Project description:Astragaloside IV (ASIV) is the main active component of Astragalus, and can ameliorate cardiomyocyte hypertrophy, apoptosis and fibrosis. In this experiment, we studied how ASIV reduces the cardiotoxicity caused by adriamycin and protects the heart. To this end, rats were randomly divided into the control, ADR, ADR + ASIV and ASIV groups (n = 6). Echocardiography was used to observe cardiac function, HE staining was used to observe myocardial injury, TUNEL staining was used to observe myocardial cell apoptosis, and immunofluorescence and Western blotting was used to observe relevant proteins expression. Experiments have shown that adriamycin can damage heart function in rats, and increase the cell apoptosis index, autophagy level and oxidative stress level. Further results showed that ADR can inhibit the PI3K/Akt pathway. ASIV treatment can significantly improve the cardiac function of rats treated with ADR and regulate autophagy, oxidative stress and apoptosis. Our findings indicate that ASIV may reduce the heart damage caused by adriamycin by activating the PI3K/Akt pathway.
Project description:The nuclear receptor Chicken Ovalbumin Upstream Promoter-Transcription Factor II (COUP-TFII) is an important coordinator of glucose homeostasis through its function in different organs such as the endocrine pancreas, adipose tissue, skeletal muscle, and liver. Recently we have demonstrated that COUP-TFII expression in the hypothalamus is restricted to a subpopulation of neurons expressing the steroidogenic factor 1 transcription factor, known to play a crucial role in glucose homeostasis. To understand the functional significance of COUP-TFII expression in the steroidogenic factor 1 neurons, we generated hypothalamic ventromedial nucleus-specific COUP-TFII KO mice using the cyclization recombination/locus of X-overP1 technology. The heterozygous mutant mice display insulin hypersensitivity and a leaner phenotype associated with increased energy expenditure and similar food intake. These mutant mice also present a defective counterregulation to hypoglycemia with altered glucagon secretion. Moreover, the mutant mice are more likely to develop hypoglycemia-associated autonomic failure in response to recurrent hypoglycemic or glucopenic events. Therefore, COUP-TFII expression levels in the ventromedial nucleus are keys in the ability to resist the onset of hypoglycemia-associated autonomic failure.
Project description:The nuclear receptors (NRs) belong to a vast family of evolutionary conserved proteins acting as ligand-activated transcription factors. Functionally, NRs are essential in embryogenesis and organogenesis and in adulthood they are involved in almost every physiological and pathological process. Our knowledge of NRs action has greatly improved in recent years, demonstrating that both their expression and activity are tightly regulated by a network of signaling pathways, miRNA and reciprocal interactions. The Chicken Ovalbumin Upstream Promoter Transcription Factor II (COUP-TFII, NR2F2) is a NR classified as an orphan due to the lack of a known natural ligand. Although its expression peaks during development, and then decreases considerably, in adult tissues, COUP-TFII is an important regulator of differentiation and it is variably implicated in tissues homeostasis. As such, alterations of its expression or its transcriptional activity have been studied and linked to a spectrum of diseases in organs and tissues of different origins. Indeed, an altered COUP-TFII expression and activity may cause infertility, abnormality in the vascular system and metabolic diseases like diabetes. Moreover, COUP-TFII is actively investigated in cancer research but its role in tumor progression is yet to be fully understood. In this review, we summarize the current understanding of COUP-TFII in healthy and pathological conditions, proposing an updated and critical view of the many functions of this NR.
Project description:The inflammatory process plays a significant role in the pathophysiology of Alzheimer's disease (AD). Anti-neuroinflammatory cascade is now considered an important measure for AD treatment. Astragaloside IV (AS-IV), a saponin of Astragali radix, has shown significant anti-inflammatory properties and protective effects against neurodegenerative diseases. However, the mechanisms of AS-IV in treating Alzheimer's disease (AD) have not been fully determined. The experiment research was carried out to comprehensively confirm the beneficial effects and underlying molecular mechanisms of AS-IV to AD. In this research, BV-2 cells were cultured in vitro and treated by AS-IV under the stimulation of LPS, qRT-PCR was adopted to analyze the mRNA expression level of inflammatory factors. Western-blot was carried out to analyze the phosphorylation level of NF-κB signaling pathway. 5xFAD mice were administrated AS-IV mixed in the diet for 3 months. Behavioral experiments were adopted to analyze learning and memory abilities. Immunohistochemical staining was adopted to observe the proliferation of microglias and the accumulation of Aβ plaques. AS-IV cut down the mRNA expression of IL-1β, COX-2, iNOS and TNF-α in LPS-stimulated BV-2 cells by suppressing the phosphorylation of IκB and p65, and inhibited the phosphorylated p65 from entering the nucleus. AS-IV increased the frequency of recognizing new objects in the novel object recognition test, shortened the escape latency, raised the number of crossing platform in the Morris water maze, inhibited the hyperplasia of microglias, and reduced the production of senile plaques in 5xFAD mice. In brief, AS-IV ameliorates learning and memory impairment by relieving the intensity of neuroinflammatory response in AD. Therefore, AS-IV is very promising to be a herbal medicine for AD treatment.
Project description:BackgroundAstragaloside IV (As-IV) and Tanshinone IIA (Ta-IIA) are the main ingredients of traditional Chinese medicinal Astragalus membranaceus (Fisch.) Bunge and Salvia miltiorrhiza Bunge, respectively, both of which have been employed in the treatment of cardiovascular diseases. Nevertheless, the efficacy of the combination (Co) of Ta-IIA and As-IV for cardiovascular diseases remain unclear and warrant further investigation. This study aimed to investigate the efficacy and the underlying molecular mechanism of Co in treating myocardial ischemia-reperfusion injury (MIRI).MethodsIn order to assess the efficacy of Co, an in vivo MIRI mouse model was created by temporarily blocking the coronary arteries for 30 min and then releasing the blockage. Parameters such as blood myocardial enzymes, infarct size, and ventricular function were measured. Additionally, in vitro experiments were conducted using HL1 cells in both hypoxia-reoxygenation model and oxidative stress models. The apoptosis rate, expression levels of apoptosis-related proteins, oxidative stress indexes, and release of inflammatory factors were detected. Furthermore, molecular docking was applied to examine the binding properties of Ta-IIA and As-IV to STING, and western blotting was performed to analyze protein expression of the STING pathway. Additionally, the protective effect of Ta-IIA, As-IV and Co via inhibiting STING was further confirmed in models of knockdown STING by siRNA and adding STING agonist.ResultsBoth in vitro and in vivo data demonstrated that, compared to Ta-IIA or As-IV alone, the Co exhibited superior efficacy in reducing the area of myocardial infarction, lowering myocardial enzyme levels, and promoting the recovery of myocardial contractility. Furthermore, the Co showed more potent anti-apoptosis, antioxidant, and anti-inflammation effects. Additionally, the Co enhanced the inhibitory effects of Ta-IIA and As-IV on STING phosphorylation and the activation of STING signaling pathway. However, the administration of a STING agonist attenuated the protective effects of the Co, Ta-IIA, and As-IV by compromising their anti-apoptotic, antioxidant, and anti-inflammatory effects in MIRI.ConclusionCompared to the individual administration of Ta-IIA or As-IV, the combined treatment demonstrated more potent ability in inhibiting apoptosis, oxidative stress, inflammation, and the STING signaling pathway in the context of MIRI, indicating a more powerful protective effect against MIRI.
Project description:BackgroundSunitinib, a multitargeted tyrosine-kinase inhibitor, which is approved by both US and European Commission regulatory agencies for clinical use, extends survival of patients with metastatic renal-cell carcinoma and gastrointestinal stromal tumours, but concerns have arisen about its cardiac safety. We therefore assessed the cardiovascular risk associated with sunitinib in patients with metastatic gastrointestinal stromal tumours.MethodsWe retrospectively reviewed all cardiovascular events in 75 patients with imatinib-resistant, metastatic, gastrointestinal stromal tumours who had been enrolled in a phase I/II trial investigating the efficacy of sunitinib. The composite cardiovascular endpoint was cardiac death, myocardial infarction, and congestive heart failure. We also examined sunitinib's effects on left ventricular ejection fraction (LVEF) and blood pressure. We investigated potential mechanisms of sunitinib-associated cardiac effects by studies in isolated rat cardiomyocytes and in mice.FindingsEight of 75 (11%) patients given repeating cycles of sunitinib in the phase I/II trial had a cardiovascular event, with congestive heart failure recorded in six of 75 (8%). Ten of 36 (28%) patients treated at the approved sunitinib dose had absolute LVEF reductions in ejection fraction (EF) of at least 10%, and seven of 36 (19%) had LVEF reductions of 15 EF% or more. Sunitinib induced increases in mean systolic and diastolic blood pressure, and 35 of 75 (47%) individuals developed hypertension (>150/100 mm Hg). Congestive heart failure and left ventricular dysfunction generally responded to sunitinib being withheld and institution of medical management. Sunitinib caused mitochondrial injury and cardiomyocyte apoptosis in mice and in cultured rat cardiomyocytes.InterpretationLeft ventricular dysfunction might be due, in part, to direct cardiomyocyte toxicity, exacerbated by hypertension. Patients treated with sunitinib should be closely monitored for hypertension and LVEF reduction, especially those with a history of coronary artery disease or cardiac risk factors.
Project description:Duchenne muscular dystrophy (DMD) is a severe and progressive muscle-wasting disease caused by mutations in the dystrophin gene. Although dystrophin deficiency in myofiber triggers the disease's pathological changes, the degree of satellite cell (SC) dysfunction defines disease progression. Here, we have identified chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII) hyperactivity as a contributing factor underlying muscular dystrophy in a dystrophin-deficient murine model of DMD. Ectopic expression of COUP-TFII in murine SCs led to Duchenne-like dystrophy in the muscles of control animals and exacerbated degenerative myopathies in dystrophin-deficient mice. COUP-TFII-overexpressing mice exhibited regenerative failure that was attributed to deficient SC proliferation and myoblast fusion. Mechanistically, we determined that COUP-TFII coordinated a regenerative program through combined regulation of multiple promyogenic factors. Furthermore, inhibition of COUP-TFII preserved SC function and counteracted the muscle weakness associated with Duchenne-like dystrophy in the murine model, suggesting that targeting COUP-TFII is a potential treatment for DMD. Together, our findings reveal a regulatory role of COUP-TFII in the development of muscular dystrophy and open up a potential therapeutic opportunity for managing disease progression in patients with DMD.
Project description:The development of the progenitor zones in the pallium, lateral ganglionic eminence (LGE) and medial ganglionic eminence (MGE) in the subpallium has been well studied; however, so far the role of the caudal ganglionic eminence (CGE), a posterior subpallial domain, in telencephalon patterning remains poorly understood. COUP-TFII, an orphan nuclear receptor, is preferentially expressed in the CGE. We generated COUP-TFII mouse mutants, using Rx-Cre (RxCre;COUP-TFII(F/F)), to study its function in telencephalon development. In these mutants, we found severe defects in the formation of the amygdala complex, including the lateral (LA), basolateral (BLA) and basomedial (BMA) amygdala nuclei. Molecular analysis provided evidence that the migration of CGE-derived Pax6(+) cells failed to settle into the BMA nucleus, owing to reduced expression of neuropilin 1 (Nrp1) and Nrp2, two semaphorin receptors that regulate neuronal cell migration and axon guidance. Our ChIP assays revealed that Nrp1 and Nrp2 genes are the direct targets of COUP-TFII in the telencephalon in vivo. Furthermore, our results showed that the coordinated development between the CGE originated subpallial population (Pax6(+) cells) and pallial populations (Tbr1(+) and Lhx2(+) cells) was essential for patterning the amygdala assembly. Our study presented novel genetic evidence that the caudal ganglionic eminence, a distinct subpallial progenitor zone, contributes cells to the basal telencephalon, such as the BMA nucleus.
Project description:Chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII) has been shown to inhibit myogenesis and skeletal muscle metabolism in vitro. However, its precise role and in vivo function in muscle development has yet to be clearly defined. COUP-TFII protein expression level is high in undifferentiated progenitors and gradually declines during differentiation, raising an important question of whether downregulation of COUP-TFII expression is required for proper muscle cell differentiation. In this study, we generated a mouse model ectopically expressing COUP-TFII in myogenic precursors to maintain COUP-TFII activity during myogenesis and found that elevated COUP-TFII activity resulted in inefficient skeletal muscle development. Using in vitro cell culture and in vivo mouse models, we showed that COUP-TFII hinders myogenic development by repressing myoblast fusion. Mechanistically, the inefficient muscle cell fusion correlates well with the transcriptional repression of Npnt, Itgb1D and Cav3, genes important for cell-cell fusion. We further demonstrated that COUP-TFII also reduces the activation of focal adhesion kinase (FAK), an integrin downstream regulator which is essential for fusion process. Collectively, our studies highlight the importance of down-regulation of COUP-TFII signaling to allow for the induction of factors crucial for myoblast fusion.
Project description:Chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII; NR2F2) is an orphan nuclear receptor involved in cell-fate specification, organogenesis, angiogenesis, and metabolism. Ablation of COUP-TFII in the mouse uterus causes infertility due to defects in embryo attachment and impaired uterine stromal cell decidualization. Although the function of COUP-TFII in uterine decidualization has been described in mice, its role in the human uterus remains unknown. We observed that, as in mice, COUP-TFII is robustly expressed in the endometrial stroma of healthy women, and its expression is reduced in the ectopic lesions of women with endometriosis. To interrogate the role of COUP-TFII in human endometrial function, we used a small interfering RNA-mediated loss of function approach in primary human endometrial stromal cells. Attenuation of COUP-TFII expression did not completely block decidualization; rather it had a selective effect on gene expression. To better elucidate the role of COUP-TFII in endometrial stroma cell biology, the COUP-TFII transcriptome was defined by pairing microarray comparison with chromatin immunoprecipitation followed by deep sequencing. Gene ontology analysis demonstrates that COUP-TFII regulates a subset of genes in endometrial stroma cell decidualization such as those involved in cell adhesion, angiogenesis, and inflammation. Importantly this analysis shows that COUP-TFII plays a role in controlling the expression of inflammatory cytokines. The determination that COUP-TFII plays a role in inflammation may add insight into the role of COUP-TFII in embryo implantation and in endometrial diseases such as endometriosis.