Research Paper Volume 12, Issue 7 pp 6089—6108

Figure 3. The estradiol metabolites 2-OHE₂ and 4-OHE₂ are closely associated with astrocyte senescence. (A) The flow chart of estradiol metabolism. (B) HPLC chromatogram of 2-OHE₂ and 4-OHE₂ in hypothalamic tissue of 10-month-old mice. (C) Dual-label immunofluorescence showing astrocytes (green) and p16 (red) with 2-OHE₂ and 4-OHE₂, white arrows representing γH2AX–positive astrocytes (left). Dual-label immunofluorescence showing astrocytes (green) and γ-H2AX (red) with 2-OHE₂ and 4-OHE₂, white arrows representing γ-H2AX–positive astrocytes (right). Scale bar= 100 μm. (D) Detection of p16 and p21 mRNA levels with 2-OHE₂ and 4-OHE₂ intervention. 2-OHE₂ and 4-OHE₂ respectively increased the expression of p16 and p21 in hypothalamic astrocytes (n=3). The p-value was determined by One-way ANOVA: ** p< 0.01.