Antiandrogen exposure in utero disrupts expression of desert hedgehog and insulin-like factor 3 in the developing fetal rat testis.
Testicular development is an androgen-dependent process, and fetal exposure to antiandrogens disrupts male sexual differentiation. A variety of testicular disorders may result from impaired development of fetal Leydig and Sertoli cells. We hypothesized that antiandrogenic exposure during fetal development interferes with desert hedgehog (Dhh) signaling in the testis and results in impaired Leydig cell differentiation. Fetal rats were exposed in utero to the antiandrogen flutamide from 10.5 d post conception (dpc) until they were killed or delivery. Fetal testes were isolated at different time points during gestation and gene expression levels of Dhh, patched-1 (Ptc1), steroidogenic factor 1 (Sf1), cytochrome P450 side-chain cleavage (P450scc), 3beta-hydroxysteroid dehydrogenase type 1 (Hsd3b1), and insulin-like factor 3 (Insl3) were analyzed. To study direct effects of hedgehog signaling on testicular development, testes from 14.5 dpc fetuses were cultured for 3 d in the presence of cyclopamine, sonic hedgehog, or vehicle, and gene expression levels and testosterone secretion were analyzed. Organ cultures were also analyzed histologically, and cleaved-caspase 3 immunohistochemistry was performed to assess apoptosis. In utero exposure to flutamide decreased expression levels of Dhh, Ptc1, Sf1, P450scc, Hsd3b1, and Insl3, particularly from 17.5 dpc onward. Inhibition of hedgehog signaling in testis cultures resulted in similar effects on gene expression levels. Apoptosis in Wolffian ducts was increased by cyclopamine compared with sonic hedgehog- or vehicle-treated cultures. We conclude that exposure to the antiandrogen flutamide interferes with Dhh signaling resulting in an impaired differentiation of the fetal Leydig cells and subsequently leading to abnormal testicular development and sexual differentiation.
Brokken
Leon J S
LJ
Department of Physiology, University of Turku, Kiinamyllynkatu 10, 20520 Turku, Finland.
Adamsson
Annika
A
Paranko
Jorma
J
Toppari
Jorma
J
D000726:Androgen Antagonists / Q000494:pharmacology*; D000818:Animals; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000235:genetics; D017931:DNA Primers; D005260:Female; D047109:Fetal Development / Q000187:drug effects*; D005485:Flutamide / Q000494:pharmacology*; D053823:Hedgehog Proteins / Q000235:genetics*; D007328:Insulin / Q000235:genetics*; D007986:Luteinizing Hormone / Q000378:metabolism; D008297:Male; D009924:Organ Culture Techniques; D000072079:Patched Receptors; D000072081:Patched-1 Receptor; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011374:Progesterone / Q000378:metabolism; D011506:Proteins / Q000235:genetics*; D051381:Rats; D011944:Receptors, Androgen / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics; D013737:Testis / Q000196:embryology*; D013739:Testosterone / Q000378:metabolism
D000726:Androgen Antagonists; D017931:DNA Primers; D053823:Hedgehog Proteins; D007328:Insulin; C084797:Leydig insulin-like protein; D000072079:Patched Receptors; D000072081:Patched-1 Receptor; D011506:Proteins; C000606239:Ptch1 protein, rat; D011944:Receptors, Androgen; D011956:Receptors, Cell Surface; D013739:Testosterone; D011374:Progesterone; D005485:Flutamide; D007986:Luteinizing Hormone; D002786:Cholesterol Side-Chain Cleavage Enzyme