Pubertal development and regulation

NAGK regulates the onset of puberty in female mice

This study examines the role of N-acetylglucosamine kinase (NAGK) in initiating puberty in female mice. We employed real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) and immunofluorescence to measure NAGK expression in the hypothalamic-pituitary-ovarian axis across various developmental stages: infant, prepuberty, puberty, and adult. We further investigated the impact of Nagk gene knockdown on puberty in female mice. This included assessing the expression of puberty-related genes both in vivo and in vitro, GT1-7 cells proliferation and apoptosis, concentrations of GnRH and Kisspeptin, puberty onset timing, serum levels of progesterone (P4) and estradiol (E2), and ovarian morphology. Results revealed that Nagk mRNA is present in the hypothalamus, pituitary, and ovaries throughout different developmental stages in female mice. In the hypothalamus, Nagk mRNA levels were comparable during infant and prepuberty, lowest during puberty, and highest in adult. In the pituitary, Nagk mRNA peaked in adult, with no significant variation between infant, prepuberty, and puberty. In the ovaries, Nagk mRNA levels increased during puberty and peaked in adult. NAGK is predominantly located in the arcuate nucleus (ARC), periventricular nucleus (PeN), dorsomedial hypothalamic nucleus (DMH), paraventricular nucleus (PVN), adenohypophysis, and in the ovarian oocytes, interstitium, and granulosa cells across all developmental stages in female mice. Nagk knockdown in GT1-7 cells decreased the transcriptional level of Gnrh, Kiss1, Gpr54, Igf1 and Mapk14 mRNA and cell proliferation but increased the level of β-catenin mRNA and cell apoptosis, while reducing GnRH secretion. Following ICV injection, Nagk gene knockdown mice exhibited delayed the timing of vaginal opening (VO) and reduced hypothalamic levels of Gnrh, Kiss1, Gpr54, Igf1, Mapk14, and β-catenin mRNA. Additionally, serum concentrations of E2 in Nagk gene knockdown mice were significantly lower compared to the control group. These findings indicate that Nagk regulates the expression of Gnrh and Kiss1 mRNA in GT1-7 cells, affects hypothalamus Gnrh mRNA levels and serum E2 concentration, and that its knockdown can delay puberty onset in female mice.

[Application of urinary luteinizing hormone in the prediction of central precocious puberty in girls]

OBJECTIVE

To evaluate the level of first morning voided (FMV) urinary luteinizing hormone (LH) in girls with breast development, and to determine the value of FMV urine LH in the evaluation of central precocious puberty (CPP).

METHODS

From September 2018 to April 2021, among the patients who were admitted to the Department of Pediatrics of Peking University Third Hospital for "precocious puberty" and underwent gonadotropin-releasing hormone (GnRH) stimulation test, a total of 108 girls were enrolled. According to CPP diagnostic criteria, they were divided into CPP group (n=45) and non-CPP group (n=63). The clinical characteristics and hormone levels of the two groups were compared. Receiver operating characteristic (ROC) curve was used to analyze the cut-off value of FMV urinary LH in the diagnosis of CPP in girls. Further analyses were done to evaluate the value of FMV urinary LH in the diagnosis of CPP using correlation analysis between urinary LH level and common clinical cha-racteristics.

RESULTS

ROC curve analysis showed that FMV urine LH level was significant for the diagnosis of CPP. The cut-off value of FMV urine LH was 0.69 IU/L (specificity 56.9%, sensitivity 85.0%, area under curve 0.804, P < 0.001). The basic clinical characteristics without GnRH stimulation test were analyzed by binary Logistic regression analysis, indicating that the level of FMV urine LH, uterine volume, ovarian volume and advanced T-bone age had predictive significance for CPP diagnosis in girls (OR values were 2.125, 1.961, 1.564 and 2.672, respectively). The prediction model was established and the area under the ROC curve was 0.904, P < 0.001. The level of FMV urine LH was positively correlated with the levels of serum LH, FSH and estrogen before GnRH stimulation test, the peak value of blood LH after GnRH stimulation test, T bone age and uterine volume, with r values of 0.462, 0.373, 0.242, 0.360, 0.373 and 0.263, respectively, and P values were < 0.001, < 0.001, 0.013, < 0.001, < 0.001 and 0.007, respectively.

CONCLUSION

FMV urine LH can provide a good indication for the diagnosis of CPP. Combining with bone age advanced level and pelvic ultrasound measurement, the predictive value of FMV urine LH can be further improved for the diagnosis of CPP in girls.

ADHD and Risk of Precocious Puberty: Considering the Impact of MPH

BACKGROUND/OBJECTIVES

The complex association between attention-deficit/hyperactivity disorder (ADHD) and methylphenidate (MPH) with precocious puberty (PP) is still unclear. This study aims to investigate the association between ADHD, MPH, and PP.

METHODS

This is a nationwide cohort study including a total of 3,342,077 individuals, 186,681 with ADHD and 3,155,396 without. First, we compared the risk of PP between ADHD cases and non-ADHD cases. Second, we compared the risk of PP between MPH users and non-MPH users in patients with ADHD.

RESULTS

Patients with ADHD were at a greater risk of PP (adjusted hazard ratio [aHR], 2.01 [95% CI, 1.91-2.11]). In our moderation analyses, the female gender was a positive additive effect modifier of the association between ADHD and PP, whereas tics and intellectual disability were negative effect modifiers. In patients with ADHD, MPH users had a significantly lower risk of PP (aHR, 0.63 [95% CI 0.57-0.70]), and females had a negative effect modification on the association between MPH and PP.

CONCLUSIONS

Our study found that children with ADHD were at a greater risk of PP. Girls with ADHD were a group particularly vulnerable to PP. Comorbid tics or intellectual disability was associated with a lower risk of PP. Among patients with ADHD, MPH was protective against PP, especially in girls. However, these preliminary results need further validation due to the nature of them being from an electronic database study. Unmeasured confounding factors might affect the association between MPH and PP.

The enduring effects of antimicrobials and lipopolysaccharide on the cellular mechanisms and behaviours associated with neurodegeneration in pubertal male and female CD1 mice

Puberty is a sensitive developmental period during which stressors can cause lasting brain and behavioural deficits. While the acute effects of pubertal lipopolysaccharide (LPS) and antimicrobial (AMNS) treatments are known, their enduring impacts on neurodegeneration-related mechanisms and behaviours remain unclear. This study examined these effects in male and female mice. At five weeks old, mice received 200ul of either broad-spectrum antimicrobials or water through oral gavage twice daily for seven days. At six weeks of age, they received an intraperitoneal injection of either saline or LPS. Four weeks later, adult mice underwent neurodegeneration-related behavioural tests, including the rotarod, forepaw stride length, reversed grid hang, open field, and buried pellet tests. Two days after the final test, brain and ileal samples were collected. Results showed that female mice treated with both AMNS and LPS exhibited deficits in neuromuscular strength, while males treated with LPS alone showed increased anxiety-like behaviours. Males treated with AMNS alone had decreased sigma-1 receptor (S1R) expression in the cornu ammonis 1 (CA1) and dentate gyrus (DG), while females treated with both AMNS and LPS had decreased S1R expression. Additionally, males treated with either LPS or AMNS had lower glial-derived neurotrophic factor receptor alpha-1 (GFRA1) expression in the primary motor cortex (M1) than females. Mice treated with LPS alone had decreased GFRA1 expression in the DG and decreased S1R expression in the secondary motor cortex (M2). These findings suggest that pubertal AMNS and LPS treatments may lead to enduring changes in biomarkers and behaviours related to neurodegeneration.

Associations between birthweight and preterm birth and the ages at menarche and menopause

BACKGROUND

Women who reach menarche and menopause at earlier ages have been shown to be at increased risk for numerous conditions including cardiovascular disease, cancer, depression, and obesity; however, risk factors for earlier ages of menarche and menopause are not fully understood. Therefore, we aimed to perform a retrospective investigation of the associations between a personal birthweight and/or being born preterm and the age of and menarche and menopause and related events in the Women's Health Initiative, a large, racially and ethnically diverse cohort of postmenopausal women.

METHODS

At study entry, women reported their birthweight by category (< 6 lbs., 6-7 lbs. 15 oz, 8-9 lbs. 15 oz, or ≥ 10 lbs.) and preterm birth status (4 or more weeks premature). Ages at events related to menarche and menopause were also self-reported. Linear regression and logistic regression models were used to estimate unadjusted and adjusted effect estimates (β) and odds ratios (OR), respectively (n ≤ 86,857). Individuals born preterm were excluded from all birthweight analyses.

RESULTS

After adjustments, individuals born weighing < 6lbs. were more likely to reach natural menopause at an earlier age (adjusted β=-0.361, SE = 0.09, P = < 0.001) and have a shorter reproductive window (adjusted β = -0.287, SE = 0.10, p < 0.004) compared to individuals weighing 6-7 lbs. 15 oz. Individuals born preterm were also more likely to reach natural menopause at an earlier age (adjusted β=-0.506, SE = 0.16, P = 0.001) and have a shorter reproductive window (adjusted β = -0.418, SE = 0.17, p < 0.006).

CONCLUSIONS

These findings raise concerns that, as more preterm and low birthweight individuals survive to adulthood, the prevalence of earlier-onset menarche and menopause may increase. Clinical counseling and interventions aimed at reducing the incidence of preterm and low birthweight births, as well as intensification of lifestyle modifications to reduce CVD risk among women with these early-life risk factors, should be prioritized.

Maternal stress in pregnancy and pubertal timing in girls and boys: a cohort study

OBJECTIVE

To investigate whether maternal stress in pregnancy is associated with pubertal timing in girls and boys and to explore potential mediation by childhood body mass index (BMI) and childhood psychosocial stress.

DESIGN

Cohort study.

SETTING

Not applicable.

PATIENTS

In total, 14,702 girls and boys from the Puberty Cohort, nested within the Danish National Birth Cohort.

INTERVENTION

Maternal stress was obtained from a computer-assisted telephone interview in gestational weeks 30-32 as maternal life stress and emotional distress in pregnancy using questions on the basis of validated screening tools. Maternal life stress and emotional distress in pregnancy were analyzed separately and in an interaction analysis.

MAIN OUTCOME MEASURES

Pubertal timing was measured half-yearly from age 11 years and throughout pubertal development and assessed as Tanner stages 1-5 (breast and pubic hair development in girls and genital and pubic hair development in boys), menarche in girls, voice break and first ejaculation in boys, and occurrence of acne and axillary hair in both girls and boys. A combined estimate for overall pubertal timing was derived using Huber-White robust variance estimation. Mean differences in age at attaining the pubertal milestones according to prenatal exposure to no (reference), low-, moderate-, or high-maternal stress in pregnancy were estimated using a multivariable censored regression model. Potential mediation by childhood BMI and childhood psychosocial stress was investigated in separate models.

RESULTS

After adjustment for potential confounding factors, prenatal exposure to high-maternal life stress (combined estimate: -1.8 months [95% CI, -2.7 to -0.8] and -0.9 months [95% CI, -1.8 to 0.0]), high maternal emotional distress (combined estimate: -1.5 months [95% CI, -2.5 to -0.5] and -1.7 months [95% CI, -2.8 to -0.7]), and both high-maternal life stress and emotional distress (combined estimate: -2.8 months [95% CI, -4.2, to -1.4] and -1.7 months [95% CI, -3.1 to -0.2]) were associated with earlier pubertal timing in girls and boys, respectively. The associations were not mediated by childhood BMI or childhood psychosocial stress.

CONCLUSIONS

Prenatal exposure to maternal stress in pregnancy was associated with earlier pubertal timing in girls and boys in a dose-dependent manner. The associations were not mediated by childhood BMI or childhood psychosocial stress.

The Dynamic Interplay Between Puberty and Structural Brain Development as a Predictor of Mental Health Difficulties in Adolescence: A Systematic Review

Puberty is a time of intense reorganization of brain structure and a high-risk period for the onset of mental health problems, with variations in pubertal timing and tempo intensifying this risk. We conducted 2 systematic reviews of articles published up to February 1, 2024, focusing on 1) the role of brain structure in the relationship between puberty and mental health, and 2) precision psychiatry research evaluating the utility of puberty in making individualized predictions of mental health outcomes in young people. The first review provides inconsistent evidence about whether and how pubertal and psychopathological processes may interact in relation to brain development. While most studies found an association between early puberty and mental health difficulties in adolescents, evidence on whether brain structure mediates this relationship is mixed. The pituitary gland was found to be associated with mental health status during this time, possibly through its central role in regulating puberty and its function in the hypothalamic-pituitary-gonadal and hypothalamic-pituitary-adrenal axes. In the second review, the design of studies that have explored puberty in predictive models did not allow for a quantification of its predictive power. However, when puberty was evaluated through physically observable characteristics rather than hormonal measures, it was more commonly identified as a predictor of depression, anxiety, and suicidality in adolescence. Social processes may be more relevant than biological ones to the link between puberty and mental health problems and represent an important target for educational strategies.

Sibling relatedness and pubertal development in girls and boys: A population-based cohort study

PURPOSE

To investigate the association between sibling relatedness and pubertal development in girls and boys.

METHODS

This cohort study consisted of 10,657 children from the Puberty Cohort, Denmark. Information on sibling relatedness was obtained by self-report. Information on pubertal markers was obtained half yearly from age 11 and throughout puberty. Mean age difference at attaining pubertal markers was estimated using interval-censored regression models according to sibling relatedness (full, half and/or step siblings; half and/or step siblings; no siblings; relative to full siblings).

RESULTS

Girls with both full, half and/or step siblings (-1.2 (CI 95 %: -2.5; 0.1) months), only half- and/or stepsiblings (-2.2 (CI 95 %: -3.7; -0.7) months), and no siblings (-5.5 (CI 95 %: -8.5; -2.5) months) entered puberty earlier than girls with full siblings. Boys with full, half and/or step siblings (-1.4 (CI 95 %: -2.7; -0.1) months), only half and/or step siblings (-1.2 (CI 95 %: -3.0; 0.6) months), and no siblings (-4.5 (CI 95 %: -8.8; -0.3) months) entered puberty earlier than boys with full siblings.

CONCLUSIONS

Children with sibling relatedness other than full siblings entered puberty earlier than their peers with full siblings even after adjustment for parental cohabitation status, childhood body mass index and childhood internalizing and externalizing symptoms.

Potential Role of Sleep Disturbance in the Development of Early Puberty: Past Clinical Evidence for Future Management

The incidence of early puberty in children has been increasing. It has been suspected that both genetic and various environmental factors such as nutrition and hormonal exposure could influence the mechanisms underlying the earlier onset of puberty. Interestingly, several previous studies have reported a strong connection between sleep and puberty. Specifically, it was discovered that luteinizing hormone (LH), a potential marker for the onset of puberty, was increased during the deep sleep period. Furthermore, a high prevalence of early puberty was observed in patients with sleep disorders, especially in those experiencing narcolepsy. In this review article, findings related to the association between sleep disturbance and early puberty have been comprehensively summarized. Any contrary findings are also included and discussed. Advances in the knowledge surrounding sleep disturbance have led to a greater understanding of a correlation between early puberty and sleep disorder and provide alternative therapeutic options for the treatment of central precocious puberty in the future.

Geneenvironment interaction between phthalate exposure and pubertal genetic polymorphisms on blood pressure variability in children: Exploring the moderating effects of lifestyle behaviours

Phthalates (PAEs) are synthetic compounds extensively employed in consumer products. Blood pressure (BP) in children can vary, the degree of visit-to-visit BP variability (VVV) is at least partially independent of BP. The interactions between PAEs exposure, pubertal-related genetic susceptibility and lifestyles on childhood VVV are not investigated. This study utilized data from a cohort collected from Oct 2017-2020 in Xiamen, China. Seven urine PAE metabolites were measured. The long-term VVV was characterized employing the standard deviation (SD) and average real variability. We constructed a genetic risk score (GRS) of pubertal-related genes and healthy lifestyle scores. Exposed to high levels of mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP) (OR=1.43, 95 %CI=1.07, 1.92) and mono-2-ethyl-5-oxohexyl phthalate (OR=1.36, 95 % CI=1.01, 1.83) was related to increased SBP-SD, and the OR for high SBP-SD related to high GRS was 1.38 (95 % CI=1.02, 1.85). Compared to participants who had low GRS and low MEHHP exposure, participants exhibiting high GRS and MEHHP levels were more likely to experience high SBP-SD (OR=2.00, P<0.05). Individuals exhibiting low GRS, low MEHHP levels, and adhering to healthy lifestyles were associated with the least probability of experiencing high SBP-SD (OR=0.31, P<0.05). Increased PAEs exposure could elevate childhood systolic VVV, and exacerbated the adverse impact of pubertal-related genetic susceptibility on the high VVV of SBP; however, healthy lifestyles might alleviate these adverse effects. Promoting healthy lifestyles and reducing PAEs exposure for preventing elevated BP variability among children is important, especially for individuals with greater genetic susceptibility to early pubertal onset. ENVIRONMENTAL IMPLICATION: Blood pressure (BP) in children can vary, as a noninvasive, inexpensive and applicable method, the extent of visit-to-visit variability (VVV) is at least partially independent of BP. The interactions between phthalates (PAEs) exposure, variants of puberty-related genes and lifestyles on VVV are not investigated. Increased childhood systolic VVV might be associated with PAEs exposure, with the associations more pronounced combined with pubertal genetic susceptibility. Yet, healthy habits could partly eliminate such adverse effects. Our study underscores the importance of advocating for healthy lifestyles and reducing exposure to PAEs, especially among individuals with high genetic susceptibility to early puberty onset.

Pharmacogenomics and pediatric drug development: science and political power. A narrative review

INTRODUCTION

Pharmacogenomics (PGx) investigates how genomes control enzyme expression. Developmental pharmacology (DP) describes the temporal sequence of enzymes impacting absorption, distribution, metabolism, and excretion (ADME) of food and drugs.

AREAS COVERED

US and European Union (EU) legislation facilitate and/or enforce pediatric studies for all new drugs, called overall 'pediatric drug development' (PDD). DP and PDD look at patients' chronological age, but oscillate between legal and physiological meanings of the term 'child.' Children's bodies become mature with puberty.

EXPERT OPINION

Decades after first DP observations in babies, PGx offers a better understanding of the variability of safety and efficacy of drugs, of the process of aging, and of shifting enzyme patterns across aging. We should rethink and revise outdated interpretations of ADME changes in minors. The Declaration of Helsinki forbids pointless studies that some pediatric researchers and regulatory agencies, more so the EMA than the FDA, demand pointless pediatric studies is regrettable. Medicine needs to differentiate between legal and physiological meanings of the term 'child' and should use objective measures of maturity.

Early puberty: a review on its role as a risk factor for metabolic and mental disorders

Accumulating evidence indicates that there is a trend of early puberty onset in humans. The early timing of puberty has raised concerns due to its association with significant negative health outcomes. However, overall impact and potential risk of early puberty remain uncertain. In this study, we conducted a comprehensive review of existing epidemiological studies to gain insights into the long-term adverse health effects associated with early puberty. Our objective was to provide a consolidated summary of these outcomes at a population level by considering studies that encompass various indicators of puberty. In all, early puberty has been identified as a potential risk factor for various metabolic diseases, such as obesity, diabetes, cardiovascular diseases (CVD). Children who experience early puberty are more likely to have a higher body mass index (BMI) during adulthood, increasing their risk of obesity. Early puberty also has been found to be an independent risk factor for diabetes mellitus, including gestational diabetes mellitus (GDM) and type 2 diabetes mellitus (T2DM), as earlier onset of menarche in girls and voice breaking in boys is associated with a higher prevalence of T2DM. Furthermore, evidence suggests that early puberty may contribute to an elevated risk of CVD, including conditions like coronary heart disease (CHD), stroke, angina, and hypertension. In addition, adolescents who experience early puberty, particularly girls, are more likely to suffer from mental problems, such as behavioral dysfunction and depression. Notably, early puberty has a more significant impact on girls than boys. Further research should consider the underlying mechanisms and potential preventive measures.

Effects of Heat Stress-Induced Sex Hormone Dysregulation on Reproduction and Growth in Male Adolescents and Beneficial Foods

Heat stress due to climate warming can significantly affect the synthesis of sex hormones in male adolescents, which can impair the ability of the hypothalamus to secrete gonadotropin-releasing hormone on the hypothalamic-pituitary-gonadal axis, which leads to a decrease in luteinizing hormone and follicle-stimulating hormone, which ultimately negatively affects spermatogenesis and testosterone synthesis. For optimal spermatogenesis, the testicular temperature should be 2-6 °C lower than body temperature. Heat stress directly affects the testes, damaging them and reducing testosterone synthesis. Additionally, chronic heat stress abnormally increases the level of aromatase in Leydig cells, which increases estradiol synthesis while decreasing testosterone, leading to an imbalance of sex hormones and spermatogenesis failure. Low levels of testosterone in male adolescents lead to delayed puberty and incomplete sexual maturation, negatively affect height growth and bone mineral density, and can lead to a decrease in lean body mass and an increase in fat mass. In order for male adolescents to acquire healthy reproductive capacity, it is recommended to provide sufficient nutrition and energy, avoid exposure to heat stress, and provide foods and supplements to prevent or repair testosterone reduction, germ cell damage, and sperm count reduction caused by heat stress so that they can enter a healthy adulthood.

Menstrual Dysfunction in Adolescent Female Athletes

Despite the benefits of exercise on mental and physical health, excessive training loads can lead to health problems in the long term, including a wide spectrum of menstrual dysfunction (MD). This narrative review aims to analyze the relationship between physical exercise and MD in adolescent female athletes to support regular menstrual health monitoring and promote educational programs on reproductive risks. When dealing with MD in young athletes, several factors entangled with maturation of the hypothalamus-pituitary-ovarian axis should be considered. Firstly, some disciplines seem to have a higher prevalence of MD due to the high loads of training regimes and the early introduction of athletes to a competitive career. Moreover, low energy intake and a low body mass index appear to exacerbate existing MD. Lastly, disordered eating behaviors and psychological stress can contribute to MD in female athletes. The type of sport, influencing the intensity and duration of exercise, as well as individual psycho-physiological and environmental factors, may influence the role of physical activity in the manifestation of MD. Early recognition and management of MD, along with collaboration between sports organizations and health professionals, are crucial to minimize risks, ensure proper nutrition, and balance training with recovery. Keeping an open discussion on the topic may prospectively improve awareness, early diagnosis, and treatment strategies, as well as reduce injury risk and enhance sports performance.

Transcriptome analysis reveals miRNA expression profiles in hypothalamus tissues during the sexual development of Jining grey goats

BACKGROUND

Exploring the physiological and molecular mechanisms underlying goat sexual maturation can enhance breeding practices and optimize reproductive efficiency and is therefore substantially important for practical breeding purposes. As an essential neuroendocrine organ in animals, the hypothalamus is involved in sexual development and other reproductive processes in female animals. Although microRNAs (miRNAs) have been identified as significant regulators of goat reproduction, there is a lack of research on the molecular regulatory mechanisms of hypothalamic miRNAs that are involved in the sexual development of goats. Therefore, we examined the dynamic changes in serum hormone profiles and hypothalamic miRNA expression profiles at four developmental stages (1 day (neonatal, D1, n = 5), 2 months (prepubertal, M2, n = 5), 4 months (sexual maturity, M4, n = 5), and 6 months (breeding period, M6, n = 5)) during sexual development in Jining grey goats.

RESULTS

Transcriptome analysis revealed 95 differentially expressed miRNAs (DEMs) in the hypothalamus of goats across the four developmental stages. The target genes of these miRNAs were significantly enriched in the GnRH signalling pathway, the PI3K-Akt signalling pathway, and the Ras signalling pathway (P < 0.05). Additionally, 16 DEMs are common among the M2 vs. D1, M4 vs. D1, and M6 vs. D1 comparisons, indicating that the transition from D1 to M2 represents a potentially critical period for sexual development in Jining grey goats. The bioinformatics analysis results indicate that miR-193a/miR-193b-3p-Annexin A7 (ANXA7), miR-324-5p-Adhesion G protein-coupled receptor A1 (ADGRA1), miR-324-3p-Erbb2 receptor tyrosine kinase 2 (ERBB2), and miR-324-3p-Rap guanine nucleotide exchange factor 3 (RAPGEF3) are potentially involved in biological processes such as hormone secretion, energy metabolism, and signal transduction. In addition, we further confirmed that miR-324-3p targets the regulatory gene RAPGEF3.

CONCLUSION

These results further enrich the expression profile of hypothalamic miRNAs in goats and provide important insights for studying the regulatory effects of hypothalamic miRNAs on the sexual development of goats after birth.

Effects of chronic exposure to a high fat diet, nutritive or non-nutritive sweeteners on hypothalamic-pituitary-adrenal (HPA) and -gonadal (HPG) axes of male Sprague-Dawley rats

PURPOSE

Diet-related factors are of great significance in the regulation of hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-gonad (HPG) axes. In this study, we aimed to investigate the effects of chronic exposure to a high fat diet (HFD), fructose or sucralose on the endocrine functions.

METHODS

Male, Sprague-Dawley rats received a normal chow diet, HFD, 10% fructose or 0.02% sucralose for 10 weeks. Behavioral changes were assessed by open field (OFT) and elevated plus-maze (EPM) tests at week 8. H&E staining was used to observe pathological changes in adrenal cortex, testis and perirenal adipose tissue. Serum hormone concentrations were quantified via enzyme-linked immunosorbent assay (ELISA). The mRNA expression levels of genes along the HPA and HPG axes were determined using real-time PCR.

RESULTS

All types of dietary interventions increased body weight and disturbed metabolic homeostasis, with anxiogenic phenotype in behavioral tests and damage to cell morphology of adrenal cortex and testis being observed. Along the HPA axis, significantly increased corticotropin releasing hormone (CRH), adrenocorticotropic hormone (ACTH) and corticosterone (CORT) concentrations were observed in the HFD or 0.02% sucralose group. For HPG axis, gonadotropin-releasing hormone (GnRH) and estradiol (E2) concentrations were significantly increased in all dietary intervention groups, while decreased concentrations of follicle-stimulating hormone (FSH) and testosterone (T) were also detected. Moreover, transcriptional profiles of genes involved in the synthesis of hormones and corresponding hormone receptors were significantly altered.

CONCLUSION

Long-term consumption of HFD, fructose or sucralose manifested deleterious effects on endocrine system and resulted in the dysregulation of HPA and HPG axes.

Parabens effects on female reproductive health - Review of evidence from epidemiological and rodent-based studies

Parabens have been used as antimicrobial preservatives since the 1920s. The prevalent use of parabens increases their detection in the environment and in women's biological samples including reproductive tissues. Recent studies suggest parabens may alter endocrine function and thus female reproductive health may be affected. In this literature review, we summarize findings on parabens and female reproduction while focusing on epidemiological and rodent-based studies. The topics reviewed include paraben effects on cyclicity, pregnancy, newborn and pubertal development, reproductive hormones, and ovarian and uterine specific outcomes. Overall, the scientific literature on paraben effects on female reproduction is limited and with some conflicting results. Yet, some epidemiological and/or rodent-based experimental studies report significant findings in relation to paraben effects on cyclicity, fertility, gestation length, birth weight, postnatal development and pubertal onset, hormone levels, and hormone signaling in reproductive tissues. Future epidemiological and experimental studies are needed to better understand paraben effects on female reproduction while focusing on human related exposures including mixtures, physiologic concentrations of parabens, and multi-generational studies.

Association of obesity and menarche SNPs and interaction with environmental factors on precocious puberty

BACKGROUND

Obesity is an important cause for the precocious or early puberty. However, the association between obesity-related loci and the risk of precocious puberty as well as the effect of gene-environment interaction are unclear, especially in the Chinese children population.

METHODS

This was a case-control study using baseline data from two cohorts and hospital cases in China. 15 SNPs loci and several environmental factors were included in the analysis of 1201 participants. Chi-square test and logistic regression were used to analyze the association between SNPs and precocious puberty. Additionally, exploratory factor analysis was conducted on 13 environmental variables, and then to explore their interaction with genes on precocious puberty.

RESULTS

The effect allele C of rs571312, and G of rs12970134 MC4R were associated with precocious puberty in girls with obesity. Regarding the gene-environment interaction, we found that when girls were in the high socioeconomic status, the rs571312 (OR: 3.996; 95% CI: 1.694-9.423) and rs12970134 (OR: 3.529; 95% CI: 1.452-8.573) risk genotypes had a greater effect on precocious puberty.

CONCLUSIONS

The obesity risk gene polymorphisms MC4R rs571312 and rs12970134 were associated with precocious puberty in Chinese girls with obesity, and girls with risk genotypes and high socioeconomic status should be given extra attention.

IMPACT

This is the first study that identified the association between rs571312 and rs12970134 of MC4R gene and precocious puberty in Chinese children. We found that when girls were in the high socioeconomic status, the risk genotypes of rs571312 and rs12970134 had a greater effect on precocious puberty. The results of this study have great public health implications. It is recommended that girls who are in high socioeconomic status and have a high genetic risk for early sexual maturity should closely monitor their pubertal development and consider early intervention strategies.

Identification of Environmental Compounds That May Trigger Early Female Puberty by Activating Human GnRHR and KISS1R

There has been an alarming trend toward earlier puberty in girls, suggesting the influence of an environmental factor(s). As the reactivation of the reproductive axis during puberty is thought to be mediated by the hypothalamic neuropeptides kisspeptin and gonadotropin-releasing hormone (GnRH), we asked whether an environmental compound might activate the kisspeptin (KISS1R) or GnRH receptor (GnRHR). We used GnRHR or KISS1R-expressing HEK293 cells to screen the Tox21 10K compound library, a compendium of pharmaceuticals and environmental compounds, for GnRHR and KISS1R activation. Agonists were identified using Ca2+ flux and phosphorylated extracellularly regulated kinase (p-ERK) detection assays. Follow-up studies included measurement of genes known to be upregulated upon receptor activation using relevant murine or human cell lines and molecular docking simulation. Musk ambrette was identified as a KISS1R agonist, and treatment with musk ambrette led to increased expression of Gnrh1 in murine and human hypothalamic cells and expansion of GnRH neuronal area in developing zebrafish larvae. Molecular docking demonstrated that musk ambrette interacts with the His309, Gln122, and Gln123 residues of the KISS1R. A group of cholinergic agonists with structures similar to methacholine was identified as GnRHR agonists. When applied to murine gonadotrope cells, these agonists upregulated Fos, Jun, and/or Egr1. Molecular docking revealed a potential interaction between GnRHR and 5 agonists, with Asn305 constituting the most conservative GnRHR binding site. In summary, using a Tox21 10K compound library screen combined with cellular, molecular, and structural biology techniques, we have identified novel environmental agents that may activate the human KISS1R or GnRHR.

Evaluating Phthalates and Bisphenol in Foods: Risks for Precocious Puberty and Early-Onset Obesity

Recent scientific results indicate that diet is the primary source of exposure to endocrine-disrupting chemicals (EDCs) due to their use in food processing, pesticides, fertilizers, and migration from packaging to food, particularly in plastic or canned foods. Although EDCs are not listed on nutrition labels, their migration from packaging to food could inadvertently lead to food contamination, affecting individuals by inhalation, ingestion, and direct contact. The aim of our narrative review is to investigate the role of phthalates and bisphenol A (BPA) in foods, assessing their risks for precocious puberty (PP) and early-onset obesity, which are two clinical entities that are often associated and that share common pathogenetic mechanisms. The diverse outcomes observed across different studies highlight the complexity of phthalates and BPA effects on the human body, both in terms of early puberty, particularly in girls, and obesity with its metabolic disruptions. Moreover, obesity, which is independently linked to early puberty, might confound the relationship between exposure to these EDCs and pubertal timing. Given the potential public health implications, it is crucial to adopt a precautionary approach, minimizing exposure to these EDCs, especially in vulnerable populations such as children.

Evaluation and comparison of nine growth and development-based measures of pubertal timing

BACKGROUND

Pubertal timing is heritable, varies between individuals, and has implications for life-course health. There are many different indicators of pubertal timing, and how they relate to each other is unclear. Our aim was to quantitatively compare nine indicators of pubertal timing.

METHODS

We used data from questionnaires and height, weight, and bone measurements from ages 7-17 y in a population-based cohort of 4267 females and 4251 males to compare nine growth and development-based indicators of pubertal timing. We summarise age of each indicator, their phenotypic and genetic correlations, and how they relate to established genetic risk score (GRS) for puberty timing, and phenotypic childhood body composition measures.

RESULTS

We show that pubic hair in males (mean: 12.6 y) and breasts in females (11.5 y) are early indicators of puberty, and voice breaking (14.2 y) and menarche (12.7 y) are late indicators however, there is substantial variation between individuals in pubertal age. All indicators show evidence of positive phenotypic intercorrelations (e.g., r = 0.49: male genitalia and pubic hair ages), and positive genetic intercorrelations. An age at menarche GRS positively associates with all other pubertal age indicators (e.g., difference in female age at peak height velocity per SD higher GRS: 0.24 y, 95%CI: 0.21 to 0.26), as does an age at voice breaking GRS (e.g., difference in age at male axillary hair: 0.11 y, 0.07 to 0.15). Higher childhood fat mass and lean mass associated with earlier puberty timing.

CONCLUSIONS

Our findings provide insights into the measurements of the timing of pubertal growth and development and illustrate value of various pubertal timing indicators in life-course research.

Novel variants ensued genomic imprinting in familial central precocious puberty

INTRODUCTION

Central precocious puberty (CPP) is characterized by the early onset of puberty and is associated with the critical processes involved in the pubertal switch. The puberty-related gene pool in the human genome is considerably large though few have been described in CPP. Within those genes, the genomic imprinting features of the MKRN3 and DLK1 genes add additional complexity to the understanding of the pathologic pathways. This study aimed to investigate the molecular etiology in the CPP cohort.

METHODS

Eighteen familial CPP cases were investigated by Sanger sequencing for five CPP-related genes; DLK1, KISS1, KISS1R, MKRN3, and PROKR2. Segregation analysis was performed in all patients with pathogenic variants. Using an ELISA test, the functional pathogenicity of novel variants was also investigated in conjunction with serum delta-like 1 homolog (DLK1) concentrations.

RESULTS

In three probands, a known variant in the MKRN3 gene (c.982C>T/p.(Arg328Cys)) and two novel variants in the DLK1 gene (c.357C>G/p.(Tyr119Ter) and c.67+78C>T) were identified. All three were inherited from the paternal allele. The individuals carrying the DLK1 variants had low detectable DLK1 levels in their serum.

CONCLUSIONS

The frequencies were 5.5% (1/18) for MKRN3 11% (2/18) for DLK1, and none for either KISS1, KISS1R, and PROKR2. Low serum DLK1 levels in affected individuals supported the relationship between here described novel DLK1 gene variants with CPP. Nonsense nature of c.357C>G/p.(Tyr119Ter) and an alteration in the evolutionarily conserved nucleotide c.67+78C>T suggested the disruptive nature of the variant's compatibility with CPP.

Adolescent gut microbiome imbalance and its association with immune response in inflammatory bowel diseases and obesity

BACKGROUND

Recently, there has been an increase in the number of studies focusing on the association between the gut microbiome and obesity or inflammatory diseases, especially in adults. However, there is a lack of studies investigating the association between gut microbiome and gastrointestinal (GI) diseases in adolescents.

METHOD

We obtained 16S rRNA-seq datasets for gut microbiome analysis from 202 adolescents, comprising ulcerative colitis (UC), Crohn's disease (CD), obesity (Ob), and healthy controls (HC). We utilized Quantitative Insights Into Microbial Ecology (QIIME) and Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) to acquire Operational Taxonomic Units (OTUs). Subsequently, we analyzed Kyoto Encyclopedia of Genes and Genomes (KEGG) Orthology (KO) terms and pathway enrichment for the identified OTUs.

RESULTS

In this study, we investigated the difference between the gut microbiomes in adolescents with GI diseases and those in healthy adolescents using 202 samples of 16S rRNA sequencing data. The distribution of the six main gut microbiota (i.e., unclassified Dorea, unclassified Lachnospiraceae, unclassified Ruminococcus, Faecalibacterium prausnitzii, Prevotella copri, unclassified Sutterella) was different based on the status of obesity and inflammatory diseases. Dysbiosis was observed within Lachnospiraceae in adolescents with inflammatory diseases (i.e., UC and CD), and in adolescents with obesity within Prevotella and Sutterella. More specifically, our results showed that the relative abundance of Faecalibacterium prausnitzii and unclassified Lachnospiraceae was more than 10% and 8% higher, respectively, in the UC group compared to the CD, Ob, and HC groups. Additionally, the Ob group had over 20% and over 3% higher levels of Prevotella copri and unclassified Sutterella, respectively, compared to the UC, CD, and HC groups. Also, inspecting associations between the six specific microbiota and KO terms, we found that the six microbiota -relating KO terms were associated with NOD-like receptor signaling. These six taxa differences may affect the immune system and inflammatory response by affecting NOD-like receptor signaling in the host during critical adolescence.

CONCLUSION

In this study, we discovered that dysbiosis of the microbial community had varying degrees of influence on the inflammatory and immune response pathways in adolescents with inflammatory diseases and obesity.

Mini-Puberty, Physiological and Disordered: Consequences, and Potential for Therapeutic Replacement

There are 3 physiological waves of central hypothalamic-pituitary-gonadal (HPG) axis activity over the lifetime. The first occurs during fetal life, the second-termed "mini-puberty"-in the first months after birth, and the third at puberty. After adolescence, the axis remains active all through adulthood. Congenital hypogonadotropic hypogonadism (CHH) is a rare genetic disorder characterized by a deficiency in hypothalamic gonadotropin-releasing hormone (GnRH) secretion or action. In cases of severe CHH, all 3 waves of GnRH pulsatility are absent. The absence of fetal HPG axis activation manifests in around 50% of male newborns with micropenis and/or undescended testes (cryptorchidism). In these boys, the lack of the mini-puberty phase accentuates testicular immaturity. This is characterized by a low number of Sertoli cells, which are important for future reproductive capacity. Thus, absent mini-puberty will have detrimental effects on later fertility in these males. The diagnosis of CHH is often missed in infants, and even if recognized, there is no consensus on optimal therapeutic management. Here we review physiological mini-puberty and consequences of central HPG axis disorders; provide a diagnostic approach to allow for early identification of these conditions; and review current treatment options for replacement of mini-puberty in male infants with CHH. There is evidence from small case series that replacement with gonadotropins to mimic "mini-puberty" in males could have beneficial outcomes not only regarding testis descent, but also normalization of testis and penile sizes. Moreover, such therapeutic replacement regimens in disordered mini-puberty could address both reproductive and nonreproductive implications.

Long-term exposure to air pollution and precocious puberty in South Korea

BACKGROUND AND AIM

The increasing prevalence of precocious puberty (PP) has emerged as a significant medical and social problem worldwide. However, research on the relationship between long-term air pollution exposure and PP has been relatively limited. We thus investigated the association between long-term air pollution exposure and the onset of PP in South Korea.

METHODS

We investigated a retrospective cohort using the Korea National Health Insurance Database. Six-year-old children born from 2007 to 2009 were examined (2013-2015). We included boys ≤10 years and girls aged ≤9 years who visited hospitals for early pubertal development, were diagnosed with PP per the ICD-10 (E228, E301, and E309), and received gonadotropin-releasing hormone agonist treatment. We analyzed data for boys up until 10 years old (60-month follow-up) and for girls up to 9 years old (48-month follow-up). We assessed the association between long-term air pollution exposure and the onset of PP using a Cox proportional hazard model. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) per 1 μg/m3 increase in fine particulate matter (PM2.5) and particulate matter (PM10) and per 1 ppb increase in sulfur dioxide (SO2), nitrogen dioxide (NO2), and ozone (O3).

RESULTS

This study included 1,205,784 children aged six years old between 2013 and 2015. A positive association was found between the 48-month moving average PM2.5 (HR: 1.019; 95% CI: 1.012, 1.027), PM10 (HR: 1.009; 95% CI: 1.006, 1.013), SO2 (HR: 1.037; 95% CI: 1.018, 1.055), and O3 (HR: 1.006; 95% CI: 1.001, 1.010) exposure and PP in girls but not boys.

CONCLUSIONS

This study provides valuable insights into the harmful effects of air pollution during childhood and adolescence, emphasizing that air pollution is a risk factor that should be managed and reduced.

Nasal application of kisspeptin-54 mitigates motor deficits by reducing nigrostriatal dopamine loss in hemiparkinsonian rats

Parkinson's Disease is a progressive neurodegenerative disorder characterized by motor symptoms resulting from the loss of nigrostriatal dopaminergic neurons. Kisspeptins (KPs) are a family of neuropeptides that are encoded by the Kiss-1 gene, which exert their physiological effects through interaction with the GPR54 receptor. In the current investigation, we investigated the prospective protective effects of central KP-54 treatments on nigrostriatal dopaminergic neurons and consequent motor performance correlates in 6-hydroxydopamine (6-OHDA)-lesioned rats. Male adult Sprague Dawley rats underwent stereotaxic injection of 6-OHDA into the right medial forebrain bundle to induce hemiparkinsonism. Following surgery, rats received chronic central treatments of nasal or intracerebroventricular KP-54 (logarithmically increasing doses) for seven consecutive days. Motor performance was evaluated seven days post-surgery utilizing the open field test and catalepsy test. The levels of dopamine in the striatum were determined with mass spectrometry. Immunohistochemical analysis was conducted to assess the immunoreactivities of tyrosine hydroxylase (TH) and the GPR54 in the substantia nigra. The dose-response curve revealed a median effective dose value of ≈3 nmol/kg for both central injections. Due to its non-invasive and effective nature, nasal administration was utilized in the second phase of our study. Chronic administration of KP-54 (3nmol/kg, nasally) significantly protected 6-OHDA-induced motor deficits. Nasal KP-54 attenuated the loss of nigrostriatal dopaminergic neurons induced by 6-OHDA. Additionally, significant correlations were observed between motor performance and nigrostriatal dopamine levels. Immunohistochemical analysis demonstrated the localization of the GPR54 within TH-positive nigral cells. These findings suggest the potential efficacy of central KP-54 on motor impairments in hemiparkinsonism.

Methylome analysis in girls with idiopathic central precocious puberty

BACKGROUND

Genetic and environmental factors are implicated in many developmental processes. Recent evidence, however, has suggested that epigenetic changes may also influence the onset of puberty or the susceptibility to a wide range of diseases later in life. The present study aims to investigate changes in genomic DNA methylation profiles associated with pubertal onset analyzing human peripheral blood leukocytes from three different groups of subjects: 19 girls with central precocious puberty (CPP), 14 healthy prepubertal girls matched by age and 13 healthy pubertal girls matched by pubertal stage. For this purpose, the comparisons were performed between pre- and pubertal controls to identify changes in normal pubertal transition and CPP versus pre- and pubertal controls.

RESULTS

Analysis of methylation changes associated with normal pubertal transition identified 1006 differentially methylated CpG sites, 86% of them were found to be hypermethylated in prepubertal controls. Some of these CpG sites reside in genes associated with the age of menarche or transcription factors involved in the process of pubertal development. Analysis of methylome profiles in CPP patients showed 65% and 55% hypomethylated CpG sites compared with prepubertal and pubertal controls, respectively. In addition, interestingly, our results revealed the presence of 43 differentially methylated genes coding for zinc finger (ZNF) proteins. Gene ontology and IPA analysis performed in the three groups studied revealed significant enrichment of them in some pathways related to neuronal communication (semaphorin and gustation pathways), estrogens action, some cancers (particularly breast and ovarian) or metabolism (particularly sirtuin).

CONCLUSIONS

The different methylation profiles of girls with normal and precocious puberty indicate that regulation of the pubertal process in humans is associated with specific epigenetic changes. Differentially methylated genes include ZNF genes that may play a role in developmental control. In addition, our data highlight changes in the methylation status of genes involved in signaling pathways that determine the migration and function of GnRH neurons and the onset of metabolic and neoplastic diseases that may be associated with CPP in later life.

The Association between Autism Spectrum Disorder and Precocious Puberty: Considering Effect Modification by Sex and Neuropsychiatric Comorbidities

Limited knowledge is available about the association between autistic spectrum disorder (ASD) and precocious puberty. Our study examined the association between the two medical conditions and effect modification by sex and neuropsychiatric comorbidities in a nationwide population. To compare the risk of precocious puberty between ASD and non-ASD cases, we conducted a Cox regression analysis using ASD as the exposure and time to precocious puberty as the outcome. We adjusted for sex, attention-deficit/hyperactivity disorder (ADHD), tic disorder, obsessive-compulsive disorder (OCD), anxiety disorder, intellectual disability, and epilepsy. We performed a moderation analysis to examine the potential moderating effects of sex and comorbidities. Patients with ASD were prone to have precocious puberty, with an adjusted hazard ratio (aHR) of 1.80 (95% CI: 1.61-2.01). For effect modification, sex, specifically females, moderated the association between ASD and precocious puberty, with a relative excess risk due to interaction (RERI) of 7.35 (95% CI 4.90-9.80). No significant effect modification was found for any of the comorbidities within the scope of additive effect modification. We found that patients with ASD were prone to precocious puberty, regardless of sex or comorbid neuropsychiatric disorders. Girls with ASD are at a particularly higher risk of developing precocious puberty.

Temporal trend of age at menarche in Korean females born between 1927 and 2004: a population-based study

Backgrounds

The age at menarche has decreased worldwide. Previous studies on Korean adolescents have reported a downward trend in age at menarche. This study aimed to investigate the current trends in age at menarche among Korean adolescents using nationally representative data.

Materials and methods

The study used data from the Korea National Health and Nutrition Examination Survey 2007-2021. A total of 50,730 females born between 1927 and 2004 with information on age at menarche were included. The trend in age at menarche was analyzed according to 15 birth-year groups (with 5-year intervals) using quantile regression analysis.

Results

The mean age at menarche decreased from 16.92 ± 0.06 years for females born before 1935 to 12.45 ± 0.04 years for females born between 2000 and 2004 (p <.001). According to the percentile group of age at menarche, mean menarche age decreased by -0.071 years per year (95% confidence interval [CI], -0.072 to -0.070) in total, -0.050 years per year (95% CI, -0.052 to -0.048) in the 3rd percentile group, -0.088 years per year (95% CI, -0.091 to -0.085) in the 97th percentile group (p <.001 for all). A decreasing trend of age at menarche was more prominent in the obesity group (-0.080 years per year, 95% CI, -0.082 to -0.078) compared to the non-obesity group (-0.069 years per year, 95% CI, -0.071 to -0.068) (p <.001 for both).

Conclusion

Ongoing downward trend in age at menarche was observed in Korean females born until 2004, decreasing by 0.71 years per decade. The downward trend was faster in individuals with a higher percentile of age at menarche and in those with obesity.

Menarche-a journey into womanhood: age at menarche and health-related outcomes in East Asians

STUDY QUESTION

Are there associations of age at menarche (AAM) with health-related outcomes in East Asians?

SUMMARY ANSWER

AAM is associated with osteoporosis, Type 2 diabetes (T2D), glaucoma, and uterine fibroids, as demonstrated through observational studies, polygenic risk scores, genetic correlations, and Mendelian randomization (MR), with additional findings indicating a causal effect of BMI and T2D on earlier AAM.

WHAT IS KNOWN ALREADY

Puberty timing is linked to adult disease risk, but research predominantly focuses on European populations, with limited studies in other groups.

STUDY DESIGN, SIZE, DURATION

We performed an AAM genome-wide association study (GWAS) with 57 890 Han Taiwanese females and examined the association between AAM and 154 disease outcomes using the Taiwanese database. Additionally, we examined genetic correlations between AAM and 113 diseases and 67 phenotypes using Japanese GWAS summary statistics.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We performed AAM GWAS and gene-based GWAS studies to obtain summary statistics and identify potential AAM-related genes. We applied phenotype, polygenic risk scores, and genetic correlation analyses of AAM to explore health-related outcomes, using multivariate regression and linkage disequilibrium score regression analyses. We also explored potential bidirectional causal relationships between AAM and related outcomes through univariable and multivariable MR analyses.

MAIN RESULTS AND THE ROLE OF CHANCE

Fifteen lead single-nucleotide polymorphisms and 24 distinct genes were associated with AAM in Taiwan. AAM was genetically associated with later menarche and menopause, greater height, increased osteoporosis risk, but lower BMI, and reduced risks of T2D, glaucoma, and uterine fibroids in East Asians. Bidirectional MR analyses indicated that higher BMI/T2D causally leads to earlier AAM.

LIMITATIONS, REASONS FOR CAUTION

Our findings were specific to Han Taiwanese individuals, with genetic correlation analyses conducted in East Asians. Further research in other ethnic groups is necessary.

WIDER IMPLICATIONS OF THE FINDINGS

Our study provides insights into the genetic architecture of AAM and its health-related outcomes in East Asians, highlighting causal links between BMI/T2D and earlier AAM, which may suggest potential prevention strategies for early puberty.

STUDY FUNDING/COMPETING INTEREST(S)

The work was supported by China Medical University, Taiwan (CMU110-S-17, CMU110-S-24, CMU110-MF-49, CMU111-SR-158, CMU111-MF-105, CMU111-MF-21, CMU111-S-35, CMU112-SR-30, and CMU112-MF-101), the China Medical University Hospital, Taiwan (DMR-111-062, DMR-111-153, DMR-112-042, DMR-113-038, and DMR-113-103), and the Ministry of Science and Technology, Taiwan (MOST 111-2314-B-039-063-MY3, MOST 111-2314-B-039-064-MY3, MOST 111-2410-H-039-002-MY3, and NSTC 112-2813-C-039-036-B). The funders had no influence on the data collection, analyses, or conclusions of the study. No conflict of interests to declare.

TRIAL REGISTRATION NUMBER

N/A.

Normal Puberty

Puberty is characterized by gonadarche and adrenarche. Gonadarche represents the reactivation of the hypothalamic-pituitary-gonadal axis with increased gonadotropin-releasing hormone, luteinizing hormone, and follicle-stimulating hormone secretion following the quiescence during childhood. Pubarche is the development of pubic hair, axillary hair, apocrine odor reflecting the onset of pubertal adrenal maturation known as adrenarche. A detailed understanding of these pubertal processes will help clarify relationships between the timing of the onset of puberty and cardiovascular, metabolic, and reproductive outcomes in adulthood. The onset of gonadarche is influenced by neuroendocrine signals, genetic variants, metabolic factors, and environmental elements.

MRI Radiomics Features of Adenohypophysis Determine the Activation of Hypothalamic-Pituitary-Gonadal Axis in Peri-Puberty Children

BACKGROUND

The status of the hypothalamic-pituitary-gonadal (HPG) axis is important for assessing the onset of physiological or pathological puberty. The reference standard gonadotropin-releasing hormone (GnRH) stimulation test requires hospital admission and repeated blood samples. A simple noninvasive method would be beneficial.

OBJECTIVES

To explore a noninvasive method for evaluating HPG axis activation in children using an MRI radiomics model.

STUDY TYPE

Retrospective.

POPULATION

Two hundred thirty-nine children (83 male; 3.6-14.6 years) with hypophysial MRI and GnRH stimulation tests, randomly divided a training set (168 children) and a test set (71 children).

FIELD STRENGTH/SEQUENCE

3.0 T, 3D isotropic fast spin echo (CUBE) T1-weighted imaging (T1WI) sequences.

ASSESSMENT

Radiomics features were extracted from sagittal 3D CUBE T1WI, and imaging signatures were generated using the least absolute shrinkage and selection operator (LASSO) with 10-fold cross-validation. Diagnostic performance for differential diagnosis of HPG status was compared between a radiomics model and MRI features (adenohypophyseal height [aPH] and volume [aPV]).

STATISTICAL TESTS

Receiver operating characteristic (ROC) and decision curve analysis (DCA). A P value <0.05 was considered statistically significant.

RESULTS

Eight hundred fifty-one radiomics features were extracted and reduced to 10 by the LASSO method in the training cohort. The radiomics model based on CUBE T1WI showed good performance in assessment of HPG axis activation with an area under the ROC curve (AUC) of 0.81 (95% CI: 0.71, 0.91) in the test set. The AUC of the radiomics model was significantly higher than that of aPH (0.81 vs. 0.65) but there was no significant difference compared to aPV (0.81 vs. 0.78, P = 0.58). In DCA analysis, the radiomics signature showed higher net benefit over the aPV and aPH models.

DATA CONCLUSIONS

The MRI radiomics model has potential to assess HPG axis activation status noninvasively, potentially providing valuable information in the diagnosis of patients with pathological puberty onset.

EVIDENCE LEVEL

4 TECHNICAL EFFICACY: Stage 2.

Irisin combined index to diagnose central precocious puberty in girls: a cross-sectional study

BACKGROUND

To investigate serum irisin levels in girls at different developmental status and explore the significance of irisin for the diagnosis of central precocious puberty (CPP) in girls.

METHODS

In this cross-sectional study 111 girls were enrolled, including 43 cases of CPP, 44 cases of peripheral precocious puberty (PPP) and 24 cases of girls with normal sexual development as controls. The data on age, weight and height, measured blood levels of luteinizing hormone (LH), follicle stimulating hormone (FSH), estradiol, and irisin were collected. Pelvic Doppler ultrasound was performed to evaluate uterine length, transverse diameter, anteroposterior diameter. The girls were divided into non-CPP group and CPP group according to gonadotropin-releasing hormone (GnRH) stimulation test.

RESULTS

Serum irisin levels were significantly higher in CPP group than in PPP group and normal control group. Serum irisin level was positively correlated with basal LH level, basal FSH level, peak LH level, peak LH /FSH ratio, uterine volume, bone age, and bone age index. The area under the curve, cut-off value, sensitivity and specificity of serum irisin were 0.958, 219.255 pg/ml, 100% and 80.6%. The combined diagnosis of CPP in girls by serum irisin and serum basal LH combined with uterine volume had an AUC, sensitivity, and specificity of 0.994, 97.6%, and 100%, superior to that of the single index.

CONCLUSIONS

Serum irisin level in girls with CPP is significantly increased. An irisin combined index could help the diagnosis of CPP in girls.

Complete Blood Count-Derived Inflammation Indexes Are Useful in Predicting Metabolic Syndrome in Children and Adolescents with Severe Obesity

Background: Childhood obesity is a globally increasing pathological condition leading to long-term health issues such as cardiovascular diseases and metabolic syndrome (MetS). This study aimed to determine the clinical value of the Complete Blood Count-derived inflammation indexes Monocyte/HDL-C ratio (MHR), Lymphocyte/HDL-C ratio (LHR), Neutrophil/HDL-C ratio (NHR), and System Inflammation Response Index (SIRI) to predict the presence of metabolic syndrome and its association with cardiovascular risk markers (HOMA-IR, TG/HDL-C, and non-HDL-C) in children and adolescents with obesity. Methods: The study included a total of 552 children/adolescents with severe obesity (BMI: 36.4 [32.7-40.7] kg/m2; 219 males, 333 females; age: 14.8 [12.9-16.3] years), who were further subdivided based on the presence or absence of metabolic syndrome (MetS+ and MetS respectively). Results: The MHR, LHR, and NHR indexes (p < 0.0001), but not SIRI (p = 0.524), were significantly higher in the MetS+ compared to the MetS- subgroup, showing a positive correlation with the degree of MetS severity (p < 0.0001). Furthermore, MHR, LHR, and NHR were positively associated with cardiometabolic risk biomarkers (HOMA-IR: MHR p = 0.000, LHR p = 0.001, NHR p < 0.0001; TG/HDL-C: MHR, LHR, NHR p < 0.000; non-HDL-C: MHR, LHR p < 0.0001, NHR p = 0.000). Finally, the ROC curve analysis demonstrated that among the analyzed indexes, only MHR, LHR, and NHR had diagnostic value in distinguishing MetS patients among children and adolescents with obesity (MHR: AUC = 0.7045; LHR: AUC = 0.7205; NHR: AUC = 0.6934; p < 0.0001). Conclusions: In conclusion, the MHR, LHR, and NHR indexes, but not the SIRI index, can be considered useful tools for pediatricians to assess the risk of MetS and cardiometabolic diseases in children and adolescents with obesity and to develop multidisciplinary intervention strategies to counteract the widespread disease.

The functional study of a novel MKRN3 missense mutation associated with familial central precocious puberty

Central precocious puberty (CPP) refers to a syndrome of early puberty initiation with a characteristic increase in the release of gonadotropin-releasing hormone (GnRH); therefore, it is also called GnRH-related precocious puberty. About a quarter of idiopathic central precocious puberty (ICPP) may be familial. Studies suggest that mutations of makorin ring finger protein 3 (MKRN3) can cause familial central precocious puberty (FCPP). In this report, we describe a Chinese female patient carrying a novel MKRN3 variant (c.980G>A/p.Arg327His) and presenting the CPP phenotype. This novel variant attenuated its own ubiquitination, degradation, and inhibition on the transcriptional and translational activity of GNRH1, which was verified through functional tests. We can consider this variant as a loss-of-function mutation, which subsides the inhibition of GnRH1-related signaling and gives rise to GnRH-related precocious puberty.

Socio-demographic inequalities influence differences in the chemical exposome among Swedish adolescents

Relatively little is known about the relationship between socio-demographic factors and the chemical exposome in adolescent populations. This knowledge gap hampers global efforts to meet certain UN sustainability goals. The present work addresses this problem in Swedish adolescents by discerning patterns within the chemical exposome and identify demographic groups susceptible to heightened exposures. Enlisting the Riksmaten Adolescents 2016-17 (RMA) study population (N = 1082) in human-biomonitoring, and using proportional odds ordinal logistic regression models, we examined the associations between concentrations of a diverse array of substances (N = 63) with the determinants: gender, age, participant/maternal birth country income per capita level, parental education levels, and geographic place of living (longitude/latitude). Participant/maternal birth country exhibited a significant association with the concentrations of 46 substances, followed by gender (N = 41), and longitude (N = 37). Notably, individuals born in high-income countries by high-income country mothers demonstrated substantially higher estimated adjusted means (EAM) concentrations of polychlorinated biphenyls (PCBs), brominated flame retardants (BFRs) and per- and polyfluoroalkyl substances (PFASs) compared to those born in low-income countries by low-income country mothers. A reverse trend was observed for cobalt (Co), cadmium (Cd), lead (Pb), aluminium (Al), chlorinated pesticides, and phthalate metabolites. Males exhibited higher EAM concentrations of chromium (Cr), mercury (Hg), Pb, PCBs, chlorinated pesticides, BFRs and PFASs than females. In contrast, females displayed higher EAM concentrations of Mn, Co, Cd and metabolites of phthalates and phosphorous flame retardants, and phenolic substances. Geographical disparities, indicative of north-to-south or west-to-east substance concentrations gradients, were identified in Sweden. Only a limited number of lifestyle, physiological and dietary factors were identified as possible drivers of demographic inequalities for specific substances. This research underscores birth country, gender, and geographical disparities as contributors to exposure differences among Swedish adolescents. Identifying underlying drivers is crucial to addressing societal inequalities associated with chemical exposure and aligning with UN sustainability goals.

Effects of pharmaceutical and personal care products on pubertal development: Evidence from human and animal studies

Pharmaceutical and personal care products (PPCPs) include a wide range of drugs, personal care products and household chemicals that are produced and used in significant quantities. The safety of PPCPs has become a growing concern in recent decades due to their ubiquitous presence in the environment and potential risks to human health. PPCPs have been detected in various human biological samples, including those from children and adolescents, at concentrations ranging from several ng/L to several thousand μg/L. Epidemiological studies have shown associations between exposure to PPCPs and changes in the timing of puberty in children and adolescents. Animal studies have shown that exposure to PPCPs results in advanced or delayed pubertal onset. Mechanisms by which PPCPs regulate pubertal development include alteration of the hypothalamic kisspeptin and GnRH networks, disruption of steroid hormones, and modulation of metabolic function and epigenetics. Gaps in knowledge and further research needs include the assessment of environmental exposure to pharmaceuticals in children and adolescents, low-dose and long-term effects of exposure to PPCPs, and the modes of action of PPCPs on pubertal development. In summary, this comprehensive review examines the potential effects of exposure to PPCPs on pubertal development based on evidence from human and animal studies.

The associations of depressive symptoms and perceived stress with arterial health in adolescents

Cardiovascular and mental diseases are among the most important global health problems, but little is known on the associations between mental and arterial health in adolescents. Therefore, we investigated the associations of arterial health with depressive symptoms and perceived stress in adolescents. A total of 277 adolescents, 151 boys, 126 girls, aged 15-17 years participated in the study. Depressive symptoms were assessed using the Beck Depression Inventory and perceived stress by the Cohen Perceived Stress Scale. Arterial health was assessed by measures from carotid ultrasonography (carotid intima-media thickness, Young's Elastic Modulus, carotid artery distensibility, stiffness index), impedance cardiography (pulse wave velocity, cardio-ankle vascular index), and pulse contour analysis (reflection index, stiffness index). The data were analyzed using linear regression models adjusted for age and sex. Depressive symptoms or perceived stress were not associated with indices of arterial health in the whole study group (β = -0.08 to 0.09, p > 0.05), in boys (β = -0.13 to 0.10, p > 0.05) or in girls (standardized regression coefficient β = -0.16 to 0.08, p > 0.05). We found no associations of depressive symptoms and perceived stress with arterial health in adolescents. These observations suggest that the association between mental and arterial health problems develop in later life.

Temporal relation between pubertal development and peer victimization in a prospective sample of US adolescents

Peer victimization typically peaks in early adolescence, leading researchers to hypothesize that pubertal timing is a meaningful predictor of peer victimization. However, previous methodological approaches have limited our ability to parse out which puberty cues are associated with peer victimization because gonadal and adrenal puberty, two independent processes, have either been conflated or adrenal puberty timing has been ignored. In addition, previous research has overlooked the possibility of reverse causality-that peer victimization might drive pubertal timing, as it has been shown to do in non-human primates. To fill these gaps, we followed 265 adolescents (47% female) prospectively across three-time points (Mage : T1 = 9.6, T2 = 12.0, T3 = 14.4) and measured self-report peer victimization and self- and maternal-report of gonadal and adrenal pubertal development on the Pubertal Development Scale. Multilevel modeling revealed that females who were further along in adrenal puberty at age 9 were more likely to report peer victimization at age 12 (Cohen's d = 0.25, p = .005). The relation between gonadal puberty status and peer victimization was not significant for either sex. In terms of the reverse direction, the relation between early peer victimization and later pubertal development was not significant in either sex. Overall, our findings suggest that adrenal puberty status, but not gonadal puberty status, predicted peer victimization in females, highlighting the need to separate gonadal and adrenal pubertal processes in future studies.

Evaluation of the differences in the localization of the lingula mandibulae according to pubertal development in children: A new anthropological and forensic approach

OBJECTIVE

This study aims to investigate changes in lingula mandibulae localization before and after puberty and sex differences.

DESIGN

288 panoramic radiographs evaluated retrospectively were divided into four groups according to pubertal development: under and over 10 years old for females and under and over 11 years old for males. Four anatomic sites were used as reference points: (a) the anterior border of the ramus; (b) the posterior border of the ramus; (c) the deepest point of mandibular notch; and (d) the angulus mandibulae. The ratio of the distances from the lingula mandibulae to points (a) and (b) and the ratio of the distances from the lingula mandibulae to points (c) and (d) were determined. Two-way ANOVA was performed to assess differences between subgroups based on sex and puberty, and a Bonferroni post-hoc test was performed for multiple comparisons.

RESULTS

Puberty and sex has a significant interaction effect on the vertical location of the lingula mandibulae. Postpubertal lingula mandibulae is positioned proportionally more anteriorly by prepubertal localization. In addition, the lingula mandibulae is situated more posteriorly in females compared to males. A significant interaction effect of puberty and sex was observed in relation to the vertical positioning of the lingula mandibulae.

CONCLUSIONS

The spatial localization of the lingula mandibulae and its spatial displacement with age can be used both in estimating sex and the onset of puberty. Changes in the localization of lingula mandibulae according to pubertal development and sex can be used in forensic and anthropological contexts.

Early life adversity accelerates hypothalamic drive of pubertal timing in female rats with associated enhanced acoustic startle

Early life adversity in the form of childhood maltreatment in humans or as modeled by maternal separation (MS) in rodents is often associated with an earlier emergence of puberty in females. Earlier pubertal initiation is an example of accelerated biological aging and predicts later risk for anxiety in women, especially in populations exposed to early life trauma. Here we investigated external pubertal markers as well as hypothalamic gene expression of pubertal regulators kisspeptin and gonadotropin-releasing hormone, to determine a biological substrate for MS-induced accelerated puberty. We further investigated a mechanism by which developmental stress might regulate pubertal timing. As kisspeptin and gonadotropin-releasing hormone secretion are typically inhibited by corticotropin releasing hormone at its receptor CRH-R1, we hypothesized that MS induces a downregulation of Crhr1 gene transcription in a cell-specific manner. Finally, we explored the association between pubertal timing and anxiety-like behavior in an acoustic startle paradigm, to drive future preclinical research linking accelerated puberty and anxiety. We replicated previous findings that MS leads to earlier puberty in females but not males, and found expression of kisspeptin and gonadotropin-releasing hormone mRNA to be prematurely increased in MS females. RNAscope confirmed increased expression of these genes, and further revealed that kisspeptin-expressing neurons in females were less likely to express Crhr1 after MS. Early puberty was associated with higher acoustic startle magnitude in females. Taken together, these findings indicate precocial maturation of central pubertal timing mechanisms after MS, as well as a potential role of CRH-R1 in these effects and an association with a translational measure of anxiety.

Illuminating the terminal nerve: Uncovering the link between GnRH-1 neuron and olfactory development

During embryonic development, the olfactory placode (OP) generates migratory neurons, including olfactory pioneer neurons, cells of the terminal nerve (TN), gonadotropin-releasing hormone-1 (GnRH-1) neurons, and other uncharacterized neurons. Pioneer neurons from the OP induce olfactory bulb (OB) morphogenesis. In mice, GnRH-1 neurons appear in the olfactory system around mid-gestation and migrate via the TN axons to different brain regions. The GnRH-1 neurons are crucial in controlling the hypothalamic-pituitary-gonadal axis. Kallmann syndrome is characterized by impaired olfactory system development, defective OBs, secretion of GnRH-1, and infertility. The precise mechanistic link between the olfactory system and GnRH-1 development remains unclear. Studies in humans and mice highlight the importance of the prokineticin-2/prokineticin-receptor-2 (Prokr2) signaling pathway in OB morphogenesis and GnRH-1 neuronal migration. Prokr2 loss-of-function mutations can cause Kallmann syndrome (KS), and hence the Prokr2 signaling pathway represents a unique model to decipher the olfactory/GnRH-1 connection. We discovered that Prokr2 is expressed in the TN neurons during the critical period of GnRH-1 neuron formation, migration, and induction of OB morphogenesis. Single-cell RNA sequencing identified that the TN is formed by neurons distinct from the olfactory neurons. The TN neurons express multiple genes associated with KS. Our study suggests that the aberrant development of pioneer/TN neurons might cause the KS spectrum.

Aspartame Intake Delayed Puberty Onset in Female Offspring Rats and Girls

SCOPE

The disturbance of the hypothalamic-pituitary-gonadal (HPG) axis, gut microbiota (GM) community, and short-chain fatty acids (SCFAs) is a triggering factor for pubertal onset. The study investigates the effects of the long-term intake of aspartame on puberty and GM in animals and humans.

METHODS AND RESULTS

Aspartame-fed female offspring rats result in vaginal opening time prolongation, serum estrogen reduction, and serum luteinizing hormone elevation. , 60 mg kg-1 aspartame treatment decreases the mRNA levels of gonadotropin-releasing hormone (GnRH), Kiss1, and G protein-coupled receptor 54 (GPR54), increases the mRNA level of RFamide-related peptide-3 (RFRP-3), and decreases the expression of GnRH neurons in the hypothalamus. Significant differences in relative bacterial abundance at the genus levels and decreased fecal SCFA levels are noted by 60 mg kg-1 aspartame treatment. Among which, Escherichia-Shigella is negatively correlated with several SCFAs. In girls, high-dose aspartame consumption decreases the risk of precocious puberty.

CONCLUSIONS

Aspartame reduces the chance of puberty occurring earlier than usual in female offspring and girls. Particularly, 60 mg kg-1 aspartame-fed female offspring delays pubertal onset through the dysregulation of HPG axis and GM composition by inhibiting the Kiss1/GPR54 system and inducing the RFRP-3. An acceptable dose of aspartame should be recommended during childhood.

COVID-19 lockdown and the rate of central precocious puberty

PURPOSE

The aim of our study was to compare the incidence of idiopathic central precocious puberty (CPP) in our highly specialized Endocrinological Center before and after the onset of COVID-19 lockdown; we also aimed to identify any potential difference between girls with CPP from the two different time periods.

METHODS

We retrospectively analyzed the auxological profile of 49 girls with idiopathic CPP: 30 with pre-lockdown onset and 19 with post-lockdown onset of the disease. We collected patients' characteristics (medical history, physical examination, baseline and dynamic hormonal assessment, bone age, pelvic ultrasound) and compared them between the two groups.

RESULTS

We registered an almost threefold increase in CPP incidence in the 2020-2021 period compared to the previous six years. In post-lockdown patients we found a trend for an earlier diagnosis in terms of both chronological age (p 0.0866) and days between the onset of first pubertal signs and diagnosis (p 0.0618). We also found that post-lockdown patients had a significantly lower hypothalamus-pituitary-gonadal axis activation (lower ∆LH% after GnRH test, p 0.0497), a significantly lower increase in bone age calculated at RUS with TW3 method (p 0.0438) and a significantly reduced ovarian activation in females (lower delta-4-androstenedione levels, p 0.0115). Interestingly, post-lockdown patients were born from mothers with an older age at menarche (p 0.0039).

CONCLUSIONS

Besides confirming a significant increase in new diagnoses of CPP in the post-lockdown period, our findings among Post-lockdown girls also suggest a less progressive form of CPP and a stronger environmental influence compared to genetic background in determining the timing of pubertal onset.

Personal Care Product Use during Puberty and Incident Breast Cancer among Black, Hispanic/Latina, and White Women in a Prospective US-Wide Cohort

BACKGROUND

Some personal care products (PCPs) contain endocrine-disrupting chemicals that may affect breast cancer (BC) risk. Patterns of use vary by race and ethnicity. Use often starts in adolescence, when rapidly developing breast tissue may be more susceptible to environmental carcinogens. Few studies have examined associations of BC with PCP use during this susceptible window.

OBJECTIVES

We characterized race and ethnicity-specific patterns of PCP use at 10-13 years of age and estimated associations of use with incident BC.

METHODS

At enrollment (2003-2009), Sister Study participants (n = 4,049 Black, 2,104 Latina, and 39,312 White women) 35-74 years of age reported use of 37 "everyday" PCPs during the ages of 10-13 y (did not use, sometimes, or frequently used). We conducted race and ethnicity-specific latent class analyses to separately identify groups of women with similar patterns of beauty, hair, and skincare/hygiene product use. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for associations of identified PCP classes and single products with incident BC using Cox proportional hazards regression.

RESULTS

During a mean follow-up time of 10.8 y, 280 Black, 128 Latina, and 3,137 White women were diagnosed with BC. Classes of adolescent PCP use were not clearly associated with BC diagnosis among Black, Latina, or White women. HRs were elevated but imprecise for frequent nail product and perfume use in Black women (HR = 1.34; 95% CI: 0.85, 2.12) and greater hair product use in Black (HR = 1.28; 95% CI: 0.91, 1.80) and Latina (HR = 1.42; 95% CI: 0.81, 2.48) women compared with lighter use. In single-product models, we observed higher BC incidence associated with frequent use of lipstick, nail products, pomade, perfume, makeup remover, and acne/blemish products in at least one group.

DISCUSSION

This work provides some support for the hypothesis that PCP use during puberty is associated with BC risk. More research is needed to confirm these novel findings. https://doi.org/10.1289/EHP13882.

Effect of zinc intake on association between fluoride exposure and abnormal sex steroid hormones among US pubertal males: NHANES, 2013-2016

Excessive fluoride exposure can disturb the balance of sex hormones. Zinc is essential for sex hormone synthesis and spermatogenesis. But it is not clear how zinc affects the relationship of fluoride exposure with abnormal sex steroid hormones. Here, a total of 1008 pubertal males from the National Health and Nutrition Examination Survey (NHANES) in two cycles (2013-2014, 2015-2016) were enrolled. The concentrations of water fluoride and plasma fluoride and the levels of serum testosterone, estradiol, and sex hormone binding globulin (SHBG) were measured. Two 24-h dietary recall interviews were conducted to assess the dietary zinc intake. The relationships of fluoride exposure and zinc intake with sex hormones were examined using linear regression and logistic regression models, while the generalized additive model was used to evaluate their non-linear relationship. Our findings revealed that for every two-fold increase in plasma fluoride concentration, testosterone levels decreased by 7.27% (95% CI - 11.49%, - 2.86%) and estradiol levels decreased by 8.73% (95% CI - 13.61%, - 3.57%). There was also significant non-linear association observed between zinc intake and SHBG levels. Being in the first tertile of plasma fluoride had a 60% lower risk of high SHBG (OR = 0.40, 95% CI 0.18, 0.89) compared with being in the second tertile. When compared to the first tertile, being in the second tertile of zinc intake was associated with a 63% (OR = 0.37, 95% CI 0.14, 0.98) lower risk of high SHBG. Furthermore, we observed an interactive effect between the plasma fluoride and zinc intake on estradiol and SHBG, as well as the risk of high SHBG (P-interaction < 0.10). These findings suggest that fluoride exposure and zinc intake can affect sex steroid hormone levels and the risk of high SHBG. Notably, zinc intake may alleviate the increased risk of high SHBG and the abnormal changes of estradiol and SHBG caused by higher fluoride exposure.

SEMA6A drives GnRH neuron-dependent puberty onset by tuning median eminence vascular permeability

Innervation of the hypothalamic median eminence by Gonadotropin-Releasing Hormone (GnRH) neurons is vital to ensure puberty onset and successful reproduction. However, the molecular and cellular mechanisms underlying median eminence development and pubertal timing are incompletely understood. Here we show that Semaphorin-6A is strongly expressed by median eminence-resident oligodendrocytes positioned adjacent to GnRH neuron projections and fenestrated capillaries, and that Semaphorin-6A is required for GnRH neuron innervation and puberty onset. In vitro and in vivo experiments reveal an unexpected function for Semaphorin-6A, via its receptor Plexin-A2, in the control of median eminence vascular permeability to maintain neuroendocrine homeostasis. To support the significance of these findings in humans, we identify patients with delayed puberty carrying a novel pathogenic variant of SEMA6A. In all, our data reveal a role for Semaphorin-6A in regulating GnRH neuron patterning by tuning the median eminence vascular barrier and thereby controlling puberty onset.

Development and Validation of a Combined MRI Radiomics, Imaging and Clinical Parameter-Based Machine Learning Model for Identifying Idiopathic Central Precocious Puberty in Girls

BACKGROUND

Idiopathic central precocious puberty (ICPP) impairs child development, without early intervention. The current reference standard, the gonadotropin-releasing hormone stimulation test, is invasive which may hinder diagnosis and intervention.

PURPOSE

To develop a model for accurate diagnosis of ICPP, by integrating pituitary MRI, carpal bone age, gonadal ultrasound, and basic clinical data.

STUDY TYPE

Retrospective.

POPULATION

A total of 492 girls with PP (185 with ICPP and 307 peripheral precocious puberty [PPP]) were randomly divided by reference standard into training (75%) and internal validation (25%) data. Fifty-one subjects (16 with ICPP, 35 with PPP) provided by another hospital as external validation.

FIELD STRENGTH/SEQUENCE

T1-weighted (spin echo [SE], fast SE, cube) and T2-weighted (fast SE-fat suppression) imaging at 3.0 T or 1.5 T.

ASSESSMENT

Radiomics features were extracted from pituitary MRI after manual segmentation. Carpal bone age, ovarian, follicle and uterine volumes and endometrium presence were assessed from radiographs and gonadal ultrasound. Four machine learning methods were developed: a pituitary MRI radiomics model, an integrated image model (with pituitary MRI, gonadal ultrasound and bone age), a basic clinical model (with age and sex hormone data), and an integrated multimodal model combining all features.

STATISTICAL TESTS

Intraclass correlation coefficients were used to assess consistency of segmentation. Receiver operating characteristic (ROC) curves and the Delong tests were used to assess and compare the diagnostic performance of models. P < 0.05 was considered statistically significant.

RESULTS

The area under of the ROC curve (AUC) of the pituitary MRI radiomics model, integrated image model, basic clinical model, and integrated multimodal model in the training data was 0.668, 0.809, 0.792, and 0.860. The integrated multimodal model had higher diagnostic efficacy (AUC of 0.862 and 0.866 for internal and external validation).

CONCLUSION

The integrated multimodal model may have potential as an alternative clinical approach to diagnose ICPP.

EVIDENCE LEVEL

3.

TECHNICAL EFFICACY

Stage 2.

Adolescence and the Microbiome: Implications for Healthy Growth and Maturation

The gut microbiota was initially thought to develop into a stable, adult-like profile during early postnatal life. The formation of the gut microbiota during early life has been shown to contribute to healthy growth and has lifelong implications for host health. Adolescence, the developmental period between childhood and adulthood, is a critical window for healthy growth and maturation. The composition of the gut microbiota in adolescents is distinct from that of children and adults, which supports the premise that the gut microbiota continues to develop during adolescence toward an adult-like profile. Research has begun to shift its focus from understanding the gut microbiome at the extremes of the life span to evaluating the importance of the gut microbiome during adolescence and its role in healthy development. This article provides an overview of adolescent development, host-microbiota interactions, and experimental models used to discern effects of gut microbiota on health and disease. Herein, the role of the gut microbiota is reviewed as it relates to adolescent: i) brain development, cognition, and behavior; ii) metabolism and adiposity; and iii) skeletal growth and bone mass accrual. Future directions are addressed, including omics investigations defining mechanisms through which the gut microbiota influences adolescent development. Furthermore, we discuss advancing noninvasive interventions targeting the adolescent gut microbiota that could be employed to support healthy growth and maturation.