RESUMO
Human DDX5 and its yeast ortholog Dbp2 are ATP-dependent RNA helicases that play a key role in normal cell processes, cancer development, and viral infection. The crystal structure of the RecA1-like domain of DDX5 is available but the global structure of DDX5/Dbp2 subfamily proteins remains to be elucidated. Here, we report the first X-ray crystal structures of the Dbp2 helicase core alone and in complex with ADP at 3.22 Å and 3.05 Å resolutions, respectively. The structures of the ADP-bound post-hydrolysis state and apo-state demonstrate the conformational changes that occur when the nucleotides are released. Our results showed that the helicase core of Dbp2 shifted between open and closed conformation in solution but the unwinding activity was hindered when the helicase core was restricted to a single conformation. A small-angle X-ray scattering experiment showed that the disordered amino (N) tail and carboxy (C) tails are flexible in solution. Truncation mutations confirmed that the terminal tails were critical for the nucleic acid binding, ATPase, and unwinding activities, with the C-tail being exclusively responsible for the annealing activity. Furthermore, we labeled the terminal tails to observe the conformational changes between the disordered tails and the helicase core upon binding nucleic acid substrates. Specifically, we found that the nonstructural terminal tails bind to RNA substrates and tether them to the helicase core domain, thereby conferring full helicase activities to the Dbp2 protein. This distinct structural characteristic provides new insight into the mechanism of DEAD-box RNA helicases.
Assuntos
RNA Helicases DEAD-box , Proteínas de Saccharomyces cerevisiae , Humanos , RNA Helicases DEAD-box/metabolismo , RNA/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Conformação Molecular , DNA Helicases/metabolismoRESUMO
Juvenile myelomonocytic leukaemia (JMML) is a rare myeloproliferative neoplasm requiring haematopoietic stem cell transplantation (HSCT) for potential cure. Relapse poses a significant obstacle to JMML HSCT treatment, as the lack of effective minimal residual disease (MRD)-monitoring methods leads to delayed interventions. This retrospective study utilized the droplet digital PCR (ddPCR) technique, a highly sensitive nucleic acid detection and quantification technique, to monitor MRD in 32 JMML patients. The results demonstrated that ddPCR detected relapse manifestations earlier than traditional methods and uncovered molecular insights into JMML MRD dynamics. The findings emphasized a critical 1- to 3-month window post-HSCT for detecting molecular relapse, with 66.7% (8/12) of relapses occurring within this period. Slow MRD clearance post-HSCT was observed, as 65% (13/20) of non-relapse patients took over 6 months to achieve ddPCR-MRD negativity. Furthermore, bone marrow ddPCR-MRD levels at 1-month post-HSCT proved to be prognostically significant. Relapsed patients exhibited significantly elevated ddPCR-MRD levels at this time point (p = 0.026), with a cut-off of 0.465% effectively stratifying overall survival (p = 0.007), event-free survival (p = 0.035) and cumulative incidence of relapse (p = 0.035). In conclusion, this study underscored ddPCR's superiority in JMML MRD monitoring post-HSCT. It provided valuable insights into JMML MRD dynamics, offering guidance for the effective management of JMML.
Assuntos
Transplante de Células-Tronco Hematopoéticas , Leucemia Mielomonocítica Juvenil , Neoplasia Residual , Reação em Cadeia da Polimerase , Humanos , Neoplasia Residual/diagnóstico , Masculino , Feminino , Reação em Cadeia da Polimerase/métodos , Leucemia Mielomonocítica Juvenil/terapia , Leucemia Mielomonocítica Juvenil/genética , Leucemia Mielomonocítica Juvenil/diagnóstico , Estudos Retrospectivos , Prognóstico , Pré-Escolar , Lactente , CriançaRESUMO
Vascular endothelial cells play a critical role in maintaining the health of blood vessels, but dysfunction can lead to cardiovascular diseases. The impact of arsenite exposure on cardiovascular health is a significant concern due to its potential adverse effects. This study aims to explore how NBR1-mediated autophagy in vascular endothelial cells can protect against oxidative stress and apoptosis induced by arsenite. Initially, our observations revealed that arsenite exposure increased oxidative stress and triggered apoptotic cell death in human umbilical vein endothelial cells (HUVECs). However, treatment with the apoptosis inhibitor Z-VAD-FMK notably reduced arsenite-induced apoptosis. Additionally, arsenite activated the autophagy pathway and enhanced autophagic flux in HUVECs. Interestingly, inhibition of autophagy exacerbated arsenite-induced apoptotic cell death. Our findings also demonstrated the importance of autophagy receptor NBR1 in arsenite-induced cytotoxicity, as it facilitated the recruitment of caspase 8 to autophagosomes for degradation. The protective effect of NBR1 against arsenite-induced apoptosis was compromised when autophagy was inhibited using pharmacological inhibitors or through genetic knockdown of essential autophagy genes. Conversely, overexpression of NBR1 facilitated caspase 8 degradation and reduced apoptotic cell death in arsenite-treated HUVECs. In conclusion, our study highlights the vital role of NBR1-mediated autophagic degradation of caspase 8 in safeguarding vascular endothelial cells from arsenite-induced oxidative stress and apoptotic cell death. Targeting this pathway could offer a promising therapeutic approach to mitigate cardiovascular diseases associated with arsenite exposure.
Assuntos
Apoptose , Arsenitos , Autofagia , Caspase 8 , Células Endoteliais da Veia Umbilical Humana , Estresse Oxidativo , Humanos , Arsenitos/toxicidade , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Caspase 8/metabolismo , Caspase 8/genética , Estresse Oxidativo/efeitos dos fármacos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteólise/efeitos dos fármacos , Células CultivadasRESUMO
OBJECTIVE: To systematically evaluate the perioperative effects of enhanced recovery after surgery (ERAS) protocol on anterior cervical spine surgery by means of meta-analysis. METHODS: According to the PRISMA guidelines, the article's search on the China National Knowledge Infrastructure (CNKI), Wanfang data resource system, VIP, PubMed database and Cochrane library was conducted to identify clinical studies investigating the effects of ERAS protocols on anterior cervical spine surgery. A quantitative meta-analysis was performed for the clinical outcomes extracted from the studies that met inclusion criteria. RESULTS: Of the 21 studies identified from the article search, 10 studies met inclusion criteria. The meta-analysis showed shorter length of stay (LOS) (MD = -2.16, 95% CI (-2.57, -1.75), P < 0.00001) and higher patient satisfaction for the ERAS protocols (OR = 3.13, 95% CI (1.97, 4.98), P < 0.00001). Furthermore, ERAS programs led to significant decreases in cost (MD = -0.81, 95% CI (-1.08, -0.53), P < 0.00001) and complication rates (OR = 0.15, 95% CI (0.08, 0.27), P < 0.00001), but no difference in 90-day readmission (OR = 0.63, 95% CI (0.30, 1.35), P = 0.24). CONCLUSIONS: The data of this study suggest that the implementation of ERAS protocol decreases LOS, cost and complications rates and improve satisfaction for the patients undergoing anterior cervical spine surgery. To support the practice use of ERAS in anterior cervical spine surgery further, controlled trials will be indispensable.
Assuntos
Vértebras Cervicais , Recuperação Pós-Cirúrgica Melhorada , Humanos , Vértebras Cervicais/cirurgia , Tempo de Internação/estatística & dados numéricos , Doenças da Coluna Vertebral/cirurgia , Satisfação do PacienteRESUMO
Extinguishing the previously acquired fear is critical for the adaptation of an organism to the ever-changing environment, a process requiring the engagement of GABAA receptors (GABAARs). GABAARs consist of tens of structurally, pharmacologically, and functionally heterogeneous subtypes. However, the specific roles of these subtypes in fear extinction remain largely unexplored. Here, we observed that in the medial prefrontal cortex (mPFC), a core region for mood regulation, the extrasynaptically situated, δ-subunit-containing GABAARs [GABAA(δ)Rs], had a permissive role in tuning fear extinction in male mice, an effect sharply contrasting to the established but suppressive role by the whole GABAAR family. First, the fear extinction in individual mice was positively correlated with the level of GABAA(δ)R expression and function in their mPFC. Second, knockdown of GABAA(δ)R in mPFC, specifically in its infralimbic (IL) subregion, sufficed to impair the fear extinction in mice. Third, GABAA(δ)R-deficient mice also showed fear extinction deficits, and re-expressing GABAA(δ)Rs in the IL of these mice rescued the impaired extinction. Further mechanistic studies demonstrated that the permissive effect of GABAA(δ)R was associated with its role in enabling the extinction-evoked plastic regulation of neuronal excitability in IL projection neurons. By contrast, GABAA(δ)R had little influence on the extinction-evoked plasticity of glutamatergic transmission in these cells. Altogether, our findings revealed an unconventional and permissive role of extrasynaptic GABAA receptors in fear extinction through a route relying on nonsynaptic plasticity.SIGNIFICANCE STATEMENT The medial prefrontal cortex (mPFC) is one of the kernel brain regions engaged in fear extinction. Previous studies have repetitively shown that the GABAA receptor (GABAAR) family in this region act to suppress fear extinction. However, the roles of specific GABAAR subtypes in mPFC are largely unknown. We observed that the GABAAR-containing δ-subunit [GABAA(δ)R], a subtype of GABAARs exclusively situated in the extrasynaptic membrane and mediating the tonic neuronal inhibition, works oppositely to the whole GABAAR family and promotes (but does not suppress) fear extinction. More interestingly, in striking contrast to the synaptic GABAARs that suppress fear extinction by breaking the extinction-evoked plasticity of glutamatergic transmission, the GABAA(δ)R promotes fear extinction through enabling the plastic regulation of neuronal excitability in the infralimbic subregion of mPFC. Our findings thus reveal an unconventional role of GABAA(δ)R in promoting fear extinction through a route relying on nonsynaptic plasticity.
Assuntos
Extinção Psicológica , Medo , Animais , Medo/fisiologia , Masculino , Camundongos , Neurônios/metabolismo , Plásticos/metabolismo , Plásticos/farmacologia , Córtex Pré-Frontal/fisiologia , Receptores de GABA-A/metabolismo , Ácido gama-Aminobutírico/farmacologiaRESUMO
Juvenile myelomonocytic leukaemia (JMML) is an aggressive paediatric leukaemia characterized by mutations in five canonical RAS pathway genes, including the NF1 gene. JMML is driven by germline NF1 gene mutations, with additional somatic aberrations resulting in the NF1 biallelic inactivation, leading to disease progression. Germline mutations in the NF1 gene alone primarily cause benign neurofibromatosis type 1 (NF1) tumours rather than malignant JMML, yet the underlying mechanism remains unclear. Here, we demonstrate that with reduced NF1 gene dose, immune cells are promoted in anti-tumour immune response. Comparing the biological properties of JMML and NF1 patients, we found that not only JMML but also NF1 patients driven by NF1 mutations could increase monocytes generation. But monocytes cannot further malignant development in NF1 patients. Utilizing haematopoietic and macrophage differentiation from iPSCs, we revealed that NF1 mutations or knockout (KO) recapitulated the classical haematopoietic pathological features of JMML with reduced NF1 gene dose. NF1 mutations or KO promoted the proliferation and immune function of NK cells and iMacs derived from iPSCs. Moreover, NF1-mutated iNKs had a high capacity to kill NF1-KO iMacs. NF1-mutated or KO iNKs administration delayed leukaemia progression in a xenograft animal model. Our findings demonstrate that germline NF1 mutations alone cannot directly drive JMML development and suggest a potential cell immunotherapy for JMML patients.
Assuntos
Leucemia Mielomonocítica Juvenil , Neurofibromatose 1 , Animais , Humanos , Leucemia Mielomonocítica Juvenil/genética , Leucemia Mielomonocítica Juvenil/terapia , Leucemia Mielomonocítica Juvenil/metabolismo , Neurofibromina 1/genética , Genes da Neurofibromatose 1 , Mutação em Linhagem Germinativa , Neurofibromatose 1/genética , Neurofibromatose 1/terapia , Mutação , Imunidade , Células Germinativas/metabolismo , Células Germinativas/patologiaRESUMO
As one of the most significant imaging modalities currently available, magnetic resonance imaging (MRI) has been extensively utilized for clinically accurate cancer diagnosis. However, low signal-to-noise ratio (SNR) and low specificity for tumors continue to pose significant challenges. Inspired by the distance-dependent magnetic resonance tuning (MRET) phenomenon, the tumor microenvironment (TME)-activated off-on T1-T2 dual-mode MRI nanoswitch is presented in the current study to realize the sensitive early diagnosis of tumors. The tumor-specific nanoswitch is designed and manufactured on the basis of PDGFB-conjugating ferroferric oxide coated by Mn-doped silica (PDGFB-FMS), which can be degraded under the high-concentration GSH and low pH in TME to activate the T1-T2 dual-mode MRI signals. The tumor-specific off-on dual-mode MRI nanoswitch can significantly improve the SNR and is used successfully for the accurate diagnosis of early-stage tumors, particularly for orthotopic prostate cancer. In addition, the systemic delivery of the nanoswitch did not cause blood or tissue damage, and it can be excreted out of the body in a timely manner, demonstrating excellent biosafety. Overall, the strategy is a significant step in the direction of designing off-on dual-mode MRI nanoprobes to improve imaging accuracy, which opens up new avenues for the development of new MRI probes.
Assuntos
Meios de Contraste , Neoplasias , Masculino , Humanos , Proteínas Proto-Oncogênicas c-sis , Neoplasias/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Dióxido de Silício , Microambiente TumoralRESUMO
Arsenite is a well-documented neurotoxic metalloid that widely distributes in the natural environment. However, it remains largely unclear how arsenite affects neurological function. Therefore, in this study, the healthy adult male mice were exposed to 0.5 mg/L and 5â¯mg/L arsenite through drinking water for 30 and 90 days, respectively. Our results showed that there was no significant alteration in the intestine and brain for 30 days exposure, but exposure to arsenite for 90 days significantly induced a reduction of locomotor activity and anxiety-like behavior, caused pathological damage and inflammatory responses in the brain and intestine. We also found that arsenite remarkably disrupted intestinal barrier integrity, decreased the levels of lysozyme and digestive enzymes. Intriguingly, chronic exposure to arsenite significantly changed the levels of gut-brain peptides. Taken together, this study provides meaningful insights that gut-brain communication may involve in the neurobehavioral impairments of arsenite.
Assuntos
Arsenitos , Camundongos , Animais , Masculino , Arsenitos/toxicidade , Encéfalo/patologiaRESUMO
With the rapid development of nanotechnology, the risks of accidental and/or occupational exposure to zinc oxide nanoparticles (ZnONPs) are increasing. Inhalation of ZnONPs induces metal fume fever in humans and acute lung injury (ALI) in animal models. Although the intestinal microbiota is considered an important modulator of various diseases, the role and mechanism of intestinal microbiota in the pathology of ZnONP-induced ALI are unclear. Herein, we established an intratracheal instillation of a ZnONP-induced ALI mouse model and found that the inhalation of ZnONPs caused ALI along with a perturbation of intestinal flora. Antibiotic cocktail treatment-mediated depletion of intestinal microbiota aggravated ZnONP-induced ALI, and in contrast, fecal microbiota transplantation-mediated restoration of intestinal microbiota exerted the opposite effects. A decrease in short-chain fatty acids, the intestinal microbiota-derived metabolites in the plasma-in particular, acetic acid and propionic acid-occurred after exposure to ZnONPs. It is important to note that supplementation with propionic acid, but not acetic acid, ameliorated ZnONP-induced ALI. We also showed that the source of inflammatory cytokines might partially be the infiltration of macrophages. Supplementation with propionic acid was found to act on macrophages through the receptor GPR43, because knockdown of GPR43 sharply reversed the protective effects of propionic acid during the ZnONP-induced inflammatory response and oxidative stress in both primary alveolar macrophages and RAW 264.7 macrophage cell lines. Altogether, a novel gut-lung axis mechanism is revealed in which intestinal microbiota and their derived metabolite propionic acid play protective roles against ZnONP-induced ALI and suggest that fecal microbiota transplantation and supplementation with propionic acid are potential remedy strategies.
Assuntos
Lesão Pulmonar Aguda , Microbioma Gastrointestinal , Nanopartículas , Óxido de Zinco , Camundongos , Humanos , Animais , Óxido de Zinco/farmacologia , Propionatos/farmacologia , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/prevenção & controle , AcetatosRESUMO
G-quadruplexes (G4s) are important in regulating DNA replication, repair and RNA transcription through interactions with specialized proteins. Dbp2 has been identified as a G4 DNA binding protein from Saccharomyces cerevisiae cell lysates. The majority of G4 motifs in Saccharomyces cerevisiae display 5-50 nt loops, only a few have 1-2 nt loops. Human DDX5 could unfold MycG4 DNA, whether Dbp2 also participates in remodeling G4 motifs with short loops in Saccharomyces cerevisiae remains elusive. Here we find that Dbp2 prefers G-rich substrates and binds MycG4 with a high affinity. Dbp2 possesses a dual function for different conformations of MycG4, destabilizing the folded MycG4 and inducing further folding of the unfolded MycG4. Similarly, DDX5 can unfold MycG4, but it exhibits a weaker MycG4 folding-promoting activity relative to Dbp2. Furthermore, Dbp2 facilitates DNA annealing activity in the absence of ATP, suggesting that Dbp2 can work on DNA substrates and possibly participate in DNA metabolism. Our results demonstrate that Dbp2 plays an important role in regulating the folding and unfolding activities of MycG4.
Assuntos
Quadruplex G , Proteínas de Saccharomyces cerevisiae , Humanos , RNA Helicases DEAD-box/metabolismo , DNA/química , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismoRESUMO
BACKGROUND: SARS-CoV-2 infection leads to acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Both clinical data and animal experiments suggest that the renin-angiotensin system (RAS) is involved in the pathogenesis of SARS-CoV-2-induced ALI. Angiotensin-converting enzyme 2 (ACE2) is the functional receptor for SARS-CoV-2 and a crucial negative regulator of RAS. Recombinant ACE2 protein (rACE2) has been demonstrated to play protective role against SARS-CoV and avian influenza-induced ALI, and more relevant, rACE2 inhibits SARS-CoV-2 proliferation in vitro. However, whether rACE2 protects against SARS-CoV-2-induced ALI in animal models and the underlying mechanisms have yet to be elucidated. METHODS AND RESULTS: Here, we demonstrated that the SARS-CoV-2 spike receptor-binding domain (RBD) protein aggravated lipopolysaccharide (LPS)-induced ALI in mice. SARS-CoV-2 spike RBD protein directly binds and downregulated ACE2, leading to an elevation in angiotensin (Ang) II. AngII further increased the NOX1/2 through AT1R, subsequently causing oxidative stress and uncontrolled inflammation and eventually resulting in ALI/ARDS. Importantly, rACE2 remarkably reversed SARS-CoV-2 spike RBD protein-induced ALI by directly binding SARS-CoV-2 spike RBD protein, cleaving AngI or cleaving AngII. CONCLUSION: This study is the first to prove that rACE2 plays a protective role against SARS-CoV-2 spike RBD protein-aggravated LPS-induced ALI in an animal model and illustrate the mechanism by which the ACE2-AngII-AT1R-NOX1/2 axis might contribute to SARS-CoV-2-induced ALI.
Assuntos
Lesão Pulmonar Aguda , Enzima de Conversão de Angiotensina 2 , COVID-19 , Síndrome do Desconforto Respiratório , Lesão Pulmonar Aguda/prevenção & controle , Lesão Pulmonar Aguda/virologia , Angiotensina II , Enzima de Conversão de Angiotensina 2/uso terapêutico , Animais , COVID-19/complicações , Humanos , Lipopolissacarídeos , Camundongos , Proteínas Recombinantes/uso terapêutico , SARS-CoV-2 , Glicoproteína da Espícula de CoronavírusRESUMO
The application of chemodynamic therapy (CDT) for cancer is a serious challenge owing to the low efficiency of the Fenton catalyst and insufficient H2O2 expression in cells. Herein, we fabricated a PDGFB targeting, biodegradable FePt alloy assembly for magnetic resonance imaging (MRI)-guided chemotherapy and starving-enhanced chemodynamic therapy for cancer using PDGFB targeting, pH-sensitive liposome-coated FePt alloys, and GOx (pLFePt-GOx). We found that the Fenton-catalytic activity of FePt alloys was far stronger than that of traditional ultrasmall iron oxide nanoparticle (UION). Upon entry into cancer cells, pLFePt-GOx nanoliposomes degraded into many tiny FePt alloys and released GOx owing to the weakly acidic nature of the tumor microenvironment (TME). The released GOx-mediated glucose consumption not only caused a starvation status but also increased the level of cellular H2O2 and acidity, promoting Fenton reaction by FePt alloys and resulting in an increase in reactive oxygen species (ROS) accumulation in cells, which ultimately realized starving-enhanced chemodynamic process for killing tumor cells. The anticancer mechanism of pLFePt-GOx involved ROS-mediated apoptosis and ferroptosis, and glucose depletion-mediated starvation death. In the in vivo assay, the systemic delivery of pLFePt-GOx showed excellent antitumor activity with low biological toxicity and significantly enhanced T2-weighted magnetic resonance imaging (MRI) signal of the tumor, indicating that pLFePt-GOx can serve as a highly efficient theranostic tool for cancer. This work thus describes an effective, novel multi-modal cancer theranostic system.
Assuntos
Nanopartículas , Neoplasias , Ligas , Linhagem Celular Tumoral , Glucose , Humanos , Peróxido de Hidrogênio/metabolismo , Imageamento por Ressonância Magnética , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Proteínas Proto-Oncogênicas c-sis/uso terapêutico , Espécies Reativas de Oxigênio/metabolismo , Microambiente TumoralRESUMO
Copper oxide nanoparticles (CuONPs) are widely used metal oxide NPs owing to their excellent physical-chemical properties. Circulation translocation of CuONPs after inhalation leads to vascular endothelial injury. Mitochondria, an important regulatory hub for maintaining cell functions, are signaling organelles in responses to NPs-induced injury. However, how mitochondrial dynamics (fission and fusion) and mitophagy (an autophagy process to degrade damaged mitochondria) are elaborately orchestrated to maintain mitochondrial homeostasis in CuONPs-induced vascular endothelial injury is still unclear. In this study, we demonstrated that CuONPs exposure disturbed mitochondrial dynamics through oxidative stress-dependent manner in vascular endothelial cells, as evidenced by the increase of mitochondrial fission and the accumulation of fragmented mitochondria. Inhibition of mitochondrial fission with Mdivi-1 aggravated CuONPs-induced mtROS production and cell death. Furthermore, we found that mitochondrial fission led to the activation of PINK1-mediated mitophagy, and pharmacological inhibition with wortmannin, chloroquine or genetical inhibition with siRNA-mediated knockdown of PINK1 profoundly repressed mitophagy, suggesting that the protective role of mitochondrial fission and PINK1-mediated mitophagy in CuONPs-induced toxicity. Intriguingly, we identified that TAX1BP1 was the primary receptor to link the ubiquitinated mitochondria with autophagosomes, since TAX1BP1 knockdown elevated mtROS production, decreased mitochondrial clearance and aggravated CuONPs-induced cells death. More importantly, we verified that urolithin A, a mitophagy activator, promoted mtROS clearance and the removal of damaged mitochondria induced by CuONPs exposure both in vitro and in vivo. Overall, our findings indicated that modulating mitophagy may be a therapeutic strategy for pathological vascular endothelial injury caused by NPs exposure.
Assuntos
Mitofagia , Nanopartículas , Cobre/farmacologia , Células Endoteliais/metabolismo , Óxidos , Proteínas Quinases/genética , Proteínas Quinases/metabolismoRESUMO
NRF2 is the key antioxidant molecule to maintain redox homeostasis, however the intrinsic mechanisms of NRF2 activation in the context of nanoparticles (NPs) exposure remain unclear. In this study, we revealed that copper oxide NPs (CuONPs) exposure activated NRF2 pathway in vascular endothelial cells. NRF2 knockout remarkably aggravated oxidative stress, which were remarkably mitigated by ROS scavenger. We also demonstrated that KEAP1 (the negative regulator of NRF2) was not primarily involved in NRF2 activation in that KEAP1 knockdown did not significantly affect CuONPs-induced NRF2 activation. Notably, we demonstrated that autophagy promoted NRF2 activation as evidenced by that ATG5 knockout or autophagy inhibitors significantly blocked NRF2 pathway. Mechanically, CuONPs disturbed ubiquitin-proteasome pathway and consequently inhibited the proteasome-dependent degradation of NRF2. However, autophagy deficiency reciprocally promoted proteasome activity, leading to the acceleration of degradation of NRF2 via ubiquitin-proteasome pathway. In addition, the notion that the reciprocal regulation of NRF2 by autophagy and ubiquitin-proteasome was further proven in a CuONPs pulmonary exposure mice model. Together, this study uncovers a novel regulatory mechanism of NRF2 activation by protein degradation machineries in response to CuONPs exposure, which opens a novel intriguing scenario to uncover therapeutic strategies against NPs-induced vascular injury and disease.
Assuntos
Nanopartículas , Lesões do Sistema Vascular , Animais , Autofagia , Cobre , Células Endoteliais/metabolismo , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Camundongos , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , Óxidos/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Ubiquitina/metabolismoRESUMO
The promotion of neurogenesis from neural stem cells (NSCs) in the hippocampus was found to be the most fundamental and effective therapy for depression. Our previous studies proved an antidepressive effect of taurine on rats, but the exact mechanism remains unclear. In this study, CUMS model was established in rats, and NSCs were cultured in vitro to investigate the protective effect and mechanisms of taurine on neurogenesis and apoptosis in CUMS rats and glutamate-injured NSCs. The results showed that ki67-positive cells were significantly increased by taurine, while apoptosis in the DG of CUMS rats was significantly inhibited by taurine. In vitro study, cell viability, Brdu+, ß-tubulin III+, and GFAP+ cells in taurine-treated cells were significantly higher, while apoptosis rate was lower than the glutamate-treated cells. The protein expression of BDNF and its downstream pathway was upregulated by taurine administration. The results demonstrated that taurine can increase the survival, proliferation, and differentiation of NSCs; this protective effect of taurine may be due to the upregulation of BDNF/ERK/CREB signaling pathway. On the other hand, taurine can also inhibit abnormal apoptosis induced by CUMS or glutamate, the mechanism of which may be due to its antioxidative ability.
Assuntos
Fator Neurotrófico Derivado do Encéfalo , Células-Tronco Neurais , Animais , Apoptose , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Proliferação de Células , Glutamatos/metabolismo , Glutamatos/farmacologia , Hipocampo/metabolismo , Neurogênese/fisiologia , Ratos , Taurina/metabolismo , Taurina/farmacologiaRESUMO
Arsenite is a toxic metalloid that causes various adverse effects in the brain. However, the underlying mechanisms of arsenite-induced neurotoxicity remain poorly understood. In this study, both adult beclin 1+/+ and beclin 1+/- mice were employed to establish a model of chronic arsenite exposure by treating with arsenite via drinking water for 6 months. The results clearly demonstrated that exposure to arsenite profoundly caused damage to the cerebral cortex, induced autophagy and impaired autophagic flux in the cerebral cortex. Heterozygous disruption of beclin 1 in animals remarkably alleviated the neurotoxic effects of arsenite. To verify the results obtained in the animals, a permanent U251 cell line was used. After treating of cells with arsenite, similar phenomenon was also observed, showing the significant elevation in the expression levels of autophagy-related genes. Importantly, lysosomal dysfunction caused by arsenite was observed in vitro and in vivo. Either knockdown of beclin 1 in cells or heterozygous disruption of beclin 1 in animals remarkably alleviated the lysosomal dysfunction induced by arsenite. These findings indicate that downregulation of beclin 1 could restore arsenite-induced impaired autophagic flux possibly through improving lysosomal function, and correct that regulation of autophagy via beclin 1 would be an alternative approach for the treatment of arsenite neurotoxicity.
Assuntos
Arsenitos , Animais , Arsenitos/toxicidade , Autofagia , Proteína Beclina-1/genética , Proteína Beclina-1/metabolismo , Encéfalo/metabolismo , Regulação para Baixo , Lisossomos/metabolismo , CamundongosRESUMO
The aims of the study were to assess the contribution of resilience, coping style, and COVID-19 stress on the quality of life (QOL) in frontline health care workers (HCWs). The study was a cross-sectional surveyperformed among 309 HCWs in a tertiaryhospital during the outbreak of COVID-19 in China. Data were collected through an anonymous, self-rated questionnaire, including demographic data, a 10-item COVID-19 stress questionnaire, Generic QOL Inventory-74, Connor-Davidson Resilience Scale, and the Simplified Coping Style Questionnaire. Hierarchical regression was used to analyse the relationship between the study variables and the QOL. Among the 309 participants, resilience and active coping were positively correlated with the QOL (P<0.001), whereas, working in confirmed case wards, COVID-19 stress, and passive coping were negatively correlated with the QOL (P<0.001). Resilience and the active coping were negatively correlated with COVID-19 stress (P<0.001). Resilience, coping style,and COVID-19 stressaccounted for 32%, 13%, and 8% of the variance in predicting the Global QOL, respectively. In conclusion, working in confirmed COVID-19 case wards and COVID-19 stress impaired the QOL in HCWs. Psychological intervention to improve the resilience and coping style, and reduce COVID-19 stress are important in improving the QOL and mental health of HCWs.
Assuntos
COVID-19 , Resiliência Psicológica , Adaptação Psicológica , COVID-19/epidemiologia , Estudos Transversais , Pessoal de Saúde/psicologia , Humanos , Qualidade de Vida , SARS-CoV-2RESUMO
In this study, Cu-Fe bimetallic magnetic chitosan carbon aerogel catalyst (Cu-Fe@CS) was prepared by the sol-gel method to degrade Fulvic acid (FA) in Fenton-like system. Degradation experiment results showed bimetallic catalyst Cu-Fe@CS can degrade more FA than monometallic catalysts (Cu@CS and Fe@CS) due to the synergistic effect between the copper and iron. Plackett Buiman (PB) design showed that pH and temperature exhibited significant influence on FA degradation. The significant factors were optimized by Central Composite Design (CCD), the results revealed that the maximum FA removal reached 96.59% under the conditions of pH 4.07 and temperature 93.77 °C, the corresponding TOC removal reached 77.7%. The kinetic analysis implied that the reaction followed pseudo-first order kinetic with correlation coefficient (R2) = 0.9939. The Arrhenius fitting analysis revealed that Cu-Fe@CS had a lower activation energy (Ea) than Cu@CS and Fe@CS, meaning that reaction was easier to occur in Fenten-like system with Cu-Fe@CS. Catalyst still remained the higher FA and TOC removals of 96.28% and 77.33% after six runs, respectively. The FA removal was reduced by 65.53% with 12 mmol tertiary butanol (TBA) as scavenger, indicating that â¢OH played an important role in FA degradation. Finally, the catalytic degradation mechanism was proposed.
Assuntos
Carbono , Peróxido de Hidrogênio , Benzopiranos , Catálise , Cinética , Fenômenos Magnéticos , OxirreduçãoRESUMO
[Purpose] We aimed to investigate the effects of the Otago Exercise Program in older hypertensive patients with pre-frailty. [Participants and Methods] Participants were randomly divided into the (Otago Exercise Program OEP) group (n=37) and the control group (n=38). The OEP group completed the exercise step 3 times during hospitalization. For 12 weeks, the OEP group exercised at home and the control group completed daily walking activities ≥3 times per week. [Results] There were significant differences in FRAIL scale score, 10-meter gait speed, one-leg standing test results, and functional reach test results between the two groups. In addition to the above indicators, the differences in diastolic blood pressure were also statistically significant between the two groups before and after intervention. [Conclusion] The OEP can improve frailty and the ability to perform activity in older hypertensive patients with pre-frailty. Diastolic blood pressure decreases significantly after intervention.
RESUMO
Carbon black nanoparticles (CBNPs) are one of the most frequently used nanoparticles. Exposure to CBNPs during pregnancy (PrE to CBNPs) can directly induce inflammation, lung injury, and genotoxicity in dams and results in abnormalities in offspring. However, whether exposure to CBNPs during pregnancy enhances the susceptibility of offspring to environmental stimuli remains unknown. To address this issue, in this study, we intranasally treated pregnant mice with mock or CBNPs from gestational day (GD) 9 to GD18, and F1 and F2 offspring were normally obtained. By intratracheal instillation of mice with lipopolysaccharide (LPS) to trigger a classic animal model for acute lung injury, we intriguingly found that after LPS treatment, F1 and F2 offspring after exposure during pregnancy to CBNPs both exhibited more pronounced lung injury symptoms, including more degenerative histopathological changes, vascular leakage, elevated MPO activity, and activation of inflammation-related signaling transduction, compared with F1 and F2 offspring in the mock group, suggesting PrE to CBNPs would aggravate LPS-induced lung injury in offspring, and this effect was intergenerational. We also observed that PrE to CBNPs upregulated the mRNA expression of DNA methyltransferases (Dnmt) 1/3a/3b and DNA hypermethylation in both F1 and F2 offspring, which might partially account for the intergenerational effect. Together, our study demonstrates for the first time that PrE to CBNPs can enhance sensitivity to LPS in both F1 and F2 offspring, and this intergenerational effect may be related to DNA hypermethylation caused by CBNPs.