Abstract:BackgroundAcetaminophen (APAP) is a commonly used analgesic. However, its use is associated with drug-induced liver injury (DILI). It is a prominent cause of acute liver failure, with APAP hepatotoxicity far exceeding other causes of acute liver failure in the United States. In order to improve its safe use this study aimed to identify individuals at risk for DILI prior to drug treatment by searching for non-genetic serum markers in healthy subjects susceptible to APAP-induced liver injury (AILI).MethodsHealth… Show more
“…29,37 The compounds were tested over a 48-h exposure period at several concentrations that were relevant to their exposure in vivo or that had been shown to cause hepatocellular injury in vitro. We then examined their immune-mediated (LPS induced) and direct effects (without LPS) on the production of key cytokines, namely TNF-α and IL-6, and metabolic capacity as represented by Cyp3A activity.…”
Section: Discussionmentioning
confidence: 99%
“…Notably, APAP is another compound known to be associated with immune-mediated enhanced hepatotoxic events leading to severe liver injury and liver failure in some individuals. 37 Although it is well established in the literature that APAP is metabolically activated to a reactive metabolite (N-acetyl-p-benzoquinone imine), which depletes glutathione as a key initiating event leading to oxidative stress and hepatocellular injury, our results provide confirmation that there may be secondary pathways involved in its hepatotoxic mechanism, such as changes in cytokine profiles and metabolic capacity, that may be responsible for enhancement of toxicity in LPS-activated HKCCs, outside the classical APAP-induced cytotoxic effects from N-acetyl-p-benzoquinone imine, formation. Notably, the “idiosyncratic” nature of the severity of APAP toxicity in some patients has been linked to the patient's adaptive immune responses, suggesting that it too may fall into a category of a “TVX-like” mechanism.…”
Section: Discussionmentioning
confidence: 99%
“…Notably, the “idiosyncratic” nature of the severity of APAP toxicity in some patients has been linked to the patient's adaptive immune responses, suggesting that it too may fall into a category of a “TVX-like” mechanism. 15,37 …”
Immune-mediated drug-induced hepatotoxicity is often unrecognized as a potential mode of action due to the lack of appropriate in vitro models. We have established an in vitro rat donor-matched hepatocyte and Kupffer cell co-culture (HKCC) model to study immune-related responses to drug exposure. Optimal cell culture conditions were identified for the maintenance of co-cultures based on cell longevity, monolayer integrity, and cytokine response after lipopolysaccharide (LPS) exposure. Hepatocyte monocultures and HKCCs were then used to test a subset of compounds associated with hepatotoxic effects with or without LPS. Cytokine levels and metabolic activity (cytochrome P450 3A [Cyp3A]) were measured after a 48-h exposure to monitor endotoxin-induced changes in acute phase and functional end points. LPS-activated HKCCs, but not hepatocyte monocultures, treated with trovafloxacin or acetaminophen, compounds associated with immune-mediated hepatotoxicity, showed LPS-dependent decreases in interleukin-6 production with concomitant increases in Cyp3A activity. Differential endotoxinand model-dependent alterations were observed in cytokine profiles and Cyp3A activity levels that corresponded to specific compounds. These results indicate the utility of the HKCC model system to discern compound-specific effects that may lead to enhanced or mitigate hepatocellular injury due to innate or adaptive immune responses.
“…29,37 The compounds were tested over a 48-h exposure period at several concentrations that were relevant to their exposure in vivo or that had been shown to cause hepatocellular injury in vitro. We then examined their immune-mediated (LPS induced) and direct effects (without LPS) on the production of key cytokines, namely TNF-α and IL-6, and metabolic capacity as represented by Cyp3A activity.…”
Section: Discussionmentioning
confidence: 99%
“…Notably, APAP is another compound known to be associated with immune-mediated enhanced hepatotoxic events leading to severe liver injury and liver failure in some individuals. 37 Although it is well established in the literature that APAP is metabolically activated to a reactive metabolite (N-acetyl-p-benzoquinone imine), which depletes glutathione as a key initiating event leading to oxidative stress and hepatocellular injury, our results provide confirmation that there may be secondary pathways involved in its hepatotoxic mechanism, such as changes in cytokine profiles and metabolic capacity, that may be responsible for enhancement of toxicity in LPS-activated HKCCs, outside the classical APAP-induced cytotoxic effects from N-acetyl-p-benzoquinone imine, formation. Notably, the “idiosyncratic” nature of the severity of APAP toxicity in some patients has been linked to the patient's adaptive immune responses, suggesting that it too may fall into a category of a “TVX-like” mechanism.…”
Section: Discussionmentioning
confidence: 99%
“…Notably, the “idiosyncratic” nature of the severity of APAP toxicity in some patients has been linked to the patient's adaptive immune responses, suggesting that it too may fall into a category of a “TVX-like” mechanism. 15,37 …”
Immune-mediated drug-induced hepatotoxicity is often unrecognized as a potential mode of action due to the lack of appropriate in vitro models. We have established an in vitro rat donor-matched hepatocyte and Kupffer cell co-culture (HKCC) model to study immune-related responses to drug exposure. Optimal cell culture conditions were identified for the maintenance of co-cultures based on cell longevity, monolayer integrity, and cytokine response after lipopolysaccharide (LPS) exposure. Hepatocyte monocultures and HKCCs were then used to test a subset of compounds associated with hepatotoxic effects with or without LPS. Cytokine levels and metabolic activity (cytochrome P450 3A [Cyp3A]) were measured after a 48-h exposure to monitor endotoxin-induced changes in acute phase and functional end points. LPS-activated HKCCs, but not hepatocyte monocultures, treated with trovafloxacin or acetaminophen, compounds associated with immune-mediated hepatotoxicity, showed LPS-dependent decreases in interleukin-6 production with concomitant increases in Cyp3A activity. Differential endotoxinand model-dependent alterations were observed in cytokine profiles and Cyp3A activity levels that corresponded to specific compounds. These results indicate the utility of the HKCC model system to discern compound-specific effects that may lead to enhanced or mitigate hepatocellular injury due to innate or adaptive immune responses.
“…Екзогенно-токсичне уражен-ня печінки виникає внаслідок впливу низки різноманітних фізичних і хімічних факторів, серед яких -медикаментозні препарати, ал-коголь, засоби побутової хімії, токсини гри-бів тощо [2,9]. На сьогодні токсичні гепатити становлять одну з найсерйозніших медико-соціальних проблем у світі, що зумовлено не тільки високим рівнем захворюваності серед населення, але й суттєвими економічними за-тратами на діагностичний пошук та лікуван-ня [1,4,6,18].…”
Section: метою роботи було дослідження активності маркерних ензимів сunclassified
Чернівецький національний університет імені Юрія Федьковича, Інститут біології, хімії та біоресурсів, кафедра біохімії та біотехнології, вул. Коцюбинського, 2, м. Чернівці, 58000, Україна
“…Показано, что нарушения работы системы энергообеспечения выступают вторичным звеном патогенеза ряда заболеваний [4]. Учитывая рост числа регистрируемых побочных (токсических) эффектов лекарственных препаратов и зависимость функциональной активности печени от эффективности работы системы энергообеспечения гепатоцитов [5,6], исследование механизмов, определяющих развитие энергетического дисбаланса, особенно актуально. В контексте изучения биохимических механизмов нарушения функций печени при лекарственных или токсических гепатитах [7], удобным модельным токсином является ацетаминофен, который широко применяется в медицинской практике в качестве анальгетического и пиральгетического средства, а в случае передозировки вызывает существенные повреждения центральнолобулярных областей печени [8].…”
Activity of isocitrate dehydrogenase, a-ketoglutarate dehydrogenase, malate dehydrogenase, and the NAD+/NADН ratio were studied in the liver mitochondrial fraction of rats with toxic hepatitis induced by acetaminophen under conditions of alimentary protein deprivation. Acetaminophen-induced hepatitis was characterized by a decrease of isocitrate dehydrogenase, a-ketoglutarate dehydrogenase and malate dehydrogenase activities, while the mitochondrial NAD+/NADН ratio remained at the control level. Modeling of acetaminophen-induced hepatitis in rats with alimentary protein caused a more pronounced decrease in the activity of NAD+-dependent dehydrogenases studied and a 2.2-fold increase of the mitochondrial NAD+/NADН ratio. This suggests that alimentary protein deprivation potentiated drug-induced liver damage
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