Hepatocyte-specific deletion of the antiapoptotic protein myeloid cell leukemia-1 triggers proliferation and hepatocarcinogenesis in mice
Regulation of hepatocellular apoptosis is crucial for liver homeostasis. Increased sensitivity of hepatocytes toward apoptosis results in chronic liver injury, whereas apoptosis resistance is linked to hepatocarcinogenesis and nonresponsiveness to therapy-induced cell death. Recently, we have demonstrated an essential role of the antiapoptotic Bcl-2 family member Myeloid cell leukemia-1 (Mcl-1) in hepatocyte survival. In mice lacking Mcl-1 specifically in hepatocytes (Mcl-1Δhep), spontaneous apoptosis caused severe liver damage. Here, we demonstrate that chronically increased apoptosis of hepatocytes coincides with strong hepatocyte proliferation resulting in hepatocellular carcinoma (HCC).…
Knockout of myeloid cell leukemia-1 induces liver damage and increases apoptosis susceptibility of murine hepatocytes
Apoptosis, or programmed cell death, regulates tissue development and homeostasis in multi-cellular organisms. Extrinsic or intrinsic death signals activate pro-apoptotic pathways, resulting in the activation of caspases and finally in cell death. An important event during apoptosis process is the permeabilization of the outer mitochondrial membrane (OMM). Integrity of the OMM is regulated by the Bcl-2 protein family, which is divided into three groups: anti-apoptotic members Bcl-2, Bcl-xL and myeloid cell leukemia-1 (Mcl-1), pro-apoptotic multidomain members Bax and Bak, and pro-apoptotic BH3-only proteins. Mitochondrial activation is regulated by selective interactions of Bcl-2 proteins v…