Avaliação da expressão dos componentes colinérgicos, citocinas e estresse oxidativo no pulmão e no sistema nervoso central em camundongos com lesão pulmonar aguda induzida por LPS intratraqueal
Data
2023-05-19
Autores
Castro, Stephanie Nonato de 
Orientadores
Prado, Carla Máximo
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
A síndrome do desconforto respiratório agudo é caracterizada por uma lesão pulmonar
aguda, na qual há o recrutamento de células do sistema imune, liberação de citocinas
inflamatórias e de espécies reativas de oxigênio. Este processo inflamatório pode afetar o
sistema nervoso central com repercussões cognitivas. Nossa hipótese é que a lesão
pulmonar aguda de origem pulmonar possa induzir alterações funcionais no sistema nervoso
central. Objetivo: Avaliar se a lesão pulmonar induzida por lipopolissacarídeo via
intratraqueal induz alterações cognitivas e dos componentes colinérgicos, citocinas e
estresse oxidativo no cérebro em modelo de camundongo. Material e Métodos:
Camundongos machos BALB/C receberam instilação intratraqueal de salina (Controle) ou
lipopolissacarídeo (LPS, 5mg/Kg) e foram avaliados após 24 ou 48 horas. Foi realizado teste
de tarefa de reconhecimento de objeto novo, que avalia memória de curto prazo, e, após a
eutanásia, pulmão e estruturas cerebrais foram coletadas para análise de estresse oxidativo
e de citocinas e componentes do sistema colinérgico por ELISA e/ou RT-PCR. Foi
considerado p<0,05 como significativo. Resultados: O lipopolissacarídeo induziu perda de
massa corpórea, edema pulmonar com presença de neutrófilos, macrófagos e linfócitos no
lavado broncoalveolar e neutrófilos no tecido, além do aumento da área alveolar com
distensão e colapso. Associado a estas alterações, houve aumento nos níveis de IL-1β, de
IL-6, CXCL1/KC, TNF-α no lavado broncoalveolar e da expressão gênica de IL-6, NF-kB e
do receptor mAChR M3 no pulmão. No teste de comportamento, os animais que receberam
lipopolissacarídeo permaneceram um mesmo percentual de tempo explorando o objeto novo
e o familiar, diferentemente do observado no grupo controle. Não houve aumento de
citocinas e do estresse oxidativo no cérebro, exceto a atividade da SOD que foi reduzida e
da catalase aumentada no hipocampo. Houve redução da expressão gênica do subtipos α4
no hipocampo e córtex pré- frontal, α7 no hipocampo e de acetilcolinesterase no córtex pré frontal. Houve correlação entre o tempo de exploração do objetivo novo e as alterações
pulmonares e de sistema nervoso central. Conclusão: A inflamação pulmonar,
caracterizada por aumento de edema pulmonar, de áreas colapsadas e distendidas, de
células inflamatórias e citocinas no pulmão induziu um prejuízo na memória de curto prazo e
a redução de receptores nicotinicos no sistema nervoso central. Estes dados sugerem que a
inflamação periférica é um estímulo para deterioração das funções cognitivas, associado à
redução de componentes colinérgicos no cérebro.
Acute respiratory distress syndrome is characterized by acute lung injury, in which immune cells are recruited, inflammatory cytokines are released, and reactive oxygen species are generated. This inflammatory process can affect the central nervous system with cognitive repercussions. Our hypothesis is that acute lung injury of pulmonary origin may induce functional changes in the central nervous system. Objective: To evaluate whether intratracheal lipopolysaccharide-induced lung injury affect cognitive impairment, cholinergic components, cytokine, and oxidative stress in the brain using a mouse model. Materials and Methods: Male BALB/C mice received intratracheal instillation of saline (Control) or lipopolysaccharide (LPS, 5mg/kg) and were evaluated at 24 or 48 hours. A novel object recognition task, which assesses short-term memory, was performed, and after euthanasia, lung and brain structures were collected for analysis of oxidative stress and cytokines and cholinergic components by ELISA and/or RT-PCR. A p<0.05 was considered significant. Results: Lipopolysaccharide induced weight loss, lung edema with the presence of neutrophils, macrophages, and lymphocytes in the bronchoalveolar lavage and neutrophils in the tissue, as well as increased alveolar area with distension and collapse. Associated with these alterations, there was an increase in IL-1β, IL-6, KC, TNF-α levels in the bronchoalveolar lavage and gene expression of IL-6, NF-kB, and the M3 mAChR receptor in the lung. In the behavioral test, animals receiving lipopolysaccharide remained exploring the novel and the familiar object for the same percentage of time, different from what was observed in the control group. There was no increase in cytokines and oxidative stress in the brain, except for decreased SOD activity and increased catalase activity in the hippocampus. There was a reduction in gene expression of the subtypes α4 in hippocampus and prefrontal cortex, α7 in the hippocampus, and acetylcholinesterase in the prefrontal cortex. There was a correlation between the exploration time of the novel object and lung and central nervous system alterations. Conclusion: Pulmonary inflammation, characterized by increased lung edema, collapsed and distended areas, inflammatory cells, and cytokines in the lung, induced impairment of short-term memory and reduction of nicotinic receptors in the brain. These data suggest that peripheral inflammation is a stimulus for deterioration of cognitive functions, associated with a reduction in cholinergic components in the brain.
Acute respiratory distress syndrome is characterized by acute lung injury, in which immune cells are recruited, inflammatory cytokines are released, and reactive oxygen species are generated. This inflammatory process can affect the central nervous system with cognitive repercussions. Our hypothesis is that acute lung injury of pulmonary origin may induce functional changes in the central nervous system. Objective: To evaluate whether intratracheal lipopolysaccharide-induced lung injury affect cognitive impairment, cholinergic components, cytokine, and oxidative stress in the brain using a mouse model. Materials and Methods: Male BALB/C mice received intratracheal instillation of saline (Control) or lipopolysaccharide (LPS, 5mg/kg) and were evaluated at 24 or 48 hours. A novel object recognition task, which assesses short-term memory, was performed, and after euthanasia, lung and brain structures were collected for analysis of oxidative stress and cytokines and cholinergic components by ELISA and/or RT-PCR. A p<0.05 was considered significant. Results: Lipopolysaccharide induced weight loss, lung edema with the presence of neutrophils, macrophages, and lymphocytes in the bronchoalveolar lavage and neutrophils in the tissue, as well as increased alveolar area with distension and collapse. Associated with these alterations, there was an increase in IL-1β, IL-6, KC, TNF-α levels in the bronchoalveolar lavage and gene expression of IL-6, NF-kB, and the M3 mAChR receptor in the lung. In the behavioral test, animals receiving lipopolysaccharide remained exploring the novel and the familiar object for the same percentage of time, different from what was observed in the control group. There was no increase in cytokines and oxidative stress in the brain, except for decreased SOD activity and increased catalase activity in the hippocampus. There was a reduction in gene expression of the subtypes α4 in hippocampus and prefrontal cortex, α7 in the hippocampus, and acetylcholinesterase in the prefrontal cortex. There was a correlation between the exploration time of the novel object and lung and central nervous system alterations. Conclusion: Pulmonary inflammation, characterized by increased lung edema, collapsed and distended areas, inflammatory cells, and cytokines in the lung, induced impairment of short-term memory and reduction of nicotinic receptors in the brain. These data suggest that peripheral inflammation is a stimulus for deterioration of cognitive functions, associated with a reduction in cholinergic components in the brain.
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Citação
CASTRO, Stephanie Nonato de. Avaliação da expressão dos componentes colinérgicos, citocinas e estresse oxidativo no pulmão e no sistema nervoso central em camundongos com lesão pulmonar aguda induzida por LPS intratraqueal. 2023. 81 f. Dissertação (Mestrado Interdisciplinar em Ciências da Saúde) - Instituto de Saúde e Sociedade, Universidade Federal de São Paulo, Santos, 2023.