Effect of phospholipids on the reconstitution and thermal stability of delipidated rat ovarian luteinizing hormone/human chorionic gonadotropin receptors in proteoliposomes

Kolena, J; Scsuková, Soňa; Ježová, M; Furdová, J.; Tatara, M; P, Jasem

doi:10.1016/0303-7207(95)03610-j

Cited by 5 publications

(7 citation statements)

References 16 publications

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“…Xiao et al (2011) investigating the cellular uptake mechanisms of PEG-b-PLA micelles demonstrated that they fi rstly interacted with cell membrane, induced cell membrane depolarization and enhance membrane microviscosity in a dosedependent manner. Previously, we have reported that cell membrane microenvironment plays an essential role in regulation of structure-function relationship of gonadotropin receptors (Kolena et al 1995). Th e obtained results might indicate that understanding of interaction of NPs with cell membranes and their internalization into the cells is important in determining their diverse biological responses.…”

Section: Discussionmentioning

confidence: 89%

Adverse eff ects of polymeric nanoparticle poly(ethylene glycol)- block-polylactide methyl ether (PEG-b-PLA) on steroid hormone secretion by porcine granulosa cells

Scsuková

Bujnakova

Kiss

et al. 2017

Endocrine Regulations

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Objectives. Development of nanoparticles (NPs) for biomedical applications, including medical imaging and drug delivery, is currently undergoing a dramatic expansion. Diverse eff ects of diff erent type NPs relating to mammalian reproductive tissues have been demonstrated. Th e objective of this study was to explore the in vitro eff ects of polymeric nanoparticle poly(ethylene glycol)-blockpolylactide methyl ether (PEG-b-PLA NPs) on functional state and viability of ovarian granulosa cells (GCs), which play an important role in maintaining ovarian function and female fertility.Methods. Th e GCs isolated from porcine ovarian follicles were incubated with the diff erent concentrations of PEG-b-PLA NPs (PEG average Mn=350 g/mol and PLA average Mn=1000 g/mol; 0.2-100 μg/ml) or poly(ethylene glycol) with an average molecular weight of 300 (PEG-300; 0.2-40 mg/ml) in the presence or absence of stimulators, follicle-stimulating hormone (FSH; 1 μg/ml), androstenedione (100 nM), forskolin (10 μM) or 8Br-cAMP (100 μM), for diff erent time periods (24, 48, 72 h). At the end of the incubation, progesterone and estradiol levels produced by GCs were measured in the culture media by radioimmunoassay. Th e viability of GCs was determined by the method using a colorimetric assay with MTT.Results. Treatment of GCs with PEG-b-PLA NPs induced a signifi cant decrease in basal as well as FSH-stimulated progesterone secretion above the concentration of 20 and 4 μg/ml, respectively. Moreover, PEG-b-PLA NPs reduced forskolin-stimulated, but not cAMP-stimulated progesterone production by GCs. A dose-dependent inhibition of androstenedione-stimulated estradiol release by GCs was found by the action of PEG-b-PLA NPs. Incubation of GCs with PEG-300 significantly inhibited basal as well as FSH-stimulated progesterone secretion above the concentration of 40 mg/ml. PEG-b-PLA NPs and PEG-300 signifi cantly reduced the viability of GCs at the highest tested concentrations (100 μg/ml and 40 mg/ml, respectively).Conclusions. Th e obtained results indicate that polymeric NPs PEG-b-PLA might induce alterations in steroid hormone production by ovarian GCs and thereby could modify reproductive functions.

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Section: Discussionmentioning

confidence: 89%

Adverse eff ects of polymeric nanoparticle poly(ethylene glycol)- block-polylactide methyl ether (PEG-b-PLA) on steroid hormone secretion by porcine granulosa cells

Scsuková

Bujnakova

Kiss

et al. 2017

Endocrine Regulations

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“…The Stern-Volmer Thermal perturbation techniques were used to monitor structural changes in the LH/hCG receptor induced by the action of tryptophan-modifying reagents on ovarian membranes. Thermal inactivation of hormone binding sites on the receptor molecule provides a direct approach to evaluate alterations of receptor conformation which occur as a result of hormone binding or perturbation of membrane bilayer (Artigues et al, 1989;Kolena et al, 1995). Thermal inactivation of the receptor is a rapid process.…”

Section: Resultsmentioning

confidence: 99%

“…We therefore studied the inhibitory effect of the oxidizing agent Nbromosuccinimide and of 2-hydroxy-5-nitrobenzyl bromide, reagents with specificity toward tryptophan (Koshland et al, 1964), with the aim to determine whether tryptophan residues are essential for the hCG binding to the receptor. The study analyzed also possible structure-functional relationships of the LH/ hCG receptor by intrinsic fluorescence and thermal perturbation techniques (Artigues et al 1989;Kolena et al, 1995) Amersham. All other chemicals were from Sigma.…”

Section: Endocrinology Anddiabetesmentioning

confidence: 99%

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Involvement of tryptophan in the structural alterations of the rat ovarian LH/hCG receptor

Kolena

Scsuková²,

Tatara³

et al. 2009

Exp Clin Endocrinol Diabetes

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Treatment of the rat ovarian membrane-bound and Triton X-100 solubilized LH/hCG receptor with the tryptophan-specific reagents N-bromosuccinimide (NBS) and 2-hydroxy-5-nitrobenzyl bromide (HNB-Br) resulted in inactivation of the receptor to bind hCG. Fluorescence quenching studies indicated that oxidation of tryptophan residues by NBS decreased the accessibility of fluorophores for acrylamide. Preceding binding of hCG to receptor sites was found to protect fluorophores from NBS action. Modification of tryptophan residues was associated with alteration in the rigidity of ovarian membranes and with destabilization of the LH/hCG receptor structure. The results suggest that tryptophan residue is essential for hCG binding to the receptor.

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“…We recently demonstrated that the desensitization of LH/hCG receptors in the rat was associated with changes in the order of ovarian membrane lipids (Kolena et al, 1994a). The present paper studies structure-functional relationships of the LH/hCG receptor in the process of short-term desensitization analyzed by intrinsic fluorescence and thermal perturbation techniques in its membrane environment (Kolena et al, 1994b;1995).…”

Section: Endocrinology Anddiabetesmentioning

confidence: 99%

Ligand-induced rapid desensitization causes structural alteration of rat ovarian LH/hCG receptor

Kolena

Scsuková²,

Ježová³

et al. 2009

Exp Clin Endocrinol Diabetes

Self Cite

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The role of the physical state of ovarian membranes was studied in the process of the early desensitization of the LH/hCG receptor. Thirty min after injection of a desensitizing dose of hCG to rats, the hCG-responsive adenylylcyclase activity was reduced, whereas hCG binding to ovarian membranes was still normal. Early desensitization decreased rigidity of membrane lipids, determined by fluorescence polarization of DPH. Possible structure-functional properties of the LH/hCG receptor were analyzed by thermal perturbation technique. Desensitization decreased thermal stability of the LH/hCG receptor in membranes and in proteoliposomes. Desensitization modified the quenching of protein fluorescence and intrinsic fluorescence spectral properties of membranes. The Stern-Volmer constants for control and desensitized membranes were found to be 4.3 and 5.5, respectively, indicating that desensitization elevated the accessibility of fluorophores for acrylamide. The changes of the physical properties of membranes resulting from desensitization was exhibited solely in the treatment with hCG in vivo, but not in vitro. The results suggest that the hCG-induced alteration of the physical state of luteal membranes may be a requirement for the induction of changes that lead to desensitization.

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Effect of phospholipids on the reconstitution and thermal stability of delipidated rat ovarian luteinizing hormone/human chorionic gonadotropin receptors in proteoliposomes

Cited by 5 publications

References 16 publications

Adverse eff ects of polymeric nanoparticle poly(ethylene glycol)- block-polylactide methyl ether (PEG-b-PLA) on steroid hormone secretion by porcine granulosa cells

Adverse eff ects of polymeric nanoparticle poly(ethylene glycol)- block-polylactide methyl ether (PEG-b-PLA) on steroid hormone secretion by porcine granulosa cells

Involvement of tryptophan in the structural alterations of the rat ovarian LH/hCG receptor

Ligand-induced rapid desensitization causes structural alteration of rat ovarian LH/hCG receptor

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