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Chromothripsis is a catastrophic cellular event recently described in cancer in which chromosomes undergo massive deletion and rearrangement. Here, we report a case in which chromothripsis spontaneously cured a patient with WHIM syndrome, an autosomal dominant combined immunodeficiency disease caused by gain-of-function mutation of the chemokine receptor CXCR4. In this patient, deletion of the disease allele, CXCR4(R334X), as well as 163 other genes from one copy of chromosome 2 occurred in a hematopoietic stem cell (HSC) that repopulated the myeloid but not the lymphoid lineage. In competitive mouse bone marrow (BM) transplantation experiments, Cxcr4 haploinsufficiency was sufficient to confer a strong long-term engraftment advantage of donor BM over BM from either wild-type or WHIM syndrome model mice, suggesting a potential mechanism for the patient's cure. Our findings suggest that partial inactivation of CXCR4 may have general utility as a strategy to promote HSC engraftment in transplantation.
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Instabilidade Cromossômica , Síndromes de Imunodeficiência/genética , Verrugas/genética , Animais , Cromossomos Humanos , Modelos Animais de Doenças , Haploinsuficiência , Células-Tronco Hematopoéticas/metabolismo , Humanos , Linfócitos/metabolismo , Masculino , Camundongos , Pessoa de Meia-Idade , Mosaicismo , Mutação , Células Mieloides/metabolismo , Doenças da Imunodeficiência Primária , Receptores CXCR4/genética , Remissão EspontâneaRESUMO
WHIM syndrome is an autosomal dominant immunodeficiency disorder caused by gain-of-function mutations in chemokine receptor CXCR4 that promote severe panleukopenia because of retention of mature leukocytes in the bone marrow (BM). We previously reported that Cxcr4-haploinsufficient (Cxcr4+/o) hematopoietic stem cells (HSCs) have a strong selective advantage for durable hematopoietic reconstitution over wild-type (Cxcr4+/+) and WHIM (Cxcr4+/w) HSCs and that a patient with WHIM was spontaneously cured by chromothriptic deletion of the disease allele in an HSC, suggesting that WHIM allele inactivation through gene editing may be a safe genetic cure strategy for the disease. We have developed a 2-step preclinical protocol of autologous hematopoietic stem and progenitor cell (HSPC) transplantation to achieve this goal. First, 1 copy of Cxcr4 in HSPCs was inactivated in vitro by CRISPR/Cas9 editing with a single guide RNA (sgRNA) that does not discriminate between Cxcr4+/w and Cxcr4+/+ alleles. Then, through in vivo natural selection, WHIM allele-inactivated cells were enriched over wild-type allele-inactivated cells. The WHIM allele-inactivated HSCs retained long-term pluripotency and selective hematopoietic reconstitution advantages. To our knowledge, this is the first example of gene therapy for an autosomal dominant gain-of-function disease using a disease allele inactivation strategy in place of the less efficient disease allele repair approach.
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Síndromes de Imunodeficiência , Verrugas , Camundongos , Animais , Alelos , Sistemas CRISPR-Cas , RNA Guia de Sistemas CRISPR-Cas , Síndromes de Imunodeficiência/genética , Síndromes de Imunodeficiência/terapia , Verrugas/genética , Verrugas/terapia , Terapia Genética , Receptores CXCR4/genéticaRESUMO
Warts, hypogammaglobulinemia, infections, and myelokathexis (WHIM) syndrome is an ultra-rare combined primary immunodeficiency disease caused by heterozygous gain-of-function mutations in the chemokine receptor CXCR4. WHIM patients typically present with recurrent acute infections associated with myelokathexis (severe neutropenia due to bone marrow retention of mature neutrophils). Severe lymphopenia is also common, but the only associated chronic opportunistic pathogen is human papillomavirus and mechanisms are not clearly defined. In this study, we show that WHIM mutations cause more severe CD8 than CD4 lymphopenia in WHIM patients and WHIM model mice. Mechanistic studies in mice revealed selective and WHIM allele dose-dependent accumulation of mature CD8 single-positive cells in thymus in a cell-intrinsic manner due to prolonged intrathymic residence, associated with increased CD8 single-positive thymocyte chemotactic responses in vitro toward the CXCR4 ligand CXCL12. In addition, mature WHIM CD8+ T cells preferentially home to and are retained in the bone marrow in mice in a cell-intrinsic manner. Administration of the specific CXCR4 antagonist AMD3100 (plerixafor) in mice rapidly and transiently corrected T cell lymphopenia and the CD4/CD8 ratio. After lymphocytic choriomeningitis virus infection, we found no difference in memory CD8+ T cell differentiation or viral load between wild-type and WHIM model mice. Thus, lymphopenia in WHIM syndrome may involve severe CXCR4-dependent CD8+ T cell deficiency resulting in part from sequestration in the primary lymphoid organs, thymus, and bone marrow.
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Agamaglobulinemia , Compostos Heterocíclicos , Síndromes de Imunodeficiência , Linfopenia , Neutropenia , Humanos , Animais , Camundongos , Síndromes de Imunodeficiência/genética , Mobilização de Células-Tronco Hematopoéticas/efeitos adversos , Agamaglobulinemia/complicações , Agamaglobulinemia/genética , Neutropenia/genética , Linfócitos T CD8-Positivos , Receptores CXCR4/genéticaRESUMO
Foodborne illnesses, particularly those caused by Salmonella enterica with its extensive array of over 2600 serovars, present a significant public health challenge. Therefore, prompt and precise identification of S. enterica serovars is essential for clinical relevance, which facilitates the understanding of S. enterica transmission routes and the determination of outbreak sources. Classical serotyping methods via molecular subtyping and genomic markers currently suffer from various limitations, such as labour intensiveness, time consumption, etc. Therefore, there is a pressing need to develop new diagnostic techniques. Surface-enhanced Raman spectroscopy (SERS) is a non-invasive diagnostic technique that can generate Raman spectra, based on which rapid and accurate discrimination of bacterial pathogens could be achieved. To generate SERS spectra, a Raman spectrometer is needed to detect and collect signals, which are divided into two types: the expensive benchtop spectrometer and the inexpensive handheld spectrometer. In this study, we compared the performance of two Raman spectrometers to discriminate four closely associated S. enterica serovars, that is, S. enterica subsp. enterica serovar dublin, enteritidis, typhi and typhimurium. Six machine learning algorithms were applied to analyse these SERS spectra. The support vector machine (SVM) model showed the highest accuracy for both handheld (99.97%) and benchtop (99.38%) Raman spectrometers. This study demonstrated that handheld Raman spectrometers achieved similar prediction accuracy as benchtop spectrometers when combined with machine learning models, providing an effective solution for rapid, accurate and cost-effective identification of closely associated S. enterica serovars.
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Salmonella enterica , Sorogrupo , Análise Espectral Raman , Máquina de Vetores de Suporte , Análise Espectral Raman/métodos , Salmonella enterica/isolamento & purificação , Humanos , AlgoritmosRESUMO
INTRODUCTION: Fragmentation of care (FC, the receipt of care at > 1 institution) has been shown to negatively impact cancer outcomes. Given the multimodal nature of breast cancer treatment, we sought to identify factors associated with FC and its effects on survival of breast cancer patients. METHODS: A retrospective analysis was performed of surgically treated, stage I-III breast cancer patients in the 2004-2020 National Cancer Database, excluding neoadjuvant therapy recipients. Patients were stratified into two groups: FC or non-FC care. Treatment delay was defined as definitive surgery > 60 days after diagnosis. Multivariable logistic regression was performed to identify factors predictive of FC, and survival was compared using Kaplan-Meier and multivariable Cox proportional hazards methods. RESULTS: Of the 531,644 patients identified, 340,297 (64.0%) received FC. After adjustment, FC (OR 1.27, 95% CI 1.25-1.29) was independently associated with treatment delay. Factors predictive of FC included Hispanic ethnicity (OR 1.04, 95% CI: 1.01-1.07), treatment at comprehensive community cancer programs (OR 1.06, 95% CI: 1.03-1.08) and integrated network cancer programs (OR 1.55, 95% CI: 1.51-1.59), AJCC stage II (OR 1.06, 95% CI 1.05-1.07) and stage III tumors (OR 1.06, 95% CI: 1.02-1.10), and HR + /HER2 + tumors (OR 1.05, 95% CI: 1.02-1.07). Treatment delay was independently associated with increased risk of mortality (HR 1.23, 95% CI 1.20-1.26), whereas FC (HR 0.87, 95% CI 0.86-0.88) showed survival benefit. CONCLUSIONS: While treatment delay negatively impacts survival in breast cancer patients, our findings suggest FC could be a marker for multispecialty care that may mitigate some of these effects.
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AIM: WHIM (warts, hypogammaglobulinaemia, infections and myelokathexis) syndrome is a rare combined primary immunodeficiency disease caused by gain-of-function (GOF) mutations in the chemokine receptor CXCR4 and includes severe neutropenia as a common feature. Neutropenia is a known risk factor for periodontitis; however, a detailed periodontal evaluation of a WHIM syndrome cohort is lacking. This study aimed to establish the evidence base for the periodontal status of patients with WHIM syndrome. MATERIALS AND METHODS: Twenty-two adult WHIM syndrome patients and 22 age- and gender-matched healthy volunteers (HVs) were evaluated through a comprehensive medical and periodontal examination. A mouse model of WHIM syndrome was assessed for susceptibility to naturally progressing or inducible periodontitis. RESULTS: Fourteen patients with WHIM syndrome (63.6%) and one HV (4.5%) were diagnosed with Stage III/IV periodontitis. No WHIM patient presented with the early onset, dramatic clinical phenotypes typically associated with genetic forms of neutropenia. Age, but not the specific CXCR4 mutation or absolute neutrophil count, was associated with periodontitis severity in the WHIM cohort. Mice with a Cxcr4 GOF mutation did not exhibit increased alveolar bone loss in spontaneous or ligature-induced periodontitis. CONCLUSIONS: Overall, WHIM syndrome patients presented with an increased severity of periodontitis despite past and ongoing neutrophil mobilization treatments. GOF mutations in CXCR4 may be a risk factor for periodontitis in humans.
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Síndromes de Imunodeficiência , Neutropenia , Doenças Periodontais , Periodontite , Doenças da Imunodeficiência Primária , Verrugas , Adulto , Humanos , Animais , Camundongos , Síndromes de Imunodeficiência/complicações , Síndromes de Imunodeficiência/genética , Síndromes de Imunodeficiência/diagnóstico , Doenças da Imunodeficiência Primária/complicações , Doenças da Imunodeficiência Primária/genética , Verrugas/genética , Verrugas/terapia , Neutropenia/complicações , Neutropenia/genética , Doenças Periodontais/complicações , Doenças Periodontais/genética , Periodontite/complicações , Periodontite/genéticaRESUMO
Triphenyltin (TPT) is a typical persistent organic pollutant whose occurrence in coral reef ecosystems may threaten the survival of reef fishes. In this study, a brightly colored representative reef fish, Amphiprion ocellaris was used to explore the effects of TPT at environmental levels (1, 10, and 100â¯ng/L) on skin pigment synthesis. After the fish were exposed to TPT for 60 days, the skin became darker, owing to an increase in the relative area of black stripes, a decrease in orange color values while an increase in brown color values, and an increase in the number of melanocytes in the orange part of the skin tissues. To explore the mechanisms by which TPT induces darker body coloration, the enzymatic activity and gene expression levels of the members of melanocortin system that affect melanin synthesis were evaluated. Leptin levels and lepr expression were found to be increased after TPT exposure, which likely contributed to the increase found in pomc expression and α-melanocyte-stimulating hormone (α-MSH) levels. Then Tyr activity and mc1r, tyr, tyrp1, mitf, and dct were upregulated, ultimately increasing melanin levels. Importantly, RT-qPCR results were consistent with the transcriptome analysis of trends in lepr and pomc expression. Because the orange color values decreased, pterin levels and the pteridine metabolic pathway were also evaluated. The results showed that TPT induced BH4 levels and spr, xdh, and gch1 expression associated with pteridine synthesis decreased, ultimately decreasing the colored pterin content (sepiapterin). We conclude that TPT exposure interferes with the melanocortin system and pteridine metabolic pathway to increase melanin and decrease colored pterin levels, leading to darker body coloration in A. ocellaris. Given the importance of body coloration for the survival and reproduction of reef fishes, studies on the effects of pollutants (others alongside TPT) on body coloration are of high priority.
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Melanocortinas , Compostos Orgânicos de Estanho , Perciformes , Animais , Pró-Opiomelanocortina , Ecossistema , Melaninas/genética , Pteridinas , Peixes/genética , Perciformes/genética , Pterinas , Redes e Vias MetabólicasRESUMO
The selective oxidation of benzylic C-H bonds is a pivotal transformation in organic synthesis. Undoubtedly, achieving efficient and highly selective aerobic oxidation of methylarenes to benzaldehydes has been highly challenging due to the propensity of benzaldehyde to undergo overoxidation under typical aerobic conditions. Herein, we propose an innovative approach to address this issue by leveraging electrocatalytic processes, facilitated by ion-pair mediators [Ph3C]+[B(C6F5)4]-. By harnessing the power of electrochemistry, we successfully demonstrated the effectiveness of our strategy, which enables the selective oxidation of benzylic C-H bonds in benzylic molecules and toluene derivatives. Notably, our approach exhibited high efficiency, excellent selectivity, and compatibility with various functional groups, underscoring the broad applicability of our methodology.
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KEY MESSAGE: A total of 282 mungbean accessions were resequenced to identify genome-wide variants and construct a highly precise variant map, and drought tolerance-related loci and superior alleles were identified by GWAS. Mungbean (Vigna radiata (L.) R. Wilczek) is an important food legume crop that is highly adapted to drought environments, but severe drought significantly curtails mungbean production. Here, we resequenced 282 mungbean accessions to identify genome-wide variants and constructed a highly precise map of mungbean variants. A genome-wide association study was performed to identify genomic regions for 14 drought tolerance-related traits in plants grown under stress and well-watered conditions over three years. One hundred forty-six SNPs associated with drought tolerance were detected, and 26 candidate loci associated with more than two traits were subsequently selected. Two hundred fifteen candidate genes were identified at these loci, including eleven transcription factor genes, seven protein kinase genes and other protein coding genes that may respond to drought stress. Furthermore, we identified superior alleles that were associated with drought tolerance and positively selected during the breeding process. These results provide valuable genomic resources for molecular breeding and will accelerate future efforts aimed at mungbean improvement.
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Fabaceae , Vigna , Vigna/genética , Resistência à Seca , Estudo de Associação Genômica Ampla , Melhoramento Vegetal , Fabaceae/genética , GenômicaRESUMO
Ribonucleases (RNases) play critical roles in RNA metabolism and are collectively essential for cell viability. However, most knowledge about bacterial RNases comes from the studies on Escherichia coli; very little is known about the RNases in plant pathogens. The crucifer black rot pathogen Xanthomonas campestris pv. campestris (Xcc) encodes 15 RNases, but none of them has been functionally characterized. Here, we report the physiological function of the exoribonuclease RNase D in Xcc and provide evidence demonstrating that the Xcc RNase D is involved in 5S rRNA degradation and exopolysaccharide (EPS) production. Our work shows that the growth and virulence of Xcc were not affected by deletion of RNase D but were severely attenuated by RNase D overexpression. However, deletion of RNase D in Xcc resulted in a significant reduction in EPS production. In addition, either deletion or overexpression of RNase D in Xcc did not influence the tRNAs tested, inconsistent with the finding in E. coli that the primary function of RNase D is to participate in tRNA maturation and its overexpression degrades tRNAs. More importantly, deletion, overexpression, and in vitro enzymatic analyses revealed that the Xcc RNase D degrades 5S rRNA but not 16S and 23S rRNAs that share an operon with 5S rRNA. Our results suggest that Xcc employs RNase D to realize specific modulation of the cellular 5S rRNA content after transcription and maturation whenever necessary. The finding expands our knowledge about the function of RNase D in bacteria.
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Xanthomonas campestris , Xanthomonas campestris/metabolismo , RNA Ribossômico 5S/metabolismo , Ribonuclease III/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Doenças das Plantas/microbiologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismoRESUMO
The zinc uptake regulator (Zur) is a member of the Fur (ferric uptake regulator) family transcriptional regulators that plays important roles in zinc homeostasis and virulence of bacteria. Upon zinc perception, Zur binds to the promoters of zinc responsive genes and controls their transcription. However, the mechanism underlying zinc-mediated Zur activation remains unclear. Here we report a 2.2-Å crystal structure of apo Zur from the phytopathogen Xanthomonas campestris pv. campestris (XcZur), which reveals the molecular mechanism that XcZur exists in a closed inactive state before regulatory zinc binding. Subsequently, we present a 1.9-Å crystal structure of holo XcZur, which, by contrast, adopts an open state that has enough capacity to bind DNA. Structural comparison and hydrogen deuterium exchange mass spectrometry (HDX-MS) analyses uncover that binding of a zinc atom in the regulatory site, formed by the hinge region, the dimerization domain and the DNA binding domain, drives a closed-to-open conformational change that is essential for XcZur activation. Moreover, key residues responsible for DNA recognition are identified by site-directed mutagenesis. This work provides important insights into zinc-induced XcZur activation and valuable discussions on the mechanism of DNA recognition.
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Proteínas de Bactérias/química , Zinco/química , Proteínas de Bactérias/metabolismo , Cristalografia por Raios X , DNA/química , DNA/metabolismo , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Alinhamento de Sequência , Transcrição Gênica , Xanthomonas campestrisRESUMO
China's emission control for nonroad diesel mobile machinery (NDMM) must deal with a fast increase in stock as well as regulations that are two decades behind those for on-road vehicles. This study provides the first large-scale review and evaluation of China's NDMM policies, along with emission measurements and an investigation on diesel fuel quality. The sulfur contents of the investigated diesel declined from 430 ppm (median value) in 2011 to 6-8 ppm during the 2017-2018 period. The emission control of NOx and PM greatly improved with the shift from the China II to China IV standards, as demonstrated by engine tests and field NOx measurements. However, the NOx emission factors for non-type-approved engines were approximately twice the limits of the China II standards. Emission compliance based on bench tests was not sufficient to control actual emissions because the field-measured NOx emission factors of all machinery ranged from 24% to 225% greater than the respective emission limits for the engines. These circumstances adversely affected the effectiveness of the regulations and policies for China's emission control of NDMM. Nevertheless, the policies on new and in-use NDMM, as well as diesel fuel quality, prevented NOx and PM emissions amounting to 4.4 Tg and 297.8 Gg during the period 2008-2017, respectively. The emission management strategy contributed to enhancing the international competitiveness of China's NDMM industries by promoting advanced technologies. For effective NDMM emission control in the future, portable testing and noncontact remote supervision should be strengthened; also, the issue of noncompliant diesel should be addressed through rigorous control measures and financial penalties.
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Poluentes Atmosféricos , Emissões de Veículos , Poluentes Atmosféricos/análise , China , Gasolina , Enxofre , Emissões de Veículos/análiseRESUMO
The C-X-C chemokine receptor CXCR4 and its ligand CXCL12 play an important role in organ-specific vascular branching morphogenesis. CXCR4 is preferentially expressed by arterial endothelial cells, and local secretion of CXCL12 determines the organotypic pattern of CXCR4+ arterial branching. Previous loss-of-function studies clearly demonstrated that CXCL12-CXCR4 signaling is necessary for proper arterial branching in the developing organs such as the skin and heart. To further understand the role of CXCL12-CXCR4 signaling in organ-specific vascular development, we generated a mouse model carrying the Cre recombinase-inducible Cxcr4 transgene. Endothelial cell-specific Cxcr4 gain-of-function embryos exhibited defective vascular remodeling and formation of a hierarchical vascular branching network in the developing skin and heart. Ectopic expression of CXCR4 in venous endothelial cells, but not in lymphatic endothelial cells, caused blood-filled, enlarged lymphatic vascular phenotypes, accompanied by edema. These data suggest that CXCR4 expression is tightly regulated in endothelial cells for appropriate vascular development in an organ-specific manner.
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Vasos Sanguíneos/embriologia , Células Endoteliais/fisiologia , Neovascularização Fisiológica/fisiologia , Receptores CXCR4/fisiologia , Animais , Vasos Sanguíneos/anatomia & histologia , Células Endoteliais/metabolismo , Mutação com Ganho de Função , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Receptores CXCR4/biossíntese , Remodelação Vascular/fisiologiaRESUMO
A tri-mode micro-square laser under optical feedback is proposed and demonstrated to generate chaos with the broadband flat microwave spectrum. By adjusting lasing mode intensities, frequency intervals, and optical feedback strength, we can enhance the chaotic bandwidth significantly. The existence of two mode-beating peaks makes the flat bandwidth much larger than the relaxation oscillation frequency. Effective bandwidth of 35.3 GHz is experimentally achieved with the flatness of 8.3 dB from the chaotic output spectrum of the tri-mode mode laser under optical feedback.
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Clear cell renal cell carcinoma (ccRCC) is a highly angiogenic cancer. Manic fringe (MFng) is elevated in ccRCC compared to the normal kidney. However, its role in ccRCC tumour angiogenesis remains elusive. This study seeks to determine the expression pattern of MFng in ccRCC blood vessels and its role in angiogenesis. The association between MFng and the blood vessels was established through online compendia, immunohistochemistry and qPCR analyses. The anti-angiogenic potential of lentiviral-mediated MFng knockdown in endothelial cells (EC shMFng) was assessed for viability, proliferation, apoptosis, migration, adhesion, cell cycle, vessel sprouting, and molecular expression of adhesion and apoptosis markers. Finally, EC shMFng were co-cultured with 786-0 renal cancer cells to determine their impact on cancer cell migration. The online dataset analyses and immunostaining on ccRCC tissues revealed high expression of MFng in ECs. MFng and CD31/PECAM-1 genes were up-regulated in ccRCC tissue samples compared to normal kidney tissues. EC shMFng demonstrated decreased cell viability due to G1 cell cycle arrest and reduced Ki-67 protein expression. In addition, shMFng down-regulated endothelial adhesion molecules and hindered EC migration, network formation and sprouting, compared to their respective empty vector (EV) controls. Co-culture assay of EC shMFng with 786-0 renal cancer cells inhibited cancer cell migration. These findings underscore the potential role of MFng in ECs in influencing renal cancer cell migration, thus opening an avenue for anti-angiogenic strategy targeting MFng to treat ccRCC.
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Carcinoma de Células Renais , Neoplasias Renais , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/metabolismo , Carcinoma de Células Renais/patologia , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Regulação para Baixo , Células Endoteliais/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Renais/genética , Neoplasias Renais/metabolismo , Neoplasias Renais/patologiaRESUMO
Cataracts are a common consequence of aging; however, pathogenesis remains poorly understood. Here, we observed that after 3 months of age mice lacking the G protein-coupled leukocyte chemotactic receptor Fpr1 (N-formyl peptide receptor 1) began to develop bilateral posterior subcapsular cataracts that progressed to lens rupture and severe degeneration, without evidence of either systemic or local ocular infection or inflammation. Consistent with this, Fpr1 was detected in both mouse and human lens in primary lens epithelial cells (LECs), the only cell type present in the lens; however, expression was confined to subcapsular LECs located along the anterior hemispheric surface. To maximize translucency, LECs at the equator proliferate and migrate posteriorly, then differentiate into lens fiber cells by nonclassical apoptotic signaling, which results in loss of nuclei and other organelles, including mitochondria which are a rich source of endogenous N-formyl peptides. In this regard, denucleation and posterior migration of LECs were abnormal in lenses from Fpr1-/- mice, and direct stimulation of LECs with the prototypic N-formyl peptide agonist fMLF promoted apoptosis. Thus, Fpr1 is repurposed beyond its immunoregulatory role in leukocytes to protect against cataract formation and lens degeneration during aging.
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Envelhecimento/metabolismo , Envelhecimento/patologia , Catarata/metabolismo , Receptores de Formil Peptídeo/metabolismo , Animais , Catarata/patologia , Diferenciação Celular/fisiologia , Proliferação de Células/genética , Proliferação de Células/fisiologia , Citometria de Fluxo , Proteínas de Ligação ao GTP/genética , Proteínas de Ligação ao GTP/metabolismo , Humanos , Imuno-Histoquímica , Imageamento por Ressonância Magnética , Camundongos , Camundongos Endogâmicos C57BL , Receptores de Formil Peptídeo/genética , UltrassonografiaRESUMO
The Mukaiyama-aldol reaction is probably one of the most efficient strategies to prepare synthetically useful ß-hydroxy carbonyl compounds. However, only several reported methods were concerned with the accesses to α-fluoro-ß-hydroxy esters. Herein, we report a protocol for a fluoride anion-mediated Mukaiyama aldol reaction with low catalytic loading in a short reaction time to incorporate fluorine at the α position into ß-hydroxy esters. The method shows good functional-group tolerance and scale-up potential, moreover, is applicable to the late-stage modification of natural products and small molecular drugs.
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Ésteres , Fluoretos , Aldeídos , Ânions , Catálise , Estrutura MolecularRESUMO
Formyl peptide receptors (FPRs, mouse Fprs) belong to the G protein-coupled receptor superfamily and mediate phagocyte migration in response to bacteria- and host-derived chemoattractants; however, knowledge about their in vivo roles in bacterial pathogenesis is limited. In this study, we investigated the role of Fpr1 and Fpr2 in host defense against Escherichia coli infection. In vitro, we found that supernatants from E. coli cultures induced chemotaxis of wild-type (WT) mouse bone marrow-derived neutrophils and that the activity was significantly reduced in cells genetically deficient in either Fpr1 or Fpr2 and was almost absent in cells lacking both receptors. Consistent with this, E. coli supernatants induced chemotaxis and MAPK phosphorylation in HEK293 cells expressing either recombinant Fpr1 or Fpr2 but not untransfected parental cells. WT bone marrow -derived neutrophils could actively phagocytose and kill E. coli, whereas both activities were diminished in cells lacking Fpr1 or Fpr2; again, an additive effect was observed in cells lacking both receptors. In vivo, Fpr1 and Fpr2 deficiency resulted in reduced recruitment of neutrophils in the liver and peritoneal cavity of mice infected with inactivated E. coli Moreover, Fpr1-/- and Fpr2-/- mice had significantly increased mortality compared with WT mice after i.p. challenge with a virulent E. coli clinical isolate. These results indicate a critical role of Fprs in host defense against E. coli infection.
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Infecções por Escherichia coli/imunologia , Infecções por Escherichia coli/metabolismo , Escherichia coli/imunologia , Receptores de Formil Peptídeo/imunologia , Receptores de Formil Peptídeo/metabolismo , Animais , Medula Óssea/imunologia , Medula Óssea/metabolismo , Medula Óssea/microbiologia , Células Cultivadas , Quimiotaxia/imunologia , Células HEK293 , Humanos , Fígado/imunologia , Fígado/metabolismo , Fígado/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Quinases Ativadas por Mitógeno/imunologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Neutrófilos/imunologia , Neutrófilos/metabolismo , Neutrófilos/microbiologia , Cavidade Peritoneal/microbiologia , Fagocitose/imunologia , Fosforilação/imunologiaRESUMO
Cardiac hypertrophy is a common adaptive response to a variety of stimuli, but prolonged hypertrophy leads to heart failure. Hence, discovery of agents treating cardiac hypertrophy is urgently needed. In the present study, we investigated the effects of QF84139, a newly synthesized pyrazine derivative, on cardiac hypertrophy and the underlying mechanisms. In neonatal rat cardiomyocytes (NRCMs), pretreatment with QF84139 (1-10 µM) concentration-dependently inhibited phenylephrine-induced hypertrophic responses characterized by fetal genes reactivation, increased ANP protein level and enlarged cardiomyocytes. In adult male mice, administration of QF84139 (5-90 mg·kg-1·d-1, i.p., for 2 weeks) dose-dependently reversed transverse aortic constriction (TAC)-induced cardiac hypertrophy displayed by cardiomyocyte size, left ventricular mass, heart weights, and reactivation of fetal genes. We further revealed that QF84139 selectively activated the AMPK signaling pathway without affecting the phosphorylation of CaMKIIδ, ERK1/2, AKT, PKCε, and P38 kinases in phenylephrine-treated NRCMs and in the hearts of TAC-treated mice. In NRCMs, QF84139 did not show additive effects with metformin on the AMPK activation, whereas the anti-hypertrophic effect of QF84139 was abolished by an AMPK inhibitor Compound C or knockdown of AMPKα2. In AMPKα2-deficient mice, the anti-hypertrophic effect of QF84139 was also vanished. These results demonstrate that QF84139 attenuates the PE- and TAC-induced cardiac hypertrophy via activating the AMPK signaling. This structurally novel compound would be a promising lead compound for developing effective agents for the treatment of cardiac hypertrophy.
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Proteínas Quinases Ativadas por AMP/efeitos dos fármacos , Cardiomegalia/patologia , Miócitos Cardíacos/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Aorta/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Tamanho do Órgão/efeitos dos fármacos , Fenilefrina/farmacologia , RNA Interferente Pequeno/farmacologia , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacosRESUMO
OBJECTIVE: Alcohol consumption is always the main cause of acute pancreatitis (AP). It has been reported that alcohol exerts direct damage to the pancreas. However, the specific role of alcohol during AP needs to be investigated. This study aims to examine the effects of alcohol in cerulein-induced AP and the role of the AMPK pathway. METHODS: Human subjects from operations, cerulein-induced AP rat, and cerulein-stimulated AR42J cell line were enrolled in this study. Electron microscopy was employed for observation of cell morphology, immunohistochemistry for identification of cells, ELISA for detection of inflammation factors, Annexin V/PI double staining for evaluation of cell apoptosis, immunofluorescence for assessment of autophagic flux, oil red O staining for examination of lipid droplet accumulation, and Western blot for measurement of expressions of proteins related to autophagy, apoptosis, and AMPK signal pathway. PI3K inhibitor 3-MA and AMPK inhibitor BML-275 were utilized for investigation of the relationship between impaired autophagic flux and the AMPK pathway by inhibiting or stimulating the formation of autophagosome. RESULTS: Alcohol consumption caused lipid droplet accumulation in the pancreas, and it also activated AMPK signaling pathway, thus aggravating the autophagic flux during AP. Alcohol up-regulated the expressions of anti-apoptotic proteins during the induction of AP to inhibit cell apoptosis and enhance cell necrosis. Inhibition of autophagosome formation by AMPK inhibitor BML-275 ameliorated the decreased cell viability caused by alcohol and cerulein in vitro. CONCLUSION: Alcohol aggravates AP progression by impairing autophagic flux and enhancing cell autophagy through the AMPK signaling pathway.