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1.
Sheng Wu Gong Cheng Xue Bao ; 36(10): 2092-2103, 2020 Oct 25.
Artigo em Chinês | MEDLINE | ID: mdl-33169574

RESUMO

Clostridium acetobutylicum is an important strain for bio-butanol formation. In recent years, gene-editing technology is widely used for developing the hyper-butanol-production strains. In this study, three genes (cac1251, cac2118 and cac2125) encoding cell division proteins (RodA, DivIVA and DivIB) in C. acetobutylicum were knocked out. The cac2118-knockout strain had changed its cell morphology to spherical-shape during the solventogenesis, and obtained a higher butanol yield of 0.19 g/g, increasing by 5.5%, compared with the wild type strain. The glucose utilization and butanol production of cac1251-knockout strain decreased by 33.9% and 56.3%, compared the with wild type strain, reaching to 47.3 g/L and 5.6 g/L. The cac1251-knockout strain and cac2125-knockout strain exhibited poor cell growth with cell optical density decreased by 40.4% and 38.3%, respectively, compared with that of the wild type strain. The results indicate that cell division protein DivIVA made the differences in the regulation of cell morphology and size. Cell division proteins RodA and DivIB played significant roles in the regulation of cell division, and affected cell growth, as well as solventogenesis metabolism.


Assuntos
Divisão Celular , Clostridium acetobutylicum , Butanóis , Divisão Celular/genética , Clostridium acetobutylicum/citologia , Clostridium acetobutylicum/genética , Fermentação , Técnicas de Inativação de Genes , Solventes
2.
Elife ; 92020 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-33044167

RESUMO

High levels of proteins called proteoglycans in the walls of umbilical arteries enable these arteries to close rapidly after birth and thus prevent blood loss in newborns.


Assuntos
Proteoglicanas , Artérias Umbilicais , Divisão Celular , Humanos , Recém-Nascido , Caracteres Sexuais
3.
Nat Commun ; 11(1): 4983, 2020 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-33020492

RESUMO

The energetic demands of a cell are believed to increase during mitosis, but the rates of ATP synthesis and consumption during mitosis have not been quantified. Here, we monitor mitochondrial membrane potential of single lymphocytic leukemia cells and demonstrate that mitochondria hyperpolarize from the G2/M transition until the metaphase-anaphase transition. This hyperpolarization was dependent on cyclin-dependent kinase 1 (CDK1) activity. By using an electrical circuit model of mitochondria, we quantify mitochondrial ATP synthesis rates in mitosis from the single-cell time-dynamics of mitochondrial membrane potential. We find that mitochondrial ATP synthesis decreases by approximately 50% during early mitosis and increases back to G2 levels during cytokinesis. Consistently, ATP levels and ATP synthesis are lower in mitosis than in G2 in synchronized cell populations. Overall, our results provide insights into mitotic bioenergetics and suggest that cell division is not a highly energy demanding process.


Assuntos
Trifosfato de Adenosina/biossíntese , Divisão Celular , Metabolismo Energético , Animais , Proteína Quinase CDC2/metabolismo , Linhagem Celular Tumoral , Citocinese , Camundongos , Mitocôndrias/metabolismo , Mitose , Modelos Biológicos
4.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 1432-1435, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018259

RESUMO

The progression of cells through the cell cycle is a tightly regulated process and is known to be key in maintaining normal tissue architecture and function. Disruption of these orchestrated phases will result in alterations that can lead to many diseases including cancer. Regrettably, reliable automatic tools to evaluate the cell cycle stage of individual cells are still lacking, in particular at interphase. Therefore, the development of new tools for a proper classification are urgently needed and will be of critical importance for cancer prognosis and predictive therapeutic purposes. Thus, in this work, we aimed to investigate three deep learning approaches for interphase cell cycle staging in microscopy images: 1) joint detection and cell cycle classification of nuclei patches; 2) detection of cell nuclei patches followed by classification of the cycle stage; 3) detection and segmentation of cell nuclei followed by classification of cell cycle staging. Our methods were applied to a dataset of microscopy images of nuclei stained with DAPI. The best results (0.908 F1-Score) were obtained with approach 3 in which the segmentation step allows for an intensity normalization that takes into account the intensities of all nuclei in a given image. These results show that for a correct cell cycle staging it is important to consider the relative intensities of the nuclei. Herein, we have developed a new deep learning method for interphase cell cycle staging at single cell level with potential implications in cancer prognosis and therapeutic strategies.


Assuntos
Núcleo Celular , Aprendizado Profundo , Ciclo Celular , Divisão Celular , Interfase
5.
Folia Biol (Praha) ; 66(3): 104-110, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33069189

RESUMO

Cancer development is a highly complicated process in which tumour growth depends on the development of its vascularization system. To support their own growth, tumour cells significantly modify their microenvironment. One of such modifications inflicted by tumours is stimulation of endothelial cell migration and proliferation. There is accumulating evidence that extracellular vesicles (EVs) secreted by tumour cells (tumour-derived EVs, TEVs) may be regarded as "messengers" with the potential for affecting the biological activities of target cells. Interaction of TEVs with different cell types occurs in an auto- and paracrine manner and may lead to changes in the function of the latter, e.g., promoting motility, proliferation, etc. This study analysed the proangiogenic activity of EVs derived from human pancreatic adenocarcinoma cell line (HPC-4, TEVHPC) in vitro and their effect in vivo on Matrigel matrix vascularization in severe combined immunodeficient (SCID) mice. TEVHPC enhanced proliferation of HPC-4 cells and induced their motility. Moreover, TEVHPC stimulated human umbilical vein endothelial cell (HUVEC) proliferation and migration in vitro. Additionally, TEVHPC influenced secretion of proangiogenic factors (IL-8, VEGF) by HUVEC cells and supported Matrigel matrix haemoglobinization in vivo. These data show that TEVs may support tumour propagation in an autocrine manner and may support vascularization of the tumour. The presented data are in line with the theory that tumour cells themselves are able to modulate the microenvironment via TEVs to maximize their growth potential.


Assuntos
Carcinoma Ductal Pancreático/patologia , Vesículas Extracelulares/patologia , Neoplasias Pancreáticas/patologia , Animais , Comunicação Autócrina , Divisão Celular , Linhagem Celular Tumoral , Quimiotaxia , Colágeno , Combinação de Medicamentos , Células Endoteliais da Veia Umbilical Humana , Humanos , Interleucina-8/genética , Interleucina-8/metabolismo , Laminina , Camundongos , Camundongos SCID , Transplante de Neoplasias , Neovascularização Patológica/etiologia , Proteoglicanas , RNA Mensageiro/biossíntese , Microambiente Tumoral , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
6.
Folia Biol (Praha) ; 66(3): 111-115, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33069190

RESUMO

Progenitor cells of the human erythroid and granulocytic cell lineages are characterized by the presence of several nucleoli. One of these nucleoli is larger and possesses more fibrillar centres than others. Such nucleolus is apparently dominant in respect of both size and main nucleolar function such as nucleolar-ribosomal RNA transcription. Such nucleolus is also visible in specimens using conventional visualization procedures, in contrast to smaller nucleoli. In the terminal differentiation nucleated stages of the erythroid and granulocytic development, dominant nucleoli apparently disappeared, since these cells mostly contained very small nucleoli of a similar size with one fibrillar centre. Thus, the easily visible dominant nucleoli appear to be useful markers of the progenitor cell state, such as proliferation, and differentiation potential.


Assuntos
Nucléolo Celular/fisiologia , Células Precursoras Eritroides/ultraestrutura , Células Precursoras de Granulócitos/ultraestrutura , Diferenciação Celular , Divisão Celular , Linhagem da Célula , Nucléolo Celular/ultraestrutura , Núcleo Celular/ultraestrutura , Granulócitos/ultraestrutura , Humanos , RNA Ribossômico/metabolismo
7.
Wei Sheng Yan Jiu ; 49(5): 780-784, 2020 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-33070824

RESUMO

OBJECTIVE: Investigate the estrogen receptor expression in human thyroid squamous cell carcinoma SW579 and the effects of genistein on the apoptosis and cycle of SW579 and its mechnism. METHODS: The real-time PCR was applied to detect the expression of estrogen receptor(ER)α、ERß and G protein-coupled receptor(GPR)30 in human thyroid squamous cell line SW579; MTT was used to test the effect of genistein on cell proliferation in the SW579 cells before and after blocking GPR30; flow cytometry was explorited to measure the effect of genistein on the cell cycle and apoptosis in the SW579 was detected before and after blocking GPR30. RESULTS: The high concentration of genistein promoted the expression of ERß and GPR30 in the SW579 cells, but ERα was not expressed. The specific blocking of GPR30, the cell proliferation was aboviously inhibited by genistein in the SW579 cells and the cell apoptosis was markedly promoted after the GPR30 was blocked; The cell cycle was mainly blocked in G_2/M phase. CONCLUSION: Genistein can obiviously promote the cell proliferation in the SW579 cells, which may be related to the action of GPR30.


Assuntos
Genisteína , Neoplasias da Glândula Tireoide , Apoptose , Ciclo Celular , Divisão Celular , Linhagem Celular Tumoral , Células Epiteliais , Genisteína/farmacologia , Humanos
8.
PLoS Genet ; 16(9): e1009011, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32986715

RESUMO

Neuronal precursor cells undergo self-renewing and non-self-renewing asymmetric divisions to generate a large number of neurons of distinct identities. In Drosophila, primary precursor neuroblasts undergo a varying number of self-renewing asymmetric divisions, with one known exception, the MP2 lineage, which undergoes just one terminal asymmetric division similar to the secondary precursor cells. The mechanism and the genes that regulate the transition from self-renewing to non-self-renewing asymmetric division or the number of times a precursor divides is unknown. Here, we show that the T-box transcription factor, Midline (Mid), couples these events. We find that in mid loss of function mutants, MP2 undergoes additional self-renewing asymmetric divisions, the identity of progeny neurons generated dependent upon Numb localization in the parent MP2. MP2 expresses Mid transiently and an over-expression of mid in MP2 can block its division. The mechanism which directs the self-renewing asymmetric division of MP2 in mid involves an upregulation of Cyclin E. Our results indicate that Mid inhibits cyclin E gene expression by binding to a variant Mid-binding site in the cyclin E promoter and represses its expression without entirely abolishing it. Consistent with this, over-expression of cyclin E in MP2 causes its multiple self-renewing asymmetric division. These results reveal a Mid-regulated pathway that restricts the self-renewing asymmetric division potential of cells via inhibiting cyclin E and facilitating their exit from cell cycle.


Assuntos
Divisão Celular/genética , Sistema Nervoso Central/metabolismo , Proteínas de Drosophila/metabolismo , Proteínas com Domínio T/metabolismo , Animais , Ciclo Celular , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Feminino , Hormônios Juvenis/genética , Hormônios Juvenis/metabolismo , Masculino , Proteínas do Tecido Nervoso/genética , Células-Tronco Neurais/metabolismo , Neurônios/metabolismo , Proteínas com Domínio T/genética , Fatores de Transcrição/genética
9.
Nat Commun ; 11(1): 4782, 2020 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-32963223

RESUMO

Polycomb and Trithorax group proteins maintain stable epigenetic memory of gene expression states for some genes, but many targets show highly dynamic regulation. Here we combine experiment and theory to examine the mechanistic basis of these different modes of regulation. We present a mathematical model comprising a Polycomb/Trithorax response element (PRE/TRE) coupled to a promoter and including Drosophila developmental timing. The model accurately recapitulates published studies of PRE/TRE mediated epigenetic memory of both silencing and activation. With minimal parameter changes, the same model can also recapitulate experimental data for a different PRE/TRE that allows dynamic regulation of its target gene. The model predicts that both cell cycle length and PRE/TRE identity are critical for determining whether the system gives stable memory or dynamic regulation. Our work provides a simple unifying framework for a rich repertoire of PRE/TRE functions, and thus provides insights into  genome-wide Polycomb/Trithorax regulation.


Assuntos
Proteínas Cromossômicas não Histona/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Epigenômica , Regulação da Expressão Gênica no Desenvolvimento/genética , Modelos Teóricos , Complexo Repressor Polycomb 1/genética , Animais , Divisão Celular , Proteínas Cromossômicas não Histona/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/fisiologia , Epigênese Genética , Feminino , Inativação Gênica , Complexo Repressor Polycomb 1/metabolismo , Proteínas do Grupo Polycomb/metabolismo , Regiões Promotoras Genéticas , Elementos de Resposta
10.
PLoS Biol ; 18(9): e3000852, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32931487

RESUMO

Olfaction in most animals is mediated by neurons bearing cilia that are accessible to the environment. Olfactory sensory neurons (OSNs) in chordates usually have multiple cilia, each with a centriole at its base. OSNs differentiate from stem cells in the olfactory epithelium, and how the epithelium generates cells with many centrioles is not yet understood. We show that centrioles are amplified via centriole rosette formation in both embryonic development and turnover of the olfactory epithelium in adult mice, and rosette-bearing cells often have free centrioles in addition. Cells with amplified centrioles can go on to divide, with centrioles clustered at each pole. Additionally, we found that centrioles are amplified in immediate neuronal precursors (INPs) concomitant with elevation of mRNA for polo-like kinase 4 (Plk4) and SCL/Tal1-interrupting locus gene (Stil), key regulators of centriole duplication. These results support a model in which centriole amplification occurs during a transient state characterized by elevated Plk4 and Stil in early INP cells. These cells then go on to divide at least once to become OSNs, demonstrating that cell division with amplified centrioles, known to be tolerated in disease states, can occur as part of a normal developmental program.


Assuntos
Divisão Celular/fisiologia , Centríolos/fisiologia , Células-Tronco Neurais/citologia , Células-Tronco Neurais/fisiologia , Neurônios Receptores Olfatórios/fisiologia , Envelhecimento/fisiologia , Animais , Ciclo Celular/fisiologia , Células Cultivadas , Embrião de Mamíferos , Desenvolvimento Embrionário/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Córtex Olfatório/citologia , Córtex Olfatório/embriologia , Mucosa Olfatória/citologia , Mucosa Olfatória/embriologia , Mucosa Olfatória/ultraestrutura , Neurônios Receptores Olfatórios/citologia , Neurônios Receptores Olfatórios/ultraestrutura
11.
Anticancer Res ; 40(10): 5517-5527, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32988875

RESUMO

BACKGROUND/AIM: Drug resistance is a significant cause of high mortality in ovarian cancer (OC) patients. The reverse transcriptase inhibitor azidothymidine (AZT) has been utilized as a treatment for tumors, but its role in OC treatment has not been revealed. The aim of the present in vitro study was to examine the influence of AZT on the growth of human OC cells and the involved proteins. MATERIALS AND METHODS: The proliferation, cell cycle distribution, extent of apoptosis, mitotic index, and terminal restriction fragment length were examined in three OC cell lines, CaOV3, TOV112D, and TOV21G, treated with AZT. RESULTS: AZT inhibited growth of the TOV21G and CaOV3 cell lines by regulating cell cycle distribution. Specifically, AZT caused G2/M phase arrest on TOV21G cells and S phase arrest on CaOV3 cells. In addition, AZT treatment induced up-regulation of p21 and p16 in the TOV21G and CaOV3 cell line, respectively. CONCLUSION: AZT inhibited cell proliferation in serous and clear cell OC via the regulation of cell cycle distribution.


Assuntos
Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Neoplasias Ovarianas/tratamento farmacológico , Zidovudina/farmacologia , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Feminino , Humanos , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia
12.
Adv Exp Med Biol ; 1267: 59-80, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32894477

RESUMO

The internal spatial organization of prokaryotic organisms, including Escherichia coli, is essential for the proper functioning of processes such as cell division. One source of this organization in E. coli is the nucleoid, which causes the exclusion of macromolecules - e.g. protein aggregates and the chemotaxis network - from midcell. Similarly, following DNA replication, the nucleoid(s) assist in placing the Z-ring at midcell. These processes need to be efficient in optimal conditions and robust to suboptimal conditions. After reviewing recent findings on these topics, we make use of past data to study the efficiency of the spatial constraining of Z-rings, chemotaxis networks, and protein aggregates, as a function of the nucleoid(s) morphology. Also, we compare the robustness of these processes to nonoptimal temperatures. We show that Z-rings, Tsr clusters, and protein aggregates have temperature-dependent spatial distributions along the major cell axis that are consistent with the nucleoid(s) morphology and the volume-exclusion phenomenon. Surprisingly, the consequences of the changes in nucleoid size with temperature are most visible in the kurtosis of these spatial distributions, in that it has a statistically significant linear correlation with the mean nucleoid length and, in the case of Z-rings, with the distance between nucleoids prior to cell division. Interestingly, we also find a negative, statistically significant linear correlation between the efficiency of these processes at the optimal condition and their robustness to suboptimal conditions, suggesting a trade-off between these traits.


Assuntos
Escherichia coli/citologia , Escherichia coli/metabolismo , Organelas/metabolismo , Divisão Celular , Replicação do DNA
13.
Nucleic Acids Res ; 48(19): 10802-10819, 2020 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-32997144

RESUMO

In bacteria, rapid adaptation to changing environmental conditions depends on the interplay between housekeeping and alternative σ factors, responsible for transcription of specific regulons by RNA polymerase (RNAP). In comparison with alternative σ factors, primary σs contain poorly conserved region 1.1, whose functions in transcription are only partially understood. We found that a single mutation in region 1.1 in Escherichia coli σ70 rewires transcription regulation during cell growth resulting in profound phenotypic changes. Despite its destabilizing effect on promoter complexes, this mutation increases the activity of rRNA promoters and also decreases RNAP sensitivity to the major regulator of stringent response DksA. Using total RNA sequencing combined with single-cell analysis of gene expression we showed that changes in region 1.1 disrupt the balance between the "greed" and "fear" strategies thus making the cells more susceptible to environmental threats and antibiotics. Our results reveal an unexpected role of σ region 1.1 in growth-dependent transcription regulation and suggest that changes in this region may facilitate rapid switching of RNAP properties in evolving bacterial populations.


Assuntos
Divisão Celular , Regulação Bacteriana da Expressão Gênica , Fator sigma/genética , Escherichia coli , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Mutação Puntual , Domínios Proteicos , Fator sigma/química , Fator sigma/metabolismo , Transcrição Genética
14.
Nature ; 585(7825): 404-409, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32848249

RESUMO

To implant in the uterus, the mammalian embryo first specifies two cell lineages: the pluripotent inner cell mass that forms the fetus, and the outer trophectoderm layer that forms the placenta1. In many organisms, asymmetrically inherited fate determinants drive lineage specification2, but this is not thought to be the case during early mammalian development. Here we show that intermediate filaments assembled by keratins function as asymmetrically inherited fate determinants in the mammalian embryo. Unlike F-actin or microtubules, keratins are the first major components of the cytoskeleton that display prominent cell-to-cell variability, triggered by heterogeneities in the BAF chromatin-remodelling complex. Live-embryo imaging shows that keratins become asymmetrically inherited by outer daughter cells during cell division, where they stabilize the cortex to promote apical polarization and YAP-dependent expression of CDX2, thereby specifying the first trophectoderm cells of the embryo. Together, our data reveal a mechanism by which cell-to-cell heterogeneities that appear before the segregation of the trophectoderm and the inner cell mass influence lineage fate, via differential keratin regulation, and identify an early function for intermediate filaments in development.


Assuntos
Linhagem da Célula , Embrião de Mamíferos/citologia , Embrião de Mamíferos/metabolismo , Queratinas/metabolismo , Actinas/metabolismo , Animais , Divisão Celular , Montagem e Desmontagem da Cromatina , Proteínas Cromossômicas não Histona/metabolismo , Ectoderma/citologia , Embrião de Mamíferos/embriologia , Feminino , Humanos , Filamentos Intermediários/metabolismo , Camundongos , Microtúbulos/metabolismo , Complexos Multiproteicos/metabolismo , Trofoblastos/citologia
15.
J Biosci Bioeng ; 130(5): 525-532, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32800439

RESUMO

Chinese hamster ovary (CHO) cells are used as host cells for biopharmaceutical production, including monoclonal antibodies (mAbs). Arresting the cell cycle with chemical compounds is an effective approach to improve biopharmaceutical productivity. In a previous study, potential new cell cycle-arresting compounds were screened from marine-derived microorganism culture extracts, and it was suggested that staurosporine might improve mAb productivity in CHO cells via cell cycle arrest. The purpose of this study was to demonstrate the effectiveness of staurosporine as a cell-cycle arresting compound to improve mAb productivity. The optimal staurosporine concentration range was initially investigated using batch cultures. Thereafter, the effects on the culture profile and mAb productivity were evaluated using fed-batch cultures. Staurosporine at concentrations ≥10 nM induced cell death, but at concentrations ≤5 nM did not. In the range of 2-4 nM, cell growth was inhibited, whereas the specific production rate (Qp) and cell longevity were improved in a dose-dependent manner. The Qp and maximum mAb concentration with 4 nM staurosporine improved by 36.3 and 5.2%, respectively, compared to those with control conditions. Cell viability post-culture without staurosporine was 40.0 ± 0.3%, whereas with 4 nM staurosporine, it was 90.1 ± 1.0%. Flow cytometric analysis indicated cell-cycle arrest at the G1/G0 phase with 4 nM staurosporine addition. The present study highlighted the efficacy of staurosporine in improving mAb production by causing cell-cycle arrest. Further research into staurosporine analogs and how to use them will lead to development of more effective industrial production technologies of biopharmaceuticals.


Assuntos
Anticorpos Monoclonais/biossíntese , Proteínas Recombinantes/biossíntese , Estaurosporina/farmacologia , Animais , Técnicas de Cultura Celular por Lotes , Células CHO , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cricetinae , Cricetulus , Relação Dose-Resposta a Droga , Proteínas Recombinantes/genética
16.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 28(4): 1357-1362, 2020 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-32798426

RESUMO

OBJECTIVE: To explore the method for inducing the differentiation of bone marrow cells into megakaryocytes in vitro so as to use for evaluating the activity of traditional Chinese medicines. METHODS: The bone marrow cells were separated from femurs and tibias of mice. The experiments were divided into 4 groups: control (no adding cytokines), TPO (adding 50 ng/ml TPO), TPO+SCF (50 ng/ml+50 ng/ml) and TPO+SCF+IL-6+IL-9 (50 ng/ml+50 ng/ml+20 ng/ml+20 ng/ml). The bone marrow cells in 4 groups were cultured in vitro for 6 d. Then the cell growth status was observed by the inverted microscopy, and the cell count was detected by using the automatic cell counter. The ratio and absolute count of megakaryocytes were detected by flow cytometry. RESULTS: Compared with control, three induction methods could stimulate the differentiation of bone marrow cells into megakaryocytes in vitro. TPO could slightly enhance the differentiation of bone marrow cells into megakaryocytes. Both the combination of TPO and SCF, and the combination of TPO, SCF, IL-6 and IL-9 could intensively stimulate proliferation of bone morrow cells and promote the differentiation of bone marrow cells into megakaryocytes. The addition of IL-6 and IL-9 could decrease the proliferation of non-megakaryocytes, but promote the differentiation of bone marrow cells into megakaryocytes. CONCLUSION: The optimized differentiation of bone marrow cells into megakaryocytes has been completed by co-induction regimen of TPO, SCF, IL-6 and IL-9, which can be used to screen and evaluate traditional Chinese medicines promoting formation of platelets.


Assuntos
Interleucina-3 , Megacariócitos , Animais , Células da Medula Óssea , Contagem de Células , Diferenciação Celular , Divisão Celular , Células Cultivadas , Camundongos , Fator de Células-Tronco , Trombopoetina
17.
Nat Commun ; 11(1): 3839, 2020 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-32737294

RESUMO

Chromatin regulates spatiotemporal gene expression during neurodevelopment, but it also mediates DNA damage repair essential to proliferating neural progenitor cells (NPCs). Here, we uncover molecularly dissociable roles for nucleosome remodeler Ino80 in chromatin-mediated transcriptional regulation and genome maintenance in corticogenesis. We find that conditional Ino80 deletion from cortical NPCs impairs DNA double-strand break (DSB) repair, triggering p53-dependent apoptosis and microcephaly. Using an in vivo DSB repair pathway assay, we find that Ino80 is selectively required for homologous recombination (HR) DNA repair, which is mechanistically distinct from Ino80 function in YY1-associated transcription. Unexpectedly, sensitivity to loss of Ino80-mediated HR is dependent on NPC division mode: Ino80 deletion leads to unrepaired DNA breaks and apoptosis in symmetric NPC-NPC divisions, but not in asymmetric neurogenic divisions. This division mode dependence is phenocopied following conditional deletion of HR gene Brca2. Thus, distinct modes of NPC division have divergent requirements for Ino80-dependent HR DNA repair.


Assuntos
ATPases Associadas a Diversas Atividades Celulares/genética , Proteína BRCA2/genética , Cromatina/química , Proteínas de Ligação a DNA/genética , Células-Tronco Neurais/metabolismo , Neurogênese/genética , Reparo de DNA por Recombinação , ATPases Associadas a Diversas Atividades Celulares/deficiência , Animais , Apoptose/genética , Proteína BRCA2/deficiência , Divisão Celular , Cromatina/metabolismo , Montagem e Desmontagem da Cromatina , DNA/genética , DNA/metabolismo , Quebras de DNA de Cadeia Dupla , Proteínas de Ligação a DNA/deficiência , Embrião de Mamíferos , Regulação da Expressão Gênica no Desenvolvimento , Camundongos , Camundongos Transgênicos , Neocórtex/citologia , Neocórtex/crescimento & desenvolvimento , Neocórtex/metabolismo , Células-Tronco Neurais/citologia , Transdução de Sinais , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Fator de Transcrição YY1/genética , Fator de Transcrição YY1/metabolismo
18.
Nat Commun ; 11(1): 3796, 2020 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-32732900

RESUMO

The ter region of the bacterial chromosome, where replication terminates, is the last to be segregated before cell division in Escherichia coli. Delayed segregation is controlled by the MatP protein, which binds to specific sites (matS) within ter, and interacts with other proteins such as ZapB. Here, we investigate the role of MatP by combining short-time mobility analyses of the ter locus with biochemical approaches. We find that ter mobility is similar to that of a non ter locus, except when sister ter loci are paired after replication. This effect depends on MatP, the persistence of catenanes, and ZapB. We characterise MatP/DNA complexes and conclude that MatP binds DNA as a tetramer, but bridging matS sites in a DNA-rich environment remains infrequent. We propose that tetramerisation of MatP links matS sites with ZapB and/or with non-specific DNA to promote optimal pairing of sister ter regions until cell division.


Assuntos
Proteínas de Ciclo Celular/genética , Proteínas Cromossômicas não Histona/genética , Cromossomos Bacterianos/genética , Proteínas de Escherichia coli/genética , Escherichia coli/genética , Divisão Celular/genética , Proteínas Cromossômicas não Histona/metabolismo , Replicação do DNA/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo
19.
Nat Commun ; 11(1): 4149, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32811832

RESUMO

Many bacteria can form wall-deficient variants, or L-forms, that divide by a simple mechanism that does not require the FtsZ-based cell division machinery. Here, we use microfluidic systems to probe the growth, chromosome cycle and division mechanism of Bacillus subtilis L-forms. We find that forcing cells into a narrow linear configuration greatly improves the efficiency of cell growth and chromosome segregation. This reinforces the view that L-form division is driven by an excess accumulation of surface area over volume. Cell geometry also plays a dominant role in controlling the relative positions and movement of segregating chromosomes. Furthermore, the presence of the nucleoid appears to influence division both via a cell volume effect and by nucleoid occlusion, even in the absence of FtsZ. Our results emphasise the importance of geometric effects for a range of crucial cell functions, and are of relevance for efforts to develop artificial or minimal cell systems.


Assuntos
Bacillus subtilis/crescimento & desenvolvimento , Divisão Celular/fisiologia , Segregação de Cromossomos/fisiologia , Formas L/crescimento & desenvolvimento , Dispositivos Lab-On-A-Chip/microbiologia , Bacillus subtilis/citologia , Bacillus subtilis/fisiologia , Parede Celular/fisiologia , Cromossomos Bacterianos/metabolismo , Cromossomos Bacterianos/fisiologia , Formas L/citologia , Formas L/fisiologia , Modelos Biológicos
20.
PLoS Genet ; 16(8): e1008989, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32810129

RESUMO

Drosophila Myc (dMyc), as a broad-spectrum transcription factor, can regulate the expression of a large number of genes to control diverse cellular processes, such as cell cycle progression, cell growth, proliferation and apoptosis. However, it remains largely unknown about whether dMyc can be involved in Drosophila innate immune response. Here, we have identified dMyc to be a negative regulator of Drosophila Imd pathway via the loss- and gain-of-function screening. We demonstrate that dMyc inhibits Drosophila Imd immune response via directly activating miR-277 transcription, which further inhibit the expression of imd and Tab2-Ra/b. Importantly, dMyc can improve the survival of flies upon infection, suggesting inhibiting Drosophila Imd pathway by dMyc is vital to restore immune homeostasis that is essential for survival. Taken together, our study not only reports a new dMyc-miR-277-imd/Tab2 axis involved in the negative regulation of Drosophila Imd pathway, and provides a new insight into the complex regulatory mechanism of Drosophila innate immune homeostasis maintenance.


Assuntos
Proteínas de Ligação a DNA/genética , Proteínas de Drosophila/genética , Imunidade Inata/genética , MicroRNAs/genética , Fatores de Transcrição/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Divisão Celular/genética , Proteínas de Ligação a DNA/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Homeostase/genética , Humanos , Transdução de Sinais/genética , Fatores de Transcrição/metabolismo , Transcrição Genética/genética
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