
|
Boi R, Bergwall L, Ebefors K, Bergö MO, Nyström J, Buvall L. Podocyte Geranylgeranyl Transferase Type-I Is Essential for Maintenance of the Glomerular Filtration Barrier. J Am Soc Nephrol 2023; 34:641-655. [PMID: 36735952 PMCID: PMC10103324 DOI: 10.1681/asn.0000000000000062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 11/25/2022] [Indexed: 01/22/2023] Open
Abstract
SIGNIFICANCE STATEMENT A tightly regulated actin cytoskeleton attained through balanced activity of RhoGTPases is crucial to maintaining podocyte function. However, how RhoGTPases are regulated by geranylgeranylation, a post-translational modification, has been unexplored. The authors found that loss of the geranylgeranylation enzyme geranylgeranyl transferase type-I (GGTase-I) in podocytes led to progressive albuminuria and foot process effacement in podocyte-specific GGTase-I knockout mice. In cultured podocytes, the absence of geranylgeranylation resulted in altered activity of its downstream substrates Rac1, RhoA, Cdc42, and Rap1, leading to alterations of β1-integrins and actin cytoskeleton structural changes. These findings highlight the importance of geranylgeranylation in the dynamic management of RhoGTPases and Rap1 to control podocyte function, providing new knowledge about podocyte biology and glomerular filtration barrier function. BACKGROUND Impairment of the glomerular filtration barrier is in part attributed to podocyte foot process effacement (FPE), entailing disruption of the actin cytoskeleton and the slit diaphragm. Maintenance of the actin cytoskeleton, which contains a complex signaling network through its connections to slit diaphragm and focal adhesion proteins, is thus considered crucial to preserving podocyte structure and function. A dynamic yet tightly regulated cytoskeleton is attained through balanced activity of RhoGTPases. Most RhoGTPases are post-translationally modified by the enzyme geranylgeranyl transferase type-I (GGTase-I). Although geranylgeranylation has been shown to regulate activities of RhoGTPases and RasGTPase Rap1, its significance in podocytes is unknown. METHODS We used immunofluorescence to localize GGTase-I, which was expressed mainly by podocytes in the glomeruli. To define geranylgeranylation's role in podocytes, we generated podocyte-specific GGTase-I knockout mice. We used transmission electron microscopy to evaluate FPE and measurements of urinary albumin excretion to analyze filtration barrier function. Geranylgeranylation's effects on RhoGTPases and Rap1 function were studied in vitro by knockdown or inhibition of GGTase-I. We used immunocytochemistry to study structural modifications of the actin cytoskeleton and β1 integrins. RESULTS Depletion of GGTase-I in podocytes in vivo resulted in FPE and concomitant early-onset progressive albuminuria. A reduction of GGTase-I activity in cultured podocytes disrupted RhoGTPase balance by markedly increasing activity of RhoA, Rac1, and Cdc42 together with Rap1, resulting in dysregulation of the actin cytoskeleton and altered distribution of β1 integrins. CONCLUSIONS These findings indicate that geranylgeranylation is of crucial importance for the maintenance of the delicate equilibrium of RhoGTPases and Rap1 in podocytes and consequently for the maintenance of glomerular integrity and function.
Collapse
Affiliation(s)
- Roberto Boi
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Lovisa Bergwall
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Kerstin Ebefors
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Martin O. Bergö
- Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Institute of Biosciences and Nutrition, Karolinska Institute, Solna, Sweden
| | - Jenny Nyström
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Lisa Buvall
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Bioscience Renal, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| |
Collapse
|
7
|
Yoshie M, Ohishi K, Ishikawa G, Tsuru A, Kusama K, Azumi M, Tamura K. Small GTP-binding protein Rap1 mediates EGF and HB-EGF signaling and modulates EGF receptor expression in HTR-8/SVneo extravillous trophoblast cells. Reprod Med Biol 2023; 22:e12537. [PMID: 37614815 PMCID: PMC10442520 DOI: 10.1002/rmb2.12537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 08/06/2023] [Accepted: 08/08/2023] [Indexed: 08/25/2023] Open
Abstract
Purpose Extravillous trophoblasts (EVTs) invade the endometrium to establish a fetomaternal interaction during pregnancy. Epidermal growth factor (EGF) and heparin-binding EGF-like growth factor (HB-EGF) stimulate EVT invasion by binding to the EGF receptor (EGFR). We examined the role of the small GTP-binding protein Rap1 in EGF- and HB-EGF-stimulated EVT invasion. Methods Expression of Rap1 in the first-trimester placenta was examined by immunohistochemistry. Effect of EGF or HB-EGF on Rap1 activation (GTP-Rap1) and Rap1 knockdown on invasion was assessed in EVT cell line (HTR-8/SVneo). In addition, effect of Rap1 knockdown and Rap1GAP (a Rap1 inactivator) overexpression on the activation of EGF signaling and EGFR expression were examined. Results Rap1 was expressed by EVTs, villous cytotrophoblasts, and syncytiotrophoblasts in the placenta. EGF and HB-EGF activated Rap1 and promoted invasion of HTR-8/SVneo, and these effects were inhibited by Rap1 knockdown. The EGF- and HB-EGF-induced phosphorylation of AKT, ERK1/2, p38MAPK, and Src was inhibited by Rap1 knockdown. Furthermore, the knockdown of Rap1 reduced the EGFR protein level. Overexpression of Rap1GAP repressed EGF- and HB-EGF-induced Rap1 activation and reduced EGFR expression. Conclusion Rap1 may function as a mediator of EGF and HB-EGF signaling pathways and can modulate EGFR expression in EVTs during placental development.
Collapse
Affiliation(s)
- Mikihiro Yoshie
- Department of Endocrine PharmacologyTokyo University of Pharmacy and Life SciencesTokyoJapan
| | - Kensuke Ohishi
- Department of Endocrine PharmacologyTokyo University of Pharmacy and Life SciencesTokyoJapan
| | - Gen Ishikawa
- Department of ObstetricsMiyagi Children's HospitalSendaiJapan
| | - Atsuya Tsuru
- Department of Endocrine PharmacologyTokyo University of Pharmacy and Life SciencesTokyoJapan
| | - Kazuya Kusama
- Department of Endocrine PharmacologyTokyo University of Pharmacy and Life SciencesTokyoJapan
| | - Mana Azumi
- Department of Endocrine PharmacologyTokyo University of Pharmacy and Life SciencesTokyoJapan
| | - Kazuhiro Tamura
- Department of Endocrine PharmacologyTokyo University of Pharmacy and Life SciencesTokyoJapan
| |
Collapse
|
8
|
Calcium-dependent cAMP mediates the mechanoresponsive behaviour of endothelial cells to high-frequency nanomechanostimulation. Biomaterials 2023; 292:121866. [PMID: 36526351 DOI: 10.1016/j.biomaterials.2022.121866] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 09/10/2022] [Accepted: 10/18/2022] [Indexed: 12/15/2022]
Abstract
The endothelial junction plays a central role in regulating intravascular and interstitial tissue permeability. The ability to manipulate its integrity therefore not only facilitates an improved understanding of its underlying molecular mechanisms but also provides insight into potential therapeutic solutions. Herein, we explore the effects of short-duration nanometer-amplitude MHz-order mechanostimulation on interendothelial junction stability and hence the barrier capacity of endothelial monolayers. Following an initial transient in which the endothelial barrier is permeabilised due to Rho-ROCK-activated actin stress fibre formation and junction disruption typical of a cell's response to insults, we observe, quite uniquely, the integrity of the endothelial barrier to not only spontaneously recover but also to be enhanced considerably-without the need for additional stimuli or intervention. Central to this peculiar biphasic response, which has not been observed with other stimuli to date, is the role of second messenger calcium and cyclic adenosine monophosphate (cAMP) signalling. We show that intracellular Ca2+, modulated by the high frequency excitation, is responsible for activating reorganisation of the actin cytoskeleton in the barrier recovery phase, in which circumferential actin bundles are formed to stabilise the adherens junctions via a cAMP-mediated Epac1-Rap1 pathway. Despite the short-duration stimulation (8 min), the approximate 4-fold enhancement in the transendothelial electrical resistance (TEER) of endothelial cells from different tissue sources, and the corresponding reduction in paracellular permeability, was found to persist over hours. The effect can further be extended through multiple treatments without resulting in hyperpermeabilisation of the barrier, as found with prolonged use of chemical stimuli, through which only 1.1- to 1.2-fold improvement in TEER has been reported. Such an ability to regulate and enhance endothelial barrier capacity is particularly useful in the development of in vitro barrier models that more closely resemble their in vivo counterparts.
Collapse
|
9
|
Yadav V, Sharma K, Bhattacharya S, Talwar P, Purohit PK, Saini N. RETRACTED: hsa-miR-23a~27a~24-2 cluster members inhibit aggressiveness of breast cancer cells by commonly targeting NCOA1, NLK and RAP1B. Life Sci 2022; 307:120906. [PMID: 36007610 DOI: 10.1016/j.lfs.2022.120906] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 08/10/2022] [Accepted: 08/18/2022] [Indexed: 11/28/2022]
Abstract
This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. The corresponding author notified the journal of three examples of image duplication within the published article (two in Figure 3D and one in Figure 4A), and requested a corrigendum. As per journal policy when considering corrigendum requests, the journal requested the authors to provide source data relating to these affected figures. The editorial team noticed 12 additional suspected image duplications within the supplied source data and the corresponding author was informed. Upon submission of revised source data, the editorial team noticed two new suspected image duplications. The editorial team have concerns about the provenance of the data and therefore the Editor-in-Chief decided to retract the article.
Collapse
Affiliation(s)
- Vikas Yadav
- Functional Genomics Unit, CSIR-Institute of Genomics and Integrative Biology (IGIB), Mall Road, 110007, Delhi, India
| | - Kritika Sharma
- Functional Genomics Unit, CSIR-Institute of Genomics and Integrative Biology (IGIB), Mall Road, 110007, Delhi, India
| | - Sushant Bhattacharya
- Functional Genomics Unit, CSIR-Institute of Genomics and Integrative Biology (IGIB), Mall Road, 110007, Delhi, India
| | - Puneet Talwar
- Institute of Human Behaviour & Allied Sciences (IHBAS), Delhi, India
| | - Paresh Kumar Purohit
- Functional Genomics Unit, CSIR-Institute of Genomics and Integrative Biology (IGIB), Mall Road, 110007, Delhi, India; Academy of Scientific & Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Neeru Saini
- Functional Genomics Unit, CSIR-Institute of Genomics and Integrative Biology (IGIB), Mall Road, 110007, Delhi, India; Academy of Scientific & Innovative Research (AcSIR), Ghaziabad 201002, India.
| |
Collapse
|
10
|
Khan A, Ni W, Baltazar T, Lopez-Giraldez F, Pober JS, Pierce RW. ArhGEF12 activates Rap1A and not RhoA in human dermal microvascular endothelial cells to reduce tumor necrosis factor-induced leak. FASEB J 2022; 36:e22254. [PMID: 35294066 PMCID: PMC9103844 DOI: 10.1096/fj.202101873rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 03/01/2022] [Accepted: 03/03/2022] [Indexed: 12/31/2022]
Abstract
Overwhelming inflammation in the setting of acute critical illness induces capillary leak resulting in hypovolemia, edema, tissue dysoxia, organ failure and even death. The tight junction (TJ)-dependent capillary barrier is regulated by small GTPases, but the specific regulatory molecules most active in this vascular segment under such circumstances are not well described. We set out to identify GTPase regulatory molecules specific to endothelial cells (EC) that form TJs. Transcriptional profiling of confluent monolayers of TJ-forming human dermal microvascular ECs (HDMECs) and adherens junction only forming-human umbilical vein EC (HUVECs) demonstrate ARHGEF12 is basally expressed at higher levels and is only downregulated in HDMECs by junction-disrupting tumor necrosis factor (TNF). HDMECs depleted of ArhGEF12 by siRNA demonstrate a significantly exacerbated TNF-induced decrease in trans-endothelial electrical resistance and disruption of TJ continuous staining. ArhGEF12 is established as a RhoA-GEF in HUVECs and its knock down would be expected to reduce RhoA activity and barrier disruption. Pulldown of active GEFs from HDMECs depleted of ArhGEF12 and treated with TNF show decreased GTP-bound Rap1A after four hours but increased GTP-bound RhoA after 12 h. In cell-free assays, ArhGEF12 immunoprecipitated from HDMECs is able to activate both Rap1A and RhoA, but not act on Rap2A-C, RhoB-C, or even Rap1B which shares 95% sequence identity with Rap1A. We conclude that in TJ-forming HDMECs, ArhGEF12 selectively activates Rap1A to limit capillary barrier disruption in a mechanism independent of cAMP-mediated Epac1 activation.
Collapse
Affiliation(s)
- Alamzeb Khan
- Department of Pediatrics, Yale School of Medicine, Yale University
| | - Weiming Ni
- Department of Pediatrics, Yale School of Medicine, Yale University
| | - Tania Baltazar
- Department of Immunobiology, Yale School of Medicine, Yale University
| | | | - Jordan S. Pober
- Department of Immunobiology, Yale School of Medicine, Yale University
| | | |
Collapse
|
11
|
Yamamoto K, Takagi Y, Ando K, Fukuhara S. Rap1 Small GTPase Regulates Vascular Endothelial-Cadherin-Mediated Endothelial Cell-Cell Junctions and Vascular Permeability. Biol Pharm Bull 2021; 44:1371-1379. [PMID: 34602545 DOI: 10.1248/bpb.b21-00504] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The vascular permeability of the endothelium is finely controlled by vascular endothelial (VE)-cadherin-mediated endothelial cell-cell junctions. In the majority of normal adult tissues, endothelial cells in blood vessels maintain vascular permeability at a relatively low level, while in response to inflammation, they limit vascular barrier function to induce plasma leakage and extravasation of immune cells as a defense mechanism. Thus, the dynamic but also simultaneously tight regulation of vascular permeability by endothelial cells is responsible for maintaining homeostasis and, as such, impairments of its underlying mechanisms result in hyperpermeability, leading to the development and progression of various diseases including coronavirus disease 2019 (COVID-19), a newly emerging infectious disease. Recently, increasing numbers of studies have been unveiling the important role of Rap1, a small guanosine 5'-triphosphatase (GTPase) belonging to the Ras superfamily, in the regulation of vascular permeability. Rap1 enhances VE-cadherin-mediated endothelial cell-cell junctions to potentiate vascular barrier functions via dynamic reorganization of the actin cytoskeleton. Importantly, Rap1 signaling activation reportedly improves vascular barrier function in animal models of various diseases associated with vascular hyperpermeability, suggesting that Rap1 might be an ideal target for drugs intended to prevent vascular barrier dysfunction. Here, we describe recent progress in understanding the mechanisms by which Rap1 potentiates VE-cadherin-mediated endothelial cell-cell adhesions and vascular barrier function. We also discuss how alterations in Rap1 signaling are related to vascular barrier dysfunction in diseases such as acute pulmonary injury and malignancies. In addition, we examine the possibility of Rap1 signaling as a target of drugs for treating diseases associated with vascular hyperpermeability.
Collapse
Affiliation(s)
- Kiyotake Yamamoto
- Department of Molecular Pathophysiology, Institute for Advanced Medical Sciences, Nippon Medical School
| | - Yuki Takagi
- Department of Molecular Pathophysiology, Institute for Advanced Medical Sciences, Nippon Medical School
| | - Koji Ando
- Department of Molecular Pathophysiology, Institute for Advanced Medical Sciences, Nippon Medical School
| | - Shigetomo Fukuhara
- Department of Molecular Pathophysiology, Institute for Advanced Medical Sciences, Nippon Medical School
| |
Collapse
|
12
|
Kim D, Kim W, Jeon TJ. Reversible function of RapA with the C-terminus of RapC in Dictyostelium. J Microbiol 2021; 59:848-853. [PMID: 34449058 DOI: 10.1007/s12275-021-1400-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 08/06/2021] [Accepted: 08/13/2021] [Indexed: 10/20/2022]
Abstract
Rap small GTPases are involved in diverse signaling pathways associated with cell growth, proliferation, and cell migration. There are three Rap proteins in Dictyostelium, RapA, RapB, and RapC. RapA is a key regulator in the control of cell adhesion and migration. Recently RapA and RapC have been reported to have opposite functions in the regulation of cellular processes. In this study, we demonstrate that the C-terminus of RapC, which is not found in RapA, is essential for the opposite functions of RapC and is able to reverse the functions of RapA when fused to the tail of RapA. Cells lacking RapC displayed several defective phenotypes, including spread morphology, strong adhesion, and decreased cell migration compared to wild-type cells. These phenotypes were rescued by full-length RapC, but not by RapC missing the C-terminus. Furthermore, recombinant RapA fused with the C-terminus of RapC completely recovered the phenotypes of rapC null cells, indicating that the functions of RapA were modified to become similar to those of RapC by the C-terminus of RapC with respect to cell morphology, cell adhesion and migration, cytokinesis, and development. These results suggest that the C-terminal residues of RapC are able to suppress and change the functions of other Ras proteins in Ras oncogenic signaling pathways.
Collapse
Affiliation(s)
- Dongju Kim
- Department of Integrative Biological Sciences & BK21 FOUR Educational Research Group for Age-associated Disorder Control Technology, Chosun University, Gwangju, 61452, Republic of Korea
| | - Wonbum Kim
- Department of Integrative Biological Sciences & BK21 FOUR Educational Research Group for Age-associated Disorder Control Technology, Chosun University, Gwangju, 61452, Republic of Korea
| | - Taeck Joong Jeon
- Department of Integrative Biological Sciences & BK21 FOUR Educational Research Group for Age-associated Disorder Control Technology, Chosun University, Gwangju, 61452, Republic of Korea.
| |
Collapse
|
13
|
Fahim AM, Elshikh MS, Darwish NM. Synthesis, Antitumor Activity, Molecular Docking and DFT Study of Novel Pyrimidiopyrazole Derivatives. Curr Comput Aided Drug Des 2021; 16:486-499. [PMID: 31288728 DOI: 10.2174/1573409915666190710094425] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 04/30/2019] [Accepted: 06/15/2019] [Indexed: 11/22/2022]
Abstract
BACKGROUND In this investigation, 2-cyano-N-(2,4-dioxo-1,2,3,4-tetrahydropyrimidin-5-yl) acetamide (3) reacts with dimethylformamide dimethyl acetal (DMF-DMA) to afford the corresponding (E)- 2-cyano-3-(dimethylamino)-N-(2,4-dioxo-1,2,3,4-tetrahydropyrimidin-5-yl)acrylam-ide (4) utilizing microwave irradiation. The condensation reactions of acrylamide derivative 4 with hydrazine derivatives obtain pyrazole derivatives 6a and 6b; respectively. The synthesized compounds demonstrate in vitro antitumor activity against liver tumor cell line HepG2. Furthermore, additional studies were carried out on the most effective compound 6b to evaluate the potential interaction against 4hdq synthase complex with ΔE= -4.5Kcal/mol and with short distance = 1.727Å and 2.027Å, respectively. The comprehensive theoretical studies of compounds 6a and 6b is based on bond length, bond angles and energy gap HOMO-LUMO. In addition, the vibrational frequencies of optimized compounds 6a and 6b were examined through DFT/B3LYP/6+31G(d) basis set. METHODS In this research, synthesis of novel pyrimidiopyrazole derivatives calculated the computational studies to find suitable drug-receptor interactions and biological activity. RESULTS AND DISCUSSION The synthesized pyrimidiopyrazole derivative 6b exhibited high antitumor activity IC50 =12.6 μg/ml and interacted it with 4hdq synthase complex with ΔE=-4.5Kcal/mol and with short distance = 1.727Å and 2.027Å. Furthermore, the optimized compounds utilize Gaussian 09W. CONCLUSION In the optimized pyrimidiopyrazole derivatives, 6b showed better antitumor activity HeG-2 against 5-flurouracil due to its energy and confirmed more potent of hydrogen bond interaction with protein pocket.
Collapse
Affiliation(s)
- Asmaa M Fahim
- Green Chemistry Department, National Research Center, Dokki, P.O. Box. 12622 Cairo, Egypt
| | - Mohamed S Elshikh
- Department of Botany and Microbiology, College of Science, King Saud University, P.O. Box. 2455, Riyadh 11451, Saudi Arabia
| | - Noura M Darwish
- Biochemistry Department, Faculty of Science Ain Shams University, Abbasaya, P.O. Box. 11566, Cairo, Egypt
| |
Collapse
|
14
|
Fahim AM, Ismael EHI, Elsayed GH, Farag AM. Synthesis, antimicrobial, anti-proliferative activities, molecular docking and DFT studies of novel pyrazolo[5,1-c][1, 2, 4]triazine-3-carboxamide derivatives. J Biomol Struct Dyn 2021; 40:9177-9193. [PMID: 34106038 DOI: 10.1080/07391102.2021.1930582] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In this investigation, we studied the reactivity of 5-aminouracil (1) with ethyl cyanoacetate (2) utilizing microwave irradiation to afford the corresponding 2-cyano-N-(2,4-dioxo-1,2,3,4-tetrahydropyrimidin-5-yl)acetamide (3) in excellent yield. The electrophilic azo-coupling reaction of acetamide 3 with aromatic diazonium salts afforded the corresponding hydrazone derivatives 4a-d. The Michael addition cyclization of hydrazone in pyridine to give pyrazolo[5,1-c][1, 2, 4]triazine-3-carboxamide 5a-d derivatives. The obtained compounds were elucidated against antimicrobial activity and antitumor activity breast cancer cells (MCF-7) and liver cancer cells (HepG2) utilized MTT assay. Compounds 5b, 5c and 5d revealed more inhibitory influence on MCF7 and HepG2 growth than the reference drug doxorubicin (Dox) after 48 h incubation. Furthermore, molecular docking studies were carried out on one of the most effective compound 4-amino-N-(2,4-dioxo-1,2,3,4-tetrahydropyrimidin-5-yl)-7-(4-fluorophenyl) pyrazole [5,1-c][1, 2, 4]triazine-3-carboxamide (5c) (TFC) with (PDB: 3t88), (PDB: 2wje) , (PDB: 4ynt), (PDB: 1tgh), (PDB: 4hdq) and (PDB: 3pxe) which attached with different proteins with different energies and shortage bond distance. Also; the comprehensive theoretical and experimental mechanical studies of compound TFC and TMC were compatible with FTIR and 1H NMR spectral data. The optimized molecular structure of TFC with FTIR was examined via DFT/ B3LYP/6-31G (d) level.Communicated by Ramaswamy H. Sarma.
Collapse
Affiliation(s)
- Asmaa M Fahim
- Department of Green Chemistry, National Research Center, Dokki, Cairo, Egypt
| | - Eman H I Ismael
- Department of Organometallic and Organ Metalloid Chemistry, National Research Centre, Dokki, Cairo, Egypt
| | - Ghada H Elsayed
- Hormones Department, National Research Centre, Dokki, Cairo, Egypt
| | - Ahmad M Farag
- Department of Chemistry, Faculty of Science, Cairo University, Giza, Cairo, Egypt
| |
Collapse
|
15
|
Chen YC, Lai YS, Hsuuw YD, Chang KT. Withholding of M-CSF Supplement Reprograms Macrophages to M2-Like via Endogenous CSF-1 Activation. Int J Mol Sci 2021; 22:3532. [PMID: 33805444 PMCID: PMC8037162 DOI: 10.3390/ijms22073532] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 03/13/2021] [Accepted: 03/25/2021] [Indexed: 12/17/2022] Open
Abstract
Macrophage colony-stimulating factor (M-CSF or CSF-1) is known to have a broad range of actions on myeloid cells maturation, including the regulation of macrophage differentiation, proliferation and survival. Macrophages generated by M-CSF stimulus have been proposed to be alternatively activated or M2 phenotype. M-CSF is commonly overexpressed by tumors and is also known to enhance tumor growth and aggressiveness via stimulating pro-tumor activities of tumor-associated macrophages (TAMs). Currently, inhibition of CSF-1/CSF-1R interaction by therapeutic antibody to deplete TAMs and their pro-tumor functions is becoming a prevalent strategy in cancer therapy. However, its antitumor activity shows a limited single-agent effect. Therefore, macrophages in response to M-CSF interruption are pending for further investigation. To achieve this study, bone marrow derived macrophages were generated in vitro by M-CSF stimulation for 7 days and then continuously grown until day 21 in M-CSF absence. A selective pressure for cell survival was initiated after withdrawal of M-CSF. The surviving cells were more prone to M2-like phenotype, even after receiving interleukin-4 (IL-4) stimulation. The transcriptome analysis unveiled that endogenous CSF-1 level was dramatically up-regulated and numerous genes downstream to CSF-1 covering tumor necrosis factor (TNF), ras-related protein 1 (Rap1) and phosphatidylinositol 3-kinase (PI3K)-protein kinase B (AKT) signaling pathway were significantly modulated, especially for proliferation, migration and adhesion. Moreover, the phenomenal increase of miR-21-5p and genes related to pro-tumor activity were observed in parallel. In summary, withholding of CSF-1/CSF-1R interaction would rather augment than suspend the M-CSF-driven pro-tumor activities of M2 macrophages in a long run.
Collapse
Affiliation(s)
- Yu-Chih Chen
- Graduate Institute of Bioresources, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan; christian--
| | - Yin-Siew Lai
- Research Center for Animal Biologics, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan;
| | - Yan-Der Hsuuw
- Department of Tropical Agriculture and International Cooperation, Pingtung 91201, Taiwan;
| | - Ko-Tung Chang
- Research Center for Animal Biologics, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan;
- Flow Cytometry Center, Precision Instruments Center, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
| |
Collapse
|
16
|
Xie Y, Wang Y, Xiang W, Wang Q, Cao Y. Molecular Mechanisms of the Action of Myricetin in Cancer. Mini Rev Med Chem 2020; 20:123-133. [PMID: 31648635 DOI: 10.2174/1389557519666191018112756] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 03/31/2019] [Accepted: 09/26/2019] [Indexed: 02/07/2023]
Abstract
Natural compounds, such as paclitaxel and camptothecin, have great effects on the treatment of tumors. Such natural chemicals often achieve anti-tumor effects through a variety of mechanisms. Therefore, it is of great significance to conduct further studies on the anticancer mechanism of natural anticancer agents to lay a solid foundation for the development of new drugs. Myricetin, originally isolated from Myrica nagi, is a natural pigment of flavonoids that can inhibit the growth of cancer cells (such as liver cancer, rectal cancer, skin cancer and lung cancer, etc.). It can regulate many intracellular activities (such as anti-inflammatory and blood lipids regulation) and can even be bacteriostatic. The purpose of this paper is to outline the molecular pathways of the anticancer effects of myricetin, including the effect on cancer cell death, proliferation, angiogenesis, metastasis and cell signaling pathway.
Collapse
Affiliation(s)
- Yutao Xie
- Department of Pharmacy, Nanchong Center Hospital, The Second Clinical Medical College, North Sichuan Medical College (University), Nanchong, 637000, Sichuan, China
| | - Yunlong Wang
- Department of Pharmacy, Nanchong Center Hospital, The Second Clinical Medical College, North Sichuan Medical College (University), Nanchong, 637000, Sichuan, China
| | - Wei Xiang
- Department of Pharmacy, Nanchong Center Hospital, The Second Clinical Medical College, North Sichuan Medical College (University), Nanchong, 637000, Sichuan, China
| | - Qiaoying Wang
- Department of Cardiothoracic Surgery, Nanchong Center Hospital, The Second Clinical Medical College, North Sichuan Medical College (University), Nanchong, 637000, Sichuan, China
| | - Yajun Cao
- Department of Pharmacy, Nanchong Center Hospital, The Second Clinical Medical College, North Sichuan Medical College (University), Nanchong, 637000, Sichuan, China
| |
Collapse
|
17
|
Epac1 Is Crucial for Maintenance of Endothelial Barrier Function through A Mechanism Partly Independent of Rac1. Cells 2020; 9:cells9102170. [PMID: 32992982 PMCID: PMC7601253 DOI: 10.3390/cells9102170] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 09/17/2020] [Accepted: 09/23/2020] [Indexed: 12/20/2022] Open
Abstract
Epac1 (exchange protein activated by cAMP) stabilizes the endothelial barrier, but detailed studies are limited by the side effects of pharmacological Epac1 modulators and transient transfections. Here, we compare the key properties of barriers between endothelial cells derived from wild-type (WT) and Epac1-knockout (KO) mice myocardium. We found that KO cell layers, unlike WT layers, had low and cAMP-insensitive trans-endothelial resistance (TER). They also had fragmented VE-cadherin staining despite having augmented cAMP levels and increased protein expression of Rap1, Rac1, RhoA, and VE-cadherin. The simultaneous direct activation of Rac1 and RhoA by CN04 compensated Epac1 loss, since TER was increased. In KO-cells, inhibition of Rac1 activity had no additional effect on TER, suggesting that other mechanisms compensate the inhibition of the Rac1 function to preserve barrier properties. In summary, Epac1 is crucial for baseline and cAMP-mediated barrier stabilization through mechanisms that are at least partially independent of Rac1.
Collapse
|
18
|
Abstract
RAS was identified as a human oncogene in the early 1980s and subsequently found to be mutated in nearly 30% of all human cancers. More importantly, RAS plays a central role in driving tumor development and maintenance. Despite decades of effort, there remain no FDA approved drugs that directly inhibit RAS. The prevalence of RAS mutations in cancer and the lack of effective anti-RAS therapies stem from RAS' core role in growth factor signaling, unique structural features, and biochemistry. However, recent advances have brought promising new drugs to clinical trials and shone a ray of hope in the field. Here, we will exposit the details of RAS biology that illustrate its key role in cell signaling and shed light on the difficulties in therapeutically targeting RAS. Furthermore, past and current efforts to develop RAS inhibitors will be discussed in depth.
Collapse
Affiliation(s)
- J Matthew Rhett
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States; Ralph H. Johnson VA Medical Center, Charleston, SC, United States
| | - Imran Khan
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States; Ralph H. Johnson VA Medical Center, Charleston, SC, United States
| | - John P O'Bryan
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States; Ralph H. Johnson VA Medical Center, Charleston, SC, United States.
| |
Collapse
|
19
|
Liu M, Banerjee R, Rossa C, D'Silva NJ. RAP1-RAC1 Signaling Has an Important Role in Adhesion and Migration in HNSCC. J Dent Res 2020; 99:959-968. [PMID: 32401565 DOI: 10.1177/0022034520917058] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Cell-cell adhesion is a key mechanism to control tissue integrity and migration. In head and neck squamous cell carcinoma (HNSCC), cell migration facilitates distant metastases and is correlated with poor prognosis. RAP1, a ras-like protein, has an important role in the progression of HNSCC. RAC1 is an integrin-linked, ras-like protein that promotes cell migration. Here we show that loss of cell-cell adhesion is correlated with inactivation of RAP1 confirmed by 2 different biochemical approaches. RAP1 activation is required for cell-matrix adhesion confirmed by adhesion to fibronectin-coated plates with cells that have biochemically activated RAP1. This effect is reversed when RAP1 is inactivated. In addition, RAP1GTP-mediated adhesion is only facilitated through α5β1 integrin complex and is not a function of either α5 or β1 integrin alone. Moreover, the inside-out signaling of RAP1 activation is coordinated with RAC1 activation. These findings show that RAP1 has a prominent role in cell-matrix adhesion via extracellular matrix molecule fibronectin-induced α5β1 integrin and supports a critical role for the RAP1/RAC1 signaling axis in HNSCC cell migration.
Collapse
Affiliation(s)
- M Liu
- Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - R Banerjee
- Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - C Rossa
- Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI, USA.,Department of Diagnosis and Surgery, School of Dentistry at Araraquara, UNESP-Univ Estadual Paulista, Araraquara, SP, Brazil
| | - N J D'Silva
- Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI, USA.,Department of Pathology, Medical School; University of Michigan, Ann Arbor, MI, USA
| |
Collapse
|
20
|
Nussinov R, Jang H, Zhang M, Tsai CJ, Sablina AA. The Mystery of Rap1 Suppression of Oncogenic Ras. Trends Cancer 2020; 6:369-379. [PMID: 32249186 PMCID: PMC7211489 DOI: 10.1016/j.trecan.2020.02.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 01/30/2020] [Accepted: 02/03/2020] [Indexed: 12/11/2022]
Abstract
Decades ago, Rap1, a small GTPase very similar to Ras, was observed to suppress oncogenic Ras phenotype, reverting its transformation. The proposed reason, persisting since, has been competition between Ras and Rap1 for a common target. Yet, none was found. There was also Rap1's puzzling suppression of Raf-1 versus activation of BRAF. Reemerging interest in Rap1 envisages capturing its Ras suppression action by inhibitors. Here, we review the literature and resolve the enigma. In vivo oncogenic Ras exists in isoform-distinct nanoclusters. The presence of Rap1 within the nanoclusters reduces the number of the clustered oncogenic Ras molecules, thus suppressing Raf-1 activation and mitogen-activated protein kinase (MAPK) signaling. Nanoclustering suggests that Rap1 suppression is Ras isoform dependent. Altogether, a potent Rap1-like inhibitor appears unlikely.
Collapse
Affiliation(s)
- Ruth Nussinov
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research, National Cancer Institute at Frederick, Frederick, MD 21702, USA; Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
| | - Hyunbum Jang
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research, National Cancer Institute at Frederick, Frederick, MD 21702, USA
| | - Mingzhen Zhang
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research, National Cancer Institute at Frederick, Frederick, MD 21702, USA
| | - Chung-Jung Tsai
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research, National Cancer Institute at Frederick, Frederick, MD 21702, USA
| | - Anna A Sablina
- VIB Center for the Biology of Disease and KU Leuven Department of Oncology, Leuven Cancer Institute, Leuven, Belgium
| |
Collapse
|
21
|
Fray MA, Charpentier JC, Sylvain NR, Seminario MC, Bunnell SC. Vav2 lacks Ca 2+ entry-promoting scaffolding functions unique to Vav1 and inhibits T cell activation via Cdc42. J Cell Sci 2020; 133:jcs238337. [PMID: 31974114 PMCID: PMC7075049 DOI: 10.1242/jcs.238337] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 01/06/2020] [Indexed: 12/16/2022] Open
Abstract
Vav family guanine nucleotide exchange factors (GEFs) are essential regulators of immune function. Despite their structural similarity, Vav1 promotes and Vav2 opposes T cell receptor (TCR)-induced Ca2+ entry. By using a Vav1-deficient Jurkat T cell line, we find that Vav1 facilitates Ca2+ entry via non-catalytic scaffolding functions that are encoded by the catalytic core of Vav1 and flanking linker regions. We implicate, in this scaffolding function, a previously undescribed polybasic motif that is strictly conserved in Vav1 and absent from Vav2 in tetrapods. Conversely, the catalytic activity of Vav2 contributes to the suppression of TCR-mediated Ca2+ entry. By performing an in vivo 'GEF trapping' assay in intact cells, we demonstrate that Cdc42 interacts with the catalytic surface of Vav2 but not Vav1, and that Vav1 discriminates Cdc42 from Rac1 via F56 (W56 in Rac1). Finally, the Cdc42-specific inhibitor ZCL278 and the shRNA-mediated suppression of Cdc42 each prevent the inhibition of TCR-induced Ca2+ entry by Vav2. These findings define stark differences in the functions of Vav1 and Vav2, and provide an explanation for the differential usage of these Vav isoforms by immune subpopulations.
Collapse
Affiliation(s)
- Michael A Fray
- Program in Immunology, Department of Immunology, Tufts University School of Medicine, Boston, MA 02111, USA
| | - John C Charpentier
- Department of Biology, University of Massachusetts Boston, Boston, MA 02125, USA
| | - Nicholas R Sylvain
- Program in Immunology, Department of Immunology, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Maria-Cristina Seminario
- Program in Immunology, Department of Immunology, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Stephen C Bunnell
- Program in Immunology, Department of Immunology, Tufts University School of Medicine, Boston, MA 02111, USA
| |
Collapse
|
22
|
Girón-Pérez DA, Vadillo E, Schnoor M, Santos-Argumedo L. Myo1e modulates the recruitment of activated B cells to inguinal lymph nodes. J Cell Sci 2020; 133:jcs.235275. [PMID: 31964710 DOI: 10.1242/jcs.235275] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 01/06/2020] [Indexed: 12/31/2022] Open
Abstract
The inclusion of lymphocytes in high endothelial venules and their migration to the lymph nodes are critical steps in the immune response. Cell migration is regulated by the actin cytoskeleton and myosins. Myo1e is a long-tailed class I myosin and is highly expressed in B cells, which have not been studied in the context of cell migration. By using intravital microscopy in an in vivo model and performing in vitro experiments, we studied the relevance of Myo1e for the adhesion and inclusion of activated B cells in high endothelial venules. We observed reduced expression of integrins and F-actin in the membrane protrusions of B lymphocytes, which might be explained by deficiencies in vesicular trafficking. Interestingly, the lack of Myo1e reduced the phosphorylation of focal adhesion kinase (FAK; also known as PTK2), AKT (also known as AKT1) and RAC-1, disturbing the FAK-PI3K-RAC-1 signaling pathway. Taken together, our results indicate a critical role of Myo1e in the mechanism of B-cell adhesion and migration.
Collapse
Affiliation(s)
- Daniel A Girón-Pérez
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, CP 07360, Mexico City, Mexico
| | - Eduardo Vadillo
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, CP 07360, Mexico City, Mexico
| | - Michael Schnoor
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, CP 07360, Mexico City, Mexico
| | - Leopoldo Santos-Argumedo
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, CP 07360, Mexico City, Mexico
| |
Collapse
|
23
|
Fan M, Ma X, Wang F, Zhou Z, Zhang J, Zhou D, Hong Y, Wang Y, Wang G, Dong Q. MicroRNA-30b-5p functions as a metastasis suppressor in colorectal cancer by targeting Rap1b. Cancer Lett 2020; 477:144-156. [PMID: 32112903 DOI: 10.1016/j.canlet.2020.02.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 01/24/2020] [Accepted: 02/14/2020] [Indexed: 12/24/2022]
Abstract
Colorectal liver metastasis (CRLM) is the leading cause of death in patients with colorectal cancer (CRC). MiR-30b-5p can function as an oncogene or tumor suppressor in cancers, but its role in CRLM is still unknown. Here, we found that miR-30b-5p overexpression suppressed the invasion, migration, adhesion, and motility of HCT116 and LoVo cells. The expression of EMT (Zeb1, Snail, and vimentin) and adhesion-related proteins (p-paxillin and p-Src) was decreased. We validated Rap1b, a Ras family small GTPase that regulates cell adhesion and mobility, as the direct and functional target of miR-30b-5p. Rap1b overexpression rescued the aggressive characteristics of CRC cells that were inhibited by miR-30b-5p. Rap1b knockdown suppressed invasion and migration and decreased CRC cell-matrix adhesion and spreading, which was consistent with the results of miR-30b-5p overexpression. Further in vivo experiments demonstrated that miR-30b-5p overexpression inhibited CRLM, but Rap1b rescue attenuated the inhibitory effect of miR-30b-5p. In addition, miR-30b-5p was downregulated in CRC specimens, and Rap1b showed a negative correlation with miR-30b-5p expression in primary CRC and LM tissues. These results indicate that miR-30b-5p functions as a metastasis suppressor by targeting Rap1b and may provide a new target for the treatment of CRLM.
Collapse
Affiliation(s)
- Mengjing Fan
- Biomedical Research Center, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Ximei Ma
- Department of General Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Feifan Wang
- Department of Urology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Zhuha Zhou
- Department of General Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jing Zhang
- Biomedical Research Center, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Difan Zhou
- Department of General Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yiyang Hong
- Biomedical Research Center, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yihong Wang
- Department of Pathology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Guanyu Wang
- Department of General Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
| | - Qinghua Dong
- Biomedical Research Center, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China; Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education, China.
| |
Collapse
|
24
|
Nikulina E, Gkioka V, Siddiq MM, Mellado W, Hilaire M, Cain CR, Hannila SS, Filbin MT. Myelin-associated glycoprotein inhibits neurite outgrowth through inactivation of the small GTPase Rap1. FEBS Lett 2020; 594:1389-1402. [PMID: 31985825 DOI: 10.1002/1873-3468.13740] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 01/08/2020] [Accepted: 01/09/2020] [Indexed: 11/05/2022]
Abstract
Rap1 is a small GTPase that has been implicated in dendritic development and plasticity. In this study, we investigated the role of Rap1 in axonal growth and its activation in response to neurotrophins and myelin-associated inhibitors. We report that Rap1 is activated by brain-derived neurotrophic factor and that this activation can be blocked by myelin-associated glycoprotein (MAG) or central nervous system myelin, which also induced increases in Rap1GAP1 levels. In addition, we demonstrate that adenoviral overexpression of Rap1 enhances neurite outgrowth in the presence of MAG and myelin, while inhibition of Rap1 activity through overexpression of Rap1GAP1 blocks neurite outgrowth. These findings suggest that Rap1GAP1 negatively regulates neurite outgrowth, making it a potential therapeutic target to promote axonal regeneration.
Collapse
Affiliation(s)
- Elena Nikulina
- Department of Biological Sciences, Hunter College, City University of New York, NY, USA
| | - Vasiliki Gkioka
- Department of Biological Sciences, Hunter College, City University of New York, NY, USA
| | - Mustafa M Siddiq
- Icahn Medical Institute 12-52, Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, NY, USA
| | | | - Melissa Hilaire
- Department of Biological Sciences, Hunter College, City University of New York, NY, USA
| | - Christine R Cain
- Department of Biological Sciences, Hunter College, City University of New York, NY, USA
| | - Sari S Hannila
- Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Marie T Filbin
- Department of Biological Sciences, Hunter College, City University of New York, NY, USA
| |
Collapse
|
25
|
Guan X, Guan X, Dong C, Jiao Z. Rho GTPases and related signaling complexes in cell migration and invasion. Exp Cell Res 2020; 388:111824. [PMID: 31926148 DOI: 10.1016/j.yexcr.2020.111824] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Revised: 01/07/2020] [Accepted: 01/08/2020] [Indexed: 12/16/2022]
Abstract
Cell migration and invasion play an important role in the development of cancer. Cell migration is associated with several specific actin filament-based structures, including lamellipodia, filopodia, invadopodia and blebs, and with cell-cell adhesion, cell-extracellular matrix adhesion. Migration occurs via different modes, human epithelial cancer cells mainly migrate collectively, while in vivo imaging studies in laboratory animals have found that most cells migrate as single cells. Rho GTPases play an important role in the process of cell migration, and several Rho GTPase-related signaling complexes are also involved. However, the exact mechanism by which these signaling complexes act remains unclear. This paper reviews how Rho GTPases and related signaling complexes interact with other proteins, how their expression is regulated, how tumor microenvironment-related factors play a role in invasion and metastasis, and the mechanism of these complex signaling networks in cell migration and invasion.
Collapse
Affiliation(s)
- Xiaoying Guan
- Pathology Department, Lanzhou University Second Hospital, Lanzhou, 730030, Gansu, China
| | - Xiaoli Guan
- General Medicine Department, Lanzhou University Second Hospital, Lanzhou, 730030, Gansu, China
| | - Chi Dong
- Pathology Department, Lanzhou University Second Hospital, Lanzhou, 730030, Gansu, China
| | - Zuoyi Jiao
- The First Department of General Surgery, Lanzhou University Second Hospital, Lanzhou, 730030, Gansu, China.
| |
Collapse
|
26
|
Lin X, Huang Y, Sun Y, Tan X, Ouyang J, Zhao B, Wang Y, Xing X, Liu J. 4E-BP1 Thr46 Phosphorylation Association with Poor Prognosis in Quantitative Phosphoproteomics of Portal Vein Tumor Thrombus Revealed that 4E-BP1Thr46 Phosphorylation is Associated with Poor Prognosis in HCC. Cancer Manag Res 2020; 12:103-115. [PMID: 32021427 PMCID: PMC6954833 DOI: 10.2147/cmar.s230849] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 11/30/2019] [Indexed: 12/24/2022] Open
Abstract
Purpose Early formation of portal vein tumor thrombosis (PVTT) is a key characteristic of hepatocellular carcinoma (HCC) metastasis, but to date, the aetiology of PVTT in HCC metastasis is largely unknown. We aim to find highly sensitive and specific biomarkers for the prediction of HCC prognosis. Patients and methods We used isobaric tags for relative and absolute quantitation (iTRAQ) based quantitative phosphoproteomics approach to investigate the molecular signatures of the HCC with PVTT in primary HCC tissues, surrounding non-cancerous tissues and PVTT tissues. The different proteome profiles in three groups were investigated and might reveal different underlying molecular mechanisms. Results In total, we identified 1745 phosphoproteins with 2724 phosphopeptides and 4594 phosphorylation sites in three groups. Among these phosphoproteins, 80 phosphoproteins were dysregulated in PVTT/Pan group, 51 phosphoproteins were dysregulated in HCC/Pan group, and 10 phosphoproteins were dysregulated in PVTT/HCC group. Furthermore, the phosphorylation of 4E-BP1 was elevated in HCC tissues and PVTT tissues in comparison with surrounding non-cancerous tissues, and the elevated fold change of phosphorylation level was higher than that in expression level of 4E-BP1. The further IHC analysis in acohort of 20 HCC tissues showed that the phosphorylation of 4E-BP1 on Thr46 might be closely related to HCC prognosis. Conclusion The high phosphorylation level of 4E-BP1Thr46 might serve as a biomarker for the diagnosis of early recurrence and metastasis of HCC.
Collapse
Affiliation(s)
- Xincong Lin
- The First Affiliated Hospital of Fujian Medical University, Fuzhou 350007, People's Republic of China.,The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou 350025, People's Republic of China
| | - Yao Huang
- The First Affiliated Hospital of Fujian Medical University, Fuzhou 350007, People's Republic of China.,The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou 350025, People's Republic of China
| | - Ying Sun
- The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou 350025, People's Republic of China
| | - Xionghong Tan
- The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou 350025, People's Republic of China
| | - Jiahe Ouyang
- The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou 350025, People's Republic of China
| | - Bixing Zhao
- The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou 350025, People's Republic of China
| | - Yingchao Wang
- The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou 350025, People's Republic of China
| | - Xiaohua Xing
- The First Affiliated Hospital of Fujian Medical University, Fuzhou 350007, People's Republic of China.,The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou 350025, People's Republic of China
| | - Jingfeng Liu
- The First Affiliated Hospital of Fujian Medical University, Fuzhou 350007, People's Republic of China.,The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou 350025, People's Republic of China
| |
Collapse
|
27
|
O'Shaughnessy EC, Stone OJ, LaFosse PK, Azoitei ML, Tsygankov D, Heddleston JM, Legant WR, Wittchen ES, Burridge K, Elston TC, Betzig E, Chew TL, Adalsteinsson D, Hahn KM. Software for lattice light-sheet imaging of FRET biosensors, illustrated with a new Rap1 biosensor. J Cell Biol 2019; 218:3153-3160. [PMID: 31444239 PMCID: PMC6719445 DOI: 10.1083/jcb.201903019] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 06/28/2019] [Accepted: 07/25/2019] [Indexed: 11/22/2022] Open
Abstract
O’Shaughnessy et al. present new software called ImageTank to process lattice light-sheet images of FRET biosensors. ImageTank efficiently handles large 3D datasets and includes tools for visualization and analysis. Its capabilities are demonstrated using a new Rap1 biosensor in motile cells. Lattice light-sheet microscopy (LLSM) is valuable for its combination of reduced photobleaching and outstanding spatiotemporal resolution in 3D. Using LLSM to image biosensors in living cells could provide unprecedented visualization of rapid, localized changes in protein conformation or posttranslational modification. However, computational manipulations required for biosensor imaging with LLSM are challenging for many software packages. The calculations require processing large amounts of data even for simple changes such as reorientation of cell renderings or testing the effects of user-selectable settings, and lattice imaging poses unique challenges in thresholding and ratio imaging. We describe here a new software package, named ImageTank, that is specifically designed for practical imaging of biosensors using LLSM. To demonstrate its capabilities, we use a new biosensor to study the rapid 3D dynamics of the small GTPase Rap1 in vesicles and cell protrusions.
Collapse
Affiliation(s)
- Ellen C O'Shaughnessy
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Orrin J Stone
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Paul K LaFosse
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Mihai L Azoitei
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Denis Tsygankov
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC.,Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA
| | - John M Heddleston
- Advanced Imaging Center, Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA
| | - Wesley R Legant
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA
| | - Erika S Wittchen
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Keith Burridge
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Timothy C Elston
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Eric Betzig
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA
| | - Teng-Leong Chew
- Advanced Imaging Center, Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA
| | - David Adalsteinsson
- Department of Mathematics, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Klaus M Hahn
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| |
Collapse
|
28
|
Rap1 Negatively Regulates the Hippo Pathway to Polarize Directional Protrusions in Collective Cell Migration. Cell Rep 2019; 22:2160-2175. [PMID: 29466741 DOI: 10.1016/j.celrep.2018.01.080] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 12/12/2017] [Accepted: 01/25/2018] [Indexed: 02/08/2023] Open
Abstract
In collective cell migration, directional protrusions orient cells in response to external cues, which requires coordinated polarity among the migrating cohort. However, the molecular mechanism has not been well defined. Drosophila border cells (BCs) migrate collectively and invade via the confined space between nurse cells, offering an in vivo model to examine how group polarity is organized. Here, we show that the front/back polarity of BCs requires Rap1, hyperactivation of which disrupts cluster polarity and induces misoriented protrusions and loss of asymmetry in the actin network. Conversely, hypoactive Rap1 causes fewer protrusions and cluster spinning during migration. A forward genetic screen revealed that downregulation of the Hippo (Hpo) pathway core components hpo or mats enhances the Rap1V12-induced migration defect and misdirected protrusions. Mechanistically, association of Rap1V12 with the kinase domain of Hpo suppresses its activity, which releases Hpo signaling-mediated suppression of F-actin elongation, promoting cellular protrusions in collective cell migration.
Collapse
|
29
|
ANXA2 Tyr23 and FLNA Ser2152 phosphorylation associate with poor prognosis in hepatic carcinoma revealed by quantitative phosphoproteomics analysis. J Proteomics 2019; 200:111-122. [PMID: 30951906 DOI: 10.1016/j.jprot.2019.03.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 03/15/2019] [Accepted: 03/31/2019] [Indexed: 02/06/2023]
Abstract
Hepatoma is one of the most common malignant tumors, and most patients have very poor prognosis. Early prediction and intervention of the hepatoma recurrence/metastasis are the most effective way to improve the patients' clinical outcomes. Here, we used isobaric tags for relative and absolute quantitation (iTRAQ) based quantitative phospho-proteomics approach to identify biomarkers associated with hepatoma recurrence/metastasis in hepatoma cell lines with increasing metastasis ability. In total, 75 phosphorylated peptides corresponding to 60 phosphoproteins were significantly dysregulated and the participated biological processes of these phosphoproteins were tightly associated with tumor metastasis. Further signaling pathway analysis revealed that key signaling pathways which play crucial roles in cancer metastasis have been significantly over activated in the highly metastatic cells. Furthermore, the phosphorylation of FLNASer2152 and ANXA2Tyr23 were validated to be significantly up regulated in the high-metastatic cells comparing with the low-metastatic cells. By further investigation the clinical significance of the phosphorylation of FLNASer2152 and ANXA2Tyr23 in large-scale clinical samples, revealed that the over phosphorylation of FLNASer2152 and ANXA2Tyr23 were associated with poor prognosis and might be potential prognostic biomarkers for the primary hepatoma. When FLNASer2152 combined with ANXA2Tyr23, it had a better prognostic value for both OS and TTR.
Collapse
|
30
|
Le Saux G, Bar-Hanin N, Edri A, Hadad U, Porgador A, Schvartzman M. Nanoscale Mechanosensing of Natural Killer Cells is Revealed by Antigen-Functionalized Nanowires. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1805954. [PMID: 30488552 DOI: 10.1002/adma.201805954] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 11/06/2018] [Indexed: 06/09/2023]
Abstract
Cells sense their environment by transducing mechanical stimuli into biochemical signals. Commonly used tools to study cell mechanosensing provide limited spatial and force resolution. Here, a novel nanowire-based platform for monitoring cell forces is reported. Nanowires are functionalized with ligands for cell immunoreceptors, and they are used to explore the mechanosensitivity of natural killer (NK) cells. In particular, it is found that NK cells apply centripetal forces to nanowires, and that the nanowires stimulate cell contraction. Based on the nanowire deformation, it is calculated that cells apply forces of down to 10 pN, which is the smallest value demonstrated so far by microstructured platforms for cell spreading. Furthermore, the roles of: i) nanowire topography and ii) activating ligands in the cell immune function are studied and it is found that only their combination produces enhanced population of activated NK cells. Thus, a mechanosensing mechanism of NK cells is proposed, by which they integrate biochemical and mechanical stimuli into a decision-making machinery analogous to the AND logic gate, whose output is the immune activation. This work reveals unprecedented mechanical aspects of NK cell immune function and introduces an innovative nanomaterial for studying cellular mechanics with unparalleled spatial and mechanical resolution.
Collapse
Affiliation(s)
- Guillaume Le Saux
- Department of Materials Engineering, Ben-Gurion University of the Negev, Beer Sheva, 84105, Israel
- Ilse Katz Institute for Nanoscale Science & Technology, Ben-Gurion University of the Negev, Beer Sheva, 84105, Israel
| | - Netanel Bar-Hanin
- Department of Materials Engineering, Ben-Gurion University of the Negev, Beer Sheva, 84105, Israel
- Ilse Katz Institute for Nanoscale Science & Technology, Ben-Gurion University of the Negev, Beer Sheva, 84105, Israel
| | - Avishay Edri
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, 84105, Israel
| | - Uzi Hadad
- Ilse Katz Institute for Nanoscale Science & Technology, Ben-Gurion University of the Negev, Beer Sheva, 84105, Israel
| | - Angel Porgador
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, 84105, Israel
| | - Mark Schvartzman
- Department of Materials Engineering, Ben-Gurion University of the Negev, Beer Sheva, 84105, Israel
- Ilse Katz Institute for Nanoscale Science & Technology, Ben-Gurion University of the Negev, Beer Sheva, 84105, Israel
| |
Collapse
|
31
|
Perspectives of RAS and RHEB GTPase Signaling Pathways in Regenerating Brain Neurons. Int J Mol Sci 2018; 19:ijms19124052. [PMID: 30558189 PMCID: PMC6321366 DOI: 10.3390/ijms19124052] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 12/05/2018] [Accepted: 12/13/2018] [Indexed: 12/29/2022] Open
Abstract
Cellular activation of RAS GTPases into the GTP-binding “ON” state is a key switch for regulating brain functions. Molecular protein structural elements of rat sarcoma (RAS) and RAS homolog protein enriched in brain (RHEB) GTPases involved in this switch are discussed including their subcellular membrane localization for triggering specific signaling pathways resulting in regulation of synaptic connectivity, axonal growth, differentiation, migration, cytoskeletal dynamics, neural protection, and apoptosis. A beneficial role of neuronal H-RAS activity is suggested from cellular and animal models of neurodegenerative diseases. Recent experiments on optogenetic regulation offer insights into the spatiotemporal aspects controlling RAS/mitogen activated protein kinase (MAPK) or phosphoinositide-3 kinase (PI3K) pathways. As optogenetic manipulation of cellular signaling in deep brain regions critically requires penetration of light through large distances of absorbing tissue, we discuss magnetic guidance of re-growing axons as a complementary approach. In Parkinson’s disease, dopaminergic neuronal cell bodies degenerate in the substantia nigra. Current human trials of stem cell-derived dopaminergic neurons must take into account the inability of neuronal axons navigating over a large distance from the grafted site into striatal target regions. Grafting dopaminergic precursor neurons directly into the degenerating substantia nigra is discussed as a novel concept aiming to guide axonal growth by activating GTPase signaling through protein-functionalized intracellular magnetic nanoparticles responding to external magnets.
Collapse
|
32
|
The Many Faces of Rap1 GTPase. Int J Mol Sci 2018; 19:ijms19102848. [PMID: 30241315 PMCID: PMC6212855 DOI: 10.3390/ijms19102848] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Revised: 09/16/2018] [Accepted: 09/17/2018] [Indexed: 12/12/2022] Open
Abstract
This review addresses the issue of the numerous roles played by Rap1 GTPase (guanosine triphosphatase) in different cell types, in terms of both physiology and pathology. It is one among a myriad of small G proteins with endogenous GTP-hydrolyzing activity that is considerably stimulated by posttranslational modifications (geranylgeranylation) or guanine nucleotide exchange factors (GEFs), and inhibited by GTPase-activating proteins (GAPs). Rap1 is a ubiquitous protein that plays an essential role in the control of metabolic processes, such as signal transduction from plasma membrane receptors, cytoskeleton rearrangements necessary for cell division, intracellular and substratum adhesion, as well as cell motility, which is needed for extravasation or fusion. We present several examples of how Rap1 affects cells and organs, pointing to possible molecular manipulations that could have application in the therapy of several diseases.
Collapse
|
33
|
Naydenov NG, Joshi S, Feygin A, Saini S, Litovchick L, Ivanov AI. A membrane fusion protein, Ykt6, regulates epithelial cell migration via microRNA-mediated suppression of Junctional Adhesion Molecule A. Cell Cycle 2018; 17:1812-1831. [PMID: 30010460 DOI: 10.1080/15384101.2018.1496755] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Vesicle trafficking regulates epithelial cell migration by remodeling matrix adhesions and delivering signaling molecules to the migrating leading edge. Membrane fusion, which is driven by soluble N-ethylmaleimide-sensitive factor associated receptor (SNARE) proteins, is an essential step of vesicle trafficking. Mammalian SNAREs represent a large group of proteins, but few have been implicated in the regulation of cell migration. Ykt6 is a unique SNARE existing in equilibrium between active membrane-bound and inactive cytoplasmic pools, and mediating vesicle trafficking between different intracellular compartments. The biological functions of this protein remain poorly understood. In the present study, we found that Ykt6 acts as a negative regulator of migration and invasion of human prostate epithelial cells. Furthermore, Ykt6 regulates the integrity of epithelial adherens and tight junctions. The observed anti-migratory activity of Ykt6 is mediated by a unique mechanism involving the expressional upregulation of microRNA 145, which selectively decreases the cellular level of Junctional Adhesion Molecule (JAM) A. This decreased JAM-A expression limits the activity of Rap1 and Rac1 small GTPases, thereby attenuating cell spreading and motility. The described novel functions of Ykt6 could be essential for the regulation of epithelial barriers, epithelial repair, and metastatic dissemination of cancer cells.
Collapse
Affiliation(s)
- Nayden G Naydenov
- a Department of Inflammation and Immunity , Lerner Research Institute of Cleveland Clinic Foundation , Cleveland , OH , USA.,b Department of Human and Molecular Genetics , Virginia Commonwealth University , Richmond , VA , USA
| | - Supriya Joshi
- b Department of Human and Molecular Genetics , Virginia Commonwealth University , Richmond , VA , USA
| | - Alex Feygin
- b Department of Human and Molecular Genetics , Virginia Commonwealth University , Richmond , VA , USA
| | - Siddharth Saini
- c Department of Internal Medicine , Virginia Commonwealth University , Richmond , VA , USA
| | - Larisa Litovchick
- c Department of Internal Medicine , Virginia Commonwealth University , Richmond , VA , USA
| | - Andrei I Ivanov
- a Department of Inflammation and Immunity , Lerner Research Institute of Cleveland Clinic Foundation , Cleveland , OH , USA.,b Department of Human and Molecular Genetics , Virginia Commonwealth University , Richmond , VA , USA
| |
Collapse
|
34
|
Keydar Y, Le Saux G, Pandey A, Avishay E, Bar-Hanin N, Esti T, Bhingardive V, Hadad U, Porgador A, Schvartzman M. Natural killer cells' immune response requires a minimal nanoscale distribution of activating antigens. NANOSCALE 2018; 10:14651-14659. [PMID: 30033475 DOI: 10.1039/c8nr04038a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
NK cells recognize cancer and viral cells by binding their activating receptors to antigens presenting on the membrane of target cells. Although the activation mechanism of NK cells is a subject of extensive research today, the role of the composition and spatial distribution of activating ligands in NK cell cytotoxicity is barely understood. In this work, we engineered a nanochip whose surface was patterned with matrices of antigens for NKG2D activating receptors. These matrices mimicked the spatial order of the surface of antigen presenting cells with molecular resolution. Using this chip, we elucidated the effect of the antigen spatial distribution on the NK cell spreading and immune activation. We found that the spatial distribution of the ligand within the 100 nm length-scale provides the minimal conditions for NKG2D regulated cell spreading. Furthermore, we found that the immune activation of NK cells requires the same minimal spatial distribution of activating ligands. Above this threshold, both spreading and activation plateaued, confirming that these two cell functions work hand in hand. Our study provides an important insight on the spatial mechanism of the cytotoxic activity of NK cells. This insight opens the way to rationally designed antitumor therapies that harness NK cytotoxicity.
Collapse
Affiliation(s)
- Yossi Keydar
- Department of Materials Engineering, Ben Gurion University of the Negev, Beer Sheva 84105, Israel.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Nalbant P, Dehmelt L. Exploratory cell dynamics: a sense of touch for cells? Biol Chem 2018; 399:809-819. [DOI: 10.1515/hsz-2017-0341] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 04/06/2018] [Indexed: 01/28/2023]
Abstract
Abstract
Cells need to process multifaceted external cues to steer their dynamic behavior. To efficiently perform this task, cells implement several exploratory mechanisms to actively sample their environment. In particular, cells can use exploratory actin-based cell protrusions and contractions to engage and squeeze the environment and to actively probe its chemical and mechanical properties. Multiple excitable signal networks were identified that can generate local activity pulses to control these exploratory processes. Such excitable signal networks offer particularly efficient mechanisms to process chemical or mechanical signals to steer dynamic cell behavior, such as directional migration, tissue morphogenesis and cell fate decisions.
Collapse
Affiliation(s)
- Perihan Nalbant
- Department of Molecular Cell Biology , Center for Medical Biotechnology , University of Duisburg-Essen, Universitätsstrasse 2 , D-45141 Essen , Germany
| | - Leif Dehmelt
- Department of Systemic Cell Biology , Max Planck Institute of Molecular Physiology, and Dortmund University of Technology, Faculty of Chemistry and Chemical Biology , Otto-Hahn-Str. 4a , D-44227 Dortmund , Germany
| |
Collapse
|
36
|
Abstract
The formation of correct synaptic structures and neuronal connections is paramount for normal brain development and a functioning adult brain. The integrin family of cell adhesion receptors and their ligands play essential roles in the control of several processes regulating neuronal connectivity - including neurite outgrowth, the formation and maintenance of synapses, and synaptic plasticity - that are affected in neurodevelopmental disorders, such as autism spectrum disorders (ASDs) and schizophrenia. Many ASD- and schizophrenia-associated genes are linked to alterations in the genetic code of integrins and associated signalling pathways. In non-neuronal cells, crosstalk between integrin-mediated adhesions and the actin cytoskeleton, and the regulation of integrin activity (affinity for extracellular ligands) are widely studied in healthy and pathological settings. In contrast, the roles of integrin-linked pathways in the central nervous system remains less well defined. In this Review, we will provide an overview of the known pathways that are regulated by integrin-ECM interaction in developing neurons and in adult brain. We will also describe recent advances in the identification of mechanisms that regulate integrin activity in neurons, and highlight the interesting emerging links between integrins and neurodevelopment.
Collapse
Affiliation(s)
- Johanna Lilja
- Turku Centre for Biotechnology, University of Turku, FIN-20520 Turku, Finland
| | - Johanna Ivaska
- Turku Centre for Biotechnology, University of Turku, FIN-20520 Turku, Finland .,Department of Biochemistry, University of Turku, FIN-20500 Turku, Finland
| |
Collapse
|
37
|
Hilfenhaus G, Nguyen DP, Freshman J, Prajapati D, Ma F, Song D, Ziyad S, Cuadrado M, Pellegrini M, Bustelo XR, Iruela-Arispe ML. Vav3-induced cytoskeletal dynamics contribute to heterotypic properties of endothelial barriers. J Cell Biol 2018; 217:2813-2830. [PMID: 29858212 PMCID: PMC6080943 DOI: 10.1083/jcb.201706041] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 04/12/2018] [Accepted: 05/08/2018] [Indexed: 12/26/2022] Open
Abstract
Through multiple cell-cell and cell-matrix interactions, epithelial and endothelial sheets form tight barriers. Modulators of the cytoskeleton contribute to barrier stability and act as rheostats of vascular permeability. In this study, we sought to identify cytoskeletal regulators that underlie barrier diversity across vessels. To achieve this, we correlated functional and structural barrier features to gene expression of endothelial cells (ECs) derived from different vascular beds. Within a subset of identified candidates, we found that the guanosine nucleotide exchange factor Vav3 was exclusively expressed by microvascular ECs and was closely associated with a high-resistance barrier phenotype. Ectopic expression of Vav3 in large artery and brain ECs significantly enhanced barrier resistance and cortical rearrangement of the actin cytoskeleton. Mechanistically, we found that the barrier effect of Vav3 is dependent on its Dbl homology domain and downstream activation of Rap1. Importantly, inactivation of Vav3 in vivo resulted in increased vascular leakage, highlighting its function as a key regulator of barrier stability.
Collapse
Affiliation(s)
- Georg Hilfenhaus
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA
| | - Dai Phuong Nguyen
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA
| | - Jonathan Freshman
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA
| | - Divya Prajapati
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA
| | - Feiyang Ma
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA
| | - Dana Song
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA
| | - Safiyyah Ziyad
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA
| | - Myriam Cuadrado
- Centro de Investigación del Cáncer, Instituto de Biología Molecular y Celular del Cáncer, and Centro de Investigación Biomédica en Red de Cáncer, Consejo Superior de Investigaciones Científicas, and University of Salamanca, Campus Unamuno, Salamanca, Spain
| | - Matteo Pellegrini
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA.,Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA
| | - Xosé R Bustelo
- Centro de Investigación del Cáncer, Instituto de Biología Molecular y Celular del Cáncer, and Centro de Investigación Biomédica en Red de Cáncer, Consejo Superior de Investigaciones Científicas, and University of Salamanca, Campus Unamuno, Salamanca, Spain
| | - M Luisa Iruela-Arispe
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA .,Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA
| |
Collapse
|
38
|
Shah S, Brock EJ, Ji K, Mattingly RR. Ras and Rap1: A tale of two GTPases. Semin Cancer Biol 2018; 54:29-39. [PMID: 29621614 DOI: 10.1016/j.semcancer.2018.03.005] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 03/16/2018] [Accepted: 03/29/2018] [Indexed: 02/07/2023]
Abstract
Ras oncoproteins play pivotal roles in both the development and maintenance of many tumor types. Unfortunately, these proteins are difficult to directly target using traditional pharmacological strategies, in part due to their lack of obvious binding pockets or allosteric sites. This obstacle has driven a considerable amount of research into pursuing alternative ways to effectively inhibit Ras, examples of which include inducing mislocalization to prevent Ras maturation and inactivating downstream proteins in Ras-driven signaling pathways. Ras proteins are archetypes of a superfamily of small GTPases that play specific roles in the regulation of many cellular processes, including vesicle trafficking, nuclear transport, cytoskeletal rearrangement, and cell cycle progression. Several other superfamily members have also been linked to the control of normal and cancer cell growth and survival. For example, Rap1 has high sequence similarity to Ras, has overlapping binding partners, and has been demonstrated to both oppose and mimic Ras-driven cancer phenotypes. Rap1 plays an important role in cell adhesion and integrin function in a variety of cell types. Mechanistically, Ras and Rap1 cooperate to initiate and sustain ERK signaling, which is activated in many malignancies and is the target of successful therapeutics. Here we review the role activated Rap1 in ERK signaling and other downstream pathways to promote invasion and cell migration and metastasis in various cancer types.
Collapse
Affiliation(s)
- Seema Shah
- Program in Cancer Biology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Ethan J Brock
- Program in Cancer Biology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Kyungmin Ji
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Raymond R Mattingly
- Program in Cancer Biology, Wayne State University School of Medicine, Detroit, MI 48201, USA; Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI 48201, USA.
| |
Collapse
|
39
|
Robichaux WG, Cheng X. Intracellular cAMP Sensor EPAC: Physiology, Pathophysiology, and Therapeutics Development. Physiol Rev 2018; 98:919-1053. [PMID: 29537337 PMCID: PMC6050347 DOI: 10.1152/physrev.00025.2017] [Citation(s) in RCA: 138] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 09/05/2017] [Accepted: 09/06/2017] [Indexed: 12/13/2022] Open
Abstract
This review focuses on one family of the known cAMP receptors, the exchange proteins directly activated by cAMP (EPACs), also known as the cAMP-regulated guanine nucleotide exchange factors (cAMP-GEFs). Although EPAC proteins are fairly new additions to the growing list of cAMP effectors, and relatively "young" in the cAMP discovery timeline, the significance of an EPAC presence in different cell systems is extraordinary. The study of EPACs has considerably expanded the diversity and adaptive nature of cAMP signaling associated with numerous physiological and pathophysiological responses. This review comprehensively covers EPAC protein functions at the molecular, cellular, physiological, and pathophysiological levels; and in turn, the applications of employing EPAC-based biosensors as detection tools for dissecting cAMP signaling and the implications for targeting EPAC proteins for therapeutic development are also discussed.
Collapse
Affiliation(s)
- William G Robichaux
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center , Houston, Texas
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center , Houston, Texas
| |
Collapse
|
40
|
Kovacs-Kasa A, Kim KM, Cherian-Shaw M, Black SM, Fulton DJ, Verin AD. Extracellular adenosine-induced Rac1 activation in pulmonary endothelium: Molecular mechanisms and barrier-protective role. J Cell Physiol 2018; 233:5736-5746. [PMID: 29168172 DOI: 10.1002/jcp.26281] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 11/14/2017] [Indexed: 12/12/2022]
Abstract
We have previously shown that Gs-coupled adenosine receptors (A2a) are primarily involved in adenosine-induced human pulmonary artery endothelial cell (HPAEC) barrier enhancement. However, the downstream events that mediate the strengthening of the endothelial cell (EC) barrier via adenosine signaling are largely unknown. In the current study, we tested the overall hypothesis that adenosine-induced Rac1 activation and EC barrier enhancement is mediated by Gs-dependent stimulation of cAMP-dependent Epac1-mediated signaling cascades. Adenoviral transduction of HPAEC with constitutively-active (C/A) Rac1 (V12Rac1) significantly increases transendothelial electrical resistance (TER) reflecting an enhancement of the EC barrier. Conversely, expression of an inactive Rac1 mutant (N17Rac1) decreases TER reflecting a compromised EC barrier. The adenosine-induced increase in TER was accompanied by activation of Rac1, decrease in contractility (MLC dephosphorylation), but not Rho inhibition. Conversely, inhibition of Rac1 activity attenuates adenosine-induced increase in TER. We next examined the role of cAMP-activated Epac1 and its putative downstream targets Rac1, Vav2, Rap1, and Tiam1. Depletion of Epac1 attenuated the adenosine-induced Rac1 activation and the increase in TER. Furthermore, silencing of Rac1 specific guanine nucleotide exchange factors (GEFs), Vav2 and Rap1a expression significantly attenuated adenosine-induced increases in TER and activation of Rac1. Depletion of Rap1b only modestly impacted adenosine-induced increases in TER and Tiam1 depletion had no effect on adenosine-induced Rac1 activation and TER. Together these data strongly suggest that Rac1 activity is required for adenosine-induced EC barrier enhancement and that the activation of Rac1 and ability to strengthen the EC barrier depends, at least in part, on cAMP-dependent Epac1/Vav2/Rap1-mediated signaling.
Collapse
Affiliation(s)
- Anita Kovacs-Kasa
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, Georgia
| | - Kyung Mi Kim
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, Georgia
| | - Mary Cherian-Shaw
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, Georgia
| | - Stephen M Black
- Center for Lung Vascular Pathobiology, University of Arizona, Phoenix, Arizona
| | - David J Fulton
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, Georgia
| | - Alexander D Verin
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, Georgia
| |
Collapse
|
41
|
Rho SS, Ando K, Fukuhara S. Dynamic Regulation of Vascular Permeability by Vascular Endothelial Cadherin-Mediated Endothelial Cell-Cell Junctions. J NIPPON MED SCH 2018; 84:148-159. [PMID: 28978894 DOI: 10.1272/jnms.84.148] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Endothelial cells lining blood vessels regulate vascular barrier function, which controls the passage of plasma proteins and circulating cells across the endothelium. In most normal adult tissues, endothelial cells preserve basal vascular permeability at a low level, while they increase permeability in response to inflammation. Therefore, vascular permeability is tightly controlled by a number of extracellular stimuli and mediators to maintain tissue homeostasis. Accordingly, impaired regulation of endothelial permeability causes various diseases, including chronic inflammation, asthma, edema, sepsis, acute respiratory distress syndrome, anaphylaxis, tumor angiogenesis, and diabetic retinopathy. Vascular endothelial (VE)-cadherin, a member of the classical cadherin superfamily, is a component of cell-to-cell adherens junctions in endothelial cells and plays an important role in regulating vascular permeability. VE-cadherin mediates intercellular adhesion through trans-interactions formed by its extracellular domain, while its cytoplasmic domain is anchored to the actin cytoskeleton via α- and β-catenins, leading to stabilization of VE-cadherin at cell-cell junctions. VE-cadherin-mediated cell adhesions are dynamically, but tightly, controlled by mechanisms that involve protein phosphorylation and reorganization of the actomyosin cytoskeleton. Phosphorylation of VE-cadherin, and its associated-catenins, results in dissociation of the VE-cadherin/catenin complex and internalization of VE-cadherin, leading to increased vascular permeability. Furthermore, reorganization of the actomyosin cytoskeleton by Rap1, a small GTPase that belongs to the Ras subfamily, and Rho family small GTPases, regulates VE-cadherin-mediated cell adhesions to control vascular permeability. In this review, we describe recent progress in understanding the signaling mechanisms that enable dynamic regulation of VE-cadherin adhesions and vascular permeability. In addition, we discuss the possibility of novel therapeutic approaches targeting the signaling pathways controlling VE-cadherin-mediated cell adhesion in diseases associated with vascular hyper-permeability.
Collapse
Affiliation(s)
- Seung-Sik Rho
- Department of Molecular Pathophysiology, Institute of Advanced Medical Sciences, Nippon Medical School Musashi Kosugi Hospital
| | - Koji Ando
- Department of Cell Biology, National Cerebral and Cardiovascular Center Research Institute
| | - Shigetomo Fukuhara
- Department of Molecular Pathophysiology, Institute of Advanced Medical Sciences, Nippon Medical School Musashi Kosugi Hospital
| |
Collapse
|
42
|
Heo K, Nahm M, Lee MJ, Kim YE, Ki CS, Kim SH, Lee S. The Rap activator Gef26 regulates synaptic growth and neuronal survival via inhibition of BMP signaling. Mol Brain 2017; 10:62. [PMID: 29282074 PMCID: PMC5745669 DOI: 10.1186/s13041-017-0342-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 12/12/2017] [Indexed: 12/24/2022] Open
Abstract
In Drosophila, precise regulation of BMP signaling is essential for normal synaptic growth at the larval neuromuscular junction (NMJ) and neuronal survival in the adult brain. However, the molecular mechanisms underlying fine-tuning of BMP signaling in neurons remain poorly understood. We show that loss of the Drosophila PDZ guanine nucleotide exchange factor Gef26 significantly increases synaptic growth at the NMJ and enhances BMP signaling in motor neurons. We further show that Gef26 functions upstream of Rap1 in motor neurons to restrain synaptic growth. Synaptic overgrowth in gef26 or rap1 mutants requires BMP signaling, indicating that Gef26 and Rap1 regulate synaptic growth via inhibition of BMP signaling. We also show that Gef26 is involved in the endocytic downregulation of surface expression of the BMP receptors thickveins (Tkv) and wishful thinking (Wit). Finally, we demonstrate that loss of Gef26 also induces progressive brain neurodegeneration through Rap1- and BMP signaling-dependent mechanisms. Taken together, these results suggest that the Gef26-Rap1 signaling pathway regulates both synaptic growth and neuronal survival by controlling BMP signaling.
Collapse
Affiliation(s)
- Keunjung Heo
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, 08826, South Korea.,Department of Cell & Developmental Biology, Dental Research Institute, Seoul National University, Seoul, 03080, South Korea
| | - Minyeop Nahm
- Department of Neurology, Hanyang University College of Medicine, Seoul, 04763, South Korea
| | - Min-Jung Lee
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, 08826, South Korea.,Department of Cell & Developmental Biology, Dental Research Institute, Seoul National University, Seoul, 03080, South Korea
| | - Young-Eun Kim
- Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, 06351, South Korea
| | - Chang-Seok Ki
- Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, 06351, South Korea
| | - Seung Hyun Kim
- Department of Neurology, Hanyang University College of Medicine, Seoul, 04763, South Korea
| | - Seungbok Lee
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, 08826, South Korea.
| |
Collapse
|
43
|
Lo Sardo F, Muti P, Blandino G, Strano S. Melatonin and Hippo Pathway: Is There Existing Cross-Talk? Int J Mol Sci 2017; 18:ijms18091913. [PMID: 28878191 PMCID: PMC5618562 DOI: 10.3390/ijms18091913] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 08/30/2017] [Accepted: 09/01/2017] [Indexed: 12/16/2022] Open
Abstract
Melatonin is an indolic hormone that regulates a plethora of functions ranging from the regulation of circadian rhythms and antioxidant properties to the induction and maintenance of tumor suppressor pathways. It binds to specific receptors as well as to some cytosolic proteins, leading to several cellular signaling cascades. Recently, the involvement of melatonin in cancer insurgence and progression has clearly been demonstrated. In this review, we will first describe the structure and functions of melatonin and its receptors, and then discuss both molecular and epidemiological evidence on melatonin anticancer effects. Finally, we will shed light on potential cross-talk between melatonin signaling and the Hippo signaling pathway, along with the possible implications for cancer therapy.
Collapse
Affiliation(s)
- Federica Lo Sardo
- Oncogenomic and Epigenetic Unit, Molecular Chemoprevention Group, Department of Research, Diagnosis and Innovative Technologies, Translational Research Area, Regina Elena National Cancer Institute, via Elio Chianesi 53, 00144 Rome, Italy.
| | - Paola Muti
- Department of Oncology, Juravinski Cancer Center, McMaster University, Hamilton, ON L8S 4L8, Canada.
| | - Giovanni Blandino
- Oncogenomic and Epigenetic Unit, Molecular Chemoprevention Group, Department of Research, Diagnosis and Innovative Technologies, Translational Research Area, Regina Elena National Cancer Institute, via Elio Chianesi 53, 00144 Rome, Italy.
| | - Sabrina Strano
- Oncogenomic and Epigenetic Unit, Molecular Chemoprevention Group, Department of Research, Diagnosis and Innovative Technologies, Translational Research Area, Regina Elena National Cancer Institute, via Elio Chianesi 53, 00144 Rome, Italy.
| |
Collapse
|
44
|
Hilbi H, Kortholt A. Role of the small GTPase Rap1 in signal transduction, cell dynamics and bacterial infection. Small GTPases 2017. [PMID: 28632994 DOI: 10.1080/21541248.2017.1331721] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
Rap1 belongs to the Ras family of small GTPases, which are involved in a multitude of cellular signal transduction pathways and have extensively been linked to cancer biogenesis and metastasis. The small GTPase is activated in response to various extracellular and intracellular cues. Rap1 has conserved functions in Dictyostelium discoideum amoeba and mammalian cells, which are important for cell polarity, substrate and cell-cell adhesion and other processes that involve the regulation of cytoskeletal dynamics. Moreover, our recent study has shown that Rap1 is required for the formation of the replication-permissive vacuole of an intracellular bacterial pathogen. Here we review the function and regulation of Rap1 in these distinct processes, and we discuss the underlying signal transduction pathways.
Collapse
Affiliation(s)
- Hubert Hilbi
- a Institute of Medical Microbiology, University of Zürich , Zürich , Switzerland
| | - Arjan Kortholt
- b Department of Cell Biochemistry, University of Groningen , Groningen , The Netherlands
| |
Collapse
|
45
|
Optogenetic control of the Dab1 signaling pathway. Sci Rep 2017; 7:43760. [PMID: 28272509 PMCID: PMC5363252 DOI: 10.1038/srep43760] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 01/26/2017] [Indexed: 12/31/2022] Open
Abstract
The Reelin-Dab1 signaling pathway regulates development of the mammalian brain, including neuron migrations in various brain regions, as well as learning and memory in adults. Extracellular Reelin binds to cell surface receptors and activates phosphorylation of the intracellular Dab1 protein. Dab1 is required for most effects of Reelin, but Dab1-independent pathways may contribute. Here we developed a single-component, photoactivatable Dab1 (opto-Dab1) by using the blue light-sensitive dimerization/oligomerization property of A. thaliana Cryptochrome 2 (Cry2). Opto-Dab1 can activate downstream signals rapidly, locally, and reversibly upon blue light illumination. The high spatiotemporal resolution of the opto-Dab1 probe also allows us to control membrane protrusion, retraction and ruffling by local illumination in both COS7 cells and in primary neurons. This shows that Dab1 activation is sufficient to orient cell movement in the absence of other signals. Opto-Dab1 may be useful to study the biological functions of the Reelin-Dab1 signaling pathway both in vitro and in vivo.
Collapse
|
46
|
SHANK proteins limit integrin activation by directly interacting with Rap1 and R-Ras. Nat Cell Biol 2017; 19:292-305. [PMID: 28263956 PMCID: PMC5386136 DOI: 10.1038/ncb3487] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 02/06/2017] [Indexed: 12/17/2022]
Abstract
SHANK3, a synaptic scaffold protein and actin regulator, is widely
expressed outside of the central nervous system with predominantly unknown
function. Solving the structure of the SHANK3 N-terminal region revealed that
the SPN-domain is an unexpected Ras-association domain with high affinity for
GTP-bound Ras and Rap G-proteins. The role of Rap1 in integrin activation is
well established but the mechanisms to antagonize it remain largely unknown.
Here, we show that SHANK1 and SHANK3 act as integrin activation inhibitors by
sequestering active Rap1 and R-Ras via the SPN-domain and thus limiting their
bioavailability at the plasma membrane. Consistently, SHANK3
silencing triggers increased plasma membrane Rap1 activity, cell spreading,
migration and invasion. Autism-related mutations within the SHANK3 SPN-domain
(R12C and L68P) disrupt G-protein interaction and fail to counteract integrin
activation along the Rap1/RIAM/talin axis in cancer cells and neurons.
Altogether, we establish SHANKs as critical regulators of G-protein signalling
and integrin-dependent processes.
Collapse
|
47
|
Kowluru A. Tiam1/Vav2-Rac1 axis: A tug-of-war between islet function and dysfunction. Biochem Pharmacol 2017; 132:9-17. [PMID: 28202288 DOI: 10.1016/j.bcp.2017.02.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 02/07/2017] [Indexed: 10/20/2022]
Abstract
Glucose-stimulated insulin secretion [GSIS] from the islet β-cell involves a well-orchestrated interplay between metabolic and cationic events. It is well established that intracellular generation of adenine and guanine nucleotide triphosphates [e.g., ATP and GTP] represents one of the requisite signaling steps in GSIS. The small molecular mass GTP-binding proteins [G-proteins; e.g., Rac1 and Cdc42] have been shown to regulate islet β-cell function including actin cytoskeletal remodeling and fusion of insulin granules with the plasma membrane for GSIS to occur. In this context, several regulatory factors for these G-proteins have been identified in the pancreatic β-cell; these include guanine nucleotide exchange factors [GEFs] and guanine nucleotide dissociation inhibitors [GDI]. Recent pharmacological and molecular biological evidence identified Tiam1 and Vav2 as GEFs for Rac1 in promoting physiological insulin secretion. Paradoxically, emerging evidence in multiple cell types, including the islet β-cell, suggests key roles for Rac1 in the onset of cellular dysfunction under conditions of metabolic stress and diabetes. Furthermore, functional inactivation of either Tiam1 or Vav2 appears to attenuate sustained activation of Rac1 and its downstream signaling events [activation of stress kinases] under conditions of metabolic stress. Together, these findings suggest both "friendly" and "non-friendly" roles for Tiam1/Vav2-Rac1 signaling axis in islet β-cell in health and diabetes. Our current understanding of the field and the knowledge gaps that exist in this area of islet biology are heighted herein. Furthermore, potential caveats in the specificity and selectivity of pharmacological inhibitors that are available currently are discussed in this Commentary.
Collapse
Affiliation(s)
- Anjaneyulu Kowluru
- Beta-Cell Biochemistry Laboratory, John D. Dingell VA Medical Center, and Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI 48201, USA.
| |
Collapse
|
48
|
Abstract
Ras-associated protein-1 (Rap1), a small GTPase in the Ras-related protein family, is an important regulator of basic cellular functions (e.g., formation and control of cell adhesions and junctions), cellular migration, and polarization. Through its interaction with other proteins, Rap1 plays many roles during cell invasion and metastasis in different cancers. The basic function of Rap1 is straightforward; it acts as a switch during cellular signaling transduction and regulated by its binding to either guanosine triphosphate (GTP) or guanosine diphosphate (GDP). However, its remarkably diverse function is rendered by its interplay with a large number of distinct Rap guanine nucleotide exchange factors and Rap GTPase activating proteins. This review summarizes the mechanisms by which Rap1 signaling can regulate cell invasion and metastasis, focusing on its roles in integrin and cadherin regulation, Rho GTPase control, and matrix metalloproteinase expression.
Collapse
Affiliation(s)
- Yi-Lei Zhang
- Key Laboratory of Molecular Biophysics of Ministry of Education, School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Ruo-Chen Wang
- Key Laboratory of Molecular Biophysics of Ministry of Education, School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Ken Cheng
- Sun Yat-sen University, Guangzhou 510275, China
| | - Brian Z Ring
- Key Laboratory of Molecular Biophysics of Ministry of Education, School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Li Su
- Key Laboratory of Molecular Biophysics of Ministry of Education, School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China.,Research Institute of Huazhong University of Science and Technology in Shenzhen, Shenzhen 518063, China
| |
Collapse
|
49
|
Small GTPases and their guanine-nucleotide exchange factors and GTPase-activating proteins in neutrophil recruitment. Curr Opin Hematol 2016; 23:44-54. [PMID: 26619317 DOI: 10.1097/moh.0000000000000199] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE OF REVIEW The review describes the roles of Rho- and Rap-guanosine triphosphatases (GTPases) and of their activators, guanine-nucleotide exchange factors (GEFs), and inhibitors, GTPase activating proteins (GAPs), in neutrophil recruitment from the blood stream into inflamed tissues, with a focus on recently identified roles in neutrophils, endothelial cells, and platelets. RECENT FINDINGS Recent studies have identified important roles of Rho- and Rap-GTPases, and of their GEFs and GAPs, in the neutrophil recruitment cascade. These proteins control the upregulation and/or activation of adhesion molecules on the surface of neutrophils, endothelial cells, and platelets, and they alter cell/cell adhesion in the vascular endothelium. This enables the capture of neutrophils from the blood stream, their migration along and through the vessel wall, and their passage into the inflamed tissue. In particular, it has recently become clear that P-Rex and Vav family Rac-GEFs in platelets are crucial for neutrophil recruitment. SUMMARY These recent findings have contributed greatly to our understanding of the signalling pathways that control neutrophil recruitment to sites of inflammation and have opened up new avenues of research in this field.
Collapse
|
50
|
Hormetic and anti-inflammatory properties of oxidized phospholipids. Mol Aspects Med 2016; 49:78-90. [DOI: 10.1016/j.mam.2016.02.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 02/04/2016] [Accepted: 02/04/2016] [Indexed: 12/15/2022]
|