The key steroidogenic enzyme 3β-hydroxysteroid dehydrogenase in Taenia solium and Taenia crassiceps (WFU)

Abstract

Larval and adult stages of Taenia solium and Taenia crassiceps WFU strain were analyzed by histochemical and biochemical methods to determine the existence of steroid pathways. The presence of the key enzyme 3beta-hydroxisteroid-dehydrogenase (3beta-HSD) was examined in frozen sections of cysticerci obtained from mice and segments of tapeworms obtained from the intestine of hamsters. 3beta-HSD activity was detected by nitroblue-tetrazolium products after incubation with dehydroepiandrosterone, androstendiol, or pregnenolone. Tapeworm tissues exhibited 3beta-HSD activity in the subtegumentary areas of the neck and immature proglottids following incubation with androstendiol, as well as surrounding the testes in mature proglottids. T. solium cysticerci exhibited 3beta-HSD activity in the subtegumentary tissues. The synthesis of steroid hormones involving the activity of 3beta-HSD was studied in cysticerci or tapeworms incubated in the presence of tritiated steroid precursors. The culture media were analyzed by thin layer chromatography and showed synthesis of androstendiol, testosterone, and 17beta-estradiol by cysticerci, androstendiol, and 17beta-estradiol by tapeworms. The results strongly suggest the activity of 3beta-HSD in taeniid parasites that have at least a part of the enzymatic chain required for androgen and estrogen synthesis and that the enzymes are present in the larval stage and from the early strobilar stages to the mature proglottids.

The effect of glucocorticoids on sex steroid synthesis in cultured Taenia crassiceps Wake Forest University (WFU) cysticerci

“…Present data confirm our previous results that showed the ability of T. crassiceps WFU infrapopulations to transform [ 3 H]DHEA to androgens, such as testosterone and androstenediol, and the oestrogen 17b-oestradiol Valdéz et al, 2006;Fernández Presas et al, 2008). Results shown here indicate that cysticerci that have proliferated for several months in the abdominal cavity of mice, maintain their steroidogenic capacity.…”

Steroidogenic capacity of Trypanosoma cruzi trypomastigotes

“…We have also demonstrated that T. solium cysticerci synthesized androgens and small quantities of estrogens in vitro [34]. Recent results from our laboratory also showed that T. solium and T. crassiceps cysticerci as well as the adult worms synthesized steroid hormones from tritiated progesterone and dehydroepiandrosterone [35,43]. These results strongly suggest the presence and activity of steroidogenic enzymes in cysticerci.…”

“…To this regards, our group has recently reported the transformation of DHEA to androgens in Taenia solium and Taenia crassiceps cysticerci [35]. Furthermore, a recent paper from our group has demonstrated the presence and activity of 3␤-hydroxysteroid dehydrogenase/delta 5-4 in T. crassiceps WFU and T. solium adult worms and cysticerci [43]. Interestingly, immunoreactivity for 3␤-hydroxysteroid dehydrogenase/delta 5-4 has been shown in the cytoplasm of the parasite Sarcocystis spp.…”

Excretory/Secretory-Products of Echinococcus multilocularis Larvae Induce Apoptosis and Tolerogenic Properties in Dendritic Cells In Vitro

“…However, the presence of a respective receptor in these organisms implies that they might also express cognate ligands, which subsequently could bind to members of the TNF-receptor family on host cells (such as DC), thus triggering apoptosis. Apart from components of the TNF signaling machinery, it has recently also been demonstrated that cestode larvae ( T. crassiceps cysticerci) are capable of producing steroid hormones [57]. Although in this system only the production of sex steroids has been tested, it is conceivable that they also produce glucocorticoids which might, either together with TNF-ligands or as an alternative, be involved in triggering host DC apoptosis.…”