Initiation Of Puberty Research Articles

LGR4 deficiency results in delayed puberty through impaired Wnt/β-catenin signaling.

The initiation of puberty is driven by an upsurge in hypothalamic gonadotropin-releasing hormone (GnRH) secretion. In turn, GnRH secretion upsurge depends on the development of a complex GnRH neuroendocrine network during embryonic life. Although delayed puberty (DP) affects up to 2% of the population, is highly heritable, and is associated with adverse health outcomes, the genes underlying DP remain largely unknown. We aimed to discover regulators by whole-exome sequencing of 160 individuals of 67 multigenerational families in our large, accurately phenotyped DP cohort. LGR4 was the only gene remaining after analysis that was significantly enriched for potentially pathogenic, rare variants in 6 probands. Expression analysis identified specific Lgr4 expression at the site of GnRH neuron development. LGR4 mutant proteins showed impaired Wnt/β-catenin signaling, owing to defective protein expression, trafficking, and degradation. Mice deficient in Lgr4 had significantly delayed onset of puberty and fewer GnRH neurons compared with WT, whereas lgr4 knockdown in zebrafish embryos prevented formation and migration of GnRH neurons. Further, genetic lineage tracing showed strong Lgr4-mediated Wnt/β-catenin signaling pathway activation during GnRH neuron development. In conclusion, our results show that LGR4 deficiency impairs Wnt/β-catenin signaling with observed defects in GnRH neuron development, resulting in a DP phenotype.

Bone Microarchitecture Assessed by Trabecular Bone Score Is Independent of Mobility Level or Height in Pediatric Patients with Cerebral Palsy.

Bone strength and fracture risk do not only depend on bone density, but also on bone structure. The trabecular bone score (TBS) evaluates homogeneity of bone microarchitecture indirectly by measuring gray-level variations of two-dimensional (2D) DXA images. Although TBS is well-established for adults, there have been only few publications in pediatrics. In this monocentric retrospective analysis, we investigated TBS in children and adolescents with cerebral palsy (CP), a patient group vulnerable to low bone mineral mass due to impaired mobility. The influence of different parameters on TBS and areal BMD (aBMD) were evaluated, as well as the relationship between TBS and aBMD. We compared TBS values of our study population to a reference population. A total of 472 lumbar spine-dual-energy X-ray absorptiometry (LS-DXA) scans of children and adolescents with CP (205 female), aged between 4 and 18 years, were analyzed. The DXA-scans were part of the routine examination. The children had no records of fractures or specific bone diseases. Our study population with CP had similar TBS as the reference population. TBS did not increase with age until an inflection point at 10 years in females, and 12 years in males. Girls had significantly higher TBS than boys (p = .049) and pubertal girls aged 8 to 13 years had significantly higher TBS than prepubertal girls (p = .009). TBS standard deviation score for age (SDS-TBS) and aBMD Z-scores correlated weakly (p < .001; R = 0.276 [males], R = 0.284 [females]). Other than for aBMD Z-scores, SDS-TBS was not influenced by age-adjusted height Z-scores and there was no significant difference in SDS-TBS when grouped by mobility levels, using the Gross Motor Function Classification System (GMFCS). Our results indicate that children with CP have a similar homogeneous distribution of trabecular microarchitecture as controls. Puberty initiation appears to be essential for increase of TBS with age and for sex differences. TBS seems less influenced by body composition, height, and mobility than aBMD. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.

The Peripubertal Decline in Makorin Ring Finger Protein 3 Expression is Independent of Leptin Action.

A critical body weight is necessary for pubertal development, an effect mediated in part by leptin. The potential regulation by leptin of Makorin Ring Finger Protein 3 (MKRN3), in which loss-of-function mutations are the most common genetic cause of central precocious puberty, has not been previously explored. In mice, expression of Mkrn3 in the hypothalamic arcuate nucleus is high early in life and declines before the onset of puberty. Therefore, we aimed to explore if leptin contributes to the decrease in hypothalamic Mkrn3 mRNA levels observed in mice during pubertal development. We first used a leptin-deficient (ob/ob) mouse model. Mkrn3 mRNA levels in the mediobasal hypothalamus (MBH), which includes the arcuate nucleus, and in the preoptic area (POA), both showed a significant decrease with age from postnatal day (PND) 12 to PND30 in ob/ob mice in both males and females, similar to that observed in wild-type mice. To further explore the effects of leptin on Mkrn3 expression, we exposed prepubertal wild-type mice to high levels of leptin from age PND9-12, which did not result in any significant difference in Mkrn3 expression levels in either the MBH or POA. In summary, regulation of Mkrn3 expression by leptin was not observed in either the MBH or the POA, 2 hypothalamic sites important for pubertal maturation. These data suggest that the decline in Mkrn3 at the onset of puberty may occur independently of leptin and support our hypothesis that MKRN3 is a bona fide controller of puberty initiation.

Transcriptional activity of FIGLA, NEUROG2, and EGR1 transcription factors associated with polymorphisms in the proximal regulatory region of GPR54 gene in cattle

Activity of transcription factors affect synthesis of G-protein coupled receptor 54 (GPR54), an important factor in regulation of initiation of puberty. Expression of the GPR54 gene in cattle is associated with polymorphisms in the proximal regulatory region (PRR) of the GPR54 gene. Transcription resulting in production of GPR54 mRNA transcript occurs as a result of transcription factor (TF) interactions in the PRR. Polymorphisms in the PRR may be associated with extent of activity of these TFs. Folliculogenesis-specific BHLH TF (FIGLA), neurogenin 2 (NEUROG2), and early growth response 1 (EGR1) are important in modulation of ovarian follicle development and neurons synthesizing GnRH, thus, regulating biosynthesis of luteinizing hormone. The aim of this study, therefore, was to assess the transcription-activating potential of binding sites for FIGLA, NEUROG2, and EGR1 TFs in the GPR54 promoter of cattle. Two luciferase-based promoters, ATC and CCT, which contain three single nucleotide polymorphisms (SNPs), A/C-794, T/C-663, and C/T-601, in the GPR54 PRR, were analyzed to evaluate gene expression and activation of different promoters by FIGLA, NEUROG2, and EGR1. The FIGLA induced GPR54 transcription through the CCT, whereas NEUROG2 and EGR1 induced GPR54 transcription through the ATC promoter-binding site. The CCT-activating effects of FIGLA were greater (2.56-fold) than the ATC-activating effects (P < 0.05). The ATC-activating effects of NEUROG2 and EGR1 were markedly greater (12.91- and 8.41-fold; P < 0.01) than CCT-activating effects. The polymorphisms, CCT and ATC, of the cattle GPR54 affect the activity of transcription factors, therefore, have an important effect on production of GPR54 mRNA transcript.

MKRN3 inhibits the reproductive axis through actions in kisspeptin-expressing neurons.

The identification of loss-of-function mutations in MKRN3 in patients with central precocious puberty in association with the decrease in MKRN3 expression in the medial basal hypothalamus of mice before the initiation of reproductive maturation suggests that MKRN3 is acting as a brake on gonadotropin-releasing hormone (GnRH) secretion during childhood. In the current study, we investigated the mechanism by which MKRN3 prevents premature manifestation of the pubertal process. We showed that, as in mice, MKRN3 expression is high in the hypothalamus of rats and nonhuman primates early in life, decreases as puberty approaches, and is independent of sex steroid hormones. We demonstrated that Mkrn3 is expressed in Kiss1 neurons of the mouse hypothalamic arcuate nucleus and that MKRN3 repressed promoter activity of human KISS1 and TAC3, 2 key stimulators of GnRH secretion. We further showed that MKRN3 has ubiquitinase activity, that this activity is reduced by MKRN3 mutations affecting the RING finger domain, and that these mutations compromised the ability of MKRN3 to repress KISS1 and TAC3 promoter activity. These results indicate that MKRN3 acts to prevent puberty initiation, at least in part, by repressing KISS1 and TAC3 transcription and that this action may involve an MKRN3-directed ubiquitination-mediated mechanism.

SUN-033 A Rare Case: Bone Pain and Continued Linear Growth in a Young Adult Male Due to Aromatase Deficiency

Introduction:Aromatase, the product of CYP19A1, catalyzes the conversion of androgens to estrogens. 46, XX infants with aromatase deficiency, due to androgen excess, present with ambiguous genitalia at birth. In 46, XY individuals, however, the subtle phenotypic features make the diagnosis even more difficult. Less than 15 male cases were reported in the literature and we present the first case of aromatase deficiency diagnosed in Taiwan.Clinical Case:A 23-year-old man, Burman overseas student of Chinese descent, presented to an orthopedist with a two-year history of left ankle pain, which was diagnosed as gout by his previous physician. Unexpectedly, unfused growth plates were discovered so he was referred to our pediatric endocrine clinic for evaluation. Reviewing his past history, we learned he is the third child of consanguineous parents. His mother experienced deepening of voice during this pregnancy which resolved following parturition. He was 177 cm tall at the age of 19. At the time he presented to our clinic, he weighed 95.3 kg and was 183 cm tall. Physical exam showed the ratio of U/L segment to be 0.82, stretched penile length 6.5 cm, bilateral testes > 25 mL, pubic hair at Tanner stage V, and presence of genu valgum. The skeletal age was 14 years and 6 months. Labs showed FSH 19.7 IU/L (0.7–11.1), LH 8.18 IU/L (0.8–7.6), total testosterone 1335 ng/dL (240–871), estradiol <20 pg/mL, DHEA-S 13.41 μmol/L (6.5–14.6), androstenedione 5.73 nmol/L (3.5–9.8) and 17-OH progesterone 6.55 nmol/L (2–10). GnRH (100 μg i.v) stimulation test showed a supranormal basal FSH level and a normal to higher LH response (FSH at baseline/peak were 23.0/38.6 IU/L; LH at baseline/peak were 8.81/47.7 IU/L). Under the clinical suspicion of aromatase deficiency, we performed genetic sequencing of CYP19A1 (NM_031226) and found a homozygous missense variant c.1108G>A (V370M), a previously reported pathogenic mutation.A diagnosis of aromatase deficiency was made. He also had hypertension (156/87 mmHg), dyslipidemia (T-cholesterol 236 mg/dL, LDL-C 175 mg/dL) and insulin resistance (AC glucose 87 mg/dL, insulin 23.5 μU/mL, HOMA-IR 5.0, Hb1Ac 5.6%). Bone mineral density of lumbar spine (DXA) showed a T-score of -2.8, consistent with the diagnosis of osteoporosis.Conclusion:Estrogen is pivotal for epiphyseal closure in both sexes. As demonstrated in this case, estrogen deficiency in men results in tall stature and eunuchoid habitus, while it is also associated with low bone density and metabolic syndrome. The gonadotropin response in this report suggests the inhibitory role of estrogen in the male HPG axis. Clinicians may consider this rare diagnosis for men in their late teens or early twenties, who have spontaneous initiation of puberty, presenting with bone pain and continued linear growth.

Leptin stimulates gonadotropin release and ovarian development in marine teleost chub mackerel

Leptin transmits information about energy stored in the periphery to the reproductive axis and is an essential signal for puberty initiation in mammals; however, to date, few studies have focused on the direct effects of leptin stimulation on reproductive factors in fish. This study demonstrated the effect of leptin stimulation on important reproductive factors and ovarian development in the marine teleost chub mackerel (Scomber japonicus). We prepared recombinant leptin and conducted functional analyses through in vitro bioassays using primary pituitary cells, long-term leptin treatment administered to pre-pubertal females, and intracerebroventricular (ICV) administration. The results showed that leptin stimulation strongly induced gonadotropin (follicle-stimulating hormone: FSH and luteinizing hormone: LH) secretion from pituitary cells collected from pre-pubertal females, and that long-term leptin treatment significantly promoted ovarian development and triggered pubertal onset. Furthermore, ICV administration of leptin did not affect kisspeptin gene expression but significantly upregulated gonadotropin-releasing hormone 1 (gnrh1), fshb and lhb gene expression in sexually immature females. These results strongly suggest leptin as an important signal for reproductive-axis activation in chub mackerel.

MKRN3 regulates the epigenetic switch of mammalian puberty via ubiquitination of MBD3.

Central precocious puberty (CPP) refers to a human syndrome of early puberty initiation with characteristic increase in hypothalamic production and release of gonadotropin-releasing hormone (GnRH). Previously, loss-of-function mutations in human MKRN3, encoding a putative E3 ubiquitin ligase, were found to contribute to about 30% of cases of familial CPP. MKRN3 was thereby suggested to serve as a ‘brake’ of mammalian puberty onset, but the underlying mechanisms remain as yet unknown. Here, we report that genetic ablation of Mkrn3 did accelerate mouse puberty onset with increased production of hypothalamic GnRH1. MKRN3 interacts with and ubiquitinates MBD3, which epigenetically silences GNRH1 through disrupting the MBD3 binding to the GNRH1 promoter and recruitment of DNA demethylase TET2. Our findings have thus delineated a molecular mechanism through which the MKRN3–MBD3 axis controls the epigenetic switch in the onset of mammalian puberty.

236. Growth, Maturity and Injury Characteristics in Adolescent Male Soccer Players: A Cross-Sectional Study

The initiation and progression of puberty varies among adolescents. It is well known that the somatic, neurological and cognitive development of teenagers who engage in sports activities are positively influenced. In this study, the growth and maturity status and injury characteristics of adolescent male soccer players were compared with healthy peers.

Social control of spermatogenesis and steroidogenesis in cichlid fish: a comparative approach.

Social animals with hierarchical dominance systems are susceptible to changes their environment. Interactions with conspecifics can greatly affect individual's behavior and reproductive success. This review will show how social behavior modulates gonadal steroidogenesis and spermatogenesis in African and Neotropical cichlid fish with different social systems and how this modulation regulates reproductive capacity. Social behavior and aggressiveness are strongly linked to sex steroids, glucocorticoids and neuropeptides. The challenge hypothesis suggests that behavioral interactions increase androgen levels in response to social instability, but there is little evidence regarding estradiol levels. It has been recently demonstrated that in male Cichlasoma dimerus, a Neotropical cichlid fish, the challenge hypothesis could also be extended to estrogens. In C. dimerus, dominant males have higher gonadosomatic index than subordinated; the percentage of spermatocytes and spermatids is higher in subordinates, while dominants show a greater percentage of spermatozoa. In other species of African cichlids, socially suppressed subordinate males are not reproductively incompetent maintaining some activity at every level of their reproductive axis. Axis reactivation upon social ascent is similar to the initiation of puberty in mammals, as well as the reoccurrence of puberty observed in seasonally breeding animals. In conclusion, social behavior and reproductive strategies in females cichlids are still understudied, and Neotropical cichlids still constitute a group that deserves more attention, considering cichlids' diversity in mating systems, reproductive behavior and parental care. This review highlights the importance of performing further studies and additional research in these two areas, which still remain to be addressed.

Molecular and Environmental Mechanisms Regulating Puberty Initiation: An Integrated Approach.

The mechanisms underlying the initiation of puberty, one of the cornerstones of human evolution, have not been fully elucidated as yet. However, recently, an accumulating body of evidence has helped unravel several critical aspects of the process. It is clear that a change in the pattern of pituitary gonadotropin secretion serves as a hormonal trigger for puberty induction. This change is directly guided by the hypothalamic GnRH pulse generation, a phenomenon regulated by the Kisspeptin-Neurokinin-Dynorphin (KNDy) system also in the hypothalamus. This represents the kisspeptin molecule, which is crucial in augmenting GnRH secretion at puberty, whose secretion is fine-tuned by the opposing signals neurokinin B and dynorphin. Recently, the novel kisspeptin inhibitory signal MKRN3 was described, whose role in puberty initiation provided further insight into the mechanistic aspects of pubertal onset. Furthermore, the description of higher inhibitory and stimulatory signals acting upstream of the KNDy neurons suggested that the trigger point of puberty is located upstream of the KNDy system and the GnRH pulse generator. However, the mechanism of pubertal onset should not be considered as an isolated closed loop system. On the contrary, it is influenced by such factors as adipose tissue, gastrointestinal function, adrenal androgen production, energy sensing, and physical and psychosocial stress. Also, fetal and early life stressful events, as well as exposure to endocrine disruptors, may play important roles in pubertal initiation, the latter primarily through epigenetic modifications. Here we present the available data in the field and attempt to provide an integrated view of this unique and crucial phenomenon.

The role of kisspeptin system in cancer biology.

Kisspeptins are a family of neuropeptides that are known to be critical in puberty initiation and ovulation. Apart from that kisspeptin derived peptides (KPs) are also known for their antimetastatic activities in several malignancies. Herein we report recent evidence of the role of kisspeptins in cancer biology and we examine the prospective of targeting the kisspeptin pathways leading to a better prognosis in patients with malignant diseases.

Evolutionary Conservation of MKRN3 and Other Makorins and Their Roles in Puberty Initiation and Endocrine Functions.

Puberty is a critical period of development regulated by genetic, nutritional, and environmental factors. The role of makorin ring finger protein 3 (MKRN3) in the regulation of pubertal timing was revealed when loss-of-function mutations were identified in patients with central precocious puberty (CPP). To date, MKRN3 mutations are the most common known genetic cause of CPP. MKRN3 is a member of the makorin family of ubiquitin ligases, together with MKRN1 and MKRN2. The Mkrn genes have been identified in both vertebrates and invertebrates and show high evolutionary conservation of their gene and protein structures. While the existence of Mkrn orthologues in a wide spectrum of species suggests a vital cellular role of the makorins, their role in puberty initiation and endocrine functions is just beginning to be investigated. In this review, we discuss recent studies that have shown the involvement of Mkrn3 and other makorins in the regulation of pubertal development and other endocrine functions, including metabolism and fertility, as well as their underlying mechanisms of action.

Dynamic DNA methylation of ovaries during pubertal transition in gilts

BackgroundIn female mammals, the initiation of puberty, coupling with the dramatically morphological changes in ovaries, indicates the sexual and follicular maturation. Previous studies have suggested that the disrupted DNA methylation results in the delayed puberty. However, to date, the changes in ovarian methylomes during pubertal transition have not been investigated. In this study, using gilts as a pubertal model, the genome-wide DNA methylation were profiled to explore their dynamics during pubertal transition across Pre-, In- and Post-puberty.ResultsDuring pubertal transition, the follicles underwent maturation and luteinization, coupled with the significant changes in the mRNA expression of DNMT1 and DNMT3a. DNA methylation levels of In-puberty were higher than that of Pre- and Post-puberty at the locations of genes and CpG islands (CGIs). Analysis of the DNA methylation changes identified 12,313, 20,960 and 17,694 differentially methylated CpGs (DMCs) for the comparisons of Pre- vs. In-, In vs. Post-, and Pre- vs. Post-puberty, respectively. Moreover, the CGIs, upstream and exonic regions showed a significant underrepresentation of DMCs, but the CGI shores, CGI shelves, intronic, downstream and intergenic regions showed a significant overrepresentation of DMCs. Furthermore, biological functions of these methylation changes enriched in PI3K-Akt signaling pathway, GnRH signaling pathway, and Insulin secretion, and the mRNA expressions of several genes of these signaling pathway, including MMP2, ESR1, GSK3B, FGF21, IGF1R, and TAC3, were significantly changed across Pre-, In- and Post-puberty in ovaries.ConclusionsDuring pubertal transition in gilts, the DNA methylation changes of ovaries were likely to affect the transcription of genes related to PI3K-Akt signaling pathway, GnRH signaling pathway, and Insulin secretion. These observations can provide new insight into the epigenetic mechanism of follicular and sexual maturation during pubertal transition in mammals.

The initiation of puberty in Atlantic salmon brings about large changes in testicular gene expression that are modulated by the energy status

BackgroundWhen puberty starts before males reach harvest size, animal welfare and sustainability issues occur in Atlantic salmon (Salmo salar) aquaculture. Hallmarks of male puberty are an increased proliferation activity in the testis and elevated androgen production. Examining transcriptional changes in salmon testis during the transition from immature to maturing testes may help understanding the regulation of puberty, potentially leading to procedures to modulate its start. Since differences in body weight influence, via unknown mechanisms, the chances for entering puberty, we used two feed rations to create body weight differences.ResultsMaturing testes were characterized by an elevated proliferation activity of Sertoli cells and of single undifferentiated spermatogonia. Pituitary gene expression data suggest increased Gnrh receptor and gonadotropin gene expression, potentially responsible for the elevated circulating androgen levels in maturing fish. Transcriptional changes in maturing testes included a broad variety of signaling systems (e.g. Tgfβ, Wnt, insulin/Igf, nuclear receptors), but also, activation of metabolic pathways such as anaerobic metabolism and protection against ROS. Feed restriction lowered the incidence of puberty. In males maturing despite feed restriction, plasma androgen levels were higher than in maturing fish receiving the full ration. A group of 449 genes that were up-regulated in maturing fully fed fish, was up-regulated more prominently in testis from fish maturing under caloric restriction. Moreover, 421 genes were specifically up-regulated in testes from fish maturing under caloric restriction, including carbon metabolism genes, a pathway relevant for nucleotide biosynthesis and for placing epigenetic marks.ConclusionsUndifferentiated spermatogonia and Sertoli cell populations increased at the beginning of puberty, which was associated with the up-regulation of metabolic pathways (e.g. anaerobic and ROS pathways) known from other stem cell systems. The higher androgen levels in males maturing under caloric restriction may be responsible for the stronger up-regulation of a common set of (449) maturation-associated genes, and the specific up-regulation of another set of (421) genes. The latter opened regulatory and/or metabolic options for initiating puberty despite feed restriction. As a means to reduce the incidence of male puberty in salmon, however, caloric restriction seems unsuitable.

OR08-3 The Role Of Neuronal Plasticity In The Timing Of Puberty Onset: Insights From A Mkrn3 Deficient Mouse Model.

Makorin ring finger protein 3 (MKRN3) was identified as a regulator of puberty initiation with the report of loss-of-function mutations in association with central precocious puberty (CPP). MKRN3 is a maternally imprinted gene located on chromosome 15q11.2 in humans. In juvenile mice, Mkrn3 is highly expressed in the preoptic area and the arcuate nucleus of the hypothalamus, with a decrease in expression before puberty initiation. Together, these findings suggest an inhibitory role of MKRN3 on GnRH secretion during the prepubertal quiescent period. MKRN3 contains a RING finger motif and several zinc finger motifs, suggesting E3 ubiquitin ligase and RNA binding activities, respectively. To date, the mechanisms of action of MKRN3 in puberty initiation remain unknown. In this study, we used a Mkrn3 deficient mouse model to identify hypothalamic targets of MKRN3’s inhibitory effects. By Western blot and immunohistochemistry, we confirmed that Mkrn3 protein was undetectable in Mkrn3+/- mice (which inherited the mutant allele from their father), but present in wildtype (Mkrn3+/+) mice. Mkrn3 deletion was associated with accelerated puberty onset in female mice and a trend towards early puberty onset in male mice, as shown by an advanced day of female first estrus and a trend towards earlier age of male preputial separation in Mkrn3 deficient (Mkrn3+/-) compared to Mkrn3+/+animals. Hypothalamic mRNA levels of Gnrh1, Kiss1, Tac2 and Tac1, regulators of pubertal initiation, were measured by RT-qPCR in females at different ages across postnatal development (postnatal day (PND)10, PND15, PND20 and PND25). No significant difference was found in Gnrh1 and Kiss1 expression in the preoptic area, nor in Kiss1, Tac2 and Tac1 expression in the arcuate nucleus, between Mkrn3+/+ and Mkrn3+/- mice, at any of the postnatal day ages tested. Thus, to further investigate possible targets of MKRN3 action using an unbiased approach, we compared the transcriptome (via RNA-sequencing) and proteome (via Tandem Mass Tagging (TMT) method) of the arcuate nucleus of Mkrn3+/+ and Mkrn3+/- female mice at PND15. These analyses revealed differences in gene or protein expression between Mkrn3+/+ and Mkrn3+/- animals in factors involved in extracellular matrix organization, cell adhesion, and axon guidance pathways, which together control neuronal development and synaptic plasticity. These findings suggest that Mkrn3 may be important as a postnatal/prepubertal regulator of hypothalamic neuronal plasticity in mice. In humans, puberty has been shown to be a critical time window of neuronal plasticity. Thus, understanding the involvement of MKRN3 in these processes will provide new insights into pubertal disorders such as CPP and delayed puberty, and may lead to the development of new treatment strategies.

SUN-LB047 Two Unusual Cases of Pituitary Tumors Presenting with Acromegaly

Introduction: Acromegaly is a rare pituitary disorder. Only seen 1-2 times in most endocrinologist careers. In one study, 0.6% of the cases of pituitary adenomas had pituitary gigantism. Most of what is known is from isolated case reports in the adult population. Over 95% of patients with acromegaly have a growth hormone secreting pituitary adenoma. Case 1: A 16-year-old female presented for evaluation of primary amenorrhea. Initiation of puberty was at 12. She was very tall for age. Mom reported a rapid growth after the age of 9. Her height was at the 95th percentile while her target height was at the 50th percentile. On exam, she had coarse facial features and large hands and feet. Initial evaluation revealed a serum prolactin of 8.5 ng/ml, LH 0.1 IU/L (L), free testosterone 2.1 ng/dl, total testosterone 10.01 ng/dl, GH 7.03 ng/ml (H), IGF-1 at 1162 ng/ml (H) and normal TFTs. Growth hormone suppression test confirmed growth hormone excess. The lowest growth hormone level was 4.1 ng/ml at 30 minutes after a 75 gm load of glucose. An MRI of the pituitary gland revealed a 1.9 x 1.3 x 1.3 cm lobular mass within the sella and suprasellar region, with some displacement of the pituitary stalk and optic chiasm. She successfully underwent transphenoidal resection of the pituitary mass. After surgery: She presented with DI post operatively that has resolved. Normal cortisol levels. She has secondary hypothyroidism and is on levothyroxine. IGF-1 started dropping 4 days post-op (738mg/ml) and normalized 2 months later (373 ng/ml) 22 months post op: cortisol and IGF-1 are normal. No evidence of DI. She remains on levothyroxine and is on an estradiol patch. Case 2: A 15-year-old girl presented for evaluation of irregular periods. On exam, she had coarse facial features, large hands and feet, acanthosis nigricans, hirsutism and a deep voice. Height was at the 50th percentile with MPH at the 25th percentile. Initial evaluation revealed a very elevated serum prolactin of 260 ng/dL. Serum LH was low at 0.14 mIU/ml, free testosterone was elevated at 5.6 pg/mL. She had mixed hyperlipidemia. TFTs were normal. Repeat labs confirmed hyperprolactinemia and she was started on carbergoline. Further evaluation revealed an elevated IGF-I level at 1374 ng/mL (208-619), elevated IGFBP-3 of 11.2 mg/L (3.4-9.5) with a normal cortisol and serum sodium. Growth hormone suppression test confirmed excessive growth hormone production with the lowest growth hormone level being 11.7 ng/mL 120 minutes after 75 gm load of glucose. An MRI of the pituitary gland revealed a pituitary macroadenoma measuring 1.7 x 1.5 x 2 cm invading into the cavernous sinus and wrapping around the ICA. She successfully underwent trans-sphenoidal resection of the pituitary mass and is post op. Conclusion: Acromegaly is rare in children and may present with unusual symptoms of other pituitary hormone dysfunction. Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. s presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.

Endocrine patterns associated with puberty in male and female cattle

In four studies secretion patterns of LH, FSH, prolactin, testosterone and progesterone were measured in male and female cattle to determine endocrine changes associated with sexual maturation. Two periods of increasing gonadotrophin secretion were observed, the second one coinciding with puberty. A short luteal phase of 8-12 days precedes the first oestrus at 10-11 or 14 months of age. The testosterone values of the bulls increased with age from 5-6 months. Prolactin levels in the bulls increased at the time of the first testosterone rise. A frequency of about 1-2 LH and FSH pulses/8 h occurred at 1, 2, 5 and 10 months of age. The pituitary response to GnRH (1 microgram/kg i.v.) was tested in 2 male and 2 female calves at monthly intervals. LH and FSH were released at all ages but a reduced FSH response occurred in both sexes after the 5th month. A small testosterone release was observed as early as 1 month after birth in males similar to those observed after endogenous LH pulses. We conclude that the initiation of puberty in both sexes is controlled by the same neuroendocrine mechanisms. The pituitary gland, ovaries and testes are already able to respond to specific stimuli long before puberty, and they may also be involved indirectly due to changes in the feedback system modulating gonadotrophin secretion.

Genome-wide DNA methylation analysis of pituitaries during the initiation of puberty in gilts.

It has been widely recognized that the early or delayed puberty appears to display harmful effects on adult health outcomes. During the timing of puberty, pituitaries responds to the hypothalamus and then introduce the following response of ovaries in hypothalamic-pituitary-gonadal axis. DNA methylation has been recently suggested to regulate the onset of puberty in female mammals. However, to date, the changes of DNA methylation in pituitaries have not been investigated during pubertal transition. In this study, using gilts as the pubertal model, the genome-scale DNA methylation of pituitaries was profiled and compared across Pre-, In- and Post-puberty by using the reduced representation bisulfite sequencing. We found that average methylation levels of each genomic feature in Post- were lower than Pre- and In-pubertal stage in CpG context, but they were higher in In- than that in Pre- and Post-pubertal stage in CpH (where H = A, T, or C) context. The methylation patterns of CpHs were more dynamic than that of CpGs at the location of high CpG content, low CpG content promoter genes, and differently genomic CGIs. Furthermore, the differently genomic CGIs were likely to show in a similar manner in CpG context but display in a stage-specific manner in the CpH context across the Pre-, In- and Post-pubertal stage. Among these pubertal stages, 5 kb upstream regions of the transcription start sites were protected from both CpG and CpH methylation changes. 12.65% of detected CpGs were identified as the differentially methylated CpGs, regarding 4301 genes which were involved in the fundamental functions of pituitaries. 0.35% of detected CpHs were identified as differentially methylated CpHs, regarding 3691 genes which were involved in the biological functions of releasing gonadotropin hormones. These observations and analyses would provide valuable insights into epigenetic mechanism of the initiation of puberty in pituitary level.

MKRN3 Interacts With Several Proteins Implicated in Puberty Timing but Does Not Influence GNRH1 Expression.

Paternally-inherited loss-of-function mutations in makorin ring finger protein 3 gene (MKRN3) underlie central precocious puberty. To investigate the puberty-related mechanism(s) of MKRN3 in humans, we generated two distinct bi-allelic MKRN3 knock-out human pluripotent stem cell lines, Del 1 and Del 2, and differentiated them into GNRH1-expressing neurons. Both Del 1 and Del 2 clones could be differentiated into neuronal progenitors and GNRH1-expressing neurons, however, the relative expression of GNRH1 did not differ from wild type cells (P = NS). Subsequently, we investigated stable and dynamic protein-protein interaction (PPI) partners of MKRN3 by stably expressing it in HEK cells followed by mass spectrometry analyses. We found 81 high-confidence novel protein interaction partners, which are implicated in cellular processes such as insulin signaling, RNA metabolism and cell-cell adhesion. Of the identified interactors, 20 have been previously implicated in puberty timing. In conclusion, our stem cell model for generation of GNRH1-expressing neurons did not offer mechanistic insight for the role of MKRN3 in puberty initiation. The PPI data, however, indicate that MKRN3 may regulate puberty by interacting with other puberty-related proteins. Further studies are required to elucidate the possible mechanisms and outcomes of these interactions.