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Butnev VY, May JV, Brown AR, Sharma T, Butnev VY, White WK, Harvey DJ, Bousfield GR. Human FSH Glycoform α-Subunit Asparagine 52 Glycans: Major Glycan Structural Consistency, Minor Glycan Variation in Abundance. Front Endocrinol (Lausanne) 2022; 13:767661. [PMID: 36329887 PMCID: PMC9623679 DOI: 10.3389/fendo.2022.767661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 05/26/2022] [Indexed: 11/13/2022] Open
Abstract
Follicle-stimulating hormone (FSH), an α/β heterodimeric glycoprotein hormone, consists of functionally significant variants resulting from the presence or absence of either one of two FSHβ subunit N-glycans. The two most abundant variants are fully-glycosylated FSH24 (based on 24 kDa FSHβ band in Western blots) and hypo-glycosylated FSH21 (21 kDa band, lacks βAsn24 glycans). Due to its ability to bind more rapidly to the FSH receptor and occupy more FSH binding sites than FSH24, hypo-glycosylated FSH21 exhibits greater biological activity. Endoglycosidase F1-deglycosylated FSH bound to the complete extracellular domain of the FSH receptor crystallized as a trimeric complex. It was noted that a single biantennary glycan attached to FSHα Asn52 might preemptively fill the central pocket in this complex and prevent the other two FSH ligands from binding the remaining ligand-binding sites. As the most active FSH21 preparations possessed more rapidly migrating α-subunit bands in Western blots, we hypothesized that Asn52 glycans in these preparations were small enough to enable greater FSH21 receptor occupancy in the putative FSHR trimer model. Highly purified hFSH oligosaccharides derived from each FSH subunit, were characterized by electrospray ionization-ion mobility-collision-induced dissociation (ESI-IM-CID) mass spectrometry. FSHβ glycans typically possessed core-linked fucose and were roughly one third bi-antennary, one third tri-antennary and one third tetra-antennary. FSHα oligosaccharides largely lacked core fucose and were bi- or tri-antennary. Those αAsn52 glycans exhibiting tetra-antennary glycan m/z values were found to be tri-antennary, with lactosamine repeats accounting for the additional mass. Selective αAsn52 deglycosylation of representative pituitary hFSH glycoform Superdex 75 gel filtration fractions followed by ESI-IM-CID mass spectrometry revealed tri-antennary glycans predominated even in the lowest molecular weight FSH glycoforms. Accordingly, the differences in binding capacity of the same receptor preparation to different FSH glycoforms are likely the organization of the FSH receptor in cell membranes, rather than the αAsn52 oligosaccharide.
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Affiliation(s)
- Viktor Y Butnev
- Department of Biological Sciences, Wichita State University, Wichita, KS, United States
| | - Jeffrey V May
- Department of Biological Sciences, Wichita State University, Wichita, KS, United States
| | - Alan R Brown
- Department of Biological Sciences, Wichita State University, Wichita, KS, United States
| | - Tarak Sharma
- Department of Biological Sciences, Wichita State University, Wichita, KS, United States
| | - Vladimir Y Butnev
- Department of Biological Sciences, Wichita State University, Wichita, KS, United States
| | - William K White
- Department of Biological Sciences, Wichita State University, Wichita, KS, United States
| | - David J Harvey
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - George R Bousfield
- Department of Biological Sciences, Wichita State University, Wichita, KS, United States
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Hua G, George JW, Clark KL, Jonas KC, Johnson GP, Southekal S, Guda C, Hou X, Blum HR, Eudy J, Butnev VY, Brown AR, Katta S, May JV, Bousfield GR, Davis JS. Hypo-glycosylated hFSH drives ovarian follicular development more efficiently than fully-glycosylated hFSH: enhanced transcription and PI3K and MAPK signaling. Hum Reprod 2021; 36:1891-1906. [PMID: 34059912 PMCID: PMC8213452 DOI: 10.1093/humrep/deab135] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 03/31/2021] [Indexed: 12/22/2022] Open
Abstract
STUDY QUESTION Does hypo-glycosylated human recombinant FSH (hFSH18/21) have greater in vivo bioactivity that drives follicle development in vivo compared to fully-glycosylated human recombinant FSH (hFSH24)? SUMMARY ANSWER Compared with fully-glycosylated hFSH, hypo-glycosylated hFSH has greater bioactivity, enabling greater follicular health and growth in vivo, with enhanced transcriptional activity, greater activation of receptor tyrosine kinases (RTKs) and elevated phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) and Mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) signaling. WHAT IS KNOWN ALREADY Glycosylation of FSH is necessary for FSH to effectively activate the FSH receptor (FSHR) and promote preantral follicular growth and formation of antral follicles. In vitro studies demonstrate that compared to fully-glycosylated recombinant human FSH, hypo-glycosylated FSH has greater activity in receptor binding studies, and more effectively stimulates the PKA pathway and steroidogenesis in human granulosa cells. STUDY DESIGN, SIZE, DURATION This is a cross-sectional study evaluating the actions of purified recombinant human FSH glycoforms on parameters of follicular development, gene expression and cell signaling in immature postnatal day (PND) 17 female CD-1 mice. To stimulate follicle development in vivo, PND 17 female CD-1 mice (n = 8-10/group) were treated with PBS (150 µl), hFSH18/21 (1 µg/150 µl PBS) or hFSH24 (1 µg/150 µl PBS) by intraperitoneal injection (i.p.) twice daily (8:00 a.m. and 6:00 p.m.) for 2 days. Follicle numbers, serum anti-Müllerian hormone (AMH) and estradiol levels, and follicle health were quantified. PND 17 female CD-1 mice were also treated acutely (2 h) in vivo with PBS, hFSH18/21 (1 µg) or hFSH24 (1 µg) (n = 3-4/group). One ovary from each mouse was processed for RNA sequencing analysis and the other ovary processed for signal transduction analysis. An in vitro ovary culture system was used to confirm the relative signaling pathways. PARTICIPANTS/MATERIALS, SETTING, METHODS The purity of different recombinant hFSH glycoforms was analyzed using an automated western blot system. Follicle numbers were determined by counting serial sections of the mouse ovary. Real-time quantitative RT-PCR, western blot and immunofluorescence staining were used to determine growth and apoptosis markers related with follicle health. RNA sequencing and bioinformatics were used to identify pathways and processes associated with gene expression profiles induced by acute FSH glycoform treatment. Analysis of RTKs was used to determine potential FSH downstream signaling pathways in vivo. Western blot and in vitro ovarian culture system were used to validate the relative signaling pathways. MAIN RESULTS AND THE ROLE OF CHANCE Our present study shows that both hypo- and fully-glycosylated recombinant human FSH can drive follicular growth in vivo. However, hFSH18/21 promoted development of significantly more large antral follicles compared to hFSH24 (P < 0.01). In addition, compared with hFSH24, hFSH18/21 also promoted greater indices of follicular health, as defined by lower BAX/BCL2 ratios and reduced cleaved Caspase 3. Following acute in vivo treatment with FSH glycoforms RNA-sequencing data revealed that both FSH glycoforms rapidly induced ovarian transcription in vivo, but hypo-glycosylated FSH more robustly stimulated Gαs and cAMP-mediated signaling and members of the AP-1 transcription factor complex. Moreover, hFSH18/21 treatment induced significantly greater activation of RTKs, PI3K/AKT and MAPK/ERK signaling compared to hFSH24. FSH-induced indices of follicle growth in vitro were blocked by inhibition of PI3K and MAPK. LARGE SCALE DATA RNA sequencing of mouse ovaries. Data will be shared upon reasonable request to the corresponding author. LIMITATIONS, REASONS FOR CAUTION The observations that hFSH glycoforms have different bioactivities in the present study employing a mouse model of follicle development should be verified in nonhuman primates. The gene expression studies reflect transcriptomes of whole ovaries. WIDER IMPLICATIONS OF THE FINDINGS Commercially prepared recombinant human FSH used for ovarian stimulation in human ART is fully-glycosylated FSH. Our findings that hypo-glycosylated hFSH has greater bioactivity enabling greater follicular health and growth without exaggerated estradiol production in vivo, demonstrate the potential for its development for application in human ART. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by NIH 1P01 AG029531, NIH 1R01 HD 092263, VA I01 BX004272, and the Olson Center for Women's Health. JSD is the recipient of a VA Senior Research Career Scientist Award (1IK6 BX005797). This work was also partially supported by National Natural Science Foundation of China (No. 31872352). The authors declared there are no conflicts of interest.
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Affiliation(s)
- Guohua Hua
- Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science & Technology, Huazhong Agricultural University, Wuhan, Hubei, China
- Department of Obstetrics and Gynecology, Olson Center for Women’s Health, University of Nebraska Medical Center, Omaha, NE, USA
| | - Jitu W George
- Department of Obstetrics and Gynecology, Olson Center for Women’s Health, University of Nebraska Medical Center, Omaha, NE, USA
- Veterans Affairs Nebraska Western Iowa Health Care System, Omaha, NE, USA
| | - Kendra L Clark
- Department of Obstetrics and Gynecology, Olson Center for Women’s Health, University of Nebraska Medical Center, Omaha, NE, USA
- Veterans Affairs Nebraska Western Iowa Health Care System, Omaha, NE, USA
| | - Kim C Jonas
- Department of Women and Children’s Health, School of Life Course Sciences, King’s College London, Guy’s Campus, London, UK
| | - Gillian P Johnson
- Department of Women and Children’s Health, School of Life Course Sciences, King’s College London, Guy’s Campus, London, UK
| | - Siddesh Southekal
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE, USA
| | - Chittibabu Guda
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE, USA
| | - Xiaoying Hou
- Department of Obstetrics and Gynecology, Olson Center for Women’s Health, University of Nebraska Medical Center, Omaha, NE, USA
| | - Haley R Blum
- Department of Obstetrics and Gynecology, Olson Center for Women’s Health, University of Nebraska Medical Center, Omaha, NE, USA
| | - James Eudy
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE, USA
| | - Viktor Y Butnev
- Department of Biological Sciences, Wichita State University, Wichita, KS, USA
| | - Alan R Brown
- Department of Biological Sciences, Wichita State University, Wichita, KS, USA
| | - Sahithi Katta
- Department of Biological Sciences, Wichita State University, Wichita, KS, USA
| | - Jeffrey V May
- Department of Biological Sciences, Wichita State University, Wichita, KS, USA
| | - George R Bousfield
- Department of Biological Sciences, Wichita State University, Wichita, KS, USA
| | - John S Davis
- Department of Obstetrics and Gynecology, Olson Center for Women’s Health, University of Nebraska Medical Center, Omaha, NE, USA
- Veterans Affairs Nebraska Western Iowa Health Care System, Omaha, NE, USA
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Identification and Relative Quantification of hFSH Glycoforms in Women's Sera via MS-PRM-Based Approach. Pharmaceutics 2021; 13:pharmaceutics13060798. [PMID: 34071747 PMCID: PMC8226871 DOI: 10.3390/pharmaceutics13060798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 04/23/2021] [Accepted: 04/28/2021] [Indexed: 11/17/2022] Open
Abstract
Follicle-stimulating hormone (FSH) is a glycohormone synthesized by adenohypophysis, and it stimulates ovulation in women and spermatogenesis in men by binding to its receptor (FSHR). FSHR is involved in several mechanisms to transduce intracellular signals in response to the FSH stimulus. Exogenous FSH is currently used in the clinic for ovarian hyperstimulation during in vitro fertilization in women, and for treatment of infertility caused by gonadotropin deficiency in men. The glycosylation of FSH strongly affects the binding affinity to its receptor, hence significantly influencing the biological activity of the hormone. Therefore, the accurate measurement and characterization of serum hFSH glycoforms will contribute to elucidating the complex mechanism of action by which different glycoforms elicit distinct biological activity. Nowadays ELISA is the official method with which to monitor serum hFSH, but the test is unable to distinguish between the different FSH glycovariants and is therefore unsuitable to study the biological activity of this hormone. This study presents a preliminary alternative strategy for identifying and quantifying serum hFSH glycoforms based on immunopurification assay and mass spectrometry (MS), and parallel reaction monitoring (PRM) analysis. In this study, we provide an MS–PRM data acquisition method for hFSH glycopeptides identification with high specificity and their quantification by extracting the chromatographic traces of selected fragments of glycopeptides. Once set up for all its features, the proposed method could be transferred to the clinic to improve fertility treatments and follow-ups in men and women.
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Abstract
Gonadotropins are glycoprotein sex hormones regulating development and reproduction and bind to specific G protein–coupled receptors expressed in the gonads. Their effects on multiple signaling cascades and intracellular events have recently been characterized using novel technological and scientific tools. The impact of allosteric modulators on gonadotropin signaling, the role of sugars linked to the hormone backbone, the detection of endosomal compartments supporting signaling modules, and the dissection of different effects mediated by these molecules are areas that have advanced significantly in the last decade. The classic view providing the exclusive activation of the cAMP/protein kinase A (PKA) and the steroidogenic pathway by these hormones has been expanded with the addition of novel signaling cascades as determined by high-resolution imaging techniques. These new findings provided new potential therapeutic applications. Despite these improvements, unanswered issues of gonadotropin physiology, such as the intrinsic pro-apoptotic potential to these hormones, the existence of receptors assembled as heteromers, and their expression in extragonadal tissues, remain to be studied. Elucidating these issues is a challenge for future research.
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Affiliation(s)
- Livio Casarini
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Via G. Campi 287, 41125 Modena, Italy
- Center for Genomic Research, University of Modena and Reggio Emilia, Via G. Campi 287, 41125 Modena, Italy
| | - Manuela Simoni
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Via G. Campi 287, 41125 Modena, Italy
- Center for Genomic Research, University of Modena and Reggio Emilia, Via G. Campi 287, 41125 Modena, Italy
- Unit of Endocrinology, Department of Medical Specialties, Azienda Ospedaliero-Universitaria di Modena, Via P. Giardini 1355, 41126 Modena, Italy
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Dias JA, Ulloa-Aguirre A. New Human Follitropin Preparations: How Glycan Structural Differences May Affect Biochemical and Biological Function and Clinical Effect. Front Endocrinol (Lausanne) 2021; 12:636038. [PMID: 33815292 PMCID: PMC8018285 DOI: 10.3389/fendo.2021.636038] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 02/09/2021] [Indexed: 12/21/2022] Open
Abstract
It is well accepted that pituitary follitropin is secreted into the circulation as a mixture of variants, which differ not in primary structure but rather at the level of glycosylation. These glycosidic forms vary in the number of glycosylation sites filled, complexity of glycosidic chains, and sialylation and sulfation. It is generally agreed that high sialylation, 2,3 sialic acid capping of terminal N-acetyl galactosamine or galactose leads to longer circulating half-life, by blocking binding of asialoglycoprotein receptor (ASGPR) in the liver. In contrast, 2,6 sialic acid found in humans does not prevent recognition of galactose and N-acetyl galactosamine by ASGPR. Few studies on clinical outcomes comparing differences in sialylation of follitropin found in commercially available preparations are available. Thus, there is a clear need for a consortium of open data to address this unmet need. Recently, FSH glycosylation, primarily on the β-subunit, which varies as women age, has emerged as a key modifier of follitropin action, with profound biological effects in vivo in animal models. To date, limited information of recombinant follitropin hormone preparations is available. Thus, most of the studies with FSH that is well characterized biochemically have been done in vitro, with engineered non gonadal host cells bearing recombinant receptors or in animal models. Since limited studies in human granulosa cells are available, a question is whether structural differences in glycosylation in commercially available follitropin affects biological function and clinical effect in humans. The presence of fucose, for example, has not been studied greatly even though, in the case of antibody therapy it has been shown to have a large effect on antibody targeting. This review on glycosidic variability of follitropin from the biochemical/structural point of view reflects on this question and presents an assessment in the context of available published data. If clinical differences are to be expected or not, the readers will have a better understanding of the evidence for and limitations of such expectations.
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Affiliation(s)
- James A. Dias
- Department of Biomedical Sciences, State University of New York at Albany, Albany, NY, United States
- *Correspondence: James A. Dias,
| | - Alfredo Ulloa-Aguirre
- Red de Apoyo a la Investigación, National University of Mexico-Instituto Nacional de Ciencias Médicas y Nutrición SZ., Mexico City, Mexico
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Zariñán T, Butnev VY, Gutiérrez-Sagal R, Maravillas-Montero JL, Martínez-Luis I, Mejía-Domínguez NR, Juárez-Vega G, Bousfield GR, Ulloa-Aguirre A. In Vitro Impact of FSH Glycosylation Variants on FSH Receptor-stimulated Signal Transduction and Functional Selectivity. J Endocr Soc 2020; 4:bvaa019. [PMID: 32342021 PMCID: PMC7175721 DOI: 10.1210/jendso/bvaa019] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 02/14/2020] [Indexed: 12/21/2022] Open
Abstract
FSH exists as different glycoforms that differ in glycosylation of the hormone-specific β-subunit. Tetra-glycosylated FSH (FSH24) and hypo-glycosylated FSH (FSH18/21) are the most abundant glycoforms found in humans. Employing distinct readouts in HEK293 cells expressing the FSH receptor, we compared signaling triggered by human pituitary FSH preparations (FSH18/21 and FSH24) as well as by equine FSH (eFSH), and human recombinant FSH (recFSH), each exhibiting distinct glycosylation patterns. The potency in eliciting cAMP production was greater for eFSH than for FSH18/21, FSH24, and recFSH, whereas in the ERK1/2 activation readout, potency was highest for FSH18/21 followed by eFSH, recFSH, and FSH24. In β-arrestin1/2 CRISPR/Cas9 HEK293-KO cells, FSH18/21 exhibited a preference toward β-arrestin-mediated ERK1/2 activation as revealed by a drastic decrease in pERK during the first 15-minute exposure to this glycoform. Exposure of β-arrestin1/2 KO cells to H89 additionally decreased pERK1/2, albeit to a significantly lower extent in response to FSH18/21. Concurrent silencing of β-arrestin and PKA signaling, incompletely suppressed pERK response to FSH glycoforms, suggesting that pathways other than those dependent on Gs-protein and β-arrestins also contribute to FSH-stimulated pERK1/2. All FSH glycoforms stimulated intracellular Ca2+ (iCa2+) accumulation through both influx from Ca2+ channels and release from intracellular stores; however, iCa2+ in response to FSH18/21 depended more on the latter, suggesting differences in mechanisms through which glycoforms promote iCa2+ accumulation. These data indicate that FSH glycosylation plays an important role in defining not only the intensity but also the functional selectivity for the mechanisms leading to activation of distinct signaling cascades.
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Affiliation(s)
- Teresa Zariñán
- Red de Apoyo a la Investigación (RAI), Universidad Nacional Autónoma de México (UNAM)-Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Viktor Y Butnev
- Department of Biological Sciences, Wichita State University, Wichita, Kansas, USA
| | - Rubén Gutiérrez-Sagal
- Red de Apoyo a la Investigación (RAI), Universidad Nacional Autónoma de México (UNAM)-Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - José Luis Maravillas-Montero
- Red de Apoyo a la Investigación (RAI), Universidad Nacional Autónoma de México (UNAM)-Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Iván Martínez-Luis
- Red de Apoyo a la Investigación (RAI), Universidad Nacional Autónoma de México (UNAM)-Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Nancy R Mejía-Domínguez
- Red de Apoyo a la Investigación (RAI), Universidad Nacional Autónoma de México (UNAM)-Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Guillermo Juárez-Vega
- Red de Apoyo a la Investigación (RAI), Universidad Nacional Autónoma de México (UNAM)-Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - George R Bousfield
- Department of Biological Sciences, Wichita State University, Wichita, Kansas, USA
| | - Alfredo Ulloa-Aguirre
- Red de Apoyo a la Investigación (RAI), Universidad Nacional Autónoma de México (UNAM)-Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
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Bousfield GR, Harvey DJ. Follicle-Stimulating Hormone Glycobiology. Endocrinology 2019; 160:1515-1535. [PMID: 31127275 PMCID: PMC6534497 DOI: 10.1210/en.2019-00001] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 04/16/2019] [Indexed: 01/13/2023]
Abstract
FSH glycosylation varies in two functionally important aspects: microheterogeneity, resulting from oligosaccharide structure variation, and macroheterogeneity, arising from partial FSHβ subunit glycosylation. Although advances in mass spectrometry permit extensive characterization of FSH glycan populations, microheterogeneity remains difficult to illustrate, and comparisons between different studies are challenging because no standard format exists for rendering oligosaccharide structures. FSH microheterogeneity is illustrated using a consistent glycan diagram format to illustrate the large array of structures associated with one hormone. This is extended to commercially available recombinant FSH preparations, which exhibit greatly reduced microheterogeneity at three of four glycosylation sites. Macroheterogeneity is demonstrated by electrophoretic mobility shifts due to the absence of FSHβ glycans that can be assessed by Western blotting of immunopurified FSH. Initially, macroheterogeneity was hoped to matter more than microheterogeneity. However, it now appears that both forms of carbohydrate heterogeneity have to be taken into consideration. FSH glycosylation can reduce its apparent affinity for its cognate receptor by delaying initial interaction with the receptor and limiting access to all of the available binding sites. This is followed by impaired cellular signaling responses that may be related to reduced receptor occupancy or biased signaling. To resolve these alternatives, well-characterized FSH glycoform preparations are necessary.
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Affiliation(s)
- George R Bousfield
- Department of Biological Sciences, Wichita State University, Wichita, Kansas
- Correspondence: George R. Bousfield, PhD, Department of Biological Sciences, Wichita State University, 1845 Fairmount Street, Wichita, Kansas 67260. E-mail: ; or David J. Harvey, DSc, Target Discovery Institute, Nuffield Department of Medicine, University of Oxford. Roosevelt Drive, Oxford OX3 7FZ, United Kingdom. E-mail:
| | - David J Harvey
- Target Discovery Institute, Nuffield Department of Medicine, Oxford University, Oxford, United Kingdom
- Correspondence: George R. Bousfield, PhD, Department of Biological Sciences, Wichita State University, 1845 Fairmount Street, Wichita, Kansas 67260. E-mail: ; or David J. Harvey, DSc, Target Discovery Institute, Nuffield Department of Medicine, University of Oxford. Roosevelt Drive, Oxford OX3 7FZ, United Kingdom. E-mail:
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Riccetti L, Sperduti S, Lazzaretti C, Klett D, De Pascali F, Paradiso E, Limoncella S, Potì F, Tagliavini S, Trenti T, Galano E, Palmese A, Satwekar A, Daolio J, Nicoli A, Villani MT, Aguzzoli L, Reiter E, Simoni M, Casarini L. Glycosylation Pattern and in vitro Bioactivity of Reference Follitropin alfa and Biosimilars. Front Endocrinol (Lausanne) 2019; 10:503. [PMID: 31396162 PMCID: PMC6667556 DOI: 10.3389/fendo.2019.00503] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 07/11/2019] [Indexed: 12/20/2022] Open
Abstract
Recombinant follicle-stimulating hormone (FSH) (follitropin alfa) and biosimilar preparations are available for clinical use. They have specific FSH activity and a unique glycosylation profile dependent on source cells. The aim of the study is to compare the originator (reference) follitropin alfa (Gonal-f®)- with biosimilar preparations (Bemfola® and Ovaleap®)-induced cellular responses in vitro. Gonadotropin N-glycosylation profiles were analyzed by ELISA lectin assay, revealing preparation specific-patterns of glycan species (Kruskal-Wallis test; p < 0.05, n = 6) and by glycotope mapping. Increasing concentrations of Gonal-f® or biosimilar (1 × 10-3-1 × 103 ng/ml) were used for treating human primary granulosa lutein cells (hGLC) and FSH receptor (FSHR)-transfected HEK293 cells in vitro. Intracellular cAMP production, Ca2+ increase and β-arrestin 2 recruitment were evaluated by BRET, CREB, and ERK1/2 phosphorylation by Western blotting. 12-h gene expression, and 8- and 24-h progesterone and estradiol synthesis were measured by real-time PCR and immunoassay, respectively. We found preparation-specific glycosylation patterns by lectin assay (Kruskal-Wallis test; p < 0.001; n = 6), and similar cAMP production and β-arrestin 2 recruitment in FSHR-transfected HEK293 cells (cAMP EC50 range = 12 ± 0.9-24 ± 1.7 ng/ml; β-arrestin 2 EC50 range = 140 ± 14.1-313 ± 18.7 ng/ml; Kruskal-Wallis test; p ≥ 0.05; n = 4). Kinetics analysis revealed that intracellular Ca2+ increased upon cell treatment by 4 μg/ml Gonal-f®, while equal concentrations of biosimilars failed to induced a response (Kruskal-Wallis test; p < 0.05; n = 3). All preparations induced both 8 and 24 h-progesterone and estradiol synthesis in hGLC, while no different EC50s were demonstrated (Kruskal-Wallis test; p > 0.05; n = 5). Apart from preparation-specific intracellular Ca2+ increases achieved at supra-physiological hormone doses, all compounds induced similar intracellular responses and steroidogenesis, reflecting similar bioactivity, and overall structural homogeneity.
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Affiliation(s)
- Laura Riccetti
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Samantha Sperduti
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Clara Lazzaretti
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
- International PhD School in Clinical and Experimental Medicine, University of Modena and Reggio Emilia, Modena, Italy
| | - Danièle Klett
- PRC, INRA, CNRS, IFCE, Université de Tours, Nouzilly, France
| | | | - Elia Paradiso
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
- International PhD School in Clinical and Experimental Medicine, University of Modena and Reggio Emilia, Modena, Italy
| | - Silvia Limoncella
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Francesco Potì
- Unit of Neurosciences, Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Simonetta Tagliavini
- Department of Laboratory Medicine and Pathological Anatomy, Azienda USL, NOCSAE, Modena, Italy
| | - Tommaso Trenti
- Department of Laboratory Medicine and Pathological Anatomy, Azienda USL, NOCSAE, Modena, Italy
| | - Eugenio Galano
- Analytical Development Biotech Products, Merck Serono S.p.A. (an affiliate of Merck KGaA, Darmstadt, Germany), Rome, Italy
| | - Angelo Palmese
- Analytical Development Biotech Products, Merck Serono S.p.A. (an affiliate of Merck KGaA, Darmstadt, Germany), Rome, Italy
| | - Abhijeet Satwekar
- Analytical Development Biotech Products, Merck Serono S.p.A. (an affiliate of Merck KGaA, Darmstadt, Germany), Rome, Italy
| | - Jessica Daolio
- Azienda Unità Sanitaria Locale—IRCCS di Reggio Emilia, Department of Obstetrics and Gynaecology, Fertility Center, ASMN, Reggio Emilia, Italy
| | - Alessia Nicoli
- Azienda Unità Sanitaria Locale—IRCCS di Reggio Emilia, Department of Obstetrics and Gynaecology, Fertility Center, ASMN, Reggio Emilia, Italy
| | - Maria Teresa Villani
- Azienda Unità Sanitaria Locale—IRCCS di Reggio Emilia, Department of Obstetrics and Gynaecology, Fertility Center, ASMN, Reggio Emilia, Italy
| | - Lorenzo Aguzzoli
- Azienda Unità Sanitaria Locale—IRCCS di Reggio Emilia, Department of Obstetrics and Gynaecology, Fertility Center, ASMN, Reggio Emilia, Italy
| | - Eric Reiter
- PRC, INRA, CNRS, IFCE, Université de Tours, Nouzilly, France
| | - Manuela Simoni
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
- PRC, INRA, CNRS, IFCE, Université de Tours, Nouzilly, France
- Center for Genomic Research, University of Modena and Reggio Emilia, Modena, Italy
- Unit of Endocrinology, Department of Medical Specialties, Azienda Ospedaliero-Universitaria, Modena, Italy
| | - Livio Casarini
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
- Center for Genomic Research, University of Modena and Reggio Emilia, Modena, Italy
- *Correspondence: Livio Casarini
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Landomiel F, De Pascali F, Raynaud P, Jean-Alphonse F, Yvinec R, Pellissier LP, Bozon V, Bruneau G, Crépieux P, Poupon A, Reiter E. Biased Signaling and Allosteric Modulation at the FSHR. Front Endocrinol (Lausanne) 2019; 10:148. [PMID: 30930853 PMCID: PMC6425863 DOI: 10.3389/fendo.2019.00148] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 02/19/2019] [Indexed: 12/12/2022] Open
Abstract
Knowledge on G protein-coupled receptor (GPCRs) structure and mechanism of activation has profoundly evolved over the past years. The way drugs targeting this family of receptors are discovered and used has also changed. Ligands appear to bind a growing number of GPCRs in a competitive or allosteric manner to elicit balanced signaling or biased signaling (i.e., differential efficacy in activating or inhibiting selective signaling pathway(s) compared to the reference ligand). These novel concepts and developments transform our understanding of the follicle-stimulating hormone (FSH) receptor (FSHR) biology and the way it could be pharmacologically modulated in the future. The FSHR is expressed in somatic cells of the gonads and plays a major role in reproduction. When compared to classical GPCRs, the FSHR exhibits intrinsic peculiarities, such as a very large NH2-terminal extracellular domain that binds a naturally heterogeneous, large heterodimeric glycoprotein, namely FSH. Once activated, the FSHR couples to Gαs and, in some instances, to other Gα subunits. G protein-coupled receptor kinases and β-arrestins are also recruited to this receptor and account for its desensitization, trafficking, and intracellular signaling. Different classes of pharmacological tools capable of biasing FSHR signaling have been reported and open promising prospects both in basic research and for therapeutic applications. Here we provide an updated review of the most salient peculiarities of FSHR signaling and its selective modulation.
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Abstract
BACKGROUND The natural ovarian stimulation is mediated by four gonadotrophin glycoforms: FSHtri with three, FSHtetra with four, LHdi with two, and LHtri with three N-glycans. The aim of the study was to determine the serum concentrations of the four glycoforms and their contents of anionic monosaccharides (AMS), i.e. sialic acid (SA) and sulfonated N-acetylgalactosamine (SU) residues throughout the menstrual cycle. METHODS Serum samples were collected from 78 healthy women with regular menstrual cycles. The serum glycoform molecules were identified by their distributions at electrophoreses. Analyses were also performed after removal of terminal SA. The hormones were measured with time-resolved sandwich fluoroimmunoassays. RESULTS The concentration profiles of the four glycoforms were markedly different. FSHtri, which had a 3-fold higher biopotency than FSHtetra, had peak levels on cycle day 5 and at midcycle and nadirs on cycle days 9 and 21-23. FSHtetra had a raised level on cycle days 5-12, followed by a decrease. LHdi and LHtri had similar patterns, but the peak/nadir ratio was much more pronounced for LHdi than for LHtri, 18 versus 4. The numbers of SA residues per molecule were at a maximum around midcycle when the corresponding numbers of SU were at a minimum. The SU/SA ratio was at a minimum on cycle day 12. CONCLUSION The results indicate that the LHdi and the FSHtri molecules play major roles in the natural ovarian stimulation. The SU/SA ratios per molecule favoured a prolonged circulatory half-life of all glycoforms at the midcycle phase. The observations may lead to more successful inductions of ovulation in anovulatory women.
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Affiliation(s)
- Leif Wide
- CONTACT Leif Wide Department of Clinical Chemistry, University Hospital, SE 751 85 Uppsala, Sweden
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11
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Gilbert SB, Roof AK, Rajendra Kumar T. Mouse models for the analysis of gonadotropin secretion and action. Best Pract Res Clin Endocrinol Metab 2018; 32:219-239. [PMID: 29779578 PMCID: PMC5973545 DOI: 10.1016/j.beem.2018.03.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Gonadotropins are pituitary gonadotrope-derived glycoprotein hormones. They act by binding to G-protein coupled receptors on gonads. Gonadotropins play critical roles in reproduction by regulating both gametogenesis and steroidogenesis. Although biochemical and physiological studies provided a wealth of knowledge, gene manipulation techniques using novel mouse models gave new insights into gonadotropin synthesis, secretion and action. Both gain of function and loss of function mouse models for understanding gonadotropin action in a whole animal context have already been generated. Moreover, recent studies on gonadotropin actions in non-gonadal tissues challenged the central dogma of classical gonadotropin actions in gonads and revealed new signaling pathways in these non-gonadal tissues. In this Chapter, we have discussed our current understanding of gonadotropin synthesis, secretion and action using a variety of genetically engineered mouse models.
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Affiliation(s)
- Sara Babcock Gilbert
- Division of Reproductive Endocrinology and Infertility, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA; Division of Reproductive Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA; Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Allyson K Roof
- Division of Reproductive Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA; Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - T Rajendra Kumar
- Division of Reproductive Endocrinology and Infertility, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA; Division of Reproductive Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA; Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA.
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12
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Das N, Kumar TR. Molecular regulation of follicle-stimulating hormone synthesis, secretion and action. J Mol Endocrinol 2018; 60:R131-R155. [PMID: 29437880 PMCID: PMC5851872 DOI: 10.1530/jme-17-0308] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 02/07/2018] [Indexed: 12/11/2022]
Abstract
Follicle-stimulating hormone (FSH) plays fundamental roles in male and female fertility. FSH is a heterodimeric glycoprotein expressed by gonadotrophs in the anterior pituitary. The hormone-specific FSHβ-subunit is non-covalently associated with the common α-subunit that is also present in the luteinizing hormone (LH), another gonadotrophic hormone secreted by gonadotrophs and thyroid-stimulating hormone (TSH) secreted by thyrotrophs. Several decades of research led to the purification, structural characterization and physiological regulation of FSH in a variety of species including humans. With the advent of molecular tools, availability of immortalized gonadotroph cell lines and genetically modified mouse models, our knowledge on molecular mechanisms of FSH regulation has tremendously expanded. Several key players that regulate FSH synthesis, sorting, secretion and action in gonads and extragonadal tissues have been identified in a physiological setting. Novel post-transcriptional and post-translational regulatory mechanisms have also been identified that provide additional layers of regulation mediating FSH homeostasis. Recombinant human FSH analogs hold promise for a variety of clinical applications, whereas blocking antibodies against FSH may prove efficacious for preventing age-dependent bone loss and adiposity. It is anticipated that several exciting new discoveries uncovering all aspects of FSH biology will soon be forthcoming.
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Affiliation(s)
- Nandana Das
- Division of Reproductive Sciences, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, U.S.A
| | - T. Rajendra Kumar
- Division of Reproductive Sciences, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, U.S.A
- Division of Reproductive Endocrinology and Infertility, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, U.S.A
- Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, U.S.A
- Author for Correspondence: T. Rajendra Kumar, PhD, Edgar L. and Patricia M. Makowski Professor, Associate Vice-Chair of Research, Department of Obstetrics & Gynecology, University of Colorado Anschutz Medical Campus, Mail Stop 8613, Research Complex 2, Room # 15-3000B, 12700 E. 19th Avenue, Aurora, CO 80045, USA, Tel: 303-724-8689,
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Sayers N, Hanyaloglu AC. Intracellular Follicle-Stimulating Hormone Receptor Trafficking and Signaling. Front Endocrinol (Lausanne) 2018; 9:653. [PMID: 30450081 PMCID: PMC6225286 DOI: 10.3389/fendo.2018.00653] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 10/17/2018] [Indexed: 12/18/2022] Open
Abstract
Models of G protein-coupled receptor (GPCR) signaling have dramatically altered over the past two decades. Indeed, GPCRs such as the follicle-stimulating hormone receptor (FSHR) have contributed to these new emerging models. We now understand that receptor signaling is highly organized at a spatial level, whereby signaling not only occurs from the plasma membrane but distinct intracellular compartments. Recent studies in the role of membrane trafficking and spatial organization of GPCR signaling in regulating gonadotropin hormone receptor activity has identified novel intracellular compartments, which are tightly linked with receptor signaling and reciprocally regulated by the cellular trafficking machinery. Understanding the impact of these cell biological mechanisms to physiology and pathophysiology is emerging for certain GPCRs. However, for FSHR, the potential impact in both health and disease and the therapeutic possibilities of these newly identified systems is currently unknown, but offers the potential to reassess prior strategies, or unveil novel opportunities, in targeting this receptor.
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Bousfield GR, May JV, Davis JS, Dias JA, Kumar TR. In Vivo and In Vitro Impact of Carbohydrate Variation on Human Follicle-Stimulating Hormone Function. Front Endocrinol (Lausanne) 2018; 9:216. [PMID: 29867757 PMCID: PMC5960776 DOI: 10.3389/fendo.2018.00216] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 04/17/2018] [Indexed: 12/11/2022] Open
Abstract
Human follicle-stimulating hormone (FSH) exhibits both macro- and microheterogeneity in its carbohydrate moieties. Macroheterogeneity results in three physiologically relevant FSHβ subunit variants, two that possess a single N-linked glycan at either one of the two βL1 loop glycosylation sites or one with both glycans. Microheterogeneity is characterized by 80 to over 100 unique oligosaccharide structures attached to each of the 3 to 4 occupied N-glycosylation sites. With respect to its receptor, partially glycosylated (hypo-glycosylated) FSH variants exhibit higher association rates, greater apparent affinity, and greater occupancy than fully glycosylated FSH. Higher receptor binding-activity is reflected by greater in vitro bioactivity and, in some cases, greater in vivo bioactivity. Partially glycosylated pituitary FSH shows an age-related decline in abundance that may be associated with decreased fertility. In this review, we describe an integrated approach involving genetic models, in vitro signaling studies, FSH biochemistry, relevance of physiological changes in FSH glycoform abundance, and characterize the impact of FSH macroheterogeneity on fertility and reproductive aging. We will also address the controversy with regard to claims of a direct action of FSH in mediating bone loss especially at the peri- and postmenopausal stages.
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Affiliation(s)
- George R. Bousfield
- Department of Biological Sciences, Wichita State University, Wichita, KS, United States
- *Correspondence: George R. Bousfield,
| | - Jeffrey V. May
- Department of Biological Sciences, Wichita State University, Wichita, KS, United States
| | - John S. Davis
- Department of Obstetrics and Gynecology, University of Nebraska Medical Center, Omaha, NE, United States
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, United States
- Nebraska-Western Iowa Health Care System, Omaha, NE, United States
| | - James A. Dias
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, NY, United States
| | - T. Rajendra Kumar
- Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
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Wide L, Eriksson K. Molecular size and charge as dimensions to identify and characterize circulating glycoforms of human FSH, LH and TSH. Ups J Med Sci 2017; 122:217-223. [PMID: 29299972 PMCID: PMC5810225 DOI: 10.1080/03009734.2017.1412373] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/29/2022] Open
Abstract
BACKGROUND FSH, LH, and TSH are glycoprotein hormones secreted from the pituitary as fully and low-asparagine-glycosylated hormones. These glycoforms of the hormones exist as a large number of isoforms varying in their glycan contents of terminal anionic monosaccharides (AMS), i.e. sialic acid (SA) and sulfonated N-acetylgalactosamine (SU). Due to the immense heterogeneity and the low concentrations in serum it has been a challenge to develop reliable analytical methods to measure and characterize the circulating glycoforms of these hormones. METHODS The hormones were separated with respect to AMS content per molecule by calibrated 0.1% agarose suspension electrophoreses. Glycoforms in separated fractions were then analyzed with respect to size by 180 calibrated Sephadex G-100 gel filtrations. The hormones were measured with time-resolved sandwich fluoroimmunoassays. All separations and assays were performed in veronal buffer at pH 8.7. Sera and fractions were also analyzed after removal of terminal SA. RESULTS In addition to the fully glycosylated FSH, LH, and TSH, also tri-glycosylated FSH and di-glycosylated LH and TSH forms could be identified in serum samples. The low- and fully glycosylated hormones differed both with respect to size and to median number of AMS per molecule. Algorithms, based on the distributions by electrophoreses, were developed for each hormone to estimate percent low-glycosylated forms in serum. The median numbers of SA and SU per glycoform molecule were estimated using results obtained after desialylation. CONCLUSION The methods can be used for identification and characterization of glycoforms of circulating FSH, LH, and TSH in physiological and clinical studies.
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Affiliation(s)
- Leif Wide
- CONTACT Leif Wide Department of Clinical Chemistry, University Hospital, Uppsala University, SE 751 85 Uppsala, Sweden
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16
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Mastrangeli R, Satwekar A, Cutillo F, Ciampolillo C, Palinsky W, Longobardi S. In-vivo biological activity and glycosylation analysis of a biosimilar recombinant human follicle-stimulating hormone product (Bemfola) compared with its reference medicinal product (GONAL-f). PLoS One 2017; 12:e0184139. [PMID: 28880909 PMCID: PMC5589168 DOI: 10.1371/journal.pone.0184139] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2016] [Accepted: 08/18/2017] [Indexed: 02/03/2023] Open
Abstract
Recombinant human follicle-stimulating hormone (r-hFSH) is widely used in fertility treatment. Although biosimilar versions of r-hFSH (follitropin alfa) are currently on the market, given their structural complexity and manufacturing process, it is important to thoroughly evaluate them in comparison with the reference product. This evaluation should focus on how they differ (e.g., active component molecular characteristics, impurities and potency), as this could be associated with clinical outcome. This study compared the site-specific glycosylation profile and batch-to-batch variability of the in-vivo bioactivity of Bemfola, a biosimilar follitropin alfa, with its reference medicinal product GONAL-f. The focus of this analysis was the site-specific glycosylation at asparagine (Asn) 52 of the α-subunit of FSH, owing to the pivotal role of Asn52 glycosylation in FSH receptor (FSHR) activation/signalling. Overall, Bemfola had bulkier glycan structures and greater sialylation than GONAL-f. The nominal specific activity for both Bemfola and GONAL-f is 13,636 IU/mg. Taking into account both the determined potency and the nominal amount the average specific activity of Bemfola was 14,522 IU/mg (105.6% of the nominal value), which was greater than the average specific activity observed for GONAL-f (13,159 IU/mg; 97.3% of the nominal value; p = 0.0048), although this was within the range stated in the product label. A higher batch-to-batch variability was also observed for Bemfola versus GONAL-f (coefficient of variation: 8.3% vs 5.8%). A different glycan profile was observed at Asn52 in Bemfola compared with GONAL-f (a lower proportion of bi-antennary structures [~53% vs ~77%], and a higher proportion of tri-antennary [~41% vs ~23%] and tetra-antennary structures [~5% vs <1%]). These differences in the Asn52 glycan profile might potentially lead to differences in FSHR activation. This, together with the greater bioactivity and higher batch-to-batch variability of Bemfola, could partly explain the reported differences in clinical outcomes. The clinical relevance of the differences observed between GONAL-f and Bemfola should be further investigated.
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Affiliation(s)
- Renato Mastrangeli
- Biotech Development Programme, Merck Serono S.p.A. (an affiliate of Merck KGaA, Darmstadt, Germany), Guidonia Montecelio, Rome, Italy
- * E-mail:
| | - Abhijeet Satwekar
- Pharamceutical & Analytical Development Biotech Products, Merck Serono S.p.A. (an affiliate of Merck KGaA, Darmstadt, Germany), Guidonia Montecelio, Rome, Italy
| | - Francesca Cutillo
- Pharamceutical & Analytical Development Biotech Products, Merck Serono S.p.A. (an affiliate of Merck KGaA, Darmstadt, Germany), Guidonia Montecelio, Rome, Italy
| | - Cinzia Ciampolillo
- Analytical BQC, Merck RBM S.p.A. (an affiliate of Merck KGaA, Darmstadt, Germany), Ivrea, Turin, Italy
| | - Wolf Palinsky
- Biotech Development Programme, Merck Biopharma (an affiliate of Merck KGaA, Darmstadt, Germany), Aubonne, Switzerland
| | - Salvatore Longobardi
- Global Medical Affairs Fertility, Merck Serono S.p.A. (an affiliate of Merck KGaA, Darmstadt, Germany), Guidonia Montecelio, Rome, Italy
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Wang H, Butnev V, Bousfield GR, Kumar TR. A human FSHB transgene encoding the double N-glycosylation mutant (Asn(7Δ) Asn(24Δ)) FSHβ subunit fails to rescue Fshb null mice. Mol Cell Endocrinol 2016; 426:113-24. [PMID: 26911932 PMCID: PMC5130991 DOI: 10.1016/j.mce.2016.02.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 02/13/2016] [Accepted: 02/16/2016] [Indexed: 10/22/2022]
Abstract
Follicle-stimulating hormone (FSH) is a gonadotrope-derived heterodimeric glycoprotein. Both the common α- and hormone-specific β subunits contain Asn-linked N-glycan chains. Recently, macroheterogeneous FSH glycoforms consisting of β-subunits that differ in N-glycan number were identified in pituitaries of several species and subsequently the recombinant human FSH glycoforms biochemically characterized. Although chemical modification and in vitro site-directed mutagenesis studies defined the roles of N-glycans on gonadotropin subunits, in vivo functional analyses in a whole-animal setting are lacking. Here, we have generated transgenic mice with gonadotrope-specific expression of either an HFSHB(WT) transgene that encodes human FSHβ WT subunit or an HFSHB(dgc) transgene that encodes a human FSHβ(Asn7Δ 24Δ) double N-glycosylation site mutant subunit, and separately introduced these transgenes onto Fshb null background using a genetic rescue strategy. We demonstrate that the human FSHβ(Asn7Δ 24Δ) double N-glycosylation site mutant subunit, unlike human FSHβ WT subunit, inefficiently combines with the mouse α-subunit in pituitaries of Fshb null mice. FSH dimer containing this mutant FSHβ subunit is inefficiently secreted with very low levels detectable in serum. Fshb null male mice expressing HFSHB(dgc) transgene are fertile and exhibit testis tubule size and sperm number similar to those of Fshb null mice. Fshb null female mice expressing the mutant, but not WT human FSHβ subunit-containing FSH dimer are infertile, demonstrate no evidence of estrus cycles, and many of the FSH-responsive genes remain suppressed in their ovaries. Thus, HFSHB(dgc) unlike HFSHB(WT) transgene does not rescue Fshb null mice. Our genetic approach provides direct in vivo evidence that N-linked glycans on FSHβ subunit are essential for its efficient assembly with the α-subunit to form FSH heterodimer in pituitary. Our studies also reveal that N-glycans on FSHβ subunit are essential for FSH secretion and FSH in vivo bioactivity to regulate gonadal growth and physiology.
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Affiliation(s)
- Huizhen Wang
- Department of Molecular and Integrative Physiology
| | - Vladimir Butnev
- Department of Biological Sciences, Wichita State University, Wichita, KS 67260, USA
| | - George R Bousfield
- Department of Biological Sciences, Wichita State University, Wichita, KS 67260, USA
| | - T Rajendra Kumar
- Department of Molecular and Integrative Physiology; Center for Reproductive Sciences, Institute for Reproductive Health and Regenerative Medicine; Department of Pathology and Laboratory Medicine; Department of Neurosurgery, University of Kansas Medical Center, Kansas City, KS 66160, USA.
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Wang H, Chen X, Zhang X, Zhang W, Li Y, Yin H, Shao H, Chen G. Comparative Assessment of Glycosylation of a Recombinant Human FSH and a Highly Purified FSH Extracted from Human Urine. J Proteome Res 2016; 15:923-32. [DOI: 10.1021/acs.jproteome.5b00921] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hong Wang
- Shanghai Institute for Food and Drug Control, Shanghai 201203, China
| | - Xi Chen
- Waters Corporation, Shanghai 201206, China
| | - Xiaoxi Zhang
- Thermo Fisher Scientific, Shanghai 201206, China
| | - Wei Zhang
- Thermo Fisher Scientific, Shanghai 201206, China
| | - Yan Li
- Shanghai Techwell Biopharmaceutical Corporation, Shanghai 201108, China
| | - Hongrui Yin
- Shanghai Institute for Food and Drug Control, Shanghai 201203, China
| | - Hong Shao
- Shanghai Institute for Food and Drug Control, Shanghai 201203, China
| | - Gang Chen
- Shanghai Institute for Food and Drug Control, Shanghai 201203, China
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Meher BR, Dixit A, Bousfield GR, Lushington GH. Glycosylation Effects on FSH-FSHR Interaction Dynamics: A Case Study of Different FSH Glycoforms by Molecular Dynamics Simulations. PLoS One 2015; 10:e0137897. [PMID: 26402790 PMCID: PMC4581761 DOI: 10.1371/journal.pone.0137897] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 08/23/2015] [Indexed: 12/20/2022] Open
Abstract
The gonadotropin known as follicle-stimulating hormone (FSH) plays a key role in regulating reproductive processes. Physiologically active FSH is a glycoprotein that can accommodate glycans on up to four asparagine residues, including two sites in the FSHα subunit that are critical for biochemical function, plus two sites in the β subunit, whose differential glycosylation states appear to correspond to physiologically distinct functions. Some degree of FSHβ hypo-glycosylation seems to confer advantages toward reproductive fertility of child-bearing females. In order to identify possible mechanistic underpinnings for this physiological difference we have pursued computationally intensive molecular dynamics simulations on complexes between the high affinity site of the gonadal FSH receptor (FSHR) and several FSH glycoforms including fully-glycosylated (FSH24), hypo-glycosylated (e.g., FSH15), and completely deglycosylated FSH (dgFSH). These simulations suggest that deviations in FSH/FSHR binding profile as a function of glycosylation state are modest when FSH is adorned with only small glycans, such as single N-acetylglucosamine residues. However, substantial qualitative differences emerge between FSH15 and FSH24 when FSH is decorated with a much larger, tetra-antennary glycan. Specifically, the FSHR complex with hypo-glycosylated FSH15 is observed to undergo a significant conformational shift after 5-10 ns of simulation, indicating that FSH15 has greater conformational flexibility than FSH24 which may explain the more favorable FSH15 kinetic profile. FSH15 also exhibits a stronger binding free energy, due in large part to formation of closer and more persistent salt-bridges with FSHR.
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Affiliation(s)
- Biswa Ranjan Meher
- Bioinformatics Core Facility, University of Kansas, Lawrence, Kansas, United States of America
- * E-mail: (BRM); (GHL)
| | - Anshuman Dixit
- Institute of Life Sciences, Nalco Square, Bhubaneswar, 751023, Odisha, India
| | - George R. Bousfield
- Department of Biological Sciences, Wichita State University, Wichita, Kansas, United States of America
| | - Gerald H. Lushington
- LiS Consulting, Lawrence, Kansas, United States of America
- * E-mail: (BRM); (GHL)
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Jiang C, Hou X, Wang C, May JV, Butnev VY, Bousfield GR, Davis JS. Hypoglycosylated hFSH Has Greater Bioactivity Than Fully Glycosylated Recombinant hFSH in Human Granulosa Cells. J Clin Endocrinol Metab 2015; 100:E852-60. [PMID: 25915568 PMCID: PMC4454802 DOI: 10.1210/jc.2015-1317] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
CONTEXT Previous studies suggest that aging in women is associated with a reduction in hypoglycosylated forms of FSH. OBJECTIVE Experiments were performed to determine whether glycosylation of the FSHβ subunit modulates the biological activity of FSH in human granulosa cells. DESIGN AND SETTING Recombinant human FSH (hFSH) derived from GH3 pituitary cells was purified into fractions containing hypoglycosylated hFSH(21/18) and fully glycosylated hFSH(24). The response to FSH glycoforms was evaluated using the well-characterized, FSH-responsive human granulosa cell line, KGN at an academic medical center. INTERVENTIONS Granulosa cells were treated with increasing concentrations of fully- or hypoglycosylated FSH glycoforms for periods up to 48 hours. MAIN OUTCOME MEASURE(S) The main outcomes were indices of cAMP-dependent cell signaling and estrogen and progesterone synthesis. RESULTS We observed that hypoglycosylated FSH(21/18) was significantly more effective than fully glycosylated FSH(24) at stimulating cAMP accumulation, protein kinase A (PKA) activity, and cAMP response element binding protein (CREB) (S133) phosphorylation. FSH(21/18) was also much more effective than hFSH(24) on the stimulation CREB-response element-mediated transcription, expression of aromatase and STAR proteins, and synthesis of estrogen and progesterone. Adenoviral-mediated expression of the endogenous inhibitor of PKA, inhibited FSH(21/18)- and FSH(24)-stimulated CREB phosphorylation, and steroidogenesis. CONCLUSIONS Hypoglycosylated FSH(21/18) has greater bioactivity than fully glycosylated hFSH(24), suggesting that age-dependent decreases in hypoglycosylated hFSH contribute to reduced ovarian responsiveness. Hypoglycosylated FSH may be useful in follicle stimulation protocols for older patients using assisted reproduction technologies.
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Affiliation(s)
- Chao Jiang
- The Olson Center for Women's Health, Department of Obstetrics and Gynecology (C.J., X.H., C.W., J.S.D.), University of Nebraska Medical Center, Omaha, Nebraska 68198; Nebraska-Northwest Iowa VA Medical Center (X.H., J.S.D.), Omaha, Nebraska 68105; Department of Biological Sciences (J.V.M., V.Y.B., G.R.B.), Wichita State University, Wichita, Kansas 67260; and Department of Biochemistry and Molecular Biology (J.S.D.), University of Nebraska Medical Center, Omaha, Nebraska 68198
| | - Xiaoying Hou
- The Olson Center for Women's Health, Department of Obstetrics and Gynecology (C.J., X.H., C.W., J.S.D.), University of Nebraska Medical Center, Omaha, Nebraska 68198; Nebraska-Northwest Iowa VA Medical Center (X.H., J.S.D.), Omaha, Nebraska 68105; Department of Biological Sciences (J.V.M., V.Y.B., G.R.B.), Wichita State University, Wichita, Kansas 67260; and Department of Biochemistry and Molecular Biology (J.S.D.), University of Nebraska Medical Center, Omaha, Nebraska 68198
| | - Cheng Wang
- The Olson Center for Women's Health, Department of Obstetrics and Gynecology (C.J., X.H., C.W., J.S.D.), University of Nebraska Medical Center, Omaha, Nebraska 68198; Nebraska-Northwest Iowa VA Medical Center (X.H., J.S.D.), Omaha, Nebraska 68105; Department of Biological Sciences (J.V.M., V.Y.B., G.R.B.), Wichita State University, Wichita, Kansas 67260; and Department of Biochemistry and Molecular Biology (J.S.D.), University of Nebraska Medical Center, Omaha, Nebraska 68198
| | - Jeffrey V May
- The Olson Center for Women's Health, Department of Obstetrics and Gynecology (C.J., X.H., C.W., J.S.D.), University of Nebraska Medical Center, Omaha, Nebraska 68198; Nebraska-Northwest Iowa VA Medical Center (X.H., J.S.D.), Omaha, Nebraska 68105; Department of Biological Sciences (J.V.M., V.Y.B., G.R.B.), Wichita State University, Wichita, Kansas 67260; and Department of Biochemistry and Molecular Biology (J.S.D.), University of Nebraska Medical Center, Omaha, Nebraska 68198
| | - Viktor Y Butnev
- The Olson Center for Women's Health, Department of Obstetrics and Gynecology (C.J., X.H., C.W., J.S.D.), University of Nebraska Medical Center, Omaha, Nebraska 68198; Nebraska-Northwest Iowa VA Medical Center (X.H., J.S.D.), Omaha, Nebraska 68105; Department of Biological Sciences (J.V.M., V.Y.B., G.R.B.), Wichita State University, Wichita, Kansas 67260; and Department of Biochemistry and Molecular Biology (J.S.D.), University of Nebraska Medical Center, Omaha, Nebraska 68198
| | - George R Bousfield
- The Olson Center for Women's Health, Department of Obstetrics and Gynecology (C.J., X.H., C.W., J.S.D.), University of Nebraska Medical Center, Omaha, Nebraska 68198; Nebraska-Northwest Iowa VA Medical Center (X.H., J.S.D.), Omaha, Nebraska 68105; Department of Biological Sciences (J.V.M., V.Y.B., G.R.B.), Wichita State University, Wichita, Kansas 67260; and Department of Biochemistry and Molecular Biology (J.S.D.), University of Nebraska Medical Center, Omaha, Nebraska 68198
| | - John S Davis
- The Olson Center for Women's Health, Department of Obstetrics and Gynecology (C.J., X.H., C.W., J.S.D.), University of Nebraska Medical Center, Omaha, Nebraska 68198; Nebraska-Northwest Iowa VA Medical Center (X.H., J.S.D.), Omaha, Nebraska 68105; Department of Biological Sciences (J.V.M., V.Y.B., G.R.B.), Wichita State University, Wichita, Kansas 67260; and Department of Biochemistry and Molecular Biology (J.S.D.), University of Nebraska Medical Center, Omaha, Nebraska 68198
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21
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Butnev VY, Butnev VY, May JV, Shuai B, Tran P, White WK, Brown A, Smalter Hall A, Harvey DJ, Bousfield GR. Production, purification, and characterization of recombinant hFSH glycoforms for functional studies. Mol Cell Endocrinol 2015; 405:42-51. [PMID: 25661536 PMCID: PMC4378652 DOI: 10.1016/j.mce.2015.01.026] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 01/16/2015] [Accepted: 01/18/2015] [Indexed: 11/30/2022]
Abstract
Previously, our laboratory demonstrated the existence of a β-subunit glycosylation-deficient human FSH glycoform, hFSH(21). A third variant, hFSH(18), has recently been detected in FSH glycoforms isolated from purified pituitary hLH preparations. Human FSH(21) abundance in individual female pituitaries progressively decreased with increasing age. Hypo-glycosylated glycoform preparations are significantly more active than fully-glycosylated hFSH preparations. The purpose of this study was to produce, purify and chemically characterize both glycoform variants expressed by a mammalian cell line. Recombinant hFSH was expressed in a stable GH3 cell line and isolated from serum-free cell culture medium by sequential, hydrophobic and immunoaffinity chromatography. FSH glycoform fractions were separated by Superdex 75 gel-filtration. Western blot analysis revealed the presence of both hFSH(18) and hFSH(21) glycoforms in the low molecular weight fraction, however, their electrophoretic mobilities differed from those associated with the corresponding pituitary hFSH variants. Edman degradation of FSH(21/18)-derived β-subunit before and after peptide-N-glycanase F digestion confirmed that it possessed a mixture of both mono-glycosylated FSHβ subunits, as both Asn(7) and Asn(24) were partially glycosylated. FSH receptor-binding assays confirmed our previous observations that hFSH(21/18) exhibits greater receptor-binding affinity and occupies more FSH binding sites when compared to fully-glycosylated hFSH(24). Thus, the age-related reduction in hypo-glycosylated hFSH significantly reduces circulating levels of FSH biological activity that may further compromise reproductive function. Taken together, the ability to express and isolate recombinant hFSH glycoforms opens the way to study functional differences between them both in vivo and in vitro.
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Affiliation(s)
- Viktor Y Butnev
- Department of Biological Sciences, Wichita State University, Wichita, KS 67260-0026, USA
| | - Vladimir Y Butnev
- Department of Biological Sciences, Wichita State University, Wichita, KS 67260-0026, USA
| | - Jeffrey V May
- Department of Biological Sciences, Wichita State University, Wichita, KS 67260-0026, USA
| | - Bin Shuai
- Department of Biological Sciences, Wichita State University, Wichita, KS 67260-0026, USA
| | - Patrick Tran
- Department of Biological Sciences, Wichita State University, Wichita, KS 67260-0026, USA
| | - William K White
- Department of Biological Sciences, Wichita State University, Wichita, KS 67260-0026, USA
| | - Alan Brown
- Department of Biological Sciences, Wichita State University, Wichita, KS 67260-0026, USA
| | - Aaron Smalter Hall
- Molecular Graphics and Modeling Laboratory, University of Kansas, Lawrence, KS 66045, USA
| | - David J Harvey
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford 0X1 3QU, UK
| | - George R Bousfield
- Department of Biological Sciences, Wichita State University, Wichita, KS 67260-0026, USA.
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22
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Bousfield GR, Butnev VY, White WK, Hall AS, Harvey DJ. Comparison of Follicle-Stimulating Hormone Glycosylation Microheterogenity by Quantitative Negative Mode Nano-Electrospray Mass Spectrometry of Peptide-N Glycanase-Released Oligosaccharides. ACTA ACUST UNITED AC 2015; 5. [PMID: 25960929 DOI: 10.4172/2153-0637.1000129] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Glycans from six highly purified hFSH preparations were released by peptide-N-glycanase digestion and analyzed by negative mode nano-ESI mass spectrometry before and after neuraminidase digestion. Pituitary glycan structures were mainly high-mannose, di-, tri-, and tetra-antennary, and their abundance largely paralleled that reported by other investigators using different approaches. For most of the FSH preparations, the differences in glycosylation appeared to be restricted to relative abundances of the major glycan families, as defined by their neutral core oligosaccharide structures. Qualitative differences between glycan populations were largely relegated to those species that were lowest in abundance. Significant qualitative differences were noted in two cases. Recombinant GH3-hFSH triantennary glycans appeared to have the third antenna exclusively on the mannose6-branch, in contrast to all pituitary and urinary hFSH triantennary glycans, in which this antenna was exclusively attached to the mannose3-branch. The hypo-glycosylated hFSH preparation isolated from purified hLH was decorated with high mannose glycans that accounted for over 40% of the total in this population. As this preparation was found to be consistently 20-fold more active than hFSH24 in FSH receptor-binding assays, it appears that both macroheterogeneity and microheterogeneity in FSH preparations need to be taken into account.
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Affiliation(s)
- George R Bousfield
- Department of Biological Sciences, Wichita State University, Wichita, KS 67260
| | - Vladimir Y Butnev
- Department of Biological Sciences, Wichita State University, Wichita, KS 67260
| | - William K White
- Department of Biological Sciences, Wichita State University, Wichita, KS 67260
| | - Aaron Smalter Hall
- Molecular Graphics and Modeling Laboratory, University of Kansas, Lawrence, KS 66045
| | - David J Harvey
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
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23
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Bousfield GR, Butnev VY, Butnev VY, Hiromasa Y, Harvey DJ, May JV. Hypo-glycosylated human follicle-stimulating hormone (hFSH(21/18)) is much more active in vitro than fully-glycosylated hFSH (hFSH(24)). Mol Cell Endocrinol 2014; 382:989-97. [PMID: 24291635 PMCID: PMC3908837 DOI: 10.1016/j.mce.2013.11.008] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Accepted: 11/11/2013] [Indexed: 01/31/2023]
Abstract
Hypo-glycosylated hFSH(21/18) (possesses FSHβ(21) and FSHβ(18)bands) was isolated from hLH preparations by immunoaffinity chromatography followed by gel filtration. Fully-glycosylated hFSH(24) was prepared by combining the fully-glycosylated FSHβ(24) variant with hCGα and isolating the heterodimer. The hFSH(21/18) glycoform preparation was significantly smaller than the hFSH(24) preparation and possessed 60% oligomannose glycans, which is unusual for hFSH. Hypo-glycosylated hFSH(21/18) was 9- to 26-fold more active than fully-glycosylated hFSH(24) in FSH radioligand assays. Significantly greater binding of (125)I-hFSH(21/18) tracer than hFSH(24) tracer was observed in all competitive binding assays. In addition, higher binding of hFSH(21/18) was noted in association and saturation binding assays, in which twice as much hFSH(21/18) was bound as hFSH(24). This suggests that more ligand binding sites are available to hFSH(21/18) in FSHR than to hFSH(24). Hypo-glycosylated hFSH(21/18) also bound rat FSHRs more rapidly, exhibiting almost no lag in binding, whereas hFSH(24) specific binding proceeded very slowly for almost the first hour of incubation.
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MESH Headings
- Animals
- Binding Sites
- Binding, Competitive
- Chromatography, Affinity
- Chromatography, Gel
- Follicle Stimulating Hormone, Human/chemistry
- Follicle Stimulating Hormone, Human/isolation & purification
- Follicle Stimulating Hormone, Human/metabolism
- Glycoprotein Hormones, alpha Subunit/chemistry
- Glycoprotein Hormones, alpha Subunit/metabolism
- Glycosylation
- Humans
- Iodine Radioisotopes
- Luteinizing Hormone/chemistry
- Luteinizing Hormone/metabolism
- Mannose/chemistry
- Mannose/metabolism
- Protein Binding
- Protein Multimerization
- Radioligand Assay
- Rats
- Receptors, FSH/chemistry
- Receptors, FSH/metabolism
- Sequence Analysis, Protein
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Affiliation(s)
- George R Bousfield
- Department of Biological Sciences, Wichita State University, Wichita, KS 67260-0026, USA.
| | - Vladimir Y Butnev
- Department of Biological Sciences, Wichita State University, Wichita, KS 67260-0026, USA
| | - Viktor Y Butnev
- Department of Biological Sciences, Wichita State University, Wichita, KS 67260-0026, USA
| | - Yasuaki Hiromasa
- Biotechnology Core Facility, Kansas State University, Manhattan, KS 66506, USA
| | - David J Harvey
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford 0X1 3QU, UK
| | - Jeffrey V May
- Department of Biological Sciences, Wichita State University, Wichita, KS 67260-0026, USA
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24
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Bousfield GR, Butnev VY, Rueda-Santos MA, Brown A, Hall AS, Harvey DJ. Macro- and Micro-heterogeneity in Pituitary and Urinary Follicle-Stimulating Hormone Glycosylation. ACTA ACUST UNITED AC 2014; 4. [PMID: 25722940 DOI: 10.4172/2153-0637.1000125] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
FSH glycosylation macroheterogeneity in pituitary and urinary hFSH samples was evaluated by Western blotting. Microheterogeneity in two highly purified urinary and pituitary hFSH preparations was evaluated by nano-electrospray mass spectrometry of peptide-N-glycanase-released oligosaccharides. An age-related loss of hypo-glycosylated hFSH in individual female pituitaries was indicated by progressively reduced abundance of hFSH21 relative to hFSH24. Urinary hFSH was evaluated as a potentially non-invasive indicator of glycoform abundance, as the only way for pituitary FSH to reach the urine is through the blood. Both highly purified and crude postmenopausal urinary hFSH preparations possessed the same amount of hFSH21 as postmenopausal pituitary gland FSH. Considerable microheterogeneity was encountered in both pituitary and urinary hFSH glycan populations, as 84 pituitary hFSH glycan ions were observed as compared with 68 urinary hFSH glycans. The biggest quantitative differences between the two populations were reduced abundance of bisecting GlcNAc-containing and fucosylated glycans, along with sulfated glycans in the urinary hFSH glycan population. The relative abundance of sialic acid and glycan antenna did not rationalize the retarded electrophoretic mobilities of the urinary hFSHβ21- and α-subunit bands relative to the corresponding pituitary hFSH bands, as the most abundant glycans in the former possessed only 2 more branches and the same sialic content as in the latter. Site-specific glycosylation information will probably be necessary.
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Affiliation(s)
- George R Bousfield
- Department of Biological Sciences, Wichita State University, Wichita, KS 67260
| | - Vladimir Y Butnev
- Department of Biological Sciences, Wichita State University, Wichita, KS 67260
| | | | - Alan Brown
- Department of Biological Sciences, Wichita State University, Wichita, KS 67260
| | - Aaron Smalter Hall
- Molecular Graphics and Modeling Laboratory, University of Kansas, Lawrence, KS 66045
| | - David J Harvey
- Department of Biochemistry, Oxford University, Oxford OX1 3QU, UK
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25
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Davis JS, Kumar TR, May JV, Bousfield GR. Naturally Occurring Follicle-Stimulating Hormone Glycosylation Variants. ACTA ACUST UNITED AC 2014; 4:e117. [PMID: 25893134 PMCID: PMC4398967 DOI: 10.4172/2153-0637.1000e117] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- John S Davis
- VA Nebraska-Western Iowa Health Care System and Olson Center for Women's Health, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - T Rajendra Kumar
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Jeffrey V May
- Department of Biological Sciences, Wichita State University, Wichita, Kansas, USA
| | - George R Bousfield
- Department of Biological Sciences, Wichita State University, Wichita, Kansas, USA
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26
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Wide L, Eriksson K. Dynamic changes in glycosylation and glycan composition of serum FSH and LH during natural ovarian stimulation. Ups J Med Sci 2013; 118:153-64. [PMID: 23527482 PMCID: PMC3713380 DOI: 10.3109/03009734.2013.782081] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Glycosylation and glycan composition are of fundamental importance for the biological properties of FSH and LH. The aim of this study was to determine the glycosylation, sialylation, and sulfonation of serum FSH and LH throughout the normal menstrual cycle. METHODS Serum samples were collected from 79 healthy women with regular menstrual cycles. The mean numbers of anionic monosaccharide (AMS), sialic acid (SA), and sulfonated N-acetylgalactosamine (SU) residues per FSH and LH molecule were estimated for all sera with methods based on electrophoreses, neuraminidase treatments, and fluoroimmunoassays of the gonadotrophins. RESULTS Di-glycosylated glycoforms (FSHdi, LHdi) were detected in serum in addition to tetra-glycosylated FSH (FSHtetra) and tri-glycosylated LH (LHtri). FSHdi exhibited two peaks: one on day 5 to 7 and one, more pronounced, at midcycle. FSHtetra plateaued at a high concentration from day 5 to 15, without a midcycle peak. There were lower concentrations of LHdi than LHtri, except at midcycle when the opposite occurred. The mean numbers of SA and SU residues per molecule of FSH and LH in serum showed four different patterns during the cycle, all with highly significant (P < 0.0001) differences between levels at different phases of the cycle. The pattern of SA residues on FSH was 'M'-shaped, and that of SU on LH 'V'-shaped. CONCLUSION Serum FSH and LH governing the natural ovarian stimulation process exhibited dynamic changes of glycosylation and glycan composition. This new information on the FSH and LH molecular structures may lead to more successful mono-ovulatory treatment regimens for ovulation induction in anovulatory women.
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Affiliation(s)
- Leif Wide
- Department of Medical Sciences, Uppsala University, Clinical Chemistry, University Hospital, SE 751 85 Uppsala, Sweden.
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27
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Abstract
The synthesis and secretion of the gonadotropic hormones involves coordination of signal transduction, gene expression, protein translation, post-translational folding and modification and finally secretion. The production of biologically active gonadotropin thus requires appropriately folded and glycosylated subunits that assemble to form the heterodimeric hormone. Here we overview recent literature on regulation of gonadotropin subunit gene expression and current understanding of the assembly and secretion of biologically active gonadotropic hormones. Finally, we discuss the therapeutic potential of understanding glycosylation function towards designing new forms of gonadotropins based on observations of physiologically relevant parameters such as age related glycosylation changes.
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Affiliation(s)
- George R Bousfield
- Department of Biological Sciences, Wichita State University, Wichita, KS, USA.
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28
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Ulloa-Aguirre A, Zariñán T, Pasapera AM, Casas-González P, Dias JA. Multiple facets of follicle-stimulating hormone receptor function. Endocrine 2007; 32:251-63. [PMID: 18246451 DOI: 10.1007/s12020-008-9041-6] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2007] [Revised: 01/04/2008] [Accepted: 01/14/2008] [Indexed: 10/22/2022]
Abstract
Follicle-stimulating hormone (FSH) is a glycoprotein hormone produced by the anterior pituitary gland. This gonadotropin plays an essential role in reproduction. Its receptor (FSHR) belongs to the superfamily of G protein-coupled receptors (GPCR), specifically the family of rhodopsin-like receptors. Agonist binding to the FSHR triggers the rapid activation of multiple signaling cascades, mainly the cAMP-adenylyl cyclase-protein kinase A cascade, that impact diverse biological effects of FSH in the gonads. As in other G protein-coupled receptors, the several cytoplasmic domains of the FSHR are involved in signal transduction and termination of the FSH signal. Here we summarize some recent information on the signaling cascades activated by FSH as well as on the role of the intracytoplasmic domains of the FSHR in coupling to membrane and cytosolic proteins linked to key biological functions regulated by the FSH-FSHR system.
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Affiliation(s)
- Alfredo Ulloa-Aguirre
- Research Unit in Reproductive Medicine, Hospital de Ginecobstetricia "Luis Castelazo Ayala", Instituto Mexicano del Seguro Social, Apartado Postal 99-065, Unidad Independencia, C.P. 10101 Mexico, D.F., Mexico.
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