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Richard Ivell - One of the best experts on this subject based on the ideXlab platform.

  • physiology and evolution of the INSL3 rxfp2 hormone receptor system in higher vertebrates
    General and Comparative Endocrinology, 2020
    Co-Authors: Richard Ivell, Tetsuya Kohsaka, Waleed Alhujaili, Ravinder Anandivell
    Abstract:

    Although the insulin-like peptide hormone INSL3 and its cognate receptor RXFP2 (relaxin-family peptide receptor 2) have existed throughout chordate evolution, their physiological diversification appears to be linked closely with mammalian emergence and radiation. In contrast, they have been lost in birds and reptiles. Both hormone and receptor are expressed from autosomal genes which have maintained their synteny across vertebrate evolution. Whereas the INSL3 gene comprises only two exons closely linked to the JAK3 gene, RXFP2 is normally encoded by 18 exons. Both genes, however, are subject to alternative splicing to yield a variety of possibly inactive or antagonistic molecules. In mammals, the INSL3-RXFP2 dyad has maintained a probably primitive association with gametogenesis, seen also in fish, whereby INSL3 promotes the survival, growth and differentiation of male germ cells in the testis and follicle development in the ovary. In addition, however, the INSL3/RXFP2 system has adopted a typical 'neohormone' profile, essential for the promotion of internal fertilisation and viviparity; fetal INSL3 is essential for the first phase of testicular descent into a scrotum, and also appears to be associated with male phenotype, in particular horn and skeletal growth. Circulating INSL3 is produced exclusively by the mature testicular Leydig cells in male mammals and acts as a potent biomarker for testis development during fetal and pubertal development as well as in ageing. As such it can be used also to monitor seasonally breeding animals as well as to investigate environmental or lifestyle conditions affecting development. Nevertheless, most information about INSL3 and RXFP2 comes from a very limited selection of species; it will be especially useful to gain further information from a more diverse range of animals, especially those whose evolution has led them to express unusual reproductive phenotypes.

  • insulin like peptide 3 INSL3 is a major regulator of female reproductive physiology
    Human Reproduction Update, 2018
    Co-Authors: Richard Ivell, Ravinder Anandivell
    Abstract:

    BACKGROUND: Insulin-like peptide 3 (INSL3) is a member of the relaxin family of neohormones which has evolved to address specifically mammalian aspects of reproduction related to viviparity and internal fertilization. It was originally identified as a major product of testicular Leydig cells and has proved to be an important biomarker of Leydig cell functional capacity. However, INSL3 is also produced by theca interna cells of growing antral follicles and is secreted into the bloodstream in phases corresponding to the number and health of the follicles. Moreover, gene silencing experiments have shown that INSL3 is essentially required for androstenedione synthesis, which is the major steroid precursor for the granulosa cells of antral follicles to produce oestrogens. Knockout studies in mice confirm that loss of INSL3 or its receptor in females leads to partial infertility, with reduced follicle numbers, ovulations and litter size. Circulating INSL3 concentration corresponds to the reproductive lifespan, beginning with puberty and declining at the menopause, and thus may contribute to the physiology of other organ systems, particularly those relevant for hormone replacement strategies. SEARCH METHODS: A literature review was carried out by exhaustive searching of literature databases (PubMed and Google Scholar) with the search terms INSL3, RLF, Ley-IL and RXFP2. OBJECTIVE AND RATIONALE: We present the first comprehensive review of INSL3 and its specific receptor RXFP2, and their roles in the context of female reproductive physiology. Moreover, we highlight the potential involvement of INSL3 in female reproductive pathology, such as PCOS, its clinical application as a valuable biomarker of reproductive processes, and its potential for therapeutic interventions. OUTCOMES: In the female mammal, INSL3 is largely produced by the theca interna cells of growing antral follicles during the follicular phase of the menstrual (oestrous) cycle. Within the follicle, INSL3 acts via its G-protein-coupled receptor, RXFP2, in an autocrine/paracrine manner to orchestrate and drive the production of the major steroid precursor androstenedione and its conversion by granulosa cells into oestrogens. These in turn create a positive feedback loop promoting the expression of more theca cell INSL3. This is countered by the follicular production of bone morphogenetic proteins and by the LH surge. Thus, the activity of the theca cell INSL3-RXFP2 system effectively determines the production of estradiol within an antral follicle through the follicular phase. INSL3 is also secreted into the circulation where it acts as a valuable biomarker to monitor the growth of antral follicles; it is consequently increased in PCOS and decreased in women with premature ovarian failure (POF). As an endocrine factor, INSL3 may also influence bone metabolism and kidney function. Additionally, INSL3 or its analogues may prove valuable as an adjunct in hormone replacement therapy or to monitor or influence IVF protocols. WIDER IMPLICATIONS: The INSL3-RXFP2 system represents a new regulatory pathway essential for the proper functioning of growing antral follicles. We still know very little about its involvement in pathologies such as PCOS or POF, and its role as a new biomarker of female function needs to be explored more widely to improve diagnosis and treatment of ovarian dysfunction. We need to examine how INSL3 might be used to improve IVF protocols and outcomes. Opportunities should also be investigated in regard to the systemic application of INSL3 as a rejuvenant therapy, with positive effects on bone or kidney function, and possibly also for fertility regulation. Most research to date has involved animal models; this now needs to be extended to include more human studies.

  • cryptorchidism in the orl rat is associated with muscle patterning defects in the fetal gubernaculum and altered hormonal signaling
    Biology of Reproduction, 2014
    Co-Authors: Julia Spencer Barthold, Ravinder Anandivell, Joan Pugarelli, Abigail B Mateson, Suzanne M Mccahan, Alan K. Robbins, Yanping Wang, Richard Ivell, Robert E. Akins
    Abstract:

    Cryptorchidism, or undescended testis, is a common male genital anomaly of unclear etiology. Hormonal stimulation of the developing fetal gubernaculum by testicular androgens and insulin-like 3 (INSL3) is required for testicular descent. In studies of the orl fetal rat, one of several reported strains with inherited cryptorchidism, we studied hormone levels, gene expression in intact and hormone-stimulated gubernaculum, and imaging of the developing cremaster muscle facilitated by a tissue clearing protocol to further characterize development of the orl gubernaculum. Abnormal localization of the inverted gubernaculum was visible soon after birth. In the orl fetus, testicular testosterone, gubernacular androgen-responsive transcript levels, and muscle-specific gene expression were reduced. However, the in vitro transcriptional response of the orl gubernaculum to androgen was largely comparable to wild type (wt). In contrast, increases in serum INSL3, gubernacular INSL3-responsive transcript levels, expression of the INSL3 receptor, Rxfp2, and the response of the orl gubernaculum to INSL3 in vitro all suggest enhanced activation of INSL3/RXFP2 signaling in the orl rat. However, DNA sequence analysis did not identify functional variants in orl INSL3. Finally, combined analysis of the present and previous studies of the orl transcriptome confirmed altered expression of muscle and cellular motility genes, and whole mount imaging revealed aberrant muscle pattern formation in the orl fetal gubernaculum. The nature and prevalence of developmental muscle defects in the orl gubernaculum are consistent with the cryptorchid phenotype in this strain. These data suggest impaired androgen and enhanced INSL3 signaling in the orl fetus accompanied by defective cremaster muscle development.

  • serum levels of insulin like factor 3 anti mullerian hormone inhibin b and testosterone during pubertal transition in healthy boys a longitudinal pilot study
    Reproduction, 2014
    Co-Authors: Marie Lindhardt Johansen, Ravinder Anandivell, Trine Holm Johannsen, Katharina M Main, Annamaria Andersson, Annette Mouritsen, Casper P Hagen, Mikkel G Mieritz, Tue Soeborg, Richard Ivell
    Abstract:

    Insulin-like factor 3 (INSL3) is a promising marker of Leydig cell function with potentially high clinical relevance. Limited data of INSL3 levels in relation to other reproductive hormones in healthy pubertal boys exist. In this study, we aimed to evaluate longitudinal serum changes in INSL3 compared with LH, FSH, testosterone, inhibin B, and anti-Mullerian hormone (AMH) during puberty in healthy boys. Ten boys were included from the longitudinal part of the COPENHAGEN Puberty Study. Pubertal evaluation, including testicular volume, was performed and blood samples were drawn every 6 months for 5 years. Serum concentrations of testosterone were determined by a newly developed LC-MS/MS method, and serum concentrations of INSL3, AMH, inhibin B, FSH, and LH respectively were determined by validated immunoassays. The results showed that serum INSL3 levels increased progressively with increasing age, pubertal onset, and testicular volume. In six of the ten boys, LH increased before the first observed increase in INSL3. In the remaining four boys, the increase in LH and INSL3 was observed at the same examination. The increases in serum concentrations of LH, testosterone, and INSL3 were not parallel or in ordered succession and varied interindividually. We demonstrated that INSL3 concentrations were tightly associated with pubertal onset and increasing testicular volume. However, the pubertal increases in LH, INSL3, and testosterone concentrations were not entirely parallel, suggesting that INSL3 and testosterone may be regulated differently. Thus, we speculate that INSL3 provides additional information on Leydig cell differentiation and function during puberty compared with traditional markers of testicular function.

  • DOI: 10.1093/molehr/gag025 The molecular basis of cryptorchidism*
    2013
    Co-Authors: Richard Ivell, Stefan Hartung
    Abstract:

    Cryptorchidism is the commonest malady to affect newborn male infants. Until recently, the molecular aetiology of this syndrome was unclear. Cryptorchidism may be part of a broader testicular dysgenesis syndrome, wherein a disturbance in steroid hormone metabolism, possibly through a perturbed hypothalamic±pituitary±gonadal axis could be involved. Disturbance may be genetic, or extrinsic through endocrine disruptors. Recently, the role of insulin-like factor-3 (INSL3; alternatively called relaxin-like factor) has been highlighted through the cryptorchid phenotype of mice where genes for either INSL3 or its receptor have been ablated. INSL3 is produced by Leydig cells of the fetal testis and acts upon the gubernacular ligament to retain the gonad in the inguinal region, from which it later passes into the scrotum. INSL3 expression in fetal testis is inhibited by maternal exposure to estrogens. Although to date no mutations have been found in the human INSL3 gene responsible for cryptorchidism, one causative mutation in the INSL3 receptor (LGR8 or GREAT) has been reported. Studies on developmental transcription factors, such as Hoxa-10 in mice, suggest that other speci®c molecular cascades could also lead to a cryptorchid phenotype. Considering its frequency in newborn children, and the severity of the untreated condition (infertility and often testicular cancer) these new ®ndings should generate new information on possible causes and treatments. Key words: cryptorchidism/Hoxa-10/INSL3/RLF/steroids/testicular dysgenesis syndrom

Ravinder Anandivell - One of the best experts on this subject based on the ideXlab platform.

  • physiology and evolution of the INSL3 rxfp2 hormone receptor system in higher vertebrates
    General and Comparative Endocrinology, 2020
    Co-Authors: Richard Ivell, Tetsuya Kohsaka, Waleed Alhujaili, Ravinder Anandivell
    Abstract:

    Although the insulin-like peptide hormone INSL3 and its cognate receptor RXFP2 (relaxin-family peptide receptor 2) have existed throughout chordate evolution, their physiological diversification appears to be linked closely with mammalian emergence and radiation. In contrast, they have been lost in birds and reptiles. Both hormone and receptor are expressed from autosomal genes which have maintained their synteny across vertebrate evolution. Whereas the INSL3 gene comprises only two exons closely linked to the JAK3 gene, RXFP2 is normally encoded by 18 exons. Both genes, however, are subject to alternative splicing to yield a variety of possibly inactive or antagonistic molecules. In mammals, the INSL3-RXFP2 dyad has maintained a probably primitive association with gametogenesis, seen also in fish, whereby INSL3 promotes the survival, growth and differentiation of male germ cells in the testis and follicle development in the ovary. In addition, however, the INSL3/RXFP2 system has adopted a typical 'neohormone' profile, essential for the promotion of internal fertilisation and viviparity; fetal INSL3 is essential for the first phase of testicular descent into a scrotum, and also appears to be associated with male phenotype, in particular horn and skeletal growth. Circulating INSL3 is produced exclusively by the mature testicular Leydig cells in male mammals and acts as a potent biomarker for testis development during fetal and pubertal development as well as in ageing. As such it can be used also to monitor seasonally breeding animals as well as to investigate environmental or lifestyle conditions affecting development. Nevertheless, most information about INSL3 and RXFP2 comes from a very limited selection of species; it will be especially useful to gain further information from a more diverse range of animals, especially those whose evolution has led them to express unusual reproductive phenotypes.

  • insulin like peptide 3 INSL3 is a major regulator of female reproductive physiology
    Human Reproduction Update, 2018
    Co-Authors: Richard Ivell, Ravinder Anandivell
    Abstract:

    BACKGROUND: Insulin-like peptide 3 (INSL3) is a member of the relaxin family of neohormones which has evolved to address specifically mammalian aspects of reproduction related to viviparity and internal fertilization. It was originally identified as a major product of testicular Leydig cells and has proved to be an important biomarker of Leydig cell functional capacity. However, INSL3 is also produced by theca interna cells of growing antral follicles and is secreted into the bloodstream in phases corresponding to the number and health of the follicles. Moreover, gene silencing experiments have shown that INSL3 is essentially required for androstenedione synthesis, which is the major steroid precursor for the granulosa cells of antral follicles to produce oestrogens. Knockout studies in mice confirm that loss of INSL3 or its receptor in females leads to partial infertility, with reduced follicle numbers, ovulations and litter size. Circulating INSL3 concentration corresponds to the reproductive lifespan, beginning with puberty and declining at the menopause, and thus may contribute to the physiology of other organ systems, particularly those relevant for hormone replacement strategies. SEARCH METHODS: A literature review was carried out by exhaustive searching of literature databases (PubMed and Google Scholar) with the search terms INSL3, RLF, Ley-IL and RXFP2. OBJECTIVE AND RATIONALE: We present the first comprehensive review of INSL3 and its specific receptor RXFP2, and their roles in the context of female reproductive physiology. Moreover, we highlight the potential involvement of INSL3 in female reproductive pathology, such as PCOS, its clinical application as a valuable biomarker of reproductive processes, and its potential for therapeutic interventions. OUTCOMES: In the female mammal, INSL3 is largely produced by the theca interna cells of growing antral follicles during the follicular phase of the menstrual (oestrous) cycle. Within the follicle, INSL3 acts via its G-protein-coupled receptor, RXFP2, in an autocrine/paracrine manner to orchestrate and drive the production of the major steroid precursor androstenedione and its conversion by granulosa cells into oestrogens. These in turn create a positive feedback loop promoting the expression of more theca cell INSL3. This is countered by the follicular production of bone morphogenetic proteins and by the LH surge. Thus, the activity of the theca cell INSL3-RXFP2 system effectively determines the production of estradiol within an antral follicle through the follicular phase. INSL3 is also secreted into the circulation where it acts as a valuable biomarker to monitor the growth of antral follicles; it is consequently increased in PCOS and decreased in women with premature ovarian failure (POF). As an endocrine factor, INSL3 may also influence bone metabolism and kidney function. Additionally, INSL3 or its analogues may prove valuable as an adjunct in hormone replacement therapy or to monitor or influence IVF protocols. WIDER IMPLICATIONS: The INSL3-RXFP2 system represents a new regulatory pathway essential for the proper functioning of growing antral follicles. We still know very little about its involvement in pathologies such as PCOS or POF, and its role as a new biomarker of female function needs to be explored more widely to improve diagnosis and treatment of ovarian dysfunction. We need to examine how INSL3 might be used to improve IVF protocols and outcomes. Opportunities should also be investigated in regard to the systemic application of INSL3 as a rejuvenant therapy, with positive effects on bone or kidney function, and possibly also for fertility regulation. Most research to date has involved animal models; this now needs to be extended to include more human studies.

  • cryptorchidism in the orl rat is associated with muscle patterning defects in the fetal gubernaculum and altered hormonal signaling
    Biology of Reproduction, 2014
    Co-Authors: Julia Spencer Barthold, Ravinder Anandivell, Joan Pugarelli, Abigail B Mateson, Suzanne M Mccahan, Alan K. Robbins, Yanping Wang, Richard Ivell, Robert E. Akins
    Abstract:

    Cryptorchidism, or undescended testis, is a common male genital anomaly of unclear etiology. Hormonal stimulation of the developing fetal gubernaculum by testicular androgens and insulin-like 3 (INSL3) is required for testicular descent. In studies of the orl fetal rat, one of several reported strains with inherited cryptorchidism, we studied hormone levels, gene expression in intact and hormone-stimulated gubernaculum, and imaging of the developing cremaster muscle facilitated by a tissue clearing protocol to further characterize development of the orl gubernaculum. Abnormal localization of the inverted gubernaculum was visible soon after birth. In the orl fetus, testicular testosterone, gubernacular androgen-responsive transcript levels, and muscle-specific gene expression were reduced. However, the in vitro transcriptional response of the orl gubernaculum to androgen was largely comparable to wild type (wt). In contrast, increases in serum INSL3, gubernacular INSL3-responsive transcript levels, expression of the INSL3 receptor, Rxfp2, and the response of the orl gubernaculum to INSL3 in vitro all suggest enhanced activation of INSL3/RXFP2 signaling in the orl rat. However, DNA sequence analysis did not identify functional variants in orl INSL3. Finally, combined analysis of the present and previous studies of the orl transcriptome confirmed altered expression of muscle and cellular motility genes, and whole mount imaging revealed aberrant muscle pattern formation in the orl fetal gubernaculum. The nature and prevalence of developmental muscle defects in the orl gubernaculum are consistent with the cryptorchid phenotype in this strain. These data suggest impaired androgen and enhanced INSL3 signaling in the orl fetus accompanied by defective cremaster muscle development.

  • serum levels of insulin like factor 3 anti mullerian hormone inhibin b and testosterone during pubertal transition in healthy boys a longitudinal pilot study
    Reproduction, 2014
    Co-Authors: Marie Lindhardt Johansen, Ravinder Anandivell, Trine Holm Johannsen, Katharina M Main, Annamaria Andersson, Annette Mouritsen, Casper P Hagen, Mikkel G Mieritz, Tue Soeborg, Richard Ivell
    Abstract:

    Insulin-like factor 3 (INSL3) is a promising marker of Leydig cell function with potentially high clinical relevance. Limited data of INSL3 levels in relation to other reproductive hormones in healthy pubertal boys exist. In this study, we aimed to evaluate longitudinal serum changes in INSL3 compared with LH, FSH, testosterone, inhibin B, and anti-Mullerian hormone (AMH) during puberty in healthy boys. Ten boys were included from the longitudinal part of the COPENHAGEN Puberty Study. Pubertal evaluation, including testicular volume, was performed and blood samples were drawn every 6 months for 5 years. Serum concentrations of testosterone were determined by a newly developed LC-MS/MS method, and serum concentrations of INSL3, AMH, inhibin B, FSH, and LH respectively were determined by validated immunoassays. The results showed that serum INSL3 levels increased progressively with increasing age, pubertal onset, and testicular volume. In six of the ten boys, LH increased before the first observed increase in INSL3. In the remaining four boys, the increase in LH and INSL3 was observed at the same examination. The increases in serum concentrations of LH, testosterone, and INSL3 were not parallel or in ordered succession and varied interindividually. We demonstrated that INSL3 concentrations were tightly associated with pubertal onset and increasing testicular volume. However, the pubertal increases in LH, INSL3, and testosterone concentrations were not entirely parallel, suggesting that INSL3 and testosterone may be regulated differently. Thus, we speculate that INSL3 provides additional information on Leydig cell differentiation and function during puberty compared with traditional markers of testicular function.

  • functional link between bone morphogenetic proteins and insulin like peptide 3 signaling in modulating ovarian androgen production
    Proceedings of the National Academy of Sciences of the United States of America, 2013
    Co-Authors: Claire Glister, Ravinder Anandivell, Richard Ivell, Raymond J. Rodgers, Leanne Satchell, Ross A D Bathgate, John D Wade, Yanzhenzhi Dai, P G Knight
    Abstract:

    Bone morphogenetic proteins (BMPs) are firmly implicated as intraovarian regulators of follicle development and steroidogenesis. Here we report a microarray analysis showing that treatment of cultured bovine theca cells (TC) with BMP6 significantly (>twofold; P < 0.01) up- or down-regulated expression of 445 genes. Insulin-like peptide 3 (INSL3)was themost heavily down-regulated gene (−43-fold)with cytochrome P450, subfamily XVII (CYP17A1) and other key steroidogenic transcripts including steroidogenic acute regulatory protein (STAR), cytochrome P450 family 11, subfamily A1 (CYP11A1) and 3 beta-hydroxysteroid dehydrogenase type 1 (HSD3B1) also downregulated. BMP6 also reduced expression of nuclear receptor subfamily 5A1 (NR5A1) known to target the promoter regions of the aforementioned genes. Real-time PCR confirmed these findings and also revealed a marked reduction in expression of INSL3 receptor, relaxin/insulin-like family peptide receptor 2 (RXFP2). Secretion of INSL3 protein and androstenedione were also suppressed suggesting a functional link between BMP and INSL3 pathways in controlling androgen synthesis. RNAi-mediated knockdown of INSL3 reduced INSL3 mRNA (75%) and protein (94%) level and elicited a 77% reduction in CYP17A1 mRNA and 83% reduction in androstenedione secretion. Knockdown of RXFP2 also reduced CYP17A1 expression (81%) and androstenedione secretion (88%). Conversely, treatment with exogenous (human) INSL3 increased androstenedione secretion ∼twofold. The CYP17A1 inhibitor abiraterone abolished androgen secretion and reduced expression of both INSL3 and RXFP2. Collectively, these findings indicate a positive autoregulatory role for INSL3 signaling in maintaining thecal androgen production, and visa versa. Moreover, BMP6-induced suppression of thecal androgen synthesis may be mediated, at least in part, by reduced INSL3-RXFP2 signaling.

Ross A D Bathgate - One of the best experts on this subject based on the ideXlab platform.

  • challenges in the design of insulin and relaxin insulin like peptide mimetics
    Bioorganic & Medicinal Chemistry, 2017
    Co-Authors: Ross A D Bathgate, Mohammed Akhter Hossain
    Abstract:

    Peptidomimetics are designed to overcome the poor pharmacokinetics and pharmacodynamics associated with the native peptide or protein on which they are based. The design of peptidomimetics starts from developing structure-activity relationships of the native ligand-target pair that identify the key residues that are responsible for the biological effect of the native peptide or protein. Then minimization of the structure and introduction of constraints are applied to create the core active site that can interact with the target with high affinity and selectivity. Developing peptidomimetics is not trivial and often challenging, particularly when peptides' interaction mechanism with their target is complex. This review will discuss the challenges of developing peptidomimetics of therapeutically important insulin superfamily peptides, particularly those which have two chains (A and B) and three disulfide bonds and whose receptors are known, namely insulin, H2 relaxin, H3 relaxin, INSL3 and INSL5.

  • relaxin family peptides structure activity relationship studies
    British Journal of Pharmacology, 2017
    Co-Authors: Ross A D Bathgate, John D Wade, Mohammed Akhter Hossain, Johan K Rosengren, Nitin A Patil, Frances Separovic
    Abstract:

    The human relaxin peptide family consists of seven cystine-rich peptides, four of which are known to signal through relaxin family peptide receptors, RXFP1–4. As these peptides play a vital role physiologically and in various diseases, they are of considerable importance for drug discovery and development. Detailed structure–activity relationship (SAR) studies towards understanding the role of important residues in each of these peptides have been reported over the years and utilized for the design of antagonists and minimized agonist variants. This review summarizes the current knowledge of the SAR of human relaxin 2 (H2 relaxin), human relaxin 3 (H3 relaxin), human insulin-like peptide 3 (INSL3) and human insulin-like peptide 5 (INSL5). Linked Articles This article is part of a themed section on Recent Progress in the Understanding of Relaxin Family Peptides and their Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.10/issuetoc

  • international union of basic and clinical pharmacology xcv recent advances in the understanding of the pharmacology and biological roles of relaxin family peptide receptors 1 4 the receptors for relaxin family peptides
    Pharmacological Reviews, 2015
    Co-Authors: Michelle L Halls, Ross A D Bathgate, Steve W Sutton, Thomas Dschietzig, Roger J. Summers
    Abstract:

    Relaxin, insulin-like peptide 3 (INSL3), relaxin-3, and INSL5 are the cognate ligands for the relaxin family peptide (RXFP) receptors 1–4, respectively. RXFP1 activates pleiotropic signaling pathways including the signalosome protein complex that facilitates high-sensitivity signaling; coupling to Gαs, Gαi, and Gαo proteins; interaction with glucocorticoid receptors; and the formation of hetero-oligomers with distinctive pharmacological properties. In addition to relaxin-related ligands, RXFP1 is activated by Clq-tumor necrosis factor-related protein 8 and by small-molecular-weight agonists, such as ML290 [2-isopropoxy-N-(2-(3-(trifluoromethylsulfonyl)phenylcarbamoyl)phenyl)benzamide], that act allosterically. RXFP2 activates only the Gαs- and Gαo-coupled pathways. Relaxin-3 is primarily a neuropeptide, and its cognate receptor RXFP3 is a target for the treatment of depression, anxiety, and autism. A variety of peptide agonists, antagonists, biased agonists, and an allosteric modulator target RXFP3. Both RXFP3 and the related RXFP4 couple to Gαi/Gαo proteins. INSL5 has the properties of an incretin; it is secreted from the gut and is orexigenic. The expression of RXFP4 in gut, adipose tissue, and β-islets together with compromised glucose tolerance in INSL5 or RXFP4 knockout mice suggests a metabolic role. This review focuses on the many advances in our understanding of RXFP receptors in the last 5 years, their signal transduction mechanisms, the development of novel compounds that target RXFP1–4, the challenges facing the field, and current prospects for new therapeutics.

  • functional link between bone morphogenetic proteins and insulin like peptide 3 signaling in modulating ovarian androgen production
    Proceedings of the National Academy of Sciences of the United States of America, 2013
    Co-Authors: Claire Glister, Ravinder Anandivell, Richard Ivell, Raymond J. Rodgers, Leanne Satchell, Ross A D Bathgate, John D Wade, Yanzhenzhi Dai, P G Knight
    Abstract:

    Bone morphogenetic proteins (BMPs) are firmly implicated as intraovarian regulators of follicle development and steroidogenesis. Here we report a microarray analysis showing that treatment of cultured bovine theca cells (TC) with BMP6 significantly (>twofold; P < 0.01) up- or down-regulated expression of 445 genes. Insulin-like peptide 3 (INSL3)was themost heavily down-regulated gene (−43-fold)with cytochrome P450, subfamily XVII (CYP17A1) and other key steroidogenic transcripts including steroidogenic acute regulatory protein (STAR), cytochrome P450 family 11, subfamily A1 (CYP11A1) and 3 beta-hydroxysteroid dehydrogenase type 1 (HSD3B1) also downregulated. BMP6 also reduced expression of nuclear receptor subfamily 5A1 (NR5A1) known to target the promoter regions of the aforementioned genes. Real-time PCR confirmed these findings and also revealed a marked reduction in expression of INSL3 receptor, relaxin/insulin-like family peptide receptor 2 (RXFP2). Secretion of INSL3 protein and androstenedione were also suppressed suggesting a functional link between BMP and INSL3 pathways in controlling androgen synthesis. RNAi-mediated knockdown of INSL3 reduced INSL3 mRNA (75%) and protein (94%) level and elicited a 77% reduction in CYP17A1 mRNA and 83% reduction in androstenedione secretion. Knockdown of RXFP2 also reduced CYP17A1 expression (81%) and androstenedione secretion (88%). Conversely, treatment with exogenous (human) INSL3 increased androstenedione secretion ∼twofold. The CYP17A1 inhibitor abiraterone abolished androgen secretion and reduced expression of both INSL3 and RXFP2. Collectively, these findings indicate a positive autoregulatory role for INSL3 signaling in maintaining thecal androgen production, and visa versa. Moreover, BMP6-induced suppression of thecal androgen synthesis may be mediated, at least in part, by reduced INSL3-RXFP2 signaling.

  • Reviewed by:
    2012
    Co-Authors: Ross A D Bathgate, John D Wade, Johan K Rosengren, Soude Zhang, Richard A. Hughes, Andrzej Marek Brzozowski, Chengcheng Alec Zhang, Florey Neuroscience
    Abstract:

    Insulin-like peptide 3 (INSL3) is a hormone and/or paracrine factor which is a member of the relaxin peptide family. It has key roles as a fertility regulator in both males and females.The receptor for INSL3 is the leucine rich repeat (LRR) containing G-protein coupled receptor 8 (LGR8) which is now known as relaxin family peptide receptor 2 (RXFP2). Receptor activa-tion by INSL3 involves binding to the LRRs in the large ectodomain of RXFP2 by residues within the B-chain of INSL3 as well as an interaction with the transmembrane exoloops of the receptor. Although the binding to the LRRs is well characterized the features of the peptide and receptor involved in the exoloop interaction are currently unknown.This study was designed to determine the key INSL3 determinants for RXFP2 activation. A chimeric peptide approach was first utilized to demonstrate that the A-chain is critical for receptor activation. Replacement of the INSL3A-chainwith that from the related peptides INSL5 and INSL6 resulted in complete loss of activity despite only minor changes in binding affinity. Subsequent replacement of specific A-chain residues with those from the INSL5 peptide highlighted that the N-terminus of theA-chain of INSL3 is critical for its activity. Remarkably, replacement of the entire N-terminus with four or five alanine residues resulted in peptide

Ibrahim M Adham - One of the best experts on this subject based on the ideXlab platform.

  • the overexpression of the INSL3 in female mice causes descent of the ovaries
    Molecular Endocrinology, 2002
    Co-Authors: Ibrahim M Adham, Erika E Bullesbach, Gerd Steding, Tarvo Thamm, Christian Schwabe, Ilona Paprotta, Wolfgang Engel
    Abstract:

    Testicular descent in mice is dependent upon proper outgrowth of the gubernaculum primordia under the influence of the insulin-like 3 gene product (INSL3). Deletion of this gene prevents gubernaculum growth and causes bilateral cryptorchidism. In vitro experiments have led to the suggestion that INSL3 and androgens together induce outgrowth of the gubernacular primordia. The experiments reported here were designed specifically to determine whether in vivo the INSL3-mediated gubernaculum development is independent of androgens. To that effect transgenic male and female mice were generated that overexpressed INSL3 in the pancreas during fetal and postnatal life. Expression of the transgenic allele in the INSL3-deficient mice rescued the cryptorchidism in male mutant, indicating that the islet beta-cells efficiently processed the INSL3 gene product to the functional hormone. All transgenic females displayed bilateral inguinal hernia. The processus vaginalis developed containing intestinal loops. The Mullerian derivatives gave rise to oviduct, uterus, and upper vagina, and Wolffian duct derivatives were missing, indicating the absence of the androgen- and anti-Mullerian hormone-mediated activities in transgenic females. The ovaries descended into a position over the bladder and attached to the abdominal wall via the well developed cranial suspensory ligament and the gubernaculum. Administration of dihydrotestosterone during prenatal development suppressed formation of the cranial suspensory ligament and thereby allowed the descent of the ovaries into the processus vaginalis. These results suggest that INSL3-mediated activity induces gubernaculum development and precludes a role of androgen in this process. Furthermore, the transgenic females exhibit reduced fertility, which is due to fetal mortality during midgestation.

  • increase in final stages of follicular atresia and premature decay of corpora lutea in INSL3 deficient mice
    Molecular Reproduction and Development, 2001
    Co-Authors: Katharina Spanelborowski, Iris Schafer, Wolfgang Engel, Stephan Zimmermann, Ibrahim M Adham
    Abstract:

    The insulin-like factor 3 (INSL3), a member of the insulin-like hormone family, is exclusively synthesized in gonads. Our recent analysis of INSL3-deficient mice revealed the regulating role of the INSL3 factor on the gubernaculum development during the transabdominal descent of the testis. Here we define the role of the INSL3 factor by histometric analysis of wild-type and INSL3−/− ovaries. Ovaries from 40-day-old- and 6-month-old INSL3−/− mice as well as from wild-type littermates were serially sectioned. Sections were stained with periodic acid Schiff reaction (PAS) for counting the number of zonae pellucidae which indicated the final stages of follicular atresia. Corpora lutea were also determined. Some sections were processed using either a modified TUNEL method for in situ detection of apoptosis or a lectin labelling technique with Griffonia simplicifolia I agglutinin (GS I) for endothelial cell occurrence. The number of zonae pellucidae was higher in INSL3-deficient ovaries of both ages than in ovaries of wild-type sisters (P < 0.05 for 40-day-old ovaries; P < 0.01 for 6-month-old ovaries). Additionally, the wild-type mice of both ages possessed threefold more corpora lutea than their INSL3 littermates (P < 0.01 for 40-day-old; P < 0.001 for 6-month-old). In general, wild-type corpora lutea looked healthy, showed GS I-positive endothelial cells and no apoptotic cells. Corpora lutea from mutants were rich in regressing GS I luteal cells, and apoptotic cells appeared. We conclude: Follicular atresia and luteolysis are accelerated in ovaries of INSL3-deficient mice probably because of increased apoptosis. The INSL3 function thus appears to rescue endocrine cells from the apoptotic pathway. Mol. Reprod. Dev. 58:281–286, 2001. © 2001 Wiley-Liss, Inc.

  • increase in final stages of follicular atresia and premature decay of corpora lutea in INSL3 deficient mice
    Molecular Reproduction and Development, 2001
    Co-Authors: Katharina Spanelborowski, Iris Schafer, Wolfgang Engel, Stephan Zimmermann, Ibrahim M Adham
    Abstract:

    The insulin-like factor 3 (INSL3), a member of the insulin-like hormone family, is exclusively synthesized in gonads. Our recent analysis of INSL3-deficient mice revealed the regulating role of the INSL3 factor on the gubernaculum development during the transabdominal descent of the testis. Here we define the role of the INSL3 factor by histometric analysis of wild-type and INSL3(-/-) ovaries. Ovaries from 40-day-old- and 6-month-old INSL3(-/-) mice as well as from wild-type littermates were serially sectioned. Sections were stained with periodic acid Schiff reaction (PAS) for counting the number of zonae pellucidae which indicated the final stages of follicular atresia. Corpora lutea were also determined. Some sections were processed using either a modified TUNEL method for in situ detection of apoptosis or a lectin labelling technique with Griffonia simplicifolia I agglutinin (GS I) for endothelial cell occurrence. The number of zonae pellucidae was higher in INSL3-deficient ovaries of both ages than in ovaries of wild-type sisters (P < 0.05 for 40-day-old ovaries; P < 0.01 for 6-month-old ovaries). Additionally, the wild-type mice of both ages possessed threefold more corpora lutea than their INSL3 littermates (P < 0.01 for 40-day-old; P < 0.001 for 6-month-old). In general, wild-type corpora lutea looked healthy, showed GS I-positive endothelial cells and no apoptotic cells. Corpora lutea from mutants were rich in regressing GS I luteal cells, and apoptotic cells appeared. We conclude: Follicular atresia and luteolysis are accelerated in ovaries of INSL3-deficient mice probably because of increased apoptosis. The INSL3 function thus appears to rescue endocrine cells from the apoptotic pathway.

  • involvement of insulin like factor 3 INSL3 in diethylstilbestrol induced cryptorchidism
    Endocrinology, 2000
    Co-Authors: J M Emmen, Ibrahim M Adham, Wolfgang Engel, Anke Mcluskey, Miriam Verhoefpost, Axel P N Themmen, Anton J Grootegoed, A O Brinkmann
    Abstract:

    Recently, it has been shown that targeted inactivation of the INSL3 gene in male mice results in cryptorchidism. The INSL3 gene encodes insulin-like factor 3 (INSL3), which is expressed in fetal Leydig cells. The testicular factor INSL3 appears to play an important role in the transabdominal phase of testis descent, which involves development of the gubernaculum. Other studies have demonstrated that in utero exposure to diethylstilbestrol (DES), a synthetic estrogen, can lead to cryptorchidism both in humans and in animal models. The present study was undertaken to investigate whether prenatal DES-exposure might interfere with testicular INSL3 mRNA expression. Furthermore, the effect of DES on steroidogenic factor 1 (SF-1) mRNA expression level was determined, since it has been shown that SF-1 plays an essential role in transcriptional activation of the INSL3 gene promoter. Timed pregnant mice were treated with DES (100 μg/kg body weight) or vehicle alone on days E9 (gestational day 9) through E17. Contro...

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  • Protective Role of Testicular Hormone INSL3 From Atrophy and Weakness in Skeletal Muscle.
    Frontiers in endocrinology, 2018
    Co-Authors: Alberto Ferlin, Luca De Toni, Alexander I. Agoulnik, Giorgia Lunardon, Andrea Armani, Sergia Bortolanza, Bert Blaauw, Marco Sandri, Carlo Foresta
    Abstract:

    Androgens are primarily involved in muscle growth, whilst disease-driven muscle wasting is frequently associated with hypogonadism. The Leydig cells of the testes also produce the peptide-hormone Insulin-like peptide 3 (INSL3). INSL3 displays anabolic activity on bone, a target tissue of androgens, and its plasma concentrations are diminished in male hypogonadism. Here we tested the role of INSL3 on muscle mass regulation, in physiological and pathological conditions. Studies on C2C12 cell line showed that INSL3, acting on his specific receptor RXFP2, promotes skeletal muscle protein synthesis through the Akt/mTOR/S6 pathway. Next, studies on Rxfp2-/- mice showed that INSL3 is required to prevent excessive muscle loss after denervation. Mechanistically, denervated Rxfp2-/- mice lacked the compensatory activation of the Akt/mTOR/S6 pathway and showed an abnormal ubiquitin-proteasome system activation. Lack of INSL3 activity resulted also in reduced contractile force. These findings underlie a role of INSL3/RXFP2 in protein turnover, contributing to muscle wasting in male hypogonadism.

  • negative association between sclerostin and INSL3 in isolated human osteocytes and in klinefelter syndrome new hints for testis bone crosstalk
    The Journal of Clinical Endocrinology and Metabolism, 2018
    Co-Authors: Andrea Di Nisio, Alberto Ferlin, Luca De Toni, Maria Santa Rocca, Marco Ghezzi, Riccardo Selice, Giuseppe Taglialavoro, Carlo Foresta
    Abstract:

    Context The regulation of bone mass by the testis is a well-recognized mechanism, but the role of Leydig-specific marker insulin-like 3 peptide (INSL3) on the most abundant bone cell population, osteocytes, is unknown. In this study, we aimed to investigate the relationship between INSL3 and sclerostin, an osteocyte-specific protein that negatively regulates bone formation. Design Serum sclerostin and INSL3 levels were evaluated in Klinefelter syndrome (KS) and healthy controls. In vitro effect of INSL3 on sclerostin production was evaluated in human cultured osteocytes. Patients A total of 103 KS patients and 60 age- and sex-matched controls were recruited. Main Outcome Measures Serum sclerostin and INSL3 levels were assessed by enzyme-linked immunosorbent assay. Osteocytes were isolated by fluorescence-assisted cell sorting. Sclerostin expression was evaluated by western blot, immunofluorescence, and reverse transcription polymerase chain reaction. Measurement of bone mineral density was done by dual-energy X-ray absorptiometry at lumbar spine (L1-L4) and femoral neck. Results Sclerostin levels were significantly increased in KS subjects, and negatively correlated with INSL3 levels in both cohorts and with bone mineral density in the KS group. Stimulation of cultured osteocytes with INSL3 at 10-7 M significantly decreased both sclerostin messenger RNA and protein expression. Conclusions We report a negative association between the testicular hormone INSL3 and the osteocytic negative regulator of bone formation, sclerostin. We further explored this association in vitro and showed that INSL3 was able to reduce sclerostin expression. These results add further knowledge on the emerging role of sclerostin as a therapeutic target for osteoporosis treatment.

  • profiling insulin like factor 3 INSL3 signaling in human osteoblasts
    PLOS ONE, 2011
    Co-Authors: Alberto Ferlin, Giuseppe Taglialavoro, Lisa Perilli, Lisa Gianesello, Carlo Foresta
    Abstract:

    Background Young men with mutations in the gene for the INSL3 receptor (Relaxin family peptide 2, RXFP2) are at risk of reduced bone mass and osteoporosis. Consistent with the human phenotype, bone analyses of Rxfp2−/− mice showed decreased bone volume, alterations of the trabecular bone, reduced mineralizing surface, bone formation, and osteoclast surface. The aim of this study was to elucidate the INSL3/RXFP2 signaling pathways and targets in human osteoblasts. Methodology/Principal Findings Alkaline phosphatase (ALP) production, protein phosphorylation, intracellular calcium, gene expression, and mineralization studies have been performed. INSL3 induced a significant increase in ALP production, and Western blot and ELISA analyses of multiple intracellular signaling pathway molecules and their phosphorylation status revealed that the MAPK was the major pathway influenced by INSL3, whereas it does not modify intracellular calcium concentration. Quantitative Real Time PCR and Western blotting showed that INSL3 regulates the expression of different osteoblast markers. Alizarin red-S staining confirmed that INSL3-stimulated osteoblasts are fully differentiated and able to mineralize the extracellular matrix. Conclusions/Significance Together with previous findings, this study demonstrates that the INSL3/RXFP2 system is involved in bone metabolism by acting on the MAPK cascade and stimulating transcription of important genes of osteoblast maturation/differentiation and osteoclastogenesis.

  • mutations in INSL3 and rxfp2 genes in cryptorchid boys
    Annals of the New York Academy of Sciences, 2009
    Co-Authors: Alberto Ferlin, Riccardo Selice, Daniela Zuccarello, Andrea Garolla, Cinzia Vinanzi, Francesco Ganz, Gian Franco Zanon, Biagio Zuccarello, Carlo Foresta
    Abstract:

    Mutations in the INSL3 and RXFP2 genes have been associated with human cryptorchidism but with contrasting data. We analyzed the frequency of mutations in these genes in 600 newborns with cryptorchidism (396 unilateral and 204 bilateral) and 300 noncryptorchid subjects. We found five RXFP2 mutations in five bilateral cryptorchid boys, one INSL3 mutation in a unilateral cryptorchid boy, and one INSL3 mutation in a boy with unilateral cryptorchidism at birth and spontaneous descent during the first month of life. Overall, the frequency of INSL3 and RXFP2 mutations was therefore 7/600 at birth (1.2%) and 7/303 (2.3%) in persistent cryptorchid boys, with a higher prevalence of bilateral forms (5/120, 4.2%). No mutations were found in controls. This study confirmed the association between INSL3 and RXFP2 gene mutations and human cryptorchidism.

  • INSL3 rxfp2 signaling in testicular descent
    Annals of the New York Academy of Sciences, 2009
    Co-Authors: Shu Feng, Ross A D Bathgate, John D Wade, Alberto Ferlin, Anne Truong, Sean T Corbett, Shuo Han, Mounia Tannourlouet, Dolores J Lamb, Carlo Foresta
    Abstract:

    Mutations of the insulin-like peptide 3 (INSL3) hormone or its receptor, RXFP2, cause intraabdominal cryptorchidism in male mice. Specific RXFP2 expression in mouse gubernacula was detected at embryonic day 14.5 and markedly increased after birth in the developing cremaster muscle, as well as in the epididymis and testicular Leydig and germ cells. INSL3 treatment stimulated cell proliferation of embryonic gubernacular and Leydig cells, implicating active INSL3-mediated signaling. The transcription factor SOX9, a known male sex determination factor, upregulated the activity of the RXFP2 promoter. INSL3 is sufficient to direct the first transabdominal phase of testicular descent in the absence of hypothalamic-pituitary-gonadal axis signaling or Hoxa10, although these factors are important for inguinoscrotal testicular descent. Similarly, conditional ablation of the androgen receptor gene in gubernacular cells resulted in disruption of inguinoscrotal descent. We performed mutation screening of INSL3 and RXFP2 in human patients with cryptorchidism and control subjects from different populations in Europe and the USA. Several missense mutations were described in both the INSL3 and RXFP2 genes. A novel V39G INSL3 mutation in a patient with cryptorchidism was identified; however, the functional analysis of the mutant peptide did not reveal compromised function. In more than 2000 patients and controls analyzed to date, the T222P RXFP2 mutation is the only one strongly associated with the mutant phenotype. The T222P mutant receptor, when transfected into 293T cells, had severely decreased cell membrane expression, providing the basis for the functional deficiency of this mutation.