SP27 Miz-1 inflamed

SP27 The 'Myc interacting zinc finger protein 1' (Miz-1) regulates signalling pathways that mediate inflammatory response

Project leader: Christian Kosan

Background and previous work
Inflammation is an immediate response of the body to tissue damage and foreign pathogens like bacteria. Key pro-inflammatory cytokines are TNF-α, IL-6 and IL-1β and massive release promotes systemic inflammation. TNF-α activates several signalling pathways and key effectors, including NF-κB, p38 and JNK (c-Jun N-terminal kinase). A recent publication showed that the transcription factor 'Myc interacting zinc finger protein 1' (Miz-1) inhibits pro-inflammatory cytokine production by directly repression the Cebpd gene (C/EBP-δ) via histone deacetylase 1 (HDAC1) recruitment in acute lung inflammation. Furthermore, Miz-1 interacts with JNK and blocks JNK activity. We have shown that bone marrow-derived macrophages from Miz-1-deficient mice had an elevated expression of pro-inflammatory cytokines upon LPS treatment (unpublished) These findings make it tempting to speculate about a key role of Miz-1 in the adaptive inflammatory stress response, in particular, the role of Miz-1 in inflammatory stress persistance.

Specific aims and working programme
We will analyze the response to low- and high-dose inflammatory stimulation in wild type and Miz-1-deficient mice. We will determine the role of Miz-1 in the termination of the inflammatory response. Aim 1: We will inject wild type and Miz-1-deficient mice intraperitoneally (i.p.) with low dose LPS (0.5 mg/kg) and determine pro-inflammatory cytokines (TNF-α, IL-6 and IL 1β) by ELISA from peripheral blood. Furthermore, we will perform a booster injection with 5 mg/kg LPS. Pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β) will be measured by ELISA and overall survival rates will be determined. Aim 2: Bone marrow-derived macrophages (BMDM) will be generated from wild type and Miz-1-deficient mice and stimulated with different concentrations of LPS and TNF-α. We will determine the level of pro-inflammatory cytokine (TNF-α, IL-6 and IL-1β) transcription by qRT-PCR and release by ELISA. Aim 3: We will perform RNA Sequencing (RNA-Seq) experiments to identify differently expressed genes from wild type and Miz-1 deficient BMDMs stimulated with LPS and TNF-α. Additionally, we will use chromatin-immunoprecipitation (ChIP) in the human monocyte cell line THP-1 to analyze DNA-binding sites of Miz-1 and NF-κB after LPS and TNF-α stimulation.