Fig. 4

Lower progesterone receptor expression and increased expression of BCL2 family genes in Adgra3^−/− females with a closed vagina. a Illustration of the upregulation of progesterone receptor (Pgr) by estrogen receptor α (ERα) following estrogen stimulation in vaginal epithelial cells [52, 53]. b Progesterone levels measured in blood plasma harvested from 8- to 10-week-old Adgra3^+/+ (n = 5), Adgra3^−/− (n = 4), and Adgra3^−/−CV (n = 3) mice in proestrus. Limit of detection (LOD) = 0.036 nmol/L. c, d mRNA expression of progesterone receptor (Pgr) in c vagina and d ovary of 8- to 10-week-old Adgra3^−/− (n = 4) and Adgra3^−/−CV (n = 3–4) mice relative to Adgra3^+/+ (n = 6). ****p < 0.0001, ***p = 0.0002. e Illustration of the intrinsic apoptotic pathway regulated by the BCL2 family. Extracellular apoptotic stimuli activate sensitizer proteins, including BID, BIM, PUMA, and BMF. The sensitizers either inhibit the group of apoptotic protector proteins (e.g., BCL2) or activate apoptotic executors (e.g., BAX and BAK1). Activating apoptotic executor proteins leads to the release of cytochrome c from the mitochondria and subsequent apoptosis [54]. f–h mRNA expression of BCL2 family genes fBcl2, gBid, and hBmf in vaginal tissue from 8- to 10-week-old Adgra3^−/− (n = 4) and Adgra3^−/−CV (n = 3) mice relative to Adgra3^+/+ (n = 7) mice. Relative expression was calculated using housekeeping genes 36b4 and Ywhaz and the 2^−∆∆CT method. ***p = 0.0009 (f), ***p = 0.0003 (g), p = 0.0129 (h). Each dot represents an individual animal. Data are presented as mean ± SEM. Significance was calculated using one-way ANOVA post hoc Dunnett’s multiple comparisons test