TY - JOUR
T1 - Decreased glycogen synthase kinase 3-beta levels and related physiological changes in Bacillus anthracis lethal toxin-treated macrophages
AU - Tucker, Amy E.
AU - Salles, Isabelle I.
AU - Voth, Daniel E.
AU - Ortiz-Leduc, William
AU - Wang, Han
AU - Dozmorov, Igor
AU - Centola, Michael
AU - Ballard, Jimmy D.
PY - 2003/8/1
Y1 - 2003/8/1
N2 - The lethal factor (LF) component of Bacillus anthracis lethal toxin (LeTx) cleaves mitogen activated protein kinase kinases (MAPKKs) in a variety of different cell types, yet only macrophages are rapidly killed by this toxin. The reason for this selective killing is unclear, but suggests other factors may also be involved in LeTx intoxication. In the current study, DNA membrane arrays were used to identify broad changes in macrophage physiology after treatment with LeTx. Expression of genes regulated by MAPKK activity did not change significantly, yet a series of genes under glycogen synthase kinase-3-β (GSK-3β) regulation changed expression following LeTx treatment. Correlating with these transcriptional changes GSK-3β was found to be below detectable levels in toxin-treated cells and an inhibitor of GSK-3β, LiCl, sensitized resistant IC-21 macrophages to LeTx. In addition, zebrafish embryos treated with LeTx showed signs of delayed pigmentation and cardiac hypertrophy; both processes are subject to regulation by GSK-3β. A putative compensatory response to loss of GSK-3β was indicated by differential expression of three motor proteins following toxin treatment and Kif1C, a motor protein involved in sensitivity to LeTx, increased expression in toxin-sensitive cells yet decreased in resistant cells following toxin treatment. Differential expression of microtubule-associating proteins and a decrease in the level of cellular tubulin were detected in LeTx-treated cells, both of which can result from loss of GSK-3β activity. These data provide new information on LeTx's overall influence on macrophage physiology and suggest loss of GSK-3β contributes to cytotoxicity.
AB - The lethal factor (LF) component of Bacillus anthracis lethal toxin (LeTx) cleaves mitogen activated protein kinase kinases (MAPKKs) in a variety of different cell types, yet only macrophages are rapidly killed by this toxin. The reason for this selective killing is unclear, but suggests other factors may also be involved in LeTx intoxication. In the current study, DNA membrane arrays were used to identify broad changes in macrophage physiology after treatment with LeTx. Expression of genes regulated by MAPKK activity did not change significantly, yet a series of genes under glycogen synthase kinase-3-β (GSK-3β) regulation changed expression following LeTx treatment. Correlating with these transcriptional changes GSK-3β was found to be below detectable levels in toxin-treated cells and an inhibitor of GSK-3β, LiCl, sensitized resistant IC-21 macrophages to LeTx. In addition, zebrafish embryos treated with LeTx showed signs of delayed pigmentation and cardiac hypertrophy; both processes are subject to regulation by GSK-3β. A putative compensatory response to loss of GSK-3β was indicated by differential expression of three motor proteins following toxin treatment and Kif1C, a motor protein involved in sensitivity to LeTx, increased expression in toxin-sensitive cells yet decreased in resistant cells following toxin treatment. Differential expression of microtubule-associating proteins and a decrease in the level of cellular tubulin were detected in LeTx-treated cells, both of which can result from loss of GSK-3β activity. These data provide new information on LeTx's overall influence on macrophage physiology and suggest loss of GSK-3β contributes to cytotoxicity.
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U2 - 10.1046/j.1462-5822.2003.00298.x
DO - 10.1046/j.1462-5822.2003.00298.x
M3 - Article
C2 - 12864812
AN - SCOPUS:0041695260
SN - 1462-5814
VL - 5
SP - 523
EP - 532
JO - Cellular Microbiology
JF - Cellular Microbiology
IS - 8
ER -