RESUMO
BACKGROUND: We aimed to evaluate the pulmonary and cerebral effects of low-tidal volume ventilation in pressure-support (PSV) and pressure-controlled (PCV) modes at two PEEP levels in acute ischemic stroke (AIS). METHODS: In this randomized experimental study, AIS was induced by thermocoagulation in 30 healthy male Wistar rats. After 24 h, AIS animals were randomly assigned to PSV or PCV with VT = 6 mL/kg and PEEP = 2 cmH2O (PSV-PEEP2 and PCV-PEEP2) or PEEP = 5 cmH2O (PSV-PEEP5 and PCV-PEEP5) for 2 h. Lung mechanics, arterial blood gases, and echocardiography were evaluated before and after the experiment. Lungs and brain tissue were removed for histologic and molecular biology analysis. The primary endpoint was diffuse alveolar damage (DAD) score; secondary endpoints included brain histology and brain and lung molecular biology markers. RESULTS: In lungs, DAD was lower with PSV-PEEP5 than PCV-PEEP5 (p < 0.001); interleukin (IL)-1ß was lower with PSV-PEEP2 than PCV-PEEP2 (p = 0.016) and PSV-PEEP5 than PCV-PEEP5 (p = 0.046); zonula occludens-1 (ZO-1) was lower in PCV-PEEP5 than PCV-PEEP2 (p = 0.042). In brain, necrosis, hemorrhage, neuropil edema, and CD45 + microglia were lower in PSV than PCV animals at PEEP = 2 cmH2O (p = 0.036, p = 0.025, p = 0.018, p = 0.011, respectively) and PEEP = 5 cmH2O (p = 0.003, p = 0.003, p = 0.007, p = 0.003, respectively); IL-1ß was lower while ZO-1 was higher in PSV-PEEP2 than PCV-PEEP2 (p = 0.009, p = 0.007, respectively), suggesting blood-brain barrier integrity. Claudin-5 was higher in PSV-PEEP2 than PSV-PEEP5 (p = 0.036). CONCLUSION: In experimental AIS, PSV compared with PCV reduced lung and brain injury. Lung ZO-1 reduced in PCV with PEEP = 2 versus PEEP = 5 cmH2O, while brain claudin-5 increased in PSV with PEEP = 2 versus PEEP = 5 cmH2O.
RESUMO
Despite long-standing efforts to enhance care for chronic asthma, symptomatic treatments remain the only option to manage this highly prevalent and debilitating disease. We demonstrate that key pathology of allergic asthma can be almost completely resolved in a therapeutic manner by inhaled gene therapy. After the disease was fully and stably established, we treated mice intratracheally with a single dose of thymulin-expressing plasmids delivered via nanoparticles engineered to have a unique ability to penetrate the airway mucus barrier. Twenty days after the treatment, we found that all key pathologic features found in the asthmatic lung, including chronic inflammation, pulmonary fibrosis, and mechanical dysregulation, were normalized. We conducted tissue- and cell-based analyses to confirm that the therapeutic intervention was mediated comprehensively by anti-inflammatory and antifibrotic effects of the therapy. We believe that our findings open a new avenue for clinical development of therapeutically effective gene therapy for chronic asthma.
Assuntos
Asma , Nanopartículas , Animais , Asma/genética , Asma/terapia , Modelos Animais de Doenças , Terapia Genética , Pulmão/patologia , Camundongos , Camundongos Endogâmicos BALB C , Nanopartículas/uso terapêutico , Fator Tímico Circulante/genética , Fator Tímico Circulante/farmacologia , Fator Tímico Circulante/uso terapêuticoRESUMO
BACKGROUND/AIMS: Vectors derived from adeno-associated viruses (AAVs) are important gene delivery tools for treating pulmonary diseases. Phosphorylation of surface-exposed tyrosine residues from AAV2 capsid targets the viral particles for ubiquitination and proteasome-mediated degradation, and mutations of these tyrosine residues lead to highly efficient vector transduction in vitro and in vivo in different organs. We evaluated the pulmonary transduction efficiency of AAV8 vectors containing point mutations in surface-exposed capsid tyrosine residues. METHODS: Male C57BL/6 mice (20-25 g, n=24) were randomly assigned into three groups: control group animals received intratracheal (i.t.) instillation of saline (50 µl), wild-type AAV8 group, and capsid mutant Y733F AAV8 group, which received (i.t.) AAV8 vectors containing the DNA sequence of enhanced green fluorescence protein (eGFP). Four weeks after instillation, lung mechanics and morphometry, vector transduction (immunohistochemistry and mRNA expression of eGFP), and inflammatory cytokines and growth factor expression were analyzed. RESULTS: Tyrosine-mutant AAV8 vectors displayed significantly increased transduction efficiency in the lung compared with their wild-type counterparts. No significant differences were observed in lung mechanics and morphometry between experimental groups. There was no evidence of inflammatory response in any group. CONCLUSION: AAV8 vectors may be useful for new therapeutic strategies for the treatment of pulmonary diseases.
Assuntos
Capsídeo , Dependovirus/genética , Vetores Genéticos , Pulmão/fisiopatologia , Tirosina/genética , Animais , Sequência de Bases , Citocinas/genética , Primers do DNA , Proteínas de Fluorescência Verde/genética , Peptídeos e Proteínas de Sinalização Intercelular/genética , Pulmão/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mutagênese Sítio-Dirigida , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo RealRESUMO
Thymulin has been shown to present anti-inflammatory and anti-fibrotic properties in experimental lung diseases. We hypothesized that a biologically active thymulin analog gene, methionine serum thymus factor, delivered by highly compacted DNA nanoparticles may prevent lung inflammation and remodeling in a mouse model of allergic asthma. The DNA nanoparticles are composed of a single molecule of plasmid DNA compacted with block copolymers of poly-L-lysine and polyethylene glycol (CK30PEG), which have been found safe in a human phase I/II clinical trial. Thymulin plasmids were detected in the lungs of ovalbumin-challenged asthmatic mice up to 27days after administration of DNA nanoparticles carrying thymulin plasmids. A single dose of DNA nanoparticles carrying thymulin plasmids prevented lung inflammation, collagen deposition and smooth muscle hypertrophy in the lungs of a murine model of ovalbumin-challenged allergic asthma, leading to improved lung mechanics. In the present model of chronic allergic asthma, highly compacted DNA nanoparticles using thymulin analog gene modulated the inflammatory and remodeling processes improving lung mechanics.
Assuntos
Remodelação das Vias Aéreas , Asma/genética , Asma/terapia , DNA/uso terapêutico , Pulmão/patologia , Nanopartículas/uso terapêutico , Fator Tímico Circulante/genética , Remodelação das Vias Aéreas/genética , Remodelação das Vias Aéreas/imunologia , Animais , Asma/imunologia , Asma/patologia , DNA/química , DNA/genética , Terapia Genética , Pulmão/imunologia , Pulmão/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Nanopartículas/química , Plasmídeos/química , Plasmídeos/genética , Plasmídeos/uso terapêutico , Fator Tímico Circulante/análiseRESUMO
Nanotechnology is an emerging science with the potential to create new materials and strategies involving manipulation of matter at the nanometer scale (<100 nm). With size-dependent properties, nanoparticles have introduced a new paradigm in pharmacotherapy - the possibility of cell-targeted drug delivery with minimal systemic side effects and toxicity. The present review provides a summary of published findings, especially regarding to nanoparticle formulations for lung diseases. The available data have shown some benefits with nanoparticle-based therapy in the development of the disease and lung remodeling in respiratory diseases. However, there is a wide gap between the concepts of nanomedicine and the published experimental data and clinical reality. In addition, studies are still required to determine the potential of nanotherapy and the systemic toxicity of nanomaterials for future human use.
Assuntos
Sistemas de Liberação de Medicamentos/métodos , Pneumopatias/tratamento farmacológico , Nanopartículas/uso terapêutico , Asma/tratamento farmacológico , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Tuberculose Pulmonar/tratamento farmacológicoRESUMO
Homemade remedies with Ptychopetalum olacoides (PO) roots are used by Amazonian peoples for treating various age-related conditions. We previously reported that Ptychopetalum olacoides ethanol extract significantly improved step-down inhibitory avoidance long-term memory in adult and reversed memory deficits in aging mice. Adding to previous data, this study shows that a single i.p. administration of Ptychopetalum olacoides ethanol extract (POEE 50 and 100 mg/kg) improved step-down inhibitory avoidance short-term memory (STM) 3 h after training in adult (2.5 month) mice; comparable results were obtained with POEE given p.o. at 800 mg/kg. Moreover, memory improvement was also observed in aging (14 months) mice presenting memory deficit as compared to adult mice. Furthermore, POEE (100 mg/kg) improved non-aversive memory systems in adult mice in an object recognition paradigm. Consistently with its traditional use this study add to previously reported data and reinforces that POEE facilitates memory processes. Although the acetylcholinesterase inhibitory properties described for this extract may be of relevance for improving memory processes, the molecular mechanism(s) underlying the memory improvement here reported needs further scrutiny.
Assuntos
Memória de Curto Prazo/efeitos dos fármacos , Olacaceae/química , Envelhecimento/fisiologia , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Masculino , Camundongos , Extratos Vegetais/farmacologia , Raízes de Plantas/químicaRESUMO
Amazonian peoples use traditional remedies prepared with Ptychopetalum olacoides (PO) roots for treating various age-related conditions. This study shows that a single intraperitoneally (i.p.) administration of Ptychopetalum olacoides ethanol extract (POEE, 50 and 100mg/kg) improved memory retrieval in step-down inhibitory avoidance (P Assuntos
Envelhecimento/efeitos dos fármacos
, Transtornos da Memória/tratamento farmacológico
, Memória/efeitos dos fármacos
, Olacaceae
, Envelhecimento/fisiologia
, Animais
, Masculino
, Memória/fisiologia
, Camundongos
, Extratos Vegetais/isolamento & purificação
, Extratos Vegetais/farmacologia
, Extratos Vegetais/uso terapêutico
, Raízes de Plantas
, Tempo de Reação/efeitos dos fármacos
, Tempo de Reação/fisiologia
RESUMO
BACKGROUND: Psychosis frequently occurs in Alzheimer's disease (AD), being associated with more severe cognitive decline, but the underlying mechanisms are unknown. OBJECTIVE: To investigate the effect of centrally administered beta-amyloid peptide, a model for AD, in the locomotor response to amphetamine, caffeine and MK-801, which are psychoactive drugs related to neurochemical changes occurring in psychosis. METHODS: Mice were intracerebroventricularly injected with beta-amyloid (25-35), and after 1 week they were tested in the passive avoidance, spontaneous alternation and locomotor tasks. RESULTS: Besides impaired performance in inhibitory avoidance and spontaneous alternation tasks, beta-amyloid-treated mice showed increased spontaneous locomotion, augmented response to amphetamine (1.5 mg/kg), blunted response to caffeine (30 mg/kg) and no difference in MK-801 (0.25 mg/kg)-induced locomotor activation when compared to its respective control. CONCLUSION: These results are compatible with the hypothesis that beta-amyloid peptide may predispose to psychotic symptoms of AD by increasing sensitivity of the dopaminergic system, possibly related to a decreased adenosinergic inhibitory tone.
Assuntos
Adrenérgicos/farmacologia , Anfetamina/farmacologia , Peptídeos beta-Amiloides/administração & dosagem , Encéfalo/efeitos dos fármacos , Cafeína/farmacologia , Atividade Motora/efeitos dos fármacos , Adenosina/metabolismo , Doença de Alzheimer/complicações , Doença de Alzheimer/fisiopatologia , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Encéfalo/metabolismo , Estimulantes do Sistema Nervoso Central/farmacologia , Modelos Animais de Doenças , Maleato de Dizocilpina/farmacologia , Dopamina/metabolismo , Antagonistas de Aminoácidos Excitatórios/farmacologia , Glutamina/efeitos dos fármacos , Glutamina/metabolismo , Injeções Intraventriculares , Masculino , Camundongos , Transtornos Psicóticos/etiologia , Transtornos Psicóticos/fisiopatologiaRESUMO
RATIONALE: Administration of N-methyl- d-aspartate (NMDA) receptor antagonists produce hyperlocomotion and cognitive deficits in rodents. Activation of NMDA receptors promotes adenosine release, and adenosine agonists prevent central effects of NMDA receptor antagonists. We hypothesized that if NMDA receptor antagonists require adenosine to produce behavioral effects, mice tolerant to the adenosine receptor antagonist caffeine would have a diminished response to NMDA receptor antagonists. OBJECTIVES: To evaluate MK-801-induced hyperlocomotion and cognitive deficits after chronic caffeine treatment in mice. METHODS: Locomotor activity was analyzed in a computerized system, spontaneous alternation was assessed in the Y-maze and long-term memory was assessed with the inhibitory avoidance task in mice. RESULTS: Mice chronically treated with caffeine in drinking solution (1 mg/ml for 7 days) presented normal habituation and substantial tolerance to acute caffeine (30 mg/kg, i.p.) locomotor effects. MK-801 (0.25 mg/kg, i.p.) produced pronounced hyperlocomotion in water-treated mice, but this effect was abolished in caffeine-drinking mice. Chronic caffeine treatment had no influence on either normal or MK-801-induced deficits in spontaneous alternation and inhibitory avoidance tasks. CONCLUSION: Hyperlocomotion induced by MK-801 may be mediated by reduced adenosinergic activity. These results also suggest that locomotor and cognitive effects of MK-801 can be dissociated and are distinctly modulated. Finally, these findings agree with the adenosine hypofunction model of schizophrenia, since NMDA receptor antagonists are a pharmacological model for this disorder.