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1.
Stem Cell Rev Rep ; 20(4): 996-1014, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38457061

RESUMO

The placenta stands out as a unique, transitory, and multifaceted organ, essential to the optimal growth and maturation of the fetus. Functioning as a vital nexus between the maternal and fetal circulatory systems, it oversees the critical exchange of nutrients and waste. This exchange is facilitated by placental cells, known as trophoblasts, which adeptly invade and remodel uterine blood vessels. Deviations in placental development underpin a slew of pregnancy complications, notably fetal growth restriction (FGR), preeclampsia (PE), recurrent spontaneous abortions (RSA), and preterm birth. Central to placental function and development is epigenetic regulation. Despite its importance, the intricate mechanisms by which epigenetics influence the placenta are not entirely elucidated. Recently, the scientific community has turned its focus to parsing out the epigenetic alterations during placental development, such as variations in promoter DNA methylation, genomic imprints, and shifts in non-coding RNA expression. By establishing correlations between epigenetic shifts in the placenta and pregnancy complications, researchers are unearthing invaluable insights into the biology and pathophysiology of these conditions. This review seeks to synthesize the latest findings on placental epigenetic regulation, spotlighting its crucial role in shaping fetal growth trajectories and development. Through this lens, we underscore the overarching significance of the placenta in the larger narrative of gestational health.


Assuntos
Epigênese Genética , Placenta , Placentação , Resultado da Gravidez , Humanos , Gravidez , Feminino , Placentação/genética , Placenta/metabolismo , Resultado da Gravidez/genética , Metilação de DNA/genética , Retardo do Crescimento Fetal/genética , Retardo do Crescimento Fetal/patologia , Animais
2.
Front Immunol ; 14: 1200245, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37920470

RESUMO

Cyclic GMP-AMP synthetase (cGAS), recognized as the primary DNA sensor within cells, possesses the capability to identify foreign DNA molecules along with free DNA fragments. This identification process facilitates the production of type I IFNs through the activator of the interferon gene (STING) which induces the phosphorylation of downstream transcription factors. This action characterizes the most archetypal biological functionality of the cGAS-STING pathway. When treated with anti-tumor agents, cells experience DNA damage that triggers activation of the cGAS-STING pathway, culminating in the expression of type I IFNs and associated downstream interferon-stimulated genes. cGAS-STING is one of the important innate immune pathways,the role of type I IFNs in the articulation between innate immunity and T-cell antitumour immunity.type I IFNs promote the recruitment and activation of inflammatory cells (including NK cells) at the tumor site.Type I IFNs also can promote the activation and maturation of dendritic cel(DC), improve the antigen presentation of CD4+T lymphocytes, and enhance the cross-presentation of CD8+T lymphocytes to upregulating anti-tumor responses. This review discussed the cGAS-STING signaling and its mechanism and biological function in traditional tumor therapy and immunotherapy.


Assuntos
Interferon Tipo I , Neoplasias , Humanos , Nucleotidiltransferases/metabolismo , Imunidade Inata , DNA , Transdução de Sinais , Interferon Tipo I/metabolismo , Neoplasias/terapia
3.
Langmuir ; 39(37): 13028-13037, 2023 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-37671509

RESUMO

Water scarcity presents a pressing global challenge, necessitating innovative solutions, such as the collection of water from the air using conical structures. However, current research primarily focuses on mist collection rather than on nanoscale clusters of water molecules. Under standard atmospheric conditions, water vapor predominantly exists as imperceptible clusters. Therefore, it is crucial to investigate the interactions between these water molecule clusters and conical structures, particularly regarding whether the conical shape induces Laplace pressure difference on the adhering cluster formations. To gain deeper insights and determine optimal droplet collection structures, we conducted molecular dynamics simulations to investigate interactions between water molecule clusters and conical structures. Our investigations focused on studying the interactions between conical structures and water molecule clusters with varying densities, as well as the impact of surface energies on the collection of water by these conical structures. Notably, our simulations unveiled the significant roles played by van der Waals forces and Laplace pressure in the process of collecting water molecule clusters. Furthermore, our simulations revealed that Janus conical structures, featuring two distinct surface energy regions, played a crucial role in promoting the aggregation of water molecules, resulting in the formation of larger droplets. This aggregation was driven by surface tension gradients, which arise from the contrasting wetting properties in different regions of the Janus structure. As a consequence, under the influence of gravitational forces, these larger droplets could eventually detach from the structure. Through the combined effects of surface tension gradients and gravitational forces, Janus conical structures offer a promising avenue for enhancing the collection efficiency of water from the air. Our research sheds light on the fundamental mechanisms governing water molecule cluster-based water collection and provides valuable insights for the design of more efficient and effective water collection systems.

4.
Stem Cell Res Ther ; 11(1): 225, 2020 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-32513263

RESUMO

BACKGROUND: Acetaminophen (APAP) overdose is the common cause of acute liver failure (ALF) due to the oxidative damage of multiple cellular components. This study aimed to investigate whether plasma membrane vesicles (PMVs) from human umbilical cord mesenchymal stem cells (hUCMSCs) could be exploited as a novel stem cell therapy for APAP-induced liver injury. METHODS: PMVs from hUCMSCs were prepared with an improved procedure including a chemical enucleation step followed by a mechanical extrusion. PMVs of hUCMSCs were characterized and supplemented to hepatocyte cultures. Rescue of APAP-induced hepatocyte damage was evaluated. RESULTS: The hUCMSCs displayed typical fibroblastic morphology and multipotency when cultivated under adipogenic, osteogenic, or chondrogenic conditions. PMVs of hUCMSCs maintained the stem cell phenotype, including the presence of CD13, CD29, CD44, CD73, and HLA-ABC, but the absence of CD45, CD117, CD31, CD34, and HLA-DR on the plasma membrane surface. RT-PCR and transcriptomic analyses showed that PMVs were similar to hUCMSCs in terms of mRNA profile, including the expression of stemness genes GATA4/5/6, Nanog, and Oct1/2/4. GO term analysis showed that the most prominent reduced transcripts in PMVs belong to integral membrane components, extracellular vesicular exosome, and extracellular matrix. Immunofluorescence labeling/staining and confocal microscopy assays showed that PMVs enclosed cellular organelles, including mitochondria, lysosomes, proteasomes, and endoplasmic reticula. Incorporation of the fusogenic VSV-G viral membrane glycoprotein stimulated the endosomal release of PMV contents into the cytoplasm. Further, the addition of PMVs and a mitochondrial-targeted antioxidant Mito-Tempo into cultures of APAP-treated HepG2 cells resulted in reduced cell death, enhanced viability, and increased mitochondrial membrane potential. Lastly, this study demonstrated that the redox state and activities of aminotransferases were restored in APAP-treated HepG2 cells. CONCLUSIONS: The results suggest that PMVs from hUCMSCs could be used as a novel stem cell therapy for the treatment of APAP-induced liver injury.


Assuntos
Acetaminofen , Células-Tronco Mesenquimais , Acetaminofen/toxicidade , Diferenciação Celular , Membrana Celular , Terapia Baseada em Transplante de Células e Tecidos , Células Hep G2 , Humanos , Cordão Umbilical
5.
Eur J Cell Biol ; 98(5-8): 151045, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31563281

RESUMO

Enucleated mammalian cells (cytoplasts) have been widely used for studying differential roles of the cytoplasm and nucleus in various cellular processes. Here, we reported an improved enucleation protocol, in which cells were seeded in extracellular matrix (ECM)-coated 24-wells and spun at 4600 g and 35 °C for 60 min in the presence of cytochalasin B and colchicine. When glass-bottom wells were used, cellular structures and organelles in cytoplasts could be examined directly by confocal microscopy. Nuclear envelope rupture did not occur probably due to mild centrifugation conditions used in this study. Addition of paclitaxel or doxorubicin completely blocked proliferation of residual nucleated cells; however, to our surprise, paclitaxel dramatically prolonged the survival of cytoplasts. Results from Annexin V and Propidium Iodide staining showed that cytoplasts died predominantly by apoptosis, which was partially inhibited by ECM and further by paclitaxel. Mitochondria were mostly rod-shaped and formed a connected network in paclitaxel-treated cytoplasts, indicating lack of fusion and fission dynamics. Moreover, paclitaxel increased mitochondrial membrane potential, suggesting that perturbation of mitochondria might be critical to the survival of cytoplasts. In conclusion, we had established an efficient and fast procedure for enucleation of adherent animal cells, which could facilitate the investigation of nucleocytoplasmic interaction.


Assuntos
Núcleo Celular/metabolismo , Colchicina/metabolismo , Citoplasma/metabolismo , Matriz Extracelular/metabolismo , Linhagem Celular Tumoral , Núcleo Celular/química , Colchicina/química , Citoplasma/química , Matriz Extracelular/química , Humanos , Imagem Óptica
6.
J Vis Exp ; (123)2017 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-28570530

RESUMO

We have previously reported on the generation of plasma membrane vesicles (PMVs) through the mechanical extrusion of mammalian cells. The fusion of PMVs with mitochondrial deficient Rho0 cells restored mitotic activity under normal culture conditions. Atherosclerosis, type 2 diabetes, Alzheimer's disease, and cancer are age-related diseases that have been reported to be associated with multiple mechanical and functional defects in the cytosol and organelles of a variety of cell types. Bone marrow mesenchymal stem cells (BMSCs) represent a unique cell population from the bone marrow that possess self-renewal capabilities while maintaining their multipotency. The supplementation of senescence cells with young cytoplasm from autologous BMSCs via the fusion of PMVs provides a promising approach to ameliorate or even reverse age-associated phenotypes. This protocol describes how to prepare PMVs from BMSCs via extrusion through a polycarbonate membrane with 3 µm pores, determine the existence of mitochondria and examine the maintenance of membrane potential within PMVs using a confocal microscope, concentrate PMVs by centrifugation, and carry out the in vivo injection of PMVs into the gastrocnemius muscle of mice.


Assuntos
Micropartículas Derivadas de Células/transplante , Citoplasma/transplante , Células-Tronco Mesenquimais/citologia , Animais , Fusão Celular , Membrana Celular/ultraestrutura , Potencial da Membrana Mitocondrial , Camundongos , Camundongos Endogâmicos BALB C , Cimento de Policarboxilato
7.
J Colloid Interface Sci ; 412: 24-30, 2013 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-24144370

RESUMO

A series of salt-free catanionic surface active ionic liquids (SAILs), 1-alkyl-3-methylimidazolim alkyl sulfates (denoted as [Cnmim][CmSO4], n=6, 8, 10; m=12 and n=4; m=10, 14) were synthesized by an ion exchange reaction and their surface properties in aqueous solution were examined systematically by surface tension, fluorescence and electrical conductivity measurements. As catanionic surfactants, these SAILs exhibit notably higher surface activity, compared to the cationic or anionic analogues. Increment in both cationic and anionic alkyl chain lengths for [Cnmim][CmSO4] can both improve the amphiphilic character remarkably. This can be ascribed to cooperative interactions as formation of catanionic pairs between alkyl-substituted imidazolium cations and alkyl sulfate anions. The negative micellization Gibbs free energy values prove that the micellization of all the 1-alkyl-3-methylimidazolim alkyl sulfates investigated is a spontaneous process. Any additional CH2 group makes the micellization process easier regardless if it is on a cation or an anion. When keeping the total carbon atom number constant, we find that the [Cnmim][CmSO4] molecules with greater asymmetric alkyl chains display superior surface activity. This work indicates that the self-assembly of these imidazolium-based salt-free catanionic SAILs can be tailored by adjusting the mismatch of alkyl chains. These SAILs are expected to have potential applications in the fields of colloidal and interface and nanomaterial synthesis.

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