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 6

VentX transactivates M-CSFR expression.

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VentX transactivates M-CSFR expression. (A–C) U937 cell lines expressing...
(A–C) U937 cell lines expressing GFP or GFP.VentX under the control of tetracycline-inducible promoter were treated with 1.0 μg/ml DOX for 72 hours. (A) Western blot analysis of M-CSFR protein levels from U937 cell lysates. Tubulin was used as a loading control. (B) Surface expression of M-CSFR was determined by FACS analysis. Filled gray histogram represents isotype control; solid line histogram represents cells expressing GFP; dotted line histogram represents cells expressing GFP.VentX. (C) M-CSFR mRNA levels were determined by real-time PCR. Data represent mean + SD of triplicates from 1 representative experiment. (D) VentX transactivation of M-CSFR promoter. pcDNA-VentX or pcDNA-control was cotransfected with wild-type or mutant M-CSFR promoter luciferase reporter constructs into U937 cells. The effect of VentX on M-CSFR promoter transactivation was determined by luciferase activity. Data are mean + SD of triplicates from 1 representative experiment. (E) ChIP analysis of the interaction between VentX and the M-CSFR promoter, showing the association of VentX with the M-CSFR promoter region but not with the Cμ region in U937 cells. (F) Gel shift analysis showing the binding of VentX to the wild-type M-CSFR promoter probe, but reduced binding to the mutant M-CSFR promoter (Mut) probe. *P < 0.05, **P < 0.01.