TY - JOUR
T1 - Tumor necrosis factor-α and CD95 ligation suppress erythropoiesis in Fanconi anemia C gene knockout mice
AU - Otsuki, Tetsuya
AU - Nagakura, Shoichi
AU - Wang, Jianxiang
AU - Bloom, Michael
AU - Grompe, Markus
AU - Liu, Johnson M.
PY - 1999
Y1 - 1999
N2 - Fanconi anemia (FA) is a genetic syndrome predisposing to hematopoietic failure. Little is known about the pathophysiology of FA, except that tumor necrosis factor-α (TNF-α) is overexpressed in patients. FA group C (Fac) gene knockout mice have been developed in order to model the human disease, but the mice do not spontaneously exhibit aplasia. To investigate secondary influences on hematopoiesis in the Fac-null mice, we studied the sensitivity of hematopoietic progenitor cells (HPC) to death receptor triggering by TNF- α and Fas receptor (CD95) ligation. Previously we had found that overexpression of a human FAC transgene protects hematopoietic progenitors from Fas-mediated apoptosis (Wang et al., 1998, Cancer Res 58:3538-3541). In the present experiments with Fac-null mice, growth of erythroid burst- forming units (BFU-E) was significantly inhibited by TNF-α and CD95 ligation. Flow cytometric analysis revealed that CD95 was induced more readily in the Fac-null CD34+ cell fraction. Apoptosis induced by TNF-α alone or with CD95 ligation also occurred more frequently in null mouse HPC. We then bred null mice against transgenic mice overexpressing TNF-α (at serum levels in the range of 100 pg/ml). Resultant Fac-null mice that overexpressed TNF-α not only yielded decreased numbers of BFU-E but also expressed higher levels of CD95 in the CD34+ fraction. We conclude that mutation in the Fac protein induces heightened sensitivity to TNF-α and Fas receptor ligation, results that may explain the mechanism of anemia in FA-C patients.
AB - Fanconi anemia (FA) is a genetic syndrome predisposing to hematopoietic failure. Little is known about the pathophysiology of FA, except that tumor necrosis factor-α (TNF-α) is overexpressed in patients. FA group C (Fac) gene knockout mice have been developed in order to model the human disease, but the mice do not spontaneously exhibit aplasia. To investigate secondary influences on hematopoiesis in the Fac-null mice, we studied the sensitivity of hematopoietic progenitor cells (HPC) to death receptor triggering by TNF- α and Fas receptor (CD95) ligation. Previously we had found that overexpression of a human FAC transgene protects hematopoietic progenitors from Fas-mediated apoptosis (Wang et al., 1998, Cancer Res 58:3538-3541). In the present experiments with Fac-null mice, growth of erythroid burst- forming units (BFU-E) was significantly inhibited by TNF-α and CD95 ligation. Flow cytometric analysis revealed that CD95 was induced more readily in the Fac-null CD34+ cell fraction. Apoptosis induced by TNF-α alone or with CD95 ligation also occurred more frequently in null mouse HPC. We then bred null mice against transgenic mice overexpressing TNF-α (at serum levels in the range of 100 pg/ml). Resultant Fac-null mice that overexpressed TNF-α not only yielded decreased numbers of BFU-E but also expressed higher levels of CD95 in the CD34+ fraction. We conclude that mutation in the Fac protein induces heightened sensitivity to TNF-α and Fas receptor ligation, results that may explain the mechanism of anemia in FA-C patients.
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U2 - 10.1002/(SICI)1097-4652(199904)179:1<79::AID-JCP10>3.0.CO;2-O
DO - 10.1002/(SICI)1097-4652(199904)179:1<79::AID-JCP10>3.0.CO;2-O
M3 - Article
C2 - 10082135
AN - SCOPUS:0032976437
SN - 0021-9541
VL - 179
SP - 79
EP - 86
JO - Journal of Cellular Physiology
JF - Journal of Cellular Physiology
IS - 1
ER -