NR5A2/LRH-1 regulates the PTGS2-PGE2-PTGER1 pathway contributing to pancreatic islet survival and function

Investigation of the Pharmacodynamic Components of Gastrodia elata Blume for Treatment of Type 2 Diabetes Mellitus through HPLC, Bioactivity, Network Pharmacology and Molecular Docking

The occurrence of type 2 diabetes mellitus (T2DM), a worldwide chronic disease, is mainly caused by insufficient insulin production and places a huge burden on the health system. Gastrodia elata Blume (GE), a food of medicine-food homology, has been reported to have the ability to inhibit glycosidase activity, indicating its potential in the treatment of diabetes. However, the main pharmacological components of GE for the treatment of T2DM have not been fully clarified. Therefore, this study aims to clarify the pharmacological components changes of GE with different drying methods and the treatment of T2DM using HPLC, network pharmacology, molecular docking and experimental evaluations. The results showed that the GE samples processed by the steam-lyophilized method possessed the highest total content of the six marker components and the strongest antioxidant and α-glucosidase inhibitory abilities. Meanwhile, the six marker compounds had a total of 238 T2DM-related gene targets. Notably, these active compounds have good affinity for key gene targets associated with T2DM signaling pathways. In conclusion, this study revealed that different drying methods of GE affect the content of its major active compounds, antioxidant capacity, α-glucosidase inhibitory capacity and potential pharmacological effects on T2DM, indicating that it is a potential treatment of T2DM.

Enhancing human islet xenotransplant survival and function in diabetic immunocompetent mice through LRH-1/NR5A2 pharmacological activation

The intricate etiology of type 1 diabetes mellitus (T1D), characterized by harmful interactions between the immune system and insulin-producing beta cells, has hindered the development of effective therapies including human islet transplantation, which requires strong immunosuppressants that impair beta cell survival and function. As such alternative immunomodulating therapies are required for successful transplantation. The discovery that pharmacological activation of the nuclear receptor LRH-1/NR5A2 can reverse hyperglycemia in mouse models of T1D by altering, and not suppressing the autoimmune attack, prompted us to investigate whether LRH-1/NR5A2 activation could improve human islet function/survival after xenotransplantation in immunocompetent mice. Human islets were transplanted under the kidney capsule of streptozotocin (STZ)-induced diabetic mice, and treatment with BL001 (LRH-1/NR5A2 agonist) or vehicle was administered one week post-transplant. Our study, encompassing 3 independent experiments with 3 different islet donors, revealed that mice treated for 8 weeks with BL001 exhibited lower blood glucose levels correlating with improved mouse survival rates as compared to vehicle-treated controls. Human C-peptide was detectable in BL001-treated mice at both 4 and 8 weeks indicating functional islet beta cells. Accordingly, in mice treated with BL001 for 8 weeks, the beta cell mass was preserved, while a significant decrease in alpha cells was observed compared to mice treated with BL001 for only 4 weeks. In contrast, vehicle-treated mice exhibited a reduction in insulin-expressing cells at 8 weeks compared to those at 4 weeks. These results suggest that BL001 significantly enhances the survival, engraftment, and functionality of human islets in a STZ-induced diabetic mouse model.

Diabetic Macrophage Exosomal miR-381-3p Inhibits Epithelial Cell Autophagy Via NR5A2

PURPOSE

To explore the mechanism underlying autophagy disruption in gingival epithelial cells (GECs) in diabetic individuals.

METHODS AND MATERIALS

Bone marrow-derived macrophages (BMDMs) and GECs were extracted from C57/bl and db/db mice, the exosomes (Exo) were isolated from BMDMs. qRT‒PCR and Western blotting were performed to analyse gene expression. The AnimalTFDB database was used to identify relevant transcription factors, and miRNA sequencing was utilised to identify relevant miRNAs with the aid of the TargetScan/miRDB/miRWalk databases. A dual-luciferase assay was conducted to verify intermolecular targeting relationships.

RESULTS

Similar to BMDMs, BMDM-derived Exos disrupted autophagy and exerted proinflammatory effects in GEC cocultures, and ATG7 may play a vital role. AnimalTFDB database analysis and dual-luciferase assays indicated that NR5A2 is the most relevant transcription factor that regulates Atg7 expression. SiRNA-NR5A2 transfection blocked autophagy in GECs and exacerbated inflammation, whereas NR5A2 upregulation restored ATG7 expression and ameliorated ExoDM-mediated inflammation. MiRNA sequencing, with TargetScan/miRDB/miRWalk analyses and dual-luciferase assays, confirmed that miR-381-3p is the most relevant miRNA that targets NR5A2. MiR-381-3p mimic transfection blocked autophagy in GECs and exacerbated inflammation, while miR-381-3p inhibitor transfection restored ATG7 expression and attenuated ExoDM-mediated inflammation.

CONCLUSION

BMDM-derived Exos, which carry miR-381-3p, inhibit NR5A2 and disrupt autophagy in GECs, increasing periodontal inflammation in diabetes.

Liver receptor homolog-1: structures, related diseases, and drug discovery

Liver receptor homolog-1 (LRH-1), a member of the nuclear receptor superfamily, is a ligand-regulated transcription factor that plays crucial roles in metabolism, development, and immunity. Despite being classified as an 'orphan' receptor due to the ongoing debate surrounding its endogenous ligands, recent researches have demonstrated that LRH-1 can be modulated by various synthetic ligands. This highlights the potential of LRH-1 as an attractive drug target for the treatment of inflammation, metabolic disorders, and cancer. In this review, we provide an overview of the structural basis, functional activities, associated diseases, and advancements in therapeutic ligand research targeting LRH-1.

Uncovering the key pharmacodynamic material basis and possible molecular mechanism of Xiaoke formulation improve insulin resistant through a comprehensive investigation

ETHNOPHARMACOLOGICAL RELEVANCE

Xiaoke formulation (XKF) has been utilized in clinical practice for decades in China as a treatment option for mild to moderate type 2 diabetes. However, there is still a need for systematic research to uncover the key pharmacodynamic material basis and mechanism of XKF.

AIM OF THE STUDY

Aim of to investigate the distribution and metabolism of XKF in normal and insulin resistant (IR) mice were different, and elucidate its key pharmacodynamic material basis and mechanism of action.

MATERIALS AND METHODS

Ultra performance liquid chromatography/time of flight mass spectrometry technology was employed to investigate the differences in XKF absorption, distribution, and metabolism between normal and IR mice across blood, liver, feces, and urine samples. Further, network pharmacology was used to predict target proteins and their associated signaling pathways. Then, molecular docking was utilized to validate the activity of key pharmacodynamic components and targets. Finally, IR HepG2 cells were used to detect the glucose consumption under the action of key pharmacodynamic material basis. In addition, the expression of phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT) and phospho-protein kinase B (p-AKT) was determined using western blotting.

RESULTS

The study demonstrates significant distinctions in plasma and liver number and abundance of alkaloids, organic acids, flavonoids, iridoids and saponins between normal and IR mice when XKF was administered. Further analysis has shown that the representative components of XKF, including berberine, chlorogenic acid, calycosin, swertiamarin and astragaloside IV have significantly different metabolic pathways in plasma and liver. Prototypes and metabolites of these components were rarely detected in the urine and feces of mice. According to the network pharmacological analysis, these differential components are predicted to improve IR by targeting key factors such as SRC, JUN, HRAS, NOS3, FGF2, etc. Additionally, the signaling pathways involved in this process include PI3K-AKT pathway, GnRH signaling pathway, and T cell receptor signaling pathway. In addition, in vitro experiments indicate that berberine and its metabolites (berberine and demethyleneberine), chlorogenic acid and its metabolites (3-O-ferulic quinic acid and 5-O-ferulic quinic acid), calycosin and swertiamarin could improve IR in IR-HepG2 cells by elevating the expression of PI3K and AKT, leading to an increase in glucose consumption.

CONCLUSION

The key pharmacodynamic material basis of XKF, such as berberine and its metabolites (berberrubine and demethyleneberberine), chlorogenic acid and its metabolites (3-O-feruloylquinic acid and 5-O-feruloylquinic acid), calycosin and swertiamarin influence the glucose metabolism disorder of IR-HepG2 cells by regulating the PI3K/AKT signalling pathway, leading to an improvement in IR.

Liver receptor homolog-1 (NR5A2) orchestrates hepatic inflammation and TNF-induced cell death

The nuclear receptor liver receptor homolog-1 (LRH-1) has been shown to promote apoptosis resistance in various tissues and disease contexts; however, its role in liver cell death remains unexplored. Hepatocyte-specific deletion of LRH-1 causes mild steatosis and inflammation but unexpectedly shields female mice from tumor necrosis factor (TNF)-induced hepatocyte apoptosis and associated hepatitis. LRH-1-deficient hepatocytes show markedly attenuated estrogen receptor alpha and elevated nuclear factor κB (NF-κB) activity, while LRH-1 overexpression inhibits NF-κB activity. This inhibition relies on direct physical interaction of LRH-1's ligand-binding domain and the Rel homology domain of NF-κB subunit RelA. Mechanistically, increased transcription of anti-apoptotic NF-κB target genes and the proteasomal degradation of pro-apoptotic BCL-2 interacting mediator of cell death prevent mitochondrial apoptosis and ultimately protect mice from TNF-induced liver damage. Collectively, our study emphasizes LRH-1 as a critical, sex-dependent regulator of cell death and inflammation in the healthy and diseased liver.

LRH-1 activation alleviates diabetes-induced podocyte injury by promoting GLS2-mediated glutaminolysis

Alteration of metabolic phenotype in podocytes directly contributes to the development of albuminuria and renal injury in conditions of diabetic kidney disease (DKD). This study aimed to identify and evaluate liver receptor homologue-1 (LRH-1) as a possible therapeutic target that alleviates glutamine (Gln) metabolism disorders and mitigates podocyte injury in DKD. Metabolomic and transcriptomic analyses were performed to characterize amino acid metabolism changes in the glomeruli of diabetic mice. Next, Western blotting, immunohistochemistry assays, and immunofluorescence staining were used to detect the expression of different genes in vitro and in vivo. Furthermore, Gln and glutamate (Glu) content as well as ATP generation were examined. A decrease in LRH-1 and glutaminase 2 (GLS2) expression was detected in diabetic podocytes. Conversely, the administration of LRH-1 agonist (DLPC) upregulated the expression of GLS2 and promoted glutaminolysis, with an improvement in mitochondrial dysfunction and less apoptosis in podocytes compared to those in vehicle-treated db/db mice. Our study indicates the essential role of LRH-1 in governing the Gln metabolism of podocytes, targeting LRH-1 could restore podocytes from diabetes-induced disturbed glutaminolysis in mitochondria.

The PTGS2/COX2-PGE2 signaling cascade in inflammation: Pro or anti? A case study with type 1 diabetes mellitus

Prostaglandins are lipid mediators involved in physiological processes, such as constriction or dilation of blood vessels, but also pathophysiological processes, which include inflammation, pain and fever. They are produced by almost all cell types in the organism by activation of Prostaglandin endoperoxide synthases/Cyclooxygenases. The inducible Prostaglandin Endoperoxide Synthase 2/Cyclooxygenase 2 (PTGS2/COX2) plays an important role in pathologies associated with inflammatory signaling. The main product derived from PTGS2/COX2 expression and activation is Prostaglandin E2 (PGE2), which promotes a wide variety of tissue-specific effects, pending environmental inputs. One of the major sources of PGE2 are infiltrating inflammatory cells - the production of this molecule increases drastically in damaged tissues. Immune infiltration is a hallmark of type 1 diabetes mellitus, a multifactorial disease that leads to autoimmune-mediated pancreatic beta cell destruction. Controversial effects for the PTGS2/COX2-PGE2 signaling cascade in pancreatic islet cells subjected to diabetogenic conditions have been reported, allocating PGE2 as both, cause and consequence of inflammation. Herein, we review the main effects of this molecular pathway in a tissue-specific manner, with a special emphasis on beta cell mass protection/destruction and its potential role in the prevention or development of T1DM. We also discuss strategies to target this pathway for future therapies.

Steroidogenic factor 1 protects mice from obesity-induced glucose intolerance via improving glucose-stimulated insulin secretion by beta cells

As a potential druggable nuclear receptor, steroidogenic factor 1 (SF1) regulates obesity and insulin resistance in the ventromedial hypothalamic nucleus. Herein, we sought to demonstrate its expression and functions in islets in the development of obesity-induced diabetes. SF1 was barely detected in the beta cells of lean mice but highly expressed in those of non-diabetic obese mice, while decreased in diabetic ones. Conditional deletion of SF1 in beta cells predisposed diet-induced obese (DIO) mice to glucose intolerance by perturbing glucose-stimulated insulin secretion (GSIS). Consistently, forced expression of SF1 restored favorable glucose homeostasis in DIO and db/db mice by improving GSIS. In isolated islets and MIN6, overexpression of SF1 also potentiated GSIS, mediated by improvement of mitochondrial ATP production. The underlying mechanisms may involve oxidative phosphorylation and lipid metabolism. Collectively, SF1 in beta cell preserves GSIS to promote beta-cell adaptation to obesity and hence is a potential therapeutic target for obesity-induced diabetes.

NR5A2 as a potential target for exercise to improve metabolic syndrome

BACKGROUND

Metabolic syndrome is a syndrome of a variety of metabolic disorders. Exercise is beneficial to the human body. However, the association of NR5A2 and exercise with metabolic syndrome remains unclear.

METHODS

Download the GSE10540 and GSE12385 from GEO database. Bioinformatics analysis was used to screen the hub molecular of the metabolic syndrome. Forty 3-week-old C57BL/6J male mice were used in this study. The mean body weight was (17.5 ± 2.1) g. After 10 days of adaptive feeding, they were randomly divided into 4 groups according to the random number table method: Model + Exercise (n = 10), Model (n = 10), Model/NR5A2-OE (n = 10), Model/NR5A2-KO (n = 10). Western Blotting was performed to detect the expression of hub genes and signaling pathway.

RESULTS

There were 349 DEGs in GSE10540 and 49 DEGs in GSE12385. 10 core genes were obtained. GO showed that differentially expressed genes were mainly enriched in vascular morphogenesis, contractile fiber fraction, chemotaxis, and MAPK cascade regulation. KEGG showed that MAPK signaling pathway was a significant section in the metabolic syndrome. PIK3R2, STRA8, FLT1, DMRT1, FGF22, NR5A2, and FLT were up-regulated and PRDM14, POU5F1, and KDR were down-regulated in metabolic syndrome after exercise.

CONCLUSION

The expression of NR5A2 is down-regulated in metabolic syndrome, and exercise can increase the expression level of NR5A2. NR5A2 might be used as a potential target for exercise to improve metabolic syndrome.