Effect of cryopreservation on human granulosa cell viability and responsiveness to gonadotropin.

In human, the use of freshly recovered granulosa cells for experiments remains difficult. Because of the single use of human cells, the experiments cannot be repeated, and no additional conditions can be tested afterwards with the cells of the same patient. Therefore, granulosa cell cryopreservation could be a good alternative to keep part of these cells for later controls or experiments.

Modulation of Gonadotropins Activity by Antibodies.

Gonadotropins are essential for reproduction control in humans as well as in animals. They are widely used all over the world for ovarian stimulation in women, spermatogenesis stimulation in men, and ovulation induction and superovulation in animals. Despite the availability of many different preparations, all are made of the native hormones.

Analysis of urinary cathepsin C for diagnosing Papillon-Lefèvre syndrome.

Papillon-Lefèvre syndrome (PLS) (OMIM: 245000) is a rare disease characterized by severe periodontitis and palmoplantar keratoderma. It is caused by mutations in both alleles of the cathepsin C (CatC) gene CTSC that completely abrogate the proteolytic activity of this cysteine proteinase. Most often, a genetic analysis to enable early and rapid diagnosis of PLS is unaffordable or unavailable.

Radioligand binding analysis as a tool for quality control of GPCR production for structural characterization: adenosine A(2a)R as a template for study.

Functional characterization of G protein-coupled receptors is essential to ascertain the suitability of a protein target for downstream studies and to help develop optimal expression and isolation procedures. Radioligand binding analysis is a well-established technique, which allows direct measurement of the amount of functional receptor in a sample. It can be readily applied to both membrane-bound and soluble receptor samples and is an ideal method for monitoring the amount of functional protein at each stage in the expression and isolation process.

Analysis of the actions of the novel dopamine receptor-directed compounds (S)-OSU6162 and ACR16 at the D2 dopamine receptor.

Unlabelled: BACKGROUND AND PURPOSE; The two phenylpiperidines, OSU6162 and ACR16, have been proposed as novel drugs for the treatment of brain disorders, including schizophrenia and Huntington's disease, because of their putative dopamine stabilizing effects. Here we evaluated the activities of these compounds in a range of assays for the D(2) dopamine receptor in vitro.

Experimental Approach: The affinities of these compounds for the D(2) dopamine receptor were evaluated in competition with [(3) H]spiperone and [(3) H]NPA.

A purified C-terminally truncated human adenosine A(2A) receptor construct is functionally stable and degradation resistant.

Recent high resolution structures of modified G-protein coupled receptors (GPCRs) have provided major insight into the mechanisms of receptor-ligand binding. However understanding of the complete mechanism of GPCR function remains limited. This study characterised C-terminally truncated versions of the human adenosine A(2A) receptor (A(2A)R) with a view to producing protein suitable for structural studies.

Co-operativity in agonist binding at the D2 dopamine receptor: evidence from agonist dissociation kinetics.

There is much evidence to suggest that G protein coupled receptors exist as oligomers but the relevance to their function is unclear. We have, therefore, examined the binding of the radiolabelled agonist [(3)H]NPA to membranes of CHO cells expressing the D(2) dopamine receptor in dissociation rate experiments. When [(3)H]NPA dissociation was started by dilution, the dissociation rate in the absence of sodium ions was unaffected by addition of the antagonist/inverse agonist (+)-butaclamol, but was accelerated by addition of agonists e.

[Does FSH signaling have a gender?].

FSH is the main endocrine control of mammalian reproduction. FSH triggers somatic cells of the gonads which support germ cells metabolically, i.e.

G protein-coupled receptor kinase 2 and beta-arrestins are recruited to FSH receptor in stimulated rat primary Sertoli cells.

FSH-receptor (FSH-R) signaling is regulated by agonist-induced desensitization and internalization. It has been shown, in a variety of overexpression systems, that G protein-coupled receptor kinases (GRKs) phosphorylate the activated FSH-R, promote beta-arrestin recruitment and ultimately lead to internalization. The accuracy of this mechanism has not yet been demonstrated in cells expressing these different molecules at physiological levels.

A phosphorylation cluster of five serine and threonine residues in the C-terminus of the follicle-stimulating hormone receptor is important for desensitization but not for beta-arrestin-mediated ERK activation.

Classically, the FSH receptor (FSH-R) mediates its effects through coupling to guanine nucleotide-binding protein alpha S subunit (Galpha(s)) and activation of the cAMP/protein kinase A (PKA) signaling pathway. beta-Arrestins are rapidly recruited to the FSH-activated receptor and play key roles in its desensitization and internalization. Here, we show that the FSH-R expressed in HEK 293 cells activated ERK by two temporally distinct pathways dependent, respectively, on Galpha(s)/PKA and beta-arrestins.

Follicle-stimulating hormone (FSH) activates extracellular signal-regulated kinase phosphorylation independently of beta-arrestin- and dynamin-mediated FSH receptor internalization.

Background: The follicle-stimulating hormone receptor (FSH-R) is a seven transmembrane spanning receptor (7TMR) which plays a crucial role in male and female reproduction. Upon FSH stimulation, the FSH-R activates the extracellular signal-regulated kinases (ERK). However, the mechanisms whereby the agonist-stimulated FSH-R activates ERK are poorly understood.

Follicle-stimulating hormone activates p70 ribosomal protein S6 kinase by protein kinase A-mediated dephosphorylation of Thr 421/Ser 424 in primary Sertoli cells.

FSH is a major hormonal input that drives Sertoli cells to their fully differentiated function in male reproduction. It is a physiologically important issue to define how FSH mediates its effects at the cellular level to regulate gene expression. FSH biological activities are transduced via a seven-spanned transmembrane receptor, the FSH-R, primarily leading to cAMP-dependent protein kinase A (PKA) activation and cAMP response element binding protein-mediated transcriptional responses.

A mechanistic overview on male infertility and germ cell cancers.

The testis is devoted to two important tasks: haploid cell production and sexual steroid synthesis. A number of highly sophisticated and unique strategies operate during spermatogenesis, a process crucial for reproduction, heredity and evolution. It is particularly important to decipher the underlying molecular mechanisms whose function can be perverted in pathological situations, such as infertility and testicular cancers, which represent an increasing biomedical issue today.