Defective jagged-1 signaling affects GnRH development and contributes to congenital hypogonadotropic hypogonadism.

In vertebrate species, fertility is controlled by gonadotropin-releasing hormone (GnRH) neurons. GnRH cells arise outside the central nervous system, in the developing olfactory pit, and migrate along olfactory/vomeronasal/terminal nerve axons into the forebrain during embryonic development. Congenital hypogonadotropic hypogonadism (CHH) and Kallmann syndrome are rare genetic disorders characterized by infertility, and they are associated with defects in GnRH neuron migration and/or altered GnRH secretion and signaling. Here, we documented the expression of the jagged-1/Notch signaling pathway in GnRH neurons and along the GnRH neuron migratory route both in zebrafish embryos and in human fetuses. Genetic knockdown of the zebrafish ortholog of JAG1 (jag1b) resulted in altered GnRH migration and olfactory axonal projections to the olfactory bulbs. Next-generation sequencing was performed in 467 CHH unrelated probands, leading to the identification of heterozygous rare variants in JAG1. Functional in vitro validation of JAG1 mutants revealed that 7 out of the 9 studied variants exhibited reduced protein levels and altered subcellular localization. Together our data provide compelling evidence that Jag1/Notch signaling plays a prominent role in the development of GnRH neurons, and we propose that JAG1 insufficiency may contribute to the pathogenesis of CHH in humans.

Urinary steroid profiling in women hints at a diagnostic signature of the polycystic ovary syndrome: A pilot study considering neglected steroid metabolites.

BACKGROUND: Although the polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women with vast metabolic consequences, its etiology remains unknown and its diagnosis is still made by exclusion. This study aimed at characterizing a large number of urinary steroid hormone metabolites and enzyme activities in women with and without PCOS in order to test their value for diagnosing PCOS. METHODS: Comparative steroid profiling of 24h urine collections using an established in-house gas-chromatography mass spectrometry method. Data were collected mostly prospectively. Patients were recruited in university hospitals in Switzerland. Participants were 41 women diagnosed with PCOS according to the current criteria of the Androgen Excess and PCOS Society Task Force and 66 healthy controls. Steroid profiles of women with PCOS were compared to healthy controls for absolute metabolite excretion and for substrate to product conversion ratios. The AUC for over 1.5 million combinations of metabolites was calculated in order to maximize the diagnostic accuracy in patients with PCOS. Sensitivity, specificity, PPV, and NPV were indicated for the best combinations containing 2, 3 or 4 steroid metabolites. RESULTS: The best single discriminating steroid was androstanediol. The best combination to diagnose PCOS contained four of the forty measured metabolites, namely androstanediol, estriol, cortisol and 20ßDHcortisone with AUC 0.961 (95% CI 0.926 to 0.995), sensitivity 90.2% (95% CI 76.9 to 97.3), specificity 90.8% (95% CI 81.0 to 96.5), PPV 86.0% (95% CI 72.1 to 94.7), and NPV 93.7% (95% CI 84.5 to 98.2). CONCLUSION: PCOS shows a specific 24h urinary steroid profile, if neglected metabolites are included in the analysis and non-conventional data analysis applied. PCOS does not share a profile with hyperandrogenic forms of congenital adrenal hyperplasias due to single steroid enzyme deficiencies. Thus PCOS diagnosis by exclusion may no longer be warranted. Whether these findings also apply to spot urine and serum, remains to be tested as a next step towards routine clinical applicability.

Experimental gingivitis in type 1 diabetics: a controlled clinical and microbiological study.

OBJECTIVE: To monitor clinical and microbiological changes during experimental gingivitis in type 1 diabetics and non-diabetics. MATERIALS AND METHODS: Nine type 1 diabetics with good/moderate metabolic control and nine age-gender matched non-diabetics were recruited. Probing pocket depths in all subjects did not exceed 4 mm and none were affected by attachment loss. According to the original model, an experimental 3-week plaque accumulation resulting in experimental gingivitis development and a subsequent 2-week period of optimal plaque control were staged. Subgingival plaque samples were collected at days 0, 21 and 35 from one site per quadrant, pooled and analysed using checkerboard DNA-DNA hybridization. RESULTS: Diabetics (mean age 25.6+/-5.8 standard deviation (SD), range 16-35 years) had a mean HbA1c level of 8.1+/-0.7% (SD), while non-diabetics (mean age 24.8+/-5.7 (SD), range 15-36 years) were metabolically controlled (HbA1c< or =6.5%). Between Days 0, 21 and 35, no statistically significant differences in mean plaque and gingival index scores were observed between diabetics and non-diabetics. At days 7 and 21, however, diabetics showed statistically significantly higher percentages of sites with gingival index scores > or =2 compared with non-diabetics. Mean DNA probe counts of the red and orange complex species increased significantly (p<0.05) between days 0 and 21 and decreased significantly (p<0.05) between days 21 and 35 in both groups. CONCLUSION: Both diabetics and non-diabetics react to experimental plaque accumulation with gingival inflammation. Type 1 diabetics, however, develop an earlier and higher inflammatory response to a comparable bacterial challenge.