Reactive oxygen species derived from NADPH oxidase system is not essential for liver regeneration after partial...

There is suggestive evidence that reactive oxygen species may play a role in the initiation of liver regeneration via a kupffer cell-mediated mechanism involving TNFa and NF-kappa B. In mammalian cells, a major source of reactive oxygen species derives from the membrane-bound NADPH oxidase system (no protein de novo synthesis is required) and it is known that the low levels of oxidants produced through NADPH oxidase play a role in liver cell proliferation because of peroxisome proliferators.

We used knockout mice lacking Cybb: subunit of NADPH oxidase to determine whether signaling at the start of liver regeneration after partial hepatectomy (PH) involves reactive oxygen species produced through NADPH oxidase and to analyze in more detail the abnormalities caused by lack of its component, which is required for the initiation of liver regeneration.

Lack of Cybb had little effect on NF-kappa B and STAT3 binding, and no effect in TNFa and interleukin-6 production after PH. Cybb KO mice had normal liver structure and similar levels of hepatocyte DNA replication as those of wild type mice.

We conclude that NADPH oxidase is not necessary for liver regeneration after PH. It is likely that there is a potential pathway not including NADPH oxidase to activate NF-kappa B and STAT3 binding for the initiation of liver regeneration after PH.