1
|
Akkoc Y, Dalci K, Karakas HE, Erbil-Bilir S, Yalav O, Sakman G, Celik F, Arikan S, Zeybek U, Ergin M, Akkiz H, Dilege E, Dengjel J, Dogan-Ekici AI, Gozuacik D. Tumor-derived CTF1 (cardiotrophin 1) is a critical mediator of stroma-assisted and autophagy-dependent breast cancer cell migration, invasion and metastasis. Autophagy 2023; 19:306-323. [PMID: 35722965 PMCID: PMC9809961 DOI: 10.1080/15548627.2022.2090693] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Macroautophagy/autophagy is an evolutionarily conserved cellular stress response mechanism. Autophagy induction in the tumor microenvironment (stroma) has been shown to support tumor metabolism. However, cancer cell-derived secreted factors that initiate communication with surrounding cells and stimulate autophagy in the tumor microenvironment are not fully documented. We identified CTF1/CT-1 (cardiotrophin 1) as an activator of autophagy in fibroblasts and breast cancer-derived carcinoma-associated fibroblasts (CAFs). We showed that CTF1 stimulated phosphorylation and nuclear translocation of STAT3, initiating transcriptional activation of key autophagy proteins. Additionally, following CTF1 treatment, AMPK and ULK1 activation was observed. We provided evidence that autophagy was important for CTF1-dependent ACTA2/α-SMA accumulation, stress fiber formation and fibroblast activation. Moreover, promotion of breast cancer cell migration and invasion by activated fibroblasts depended on CTF1 and autophagy. Analysis of the expression levels of CTF1 in patient-derived breast cancer samples led us to establish a correlation between CTF1 expression and autophagy in the tumor stroma. In line with our in vitro data on cancer migration and invasion, higher levels of CTF1 expression in breast tumors was significantly associated with lymph node metastasis in patients. Therefore, CTF1 is an important mediator of tumor-stroma interactions, fibroblast activation and cancer metastasis, and autophagy plays a key role in all these cancer-related events.Abbreviations: ACTA2/α-SMA: actin, alpha 2, smooth muscle CAFs: cancer- or carcinoma-associated fibroblasts CNT Ab.: control antibody CNTF: ciliary neurotrophic factor CTF1: cardiotrophin 1 CTF1 Neut. Ab.: CTF1-specific neutralizing antibody GFP-LC3 MEF: GFP-fused to MAP1LC3 protein transgenic MEF LIF: leukemia inhibitory factor IL6: interleukin 6 MEFs: mouse embryonic fibroblasts MEF-WT: wild-type MEFs OSM: oncostatin M TGFB/TGFβ: transforming growth factor beta.
Collapse
Affiliation(s)
- Yunus Akkoc
- Koç University Research Center for Translational Medicine (KUTTAM), Istanbul, Turkey,Department of Biotechnology, Sabanci University Nanotechnology Research and Application Center (SUNUM), Istanbul, Turkey
| | - Kubilay Dalci
- Faculty of Medicine, Department of General Surgery, Çukurova University, Adana, Turkey
| | - Hacer Ezgi Karakas
- Department of Biotechnology, Sabanci University Nanotechnology Research and Application Center (SUNUM), Istanbul, Turkey
| | - Secil Erbil-Bilir
- Department of Biotechnology, Sabanci University Nanotechnology Research and Application Center (SUNUM), Istanbul, Turkey
| | - Orcun Yalav
- Faculty of Medicine, Department of General Surgery, Çukurova University, Adana, Turkey
| | - Gurhan Sakman
- Faculty of Medicine, Department of General Surgery, Çukurova University, Adana, Turkey
| | - Faruk Celik
- Department of Molecular Medicine, Istanbul University Aziz Sancar Institute of Experimental Medicine, Istanbul, Turkey
| | - Soykan Arikan
- Department of General Surgery, Ministry of Health Samatya Training and Research Hospital, Istanbul, Turkey
| | - Umit Zeybek
- Department of Molecular Medicine, Istanbul University Aziz Sancar Institute of Experimental Medicine, Istanbul, Turkey
| | - Melek Ergin
- Faculty of Medicine, Department of Pathology, Çukurova University, Adana, Turkey
| | - Hikmet Akkiz
- Faculty of Medicine, Department of Gastroenterology, Çukurova University, Adana, Turkey
| | - Ece Dilege
- Koç University Hospital, Department of General Surgery, Koç University Medical School, Istanbul, Turkey,School of Medicine, Koç University, Istanbul, Turkey
| | - Joern Dengjel
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - A. Isin Dogan-Ekici
- School of Medicine, Department of Pathology, Acibadem Mehmet Ali Aydınlar University, Istanbul, Turkey
| | - Devrim Gozuacik
- Koç University Research Center for Translational Medicine (KUTTAM), Istanbul, Turkey,Department of Biotechnology, Sabanci University Nanotechnology Research and Application Center (SUNUM), Istanbul, Turkey,School of Medicine, Koç University, Istanbul, Turkey,CONTACT Devrim Gozuacik Koç University School of Medicine, Research Center for Translational Medicine (KUTTAM), Istanbul, Turkey; Department of Biotechnology, Sabanci University Nanotechnology Research and Application Center (SUNUM), Istanbul, Turkey; School of Medicine, Koç University, Istanbul, Turkey
| |
Collapse
|
2
|
Clerici SP, Peppelenbosch M, Fuhler G, Consonni SR, Ferreira-Halder CV. Colorectal Cancer Cell-Derived Small Extracellular Vesicles Educate Human Fibroblasts to Stimulate Migratory Capacity. Front Cell Dev Biol 2021; 9:696373. [PMID: 34336845 PMCID: PMC8320664 DOI: 10.3389/fcell.2021.696373] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 06/14/2021] [Indexed: 12/24/2022] Open
Abstract
Colorectal cancer (CRC) is in the top 10 cancers most prevalent worldwide, affecting equally men and women. Current research on tumor-derived extracellular vesicles (EVs) suggests that these small extracellular vesicles (sEVs) play an important role in mediating cell-to-cell communication and thus potentially affecting cancer progression via multiple pathways. In the present study, we hypothesized that sEVs derived from different CRC cell lines differ in their ability to reprogram normal human fibroblasts through a process called tumor education. The sEVs derived from CRC cell lines (HT29 and HCT116) were isolated by a combination of ultrafiltration and polymeric precipitation, followed by characterization based on morphology, size, and the presence or absence of EV and non-EV markers. It was observed that the HT29 cells displayed a higher concentration of sEVs compared with HCT116 cells. For the first time, we demonstrated that HT29-derived sEVs were positive for low-molecular-weight protein tyrosine phosphatase (Lmwptp). CRC cell-derived sEVs were uptake by human fibroblasts, stimulating migratory ability via Rho-Fak signaling in co-incubated human fibroblasts. Another important finding showed that HT29 cell-derived sEVs are much more efficient in activating human fibroblasts to cancer-associated fibroblasts (CAFs). Indeed, the sEVs produced by the HT29 cells that are less responsive to a cytotoxic agent display higher efficiency in educating normal human fibroblasts by providing them advantages such as activation and migratory ability. In other words, these sEVs have an influence on the CRC microenvironment, in part, due to fibroblasts reprogramming.
Collapse
Affiliation(s)
- Stefano Piatto Clerici
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas, Campinas, Brazil
| | - Maikel Peppelenbosch
- Department of Gastroenterology and Hepatology, Erasmus University Medical Center Rotterdam, Rotterdam, Netherlands
| | - Gwenny Fuhler
- Department of Gastroenterology and Hepatology, Erasmus University Medical Center Rotterdam, Rotterdam, Netherlands
| | - Sílvio Roberto Consonni
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas, Campinas, Brazil
| | | |
Collapse
|
3
|
Mushtaq U, Bashir M, Nabi S, Khanday FA. Epidermal growth factor receptor and integrins meet redox signaling through P66shc and Rac1. Cytokine 2021; 146:155625. [PMID: 34157521 DOI: 10.1016/j.cyto.2021.155625] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 05/23/2021] [Accepted: 06/08/2021] [Indexed: 12/24/2022]
Abstract
This review examines the concerted role of Epidermal Growth Factor Receptor (EGFR) and integrins in regulating Reactive oxygen species (ROS) production through different signaling pathways. ROS as such are not always deleterious to the cells but they also act as signaling molecules, that regulates numerous indespensible physiological fuctions of life. Many adaptor proteins, particularly Shc and Grb2, are involved in mediating the downstream signaling pathways stimulated by EGFR and integrins. Integrin-induced activation of EGFR and subsequent tyrosine phosphorylation of a class of acceptor sites on EGFR leads to alignment and tyrosine phosphorylation of Shc, PLCγ, the p85 subunit of PI-3 K, and Cbl, followed by activation of the downstream targets Erk and Akt/PKB. Functional interactions between these receptors result in the activation of Rac1 via these adaptor proteins, thereby leading to Reactive Oxygen Species. Both GF and integrin activation can produce oxidants independently, however synergistically there is increased ROS generation, suggesting a mutual cooperation between integrins and GFRs for redox signalling. The ROS produced further promotes feed-forward stimulation of redox signaling events such as MAPK activation and gene expression. This relationship has not been reviewed previously. The literature presented here can have multiple implications, ranging from looking at synergistic effects of integrin and EGFR mediated signaling mechanisms of different proteins to possible therapeutic interventions operated by these two receptors. Furthermore, such mutual redox regulation of crosstalk between EGFR and integrins not only add to the established models of pathological oxidative stress, but also can impart new avenues and opportunities for targeted antioxidant based therapeutics.
Collapse
Affiliation(s)
- Umar Mushtaq
- Department of Biotechnology, University of Kashmir, Srinagar, JK 190006, India; Department of Biotechnology, Central University of Kashmir, Ganderbal, JK 191201, India
| | - Muneesa Bashir
- Department of Biotechnology, University of Kashmir, Srinagar, JK 190006, India; Department of Higher Education, Government of Jammu & Kashmir, 190001, India
| | - Sumaiya Nabi
- Department of Biochemistry, University of Kashmir, Srinagar, JK 190006, India
| | - Firdous A Khanday
- Department of Biotechnology, University of Kashmir, Srinagar, JK 190006, India.
| |
Collapse
|
4
|
Faria AVS, Fonseca EMB, Cordeiro HG, Clerici SP, Ferreira-Halder CV. Low molecular weight protein tyrosine phosphatase as signaling hub of cancer hallmarks. Cell Mol Life Sci 2021; 78:1263-1273. [PMID: 33052434 PMCID: PMC11073135 DOI: 10.1007/s00018-020-03657-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 08/21/2020] [Accepted: 09/22/2020] [Indexed: 12/12/2022]
Abstract
In the past decade, significant progress has been made in understanding the role of protein tyrosine phosphatase as a positive regulator of tumor progression. In this scenario, our group was one of the first to report the involvement of the low molecular weight protein tyrosine phosphatase (LMWPTP or ACP1) in the process of resistance and migration of tumor cells. Later, we and others demonstrated a positive correlation between the amount of this enzyme in human tumors and the poor prognosis. With this information in mind, we asked if LMWPTP contribution to metastasis, would it have an action beyond the primary tumor site. We know that the amount of this enzyme in the tumor cell correlates positively with the ability of cancer cells to interact with platelets, an indication that this enzyme is also important for the survival of these cells in the bloodstream. Here, we discuss several molecular aspects that support the idea of LMWPTP as a signaling hub of cancer hallmarks. Chemical and genetic modulation of LMWPTP proved to shut down signaling pathways associated with cancer aggressiveness. Therefore, advances in the development of LMWPTP inhibitors have great applicability in human diseases such as cancer.
Collapse
Affiliation(s)
- Alessandra V S Faria
- Department of Biochemistry and Tissue Biology, University of Campinas, Campinas, São Paulo, Brazil
- Department of Gastroenterology and Hepatology, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Emanuella Maria Barreto Fonseca
- Department of Biochemistry and Tissue Biology, University of Campinas, Campinas, São Paulo, Brazil
- Federal Institute of São Paulo, São Roque, São Paulo, Brazil
| | - Helon Guimarães Cordeiro
- Department of Biochemistry and Tissue Biology, University of Campinas, Campinas, São Paulo, Brazil
| | - Stefano Piatto Clerici
- Department of Biochemistry and Tissue Biology, University of Campinas, Campinas, São Paulo, Brazil
| | | |
Collapse
|
5
|
Pardella E, Pranzini E, Leo A, Taddei ML, Paoli P, Raugei G. Oncogenic Tyrosine Phosphatases: Novel Therapeutic Targets for Melanoma Treatment. Cancers (Basel) 2020; 12:E2799. [PMID: 33003469 PMCID: PMC7599540 DOI: 10.3390/cancers12102799] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 09/24/2020] [Accepted: 09/28/2020] [Indexed: 12/12/2022] Open
Abstract
Despite a large number of therapeutic options available, malignant melanoma remains a highly fatal disease, especially in its metastatic forms. The oncogenic role of protein tyrosine phosphatases (PTPs) is becoming increasingly clear, paving the way for novel antitumor treatments based on their inhibition. In this review, we present the oncogenic PTPs contributing to melanoma progression and we provide, where available, a description of new inhibitory strategies designed against these enzymes and possibly useful in melanoma treatment. Considering the relevance of the immune infiltrate in supporting melanoma progression, we also focus on the role of PTPs in modulating immune cell activity, identifying interesting therapeutic options that may support the currently applied immunomodulating approaches. Collectively, this information highlights the value of going further in the development of new strategies targeting oncogenic PTPs to improve the efficacy of melanoma treatment.
Collapse
Affiliation(s)
- Elisa Pardella
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio” University of Florence, Viale Morgagni 50, 50134 Florence, Italy; (E.P.); (E.P.); (A.L.); (G.R.)
| | - Erica Pranzini
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio” University of Florence, Viale Morgagni 50, 50134 Florence, Italy; (E.P.); (E.P.); (A.L.); (G.R.)
| | - Angela Leo
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio” University of Florence, Viale Morgagni 50, 50134 Florence, Italy; (E.P.); (E.P.); (A.L.); (G.R.)
| | - Maria Letizia Taddei
- Department of Experimental and Clinical Medicine, University of Florence, Viale Morgagni 50, 50134 Florence, Italy;
| | - Paolo Paoli
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio” University of Florence, Viale Morgagni 50, 50134 Florence, Italy; (E.P.); (E.P.); (A.L.); (G.R.)
| | - Giovanni Raugei
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio” University of Florence, Viale Morgagni 50, 50134 Florence, Italy; (E.P.); (E.P.); (A.L.); (G.R.)
| |
Collapse
|
6
|
Knock GA. NADPH oxidase in the vasculature: Expression, regulation and signalling pathways; role in normal cardiovascular physiology and its dysregulation in hypertension. Free Radic Biol Med 2019; 145:385-427. [PMID: 31585207 DOI: 10.1016/j.freeradbiomed.2019.09.029] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 08/29/2019] [Accepted: 09/23/2019] [Indexed: 02/06/2023]
Abstract
The last 20-25 years have seen an explosion of interest in the role of NADPH oxidase (NOX) in cardiovascular function and disease. In vascular smooth muscle and endothelium, NOX generates reactive oxygen species (ROS) that act as second messengers, contributing to the control of normal vascular function. NOX activity is altered in response to a variety of stimuli, including G-protein coupled receptor agonists, growth-factors, perfusion pressure, flow and hypoxia. NOX-derived ROS are involved in smooth muscle constriction, endothelium-dependent relaxation and smooth muscle growth, proliferation and migration, thus contributing to the fine-tuning of blood flow, arterial wall thickness and vascular resistance. Through reversible oxidative modification of target proteins, ROS regulate the activity of protein tyrosine phosphatases, kinases, G proteins, ion channels, cytoskeletal proteins and transcription factors. There is now considerable, but somewhat contradictory evidence that NOX contributes to the pathogenesis of hypertension through oxidative stress. Specific NOX isoforms have been implicated in endothelial dysfunction, hyper-contractility and vascular remodelling in various animal models of hypertension, pulmonary hypertension and pulmonary arterial hypertension, but also have potential protective effects, particularly NOX4. This review explores the multiplicity of NOX function in the healthy vasculature and the evidence for and against targeting NOX for antihypertensive therapy.
Collapse
Affiliation(s)
- Greg A Knock
- Dpt. of Inflammation Biology, School of Immunology & Microbial Sciences, Faculty of Life Sciences & Medicine, King's College London, UK.
| |
Collapse
|
7
|
Ma S, Fu A, Lim S, Chiew GGY, Luo KQ. MnSOD mediates shear stress-promoted tumor cell migration and adhesion. Free Radic Biol Med 2018; 129:46-58. [PMID: 30193891 DOI: 10.1016/j.freeradbiomed.2018.09.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 08/07/2018] [Accepted: 09/03/2018] [Indexed: 12/27/2022]
Abstract
Circulation of cancer cells in the bloodstream is a vital step for distant metastasis, during which cancer cells are exposed to hemodynamic shear stress (SS). The actions of SS on tumor cells are complicated and not fully understood. We previously reported that fluidic SS was able to promote migration of breast cancer cells by elevating the cellular ROS level. In this study, we further investigated the mechanisms regulating SS-promoted cell migration and identified the role of MnSOD in the related pathway. We found that SS could enhance tumor cell adhesion to extracellular matrix and endothelial monolayer, and MnSOD also regulated this process. Briefly, SS stimulates the generation of mitochondrial superoxide in tumor cells. MnSOD then converts superoxide into hydrogen peroxide, which activates ERK1/2 to promote tumor cell migration and activates FAK to promote tumor cell adhesion. Combining our previous and present studies, we present experimental evidence on the pro-metastatic effects of hemodynamic SS and reveal the underlying mechanism. Our findings provide new insights into the nature of cancer metastasis and the understanding of tumor cell responses to external stresses and have valuable implications for cancer therapy development.
Collapse
Affiliation(s)
- Shijun Ma
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore
| | - Afu Fu
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore
| | - Sierin Lim
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore
| | | | - Kathy Qian Luo
- Faculty of Health Sciences, University of Macau, Taipa, Macau, China.
| |
Collapse
|
8
|
Meeusen B, Janssens V. Tumor suppressive protein phosphatases in human cancer: Emerging targets for therapeutic intervention and tumor stratification. Int J Biochem Cell Biol 2017; 96:98-134. [PMID: 29031806 DOI: 10.1016/j.biocel.2017.10.002] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Revised: 10/04/2017] [Accepted: 10/05/2017] [Indexed: 02/06/2023]
Abstract
Aberrant protein phosphorylation is one of the hallmarks of cancer cells, and in many cases a prerequisite to sustain tumor development and progression. Like protein kinases, protein phosphatases are key regulators of cell signaling. However, their contribution to aberrant signaling in cancer cells is overall less well appreciated, and therefore, their clinical potential remains largely unexploited. In this review, we provide an overview of tumor suppressive protein phosphatases in human cancer. Along their mechanisms of inactivation in defined cancer contexts, we give an overview of their functional roles in diverse signaling pathways that contribute to their tumor suppressive abilities. Finally, we discuss their emerging roles as predictive or prognostic markers, their potential as synthetic lethality targets, and the current feasibility of their reactivation with pharmacologic compounds as promising new cancer therapies. We conclude that their inclusion in clinical practice has obvious potential to significantly improve therapeutic outcome in various ways, and should now definitely be pushed forward.
Collapse
Affiliation(s)
- Bob Meeusen
- Laboratory of Protein Phosphorylation & Proteomics, Dept. of Cellular & Molecular Medicine, Faculty of Medicine, KU Leuven & Leuven Cancer Institute (LKI), KU Leuven, Belgium
| | - Veerle Janssens
- Laboratory of Protein Phosphorylation & Proteomics, Dept. of Cellular & Molecular Medicine, Faculty of Medicine, KU Leuven & Leuven Cancer Institute (LKI), KU Leuven, Belgium.
| |
Collapse
|
9
|
Kusuyama J, Bandow K, Ohnishi T, Hisadome M, Shima K, Semba I, Matsuguchi T. Osteopontin inhibits osteoblast responsiveness through the down-regulation of focal adhesion kinase mediated by the induction of low-molecular weight protein tyrosine phosphatase. Mol Biol Cell 2017; 28:1326-1336. [PMID: 28331074 PMCID: PMC5426847 DOI: 10.1091/mbc.e16-10-0716] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 03/06/2017] [Accepted: 03/13/2017] [Indexed: 12/23/2022] Open
Abstract
Osteopontin (OPN), a major marker of osteogenic differentiation, suppresses osteoblast responses to mechanical stress and cytokines, including HGF and PDGF. These OPN-induced effects are mediated through focal adhesion kinase inactivation by the induction of low–molecular weight protein tyrosine phosphatase. Osteopontin (OPN) is an osteogenic marker protein. Osteoblast functions are affected by inflammatory cytokines and pathological conditions. OPN is highly expressed in bone lesions such as those in rheumatoid arthritis. However, local regulatory effects of OPN on osteoblasts remain ambiguous. Here we examined how OPN influences osteoblast responses to mechanical stress and growth factors. Expression of NO synthase 1 (Nos1) and Nos2 was increased by low-intensity pulsed ultrasound (LIPUS) in MC3T3-E1 cells and primary osteoblasts. The increase of Nos1/2 expression was abrogated by both exogenous OPN overexpression and recombinant OPN treatment, whereas it was promoted by OPN-specific siRNA and OPN antibody. Moreover, LIPUS-induced phosphorylation of focal adhesion kinase (FAK), a crucial regulator of mechanoresponses, was down-regulated by OPN treatments. OPN also attenuated hepatocyte growth factor–induced vitamin D receptor (Vdr) expression and platelet-derived growth factor–induced cell mobility through the repression of FAK activity. Of note, the expression of low–molecular weight protein tyrosine phosphatase (LMW-PTP), a FAK phosphatase, was increased in both OPN-treated and differentiated osteoblasts. CD44 was a specific OPN receptor for LWW-PTP induction. Consistently, the suppressive influence of OPN on osteoblast responsiveness was abrogated by LMW-PTP knockdown. Taken together, these results reveal novel functions of OPN in osteoblast physiology.
Collapse
Affiliation(s)
- Joji Kusuyama
- Department of Oral Biochemistry, Field of Developmental Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan
| | - Kenjiro Bandow
- Department of Oral Biology and Tissue Engineering, Meikai University School of Dentistry, Sakato 350-0283, Japan
| | - Tomokazu Ohnishi
- Department of Oral Biochemistry, Field of Developmental Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan
| | - Mitsuhiro Hisadome
- Department of Oral Biochemistry, Field of Developmental Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan.,Department of Dermatology, Field of Advanced Therapeutics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan
| | - Kaori Shima
- Department of Oral Pathology, Field of Oncology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan
| | - Ichiro Semba
- Department of Oral Pathology, Field of Oncology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan
| | - Tetsuya Matsuguchi
- Department of Oral Biochemistry, Field of Developmental Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan
| |
Collapse
|
10
|
Hammer A, Diakonova M. Prolactin-induced PAK1 tyrosyl phosphorylation promotes FAK dephosphorylation, breast cancer cell motility, invasion and metastasis. BMC Cell Biol 2016; 17:31. [PMID: 27542844 PMCID: PMC4992334 DOI: 10.1186/s12860-016-0109-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 08/04/2016] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND The serine/threonine kinase PAK1 is an important regulator of cell motility. Both PAK1 and the hormone/cytokine prolactin (PRL) have been implicated in breast cancer cell motility, however, the exact mechanisms guiding PRL/PAK1 signaling in breast cancer cells have not been fully elucidated. Our lab has previously demonstrated that PRL-activated tyrosine kinase JAK2 phosphorylates PAK1 on tyrosines 153, 201, and 285, and that tyrosyl phosphorylated PAK1 (pTyr-PAK1) augments migration and invasion of breast cancer cells. RESULTS Here we further investigate the mechanisms by which pTyr-PAK1 enhances breast cancer cell motility in response to PRL. We demonstrate a distinct reduction in PRL-induced FAK auto-phosphorylation in T47D and TMX2-28 breast cancer cells overexpressing wild-type PAK1 (PAK1 WT) when compared to cells overexpressing either GFP or phospho-tyrosine-deficient mutant PAK1 (PAK1 Y3F). Furthermore, pTyr-PAK1 phosphorylates MEK1 on Ser298 resulting in subsequent ERK1/2 activation. PRL-induced FAK auto-phosphorylation is rescued in PAK1 WT cells by inhibiting tyrosine phosphatases and tyrosine phosphatase inhibition abrogates cell motility and invasion in response to PRL. siRNA-mediated knockdown of the tyrosine phosphatase PTP-PEST rescues FAK auto-phosphorylation in PAK1 WT cells and reduces both cell motility and invasion. Finally, we provide evidence that PRL-induced pTyr-PAK1 stimulates tumor cell metastasis in vivo. CONCLUSION These data provide insight into the mechanisms guiding PRL-mediated breast cancer cell motility and invasion and highlight a significant role for pTyr-PAK1 in breast cancer metastasis.
Collapse
Affiliation(s)
- Alan Hammer
- Department of Biological Sciences, University of Toledo, 2801 W. Bancroft Street, Toledo, 43606-3390, OH, USA
| | - Maria Diakonova
- Department of Biological Sciences, University of Toledo, 2801 W. Bancroft Street, Toledo, 43606-3390, OH, USA.
| |
Collapse
|
11
|
Caselli A, Paoli P, Santi A, Mugnaioni C, Toti A, Camici G, Cirri P. Low molecular weight protein tyrosine phosphatase: Multifaceted functions of an evolutionarily conserved enzyme. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2016; 1864:1339-55. [PMID: 27421795 DOI: 10.1016/j.bbapap.2016.07.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Revised: 07/05/2016] [Accepted: 07/11/2016] [Indexed: 12/31/2022]
Abstract
Originally identified as a low molecular weight acid phosphatase, LMW-PTP is actually a protein tyrosine phosphatase that acts on many phosphotyrosine-containing cellular proteins that are primarily involved in signal transduction. Differences in sequence, structure, and substrate recognition as well as in subcellular localization in different organisms enable LMW-PTP to exert many different functions. In fact, during evolution, the LMW-PTP structure adapted to perform different catalytic actions depending on the organism type. In bacteria, this enzyme is involved in the biosynthesis of group 1 and 4 capsules, but it is also a virulence factor in pathogenic strains. In yeast, LMW-PTPs dephosphorylate immunophilin Fpr3, a peptidyl-prolyl-cis-trans isomerase member of the protein chaperone family. In humans, LMW-PTP is encoded by the ACP1 gene, which is composed of three different alleles, each encoding two active enzymes produced by alternative RNA splicing. In animals, LMW-PTP dephosphorylates a number of growth factor receptors and modulates their signalling processes. The involvement of LMW-PTP in cancer progression and in insulin receptor regulation as well as its actions as a virulence factor in a number of pathogenic bacterial strains may promote the search for potent, selective and bioavailable LMW-PTP inhibitors.
Collapse
Affiliation(s)
- Anna Caselli
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Firenze, Viale Morgagni 50, 50134 Florence, Italy.
| | - Paolo Paoli
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Firenze, Viale Morgagni 50, 50134 Florence, Italy.
| | - Alice Santi
- Vascular Proteomics, Cancer Research UK Beatson Institute, Switchback Road, Glasgow G61 1BD, UK.
| | - Camilla Mugnaioni
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Firenze, Viale Morgagni 50, 50134 Florence, Italy.
| | - Alessandra Toti
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Firenze, Viale Morgagni 50, 50134 Florence, Italy.
| | - Guido Camici
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Firenze, Viale Morgagni 50, 50134 Florence, Italy.
| | - Paolo Cirri
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Firenze, Viale Morgagni 50, 50134 Florence, Italy.
| |
Collapse
|
12
|
Karimi Galougahi K, Ashley EA, Ali ZA. Redox regulation of vascular remodeling. Cell Mol Life Sci 2016; 73:349-63. [PMID: 26483132 PMCID: PMC11108558 DOI: 10.1007/s00018-015-2068-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 10/05/2015] [Accepted: 10/08/2015] [Indexed: 01/09/2023]
Abstract
Vascular remodeling is a dynamic process of structural and functional changes in response to biochemical and biomechanical signals in a complex in vivo milieu. While inherently adaptive, dysregulation leads to maladaptive remodeling. Reactive oxygen species participate in homeostatic cell signaling in tightly regulated- and compartmentalized cellular circuits. It is well established that perturbations in oxidation-reduction (redox) homeostasis can lead to a state of oxidative-, and more recently, reductive stress. We provide an overview of the redox signaling in the vasculature and review the role of oxidative- and reductive stress in maladaptive vascular remodeling. Particular emphasis has been placed on essential processes that determine phenotype modulation, migration and fate of the main cell types in the vessel wall. Recent advances in systems biology and the translational opportunities they may provide to specifically target the redox pathways driving pathological vascular remodeling are discussed.
Collapse
Affiliation(s)
- Keyvan Karimi Galougahi
- Division of Cardiology, Center for Interventional Vascular Therapy, New York Presbyterian Hospital and Columbia University, New York, NY, USA.
- Sydney Medical School Foundation, University of Sydney, Sydney, Australia.
| | - Euan A Ashley
- Division of Cardiology, Stanford University, Stanford, CA, USA
| | - Ziad A Ali
- Division of Cardiology, Center for Interventional Vascular Therapy, New York Presbyterian Hospital and Columbia University, New York, NY, USA
- Cardiovascular Research Foundation, New York, NY, USA
| |
Collapse
|
13
|
Buricchi F, Giannoni E, Grimaldi G, Parri M, Raugei G, Ramponi G, Chiarugi P. Redox Regulation of Ephrin/Integrin Cross-Talk. Cell Adh Migr 2014. [DOI: 10.4161/cam.3911] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
|
14
|
He RJ, Yu ZH, Zhang RY, Zhang ZY. Protein tyrosine phosphatases as potential therapeutic targets. Acta Pharmacol Sin 2014; 35:1227-46. [PMID: 25220640 DOI: 10.1038/aps.2014.80] [Citation(s) in RCA: 246] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 07/31/2014] [Indexed: 12/17/2022] Open
Abstract
Protein tyrosine phosphorylation is a key regulatory process in virtually all aspects of cellular functions. Dysregulation of protein tyrosine phosphorylation is a major cause of human diseases, such as cancers, diabetes, autoimmune disorders, and neurological diseases. Indeed, protein tyrosine phosphorylation-mediated signaling events offer ample therapeutic targets, and drug discovery efforts to date have brought over two dozen kinase inhibitors to the clinic. Accordingly, protein tyrosine phosphatases (PTPs) are considered next-generation drug targets. For instance, PTP1B is a well-known targets of type 2 diabetes and obesity, and recent studies indicate that it is also a promising target for breast cancer. SHP2 is a bona-fide oncoprotein, mutations of which cause juvenile myelomonocytic leukemia, acute myeloid leukemia, and solid tumors. In addition, LYP is strongly associated with type 1 diabetes and many other autoimmune diseases. This review summarizes recent findings on several highly recognized PTP family drug targets, including PTP1B, Src homology phosphotyrosyl phosphatase 2(SHP2), lymphoid-specific tyrosine phosphatase (LYP), CD45, Fas associated phosphatase-1 (FAP-1), striatal enriched tyrosine phosphatases (STEP), mitogen-activated protein kinase/dual-specificity phosphatase 1 (MKP-1), phosphatases of regenerating liver-1 (PRL), low molecular weight PTPs (LMWPTP), and CDC25. Given that there are over 100 family members, we hope this review will serve as a road map for innovative drug discovery targeting PTPs.
Collapse
|
15
|
The role of low-molecular-weight protein tyrosine phosphatase (LMW-PTP ACP1) in oncogenesis. Tumour Biol 2013; 34:1979-89. [DOI: 10.1007/s13277-013-0784-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 03/27/2013] [Indexed: 01/20/2023] Open
|
16
|
Reactive oxygen species are induced by Kaposi's sarcoma-associated herpesvirus early during primary infection of endothelial cells to promote virus entry. J Virol 2012; 87:1733-49. [PMID: 23175375 DOI: 10.1128/jvi.02958-12] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The entry of Kaposi's sarcoma-associated herpesvirus (KSHV) into human dermal microvascular endothelial cells (HMVEC-d), natural in vivo target cells, via macropinocytosis is initiated through a multistep process involving the binding of KSHV envelope glycoproteins with cell surface α3β1, αVβ3, and αVβ5 integrin molecules and tyrosine kinase ephrin-A2 receptor, followed by the activation of preexisting integrin-associated signaling molecules such as focal adhesion kinase (FAK), Src, c-Cbl, phosphoinositide 3-kinase (PI-3K), and Rho-GTPases. Many viruses, including KSHV, utilize cellular reactive oxygen species (ROS) for viral genomic replication and survival within host cells; however, the role of ROS in early events of viral entry and the induction of signaling has not been elucidated. Here we show that KSHV induced ROS production very early during the infection of HMVEC-d cells and that ROS production was sustained over the observation period (24 h postinfection). ROS induction was dependent on the binding of KSHV to the target cells, since pretreatment of the virus with heparin abolished ROS induction. Pretreatment of HMVEC-d cells with the antioxidant N-acetylcysteine (NAC) significantly inhibited KSHV entry, and consequently gene expression, without affecting virus binding. In contrast, H(2)O(2) treatment increased the levels of KSHV entry and infection. In addition, NAC inhibited KSHV infection-induced translocation of αVβ3 integrin into lipid rafts, actin-dependent membrane perturbations, such as blebs, observed during macropinocytosis, and activation of the signal molecules ephrin-A2 receptor, FAK, Src, and Rac1. In contrast, H(2)O(2) treatment increased the activation of ephrin-A2, FAK, Src, and Rac1. These studies demonstrate that KSHV infection induces ROS very early during infection to amplify the signaling pathways necessary for its efficient entry into HMVEC-d cells via macropinocytosis.
Collapse
|
17
|
Teruel M, Martin JE, Gómez-García M, Cardeña C, Rodrigo L, Nieto A, Alcain G, Cueto I, López-Nevot MA, Martin J. Lack of association of ACP1 gene with inflammatory bowel disease: a case-control study. ACTA ACUST UNITED AC 2012; 80:61-4. [PMID: 22428720 DOI: 10.1111/j.1399-0039.2012.01861.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The red cell acid phosphatease (ACP1) gene, which encodes a low molecular weight phosphotyrosine phosphatase (LMW-PTP), has been suggested as a common genetic factor of autoimmunity. In the present study, we aimed to investigate the possible influence of ACP1 polymorphisms in the susceptibility of inflammatory bowel disease (IBD). A total of 1271 IBD Spanish patients [720 Crohn's disease (CD) and 551 ulcerative colitis (UC)] and 1877 healthy subjects were included. Four single-nucleotide polymorphisms (SNPs), rs10167992, rs11553742, rs7576247 and rs3828329, were genotyped using TaqMan SNP genotyping assays. Common ACP1 alleles (i.e. ACP1*A, ACP1*B and ACP1*C) were determined by two of these SNPs. After the analysis, no evidence of association of the ACP1 genetic variants was found with CD or UC. Therefore, our results suggest that the ACP1 gene may not play a relevant role in the development of IBD.
Collapse
Affiliation(s)
- M Teruel
- Instituto de Parasitología y Biomedicina López-Neyra, IPBLN-CSIC, Armilla, Granada, Spain.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Maccari R, Ottanà R. Low molecular weight phosphotyrosine protein phosphatases as emerging targets for the design of novel therapeutic agents. J Med Chem 2011; 55:2-22. [PMID: 21988196 DOI: 10.1021/jm200607g] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Rosanna Maccari
- Dipartimento Farmaco-Chimico, Faculty of Pharmacy, University of Messina, Polo Universitario dell'Annunziata, 98168 Messina, Italy.
| | | |
Collapse
|
19
|
Lai IR, Chu PY, Lin HS, Liou JY, Jan YJ, Lee JC, Shen TL. Phosphorylation of focal adhesion kinase at Tyr397 in gastric carcinomas and its clinical significance. THE AMERICAN JOURNAL OF PATHOLOGY 2010; 177:1629-37. [PMID: 20724588 DOI: 10.2353/ajpath.2010.100172] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Focal adhesion kinase (FAK) has been implicated in tumorigenesis in various cancers; however, it remains unclear how FAK participates in tumor malignancy in vivo. This study seeks to understand the role of FAK activation in gastric cancer progression. Using immunohistochemical staining and Western blotting, we found that pY397 FAK, an autophosphorylation site on FAK activation, was abundant in the cancerous tissues of 21 of 59 patients with gastric carcinomas. We attempted to correlate clinicopathological parameters, including histological types, TNM staging, and cancer recurrence, with the expression of FAK and pY397 FAK in cancerous tissues. Intriguingly, patients with higher levels of pY397 FAK displayed higher incidences of gastric cancer recurrence after surgery and poor 5-year recurrence-free survival. Furthermore, multivariate analyses showed that pY397 FAK was an independent predictor of gastric cancer recurrence. As a result, expression of pY397 FAK is a significant prognostic factor for the recurrence of gastric cancer. Additionally, in vitro studies showed that overexpression of Y397F, a dominant-negative mutant of FAK, in AGS human gastric carcinoma cells impaired cell migration, invasion, and proliferation compared with cells overexpressing wild-type FAK. Thus, activation of FAK through autophosphorylation at Tyr397 leads to the progression of gastric carcinomas by promoting cell migration, invasion, and proliferation. Collectively, our results have provided valuable insights for the development of novel diagnoses and therapeutic targets for gastric cancer treatments.
Collapse
Affiliation(s)
- I-Rue Lai
- Graduate Institute of Anatomy and Cell Biology, National Taiwan University College of Medicine, Taipei, Taiwan
| | | | | | | | | | | | | |
Collapse
|
20
|
Ruela-de-Sousa RR, Queiroz KCS, Peppelenbosch MP, Fuhler GM. Reversible phosphorylation in haematological malignancies: potential role for protein tyrosine phosphatases in treatment? Biochim Biophys Acta Rev Cancer 2010; 1806:287-303. [PMID: 20659529 DOI: 10.1016/j.bbcan.2010.07.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Revised: 07/16/2010] [Accepted: 07/20/2010] [Indexed: 01/12/2023]
Abstract
Most aspects of leukocyte physiology are under the control of reversible tyrosine phosphorylation. It is clear that excessive phosphorylation of signal transduction elements is a pivotal element of many different pathologies including haematological malignancies and accordingly, strategies that target such phosphorylation have clinically been proven highly successful for treatment of multiple types of leukemias and lymphomas. Cellular phosphorylation status is dependent on the resultant activity of kinases and phosphatases. The cell biology of the former is now well understood; for most cellular phosphoproteins we now know the kinases responsible for their phosphorylation and we understand the principles of their aberrant activity in disease. With respect to phosphatases, however, our knowledge is much patchier. Although the sequences of whole genomes allow us to identify phosphatases using in silico methodology, whereas transcription profiling allows us to understand how phosphatase expression is regulated during disease, most functional questions as to substrate specificity, dynamic regulation of phosphatase activity and potential for therapeutic intervention are still to a large degree open. Nevertheless, recent studies have allowed us to make meaningful statements on the role of tyrosine phosphatase activity in the three major signaling pathways that are commonly affected in leukemias, i.e. the Ras-Raf-ERK1/2, the Jak-STAT and the PI3K-PKB-mTOR pathways. Lessons learned from these pathways may well be applicable elsewhere in leukocyte biology as well.
Collapse
Affiliation(s)
- Roberta R Ruela-de-Sousa
- Center for Experimental and Molecular Medicine, Academic Medical Center, Meibergdreef 9 1105 AZ Amsterdam, The Netherlands
| | | | | | | |
Collapse
|
21
|
Abstract
Vascular smooth muscle cell migration is important during vascular development and contributes to lesion formation in the adult vasculature. The mechanisms regulating migration of this cell type are therefore of great interest. Recent work has shown that reactive oxygen species (ROS) derived from NADPH oxidases are important mediators of promigratory signaling pathways. ROS regulate the intracellular signals responsible for lamellipodia formation, actin cytoskeleton remodeling, focal adhesion turnover, and contraction of the cell body. In addition, they contribute to matrix remodeling, a critical step to initiate and support vascular smooth muscle cell motility. Despite these recent advances in our understanding of the redox mechanisms that contribute to migration, additional work is needed to evaluate fully the potential of ROS-sensitive molecular signals as therapeutic targets to prevent inappropriate smooth muscle cell migration.
Collapse
|
22
|
Kong T, Xu D, Yu W, Takakura A, Boucher I, Tran M, Kreidberg JA, Shah J, Zhou J, Denker BM. G alpha 12 inhibits alpha2 beta1 integrin-mediated Madin-Darby canine kidney cell attachment and migration on collagen-I and blocks tubulogenesis. Mol Biol Cell 2009; 20:4596-610. [PMID: 19776354 DOI: 10.1091/mbc.e09-03-0220] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Regulation of epithelial cell attachment and migration are essential for normal development and maintenance of numerous tissues. G proteins and integrins are critical signaling proteins regulating these processes, yet in polarized cells little is known about the interaction of these pathways. Herein, we demonstrate that G alpha 12 inhibits interaction of MDCK cells with collagen-I, the major ligand for alpha2 beta1 integrin. Activating G alpha 12 (QL point mutation or stimulating endogenous G alpha 12 with thrombin) inhibited focal adhesions and lamellipodia formation and led to impaired cell migration. Consistent with G alpha 12-regulated attachment to collagen-I, G alpha 12-silenced MDCK cells revealed a more adherent phenotype. Inhibiting Rho kinase completely restored normal attachment in G alpha 12-activated cells, and there was partial recovery with inhibition of Src and protein phosphatase pathways. G alpha 12 activation led to decreased phosphorylation of focal adhesion kinase and paxillin with displacement of alpha2 integrin from the focal adhesion protein complex. Using the MDCK cell 3D-tubulogenesis assay, activated G alpha 12 inhibited tubulogenesis and led to the formation of cyst-like structures. Furthermore, G alpha 12-silenced MDCK cells were resistant to thrombin-stimulated cyst development. Taken together, these studies provide direct evidence for G alpha 12-integrin regulation of epithelial cell spreading and migration necessary for normal tubulogenesis.
Collapse
Affiliation(s)
- Tianqing Kong
- Renal Division, Brigham and Women's Hospital, Harvard Institutes of Medicine, Boston, MA 02115, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Rovida E, Navari N, Caligiuri A, Dello Sbarba P, Marra F. ERK5 differentially regulates PDGF-induced proliferation and migration of hepatic stellate cells. J Hepatol 2008; 48:107-15. [PMID: 17998143 DOI: 10.1016/j.jhep.2007.08.010] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2007] [Revised: 08/04/2007] [Accepted: 08/06/2007] [Indexed: 01/15/2023]
Abstract
BACKGROUND/AIMS Hepatic stellate cells (HSC) are liver-specific pericytes implicated in liver tissue repair. Activation of signaling pathways in HSC modulates hepatic fibrogenesis, but no information is available on the possible role of ERK5, a member of the mitogen-activated protein kinase family, in this process. In this study, we investigated the role of ERK5 in the biologic responses triggered by platelet-derived growth factor (PDGF) in HSC. METHODS Human HSC were cultured on plastic and studied in their myofibroblast-like phenotype. RESULTS PDGF-BB rapidly induced ERK5 activation and translocation to the nucleus. EGF and PDGF-DD were also found to activate ERK5. Interfering with Src activation blocked PDGF-BB-dependent ERK5 phosphorylation. To establish the biological significance of ERK5 activation, HSC were transfected with non-targeting siRNA or siRNA targeting ERK5. ERK5 silencing inhibited PDGF-BB-induced cell proliferation, and expression and activation of c-Jun. In contrast, depletion of ERK5 was associated with significantly increased cell migration, both in the presence or absence of PDGF-BB. This effect was associated with a redistribution of focal contacts, and with decreased phosphorylation of FAK, paxillin, and PAK. CONCLUSIONS ERK5 modulates PDGF-dependent biologic activities in human HSC, generating positive signals for cell proliferation downregulating the ability of the cells to migrate.
Collapse
Affiliation(s)
- Elisabetta Rovida
- Dipartimento di Patologia e Oncologia Sperimentali, University of Florence, Italy
| | | | | | | | | |
Collapse
|
24
|
Lee JK, Edderkaoui M, Truong P, Ohno I, Jang KT, Berti A, Pandol SJ, Gukovskaya AS. NADPH oxidase promotes pancreatic cancer cell survival via inhibiting JAK2 dephosphorylation by tyrosine phosphatases. Gastroenterology 2007; 133:1637-48. [PMID: 17983808 DOI: 10.1053/j.gastro.2007.08.022] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2006] [Accepted: 07/26/2007] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS Growth factors, such as insulin-like growth factor-1 (IGF-I), protect pancreatic cancer (PaCa) cells from death. We recently showed that reactive oxygen species (ROS) produced by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase Nox4 mediate the antiapoptotic effect of growth factors. Here, we examine the mechanisms of the antiapoptotic role of NADPH oxidase. We hypothesized that ROSs produced by NADPH oxidase inhibit key protein tyrosine phosphatases (PTPs) and thus sustain the activation of kinases mediating antiapoptotic pathways in PaCa cells. METHODS Transfections and pharmacologic inhibition were used to assess the effects of NADPH oxidase on Janus kinase 2 (JAK2) kinase, the low molecular weight-protein tyrosine phosphatase (LMW-PTP), and apoptosis. RESULTS We found that 1 target of ROSs is JAK2, an important antiapoptotic kinase in PaCa cells. Both serum-induced and IGF-I biphasic JAK2 phosphorylation, with a rapid (minutes) and transient first phase, and a slow and sustained (24-72 hours) second phase. Nox4 mediated the sustained phase of JAK2 phosphorylation, which was required for the antiapoptotic effects of IGF-I and serum. Transfection experiments identified the LMW-PTP as a negative regulator of sustained JAK2 phosphorylation. Growth factors inhibited LMW-PTP through its oxidation by NADPH oxidase. LMW-PTP colocalizes with Nox4 both in PaCa cells and in human pancreatic adenocarcinoma. CONCLUSIONS The results suggest a novel signaling pathway, in which NADPH oxidase activation results in inhibition of PTPs, such as LMW-PTP, leading, in turn, to enhanced and sustained phosphorylation of kinases, such as JAK2, and suppression of apoptosis. This pathway mediates the prosurvival effect of ROSs and suggests new targets for pancreatic cancer treatment.
Collapse
Affiliation(s)
- Jong Kyun Lee
- Veterans Affairs Greater Los Angeles Healthcare System and University of California at Los Angeles, Los Angeles, CA, USA
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Mancini F, Rigacci S, Berti A, Balduini C, Torti M. The low-molecular-weight phosphotyrosine phosphatase is a negative regulator of FcγRIIA-mediated cell activation. Blood 2007; 110:1871-8. [PMID: 17537991 DOI: 10.1182/blood-2007-03-081414] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractActivation of human platelets by cross-linking of the low-affinity receptor for immunoglobulin G (FcγRIIA) is initiated by Src kinase–mediated phosphorylation of the immunoreceptor tyrosine–based activation motif (ITAM) within the receptor, but the identity of the enzyme responsible for its dephosphorylation and inactivation is unknown. Here we report that the 18-kDa low-molecular-weight phosphotyrosine phosphatase (LMW-PTP) is expressed in human platelets and undergoes subcellular redistribution upon FcγRIIA cross-linking. In vitro, LMW-PTP was found to efficiently dephosphorylate activated FcγRIIA and LAT, but not Syk or phospholipase Cγ2. In the megakaryocytic cell line DAMI, antibody-induced phosphorylation of FcγRIIA was rapid and transient. The late dephosphorylation of FcγRIIA was dramatically delayed upon reduction of LMW-PTP expression by siRNA. Strikingly, overexpression of LMW-PTP resulted in the inhibition of antibody-induced phosphorylation of FcγRIIA, and caused a more rapid dephosphorylation. In addition, overexpression of LMW-PTP inhibited activation of Syk downstream of FcγRIIA and reduced intracellular Ca2+ mobilization. These results demonstrate that LMW-PTP is responsible for FcγRIIA dephosphorylation, and is implicated in the down-regulation of cell activation mediated by this ITAM-bearing immunoreceptor.
Collapse
|
26
|
Lai YJ, Lin WC, Lin FT. PTPL1/FAP-1 negatively regulates TRIP6 function in lysophosphatidic acid-induced cell migration. J Biol Chem 2007; 282:24381-7. [PMID: 17591779 PMCID: PMC3923842 DOI: 10.1074/jbc.m701499200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The LIM domain-containing TRIP6 (Thyroid Hormone Receptor-interacting Protein 6) is a focal adhesion molecule known to regulate lysophosphatidic acid (LPA)-induced cell migration through interaction with the LPA2 receptor. LPA stimulation targets TRIP6 to the focal adhesion complexes and promotes c-Src-dependent phosphorylation of TRIP6 at Tyr-55, which creates a docking site for the Crk Src homology 2 domain, thereby promoting LPA-induced morphological changes and cell migration. Here we further demonstrate that a switch from c-Src-mediated phosphorylation to PTPL1/Fas-associated phosphatase-1-dependent dephosphorylation serves as an inhibitory feedback control mechanism of TRIP6 function in LPA-induced cell migration. PTPL1 dephosphorylates phosphotyrosine 55 of TRIP6 in vitro and inhibits LPA-induced tyrosine phosphorylation of TRIP6 in cells. This negative regulation requires a direct protein-protein interaction between these two molecules and the phosphatase activity of PTPL1. In contrast to c-Src, PTPL1 prevents TRIP6 turnover at the sites of adhesions. As a result, LPA-induced association of TRIP6 with Crk and the function of TRIP6 to promote LPA-induced morphological changes and cell migration are inhibited by PTPL1. Together, these results reveal a novel mechanism by which PTPL1 phosphatase plays a counteracting role in regulating TRIP6 function in LPA-induced cell migration.
Collapse
Affiliation(s)
- Yun-Ju Lai
- Department of Cell Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294-0005
| | - Weei-Chin Lin
- Department of Cell Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294-0005
- Division of Hematology and Oncology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35294-0005
| | - Fang-Tsyr Lin
- Department of Cell Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294-0005
- To whom correspondence should be addressed: Dept. of Cell Biology, The University of Alabama at Birmingham, MCLM 360A, 1918 University Blvd., Birmingham, AL 35294-0005. Tel.: 205-975-5060; Fax: 205-975-5648;
| |
Collapse
|
27
|
Herrera Abreu MT, Wang Q, Vachon E, Suzuki T, Chow CW, Wang Y, Hong O, Villar J, McCulloch CAG, Downey GP. Tyrosine phosphatase SHP-2 regulates IL-1 signaling in fibroblasts through focal adhesions. J Cell Physiol 2006; 207:132-43. [PMID: 16250012 DOI: 10.1002/jcp.20544] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Interleukin-1beta (IL-1beta) mediates destruction of matrix collagens in diverse inflammatory diseases including arthritis, periodontitis, and pulmonary fibrosis by activating fibroblasts, cells that interact with matrix proteins through integrin-based adhesions. In vitro, IL-1beta signaling is modulated by focal adhesions, supramolecular protein complexes that are enriched with tyrosine kinases and phosphatases. We assessed the importance of tyrosine phosphatases in regulating cell-matrix interactions and IL-1beta signaling. In human gingival fibroblasts plated on fibronectin, IL-1beta enhanced the maturation of focal adhesions as defined by morphology and enrichment with paxillin and alpha-actinin. IL-1beta also induced activation of ERK and recruitment of phospho-ERK to focal complexes/adhesions. Treatment with the potent tyrosine phosphatase inhibitor pervanadate, in the absence of IL-1beta, recapitulated many of these responses indicating the importance of tyrosine phosphatases. Immunoblotting of collagen bead-associated complexes revealed that the tyrosine phosphatase, SHP-2, was also enriched in focal complexes/adhesions. Depletion of SHP-2 by siRNA or by homologous recombination markedly altered IL-1beta-induced ERK activation and maturation of focal adhesions. IL-1beta-induced tyrosine phosphorylation of SHP-2 on residue Y542 promoted focal adhesion maturation. Association of Gab1 with SHP-2 in focal adhesions correlated temporally with activation of ERK and was abrogated in cells expressing mutant (Y542F) SHP-2. We conclude that IL-1beta mediated maturation of focal adhesions is dependent on tyrosine phosphorylation of SHP-2 at Y542, leading to recruitment of Gab1, a process that may influence the downstream activation of ERK.
Collapse
Affiliation(s)
- Maria Teresa Herrera Abreu
- Department of Medicine, University of Toronto, Toronto General Hospital Research Institute of the University Health Network, Ontario, Canada
| | | | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Zhang Z, Lin SY, Neel BG, Haimovich B. Phosphorylated α-Actinin and Protein-tyrosine Phosphatase 1B Coregulate the Disassembly of the Focal Adhesion Kinase·Src Complex and Promote Cell Migration. J Biol Chem 2006; 281:1746-54. [PMID: 16291744 DOI: 10.1074/jbc.m509590200] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The focal adhesion kinase (FAK) is a key regulator of cell migration. Phosphorylation at Tyr-397 activates FAK and creates a binding site for Src family kinases. FAK phosphorylates the cytoskeletal protein alpha-actinin at Tyr-12. Here we report that protein-tyrosine phosphatase 1B (PTP 1B) is an alpha-actinin phosphatase. PTP 1B-dependent dephosphorylation of alpha-actinin was seen in COS-7 cells and PTP 1B-null fibroblasts reconstituted with PTP 1B. Furthermore, we show that coexpression of wild-type alpha-actinin and PTP 1B causes dephosphorylation at Tyr-397 in FAK. No dephosphorylation was observed in cells coexpressing the alpha-actinin phosphorylation mutant Y12F and PTP 1B. Furthermore, the phosphorylation at four other sites in FAK was not altered by PTP 1B. In addition, we found that phosphorylated alpha-actinin bound to Src and reduced the binding of FAK to Src. The dephosphorylation at Tyr-397 in FAK triggered by wild-type alpha-actinin and PTP 1B caused a significant increase in cell migration. We propose that phosphorylated alpha-actinin disrupts the FAK x Src complex exposing Tyr-397 in FAK to PTP 1B. These findings uncover a novel feedback loop involving phosphorylated alpha-actinin and PTP 1B that regulates FAK x Src interaction and cell migration.
Collapse
Affiliation(s)
- Zhiyong Zhang
- Department of Surgery, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, New Brunswick 08903, USA
| | | | | | | |
Collapse
|
29
|
Taddei ML, Chiarugi P, Cuevas C, Ramponi G, Raugei G. Oxidation and inactivation of low molecular weight protein tyrosine phosphatase by the anticancer drug Aplidin. Int J Cancer 2005; 118:2082-8. [PMID: 16287083 DOI: 10.1002/ijc.21602] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The marine plitidepsin Aplidin derived from the Mediterranean tunicate Aplidium albicans is a strong apoptotic inducer with promising antitumor activity. However, little is known about the mechanism of action of the molecule. In this article, we report that Aplidin is cytotoxic for NIH3T3 cells and that its action is exerted through the production of reactive oxygen species (ROS). Rotenone, but not other selective inhibitors of ROS production, blocks the induction of ROS, suggesting the involvement of the mitochondrial respiratory chain in Aplidin action. The intracellular rise of redox potential caused by Aplidin inactivates several molecular targets. Among these targets, we focused our attention on protein tyrosine phosphatases (PTPs). In agreement with the well-characterized effect of ROS-mediated PTP oxidation, due to the presence of a cysteine residue in their catalytic site, we found that Aplidin induces a strong decrease in PTP activity. In particular, since the expression of low molecular weight-PTP (LMW-PTP) is strongly associated with tumor onset and progression, we investigated the effect of Aplidin on this enzyme. Our data show that LMW-PTP is oxidized and inactivated during Aplidin treatment, thus causing a hyper-phosphorylation of its substrate beta-catenin. These findings demonstrate that, at least in part, the antitumoral activity of Aplidin could be due to the direct inhibition of LMW-PTP and its related oncogenic potential.
Collapse
Affiliation(s)
- Maria Letizia Taddei
- Department of Biochemical Sciences, University of Florence, viale Morgagni 50, 50134 Florence, Italy
| | | | | | | | | |
Collapse
|
30
|
Chiarugi P, Giannoni E. Anchorage-dependent cell growth: tyrosine kinases and phosphatases meet redox regulation. Antioxid Redox Signal 2005; 7:578-92. [PMID: 15890002 DOI: 10.1089/ars.2005.7.578] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Recent data have provided new insight concerning the regulation of nontransformed cell proliferation in response to both soluble growth factors and adhesive cues. Nontransformed cells are anchorage-dependent for the execution of the complete mitotic program and cannot avoid the concomitant signals starting from mitogenic molecules, as growth factors, and adhesive agents belonging to the extracellular matrix. Protein tyrosine kinases (PTKs) and phosphotyrosine phosphatases (PTPs) together with soluble small molecules have been included among intracellular signal transducers of growth factor and extracellular matrix receptors. Reactive oxygen species retain a key role during both growth factor and integrin receptor signaling, and these second messengers are recognized to be a synergistic point of confluence for anchorage-dependent growth signaling. Redox-regulated proteins include PTPs and PTKs, although with opposite regulation of enzymatic activity. Transient oxidation of PTPs leads to their inactivation, through the formation of an intramolecular S-S bridge. Conversely, oxidation of PTKs leads to their activation, either by direct SH modification or, indirectly, by concomitant inhibition of PTPs that leads to sustained activation of PTKs. This review will focus on the redox regulation of PTPs and PTKs during anchorage-dependent cell growth and its implications for tumor biology.
Collapse
Affiliation(s)
- Paola Chiarugi
- Department of Biochemical Sciences, University of Florence, Florence, Italy.
| | | |
Collapse
|
31
|
Kang SM, Shin MJ, Kim JH, Oh JW. Proteomic profiling of cellular proteins interacting with the hepatitis C virus core protein. Proteomics 2005; 5:2227-37. [PMID: 15846844 DOI: 10.1002/pmic.200401093] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Hepatitis C virus (HCV) is a causative agent of chronic hepatitis and hepatocellular carcinoma. The core protein of HCV packages the viral RNA genome to form a nucleocapsid. In addition to its function as a structural protein, core protein is involved in regulation of cellular transcription, virus-induced transformation, and pathogenesis. To gain insights into cellular functions of the core protein by identification of cellular proteins interacting with the core protein, we employed a proteomic approach. Hepatocytes soluble cytoplasmic proteins were applied to the core proteins immobilized on Ni-nitrilotriacetic resin and total bound cellular proteins were resolved by 2-DE. Analyses of interacting proteins by matrix-assisted laser desorption/ionization-time of flight mass spectrometry allowed identification of 14 cellular proteins binding to the core protein. These proteins include DEAD-box polypeptide 5, similar in function to a known protein identified previously by yeast two-hybrid screening and 13 newly identified cellular proteins. Interestingly, nine protein spots were identified as intermediate microfilament proteins, including cytokeratins (five spots for cytokeratin 8, two for cytokeratin 19, and one for cytokeratin 18) and vimentin. Cytokeratin 8 and vimentin, which were previously shown to be involved in the infection processes of other viruses, were further analyzed to confirm their in vivo interactions with the core protein by immunoblotting and immunofluorescence microscopy. We discuss the functional implications of the interactions of the core protein with newly identified cellular proteins in HCV infection and pathogenesis.
Collapse
Affiliation(s)
- Su-Min Kang
- Department of Biotechnology, Yonsei University, Seoul, Korea
| | | | | | | |
Collapse
|
32
|
Navab R, Gonzalez-Santos JM, Johnston MR, Liu J, Brodt P, Tsao MS, Hu J. Expression of Chicken Ovalbumin Upstream Promoter-Transcription Factor II Enhances Invasiveness of Human Lung Carcinoma Cells. Cancer Res 2004; 64:5097-105. [PMID: 15289311 DOI: 10.1158/0008-5472.can-03-1185] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII) plays an essential role in angiogenesis and development. It is differentially expressed in tumor cell lines, but its role in carcinogenesis is largely unknown. We demonstrate here that noninvasive human lung cancer cells become invasive when COUP-TFII was expressed. The expression of extracellular matrix degrading proteinases, such as matrix metalloproteinase 2 and urokinase-type plasminogen activator, was up-regulated in these cells. This finding was confirmed by transduction of different human lung cancer cell lines with COUP-TFII protein and also by using antisense expression. We observed disorganization of actin filaments and focal adhesion kinase phosphorylation in COUP-TFII-transfected human lung cancer cells in addition to the increase in extracellular metalloproteinase activity. These results suggest that COUP-TFII may be considered as a new target for anticancer therapies.
Collapse
Affiliation(s)
- Roya Navab
- Lung Biology Research Programme and Canadian Institutes of Health Research Group in Lung Development, The Hospital for Sick Children, 555 University Avenue, Montreal, Quebec, Canada M5G 1X8
| | | | | | | | | | | | | |
Collapse
|
33
|
Abstract
In neutrophils and other phagocytic cells, the small GTPase Rac is an essential regulator of a multi-component NADPH oxidase that produces high levels of superoxide, which kills invading pathogens. In many other cell types, Rac and newly discovered relatives of the neutrophil burst oxidase and its subunits have been found associated with production of reactive oxygen species, implicating superoxide production in a wide range of cellular processes not related to host defense. Although the precise role played by Rac in the regulation of these novel oxidases is not known, Rac does control the cellular redox state. Through these pro-oxidant mechanisms, Rac and the novel oxidases modify gene expression, cell proliferation, adhesion and many cell-specific functions.
Collapse
Affiliation(s)
- Erica Werner
- Department of Cell Biology R455, Emory University, Whitehead Biomedical Research Building, 615 Michael Street, Atlanta GA 30322, USA.
| |
Collapse
|
34
|
Siu MKY, Cheng CY. Extracellular matrix: recent advances on its role in junction dynamics in the seminiferous epithelium during spermatogenesis. Biol Reprod 2004; 71:375-91. [PMID: 15115723 DOI: 10.1095/biolreprod.104.028225] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Spermatogenesis takes place in the seminiferous epithelium of the mammalian testis in which one type A1 spermatogonium (diploid, 2n) gives rise to 256 spermatids (haploid, 1n). To accomplish this, developing germ cells, such as preleptotene and leptotene spermatocytes, residing in the basal compartment of the seminiferous epithelium must traverse the blood-testis barrier (BTB) entering into the adluminal compartment for further development into round, elongating, and elongate spermatids. Recent studies have shown that the basement membrane in the testis (a modified form of extracellular matrix, ECM) is important to the event of germ cell movement across the BTB because proteins in the ECM were shown to regulate BTB dynamics via the interactions between collagens, proteases, and protease inhibitors, possibly under the regulation of cytokines. While these findings are intriguing, they are not entirely unexpected. For one, the basement membrane in the testis is intimately associated with the BTB, which represents the basolateral region of Sertoli cells. Also, Sertoli cell tight junctions (TJs) that constitute the BTB are present side-by-side with cell-cell actin-based adherens junctions (AJ, such as basal ectoplasmic specialization [ES]) and intermediate filament-based desmosome-like junctions. As such, the relative morphological layout between TJs, AJs, and desmosome-like junctions in the seminiferous epithelium is in sharp contrast to other epithelia where TJs are located at the apical portion of an epithelium or endothelium, furthest away from ECM, to be followed by AJs and desmosomes, which in turn constitute the junctional complex. For another, anchoring junctions between a cell epithelium and ECM found in multiple tissues, also known as focal contacts (or focal adhesion complex, FAC, an actin-based cell-matrix anchoring junction type), are the most efficient junction type that permits rapid junction restructuring to accommodate cell movement. It is therefore physiologically plausible, and perhaps essential, that the testis is using some components of the focal contacts to regulate rapid restructuring of AJs between Sertoli and germ cells when germ cells traverse the seminiferous epithelium. Indeed, recent findings have shown that the apical ES, a testis-specific AJ type in the seminiferous epithelium, is equipped with proteins of FAC to regulate its restructuring. In this review, we provide a timely update on this exciting yet rapidly developing field regarding how the homeostasis of basement membrane in the tunica propria regulates BTB dynamics and spermatogenesis in the testis, as well as a critical review on the molecular architecture and the regulation of ES in the seminiferous epithelium.
Collapse
Affiliation(s)
- Michelle K Y Siu
- Population Council, Center for Biomedical Research, 1230 York Avenue, New York, NY 10021, USA
| | | |
Collapse
|
35
|
Rigacci S, Talini D, Berti A. LMW-PTP associates and dephosphorylates STAT5 interacting with its C-terminal domain. Biochem Biophys Res Commun 2004; 312:360-6. [PMID: 14637146 DOI: 10.1016/j.bbrc.2003.10.126] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Hematopoietic cells, particularly megakaryoblastic ones, display a high level of low M(r) phosphotyrosine protein phosphatase (LMW-PTP) expression; nevertheless, the role of this PTP in such cellular lineages has been scarcely investigated. Here, we demonstrate that LMW-PTP is able to associate and dephosphorylate signal transducer and activator of transcription-5 (STAT5) in DAMI megakaryocytic cells. Numerous researchers repeatedly hypothesized the association of a regulatory phosphotyrosine protein phosphatase with STAT5 C-terminus, but such phosphotyrosine protein phosphatase remained unknown. We show evidence indicating that the association of STAT5 and LMW-PTP does not exclusively involve the phosphatase active site and phosphotyrosine residue of STAT5, and we individuate an essential region of interaction at STAT5 C-terminus, coinciding with the previously hypothesized PTP-associating domain.
Collapse
Affiliation(s)
- Stefania Rigacci
- Department of Biochemical Sciences, University of Florence, Viale Morgagni 50, Florence 50134, Italy
| | | | | |
Collapse
|
36
|
Giannoni E, Chiarugi P, Cozzi G, Magnelli L, Taddei ML, Fiaschi T, Buricchi F, Raugei G, Ramponi G. Lymphocyte function-associated antigen-1-mediated T cell adhesion is impaired by low molecular weight phosphotyrosine phosphatase-dependent inhibition of FAK activity. J Biol Chem 2003; 278:36763-76. [PMID: 12815062 DOI: 10.1074/jbc.m302686200] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Protein tyrosine phosphorylation is one of the earliest signaling events detected in response to lymphocyte function-associated antigen-1 (LFA-1) engagement during lymphocyte adhesion. In particular, the focal adhesion kinase p125FAK, involved in the modulation and rearrangement of the actin cytoskeleton, seems to be a crucial mediator of LFA-1 signaling. Herein, we investigate the role of a FAK tyrosine phosphatase, namely low molecular weight phosphotyrosine phosphatase (LMW-PTP), in the modulation of LFA-1-mediated T cell adhesion. Overexpression of LMW-PTP in Jurkat cells revealed an impairment of LFA-1-dependent cell-cell adhesion upon T cell receptor (TCR) stimulation. Moreover, in these conditions LMW-PTP causes FAK dephosphorylation, thus preventing the activation of FAK downstream pathways. Our results also demonstrated that, upon antigen stimulation, LMW-PTP-dependent FAK inhibition is associated to a strong reduction of LFA-1 and TCR co-clustering toward a single region of T cell surface, thus causing an impairment of receptor activity by preventing changes in their avidity state. Because co-localization of both LFA-1 and TCR is an essential event during encounters of T cells with antigen-presenting cells and immunological synapse (IS) formation, we suggest an intriguing role of LMW-PTP in IS establishment and stabilization through the negative control of FAK activity and, in turn, of cell surface receptor redistribution.
Collapse
Affiliation(s)
- Elisa Giannoni
- Dipartimento di Scienze Biochimiche, Università di Firenze, V.le Morgagni 50, 50134 Firenze, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Chiarugi P, Pani G, Giannoni E, Taddei L, Colavitti R, Raugei G, Symons M, Borrello S, Galeotti T, Ramponi G. Reactive oxygen species as essential mediators of cell adhesion: the oxidative inhibition of a FAK tyrosine phosphatase is required for cell adhesion. J Cell Biol 2003; 161:933-44. [PMID: 12796479 PMCID: PMC2172955 DOI: 10.1083/jcb.200211118] [Citation(s) in RCA: 345] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Signal transduction by reactive oxygen species (ROS; "redox signaling") has recently come into focus in cellular biology studies. The signaling properties of ROS are largely due to the reversible oxidation of redox-sensitive target proteins, and especially of protein tyrosine phosphatases, whose activity is dependent on the redox state of a low pKa active site cysteine. A variety of mitogenic signals, including those released by receptor tyrosine kinase (RTKs) ligands and oncogenic H-Ras, involve as a critical downstream event the intracellular generation of ROS. Signaling by integrins is also essential for the growth of most cell types and is constantly integrated with growth factor signaling. We provide here evidence that intracellular ROS are generated after integrin engagement and that these oxidant intermediates are necessary for integrin signaling during fibroblast adhesion and spreading. Moreover, we propose a synergistic action of integrins and RTKs for redox signaling. Integrin-induced ROS are required to oxidize/inhibit the low molecular weight phosphotyrosine phosphatase, thereby preventing the enzyme from dephosphorylating and inactivating FAK. Accordingly, FAK phosphorylation and other downstream events, including MAPK phosphorylation, Src phosphorylation, focal adhesion formation, and cell spreading, are all significantly attenuated by inhibition of redox signaling. Hence, we have outlined a redox circuitry whereby, upon cell adhesion, oxidative inhibition of a protein tyrosine phosphatase promotes the phosphorylation/activation and the downstream signaling of FAK and, as a final event, cell adhesion and spreading onto fibronectin.
Collapse
Affiliation(s)
- Paola Chiarugi
- Department of Biochemical Sciences, University of Florence, Italy
| | | | | | | | | | | | | | | | | | | |
Collapse
|