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Ozgencil F, Gunindi HB, Eren G. Dual-targeted NAMPT inhibitors as a progressive strategy for cancer therapy. Bioorg Chem 2024; 149:107509. [PMID: 38824699 DOI: 10.1016/j.bioorg.2024.107509] [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: 03/09/2024] [Revised: 04/29/2024] [Accepted: 05/28/2024] [Indexed: 06/04/2024]
Abstract
In mammals, nicotinamide phosphoribosyltransferase (NAMPT) is a crucial enzyme in the nicotinamide adenine dinucleotide (NAD+) synthesis pathway catalyzing the condensation of nicotinamide (NAM) with 5-phosphoribosyl-1-pyrophosphate (PRPP) to produce nicotinamide mononucleotide (NMN). Given the pivotal role of NAD+ in a range of cellular functions, including DNA synthesis, redox reactions, cytokine generation, metabolism, and aging, NAMPT has become a promising target for many diseases, notably cancer. Therefore, various NAMPT inhibitors have been reported and classified as first and second-generation based on their chemical structures and design strategies, dual-targeted being one. However, most NAMPT inhibitors suffer from several limitations, such as dose-dependent toxicity and poor pharmacokinetic properties. Consequently, there is no clinically approved NAMPT inhibitor. Hence, research on discovering more effective and less toxic dual-targeted NAMPT inhibitors with desirable pharmacokinetic properties has drawn attention recently. This review summarizes the previously reported dual-targeted NAMPT inhibitors, focusing on their design strategies and advantages over the single-targeted therapies.
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Affiliation(s)
- Fikriye Ozgencil
- SIRTeam Group, Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Gazi University, 06330 Ankara, Türkiye
| | - Habibe Beyza Gunindi
- SIRTeam Group, Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Gazi University, 06330 Ankara, Türkiye
| | - Gokcen Eren
- SIRTeam Group, Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Gazi University, 06330 Ankara, Türkiye.
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Zhang Y, Chen S, Choi T, Qi Y, Wang Q, Li G, Zhao Y. Molecular dynamics simulations reveal the inhibition mechanism of Cdc42 by RhoGDI1. J Comput Aided Mol Des 2023; 37:301-312. [PMID: 37286854 DOI: 10.1007/s10822-023-00508-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 05/22/2023] [Indexed: 06/09/2023]
Abstract
Cell division control protein 42 homolog (Cdc42), which controls a variety of cellular functions including rearrangements of the cell cytoskeleton, cell differentiation and proliferation, is a potential cancer therapeutic target. As an endogenous negative regulator of Cdc42, the Rho GDP dissociation inhibitor 1 (RhoGDI1) can prevent the GDP/GTP exchange of Cdc42 to maintain Cdc42 into an inactive state. To investigate the inhibition mechanism of Cdc42 through RhoGDI1 at the atomic level, we performed molecular dynamics (MD) simulations. Without RhoGDI1, Cdc42 has more flexible conformations, especially in switch regions which are vital for binding GDP/GTP and regulators. In the presence of RhoGDI1, it not only can change the intramolecular interactions of Cdc42 but also can maintain the switch regions into a closed conformation through extensive interactions with Cdc42. These results which are consistent with findings of biochemical and mutational studies provide deep structural insights into the inhibition mechanisms of Cdc42 by RhoGDI1. These findings are beneficial for the development of novel therapies targeting Cdc42-related cancers.
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Affiliation(s)
- Yijing Zhang
- School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Shiyao Chen
- School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Taeyoung Choi
- School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Yuzheng Qi
- School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Qianhui Wang
- School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Guanyi Li
- School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Yaxue Zhao
- School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.
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3
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Gao C, Lai Y, Cheng L, Cheng Y, Miao A, Chen J, Yang R, Xiong F. PIP2 Alteration Caused by Elastic Modulus and Tropism of Electrospun Scaffolds Facilitates Altered BMSCs Proliferation and Differentiation. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2212272. [PMID: 36866457 DOI: 10.1002/adma.202212272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 02/18/2023] [Indexed: 05/05/2023]
Abstract
Aligned submicron fibers have played an essential role in inducing stem cell proliferation and differentiation. In this study, it is aimed to identify the differential causes of stem cell proliferation and differentiation between bone marrow mesenchymal stem cells (BMSCs) on aligned-random fibers with different elastic modulus, and to change the differential levels through a regulatory mechanism mediated by B-cell lymphoma 6 protein(BCL-6) and miRNA-126-5p(miR-126-5p). The results showed that phosphatidylinositol(4,5)bisphosphate alterations are found in the aligned fibers compared with the random fibers, which has a regular and oriented structure, excellent cytocompatibility, regular cytoskeleton, and high differentiation potential. The same trend is actual for the aligned fibers with a lower elastic modulus. The level of proliferative differentiation genes in cells is altered by BCL-6 and miR-126-5p mediated regulatory mechanisms to make the cell distribution nearly consistent with the cell state on low elastic modulus aligned fibers. This work demonstrates the reason for the difference of cells between the two kinds of fibers and on fibers with different elastic modulus. These findings provide more insights for understanding the gene-level regulation of cell growth in tissue engineering.
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Affiliation(s)
- Chen Gao
- State Key Laboratory of Bioelectronics, Jiangsu Key Laboratory for Biomaterials and Devices, School of Biological Science and Medical Engineering, Southeast University, Nanjing, Jiangsu, 210096, China
| | - Yulin Lai
- Key Lab of Oral Diseases Research of Anhui Province, College and Hospital of Stomatology, Anhui Medical University, Hefei, Anhui, 230022, China
- School of Biomedical Engineering, Anhui Medical University, Hefei, 230032, China
| | - Liang Cheng
- Key Lab of Oral Diseases Research of Anhui Province, College and Hospital of Stomatology, Anhui Medical University, Hefei, Anhui, 230022, China
- School of Biomedical Engineering, Anhui Medical University, Hefei, 230032, China
| | - Yifan Cheng
- Key Lab of Oral Diseases Research of Anhui Province, College and Hospital of Stomatology, Anhui Medical University, Hefei, Anhui, 230022, China
- School of Biomedical Engineering, Anhui Medical University, Hefei, 230032, China
| | - Anqi Miao
- Key Lab of Oral Diseases Research of Anhui Province, College and Hospital of Stomatology, Anhui Medical University, Hefei, Anhui, 230022, China
- School of Biomedical Engineering, Anhui Medical University, Hefei, 230032, China
| | - Jialong Chen
- School of Biomedical Engineering, Anhui Medical University, Hefei, 230032, China
| | - Runhuai Yang
- Key Lab of Oral Diseases Research of Anhui Province, College and Hospital of Stomatology, Anhui Medical University, Hefei, Anhui, 230022, China
- School of Biomedical Engineering, Anhui Medical University, Hefei, 230032, China
| | - Fei Xiong
- State Key Laboratory of Bioelectronics, Jiangsu Key Laboratory for Biomaterials and Devices, School of Biological Science and Medical Engineering, Southeast University, Nanjing, Jiangsu, 210096, China
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Chen Z, Yu H, Chen X, Chen W, Song W, Li Z. Mutual regulation between glycosylation and transforming growth factor-β isoforms signaling pathway. Int J Biol Macromol 2023; 236:123818. [PMID: 36858092 DOI: 10.1016/j.ijbiomac.2023.123818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 01/18/2023] [Accepted: 02/19/2023] [Indexed: 03/02/2023]
Abstract
Transforming growth factor-beta (TGF-β) superfamily members orchestrate a wide breadth of biological processes. Through Sma and Mad (Smad)-related dependent or noncanonical pathways, TGF-β members involve in the occurrence and development of many diseases such as cancers, fibrosis, autoimmune diseases, cardiovascular diseases and brain diseases. Glycosylation is one kind of the most common posttranslational modifications on proteins or lipids. Abnormal protein glycosylation can lead to protein malfunction and biological process disorder, thereby causing serious diseases. Previously, researchers commonly make comprehensive systematic overviews on the roles of TGF-β signaling in a specific disease or biological process. In recent years, more and more evidences associate glycosylation modification with TGF-β signaling pathway, and we can no longer disengage and ignore the roles of glycosylation from TGF-β signaling to make investigation. In this review, we provide an overview of current findings involved in glycosylation within TGF-βs and theirs receptors, and the interaction effects between glycosylation and TGF-β subfamily signaling, concluding that there is an intricate mutual regulation between glycosylation and TGF-β signaling, hoping to present the glycosylation regulatory patterns that concealed in TGF-βs signaling pathways.
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Affiliation(s)
- Zhuo Chen
- Laboratory for Functional Glycomics, College of Life Sciences, Northwest University, Xi'an 710069, PR China
| | - Hanjie Yu
- Laboratory for Functional Glycomics, College of Life Sciences, Northwest University, Xi'an 710069, PR China
| | - Xiangqin Chen
- Laboratory for Functional Glycomics, College of Life Sciences, Northwest University, Xi'an 710069, PR China
| | - Wentian Chen
- Laboratory for Functional Glycomics, College of Life Sciences, Northwest University, Xi'an 710069, PR China
| | - Wanghua Song
- Laboratory for Functional Glycomics, College of Life Sciences, Northwest University, Xi'an 710069, PR China
| | - Zheng Li
- Laboratory for Functional Glycomics, College of Life Sciences, Northwest University, Xi'an 710069, PR China.
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5
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Zhu H, Wen Z, Zhang A, Liu D, Wang H, Cheng Y, Yang X, Xiao Y, Li J, Sun D, Wu B, Gao J. RhoGDIα regulates spermatogenesis through Rac1/cofilin/F-actin signaling. Commun Biol 2023; 6:214. [PMID: 36823181 PMCID: PMC9950379 DOI: 10.1038/s42003-023-04579-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 02/10/2023] [Indexed: 02/25/2023] Open
Abstract
Spermatogenesis is an extremely complex process, and any obstruction can cause male infertility. RhoGDIα has been identified as a risk of male sterility. In this study, we generate RhoGDIα knockout mice, and find that the males have severely low fertility. The testes from RhoGDIα-/- mice are smaller than that in WT mice. The numbers of spermatogonia and spermatocytes are decreased in RhoGDIα-/- testis. Spermatogenesis is compromised, and spermatocyte meiosis is arrested at zygotene stage in RhoGDIα-/- mice. Acrosome dysplasia is also observed in sperms of the mutant mice. At the molecular level, RhoGDIα deficiency activate the LIMK/cofilin signaling pathway, inhibiting F-actin depolymerization, impairing testis and inducing low fertility in mouse. In addition, the treatment of RhoGDIα-/- mice with Rac1 inhibitor NSC23766 alleviate testis injury and improve sperm quality by inhibiting the LIMK/cofilin/F-actin pathway during spermatogenesis. Together, these findings reveal a previously unrecognized RhoGDIα/Rac1/F-actin-dependent mechanism involved in spermatogenesis and male fertility.
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Affiliation(s)
- Haixia Zhu
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan, 250100, China
| | - Zongzhuang Wen
- Medical Science and Technology Innovation Center, Shandong First Medical University, Jinan, 250117, China
| | - Aizhen Zhang
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan, 250100, China
| | - Dongyue Liu
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan, 250100, China
| | - Hongxiang Wang
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan, 250100, China
| | - Yin Cheng
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan, 250100, China
| | - Xing Yang
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan, 250100, China
| | - Yu Xiao
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan, 250100, China
| | - Jianyuan Li
- Key Laboratory of Male Reproductive Health, National Health and Family Planning Commission, Beijing, 100081, China
| | - Daqing Sun
- Department of Pediatric Surgery, Tianjin Medical University General Hospital, Tianjin, 300052, China.
| | - Bin Wu
- Department of Reproductive Medicine, Central Hospital Affiliated to Shandong First Medical University, Jinan, 250013, China.
- Cheeloo College of Medicine, Shandong University, Jinan, 250012, China.
| | - Jiangang Gao
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan, 250100, China.
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Gong C, Hu B, Chen H, Zhu J, Nie J, Hua L, Chen L, Fang Y, Hang C, Lu Y. β2-adrenergic receptor drives the metastasis and invasion of pancreatic ductal adenocarcinoma through activating Cdc42 signaling pathway. J Mol Histol 2022; 53:645-655. [PMID: 35717490 DOI: 10.1007/s10735-022-10076-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 05/23/2022] [Indexed: 10/18/2022]
Abstract
Recent investigations indicate that β2-adrenergic receptor (β2-AR) signaling may facilitate the progression of various tumors, whose underlying mechanisms remain largely elusive. In the present study, we showed that β2-AR recruited Cdc42 in response to isoproterenol (ISO, a β-AR selective agonist) exposure in pancreatic ductal adenocarcinoma (PDAC) cells. The association of β2-AR and Cdc42 promoted the activation of Cdc42, as revealed by increased levels of Cdc42-GTP, and co-incubation with β2-AR antagonist abrogated ISO-induced activation of Cdc42. β2-AR-mediated Cdc42 activation further led to the phosphorylation of downstream PAK1, LIMK1 and Merlin. Furthermore, we showed that the activation of β2-AR/Cdc42 signaling facilitated the migration and invasion of PDAC cells. In addition, β2-AR and Cdc42 were overexpressed in PDAC specimens, compared with adjacent non-tumor tissues. High expression of β2-AR and Cdc42 were correlated with lymph node metastasis and TNM stage in PDAC patients. Finally, we showed that overexpression of β2-AR and Cdc42 were indicative of unfavorable prognosis in PDAC patients. Taken together, our findings suggested that β2-AR might facilitate Cdc42 signaling to drive the migration and invasion of PDAC cells, consequently resulting in the metastasis and dismal prognosis of PDAC. These studies highlight targeting β2-AR/Cdc42 signaling as a therapeutic strategy against PDAC.
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Affiliation(s)
- Chen Gong
- Department of Gastroenterology, Taicang Affiliated Hospital of Soochow University, The First People's Hospital of Taicang, Taicang, 215400, Jiangsu Province, China
| | - Baoying Hu
- Department of Immunology, Nantong University School of Medicine, Nantong, 226001, Jiangsu Province, China
| | - Haifeng Chen
- Department of Gastroenterology, Taicang Affiliated Hospital of Soochow University, The First People's Hospital of Taicang, Taicang, 215400, Jiangsu Province, China
| | - Jianxin Zhu
- Department of Gastroenterology, Taicang Affiliated Hospital of Soochow University, The First People's Hospital of Taicang, Taicang, 215400, Jiangsu Province, China
| | - Jinshan Nie
- Department of Gastroenterology, Taicang Affiliated Hospital of Soochow University, The First People's Hospital of Taicang, Taicang, 215400, Jiangsu Province, China
| | - Lu Hua
- Department of Oncology, Taizhou People's Hospital, Taizhou, 225300, Jiangsu Province, China
| | - Long Chen
- Department of Gastroenterology, Taicang Affiliated Hospital of Soochow University, The First People's Hospital of Taicang, Taicang, 215400, Jiangsu Province, China
| | - Yanfei Fang
- Department of Gastroenterology, Taicang Affiliated Hospital of Soochow University, The First People's Hospital of Taicang, Taicang, 215400, Jiangsu Province, China
| | - Cheng Hang
- Department of Gastroenterology, Taicang Affiliated Hospital of Soochow University, The First People's Hospital of Taicang, Taicang, 215400, Jiangsu Province, China.
| | - Ye Lu
- Department of Hematology and Oncology, Taicang Affiliated Hospital of Soochow University, The First People's Hospital of Taicang, Taicang, 215400, Jiangsu Province, China.
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Faria M, Domingues R, Bugalho MJ, Silva AL, Matos P. Analysis of NIS Plasma Membrane Interactors Discloses Key Regulation by a SRC/RAC1/PAK1/PIP5K/EZRIN Pathway with Potential Implications for Radioiodine Re-Sensitization Therapy in Thyroid Cancer. Cancers (Basel) 2021; 13:5460. [PMID: 34771624 PMCID: PMC8582450 DOI: 10.3390/cancers13215460] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 10/14/2021] [Accepted: 10/27/2021] [Indexed: 12/25/2022] Open
Abstract
The functional expression of the sodium-iodide symporter (NIS) at the membrane of differentiated thyroid cancer (DTC) cells is the cornerstone for the use of radioiodine (RAI) therapy in these malignancies. However, NIS gene expression is frequently downregulated in malignant thyroid tissue, and 30% to 50% of metastatic DTCs become refractory to RAI treatment, which dramatically decreases patient survival. Several strategies have been attempted to increase the NIS mRNA levels in refractory DTC cells, so as to re-sensitize refractory tumors to RAI. However, there are many RAI-refractory DTCs in which the NIS mRNA and protein levels are relatively abundant but only reduced levels of iodide uptake are detected, suggesting a posttranslational failure in the delivery of NIS to the plasma membrane (PM), or an impaired residency at the PM. Because little is known about the molecules and pathways regulating NIS delivery to, and residency at, the PM of thyroid cells, we here employed an intact-cell labeling/immunoprecipitation methodology to selectively purify NIS-containing macromolecular complexes from the PM. Using mass spectrometry, we characterized and compared the composition of NIS PM complexes to that of NIS complexes isolated from whole cell (WC) lysates. Applying gene ontology analysis to the obtained MS data, we found that while both the PM-NIS and WC-NIS datasets had in common a considerable number of proteins involved in vesicle transport and protein trafficking, the NIS PM complexes were particularly enriched in proteins associated with the regulation of the actin cytoskeleton. Through a systematic validation of the detected interactions by co-immunoprecipitation and Western blot, followed by the biochemical and functional characterization of the contribution of each interactor to NIS PM residency and iodide uptake, we were able to identify a pathway by which the PM localization and function of NIS depends on its binding to SRC kinase, which leads to the recruitment and activation of the small GTPase RAC1. RAC1 signals through PAK1 and PIP5K to promote ARP2/3-mediated actin polymerization, and the recruitment and binding of the actin anchoring protein EZRIN to NIS, promoting its residency and function at the PM of normal and TC cells. Besides providing novel insights into the regulation of NIS localization and function at the PM of TC cells, our results open new venues for therapeutic intervention in TC, namely the possibility of modulating abnormal SRC signaling in refractory TC from a proliferative/invasive effect to the re-sensitization of these tumors to RAI therapy by inducing NIS retention at the PM.
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Affiliation(s)
- Márcia Faria
- Serviço de Endocrinologia, Diabetes e Metabolismo do CHULN-Hospital Santa Maria, 1649-028 Lisboa, Portugal; (M.F.); (R.D.); (M.J.B.); (A.L.S.)
- BioISI-Biosystems and Integrative Sciences Institute, Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisboa, Portugal
- Departamento de Genética Humana, Instituto Nacional de Saúde Doutor Ricardo Jorge, 1649-016 Lisboa, Portugal
| | - Rita Domingues
- Serviço de Endocrinologia, Diabetes e Metabolismo do CHULN-Hospital Santa Maria, 1649-028 Lisboa, Portugal; (M.F.); (R.D.); (M.J.B.); (A.L.S.)
- ISAMB-Instituto de Saúde Ambiental, Faculdade de Medicina da Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Maria João Bugalho
- Serviço de Endocrinologia, Diabetes e Metabolismo do CHULN-Hospital Santa Maria, 1649-028 Lisboa, Portugal; (M.F.); (R.D.); (M.J.B.); (A.L.S.)
- Serviço de Endocrinologia, Diabetes e Metabolismo, CHULN and Faculdade de Medicina da Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Ana Luísa Silva
- Serviço de Endocrinologia, Diabetes e Metabolismo do CHULN-Hospital Santa Maria, 1649-028 Lisboa, Portugal; (M.F.); (R.D.); (M.J.B.); (A.L.S.)
- ISAMB-Instituto de Saúde Ambiental, Faculdade de Medicina da Universidade de Lisboa, 1649-028 Lisboa, Portugal
- Serviço de Endocrinologia, Diabetes e Metabolismo, CHULN and Faculdade de Medicina da Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Paulo Matos
- BioISI-Biosystems and Integrative Sciences Institute, Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisboa, Portugal
- Departamento de Genética Humana, Instituto Nacional de Saúde Doutor Ricardo Jorge, 1649-016 Lisboa, Portugal
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Filić V, Mijanović L, Putar D, Talajić A, Ćetković H, Weber I. Regulation of the Actin Cytoskeleton via Rho GTPase Signalling in Dictyostelium and Mammalian Cells: A Parallel Slalom. Cells 2021; 10:1592. [PMID: 34202767 PMCID: PMC8305917 DOI: 10.3390/cells10071592] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 06/16/2021] [Accepted: 06/16/2021] [Indexed: 01/15/2023] Open
Abstract
Both Dictyostelium amoebae and mammalian cells are endowed with an elaborate actin cytoskeleton that enables them to perform a multitude of tasks essential for survival. Although these organisms diverged more than a billion years ago, their cells share the capability of chemotactic migration, large-scale endocytosis, binary division effected by actomyosin contraction, and various types of adhesions to other cells and to the extracellular environment. The composition and dynamics of the transient actin-based structures that are engaged in these processes are also astonishingly similar in these evolutionary distant organisms. The question arises whether this remarkable resemblance in the cellular motility hardware is accompanied by a similar correspondence in matching software, the signalling networks that govern the assembly of the actin cytoskeleton. Small GTPases from the Rho family play pivotal roles in the control of the actin cytoskeleton dynamics. Indicatively, Dictyostelium matches mammals in the number of these proteins. We give an overview of the Rho signalling pathways that regulate the actin dynamics in Dictyostelium and compare them with similar signalling networks in mammals. We also provide a phylogeny of Rho GTPases in Amoebozoa, which shows a variability of the Rho inventories across different clades found also in Metazoa.
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Affiliation(s)
- Vedrana Filić
- Division of Molecular Biology, Ruđer Bošković Institute, Bijenička 54, HR-10000 Zagreb, Croatia; (L.M.); (D.P.); (A.T.); (H.Ć.)
| | | | | | | | | | - Igor Weber
- Division of Molecular Biology, Ruđer Bošković Institute, Bijenička 54, HR-10000 Zagreb, Croatia; (L.M.); (D.P.); (A.T.); (H.Ć.)
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9
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Desale SE, Chidambaram H, Chinnathambi S. G-protein coupled receptor, PI3K and Rho signaling pathways regulate the cascades of Tau and amyloid-β in Alzheimer's disease. MOLECULAR BIOMEDICINE 2021; 2:17. [PMID: 35006431 PMCID: PMC8607389 DOI: 10.1186/s43556-021-00036-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 03/18/2021] [Indexed: 12/16/2022] Open
Abstract
Alzheimer's disease is a progressive neurodegenerative disease characterized by the presence of amyloid-β plaques in the extracellular environment and aggregates of Tau protein that forms neurofibrillary tangles (NFTs) in neuronal cells. Along with these pathological proteins, the disease shows neuroinflammation, neuronal death, impairment in the immune function of microglia and synaptic loss, which are mediated by several important signaling pathways. The PI3K/Akt-mediated survival-signaling pathway is activated by many receptors such as G-protein coupled receptors (GPCRs), triggering receptor expressed on myeloid cells 2 (TREM2), and lysophosphatidic acid (LPA) receptor. The signaling pathway not only increases the survival of neurons but also regulates inflammation, phagocytosis, cellular protection, Tau phosphorylation and Aβ secretion as well. In this review, we focused on receptors, which activate PI3K/Akt pathway and its potential to treat Alzheimer's disease. Among several membrane receptors, GPCRs are the major drug targets for therapy, and GPCR signaling pathways are altered during Alzheimer's disease. Several GPCRs are involved in the pathogenic progression, phosphorylation of Tau protein by activation of various cellular kinases and are involved in the amyloidogenic pathway of amyloid-β synthesis. Apart from various GPCR signaling pathways, GPCR regulating/ interacting proteins are involved in the pathogenesis of Alzheimer's disease. These include several small GTPases, Ras homolog enriched in brain, GPCR associated sorting proteins, β-arrestins, etc., that play a critical role in disease progression and has been elaborated in this review.
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Affiliation(s)
- Smita Eknath Desale
- Neurobiology Group, Division of Biochemical Sciences, CSIR-National Chemical Laboratory (CSIR-NCL), Dr. Homi Bhabha Road, Pune, 411008 India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002 India
| | - Hariharakrishnan Chidambaram
- Neurobiology Group, Division of Biochemical Sciences, CSIR-National Chemical Laboratory (CSIR-NCL), Dr. Homi Bhabha Road, Pune, 411008 India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002 India
| | - Subashchandrabose Chinnathambi
- Neurobiology Group, Division of Biochemical Sciences, CSIR-National Chemical Laboratory (CSIR-NCL), Dr. Homi Bhabha Road, Pune, 411008 India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002 India
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10
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Cheng Q, Tang A, Wang Z, Fang N, Zhang Z, Zhang L, Li C, Zeng Y. CALD1 Modulates Gliomas Progression via Facilitating Tumor Angiogenesis. Cancers (Basel) 2021; 13:cancers13112705. [PMID: 34070840 PMCID: PMC8199308 DOI: 10.3390/cancers13112705] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/21/2021] [Accepted: 05/26/2021] [Indexed: 12/13/2022] Open
Abstract
Simple Summary Caldesmon has recently attracted attention in cancer due to its roles in cell migration, invasion and proliferation. l-CALD1 was also considered a potential serum marker for glioma. However, little is known about mechanisms underlying the effect of CALD1 on the microvascular facilitation and architecture in glioma. The purpose of this study was to explore the role of CALD1 for prediction glioma patient prognosis and in glioma angiogenesis. The findings of this study suggested that l-CALD1 could imply abnormal microvessels in anaplastic astrocytoma and GBM. In addition, high CI (calmodulin index) predicted worse prognosis in glioma, and furthermore, CALD1 may serve as a key marker for monitoring the progress of glioma and a novel target for therapy. Abstract Angiogenesis is more prominent in anaplastic gliomas and glioblastoma (GBM) than that in pilocytic and diffuse gliomas. Caldesmon (CALD1) plays roles in cell adhesion, cytoskeletal organization, and vascularization. However, limited information is available on mechanisms underlying the effect of CALD1 on the microvascular facilitation and architecture in glioma. In this study, we explored the role of CALD1 in gliomas by integrating bulk RNA-seq analysis and single cell RNA-seq analysis. A positive correlation between CALD1 expression and the gliomas’ pathological grade was noticed, according to the samples from the TCGA and CGGA database. Moreover, higher CALD1 expression samples showed worse clinical outcomes than lower CALD1 expression samples. Biofunction prediction suggested that CALD1 may affect glioma progression through modulating tumor angiogenesis. The map of the tumor microenvironment also depicted that more stromal cells, such as endothelial cells and pericytes, infiltrated in high CALD1 expression samples. CALD1 was found to be remarkably upregulated in neoplastic cells and was involved in tumorigenic processes of gliomas in single cell sequencing analysis. Histology and immunofluorescence analysis also indicated that CALD1 associates with vessel architecture, resulting in glioma grade progression. In conclusion, the present study implies that CALD1 may serve as putative marker monitoring the progress of glioma.
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Affiliation(s)
- Quan Cheng
- Department of Neurosurgery, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha 410008, China; (Q.C.); (Z.W.); (L.Z.)
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha 410008, China
| | - Anliu Tang
- Department of Gastroenterology, The Third Xiangya Hospital, Central South University, 138 Tongzipo Road, Changsha 410013, China; (A.T.); (N.F.)
| | - Zeyu Wang
- Department of Neurosurgery, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha 410008, China; (Q.C.); (Z.W.); (L.Z.)
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha 410008, China
| | - Ning Fang
- Department of Gastroenterology, The Third Xiangya Hospital, Central South University, 138 Tongzipo Road, Changsha 410013, China; (A.T.); (N.F.)
| | - Zhuojing Zhang
- Department of Scientific Research, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha 410008, China;
| | - Liyang Zhang
- Department of Neurosurgery, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha 410008, China; (Q.C.); (Z.W.); (L.Z.)
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha 410008, China
| | - Chuntao Li
- Department of Neurosurgery, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha 410008, China; (Q.C.); (Z.W.); (L.Z.)
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha 410008, China
- Correspondence: (C.L.); (Y.Z.)
| | - Yu Zeng
- Department of Neurosurgery, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha 410008, China; (Q.C.); (Z.W.); (L.Z.)
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha 410008, China
- Correspondence: (C.L.); (Y.Z.)
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11
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Arumugam A, Subramani R, Lakshmanaswamy R. Involvement of actin cytoskeletal modifications in the inhibition of triple-negative breast cancer growth and metastasis by nimbolide. MOLECULAR THERAPY-ONCOLYTICS 2021; 20:596-606. [PMID: 33768141 PMCID: PMC7972938 DOI: 10.1016/j.omto.2021.02.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Accepted: 02/18/2021] [Indexed: 01/04/2023]
Abstract
Triple-negative breast cancers (TNBCs) are aggressive cancers, which currently do not have effective treatment options. Migration and establishment of metastatic colonies require dynamic cytoskeletal modifications characterized by polymerization and depolymerization of actin. Studies have demonstrated a direct molecular link between the integrin-focal adhesion kinase (FAK) pathway and cytoskeletal modifications. Nimbolide, a major bioactive compound present in neem leaves, shows promising anti-cancer effect on various cancers. In this study, we have demonstrated the growth and metastasis inhibitory potential of nimbolide on TNBC cells. Nimbolide inhibited cell proliferation, migratory, and invasive abilities of TNBC cells and also changed the shape of MDA-MB-231 cells, which is correlated with cytoskeletal changes including actin depolymerization. Furthermore, analysis revealed that integrins αV and β3, ILK, FAK, and PAK levels were downregulated by nimbolide. Even in cells where Rac1/Cdc42 was constitutively activated, nimbolide inhibited the formation of filopodial structures. Immunofluorescence analysis of phosphorylated p21 activated kinase (pPAK) showed reduced expression in nimbolide-treated cells. Nimbolide significantly reduced the metastatic colony formation in lung, liver, and brain of athymic nude mice. In conclusion, our data demonstrate that nimbolide inhibits TNBC by altering the integrin and FAK signaling pathway.
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Affiliation(s)
- Arunkumar Arumugam
- Center of Emphasis in Cancer Research, Department of Biomedical Sciences, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, TX 79905, USA
| | - Ramadevi Subramani
- Center of Emphasis in Cancer Research, Department of Biomedical Sciences, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, TX 79905, USA.,Graduate School of Biomedical Sciences, Texas Tech University Health Sciences Center, El Paso, TX 79905, USA
| | - Rajkumar Lakshmanaswamy
- Center of Emphasis in Cancer Research, Department of Biomedical Sciences, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, TX 79905, USA.,Graduate School of Biomedical Sciences, Texas Tech University Health Sciences Center, El Paso, TX 79905, USA
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12
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Benson CE, Southgate L. The DOCK protein family in vascular development and disease. Angiogenesis 2021; 24:417-433. [PMID: 33548004 PMCID: PMC8292242 DOI: 10.1007/s10456-021-09768-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 01/06/2021] [Accepted: 01/16/2021] [Indexed: 02/07/2023]
Abstract
The vascular network is established and maintained through the processes of vasculogenesis and angiogenesis, which are tightly regulated during embryonic and postnatal life. The formation of a functional vasculature requires critical cellular mechanisms, such as cell migration, proliferation and adhesion, which are dependent on the activity of small Rho GTPases, controlled in part by the dedicator of cytokinesis (DOCK) protein family. Whilst the majority of DOCK proteins are associated with neuronal development, a growing body of evidence has indicated that members of the DOCK family may have key functions in the control of vasculogenic and angiogenic processes. This is supported by the involvement of several angiogenic signalling pathways, including chemokine receptor type 4 (CXCR4), vascular endothelial growth factor (VEGF) and phosphatidylinositol 3-kinase (PI3K), in the regulation of specific DOCK proteins. This review summarises recent progress in understanding the respective roles of DOCK family proteins during vascular development. We focus on existing in vivo and in vitro models and known human disease phenotypes and highlight potential mechanisms of DOCK protein dysfunction in the pathogenesis of vascular disease.
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Affiliation(s)
- Clare E Benson
- Genetics Research Centre, Molecular and Clinical Sciences Research Institute, St. George's University of London, Cranmer Terrace, London, SW17 0RE, UK
| | - Laura Southgate
- Genetics Research Centre, Molecular and Clinical Sciences Research Institute, St. George's University of London, Cranmer Terrace, London, SW17 0RE, UK. .,Department of Medical & Molecular Genetics, Faculty of Life Sciences & Medicine, King's College London, London, SE1 9RT, UK.
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13
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Anti-cancer potential of persimmon (Diospyros kaki) leaves via the PDGFR-Rac-JNK pathway. Sci Rep 2020; 10:18119. [PMID: 33093618 PMCID: PMC7581826 DOI: 10.1038/s41598-020-75140-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 10/09/2020] [Indexed: 12/14/2022] Open
Abstract
Persimmon leaves are known to have some beneficial effects, including ROS elimination, lipid circulation, and neuronal protection. However, their anti-cancer properties and the underlying mechanisms remain unclear. Herein, we show that treatment with the ethanol extract of persimmon, Diospyros kaki, leaves (EEDK) induces cancer cell death and inhibits cell proliferation. Using fluorescence resonance energy transfer (FRET) technology with genetically-encoded biosensors, we first found that EEDK stimulates a PDGFR-Rac signaling cascade in live cells. Moreover, we found that downstream of the PDGFR-Rac pathway, JNKs are activated by EEDK. In contrast, JNK-downstream inhibitors, such as CoCl2, T-5224, and pepstatin A, attenuated EEDK-induced cell death. Thus, we illustrate that the PDGFR-Rac-JNK signaling axis is triggered by EEDK, leading to cancer cell death, suggesting the extract of persimmon leaves may be a promising anti-cancer agent.
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14
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Kim M, Lee Y, Yoo Y, Choi J, Kim H, Kang C, Yu J, Moon S, Kim A, Kim C. Exogenous CLASP2 protein treatment enhances wound healing
in vitro
and
in vivo. Wound Repair Regen 2019; 27:345-359. [DOI: 10.1111/wrr.12713] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 11/16/2018] [Accepted: 11/27/2018] [Indexed: 12/31/2022]
Affiliation(s)
- MiJung Kim
- Division of Life SciencesCollege of Life Sciences and Biotechnology, Korea University 145 Anam‐dong, Sungbuk‐ku, Seoul 136701 South Korea
- Department of BiotechnologyCollege of Life Sciences and Biotechnology, Korea University 145 Anam‐dong, Sungbuk‐ku, Seoul 136701 South Korea
| | - You‐Sun Lee
- Department of BiotechnologyCollege of Life Sciences and Biotechnology, Korea University 145 Anam‐dong, Sungbuk‐ku, Seoul 136701 South Korea
| | - Yun‐Mi Yoo
- Department of BiotechnologyCollege of Life Sciences and Biotechnology, Korea University 145 Anam‐dong, Sungbuk‐ku, Seoul 136701 South Korea
| | - Jong‐Jin Choi
- Department of Stem Cell BiologySchool of Medicine, Konkuk University 120 Neungdong‐ro, Gwangjin‐gu, Seoul 143‐701 South Korea
| | - Ha‐Na Kim
- Department of Stem Cell BiologySchool of Medicine, Konkuk University 120 Neungdong‐ro, Gwangjin‐gu, Seoul 143‐701 South Korea
| | - Changhee Kang
- Department of Stem Cell BiologySchool of Medicine, Konkuk University 120 Neungdong‐ro, Gwangjin‐gu, Seoul 143‐701 South Korea
| | - Ji‐Min Yu
- R&D DivisionCHA Biotech Co. Ltd. 521 CHABIO Complex, 335 Pangyo‐ro, Bundang‐gu Gyeonggi‐Do South Korea
| | - Sung‐Hwan Moon
- Department of MedicineSchool of Medicine, Konkuk University 120 Neungdong‐ro, Gwangjin‐gu, Seoul 143‐701 South Korea
| | - Aeri Kim
- College of Pharmacy, CHA University 521 CHABIO Complex, 335 Pangyo‐ro, Bundang‐gu Gyeonggi‐Do South Korea
| | - Chan‐Wha Kim
- Division of Life SciencesCollege of Life Sciences and Biotechnology, Korea University 145 Anam‐dong, Sungbuk‐ku, Seoul 136701 South Korea
- Department of BiotechnologyCollege of Life Sciences and Biotechnology, Korea University 145 Anam‐dong, Sungbuk‐ku, Seoul 136701 South Korea
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15
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Truong NF, Lesher-Pérez SC, Kurt E, Segura T. Pathways Governing Polyethylenimine Polyplex Transfection in Microporous Annealed Particle Scaffolds. Bioconjug Chem 2019; 30:476-486. [PMID: 30513197 PMCID: PMC7290906 DOI: 10.1021/acs.bioconjchem.8b00696] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Gene delivery using injectable hydrogels can serve as a potential method for regulated tissue regeneration in wound healing. Our microporous annealed particle (MAP) hydrogel has been shown to promote cellular infiltration in both skin and brain wounds, while reducing inflammation. Although the scaffold itself can promote healing, it is likely that other signals will be required to promote healing of hard-to-treat wounds. Gene delivery is one approach to introduce desired bioactive signals. In this study, we investigated how the properties of MAP hydrogels influence non-viral gene delivery of polyethylenimine-condensed plasmid to cells seeded within the MAP gel. From past studies, we found that gene transfer to cells seeded in tissue culture plastic differed from gene transfer to cells seeded inside hydrogel scaffolds. Since MAP scaffolds are generated from hydrogel microparticles that are approximately 100 μm in diameter, they display local characteristics that can be viewed as two-dimensional or three-dimensional to cells. Thus, we sought to study if gene transfer inside MAP scaffolds differed from gene transfer to cells seeded in tissue culture plastic. We sought to understand the roles of the endocytosis pathway, actin and microtubule dynamics, RhoGTPases, and YAP/TAZ on transfection of human fibroblasts.
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Affiliation(s)
- Norman F Truong
- Department of Chemical and Biomolecular Engineering , University of California , Los Angeles , California 90095 , United States
| | - Sasha Cai Lesher-Pérez
- Department of Chemical and Biomolecular Engineering , University of California , Los Angeles , California 90095 , United States
| | - Evan Kurt
- Department of Biomedical Engineering , Duke University , Durham , North Carolina 27708 , United States
| | - Tatiana Segura
- Department of Chemical and Biomolecular Engineering , University of California , Los Angeles , California 90095 , United States
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16
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The Expression Pattern of p120-Catenin is Associated With Acquired Resistance to Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors in Non-Small Cell Lung Cancer. Appl Immunohistochem Mol Morphol 2018; 26:64-70. [PMID: 27299185 DOI: 10.1097/pai.0000000000000381] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Previous research connects p120-catenin (p120ctn) with epidermal growth factor receptor (EGFR) signaling pathways, which presents a potential role for p120ctn in EGFR tyrosine kinase inhibitor (EGFR-TKIs) resistance. However, a direct correlation between the expression pattern of p120ctn in solid tumors and the therapeutic effect of EGFR-TKIs has not yet been demonstrated. METHODS AND RESULTS In this study, the expression pattern of p120ctn was examined in patients with the EGFR gene mutation in lung adenocarcinoma, and p120ctn was found to have different patterns of expression even in the same mutation type. The therapeutic effect of EGFR-TKIs was investigated in these patients, and patients with an abnormal expression of p120ctn were found to be more likely to have drug resistance. A gefitinib-resistant lung cancer cell line was established and alterations in the p120ctn expression pattern were also observed in vitro. CONCLUSIONS Therefore, this study demonstrates that the expression pattern of p120ctn is associated with acquired resistance to EGFR-TKIs in lung cancer, providing information toward addressing the problem of drug resistance in patients with non-small cell lung cancer.
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17
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LaPak KM, Vroom DC, Garg AA, Guan X, Hays JL, Song JW, Burd CE. Melanoma-associated mutants within the serine-rich domain of PAK5 direct kinase activity to mitogenic pathways. Oncotarget 2018; 9:25386-25401. [PMID: 29875996 PMCID: PMC5986637 DOI: 10.18632/oncotarget.25356] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Accepted: 04/26/2018] [Indexed: 02/07/2023] Open
Abstract
The overexpression and hyperactivity of p21-activated serine/threonine kinases (PAKs) is known to facilitate tumorigenesis; however, the contribution of cancer-associated PAK mutations to tumor initiation and progression remains unclear. Here, we identify p21-activated serine/threonine kinase 5 (PAK5) as the most frequently altered PAK family member in human melanoma. More than 60% of melanoma-associated PAK5 gene alterations are missense mutations, and distribution of these variants throughout the protein coding sequence make it difficult to distinguish oncogenic drivers from passengers. To address this issue, we stably introduced the five most common melanoma-associated PAK5 missense mutations into human immortalized primary melanocytes (hMELTs). While expression of these mutants did not promote single-cell migration or induce temozolomide resistance, a subset of variants drove aberrant melanocyte proliferation. These mitogenic mutants, PAK5 S364L and D421N, clustered within an unstructured, serine-rich domain of the protein and inappropriately activated ERK and PKA through kinase-independent and -dependent mechanisms, respectively. Together, our findings establish the ability of mutant PAK5 to enhance PKA and MAPK signaling in melanocytes and localize the engagement of mitogenic pathways to a serine-rich region of PAK5.
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Affiliation(s)
- Kyle M LaPak
- Department of Molecular Genetics, The Ohio State University, Columbus, OH, USA
| | - Dennis C Vroom
- Department of Molecular Genetics, The Ohio State University, Columbus, OH, USA
| | - Ayush A Garg
- Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH, USA
| | - Xiangnan Guan
- Department of Molecular Genetics, The Ohio State University, Columbus, OH, USA
| | - John L Hays
- Division of Medical Oncology, Department of Internal Medicine, The Ohio State University, Columbus, OH, USA
| | - Jonathan W Song
- Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH, USA
| | - Christin E Burd
- Department of Molecular Genetics, The Ohio State University, Columbus, OH, USA.,Department of Cancer Biology and Genetics, The Ohio State University, Columbus, OH, USA
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18
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Diggins NL, Kang H, Weaver A, Webb DJ. α5β1 integrin trafficking and Rac activation are regulated by APPL1 in a Rab5-dependent manner to inhibit cell migration. J Cell Sci 2018; 131:jcs.207019. [PMID: 29361527 DOI: 10.1242/jcs.207019] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 01/09/2018] [Indexed: 01/04/2023] Open
Abstract
Cell migration is a tightly coordinated process that requires the spatiotemporal regulation of many molecular components. Because adaptor proteins can serve as integrators of cellular events, they are being increasingly studied as regulators of cell migration. The adaptor protein containing a pleckstrin-homology (PH) domain, phosphotyrosine binding (PTB) domain, and leucine zipper motif 1 (APPL1) is a 709 amino acid endosomal protein that plays a role in cell proliferation and survival as well as endosomal trafficking and signaling. However, its function in regulating cell migration is poorly understood. Here, we show that APPL1 hinders cell migration by modulating both trafficking and signaling events controlled by Rab5 in cancer cells. APPL1 decreases internalization and increases recycling of α5β1 integrin, leading to higher levels of α5β1 integrin at the cell surface that hinder adhesion dynamics. Furthermore, APPL1 decreases the activity of the GTPase Rac and its effector PAK, which in turn regulate cell migration. Thus, we demonstrate a novel role for the interaction between APPL1 and Rab5 in governing crosstalk between signaling and trafficking pathways on endosomes to affect cancer cell migration.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Nicole L Diggins
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232, USA
| | - Hakmook Kang
- Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Alissa Weaver
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.,Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.,Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Donna J Webb
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232, USA.,Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.,Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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19
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Gugliandolo A, Diomede F, Cardelli P, Bramanti A, Scionti D, Bramanti P, Trubiani O, Mazzon E. Transcriptomic analysis of gingival mesenchymal stem cells cultured on 3D bioprinted scaffold: A promising strategy for neuroregeneration. J Biomed Mater Res A 2017; 106:126-137. [PMID: 28879677 DOI: 10.1002/jbm.a.36213] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 08/02/2017] [Accepted: 08/22/2017] [Indexed: 01/01/2023]
Abstract
The combined approach of mesenchymal stem cells (MSCs) and scaffolds has been proposed as a potential therapeutic tool for the treatment of neurodegenerative diseases. Indeed, even if MSCs can promote neuronal regeneration, replacing lost neurons or secreting neurotrophic factors, many limitations still exist for their application in regenerative medicine, including the low survival and differentiation rate. The scaffolds, by mimicking the endogenous microenvironment, have shown to promote cell survival, proliferation, and differentiation. In this work, gingival mesenchymal stem cells (GMSCs), isolated from healthy donors, were expanded in vitro, by culturing them adherent in plastic dishes (CTR-GMSCs) or on a poly(lactic acid) scaffold (SC-GMSCs). In order to evaluate the survival and the neurogenic differentiation potential, we performed a comparative transcriptomic analysis between CTR-GMSCs and SC-GMSCs by next generation sequencing. We found that SC-GMSCs showed an increased expression of neurogenic and prosurvival genes. In particular, genes involved in neurotrophin signaling and PI3K/Akt pathways were upregulated. On the contrary, proapoptotic and negative regulator of neuronal growth genes were downregulated. Moreover, nestin and GAP-43 protein levels increased in SC-GMSCs, confirming the neurogenic commitment of these cells. In conclusion, the scaffold, providing a trophic support for MSCs, may promote GMSCs differentiation toward a neuronal phenotype and survival. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 126-137, 2018.
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Affiliation(s)
- Agnese Gugliandolo
- IRCCS Centro Neurolesi "Bonino-Pulejo," Via Provinciale Palermo, Contrada Casazza, 98124 Messina, Italy
| | - Francesca Diomede
- Stem Cells and Regenerative Medicine Laboratory, Department of Medical, Oral and Biotechnological Sciences, University "G. D'Annunzio," Chieti-Pescara, via dei Vestini, 31, 66100, Chieti, Italy
| | - Paolo Cardelli
- Stem Cells and Regenerative Medicine Laboratory, Department of Medical, Oral and Biotechnological Sciences, University "G. D'Annunzio," Chieti-Pescara, via dei Vestini, 31, 66100, Chieti, Italy
| | - Alessia Bramanti
- IRCCS Centro Neurolesi "Bonino-Pulejo," Via Provinciale Palermo, Contrada Casazza, 98124 Messina, Italy.,Institute of Applied Science and Intelligent Systems "ISASI Eduardo Caianiello,", National Research Council of Italy, Messina, Italy
| | - Domenico Scionti
- IRCCS Centro Neurolesi "Bonino-Pulejo," Via Provinciale Palermo, Contrada Casazza, 98124 Messina, Italy
| | - Placido Bramanti
- IRCCS Centro Neurolesi "Bonino-Pulejo," Via Provinciale Palermo, Contrada Casazza, 98124 Messina, Italy
| | - Oriana Trubiani
- Stem Cells and Regenerative Medicine Laboratory, Department of Medical, Oral and Biotechnological Sciences, University "G. D'Annunzio," Chieti-Pescara, via dei Vestini, 31, 66100, Chieti, Italy
| | - Emanuela Mazzon
- IRCCS Centro Neurolesi "Bonino-Pulejo," Via Provinciale Palermo, Contrada Casazza, 98124 Messina, Italy
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20
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Fang X, Li S, Han Q, Zhao Y, Gao J, Yan J, Luo A. Overexpression cdc42 attenuates isoflurane-induced neurotoxicity in developmental brain of rats. Biochem Biophys Res Commun 2017. [PMID: 28642137 DOI: 10.1016/j.bbrc.2017.06.108] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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21
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The molecular effect of metastasis suppressors on Src signaling and tumorigenesis: new therapeutic targets. Oncotarget 2016; 6:35522-41. [PMID: 26431493 PMCID: PMC4742122 DOI: 10.18632/oncotarget.5849] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 08/15/2015] [Indexed: 02/07/2023] Open
Abstract
A major problem for cancer patients is the metastasis of cancer cells from the primary tumor. This involves: (1) migration through the basement membrane; (2) dissemination via the circulatory system; and (3) invasion into a secondary site. Metastasis suppressors, by definition, inhibit metastasis at any step of the metastatic cascade. Notably, Src is a non-receptor, cytoplasmic, tyrosine kinase, which becomes aberrantly activated in many cancer-types following stimulation of plasma membrane receptors (e.g., receptor tyrosine kinases and integrins). There is evidence of a prominent role of Src in tumor progression-related events such as the epithelial–mesenchymal transition (EMT) and the development of metastasis. However, the precise molecular interactions of Src with metastasis suppressors remain unclear. Herein, we review known metastasis suppressors and summarize recent advances in understanding the mechanisms of how these proteins inhibit metastasis through modulation of Src. Particular emphasis is bestowed on the potent metastasis suppressor, N-myc downstream regulated gene 1 (NDRG1) and its interactions with the Src signaling cascade. Recent studies demonstrated a novel mechanism through which NDRG1 plays a significant role in regulating cancer cell migration by inhibiting Src activity. Moreover, we discuss the rationale for targeting metastasis suppressor genes as a sound therapeutic modality, and we review several examples from the literature where such strategies show promise. Collectively, this review summarizes the essential interactions of metastasis suppressors with Src and their effects on progression of cancer metastasis. Moreover, interesting unresolved issues regarding these proteins as well as their potential as therapeutic targets are also discussed.
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Dbo/Henji Modulates Synaptic dPAK to Gate Glutamate Receptor Abundance and Postsynaptic Response. PLoS Genet 2016; 12:e1006362. [PMID: 27736876 PMCID: PMC5065118 DOI: 10.1371/journal.pgen.1006362] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 09/13/2016] [Indexed: 01/28/2023] Open
Abstract
In response to environmental and physiological changes, the synapse manifests plasticity while simultaneously maintains homeostasis. Here, we analyzed mutant synapses of henji, also known as dbo, at the Drosophila neuromuscular junction (NMJ). In henji mutants, NMJ growth is defective with appearance of satellite boutons. Transmission electron microscopy analysis indicates that the synaptic membrane region is expanded. The postsynaptic density (PSD) houses glutamate receptors GluRIIA and GluRIIB, which have distinct transmission properties. In henji mutants, GluRIIA abundance is upregulated but that of GluRIIB is not. Electrophysiological results also support a GluR compositional shift towards a higher IIA/IIB ratio at henji NMJs. Strikingly, dPAK, a positive regulator for GluRIIA synaptic localization, accumulates at the henji PSD. Reducing the dpak gene dosage suppresses satellite boutons and GluRIIA accumulation at henji NMJs. In addition, dPAK associated with Henji through the Kelch repeats which is the domain essential for Henji localization and function at postsynapses. We propose that Henji acts at postsynapses to restrict both presynaptic bouton growth and postsynaptic GluRIIA abundance by modulating dPAK. To meet various developmental or environmental needs, the communication between pre- and postsynapse can be modulated in different aspects. The release of presynaptic vesicles can be regulated at the steps of docking, membrane fusion and endocytosis. Upon receiving neurotransmitter stimuli from presynaptic terminals, postsynaptic cells tune their responses by controlling the abundance of different neurotransmitter receptors at the synaptic membrane. The Drosophila NMJ is a well-defined genetic system to study the function and physiology of synapses. Two types of glutamate receptors (GluRs), IIA and IIB, present at the NMJ, exhibit distinct desensitization kinetics: GluRIIA desensitizes much slower than GluRIIB does, resulting in more ionic influx and larger postsynaptic responses. By altering the ratio of GluRIIA to GluRIIB, muscle cells modulate their responses to presynaptic release efficiently. However, how to regulate this intricate GluRIIA/GluRIIB ratio requires further study. Here, we describe a negative regulation for dPAK, a crucial regulator of GluRIIA localization at the PSD. Henji specifically binds to dPAK near the postsynaptic region and hinders dPAK localization from the PSD. By negatively controlling dPAK levels, synaptic GluRIIA abundance can be restrained within an appropriate range, protecting the synapse from unwanted fluctuations in synaptic strengths or the detriment of excitotoxicity.
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Yang X, Yu D, Ren Y, Wei J, Pan W, Zhou C, Zhou L, Liu Y, Yang M. Integrative Functional Genomics Implicates EPB41 Dysregulation in Hepatocellular Carcinoma Risk. Am J Hum Genet 2016; 99:275-86. [PMID: 27453575 DOI: 10.1016/j.ajhg.2016.05.029] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Accepted: 05/30/2016] [Indexed: 02/05/2023] Open
Abstract
Genome-wide association studies (GWASs) have provided many insights into cancer genetics. However, the molecular mechanisms of many susceptibility SNPs defined by GWASs in cancer heritability and in promoting cancer risk remain elusive. New research strategies, including functional evaluations, are warranted to systematically explore truly causal genetic variants. In this study, we developed an integrative functional genomics methodology to identify cancer susceptibility SNPs in transcription factor-binding sites across the whole genome. Employing integration of functional genomic data from c-Myc cistromics, 1000 Genomes, and the TRANSFAC matrix, we successfully annotated 12 SNPs present in the c-Myc cistrome with properties consistent with modulating c-Myc binding affinity in hepatocellular carcinoma (HCC). After genotyping these 12 SNPs in 1,806 HBV-related HCC case subjects and 1,708 control subjects, we identified a HCC susceptibility SNP, rs157224G>T, in Chinese populations (T allele: odds ratio = 1.64, 95% confidence interval = 1.32-2.02; p = 5.2 × 10(-6)). This polymorphism leads to HCC predisposition through modifying c-Myc-mediated transcriptional regulation of EPB41, with the risk rs157224T allele showing significantly decreased gene expression. Based on cell proliferation, wound healing, and transwell assays as well as the mouse xenograft model, we identify EPB41 as a HCC susceptibility gene in vitro and in vivo. Consistent with this notion, we note that EPB41 expression is significantly decreased in HCC tissue specimens, especially in portal vein metastasis or intrahepatic metastasis, compared to normal tissues. Our results highlight the involvement of regulatory genetic variants in HCC and provide pathogenic insights of this malignancy via a genome-wide approach.
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Peng X, He Q, Li G, Ma J, Zhong TP. Rac1-PAK2 pathway is essential for zebrafish heart regeneration. Biochem Biophys Res Commun 2016; 472:637-42. [PMID: 26966072 DOI: 10.1016/j.bbrc.2016.03.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 03/05/2016] [Indexed: 01/08/2023]
Abstract
P-21 activated kinases, or PAKs, are serine-threonine kinases that play important roles in diverse heart functions include heart development, cardiovascular development and function in a range of models; however, the mechanisms by which PAKs mediate heart regeneration are unknown. Here, we demonstrate that PAK2 and PAK4 expression is induced in cardiomyocytes and vessels, respectively, following zebrafish heart injury. Inhibition of PAK2 and PAK4 using a specific small molecule inhibitor impedes cardiomyocyte proliferation/dedifferentiation and cardiovascular regeneration, respectively. Cdc42 is specifically expressed in the ventricle and may function upstream of PAK2 but not PAK4 under normal conditions and that cardiomyocyte proliferentation during heart regeneration relies on Rac1-mediated activation of Pak2. Our results indicate that PAKs play a key role in heart regeneration.
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Affiliation(s)
- Xiangwen Peng
- State Key Laboratory of Genetic Engineering, Department of Genetics, School of Life Sciences, Fudan University, Shanghai 201203, China
| | - Quanze He
- Center for Reproduction and Genetics, Suzhou Municipal Hospital, Jiangsu 215002, China
| | - Guobao Li
- State Key Laboratory of Genetic Engineering, Department of Genetics, School of Life Sciences, Fudan University, Shanghai 201203, China
| | - Jinmin Ma
- State Key Laboratory of Genetic Engineering, Department of Genetics, School of Life Sciences, Fudan University, Shanghai 201203, China
| | - Tao P Zhong
- State Key Laboratory of Genetic Engineering, Department of Genetics, School of Life Sciences, Fudan University, Shanghai 201203, China; Department of Medicine, Vanderbilt University School of Medicine, TN 37232, USA.
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Liu W, Yue F, Zheng M, Merlot A, Bae DH, Huang M, Lane D, Jansson P, Lui GYL, Richardson V, Sahni S, Kalinowski D, Kovacevic Z, Richardson DR. The proto-oncogene c-Src and its downstream signaling pathways are inhibited by the metastasis suppressor, NDRG1. Oncotarget 2016; 6:8851-74. [PMID: 25860930 PMCID: PMC4496188 DOI: 10.18632/oncotarget.3316] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Accepted: 02/08/2015] [Indexed: 11/25/2022] Open
Abstract
N-myc downstream regulated gene-1 (NDRG1) is a potent metastasis suppressor that plays a key role in regulating signaling pathways involved in mediating cancer cell invasion and migration, including those derived from prostate, colon, etc. However, the mechanisms and molecular targets through which NDRG1 reduces cancer cell invasion and migration, leading to inhibition of cancer metastasis, are not fully elucidated. In this investigation, using NDRG1 over-expression models in three tumor cell-types (namely, DU145, PC3MM and HT29) and also NDRG1 silencing in DU145 and HT29 cells, we reveal that NDRG1 decreases phosphorylation of a key proto-oncogene, cellular Src (c-Src), at a well-characterized activating site (Tyr416). NDRG1-mediated down-regulation of EGFR expression and activation were responsible for the decreased phosphorylation of c-Src (Tyr416). Indeed, NDRG1 prevented recruitment of c-Src to EGFR and c-Src activation. Moreover, NDRG1 suppressed Rac1 activity by modulating phosphorylation of a c-Src downstream effector, p130Cas, and its association with CrkII, which acts as a "molecular switch" to activate Rac1. NDRG1 also affected another signaling molecule involved in modulating Rac1 signaling, c-Abl, which then inhibited CrkII phosphorylation. Silencing NDRG1 increased cell migration relative to the control and inhibition of c-Src signaling using siRNA, or a pharmacological inhibitor (SU6656), prevented this increase. Hence, the role of NDRG1 in decreasing cell migration is, in part, due to its inhibition of c-Src activation. In addition, novel pharmacological agents, which induce NDRG1 expression and are currently under development as anti-metastatic agents, markedly increase NDRG1 and decrease c-Src activation. This study leads to important insights into the mechanism involved in inhibiting metastasis by NDRG1 and how to target these pathways with novel therapeutics.
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Affiliation(s)
- Wensheng Liu
- Department of General Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, P.R.China.,Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Fei Yue
- Department of General Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, P.R.China
| | - Minhua Zheng
- Department of General Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, P.R.China
| | - Angelica Merlot
- Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Dong-Hun Bae
- Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Michael Huang
- Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Darius Lane
- Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Patric Jansson
- Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Goldie Yuan Lam Lui
- Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Vera Richardson
- Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Sumit Sahni
- Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Danuta Kalinowski
- Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Zaklina Kovacevic
- Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Des R Richardson
- Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute, University of Sydney, Sydney, New South Wales 2006, Australia
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26
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p21-activated kinase 2 regulates HSPC cytoskeleton, migration, and homing via CDC42 activation and interaction with β-Pix. Blood 2016; 127:1967-75. [PMID: 26932803 DOI: 10.1182/blood-2016-01-693572] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 02/19/2016] [Indexed: 12/13/2022] Open
Abstract
Cytoskeletal remodeling of hematopoietic stem and progenitor cells (HSPCs) is essential for homing to the bone marrow (BM). The Ras-related C3 botulinum toxin substrate (Rac)/cell division control protein 42 homolog (CDC42) effector p21-activated kinase (Pak2) has been implicated in HSPC homing and engraftment. However, the molecular pathways mediating Pak2 functions in HSPCs are unknown. Here, we demonstrate that both Pak2 kinase activity and its interaction with the PAK-interacting exchange factor-β (β-Pix) are required to reconstitute defective ITALIC! Pak2 (ITALIC! Δ/Δ)HSPC homing to the BM. Pak2 serine/threonine kinase activity is required for stromal-derived factor-1 (SDF1α) chemokine-induced HSPC directional migration, whereas Pak2 interaction with β-Pix is required to regulate the velocity of HSPC migration and precise F-actin assembly. Lack of SDF1α-induced filopodia and associated abnormal cell protrusions seen in ITALIC! Pak2 (ITALIC! Δ/Δ)HSPCs were rescued by wild-type (WT) Pak2 but not by a Pak2-kinase dead mutant (KD). Expression of a β-Pix interaction-defective mutant of Pak2 rescued filopodia formation but led to abnormal F-actin bundles. Although CDC42 has previously been considered an upstream regulator of Pak2, we found a paradoxical decrease in baseline activation of CDC42 in ITALIC! Pak2 (ITALIC! Δ/Δ)HSPCs, which was rescued by expression of Pak2-WT but not by Pak2-KD; defective homing of ITALIC! Pak2-deleted HSPCs was rescued by constitutive active CDC42. These data demonstrate that both Pak2 kinase activity and its interaction with β-Pix are essential for HSPC filopodia formation, cytoskeletal integrity, and homing via activation of CDC42. Taken together, we provide mechanistic insights into the role of Pak2 in HSPC migration and homing.
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The P21-activated kinase expression pattern is different in non-small cell lung cancer and affects lung cancer cell sensitivity to epidermal growth factor receptor tyrosine kinase inhibitors. Med Oncol 2016; 33:22. [PMID: 26820570 DOI: 10.1007/s12032-016-0735-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 01/18/2016] [Indexed: 12/18/2022]
Abstract
Exploring methods for increasing epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) sensitivity has become a major focus in non-small cell lung cancer (NSCLC). Major downstream effectors of the Rho family small guanosine triphosphatases, P21-activated kinases (PAKs) activate the main signaling pathways downstream of EGFR and thus promote tumor cell proliferation. In this study, we explored the expression pattern of phosphorylated PAKs in NSCLC and their potential value as drug targets for treating cancer. The expression and prognostic significance of phosphorylated group I and II PAKs were evaluated in 182 patients with NSCLC. Immunohistochemical analysis revealed low group I PAK expression in normal lung tissues and increased expressed in the cytoplasm, particularly in lung squamous cell carcinoma. Abnormal group I PAK expression was associated with lymph node metastases and high tumor-node-metastases (TNM) stage in NSCLC patients and correlated with poor prognosis. We used group I PAK inhibitor (IPA3) to specifically decrease group I PAK activity in human lung cancer cell lines. Decreased group I PAK activity inhibited cell proliferation and combined IPA3 and EGFR-TKI (gefitinib) treatment inhibited cell proliferation in an obvious manner. Together, our results revealed the PAK expression pattern in NSCLC, and a role for group I PAK in cell proliferation, which provides evidence that decreased PAK activity may have a potential application as a molecular targeted therapy in advanced NSCLC.
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Rho Signaling in Dictyostelium discoideum. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 322:61-181. [DOI: 10.1016/bs.ircmb.2015.10.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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29
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Civiero L, Cirnaru MD, Beilina A, Rodella U, Russo I, Belluzzi E, Lobbestael E, Reyniers L, Hondhamuni G, Lewis PA, Van den Haute C, Baekelandt V, Bandopadhyay R, Bubacco L, Piccoli G, Cookson MR, Taymans JM, Greggio E. Leucine-rich repeat kinase 2 interacts with p21-activated kinase 6 to control neurite complexity in mammalian brain. J Neurochem 2015; 135:1242-56. [PMID: 26375402 PMCID: PMC4715492 DOI: 10.1111/jnc.13369] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Revised: 08/01/2015] [Accepted: 09/04/2015] [Indexed: 12/23/2022]
Abstract
Leucine‐rich repeat kinase 2 (LRRK2) is a causative gene for Parkinson's disease, but the physiological function and the mechanism(s) by which the cellular activity of LRRK2 is regulated are poorly understood. Here, we identified p21‐activated kinase 6 (PAK6) as a novel interactor of the GTPase/ROC domain of LRRK2. p21‐activated kinases are serine‐threonine kinases that serve as targets for the small GTP binding proteins Cdc42 and Rac1 and have been implicated in different morphogenetic processes through remodeling of the actin cytoskeleton such as synapse formation and neuritogenesis. Using an in vivo neuromorphology assay, we show that PAK6 is a positive regulator of neurite outgrowth and that LRRK2 is required for this function. Analyses of post‐mortem brain tissue from idiopathic and LRRK2 G2019S carriers reveal an increase in PAK6 activation state, whereas knock‐out LRRK2 mice display reduced PAK6 activation and phosphorylation of PAK6 substrates. Taken together, these results support a critical role of LRRK2 GTPase domain in cytoskeletal dynamics in vivo through the novel interactor PAK6, and provide a valuable platform to unravel the mechanism underlying LRRK2‐mediated pathophysiology.
We propose p21‐activated kinase 6 (PAK6) as a novel interactor of leucine‐rich repeat kinase 2 (LRRK2), a kinase involved in Parkinson's disease (PD). In health, PAK6 regulates neurite complexity in the brain and LRRK2 is required for its function, (a) whereas PAK6 is aberrantly activated in LRRK2‐linked PD brain (b) suggesting that LRRK2 toxicity is mediated by PAK6.
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Affiliation(s)
- Laura Civiero
- Department of Biology, University of Padova, Padova, Italy
| | | | - Alexandra Beilina
- Laboratory of Neurogenetics, National Institute on Aging/NIH, Bethesda, Maryland, USA
| | - Umberto Rodella
- Department of Biology, University of Padova, Padova, Italy.,Laboratory for Neurobiology and Gene Therapy, KU Leuven, Leuven, Belgium
| | - Isabella Russo
- Department of Biology, University of Padova, Padova, Italy
| | - Elisa Belluzzi
- Department of Biology, University of Padova, Padova, Italy
| | - Evy Lobbestael
- Laboratory for Neurobiology and Gene Therapy, KU Leuven, Leuven, Belgium
| | - Lauran Reyniers
- Laboratory for Neurobiology and Gene Therapy, KU Leuven, Leuven, Belgium
| | - Geshanthi Hondhamuni
- Department of Molecular Neuroscience UCL, Reta Lila Weston Institute of Neurological Studies, Institute of Neurology, London, UK
| | - Patrick A Lewis
- School of Pharmacy, University of Reading, Reading, UK.,Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, UK
| | - Chris Van den Haute
- Laboratory for Neurobiology and Gene Therapy, KU Leuven, Leuven, Belgium.,Leuven Viral Vector Core, KU Leuven, Leuven, Belgium
| | - Veerle Baekelandt
- Laboratory for Neurobiology and Gene Therapy, KU Leuven, Leuven, Belgium
| | - Rina Bandopadhyay
- Department of Molecular Neuroscience UCL, Reta Lila Weston Institute of Neurological Studies, Institute of Neurology, London, UK
| | - Luigi Bubacco
- Department of Biology, University of Padova, Padova, Italy
| | - Giovanni Piccoli
- San Raffaele Science Park and Università Vita-Salute San Raffaele, Milano, Italy
| | - Mark R Cookson
- Laboratory of Neurogenetics, National Institute on Aging/NIH, Bethesda, Maryland, USA
| | - Jean-Marc Taymans
- Laboratory for Neurobiology and Gene Therapy, KU Leuven, Leuven, Belgium
| | - Elisa Greggio
- Department of Biology, University of Padova, Padova, Italy
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30
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Turkel N, Portela M, Poon C, Li J, Brumby AM, Richardson HE. Cooperation of the BTB-Zinc finger protein, Abrupt, with cytoskeletal regulators in Drosophila epithelial tumorigenesis. Biol Open 2015; 4:1024-39. [PMID: 26187947 PMCID: PMC4542289 DOI: 10.1242/bio.012815] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The deregulation of cell polarity or cytoskeletal regulators is a common occurrence in human epithelial cancers. Moreover, there is accumulating evidence in human epithelial cancer that BTB-ZF genes, such as Bcl6 and ZBTB7A, are oncogenic. From our previous studies in the vinegar fly, Drosophila melanogaster, we have identified a cooperative interaction between a mutation in the apico-basal cell polarity regulator Scribble (Scrib) and overexpression of the BTB-ZF protein Abrupt (Ab). Herein, we show that co-expression of ab with actin cytoskeletal regulators, RhoGEF2 or Src64B, in the developing eye-antennal epithelial tissue results in the formation of overgrown amorphous tumours, whereas ab and DRac1 co-expression leads to non-cell autonomous overgrowth. Together with ab, these genes affect the expression of differentiation genes, resulting in tumours locked in a progenitor cell fate. Finally, we show that the expression of two mammalian genes related to ab, Bcl6 and ZBTB7A, which are oncogenes in mammalian epithelial cancers, significantly correlate with the upregulation of cytoskeletal genes or downregulation of apico-basal cell polarity neoplastic tumour suppressor genes in colorectal, lung and other human epithelial cancers. Altogether, this analysis has revealed that upregulation of cytoskeletal regulators cooperate with Abrupt in Drosophila epithelial tumorigenesis, and that high expression of human BTB-ZF genes, Bcl6 and ZBTB7A, shows significant correlations with cytoskeletal and cell polarity gene expression in specific epithelial tumour types. This highlights the need for further investigation of the cooperation between these genes in mammalian systems.
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Affiliation(s)
- Nezaket Turkel
- Cell Cycle and Development Laboratory, Peter MacCallum Cancer Centre, Melbourne, Victoria 3002, Australia
| | - Marta Portela
- Cell Cycle and Development Laboratory, Peter MacCallum Cancer Centre, Melbourne, Victoria 3002, Australia
| | - Carole Poon
- Cell Cycle and Development Laboratory, Peter MacCallum Cancer Centre, Melbourne, Victoria 3002, Australia
| | - Jason Li
- Bioinformatics Core Facility, Peter MacCallum Cancer Centre, Melbourne, Victoria 3002, Australia
| | - Anthony M Brumby
- Cell Cycle and Development Laboratory, Peter MacCallum Cancer Centre, Melbourne, Victoria 3002, Australia
| | - Helena E Richardson
- Cell Cycle and Development Laboratory, Peter MacCallum Cancer Centre, Melbourne, Victoria 3002, Australia Sir Peter MacCallum Department of Oncology, Department of Anatomy and Neuroscience, Department of Biochemistry and Molecular Biology, University of Melbourne, Melbourne, Victoria 3010, Australia School of Molecular Sciences, La Trobe University, Melbourne, Victoria 3086, Australia
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31
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Chen J, Feng WL, Mo WJ, Ding XW, Xie SN. Expression of integrin-binding protein Nischarin in metastatic breast cancer. Mol Med Rep 2015; 12:77-82. [PMID: 25695373 PMCID: PMC4438937 DOI: 10.3892/mmr.2015.3373] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 12/19/2014] [Indexed: 11/24/2022] Open
Abstract
The present study aimed to investigate the expression of Nischarin protein in primary breast cancer (PBC), and to evaluate its role in tumor metastasis. Paired specimens of breast cancer tissues and adjacent normal tissues were surgically obtained from 60 patients with PBC at the Zhejiang Cancer Hospital (Hangzhou, China). Nischarin protein concentrations were determined by an ELISA assay. Breast cancer tissues exhibited a significantly lower concentration of Nischarin (5.86±3.19 ng/ml) compared with that of the adjacent noncancerous tissues (9.25±3.65 ng/ml; P<0.001). Furthermore, cancer tissue from patients with lymph node metastasis had significantly lower levels of Nischarin protein (4.69±2.40 ng/ml) than those of patients without lymph node metastasis (7.04±3.47 ng/ml; P=0.004). There was no significant difference in Nischarin protein expression levels between patients with grade I, II or III PBC (grade I, 5.44±3.57 ng/ml; grade II, 6.42±3.85 ng/ml and grade III, 5.10±1.18 ng/ml; P=0.765). The significant differences in the expression of Nischarin between: i) Cancer tissue and noncancerous tissue and ii) patients with and without lymph node metastasis, suggested that Nischarin may have a significant role in tumor occurrence and metastasis of breast cancer. Nischarin expression may therefore be used as a marker to predict the invasiveness and metastasis of PBC.
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Affiliation(s)
- Jie Chen
- Department of Breast Surgery, Zhejiang Cancer Hospital, Hangzhou, Zhejiang 310022, P.R. China
| | - Wei-Liang Feng
- Department of Breast Surgery, Zhejiang Cancer Hospital, Hangzhou, Zhejiang 310022, P.R. China
| | - Wen-Ju Mo
- Department of Breast Surgery, Zhejiang Cancer Hospital, Hangzhou, Zhejiang 310022, P.R. China
| | - Xiao-Wen Ding
- Department of Breast Surgery, Zhejiang Cancer Hospital, Hangzhou, Zhejiang 310022, P.R. China
| | - Shang-Nao Xie
- Department of Breast Surgery, Zhejiang Cancer Hospital, Hangzhou, Zhejiang 310022, P.R. China
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32
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LAN LEI, HAN YONGSHENG, REN WEI, JIANG JIELONG, WANG PENG, HU ZHAO. Advanced glycation end-products affect the cytoskeletal structure of rat glomerular endothelial cells via the Ras-related C3 botulinum toxin substrate 1 signaling pathway. Mol Med Rep 2015; 11:4321-6. [DOI: 10.3892/mmr.2015.3317] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 12/09/2014] [Indexed: 11/06/2022] Open
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33
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Tian H, Zhou L, Guo W, Wang X. Small GTPase Rac1 and its interaction partner Cla4 regulate polarized growth and pathogenicity in Verticillium dahliae. Fungal Genet Biol 2014; 74:21-31. [PMID: 25475370 DOI: 10.1016/j.fgb.2014.11.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Revised: 11/20/2014] [Accepted: 11/25/2014] [Indexed: 12/21/2022]
Abstract
Rac1 is a small GTPase coordinating diverse cellular functions such as cell polarity, vesicular trafficking, the cell cycle and transcriptional dynamics in many organisms. In this study, we investigate the biological functions of VdRac1, a Rac1 homolog in the soil-borne, wilt-causing fungus Verticillium dahliae. The VdRac1 gene was deleted in a V. dahliae virulence strain Vd8 isolated from a local cotton cultivar. ΔVdrac1 mutants display drastic reduction in colony expansion and form compact, convoluted colonies, show hyper-branching, loss of polarity and ability to penetrate, leading to severely reduced virulence. The p21-activated kinase Cla4 (named as VdCla4 in V. dahliae) null mutants ΔVdcla4 share identical phenotypes with ΔVdrac1. Yeast two-hybrid studies prove that VdCla4 is an effector of VdRac1. Localizations of actin and reactive oxygen species (ROS) in ΔVdrac1 and ΔVdcla4 compared with the corresponding wild-type strain reveal that VdRac1 and VdCla4 play a primary role in polarized hyphal growth via organization of ROS and play only a minor role in the organization of actin. The Vdrac1 and Vdcla4 null mutants are defective in conidiation and trace elements can partially compensate for the defect. Our data demonstrate that VdRac1 regulates polarized growth and pathogenicity by interacting with its effector VdCla4 in V. dahliae.
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Affiliation(s)
- Hui Tian
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Lei Zhou
- The State Key Laboratory of Crop Genetics & Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Wangzhen Guo
- The State Key Laboratory of Crop Genetics & Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Xinyu Wang
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, PR China.
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34
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Itzstein C, Coxon FP, Rogers MJ. The regulation of osteoclast function and bone resorption by small GTPases. Small GTPases 2014; 2:117-130. [PMID: 21776413 DOI: 10.4161/sgtp.2.3.16453] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Revised: 04/22/2011] [Accepted: 05/10/2011] [Indexed: 01/11/2023] Open
Abstract
Osteoclasts are multinucleated cells that are responsible for resorption of bone, and increased activity of these cells is associated with several common bone diseases, including postmenopausal osteoporosis. Upon adhesion to bone, osteoclasts become polarized and reorganise their cytoskeleton and membrane to form unique domains including the sealing zone (SZ), which is a dense ring of F-actin-rich podosomes delimiting the ruffled border (RB), where protons and proteases are secreted to demineralise and degrade the bone matrix, respectively. These processes are dependent on the activity of small GTPases. Rho GTPases are well known to control the organization of F-actin and adhesion structures of different cell types, affecting subsequently their migration. In osteoclasts, RhoA, Rac, Cdc42, RhoU and also Arf6 regulate podosome assembly and their organization into the SZ. By contrast, the formation of the RB involves vesicular trafficking pathways that are regulated by the Rab family of GTPases, in particular lysosomal Rab7. Finally, osteoclast survival is dependent on the activity of Ras GTPases. The correct function of almost all these GTPases is absolutely dependent on post-translational prenylation, which enables them to localize to specific target membranes. Bisphosphonate drugs, which are widely used in the treatment of bone diseases such as osteoporosis, act by preventing the prenylation of small GTPases, resulting in the loss of the SZ and RB and therefore inhibition of osteoclast activity, as well as inducing osteoclast apoptosis. In this review we summarize current understanding of the role of specific prenylated small GTPases in osteoclast polarization, function and survival.
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Affiliation(s)
- Cecile Itzstein
- Musculoskeletal Research Programme; Institute of Medical Sciences; University of Aberdeen; Aberdeen, Scotland UK
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Payne LJ, Eves RL, Jia L, Mak AS. p53 Down regulates PDGF-induced formation of circular dorsal ruffles in rat aortic smooth muscle cells. PLoS One 2014; 9:e108257. [PMID: 25247424 PMCID: PMC4172730 DOI: 10.1371/journal.pone.0108257] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 08/27/2014] [Indexed: 01/15/2023] Open
Abstract
The tumor suppressor, p53, negatively regulates cell migration and invasion in addition to its role in apoptosis, cell cycle regulation and senescence. Here, we study the roles of p53 in PDGF-induced circular dorsal ruffle (CDR) formation in rat aortic smooth muscle (RASM) cells. In primary and immortalized RASM cells, up-regulation of p53 expression or increase in activity with doxorubicin inhibits CDR formation. In contrast, shRNA-knockdown of p53 or inhibition of its activity with pifithrin α promotes CDR formation. p53 acts by up-regulating PTEN expression, which antagonizes Rac and Cdc42 activation. Both lipid and protein phosphatase activities of PTEN are required for maximal suppression of CDR, but the lipid activity clearly plays the dominant role. N-WASP, the downstream effector of Cdc42, is the major positive contributor to CDR formation in RASM, and is an indirect target of p53. The Rac effector, WAVE2, appears to also play a minor role, while WAVE1 has no significant effect in CDR formation. In sum, we propose that p53 suppresses PDGF-induced CDR formation in RASM cells by upregulating PTEN leading mainly to the inhibition of the Cdc42-N-WASP pathway.
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Affiliation(s)
- Laura J. Payne
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Robert L. Eves
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Lilly Jia
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Alan S. Mak
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
- * E-mail:
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Koth AP, Oliveira BR, Parfitt GM, Buonocore JDQ, Barros DM. Participation of group I p21-activated kinases in neuroplasticity. ACTA ACUST UNITED AC 2014; 108:270-7. [PMID: 25174326 DOI: 10.1016/j.jphysparis.2014.08.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 04/25/2014] [Accepted: 08/20/2014] [Indexed: 12/15/2022]
Abstract
PAKs are a family of serine/threonine protein kinases activated by small GTPases of the Rho family, including Rac and Cdc42, and are categorized into group I (isoforms 1, 2 and 3) and group II (isoforms 4, 5 and 6). PAK1 and PAK3 are critically involved in biological mechanisms associated with neurodevelopment, neuroplasticity and maturation of the nervous system, and changes in their activity have been detected in pathological disorders, such as Alzheimer's disease, Huntington's disease and mental retardation. The group I PAKs have been associated with neurological processes due to their involvement in intracellular mechanisms that result in molecular and cellular morphological alterations that promote cytoskeletal outgrowth, increasing the efficiency of synaptic transmission. Their substrates in these processes include other intracellular signaling molecules, such as Raf, Mek and LIMK, as well as other components of the cytoskeleton, such as MLC and FLNa. In this review, we describe the characteristics of group I PAKs, such as their molecular structure, mechanisms of activation and importance in the neurobiological processes involved in synaptic plasticity.
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Affiliation(s)
- André P Koth
- Instituto de Ciências Biológicas (ICB), Programa de Pós-graduação em Ciências Fisiológicas, Fisiologia Animal Comparada, Laboratório de Neurociências, Universidade Federal do Rio Grande (FURG), Av Itália, Km 8, Rio Grande, RS 96203-900, Brazil.
| | - Bruno R Oliveira
- Instituto de Ciências Biológicas (ICB), Programa de Pós-graduação em Ciências Fisiológicas, Fisiologia Animal Comparada, Laboratório de Biologia Molecular, Universidade Federal do Rio Grande (FURG), Av Itália, Km 8, Rio Grande, RS 96203-900, Brazil.
| | - Gustavo M Parfitt
- Instituto de Ciências Biológicas (ICB), Programa de Pós-graduação em Ciências Fisiológicas, Fisiologia Animal Comparada, Laboratório de Neurociências, Universidade Federal do Rio Grande (FURG), Av Itália, Km 8, Rio Grande, RS 96203-900, Brazil.
| | - Juliana de Quadros Buonocore
- Instituto de Ciências Biológicas (ICB), Programa de Pós-graduação em Ciências Fisiológicas, Fisiologia Animal Comparada, Laboratório de Neurociências, Universidade Federal do Rio Grande (FURG), Av Itália, Km 8, Rio Grande, RS 96203-900, Brazil.
| | - Daniela M Barros
- Instituto de Ciências Biológicas (ICB), Programa de Pós-graduação em Ciências Fisiológicas, Fisiologia Animal Comparada, Laboratório de Neurociências, Universidade Federal do Rio Grande (FURG), Av Itália, Km 8, Rio Grande, RS 96203-900, Brazil.
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Moorman VR, Valentine KG, Bédard S, Kasinath V, Dogan J, Love FM, Wand AJ. Dynamic and thermodynamic response of the Ras protein Cdc42Hs upon association with the effector domain of PAK3. J Mol Biol 2014; 426:3520-38. [PMID: 25109462 DOI: 10.1016/j.jmb.2014.07.031] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2014] [Revised: 07/29/2014] [Accepted: 07/31/2014] [Indexed: 01/09/2023]
Abstract
Human cell division cycle protein 42 (Cdc42Hs) is a small, Rho-type guanosine triphosphatase involved in multiple cellular processes through its interactions with downstream effectors. The binding domain of one such effector, the actin cytoskeleton-regulating p21-activated kinase 3, is known as PBD46. Nitrogen-15 backbone and carbon-13 methyl NMR relaxation was measured to investigate the dynamical changes in activated GMPPCP·Cdc42Hs upon PBD46 binding. Changes in internal motion of the Cdc42Hs, as revealed by methyl axis order parameters, were observed not only near the Cdc42Hs-PBD46 interface but also in remote sites on the Cdc42Hs molecule. The binding-induced changes in side-chain dynamics propagate along the long axis of Cdc42Hs away from the site of PBD46 binding with sharp distance dependence. Overall, the binding of the PBD46 effector domain on the dynamics of methyl-bearing side chains of Cdc42Hs results in a modest rigidification, which is estimated to correspond to an unfavorable change in conformational entropy of approximately -10kcalmol(-1) at 298K. A cluster of methyl probes closest to the nucleotide-binding pocket of Cdc42Hs becomes more rigid upon binding of PBD46 and is proposed to slow the catalytic hydrolysis of the γ phosphate moiety. An additional cluster of methyl probes surrounding the guanine ring becomes more flexible on binding of PBD46, presumably facilitating nucleotide exchange mediated by a guanosine exchange factor. In addition, the Rho insert helix, which is located at a site remote from the PBD46 binding interface, shows a significant dynamic response to PBD46 binding.
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Affiliation(s)
- Veronica R Moorman
- Graduate Group in Biochemistry and Molecular Biophysics, Johnson Research Foundation and Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6059, USA
| | - Kathleen G Valentine
- Graduate Group in Biochemistry and Molecular Biophysics, Johnson Research Foundation and Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6059, USA
| | - Sabrina Bédard
- Graduate Group in Biochemistry and Molecular Biophysics, Johnson Research Foundation and Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6059, USA
| | - Vignesh Kasinath
- Graduate Group in Biochemistry and Molecular Biophysics, Johnson Research Foundation and Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6059, USA
| | - Jakob Dogan
- Graduate Group in Biochemistry and Molecular Biophysics, Johnson Research Foundation and Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6059, USA
| | - Fiona M Love
- Graduate Group in Biochemistry and Molecular Biophysics, Johnson Research Foundation and Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6059, USA
| | - A Joshua Wand
- Graduate Group in Biochemistry and Molecular Biophysics, Johnson Research Foundation and Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6059, USA.
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Biro M, Munoz MA, Weninger W. Targeting Rho-GTPases in immune cell migration and inflammation. Br J Pharmacol 2014; 171:5491-506. [PMID: 24571448 PMCID: PMC4282076 DOI: 10.1111/bph.12658] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 02/19/2014] [Accepted: 02/20/2014] [Indexed: 12/28/2022] Open
Abstract
Leukocytes are unmatched migrators capable of traversing barriers and tissues of remarkably varied structural composition. An effective immune response relies on the ability of its constituent cells to infiltrate target sites. Yet, unwarranted mobilization of immune cells can lead to inflammatory diseases and tissue damage ranging in severity from mild to life-threatening. The efficacy and plasticity of leukocyte migration is driven by the precise spatiotemporal regulation of the actin cytoskeleton. The small GTPases of the Rho family (Rho-GTPases), and their immediate downstream effector kinases, are key regulators of cellular actomyosin dynamics and are therefore considered prime pharmacological targets for stemming leukocyte motility in inflammatory disorders. This review describes advances in the development of small-molecule inhibitors aimed at modulating the Rho-GTPase-centric regulatory pathways governing motility, many of which stem from studies of cancer invasiveness. These inhibitors promise the advent of novel treatment options with high selectivity and potency against immune-mediated pathologies.
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Affiliation(s)
- Maté Biro
- Centenary Institute of Cancer Medicine and Cell Biology, Immune Imaging Program, Newtown, NSW, Australia; Sydney Medical School, The University of Sydney, Sydney, NSW, Australia
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Qiu X, Wu K, Lin X, Liu Q, Ye Y, Yu M. Dexamethasone increases Cdc42 expression in human TM-1 cells. Curr Eye Res 2014; 40:290-9. [PMID: 24871483 DOI: 10.3109/02713683.2014.922191] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE Changes in the cytoskeletal organization of the human trabecular meshwork (HTM) is thought to be responsible for primary open-angle glaucoma (POAG) pathologies. Cdc42 is a Rho GTPase; Rho GTPases are important modulatory agents of the cytoskeleton. This study aimed to investigate the effects of dexamethasone (DEX) on Cdc42 in a transformed HTM cell line, TM-1 to understand the molecular pathologies underlying POAG. METHODS TM-1 cells were cultured in vitro. The cultures were treated with DEX at 10(-6) and 10(-7) M for 1-4 days. Cdc42 was silenced using small interfering RNA (siRNA). The expression levels of Cdc42 in the TM-1 cells were measured using reverse transcription (RT)-PCR, western blotting analysis and immunofluorescence. Its downstream effectors, p21-activated kinase phosphorylation (phospho-PAK) and myosin light chain kinase (MLCK), were measured using western blotting analysis. In addition, the F-actin of TM-1 cells was stained using phalloidin. RESULTS The mRNA and protein levels of Cdc42 showed an increase in TM-1 cells with DEX treatment and a decrease in TM-1 cells transfected with Cdc42 siRNA. Moreover, phospho-PAK levels increased, whereas MLCK levels appeared to decrease, with DEX treatment. The F-actin of DEX-treated TM-1 cells displayed a rearrangement. Cdc42 siRNA decreased the expression of Cdc42 and its related proteins, resulting in an attenuation of the effects of DEX on Cdc42 and F-actin organization in TM-1 cells. CONCLUSIONS DEX increases Cdc42 expression in TM-1. This may represent a potential mechanism of DEX-induced HTM cytoskeletal rearrangement.
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Affiliation(s)
- Xuan Qiu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University , Guangzhou , China
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Abstract
The p21 activated kinases (Paks) are well known effector proteins for the Rho GTPases Cdc42 and Rac. The Paks contain 6 members, which fall into 2 families of proteins. The first family consists of Paks 1, 2, and 3, and the second consists of Paks 4, 5, and 6. While some of the Paks are ubiquitously expressed, others have more restrictive tissue specificity. All of them are found in the nervous system. Studies using cell culture, transgenic mice, and knockout mice, have revealed important roles for the Paks in cytoskeletal organization and in many aspects of cell growth and development. This review discusses the basic structures of the Paks, and their roles in cell growth, development, and in cancer.
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Affiliation(s)
- Chetan K Rane
- Susan Lehman Cullman Laboratory for Cancer Research; Department of Chemical Biology; Ernest Mario School of Pharmacy; Rutgers The State University of New Jersey; Piscataway, NJ USA
| | - Audrey Minden
- Susan Lehman Cullman Laboratory for Cancer Research; Department of Chemical Biology; Ernest Mario School of Pharmacy; Rutgers The State University of New Jersey; Piscataway, NJ USA
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The effects of artificial E-cadherin matrix-induced embryonic stem cell scattering on paxillin and RhoA activation via α-catenin. Biomaterials 2013; 35:1797-806. [PMID: 24321709 DOI: 10.1016/j.biomaterials.2013.11.042] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 11/15/2013] [Indexed: 12/28/2022]
Abstract
Mechanical forces have been shown to affect stem cell behavior in a large array of ways. However, our understanding of how these mechanical cues may regulate the behavior of embryonic stem cells (ESCs) remains in its infancy. Here, we aim to clarify the effect of cell scattering on the regulation of Rho family GTPases Rac1 and RhoA as well as paxillin. Allowing ESCs to spread and scatter on a synthetically designed E-cadherin substratum causes phosphorylation of paxillin on consensus phosphorylation sites leading to activation of Rac1 and inactivation of RhoA. By culturing cells in presence of RhoA activator or growing cells to a highly confluent state reverses the effect of cell scattering phenotype. Knockdown of E-cadherin-adapter protein α-catenin revealed that it negatively affects paxillin phosphorylation and up-regulates RhoA activity in compact cellular aggregates. Collectively these results indicate that cell scattering might cause a conformational change of α-catenin limiting its capacity to inhibit paxillin phosphorylation that causes an increase in Rac1 activation and RhoA deactivation. Understanding how synthetically designed extracellular matrix affect ESC signaling through mechanical cues brings a new aspect for stem cell engineers to develop technologies for controlling cell function.
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DeSantiago J, Bare DJ, Ke Y, Sheehan KA, Solaro RJ, Banach K. Functional integrity of the T-tubular system in cardiomyocytes depends on p21-activated kinase 1. J Mol Cell Cardiol 2013; 60:121-8. [PMID: 23612118 PMCID: PMC3679655 DOI: 10.1016/j.yjmcc.2013.04.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Revised: 03/06/2013] [Accepted: 04/12/2013] [Indexed: 12/30/2022]
Abstract
p21-activated kinase (Pak1), a serine-threonine protein kinase, regulates cytoskeletal dynamics and cell motility. Recent experiments further demonstrate that loss of Pak1 results in exaggerated hypertrophic growth in response to pathophysiological stimuli. Calcium (Ca) signaling plays an important role in the regulation of transcription factors involved in hypertrophic remodeling. Here we aimed to determine the role of Pak1 in cardiac excitation-contraction coupling (ECC). Ca transients were recorded in isolated, ventricular myocytes (VMs) from WT and Pak1(-/-) mice. Pak1(-/-) Ca transients had a decreased amplitude, prolonged rise time and delayed recovery time. Di-8-ANNEPS staining revealed a decreased T-tubular density in Pak1(-/-) VMs that coincided with decreased cell capacitance and increased dis-synchrony of Ca induced Ca release (CICR) at individual release units. These changes were not observed in atrial myocytes of Pak1(-/-) mice where the T-tubular system is only sparsely developed. Experiments in cultured rabbit VMs supported a role of Pak1 in the maintenance of the T-tubular structure. T-tubular density in rabbit VMs significantly decreased within 24h of culture. This was accompanied by a decrease of the Ca transient amplitude and a prolongation of its rise time. However, overexpression of constitutively active Pak1 in VMs attenuated the structural remodeling as well as changes in ECC. The results provide significant support for a prominent role of Pak1 activity not only in the functional regulation of ECC but for the structural maintenance of the T-tubular system whose remodeling is an integral feature of hypertrophic remodeling.
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Affiliation(s)
- Jaime DeSantiago
- Center for Cardiovascular Research, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
- Dept. of Medicine, Section of Cardiology, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
| | - Dan J Bare
- Center for Cardiovascular Research, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
- Dept. of Medicine, Section of Cardiology, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
| | - Yunbo Ke
- Center for Cardiovascular Research, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
- Dept. of Physiology and Biophysics, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
| | - Katherine A. Sheehan
- Center for Cardiovascular Research, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
- Dept. of Physiology and Biophysics, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
| | - R. John Solaro
- Center for Cardiovascular Research, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
- Dept. of Physiology and Biophysics, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
| | - Kathrin Banach
- Center for Cardiovascular Research, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
- Dept. of Medicine, Section of Cardiology, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
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Radu M, Rawat SJ, Beeser A, Iliuk A, Tao WA, Chernoff J. ArhGAP15, a Rac-specific GTPase-activating protein, plays a dual role in inhibiting small GTPase signaling. J Biol Chem 2013; 288:21117-21125. [PMID: 23760270 DOI: 10.1074/jbc.m113.459719] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Signaling from small GTPases is a tightly regulated process. In this work we used a protein microarray screen to identify the Rac-specific GAP, ArhGAP15, as a substrate of the Rac effectors Pak1 and Pak2. In addition to serving as a substrate of Pak1/2, we found that ArhGAP15, via its PH domain, bound to these kinases. The association of ArhGAP15 to Pak1/2 resulted in mutual inhibition of GAP and kinase catalytic activity, respectively. Knock-down of ArhGAP15 resulted in activation of Pak1/2, both indirectly, as a result of Rac activation, and directly, as a result of disruption of the ArhGAP15/Pak complex. Our data suggest that ArhGAP15 plays a dual negative role in regulating small GTPase signaling, by acting at the level of the GTPase itself, as well interacting with its effector, Pak kinase.
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Affiliation(s)
- Maria Radu
- From the Cancer Biology Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111
| | - Sonali J Rawat
- the Department of Biochemistry and Molecular Biology, Drexel University, Philadelphia, Pennsylvania 19102, and
| | - Alexander Beeser
- From the Cancer Biology Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111
| | - Anton Iliuk
- the Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907
| | - Weiguo Andy Tao
- the Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907
| | - Jonathan Chernoff
- From the Cancer Biology Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111,.
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Abstract
INTRODUCTION Calpains represent a family of neutral, calcium-dependent proteases, which modify the function of their target proteins by partial truncation. These proteases have been implicated in numerous cell functions, including cell division, proliferation, migration, and death. In the CNS, where µ-calpain and m-calpain are the main calpain isoforms, their activation has been linked to synaptic plasticity as well as to neurodegeneration. This review will focus on the role of calpains in synaptic plasticity and discuss the possibility of developing methods to manipulate calpain activity for therapeutic purposes. AREAS COVERED This review covers the literature showing how calpains are implicated in synaptic plasticity and in a number of conditions associated with learning impairment. The possibility of developing new drugs targeting these enzymes for treating these conditions is discussed. EXPERT OPINION As evidence accumulates that calpain activation participates in neurodegeneration and cancer, there is interest in developing therapeutic approaches using direct or indirect calpain inhibition. In particular, a peptide derived from the calpain truncation site of mGluR1α was shown to decrease neurodegeneration following neonatal hypoxia/ischemia. More selective approaches need to be developed to target calpain or some of its substrates for therapeutic indications associated with deregulation of synaptic plasticity.
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Affiliation(s)
- Michel Baudry
- Western University of Health Sciences, Graduate College of Biomedical Sciences, Basic Medical Sciences, COMP , 309 E 2nd St, Pomona, CA 91766, USA.
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Khoo P, Allan K, Willoughby L, Brumby AM, Richardson HE. In Drosophila, RhoGEF2 cooperates with activated Ras in tumorigenesis through a pathway involving Rho1-Rok-Myosin-II and JNK signalling. Dis Model Mech 2013; 6:661-78. [PMID: 23324326 PMCID: PMC3634650 DOI: 10.1242/dmm.010066] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The Ras oncogene contributes to ≈ 30% of human cancers, but alone is not sufficient for tumorigenesis. In a Drosophila screen for oncogenes that cooperate with an activated allele of Ras (Ras(ACT)) to promote tissue overgrowth and invasion, we identified the GTP exchange factor RhoGEF2, an activator of Rho-family signalling. Here, we show that RhoGEF2 also cooperates with an activated allele of a downstream effector of Ras, Raf (Raf(GOF)). We dissect the downstream pathways through which RhoGEF2 cooperates with Ras(ACT) (and Raf(GOF)), and show that RhoGEF2 requires Rho1, but not Rac, for tumorigenesis. Furthermore, of the Rho1 effectors, we show that RhoGEF2 + Ras (Raf)-mediated tumorigenesis requires the Rho kinase (Rok)-Myosin-II pathway, but not Diaphanous, Lim kinase or protein kinase N. The Rho1-Rok-Myosin-II pathway leads to the activation of Jun kinase (JNK), in cooperation with Ras(ACT). Moreover, we show that activation of Rok or Myosin II, using constitutively active transgenes, is sufficient for cooperative tumorigenesis with Ras(ACT), and together with Ras(ACT) leads to strong activation of JNK. Our results show that Rok-Myosin-II activity is necessary and sufficient for Ras-mediated tumorigenesis. Our observation that activation of Myosin II, which regulates Filamentous actin (F-actin) contractility without affecting F-actin levels, cooperates with Ras(ACT) to promote JNK activation and tumorigenesis, suggests that increased cell contractility is a key factor in tumorigenesis. Furthermore, we show that signalling via the Tumour necrosis factor (TNF; also known as Egr)-ligand-JNK pathway is most likely the predominant pathway that activates JNK upon Rok activation. Overall, our analysis highlights the need for further analysis of the Rok-Myosin-II pathway in cooperation with Ras in human cancers.
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Affiliation(s)
- Peytee Khoo
- Cell Cycle and Development Laboratory, Research Division, Peter MacCallum Cancer Center, Melbourne, Victoria, Australia
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Lynch G, Kramár EA, Babayan AH, Rumbaugh G, Gall CM. Differences between synaptic plasticity thresholds result in new timing rules for maximizing long-term potentiation. Neuropharmacology 2013; 64:27-36. [PMID: 22820276 PMCID: PMC3445784 DOI: 10.1016/j.neuropharm.2012.07.006] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2012] [Revised: 06/28/2012] [Accepted: 07/01/2012] [Indexed: 01/25/2023]
Abstract
The fundamental observation that the temporal spacing of learning episodes plays a critical role in the efficiency of memory encoding has had little effect on either research on long-term potentiation (LTP) or efforts to develop cognitive enhancers. Here we review recent findings describing a spaced trials phenomenon for LTP that appears to be related to recent evidence that plasticity thresholds differ between synapses in the adult hippocampus. Results of tests with one memory enhancing drug suggest that the compound potently facilitates LTP via effects on 'high threshold' synapses and thus alters the temporally extended timing rules. Possible implications of these results for our understanding of LTP substrates, neurobiological contributors to the distributed practice effect, and the consequences of memory enhancement are discussed. This article is part of a Special Issue entitled 'Cognitive Enhancers'.
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Affiliation(s)
- Gary Lynch
- Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697-4260 USA
- Department of Anatomy and Neurobiology, University of California, Irvine, CA 92697-1275 USA
| | - Enikö A. Kramár
- Department of Anatomy and Neurobiology, University of California, Irvine, CA 92697-1275 USA
| | - Alex H. Babayan
- Department of Anatomy and Neurobiology, University of California, Irvine, CA 92697-1275 USA
| | - Gavin Rumbaugh
- Department of Neuroscience, The Scripps Research Institute, Jupiter FL 33458 USA
| | - Christine M. Gall
- Department of Anatomy and Neurobiology, University of California, Irvine, CA 92697-1275 USA
- Department of Neurobiology and Behavior, University of California, Irvine, CA 92697-4450 USA
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Abstract
The Rho family of GTP binding proteins, also commonly referred to as the Rho GTPases, are master regulators of the platelet cytoskeleton and platelet function. These low-molecular-weight or 'small' GTPases act as signaling switches in the spatial and temporal transduction, and amplification of signals from platelet cell surface receptors to the intracellular signaling pathways that drive platelet function. The Rho GTPase family members RhoA, Cdc42 and Rac1 have emerged as key regulators in the dynamics of the actin cytoskeleton in platelets and play key roles in platelet aggregation, secretion, spreading and thrombus formation. Rho GTPase regulators, including GEFs and GAPs and downstream effectors, such as the WASPs, formins and PAKs, may also regulate platelet activation and function. In this review, we provide an overview of Rho GTPase signaling in platelet physiology. Previous studies of Rho GTPases and platelets have had a shared history, as platelets have served as an ideal, non-transformed cellular model to characterize Rho function. Likewise, recent studies of the cell biology of Rho GTPase family members have helped to build an understanding of the molecular regulation of platelet function and will continue to do so through the further characterization of Rho GTPases as well as Rho GAPs, GEFs, RhoGDIs and Rho effectors in actin reorganization and other Rho-driven cellular processes.
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Affiliation(s)
- J E Aslan
- Department of Biomedical Engineering and Cell & Developmental Biology, School of Medicine, Oregon Health & Science University, Portland, OR 97239, USA.
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Raudaskoski M, Kothe E, Fowler TJ, Jung EM, Horton JS. Ras and Rho small G proteins: insights from the Schizophyllum commune genome sequence and comparisons to other fungi. Biotechnol Genet Eng Rev 2012; 28:61-100. [PMID: 22616482 DOI: 10.5661/bger-28-61] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Unlike in animal cells and yeasts, the Ras and Rho small G proteins and their regulators have not received extensive research attention in the case of the filamentous fungi. In an effort to begin to rectify this deficiency, the genome sequence of the basidiomycete mushroom Schizophyllum commune was searched for all known components of the Ras and Rho signalling pathways. The results of this study should provide an impetus for further detailed investigations into their role in polarized hyphal growth, sexual reproduction and fruiting body development. These processes have long been the targets for genetic and cell biological research in this fungus.
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Affiliation(s)
- Marjatta Raudaskoski
- Department of Biology, University of Turku, Biocity A, Tykistökatu 6A, FI-20520 Turku, Finland
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Mao H, Zhang L, Yang Y, Sun J, Deng B, Feng J, Shao Q, Feng A, Song B, Qu X. RhoBTB2 (DBC2) functions as tumor suppressor via inhibiting proliferation, preventing colony formation and inducing apoptosis in breast cancer cells. Gene 2011; 486:74-80. [DOI: 10.1016/j.gene.2011.07.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Revised: 06/10/2011] [Accepted: 07/10/2011] [Indexed: 12/30/2022]
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Billard MJ, Gruver AL, Sempowski GD. Acute endotoxin-induced thymic atrophy is characterized by intrathymic inflammatory and wound healing responses. PLoS One 2011; 6:e17940. [PMID: 21437240 PMCID: PMC3060875 DOI: 10.1371/journal.pone.0017940] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Accepted: 02/18/2011] [Indexed: 11/28/2022] Open
Abstract
Background Productive thymopoiesis is essential for a robust and healthy immune system.
Thymus unfortunately is acutely sensitive to stress resulting in involution
and decreased T cell production. Thymic involution is a complication of many
clinical settings, including infection, malnutrition, starvation, and
irradiation or immunosuppressive therapies. Systemic rises in
glucocorticoids and inflammatory cytokines are known to contribute to thymic
atrophy. Little is known, however, about intrathymic mechanisms that may
actively contribute to thymus atrophy or initiate thymic recovery following
stress events. Methodology/Principal Findings Phenotypic, histologic and transcriptome/pathway analysis of murine thymic
tissue during the early stages of endotoxemia-induced thymic involution was
performed to identify putative mechanisms that drive thymic involution
during stress. Thymus atrophy in this murine model was confirmed by
down-regulation of genes involved in T cell development, cell activation,
and cell cycle progression, correlating with observed phenotypic and
histologic thymus involution. Significant gene changes support the
hypothesis that multiple key intrathymic pathways are differentially
activated during stress-induced thymic involution. These included direct
activation of thymus tissue by LPS through TLR signaling, local expression
of inflammatory cytokines, inhibition of T cell signaling, and induction of
wound healing/tissue remodeling. Conclusions/Significance Taken together, these observations demonstrated that in addition to the
classic systemic response, a direct intrathymic response to endotoxin
challenge concurrently contributes to thymic involution during endotoxemia.
These findings are a substantial advancement over current understanding of
thymus response to stress and may lead to the development of novel
therapeutic approaches to ameliorate immune deficiency associated with
stress events.
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Affiliation(s)
- Matthew J. Billard
- Department of Biostatistics & Bioinformatics, Duke University Medical
Center, Durham, North Carolina, United States of America
| | - Amanda L. Gruver
- Department of Medicine, Department of Pathology, and the Duke University
Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina,
United States of America
| | - Gregory D. Sempowski
- Department of Medicine, Department of Pathology, and the Duke University
Human Vaccine Institute, Duke University Medical Center, Durham, North Carolina,
United States of America
- * E-mail:
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