Tnf-a production and apoptosis in hepatocytes after listeria monocytogenes and salmonella typhimurium invasion / Produção de tnf-a e apoptose em hepatócitos após invasão por listeria monocytogenes e salmonella typhimurium
Rev. Inst. Med. Trop. Säo Paulo
;
53(2): 107-112, Mar.-Apr. 2011. ilus, graf, tab
Article
in English
| LILACS
| ID: lil-584142
ABSTRACT
Invasion of hepatocytes by Listeria monocytogenes (LM) and Salmonella Typhimurium (ST) can stimulate tumor necrosis factor alpha (TNF-α) release and induce apoptosis. In this study, we compared the behavior of hepatocytes invaded by three L. monocytogenes serotypes (LM-4a, LM-4b and LM-1/2a) and by ST to understand which bacterium is more effective in the infectious process. We quantified TNF-α release by ELISA, apoptosis rates by annexin V (early apoptosis) and TUNEL (late apoptosis) techniques. The cell morphology was studied too. TNF-α release rate was highest in ST-invaded hepatocytes. ST and LM-1/2a induced the highest apoptosis production rates evaluated by TUNEL. LM-4b produced the highest apoptosis rate measured by annexin. Invaded hepatocytes presented various morphological alterations. Overall, LM-4b and LM-1/2a proved to be the most efficient at cell invasion, although ST adapted faster to the environment and induced earlier hepatocyte TNF-α release.
RESUMO
A invasão de hepatócitos por Listeria monocytogenes (LM) e Salmonella Typhimurium (ST) pode estimular a liberação do Fator de Necrose Tumoral (TNF-α) e induzir a apoptose celular. Neste estudo comparamos o comportamento de hepatócitos invadidos por três sorotipos de L. monocytogenes (LM-4a, LM-4b e LM-1/2a) e por ST para entender qual bacteria é mais efetiva no processo infeccioso. Nós quantificamos a liberação de TNF-α pelos hepatócitos por ELISA e as taxas de apoptose pelas técnicas de anexina V (apoptose precoce) e TUNEL (apoptose tardia). A morfologia das células foi estudada também. A taxa de liberação de TNF-α foi mais alta em hepatócitos invadidos por ST. ST e LM-1/2a induziram as maiores taxas de apoptose pelo método TUNEL, enquanto LM-4b produziu as maiores taxas de apoptose por anexina V. Os hepatócitos invadidos apresentaram várias alterações morfológicas. Na análise do conjunto de dados, os sorotipos LM-4b e LM-1/2a provaram ser os mais eficientes na invasão celular, enquanto que ST adaptou-se mais rápido ao meio e induziu a liberação precoce de TNF-α pelos hepatócitos.
Full text:
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Index:
LILACS (Americas)
Main subject:
Salmonella typhimurium
/
Tumor Necrosis Factor-alpha
/
Apoptosis
/
Hepatocytes
/
Listeria monocytogenes
Limits:
Animals
Language:
English
Journal:
Rev. Inst. Med. Trop. Säo Paulo
Journal subject:
Tropical Medicine
Year:
2011
Type:
Article
Affiliation country:
Brazil
Institution/Affiliation country:
University of Sao Paulo/BR
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