Figure 2
The transporter Mrp4 protects Leydig cells from 6 MP death.
Immunohistochemical Leydig cell staining of (a) 3βHsd1 and (b) Mrp4 in WT (left) and KO (right) mice (magnification ×20). (c) Percent of caspase 3 positive Leydig cells of 6 MP treated mice. (d) WT (left) and KO (right) 6 MP treated mice showing Leydig cells stained with caspase 3. Dark lines indicate interstitial areas that harbor Leydig cells, between seminiferous tubules. Arrows indicate Leydig cells positively stained for caspase 3 (magnification ×20). (e) Control (top) and 6 MP (bottom) treated mice. Dark lines indicate interstitial areas between seminiferous tubules. Enlarged insets show cells in the interstitium. (f) Quantitation of void areas represented in (f) Serum testosterone concentration of 6 MP treated mice (n = 6 mice). Intracellular accumulation of radiolabelled 6 MP in Leydig cells when comparing WT to (h) KO cells or (i) WT cells treated with pharmacologic Mrp4 inhibitor, MK571. (j) Mrp4 expression in isolated Leydig cells as analyzed by immunoblot (top) and normalized by actin (bottom). The graph on the right shows band quantitation by ImageJ. (k) Viability of Mrp4 wildtype (WT), heterozygote (HET) and knockout (KO) Leydig cells treated with 6 MP. All error bars are mean ± SEM. *p ≤ 0.05.
