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1.
Signal Transduct Target Ther ; 9(1): 181, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38992067

RESUMO

Mitotic catastrophe (MC), which occurs under dysregulated mitosis, represents a fascinating tactic to specifically eradicate tumor cells. Whether pyroptosis can be a death form of MC remains unknown. Proteasome-mediated protein degradation is crucial for M-phase. Bortezomib (BTZ), which inhibits the 20S catalytic particle of proteasome, is approved to treat multiple myeloma and mantle cell lymphoma, but not solid tumors due to primary resistance. To date, whether and how proteasome inhibitor affected the fates of cells in M-phase remains unexplored. Here, we show that BTZ treatment, or silencing of PSMC5, a subunit of 19S regulatory particle of proteasome, causes G2- and M-phase arrest, multi-polar spindle formation, and consequent caspase-3/GSDME-mediated pyroptosis in M-phase (designated as mitotic pyroptosis). Further investigations reveal that inhibitor of WEE1/PKMYT1 (PD0166285), but not inhibitor of ATR, CHK1 or CHK2, abrogates the BTZ-induced G2-phase arrest, thus exacerbates the BTZ-induced mitotic arrest and pyroptosis. Combined BTZ and PD0166285 treatment (named BP-Combo) selectively kills various types of solid tumor cells, and significantly lessens the IC50 of both BTZ and PD0166285 compared to BTZ or PD0166285 monotreatment. Studies using various mouse models show that BP-Combo has much stronger inhibition on tumor growth and metastasis than BTZ or PD0166285 monotreatment, and no obvious toxicity is observed in BP-Combo-treated mice. These findings disclose the effect of proteasome inhibitors in inducing pyroptosis in M-phase, characterize pyroptosis as a new death form of mitotic catastrophe, and identify dual inhibition of proteasome and WEE family kinases as a promising anti-cancer strategy to selectively kill solid tumor cells.


Assuntos
Bortezomib , Proteínas de Ciclo Celular , Mitose , Complexo de Endopeptidases do Proteassoma , Proteínas Tirosina Quinases , Piroptose , Piroptose/efeitos dos fármacos , Humanos , Camundongos , Animais , Proteínas Tirosina Quinases/genética , Proteínas Tirosina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/metabolismo , Mitose/efeitos dos fármacos , Mitose/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Complexo de Endopeptidases do Proteassoma/genética , Bortezomib/farmacologia , Linhagem Celular Tumoral , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/antagonistas & inibidores , Proteínas de Ciclo Celular/metabolismo , Inibidores de Proteassoma/farmacologia , Pirimidinas/farmacologia , Pirazóis/farmacologia , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/patologia , Ensaios Antitumorais Modelo de Xenoenxerto , Gasderminas , Pirimidinonas
2.
Nat Commun ; 15(1): 5611, 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38965240

RESUMO

Mitotic errors generate micronuclei entrapping mis-segregated chromosomes, which are susceptible to catastrophic fragmentation through chromothripsis. The reassembly of fragmented chromosomes by error-prone DNA double-strand break (DSB) repair generates diverse genomic rearrangements associated with human diseases. How specific repair pathways recognize and process these lesions remains poorly understood. Here we use CRISPR/Cas9 to systematically inactivate distinct DSB repair pathways and interrogate the rearrangement landscape of fragmented chromosomes. Deletion of canonical non-homologous end joining (NHEJ) components substantially reduces complex rearrangements and shifts the rearrangement landscape toward simple alterations without the characteristic patterns of chromothripsis. Following reincorporation into the nucleus, fragmented chromosomes localize within sub-nuclear micronuclei bodies (MN bodies) and undergo ligation by NHEJ within a single cell cycle. In the absence of NHEJ, chromosome fragments are rarely engaged by alternative end-joining or recombination-based mechanisms, resulting in delayed repair kinetics, persistent 53BP1-labeled MN bodies, and cell cycle arrest. Thus, we provide evidence supporting NHEJ as the exclusive DSB repair pathway generating complex rearrangements from mitotic errors.


Assuntos
Sistemas CRISPR-Cas , Cromotripsia , Quebras de DNA de Cadeia Dupla , Reparo do DNA por Junção de Extremidades , Mitose , Mitose/genética , Humanos , Rearranjo Gênico , Proteína 1 de Ligação à Proteína Supressora de Tumor p53/metabolismo , Proteína 1 de Ligação à Proteína Supressora de Tumor p53/genética , Micronúcleos com Defeito Cromossômico
3.
Genome Biol ; 25(1): 193, 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-39030605

RESUMO

BACKGROUND: The mitosis-to-meiosis switch during spermatogenesis requires dynamic changes in gene expression. However, the regulation of meiotic transcriptional and post-transcriptional machinery during this transition remains elusive. RESULTS: We report that methyltransferase-like protein 16 (METTL16), an N6-methyladenosine (m6A) writer, is required for mitosis-to-meiosis transition during spermatogenesis. Germline conditional knockout of Mettl16 in male mice impairs spermatogonial differentiation and meiosis initiation. Mechanistically, METTL16 interacts with splicing factors to regulate the alternative splicing of meiosis-related genes such as Stag3. Ribosome profiling reveals that the translation efficiency of many meiotic genes is dysregulated in METTL16-deficient testes. m6A-sequencing shows that ablation of METTL16 causes upregulation of the m6A-enriched transcripts and downregulation of the m6A-depleted transcripts, similar to Meioc and/or Ythdc2 mutants. Further in vivo and in vitro experiments demonstrate that the methyltransferase activity site (PP185-186AA) of METTL16 is necessary for spermatogenesis. CONCLUSIONS: Our findings support a molecular model wherein the m6A writer METTL16-mediated alternative splicing and translation efficiency regulation are required to control the mitosis-to-meiosis germ cell fate decision in mice, with implications for understanding meiosis-related male fertility disorders.


Assuntos
Adenosina , Processamento Alternativo , Meiose , Metiltransferases , Espermatogênese , Animais , Espermatogênese/genética , Masculino , Metiltransferases/metabolismo , Metiltransferases/genética , Camundongos , Adenosina/análogos & derivados , Adenosina/metabolismo , Biossíntese de Proteínas , Camundongos Knockout , Mitose , Testículo/metabolismo , Espermatogônias/metabolismo
4.
Nat Commun ; 15(1): 5794, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38987258

RESUMO

Plasmodium falciparum is the causative agent of malaria and remains a pathogen of global importance. Asexual blood stage replication, via a process called schizogony, is an important target for the development of new antimalarials. Here we use ultrastructure-expansion microscopy to probe the organisation of the chromosome-capturing kinetochores in relation to the mitotic spindle, the centriolar plaque, the centromeres and the apical organelles during schizont development. Conditional disruption of the kinetochore components, PfNDC80 and PfNuf2, is associated with aberrant mitotic spindle organisation, disruption of the centromere marker, CENH3 and impaired karyokinesis. Surprisingly, kinetochore disruption also leads to disengagement of the centrosome equivalent from the nuclear envelope. Severing the connection between the nucleus and the apical complex leads to the formation of merozoites lacking nuclei. Here, we show that correct assembly of the kinetochore/spindle complex plays a previously unrecognised role in positioning the nascent apical complex in developing P. falciparum merozoites.


Assuntos
Centrossomo , Cinetocoros , Plasmodium falciparum , Proteínas de Protozoários , Fuso Acromático , Cinetocoros/metabolismo , Plasmodium falciparum/metabolismo , Plasmodium falciparum/fisiologia , Centrossomo/metabolismo , Proteínas de Protozoários/metabolismo , Proteínas de Protozoários/genética , Fuso Acromático/metabolismo , Humanos , Merozoítos/metabolismo , Merozoítos/fisiologia , Mitose , Centrômero/metabolismo , Membrana Nuclear/metabolismo , Malária Falciparum/parasitologia , Malária Falciparum/metabolismo
5.
Int J Biol Sci ; 20(9): 3317-3333, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38993555

RESUMO

The glomerular podocyte, a terminally differentiated cell, is crucial for the integrity of the glomerular filtration barrier. The re-entry of podocytes into the mitotic phase results in injuries or death, known as mitotic catastrophe (MC), which significantly contributes to the progression of diabetic nephropathy (DN). Furthermore, P62-mediated autophagic flux has been shown to regulate DN-induced podocyte injury. Although previous studies, including ours, have demonstrated that ursolic acid (UA) mitigates podocyte injury by enhancing autophagy under high glucose conditions, the protective functions and potential regulatory mechanisms of UA against DN have not been fully elucidated. For aiming to investigate the regulatory mechanism of podocyte injuries in DN progression, and the protective function of UA treatment against DN progression, we utilized db/db mice and high glucose (HG)-induced podocyte models in vivo and in vitro, with or without UA administration. Our findings indicate that UA treatment reduced DN progression by improving biochemical indices. P62 accumulation led to Murine Double Minute gene 2 (MDM2)-regulated MC in podocytes during DN, which was ameliorated by UA through enhanced P62-mediated autophagy. Additionally, the overexpression of NF-κB p65 or TNF-α abolished the protective effects of UA both in vivo and in vitro. Overall, our results provide strong evidence that UA could be a potential therapeutic agent for DN, regulated by inhibiting podocyte MC through the NF-κB/MDM2/Notch1 pathway by targeting autophagic-P62 accumulation.


Assuntos
Autofagia , Nefropatias Diabéticas , Podócitos , Triterpenos , Ácido Ursólico , Podócitos/efeitos dos fármacos , Podócitos/metabolismo , Animais , Triterpenos/farmacologia , Triterpenos/uso terapêutico , Nefropatias Diabéticas/metabolismo , Nefropatias Diabéticas/tratamento farmacológico , Camundongos , Autofagia/efeitos dos fármacos , Mitose/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BL
6.
Theranostics ; 14(10): 3909-3926, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38994036

RESUMO

Background: Aurora kinase A (AURKA) is a potent oncogene that is often aberrantly expressed during tumorigenesis, and is associated with chemo-resistance in various malignancies. However, the role of AURKA in chemo-resistance remains largely elusive. Methods: The cleavage of AURKA upon viral infection or apoptosis stimuli was assesed by immunoblotting assays in several cancer cells or caspase deficient cell line models. The effect of AURKA cleavage at Asp132 on mitosis was explored by live cell imaging and immunofluorescence staining experiments. The role of Asp132-cleavage of AURKA induced by the chemotherapy drug paclitaxel was investigated using TUNEL, immunohistochemistry assay in mouse tumor xenograft model and patient tissues. Results: The proteolytic cleavage of AURKA at Asp132 commonly occurs in several cancer cell types, regardless of viral infection or apoptosis stimuli. Mechanistically, caspase 3/7/8 cleave AURKA at Asp132, and the Asp132-cleaved forms of AURKA promote cell apoptosis by disrupting centrosome formation and bipolar spindle assembly in metaphase during mitosis. The AURKAD132A mutation blocks the expression of cleaved caspase 3 and EGR1, which leads to reduced therapeutic effects of paclitaxel on colony formation and malignant growth of tumor cells in vitro and in vivo using a murine xenograft model and cancer patients. Conclusions: This study reveals that caspase-mediated AURKAD132 proteolysis is essential for paclitaxel to elicit cell apoptosis and indicates that AURKAD132 is a potential key target for chemotherapy.


Assuntos
Apoptose , Aurora Quinase A , Paclitaxel , Paclitaxel/farmacologia , Aurora Quinase A/metabolismo , Animais , Humanos , Apoptose/efeitos dos fármacos , Camundongos , Linhagem Celular Tumoral , Ensaios Antitumorais Modelo de Xenoenxerto , Caspases/metabolismo , Antineoplásicos Fitogênicos/farmacologia , Resistencia a Medicamentos Antineoplásicos , Mitose/efeitos dos fármacos , Proteólise/efeitos dos fármacos , Feminino , Camundongos Nus , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Neoplasias/patologia
7.
Mol Biol Rep ; 51(1): 792, 2024 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-39001981

RESUMO

BACKGROUND: The centromeres appear as primary constrictions on monocentric metaphase chromosomes; where sister chromatids are held together and assemble the proteinaceous kitechore complex at which microtubule proteins attach during nuclear divisions for pulling sister chromatids to opposite cell poles. The movement of chromosomes is usually governed by structural proteins that are either species-specific or highly conserved, such as the centromere-specific histone H3 (CENH3) and tubulin proteins, respectively. METHODS AND RESULTS: We aimed to detect these proteins across eight different Glycine species by an immunofluorescence assay using specific antibodies. Furthermore, with the α-tubulin antibody we traced the dynamics of microtubules during the mitotic cell cycle in Glycine max. With two-color immunofluorescence staining, we showed that both proteins interact during nuclear division. CONCLUSIONS: Finally, we proved that in different diploid and tetraploid Glycine species CENH3 can be detected in functional centromeres with spatial proximity of microtubule proteins.


Assuntos
Centrômero , Glicina , Histonas , Microtúbulos , Tubulina (Proteína) , Histonas/metabolismo , Tubulina (Proteína)/metabolismo , Centrômero/metabolismo , Glicina/metabolismo , Microtúbulos/metabolismo , Mitose , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Imunofluorescência/métodos
8.
Nat Commun ; 15(1): 5782, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38987269

RESUMO

Self-regenerating trigger waves can spread rapidly through the crowded cytoplasm without diminishing in amplitude or speed, providing consistent, reliable, long-range communication. The macromolecular concentration of the cytoplasm varies in response to physiological and environmental fluctuations, raising the question of how or if trigger waves can robustly operate in the face of such fluctuations. Using Xenopus extracts, we find that mitotic and apoptotic trigger wave speeds are remarkably invariant. We derive a model that accounts for this robustness and for the eventual slowing at extremely high and low cytoplasmic concentrations. The model implies that the positive and negative effects of cytoplasmic concentration (increased reactant concentration vs. increased viscosity) are nearly precisely balanced. Accordingly, artificially maintaining a constant cytoplasmic viscosity during dilution abrogates this robustness. The robustness in trigger wave speeds may contribute to the reliability of the extremely rapid embryonic cell cycle.


Assuntos
Citoplasma , Mitose , Xenopus laevis , Animais , Citoplasma/metabolismo , Apoptose , Viscosidade , Extratos Celulares/química , Modelos Biológicos , Xenopus , Ciclo Celular
9.
Proc Natl Acad Sci U S A ; 121(29): e2404551121, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-38990945

RESUMO

Confined cell migration hampers genome integrity and activates the ATR and ATM mechano-transduction pathways. We investigated whether the mechanical stress generated by metastatic interstitial migration contributes to the enhanced chromosomal instability observed in metastatic tumor cells. We employed live cell imaging, micro-fluidic approaches, and scRNA-seq to follow the fate of tumor cells experiencing confined migration. We found that, despite functional ATR, ATM, and spindle assembly checkpoint (SAC) pathways, tumor cells dividing across constriction frequently exhibited altered spindle pole organization, chromosome mis-segregations, micronuclei formation, chromosome fragility, high gene copy number variation, and transcriptional de-regulation and up-regulation of c-MYC oncogenic transcriptional signature via c-MYC locus amplifications. In vivo tumor settings showed that malignant cells populating metastatic foci or infiltrating the interstitial stroma gave rise to cells expressing high levels of c-MYC. Altogether, our data suggest that mechanical stress during metastatic migration contributes to override the checkpoint controls and boosts genotoxic and oncogenic events. Our findings may explain why cancer aneuploidy often does not correlate with mutations in SAC genes and why c-MYC amplification is strongly linked to metastatic tumors.


Assuntos
Movimento Celular , Amplificação de Genes , Proteínas Proto-Oncogênicas c-myc , Estresse Mecânico , Humanos , Movimento Celular/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Animais , Linhagem Celular Tumoral , Camundongos , Mitose/genética , Instabilidade Cromossômica , Regulação Neoplásica da Expressão Gênica , Neoplasias/genética , Neoplasias/patologia , Neoplasias/metabolismo
10.
Proc Natl Acad Sci U S A ; 121(29): e2321647121, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-38995965

RESUMO

Precise segregation of chromosomes during mitosis requires assembly of a bipolar mitotic spindle followed by correct attachment of microtubules to the kinetochores. This highly spatiotemporally organized process is controlled by various mitotic kinases and molecular motors. We have recently shown that Casein Kinase 1 (CK1) promotes timely progression through mitosis by phosphorylating FAM110A leading to its enrichment at spindle poles. However, the mechanism by which FAM110A exerts its function in mitosis is unknown. Using structure prediction and a set of deletion mutants, we mapped here the interaction of the N- and C-terminal domains of FAM110A with actin and tubulin, respectively. Next, we found that the FAM110A-Δ40-61 mutant deficient in actin binding failed to rescue defects in chromosomal alignment caused by depletion of endogenous FAM110A. Depletion of FAM110A impaired assembly of F-actin in the proximity of spindle poles and was rescued by expression of the wild-type FAM110A, but not the FAM110A-Δ40-61 mutant. Purified FAM110A promoted binding of F-actin to microtubules as well as bundling of actin filaments in vitro. Finally, we found that the inhibition of CK1 impaired spindle actin formation and delayed progression through mitosis. We propose that CK1 and FAM110A promote timely progression through mitosis by mediating the interaction between spindle microtubules and filamentous actin to ensure proper mitotic spindle formation.


Assuntos
Citoesqueleto de Actina , Microtúbulos , Mitose , Fuso Acromático , Microtúbulos/metabolismo , Fuso Acromático/metabolismo , Humanos , Citoesqueleto de Actina/metabolismo , Actinas/metabolismo , Células HeLa , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Caseína Quinase I/metabolismo , Caseína Quinase I/genética , Ligação Proteica
11.
Front Immunol ; 15: 1409448, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39015573

RESUMO

Background and aims: The mitotic catastrophe (MC) pathway plays an important role in hepatocellular carcinoma (HCC) progression and tumor microenvironment (TME) regulation. However, the mechanisms linking MC heterogeneity to immune evasion and treatment response remain unclear. Methods: Based on 94 previously published highly correlated genes for MC, HCC patients' data from the Cancer Genome Atlas (TCGA) and changes in immune signatures and prognostic stratification were studied. Time and spatial-specific differences for MCGs were assessed by single-cell RNA sequencing and spatial transcriptome (ST) analysis. Multiple external databases (GEO, ICGC) were employed to construct an MC-related riskscore model. Results: Identification of two MC-related subtypes in HCC patients from TCGA, with clear differences in immune signatures and prognostic risk stratification. Spatial mapping further associates low MC tumor regions with significant immune escape-related signaling. Nomogram combining MC riskscore and traditional indicators was validated great effect for early prediction of HCC patient outcomes. Conclusion: MC heterogeneity enables immune escape and therapy resistance in HCC. The MC gene signature serves as a reliable prognostic indicator for liver cancer. By revealing clear immune and spatial heterogeneity of HCC, our integrated approach provides contextual therapeutic strategies for optimal clinical decision-making.


Assuntos
Carcinoma Hepatocelular , Imunoterapia , Neoplasias Hepáticas , Mitose , Microambiente Tumoral , Humanos , Carcinoma Hepatocelular/terapia , Carcinoma Hepatocelular/imunologia , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/mortalidade , Neoplasias Hepáticas/terapia , Neoplasias Hepáticas/imunologia , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/diagnóstico , Prognóstico , Microambiente Tumoral/imunologia , Microambiente Tumoral/genética , Imunoterapia/métodos , Mitose/genética , Regulação Neoplásica da Expressão Gênica , Biomarcadores Tumorais/genética , Transcriptoma , Perfilação da Expressão Gênica , Nomogramas
12.
RNA Biol ; 21(1): 42-51, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38958280

RESUMO

The TATA-box binding protein (TBP) is the sole transcription factor common in the initiation complexes of the three major eukaryotic RNA Polymerases (Pol I, II and III). Although TBP is central to transcription by the three RNA Pols in various species, the emergence of TBP paralogs throughout evolution has expanded the complexity in transcription initiation. Furthermore, recent studies have emerged that questioned the centrality of TBP in mammalian cells, particularly in Pol II transcription, but the role of TBP and its paralogs in Pol I transcription remains to be re-evaluated. In this report, we show that in murine embryonic stem cells TBP localizes onto Pol I promoters, whereas the TBP paralog TRF2 only weakly associates to the Spacer Promoter of rDNA, suggesting that it may not be able to replace TBP for Pol I transcription. Importantly, acute TBP depletion does not fully disrupt Pol I occupancy or activity on ribosomal RNA genes, but TBP binding in mitosis leads to efficient Pol I reactivation following cell division. These findings provide a more nuanced role for TBP in Pol I transcription in murine embryonic stem cells.


Assuntos
Mitose , Regiões Promotoras Genéticas , RNA Polimerase I , Proteína de Ligação a TATA-Box , Transcrição Gênica , Animais , RNA Polimerase I/metabolismo , RNA Polimerase I/genética , Proteína de Ligação a TATA-Box/metabolismo , Proteína de Ligação a TATA-Box/genética , Camundongos , Células-Tronco Embrionárias Murinas/metabolismo , Células-Tronco Embrionárias Murinas/citologia , Ligação Proteica , DNA Ribossômico/genética , DNA Ribossômico/metabolismo
13.
Ren Fail ; 46(2): 2365408, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38874119

RESUMO

Podocyte loss in glomeruli is a fundamental event in the pathogenesis of chronic kidney diseases. Currently, mitotic catastrophe (MC) has emerged as the main cause of podocyte loss. However, the regulation of MC in podocytes has yet to be elucidated. The current work aimed to study the role and mechanism of p53 in regulating the MC of podocytes using adriamycin (ADR)-induced nephropathy. In vitro podocyte stimulation with ADR triggered the occurrence of MC, which was accompanied by hyperactivation of p53 and cyclin-dependent kinase (CDK1)/cyclin B1. The inhibition of p53 reversed ADR-evoked MC in podocytes and protected against podocyte injury and loss. Further investigation showed that p53 mediated the activation of CDK1/cyclin B1 by regulating the expression of Wee1. Restraining Wee1 abolished the regulatory effect of p53 inhibition on CDK1/cyclin B1 and rebooted MC in ADR-stimulated podocytes via p53 inhibition. In a mouse model of ADR nephropathy, the inhibition of p53 ameliorated proteinuria and podocyte injury. Moreover, the inhibition of p53 blocked the progression of MC in podocytes in ADR nephropathy mice through the regulation of the Wee1/CDK1/cyclin B1 axis. Our findings confirm that p53 contributes to MC in podocytes through regulation of the Wee1/CDK1/Cyclin B1 axis, which may represent a novel mechanism underlying podocyte injury and loss during the progression of chronic kidney disorder.


Assuntos
Proteína Quinase CDC2 , Proteínas de Ciclo Celular , Ciclina B1 , Doxorrubicina , Mitose , Podócitos , Proteínas Tirosina Quinases , Proteína Supressora de Tumor p53 , Podócitos/metabolismo , Podócitos/patologia , Animais , Proteína Quinase CDC2/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Camundongos , Proteínas Tirosina Quinases/metabolismo , Proteínas Tirosina Quinases/antagonistas & inibidores , Doxorrubicina/farmacologia , Ciclina B1/metabolismo , Proteínas de Ciclo Celular/metabolismo , Modelos Animais de Doenças , Humanos , Masculino
14.
Cell Struct Funct ; 49(2): 31-46, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38839376

RESUMO

In metazoans, the nuclear envelope (NE) disassembles during the prophase and reassembles around segregated chromatids during the telophase. The process of NE formation has been extensively studied using live-cell imaging. At the early step of NE reassembly in human cells, specific pattern-like localization of inner nuclear membrane (INM) proteins, connected to the nuclear pore complex (NPC), was observed in the so-called "core" region and "noncore" region on telophase chromosomes, which corresponded to the "pore-free" region and the "pore-rich" region, respectively, in the early G1 interphase nucleus. We refer to these phenomena as NE subdomain formation. To biochemically investigate this process, we aimed to develop an in vitro NE reconstitution system using digitonin-permeabilized semi-intact mitotic human cells coexpressing two INM proteins, emerin and lamin B receptor, which were labeled with fluorescent proteins. The targeting and accumulation of INM proteins to chromosomes before and after anaphase onset in semi-intact cells were observed using time-lapse imaging. Our in vitro NE reconstitution system recapitulated the formation of the NE subdomain, as in living cells, although chromosome segregation and cytokinesis were not observed. This in vitro NE reconstitution required the addition of a mitotic cytosolic fraction supplemented with a cyclin-dependent kinase inhibitor and energy sources. The cytoplasmic soluble factor(s) dependency of INM protein targeting differed among the segregation states of chromosomes. Furthermore, the NE reconstituted on segregated chromosomes exhibited active nucleocytoplasmic transport competency. These results indicate that the chromosome status changes after anaphase onset for recruiting NPC components.


Assuntos
Mitose , Membrana Nuclear , Proteínas Nucleares , Humanos , Membrana Nuclear/metabolismo , Proteínas Nucleares/metabolismo , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Células HeLa , Receptor de Lamina B , Receptores Citoplasmáticos e Nucleares/metabolismo , Receptores Citoplasmáticos e Nucleares/genética , Cromossomos Humanos/metabolismo , Poro Nuclear/metabolismo , Cromossomos/metabolismo
15.
Cell Rep ; 43(6): 114273, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38843397

RESUMO

Phosphoinositides (PtdIns) are a family of differentially phosphorylated lipid second messengers localized to the cytoplasmic leaflet of both plasma and intracellular membranes. Kinases and phosphatases can selectively modify the PtdIns composition of different cellular compartments, leading to the recruitment of specific binding proteins, which control cellular homeostasis and proliferation. Thus, while PtdIns affect cell growth and survival during interphase, they are also emerging as key drivers in multiple temporally defined membrane remodeling events of mitosis, like cell rounding, spindle orientation, cytokinesis, and abscission. In this review, we summarize and discuss what is known about PtdIns function during mitosis and how alterations in the production and removal of PtdIns can interfere with proper cell division.


Assuntos
Mitose , Fosfatidilinositóis , Humanos , Fosfatidilinositóis/metabolismo , Animais , Citocinese/fisiologia
16.
Cells ; 13(12)2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38920634

RESUMO

BACKGROUND: Identifying cells engaged in fundamental cellular processes, such as proliferation or living/death statuses, is pivotal across numerous research fields. However, prevailing methods relying on molecular biomarkers are constrained by high costs, limited specificity, protracted sample preparation, and reliance on fluorescence imaging. METHODS: Based on cellular morphology in phase contrast images, we developed a deep-learning model named Detector of Mitosis, Apoptosis, Interphase, Necrosis, and Senescence (D-MAINS). RESULTS: D-MAINS utilizes machine learning and image processing techniques, enabling swift and label-free categorization of cell death, division, and senescence at a single-cell resolution. Impressively, D-MAINS achieved an accuracy of 96.4 ± 0.5% and was validated with established molecular biomarkers. D-MAINS underwent rigorous testing under varied conditions not initially present in the training dataset. It demonstrated proficiency across diverse scenarios, encompassing additional cell lines, drug treatments, and distinct microscopes with different objective lenses and magnifications, affirming the robustness and adaptability of D-MAINS across multiple experimental setups. CONCLUSIONS: D-MAINS is an example showcasing the feasibility of a low-cost, rapid, and label-free methodology for distinguishing various cellular states. Its versatility makes it a promising tool applicable across a broad spectrum of biomedical research contexts, particularly in cell death and oncology studies.


Assuntos
Apoptose , Senescência Celular , Aprendizado Profundo , Interfase , Mitose , Necrose , Humanos , Linhagem Celular Tumoral , Neoplasias/patologia , Neoplasias/metabolismo , Processamento de Imagem Assistida por Computador/métodos
17.
Elife ; 132024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38904660

RESUMO

A functional nervous system is built upon the proper morphogenesis of neurons to establish the intricate connection between them. The microtubule cytoskeleton is known to play various essential roles in this morphogenetic process. While many microtubule-associated proteins (MAPs) have been demonstrated to participate in neuronal morphogenesis, the function of many more remains to be determined. This study focuses on a MAP called HMMR in mice, which was originally identified as a hyaluronan binding protein and later found to possess microtubule and centrosome binding capacity. HMMR exhibits high abundance on neuronal microtubules and altering the level of HMMR significantly affects the morphology of neurons. Instead of confining to the centrosome(s) like cells in mitosis, HMMR localizes to microtubules along axons and dendrites. Furthermore, transiently expressing HMMR enhances the stability of neuronal microtubules and increases the formation frequency of growing microtubules along the neurites. HMMR regulates the microtubule localization of a non-centrosomal microtubule nucleator TPX2 along the neurite, offering an explanation for how HMMR contributes to the promotion of growing microtubules. This study sheds light on how cells utilize proteins involved in mitosis for non-mitotic functions.


Assuntos
Proteínas Associadas aos Microtúbulos , Microtúbulos , Neurônios , Animais , Camundongos , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Associadas aos Microtúbulos/genética , Microtúbulos/metabolismo , Mitose , Neurônios/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Nucleares/genética
18.
Int J Mol Sci ; 25(12)2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38928036

RESUMO

Paclitaxel induces multipolar spindles at clinically relevant doses but does not substantially increase mitotic indices. Paclitaxel's anti-cancer effects are hypothesized to occur by promoting chromosome mis-segregation on multipolar spindles leading to apoptosis, necrosis and cyclic-GMP-AMP Synthase-Stimulator of Interferon Genes (cGAS-STING) pathway activation in daughter cells, leading to secretion of type I interferon (IFN) and immunogenic cell death. Eribulin and vinorelbine have also been reported to cause increases in multipolar spindles in cancer cells. Recently, suppression of Anaphase-Promoting Complex/Cyclosome-Cell Division Cycle 20 (APC/C-CDC20) activity using CRISPR/Cas9 mutagenesis has been reported to increase sensitivity to Kinesin Family 18a (KIF18a) inhibition, which functions to suppress multipolar mitotic spindles in cancer cells. We propose that a way to enhance the effectiveness of anti-cancer agents that increase multipolar spindles is by suppressing the APC/C-CDC20 to delay, but not block, anaphase entry. Delaying anaphase entry in genomically unstable cells may enhance multipolar spindle-induced cell death. In genomically stable healthy human cells, delayed anaphase entry may suppress the level of multipolar spindles induced by anti-cancer drugs and lower mitotic cytotoxicity. We outline specific combinations of molecules to investigate that may achieve the goal of enhancing the effectiveness of anti-cancer agents.


Assuntos
Ciclossomo-Complexo Promotor de Anáfase , Antineoplásicos , Fuso Acromático , Humanos , Ciclossomo-Complexo Promotor de Anáfase/metabolismo , Antineoplásicos/farmacologia , Fuso Acromático/efeitos dos fármacos , Fuso Acromático/metabolismo , Proteínas Cdc20/metabolismo , Proteínas Cdc20/genética , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Neoplasias/patologia , Mitose/efeitos dos fármacos
19.
Elife ; 132024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38864853

RESUMO

Cohesin is a multi-subunit protein that plays a pivotal role in holding sister chromatids together during cell division. Sister chromatid cohesion 3 (SCC3), constituents of cohesin complex, is highly conserved from yeast to mammals. Since the deletion of individual cohesin subunit always causes lethality, it is difficult to dissect its biological function in both mitosis and meiosis. Here, we obtained scc3 weak mutants using CRISPR-Cas9 system to explore its function during rice mitosis and meiosis. The scc3 weak mutants displayed obvious vegetative defects and complete sterility, underscoring the essential roles of SCC3 in both mitosis and meiosis. SCC3 is localized on chromatin from interphase to prometaphase in mitosis. However, in meiosis, SCC3 acts as an axial element during early prophase I and subsequently situates onto centromeric regions following the disassembly of the synaptonemal complex. The loading of SCC3 onto meiotic chromosomes depends on REC8. scc3 shows severe defects in homologous pairing and synapsis. Consequently, SCC3 functions as an axial element that is essential for maintaining homologous chromosome pairing and synapsis during meiosis.


Assuntos
Proteínas de Ciclo Celular , Proteínas Cromossômicas não Histona , Pareamento Cromossômico , Meiose , Oryza , Meiose/genética , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Oryza/genética , Proteínas Cromossômicas não Histona/metabolismo , Proteínas Cromossômicas não Histona/genética , Coesinas , Mitose , Complexo Sinaptonêmico/metabolismo , Complexo Sinaptonêmico/genética , Sistemas CRISPR-Cas
20.
Sci Rep ; 14(1): 14241, 2024 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-38902496

RESUMO

In recent years, there has been a surge in the development of methods for cell segmentation and tracking, with initiatives like the Cell Tracking Challenge driving progress in the field. Most studies focus on regular cell population videos in which cells are segmented and followed, and parental relationships annotated. However, DNA damage induced by genotoxic drugs or ionizing radiation produces additional abnormal events since it leads to behaviors like abnormal cell divisions (resulting in a number of daughters different from two) and cell death. With this in mind, we developed an automatic mitosis classifier to categorize small mitosis image sequences centered around one cell as "Normal" or "Abnormal." These mitosis sequences were extracted from videos of cell populations exposed to varying levels of radiation that affect the cell cycle's development. We explored several deep-learning architectures and found that a network with a ResNet50 backbone and including a Long Short-Term Memory (LSTM) layer produced the best results (mean F1-score: 0.93 ± 0.06). In the future, we plan to integrate this classifier with cell segmentation and tracking to build phylogenetic trees of the population after genomic stress.


Assuntos
Divisão Celular , Aprendizado Profundo , Mitose , Humanos , Processamento de Imagem Assistida por Computador/métodos , Rastreamento de Células/métodos
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