Kim So Youn, Nguyen Andrew D, Gao Ji-Liang, Murphy Philip M, Mansfield Brian C, Chou Janice Yang
Section on Cellular Differentiation, Heritable Disorders Branch, NICHD, Molecular Signaling Section, Laboratory of Molecular Immunology, NIAID, National Institutes of Health, Bethesda, Maryland 20892, USA.
J Biol Chem. 2006 Sep 29;281(39):28794-801. doi: 10.1074/jbc.M604964200. Epub 2006 Aug 4.
Glycogen storage disease type Ib (GSD-Ib) is caused by a deficiency in the ubiquitously expressed glucose 6-phosphate transporter (Glc-6-PT). Glc-6-PT activity has been shown to be critical in the liver and kidney where a deficiency disrupts glucose homeostasis. GSD-Ib patients also have defects in the neutrophil respiratory burst, chemotaxis, and calcium flux. They also manifest neutropenia, but whether Glc-6-PT deficiency in the bone marrow underlies myeloid dysfunctions in GSD-Ib remains controversial. To address this, we transferred bone marrow from Glc-6-PT-deficient (Glc-6-PT(-/-)) mice to wild-type mice to generate chimeric mice (BM-Glc-6-PT(-/-)). As a control, we also transferred bone marrow between wild-type mice (BM-Glc-6-PT(+/+)). While BM-Glc-6-PT(+/+) mice have normal myeloid functions, BM-Glc-6-PT(-/-) mice manifest myeloid abnormalities characteristic of Glc-6-PT(-/-) mice. Both have impairments in their neutrophil respiratory burst, chemotaxis response, and calcium flux activities and exhibit neutropenia. In the bone marrow of BM-Glc-6-PT(-/-) and Glc-6-PT(-/-) mice, the numbers of myeloid progenitor cells are increased, while in the serum there is an increase in granulocyte colony-stimulating factor and chemokine KC levels. Moreover, in an experimental model of peritoneal inflammation, local production of KC and the related chemokine macrophage inflammatory protein-2 is decreased in both BM-Glc-6-PT(-/-) and Glc-6-PT(-/-) mice along with depressed peritoneal neutrophil accumulation. The neutrophil recruitment defect was less severe in BM-Glc-6-PT(-/-) mice than in Glc-6-PT(-/-) mice. These findings demonstrate that Glc-6-PT expression in bone marrow and neutrophils is required for normal myeloid functions and that non-marrow Glc-6-PT activity also influences some myeloid functions.
1b型糖原贮积病(GSD-Ib)是由普遍表达的葡萄糖6-磷酸转运体(Glc-6-PT)缺乏引起的。已证明Glc-6-PT活性在肝脏和肾脏中至关重要,其缺乏会破坏葡萄糖稳态。GSD-Ib患者的中性粒细胞呼吸爆发、趋化性和钙通量也存在缺陷。他们还表现出中性粒细胞减少,但骨髓中Glc-6-PT缺乏是否是GSD-Ib中髓系功能障碍的基础仍存在争议。为了解决这个问题,我们将来自Glc-6-PT缺陷(Glc-6-PT(-/-))小鼠的骨髓移植到野生型小鼠中以产生嵌合小鼠(BM-Glc-6-PT(-/-))。作为对照,我们也在野生型小鼠之间进行了骨髓移植(BM-Glc-6-PT(+/+))。虽然BM-Glc-6-PT(+/+)小鼠具有正常的髓系功能,但BM-Glc-6-PT(-/-)小鼠表现出Glc-6-PT(-/-)小鼠特有的髓系异常。两者在中性粒细胞呼吸爆发、趋化反应和钙通量活性方面均有损害,并表现出中性粒细胞减少。在BM-Glc-6-PT(-/-)和Glc-6-PT(-/-)小鼠的骨髓中,髓系祖细胞数量增加,而血清中粒细胞集落刺激因子和趋化因子KC水平升高。此外,在腹膜炎症的实验模型中,BM-Glc-6-PT(-/-)和Glc-6-PT(-/-)小鼠中KC和相关趋化因子巨噬细胞炎性蛋白-2的局部产生均减少,同时腹膜中性粒细胞积聚受到抑制。BM-Glc-6-PT(-/-)小鼠的中性粒细胞募集缺陷比Glc-6-PT(-/-)小鼠轻。这些发现表明,骨髓和中性粒细胞中Glc-6-PT的表达是正常髓系功能所必需的,并且非骨髓Glc-6-PT活性也影响一些髓系功能。