Figure 5. PPARD in VGPCs induced CCL20 and CXCL1 secretion to promote chronic gastric inflammation.

(A) Heatmap of secreted chemokines in the culture media of primary organoids derived from gastric corpus crypts from td-PPARD and td-WT mice (Primary), and secondary organoids derived from tdTomato-marked VGPCs, sorted from primary organoid cells by flow cytometry at day 10 or 14 of culture, respectively.

(B, C) Quantitation of secreted CCL20 (C) and CXCL1 (D) protein levels in organoid culture medium described in panel A.

(D, E) CCL20 (D) and CXCL1 (E) mRNA expression levels in digested gastric glands, and primary and secondary organoid cells from mice as described in panel A.

(F) PCR gel image of Helicobacter-specific 16S rRNA amplicons (1.2 kb) for gastric epithelial cells from control and H. felis–infected germ-free C57BL/6J mice.

(G-I) PPARD (G), CCL20 (H), and CXCL1 (I) expression levels of gastric epithelial cells from the mice as described in panel F.

(J-L) Profile characterization of stomach-infiltrating inflammatory immune cells by flow cytometry in gastric tissues of PPARD mice. (J) Immune cells (CD45+), (K) CD3-positive cells (T cells) and B220-positive cells (B cells), and (L, left) CD11b-positive/Gr1-positive cells (granulocytes) and CD11b-positive/Gr1-negative cells (myeloid cells) among CD45-positive living immune cells from PPARD mice as described in panel J. (L, right) Expression of CD11c (dendritic cells) and F4/80 (macrophages) markers on CD45-positive/CD11b-positive/Gr1-negative (myeloid cells). WT mice had extremely low abundance of CD45-positive immune cells in gastric tissues (J).

(M) Pro-inflammatory cytokine mRNA expression levels in gastric corpus tissues from PPARD mice and WT littermates at 25 weeks.