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1.
J Cell Sci ; 135(5)2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33414166

RESUMO

Ferroptosis is a regulated, non-apoptotic form of cell death, characterized by hydroxy-peroxidation of discrete phospholipid hydroperoxides, particularly hydroperoxyl (Hp) forms of arachidonoyl- and adrenoyl-phosphatidylethanolamine, with a downstream cascade of oxidative damage to membrane lipids, proteins and DNA, culminating in cell death. We recently showed that human trophoblasts are particularly sensitive to ferroptosis caused by depletion or inhibition of glutathione peroxidase 4 (GPX4) or the lipase PLA2G6. Here, we show that trophoblastic ferroptosis is accompanied by a dramatic change in the trophoblast plasma membrane, with macro-blebbing and vesiculation. Immunofluorescence revealed that ferroptotic cell-derived blebs stained positive for F-actin, but negative for cytoplasmic organelle markers. Transfer of conditioned medium that contained detached macrovesicles or co-culture of wild-type target cells with blebbing cells did not stimulate ferroptosis in target cells. Molecular modeling showed that the presence of Hp-phosphatidylethanolamine in the cell membrane promoted its cell ability to be stretched. Together, our data establish that membrane macro-blebbing is characteristic of trophoblast ferroptosis and can serve as a useful marker of this process. Whether or not these blebs are physiologically functional remains to be established.

2.
mSphere ; 6(2)2021 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-33853873

RESUMO

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has had a massive impact on human lives worldwide. While the airborne SARS-CoV-2 primarily affects the lungs, viremia is not uncommon. As placental trophoblasts are directly bathed in maternal blood, they are vulnerable to SARS-CoV-2. Intriguingly, the human fetus is largely spared from SARS-CoV-2 infection. We tested whether the human placenta expresses the main SARS-CoV-2 entry factors angiotensin-converting enzyme 2 (ACE2), transmembrane protease serine 2 (TMPRSS2), and furin and showed that ACE2 and TMPRSS2 are expressed in the trophoblast rather than in other placental villous cells. While furin is expressed in the main placental villous cell types, we surveyed, trophoblasts exhibit the highest expression. In line with the expression of these entry factors, we demonstrated that a SARS-CoV-2 pseudovirus could enter primary human trophoblasts. Mechanisms underlying placental defense against SARS-CoV-2 infection likely involve postentry processing, which may be germane for mitigating interventions against SARS-CoV-2.IMPORTANCE Pregnant women worldwide have been affected by COVID-19. As the virus is commonly spread to various organs via the bloodstream and because human placental trophoblasts are directly bathed in maternal blood, feto-placental infection by SARS-CoV-2 seems likely. However, despite the heightened risk to pregnant women, thus far the transmission risk of COVID-19 to the feto-placental unit seems extremely low. This has been recently attributed to a negligible expression of SARS-CoV-2 entry factors in the human placenta. We therefore sought to explore the expression of the entry factors ACE2 and TMPRSS2 in the different cell types of human placental villi. Using a combination of transcriptome sequencing (RNA-seq), real-time quantitative PCR (RT-qPCR), in situ hybridization, and immunofluorescence, we found that trophoblasts, but not the other main villous cell types, express ACE2 and TMPRSS2, with a broad expression of furin. Correspondingly, we also showed that primary human trophoblasts are permissive to entry of SARS-CoV-2 pseudovirus particles.


Assuntos
/metabolismo , Furina/metabolismo , Receptores Virais/metabolismo , Serina Endopeptidases/metabolismo , Trofoblastos/metabolismo , Células Cultivadas , Feminino , Feto/virologia , Humanos , Gravidez , Complicações Infecciosas na Gravidez/virologia , Internalização do Vírus
3.
Sci Adv ; 7(1)2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33523836

RESUMO

Liquid droplets have been studied for decades and have recently experienced renewed attention as a simplified model for numerous fascinating physical phenomena occurring on size scales from the cell nucleus to stellar black holes. Here, we present an acoustofluidic centrifugation technique that leverages an entanglement of acoustic wave actuation and the spin of a fluidic droplet to enable nanoparticle enrichment and separation. By combining acoustic streaming and droplet spinning, rapid (<1 min) nanoparticle concentration and size-based separation are achieved with a resolution sufficient to identify and isolate exosome subpopulations. The underlying physical mechanisms have been characterized both numerically and experimentally, and the ability to process biological samples (including DNA segments and exosome subpopulations) has been successfully demonstrated. Together, this acoustofluidic centrifuge overcomes existing limitations in the manipulation of nanoscale (<100 nm) bioparticles and can be valuable for various applications in the fields of biology, chemistry, engineering, material science, and medicine.

4.
Cell Rep ; 34(4): 108672, 2021 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-33503419

RESUMO

Extracellular vesicles (EVs) are increasingly appreciated as a mechanism of communication among cells that contribute to many physiological processes. Although EVs can promote either antiviral or proviral effects during viral infections, the role of EVs in virus-associated polymicrobial infections remains poorly defined. We report that EVs secreted from airway epithelial cells during respiratory viral infection promote secondary bacterial growth, including biofilm biogenesis, by Pseudomonas aeruginosa. Respiratory syncytial virus (RSV) increases the release of the host iron-binding protein transferrin on the extravesicular face of EVs, which interact with P. aeruginosa biofilms to transfer the nutrient iron and promote bacterial biofilm growth. Vesicular delivery of iron by transferrin more efficiently promotes P. aeruginosa biofilm growth than soluble holo-transferrin delivered alone. Our findings indicate that EVs are a nutrient source for secondary bacterial infections in the airways during viral infection and offer evidence of transkingdom communication in the setting of polymicrobial infections.

5.
Placenta ; 102: 34-38, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33218576

RESUMO

The discovery of regulated trafficking of extracellular vesicles (EVs) has added a new dimension to our understanding of local and distant communication among cells and tissues. Notwithstanding the expanded landscape of EV subtypes, the majority of research in the field centers on small and large EVs that are commonly termed exosomes, microvesicles and apoptotic cell-derived vesicles. In the context of pregnancy, EV-based communication has a special role in the crosstalk among the placenta, maternal and fetal compartments, with most studies focusing on trophoblastic EVs and their effect on other placental cell types, endothelial cells, and distant tissues. Many unanswered questions in the field of EV biology center on the mechanisms of vesicle biogenesis, loading of cargo molecules, EV release and trafficking, the interaction of EVs with target cells and the endocytic pathways underlying their uptake, and the intracellular processing of EVs inside target cells. These questions are directly relevant to EV-based placental-maternal-fetal communication and have unique implications in the context of interaction between two organisms. Despite rapid progress in the field, the number of speculative, unsubstantiated assumptions about placental EVs is concerning. Here we attempt to delineate existing knowledge in the field, focusing primarily on placental small EVs (exosomes). We define central questions that require investigative attention in order to advance the field.

6.
J Cell Sci ; 134(5)2020 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-33093239

RESUMO

The function of microRNAs (miRNAs) can be cell autonomous or communicated to other cell types and has been implicated in diverse biological processes. We previously demonstrated that miR-517a-3p (miR-517a), a highly expressed member of the chromosome 19 miRNA cluster (C19MC) that is transcribed almost exclusively in human trophoblasts, attenuates viral replication via induction of autophagy in non-trophoblastic recipient cells. However, the molecular mechanisms underlying these effects remain unknown. Here, we identified unc-13 homolog D (UNC13D) as a direct, autophagy-related gene target of miR-517a, leading to repression of UNC13D. In line with the antiviral activity of miR-517a, silencing UNC13D suppressed replication of vesicular stomatitis virus (VSV), whereas overexpression of UNC13D increased VSV levels, suggesting a role for UNC13D silencing in the antiviral activity of miR-517a. We also found that miR-517a activated NF-κB signaling in HEK-293XL cells expressing TLR8, but the effect was not specific to C19MC miRNA. Taken together, our results define mechanistic pathways that link C19MC miRNA with inhibition of viral replication.

7.
Am J Reprod Immunol ; : e13345, 2020 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-32939907

RESUMO

Cells produce cytoplasmic vesicles to facilitate the processing and transport of RNAs, proteins, and other signaling molecules among intracellular organelles. Moreover, most cells release a range of extracellular vesicles (EVs) that mediate intercellular communication in both physiological and pathological settings. In addition to a better understanding of their biological functions, the diagnostic and therapeutic prospects of EVs, particularly the nano-sized small EVs (sEVs, exosomes), are currently being rigorously pursued. While EVs and viruses such as retroviruses might have evolved independently, they share a number of similar characteristics, including biogenesis pathways, size distribution, cargo, and cell-targeting mechanisms. The interplay of EVs with viruses has profound effects on viral replication and infectivity. Our research indicates that sEVs, produced by primary human trophoblasts, can endow other non-placental cell types with antiviral response. Better insights into the interaction of EVs with viruses may illuminate new ways to attenuate viral infections during pregnancy, and perhaps develop new antiviral therapeutics to protect the feto-placental unit during critical times of human development.

8.
J Extracell Vesicles ; 9(1): 1812261, 2020 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-32944196

RESUMO

Pregnancy is a unique situation, in which placenta-derived small extracellular vesicles (sEVs) may communicate with maternal and foetal tissues. While relevant to homoeostatic and pathological functions, the mechanisms underlying sEV entry and cargo handling in target cells remain largely unknown. Using fluorescently or luminescently labelled sEVs, derived from primary human placental trophoblasts or from a placental cell line, we interrogated the endocytic pathways used by these sEVs to enter relevant target cells, including the neighbouring primary placental fibroblasts and human uterine microvascular endothelial cells. We found that trophoblastic sEVs can enter target cells, where they retain biological activity. Importantly, using a broad series of pharmacological inhibitors and siRNA-dependent silencing approaches, we showed that trophoblastic sEVs enter target cells using macropinocytosis and clathrin-mediated endocytosis pathways, but not caveolin-dependent endocytosis. Tracking their intracellular course, we localized the sEVs to early endosomes, late endosomes, and lysosomes. Finally, we used coimmunoprecipitation to demonstrate the association of the sEV microRNA (miRNA) with the P-body proteins AGO2 and GW182. Together, our data systematically detail endocytic pathways used by placental sEVs to enter relevant fibroblastic and endothelial target cells, and provide support for "endocytic escape" of sEV miRNA to P-bodies, a key site for cytoplasmic RNA regulation.

9.
Lab Chip ; 20(18): 3472, 2020 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-32812585

RESUMO

Correction for 'Separating extracellular vesicles and lipoproteins via acoustofluidics' by Mengxi Wu et al., Lab Chip, 2019, 19, 1174-1182, DOI: .

10.
Hypertension ; 75(3): 762-771, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31983308

RESUMO

Although preeclampsia is a common and serious complication of pregnancy, insight into its pathobiology and diagnosis is lacking. Circulating plasma exosomes, which contain RNA and other molecules and have recently become accessible for diagnostics, may be informative in this regard. We tested the hypothesis that preeclampsia may affect the miRNA cargo within circulating maternal blood exosomes. We collected plasma from 60 pregnant women at term, including 20 women with pregnancy complicated by preeclampsia, and 20 women with fetal growth restriction and 20 with healthy pregnancy, serving as controls. We isolated exosomes from the maternal plasma by continuous density gradient ultracentrifugation. Our main outcome variable was exosomal miRNA cargo, analyzed by quantitative polymerase chain reaction-based TaqMan advanced miRNA assay in a card format and the expression of differentially expressed exosomal miRNA in whole plasma from the same participants. We found that 7 miRNA species were differentially expressed in exosomes from women with preeclampsia and those from controls. In contrast, there was no significant difference in exosomal miRNA expression between women with fetal growth restriction and controls. The results were not affected by fetal sex. Only one of the preeclampsia-related, differentially expressed exosomal miRNAs was significantly different in whole plasma miRNA analysis. We concluded that unlike whole plasma miRNA, exosomes extracted from the plasma of women with preeclampsia exhibit a unique miRNA profile, suggesting that plasma exosomal miRNA could provide insight into the pathophysiology of preeclampsia, and may play a role in disease diagnostics.

11.
Lab Chip ; 19(7): 1174-1182, 2019 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-30806400

RESUMO

Extracellular vesicles (EVs) and lipoproteins are abundant and co-exist in blood. Both have been proven to be valuable as diagnostic biomarkers and for therapeutics. However, EVs and lipoproteins are both on the submicron scale and overlap in size distributions. Conventional methods to separate EVs and lipoproteins are inefficient and time-consuming. Here we present an acoustofluidic-based separation technique that is based on the acoustic property differences of EVs and lipoproteins. By using the acoustofluidic technology, EVs and subgroups of lipoproteins are separated in a label-free, contact-free, and continuous manner. With its ability for simple, rapid, efficient, continuous-flow isolation, our acoustofluidic technology could be a valuable tool for health monitoring, disease diagnosis, and personalized medicine.


Assuntos
Acústica/instrumentação , Vesículas Extracelulares/metabolismo , Dispositivos Lab-On-A-Chip , Lipoproteínas/isolamento & purificação , Dimetilpolisiloxanos , Desenho de Equipamento , Humanos , Nylons , Fatores de Tempo
12.
Placenta ; 61: 33-38, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29277269

RESUMO

INTRODUCTION: Cultured primary human trophoblasts (PHT), derived from term placentas, are relatively resistant to infection by diverse viruses. The resistance can be conferred to non-trophoblastic cells by pre-exposing them to medium that was conditioned by PHT cells. This antiviral effect is mediated, at least in part, by microRNAs (miRNA) expressed from the chromosome 19 microRNA cluster (C19MC). Recently we showed that PHT cells and cells pre-exposed to PHT medium are also resistant to infection by Zika virus (ZIKV), an effect mediated by the constitutive release of the type III interferons (IFN) IFN lambda-1 and IFN lambda-2 in trophoblastic medium. We hypothesized that trophoblastic C19MC miRNA are active against ZIKV, and assessed the interaction of this pathway with IFN lambda-1 - mediated resistance. METHODS: Term PHT cells were cultured using standard techniques. An osteosarcoma cell line (U2OS) was used as non-trophoblastic cells, which were infected with either ZIKV or vesicular stomatitis virus (VSV). Trophoblastic extracellular vesicles (EVs) were produced by gradient ultracentrifugation. RT-qPCR was used to determine viral infection, cellular or medium miRNA levels and the expression of interferon-stimulated genes. RESULTS: We showed that C19MC miRNA attenuate infection of U2OS cells by ZIKV, and that C19MC miRNA or exosomes that contain C19MC miRNA did not influence the type III IFN pathway. Similarly, cell exposure to recombinant IFN lambda-1 had no effect on miRNA expression, and these pathways did not exhibit synergistic interaction. DISCUSSION: PHT cells exert antiviral activity by at least two independent mechanisms, mediated by C19MC miRNA and by type III IFNs.


Assuntos
Cromossomos Humanos Par 19/metabolismo , Imunidade , MicroRNAs/metabolismo , Família Multigênica , Placenta/metabolismo , Trofoblastos/metabolismo , Zika virus/imunologia , Adulto , Diferenciação Celular , Linhagem Celular Tumoral , Células Cultivadas , Meios de Cultivo Condicionados/metabolismo , Exossomos/imunologia , Exossomos/metabolismo , Exossomos/patologia , Exossomos/virologia , Vesículas Extracelulares/imunologia , Vesículas Extracelulares/metabolismo , Vesículas Extracelulares/patologia , Vesículas Extracelulares/virologia , Feminino , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Interferons/genética , Interferons/metabolismo , Placenta/citologia , Placenta/imunologia , Placenta/virologia , Gravidez , Isoformas de Proteínas/metabolismo , Proteínas Recombinantes/metabolismo , Trofoblastos/citologia , Trofoblastos/imunologia , Trofoblastos/virologia , Zika virus/fisiologia , Infecção por Zika virus/imunologia , Infecção por Zika virus/metabolismo , Infecção por Zika virus/patologia , Infecção por Zika virus/virologia
13.
Proc Natl Acad Sci U S A ; 114(40): 10584-10589, 2017 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-28923936

RESUMO

Exosomes are nanoscale extracellular vesicles that play an important role in many biological processes, including intercellular communications, antigen presentation, and the transport of proteins, RNA, and other molecules. Recently there has been significant interest in exosome-related fundamental research, seeking new exosome-based biomarkers for health monitoring and disease diagnoses. Here, we report a separation method based on acoustofluidics (i.e., the integration of acoustics and microfluidics) to isolate exosomes directly from whole blood in a label-free and contact-free manner. This acoustofluidic platform consists of two modules: a microscale cell-removal module that first removes larger blood components, followed by extracellular vesicle subgroup separation in the exosome-isolation module. In the cell-removal module, we demonstrate the isolation of 110-nm particles from a mixture of micro- and nanosized particles with a yield greater than 99%. In the exosome-isolation module, we isolate exosomes from an extracellular vesicle mixture with a purity of 98.4%. Integrating the two acoustofluidic modules onto a single chip, we isolated exosomes from whole blood with a blood cell removal rate of over 99.999%. With its ability to perform rapid, biocompatible, label-free, contact-free, and continuous-flow exosome isolation, the integrated acoustofluidic device offers a unique approach to investigate the role of exosomes in the onset and progression of human diseases with potential applications in health monitoring, medical diagnosis, targeted drug delivery, and personalized medicine.


Assuntos
Acústica , Células Sanguíneas/química , Exossomos/química , Técnicas Analíticas Microfluídicas/instrumentação , Técnicas Analíticas Microfluídicas/métodos , Células Sanguíneas/citologia
14.
Placenta ; 47: 86-95, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27780544

RESUMO

INTRODUCTION: Primary human trophoblasts release a repertoire of extracellular vesicles (EVs). Among them are nano-sized exosomes, which we found to suppress the replication of a wide range of diverse viruses. These exosomes contain trophoblastic microRNAs (miRNAs) that are expressed from the chromosome 19 miRNA cluster and exhibit antiviral properties. Here, we report our investigation of the cargo of placental EVs, focusing on the composition and the antiviral properties of exosomes, microvesicles, and apoptotic blebs. METHODS: We isolated EVs using ultracentrifugation and defined their purity using immunoblotting, electron microscopy, and nanoparticle tracking. We used liquid chromatography-electrospray ionization-mass spectrometry, protein mass spectrometry, and miRNA TaqMan card PCR to examine the phospholipids, proteins, and miRNA cargo of trophoblastic EVs and an in vitro viral infection assay to assess the antiviral properties of EVs. RESULTS: We found that all three EV types contain a comparable repertoire of miRNA. Interestingly, trophoblastic exosomes harbor a protein and phospholipid profile that is distinct from that of microvesicles or apoptotic blebs. Functionally, trophoblastic exosomes exhibit the highest antiviral activity among the EVs. Consistently, plasma exosomes derived from pregnant women recapitulate the antiviral effect of trophoblastic exosomes derived from in vitro cultures of primary human trophoblasts. DISCUSSION: When compared to other trophoblastic EVs, exosomes exhibit a unique repertoire of proteins and phospholipids, but not miRNAs, and a potent viral activity. Our work suggests that human trophoblastic EVs may play a key role in maternal-placental-fetal communication.


Assuntos
Exossomos/metabolismo , Vesículas Extracelulares/metabolismo , MicroRNAs/metabolismo , Placenta/metabolismo , Trofoblastos/metabolismo , Feminino , Humanos , Espectrometria de Massas , Fosfolipídeos/metabolismo , Placenta/citologia , Gravidez , Trofoblastos/citologia
15.
Cell Host Microbe ; 19(5): 705-12, 2016 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-27066743

RESUMO

During mammalian pregnancy, the placenta acts as a barrier between the maternal and fetal compartments. The recently observed association between Zika virus (ZIKV) infection during human pregnancy and fetal microcephaly and other anomalies suggests that ZIKV may bypass the placenta to reach the fetus. This led us to investigate ZIKV infection of primary human trophoblasts (PHTs), which are the barrier cells of the placenta. We discovered that PHT cells from full-term placentas are refractory to ZIKV infection. In addition, medium from uninfected PHT cells protects non-placental cells from ZIKV infection. PHT cells constitutively release the type III interferon (IFN) IFNλ1, which functions in both a paracrine and autocrine manner to protect trophoblast and non-trophoblast cells from ZIKV infection. Our data suggest that for ZIKV to access the fetal compartment, it must evade restriction by trophoblast-derived IFNλ1 and other trophoblast-specific antiviral factors and/or use alternative strategies to cross the placental barrier.


Assuntos
Interferons/biossíntese , Interferons/imunologia , Placenta/imunologia , Trofoblastos/imunologia , Infecção por Zika virus/prevenção & controle , Animais , Linhagem Celular Tumoral , Células Cultivadas , Chlorocebus aethiops , Feminino , Doenças Fetais/imunologia , Doenças Fetais/prevenção & controle , Doenças Fetais/virologia , Humanos , Interferons/farmacologia , Interleucinas/genética , Interleucinas/metabolismo , Interleucinas/farmacologia , Microcefalia/imunologia , Microcefalia/prevenção & controle , Microcefalia/virologia , Placenta/citologia , Placenta/metabolismo , Gravidez , Complicações Infecciosas na Gravidez/imunologia , Complicações Infecciosas na Gravidez/prevenção & controle , Complicações Infecciosas na Gravidez/virologia , Trofoblastos/citologia , Trofoblastos/metabolismo , Células Vero , Zika virus/efeitos dos fármacos , Zika virus/imunologia , Infecção por Zika virus/imunologia
16.
Am J Obstet Gynecol ; 213(4 Suppl): S163-72, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26428496

RESUMO

MicroRNAs (miRNAs) constitute a large family of small noncoding RNAs that are encoded by the genomes of most organisms. They regulate gene expression through posttranscriptional mechanisms to attenuate protein output in various genetic networks. The discovery of miRNAs has transformed our understanding of gene regulation and sparked intense efforts intended to harness their potential as diagnostic markers and therapeutic tools. Over the last decade, a flurry of studies has shed light on placental miRNAs but has also raised many questions regarding the scope of their biologic action. Moreover, the recognition that miRNAs of placental origin are released continually in the maternal circulation throughout pregnancy suggested that circulating miRNAs might serve as biomarkers for placental function during pregnancy. Although this generated much enthusiasm, recently recognized challenges have delayed the application of miRNA-based biomarkers and therapeutics in clinical practice. In this review, we summarize key findings in the field and discuss current knowledge related to miRNAs in the context of placental biology.


Assuntos
MicroRNAs/fisiologia , Doenças Placentárias/genética , Biomarcadores/sangue , Espaço Extracelular/metabolismo , Feminino , Humanos , MicroRNAs/sangue , Doenças Placentárias/sangue , Gravidez
17.
Cold Spring Harb Perspect Med ; 5(8): a023036, 2015 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-25877393

RESUMO

In eutherian organisms, the placenta interfaces the fetal and maternal environments. Located at the placental villous surface, in direct contact with maternal blood, is the trophoblast layer, which mediates the crucial maternal-fetal exchange of gases, nutrients, and waste products, produces hormones that support the pregnancy, and provides immunologic defense. Discovery of microRNAs (miRNAs) and their role in development, differentiation, and homeostatic resilience has increased our understanding of genomic and epigenomic networks that regulate placental function. Moreover, unique miRNA species, which are expressed by human trophoblasts and are termed "trophomiRs," may show specialized functions during normal and pathological pregnancies. Placental miRNAs, packaged within exosomes and other vesicles or bound in protein complexes, are capable of communicating distinctive signals to maternal and/or fetal tissues. Additional research may usher in the use of circulating miRNAs as pregnancy-related disease biomarkers, providing new diagnostic and therapeutic options during pregnancy.


Assuntos
Regulação da Expressão Gênica , MicroRNAs/metabolismo , Placenta/metabolismo , Trofoblastos/metabolismo , Exossomos/genética , Exossomos/metabolismo , Feminino , Marcadores Genéticos , Humanos , MicroRNAs/genética , Placenta/fisiopatologia , Doenças Placentárias/genética , Doenças Placentárias/fisiopatologia , Gravidez , Sensibilidade e Especificidade
18.
Int J Dev Biol ; 58(2-4): 281-9, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25023694

RESUMO

During the past decade, various types of small non-coding RNAs were found to be expressed in all kingdoms and phyla of life. Intense research efforts have begun to shed light on their biological functions, although much remains to be determined in order to fully characterize their scope of biological action. Typically, small RNAs provide sequence specificity to a protein complex that is driven to silence a long target RNA. MicroRNAs (miRNAs) are small RNAs that are coded in the genome of most eukaryotes, and contribute to the cellular identity by regulating cell-specific gene networks by translational repression or degradation of mRNA. These effects commonly fine-tune gene expression associated with developmental or environmental cues. Different cell types can be characterized by their distinctive cellular miRNA landscape. The human placenta expresses a unique set of miRNAs, a high proportion of which is derived from a large cluster located on chromosome 19, (termed chromosome 19 miRNA cluster, or C19MC). Interestingly, a fraction of these placenta-enriched miRNAs are released to the extracellular environment through exosomes that were recently found to induce an antiviral immunity. In this review, we explore relevant placental viral infections and discuss the antiviral role of exosome-packaged placental C19MC miRNAs in this context.


Assuntos
Exossomos/genética , Regulação da Expressão Gênica , MicroRNAs/genética , Placenta/metabolismo , Placenta/virologia , Trofoblastos/fisiologia , Animais , Feminino , Humanos , Gravidez , Trofoblastos/citologia
19.
Proc Natl Acad Sci U S A ; 110(29): 12048-53, 2013 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-23818581

RESUMO

Placental trophoblasts form the interface between the fetal and maternal environments and serve to limit the maternal-fetal spread of viruses. Here we show that cultured primary human placental trophoblasts are highly resistant to infection by a number of viruses and, importantly, confer this resistance to nonplacental recipient cells by exosome-mediated delivery of specific microRNAs (miRNAs). We show that miRNA members of the chromosome 19 miRNA cluster, which are almost exclusively expressed in the human placenta, are packaged within trophoblast-derived exosomes and attenuate viral replication in recipient cells by the induction of autophagy. Together, our findings identify an unprecedented paracrine and/or systemic function of placental trophoblasts that uses exosome-mediated transfer of a unique set of placental-specific effector miRNAs to directly communicate with placental or maternal target cells and regulate their immunity to viral infections.


Assuntos
Autofagia/genética , Cromossomos Humanos Par 19/genética , Resistência à Doença/genética , MicroRNAs/genética , Placenta/citologia , Trofoblastos/virologia , Viroses/transmissão , Análise de Variância , Células Cultivadas , Ensaio de Imunoadsorção Enzimática , Exossomos/genética , Exossomos/metabolismo , Feminino , Proteínas de Fluorescência Verde , Humanos , Placenta/metabolismo , Gravidez , Trofoblastos/metabolismo
20.
PLoS One ; 6(11): e28098, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22140513

RESUMO

Accumulating evidence suggests that tumor-initiating stem cells or cancer stem cells (CSCs) possibly originating from normal stem cells may be the root cause of certain malignancies. How stem cell homeostasis is impaired in tumor tissues is not well understood, although certain tumor suppressors have been implicated. In this study, we use the Drosophila neural stem cells (NSCs) called neuroblasts as a model to study this process. Loss-of-function of Numb, a key cell fate determinant with well-conserved mammalian counterparts, leads to the formation of ectopic neuroblasts and a tumor phenotype in the larval brain. Overexpression of the Drosophila tumor suppressor p53 (dp53) was able to suppress ectopic neuroblast formation caused by numb loss-of-function. This occurred in a non-apoptotic manner and was independent of Dacapo, the fly counterpart of the well-characterized mammalian p53 target p21 involved in cellular senescence. The observation that dp53 affected Edu incorporation into neuroblasts led us to test the hypothesis that dp53 acts through regulation of factors involved in cell cycle progression. Our results show that the inhibitory effect of dp53 on ectopic neuroblast formation was mediated largely through its regulation of Cyclin E (Cyc E). Overexpression of Cyc E was able to abrogate dp53's ability to rescue numb loss-of-function phenotypes. Increasing Cyc E levels by attenuating Archipelago (Ago), a recently identified transcriptional target of dp53 and a negative regulator of Cyc E, had similar effects. Conversely, reducing Cyc E activity by overexpressing Ago blocked ectopic neuroblast formation in numb mutant. Our results reveal an intimate connection between cell cycle progression and NSC self-renewal vs. differentiation control, and indicate that p53-mediated regulation of ectopic NSC self-renewal through the Ago/Cyc E axis becomes particularly important when NSC homeostasis is perturbed as in numb loss-of-function condition. This has important clinical implications.


Assuntos
Apoptose , Encéfalo/citologia , Ciclina E/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/citologia , Proteínas F-Box/metabolismo , Células-Tronco Neurais/citologia , Proteína Supressora de Tumor p53/metabolismo , Animais , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Drosophila melanogaster/metabolismo , Homeostase , Hormônios Juvenis/metabolismo , Modelos Biológicos , Mutação/genética , Células-Tronco Neurais/metabolismo , Fenótipo , Homologia de Sequência de Aminoácidos
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