In:
Blood, American Society of Hematology, Vol. 117, No. 14 ( 2011-04-07), p. 3881-3892
Abstract:
G6PC3 (or glucose-6-phosphatase-β) deficiency underlies a congenital neutropenia syndrome in which neutrophils exhibit enhanced endoplasmic reticulum (ER) stress, increased apoptosis, impaired energy homeostasis, and impaired functionality. Here we show that murine G6pc3−/− neutrophils undergoing ER stress activate protein kinase-like ER kinase and phosphatidylinositol 3,4,5-trisphosphate/Akt signaling pathways, and that neutrophil apoptosis is mediated in part by the intrinsic mitochondrial pathway. In G6PC3-deficient patients, granulocyte colony-stimulating factor (G-CSF) improves neutropenia, but its impact on neutrophil apoptosis and dysfunction is unknown. We now show that G-CSF delays neutrophil apoptosis in vitro by modulating apoptotic mediators. However, G6pc3−/− neutrophils in culture exhibit accelerated apoptosis compared with wild-type neutrophils both in the presence or absence of G-CSF. Limiting glucose (0.6mM) accelerates apoptosis but is more pronounced for wild-type neutrophils, leading to similar survival profiles for both neutrophil populations. In vivo G-CSF therapy completely corrects neutropenia and normalizes levels of p-Akt, phosphatidylinositol 3,4,5-trisphosphate, and active caspase-3. Neutrophils from in vivo G-CSF–treated G6pc3−/− mice exhibit increased glucose uptake and elevated intracellular levels of G6P, lactate, and adenosine-5′-triphosphate, leading to improved functionality. Together, the results strongly suggest that G-CSF improves G6pc3−/− neutrophil survival by modulating apoptotic mediators and rectifies function by enhancing energy homeostasis.
Type of Medium:
Online Resource
ISSN:
0006-4971
,
1528-0020
DOI:
10.1182/blood-2010-08-302059
Language:
English
Publisher:
American Society of Hematology
Publication Date:
2011
detail.hit.zdb_id:
1468538-3
detail.hit.zdb_id:
80069-7
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