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Kjer-Hansen P, Phan TG, Weatheritt RJ. Protein isoform-centric therapeutics: expanding targets and increasing specificity. Nat Rev Drug Discov 2024; 23:759-779. [PMID: 39232238 DOI: 10.1038/s41573-024-01025-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/31/2024] [Indexed: 09/06/2024]
Abstract
Most protein-coding genes produce multiple protein isoforms; however, these isoforms are commonly neglected in drug discovery. The expression of protein isoforms can be specific to a disease, tissue and/or developmental stage, and this specific expression can be harnessed to achieve greater drug specificity than pan-targeting of all gene products and to enable improved treatments for diseases caused by aberrant protein isoform production. In recent years, several protein isoform-centric therapeutics have been developed. Here, we collate these studies and clinical trials to highlight three distinct but overlapping modes of action for protein isoform-centric drugs: isoform switching, isoform introduction or depletion, and modulation of isoform activity. In addition, we discuss how protein isoforms can be used clinically as targets for cell type-specific drug delivery and immunotherapy, diagnostic biomarkers and sources of cancer neoantigens. Collectively, we emphasize the value of a focus on isoforms as a route to discovering drugs with greater specificity and fewer adverse effects. This approach could enable the targeting of proteins for which pan-inhibition of all isoforms is toxic and poorly tolerated.
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Affiliation(s)
- Peter Kjer-Hansen
- EMBL Australia, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.
- St. Vincent's Healthcare Clinical Campus, School of Clinical Medicine, Faculty of Medicine and Health, UNSW Sydney, Darlinghurst, New South Wales, Australia.
| | - Tri Giang Phan
- St. Vincent's Healthcare Clinical Campus, School of Clinical Medicine, Faculty of Medicine and Health, UNSW Sydney, Darlinghurst, New South Wales, Australia
- Precision Immunology Program, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - Robert J Weatheritt
- EMBL Australia, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia.
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2
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Arce FT, Younger S, Gaber AA, Mascarenhas JB, Rodriguez M, Dudek SM, Garcia JGN. Lamellipodia dynamics and microrheology in endothelial cell paracellular gap closure. Biophys J 2023; 122:4730-4747. [PMID: 37978804 PMCID: PMC10754712 DOI: 10.1016/j.bpj.2023.11.016] [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: 01/15/2023] [Revised: 05/06/2023] [Accepted: 11/16/2023] [Indexed: 11/19/2023] Open
Abstract
Vascular endothelial cells (ECs) form a semipermeable barrier separating vascular contents from the interstitium, thereby regulating the movement of water and molecular solutes across small intercellular gaps, which are continuously forming and closing. Under inflammatory conditions, however, larger EC gaps form resulting in increased vascular leakiness to circulating fluid, proteins, and cells, which results in organ edema and dysfunction responsible for key pathophysiologic findings in numerous inflammatory disorders. In this study, we extend our earlier work examining the biophysical properties of EC gap formation and now address the role of lamellipodia, thin sheet-like membrane projections from the leading edge, in modulating EC spatial-specific contractile properties and gap closure. Micropillars, fabricated by soft lithography, were utilized to form reproducible paracellular gaps in human lung ECs. Using time-lapse imaging via optical microscopy, rates of EC gap closure and motility were measured with and without EC stimulation with the barrier-enhancing sphingolipid, sphingosine-1-phosphate. Peripheral ruffle formation was ubiquitous during gap closure. Kymographs were generated to quantitatively compare the lamellipodia dynamics of sphingosine-1-phosphate-stimulated and -unstimulated ECs. Utilizing atomic force microscopy, we characterized the viscoelastic behavior of EC lamellipodia. Our results indicate decreased stiffness and increased liquid-like behavior of expanding lamellipodia compared with regions away from the cellular edge (lamella and cell body) during EC gap closure, results in sync with the rapid kinetics of protrusion/retraction motion. We hypothesize this dissipative EC behavior during gap closure is linked to actomyosin cytoskeletal rearrangement and decreased cross-linking during lamellipodia expansion. In summary, these studies of the kinetic and mechanical properties of EC lamellipodia and ruffles at gap boundaries yield insights into the mechanisms of vascular barrier restoration and potentially a model system for examining the druggability of lamellipodial protein targets to enhance vascular barrier integrity.
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Affiliation(s)
- Fernando Teran Arce
- The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, University of Florida, Jupiter, Florida.
| | - Scott Younger
- Department of Biomedical Engineering, University of Arizona, Tucson, Arizona
| | - Amir A Gaber
- Department of Medicine, University of Arizona, Tucson, Arizona
| | | | - Marisela Rodriguez
- The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, University of Florida, Jupiter, Florida; Department of Medicine, University of Arizona, Tucson, Arizona
| | - Steven M Dudek
- Department of Medicine, The University of Illinois at Chicago, Chicago, Illinois
| | - Joe G N Garcia
- The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, University of Florida, Jupiter, Florida.
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3
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Kjer-Hansen P, Weatheritt RJ. The function of alternative splicing in the proteome: rewiring protein interactomes to put old functions into new contexts. Nat Struct Mol Biol 2023; 30:1844-1856. [PMID: 38036695 DOI: 10.1038/s41594-023-01155-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 10/17/2023] [Indexed: 12/02/2023]
Abstract
Alternative splicing affects more than 95% of multi-exon genes in the human genome. These changes affect the proteome in a myriad of ways. Here, we review our understanding of the breadth of these changes from their effect on protein structure to their influence on interactions. These changes encompass effects on nucleic acid binding in the nucleus to protein-carbohydrate interactions in the extracellular milieu, altering interactions involving all major classes of biological molecules. Protein isoforms have profound influences on cellular and tissue physiology, for example, by shaping neuronal connections, enhancing insulin secretion by pancreatic beta cells and allowing for alternative viral defense strategies in stem cells. More broadly, alternative splicing enables repurposing proteins from one context to another and thereby contributes to both the evolution of new traits as well as the creation of disease-specific interactomes that drive pathological phenotypes. In this Review, we highlight this universal character of alternative splicing as a central regulator of protein function with implications for almost every biological process.
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Affiliation(s)
- Peter Kjer-Hansen
- EMBL Australia, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.
- St. Vincent Clinical School, University of New South Wales, Darlinghurst, New South Wales, Australia.
| | - Robert J Weatheritt
- EMBL Australia, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia.
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4
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Belvitch P, Casanova N, Sun X, Camp SM, Sammani S, Brown ME, Mascarhenas J, Lynn H, Adyshev D, Siegler J, Desai A, Seyed-Saadat L, Rizzo A, Bime C, Shekhawat GS, Dravid VP, Reilly JP, Jones TK, Feng R, Letsiou E, Meyer NJ, Ellis N, Garcia JGN, Dudek SM. A cortactin CTTN coding SNP contributes to lung vascular permeability and inflammatory disease severity in African descent subjects. Transl Res 2022; 244:56-74. [PMID: 35181549 PMCID: PMC9119916 DOI: 10.1016/j.trsl.2022.02.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 01/20/2022] [Accepted: 02/10/2022] [Indexed: 12/19/2022]
Abstract
The cortactin gene (CTTN), encoding an actin-binding protein critically involved in cytoskeletal dynamics and endothelial cell (EC) barrier integrity, contains single nucleotide polymorphisms (SNPs) associated with severe asthma in Black patients. As loss of lung EC integrity is a major driver of mortality in the Acute Respiratory Distress Syndrome (ARDS), sepsis, and the acute chest syndrome (ACS), we speculated CTTN SNPs that alter EC barrier function will associate with clinical outcomes from these types of conditions in Black patients. In case-control studies, evaluation of a nonsynonymous CTTN coding SNP Ser484Asn (rs56162978, G/A) in a severe sepsis cohort (725 Black subjects) revealed significant association with increased risk of sepsis mortality. In a separate cohort of sickle cell disease (SCD) subjects with and without ACS (177 SCD Black subjects), significantly increased risk of ACS and increased ACS severity (need for mechanical ventilation) was observed in carriers of the A allele. Human lung EC expressing the cortactin S484N transgene exhibited: (i) delayed EC barrier recovery following thrombin-induced permeability; (ii) reduced levels of critical Tyr486 cortactin phosphorylation; (iii) inhibited binding to the cytoskeletal regulator, nmMLCK; and (iv) attenuated EC barrier-promoting lamellipodia dynamics and biophysical responses. ARDS-challenged Cttn+/- heterozygous mice exhibited increased lung vascular permeability (compared to wild-type mice) which was significantly attenuated by IV delivery of liposomes encargoed with CTTN WT transgene but not by CTTN S484N transgene. In summary, these studies suggest that the CTTN S484N coding SNP contributes to severity of inflammatory injury in Black patients, potentially via delayed vascular barrier restoration.
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Affiliation(s)
- Patrick Belvitch
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Nancy Casanova
- Department of Medicine, University of Arizona Health Sciences, Tucson, Arizona
| | - Xiaoguang Sun
- Department of Medicine, University of Arizona Health Sciences, Tucson, Arizona
| | - Sara M Camp
- Department of Medicine, University of Arizona Health Sciences, Tucson, Arizona
| | - Saad Sammani
- Department of Medicine, University of Arizona Health Sciences, Tucson, Arizona
| | | | - Joseph Mascarhenas
- Department of Medicine, University of Arizona Health Sciences, Tucson, Arizona
| | - Heather Lynn
- Department of Medicine, University of Arizona Health Sciences, Tucson, Arizona
| | - Djanybek Adyshev
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Jessica Siegler
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Ankit Desai
- Department of Medicine, Indiana University, Indianapolis, Indiana
| | - Laleh Seyed-Saadat
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Alicia Rizzo
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Christian Bime
- Department of Medicine, University of Arizona Health Sciences, Tucson, Arizona
| | - Gajendra S Shekhawat
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois
| | - Vinayak P Dravid
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois
| | - John P Reilly
- Division of Pulmonary, Allergy, and Critical Care Medicine and Lung Biology Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Tiffanie K Jones
- Division of Pulmonary, Allergy, and Critical Care Medicine and Lung Biology Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Rui Feng
- Department of Biostatistics, Epidemiology, and Informatics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Eleftheria Letsiou
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Nuala J Meyer
- Division of Pulmonary, Allergy, and Critical Care Medicine and Lung Biology Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Nathan Ellis
- Department of Medicine, University of Arizona Health Sciences, Tucson, Arizona
| | - Joe G N Garcia
- Department of Medicine, University of Arizona Health Sciences, Tucson, Arizona
| | - Steven M Dudek
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois.
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Bandela M, Belvitch P, Garcia JGN, Dudek SM. Cortactin in Lung Cell Function and Disease. Int J Mol Sci 2022; 23:4606. [PMID: 35562995 PMCID: PMC9101201 DOI: 10.3390/ijms23094606] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 04/18/2022] [Accepted: 04/19/2022] [Indexed: 11/30/2022] Open
Abstract
Cortactin (CTTN) is an actin-binding and cytoskeletal protein that is found in abundance in the cell cortex and other peripheral structures of most cell types. It was initially described as a target for Src-mediated phosphorylation at several tyrosine sites within CTTN, and post-translational modifications at these tyrosine sites are a primary regulator of its function. CTTN participates in multiple cellular functions that require cytoskeletal rearrangement, including lamellipodia formation, cell migration, invasion, and various other processes dependent upon the cell type involved. The role of CTTN in vascular endothelial cells is particularly important for promoting barrier integrity and inhibiting vascular permeability and tissue edema. To mediate its functional effects, CTTN undergoes multiple post-translational modifications and interacts with numerous other proteins to alter cytoskeletal structures and signaling mechanisms. In the present review, we briefly describe CTTN structure, post-translational modifications, and protein binding partners and then focus on its role in regulating cellular processes and well-established functional mechanisms, primarily in vascular endothelial cells and disease models. We then provide insights into how CTTN function affects the pathophysiology of multiple lung disorders, including acute lung injury syndromes, COPD, and asthma.
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Affiliation(s)
- Mounica Bandela
- Department of Biomedical Engineering, College of Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA;
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA;
| | - Patrick Belvitch
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA;
| | - Joe G. N. Garcia
- Department of Medicine, University of Arizona, Tucson, AZ 85721, USA;
| | - Steven M. Dudek
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA;
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Wang L, Letsiou E, Wang H, Belvitch P, Meliton LN, Brown ME, Bandela M, Chen J, Garcia JGN, Dudek SM. MRSA-induced endothelial permeability and acute lung injury are attenuated by FTY720 S-phosphonate. Am J Physiol Lung Cell Mol Physiol 2022; 322:L149-L161. [PMID: 35015568 PMCID: PMC8794017 DOI: 10.1152/ajplung.00100.2021] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Disruption of the lung endothelial barrier is a hallmark of acute respiratory distress syndrome (ARDS), for which no effective pharmacologic treatments exist. Prior work has demonstrated that FTY720 S-phosphonate (Tys), an analog of sphingosine-1-phosphate (S1P) and FTY720, exhibits potent endothelial cell (EC) barrier protective properties. In this study, we investigated the in vitro and in vivo efficacy of Tys against methicillin-resistant Staphylococcus aureus (MRSA), a frequent bacterial cause of ARDS. Tys-protected human lung EC from barrier disruption induced by heat-killed MRSA (HK-MRSA) or staphylococcal α-toxin and attenuated MRSA-induced cytoskeletal changes associated with barrier disruption, including actin stress fiber formation and loss of peripheral VE-cadherin and cortactin. Tys-inhibited Rho and myosin light chain (MLC) activation after MRSA and blocked MRSA-induced NF-κB activation and release of the proinflammatory cytokines, IL-6 and IL-8. In vivo, intratracheal administration of live MRSA in mice caused significant vascular leakage and leukocyte infiltration into the alveolar space. Pre- or posttreatment with Tys attenuated MRSA-induced lung permeability and levels of alveolar neutrophils. Posttreatment with Tys significantly reduced levels of bronchoalveolar lavage (BAL) VCAM-1 and plasma IL-6 and KC induced by MRSA. Dynamic intravital imaging of mouse lungs demonstrated Tys attenuation of HK-MRSA-induced interstitial edema and neutrophil infiltration into lung tissue. Tys did not directly inhibit MRSA growth or viability in vitro. In conclusion, Tys inhibits lung EC barrier disruption and proinflammatory signaling induced by MRSA in vitro and attenuates acute lung injury induced by MRSA in vivo. These results support the potential utility of Tys as a novel ARDS therapeutic strategy.
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Affiliation(s)
- Lichun Wang
- 1Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Eleftheria Letsiou
- 1Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Huashan Wang
- 1Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Patrick Belvitch
- 1Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Lucille N. Meliton
- 1Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Mary E. Brown
- 2Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota
| | - Mounica Bandela
- 1Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Jiwang Chen
- 1Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | | | - Steven M. Dudek
- 1Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
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7
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Cortactin Modulates Lung Endothelial Apoptosis Induced by Cigarette Smoke. Cells 2021; 10:cells10112869. [PMID: 34831092 PMCID: PMC8616125 DOI: 10.3390/cells10112869] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 10/19/2021] [Accepted: 10/20/2021] [Indexed: 12/19/2022] Open
Abstract
Cigarette smoke (CS) is the primary cause of Chronic Obstructive Pulmonary Disease (COPD), and an important pathophysiologic event in COPD is CS-induced apoptosis in lung endothelial cells (EC). Cortactin (CTTN) is a cytoskeletal actin-binding regulatory protein with modulation by Src-mediated tyrosine phosphorylation. Based upon data demonstrating reduced CTTN mRNA levels in the lungs of smokers compared to non-smokers, we hypothesized a functional role for CTTN in CS-induced mitochondrial ROS generation and apoptosis in lung EC. Exposure of cultured human lung EC to CS condensate (CSC) led to the rearrangement of the actin cytoskeleton and increased CTTN tyrosine phosphorylation (within hours). Exposure to CS significantly increased EC mitochondrial ROS generation and EC apoptosis. The functional role of CTTN in these CSC-induced EC responses was explored using cortactin siRNA to reduce its expression, and by using a blocking peptide for the CTTN SH3 domain, which is critical to cytoskeletal interactions. CTTN siRNA or blockade of its SH3 domain resulted in significantly increased EC mitochondrial ROS and apoptosis and augmented CSC-induced effects. Exposure of lung EC to e-cigarette condensate demonstrated similar results, with CTTN siRNA or SH3 domain blocking peptide increasing lung EC apoptosis. These data demonstrate a novel role for CTTN in modulating lung EC apoptosis induced by CS or e-cigarettes potentially providing new insights into COPD pathogenesis.
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Mascarenhas JB, Gaber AA, Larrinaga TM, Mayfield R, Novak S, Camp SM, Gregorio C, Jacobson JR, Cress AE, Dudek SM, Garcia JGN. EVL is a novel focal adhesion protein involved in the regulation of cytoskeletal dynamics and vascular permeability. Pulm Circ 2021; 11:20458940211049002. [PMID: 34631011 PMCID: PMC8493322 DOI: 10.1177/20458940211049002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 09/07/2021] [Indexed: 11/17/2022] Open
Abstract
Increases in lung vascular permeability is a cardinal feature of inflammatory disease and represents an imbalance in vascular contractile forces and barrier-restorative forces, with both forces highly dependent upon the actin cytoskeleton. The current study investigates the role of Ena-VASP-like (EVL), a member of the Ena-VASP family known to regulate the actin cytoskeleton, in regulating vascular permeability responses and lung endothelial cell barrier integrity. Utilizing changes in transendothelial electricial resistance (TEER) to measure endothelial cell barrier responses, we demonstrate that EVL expression regulates endothelial cell responses to both sphingosine-1-phospate (S1P), a vascular barrier-enhancing agonist, and to thrombin, a barrier-disrupting stimulus. Total internal reflection fluorescence demonstrates that EVL is present in endothelial cell focal adhesions and impacts focal adhesion size, distribution, and the number of focal adhesions generated in response to S1P and thrombin challenge, with the focal adhesion kinase (FAK) a key contributor in S1P-stimulated EVL-transduced endothelial cell but a limited role in thrombin-induced focal adhesion rearrangements. In summary, these data indicate that EVL is a focal adhesion protein intimately involved in regulation of cytoskeletal responses to endothelial cell barrier-altering stimuli. Keywords: cytoskeleton, vascular barrier, sphingosine-1-phosphate, thrombin, focal adhesion kinase (FAK), Ena-VASP like protein (EVL), cytoskeletal regulatory protein
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Affiliation(s)
| | - Amir A Gaber
- Department of Medicine, University of Arizona, Tucson, Arizona, USA
| | - Tania M Larrinaga
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, USA
| | - Rachel Mayfield
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, USA
| | - Stefanie Novak
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, USA
| | - Sara M Camp
- Department of Medicine, University of Arizona, Tucson, Arizona, USA
| | - Carol Gregorio
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, USA
| | - Jeffrey R Jacobson
- Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Anne E Cress
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, Arizona, USA
| | - Steven M Dudek
- Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Joe G N Garcia
- Department of Medicine, University of Arizona, Tucson, Arizona, USA
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Chatterjee V, Yang X, Ma Y, Cha B, Meegan JE, Wu M, Yuan SY. Endothelial microvesicles carrying Src-rich cargo impair adherens junction integrity and cytoskeleton homeostasis. Cardiovasc Res 2021; 116:1525-1538. [PMID: 31504252 PMCID: PMC7314637 DOI: 10.1093/cvr/cvz238] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 08/06/2019] [Accepted: 08/29/2019] [Indexed: 12/12/2022] Open
Abstract
Aims Microvesicles (MVs) conduct intercellular communication and impact diverse biological processes by transferring bioactive cargos to other cells. We investigated whether and how endothelial production of MVs contribute to vascular dysfunction during inflammation. Methods and results We measured the levels and molecular properties of endothelial-derived MVs (EC-MVs) from mouse plasma following a septic injury elicited by cecal ligation and puncture, as well as those from supernatants of cultured endothelial cells stimulated by inflammatory agents including cytokines, thrombin, and complement 5a. The mouse studies showed that sepsis caused a significant increase in total plasma vesicles and VE-cadherin+ EC-MVs compared to sham control. In cultured ECs, different inflammatory agents caused diverse patterns of EC-MV production and cargo contents. When topically applied to endothelial cells, EC-MVs induced a cytoskeleton-junction response characterized by myosin light chain phosphorylation, contractile fibre reorganization, VE-cadherin phosphorylation, and adherens junction dissociation, functionally measured as increased albumin transendothelial flux and decreased barrier resistance. The endothelial response was coupled with protein tyrosine phosphorylation promoted by MV cargo containing c-Src kinase, whereas MVs produced from c-Src deficient cells did not exert barrier-disrupting effects. Additionally, EC-MVs contribute to endothelial inflammatory injury by promoting neutrophil-endothelium adhesion and release of neutrophil extracellular traps containing citrullinated histones and myeloperoxidase, a response unaltered by c-Src knockdown. Conclusion Endothelial-derived microparticles cause endothelial barrier dysfunction by impairing adherens junctions and activating neutrophils. The signalling mechanisms underlying the endothelial cytoskeleton-junction response to EC-MVs involve protein phosphorylation promoted by MV cargo carrying c-Src. However, EC-MV-induced neutrophil activation was not dependent on c-Src.
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Affiliation(s)
- Victor Chatterjee
- Department of Molecular Pharmacology and Physiology, University of South Florida Morsani College of Medicine, Tampa, FL 33612, USA
| | - Xiaoyuan Yang
- Department of Molecular Pharmacology and Physiology, University of South Florida Morsani College of Medicine, Tampa, FL 33612, USA
| | - Yonggang Ma
- Department of Molecular Pharmacology and Physiology, University of South Florida Morsani College of Medicine, Tampa, FL 33612, USA
| | - Byeong Cha
- Department of Molecular Pharmacology and Physiology, University of South Florida Morsani College of Medicine, Tampa, FL 33612, USA
| | - Jamie E Meegan
- Department of Molecular Pharmacology and Physiology, University of South Florida Morsani College of Medicine, Tampa, FL 33612, USA
| | - Mack Wu
- Department of Surgery, University of South Florida Morsani College of Medicine, Tampa, FL 33612, USA
| | - Sarah Y Yuan
- Department of Molecular Pharmacology and Physiology, University of South Florida Morsani College of Medicine, Tampa, FL 33612, USA.,Department of Surgery, University of South Florida Morsani College of Medicine, Tampa, FL 33612, USA
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10
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Sharafutdinov I, Backert S, Tegtmeyer N. Cortactin: A Major Cellular Target of the Gastric Carcinogen Helicobacter pylori. Cancers (Basel) 2020; 12:E159. [PMID: 31936446 PMCID: PMC7017262 DOI: 10.3390/cancers12010159] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 01/04/2020] [Accepted: 01/06/2020] [Indexed: 12/19/2022] Open
Abstract
Cortactin is an actin binding protein and actin nucleation promoting factor regulating cytoskeletal rearrangements in nearly all eukaryotic cell types. From this perspective, cortactin poses an attractive target for pathogens to manipulate a given host cell to their own benefit. One of the pathogens following this strategy is Helicobacter pylori, which can cause a variety of gastric diseases and has been shown to be the major risk factor for the onset of gastric cancer. During infection of gastric epithelial cells, H. pylori hijacks the cellular kinase signaling pathways, leading to the disruption of key cell functions. Specifically, by overruling the phosphorylation status of cortactin, H. pylori alternates the activity of molecular interaction partners of this important protein, thereby manipulating the performance of actin-cytoskeletal rearrangements and cell movement. In addition, H. pylori utilizes a unique mechanism to activate focal adhesion kinase, which subsequently prevents host epithelial cells from extensive lifting from the extracellular matrix in order to achieve chronic infection in the human stomach.
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Affiliation(s)
| | | | - Nicole Tegtmeyer
- Division of Microbiology, Department of Biology, Friedrich Alexander University Erlangen-Nuremberg, Staudtstr. 5, D-91058 Erlangen, Germany; (I.S.); (S.B.)
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11
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Wang M, Gauthier A, Daley L, Dial K, Wu J, Woo J, Lin M, Ashby C, Mantell LL. The Role of HMGB1, a Nuclear Damage-Associated Molecular Pattern Molecule, in the Pathogenesis of Lung Diseases. Antioxid Redox Signal 2019; 31:954-993. [PMID: 31184204 PMCID: PMC6765066 DOI: 10.1089/ars.2019.7818] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 06/07/2019] [Indexed: 12/11/2022]
Abstract
Significance: High-mobility group protein box 1 (HMGB1), a ubiquitous nuclear protein, regulates chromatin structure and modulates the expression of many genes involved in the pathogenesis of lung cancer and many other lung diseases, including those that regulate cell cycle control, cell death, and DNA replication and repair. Extracellular HMGB1, whether passively released or actively secreted, is a danger signal that elicits proinflammatory responses, impairs macrophage phagocytosis and efferocytosis, and alters vascular remodeling. This can result in excessive pulmonary inflammation and compromised host defense against lung infections, causing a deleterious feedback cycle. Recent Advances: HMGB1 has been identified as a biomarker and mediator of the pathogenesis of numerous lung disorders. In addition, post-translational modifications of HMGB1, including acetylation, phosphorylation, and oxidation, have been postulated to affect its localization and physiological and pathophysiological effects, such as the initiation and progression of lung diseases. Critical Issues: The molecular mechanisms underlying how HMGB1 drives the pathogenesis of different lung diseases and novel therapeutic approaches targeting HMGB1 remain to be elucidated. Future Directions: Additional research is needed to identify the roles and functions of modified HMGB1 produced by different post-translational modifications and their significance in the pathogenesis of lung diseases. Such studies will provide information for novel approaches targeting HMGB1 as a treatment for lung diseases.
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Affiliation(s)
- Mao Wang
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, Queens, New York
| | - Alex Gauthier
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, Queens, New York
| | - LeeAnne Daley
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, Queens, New York
| | - Katelyn Dial
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, Queens, New York
| | - Jiaqi Wu
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, Queens, New York
| | - Joanna Woo
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, Queens, New York
| | - Mosi Lin
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, Queens, New York
| | - Charles Ashby
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, Queens, New York
| | - Lin L. Mantell
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, Queens, New York
- Center for Inflammation and Immunology, The Feinstein Institute for Medical Research, Northwell Health, Manhasset, New York
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12
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Mascarenhas JB, Tchourbanov AY, Danilov SM, Zhou T, Wang T, Garcia JGN. The Splicing Factor hnRNPA1 Regulates Alternate Splicing of the MYLK Gene. Am J Respir Cell Mol Biol 2019; 58:604-613. [PMID: 29077485 DOI: 10.1165/rcmb.2017-0141oc] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Profound lung vascular permeability is a cardinal feature of acute respiratory distress syndrome (ARDS) and ventilator-induced lung injury (VILI), two syndromes known to centrally involve the nonmuscle isoform of myosin light chain kinase (nmMLCK) in vascular barrier dysregulation. Two main splice variants, nmMLCK1 and nmMLCK2, are well represented in human lung endothelial cells and encoded by MYLK, and they differ only in the presence of exon 11 in nmMLCK1, which contains critical phosphorylation sites (Y464 and Y471) that influence nmMLCK enzymatic activity, cellular translocation, and localization in response to vascular agonists. We recently demonstrated the functional role of SNPs in altering MYLK splicing, and in the present study we sought to identify the role of splicing factors in the generation of nmMLCK1 and nmMLCK2 spliced variants. Using bioinformatic in silico approaches, we identified a putative binding site for heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1), a recognized splicing factor. We verified hnRNPA1 binding to MYLK by gel shift analyses and that hnRNPA1 gene and protein expression is upregulated in mouse lungs obtained from preclinical models of ARDS and VILI and in human endothelial cells exposed to 18% cyclic stretch, a model that reproduces the excessive mechanical stress observed in VILI. Using an MYLK minigene approach, we established a direct role of hnRNPA1 in MYLK splicing and in the context of 18% cyclic stretch. In summary, these data indicate an important regulatory role for hnRNPA1 in MYLK splicing, and they increase understanding of MYLK splicing in the regulation of lung vascular integrity during acute lung inflammation and excessive mechanical stress, such as that observed in ARDS and VILI.
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Affiliation(s)
| | | | - Sergei M Danilov
- 1 Department of Medicine, College of Medicine, and.,3 Department of Anesthesiology, University of Illinois at Chicago, Chicago, Illinois; and
| | - Tong Zhou
- 4 Department of Physiology and Cell Biology, The University of Nevada, Reno School of Medicine, Reno, Nevada
| | - Ting Wang
- 1 Department of Medicine, College of Medicine, and
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13
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Abstract
The pulmonary endothelial cell forms a critical semi-permeable barrier between the vascular and interstitial space. As part of the blood-gas barrier in the lung, the endothelium plays a key role in normal physiologic function and pathologic disease. Changes in endothelial cell shape, defined by its plasma membrane, determine barrier integrity. A number of key cytoskeletal regulatory and effector proteins including non-muscle myosin light chain kinase, cortactin, and Arp 2/3 mediate actin rearrangements to form cortical and membrane associated structures in response to barrier enhancing stimuli. These actin formations support and interact with junctional complexes and exert forces to protrude the lipid membrane to and close gaps between individual cells. The current knowledge of these cytoskeletal processes and regulatory proteins are the subject of this review. In addition, we explore novel advancements in cellular imaging that are poised to shed light on the complex nature of pulmonary endothelial permeability.
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14
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Theofilatos D, Fotakis P, Valanti E, Sanoudou D, Zannis V, Kardassis D. HDL-apoA-I induces the expression of angiopoietin like 4 (ANGPTL4) in endothelial cells via a PI3K/AKT/FOXO1 signaling pathway. Metabolism 2018; 87:36-47. [PMID: 29928895 DOI: 10.1016/j.metabol.2018.06.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 05/17/2018] [Accepted: 06/17/2018] [Indexed: 11/17/2022]
Abstract
BACKGROUND High Density Lipoprotein (HDL) and its main protein component, apolipoprotein A-I (apoA-I), have numerous atheroprotective functions on various tissues including the endothelium. Therapies based on reconstituted HDL containing apoA-I (rHDL-apoA-I) have been used successfully in patients with acute coronary syndrome, peripheral vascular disease or diabetes but very little is known about the genomic effects of rHDL-apoA-I and how they could contribute to atheroprotection. OBJECTIVE The present study aimed to understand the endothelial signaling pathways and the genes that may contribute to rHDL-apoA-I-mediated atheroprotection. METHODS Human aortic endothelial cells (HAECs) were treated with rHDL-apoA-I and their total RNA was analyzed with whole genome microarrays. Validation of microarray data was performed using multiplex RT-qPCR. The expression of ANGPTL4 in EA.hy926 endothelial cells was determined by RT-qPCR and Western blotting. The contribution of signaling kinases and transcription factors in ANGPTL4 gene regulation by HDL-apoA-I was assessed by RT-qPCR, Western blotting and immunofluorescence using chemical inhibitors or siRNA-mediated gene silencing. RESULTS It was found that 410 transcripts were significantly changed in the presence of rHDL-apoA-I and that angiopoietin like 4 (ANGPTL4) was one of the most upregulated and biologically relevant molecules. In validation experiments rHDL-apoA-I, as well as natural HDL from human healthy donors or from transgenic mice overexpressing human apoA-I (TgHDL-apoA-I), increased ANGPTL4 mRNA and protein levels. ANGPTL4 gene induction by HDL was direct and was blocked in the presence of inhibitors for the AKT or the p38 MAP kinases. TgHDL-apoA-I caused phosphorylation of the transcription factor forkhead box O1 (FOXO1) and its translocation from the nucleus to the cytoplasm. Importantly, a FOXO1 inhibitor or a FOXO1-specific siRNA enhanced ANGPTL4 expression, whereas administration of TgHDL-apoA-I in the presence of the FOXO1 inhibitor or the FOXO1-specific siRNA did not induce further ANGPTL4 expression. These data suggest that FOXO1 functions as an inhibitor of ANGPTL4, while HDL-apoA-I blocks FOXO1 activity and induces ANGPTL4 through the activation of AKT. CONCLUSION Our data provide novel insights into the global molecular effects of HDL-apoA-I on endothelial cells and identify ANGPTL4 as a putative mediator of the atheroprotective functions of HDL-apoA-I on the artery wall, with notable therapeutic potential.
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Affiliation(s)
- Dimitris Theofilatos
- Laboratory of Biochemistry, University of Crete School of Medicine, Heraklion, Greece; Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology of Hellas, Heraklion, Greece
| | - Panagiotis Fotakis
- Section of Molecular Genetics, Boston University Medical School, Boston, USA
| | - Efi Valanti
- 4th Department of Internal Medicine, "Attikon" Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Despina Sanoudou
- 4th Department of Internal Medicine, "Attikon" Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Vassilis Zannis
- Section of Molecular Genetics, Boston University Medical School, Boston, USA
| | - Dimitris Kardassis
- Laboratory of Biochemistry, University of Crete School of Medicine, Heraklion, Greece; Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology of Hellas, Heraklion, Greece.
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15
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Ramos-García P, González-Moles MÁ, González-Ruiz L, Ayén Á, Ruiz-Ávila I, Navarro-Triviño FJ, Gil-Montoya JA. An update of knowledge on cortactin as a metastatic driver and potential therapeutic target in oral squamous cell carcinoma. Oral Dis 2018; 25:949-971. [PMID: 29878474 DOI: 10.1111/odi.12913] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 05/15/2018] [Accepted: 06/05/2018] [Indexed: 12/12/2022]
Abstract
Cortactin is a protein encoded by the CTTN gene, localized on chromosome band 11q13. As a result of the amplification of this band, an important event in oral carcinogenesis, CTTN is also usually amplified, promoting the frequent overexpression of cortactin. Cortactin enhances cell migration in oral cancer, playing a key role in the regulation of filamentous actin and of protrusive structures (invadopodia and lamellipodia) on the cell membrane that are necessary for the acquisition of a migratory phenotype. We also analyze a series of emerging functions that cortactin may exert in oral cancer (cell proliferation, angiogenesis, regulation of exosomes, and interactions with the tumor microenvironment). We review its molecular structure, its most important interactions (with Src, Arp2/3 complex, and SH3-binding partners), the regulation of its functions, and its specific oncogenic role in oral cancer. We explore the mechanisms of its overexpression in cancer, mainly related to genetic amplification. We analyze the prognostic implications of the oncogenic activation of cortactin in potentially malignant disorders and in head and neck cancer, where it appears to be relevant in the development of lymph node metastasis. Finally, we discuss its usefulness as a therapeutic target and suggest future research lines.
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Affiliation(s)
| | - Miguel Ángel González-Moles
- School of Dentistry, University of Granada, Granada, Spain.,Instituto de Investigación Biosanitaria, Granada, Spain
| | - Lucía González-Ruiz
- Servicio de Dermatología, Hospital General Universitario de Ciudad Real, Ciudad Real, Spain
| | - Ángela Ayén
- School of Medicine, University of Granada, Granada, Spain
| | - Isabel Ruiz-Ávila
- Instituto de Investigación Biosanitaria, Granada, Spain.,Servicio de Anatomía Patológica, Complejo Hospitalario Universitario de Granada, Granada, Spain
| | | | - José Antonio Gil-Montoya
- School of Dentistry, University of Granada, Granada, Spain.,Instituto de Investigación Biosanitaria, Granada, Spain
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16
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Wang T, Brown ME, Kelly GT, Camp SM, Mascarenhas JB, Sun X, Dudek SM, Garcia JGN. Myosin light chain kinase ( MYLK) coding polymorphisms modulate human lung endothelial cell barrier responses via altered tyrosine phosphorylation, spatial localization, and lamellipodial protrusions. Pulm Circ 2018; 8:2045894018764171. [PMID: 29480069 PMCID: PMC5846938 DOI: 10.1177/2045894018764171] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Sphingosine 1-phosphate (S1P) is a potent bioactive endogenous lipid that signals a rearrangement of the actin cytoskeleton via the regulation of non-muscle myosin light chain kinase isoform (nmMLCK). S1P induces critical nmMLCK Y464 and Y471 phosphorylation resulting in translocation of nmMLCK to the periphery where spatially-directed increases in myosin light chain (MLC) phosphorylation and tension result in lamellipodia protrusion, increased cell-cell adhesion, and enhanced vascular barrier integrity. MYLK, the gene encoding nmMLCK, is a known candidate gene in lung inflammatory diseases, with coding genetic variants (Pro21His, Ser147Pro, Val261Ala) that confer risk for inflammatory lung injury and influence disease severity. The functional mechanisms by which these MYLK coding single nucleotide polymorphisms (SNPs) affect biologic processes to increase disease risk and severity remain elusive. In the current study, we utilized quantifiable cell immunofluorescence assays to determine the influence of MYLK coding SNPs on S1P-mediated nmMLCK phosphorylation and translocation to the human lung endothelial cell (EC) periphery . These disease-associated MYLK variants result in reduced levels of S1P-induced Y464 phosphorylation, a key site for nmMLCK enzymatic regulation and activation. Reduced Y464 phosphorylation resulted in attenuated nmMLCK protein translocation to the cell periphery. We further conducted EC kymographic assays which confirmed that lamellipodial protrusion in response to S1P challenge was retarded by expression of a MYLK transgene harboring the three MYLK coding SNPs. These data suggest that ARDS/severe asthma-associated MYLK SNPs functionally influence vascular barrier-regulatory cytoskeletal responses via direct alterations in the levels of nmMLCK tyrosine phosphorylation, spatial localization, and lamellipodial protrusions.
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Affiliation(s)
- Ting Wang
- 1 Department of Medicine, University of Arizona Health Sciences, Tucson, AZ, USA
| | - Mary E Brown
- 2 Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Gabriel T Kelly
- 1 Department of Medicine, University of Arizona Health Sciences, Tucson, AZ, USA
| | - Sara M Camp
- 1 Department of Medicine, University of Arizona Health Sciences, Tucson, AZ, USA
| | - Joseph B Mascarenhas
- 1 Department of Medicine, University of Arizona Health Sciences, Tucson, AZ, USA
| | - Xiaoguang Sun
- 1 Department of Medicine, University of Arizona Health Sciences, Tucson, AZ, USA
| | - Steven M Dudek
- 2 Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Joe G N Garcia
- 1 Department of Medicine, University of Arizona Health Sciences, Tucson, AZ, USA
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17
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Mascarenhas JB, Tchourbanov AY, Fan H, Danilov SM, Wang T, Garcia JGN. Mechanical Stress and Single Nucleotide Variants Regulate Alternative Splicing of the MYLK Gene. Am J Respir Cell Mol Biol 2017; 56:29-37. [PMID: 27529643 DOI: 10.1165/rcmb.2016-0053oc] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The nonmuscle (nm) myosin light-chain kinase isoform (MLCK), encoded by the MYLK gene, is a vital participant in regulating vascular barrier responses to mechanical and inflammatory stimuli. We determined that MYLK is alternatively spliced, yielding functionally distinct nmMLCK splice variants including nmMLCK2, a splice variant highly expressed in vascular endothelial cells (EC) and associated with reduced EC barrier integrity. We demonstrated previously that the nmMLCK2 variant lacks exon 11, which encodes a key regulatory region containing two differentially phosphorylated tyrosine residues (Y464 and Y471) that influence vascular barrier function during inflammation. In this study, we used minigene constructs and RT-PCR to interrogate biophysical factors (mechanical stress) and genetic variants (MYLK single-nucleotide polymorphisms [SNPs]) that are potentially involved in regulating MYLK alternative splicing and nmMLCK2 generation. Human lung EC exposed to pathologic mechanical stress (18% cyclic stretch) produced increased nmMLCK2 expression relative to levels of nmMLCK1 with alternative splicing significantly influenced by MYLK SNPs rs77323602 and rs147245669. In silico analyses predicted that these variants would alter exon 11 donor and acceptor sites for alternative splicing, computational predictions that were confirmed by minigene studies. The introduction of rs77323602 favored wild-type nmMLCK expression, whereas rs147245669 favored alternative splicing and deletion of exon 11, yielding increased nmMLCK2 expression. Finally, lymphoblastoid cell lines selectively harboring these MYLK SNPs (rs77323602 and rs147245669) directly validated SNP-specific effects on MYLK alternative splicing and nmMLCK2 generation. Together, these studies demonstrate that mechanical stress and MYLK SNPs regulate MYLK alternative splicing and generation of a splice variant, nmMLCK2, that contributes to the severity of inflammatory injury.
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Affiliation(s)
| | - Alex Y Tchourbanov
- 2 Arizona Research Laboratory, University of Arizona, Tucson, Arizona; and
| | - Hanli Fan
- 3 Department of Anesthesiology, University of Illinois at Chicago, Chicago, Illinois
| | - Sergei M Danilov
- 1 Department of Medicine, and.,3 Department of Anesthesiology, University of Illinois at Chicago, Chicago, Illinois
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18
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González-Jamett AM, Guerra MJ, Olivares MJ, Haro-Acuña V, Baéz-Matus X, Vásquez-Navarrete J, Momboisse F, Martinez-Quiles N, Cárdenas AM. The F-Actin Binding Protein Cortactin Regulates the Dynamics of the Exocytotic Fusion Pore through its SH3 Domain. Front Cell Neurosci 2017; 11:130. [PMID: 28522963 PMCID: PMC5415606 DOI: 10.3389/fncel.2017.00130] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 04/18/2017] [Indexed: 11/20/2022] Open
Abstract
Upon cell stimulation, the network of cortical actin filaments is rearranged to facilitate the neurosecretory process. This actin rearrangement includes both disruption of the preexisting actin network and de novo actin polymerization. However, the mechanism by which a Ca2+ signal elicits the formation of new actin filaments remains uncertain. Cortactin, an actin-binding protein that promotes actin polymerization in synergy with the nucleation promoting factor N-WASP, could play a key role in this mechanism. We addressed this hypothesis by analyzing de novo actin polymerization and exocytosis in bovine adrenal chromaffin cells expressing different cortactin or N-WASP domains, or cortactin mutants that fail to interact with proline-rich domain (PRD)-containing proteins, including N-WASP, or to be phosphorylated by Ca2+-dependent kinases, such as ERK1/2 and Src. Our results show that the activation of nicotinic receptors in chromaffin cells promotes cortactin translocation to the cell cortex, where it colocalizes with actin filaments. We further found that, in association with PRD-containing proteins, cortactin contributes to the Ca2+-dependent formation of F-actin, and regulates fusion pore dynamics and the number of exocytotic events induced by activation of nicotinic receptors. However, whereas the actions of cortactin on the fusion pore dynamics seems to depend on the availability of monomeric actin and its phosphorylation by ERK1/2 and Src kinases, cortactin regulates the extent of exocytosis by a mechanism independent of actin polymerization. Together our findings point out a role for cortactin as a critical modulator of actin filament formation and exocytosis in neuroendocrine cells.
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Affiliation(s)
- Arlek M González-Jamett
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de ValparaísoValparaíso, Chile
| | - María J Guerra
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de ValparaísoValparaíso, Chile
| | - María J Olivares
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de ValparaísoValparaíso, Chile
| | - Valentina Haro-Acuña
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de ValparaísoValparaíso, Chile
| | - Ximena Baéz-Matus
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de ValparaísoValparaíso, Chile
| | - Jacqueline Vásquez-Navarrete
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de ValparaísoValparaíso, Chile
| | - Fanny Momboisse
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de ValparaísoValparaíso, Chile
| | - Narcisa Martinez-Quiles
- Departamento de Microbiología (Inmunología), Facultad de Medicina, Universidad Complutense de MadridMadrid, Spain
| | - Ana M Cárdenas
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de ValparaísoValparaíso, Chile
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19
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Khapchaev AY, Shirinsky VP. Myosin Light Chain Kinase MYLK1: Anatomy, Interactions, Functions, and Regulation. BIOCHEMISTRY (MOSCOW) 2017; 81:1676-1697. [PMID: 28260490 DOI: 10.1134/s000629791613006x] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
This review discusses and summarizes the results of molecular and cellular investigations of myosin light chain kinase (MLCK, MYLK1), the key regulator of cell motility. The structure and regulation of a complex mylk1 gene and the domain organization of its products is presented. The interactions of the mylk1 gene protein products with other proteins and posttranslational modifications of the mylk1 gene protein products are reviewed, which altogether might determine the role and place of MLCK in physiological and pathological reactions of cells and entire organisms. Translational potential of MLCK as a drug target is evaluated.
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Affiliation(s)
- A Y Khapchaev
- Russian Cardiology Research and Production Center, Moscow, 121552, Russia.
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20
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Wang T, Gross C, Desai AA, Zemskov E, Wu X, Garcia AN, Jacobson JR, Yuan JXJ, Garcia JGN, Black SM. Endothelial cell signaling and ventilator-induced lung injury: molecular mechanisms, genomic analyses, and therapeutic targets. Am J Physiol Lung Cell Mol Physiol 2016; 312:L452-L476. [PMID: 27979857 DOI: 10.1152/ajplung.00231.2016] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 12/08/2016] [Accepted: 12/11/2016] [Indexed: 12/13/2022] Open
Abstract
Mechanical ventilation is a life-saving intervention in critically ill patients with respiratory failure due to acute respiratory distress syndrome (ARDS). Paradoxically, mechanical ventilation also creates excessive mechanical stress that directly augments lung injury, a syndrome known as ventilator-induced lung injury (VILI). The pathobiology of VILI and ARDS shares many inflammatory features including increases in lung vascular permeability due to loss of endothelial cell barrier integrity resulting in alveolar flooding. While there have been advances in the understanding of certain elements of VILI and ARDS pathobiology, such as defining the importance of lung inflammatory leukocyte infiltration and highly induced cytokine expression, a deep understanding of the initiating and regulatory pathways involved in these inflammatory responses remains poorly understood. Prevailing evidence indicates that loss of endothelial barrier function plays a primary role in the development of VILI and ARDS. Thus this review will focus on the latest knowledge related to 1) the key role of the endothelium in the pathogenesis of VILI; 2) the transcription factors that relay the effects of excessive mechanical stress in the endothelium; 3) the mechanical stress-induced posttranslational modifications that influence key signaling pathways involved in VILI responses in the endothelium; 4) the genetic and epigenetic regulation of key target genes in the endothelium that are involved in VILI responses; and 5) the need for novel therapeutic strategies for VILI that can preserve endothelial barrier function.
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Affiliation(s)
- Ting Wang
- Department of Medicine, The University of Arizona Health Sciences, Tucson, Arizona
| | - Christine Gross
- Vascular Biology Center, Augusta University, Augusta, Georgia
| | - Ankit A Desai
- Department of Medicine, The University of Arizona Health Sciences, Tucson, Arizona
| | - Evgeny Zemskov
- Department of Medicine, The University of Arizona Health Sciences, Tucson, Arizona
| | - Xiaomin Wu
- Department of Medicine, The University of Arizona Health Sciences, Tucson, Arizona
| | - Alexander N Garcia
- Department of Pharmacology University of Illinois at Chicago, Chicago, Illinois; and
| | - Jeffrey R Jacobson
- Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Jason X-J Yuan
- Department of Medicine, The University of Arizona Health Sciences, Tucson, Arizona
| | - Joe G N Garcia
- Department of Medicine, The University of Arizona Health Sciences, Tucson, Arizona
| | - Stephen M Black
- Department of Medicine, The University of Arizona Health Sciences, Tucson, Arizona;
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21
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Shentu TP, He M, Sun X, Zhang J, Zhang F, Gongol B, Marin TL, Zhang J, Wen L, Wang Y, Geary GG, Zhu Y, Johnson DA, Shyy JYJ. AMP-Activated Protein Kinase and Sirtuin 1 Coregulation of Cortactin Contributes to Endothelial Function. Arterioscler Thromb Vasc Biol 2016; 36:2358-2368. [PMID: 27758765 DOI: 10.1161/atvbaha.116.307871] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 09/12/2016] [Indexed: 12/23/2022]
Abstract
OBJECTIVE Cortactin translocates to the cell periphery in vascular endothelial cells (ECs) on cortical-actin assembly in response to pulsatile shear stress. Because cortactin has putative sites for AMP-activated protein kinase (AMPK) phosphorylation and sirtuin 1 (SIRT1) deacetylation, we examined the hypothesis that AMPK and SIRT1 coregulate cortactin dynamics in response to shear stress. APPROACH AND RESULTS Analysis of the ability of AMPK to phosphorylate recombinant cortactin and oligopeptides whose sequences matched AMPK consensus sequences in cortactin pointed to Thr-401 as the site of AMPK phosphorylation. Mass spectrometry confirmed Thr-401 as the site of AMPK phosphorylation. Immunoblot analysis with AMPK siRNA and SIRT1 siRNA in human umbilical vein ECs and EC-specific AMPKα2 knockout mice showed that AMPK phosphorylation of cortactin primes SIRT1 deacetylation in response to shear stress. Immunoblot analyses with cortactin siRNA in human umbilical vein ECs, phospho-deficient T401A and phospho-mimetic T401D mutant, or aceto-deficient (9K/R) and aceto-mimetic (9K/Q) showed that cortactin regulates endothelial nitric oxide synthase activity. Confocal imaging and sucrose-density gradient analyses revealed that the phosphorylated/deacetylated cortactin translocates to the EC periphery facilitating endothelial nitric oxide synthase translocation from lipid to nonlipid raft domains. Knockdown of cortactin in vitro or genetic reduction of cortactin expression in vivo in mice substantially decreased the endothelial nitric oxide synthase-derived NO bioavailability. In vivo, atherosclerotic lesions increase in ApoE-/-/cortactin+/- mice, when compared with ApoE-/-/cortactin+/+ littermates. CONCLUSIONS AMPK phosphorylation of cortactin followed by SIRT1 deacetylation modulates the interaction of cortactin and cortical-actin in response to shear stress. Functionally, this AMPK/SIRT1 coregulated cortactin-F-actin dynamics is required for endothelial nitric oxide synthase subcellular translocation/activation and is atheroprotective.
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Affiliation(s)
- Tzu-Pin Shentu
- From the Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla (T.-P.S., M.H., J.Z., J.Z.; L.W., J.Y.-J.S.); Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China (X.S., Y.Z.); Department of Chemistry, University of California, Riverside (F.Z., Y.W.); Department of Cardiopulmonary Sciences, Schools of Allied Health, Loma Linda University, CA (B.G., T.L.M.); Department of Kinesiology and Health Sciences, California State University, San Bernardino (G.G.G.); and Division of Biomedical Sciences, University of California, Riverside (D.A.J.)
| | - Ming He
- From the Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla (T.-P.S., M.H., J.Z., J.Z.; L.W., J.Y.-J.S.); Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China (X.S., Y.Z.); Department of Chemistry, University of California, Riverside (F.Z., Y.W.); Department of Cardiopulmonary Sciences, Schools of Allied Health, Loma Linda University, CA (B.G., T.L.M.); Department of Kinesiology and Health Sciences, California State University, San Bernardino (G.G.G.); and Division of Biomedical Sciences, University of California, Riverside (D.A.J.)
| | - Xiaoli Sun
- From the Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla (T.-P.S., M.H., J.Z., J.Z.; L.W., J.Y.-J.S.); Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China (X.S., Y.Z.); Department of Chemistry, University of California, Riverside (F.Z., Y.W.); Department of Cardiopulmonary Sciences, Schools of Allied Health, Loma Linda University, CA (B.G., T.L.M.); Department of Kinesiology and Health Sciences, California State University, San Bernardino (G.G.G.); and Division of Biomedical Sciences, University of California, Riverside (D.A.J.)
| | - Jianlin Zhang
- From the Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla (T.-P.S., M.H., J.Z., J.Z.; L.W., J.Y.-J.S.); Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China (X.S., Y.Z.); Department of Chemistry, University of California, Riverside (F.Z., Y.W.); Department of Cardiopulmonary Sciences, Schools of Allied Health, Loma Linda University, CA (B.G., T.L.M.); Department of Kinesiology and Health Sciences, California State University, San Bernardino (G.G.G.); and Division of Biomedical Sciences, University of California, Riverside (D.A.J.)
| | - Fan Zhang
- From the Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla (T.-P.S., M.H., J.Z., J.Z.; L.W., J.Y.-J.S.); Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China (X.S., Y.Z.); Department of Chemistry, University of California, Riverside (F.Z., Y.W.); Department of Cardiopulmonary Sciences, Schools of Allied Health, Loma Linda University, CA (B.G., T.L.M.); Department of Kinesiology and Health Sciences, California State University, San Bernardino (G.G.G.); and Division of Biomedical Sciences, University of California, Riverside (D.A.J.)
| | - Brendan Gongol
- From the Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla (T.-P.S., M.H., J.Z., J.Z.; L.W., J.Y.-J.S.); Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China (X.S., Y.Z.); Department of Chemistry, University of California, Riverside (F.Z., Y.W.); Department of Cardiopulmonary Sciences, Schools of Allied Health, Loma Linda University, CA (B.G., T.L.M.); Department of Kinesiology and Health Sciences, California State University, San Bernardino (G.G.G.); and Division of Biomedical Sciences, University of California, Riverside (D.A.J.)
| | - Traci L Marin
- From the Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla (T.-P.S., M.H., J.Z., J.Z.; L.W., J.Y.-J.S.); Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China (X.S., Y.Z.); Department of Chemistry, University of California, Riverside (F.Z., Y.W.); Department of Cardiopulmonary Sciences, Schools of Allied Health, Loma Linda University, CA (B.G., T.L.M.); Department of Kinesiology and Health Sciences, California State University, San Bernardino (G.G.G.); and Division of Biomedical Sciences, University of California, Riverside (D.A.J.)
| | - Jiao Zhang
- From the Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla (T.-P.S., M.H., J.Z., J.Z.; L.W., J.Y.-J.S.); Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China (X.S., Y.Z.); Department of Chemistry, University of California, Riverside (F.Z., Y.W.); Department of Cardiopulmonary Sciences, Schools of Allied Health, Loma Linda University, CA (B.G., T.L.M.); Department of Kinesiology and Health Sciences, California State University, San Bernardino (G.G.G.); and Division of Biomedical Sciences, University of California, Riverside (D.A.J.)
| | - Liang Wen
- From the Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla (T.-P.S., M.H., J.Z., J.Z.; L.W., J.Y.-J.S.); Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China (X.S., Y.Z.); Department of Chemistry, University of California, Riverside (F.Z., Y.W.); Department of Cardiopulmonary Sciences, Schools of Allied Health, Loma Linda University, CA (B.G., T.L.M.); Department of Kinesiology and Health Sciences, California State University, San Bernardino (G.G.G.); and Division of Biomedical Sciences, University of California, Riverside (D.A.J.)
| | - Yinsheng Wang
- From the Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla (T.-P.S., M.H., J.Z., J.Z.; L.W., J.Y.-J.S.); Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China (X.S., Y.Z.); Department of Chemistry, University of California, Riverside (F.Z., Y.W.); Department of Cardiopulmonary Sciences, Schools of Allied Health, Loma Linda University, CA (B.G., T.L.M.); Department of Kinesiology and Health Sciences, California State University, San Bernardino (G.G.G.); and Division of Biomedical Sciences, University of California, Riverside (D.A.J.)
| | - Gregory G Geary
- From the Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla (T.-P.S., M.H., J.Z., J.Z.; L.W., J.Y.-J.S.); Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China (X.S., Y.Z.); Department of Chemistry, University of California, Riverside (F.Z., Y.W.); Department of Cardiopulmonary Sciences, Schools of Allied Health, Loma Linda University, CA (B.G., T.L.M.); Department of Kinesiology and Health Sciences, California State University, San Bernardino (G.G.G.); and Division of Biomedical Sciences, University of California, Riverside (D.A.J.)
| | - Yi Zhu
- From the Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla (T.-P.S., M.H., J.Z., J.Z.; L.W., J.Y.-J.S.); Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China (X.S., Y.Z.); Department of Chemistry, University of California, Riverside (F.Z., Y.W.); Department of Cardiopulmonary Sciences, Schools of Allied Health, Loma Linda University, CA (B.G., T.L.M.); Department of Kinesiology and Health Sciences, California State University, San Bernardino (G.G.G.); and Division of Biomedical Sciences, University of California, Riverside (D.A.J.)
| | - David A Johnson
- From the Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla (T.-P.S., M.H., J.Z., J.Z.; L.W., J.Y.-J.S.); Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China (X.S., Y.Z.); Department of Chemistry, University of California, Riverside (F.Z., Y.W.); Department of Cardiopulmonary Sciences, Schools of Allied Health, Loma Linda University, CA (B.G., T.L.M.); Department of Kinesiology and Health Sciences, California State University, San Bernardino (G.G.G.); and Division of Biomedical Sciences, University of California, Riverside (D.A.J.)
| | - John Y-J Shyy
- From the Division of Cardiology, Department of Medicine, University of California, San Diego, La Jolla (T.-P.S., M.H., J.Z., J.Z.; L.W., J.Y.-J.S.); Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China (X.S., Y.Z.); Department of Chemistry, University of California, Riverside (F.Z., Y.W.); Department of Cardiopulmonary Sciences, Schools of Allied Health, Loma Linda University, CA (B.G., T.L.M.); Department of Kinesiology and Health Sciences, California State University, San Bernardino (G.G.G.); and Division of Biomedical Sciences, University of California, Riverside (D.A.J.).
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22
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Sulaiman SA, Ab Mutalib NS, Jamal R. miR-200c Regulation of Metastases in Ovarian Cancer: Potential Role in Epithelial and Mesenchymal Transition. Front Pharmacol 2016; 7:271. [PMID: 27601996 PMCID: PMC4993756 DOI: 10.3389/fphar.2016.00271] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 08/10/2016] [Indexed: 12/20/2022] Open
Abstract
Among the gynecological malignancies, ovarian cancer is the most fatal due to its high mortality rate. Most of the identified cases are epithelial ovarian cancer (EOC) with five distinct subtypes: high-grade serous carcinoma, low-grade serous carcinoma, mucinous carcinoma, endometrioid carcinoma, and clear-cell carcinoma. Lack of an early diagnostic approach, high incidence of tumor relapse and the heterogenous characteristics between each EOC subtypes contribute to the difficulties in developing precise intervention and therapy for the patients. MicroRNAs (miRNAs) are single-stranded RNAs that have been shown to function as tumor suppressors or oncomiRs. The miR-200 family, especially miR-200c, has been shown to be implicated in the metastasis and invasion of ovarian carcinoma due to its functional regulation of epithelial-to-mesenchymal transition (EMT). This mini review is aimed to summarize the recent findings of the miR-200c functional role as well as its validated targets in the metastasis cascade of ovarian cancer, with a focus on EMT regulation. The potential of this miRNA in early diagnosis and its dual expression status are also discussed.
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Affiliation(s)
- Siti A Sulaiman
- UKM Medical Molecular Biology Institute, UKM Medical Centre, Universiti Kebangsaan Malaysia Kuala Lumpur, Malaysia
| | - Nurul-Syakima Ab Mutalib
- UKM Medical Molecular Biology Institute, UKM Medical Centre, Universiti Kebangsaan Malaysia Kuala Lumpur, Malaysia
| | - Rahman Jamal
- UKM Medical Molecular Biology Institute, UKM Medical Centre, Universiti Kebangsaan Malaysia Kuala Lumpur, Malaysia
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23
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Vilitkevich EL, Khapchaev AY, Kudryashov DS, Nikashin AV, Schavocky JP, Lukas TJ, Watterson DM, Shirinsky VP. Phosphorylation Regulates Interaction of 210-kDa Myosin Light Chain Kinase N-terminal Domain with Actin Cytoskeleton. BIOCHEMISTRY (MOSCOW) 2016; 80:1288-97. [PMID: 26567572 DOI: 10.1134/s0006297915100090] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
High molecular weight myosin light chain kinase (MLCK210) is a multifunctional protein involved in myosin II activation and integration of cytoskeletal components in cells. MLCK210 possesses actin-binding regions both in the central part of the molecule and in its N-terminal tail domain. In HeLa cells, mitotic protein kinase Aurora B was suggested to phosphorylate MLCK210 N-terminal tail at serine residues (Dulyaninova, N. G., and Bresnick, A. R. (2004) Exp. Cell Res., 299, 303-314), but the functional significance of the phosphorylation was not established. We report here that in vitro, the N-terminal actin-binding domain of MLCK210 is located within residues 27-157 (N27-157, avian MLCK210 sequence) and is phosphorylated by cAMP-dependent protein kinase (PKA) and Aurora B at serine residues 140/149 leading to a decrease in N27-157 binding to actin. The same residues are phosphorylated in a PKA-dependent manner in transfected HeLa cells. Further, in transfected cells, phosphomimetic mutants of N27-157 showed reduced association with the detergent-stable cytoskeleton, whereas in vitro, the single S149D mutation reduced N27-157 association with F-actin to a similar extent as that achieved by N27-157 phosphorylation. Altogether, our results indicate that phosphorylation of MLCK210 at distinct serine residues, mainly at S149, attenuates the interaction of MLCK210 N-terminus with the actin cytoskeleton and might serve to regulate MLCK210 microfilament cross-linking activity in cells.
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Affiliation(s)
- E L Vilitkevich
- Russian Cardiology Research and Production Center, Moscow, 121552, Russia.
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24
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Sundararajan V, Gengenbacher N, Stemmler MP, Kleemann JA, Brabletz T, Brabletz S. The ZEB1/miR-200c feedback loop regulates invasion via actin interacting proteins MYLK and TKS5. Oncotarget 2016; 6:27083-96. [PMID: 26334100 PMCID: PMC4694975 DOI: 10.18632/oncotarget.4807] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 08/07/2015] [Indexed: 02/06/2023] Open
Abstract
Epithelial to mesenchymal transition (EMT) is a developmental process which is aberrantly activated during cancer invasion and metastasis. Elevated expression of EMT-inducers like ZEB1 enables tumor cells to detach from the primary tumor and invade into the surrounding tissue. The main antagonist of ZEB1 in controlling EMT is the microRNA-200 family that is reciprocally linked to ZEB1 in a double negative feedback loop. Here, we further elucidate how the ZEB1/miR-200 feedback loop controls invasion of tumor cells. The process of EMT is attended by major changes in the actin cytoskeleton. Via in silico screening of genes encoding for actin interacting proteins, we identified two novel targets of miR-200c - TKS5 and MYLK (MLCK). Co-expression of both genes with ZEB1 was observed in several cancer cell lines as well as in breast cancer patients and correlated with low miR-200c levels. Depletion of TKS5 or MYLK in breast cancer cells reduced their invasive potential and their ability to form invadopodia. Whereas TKS5 is known to be a major component, we could identify MYLK as a novel player in invadopodia formation. In summary, TKS5 and MYLK represent two mediators of invasive behavior of cancer cells that are regulated by the ZEB1/miR-200 feedback loop.
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Affiliation(s)
- Vignesh Sundararajan
- Department of Visceral Surgery, University Medical Center Freiburg, Freiburg, Germany.,Spemann Graduate School of Biology and Medicine (SGBM), Albert-Ludwigs-University Freiburg, Freiburg, Germany.,Faculty of Biology, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Nicolas Gengenbacher
- Division of Vascular Oncology and Metastasis, German Cancer Research Center (DKFZ-ZMBH Alliance), Heidelberg, Germany
| | - Marc P Stemmler
- Department of Experimental Medicine I, Nikolaus-Fiebiger-Center for Molecular Medicine, University Erlangen-Nürnberg, Erlangen, Germany
| | - Julia A Kleemann
- Department of Experimental Medicine I, Nikolaus-Fiebiger-Center for Molecular Medicine, University Erlangen-Nürnberg, Erlangen, Germany
| | - Thomas Brabletz
- Department of Experimental Medicine I, Nikolaus-Fiebiger-Center for Molecular Medicine, University Erlangen-Nürnberg, Erlangen, Germany
| | - Simone Brabletz
- Department of Experimental Medicine I, Nikolaus-Fiebiger-Center for Molecular Medicine, University Erlangen-Nürnberg, Erlangen, Germany
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25
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García Ponce A, Citalán Madrid AF, Vargas Robles H, Chánez Paredes S, Nava P, Betanzos A, Zarbock A, Rottner K, Vestweber D, Schnoor M. Loss of cortactin causes endothelial barrier dysfunction via disturbed adrenomedullin secretion and actomyosin contractility. Sci Rep 2016; 6:29003. [PMID: 27357373 PMCID: PMC4928053 DOI: 10.1038/srep29003] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 06/13/2016] [Indexed: 12/28/2022] Open
Abstract
Changes in vascular permeability occur during inflammation and the actin cytoskeleton plays a crucial role in regulating endothelial cell contacts and permeability. We demonstrated recently that the actin-binding protein cortactin regulates vascular permeability via Rap1. However, it is unknown if the actin cytoskeleton contributes to increased vascular permeability without cortactin. As we consistently observed more actin fibres in cortactin-depleted endothelial cells, we hypothesised that cortactin depletion results in increased stress fibre contractility and endothelial barrier destabilisation. Analysing the contractile machinery, we found increased ROCK1 protein levels in cortactin-depleted endothelium. Concomitantly, myosin light chain phosphorylation was increased while cofilin, mDia and ERM were unaffected. Secretion of the barrier-stabilising hormone adrenomedullin, which activates Rap1 and counteracts actomyosin contractility, was reduced in plasma from cortactin-deficient mice and in supernatants of cortactin-depleted endothelium. Importantly, adrenomedullin administration and ROCK1 inhibition reduced actomyosin contractility and rescued the effect on permeability provoked by cortactin deficiency in vitro and in vivo. Our data suggest a new role for cortactin in controlling actomyosin contractility with consequences for endothelial barrier integrity.
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Affiliation(s)
- Alexander García Ponce
- Department for Molecular Biomedicine, Center of Research and Advanced Studies (CINVESTAV-IPN), 07360 Mexico-City, Mexico
| | - Alí F Citalán Madrid
- Department for Molecular Biomedicine, Center of Research and Advanced Studies (CINVESTAV-IPN), 07360 Mexico-City, Mexico
| | - Hilda Vargas Robles
- Department for Molecular Biomedicine, Center of Research and Advanced Studies (CINVESTAV-IPN), 07360 Mexico-City, Mexico
| | - Sandra Chánez Paredes
- Department for Molecular Biomedicine, Center of Research and Advanced Studies (CINVESTAV-IPN), 07360 Mexico-City, Mexico
| | - Porfirio Nava
- Department for Physiology, Biophysics and Neurosciences, Center of Research and Advanced Studies (CINVESTAV-IPN), 07360 Mexico-City, Mexico
| | - Abigail Betanzos
- Department for Infectomics and Molecular Pathogenesis, Center of Research and Advanced Studies (CINVESTAV-IPN), 07360 Mexico-City, Mexico
| | - Alexander Zarbock
- Department of Anesthesiology, Intensive Care and Pain Medicine, University Clinic of Münster, 48149 Münster, Germany
| | - Klemens Rottner
- Division of Molecular Cell Biology, Zoological Institute, TU Braunschweig, 38106 Braunschweig, Germany.,Department of Cell Biology, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Dietmar Vestweber
- Department for Vascular Cell Biology, Max-Planck-Institute for Molecular Biomedicine, 48149 Münster, Germany
| | - Michael Schnoor
- Department for Molecular Biomedicine, Center of Research and Advanced Studies (CINVESTAV-IPN), 07360 Mexico-City, Mexico
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26
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Kim DY, Helfman DM. Loss of MLCK leads to disruption of cell-cell adhesion and invasive behavior of breast epithelial cells via increased expression of EGFR and ERK/JNK signaling. Oncogene 2016; 35:4495-508. [PMID: 26876209 DOI: 10.1038/onc.2015.508] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 12/09/2015] [Accepted: 12/14/2015] [Indexed: 01/15/2023]
Abstract
Myosin light chain kinase (MLCK) expression is downregulated in breast cancer, including invasive ductal carcinoma compared with ductal breast carcinoma in situ and metastatic breast tumors. However, little is known about how loss of MLCK expression contributes to tumor progression. MLCK is a component of the actin cytoskeleton and its known role is the phosphorylation of the regulatory light chain of myosin II. To gain insights into the role of MLCK in breast cancer, we perturbed its function using small interfering RNA (siRNA) or pharmacological inhibition in untransformed breast epithelial cells (MCF10A). Loss of MLCK by siRNAs led to increased cell migration and invasion, disruption of cell-cell adhesions and enhanced formation of focal adhesions at the leading edge of migratory cells. In addition, downregulation of MLCK cooperated with HER2 in MCF10A cells to promote cell migration and invasion and low levels of MLCK is associated with a poor prognosis in HER2-positive breast cancer patients. Associated with these altered migratory behaviors were increased expression of epidermal growth factor receptor and activation of extracellular signal-regulated kinase and c-Jun N-terminal kinase signaling pathways in MLCK downregulated MCF10A cells. By contrast, inhibition of the kinase function of MLCK using pharmacological agents inhibited cell migration and invasion, and did not affect cellular adhesions. Our results show that loss of MLCK contributes to the migratory properties of epithelial cells resulting from changes in cell-cell and cell-matrix adhesions, and increased epidermal growth factor receptor signaling. These findings suggest that decreased expression of MLCK may have a critical role during tumor progression by facilitating the metastatic potential of tumor cells.
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Affiliation(s)
- D Y Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Korea
| | - D M Helfman
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Korea
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27
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Shen K, Ramirez B, Mapes B, Shen GR, Gokhale V, Brown ME, Santarsiero B, Ishii Y, Dudek SM, Wang T, Garcia JGN. Structure-Function Analysis of the Non-Muscle Myosin Light Chain Kinase (nmMLCK) Isoform by NMR Spectroscopy and Molecular Modeling: Influence of MYLK Variants. PLoS One 2015; 10:e0130515. [PMID: 26111161 PMCID: PMC4482139 DOI: 10.1371/journal.pone.0130515] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 05/22/2015] [Indexed: 01/29/2023] Open
Abstract
The MYLK gene encodes the multifunctional enzyme, myosin light chain kinase (MLCK), involved in isoform-specific non-muscle and smooth muscle contraction and regulation of vascular permeability during inflammation. Three MYLK SNPs (P21H, S147P, V261A) alter the N-terminal amino acid sequence of the non-muscle isoform of MLCK (nmMLCK) and are highly associated with susceptibility to acute lung injury (ALI) and asthma, especially in individuals of African descent. To understand the functional effects of SNP associations, we examined the N-terminal segments of nmMLCK by 1H-15N heteronuclear single quantum correlation (HSQC) spectroscopy, a 2-D NMR technique, and by in silico molecular modeling. Both NMR analysis and molecular modeling indicated SNP localization to loops that connect the immunoglobulin-like domains of nmMLCK, consistent with minimal structural changes evoked by these SNPs. Molecular modeling analysis identified protein-protein interaction motifs adversely affected by these MYLK SNPs including binding by the scaffold protein 14-3-3, results confirmed by immunoprecipitation and western blot studies. These structure-function studies suggest novel mechanisms for nmMLCK regulation, which may confirm MYLK as a candidate gene in inflammatory lung disease and advance knowledge of the genetic underpinning of lung-related health disparities.
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Affiliation(s)
- Kui Shen
- Institute for Personalized Respiratory Medicine, Section of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Benjamin Ramirez
- Center for Structural Biology, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Brandon Mapes
- Institute for Personalized Respiratory Medicine, Section of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Grace R. Shen
- Institute for Personalized Respiratory Medicine, Section of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Vijay Gokhale
- College of Pharmacy and BIO5 Institute, University of Arizona, Tucson, Arizona, United States of America
| | - Mary E. Brown
- Institute for Personalized Respiratory Medicine, Section of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Bernard Santarsiero
- Center for Structural Biology, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Yoshitaka Ishii
- Center for Structural Biology, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Steven M. Dudek
- Institute for Personalized Respiratory Medicine, Section of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Ting Wang
- Institute for Personalized Respiratory Medicine, Section of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois at Chicago, Chicago, Illinois, United States of America
- Arizona Respiratory Center and Department of Medicine, University of Arizona, Tucson, Arizona, United States of America
| | - Joe G. N. Garcia
- Institute for Personalized Respiratory Medicine, Section of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois at Chicago, Chicago, Illinois, United States of America
- Arizona Respiratory Center and Department of Medicine, University of Arizona, Tucson, Arizona, United States of America
- * E-mail:
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28
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Xu L, Guo ZN, Yang Y, Xu J, Burchell SR, Tang J, Zhang J, Xu J, Zhang JH. Angiopoietin-like 4: A double-edged sword in atherosclerosis and ischemic stroke? Exp Neurol 2015; 272:61-6. [PMID: 26033474 DOI: 10.1016/j.expneurol.2015.05.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Revised: 05/21/2015] [Accepted: 05/27/2015] [Indexed: 12/27/2022]
Abstract
Ischemic stroke is one of the leading causes of death in the world, and thus is a major public health concern. Atherosclerosis, also known as atherogenesis, is a crucial risk factor for cerebral ischemia, yet how it develops remains largely unknown. It has been found, however, that angiopoietin-like protein 4 (ANGPTL4), a protein expressed in vascular endothelial cells, plays a role in the pathophysiology of atherosclerosis and may therefore be involved in ischemic stroke. ANGPTL4 activity is associated with endothelial cell integrity, inflammation, oxidative stress, and lipid metabolism. ANGPTL4 also serves as a potent inhibitor of the lipoprotein lipase, and may inhibit atherogenesis via regulating inflammatory signaling and lipid metabolism. In addition, ANGPTL4 plays a role in the regulation of oxidative stress. However, there currently exists a controversy on the role of ANGPTL4 in endothelial cells. Some studies indicate that ANGPTL4 can protect the integrity of endothelial cells, while others have shown that it can be destructive to the endothelium, thereby leading to the initiation of atherosclerosis. Thus, the effects of ANGPTL4 on development of atherosclerosis and thereby ischemic stroke, are undefined. Further research is needed to better understand ANGPTL4-mediated signaling pathways in endothelial function and to determine its potentials as therapeutic target for atherosclerosis and ischemic stroke.
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Affiliation(s)
- Liang Xu
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Zhejiang, People's Republic of China; Department of Physiology and Pharmacology, Loma Linda University School of Medicine, CA, USA
| | - Zhen-Ni Guo
- Neuroscience Center, Department of Neurology, The First Norman Bethune Hospital of Jilin University, Changchun, People's Republic of China; Department of Physiology and Pharmacology, Loma Linda University School of Medicine, CA, USA
| | - Yi Yang
- Neuroscience Center, Department of Neurology, The First Norman Bethune Hospital of Jilin University, Changchun, People's Republic of China
| | - Jun Xu
- Department of General Surgery, Changhai Hospital, The First Affiliated Hospital of Second Military Medical University, Shanghai, People's Republic of China
| | - Sherrefa R Burchell
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, CA, USA
| | - Jiping Tang
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, CA, USA
| | - Jianmin Zhang
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Zhejiang, People's Republic of China
| | - Jing Xu
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Zhejiang, People's Republic of China
| | - John H Zhang
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, CA, USA.
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29
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Tian Y, Gawlak G, Shah AS, Higginbotham K, Tian X, Kawasaki Y, Akiyama T, Sacks DB, Birukova AA. Hepatocyte growth factor-induced Asef-IQGAP1 complex controls cytoskeletal remodeling and endothelial barrier. J Biol Chem 2014; 290:4097-109. [PMID: 25492863 DOI: 10.1074/jbc.m114.620377] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Hepatocyte growth factor (HGF) attenuates agonist-induced endothelial cell (EC) permeability and increases pulmonary endothelial barrier function via Rac-dependent enhancement of the peripheral actin cytoskeleton. However, the precise mechanisms of HGF effects on the peripheral cytoskeleton are not well understood. This study evaluated a role for Rac/Cdc42-specific guanine nucleotide exchange factor Asef and the multifunctional Rac effector, IQGAP1, in the mechanism of HGF-induced EC barrier enhancement. HGF induced Asef and IQGAP1 co-localization at the cell cortical area and stimulated formation of an Asef-IQGAP1 functional protein complex. siRNA-induced knockdown of Asef or IQGAP1 attenuated HGF-induced EC barrier enhancement. Asef knockdown attenuated HGF-induced Rac activation and Rac association with IQGAP1, and it abolished both IQGAP1 accumulation at the cell cortical layer and IQGAP1 interaction with actin cytoskeletal regulators cortactin and Arp3. Asef activation state was essential for Asef interaction with IQGAP1 and protein complex accumulation at the cell periphery. In addition to the previously reported role of the IQGAP1 RasGAP-related domain in the Rac-dependent IQGAP1 activation and interaction with its targets, we show that the IQGAP1 C-terminal domain is essential for HGF-induced IQGAP1/Asef interaction and Asef-Rac-dependent activation leading to IQGAP1 interaction with Arp3 and cortactin as a positive feedback mechanism of IQGAP1 activation. These results demonstrate a novel feedback mechanism of HGF-induced endothelial barrier enhancement via Asef/IQGAP1 interactions, which regulate the level of HGF-induced Rac activation and promote cortical cytoskeletal remodeling via IQGAP1-Arp3/cortactin interactions.
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Affiliation(s)
- Yufeng Tian
- From the Section of Pulmonary and Critical Care Medicine, Department of Medicine, University of Chicago, Chicago, Illinois 60637
| | - Grzegorz Gawlak
- From the Section of Pulmonary and Critical Care Medicine, Department of Medicine, University of Chicago, Chicago, Illinois 60637
| | - Alok S Shah
- From the Section of Pulmonary and Critical Care Medicine, Department of Medicine, University of Chicago, Chicago, Illinois 60637
| | - Katherine Higginbotham
- From the Section of Pulmonary and Critical Care Medicine, Department of Medicine, University of Chicago, Chicago, Illinois 60637
| | - Xinyong Tian
- From the Section of Pulmonary and Critical Care Medicine, Department of Medicine, University of Chicago, Chicago, Illinois 60637
| | - Yoshihiro Kawasaki
- the Laboratory of Molecular and Genetic Information, Institute of Molecular and Cellular Biosciences, University of Tokyo, 113-8654 Tokyo, Japan, and
| | - Tetsu Akiyama
- the Laboratory of Molecular and Genetic Information, Institute of Molecular and Cellular Biosciences, University of Tokyo, 113-8654 Tokyo, Japan, and
| | - David B Sacks
- the Department of Laboratory Medicine, National Institutes of Health, Bethesda, Maryland 20892
| | - Anna A Birukova
- From the Section of Pulmonary and Critical Care Medicine, Department of Medicine, University of Chicago, Chicago, Illinois 60637,
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30
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Belvitch P, Adyshev D, Elangovan VR, Brown ME, Naureckas C, Rizzo AN, Siegler JH, Garcia JGN, Dudek SM. Proline-rich region of non-muscle myosin light chain kinase modulates kinase activity and endothelial cytoskeletal dynamics. Microvasc Res 2014; 95:94-102. [PMID: 25072537 DOI: 10.1016/j.mvr.2014.07.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 07/01/2014] [Accepted: 07/17/2014] [Indexed: 01/11/2023]
Abstract
Disruption of the pulmonary endothelial barrier and subsequent vascular leak is a hallmark of acute lung injury. Dynamic rearrangements in the endothelial cell (EC) peripheral membrane and underlying cytoskeleton are critical determinants of barrier function. The cytoskeletal effector protein non-muscle myosin light chain kinase (nmMLCK) and the actin-binding regulatory protein cortactin are important regulators of the endothelial barrier. In the present study we functionally characterize a proline-rich region of nmMLCK previously identified as the possible site of interaction between nmMLCK and cortactin. A mutant nmMLCK construct deficient in proline residues at the putative sites of cortactin binding (amino acids 973, 976, 1019, 1022) was generated. Co-immunoprecipitation studies in human lung EC transfected with wild-type or mutant nmMLCK demonstrated similar levels of cortactin interaction at baseline and after stimulation with the barrier-enhancing agonist, sphingosine 1-phosphate (S1P). In contrast, binding studies utilizing recombinant nmMLCK fragments containing the wild-type or proline-deficient sequence demonstrated a two-fold increase in cortactin binding (p<0.01) to the mutant construct. Immunofluorescent microscopy revealed an increased stress fiber density in ECs expressing GFP-labeled mutant nmMLCK at baseline (p=0.02) and after thrombin (p=0.01) or S1P (p=0.02) when compared to wild-type. Mutant nmMLCK demonstrated an increase in kinase activity in response to thrombin (p<0.01). Kymographic analysis demonstrated an increased EC membrane retraction distance and velocity (p<0.01) in response to the barrier disrupting agent thrombin in cells expressing the mutant vs. the wild-type nmMLCK construct. These results provide evidence that critical prolines within nmMLCK (amino acids 973, 976, 1019, 1022) regulate cytoskeletal and membrane events associated with pulmonary endothelial barrier function.
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Affiliation(s)
- Patrick Belvitch
- Division of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois Hospital and Health Science System, Chicago, IL, USA
| | - Djanybek Adyshev
- Division of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois Hospital and Health Science System, Chicago, IL, USA
| | - Venkateswaran R Elangovan
- Division of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois Hospital and Health Science System, Chicago, IL, USA
| | - Mary E Brown
- Division of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois Hospital and Health Science System, Chicago, IL, USA
| | - Caitlin Naureckas
- Division of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois Hospital and Health Science System, Chicago, IL, USA
| | - Alicia N Rizzo
- Division of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois Hospital and Health Science System, Chicago, IL, USA
| | - Jessica H Siegler
- Division of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois Hospital and Health Science System, Chicago, IL, USA
| | - Joe G N Garcia
- University of Arizona Health Sciences Center, Tucson, AZ, USA
| | - Steven M Dudek
- Division of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois Hospital and Health Science System, Chicago, IL, USA.
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31
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Rozycki M, Lodyga M, Lam J, Miranda MZ, Fátyol K, Speight P, Kapus A. The fate of the primary cilium during myofibroblast transition. Mol Biol Cell 2014; 25:643-57. [PMID: 24403605 PMCID: PMC3937090 DOI: 10.1091/mbc.e13-07-0429] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Myofibroblasts, the culprit of organ fibrosis, can originate from mesenchymal and epithelial precursors through fibroblast-myofibroblast and epithelial-myofibroblast transition (EMyT). Because certain ciliopathies are associated with fibrogenesis, we sought to explore the fate and potential role of the primary cilium during myofibroblast formation. Here we show that myofibroblast transition from either precursor results in the loss of the primary cilium. During EMyT, initial cilium growth is followed by complete deciliation. Both EMyT and cilium loss require two-hit conditions: disassembly/absence of intercellular contacts and transforming growth factor-β1 (TGFβ) exposure. Loss of E-cadherin-dependent junctions induces cilium elongation, whereas both stimuli are needed for deciliation. Accordingly, in a scratch-wounded epithelium, TGFβ provokes cilium loss exclusively along the wound edge. Increased contractility, a key myofibroblast feature, is necessary and sufficient for deciliation, since constitutively active RhoA, Rac1, or myosin triggers, and down-regulation of myosin or myocardin-related transcription factor prevents, this process. Sustained myosin phosphorylation and consequent deciliation are mediated by a Smad3-, Rac1-, and reactive oxygen species-dependent process. Transitioned myofibroblasts exhibit impaired responsiveness to platelet-derived growth factor-AA and sonic hedgehog, two cilium-associated stimuli. Although the cilium is lost during EMyT, its initial presence contributes to the transition. Thus myofibroblasts represent a unique cilium-less entity with profoundly reprogrammed cilium-related signaling.
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Affiliation(s)
- Matthew Rozycki
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, and Department of Surgery, University of Toronto, Toronto, ON M5B 1T8, Canada
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Abstract
Increased endothelial permeability and reduction of alveolar liquid clearance capacity are two leading pathogenic mechanisms of pulmonary edema, which is a major complication of acute lung injury, severe pneumonia, and acute respiratory distress syndrome, the pathologies characterized by unacceptably high rates of morbidity and mortality. Besides the success in protective ventilation strategies, no efficient pharmacological approaches exist to treat this devastating condition. Understanding of fundamental mechanisms involved in regulation of endothelial permeability is essential for development of barrier protective therapeutic strategies. Ongoing studies characterized specific barrier protective mechanisms and identified intracellular targets directly involved in regulation of endothelial permeability. Growing evidence suggests that, although each protective agonist triggers a unique pattern of signaling pathways, selected common mechanisms contributing to endothelial barrier protection may be shared by different barrier protective agents. Therefore, understanding of basic barrier protective mechanisms in pulmonary endothelium is essential for selection of optimal treatment of pulmonary edema of different etiology. This article focuses on mechanisms of lung vascular permeability, reviews major intracellular signaling cascades involved in endothelial monolayer barrier preservation and summarizes a current knowledge regarding recently identified compounds which either reduce pulmonary endothelial barrier disruption and hyperpermeability, or reverse preexisting lung vascular barrier compromise induced by pathologic insults.
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Affiliation(s)
- Konstantin G Birukov
- Lung Injury Center, Section of Pulmonary and Critical Care, Department of Medicine, University of Chicago, Chicago, Illinois, USA.
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33
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Parker JC, Hashizumi M, Kelly SV, Francis M, Mouner M, Meyer AL, Townsley MI, Wu S, Cioffi DL, Taylor MS. TRPV4 calcium entry and surface expression attenuated by inhibition of myosin light chain kinase in rat pulmonary microvascular endothelial cells. Physiol Rep 2013; 1:e00121. [PMID: 24303188 PMCID: PMC3841052 DOI: 10.1002/phy2.121] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2013] [Revised: 09/12/2013] [Accepted: 09/16/2013] [Indexed: 02/02/2023] Open
Abstract
In previous studies, blockade or gene deletion of either myosin light chain kinase (MLCK) or the mechanogated transient receptor potential vanilloid 4 (TRPV4) channel attenuated mechanical lung injury. To determine their effects on calcium entry, rat pulmonary microvascular endothelial cells (RPMVEC) were labeled with fluo-4 and calcium entry initiated with the TRPV4 agonist, 4α-phorbol 12, 13-didecanoate (4αPDD). Mean calcium transients peaked at ∼25 sec and persisted ∼500 sec. The 4αPDD response was essentially abolished in calcium-free media, or after pretreatment with the MLCK inhibitor, ML-7. ML-7 also attenuated the 4αPDD-induced inward calcium current measured directly using whole-cell patch clamp. Pretreatment with dynasore, an inhibitor of dynamin produced an initial calcium transient followed by a 4αPDD transient of unchanged peak intensity. Automated averaging of areas under the curve (AUC) of calcium transients in individual cells indicated total calcium activity with a relationship between treatment groups of ML-7 + 4αPDD < 4αPDD only < dynasore + 4αPDD. Measurement of biotinylated surface TRPV4 protein indicated a significant reduction after ML-7 pretreatment, but no significant change with dynasore treatment. RPMVEC monolayer electrical resistances were decreased by only 3% with 10 μmol/L 4αPDD and the response was dose-related. Dynasore alone produced a 29% decrease in resistance, but neither ML-7 nor dynasore affected the subsequent 4αPDD resistance response. These studies suggest that MLCK may inhibit mechanogated calcium responses through reduced surface expression of stretch activated TRPV4 channels in the plasma membrane.
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Affiliation(s)
- James C Parker
- Department of Physiology and Center for Lung Biology, College of Medicine, University of South Alabama Mobile, Alabama, 36688
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34
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Fazal F, Bijli KM, Murrill M, Leonard A, Minhajuddin M, Anwar KN, Finkelstein JN, Watterson DM, Rahman A. Critical role of non-muscle myosin light chain kinase in thrombin-induced endothelial cell inflammation and lung PMN infiltration. PLoS One 2013; 8:e59965. [PMID: 23555849 PMCID: PMC3605402 DOI: 10.1371/journal.pone.0059965] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 02/20/2013] [Indexed: 01/11/2023] Open
Abstract
The pathogenesis of acute lung injury (ALI) involves bidirectional cooperation and close interaction between inflammatory and coagulation pathways. A key molecule linking coagulation and inflammation is the procoagulant thrombin, a serine protease whose concentration is elevated in plasma and lavage fluids of patients with ALI and acute respiratory distress syndrome (ARDS). However, little is known about the mechanism by which thrombin contributes to lung inflammatory response. In this study, we developed a new mouse model that permits investigation of lung inflammation associated with intravascular coagulation. Using this mouse model and in vitro approaches, we addressed the role of non-muscle myosin light chain kinase (nmMLCK) in thrombin-induced endothelial cell (EC) inflammation and lung neutrophil (PMN) infiltration. Our in vitro experiments revealed a key role of nmMLCK in ICAM-1 expression by its ability to control nuclear translocation and transcriptional capacity of RelA/p65 in EC. When subjected to intraperitoneal thrombin challenge, wild type mice showed a marked increase in lung PMN infiltration via expression of ICAM-1. However, these responses were markedly attenuated in mice deficient in nmMLCK. These results provide mechanistic insight into lung inflammatory response associated with intravascular coagulation and identify nmMLCK as a critical target for modulation of lung inflammation.
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Affiliation(s)
- Fabeha Fazal
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, New York, United States of America.
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35
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Xiao H, Qin X, Ping D, Zuo K. Inhibition of Rho and Rac geranylgeranylation by atorvastatin is critical for preservation of endothelial junction integrity. PLoS One 2013; 8:e59233. [PMID: 23555637 PMCID: PMC3596292 DOI: 10.1371/journal.pone.0059233] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Accepted: 02/12/2013] [Indexed: 11/20/2022] Open
Abstract
Background Small GTPases (guanosine triphosphate, GTP) are involved in many critical cellular processes, including inflammation, proliferation, and migration. GTP loading and isoprenylation are two important post-translational modifications of small GTPases, and are critical for their normal function. In this study, we investigated the role of post-translational modifications of small GTPases in regulating endothelial cell inflammatory responses and junctional integrity. Methods and Results Confluent human umbilical vein endothelial cell (HUVECs ) treated with atorvastatin demonstrated significantly decreased lipopolysaccharide (LPS)-mediated IL-6 and IL-8 generation. The inhibitory effect of atorvastatin (Atorva) was attenuated by co-treatment with 100 µM mevalonate (MVA) or 10 µM geranylgeranyl pyrophosphate (GGPP), but not by 10 µM farnesyl pyrophosphate (FPP). Atorvastatin treatment of HUVECs produced a time-dependent increase in GTP loading of all Rho GTPases, and induced the translocation of small Rho GTPases from the cellular membrane to the cytosol, which was reversed by 100 µM MVA and 10 µM GGPP, but not by 10 µM FPP. Atorvastatin significantly attenuated thrombin-induced HUVECs permeability, increased VE-cadherin targeting to cell junctions, and preserved junction integrity. These effects were partially reversed by GGPP but not by FPP, indicating that geranylgeranylation of small GTPases plays a major role in regulating endothelial junction integrity. Silencing of small GTPases showed that Rho and Rac, but not Cdc42, play central role in HUVECs junction integrity. Conclusions In conclusion, our studies show that post-translational modification of small GTPases plays a vital role in regulating endothelial inflammatory response and endothelial junction integrity. Atorvastatin increased GTP loading and inhibited isoprenylation of small GTPases, accompanied by reduced inflammatory response and preserved cellular junction integrity.
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Affiliation(s)
- Hongbing Xiao
- Department of General Surgery, Shanghai Tenth People's Hospital, Tongji University, Shanghai, China.
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36
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MacGrath SM, Koleske AJ. Cortactin in cell migration and cancer at a glance. J Cell Sci 2013; 125:1621-6. [PMID: 22566665 DOI: 10.1242/jcs.093781] [Citation(s) in RCA: 139] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Stacey M MacGrath
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA.
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37
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Yao H, Duan M, Yang L, Buch S. Nonmuscle myosin light-chain kinase mediates microglial migration induced by HIV Tat: involvement of β1 integrins. FASEB J 2013; 27:1532-48. [PMID: 23292072 DOI: 10.1096/fj.12-219600] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
One of the hallmark features of HIV-associated neurological disease is increased activation and migration of microglia. HIV transactivator of transcription (Tat) is released from infected cells and has the ability to recruit microglia. The purpose of this study was to investigate molecular mechanisms by which recombinant Tat₁₋₇₂, but not heated-inactive Tat₁₋₇₂,induces migration of rat primary microglia. Using primary microglia in Boyden chambers, we demonstrated the role of nonmuscle myosin light-chain kinase (nmMYLK) in Tat₁₋₇₂ (14.4 nM)-mediated increased microglial migration (up to 171.85%). These findings were validated using microglia isolated from wild-type (WT) or nmMYLK(-/-) mice in Dunn chamber assays. Tat₁₋₇₂-mediated activation of nmMYLK resulted in "inside-out" activation of β1 integrin, followed by "outside-in" activation of c-Src, Pyk2, and Cdc42-GTP (using G-LISA in primary and nmMYLK(-/-) microglia) and, subsequently, actin polymerization (flow cytometry and Western blot assays). In vivo corroboration of these findings demonstrated decreased migration of nmMYLK(-/-) microglia (2 × 10(5) cells transplanted into corpus callosum) compared with WT microglia toward microinjected Tat₁₋₇₂ (2 μg/mouse) in hippocampus. Up-regulation of nmMYLK in microglia was also detected in sections of basal ganglia from humans with HIV-encephalitis compared with uninfected controls. nmMYLK is thus critical for eliciting microglial migration during the innate immune response.
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Affiliation(s)
- Honghong Yao
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska 68198-5880, USA
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38
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Rigor RR, Shen Q, Pivetti CD, Wu MH, Yuan SY. Myosin light chain kinase signaling in endothelial barrier dysfunction. Med Res Rev 2012; 33:911-33. [PMID: 22886693 DOI: 10.1002/med.21270] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Microvascular barrier dysfunction is a serious problem that occurs in many inflammatory conditions, including sepsis, trauma, ischemia-reperfusion injury, cardiovascular disease, and diabetes. Barrier dysfunction permits extravasation of serum components into the surrounding tissue, leading to edema formation and organ failure. The basis for microvascular barrier dysfunction is hyperpermeability at endothelial cell-cell junctions. Endothelial hyperpermeability is increased by actomyosin contractile activity in response to phosphorylation of myosin light chain by myosin light chain kinase (MLCK). MLCK-dependent endothelial hyperpermeability occurs in response to inflammatory mediators (e.g., activated neutrophils, thrombin, histamine, tumor necrosis factor alpha, etc.), through multiple cell signaling pathways and signaling molecules (e.g., Ca(++) , protein kinase C, Src kinase, nitric oxide synthase, etc.). Other signaling molecules protect against MLCK-dependent hyperpermeability (e.g., sphingosine-1-phosphate or cAMP). In addition, individual MLCK isoforms play specific roles in endothelial barrier dysfunction, suggesting that isoform-specific inhibitors could be useful for treating inflammatory disorders and preventing multiple organ failure. Because endothelial barrier dysfunction depends upon signaling through MLCK in many instances, MLCK-dependent signaling comprises multiple potential therapeutic targets for preventing edema formation and multiple organ failure. The following review is a discussion of MLCK-dependent mechanisms and cell signaling events that mediate endothelial hyperpermeability.
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Affiliation(s)
- Robert R Rigor
- Department of Surgery, University of California at Davis School of Medicine, Sacramento, California, USA
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39
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Zhao J, Wei J, Mialki R, Zou C, Mallampalli RK, Zhao Y. Extracellular signal-regulated kinase (ERK) regulates cortactin ubiquitination and degradation in lung epithelial cells. J Biol Chem 2012; 287:19105-14. [PMID: 22514278 DOI: 10.1074/jbc.m112.339507] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Cortactin, an actin-binding protein, is essential for cell growth and motility. We have shown that cortactin is regulated by reversible phosphorylation, but little is known regarding cortactin protein stability. Here, we show that lipopolysaccharide (LPS)-induced cortactin degradation is mediated by extracellular regulated signal kinase (ERK). LPS induces cortactin serine phosphorylation, ubiquitination, and degradation in mouse lung epithelia, an effect abrogated by ERK inhibition. Serine phosphorylation sites mutant, cortactin(S405A/S418A), enhances its protein stability. Cortactin is polyubiquitinated and degraded within the proteasome, whereas a cortactin(K79R) mutant exhibited proteolytic stability during cyclohexamide (CHX) or LPS treatment. The E3 ligase subunit β-Trcp interacts with cortactin, and its overexpression reduced cortactin protein levels, an effect attenuated by ERK inhibition. Overexpression of β-Trcp was sufficient to reduce the protective effects of exogenous cortactin on epithelial cell barrier integrity, an effect not observed after expression of a cortactin(K79R) mutant. These results provide evidence that LPS modulation of cortactin stability is coordinately regulated by stress kinases and the ubiquitin-proteasomal network.
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Affiliation(s)
- Jing Zhao
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
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40
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Bhuwania R, Cornfine S, Fang Z, Krüger M, Luna EJ, Linder S. Supervillin couples myosin-dependent contractility to podosomes and enables their turnover. J Cell Sci 2012; 125:2300-14. [PMID: 22344260 DOI: 10.1242/jcs.100032] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Podosomes are actin-rich adhesion and invasion structures. Especially in macrophages, podosomes exist in two subpopulations, large precursors at the cell periphery and smaller podosomes (successors) in the cell interior. To date, the mechanisms that differentially regulate these subpopulations are largely unknown. Here, we show that the membrane-associated protein supervillin localizes preferentially to successor podosomes and becomes enriched at precursors immediately before their dissolution. Consistently, podosome numbers are inversely correlated with supervillin protein levels. Using deletion constructs, we find that the myosin II regulatory N-terminus of supervillin [SV(1-174)] is crucial for these effects. Phosphorylated myosin light chain (pMLC) localizes at supervillin-positive podosomes, and time-lapse analyses show that enrichment of GFP-supervillin at podosomes coincides with their coupling to contractile myosin-IIA-positive cables. We also show that supervillin binds only to activated myosin IIA, and a dysregulated N-terminal construct [SV(1-830)] enhances pMLC levels at podosomes. Thus, preferential recruitment of supervillin to podosome subpopulations might both require and induce actomyosin contractility. Using siRNA and pharmacological inhibition, we demonstrate that supervillin and myosin IIA cooperate to regulate podosome lifetime, podosomal matrix degradation and cell polarization. In sum, we show here that podosome subpopulations differ in their molecular composition and identify supervillin, in cooperation with myosin IIA, as a crucial factor in the regulation of podosome turnover and function.
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Affiliation(s)
- Ridhirama Bhuwania
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Eppendorf, Hamburg, Germany
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41
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Kelley LC, Hayes KE, Ammer AG, Martin KH, Weed SA. Revisiting the ERK/Src cortactin switch. Commun Integr Biol 2011; 4:205-7. [PMID: 21655441 DOI: 10.4161/cib.4.2.14420] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Accepted: 12/07/2010] [Indexed: 11/19/2022] Open
Abstract
The filamentous (F)-actin regulatory protein cortactin plays an important role in tumor cell movement and invasion by promoting and stabilizing actin related protein (Arp)2/3-mediated actin networks necessary for plasma membrane protrusion. Cortactin is a substrate for ERK1/2 and Src family kinases, with previous in vitro findings demonstrating ERK1/2 phosphorylation of cortactin as a positive and Src phosphorylation as a negative regulatory event in promoting Arp2/3 activation through neuronal Wiskott Aldrich Syndrome protein (N-WASp). Evidence for this regulatory cortactin "switch" in cells has been hampered due to the lack of phosphorylation-specific antibodies that recognize ERK1/2-phosphorylated cortactin. Our findings with phosphorylation-specific antibodies against these ERK1/2 sites (pS405 and pS418) indicate that cortactin can be co-phosphorylated at 405/418 and tyrosine residues targeted by Src family tyrosine kinases. These results indicate that the ERK/Src cortactin switch is not the sole mechanism by which ERK1/2 and tyrosine phosphorylation events regulate cortactin function in cell systems.
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Affiliation(s)
- Laura C Kelley
- Department of Neurobiology and Anatomy; Program in Cancer Cell Biology; Mary Babb Randolph Cancer Center; West Virginia University, Morgantown, WV USA
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42
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Cross LJM, Matthay MA. Biomarkers in acute lung injury: insights into the pathogenesis of acute lung injury. Crit Care Clin 2011; 27:355-77. [PMID: 21440206 PMCID: PMC3073651 DOI: 10.1016/j.ccc.2010.12.005] [Citation(s) in RCA: 173] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Studies of potential biomarkers of acute lung injury (ALI) have provided information relating to the pathophysiology of the mechanisms of lung injury and repair. The utility of biomarkers remains solely among research tools to investigate lung injury and repair mechanisms. Because of lack of sensitivity and specificity, they cannot be used in decision making in patients with ALI or acute respiratory distress syndrome. The authors reviewed known biomarkers in context of their major biologic activity. The continued interest in identifying and studying biomarkers is relevant, as it provides information regarding the mechanisms involved in lung injury and repair and how this may be helpful in identifying and designing future therapeutic targets and strategies and possibly identifying a sensitive and specific biomarker.
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Affiliation(s)
- L J Mark Cross
- Centre for Infection and Immunity, The Queen's University of Belfast, Room 01/014, Health Sciences Building, 97 Lisburn Road, Belfast, BT9 7BL, N Ireland
| | - Michael A Matthay
- Cardiovascular Research Institute, University of California, San Francisco, 505 Parnassus Ave, M-917, San Francisco, CA 94143-0624, California, USA
- Department of Medicine, Division of Pulmonary and Critical Care, and Department of Anaesthesia, University of California, San Francisco, 505 Parnassus Avenue, San Francisco, CA 94143-2202, California, USA
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43
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Kirkbride KC, Sung BH, Sinha S, Weaver AM. Cortactin: a multifunctional regulator of cellular invasiveness. Cell Adh Migr 2011; 5:187-98. [PMID: 21258212 DOI: 10.4161/cam.5.2.14773] [Citation(s) in RCA: 136] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Branched actin assembly is critical for a variety of cellular processes that underlie cell motility and invasion, including cellular protrusion formation and membrane trafficking. Activation of branched actin assembly occurs at various subcellular locations via site-specific activation of distinct WASp family proteins and the Arp2/3 complex. A key branched actin regulator that promotes cell motility and links signaling, cytoskeletal and membrane trafficking proteins is the Src kinase substrate and Arp2/3 binding protein cortactin. Due to its frequent overexpression in advanced, invasive cancers and its general role in regulating branched actin assembly at multiple cellular locations, cortactin has been the subject of intense study. Recent studies suggest that cortactin has a complex role in cellular migration and invasion, promoting both on-site actin polymerization and modulation of autocrine secretion. Diverse cellular activities may derive from the interaction of cortactin with site-specific binding partners.
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Affiliation(s)
- Kellye C Kirkbride
- Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN, USA
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44
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Barfod ET, Moore AL, Van de Graaf BG, Lidofsky SD. Myosin light chain kinase and Src control membrane dynamics in volume recovery from cell swelling. Mol Biol Cell 2011; 22:634-50. [PMID: 21209319 PMCID: PMC3046060 DOI: 10.1091/mbc.e10-06-0514] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
MLCK resolves membrane blebbing induced by osmotic cell swelling. Cell swelling also stimulates the formation of a Src–MLCK complex, which with cortactin and dynamin forms actin-based structures at the base of the cell to facilitate membrane retrieval for volume recovery. The expansion of the plasma membrane, which occurs during osmotic swelling of epithelia, must be retrieved for volume recovery, but the mechanisms are unknown. Here we have identified myosin light chain kinase (MLCK) as a regulator of membrane internalization in response to osmotic swelling in a model liver cell line. On hypotonic exposure, we found that there was time-dependent phosphorylation of the MLCK substrate myosin II regulatory light chain. At the sides of the cell, MLCK and myosin II localized to swelling-induced membrane blebs with actin just before retraction, and MLCK inhibition led to persistent blebbing and attenuated cell volume recovery. At the base of the cell, MLCK also localized to dynamic actin-coated rings and patches upon swelling, which were associated with uptake of the membrane marker FM4-64X, consistent with sites of membrane internalization. Hypotonic exposure evoked increased biochemical association of the cell volume regulator Src with MLCK and with the endocytosis regulators cortactin and dynamin, which colocalized within these structures. Inhibition of either Src or MLCK led to altered patch and ring lifetimes, consistent with the concept that Src and MLCK form a swelling-induced protein complex that regulates volume recovery through membrane turnover and compensatory endocytosis under osmotic stress.
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Affiliation(s)
- Elisabeth T Barfod
- Department of Pharmacology, University of Vermont, Burlington, VT 05405 Department of Medicine, University of Vermont, Burlington, VT 05405, USA
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Yuan JXJ, Garcia JG, West JB, Hales CA, Rich S, Archer SL. Genomics of Acute Lung Injury and Vascular Barrier Dysfunction. TEXTBOOK OF PULMONARY VASCULAR DISEASE 2011. [PMCID: PMC7122529 DOI: 10.1007/978-0-387-87429-6_63] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Acute lung injury (ALI) is a devastating syndrome of diffuse alveolar damage that develops via a variety of local and systemic insults such as sepsis, trauma, pneumonia, and aspiration. It is interestingly to note that only a subset of individuals exposed to potential ALI-inciting insults develop the disorder and the severity of the disease varies from complete resolution to death. In addition, ALI susceptibility and severity are also affected by ethnicity as evidenced by the higher mortality rates observed in African-American ALI patients compared with other ethnic groups in the USA. Moreover, marked differences in strain-specific ALI responses to inflammatory and injurious agents are observed in preclinical animal models. Together, these observations strongly indicate genetic components to be involved in the pathogenesis of ALI. The identification of genes contributing to ALI would potentially provide a better understanding of ALI pathobiology, yield novel biomarkers, identify individuals or populations at risk, and prove useful for the development of novel and individualized therapies. Genome-wide searches in animal models have identified a number of quantitative trait loci that associate with ALI susceptibility. In this chapter, we utilize a systems biology approach combining cellular signaling pathway analysis with population- based association studies to review established and suspected candidate genes that contribute to dysfunction of endothelial cell barrier integrity and ALI susceptibility.
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Affiliation(s)
- Jason X. -J. Yuan
- Departments of Medicine, COMRB Rm. 3131 (MC 719), University of Illinois at Chicago, 909 South Wolcott Avenue, Chicago, 60612 Illinois USA
| | - Joe G.N. Garcia
- 310 Admin.Office Building (MC 672), University of Illinois at Chicago, 1737 W. Polk Street, Suite 310, Chicago, 60612 Illinois USA
| | - John B. West
- Department of Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, 92093-0623 California USA
| | - Charles A. Hales
- Dept. Pulmonary & Critical Care Medicine, Massachusetts General Hospital, 55 Fruit Street, Boston, 02114 Massachusetts USA
| | - Stuart Rich
- Department of Medicine, University of Chicago Medical Center, 5841 S. Maryland Ave., Chicago, 60637 Illinois USA
| | - Stephen L. Archer
- Department of Medicine, University of Chicago School of Medicine, 5841 S. Maryland Ave., Chicago, 60637 Illinois USA
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Acute Lung Injury: The Injured Lung Endothelium, Therapeutic Strategies for Barrier Protection, and Vascular Biomarkers. TEXTBOOK OF PULMONARY VASCULAR DISEASE 2010. [PMCID: PMC7120335 DOI: 10.1007/978-0-387-87429-6_12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Dudek SM, Chiang ET, Camp SM, Guo Y, Zhao J, Brown ME, Singleton PA, Wang L, Desai A, Arce FT, Lal R, Van Eyk JE, Imam SZ, Garcia JGN. Abl tyrosine kinase phosphorylates nonmuscle Myosin light chain kinase to regulate endothelial barrier function. Mol Biol Cell 2010; 21:4042-56. [PMID: 20861316 PMCID: PMC2982111 DOI: 10.1091/mbc.e09-10-0876] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
This study identified multiple novel c-Abl–mediated nmMLCK phosphorylation sites by mass spectroscopy and examined their influence on nmMLCK function and human lung endothelial barrier regulation. The data indicate an essential role for Abl kinase in vascular barrier regulation via phosphorylation of nmMLCK and the actin-binding protein cortactin. Nonmuscle myosin light chain kinase (nmMLCK), a multi-functional cytoskeletal protein critical to vascular homeostasis, is highly regulated by tyrosine phosphorylation. We identified multiple novel c-Abl–mediated nmMLCK phosphorylation sites by mass spectroscopy analysis (including Y231, Y464, Y556, Y846) and examined their influence on nmMLCK function and human lung endothelial cell (EC) barrier regulation. Tyrosine phosphorylation of nmMLCK increased kinase activity, reversed nmMLCK-mediated inhibition of Arp2/3-mediated actin polymerization, and enhanced binding to the critical actin-binding phosphotyrosine protein, cortactin. EC challenge with sphingosine 1-phosphate (S1P), a potent barrier-enhancing agonist, resulted in c-Abl and phosphorylated nmMLCK recruitment into caveolin-enriched microdomains, rapid increases in Abl kinase activity, and spatial targeting of c-Abl to barrier-promoting cortical actin structures. Conversely, reduced c-Abl expression in EC (siRNA) markedly attenuated S1P-mediated cortical actin formation, reduced the EC modulus of elasticity (assessed by atomic force microscopy), reduced nmMLCK and cortactin tyrosine phosphorylation, and attenuated S1P-mediated barrier enhancement. These studies indicate an essential role for Abl kinase in vascular barrier regulation via posttranslational modification of nmMLCK and strongly support c-Abl-cortactin-nmMLCK interaction as a novel determinant of cortical actin-based cytoskeletal rearrangement critical to S1P-mediated EC barrier enhancement.
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Affiliation(s)
- Steven M Dudek
- Institute for Personalized Respiratory Medicine, Section of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois at Chicago, Chicago, IL 60612, USA
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Brown M, Adyshev D, Bindokas V, Moitra J, Garcia JGN, Dudek SM. Quantitative distribution and colocalization of non-muscle myosin light chain kinase isoforms and cortactin in human lung endothelium. Microvasc Res 2010; 80:75-88. [PMID: 20053363 DOI: 10.1016/j.mvr.2009.12.010] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2009] [Revised: 12/08/2009] [Accepted: 12/25/2009] [Indexed: 10/20/2022]
Abstract
Vascular barrier regulation is intimately linked to alterations in the distribution and configuration of the endothelial cell (EC) cytoskeleton in response to angiogenic and edemagenic agonists. Critical actin cytoskeletal rearrangement includes spatially directed increases in myosin light chain (MLC) phosphorylation, catalyzed by Ca(2+)/calmodulin-dependent non-muscle myosin light chain kinase variants (nmMLCK1- and -2), as well as association of nmMLCK with the actin-binding protein, cortactin. As these associations have proven difficult to quantify in a spatially specific manner, we now describe the utility of intensity correlation image analysis and the intensity correlation quotient (ICQ) to quantify colocalization in fixed and live cell imaging assays in human pulmonary artery EC. From baseline ICQ values averaging 0.216 reflecting colocalization of cortactin-DsRed with EGFP-nmMLCK fusion proteins in resting EC, thrombin-induced EC contraction significantly reduced cortactin-DsRed-EGFP-nmMLCK colocalization (nmMLCK1: ICQ=0.118; nmMLCK2: ICQ=0.091) whereas the potent EC barrier-protective agonist, sphingosine 1-phosphate (S1P), significantly increased nmMLCK-cortactin colocalization within lamellipodia (nmMLCK1: ICQ=0.275; nmMLCK2: ICQ=0.334). Over-expression of a cortactin-DsRed mutant fusion protein lacking the SH3 domain, known to be essential for cortactin-nmMLCK association, reduced baseline and S1P-mediated live cell colocalization with each nmMLCK variant (nmMLCK1: ICQ=0.160; nmMLCK2: ICQ=0.157). Similarly, expression of a truncated EGFP-nmMLCK2 mutant lacking cortactin- and actin-binding domains, markedly reduced basal localization in lamellipodia and abolished colocalization with cortactin-DsRed in lamellipodia after S1P (ICQ=-0.148). These data provide insights into the molecular basis for vascular barrier-regulatory cytoskeletal responses and support the utility of sophisticated imaging analyses and methodological assessment to quantify the critical nmMLCK and cortactin interaction during vascular barrier regulation.
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Affiliation(s)
- Mary Brown
- Department of Medicine, Pritzker School of Medicine, University of Chicago, Chicago, IL 60637, USA
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Ren G, Crampton MS, Yap AS. Cortactin: Coordinating adhesion and the actin cytoskeleton at cellular protrusions. ACTA ACUST UNITED AC 2009; 66:865-73. [PMID: 19437513 DOI: 10.1002/cm.20380] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
It has long been recognized that adhesion receptors cooperate with the cytoskeleton during morphogenesis, tissue remodeling and homeostasis. But how this occurs is less well-understood. A host of cytoskeletal regulators have been reported to have functional and biochemical linkage with adhesion receptors. The challenge remains to find functionally-coherent patterns within this increasingly large corpus of molecular information. In this review we discuss one approach, to identify distinctive functional modules that contribute to different adhesive processes. We illustrate this by considering Arp2/3-driven surface protrusion, which is utilized at both integrin-based cell-matrix adhesions and cadherin-based cell-cell adhesions. We further argue that regulatory proteins, such as cortactin, serve to coordinate the molecular components of this protrusive apparatus into a cohesive module.
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Affiliation(s)
- Gang Ren
- Institute for Molecular Bioscience, Division of Molecular Cell Biology, The University of Queensland, St. Lucia, Brisbane, Queensland, Australia 4072
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