Fig. 5: Pentanoate produced by microbiota promotes iron uptake and intestinal Treg differentiation. | Nature Communications

Fig. 5: Pentanoate produced by microbiota promotes iron uptake and intestinal Treg differentiation.

From: Microbiota-assisted iron uptake promotes immune tolerance in the intestine

Fig. 5

a Treg cells in the colon (left) and spleen (right) were isolated from specific pathogen-free mice (SPF), germ-free (GF) and iron-dextran-treated germ-free mice. Labile iron levels were determined by staining with calcein-AM, the fluorescence of which is reversely correlated with levels of intracellular labile iron. Colon, n = 4,4, 3 mice for SPF, GF, GF+iron dextran group, respectively, Spleen, n = 8, 83 mice for SPF, GF, GF+iron dextran, respectively. b, c Germ-free mice were treated with iron dextran and Tregs in the colon were assessed by Foxp3 intracellular staining. PBS-treated germ-free mice and SPF mice were included as controls. b Representative flow cytometry profiles of pregated CD4+CD45+ cells from the colon; (c) Summary of the percentages of Foxp3+ cells in the indicated organs (colon, n = 8,9, 3 mice for SPF, GF, GF+iron dextran group, respectively; S.I., n = 8,8, 4 for SPF, GF, GF+iron dextran group, respectively;spleen, n = 11,11,5 for SPF, GF, GF+iron dextran group, respectively). d Metabolites from the caeca of SPF (mock) and antibiotic-treated SPF (ABX) mice were analyzed by gas chromatography–mass spectrometry (GC–MS). The data are representative of two independent experiments with a total of four mice in each group. e, f SPF mice were treated with pan antibiotics (ABX) and administered with sodium pentanoate via their drinking water for 21 days (ABX+pentanoate). The levels of labile iron, c-Maf and HIF-2α in colonic Tregs were determined by FACS. Untreated SPF mice (mock) and antibiotic-treated SPF mice (ABX) were included as controls. Representative (e) or summarized (f) levels of labile iron (calcein-AM staining), c-Maf and HIF-2α from three independent experiments are shown (Calcein-AM staining, n = 6 mice; c-Maf staining, n = 9 mice; HIF-2α staining, n = 12 mice). g, h The ratios of colonic Treg cells were determined by intracellular staining. g Representative flow cytometric analysis; (h). Summary of four independent experiments (n = 22, 20, 22 micefor SPF, ABX, ABX+pentanoate, respectively). a, c, f, h Statistical significance was determined by a two-tailed t test. *p < 0.05, **p < 0.01,***p < 0.001, ****p < 0.0001. Data shown are mean ± SD.

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