Bcl3 prevents acute inflammatory lung injury in mice by restraining emergency granulopoiesis
Daniel Kreisel, Seiichiro Sugimoto, Jeremy Tietjens, Jihong Zhu, Sumiharu Yamamoto, Alexander S. Krupnick, Ruaidhri J. Carmody, Andrew E. Gelman
Daniel Kreisel, Seiichiro Sugimoto, Jeremy Tietjens, Jihong Zhu, Sumiharu Yamamoto, Alexander S. Krupnick, Ruaidhri J. Carmody, Andrew E. Gelman
View: Text | PDF
Research Article Inflammation

Bcl3 prevents acute inflammatory lung injury in mice by restraining emergency granulopoiesis

Abstract

Granulocytes are pivotal regulators of tissue injury. However, the transcriptional mechanisms that regulate granulopoiesis under inflammatory conditions are poorly understood. Here we show that the transcriptional coregulator B cell leukemia/lymphoma 3 (Bcl3) limits granulopoiesis under emergency (i.e., inflammatory) conditions, but not homeostatic conditions. Treatment of mouse myeloid progenitors with G-CSF — serum concentrations of which rise under inflammatory conditions — rapidly increased Bcl3 transcript accumulation in a STAT3-dependent manner. Bcl3-deficient myeloid progenitors demonstrated an enhanced capacity to proliferate and differentiate into granulocytes following G-CSF stimulation, whereas the accumulation of Bcl3 protein attenuated granulopoiesis in an NF-κB p50–dependent manner. In a clinically relevant model of transplant-mediated lung ischemia reperfusion injury, expression of Bcl3 in recipients inhibited emergency granulopoiesis and limited acute graft damage. These data demonstrate a critical role for Bcl3 in regulating emergency granulopoiesis and suggest that targeting the differentiation of myeloid progenitors may be a therapeutic strategy for preventing inflammatory lung injury.

Authors

Daniel Kreisel, Seiichiro Sugimoto, Jeremy Tietjens, Jihong Zhu, Sumiharu Yamamoto, Alexander S. Krupnick, Ruaidhri J. Carmody, Andrew E. Gelman

×

Figure 5

The dynamics and effects of Bcl3 expression in myeloid progenitors.

Options: View larger image (or click on image) Download as PowerPoint
The dynamics and effects of Bcl3 expression in myeloid progenitors. (A) ...
(A) Representative (n = 4) Bcl3 transcript expression in B6 myeloid progenitors or granulocytes (Gran) before (control) and after 18 hours of stimulation with 10 ng/ml of indicated cytokines in liquid culture. (B) Representative (n = 4) Bcl3 transcript level expression in myeloid progenitors and granulocytes purified from resting B6 mice, B6 → B6 (B6) treated with control Ig or G-CSF–specific antibodies 18 hours following transplantation. (C) Representative (n = 2) Bcl3 transcript accumulation in G-CSFRΔ715F myeloid cell progenitors. (D) Representative (n = 2) analysis of STAT3 association with Bcl3 promoter. Lin– B6 bone marrow cells were stimulated with indicated cytokines. Chromatin immunoprecipitation was then conducted with STAT3-specific or control antibodies, and amplification was performed with primers specific for an enhancer region of Bcl3. (E) Assessment of Bcl3 ectopic expression on NF-κB p50 protein accumulation. Lin– B6 bone marrow cells were transfected with MSCV, MSCV-Bcl3 (encoding N-FLAG Bcl3), or MSCV NF-κB p50 (encoding N-FLAG NF-κB p50). Nuclear protein was extracted, immunoblotted, and probed with FLAG–, NF-κB p50–, Oct-1–, and β-actin–specific antibodies. Results are representative of 3 independent experiments. (F) Top: Representative FACS analysis (n = 5). Numbers denote percent abundance of granulocytes in Lin– bone marrow cell cultures following 3 days of stimulation with indicated cytokines. Bottom: Mean percent abundance of granulocytes calculated from 5 independently conducted cultures derived from data in top panel. Data represent mean ± SD. *P < 0.05; **P < 0.01.