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Mariano V, Kanellopoulos AK, Ricci C, Di Marino D, Borrie SC, Dupraz S, Bradke F, Achsel T, Legius E, Odent S, Billuart P, Bienvenu T, Bagni C. Intellectual Disability and Behavioral Deficits Linked to CYFIP1 Missense Variants Disrupting Actin Polymerization. Biol Psychiatry 2024; 95:161-174. [PMID: 37704042 DOI: 10.1016/j.biopsych.2023.08.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/27/2023] [Accepted: 08/31/2023] [Indexed: 09/15/2023]
Abstract
BACKGROUND 15q11.2 deletions and duplications have been linked to autism spectrum disorder, schizophrenia, and intellectual disability. Recent evidence suggests that dysfunctional CYFIP1 (cytoplasmic FMR1 interacting protein 1) contributes to the clinical phenotypes observed in individuals with 15q11.2 deletion/duplication syndrome. CYFIP1 plays crucial roles in neuronal development and brain connectivity, promoting actin polymerization and regulating local protein synthesis. However, information about the impact of single nucleotide variants in CYFIP1 on neurodevelopmental disorders is limited. METHODS Here, we report a family with 2 probands exhibiting intellectual disability, autism spectrum disorder, spastic tetraparesis, and brain morphology defects and who carry biallelic missense point mutations in the CYFIP1 gene. We used skin fibroblasts from one of the probands, the parents, and typically developing individuals to investigate the effect of the variants on the functionality of CYFIP1. In addition, we generated Drosophila knockin mutants to address the effect of the variants in vivo and gain insight into the molecular mechanism that underlies the clinical phenotype. RESULTS Our study revealed that the 2 missense variants are in protein domains responsible for maintaining the interaction within the wave regulatory complex. Molecular and cellular analyses in skin fibroblasts from one proband showed deficits in actin polymerization. The fly model for these mutations exhibited abnormal brain morphology and F-actin loss and recapitulated the core behavioral symptoms, such as deficits in social interaction and motor coordination. CONCLUSIONS Our findings suggest that the 2 CYFIP1 variants contribute to the clinical phenotype in the probands that reflects deficits in actin-mediated brain development processes.
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Affiliation(s)
- Vittoria Mariano
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland; Department of Human Genetics, KU Leuven, Belgium
| | | | - Carlotta Ricci
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Daniele Di Marino
- Department of Life and Environmental Sciences, New York-Marche Structural Biology Center, Polytechnic University of Marche, Ancona, Italy; Department of Neuroscience, Neuronal Death and Neuroprotection Unit, Mario Negri Institute for Pharmacological Research-IRCCS, Milan, Italy
| | | | - Sebastian Dupraz
- Axonal Growth and Regeneration Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Frank Bradke
- Axonal Growth and Regeneration Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Tilmann Achsel
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Eric Legius
- Department of Human Genetics, KU Leuven, Belgium
| | - Sylvie Odent
- Service de Génétique Clinique, Centre Labellisé pour les Anomalies du Développement Ouest, Centre Hospitalier Universitaire de Rennes, Rennes, France; Institut de Génétique et Développement de Rennes, CNRS, UMR 6290, Université de Rennes, ERN-ITHACA, France
| | - Pierre Billuart
- Institut de Psychiatrie et de Neurosciences de Paris, Institut National de la Santé et de la Recherche Médicale U1266, Université de Paris Cité (UPC), Paris, France
| | - Thierry Bienvenu
- Institut de Psychiatrie et de Neurosciences de Paris, Institut National de la Santé et de la Recherche Médicale U1266, Université de Paris Cité (UPC), Paris, France
| | - Claudia Bagni
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland; Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy.
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Qureshi T, Desale SE, Chidambaram H, Chinnathambi S. Understanding Actin Remodeling in Neuronal Cells Through Podosomes. Methods Mol Biol 2024; 2761:257-266. [PMID: 38427242 DOI: 10.1007/978-1-0716-3662-6_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
Cytoskeletal dysregulation forms an important aspect of many neurodegenerative diseases such as Alzheimer's disease. Cytoskeletal functions require the dynamic activity of the cytoskeletal proteins-actin, tubulin, and the associated proteins. One of such important phenomena is that of actin remodeling, which helps the cell to migrate, navigate, and interact with extracellular materials. Podosomes are complex actin-rich cytoskeletal structures, abundant in proteins that interact and degrade the extracellular matrix, enabling cells to displace and migrate. The formation of podosomes requires extensive actin networks and remodeling. Here we present a novel immunofluorescence-based approach to study actin remodeling in neurons through the medium of podosomes.
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Affiliation(s)
- Tazeen Qureshi
- Neurobiology Group, Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
- Department of Neurochemistry, National Institute of Mental Health and Neuro Sciences (NIMHANS), Institute of National Importance, Bangalore, Karnataka, India
| | - Smita Eknath Desale
- Neurobiology Group, Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
- Department of Neurochemistry, National Institute of Mental Health and Neuro Sciences (NIMHANS), Institute of National Importance, Bangalore, Karnataka, India
| | - Hariharakrishnan Chidambaram
- Neurobiology Group, Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
- Department of Neurochemistry, National Institute of Mental Health and Neuro Sciences (NIMHANS), Institute of National Importance, Bangalore, Karnataka, India
| | - Subashchandrabose Chinnathambi
- Neurobiology Group, Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India.
- Department of Neurochemistry, National Institute of Mental Health and Neuro Sciences (NIMHANS), Institute of National Importance, Bangalore, Karnataka, India.
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Reis LR, Souza Junior DR, Tomasin R, Bruni-Cardoso A, Di Mascio P, Ronsein GE. Citrullination of actin-ligand and nuclear structural proteins, cytoskeleton reorganization and protein redistribution across cellular fractions are early events in ionomycin-induced NETosis. Redox Biol 2023; 64:102784. [PMID: 37356135 DOI: 10.1016/j.redox.2023.102784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 06/07/2023] [Accepted: 06/12/2023] [Indexed: 06/27/2023] Open
Abstract
Neutrophil extracellular traps (NETs) are web-like structures of DNA coated with cytotoxic proteins and histones released by activated neutrophils through a process called NETosis. NETs release occurs through a sequence of highly organized events leading to chromatin expansion and rupture of nuclear and cellular membranes. In calcium ionophore-induced NETosis, the enzyme peptidylargine deiminase 4 (PAD4) mediates chromatin decondensation through histone citrullination, but the biochemical pathways involved in this process are not fully understood. Here we use live-imaging microscopy and proteomic studies of the neutrophil cellular fractions to investigate the early events in ionomycin-triggered NETosis. We found that before ionomycin-stimulated neutrophils release NETs, profound biochemical changes occur in and around their nucleus, such as, cytoskeleton reorganization, nuclear redistribution of actin-remodeling related proteins, and citrullination of actin-ligand and nuclear structural proteins. Ionomycin-stimulated neutrophils rapidly lose their characteristic polymorphic nucleus, and these changes are promptly communicated to the extracellular environment through the secretion of proteins related to immune response. Therefore, our findings revealed key biochemical mediators in the early process that subsequently culminates with nuclear and cell membranes rupture, and extracellular DNA release.
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Affiliation(s)
- Lorenna Rocha Reis
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | | | - Rebeka Tomasin
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - Alexandre Bruni-Cardoso
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - Paolo Di Mascio
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - Graziella Eliza Ronsein
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil.
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Wang M, Chen B, Zhang W, Zhang F, Qiu Y, Lin Y, Yang S. Dematin inhibits glioblastoma malignancy through RhoA-mediated CDKs downregulation and cytoskeleton remodeling. Exp Cell Res 2022; 417:113196. [PMID: 35561787 DOI: 10.1016/j.yexcr.2022.113196] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 04/06/2022] [Accepted: 05/05/2022] [Indexed: 12/24/2022]
Abstract
Glioblastoma multiforme (GBM) is well known as a highly aggressive brain tumor subtype. Here, we show that overexpression (OE) of dematin actin-binding protein (DMTN) inhibits GBM proliferation and invasion by affecting cell cycle regulation and actin remodeling, respectively. RT-qPCR, western blotting, and immunohistochemical (IHC) staining demonstrated a significant reduction in DMTN expression in gliomas, especially in high-grade gliomas (HGG) compared with normal brains, which correlates with worse survival in HGG patients. Functional studies revealed inhibitory effects of DMTN on tumor proliferation and migratory capacities. The attenuation in tumor proliferative ability upon DMTN OE was accompanied by RhoA suppression and CDK1, CDK2, CDK4, and cyclin D1 downregulation, while RhoA rescue restored the proliferative phenotype. Meanwhile, overexpression of DMTN produced profoundly disorganized stress fibers, which led to impaired tumor invasion. Furthermore, DMTN overexpression produced substantial suppression of tumor growth upon subcutaneous and intracranial implantation in mice, and this was accompanied by significantly reduced vinculin expression and Ki67 positivity. Taken together, these findings demonstrate the role of DMTN in regulating GBM cell proliferation, actin cytoskeleton, and cell morphology and identify DMTN as a vital tumor suppressor in GBM progression.
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Affiliation(s)
- Mengying Wang
- Brain Injury Center, Department of Neurosurgery, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, PR China; Shanghai Cancer Institute, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, PR China
| | - Binghong Chen
- Brain Injury Center, Department of Neurosurgery, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, PR China; Department of Neurosurgery, The First Affiliated Hospital of Fujian Medical University, Fuzhou, 350001, PR China
| | - Wenrui Zhang
- Brain Injury Center, Department of Neurosurgery, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, PR China; Shanghai Cancer Institute, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, PR China
| | - Fengchen Zhang
- Department of Neurosurgery, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, PR China
| | - Yongming Qiu
- Brain Injury Center, Department of Neurosurgery, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, PR China
| | - Yingying Lin
- Brain Injury Center, Department of Neurosurgery, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, PR China; Shanghai Cancer Institute, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, PR China.
| | - Shaofeng Yang
- Brain Injury Center, Department of Neurosurgery, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, PR China.
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Mercier V, Boucher G, Devost D, Bourque K, Alikashani A, Beauchamp C, Bitton A, Foisy S, Goyette P, Charron G, Hébert TE, Rioux JD. IBD-associated G protein-coupled receptor 65 variant compromises signalling and impairs key functions involved in inflammation. Cell Signal 2022;:110294. [PMID: 35218908 DOI: 10.1016/j.cellsig.2022.110294] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 02/06/2022] [Accepted: 02/21/2022] [Indexed: 12/11/2022]
Abstract
BACKGROUND AND AIMS Inflammatory bowel diseases (IBD) result in chronic inflammation of the gastrointestinal tract. Genetic studies have shown that the GPR65 gene, as well as its missense coding variant, GPR65*Ile231Leu, is associated with IBD. We aimed to define the signalling and biological pathways downstream of GPR65 activation and evaluate the impact of GPR65*231Leu on these. METHODS We used HEK 293 cells stably expressing GPR65 and deficient for either Gαs, Gαq/11 or Gα12/13, to define GPR65 signalling pathways, IBD patient biopsies and a panel of human tissues, primary immune cells and cell lines to determine biologic context, and genetic modulation of human THP-1-derived macrophages to examine the impact of GPR65 in bacterial phagocytosis and NLRP3 inflammasome activation. RESULTS We confirmed that GPR65 signals via the Gαs pathway, leading to cAMP accumulation. GPR65 can also signal via the Gα12/13 pathway leading to formation of stress fibers, actin remodeling and RhoA activation; all impaired by the IBD-associated GPR65*231Leu allele. Gene expression profiling revealed greater expression of GPR65 in biopsies from inflamed compared to non-inflamed tissues from IBD patients or control individuals, potentially explained by infiltration of inflammatory immune cells. Decreased GPR65 expression in THP-1-derived macrophages leads to impaired bacterial phagocytosis, increased NLRP3 inflammasome activation and IL-1β secretion in response to an inflammatory stimulus. CONCLUSIONS We demonstrate that GPR65 exerts its effects through Gαs- and Gα12/13-mediated pathways, that the IBD-associated GPR65*231Leu allele has compromised interactions with Gα12/13 and that KD of GPR65 leads to impaired bacterial phagocytosis and increased inflammatory signalling via the NLRP3 inflammasome. This work identifies a target for development of small molecule therapies.
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Desale SE, Chinnathambi S. Phosphoinositides signaling modulates microglial actin remodeling and phagocytosis in Alzheimer's disease. Cell Commun Signal 2021; 19:28. [PMID: 33627135 PMCID: PMC7905611 DOI: 10.1186/s12964-021-00715-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 01/26/2021] [Indexed: 12/18/2022] Open
Abstract
Alzheimer's disease is one of the neurodegenerative diseases, characterized by the accumulation of abnormal protein deposits, which disrupts signal transduction in neurons and other glia cells. The pathological protein in neurodegenerative diseases, Tau and amyloid-β contribute to the disrupted microglial signaling pathways, actin cytoskeleton, and cellular receptor expression. The important secondary messenger lipids i.e., phosphatidylinositols are largely affected by protein deposits of amyloid-β in Alzheimer's disease. Phosphatidylinositols are the product of different phosphatidylinositol kinases and the state of phosphorylation at D3, D4, and D5 positions of inositol ring. Phosphatidylinositol 3,4,5-triphosphate (PI 3, 4, 5-P3) involves in phagocytic cup formation, cell polarization, whereas Phosphatidylinositol 4,5-bisphosphate (PI 4, 5-P2)-mediates the process of phagosomes formation and further its fusion with early endosome.. The necessary activation of actin-binding proteins such as Rac, WAVE complex, and ARP2/3 complex for the actin polymerization in the process of phagocytosis, migration is regulated and maintained by PI 3, 4, 5-P3 and PI 4, 5-P2. The ratio and types of fatty acid intake can influence the intracellular secondary lipid messengers along with the cellular content of phaphatidylcholine and phosphatidylethanolamine. The Amyloid-β deposits and extracellular Tau seeds disrupt phosphatidylinositides level and actin cytoskeletal network that hamper microglial-signaling pathways in AD. We hypothesize that being a lipid species intracellular levels of phosphatidylinositol would be regulated by dietary fatty acids. Further we are interested to understand phosphoinositide-based signaling cascades in phagocytosis and actin remodeling. Video Abstract.
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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
| | - Subashchandrabose Chinnathambi
- Neurobiology Group, Division of Biochemical Sciences, CSIR-National Chemical Laboratory (CSIR-NCL), Dr. Homi Bhabha Road, Pune, 411008, India.
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Kunimura K, Miki S, Takashima M, Suzuki JI. S-1-propenylcysteine improves TNF-α-induced vascular endothelial barrier dysfunction by suppressing the GEF-H1/RhoA/Rac pathway. Cell Commun Signal 2021; 19:17. [PMID: 33588881 PMCID: PMC7883441 DOI: 10.1186/s12964-020-00692-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 12/01/2020] [Indexed: 12/23/2022] Open
Abstract
Background Vascular endothelial barrier function is maintained by cell-to-cell junctional proteins and contributes to vascular homeostasis. Various risk factors such as inflammation disrupt barrier function through down-regulation of these proteins and promote vascular diseases such as atherosclerosis. Previous studies have demonstrated that aged garlic extract (AGE) and its sulfur-containing constituents exert the protective effects against several vascular diseases such as atherosclerosis. In this study, we examined whether AGE and its sulfur-containing constituents improve the endothelial barrier dysfunction elicited by a pro-inflammatory cytokine, Tumor-necrosis factor-α (TNF-α), and explored their mode of action on TNF-α signaling pathway. Methods Human umbilical vein endothelial cells (HUVECs) were treated with test substances in the presence of TNF-α for various time periods. The endothelial permeability was measured by using a transwell permeability assay. The localization of cell-to-cell junctional proteins and actin cytoskeletons were visualized by immunostaining. RhoA and Rac activities were assessed by using GTP-binding protein pulldown assay. Gene and protein expression levels of signaling molecules were analyzed by real-time PCR and western blotting, respectively. Results We found that AGE and its major sulfur-containing constituent, S-1-propenylcysteine (S1PC), reduced hyperpermeability elicited by TNF-α in HUVECs. In addition, S1PC inhibited TNF-α-induced production of myosin light chain (MLC) kinase and inactivation of MLC phosphatase through the suppression of the Rac and RhoA signaling pathways, respectively, which resulted in the dephosphorylation of MLC2, a key factor of actin remodeling. Moreover, S1PC inhibited the phosphorylation and activation of guanine nucleotide exchange factor-H1 (GEF-H1), a common upstream key molecule and activator of Rac and RhoA. These effects of S1PC were accompanied by its ability to prevent the disruption of junctional proteins on the cell–cell contact regions and the increase of actin stress fibers induced by TNF-α. Conclusions The present study suggested that AGE and its major constituent, S1PC, improve endothelial barrier disruption through the protection of junctional proteins on plasma membrane.![]() Video abstract
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Affiliation(s)
- Kayo Kunimura
- Central Research Laboratory, Wakunaga Pharmaceutical Co., Ltd., 624 Shimokotachi, Koda-cho, Akitakata-shi, Hiroshima, 739-1195, Japan
| | - Satomi Miki
- Central Research Laboratory, Wakunaga Pharmaceutical Co., Ltd., 624 Shimokotachi, Koda-cho, Akitakata-shi, Hiroshima, 739-1195, Japan
| | - Miyuki Takashima
- Central Research Laboratory, Wakunaga Pharmaceutical Co., Ltd., 624 Shimokotachi, Koda-cho, Akitakata-shi, Hiroshima, 739-1195, Japan
| | - Jun-Ichiro Suzuki
- Central Research Laboratory, Wakunaga Pharmaceutical Co., Ltd., 624 Shimokotachi, Koda-cho, Akitakata-shi, Hiroshima, 739-1195, Japan.
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Nguyen MT, Min KH, Kim D, Park SY, Lee W. CFL2 is an essential mediator for myogenic differentiation in C2C12 myoblasts. Biochem Biophys Res Commun 2020; 533:710-6. [PMID: 33187645 DOI: 10.1016/j.bbrc.2020.11.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 11/05/2020] [Indexed: 12/29/2022]
Abstract
CFL2, a skeletal muscle-specific member of the actin depolymerizing factor/cofilin protein family, is known to be involved in the regulation of actin filament dynamics. Although the impact of CFL2 has been studied in human myopathy, its functional contribution to myogenic differentiation, in terms of its effects on cell proliferation, cell cycle, and myogenic factor modulation, remains largely unknown. Here, we report that CFL2 is required for the myogenic differentiation of C2C12 myoblasts by regulating proliferation and myogenic transcription factors expressions. CFL2 expression was induced during myogenic progression, and its knockdown by siRNA in myoblasts enhanced phalloidin staining, indicating increased filamentous actin formation. Interestingly, CFL2 depletion stimulated cell proliferation and induced a cell cycle shift from G0/G1 to G2/M phases, which are known to inhibit progenitor cell differentiation. CFL2 knockdown markedly downregulated the protein expressions of myogenic transcription factors (MyoD, MyoG, and MEF2C) and thereby impaired the differentiation and myotube formation of C2C12 myoblasts. Collectively, this study highlights the roles played by CFL2 on cell cycle progression and proliferation and suggests a novel regulatory mechanism of myogenic differentiation mediated by CFL2.
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Abstract
Background Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a rare form of infantile-onset leukodystrophy. The disorder is caused primarily by mutations of MLC1 that leads to a series of phenotypic outcomes including vacuolation of myelin and astrocytes, subcortical cysts, brain edema, and macrocephaly. Recent studies have indicated that functional interactions among MLC1, GlialCAM, and ClC-2 channels play key roles in the regulation of neuronal, glial and vascular homeostasis. However, the physiological role of MLC1 in cellular homeostatic communication remains poorly understood. In the present study, we investigated the cellular function of MLC1 and its effects on cell–cell interactions. Methods MLC1-dependent cellular morphology and motility were analyzed by using confocal and live cell imaging technique. Biochemical approaches such as immunoblotting, co-immunoprecipitation, and surface biotinylation were conducted to support data. Results We found that the altered MLC1 expression and localization led to a great alteration in cellular morphology and motility through actin remodeling. MLC1 overexpression induced filopodia formation and suppressed motility. And, MLC1 proteins expressed in patient-derived MLC1 mutants resulted in trapping in the ER although no changes in morphology or motility were observed. Interestingly knockdown of Mlc1 induced Arp3-Cortactin interaction, lamellipodia formation, and increased the membrane ruffling of the astrocytes. These data indicate that subcellular localization of expressed MLC1 at the plasma membrane is critical for changes in actin dynamics through ARP2/3 complex. Thus, our results suggest that misallocation of pathogenic mutant MLC1 may disturbs the stable cell-cell communication and the homeostatic regulation of astrocytes in patients with MLC.
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Affiliation(s)
- Junmo Hwang
- Molecular Physiology and Biophysics Laboratory, Neurovascular Unit Research Group, Korea Brain Research Institute (KBRI), 41062, Daegu, Republic of Korea
| | - Hung M Vu
- Department of New Biology, Daegu Gyeongbuk Institute of Science & Technology (DGIST), 42988, Daegu, Republic of Korea
| | - Min-Sik Kim
- Department of New Biology, Daegu Gyeongbuk Institute of Science & Technology (DGIST), 42988, Daegu, Republic of Korea
| | - Hyun-Ho Lim
- Molecular Physiology and Biophysics Laboratory, Neurovascular Unit Research Group, Korea Brain Research Institute (KBRI), 41062, Daegu, Republic of Korea. .,Department of Brain & Cognitive Sciences, Daegu Gyeongbuk Institute of Science & Technology (DGIST), 42988, Daegu, Republic of Korea.
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Singla B, Lin HP, Ghoshal P, Cherian-Shaw M, Csányi G. PKCδ stimulates macropinocytosis via activation of SSH1-cofilin pathway. Cell Signal 2018; 53:111-121. [PMID: 30261270 DOI: 10.1016/j.cellsig.2018.09.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Revised: 09/19/2018] [Accepted: 09/23/2018] [Indexed: 12/13/2022]
Abstract
Macropinocytosis is an actin-dependent endocytic mechanism mediating internalization of extracellular fluid and associated solutes into cells. The present study was designed to identify the specific protein kinase C (PKC) isoform(s) and downstream effectors regulating actin dynamics during macropinocytosis. We utilized various cellular and molecular biology techniques, pharmacological inhibitors and genetically modified mice to study the signaling mechanisms mediating macropinocytosis in macrophages. The qRT-PCR experiments identified PKCδ as the predominant PKC isoform in macrophages. Scanning electron microscopy and flow cytometry analysis of FITC-dextran internalization demonstrated the functional role of PKCδ in phorbol ester- and hepatocyte growth factor (HGF)-induced macropinocytosis. Western blot analysis demonstrated that phorbol ester and HGF stimulate activation of slingshot phosphatase homolog 1 (SSH1) and induce cofilin Ser-3 dephosphorylation via PKCδ in macrophages. Silencing of SSH1 inhibited cofilin dephosphorylation and macropinocytosis stimulation. Interestingly, we also found that incubation of macrophages with BMS-5, a potent inhibitor of LIM kinase, does not stimulate macropinocytosis. In conclusion, the findings of the present study demonstrate a previously unidentified mechanism by which PKCδ via activation of SSH1 and cofilin dephosphorylation stimulates membrane ruffle formation and macropinocytosis. The results of the present study may contribute to a better understanding of the regulatory mechanisms during macrophage macropinocytosis.
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Affiliation(s)
- Bhupesh Singla
- Vascular Biology Center, 1460 Laney Walker Blvd., Augusta University, Medical College of Georgia, Augusta, GA 30912, USA
| | - Hui-Ping Lin
- Vascular Biology Center, 1460 Laney Walker Blvd., Augusta University, Medical College of Georgia, Augusta, GA 30912, USA
| | - Pushpankur Ghoshal
- Vascular Biology Center, 1460 Laney Walker Blvd., Augusta University, Medical College of Georgia, Augusta, GA 30912, USA
| | - Mary Cherian-Shaw
- Vascular Biology Center, 1460 Laney Walker Blvd., Augusta University, Medical College of Georgia, Augusta, GA 30912, USA
| | - Gábor Csányi
- Vascular Biology Center, 1460 Laney Walker Blvd., Augusta University, Medical College of Georgia, Augusta, GA 30912, USA; Department of Pharmacology and Toxicology, 1460 Laney Walker Blvd., Augusta University, Medical College of Georgia, Augusta, GA 30912, USA.
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Djuzenova CS, Fiedler V, Memmel S, Katzer A, Hartmann S, Krohne G, Zimmermann H, Scholz CJ, Polat B, Flentje M, Sukhorukov VL. Actin cytoskeleton organization, cell surface modification and invasion rate of 5 glioblastoma cell lines differing in PTEN and p53 status. Exp Cell Res 2014; 330:346-357. [PMID: 25149900 DOI: 10.1016/j.yexcr.2014.08.013] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 08/04/2014] [Accepted: 08/06/2014] [Indexed: 11/25/2022]
Abstract
Glioblastoma cells exhibit highly invasive behavior whose mechanisms are not yet fully understood. The present study explores the relationship between the invasion capacity of 5 glioblastoma cell lines differing in p53 and PTEN status, expression of mTOR and several other marker proteins involved in cell invasion, actin cytoskeleton organization and cell morphology. We found that two glioblastoma lines mutated in both p53 and PTEN genes (U373-MG and SNB19) exhibited the highest invasion rates through the Matrigel or collagen matrix. In DK-MG (p53wt/PTENwt) and GaMG (p53mut/PTENwt) cells, F-actin mainly occurred in the numerous stress fibers spanning the cytoplasm, whereas U87-MG (p53wt/PTENmut), U373-MG and SNB19 (both p53mut/PTENmut) cells preferentially expressed F-actin in filopodia and lamellipodia. Scanning electron microscopy confirmed the abundant filopodia and lamellipodia in the PTEN mutated cell lines. Interestingly, the gene profiling analysis revealed two clusters of cell lines, corresponding to the most (U373-MG and SNB19, i.e. p53 and PTEN mutated cells) and less invasive phenotypes. The results of this study might shed new light on the mechanisms of glioblastoma invasion.
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Affiliation(s)
- Cholpon S Djuzenova
- Department of Radiation Oncology, University Hospital, Josef-Schneider-Strasse 11, D-97080 Würzburg, Germany.
| | - Vanessa Fiedler
- Department of Radiation Oncology, University Hospital, Josef-Schneider-Strasse 11, D-97080 Würzburg, Germany
| | - Simon Memmel
- Lehrstuhl für Biotechnologie und Biophysik, Universität Würzburg, Biozentrum Am Hubland, 97070 Würzburg, Germany
| | - Astrid Katzer
- Department of Radiation Oncology, University Hospital, Josef-Schneider-Strasse 11, D-97080 Würzburg, Germany
| | - Susanne Hartmann
- Department of Radiation Oncology, University Hospital, Josef-Schneider-Strasse 11, D-97080 Würzburg, Germany
| | - Georg Krohne
- Elektronenmikroskopie, Biozentrum, Universität Würzburg, Am Hubland, 97070 Würzburg, Germany
| | - Heiko Zimmermann
- Hauptabteilung Biophysik & Kryotechnologie, Fraunhofer-Institut für Biomedizinische Technik, Lehrstuhl für Molekulare und Zelluläre Biotechnologie/Nanotechnologie, Universität des Saarlandes, Ensheimer Strasse 48, 66386 St. Ingbert, Germany
| | - Claus-Jürgen Scholz
- Interdisciplinary Center for Clinical Research, University Hospital, Versbacher Strasse 7, 97078 Würzburg, Germany
| | - Bülent Polat
- Department of Radiation Oncology, University Hospital, Josef-Schneider-Strasse 11, D-97080 Würzburg, Germany
| | - Michael Flentje
- Department of Radiation Oncology, University Hospital, Josef-Schneider-Strasse 11, D-97080 Würzburg, Germany
| | - Vladimir L Sukhorukov
- Lehrstuhl für Biotechnologie und Biophysik, Universität Würzburg, Biozentrum Am Hubland, 97070 Würzburg, Germany
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Doi M, Minematsu H, Kubota Y, Nishiwaki K, Miyamoto M. The novel Rac effector RIN-1 regulates neuronal cell migration and axon pathfinding in C. elegans. Development 2013; 140:3435-44. [PMID: 23900541 DOI: 10.1242/dev.089722] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Cell migration and axon guidance require proper regulation of the actin cytoskeleton in response to extracellular guidance cues. Rho/Rac small GTPases are essential regulators of actin remodeling. Caenorhabditis elegans CED-10 is a Rac1 homolog that is required for various cellular morphological changes and migration events and is under the control of several guidance signaling pathways. There is still considerable uncertainty regarding events following the activation of guidance receptors by extracellular signals and the regulation of actin dynamics based on spatiotemporally restricted Rac activity. Here we show that the VPS9 domain protein RIN-1 acts as a novel effector for CED-10 in C. elegans. The orthologous mammalian Rin1 protein has previously been identified as an effector for Ras GTPase and is now known to function as a guanine nucleotide exchange factor for Rab5 GTPase. We found that RIN-1 specifically binds to the GTP-bound form of CED-10 and that mutations in rin-1 cause significant defects in migration and axon guidance of restricted neuronal cell types including AVM and HSN neurons, in contrast to the various defects observed in ced-10 mutants. Our analyses place RIN-1 in the Slit-Robo genetic pathway that regulates repulsive signaling for dorsoventral axon guidance. In rin-1 mutants, actin accumulated on both the ventral and dorsal sides of the developing HSN neuron, in contrast to its ventral accumulation in wild type. These results strongly suggest that RIN-1 acts as an effector for CED-10/Rac1 and regulates actin remodeling in response to restricted guidance cues.
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Affiliation(s)
- Motomichi Doi
- Biomedical Research Institute, AIST, Tsukuba, Ibaraki 305-8566, Japan.
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Kim YD, Kwon MS, Na BR, Kim HR, Lee HS, Jun CD. Swiprosin-1 Expression Is Up-Regulated through Protein Kinase C-θ and NF-κB Pathway in T Cells. Immune Netw 2013; 13:55-62. [PMID: 23700395 PMCID: PMC3659256 DOI: 10.4110/in.2013.13.2.55] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Revised: 02/15/2013] [Accepted: 02/21/2013] [Indexed: 12/01/2022] Open
Abstract
Swiprosin-1 exhibits the highest expression in CD8+ T cells and immature B cells and has been proposed to play a role in lymphocyte biology through actin remodeling. However, regulation of swiprosin-1 gene expression is poorly understood. Here we report that swiprosin-1 is up-regulated in T cells by PKC pathway. Targeted inhibition of the specific protein kinase C (PKC) isotypes by siRNA revealed that PKC-θ is involved in the expression of swiprosin-1 in the human T cells. In contrast, down-regulation of swiprosin-1 by A23187 or ionomycin suggests that calcium-signaling plays a negative role. Interestingly, swiprosin-1 expression is only reduced by treatment with NF-κB inhibitors but not by NF-AT inhibitor, suggesting that the NF-κB pathway is critical for regulation of swiprosin-1 expression. Collectively, these results suggest that swiprosin-1 is a PKC-θ-inducible gene and that it may modulate the late phase of T cell activation after antigen challenge.
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Affiliation(s)
- Young-Dae Kim
- School of Life Sciences, Immune Synapse Research Center and Cell Dynamics Research Center, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea
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Ramesh TP, Kim YD, Kwon MS, Jun CD, Kim SW. Swiprosin-1 Regulates Cytokine Expression of Human Mast Cell Line HMC-1 through Actin Remodeling. Immune Netw 2009; 9:274-84. [PMID: 20157615 PMCID: PMC2816961 DOI: 10.4110/in.2009.9.6.274] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2009] [Revised: 12/16/2009] [Accepted: 12/21/2009] [Indexed: 01/13/2023] Open
Abstract
Background Swiprosin-1 was identified in human CD8+ lymphocytes, mature B cells and non-lymphonoid tissue. We have recently reported that swiprosin-1 is expressed in mast cells and up-regulated in both in vitro and in vivo. Methods The expression of cytokines and swiprosin-1 were determined by by real time PCR and conventional PCR. Pharmacological inhibitors were treated to investigate potential mechanism of swiprosin-1 in mast cell activation. Actin content was evaluated by confocal microscopy and flow cytometry. Results The swiprosin-1 augmented PMA/A23187-induced expression of cytokines and release of histamine. However, knock-down of swiprosin-1 showed only a modest effect on PMA/A23187-induced cytokine expression, suggesting that swiprosin-1 has gain-of-function characteristics. Swiprosin-1 was found in microvilli-like membrane protrusions and highly co-localized with F-actin. Importantly, either disruption of actin by cytochalasin B or inhibition of PI3 kinase, an enzyme involved in actin remodeling, by wortmannin blocked cytokine expression only in swiprosin-1-overexpressing
cells. Conclusion These results suggest that swiprosin-1 modulates mast cell activation potentially through actin regulation.
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Affiliation(s)
- T P Ramesh
- Department of Life Science, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea
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