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Understanding how life history shapes genetic diversity is a fundamental issue in evolutionary biology, with important consequences for conservation. However, we still have an incomplete picture of the impact of life history on genome-wide patterns of diversity, especially in long-lived semelparous plants. Puya raimondii is a high-altitude semelparous species from the Andes that flowers at 40-100 years of age. We sequenced the whole genome and estimated the nucleotide diversity of 200 individuals sampled from nine populations. Coalescent-based approaches were then used to infer past population dynamics. Finally, these results were compared with results obtained for the iteroparous species, Puya macrura. The nine populations of P. raimondii were highly divergent, highly inbred, and carried an exceptionally high genetic load. They are genetically depauperate, although, locally in the genome, balancing selection contributed to the maintenance of genetic polymorphism. While both P. raimondii and P. macrura went through a severe bottleneck during the Pleistocene, P. raimondii did not recover from it and continuously declined, while P. macrura managed to bounce back. Our results demonstrate the importance of life history, in particular generation time and reproductive strategy, in affecting population dynamics and genomic variation, and illustrate the genetic fragility of long-lived semelparous plants.
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Background: The relationship between plaque psoriasis and both MASLD and lean MASLD has not been sufficiently explored in the current literature. Method: This retrospective and observational study was carried out from January 2021 to January 2023 at The First Affiliated Hospital of Zhejiang Chinese Medical University. Patients diagnosed with plaque psoriasis and a control group consisting of individuals undergoing routine physical examinations were enrolled. The incidence of MASLD and lean MASLD among these groups was compared. Additionally, patients with plaque psoriasis were divided into those with MASLD, those with lean MASLD, and a control group with only psoriasis for a serological comparative analysis. Results: The incidence of MASLD in the observation group and the control group was 43.67% (69/158) and 22.15% (35/158), respectively (p < 0.01). Furthermore, the incidence of lean MASLD within the observation group and the control group was 10.76% (17/158) and 4.43% (7/158), respectively (p < 0.01). After controlling for potential confounding variables, plaque psoriasis was identified as an independent risk factor for MASLD with an odds ratio of 1.88 (95% cl: 1.10-3.21). In terms of serological comparison, compared to the simple psoriasis group, we observed a significant elevation in the tumor marker CYFRA21-1 levels in both groups compared to the control group with simple psoriasis (p < 0.01). Moreover, the MASLD group exhibited elevated levels of inflammatory markers and psoriasis score, whereas these effects were mitigated in the lean MASLD group. Conclusion: The prevalence of MASLD and lean MASLD is higher among patients with psoriasis. Those suffering from psoriasis along with MASLD show increased psoriasis scores and inflammatory markers compared to those without metabolic disorders. MASLD likely worsens psoriasis conditions, indicating the necessity of targeted health education for affected individuals to reduce the risk of MASLD, this education should include guidelines on exercise and diet. In serological assessments, elevated levels of cytokeratin 19 fragment (CYFRA21-1) were noted in both MASLD and lean MASLD groups, implying a potential synergistic role between psoriasis and MASLD.
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OBJECTIVES: This study aimed to explore the protective mechanism of chitosan oligosaccharide (COS) against lipopolysaccharide (LPS)-induced inflammatory responses in IEC-6 cells and dextran sodium sulfate (DSS)-induced colitis in mice. METHODS: The cell inflammation model was constructed by LPS in vitro and enteritis model by DSS in vivo. RESULTS: Following LPS exposure, IEC-6 cell proliferation significantly decreased, epithelial cell integrity was compromised, and TNF-α and IL-1ß levels were increased. However, COS pretreatment reversed these changes. In vivo, DSS-treated mice exhibited evident pathological alterations, including heightened inflammatory levels and significantly decreased expression of tight junction proteins and critical proteins in the Mitogen activated proteins kinase signaling pathway. Nevertheless, COS administration notably reduced inflammatory levels and increased the expression of tight junction proteins and key proteins in the Mitogen activated proteins kinase signaling pathway. CONCLUSIONS: Our findings suggest that COS safeguards gut barrier integrity by upregulating tight junction proteins through the ERK1/2 signaling pathway. Therefore, COS has emerged as a promising candidate for novel drug interventions against inflammatory bowel disease.
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Quitosana , Colite , Sulfato de Dextrana , Lipopolissacarídeos , Sistema de Sinalização das MAP Quinases , Oligossacarídeos , Proteínas de Junções Íntimas , Regulação para Cima , Animais , Quitosana/farmacologia , Proteínas de Junções Íntimas/metabolismo , Oligossacarídeos/farmacologia , Colite/induzido quimicamente , Colite/metabolismo , Colite/tratamento farmacológico , Camundongos , Regulação para Cima/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Modelos Animais de Doenças , Linhagem Celular , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Camundongos Endogâmicos C57BL , RatosRESUMO
BACKGROUND: Episodic memory loss is a prominent clinical manifestation of Alzheimer's disease (AD), which is closely related to tau pathology and hippocampal impairment. Due to the heterogeneity of brain neurons, the specific roles of different brain neurons in terms of their sensitivity to tau accumulation and their contribution to AD-like social memory loss remain unclear. Therefore, further investigation is necessary. METHODS: We investigated the effects of AD-like tau pathology by Tandem mass tag proteomic and phosphoproteomic analysis, social behavioural tests, hippocampal electrophysiology, immunofluorescence staining and in vivo optical fibre recording of GCaMP6f and iGABASnFR. Additionally, we utilized optogenetics and administered ursolic acid (UA) via oral gavage to examine the effects of these agents on social memory in mice. RESULTS: The results of proteomic and phosphoproteomic analyses revealed the characteristics of ventral hippocampal CA1 (vCA1) under both physiological conditions and AD-like tau pathology. As tau progressively accumulated, vCA1, especially its excitatory and parvalbumin (PV) neurons, were fully filled with mislocated and phosphorylated tau (p-Tau). This finding was not observed for dorsal hippocampal CA1 (dCA1). The overexpression of human tau (hTau) in excitatory and PV neurons mimicked AD-like tau accumulation, significantly inhibited neuronal excitability and suppressed distinct discrimination-associated firings of these neurons within vCA1. Photoactivating excitatory and PV neurons in vCA1 at specific rhythms and time windows efficiently ameliorated tau-impaired social memory. Notably, 1 month of UA administration efficiently decreased tau accumulation via autophagy in a transcription factor EB (TFEB)-dependent manner and restored the vCA1 microcircuit to ameliorate tau-impaired social memory. CONCLUSION: This study elucidated distinct protein and phosphoprotein networks between dCA1 and vCA1 and highlighted the susceptibility of the vCA1 microcircuit to AD-like tau accumulation. Notably, our novel findings regarding the efficacy of UA in reducing tau load and targeting the vCA1 microcircuit may provide a promising strategy for treating AD in the future.
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Doença de Alzheimer , Humanos , Masculino , Camundongos , Animais , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Camundongos Transgênicos , Proteômica , Hipocampo/metabolismo , Hipocampo/patologia , Transtornos da Memória/metabolismoRESUMO
Exposure to vomitoxin (DON) can negatively impact the intestinal health of livestock and poultry, leading to compromised nutrient absorption and utilization, resulting in slowed growth and reduced production efficiency. In this study, we synthesized carbonated chitosan montmorillonite intercalation complexes (CCM) through solution precipitation. The successful formation of intercalation complexes was confirmed by examining functional groups and surface features using infrared spectroscopy and scanning electron microscopy. To assess the impact of CCM on DON-infected mice, we established an experimental mouse model of jejunal inflammation induced by DON infection. We analyzed the effects of CCM on blood biochemical and conventional indices, jejunal inflammatory factors, pathological changes, and the expression of proteins in the MAPK pathways in DON-infected mice. Our results indicate that CCM effectively mitigates the adverse effects of DON on growth performance, jejunal injury, and the inflammatory response in mice. CCM supplementation alleviated the negative effects of DON infection on growth performance and reduced intestinal inflammation in mice. Moreover, CCM supplementation successfully inhibited the activation of the mitogen-activated protein kinase (MAPK) signaling pathway induced by DON. These findings suggest that the mitigating effect of CCM on DON-induced inflammatory injury in the murine jejunum is closely linked to the regulation of the MAPK signaling pathway.
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Although numerous studies have shown that the hypothalamic-pituitary-adrenal axis plays a vital role in the response to environmental stress by mediating the production of a series of hormones, the mechanism underlying these effects has not been elucidated. This study used proteomics techniques to investigate the differentially expressed proteins (DEPs) in the pituitary glands of pigs and to elucidate the potential changes in the immune-neuroendocrine system under heat stress (HS). In total, 2517 peptides corresponding to 205 proteins were detected. A comparison of the expression patterns between HSs and healthy controls revealed 56 DEPs, of which 31 were upregulated and 25 were downregulated. Ingenuity pathway analysis (IPA) was used to reveal the subcellular characteristics, functional pathways, regulatory networks, and upstream regulators of the identified proteins. The results showed that these differentially expressed proteins were involved in intercellular communication, interactions, apoptosis, nervous system development, functions, abnormalities and other functions, and in the regulatory network. Moreover, the upstream regulators of the differentially expressed proteins were mainly transcriptional regulators, hormones, and cytokines. Thus, the functional network and pathway analyses could provide insights into the complexity and dynamics of HS-host interactions and may accelerate our understanding of the mechanisms underlying HS.
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The subject of this study was to explore the optimum requirements of loach (Paramisgurnus dabryanus) regarding dietary proteins and lipids and discuss the underlying mechanism. We designed nine diets to determine the effects of different levels of dietary crude protein (CP: 30%, 35%, and 40%) and ether extract (EE: 6%, 10%, and 14%) on the growth performance and metabolism of P. dabryanus. In total, 2160 healthy P. dabryanus (5.19 ± 0.01 g) were divided into nine groups with four replications at 60 fish per barrel stocking density. The trial lasted for eight weeks. Serum and liver samples were gathered for metabolomic and transcriptomic analyses. The results showed that the specific growth rate of P. dabryanus in the CP40EE10 group was the fastest and notably higher than that in other groups (P< 0.05). Analysis of the metabolome results found that the mTOR signaling pathway, glycerophospholipid metabolism, D-arginine and D-ornithine metabolism were significantly enriched pathways in the CP40EE10 group compared with the other groups (P< 0.05). Moreover, the transcriptomic analysis of differentially expressed genes (DEGs) showed that the expression of ARG (arginase) involved in protein synthesis was significantly upregulated in the CP40EE10 group compared to the slowest growing group (P< 0.05). Additionally, the expression of SPLA2 (secretory phospholipase A2) involved in lipid metabolism and FBP (fructose-1,6-bisphosphatase) involved in glucose metabolism were all significantly downregulated in the CP30EE6 group compared with the CP40EE10 group (P< 0.05). Furthermore, the analysis of differentially expressed metabolites (DEMs) and DEGs co-enriched in the KEGG pathway revealed that the significantly enriched pathways were arginine and proline metabolism, glycerophospholipid metabolism, and glycolysis/gluconeogenesis in CP40EE10 compared with other groups (P< 0.05). We conclude that including 40% CP and 10% EE in the P. dabryanus diet could result in a better growth rate. We hypothesized from metabolomic and transcriptomic analyses that the CP40EE10 diet might promote the growth of P. dabryanus by promoting protein synthesis, lipid metabolism, and energy production.
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Cipriniformes , Transcriptoma , Animais , Cipriniformes/genética , Arginina , Proteínas Alimentares , Glicerofosfolipídeos , LipídeosRESUMO
Polymethyl methacrylate (PMMA) bone cement (PBC) is commonly used in orthopaedic surgery. However, polymerization volumetric shrinkage, exothermic injury, and low bioactivity prevent PBC from being an ideal material. The developed expandable P(MMA-AA-St) well overcomes the volumetric shrinkage of PBC. However, its biomechanical properties are unsatisfactory. Herein, graphene oxide (GO), a hydrophilic material with favourable biomechanics and osteogenic capability, was added to P(MMA-AA-St) to optimize its biomechanics and bioactivity. The GO-modified self-expandable P(MMA-AA-St)-GO nanocomposite (PGBCs) exhibited outstanding compressive strength (>70 âMPa), water absorption, and volume expansion, as well as a longer handling time and a reduced setting temperature. The cytocompatibility of PGBCs was superior to that of PBC, as demonstrated by CCK-8 assay, live-dead cell staining, and flow cytometry. In addition, better osteoblast attachment was observed, which could be attributed to the effects of GO. The improved level of osteogenic gene and protein expression further illustrated the improved cell-material interactions between osteoblasts and PGBCs. The results of an in vivo study performed by filling bone defects in the femoral condyles of rabbits with PGBCs demonstrated promising intraoperative handling properties and convenient implantation. Blood testing and histological staining demonstrated satisfactory in vivo biosafety. Furthermore, bone morphological and microarchitecture analyses using bone tissue staining and micro-CT scanning revealed better bone-PGBCs contact and osteogenic capability. The results of this study indicate that GO modification improved the physiochemical properties, cytocompatibility, and osteogenic capability of P(MMA-AA-St) and overcame the drawbacks of PBC, allowing its material derivatives to serve as effective implantable biomaterials.
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A simple food chain (plant, insect pests, and predatory arthropods) in an agro-ecosystem was set up here as a model system to elucidate the potential effect of transgenic Bacillus thuringiensis (Bt) cotton on non-target organisms. The system included transgenic/non-transgenic cotton, neonate larvae of three herbivorous insects (Spodoptera exigua, Helicoverpa armigera, and S. litura), and predatory lacewing larvae (Chrysopa spp.), which represent the first, second, and third trophic levels, respectively. The results showed that transgenic treatments and different densities of prey had significant effects on both body-weight gain of neonate herbivorous larvae and the number of prey captured by lacewing larvae, respectively. It was found that Bt toxin could persist at the third trophic level in lacewing larvae. The diet mixture bioassay showed that body-weight gain of lacewing larvae was significantly affected by various treatments, especially at lower concentrations of plant-expressed Bt toxin in the diet mixture, which caused significant decreases in body-weight gain. In contrast, synthetic Bt toxin at higher concentrations in the diet did not show this effect. Thus, we inferred that Bt toxin indirectly affected the growth of the lacewings and the lacewings may not be susceptible to Bt toxin or are able to metabolize it.
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BACKGROUND: Human Tau (hTau) accumulation and synapse loss are two pathological hallmarks of tauopathies. However, whether and how hTau exerts toxic effects on synapses remain elusive. METHODS: Mutated hTau (P301S) was overexpressed in the N2a cell line, primary hippocampal neurons and hippocampal CA3. Western blotting and quantitative polymerase chain reaction were applied to examine the protein and mRNA levels of synaptic proteins. The protein interaction was tested by co-immunoprecipitation and proximity ligation assays. Memory and emotion status were evaluated by a series of behavioural tests. The transcriptional activity of nuclear factor-erythroid 2-related factor 2 (NRF2) was detected by dual luciferase reporter assay. Electrophoresis mobility shift assay and chromosome immunoprecipitation were conducted to examine the combination of NRF2 to specific anti-oxidative response element (ARE) sequences. Neuronal morphology was analysed after Golgi staining. RESULTS: Overexpressing P301S decreased the protein levels of post-synaptic density protein 93 (PSD93), PSD95 and synapsin 1 (SYN1). Simultaneously, NRF2 was decreased, whereas Kelch-like ECH-associated protein 1 (KEAP1) was elevated. Further, we found that NRF2 could bind to the specific AREs of DLG2, DLG4 and SYN1 genes, which encode PSD93, PSD95 and SYN1, respectively, to promote their expression. Overexpressing NRF2 ameliorated P301S-reduced synaptic proteins and synapse. By means of acetylation at K312, P301S increased the protein level of KEAP1 via inhibiting KEAP1 degradation from ubiquitin-proteasome pathway, thereby decreasing NRF2 and reducing synapse. Blocking the P301S-KEAP1 interaction at K312 rescued the P301S-suppressed expression of synaptic proteins and memory deficits with anxiety efficiently. CONCLUSIONS: P301S-hTau could acetylate KEAP1 to trigger synaptic toxicity via inhibiting the NRF2/ARE pathway. These findings provide a novel and potential target for the therapeutic intervention of tauopathies.
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Fator 2 Relacionado a NF-E2 , Tauopatias , Hidrolases de Éster Carboxílico/metabolismo , Genes Reguladores , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch/genética , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Elementos de Resposta , Tauopatias/genéticaRESUMO
Sonerileae is a diverse Melastomataceae lineage comprising ca. 1000 species in 44 genera, with >70% of genera and species distributed in Asia. Asian Sonerileae are taxonomically intractable with obscure generic circumscriptions. The backbone phylogeny of this group remains poorly resolved, possibly due to complexity caused by rapid species radiation in early and middle Miocene, which hampers further systematic study. Here, we used genome resequencing data to reconstruct the phylogeny of Asian Sonerileae. Three parallel datasets, viz. single-copy ortholog (SCO), genomic SNPs, and whole plastome, were assembled from genome resequencing data of 205 species for this purpose. Based on these genome-scale data, we provided the first well resolved phylogeny of Asian Sonerileae, with 34 major clades identified and 74% of the interclade relationships consistently resolved by both SCO and genomic data. Meanwhile, widespread phylogenetic discordance was detected among SCO gene trees as well as species trees reconstructed using different tree estimation methods (concatenation/site-based coalescent method/summary method) or different datasets (SCO/genomic/plastome). We explored sources of discordance using multiple approaches and found that the observed discordance in Asian Sonerileae was mainly caused by a combination of biased distribution of missing data, random noise from uninformative genes, incomplete lineage sorting, and hybridization/introgression. Exploration of these sources can enable us to generate hypotheses for future testing, which is the first step towards understanding the evolution of Asian Sonerileae. We also detected high levels of homoplasy for some characters traditionally used in taxonomy, which explains current chaotic generic delimitations. The backbone phylogeny of Asian Sonerileae revealed in this study offers a solid basis for future taxonomic revision at the generic level.
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Melastomataceae , Genômica/métodos , Hibridização Genética , Filogenia , Análise de Sequência de DNARESUMO
BACKGROUND: Autophagy dysfunction plays a crucial role in tau accumulation and neurodegeneration in Alzheimer's disease (AD). This study aimed to investigate whether and how the accumulating tau may in turn affect autophagy. METHODS: The primary hippocampal neurons, N2a and HEK293T cells with tau overexpression were respectively starved and treated with vinblastine to study the effects of tau on the initiating steps of autophagy, which was analysed by Student's two-tailed t-test. The rapamycin and concanamycin A were employed to inhibit the mammalian target of rapamycin kinase complex 1 (mTORC1) activity and the vacuolar H+-ATPase (v-ATPase) activity, respectively, which were analysed by One-way ANOVA with post hoc tests. The Western blotting, co-immunoprecipitation and immunofluorescence staining were conducted to gain insight into the mechanisms underlying the tau effects of mTORC1 signaling alterations, as analysed by Student's two-tailed t-test or One-way ANOVA with post hoc tests. The autophagosome formation was detected by immunofluorescence staining and transmission electron microscopy. The amino acids (AA) levels were detected by high performance liquid chromatography (HPLC). RESULTS: We observed that overexpressing human full-length wild-type tau to mimic AD-like tau accumulation induced autophagy deficits. Further studies revealed that the increased tau could bind to the prion-related domain of T cell intracellular antigen 1 (PRD-TIA1) and this association significantly increased the intercellular level of amino acids (Leucine, P = 0.0038; Glutamic acid, P = 0.0348; Alanine, P = 0.0037; Glycine, P = 0.0104), with concordant upregulation of mTORC1 activity [phosphorylated eukaryotic translation initiation factor 4E-binding protein 1 (p-4EBP1), P < 0.0001; phosphorylated 70 kDa ribosomal protein S6 kinase 1 (p-p70S6K1), P = 0.0001, phosphorylated unc-51-like autophagy-activating kinase 1 (p-ULK1), P = 0.0015] and inhibition of autophagosome formation [microtubule-associated protein light chain 3 II (LC3 II), P = 0.0073; LC3 puncta, P < 0.0001]. As expected, this tau-induced deficit of autophagosome formation in turn aggravated tau accumulation. Importantly, we also found that blocking TIA1 and tau interaction by overexpressing PRD-TIA1, downregulating the endogenous TIA1 expression by shRNA, or downregulating tau protein level by a small proteolysis targeting chimera (PROTAC) could remarkably attenuate tau-induced autophagy impairment. CONCLUSIONS: Our findings reveal that AD-like tau accumulation inhibits autophagosome formation and induces autophagy deficits by activating the TIA1/amino acid/mTORC1 pathway, and thus this work reveals new insight into tau-associated neurodegeneration and provides evidence supporting the use of new therapeutic targets for AD treatment and that of related tauopathies.
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Autofagossomos , Alvo Mecanístico do Complexo 1 de Rapamicina , Antígeno-1 Intracelular de Células T , Proteínas tau , Aminoácidos/metabolismo , Autofagossomos/metabolismo , Células HEK293 , Humanos , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Antígeno-1 Intracelular de Células T/metabolismo , Proteínas tau/metabolismo , Proteínas tau/farmacologiaRESUMO
The study of short-term dynamics of soil moisture in the dry-hot valley area during rainfall process will help identify soil hydrological function. In this study, we analyzed the short-term responses of soil moisture to rainfall in Huajiang dry-hot valley of Guizhou, using in-situ monitoring method to yield high-frequency soil moisture monitoring data of different slope positions. The results showed that, during the whole monitoring period, soil moisture at each layer was at a moderate variation level (15.2%≤coefficient of variation CV≤29.7%), for both upper slope and middle slope. The fluctuation range of soil moisture of the upper slope (CV=21.1%) was greater than that of the middle slope (CV=19.1%), and that of the 0-5 cm soil layer (CV=26.2%) was greater than 20-40 cm layer (CV=16.5%). Compared with the middle slope, soil moisture of the upper slope had a faster response to rainfall. The supplement amount of rainfall was bigger and the supplement speed of rainfall was faster at the upper slope than that at the middle slope. The difference between the supplement speed and the depletion speed of soil moisture of the upper slope (2.3%·h-1) was greater than that of the middle slope (1.8%·h-1). With the increase of soil depth, the responses of soil moisture to rainfall in subsoil layer was earlier or synchronous with that in topsoil layer. When the supplement amount of soil moisture decreased and the supplement speed slowed down, the depletion speed slowed down. Compared with the middle slope, soil at the upper slope had greater water infiltration capacity and better water retention capacity. The responses of soil moisture to rainfall in dry-hot valley were influenced by micro-environment and microclimate, and the rapid recharge of dominant flow at rock-soil interface accelerated the response speed of subsoil moisture to rainfall, which made the slopes in this area easier to form mixed runoff generation mechanism.
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Chuva , Solo , China , Hidrologia , Água , Movimentos da ÁguaRESUMO
Here, the high fluorescent silicon-doped carbon quantum dots (Si-CQDs) were prepared by a facile and one-pot hydrothermal assay using 3-aminopropyltrimethoxysilane as the carbon and silicon source. The prepared Si-CQDs exhibit favorable water-soluble, high-temperature resistance, acid resistance, alkali resistance, high ionic strength resistance, high photostability, film-forming ability and solid-state fluorescence. Compared to other Si-CQDs that have been reported, the prepared Si-CQDs show unique up-conversion fluorescence. Furthermore, it is found that berberine hydrochloride (BH) can effectively quench the down- and up-conversion fluorescence of the Si-CQDs, making it can be used as a highly sensitive and specific probe for BH dual-mode sensing. Meanwhile, the linear range of down-conversion fluorescence detection for BH is 0.5-30.0 µmol/L with a limit of detection (LOD) of 50 nmol/L, and the linear range of up-conversion fluorescence assay for BH is 0-25.0 µmol/L. The mechanism of down-conversion fluorescence quenching by BH was investigated through a series of studies. The results show the quenching mechanism is the inner filter effect (IFE). Moreover, this proposed strategy has been well used to analyze BH in urine samples with satisfactory results.
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Berberina , Pontos Quânticos , Carbono , Corantes Fluorescentes , Nitrogênio , SilícioRESUMO
BACKGROUND: Recent studies show that an increased T217-phosphorylation of tau in plasma could diagnose AD at an early stage with high accuracy and high specificity, while the potential toxic role of tau T217-phosphorylation is not known. OBJECTIVE: To study the potential toxic role of tau T217-phosphorylation. METHODS: We performed stereotactic brain injection, behavioral testing, immunohistochemistry and immunofluorescence, western blotting, Golgi staining, in vitro recombinant tau polymerization, and other measurements. RESULTS: We first constructed tau T217-wild-type (T217), T217-phospho-mimic (T217E), and T217-non-phospho-mimic (T217A) plasmids or their virus vectors on the basis of wild-type tau. We found that expressing tau-T217E induced a significantly increased tau phosphorylation at multiple AD-associated sites with inhibited proteolysis and increased cleavage/fibrillization of tau, while expressing tau-T217A abolished the above changes of tau both in vitro and in vivo. By mutating T217E on tau-P301L, a dominant mutation identified in patients with frontotemporal dementia, we did not observe significant exacerbation of tau-P301L phosphorylation and cognitive impairment although the increased tau cleavage and propagation were shown. CONCLUSION: T217-phosphorylation exacerbates wild-type tau hyperphosphorylation with aggravated tau cleavage/fibrillization and cognitive impairments, while overexpressing T217E on the basis P301L does not exacerbate tau phosphorylation or the P301L-induced cognitive deficits, although it aggravates tau cleavage and propagation.
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Cognição/fisiologia , Disfunção Cognitiva/metabolismo , Hipocampo/metabolismo , Aprendizagem em Labirinto/fisiologia , Tauopatias/metabolismo , Proteínas tau/metabolismo , Animais , Disfunção Cognitiva/patologia , Hipocampo/patologia , Humanos , Camundongos , Fosforilação , Tauopatias/patologiaRESUMO
OBJECTIVE: Epidemiological studies reveal that exposure to fine particulate matter (aerodynamic diameter ≤ 2.5 µm, PM 2.5) increases the morbidity and mortality of respiratory diseases. Emerging evidence suggests that human circulating extracellular vesicles (EVs) may offer protective effects against injury caused by particulate matter. Currently, however, whether EVs attenuate PM 2.5-induced A549 cell apoptosis is unknown. METHODS: EVs were isolated from the serum of healthy subjects, quantified via nanoparticle tracking analysis, and qualified by the marker protein CD63. PM 2.5-exposed (50 µg/mL) A549 cells were pre-treated with 10 µg/mL EVs for 24 h. Cell viability, cell apoptosis, and AKT activation were assessed via Cell Counting Kit-8, flow cytometry, and Western blot, respectively. A rescue experiment was also performed using MK2206, an AKT inhibitor. RESULTS: PM 2.5 exposure caused a 100% increase in cell apoptosis. EVs treatment reduced cell apoptosis by 10%, promoted cell survival, and inhibited the PM 2.5-induced upregulation of Bax/Bcl2 and cleaved caspase 3/caspase 3 in PM 2.5-exposed A549 cells. Moreover, EVs treatment reversed PM 2.5-induced reductions in p-AKT Thr308 and p-AKT Ser473. AKT inhibition attenuated the anti-apoptotic effect of EVs treatment on PM 2.5-exposed A549 cells. CONCLUSIONS: EVs treatment promotes cell survival and attenuates PM 2.5-induced cell apoptosis via AKT phosphorylation. Human serum-derived EVs may be an efficacious novel therapeutic strategy in PM 2.5-induced lung injury.
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Poluentes Atmosféricos/toxicidade , Vesículas Extracelulares , Material Particulado/toxicidade , Substâncias Protetoras/farmacologia , Soro , Células A549 , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas c-akt/metabolismoRESUMO
Based on the potent antidepressant and anticonvulsant activities of the triazole-containing quinolinones reported in our previous work, a series of ring-opened derivatives of them were designed, synthesized in this work. Their antidepressant and anticonvulsant activities were screened using the forced swimming test (FST) and the maximal electroshock seizure test (MES), respectively. The results showed that compounds 4a, 5a, 6c-6e, 6g-6i, and 7 led to significant reductions in the accumulated immobility time in the FST at a dose of 50 mg/kg. Especially compound 7 exhibited higher levels of efficacy than the reference standard fluoxetine in the FST and the tail suspension test. The results of an open field test excluded the possibility of central nervous stimulation of 7, which further confirmed its antidepressant effect. Meanwhile, compounds 6a-6i and 7 showed different degrees of anticonvulsant activity in mice at the doses range from 300 to 30 mg/kg in the MES. Among them, compounds 6e and 7 displayed the ED50 of 38.5 and 32.7 mg/kg in the MES, and TD50 of 254.6 and 245.5 mg/kg, respectively. No one showed neurotoxicity at the dose of 100 mg/kg. The preliminary investigation forward to their mechanism indicated that regulation of GABAergic system might contribute to their anticonvulsive and anti-depressive action.
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Anticonvulsivantes/farmacologia , Antidepressivos/farmacologia , Depressão/tratamento farmacológico , Quinolonas/farmacologia , Convulsões/tratamento farmacológico , Triazóis/farmacologia , Animais , Anticonvulsivantes/síntese química , Anticonvulsivantes/química , Antidepressivos/síntese química , Antidepressivos/química , Relação Dose-Resposta a Droga , Aprendizagem em Labirinto/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos , Estrutura Molecular , Quinolonas/síntese química , Quinolonas/química , Relação Estrutura-Atividade , Natação , Triazóis/químicaRESUMO
Adult hippocampal neurogenesis (AHN) deficits contribute to the progression of cognitive impairments during accelerated senescence, with the mechanistic causes poorly understood. Glycogen synthase kinase-3ß (GSK-3ß) is a critical regulator in prenatal neurodevelopment. The present study aims to study whether and how GSK-3ß regulates AHN during the accelerated senescence. Methods: AHN and AHN-dependent cognition and GSK-3ß were evaluated in 3- and 6-month senescence-accelerated mice prone 8 (SAM-P8) and senescence resistant 1 (SAM-R1) mice, respectively. GSK-3ß was selectively overexpressed in wild-type mice using adeno-associated virus, or knocked-out by crossbreeding with GSK-3ß floxed mice in the neural stem cells (NSCs) of Nestin-Cre mice, or pharmacologically inhibited with SB216763 in SAM-P8 mice. AHN was evaluated by BrdU-, DCX-staining and retrovirus-labeling. Results: AHN transiently increased at 3-month, but dramatically dropped at 6-month of age in SAM-P8 mice with a simultaneous activation of GSK-3ß at 3-month. Selective overexpression of GSK-3ß in hippocampal NSCs of wildtype mice induced long-term AHN deficits due to an accelerated depletion of NSC pool, although it transiently increased the proliferation and survival of the newborn neurons. Pharmacologically inhibiting GSK-3ß by SB216763 efficiently preserved AHN and improved contextual memory in 6-month SAM-P8 mice, while conditional knock-out of GSK-3ß in NSCs impaired AHN. Conclusion: Early-stage activation of GSK-3ß in NSCs impairs AHN by accelerating the depletion of NSC pool, and pharmacological inhibition of GSK-3ß is efficient to preserve AHN during the accelerated aging. These results reveal novel mechanisms underlying the AHN impairments during accelerated senescence and provide new targets for pro-neurogenic therapies for related diseases.
Assuntos
Envelhecimento/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Hipocampo/metabolismo , Neurogênese/fisiologia , Envelhecimento/patologia , Animais , Proliferação de Células/fisiologia , Sobrevivência Celular/fisiologia , Disfunção Cognitiva/metabolismo , Disfunção Cognitiva/patologia , Proteína Duplacortina , Hipocampo/patologia , Masculino , Memória/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/patologia , Neurônios/metabolismo , Transdução de Sinais/fisiologiaRESUMO
BACKGROUND: Increased tau acetylation at K174, K274, K280, and K281 has been observed in the brains of Alzheimer's disease (AD) patients or in transgenic mice, but the role of acetylation in tau propagation is elusive. OBJECTIVE: To study the effect of tau acetylation in entorhinal cortex on tau transmission and learning and memory. METHODS: Stereotactic brain injection, behavioral test, electrophysiological recording, immunohistochemistry, and immunofluorescence were used. RESULTS: We constructed the hyperacetylation mimics of tau (AAV-Tau-4Q), the non-acetylation tau mutant (AAV-Tau-4R), and the wild-type tau (AAV-Tau-WT). By overexpressing these different tau proteins in the entorhinal cortex (EC) of 2-month-old mice, we found that overexpressing Tau-4Q in EC for 3 or 6 months (to 5 or 8 months of age) neither induces tau propagation to dentate gyrus (DG) nor glial activation in DG, nor spatial memory deficit. However, overexpressing Tau-WT and Tau-4Q in EC for 13.5 months (15.5 months of age) at 2 months promoted tau propagation respectively to granulosa and hilus of DG with glial activation, synaptic dysfunction, and memory deficit, while overexpressing Tau-4R abolished tau propagation with improved cellular pathologies and cognitive functions. Furthermore, overexpressing Tau-4Q in unilateral DG of 2-month-old mice for 8 weeks also promoted its contralateral transmission with glial activation, and mice with tau (Tau-WT, Tau-4Q, and Tau-4R) overexpression in DG showed cognitive deficits compared with the empty vector controls. CONCLUSION: Tau acetylation induces a time-dependent propagation from EC to DG, and only hippocampus but not EC tau accumulation induces cognitive deficits.
Assuntos
Disfunção Cognitiva/metabolismo , Córtex Entorrinal/metabolismo , Hipocampo/metabolismo , Proteínas tau/metabolismo , Acetilação , Animais , Disfunção Cognitiva/genética , Disfunção Cognitiva/patologia , Córtex Entorrinal/patologia , Hipocampo/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas tau/genéticaRESUMO
Acicular mullite was modified by ferromanganese binary metal oxide (Mn-Fe) to improve the removal efficiency of endocrine disruptors by traditional water treatment practices, using the commercial ceramsite for comparison. The physicochemical properties of synthesized samples were characterized, and batch adsorption experiments were carried out to study the adsorption efficiency of bisphenol A (BPA) and 17α-ethinylestradiol (EE2) on synthesized samples, investigating how solution chemistry and regeneration may affect the adsorption efficiency. Results show that the manganese oxide loaded on the acicular mullite was manganite with an average particle size of 450 nm. After Mn-Fe impregnation, the specific surface area, cumulative pore volume, and mesoporous ratio of the acicular mullite were significantly increased. The virgin acicular mullite had no removal ability for BPA and EE2, and the removal efficiency of BPA and EE2 by Mn-Fe impregnated acicular mullite were significantly increased. Acicular mullite was more suitable as support material for modified filter material. The adsorption kinetics of BPA and EE2 on Mn-Fe-M were fitted with the intra-particle diffusion model, and found to be mainly affected by intra-particle diffusion. The isothermal adsorption data was best fitted to the Langmuir-Freundlich model, and the maximum adsorption capacities of BPA and EE2 were 5.043 mg·g-1 and 3.990 mg·g-1, respectively. Thermodynamic experiments showed that the adsorption of BPA and EE2 by Mn-Fe embedded in acicular mullite was an endothermic reaction, and the temperature increase is beneficial to the adsorption. The adsorption amount of BPA and EE2 on Mn-Fe embedded in acicular mullite decreased with increasing pH. The increase of ionic strength favored the adsorption removal of BPA and EE2. The co-existing anion of SO42- promoted the adsorption of both BPA and EE2, while CO32- and PO43- inhibited the adsorption of both BPA and EE2 on Mn-Fe embedded in acicular mullite. The adsorbent regeneration test showed that Mn-Fe embedded acicular mullite was an easily recyclable adsorbent. Mn-Fe embedded in high-porosity acicular mullite can effectively remove typical endocrine disruptors in water, and it can be potentially extensively used to alleviate the problem of low removal efficiency of endocrine disrupting chemicals in traditional water treatment practice.