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1.
Plant J ; 119(3): 1369-1385, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38824648

RESUMO

Gibberellins (GAs) play crucial roles in regulating plant architecture and grain yield of crops. In rice, the inactivation of endogenous bioactive GAs and their precursors by GA 2-oxidases (GA2oxs) regulates stem elongation and reproductive development. However, the regulatory mechanisms of GA2ox gene expression, especially in rice reproductive organs, are unknown. The BEL1-like homeodomain protein OsBLH4, a negative regulatory factor for the rice OsGA2ox1 gene, was identified in this study. Loss of OsBLH4 function results in decreased bioactive GA levels and pleiotropic phenotypes, including reduced plant height, decreased grain number per panicle, and delayed heading date, as also observed in OsGA2ox1-overexpressing plants. Consistent with the mutant phenotype, OsBLH4 was predominantly expressed in shoots and young spikelets; its encoded protein was exclusively localized in the nucleus. Molecular analysis demonstrated that OsBLH4 directly bound to the promoter region of OsGA2ox1 to repress its expression. Genetic assays revealed that OsBLH4 acts upstream of OsGA2ox1 to control rice plant height, grain number, and heading date. Taken together, these results indicate a crucial role for OsBLH4 in regulating rice plant architecture and yield potential via regulation of bioactive GA levels, and provide a potential strategy for genetic improvements of rice.


Assuntos
Regulação da Expressão Gênica de Plantas , Giberelinas , Proteínas de Homeodomínio , Oryza , Proteínas de Plantas , Oryza/genética , Oryza/metabolismo , Oryza/crescimento & desenvolvimento , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Giberelinas/metabolismo , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas/genética , Grão Comestível/genética , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/metabolismo , Oxigenases de Função Mista
2.
N Engl J Med ; 387(24): 2232-2244, 2022 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-36507686

RESUMO

BACKGROUND: G protein-coupled receptor, family C, group 5, member D (GPRC5D) is an orphan receptor expressed in malignant plasma cells. Talquetamab, a bispecific antibody against CD3 and GPRC5D, redirects T cells to mediate killing of GPRC5D-expressing myeloma cells. METHODS: In a phase 1 study, we evaluated talquetamab administered intravenously weekly or every other week (in doses from 0.5 to 180 µg per kilogram of body weight) or subcutaneously weekly, every other week, or monthly (5 to 1600 µg per kilogram) in patients who had heavily pretreated relapsed or refractory multiple myeloma that had progressed with established therapies (a median of six previous lines of therapy) or who could not receive these therapies without unacceptable side effects. The primary end points - the frequency and type of dose-limiting toxic effects (study part 1 only), adverse events, and laboratory abnormalities - were assessed in order to select the recommended doses for a phase 2 study. RESULTS: At the data-cutoff date, 232 patients had received talquetamab (102 intravenously and 130 subcutaneously). At the two subcutaneous doses recommended for a phase 2 study (405 µg per kilogram weekly [30 patients] and 800 µg per kilogram every other week [44 patients]), common adverse events were cytokine release syndrome (in 77% and 80% of the patients, respectively), skin-related events (in 67% and 70%), and dysgeusia (in 63% and 57%); all but one cytokine release syndrome event were of grade 1 or 2. One dose-limiting toxic effect of grade 3 rash was reported in a patient who had received talquetamab at the 800-µg dose level. At median follow-ups of 11.7 months (in patients who had received talquetamab at the 405-µg dose level) and 4.2 months (in those who had received it at the 800-µg dose level), the percentages of patients with a response were 70% (95% confidence interval [CI], 51 to 85) and 64% (95% CI, 48 to 78), respectively. The median duration of response was 10.2 months and 7.8 months, respectively. CONCLUSIONS: Cytokine release syndrome, skin-related events, and dysgeusia were common with talquetamab treatment but were primarily low-grade. Talquetamab induced a substantial response among patients with heavily pretreated relapsed or refractory multiple myeloma. (Funded by Janssen Research and Development; MonumenTAL-1 ClinicalTrials.gov number, NCT03399799.).


Assuntos
Anticorpos Biespecíficos , Complexo CD3 , Mieloma Múltiplo , Receptores Acoplados a Proteínas G , Linfócitos T , Humanos , Anticorpos Biespecíficos/administração & dosagem , Anticorpos Biespecíficos/efeitos adversos , Anticorpos Biespecíficos/imunologia , Anticorpos Biespecíficos/uso terapêutico , Síndrome da Liberação de Citocina/induzido quimicamente , Síndrome da Liberação de Citocina/etiologia , Disgeusia/induzido quimicamente , Disgeusia/etiologia , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/imunologia , Mieloma Múltiplo/terapia , Recidiva Local de Neoplasia/tratamento farmacológico , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Receptores Acoplados a Proteínas G/imunologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Complexo CD3/antagonistas & inibidores , Complexo CD3/imunologia , Administração Intravenosa , Injeções Subcutâneas , Dermatopatias/induzido quimicamente , Dermatopatias/etiologia
3.
Microb Pathog ; 186: 106502, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38103581

RESUMO

Starvation stress can profoundly impact various physiological parameters in fish, including metabolism, behavior, meat quality, and reproduction. However, the repercussions of starvation on the intestinal microbiota of grass carp remain under-explored. This research aimed to elucidate the effects of a 28-day starvation period on the composition of the intestinal microbiota of grass carp. Tissue pathology assessments revealed significant alterations in the dimensions of intestinal villi in the foregut, midgut, and hindgut as compared to the controls. Specifically, dominant differences appeared in both the length and width of the villi. Moreover, a marked decline in the goblet cell population was observed across all the intestinal segments. 16S rDNA sequencing was used to investigate changes in the gut microbiota, which revealed distinct clustering patterns among the starved and control groups. While α diversity metrics remained consistent for the anterior intestine, significant deviations were recorded in the Shannon (midgut: ***P < 0.001; hindgut: *P < 0.05) and Simpson indices (midgut and hindgut: ***P < 0.001), demonstrating alterations in microbial richness and evenness. At the phylum level, Proteobacteria, Bacteroidetes, and Fusobacteria emerged as dominant groups post-starvation. Other bacterial taxa, such as Actinobacteria and Verrucomicrobia, decreased, whereas Bacteroidetes and Firmicutes showed a small increase. In summation, starvation induces considerable morphological and microbial shifts in the grass carp intestine, and thus, this study offers valuable insights into their cultivation strategies.


Assuntos
Carpas , Animais , Bactérias/genética , Intestinos/microbiologia , Proteobactérias/genética , Bacteroidetes
4.
J Org Chem ; 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38950123

RESUMO

In the past eight years, the selective cross-coupling of amides by N-C(O) bond activation has emerged as a highly attractive manifold for the manipulation of traditionally unreactive amide bonds. In this Special Issue on Next-Generation Cross-Coupling Chemistry, we report the Suzuki-Miyaura and Buchwald-Hartwig cross-coupling of amides by selective N-C(O) cleavage catalyzed by bench-stable, well-defined carboxylate Pd(II)-NHC (NHC = N-heterocyclic carbene) catalysts {[(NHC)Pd(O2CR)2]}. This class of Pd(II)-NHCs promotes cross-coupling under exceedingly mild room-temperature conditions owing to the facile dissociation of the carboxylate ligands to form the active complex. These readily accessible Pd(II)-NHC precatalysts show excellent functional group tolerance and are compatible with a broad range of amide activating groups. Considering the mild conditions for the cross-coupling and the facile access to carboxylate Pd(II)-NHC complexes, we anticipate that this class of bench-stable complexes will find wide application in the activation of amide N-C(O) and related acyl X-C(O) bonds.

5.
Fish Shellfish Immunol ; 149: 109474, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38513914

RESUMO

Grass carp hemorrhagic disease is a significant problem in grass carp aquaculture. It releases highly oxidizing hemoglobin (Hb) into tissues, induces rapid autooxidation, and subsequently discharges cytotoxic reactive oxygen species (ROS). However, the mechanism underlying Hb damage to the teleost remains unclear. Here, we employed ferrylHb and heme to incubate L8824 (grass carp liver) cells and quantitatively analyzed the corresponding molecular regulation using the RNA-seq method. Based on the RNA-seq analysis data, after 12 h of incubation of the L8824 cells with ferrylHb, a total of 3738 differentially expressed genes (DEGs) were identified, 1824 of which were upregulated, and 1914 were downregulated. A total of 4434 DEGs were obtained in the heme treated group, with 2227 DEGs upregulated and 2207 DEGs downregulated. KEGG enrichment analysis data revealed that the incubation of ferrylHb and heme significantly activated the pathways related to Oxidative Phosphorylation, Autophagy, Mitophagy and Protein Processing in Endoplasmic Reticulum. The genes associated with NF-κB, autophagy and apoptosis pathways were selected for further validation by quantitative real-time RT-PCR (qRT-PCR). The results were consistent with the RNA-seq data. Taken together, the incubation of Hb and heme induced the molecular regulation of L8824, which consequently led to programmed cell death through multiple pathways.


Assuntos
Carpas , Hemoglobinas , Hepatócitos , Animais , Carpas/imunologia , Carpas/genética , Inflamação/veterinária , Inflamação/imunologia , Morte Celular , Doenças dos Peixes/imunologia , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Regulação da Expressão Gênica/imunologia , Regulação da Expressão Gênica/efeitos dos fármacos
6.
Fish Shellfish Immunol ; 150: 109596, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38692380

RESUMO

Streptococcosis, the most common bacterial disease of fish in recent years, is highly infectious and lethal, and has become an important factor hindering the healthy and sustainable development of aquaculture. Chicken egg yolk antibody (IgY) has the advantages of high antigen specificity, inexpensive and easy to obtain, simple preparation, no toxic side effects, and in line with animal welfare, which is a green and safe alternative to antibiotics. In this study, the potential of specific IgY in the treatment of gastrointestinal pathogens was explored by observing the effects of specific IgY on intestinal flora, pathological tissue, apoptosis, oxidative stress, and inflammatory response of tilapia. We used the specific IgY prepared in the early stage to feed tilapia for 10 days, and then the tilapia was challenged with Streptococcus agalactiae. The results showed that feeding IgY before challenge had a small effect on the intestinal flora, and after challenge specific IgY decreased the proportion of Streptococcus and increased the diversity of the intestinal flora; in histopathology, specific IgY decreased tissue damage and maintained the integrity of tissue structure. Further study found that specific IgY can reduce intestinal epithelial cell apoptosis and reduce caspase activity; at the same time, the content of MDA was decreased, and the activities of SOD, CAT, GSH-Px and GR were increased. In addition, specific IgY can down-regulate the expression levels of IL-8 and TNF-α genes and up-regulate the expression levels of IL-10 and TGF-ß. The results of this study showed that specific IgY could improve the intestinal flora of tilapia infected with Streptococcus agalactiae, reduce intestinal cell apoptosis, oxidative stress injury and inflammatory response, thereby reducing tissue damage and protecting the health of tilapia. Overall, specific IgY can be further explored as a potential antibiotic alternative for gastrointestinal pathogen infections.


Assuntos
Ração Animal , Apoptose , Galinhas , Ciclídeos , Doenças dos Peixes , Microbioma Gastrointestinal , Imunoglobulinas , Intestinos , Estresse Oxidativo , Infecções Estreptocócicas , Streptococcus agalactiae , Animais , Streptococcus agalactiae/fisiologia , Infecções Estreptocócicas/veterinária , Infecções Estreptocócicas/imunologia , Estresse Oxidativo/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Imunoglobulinas/imunologia , Ciclídeos/imunologia , Galinhas/imunologia , Doenças dos Peixes/imunologia , Microbioma Gastrointestinal/efeitos dos fármacos , Ração Animal/análise , Intestinos/imunologia , Dieta/veterinária , Gema de Ovo/imunologia , Gema de Ovo/química
7.
Fish Shellfish Immunol ; 154: 109923, 2024 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-39326687

RESUMO

IgY is an immunoglobulin primarily found in the serum and egg yolk of birds, amphibians, and reptiles. Recent years, IgY is considered to have a good application prospect in the immunodiagnostics and passive immunotherapy of aquatic diseases. In this study, we prepared a specific IgY against Streptococcus agalactiae in tilapia after immunizing the hens for 4 times. The result of ELISA detection showed that the IgY titers in water-soluble fraction (WSF) after 6 weeks of immunization reached 1:51200 and last for 4 weeks. Western blot (WB) analysis data showed that the specific IgY could recognize the target band, the specific IgY showed a concentration-dependent inhibitory effect on the growth of S. agalactiae, altered cell wall structure and aggluted of S. agalactiae. The quantitative reverse transcription PCR (qRT-PCR) analysis data suggested that the specific IgY downregulated the expression of pro-inflammatory factors (IL-8, TNF-α), upregulated the anti-inflammatory factors (IL-10, TGF-ß). In addition, the histopathological results showed that the specific IgY significantly decreased the pathological manifestations, dramatically improved the survival rates of tilapia in injection, feeding, and immersion experiments. Collectively, our findings demonstrated that the broad potential of specific IgY for the prevention and treatment of S. agalactiae infection in tilapia.

8.
Fish Shellfish Immunol ; 149: 109526, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38554743

RESUMO

In teleost blood, red blood cells (RBCs) are the most common type of cell, and they differ from mammalian RBCs in having a nucleus and other organelles. As nucleated cells, teleost RBCs contribute to the immune response against pathogens, but their antibacterial mechanism remains unclear. Here, we utilized RNA-Seq to analyze gene expression patterns of grass carp (Ctenopharyngodon idellus) RBCs (GcRBCs) stimulated by Aeromonas hydrophila, Escherichia coli, and Staphylococcus aureus. Our transcriptomic data showed that bacterial stimulation generated many differentially expressed genes (DEGs). Furthermore, several inflammatory pathways responded to bacterial activation, and the TLR, IL-17, and tumor necrosis factor (TNF) signaling pathways were significantly activated based on Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. Furthermore, the findings of qRT-PCR showed markedly elevated expression of various cytokines, including IL-1ß, IL4, IL6, IL8, IL12, and TNFα, in GcRBCs after incubation with bacteria. Reactive oxygen species (ROS) production in GcRBCs was markedly increased after the cells were stimulated with the three bacteria, and the expression of superoxide dismutase, glutathione peroxidase, and antioxidant enzymes, including catalase, was altered. Flow cytometry analysis showed that the apoptosis rate of GcRBCs was enhanced after stimulation with the three bacteria for different times. In summary, our findings reveal that bacterial stimulation activates the immune response of GcRBCs by regulating ROS release, cytokine expression, and the antioxidant system, leading to apoptosis of GcRBCs.


Assuntos
Aeromonas hydrophila , Carpas , Eritrócitos , Escherichia coli , Doenças dos Peixes , Infecções por Bactérias Gram-Negativas , Imunidade Inata , Animais , Carpas/imunologia , Carpas/genética , Doenças dos Peixes/imunologia , Eritrócitos/imunologia , Aeromonas hydrophila/fisiologia , Imunidade Inata/genética , Escherichia coli/imunologia , Escherichia coli/fisiologia , Infecções por Bactérias Gram-Negativas/imunologia , Infecções por Bactérias Gram-Negativas/veterinária , Staphylococcus aureus/fisiologia , Staphylococcus aureus/imunologia , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Infecções Estafilocócicas/imunologia , Infecções Estafilocócicas/veterinária , Transcriptoma/imunologia , Infecções por Escherichia coli/imunologia , Infecções por Escherichia coli/veterinária
9.
Fish Shellfish Immunol ; 150: 109603, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38704112

RESUMO

Infection-induced hemolysis results in intravascular hemolysis, which releases hemoglobin (Hb) into the tissues. Free Hb exhibits cytotoxic, oxidative, and pro-inflammatory effects, leading to systemic inflammation, vascular constriction dysfunction, thrombosis, and proliferative vascular lesions. Currently, the impact of intravascular hemolysis on the middle kidney in fish is unclear. Here, the injection of phenylhydrazine (PHZ) was used to establish a persistent hemolysis model in grass carp. The determination results revealed that the PHZ-induced hemolysis caused conspicuous tissue damage in the kidneys of grass carp, increased the levels of Cr in the serum and the expression indicators of kidney injury-related genes in the middle kidney. Prussian blue staining indicated that PHZ-induced hemolysis significantly increased the deposition of iron ions in the kidneys of grass carp, and activated the expression levels of iron metabolism-related genes. The results of oxidative damage-related experiments indicate that under PHZ treatment, the activity of middle kidney cells decreases, and the production of oxidative damage markers malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE) increases, simultaneously inhibiting the activity of antioxidant enzymes and upregulating the transcription levels of antioxidant enzyme-related genes. Additionally, the analysis of inflammatory factors revealed a significant upregulation of genes associated with inflammation induced by PHZ-induced hemolysis. The transcriptome analysis was performed to further explore the molecular regulatory effects of hemolysis on tissues, the analysis revealed the treatment of PHZ activated various of programmed cell death (PCD) pathways, including ferroptosis, apoptosis, and autophagy. In summary, this study found that sustained hemolysis in fish results in Hb and iron ion deposition in middle kidney, promoting oxidative damage, ultimately inducing various forms of PCD.


Assuntos
Carpas , Doenças dos Peixes , Hemólise , Animais , Carpas/imunologia , Doenças dos Peixes/imunologia , Fenil-Hidrazinas/efeitos adversos , Fenil-Hidrazinas/toxicidade , Nefropatias/veterinária , Nefropatias/etiologia , Nefropatias/imunologia , Rim/imunologia , Rim/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos
10.
Fish Shellfish Immunol ; 145: 109315, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38134975

RESUMO

In contrast to mammalian red blood cells (RBCs), Osteichthyes RBCs contain a nucleus and organelles, suggesting the involvement of more intricate mechanisms, particularly in the context of ferroptosis. In this study, we utilized RBCs from Clarias fuscus (referred to as Cf-RBCs) as a model system. We conducted RNA-seq analysis to quantify gene expression levels in Cf-RBCs after exposure to both Aeromonas hydrophila and lipopolysaccharides. Our analysis unveiled 1326 differentially expressed genes (DEGs) in Cf-RBCs following 4 h of incubation with A. hydrophila, comprising 715 and 611 genes with upregulated and downregulated expression, respectively. These DEGs were further categorized into functional clusters: 292 related to cellular processes, 241 involved in environmental information processing, 272 associated with genetic information processing, and 399 linked to organismal systems. Additionally, notable changes were observed in genes associated with the autophagy pathway at 4 h, and alterations in the ferroptosis pathway were observed at 8 h following A. hydrophila incubation. To validate these findings, we assessed the expression of cytokines (DMT1, TFR1, LC3, and GSS). All selected genes were significantly upregulated after exposure to A. hydrophila. Using flow cytometry, we evaluated the extent of ferroptosis, and the group incubated with A. hydrophila for 8 h exhibited higher levels of lipid peroxidation compared with the 4-h incubation group, even under baseline conditions. An evaluation of the glutathione redox system through GSSG/GSH ratios indicated an increased ratio in Cf-RBCs after exposure to A. hydrophila. In summary, our data suggest that A. hydrophila may induce ferroptosis in Cf-RBCs, potentially by triggering the cystine/glutamate antiporter system (system XC-), while Cf-RBCs counteract ferroptosis through the regulation of the glutathione redox system. These findings contribute to our understanding of the iron overload mechanism in Osteichthyes RBCs, provide insights into the management of bacterial diseases in Clarias fuscus, and offer potential strategies to mitigate economic losses in aquaculture.


Assuntos
Aeromonas hydrophila , Infecções por Bactérias Gram-Negativas , Animais , Aeromonas hydrophila/fisiologia , Apoptose , Eritrócitos , Glutationa , Infecções por Bactérias Gram-Negativas/microbiologia , Mamíferos
11.
Angew Chem Int Ed Engl ; 63(8): e202318703, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38135660

RESUMO

IMes (IMes=1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene) and IPr (IPr=1,3- bis(2,6-diisopropylphenyl)imidazol-2-ylidene) represent by far the most frequently used N-heterocyclic carbene ligands in homogeneous catalysis, however, despite numerous advantages, these ligands are limited by the lack of steric flexibility of catalytic pockets. We report a new class of unique unsymmetrical N-heterocyclic carbene ligands that are characterized by freely-rotatable N-aromatic wingtips in the imidazol-2-ylidene architecture. The combination of rotatable N-CH2 Ar bond with conformationally-fixed N-Ar linkage results in a highly modular ligand topology, entering the range of geometries inaccessible to IMes and IPr. These ligands are highly reactive in Cu(I)-catalyzed ß-hydroboration, an archetypal borylcupration process that has had a transformative impact on the synthesis of boron-containing compounds. The most reactive Cu(I)-NHC in this class has been commercialized in collaboration with MilliporeSigma to enable broad access of the synthetic chemistry community. The ligands gradually cover %Vbur geometries ranging from 37.3 % to 52.7 %, with the latter representing the largest %Vbur described for an IPr analogue, while retaining full flexibility of N-wingtip. Considering the modular access to novel geometrical space in N-heterocyclic carbene catalysis, we anticipate that this concept will enable new opportunities in organic synthesis, drug discovery and stabilization of reactive metal centers.

12.
J Org Chem ; 88(15): 10858-10868, 2023 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-37467445

RESUMO

The Suzuki-Miyaura cross-coupling of amides by selective N-C acyl bond cleavage represents a powerful tool for constructing biaryl ketones from historically inert amide bonds. These amide bond activation reactions hinge upon efficient oxidative addition of the N-C acyl bond to Pd(0). However, in contrast to the well-researched activation of aryl halides by C(sp2)-X oxidative addition, very few studies on the mechanism of C(acyl)-N bond oxidative addition and catalyst effect have been reported. Herein, we report a study on [Pd(NHC)(sulfide)Cl2] catalysts in amide N-C bond activation. These readily prepared, well-defined, air- and moisture-stable Pd(II)-NHC catalysts feature SMe2 (DMS = dimethylsulfide) or S(CH2CH2)2 (THT = tetrahydrothiophene) as ancillary ligands. The reaction development, kinetic studies, and reaction scope are presented. Extensive DFT studies were conducted to gain insight into the mechanism of C(acyl)-N bond oxidative addition and catalyst activation. We expect that [Pd(NHC)(sulfide)Cl2] precatalysts featuring sulfides as well-defined, readily accessible ancillary ligands will find application in C(acyl)-X bond activation in organic synthesis and catalysis.

13.
Molecules ; 28(3)2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36770617

RESUMO

Silver-NHC (NHC = N-heterocyclic carbene) complexes play a special role in the field of transition-metal complexes due to (1) their prominent biological activity, and (2) their critical role as transfer reagents for the synthesis of metal-NHC complexes by transmetalation. However, the application of silver-NHCs in catalysis is underdeveloped, particularly when compared to their group 11 counterparts, gold-NHCs (Au-NHC) and copper-NHCs (Cu-NHC). In this Special Issue on Featured Reviews in Organometallic Chemistry, we present a comprehensive overview of the application of silver-NHC complexes in the p-activation of alkynes. The functionalization of alkynes is one of the most important processes in chemistry, and it is at the bedrock of organic synthesis. Recent studies show the significant promise of silver-NHC complexes as unique and highly selective catalysts in this class of reactions. The review covers p-activation reactions catalyzed by Ag-NHCs since 2005 (the first example of p-activation in catalysis by Ag-NHCs) through December 2022. The review focuses on the structure of NHC ligands and p-functionalization methods, covering the following broadly defined topics: (1) intramolecular cyclizations; (2) CO2 fixation; and (3) hydrofunctionalization reactions. By discussing the role of Ag-NHC complexes in the p-functionalization of alkynes, the reader is provided with an overview of this important area of research and the role of Ag-NHCs to promote reactions that are beyond other group 11 metal-NHC complexes.

14.
Rheumatology (Oxford) ; 62(1): 270-280, 2022 12 23.
Artigo em Inglês | MEDLINE | ID: mdl-35552653

RESUMO

OBJECTIVES: To define the pattern of body composition and alteration after treatment of patients with newly diagnosed idiopathic inflammatory myopathies (IIMs) using DXA. METHODS: DXA was used to obtain regional and whole-body measurements of fat mass and lean tissue mass (LTM) in 50 patients with newly diagnosed IIM and matched controls. The DXA indices of fat mass and LTM were calculated. The analyses included correlations between DXA indices and clinical parameters [manual muscle test (MMT), Myositis Damage Index (MDI), Myositis Intention-to-Treat Activities Index (MITAX), handgrip, percentage forced vital capacity (%FVC) and creatine kinase level], comparison between patients with IIM and controls, comparison between IIM subgroups, receiver operating characteristic (ROC) analysis, and comparison of body composition before and after treatment. RESULTS: DXA LTM measurements were significantly correlated with MMT, MDI-muscle, handgrip strength, and %FVC. Patients with IIM had decreased LTM of the upper limbs and appendicular region. Male patients with IIM had significantly decreased LTM in the upper and lower limbs, whereas female patients with IIM had significantly decreased LTM in the upper limbs. Patients with IIM with anti-SRP seropositivity had lower LTM than patients with anti-SRP seronegativity. In ROC analysis, the DXA LTM indices presented good diagnostic values for distinguishing patients with newly diagnosed IIM from healthy controls. After treatment, the LTM of the upper limbs and appendicular region significantly increased. CONCLUSION: DXA is an attractive method for the evaluation of patients with newly diagnosed IIM as well as a new way of monitoring disease conditions.


Assuntos
Força da Mão , Miosite , Humanos , Masculino , Feminino , Composição Corporal/fisiologia , Miosite/diagnóstico por imagem , Extremidade Superior , Extremidade Inferior
15.
J Org Chem ; 87(22): 15250-15260, 2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36305513

RESUMO

A highly efficient protocol for the Suzuki-Miyaura cross-coupling of aryl fluorosulfonates by selective -OF cleavage using well-defined, air- and moisture-stable NHC-Pd(II) chloro dimers is presented. The reaction proceeds in excellent yields and with broad functional group tolerance using 0.10-0.20 mol % of [Pd] in the presence of mild K3PO4 base under aqueous conditions. A variety of sensitive functional groups are tolerated in this operationally trivial protocol for C-O bond activation. Selectivity studies and gram scale cross-coupling are presented. The method advances well-defined and highly reactive Pd(II)-NHCs to the cross-coupling of readily available, orthogonal, and bench-stable fluorosulfonates as aryl halide surrogates.

16.
Am J Respir Cell Mol Biol ; 65(6): 581-592, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34186014

RESUMO

The airway epithelium is a central modulator of innate and adaptive immunity in the lung. IL17A expression was found to be increased in the airway epithelium; however, the role of epithelium-derived IL17A in chronic obstructive pulmonary disease (COPD) remains unclear. In this study, we aimed to determine whether epithelium-derived IL17A regulates inflammation and mucus hyperproduction in COPD by using a cultured human bronchial epithelial (HBE) cell line in vitro and an airway epithelium IL17A-specific knockout mouse in vivo. Increased IL17A expression was observed in the mouse airway epithelium upon cigarette smoke (CS) exposure or in a mouse model of COPD that was induced by using CS and Eln (elastin). CS extract (CSE) also triggered IL17A expression in HBE cells. Blocking IL17A or IL17RA (IL17 receptor A) effectively attenuated CSE-induced MUC5AC and the inflammatory cytokines IL6, TNF-α, and IL1ß in HBE cells, suggesting that IL17A mediates CSE-induced inflammation and mucin production in an autocrine manner. CSE activated p-JUN (phospho-JUN) and p-JNK (phospho-c-Jun N-terminal kinase), which were also reduced by IL17RA siRNA, and JUN siRNA attenuated CSE-induced IL6 and MUC5AC. In vivo, selective knockout of IL17A in the airway epithelium markedly reduced the neutrophilic infiltration in BAL fluid, peribronchial inflammation, proinflammatory mediators (CXCL1 [CXC ligand 1] and CXCL2), and mucus production in a COPD mouse model. We showed a novel function of airway epithelium-derived IL17A, which can act locally in an autocrine manner to amplify inflammation and increase mucus production in COPD pathogenesis.


Assuntos
Fumar Cigarros/imunologia , Interleucina-17/imunologia , Muco/imunologia , Doença Pulmonar Obstrutiva Crônica/imunologia , Mucosa Respiratória/imunologia , Animais , Linhagem Celular , Fumar Cigarros/genética , Modelos Animais de Doenças , Humanos , Inflamação/genética , Inflamação/imunologia , Interleucina-17/genética , Camundongos , Camundongos Knockout , Infiltração de Neutrófilos/genética , Neutrófilos/imunologia , Doença Pulmonar Obstrutiva Crônica/genética
17.
Br J Haematol ; 192(5): 869-878, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33216361

RESUMO

Daratumumab is a CD38-targeting monoclonal antibody approved for intravenous (IV) infusion for multiple myeloma (MM). We describe the Phase II PLEIADES study of a subcutaneous formulation of daratumumab (DARA SC) in combination with standard-of-care regimens: DARA SC plus bortezomib/lenalidomide/dexamethasone (D-VRd) for transplant-eligible newly diagnosed MM (NDMM); DARA SC plus bortezomib/melphalan/prednisone (D-VMP) for transplant-ineligible NDMM; and DARA SC plus lenalidomide/dexamethasone (D-Rd) for relapsed/refractory MM. In total, 199 patients were treated (D-VRd, n = 67; D-VMP, n = 67; D-Rd, n = 65). The primary endpoints were met for all cohorts: the ≥very good partial response (VGPR) rate after four 21-day induction cycles for D-VRd was 71·6% [90% confidence interval (CI) 61·2-80·6%], and the overall response rates (ORRs) for D-VMP and D-Rd were 88·1% (90% CI 79·5-93·9%) and 90·8% (90% CI 82·6-95·9%). With longer median follow-up for D-VMP and D-Rd (14·3 and 14·7 months respectively), responses deepened (ORR: 89·6%, 93·8%; ≥VGPR: 77·6%, 78·5%), and minimal residual disease-negativity (10-5 ) rates were 16·4% and 15·4%. Infusion-related reactions across all cohorts were infrequent (≤9·0%) and mild. The median DARA SC administration time was 5 min. DARA SC with standard-of-care regimens demonstrated comparable clinical activity to DARA IV-containing regimens, with low infusion-related reaction rates and reduced administration time.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Imunoterapia , Mieloma Múltiplo/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/efeitos adversos , Antineoplásicos Imunológicos/administração & dosagem , Antineoplásicos Imunológicos/efeitos adversos , Bortezomib/administração & dosagem , Terapia Combinada , Dexametasona/administração & dosagem , Feminino , Seguimentos , Doenças Hematológicas/induzido quimicamente , Humanos , Lenalidomida/administração & dosagem , Masculino , Melfalan/administração & dosagem , Pessoa de Meia-Idade , Prednisona/administração & dosagem , Padrão de Cuidado , Resultado do Tratamento
18.
Bioorg Chem ; 85: 364-372, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30658236

RESUMO

Catechin and epicatechin are flavan-3-ols, with (+)-catechin (C) and (-)-epicatechin (EC) being the most common optical isomers found in nature. In this study, we found that C and EC showed notable inhibitory activity against a-glucosidase (AGH), and that both inhibition activities reversible and competitive. Additionally, we observed that C and EC quenched the intrinsic fluorescence of AGH through a static quenching mechanism, and that the electrostatic force was the predominant driving factor in the binding reaction. Molecular docking studies indicated that the benzene-ring-4'-hydroxyphenyl construct on flavan-3-ol plays an important role in AGH inhibition, and that the inhibition increases along with increased binding of amino acid residues at this site. Furthermore, C and EC inhibited glucose absorption in everted intestine sleeves in vitro and suppressed increases in postprandial blood glucose levels in vivo. Our results suggest that C and EC are useful to protect against hyperglycemia through inhibiting the activity of a-glucosidase.


Assuntos
Catequina/farmacologia , Inibidores de Glicosídeo Hidrolases/farmacologia , Hipoglicemiantes/farmacologia , alfa-Glucosidases/metabolismo , Animais , Domínio Catalítico , Catequina/metabolismo , Inibidores de Glicosídeo Hidrolases/metabolismo , Hipoglicemiantes/metabolismo , Mucosa Intestinal/metabolismo , Masculino , Simulação de Acoplamento Molecular , Ligação Proteica , Ratos Sprague-Dawley , Saccharomyces cerevisiae/enzimologia , alfa-Glucosidases/química
19.
Artigo em Inglês | MEDLINE | ID: mdl-29712658

RESUMO

Chemotherapeutic options against Mycobacterium abscessus infections are very limited. Bedaquiline, a new antituberculosis (anti-TB) drug, is effective for the treatment of multidrug-resistant TB. However, few data are available on bedaquiline for treatment of M. abscessus infections. In this study, we determined the profile for in vitro susceptibility of M. abscessus clinical isolates to bedaquiline and investigated the potential molecular mechanisms of decreased susceptibility. A total of 197 M. abscessus clinical isolates were collected from sputum and bronchoalveolar fluid of patients with lung infections. Standard broth microdilution test revealed that bedaquiline exhibited high in vitro killing activity against M. abscessus isolates, with a MIC50 of 0.062 and a MIC90 of 0.125 mg/liter. Whole-genome sequencing data showed that no nonsynonymous mutation occurred in atpE, the gene encoding the bedaquiline-targeted protein. However, of 6 strains with decreased susceptibility of bedaquiline (MIC = 0.5 to 1 mg/liter), 3 strains had nonsynonymous mutations in mab_4384, the gene encoding the repressor of efflux pump MmpS5/MmpL5. Quantitative reverse transcription-PCR (qRT-PCR) analysis showed that the expression of MmpS5/MmpL5 in the group with decreased susceptibility to bedaquiline was significantly higher than in those with medium MICs (MIC = 0.125 to 0.5 mg/liter) or in the low-MIC group (MIC ≤ 0.062 mg/liter). Two isolates with increased MICs did not show overexpression of MmpS5/MmpL5, which could not be explained by known molecular mechanisms. This is the first report showing the association of MmpS5/MmpL5 with decreased bedaquiline susceptibility in M. abscessus clinical isolates and suggesting the presence of other, yet-to-be identified mechanisms for decreased bedaquiline susceptibility in M. abscessus.


Assuntos
Antituberculosos/farmacologia , Diarilquinolinas/farmacologia , Farmacorresistência Bacteriana/genética , Mycobacterium abscessus/efeitos dos fármacos , Mycobacterium abscessus/isolamento & purificação , ATPases Bacterianas Próton-Translocadoras/genética , Genoma Bacteriano/genética , Humanos , Testes de Sensibilidade Microbiana , Infecções por Mycobacterium não Tuberculosas/tratamento farmacológico , Mycobacterium abscessus/genética , Sequenciamento Completo do Genoma
20.
Artigo em Inglês | MEDLINE | ID: mdl-29483126

RESUMO

Mycobacterium abscessus accounts for a large proportion of lung disease cases caused by rapidly growing mycobacteria. The association between clarithromycin sensitivity and treatment outcome is clear. However, M. abscessus culture and antibiotic susceptibility testing are time-consuming. Clarithromycin susceptibility genotyping offers an alternate, rapid approach to predicting the efficacy of clarithromycin-based antibiotic therapy. M. abscessus lung disease patients were divided into two groups based upon the clarithromycin susceptibility genotype of the organism isolated. A retrospective analysis was conducted to compare the clinical features, microbiological characteristics, and treatment outcomes of the two groups. Several other potential predictors of the response to treatment were also assessed. Sixty-nine patients were enrolled in the clarithromycin-resistant genotype group, which included 5 infected with rrl 2058-2059 mutants and 64 infected with erm(41)T28-type M. abscessus; 31 were in the clarithromycin-sensitive group, i.e., 6 and 25 patients infected with genotypes erm(41)C28 and erm(41) M type, respectively. The results showed that lung disease patients infected with clarithromycin-sensitive and -resistant M. abscessus genotypes differed significantly in clarithromycin-based combination treatment outcomes. Patients infected with the clarithromycin-sensitive genotype exhibited higher initial and final sputum-negative conversion and radiological improvement rates and better therapeutic outcomes. Multivariate analysis demonstrated that genotyping was a reliable and, more importantly, rapid means of predicting the efficacy of clarithromycin-based antibiotic treatment for M. abscessus lung disease.


Assuntos
Antibacterianos/farmacologia , Claritromicina/farmacologia , Mycobacterium abscessus/efeitos dos fármacos , Mycobacterium abscessus/genética , Genótipo , Humanos , Testes de Sensibilidade Microbiana , Estudos Retrospectivos
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