The homeobox transcription factor VentX controls human macrophage terminal differentiation and proinflammatory activation
Xiaoming Wu, … , Roger W. Giese, Zhenglun Zhu
Xiaoming Wu, … , Roger W. Giese, Zhenglun Zhu
Published June 13, 2011
Citation Information: J Clin Invest. 2011;121(7):2599-2613. https://doi.org/10.1172/JCI45556.
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Research Article Immunology

The homeobox transcription factor VentX controls human macrophage terminal differentiation and proinflammatory activation

Abstract

Macrophages are critical players in both innate and adaptive immunity. While the exogenous signaling events leading to the terminal differentiation of macrophages from monocytes have been studied extensively, the underlying intracellular transcriptional mechanisms remain poorly understood. Here we report that the homeobox transcription factor VentX plays a pivotal role in human macrophage terminal differentiation and proinflammatory function. Our study showed that VentX expression was upregulated upon human primary monocyte-to-macrophage differentiation induced by cytokines such as M-CSF, GM-CSF, and IL-3. Moreover, ablation of VentX expression in primary monocytes profoundly impaired their differentiation to macrophages, and ectopic expression of VentX in a myeloid progenitor cell line triggered its differentiation with prominent macrophage features. Further analysis revealed that VentX was pivotal for the proinflammatory response of terminally differentiated macrophages. Mechanistically, VentX was found to control expression of proteins key to macrophage differentiation and activation, including M-CSF receptor. Importantly, preliminary analysis of gene expression in leukocytes from patients with autoimmune diseases revealed a strong correlation between levels of VentX and those of proinflammatory cytokines. Our results provide mechanistic insight into the crucial roles of VentX in macrophage differentiation and proinflammatory activation and suggest that dysregulation of VentX may play a role in the pathogenesis of autoimmune diseases.

Authors

Xiaoming Wu, Hong Gao, Weixiong Ke, Roger W. Giese, Zhenglun Zhu

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Figure 5

VentX promotes proinflammatory response and inhibits proliferation in U937 cells.

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VentX promotes proinflammatory response and inhibits proliferation in U9...
U937 cell lines were treated as described in Figure 4. (A) Phagocytosis of DOX-treated U937 cells at 37°C. Red histogram represent GFP-expressing cells; green histogram represent GFP.VentX-expressing cells. Filled blue histogram represents background staining of cells not undergoing phagocytosis. (B) Effects of VentX expression on the mRNA level of proinflammatory cytokines. U937 cells were treated with 1 μg/ml LPS for 6 hours after 72 hours exposure to DOX. Real-time PCR was performed to determine mRNA levels of the indicated cytokines. Data are presented as the fold of elevation and are mean + SD of triplicates from 1 representative experiment. (C) Secreted IL-1β and TNF-α from U937 cell culture supernatants were determined with ELISA kits. U.D., undetectable. Data represent mean + SD of triplicates from 1 representative experiment. (D) Effects of VentX on growth of U937 cells. Cells (2 × 104) were seeded in 6-well plates and cultured for 5 days in the presence of 1.0 μg/ml DOX. Cell numbers at the indicated days were determined and plotted. (E) Cell cycle profiles of U937 cells expressing GFP or GFP.VentX after 3 days exposure to DOX. Cells were stained with PI and analyzed by FACS. (F) Effects of VentX on mRNA levels of c-Myc and p21 as determined by real-time PCR. Data represent mean + SD of triplicates from 1 representative experiment. *P < 0.05, **P < 0.01.