Endocrine Research Articles

A small molecule K-3 promotes PDX1 expression and potentiates the differentiation of pluripotent stem cells into insulin-producing pancreatic β cells

Abstract Insulin-producing pancreatic β-like cells derived from human pluripotent stem cells (PSCs) are anticipated as a novel cell source for cell replacement therapy for diabetes patients. Here, we describe the identification of small molecule compounds that promote the differentiation of the PSCs into insulin-producing cells by high throughput screening with a chemical library composed of 55,000 compounds. The initial hit compound K-1 and one derivative K-3 increased the proportion of PSC-derived insulin-positive endocrine cells and their glucose-stimulated insulin secretory (GSIS) functions. K-3 preferentially acts on stage 3 pancreatic progenitor cells and increases the population expressing high levels of PDX1. As a result, the ratios of the PSC-derived PDX1 / NKX6.1 double-positive endocrine progenitor and INS / NKX6.1 double-positive mono-hormonal endocrine cells were increased. K-3 enhances the expression of functional pancreatic β cell markers and affects biological processes concerning organ development. K-3 also increased the yield of endocrine cells at the end of stage 5. The novel compound is a beneficial new tool for efficiently generating PSC-derived insulin-producing cells with high functionality and differentiation efficiency.

Recent advances in the understanding of gonadotrope lineage differentiation in the developing pituitary.

The pituitary gland is a vital endocrine organ regulating body homeostasis through six hormone-secreting cell types. Among these, pituitary gonadotrope cells are essential for reproductive function. Throughout pituitary ontogenesis, gonadotrope cells differentiate in a stepwise process, involving both morphogenic cues and transcription factors, which drives specification of progenitor cells into specialized endocrine cells. It is crucial to understand the mechanisms underlying gonadotrope differentiation, as developmental defects and abnormalities in this process can lead to many reproductive pathologies. This review offers a detailed overview of the latest advances in gonadotrope cell differentiation. We addressed this question with a specific focus on three important aspects of gonadotrope differentiation: the identification of the progenitor population giving rise to gonadotrope cells, the early mechanisms that initiate Nr5a1 expression and thus gonadotrope fate commitment and finally, the mechanisms driving the formation of physical and functional gonadotrope networks. Overall, this review aims to provide new insights into three aspects of the gonadotrope differentiation process by reconsidering pioneering studies in the light of data gained from latest technological developments. Firstly, we re-investigated the long debated developmental trajectory of pituitary gonadotrope cells. Secondly, we reported new regulatory mechanisms of Nr5a1 expression, focusing on the involvement of ERα. Finally, we highlighted the molecular and cellular mechanisms driving gonadotrope network formation during embryogenesis, a process that seems essential for regulation of gonadotrope activity.

Leveraging pre-trained machine learning models for islet quantification in type 1 diabetes

Human islets display a high degree of heterogeneity in terms of size, number, architecture, and endocrine cell-type compositions. An ever-increasing number of immunohistochemistry-stained whole slide images (WSIs) are available through the online pathology database of the Network for Pancreatic Organ donors with Diabetes (nPOD) program at the University of Florida (UF). We aimed to develop an enhanced machine learning-assisted WSI analysis workflow to utilize the nPOD resource for analysis of endocrine cell heterogeneity in the natural history of type 1 diabetes (T1D) in comparison to donors without diabetes. To maximize usability, the user-friendly open-source software QuPath was selected for the main interface. The WSI data were analyzed with two pre-trained machine learning models (i.e., Segment Anything Model (SAM) and QuPath's pixel classifier), using the UF high-performance-computing cluster, HiPerGator. SAM was used to define precise endocrine cell and cell grouping boundaries (with an average quality score of 0.91 per slide), and the artificial neural network-based pixel classifier was applied to segment areas of insulin- or glucagon-stained cytoplasmic regions within each endocrine cell. An additional script was developed to automatically count CD3+ cells inside and within 20 μm of each islet perimeter to quantify the number of islets with inflammation (i.e., CD3+ T-cell infiltration). Proof-of-concept analysis was performed to test the developed workflow in 12 subjects using 24 slides. This open-source machine learning-assisted workflow enables rapid and high throughput determinations of endocrine cells, whether as single cells or within groups, across hundreds of slides. It is expected that use of this workflow will accelerate our understanding of endocrine cell and islet heterogeneity in the context of T1D endotypes and pathogenesis.

An ultrasensitive fluorescent strategy for 17β-estradiol based on aptamer and isothermal exponential amplification reaction

The abuse of 17β-estradiol (E2) in breeding and the excretion into the environment by human beings result in exposure of E2 to humans. Excessive levels of E2 can cause an adverse effect on the human endocrine systems. Therefore, an efficient and sensitive method for the analysis of E2 is required. Herein, based on the specific capture of aptamer and the digestion od Exonuclease III, efficient amplification of isothermal exponential amplification reaction (EXPAR), a highly sensitive and selective strategy is established for E2 analysis. E2 binds to the aptamer due to their high affinity, preventing the complementary DNA (cDNA) of the aptamer from hybridizing with it. Thus, the cDNA remains unbound and freely available in the solution. Then, Exonuclease III digests the cDNA-aptamer complex, leaving the free cDNA intact. cDNA serves as primers to trigger EXPAR with the help of Bst 2.0 WarmStart DNA polymerase and Nt.BstNBⅠ nicking enzyme, achieving sensitive detection of E2. Without E2, cDNA hybridizes with the aptamer to form double-stranded DNA, which is degraded by Exonuclease III. As a result, the amplification reaction fails to initiate. The approach shows a linear range of 100 aM-10 pM, spanning 5 orders of magnitude, with the limit of detection as low as 36 aM. In addition, the selectivity and reproducibility are great, and the recoveries in tap water and milk ranged from 99.4% to 117.3%, suggesting good practicability. This method may also provide a new possibility for highly sensitive detection of other small-molecule targets via using the corresponding aptamers.

Histomorphometric changes in pituitary gonadotropic endocrinocytes when exposed to dark deprivation

Aim. To assess the effect of 30-day dark deprivation on functional and histomorphometric changes in adenohypophysis gonadotropic endocrinocytes and their reversibility in mature male rats.Materials and methods. Mongrel white male rats (n = 36) weighing 365–375 g at 4 months of age were randomly divided into three groups (each n = 12). For 30 days the control group was in automatic light-dark mode 12/12, and the rats of experimental groups 1 and 2 were in round-the-clock artificial lighting (24/0, 300 Lux), then the rats of group 2 were returned to 12/12 mode for the next 14 days. In the animals of the control and group 1 during their lifetime on the 31st day, and in group 2 on the 45th day, blood was taken from the abdominal aorta and levels of follicle-stimulating (FSH) and luteinizing (LH) hormones, melatonin, and Klotho protein were determined an enzyme-linked immunosorbent assay and immunoassay and after which they were removed from the experiment by decapitation. Postmortem histological and immunohistochemical examination of the pituitary gland was done using rabbit polyclonal antibodies targeting caspase-3 and Klotho protein, as well as morphometry. Statistical data processing was performed using the Kruskal-Wallis test with post-hoc Dunn’s test.Results. Light desynchronization in the form of 30 days of dark deprivation increased FSH and LH levels and decreased melatonin and Klotho protein levels in the blood of male rats; increased gonadotropic endocrine cell area, volume, and perimeter by 23.1% (p < 0.001), 48.7% (p < 0.001), and 10.9% (p < 0.001), respectively; and increased nucleus area, volume, and perimeter by 16%, 11.7%, and 2.5%, respectively. An immunohistochemical study showed an increase in the specific area of caspase-3-immunoreactive gonadotropic endocrinocytes by 25.2% without obvious morphological signs of apoptosis, and a decrease in the expression of Klotho protein by 25.7%. All indicators were reversible, the levels of FSH and Klotho protein in the blood of animals almost reached their initial values after 14 days of restoration of the light-dark cycle 12/12.Conclusion. Dark deprivation for 30 days in male rats induced reversible processes of accelerated aging and apoptosis in cells, as evidenced by changes in the expression of aging markers in gonadotropic endocrinocytes and levels of gonadotropic hormones in the blood. When the light-dark mode is restored, the levels of FSH and Klotho protein normalize as early as 14 days.

Characterization of Hippo Signaling Components in the Early Dorsal Pancreatic Bud.

YAP1 expression in the early mouse pancreatic anlagen is low until approximately E11.5, when it becomes localized to cell nuclei in multipotent progenitor cells. At E14.5, we find nuclear YAP1 in ductal cells.YAP1 is not expressed in early and midgestation endocrine cells. By contrast, TAZ is expressed in first transition endocrine cells.Hippo regulators MERLIN and LATS1/2 kinases are robustly expressed in the early pancreatic bud by E10.5. Both MERLIN and LATS1/2 exhibit strong apical localization in epithelial cells at nascent microlumens. Using in vitro models of de novo pancreas lumen formation, we show that YAP1 nuclear localization is high in early phases of lumen formation and gradually decreases as lumens matures.

Exogenous Opioids and the Human Endocrine System: An Endocrine Society Scientific Statement.

The use and misuse of opioids are a growing global problem. Although the effects of these drugs on the human endocrine system have been studied for decades, attention on their related clinical consequences, particularly on the hypothalamic-pituitary system and bone health, has intensified over recent years. This Statement appraises research data related to the impact of opioids on the gonadal and adrenal function. Whereas hypogonadism is well recognized as a side effect of opioids, the significance of their inhibitory actions on the hypothalamic-pituitary-adrenal system and the occurrence of clinically relevant adrenal insufficiency is not fully elucidated. The often-inconsistent results of studies investigating how opioids affect the secretion of GH, prolactin, arginine vasopressin, and oxytocin are assessed. The accumulating evidence of opioid actions on bone metabolism and their negative sequelae on bone mineral density and risk of fracture are also reviewed. In each section, available data on diagnostic and management approaches for opioid endocrine sequelae are described. This Statement highlights a plethora of gaps in research associated with the effects and clinical consequences of opioids on the endocrine system. It is anticipated that addressing these gaps will improve the care of people using or misusing opioids worldwide. The Statement is not intended to serve as a guideline or dictate treatment decisions.

Effect of Sodium Aminophthalhydrazide on Structural and Functional Characteristics of Pancreatic Islands in Experimental Type 2 Diabetes Mellitus.

Under the influence of inflammation, pancreatic β cells can transdifferentiate into cells with a different phenotype. When inflammation decreases, the opposite process is possible. We studied the effect of intramuscular injection of 5-amino-2,3-dihydrophthalazine-1,4-dione sodium salt (APH) on the structural and functional characteristics of the pancreatic islets in rats with experimental type 2 diabetes mellitus. Insulin-producing, glucagon-producing, and proliferating cells were identified by immunohistochemistry. After APH administration, an increase in the number of β cells, a decrease in the number of α cells and cells synthesizing both insulin and glucagon (insulin-glucagon-positive) were observed; mitotic activity of β cells did not change. It is likely that APH promotes transdifferentiation of α cells into β cells by changing the microenvironment of endocrine cells and reducing inflammation in pancreatic islets.

Comparative analysis of the primary morbidity in the population in the territory of accumulated risk over the post-operation period of a chemical enterprise

Introduction. The long-term operation of the chemical enterprise has led to the formation of an area of accumulated harm to public health. The purpose of the study is to investigate the trend in newly identified morbidity in various population groups living in areas of accumulated chemical pollution of the environment. Materials and methods. The primary morbidity rate of the population of Usolye-Sibirskoye was assessed retrospectively according to official statistical reporting – during 1985–1995. and 2016–2022. Relative rates of incidence among children and adults (per 1000 population) were calculated. The trend in the incidence of malignant neoplasms was studied using regression analysis and growth (decrease) rates. Results. Over 2016–2022 there was a gain in the incidence in the population: in 0–14 years children by classes: certain conditions in the perinatal period, blood diseases, neoplasms; in 15–17 years adolescents: by class of disease of the circulatory system, blood, endocrine and genitourinary systems, congenital malformations, neoplasms; in the adult population by classes of diseases including congenital malformations, diseases of the endocrine system, circulatory system, musculoskeletal system and blood diseases, neoplasms. Limitations are due to changes in the structure of statistical reporting forms and various etiological factors for diseases included in one class of diseases. Conclusion. During the post-operation period of the city-forming enterprise, an increase in incidence in children and adults was revealed. Undoubtedly, the formation of pathology was influenced not only by the unfavourable environmental situation in the city, but also by socio-economic conditions. To optimize medical and preventive measures to improve and preserve public health, it is necessary to conduct further studies of the health status in the population in the area of accumulated chemical pollution.

Optimization of Pancreatic Cell Subset Classification in Images from Multiplex Immunofluorescence Imaging Platforms

Understanding the natural history of type 1 diabetes (T1D) has been hampered by limited access to the target organ (i.e., the pancreas) in living people. To make the most of these precious tissues, cyclic imaging platforms such as Miltenyi MACSima, which increase the number of markers that can be examined per section, are becoming increasingly popular. Such advances in spatial biology require reproducible cell classification algorithms. Random Tree (RT) algorithm was previously found to be the most reliable approach for differentiating exocrine versus endocrine pancreas compartments, yet an unmet need exists for an approach that can provide accurate cell type classification within the endocrine compartment. It was hypothesized that a core set of markers could be used to maximize classification accuracy. To this end, pancreatic sections were stained with fluorescent antibodies against various markers and images were captured using the MACSima platform. RT algorithm was trained in QuPath to classify endocrine, exocrine, and vascular cell clusters in n=3 pancreas donors across a total of n=10 ROIs. Classification accuracy will be determined by comparison to ground-truth labels annotated by an expert in the field. Markers that maximize classification accuracy will be included on future pancreas runs to standardize and streamline downstream analyses.

Thyrotoxic Effects of Mixed Exposure to Perfluorinated Compounds: Integrating Population-Based, Toxicogenomic, Animal, and Cellular Evidence to Elucidate Molecular Mechanisms and Identify Potential Effector Targets.

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are emerging environmental endocrine disruptors that may adversely affect the human endocrine system, particularly the thyroid gland, the largest endocrine gland in the human body. An epidemiologic survey was conducted involving 318 community residents in Shanghai, China, to assess PFAS exposure levels. The relationship between PFAS exposure and five thyroid function indicators was analyzed using Bayesian Kernel Regression (BKMR) and Weighted Quantile Sum Regression (WQS). Ten effector genes related to PFAS and thyroid diseases were identified through the Comparative Toxicogenomics Database (CTD) for bioinformatics analysis and pathways involved were explored through mediation analysis. In vivo validation of these effector genes was conducted using PCR, complemented by in vitro cellular experiments involving transcriptome sequencing and the construction of animal models to simulate mixed PFAS exposure in the general population. Mixed PFAS exposure was found to impact thyroid health primarily through pathways related to lipid metabolism in toxicogenomic studies and resulted in the upregulation of key genes associated with lipid metabolism in animal models. Our results demonstrate that PFAS exposure could affect the expression of lipid metabolism pathways through the modulation of transcription factors, contributing to the development of thyroid disease.

Embryonic macrophages support endocrine commitment during human pancreatic differentiation

Organogenesis is a complex process that relies on a dynamic interplay between extrinsic factors originating from the microenvironment and tissue-specific intrinsic factors. For pancreatic endocrine cells, the local niche consists of acinar and ductal cells as well as neuronal, immune, endothelial, and stromal cells. Hematopoietic cells have been detected in human pancreas as early as 6 post-conception weeks, but whether they play a role during human endocrinogenesis remains unknown. To investigate this, we performed single-nucleus RNA sequencing (snRNA-seq) of the second-trimester human pancreas and identified a wide range of hematopoietic cells, including two distinct subsets of tissue-resident macrophages. Leveraging this discovery, we developed a co-culture system of human embryonic stem cell-derived endocrine-macrophage organoids to model their interaction invitro. Here, we show that macrophages support the differentiation and viability of endocrine cells invitro and enhance tissue engraftment, highlighting their potential role in tissue engineering strategies for diabetes.

Screening of anti-diabetic potential of the siddha formulation sambirani poo kuligai by in-vitro alpha glucosidase enzyme inhibition assay

Background: Noninsulin-dependent diabetes mellitus (NIDDM) is a common disease of the endocrine system caused by the decreased secretion of insulin by the pancreatic Langerhans beta cell or by the lowering of insulin resistance due to excessive absorption of glucose. The Siddha system of medicine is a traditional medical system that uses a scientific and holistic approach to provide preventive, promotive, curative, rejuvenative and rehabilitative health care. According to Siddha literature, diabetes is known as Innippu Neer, Madhumegam and Neerizhivu. The various reasons for the cause of this disease are attributed to foodhabits and lifestyle changes and also due to hereditary causes. One of the therapeutic approaches is to decrease the postprandial hyperglycemia by retarding the absorption of glucose through the inhibition of carbohydrate-hydrolyzing enzymes, such as a-amylase and ?-glucosidase. ?-Glucosidase are enzyme that catalyze the absorption of digested glucose from dietary polysaccharides in the small intestine. Aim: The aim of the present study is to evaluate the anti-diabetic potential of the siddha formulation of Sambirani Poo Kuligai(SPK) by alpha glucosidase enzyme inhibition assay. Method: The spectrophotometric assay method was used to find alpha glucosidase inhibitory activity. Results: SPK showed presence of alpha glucosidase inhibitory potential with the maximum inhibition of about 41.74 ± 3.578 % and the corresponding IC50 is 606.5 ± 49.51?g/ml. Conclusion: This in-vitro study revealed the presence of the alpha glucosidase activity in the siddha formulation Sambirani Poo Kuligai possesses antidiabetic activity

Perioperative selection of blood and components for substitution: Immunohaematological assessment of immunization risk and methods for selection of optimally compatible blood

The aim of this study is to assess the risk for immune and hematologic adverse events in perioperative transfusion of blood components. Our second goal is to propose methods for the selection of an optimally compatible donor in order to limit the negative impact of complications following blood component transfusion on the hospital outcome of patients admitted to clinics of general, gastrointestinal, thoracic, and vascular surgery. The largest group of patients included in this study were patients with gastrointestinal disorders (614 patients; 31%) and patients with diseases of the organs of the blood and lymphatic system (589 patients; 30%). This was followed by patients with diseases of the skin and subcutaneous tissue (368 patients; 18%) and patients with benign and malignant neoplasms (365 patients; 18%). The remaining 65 patients (3%) were diagnosed with diseases of the endocrine system, trauma patients, and patients with genitourinary disorders. The methods used for optimal selection of compatible blood components in this study are enzyme tests, Coombs tests, and tests in agglutinating medium. The study shows that clinically significant antibodies, which could provoke a post-transfusion hemolytic reaction, were detected in 4.3% of the screened patients. In the majority of patients, the specificity of antierythrocyte antibodies cannot be established. For those patients where the specificity of anti-erythrocyte antibodies could be established, the type of antibody and the antigen system to which it belonged were as follows (in descending order): 1. Anti-erythrocyte antibodies belonging to the Rh system: 37% (n = 17) of all screened patients (1.6% of all patients), including anti-E type (5 patients), anti-D (8 patients), anti-C-1, anti-C (2 patients), and anti-Cw (1 patient). 2. In 3 (6% or anti-erythrocyte antibodies belonging to other erythrocyte antigen systems—Kidd-1 patients, Lewis-2 patients—6% of the screened patients (0.3% of all patients). 3. In 57% (n = 26) of those screened (2.4% of all patients), alloantibodies without any known specificity were identified. The largest number of identified antibodies were directed against the D antigen belonging to the Rh system. Most of the anti-D alloantibodies found in Rhesus D (-) negative patients with no history of prior transfusion of D (+) positive red blood cell (RBC) concentrate possibly have resulted from prior Rh isoimmunization during pregnancy, provided that anti-D antibodies persist for a long time after birth—in some of the studied patients, 15–20 or more years. A greater number of alloimmunizations were found in women—28 (61%), compared to men—18 (39%), due to previous sensitization with different blood group antigens during pregnancy. This study shows that timely diagnosis is essential for the selection of appropriate RBC concentrate, for the avoidance of adverse reactions, and for the improvement of hematological parameters after transfusion of blood components. Graphical abstract:

9271 Cholinergic Signaling in the Mouse Embryonic Pancreas Targets Early Endocrine Cells

Abstract Disclosure: C. Duarte: None. J.K. Panzer: None. N. Borowsky: None. A. Caicedo: None. The parasympathetic vagus nerve affects pancreas function by activating local intrapancreatic neurons that release acetylcholine (ACh). These neurons are derived from progenitors of the vagal neural crest and colonize the pancreas during embryonic development. The specific mechanisms by which ACh is released from these neurons influence embryonic development of the islet and, specifically, beta cells remain largely unknown. The purpose of this study was to identify cholinergic signaling components and assess early physiological responses to ACh during murine development of endocrine lineage cells. We extracted pancreatic rudiments from mice at embryonic stages E15 to E18 and stained them for neuronal and endocrine markers, along with components associated with cholinergic signaling. We further performed Ca2+ imaging of the pancreatic rudiments from NGN3CRE-GCaMP3 mice to record responses to ACh in cells of the endocrine lineage. At E15, we observed a significantly higher concentration of glucagon+ cells compared to insulin+ cells, consistent with the earlier differentiation of alpha cells in the developing pancreas. Neuronal body clusters were identified in close proximity to endocrine lineage cells from E15 to E18, with the neuronal network becoming more dispersed and interconnected. At E15, wide distribution of the presynaptic vesicular acetylcholine transporter (VAChT) was observed later becoming localized around insulin+ and glucagon+ cells at E18. Postsynaptic acetylcholinesterase (AChE) colocalized with glucagon+ cells from E15 to E18 and with insulin+ cells by E18. ACh elicited Ca2+ responses in individual endocrine cells as early as E15. Our results show that cholinergic nerve terminals target early endocrine cells and elicit responses to ACh, indicating that local cholinergic neurons innervate and activate endocrine progenitors in the embryonic pancreas. Our current studies are aimed at determining how cholinergic signaling contributes to beta cell differentiation and function. We expect this knowledge to guide future protocols for deriving beta cells from stem cells. Presentation: 6/2/2024

8715 Cholinergic Signaling in the Mouse Embryonic Pancreas Targets Early Endocrine Cells

Abstract Disclosure: C. Duarte: None. J.K. Panzer: None. N. Borowsky: None. A. Caicedo: None. The parasympathetic vagus nerve affects pancreas function by activating local intrapancreatic neurons that release acetylcholine (ACh). These neurons are derived from progenitors of the vagal neural crest and colonize the pancreas during embryonic development. The specific mechanisms by which ACh is released from these neurons influence embryonic development of the islet and, specifically, beta cells remain largely unknown. The purpose of this study was to identify cholinergic signaling components and assess early physiological responses to ACh during murine development of endocrine lineage cells. We extracted pancreatic rudiments from mice at embryonic stages E15 to E18 and stained them for neuronal and endocrine markers, along with components associated with cholinergic signaling. We further performed Ca2+ imaging of the pancreatic rudiments from NGN3CRE-GCaMP3 mice to record responses to ACh in cells of the endocrine lineage. At E15, we observed a significantly higher concentration of glucagon+ cells compared to insulin+ cells, consistent with the earlier differentiation of alpha cells in the developing pancreas. Neuronal body clusters were identified in close proximity to endocrine lineage cells from E15 to E18, with the neuronal network becoming more dispersed and interconnected. At E15, wide distribution of the presynaptic vesicular acetylcholine transporter (VAChT) was observed later becoming localized around insulin+ and glucagon+ cells at E18. Postsynaptic acetylcholinesterase (AChE) colocalized with glucagon+ cells from E15 to E18 and with insulin+ cells by E18. ACh elicited Ca2+ responses in individual endocrine cells as early as E15. Our results show that cholinergic nerve terminals target early endocrine cells and elicit responses to ACh, indicating that local cholinergic neurons innervate and activate endocrine progenitors in the embryonic pancreas. Our current studies are aimed at determining how cholinergic signaling contributes to beta cell differentiation and function. We expect this knowledge to guide future protocols for deriving beta cells from stem cells. Presentation: 6/2/2024

8182 New Mouse Model Mirrors Human MODY8: Opening Doors to Understanding Exocrine-Endocrine Crosstalk in the Diabetic Pancreas

Abstract Disclosure: K. El Jellas: None. V. Salerno: None. L.S. Katz: None. J. Hu: None. G. Fogarty: None. A. Mandal: None. A. DiStefano-Forti: None. D. Scott: None. M. Lowe: None. A. Molven: None. R.N. Kulkarni: None. Maturity-onset diabetes of the young, type 8 (MODY8) is a dominantly inherited form of monogenic diabetes, caused by heterozygous mutations in the carboxyl ester lipase (CEL) gene expressed in pancreatic acinar cells. MODY8 is characterized by chronic pancreatitis and exocrine dysfunction. Despite the intimate anatomical relationship between the endocrine and exocrine pancreas, little is known about the biological components mediating exocrine-endocrine communication in regulating glucose homeostasis. Here, we report a refined mouse model that bears the mutation present in MODY8 patients on one allele, and the humanized normal variable number of tandem repeat (VNTR) of CEL with 16 repeats (16R) on the other, mimicking the genetic make-up seen in MODY8 patients. Examination of glucose homeostasis revealed that inducing stress (e.g. by high-fat diet) leads to glucose intolerance in MODY8/16R mice and a blunted glucose-stimulated insulin-secretion compared to their control littermates. Histopathological analyses demonstrated features of chronic pancreatitis in some pancreatic lobes, including inflammation, acinar atrophy, acinar-to-ductal metaplasia, fibrosis and fat infiltration, mirroring the morphology of the human disease. Moreover, we applied immunolabeling-enabled three-dimensional imaging of solvent-cleared organs (iDISCO) to intact pancreata and found that beta-cell mass was significantly decreased in the MODY8/16R mice, with a large number of islets located within fatty lobes. These results are coupled with comparative proteomics and lipidomic profiling with the aim of understanding the molecular signatures of exocrine and endocrine cells during pathogenesis. In conclusion, we have generated a mouse that recapitulates several features of the exocrine and endocrine phenotype characteristic of human MODY8. This novel model provides a unique opportunity, not possible in humans, to characterize pancreatic endocrine-exocrine communication in a longitudinal manner as a response to diverse environmental stressors. Presentation: 6/2/2024

8467 From Highly Suspected Hemochromatosis to Liver Metastasis Neuroendocrine Tumor

Abstract Disclosure: M.E. Chacon Cruz: None. M. Sanchez Cordero: None. G. Guerra Velazquez: None. K.C. Velez Rivera: None. A neuroendocrine cancer, often referred to as a neuroendocrine tumor (NET) or neuroendocrine neoplasm begins in the specialized cells of the body's neuroendocrine system. These cells have traits of both hormone-producing endocrine cells and nerve cells. The carcinoid is the most common neuroendocrine tumor causing liver metastases, especially when of midgut origin. However, although appendix is the most common location for midgut carcinoids it most unusually gives rise to hepatic spread. NETs are described as functional or non-functional, depending on the release of hormones. About 60% of NETs are non-functional. Case of a 66 year old male patient with medical history of ESRD on HD, PPM placement, hypertension, type 2 diabetes mellitus, and auditory impairment presents to ED of this institution after presenting with RUQ abdominal pain of one day of evolution. Patient's pain is associated with food intake or changes in diet. Laboratory work on admission patient found with leukocytosis in 16.69, anemia 10.5 and transaminitis ALT 180, AST 176 and ALP 589. Abdominal ultrasound shows Hepatomegaly with a slightly irregular surface contour. Correlate for chronic liver disease. Abdomino pelvic CT showed Hepatomegaly with a diffusely heterogeneous parenchyma and ill-defined nodular foci of hypoattenuation. During admission liver enzyme and alkaline phosphatase continue in increasing trend up to 1,172 IU/L. Ferritin in 12,203, Transferrin saturation in 23.71%. Hemochromathosis DNA not detected, Angiotensin convert enzyme in 73 U/L, tumor marker alpha-fetoprotein in 1.8 ng/ml, carcinoembryoninc antigen in 25.63 ng/ml, CA19-9 in 903 U/ml, Serotonin 23 ng/ml. MRCP was ordered and show Hepatomegaly with innumerable T2 hyperintense nodules replacing the hepatic parenchyma, may be related to cirrhosis including regenerative nodules. Interventional radiologist was consulted for liver biopsy and came back positive for Malignant Neuroendocrine Tumor, Favor Metastatic Tumor This case illustrates the challenges physicians face in quickly identifying and diagnosing pathologies as unusual as neuroendocrine tumor. Furthermore, it points out that primary care physicians should consider this disease in the differential diagnosis (DDx) in case of non-specific signs and symptoms such as abdominal pain and how the DDx can change depending on the patient's clinical symptoms and evolution. The case shows us how, with the physical examination that the patient presented, his skin was like that described in hemochromatosis, skin hyperpigmentation (Bronze Skin), weakness, diabetes mellitus, along with elevated levels of ferritin, transaminitis, alkaline phosphatase and the finding of iron deposit in the kidney using CT, our differential diagnosis was our first diagnosis, until the genetics for hemochromatosis came back negative and the liver biopsy was positive for neuroendocrine tumor. Presentation: 6/2/2024

8686 scRNA-seq of pituitary from letrozole-induced PCOS mouse model reveals abnormal prolactin secretion

Abstract Disclosure: G. De Robles: None. N. Ujagar: None. Z. Del Mundo: None. D. Nicholas: None. Polycystic ovary syndrome (PCOS) has a complex pathophysiology and is the most common endocrine disorder among reproductive-aged women. Ovarian hormonal dynamics are regulated via the secretion of the gonadotropin-releasing hormone (GnRH), which stimulates the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the anterior pituitary gland. High serum levels of LH in PCOS patients indicate an increase in GnRH levels, but the mechanisms within the anterior pituitary at a cellular level are unclear. We performed single-cell mRNA sequencing (scRNA-seq) on the pituitaries of the letrozole-induced (LET) mouse model of PCOS to profile the functional genomics of endocrine cell populations relative to serum hormone levels. The population percentage of lactotropes significantly decreased; in contrast, two gonadotrope populations significantly increased in the LET mice compared to the placebo-treated mice. Consistent with these changes, an increasing trend of serum LH levels and a decreasing trend of serum prolactin (PRL) levels were observed in the LET mice, while no change occurred in serum growth hormone levels. A gene set enrichment analysis (GSEA) on the differentially expressed genes (DEGs) from the lactotropes revealed an association with negative regulation of protein kinase activity. These DEGs included Hspb1, Park7, Pcp4, and Ppia, which all share the function of mediating stress-induced apoptosis. A GSEA on the DEGs between the two gonadotrope clusters in the LET mice also confirmed a variation in biological pathways linked to ribosomal subunits, transcription regulation, and the regulation of steroid metabolic processes. Based on the scRNA-seq results of the anterior pituitaries of LET mice, alterations in the proportions of hormone-secreting cells may be a response to hyperandrogenism, in which functionally diverse gonadotropes could contribute to heterogeneity in reproductive phenotypes. Changes in the lactotrope population and PRL serum levels also support further research on the lactation hormone and its role in PCOS. PRL is involved in metabolic homeostasis and reproduction, and understanding its dysregulations may provide additional insight into the pathophysiology of PCOS. Presentation: 6/3/2024

Bone Marrow and Metabolic Bone Disease.

The bone marrow represents one of the largest organs in the body, with a relevant metabolic role that continues to be investigated. Numerous studies have focused on marrow adipose tissue (MAT). Evidence indicates that the bone marrow adipocytes do not only work as storage tissue but also consist of endocrine and paracrine cells, with the potential to contribute to local and systemic metabolism. MAT plays a role in bone health through its interaction with the other components of bone. Many metabolic disorders (osteoporosis, obesity, diabetes) have a complex and still not well-established or understood relationship with bone health. This article surveys the literature on the relationship of bone marrow and metabolic disorders, and how it is being studied using imaging techniques, with a special focus on bone health.