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1.
Nature ; 625(7993): 148-156, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37993710

RESUMO

The continuing emergence of SARS-CoV-2 variants highlights the need to update COVID-19 vaccine compositions. However, immune imprinting induced by vaccination based on the ancestral (hereafter referred to as WT) strain would compromise the antibody response to Omicron-based boosters1-5. Vaccination strategies to counter immune imprinting are critically needed. Here we investigated the degree and dynamics of immune imprinting in mouse models and human cohorts, especially focusing on the role of repeated Omicron stimulation. In mice, the efficacy of single Omicron boosting is heavily limited when using variants that are antigenically distinct from WT-such as the XBB variant-and this concerning situation could be mitigated by a second Omicron booster. Similarly, in humans, repeated Omicron infections could alleviate WT vaccination-induced immune imprinting and generate broad neutralization responses in both plasma and nasal mucosa. Notably, deep mutational scanning-based epitope characterization of 781 receptor-binding domain (RBD)-targeting monoclonal antibodies isolated from repeated Omicron infection revealed that double Omicron exposure could induce a large proportion of matured Omicron-specific antibodies that have distinct RBD epitopes to WT-induced antibodies. Consequently, immune imprinting was largely mitigated, and the bias towards non-neutralizing epitopes observed in single Omicron exposures was restored. On the basis of the deep mutational scanning profiles, we identified evolution hotspots of XBB.1.5 RBD and demonstrated that these mutations could further boost the immune-evasion capability of XBB.1.5 while maintaining high ACE2-binding affinity. Our findings suggest that the WT component should be abandoned when updating COVID-19 vaccines, and individuals without prior Omicron exposure should receive two updated vaccine boosters.


Assuntos
Anticorpos Antivirais , Vacinas contra COVID-19 , COVID-19 , Imunização Secundária , Memória Imunológica , SARS-CoV-2 , Animais , Humanos , Camundongos , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/imunologia , COVID-19/prevenção & controle , COVID-19/virologia , Vacinas contra COVID-19/administração & dosagem , Vacinas contra COVID-19/imunologia , Epitopos de Linfócito B/imunologia , Memória Imunológica/imunologia , SARS-CoV-2/classificação , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Mutação
2.
Nature ; 614(7948): 521-529, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36535326

RESUMO

Continuous evolution of Omicron has led to a rapid and simultaneous emergence of numerous variants that display growth advantages over BA.5 (ref. 1). Despite their divergent evolutionary courses, mutations on their receptor-binding domain (RBD) converge on several hotspots. The driving force and destination of such sudden convergent evolution and its effect on humoral immunity remain unclear. Here we demonstrate that these convergent mutations can cause evasion of neutralizing antibody drugs and convalescent plasma, including those from BA.5 breakthrough infection, while maintaining sufficient ACE2-binding capability. BQ.1.1.10 (BQ.1.1 + Y144del), BA.4.6.3, XBB and CH.1.1 are the most antibody-evasive strains tested. To delineate the origin of the convergent evolution, we determined the escape mutation profiles and neutralization activity of monoclonal antibodies isolated from individuals who had BA.2 and BA.5 breakthrough infections2,3. Owing to humoral immune imprinting, BA.2 and especially BA.5 breakthrough infection reduced the diversity of the neutralizing antibody binding sites and increased proportions of non-neutralizing antibody clones, which, in turn, focused humoral immune pressure and promoted convergent evolution in the RBD. Moreover, we show that the convergent RBD mutations could be accurately inferred by deep mutational scanning profiles4,5, and the evolution trends of BA.2.75 and BA.5 subvariants could be well foreseen through constructed convergent pseudovirus mutants. These results suggest that current herd immunity and BA.5 vaccine boosters may not efficiently prevent the infection of Omicron convergent variants.


Assuntos
Anticorpos Antivirais , Deriva e Deslocamento Antigênicos , COVID-19 , Evolução Molecular , Imunidade Humoral , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Humanos , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Infecções Irruptivas/imunologia , Infecções Irruptivas/virologia , COVID-19/imunologia , COVID-19/virologia , Soroterapia para COVID-19 , SARS-CoV-2/química , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Domínios Proteicos/genética , Domínios Proteicos/imunologia , Deriva e Deslocamento Antigênicos/imunologia , Mutação
3.
Mol Cell ; 81(11): 2303-2316.e8, 2021 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-33991485

RESUMO

Glutaminase regulates glutaminolysis to promote cancer cell proliferation. However, the mechanism underlying glutaminase activity regulation is largely unknown. Here, we demonstrate that kidney-type glutaminase (GLS) is highly expressed in human pancreatic ductal adenocarcinoma (PDAC) specimens with correspondingly upregulated glutamine dependence for PDAC cell proliferation. Upon oxidative stress, the succinyl-coenzyme A (CoA) synthetase ADP-forming subunit ß (SUCLA2) phosphorylated by p38 mitogen-activated protein kinase (MAPK) at S79 dissociates from GLS, resulting in enhanced GLS K311 succinylation, oligomerization, and activity. Activated GLS increases glutaminolysis and the production of nicotinamide adenine dinucleotide phosphate (NADPH) and glutathione, thereby counteracting oxidative stress and promoting tumor cell survival and tumor growth in mice. In addition, the levels of SUCLA2 pS79 and GLS K311 succinylation, which were mutually correlated, were positively associated with advanced stages of PDAC and poor prognosis for patients. Our findings reveal critical regulation of GLS by SUCLA2-coupled GLS succinylation regulation and underscore the regulatory role of metabolites in glutaminolysis and PDAC development.


Assuntos
Carcinoma Ductal Pancreático/genética , Glutaminase/genética , Neoplasias Pancreáticas/genética , Succinato-CoA Ligases/genética , Animais , Carcinoma Ductal Pancreático/diagnóstico , Carcinoma Ductal Pancreático/enzimologia , Carcinoma Ductal Pancreático/mortalidade , Linhagem Celular Tumoral , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Glutaminase/metabolismo , Glutamina/metabolismo , Glutationa/metabolismo , Xenoenxertos , Humanos , Masculino , Camundongos , Camundongos Nus , NADP/metabolismo , Estresse Oxidativo , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/enzimologia , Neoplasias Pancreáticas/mortalidade , Fosforilação , Prognóstico , Processamento de Proteína Pós-Traducional , Transdução de Sinais , Succinato-CoA Ligases/metabolismo , Ácido Succínico/metabolismo , Análise de Sobrevida , Proteínas Quinases p38 Ativadas por Mitógeno/genética , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
4.
Nature ; 602(7898): 657-663, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35016194

RESUMO

The SARS-CoV-2 B.1.1.529 (Omicron) variant contains 15 mutations of the receptor-binding domain (RBD). How Omicron evades RBD-targeted neutralizing antibodies requires immediate investigation. Here we use high-throughput yeast display screening1,2 to determine the profiles of RBD escaping mutations for 247 human anti-RBD neutralizing antibodies and show that the neutralizing antibodies can be classified by unsupervised clustering into six epitope groups (A-F)-a grouping that is highly concordant with knowledge-based structural classifications3-5. Various single mutations of Omicron can impair neutralizing antibodies of different epitope groups. Specifically, neutralizing antibodies in groups A-D, the epitopes of which overlap with the ACE2-binding motif, are largely escaped by K417N, G446S, E484A and Q493R. Antibodies in group E (for example, S309)6 and group F (for example, CR3022)7, which often exhibit broad sarbecovirus neutralizing activity, are less affected by Omicron, but a subset of neutralizing antibodies are still escaped by G339D, N440K and S371L. Furthermore, Omicron pseudovirus neutralization showed that neutralizing antibodies that sustained single mutations could also be escaped, owing to multiple synergetic mutations on their epitopes. In total, over 85% of the tested neutralizing antibodies were escaped by Omicron. With regard to neutralizing-antibody-based drugs, the neutralization potency of LY-CoV016, LY-CoV555, REGN10933, REGN10987, AZD1061, AZD8895 and BRII-196 was greatly undermined by Omicron, whereas VIR-7831 and DXP-604 still functioned at a reduced efficacy. Together, our data suggest that infection with Omicron would result in considerable humoral immune evasion, and that neutralizing antibodies targeting the sarbecovirus conserved region will remain most effective. Our results inform the development of antibody-based drugs and vaccines against Omicron and future variants.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Evasão da Resposta Imune/imunologia , Testes de Neutralização , SARS-CoV-2/imunologia , Enzima de Conversão de Angiotensina 2/metabolismo , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/uso terapêutico , Anticorpos Neutralizantes/classificação , Anticorpos Antivirais/classificação , COVID-19/imunologia , COVID-19/virologia , Vacinas contra COVID-19/imunologia , Células Cultivadas , Convalescença , Epitopos de Linfócito B/química , Epitopos de Linfócito B/imunologia , Humanos , Soros Imunes/imunologia , Modelos Moleculares , Mutação , SARS-CoV-2/química , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/metabolismo
5.
Nature ; 608(7923): 593-602, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35714668

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron sublineages BA.2.12.1, BA.4 and BA.5 exhibit higher transmissibility than the BA.2 lineage1. The receptor binding and immune-evasion capability of these recently emerged variants require immediate investigation. Here, coupled with structural comparisons of the spike proteins, we show that BA.2.12.1, BA.4 and BA.5 (BA.4 and BA.5 are hereafter referred collectively to as BA.4/BA.5) exhibit similar binding affinities to BA.2 for the angiotensin-converting enzyme 2 (ACE2) receptor. Of note, BA.2.12.1 and BA.4/BA.5 display increased evasion of neutralizing antibodies compared with BA.2 against plasma from triple-vaccinated individuals or from individuals who developed a BA.1 infection after vaccination. To delineate the underlying antibody-evasion mechanism, we determined the escape mutation profiles2, epitope distribution3 and Omicron-neutralization efficiency of 1,640 neutralizing antibodies directed against the receptor-binding domain of the viral spike protein, including 614 antibodies isolated from people who had recovered from BA.1 infection. BA.1 infection after vaccination predominantly recalls humoral immune memory directed against ancestral (hereafter referred to as wild-type (WT)) SARS-CoV-2 spike protein. The resulting elicited antibodies could neutralize both WT SARS-CoV-2 and BA.1 and are enriched on epitopes on spike that do not bind ACE2. However, most of these cross-reactive neutralizing antibodies are evaded by spike mutants L452Q, L452R and F486V. BA.1 infection can also induce new clones of BA.1-specific antibodies that potently neutralize BA.1. Nevertheless, these neutralizing antibodies are largely evaded by BA.2 and BA.4/BA.5 owing to D405N and F486V mutations, and react weakly to pre-Omicron variants, exhibiting narrow neutralization breadths. The therapeutic neutralizing antibodies bebtelovimab4 and cilgavimab5 can effectively neutralize BA.2.12.1 and BA.4/BA.5, whereas the S371F, D405N and R408S mutations undermine most broadly sarbecovirus-neutralizing antibodies. Together, our results indicate that Omicron may evolve mutations to evade the humoral immunity elicited by BA.1 infection, suggesting that BA.1-derived vaccine boosters may not achieve broad-spectrum protection against new Omicron variants.


Assuntos
Anticorpos Antivirais , Deriva e Deslocamento Antigênicos , COVID-19 , Epitopos de Linfócito B , Tolerância Imunológica , Mutação , SARS-CoV-2 , Enzima de Conversão de Angiotensina 2/metabolismo , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Deriva e Deslocamento Antigênicos/genética , Deriva e Deslocamento Antigênicos/imunologia , COVID-19/imunologia , COVID-19/transmissão , COVID-19/virologia , Vacinas contra COVID-19/imunologia , Epitopos de Linfócito B/química , Epitopos de Linfócito B/genética , Epitopos de Linfócito B/imunologia , Humanos , Imunidade Humoral , Imunização Secundária , Testes de Neutralização , SARS-CoV-2/classificação , SARS-CoV-2/genética , SARS-CoV-2/imunologia , SARS-CoV-2/metabolismo , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/metabolismo
6.
Nature ; 580(7804): 530-535, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32322062

RESUMO

Cancer cells increase lipogenesis for their proliferation and the activation of sterol regulatory element-binding proteins (SREBPs) has a central role in this process. SREBPs are inhibited by a complex composed of INSIG proteins, SREBP cleavage-activating protein (SCAP) and sterols in the endoplasmic reticulum. Regulation of the interaction between INSIG proteins and SCAP by sterol levels is critical for the dissociation of the SCAP-SREBP complex from the endoplasmic reticulum and the activation of SREBPs1,2. However, whether this protein interaction is regulated by a mechanism other than the abundance of sterol-and in particular, whether oncogenic signalling has a role-is unclear. Here we show that activated AKT in human hepatocellular carcinoma (HCC) cells phosphorylates cytosolic phosphoenolpyruvate carboxykinase 1 (PCK1), the rate-limiting enzyme in gluconeogenesis, at Ser90. Phosphorylated PCK1 translocates to the endoplasmic reticulum, where it uses GTP as a phosphate donor to phosphorylate INSIG1 at Ser207 and INSIG2 at Ser151. This phosphorylation reduces the binding of sterols to INSIG1 and INSIG2 and disrupts the interaction between INSIG proteins and SCAP, leading to the translocation of the SCAP-SREBP complex to the Golgi apparatus, the activation of SREBP proteins (SREBP1 or SREBP2) and the transcription of downstream lipogenesis-related genes, proliferation of tumour cells, and tumorigenesis in mice. In addition, phosphorylation of PCK1 at Ser90, INSIG1 at Ser207 and INSIG2 at Ser151 is not only positively correlated with the nuclear accumulation of SREBP1 in samples from patients with HCC, but also associated with poor HCC prognosis. Our findings highlight the importance of the protein kinase activity of PCK1 in the activation of SREBPs, lipogenesis and the development of HCC.


Assuntos
Carcinoma Hepatocelular/metabolismo , Gluconeogênese , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Lipogênese , Neoplasias Hepáticas/metabolismo , Proteínas de Membrana/metabolismo , Fosfoenolpiruvato Carboxiquinase (GTP)/metabolismo , Animais , Carcinogênese , Carcinoma Hepatocelular/patologia , Proliferação de Células , Modelos Animais de Doenças , Retículo Endoplasmático/metabolismo , Complexo de Golgi/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/química , Neoplasias Hepáticas/patologia , Masculino , Proteínas de Membrana/química , Camundongos , Camundongos Nus , Oxisteróis/metabolismo , Fosforilação , Prognóstico , Ligação Proteica , Transporte Proteico , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 2/metabolismo
7.
EMBO J ; 40(18): e108249, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34296442

RESUMO

SARS-CoV-2 is an emerging coronavirus that causes dysfunctions in multiple human cells and tissues. Studies have looked at the entry of SARS-CoV-2 into host cells mediated by the viral spike protein and human receptor ACE2. However, less is known about the cellular immune responses triggered by SARS-CoV-2 viral proteins. Here, we show that the nucleocapsid of SARS-CoV-2 inhibits host pyroptosis by blocking Gasdermin D (GSDMD) cleavage. SARS-CoV-2-infected monocytes show enhanced cellular interleukin-1ß (IL-1ß) expression, but reduced IL-1ß secretion. While SARS-CoV-2 infection promotes activation of the NLRP3 inflammasome and caspase-1, GSDMD cleavage and pyroptosis are inhibited in infected human monocytes. SARS-CoV-2 nucleocapsid protein associates with GSDMD in cells and inhibits GSDMD cleavage in vitro and in vivo. The nucleocapsid binds the GSDMD linker region and hinders GSDMD processing by caspase-1. These insights into how SARS-CoV-2 antagonizes cellular inflammatory responses may open new avenues for treating COVID-19 in the future.


Assuntos
COVID-19/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Nucleocapsídeo/metabolismo , Proteínas de Ligação a Fosfato/metabolismo , Piroptose/fisiologia , SARS-CoV-2/metabolismo , Enzima de Conversão de Angiotensina 2/imunologia , Enzima de Conversão de Angiotensina 2/metabolismo , Animais , COVID-19/imunologia , COVID-19/patologia , COVID-19/virologia , Caspase 1/imunologia , Caspase 1/metabolismo , Células HEK293 , Interações Hospedeiro-Patógeno , Humanos , Inflamassomos/imunologia , Inflamassomos/metabolismo , Interleucina-1beta/imunologia , Interleucina-1beta/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/imunologia , Camundongos , Monócitos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Proteínas de Ligação a Fosfato/imunologia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/metabolismo , Células THP-1
8.
PLoS Pathog ; 19(12): e1011868, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38117863

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) XBB lineages have achieved dominance worldwide and keep on evolving. Convergent evolution of XBB lineages on the receptor-binding domain (RBD) L455F and F456L is observed, resulting in variants with substantial growth advantages, such as EG.5, FL.1.5.1, XBB.1.5.70, and HK.3. Here, we show that neutralizing antibody (NAb) evasion drives the convergent evolution of F456L, while the epistatic shift caused by F456L enables the subsequent convergence of L455F through ACE2 binding enhancement and further immune evasion. L455F and F456L evade RBD-targeting Class 1 public NAbs, reducing the neutralization efficacy of XBB breakthrough infection (BTI) and reinfection convalescent plasma. Importantly, L455F single substitution significantly dampens receptor binding; however, the combination of L455F and F456L forms an adjacent residue flipping, which leads to enhanced NAbs resistance and ACE2 binding affinity. The perturbed receptor-binding mode leads to the exceptional ACE2 binding and NAb evasion, as revealed by structural analyses. Our results indicate the evolution flexibility contributed by epistasis cannot be underestimated, and the evolution potential of SARS-CoV-2 RBD remains high.


Assuntos
Enzima de Conversão de Angiotensina 2 , COVID-19 , Humanos , Enzima de Conversão de Angiotensina 2/genética , SARS-CoV-2/genética , COVID-19/genética , Soroterapia para COVID-19 , Anticorpos Neutralizantes
9.
Cancer Sci ; 115(3): 905-915, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38148578

RESUMO

Chromatin remodelers are commonly altered in human cancer. The mutation of AT-rich interactive domain 1A (ARID1A) in gastric cancer (GC), a component of the SWI/SNF chromatin remodeling complex, was proven associated with treatment response in our previous study. However, ARID1A loss of function was caused not only by mutations but also copy number deletions. The clinicopathologic, genomic, and immunophenotypic correlates of ARID1A loss is largely uncharacterized in GC. Here, 819 patients with clinicopathological information and sequencing data or formalin-fixed paraffin-embedded tissues from four cohorts, Zhongshan Hospital (ZSHS) cohort (n = 375), The Cancer Genome Atlas (TCGA) cohort (n = 371), Samsung Medical Center (SMC) cohort (n = 53), and ZSHS immunotherapy cohort (n = 20), were enrolled. ARID1A loss was defined by genome sequencing or deficient ARID1A expression by immunohistochemistry. We found that ARID1A mutation and copy number deletion were enriched in GC with microsatellite instability (MSI) and chromosomal-instability (CIN), respectively. In the TCGA and ZSHS cohorts, only CIN GC with ARID1A loss could benefit from fluorouracil-based adjuvant chemotherapy. In the SMC and ZSHS immunotherapy cohorts, ARID1A loss exhibited a tendency of superior responsiveness and indicated favorable overall survival after anti-PD-1 immunotherapy. ARID1A-loss tumors demonstrated elevated mutation burden, neoantigen load, and interferon gamma pathway activation. Moreover, in CIN GC, ARID1A loss was correlated with higher homologous recombination deficiency. ARID1A loss defines a distinct subtype of GC characterized by high levels of genome instability, neoantigen formation, and immune activation. These tumors show sensitivity to both chemotherapy and anti-PD-1 immunotherapy. This study provides valuable insights for precision treatment strategies in GC.


Assuntos
Proteínas de Ligação a DNA , Neoplasias Gástricas , Humanos , Proteínas de Ligação a DNA/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Mutação
10.
Chemistry ; 30(11): e202301948, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38081801

RESUMO

The application of supramolecular templates in aligning atomically precise heterometal arrays is important for pursuing functional materials. Herein, we report that a bilayered supramolecular tri-deprotonated melamine dimer functions as an effective template in the construction of a heterometallic gold(I)-silver(I) macrocyclic cluster [µ6 -(C3 N6 H3 )3- ]2 -AuI 6 AgI 6 . X-ray single crystal structural analysis showed that a crown-like AuI 6 AgI 6 macrocycle is aligned around two parallelly stacked µ6 -(C3 N6 H3 )3- moieties hold together with π-π interactions. Theoretical calculations revealed that the [µ6 -(C3 N6 H3 )3- ]2 motif dominantly contributes to the near-occupied orbitals in the electronic structure, which is closely related to its luminescence properties. This work demonstrates that the supramolecular templates containing multiple symmetric binding sites may present a facile approach in the construction of functional metal clusters.

11.
Chemistry ; 30(16): e202303078, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38205968

RESUMO

We have previously reported the first formal hydroamination of enamines for the synthesis of chiral 1,2-diamines. Here, we describe: (i) the discovery, optimization, and substrate expansion of this reaction; (ii) a novel and straightforward protocol for the "click-type" synthesis of enamines in quantitative yield utilizing sodium sulfate in a dual role as an ancillary and dehydrating agent without the need for workup or purification; (iii) the application of this methodology to the first enantioselective synthesis of orthogonally protected 1,1'-(1-(4-fluorophenyl)ethane-1,2-diyl) piperazines, a scaffold for rapid lead optimization in drug discovery; (iv) a computational investigation into the mechanism and rationalization of the enantioselectivities of the reaction.

12.
Langmuir ; 40(6): 3248-3259, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38298055

RESUMO

Coalescence-induced jumping has promised a substantial reduction in the droplet detachment size and consequently shows great potential for heat-transfer enhancement in dropwise condensation. In this work, using molecular dynamics simulations, the evolution dynamics of the liquid bridge and the jumping velocity during coalescence-induced nanodroplet jumping under a perpendicular electric field are studied for the first time to further promote jumping. It is found that using a constant electric field, the jumping performance at the small intensity is weakened owing to the continuously decreased interfacial tension. There is a critical intensity above which the electric field can considerably enhance the stretching effect with a stronger liquid-bridge impact and, hence, improve the jumping performance. For canceling the inhibition effect of the interfacial tension under the condition of the weak electric field, a square-pulsed electric field with a paused electrical effect at the expansion stage of the liquid bridge is proposed and presents an efficient nanodroplet jumping even using the weak electric field.

13.
Langmuir ; 40(20): 10759-10768, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38712734

RESUMO

Bouncing dynamics of a trailing drop off-center impacting a leading drop with varying time intervals and Weber numbers are investigated experimentally. Whether the trailing drop impacts during the spreading or receding process of the leading drop is determined by the time interval. For a short time interval of 0.15 ≤ Δt* ≤ 0.66, the trailing drop impacts during the spreading of the leading drop, and the drops completely coalesce and rebound; for a large time interval of 0.66 < Δt* ≤ 2.21, the trailing drop impacts during the receding process, and the drops partially coalesce and rebound. Whether the trailing drop directly impacts the surface or the liquid film of the leading drop is determined by the Weber number. The trailing drop impacts the surface directly at moderate Weber numbers of 16.22 ≤ We ≤ 45.42, while it impacts the liquid film at large Weber numbers of 45.42 < We ≤ 64.88. Intriguingly, when the trailing drop impacts the surface directly or the receding liquid film, the contact time increases linearly with the time interval but independent of the Weber number; when the trailing drop impacts the spreading liquid film, the contact time suddenly increases, showing that the force of the liquid film of the leading drop inhibits the receding of the trailing drop. Finally, a theoretical model of the contact time for the drops is established, which is suitable for different impact scenarios of the successive off-center impact. This study provides a quantitative relationship to calculate the contact time of drops successively impacting a superhydrophobic surface, facilitating the design of anti-icing surfaces.

14.
J Org Chem ; 89(9): 6180-6192, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38632865

RESUMO

The photochemistry of noncovalent interactions to promote organic transformations is an emerging approach to providing fresh opportunities in synthetic chemistry. Generally, the external substance is necessary to add as an interaction partner, thereby sacrificing the atom economy of the reaction. Herein, we describe a catalyst-free and noncovalent interaction-mediated strategy to access the olefination of N-tosylhydrazones using acetone as a solvent and an interaction partner. This protocol also features broad substrate scope, excellent functional group compatibility, and mild reaction conditions without transition metals. Moreover, the gram-scale synthesis of olefins and the generation of pharmaceutical intermediates highlighted its practical applicability. Lastly, mechanistic studies indicate that the reaction was initiated via noncovalent interactions between acetone and N-tosylhydrazone anion, which is also supported by density functional theory calculations.

15.
Artigo em Inglês | MEDLINE | ID: mdl-38639613

RESUMO

Background: Upper gastrointestinal bleeding encompasses bleeding arising from esophageal, gastric, duodenal, or pancreaticobiliary lesions above the Treitz ligament. Research indicates a close association between improper diet and upper gastrointestinal bleeding. Objective: This study aims to investigate the application effects of individualized diet nursing combined with the modified Glasgow-Blatchford scoring system in patients with upper gastrointestinal bleeding. Design: A randomized controlled study was conducted. Setting: The study took place at the First Hospital of Hebei Medical University. Participants: From January 2021 to October 2022, 80 patients with upper gastrointestinal bleeding were selected at our hospital. Using a random number table, they were divided into a control group and an observation group, each comprising 40 cases. Interventions: The control group received routine nursing, while the observation group received individualized diet nursing based on the Glasgow-Blatchford score in addition to routine nursing. Primary Outcome Measures: (1) bleeding frequency, hemostasis time, and hospital stay; (2) re-bleeding rate; (3) Glasgow-Blatchford scores; (4) quality of life; and (5) nursing satisfaction. Results: In the observation group, bleeding frequency, hemostasis time, and hospital stay significantly reduced compared to the control (P < .05). Post-nursing, the observation group had a lower re-bleeding rate (χ2=11.25, P < .05). Before nursing, no statistical differences existed in Glasgow-Blatchford and quality of life scores between groups (P > .05). Post-nursing, both groups saw reduced Glasgow-Blatchford scores, more so in the observation group (P < .05). Quality of life scores increased in both, more notably in the observation group (P < .05). Overall nursing satisfaction was higher in the observation group (P < .05). Conclusions: Individualized diet nursing, based on the Glasgow-Blatchford score, improves cure rates and quality of life and warrants promotion.

16.
Molecules ; 29(10)2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38792220

RESUMO

The increasing prevalence of autoimmune diseases globally has prompted extensive research and the development of immunosuppressants. Currently, immunosuppressive drugs such as cyclosporine, rapamycin, and tacrolimus have been utilized in clinical practice. However, long-term use of these drugs may lead to a series of adverse effects. Therefore, there is an urgent need to explore novel drug candidates for treating autoimmune diseases. This review aims to find potential candidate molecules for natural immunosuppressive compounds derived from plants, animals, and fungi over the past decade. These compounds include terpenoids, alkaloids, phenolic compounds, flavonoids, and others. Among them, compounds 49, 151, 173, 200, 204, and 247 have excellent activity; their IC50 were less than 1 µM. A total of 109 compounds have good immunosuppressive activity, with IC50 ranging from 1 to 10 µM. These active compounds have high medicinal potential. The names, sources, structures, immunosuppressive activity, and the structure-activity relationship were summarized and analyzed.


Assuntos
Produtos Biológicos , Imunossupressores , Imunossupressores/farmacologia , Imunossupressores/química , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Humanos , Animais , Relação Estrutura-Atividade , Terpenos/química , Terpenos/farmacologia
17.
Angew Chem Int Ed Engl ; 63(1): e202315092, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-37943545

RESUMO

A PdII -catalyzed, domino enantioselective desymmetrizative coupling of 7-azabenzonorbornadienes with alkynylanilines is disclosed herein. This operationally simple transformation generates three covalent bonds and two contiguous stereocenters with excellent enantio- and diastereo-selectivity. The resulting functionalized indole-dihydronaphthalene-amine conjugates served as an appealing platform to streamline the diversity-oriented synthesis (DOS) of other valuable enantioenriched compounds. DFT calculations revealed that the two stabilizing non-covalent interactions contributed to the observed enantioselectivity.

18.
Angew Chem Int Ed Engl ; 63(8): e202316454, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38155472

RESUMO

In the chemistry community, catalytic asymmetric synthesis of furan-based compounds bearing both axial and central chirality has proven to be a significant but challenging issue owing to the importance and difficulty in constructing such frameworks. In this work, we have realized the first catalytic asymmetric synthesis of five-five-membered furan-based compounds bearing both axial and central chirality via organocatalytic asymmetric (2+4) annulation of achiral furan-indoles with 2,3-indolyldimethanols with uncommon regioselectivity. By this strategy, furan-indole compounds bearing both axial and central chirality were synthesized in high yields with excellent regio-, diastereo-, and enantioselectivities. Moreover, theoretical calculations were conducted to provide an in-depth understanding of the reaction pathway, activation mode, and the origin of the selectivity.

19.
Angew Chem Int Ed Engl ; 63(23): e202402038, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38412055

RESUMO

A novel enantioselective Tsuji-Trost-type cross coupling reaction between gem-difluorinated cyclopropanes and N-unprotected amino acid esters enabled by synergistic Pd/Ni/chiral aldehyde catalysis is presented herein. This transformation streamlined the diversity-oriented synthesis (DOS) of optically active α-quaternary α-amino acid esters bearing a linear 2-fluoroallylic motif, which served as an appealing platform for the construction of other valuable enantioenriched compounds. The key intermediates were confirmed by HRMS detection, while DFT calculations revealed that the excellent enantioselectivity was attributed to the stabilizing non-covalent interactions between the Pd(II)-π-fluoroallyl species and the Ni(II)-Schiff base complex.

20.
J Gene Med ; 25(11): e3549, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37271571

RESUMO

BACKGROUND: Kidney renal clear cell carcinoma (KIRC) is a prevalent type of urological malignancy. The present study aimed to predict biomarkers for KIRC. METHODS: We collected transcriptomic and clinical information for KIRC from The Cancer Genome Atlas and GSE22541 cohorts. RESULTS: Unsupervised clustering of 35 epithelial-mesenchymal transformation (EMT)-related differentially expressed gene profiles divided samples into two clusters with distinct immune characteristics. Six genes (IL20RB, DDC, ANKRD36BP2, F2RL1, TEK, and AMN) were found to construct a prognostic risk model using multivariate Cox regression analysis. Kaplan-Meier analysis suggested the better prognosis of the KIRC patients in the low-risk group than that in the high-risk group. Immune infiltration analyses was conducted using xCell and single-sample gene set enrichment analysis, indicating that the risk score was associated with the immune microenvironment of the KIRC. Prognostic marker gene-targeted medications with high drug sensitivity were predicted in KIRC patients. CONCLUSIONS: In summary, the present study identified IL20RB, DDC, ANKRD36BP2, F2RL1, TEK, and AMN as prognostic biomarkers, providing insight into immunotherapy and gene-targeted drugs of KIRC.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Humanos , Prognóstico , Transição Epitelial-Mesenquimal/genética , Carcinoma de Células Renais/genética , Neoplasias Renais/genética , Biomarcadores , Rim , Microambiente Tumoral
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