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1.
Cell ; 162(6): 1391-403, 2015 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-26359990

RESUMO

How metazoan mechanotransduction channels sense mechanical stimuli is not well understood. The NOMPC channel in the transient receptor potential (TRP) family, a mechanotransduction channel for Drosophila touch sensation and hearing, contains 29 Ankyrin repeats (ARs) that associate with microtubules. These ARs have been postulated to act as a tether that conveys force to the channel. Here, we report that these N-terminal ARs form a cytoplasmic domain essential for NOMPC mechanogating in vitro, mechanosensitivity of touch receptor neurons in vivo, and touch-induced behaviors of Drosophila larvae. Duplicating the ARs elongates the filaments that tether NOMPC to microtubules in mechanosensory neurons. Moreover, microtubule association is required for NOMPC mechanogating. Importantly, transferring the NOMPC ARs to mechanoinsensitive voltage-gated potassium channels confers mechanosensitivity to the chimeric channels. These experiments strongly support a tether mechanism of mechanogating for the NOMPC channel, providing insights into the basis of mechanosensitivity of mechanotransduction channels.


Assuntos
Proteínas de Drosophila/química , Proteínas de Drosophila/metabolismo , Drosophila/metabolismo , Mecanotransdução Celular , Canais de Potencial de Receptor Transitório/química , Canais de Potencial de Receptor Transitório/metabolismo , Animais , Drosophila/citologia , Drosophila/crescimento & desenvolvimento , Canal de Potássio Kv1.2/metabolismo , Larva/citologia , Larva/metabolismo , Microtúbulos/metabolismo , Estrutura Terciária de Proteína , Tato
2.
Cell ; 151(1): 111-22, 2012 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-23021219

RESUMO

Collapse of membrane lipid asymmetry is a hallmark of blood coagulation. TMEM16F of the TMEM16 family that includes TMEM16A/B Ca(2+)-activated Cl(-) channels (CaCCs) is linked to Scott syndrome with deficient Ca(2+)-dependent lipid scrambling. We generated TMEM16F knockout mice that exhibit bleeding defects and protection in an arterial thrombosis model associated with platelet deficiency in Ca(2+)-dependent phosphatidylserine exposure and procoagulant activity and lack a Ca(2+)-activated cation current in the platelet precursor megakaryocytes. Heterologous expression of TMEM16F generates a small-conductance Ca(2+)-activated nonselective cation (SCAN) current with subpicosiemens single-channel conductance rather than a CaCC. TMEM16F-SCAN channels permeate both monovalent and divalent cations, including Ca(2+), and exhibit synergistic gating by Ca(2+) and voltage. We further pinpointed a residue in the putative pore region important for the cation versus anion selectivity of TMEM16F-SCAN and TMEM16A-CaCC channels. This study thus identifies a Ca(2+)-activated channel permeable to Ca(2+) and critical for Ca(2+)-dependent scramblase activity during blood coagulation. PAPERFLICK:


Assuntos
Coagulação Sanguínea , Plaquetas/metabolismo , Cálcio/metabolismo , Proteínas de Transferência de Fosfolipídeos/metabolismo , Ambystoma mexicanum , Animais , Anoctamina-1 , Anoctaminas , Canais de Cloreto/metabolismo , Hemostasia , Metabolismo dos Lipídeos , Megacariócitos/metabolismo , Camundongos , Camundongos Knockout , Oócitos/metabolismo , Proteínas de Transferência de Fosfolipídeos/química , Proteínas de Transferência de Fosfolipídeos/genética , Xenopus
3.
Proc Natl Acad Sci U S A ; 119(34): e2204256119, 2022 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-35972965

RESUMO

Antibody therapeutics for the treatment of COVID-19 have been highly successful. However, the recent emergence of the Omicron variant has posed a challenge, as it evades detection by most existing SARS-CoV-2 neutralizing antibodies (nAbs). Here, we successfully generated a panel of SARS-CoV-2/SARS-CoV cross-neutralizing antibodies by sequential immunization of the two pseudoviruses. Of the potential candidates, we found that nAbs X01, X10, and X17 offer broad neutralizing potential against most variants of concern, with X17 further identified as a Class 5 nAb with undiminished neutralization against the Omicron variant. Cryo-electron microscopy structures of the three antibodies together in complex with each of the spike proteins of the prototypical SARS-CoV, SARS-CoV-2, and Delta and Omicron variants of SARS-CoV-2 defined three nonoverlapping conserved epitopes on the receptor-binding domain. The triple-antibody mixture exhibited enhanced resistance to viral evasion and effective protection against infection of the Beta variant in hamsters. Our findings will aid the development of antibody therapeutics and broad vaccines against SARS-CoV-2 and its emerging variants.


Assuntos
Anticorpos Neutralizantes , Anticorpos Antivirais , Epitopos , SARS-CoV-2 , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Vacinas contra COVID-19/imunologia , Sequência Conservada , Cricetinae , Microscopia Crioeletrônica , Epitopos/imunologia , Humanos , Camundongos , Testes de Neutralização , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/imunologia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/genética
4.
J Am Chem Soc ; 2024 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-38615326

RESUMO

Two-dimensional (2D) alloys hold great promise to serve as important components of 2D transistors, since their properties allow continuous regulation by varying their compositions. However, previous studies are mainly limited to the metallic/semiconducting ones as contact/channel materials, but very few are related to the insulating dielectrics. Here, we use a facile one-step chemical vapor deposition (CVD) method to synthesize ultrathin Bi2SixGe1-xO5 dielectric alloys, whose composition is tunable over the full range of x just by changing the relative ratios of the GeO2/SiO2 precursors. Moreover, their dielectric properties are highly composition-tunable, showing a record-high dielectric constant of >40 among CVD-grown 2D insulators. The vertically grown nature of Bi2GeO5 and Bi2SixGe1-xO5 enables polymer-free transfer and subsequent clean van der Waals integration as the high-κ encapsulation layer to enhance the mobility of 2D semiconductors. Besides, the MoS2 transistors using Bi2SixGe1-xO5 alloy as gate dielectrics exhibit a large Ion/Ioff (>108), ideal subthreshold swing of ∼61 mV/decade, and a small gate hysteresis (∼5 mV). Our work not only gives very few examples on controlled CVD growth of insulating dielectric alloys but also expands the family of 2D single-crystalline high-κ dielectrics.

5.
J Hepatol ; 80(5): 714-729, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38336348

RESUMO

BACKGROUND & AIMS: Mechanisms behind the impaired response of antigen-specific B cells to therapeutic vaccination in chronic hepatitis B virus (HBV) infection remain unclear. The development of vaccines or strategies to overcome this obstacle is vital for advancing the management of chronic hepatitis B. METHODS: A mouse model, denominated as E6F6-B, was engineered to feature a knock-in of a B-cell receptor (BCR) that specifically recognizes HBsAg. This model served as a valuable tool for investigating the temporal and spatial dynamics of humoral responses following therapeutic vaccination under continuous antigen exposure. Using a suite of immunological techniques, we elucidated the differentiation trajectory of HBsAg-specific B cells post-therapeutic vaccination in HBV carrier mice. RESULTS: Utilizing the E6F6-B transfer model, we observed a marked decline in antibody-secreting cells 2 weeks after vaccination. A dysfunctional and atypical pre-plasma cell population (BLIMP-1+ IRF4+ CD40- CD138- BCMA-) emerged, manifested by sustained BCR signaling. By deploying an antibody to purge persistent HBsAg, we effectively prompted the therapeutic vaccine to provoke conventional plasma cell differentiation. This resulted in an enhanced anti-HBs antibody response and facilitated HBsAg clearance. CONCLUSIONS: Sustained high levels of HBsAg limit the ability of therapeutic hepatitis B vaccines to induce the canonical plasma cell differentiation necessary for anti-HBs antibody production. Employing a strategy combining antibodies with vaccines can surmount this altered humoral response associated with atypical pre-plasma cells, leading to improved therapeutic efficacy in HBV carrier mice. IMPACT AND IMPLICATIONS: Therapeutic vaccines aimed at combatting HBV encounter suboptimal humoral responses in clinical settings, and the mechanisms impeding their effectiveness have remained obscure. Our research, utilizing the innovative E6F6-B mouse transfer model, reveals that the persistence of HBsAg can lead to the emergence of an atypical pre-plasma cell population, which proves to be relevant to the potency of therapeutic HBV vaccines. Targeting the aberrant differentiation process of these atypical pre-plasma cells stands out as a critical strategy to amplify the humoral response elicited by HBV therapeutic vaccines in carrier mouse models. This discovery suggests a compelling avenue for further study in the context of human chronic hepatitis B. Encouragingly, our findings indicate that synergistic therapy combining HBV-specific antibodies with vaccines offers a promising approach that could significantly advance the pursuit of a functional cure for HBV.


Assuntos
Hepatite B Crônica , Hepatite B , Camundongos , Humanos , Animais , Antígenos de Superfície da Hepatite B , Vírus da Hepatite B , Vacinas contra Hepatite B/uso terapêutico , Anticorpos Anti-Hepatite B , Diferenciação Celular , Hepatite B/prevenção & controle , Hepatite B/tratamento farmacológico
6.
BMC Plant Biol ; 24(1): 688, 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-39026161

RESUMO

BACKGROUND: Laccase (LAC) gene family plays a pivotal role in plant lignin biosynthesis and adaptation to various stresses. Limited research has been conducted on laccase genes in common beans. RESULTS: 29 LAC gene family members were identified within the common bean genome, distributed unevenly in 9 chromosomes. These members were divided into 6 distinct subclades by phylogenetic analysis. Further phylogenetic analyses and synteny analyses indicated that considerable gene duplication and loss presented throughout the evolution of the laccase gene family. Purified selection was shown to be the major evolutionary force through Ka / Ks. Transcriptional changes of PvLAC genes under low temperature and salt stress were observed, emphasizing the regulatory function of these genes in such conditions. Regulation by abscisic acid and gibberellins appears to be the case for PvLAC3, PvLAC4, PvLAC7, PvLAC13, PvLAC14, PvLAC18, PvLAC23, and PvLAC26, as indicated by hormone induction experiments. Additionally, the regulation of PvLAC3, PvLAC4, PvLAC7, and PvLAC14 in response to nicosulfuron and low-temperature stress were identified by virus-induced gene silence, which demonstrated inhibition on growth and development in common beans. CONCLUSIONS: The research provides valuable genetic resources for improving the resistance of common beans to abiotic stresses and enhance the understanding of the functional roles of the LAC gene family.


Assuntos
Lacase , Família Multigênica , Phaseolus , Filogenia , Estresse Fisiológico , Phaseolus/genética , Phaseolus/enzimologia , Phaseolus/fisiologia , Lacase/genética , Lacase/metabolismo , Estresse Fisiológico/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Genoma de Planta , Regulação da Expressão Gênica de Plantas , Genes de Plantas
7.
Small ; : e2401965, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38739099

RESUMO

Selective separation of ethylene and ethane (C2H4/C2H6) is a formidable challenge due to their close molecular size and boiling point. Compared to industry-used cryogenic distillation, adsorption separation would offer a more energy-efficient solution when an efficient adsorbent is available. Herein, a class of C2H4/C2H6 separation adsorbents, doped carbon molecular sieves (d-CMSs) is reported which are prepared from the polymerization and subsequent carbonization of resorcinol, m-phenylenediamine, and formaldehyde in ethanol solution. The study demonstrated that the polymer precursor themselves can be a versatile platform for modifying the pore structure and surface functional groups of their derived d-CMSs. The high proportion of pores centered at 3.5 Å in d-CMSs contributes significantly to achieving a superior kinetic selectivity of 205 for C2H4/C2H6 separation. The generated pyrrolic-N and pyridinic-N functional sites in d-CMSs contribute to a remarkable elevation of Henry selectivity to 135 due to the enhancement of the surface polarity in d-CMSs. By balancing the synergistic effects of kinetics and thermodynamics, d-CMSs achieve efficient separation of C2H4/C2H6. Polymer-grade C2H4 of 99.71% purity can be achieved with 75% recovery using the devised d-CMSs as reflected in a two-bed vacuum swing adsorption simulation.

8.
J Virol ; 97(2): e0168422, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36651747

RESUMO

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant is becoming a dominant circulator and has several mutations in the spike glycoprotein, which may cause shifts of immunogenicity, so as to result in immune escape and breakthrough infection among the already infected or vaccinated populations. It is unclear whether infection with Omicron could generate adequate cross-variant protection. To investigate this possibility, we used Syrian hamsters as an animal model for infection of SARS-CoV-2. The serum from Omicron BA.1 variant-infected hamsters showed a significantly lower neutralization effect against infection of the same or different SARS-CoV-2 variants than the serum from Beta variant-infected hamsters. Furthermore, the serum from Omicron BA.1 variant-infected hamsters were insufficient to protect against rechallenge of SARS-CoV-2 Prototype, Beta and Delta variants and itself. Importantly, we found that rechallenge with different SARS-CoV-2 lineages elevated cross-variant serum neutralization titers. Overall, our findings indicate a weakened immunogenicity feature of Omicron BA.1 variant that can be overcome by rechallenge of a different SARS-CoV-2 lineages. Our results may lead to a new guideline in generation and use of the vaccinations to combat the pandemic of SARS-CoV-2 Omicron variant and possible new variants. IMPORTANCE The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant causes breakthrough infections among convalescent patients and vaccinated populations. However, Omicron does not generate robust cross-protective responses. Here, we investigate whether heterologous SARS-CoV-2 challenge is able to enhance antibody response in a sensitive animal model, namely, Syrian hamster. Of note, a heterologous challenge of Beta and Omicron BA.1 variant significantly broadens the breadth of SARS-CoV-2 neutralizing responses against the prototype, Beta, Delta, and Omicron BA.1 variants. Our findings confirm that vaccination strategy with heterologous antigens might be a good option to protect against the evolving SARS-CoV-2.


Assuntos
COVID-19 , SARS-CoV-2 , Animais , Cricetinae , Anticorpos Neutralizantes , Anticorpos Antivirais , Antígenos Heterófilos/imunologia , Infecções Irruptivas , COVID-19/prevenção & controle , Mesocricetus , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/genética , Imunogenicidade da Vacina
9.
Pharmacol Res ; 202: 107127, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38438090

RESUMO

Circular RNAs (circRNAs) represent a novel class of non-coding RNAs that play significant roles in tumorigenesis and tumor progression. High-throughput sequencing of gastric cancer (GC) tissues has identified circRNA BIRC6 (circBIRC6) as a potential circRNA derived from the BIRC6 gene, exhibiting significant upregulation in GC tissues. The expression of circBIRC6 is notably elevated in GC patients. Functionally, it acts as a molecular sponge for miR-488, consequently upregulating GRIN2D expression and promoting GC proliferation, migration, and invasion. Moreover, overexpression of circBIRC6 leads to increased GRIN2D expression, which in turn enhances caveolin-1 (CAV1) expression, resulting in autophagy deficiency due to miR-488 sequestration. This cascade of events significantly influences tumorigenesis in vivo. Our findings collectively illustrate that the CircBIRC6-miR-488-GRIN2D axis fosters CAV1 expression in GC cells, thereby reducing autophagy levels. Both circBIRC6 and GRIN2D emerge as potential targets for treatment and independent prognostic factors for GC patients.


Assuntos
MicroRNAs , Neoplasias Gástricas , Humanos , Autofagia , Caveolina 1/genética , Caveolina 1/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/genética , Transformação Celular Neoplásica , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , MicroRNAs/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , RNA Circular/genética , RNA Circular/metabolismo , Neoplasias Gástricas/patologia
10.
Acta Pharmacol Sin ; 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38811774

RESUMO

Exercise training effectively relieves anxiety disorders via modulating specific brain networks. The role of post-translational modification of proteins in this process, however, has been underappreciated. Here we performed a mouse study in which chronic restraint stress-induced anxiety-like behaviors can be attenuated by 14-day persistent treadmill exercise, in association with dramatic changes of protein phosphorylation patterns in the medial prefrontal cortex (mPFC). In particular, exercise was proposed to modulate the phosphorylation of Nogo-A protein, which drives the ras homolog family member A (RhoA)/ Rho-associated coiled-coil-containing protein kinases 1(ROCK1) signaling cascade. Further mechanistic studies found that liver-derived kynurenic acid (KYNA) can affect the kynurenine metabolism within the mPFC, to modulate this RhoA/ROCK1 pathway for conferring stress resilience. In sum, we proposed that circulating KYNA might mediate stress-induced anxiety-like behaviors via protein phosphorylation modification within the mPFC, and these findings shed more insights for the liver-brain communications in responding to both stress and physical exercise.

11.
Cereb Cortex ; 33(10): 6063-6076, 2023 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-36562999

RESUMO

The ability to delay gratification is crucial for a successful and healthy life. An effective way for young children to learn this ability is to observe the action of adult models. However, the underlying neurocomputational mechanism remains unknown. Here, we tested the hypotheses that children employed either the simple imitation strategy or the goal-inference strategy when learning from adult models in a high-uncertainty context. Results of computational modeling indicated that children used the goal-inference strategy regardless of whether the adult model was their mother or a stranger. At the neural level, results showed that successful learning of delayed gratification was associated with enhanced interpersonal neural synchronization (INS) between children and the adult models in the dorsal lateral prefrontal cortex but was not associated with children's own single-brain activity. Moreover, the discounting of future reward's value obtained from computational modeling of the goal-inference strategy was positively correlated with the strength of INS. These findings from our exploratory study suggest that, even for 3-year-olds, the goal-inference strategy is used to learn delayed gratification from adult models, and the learning strategy is associated with neural interaction between the brains of children and adult models.


Assuntos
Desvalorização pelo Atraso , Adulto , Feminino , Humanos , Criança , Pré-Escolar , Recompensa , Córtex Pré-Frontal , Aprendizagem , Motivação
12.
J Virol ; 96(21): e0137322, 2022 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-36226984

RESUMO

Zika virus (ZIKV) is transmitted mostly via mosquito bites and no vaccine is available, so it may reemerge. We and others previously demonstrated that neonatal infection of ZIKV results in heart failure and can be fatal. Animal models implicated ZIKV involvement in viral heart diseases. It is unknown whether and how ZIKV causes heart failure in adults. Herein, we studied the effects of ZIKV infection on the heart function of adult A129 mice. First, we found that ZIKV productively infects the rat-, mouse-, or human-originated heart cell lines and caused ubiquitination-mediated degradation of and distortive effects on connexin 43 (Cx43) protein that is important for communications between cardiomyocytes. Second, ZIKV infection caused 100% death of the A129 mice with decreasing body weight, worsening health score, shrugging fur, and paralysis. The viral replication was detected in multiple organs. In searching for the viral effects on heart of the A129 mice, we found that ZIKV infection resulted in the increase of cardiac muscle enzymes, implicating a viral acute myocardial injury. ZIKV-caused heart injury was also demonstrated by electrocardiogram (ECG) showing widened and fragmented QRS waves, prolonged PR interval, and slower heart rate. The intercalated disc (ICD) between two cardiomyocytes was destroyed, as shown by the electronic microscopy, and the Cx43 distribution in the ICDs was less organized in the ZIKV-infected mice compared to that in the phosphate-buffered saline (PBS)-treated mice. Consistently, ZIKV productively infected the heart of A129 mice and decreased Cx43 protein. Therefore, we demonstrated that ZIKV infection caused heart failure, which might lead to fatal sequelae in ZIKV-infected A129 mice. IMPORTANCE Zika virus (ZIKV) is a teratogen causing devastating sequelae to the newborns who suffer a congenital ZIKV infection while it brings about only mild symptoms to the health-competent older children or adults. Mouse models have played an important role in mechanistic and pathogenic studies of ZIKV. In this study, we employed 3 to 4 week-old A129 mice for ZIKV infection. RT-qPCR assays discovered that ZIKV replicated in multiple organs, including the heart. As a result of ZIKV infection, the A129 mice experienced weight loss, health score worsening, paralysis, and deaths. We revealed that the ZIKV infection caused abnormal electrocardiogram presentations, increased cardiac muscle enzymes, downregulated Cx43, and destroyed the gap junction and the intercalated disc between the cardiomyocytes, implicating that ZIKV may cause an acute myocardial injury in A129 mice. Therefore, our data imply that ZIKV infection may jeopardize the immunocompromised population with a severe clinical consequence, such as heart defect.


Assuntos
Cardiopatias , Insuficiência Cardíaca , Infecção por Zika virus , Zika virus , Recém-Nascido , Criança , Animais , Camundongos , Humanos , Ratos , Adolescente , Conexina 43 , Miócitos Cardíacos/patologia , Modelos Animais de Doenças , Junções Comunicantes/patologia , Paralisia
13.
New Phytol ; 240(6): 2436-2454, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37840365

RESUMO

Seed size and weight are important factors that influence soybean yield. Combining the weighted gene co-expression network analysis (WGCNA) of 45 soybean accessions and gene dynamic changes in seeds at seven developmental stages, we identified candidate genes that may control the seed size/weight. Among these, a PLATZ-type regulator overlapping with 10 seed weight QTLs was further investigated. This zinc-finger transcriptional regulator, named as GmPLATZ, is required for the promotion of seed size and weight in soybean. The GmPLATZ may exert its functions through direct binding to the promoters and activation of the expression of cyclin genes and GmGA20OX for cell proliferation. Overexpression of the GmGA20OX enhanced seed size/weight in soybean. We further found that the GmPLATZ binds to a 32-bp sequence containing a core palindromic element AATGCGCATT. Spacing of the flanking sequences beyond the core element facilitated GmPLATZ binding. An elite haplotype Hap3 was also identified to have higher promoter activity and correlated with higher gene expression and higher seed weight. Orthologues of the GmPLATZ from rice and Arabidopsis play similar roles in seeds. Our study reveals a novel module of GmPLATZ-GmGA20OX/cyclins in regulating seed size and weight and provides valuable targets for breeding of crops with desirable agronomic traits.


Assuntos
Glycine max , Transcriptoma , Glycine max/genética , Transcriptoma/genética , Melhoramento Vegetal , Locos de Características Quantitativas , Sementes/genética
14.
J Med Virol ; 95(3): e28586, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36799264

RESUMO

RNA therapy represents a great way to precisely regulate cellular processes by modulating the gene expression. Despite this potential, a profound gap exists in our knowledge of how to subsequently deliver these RNAs into the specific target cells and turn therapeutically active RNAs into practical medicines. An advanced series of interlocked, thermodynamically self-regulated processes that enable the precise assembly of functional synthetic carriers of siRNA to the target cells in vivo was developed. To demonstrate the efficacy of this delivery system, we used it to treat human cytomegalovirus (HCMV) infection in a humanized mouse model. In this study, we use small interfering RNA (siRNA) and small complementary RNA (scRNA) to inhibit the expressions of two HCMV genes, IE1 and IE2. The auto-regulated nanocarrier polywraplex with core-shell structure was designed to condense and package these RNAs for delivering. To allow these particles recognize the HCMV-infected cells, a ligand was coupled on the surface of nanoparticle, which would specifically target the HCMV-encoded CX3 CL1 chemokine receptor presented in the HCMV-infected cells. The results demonstrated that the polywraplex conjugated with the target molecule CX3 CL1 effectively and specifically delivered the siRNA/scRNA to HCMV infected cells and inhibited virus growth in vitro and in vivo.


Assuntos
Infecções por Citomegalovirus , Proteínas Imediatamente Precoces , Ácidos Nucleicos , Animais , Camundongos , Humanos , Proteínas Imediatamente Precoces/genética , Transativadores/genética , Citomegalovirus/genética , Infecções por Citomegalovirus/terapia , Infecções por Citomegalovirus/genética , RNA Interferente Pequeno/genética
15.
J Med Virol ; 95(1): e28216, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36254681

RESUMO

Norovirus is the primary foodborne pathogenic agent causing viral acute gastroenteritis. It possesses broad genetic diversity and the prevalence of different genotypes varies substantially. However, the differences in RNA-dependent RNA polymerase (RdRp) activity among different genotypes of noroviruses remain unclear. In this study, the molecular mechanism of RdRp activity difference between the epidemic strain GII.17[P17] and the non-epidemic strain GII.8[P8] was characterized. By evaluating the evolutionary history of RdRp sequences with Markov Chain Monte Carlo method, the evolution rate of GII.17[P17] variants was higher than that of GII.8[P8] variants (1.22 × 10-3 nucleotide substitutions/site/year to 9.31 × 10-4 nucleotide substitutions/site/year, respectively). The enzyme catalytic reaction demonstrated that the Vmax value of GII.17[P17] RdRp was 2.5 times than that of GII.8[P8] RdRp. And the Km of GII.17[P17] and GII.8[P8] RdRp were 0.01 and 0.15 mmol/L, respectively. Then, GII.8[P8] RdRp fragment mutants (A-F) were designed, among which GII.8[P8]-A/B containing the conserved motif G/F were found to have significant effects on improving RdRp activity. The Km values of GII.8[P8]-A/B reached 0.07 and 0.06 mmol/L, respectively. And their Vmax values were 1.34 times than that of GII.8[P8] RdRp. In summary, our results suggested that RdRp activities were correlated with their epidemic characteristics. These findings will ultimately provide a better understanding in replication mechanism of noroviruses and development of antiviral drugs.


Assuntos
Infecções por Caliciviridae , Norovirus , Humanos , Norovirus/genética , Variação Genética , Infecções por Caliciviridae/epidemiologia , Genótipo , RNA Polimerase Dependente de RNA/genética , Nucleotídeos , Filogenia
16.
Liver Int ; 43(6): 1345-1356, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36810858

RESUMO

BACKGROUND AND AIMS: Human bone marrow mesenchymal stem cells (hBMSCs) are important for developing a dual-humanized mouse model to clarify disease pathogenesis. We aimed to elucidate the characteristics of hBMSC transdifferentiation into liver and immune cells. METHODS: A single type of hBMSCs was transplanted into immunodeficient Fah-/- Rag2-/- IL-2Rγc-/- SCID (FRGS) mice with fulminant hepatic failure (FHF). Liver transcriptional data from the hBMSC-transplanted mice were analysed to identify transdifferentiation with traces of liver and immune chimerism. RESULTS: Mice with FHF were rescued by implanted hBMSCs. Human albumin/leukocyte antigen (HLA) and CD45/HLA double-positive hepatocytes and immune cells were observed in the rescued mice during the initial 3 days. The transcriptomics analysis of liver tissues from dual-humanized mice identified two transdifferentiation phases (cellular proliferation at 1-5 days and cellular differentiation/maturation at 5-14 days) and ten cell lineages transdifferentiated from hBMSCs: human hepatocytes, cholangiocytes, stellate cells, myofibroblasts, endothelial cells and immune cells (T/B/NK/NKT/Kupffer cells). Two biological processes, hepatic metabolism and liver regeneration, were characterized in the first phase, and two additional biological processes, immune cell growth and extracellular matrix (ECM) regulation, were observed in the second phase. Immunohistochemistry verified that the ten hBMSC-derived liver and immune cells were present in the livers of dual-humanized mice. CONCLUSIONS: A syngeneic liver-immune dual-humanized mouse model was developed by transplanting a single type of hBMSC. Four biological processes linked to the transdifferentiation and biological functions of ten human liver and immune cell lineages were identified, which may help to elucidate the molecular basis of this dual-humanized mouse model for further clarifying disease pathogenesis.


Assuntos
Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Humanos , Camundongos , Animais , Células Endoteliais , Transcriptoma , Camundongos SCID , Fígado/patologia , Células-Tronco Mesenquimais/metabolismo
17.
Cell ; 134(6): 1019-29, 2008 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-18805094

RESUMO

Calcium-activated chloride channels (CaCCs) are major regulators of sensory transduction, epithelial secretion, and smooth muscle contraction. Other crucial roles of CaCCs include action potential generation in Characean algae and prevention of polyspermia in frog egg membrane. None of the known molecular candidates share properties characteristic of most CaCCs in native cells. Using Axolotl oocytes as an expression system, we have identified TMEM16A as the Xenopus oocyte CaCC. The TMEM16 family of "transmembrane proteins with unknown function" is conserved among eukaryotes, with family members linked to tracheomalacia (mouse TMEM16A), gnathodiaphyseal dysplasia (human TMEM16E), aberrant X segregation (a Drosophila TMEM16 family member), and increased sodium tolerance (yeast TMEM16). Moreover, mouse TMEM16A and TMEM16B yield CaCCs in Axolotl oocytes and mammalian HEK293 cells and recapitulate the broad CaCC expression. The identification of this new family of ion channels may help the development of CaCC modulators for treating diseases including hypertension and cystic fibrosis.


Assuntos
Canais de Cloreto/genética , Canais de Cloreto/metabolismo , Clonagem Molecular , Proteínas de Xenopus/genética , Proteínas de Xenopus/metabolismo , Xenopus laevis/metabolismo , Ambystoma/genética , Animais , Anoctamina-1 , Anoctaminas , Linhagem Celular , Canais de Cloreto/antagonistas & inibidores , Humanos , Camundongos , Dados de Sequência Molecular , Oócitos/metabolismo , Proteínas de Xenopus/antagonistas & inibidores , Xenopus laevis/genética
18.
Nature ; 547(7661): 118-122, 2017 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-28658211

RESUMO

Mechanosensory transduction for senses such as proprioception, touch, balance, acceleration, hearing and pain relies on mechanotransduction channels, which convert mechanical stimuli into electrical signals in specialized sensory cells. How force gates mechanotransduction channels is a central question in the field, for which there are two major models. One is the membrane-tension model: force applied to the membrane generates a change in membrane tension that is sufficient to gate the channel, as in the bacterial MscL channel and certain eukaryotic potassium channels. The other is the tether model: force is transmitted via a tether to gate the channel. The transient receptor potential (TRP) channel NOMPC is important for mechanosensation-related behaviours such as locomotion, touch and sound sensation across different species including Caenorhabditis elegans, Drosophila and zebrafish. NOMPC is the founding member of the TRPN subfamily, and is thought to be gated by tethering of its ankyrin repeat domain to microtubules of the cytoskeleton. Thus, a goal of studying NOMPC is to reveal the underlying mechanism of force-induced gating, which could serve as a paradigm of the tether model. NOMPC fulfils all the criteria that apply to mechanotransduction channels and has 29 ankyrin repeats, the largest number among TRP channels. A key question is how the long ankyrin repeat domain is organized as a tether that can trigger channel gating. Here we present a de novo atomic structure of Drosophila NOMPC determined by single-particle electron cryo-microscopy. Structural analysis suggests that the ankyrin repeat domain of NOMPC resembles a helical spring, suggesting its role of linking mechanical displacement of the cytoskeleton to the opening of the channel. The NOMPC architecture underscores the basis of translating mechanical force into an electrical signal within a cell.


Assuntos
Microscopia Crioeletrônica , Proteínas de Drosophila/ultraestrutura , Canais de Potencial de Receptor Transitório/ultraestrutura , Animais , Proteínas de Drosophila/química , Proteínas de Drosophila/metabolismo , Drosophila melanogaster , Lipídeos , Mecanotransdução Celular , Modelos Moleculares , Movimento , Domínios Proteicos , Canais de Potencial de Receptor Transitório/química , Canais de Potencial de Receptor Transitório/metabolismo
19.
BMC Nephrol ; 24(1): 57, 2023 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-36922779

RESUMO

OBJECTIVE: The study's purpose is to explore the link of serum albumin on renal progression in patients with chronic kidney disease (CKD). METHODS: This study was a secondary analysis of a prospective cohort study in which a total of 954 participants were non-selectively and consecutively collected from the research of CKD-ROUTE in Japan between November 2010 and December 2011. We evaluated the association between baseline ALB and renal prognosis (initiation of dialysis or 50% decline in eGFR from baseline) and renal function decline (annual eGFR decline) using the Cox proportional-hazards and linear regression models, respectively. We performed a number of sensitivity analyses to ensure the validity of the results. In addition, we performed subgroup analyses. RESULTS: The included patients had a mean age of (66.86 ± 13.41) years, and 522 (69.23%) were male. The mean baseline ALB and eGFR were (3.89 ± 0.59) g/dL and (33.43 ± 17.97) ml/min/1.73 m2. The annual decline in eGFR was 2.65 mL/min/1.73 m2/year. 218 (28.9%) individuals experienced renal prognosis during a median follow-up period of 36.0 months. The baseline ALB was inversely linked with renal prognosis (HR = 0.61, 95%CI: 0.45, 0.81) and renal function decline (ß = -1.41, 95%CI: -2.11, -0.72) after controlling for covariates. The renal prognosis and ALB had a non-linear connection, with ALB's inflection point occurring at 4.3 g/dL. Effect sizes (HR) were 0.42 (0.32, 0.56) and 6.11 (0.98, 38.22) on the left and right sides of the inflection point, respectively. There was also a non-linear relationship between ALB and renal function decline, and the inflection point of ALB was 4.1 g/dL. The effect sizes(ß) on the left and right sides of the inflection point were -2.79(-3.62, -1.96) and 0.02 (-1.97, 1.84), respectively. CONCLUSION: This study shows a negative and non-linear association between ALB and renal function decline as well as renal prognosis in Japanese CKD patients. When ALB is lower than 4.1 g/dL, ALB decline was closely related to poor renal prognosis and renal function decline. From a therapeutic point of view, reducing the decline in ALB makes sense for delaying CKD progression.


Assuntos
Insuficiência Renal Crônica , Albumina Sérica , Humanos , Masculino , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Feminino , Albumina Sérica/análise , Estudos Prospectivos , Progressão da Doença , Diálise Renal , Taxa de Filtração Glomerular , Fatores de Risco , Rim , Insuficiência Renal Crônica/terapia , Prognóstico
20.
Carcinogenesis ; 43(10): 980-987, 2022 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-36044738

RESUMO

Gastric cancer ranked third worldwide in terms of mortality. The immediate priority is to search for new prognosticative or therapeutic targets. This research aims to examine the function of the NADH:ubiquinone oxidoreductase subunit S4 (NDUFS4) in the malignant phenotype of gastric carcinoma. We analyzed the correlation between NDUFS4 expression and gastric cancer via bioinformatics analysis and cancer tissue microarray via immunohistochemistry. Also, we detected the phenotype change in gastric cancer cells after NDUFS4 was downregulated. NDUFS4's high expression in gastric cancer tissues showed an association with terminal TNM stage and unfavorable survival. Furthermore, downregulation of NDUFS4 decreased gastric cancer cell proliferation, migration and invasion. Nude mouse models revealed that NDUFS4 promotes tumor growth. This investigation highlights the prognostic role of NDUFS4 in gastric cancer. Our results also creatively ascertained NDUFS4 as a candidate for gastric cancer therapeutic targets.


Assuntos
Neoplasias Gástricas , Camundongos , Animais , Neoplasias Gástricas/patologia , Movimento Celular/genética , Proliferação de Células/genética , Prognóstico , Imuno-Histoquímica , Camundongos Nus , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Complexo I de Transporte de Elétrons/genética , Complexo I de Transporte de Elétrons/metabolismo
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