ABSTRACT
<p><b>OBJECTIVE</b>To study the role of extracellular signal-regulated protein kinase 5 (ERK5) during the biosynthesis of follicle-stimulating hormone (FSH)-mediated progesterone in primary granulosa cells.</p><p><b>METHODS</b>The expressions of phosphorylated and general forms of ERKS in primary granulosa cells after the treatment of FSH were detected by Western blot analysis. The subcellular localization of ERK5 was observed by confocal microscopy. The effect of ERK5 on FSH-mediated progesterone biosynthesis in primary granulosa cells was analyzed using recombinant adenovirus vectors.</p><p><b>RESULTS</b>ERK5 activation was induced by FSH in a time-dependent manner in primary cultured granulosa cells, although the general ERK5 protein level decreased also in a time-dependent manner. The treatment of FSH showed no remarkable effect on the subcellular distribution of endogenous ERK5, which was mainly in the cytoplasm of granulosa cells. The co-infection of Ad-caMEK5 and Ad-wtERK5 increased the progesterone production and StAR expression in primary cultured granulosa cells, whereas inhibition of ERK5 activation suppressed the FSH-stimulated progesterone production.</p><p><b>CONCLUSION</b>ERK5 may stimulate FSH-mediated progesterone production in primary cultured granulosa cells.</p>
Subject(s)
Animals , Female , Rats , Cells, Cultured , Follicle Stimulating Hormone , Pharmacology , Granulosa Cells , Metabolism , Mitogen-Activated Protein Kinase 7 , Metabolism , Physiology , Progesterone , Rats, Sprague-DawleyABSTRACT
<p><b>OBJECTIVE</b>To investigate the change of free Ca(2+) in cytoplasma in the neurotoxicity of the manganese (Mn).</p><p><b>METHODS</b>The cortical neurons were separated from the neonatal Wistar rats and cultured in vitro. The neurons were grouped as the Mn-treated groups and the untreated group. The neurons in the Mn-added groups were incubated in the culture media containing lower, medium and high dosage manganese chloride (MnCl(2 x 4) H2O) with the concentration at 0.2, 0.6, 1.0 mmol/L respectively. Meanwhile, neurons in control were cultured in the normal culture media. All treatments stopped 24 h later. Neurons were labeled Ca(2+) sensitive prober, Fluo-3/AM. The fluorescence intensity of Fluo-3 combined with Ca(2+) was examined by LSCM (Laser scanning confocal microscope) and was treated by the picture analysis technique. The intensity was equal to the free Ca(2+) concentrations in cytoplasma of neurons.</p><p><b>RESULTS</b>MnCl(2) can induce free Ca(2+) overloaded in cytoplasma of neurons, but the increasing degree varied in MnCl(2) dosage. Cytoplasma Ca(2+) concentration in the moderate dosage The moderate dosage MnCl(2) group and the high dosage MnCl(2) group were significantly higher than that in the lower dosage MnCl(2) group and the control group (P < 0.05).</p><p><b>CONCLUSION</b>The Ca(2+) overload is involved in the neurotoxicity of manganese, and a dosage response relationship is found between the manganese chloride dose and Ca(2+) overload in cortical neurons.</p>