Figure 4.

CD164 plays an important role in the apoptosis of spermatogonia. A) High‐frequency genes downregulated in spermatogonial stem cells (SSC) of four classes idiopathic nonobstructive azoospermia (iNOA). B) The expression levels of CD164 in human spermatogenesis. The two‐tailed Mann–Whitney–Wilcoxon test was used to assess significance. C) Immunostaining of CD164, LIN28A (a marker for undifferentiated spermatogonia), and SOHLH2 (a marker for differentiated spermatogonia) in testis sections from human adults. The DNA was stained with DAPI. Scale bar = 20 µm. Immunostaining of CD164, Lin28A (a marker for undifferentiated spermatogonia) and C‐Kit (a marker for differentiated spermatogonial) in testis sections from wild type mice at the indicated times. The DNA was stained with DAPI. Scale bar = 50 µm. D) Cd164 mRNA levels in GC1 cells infected with either two independent Cd164 siRNA or a scrambled siRNA (Ctrl siRNA). The results are normalized to the Gapdh mRNA level. n = 3, Error bars, S.D. ^*p < 0.05, ^**p < 0.01 by two‐tailed Student's t test. E) GC1 cells stained with Annexin V‐FITC/PI were analyzed by flow cytometry, Q1: dead cells (FITC⁻/PI⁺), Q2: late apoptosis (FITC⁺/PI⁺), Q3: viable cells (FITC⁻/PI⁻), Q4: early apoptosis (FITC⁺/PI⁻). Histogram of the total apoptotic rate in different groups. The total apoptosis rate was defined as late apoptosis plus early apoptosis. n = 3, Error bars, S.D. ^* p < 0.05 by two‐tailed Student's t test. F) Gene expression patterns of molecules in the apoptosis signaling pathway and the possible mechanism by which CD164 promotes spermatogonia apoptosis. The two‐tailed Student's t test was used to assess significance.