Endocrinology最新文献

Here we describe organoid cultures derived from pig foliate taste papillae in which the cellular heterogeneity of the lingual epithelium is preserved. Pig taste organoids were maintained long term (18 passages) and continued to express taste stem cell markers (LGR4, LGR6, and SOX2) and taste receptor cell (TRC) markers (cytokeratin 20, ENTPD2, GNAT3, and OTOP1). We show insulin is necessary for optimum proliferation and differentiation of taste organoids. Some TRCs in the organoids contained insulin and the insulin-critical transcription factors MAFA and PAX4. However, we did not see any evidence of the critical glucose-responsive PDX-1 expression either in the native tissue or in the organoids. We optimized differentiation conditions for TRC expression and separately for increased insulin protein content (6.5-fold, P < .01 vs spontaneous differentiation). Insulin production in differentiated organoids was responsive to cAMP stimuli. These results provide a pig model of taste organoid culture that can be used to study taste stem cell dynamics and taste receptor cell differentiation. These findings suggest that taste organoids may serve as a novel renewable model system for studying extra-pancreatic, nonglucose-regulated insulin and its potential role as a trophic factor.

The transcription factor thyroid hormone receptor β (TRβ), a recognized tumor suppressor, interacts with chromatin-modifying protein complexes to modulate the transcriptome and induce a tumor suppression gene regulatory network. Recent studies have linked poorly differentiated and anaplastic thyroid cancers to aberrant epigenomic signaling, chromatin accessibility, and gene expression. As no enduring treatments are available for these aggressive thyroid cancers and treatment-resistant disease, unveiling the epigenomic coregulatory proteins mediating TRβ signaling will advance the understanding of the molecular mechanisms of TRβ action to block tumor progression and reveal potential novel therapeutic targets. In this review, we summarize novel findings on the epigenomic landscape in the context of TRβ in thyroid malignancy, including the identification of previously unrecognized TRβ interactors and the mapping of 9 distinct functional protein communities that constitute the TRβ interactome in thyroid cells. We also explore how targeting TRβ interactors using existing epigenetic enzyme inhibitors-such as histone deacetylase, lysine-specific histone demethylase 1A, and bromodomain and extraterminal domain; inhibitors-in combination with TRβ agonists, may work synergistically to reprogram tumor epigenetics and suppress oncogenic transcriptional programs.

Seasonal changes in a photoperiod regulate multiple physiological systems in vertebrates, including metabolism, reproduction, and immune function. Kidney mass and renal physiology are known to vary annually, but the endocrine and molecular mechanisms underlying these changes are poorly defined. Prolactin (PRL), a photosensitive hormone is implicated in seasonal energy rheostasis, yet its role in programmed regulation of renal physiology is unknown. Using Djungarian hamsters (Phodopus sungorus), we investigated how photoperiod and PRL regulate seasonal changes in kidney mass, morphology, and transcriptome. Ingestive behavior, kidney histology, and transcriptomic profiles were assessed. We found that long photoperiods and PRL treatment induced renal hypertrophy and convoluted tubule expansion, whereas exposure to short photoperiods resulted in a reduction in all measurements. Transcriptomic analysis revealed photoperiod- and PRL-responsive gene modules related to mitochondrial metabolism, solute transport, and epithelial remodeling. Among these, Cdh2, encoding N-cadherin, was downregulated by long photoperiods and PRL, and negatively correlated with convoluted tubule diameter, suggesting a role in epithelial adhesion during tubular expansion. These findings place prolactin as a key hormonal effector for programmed seasonal kidney function and identify Cdh2 as a target to drive renal physiology.

Numerous studies have implicated glucocorticoids in the regulation of somatotroph differentiation. However, few studies have investigated a requirement for glucocorticoid receptors (GR) in this process. We hypothesized that GR is essential for the normal ontogeny of pituitary growth hormone (GH) during mouse embryonic development. Anterior pituitary cells were isolated from e12.5 to e13.5 mice and e11 chickens and cultured with or without corticosterone (CORT) in the absence or presence of ZK98299, a GR-specific antagonist. CORT induced GH mRNA expression in pituitary cells from both species, and this response was blocked by inclusion of the GR antagonist. Mouse embryos with pituitary-targeted knockout of GR were generated utilizing the cre-LoxP Recombinase system under control of the pituitary-specific alpha-glycoprotein subunit (αGSU) promoter. All cre-positive GR(-/-) embryos died at birth. Therefore, anterior pituitary, brain, heart, liver, and muscle tissues, were collected on embryonic days 17.5/18.5 for RNA isolation and RT-qPCR analysis. Cre mRNA expression was only found in the pituitary, and GR mRNA levels were significantly decreased in the pituitaries of GR(-/-) embryos. GH mRNA was significantly decreased in pituitary-targeted GR(-/-) knockout embryos in comparison to wild-type GR(+/+) embryos. Significant differences in expression of other pituitary hormones in GR(-/-) embryos were not observed, indicating that the effect of pituitary-targeted knockout of GR was restricted to disruption of GH gene expression. To our knowledge, this is the first report that homozygous GR knockout in the anterior pituitary gland in mice suppresses embryonic GH expression, confirming an essential role for GR signaling in the normal ontogeny of somatotrophs.

Damage to pancreatic β-cells serves as a critical pathological basis in the progression of diabetes. Berberine (BBR), an isoquinoline alkaloid, potentially protects pancreatic β-cells, exerting hypoglycemic effects. However, the dose-response relationship and the specific protective mechanism are still unclear. Hormesis is a self-protective response triggered by mild stimuli and has been reported to determine the extent to which phytochemicals can combat diabetes. In this study, we found that BBR exhibited a typical hormetic effect in IL-1β-induced damage to pancreatic β-cells, where low doses of BBR protect cells while high doses aggravate the damage. A model-based approach was used to describe dose-response relationships, as well as to detect and estimate hormetic effects. In addition, the regulatory effect of BBR in preventing apoptosis in pancreatic β-cells was confirmed, and an appropriate dose of BBR stabilized the mitochondrial membrane potential and prevented DNA damage. Moreover, the results showed that the hormetic effect of BBR was closely related to p53 and apoptosis pathways. To further investigate the role of the p53-mediated apoptosis pathways, our study interfered with the p53 pathway, resulting in the attenuation of the hormetic effect of BBR. These results introduce the concept of hormesis to study the biphasic effects of berberine on damaged pancreatic β-cells, while also exploring the relationship between the hormetic mechanism of BBR and the p53-mediated apoptosis pathway. These findings provide clues to explore the potential application of BBR in treating diabetes.

Successful testis development relies on the coordinated differentiation and assembly of various cell types to establish both endocrine and reproductive functions. The ubiquitin ligase NEDD4 has emerged as a key player in murine testis development, with this enzyme being implicated in gonadal sex determination and spermatogonial stem cell differentiation. Here, we report hitherto uncharacterized roles of NEDD4 in postnatal testis development. Utilizing Nr5a1- and Amh-Cre drivers to conditionally ablate Nedd4 in testicular somatic cells, we show that NEDD4 promotes Sertoli cell proliferation through the modulation of the PI3K-AKT signaling pathway. This ubiquitin ligase also ensures proper differentiation of adult Leydig cells and may contribute to murine steroidogenesis. Furthermore, NEDD4 is essential for adrenal gland differentiation, as its loss results in adrenal dysgenesis. These findings highlight NEDD4 as a crucial factor in testis development, emphasizing the importance of ubiquitination and post-translational modifications in reproductive biology.

Context: Given the lack of effective medical treatment for pheochromocytomas (PCCs), a reliable in vitro model is needed to explore new therapies. Organoids are three-dimensional (3D) self-renewing structures that exhibit key features of their tissue of origin, providing valuable platforms for disease modeling and drug screening.

Objective: This study aimed to establish and characterize organoid cultures of canine normal adrenal medullas and PCCs.

Methods: Normal adrenal medullas from healthy dogs and tumor tissue from client-owned dogs with PCC were used to develop organoids. Primary cell suspensions were cultured in a 3D matrix, and organoids were established under optimized conditions. Organoids were characterized using histology, immunohistochemistry, immunofluorescence, qPCR, and metanephrine analysis by LC-MS/MS.

Results: Five adrenomedullary organoid lines were successfully established, demonstrating sustained growth. Organoid cultures were also derived from 9 PCCs, although expansion was limited after passages 1 to 2. Both adrenomedullary and PCC organoids expressed differentiation markers (chromogranin A, synaptophysin, phenylethanolamine N-methyltransferase) and stem/progenitor markers (nestin, SOX10). Organoids retained key functional traits, as indicated by metanephrine levels in culture supernatants, which initially mirrored primary tumor patterns. A decline in both differentiation marker expression and metanephrine levels was observed over time, possibly due to organoid dedifferentiation or selective loss of differentiated chromaffin cells.

Conclusion: This study demonstrates the establishment of the first adrenomedullary and PCC organoid lines. While further optimization is needed, these organoids offer valuable potential as an in vitro model to investigate PCC pathophysiology and explore novel treatment strategies for this therapeutically challenging tumor.

Objective: This study aimed to investigate the impact of hypothyroidism on pulmonary vascular remodeling (PVR) in pulmonary hypertension (PH) mice and the therapeutic effects of levothyroxine (L-T4).

Methods: Male C57BL/6J mice were administered methimazole (MMI; 40 mg/kg/day) to induce hypothyroidism. PH was established using Sugen5416 combined with hypoxia (SuHx). Thyroid function was assessed by measuring serum free T4 (FT4) and TSH levels via ELISA. Echocardiography and hemodynamics were evaluated using the Vevo 3100 system and right heart catheterization. Pulmonary vascular morphology was analyzed by hematoxylin-eosin and Masson staining. Western blot and assay kits were used to assess inflammation, oxidative stress, and NF-κB pathway activation.

Results: SuHx-induced PH resulted in PVR, as evidenced by decreased pulmonary artery acceleration time (PAT) and PAT/pulmonary ejection time ratio, increased right ventricular (RV) systolic pressure, collagen deposition, and α-smooth muscle actin expression, along with RV dysfunction indicated by reduced tricuspid annular plane systolic excursion. MMI treatment for 4 weeks significantly lowered serum FT4 levels and increased TSH levels, inducing hypothyroidism. Compared to SuHx mice, SuHx + MMI mice exhibited exacerbated PH, RV dysfunction, and PVR, accompanied by increased levels of IL-1β, IL-6, TNF-α, and malondialdehyde; decreased glutathione levels and superoxide dismutase activity; and enhanced NF-κB pathway activation. L-T4 intervention attenuated these pathological changes.

Conclusion: Hypothyroidism exacerbates SuHx-induced PH by promoting PVR, inflammation, oxidative stress, and NF-κB pathway activation in mice. L-T4 supplementation alleviates these pathological changes. This study provides theoretical insights into the pathogenesis of hypothyroidism-related PH.

Vertebrate reproduction is controlled by 2 pituitary gonadotropin hormones (GtHs), FSH and LH, binding to gonadotropin hormone receptors (GtHRs) in gonadal tissues. All gnathostome vertebrates have been confirmed to possess at least 1 receptor for each GtH [LH receptor (LHR) and FSH receptor (FSHR)], except for species of the reptilian (nonavian sauropsidan) orders, such as lepidosauria, testudines, and crocodylia, which showed inexplicable reactions to heterologous amphibian, avian, and mammalian GtHs in early endocrinological studies. This study investigated the number and function of reptilian GtHRs. Genomic and transcriptomic analyses of selected tetrapod species now strongly suggest the inactivation of the LHR in all nonavian sauropsidans. This gene inactivation likely occurred independently in 3 branches of the sauropdisan clade, sparing only the avian class. Bioassays served to investigate the binding specificity of squamate, chelonian, crocodilian, avian, and mammalian GtHRs with their homologous and heterologous GtHs. The FSHR of a squamate lizard proved completely promiscuous to both its homologous GtHs, while the chelonian FSHR responded slightly stronger to the homologous LH than FSH, and the crocodylian FSHR was only stimulated by the homologous LH but not FSH. We therefore propose a modified paradigm with a neuroendocrine control of nonavian reptilian reproduction by a single GtHR and either 1 GtH in crocodylians or 2 GtHs in chelonians and squamate reptiles. Finally, we discuss hypotheses of tightly regulated temporal and spatial expression of the remaining FSHR in different gonadal somatic cells and temperature-dependent functions of the single nonavian reptilian GtHR.