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Mintoo M, Rajagopalan V, O'Bryan JP. Intersectin - many facets of a scaffold protein. Biochem Soc Trans 2024; 52:1-13. [PMID: 38174740 DOI: 10.1042/bst20211241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 12/04/2023] [Accepted: 12/18/2023] [Indexed: 01/05/2024]
Abstract
Intersectin (ITSN) is a multi-domain scaffold protein with a diverse array of functions including regulation of endocytosis, vesicle transport, and activation of various signal transduction pathways. There are two ITSN genes located on chromosomes 21 and 2 encoding for proteins ITSN1 and ITSN2, respectively. Each ITSN gene encodes two major isoforms, ITSN-Long (ITSN-L) and ITSN-Short (ITSN-S), due to alternative splicing. ITSN1 and 2, collectively referred to as ITSN, are implicated in many physiological and pathological processes, such as neuronal maintenance, actin cytoskeletal rearrangement, and tumor progression. ITSN is mis-regulated in many tumors, such as breast, lung, neuroblastomas, and gliomas. Altered expression of ITSN is also found in several neurodegenerative diseases, such as Down Syndrome and Alzheimer's disease. This review summarizes recent studies on ITSN and provides an overview of the function of this important family of scaffold proteins in various biological processes.
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Affiliation(s)
- Mubashir Mintoo
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, U.S.A
| | - Vinodh Rajagopalan
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, U.S.A
| | - John P O'Bryan
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, U.S.A
- Ralph H. Johnson VA Medical Center, Charleston, SC 29401, U.S.A
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Chompre G, Martinez-Orengo N, Cruz M, Porter JT, Noel RJ. TGFβRI antagonist inhibits HIV-1 Nef-induced CC chemokine family ligand 2 (CCL2) in the brain and prevents spatial learning impairment. J Neuroinflammation 2019; 16:262. [PMID: 31829243 PMCID: PMC6905066 DOI: 10.1186/s12974-019-1664-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 11/27/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND HIV-1-associated neurocognitive disorders (HAND) progression is related to continued inflammation despite undetectable viral loads and may be caused by early viral proteins expressed by latently infected cells. Astrocytes represent an HIV reservoir in the brain where the early viral neurotoxin negative factor (Nef) is produced. We previously demonstrated that astrocytic expression of Nef in the hippocampus of rats causes inflammation, macrophage infiltration, and memory impairment. Since these processes are affected by TGFβ signaling pathways, and TGFβ-1 is found at higher levels in the central nervous system of HIV-1+ individuals and is released by astrocytes, we hypothesized a role for TGFβ-1 in our model of Nef neurotoxicity. METHODS To test this hypothesis, we compared cytokine gene expression by cultured astrocytes expressing Nef or green fluorescent protein. To determine the role of Nef and a TGFβRI inhibitor on memory and learning, we infused astrocytes expressing Nef into the hippocampus of rats and then treated them daily with an oral dose of SD208 (10 mg/kg) or placebo for 7 days. During this time, locomotor activity was recorded in an open field and spatial learning tested in the novel location recognition paradigm. Postmortem tissue analyses of inflammatory and signaling molecules were conducted using immunohistochemistry and immunofluorescence. RESULTS TGFβ-1 was induced in cultures expressing Nef at 24 h followed by CCL2 induction which was prevented by blocking TGFβRI with SD208 (competitive inhibitor). Interestingly, Nef seems to change the TGFβRI localization as suggested by the distribution of the immunoreactivity. Nef caused a deficit in spatial learning that was recovered upon co-administration of SD208. Brain tissue from Nef-treated rats given SD208 showed reduced CCL2, phospho-SMAD2, cluster of differentiation 163 (CD163), and GFAP immunoreactivity compared to the placebo group. CONCLUSIONS Consistent with our previous findings, rats treated with Nef showed deficits in spatial learning and memory in the novel location recognition task. In contrast, rats treated with Nef + SD208 showed better spatial learning suggesting that Nef disrupts memory formation in a TGFβ-1-dependent manner. The TGFβRI inhibitor further reduced the induction of inflammation by Nef which was concomitant with decreased TGFβ signaling. Our findings suggest that TGFβ-1 signaling is an intriguing target to reduce neuroHIV.
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Affiliation(s)
- Gladys Chompre
- Biology Department, Pontifical Catholic University of Puerto Rico, Ponce, Puerto Rico
| | - Neysha Martinez-Orengo
- Department of Basic Sciences, Ponce Health Sciences University-Ponce Medical School, Ponce Research Institute, P.O. Box 7004, Ponce, PR, 00731, USA
| | - Myrella Cruz
- Department of Basic Sciences, Ponce Health Sciences University-Ponce Medical School, Ponce Research Institute, P.O. Box 7004, Ponce, PR, 00731, USA
| | - James T Porter
- Department of Basic Sciences, Ponce Health Sciences University-Ponce Medical School, Ponce Research Institute, P.O. Box 7004, Ponce, PR, 00731, USA
| | - Richard J Noel
- Department of Basic Sciences, Ponce Health Sciences University-Ponce Medical School, Ponce Research Institute, P.O. Box 7004, Ponce, PR, 00731, USA.
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Shah TG, Predescu D, Predescu S. Mesenchymal stem cells-derived extracellular vesicles in acute respiratory distress syndrome: a review of current literature and potential future treatment options. Clin Transl Med 2019; 8:25. [PMID: 31512000 PMCID: PMC6739436 DOI: 10.1186/s40169-019-0242-9] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 09/06/2019] [Indexed: 02/08/2023] Open
Abstract
Acute respiratory distress syndrome (ARDS) is a life-threatening inflammatory lung condition associated with significant morbidity and mortality. Unfortunately, the current treatment for this disease is mainly supportive. Mesenchymal stem cells (MSCs) due to their immunomodulatory properties are increasingly being studied for the treatment of ARDS and have shown promise in multiple animal studies. The therapeutic effects of MSCs are exerted in part in a paracrine manner by releasing extracellular vesicles (EVs), rather than local engraftment. MSC-derived EVs are emerging as potential alternatives to MSC therapy in ARDS. In this review, we will introduce EVs and briefly discuss current data on EVs and MSCs in ARDS. We will discuss current literature on the role of MSC-derived EVs in pathogenesis and treatment of ARDS and their potential as a treatment strategy in the future.
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Affiliation(s)
- Trushil G Shah
- Department of Internal Medicine, Pulmonary, Critical Care and Sleep Medicine, Rush University Medical Center, 1750 W Harrison St. 1535 JS, Chicago, IL, 60612, USA.,Division of Pulmonary and Critical Care Medicine, University of Texas Southwestern, Dallas, TX, USA
| | - Dan Predescu
- Department of Internal Medicine, Pulmonary, Critical Care and Sleep Medicine, Rush University Medical Center, 1750 W Harrison St. 1535 JS, Chicago, IL, 60612, USA
| | - Sanda Predescu
- Department of Internal Medicine, Pulmonary, Critical Care and Sleep Medicine, Rush University Medical Center, 1750 W Harrison St. 1535 JS, Chicago, IL, 60612, USA.
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Carman BL, Predescu DN, Machado R, Predescu SA. Plexiform Arteriopathy in Rodent Models of Pulmonary Arterial Hypertension. THE AMERICAN JOURNAL OF PATHOLOGY 2019; 189:1133-1144. [PMID: 30926336 DOI: 10.1016/j.ajpath.2019.02.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 02/12/2019] [Indexed: 12/11/2022]
Abstract
As time progresses, our understanding of disease pathology is propelled forward by technological advancements. Much of the advancements that aid in understanding disease mechanics are based on animal studies. Unfortunately, animal models often fail to recapitulate the entirety of the human disease. This is especially true with animal models used to study pulmonary arterial hypertension (PAH), a disease with two distinct phases. The first phase is defined by nonspecific medial and adventitial thickening of the pulmonary artery and is commonly reproduced in animal models, including the classic models (ie, hypoxia-induced pulmonary hypertension and monocrotaline lung injury model). However, many animal models, including the classic models, fail to capture the progressive, or second, phase of PAH. This is a stage defined by plexogenic arteriopathy, resulting in obliteration and occlusion of the small- to mid-sized pulmonary vessels. Each of these two phases results in severe pulmonary hypertension that directly leads to right ventricular hypertrophy, decompensated right-sided heart failure, and death. Fortunately, newly developed animal models have begun to address the second, more severe, side of PAH and aid in our ability to develop new therapeutics. Moreover, p38 mitogen-activated protein kinase activation emerges as a central molecular mediator of plexiform lesions in both experimental models and human disease. Therefore, this review will focus on plexiform arteriopathy in experimental animal models of PAH.
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Affiliation(s)
- Brandon L Carman
- Division of Pulmonary Critical Care and Sleep Medicine, Department of Internal Medicine, Rush Medical College, Chicago, Illinois
| | - Dan N Predescu
- Division of Pulmonary Critical Care and Sleep Medicine, Department of Internal Medicine, Rush Medical College, Chicago, Illinois
| | - Roberto Machado
- Division of Pulmonary, Critical Care, Sleep, and Occupational Medicine, Department of Medicine, Indiana University, Indianapolis, Indiana
| | - Sanda A Predescu
- Division of Pulmonary Critical Care and Sleep Medicine, Department of Internal Medicine, Rush Medical College, Chicago, Illinois.
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Letsiou E, Bauer N. Endothelial Extracellular Vesicles in Pulmonary Function and Disease. CURRENT TOPICS IN MEMBRANES 2018; 82:197-256. [PMID: 30360780 DOI: 10.1016/bs.ctm.2018.09.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The pulmonary vascular endothelium is involved in the pathogenesis of acute and chronic lung diseases. Endothelial cell (EC)-derived products such as extracellular vesicles (EVs) serve as EC messengers that mediate inflammatory as well as cytoprotective effects. EC-EVs are a broad term, which encompasses exosomes and microvesicles of endothelial origin. EVs are comprised of lipids, nucleic acids, and proteins that reflect not only the cellular origin but also the stimulus that triggered their biogenesis and secretion. This chapter presents an overview of the biology of EC-EVs and summarizes key findings regarding their characteristics, components, and functions. The role of EC-EVs is specifically delineated in pulmonary diseases characterized by endothelial dysfunction, including pulmonary hypertension, acute respiratory distress syndrome and associated conditions, chronic obstructive pulmonary disease, and obstructive sleep apnea.
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Affiliation(s)
- Eleftheria Letsiou
- Division of Pulmonary Inflammation, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Natalie Bauer
- Department of Pharmacology & Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, AL, United States.
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Predescu D, Qin S, Patel M, Bardita C, Bhalli R, Predescu S. Epsin15 Homology Domains: Role in the Pathogenesis of Pulmonary Arterial Hypertension. Front Physiol 2018; 9:1393. [PMID: 30333761 PMCID: PMC6176378 DOI: 10.3389/fphys.2018.01393] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 09/13/2018] [Indexed: 12/24/2022] Open
Abstract
Intersectin-1s (ITSN) deficiency and expression of a biologically active ITSN fragment, result of granzyme B cleavage under inflammatory conditions associated with pulmonary arterial hypertension (PAH), are characteristics of lung tissue of human and animal models of PAH. Recently, we have shown that this ITSN fragment comprising two Epsin15 homology domains (EHITSN) triggers endothelial cell (EC) proliferation and the plexiform arteriopathy in PAH. Limited evidence also indicates that the EH domains of endocytic proteins such as ITSN, upregulate compensatory endocytic pathways in cells with impaired vesicular trafficking. Thus, we sought to investigate whether the EHITSN may be involved in this compensatory mechanism for improving the EC endocytic dysfunction induced by ITSN deficiency and possibly contribute to PAH pathogenesis. We used stably-transfected human pulmonary artery ECs expressing the Myc-EHITSN (ECEH-ITSN) and ITSN knockout heterozygous mice (K0ITSN+/-) transduced with the Myc-EHITSN, in conjunction with functional assays: the biotin assay for caveolae internalization and 8 nm gold (Au)- and dinitrophenylated (DNP)-albumin perfusion of murine lung microvasculature. Pulmonary artery ECs of PAH patients (ECPAH), ITSN knockdown ECs (ECKD-ITSN), the monocrotaline (MCT)-induced mouse and rat models of PAH, as well as untreated animals, served as controls. ELISA via streptavidin-HRP or anti-DNP antibody (Ab), applied on ECs and lung lysates indicated greater than 30% increase in biotin internalization in ECEH-ITSN compared to ECCtrl. Despite their endocytic deficiency, ECPAH internalized biotin similar to ECCtrl which is twofold higher compared to ECKD-ITSN. Moreover, the lung microvascular bed of Myc-EHITSN-transduced mice and MCT-treated animals showed greater than twofold increase in DNP-BSA transendothelial transport, all compared to untreated controls. Electron microscopy (EM) revealed the increased occurrence of non-conventional endocytic/transcytotic structures (i.e., caveolae clusters, tubulo-vesicular and enlarged endocytic structures, membranous rings), usually underrepresented. Most of these structures were labeled by Au-BSA, consistent with their involvement in the transendothelial transport. Furthermore, ITSN deficiency and EHITSN expression alter the subcellular localization of the EH-binding protein 1 (EHBP1) and cortical actin organization, altogether supporting the increase occurrence/trafficking of the alternative endocytic structures. Thus, the EHITSN by shifting the physiological vesicular (caveolae) transport toward the alternative endocytic pathways is a significant contributor to the dysfunctional molecular phenotype of ECPAH.
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Affiliation(s)
- Dan Predescu
- Division of Pulmonary Medicine, Critical Care and Sleep Medicine, Department of Internal Medicine, Rush Medical College, Rush University, Chicago, IL, United States
| | - Shanshan Qin
- Division of Pulmonary Medicine, Critical Care and Sleep Medicine, Department of Internal Medicine, Rush Medical College, Rush University, Chicago, IL, United States
| | - Monal Patel
- Division of Pulmonary Medicine, Critical Care and Sleep Medicine, Department of Internal Medicine, Rush Medical College, Rush University, Chicago, IL, United States
| | - Cristina Bardita
- Division of Pulmonary Medicine, Critical Care and Sleep Medicine, Department of Internal Medicine, Rush Medical College, Rush University, Chicago, IL, United States
| | - Rabia Bhalli
- Division of Pulmonary Medicine, Critical Care and Sleep Medicine, Department of Internal Medicine, Rush Medical College, Rush University, Chicago, IL, United States
| | - Sanda Predescu
- Division of Pulmonary Medicine, Critical Care and Sleep Medicine, Department of Internal Medicine, Rush Medical College, Rush University, Chicago, IL, United States
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Shah T, Qin S, Vashi M, Predescu DN, Jeganathan N, Bardita C, Ganesh B, diBartolo S, Fogg LF, Balk RA, Predescu SA. Alk5/Runx1 signaling mediated by extracellular vesicles promotes vascular repair in acute respiratory distress syndrome. Clin Transl Med 2018; 7:19. [PMID: 29931538 PMCID: PMC6013417 DOI: 10.1186/s40169-018-0197-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 06/12/2018] [Indexed: 12/20/2022] Open
Abstract
Background Pulmonary endothelial cells’ (ECs) injury and apoptotic death are necessary and sufficient for the pathogenesis of the acute respiratory distress syndrome (ARDS), regardless of epithelial damage. Interaction of dysfunctional ECs with circulatory extracellular vesicles (EVs) holds therapeutic promise in ARDS. However, the presence in the blood of long-term ARDS survivors of EVs with a distinct phenotype compared to the EVs of non-surviving patients is not reported. With a multidisciplinary translational approach, we studied EVs from the blood of 33 patients with moderate-to-severe ARDS. Results The EVs were isolated from the blood of ARDS and control subjects. Immunoblotting and magnetic beads immunoisolation complemented by standardized flow cytometry and nanoparticles tracking analyses identified in the ARDS patients a subset of EVs with mesenchymal stem cell (MSC) origin (CD73+CD105+Cd34−CD45−). These EVs have 4.7-fold greater counts compared to controls and comprise the transforming growth factor-beta receptor I (TβRI)/Alk5 and the Runx1 transcription factor. Time course analyses showed that the expression pattern of two Runx1 isoforms is critical for ARDS outcome: the p52 isoform shows a continuous expression, while the p66 is short-lived. A high ratio Runx1p66/p52 provided a survival advantage, regardless of age, sex, disease severity or length of stay in the intensive care unit. Moreover, the Runx1p66 isoform is transiently expressed by cultured human bone marrow-derived MSCs, it is released in the EVs recoverable from the conditioned media and stimulates the proliferation of lipopolysaccharide (LPS)-treated ECs. The findings are consistent with a causal effect of Runx1p66 expression on EC proliferation. Furthermore, morphological and functional assays showed that the EVs bearing the Runx1p66 enhanced junctional integrity of LPS-injured ECs and decreased lung histological severity in the LPS-treated mice. Conclusions The expression pattern of Runx1 isoforms might be a reliable circulatory biomarker of ARDS activity and a novel determinant of the molecular mechanism for lung vascular/tissue repair and recovery after severe injury. Electronic supplementary material The online version of this article (10.1186/s40169-018-0197-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Trushil Shah
- Pulmonary and Critical Care Medicine, UTSouthwestern Medical Center, Dallas, TX, USA
| | - Shanshan Qin
- Department of Internal Medicine, Pulmonary, Critical Care and Sleep Medicine, Rush University Medical Center, 1750W Harrison St. 1535 JS, Chicago, IL, 60612, USA
| | - Mona Vashi
- Department of Internal Medicine, Pulmonary, Critical Care and Sleep Medicine, Rush University Medical Center, 1750W Harrison St. 1535 JS, Chicago, IL, 60612, USA
| | - Dan N Predescu
- Department of Internal Medicine, Pulmonary, Critical Care and Sleep Medicine, Rush University Medical Center, 1750W Harrison St. 1535 JS, Chicago, IL, 60612, USA
| | - Niranjan Jeganathan
- Department of Internal Medicine, Pulmonary, Critical Care and Sleep Medicine, Rush University Medical Center, 1750W Harrison St. 1535 JS, Chicago, IL, 60612, USA
| | - Cristina Bardita
- Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | | | - Salvatore diBartolo
- Department of Internal Medicine, Pulmonary, Critical Care and Sleep Medicine, Rush University Medical Center, 1750W Harrison St. 1535 JS, Chicago, IL, 60612, USA
| | - Louis F Fogg
- College of Nursing, Rush Medical College, Chicago, IL, USA
| | - Robert A Balk
- Department of Internal Medicine, Pulmonary, Critical Care and Sleep Medicine, Rush University Medical Center, 1750W Harrison St. 1535 JS, Chicago, IL, 60612, USA
| | - Sanda A Predescu
- Department of Internal Medicine, Pulmonary, Critical Care and Sleep Medicine, Rush University Medical Center, 1750W Harrison St. 1535 JS, Chicago, IL, 60612, USA.
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Dergai O, Dergai M, Rynditch A. Ubiquitin-ligase AIP4 controls differential ubiquitination and stability of isoforms of the scaffold protein ITSN1. FEBS Lett 2018; 592:2259-2267. [PMID: 29851086 DOI: 10.1002/1873-3468.13118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 05/12/2018] [Accepted: 05/17/2018] [Indexed: 11/07/2022]
Abstract
At present, the role of ubiquitination of cargoes internalized from the plasma membrane is better understood than the consequences of ubiquitination of proteins comprising the endocytic machinery. Here, we show that the E3 ubiquitin ligase AIP4/ITCH contributes to the differential ubiquitination of isoforms of the endocytic scaffold protein intersectin1 (ITSN1). The major isoform ITSN1-s is monoubiquitinated, whereas the minor one, ITSN1-22a undergoes a combination of mono- and oligoubiquitination. The monoubiquitination is required for ITSN1-s stability, whereas the oligoubiquitination of ITSN1-22a causes its proteasomal degradation. This explains the observed low abundance of the minor isoform in cells. Thus, different modes of ubiquitination regulated by AIP4 have opposite effects on ITSN1 isoform stability.
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Affiliation(s)
- Oleksandr Dergai
- Institute of Molecular Biology and Genetics, The National Academy of Science of Ukraine, Kyiv, Ukraine
| | - Mykola Dergai
- Institute of Molecular Biology and Genetics, The National Academy of Science of Ukraine, Kyiv, Ukraine
| | - Alla Rynditch
- Institute of Molecular Biology and Genetics, The National Academy of Science of Ukraine, Kyiv, Ukraine
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Jeganathan N, Predescu D, Predescu S. Intersectin-1s deficiency in pulmonary pathogenesis. Respir Res 2017; 18:168. [PMID: 28874189 PMCID: PMC5585975 DOI: 10.1186/s12931-017-0652-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 08/28/2017] [Indexed: 02/07/2023] Open
Abstract
Intersectin-1s (ITSN-1s), a multidomain adaptor protein, plays a vital role in endocytosis, cytoskeleton rearrangement and cell signaling. Recent studies have demonstrated that deficiency of ITSN-1s is a crucial early event in pulmonary pathogenesis. In lung cancer, ITSN-1s deficiency impairs Eps8 ubiquitination and favors Eps8-mSos1 interaction which activates Rac1 leading to enhanced lung cancer cell proliferation, migration and metastasis. Restoring ITSN-1s deficiency in lung cancer cells facilitates cytoskeleton changes favoring mesenchymal to epithelial transformation and impairs lung cancer progression. ITSN-1s deficiency in acute lung injury leads to impaired endocytosis which leads to ubiquitination and degradation of growth factor receptors such as Alk5. This deficiency is counterbalanced by microparticles which, via paracrine effects, transfer Alk5/TGFβRII complex to non-apoptotic cells. In the presence of ITSN-1s deficiency, Alk5-restored cells signal via Erk1/2 MAPK pathway leading to restoration and repair of lung architecture. In inflammatory conditions such as pulmonary artery hypertension, ITSN-1s full length protein is cleaved by granzyme B into EHITSN and SH3A-EITSN fragments. The EHITSN fragment leads to pulmonary cell proliferation via activation of p38 MAPK and Elk-1/c-Fos signaling. In vivo, ITSN-1s deficient mice transduced with EHITSN plasmid develop pulmonary vascular obliteration and plexiform lesions consistent with pathological findings seen in severe pulmonary arterial hypertension. These novel findings have significantly contributed to understanding the mechanisms and pathogenesis involved in pulmonary pathology. As demonstrated in these studies, genetically modified ITSN-1s expression mouse models will be a valuable tool to further advance our understanding of pulmonary pathology and lead to novel targets for treating these conditions.
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Affiliation(s)
| | - Dan Predescu
- Department of Pharmacology and Division of Pulmonary and Critical Care Medicine, Rush University, 1750 W. Harrison Street, 1415 Jelke, Chicago, IL, 60612, USA
| | - Sanda Predescu
- Department of Pharmacology and Division of Pulmonary and Critical Care Medicine, Rush University Medical Center and Rush Medical College, 1750 W. Harrison Street, 1535 Jelke, Chicago, IL, 60612, USA
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Herrero-Garcia E, O'Bryan JP. Intersectin scaffold proteins and their role in cell signaling and endocytosis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1864:23-30. [PMID: 27746143 DOI: 10.1016/j.bbamcr.2016.10.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 10/08/2016] [Indexed: 11/29/2022]
Abstract
Intersectins (ITSNs) are a family of multi-domain proteins involved in regulation of diverse cellular pathways. These scaffold proteins are well known for regulating endocytosis but also play important roles in cell signaling pathways including kinase regulation and Ras activation. ITSNs participate in several human cancers, such as neuroblastomas and glioblastomas, while their downregulation is associated with lung injury. Alterations in ITSN expression have been found in neurodegenerative diseases such as Down Syndrome and Alzheimer's disease. Binding proteins for ITSNs include endocytic regulatory factors, cytoskeleton related proteins (i.e. actin or dynamin), signaling proteins as well as herpes virus proteins. This review will summarize recent studies on ITSNs, highlighting the importance of these scaffold proteins in the aforementioned processes.
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Affiliation(s)
- Erika Herrero-Garcia
- Department of Pharmacology, University of Illinois at Chicago, Chicago, IL 60612, USA; Jesse Brown VA Medical Center, Chicago, IL 60612, USA
| | - John P O'Bryan
- Department of Pharmacology, University of Illinois at Chicago, Chicago, IL 60612, USA; Jesse Brown VA Medical Center, Chicago, IL 60612, USA.
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Jeganathan N, Predescu D, Zhang J, Sha F, Bardita C, Patel M, Wood S, Borgia JA, Balk RA, Predescu S. Rac1-mediated cytoskeleton rearrangements induced by intersectin-1s deficiency promotes lung cancer cell proliferation, migration and metastasis. Mol Cancer 2016; 15:59. [PMID: 27629044 PMCID: PMC5024437 DOI: 10.1186/s12943-016-0543-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 09/06/2016] [Indexed: 12/21/2022] Open
Abstract
Background The mechanisms involved in lung cancer (LC) progression are poorly understood making discovery of successful therapies difficult. Adaptor proteins play a crucial role in cancer as they link cell surface receptors to specific intracellular pathways. Intersectin-1s (ITSN-1s) is an important multidomain adaptor protein implicated in the pathophysiology of numerous pulmonary diseases. To date, the role of ITSN-1s in LC has not been studied. Methods Human LC cells, human LC tissue and A549 LC cells stable transfected with myc-ITSN-1s construct (A549 + ITSN-1s) were used in correlation with biochemical, molecular biology and morphological studies. In addition scratch assay with time lapse microscopy and in vivo xenograft tumor and mouse metastasis assays were performed. Results ITSN-1s, a prevalent protein of lung tissue, is significantly downregulated in human LC cells and LC tissue. Restoring ITSN-1s protein level decreases LC cell proliferation and clonogenic potential. In vivo studies indicate that immunodeficient mice injected with A549 + ITSN-1s cells develop less and smaller metastatic tumors compared to mice injected with A549 cells. Our studies also show that restoring ITSN-1s protein level increases the interaction between Cbl E3 ubiquitin ligase and Eps8 resulting in enhanced ubiquitination of the Eps8 oncoprotein. Subsequently, downstream unproductive assembly of the Eps8-mSos1 complex leads to impaired activation of the small GTPase Rac1. Impaired Rac1 activation mediated by ITSN-1s reorganizes the cytoskeleton (increased thick actin bundles and focal adhesion (FA) complexes as well as collapse of the vimentin filament network) in favor of decreased LC cell migration and metastasis. Conclusion ITSN-1s induced Eps8 ubiquitination and impaired Eps8-mSos1 complex formation, leading to impaired activation of Rac1, is a novel signaling mechanism crucial for abolishing the progression and metastatic potential of LC cells. Electronic supplementary material The online version of this article (doi:10.1186/s12943-016-0543-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Niranjan Jeganathan
- Division of Pulmonary and Critical Care Medicine, Rush University Medical Center and Rush Medical College, 1750 W. Harrison Street, 299 Jelke South Center, Chicago, IL, 60612, USA.
| | - Dan Predescu
- Department of Pharmacology and Division of Pulmonary and Critical Care Medicine, Rush University, 1750 W. Harrison Street, 1415 Jelke, Chicago, IL, 60612, USA
| | - Jin Zhang
- Department of Pharmacology, Rush University, 1750 W. Harrison Street, 1533 Jelke, Chicago, IL, 60612, USA
| | - Fei Sha
- Department of Pharmacology, Rush University, 1750 W. Harrison Street, 1533 Jelke, Chicago, IL, 60612, USA
| | - Cristina Bardita
- Department of Pharmacology, Rush University, 1750 W. Harrison Street, 1537 Jelke, Chicago, IL, 60612, USA
| | - Monal Patel
- Department of Pharmacology, Rush University, 1750 W. Harrison Street, 1533 Jelke, Chicago, IL, 60612, USA
| | - Stephen Wood
- Department of Immunology, Rush University, 1735 W. Harrison Street, 663 Cohn, Chicago, IL, 60612, USA
| | - Jeffrey A Borgia
- Department of Biochemistry, Rush University, 1750 W. Harrison Street, 1415 Jelke, Chicago, IL, 60612, USA
| | - Robert A Balk
- Division of Pulmonary and Critical Care Medicine, Rush University Medical Center and Rush Medical College, 1750 W. Harrison Street, 293 Jelke, Chicago, IL, 60612, USA
| | - Sanda Predescu
- Department of Pharmacology and Division of Pulmonary and Critical Care Medicine, Rush University Medical Center and Rush Medical College, 1750 W. Harrison Street, 1535 Jelke, Chicago, IL, 60612, USA
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Predescu S, Bardita C, Predescu D. New insights into the functions of intersectin-1s. Commun Integr Biol 2015; 8:e1034400. [PMID: 26479042 PMCID: PMC4594419 DOI: 10.1080/19420889.2015.1034400] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 03/20/2015] [Indexed: 11/27/2022] Open
Abstract
Intersectin-1s (ITSN) is a ubiquitously expressed multifunctional protein known as a scaffold and regulator of the general endocytic machinery as well as a critical integrator of cellular signaling pathways. We showed recently that ITSN deficiency triggers a transforming growth factor β (TGFβ)/Alk5 signaling switch, from the canonical Smad 2/3 to the Erk1/2 MAPK pathway; moreover, endocytic impairment induced by ITSN deficiency enhances Alk5 ubiquitination and degradation and elicits TGFβ-paracrine effects mediated by circulating microparticles, leading to endothelial cell survival and increased proliferation. The studies expand our understanding of how ITSN facilitates cross-regulation of signaling pathways and provide insights into the involvement of ITSN deficiency in human disease.
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Affiliation(s)
- Sanda Predescu
- Departments of Pharmacology and Critical Care Medicine; Rush University Medical Center ; Chicago, IL USA
| | - Cristina Bardita
- Departments of Pharmacology and Critical Care Medicine; Rush University Medical Center ; Chicago, IL USA ; Department of Internal Medicine; Rush University Medical Center ; Chicago, IL USA
| | - Dan Predescu
- Departments of Pharmacology and Critical Care Medicine; Rush University Medical Center ; Chicago, IL USA
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