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α-synuclein (α-Syn) is a presynaptic protein that is involved in Parkinson's and other neurodegenerative diseases and binds to negatively charged phospholipids. Previously, we reported that α-Syn clusters synthetic proteoliposomes that mimic synaptic vesicles. This vesicle-clustering activity depends on a specific interaction of α-Syn with anionic phospholipids. Here, we report that α-Syn surprisingly also interacts with the neutral phospholipid lysophosphatidylcholine (lysoPC). Even in the absence of anionic lipids, lysoPC facilitates α-Syn-induced vesicle clustering but has no effect on Ca2+-triggered fusion in a single vesicle-vesicle fusion assay. The A30P mutant of α-Syn that causes familial Parkinson disease has a reduced affinity to lysoPC and does not induce vesicle clustering. Taken together, the α-Syn-lysoPC interaction may play a role in α-Syn function.
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Doença de Parkinson , alfa-Sinucleína , Humanos , alfa-Sinucleína/genética , alfa-Sinucleína/metabolismo , Vesículas Sinápticas/metabolismo , Lisofosfatidilcolinas/metabolismo , Doença de Parkinson/genética , Doença de Parkinson/metabolismo , Fosfolipídeos/metabolismoRESUMO
Human coronavirus 229E (HCoV-229E) and NL63 (HCoV-NL63) are endemic causes of upper respiratory infections such as the "common cold" but may occasionally cause severe lower respiratory tract disease in the elderly and immunocompromised patients. There are no approved antiviral drugs or vaccines for these common cold coronaviruses (CCCoV). The recent emergence of COVID-19 and the possible cross-reactive antibody and T cell responses between these CCCoV and SARS-CoV-2 emphasize the need to develop experimental animal models for CCCoV. Mice are an ideal experimental animal model for such studies, but are resistant to HCoV-229E and HCoV-NL63 infections. Here, we generated 229E and NL63 mouse models by exogenous delivery of their receptors, human hAPN and hACE2 using replication-deficient adenoviruses (Ad5-hAPN and Ad5-hACE2), respectively. Ad5-hAPN- and Ad5-hACE2-sensitized IFNAR-/- and STAT1-/- mice developed pneumonia characterized by inflammatory cell infiltration with virus clearance occurring 7 d post infection. Ad5-hAPN- and Ad5-hACE2-sensitized mice generated virus-specific T cells and neutralizing antibodies after 229E or NL63 infection, respectively. Remdesivir and a vaccine candidate targeting spike protein of 229E and NL63 accelerated viral clearance of virus in these mice. 229E- and NL63-infected mice were partially protected from SARS-CoV-2 infection, likely mediated by cross-reactive T cell responses. Ad5-hAPN- and Ad5-hACE2-transduced mice are useful for studying pathogenesis and immune responses induced by HCoV-229E and HCoV-NL63 infections and for validation of broadly protective vaccines, antibodies, and therapeutics against human respiratory coronaviruses including SARS-CoV-2.
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COVID-19 , Resfriado Comum , Coronavirus Humano 229E , Coronavirus Humano NL63 , Humanos , Animais , Camundongos , Idoso , SARS-CoV-2 , Proteção CruzadaRESUMO
The involvement of secreted phospholipase A2s in respiratory diseases, such as asthma and respiratory viral infections, is well-established. However, the specific role of secreted phospholipase A2 group IIE (PLA2G2E) during influenza virus infection remains unexplored. Here, we investigated the role of PLA2G2E during H1N1 influenza virus infection using a targeted mouse model lacking Pla2g2e gene (Pla2g2e-/-). Our findings demonstrated that Pla2g2e-/- mice had significantly lower survival rates and higher viral loads in lungs compared to wild-type mice following influenza virus infection. While Pla2g2e-/- mice displayed comparable innate and humoral immune responses to influenza virus challenge, the animals showed impaired influenza-specific cellular immunity and reduced T cell-mediated cytotoxicity. This indicates that PLA2G2E is involved in regulating specific T cell responses during influenza virus infection. Furthermore, transgenic mice expressing the human PLA2G2E gene exhibited resistance to influenza virus infection along with enhanced influenza-specific cellular immunity and T cell-mediated cytotoxicity. Pla2g2e deficiency resulted in perturbation of lipid mediators in the lung and T cells, potentially contributing to its impact on the anti-influenza immune response. Taken together, these findings suggest that targeting PLA2G2E could hold potential as a therapeutic strategy for managing influenza virus infections.IMPORTANCEThe influenza virus is a highly transmissible respiratory pathogen that continues to pose a significant public health concern. It effectively evades humoral immune protection conferred by vaccines and natural infection due to its continuous viral evolution through the genetic processes of antigenic drift and shift. Recognition of conserved non-mutable viral epitopes by T cells may provide broad immunity against influenza virus. In this study, we have demonstrated that phospholipase A2 group IIE (PLA2G2E) plays a crucial role in protecting against influenza virus infection through the regulation of T cell responses, while not affecting innate and humoral immune responses. Targeting PLA2G2E could therefore represent a potential therapeutic strategy for managing influenza virus infection.
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Vírus da Influenza A Subtipo H1N1 , Pulmão , Infecções por Orthomyxoviridae , Animais , Camundongos , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/virologia , Vírus da Influenza A Subtipo H1N1/imunologia , Pulmão/virologia , Pulmão/imunologia , Pulmão/patologia , Humanos , Fosfolipases A2 do Grupo II/genética , Fosfolipases A2 do Grupo II/imunologia , Linfócitos T/imunologia , Camundongos Knockout , Imunidade Celular , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Carga Viral , Modelos Animais de Doenças , Imunidade Humoral , Imunidade Inata , Influenza Humana/imunologia , Influenza Humana/virologia , FemininoRESUMO
Secreted phospholipase A2s are involved in the development of obesity, type 2 diabetes mellitus (T2DM) and cardiovascular disease, which have become serious and growing health concerns worldwide. Integration of genome-wide association study and gene co-expression networks analysis showed that the secreted phospholipase A2 group XIIA (PLA2G12A) may participate in hepatic lipids metabolism. Nevertheless, the role of PLA2G12A in lipid metabolism and its potential mechanism remain elusive. Here, we used AAV9 vector carrying human PLA2G12A gene to exogenously express hPLA2G12A in the liver of mice. We demonstrated that the overexpression of hPLA2G12A resulted in a significant decrease in serum lipid levels in wild-type mice fed with chow diet or high-fat diet (HFD). Moreover, hPLA2G12A treatment protected against diet-induced obesity and insulin resistance in mice fed a HFD. Notably, we found that hPLA2G12A treatment confers protection against obesity and hyperlipidemia independent of its enzymatic activity, but rather by increasing physical activity and energy expenditure. Furthermore, we demonstrated that hPLA2G12A treatment induced upregulation of ApoC2 and Cd36 and downregulation of Angptl8, which contributed to the increase in clearance of circulating triglycerides and hepatic uptake of fatty acids without affecting hepatic de novo lipogenesis, very low-density lipoprotein secretion, or intestinal lipid absorption. Our study highlights the potential of PLA2G12A gene therapy as a promising approach for treating obesity, insulin resistance and T2DM.
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Dieta Hiperlipídica , Metabolismo Energético , Resistência à Insulina , Camundongos Endogâmicos C57BL , Obesidade , Triglicerídeos , Animais , Obesidade/metabolismo , Obesidade/etiologia , Camundongos , Triglicerídeos/metabolismo , Triglicerídeos/sangue , Masculino , Dieta Hiperlipídica/efeitos adversos , Humanos , Fígado/metabolismo , Metabolismo dos LipídeosRESUMO
Protein misfolding and aggregation, a key contributor to the progression of numerous neurodegenerative diseases, results in functional deficiencies and the creation of harmful intermediates. Detailed visualization of this misfolding process is of paramount importance for improving our understanding of disease mechanisms and for the development of potential therapeutic strategies. While in vitro studies using purified proteins have been instrumental in delivering significant insights into protein misfolding, the behavior of these proteins in the complex milieu of living cells often diverges significantly from such simplified environments. Biomedical imaging performed in cell provides cellular-level information with high physiological and pathological relevance, often surpassing the depth of information attainable through in vitro methods. This review highlights a variety of methodologies used to scrutinize protein misfolding within biological systems. This includes optical-based methods, strategies leaning on mass spectrometry, in-cell nuclear magnetic resonance, and cryo-electron microscopy. Recent advancements in these techniques have notably deepened our understanding of protein misfolding processes and the features of the resulting misfolded species within living cells. The progression in these fields promises to catalyze further breakthroughs in our comprehension of neurodegenerative disease mechanisms and potential therapeutic interventions.
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Doenças Neurodegenerativas , Humanos , Doenças Neurodegenerativas/diagnóstico por imagem , Doenças Neurodegenerativas/metabolismo , Dobramento de Proteína , Microscopia Crioeletrônica , Proteínas/químicaRESUMO
Hydrogen production from photocatalysis via the usage of multicomponent photocatalysts represents a promising pathway for carbon peaking and carbon neutrality, owing to their structural advantages in dealing with the three crucial processes in photocatalysis, namely, light harvesting, charge transfer, and surface redox reactions. We demonstrate the fabrication of a MOF-based multicomponent photocatalyst, denoted as semiconductor/MOF/cocatalyst, by a one-pot electrochemical synthetic route. The as-fabricated multicomponent photocatalyst has a clean interface among the components, leading to close connections that contribute to high-quality heterojunction and facilitate photogenerated charge transfer and separation, thereby the efficient hydrogen evolution. The hydrogen production rate of the resultant ZrO2 /Zr-MOF/Pt is 1327â µmol â g-1 â h-1 , which is much higher than that of ZrO2 /Zr-MOF (15â µmol â g-1 â h-1 ) and pure Zr-MOF (10.1â µmol â g-1 â h-1 ), as well as the photodeposited-Pt products ZrO2 /Zr-MOF/PtPD (287â µmol â g-1 â h-1 ) and Zr-MOF/PtPD (192â µmol â g-1 â h-1 ) obtained by the step-wise synthetic approach. The work gives a good inspiration for the rational design and construction of MOF-based multicomponent photocatalysts through the one-pot electrosynthesis.
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Sweating is a basic skin function in body temperature control. In sweat glands, salt excretion and reabsorption are regulated to avoid electrolyte imbalance. To date, the mechanism underlying such regulation is not fully understood. Corin is a transmembrane protease that activates atrial natriuretic peptide (ANP), a cardiac hormone essential for normal blood volume and pressure. Here, we report an unexpected role of corin in sweat glands to promote sweat and salt excretion in regulating electrolyte homeostasis. In human and mouse eccrine sweat glands, corin and ANP are expressed in the luminal epithelial cells. In corin-deficient mice on normal- and high-salt diets, sweat and salt excretion is reduced. This phenotype is associated with enhanced epithelial sodium channel (ENaC) activity that mediates Na+ and water reabsorption. Treatment of amiloride, an ENaC inhibitor, normalizes sweat and salt excretion in corin-deficient mice. Moreover, treatment of aldosterone decreases sweat and salt excretion in wild-type (WT), but not corin-deficient, mice. These results reveal an important regulatory function of corin in eccrine sweat glands to promote sweat and salt excretion.
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Glândulas Écrinas/fisiologia , Serina Endopeptidases/metabolismo , Cloreto de Sódio/metabolismo , Animais , Fator Natriurético Atrial/metabolismo , Glândulas Écrinas/metabolismo , Eletrólitos/metabolismo , Folículo Piloso/metabolismo , Homeostase/fisiologia , Humanos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Serina Endopeptidases/genética , Suor/química , Água/metabolismoRESUMO
The excitation-dependent emission properties of carbon dots (Cdots) are extensively reported, but their red emission is often weak, limiting their wider application. Here we introduce ethidium bromide, as a functional precursor with red emission, to enhance the red emission for Cdots, with comparable intensity at a broad wavelength range to multi-emission Cdots (M-Cdots). We found that Cdots prepared with ethidium bromide/ethylenediamine exhibited strong blue and red emission at 440 and 615 nm, with optimal excitation at 360 and 470 nm as M-Cdots, respectively, but the Cdots from single ethidium bromide (EB-Cdots) possessed weak red emission. M-Cdots exhibited a broad absorption band at 478 nm, but a band blue-shifted to 425 nm was observed for EB-Cdots, while no absorption was observed at 478-425 nm for the Cdots prepared with citric acid and ethylenediamine. Thus, we proposed that C=O and C=N formed a π-conjugation structure as the absorption band at 478 nm for the red emission of M-Cdots, as also confirmed with the excitation at 470 nm. Moreover, the π-conjugation structure is fragile and sensitive to harsh conditions, so red emission was difficult to observe for the Cdots prepared with citric acid/ethylenediamine or single ethidium bromide. M-Cdots possess two centers for blue and red emission with different structures. The dual emission was therefore used for ratiometric sensing with dichromate (Cr2O72-) and formaldehyde (HCHO) as the targets using the intensity ratio of the emissions at 615 and 440 nm. Due to the comparable intensity at a broad wavelength range, we designed encryption codes with five excitations at 360, 400, 420, 450, and 470 nm as the inputs, and the emission colors were used for information decoding. Thus, we determined why red emission was difficult to realize for Cdots, and our results could motivate the design of red-emission Cdots for extensive applications.
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BACKGROUND: There is a strong association between cardiovascular disease (CVD) and periodontitis. This study utilized the Life Essentials 8 (LE8) score, a composite measure of cardiovascular health (CVH), to elucidate the relationship between CVH and periodontitis. METHODS: Data from 8,649 nationally representative participants in the National Health and Nutrition Examination Survey (NHANES) were analyzed. The independent variable in our study was the CVH score (a higher CVH score indicates better cardiovascular health), and the dependent variable was the presence or absence of periodontitis. The association between CVH and periodontitis was investigated using weighted multivariable logistic regression models and restricted cubic spline (RCS). We controlled for potential confounders such as age, sex, race, education, and socioeconomic status to minimize bias. RESULTS: There was a negative association between the total CVH score and the odds of periodontitis. After adjusting for all covariates, a 10-point increase in total CVH score was associated with a 10% lower in the odds of periodontitis [0.90 (0.87, 0.93)]. Participants with a higher CVH had 40% lower odds of periodontitis compared with those with a lower CVH. Socioeconomic status (education and income) modified this association (P for interaction < 0.05). CONCLUSION: Our study suggests that better cardiovascular health, as indicated by higher CVH scores, is associated with a reduced likelihood of periodontitis among US adults. The relationship between CVH and periodontitis appears to be influenced by socioeconomic status, emphasizing the need for targeted interventions in populations with lower socioeconomic status.
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Doenças Cardiovasculares , Periodontite , Adulto , Humanos , Estados Unidos/epidemiologia , Fatores de Risco , Inquéritos Nutricionais , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/diagnóstico , Classe Social , Periodontite/epidemiologia , Nível de SaúdeRESUMO
BACKGROUND: Tooth loss is a common problem that affects many people worldwide. Exploring knowledge, attitude, and practice (KAP) among patients can identify barriers and challenges in following recommended practices, providing valuable insights for dental healthcare providers, policymakers, and researchers. This study aimed to explore the KAP of patients with dental arch deficiencies regarding tooth loss and dentures. METHODS: This web-based, cross-sectional study was conducted among patients with dental arch deficiencies using a self-designed questionnaire. RESULT: 3166 valid questionnaires were included. Participants' mean KAP scores were 6.84 ± 2.27 (possible range: 0 ~ 12), 39.4 ± 3.72 (possible range: 9 ~ 45), and 27.7 ± 4.36 (possible range: 8 ~ 40), respectively. Multivariable logistic regression analysis showed that knowledge (OR = 1.383), employed (OR = 1.805), family history (OR = 2.158), and treatment (OR = 1.683) were independently associated with attitude. Moreover, knowledge (OR = 1.239), attitude (OR = 1.250), female (OR = 0.619), age (OR = 0.967), college/bachelor (OR = 0.373), and master and above degree (OR = 0.418), employed (OR = 0.554) or student (OR = 0.434), with 10,001-20,000 Yuan household income per month (OR = 0.492), have been married (OR = 0.609), smoking (OR = 0.595), drinking (OR = 0.397), disease duration (OR = 0.972), with family history (OR = 1.676), and with treatment (OR = 3.492) were independently associated with practice (all P < 0.05). CONCLUSION: Patients with dental arch deficiencies have insufficient knowledge, positive attitudes, and moderate practice toward tooth loss and dentures, which might be affected by multiple demographic factors.
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Dentaduras , Conhecimentos, Atitudes e Prática em Saúde , Perda de Dente , Humanos , Feminino , Masculino , Estudos Transversais , Pessoa de Meia-Idade , Adulto , Inquéritos e Questionários , Dentaduras/estatística & dados numéricos , Arco Dental , Idoso , Adulto JovemRESUMO
The spread of pathological α-synuclein (α-syn) is a crucial event in the progression of Parkinson's disease (PD). Cell surface receptors such as lymphocyte activation gene 3 (LAG3) and amyloid precursor-like protein 1 (APLP1) can preferentially bind α-syn in the amyloid over monomeric state to initiate cell-to-cell transmission. However, the molecular mechanism underlying this selective binding is unknown. Here, we perform an array of biophysical experiments and reveal that LAG3 D1 and APLP1 E1 domains commonly use an alkaline surface to bind the acidic C terminus, especially residues 118 to 140, of α-syn. The formation of amyloid fibrils not only can disrupt the intramolecular interactions between the C terminus and the amyloid-forming core of α-syn but can also condense the C terminus on fibril surface, which remarkably increase the binding affinity of α-syn to the receptors. Based on this mechanism, we find that phosphorylation at serine 129 (pS129), a hallmark modification of pathological α-syn, can further enhance the interaction between α-syn fibrils and the receptors. This finding is further confirmed by the higher efficiency of pS129 fibrils in cellular internalization, seeding, and inducing PD-like α-syn pathology in transgenic mice. Our work illuminates the mechanistic understanding on the spread of pathological α-syn and provides structural information for therapeutic targeting on the interaction of α-syn fibrils and receptors as a potential treatment for PD.
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Precursor de Proteína beta-Amiloide/metabolismo , Amiloide/metabolismo , Antígenos CD/metabolismo , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia , alfa-Sinucleína/metabolismo , Animais , Linhagem Celular Tumoral , Endocitose , Humanos , Camundongos , Degeneração Neural/patologia , Neurônios/metabolismo , Fosforilação , Fosfosserina/metabolismo , Ligação Proteica , Eletricidade Estática , alfa-Sinucleína/química , alfa-Sinucleína/toxicidade , Proteína do Gene 3 de Ativação de LinfócitosRESUMO
BACKGROUND: Gartland Type III supracondylar humerus fractures (SCHFs) are commonly treated using closed reduction followed by percutaneous pin fixation. However, conversion to open reduction may be necessary if closed reduction fails. This study aimed to identify risk factors associated with failed closed reduction and provide a theoretical basis for clinical decision-making in the treatment of Gartland Type III fractures. METHODS: A retrospective analysis was conducted on children with Gartland Type III SCHF who underwent surgical treatment between April 2017 and June 2018. Based on whether or not the closed reduction was successful, patients were split into the open reduction group and the closed reduction group. Within the closed reduction group, subgroup analysis based on surgery duration was carried out. Data were collected from medical records and X-ray images. Univariate and multivariate regression analyses were utilized to evaluate the relationship between variables and failed closed reduction. RESULTS: The study included 36 patients in the open reduction group and 135 patients in the closed reduction group. Multivariate analysis revealed that the presence of angle (P = .024, OR = 3.199), rotation (P = .000, OR = 6.359), skin creases (P = .013, OR = 4.077), anterior-posterior displacement ratio (P = .011, OR = 4.337), fracture angle in the anteroposterior view (P = .014, OR = 0.939), and fracture distal displacement direction (P = .002, OR = 5.384) were independent risk factors for failed closed reduction. Subgroup analysis showed that fracture distal displacement direction (P = .013), skin folds (P = .013), lateral displacement ratio (P = .016), and anterior-posterior displacement value (P = .005) significantly influenced the duration of closed reduction surgery. CONCLUSION: The presence of sharp angle or rotation at the fracture ends, skin folds on the anterior elbow, minor anterior-posterior displacement of the fracture, higher medial inclination of the fracture plane, and distal fracture displacement toward the radial side are independent risk factors for failed closed reduction in pediatric Gartland Type III SCHF.
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Amyloid fibrillar assemblies, originally identified as pathological entities in neurodegenerative diseases, have been widely adopted by various proteins to fulfill diverse biological functions in living organisms. Due to their unique features, such as hierarchical assembly, exceptional mechanical properties, environmental stability, and self-healing properties, amyloid fibrillar assemblies have been employed as functional materials in numerous applications. Recently, with the rapid advancement in synthetic biology and structural biology tools, new trends in the functional design of amyloid fibrillar assemblies have begun to emerge. In this review, we provide a comprehensive overview of the design principles for functional amyloid fibrillar assemblies from an engineering perspective, as well as through the lens of structural insights. Initially, we introduce the fundamental structural configurations of amyloid assemblies and highlight the functions of representative examples. We then focus on the underlying design principles of two prevalent strategies for the design of functional amyloid fibrillar assemblies: (1) introducing new functions via protein modular design and/or hybridization, with typical applications encompassing catalysis, virus disinfection, biomimetic mineralization, bio-imaging, and biotherapy; and (2) dynamically regulating living amyloid fibrillar assemblies using synthetic gene circuits, with typical applications in pattern formation, leakage repair, and pressure sensing. Next, we summarize how breakthroughs in characterization techniques have contributed to unveiling the structural polymorphism of amyloid fibrils at the atomic level, and further clarifying the highly diverse regulation mechanisms of amyloid fibrillar assembly and disassembly fine-tuned by various factors. The structural knowledge may significantly aid in the structure-guided design of amyloid fibrillar assemblies with diverse bio-activities and adjustable regulatory properties. Finally, we envision that a new trend in functional amyloid design may emerge by integrating structural tunability, synthetic biology and artificial intelligence.
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Amiloide , Inteligência Artificial , Amiloide/química , Proteínas AmiloidogênicasRESUMO
We formulate the chiral decomposition rules that govern the electronic structure of a broad family of twisted N + M multilayer graphene configurations that combine arbitrary stacking order and a mutual twist. We show that at the magic angle in the chiral limit the low-energy bands of such systems are composed of chiral pseudospin doublets that are energetically entangled with two flat bands per valley induced by the moiré superlattice potential. The analytic construction is supported by explicit numerical calculations based on realistic parametrization. We further show that vertical displacement fields can open energy gaps between the pseudospin doublets and the two flat bands, such that the flat bands may carry nonzero valley Chern numbers. These results provide guidelines for the rational design of topological and correlated states in generic twisted graphene multilayers.
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Mitochondria are sensitive organelles that sense intrinsic and extrinsic stressors and maintain cellular physiological functions through the dynamic homeostasis of mitochondrial fusion and fission. Numerous pathological processes are associated with mitochondrial fusion and fission disorders. However, the molecular mechanism by which stress induces cardiac pathophysiological changes through destabilising mitochondrial fusion and fission is unclear. Therefore, this study aimed to investigate whether the endoplasmic reticulum stress signalling pathway initiated by the turbulence of mitochondrial fusion and fission under stressful circumstances is involved in cardiomyocyte damage. Based on the successful establishment of the classical stress rat model of restraint plus ice water swimming, we measured the content of serum lactate dehydrogenase. We used haematoxylin-eosin staining, special histochemical staining, RT-qPCR and western blotting to clarify the cardiac pathology, ultrastructural changes and expression patterns of mitochondrial fusion and fission marker proteins and endoplasmic reticulum stress signalling pathway proteins. The results indicated that mitochondrial fusion and fission markers and proteins of the endoplasmic reticulum stress JNK signalling pathway showed significant abnormal dynamic changes with the prolongation of stress, and stabilisation of mitochondrial fusion and fission using Mdivi-1 could effectively improve these abnormal expressions and ameliorate cardiomyocyte injury. These findings suggest that stress could contribute to pathological cardiac injury, closely linked to the endoplasmic reticulum stress JNK signalling pathway induced by mitochondrial fusion and fission turbulence.
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Dinâmica Mitocondrial , Miócitos Cardíacos , Ratos , Animais , Miócitos Cardíacos/metabolismo , Transdução de Sinais , Estresse do Retículo Endoplasmático/genéticaRESUMO
Molecular chaperones safeguard cellular protein homeostasis and obviate proteotoxicity. In the process of aging, as chaperone networks decline, aberrant protein amyloid aggregation accumulates in a mechanism that underpins neurodegeneration, leading to pathologies such as Alzheimer's disease and Parkinson's disease. Thus, it is important to identify and characterize chaperones for preventing such protein aggregation. In this work, we identified that the NAD+ synthase-nicotinamide mononucleotide adenylyltransferase (NMNAT) 3 from mouse (mN3) exhibits potent chaperone activity to antagonize aggregation of a wide spectrum of pathological amyloid client proteins including α-synuclein, Tau (K19), amyloid ß, and islet amyloid polypeptide. By combining NMR spectroscopy, cross-linking mass spectrometry, and computational modeling, we further reveal that mN3 uses different region of its amphiphilic surface near the active site to directly bind different amyloid client proteins. Our work demonstrates a client recognition mechanism of NMNAT via which it chaperones different amyloid client proteins against pathological aggregation and implies a potential protective role for NMNAT in different amyloid-associated diseases.
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Proteínas Amiloidogênicas , Nicotinamida-Nucleotídeo Adenililtransferase , Proteínas Amiloidogênicas/metabolismo , Animais , Camundongos , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Nicotinamida-Nucleotídeo Adenililtransferase/genética , Nicotinamida-Nucleotídeo Adenililtransferase/metabolismo , Agregação Patológica de Proteínas/fisiopatologiaRESUMO
Many amyloid fibrils associated with neurodegenerative diseases consist of an ordered fibril core (FC) and disordered terminal regions (TRs). The former represents a stable scaffold, while the latter is rather active in binding with various partners. Current structural studies mainly focus on the ordered FC since the high flexibility of TRs hinders structural characterization. Here, by combining insensitive nuclei enhanced by polarization transfer-based 1H-detected solid-state NMR and cryo-EM, we explored the intact structure of an α-syn fibril including both FC and TRs and further studied the conformational dynamics of the fibril upon binding to lymphocyte activation gene 3 (LAG3)âa cell surface receptor that is involved in α-syn fibril transmission in brains. We found that both the N- and C-TRs of α-syn are disordered in free fibrils featuring similar conformation ensembles as those in soluble monomers. While in the presence of the D1 domain of LAG3 (L3D1), the C-TR directly binds to L3D1, meanwhile the N-TR folds into a ß-strand and further integrates with the FC, which leads to alteration of the overall fibril structure and surface property. Our work reveals synergistic conformational transition of the intrinsically disordered TRs of α-syn, which sheds light on mechanistic understanding of the essential role of TRs in regulating the structure and pathology of amyloid fibrils.
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Amiloide , alfa-Sinucleína , alfa-Sinucleína/química , Microscopia Crioeletrônica , Espectroscopia de Ressonância Magnética , Conformação Molecular , Amiloide/químicaRESUMO
Vancomycin is recommended for the treatment of skin and soft tissue infections (SSTI) and bone and joint infections (BJI). However, a detailed investigation of the pharmacokinetic profile and optimal dosing regimens of vancomycin in pediatric patients with SSTI and BJI is lacking. We successfully developed a new PopPK model of vancomycin in this population by using scavenged blood samples with the typical values for clearance (CL) of 0.14 L/h/kg and volume of distribution (V) of 0.5 L/kg. Body weight was confirmed as the significant covariate on CL and V. The optimal dosing regimens of 75 mg/kg/day and 80 mg/kg/day were recommended for this specific population.
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Infecções dos Tecidos Moles , Vancomicina , Humanos , Criança , Antibacterianos/farmacocinética , Infecções dos Tecidos Moles/tratamento farmacológico , Modelos BiológicosRESUMO
Coronavirus 2019 (COVID-19) is a complex disease that affects billions of people worldwide. Currently, effective etiological treatment of COVID-19 is still lacking; COVID-19 also causes damages to various organs that affects therapeutics and mortality of the patients. Surveillance of the treatment responses and organ injury assessment of COVID-19 patients are of high clinical value. In this study, we investigated the characteristic fragmentation patterns and explored the potential in tissue injury assessment of plasma cell-free DNA in COVID-19 patients. Through recruitment of 37 COVID-19 patients, 32 controls and analysis of 208 blood samples upon diagnosis and during treatment, we report gross abnormalities in cfDNA of COVID-19 patients, including elevated GC content, altered molecule size and end motif patterns. More importantly, such cfDNA fragmentation characteristics reflect patient-specific physiological changes during treatment. Further analysis on cfDNA tissue-of-origin tracing reveals frequent tissue injuries in COVID-19 patients, which is supported by clinical diagnoses. Hence, our work demonstrates and extends the translational merit of cfDNA fragmentation pattern as valuable analyte for effective treatment monitoring, as well as tissue injury assessment in COVID-19.
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COVID-19 , Ácidos Nucleicos Livres , Humanos , COVID-19/diagnóstico , Ácidos Nucleicos Livres/genéticaRESUMO
Inhibition of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and excessive inflammation is the current task in the prevention and treatment of corona vireus disease 2019 (COVID-19). Here, a dual-function circular aptamer-ASO chimera (circSApt-NASO) is designed to suppress SARS-CoV-2 replication and inflammation. The chemically unmodified circSApt-NASO exhibits high serum stability by artificial cyclization. It is also demonstrated that the SApt binding to spike protein enables the chimera to be efficiently delivered into the host cells expressing ACE2 along with the infection of SARS-CoV-2. Among them, the SApt potently inhibits spike-induced inflammation. The NASO targeting to silence N genes not only display robust anti-N-induced inflammatory activity, but also achieve efficient inhibition of SARS-CoV-2 replication. Overall, benefiting from the high stability of the cyclization, antispike aptamer-dependent, and viral infection-mediate targeted delivery, the circSApt-NASO displays robust potential against authentic SARS-CoV-2 and Omicron, providing a promising specific anti-inflammatory and antiproliferative reagent for therapeutic COVID-19.