Relocation of truncated bid plays an important role in suppression of tumor necrosis factor alpha induced apoptosis in hepatocytes isolated from transgenic mouse.
OBJECTIVE
Tumor necrosis factor alpha (TNFalpha) induces apoptosis in murine hepatocytes pretreated with Actinomycin D (ActD) in vitro. This study sought to clarify the relationship between hepatic energy status and TNFalpha-induced hepatocyte apoptosis, using mice transgenic for creatine kinase (CK) expression.


METHODS
Hepatocytes from CK transgenic mice were cultured with or without creatine (Cr). The concentrations of ATP and phosphocreatine (PCr) in hepatocytes were measured by high-pressure liquid chromatography. Sixteen hours after treatment with ActD and TNFalpha, we evaluated cell viability of these hepatocytes. We examined truncated Bid and cytochrome c by immunoblot analysis.


RESULTS
Six hours after cell isolation, the concentration of PCr in CK transgenic hepatocytes cultured with Cr increased to 8.23 +/- 0.01 microg/mg protein, while that of hepatocytes cultured without Cr was lower than 0.1 microg/mg protein. In hepatocytes cultured without Cr, ActD and TNFalpha treatment induced massive cell death, while hepatocytes cultured with Cr maintained greater than 80% viability. In CK transgenic hepatocytes cultured with Cr, truncated Bid relocation to mitochondria was highly suppressed, compared to CK transgenic hepatocytes cultured without Cr.


CONCLUSIONS
PCr accumulation may prevent TNFalpha-induced apoptosis in murine hepatocytes by suppression of truncated Bid targeting to mitochondria.
Shiotani
Tomohiro
T
Department of Gastroenterological Surgery, Kyoto University Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto, Japan.
Yamanokuchi
Satoshi
S
Hatano
Etsuro
E
Ikai
Iwao
I
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D051023:BH3 Interacting Domain Death Agonist Protein; D002352:Carrier Proteins / Q000378:metabolism*; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002478:Cells, Cultured; D003401:Creatine / Q000494:pharmacology; D003402:Creatine Kinase / Q000378:metabolism; D045304:Cytochromes c / Q000378:metabolism; D004594:Electrophysiology; D004789:Enzyme Activation / Q000187:drug effects; D022781:Hepatocytes / Q000187:drug effects* / Q000502:physiology*; D051379:Mice; D008822:Mice, Transgenic; D008928:Mitochondria / Q000378:metabolism / Q000502:physiology; D010446:Peptide Fragments / Q000378:metabolism; D010539:Permeability; D010725:Phosphocreatine / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D014018:Tissue Distribution; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D051020:bcl-X Protein
D051023:BH3 Interacting Domain Death Agonist Protein; C494812:Bcl2l1 protein, mouse; C494815:Bid protein, mouse; D002352:Carrier Proteins; D010446:Peptide Fragments; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D014409:Tumor Necrosis Factor-alpha; D051020:bcl-X Protein; D010725:Phosphocreatine; D045304:Cytochromes c; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D003402:Creatine Kinase; C505409:Casp3 protein, mouse; D053148:Caspase 3; D020169:Caspases; D003401:Creatine