Hormone Synthesis Research Articles

Gender-Specific DNA Methylation Profiles Associated with Adult Weight in Hezuo Pigs

The Hezuo pig, an important native Tibetan breed in China, exhibits differences in adult body weight, with females typically heavier than males. The underlying mechanisms for this disparity remain unclear. DNA methylation changes are known to influence animal growth and development and regulate Hezuo pig growth by altering gene expression related to these processes, thus differentially affecting adult body weight between genders. This study conducted DNA methylation analysis and expression profiling using pituitary tissues from male and female Hezuo pigs at 3 and 8 months old (M3M, M3F, M8M, and M8F). In total 346, 795, 371, and 839 differentially methylated genes (DMGs) were identified in the M3M vs. M3F, M3F vs. M8F, M3M vs. M8M, and M8M vs. M8F groups, respectively. The comparative analysis of differentially methylated regions (DMRs) genes and DEGs (differentially expressed regions) revealed that key genes involved in growth, hormone secretion, and the hypothalamic-pituitary-gonadal axis are primarily enriched in signaling pathways such as PI3K-Akt, Hippo, and adrenergic. Further analysis combining methylation and transcriptomics identified five candidate methylated genes (CCL2, MYL2, GST, CTSH, and MCH) linked to adult body weight in Hezuo pigs. Additionally, the correlation analysis suggested that these genes influence growth and development in boars and sows by regulating the secretion and synthesis of related hormones, leading to heavier weights in females. In conclusion, variations in adult body weight between male and female pigs may stem from the impact of DNA methylation on gene expression related to growth and development. These findings offer new insights into the regulatory mechanisms of DNA methylation during weight gain in Hezuo pigs.

Growth hormone-releasing hormone and cancer.

The hypothalamic hormone growth hormone-releasing hormone (GHRH), in addition to promoting the synthesis and release of growth hormone (GH), stimulates the proliferation of human normal and malignant cells by binding to GHRH-receptor (GHRH-R) and its main splice variant, SV1. Both GHRH and GHRH-Rs are expressed in various cancers, forming a stimulatory pathway for cancer cell growth; additionally, SV1 possesses ligand independent proliferative effects. Therefore, targeting GHRH-Rs pharmacologically has been proposed for the treatment of cancer. Various classes of synthetic GHRH antagonists have been developed, endowed with strong anticancer activity in vitro and in vivo, in addition to displaying anti-inflammatory, antioxidant and immune-modulatory functions. GHRH antagonists exert indirect effects by blocking the pituitary GH/hepatic insulin-like growth factor I (IGF-I) axis, or directly inhibiting the binding of GHRH on tumor GHRH-Rs. Additionally, GHRH antagonists block the mitogenic functions of SV1 in tumor cells. This review illustrates the main findings on the antitumor effects of GHRH antagonists in experimental human cancers, along with their underlying mechanisms. The development of GHRH antagonists, with reduced toxicity and high stability, could lead to novel therapeutic agents for the treatment of cancer and inflammatory diseases.

Widespread production of plant growth-promoting hormones among marine bacteria and their impacts on the growth of a marine diatom

BackgroundReciprocal exchanges of metabolites between phytoplankton and bacteria influence the fitness of these microorganisms which ultimately shapes the productivity of marine ecosystems. Recent evidence suggests that plant growth-promoting hormones may be key metabolites within mutualistic phytoplankton-bacteria partnerships, but very little is known about the diversity of plant growth-promoting hormones produced by marine bacteria and their specific effects on phytoplankton growth. Here, we aimed to investigate the capacity of marine bacteria to produce 7 plant growth-promoting hormones and the effects of these hormones on Actinocyclus sp. growth.ResultsWe examined the plant growth-promoting hormone synthesis capabilities of 14 bacterial strains that enhance the growth of the common diatom Actinocyclus. Plant growth-promoting hormone biosynthesis was ubiquitous among the bacteria tested. Indeed all 14 strains displayed the genomic potential to synthesise multiple hormones, and mass-spectrometry confirmed that each strain produced at least 6 out of the 7 tested plant growth-promoting hormones. Some of the plant growth-promoting hormones identified here, such as brassinolide and trans-zeatin, have never been reported in marine microorganisms. Importantly, all strains produced the hormone indole-3 acetic acid (IAA) in high concentrations and released it into their surroundings. Furthermore, indole-3 acetic acid extracellular concentrations were positively correlated with the ability of each strain to promote Actinocyclus growth. When inoculated with axenic Actinocyclus cultures, only indole-3 acetic acid and gibberellic acid enhanced the growth of the diatom, with cultures exposed to indole-3 acetic acid exhibiting a two-fold increase in cell numbers.ConclusionOur results reveal that marine bacteria produce a much broader range of plant growth-promoting hormones than previously suspected and that some of these compounds enhance the growth of a marine diatom. These findings suggest plant growth-promoting hormones play a large role in microbial communication and broaden our knowledge of their fuctions in the marine environment.4YJWCKdNErspcm2bUDNM6tVideo

Perfluorooctane sulfonate (PFOS) and benzo[a]pyrene (BaP) synergistically induce neurotoxicity in C6 rat glioma cells via the activation of neurotransmitter and Cyp1a1-mediated steroid hormone synthesis pathways

Humans are often exposed to complex mixtures of multiple pollutants rather than a single pollutant. However, the combined toxic effects and the molecular mechanism of PFOS and BaP remain poorly understood. In this study, two typical environmental pollutants, perfluorooctane sulfonate acid (PFOS) and benzo[a]pyrene (BaP), were selected to investigate their combined neurotoxic effects on rat C6 glioma cells at environmentally relevant concentrations. The results showed that coexposure to low-dose PFOS and BaP induced greater toxicity (synergistic effect) than did single exposure. PFOS-BaP coexposure had stronger toxic effects on inducing oxidative stress and promoting early apoptosis. Targeted metabolomics confirmed that increased levels of the neurotransmitters 5-hydroxytryptophan, dopamine, tryptophan and serotonin disturb the phenylalanine, tyrosine and tryptophan biosynthesis pathways. Mechanistically, exposure to a low-dose PFOS-BaP binary mixture induces steroid hormone synthesis disorder through the activation of Cyp1a1 and Hsd17b8 (steroid hormone synthesis genes) and Dhcr24 and Dhcr7 (cholesterol synthesis genes). These findings are useful for comprehensively and systematically elucidating the biological safety of PFOS-BaP and its potential threats to human health.

Assessing Alcohol Genes Targets in Mouse Liver

Background: Alcohol is a risk factor for liver diseases. There is a correlation between alcohol consumption and fatty liver disease. Experiences have shown gene expression alteration in the liver following alcohol consumption. Since the molecular mechanism of connection between alcohol consumption and fatty liver disease needs a clear perspective, this study aims to explore the significant genes that are targeted by alcohol in the liver of mice.Methods: Gene expression profiles of mice livers fed with alcohol were retrieved from the Gene Expression Omnibus (GEO) database and compared with the control samples. Data are pre-evaluated with the GEO2R program, and the significant differentially expressed genes (DEGs) are analyzed via gene expression evaluations and regulatory network assessment. Results: Among the 25619 dysregulated genes, 78 significant DEGs were pointed out. Gene expression analysis showed that most extremely dysregulated genes are up-regulated and belong to the cytochrome P450 genes family. Finally, cytochrome P450 and glutathione S-transferase genes family, as well as hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerase 4, were introduced as the critical targeted genes.Conclusion: In conclusion, detoxification of xenobiotics, cellular metabolism and homeostasis, the pathogenesis of some liver diseases, synthesis of several prostaglandins and steroid hormones, and inflammation fibrosis in the liver are possibly associated with alcohol consumption.

Mating behaviour and cholesterol nutritional strategies promoted ovarian development of female swimming crab (Portunus trituberculatus).

Female crabs enter a stage of rapid ovarian development after mating, and cholesterol is a substrate for steroid hormone synthesis. Therefore, in this experiment, an 8-week feeding trial was conducted to investigate the effects of mating treatments (mated crab and unmated crab) and three dietary cholesterol levels (0·09 %, 0·79 % and 1·40 %) on ovarian development, cholesterol metabolism and steroid hormones metabolism of adult female swimming crab (Portunus trituberculatus). The results indicated that crabs fed the diet with 0·79 % cholesterol significantly increased gonadosomatic index (GSI) and vitellogenin (VTG) content than other treatments in the same mating status. Moreover, mated crabs had markedly increased GSI and VTG content in the ovary and hepatopancreas than unmated crabs. The histological observation found that exogenous vitellogenic oocytes appeared in the mated crabs, while previtellogenic oocytes and endogenous vitellogenic oocytes were the primary oocytes in unmated crabs. The transmission electron microscopy analysis showed that when fed diet with 0·79 % cholesterol, the unmated crabs contained more rough endoplasmic reticulum and mated crabs had higher yolk content than other treatments. Furthermore, mating treatment and dietary 0·79 % cholesterol level both promoted cholesterol deposition by up-regulation of the mRNA and protein expression levels of class B scavenger receptors 1 (Srb1), while stimulating the secretion of steroid hormones by up-regulation of the mRNA and protein expression of steroidogenic acute regulatory protein (Star). Overall, the present results indicated that mating behaviour plays a leading role in promoting ovarian development, and dietary 0·79 % cholesterol level can further promote ovarian development after mating.

Interactions of Polychlorinated Biphenyls and Their Metabolites with the Brain and Liver Transcriptome of Female Mice.

Exposure to polychlorinated biphenyls (PCBs) is linked to neurotoxic effects. This study aims to close knowledge gaps regarding the specific modes of action of PCBs in female C57BL/6J mice (>6 weeks) orally exposed for 7 weeks to a human-relevant PCB mixture (MARBLES mix) at 0, 0.1, 1, and 6 mg/kg body weight/day. PCB and hydroxylated PCB (OH-PCBs) levels were quantified in the brain, liver, and serum; RNA sequencing was performed in the striatum, prefrontal cortex, and liver, and metabolomic analyses were performed in the striatum. Profiles of PCBs but not their hydroxylated metabolites were similar in all tissues. In the prefrontal cortex, PCB exposure activated the oxidative phosphorylation respiration pathways, while suppressing the axon guidance pathway. PCB exposure significantly changed the expression of genes associated with neurodevelopmental and neurodegenerative diseases in the striatum, impacting pathways like growth hormone synthesis and dendrite development. PCBs did not affect the striatal metabolome. In contrast to the liver, which showed activation of metabolic processes following PCB exposure and the induction of cytochrome P450 enzymes, the expression of xenobiotic processing genes was not altered by PCB exposure in either brain region. Network analysis revealed complex interactions between individual PCBs (e.g., PCB28 [2,4,4'-trichlorobiphenyl]) and their hydroxylated metabolites and specific differentially expressed genes (DEGs), underscoring the need to characterize the association between specific PCBs and DEGs. These findings enhance the understanding of PCB neurotoxic mechanisms and their potential implications for human health.

Pregnancy-related hormonal changes and thyroid growth: do they have an impact on the higher incidence of differentiated thyroid cancer in women?

To analyze whether pregnancy could play a role in the higher prevalence of differentiated thyroid carcinoma (DTC) in women. Estrogens strongly modify thyroid economy by increasing iodine clearance, thyroid hormone requirement and production. Human chorionic gonadotropin (hCG) contributes to the increased thyroid hormone synthesis. Both estrogens and hCG can interfere with the regulation of thyroid volume and with thyroid nodule development and progression. The potential effect of hCG is exclusively related to its weak agonistic activity on TSH receptor. Estrogen implication on normal and nodule-derived thyrocyte growth has been demonstrated in vitro and in animal models. Furthermore, there is solid clinical evidence showing a promoting effect of pregnancy on thyroid volume and nodule development. Two metanalysis, one including retrospective and another prospective observational studies, failed to show an association between pregnancy and DTC. A large pooled prospective analysis using multivariable-adjusted Cox proportional hazard models did not demonstrate an association between DTC and parity. Similarly, no association between PTC occurrence and parity was observed in a prospective cohort analysis by linkage to the statewide Surveillance, Epidemiology, and End Results (SEER). The presently available evidence does not support an involvement of pregnancy in DTC etiology.

Evaluation of alpha Klotho and fibroblast growth factor-23 levels in Iraqi patients with Graves’ disease

Background & Objective: Graves’ disease (GD) is an autoimmune condition that targets the thyroid gland, resulting in excessive stimulation and synthesis of thyroid hormones. Excessive synthesis of these hormones can lead to symptoms such as loss of body weight, accelerated heart rate, irritability, reduced tolerance to heat, and excessive perspiration. Alpha-Klotho (KL), a protein crucial for physiological processes, is also involved in GD. The defective immunological condition of GD patients may increase Klotho expression, and the enhanced expression of fibroblast growth factor-23 (FGF23) in GD may be linked to the disease pathophysiology. We investigated serum levels of KL and FGF23 in Iraqi patients with Graves’ disease, analyzing correlations with clinical status and evaluating their potential as biomarkers for disease activity. Methodology: We conducted this cross-sectional study at The National Diabetes Center, Mustansiriyah University, between December 2022 and April 2023. The study involved 103 patients diagnosed with GD, and 103 patients, aged 21-70 y, as a control group. Patients with multinodular goiter, single thyroid nodules, thyroiditis, pregnant women, and those on medications or oral contraceptives, were excluded. Result: clinical significance of FGF23 and Klotho (KL) levels in patients with Graves’ disease (GD) compared to a control group. Results indicate that the median of KL levels are significantly higher in GD patients (KL = 6.31) compared to the control group (KL = 2.40), with a highly significant difference (P < 0.001). In contrast, differences in median of FGF23 levels between GD patients (149) and controls (86.05) were not statistically significant (P = 0.07). Furthermore, KL levels were significantly higher in hyperthyroid patients compared to other thyroid statuses (P = 0.023), while FGF23 levels did not significantly differ across thyroid statuses (P = 0.255). Additionally, the study found a strong correlation between TRAb levels and both KL (r = 0.291, P < 0.001) and FGF23 (r = 0.211, P = 0.003), and between KL and FGF23 directly (r = 0.412, P < 0.001). These findings suggest that while KL may be a significant biomarker in GD, FGF23 relevance appears limited in this context. Conclusion: In Graves’ Disease patients have significantly higher levels of KL and FGF23 compared to controls, suggesting a distinct pathophysiological role for these biomarkers in mineral homeostasis and thyroid hormone regulation. Abbreviations: AITD - Autoimmune thyroid diseases; KL - Alpha-Klotho; FGF23 - fibroblast growth factor-23; GD - Graves’ disease; HT - Hashimoto's thyroiditis; IGF-1R - Insulin-like Growth Factor-1 Receptor; Keywords: Autoimmune Thyroid Disorders, Hyperthyroidism, Graves’ disease, Alpha-Klotho Citation: Rashid MF, Alammar HAJ, Rahmah AM. Evaluation of alpha Klotho and fibroblast growth factor-23 levels in Iraqi patients with Graves’ disease. Anaesth. pain intensive care 2024;28(5):836−841. DOI: 10.35975/apic.v28i5.2567 Received: June 16, 2024; Reviewed: July 07, 2024; Accepted: July 18, 2024

Role of Gonadal Steroid Hormones in the Eye: Therapeutic Implications.

Gonadal steroid hormones are critical regulatory substances involved in various developmental and physiological processes from fetal development through adulthood. These hormones, derived from cholesterol, are synthesized primarily by the gonads, adrenal cortex, and placenta. The synthesis of these hormones involves a series of enzymatic steps starting in the mitochondria and includes enzymes such as cytochrome P450 and aromatase. Beyond their genomic actions, which involve altering gene transcription over hours, gonadal steroids also exhibit rapid, nongenomic effects through receptors located on the cell membrane. Additionally, recent research has highlighted the role of these hormones in the central nervous system (CNS). However, the interactions between gonadal steroid hormones and the retina have received limited attention, though it has been suggested that they may play a protective role in retinal diseases. This review explores the synthesis of gonadal hormones, their mechanisms of action, and their potential implications in various retinal and optic nerve diseases, such as glaucoma, age-related macular degeneration (AMD), diabetic retinopathy (DR), or retinitis pigmentosa (RP), discussing both protective and risk factors associated with hormone levels and their therapeutic potential.

Analysis of the plant hormone expression profile during somatic embryogenesis induction in teak (Tectona grandis).

Plant somatic embryogenesis (SE) is an efficient regeneration system for propagation. It involves the regulation of a complex molecular regulatory network encompassing endogenous hormone synthesis, metabolism, and signal transduction processes, induced through exogenous plant growth regulators. Previous studies have focused primarily on traditional propagation methods for Tectona grandis, but there is limited knowledge on SE and its hormonal regulatory mechanisms. In our study, different SE stages, including the nonembryogenic callus (NEC), embryogenic callus (EC), and globular and heart-shaped embryo (E-SEs) stages, were induced in teak cotyledons incubated on MS medium supplemented with 0.1 mg/L thidiazuron (TDZ). Morphological and histological observations indicated that EC primarily originates from the development of embryogenic cell clusters. During SE induction, the levels of six classes of endogenous hormones, IAA, CTK, ETH, ABA, SA, and JA, changed significantly. Transcriptome analysis revealed that endogenous hormones participate in SE induction in teak through various biological processes, such as biosynthesis, metabolism, and signal transduction pathways. We found that IAA biosynthesis primarily occurs through the IAM pathway during these three stages. The ETH receptor kinase gene SERF1 exhibited the highest expression levels in E-SEs. The ABA-, SA-, and JA-related signal transduction genes ABI3, NPR1, and JAZ exhibited no differential expression during different stages. Moreover, key encoding genes of SE regulators, including WUS, WOX and SERK, were differentially expressed during SE. In conclusion, this study offers insights into the roles of endogenous hormones and their interactions during SE induction.

Hormonal signaling regulates photosynthetic function of alfalfa (Medicago sativa L.) under NaHCO3 stress

The physiological and molecular mechanisms underlying salt-alkali tolerance in Medicago sativa are of significant importance for the development of animal husbandry on salt-alkali lands and the restoration of vegetation in such areas. This study utilized salt-alkali tolerance Medicago sativa 'Zhaodong' (ZD) and salt-alkali sensitive variety M. sativa 'Zhongmu No.1′ (ZM) as materials. Physiological analyses, transcriptomic sequencing, and hormone-targeted metabolomics techniques were employed to investigate the differential responses of the two alfalfa varieties to NaHCO3 stress in terms of morphology, photosynthetic functionality, and oxidative damage indicators. Additionally, weighted gene co-expression network analysis (WGCNA) was utilized to elucidate key mechanisms underlying salt-alkali tolerance in alfalfa. The results indicate that NaHCO3 stress leads to photosynthetic inhibition and oxidative damage in alfalfa leaves. Under NaHCO3 stress, PSI in alfalfa leaves exhibits higher stability compared to PSII. The salt-alkali tolerance alfalfa variety ZD demonstrates stronger tolerance compared to the salt-alkali sensitive variety ZM. Furthermore, differentially expressed genes (DEGs) between the two varieties under NaHCO3 stress are primarily enriched in KEGG pathways such as chlorophyll synthesis, photosynthesis, carbon fixation, and plant hormone synthesis and signaling. Weighted gene co-expression network analysis (WGCNA) was conducted based on physiological and transcriptomic data. Most differentially expressed genes (DEGs) in the top two modules with the highest correlation to physiological indicators such as photosynthesis are enriched in hormone synthesis and signal transduction pathways. Additionally, key transcription factors involved in hormone signal transduction were identified within these modules, such as MYC2 and ABI5, which regulate jasmonic acid (JA) and abscisic acid (ABA) signaling, respectively. These findings suggest that plant hormone signaling may play a critical role in regulating salt-alkali tolerance in alfalfa. Further analysis was conducted on plant hormone levels and gene expression involved in biosynthesis and signal transduction processes. The results indicate that NaHCO3 stress leads to significant accumulation of ABA and JA content in alfalfa leaves. The biosynthesis and signal transduction pathways of ABA and JA are activated under NaHCO3 stress. Additionally, the salt-alkali tolerance alfalfa variety ZD exhibits a more sensitive response to ABA and JA signals compared to ZM. Salicylic acid (SA) shows a positive response to NaHCO3 stress only in the ZD variety, which may be one of the key reasons for its stronger salt-alkali tolerance. Under NaHCO3 stress, overall growth-promoting hormones (IAA, GA, CK) are downregulated in ZD but upregulated in ZM, indicating that the salt-alkali tolerance alfalfa variety ZD mainly regulates the balance between growth and resistance by modulating the ratio of growth-promoting and stress-related hormones in response to NaHCO3 stress. This study reveals that hormone signaling plays a key role in regulating the photosynthetic function of alfalfa in response to salt-alkali stress, which provides theoretical basis and clues for the molecular breeding of alfalfa for salt-alkali tolerance.

8751 Radiofrequency Thermal Ablation in 32 Patients with Toxic Adenomas with Resolution of Hyperthyroidism in All Cases

Abstract Disclosure: L.G. Amato: None. E.M. Volpi: None. L.D. Volpi: None. P.M. Carani: None. A. Rahal: None. Introduction: In the general population, thyroid nodules are found in 3-7% of individuals on physical examination and in 20-76% on ultrasound. Around 8-10% of benign nodules may present autonomous behavior, being called hot nodules, causing symptoms of hyperthyroidism and being called toxic adenomas (TA). In TAs, autonomous hormone production can be caused by somatic activating mutations of genes regulating thyroid growth and hormone synthesis caused by somatic activating mutations of genes regulating thyroid growth and hormone synthesis. Classically, the proposed treatment for autonomous nodules was surgical resection or radioiodine ablation (RAI). In this context, the prevalence of hypothyroidism after the procedure varies from 2% to 3% following lobectomy, and lower after isthmusectomy in the unique circumstance in which the TA is confined to the thyroid isthmus. A study following 684 patients with TA treated with RAI reported a progressive increase in overt and sub-clinical hypothyroidism. Potential complications following near-total/total thyroidectomy include the risk of permanent hypoparathyroidism (< 2.0%) or recurrent laryngeal nerve injury (RLN) (< 2.0%). A small risk of permanent RLN injury exists with surgery for TA. Following RAI therapy, there have been reports of new-onset Graves Disease (up to 4% prevalence) as well as concern for thyroid malignancy and a very minimal increase in late non thyroid malignancy. Radiofrequency ablation (RFA) has been a precise and effective alternative for the treatment of many benign thyroid nodules over the past ten years, including hot nodules. RFA could preserves normal thyroid function compared to surgery or RAI. Clinical case: We evaluated the effectiveness of a single session of RFA in 32 patients with TA, through hormonal status, achieving normalization of thyroid and volumetric reduction of the nodule. Among the 32 patients included in this study, aged between 25 and 88 years, of these, 31 were women and 1 was a man, all of whom underwent a single RFA procedure (“moving shot” technique associated with hydrodissection). We had a single case of a reversible complication: a patient who had transient vocal cord paralysis, with total reversal. There was a reduction in the volume of all nodules as well as all patients progressed to a state of euthyroidism within 60 days of follow-up. Conclusion: A single session of RFA was effective in treating autonomous nodules, restoring euthyroidism in all patients. Presentation: 6/3/2024

8698 Unique populations of pituitary macrophages regulate gonadotropin secretion

Abstract Disclosure: Z. Del Mundo: None. J. Ha: None. A. Zhang: None. K.D. Wiggins: None. G. De Robles: None. C. Garcia: None. N. Ujagar: None. D. Nicholas: None. Chronic inflammation disrupts hormonal balance in the Hypothalamic-Pituitary-Gonadal (HPG) axis, contributing to reproductive disorders. Despite extensive studies on immune cells in the hypothalamus and ovaries, their impact on the pituitary is largely unexplored. Our research reveals that macrophages are the primary immune population in the pituitary during homeostasis. In response to in vivo chronic lipopolysaccharide exposure in mice, a transient macrophage population emerges, associated with reproductive changes, including elevated serum testosterone, prolonged estrous cycle stage, and reduced ovarian antral follicle count. This study aims to characterize pituitary macrophages and elucidate their impact on the HPG axis. We hypothesize that pituitary macrophages change inflammatory status as a response to stimuli and, as a result, modulate gonadotropin secretion. We pinpointed differentially expressed genes (DEGs) in pituitary macrophages using scRNAseq, distinguishing them from other tissue-resident macrophages, including microglia. These DEGs include markers for macrophage activation, phagocytosis, migration, hormone synthesis, and lipid metabolism. Immunohistochemistry validated the distinctive morphology of pituitary macrophages compared to microglia. In vitro depletion of macrophages from mouse pituitaries resulted in decreased pituitary hormone secretion and decreased secretion of G-CSF, IL-9, and CXCL5. These results highlight the role of pituitary macrophages in hormonal regulation, setting the stage for future immunotherapeutic strategies to restore hormonal balance in reproductive disorders. Presentation: 6/3/2024

8454 Iron deficiency as a cause of euthyroid syndrome

Abstract Disclosure: O.V. Samburskaya: None. S. Kalinchenko: None. L. Vorslov: None. Annotation: The prevalence of euthyroid pathology syndrome is increasing, and the cause of its occurrence remains unknown, despite the decrease in the quality of life of these patients, there is no treatment for this pathology. One of the reasons may be iron deficiency, which not only reduces the activity of thyroid enzymes, but also disrupts the feedback between a decrease in triiodothyronine and the level of thyroid-stimulating hormone (TSH). Materials and methods: There are 6 patients under observation, aged from 25 to 55 years, average age 38.4±12.67 years, gender distribution: 4 women 67% and 2 men 33%, who are undergoing treatment to compensate for iron deficiency and simultaneously control thyroid function. The analysis of iron deficiency is performed according to blood test parameters: total blood count, total serum iron binding capacity, transferrin, ferritin, serum iron. The function of the thyroid gland is determined by blood test parameters: T4 free, T3 free, TSH.The received data. According to the results of the data obtained, latent iron deficiency was found in all 6 patients. All patients have a decrease in thyroid hormone levels: T3 free 3.87±0.45 pmol/l (reference range 3.69-8.46 pmol/L) and T4 free 14.17±1.23 pmol/L (reference range 12.3-22.8 pmol/L) is closer to the lower limit of normal, but TSH is also closer to the lower limit of the norm is 1.46±0.33 µm/ml (reference range 0.70-5.9 µm/ml). Discussion: The existing iron deficiency leads to the development of chronic hypoxia, which leads to a violation of the functioning of many endocrine glands, including a violation of the work of thyroid enzymes: thyroid peroxidase and deiodinases, with a decrease in the synthesis of thyroid hormones (T4 and T3), and according to the feedback principle, an decrease in the level of thyroxine and triiodothyronine is expected raising the level of TSH. However, with chronic hypoxia, iron deficiency, hypoxic dysfunction develops not only of the peripheral endocrine glands, but also hypoxic hypothalamic-pituitary dysfunction, which leads to an inadequate response of the pituitary gland, i.e. the absence of an increase in TSH in response to a decrease in thyroid hormones. Conclusion: All patients with euthyroid syndrome need to evaluate the biochemical parameters of the body's iron supply, and the elimination of deficiency of which may be the necessary treatment for patients with euthyroid pathology. Presentation: 6/2/2024

6537 Recurrent Graves Thyrotoxicosis After Prolonged Radioiodine-Induced Hypothyroidism

Abstract Disclosure: H.K. Deveaux: None. A. Gundeti: None. K. Mitrollari: None. A.P. Calimag: None. T. Yasmeen: None. Radioactive iodine (I-131) ablation (RAI) is one of the effective therapies for Graves’ disease (GD). Successful treatment is indicated by sustained, irreversible hypothyroidism requiring lifelong replacement for which recurrence of disease rarely develops. Recurrent hyperthyroidism is a rare development without apparent predisposition. Here, we describe a case of recurrent thyrotoxicosis after 36 years of RAI.70-year-old female PMH atrial fibrillation (AFib) on apixaban s/p cardioversion, HTN, HFpEF, Pulmonary HTN, and Graves’ Disease s/p RAI ablation 36 years ago with RAI-induced hypothyroidism. The patient was initially on levothyroxine for post-ablative hypothyroidism and stopped taking levothyroxine around 2019. NM scintigraphy done in 2019 showed an abnormal I-123 thyroid uptake and scan with the five-hour radioiodine thyroid uptake showed mildly hyperthyroid. On the thyroid scan, there is a note of a prominent pyramidal lobe with some thyroid gland asymmetry. In 2022, the patient was admitted for new-onset AFib and was noted to have subclinical hyperthyroidism with TSH 0.157, fT4 1.4, TrAb>40, and TSI 34.8. The patient was started on methimazole, which she stopped one month later. During this admission, the patient presented secondary to a mechanical fall and was found to be in AFib with a rapid ventricular rate. Her labs were significant for TSH<0.008 fT4 4.2, TrAb >40. Methimazole was restarted with maximal doses of diltiazem and metoprolol for rate control. Thyroid ultrasound demonstrated an enlarged, heterogeneous thyroid gland with increased vascularity and multiple bilateral TR3 thyroid nodules.Hyperthyroidism affects approximately 1.2% of the population. GD involves autoantibodies activating the thyrotropin receptor, increasing synthesis and release of thyroid hormone and is for 50-60% of cases with a 5-to-10-fold preference for females. RAI ablation is preferred, being inexpensive, with a cure rate approaching 100%. The incidence of transient hypothyroidism post-RAI varies from 9-17%. Retrospective studies have observed hyperthyroidism within the first 12 months post-RAI; however, some cases have seen a resurgence as late as 22 years later. Recurrent hyperthyroidism is an uncommon occurrence with various postulated aetiologies, such as inadequate dosing/incomplete ablation with residual cells remaining viable and regenerating in the setting of increased TSIiv, Marine-Lenhart syndrome (MLS), or an unclear mechanism associated with autoimmunity in the presence of TSI. Hyperthyroidism rarely recurs in GD after successful post-ablative treatment with RAI. Our case, while an uncommon presentation and underlying aetiology yet to be determined, illustrates the importance of continued surveillance, even after successful treatment.‌ Presentation: 6/3/2024

6770 Graves’ disease induced by COVID-19 infection in a 49 year old male

Abstract Disclosure: N. Al-hosainat: None. A. Al Najada: None. T. Salar: None. S. Iqbal: None. K. Abdel Gadir: None. Introduction: Graves’ disease is an autoimmune disease causing hyperthyroidism, characterized by elevated thyrotropin-receptor antibodies. COVID-19 infection has been increasingly reported as a trigger of thyroid illness including Graves’ disease. We present a unique case of 49-year-old patient who was diagnosed with Graves’ disease after COVID-19 infection. Case description: A 49-year-old male patient with history of prediabetes presented with complaints of tremor, fatigue, generalized itching, and unintentional weight loss (30 Ibs in 6 months). He had COVID-19 infection 3 months prior. The remainder of review of systems was negative. No family history of thyroid disease. On exam, the patient had sinus tachycardia with otherwise normal vital signs. Diffuse thyromegaly was noted along with an intermittent fine tremor of the extremities. Blood work was notable for low TSH <0.01 uIU/mL, elevated free T4 (3.4 ng/dL), free T3 (17.6ng/dL), and TSH receptor antibody (12 IU/L). Thyroid ultrasound showed mild goiter with 2 nodules, one of which was TIRADS 4 and 1.5cm. This nodule was biopsied and found to be benign. Radioactive iodine uptake scan revealed homogeneous diffuse increased thyroid uptake. The diagnosis of Graves’ disease was made, and the patient was started on propranolol and methimazole with significant improvement of his symptoms and his laboratory tests normalizing. Discussion: Graves' disease is an autoimmune disease, characterized by hyperthyroidism, goiter, occasional orbitopathy and dermopathy. Caused by antibodies against thyroid-stimulating hormone receptors which stimulate thyroid hormone secretion and thyroid growth. Treatment is aimed to decrease thyroid hormone synthesis by either a Thionamide, radioiodine ablation, or surgery. Remission rates with antithyroid drugs average under 40 percent after one to two years of treatment and could exceed 80 percent after 5 to 10 years of treatment. COVID-19 is a multi-system disease, caused by SARS-CoV-2 virus, transmitted by large droplets and small particle aerosols, was declared a pandemic in 2020 and affected millions of people worldwide. There is emerging data showing the association of COVID-19 with various thyroid diseases including thyroiditis and relapse of known Graves' disease after the infection. We present a case of newly diagnosed Graves’ disease after COVID-19 infection in a patient with no personal or family history of such disease which raises the concern of autoimmune pathway activation induced by the infection. The onset of Graves’ disease after COVID-19 infection does not depend on the presence of pre-existing thyroid pathology and in this case responded well to antithyroid medication. Conclusion: COVID-19 can lead to the development of a range of medical illnesses. In patients who develop symptoms of thyrotoxicosis, Graves’ disease should be suspected, investigated, and treated appropriately Presentation: 6/3/2024

7099 Severe Hypothyroidism from Potassium Iodide Supplements: A Case of Failure to Escape from Wolf- Chaikoff Effect

Abstract Disclosure: M.G. Hamilton: None. A. Kulkarni: None. P. Lekprasert: None. Introduction: The Wolf-Chaikoff effect (WCE) is a physiological response of the thyroid gland to supraphysiologic iodide levels. Failure to escape the WCE can lead to thyroid dysfunction, and we present such a case in a patient with Hashimoto’s thyroiditis taking high-dose potassium iodide (KI). Case Description: A 44-year-old female with hypothyroidism secondary to Hashimoto’s thyroiditis presented with 10-pound weight gain, extremity swelling, fatigue, and abnormal menstruation. She was prescribed Levothyroxine several years ago but stopped taking it shortly after as she felt no improvement. On physical exam, she was bradycardic with heart rate of 58 bpm. There is no goiter but dry skin and edematous lower extremities. Labs revealed TSH of 127 pg/mL (0.35-4.94), free T4 0.1ng/dL (0.8-1.8), TPO Ab 645 (<9) IU/mL in comparison to her labs 2 months ago of TSH 11 pg/mL and free T4 0.9 ng/dL. Suspicion for worsening hypothyroidism from Hashimoto’s was low given this dramatic change on labwork and clinically. On further questioning, she had been taking KI 130 mg/day (Iodine 100 mg, daily requirement 150 mcg/day) as advised by her homeopathic doctor. The supplements were stopped, and she was re-started on Levothyroxine. After 8 weeks, she reported improvement of symptoms and weight loss. TSH is normal at 3.54pg/ml and free T4 1.2 ng/dL. Discussion:The WCE serves as a protective mechanism to decrease thyroid hormone production in the setting of high iodide levels to prevent development of hyperthyroidism. WCE is explained by the formation of Iodopeptides inhibits thyroid peroxidase (TPO) mRNA and protein synthesis resulting in an inhibition of thyroglobulin iodination. WCE is temporary and expected to wane over a few days to weeks and is known as the Wolf-Chaikoff escape due to down regulation of the sodium iodine symporter (NIS) thereby decreasing the intrathyroidal inorganic iodine concentration and permitting normal TPO activity. Rarely, failure to escape WCE can lead to hypothyroidism due to continued suppression of thyroid hormone synthesis. Risk factors include underlying thyroid diseases i.e. Hashimoto’s or other causes of thyroiditis, use of Amiodarone, Lithium or Iodine-containing radiocontrast media and KI supplements. In our case, Hashimotos’ thyroiditis predisposed her to thyroid dysfunction and failure to escape from WCE after taking high-dose KI supplements causing severe hypothyroidism. Thus, this report highlights that in clinical practice, especially in patients with pre-existing thyroid dysfunction, a significant TSH increase, a high suspicion index is needed to investigate for other causes like concurrent use of iodine-containing food/drug leading to the failed escape from WCE apart from verifying compliance to thyroid replacement therapy. Presentation: 6/3/2024

8603 Sex Steroids Have Opposing Impacts on Female Gonadotrope Metabolism and LH Secretion via GLUT1

Abstract Disclosure: C. Garcia: None. C. Nguyen: None. S. Wang: None. D. Trinh: None. U. Le: None. R. Kapadia: None. J. De La Torre: None. C.K. De La Cruz: None. D. Nicholas: None. Gonadotropes of the anterior pituitary regulate reproductive hormone synthesis and secretion not only through GnRH signaling from the hypothalamus, but by also determining if glucose availability, via GLUT1, meets the current requirements to support reproduction. GLUT1 facilitates glucose uptake and in gonadotropes its expression increases during the LH surge which indicates its necessity in the maximal secretion of LH through glycolysis. However, the mechanisms underlying the feedback from sex steroids that also mediate female reproduction have not been completely elucidated. By manipulating GLUT1 expression and sex steroid levels using cell lines and a conditional knockout of GLUT1 in mouse gonadotrope we show that sex steroids alter GLUT1 expression and translocation effecting gonadotrope glycolysis and subsequent gonadotropin secretion. Tamoxifen treated iGricCre +/+ GLUT1 fl/fl mice display disrupted estrous cycles and changes in serum gonadotropins. Dihydrotestosterone (DHT) or estradiol (E2) replacement in gonadectomized male and female, respectively, surprisingly result in increased (by DHT) or reduced (by E2) pituitary GLUT1 protein as measured by western blot despite both inhibiting serum LH. Using extracellular flux analysis and imaging flow cytometry, we show that LβT2 cells treated with DHT increase while E2 decreases glycolysis and translocation of GLUT1 to the cellular surface. We conclude that sex steroids regulate gonadotropin secretion and reproduction through direct impacts on gonadotrope metabolism through GLUT1. Presentation: 6/1/2024

7912 Children's Neurodevelopmental Outcomes at School-Age After Conception with Hysterosalpingography Using Iodinated Contrast Media

Abstract Disclosure: S. Keestra: None. C. Kooper: None. N. van Welie: None. K. Dreyer: Grant Recipient; Self; research grants from Guerbet. Speaker; Self; travel and speaker fees Guerbet. R. van Eekelen: None. T. Roseboom: None. J. Oosterlaan: None. B. Mol: Consulting Fee; Self; Organon Laboratories, Norgine, Merck. Grant Recipient; Self; Merck. Stock Owner; Self; ObsEva. M. Finken: None. V. Mijatovic: Grant Recipient; Self; Guerbet, Merck, Ferring Pharmaceuticals. Speaker; Self; Guerbet, Merck, Ferring Pharmaceuticals. M. Königs: None. Thyroid hormone sufficiency in pregnancy is vital for children's neurodevelopment. Exposure to iodine excess can cause transient disruption of thyroid hormone synthesis through the Wolff-Chaikoff effect. Iodinated contrast media are commonly utilized in hysterosalpingography (HSG) as part of female fertility work-up. When conception occurs shortly after HSG with iodinated contrast, a temporary reduction of maternal and/or foetal thyroid hormone synthesis could jeopardize children's neurodevelopment. We compared the neurodevelopmental outcomes of 6-9-year-old children (n=69) conceived <6 months after HSG with 5-10 ml of oil-based contrast (iodine content: 480mg/ml) or water-based contrasts (iodine content: 250mg/ml) in the follow-up of a nationwide randomised controlled trial (H2Oil trial; Netherlands; 2012-2014; NCT05168228). A community sample of naturally-conceived children (n=44) with similar age, sex and parental education was used as a comparison group (NTR9574). Primary outcomes were intelligence (Wechsler’s Intelligence Scale for Children V), behaviour questionnaires for parents and teachers (Strengths and Difficulties Questionnaire (SDQ); Strengths and Weaknesses of ADHD Symptoms And Normal behaviour (SWAN)), and academic performance. Secondary outcomes were neurocognitive domains assessed in computerized tasks focussing on Processing & Control, Verbal Memory, Visual Memory, Verbal Working Memory, Visual Working Memory, and Visuomotor Integration (Emma Toolbox for Neurocognitive Functioning). We adjusted linear regression models for age, sex, and parental education, applying FDR correction for multiple comparisons. Additional analysis looked at children conceived within 4 weeks, 4-12 weeks, or >12 weeks after HSG. Children conceived <6 months after HSG had lower performance on intelligence tests (-6.81; 95%CI -10.97 to -2.65; p=0.02) and the neurocognitive domain Processing & Control (-0.52; 95%CI-0.84 to -0.19; p=0.02), with processing speed and consistency affected. No differences were found for other neurocognitive domains, behaviour or academic performance. In comparison to naturally-conceived children, children conceived <4 weeks after HSG had lower performance on intelligence tests, but there was no difference for children conceived 4-12 weeks and >12 weeks after HSG. Replication studies with higher power are needed to further evaluate the safety of iodinated contrast media use periconception, including their effects on thyroid function and children's neurodevelopment. Closer monitoring and treatment of thyroid dysfunction in the months following HSG may be warranted. Presentation: 6/1/2024