G9a Modulates Lipid Metabolism in CD4 T Cells to Regulate Intestinal Inflammation. Gastroenterology 2023 Feb;164(2):256-271.e10
Date
10/23/2022Pubmed ID
36272457Pubmed Central ID
PMC9892272DOI
10.1053/j.gastro.2022.10.011Scopus ID
2-s2.0-85146286897 (requires institutional sign-in at Scopus site) 4 CitationsAbstract
BACKGROUND & AIMS: Although T-cell intrinsic expression of G9a has been associated with murine intestinal inflammation, mechanistic insight into the role of this methyltransferase in human T-cell differentiation is ill defined, and manipulation of G9a function for therapeutic use against inflammatory disorders is unexplored.
METHODS: Human naive T cells were isolated from peripheral blood and differentiated in vitro in the presence of a G9a inhibitor (UNC0642) before being characterized via the transcriptome (RNA sequencing), chromatin accessibility (assay for transposase-accessible chromatin by sequencing), protein expression (cytometry by time of flight, flow cytometry), metabolism (mitochondrial stress test, ultrahigh performance liquid chromatography-tandem mas spectroscopy) and function (T-cell suppression assay). The in vivo role of G9a was assessed using 3 murine models.
RESULTS: We discovered that pharmacologic inhibition of G9a enzymatic function in human CD4 T cells led to spontaneous generation of FOXP3+ T cells (G9a-inibitors-T regulatory cells [Tregs]) in vitro that faithfully reproduce human Tregs, functionally and phenotypically. Mechanistically, G9a inhibition altered the transcriptional regulation of genes involved in lipid biosynthesis in T cells, resulting in increased intracellular cholesterol. Metabolomic profiling of G9a-inibitors-Tregs confirmed elevated lipid pathways that support Treg development through oxidative phosphorylation and enhanced lipid membrane composition. Pharmacologic G9a inhibition promoted Treg expansion in vivo upon antigen (gliadin) stimulation and ameliorated acute trinitrobenzene sulfonic acid-induced colitis secondary to tissue-specific Treg development. Finally, Tregs lacking G9a expression (G9a-knockout Tregs) remain functional chronically and can rescue T-cell transfer-induced colitis.
CONCLUSION: G9a inhibition promotes cholesterol metabolism in T cells, favoring a metabolic profile that facilitates Treg development in vitro and in vivo. Our data support the potential use of G9a inhibitors in the treatment of immune-mediated conditions including inflammatory bowel disease.
Author List
Ramos GP, Bamidele AO, Klatt EE, Sagstetter MR, Kurdi AT, Hamdan FH, Kosinsky RL, Gaballa JM, Nair A, Sun Z, Dasari S, Lanza IR, Rozeveld CN, Schott MB, Urrutia G, Westphal MS, Clarkson BD, Howe CL, Marietta EV, Luckey DH, Murray JA, Gonzalez M, Braga Neto MB, Gibbons HR, Smyrk TC, Johnsen S, Lomberk G, Faubion WAAuthor
Gwen Lomberk PhD Professor in the Surgery department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsCD4-Positive T-Lymphocytes
Cholesterol
Chromatin
Colitis
Forkhead Transcription Factors
Humans
Inflammation
Lipid Metabolism
Lipids
Mice
T-Lymphocytes, Regulatory
