MafB, a transcription factor, plays a crucial role in regulating macrophage differentiation. It is involved in various biological processes and diseases related to macrophages. In the mononuclear phagocyte system, MafB controls the transition from monocyte proliferation to the specification of lung interstitial macrophage subsets [3].

Studies using macrophage-specific Mafb-deficient (Mafbf/f::LysM-Cre) mice show that MafB deficiency in macrophages reduces thermogenesis, energy expenditure, and sympathetic neuron density in brown adipose tissue under cold conditions, due to a pro-inflammatory environment [2]. In addition, MafB-deficient macrophages have been linked to diseases like atherosclerosis, autoimmunity, obesity, and ischemic stroke, all of which exhibit macrophage abnormality [1]. In esophageal squamous cell carcinomas, knockdown of MAFB significantly suppresses cell growth, migration, and invasion, suggesting it may play a tumor-promoting role [4]. In macrophages, MafB knockdown or knockout enhances NLRP3 inflammasome activation, and myeloid MafB-deficient mice show increased systemic and lung IL-1β production in response to certain infections [5].

In conclusion, MafB is essential for macrophage-related functions, as demonstrated through gene-knockout mouse models. These models have revealed its roles in various disease conditions such as those related to macrophage-mediated inflammation, thermogenesis, and cancer, providing insights into potential therapeutic targets.

References:

1. Hamada, Michito, Tsunakawa, Yuki, Jeon, Hyojung, Yadav, Manoj Kumar, Takahashi, Satoru. 2019. Role of MafB in macrophages. In Experimental animals, 69, 1-10. doi:10.1538/expanim.19-0076. https://pubmed.ncbi.nlm.nih.gov/31582643/

2. Yadav, Manoj Kumar, Ishida, Megumi, Gogoleva, Natalia, Takahashi, Satoru, Hamada, Michito. 2024. MAFB in macrophages regulates cold-induced neuronal density in brown adipose tissue. In Cell reports, 43, 113978. doi:10.1016/j.celrep.2024.113978. https://pubmed.ncbi.nlm.nih.gov/38522069/

3. Vanneste, Domien, Bai, Qiang, Hasan, Shakir, Bureau, Fabrice, Marichal, Thomas. 2023. MafB-restricted local monocyte proliferation precedes lung interstitial macrophage differentiation. In Nature immunology, 24, 827-840. doi:10.1038/s41590-023-01468-3. https://pubmed.ncbi.nlm.nih.gov/36928411/

4. Zhang, Shaobo, Gong, Tongyang, Nan, Yabin, Liu, Zhihua, Chen, Hongyan. 2022. MAFB promotes the malignant phenotypes by IGFBP6 in esophageal squamous cell carcinomas. In Experimental cell research, 416, 113158. doi:10.1016/j.yexcr.2022.113158. https://pubmed.ncbi.nlm.nih.gov/35430273/

5. Cui, Huachun, Banerjee, Sami, Xie, Na, Sanders, Yan Y, Liu, Gang. 2023. MafB regulates NLRP3 inflammasome activation by sustaining p62 expression in macrophages. In Communications biology, 6, 1047. doi:10.1038/s42003-023-05426-5. https://pubmed.ncbi.nlm.nih.gov/37845329/