Transcriptomics Analysis Reveals New Insights into the Roles of Notch1 Signaling on Macrophage Polarization

• Published in: Scientific reports 2019-05, Vol.9 (1), p.7999, Article 7999
• Main Authors: Hans, Chetan P., Sharma, Neekun, Sen, Sidharth, Zeng, Shuai, Dev, Rishabh, Jiang, Yuexu, Mahajan, Advitiya, Joshi, Trupti
• Format: Article
• Language: English
• Subjects: 13/21; 14/1; 38/90; 38/91; 631/250/127; 631/250/127/1213; 64/60; Aneurysms; Animals; Aortic Aneurysm, Abdominal - genetics; Aortic Aneurysm, Abdominal - metabolism; Aortic Aneurysm, Abdominal - pathology; Bioinformatics; Bone marrow; Caspase; Caspase-4; Cell Differentiation - drug effects; Cell Polarity - genetics; Collagen (type I); Computational Biology; Disease Models, Animal; Extracellular matrix; Fibromodulin - genetics; Gene Expression Regulation, Developmental - drug effects; Haploinsufficiency; Humanities and Social Sciences; Humans; Insulin-like growth factors; Interferon-gamma - pharmacology; Interleukin 1; Interleukin 13; Interleukin 4; Interleukin-13 - pharmacology; Interleukin-4 - pharmacology; Lipopolysaccharides - pharmacology; Macrophage Activation - genetics; Macrophages; Macrophages - metabolism; Macrophages - pathology; Mice; multidisciplinary; Notch1 protein; Osteogenesis; Phenotypes; Polarization; Receptor, Notch1 - genetics; Ribonucleic acid; RNA; Science; Science (multidisciplinary); Signal transduction; Signal Transduction - drug effects; Transcriptome - genetics; γ-Interferon
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-019-44266-4

Naïve macrophages (Mφ) polarize in response to various environmental cues to a spectrum of cells that have distinct biological functions. The extreme ends of the spectrum are classified as M1 and M2 macrophages. Previously, we demonstrated that Notch1 deficiency promotes Tgf-β2 dependent M2-polarization in a mouse model of abdominal aortic aneurysm. The present studies aimed to characterize the unique set of genes regulated by Notch1 signaling in macrophage polarization. Bone marrow derived macrophages isolated from WT or Notch1 +/− mice (n = 12) were differentiated to Mφ, M1 or M2-phenotypes by 24 h exposure to vehicle, LPS/IFN-γ or IL4/IL13 respectively and total RNA was subjected to RNA-Sequencing (n = 3). Bioinformatics analyses demonstrated that Notch1 haploinsufficiency downregulated the expression of 262 genes at baseline level, 307 genes with LPS/IFN-γ and 254 genes with IL4/IL13 treatment. Among these, the most unique genes downregulated by Notch1 haploinsufficiency included fibromodulin ( Fmod ), caspase-4 , Has1 , Col1a1 , Alpl and Igf . Pathway analysis demonstrated that extracellular matrix, macrophage polarization and osteogenesis were the major pathways affected by Notch1 haploinsufficiency. Gain and loss-of-function studies established a strong correlation between Notch1 haploinsufficiency and Fmod in regulating Tgf-β signaling. Collectively, our studies suggest that Notch1 haploinsufficiency increases M2 polarization through these newly identified genes.