BACKGROUND/AIMS: β-hydroxybutyrate (BHBA) is the major component of ketone bodies in ketosis. Dairy cows with ketosis often undergo oxidative stress. BHBA is related to the inflammation involved in other diseases of dairy cattle. However, whether BHBA can induce inflammatory injury in dairy cow hepatocytes and the potential mechanism of this induction are not clear. The NF-κB pathway plays a vital role in the inflammatory response. METHODS: Therefore, this study evaluated the oxidative stress, pro-inflammatory factors and NF-κB pathway in cultured calf hepatocytes treated with different concentrations of BHBA, pyrrolidine dithiocarbamate (PDTC, an NF-κB pathway inhibitor) and N-acetylcysteine (NAC, antioxidant). RESULTS: The results showed that BHBA could significantly increase the levels of oxidation indicators (MDA, NO and iNOS), whereas the levels of antioxidation indicators (GSH-Px, CAT and SOD) were markedly decreased in hepatocytes. The IKKβ activity and phospho-IκBα (p-IκBα) contents were increased in BHBA-treated hepatocytes. This increase was accompanied by the increased expression level and transcription activity of p65. The expression levels of NF-κB-regulated inflammatory cytokines, namely TNF-α, IL-6 and IL-1β, were markedly increased after BHBA treatment, while significantly decreased after NAC treatment. However, the p-IκBα level and the expression and activity of p65 and its target genes were markedly decreased in the PDTC + BHBA group compared with the BHBA (1.8 mM) group. Moreover, immunocytofluorescence of p65 showed a similar trend. CONCLUSION: The present data indicate that higher concentrations of BHBA can induce cattle hepatocyte inflammatory injury through the NF-κB signaling pathway, which may be activated by oxidative stress.
BACKGROUND/AIMS: β-hydroxybutyrate (BHBA) is the major component of ketone bodies in ketosis. Dairy cows with ketosis often undergo oxidative stress. BHBA is related to the inflammation involved in other diseases of dairy cattle. However, whether BHBA can induce inflammatory injury in dairy cow hepatocytes and the potential mechanism of this induction are not clear. The NF-κB pathway plays a vital role in the inflammatory response. METHODS: Therefore, this study evaluated the oxidative stress, pro-inflammatory factors and NF-κB pathway in cultured calf hepatocytes treated with different concentrations of BHBA, pyrrolidine dithiocarbamate (PDTC, an NF-κB pathway inhibitor) and N-acetylcysteine (NAC, antioxidant). RESULTS: The results showed that BHBA could significantly increase the levels of oxidation indicators (MDA, NO and iNOS), whereas the levels of antioxidation indicators (GSH-Px, CAT and SOD) were markedly decreased in hepatocytes. The IKKβ activity and phospho-IκBα (p-IκBα) contents were increased in BHBA-treated hepatocytes. This increase was accompanied by the increased expression level and transcription activity of p65. The expression levels of NF-κB-regulated inflammatory cytokines, namely TNF-α, IL-6 and IL-1β, were markedly increased after BHBA treatment, while significantly decreased after NAC treatment. However, the p-IκBα level and the expression and activity of p65 and its target genes were markedly decreased in the PDTC + BHBA group compared with the BHBA (1.8 mM) group. Moreover, immunocytofluorescence of p65 showed a similar trend. CONCLUSION: The present data indicate that higher concentrations of BHBA can induce cattle hepatocyte inflammatory injury through the NF-κB signaling pathway, which may be activated by oxidative stress.
Authors: M Jawad Khan; Carolina B Jacometo; Mario Vailati Riboni; Erminio Trevisi; Daniel E Graugnard; Marcio N Corrêa; Juan J Loor Journal: Funct Integr Genomics Date: 2015-05-05 Impact factor: 3.410