Roles of distinct nuclear receptors in diabetic cardiomyopathy.

Diabetes mellitus induces a pathophysiological disorder known as diabetic cardiomyopathy and may eventually cause heart failure. Diabetic cardiomyopathy is manifested with systolic and diastolic contractile dysfunction along with alterations in unique cardiomyocyte proteins and diminished cardiomyocyte contraction. Multiple mechanisms contribute to the pathology of diabetic cardiomyopathy, mainly including abnormal insulin metabolism, hyperglycemia, glycotoxicity, cardiac lipotoxicity, endoplasmic reticulum stress, oxidative stress, mitochondrial dysfunction, calcium treatment damage, programmed myocardial cell death, improper Renin-Angiotensin-Aldosterone System activation, maladaptive immune modulation, coronary artery endothelial dysfunction, exocrine dysfunction, etc. There is an urgent need to investigate the exact pathogenesis of diabetic cardiomyopathy and improve the diagnosis and treatment of this disease. The nuclear receptor superfamily comprises a group of transcription factors, such as liver X receptor, retinoid X receptor, retinoic acid-related orphan receptor-α, retinoid receptor, vitamin D receptor, mineralocorticoid receptor, estrogen-related receptor, peroxisome proliferatoractivated receptor, nuclear receptor subfamily 4 group A 1(NR4A1), etc. Various studies have reported that nuclear receptors play a crucial role in cardiovascular diseases. A recently conducted work highlighted the function of the nuclear receptor superfamily in the realm of metabolic diseases and their associated complications. This review summarized the available information on several important nuclear receptors in the pathophysiology of diabetic cardiomyopathy and discussed future perspectives on the application of nuclear receptors as targets for diabetic cardiomyopathy treatment.

Dihydromyricetin regulates RIPK3-CaMKII to prevent necroptosis in high glucose-stimulated cardiomyocytes.

Background: Diabetic cardiomyopathy is one common cardiovascular complication without effective treatments. Dihydromyricetin (DHY), a natural dihydroflavonol compound extracted from Ampelopsis grossedentata, possesses versatile pharmacologically important effects. In our current research, we planned to evaluate the impact and probable DHY mechanisms in high glucose (HG)-induced cardiomyocytes. Methods: Primary cardiomyocytes were pretreated with different concentrations of DHY (0, 20, 40, 80, 160, and 320 µM) for various time (0, 1, 2, 4, 12, and 24 h). They were then stimulated for 48 h with 5.5 mmol/L normal glucose (NG) and 33.3 mmol/L high glucose (HG). Cell viability, adenosine-triphosphate (ATP) levels, and lactate dehydrogenase (LDH) release of cardiomyocytes were detected. JC-1 staining was employed to measure the mitochondrial membrane potential. MitoSOX staining and dihydroethidium (DHE) staining were applied to evaluate the oxidative stress levels. TDT mediated dUTP nick end labeling (TUNEL) was used to measure apoptotic levels. Expressions of calcium/calmodulin-dependent protein kinase II (CaMKII), phospholamban (PLB), optic atrophy 1 (OPA1), dynamin-related protein 1 (DRP1), caspase 3, mixed kinase lineage domain like protein (MLKL), receptor interacting protein kinase 3 (RIPK3), and receptor interacting protein kinase 1 (RIPK1) were detected by immunofluorescence and/or Western blot. Results: DHY improved cell viability, enhanced ATP level, and decreased LDH content in HG-stimulated cardiomyocytes, suggesting DHY attenuating cell injury. DHY reduced number of TUNEL positive cells, inhibited RIPK3 and cleaved-caspase 3 expression, implying DHY alleviated necroptosis in HG-stimulated cardiomyocytes. DHY diminished JC-1 monomers, DHE and MitoSOX fluorescence intensity as well as DRP1 expression but increased JC-1 aggregates intensity and OPA1 expression, indicating that DHY attenuated oxidative stress in HG-stimulated cardiomyocytes. DHY also attenuated CaMKII activity by suppressed PLB phosphorylation and inhibited CaMKII oxidation in HG-stimulated cardiomyocytes. Conclusions: HG-induced cardiomyocytes injury was alleviated wherein DHY attenuated necroptosis, repressed ROS production, and inhibited CaMKII oxidation, suggesting that DHY may serve as potential agent to prevent and treat diabetic cardiomyopathy.

Uncovering the effect and mechanism of Jiawei Xiaoyao Wan in treating breast cancer complicated with depression based on network pharmacology and experimental analysis.

BACKGROUND: Depression is a clinically common co-morbidity in breast cancer cases that brings negative outcomes on quality of life and potentially survival. Jiawei Xiaoyao Wan (JXW) is widely used in treating breast cancer and depressive disorder, but its potential pharmacological mechanisms remain elusive. PURPOSE: We aimed to explore the dual therapeutic effects and mechanisms of JXW acting on breast cancer complicated with depression (BCCD) by network pharmacology and in vivo experimental verification. METHODS: The chemical constituents of JXW were characterized using liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (LC-Q-TOF/MS). The targets related to constituents of JXW were predicted by the TCMSP and Swiss Target Prediction databases, and targets of breast cancer and depression were screened by the GeneCards and OMIM databases. Gene Ontology annotation and KEGG enrichment analysis were performed with the DAVID database. Ultimately, a BCCD mouse model induced by chronic restraint stress (CRS) was used to explore therapeutic effects and mechanisms of JXW against BCCD. The efficacy of JXW in the treatment of BCCD was evaluated based on behavioral tests, tumor volume and weight, and pathological examination. Additionally, the underlying mechanisms were explored by measuring the levels of neurotransmitter and inflammatory factors, as well as detecting the expression of genes or proteins associated with candidate targets and the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway through RT-PCR, western blotting, and immunohistochemistry. RESULTS: Totals of 108 components were identified in JXW using LC-Q-TOF/MS. By network pharmacology analysis, 714 compound targets of JXW, 2114 breast cancer targets, 1122 depression targets, and 98 overlapping proteins were obtained. PPI network and KEGG analysis implied that TP53, ESR1, VEGFA, AKT1, IL6, TNF, EGFR and the JAK/STAT pathway might be the potential targets of JXW in treating BCCD. In vivo experiments indicated that JXW significantly ameliorated depressive symptoms and tumor progression in BCCD mice. Further mechanistic studies showed that JXW could reduce the levels of inflammatory factors, increase 5-HT level, and regulate mRNA expression levels of TP53, VEGFA, AKT1, IL6, TNF, and EGFR targets. Moreover, the expression levels of proteins related to the JAK2/STAT3 signaling pathway in BCCD mice were effectively regulated by JXW. CONCLUSION: JXW exerts dual therapeutic effects in a BCCD mouse via multiple targets. The underlying mechanisms might be associated with regulating the levels of neurotransmitter and inflammatory factors; more importantly, the JAK2/STAT3 pathway plays a significant role in this process.

Different types of cell death in diabetic endothelial dysfunction.

Diabetes mellitus is a metabolic disease caused by disorders of insulin secretion and utilization. Long-term hyperglycemia, insulin resistance, and disorders of glucose and lipid metabolism cause vascular endothelial cell damage. Endothelial dysfunction is a key feature of diabetic vascular complications such as diabetic nephropathy, retinopathy, neuropathy, and atherosclerosis. Importantly, cell death is thought to be a key factor contributing to vascular endothelial injury. Morphologically, cell death can be divided into three forms: type I apoptosis, type II autophagy, and type III necrosis. According to the difference in function, cell death can be divided into accidental cell death (ACD) and regulated cell death (RCD). RCD is a controlled process involving numerous proteins and precise signaling cascades. Multiple subroutines covered by RCD may be involved in diabetic endothelial dysfunction, including apoptosis, autophagy, necroptosis, pyroptosis, entosis, ferroptosis, ferroautophagy, parthanatos, netotic cell death, lysosome-dependent cell death, alkaliptosis, oxeiptosis, cuproptosis, and PANoptosis. This article briefly reviews the mechanism and significance of cell death associated with diabetic endothelial dysfunction, which will help deepen the understanding of diabetic endothelial cell death and provide new therapeutic ideas.

Hydrogen sulfide promoted retinoic acid-related orphan receptor α transcription to alleviate diabetic cardiomyopathy.

Diabetic cardiomyopathy (DCM) is one serious and common complication in diabetes without effective treatments. Hydrogen sulfide (H2S) fights against a variety of cardiovascular diseases including DCM. Retinoic acid-related orphan receptor α (RORα) has protective effects on cardiovascular system. However, whether RORα mediates the protective effect of H2S against DCM remains unknown. The present research was to explore the roles and mechanisms of RORα in H2S against DCM. The study demonstrated that H2S donor sodium hydrosulfide (NaHS) alleviated cell injury but enhanced RORα expression in high glucose (HG)-stimulated cardiomyocytes. However, NaHS no longer had the protective effect on attenuating cell damage and oxidative stress, improving mitochondrial membrane potential, inhibiting necroptosis and enhanced signal transducer and activator of transcription 3 (STAT3) Ser727 phosphorylation in HG-stimulated cardiomyocytes after RORα siRNA transfection. Moreover, NaHS improved cardiac function, attenuated myocardial hypertrophy and fibrosis, alleviated oxidative stress, inhibited necroptosis, but increased STAT3 phosphorylation in wild type (WT) mice but not in RORα knockout mice (a spontaneous staggerer mice, sg/sg mice) with diabetes. Additionally, NaHS increased RORα promoter activity in cardiomyocytes with HG stimulation, which was related to the binding sites of E2F transcription factor 1 (E2F1) in the upstream region of RORα promoter. NaHS enhanced E2F1 expression and increased the binding of E2F1 to RORα promoter in cardiomyocytes with HG stimulation. In sum, H2S promoted RORα transcription via E2F1 to alleviate necroptosis and protect against DCM. It is helpful to propose a novel therapeutic implication for DCM.