RESUMO
Cities are generally warmer than their adjacent rural land, a phenomenon known as the urban heat island (UHI). Often accompanying the UHI effect is another phenomenon called the urban dry island (UDI), whereby the humidity of urban land is lower than that of the surrounding rural land1-3. The UHI exacerbates heat stress on urban residents4,5, whereas the UDI may instead provide relief because the human body can cope with hot conditions better at lower humidity through perspiration6,7. The relative balance between the UHI and the UDI-as measured by changes in the wet-bulb temperature (Tw)-is a key yet largely unknown determinant of human heat stress in urban climates. Here we show that Tw is reduced in cities in dry and moderately wet climates, where the UDI more than offsets the UHI, but increased in wet climates (summer precipitation of more than 570 millimetres). Our results arise from analysis of urban and rural weather station data across the world and calculations with an urban climate model. In wet climates, the urban daytime Tw is 0.17 ± 0.14 degrees Celsius (mean ± 1 standard deviation) higher than rural Tw in the summer, primarily because of a weaker dynamic mixing in urban air. This Tw increment is small, but because of the high background Tw in wet climates, it is enough to cause two to six extra dangerous heat-stress days per summer for urban residents under current climate conditions. The risk of extreme humid heat is projected to increase in the future, and these urban effects may further amplify the risk.
Assuntos
Cidades , Clima , Transtornos de Estresse por Calor , Temperatura Alta , Umidade , Chuva , Humanos , Cidades/epidemiologia , Temperatura Alta/efeitos adversos , Tempo (Meteorologia) , Umidade/efeitos adversos , Fatores de Risco , Transtornos de Estresse por Calor/epidemiologia , Transtornos de Estresse por Calor/etiologia , Transtornos de Estresse por Calor/prevenção & controle , População Rural , Modelos Climáticos , População Urbana , Estações do AnoRESUMO
The Periodic Law of Chemistry is one of the great discoveries in cultural history. Elements behaving chemically similar are empirically merged in groups G of a Periodic Table, each element with G valence electrons per neutral atom, and with upper limit G for the oxidation and valence numbers. Here, we report that among the usually mono- or di-valent s-block elements (G = 1 or 2), the heaviest members (87Fr, 88Ra, 119E, and 120E) with atomic numbers Z = 87, 88, 119, 120 form unusual 5- or 6-valent compounds at ambient conditions. Together with well-reported basic changes of valence at the end of the 6d-series, in the whole 7p-series, and for 5g6f-elements, it indicates that at the bottom of common Periodic Tables, the classic Periodic Law is not as straightforward as commonly expected. Specifically, we predict the feasible experimental synthesis of polyvalent [RaL-n] (n = 4, 6) compounds.
RESUMO
Hybrid voltage indicators (HVIs) are chemogenetic sensors that combines the superior photophysical properties of organic dyes and the genetic targetability of protein sensors to report transient membrane voltage changes. They exhibit boosted sensitivity in excitable cells such as neurons and cardiomyocytes. However, the voltage signals recorded during long-term imaging are severely diminished or distorted due to phototoxicity and photobleaching issues. To capture stable electrophysiological activities over a long time, we employ cyanine dyes conjugated with a cyclooctatetraene (COT) molecule as the fluorescence reporter of HVI. The resulting orange-emitting HVI-COT-Cy3 enables high-fidelity voltage imaging for up to 30 min in cultured primary neurons with a sensitivity of ~ -30% ΔF/F0 per action potential (AP). It also maximally preserves the signal of individual APs in cardiomyocytes. The far-red-emitting HVI-COT-Cy5 allows two-color voltage/calcium imaging with GCaMP6s in neurons and cardiomyocytes for 15 min. We leverage the HVI-COT series with reduced phototoxicity and photobleaching to evaluate the impact of drug candidates on the electrophysiology of excitable cells.
Assuntos
Dermatite Fototóxica , Miócitos Cardíacos , Humanos , Neurônios , Diagnóstico por Imagem , CorantesRESUMO
Fetal development relies on adequate iron supply by the placenta. The placental syncytiotrophoblasts (SCTB) express high levels of iron transporters, including ferroportin1 (Fpn1). Whether they are essential in the placenta has not been tested directly, mainly due to the lack of gene manipulation tools in SCTB. Here, we aimed to generate a SCTB-specific Cre mouse and use it to determine the role of placental Fpn1. Using CRISPR/Cas9 technology, we created a syncytin b (Synb) Cre line (SynbCre) targeting the fetal-facing SCTB layer in mouse placental labyrinth. SynbCre deleted Fpn1 in late gestation mouse placentas reliably with high efficiency. Embryos without placental Fpn1 were pale and runted, and died before birth. Fpn1 null placentas had reduced transferrin receptor expression, increased oxidative stress and detoxification responses, and accumulated ferritin in the SCTB instead of the fetal endothelium. In summary, we demonstrate that SynbCre is an effective and specific tool to investigate placental gene function in vivo. The loss of Fpn1 in late gestation mouse placenta is embryonically lethal, providing direct evidence for an essential role of Fpn1 in placental iron transport.
Assuntos
Proteínas de Transporte de Cátions , Placenta , Feminino , Gravidez , Camundongos , Animais , Ferro , Parto , Proteínas de Transporte de Cátions/genéticaRESUMO
Both neuronal and genetic mechanisms regulate brain function. While there are excellent methods to study neuronal activity in vivo, there are no nondestructive methods to measure global gene expression in living brains. Here, we present a method, epigenetic MRI (eMRI), that overcomes this limitation via direct imaging of DNA methylation, a major gene-expression regulator. eMRI exploits the methionine metabolic pathways for DNA methylation to label genomic DNA through 13C-enriched diets. A 13C magnetic resonance spectroscopic imaging method then maps the spatial distribution of labeled DNA. We validated eMRI using pigs, whose brains have stronger similarity to humans in volume and anatomy than rodents, and confirmed efficient 13C-labeling of brain DNA. We also discovered strong regional differences in global DNA methylation. Just as functional MRI measurements of regional neuronal activity have had a transformational effect on neuroscience, we expect that the eMRI signal, both as a measure of regional epigenetic activity and as a possible surrogate for regional gene expression, will enable many new investigations of human brain function, behavior, and disease.
Assuntos
Encéfalo/metabolismo , Metilação de DNA , Epigênese Genética , Imageamento por Ressonância Magnética/métodos , Animais , Encéfalo/diagnóstico por imagem , Isótopos de Carbono/metabolismo , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Humanos , Metionina/administração & dosagem , Reprodutibilidade dos Testes , SuínosRESUMO
Intracerebral hemorrhage (ICH) is a subtype of stroke marked by elevated mortality and disability rates. Recently, mounting evidence suggests a significant role of ferroptosis in the pathogenesis of ICH. Through a combination of bioinformatics analysis and basic experiments, our goal is to identify the primary cell types and key molecules implicated in ferroptosis post-ICH. This aims to propel the advancement of ferroptosis research, offering potential therapeutic targets for ICH treatment. Our study reveals pronounced ferroptosis in microglia and identifies the target gene, cathepsin B (Ctsb), by analyzing differentially expressed genes following ICH. Ctsb, a cysteine protease primarily located in lysosomes, becomes a focal point in our investigation. Utilizing in vitro and in vivo models, we explore the correlation between Ctsb and ferroptosis in microglia post-ICH. Results demonstrate that ICH and hemin-induced ferroptosis in microglia coincide with elevated levels and activity of Ctsb protein. Effective alleviation of ferroptosis in microglia after ICH is achieved through the inhibition of Ctsb protease activity and protein levels using inhibitors and shRNA. Additionally, a notable increase in m6A methylation levels of Ctsb mRNA post-ICH is observed, suggesting a pivotal role of m6A methylation in regulating Ctsb translation. These research insights deepen our comprehension of the molecular pathways involved in ferroptosis after ICH, underscoring the potential of Ctsb as a promising target for mitigating brain damage resulting from ICH.
Assuntos
Lesões Encefálicas , Catepsina B , Ferroptose , Microglia , Humanos , Lesões Encefálicas/metabolismo , Catepsina B/genética , Catepsina B/metabolismo , Hemorragia Cerebral/patologia , Microglia/metabolismo , Animais , CamundongosRESUMO
OBJECTIVE: The glymphatic system serves as a perivascular pathway that aids in clearing liquid and solute waste from the brain, thereby enhancing neurological function. Disorders in glymphatic drainage contribute to the development of vasogenic edema following cerebral ischemia, although the molecular mechanisms involved remain poorly understood. This study aims to determine whether a deficiency in dystrophin 71 (DP71) leads to aquaporin-4 (AQP4) depolarization, contributing to glymphatic dysfunction in cerebral ischemia and resulting in brain edema. METHODS: A mice model of middle cerebral artery occlusion and reperfusion was used. A fluorescence tracer was injected into the cortex and evaluated glymphatic clearance. To investigate the role of DP71 in maintaining AQP4 polarization, an adeno-associated virus with the astrocyte promoter was used to overexpress Dp71. The expression and distribution of DP71 and AQP4 were analyzed using immunoblotting, immunofluorescence, and co-immunoprecipitation techniques. The behavior ability of mice was evaluated by open field test. Open-access transcriptome sequencing data were used to analyze the functional changes of astrocytes after cerebral ischemia. MG132 was used to inhibit the ubiquitin-proteasome system. The ubiquitination of DP71 was detected by immunoblotting and co-immunoprecipitation. RESULTS: During the vasogenic edema stage following cerebral ischemia, a decline in the efflux of interstitial fluid tracer was observed. DP71 and AQP4 were co-localized and interacted with each other in the perivascular astrocyte endfeet. After cerebral ischemia, there was a notable reduction in DP71 protein expression, accompanied by AQP4 depolarization and proliferation of reactive astrocytes. Increased DP71 expression restored glymphatic drainage and reduced brain edema. AQP4 depolarization, reactive astrocyte proliferation, and the behavior of mice were improved. After cerebral ischemia, DP71 was degraded by ubiquitination, and MG132 inhibited the decrease of DP71 protein level. CONCLUSION: AQP4 depolarization after cerebral ischemia leads to glymphatic clearance disorder and aggravates cerebral edema. DP71 plays a pivotal role in regulating AQP4 polarization and consequently influences glymphatic function. Changes in DP71 expression are associated with the ubiquitin-proteasome system. This study offers a novel perspective on the pathogenesis of brain edema following cerebral ischemia.
Assuntos
Aquaporina 4 , Edema Encefálico , Isquemia Encefálica , Distrofina , Sistema Glinfático , Animais , Aquaporina 4/metabolismo , Aquaporina 4/genética , Camundongos , Sistema Glinfático/metabolismo , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , Edema Encefálico/metabolismo , Distrofina/metabolismo , Distrofina/deficiência , Masculino , Astrócitos/metabolismo , Camundongos Endogâmicos C57BL , Infarto da Artéria Cerebral Média/metabolismoRESUMO
Receptor-like kinases (RLKs) are major regulators of the plant immune response and play important roles in the perception and transmission of immune signals. RECEPTOR LIKE KINASE 902 (RLK902) is at the key node in leucine-rich repeat receptor-like kinase interaction networks and positively regulates resistance to the bacterial pathogen Pseudomonas syringae in Arabidopsis. However, the function of RLK902 in fungal disease resistance remains obscure. In this study, we found that the expression levels of OsRLK902-1 and OsRLK902-2, encoding two orthologues of RLK902 in rice, were induced by Magnaporthe oryzae, chitin, and flg22 treatment. osrlk902-1 and osrlk902-2 knockout mutants displayed enhanced susceptibility to M. oryzae. Interestingly, the osrlk902-1 rlk902-2 double mutant exhibited similar disease susceptibility, hydrogen peroxide production, and callose deposition to the two single mutants. Further investigation showed that OsRLK902-1 interacts with and stabilizes OsRLK902-2. The two OsRLKs form a complex with OsRLCK185, a key regulator in chitin-triggered immunity, and stabilize it. Taken together, our data demonstrate that OsRLK902-1 and OsRLK902-2, as well as OsRLCK185 function together in regulating disease resistance to M. oryzae in rice.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Magnaporthe , Oryza , Resistência à Doença/genética , Complexo Antígeno-Anticorpo/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Arabidopsis/metabolismo , Quitina/metabolismo , Oryza/metabolismo , Doenças das Plantas/microbiologia , Magnaporthe/fisiologia , Proteínas Quinases/metabolismo , Proteínas de Arabidopsis/metabolismoRESUMO
Cerebral ischemia-reperfusion injury in ischemic penumbra is accountable for poor outcome of ischemic stroke patients receiving recanalization therapy. Compelling evidence previously demonstrated a dual role of autophagy in stroke. This study aimed to understand the traits of autophagy in the ischemic penumbra and the potential mechanism that switches the dual role of autophagy. We found that autophagy induction by rapamycin and lithium carbonate performed before ischemia reduced neurological deficits and infarction, while autophagy induction after reperfusion had the opposite effect in the male murine middle cerebral artery occlusion/reperfusion model, both of which were eliminated in mice lacking autophagy (Atg7flox/flox; Nestin-Cre). Autophagic flux determination showed that reperfusion led to a blockage of axonal autophagosome retrograde transport in neurons, which then led to autophagic flux damage. Then, we found that ischemia-reperfusion induced changes in the protein levels of Sec22b and Ykt6 in neurons, two autophagosome transport-related factors, in which Sec22b significantly increased and Ykt6 significantly decreased. In the absence of exogenous autophagy induction, Sec22b knockdown and Ykt6 overexpression significantly alleviated autophagic flux damage, infarction, and neurological deficits in neurons or murine exposed to cerebral ischemia-reperfusion in an autophagy-dependent manner. Furthermore, Sec22b knockdown and Ykt6 overexpression switched the outcome of rapamycin post-treatment from deterioration to neuroprotection. Thus, Sec22b and Ykt6 play key roles in neuronal autophagic flux, and modest regulation of Sec22b and Ykt6 may help to reverse the failure of targeting autophagy induction to improve the prognosis of ischemic stroke.Significance Statement:The highly polarized architecture of neurons with neurites presents challenges for material transport, such as autophagosomes, which form at the neurite tip and need to be transported to the cell soma for degradation. Here, we demonstrate that Sec22b and Ykt6 act as autophagosome porters and play an important role in maintaining the integrity of neuronal autophagic flux. Ischemia-reperfusion-induced excess Sec22b and loss of Ykt6 in neurons lead to axonal autophagosome retrograde trafficking failure, autophagic flux damage, and finally neuronal injury. Facilitated axonal autophagosome retrograde transport by Sec22b knockdown and Ykt6 overexpression may reduce ischemia-reperfusion-induced neuron injury and extend the therapeutic window of pharmacological autophagy induction for neuroprotection.
RESUMO
This study aims to conduct a meta-analysis and dose-response analysis of the relationship between nut intake and cancer risk and mortality. Electronic databases were searched. A meta-analysis was conducted to calculate the pooled effect sizes (ESs) with the corresponding 95% CIs, and a dose-response analysis was performed. A random-effects model was used in the statistical analysis. Two independent reviewers completed the full-text screening, data extraction, and quality assessment. We included 17 articles in the present meta-analysis. Total nuts intake was revealed to be significantly associated with reduced cancer risk (ES: 0.9; 95% CI: 0.86-0.95; P < 0.001) and cancer mortality (ES: 0.88; 95% CI: 0.85-0.92, P < 0.001), especially lung cancer risk (ES: 0.86; 95% CI: 0.81-0.91, P < 0.001) and gastric cancer risk (ES: 0.79; 95% CI: 0.68-0.91, P = 0.001). Moreover, a 10 g/d increment of tree nuts consumption was associated with a 20% cancer mortality reduction (ES: 0.80; 95% CI: 0.71-0.89; P < 0.0001). Nuts intake is significantly associated with the reduction of cancer risk and mortality. Especially, nuts intake is significantly associated with reduced lung cancer risk and gastric cancer risk. Noticeably, a 10 g/d increase in tree nuts intake is related to a 20% reduction in overall cancer mortality.
Assuntos
Neoplasias Pulmonares , Neoplasias Gástricas , Humanos , Nozes , Risco , Neoplasias Pulmonares/epidemiologia , Neoplasias Pulmonares/etiologia , Neoplasias Pulmonares/prevenção & controle , DietaRESUMO
Glucagon-like peptide 1 (GLP-1) elicits a potent reduction in food intake, although the central mechanism mediating this appetite-suppressive effect is not fully understood in all species. To begin to elucidate the molecular mechanisms in quail, we administered GLP-1 via intracerebroventricular (ICV) injection to 7-day-old Japanese quail (Coturnix japonica) and determined effects on food and water intake, behavior, and brain nucleus activation. We observed a reduction in food and water intake, with the lowest effective dose being 0.01 nmol. Quail injected with GLP-1 displayed fewer steps, feeding pecks, exploratory pecks, and jumps, while time spent sitting increased. We quantified c-Fos immunoreactivity at 60 min post-injection in hypothalamic and brainstem nuclei that mediate food intake and determined that the hypothalamic paraventricular nucleus (PVN), and nucleus of the solitary tract and area postrema of the brainstem were activated in response to GLP-1. In conclusion, these results suggest that GLP-1 induces anorexigenic effects that are likely mediated at the level of the PVN and brainstem.
Assuntos
Coturnix , Peptídeo 1 Semelhante ao Glucagon , Animais , Coturnix/metabolismo , Peptídeo 1 Semelhante ao Glucagon/farmacologia , Ingestão de Alimentos , Hipotálamo/metabolismo , Núcleo Hipotalâmico Paraventricular/metabolismo , Proteínas Proto-Oncogênicas c-fos/metabolismo , CodornizRESUMO
Recent studies have confirmed that cardiomyocyte-derived exosomes have many pivotal biological functions, like influencing the progress of coronary artery disease via modulating macrophage phenotypes. However, the mechanisms underlying the crosstalk between cardiomyocytes and macrophages have not been fully characterized. Hence, this study aimed to observe the interaction between cardiomyocytes under hypoxia and macrophages through exosome communication and further evaluate the ability of exosomes derived from cardiomyocytes cultured under hypoxic conditions (Hypo-Exo) to polarize macrophages, and the effect of alternatively activated macrophages (M2) on hypoxic cardiomyocytes. Our results revealed that hypoxia facilitated the production of transforming growth factor-beta (TGF-ß) in H9c2 cell-derived exosomes. Moreover, exosomes derived from cardiomyocytes cultured under normal conditions (Nor-Exo) and Hypo-Exo could induce RAW264.7 cells into classically activated macrophages (M1) and M2 macrophages respectively. Likewise, macrophage activation was induced by circulating exosomes isolated from normal human controls (hNor-Exo) or patients with acute myocardial infarction (hAMI-Exo). Thus, our findings support that the profiles of hAMI-Exo have been changed, which could regulate the polarization of macrophages and subsequently the polarized M2 macrophages reduced the apoptosis of cardiomyocytes in return. Based on our findings, we speculate that exosomes have emerged as important inflammatory response modulators regulating cardiac oxidative stress injury.
Assuntos
Exossomos , Células-Tronco Mesenquimais , MicroRNAs , Exossomos/genética , Humanos , Hipóxia , Macrófagos , MicroRNAs/genética , Miócitos CardíacosRESUMO
Breast cancer (BC) is a prevalent neoplasm that occurs in women all over the world. Growth and differentiation factor 11 (GDF11) plays an essential role in cancer progression. This study focused on investigating the biological role and underlying mechanisms of GDF11 in BC. We detected the expression of GDF11 in 27 patients with BC and BC cell lines. Kaplan-Meier plotter was employed to analyze the relationship between GDF11 expression and overall survival (OS) of BC patients. The proliferative, migratory, invasive, and apoptotic abilities of T47D cells were examined. Correlation analysis of GDF11 with Smad ubiquitination regulatory factor 1 (SMURF1) was conducted. The association between GDF11 and the p53 pathway was analyzed by western blot and PFT-α (a p53 inhibitor)-mediated rescue assays. A brief analysis of the role of estrogen receptor alpha (ERα) signaling in BC progression was performed. The results showed that GDF11 was increased in BC tissues and cell lines, and the high expression of GDF11 was associated with the poor OS of BC patients. GDF11 knockdown inhibited the proliferation, migration, and invasion of T47D cells, but promoted cell apoptosis. Meanwhile, the GDF11 knockdown reduced the SMURF1 expression and invoked the p53 pathway activation. SMURF1 overexpression and PFT-α partially blocked the effects of GDF11 knockdown. In addition, GDF11 knockdown and SMURF1 silencing inhibited the activation of the ERα signaling pathway. In summary, GDF11 was involved in the progression of BC by regulating SMURF1-mediated p53 and ERα pathways, opening up a new way for BC treatment.
Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Ubiquitina-Proteína Ligases/genética , Linhagem Celular Tumoral , Transdução de Sinais , Regulação Neoplásica da Expressão Gênica , Proliferação de Células , Proteínas Morfogenéticas Ósseas/metabolismo , Fatores de Diferenciação de Crescimento/genética , Fatores de Diferenciação de Crescimento/metabolismoRESUMO
The concentration of fine particulate matter (PM2.5) is known to vary spatially across a city landscape. Current networks of regulatory air quality monitoring are too sparse to capture these intra-city variations. In this study, we developed a low-cost (60 USD) portable PM2.5 monitor called Smart-P, for use on bicycles, with the goal of mapping street-level variations in PM2.5 concentration. The Smart-P is compact in size (85 × 85 × 42 mm) and light in weight (147 g). Data communication and geolocation are achieved with the cyclist's smartphone with the help of a user-friendly app. Good agreement was observed between the Smart-P monitors and a regulatory-grade monitor (mean bias error: −3.0 to 1.5 µg m−3 for the four monitors tested) in ambient conditions with relative humidity ranging from 38 to 100%. Monitor performance decreased in humidity > 70% condition. The measurement precision, represented as coefficient of variation, was 6 to 9% in stationary mode and 6% in biking mode across the four tested monitors. Street tests in a city with low background PM2.5 concentrations (8 to 9 µg m−3) and in two cities with high background concentrations (41 to 74 µg m−3) showed that the Smart-P was capable of observing local emission hotspots and that its measurement was not sensitive to bicycle speed. The low-cost and user-friendly nature are two features that make the Smart-P a good choice for empowering citizen scientists to participate in local air quality monitoring.
Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Cidades , Monitoramento Ambiental , Material Particulado/análiseRESUMO
Dual-atom catalysts (DACs) have emerged as efficient electrocatalysts for CO2 reduction owing to the synergistic effect between the binary metal sites. However, rationally modulating the electronic structure of DACs to optimize the catalytic performance remains a great challenge. Herein, we report the electronic structure modulation of three Ni2 DACs (namely, Ni2 -N7 , Ni2 -N5 C2 and Ni2 -N3 C4 ) by the regulation of the coordination environments around the dual-atom Ni2 centres. As a result, Ni2 -N3 C4 exhibits significantly improved electrocatalytic activity for CO2 reduction, not only better than the corresponding single-atom Ni catalyst (Ni-N2 C2 ), but also higher than Ni2 -N7 and Ni2 -N5 C2 DACs. Density functional theory (DFT) calculations revealed that the high electrocatalytic activity of Ni2 -N3 C4 for CO2 reduction could be attributed to the electronic structure modulation to the Ni centre and the resulted proper binding energies to COOH* and CO* intermediates.
RESUMO
Circulating exosomes delivering microRNAs are involved in the occurrence and development of cardiovascular diseases. How are the circulating exosomes involved in the repair of endothelial injury in acute myocardial infarction (AMI) convalescence (3-7 days) was still not clear. In this study, circulating exosomes from AMI patients (AMI-Exo) and healthy controls (Normal-Exo) were extracted. In vitro and in vivo, our study showed that circulating exosomes protected endothelial cells (HUVECs) from oxidative stress damage; meanwhile, Normal-Exo showed better protective effects. Through the application of related inhibitors, we found that circulating exosomes shuttled between HUVECs via dynamin. Microarry analysis and qRT-PCR of circulating exosomes showed higher expression of miR-193a-5p in Normal-Exo. Our study showed that miR-193a-5p was the key factor on protecting endothelial cells in vitro and in vivo. Bioinformatics analyses found that activin A receptor type I (ACVR1) was the potential downstream target of miR-193a-5p, which was confirmed by ACVR1 expression and dual-luciferase report. Inhibitor of ACVR1 showed similar protective effects as miR-193a-5p. While overexpression of ACVR1 could attenuate protective effects of miR-193a-5p. To sum up, these findings suggest that circulating exosomes could shuttle between cells through dynamin and deliver miR-193a-5p to protect endothelial cells from oxidative stress damage via ACVR1.
Assuntos
Células Endoteliais/metabolismo , Exossomos/metabolismo , Técnicas de Transferência de Genes , MicroRNAs/metabolismo , Adulto , Animais , Transporte Biológico , Biópsia , Biologia Computacional , Dinaminas/metabolismo , Exossomos/ultraestrutura , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Células Endoteliais da Veia Umbilical Humana , Humanos , Imuno-Histoquímica , Masculino , Células-Tronco Mesenquimais/metabolismo , MicroRNAs/administração & dosagem , Pessoa de Meia-Idade , Infarto do Miocárdio/etiologia , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/terapia , Estresse Oxidativo , Plasmídeos , Interferência de RNA , RatosRESUMO
The mechanisms underlying thrombocytosis in patients with iron deficiency anemia remain unknown. Here, we present findings that support the hypothesis that low iron biases the commitment of megakaryocytic (Mk)-erythroid progenitors (MEPs) toward the Mk lineage in both human and mouse. In MEPs of transmembrane serine protease 6 knockout (Tmprss6-/-) mice, which exhibit iron deficiency anemia and thrombocytosis, we observed a Mk bias, decreased labile iron, and decreased proliferation relative to wild-type (WT) MEPs. Bone marrow transplantation assays suggest that systemic iron deficiency, rather than a local role for Tmprss6-/- in hematopoietic cells, contributes to the MEP lineage commitment bias observed in Tmprss6-/- mice. Nontransgenic mice with acquired iron deficiency anemia also show thrombocytosis and Mk-biased MEPs. Gene expression analysis reveals that messenger RNAs encoding genes involved in metabolic, vascular endothelial growth factor, and extracellular signal-regulated kinase (ERK) pathways are enriched in Tmprss6-/- vs WT MEPs. Corroborating our findings from the murine models of iron deficiency anemia, primary human MEPs exhibit decreased proliferation and Mk-biased commitment after knockdown of transferrin receptor 2, a putative iron sensor. Signal transduction analyses reveal that both human and murine MEP have lower levels of phospho-ERK1/2 in iron-deficient conditions compared with controls. These data are consistent with a model in which low iron in the marrow environment affects MEP metabolism, attenuates ERK signaling, slows proliferation, and biases MEPs toward Mk lineage commitment.
Assuntos
Anemia Ferropriva/metabolismo , Diferenciação Celular/fisiologia , Células Progenitoras de Megacariócitos/metabolismo , Megacariócitos/metabolismo , Anemia Ferropriva/complicações , Animais , Proliferação de Células , Humanos , Ferro , Células Progenitoras de Megacariócitos/citologia , Megacariócitos/citologia , Camundongos , Camundongos Knockout , Trombocitose/etiologia , Trombocitose/metabolismoRESUMO
BACKGROUND: Maternal iron deficiency (ID) is associated with poor pregnancy and fetal outcomes. The effect is thought to be mediated by the placenta but there is no comprehensive assessment of placental responses to maternal ID. Additionally, whether the influence of maternal ID on the placenta differs by fetal sex is unknown. OBJECTIVES: To identify gene and protein signatures of ID mouse placentas at mid-gestation. A secondary objective was to profile the expression of iron genes in mouse placentas across gestation. METHODS: We used a real-time PCR-based array to determine the mRNA expression of all known iron genes in mouse placentas at embryonic day (E) 12.5, E14.5, E16.5, and E19.5 (n = 3 placentas/time point). To determine the effect of maternal ID, we performed RNA sequencing and proteomics in male and female placentas from ID and iron-adequate mice at E12.5 (n = 8 dams/diet). RESULTS: In female placentas, 6 genes, including transferrin receptor (Tfrc) and solute carrier family 11 member 2, were significantly changed by maternal ID. An additional 154 genes were altered in male ID placentas. A proteomic analysis quantified 7662 proteins in the placenta. Proteins translated from iron-responsive element (IRE)-containing mRNA were altered in abundance; ferritin and ferroportin 1 decreased, while TFRC increased in ID placentas. Less than 4% of the significantly altered genes in ID placentas occurred both at the transcriptional and translational levels. CONCLUSIONS: Our data demonstrate that the impact of maternal ID on placental gene expression in mice is limited in scope and magnitude at mid-gestation. We provide strong evidence for IRE-based transcriptional and translational coordination of iron gene expression in the mouse placenta. Finally, we discover sexually dimorphic effects of maternal ID on placental gene expression, with more genes and pathways altered in male compared with female mouse placentas.
Assuntos
Anemia Ferropriva/metabolismo , Placenta/metabolismo , Complicações na Gravidez/metabolismo , Proteoma/metabolismo , Transcriptoma/fisiologia , Animais , Feminino , Regulação da Expressão Gênica , Ferro/metabolismo , Ferro/farmacologia , Camundongos , Ferroproteínas não Heme/genética , Ferroproteínas não Heme/metabolismo , Gravidez , RNA Mensageiro/genética , RNA Mensageiro/metabolismoRESUMO
Central administration of prostaglandin E2 (PGE2) is associated with potent anorexia in rodents and chicks, although hypothalamic mechanisms are not fully understood. The objective of the present study was to identify hypothalamic nuclei and appetite-related factors that are involved in this anorexigenic effect, using chickens as a model. Intracerebroventricular injection of 2.5, 5, and 10 nmol of PGE2 suppressed food and water intake in broiler chicks in a dose-dependent manner. c-Fos immunoreactivity was increased in the paraventricular nucleus (PVN) at 60 min post injection of 5 nmol of PGE2. Under the same treatment condition, hypothalamic expression of melanocortin receptor 3 and ghrelin mRNAs increased, whereas neuropeptide Y receptor sub-type 5 and tropomyosin receptor kinase B (TrkB) mRNAs decreased in PGE2-treated chicks. In the PVN, chicks injected with PGE2 had more brain-derived neurotrophic factor (BDNF), ghrelin, and c-Fos mRNA but less corticotrophin-releasing factor receptor 1 (CRFR1), CRFR2, and TrkB mRNA expression. In conclusion, PGE2 injection resulted in decreased food and water intake that likely involves BDNF and ghrelin originating in the PVN. Because the anorexigenic effect is so potent and hypothalamic mechanisms are similar in chickens and rodents, a greater understanding of the role of PGE2 in acute appetite regulation may have implications for treating eating and metabolic disorders in humans.
Assuntos
AnorexiaRESUMO
The 24 trioxide halide molecules MO3X of the manganese group (M = Mn-Bh; X = F-Ts), which are iso-valence-electronic with the famous MnO4- ion, have been quantum-chemically investigated by quasi-relativistic density-functional and ab initio correlated approaches. Geometric and electronic structures, valence and oxidation numbers, vibrational and electronic spectral properties, energetic stabilities of the monomers in the gas phase, and the decay mode of MnO3F have been investigated. The light Mn-3d species are most strongly electron-correlated, indicating that the concept of a closed-shell Lewis-type single-configurational structure [Mn+7(d0) O-2(p6)3 F-(p6)] reaches its limits. The concept of real-valued spin orbitals φ(r)·α and φ(r)·ß breaks down for the heavy Bh-6d, At-6p and Ts-7p elements because of the dominating spin-orbit coupling. The vigorous decomposition of MnO3F at ambient conditions starts by the autocatalyzed release of n O2 and the formation of MnmO3m-2nFm clusters, triggered by the electron-depleted "oxylic" character of the oxide ligands in MnO3X.