Fig 2: IL-37 inhibited the expression of GSK3 in placental tissues. Immunohistochemical staining of GSK3 in placental tissues. 400 ×, scale bar: 50 μm. N = 6, ###p < 0.001, relative to control group; **p < 0.01; ***p < 0.001, relative to GDM group

Fig 3: IL-37 inhibited the inflammatory response in GDM mice (A) Placental weights; (B) The histopathological changes were detected by HE staining in the placenta. 200 ×, scale bar: 100 μm; (C) Immunohistochemical staining of CCL2 in placental tissues. The positive percentage of CCL2 was analyzed using Image J software. 400 ×, scale bar: 50 μm; (D) RT-qPCR were used to determine the expression of the mRNA levels of TNF-α, IL-6, IL-1β, and IL-17 A in placental tissues. N = 6, #p < 0.05, ##p < 0.01, ###p < 0.001, relative to control group; *p < 0.05; **p < 0.01; ***p < 0.001, relative to GDM group

Fig 4: IL-37 ameliorated abnormal glucose metabolism and insulin resistance by inhibiting the GSK3/NF-κB pathway. (A) GTT and AUC values; (B) ITT and AUC values; (C) Fasting blood glucose, fasting insulin, and the HOMA-IR index; (D) Assess the expression of GLUT4 and IRS-1 in the placenta using western blot. N = 6, #p < 0.05, ##p < 0.01, ###p < 0.001, relative to GDM group; *p < 0.05, ***p < 0.001, relative to GDM + IL-37 group

Fig 5: IL-37 influenced glucose tolerance and insulin sensitivity in GDM mice (A) Schematic diagram of the GDM mouse modeling and treatment scheme (B) GTT and AUC values (C) ITT and AUC values (D) Fasting blood glucose, fasting insulin, and the HOMA-IR index (E) Western blot analysis was conducted to assess the expression of GLUT3, GLUT4, IRS-1 and IRS-2 in the placenta. N = 6, ##p < 0.01, ###p < 0.001, relative to control group; *p < 0.05; **p < 0.01; ***p < 0.001, relative to GDM group