Role of Yap1 in adult neural stem cell activation

Most adult hippocampal neural stem cells (NSCs) remain quiescent with only a minor portion undergoing active proliferation and neurogenesis. The molecular mechanisms that trigger eventually the transition from quiescence to activation are still poorly understood. Here, we found the activity of the transcriptional activator Yap1 to be enriched in active NSCs. Genetic deletion of Yap1 led to a significant reduction in the relative proportion of active NSCs supporting a physiological role of Yap1 in regulating the transition from quiescence to activation. Overexpression of wild type Yap1 in adult NSCs did not induce NSC activation suggesting tight upstream control mechanisms, but overexpression of a gain-of-function mutant (Yap1-5SA) elicited cell cycle entry in NSCs and hilar astrocytes. Consistent with a role of Yap1 in NSC activation, single cell RNA sequencing revealed the partial induction of an activated NSC gene expression program. Yet, Yap1-5SA expression also induced Taz and other key components of the Yap/Taz regulon previously identified in glioblastoma stem cell-like cells. Consequently, dysregulated Yap1 activity led to repression of hippocampal neurogenesis, promoting aberrant differentiation instead.

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SLUG and Truncated TAL1 Reduce Glioblastoma Stem Cell Growth Downstream of Notch1 and Define Distinct Vascular Subpopulations in Glioblastoma Multiforme

Cancers ◽

10.3390/cancers13215393 ◽

2021 ◽

Vol 13 (21) ◽

pp. 5393

Author(s):

Sophie Guelfi ◽

Béatrice Orsetti ◽

Virginie Deleuze ◽

Valérie Rigau ◽

Luc Bauchet ◽

...

Keyword(s):

Endothelial Cells ◽

Molecular Mechanisms ◽

Epithelial To Mesenchymal Transition ◽

Growth Factor Receptor ◽

Treatment Resistance ◽

Mesenchymal Transition ◽

Glioblastoma Stem Cell ◽

A Minor

Glioblastomas (GBM) are high-grade brain tumors, containing cells with distinct phenotypes and tumorigenic potentials, notably aggressive and treatment-resistant multipotent glioblastoma stem cells (GSC). The molecular mechanisms controlling GSC plasticity and growth have only partly been elucidated. Contact with endothelial cells and the Notch1 pathway control GSC proliferation and fate. We used three GSC cultures and glioma resections to examine the expression, regulation, and role of two transcription factors, SLUG (SNAI2) and TAL1 (SCL), involved in epithelial to mesenchymal transition (EMT), hematopoiesis, vascular identity, and treatment resistance in various cancers. In vitro, SLUG and a truncated isoform of TAL1 (TAL1-PP22) were strongly upregulated upon Notch1 activation in GSC, together with LMO2, a known cofactor of TAL1, which formed a complex with truncated TAL1. SLUG was also upregulated by TGF-β1 treatment and by co-culture with endothelial cells. In patient samples, the full-length isoform TAL1-PP42 was expressed in all glioma grades. In contrast, SLUG and truncated TAL1 were preferentially overexpressed in GBMs. SLUG and TAL1 are expressed in the tumor microenvironment by perivascular and endothelial cells, respectively, and to a minor extent, by a fraction of epidermal growth factor receptor (EGFR) -amplified GBM cells. Mechanistically, both SLUG and truncated TAL1 reduced GSC growth after their respective overexpression. Collectively, this study provides new evidence for the role of SLUG and TAL1 in regulating GSC plasticity and growth.

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Endometrial Regeneration in Asherman's Syndrome: Clinical and Translational evidence of Stem Cell Therapies

Current Stem Cell Research & Therapy ◽

10.2174/1574888x14666190213100528 ◽

2019 ◽

Vol 14 (6) ◽

pp. 454-459

Author(s):

Xuejing Hou ◽

Ying Liu ◽

Isabelle Streuli ◽

Patrick Dällenbach ◽

Jean Dubuisson ◽

...

Keyword(s):

Stem Cell ◽

Molecular Mechanisms ◽

Uterine Cavity ◽

Stem Cell Therapies ◽

Intrauterine Adhesions ◽

Asherman’S Syndrome ◽

Cell Therapies ◽

Fibrotic Process ◽

Physical Barriers

Asherman’s Syndrome or Intrauterine adhesions is an acquired uterine condition where fibrous scarring forms within the uterine cavity, resulting in reduced menstrual flow, pelvic pain and infertility. Until recently, the molecular mechanisms leading to the formation of fibrosis were poorly understood, and the treatment of Asherman’s syndrome has largely focused on hysteroscopic resection of adhesions, hormonal therapy, and physical barriers. Numerous studies have begun exploring the molecular mechanisms behind the fibrotic process underlying Asherman’s Syndrome as well as the role of stem cells in the regeneration of the endometrium as a treatment modality. The present review offers a summary of available stem cell-based regeneration studies, as well as highlighting current gaps in research.

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Physical Exercise and Cardiac Repair: The Potential Role of Nitric Oxide in Boosting Stem Cell Regenerative Biology

Antioxidants ◽

10.3390/antiox10071002 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1002

Author(s):

Fabiola Marino ◽

Mariangela Scalise ◽

Eleonora Cianflone ◽

Luca Salerno ◽

Donato Cappetta ◽

...

Keyword(s):

Nitric Oxide ◽

Stem Cell ◽

Physical Exercise ◽

Cell Biology ◽

Molecular Mechanisms ◽

Heart Function ◽

Stem Cell Biology ◽

Myocardial Repair ◽

Beneficial Effects

Over the years strong evidence has been accumulated showing that aerobic physical exercise exerts beneficial effects on the prevention and reduction of cardiovascular risk. Exercise in healthy subjects fosters physiological remodeling of the adult heart. Concurrently, physical training can significantly slow-down or even reverse the maladaptive pathologic cardiac remodeling in cardiac diseases, improving heart function. The underlying cellular and molecular mechanisms of the beneficial effects of physical exercise on the heart are still a subject of intensive study. Aerobic activity increases cardiovascular nitric oxide (NO) released mainly through nitric oxidase synthase 3 activity, promoting endothelium-dependent vasodilation, reducing vascular resistance, and lowering blood pressure. On the reverse, an imbalance between increasing free radical production and decreased NO generation characterizes pathologic remodeling, which has been termed the “nitroso-redox imbalance”. Besides these classical evidence on the role of NO in cardiac physiology and pathology, accumulating data show that NO regulate different aspects of stem cell biology, including survival, proliferation, migration, differentiation, and secretion of pro-regenerative factors. Concurrently, it has been shown that physical exercise generates physiological remodeling while antagonizes pathologic remodeling also by fostering cardiac regeneration, including new cardiomyocyte formation. This review is therefore focused on the possible link between physical exercise, NO, and stem cell biology in the cardiac regenerative/reparative response to physiological or pathological load. Cellular and molecular mechanisms that generate an exercise-induced cardioprotective phenotype are discussed in regards with myocardial repair and regeneration. Aerobic training can benefit cells implicated in cardiovascular homeostasis and response to damage by NO-mediated pathways that protect stem cells in the hostile environment, enhance their activation and differentiation and, in turn, translate to more efficient myocardial tissue regeneration. Moreover, stem cell preconditioning by and/or local potentiation of NO signaling can be envisioned as promising approaches to improve the post-transplantation stem cell survival and the efficacy of cardiac stem cell therapy.

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The role of heredity in cancer.

Journal of Clinical Oncology ◽

10.1200/jco.1989.7.4.527 ◽

1989 ◽

Vol 7 (4) ◽

pp. 527-540 ◽

Cited By ~ 19

Author(s):

E G Levine ◽

R A King ◽

C D Bloomfield

Keyword(s):

Molecular Mechanisms ◽

Familial Cancer ◽

Tumor Development ◽

Future Research ◽

Minor Role ◽

Research Activity ◽

Environmental Interactions ◽

Future Research Directions ◽

A Minor

Heredity is generally felt to play a minor role in the development of cancer. This review critically examines this assumption. Topics discussed include evidence for heritable predisposition in animals and humans; the potential importance of genetic-environmental interactions; approaches that are being used to successfully locate genes responsible for heritable predisposition; comparability of genetic findings among heritable and corresponding sporadic malignancies; and future research directions. Breast, colon, and lung cancer are used to exemplify clinical and research activity in familial cancer; clinical phenotypes, segregation and linkage analyses, models for environmental interactions with inherited traits, and molecular mechanisms of tumor development are discussed. We conclude that the contribution of heredity to the cancer burden is greater than generally accepted, and that study of heritable predisposition will continue to reveal carcinogenic mechanisms important to the development of all cancers.

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Structure, Function, Involvement in Diseases and Targeting of 14-3-3 Proteins: An Update

Current Medicinal Chemistry ◽

10.2174/0929867324666170426095015 ◽

2018 ◽

Vol 25 (1) ◽

pp. 5-21 ◽

Cited By ~ 25

Author(s):

Ylenia Cau ◽

Daniela Valensin ◽

Mattia Mori ◽

Sara Draghi ◽

Maurizio Botta

Keyword(s):

Protein Interactions ◽

Molecular Mechanisms ◽

Physiological Role ◽

Specific Protein ◽

Protein Protein Interactions ◽

Cellular Processes ◽

Protein Partners ◽

High Sequence Homology ◽

Small Molecule Modulators

14-3-3 is a class of proteins able to interact with a multitude of targets by establishing protein-protein interactions (PPIs). They are usually found in all eukaryotes with a conserved secondary structure and high sequence homology among species. 14-3-3 proteins are involved in many physiological and pathological cellular processes either by triggering or interfering with the activity of specific protein partners. In the last years, the scientific community has collected many evidences on the role played by seven human 14-3-3 isoforms in cancer or neurodegenerative diseases. Indeed, these proteins regulate the molecular mechanisms associated to these diseases by interacting with (i) oncogenic and (ii) pro-apoptotic proteins and (iii) with proteins involved in Parkinson and Alzheimer diseases. The discovery of small molecule modulators of 14-3-3 PPIs could facilitate complete understanding of the physiological role of these proteins, and might offer valuable therapeutic approaches for these critical pathological states.

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Potential Role of Adult Hippocampal Neurogenesis in Traumatic Brain Injury

Current Medicinal Chemistry ◽

10.2174/0929867328666210923143713 ◽

2021 ◽

Vol 28 ◽

Author(s):

Lucas Alexandre Santos Marzano ◽

Fabyolla Lúcia Macedo de Castro ◽

Caroline Amaral Machado ◽

João Luís Vieira Monteiro de Barros ◽

Thiago Macedo e Cordeiro ◽

...

Keyword(s):

Traumatic Brain Injury ◽

Brain Injury ◽

Clinical Studies ◽

Molecular Mechanisms ◽

Hippocampal Neurogenesis ◽

Cognitive Outcomes ◽

Adult Hippocampal Neurogenesis ◽

The Brain

: Traumatic brain injury (TBI) is a serious cause of disability and death among young and adult individuals, displaying complex pathophysiology including cellular and molecular mechanisms that are not fully elucidated. Many experimental and clinical studies investigated the potential relationship between TBI and the process by which neurons are formed in the brain, known as neurogenesis. Currently, there are no available treatments for TBI’s long-term consequences being the search for novel therapeutic targets, a goal of highest scientific and clinical priority. Some studies evaluated the benefits of treatments aimed at improving neurogenesis in TBI. In this scenario, herein, we reviewed current pre-clinical studies that evaluated different approaches to improving neurogenesis after TBI while achieving better cognitive outcomes, which may consist in interesting approaches for future treatments.

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Role of stem cell factor in somatic–germ cell interactions during prenatal oogenesis

Zygote ◽

10.1017/s0967199400003373 ◽

1996 ◽

Vol 4 (04) ◽

pp. 349-351 ◽

Cited By ~ 6

Author(s):

Massimo De Felici ◽

Anna Di Carlo ◽

Maurizio Pesce

Keyword(s):

Stem Cell ◽

Germ Cells ◽

Stem Cell Factor ◽

Molecular Mechanisms ◽

Primordial Germ Cells ◽

Significant Progress ◽

Proliferation And Differentiation ◽

Complex Events ◽

Mechanisms Of Migration

During embryogenesis germ cells originate from primordial germ cells (PGCs). The development of mammalian PGCs involves a number of complex events (formation and segregation of PGC precursors, PGC migration and proliferation) which lead to the differentiation of oocytes or prospermatogonia (for a review see De Feliciet al., 1992). During recent years developments in methods for isolation, purification and culture of mouse PGCs have led to significant progress in the understanding of molecular mechanisms of migration, proliferation and differentiation of these cells (for reviews see De Felici, 1994; and De Felici & Pesce, 1994a). In this paper we describe the key role played by stem cell factor (SCF) in PGC development and early folliculogenesis.

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Essential Roles for Mef2c in Lymphoid Commitment and B-Cell Function.

Blood ◽

10.1182/blood.v110.11.377.377 ◽

2007 ◽

Vol 110 (11) ◽

pp. 377-377

Author(s):

Sandra Stehling-Sun ◽

Rebecca Jimenez ◽

Andrew Hu ◽

Fernando D. Camargo

Keyword(s):

B Cells ◽

B Cell ◽

Molecular Mechanisms ◽

Muscle Development ◽

Cell Function ◽

Physiological Role ◽

Erythroid Differentiation ◽

Hematopoietic Stem ◽

Interleukin 7

Abstract MEF2 transcription factors are well-established regulators of muscle development. Recently, work in murine models has identified one of these factors, Mef2c, as an important regulator in the pathogenesis and the development of acute myeloid leukemia (AML). However, little is know about the molecular mechanism and physiological role of Mef2c in hematopoiesis. Using conditional gene ablation, we have discovered an unexpected role for MEF2c in hematopoietic stem cells (HSCs), where it is required for pan-lymphoid commitment. Competitive repopulation experiments using Mef2c-null HSCs deleted by means of the Mx1-Cre/poly(IC) approach, revealed completely normal monocytic, granulocytic and erythroid differentiation capacities by mutant cells. Generation and renewal of myeloid progenitors and HSCs was also normal. However, contribution to lymphoid lineages (T-cells, B-cells and natural killer cells) was dramatically reduced. Mef2c-deleted HSCs were able to generate lymphoid primed multipotent progenitors (LMPPs) and expressed normal levels of Flt-3 and the master lymphoid regulator ikaros. However, expression of the interleukin-7 receptor (IL-7R) and the number of phenotypically defined common lymphoid progenitors (CLPs) were substantially reduced. We have found two conserved Mef2c-binding sites in the promoter of the Il-7R gene, indicating that Mef2c could directly regulate Il-7R transcription. This and other potential molecular mechanisms of Mef2c-mediated lymphoid commitment will be discussed. We have also studied the effects of lineage-specific deletion of Mef2c in both myeloid and lymphoid populations. Whereas deletion in myelomonocytic cells using the LysM-Cre strain resulted in no anomalies, B-cell specific ablation with the CD19-Cre line revealed major phenotypical and functional abnormalities. CD19-Cre:Mef2cf/f mice show impaired germinal center formation and reduced antibody production in response to T-cell dependent antigens. In addition Mef2c-null mature B-cells fail to express the mature marker CD23, the low affinity receptor for IgE, which we show is a direct transcriptional target. As a consequence of CD23 reduction, CD19-Cre:Mef2cf/f mice have increased IgE production, thus indicating a potential role of Mef2c in allergic disease. Our work here sheds new light on the molecular mechanisms of lymphopoiesis and identifies MEF2 factors as critical hematopoietic transcriptional regulators.

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