Fig. 6: hMSC secrete PGE₂, educates mLN, mesenteric, and peritoneum macrophages to anti-inflammatory phenotype, and suppresses T cells to alleviate small intestine inflammation in SAMP.

Relative gene expression of TNF-α and Arginase I on day 9 of the treatment, measured in the total RNA extracted from CD11b⁺ cells from (a) mesenteric lymph node and (b) mesenteric stromal vascular fraction. c, d Relative gene expression of TNF-α and Arginase I on day 28 of the treatment measured in the total RNA extracted from CD11b⁺ cells from (c) mesenteric lymph node (d) mesenteric stromal vascular fraction. Gene expression was determined by qRT-PCR, normalized to GAPDH, and expressed as fold change (2-ΔΔCt). e Arginase 1/ TNF-α ratio measured by flow cytometry in SAMP peritoneal macrophages. f, g Cell Tracker Red^TM CMPTX dye labelled hMSCs showing in-vivo phagocytosis by CD11b⁺ macrophages in peritoneal lavage (P.L.) and SVF at day 9. h Arginase 1/ TNF-α ratio measured by flow cytometry in SAMP peritoneal and SVF Cd11b⁺ macrophages (Efferocytes) phagocytosed hMSC. i Brightfield microscopic images of SAMP peritoneal macrophages co-cultured with live hMSCs (no visible apoptosis observed) and apoptotic hMSCs (white arrow showing phagosome formation in macrophage), fluorescence image showing phagocytosis of apoptotic hMSCs by SAMP peritoneal macrophages, arrows showing engulfed apoptotic bodies of hMSC. Scale bar 10 µm. j PGE₂ concentration measured in the peritoneal fluid of SAMP. k Absolute numbers of CD3, CD4, and CD8 lymphocytes measured in mLN at day 28 of the treatment. l Relative gene expression of cytokines in CD4 lymphocytes from hMSCs-treated SAMP at day 28. Data were expressed as mean ± SD from at least two independent experiments, each data point represent one mouse. P < 0.05, considered significant, by 2-tailed, unpaired Student’s t test.