RESUMO
Subclinical hypothyroidism (SCH) in pregnancy is the most common form of thyroid dysfunction in pregnancy, which can affect fetal nervous system development and increase the risk of neurodevelopmental disorders after birth. However, the mechanism of the effect of maternal subclinical hypothyroidism on fetal brain development and behavioral phenotypes is still unclear and requires further study. In this study, we constructed a mouse model of maternal subclinical hypothyroidism by exposing dams to drinking water containing 50 ppm propylthiouracil (PTU) during pregnancy and found that its offspring were accompanied by severe cognitive deficits by behavioral testing. Mechanistically, gestational SCH resulted in the upregulation of protein expression and activity of HDAC1/2/3 in the hippocampus of the offspring. ChIP analysis revealed that H3K9ac on the neurogranin (Ng) promoter was reduced in the hippocampus of the offspring of SCH, with a significant reduction in Ng protein, leading to reduced expression levels of synaptic plasticity markers PSD95 (a membrane-associated protein in the postsynaptic density) and SYN (synaptophysin, a specific marker for presynaptic terminals), and impaired synaptic plasticity. In addition, administration of MS-275 (an HDAC1/2/3-specific inhibitor) to SCH offspring alleviated impaired synaptic plasticity and cognitive dysfunction in offspring. Thus, our study suggests that maternal subclinical hypothyroidism may mediate offspring cognitive dysfunction through the HDAC1/2/3-H3K9ac-Ng pathway. Our study contributes to the understanding of the signaling mechanisms underlying maternal subclinical hypothyroidism-mediated cognitive impairment in the offspring.
Assuntos
Disfunção Cognitiva , Histona Desacetilase 1 , Histona Desacetilase 2 , Hipotireoidismo , Neurogranina , Efeitos Tardios da Exposição Pré-Natal , Animais , Neurogranina/metabolismo , Neurogranina/genética , Hipotireoidismo/metabolismo , Feminino , Gravidez , Camundongos , Disfunção Cognitiva/metabolismo , Disfunção Cognitiva/etiologia , Histona Desacetilase 2/metabolismo , Histona Desacetilase 2/genética , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Histona Desacetilase 1/metabolismo , Histona Desacetilase 1/genética , Regulação para Baixo , Hipocampo/metabolismo , Masculino , Histona Desacetilases/metabolismo , Histona Desacetilases/genética , Camundongos Endogâmicos C57BL , Plasticidade NeuronalRESUMO
Accumulating research shows that prenatal exposure to maternal stress increases the risk of behavioral and mental health problems for offspring later in life. However, how prenatal stress affects offspring behavior remains unknown. Here, we found that prenatal stress (PNS) leads to reduced Ahi1, decreased synaptic plasticity and cognitive impairment in offspring. Mechanistically, Ahi1 and GR stabilize each other, inhibit GR nuclear translocation, promote Ahi1 and WDR68 binding, and inhibit DYRK1A and WDR68 binding. When Ahi1 deletion or prenatal stress leads to hyperactivity of the HPA axis, it promotes the release of GC, leading to GR nuclear translocation and Ahi1 degradation, which further inhibits the binding of Ahi1 and WDR68, and promotes the binding of DYRK1A and WDR68, leading to elevated DYRK1A, reduced synaptic plasticity, and cognitive impairment. Interestingly, we identified RU486, an antagonist of GR, which increased Ahi1/GR levels and improved cognitive impairment and synaptic plasticity in PNS offspring. Our study contributes to understanding the signaling mechanisms of prenatal stress-mediated cognitive impairment in offspring.
Assuntos
Disfunção Cognitiva , Sistema Hipotálamo-Hipofisário , Feminino , Gravidez , Humanos , Sistema Hipófise-Suprarrenal , Disfunção Cognitiva/etiologia , Plasticidade NeuronalRESUMO
Wireless Body Area Networks (WBANs) can provide real-time and reliable health monitoring, attributing to the human-centered and sensor interoperability properties. WBANs have become a key component of the ubiquitous eHealth (electronic health) revolution that prospers on the basis of information and communication technologies. The prime consideration in WBAN is how to maximize the network lifetime with battery-powered sensor nodes in energy constraint. Novel solutions in Medium Access Control (MAC) protocols are imperative to satisfy the particular BAN scenario and the need of excellent energy efficiency in healthcare applications. In this paper, we propose a hybrid Lifetime Extended Directional Approach (LEDA) MAC protocol based on IEEE 802.15.6 to reduce energy consumption and prolong network lifetime. The LEDA MAC protocol takes full advantages of directional superiority in energy saving that employs multi-beam directional mode in Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) and single-beam directional mode in Time Division Multiple Access (TDMA) for alternative in data reservation and transmission according to the traffic varieties. Moreover, the impacts of some inherent problems of directional antennas such as deafness and hidden terminal problem can be decreased owing to that all nodes generate individual beam according to user priorities designated. Furthermore, LEDA MAC employs a Dynamic Polled Allocation Period (DPAP) for burst data transmissions to increase the network reliability and adaptability. Extensive analysis and simulation results show that the proposed LEDA MAC protocol achieves extended network lifetime with improved performance compared with IEEE 802.15.6.
Assuntos
Redes de Comunicação de Computadores/instrumentação , Tecnologia de Sensoriamento Remoto/instrumentação , Tecnologia sem Fio/instrumentação , Desenho de Equipamento , HumanosRESUMO
Accumulating evidence suggests that prenatal stress (PNS) increases offspring susceptibility to depression, but the underlying mechanisms remain unclear. We constructed a mouse model of prenatal stress by spatially restraining pregnant mice from 09:00-11:00 daily on Days 5-20 of gestation. In this study, western blot analysis, quantitative real-time PCR (qRTâPCR), immunofluorescence, immunoprecipitation, chromatin immunoprecipitation (ChIP), and mifepristone rescue assays were used to investigate alterations in the GR/P300-MKP1 and downstream ERK/CREB/TRKB pathways in the brains of prenatally stressed offspring to determine the pathogenesis of the reduced neurogenesis and depression-like behaviors in offspring induced by PNS. We found that prenatal stress leads to reduced hippocampal neurogenesis and depression-like behavior in offspring. Prenatal stress causes high levels of glucocorticoids to enter the fetus and activate the hypothalamicâpituitaryâadrenal (HPA) axis, resulting in decreased hippocampal glucocorticoid receptor (GR) levels in offspring. Furthermore, the nuclear translocation of GR and P300 (an acetylation modifying enzyme) complex in the hippocampus of PNS offspring increased significantly. This GR/P300 complex upregulates MKP1, which is a negative regulator of the ERK/CREB/TRKB signaling pathway associated with depression. Interestingly, treatment with a GR antagonist (mifepristone, RU486) increased hippocampal GR levels and decreased MKP1 expression, thereby ameliorating abnormal neurogenesis and depression-like behavior in PNS offspring. In conclusion, our study suggested that the regulation of the MKP1 signaling pathway by GR/P300 is involved in depression-like behavior in prenatal stress-exposed offspring and provides new insights and ideas for the fetal hypothesis of mental health.
RESUMO
Gasdermin (GSDM) family proteins were recently identified as the executioner of pyroptosis. The mechanism of pyroptosis mediated by gasdermin D (GSDMD) (a member of GSDM family) in humans and mice is well understood. In pyroptosis, mouse and human GSDMDs are cleaved by activated proinflammatory caspases (caspase-1, 4, 5, or 11) to produce anamino-terminal domain (GSDMD-NT) and a carboxyl-terminal domain (GSDMD-CT). The GSDMD-NT drives cell membrane rupture, which leads to the pyroptotic death of the cells. The expression of porcine GSDMD (pGSDMD) has recently been determined, but the activation and regulation mechanism of pGSDMD and its ability to mediate pyroptosis are largely unknown. In the present study, the activation of porcine caspase-1 (pcaspase-1) and cleavage of pGSDMD occurred in the duodenum and jejunum of a piglet challenged with enterotoxigenic Escherichia coli were first determined. Then the capability of pcaspase-1 to cleave pGSDMD was determined in a cell-free system and in human embryonic kidney cells. The pGSDMD cleavage by pcaspase-1 occurred after the pGSDMD molecule's 276Phenylalanine-Glutamine-Serine-Aspartic acid279 motif. The pGSDMD-NT generated from the pGSDMD cleavage by pcaspase-1 showed the ability to drive cell membrane rupture in eukaryotic cells. When expressed in E. coli competent cells, pGSDMD-NT showed bactericidal activity. These results suggest that pGSDMD is a substate of pcaspase-1 and an executioner of pyroptosis. Our work sheds light on pGSDMD's activation mechanisms and functions.