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Given the promising clinical value of allosteric modulators of G protein-coupled-receptors (GPCRs), mechanistic understanding of how these modulators alter GPCR function is of significance. Here, we report the crystallographic and cryo-electron microscopy structures of the cannabinoid receptor CB1 bound to the positive allosteric modulator (PAM) ZCZ011. These structures show that ZCZ011 binds to an extrahelical site in the transmembrane 2 (TM2)-TM3-TM4 surface. Through (un)biased molecular dynamics simulations and mutagenesis experiments, we show that TM2 rearrangement is critical for the propagation of allosteric signals. ZCZ011 exerts a PAM effect by promoting TM2 rearrangement in favor of receptor activation and increasing the population of receptors that adopt an active conformation. In contrast, ORG27569, a negative allosteric modulator (NAM) of CB1, also binds to the TM2-TM3-TM4 surface and exerts a NAM effect by impeding the TM2 rearrangement. Our findings fill a gap in the understanding of CB1 allosteric regulation and could guide the rational design of CB1 allosteric modulators.
Assuntos
Simulação de Dinâmica Molecular , Receptor CB1 de Canabinoide , Regulação Alostérica , Sítio Alostérico , Microscopia Crioeletrônica , Receptor CB1 de Canabinoide/genéticaRESUMO
BACKGROUND: Hyperhomocysteinemia (HHcy) is an independent risk factor for atherosclerosis (AS). Endothelial mesenchymal transition (EndMT) refers to the process in which endothelial cells lose endothelial cell morphology and characteristic gene expression, and acquire phenotypic characteristics and gene expression related to mesenchymal cells. Numerous studies have confirmed that EndMT is involved in the formation of atherosclerosis. Catalpol is one of the active components of Rehmannia, which has antioxidant, anti-inflammatory, anti-tumor, neuroprotective and other biological activities. Studies have shown that catalpol can reduce atherosclerotic plaque induced by high sugar or fat. However, the effect of catalpol on HHCY-induced EndMT is unclear. METHODS AND RESULTS: In vitro HHcy-treated primary human umbilical vein endothelial cells (HUVECs) were used to construct a cell model, and the antioxidants N-acetylcysteine (NAC) and catalase alcohol were administered. In vivo C57BL/6N mice were given a diet fed with 4.4% high methionine chow to construct a HHcy mice model and were treated with catalpol. The results showed that hhcy could induce morphological transformation of endothelial cells into mesenchymal cells, increase intracellular ROS content, up-regulate α-SMA, N-cadherin, p-p65 protein expression, down-regulate VE-cadherin, CD31 protein expression, induce pathological changes of aortic root endothelium, and increase aortic endothelial ROS content. Catalpol reversed these hhcy induced outcomes. CONCLUSIONS: Catalpol inhibits HHcy-induced EndMT, and the underlying mechanism may be related to the ROS/NF-κB signaling pathway. Catalpol may be a potential drug for the treatment of HHcy-related AS.
Assuntos
Modelos Animais de Doenças , Células Endoteliais da Veia Umbilical Humana , Hiper-Homocisteinemia , Glucosídeos Iridoides , Camundongos Endogâmicos C57BL , NF-kappa B , Espécies Reativas de Oxigênio , Transdução de Sinais , Animais , Células Endoteliais da Veia Umbilical Humana/metabolismo , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/patologia , Humanos , Transdução de Sinais/efeitos dos fármacos , Glucosídeos Iridoides/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Hiper-Homocisteinemia/tratamento farmacológico , Hiper-Homocisteinemia/metabolismo , Hiper-Homocisteinemia/complicações , Células Cultivadas , NF-kappa B/metabolismo , Antioxidantes/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Masculino , Caderinas/metabolismo , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Aterosclerose/patologia , Aterosclerose/metabolismo , Aterosclerose/tratamento farmacológico , Aterosclerose/prevenção & controle , Aterosclerose/etiologia , Fator de Transcrição RelA/metabolismo , Antígenos CD/metabolismo , Transição Endotélio-MesênquimaRESUMO
Long noncoding RNAs have been reported to be involved in the development of breast cancer. LINC01572 was previously reported to promote the development of various tumors. However, the potential biological function of LINC01572 in breast cancer remains largely unknown. R language was used to perform bioinformatic analysis of The Cancer Genome Atlas data. The expression level of RNAs was examined by RT-qPCR. The effect of knocking down or overexpression LINC01572 in triple-negative breast cancer (TNBC) cell lines was evaluated by detecting cell proliferation, migrant action. RNA immunoprecipitation assay and RNA pull-down assay were performed to explore the regulatory relationship between LINC01572, EIF4A3, and ß-catenin. Bioinformatics analysis identifies LINC01572 as an oncogene of breast cancer. LINC01572 is over-expressed in TNBC tissues and cell lines, correlated with poor clinical prognosis in BC patients. Cell function studies confirmed that LINC01572 facilitated the proliferation and migration of TNBC cells in both vivo and vitro. Mechanistically, ß-catenin mRNA and EIF4A3 combine spatially to form a complex, LINC01572 helps transport this complex from the nucleus to the cytoplasm, thereby facilitating the translation of ß-catenin. Our findings confirm that LINC01572 acts as a tumor promoter and may act as a biomarker in TNBC. In addition, novel molecular regulatory relationships involving LINC01572/EIF4A3/ß-catenin are critical to the development of TNBC, which led to a new understanding of the mechanisms of TNBC progression and shows a new target for precision treatment for TNBC.
Assuntos
MicroRNAs , Neoplasias de Mama Triplo Negativas , Humanos , beta Catenina/genética , beta Catenina/metabolismo , Neoplasias de Mama Triplo Negativas/genética , RNA Mensageiro/genética , Linhagem Celular Tumoral , RNA , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Fator de Iniciação 4A em Eucariotos/genética , Fator de Iniciação 4A em Eucariotos/metabolismo , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/metabolismoRESUMO
BACKGROUND AND OBJECTIVES: This study aims to examine the causal relationship between dietary factors and ulcerative colitis (UC). METHODS AND STUDY DESIGN: The analysis utilized data from genome-wide association studies (GWAS). Dried fruit, vegetables, processed meat, fresh fruit, and cereal intake were examined as exposure factors. UC was considered the outcome. Two-sample Mendelian randomization (TSMR) analysis was performed using methods. Heterogeneity and horizontal pleiotropy assessments were conducted to ensure the robustness of our findings. Additionally, we applied False Discovery Rate (FDR) corrections for multiple tests. RESULTS: The analysis revealed a significant inverse causal relationship between dried fruit intake and UC risk (odds ratio [OR]: 0.488, 95% confidence interval [CI]: 0.261 to 0.915, p = 0.025). No significant association was observed between vegetable intake (OR: 1.742, 95% CI: 0.561 to 5.415, p = 0.337), processed meat intake (OR: 1.136, 95% CI: 0.552 to 2.339, p = 0.729), fresh fruit intake (OR: 0.977, 95% CI: 0.465 to 2.054, p = 0.952), cereal intake (OR: 1.195, 95% CI: 0.669 to 2.134, p = 0.547). The low heterogeneity observed across analyses and the confirmation of stability through leave-one-out analysis reinforce the reliability of these results. Moreover, after adjusting for multiple tests, none of the dietary factors reached a p-value below the conventional significance threshold of 0.05. CONCLUSIONS: This study provides evidence of a potential association between dried fruit intake and a reduced risk of UC. Further MR studies incorporating larger GWAS datasets are needed to confirm these findings.
Assuntos
Colite Ulcerativa , Dieta , Frutas , Estudo de Associação Genômica Ampla , Análise da Randomização Mendeliana , Colite Ulcerativa/genética , Humanos , Análise da Randomização Mendeliana/métodos , Dieta/estatística & dados numéricos , Dieta/métodos , Verduras , Fatores de RiscoRESUMO
A series of cellulose-graft-diblock bottlebrush copolymer elastomers (cellulose-graft-poly(n-butyl acrylate)-block-poly(methyl methacrylate) (Cell-g-PBA-b-PMMA)) with short side chains were synthesized via successive atom transfer radical polymerization (ATRP) to study the influence of varying compositions and lengths of the graft diblock side chains on microphase morphologies and properties. The microphase-separated morphologies from misaligned spheres to cylinders were observed by atomic force microscopy (AFM) and small-angle X-ray scattering (SAXS) measurements. These bottlebrush copolymer elastomers possessed thermal stability and enhanced mechanical properties because the PMMA outer block could self-assemble into hard microdomains, which served as physical cross-links. The viscoelastic responses of these bottlebrush copolymers within the linear viscoelastic (LVE) regime were carried out by the oscillatory shear rheology. The time-temperature superposition (tTs) principle was applied to construct the master curves of the dynamic moduli, and the sequential relaxation of dense bottlebrush copolymers with different PMMA hard outer block lengths was analyzed. The rheological behaviors in this work could be utilized to build up the connection of microstructures and properties for the application of these bottlebrush copolymers as high-performance thermoplastic elastomers.
Assuntos
Elastômeros , Nanoestruturas , Elastômeros/química , Celulose/química , Polimetil Metacrilato/química , Espalhamento a Baixo Ângulo , Difração de Raios X , Polímeros/química , Nanoestruturas/química , ReologiaRESUMO
BACKGROUND: Breast cancer (BC) is a common threat to women. The continuous activation of nuclear factor kappa B (NF-κB) signaling pathway contributes to the development of BC. This study aimed to investigate the role of a circular RNA (circRNF10) in BC progression and regulating NF-κB signaling pathway. METHODS: Bioinformatics analysis, RT-qPCR, subcellular fractionation, FISH, RNase R treatment, and actinomycin D assay were used to explore the expression and characteristics of circRNF10 in BC. The biological functions of circRNF10 in BC were analyzed by MTT assay, colony formation assay, wound healing assay, and Transwell assay. RNA pulldown and RIP assay were used to identify the interaction between circRNF10 and DEAH (Asp-Glu-Ala-His) box helicase 15 (DHX15). The impact of circRNF10-DHX15 interaction on NF-κB signaling pathway was explored by western blot, IF, and co-IP. Furthermore, dual-luciferase reporter assay, ChIP, and EMSA were performed to assess the effect of NF-κB p65 on DHX15 transcription. RESULTS: CircRNF10 was downregulated in BC, and lower expression of circRNF10 was related to poor prognosis of patients with BC. CircRNF10 inhibited the proliferation and migration of BC. Mechanically, circRNF10-DHX15 interaction sequestered DHX15 from NF-κB p65, thereby inhibiting the activation of NF-κB signaling pathway. On the other hand, NF-κB p65 enhanced DHX15 transcription by binding to the promoter of DHX15. Altogether, circRNF10 impaired the DHX15-NF-κB p65 positive feedback loop and suppressed the progression of BC. CONCLUSION: CircRNF10-DHX15 interaction suppressed the DHX15-NF-κB p65 positive feedback loop, thereby inhibiting BC progression. These findings provide new insights in the continuous activation of NF-κB signaling pathway and raised potential therapeutic approach for BC treatment.
Assuntos
NF-kappa B , Neoplasias , Feminino , Humanos , Linhagem Celular Tumoral , Retroalimentação , NF-kappa B/metabolismo , Transdução de Sinais , Proteínas do Tecido Nervoso/metabolismo , Proteínas de Transporte/metabolismo , RNA Helicases/metabolismoRESUMO
A symmetry tunable triangular waveform photonic generator based on channelized frequency synthesis is proposed and studied. The generator adopts a multichannel system architecture and harmonic amplitude control algorithm to physically isolate each subchannel. In a single subchannel, quadrature phase shift keying modulation and coherent dual-wavelength balanced detection are used to realize optical upconversion and suppress mixing interference in the process of frequency conversion. Therefore, the model has the characteristics of a high-order Fourier series fitting tunable function waveform output. The analysis results show that the Fourier series harmonic coefficients can be adjusted flexibly by the multivariable joint regulation algorithm. The relationship between the variables is analyzed and discussed. The feasibility of the scheme is verified by optical simulation; when the rms error (RMSE)≤0.03, a 20%-80% tunable symmetry triangular waveform can be obtained.
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Hyperhomocysteinemia (HHcy) is considered to be an independent risk factor for cardiovascular diseases, but the molecular mechanisms underlying its pathogenesis are not fully understood. Endothelial dysfunction is a key initiating factor in the pathogenesis of atherosclerosis, which is commonly observed in almost all HHcy-induced vascular diseases. HHcy promotes oxidative stress, inhibits nitric oxide production, suppresses hydrogen sulfide signaling pathway, promotes endothelial mesenchymal transition, activates coagulation pathways, and promotes protein N-homocysteination and cellular hypomethylation, all of which can cause endothelial dysfunction. This article reviews the specific links between HHcy and endothelial dysfunction, and highlights recent evidence that endothelial mesenchymal transition contributes to HHcy-induced vascular damage, with a hope to provide new ideas for the clinical treatment of HHcy-related vascular diseases.
Assuntos
Aterosclerose , Doenças Cardiovasculares , Hiper-Homocisteinemia , Humanos , Endotélio Vascular , Homocisteína/metabolismo , Hiper-Homocisteinemia/complicações , Estresse Oxidativo , Fatores de RiscoRESUMO
Evidence from experimental and clinical studies implicates immuno-inflammatory responses as playing an important role in epilepsy-induced brain injury. Captopril, an angiotensin-converting enzyme inhibitor (ACEi), has previously been shown to suppress immuno-inflammatory responses in a variety of neurological diseases. However, the therapeutic potential of captopril on epilepsy remains unclear. In the present study, Sprague Dawley (SD) rats were intraperitoneally subjected to kainic acid (KA) to establish a status epilepticus. Captopril (50 mg/kg, i.p.) was administered daily following the KA administration from day 3 to 49. We found that captopril efficiently suppressed the KA-induced epilepsy, as measured by electroencephalography. Moreover, captopril ameliorated the epilepsy-induced cognitive deficits, with improved performance in the Morris water maze, Y-maze and novel objective test. RNA sequencing (RNA-seq) analysis indicated that captopril reversed a wide range of epilepsy-related biological processes, particularly the glial activation, complement system-mediated phagocytosis and the production of inflammatory factors. Interestingly, captopril suppressed the epilepsy-induced activation and abnormal contact between astrocytes and microglia. Immunohistochemical experiments demonstrated that captopril attenuated microglia-dependent synaptic remodeling presumably through C3-C3ar-mediated phagocytosis in the hippocampus. Finally, the above effects of captopril were partially blocked by an intranasal application of recombinant C3a (1.3 µg/kg/day). Our findings demonstrated that captopril reduced the occurrence of epilepsy and cognitive impairment by attenuation of inflammation and C3-mediated synaptic phagocytosis. This approach can easily be adapted to long-term efficacy and safety in clinical practice.
Assuntos
Disfunção Cognitiva , Epilepsia , Animais , Captopril/farmacologia , Captopril/uso terapêutico , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/etiologia , Epilepsia/induzido quimicamente , Epilepsia/tratamento farmacológico , Inflamação/tratamento farmacológico , Ácido Caínico/toxicidade , Fagocitose , Ratos , Ratos Sprague-DawleyRESUMO
Carbon fiber reinforced polymer (CFRP) has been widely used in the aerospace industry and other fields, but its processing is still subject to many restrictions. A femtosecond laser helical drilling device is proposed. It can realize beam deflection and translation through a scanning galvanometer and a pair of lenses, respectively, and finally obtain the effect of beam oblique focusing. With the combination of a spiral scanning path and focus feed, the non-taper and high-quality drilling of materials can be realized. CFRP materials were processed through this method, and the influences of process parameters on the heat affected zone and machining taper were studied. The distribution and influence degree of the heat affected zone and the formation mechanism of the machining taper were analyzed. Finally, a high-quality straight hole processing effect of CFRP with up to a 9.7: 1 aspect ratio, less than 15 µm heat affected zone outside the hole, and no delamination in the hole was realized. This new drilling method is expected to further expand CFRP applications.
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The CB1 receptor mediates the central nervous system response to cannabinoids, and is a drug target for pain, anxiety and seizures. CB1 also responds to allosteric modulators, which influence cannabinoid binding and efficacy. To understand the mechanism of these compounds, we solved the crystal structure of CB1 with the negative allosteric modulator (NAM) ORG27569 and the agonist CP55940. The structure reveals that the NAM binds to an extrahelical site within the inner leaflet of the membrane, which overlaps with a conserved site of cholesterol interaction in many G protein-coupled receptors (GPCRs). The ternary structure with ORG27569 and CP55940 captures an intermediate state of the receptor, in which aromatic residues at the base of the agonist-binding pocket adopt an inactive conformation despite the large contraction of the orthosteric pocket. The structure illustrates a potential strategy for drug modulation of CB1 and other class A GPCRs.
Assuntos
Receptor CB1 de Canabinoide/metabolismo , Regulação Alostérica , Cristalização , Cicloexanóis/farmacologia , Humanos , Ligação Proteica , Receptor CB1 de Canabinoide/agonistasRESUMO
Large squids of the genus Sthenoteuthis are commercially relevant species that include two truly oceanic squids. They are large nektonic predators being widely distributed throughout tropical and subtropical waters of the Atlantic and Indo-Pacific Ocean. The present study investigates different morphs varying in size at maturity, and assesses the genetic divergence in Sthenotheutis in relation to geographic patterns in the South China Sea. We obtained sequences using a mitochondrial (cytochrome c oxidase subunit I) and a nuclear (Histone H3) gene marker from 111 individuals in 23 locations of the South China Sea. In combination with sequences available in public databases, we performed tests on DNA taxonomy, mostly based on molecular phylogenies. Our results suggest that the genus Sthenoteuthis includes at least three species. The Indo-Pacific purpleback squid Sthenoteuthis oualaniensis contains at least two genetically distinct lineages that can be considered separate species, a dwarf species and a medium-sized species, separated by both the mitochondrial marker and the more conserved nuclear marker. We also assessed whether the few cases of mitonuclear discordance could be the result of genetic introgression and past hybridization or incongruence lineage sorting. The medium-sized species is more widely distributed and dominant in the South China Sea than the dwarf species. The medium-sized species inhabits the whole South China Sea, whereas the dwarf species is restricted to the equatorial waters of the South China Sea. The medium-sized species has two further genetic clades, one distributed in the East Pacific Ocean and the other in the South China Sea. This high level of genetic differentiation is in agreement with the discriminant analysis on the morphological measurements, clearly separating the dwarf and medium-sized species, indicating the presence of a complex of pseudo-cryptic species in S. oualaniensis, clearly identifiable by differences in DNA sequences and in body size, and statistically differentiated in their body measurements.
Assuntos
Decapodiformes/classificação , Oceanos e Mares , Filogenia , Animais , Sequência de Bases , Núcleo Celular/genética , China , DNA Mitocondrial/genética , Decapodiformes/genética , Variação Genética , Geografia , Haplótipos/genética , Hibridização Genética , Mitocôndrias/genética , Especificidade da EspécieRESUMO
When studying surface nanobubbles on film-coated substrates, a class of bubble-like domains called blisters are probably forming at the solid-liquid interface together with nanobubbles. This may easily lead to a misunderstanding of the characteristics and applications of surface nanobubbles and thus continue to cause problems within the nanobubble community. Therefore, how to distinguish surface nanobubbles from blisters is a problem. Herein, the morphology and properties of blisters are investigated on both smooth and nanopitted polystyrene (PS) films in degassed water. The morphology and contact angle of blisters are similar to those of surface nanobubbles. However, blisters were observed to be punctured under the tip-blister interaction and be torn broken by an atomic force microscope tip during the process of scanning. At the same time, nanopits on the surface of blisters that formed on a pitted PS film can be seen clearly. These provide direct and visual evidence for distinguishing blisters from surface nanobubbles. In addition, surface nanobubbles and blisters on smooth and pitted PS films in air-equilibrated water are studied. No punctured surface nanobubble was observed, and the force curves obtained on surface nanobubbles and the change in height of blisters and surface nanobubbles under a large scanning force show that surface nanobubbles are much softer than blisters.
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Little data are available on polycyclic aromatic hydrocarbons (PAHs) in marine fish associated with oil and gas activities from the South China Sea (SCS). Twenty-one wild marine fish species from the northern South China Sea were collected for analysis of the presence of polycyclic aromatic hydrocarbons (PAHs). The total concentration of the PAHs (∑16PAHs) ranged from 199 to 606â¯ng·g-1 d.w., indicating moderate contamination. PAHs in fish species found in the Pearl River Delta (PRD) were significantly higher than those from the Yachen (YC) gas fields (pâ¯<â¯0.05). Planktivorous fish exhibited significantly higher concentrations of PAHs than carnivorous and omnivorous fish (pâ¯<â¯0.05). The PAHs were dominated by three ring compounds. Source identification analyses indicated that the PAH pollution originated from petroleum inputs. The cancer and non-cancer risk assessments concluded that the probable risk associated with the intake of PAHs via fish consumption is minimal. Long-term monitoring is necessary to determine the ecological impacts of PAHs associated with oil and gas activities.
Assuntos
Exposição Dietética/análise , Peixes/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Alimentos Marinhos/análise , Poluentes Químicos da Água/metabolismo , Animais , China , Humanos , Petróleo/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Medição de Risco , Poluentes Químicos da Água/análiseRESUMO
Breast cancer (BC) is the most prevalent malignant tumor in women worldwide with high morbidity and mortality. NSUN2, a crucial RNA methyltransferase, plays a pivotal role in regulating the proliferation and metastasis of tumor cells. Our study demonstrated that NSUN2 is upregulated in BC tissues and cell lines, and its high expression is associated with a poor prognosis in BC patients. Knockout of NSUN2 exerted inhibitory effects on the proliferation and migration of BC cells in vitro and in vivo. Mechanistic investigations revealed that the RNA-binding protein ELAVL1 can bind to NSUN2 mRNA and increase its stability. Additionally, we identified HOST2, a long non-coding RNA, as a key player in blocking the ubiquitin-dependent proteasomal degradation of ELAVL1, thereby influencing the stability of NSUN2 mRNA. In conclusion, this study revealed for the first time that HOST2 maintains NSUN2 mRNA stability by blocking ubiquitin-dependent degradation of ELAVL1, which in turn affects BC progression. HOST2/ELAVL1/NSUN2 oncogenic cascade has the potential to be a novel therapeutic target for BC.
Assuntos
Neoplasias da Mama , Proteína Semelhante a ELAV 1 , Metiltransferases , RNA Longo não Codificante , Feminino , Humanos , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células/genética , Proteína Semelhante a ELAV 1/genética , Proteína Semelhante a ELAV 1/metabolismo , Regulação Neoplásica da Expressão Gênica , Metiltransferases/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , RNA Mensageiro/genética , Ubiquitinas/metabolismoRESUMO
BACKGROUND: Paclitaxel (PTX) treatment resistance is an important factor leading to poor prognosis in triple-negative breast cancer (TNBC), therefore there is an urgent need to identify new target for combination therapy. Neddylation is a post-translational process that introduces a ubiquitin-like protein called neural precursor cell expressed developmentally downregulated protein 8 (NEDD8). Previous studies have found that neddylation is activated in multiple tumors, but its relationship with PTX chemotherapy sensitivity has not been reported. METHODS: Differences in UBC12 and NEDD8 expression levels between PTX-sensitive and PTX-insensitive TNBC tissues were validated using public databases and immunohistochemistry. The in vitro and in vivo functional experiments were used to observe the effect of neddylation inhibition combined with PTX therapy on tumor progression. Co-IP, western blot and PCR assays were used to investigate the molecular mechanisms. Molecular docking was used to simulate the protein binding of UBC12 and TRIM25. Molecular dynamics simulation was used to observe the changes in TRIM25 protein conformation. RESULTS: We found that in TNBC that is insensitive to PTX, NEDD8 and NEDD8 conjugating enzyme UBC12 are highly expressed. Treatment with the NEDD8-activating enzyme (NAE) inhibitor mln4924 or knockdown of UBC12 significantly increased the sensitivity of the tumor to PTX, and this increase in sensitivity is related to UBC12-mediated autophagy activation. Mechanistically, UBC12 can transfer NEDD8 to E3 ubiquitin ligase tripartite motif containing 25 (TRIM25) at K117. Molecular dynamics simulations indicate that the neddylation modification of TRIM25 reduces steric hindrance in its RING domain, facilitating the binding of TRIM25 and ubiquitylated substrates. Subsequently, TRIM25 promotes the nuclear translocation of transcription factor EB (TFEB) and transcription of autophagy related genes by increasing K63-polyubiquitination of TFEB, thereby reducing tumor sensitivity to PTX. CONCLUSIONS: Neddylation is activated in PTX-insensitive TNBC. Specifically, autophagy gene transcriptional activation mediated by the UBC12/TRIM25/TFEB axis reduces TNBC sensitivity to PTX. Neddylation suppression combination with PTX treatment shows a synergistic anti-tumor effect.
Assuntos
Autofagia , Proteína NEDD8 , Paclitaxel , Proteínas com Motivo Tripartido , Neoplasias de Mama Triplo Negativas , Ubiquitina-Proteína Ligases , Humanos , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/patologia , Paclitaxel/farmacologia , Paclitaxel/uso terapêutico , Feminino , Camundongos , Animais , Autofagia/efeitos dos fármacos , Proteína NEDD8/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , Proteínas com Motivo Tripartido/metabolismo , Proteínas com Motivo Tripartido/genética , Linhagem Celular Tumoral , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Ciclopentanos/farmacologia , Resistencia a Medicamentos Antineoplásicos , Ensaios Antitumorais Modelo de Xenoenxerto , Enzimas de Conjugação de Ubiquitina/metabolismo , Enzimas de Conjugação de Ubiquitina/genéticaRESUMO
Polystyrene polymers cause severe toxicity to aquatic animals. However, the process and mechanisms of innate immunity of invertebrates living at the bottom of the food chain to these pollutants remain unclear. In this study, the blood system responses of zooplankton Artemia were assessed through in vivo and in vitro exposure to amino-modified polystyrene nanoplastics (PS-NH2 NPs). The results indicated that the LC50 values of PS-NH2 NPs were 1.09 µg·mL-1 over 48 h and 0.42 µg·mL-1 over 7 d. Based on the five hemocyte subpopulations identified in Artemia, in vitro exposure assays revealed that phagocytosis was performed by plasmocytes and granulocytes with phagocytic rate of 22.64 %. TEM analysis further showed that PS-NH2 NPs caused cytoplasm vacuolization, swollen mitochondria, and lipid processing disorder. Gene expression pattern results demonstrated that Spatzle, Tollip, Hsp70, Hsp90, Casp8, API5and Pxn were significantly upregulated upon acute and chronic exposure (p < 0.05), while chronic exposure could induce significantly upregulation of ProPO (p < 0.05). Moreover, PS-NH2 NPs exposure remarkably varied the hemolymph microbiota and hemogram, particularly by increasing the proportion of adipohemocytes and phagocytes (p < 0.05). Our findings suggest that PS-NH2 NPs induce different responses in Artemia hemocyte, as primarily reflected by phagocytic processes, expression of immune and apoptosis relating genes, cell fates, hemogram and hemolymph microbiota variations. These findings support the possibility of using Artemia hemocytes as bioindicator to estimate nanoplastics pollution, thus contributing to hematological toxicity research in response to nanoplastics.
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Artemia , Hemócitos , Nanopartículas , Fagocitose , Poliestirenos , Animais , Hemócitos/efeitos dos fármacos , Hemócitos/imunologia , Poliestirenos/toxicidade , Artemia/efeitos dos fármacos , Nanopartículas/toxicidade , Fagocitose/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Microplásticos/toxicidade , Imunidade Inata/efeitos dos fármacosRESUMO
Immunotherapy based on PD-1/PD-L1 antagonists has been demonstrated to be efficacious in inducing tumor remission in patients with triple-negative breast cancer (TNBC). However, tumor immune evasion caused by the PD-1/PD-L1 pathway inhibits the immunotherapeutic effect of PD-1/PD-L1 inhibitors against TNBC. Therefore, identifying potential targets for blocking the PD-1/PD-L1 pathway is a compelling strategy for TNBC treatment. Here, we discovered that VGLL4 could inhibit PD-L1 transcription by suppressing STAT3 activation, thereby enhancing the efficacy of anti-PD-1 antibody immunotherapy in TNBC. Low expression of USP15, a deubiquitinating enzyme of VGLL4, was associated with reduced CD8+ T cell infiltration and poor prognosis in TNBC patients. USP15 was found to inhibit PD-L1 transcription, leading to increased CD8+ T cell infiltration and thus enhancing the efficacy of TNBC immunotherapy. Furthermore, SART3 regulated VGLL4 stability and PD-L1 transcription by influencing the nuclear translocation of USP15. In conclusion, our study provides new insights into the biological regulation of PD-L1, identifies a previously unrecognized regulator of this critical immune checkpoint, and highlights potential therapeutic targets for overcoming immune evasion in TNBC.
Assuntos
Neoplasias de Mama Triplo Negativas , Humanos , Linhagem Celular Tumoral , Neoplasias de Mama Triplo Negativas/terapia , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Antígeno B7-H1 , Receptor de Morte Celular Programada 1/metabolismo , Imunoterapia , Antígenos de Neoplasias/uso terapêutico , Proteínas de Ligação a RNA , Fatores de Transcrição/metabolismo , Proteases Específicas de Ubiquitina/metabolismoRESUMO
Synapse organizers are essential for the development, transmission, and plasticity of synapses. Acting as rare synapse suppressors, the MAM domain containing glycosylphosphatidylinositol anchor (MDGA) proteins contributes to synapse organization by inhibiting the formation of the synaptogenic neuroligin-neurexin complex. A previous analysis of MDGA2 mice lacking a single copy of Mdga2 revealed upregulated glutamatergic synapses and behaviors consistent with autism. However, MDGA2 is expressed in diverse cell types and is localized to both excitatory and inhibitory synapses. Differentiating the network versus cell-specific effects of MDGA2 loss-of-function requires a cell-type and brain region-selective strategy. To address this, we generated mice harboring a conditional knockout of Mdga2 restricted to CA1 pyramidal neurons. Here we report that MDGA2 suppresses the density and function of excitatory synapses selectively on pyramidal neurons in the mature hippocampus. Conditional deletion of Mdga2 in CA1 pyramidal neurons of adult mice upregulated miniature and spontaneous excitatory postsynaptic potentials, vesicular glutamate transporter 1 intensity, and neuronal excitability. These effects were limited to glutamatergic synapses as no changes were detected in miniature and spontaneous inhibitory postsynaptic potential properties or vesicular GABA transporter intensity. Functionally, evoked basal synaptic transmission and AMPAR receptor currents were enhanced at glutamatergic inputs. At a behavioral level, memory appeared to be compromised in Mdga2 cKO mice as both novel object recognition and contextual fear conditioning performance were impaired, consistent with deficits in long-term potentiation in the CA3-CA1 pathway. Social affiliation, a behavioral analog of social deficits in autism, was similarly compromised. These results demonstrate that MDGA2 confines the properties of excitatory synapses to CA1 neurons in mature hippocampal circuits, thereby optimizing this network for plasticity, cognition, and social behaviors.
Assuntos
Região CA1 Hipocampal , Plasticidade Neuronal , Células Piramidais , Comportamento Social , Sinapses , Animais , Masculino , Camundongos , Região CA1 Hipocampal/metabolismo , Região CA1 Hipocampal/fisiologia , Potenciais Pós-Sinápticos Excitadores/fisiologia , Ácido Glutâmico/metabolismo , Memória/fisiologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Plasticidade Neuronal/fisiologia , Células Piramidais/fisiologia , Células Piramidais/metabolismo , Sinapses/metabolismo , Sinapses/fisiologiaRESUMO
Breast cancer has the highest global incidence and mortality rates among all cancer types. Abnormal expression of the Annexin family has been observed in different malignant tumors, including upregulated ANXA9 in breast cancer. We found highly expressed ANXA9 in metastatic breast cancer tissues, which is correlated with breast cancer progression. In vitro, the functional experiments indicated ANXA9 influenced breast cancer proliferation, motility, invasion, and apoptosis; in vivo, downregulation of ANXA9 suppressed breast cancer xenograft tumor growth and lung metastasis. Mechanically, on one side, we found that ANXA9 could mediate S100A4 and therefore regulate AKT/mTOR/STAT3 pathway to participate p53/Bcl-2 apoptosis; on the other side, we found ANXA9 transferred S100A4 from cells into the tumor microenvironment and mediated the excretion of cytokines IL-6, IL-8, CCL2, and CCL5 to participate angiogenesis via self- phosphorylation at site Ser2 and site Thr69. Our findings demonstrate significant involvement of ANXA9 in promoting breast cancer progression, thereby suggesting that therapeutic intervention via targeting ANXA9 may be effective in treating metastatic breast cancer.