Heterogeneous hCG and hMG commercial preparations result in different intracellular signalling but induce a similar long-term progesterone response in vitro.

STUDY QUESTION: Are four urinary hCG/menotropin (hMG) and one recombinant preparation characterized by different molecular features and do they mediate specific intracellular signaling and steroidogenesis? SUMMARY ANSWER: hCG and hMG preparations have heterogeneous compositions and mediate preparation-specific cell signaling and early steroidogenesis, although similar progesterone plateau levels are achieved in 24 h-treated human primary granulosa cells in vitro. WHAT IS KNOWN ALREADY: hCG is the pregnancy hormone marketed as a drug for ARTs to induce final oocyte maturation and ovulation, and to support FSH action. Several hCG formulations are commercially available, differing in source, purification methods and biochemical composition. STUDY DESIGN, SIZE, DURATION: Commercial hCG preparations for ART or research purposes were compared in vitro. PARTICIPANTS/MATERIALS, SETTING, METHODS: The different preparations were quantified by immunoassay with calibration against the hCG standard (Fifth IS; NIBSC 07/364). Immunoreactivity patterns, isoelectric points and oligosaccharide contents of hCGs were evaluated using reducing and non-reducing Western blotting, capillary isoelectric-focusing immunoassay and lectin-ELISA, respectively. Functional studies were performed in order to evaluate intracellular and total cAMP, progesterone production and ß-arrestin 2 recruitment by ELISA and BRET, in both human primary granulosa lutein cells (hGLC) and luteinizing hormone (LH)/hCG receptor (LHCGR)-transfected HEK293 cells, stimulated by increasing hormone concentrations. Statistical analysis was performed using two-way ANOVA and Bonferroni post-test or Mann-Whitney's U-test as appropriate. MAIN RESULTS AND THE ROLE OF CHANCE: Heterogeneous profiles were found among preparations, revealing specific molecular weight patterns (20-75 KDa range), isoelectric points (4.0-9.0 pI range) and lectin binding (P < 0.05; n = 7-10). These drug-specific compositions were linked to different potencies on cAMP production (EC50 1.0-400.0 ng/ml range) and ß-arrestin 2 recruitment (EC50 0.03-2.0 µg/ml) in hGLC and transfected HEK293 cells (P < 0.05; n = 3-5). In hGLC, these differences were reflected by preparation-specific 8-h progesterone production although similar plateau levels of progesterone were acheived by 24-h treatment (P ≥ 0.05; n = 3). LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: The biological activity of commercial hCG/hMG preparations is provided in International Units (IU) by in-vivo bioassay and calibration against an International Standard, although it is an unsuitable unit of measure for in-vitro studies. The re-calibration against recombinant hCG,quantified in grams, is based on the assumption that all of the isoforms and glycosylation variants have similar immunoreactivity. WIDER IMPLICATIONS OF THE FINDINGS: hCG/hMG preparation-specific cell responses in vitro may be proposed to ART patients affected by peculiar ovarian response, such as that caused by polycystic ovary syndrome. Otherwise, all the preparations available for ART may provide a similar clinical outcome in healthy women. STUDY FUNDING AND COMPETING INTEREST(S): This study was supported by a grant of the Italian Ministry of Education, University and Research (PRIN 2015XCR88M). The authors have no conflict of interest.

Proteomic analyses of recombinant human follicle-stimulating hormone and urinary-derived gonadotropin preparations.

OBJECTIVE: To understand the properties of each available gonadotropin preparation, especially in terms of the differences between urinary-derived and recombinant preparations. STUDY DESIGN: Human menopausal gonadotropin (hMG), highly purified urinary-derived follicle-stimulating hormone (uFSH-HP) and recombinant FSH (rFSH) were subjected to 2-dimensional gel electrophoresis (2-DE), and protein spots were visualized by silver-staining procedures. Major spots were analyzed by mass spectrometry. Fluorescent-labeled preparations were also subjected to 2-DE to evaluate the quantities of FSH isohormones contained in each preparation. RESULTS: 2-DE and mass spectrometry analyses of hMG identified many extracellular proteins as major impurities and several plasma membrane proteins including prion proteins. Both uFSH-HP and rFSH demonstrated slight impurities and showed several alpha and beta subunit isohormones. rFSH contained higher amounts of the basic isohormones of the alpha subunit than uFSH-HP, whereas the predominance of the basic isohormones was less significant in the beta subunit. CONCLUSION: Proteomic analyses demonstrated the detailed protein profiles of each preparation. Differences in the quantities of alpha subunit isohormones may contribute to the variations in FSH activity observed between recombinant and urinary-derived FSH preparations.

Highly purified HMG versus recombinant FSH for ovarian stimulation in IVF cycles.

The objective of this study was to compare the live birth rates resulting from ovarian stimulation with highly purified human menopausal gonadotrophin (HP-HMG), which combines FSH and human chorionic gonadotrophin-driven LH activities, or recombinant FSH (rFSH) alone in women undergoing IVF cycles. An integrated analysis was performed of the raw data from two randomized controlled trials that were highly comparable in terms of eligibility criteria and post-randomization treatment regimens with either HP-HMG or rFSH for ovarian stimulation in IVF, following a long down-regulation protocol. All randomized subjects who received at least one dose of gonadotrophin in an IVF cycle (HP-HMG, n = 491; rFSH, n = 495) were included in the analysis. Subjects who underwent intracytoplasmic sperm injection cycles were excluded. The superiority of one gonadotrophin preparation over the other was tested using the likelihood ratio test in a logistic regression analysis. The live birth rate per cycle initiated was 26.5% (130/491) with HP-HMG and 20.8% (103/495) with rFSH (P = 0.041). The odds ratio in favour of HP-HMG was 1.36 (95% confidence interval: 1.01-1.83). Thus, the findings of this integrated analysis demonstrate that ovarian stimulation with HP-HMG, following a long down-regulation protocol, in IVF cycles results in significantly more live births than stimulation with rFSH alone.

FSH isoform composition of commercial gonadotrophin preparations: a neglected aspect?

The clinical efficacy of commercial gonadotrophin preparations has been the subject of an intense debate during recent years. Arguments have primarily focused on the origin of FSH activity (urine versus recombinant derived) and whether the preparation included LH-like activity. FSH isoform composition has received little or no attention, and is usually considered to have negligible effect on clinical effectiveness. By presenting the available data on the FSH isoform composition of commercial gonadotrophin preparations, the present paper challenges this assumption. To evaluate whether the FSH isoform composition affected the efficacy of a product, a meta-analysis was performed that compared a preparation expressing an acidic isoform profile (urinary-derived Metrodin-HP) with a preparation rich in less acidic isoforms (recombinant derived Gonal F). A total of five randomized clinical trials that specifically compared these two preparations was identified and included in the analysis. All parameters relating to the direct effect of FSH on the follicle differed significantly in favour of the product rich in less acidic isoforms, while data on pregnancy outcome did not reach significance. The importance of the FSH isoform profile and whether the FSH is derived from urine or by recombinant technique is discussed in relation to clinical efficacy. It is suggested that the FSH isoform profile of commercial gonadotrophin preparations is of clinical importance and should be taken into account when evaluating efficacy.

From HMG through purified urinary FSH preparations to recombinant FSH: a substitution study.

Drugs produced through the use of recombinant DNA techniques have become an integral part of medical practice. Before recombinant FSH (rFSH) was introduced in 1996, FSH purified from the urine of postmenopausal women had been commercially available since the 1960s. We analysed the diffusion and the substitution patterns of the different FSH preparations in The Netherlands. The fact that rFSH preparations have batch-to-batch consistency, are free from urinary protein contaminants and have the potential to be produced in limitless quantities, is advantageous. The question whether newer, more pure FSH products are beneficial from the clinical perspective, has not been settled beyond reasonable doubt. The price of rFSH is three times as high as the price of the former FSH preparations. Due to the introduction of rFSH, total FSH expenditures have grown from 5.0 million Euros in 1995, to 26.8 million Euros in 2000, while the volume increased by <100%. Both the pharmaceutical companies and purchasers (government, insurers) have influenced the patterns of substitution of existing FSH products by biotech equivalents. In general, the risk of increasing pharmaceutical costs without clear clinical benefits has to be set against the risk of strangling innovations. Therefore, a continuous process of technology assessment is necessary.

Recent advances in FRET: distance determination in protein-DNA complexes.

Fluorescence resonance energy transfer (FRET) provides information on the distance between a donor and an acceptor dye in the range 10 to 100 A. Knowledge of the exact positions of some dyes with respect to nucleic acids now enables us to translate these data into precise structural information using molecular modeling. Advances in the preparation of dye-labeled nucleic acid molecules and in new techniques, such as the measurement of FRET in polyacrylamide gels or in vivo, will lead to an increasingly important role of FRET in structural and molecular biology.

Floppy SOX: mutual induced fit in hmg (high-mobility group) box-DNA recognition.

The high-mobility group (HMG) box defines a DNA-bending motif of broad interest in relation to human development and disease. Major and minor wings of an L-shaped structure provide a template for DNA bending. As in the TATA-binding protein and a diverse family of factors, insertion of one or more side chains between base pairs induces a DNA kink. The HMG box binds in the DNA minor groove and may be specific for DNA sequence or distorted DNA architecture. Whereas the angular structures of non-sequence-specific domains are well ordered, free SRY and related autosomal SOX domains are in part disordered. Observations suggesting that the minor wing lacks a fixed tertiary structure motivate the hypothesis that DNA bending and stabilization of protein structure define a coupled process. We further propose that mutual induced fit in SOX-DNA recognition underlies the sequence dependence of DNA bending and enables the induction of promoter-specific architectures.

[The clinical significance of the ratio in FSH/LH of human menopausal gonadotropins in a programmed stimulation regimen for IVF-ET].

Human menopausal Gonadotropin (hMG) has been used in controlled ovarian hyperstimulation (COH) protocol for IVF-ET. We investigated three hMG preparations with different FSH/LH ratios to determine their clinical effectiveness in a programmed stimulation regimen for IVF-ET. Eighty-four IVF-ET candidates at Toho University Hospital received injections of an hMG preparation containing a 3:1 ratio of FSH/LH: Group A, 36 patients received hMG at an FSH/LH 1 : 1 ratio: Group B, and 20 patients receive pure FSH : group C. All received injections of 300IU hMG daily for 7 days according to our COH protocol (=7-day schedule). Analysis determined the serum levels of E2, number of mature follicles, number of retrieved oocytes, fertilization rate, cleavage rate, number of transferred embryos and pregnancy rate. The results were as follows: 1. The serum E2 level was higher in Group A than in Group C with significant differences. 2. The oocyte retrieval rate was significantly higher in Group A. 3. The rate of equally cleaved eggs was significantly higher in Group A. 4. The pregnancy rate was significantly higher in Group A. In conclusion, an hMG preparation containing a 3 : 1 FSH/LH ratio was most suitable in our COH protocol.

Composition of commercial gonadotrophin preparations extracted from human post-menopausal urine: characterization of non-gonadotrophin proteins.

Gonadotrophin preparations extracted from post-menopausal urine are of low purity and the major protein components are not gonadotrophins. A study was undertaken to identify some of these non-gonadotrophin proteins present in the extracted human urinary gonadotrophin preparations that are commercially available, i.e. Humegon (Organon), HMG Massone (Massone), Metrodin (Serono), Metrodin HP (Serono), Pergonal (Serono) and Progonadyl (Elea). As revealed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) with Coomassie blue staining and Western blotting analysis, these products had electrophoretic protein profiles which differed in the amounts and species of proteins present. With the exception of Metrodin HP, all the other preparations tested contained tumour necrosis factor binding protein-I, transferrin, and immunoglobulin-related proteins. Some of the products contained in addition: urokinase, Tamm-Horsfall glycoprotein and epidermal growth factor. Recently, a highly purified human urinary follicle stimulating hormone (FSH) preparation (Metrodin HP) became available. In this preparation human FSH represents > 95% of the total proteins (approximately 10,000 IU of FSH/mg of protein). Metrodin HP was demonstrated to be the purest preparation tested, with none of the above-mentioned contaminants detected.

Human chorionic gonadotropin in commercial human menopausal gonadotropin preparations.

Several studies indicated the presence of an hCG-immunoreactive substance in commercial hMG preparations. Because hCG represents LH activity with a relatively very long half-life, differences between hMG preparations with respect to hCG content could imply clinical differences. To investigate whether there is any difference in this respect between the two most widely used hMG preparations, we measured the hCG content of ampules of Humegon and Pergonal retrieved from the market, together representing 51 separate production batches, with one or more different specific immunological assays. There are no significant differences between Humegon and Pergonal with respect to the mean hCG level per ampule as measured by RIA, ELISA, and Delfia. The batch-to-batch consistency for Humegon is higher.

Reconstitution of short-spaced chromatin from the histone octamer and either HMG-14,17 or histone H1.

Two new chromatin-assembly reactions are described. The first involves the addition of phosphorylated HMG-14,17 to the histone octamer plus DNA in high concentrations of salt and yields a repeating particle size or spacing of about 165 base-pairs. The second involves the addition of histone H1 to the acetylated histone octamer plus poly(glutamate) in low concentrations of salt, followed by the addition of DNA; and it yields a spacing of about 170 base-pairs. Plots of band size versus band number in gels, often used to determine nucleosome repeat-length, yield slopes of 138 base-pairs for the histone octamer alone, or 155 base-pairs with HMG-14,17 or 160 base-pairs with histone H1, and intercepts of 10,25 and 20 base-pairs, respectively, in the three cases. Attempts were made to combine the spacing activities of HMG-14,17 and histone H1 within a single assembly reaction, to provide an even longer spacing of about 190 base-pairs (as observed in cell extracts to which H1 has been added), but our present methods did not allow this. The two assembly reactions described here will be of use for structural studies of chromatin having defined length and sequence, and potentially of practical use for the regular, ordered condensation of very long DNA.

Human chorionic gonadotrophin contributes to the bioactivity of Pergonal.

OBJECTIVE: We examined batch variation in the LH-like bioactive content of Pergonal and determined whether hCG contributes to this. DESIGN: Random selection of three batches of Pergonal, consisting of three ampoules in each batch. MEASUREMENTS: The LH content in each ampoule was determined by radioimmunoassay (R-LH), immunoradiometric assay (I-LH) and in vitro Leydig cell bioassay (B-LH) using the urinary hMG International Standard 70/45. Human chorionic gonadotrophin was determined by immunoradiometric assay (I-hCG) using the hCG IRP 75/537. The isohormone content of each batch was examined by chromatofocussing over the range pH 4.5-7.0 and the fractions collected were assayed for LH and hCG content. The variability in potency between batches was assessed by single factor analysis of variance. RESULTS: The gonadotrophin content of each batch (IU/ampoule, mean +/- SEM, n = 3 ampoules) was R-LH (40.9 +/- 0.5, 40.8 +/- 0.2, 39.3 +/- 0.7, P > 0.15), I-LH (39.0 +/- 1.5, 28.3 +/- 0.8, 36.9 +/- 3.3, P < 0.001), B-LH (27.3 +/- 0.3, 12.0 +/- 0.9, 19.3 +/- 0.9, P < 0.001) and I-hCG (16.4 +/- 0.7, 11.7 +/- 0.2, 10.5 +/- 0.5, P < 0.001). The chromatofocussing recoveries below pH 5.5 expressed as a percentage of the total amount of analyte eluted from the column and collated for all three batches of Pergonal were (mean % +/- SD, n = 3 batches) R-LH (58.4 +/- 4.0), I-LH (41.3 +/- 7.5), B-LH (81.4 +/- 2.8) and I-hCG (87.8 +/- 3.7). CONCLUSIONS: There was significant batch variation in the I-LH, B-LH and I-hCG (P < 0.001) but not the R-LH (P > 0.15) content of Pergonal. More than 80% of the total B-LH recovery chromatofocussed below pH 5.5 and corresponded to the region of highest I-hCG (> 87%) and lowest I-LH (< 42%) recovery. This was highly suggestive of hCG contributing to the LH-like bioactivity of Pergonal.

Between-lot variability in chromatographic and biochemical properties of hMG.

Ten lots of dissociated hMG were characterized by reverse-phase gradient high-performance liquid chromatography. Areas of 12 discrete peaks were directly related to dosages of hMG injected. The lots were further analysed for immunoactive-FSH (41.6-106.2 IU/ampule), immunoactive-LH (11.0-20.4 IU/ampule), bioactive-LH (2.7-17.1 IU/ampule) and bioactive-hMG (149-298 pg E2/mIU immunoactive-FSH/ml). Relationships between integrated areas of the HPLC peaks and biochemical properties of the hMG lots were analysed by stepwise multiple linear regression. Between-lot differences in immunoactive-LH and immunoactive-FSH were related to HPLC peak areas (p less than 0.05); differences in bioactive-LH were not. Areas of 8 peaks were related to differences in bioactive-hMG activity, facilitating close approximation of bioactive-hMG from the derived multi-linear model (p less than 0.001). Rapid characterization of hMG by HPLC is of relevance as recent reports have shown that ovarian responses and pregnancy outcomes of patients are related to the immunoactive and bioactive gonadotropin content of hMG preparations used to induce multiple folliculogenesis before oocyte aspiration, in vitro fertilization, and embryo replacement.