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Ugorets V, Mendez PL, Zagrebin D, Russo G, Kerkhoff Y, Kotsaris G, Jatzlau J, Stricker S, Knaus P. Dynamic remodeling of septin structures fine-tunes myogenic differentiation. iScience 2024; 27:110630. [PMID: 39246450 PMCID: PMC11380178 DOI: 10.1016/j.isci.2024.110630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 06/02/2024] [Accepted: 07/29/2024] [Indexed: 09/10/2024] Open
Abstract
Controlled myogenic differentiation is integral to the development, maintenance and repair of skeletal muscle, necessitating precise regulation of myogenic progenitors and resident stem cells. The transformation of proliferative muscle progenitors into multinuclear syncytia involves intricate cellular processes driven by cytoskeletal reorganization. While actin and microtubles have been extensively studied, we illuminate the role of septins, an essential yet still often overlooked cytoskeletal component, in myoblast architecture. Notably, Septin9 emerges as a critical regulator of myoblast differentiation during the initial commitment phase. Knock-down of Septin9 in C2C12 cells and primary mouse myoblasts accelerates the transition from proliferation to committed progenitor transcriptional programs. Furthermore, we unveil significant reorganization and downregulation of Septin9 during myogenic differentiation. Collectively, we propose that filmamentous septin structures and their orchestrated reorganization in myoblasts are part of a temporal regulatory mechanism governing the differentiation of myogenic progenitors. This study sheds light on the dynamic interplay between cytoskeletal components underlying controlled myogenic differentiation.
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Affiliation(s)
- Vladimir Ugorets
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Signal Transduction Group, 14195 Berlin, Germany
| | - Paul-Lennard Mendez
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Signal Transduction Group, 14195 Berlin, Germany
- Max Planck Institute for Molecular Genetics, IMPRS-Biology and Computation, 14195 Berlin, Germany
| | - Dmitrii Zagrebin
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Signal Transduction Group, 14195 Berlin, Germany
| | - Giulia Russo
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - Yannic Kerkhoff
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Bionanointerfaces Group, 14195 Berlin, Germany
| | - Georgios Kotsaris
- Berlin-Brandenburg School for Regenerative Therapies, Charité - Universitätsmedizin Berlin, 13353 Berlin, Germany
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Musculoskeletal Development and Regeneration Group, 14195 Berlin, Germany
| | - Jerome Jatzlau
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Signal Transduction Group, 14195 Berlin, Germany
| | - Sigmar Stricker
- Berlin-Brandenburg School for Regenerative Therapies, Charité - Universitätsmedizin Berlin, 13353 Berlin, Germany
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Musculoskeletal Development and Regeneration Group, 14195 Berlin, Germany
| | - Petra Knaus
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Signal Transduction Group, 14195 Berlin, Germany
- Berlin-Brandenburg School for Regenerative Therapies, Charité - Universitätsmedizin Berlin, 13353 Berlin, Germany
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2
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Ugale A, Shunmugam D, Pimpale LG, Rebhan E, Baccarini M. Signaling proteins in HSC fate determination are unequally segregated during asymmetric cell division. J Cell Biol 2024; 223:e202310137. [PMID: 38874393 PMCID: PMC11178505 DOI: 10.1083/jcb.202310137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 03/21/2024] [Accepted: 05/13/2024] [Indexed: 06/15/2024] Open
Abstract
Hematopoietic stem cells (HSCs) continuously replenish mature blood cells with limited lifespans. To maintain the HSC compartment while ensuring output of differentiated cells, HSCs undergo asymmetric cell division (ACD), generating two daughter cells with different fates: one will proliferate and give rise to the differentiated cells' progeny, and one will return to quiescence to maintain the HSC compartment. A balance between MEK/ERK and mTORC1 pathways is needed to ensure HSC homeostasis. Here, we show that activation of these pathways is spatially segregated in premitotic HSCs and unequally inherited during ACD. A combination of genetic and chemical perturbations shows that an ERK-dependent mechanism determines the balance between pathways affecting polarity, proliferation, and metabolism, and thus determines the frequency of asymmetrically dividing HSCs. Our data identify druggable targets that modulate HSC fate determination at the level of asymmetric division.
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Affiliation(s)
- Amol Ugale
- Department of Microbiology, Max Perutz Labs Vienna, University of Vienna, Immunobiology and Genetics, Vienna, Austria
| | - Dhanlakshmi Shunmugam
- Department of Microbiology, Max Perutz Labs Vienna, University of Vienna, Immunobiology and Genetics, Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna , Vienna, Austria
| | | | - Elisabeth Rebhan
- Department of Microbiology, Max Perutz Labs Vienna, University of Vienna, Immunobiology and Genetics, Vienna, Austria
| | - Manuela Baccarini
- Department of Microbiology, Max Perutz Labs Vienna, University of Vienna, Immunobiology and Genetics, Vienna, Austria
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3
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Jespersen JH, Harazin A, Bohn AB, Christensen A, Lorentzen E, Lorentzen A. Analysis of cortical cell polarity by imaging flow cytometry. J Cell Biochem 2023; 124:1685-1694. [PMID: 37721096 DOI: 10.1002/jcb.30476] [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: 05/26/2023] [Revised: 08/31/2023] [Accepted: 09/06/2023] [Indexed: 09/19/2023]
Abstract
Metastasis is the main cause of cancer-related death and therapies specifically targeting metastasis are highly needed. Cortical cell polarity (CCP) is a prometastatic property of circulating tumor cells affecting their ability to exit blood vessels and form new metastases that constitute a promising point of attack to prevent metastasis. However, conventional fluorescence microscopy on single cells and manual quantification of CCP are time-consuming and unsuitable for screening regulators. In this study, we developed an imaging flow cytometry-based method for high-throughput screening of factors affecting CCP in melanoma cells. The artificial intelligence-supported analysis method we developed is highly reproducible, accurate, and orders of magnitude faster than manual quantification. Additionally, this method is flexible and can be adapted to include additional cellular parameters. In a small-scale pilot experiment using polarity-, cytoskeleton-, or membrane-affecting drugs, we demonstrate that our workflow provides a straightforward and efficient approach for screening factors affecting CCP in cells in suspension and provide insights into the specific function of these drugs in this cellular system. The method and workflow presented here will facilitate large-scale studies to reveal novel cell-intrinsic as well as systemic factors controlling CCP during metastasis.
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Affiliation(s)
- Jesper H Jespersen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Andras Harazin
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Anja B Bohn
- Department of Biomedicine, FACS Core Facility, Aarhus University, Aarhus, Denmark
| | - Anni Christensen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Esben Lorentzen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Anna Lorentzen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
- Department of Biomedicine, Health Bioimaging Core Facility, Aarhus University, Aarhus, Denmark
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4
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Mansell E, Lin DS, Loughran SJ, Milsom MD, Trowbridge JJ. New insight into the causes, consequences, and correction of hematopoietic stem cell aging. Exp Hematol 2023; 125-126:1-5. [PMID: 37433369 DOI: 10.1016/j.exphem.2023.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/30/2023] [Accepted: 07/03/2023] [Indexed: 07/13/2023]
Abstract
Aging of hematopoietic stem cells (HSCs) is characterized by lineage bias, increased clonal expansion, and functional decrease. At the molecular level, aged HSCs typically display metabolic dysregulation, upregulation of inflammatory pathways, and downregulation of DNA repair pathways. Cellular aging of HSCs, driven by cell-intrinsic and cell-extrinsic factors, causes a predisposition to anemia, adaptive immune compromise, myelodys, plasia, and malignancy. Most hematologic diseases are strongly associated with age. But what is the biological foundation for decreased fitness with age? And are there therapeutic windows to resolve age-related hematopoietic decline? These questions were the focus of the International Society for Experimental Hematology (ISEH) New Investigator Committee Fall 2022 Webinar. This review touches on the latest insights from two leading laboratories into inflammatory- and niche-driven stem cell aging and includes speculation on strategies to prevent or correct age-related decline in HSC function.
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Affiliation(s)
- Els Mansell
- Erasmus MC Hematology, Rotterdam, The Netherlands; Division of Molecular Medicine and Gene Therapy, Lund University, Lund, Sweden.
| | - Dawn S Lin
- Heidelberg Institute for Stem Cell Technology and Experimental Medicine (HI-STEM), Heidelberg, Germany; Division of Stem Cells and Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Stephen J Loughran
- Wellcome Trust/MRC Stem Cell Institute, University of Cambridge, Cambridge, England, UK
| | - Michael D Milsom
- Heidelberg Institute for Stem Cell Technology and Experimental Medicine (HI-STEM), Heidelberg, Germany; Division of Experimental Hematology, German Cancer Research Center (DKFZ), Heidelberg, Germany
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5
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Ráduly Z, Szabó L, Dienes B, Szentesi P, Bana ÁV, Hajdú T, Kókai E, Hegedűs C, Csernoch L, Gönczi M. Migration of Myogenic Cells Is Highly Influenced by Cytoskeletal Septin7. Cells 2023; 12:1825. [PMID: 37508490 PMCID: PMC10378681 DOI: 10.3390/cells12141825] [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: 05/30/2023] [Revised: 06/19/2023] [Accepted: 07/07/2023] [Indexed: 07/30/2023] Open
Abstract
Septin7 as a unique member of the GTP binding protein family, is widely expressed in the eukaryotic cells and considered to be essential in the formation of hetero-oligomeric septin complexes. As a cytoskeletal component, Septin7 is involved in many important cellular processes. However, its contribution in striated muscle physiology is poorly described. In skeletal muscle, a highly orchestrated process of migration is crucial in the development of functional fibers and in regeneration. Here, we describe the pronounced appearance of Septin7 filaments and a continuous change of Septin7 protein architecture during the migration of myogenic cells. In Septin7 knockdown C2C12 cultures, the basic parameters of migration are significantly different, and the intracellular calcium concentration change in migrating cells are lower compared to that of scrambled cultures. Using a plant cytokinin, forchlorfenuron, to dampen septin dynamics, the altered behavior of the migrating cells is described, where Septin7-depleted cells are more resistant to the treatment. These results indicate the functional relevance of Septin7 in the migration of myoblasts, implying its contribution to muscle myogenesis and regeneration.
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Affiliation(s)
- Zsolt Ráduly
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
- ELKH-DE Cell Physiology Research Group, University of Debrecen, 4032 Debrecen, Hungary
- Doctoral School of Molecular Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - László Szabó
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
- ELKH-DE Cell Physiology Research Group, University of Debrecen, 4032 Debrecen, Hungary
- Doctoral School of Molecular Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Beatrix Dienes
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Péter Szentesi
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Ágnes Viktória Bana
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Tibor Hajdú
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Endre Kókai
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Csaba Hegedűs
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - László Csernoch
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
- ELKH-DE Cell Physiology Research Group, University of Debrecen, 4032 Debrecen, Hungary
| | - Mónika Gönczi
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
- ELKH-DE Cell Physiology Research Group, University of Debrecen, 4032 Debrecen, Hungary
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6
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Tomasso MR, Padrick SB. BORG family proteins in physiology and human disease. Cytoskeleton (Hoboken) 2023; 80:182-198. [PMID: 37403807 DOI: 10.1002/cm.21768] [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: 12/11/2022] [Revised: 06/21/2023] [Accepted: 06/22/2023] [Indexed: 07/06/2023]
Abstract
The binder of rho GTPases (BORG)/Cdc42 effector proteins (Cdc42EP) family is composed of five Rho GTPase binding proteins whose functions and mechanism of actions are of emerging interest. Here, we review recent findings pertaining to the family as a whole and consider how these change our understanding of cellular organization. Recent studies have implicated BORGs in both fundamental physiology and in human diseases, mainly cancers. An emerging pattern suggests that BORG family members cancer-promoting properties are related to their ability to regulate the cytoskeleton, with many impacting the organization of acto-myosin stress fibers. This is consistent with the broader literature indicating that BORG family members are regulators of both the septin and actin cytoskeleton networks. The exact mechanism through which BORGs modify the cytoskeleton is not clear, but we consider here a few data-supported and speculative possibilities. Finally, we delve into how the Rho GTPase Cdc42 modifies BORG function in cells. This remains open-ended as Cdc42's effects on BORGs appear cell type- and cell state-dependent. Collectively, these data point to the importance of the BORG family and suggest broader themes in their function and regulation.
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Affiliation(s)
- Meagan R Tomasso
- Department of Biochemistry and Molecular Biology, Drexel University, Philadelphia, Pennsylvania, USA
| | - Shae B Padrick
- Department of Biochemistry and Molecular Biology, Drexel University, Philadelphia, Pennsylvania, USA
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7
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K S V Castro D, V D Rosa H, Mendonça DC, Cavini IA, P U Araujo A, Garratt RC. Dissecting the binding interface of the septin polymerization enhancer Borg BD3. J Mol Biol 2023; 435:168132. [PMID: 37121395 DOI: 10.1016/j.jmb.2023.168132] [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: 12/08/2022] [Revised: 04/24/2023] [Accepted: 04/25/2023] [Indexed: 05/02/2023]
Abstract
The molecular basis for septin filament assembly has begun to emerge over recent years. These filaments are essential for many septin functions which depend on their association with biological membranes or components of the cytoskeleton. Much less is known about how septins specifically interact with their binding partners. Here we describe the essential role played by the C-terminal domains in both septin polymerization and their association with the BD3 motif of the Borg family of Cdc42 effector proteins. We provide a detailed description, at the molecular level, of a previously reported interaction between BD3 and the NC-interface between SEPT6 and SEPT7. Upon ternary complex formation, the heterodimeric coiled coil formed by the C-terminal domains of the septins becomes stabilized and filament formation is promoted under conditions of ionic strength/protein concentration which are not normally permissible, likely by favouring hexamers over smaller oligomeric states. This demonstrates that binding partners, such as Borg's, have the potential to control filament assembly/disassembly in vivo in a way which can be emulated in vitro by altering the ionic strength. Experimentally validated models indicate that the BD3 peptide lies antiparallel to the coiled coil and is stabilized by a mixture of polar and apolar contacts. At its center, an LGPS motif, common to all human Borg sequences, interacts with charged residues from both helices of the coiled coil (K368 from SEPT7 and the conserved E354 from SEPT6) suggesting a universal mechanism which governs Borg-septin interactions.
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Affiliation(s)
- Danielle K S V Castro
- São Carlos Institute of Chemistry, University of São Paulo, São Carlos, Brazil; São Carlos Institute of Physics, University of São Paulo, São Carlos, Brazil
| | - Higor V D Rosa
- São Carlos Institute of Physics, University of São Paulo, São Carlos, Brazil
| | - Deborah C Mendonça
- São Carlos Institute of Physics, University of São Paulo, São Carlos, Brazil
| | - Italo A Cavini
- São Carlos Institute of Physics, University of São Paulo, São Carlos, Brazil
| | - Ana P U Araujo
- São Carlos Institute of Physics, University of São Paulo, São Carlos, Brazil
| | - Richard C Garratt
- São Carlos Institute of Physics, University of São Paulo, São Carlos, Brazil.
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8
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Role of a small GTPase Cdc42 in aging and age-related diseases. Biogerontology 2023; 24:27-46. [PMID: 36598630 DOI: 10.1007/s10522-022-10008-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 12/13/2022] [Indexed: 01/05/2023]
Abstract
A small GTPase, Cdc42 is evolutionarily one of the most ancient members of the Rho family, which is ubiquitously expressed and involved in a wide range of fundamental cellular functions. The crucial role of Cdc42 includes regulation of the actin cytoskeleton, cell polarity, morphology and migration, endocytosis and exocytosis, cell cycle, and proliferation in many different cell types. Many studies have provided compelling yet contradicting evidence that Cdc42 dysregulation plays an important role in cellular and tissue aging. Furthermore, Cdc42 is a critical factor in the development and progression of aging-related pathologies, such as neurodegenerative and cardiovascular disorders, diabetes type 2, and aging-related disorders of the joints and bones, and the inhibition of the Cdc42 demonstrates potentially significant therapeutic and anti-aging effects in animal models of aging and disease. However, regulation of Cdc42 expression and activity is very complex and depends on many factors, such as the origin and complexity of the tissues, hormonal status, etc. Therefore, this review is focused on current advances in understanding the underlying cellular and molecular mechanisms associated with Cdc42 activity and regulation of senescence in different cell types since they may provide a foundation for novel therapeutic strategies and targeted drugs to reverse the aging process and treat aging-associated disorders.
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Benoit B, Poüs C, Baillet A. Septins as membrane influencers: direct play or in association with other cytoskeleton partners. Front Cell Dev Biol 2023; 11:1112319. [PMID: 36875762 PMCID: PMC9982393 DOI: 10.3389/fcell.2023.1112319] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 01/23/2023] [Indexed: 02/19/2023] Open
Abstract
The cytoskeleton comprises three polymerizing structures that have been studied for a long time, actin microfilaments, microtubules and intermediate filaments, plus more recently investigated dynamic assemblies like septins or the endocytic-sorting complex required for transport (ESCRT) complex. These filament-forming proteins control several cell functions through crosstalks with each other and with membranes. In this review, we report recent works that address how septins bind to membranes, and influence their shaping, organization, properties and functions, either by binding to them directly or indirectly through other cytoskeleton elements.
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Affiliation(s)
- Béatrice Benoit
- INSERM UMR-S 1193, UFR de Pharmacie, University Paris-Saclay, Orsay, France
| | - Christian Poüs
- INSERM UMR-S 1193, UFR de Pharmacie, University Paris-Saclay, Orsay, France.,Laboratoire de Biochimie-Hormonologie, Hôpital Antoine Béclère, AP-HP, Hôpitaux Universitaires Paris-Saclay, Clamart, France
| | - Anita Baillet
- INSERM UMR-S 1193, UFR de Pharmacie, University Paris-Saclay, Orsay, France
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10
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Menon MB, Gaestel M. Editorial: Emerging Functions of Septins—Volume II. Front Cell Dev Biol 2022; 10:949824. [PMID: 35784463 PMCID: PMC9246257 DOI: 10.3389/fcell.2022.949824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Accepted: 05/31/2022] [Indexed: 11/26/2022] Open
Affiliation(s)
- Manoj B. Menon
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India
- *Correspondence: Manoj B. Menon, ; Matthias Gaestel,
| | - Matthias Gaestel
- Institute for Cell Biochemistry, Hannover Medical School, Hannover, Germany
- *Correspondence: Manoj B. Menon, ; Matthias Gaestel,
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Cellular and Molecular Mechanisms Involved in Hematopoietic Stem Cell Aging as a Clinical Prospect. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:2713483. [PMID: 35401928 PMCID: PMC8993567 DOI: 10.1155/2022/2713483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Revised: 02/28/2022] [Accepted: 03/22/2022] [Indexed: 11/17/2022]
Abstract
There is a hot topic in stem cell research to investigate the process of hematopoietic stem cell (HSC) aging characterized by decreased self-renewal ability, myeloid-biased differentiation, impaired homing, and other abnormalities related to hematopoietic repair function. It is of crucial importance that HSCs preserve self-renewal and differentiation ability to maintain hematopoiesis under homeostatic states over time. Although HSC numbers increase with age in both mice and humans, this cannot compensate for functional defects of aged HSCs. The underlying mechanisms regarding HSC aging have been studied from various perspectives, but the exact molecular events remain unclear. Several cell-intrinsic and cell-extrinsic factors contribute to HSC aging including DNA damage responses, reactive oxygen species (ROS), altered epigenetic profiling, polarity, metabolic alterations, impaired autophagy, Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway, nuclear factor- (NF-) κB pathway, mTOR pathway, transforming growth factor-beta (TGF-β) pathway, and wingless-related integration site (Wnt) pathway. To determine how deficient HSCs develop during aging, we provide an overview of different hallmarks, age-related signaling pathways, and epigenetic modifications in young and aged HSCs. Knowing how such changes occur and progress will help researchers to develop medications and promote the quality of life for the elderly and possibly alleviate age-associated hematopoietic disorders. The present review is aimed at discussing the latest advancements of HSC aging and the role of HSC-intrinsic factors and related events of a bone marrow niche during HSC aging.
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12
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Schuster T, Geiger H. Septins in Stem Cells. Front Cell Dev Biol 2021; 9:801507. [PMID: 34957123 PMCID: PMC8695968 DOI: 10.3389/fcell.2021.801507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 11/24/2021] [Indexed: 12/01/2022] Open
Abstract
Septins were first described in yeast. Due to extensive research in non-yeast cells, Septins are now recognized across all species as important players in the regulation of the cytoskeleton, in the establishment of polarity, for migration, vesicular trafficking and scaffolding. Stem cells are primarily quiescent cells, and this actively maintained quiescent state is critical for proper stem cell function. Equally important though, stem cells undergo symmetric or asymmetric division, which is likely linked to the level of symmetry found in the mother stem cell. Due to the ability to organize barriers and be able to break symmetry in cells, Septins are thought to have a significant impact on organizing quiescence as well as the mode (symmetric vs asymmetric) of stem cell division to affect self-renewal versus differentiation. Mechanisms of regulating mammalian quiescence and symmetry breaking by Septins are though still somewhat elusive. Within this overview article, we summarize current knowledge on the role of Septins in stem cells ranging from yeast to mice especially with respect to quiescence and asymmetric division, with a special focus on hematopoietic stem cells.
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Affiliation(s)
| | - Hartmut Geiger
- Institute of Molecular Medicine, Ulm University, Ulm, Germany
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