RESUMO
BACKGROUND: The formation of stem cell clones enables close contact of stem cells inside. The gap junctions in such clone spheres establish a microenvironment that allows frequent intercellular communication to maintain self-renewal and functions of stem cells. Nevertheless, the essential gap junction protein for molecular signaling in clones is poorly known. METHODS: Primary human airway basal cells (hBCs) were isolated from brushing samples through bronchoscopy and then cultured. A tightly focused femtosecond laser was used to excite the local Ca2+ in an individual cell to initiate an internal Ca2+ wave in a clone to screen gap junction proteins. Immunoflourescence staining and clonogenicity assay were used to evaluate self-renewal and functions. RNA and protein levels were assessed by PCR and Western blot. Air-liquid interface assay was conducted to evaluate the differentiation potential. A Naphthalene injury mouse model was used to assess the regeneration potential. RESULTS: Herein, we identify Connexin 25 (Cx25) dominates intercellular Ca2+ communications in clones of hBCs in vitro to maintain the self-renewal and pluripotency of them. The self-renewal and in vitro differentiation functions and in vivo regeneration potential of hBCs in an airway damage model are both regulated by Cx25. The abnormal expression of Cx25 is validated in several diseases including IPF, Covid-19 and bronchiectasis. CONCLUSION: Cx25 is essential for hBC clones in maintaining self-renewal and functions of hBCs via gap junctions.
Assuntos
Conexinas , Regeneração , Humanos , Animais , Camundongos , Conexinas/metabolismo , Conexinas/genética , Diferenciação Celular , COVID-19/metabolismo , COVID-19/virologia , COVID-19/patologia , Junções Comunicantes/metabolismo , Autorrenovação Celular , Cálcio/metabolismo , Células Cultivadas , SARS-CoV-2/metabolismo , Masculino , Células-Tronco/metabolismo , Células-Tronco/citologiaRESUMO
Stem cell niche is critical for regulating the behavior of stem cells. Drosophila neural stem cells (Neuroblasts, NBs) are encased by glial niche cells closely, but it still remains unclear whether glial niche cells can regulate the self-renewal and differentiation of NBs. Here, we show that ferritin produced by glia, cooperates with Zip13 to transport iron into NBs for the energy production, which is essential to the self-renewal and proliferation of NBs. The knockdown of glial ferritin encoding genes causes energy shortage in NBs via downregulating aconitase activity and NAD+ level, which leads to the low proliferation and premature differentiation of NBs mediated by Prospero entering nuclei. More importantly, ferritin is a potential target for tumor suppression. In addition, the level of glial ferritin production is affected by the status of NBs, establishing a bicellular iron homeostasis. In this study, we demonstrate that glial cells are indispensable to maintain the self-renewal of NBs, unveiling a novel role of the NB glial niche during brain development.
Iron is an essential nutrient for almost all living organisms. For example, iron contributes to the replication of DNA, the generation of energy inside cells, and the transport of oxygen around the body. Iron deficiency is the most common of all nutrient deficiencies, affecting over 40% of children worldwide. This can lead to anemia and also impair how the brain and nervous system develop, potentially resulting in long-lasting cognitive damage, even after the deficiency has been treated. It is poorly understood how iron contributes to the development of the brain and nervous system. In particular, whether and how it supports nerve stem cells (or NSCs for short) which give rise to the various neural types in the mature brain. To investigate, Ma et al. experimentally reduced the levels of ferritin (a protein which stores iron) in the developing brains of fruit fly larvae. This reduction in ferritin led to lower numbers of NSCs and a smaller brain. Unexpectedly, this effect was largest when ferritin levels were reduced in glial cells which support and send signals to NSCs, rather than in the stem cells themselves. Ma et al. then used fluorescence microscopy to confirm that glial cells make and contain a lot of ferritin which can be transported to NSCs. Adding iron supplements to the diet of flies lacking ferritin did not lead to normal numbers of stem cells in the brains of the developing fruit flies, whereas adding compounds that reduce the amount of iron led to lower numbers of stem cells. Together, this suggests that ferritin transports iron from glial cells to the NSCs. Without ferritin and iron, the NSCs could not produce enough energy to divide and make new stem cells. This caused the NSCs to lose the characteristics of stem cells and prematurely turn into other types of neurons or glial cells. Together, these findings show that when iron cannot move from glial cells to NSCs this leads to defects in brain development. Future experiments will have to test whether a similar transport of iron from supporting cells to NSCs also occurs in the developing brains of mammals, and whether this mechanism applies to stem cells in other parts of the body.
Assuntos
Proteínas de Drosophila , Ferritinas , Ferro , Células-Tronco Neurais , Neuroglia , Animais , Células-Tronco Neurais/metabolismo , Neuroglia/metabolismo , Ferro/metabolismo , Ferritinas/metabolismo , Ferritinas/genética , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/genética , Drosophila/metabolismo , Proliferação de Células , Diferenciação Celular , Drosophila melanogaster/metabolismo , Drosophila melanogaster/genética , Autorrenovação CelularRESUMO
Inhalation anesthesia stands as a pivotal modality within clinical anesthesia practices. Beyond its primary anesthetic effects, inhaled anesthetics have non-anesthetic effects, exerting bidirectional influences on the physiological state of the body and disease progression. These effects encompass impaired cognitive function, inhibition of embryonic development, influence on tumor progression, and so forth. For many years, inhaled anesthetics were viewed as inhibitors of stem cell fate regulation. However, there is now a growing appreciation that inhaled anesthetics promote stem cell biological functions and thus are now regarded as a double-edged sword affecting stem cell fate. In this review, the effects of inhaled anesthetics on self-renewal and differentiation of neural stem cells (NSCs), embryonic stem cells (ESCs), and cancer stem cells (CSCs) were summarized. The mechanisms of inhaled anesthetics involving cell cycle, metabolism, stemness, and niche of stem cells were also discussed. A comprehensive understanding of these effects will enhance our comprehension of how inhaled anesthetics impact the human body, thus promising breakthroughs in the development of novel strategies for innovative stem cell therapy approaches.
Assuntos
Anestésicos Inalatórios , Diferenciação Celular , Células-Tronco Neurais , Humanos , Diferenciação Celular/efeitos dos fármacos , Anestésicos Inalatórios/farmacologia , Células-Tronco Neurais/efeitos dos fármacos , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/citologia , Animais , Células-Tronco Embrionárias/efeitos dos fármacos , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Autorrenovação Celular/efeitos dos fármacosRESUMO
Graphene nanoplatelets (UGZ-1004) are emerging as a promising biomaterial in regenerative medicine. This study comprehensively evaluates UGZ-1004, focusing on its physical properties, cytotoxicity, intracellular interactions, and, notably, its effects on mesenchymal stem cells (MSCs). UGZ-1004 was characterized by lateral dimensions and layer counts consistent with ISO standards and demonstrated a high carbon purity of 0.08%. Cytotoxicity assessments revealed that UGZ-1004 is non-toxic to various cell lines, including 3T3 fibroblasts, VERO kidney epithelial cells, BV-2 microglia, and MSCs, in accordance with ISO 10993-5:2020/2023 guidelines. The study focused on MSCs and revealed that UGZ-1004 supports their gene expression alterations related to self-renewal and proliferation. MSCs exposed to UGZ-1004 maintained their characteristic surface markers. Importantly, UGZ-1004 promoted significant upregulation of genes crucial for cell cycle regulation and DNA repair, such as CDK1, CDK2, and MDM2. This gene expression profile suggests that UGZ-1004 can enhance MSC self-renewal capabilities, ensuring robust cellular function and longevity. Moreover, UGZ-1004 exposure led to the downregulation of genes associated with tumor development, including CCND1 and TFDP1, mitigating potential tumorigenic risks. These findings underscore the potential of UGZ-1004 to not only bolster MSC proliferation but also enhance their self-renewal processes, which are critical for effective regenerative therapies. The study highlights the need for continued research into the long-term impacts of graphene nanoplatelets and their application in MSC-based regenerative medicine.
Assuntos
Proliferação de Células , Grafite , Células-Tronco Mesenquimais , Proliferação de Células/efeitos dos fármacos , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/citologia , Animais , Grafite/química , Grafite/farmacologia , Camundongos , Chlorocebus aethiops , Autorrenovação Celular/efeitos dos fármacos , Autorrenovação Celular/genética , Células Vero , Regulação da Expressão Gênica/efeitos dos fármacos , Nanopartículas/química , Linhagem Celular , Nanoestruturas/químicaRESUMO
Human spermatogonial stem cells (SSCs) have significant applications in reproductive medicine and regenerative medicine because of their great plasticity. Nevertheless, it remains unknown about the functions and mechanisms of long non-coding RNA (LncRNA) in regulating the fate determinations of human SSCs. Here we have demonstrated that LncRNA ACVR2B-as1 (activin A receptor type 2B antisense RNA 1) controls the self-renewal and apoptosis of human SSCs by interaction with ALDOA via glycolysis activity. LncRNA ACVR2B-as1 is highly expressed in human SSCs. LncRNA ACVR2B-as1 silencing suppresses the proliferation and DNA synthesis and enhances the apoptosis of human SSCs. Mechanistically, our ChIRP-MS and RIP assays revealed that ACVR2B-as1 interacted with ALDOA in human SSCs. High expression of ACVR2B-as1 enhanced the proliferation, DNA synthesis, and glycolysis of human SSCs but inhibited their apoptosis through up-regulation of ALDOA. Importantly, overexpression of ALDOA counteracted the effect of ACVR2B-as1 knockdown on the aforementioned biological processes. Collectively, these results indicate that ACVR2B-as1 interacts with ALDOA to control the self-renewal and apoptosis of human SSCs by enhancing glycolysis activity. This study is of great significance because it sheds a novel insight into molecular mechanisms underlying the fate decisions of human SSCs and it may offer innovative approaches to address the etiology of male infertility.
Assuntos
Apoptose , Proliferação de Células , Glicólise , RNA Longo não Codificante , Humanos , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Apoptose/genética , Glicólise/genética , Masculino , Proliferação de Células/genética , Receptores de Activinas Tipo II/metabolismo , Receptores de Activinas Tipo II/genética , Espermatogônias/metabolismo , Espermatogônias/citologia , Células-Tronco Germinativas Adultas/metabolismo , Autorrenovação Celular/genética , Células CultivadasRESUMO
Oncogenic mutations are abundant in the tissues of healthy individuals, but rarely form tumours1-3. Yet, the underlying protection mechanisms are largely unknown. To resolve these mechanisms in mouse mammary tissue, we use lineage tracing to map the fate of wild-type and Brca1-/-;Trp53-/- cells, and find that both follow a similar pattern of loss and spread within ducts. Clonal analysis reveals that ducts consist of small repetitive units of self-renewing cells that give rise to short-lived descendants. This offers a first layer of protection as any descendants, including oncogenic mutant cells, are constantly lost, thereby limiting the spread of mutations to a single stem cell-descendant unit. Local tissue remodelling during consecutive oestrous cycles leads to the cooperative and stochastic loss and replacement of self-renewing cells. This process provides a second layer of protection, leading to the elimination of most mutant clones while enabling the minority that by chance survive to expand beyond the stem cell-descendant unit. This leads to fields of mutant cells spanning large parts of the epithelial network, predisposing it for transformation. Eventually, clone expansion becomes restrained by the geometry of the ducts, providing a third layer of protection. Together, these mechanisms act to eliminate most cells that acquire somatic mutations at the expense of driving the accelerated expansion of a minority of cells, which can colonize large areas, leading to field cancerization.
Assuntos
Transformação Celular Neoplásica , Glândulas Mamárias Animais , Mutação , Animais , Feminino , Camundongos , Proteína BRCA1/deficiência , Proteína BRCA1/genética , Proteína BRCA1/metabolismo , Linhagem da Célula/genética , Autorrenovação Celular/genética , Transformação Celular Neoplásica/genética , Células Clonais/citologia , Células Clonais/metabolismo , Células Clonais/patologia , Glândulas Mamárias Animais/citologia , Glândulas Mamárias Animais/patologia , Glândulas Mamárias Animais/metabolismo , Proteína Supressora de Tumor p53/deficiência , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Ciclo Estral , Células-Tronco/citologia , Células-Tronco/metabolismo , Células-Tronco/patologiaRESUMO
Histone acetyltransferases KAT2A and KAT2B are paralogs highly expressed in the intestinal epithelium, but their functions are not well understood. In this study, double knockout of murine Kat2 genes in the intestinal epithelium was lethal, resulting in robust activation of interferon signaling and interferon-associated phenotypes including the loss of intestinal stem cells. Use of pharmacological agents and sterile organoid cultures indicated a cell-intrinsic double-stranded RNA trigger for interferon signaling. Acetyl-proteomics and sequencing of immunoprecipitated double-stranded RNA were used to interrogate the mechanism behind this response, which identified mitochondria-encoded double-stranded RNA as the source of intrinsic interferon signaling. Kat2a and Kat2b therefore play an essential role in regulating mitochondrial functions and maintaining intestinal health.
Assuntos
Histona Acetiltransferases , Interferons , Camundongos Knockout , RNA de Cadeia Dupla , Transdução de Sinais , Células-Tronco , Animais , RNA de Cadeia Dupla/metabolismo , Camundongos , Células-Tronco/metabolismo , Células-Tronco/citologia , Interferons/metabolismo , Histona Acetiltransferases/metabolismo , Histona Acetiltransferases/genética , Mucosa Intestinal/metabolismo , Mucosa Intestinal/citologia , Mitocôndrias/metabolismo , Autorrenovação Celular/genética , Intestinos/citologiaRESUMO
BACKGROUND: The function of hematopoietic stem cells (HSC) is regulated by HSC internal signaling pathways and their microenvironment. Chemokines and chemokine ligands play important roles in the regulation of HSC function. Yet, their functions in HSC are not fully understood. METHODS: We established Cxcr3 and Cxcl10 knockout mouse models (Cxcr3-/- and Cxcl10-/-) to analyze the roles of Cxcr3 or Cxcl10 in regulating HSC function. The cell cycle distribution of LT-HSC was assessed via flow cytometry. Cxcr3-/- and Cxcl10-/- stem/progenitor cells showed reduced self-renewal capacity as measured in serial transplantation assays. To study the effects of Cxcr3 or Cxcl10 deficient bone marrow microenvironment, we transplanted CD45.1 donor cells into Cxcr3-/-or Cxcl10-/- recipient mice (CD45.2) and examined donor-contributed hematopoiesis. RESULTS: Deficiency of Cxcl10 and its receptor Cxcr3 led to decreased BM cellularity in mice, with a significantly increased proportion of LT-HSC. Cxcl10-/- stem/progenitor cells showed reduced self-renewal capacity in the secondary transplantation assay. Notably, Cxcl10-/- donor-derived cells preferentially differentiated into B lymphocytes, with skewed myeloid differentiation ability. Meanwhile, Cxcr3-deficient HSCs demonstrated a reconstitution disadvantage in secondary transplantation, but the lineage bias was not significant. Interestingly, the absence of Cxcl10 or Cxcr3 in bone marrow microenvironment did not affect HSC function. CONCLUSIONS: The Cxcl10 and Cxcr3 regulate the function of HSC, including self-renewal and differentiation, adding to the understanding of the roles of chemokines in the regulation of HSC function.
Assuntos
Diferenciação Celular , Quimiocina CXCL10 , Células-Tronco Hematopoéticas , Receptores CXCR3 , Animais , Receptores CXCR3/metabolismo , Receptores CXCR3/genética , Quimiocina CXCL10/metabolismo , Quimiocina CXCL10/genética , Células-Tronco Hematopoéticas/metabolismo , Células-Tronco Hematopoéticas/citologia , Camundongos , Camundongos Knockout , Camundongos Endogâmicos C57BL , Autorrenovação Celular , Hematopoese , Transplante de Células-Tronco HematopoéticasRESUMO
The homeostasis of human pluripotent stem cells (hPSCs) requires the signaling balance of extracellular factors. Exogenous regulators from cell culture medium have been widely reported, but little attention has been paid to the autocrine factor from hPSCs themselves. In this report, we demonstrate that extracellular signal-related kinase 5 (ERK5) regulates endogenous autocrine factors essential for pluripotency and differentiation. ERK5 inhibition leads to erroneous cell fate specification in all lineages even under lineage-specific induction. hPSCs can self-renew under ERK5 inhibition in the presence of fibroblast growth factor 2 (FGF2) and transforming growth factor ß (TGF-ß), although NANOG expression is partially suppressed. Further analysis demonstrates that ERK5 promotes the expression of autocrine factors such as NODAL, FGF8, and WNT3. The addition of NODAL protein rescues NANOG expression and differentiation phenotypes under ERK5 inhibition. We demonstrate that constitutively active ERK5 pathway allows self-renewal even without essential growth factors FGF2 and TGF-ß. This study highlights the essential contribution of autocrine pathways to proper maintenance and differentiation.
Assuntos
Comunicação Autócrina , Proteína Quinase 7 Ativada por Mitógeno , Proteína Homeobox Nanog , Células-Tronco Pluripotentes , Humanos , Diferenciação Celular , Linhagem Celular , Linhagem da Célula , Proliferação de Células , Autorrenovação Celular , Fator 2 de Crescimento de Fibroblastos/metabolismo , Fator 2 de Crescimento de Fibroblastos/farmacologia , Proteína Quinase 7 Ativada por Mitógeno/metabolismo , Proteína Quinase 7 Ativada por Mitógeno/genética , Proteína Homeobox Nanog/metabolismo , Proteína Homeobox Nanog/genética , Proteína Nodal/metabolismo , Células-Tronco Pluripotentes/metabolismo , Células-Tronco Pluripotentes/citologia , Transdução de Sinais , Fator de Crescimento Transformador beta/metabolismoRESUMO
Mutation in nucleophosmin (NPM1) causes relocalization of this normally nucleolar protein to the cytoplasm (NPM1c+). Despite NPM1 mutation being the most common driver mutation in cytogenetically normal adult acute myeloid leukemia (AML), the mechanisms of NPM1c+-induced leukemogenesis remain unclear. Caspase-2 is a proapoptotic protein activated by NPM1 in the nucleolus. Here, we show that caspase-2 is also activated by NPM1c+ in the cytoplasm and DNA damage-induced apoptosis is caspase-2 dependent in NPM1c+ but not in NPM1wt AML cells. Strikingly, in NPM1c+ cells, caspase-2 loss results in profound cell cycle arrest, differentiation, and down-regulation of stem cell pathways that regulate pluripotency including impairment of the AKT/mTORC1 pathways, and inhibition of Rictor cleavage. In contrast, there were minimal differences in proliferation, differentiation, or the transcriptional profile of NPM1wt cells lacking caspase-2. Our results show that caspase-2 is essential for proliferation and self-renewal of AML cells expressing mutated NPM1. This study demonstrates that caspase-2 is a major effector of NPM1c+ function.
Assuntos
Apoptose , Caspase 2 , Proliferação de Células , Leucemia Mieloide Aguda , Mutação , Proteínas Nucleares , Nucleofosmina , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Leucemia Mieloide Aguda/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Nucleares/genética , Caspase 2/metabolismo , Caspase 2/genética , Humanos , Animais , Diferenciação Celular , Linhagem Celular Tumoral , Autorrenovação Celular/genética , Camundongos , Dano ao DNARESUMO
Whether small nucleolar RNAs (snoRNAs) are involved in the regulation of liver cancer stem cells (CSCs) self-renewal and serve as therapeutic targets remains largely unclear. Here we show that a functional snoRNA (SNORD88B) is robustly expressed in Hepatocellular carcinoma (HCC) tumors and liver CSCs. SNORD88B deficiency abolishes the self-renewal of liver CSCs and hepatocarcinogenesis. Mechanistically, SNORD88B anchors WRN in the nucleolus, promoting XRCC5 interacts with STK4 promoter to suppress its transcription, leading to inactivation of Hippo signaling. Moreover, low expression of STK4 and high expression of XRCC5 are positively correlated with HCC poor prognosis. Additionally, snord88b knockout suppresses mouse liver tumorigenesis. Notably, co-administration of SNORD88B antisense oligonucleotides (ASOs) with MST1 agonist adapalene (ADA) exert synergistic antitumor effects and increase overall murine survival. Our findings delineate that SNORD88B drives self-renewal of liver CSCs and accelerates HCC tumorigenesis via non-canonical mechanism, providing potential targets for liver cancer therapy by eliminating liver CSCs.
Assuntos
Carcinogênese , Carcinoma Hepatocelular , Neoplasias Hepáticas , Células-Tronco Neoplásicas , RNA Nucleolar Pequeno , Animais , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Humanos , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Camundongos , RNA Nucleolar Pequeno/metabolismo , RNA Nucleolar Pequeno/genética , Carcinogênese/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Helicase da Síndrome de Werner/metabolismo , Helicase da Síndrome de Werner/genética , Nucléolo Celular/metabolismo , Linhagem Celular Tumoral , Autorrenovação Celular , Regulação Neoplásica da Expressão Gênica , Masculino , Via de Sinalização Hippo , Oligonucleotídeos Antissenso/farmacologia , Transdução de SinaisRESUMO
Epidermal stem cells (EPSCs) are essential for maintaining skin homeostasis and ensuring a proper wound healing. During in vitro cultivations, EPSCs give rise to transient amplifying progenitors and differentiated cells, finally forming a stratified epithelium that can be grafted onto patients. Epithelial grafts have been used in clinics to cure burned patients or patients affected by genetic diseases. The long-term success of these advanced therapies relies on the presence of a correct amount of EPSCs that guarantees long-term epithelial regeneration. For this reason, a deeper understanding of self-renewal and differentiation is fundamental to fostering their clinical applications.The coordination between energetic metabolism (e.g., glycolysis, tricarboxylic acid cycle, oxidative phosphorylation, and amino acid synthesis pathways), molecular signalling pathways (e.g., p63, YAP, FOXM1, AMPK/mTOR), and epigenetic modifications controls fundamental biological processes as proliferation, self-renewal, and differentiation. This review explores how these signalling and metabolic pathways are interconnected in the epithelial cells, highlighting the distinct metabolic demands and regulatory mechanisms involved in skin physiology.
Assuntos
Diferenciação Celular , Metabolismo Energético , Transdução de Sinais , Humanos , Células-Tronco/metabolismo , Células-Tronco/citologia , Células Epiteliais/metabolismo , Animais , Autorrenovação CelularRESUMO
BACKGROUND: We have previously demonstrated the significant reliance of pancreatic Cancer Stem Cells (PaCSCs) on mitochondrial oxidative phosphorylation (OXPHOS), which enables versatile substrate utilization, including fatty acids (FAs). Notably, dysregulated lipid scavenging and aberrant FA metabolism are implicated in PDAC progression. METHODS & RESULTS: Our bioinformatics analyses revealed elevated expression of lipid metabolism-related genes in PDAC tissue samples compared to normal tissue samples, which correlated with a stemness signature. Additionally, PaCSCs exhibited heightened expression of diverse lipid metabolism genes and increased lipid droplet accumulation compared to differentiated progenies. Treatment with palmitic, oleic, and linolenic FAs notably augmented the self-renewal and chemotherapy resistance of CD133+ PaCSCs. Conversely, inhibitors of FA uptake, storage and metabolism reduced CSC populations both in vitro and in vivo. Mechanistically, inhibition of FA metabolism suppressed OXPHOS activity, inducing energy depletion and subsequent cell death in PaCSCs. Importantly, combining a FAO inhibitor and Gemcitabine treatment enhanced drug efficacy in vitro and in vivo, effectively diminishing the CSC content and functionality. CONCLUSION: Targeting FAO inhibition represents a promising therapeutic strategy against this highly tumorigenic population.
Assuntos
Carcinogênese , Resistencia a Medicamentos Antineoplásicos , Ácidos Graxos , Células-Tronco Neoplásicas , Oxirredução , Neoplasias Pancreáticas , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Humanos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Ácidos Graxos/metabolismo , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/tratamento farmacológico , Linhagem Celular Tumoral , Carcinogênese/patologia , Carcinogênese/efeitos dos fármacos , Animais , Fosforilação Oxidativa/efeitos dos fármacos , Autorrenovação Celular/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos , Antígeno AC133/metabolismo , Camundongos , Regulação Neoplásica da Expressão GênicaRESUMO
Acute myeloid leukemia is characterized by uncontrolled proliferation of self-renewing myeloid progenitors accompanied by a differentiation arrest. PHF6 is a chromatin-binding protein mutated in myeloid leukemias, and its isolated loss increases mouse HSC self-renewal without malignant transformation. We report here that Phf6 knockout increases the aggressiveness of Hoxa9-driven AML over serial transplantation, and increases the frequency of leukemia initiating cells. We define the in vivo hierarchy of Hoxa9-driven AML and identify a population that we term the "LIC-e" (leukemia initiating cells enriched) population. We find that Phf6 loss expands the LIC-e population and skews its transcriptome to a more stem-like state; concordant transcriptome shifts are also observed on PHF6 knockout in a human AML cell line and in PHF6 mutant patient samples from the BEAT AML dataset. We demonstrate that LIC-e accumulation in Phf6 knockout AML occurs not due to effects on cell cycle or apoptosis, but due to an increase in the fraction of its progeny that retain LIC-e identity. Our work indicates that Phf6 loss increases AML self-renewal through context-specific effects on leukemia stem cells.
Assuntos
Autorrenovação Celular , Leucemia Mieloide Aguda , Células-Tronco Neoplásicas , Proteínas Repressoras , Leucemia Mieloide Aguda/patologia , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Animais , Camundongos , Células-Tronco Neoplásicas/patologia , Células-Tronco Neoplásicas/metabolismo , Humanos , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Camundongos Knockout , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Proliferação de CélulasRESUMO
Haematopoietic stem cells (HSCs) possess unique physiological adaptations to sustain blood cell production and cope with stress responses throughout life. To maintain these adaptations, HSCs rely on maintaining a tightly controlled protein translation rate. However, the mechanism of how HSCs regulate protein translation remains to be fully elucidated. In this study, we investigate the role of transfer RNA (tRNA) m1A58 'writer' proteins TRMT6 and TRMT61A in regulating HSCs function. Trmt6 deletion promoted HSC proliferation through aberrant activation of mTORC1 signaling. TRMT6-deficient HSCs exhibited an impaired self-renewal ability in competitive transplantation assay. Mechanistically, single cell RNA-seq analysis reveals that the mTORC1 signaling pathway is highly upregulated in HSC-enriched cell populations after Trmt6 deletion. m1A-tRNA-seq and Western blot analysis suggest that TRMT6 promotes methylation modification of specific tRNA and expression of TSC1, fine-tuning mTORC1 signaling levels. Furthermore, Pharmacological inhibition of the mTORC1 pathway rescued functional defect in TRMT6-deficient HSCs. To our knowledge, this study is the first to elucidate a mechanism by which TRMT6-TRMT61A complex-mediated tRNA-m1A58 modification regulates HSC homeostasis.
Assuntos
Proliferação de Células , Células-Tronco Hematopoéticas , Alvo Mecanístico do Complexo 1 de Rapamicina , RNA de Transferência , Transdução de Sinais , Proteína 1 do Complexo Esclerose Tuberosa , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Animais , RNA de Transferência/metabolismo , RNA de Transferência/genética , Células-Tronco Hematopoéticas/metabolismo , Células-Tronco Hematopoéticas/citologia , Camundongos , Proteína 1 do Complexo Esclerose Tuberosa/metabolismo , Proteína 1 do Complexo Esclerose Tuberosa/genética , Autorrenovação Celular/genética , Camundongos Knockout , Metiltransferases/metabolismo , Metiltransferases/genética , Camundongos Endogâmicos C57BL , MetilaçãoRESUMO
Abnormal trophoblast self-renewal and differentiation during early gestation is the major cause of miscarriage, yet the underlying regulatory mechanisms remain elusive. Here, we show that trophoblast specific deletion of Kat8, a MYST family histone acetyltransferase, leads to extraembryonic ectoderm abnormalities and embryonic lethality. Employing RNA-seq and CUT&Tag analyses on trophoblast stem cells (TSCs), we further discover that KAT8 regulates the transcriptional activation of the trophoblast stemness marker, CDX2, via acetylating H4K16. Remarkably, CDX2 overexpression partially rescues the defects arising from Kat8 knockout. Moreover, increasing H4K16ac via using deacetylase SIRT1 inhibitor, EX527, restores CDX2 levels and promoted placental development. Clinical analysis shows reduced KAT8, CDX2 and H4K16ac expression are associated with recurrent pregnancy loss (RPL). Trophoblast organoids derived from these patients exhibit impaired TSC self-renewal and growth, which are significantly ameliorated with EX527 treatment. These findings suggest the therapeutic potential of targeting the KAT8-H4K16ac-CDX2 axis for mitigating RPL, shedding light on early gestational abnormalities.
Assuntos
Fator de Transcrição CDX2 , Proliferação de Células , Autorrenovação Celular , Histona Acetiltransferases , Trofoblastos , Trofoblastos/metabolismo , Fator de Transcrição CDX2/metabolismo , Fator de Transcrição CDX2/genética , Animais , Feminino , Humanos , Camundongos , Gravidez , Autorrenovação Celular/genética , Histona Acetiltransferases/metabolismo , Histona Acetiltransferases/genética , Aborto Habitual/metabolismo , Aborto Habitual/genética , Camundongos Knockout , Histonas/metabolismo , Diferenciação Celular , Placentação/genéticaRESUMO
Division and differentiation events by which cell populations with specific functions are generated often take place as part of a developmental programme, which can be represented by a sequence of compartments. A compartment is the set of cells with common characteristics; sharing, for instance, a spatial location or a phenotype. Differentiation events are transitions from one compartment to the next. Cells may also die or divide. We consider three different types of division events: (i) where both daughter cells inherit the mother's phenotype (self-renewal), (ii) where only one of the daughters changes phenotype (asymmetric division), and (iii) where both daughters change phenotype (symmetric division). The self-renewal probability in each compartment determines whether the progeny of a single cell, moving through the sequence of compartments, is finite or grows without bound. We analyse the progeny stochastic dynamics with probability generating functions. In the case of self-renewal, by following one of the daughters after any division event, we may construct lifelines containing only one cell at any time. We analyse the number of divisions along such lines, and the compartment where lines terminate with a death event. Analysis and numerical simulations are applied to a five-compartment model of the gradual differentiation of hematopoietic stem cells and to a model of thymocyte development: from pre-double positive to single positive (SP) cells with a bifurcation to either SP4 or SP8 in the last compartment of the sequence.
Assuntos
Diferenciação Celular , Divisão Celular , Processos Estocásticos , Autorrenovação Celular , Divisão Celular Assimétrica , Modelos Biológicos , Animais , Humanos , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/metabolismo , Células-Tronco Hematopoéticas/fisiologiaRESUMO
Esophageal epithelium is one of the most proliferative and regenerative epithelia in our body, indicating robust stem cell activity. However, the underlying mechanisms regulating the self-renewal and differentiation of esophageal stem cells need to be more elucidated. Here, we identify the role of YAP1 in esophageal stem cells. YAP1 is differentially expressed in the nuclei of esophageal basal cells. Furthermore, the treatment of verteporfin, a YAP1 inhibitor, interfered with esophageal organoid formation. Consistently, YAP1 deletion decreased esophageal organoid formation and the expression of basal genes while increasing the expression of suprabasal genes. Finally, global transcriptomic analysis revealed that YAP1 inhibition induced a significant enrichment of gene sets related to keratinization and cornification, while depleting gene sets related to DNA repair and chromosome maintenance. Our data uncover a novel regulatory mechanism for esophageal stem cells, which could provide a potential strategy for esophageal regenerative medicine.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Diferenciação Celular , Autorrenovação Celular , Esôfago , Células-Tronco , Proteínas de Sinalização YAP , Proteínas de Sinalização YAP/metabolismo , Células-Tronco/metabolismo , Células-Tronco/citologia , Esôfago/citologia , Esôfago/metabolismo , Animais , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Camundongos , Humanos , Organoides/metabolismo , Organoides/citologiaRESUMO
Benzene is a common environmental and occupational pollutant, benzene exposure causes damage to hematopoietic system. ZMAT3 is a zinc finger protein which has important biological functions. In this study, benzene-exposed mouse model and ZMAT3 overexpression and low expression hematopoietic stem cells (HSCs) models were constructed to explore the mechanism of ZMAT3 in benzene-induced hematopoietic toxicity. The results showed that benzene increased the expression of ZMAT3 in mouse bone marrow (BM) cells, HSCs and peripheral blood (PB) leukocyte, and the changes in HSCs were more sensitive than BM and PB cells. In addition, overexpression of ZMAT3 decreased the self-renewal ability of HSCs and reduced the HSCs differentiation into myeloid hematopoietic cells, while low expression has the opposite effect. Besides, over and low expression of ZMAT3 both increased the HSCs differentiation into lymphoid progenitor cells. Moreover, bioinformatics analysis suggested that ZMAT3 was associated with TNF-α signaling pathway, and the correlation was confirmed in mouse model. Meanwhile, the results indicated that ZMAT3 promoted TNF-α mRNA processing by binding to the ARE structural domain on TNF-α and interacting with hnRNP A2/B1 and hnRNP A1 proteins, ultimately activating the NF-κB signaling pathway. This study provides a new mechanism for the study of benzene toxicity.
Assuntos
Benzeno , Diferenciação Celular , Células-Tronco Hematopoéticas , NF-kappa B , Transdução de Sinais , Fator de Necrose Tumoral alfa , Animais , Células-Tronco Hematopoéticas/efeitos dos fármacos , Células-Tronco Hematopoéticas/metabolismo , Benzeno/toxicidade , NF-kappa B/metabolismo , NF-kappa B/genética , Diferenciação Celular/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo , Fator de Necrose Tumoral alfa/genética , Camundongos , Transdução de Sinais/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BL , Autorrenovação Celular/efeitos dos fármacosRESUMO
The processes that govern human haematopoietic stem cell (HSC) self-renewal and engraftment are poorly understood and challenging to recapitulate in culture to reliably expand functional HSCs1-3. Here we identify MYC target 1 (MYCT1; also known as MTLC) as a crucial human HSC regulator that moderates endocytosis and environmental sensing in HSCs. MYCT1 is selectively expressed in undifferentiated human haematopoietic stem and progenitor cells (HSPCs) and endothelial cells but becomes markedly downregulated during HSC culture. Lentivirus-mediated knockdown of MYCT1 prevented human fetal liver and cord blood (CB) HSPC expansion and engraftment. By contrast, restoring MYCT1 expression improved the expansion and engraftment of cultured CB HSPCs. Single-cell RNA sequencing of human CB HSPCs in which MYCT1 was knocked down or overexpressed revealed that MYCT1 governs important regulatory programmes and cellular properties essential for HSC stemness, such as ETS factor expression and low mitochondrial activity. MYCT1 is localized in the endosomal membrane in HSPCs and interacts with vesicle trafficking regulators and signalling machinery. MYCT1 loss in HSPCs led to excessive endocytosis and hyperactive signalling responses, whereas restoring MYCT1 expression balanced culture-induced endocytosis and dysregulated signalling. Moreover, sorting cultured CB HSPCs on the basis of lowest endocytosis rate identified HSPCs with preserved MYCT1 expression and MYCT1-regulated HSC stemness programmes. Our work identifies MYCT1-moderated endocytosis and environmental sensing as essential regulatory mechanisms required to preserve human HSC stemness. Our data also pinpoint silencing of MYCT1 as a cell-culture-induced vulnerability that compromises human HSC expansion.