Journal of molecular endocrinology最新文献

Estrogens are steroid hormones that regulate antioxidant and mitochondrial bioenergetic metabolism in addition to activating nuclear genomic pathways. Concentrating these effects within the mitochondria is a novel strategy for ameliorating mitochondrial dysfunction, which is characteristic of cancer, metabolic, and neurodegenerative diseases. The use of synthetic mitochondria-targeted estrogens containing a triphenylphosphonium group may provide a basis for improving mitochondrial function in these conditions. Here, we evaluate the effects of two compounds, one derived from 17β-estradiol (mitoE2) and the other from 17α-ethinylestradiol (mitoEE2), on cell viability in MCF-7 and CCD-1112Sk cells. We further examine their influence on the activities of superoxide dismutase (MnSOD), citrate synthase (CS), cytochrome c oxidase (COX), and ATP synthase, as well as on the glycolytic reserve and cellular respiration. In both cellular models, cell viability assays indicated that mitoE2 was well tolerated below 500 nM, while mitoEE2 allowed treatments up to 100 nM for up to 24 h. We found that the molecules act differently on enzymatic targets. Exposure of MCF-7 cells to mitoE2 resulted in reduced MnSOD activity. Pretreatment with mitoE2 or mitoEE2 restored the viability of MCF-7 cells exposed to H2O2-induced oxidative damage to levels comparable to untreated controls. In addition, mitoEE2 increased the activities of CS and COX. Both mitochondria-targeted estrogens increased glycolytic reserve and mitochondrial respiration, as determined by extracellular flux assays. Overall, these findings suggest that the antioxidant and bioenergetic effects observed encourage further investigation into their potential as therapeutic strategies for conditions linked to mitochondrial dysfunction.

Orbital fibroblast proliferation and activation contribute to the development of thyroid-associated ophthalmopathy (TAO). In this study, nuclear receptor subfamily 4 group A member 3 (NR4A3) was predicted to play a role in TAO based on bioinformatics analysis. Validation of NR4A3 expression in human TAO orbital samples confirmed its elevated levels compared to normal controls. In vitro studies demonstrated that transforming growth factor beta 1 (TGF-β1)-induced NR4A3 expression in human TAO orbital fibroblasts (OFs) enhanced cell viability, DNA synthesis, and fibrotic marker expression. Conversely, NR4A3 knockdown inhibited these fibrotic responses, suggesting a pro-fibrotic role for NR4A3 in TAO. In vivo experiments further validated these findings, with NR4A3 knockdown in a TAO mouse model leading to reduced pathological injury and fibrosis in orbital tissues. In addition, NR4A3 knockdown decreased the expression of fibrotic markers in the orbital tissues of TAO mice, corroborating the in vitro results. Finally, NR4A3 was shown to modulate the nuclear factor kappa B (NF-κB) pathway, which is activated in TAO. NR4A3 overexpression enhanced, while its knockdown suppressed, NF-κB activation in both human TAO OFs and orbital tissues from TAO mice. These findings suggest that NR4A3 promotes TAO progression through its pro-fibrotic effects and activation of NF-κB signaling, highlighting its potential as a therapeutic target for TAO. Collectively, NR4A3 plays a pivotal regulatory role in both fibroblast proliferation and the fibrotic response in TAO, acting through mechanisms involving the NF-κB signaling pathway. Its ability to enhance TGF-β1-induced changes and activate NF-κB underscores its potential as a key therapeutic target for addressing the complex pathophysiology of TAO.

Approximately 10% of children born small for gestational age (SGA) fail to achieve catch-up growth, resulting in persistent short stature and eligibility for growth hormone (GH) therapy under established guidelines. Pathogenic variants in insulin-like growth factor 1 receptor (IGF1R) are associated with SGA, syndromic short stature, neurocognitive impairment, and variable responsiveness to GH therapy. This study aimed to characterize the clinical phenotype and elucidate the molecular mechanism underlying a rare intronic variant in IGF1R identified in an affected family. Here, we performed whole-exome sequencing (WES) on a single individual, followed by segregation studies in the family and Sanger sequencing. cDNA studies were pursued to evaluate mis-spliced transcripts. WES of the proband's affected mother revealed a rare heterozygous variant in IGF1R (NM_000875.5): c.3722+5G>A. Sanger sequencing confirmed segregation of the variant with the affected status in available family members. cDNA analysis showed that the variant results in intronic retention of 134 nucleotides immediately following the penultimate exon of IGF1R. This leads to a frameshift and introduction of a premature truncation codon, supporting the classification of the variant as likely pathogenic. Our study highlights the utility of genetic testing in SGA children with persistent short stature. By characterizing a novel IGF1R intronic variant causing aberrant splicing, we expand the understanding of its clinical spectrum and molecular underpinning. The findings underscore the importance of molecular diagnostics in unexplained short stature and neurodevelopmental disorders and may inform future therapeutic strategies targeting the IGF1R signaling.

While pregnancy is known to be an inflammatory condition, preeclampsia (PE) is associated with higher chemokines and pro-inflammatory cytokines and higher Th1/Th2 and Th17/Treg ratios. Since the uteroplacental space can secrete cytokines, including TNF and IL1B, a common assumption is that the proinflammatory immune cell profile of Th1 and Th17 cells dominating over Th2 and Treg cells begins in that space. To date, a possible role for endothelium in this initiation process has not been considered. Nonetheless, recent publications show that endothelium can become immunomodulatory on exposure to TNF and IL1B, and in systemic hypertension, endothelium has been shown to exist as multiple cell subtypes. We have recently shown that uterine artery endothelial cells from late-pregnant sheep (P-UAEC) treated with TNF alone secrete many of the chemokines and cytokines further elevated in PE subjects. Herein, we show that P-UAEC also exist in multiple subtypes with distinct chemokine and cytokine secretory and immunomodulatory properties. The five subtypes are differentially regulated by TNF-alpha (TNF) and IL1-beta (IL1B), which may favor subtype-specific binding and interaction with distinct classes of Th cells, and an altered ability to respond to Th-secreted cytokines (such as IL17 and IL10). Thus, our data demonstrate the possibility that certain endothelial cell subtypes can be pushed to express immunomodulatory proteins by early exposure to increases in TNF or IL1B of immune cell, trophoblast, and decidual origin. This, in turn, begs the question of whether such endothelial changes could contribute to subsequent immune disturbances seen at the time of clinical presentation.

The glucagon-like peptide-1 receptor (GLP-1R) and glucose-dependent insulinotropic polypeptide receptor (GIPR) are important incretin receptors that are therapeutic targets for the treatment of type 2 diabetes and obesity. This study extensively characterised the metabolic phenotype of mice with global deletion of either the GLP-1R or GIPR side by side under identical conditions. Age-matched male wild-type (WT) C57Bl6NTac, GLP-1RKO or GIPRKO mice were placed on a high-fat or chow diet for 12 weeks, and a range of in vivo (weight gain, food intake, glucose tolerance, insulin tolerance, and whole-body energy metabolism) and ex vivo (white adipocyte lipolysis, brown adipose tissue and liver mitochondrial function, adipocyte and islet size, and hepatic steatosis) parameters were measured. While both WT and GLP-1RKO mice gained weight similarly on a HFD, obese high-fat-fed GLP-1RKO mice had altered glucose and insulin tolerance, and exhibited hepatic steatosis, highlighting the physiological importance of the GLP-1R in the regulation of blood glucose and lipid homoeostasis. In contrast, GIPRKO mice were partially resistant to diet-induced obesity compared to the WT mice, which was associated with a small reduction in food intake and intact epididymal and subcutaneous white adipocyte β-adrenoceptor-mediated lipolysis. Similarly, WT mice treated with a GIPR antagonist prevented weight gain due to a reduction in food intake on a HFD. These findings provide further support that the GLP-1R is important for normal glycaemic control, whereas the GIPR may play a role in the regulation of body weight.

Bone marrow stromal cells (BMSCs) play an important role in bone regeneration, but their functional activity is affected by oxidative stress, which is a key pathological feature of osteoporosis. The aim of this study was to investigate the effects of capsaicin on the proliferation and differentiation of BMSCs under oxidative stress. We assessed cell viability and osteogenic potential of capsaicin in promoting BMSC survival and enhancing osteogenic capacity under oxidative stress by cell counting kit-8 (CCK-8), reactive oxygen species fluorescence staining, alkaline phosphatase (ALP) staining, Alizarin Red S (ARS) staining, Western blot (WB), and real-time PCR (RT-PCR). Our results indicate that capsaicin improves cell viability, antioxidant capacity, and osteogenic differentiation in rat BMSCs treated with hydrogen peroxide (H2O2). In addition, immunohistochemistry (IHC) analysis revealed that the surface of BMSCs expressed the capsaicin receptor transient receptor potential vanilloid protein 1 (TRPV1). More importantly, capsaicin increased Ca2+ influx and autophagy and inhibited phosphorylation of the PI3K/AKT/mTOR signaling pathway. In conclusion, capsaicin protects BMSC function during oxidative stress, possibly through inducing TRPV1-mediated Ca2+ influx and PI3K/AKT/mTOR-activated autophagy. The results suggest the potential of capsaicin as a therapeutic agent for osteoporosis.

Aldosterone is synthesized by the CYP11B2 enzyme, primarily in the zona glomerulosa of the adrenal gland. It exerts its classical effects on sodium and water balance in the renal distal nephron through binding to the mineralocorticoid receptor (MR). Excess aldosterone production or overactivation of the MR outside the distal nephron leads to cardiac, renal, and vascular injury by increasing oxidative stress and activating the inflammatory and fibrotic pathways. MR antagonists (MRAs) have proved effective at decreasing organ damage and the deleterious effects of excess aldosterone/MR activation. However, MRAs do not fully block the non-genomic effects of aldosterone, which may contribute to residual risks. CYP11B2 inhibition has emerged as an additional therapeutic approach to decreasing the deleterious genomic and non-genomic effects of aldosterone. The development of specific aldosterone synthase inhibitors (ASi) has proved challenging due to the considerable similarity between aldosterone synthase and 11β-hydroxylase, an enzyme encoded by the CYP11B1 gene that catalyzes cortisol synthesis. In this review, we summarize the latest developments on preclinical evidence and clinical trials for ASi and explore the potential clinical advantages of ASi.

Type 1 diabetes (T1D) is caused by autoimmune destruction of pancreatic β-cells. The insulin B-chain 9-23 (insB9-23) peptide is a critical epitope in triggering T1D. In our previous study, we showed that Parabacteroides distasonis, a human gut commensal, contains an insB9-23 mimic in its hprt protein (residues 4-18). This mimic (hprt4-18) peptide activates insB9-23-specific T cells, and P. distasonis colonization enhanced diabetes in NOD mice. However, the impact of the P. distasonis colonization on inflammation, gut microbiome, intestinal immune cells, gut permeability, cytokine, and serum metabolome profiles remained unknown. Here, we investigated these effects using specific pathogen-free (SPF) and germ-free (GF) female NOD mice. P. distasonis colonization minimally impacted gut microbiome composition, altering only 28 ASVs. In P. distasonis-colonized mice, there was a reduction in T-helper, T-effector, and B-cell populations in the intraepithelial lymphocytes, indicating a potential decrease in immune activation. Furthermore, P. distasonis colonization did not alter serum metabolome and circulating cytokine profiles (except for a decrease in IL-15) and gut permeability gene expressions. P. distasonis colonization in GF NOD mice induced severe insulitis without affecting gut permeability. Interestingly, mice gavaged with heat-inactivated (HI) P. distasonis did not affect insulitis scores or immune cell composition. These findings support our hypothesis that P. distasonis functions as a gut commensal, exerting no effect on the gut microbiome, metabolome, gut permeability, intestinal immune cell composition, or nonspecific immune activation. Instead, P. distasonis appears to trigger an insB9-23-specific immune response, potentially accelerating T1D onset in NOD mice through molecular mimicry.

Hypoxia has been implicated as a causal factor in mediating adipocyte dysfunction in obesity. Moreover, protein kinase D 1 (PKD1), a serine/threonine protein kinase, has been shown to contribute to diet-induced adiposity. Therefore, we investigated if PKD isoforms mediate hypoxia-induced dysfunction in 3T3-L1 adipocytes. Hypoxia increased phosphorylation of PKD1 at serine 916 (S916), the autophosphorylation site linked to PKD1 activation, indicating hypoxia-induced activation of PKD1 in adipocytes. Inhibition or depletion of PKD isoforms mitigated hypoxia-induced increase in hypoxia-inducible factor 1α (HIF1α), the master transcription factor mediating hypoxia-induced gene expression, confirming that PKDs modulate the hypoxia-induced mechanism in adipocytes. Surprisingly, depletion of PKD1 and PKD2, but not PKD3, attenuated hypoxia-induced HIF1α target gene expression. Unlike PKD3, PKD1 and PKD2 possess a unique PDZ-binding motif at their C-terminus. Indeed, hypoxia upregulated a PDZ-containing scaffold protein Na+/H+ exchanger regulatory factor 1 (NHERF1) and its interaction with PKD1, whereas NHERF1 depletion attenuated hypoxia-induced PKD1 phosphorylation, HIF1α protein accumulation, and gene expression. Mechanistically, hypoxia induced nuclear import of active PKD1, which phosphorylated histone deacetylase 5 (HDAC5) at S498, promoting cytoplasmic localization of HDAC5. HDAC5 deacetylated heat shock protein 70 (HSP70) at lysine 77, which dissociated HSP70 from HIF1α, allowing HSP90 association that stabilized HIF1α. Interestingly, PKD inhibition reversed hypoxia effects on subcellular localization of PKD1/HDAC5, HSP70 acetylation, and HIF1α/HSP90 association. In summary, our findings reveal an NHERF1-PKD1-HDAC5 mechanism modulating hypoxia-induced gene expression in adipocytes.