Neutropenia and neutrophil dysfunction are common in many diseases, although their etiology is often unclear. Previous views held that there was a single ER enzyme, glucose-6-phosphatase–α (G6Pase-α), whose activity — limited to the liver, kidney, and intestine — was solely responsible for the final stages of gluconeogenesis and glycogenolysis, in which glucose-6-phosphate (G6P) is hydrolyzed to glucose for release to the blood. Recently, we characterized a second G6Pase activity, that of G6Pase-β (also known as G6PC), which is also capable of hydrolyzing G6P to glucose but is ubiquitously expressed and not implicated in interprandial blood glucose homeostasis. We now report that the absence of G6Pase-β led to neutropenia; defects in neutrophil respiratory burst, chemotaxis, and calcium flux; and increased susceptibility to bacterial infection. Consistent with this, G6Pase-β–deficient (G6pc3–/–) mice with experimental peritonitis exhibited increased expression of the glucose-regulated proteins upregulated during ER stress in their neutrophils and bone marrow, and the G6pc3–/– neutrophils exhibited an enhanced rate of apoptosis. Our results define a molecular pathway to neutropenia and neutrophil dysfunction of previously unknown etiology, providing a potential model for the treatment of these conditions.
Yuk Yin Cheung, So Youn Kim, Wai Han Yiu, Chi-Jiunn Pan, Hyun-Sik Jun, Robert A. Ruef, Eric J. Lee, Heiner Westphal, Brian C. Mansfield, Janice Y. Chou
Guidelines: The Editorial Board will only consider letters that we deem relevant and of interest to our readers. We will not post data that have not been subjected to peer review, nor will we post letters that are essentially a reiteration of another letter. All accepted letters will be posted on our website within one week of acceptance. We reserve the right to edit any letter for length, content, and clarity. Authors of all accepted letters will be asked to preview any changes. Authors will be notified by e-mail if their letters were not accepted. As this is a final decision, no appeals will be considered.
Specific requirements: All letters must be 400 words or fewer. You may enter the letter as plain text or HTML. The author's name and e-mail address are required, and will be posted with the letter. All possible conflicts of interest must be noted, even if they are not posted. If you wish to include a figure (keep in mind that non-peer-reviewed data will not be posted), please contact the editors directly at firstname.lastname@example.org.