An Isolated Hypogonadotropic Hypogonadism due to a L102P Inactivating Mutation of KISS1R/GPR54 in a Large Family

KISS1R (GPR54) mutations have been reported in several patients with congenital normosmic idiopathic hypogonadotropic hypogonadism (nIHH). We aim to describe in detail nIHH patients with KISS1R (GPR54) mutations belonging to one related extended family and to review the literature. A homozygous mutation (T305C) leading to a leucine substitution with proline (L102P) was found in three affected kindred (2 males and 1 female) from a consanguineous Saudi Arabian family. This residue is localized within the first exoloop of the receptor, affects a highly conserved amino acid, perturbs the conformation of the transmembrane segment, and impairs its function. In the affected female, a combined gonadotropin administration restored regular period and ovulation and she conceived with a healthy baby boy after 4 years of marriage. We showed that a loss-of-function mutation (p.Tyr305C) in the KISS1R gene can cause (L102P) KISS1 receptor dysfunction and familial nIHH, revealing the crucial role of this amino acid in KISS1R function. The observed restoration of periods and later on pregnancy by an exogenous gonadotropin administration further support, in humans, that the KISS1R mutation has no other harmful effects on the patients apart from the gonadotropin secretion impairment.

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Neuroendocrine Phenotype Analysis in Five Patients with Isolated Hypogonadotropic Hypogonadism due to a L102P Inactivating Mutation of GPR54

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jc.2006-2147 ◽

2007 ◽

Vol 92 (3) ◽

pp. 1137-1144 ◽

Cited By ~ 118

Author(s):

Yardena Tenenbaum-Rakover ◽

Monique Commenges-Ducos ◽

André Iovane ◽

Chantal Aumas ◽

Osnat Admoni ◽

...

Keyword(s):

Hypogonadotropic Hypogonadism ◽

In Vivo Studies ◽

Homozygous Mutation ◽

Loss Of Function ◽

Phenotypic Analysis ◽

Lh Pulsatility ◽

Gonadotropic Axis ◽

Phenotype Analysis ◽

Inactivating Mutation

Abstract Context: Loss of function of the G protein-coupled receptor of kisspeptins (GPR54) was recently described as a new cause of isolated hypogonadotropic hypogonadism. In vivo studies performed in several species have confirmed the major role of kisspeptins in neuroendocrine regulation of the gonadotropic axis and therefore sexual maturation. Objective: The objective of this study was to specify the exact contribution of kisspeptins and GPR54 to the initiation of puberty in humans. Design: Detailed neuroendocrine descriptions were performed in five patients with isolated hypogonadotropic hypogonadism bearing a new GPR54-inactivating mutation. Results: A homozygous mutation (T305C) leading to a leucine substitution with proline (L102P) was found in the five affected patients. This substitution completely inhibited GPR54 signaling. Phenotypic analysis revealed variable expressivity in the same family, either partial or complete gonadotropic deficiency. LH pulsatility analysis showed peaks with normal frequency but low amplitude. Repeated GnRH tests performed between 12 and 21 yr of age in one affected male revealed progressive changes in pituitary response from an early pubertal to an almost full pubertal pattern. Double GnRH test stimulations performed at a 120-min interval showed reduced dynamic pituitary response in GPR54-mutated patients. Conclusion: GPR54 inactivation does not impede neuroendocrine onset of puberty; rather, it delays and slows down pubertal maturation of the gonadotropic axis. The L102P loss of function mutation in GPR54 results in a more quantitative than qualitative defect of gonadotropic axis activation.

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Characterization of the Potent Luteinizing Hormone-Releasing Activity of KiSS-1 Peptide, the Natural Ligand of GPR54

Endocrinology ◽

10.1210/en.2004-0836 ◽

2005 ◽

Vol 146 (1) ◽

pp. 156-163 ◽

Cited By ~ 298

Author(s):

V. M. Navarro ◽

J. M. Castellano ◽

R. Fernández-Fernández ◽

S. Tovar ◽

J. Roa ◽

...

Keyword(s):

Excitatory Amino Acid ◽

Hypogonadotropic Hypogonadism ◽

Mrna Levels ◽

Central Administration ◽

Experimental Conditions ◽

Gonadotropin Secretion ◽

Neuroendocrine Control ◽

Lh Secretion

Loss-of-function mutations of the gene encoding GPR54, the putative receptor for the KiSS-1-derived peptide metastin, have been recently associated with hypogonadotropic hypogonadism, in both rodents and humans. Yet the actual role of the KiSS-1/GPR54 system in the neuroendocrine control of gonadotropin secretion remains largely unexplored. To initiate such analysis, the effects of KiSS-1 peptide on LH secretion were monitored using in vivo and in vitro settings under different experimental conditions. Central intracerebroventricular administration of KiSS-1 peptide potently elicited LH secretion in vivo over a range of doses from 10 pmol to 1 nmol. The effect of centrally injected KiSS-1 appeared to be mediated via the hypothalamic LHRH. However, no effect of central administration of KiSS-1 was detected on relative LHRH mRNA levels. Likewise, systemic (ip and iv) injection of KiSS-1 markedly stimulated LH secretion. This effect was similar in terms of maximum response to that of central administration of KiSS-1 and might be partially attributed to its ability to stimulate LH secretion directly at the pituitary. Finally, the LH-releasing activity of KiSS-1 was persistently observed after blockade of endogenous excitatory amino acid and nitric oxide pathways, i.e. relevant neurotransmitters in the neuroendocrine control of LH secretion. In summary, our results provide solid evidence for a potent stimulatory effect of KiSS-1 on LH release, acting at central levels (likely the hypothalamus) and eventually at the pituitary, and further document a novel role of the KiSS-1/GPR54 system as a relevant downstream element in the neuroendocrine network governing LH secretion.

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Abstract 442: Generation of an Abcg1 Knock Out Mouse on the Reversa Background

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.36.suppl_1.442 ◽

2016 ◽

Vol 36 (suppl_1) ◽

Author(s):

Gillian Douglas ◽

Lucy Trelfa ◽

Keith Channon ◽

Ben Davies ◽

Shoumo Bhattacharya

Keyword(s):

Amino Acid ◽

Intima Media Thickness ◽

Null Alleles ◽

Cholesterol Transport ◽

Loss Of Function ◽

Phosphate Binding ◽

Knock Out ◽

Plaque Regression ◽

Genomic Editing

Background: Clinically HDL mediated reverse cholesterol transport (RCT) from macrophages has been shown to be inversely associated with carotid intima media thickness. Cholesterol efflux to mature HDL is mediated by ATP binding cassette transporter G1 (Abcg1). Abcg1 pays a key role in cholesterol transport with loss of function in macrophages and endothelial cells associated with significant cholesterol accumulation. However, mechanistic studies into the role of Abgc1 in plaque regression have been restricted due to the limitations of current regression models. Aims: To use TALENS mediated genomic editing to generate an Abcg1 knockout mouse on the REVERSA background to enable the investigation of its role in plaque regression. Methods and results: TALENs constructs were targeted to exon 3 upstream of the phosphate binding Walker A domain. TALEN mRNA was injected into REVERSA oocytes which were then implanted into foster mice. Founders were screened by Cel1 nuclease assay and sequencing. Three independent alleles were identified two of which create frameshift mutations (predicted to be null alleles) and one which resulted in a 3 amino acid deletion and a one amino acid substitution near the Walker A domain (potential hypomorphic allele). The two founder lines with frame shift mutations (KO 145 and 171) were taken forward for additional analysis. RNA extracted from primary macrophages from WT (REVERSA) and homozygous Abcg1 knockout mice was used to confirm the mutation was transcribed to RNA. Intron-spanning primers were designed and a product of the expected size was obtained and sequence analysis confirmed the insertion (KO-145) and deletion (KO-171) within the WALKER A domain of Abcg1. To ensure the mutations resulted in loss of function, a radioactive RCT assay was carried out in bone marrow derived primary macrophages. A significant decrease in RCT to HDL was observed in macrophages from both the KO-145 and KO-171 lines as expected there was no difference in RCT to ApoA1-I. Conclusions: Using genomic editing we have generated a gene specific knockout on the REVERSA background which will enable, for the first time, the investigation of the role of Abcg1 in plaque regression.

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Webb–Dattani Syndrome: Report of a Saudi Arabian Family with a Novel Homozygous Mutation in the ARNT2 Gene

Journal of Pediatric Neurology ◽

10.1055/s-0037-1621720 ◽

2018 ◽

Vol 17 (02) ◽

pp. 071-076 ◽

Cited By ~ 1

Author(s):

Nouriya Abbas Al-Sannaa ◽

Alexander Pepler ◽

Hind Y. Al-Abdulwahed ◽

Sami I. Al-Majed ◽

Rifat F. Abdi ◽

...

Keyword(s):

Saudi Arabian ◽

Autosomal Recessive Disorder ◽

Cortical Blindness ◽

Hormone Deficiency ◽

Pituitary Hormone ◽

Homozygous Mutation ◽

Loss Of Function ◽

Whole Exome ◽

Retinal Examination

AbstractWebb–Dattani syndrome (WEDAS) is an autosomal recessive disorder caused by mutation in the ARNT2 gene characterized by frontotemporal hypoplasia, globally delayed development, and pituitary and hypothalamic insufficiency. The condition is reported to be associated with consanguinity and with Saudi Arabian ancestry. Here we describe a family of three affected siblings born to healthy second cousin parents of Saudi Arabian ancestry. The children presented at 3 months of age with congenital central hypotonia and hypoventilation, central diabetes insipidus, multiple pituitary hormone deficiency, severe developmental delay, acquired microcephaly, cortical blindness with normal retinal examination, seizures, and gastroesophageal reflux. Whole exome sequencing detected a homozygous unclear variant (c.378C>T; p.G126G) in the ARNT2 gene in both the affected twins. According to splice prediction programs, this variant results in the creation of a cryptic donor splice site, possibly leading to a loss of function. These data support the role of the detected mutation in the ARNT2 gene in causing the described phenotype.

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PRKAR1A mutation causing pituitary-dependent Cushing disease in a patient with Carney complex

Acta Endocrinologica ◽

10.1530/eje-17-0227 ◽

2017 ◽

Vol 177 (2) ◽

pp. K7-K12 ◽

Cited By ~ 15

Author(s):

Florian W Kiefer ◽

Yvonne Winhofer ◽

Donato Iacovazzo ◽

Márta Korbonits ◽

Stefan Wolfsberger ◽

...

Keyword(s):

Cushing Syndrome ◽

Pituitary Tumour ◽

Carney Complex ◽

Regulatory Subunit ◽

Loss Of Function ◽

Cushing Disease ◽

First Case ◽

Acth Secreting ◽

Inactivating Mutation

Context Carney complex (CNC) is an autosomal dominant condition caused, in most cases, by an inactivating mutation of the PRKAR1A gene, which encodes for the type 1 alpha regulatory subunit of protein kinase A. CNC is characterized by the occurrence of endocrine overactivity, myxomas and typical skin manifestations. Cushing syndrome due to primary pigmented nodular adrenocortical disease (PPNAD) is the most frequent endocrine disease observed in CNC. Case description Here, we describe the first case of a patient with CNC and adrenocorticotropic hormone (ACTH)-dependent Cushing disease due to a pituitary corticotroph adenoma. Loss-of-heterozygosity analysis of the pituitary tumour revealed loss of the wild-type copy of PRKAR1A, suggesting a role of this gene in the pituitary adenoma development. Conclusion PRKAR1A loss-of-function mutations can rarely lead to ACTH-secreting pituitary adenomas in CNC patients. Pituitary-dependent disease should be considered in the differential diagnosis of Cushing syndrome in CNC patients.

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Kisspeptin and KISS1R: a critical pathway in the reproductive system

Reproduction ◽

10.1530/rep-08-0091 ◽

2008 ◽

Vol 136 (3) ◽

pp. 295-301 ◽

Cited By ~ 26

Author(s):

Elena Gianetti ◽

Stephanie Seminara

Keyword(s):

Reproductive System ◽

Hypogonadotropic Hypogonadism ◽

Critical Role ◽

Loss Of Function ◽

Critical Pathway ◽

Gonadotropin Secretion ◽

Feedback Effects ◽

Powerful Stimulus ◽

Pubertal Transition ◽

Hypothalamic Level

AbstractIn 2003, three groups around the world simultaneously discovered that KISS1R (GPR54) is a key gatekeeper of sexual maturation in both mice and men. Developmental changes in the expression of the ligand for KISS1R, kisspeptin, support its critical role in the pubertal transition. In addition, kisspeptin, a powerful stimulus of GNRH-induced gonadotropin secretion and may modulate both positive and negative sex steroid feedback effects at the hypothalamic level. Genetic studies in humans have revealed both loss-of-function and gain-of-function mutations in patients with idiopathic hypogonadotropic hypogonadism and precocious puberty respectively. This review examines the kisspeptin/KISS1R pathway in the reproductive system.

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The role of family networks and social capital on women's fertility intentions in Ouagadougou, Burkina Faso

Journal of Demographic Economics ◽

10.1017/dem.2021.18 ◽

2021 ◽

pp. 1-19

Author(s):

Moussa Bougma ◽

Clémentine Rossier

Keyword(s):

Social Capital ◽

Extended Family ◽

Large Family ◽

Economic Resources ◽

High Fertility ◽

Family Networks ◽

Children's Schooling

Abstract Family solidarities remain strong in African societies. In Ouagadougou, transfers within extended family networks provide an omnipresent means for coping with life's difficulties, and the desired number of children remains relatively high. The role of family networks in maintaining high fertility is rarely studied however for lack of data in conventional demographic surveys. This study uses original retrospective data and logistic regression methods to explore the role of the extended family's social capital in shaping women's desire for children in Ouagadougou. Results show that women belong to three types of family networks: (1) women who belong to large family networks on both her own and her husband's side and who maintain a moderate number of close relations with their own relatives; (2) women who also belong to large family networks on both their and their husband's sides but who maintain a greater number of close relations with their own blood relatives; (3) unmarried women with relatives only on their side and numerous close relations with their family. Support for children's schooling comes more often from women's relatives in networks type 2 and 3, and from husbands' relatives in network type 1. Support for children's schooling increases with the level of economic resources in family networks (proxied by the presence of a public employee), in all network types. Women in type 2 networks (centered on women's relatives) are more likely to want additional children compared to women in type 1 networks (centered on their husband's relatives), after controlling for economic resources in networks. This result suggests that practical support provided by family members could play a role, on top of economic support, in encouraging high fertility in Ouagadougou.

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POP-1 controls axis formation during early gonadogenesis inC. elegans

Development ◽

10.1242/dev.129.2.443 ◽

2002 ◽

Vol 129 (2) ◽

pp. 443-453 ◽

Cited By ~ 10

Author(s):

Kellee R. Siegfried ◽

Judith Kimble

Keyword(s):

Amino Acid ◽

Asymmetric Division ◽

Early Embryo ◽

Binding Domain ◽

Axis Formation ◽

Loss Of Function ◽

C Elegans ◽

Leader Cell ◽

Control Organ

The shape and polarity of the C. elegans gonad is defined during early gonadogenesis by two somatic gonadal precursor cells, Z1 and Z4, and their descendants. Z1 and Z4 divide asymmetrically to establish the proximal-distal axes of the gonad and to generate regulatory leader cells that control organ shape. In this paper, we report that pop-1, the C. elegans TCF/LEF-1 transcription factor, controls the first Z1/Z4 asymmetric division and hence controls proximal-distal axis formation. We have identified two pop-1(Sys) alleles (for symmetrical sisters) that render the Z1/Z4 divisions symmetrical. The pop-1(q645) allele is fully penetrant for the Sys gonadogenesis defect in hermaphrodites, but affects male gonads weakly; pop-1(q645) alters a conserved amino acid in the β-catenin binding domain. The pop-1(q624) allele is weakly penetrant for multiple defects and appears to be a partial loss-of-function mutation; pop-1(q624) alters a conserved amino acid in the HMG-box DNA binding domain. Zygotic pop-1(RNAi) confirms the role of pop-1 in Z1/Z4 asymmetry and reveals additional roles of pop-1, including one in leader cell migration. Two other Wnt pathway regulators, wrm-1 and lit-1, have the same effect as pop-1 on Z1/Z4 asymmetry. Therefore, wrm-1 and lit-1 are required for pop-1 function, rather than opposing it as observed in the early embryo. We conclude that POP-1 controls the Z1/Z4 asymmetric division and thereby establishes the proximal-distal axes of the gonad. This control over proximal-distal polarity extends our view of Wnt signaling in C. elegans, which had previously been known to control anterior-posterior polarities.

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Impact of broad regulatory regions on Gdf5 expression and function in knee development and susceptibility to osteoarthritis

Annals of the Rheumatic Diseases ◽

10.1136/annrheumdis-2017-212475 ◽

2018 ◽

Vol 77 (3) ◽

pp. 450-450 ◽

Cited By ~ 15

Author(s):

Steven K Pregizer ◽

Ata M Kiapour ◽

Mariel Young ◽

Hao Chen ◽

Michael Schoor ◽

...

Keyword(s):

Artificial Chromosome ◽

Regulatory Sequence ◽

Regulatory Sequences ◽

Loss Of Function ◽

Regulatory Regions ◽

Control Knee ◽

And Function ◽

Inactivating Mutation ◽

Femoral Condyles

ObjectivesGiven the role of growth and differentiation factor 5 (GDF5) in knee development and osteoarthritis risk, we sought to characterise knee defects resulting from Gdf5 loss of function and how its regulatory regions control knee formation and morphology.MethodsThe brachypodism (bp) mouse line, which harbours an inactivating mutation in Gdf5, was used to survey how Gdf5 loss of function impacts knee morphology, while two transgenic Gdf5 reporter bacterial artificial chromosome mouse lines were used to assess the spatiotemporal activity and function of Gdf5 regulatory sequences in the context of clinically relevant knee anatomical features.ResultsKnees from homozygous bp mice (bp/bp) exhibit underdeveloped femoral condyles and tibial plateaus, no cruciate ligaments, and poorly developed menisci. Secondary ossification is also delayed in the distal femur and proximal tibia. bp/bp mice have significantly narrower femoral condyles, femoral notches and tibial plateaus, and curvier medial femoral condyles, shallower trochlea, steeper lateral tibial slopes and smaller tibial spines. Regulatory sequences upstream from Gdf5 were weakly active in the prenatal knee, while downstream regulatory sequences were active throughout life. Importantly, downstream but not upstream Gdf5 regulatory sequences fully restored all the key morphological features disrupted in the bp/bp mice.ConclusionsKnee morphology is profoundly affected by Gdf5 absence, and downstream regulatory sequences mediate its effects by controlling Gdf5 expression in knee tissues. This downstream region contains numerous enhancers harbouring human variants that span the osteoarthritis association interval. We posit that subtle alterations to morphology driven by changes in downstream regulatory sequence underlie this locus’ role in osteoarthritis risk.

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splitGFP Technology Reveals Dose-Dependent ER-Mitochondria Interface Modulation by α-Synuclein A53T and A30P Mutants

Cells ◽

10.3390/cells8091072 ◽

2019 ◽

Vol 8 (9) ◽

pp. 1072 ◽

Cited By ~ 11

Author(s):

Tito Calì ◽

Denis Ottolini ◽

Mattia Vicario ◽

Cristina Catoni ◽

Francesca Vallese ◽

...

Keyword(s):

Amino Acid ◽

Amino Acid Substitution ◽

Mitochondrial Function ◽

Cell Metabolism ◽

Loss Of Function ◽

Function Mechanism ◽

Dose Dependent ◽

Familial Parkinson’S Disease ◽

Interface Modulation

Familial Parkinson’s disease (PD) is associated with duplication or mutations of α-synuclein gene, whose product is a presynaptic cytosolic protein also found in mitochondria and in mitochondrial-associated ER membranes. We have originally shown the role of α-syn as a modulator of the ER-mitochondria interface and mitochondrial Ca2+ transients, suggesting that, at mild levels of expression, α-syn sustains cell metabolism. Here, we investigated the possibility that α-syn action on ER-mitochondria tethering could be compromised by the presence of PD-related mutations. The clarification of this aspect could contribute to elucidate key mechanisms underlying PD. The findings reported so far are not consistent, possibly because of the different methods used to evaluate ER-mitochondria connectivity. Here, the effects of the PD-related α-syn mutations A53T and A30P on ER-mitochondria relationship were investigated in respect to Ca2+ handling and mitochondrial function using a newly generated SPLICS sensor and aequorin-based Ca2+measurements. We provided evidence that A53T and A30P amino acid substitution does not affect the ability of α-syn to enhance ER/mitochondria tethering and mitochondrial Ca2+ transients, but that this action was lost as soon as a high amount of TAT-delivered A53T and A30P α-syn mutants caused the redistribution of α-syn from cytoplasm to foci. Our results suggest a loss of function mechanism and highlight a possible connection between α-syn and ER-mitochondria Ca2+ cross-talk impairment to the pathogenesis of PD.

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