TNFalpha induces rapid activation and nuclear translocation of telomerase in human lymphocytes.
Maintenance of telomeres regulates chromosomal stability and cellular mitosis through a checkpoint mechanism. Continuous cell proliferation requires telomerase to maintain chromosomal stability and to counteract the cellular mitotic clock. Importantly, nuclear expression of telomerase activity is required for elongation of telomere sequences. In this study, we show that tumor necrosis factor alpha (TNFalpha) induces telomerase activity in the cytoplasm of peripheral blood lymphocytes (PBL) at 60 min, followed by translocation of activated telomerase to the nucleus at 120 min. Conversely, the phosphoinositol 3-kinase (PI3K) inhibitor wortmannin blocks TNFalpha-induced activation of telomerase, whereas the specific NF-kappaB translocation inhibitor SN-50 blocks TNFalpha-induced nuclear translocation of activated telomerase. These studies suggest that activation and nuclear translocation of telomerase are regulated by PI3K/Akt/NF-kappaB signaling pathways in PBL.
Akiyama
Masaharu
M
Department of Pediatrics, Jikei University School of Medicine, Tokyo 105-8461, Japan. makiyama@jikei.ac.jp
Yamada
Osamu
O
Hideshima
Teru
T
Yanagisawa
Takaaki
T
Yokoi
Kentaro
K
Fujisawa
Kohji
K
Eto
Yoshikatsu
Y
Yamada
Hisashi
H
Anderson
Kenneth C
KC
D021581:Active Transport, Cell Nucleus; D002467:Cell Nucleus / Q000201:enzymology*; D002478:Cells, Cultured; D004789:Enzyme Activation; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D019098:Telomerase / Q000032:analysis / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D016328:NF-kappa B; D019869:Phosphatidylinositol 3-Kinases; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; D019098:Telomerase; D014409:Tumor Necrosis Factor-alpha; C494918:AKT1 protein, human