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The Journal of Steroid Biochemistry and Molecular Biology

Elsevier BV

Preprints posted in the last 90 days, ranked by how well they match The Journal of Steroid Biochemistry and Molecular Biology's content profile, based on 11 papers previously published here. The average preprint has a 0.01% match score for this journal, so anything above that is already an above-average fit.

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Estriol is a Stronger Transcriptional Activator than is either 17beta-Estradiol or Estrone of Hu-man and Elephant Shark Estrogen Receptor-alpha and Estrogen Receptor-beta transfected into COS-7 Cells

Ao, Y.; Cabizares, R. M. d. R.; Baker, M. E.; Katsu, Y.

2026-07-09 evolutionary biology 10.64898/2026.07.03.736429 medRxiv
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Humans and other vertebrates contain two estrogen receptors (ERs), ER-alpha and ER-beta, which mediate the physiological actions of three estrogens: estrone (E1), estradiol (E2) and estriol (E3). Of these three estrogens, in vivo, E2 is the strongest transcriptional activator of ER-alpha and ER-beta, E1 is next most active, followed by E3. We studied transcriptional activation of human ER-alpha and ER-beta by E2, E1 and E3 in African green monkey kidney (COS-7) cells, which we compared with studies of estrogen stimulation of ER transcription in human em-bryonic kidney (HEK-293) cells. To our surprise, in COS-7 cells, E3 had the lowest half-maximal response (EC50) for human ER-alpha and ER-beta than either E2, which was second most active estrogen, or E1. In contrast, for human ER-alpha and ER-beta transfected into HEK-293 cells, E2 was the most active estrogen, followed by E1 and E3. Similar results were found in COS-7 cells and HEK-293 cells transfected with elephant shark ER-alpha and ER-beta. Thus, under some conditions, E3 is a more active estrogen than either E2 or E1. This suggests that E3 may be a novel physiological ligand for the ER in some mammalian cells.

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Measurement of a panel of 21 steroids in a quantitative assay in human plasma, adipose tissue, and fecal samples using ultra-high-performance liquid chromatography-tandem mass spectrometry

Evstafev, I.; Krakstrom, M.; Saarinen-Aaltonen, N.; Hakkarainen, J.; Hakkinen, M. R.; Auriola, S.; Bostrom, P. J.; Poutanen, M.; Oresic, M.; Dickens, A. M.

2026-07-09 biochemistry 10.64898/2026.07.08.737297 medRxiv
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Comprehensive detection of steroids, beyond the limited panels typically analyzed in clinical chemistry laboratories, has become increasingly important given their pivotal roles in diverse biological processes. However, steroid quantification poses several analytical challenges, including differences in ionization efficiency and structural similarities across the entire steroid metabolic network. To address these challenges, we developed a targeted ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) assay to analyze 21 steroids using reverse-phase chromatography combined with rapid polarity switching. Mass spectrometry (MS) analysis was performed in scheduled multiple reaction monitoring (sMRM) mode. Depending on the steroid and matrix, the validated lower limits of quantitation (LLOQ) ranged from 12.0 pM to 1216 pM in plasma and 41.1 pM to 384 pM in fecal sample homogenates. In adipose tissue, it was from 0.01 pmol/g to 9 pmol/g. Measured steroid concentrations obtained from the commercial control samples (MassTrak Steroid Serum QC Set 1 and the MassCheck Steroid Panel 1 Serum Control) showed close agreement with the reference values. As a proof of concept, the method was successfully applied to 469 plasma samples in several projects, 15 adipose tissue samples, and 332 fecal samples, demonstrating its applicability to large-scale studies. In conclusion, the method enables sensitive, derivatization-free quantification of an expanded steroid panel in plasma and complex biological matrices, including adipose tissue and fecal samples, representing a significant advancement in comprehensive steroid profiling.

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Isotretinoin use is associated with persistent alterations in male reproductive function

Bendix, F.; Priskorn, L.; Joergensen, N.; Frederiksen, H.; Jorgensen, A.; Morch, L.; Ring, H. C.; Kolla, S.; Rosenmai, A. K.; Svingen, T.; Juul, A.; Rehfeld, A.

2026-07-27 sexual and reproductive health 10.64898/2026.07.22.26356991 medRxiv
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Background Isotretinoin (ISO) is a systemic retinoid widely used for the treatment of acne vulgaris, yet its potential effects on male reproductive function remain unclear with previous studies reporting inconsistent findings. Methods and finding We conducted a multi-model study combining data from the Danish Young Men Study (DYMS) cohort with ex vivo cultured human testis tissue and an in vitro Retinoic Acid Receptor alpha (RAR) reporter gene assay. In the DYMS cohort semen parameters and reproductive hormone concentrations assessed on a specific examination day were compared between ISO-users (n=322) and non-users (n=4,065). Ex vivo human testis tissue was exposed to ISO and RA for 96 hours to assess changes in hormone secretion and germ cell dynamics, while the in vitro RAR assay evaluated ISO for effects on RA-induced RAR-signaling. In the DYMS cohort, ISO use was associated with reduced FSH concentrations, higher inhibin B/FSH ratio, and elevated estradiol concentrations, along non-significant tendencies of lower sperm counts. These associations persisted even after cessation of ISO use but were not evident in men first initiating ISO use 1 year after their examination date. In the ex vivo testis tissue, ISO exposure altered hormone secretion, including increased testosterone, but did not affect germ cell proliferation or apoptosis. ISO also inhibited RA-induced RAR-signaling in vitro in a competitive manner. Conclusions These findings suggests that ISO-use may influence male reproductive function, potentially with persistent effects. Further randomized clinical trials are needed to validate these effects.

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Evaluation of Sex Hormones in Autoimmune Diseases in Pre- and Post-Menopausal Women

Krishnamurthy, H.; Yang, Y.; Song, Q.; Krishna, K.; Jayaraman, V.; Wang, T.; Bei, K.; Rajasekaran, J. J.

2026-08-22 endocrinology 10.64898/2026.08.19.26360795 medRxiv
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Autoimmune diseases have shown biased proportion in female population, existing clinical investigations of sex hormones in autoimmune populations have been relatively limited in terms of patient size and types of hormones investigated. In this study, we examined the relationship of sexual hormones and autoimmune antibodies in a large cohort of US women. This retrospective study sample included a total of 15319 female subjects medical information that were collected between December 2015 to May 2019 and tested in the Vibrant America Clinical Laboratory. The present serum sample was limited to female participants who had ever menstruated at the time of blood collection and completed the testing of the autoimmune antibodies and sex hormones. We focused on a total of 13 clinically significant autoantibodies including antinuclear antibody (ANA), 11 anti-extractable nuclear antigens (anti-ENAs), anti-cyclic citrullinated peptide 3 (anti-CCP3), and 11 female sex hormones. First, the prevalence of serological autoantibodies in a large set of adult female subjects divided by the menopause age was investigated. Next, the levels of sex hormones were compared in the seropositive autoimmune subjects and seronegative controls across the pre- and post-menopausal female groups. The presented study involving a large cohort of females showed no statistically different levels of sex hormones in seropositive autoimmune subjects and matched controls except for DHEA-s.

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Unraveling a fine balance between ferroptosis, lipid metabolism, and hormonal protection in Leydig cell steroidogenesis

Benzo, Y.; Dattilo, M. A.; Raggio, M. A.; Lopez, P. F.; Vinals, D. F.; Theas, M. S.; Poderoso, C.; Maloberti, P. M.

2026-07-10 cell biology 10.64898/2026.07.03.736405 medRxiv
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Leydig cells (LCs) are essential for male reproductive function due to their role in testosterone synthesis, a process critically dependent on mitochondrial cholesterol transport mediated by the Steroidogenic Acute Regulatory protein (StAR). Despite their importance, LCs are highly sensitive to metabolic and exogenous stressors. Ferroptosis, an iron-dependent form of regulated cell death driven by lipid peroxidation, has emerged as a key link between cellular metabolism and cell fate; however, its role in LCs and steroidogenesis remains poorly understood. In this study, we investigated the induction of ferroptosis in LCs and its impact on their steroidogenic capacity. We evaluated cellular responses to canonical ferroptosis inducers (Erastin and RSL3) alongside the transcriptional regulation of key genes. Our results demonstrate that LCs are vulnerable to ferroptotic stress, which significantly downregulates Star expression. Notably, we uncovered a novel endocrine-metabolic crosstalk: hormonal stimulation via hCG effectively rescues LCs from Erastin-induced toxicity and fully sustains maximal steroidogenesis. However, this hormone-driven cytoprotection fails against direct GPX4 inhibition by RSL3, indicating an absolute reliance on functional GPX4. These mechanistic findings highlight the paradoxical dual role of ACSL4 in Leydig cell biology and are further supported by bioinformatic analysis of public transcriptomic profiles from infertile patients, which reveal a detrimental imbalance in the ACSL4/GPX4 axis. Together, our data position ferroptosis as a critical disruptor of male endocrine function and reveal a hormone-mediated metabolic adaptation that could inform novel therapeutic strategies against oxidative stress in the testis. Highlights-Leydig cells exhibit a strong vulnerability to ferroptotic cell death. -Ferroptosis disrupts StAR expression and halts Leydig cell steroidogenesis. -hCG signaling promotes metabolic adaptation against Erastin-induced ferroptosis.

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A sensitive fluorometric assay to detect aldo-keto reductase and carbonyl reductase activity based on a naphthaldehyde derivative

Piazza, L.; Pequerul, R.; Pares, X.; Balestri, F.; Signore, G.; Del Corso, A.; Farres, J.

2026-06-16 biochemistry 10.64898/2026.06.15.732224 medRxiv
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We have developed a fluorometric assay for detecting reductase activity in biological samples through 4-methoxy-1-naphthalenemethanol (MONOL-41) formation. The enzyme carbonyl reductase 1 (CBR1) and four members of the aldo-keto reductase (AKR) 1 family (AKR1A1, AKR1B1, AKR1B10, AKR1C3) were evaluated for their ability to reduce 4-methoxy-1-naphthaldehyde (MONAL-41). AKR1B1 and CBR1 followed Michaelis-Menten kinetics, whereas AKR1B10, AKR1A1, and AKR1C3 showed substrate inhibition above 10 {micro}M (70 {micro}M for AKR1C3). Among the tested enzymes, AKR1B10 displayed the highest catalytic efficiency in the absence of substrate inhibition. The MONOL-41 assay was compared with the standard NADPH-based method, showing improved sensitivity, robustness, and lower detection limits (0.77 {micro}g/mL vs. 1.49 {micro}g/mL). These results confirm its suitability for monitoring AKR1B10 activity. The assay was then applied to A549 cell extracts, which express multiple reductases. Activity decreased at substrate concentrations above 10 {micro}M, suggesting a predominant role of AKR1B10. Inhibition studies using tolrestat and high MONAL-41 concentrations indicated a limited contribution of CBR1 ([~]7-8%). Considering both catalytic efficiency and expression levels, AKR1B10 appears to be the main contributor to reductase activity in this model. In A549 living cells, MONAL-41 showed no cytotoxicity up to 50 {micro}M and enabled real-time monitoring due to its membrane permeability. However, oxidation by aldehyde dehydrogenases can generate MONOIC-41, which has similar spectral properties but a lower quantum yield, potentially affecting signal interpretation. Overall, this assay represents a sensitive and cost-effective tool for detecting reductase activity and screening inhibitors.

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Cortisol Drives Pregnancy-Associated Induction of Hepatic OAT2, NTCP, and OCT1 in HepaRG cells Through GR-, HNF1α-, and HNF4α-Dependent Signaling

Sharma, S.; Tsang, Y. P.; Unadkat, J. D.

2026-06-19 pharmacology and toxicology 10.64898/2026.06.15.732466 medRxiv
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Pregnancy induces or represses hepatic drug metabolism. Whether pregnancy affects hepatic drug transport is unexplored. We previously showed that a cocktail of pregnancy-related hormones (PRHC) induces mRNA expression and activity of sodium/taurocholate cotransporting polypeptide (NTCP), organic anion transporter 2 (OAT2), and organic cation transporter 1 (OCT1, mRNA only) in differentiated HepaRG cells. Here, using HepaRG cells, we identified cortisol as the hormone primarily responsible for this induction and explored the underlying mechanisms. Clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9-mediated knockdown studies in HepaRG cells showed that the glucocorticoid receptor (GR) is the primary mediator of this response. GR knockdown markedly attenuated cortisol-induced NTCP, OAT2, and OCT1 mRNA expression and activity. Cortisol also induced the mRNA expression of regulatory factors, including pregnane X receptor (PXR), constitutive androstane receptor (CAR), and hepatocyte nuclear factor (HNF) 4 alpha (HNF4). HNF4 knockdown selectively attenuated OAT2 and OCT1 induction, whereas HNF1 knockdown enhanced NTCP induction, attenuated OCT1 induction, and reduced basal organic anion transporting polypeptide 1B1 (OATP1B1) expression. In contrast, knockdown of CAR or PXR did not significantly alter cortisol-mediated transporter regulation. These data identify cortisol as the principal PRH driving regulation of the hepatic OAT2, NTCP, and OCT1 in HepaRG cells and indicate that this response is mediated primarily by GR, with selective downstream contributions from HNF4 and HNF1. These findings provide mechanistic insights into pregnancy-associated changes in hepatic transporter-mediated drug disposition, including when antenatal corticosteroids are administered to pregnant women to prevent respiratory distress syndrome in their prematurely born infants. Significance StatementThe extent and mechanisms by which pregnancy-related hormones regulate hepatic uptake transporters remain poorly defined. This study identifies cortisol as the principal pregnancy-related hormone driving NTCP, OAT2, and OCT1 induction in HepaRG cells and shows that this response is mediated primarily through GR, with transporter-specific contributions from HNF4 and HNF1.

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In vitro EAS-mediated activity of Alternaria toxins

Spilioti, E.; Spyropoulou, A.; Gate, L.; Lorcin, M.; Machera, K.; Nestora, A.; Repouskou, A.; Theologidis, I.; Marko, D.; Behr, A.-C.

2026-07-13 pharmacology and toxicology 10.64898/2026.07.09.737498 medRxiv
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Alternaria mycotoxins represent an emerging concern due to their frequent occurrence in food and feed. However, available toxicological data remain limited. Under the current EU regulatory framework, and in line with the EFSA/ECHA/JRC guidance for the identification of endocrine disruptors (EDs), assessment of endocrine activity relies on standardized assays performed according to OECD Test Guidelines (TGs) for the estrogen-, androgen- and steroidogenesis- (EAS) modalities. Within the framework of the European Partnership for the Assessment of Risks from Chemicals (PARC), standardized in vitro methods of regulatory relevance were performed for six chemically characterized Alternaria toxins, aiming to address current regulatory gaps on EAS-mediated activity. Alternariol (AOH), alternariol monomethyl ether (AME), tenuazonic acid (TeA), altertoxin-I (ATX-I), tentoxin (TEN) and altenuene (ALT) were assessed over a broad concentration range, from 0.001 up to 60 M, depending on cytotoxicity and solubility profile of each compound. Our findings indicate estrogenic activity for AOH (PC50: 3.9 - 4.6 {micro}M) and AME (PC50: 5.2 - 8.5 {micro}M) in the estrogen receptor transactivation assay (OECD TG 455), as well as an anti-estrogenic activity for ATX-I (IC30: 0.27 - 0.37 {micro}M). Minimal positive responses were observed at high concentrations for AOH (from the dose of 3 {micro}M) and for AME (from the dose of 10 {micro}M) in the agonistic part of the androgen receptor transactivation assay (OECD TG 458), which may also reflect glucocorticoid receptor activation. No effects on estradiol or testosterone production were observed for any of the tested Alternaria compounds in the steroidogenesis assay (OECD TG 456).

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Hepatic estrogen receptor α is required for stage-specific coupling of liver metabolism and proliferation during pregnancy

Meda, C.; Dolce, A.; Talamazzini, G.; Ohlsson, C.; Carli, F.; Infelise, P.; Gastaldelli, A.; Maggi, A.; Della Torre, S.

2026-08-18 pharmacology and toxicology 10.64898/2026.08.10.743939 medRxiv
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Background and AimsPregnancy requires dynamic, stage-specific adaptations in maternal liver metabolism and growth to sustain fetal development while preserving systemic homeostasis. Estrogen signaling, which significantly increases during pregnancy, is primarily mediated in hepatocytes by estrogen receptor (ER). Although hepatic ER regulates female liver metabolism under non-pregnant conditions, its role in pregnancy-induced hepatic remodeling remains unclear. MethodsWe studied non-pregnant and pregnant control and liver-specific ER knockout (LERKO) mice across gestational stages using longitudinal physiological measurements, liver transcriptomics, targeted metabolomics, histological assessment of cell proliferation, and metabolic phenotyping. ResultsIn control mice, pregnancy elicited sequential hepatic remodeling characterized by early induction of cell-cycle programs, a mid-gestational peak in hepatocyte proliferation with transient suppression of selected metabolic pathways, and late reactivation of specific metabolic programs. Chronic hepatic ER deficiency alters this temporal pattern. LERKO livers showed premature activation of proliferative and anabolic transcriptional programs, changes in amino acid- and fatty acid-related metabolic pathways, and altered temporal regulation of AKT-mTORC1-related signaling. At mid-gestation, LERKO mice displayed reduced hepatocyte proliferation, altered expression of metabolic and insulin-related genes, blunted gestational glucose adaptation without overt evidence of systemic insulin resistance, and changes in the light/dark-phase metabolic patterns. ConclusionsThese findings suggest that hepatic ER is required for the appropriate stage-specific coupling of liver growth, metabolic remodeling, and insulin-responsive signaling during pregnancy. Its loss is associated with gestational hepatic maladaptation and systemic metabolic phenotypes, providing a framework for investigating estrogen-dependent mechanisms underlying pregnancy-associated metabolic and liver disorders. HighlightsHepatic ER is required for stage-specific liver remodeling during pregnancy. Loss of hepatic ER alters temporal coupling of liver growth and metabolism. LERKO mice show early changes in amino acid- and fatty acid-related pathways. Hepatic ER loss reduces proliferation and alters gestational glucose adaptation. Hepatic ER loss is associated with altered light/dark-phase metabolic organization. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=80 SRC="FIGDIR/small/743939v1_ufig1.gif" ALT="Figure 1"> View larger version (25K): org.highwire.dtl.DTLVardef@d52bborg.highwire.dtl.DTLVardef@b27511org.highwire.dtl.DTLVardef@23b286org.highwire.dtl.DTLVardef@19d9314_HPS_FORMAT_FIGEXP M_FIG C_FIG

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Sustained GnRH Agonism Alters Endocrine Dynamics and Pubertal Progression in Juvenile Rats

Niepsuj, T.;Nurani, R.;Oliveira, G.;Johnson, A.;Nguyen, A.;Ebert, K.;Farhat, W.;Jorgensen, J.;Auger, A.

2026-06-29 Developmental Biology 10.64898/2026.06.26.734882 medRxiv
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Purpose: Gonadotropin releasing hormone (GnRH) agonists are clinically used to delay pubertal progression by suppressing the hypothalamic-pituitary-gonadal (HPG) axis. While GnRH agonists have long been used clinically, the developmental characterization of HPG axis suppression during puberty remains incompletely understood. Thus, we examined the effects of GnRH receptor agonism in juvenile rats. Hypothesis: Sustained GnRH receptor agonism will result in lower gonadal mass, blunt peripheral pubertal landmarks, and alter hormonal signaling dynamics within the HPG axis. Methods: Animals received a single injection of extended-release leuprolide acetate depot (LA) or vehicle control on postnatal day (PND) 23. Animals were assessed for body mass and peripheral markers of puberty. On PND 44, animals were euthanized and tissues were evaluated to assess additional markers of pubertal maturation, pituitary gene transcript levels, and hormone concentrations in serum and gonads. Results: In females, LA treatment resulted in a smaller gonad size, increased body mass, and less vaginal openings. In males, LA treatment resulted in smaller gonads but did not significantly alter body mass or preputial separation. In the pituitary, LA-treated rats had lower Gnrhr, Fshb, and Lhb transcript levels regardless of sex, while females exhibited higher Cga and Nr5a1. Serum FSH and ACTH were lower in LA-treated animals, and treated females also had lower progestins and androstenedione, and higher LH. Conclusions: LA treatment reduced aspects of pubertal maturation and HPG axis output, with sex specific outcomes. These findings highlight the need for integrated, multi-level approaches to understand how altered GnRH signaling impacts pubertal and long-term physiology.

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Differential induction of 14-3-3 paralogs expression during early and late adipogenesis

del Veliz, S.; Muller, S.; Aguilera, J. N.; Gojanovich, A. D.; Uhart, M.; Lim, G.; Bustos, D. M.

2026-08-04 biochemistry 10.64898/2026.08.03.742103 medRxiv
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Obesity is a major public health challenge of the 21st century, particularly in low- and middle-income populations. Adipogenesis plays a central role in the development of obesity and associated metabolic disorders, as it determines adipocyte number, size, and function. The 14-3-3 protein family comprises seven paralogs in mammals that regulate multiple cellular processes, yet their specific roles during adipogenesis remain poorly understood. In this study, we characterized the expression profiles of 14-3-3 paralogs during the early and late stages of adipogenic differentiation using quantitative PCR under standard adipogenic differentiation medium and modified drug-supplemented conditions. We found that the expression of specific paralogs is strongly influenced by the composition of the differentiation medium. The absence of insulin led to an early increase in Ywhaz, which could not be maintained during late adipogenesis and was associated with impaired adipogenic differentiation. In contrast, stimulation with incretins in combination with insulin induced late expression of Ywhag and Ywhab paralogs and promoted the formation of a greater number of smaller lipid droplets. These findings indicate that individual 14-3-3 paralogs exert distinct and context-dependent effects on adipogenesis, highlighting their potential roles as modulators of adipocyte differentiation and metabolic function.

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Ergothioneine, alone or combined with vitamin K2, vitamin D3 and magnesium L-threonate, attenuates bone turnover, inflammatory and oxidative disturbances in ovariectomized mice

Liu, W.; Tang, Y.; Ding, W.; Cao, J.; Guo, C.; Xiao, G.

2026-06-25 pharmacology and toxicology 10.64898/2026.06.23.734114 medRxiv
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PurposeEstrogen deficiency drives bone loss through interacting endocrine, oxidative, inflammatory and bone-remodeling disturbances. Ergothioneine (EGT) is a diet-derived thiol/thione antioxidant whose effects on the estrogen-deficient skeleton are unknown. We evaluated whether EGT, alone or combined with vitamin K2, vitamin D3 and magnesium L-threonate, attenuates the skeletal and systemic consequences of ovariectomy (OVX) in mice. MethodsForty-eight female C57BL/6J mice underwent sham surgery or OVX and received daily oral gavage for 12 weeks of vehicle, alendronate (1.53 mg/kg), EGT (30 mg/kg/day), EGT with vitamin K2 (40 {micro}g/kg/day) and vitamin D3 (500 IU/kg/day), or EGT with vitamin K2, magnesium L-threonate (350 mg/kg/day) and vitamin D3 (n = 5-6 analysed per group). Outcomes included the uterine index, tibial micro-computed tomography, distal-femoral histology, and serum bone turnover markers (CTX-I, PINP, osteocalcin), sex hormones, TNF-, IL-6, SOD and MDA. OVX lowered the uterine index and induced tibial trabecular deterioration, with increased CTX-I, decreased PINP and osteocalcin, elevated TNF- and IL-6, reduced SOD and increased MDA (all P < 0.01 vs sham). Alendronate restored tibial micro-CT bone-volume fraction (BV/TV) and trabecular number (P < 0.01 vs OVX). The EGT-based regimens did not significantly restore tibial micro-CT BV/TV, trabecular thickness or trabecular number (all P > 0.05 vs OVX), but significantly increased trabecular area on distal-femoral histology (OVX 7.6% vs 14.2-15.0% across regimens; P < 0.05 vs OVX) and lowered CTX-I, TNF-, IL-6 and MDA while raising SOD and partially restoring PINP and osteocalcin (P < 0.05-0.01 vs OVX). Because the histological and micro-CT endpoints were assessed at different skeletal sites, structural interpretation is cautious. Apparent increases in serum estradiol were assay-dependent and are regarded as exploratory. Ergothioneine-based nutritional regimens improved the systemic oxidative, inflammatory and bone-turnover environment of estrogen-deficient bone loss and preserved distal-femoral trabecular area on histology, although tibial three-dimensional microarchitecture by micro-CT was not restored. Because the histological and micro-CT endpoints were assessed at different skeletal sites, the structural interpretation is necessarily cautious. These findings support further evaluation of EGT as a dietary adjunct, with mechanistic and dose-optimization studies warranted.

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Effects of a Maternal Ketogenic Diet on Maternal and Offspring Metabolic Health in Mice

Ruano, A. H.; Kracaw, R. A.; Cervantes, I. A.; Ruano, S. H.; Tacam, M. J.; Pennington, K. A.

2026-08-04 physiology 10.64898/2026.07.30.741686 medRxiv
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Ketogenic (keto) diets have gained popularity due to their potential benefits on weight loss and metabolic conditions. However, the consequences of consuming a keto diet before, during, and after pregnancy on maternal and offspring health remain incompletely understood. To investigate this, female Swiss Webster mice were randomly assigned to either a keto or control diet. After 6 weeks on diet, females were mated and maintained on their respective diets throughout pregnancy and lactation. In experiment 1, glucose tolerance tests (GTT) were performed on pregnant dams at gestational day (GD) 16.5. At GD 17.5, dams were euthanized, urine was collected for ketone analysis, and fetal and placental weights were recorded. In experiment 2, dams delivered naturally and one male and one female offspring per dam were retained and weighed weekly. At 12 weeks of age, offspring underwent GTT, followed by euthanasia and serum collection for insulin and leptin analysis. Compared with controls, keto dams exhibited increased body weight, impaired glucose tolerance, elevated urinary ketones, and reduced circulating insulin during late gestation (p<0.05). Fetuses from keto dams were significantly smaller (p<0.05), whereas placental weight and placental efficiency were unchanged. Offspring from keto dams weighed less than controls during early postnatal development but demonstrated catch-up growth by 12 weeks of age. At 12 weeks, keto offspring exhibited a modest but statistically significant improvement in glucose tolerance compared to control offspring (p<0.05). Male keto offspring had significantly decreased serum insulin (p<0.05) compared to male control offspring, while no differences were observed in females. Serum leptin levels did not differ between diet groups, although sex differences present in control offspring were not observed in keto offspring. Together, these findings suggest that maternal ketogenic diet consumption is associated with altered maternal glucose homeostasis during pregnancy and reduced fetal growth in this mouse model. Although offspring exhibited only modest metabolic alterations during early adulthood, the observed changes in growth trajectory and sex-specific metabolic profiles support further investigation into the long-term consequences of maternal ketogenic diet exposure during pregnancy.

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Increases in serum corticosterone level and diuresis induced by the selective kappa opioid receptor (KOR) agonist U50,488H are unaffected by KOR phosphorylation

Zhao, P.; Bland, K.; Khandeshi, S.; Huang, P.; Liu-Chen, L.-Y.

2026-07-16 pharmacology and toxicology 10.64898/2026.07.10.737784 medRxiv
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PurposeWe previously showed that mice expressing a phosphorylation-deficient kappa opioid receptor mutant (K4A) exhibited reduced U50,488H-induced anti-scratching tolerance in males and reduced conditioned place aversion in females, without changes in acute anti-scratching or hypo-locomotor effects. Here, we examined whether K4A mutations, which markedly diminish {beta}-arrestin-mediated signaling, alter U50,488H-induced increases in serum corticosterone and urine output. MethodsK4A and wildtype mice received U50,488H (5 mg/kg, s.c.) or saline. Serum corticosterone was measured by ELISA 1 h later. Urine was collected for 1 h beginning 10 min after injection. ResultsU50,488H increased serum corticosterone to similar levels in wildtype and K4A mice of both sexes. Basal corticosterone levels were higher in females than males regardless of genotype. U50,488H also significantly increased urine output in both sexes, with no genotype differences. However, the increase in urine output was greater in males than females. ConclusionsKOR phosphorylation and associated {beta}-arrestin-mediated signaling are not required for U50,488H-induced increases in serum corticosterone or diuresis in either sex. These findings also demonstrate, for the first time, that KOR activation produces greater diuresis in male than female mice.

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Precision Management of Fludrocortisone-Related Hypertension Risk in Congenital Adrenal Hyperplasia: A Machine Learning Approach to Personalized Dosing

Du, S.; Chen, Z.; Zhu, G.; Li, T.; Deng, W.; Ji, W.; Yuan, Y.; Ba, Y.; Wang, X.; Li, R.

2026-07-23 endocrinology 10.64898/2026.07.22.26358644 medRxiv
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Congenital adrenal hyperplasia (CAH) is a rare inherited disorder requiring lifelong hormone replacement therapy. Excessive hormone replacement poses a significant risk for long-term complications, such as hypertension; however, quantitative approaches for optimizing dosing remain underdeveloped. This study aimed to identify factors associated with hypertension in patients with CAH and to develop a predictive model to support longitudinal fludrocortisone dose adjustment in pediatric patients who were already receiving mineralocorticoid replacement. We first employed generalized linear mixed models (GLMM) to evaluate the relationships among therapeutic agents, biochemical markers, and hypertension. Our results indicated a significant positive association between the dose of fludrocortisone (FC) and diastolic hypertension, whereas no such association was observed for the dose of hydrocortisone (HC). Using expert curated data, we subsequently constructed multiple predictive models, including CatBoost, XGBoost, and LightGBM, to enable individualized adjustment of FC dosage. All models were evaluated on an independent test set, with CatBoost, XGBoost, and LightGBM demonstrating comparably strong performance (R^2: 0.75 to 0.77). Subgroup analyses revealed that predictive accuracy was highest in children aged 0 to 2 years, where the top-performing model achieved a mean ideal prediction rate of 59.6%. This study not only confirms the significant link between FC dosing and hypertension in CAH patients but also provides a machine learning based decision support tool to assist individualized longitudinal dose adjustment. The model shows promise as a clinical decision-support instrument to facilitate personalized and precise management of CAH therapy.

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Preliminary In Vitro Evaluation Of Naringin And Quercetin For Potential Bioenhancement Of Andrographolide Using Plasma Protein Binding And Hepatic Microsomal Stability Assays

Pisipati, P.; Paranjpe, T.; Natu, S.; Khan, A.; Salgotra, V.

2026-08-12 pharmacology and toxicology 10.64898/2026.08.06.743340 medRxiv
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Several potentially potent anticancer drugs have been identified by in vitro evaluation, such as Andrographolide. These compounds show strong anticancer activity in vitro, but struggle to reach effective concentrations in the bloodstream when taken orally because they dissolve poorly in water or break down rapidly in the body. Bioenhancers, which are compounds that have potential to improve drug stability in the body, offer an alternative solution to overcome this limitation. Naringin and Quercetin have been identified as candidate bioenhancers, and have been hypothesized to potentially slow rapid first pass metabolism of poorly bioavailable drugs. Our work focuses on testing Naringin and Quercetin because they are flavonoids with therapeutic potential, due to their anti-inflammatory and antioxidant properties. Data from the hepatic microsomal assays performed on Naringin and Quercetin suggest moderate to proficient periods of stability in the body, with Naringin having 91.86% remaining, while Quercetin had 74.84% remaining. When administered alongside Andrographolide, a drug known to rapidly degrade in the body, Naringin raised its metabolic stability from 38.93% to 80.77% and on the other hand, Quercetin raised Andrographolide metabolic stability from 38.93% to 86.70%. In addition, plasma protein binding assays show the percentage of compounds available at the target site where Naringin was observed to be 49.32% bound and Quercetin found to be 50.14% bound, implying 50.68% of Naringin, and 49.86% of Quercetin available at the target site, respectively. This preliminary study explores whether Quercetin and Naringin could act as bioenhancers by remaining stable and available in plasma and by slowing the metabolism of poorly bioavailable drugs such as Andrographolide.

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In vivo acquired resistance to tamoxifen is associated with irreversible loss of IGF1R, upregulation of insulin receptor and enhanced sensitivity to insulin

Hoff, K.;Periakaruppan, P.;Irizarry, V.;Baar, C.;Sachdev, D.

2026-06-11 Cancer Biology 10.64898/2026.06.08.727558 medRxiv
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Selective estrogen receptor modulators (SERMs) like tamoxifen are used to treat hormone receptor positive (HR+) breast cancers. Several models of in vitro acquired resistance to tamoxifen using HR+ breast cancer cell lines have been developed. There are few models of resistance to tamoxifen that are generated in vivo. Here, we generated a model of in vivo resistance to tamoxifen. We show that in vivo tamoxifen resistance is associated with loss of IGF1R. This loss is irreversible as it persists even when tamoxifen is removed. In vivo tamoxifen resistance is also associated with upregulation of insulin receptor, specifically the A isoform of IR (IR-A). These resistant cells show enhanced insulin sensitivity compared to the parental endocrine sensitive or in vitro acquired tamoxifen resistant cells. Finally, we demonstrate that in vivo resistance to tamoxifen results in enhanced proliferation in response to insulin. These studies establish that some mechanisms of in vivo resistance to tamoxifen differ from those observed for in vitro acquired resistance and increased dependence on insulin signaling drives endocrine resistance in HR+ breast cancer. Taken together, these studies present that targeting IR-A in combination with newer targets of tamoxifen resistance could be tested in endocrine resistant breast cancer.

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No single biological phenotype exists in polycystic ovary syndrome: evidence from cross-space phenotyping

Piorkowska, N. J.; Ostromecki, A.; Franik, G.; Bizon, A.

2026-07-10 endocrinology 10.64898/2026.07.09.26357636 medRxiv
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Context Polyendocrine metabolic ovarian syndrome (PMOS), formerly known as polycystic ovary syndrome (PCOS), is a biologically heterogeneous disorder, yet previous clustering studies have reported inconsistent phenotype structures. Whether these discrepancies reflect methodological variability or genuine multidimensional disease biology remains unknown. Objective To determine whether independently derived endocrine, metabolic, inflammatory, and thyroid phenotypes represent the same underlying biological structure or capture distinct dimensions of PMOS heterogeneity. Design Cross-sectional observational study using a cross-space phenotyping framework. Setting Tertiary referral outpatient endocrinology and gynecology clinic. Participants A total of 1,286 women were diagnosed with PCOS according to the Rotterdam criteria. Methods Four predefined biological spaces (endocrine, metabolic, inflammatory, and thyroid) were analyzed independently. Within each space, standardized preprocessing, dimensionality reduction, and unsupervised clustering were performed. Cluster robustness was evaluated using bootstrap resampling, while agreement between independently derived phenotypes was quantified using the adjusted Rand index (ARI). Biological relevance was assessed using independent non-circular validation with variables excluded from phenotype derivation. Sensitivity analyses compared complete-case and imputed datasets. Results All four biological spaces produced highly stable clustering solutions (bootstrap ARI: endocrine 0.915, metabolic 0.964, inflammatory 0.930, thyroid 0.990). Despite this robustness, agreement between independently derived phenotypes remained consistently low. The highest concordance was observed between metabolic and inflammatory phenotypes (ARI = 0.208), followed by endocrine and metabolic phenotypes (ARI = 0.159), whereas agreement involving thyroid phenotypes was close to zero. Independent non-circular validation confirmed that all identified phenotypes represented biologically coherent patient subgroups beyond the variables used for clustering. Sensitivity analyses demonstrated high agreement between complete-case and imputed solutions, supporting the robustness of the findings. Conclusions Stable biological phenotypes exist within individual physiological domains of PMOS but do not converge into a single overarching biological phenotype. These findings support a multidimensional model of PMOS heterogeneity in which endocrine, metabolic, inflammatory, and thyroid systems describe complementary rather than interchangeable aspects of disease biology. Cross-space phenotyping provides a general framework for investigating biological heterogeneity in complex disorders and may facilitate future precision medicine approaches.

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New Serum Potassium Cut-Off Point for Improving Primary Aldosteronism Screening

Li, H.; Zhou, F.; Zhao, H.; Huang, W.; Wang, H.; Wang, S.

2026-07-02 endocrinology 10.64898/2026.06.30.26356983 medRxiv
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This study enrolled 152 hypertensive patients with an ARR > 3.7 to assess the relationship between the traditional hypokalemia cutoff (3.5 mmol/L) and primary aldosteronism (PA) screening, and to establish a new cutoff. Under the traditional cutoff, only 35.7% of PA patients presented with hypokalemia. ROC curve analysis identified a new cutoff of 4.22 mmol/L, which increased sensitivity from 35.7% to 77.5%, with a specificity of 91.1% and an AUC of 0.897. The findings indicate that the traditional cutoff is insufficiently sensitive, while the new cutoff markedly improves screening sensitivity and facilitates early detection of PA.

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Consequences of Early Postnatal Blockade of Aldosterone Synthesis on Behaviour and Stress Response in Male and Female Rats

Karailievova, L.; Karailiev, P.; Nagyova, A.; Jezova, D.; Hlavacova, N.

2026-07-30 physiology 10.64898/2026.07.28.741170 medRxiv
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AimThe aim of the present study was to determine whether pharmacological inhibition of aldosterone synthesis during the stress-hyporesponsive period (SHRP) affects behaviour and adrenocortical stress responsiveness later in development and whether these effects differ between males and females. MethodsNewborn Wistar rat pups (males n=40, females n=40) were treated with aldosterone synthase inhibitor FAD286 (30 mg/kg per day, orally) or vehicle from PND3 to PND9. To verify the pharmacodynamic action of FAD286, serum and adrenal glands from 10-day-old pups were analysed. The remaining pups were weaned on PND21 and underwent open-field (PND23), elevated plus-maze (PND29) and salt-preference testing. At PND46, half of each group was exposed to restraint stress for 120 min. ResultsIn 10-day-old pups, treatment with FAD286 resulted in increased gene expression of CYP11B2 (aldosterone synthase) and CYP11B1 (11-beta-hydroxylase) in the adrenal glands, increased serum levels of corticosterone, and decreased concentrations of serum aldosterone. FAD286 did not modify the general locomotor activity assessed in juvenile rats. Inhibition of aldosterone synthase by FAD286 resulted in altered anxiety-like behaviour in a sex-dependent manner. Postnatal FAD286 treatment led to increased anxiety-like behaviour in female, but not male rats. During adolescence, early FAD286 treatment increased overall aldosterone concentrations without altering the aldosterone response to restraint. Basal corticosterone concentrations were unchanged, whereas the response to restraint was enhanced. ConclusionsThe present study demonstrates that transient inhibition of aldosterone synthesis during the SHRP led to alterations in anxiety-related behaviour and adrenocortical regulation later in development, with some behavioural effects being sex-dependent.