RESUMO
Ataxin-2 (Atx2) is a polyglutamine (polyQ) tract-containing RNA-binding protein, while its polyQ expansion may cause protein aggregation that is implicated in the pathogenesis of neurodegenerative diseases such as spinocerebellar ataxia type 2 (SCA2). However, the molecular mechanism underlying how Atx2 aggregation contributes to the proteinopathies remains elusive. Here, we investigated the influence of Atx2 aggregation on the assembly and functionality of cellular processing bodies (P-bodies) by using biochemical and fluorescence imaging approaches. We have revealed that polyQ-expanded (PQE) Atx2 sequesters the DEAD-box RNA helicase (DDX6), an essential component of P-bodies, into aggregates or puncta via some RNA sequences. The N-terminal like-Sm (LSm) domain of Atx2 (residues 82-184) and the C-terminal helicase domain of DDX6 are responsible for the interaction and specific sequestration. Moreover, sequestration of DDX6 may aggravate pre-mRNA mis-splicing, and interfere with the assembly of cellular P-bodies, releasing the endoribonuclease MARF1 that promotes mRNA decay and translational repression. Rescuing the DDX6 protein level can recover the assembly and functionality of P-bodies, preventing targeted mRNA from degradation. This study provides a line of evidence for sequestration of the P-body components and impairment of the P-body homeostasis in dysregulating RNA metabolism, which is implicated in the disease pathologies and a potential therapeutic target.
Assuntos
Ataxina-2 , RNA Helicases DEAD-box , Homeostase , Peptídeos , RNA Helicases DEAD-box/metabolismo , RNA Helicases DEAD-box/genética , Humanos , Ataxina-2/metabolismo , Ataxina-2/genética , Peptídeos/metabolismo , Peptídeos/química , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas/genética , Células HEK293 , Ataxias Espinocerebelares/metabolismo , Ataxias Espinocerebelares/genética , Agregados Proteicos , Splicing de RNA , Domínios Proteicos , Precursores de RNA/metabolismo , Precursores de RNA/genéticaRESUMO
Poly(A)-binding protein nuclear 1 (PABPN1) is an RNA-binding protein localized in nuclear speckles, while its alanine (Ala)-expanded variants accumulate as intranuclear aggregates in oculopharyngeal muscular dystrophy. The factors that drive PABPN1 aggregation and its cellular consequences remain largely unknown. Here, we investigated the roles of Ala stretch and poly(A) RNA in the phase transition of PABPN1 using biochemical and molecular cell biology methods. We have revealed that the Ala stretch controls its mobility in nuclear speckles, and Ala expansion leads to aggregation from the dynamic speckles. Poly(A) nucleotide is essential to the early-stage condensation that thereby facilitates speckle formation and transition to solid-like aggregates. Moreover, the PABPN1 aggregates can sequester CFIm25, a component of the pre-mRNA 3'-UTR processing complex, in an mRNA-dependent manner and consequently impair the function of CFIm25 in alternative polyadenylation. In conclusion, our study elucidates a molecular mechanism underlying PABPN1 aggregation and sequestration, which will be beneficial for understanding PABPN1 proteinopathy.
Assuntos
Distrofia Muscular Oculofaríngea , Poliadenilação , Humanos , Alanina/metabolismo , Distrofia Muscular Oculofaríngea/genética , Distrofia Muscular Oculofaríngea/metabolismo , Proteína I de Ligação a Poli(A)/genética , Proteína I de Ligação a Poli(A)/metabolismo , RNA/metabolismoRESUMO
TDP-43 (also known as TARDBP) is a nuclear splicing factor functioning in pre-mRNA processing. Its C-terminal 35-kDa fragment (TDP-35) forms inclusions or aggregates in cytoplasm, and sequesters full-length TDP-43 into the inclusions through binding with RNA. We extended the research to investigate whether TDP-35 inclusions sequester other RNA-binding proteins (RBPs) and how RNA-binding specificity has a role in this sequestration process. We have characterized T-cell restricted intracellular antigen-1 (TIA1) and other RBPs that can be sequestered into the TDP-35 inclusions through specific RNA binding, and found that this sequestration leads to the dysfunction of TIA1 in maturation of target pre-mRNA. Moreover, we directly visualized the dynamic sequestration of TDP-43 by the cytoplasmic TDP-35 inclusions by live-cell imaging. Our results demonstrate that TDP-35 sequesters some specific RBPs and this sequestration is assisted by binding with RNA in a sequence-specific manner. This study provides further evidence in supporting the hijacking hypothesis for RNA-assisted sequestration and will be beneficial to further understanding of the TDP-43 proteinopathies.
Assuntos
Esclerose Lateral Amiotrófica , Proteinopatias TDP-43 , Esclerose Lateral Amiotrófica/metabolismo , Proteínas de Ligação a DNA/metabolismo , Humanos , Corpos de Inclusão/metabolismo , RNA/genética , RNA/metabolismo , Precursores de RNA/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Proteinopatias TDP-43/metabolismoRESUMO
BACKGROUND: Oesophageal squamous cell carcinoma is one of the most commonly diagnosed carcinomas in China, and postoperative radiotherapy plays an important role in improving the prognosis of patients. Carcinomas in different locations of the oesophagus could have different patterns of lymph node metastasis after surgery. METHODS: In this multicentric retrospective study, we enrolled patients with middle thoracic oesophageal squamous cell carcinomas from 3 cancer centres, and none of the patients underwent radiotherapy before or after surgery. We analysed the lymph node recurrence rates in different stations to explore the postoperative lymphatic recurrence pattern. RESULTS: From January 1st, 2014, to December 31st, 2019, 132 patients met the criteria, and were included in this study. The lymphatic recurrence rate was 62.1%. Pathological stage (P = 0.032) and lymphadenectomy method (P = 0.006) were significant predictive factors of lymph node recurrence. The recurrence rates in the supraclavicular, upper and lower paratracheal stations of lymph nodes were 32.6%, 28.8% and 16.7%, respectively, showing a high incidence. The recurrence rate of the subcarinal node station was 9.8%, while 8.3% (upper, middle and lower) thoracic para-oesophageal nodes had recurrences. CONCLUSIONS: We recommend including the supraclavicular, upper and lower paratracheal stations of lymph nodes in the postoperative radiation field in middle thoracic oesophageal carcinomas. Subcarinal station is also potentially high-risk, while whether to include thoracic para-oesophageal or abdominal nodes needs careful consideration.
Assuntos
Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Excisão de Linfonodo , Linfonodos , Metástase Linfática , Recidiva Local de Neoplasia , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Neoplasias Esofágicas/patologia , Neoplasias Esofágicas/radioterapia , Neoplasias Esofágicas/cirurgia , Estudos Retrospectivos , Recidiva Local de Neoplasia/epidemiologia , Recidiva Local de Neoplasia/patologia , Idoso , Linfonodos/patologia , Linfonodos/cirurgia , Carcinoma de Células Escamosas do Esôfago/cirurgia , Carcinoma de Células Escamosas do Esôfago/patologia , Carcinoma de Células Escamosas do Esôfago/radioterapia , Esofagectomia , Adulto , Prognóstico , China/epidemiologia , Estadiamento de NeoplasiasRESUMO
Anlotinib is an antiangiogenic drug that shows good efficacy and safety in patients with advanced non-small-cell lung cancer (NSCLC). This study aimed to explore the efficacy and safety of anlotinib for consolidation therapy in patients with stage III locally advanced, unresectable NSCLC after concurrent chemoradiotherapy (cCRT). This was a randomized, parallel-controlled, open-label, multicenter, phase II trial of patients with unresectable/nonoperated NSCLC treated with cCRT. The participants were randomized 2:1 to the anlotinib or control group. The primary endpoint was progression-free survival (PFS). The secondary endpoints were the disease control rate (DCR) and overall survival. This study was terminated early due to poor recruitment. Nine and two participants were randomly assigned to the anlotinib and control groups, respectively. One participant in the control group was excluded due to taking prohibited medications before the first efficacy evaluation. In the anlotinib group, the median age was 63 (range, 37-74) years. Two participants achieved partial response, six stable disease, and one progressive disease as best response. The DCR was 88.9%. The median PFS was 11.5 months, and the 12-month PFS rate was 33.9%. All related adverse events were grade 1 or 2. Two participants had a dose adjustment during the study. The evaluable data suggest that anlotinib alone was effective and tolerable in consolidation therapy after cCRT in patients with stage III unresectable NSCLC. The results need to be confirmed by a large-sample trial. This clinical trial was registered on www.clinicaltrials.gov (NCT03743129). Registration date: 6 September 2018.
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Quimiorradioterapia , Indóis , Neoplasias Pulmonares , Quinolinas , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/terapia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/terapia , Pessoa de Meia-Idade , Masculino , Feminino , Indóis/administração & dosagem , Indóis/uso terapêutico , Indóis/efeitos adversos , Idoso , Quinolinas/uso terapêutico , Quinolinas/administração & dosagem , Quinolinas/efeitos adversos , Quimiorradioterapia/métodos , Adulto , Quimioterapia de Consolidação/métodos , Estadiamento de Neoplasias , Intervalo Livre de Progressão , Taxa de SobrevidaRESUMO
BACKGROUND: Immunotherapy has made significant advances in the treatment of extensive-stage small-cell lung cancer (ES-SCLC), but data in combination with radiotherapy are scarce. This study aims to assess the safety and efficacy of chemoimmunotherapy combined with thoracic radiotherapy in patients with ES-SCLC. METHODS: This single-center retrospective study analyzed patients with ES-SCLC who received standard platinum-etoposide chemotherapy combined with atezolizumab or durvalumab immunotherapy as induction treatment, followed by consolidative thoracic radiotherapy (CTRT) before disease progression in the first-line setting. Adverse events during radiotherapy with or without maintenance immunotherapy and survival outcomes were assessed. RESULTS: Between December 2019 and November 2021, 36 patients with ES-SCLC were identified to have received such treatment modality at one hospital. The number of metastatic sites at diagnosis was 1-4. The biological effective dose of CTRT ranged from 52 to 113 Gy. Only two patients (6%) developed grade 3 toxic effect of thrombocytopenia, but none experienced grade 4 or 5 toxicity. Four patients developed immune-related pneumonitis during the induction treatment period but successfully completed later CTRT. The rate of radiation-related pneumonitis was 8% with grades 1-2 and well tolerated. The median progression-free survival (PFS) was 12.8 months, but the median overall survival (OS) was not determined. The estimated 1-year OS was 80.2% and 1-year PFS was 53.4%. CONCLUSIONS: Immunotherapy combined with CTRT for ES-SCLC is safe and has ample survival benefit.
Assuntos
Imunoterapia , Neoplasias Pulmonares , Carcinoma de Pequenas Células do Pulmão , Humanos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Cisplatino , Etoposídeo , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/radioterapia , Platina/uso terapêutico , Estudos Retrospectivos , Carcinoma de Pequenas Células do Pulmão/tratamento farmacológico , Carcinoma de Pequenas Células do Pulmão/radioterapiaRESUMO
Pathological TDP-43 aggregation is characteristic of several neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD-TDP); however, how TDP-43 aggregation and function are regulated remain poorly understood. Here, we show that O-GlcNAc transferase OGT-mediated O-GlcNAcylation of TDP-43 suppresses ALS-associated proteinopathies and promotes TDP-43's splicing function. Biochemical and cell-based assays indicate that OGT's catalytic activity suppresses TDP-43 aggregation and hyperphosphorylation, whereas abolishment of TDP-43 O-GlcNAcylation impairs its RNA splicing activity. We further show that TDP-43 mutations in the O-GlcNAcylation sites improve locomotion defects of larvae and adult flies and extend adult life spans, following TDP-43 overexpression in Drosophila motor neurons. We finally demonstrate that O-GlcNAcylation of TDP-43 promotes proper splicing of many mRNAs, including STMN2, which is required for normal axonal outgrowth and regeneration. Our findings suggest that O-GlcNAcylation might be a target for the treatment of TDP-43-linked pathogenesis.
Assuntos
Esclerose Lateral Amiotrófica , Demência Frontotemporal , Esclerose Lateral Amiotrófica/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Humanos , Splicing de RNA , RNA Mensageiro/genéticaRESUMO
Nine polyglutamine (polyQ) proteins have already been identified that are considered to be associated with the pathologies of neurodegenerative disorders called polyQ diseases, but whether these polyQ proteins mutually interact and synergize in proteinopathies remains to be elucidated. In this study, 4 polyQ-containing proteins, androgen receptor (AR), ataxin-7 (Atx7), huntingtin (Htt) and ataxin-3 (Atx3), are used as model molecules to investigate their heterologous coaggregation and consequent impact on cellular proteostasis. Our data indicate that the N-terminal fragment of polyQ-expanded (PQE) Atx7 or Htt can coaggregate with and sequester AR and Atx3 into insoluble aggregates or inclusions through their respective polyQ tracts. In vitro coprecipitation and NMR titration experiments suggest that this specific coaggregation depends on polyQ lengths and is probably mediated by polyQ-tract interactions. Luciferase reporter assay shows that these coaggregation and sequestration effects can deplete the cellular availability of AR and consequently impair its transactivation function. This study provides valid evidence supporting the viewpoint that coaggregation of polyQ proteins is mediated by polyQ-tract interactions and benefits our understanding of the molecular mechanism underlying the accumulation of different polyQ proteins in inclusions and their copathological causes of polyQ diseases.
Assuntos
Doenças Neurodegenerativas , Proteostase , Humanos , Peptídeos/química , Proteína Huntingtina/genética , Proteína Huntingtina/metabolismo , Ataxina-3/genética , Ataxina-3/metabolismoRESUMO
Vehicle Ad-hoc network (VANET) can provide technical support and solutions for the construction of intelligent and efficient transportation systems, and the routing protocol directly affects the efficiency of VANET. The rapid movement of nodes and uneven density distribution affect the routing stability and data transmission efficiency in VANET. To improve the local optimality and routing loops of the path-aware greedy perimeter stateless routing protocol (PA-GPSR) in urban sparse networks, a weight-based path-aware greedy perimeter stateless routing protocol (W-PAGPSR) is proposed. The protocol is divided into two stages. Firstly, in the routing establishment stage, the node distance, reliable node density, cumulative communication duration, and node movement direction are integrated to indicate the communication reliability of the node, and the next hop node is selected using the weight greedy forwarding strategy to achieve reliable transmission of data packets. Secondly, in the routing maintenance stage, based on the data packet delivery angle and reliable node density, the next hop node is selected for forwarding using the weight perimeter forwarding strategy to achieve routing repair. The simulation results show that compared to the greedy peripheral stateless routing protocol (GPSR), for the maximum distance-minimum angle greedy peripheral stateless routing (MM-GPSR) and PA-GPSR protocols, the packet loss rate of the protocol is reduced by an average of 24.47%, 25.02%, and 14.12%, respectively; the average end-to-end delay is reduced by an average of 48.34%, 79.96%, and 21.45%, respectively; and the network throughput is increased by an average of 47.68%, 58.39%, and 20.33%, respectively. This protocol improves network throughput while reducing the average end-to-end delay and packet loss rate.
Assuntos
Algoritmos , Tecnologia sem Fio , Reprodutibilidade dos Testes , Simulação por Computador , Redes de Comunicação de ComputadoresRESUMO
The use of seawater as a substitute for pure water as supplemental moisture raises questions about its effect on the physicochemical properties of hydrochar. Therefore, this study aimed to investigate the feasibility of using seawater as supplemental moisture by comparing the physicochemical properties of products obtained through Co-hydrothermal carbonization of chicken manure and cornstalk under seawater and deionized water conditions. By varying the HTC temperature and blending ratios of CM and CS to investigate comprehensively the effect of seawater. Results indicated that the hydrochar yield experienced a variation from 54.54% to 57.40%, while the IC value changed from 7.69% to 8.46% as the ratio of CM:CS shifted from 3:1 to 1:3 under seawater conditions. The higher heating value of the hydrochars obtained under seawater conditions was lower than those obtained under deionized water conditions. This suggests that seawater conditions promote the hydrolysis reaction of organic solid waste. Furthermore, it was observed that when no lignin hydrolysis reaction occurred, seawater conditions had no discernible effect on the fuel quality of the hydrochar. However, at an HTC temperature of 250 °C, the fuel quality of the hydrochar obtained under seawater conditions was notably inferior to that of the hydrochar obtained under deionized water. Thus, an HTC temperature lower than 250 °C is necessary for the hydrothermal carbonization of organic solid waste under seawater conditions. Moreover, the relative content of surface -C-(C, H)/CC of the hydrochar obtained under seawater conditions was lower than that obtained under deionized water conditions, indicating that the hydrochar had a low degree of aromatization. Additionally, there was a significant increase in the immobilized Mg atoms in the hydrochar under seawater conditions, which affected the hydrochar yield and higher heating value of the hydrochar. This research presents a theoretical foundation for preparing solid fuels and materials using hydrothermal carbonization of saltwater as supplemental moisture.
Assuntos
Carbono , Esterco , Animais , Galinhas , Resíduos Sólidos , Água do Mar , Água , TemperaturaRESUMO
Cervical cancer is a common gynecological malignancy afflicting women all over the world. Ginsenoside Rh2 (GRh2), especially 20(S)-GRh2, is a biologically active component in the natural plant ginseng, which can exhibit anticancer effects. Here, we aimed to investigate the effect of 20(S)-GRh2 on cervical cancer and elucidate the underlying mechanism through RNA-seq. In this study, the CCK-8 assay showed that 20(S)-GRh2 inhibited HeLa cell viability in a time- and dose-dependent manner. Caspase 3 activity and Annexin V staining results showed that 20(S)-GRh2 induced apoptosis of HeLa cells. Gene function enrichment analysis revealed that the biological process gene ontology (GO) terms were associated with the apoptotic signaling pathway. Biological process GO terms' similarity network indicated that apoptosis might be from endoplasmic reticulum stress (ERs). Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed that 20(S)-GRh2 primarily modulates apoptosis pathway genes. Combined protein-protein interaction network, hub gene screening, and qPCR validation data showed that ERs-related genes (ATF4 and DDIT3) and the downstream apoptotic genes (JUN, FOS, BBC3, and PMAIP1) were potential novel targets of 20(S)-GRh2-inducing cervical cancer cell apoptosis. Differential transcript usage analysis indicated that DDIT3 is also a differential transcript and its usage of the isoform (ENST00000552740.5) was reduced by 20(S)-GRh2. Molecular docking suggested that 20(S)-GRh2 binds to the targets (ATF4, DDIT3, JUN, FOS, BBC3, and PMAIP1) with high affinity. In conclusion, our findings indicated that 20(S)-GRh2 might promote ERs-related apoptosis of cervical cancer cells by regulating the DDIT3-based targets' signal pathway. The role of 20(S)-GRh2 at the transcriptome level provides novel targets and evidence for the treatment of cervical cancer.
Assuntos
Estresse do Retículo Endoplasmático , Neoplasias do Colo do Útero , Feminino , Humanos , Células HeLa , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/genética , Simulação de Acoplamento Molecular , Apoptose , Proteínas Reguladoras de Apoptose , Expressão GênicaRESUMO
Ubiquitin-specific protease 19 (USP19) is a member of the deubiquitinating (DUB) enzymes that catalyze removing the ubiquitin signals from target proteins. Our previous research has demonstrated that USP19 up-regulates the protein level and aggregation of polyQ-expanded huntingtin through the involvement of heat shock protein 90 (HSP90). Here, we present solution structures of the CS1, CS2 and UbL domains of USP19 and structural insights into their domain interactions. We found that the tandem CS domains fold back to interact with the C-terminal USP domain (USPD) intra-molecularly that leads to inhibition of the catalytic core of USP19, especially CS1 interacts with the embedded UbL domain and CS2 does with the CH2 catalytic core. Moreover, CS2 specifically interacts with the NBD domain of HSP90, which can activate the DUB enzyme. A mechanism of auto-inhibition of USP19 and activation by HSP90 is proposed, on which USP19 modulates the protein level of polyQ-expanded huntingtin in cells. This study provides structural and mechanistic insights into the modulation of protein level and aggregation by USP19 with the assistance of HSP90.
Assuntos
Endopeptidases/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Enzimas Desubiquitinantes/metabolismo , Humanos , Proteína Huntingtina/metabolismo , Peptídeos/metabolismo , Ubiquitina/metabolismo , UbiquitinaçãoRESUMO
TDP-43 is a primary pathological hallmark protein of amyotrophic lateral sclerosis and frontotemporal lobar degeneration, which may exist in the form of amyloid inclusions in the cells of patients. In addition to serving as a biomarker for these diseases, TDP-43 can also directly trigger neurodegeneration. We previously determined the amyloidogenic core region of TDP-43 (residues 311-360) and showed by solution NMR that this region includes two α-helices [(321-330) and (335-343)] in solution. We suggested that the helix-to-sheet structural transformation initiates TDP-43 aggregation. In the present study, X-ray diffraction shows that TDP-43 (311-360) aggregates adopt a cross-ß structure. Thioredoxin (Trx)-fused TDP-43 (311-360) can undergo liquid-liquid phase separation (LLPS) before fibrillation, suggesting that phase separation is an intermediate step before amyloid formation. Solid-state NMR (SSNMR), carried out to elucidate the structural changes of TDP-43 (311-360) at the atomic level, indicates five ß-strands of the amyloids formed, with the major two ß-strands contributed by the first helical region in the solution structure. The NMR evidence is also in support of the fibril having a parallel in-register conformation, implying a mechanism in which the helix-helix interactions in LLPS are converted into ß-strand parallel lateral association upon fibrillation. Our studies have assigned many key interresidue interactions that contribute to the stability of the fibril, including F316 with I318 and Q327 and W334 with A325, A326, A329, and S332. SSNMR with 1H detection reveals a unique close interaction between the indole Nε1-Hε1 of W334 and the side-chain carbonyl of Q343. This interaction could be a very important factor in initiating TDP-43 (311-360) folding/misfolding in LLPS.
Assuntos
Proteínas Amiloidogênicas/metabolismo , Proteínas de Ligação a DNA/metabolismo , Fragmentos de Peptídeos/metabolismo , Sequência de Aminoácidos , Proteínas Amiloidogênicas/química , Proteínas de Ligação a DNA/química , Humanos , Ressonância Magnética Nuclear Biomolecular , Fragmentos de Peptídeos/química , Transição de Fase , Conformação Proteica , Multimerização ProteicaRESUMO
In the present work, a novel microchannel device was developed and used for the preparation of core-shell microspheres combining with a dextran/poly(ethylene glycol) diacrylate (DEX/PEGDA) aqueous two-phase system. Silica@silica core-shell microspheres were prepared as a model material. Silica@silica core-shell microspheres with different sizes of cores and thicknesses of shells were prepared by using different flowrate ratios of DEX/silica and PEGDA/silica aqueous solutions. The content of colloidal silica and the calcination temperature have a significant effect on the texture properties of the prepared core-shell microspheres. The surface area decreased from 199 to 177 m2/g with an increase in the colloidal silica content from 30 to 60 wt %. For a specific colloidal silica content (50 wt %), with the increase in calcination temperature from room temperature to 650 °C, the total pore volume went through a maximum of 0.7 cm3 g-1 with a surface area of 178 m2 g-1 and pore size of 7.32 nm at 450 °C. Due to the accumulation of metal nanoparticles in DEX, different metal nanoparticles (Ni and Pd) were successfully introduced into the core of the core-shell microspheres for the preparation of silica/metal nanoparticles@silica core-shell microsphere catalysts. The catalysts showed similar catalytic performance as the metal nanoparticles for hydrogenation of 4-nitrophenol with a conversion higher than 95%. However, the core-shell microsphere catalyst is much easier to recover. The reuse experiments indicated that the core-shell catalyst has high stability.
RESUMO
Complex emulsions are used to fabricate new morphologies of multiple Janus droplets, evolving from non-engulfing to complete engulfing core/shell configuration. The produced droplets contain an aqueous phase of dextran (DEX) solution and an oil phase, which is mixed with ethoxylated trimethylolpropane triacrylate (ETPTA) and poly(ethylene glycol) diacrylate (PEGDA). The PEGDA in the oil phase is transferred into the aqueous phase to form complex morphologies due to the phase separation of PEGDA and DEX. The effects are investigated including the ratio of oil to aqueous phase, the content of initial PEGDA, DEX and surfactants, and the type of surfactants. DEX/PEGDA-ETPTA core/shell-single phase Janus droplets are formed with an increasing engulfed oil droplet into the aqueous droplet while the ratio of oil to aqueous phase increases or the initial PEGDA content increases. The high DEX content leads to the DEX-PEGDA-ETPTA doublet Janus. The use of surfactants polyglycerol polyricinoleate (PGPR) and Span 80 results in the formation of DEX/PEGDA/ETPTA single core/double shell and DEX/PEGDA-ETPTA core/shell-single phase Janus droplets, respectively. These complex emulsions are utilized to fabricate solid particles of complex shapes. This method contributes to new material design underpinned by mass transfer and phase separation, which can be extended to other complex emulsion systems.
RESUMO
The components of ubiquitin (Ub)-proteasome system, such as Ub, Ub adaptors, or proteasome subunits, are commonly accumulated with the aggregated proteins in inclusions, but how protein aggregates sequester Ub-related proteins remains elusive. Using N-terminal huntingtin (Htt-N552) and ataxin (Atx)-3 as model proteins, we investigated the molecular mechanism underlying sequestration of Ub adaptors by polyQ-expanded proteins. We found that polyQ-expanded Htt-N552 and Atx-3 sequester endogenous Ub adaptors, human RAD23 homolog B (hHR23B) and ubiquilin (UBQLN)-2, into inclusions. This sequestration effect is dependent on the UBA domains of Ub adaptors and the conjugated Ub of the aggregated proteins. Moreover, polyQ-expanded Htt-N552 and Atx-3 reduce the protein level of xeroderma pigmentosum group C (XPC) by sequestration of hHR23B, suggesting that this process may cut down the available quantity of hHR23B and thus affect its normal function in stabilizing XPC. Our findings demonstrate that polyQ-expanded proteins sequester Ub adaptors or other Ub-related proteins into aggregates or inclusions through ubiquitination of the pathogenic proteins. This study may also provide a common mechanism for the formation of Ub-positive inclusions in cells.-Yang, H., Yue, H.-W., He, W.-T., Hong, J.-Y., Jiang, L.-L., Hu, H.-Y. PolyQ-expanded huntingtin and ataxin-3 sequester ubiquitin adaptors hHR23B and UBQLN2 into aggregates via conjugated ubiquitin.
Assuntos
Ataxina-3/metabolismo , Proteínas de Ciclo Celular/metabolismo , Enzimas Reparadoras do DNA/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteína Huntingtina/metabolismo , Peptídeos/metabolismo , Proteínas Repressoras/metabolismo , Ubiquitinas/metabolismo , Proteínas Adaptadoras de Transdução de Sinal , Ataxina-3/genética , Proteínas Relacionadas à Autofagia , Proteínas de Ciclo Celular/genética , Enzimas Reparadoras do DNA/genética , Proteínas de Ligação a DNA/genética , Células HEK293 , Humanos , Proteína Huntingtina/genética , Peptídeos/genética , Domínios Proteicos , Estabilidade Proteica , Proteínas Repressoras/genética , Ubiquitinas/genéticaRESUMO
Human ataxin 7 (Atx7) is a component of the deubiquitination module (DUBm) in the Spt-Ada-Gcn5-acetyltransferase (SAGA) complex for transcriptional regulation, and expansion of its polyglutamine (polyQ) tract leads to spinocerebellar ataxia type 7. However, how polyQ expansion of Atx7 affects DUBm function remains elusive. We investigated the effects of polyQ-expanded Atx7 on ubiquitin-specific protease (USP22), an interacting partner of Atx7 functioning in deubiquitination of histone H2B. The results showed that the inclusions or aggregates formed by polyQ-expanded Atx7 specifically sequester USP22 through their interactions mediated by the N-terminal zinc finger domain of Atx7. The mutation of the zinc finger domain in Atx7 that disrupts its interaction with USP22 dramatically abolishes sequestration of USP22. Moreover, polyQ expansion of Atx7 decreases the deubiquitinating activity of USP22 and, consequently, increases the level of monoubiquitinated H2B. Therefore, we propose that polyQ-expanded Atx7 forms insoluble aggregates that sequester USP22 into a catalytically inactive state, and then the impaired DUBm loses the function to deubiquitinate monoubiquitinated histone H2B or H2A. This may result in dysfunction of the SAGA complex and transcriptional dysregulation in spinocerebellar ataxia type 7 disease.
Assuntos
Ataxina-7/metabolismo , Histona Acetiltransferases/metabolismo , Complexos Multienzimáticos/metabolismo , Tioléster Hidrolases/metabolismo , Ataxina-7/genética , Sítios de Ligação/genética , Western Blotting , Células HEK293 , Células HeLa , Histonas/metabolismo , Humanos , Microscopia de Fluorescência , Mutação , Peptídeos/genética , Agregados Proteicos , Ligação Proteica , Ataxias Espinocerebelares/genética , Ataxias Espinocerebelares/metabolismo , Tioléster Hidrolases/genética , Expansão das Repetições de Trinucleotídeos/genética , Ubiquitina Tiolesterase , Ubiquitinação , Dedos de Zinco/genéticaRESUMO
TDP-43 (TAR DNA-binding protein of 43 kDa) is a major deposited protein in amyotrophic lateral sclerosis and frontotemporal dementia with ubiquitin. A great number of genetic mutations identified in the flexible C-terminal region are associated with disease pathologies. We investigated the molecular determinants of TDP-43 aggregation and its underlying mechanisms. We identified a hydrophobic patch (residues 318-343) as the amyloidogenic core essential for TDP-43 aggregation. Biophysical studies demonstrated that the homologous peptide formed a helix-turn-helix structure in solution, whereas it underwent structural transformation from an α-helix to a ß-sheet during aggregation. Mutation or deletion of this core region significantly reduced the aggregation and cytoplasmic inclusions of full-length TDP-43 (or TDP-35 fragment) in cells. Thus, structural transformation of the amyloidogenic core initiates the aggregation and cytoplasmic inclusion formation of TDP-43. This particular core region provides a potential therapeutic target to design small-molecule compounds for mitigating TDP-43 proteinopathies.
Assuntos
Amiloide/metabolismo , Proteínas de Ligação a DNA/metabolismo , Corpos de Inclusão/metabolismo , Amiloide/genética , Animais , Caenorhabditis elegans , Proteínas de Ligação a DNA/genética , Desenho de Fármacos , Células HeLa , Sequências Hélice-Volta-Hélice , Humanos , Interações Hidrofóbicas e Hidrofílicas , Corpos de Inclusão/genética , Corpos de Inclusão/patologia , Estrutura Terciária de Proteína , Proteinopatias TDP-43/tratamento farmacológico , Proteinopatias TDP-43/genética , Proteinopatias TDP-43/metabolismo , Proteinopatias TDP-43/patologiaRESUMO
This study aims to analyze the mediating role of employee engagement and the green work environment in the relationship between motivation and the performance of logistics company employees in Jakarta, Indonesia. Employing a causal quantitative research approach, we distributed 222 questionnaires among logistics employees from four surrounding cities in Jakarta, namely Bogor, Depok, Tangerang, and Bekasi. These questionnaires were adapted from past studies. The data were processed using Structural Equation Modeling (SEM) with Partial Least Squares. The results showed that employee performance in logistics companies was positively and significantly influenced by motivation. Furthermore, a green work environment and employee engagement were found to significantly mediate the relationship between motivation and performance. These findings underscore the importance of a green work environment and employee engagement in enhancing motivation and performance in logistics companies. The study implies that employee performance in logistics companies can be elevated through the provision of a green work environment, alongside fostering employee motivation and engagement.
RESUMO
In brain metastases, radiation necrosis (RN) is a complication that arises after single or multiple fractionated stereotactic radiosurgery (SRS/FSRS), which is challenging to distinguish from local recurrence (LR). Studies have shown increased RN incidence rates in non-small cell lung cancer (NSCLC) patients with oncogenic driver mutations (ODMs) or receiving tyrosine kinase inhibitors (TKIs). This study investigated enlarging brain lesions following SRS/FSRS, for which additional surgeries were performed to distinguish between RN and LR. We investigated seven NSCLC patients with ODMs undergoing SRS/FSRS for BM and undergoing surgery for suspicion of LR on MRI imaging. Descriptive statistics were performed. Among the seven patients, six were EGFR+, while one was ALK+. The median irradiation dose was 30 Gy (range, 20-35 Gy). The median time to develop RN after SRS/FSRS was 11.1 months (range: 6.3-31.2 months). Moreover, gradually enlarging lesions were found in all patients after 6 months post-SRS/FSR. Brain radiation necrosis was pathologically confirmed in all the patients. RN should be suspected in NSCLC patients when lesions keep enlarging after 6 months post-SRS/FSRS, especially for patients with ODMs and receiving TKIs. Further, this case series indicates that further dose reduction might be necessary to avoid RN for such patients.