Endothelial c-Myc knockout enhances diet-induced liver inflammation and fibrosis

Author(s)

Qi, Yue ^{[1, 2]} ; Qadir, Mirza M. F. ^[3] ; Hastreiter, Araceli A. ^{[4, 2]} ; Fock, Ricardo A. ^{[4, 2]} ; Machi, Jacqueline F. ^{[1, 2]} ; Morales, Alejo A. ^{[1, 2]} ; Wang, Ying ^{[1, 5]} ; Meng, Zhipeng ^{[1, 5]} ; Rodrigues, Claudia O. ^{[1, 2, 5]}

Affiliation

^[1] Univ Miami, Dept Mol & Cellular Pharmacol, Leonard M Miller Sch Med, Miami, FL - USA

^[2] Univ Miami, Interdisciplinary Stem Cell Inst, Leonard M Miller Sch Med, Miami, FL - USA

^[3] Tulane Univ, Sch Med, Sect Endocrinol & Metab, Deming Dept Med, 1430 Tulane Ave, New Orleans, LA 70112 - USA

^[4] Univ Sao Paulo, Sch Pharmaceut Sci, Dept Clin & Toxicol Anal, Sao Paulo - Brazil

^[5] Univ Miami, Sylvester Comprehens Canc Ctr, Leonard M Miller Sch Med, Miami, FL - USA

• Document type: Journal article
• Source: FASEB JOURNAL; v. 36, n. 1 JAN 2022.
• Web of Science Citations: 0

Abstract

Endothelial cells play an essential role in inflammation through synthesis and secretion of chemoattractant cytokines and expression of adhesion molecules required for inflammatory cell attachment and infiltration. The mechanisms by which endothelial cells control the pro-inflammatory response depend on the type of inflammatory stimuli, endothelial cell origin, and tissue involved. In the present study, we investigated the role of the transcription factor c-Myc in inflammation using a conditional knockout mouse model in which Myc is specifically deleted in the endothelium. At a systemic level, circulating monocytes, the chemokine CCL7, and the extracellular-matrix protein osteopontin were significantly increased in endothelial c-Myc knockout (EC-Myc KO) mice, whereas the cytokine TNFSF11 was downregulated. Using an experimental model of steatohepatitis, we investigated the involvement of endothelial c-Myc in diet-induced inflammation. EC-Myc KO animals displayed enhanced pro-inflammatory response, characterized by increased expression of pro-inflammatory cytokines and leukocyte infiltration, and worsened liver fibrosis. Transcriptome analysis identified enhanced expression of genes associated with inflammation, fibrosis, and hepatocellular carcinoma in EC-Myc KO mice relative to control (CT) animals after short-exposure to high-fat diet. Analysis of a single-cell RNA-sequencing dataset of human cirrhotic livers indicated downregulation of MYC in endothelial cells relative to healthy controls. In summary, our results suggest a protective role of endothelial c-Myc in diet-induced liver inflammation and fibrosis. Targeting c-Myc and its downstream pathways in the endothelium may constitute a potential strategy for the treatment of inflammatory disease. (AU)

• FAPESP's process: 17/50022-1 - The role of age-associated endothelial dysfunction in hematopoiesis
• Grantee: Ricardo Ambrósio Fock
• Support Opportunities: Regular Research Grants