Abstract With the adoption of LC-MS/MS for the analysis of salivary steroids, a number of novel applications for salivary steroid analysis have been found. The convenience of salivary sampling and the good correlation of salivary hormones with free serum concentrations makes saliva analysis attractive for long term monitoring of testosterone replacement, CAH and prostate cancer treatment. The ability to take multiple samples at different times of the day and throughout the menstrual cycle can improve the diagnosis of conditions such as cyclical Cushing’s and PMOS, and the discovery of waking salivary cortisone as a diagnostic tool for the diagnosis of adrenal insufficiency has brought salivary steroid analysis to the forefront of research. Salivary steroid analysis has finally found its killer applications and there is a well-deserved resurgence in interest in this field.
Abstract Leptin regulates energy homeostasis through activation of its long-form receptor (LepRb), primarily via JAK2-dependent phosphorylation of STAT3. However, the temporal organization of leptin-induced transcriptional responses and how parallel signaling pathways contribute to these dynamics remain incompletely understood. Here, we established a LepRb-expressing hypothalamic cellular model to investigate the temporal architecture of leptin-induced transcription factors and pathways identified by transcriptome and proteome profiling at baseline (0 min), early (30 min), and late (180 min) time points. Overall changes in acute leptin stimulation were primarily reflected at the level of transcriptional and regulatory reprogramming. Proteomic remodeling mirrored the transcriptome but appeared smaller, likely due to assay insensitivity and slower dynamics of protein regulation, making the transcriptome the more informative kinetic readout. Structured transcriptional dynamics included the rapid activation of stress- and inflammatory-associated genes followed by sustained cytokine and interferon signaling modules. Transcription factor regulon and pathway activity inference identified coordinated activation of STAT, NF-κB, and MAPK-associated regulatory programs underlying these expression trajectories. CRISPR-Cas9-based deletion of Stat3 markedly altered basal transcriptional states and attenuated leptin-induced gene expression while revealing activation of alternative signaling pathways. In contrast, CRISPR-Cas9-based deletion of the ETS transcriptional repressor Etv6 strongly affected baseline transcription but had minimal impact on leptin-induced regulatory dynamics. Together, these findings reveal a temporally organized regulatory architecture in which STAT3 governs stimulus-responsive transcriptional dynamics, whereas ETV6 primarily modulates baseline transcriptional states.
Thyroid hormones (T3 and T4) play an essential role in reproductive health and can influence the functions of several endocrine and reproductive tissues, including ovaries, placenta, and mammary glands. Their interactions with other steroid hormones, such as glucocorticoids, estrogens, and progesterone, can alter the balance necessary for reproductive success. Hyperthyroidism can lead to significant endocrine dysregulation that affects multiple reproductive stages. This endocrine disorder causes several alterations in the estrous cycle, restricting conception when the condition is chronic. During pregnancy, hyperthyroidism may lead to several changes associated with preterm birth, which can adversely compromise subsequent lactation. Additionally, during lactation, excess thyroid hormones can impair both the development of the offspring and the extent of lactation by altering the mammary glands and the characteristics of the milk produced. This review explores the endocrine mechanisms behind the effects of experimental hyperthyroidism induced by T4 administration on reproduction. Furthermore, understanding iatrogenic-induced hyperthyroidism is vital for developing therapeutic strategies to mitigate its negative consequences on maternal and neonatal health.
Thyroid disease is a common endocrine disorder in pregnant women and is important to recognize. Clinical management relies on biochemical assessment of thyroid function and thyroid autoantibodies from a panel of routinely available tests. A challenge regarding biochemical assessment in pregnancy relates to the physiological adaptations that influence the analyses used for diagnosis and monitoring of maternal thyroid disease. The physiological adaptations include increased activity of the thyroid gland, an increase in the levels of binding proteins, and suppression of the immune system, which implies that biochemical test results should be interpreted in the context of pregnancy. This narrative review will discuss the biochemical assessment of thyroid function and thyroid autoantibodies in pregnancy, with a focus on the biochemical methods used and the interpretation of results, including strategies for the establishment of reference intervals. A key implication is that biochemical results obtained in pregnancy should be considered according to the timing of blood sampling and the biochemical method used. This is reflected by recommendations on the use of method- and trimester-specific reference intervals as part of clinical care, but similar considerations apply when thyroid function tests and thyroid autoantibodies are evaluated as part of population monitoring and used for definition of exposure in scientific outcome studies. Future research is encouraged to support the biochemical assessment and interpretation of thyroid function tests and thyroid autoantibodies in pregnancy. Future perspectives include advancements in biochemical methods and in the methodology applied for the establishment of reference intervals or clinical decision limits.
Hypoxia-inducible lipid droplet-associated protein (HILPDA) promotes hepatic lipid accumulation. Hilpda gene expression is directly regulated by hypoxia-inducible factors (HIF1A and HIF1B) and the nuclear receptor peroxisome proliferator-activated receptor alpha (PPARα). However, whether the expression of Hilpda is regulated by peroxisome proliferator-activated receptor gamma (PPARγ) in fatty liver remains unclear. In this study, we investigated the role of PPARγ in regulating Hilpda expression in fatty liver. Analysis of publicly available microarray datasets revealed that Hilpda expression is significantly increased in the fatty liver of patients with metabolic dysfunction-associated steatotic liver disease, as well as in obese and type 2 diabetes model ob/ob mice, high-fat diet-fed mice, and mice fed a high-fat, cholesterol-, and fructose-enriched diet, all of which exhibit elevated PPARγ expression. In contrast, Ppara/PPARA expression in the liver remained unchanged in mouse fatty liver models and was decreased in human MASLD liver samples. Hilpda expression in the fatty liver of ob/ob mice was further induced by PPARγ ligand treatment; however, this induction was significantly repressed in liver-specific PPARγ-deficient mice. Complementary in vitro analyses showed that ectopic expression and ligand activation of PPARγ in liver-derived AML-12 cells were sufficient to induce Hilpda transcription, whereas Hif1a and Hif1b were only modestly induced, indicating a minimal contribution of HIF-1 signaling. Overall, our study identifies Hilpda as a key component of the liver PPARγ-driven gene network, highlighting its role as a metabolic effector that adapts to pathological lipid accumulation.
