3 research outputs found
A New MAP Kinase Protein Involved in Estradiol-Stimulated Reproduction of the Helminth Parasite Taenia crassiceps
MAP kinases (MAPK) are involved in the regulation of cellular
processes such as reproduction and growth. In parasites, the role
of MAPK has been scarcely studied. Here, we describe the
participation of an ERK-like protein in estrogen-dependent
reproduction of the helminth parasite Taenia
crassiceps. Our results show that 17β-estradiol
induces a concentration-dependent increase in the bud number of in
vitro cultured cysticerci. If parasites are also incubated in
presence of an ERK-inhibitor, the stimulatory effect of estrogen
is blocked. The expression of ERK-like mRNA and its corresponding
protein was detected in the parasite. The ERK-like protein was
over-expressed by all treatments. Nevertheless, a strong induction
of phosphorylation of this protein was observed only in response
to 17β-estradiol. Cross-contamination by host cells was
discarded by flow cytometry analysis. Parasite cells expressing
the ERK-like protein were exclusively located at the subtegument
tissue by confocal microscopy. Finally, the ERK-like protein was
separated by bidimensional electrophoresis and then sequenced,
showing the conserved TEY activation motif, typical of all known
ERK 1/2 proteins. Our results show that an ERK-like protein is
involved in the molecular signalling during the interaction
between the host and T. crassiceps, and may be
considered as target for anti-helminth drugs design
High Estradiol Differentially Affects the Expression of the Glucose Transporter Type 4 in Pelvic Floor Muscles of Rats
Purpose To characterize the relationship between serum estradiol levels and the expression of glucose transporter type 4 (Glut4) in the pubococcygeus and iliococcygeus muscles in female rats. Methods The muscles were excised from virgin rats during the metestrus and proestrus stages of the estrous cycle, and from sham and ovariectomized rats implanted with empty or estradiol benzoate–filled capsules. The expression of estrogen receptors (ERs) was inspected in the muscles at metestrus and proestrus. Relative Glut4 expression, glycogen content, and serum glucose levels were measured. Appropriate statistical tests were done to identify significant differences (P≤0.05). Results The pubococcygeus and iliococcygeus muscles expressed ERα and ERβ. Glut4 expression and glycogen content in the pubococcygeus muscle were higher at proestrus than at metestrus. No significant changes were observed in the iliococcygeus muscle. In ovariectomized rats, the administration of estradiol benzoate increased Glut4 expression and glycogen content in the pubococcygeus muscle alone. Conclusions High serum estradiol levels increased Glut4 expression and glycogen content in the pubococcygeus muscle, but not in the iliococcygeus muscle