Fig 2: IL-13RA2 was downregulated in KFs and negatively correlated with p-STAT6.(A) The mRNA levels of IL13RA2, IL13RA1, and IL4R in normal skin dermis and keloids (n = 3 and 5, respectively). (B) The protein level of IL-13RA2 in normal skin dermis (NSD) and keloid dermis (KD). Quantification of gray scale of IL-13RA2/GAPDH is shown below. (C) Representative images of IL-13RA2 expression by IHC staining in normal skins and keloids. Scale bar: 50 μm. IHC scores of IL-13RA2 in normal skin (n = 6) and keloids (n = 11) is shown on right. (D) The mRNA level of IL13RA2 in NFs and KFs (n = 3 and 5, respectively). (E) The protein level of IL-13RA2 in NFs (n = 3) and KFs (n = 4). (F) The negative correlation between IL-13RA2 and p-STAT6. Pearson’s correlation analysis of relative gray values is shown. Error bars represent SD. Experiments were performed 3 times. *P < 0.05; ***P < 0.001 by 2-tailed Student’s t test.

Fig 3: Overexpression of IL-13RA2 induced KF apoptosis.(A) Growth curves of KFs upon IL-13RA2 overexpression. (B) Annexin V/7-AAD double staining assay of KF-vector and KF-IL13RA2 cells (n = 5). Quantification of Annexin V–positive rates, representing apoptotic rates, is shown below. (C and D) Expression of p-STAT6, BCL2L1, and BCL2 in KFs upon IL-13RA2 overexpression. Quantifications of relative gray scale is shown below the blots. (E and F) IC50 values of AS1517499 in KF-vector and KF-IL13RA2 cells. *P < 0.05; **P < 0.01; ***P < 0.001 by paired, 2-tailed Student’s t test.

Fig 4: Overexpression of IL-13RA2 alleviated KF IL-13–related profibrotic cell behavior.(A) Annexin V/7-AAD double staining assay of KFs with or without IL-13 stimulation. (B) Quantification of Annexin V–positive rates, representing apoptotic rates. (C) Expression of p-STAT6, BCL2L1, and BCL2 in 20KF-vector and 20KF-IL13RA2 cells with or without IL-13 stimulation. (D and E) Migration and invasion of KF-vector and KF-IL13RA2 cells. Scale bar: 50 μm. Quantification of migrated and invaded cells is shown in E. (F and G) Expression of MMPs, COL3A1 and COL1A1, and mesenchymal markers FN1 and vimentin in KF-vector and KF-IL13RA2 cells. (H) Expression of α-SMA in KF-vector and KF-IL13RA2 cells. (I) Representative images of α-SMA immunofluorescent staining in KF-vector and KF-IL13RA2 cells. Scale bars: 100 μm. Error bars represent SD. Experiments were performed 3 times and at least in triplicate each time. **P < 0.01; ***P < 0.001; ****P < 0.0001 by 2-tailed Student’s t test.

Fig 5: Co-staining of IL13Ra2 with H3.3-K27M, Ki67, and CD133. Images showing co-expression of IL13Ra2 and H3K27M (A), Ki67 (B), and CD133 (C) in BSG tumor tissues. The linear regression results between IL13Ra2 expression and H3K27M (D), Ki67 (E), and CD133 (F) expression in BSG tumor tissue. Comparison of the positive rates of H3K27M (G), Ki67 (H), and CD133 (I) in IL13Ra2-positive and negative cells from different tumor samples. Comparison of the positive rates of IL13Ra2 in H3K27M-positive/H3K27M-negative (J), Ki67-positive/Ki67-negative (K), and CD133-positive/CD133-negative (L) tumor cells across different tumor tissues (**** p < 0.0001).