RESUMO
Abstract EphrinB2 plays a critical role in tumor growth. In this study, we studied the antitumor activity of imperatorin derivative IMP-1 in renal cell carcinoma (RCC) by regulating EphrinB2 pathway.. Results showed that IMP-1 inhibited the proliferation of 786-O cells in a dose- and time-dependent manner. More importantly, knockdown and transfection of EphrinB2 altered the inhibitory effect of IMP-1 on the activity of 786-O cells. IMP-1 arrested 786-O cell cycle at G0/G1 phase by decreasing the expression of cyclin D1 and cyclin E. Moreover, IMP-1 regulated Bcl-2 family proteins' expression, thus inducing apoptosis of 786-O cells. IMP-1 down-regulated the expression of EphrinB2, Syntenin1 and PICK1. Then, IMP-1 decreased the phosphorylation of Erk1/2 and AKT. In all, IMP-1 could regulate the EphrinB2 pathway in order to inhibit 786-O cell growth by arresting the cell cycle at G0/G1 phase and inducing cell apoptosis. Thus, IMP-1 may present as a potential strategy for RCC treatment.
Assuntos
Carcinoma de Células Renais/patologia , Neoplasias/classificação , Fase G1/genética , Ciclina D1/efeitos adversos , Ciclina E/efeitos adversosRESUMO
Outer membrane vesicles (OMVs) act as carriers of bacterial products such as plasmids and resistance determinants, including metallo-ß-lactamases. The lipidated, membrane-anchored metallo-ß-lactamase NDM-1 can be detected in Gram-negative OMVs. The soluble domain of NDM-1 also forms electrostatic interactions with the membrane. Here, we show that these interactions promote its packaging into OMVs produced by Escherichia coli. We report that favorable electrostatic protein-membrane interactions are also at work in the soluble enzyme IMP-1 while being absent in VIM-2. These interactions correlate with an enhanced incorporation of IMP-1 compared to VIM-2 into OMVs. Disruption of these interactions in NDM-1 and IMP-1 impairs their inclusion into vesicles, confirming their role in defining the protein cargo in OMVs. These results also indicate that packaging of metallo-ß-lactamases into vesicles in their active form is a common phenomenon that involves cargo selection based on specific molecular interactions.
Assuntos
Escherichia coli , beta-Lactamases , Escherichia coli/genética , Plasmídeos/genética , beta-Lactamases/genéticaRESUMO
Acinetobacter baumannii is the main species of the Acinetobacter genus; however, non-baumannii Acinetobacter (NBA) species causing infections have been described for the past years, as well as antimicrobial resistance. In this study, we describe the occurrence of two multidrug-resistant (MDR) IMP-1-producing Acinetobacter bereziniae isolates recovered from bloodstream infections in different patients but in the same intensive care unit among 134 carbapenem-resistant Acinetobacter screened. Antimicrobial susceptibility testing revealed resistance to carbapenems, extended spectrum, and antipseudomonad cephalosporins, amikacin, and trimethoprim-sulfamethoxazole. Both A. bereziniae isolates shared the same ApaI-pulsed-field gel electrophoresis (PFGE) pattern. Whole-genome sequencing of both isolates revealed that blaIMP-1 was embedded into an In86 Class I integron carrying also sul1, aac(6')-31, and aadA genes. A new sequence type (ST1309 Pasteur) was deposited. The virulence genes lpxC and ompA, seen in A. baumannii, were detected in the A. bereziniae strains. Recognition of A. bereziniae causing invasive MDR infection underscores the role of NBA species as human pathogens especially in at-risk patients.
Assuntos
Acinetobacter/genética , Acinetobacter/isolamento & purificação , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Farmacorresistência Bacteriana Múltipla/genética , Sepse/microbiologia , beta-Lactamases/genética , Acinetobacter/efeitos dos fármacos , Infecções por Acinetobacter/tratamento farmacológico , Infecções por Acinetobacter/microbiologia , Antibacterianos/farmacologia , Brasil , Carbapenêmicos/farmacologia , Infecção Hospitalar/tratamento farmacológico , Infecção Hospitalar/microbiologia , Genômica/métodos , Humanos , Integrons/genética , Testes de Sensibilidade Microbiana/métodos , Sepse/tratamento farmacológico , Centros de Atenção TerciáriaRESUMO
Acinetobacter spp. are opportunistic pathogens being A. baumannii the most frequently identified in nosocomial settings. A. ursingii was mainly described as causing bacteremia and outbreaks in neonatal intensive care units. Ten A. ursingii isolates were recovered from rectal swab screening for carbapenemase-producing bacteria between June 2013 and December 2015 from a children hospital in Argentina. All ten isolates were metallo-ß-lactamase-producing, nine were positive for blaIMP-1 and one for blaNDM-1. IMP-positive isolates were also positive for blaOXA-58 gene. All isolates were susceptible to ciprofloxacin, colistin and minocycline, and nine were susceptible to ampicillin-sulbactam and gentamicin. Two A. ursingii displayed high level of resistance to aztreonam associated with blaCTX-M-15 in one isolate, and blaVEB-1 in the other. Eight SmaI-PFGE patterns were recognized. We evaluated the usefulness of Acinetobacter MLST-Pasteur scheme, to analyse A. ursingii isolates, however the rpoB gene was not amplified. A new set of primers were designed for specific amplification and sequencing, allowing the analysis of rpoB gene for this species. New alleles and the sequence types 748, 749, 750, 751, 993, 1186, 1187, and 1189 were included at the Acinetobacter MLST-Pasteur database. Those isolates showing related PFGE patterns were assigned to the same ST. To the best of our knowledge, this is the first report of MBL-producing A. ursingii in Argentina. The inclusion of A. ursingii species to the Acinetobacter MLST-Pasteur scheme allows deeper molecular characterization and a better understanding about the epidemiology of this germen.
Assuntos
Infecções por Acinetobacter/epidemiologia , Infecções por Acinetobacter/microbiologia , Acinetobacter/genética , Infecção Hospitalar , beta-Lactamases/genética , Acinetobacter/classificação , Acinetobacter/efeitos dos fármacos , Infecções por Acinetobacter/tratamento farmacológico , Antibacterianos/farmacologia , Argentina/epidemiologia , Criança , Eletroforese em Gel de Campo Pulsado , Hospitais Pediátricos , Humanos , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Filogenia , Resistência beta-LactâmicaRESUMO
This study aimed to characterize multidrug-resistant Proteus mirabilis clones carrying a novel class 1 integron-borne blaIMP-1 In1359 was inserted into a large conjugative plasmid that also carried blaCTX-M-2 The production of carbapenemases in Enterobacteriaceae that are intrinsically resistant to polymyxins and tigecycline is very worrisome, representing a serious challenge to clinicians and infection control teams.