RESUMO
Agents targeting B-cell receptor (BCR) signaling-associated kinases such as Bruton tyrosine kinase (BTK) or phosphatidylinositol 3-kinase can induce mobilization of neoplastic B cells from the lymphoid tissues into the blood, which makes them potentially ideal to combine with anti-CD20 monoclonal antibodies (such as rituximab, obinutuzumab, or ofatumumab) for treatment of B-cell lymphomas and chronic lymphocytic leukemia (CLL). Here we show that interactions between leukemia cells and stromal cells (HS-5) upregulate CD20 on CLL cells and that administering ibrutinib downmodulates CD20 (MS4A1) expression in vivo. We observed that CLL cells that have recently exited the lymph node microenvironment and moved into the peripheral blood (CXCR4(dim)CD5(bright) subpopulation) have higher cell surface levels of CD20 than the cells circulating in the bloodstream for a longer time (CXCR4(bright)CD5(dim) cells). We found that CD20 is directly upregulated by CXCR4 ligand stromal cell-derived factor 1 (SDF-1α, CXCL12) produced by stromal cells, and BTK-inhibitor ibrutinib and CXCR4-inhibitor plerixafor block SDF-1α-mediated CD20 upregulation. Ibrutinib also downmodulated Mcl1 levels in CLL cells in vivo and in coculture with stromal cells. Overall, our study provides a first detailed mechanistic explanation of CD20 expression regulation in the context of chemokine signaling and microenvironmental interactions, which may have important implications for microenvironment-targeting therapies.
Assuntos
Antígenos CD20/química , Quimiocina CXCL12/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Pirazóis/farmacologia , Pirimidinas/farmacologia , Receptores CXCR4/metabolismo , Adenina/análogos & derivados , Antígenos CD20/genética , Antígenos CD20/metabolismo , Quimiocina CXCL12/genética , Humanos , Leucemia Linfocítica Crônica de Células B/metabolismo , Leucemia Linfocítica Crônica de Células B/patologia , Piperidinas , Receptores CXCR4/genética , Transdução de Sinais , Células Tumorais Cultivadas , Regulação para CimaRESUMO
OBJECTIVES: Apart from infections and habitat loss, environmental pollution is another major factor of global decline of amphibians. Using the model of Xenopus laevis embryos, we test the hypothesis that combined exposure of amphibians to natural toxins and anthropogenic pollutants induces more pronounced adverse effects than single exposures. METHODS: Experimental procedures adhered to Frog Embryo Teratogenesis Assay - Xenopus standards (FETAX). Exposure groups included controls, solvent (dimethyl sulfoxide) controls, and embryos exposed for 96 h to single, double and triple action of paraoxon (P), bromadiolone (B), and microcystin-LR (M), added to the FETAX medium at a dose of 300, 350, and 500 µg.L(-1), respectively. Studied responses of X. laevis embryos included mortality and malformations, head-to-tail length, total antioxidant capacity, lipid peroxidation, and caspase-3 activity. RESULTS: The triple combination induced the highest mortality. Malformations in embryos significantly prevailed only in B-, and B+P-exposure groups. Apart from the single exposure to B, the tested substances and their combinations inhibited the embryonic growth. Triple exposure had the most pronounced effect both on the growth inhibition and total antioxidant capacity. Lipid peroxidation was increased after B+M exposure, while single and combined exposures to B and P had an opposite effect. CONCLUSIONS: This study helps to understand adverse effects of environmental pollution by natural toxins and agrochemicals in amphibians. The results allow for risk assessment of environmental pollution and findings of low concentrations of contaminants in aquatic environments. Further research to address issues such as mixture toxicity to metamorphosing and adult amphibians is necessary.
Assuntos
4-Hidroxicumarinas/toxicidade , Anormalidades Induzidas por Medicamentos , Anticoagulantes/toxicidade , Inibidores da Colinesterase/toxicidade , Embrião não Mamífero/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Microcistinas/toxicidade , Paraoxon/toxicidade , Animais , Tamanho Corporal/efeitos dos fármacos , Caspase 3/efeitos dos fármacos , Embrião não Mamífero/embriologia , Inibidores Enzimáticos/toxicidade , Toxinas Marinhas , Testes de Toxicidade , Xenopus laevis/embriologiaRESUMO
BACKGROUND: Lead, a serious threat for raptors, can hamper the success of their conservation. This study reports on experience with accidental lead intoxication and responses to chelation therapy in captive Cinereous (Aegypius monachus) and Egyptian (Neophron percnopterus) Vultures. RESULTS: Soil contamination by lead-based paint sanded off the steel aviary resulted in poisoning of eight Cinereous and two Egyptian Vultures. A male Egyptian Vulture developed signs of apathy, polydipsia, polyuria, regurgitation, and stupor, and died on the next day. Liver, kidney and blood lead concentrations were 12.2, 8.16 and 2.66 µg/g, respectively. Laboratory analyses confirmed severe liver and kidney damage and anaemia. Blood Pb levels of Pb-exposed Cinereous Vultures were 1.571 ± 0.510 µg/g shortly after intoxication, decreased to 0.530 ± 0.165 µg/g without any therapy in a month and to 0.254 ± 0.097 µg/g one month after CaNa(2)EDTA administration. Eight months later, blood lead levels decreased to close to the background of the control group. Blood parameters of healthy Pb-non-exposed Cinereous Vultures were compared with those of the exposed group prior to and after chelation therapy. Iron levels in the lead-exposed pre-treatment birds significantly decreased after chelation. Haematocrit levels in Pb-exposed birds were significantly lower than those of the controls and improved one month after chelation. Creatine kinase was higher in pre-treatment birds than in the controls but normalised after therapy. Alkaline phosphatase increased after chelation. A marked increase in the level of lipid peroxidation measured as thiobarbituric acid reactive species was demonstrated in birds both prior to and after chelation. The ferric reducing antioxidant power was significantly lower in pre-treatment vultures and returned to normal following chelation therapy. Blood metallothionein levels in lead-exposed birds were higher than in controls. Reduced glutathione dropped after CaNa(2)EDTA therapy, while oxidised glutathione was significantly lower in both pre- and post-treatment birds. A chick in an egg produced by a Cinereous Vulture female two months after lead toxicosis died on day 40 of artificial incubation. Lead concentrations in foetal tissues were consistent with levels causing avian mortality. CONCLUSIONS: The reported blood parameters and reproduction impairment in captive birds may have implications for professionals dealing with lead exposure in wild birds.
Assuntos
Doenças das Aves/tratamento farmacológico , Terapia por Quelação/veterinária , Ácido Edético/uso terapêutico , Falconiformes , Intoxicação por Chumbo/veterinária , Animais , Animais de Zoológico , Doenças das Aves/induzido quimicamente , Terapia por Quelação/métodos , Falconiformes/sangue , Feminino , Chumbo/sangue , Intoxicação por Chumbo/tratamento farmacológico , MasculinoRESUMO
OBJECTIVES: Pharmaceuticals and heavy metals such as diclofenac and lead, respectively, have been identified as environmental contaminants toxic to birds and posing serious threats to declining populations of raptors worldwide. The aim of the present study was to test the hypothesis that a sublethal combination of non-steroidal anti-inflammatory drugs and lead induces more pronounced effects than single exposures in birds. METHODS: A total of 40 Japanese quails (Coturnix coturnix japonica) at the age of 2 months and average weight of 180g were on a random basis divided into four experimental groups of 10 specimens (i.e., control, diclofenac, lead, and lead+diclofenac exposures). Six lead shots in the total weight of 1.5 grams were inserted into the crop on day 0 of the experiment, while a total of 5 mg/kg of diclofenac administered intramuscularly were divided into treatments on days 0 and 5. Group responses were compared using haematology and biochemistry after 10 days. RESULTS: There was no mortality in control and both single and combined diclofenac and lead exposure groups, nor did the birds show any clinical signs of intoxication. Univariate analyses of blood parameters yielded a decrease in haematocrit in birds exposed to both substances when compared with the control, a lower haemoglobin level of the lead-exposed group, increased activity of aspartate aminotransferase in the NSAIDs-exposed group, increased activity of alkaline phosphatase in birds exposed to a combination of diclofenac and lead, and a higher phosphorus level in the lead-exposed group. The principal component analysis revealed no multivariate pattern of responses of blood parameters and did not allow separation of exposure groups from controls when the variables and samples were projected onto a two dimensional space. CONCLUSIONS: Results of the present study can enhance understanding of combination toxicity of veterinary drugs and heavy metals in birds, i.e. a scenario that has become environmentally relevant in recent decades. Fortunately, individual blood parameter effects prevailed and no joint mortal effects were recognised in Japanese quails exposed to a combination of sublethal doses of diclofenac and lead.
Assuntos
Anti-Inflamatórios não Esteroides/toxicidade , Coturnix , Diclofenaco/toxicidade , Poluentes Ambientais/toxicidade , Intoxicação por Chumbo/sangue , Chumbo/toxicidade , Animais , Proteínas Sanguíneas/metabolismo , Sinergismo Farmacológico , Trato Gastrointestinal/efeitos dos fármacos , Hemoglobinas/metabolismo , Intoxicação por Chumbo/mortalidade , Distribuição Aleatória , Fatores de Risco , Testes de ToxicidadeRESUMO
OBJECTIVES: The objective of this study was to examine the hypothesis that a combination of cyanobacterial biomass containing microcystins, acetylcholinesterase inhibitor and anticoagulant can enhance avian toxic effects produced by single exposures only. METHODS: A total of 48 two-month-old Japanese quails (Coturnix coturnix japonica) with average body weight of 160 g were randomly divided into 8 experimental groups of six birds and sex ratio of 1:1. Experimental groups of control Japanese quails (C) and birds exposed to single and combined sub-lethal doses of paraoxon (P), bromadiolone (B), and microcystins in cyanobacterial biomass (M) included: C, P, P+B, B, B+M, P+M, M, and P+B+M. During the 10-day exposure birds in the respective groups received biomass containing 61.62 µg microcystins daily (i.e. 26.54 µg MC-RR, 7.62 µg MC-YR and 27.39 µg MC-LR), two 250 µg/kg doses of paraoxon, and two 500 mg/kg doses of bromadiolone. Group responses were compared using standard plasma biochemistry and antioxidant/oxidative stress parameters in tissues. RESULTS: While single and double combinations of toxicants induced responses in individual biochemical parameters measured and evaluated using univariate statistical analysis, those in the triple exposure were most extensive. The principal component analysis of antioxidant/oxidative stress parameters (glutathione reductase, lipid peroxidation, and ferric reducing antioxidant power) in tissues (liver, kidney, heart, brain, lungs, gonads, and pectoralis major muscle) clearly separated the triple group (P+B+M) from all single and double exposure groups and the control and indicated thus marked joint effects in the overall pattern of antioxidant/oxidative stress responses of this group. The separation was driven by the modification of the ferric reducing antioxidant power levels in heart and brain and the cardiac lipid peroxidation level, in particular. CONCLUSIONS: This experiment contributes to the understanding of the pathogenic mechanisms of combined sub-lethal exposure to natural toxins and agrochemicals and may be used for risk assessment of environmental pollution in birds.
Assuntos
4-Hidroxicumarinas/toxicidade , Coturnix , Cianobactérias/química , Microcistinas/toxicidade , Paraoxon/toxicidade , Animais , Anticoagulantes/toxicidade , Biomassa , Encéfalo/efeitos dos fármacos , Carcinógenos/toxicidade , Inibidores da Colinesterase/toxicidade , Feminino , Coração/efeitos dos fármacos , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Masculino , Músculo Esquelético/efeitos dos fármacos , Distribuição Aleatória , Fatores de RiscoRESUMO
OBJECTIVES: Previous studies using oral administration of environmentally relevant doses of cyanobacterial biomass containing microcystins (MCs) induced only sub-lethal effects in experimental birds. Therefore, the objective of this study was to obtain data on avian high-dose toxicity of MCs and compute LD50, if possible, following the natural oral route of administration. DESIGN: Responses of birds to single high-dose exposure to MCs were evaluated in fourteen-day old Japanese quail males (Coturnix coturnix japonica) with average body weight of 50 g which were randomly divided into five groups. Birds from four experimental groups were administered 7.5 ml of cyanobacterial biomass suspension containing increasing MCs quantities of 2500, 5000, 10000, and 20000 µg/kg using oral gavage. Controls received an equal dose of drinking water instead of the test substance. Birds were observed for clinical signs of acute toxicity. Survivors were killed on day 5 to obtain body and liver weights. A five-grade semi-quantitative system for histopathological liver damage scoring was used to compare cyanobacterial-biomass-exposed birds against controls. RESULTS: No mortality occurred during the period of five days post exposure in both control and MCs-exposed groups and this high-dose experiment failed to provide data to compute the LD50. Nevertheless, marked sub-lethal effects were recognised in the damage of liver that included dose-dependent changes in the body/liver ratios and morphological changes ranging from mild vacuolar dystrophy to focal liver necroses in the highest exposure group. Hepatic lesions were mainly observed in the pericentral area of the liver. CONCLUSIONS: Though maximum cyanobacterial biomass dose rates that could be administered to birds of the size were used in the present experiment and more pronounced hepatic lesions than after exposure to environmentally relevant doses were observed, birds would probably have survived unless killed for histopathology on day 5 of exposure. These results provide support to previously reported data on sub-lethal effects following exposure to cyanobacterial biomass containing MCs in birds and mortality occurring only in birds under combined action with other stressors.
Assuntos
Toxinas Bacterianas/toxicidade , Coturnix , Cianobactérias/química , Toxinas Marinhas/toxicidade , Microcistinas/toxicidade , Animais , Biomassa , Peso Corporal , Carcinógenos/toxicidade , Doença Hepática Induzida por Substâncias e Drogas/epidemiologia , Doença Hepática Induzida por Substâncias e Drogas/patologia , Toxinas de Cianobactérias , Relação Dose-Resposta a Droga , Hepatócitos/efeitos dos fármacos , Hepatócitos/patologia , Dose Letal Mediana , Masculino , Tamanho do Órgão , Distribuição Aleatória , Fatores de RiscoRESUMO
BACKGROUND: The grey partridge is an important game bird in Europe that has declined considerably over the last decades. The production and release of farm-bred birds can be threatened by infectious agents. The objective of this study was to describe the outbreak, pathology, and blood and tissue biochemical responses in a flock of grey partridges naturally infected with Mycoplasma gallisepticum. RESULTS: Morbidity and mortality rates were 100% and 60%, respectively. Necropsy revealed an accumulation of caseous exudate within the infraorbital sinuses, tracheitis, pneumonia and airsacculitis. There were significant increases in activities of lactate dehydrogenase, creatine kinase and amylase, and levels of total protein and glucose in Mycoplasma-infected birds when compared to control. Catalase showed significantly lower activity in the heart, lungs, liver and gonads of Mycoplasma-infected birds. Glutathione-S-transferase activity was elevated in the eye and the associated infraorbital sinus and kidneys, and decreased in the liver. Decreased levels of reduced glutathione were found in the heart, kidneys, liver and gonads. The activity of glutathione reductase was lower only in the lungs. Compared to healthy birds, mycoplasmosis in the grey partridge caused significant differences in the level of lipid peroxidation in lungs and plasma (p < 0.05), while the ferric reducing antioxidant power was lower in the heart and kidneys (p < 0.01). Significant correlations among responses of the antioxidant parameters were found namely in the heart, lungs, spleen, liver and plasma. There were also numerous significant inter-tissue correlations of all the studied antioxidant parameters. CONCLUSIONS: The present study demonstrates the high susceptibility of grey partridges to natural infection by M. gallisepticum, the severity of the disease based on histopathology, and the modulation of blood chemical profiles and oxidative stress-associated parameters in the avian hosts, thus enhancing the understanding of the pathogenesis of mycoplasmosis in birds. Moreover, the reported reference values can be useful for the evaluation of the state of health in grey partridges.
Assuntos
Doenças das Aves/microbiologia , Galliformes/microbiologia , Infecções por Mycoplasma/virologia , Mycoplasma gallisepticum , Animais , Antioxidantes/análise , Doenças das Aves/epidemiologia , Doenças das Aves/metabolismo , Doenças das Aves/patologia , República Tcheca/epidemiologia , Surtos de Doenças/veterinária , Feminino , Galliformes/sangue , Masculino , Infecções por Mycoplasma/epidemiologia , Infecções por Mycoplasma/microbiologia , Infecções por Mycoplasma/patologia , Reação em Cadeia da Polimerase/veterinária , Sistema Respiratório/patologiaRESUMO
OBJECTIVES: The causative agent of tularemia Francisella tularensis is highly infectious and lagomorphs are important reservoirs and a source of human disease. The aim of the present study was to test the hypothesis that sublethal exposure to pesticides increases the susceptibility of hares to F. tularensis and modulates the course of the infection. METHODS: Experimental hares were allocated to a) control, b) paraoxon-treated, c) F. tularensis-treated, and d) paraoxon-and-F. tularensis-treated groups of five specimens on a random basis and subcutaneously inoculated with a wild F. tularensis subsp. holarctica strain (a single dose of 9 × 108 CFU pro toto) and/or injected a sublethal dose of paraoxon (100 µg/kg). Group differences were evaluated using survival curves, oxidative stress responses as well as caspase-3 and acetylcholinesterase activities in whole blood samples collected on day 2 post exposure. RESULTS: The paraoxon-and-F. tularensis-treated group showed a rapid onset of clinical signs and all deaths occurred on days 2 and 3 post exposure. F. tularensis-inoculated hares survived from 3 to 10 days, while only one hare died on day 12 in the paraoxon-treated group. Survival curves in the three exposed groups were significantly different from the control and median survival in F. tularensis-inoculated and paraoxon-and-F. tularensis-treated hares amounted to 7 and 2 days, respectively. Compared with controls, significant responses included an eight- and seven-fold activation of caspase-3 in F. tularensis-inoculated and paraoxon-and-F. tularensis-treated hares, respectively, and a 1.5-fold decrease of blood acetylcholinesterase activities in the paraoxon-treated and paraoxon-and-F. tularensis-treated groups. There was a 1.3- to 1.4-fold decrease of the ferric reducing antioxidant power in blood of F. tularensis-inoculated hares and the paraoxon-and-F. tularensis-treated group, respectively. The blood lipid peroxidation levels were of no differences among the four experimental groups. CONCLUSIONS: Results of this study can help understand the pathogenesis of tularemia and mortality of hares in agricultural habitats. Use of anticholinesterase agents in agriculture can pose a threat of infectious disease outbreaks and higher mortality in wildlife populations.