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Arrestin proteins bind to active, phosphorylated G-protein-coupled receptors (GPCRs), thereby preventing G-protein coupling, triggering receptor internalization and affecting various downstream signalling pathways1,2. Although there is a wealth of structural information detailing the interactions between GPCRs and G proteins, less is known about how arrestins engage GPCRs. Here we report a cryo-electron microscopy structure of full-length human neurotensin receptor 1 (NTSR1) in complex with truncated human ß-arrestin 1 (ßarr1(ΔCT)). We find that phosphorylation of NTSR1 is critical for the formation of a stable complex with ßarr1(ΔCT), and identify phosphorylated sites in both the third intracellular loop and the C terminus that may promote this interaction. In addition, we observe a phosphatidylinositol-4,5-bisphosphate molecule forming a bridge between the membrane side of NTSR1 transmembrane segments 1 and 4 and the C-lobe of arrestin. Compared with a structure of a rhodopsin-arrestin-1 complex, in our structure arrestin is rotated by approximately 85° relative to the receptor. These findings highlight both conserved aspects and plasticity among arrestin-receptor interactions.
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Modelos Moleculares , Receptores de Neurotensina/química , beta-Arrestina 1/química , Microscopia Crioeletrônica , Humanos , Fosforilação , Estabilidade Proteica , Estrutura Quaternária de Proteína , Receptores de Neurotensina/metabolismo , beta-Arrestina 1/metabolismoRESUMO
The distal lung contains terminal bronchioles and alveoli that facilitate gas exchange. Three-dimensional in vitro human distal lung culture systems would strongly facilitate the investigation of pathologies such as interstitial lung disease, cancer and coronavirus disease 2019 (COVID-19) pneumonia caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Here we describe the development of a long-term feeder-free, chemically defined culture system for distal lung progenitors as organoids derived from single adult human alveolar epithelial type II (AT2) or KRT5+ basal cells. AT2 organoids were able to differentiate into AT1 cells, and basal cell organoids developed lumens lined with differentiated club and ciliated cells. Single-cell analysis of KRT5+ cells in basal organoids revealed a distinct population of ITGA6+ITGB4+ mitotic cells, whose offspring further segregated into a TNFRSF12Ahi subfraction that comprised about ten per cent of KRT5+ basal cells. This subpopulation formed clusters within terminal bronchioles and exhibited enriched clonogenic organoid growth activity. We created distal lung organoids with apical-out polarity to present ACE2 on the exposed external surface, facilitating infection of AT2 and basal cultures with SARS-CoV-2 and identifying club cells as a target population. This long-term, feeder-free culture of human distal lung organoids, coupled with single-cell analysis, identifies functional heterogeneity among basal cells and establishes a facile in vitro organoid model of human distal lung infections, including COVID-19-associated pneumonia.
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COVID-19/virologia , Pulmão/citologia , Modelos Biológicos , Organoides/citologia , Organoides/virologia , SARS-CoV-2/fisiologia , Técnicas de Cultura de Tecidos , Células Epiteliais Alveolares/citologia , Células Epiteliais Alveolares/metabolismo , Células Epiteliais Alveolares/virologia , COVID-19/metabolismo , COVID-19/patologia , Diferenciação Celular , Divisão Celular , Células Clonais/citologia , Células Clonais/metabolismo , Células Clonais/virologia , Humanos , Técnicas In Vitro , Vírus da Influenza A Subtipo H1N1/crescimento & desenvolvimento , Vírus da Influenza A Subtipo H1N1/fisiologia , Integrina alfa6/análise , Integrina beta4/análise , Queratina-5/análise , Organoides/metabolismo , Pneumonia Viral/metabolismo , Pneumonia Viral/patologia , Pneumonia Viral/virologia , SARS-CoV-2/crescimento & desenvolvimento , Análise de Célula Única , Receptor de TWEAK/análiseRESUMO
Thyroperoxidase (TPO) is central in thyroid hormone (TH) synthesis and inhibition can lead to TH deficiency. Many chemicals can inhibit TPO activity in vitro, but how this may manifest in the developing thyroid gland at the molecular level is unclear. Here, we characterized the thyroid gland transcriptome of male rats developmentally exposed to the in vitro TPO-inhibitors amitrole, 2-mercaptobenzimidazole (MBI), or cyanamide by use of Bulk-RNA-Barcoding (BRB) and sequencing. Amitrole exposure caused TH deficiency and 149 differentially expressed genes in the thyroid gland. The effects indicated an activated and growing thyroid gland. MBI caused intermittent changes to serum TH concentrations in a previous study and this was accompanied by 60 differentially expressed genes in the present study. More than half of these were also affected by amitrole, indicating that they could be early effect biomarkers of developmental TH system disruption due to TPO inhibition. Further work to validate the signature is needed, including assessment of substance independency and applicability domain.
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Iodeto Peroxidase , Glândula Tireoide , Transcriptoma , Animais , Glândula Tireoide/metabolismo , Glândula Tireoide/efeitos dos fármacos , Ratos , Iodeto Peroxidase/genética , Iodeto Peroxidase/metabolismo , Masculino , Transcriptoma/efeitos dos fármacos , Amitrol (Herbicida)/farmacologia , Inibidores Enzimáticos/farmacologia , Benzimidazóis/farmacologiaRESUMO
Ultrathin topological insulator membranes are building blocks of exotic quantum matter. However, traditional epitaxy of these materials does not facilitate stacking in arbitrary orders, while mechanical exfoliation from bulk crystals is also challenging due to the non-negligible interlayer coupling therein. Here we liberate millimeter-scale films of the topological insulator Bi2Se3, grown by molecular beam epitaxy, down to 3 quintuple layers. We characterize the preservation of the topological surface states and quantum well states in transferred Bi2Se3 films using angle-resolved photoemission spectroscopy. Leveraging the photon-energy-dependent surface sensitivity, the photoemission spectra taken with 6 and 21.2 eV photons reveal a transfer-induced migration of the topological surface states from the top to the inner layers. By establishing clear electronic structures of the transferred films and unveiling the wave function relocation of the topological surface states, our work lays the physics foundation crucial for the future fabrication of artificially stacked topological materials with single-layer precision.
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PURPOSE OF REVIEW: This review summarizes recent advances in developing targeted diagnostics for venous thromboembolism (VTE) and unaddressed knowledge gaps in patient management. Without addressing these critical data needs, the morbidity in VTE patients will persist. RECENT FINDINGS: Recent studies investigating plasma protein profiles in VTE patients have identified key diagnostic targets to address the currently unmet need for low-cost, confirmatory, point-of-care VTE diagnostics. These studies and a growing body of evidence from animal model studies have revealed the importance of inflammatory and vascular pathology in driving VTE, which are currently unaddressed targets for VTE therapy. To enhance the translation of preclinical animal studies, clinical quantification of thrombus burden and comparative component analyses between modeled VTE and clinical VTE are necessary. SUMMARY: Lead candidates from protein profiling of VTE patients' plasma offer a promising outlook in developing low cost, confirmatory, point-of-care testing for VTE. Additionally, addressing the critical knowledge gap of quantitatively measuring clinical thrombi will allow for an array of benefits in VTE management and informing the translatability of experimental therapeutics.
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Tromboembolia Venosa , Trombose Venosa , Humanos , Tromboembolia Venosa/diagnóstico , Tromboembolia Venosa/tratamento farmacológico , Anticoagulantes/uso terapêuticoRESUMO
The alignment of a receiver with a pencil beam in a wireless optical power transfer (WOPT) system employing a resonance beam charging (RBC) technology limits the establishment of a resonance cavity. Accurate tracking necessitates precise and dependable monitoring, which requires the exact placement of transmitting and receiving devices. Herein, we present a concept of a two-dimensional (2D) beam steering mechanism for RBC-based WOPT systems utilizing dispersed laser beams. The proposed approach allows a significant improvement, including reduction of scanning times and minimization of errors, in relation to conventional pencil-beam-based systems. Experimental results reveal 14% faster acquisition time efficiency, an 18% improvement in pointing accuracy, and a 24% enhancement in tracking accuracy. These results establish the prerequisites for the implementation of dispersed beam steering in the RBC-based WOPT system. This capability empowers the system to charge movable devices and Internet of Things devices consistently in smart factories.
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BACKGROUND: Mycoplasma genitalium causes a sexually transmitted infection and is also emerging as an important antimicrobial resistant pathogen. Data on M. genitalium infections among men who have sex with men (MSM) in low-resource settings are sparse. METHODS: From January to December 2022, participants in an HIV pre-exposure prophylaxis (PrEP) program in Hanoi, Vietnam were enrolled into the study. Demographic, behavioral, and clinical characteristics were collected. Self-collected urine, rectal, and pharyngeal specimens were tested for M. genitalium using the Alinity m STI Assay (Abbott Molecular, USA). Univariate and multivariate logistic regression were performed to assess for factors associated with infections. RESULTS: Among 477 participants, the median age was 25.3 years (21.7-29.6) and 92.2% (n = 440) identified as MSM; 48.6% had ≥2 sex partners and 38.1% reported condomless anal sex in the prior month. The overall prevalence of M. genitalium infection was 10.9% (52/477); 7.3% (34/464) rectal, 3.2% (15/476) urethral, and 1.9% (9/476) pharyngeal. Infections were asymptomatic in 71.2% (37/52). Among those with M. genitalium, 30.7% (16/52) were co-infected with either N. gonorrhoeae or C. trachomatis. Among those reporting rectal (n = 51) or urethral (n = 35) symptoms, but without C. trachomatis or N. gonorrhoeae co-infections, five (9.8%) had rectal infections and one (2.9%) had urethral infection. Participants with M. genitalium were more likely to be asymptomatic than participants without M. genitalium (aOR 1.93; 95% CI 1.01-3.71). CONCLUSIONS: M. genitalium infections were common among primarily MSM engaged in an HIV PrEP program in Vietnam. The prevalence was highest in rectal specimens and nearly three quarters of M. genitalium infections were asymptomatic. Testing for M. genitalium infections among those with symptoms is important to enable pathogen-directed therapy. Additional research on antimicrobial resistance and treatment strategies for M. genitalium in low-resource settings is needed.
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OBJECTIVES: The associations between the neutrophil-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) with the responses of non-small cell lung cancer (NSCLC) patients receiving immune checkpoint inhibitors (ICI) and the NLR/PLR predictive potential were evaluated via meta-analysis. METHODS: A systematic review was conducted using the PubMed, Embase, and The Cochrane Library databases until October 2021. The relationship between NLR/PLR and overall survival (OS) and progression-free survival (PFS) was evaluated using pooled hazard ratios (HR). The relationship between NLR/PLR and overall response rate (ORR) and disease control rate (DCR) was assessed via pooled odds ratios (OR). Heterogeneity between studies, publication bias, subgroup and sensitivity analyses, trim and fill meta-analysis, and the contour-enhanced funnel plot were performed using the R software. RESULTS: A total of 44 (out of 875) studies met the eligibility criteria, providing a sample size of 4597 patients. Patients with a high NLR were statistically significantly associated with worse outcomes, including OS (pooled HR = 2.44; P < 0.001), PFS (pooled HR = 2.06; P < 0.001), DCR (pooled OR = 0.71; P < 0.001), and ORR (pooled OR = 0.33; P < 0.001). Similarly, a high PLR was associated with poorer outcomes in response to ICI drugs, including OS (pooled HR = 2.13; P < 0.001) and PFS (pooled HR = 1.61; P < 0.001). CONCLUSION: High NLR and PLR were associated with a statistically significant reduction in the efficacy of ICI drugs in NSCLC patients. Thereby, it is possible to use NLR and PLR as potential and available biomarkers in the clinical practice to predict the outcome of ICI treatment in NSCLC patients.
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Plaquetas , Carcinoma Pulmonar de Células não Pequenas , Inibidores de Checkpoint Imunológico , Neoplasias Pulmonares , Linfócitos , Neutrófilos , Humanos , Plaquetas/efeitos dos fármacos , Carcinoma Pulmonar de Células não Pequenas/sangue , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/imunologia , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Inibidores de Checkpoint Imunológico/farmacologia , Inibidores de Checkpoint Imunológico/uso terapêutico , Neoplasias Pulmonares/sangue , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/mortalidade , Contagem de Linfócitos , Linfócitos/efeitos dos fármacos , Neutrófilos/efeitos dos fármacos , Contagem de Plaquetas , PrognósticoRESUMO
Platelets are core components of thrombi but their effect on thrombus burden during deep vein thrombosis (DVT) has not been fully characterized. We examined the role of thrombopoietin-altered platelet count on thrombus burden in a murine stasis model of DVT. To modulate platelet count compared to baseline, CD1 mice were pretreated with thrombopoietin antisense oligonucleotide (THPO-ASO, 56% decrease), thrombopoietin mimetic (TPO-mimetic, 36% increase), or saline (within 1%). Thrombi and vein walls were examined on postoperative days (POD) 3 and 7. Thrombus weights on POD 3 were not different between treatment groups (p = .84). The mean thrombus weights on POD 7 were significantly increased in the TPO-mimetic cohort compared to the THPO-ASO (p = .005) and the saline (p = .012) cohorts. Histological grading at POD 3 revealed a significantly increased smooth muscle cell presence in the thrombi and CD31 positive channeling in the vein wall of the TPO-mimetic cohort compared to the saline and THPO-ASO cohorts (p < .05). No differences were observed in histology on POD 7. Thrombopoietin-induced increased platelet count increased thrombus weight on POD 7 indicating platelet count may regulate thrombus burden during early resolution of venous thrombi in this murine stasis model of DVT.
Deep vein thrombosis (DVT) is a pathology in which blood clots form in the deep veins of our body. Usually occurring in the legs, these clots can be dangerous if they dislodge and travel to the heart and are pumped into the lungs. Often these clots do not travel and heal where they formed. However, as the body heals the clot it may also cause damage to the vein wall and predispose the patient to future clots, i.e., the biggest risk factor for a second clot is the first clot. DVT can also cause symptoms of pain, swelling, and redness in the long-term, leading to post-thrombotic syndrome where the initial symptoms of the clot persist for a long time. All blood clots have common components of red blood cells, white blood cells, platelets, and fibrin in varying concentrations. Humans maintain a platelet count between 150 and 400 thousand platelets per microliter of our blood. However, diseases like cancer or medications like chemotherapy can cause a change in our body's platelet count. The effect of a changing platelet count on the size (clot burden) of DVT clot and how platelet count could affect DVT as the clot heals is not fully understood. Studying this might help us develop better targets and treat patients with a wide range of platelet counts who experience DVT. In this study, we intentionally decreased, left unchanged, and increased platelet counts in mice and then created a DVT to study what the effect of low, normal, and high platelet counts, respectively, would be on the clot burden. We observed that mice with higher platelet counts had a higher clot burden during the early part of the healing process of the clot. Within this study, we can conclude that higher platelet counts may lead to higher clot burden in DVT which furthers our understanding of how platelet count affects clot burden during DVT.
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Trombose , Trombose Venosa , Humanos , Camundongos , Animais , Trombose Venosa/tratamento farmacológico , Trombose Venosa/patologia , Contagem de Plaquetas , Trombopoetina/farmacologia , Plaquetas/patologiaRESUMO
Inositol-1,4,5-triphosphate (IP3) kinase B (ITPKB) is a ubiquitously expressed lipid kinase that inactivates IP3, a secondary messenger that stimulates calcium release from the endoplasmic reticulum (ER). Genome-wide association studies have identified common variants in the ITPKB gene locus associated with reduced risk of sporadic Parkinson's disease (PD). Here, we investigate whether ITPKB activity or expression level impacts PD phenotypes in cellular and animal models. In primary neurons, knockdown or pharmacological inhibition of ITPKB increased levels of phosphorylated, insoluble α-synuclein pathology following treatment with α-synuclein preformed fibrils (PFFs). Conversely, ITPKB overexpression reduced PFF-induced α-synuclein aggregation. We also demonstrate that ITPKB inhibition or knockdown increases intracellular calcium levels in neurons, leading to an accumulation of calcium in mitochondria that increases respiration and inhibits the initiation of autophagy, suggesting that ITPKB regulates α-synuclein pathology by inhibiting ER-to-mitochondria calcium transport. Furthermore, the effects of ITPKB on mitochondrial calcium and respiration were prevented by pretreatment with pharmacological inhibitors of the mitochondrial calcium uniporter complex, which was also sufficient to reduce α-synuclein pathology in PFF-treated neurons. Taken together, these results identify ITPKB as a negative regulator of α-synuclein aggregation and highlight modulation of ER-to-mitochondria calcium flux as a therapeutic strategy for the treatment of sporadic PD.
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Cálcio/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/genética , alfa-Sinucleína/metabolismo , Animais , Autofagia/genética , Retículo Endoplasmático/metabolismo , Estudo de Associação Genômica Ampla/métodos , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Neurônios/metabolismo , Doença de Parkinson/genética , Doença de Parkinson/metabolismo , Fosforilação/genética , Transdução de Sinais/genética , Sinucleinopatias/genética , Sinucleinopatias/metabolismoRESUMO
Three species of the Rutaceae family, including Acronychia pedunculata, Euodia lepta, and Severinia monophylla have been used in traditional medicine. However, the comparison of the chemical composition, anti-cancer, and anti-inflammatory effects of the leaf essential oils of these species have not been investigated yet. A total of 38 compounds were identified via gas chromatography-mass spectrometry, comprising 96.5-99.8% of the total composition. Both A. pedunculata and E. lepta essential oils exhibited strong inhibitory effects against cancer cells (IC50: 59.04-97.52 µg/mL) while that of S. monophylla showed a lower anti-cancer effect (IC50>100 µg/mL). Among three essential oils, only the E. lepta leaf oil demonstrated a high anti-inflammatory effect on LPS-stimulated macrophages (IC50=6.47 ± 0.65 µg/mL), while the other showed a moderate anti-inflammatory effect (IC50>50 µg/mL). Molecular docking studies also suggested the binding potential of the key compounds from three essential oils against inducible nitric oxide synthase and cyclooxygenase-2, two proteins associated with inflammatory response, with the negative energies ranging from -41.0 to -71.9 kcal/mol. The present findings suggest the leaf essential oils from these species as potential medicines for treatment of cancer or inflammation associated diseases, especially the ones from A. pedunculata and E. lepta oils.
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Antibiotic resistance (AR) rates in Vietnam are among the highest in Asia, and recent infections due to multi-drug resistance in the country have caused thousands of deaths each year. This study investigated a Vietnamese community's preferences for antibiotic treatment and its knowledge and attitudes regarding antibiotics. A discrete choice experiment-based survey was developed and administered to the population of interest. The respondents were given sociodemographic-, knowledge- and attitude-related items and 17 pairs of choice tasks. Two hypothetical options were included in each choice task. Latent class analysis was conducted to determine the differences among the respondents' preferences. Among 1,014 respondents, 805 (79.4%) gave valid questionnaires. A three-latent-class model with four covariates (age, healthcare-related education or career, occupation, and attitude classifications) was used in the analysis. All five attributes significantly influenced the respondents' decisions. The majority, including young employed respondents with non-healthcare-related work or education, found treatment failure more important. Older respondents who had healthcare-related education/careers and/or appropriate antibiotic use- and antibiotics resistance-related attitudes, regarded contribution to antibiotic resistance as an important attribute in selecting antibiotic treatments. Unemployed individuals with correct knowledge identified the cost of antibiotic treatment as the most essential decision-making factor. Findings suggest minimal antibiotic impact on resistance; only 7.83% view it as amajor concern. The respondents exhibited substantial preference heterogeneity, and the general Vietnamese public had poor knowledge of and attitudes toward antibiotic use and antibiotic resistance. This study emphasizes the need for individual responsibility for antibiotic resistance and appropriate antibiotic use.
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Antibacterianos , Comportamento de Escolha , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Feminino , Adulto , Antibacterianos/uso terapêutico , Masculino , Pessoa de Meia-Idade , Vietnã , Adulto Jovem , Inquéritos e Questionários , Adolescente , Preferência do Paciente , Idoso , Resistência Microbiana a MedicamentosRESUMO
BACKGROUND: Dioxin is an environmental pollutant as well as an endocrine disruptor in humans. Our longitudinal study wants to clarify the relationship between dioxin exposure and endocrine disorders in children living in the Vietnamese dioxin hotspot. METHOD: Seventeen congeners of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzo-furans (PCDDs/PCDFs) in maternal breast milk and seven serum steroid hormones in children of 43 and 46 mothers and their 9-year-old children from the non-exposure and the hotspot areas were measured, respectively. The steroid metabolic enzyme ratios were calculated based on the hormone level ratio. RESULTS: Most dioxin/furan congeners and toxic equivalents (TEQs) levels were significantly higher in the hotspot than in the non-exposure area, except for 2,4,7,8-TeCDF. The height and weight of girls from the hotspot area were substantially lower and inversely correlated with dioxin congener levels/total TEQs level dioxin. The dihydrotestosterone (DHT) levels in the hotspot were markedly lower than those in non-exposed in both genders. The cortisol concentrations were significantly higher in the hotspot than those from the non-exposure area only in the girls. The DHT/testosterone ratios that exhibited the 5α- or 5ß-reductase activity declined by 50% in the hotspot area for both genders. The DHT levels showed strong inverse correlations with almost the PCDDs/PCDFs congeners and total TEQs dioxin in breast milk. CONCLUSIONS: This finding suggests that dioxin exposure in maternal breast milk might impact children's endocrine system until 9 years old, especially on the DHT biosynthesis.
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Di-Hidrotestosterona , Dioxinas , Exposição Ambiental , Poluentes Ambientais , Leite Humano , Humanos , Vietnã , Criança , Feminino , Di-Hidrotestosterona/sangue , Masculino , Poluentes Ambientais/sangue , Poluentes Ambientais/análise , Leite Humano/química , Dioxinas/sangue , Dioxinas/análise , Exposição Ambiental/análise , Estudos Longitudinais , Dibenzodioxinas Policloradas/sangue , Adulto , Disruptores Endócrinos/sangue , Disruptores Endócrinos/análise , População do Sudeste AsiáticoRESUMO
The functional properties of proteorhodopsin (PR) have been found to be strongly modulated by oligomeric distributions and lipid membrane mimetics. This study aims to distinguish and explain their effects by investigating how oligomer formation impacts PR's function of proton transport in lipid-based membrane mimetic environments. We find that PR forms stable hexamers and pentamers in both E. coli membranes and synthetic liposomes. Compared with the monomers, the photocycle kinetics of PR oligomers is â¼2 and â¼4.5 times slower for transitions between the K and M and the M and N photointermediates, respectively, indicating that oligomerization significantly slows PR's rate of proton transport in liposomes. In contrast, the apparent pKa of the key proton acceptor residue D97 (pKaD97) of liposome-embedded PR persists at 6.2-6.6, regardless of cross-protomer modulation of D97, suggesting that the liposome environment helps maintain PR's functional activity at neutral pH. By comparison, when extracted directly from E. coli membranes into styrene-maleic acid lipid particles, the pKaD97 of monomer-enriched E50Q PR drastically increases to 8.9, implying that there is a very low active PR population at neutral pH to engage in PR's photocycle. These findings demonstrate that oligomerization impacts PR's photocycle kinetics, while lipid-based membrane mimetics strongly affect PR's active population via different mechanisms.
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Escherichia coli , Lipossomos , Prótons , Rodopsinas Microbianas/química , LipídeosRESUMO
Fragment antigen-binding domains of antibodies (Fabs) are powerful probes of structure-function relationships of assembly line polyketide synthases (PKSs). We report the discovery and characterization of Fabs interrogating the structure and function of the ketosynthase-acyltransferase (KS-AT) core of Module 2 of the 6-deoxyerythronolide B synthase (DEBS). Two Fabs (AC2 and BB1) were identified to potently inhibit the catalytic activity of Module 2. Both AC2 and BB1 were found to modulate ACP-mediated reactions catalyzed by this module, albeit by distinct mechanisms. AC2 primarily affects the rate (kcat), whereas BB1 increases the KM of an ACP-mediated reaction. A third Fab, AA5, binds to the KS-AT fragment of DEBS Module 2 without altering either parameter; it is phenotypically reminiscent of a previously characterized Fab, 1B2, shown to principally recognize the N-terminal helical docking domain of DEBS Module 3. Crystal structures of AA5 and 1B2 bound to the KS-AT fragment of Module 2 were solved to 2.70 and 2.65 Å resolution, respectively, and revealed entirely distinct recognition features of the two antibodies. The new tools and insights reported here pave the way toward advancing our understanding of the structure-function relationships of DEBS Module 2, arguably the most well-studied module of an assembly line PKS.
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Eritromicina , Policetídeo Sintases , Policetídeo Sintases/química , Aciltransferases/química , AnticorposRESUMO
Most eukaryotic secretory proteins are cotranslationally translocated through Sec61 into the endoplasmic reticulum (ER). Because these proteins have evolved to fold in the ER, their mistargeting is associated with toxicity. Genetic experiments have implicated the ER heat shock protein 70 (Hsp70) Hspa13/STCH as involved in processing of nascent secretory proteins. Herein, we evaluate the role of Hspa13 in protein import and the maintenance of cellular proteostasis in human cells, primarily using the human embryonic kidney 293T cell line. We find that Hspa13 interacts primarily with the Sec61 translocon and its associated factors. Hspa13 overexpression inhibits translocation of the secreted protein transthyretin, leading to accumulation and aggregation of immature transthyretin in the cytosol. ATPase-inactive mutants of Hspa13 further inhibit translocation and maturation of secretory proteins. While Hspa13 overexpression inhibits cell growth and ER quality control, we demonstrate that HSPA13 knockout destabilizes proteostasis and increases sensitivity to ER disruption. Thus, we propose that Hspa13 regulates import through the translocon to maintain both ER and cytosolic protein homeostasis. The raw mass spectrometry data associated with this article have been deposited in the PRIDE archive and can be accessed at PXD033498.
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Proteínas de Choque Térmico , Proteostase , Humanos , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Pré-Albumina/metabolismo , Citosol/metabolismo , Retículo Endoplasmático/genética , Retículo Endoplasmático/metabolismo , Transporte Proteico , Canais de Translocação SEC/metabolismoRESUMO
BACKGROUND: Timely diagnosis of meniscus injuries is key for preventing knee joint dysfunction and improving patient outcomes because it decreases morbidity and facilitates treatment planning. PURPOSE: To train and evaluate a deep learning model for automated detection of meniscus tears on knee magnetic resonance imaging (MRI). STUDY TYPE: Bicentric retrospective study. SUBJECTS: In total, 584 knee MRI studies, divided among training (n = 234), testing (n = 200), and external validation (n = 150) data sets, were used in this study. The public data set MRNet was used as a second external validation data set to evaluate the performance of the model. SEQUENCE: A 3 T, coronal, and sagittal images from T1-weighted proton density (PD) fast spin-echo (FSE) with fat saturation and T2-weighted FSE with fat saturation sequences. ASSESSMENT: The detection system for meniscus tear was based on the improved YOLOv4 model with Darknet-53 as the backbone. The performance of the model was also compared with that of three radiologists of varying levels of experience. The determination of the presence of a meniscus tear from surgery reports was used as the ground truth for the images. STATISTICAL TESTS: Sensitivity, specificity, prevalence, positive predictive value, negative predictive value, accuracy, and receiver operating characteristic curve were used to evaluate the performance of the detection model. Two-way analysis of variance, Wilcoxon signed-rank test, and Tukey's multiple tests were used to evaluate differences in performance between the model and radiologists. RESULTS: The overall accuracies for detecting meniscus tears using our model on the internal testing, internal validation, and external validation data sets were 95.4%, 95.8%, and 78.8%, respectively. One radiologist had significantly lower performance than our model in detecting meniscal tears (accuracy: 0.9025 ± 0.093 vs. 0.9580 ± 0.025). DATA CONCLUSION: The proposed model had high sensitivity, specificity, and accuracy for detecting meniscus tears on knee MRIs. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 2.
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Menisco , Lesões do Menisco Tibial , Humanos , Estudos Retrospectivos , Meniscos Tibiais , Lesões do Menisco Tibial/diagnóstico por imagem , Lesões do Menisco Tibial/patologia , Artroscopia , Articulação do Joelho/patologia , Imageamento por Ressonância Magnética/métodos , Sensibilidade e Especificidade , Redes Neurais de ComputaçãoRESUMO
The aim of this study is to analyse the changing patterns in the transmission of COVID-19 in relation to changes in Vietnamese governmental policies, based on epidemiological data and policy actions in a large Vietnamese province, Bac Ninh, in 2021. Data on confirmed cases from January to December 2021 were collected, together with policy documents. There were three distinct periods of the COVID-19 pandemic in Bac Ninh province during 2021. During the first period, referred to as the 'Zero-COVID' period (01/04-07/04/2021), there was a low population vaccination rate, with less than 25% of the population receiving its first vaccine dose. Measures implemented during this period focused on domestic movement restrictions, mask mandates, and screening efforts to control the spread of the virus. The subsequent period, referred to as the 'Transition' period (07/05-10/22/2021), witnessed a significant increase in population vaccination coverage, with 80% of the population receiving their first vaccine dose. During this period, several days passed without any reported COVID-19 cases in the community. The local government implemented measures to manage domestic actions and reduce the time spent in quarantine, and encouraged home quarantining for the close contacts of cases with COVID-19. Finally, the 'New-normal' stage (10/23-12/31/2021), during which the population vaccination coverage with a second vaccine dose increased to 70%, and most of the mandates for the prevention and control of COVID-19 were reduced. In conclusion, this study highlights the importance of governmental policies in managing and controlling the transmission of COVID-19 and provides insights for developing realistic and context-specific strategies in similar settings.
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COVID-19 , Humanos , COVID-19/epidemiologia , COVID-19/prevenção & controle , Pandemias/prevenção & controle , Quarentena , SARS-CoV-2 , Vietnã/epidemiologiaRESUMO
Ten new norterpene alkaloids, coscinoderines A-J (1-10), were isolated from the marine sponge Coscinoderma bakusi. Each coscinoderine contains a 1,2,5-trisubstituted pyridinium moiety bearing a terpene unit at the C-2 position. Their structures were elucidated by analysis of NMR and HRMS data, and the absolute stereochemistry of 4 with a 2-methylbutyl group attached to the nitrogen was determined from a comparison of the calculated and measured ECD spectra. The isolation of coscinoderines expands the repertoire of pyridinium alkaloids isolated from marine sponges.
Assuntos
Alcaloides , Poríferos , Animais , Poríferos/química , Alcaloides/farmacologia , Alcaloides/química , Espectroscopia de Ressonância Magnética , Terpenos , Estrutura MolecularRESUMO
BACKGROUND: Patients on continuous flow ventricular assist devices (CF-VADs) are at high risk for the development of Acquired von-Willebrand Syndrome (AVWS) and non-surgical bleeding. von Willebrand Factor (vWF) plays an essential role in maintaining hemostasis via platelet binding to the damaged endothelium to facilitate coagulation. In CF-VAD patients, degradation of vWF into low MW multimers that are inefficient in facilitating coagulation occurs and has been primarily attributed to the supraphysiological shear stress associated with the CF-VAD impeller. METHODS: In this review, we evaluate information from the literature regarding the unraveling behavior of surface-immobilized vWF under pulsatile and continuous flow pertaining to: (A) the process of arterial endothelial vWF production and release into circulation, (B) the critical shear stress required to unravel surface bound versus soluble vWF which leads to degradation, and (C) the role of pulsatility in on the production and degradation of vWF. RESULTS AND CONCLUSION: Taken together, these data suggests that the loss of pulsatility and its impact on arterial endothelial cells plays an important role in the production, release, unraveling, and proteolytic degradation of vWF into low MW multimers, contributing to the development of AVWS. Restoration of pulsatility can potentially mitigate this issue by preventing AVWS and minimizing the risk of non-surgical bleeding.