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Neurons rely heavily on high mitochondrial metabolism to provide sufficient energy for proper development. However, it remains unclear how neurons maintain high oxidative phosphorylation (OXPHOS) during development. Mitophagy plays a pivotal role in maintaining mitochondrial quality and quantity. We herein describe that G protein-coupled receptor 50 (GPR50) is a novel mitophagy receptor, which harbors the LC3-interacting region (LIR) and is required in mitophagy under stress conditions. Although it does not localize in mitochondria under normal culturing conditions, GPR50 is recruited to the depolarized mitochondrial membrane upon mitophagy stress, which marks the mitochondrial portion and recruits the assembling autophagosomes, eventually facilitating the mitochondrial fragments to be engulfed by the autophagosomes. Mutations Δ502-505 and T532A attenuate GPR50-mediated mitophagy by disrupting the binding of GPR50 to LC3 and the mitochondrial recruitment of GPR50. Deficiency of GPR50 causes the accumulation of damaged mitochondria and disrupts OXPHOS, resulting in insufficient ATP production and excessive ROS generation, eventually impairing neuronal development. GPR50-deficient mice exhibit impaired social recognition, which is rescued by prenatal treatment with mitoQ, a mitochondrially antioxidant. The present study identifies GPR50 as a novel mitophagy receptor that is required to maintain mitochondrial OXPHOS in developing neurons.
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Mitocôndrias , Mitofagia , Neurônios , Receptores Acoplados a Proteínas G , Animais , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/genética , Neurônios/metabolismo , Mitocôndrias/metabolismo , Camundongos , Humanos , Fosforilação Oxidativa , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Associadas aos Microtúbulos/genética , Espécies Reativas de Oxigênio/metabolismo , Camundongos Knockout , NeurogêneseRESUMO
Background: Phosphorus in the soil is mostly too insoluble for plants to utilize, resulting in inhibited aboveground biomass, while Carex can maintain their aboveground biomass through the presence of dauciform roots. However, dauciform roots lead to both morphological and physiological changes in the root system, making their primary mechanism unclear. Methods: A greenhouse experiment was conducted on three Carex species, in which Al-P, Ca-P, Fe-P, and K-P were employed as sole phosphorus sources. The plants were harvested and assessed after 30, 60 and 90 days. Results: (1) The density of dauciform roots was positively correlated with root length and specific root length, positively influencing aboveground biomass at all three stages. (2) The aboveground phosphorus concentration showed a negative correlation with both dauciform root density and aboveground biomass in the first two stages, which became positive in the third stage. (3) Aboveground biomass correlated negatively with the aboveground Al concentration, and positively with Ca and Fe concentration (except Al-P). (4) Root morphological traits emerged as critical factors in dauciform roots' promotion of aboveground biomass accumulation. Conclusion: Despite the difference among insoluble phosphorus, dauciform roots have a contributing effect on aboveground growth status over time, mainly by regulating root morphological traits. This study contributes to our understanding of short-term variation in dauciform roots and their regulatory mechanisms that enhance Carex aboveground biomass under low available phosphorus conditions.
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Background and aims: Special root structures that can dissolve insoluble phosphorus locked in soil are supposed to contribute not only to the growing status of themselves but also to the neighbouring plants. However, whether dauciform roots have any effect on the neighbouring plants and how does it respond to meadow degradation had not been studied. Methods: Alpine meadows with different degradation statuses were selected and the functional traits of Carex filispica and the co-occurring species Polygonum viviparum were measured to explore their response to degradation, as well as the response of Polygonum viviparum to the dauciform roots of Carex filispica. Results: The results showed that 1) the number of dauciform roots decreased with the intensifying degradation, positively related to available phosphorus in the soil and negatively related to the aboveground phosphorus of Carex filispica. 2) Carex filispica and Polygonum viviparum are similar in specific leaf area and specific root area, yet different in the phosphorus content. The available phosphorus in the soil was negatively related to the aboveground phosphorus of Carex filispica and positively related to that of Polygonum viviparum. 3) When lightly degraded, the proportion of dauciform roots had positive effects on the aboveground resource-acquiring traits of Polygonum viviparum, which were no longer significant at heavy degradation. 4) Polygonum viviparum and Carex filispica without dauciform roots have similar performance: a decrease of belowground carbon with the increasing degradation, and a trend toward resource conservation with the increasing proportion of dauciform roots, which did not exist in Carex filispica with dauciform roots. Conclusion: Our study found that dauciform roots had a beneficial effect on the resource acquisition of their neighbouring plants. However, due to the uncontrollable nature of natural habitats, whether this effect is stable and strong enough to be performed in ecological restoration requires further lab-controlled studies.
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In the natural habitats of China, dauciform roots were only described in degraded alpine meadows. It was found that the presence of dauciform roots of Carex filispica was related to the advantage of multiple functional traits after trampling, reflecting short-term resistance. However, the long-term response of dauciform roots to trampling and the recovery of C. filispica with and without dauciform roots to trampling require further studies. In this study, different intensities of trampling (0, 50, 200 and 500 passages) were performed in an alpine meadow. One year later, individuals with and without dauciform roots were separated and their functional traits related to the economic spectrum of leaves and roots were measured as a reflection of recovery from trampling. The results showed that: (1) 1 year after trampling, the number of dauciform roots showed an increase with trampling intensity; (2) 1 year later, there was no significant difference in the response of economic spectrum traits among trampling intensities, or between plants with and without dauciform roots; (3) the number of dauciform roots was positively correlated with the leaf area of both individuals with and without dauciform roots, as well as with the biomass of those without dauciform roots; and (4) plants with more resource-conservative roots showed an advantage after trampling recovery: specifically, plants with dauciform roots showed such an advantage in the control group, which was lost with a leaning towards resource-acquisitive roots and an increased density of dauciform roots once trampled. In contrast, plants without dauciform roots showed a significant advantage of conservative roots only after trampling. In conclusion, the presence of dauciform roots is related to the plants' position on the root economic spectrum, thereby influencing the recovery of C. filispica from trampling. Carex filispica showed strong recovery from trampling after 1 year, which makes it an adequate choice for ecological restoration in alpine meadows. Dauciform roots showed a positive correlation with the aboveground growth of both plants with and without them, however, it requires a lab-controlled study to confirm whether there is indeed a positive effect on the growth of neighbouring plants.
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Over recent decades, there has been a severe nitrogen-deposition in alpine meadows which often leads to phosphorus limitation of plant productivity. In these high-altitude localities, Cyperaceae have an increasing biomass while other functional groups decrease. Meanwhile, Cyperaceae are known to have the ability of producing dauciform roots, which are formed under phosphorus limitation, but in China, are only described in these high-altitude places. So, is the superiority of Cyperaceae and the formation of dauciform roots in high-altitude localities related to the accumulation of nitrogen? And is there a link between them? A Carex filispica dominated community in Baima Snow Mountain was selected and quantitative fertilization with four levels of nitrogen and three levels of phosphorus was performed. After 2 weeks, Carex filispica individuals with and without dauciform roots were separated and analyzed for their regular root properties, dauciform root properties, biomass and chemical traits of above- and belowground parts. The total cover of the community declined under phosphorus limitation with increasing nitrogen supply, while the relative cover difference of Carex filispica increased with increasing nitrogen supply and decreased with increasing phosphorus supply. Dauciform roots had a more significant response to nitrogen supply than to phosphorus supply and they were formed the most at a low supply of nitrogen. The biomass and root properties of individuals with dauciform roots were enhanced by nitrogen supply and inhibited by phosphorus supply, while those of individuals without dauciform roots were often enhanced by phosphorus supply. Individuals with and without dauciform roots showed two different mechanisms, and were limited by significantly different factors, which can explain the opposite performance of Cyperaceae after nitrogen and phosphorus supply in previous studies.
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Carex (Planta) , Cyperaceae , Humanos , Pradaria , Nitrogênio , Fósforo , FertilizaçãoRESUMO
Introduction: The drought and phosphorus deficiency have inevitably become environmental issues globally in the future. The analysis of plants functional trait variation and response strategies under the stress of phosphorus deficiency and drought is important to explore their ability to respond to potential ecological stress. Methods: In this study, Carex breviculmis was selected as the research object, and a 14-week pot experiment was conducted in a greenhouse, with two phosphorus treatment (add 0.5mmol/L or 0.05µmol/L phosphorus) and four drought treatment (add 0-5%PEG6000), totaling eight treatments. Biomass allocation characteristics, leaf anatomical characteristics, biochemical parameters, root morphology, chemical element content, and photosynthetic parameters were measured. Results: The results showed that the anatomical characteristics, chemical elements, and photosynthetic parameters of Carex breviculmis responded more significantly to main effect of phosphorus deficiency. Stomatal width, leaf phosphorus content and maximum net photosynthetic rate decreased by 11.38%, 59.39%, 38.18% significantly (p<0.05), while the change in biomass was not significant (p>0.05). Biomass allocation characteristics and root morphology responded more significantly to main effect of drought. Severe drought significantly decreased leaf fresh weight by 61% and increased root shoot ratio by 223.3% compared to the control group (p<0.05). The combined effect of severe drought and phosphorus deficiency produced the highest leaf N/P ratio (291.1% of the control) and MDA concentration (243.6% of the control). Correlation analysis and redundancy analysis showed that the contributions of phosphorus and drought to functional trait variation were similar. Lower epidermal cell thickness was positively correlated with maximum net photosynthetic rate, leaf phosphorus, chlorophyll ab, and leaf fresh weight (p<0.05). Discussion: In terms of response strategy, Carex breviculmis was affected at the microscopic level under phosphorus deficiency stress, but could maintain the aboveground and underground biomass well through a series of mechanisms. When affected by drought, it adopted the strategy of reducing leaf yield and improving root efficiency to maintain life activities. Carex breviculmis could maintain its traits well under low phosphorus and moderate drought, or better conditions. So it may have good ecological service potential in corresponding areas if promoted. This study also provided a reference for plant response to combined drought and phosphorus deficiency stresses.
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In China, dauciform roots were hardly studied and only reported in alpine meadows, where sedges showed a different tendency from other functional groups such as grasses and forbs with degradation. In addition, Carex species were proved to have shifting scaling relationships among LES (leaf economics spectrum) traits under disturbance. So, are these unique performances of sedges related to the presence of dauciform roots, and if so, how? An alpine meadow dominated by Carex filispica in Baima Snow Mountain was selected, and quantitative trampling was performed (0, 50, 200, and 500 passes). The cover and dauciform root properties of Carex filispica were measured, as well as the morphological, chemical traits and biomass of leaves and roots, their correlations and the differences between individuals with and without dauciform roots were analyzed. After the trampling, individuals with dauciform roots showed multiple resource-acquisitive traits: Larger, thicker leaves, more aboveground biomass, higher efficiency of nutrient utilization, and slenderer roots. Additionally, they had a tighter correlation among belowground biomass, morphological and chemical traits, as well as dauciform root properties and morphology of leaves, suggesting that their traits were more related than those without dauciform roots. The presence of dauciform roots in Carex filispica was related to advantages in multiple traits after trampling, which is consistent with and might be responsible for the unique performances of sedges.
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Neoplasias Hepáticas , MicroRNAs , Apoptose/genética , Proliferação de Células/genética , Humanos , Neoplasias Hepáticas/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Via de Sinalização Wnt/genéticaRESUMO
With the rapid growth in demand for high-speed wireless communication, terahertz (THz) has become one of the most promising techniques. Both atmospheric turbulence and pointing errors are important factors in degrading the performance of THz propagation. We study the performance of a multiple-input/multiple-output (MIMO) system in the THz band under the combined influences noted above. Especially, we take the impact on amplitude and phase caused by turbulence into consideration. We adopt the Padé approximation to analyze the probability density function of the channel coefficient in equal gain combining and derive the bit error rate by the Meijer-G function. The curve-fitting results of theoretical analysis are in good agreement with the actual measurements in the THz band. Therefore, it can be deduced that the exponentiated Weibull model can also be applied in the THz band. Then, we verify the theoretical results by Monte Carlo simulation. We find that turbulence is a more significant cause, which deteriorates communication performance in a larger scale of the MIMO system.
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Ubiquitin-conjugating enzyme E2T (UBE2T) functions as an E2 ubiquitin-conjugating enzyme in the ubiquitin-proteasome degradation system and mediates cellular processes, such as cell cycle, proliferation, and differentiation. UBE2T has been considered to be an oncogene in a variety of tumors. However, the oncogenic role of UBE2T in cervical cancer remains unclear. In this study, our results first showed that the expression of UBE2T was higher in both of cervical cancer tissues and cells than that in the normal tissues and cells. Knockdown of UBE2T reduced cervical cancer cell viability and suppressed the proliferation, invasion, and migration. However, overexpression of UBE2T contributed to cervical cancer cell growth and metastasis. Moreover, UBE2T overexpression cervical cancer cells demonstrated enhanced self-renewal capacity with upregulation of SOX2, Oct-4, and Nanog protein. Silencing of UBE2T downregulated protein expression of SOX2, Oct-4, and Nanog in cervical cancer cells reduced self-renewal capacity. Furthermore, ectopic UBE2T expression promoted protein expression of glucose-regulated protein 78 (GRP78) and focal adhesion kinase (FAK) phosphorylation in cervical cancer cells. The knockdown of UBE2T reduced protein expression of GRP78 and FAK phosphorylation. Collectively, UBE2T promoted cervical cancer stem cell traits and exerted an oncogenic role through activation of the GRP78/FAK pathway.
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BACKGROUND: Group B streptococcus (GBS) is the leading cause of early-onset neonatal sepsis. However, GBS was infrequently reported in the developing world in contrast to western countries. This study assessed the prevalence of GBS colonization among pregnant women in Jiangsu, East China, and revealed the difference of GBS infection between culture and PCR. METHODS: A total of 16,184 pregnant women at 34 to 37 weeks' gestation aged 16-47 years were recruited from Nanjing Kingmed Center for Clinical Laboratory. Nine thousand twenty-two pregnant women received GBS screening by PCR detection only. Seven thousand one hundred sixty-two pregnant women received GBS screening by bacterial culture and GBS-positive samples were tested for antibiotic resistance. RESULTS: The overall GBS positive rate was 8.7% by PCR and 3.5% by culture. Colonization rate was highest in the "25-29 years" age group. The 249 GBS-positive samples which detected by culture were all sensitive to penicillin. The prevalence of resistance to erythromycin, clindamycin, and levofloxacin was 77.5, 68.3, and 52.2%, respectively. CONCLUSIONS: This study revealed the data on the prevalence of GBS colonization in pregnant women at 34 to 37 weeks' gestation in Jiangsu, East China. It compared the difference of the sensitivity to detect GBS between PCR and culture. PCR was expected to become a quick method in pregnancy women conventional detection of GBS infection.
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Complicações Infecciosas na Gravidez/epidemiologia , Infecções Estreptocócicas/epidemiologia , Streptococcus agalactiae/isolamento & purificação , Adolescente , Adulto , Antibacterianos/uso terapêutico , China/epidemiologia , Clindamicina/uso terapêutico , Farmacorresistência Bacteriana , Eritromicina/uso terapêutico , Feminino , Humanos , Recém-Nascido , Levofloxacino/uso terapêutico , Pessoa de Meia-Idade , Sepse Neonatal/epidemiologia , Penicilinas/uso terapêutico , Reação em Cadeia da Polimerase , Gravidez , Complicações Infecciosas na Gravidez/diagnóstico , Complicações Infecciosas na Gravidez/tratamento farmacológico , Complicações Infecciosas na Gravidez/microbiologia , Gestantes , Prevalência , Estudos Retrospectivos , Infecções Estreptocócicas/diagnóstico , Infecções Estreptocócicas/tratamento farmacológico , Streptococcus agalactiae/genética , Vagina/microbiologia , Adulto JovemRESUMO
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by memory impairments, which has no effective therapy. Stem cell transplantation shows great potential in the therapy of various disease. However, the application of stem cell therapy in neurological disorders, especially the ones with a long-term disease course such as AD, is limited by the delivery approach due to the presence of the brain blood barrier. So far, the most commonly used delivery approach in the therapy of neurological disorders with stem cells in preclinical and clinical studies are intracranial injection and intrathecal injection, both of which are invasive. In the present study, we use repetitive intranasal delivery of human neural stem cells (hNSCs) to the brains of APP/PS1 transgenic mice to investigate the effect of hNSCs on the pathology of AD. The results indicate that the intranasally transplanted hNSCs survive and exhibit extensive migration and higher neuronal differentiation, with a relatively limited glial differentiation. A proportion of intranasally transplanted hNSCs differentiate to cholinergic neurons, which rescue cholinergic dysfunction in APP/PS1 mice. In addition, intranasal transplantation of hNSCs attenuates ß-amyloid accumulation by upregulating the expression of ß-amyloid degrading enzymes, insulin-degrading enzymes, and neprilysin. Moreover, intranasal transplantation of hNSCs ameliorates other AD-like pathology including neuroinflammation, cholinergic dysfunction, and pericytic and synaptic loss, while enhancing adult hippocampal neurogenesis, eventually rescuing the cognitive deficits of APP/PS1 transgenic mice. Thus, our findings highlight that intranasal transplantation of hNSCs benefits cognition through multiple mechanisms, and exhibit the great potential of intranasal administration of stem cells as a non-invasive therapeutic strategy for AD.
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BACKGROUND: C. striatum is an innocuous inhabitant of the normal human epithelial and mucosal surfaces. The C. striatum ´s thogenic potential is increasingly recognized in our time. METHODS: We present a rare case of CRBSI by C. striatum in a 57-yr-old male patient. The patient suffered from many basic diseases and was admitted to hospital of shock. RESULTS: The patient finally died of septic shock caused by CRBSI due to multidrug-resistant C. striatum which responded neither to empiric nor to targeted treatment. CONCLUSIONS: C. striatum can cause CRBSI in immunocompromised patients when they were treated by intravenous catheters.
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Excitatory (E) and inhibitory (I) balance of neural network activity is essential for normal brain function and of particular importance to memory. Disturbance of E/I balance contributes to various neurological disorders. The appearance of neural hyperexcitability in Alzheimer's disease (AD) is even suggested as one of predictors of accelerated cognitive decline. In this study, we found that GAD67+, Parvalbumin+, Calretinin+, and Neuropeptide Y+ interneurons were progressively lost in the brain of APP/PS1 mice. Transplanted embryonic medial ganglionic eminence derived interneuron progenitors (IPs) survived, migrated, and differentiated into GABAergic interneuron subtypes successfully at 2 months after transplantation. Transplantation of IPs hippocampally rescued impaired synaptic plasticity and cognitive deficits of APP/PS1 transgenic mice, concomitant with a suppression of neural hyperexcitability, whereas transplantation of IPs failed to attenuate amyloid-ß accumulation, neuroinflammation, and synaptic loss of APP/PS1 transgenic mice. These observations indicate that transplantation of IPs improves learning and memory of APP/PS1 transgenic mice via suppressing neural hyperexcitability. This study highlights a causal contribution of GABAergic dysfunction to AD pathogenesis and the potentiality of IP transplantation in AD therapy.
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Doença de Alzheimer/cirurgia , Disfunção Cognitiva/cirurgia , Neurônios GABAérgicos/transplante , Interneurônios/transplante , Células-Tronco Neurais/transplante , Doença de Alzheimer/genética , Doença de Alzheimer/fisiopatologia , Precursor de Proteína beta-Amiloide/genética , Animais , Cognição/fisiologia , Disfunção Cognitiva/fisiopatologia , Modelos Animais de Doenças , Aprendizagem em Labirinto/fisiologia , Camundongos , Camundongos Transgênicos , Presenilina-1/genéticaRESUMO
Variation in resource availability can lead to phenotypic plasticity in the traits comprising the world-wide leaf economics spectrum (LES), potentially impairing plant function and complicating the use of tabulated values for LES traits in ecological studies. We compared 14 Carex (Cyperaceae) species in a factorial experiment (unshaded/shaded × sufficient/insufficient P) to analyze how changes in the network of allometric scaling relationships among LES traits influenced growth under favorable and resource-limited conditions. Changes in leaf mass per area (LMA) shifted the scaling relationships among LES traits expressed per unit area vs mass in ways that helped to sustain growth under resource limitation. Increases in area-normalized photosynthetic capacity and foliar nitrogen (N) were correlated with increased growth, offsetting losses associated with mass-normalized dark respiration and foliar N. These shifts increased the contributions to growth associated with photosynthetic N-use efficiency and the N : P ratio. Plasticity in LMA is at the hub of the functional role of the LES as an integrated and resilient complex system that balances the relationships among area- and mass-based aspects of gas exchange and foliar nutrient traits to sustain at least some degree of plant growth under differing availabilities of above- and below-ground resources.
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Cyperaceae/fisiologia , Nitrogênio/metabolismo , Fotossíntese , Folhas de Planta/fisiologia , Cyperaceae/genética , Cyperaceae/crescimento & desenvolvimento , Cyperaceae/efeitos da radiação , Ecologia , Luz , Tamanho do Órgão , Oxigênio/metabolismo , Fenótipo , Fósforo/metabolismo , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/efeitos da radiaçãoRESUMO
Mitochondria are the double membrane organelles providing most of the energy for cells. In addition, mitochondria also play essential roles in various cellular biological processes such as calcium signaling, apoptosis, ROS generation, cell growth, and cell cycle. Mitochondrial dysfunction is observed in various neurological disorders which harbor acute and chronic neural injury such as neurodegenerative diseases and ischemia, hypoxia-induced brain injury. In this review, we describe how mitochondrial dysfunction contributes to the pathogenesis of neurological disorders which manifest chronic or acute neural injury.
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Mitochondrial dysfunction is an early feature of Alzheimer's disease (AD). Accumulated damaged mitochondria, which are associated with impaired mitophagy, contribute to neurodegeneration in AD. We show levels of Disrupted-in-schizophrenia-1 (DISC1), which is genetically associated with psychiatric disorders and AD, decrease in the brains of AD patients and transgenic model mice and in Aß-treated cultured cells. Disrupted-in-schizophrenia-1 contains a canonical LC3-interacting region (LIR) motif (210 FSFI213 ), through which DISC1 directly binds to LC3-I/II. Overexpression of DISC1 enhances mitophagy through its binding to LC3, whereas knocking-down of DISC1 blocks Aß-induced mitophagy. We further observe overexpression of DISC1, but not its mutant (muFSFI) which abolishes the interaction of DISC1 with LC3, rescues Aß-induced mitochondrial dysfunction, loss of spines, suppressed long-term potentiation (LTP). Overexpression of DISC1 via adeno-associated virus (serotype 8, AAV8) in the hippocampus of 8-month-old APP/PS1 transgenic mice for 4 months rescues cognitive deficits, synaptic loss, and Aß plaque accumulation, in a way dependent on the interaction of DISC1 with LC3. These results indicate that DISC1 is a novel mitophagy receptor, which protects synaptic plasticity from Aß accumulation-induced toxicity through promoting mitophagy.
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Doença de Alzheimer/metabolismo , Doença de Alzheimer/fisiopatologia , Mitofagia , Proteínas do Tecido Nervoso/metabolismo , Plasticidade Neuronal , Doença de Alzheimer/complicações , Motivos de Aminoácidos , Sequência de Aminoácidos , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Autofagossomos/efeitos dos fármacos , Autofagossomos/metabolismo , Autofagossomos/ultraestrutura , Encéfalo/metabolismo , Encéfalo/patologia , Carbonil Cianeto m-Clorofenil Hidrazona/farmacologia , Transtornos Cognitivos/complicações , Transtornos Cognitivos/fisiopatologia , Modelos Animais de Doenças , Regulação para Baixo/efeitos dos fármacos , Células HeLa , Humanos , Masculino , Camundongos Transgênicos , Proteínas Associadas aos Microtúbulos/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/ultraestrutura , Mitofagia/efeitos dos fármacos , Modelos Biológicos , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/genética , Plasticidade Neuronal/efeitos dos fármacos , Ligação Proteica/efeitos dos fármacosRESUMO
Sphingolipids emerge as essential modulators in the etiology of Alzheimer's disease (AD) with unclear mechanisms. Elevated levels of SM synthase 1 (SMS1), which catalyzes the synthesis of SM from ceramide and phosphatidylcholine, have been observed in the brains of Alzheimer's disease (AD), where expression of ß-site APP cleaving enzyme 1 (BACE1), a rate limiting enzyme in amyloid-ß (Aß) generation, are upregulated. In the present study, we show knockdown of SMS1 via andeno associated virus (serotype 8, AAV8) in the hippocampus of APP/PS1 transgenic mice, attenuates the densities of Aß plaques, neuroinflammation, synaptic loss and thus rescuing cognitive deficits of these transgenic mice. We further describe that knockdown or inhibition of SMS1 decreases BACE1 stability, which is accompanied with decreased BACE1 levels in the Golgi, whereas enhanced BACE1 levels in the early endosomes and the lysosomes. The reduction of BACE1 levels induced by knockdown or inhibition of SMS1 is prevented by inhibition of lysosomes. Therefore, knockdown or inhibition of SMS1 promotes lysosomal degradation of BACE1 via modulating the intracellular trafficking of BACE1. Knockdown of SMS1 attenuates AD-like pathology through promoting lysosomal degradation of BACE1.
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Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Precursor de Proteína beta-Amiloide , Ácido Aspártico Endopeptidases/metabolismo , Lisossomos/metabolismo , Presenilina-1 , Transferases (Outros Grupos de Fosfato Substituídos)/metabolismo , Doença de Alzheimer/genética , Secretases da Proteína Precursora do Amiloide/genética , Precursor de Proteína beta-Amiloide/genética , Animais , Ácido Aspártico Endopeptidases/genética , Técnicas de Silenciamento de Genes/métodos , Células HEK293 , Humanos , Lisossomos/genética , Camundongos , Camundongos Transgênicos , Presenilina-1/genética , Transferases (Outros Grupos de Fosfato Substituídos)/antagonistas & inibidores , Transferases (Outros Grupos de Fosfato Substituídos)/genéticaRESUMO
BACKGROUND: According to recent clinical observations, deficient DNA mismatch repair (dMMR) is capable of improving antitumor effects of the PD-1/PD-L1 pathway, suggesting that dMMR may act as a prognostic indicator of PD-1/PD-L1 antibody drugs. In this study, we examined the dMMR and PD-1/PD-L1 expression, as well as explored the correlation of dMMR status with PD-1/PD-L1 expression in cervical cancer patients, in order to optimize cervical cancer patient selection for PD-1/PD-L1 antibody drug treatment, which is helpful to avoid adverse effects and keep costs manageable. METHODS: Sixty-six tissue samples from patients with squamous cell carcinoma were collected, and data of their clinical characteristics were also gathered. Based on these samples, the expression levels of MLH1, MSH2, and PD-L1 in cancer cells were tested by immunohistochemical assay (IHC). Moreover, PD-1/PD-L1 expression in tumor-invading lymphocytes (TILs) was detected by IHC as well. Six single-nucleotide-repeat markers of microsatellite instability (MSI), including NR-27, MONO-27, BAT-25, NR-24, NR-21, and BAT-26, were tested by capillary electrophoresis sequencer analysis. According to expression of MLH1, MSH2 and the MSI test, all 66 cases were divided into dMMR or proficient DNA mismatch repair (pMMR) groups. The comparisons of dMMR and PD-L1 in cancer cells and of PD-1/PD-L1 in TILs were conducted categorized by age, childbearing history, history of abortion, ethnicity, and cancer cell differentiation subgroup. Furthermore, PD-L1 levels in cancer cells and PD-1/PD-L1 in TILs were analyzed and compared in both dMMR and pMMR subgroups. RESULTS: Of the patient samples, 25.8% were associated with dMMR. PD-L1 in cancer cells, PD-L1 in TILs, and PD-1 in TILs took up 59.1%, 47.0%, and 60.6%, respectively. The data indicated that both dMMR and PD-L1 overexpression resulted from lower cancer differentiation, more incidences of childbearing, and a history of abortion. Abortion could significantly increase PD-1 expression levels in TILs. Additionally, more incidence of childbearing or older age (35-55 years) was able to upregulate PD-L1 expression in TILs. Statistical difference of PD-L1 in cancer cells could be observed between dMMR and pMMR subgroups. In the dMMR group, PD-L1 in cancer cells and PD-1 in TILs had no correlation (rs=0.161, p=0.537), but in the pMMR group, they had good correlation (rs=0.645, p<0.001). CONCLUSION: According to prior studies and our own experiments, PD-L1 in both cancer cells and TILs and PD-1 in TILs are widely observed in cervical cancer patients, indicating that there may be potential to apply PD-1/PD-L1 antibody drugs in cervical cancer. dMMR patients are associated with higher PD-L1 expression compared with pMMR ones, which suggested that PD-1/PD-L1 antibody drugs may work well in dMMR cervical cancer patients. Moreover, in patients with more incidences of childbearing or abortion, dMMR may be a molecular detection target for clinical application of PD-1/PD-L1 antibody drugs.
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Malignant hyperthermia (MH) is a rare life threatening inherited disorder that is triggered by drugs used for general anesthesia in susceptible persons. The symptoms include rapid increase of body temperature and severe muscle contractions. The present study includes 3 cases of MH and highlights the timely identification of symptoms for rescuing the patient. In case I, a 7-year-old male child underwent surgery with ketamine at a dose of 250 mg. After 4 h of operation, the child went through convulsions, high fever and succumbed within a few hours. High fever was not detected in a timely manner, which is one of the main symptoms of MH. In case II, a 12-year-old male child had convulsions and high fever after simple surgery caused by MH. Once confirmed, immediate measures were taken to lower the body temperature and the child was rescued. In case III, a male 57-year-old was admitted to hospital due to paraplegia. The patient underwent more critical conditions once symptoms of MH appeared. Additionally, antidote dantrolene was unavailable in the first and third case; thus, the progression of disease was not alleviated although active symptomatic and supportive treatment were employed.