RESUMO
Several clinical trials observed that enzastaurin prolonged QT interval in cancer patients. However, the mechanism of enzastaurin-induced QT interval prolongation is unclear. Therefore, this study aimed to assess the effect and mechanism of enzastaurin on QT interval and cardiac function. The Langendorff and Ion-Optix MyoCam systems were used to assess the effects of enzastaurin on QT interval, cardiac systolic function and intracellular Ca2+ transient in guinea pig hearts and ventricular myocytes. The effects of enzastaurin on the rapid delayed rectifier (IKr), the slow delayed rectifier K+ current (IKs), transient outward potassium current (Ito), action potentials, Ryanodine Receptor 2 (RyR2) and the sarcoplasmic/endoplasmic reticulum Ca2+ ATPase 2a (SERCA2a) expression and activity in HEK 293 cell system and primary cardiomyocytes were investigated using whole-cell recording technique and western blotting. We found that enzastaurin significantly prolonged QT interval in guinea pig hearts and increased the action potential duration (APD) in guinea pig cardiomyocytes in a dose-dependent manner. Enzastaurin potently inhibited IKr by binding to the human Ether-à-go-go-Related gene (hERG) channel in both open and closed states, and hERG mutant channels, including S636A, S631A, and F656V attenuated the inhibitory effect of enzastaurin. Enzastaurin also moderately decreased IKs. Additionally, enzastaurin also induced negative chronotropic action. Moreover, enzastaurin impaired cardiac systolic function and reduced intracellular Ca2+ transient via inhibition of RyR2 phosphorylation. Taken together, we found that enzastaurin prolongs QT, reduces heart rate and impairs cardiac systolic function. Therefore, we recommend that electrocardiogram (ECG) and cardiac function should be continuously monitored when enzastaurin is administered to cancer patients.
Assuntos
Síndrome do QT Longo , Canal de Liberação de Cálcio do Receptor de Rianodina , Humanos , Animais , Cobaias , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Células HEK293 , Síndrome do QT Longo/induzido quimicamente , Síndrome do QT Longo/metabolismo , Miócitos Cardíacos , Potenciais de Ação , Canais de Potássio Éter-A-Go-GoRESUMO
Chemerin is a multifunctional adipokine that regulates adipogenesis, insulin signaling and blood pressure and has thus a central function in metabolism. Mounting evidence confirmed a function of chemerin in various cancers. In this study, we investigated the role of chemerin in rhabdomyosarcoma (RMS), an aggressive soft tissue cancer that affects mainly children and young adults. We found chemerin expression in 93.8% (90 of 96) of RMS cases, with a range of 86.7-96.7% for the four RMS subgroups. While chemerin is uniformly expressed in normal skeletal muscle, its expression in RMS is patchy with interspersed areas that are devoid of chemerin. This variable chemerin expression is reflected by RMS cell lines as two of them (Rh41 and Rd18) were found to secrete chemerin while the two other ones (JR1 and RD) were negative. Deletion of chemerin in Rh41 and Rd18 cells did not alter their growth rate or morphology. We investigated the potential influence of chemerin on immune surveillance by coculturing parental and chemerin-deficient RMS cells with resting- or lipopolysaccharide (LPS)-activated human peripheral monocytes. The absence of chemerin in the RMS cells led to increased expression levels of the coinhibitory molecules PD-L1 and PD-L2 while levels of the costimulatory molecule CD86 were not changed. Further, the absence of chemerin enhanced the secretion of cytokines (IL-1ß, IL-6, IL-10 and TNF) that have been shown to support RMS pathogenesis. These data indicate that the loss of chemerin expression by RMS cells repolarizes monocytes in the tumor microenvironment to supporting tumor progression.
Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/sangue , COVID-19/imunologia , Produtos do Gene env/sangue , Produtos do Gene env/imunologia , Proteínas da Gravidez/sangue , Proteínas da Gravidez/imunologia , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/imunologia , Aborto Espontâneo , Aminoácidos , Anticorpos Monoclonais/química , Reações Cruzadas , Feminino , Células HEK293 , Humanos , Segurança do Paciente , GravidezRESUMO
Gefitinib, a tyrosine kinase inhibitor, was the first targeted therapy for non-small cell lung cancer (NSCLC). Gefitinib could block human Ether-à-go-go-Related Gene (hERG) channel, an important target in drug-induced long QT syndrome. However, it is unclear whether gefitinib could induce QT interval prolongation. Here, whole-cell patch-clamp technique was used for evaluating the effect of gefitinib on rapidly-activating delayed rectifier K+ current (IKr), slowly-activating delayed rectifier K+ current (IKs), transient outward potassium current (Ito), inward rectifier K+ current (IK1) and on action potentials in guinea pig ventricular myocytes. The Langendorff heart perfusion technique was used to determine drug effect on the ECG. Gefitinib depressed IKr by binding to open and closed hERG channels in a concentration-dependent way (IC50: 1.91 µM). The inhibitory effect of gefitinib on wildtype hERG channels was reduced at the hERG mutants Y652A, S636A, F656V and S631A (IC50: 8.51, 13.97, 18.86, 32.99 µM), indicating that gefitinib is a pore inhibitor of hERG channels. In addition, gefitinib accelerated hERG channel inactivation and decreased channel steady-state inactivation. Gefitinib also decreased IKs with IC50 of 23.8 µM. Moreover, gefitinib increased action potential duration (APD) in guinea pig ventricular myocytes and the corrected QT interval (QTc) in isolated perfused guinea pig hearts in a concentration-dependent way (1-30 µM). These findings indicate that gefitinib could prolong QTc interval by potently blocking hERG channel, modulating kinetic properties of hERG channel. Partial block of KCNQ1/KCNE1 could also contribute to delayed repolarization and prolonged QT interval. Thus, caution should be taken when gefitinib is used for NSCLC treatment.
Assuntos
Gefitinibe/farmacologia , Síndrome do QT Longo/metabolismo , Bloqueadores dos Canais de Potássio/farmacologia , Potenciais de Ação/efeitos dos fármacos , Animais , Canal de Potássio ERG1/antagonistas & inibidores , Canal de Potássio ERG1/metabolismo , Eletrocardiografia/efeitos dos fármacos , Cobaias , Células HEK293 , Ventrículos do Coração/efeitos dos fármacos , Humanos , Síndrome do QT Longo/induzido quimicamente , Masculino , Contração Miocárdica/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Técnicas de Patch-ClampRESUMO
OBJECTIVE: To study the risk factors and infection characteristics of nosocomial infection in children with acute lymphoblastic leukemia (ALL) and analyze the relationship between different nutritional status and nosocomial infection, early treatment response. METHOD: The clinical data of 133 children with ALL treated with CCCG-ALL-2015 from June 2016 to June 2019 (chemotherapy stage, risk level, MRD), infection during hospitalization (course of infection, laboratory indicators, sites of infection, outcome) and nutritional status (sex, age, height/ length, weight) were enrolled. The Chi 2 test and Logistic regression analysis were used for statistical analysis. RESULTS: The rate of nosocomial infection was 19.9% in 133 children with ALL, in which 3 were infection-related death. Sex, immunophenotype and risk showed no significantly affect on the occurrence of nosocomial infection (Pï¼0.05), but neutrophil count, hemoglobin level, platelet count, chemotherapy stage, length of stay in hospital and nutritional status showed affect on the occurrence of nosocomial infection (Pï¼0.05). Logistic multivariate regression analysis showed that chemotherapy stage, length of hospital stay, neutrophils and nutritional status were the independent risk factors, in which the respiratory tract infection was the most common. Gram-positive bacteria, Gram-negative bacteria and fungi accounted for 44.1%, 52.9% and 2.9% respectively. The negative rate of MRD in day 19 and day 46 between different nutritional status groups showed statistically significant (Pï¼0.05). CONCLUSION: Neutrophil count, chemotherapy stage, length of stay in hospital and nutritional status are independent risk factors for nosocomial infection. Among of them, nutritional status negatively correlated with nosocomial infection, and the poorer nutritional status, the higher risk of nosocomial infection. Malnutrition, overweight and obesity can affect the early treatment response of ALL children. The level of nutrition at first diagnosis can be used as a bad factor to evaluate the early treatment response of ALL children.
Assuntos
Infecção Hospitalar , Leucemia-Linfoma Linfoblástico de Células Precursoras , Criança , Bactérias Gram-Negativas , Humanos , Estado Nutricional , Estudos RetrospectivosRESUMO
Four water-soluble hydrazone-based three-dimensional (3D) flexible organic frameworks FOF-1-4 have been synthesized from a semirigid tetracationic tetraaldehyde and four flexible dihydrazides. 1H NMR spectroscopy indicated the quantitative formation of FOF-1-4 in D2O, while dynamic light scattering experiments revealed that, depending on the concentration, these porous frameworks display hydrodynamic diameters ranging from 50 to 120 nm. The porosity of the frameworks is confirmed by ethanol vapor adsorption experiments of the solid samples as well as the high loading capacity for a 2.3 nm porphyrin guest in water. The new water-soluble frameworks exhibit low cytotoxicity and form inherent pores with diameters of 5.3 or 6.7 nm, allowing rapid inclusion of proteins such as bovine serum albumin and green and orange fluorescent proteins, and efficient delivery of the proteins into normal and cancer cells. Flow cytometric analysis reveals percentages of the delivered cells up to 99.8%.
Assuntos
Estruturas Metalorgânicas/química , Proteínas/química , Etanol/química , Hidrazonas/química , Ressonância Magnética Nuclear Biomolecular , Espalhamento de Radiação , Solubilidade , Espectrofotometria Infravermelho , Água/químicaRESUMO
Intracellular pathogens are subject to elimination by a cellular immune response, and were therefore under evolutionary pressure to develop mechanisms that allow them to inhibit especially this arm of immunity. CD137, a T cell costimulatory molecule, and its ligand, CD137 ligand (CD137L), which is expressed on antigen presenting cells (APC), are potent drivers of cellular cytotoxic immune responses. Here, we report that different viruses usurp a negative feedback mechanism for the CD137-CD137L system that weakens cellular immune responses. Latent membrane protein (LMP)-1 and Tax, oncogenes of Epstein-Barr virus (EBV), and human T-cell lymphotropic virus (HTLV)-1, respectively, induce the expression of CD137. CD137 is transferred by trogocytosis to CD137L-expressing APC, and the CD137-CD137L complex is internalized and degraded, resulting in a reduced CD137-mediated T cell costimulation and a weakened cellular immune response which may facilitate the escape of the virus from immune surveillance. These data identify the usurpation of a CD137-based negative feedback mechanism by intracellular pathogens that enables them to reduce T cell costimulation.
Assuntos
Ativação Linfocitária/imunologia , Linfócitos T/imunologia , Evasão Tumoral/imunologia , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/metabolismo , Infecções Tumorais por Vírus/imunologia , Ligante 4-1BB/imunologia , Ligante 4-1BB/metabolismo , Animais , Células Apresentadoras de Antígenos/imunologia , Cricetinae , Deltaretrovirus/imunologia , Deltaretrovirus/patogenicidade , Genes Virais , Herpesvirus Humano 4/imunologia , Herpesvirus Humano 4/patogenicidade , Humanos , Camundongos , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/imunologia , VirulênciaRESUMO
The aim of this study was to elucidate the effects of zedoary turmeric oil (ZTO) on P450 activities (CYP1A2, CYP2C9, CYP2C19, CYP2B6, CYP2D6 and CYP3A4) in rats with liver cirrhosis induced by thioacetamide (TAA). For the induction of liver cirrhosis, rats were given TAA in their drinking water at a concentration of 0.03% for consecutive 5 weeks and then 0.04% for the next consecutive 5 weeks throughout the establishment of cirrhosis. Then the cirrhotic rats were ip given saline, ZTO 100, 200 and 400 mg/kg, respectively, once daily for 2 weeks. When cirrhosis model was established at week 10, all rats of five groups were administered intragastrically with 15 mg/kg phenacetin, 0.6 mg/kg tolbutamide, 15 mg/kg omeprazole, 15 mg/kg bupropion, 15 mg/kg metoprolol, and 10 mg/kg midazolam. Blood samples were collected at a series of time-points and the concentrations of probe drugs in plasma were determined by HPLC-MS/MS. The degree of liver cirrhosis was assessed by HE staining. The serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) from the model group increased by approximately 4-fold, and a decreased level of albumin (Alb) was also observed, as compared to the control group (P < 0.05). However, ZTO was found to reverse those changes of serum levels observed in the model group, and the 200 mg/kg ZTO treatment group showed the most obvious reverse tendency with significantly decreased ALT, AST and increased Alb levels (P < 0.05). The results indicated that ZTO with the dose of 100 mg/kg could inhibit the activities of CYP450 isoforms CYP2C9 and CYP2D6 in vivo in cirrhotic rats induced by TAA, while ZTO with the dose of 400 mg/kg could induce the activity of CYP2C19 in vivo in cirrhotic rats induced by TAA. However, ZTO showed no influence on cirrhotic rat hepatic CYP1A2, CYP2B6 and CYP3A4 activity in vivo. This has certain guiding significance to clinical treatment.