RESUMO
In eukaryotic cells, organelles and the cytoskeleton undergo highly dynamic yet organized interactions capable of orchestrating complex cellular functions. Visualizing these interactions requires noninvasive, long-duration imaging of the intracellular environment at high spatiotemporal resolution and low background. To achieve these normally opposing goals, we developed grazing incidence structured illumination microscopy (GI-SIM) that is capable of imaging dynamic events near the basal cell cortex at 97-nm resolution and 266 frames/s over thousands of time points. We employed multi-color GI-SIM to characterize the fast dynamic interactions of diverse organelles and the cytoskeleton, shedding new light on the complex behaviors of these structures. Precise measurements of microtubule growth or shrinkage events helped distinguish among models of microtubule dynamic instability. Analysis of endoplasmic reticulum (ER) interactions with other organelles or microtubules uncovered new ER remodeling mechanisms, such as hitchhiking of the ER on motile organelles. Finally, ER-mitochondria contact sites were found to promote both mitochondrial fission and fusion.
Assuntos
Retículo Endoplasmático/metabolismo , Microtúbulos/metabolismo , Mitocôndrias/metabolismo , Dinâmica Mitocondrial , Animais , Células COS , Linhagem Celular Tumoral , Chlorocebus aethiops , Humanos , Microscopia de FluorescênciaRESUMO
Lysosomes are degradation and signalling centres crucial for homeostasis, development and ageing1. To meet diverse cellular demands, lysosomes remodel their morphology and function through constant fusion and fission2,3. Little is known about the molecular basis of fission. Here we identify HPO-27, a conserved HEAT repeat protein, as a lysosome scission factor in Caenorhabditis elegans. Loss of HPO-27 impairs lysosome fission and leads to an excessive tubular network that ultimately collapses. HPO-27 and its human homologue MROH1 are recruited to lysosomes by RAB-7 and enriched at scission sites. Super-resolution imaging, negative-staining electron microscopy and in vitro reconstitution assays reveal that HPO-27 and MROH1 self-assemble to mediate the constriction and scission of lysosomal tubules in worms and mammalian cells, respectively, and assemble to sever supported membrane tubes in vitro. Loss of HPO-27 affects lysosomal morphology, integrity and degradation activity, which impairs animal development and longevity. Thus, HPO-27 and MROH1 act as self-assembling scission factors to maintain lysosomal homeostasis and function.
Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Lisossomos , Animais , Humanos , Caenorhabditis elegans/citologia , Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/ultraestrutura , Proteínas de Caenorhabditis elegans/química , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/ultraestrutura , Homeostase , Longevidade , Lisossomos/metabolismo , Lisossomos/ultraestrutura , Motivos de Aminoácidos , Microscopia EletrônicaRESUMO
How is the characteristic shape of an organelle generated? Recent work has provided insight into how the tubular network of the endoplasmic reticulum (ER) is formed. The tubules themselves are shaped by the reticulons and DP1/Yop1p, whereas their fusion into a network is brought about by membrane-bound GTPases that include the atlastins, Sey1p, and RHD3.
Assuntos
Retículo Endoplasmático/metabolismo , Animais , Citoesqueleto/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Humanos , Proteínas de Membrana/metabolismo , Organelas/metabolismo , Células Vegetais/metabolismo , Vertebrados , Leveduras/metabolismoRESUMO
The width of cisternal structures in the endoplasmic reticulum (ER) is maintained by the ER-resident protein Climp63 (also known as CKAP4). Self-association of the Climp63 luminal domain (LD), even though moderate, plays a key role in shaping ER sheets. However, the molecular basis of luminal spacing remains elusive. Here, we analyzed the homotypic interactions of the Climp63 LD using deep learning-predicted structures. The LD is highly α-helical, with a flexible leading helix followed by a five-helix bundle (5HB). Charge-based trans associations were formed between the tip of the 5HB and the C-terminus of the LD, consistent with generating a width of â¼50â nm for ER sheets. The leading helix of the LD was dispensable for homotypic interactions but packing of the 5HB regulated self-association. The density of Climp63, likely reflecting the strength of cis interactions, influenced the ER width, which was maintained by trans interactions. These results indicate that a general principle in maintaining membrane tethering is multi-modular self-association.
Assuntos
Retículo Endoplasmático , Retículo Endoplasmático/metabolismoRESUMO
Membrane dynamics are important to the integrity and function of mitochondria. Defective mitochondrial fusion underlies the pathogenesis of multiple diseases. The ability to target fusion highlights the potential to fight life-threatening conditions. Here we report a small molecule agonist, S89, that specifically promotes mitochondrial fusion by targeting endogenous MFN1. S89 interacts directly with a loop region in the helix bundle 2 domain of MFN1 to stimulate GTP hydrolysis and vesicle fusion. GTP loading or competition by S89 dislodges the loop from the GTPase domain and unlocks the molecule. S89 restores mitochondrial and cellular defects caused by mitochondrial DNA mutations, oxidative stress inducer paraquat, ferroptosis inducer RSL3 or CMT2A-causing mutations by boosting endogenous MFN1. Strikingly, S89 effectively eliminates ischemia/reperfusion (I/R)-induced mitochondrial damage and protects mouse heart from I/R injury. These results reveal the priming mechanism for MFNs and provide a therapeutic strategy for mitochondrial diseases when additional mitochondrial fusion is beneficial.
Assuntos
Dinâmica Mitocondrial , Proteínas de Transporte da Membrana Mitocondrial , Camundongos , Animais , Proteínas de Transporte da Membrana Mitocondrial/análise , Proteínas de Transporte da Membrana Mitocondrial/química , Proteínas de Transporte da Membrana Mitocondrial/genética , Mitocôndrias , Hidrólise , Guanosina Trifosfato/análise , Guanosina Trifosfato/farmacologia , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/análise , Proteínas Mitocondriais/farmacologiaRESUMO
SignificanceSonic Hedgehog (Shh) is a key signaling molecule that plays important roles in embryonic patterning, cell differentiation, and organ development. Although fundamentally important, the molecular mechanisms that regulate secretion of newly synthesized Shh are still unclear. Our study reveals a role for the cargo receptor, SURF4, in facilitating export of Shh from the endoplasmic reticulum (ER) via a ER export signal. In addition, our study provides evidence suggesting that proteoglycans promote the dissociation of SURF4 from Shh at the Golgi, suggesting a SURF4-to-proteoglycan relay mechanism. These analyses provide insight into an important question in cell biology: how do cargo receptors capture their clients in one compartment, then disengage at their destination?
Assuntos
Proteínas Hedgehog , Proteínas de Membrana , Proteoglicanas , Retículo Endoplasmático/metabolismo , Proteínas Hedgehog/genética , Proteínas Hedgehog/metabolismo , Humanos , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Transporte Proteico/fisiologia , Proteoglicanas/metabolismoRESUMO
BACKGROUND: Immune checkpoint blockade has emerged as a key strategy to the therapy landscape of non-small cell lung cancer (NSCLC). However, notable differences in immunotherapeutic outcomes exist between the two primary NSCLC subtypes: lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC). This disparity may stem from the tumor immune microenvironment's heterogeneity at the transcriptome level. METHODS: By integrative analysis of transcriptomic characterization of 38 NSCLC patients by single-cell RNA sequencing, the present study revealed a distinct tumor microenvironment (TME) between LUAD and LUSC, with relevant results further confirmed in bulk transcriptomic and multiplex immunofluorescence (mIF) validation cohort of neoadjuvant immunotherapy patients. RESULTS: LUAD exhibited a more active immune microenvironment compared to LUSC. This included highly expression of HLA I/II in cancer cells, reinforced antigen presentation potential of dendritic cells and enhanced cytotoxic activity observed in T/NK cells. In LUSC, cancer cells highly expressed genes belonging to the aldo-keto reductases, glutathione S-transferases and aldehyde dehydrogenase family, negatively correlating with immunotherapy outcomes in the validation cohort of our center. Further analysis revealed elevated infiltrated cancer-associated fibroblasts (CAFs) in LUSC, which was corroborated in The Cancer Genome Atlas cohort. Corresponding increased infiltration of ADH1B+ CAFs in major pathologic response (MPR) patients and the higher presence of FAP+ CAFs in non-MPR patients were demonstrated by multiplex mIF. Moreover, upregulating immunosuppressive extracellular matrix remodeling was identified in LUSC. CONCLUSIONS: These comprehensive analyses advance the understanding of the differences in TME between LUAD and LUSC, offering insights for patient selection and developing subtype-specific treatment strategies.
Assuntos
Adenocarcinoma de Pulmão , Carcinoma de Células Escamosas , Regulação Neoplásica da Expressão Gênica , Imunoterapia , Neoplasias Pulmonares , Análise de Célula Única , Transcriptoma , Microambiente Tumoral , Humanos , Microambiente Tumoral/imunologia , Microambiente Tumoral/genética , Análise de Célula Única/métodos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/terapia , Neoplasias Pulmonares/patologia , Imunoterapia/métodos , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/imunologia , Adenocarcinoma de Pulmão/patologia , Adenocarcinoma de Pulmão/terapia , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/imunologia , Carcinoma de Células Escamosas/terapia , Carcinoma de Células Escamosas/patologia , Perfilação da Expressão Gênica , Masculino , Feminino , Biomarcadores Tumorais/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/imunologia , Carcinoma Pulmonar de Células não Pequenas/terapia , Carcinoma Pulmonar de Células não Pequenas/patologia , Pessoa de Meia-Idade , IdosoRESUMO
Numerous studies have illustrated that the Seneca Valley virus (SVV) shows sufficient oncolytic efficacy targeting small cell lung cancer (SCLC). However, the therapeutics of nonsmall cell lung carcinoma (NSCLC, accounts for 85% of lung cancer cases) using oncolytic virus have been resisting due to the filtration of neutralizing antibody and limited reproduction capacity. Here, we employed structural biology and reverse genetics to optimize novel oncolytic SVV mutants (viral receptor-associated mutant SVV-S177A and viral antigenic peptide-related variant SVV-S177A/P60S) with increased infectivity and lower immunogenicity. The results of the NSCLC-bearing athymic mouse model demonstrated that wild-type (wt) SVV-HB extended the median overall survival (mOS) from 11 days in the PBS group to 19 days. Notably, the newly discovered mutations significantly (P < 0.001) prolonged the mOS from 11 days in the control cohort to 23 days in the SVV-S177A cohort and the SVV-S177A/P60S cohort. Taken together, we present a structure-guided genetic modification strategy for oncolytic SVV optimization and provide a candidate for developing oncolytic viral therapy against nonsensitive NSCLC. IMPORTANCE Nonsmall cell lung cancer (NSCLC) accounts for approximately 85% of lung cancer cases (more than 1.85 million cases with 1.48 million deaths in 2020). In the present study, two novel oncolytic SVV mutants modified based on structural biology and reverse genetics (viral receptor-associated mutant SVV-S177A and viral antigenic peptide-related mutant SVV-S177A/P60S) with increased infectivity or lower immunogenicity significantly (P < 0.001) prolonged the mOS from 11 days in the control cohort to 23 days in the SVV-S177A cohort and the SVV-S177A/P60S cohort in the NSCLC-bearing athymic mouse model, which may provide the direction for modifying SVV to improve the effect of oncolysis.
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Picornaviridae , Animais , Camundongos , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/terapia , Pulmão , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/terapia , Camundongos Nus , Picornaviridae/genéticaRESUMO
Mucin-2 (MUC2) secreted by goblet cells participates in the intestinal barrier, but its mechanism in acute necrotizing pancreatitis (ANP) remains unclear. In acute pancreatitis (AP) patients, the functions of goblet cells (MUC2, FCGBP, CLCA1, and TFF3) decreased, and MUC2 was negatively correlated with AP severity. ANP rats treated with pilocarpine (PILO) (PILO+ANP rats) to deplete MUC2 showed more serious pancreatic and colonic injuries, goblet cell dysfunction, gut dysbiosis, and bacterial translocation than those of ANP rats. GC-MS analysis of feces showed that PILO+ANP rats had lower levels of butyric acid, isobutyric acid, isovaleric acid, and hexanoic acid than those of ANP rats. The expression of MUC2 was associated with colonic injury and gut dysbiosis. All these phenomena could be relieved, and goblet cell functions were also partially reversed by MUC2 supplementation in ANP rats. TNF-α-treated colonoids had exacerbated goblet cell dysfunction. MUC2 expression was negatively correlated with the levels of pro-inflammatory cytokines (IL-1ß and IL-6) (p < .05) and positively related to the expression of tight junction proteins (Claudin 1, Occludin, and ZO1) (p < .05). Downregulating MUC2 by siRNA increased the levels of the pro-inflammatory cytokines in colonoids. MUC2 might maintain intestinal homeostasis to alleviate ANP.
Assuntos
Pancreatite Necrosante Aguda , Ratos , Animais , Mucina-2/genética , Mucina-2/metabolismo , Pancreatite Necrosante Aguda/induzido quimicamente , Pancreatite Necrosante Aguda/tratamento farmacológico , Pancreatite Necrosante Aguda/metabolismo , Disbiose/metabolismo , Doença Aguda , Citocinas/metabolismo , Homeostase , Mucosa Intestinal/metabolismoRESUMO
Pickering emulsions have promising applications in the development of unconventional oil and gas resources. However, the high-temperature environment of the reservoir is not conducive to the stabilization of Pickering emulsions. In addition, the preparation of Pickering emulsions under low-energy emulsification and low-concentration emulsifier conditions is a difficult challenge. Here, we report a high-temperature resistant water-in-paraffin oil Pickering emulsion, which is synergistically stabilized by polyglycerol ester (PGE) and nanoparticles with opposite wettability (lipophilic silica and hydrophilic alumina). This emulsion can be prepared under mild stirring (500 rpm) conditions and can be stable at 140 °C for at least 30 days. The synergistic effects of surfactant, silicon nanoparticles (MSNPs) with different wettability, and alumina nanoparticles (AONPs) on the stability of both emulsions and water-oil interfacial membranes were investigated through bottle experiments, cryogenic scanning electron microscopy (cryo-SEM), optical microscopy, fluorescence microscopy, etc. The results showed that both hydrophobic MSNPs and hydrophilic AONPs are adsorbed together at the water-oil interface to stabilize the W/O emulsion, which can be prepared by 500 rpm stirring. The stability of emulsions strongly depends on the wettability of MSNPs, and the MSNP with moderate hydrophobicity (for example, aqueous phase contact angle of 136°) makes the emulsion exhibit the highest stability against aggregation and settling at elevated temperatures. The emulsion stabilization mechanism was revealed in terms of the adsorption capacity of the surfactant by MSNPs, the adsorption morphology and desorption energy of nanoparticles at the water-oil interface adsorption layer, and emulsion rheology. These findings demonstrate a novel and simple strategy to prepare Pickering W/O emulsions with high-temperature stability at low shear strength.
RESUMO
The endoplasmic reticulum (ER) consists of tubules that are shaped by the reticulons and DP1/Yop1p, but how the tubules form an interconnected network is unknown. Here, we show that mammalian atlastins, which are dynamin-like, integral membrane GTPases, interact with the tubule-shaping proteins. The atlastins localize to the tubular ER and are required for proper network formation in vivo and in vitro. Depletion of the atlastins or overexpression of dominant-negative forms inhibits tubule interconnections. The Sey1p GTPase in S. cerevisiae is likely a functional ortholog of the atlastins; it shares the same signature motifs and membrane topology and interacts genetically and physically with the tubule-shaping proteins. Cells simultaneously lacking Sey1p and a tubule-shaping protein have ER morphology defects. These results indicate that formation of the tubular ER network depends on conserved dynamin-like GTPases. Since atlastin-1 mutations cause a common form of hereditary spastic paraplegia, we suggest ER-shaping defects as a neuropathogenic mechanism.
Assuntos
Dinamina I/metabolismo , Retículo Endoplasmático/metabolismo , GTP Fosfo-Hidrolases/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Animais , Dinaminas/metabolismo , Saccharomyces cerevisiae/metabolismoRESUMO
Species of Baylisascaris (Nematoda: Ascarididae) are of great veterinary and zoonotic significance, owing to cause Baylisascariosis or Baylisascariasis in wildlife, captive animals and humans. However, the phylogenetic relationships of the current 10 Baylisascaris species remain unclear. Moreover, our current knowledge of the detailed morphology and morphometrics of the important zoonotic species B. procyonis is still insufficient. The taxonomical status of B. procyonis and B. columnaris remains under debate. In the present study, the detailed morphology of B. procyonis was studied using light and scanning electron microscopy based on newly collected specimens from the raccoon Procyon lotor (Linnaeus) in China. The results of the ASAP analysis and Bayesian inference (BI) using the 28S, ITS, cox1 and cox2 genetic markers did not support that B. procyonis and B. columnaris represent two distinct species. Integrative morphological and molecular assessment challenged the validity of B. procyonis, and suggested that B. procyonis seems to represent a synonym of B. columnaris. Molecular phylogenetic results indicated that the species of Baylisascaris were grouped into 4 clades according to their host specificity. The present study provided new insights into the taxonomic status of B. procyonis and preliminarily clarified the phylogenetic relationships of Baylisascaris species.
Assuntos
Ascaridídios , Ascaridoidea , Parasitos , Animais , Humanos , Filogenia , Teorema de Bayes , Ascaridoidea/genética , GuaxininsRESUMO
Plant uptake, accumulation, and transformation of organophosphate esters (OPEs) play vital roles in their geochemical cycles and exposure risks. Here we reviewed the recent research advances in OPEs in plants. The mean OPE concentrations based on dry/wet/lipid weight varied in 4.80-3,620/0.287-26.8/12,000-315,000 ng g-1 in field plants, and generally showed positive correlations with those in plant habitats. OPEs with short-chain substituents and high hydrophilicity, particularly the commonly used chlorinated OPEs, showed dominance in most plant samples, whereas some tree barks, fruits, seeds, and roots demonstrated dominance of hydrophobic OPEs. Both hydrophilic and hydrophobic OPEs can enter plants via root and foliar uptake, and the former pathway is mainly passively mediated by various membrane proteins. After entry, different OPEs undergo diverse subcellular distributions and acropetal/basipetal/intergenerational translocations, depending on their physicochemical properties. Hydrophilic OPEs mainly exist in cell sap and show strong transferability, hydrophobic OPEs demonstrate dominant distributions in cell wall and limited migrations owing to the interception of Casparian strips and cell wall. Additionally, plant species, transpiration capacity, growth stages, commensal microorganisms, and habitats also affect OPE uptake and transfer in plants. OPE metabolites derived from various Phase I transformations and Phase II conjugations are increasingly identified in plants, and hydrolysis and hydroxylation are the most common metabolic processes. The metabolisms and products of OPEs are closely associated with their structures and degradation resistance and plant species. In contrast, plant-derived food consumption contributes considerably to the total dietary intakes of OPEs by human, particularly the cereals, and merits specifical attention. Based on the current research limitations, we proposed the research perspectives regarding OPEs in plants, with the emphases on their behavior and fate in field plants, interactions with plant-related microorganisms, multiple uptake pathways and mechanisms, and comprehensive screening analysis and risk evaluation.
Assuntos
Plantas , Humanos , Plantas/metabolismo , Ésteres/metabolismo , Organofosfatos/metabolismo , Poluentes Ambientais/metabolismoRESUMO
Mutations in the human autophagy gene EPG5 cause the multisystem disorder Vici syndrome. Here we demonstrated that EPG5 is a Rab7 effector that determines the fusion specificity of autophagosomes with late endosomes/lysosomes. EPG5 is recruited to late endosomes/lysosomes by direct interaction with Rab7 and the late endosomal/lysosomal R-SNARE VAMP7/8. EPG5 also binds to LC3/LGG-1 (mammalian and C. elegans Atg8 homolog, respectively) and to assembled STX17-SNAP29 Qabc SNARE complexes on autophagosomes. EPG5 stabilizes and facilitates the assembly of STX17-SNAP29-VAMP7/8 trans-SNARE complexes, and promotes STX17-SNAP29-VAMP7-mediated fusion of reconstituted proteoliposomes. Loss of EPG5 activity causes abnormal fusion of autophagosomes with various endocytic vesicles, in part due to elevated assembly of STX17-SNAP25-VAMP8 complexes. SNAP25 knockdown partially suppresses the autophagy defect caused by EPG5 depletion. Our study reveals that EPG5 is a Rab7 effector involved in autophagosome maturation, providing insight into the molecular mechanism underlying Vici syndrome.
Assuntos
Agenesia do Corpo Caloso/genética , Autofagossomos/metabolismo , Catarata/genética , Endossomos/metabolismo , Lisossomos/metabolismo , Proteínas/genética , Proteínas rab de Ligação ao GTP/genética , Agenesia do Corpo Caloso/metabolismo , Agenesia do Corpo Caloso/patologia , Sequência de Aminoácidos , Animais , Autofagossomos/ultraestrutura , Autofagia/genética , Proteínas Relacionadas à Autofagia , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Catarata/metabolismo , Catarata/patologia , Endossomos/ultraestrutura , Regulação da Expressão Gênica , Células HeLa , Humanos , Proteínas de Membrana Lisossomal , Lisossomos/ultraestrutura , Fusão de Membrana , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Ligação Proteica , Proteínas/metabolismo , Proteínas Qa-SNARE/genética , Proteínas Qa-SNARE/metabolismo , Proteínas Qb-SNARE/genética , Proteínas Qb-SNARE/metabolismo , Proteínas Qc-SNARE/genética , Proteínas Qc-SNARE/metabolismo , Proteínas R-SNARE/genética , Proteínas R-SNARE/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Transdução de Sinais , Proteína 25 Associada a Sinaptossoma/genética , Proteína 25 Associada a Sinaptossoma/metabolismo , Proteínas de Transporte Vesicular , Proteínas rab de Ligação ao GTP/metabolismo , proteínas de unión al GTP Rab7RESUMO
The molecular events that determine the recycling versus degradation fates of internalized membrane proteins remain poorly understood. Two of the three members of the SNX-FERM family, SNX17 and SNX31, utilize their FERM domain to mediate endocytic trafficking of cargo proteins harboring the NPxY/NxxY motif. In contrast, SNX27 does not recycle NPxY/NxxY-containing cargo but instead recycles cargo containing PDZ-binding motifs via its PDZ domain. The underlying mechanism governing this divergence in FERM domain binding is poorly understood. Here, we report that the FERM domain of SNX27 is functionally distinct from SNX17 and interacts with a novel DLF motif localized within the N terminus of SNX1/2 instead of the NPxY/NxxY motif in cargo proteins. The SNX27-FERM-SNX1 complex structure reveals that the DLF motif of SNX1 binds to a hydrophobic cave surrounded by positively charged residues on the surface of SNX27. The interaction between SNX27 and SNX1/2 is critical for efficient SNX27 recruitment to endosomes and endocytic recycling of multiple cargoes. Finally, we show that the interaction between SNX27 and SNX1/2 is critical for brain development in zebrafish. Altogether, our study solves a long-standing puzzle in the field and suggests that SNX27 and SNX17 mediate endocytic recycling through fundamentally distinct mechanisms.
Assuntos
Encéfalo/crescimento & desenvolvimento , Domínios FERM , Nexinas de Classificação/metabolismo , Animais , Encéfalo/metabolismo , Endocitose , Transportador de Glucose Tipo 1/metabolismo , Humanos , Neurônios/citologia , Ligação Proteica , Transporte Proteico , Receptor Ativador de Fator Nuclear kappa-B/metabolismo , Nexinas de Classificação/química , Peixe-Zebra/crescimento & desenvolvimento , Peixe-Zebra/metabolismoRESUMO
Polycyclic aromatic hydrocarbons (PAHs) and dioxins are potential causes of multiple diseases by activating the aryl hydrocarbon receptor (AhR) pathway. Health risk assessment of chemicals primarily relies on the relative potency factor (RPF), although its accuracy may be limited when solely using EC50 values. The induction of cytochrome P4501A1 (CYP1A1) serves as a biomarker for AhR activation and is an integrator of dioxin-like toxicity. Here, we present a method for evaluating the risks associated with AhR activation using mathematical models of dose-CYP1A1 induction. The dose-effect curves for certain PAHs and dioxins, including Ant, BghiP, 1,2,3,4,7,8-HxCDD, and others, exhibited a non-classical S-shaped form. The toxic equivalent factor (TEF) profiles revealed a broad range of toxic equivalent factor values. The TEFs for PAHs ranged from approximately 0.01 to 6, with higher values being observed when the concentration was less than 10-10 M, with the exceptions of Ace, Phe, and BghiP. Most congeners of dioxins got the lowest TEF value at around 10-10 M, ranging from 0.04 to 1.00. The binding affinity of AhR to ligands did not display a strong correlation with the EC50 of CYP1A1 expression, suggesting that the AhR-mediated effects of PAHs and dioxins are not fixed but instead fluctuate with the dose. Air samples acquired from a parking area were used to compare the proficiency of RPF and our current approach. In the current method, naphthalene and chrysene were the primary contributors of PAHs to AhR-mediated risks in parking lots air samples, respectively. However, the contributions of naphthalene and chrysene could be disregarded in the RPF approach.
Assuntos
Biomarcadores , Citocromo P-450 CYP1A1 , Dioxinas , Exposição por Inalação , Hidrocarbonetos Policíclicos Aromáticos , Receptores de Hidrocarboneto Arílico , Receptores de Hidrocarboneto Arílico/metabolismo , Citocromo P-450 CYP1A1/metabolismo , Biomarcadores/metabolismo , Biomarcadores/análise , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Hidrocarbonetos Policíclicos Aromáticos/análise , Dioxinas/toxicidade , Medição de Risco , Humanos , Relação Dose-Resposta a DrogaRESUMO
Silica nanoparticles (SiNPs) could induce adverse pulmonary effects, but the mechanism was not clear enough. Metabolomics is a sensitive and high-throughput approach that could investigate the intrinsic causes of adverse health effects caused by SiNPs. The current investigation represented the first in vivo metabolomics study examining the chronic pulmonary toxicity of SiNPs at a low dosage, mimicking real human exposure situation. The recovery process after the cessation of exposure was also taken into consideration. Fisher 344 rats were treated with either saline or SiNPs for 6 months. Half of the animals in each group received an additional six-month period for recovery. The findings indicated that chronic low-level exposure to SiNPs resulted in notable alterations in pulmonary metabolism of amino acids, lipids, carbohydrates, and nucleotides. SiNPs exerted an impact on various metabolites and metabolic pathways which are linked to oxidative stress, inflammation and tumorigenesis. These included but were not limited to L-carnitine, spermidine, taurine, xanthine, and glutathione metabolism. The metabolic alterations caused by SiNPs exhibited a degree of reversibility. However, the interference of SiNPs on two metabolic pathways related to tumorigenesis was observed to persist after a recovery period. The two metabolic pathways are glycerophospholipid metabolism as well as phenylalanine, tyrosine and tryptophan biosynthesis. This study elucidated the metabolic alterations induced by chronic low-level exposure to SiNPs and presented novel evidence of the chronic pulmonary toxicity and carcinogenicity of SiNPs, from a metabolomic perspective.
Assuntos
Pulmão , Nanopartículas , Ratos , Humanos , Animais , Nanopartículas/química , Inflamação/metabolismo , Carcinogênese , Dióxido de Silício/químicaRESUMO
The detection probability of underwater weak targets using active sonar is low, and inter-pulse coherent integration can improve the signal-to-noise ratio of echoes. When a target executes a maneuvering turn, complex range and Doppler frequency migrations occur during the coherent integration time that decrease the coherent integration gain. Most existing integration methods simplify the target motion to a finite-order polynomial model but fail to integrate a maneuvering turning target (MTT) due to model mismatch. Hence, this study proposes an underwater MTT integration method based on the modified Radon-Fourier transform. The proposed method constructs a theoretically accurate motion model for the MTT and a phase compensation function to compensate for the Doppler frequency migration. Furthermore, it yields a well-focused integration peak in the range-velocity and offset angle-turn rate dimensions and accurately estimates the target motion parameters. Moreover, the proposed method is suitable for targets with radial and oblique uniform motions. The effectiveness of the proposed method is demonstrated through simulations and a lake test. The proposed method demonstrates good integration performance, with an integration gain approximately 4-7 dB higher than that of traditional methods when using 30 integration pulses.
RESUMO
The sturgeon is an important commercial aquaculture species in China. The measurement of sturgeon mass plays a remarkable role in aquaculture management. Furthermore, the measurement of sturgeon mass serves as a key phenotype, offering crucial information for enhancing growth traits through genetic improvement. Until now, the measurement of sturgeon mass is usually conducted by manual sampling, which is work intensive and time consuming for farmers and invasive and stressful for the fish. Therefore, a noninvasive volume reconstruction model for estimating the mass of swimming sturgeon based on RGB-D sensor was proposed in this paper. The volume of individual sturgeon was reconstructed by integrating the thickness of the upper surface of the sturgeon, where the difference in depth between the surface and the bottom was used as the thickness measurement. To verify feasibility, three experimental groups were conducted, achieving prediction accuracies of 0.897, 0.861, and 0.883, which indicated that the method can obtain the reliable, accurate mass of the sturgeon. The strategy requires no special hardware or intensive calculation, and it provides a key to uncovering noncontact, high-throughput, and highly sensitive mass evaluation of sturgeon while holding potential for evaluating the mass of other cultured fishes.
Assuntos
Aquicultura , Peixes , Natação , Animais , Peixes/fisiologia , Natação/fisiologia , Aquicultura/métodosRESUMO
To improve the accuracy and efficiency of fish behavior assessment, this paper focuses on quantitatively exploring the variations and relationships between different monitoring dimensions. A systematic comparison was conducted between 3D and 2D behavioral factors using an infrared tracing system, during both day and night. Significant differences in swimming distance were observed among the different monitoring methods, as determined by two-way ANOVA and Tukey's test. A correction was applied to account for the disparities observed in 2D swimming distance, ensuring accurate measurements. These findings present a cost-effective and efficient approach for obtaining precise 3D distance data. Additionally, a kinematic factor called the "number of U-turns" was proposed to provide a more intuitive characterization of directional changes in fish swimming. Significant differences were observed between 2D and 3D data, with higher percentages of false U-turn counts and missing U-turn counts compared to correct counts in the 2D view. These findings suggest that reducing the monitoring dimension may impact the accurate estimation of swimming motion, potentially resulting in inaccurate outcomes. Finally, the statistical analyses of the non-linear properties of fractal dimension revealed significant differences among the various monitoring methods. This conclusion has practical implications for biologists and physicists, enabling them to improve the accuracy of behavioral phenotyping for organisms exhibiting 3D motion.