Angiotensin IV attenuates diabetic cardiomyopathy via suppressing FoxO1-induced excessive autophagy, apoptosis and fibrosis

Peritoneal protein clearance, fluid overload, and cardiovascular events in patients undergoing peritoneal dialysis: a prospective cohort study

BACKGROUND

The relationship among higher peritoneal protein clearance (PPCl), fluid overload, and increased risk of cardiovascular (CV) events has not been well clarified in peritoneal dialysis (PD) patients. We aimed to examine their associations in a prospective cohort study.

METHODS

Eligible patients were enrolled from a single center, and PPCl was calculated based on the daily dialysate protein loss corrected for serum albumin. Fluid overload was defined as extracellular water (ECW)/total body water (TBW) ≥0.400 measured by bioelectrical impedance analysis (BIA). The primary outcome was CV events.

RESULTS

In total, 351 patients were included in this study. After adjustment for confounders, every 5 mL/day increase in PPCl was independently associated with a 27% higher risk of fluid overload determined by BIA (odds ratio: 1.27, 95% confidence interval (CI): 1.17-1.37). After a median follow-up of 46.8 months, 90 patients (25.6%) experienced CV events. In competing risk models adjusted for confounders, both fluid overload and every 5 mL/day increase in PPCl were independently associated with 70% (subdistribution hazard ratio (SHR):1.70, 95%CI: 1.06-2.74) and 9% (SHR: 1.09, 95%CI: 1.04-1.14) increased risk of CV events, respectively. When fluid overload and PPCl were added simultaneously to the models, PPCl remained a strong independent predictor (SHR: 1.07; 95%CI: 1.03-1.13).

CONCLUSIONS

Higher PPCl was independently associated with fluid overload determined by BIA in PD patients. Moreover, higher PPCl was independently associated with an increased risk of CV events.

Reprogramming of lipids and amino acids metabolism is an early event in myocardium of type 1 diabetic rhesus monkeys

Diabetic cardiomyopathy (DC) refers to the abnormal myocardial structure and performance induced by diabetes. Although numerous studies have been carried out, the pathophysiological mechanisms of cardiovascular disorders during diabetes have not been fully clarified. Here, we compared the cardiomyopathy of healthy rhesus monkeys and rhesus monkeys with a history of streptozocin induced type 1 diabetes (T1D) over 7 years. Through comparing the cardiac function using echocardiography, and detecting the serum biochemical indexes, and changes of left ventricle (LV), we found that decreased systolic function, higher blood glycosylated hemoglobin A1c (HbA1C) level, hyperglycemia, and hyperlipidemia were early events in diabetic rhesus monkeys. In addition, cardiac histological analysis showed mildly fibrosis and early myocardial hypertrophy, as evidenced by increased Sirius red stained area and cross-sectional area of left ventricle. Transcriptome results revealed that the nutrients metabolism and extracellular matrix related pathways were markedly changed in the left ventricle of diabetic monkeys. Targeted metabolomics and targeted lipid metabolomics further revealed that disturbed amino acid metabolism and lipid accumulation in the LV of diabetic monkeys manifested by accumulated branched chain amino acids (BCAAs) and triglycerides (TAGs), and reduced contents of sphingolipids, glycerophospholipids, cholesteryl esters and carnitines. In conclusion, we reported here for the first time that diabetes lasting for more than 7 years leads to some early pathological changes of myocardium in rhesus monkeys. The cardiac function is mildly compromised and the reprogramming of lipids and amino acids metabolism might play important roles in the progression of DC.

TERT/FOXO1 signaling promotes islet β-cell dysfunction in type 2 diabetes mellitus by regulating ATG9A-mediated autophagy

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a severe global health problem that causes prolonged disease exposure and an elevated risk for chronic complications, posing a substantial health burden. Although therapies, such as GLP-1 receptor agonists and SGLT2 inhibitors, have been successfully developed, new therapeutic options are still expected to offer better blood glucose control and decrease complications.

AIM

To elucidate the mechanism by which TERT/FOXO1 affects high glucose (HG)-induced dysfunction in islet β-cells via the regulation of ATG9A-mediated autophagy.

METHODS

High-fat diet (HFD)-fed/streptozotocin (STZ)-treated mice or HG-treated MIN6 cells were used to establish T2DM models. Fasting blood glucose (FBG) and insulin levels in mice, as well as morphological changes in islet tissues, were assessed. Cell proliferation and the apoptosis rate were measured via EdU assays and flow cytometry, respectively. The expression levels of TERT, FOXO1, ATG9A and autophagy-related proteins (LC3B, p62) were analyzed via western blotting. The relationship between FOXO1 and ATG9A was assessed using dual-luciferase reporter gene assays and ChIP assays.

RESULTS

T2DM modeling in HFD-fed/STZ-treated mice and HG-treated MIN6 cells led to elevated TERT and FOXO1 expression and reduced ATG9A expression. Mice with T2DM were found to have decreased body weight, worsened morphology, elevated FBG and suppressed insulin levels. HG-treated MIN6 cells presented decreased viability and LC3B expression, in addition to increased p62 expression and apoptosis rates. FOXO1 knockdown both in vitro and in vivo protected mice and cells against islet β-cell dysfunction via the activation of autophagy. The molecular mechanism involved the suppression of ATG9A expression by TERT through FOXO1 transcription activation.

CONCLUSION

Our results suggested that TERT/FOXO1 inhibits ATG9A expression to decrease islet β-cell function in T2DM.

Paeonol regulates autophagy through the PI3K-AKT-mTOR signaling pathway to inhibit apoptosis of osteocytes

Osteoporosis is the most common complication of glucocorticoids and predisposes to fractures. Excessive apoptosis of osteocytes is the pathological feature of glucocorticoid-induced osteoporosis. Paeonol, an effective component of Traditional Chinese Medicine Cortex Moutan, known for its anti-inflammatory and analgesic properties, has a long clinical application history. However, the regulatory effect of paeonol on the fate of osteocytes under excessive glucocorticoid remains unclear. The present study aimed to investigate the effect of paeonol against osteocyte death and osteoporosis induced by glucocorticoid and to explore the underlying mechanisms. We found that paeonol not only improved the low proliferation rate of osteocytes induced by dexamethasone but also weakened the dexamethasone-induced apoptosis of osteocytes by stimulating cytoprotective autophagy. Subsequently, proteomic sequencing identified the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) - protein kinase B (AKT) signaling pathway as the potential target of paeonol in attenuating dexamethasone-induced osteocyte injury, and the PI3K activator and inhibitor confirmed this hypothesis. In vivo, paeonol alleviated glucocorticoid-induced osteoporosis, promoted autophagy and inhibited apoptosis of osteocytes by regulating PI3K phosphorylation. In brief, paeonol protects osteocytes from dexamethasone-derived apoptosis by increasing protective autophagy, further inhibiting osteoporosis. Its autophagy-promoting effect was associated with inhibition of PI3K-AKT-mechanistic target of rapamycin (mTOR) of osteocytes.

The role of the farnesoid X receptor in diabetes and its complications

Diabetes is a metabolic disease in which tissues and organs are exposed to a hyperglycemic environment for a prolonged period. Long-term hyperglycemia can cause dysfunction of multiple organs and tissues in the body, leading to diabetic complications such as diabetic cardiomyopathy and diabetic nephropathy. Diabetes and its complications have become one of the key issues that seriously threaten the health of people worldwide. Farnesoid X receptor (FXR), as a metabolic regulator, has multiple functions in regulating insulin synthesis and secretion, insulin resistance, lipid metabolism, oxidative stress, inflammatory response, and fibrosis. It plays a key role in alleviating diabetes and its complications. In this review, we discuss the latest findings of FXR related to diabetes and its complications, focusing on its role in diabetes, diabetic nephropathy, diabetic cardiomyopathy, and diabetic liver injury. The aim is to better understand the role of FXR in diabetes and its complications and to provide new perspectives on the treatment of diabetes and its complications.

P2X7 Receptor Facilitates Cardiomyocyte Autophagy After Myocardial Infarction via Nox4/PERK/ATF4 Signaling Pathway

Myocardial infarction (MI) represents a critical cardiovascular emergency, standing as a leading cause of global mortality. ATP, a typical damage-associated molecular pattern, is stored in cells at high concentrations. Upon cellular injury, hypoxia, or necrosis, substantial quantities of ATP efflux into the extracellular space, activating P2X7 receptors, thereby initiating multiple signaling cascades. In vivo studies demonstrated coordinated upregulation of P2X7 and autophagy-related proteins in the infarcted border zone. Transcriptome sequencing revealed Nox4 overexpression in the myocardial tissue post-infarction; furthermore, administration of the P2X7 receptor antagonist A740003 effectively reduced both autophagy-related protein levels and Nox4 expression. In vitro experiments indicated that hypoxia induced upregulation of Nox4, p-PERK/PERK, ATF4, Beclin-1, and ATG5 in cardiomyocytes, A740003 could inhibit the expression of these proteins, while overexpression of Nox4 counteracted this effect. Collectively, our findings indicated that the P2X7 receptor expression was elevated in the infarcted border zone following MI and implicated its role in excessive autophagy induced by hypoxia in cardiomyocytes-at least partially through the Nox4/PERK/ATF4 pathway, thereby exacerbating myocardial injury following MI.

Sodium butyrate aids brain injury repair in neonatal rats

The aim of this study is to investigate the effects and mechanism of action of sodium butyrate (SB) on brain injury repair in neonatal rats. 126 neonatal SD rats were randomly allocated to 7 groups, and necrotizing enterocolitis (NEC) and hypoxic-ischemic brain injury (HIBI) rat models were established. Hematoxylin and eosin staining showed that SB intervention alleviated intestinal and brain injuries in the HIBI + SB, NEC + SB, and NEC + HIBI + SB groups. Compared to the NEC and NEC + HIBI groups, the NEC + SB and NEC + HIBI + SB groups had significantly higher interleukin (IL)-10 and lower IL-17 levels (P < 0.05). Immunohistochemistry revealed increased Bcl-2 expression and decreased Bax expression in the NEC + SB and NEC + HIBI + SB groups compared to the NEC and NEC + HIBI groups in intestinal and brain tissues (P < 0.05). Compared to the control group (CG), gut microbiota diversity decreased in the HIBI, NEC, and NEC + HIBI groups, and increased significantly in the HIBI + SB, NEC + SB, and NEC + HIBI + SB groups. SB may alleviate brain injury by modulating gut microbiota, affecting IL-10 and IL-17 levels, and regulating Bcl-2 and Bax expression in intestinal and brain tissues.

Metabolic Coordination Structures Contribute to Diabetic Myocardial Dysfunction

BACKGROUND

Individuals with diabetes are susceptible to cardiac dysfunction and heart failure, potentially resulting in mortality. Metabolic disorders frequently occur in patients with diabetes, and diabetes usually leads to remodeling of heart structure and cardiac dysfunction. However, the contribution and underlying mechanisms of metabolic and structural coupling in diabetic cardiac dysfunction remain elusive.

METHODS

Two mouse models of type 2 diabetes (T2DM) were used to assess alterations in glucose/lipid metabolism and cardiac structure. The potential metabolic-structural coupling molecule ACBP (acyl-coenzyme A-binding protein) was screened from 4 published datasets of T2DM-associated heart disease. In vivo loss-of-function and gain-of-function approaches were used to investigate the role of ACBP in diabetic cardiac dysfunction. The underlying mechanisms of metabolic and structural coupling were investigated by stable-isotope tracing metabolomics, coimmunoprecipitation coupled with mass spectrometry, and chromatin immunoprecipitation sequencing.

RESULTS

Diabetic mouse hearts exhibit enhanced lipid metabolism and impaired ultrastructure with marked cardiac systolic and diastolic dysfunction. Analysis of 4 T2DM public datasets revealed that Acbp was a significant lipid metabolism gene whose expression was upregulated. Consistently, ACBP expression levels were markedly elevated in the hearts of patients with diabetes and diabetic mice. Moreover, we constructed cardiomyocyte-specific Acbp knockout mice that exhibited attenuation of T2DM-induced cardiac remodeling and cardiac dysfunction, including attenuation of cardiac hypertrophy, fibrosis, ultrastructural damage, and enhanced cardiomyocyte contractility and cardiac function. Conversely, cardiac-specific Acbp overexpression via adeno-associated virus type 9, which encodes Acbp under the cTnT (cardiac troponin T) promoter, recapitulated cardiac dysfunction. Mechanistically, cardiac-specific Acbp knockout enhances glucose utilization in diabetic cardiomyocytes, suggesting a potential compensatory mechanism for insufficient ATP levels, highlighting its metabolic role. In addition, combined with mass spectrometry analysis revealed that ACBP binds MyBPC3 (myosin-binding protein C3) in T2DM individuals, which potentially prevents MyBPC3 from assisting the formation of cross-bridge structures between myosin and actin, thereby impairing myocardial contraction. Importantly, chromatin immunoprecipitation sequencing revealed that peroxisome proliferator-activated receptor γ regulates the transcriptional activity of Acbp.

CONCLUSIONS

Our findings demonstrated that ACBP mediates the bidirectional regulation of cardiomyocyte metabolic and structural associations and identified a promising therapeutic target for ameliorating cardiac dysfunction in patients with T2DM.

Sodium aescinate promotes apoptosis of pancreatic stellate cells and alleviates pancreatic fibrosis by inhibiting the PI3K/Akt/FOXO1 signaling pathways

Chronic pancreatitis (CP) is an inflammatory disease of progressive pancreatic fibrosis, and pancreatic stellate cells (PSCs) are key cells involved in pancreatic fibrosis. To date, there are no clinical therapies available to reverse inflammatory damage or pancreatic fibrosis associated with CP. Sodium Aescinate (SA) is a natural mixture of triterpene saponins extracted from the dried and ripe fruits of horse chestnut tree. It has been shown to have anti-inflammatory and anti-edematous effects. This study aims to explore the therapeutic potential of SA in CP and the molecular mechanism of its modulation. Through in vivo animal models and experiments, we found that SA significantly alleviated pancreatic inflammation and fibrosis in caerulein-induced CP mice model. In addition, SA inhibited the proliferation, migration and activation of PSCs as well as promoted apoptosis of PSCs through a series of experiments on cells in vitro including CCK-8 assay, Western blotting, immunofluorescence staining, wound-healing assay, Transwell migration assays, flow cytometric analysis, etc. Further RNA sequencing and in vitro validation assays revealed that inhibition of the PI3K/AKT/FOXO1 signaling pathway was involved in the SA mediated promotion of PSCs apoptosis, thus alleviating pancreatic fibrosis. In conclusion, this study revealed that SA may have promising potential as therapeutic agent for the treatment of CP, and the PI3K/AKT/FOXO1 pathway is a potential therapeutic target for pancreatic inflammation and fibrosis.

Modified weiling decoction inhibited excessive autophagy via AKT/mTOR/ULK1 pathway to alleviate T2DM: Integrating network pharmacology and experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

Weiling Decoction is a traditional Chinese herbal formula that has the function of removing dampness and transforming turbidity, and it is widely used in the treatment of metabolic diseases. The hypoglycemic and antihyperlipidemic effects of Modified Weiling Decoction (MWLD) have been clinically verified in patients with type 2 diabetes mellitus (T2DM), however, the molecular mechanism remains unclear.

AIM OF THE STUDY

To explore the hypoglycemic mechanism of MWLD based on integrative network pharmacology and experimental validation in vivo and in vitro.

MATERIALS AND METHODS

The overlap between T2DM-related genes and target genes of MWLD were deemed to the potential targets of MWLD in alleviating T2DM. Protein-protein interaction analysis was performed to find the core targets from above-mentioned potential targets, and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis and Gene Ontology (GO) analysis were carried out to gain the key pathways involved in the T2DM improvement by MWLD. T2DM mice and palmitic acid-induced HepG2 cells were employed to validate the mechanism of MWLD predicated by network pharmacology.

RESULTS

A total of 292 target genes from 113 bioactive compounds in MWLD were identified, among of which 42 genes were recognized as core genes of MWLD in ameliorating T2DM. KEGG analysis showed that the therapeutic effect of MWLD on T2DM may be associated with insulin resistance (IR), islet β cell dysfunction, AKT, and MAPK. We found that MWLD significantly reduced fasting blood glucose and improved oral glucose tolerance in T2DM mice. Meanwhile, MWLD activated the AKT/GSK3β pathway to increase liver glycogen production and improve glucose metabolism in T2DM mice. MWLD activated the AKT/mTOR/ULK1 signaling pathway and reversed the increase of autophagy associated proteins (LC3II, Beclin1, Cathepsin B, and LAMP2) in the liver of T2DM mice. Similar results were also confirmed palmitic acid-induced HepG2 cells, an in vitro model for IR. Conversely, AKT inhibitor MK2206 neutralized the effects of MWLD on autophagy and glucose uptake, which was consistent with these results that the main active components of MWLD show strong affinity with AKT1 analyzed by molecular docking.

CONCLUSION

Both in vivo and in vitro experiments showed that MWLD inhibited excessive autophagy through the AKT/mTOR/ULK1 pathway to improve hepatic IR, and stimulate liver glycogen production through AKT/GSK3β pathway.

Liver injury in sepsis: manifestations, mechanisms and emerging therapeutic strategies

Sepsis is defined as a condition related to infection that manifests with multiorgan dysfunction, representing a life-threatening state. Consequently, severe complications frequently occur, with liver injury being one of the most prevalent serious complications of sepsis. Liver dysfunction during sepsis serves as an independent predictor of mortality. This review provides a comprehensive overview of current research on sepsis-induced liver injury (SILI), encompassing the clinical manifestations, diagnostic criteria, pathogenesis and therapeutic strategies associated with this condition. SILI may manifest as hypoxic hepatitis due to ischemia and shock, cholestasis resulting from abnormal bile metabolism, or bile duct sclerosis. The pathophysiology of sepsis involves intricate interactions among the inflammatory response, oxidative stress, and cell death. All of these factors complicate treatment and represent potential targets for therapeutic intervention. Furthermore, this review addresses the limitations inherent in conventional therapies currently employed for managing SILI and emphasizes the potential of novel targeted strategies aimed at addressing the fundamental mechanisms underlying this condition.

Mitochondrial quality control: Biochemical mechanism of cardiovascular disease

Mitochondria play a key role in the regulation of energy homeostasis and ATP production in cardiac cells. Mitochondrial dysfunction can trigger several pathological events that contribute to the development and progression of cardiovascular diseases. These mechanisms include the induction of oxidative stress, dysregulation of intracellular calcium cycling, activation of the apoptotic pathway, and alteration of lipid metabolism. This review focuses on the role of mitochondria in intracellular signaling associated with cardiovascular diseases, emphasizing the contributions of reactive oxygen species production and mitochondrial dynamics. Indeed, mitochondrial dysfunction has been implicated in every aspect of cardiovascular disease and is currently being evaluated as a potential target for therapeutic interventions. To treat cardiovascular diseases and improve overall heart health, it is important to better understand these biochemical systems. These findings allow the achievement of targeted therapies and preventive measures. Therefore, this review investigates different studies that demonstrate how changes in mitochondrial dynamics like fusion, fission, and mitophagy contribute to the development or worsening of disorders related to heart diseases by summarizing current research on their role.

Role of hepatocyte-specific FOXO1 in hepatic glucolipid metabolic disorders induced by perfluorooctane sulfonate

Perfluorooctane sulfonate (PFOS), a prevalent perfluoroalkyl substance (PFAS), is widely present in various environmental media, animals, and even human bodies. It primarily accumulates in the liver, contributing to the disruption of hepatic metabolic homeostasis. However, the precise mechanism underlying PFOS-induced hepatic glucolipid metabolic disorders remains elusive. The transcription factor forkhead box protein O 1 (FOXO1) plays a crucial role in regulating hepatic glucolipid metabolism; however, its involvement in PFOS-induced hepatic glucolipid metabolic disorders has not been thoroughly explored. Molecular docking revealed high binding affinity between PFOS and FOXO1. Male C57BL/6 mice were exposed to PFOS at doses of 0.3, 1.0, and 3.0 mg/kg body weight for 12 weeks to assess its subchronic effects on hepatic glucolipid metabolism in this work. The results indicate that PFOS exposure increases hepatic acetylated FOXO1 expression, promotes liver lipid accumulation, suppresses gluconeogenesis, whereas fasting blood glucose levels remain unaffected but this dysregulation results in insulin resistance. Furthermore, hepatic deletion of FOXO1 in PFOS-exposed mice ameliorates liver injury and reduces lipid accumulation by suppressing hepatic autophagy without significantly affecting gluconeogenesis. In conclusion, FOXO1 may play a pivotal role in the development of PFOS-induced hepatic glucolipid metabolic disorder.

Autophagy in High-Fat Diet and Streptozotocin-Induced Metabolic Cardiomyopathy: Mechanisms and Therapeutic Implications

Metabolic cardiomyopathy, encompassing diabetic and obese cardiomyopathy, is an escalating global health concern, driven by the rising prevalence of metabolic disorders such as insulin resistance, type 1 and type 2 diabetes, and obesity. These conditions induce structural and functional alterations in the heart, including left ventricular dysfunction, fibrosis, and ultimately heart failure, particularly in the presence of coronary artery disease or hypertension. Autophagy, a critical cellular process for maintaining cardiac homeostasis, is frequently disrupted in metabolic cardiomyopathy. This review explores the role of autophagy in the pathogenesis of high-fat diet (HFD) and streptozotocin (STZ)-induced metabolic cardiomyopathy, focusing on non-selective and selective autophagy pathways, including mitophagy, ER-phagy, and ferritinophagy. Key proteins and genes such as PINK1, Parkin, ULK1, AMPK, mTOR, ATG7, ATG5, Beclin-1, and miR-34a are central to the regulation of autophagy in metabolic cardiomyopathy. Dysregulated autophagic flux impairs mitochondrial function, promotes oxidative stress, and drives fibrosis in the heart. Additionally, selective autophagy processes such as lipophagy, regulated by PNPLA8, and ferritinophagy, modulated by NCOA4, play pivotal roles in lipid metabolism and iron homeostasis. Emerging therapeutic strategies targeting autophagy, including plant extracts (e.g., curcumin, dihydromyricetin), endogenous compounds (e.g., sirtuin 3, LC3), and lipid/glucose-lowering drugs, offer promising avenues for mitigating the effects of metabolic cardiomyopathy. Despite recent advances, the precise mechanisms underlying autophagy in this context remain poorly understood. A deeper understanding of autophagy's regulatory networks, particularly involving these critical genes and proteins, may lead to novel therapeutic approaches for treating metabolic cardiomyopathy.

miR-486-5p diagnosed atrial fibrillation, predicted the risk of left atrial fibrosis, and regulated angiotensin II-induced cardiac fibrosis via modulating PI3K/Akt signaling through targeting FOXO1

This study focused on miR-486-5p in atrial fibrillation (AF) evaluating its clinical significance and revealing its regulatory mechanism in cardiac fibroblasts, aiming to explore a novel biomarker for AF. The study enrolled 131 AF patients and 77 non-AF individuals. With the help of polymerase chain reaction (PCR), the expression of miR-486-5p was evaluated. The significance of miR-486-5p in the diagnosis of AF and the occurrence of left atrial fibrosis (LAF) was assessed by receiver operating curve (ROC) and logistic analyses. The regulatory effect and mechanism of miR-486-5p on cardiac fibrosis were investigated in human cardiac fibroblasts treated with angiotensin II. miR-486-5p was significantly upregulated in AF patients and discriminated AF patients from non-AF individuals. Increasing miR-486-5p showed a significant association with decreasing left ventricular ejection fraction (LVEF), increasing left atrial diameter (LAD) and left ventricular end-diastolic diameter (LVEDd), and the high incidence of LAF in AF patients. Moreover, miR-486-5p was identified as a risk factor for LAF and could distinguish AF patients with LAF and without LAF. In cardiac fibroblasts, angiotensin II induced the upregulation of miR-486-5p and promoted cell proliferation, migration, and collagen synthesis. miR-486-5p negatively regulated forkhead box O1 (FOXO1) and its knockdown could reverse the promoted effect of angiotensin II. FOXO1 alleviated the effect of miR-486-5p, and the miR-486-5p/FOXO1 could activate PI3K/Akt signaling. The activation of PI3K/Akt signaling alleviated the enhanced proliferation, migration, and collagen synthesis of cardiac fibroblasts induced by angiotensin II, and its inhibition showed opposite effects. Increased miR-486-5p served as a biomarker for the diagnosis and development prediction of AF. miR-486-5p regulated cardiac fibroblast viability and collagen synthesis via modulating the PI3K/Akt signaling through targeting FOXO1.

GPX4 expression changes in proximal tubule cells highlight the role of ferroptosis in IgAN

As an important mechanism of renal injury, oxidative stress (OS) is inseparable from the occurrence of renal fibrosis and the rapid progression of renal failure. However, the contribution of OS to IgA nephropathy (IgAN), the primary driver of chronic kidney disease remains uncertain. To investigate the effects of OS in IgAN, and identify the mechanisms of cell and tissue injury and protection, single-cell RNA sequencing (scRNA-seq) data and microarray data of IgAN were collected and analyzed. Through gene set variation analysis (GSVA), we identified significant alterations in the activity of multiple OS pathways within the proximal tubule cells (PTCs) of IgAN patients. Subsequent enrichment analysis revealed that the differentially expressed genes associated with OS in PTCs were primarily linked to the process of ferroptosis. Therefore, regulators of ferroptosis were collected to define the ferroptosis activity of PTCs in IgAN, and we found that the activity of suppressing ferroptosis was significantly enhanced. Moreover, being the central controller of ferroptosis, the expression of GPX4 in the PTCs of IgAN is extremely significant, which has been further verified by immunohistochemistry in kidney tissues of IgAN patients. Additionally, the GSVA of microarray data of IgAN indicated that the activity of driving ferroptosis and suppressing ferroptosis in tubulointerstitium were markedly decreased, however, the inhibition of ferroptosis in the tubulointerstitium of IgAN is relatively stronger. These findings demonstrate that ferroptosis inhibition may be a potential mechanism to alleviate OS injury in IgAN, and GPX4 could not only function as a specific marker for PTCs in IgAN but also represent a potential therapeutic target to halt the progression of the disease.

Knockdown ATG5 gene by rAAV9 alleviates doxorubicin-induced cardiac toxicity by inhibiting GATA4 autophagic degradation

Doxorubicin (DOX) is a prevalent chemotherapeutic drug for treating several malignancies. However, the mechanisms of DOX induced cardiac toxicity is not fully understood. Previous studies have demonstrated that autophagy activation is essential in DOX-induced cardiac toxicity. Nevertheless, studies on the role of autophagy protein 5 (ATG5) in DOX-induced cardiac toxicity remain limited. Therefore, this study aimed to investigate the role of ATG5 in DOX-induced cardiac toxicity. Mice were intravenously administered DOX (5 mg/kg) for 4 weeks to establish a cardiac toxicity model. Heart function was determined using echocardiography, and cardiac tissue was assessed for protein expression, mRNA levels, fibrosis, and immunofluorescent staining. DOX treatment upregulated autophagy-related gene expression but inhibited autophagic flux in vitro and in vivo. DOX-treated mice exhibited decreased heart function and cardiomyocyte size and increased cardiac fibrosis, oxidative stress, and apoptosis. These effects of DOX were partially alleviated by rAAV9 expressing shRNA-ATG5 and deteriorated by rAAV9-ATG5. We demonstrated that genetic ATG5 knockdown or autophagy inhibition by chemical inhibitors increased GATA4 protein expression, which was reduced by ATG5 overexpression or autophagy activator in vitro and in vivo, suggesting that ATG5-mediated autophagy promoted GATA4 degradation. Moreover, enforced GATA4 re-expression significantly counteracted the toxic effects of ATG5 on DOX-treated hearts. In conclusion, our study demonstrated that manipulating ATG5 expression to regulate GATA4 degradation in the heart may be a promising approach for DOX-induced cardiac toxicity.

PIK3R3 regulates differentiation and senescence of periodontal ligament stem cells and mitigates age-related alveolar bone loss by modulating FOXO1 expression

INTRODUCTION

Periodontal diseases are prevalent among middle-aged and elderly individuals. There's still no satisfactory solution for tooth loss caused by periodontal diseases. Human periodontal ligament stem cells (hPDLSCs) is a distinctive subgroup of mesenchymal stem cells, which play a crucial role in periodontal supportive tissues, but their application value hasn't been fully explored yet. As a regulatory subunit of PI3K, PIK3R3's role in stem cell regulation remains poorly comprehended.

OBJECTIVES

This study aims to explore the regulatory effect of PIK3R3 on differentiation and senescence of hPDLSCs and the underlying mechanism, as well as whether overexpression of PIK3R3 mitigate alveolar bone loss in aged rats.

METHODS

Human PDLSC lines with both PIK3R3 knockdown and overexpression are established. Osteogenic, adipogenic, chondrogenic and senescent induction are used to test the effect of PIK3R3 on senescence in vitro. Model of alveolar bone loss in aged mice is used to reveal the effect of PIK3R3 in vivo. FOXO1 siRNA is used for mechanism exploration.

RESULTS

Knockdown of PIK3R3 inhibits the mRNA and protein expression of markers in osteogenic, adipogenic, and chondrogenic differentiation of hPDLSCs but promotes in vitro senescence of hPDLSCs, including senescence markers expression, telomerase density and reactive oxygen species. Overexpression of PIK3R3 has the opposite effect. Furthermore, the result of Micro-CT and tissue section shows that overexpression of PIK3R3 in elder rats mitigates alveolar bone loss. Mechanistically, PIK3R3 regulates senescence of hPDLSCs through modulating FOXO1 expression. Expression of FOXO1 is altered when PIK3R3 is knocked down or overexpressed in senescent medium. Knockdown of FOXO1 promotes senescence of hPDLSCs and the senescence promoting effect of knocking down PIK3R3 is weakened when FOXO1 is highly expressed.

CONCLUSION

These findings indicate that PIK3R3 modulates senescence of hPDLSCs by regulating FOXO1 expression and shows promise as a therapeutic target for mitigating age-related alveolar bone loss.

Long Non-Coding RNAs in Diabetic Cardiomyopathy: Potential Function as Biomarkers and Therapeutic Targets of Exercise Training

Recent studies emphasize the beneficial effects of exercise on diabetic cardiomyopathy (DCM), adding to the growing body of evidence that underscores the role of exercise in improving health outcomes. Despite this, a notable gap persists in the number of healthcare providers who actively prescribe exercise as a therapeutic intervention for DCM management. In addition, exercise modulates the expression of lncRNAs, which play a pivotal role in DCM progression. Further investigation into this relationship may facilitate the identification of novel biomarkers and therapeutic targets for DCM. This review consolidates recent advances in identifying lncRNAs biomarkers in DCM, summarizing the current knowledge on dysregulated lncRNAs and their molecular mechanisms. Additionally, it offers new insights into the mechanistic roles of lncRNAs, highlighting their potential as biomarkers and therapeutic targets for DCM. Overall, this review aims to inform future research and reinforce the significance of addressing diabetes-related cardiovascular diseases to potentially improve clinical outcomes.

Atractylenolide-III restrains cardiac fibrosis after myocardial infarction via suppression of the RhoA/ROCK1 and ERK1/2 pathway

BACKGROUND

Cardiac fibrosis, a critical factor in myocardial remodeling post-myocardial infarction (MI), can advance heart failure progression. Atractylenolide III (ATL-III), derived from Atractylodes lancea, has recognized antioxidant and anti-inflammatory effects; however, its influence on cardiac fibrosis remains unclear.

METHODS

MI was induced in mice by permanent ligation of the left anterior descending (LAD) coronary artery, followed by 2 weeks of ATL-III or dimethyl sulfoxide (DMSO) treatment. Cardiac fibrosis was assessed by echocardiography, tissue histology, and serum biomarkers of myocardial injury. In vitro, the effects of ATL-III on cardiac fibroblast (CF) proliferation and collagen deposition were evaluated using immunofluorescence, 5-Ethynyl-2'-deoxyuridine (EdU), and western blot techniques. Network pharmacology and molecular docking identified potential ATL-III targets.

RESULTS

ATL-III treatment significantly improved cardiac function, as evidenced by increased ejection fraction (EF) and fractional shortening (FS) and reduced left ventricular dilation. Histological analysis revealed decreased fibrotic areas in ATL-III-treated mice, along with reduced expression of fibrosis markers α-SMA and Collagen I. ATL-III also alleviated oxidative stress by reducing reactive oxygen species (ROS) and malondialdehyde (MDA) levels while increasing superoxide dismutase (SOD) activity. Furthermore, ATL-III suppressed inflammation, decreasing TNF-α, IL-6, and IL-1β protein and mRNA levels. In vitro, ATL-III inhibited TGF-β1-induced CF proliferation, migration, and differentiation, reducing the expression of fibrotic markers. Mechanistically, ATL-III suppressed the RhoA/ROCK1 and ERK1/2 signaling pathways, as confirmed by molecular docking and pathway analysis.

CONCLUSION

ATL-III demonstrates therapeutic potential in mitigating post-MI cardiac fibrosis by reducing oxidative stress, inflammation, and CF activation. These findings highlight ATL-III as a promising candidate for the treatment of cardiac fibrosis and associated heart failure.

Autophagy in cancer development, immune evasion, and drug resistance

Macroautophagy/autophagy is a highly conserved evolutionary mechanism involving lysosomes for the degradation of cytoplasmic components including organelles. The constitutive, basal level of autophagy is fundamental for preserving cellular homeostasis; however, alterations in autophagy can cause disease pathogenesis, including cancer. The role of autophagy in cancer is particularly complicated, since this process acts both as a tumor suppressor in precancerous stages but facilitates tumor progression during carcinogenesis and later stages of cancer progression. This shift between anti-tumor and pro-tumor roles may be influenced by genetic and environmental factors modulating key pathways such as those involving autophagy-related proteins, the PI3K-AKT-MTOR axis, and AMPK, which often show dysregulation in tumors. Autophagy regulates various cellular functions, including metabolism of glucose, glutamine, and lipids, cell proliferation, metastasis, and several types of cell death (apoptosis, ferroptosis, necroptosis and immunogenic cell death). These multifaceted roles demonstrate the potential of autophagy to affect DNA damage repair, cell death pathways, proliferation and survival, which are critical in determining cancer cells' response to chemotherapy. Therefore, targeting autophagy pathways presents a promising strategy to combat chemoresistance, as one of the major reasons for the failure in cancer patient treatment. Furthermore, autophagy modulates immune evasion and the function of immune cells such as T cells and dendritic cells, influencing the tumor microenvironment and cancer's biological behavior. However, the therapeutic targeting of autophagy is complex due to its dual role in promoting survival and inducing cell death in cancer cells, highlighting the need for strategies that consider both the beneficial and detrimental effects of autophagy modulation in cancer therapy. Hence, both inducers and inhibitors of autophagy have been introduced for the treatment of cancer. This review emphasizes the intricate interplay between autophagy, tumor biology, and immune responses, offering insights into potential therapeutic approaches that deploy autophagy in the cancer suppression.

Role of the Transcription Factor FoxO in Type 2 Diabetes and Its Complications

FoxO proteins represent a subfamily of the forkhead box family (Fox) superfamily of proteins. It is involved in cell proliferation, differentiation, oxidative stress, apoptosis as well as tumors and metabolic disorders by regulating cellular functions. This paper aims to summarize the role of the transcription factor FoxO in type 2 diabetes and its complications, which may add to the potential of FoxO as a therapeutic target for future research. The transcription factor FoxO is expressed in various tissues and participates in various bodily functions including cell proliferation, differentiation, apoptosis, tumor therapy, and metabolic processes, playing a crucial role in the human body. FoxO plays a positive role in attenuating oxidative stress, inflammation, and metabolic disorders, which are the main causes of type 2 diabetes and its complications. FoxO plays an important role in the regulation of type 2 diabetes and its complications, and more precise targeting studies of FoxO will help to prevent, regulate, and treat diabetes-related diseases.

Mechanisms and Therapeutic Strategies for Myocardial Ischemia-Reperfusion Injury in Diabetic States

In patients with myocardial infarction, one of the complications that may occur after revascularization is myocardial ischemia-reperfusion injury (IRI), characterized by a depleted myocardial oxygen supply and absence of blood flow recovery after reperfusion, leading to expansion of myocardial infarction, poor healing of myocardial infarction and reversal of left ventricular remodeling, and an increase in the risk for major adverse cardiovascular events such as heart failure, arrhythmia, and cardiac cell death. As a risk factor for cardiovascular disease, diabetes mellitus increases myocardial susceptibility to myocardial IRI through various mechanisms, increases acute myocardial infarction and myocardial IRI incidence, decreases myocardial responsiveness to protective strategies and efficacy of myocardial IRI protective methods, and increases diabetes mellitus mortality through myocardial infarction. This Review summarizes the mechanisms, existing therapeutic strategies, and potential therapeutic targets of myocardial IRI in diabetic states, which has very compelling clinical significance.

Polysaccharides targeting autophagy to alleviate metabolic syndrome

Metabolic syndrome is a prevalent non-communicable disease characterized by central obesity, insulin resistance, hypertension, hyperglycemia, and hyperlipidemia. Epidemiological statistics indicate that one-third of the world's population is affected by metabolic syndrome. Unfortunately, owing to complicated pathogenesis and limited pharmacological options, the growing prevalence of metabolic syndrome threatens human health worldwide. Autophagy is an intracellular degradation mechanism that involves the degradation of unfolded or aggregated proteins and damaged cellular organelles, thereby maintaining metabolic homeostasis. Increasing evidence indicates that dysfunctional autophagy is closely associated with the development of metabolic syndrome, making it an attractive therapeutic target. Furthermore, a growing number of plant-derived polysaccharides have been shown to regulate autophagy, thereby alleviating metabolic syndrome, such as Astragalus polysaccharides, Laminaria japonica polysaccharides, Ganoderma lucidum polysaccharides and Lycium barbarum polysaccharides. In this review, we summarize recent advances in the discovery of autophagy modulators of plant polysaccharides for the treatment of metabolic syndrome, with the aim of providing precursor compounds for the development of new therapeutic agents. Additionally, we look forward to seeing more diseases being treated with plant polysaccharides by regulating autophagy, as well as the discovery of more intricate mechanisms that govern autophagy.

Txnip promotes autophagic apoptosis in diabetic cardiomyopathy by upregulating FoxO1 and its acetylation

Autophagy dysfunction and apoptosis exacerbate the risk of heart failure in patients with diabetic cardiomyopathy (DCM). However, the interactions between autophagy and apoptosis in DCM and their underlying mechanisms remain poorly understood. This study induced type 1 DCM in C57BL/6 mice via streptozotocin injection and exposed H9C2 cells to high glucose to investigate these mechanisms. The study revealed a significant elevation in autophagic vesicles and compromised autophagic flux, accompanied by pronounced myocardial cell apoptosis in the myocardium of diabetic mice. Long-term exposure to high glucose in H9C2 cells led to enhanced autophagosome formation and impaired autophagic flux, while inhibition of autophagy with 3-MA reduced cell apoptosis. Additionally, we observed an increase in Txnip expression in the myocardium of diabetic mice and in high glucose-treated H9C2 cells, which regulates autophagic apoptosis in high glucose-treated H9C2 cells. Furthermore, Txnip regulates autophagic apoptosis through the modulation of forkhead box-1 (FoxO1) expression and acetylation. Prolonged high glucose exposure resulted in increased levels of phosphorylated sirtuin 1 (SIRT1) and reduced SIRT1/FoxO1 interaction, changes that were ameliorated by Txnip knockdown. Txnip overexpression elevated FoxO1 levels, which could be suppressed by NAC and GSH. These findings revealed that Txnip mediates autophagic apoptosis in DCM by upregulating FoxO1 via ROS and enhancing FoxO1 acetylation through the suppression of SIRT1 activity. The discovery of this new mechanism provides new perspectives and potential therapeutic targets for understanding and treating DCM.

A bibliometric and visualization analysis of global research status and frontiers on autophagy in cardiomyopathies from 2004 to 2023

BACKGROUND

Autophagy is intimately associated with the development of cardiomyopathy and has received widespread attention in recent years. However, no relevant bibliometric analysis is reported at present. In order to summarize the research status of autophagy in cardiomyopathy and provide direction for future research, we conducted a comprehensive, detailed, and multidimensional bibliometric analysis of the literature published in this field from 2004 to 2023.

METHODS

All literatures related to autophagy in cardiomyopathy from 2004 to 2023 was collected from the Web of Science Core Collection, and annual papers, global publication trends, and proportion charts were analyzed and plotted using GraphPad price v8.0.2. In addition, CtieSpace [6.2.4R (64-bit) Advanced Edition] and VOSviewer (1.6.18 Edition) were used to analyze and visualize these data.

RESULTS

Two thousand two hundred seventy-nine papers about autophagy in cardiomyopathy were accessed in the Web of Science Core Collection over the last 20 years, comprising literatures from 70 countries and regions, 2208 institutions, and 10 810 authors. China contributes 56.32% of the total publications, substantially surpassing other countries, while the United States is ranked first in frequency of citations. Among the top 10 authors, six are from China, and four are from the United States. Air Force Military Medical University was the institution with the highest number of publications, while the Journal of Molecular and Cellular Cardiology (62 articles, 2.71% of the total) was the journal with the highest number of papers published in the field. Clustering of co-cited references and temporal clustering analysis showed that ferroptosis, hydrogen sulfide mitophagy, lipid peroxidation, oxidative stress, and SIRT1 are hot topics and trends in the field. The principal keywords are oxidative stress, heart, and heart failure.

CONCLUSION

The research on autophagy in cardiomyopathy is in the developmental stage. This represents the first bibliometric analysis of autophagy in cardiomyopathy, revealing the current research hotspots and future research directions in this field.

Matairesinol blunts adverse cardiac remodeling and heart failure induced by pressure overload by regulating Prdx1 and PI3K/AKT/FOXO1 signaling

BACKGROUND

Pathological cardiac remodeling is a critical process leading to heart failure, characterized primarily by inflammation and apoptosis. Matairesinol (Mat), a key chemical component of Podocarpus macrophyllus resin, exhibits a wide range of pharmacological activities, including anti-hydatid, antioxidant, antitumor, and anti-inflammatory effects.

PURPOSE

This study aims to investigate whether Matairesinol alleviate cardiac hypertrophy and remodeling caused by pressure overload and to elucidate its mechanism of action.

METHODS

An in vitro pressure loading model was established using neonatal rat cardiomyocytes treated with angiotensin Ⅱ, while an in vivo model was created using C57 mice subjected to transverse aortic constriction (TAC). To activate the PI3K/Akt/FoxO1 pathway, Ys-49 was employed. Moreover, small interfering RNA (siRNA) and short hairpin RNA (shRNA) were utilized to silence Prdx1 expression both in vitro and in vivo. Various techniques, including echocardiography, wheat germ agglutinin (WGA) staining, HE staining, PSR staining, and Masson trichrome staining, were used to assess cardiac function, cardiomyocyte cross-sectional area, and fibrosis levels in rats. Apoptosis in myocardial tissue and in vitro was detected by TUNEL assay, while reactive oxygen species (ROS) content in tissues and cells was measured using DHE staining. Furthermore, the affinity of Prdx1 with Mat and PI3K was analyzed using computer-simulated molecular docking. Western blotting and RT-PCR were utilized to evaluate Prdx1 levels and proteins related to apoptosis and oxidative stress, as well as the mRNA levels of cardiac hypertrophy and fibrosis-related indicators.

RESULTS

Mat significantly alleviated cardiac hypertrophy and fibrosis induced by TAC, preserved cardiac function, and markedly reduced cardiomyocyte apoptosis and oxidative damage. In vitro, mat attenuated ang Ⅱ - induced hypertrophy of nrvms and activation of neonatal rat fibroblasts. Notably, activation of the PI3K/Akt/FoxO1 pathway and downregulation of Prdx1 expression were observed in TAC mice; however, these effects were reversed by Mat treatment. Furthermore, Prdx1 knockdown activated the PI3K/Akt/FoxO1 pathway, leading to exacerbation of the disease. Molecular docking indicated that Molecular docking indicated that Mat upregulated Prdx1 expression by binding to it, thereby inhibiting the PI3K/Akt/FoxO1 pathway and protecting the heart by restoring Prdx1 expression levels.

CONCLUSION

Matairesinol alleviates pressure overload-induced cardiac remodeling both in vivo and in vitro by upregulating Prdx1 expression and inhibiting the PI3K/Akt/FoxO1 pathway. This study highlights the therapeutic potential of Matairesinol in the treatment of cardiac hypertrophy and remodeling, providing a promising avenue for future research and clinical application.

The renin-angiotensin-aldosterone system: An old tree sprouts new shoots

The intricate physiological and pathological diversity of the Renin-Angiotensin-Aldosterone System (RAAS) underpins its role in maintaining bodily equilibrium. This paper delves into the classical axis (Renin-ACE-Ang II-AT1R axis), the protective arm (ACE2-Ang (1-7)-MasR axis), the prorenin-PRR-MAP kinases ERK1/2 axis, and the Ang IV-AT4R-IRAP cascade of RAAS, examining their functions in both physiological and pathological states. The dysregulation or hyperactivation of RAAS is intricately linked to numerous diseases, including cardiovascular disease (CVD), renal damage, metabolic disease, eye disease, Gastrointestinal disease, nervous system and reproductive system diseases. This paper explores the pathological mechanisms of RAAS in detail, highlighting its significant role in disease progression. Currently, in addition to traditional drugs like ACEI, ARB, and MRA, several novel therapeutics have emerged, such as angiotensin receptor-enkephalinase inhibitors, nonsteroidal mineralocorticoid receptor antagonists, aldosterone synthase inhibitors, aminopeptidase A inhibitors, and angiotensinogen inhibitors. These have shown potential efficacy and application prospects in various clinical trials for related diseases. Through an in-depth analysis of RAAS, this paper aims to provide crucial insights into its complex physiological and pathological mechanisms and offer valuable guidance for developing new therapeutic approaches. This comprehensive discussion is expected to advance the RAAS research field and provide innovative ideas and directions for future clinical treatment strategies.

Inhibition of the FOXO1-ROCK1 axis mitigates cardiomyocyte injury under chronic hypoxia in Tetralogy of Fallot by maintaining mitochondrial quality control

INTRODUCTION

Persistent chronic myocardial hypoxia causes disturbances in mitochondrial quality control (MQC), ultimately leading to increased cardiomyocyte injury in patients with Tetralogy of Fallot (TOF). The present study aimed to identify the key effector molecules of cardiomyocyte injury under chronic hypoxia in TOF.

METHODS

Clinical data from TOF patients were collected and whole transcriptome sequencing was performed on myocardial samples. Chronic hypoxia models were established in cardiac-specific knockout mice and cardiomyocytes, and a series of molecular experiments were used to determine the specific mechanisms involved.

RESULTS

Clinical cohort data and whole-transcriptome sequencing analysis of myocardial samples from TOF patients revealed that forkhead box O1 (FOXO1) plays an important role in chronic hypoxic cardiomyocyte injury. In a model of chronic hypoxia established in FOXO1 cardiac-specific knockout mice and FOXO1 gene-deficient cardiomyocytes, the AMPK signaling pathway regulates the expression of FOXO1, which in turn disrupts MQC by regulating the transcriptional activation of Rho-associated protein kinase 1 (ROCK1), and increasing the production of mitochondrial ROS, thereby exacerbating damage to cardiomyocytes. Excessive reactive oxygen species (ROS) production during MQC dysfunction further activates Cox7a2L to increase the assembly of the respiratory chain supercomplex. In addition, we found that miR-27b-3p partially binds to the 3' untranslated region of FOXO1 to exert a protective effect.

CONCLUSIONS

Maintenance of MQC under chronic hypoxia is achieved through a series of injury-protection mechanisms, suggesting that FOXO1 inhibition may be crucial for future mitigation of chronic hypoxic cardiomyocyte injury in TOF.

Eicosatrienoic acid inhibits estradiol synthesis through the CD36/FOXO1/CYP19A1 signaling pathway to improve PCOS in mice

Polycystic ovary syndrome (PCOS) is a common metabolic and endocrine disorder characterized by abnormal elevation in hormone levels, with currently lacking effective treatment options. N-3 polyunsaturated fatty acids (PUFA) have broad pharmacological activity and play a beneficial role in the development of PCOS. In this study, we observed that n-3 PUFA-eicosatrienoic acid (ETA) improves the estrous cycle and ovarian morphology in dehydroepiandrosterone (DHEA)-induced PCOS mice, particularly serum hormone levels. Additionally, it suppresses the expression of CYP19A1 and E2 synthesis in human granulosa-like tumor cell line (KGN) cells. Further investigation revealed that ETA significantly upregulates the expression of CD36, cAMP, P-PKA, and FOXO1 in KGN cells and mouse ovaries to lower E2 levels. This conclusion was supported by inhibiting CD36 and FOXO1 at both the mouse and cellular levels. Additionally, ETA treatment decreased the expression of ESR1, Kiss1, Gnrh in the hypothalamus, and GnRHR, Lhβ, Egr1, Pitx1, Sf1 in the pituitary of PCOS mice. No differences were observed after ETA treatment in the CD36 and FOXO1 inhibitor groups, indicating that ETA improves PCOS mice by regulating the hypothalamic-pituitary axis through E2 synthesis inhibition. In summary, we have elucidated for the first time the mechanism by which CD36 regulates E2 synthesis in ovarian granulosa cells and demonstrated that ETA activates the CD36 receptor to inhibit E2 synthesis through the cAMP/PKA/FOXO1/CYP19A1 signaling pathway, thereby improving hormonal imbalance and treating PCOS. This provides a new strategy for the effective prevention and treatment of PCOS.

In pre-clinical study fetal hypoxia caused autophagy and mitochondrial impairment in ovary granulosa cells mitigated by melatonin supplement

INTRODUCTION

Fetal hypoxia has long-term effects on postnatal reproductive functions and the mitochondrial impairments of ovarian granulosa cells may be one of the causes. Melatonin applied to mitigate mitochondrial dysfunction and autophagy in mammalian cells has been reported. However, the potential mechanisms by which fetal hypoxia damages reproductive function in neonatal female mice and the melatonin effects on this problem remain unclear.

OBJECTIVES

This research aimed to explore the mechanism that fetal hypoxia damages reproductive function in neonatal female mice and attempt to improve the reproductive function by treating with melatonin in vivo and in vitro.

METHODS

We established a fetal hypoxia model and confirmed that fetal hypoxia affects ovarian function by inducing GC excessive autophagy. Transcriptomic analysis, gene interference, cell immunofluorescence, immunohistochemistry and western blot were conducted to explore and verify the underlying mechanisms in mice GCs and KGN cells. Finally, melatonin treatment was executed on hypoxia-treated mice GCs and KGN cells and melatonin injection to fetal-hypoxia-treated mice to determine its effect.

RESULTS

The results of in vitro experiments found that fetal hypoxia led to mitochondrial dysfunction in ovarian GCs causing autophagic cell death. And the PI3K/Akt/FoxO pathway mediated the occurrence of this process by transcriptome analysis of ovarian GCs from normal and fetal hypoxia mice, which was further verified in mice GCs and KGN cells. Additionally, melatonin administration prevented autophagic injuries and mitochondrial impairments in hypoxia-treated mice GCs and KGN cells. Meanwhile, in vivo experiments by melatonin injection ameliorated oxidative stress of ovary in fetal-hypoxia-treated mice and improved their low fertility.

CONCLUSION

Our data found that fetal hypoxia causes ovarian GCs excessive autophagy leading to low fertility in neonatal female mice and mitigated by melatonin. These results provide a potential therapy for hypoxic stress-related reproductive disorders.

Mitochondrial-derived peptides in cardiovascular disease: Novel insights and therapeutic opportunities

BACKGROUND

Mitochondria-derived peptides (MDPs) represent a recently discovered family of peptides encoded by short open reading frames (ORFs) found within mitochondrial genes. This group includes notable members including humanin (HN), mitochondrial ORF of the 12S rDNA type-c (MOTS-c), and small humanin-like peptides 1-6 (SHLP1-6). MDPs assume pivotal roles in the regulation of diverse cellular processes, encompassing apoptosis, inflammation, and oxidative stress, which are all essential for sustaining cellular viability and normal physiological functions. Their emerging significance extends beyond this, prompting a deeper exploration into their multifaceted roles and potential applications.

AIM OF REVIEW

This review aims to comprehensively explore the biogenesis, various types, and diverse functions of MDPs. It seeks to elucidate the central roles and underlying mechanisms by which MDPs participate in the onset and development of cardiovascular diseases (CVDs), bridging the connections between cell apoptosis, inflammation, and oxidative stress. Furthermore, the review highlights recent advancements in clinical research related to the utilization of MDPs in CVD diagnosis and treatment.

KEY SCIENTIFIC CONCEPTS OF REVIEW

MDPs levels are diminished with aging and in the presence of CVDs, rendering them potential new indicators for the diagnosis of CVDs. Also, MDPs may represent a novel and promising strategy for CVD therapy. In this review, we delve into the biogenesis, various types, and diverse functions of MDPs. We aim to shed light on the pivotal roles and the underlying mechanisms through which MDPs contribute to the onset and advancement of CVDs connecting cell apoptosis, inflammation, and oxidative stress. We also provide insights into the current advancements in clinical research related to the utilization of MDPs in the treatment of CVDs. This review may provide valuable information with MDPs for CVD diagnosis and treatment.

piR112710 attenuates diabetic cardiomyopathy through inhibiting Txnip/NLRP3-mediated pyroptosis in db/db mice

PIWI-interacting RNAs (piRNAs) are involved in the regulation of hypertrophic cardiomyopathy, heart failure and myocardial methylation. However, their functions and the underlying molecular mechanisms in diabetic cardiomyopathy (DCM) have yet to be fully elucidated. In the present study, a pyroptosis-associated piRNA (piR112710) was identified that ameliorates cardiac remodeling through targeting the activation of inflammasomes and mitochondrial dysfunction that are mediated via the thioredoxin-interacting protein (Txnip)/NLRP3 signaling axis. Subsequently, the cardioprotective effects of piR112710 on both the myocardium from db/db mice and cardiomyocytes from neonatal mice that were incubated with a high concentration of glucose combined with palmitate were examined. piR112710 was found to significantly improve cardiac dysfunction in db/db mice, characterized by improved echocardiography, lower levels of fibrosis, attenuated expression levels of inflammatory factors and pyroptosis-associated proteins (namely, Txnip, ASC, NLRP3, caspase-1 and GSDMD-N), and enhanced myocardial mitochondrial respiratory functions. In cultured neonatal mice cardiomyocytes, piR112710 deficiency and high glucose along with palmitate treatment led to significantly upregulated expression levels of pyroptosis associated proteins and collagens, oxidative stress, mitochondrial dysfunction and increased levels of inflammatory factors. Supplementation with piR112710, however, led to a reversal of the aforementioned changes induced by high glucose and palmitate. Mechanistically, the cardioprotective effect of piR112710 appears to be dependent upon effective elimination of reactive oxygen species and inactivation of the Txnip/NLRP3 signaling axis. Taken together, the findings of the present study have revealed that the piRNA-mediated inhibitory mechanism involving the Txnip/NLRP3 axis may participate in the regulation of pyroptosis, which protects against DCM both in vivo and in vitro. piR112710 may therefore be a potential therapeutic target for the reduction of myocardial injury caused by cardiomyocyte pyroptosis in DCM.

Downregulation of the (pro)renin receptor alleviates ferroptosis-associated cardiac pathological changes via the NCOA 4-mediated ferritinophagy pathway in diabetic cardiomyopathy

Ferroptosis, characterized by the accumulation of reactive oxygen species and lipid peroxidation, is involved in various cardiovascular diseases. (Pro)renin receptor (PRR) in performs as ligands in the autophagic process, and its function in diabetic cardiomyopathy (DCM) is not fully understood. We investigated whether PRR promotes ferroptosis through the nuclear receptor coactivator 4 (NCOA 4)-mediated ferritinophagy pathway and thus contributes to DCM. We first established a mouse model of DCM with downregulated and upregulated PRR expression and used a ferroptosis inhibitor. Myocardial inflammation and fibrosis levels were then measured, cardiac function and ferroptosis-related indices were assessed. In vitro, neonatal rat ventricular primary cardiomyocytes were cultured with high glucose and transfected with recombinant adenoviruses knocking down or overexpressing the PRR, along with a ferroptosis inhibitor and small interfering RNA for the ferritinophagy receptor, NCOA4. Ferroptosis levels were measured in vitro. The results showed that the knockdown of PRR not only alleviated cardiomyocyte ferroptosis in vivo but also mitigated the HG-induced ferroptosis in vitro. Moreover, administration of Fer-1 can inhibit HG-induced ferroptosis. NCOA4 knockdown blocked the effect of PRR on ferroptosis and improved cell survival. Our result indicated that inhibition of PRR and NCOA4 expression provides a new therapeutic strategy for the treatment of DCM. The effect of PRR on the pathological process of DCM in mice may be in promoting cardiomyocyte ferroptosis through the NCOA 4-mediated ferritinophagy pathway.

FoxO1 silencing in Atp7b-/- neural stem cells attenuates high copper-induced apoptosis via regulation of autophagy

Wilson disease (WD) is a severely autosomal genetic disorder triggered by dysregulated copper metabolism. Autophagy and apoptosis share common modulators that process cellular death. Emerging evidences suggest that Forkhead Box O1 over-expression (FoxO1-OE) aggravates abnormal autophagy and apoptosis to induce neuronal injury. However, the underlying mechanisms remain undetermined. Herein, the aim of this study was to investigate how regulating FoxO1 affects cellular autophagy and apoptosis to attenuate neuronal injury in a well-established WD cell model, the high concentration copper sulfate (CuSO4, HC)-triggered Atp7b-/- (Knockout, KO) neural stem cell (NSC) lines. The FoxO1-OE plasmid, or siRNA-FoxO1 (siFoxO1) plasmid, or empty vector plasmid was stably transfected with recombinant lentiviral vectors into HC-induced Atp7b-/- NSCs. Toxic effects of excess deposited copper on wild-type (WT), Atp7b-/- WD mouse hippocampal NSCs were tested by Cell Counting Kit-8 (CCK-8). Subsequently, the FoxO1 expression was evaluated by immunofluorescence (IF) assay, western blot (WB) and quantitative real-time polymerase chain reaction (qRT-PCR) analysis. Meanwhile, the cell autophagy and apoptosis were evaluated by flow cytometry (FC), TUNEL staining, 2,7-dichlorofluorescein diacetate (DCFH-DA), JC-1, WB, and qRT-PCR. The current study demonstrated a strong rise in FoxO1 levels in HC-treated Atp7b-/- NSCs, accompanied with dysregulated autophagy and hyperactive apoptosis. Also, it was observed that cell viability was significantly decreased with the over-expressed FoxO1 in HC-treated Atp7b-/- WD model. As intended, silencing FoxO1 effectively inhibited abnormal autophagy in HC-treated Atp7b-/- NSCs, as depicted by a decline in LC3II/I, Beclin-1, ATG3, ATG7, ATG13, and ATG16, whereas simultaneously increasing P62. In addition, silencing FoxO1 suppressed apoptosis via diminishing oxidative stress (OS), and mitochondrial dysfunction in HC-induced Atp7b-/- NSCs. Collectively, these results clearly demonstrate the silencing FoxO1 has the neuroprotective role of suppressing aberrant cellular autophagy and apoptosis, which efficiently attenuates neuronal injury in WD.

Regulatory T cells protect against diabetic cardiomyopathy in db/db mice

AIMS/INTRODUCTION

Regulatory T cells (Tregs) have protected against many cardiovascular diseases. This study was intended to explore the effect of Tregs on diabetic cardiomyopathy (DCM) using a db/db mouse model.

MATERIALS AND METHODS

Eight-week-old male db/db mice were randomly divided into four groups: the control group, administered 200 μL phosphate-buffered saline; the small-dose Treg group, administered 105 Tregs; the large-dose Treg group, administered 106 Tregs; and the PC group, administered 100 μg anti-CD25 specific antibody (PC61) and 106 Tregs. After 12 weeks, mice were euthanized. Transthoracic echocardiography was carried out at the beginning and end of the experiment. Relevant basic experiments to evaluate the effects of Tregs on DCM were carried out.

RESULTS

Echocardiography showed that the impaired diastolic and systolic functions were significantly improved in mice administered large-dose Tregs. Large-dose Tregs significantly ameliorated myocardial hypertrophy and fibrosis, and decreased hypertrophic gene expression and collagen deposition. The protective effects of Tregs on diabetic hearts were associated with decreased oxidative stress, inflammatory response and apoptosis. In addition, Tregs promoted the activation of the phosphatidylinositol 3-kinase-protein kinase B signaling pathway, whereas they inhibited extracellular signal-regulated kinase 1/2 and Jun N-terminal kinase phosphorylation, which might be responsible for the cardioprotective role of Tregs against DCM.

CONCLUSIONS

Tregs ameliorated myocardial hypertrophy and fibrosis, improved cardiac dysfunction, and protected against DCM progression in db/db mice. The mechanisms involved a decrease of inflammatory response, oxidative stress and apoptosis, which might be mediated by phosphatidylinositol 3-kinase-protein kinase B and mitogen-activated protein kinase pathways. Hence, Tregs might serve as a promising therapeutic approach for DCM treatment.

Forkhead box O1 transcription factor; a therapeutic target for diabetic cardiomyopathy

Cardiovascular disease including diabetic cardiomyopathy (DbCM) represents the leading cause of death in people with diabetes. DbCM is defined as ventricular dysfunction in the absence of underlying vascular diseases and/or hypertension. The known molecular mediators of DbCM are multifactorial, including but not limited to insulin resistance, altered energy metabolism, lipotoxicity, endothelial dysfunction, oxidative stress, apoptosis, and autophagy. FoxO1, a prominent member of forkhead box O transcription factors, is involved in regulating various cellular processes in different tissues. Altered FoxO1 expression and activity have been associated with cardiovascular diseases in diabetic subjects. Herein we provide an overview of the role of FoxO1 in various molecular mediators related to DbCM, such as altered energy metabolism, lipotoxicity, oxidative stress, and cell death. Furthermore, we provide valuable insights into its therapeutic potential by targeting these perturbations to alleviate cardiomyopathy in settings of type 1 and type 2 diabetes.

Hyperglycemia-induced Sirt3 downregulation increases microglial aerobic glycolysis and inflammation in diabetic neuropathic pain pathogenesis

BACKGROUND

Hyperglycemia-induced neuroinflammation significantly contributes to diabetic neuropathic pain (DNP), but the underlying mechanisms remain unclear.

OBJECTIVE

To investigate the role of Sirt3, a mitochondrial deacetylase, in hyperglycemia-induced neuroinflammation and DNP and to explore potential therapeutic interventions.

METHOD AND RESULTS

Here, we found that Sirt3 was downregulated in spinal dorsal horn (SDH) of diabetic mice by RNA-sequencing, which was further confirmed at the mRNA and protein level. Sirt3 deficiency exacerbated hyperglycemia-induced neuroinflammation and DNP by enhancing microglial aerobic glycolysis in vivo and in vitro. Overexpression of Sirt3 in microglia alleviated inflammation by reducing aerobic glycolysis. Mechanistically, high-glucose stimulation activated Akt, which phosphorylates and inactivates FoxO1. The inactivation of FoxO1 diminished the transcription of Sirt3. Besides that, we also found that hyperglycemia induced Sirt3 degradation via the mitophagy-lysosomal pathway. Blocking Akt activation by GSK69093 or metformin rescued the degradation of Sirt3 protein and transcription inhibition of Sirt3 mRNA, which substantially diminished hyperglycemia-induced inflammation. Metformin in vivo treatment alleviated neuroinflammation and diabetic neuropathic pain by rescuing hyperglycemia-induced Sirt3 downregulation.

CONCLUSION

Hyperglycemia induces metabolic reprogramming and inflammatory activation in microglia through the regulation of Sirt3 transcription and degradation. This novel mechanism identifies Sirt3 as a potential drug target for treating DNP.

Radiation Induced Skin Fibrosis (RISF): Opportunity for Angiotensin II-Dependent Intervention

Medical procedures, such as radiation therapy, are a vital element in treating many cancers, significantly contributing to improved survival rates. However, a common long-term complication of such exposure is radiation-induced skin fibrosis (RISF), a complex condition that poses substantial physical and psychological challenges. Notably, about 50% of patients undergoing radiation therapy may achieve long-term remission, resulting in a significant number of survivors managing the aftereffects of their treatment. This article delves into the intricate relationship between RISF, reactive oxygen species (ROS), and angiotensin II (Ang II) signaling. It proposes the underlying mechanisms and examines potential treatments for mitigating skin fibrosis. The primary goal is to offer essential insights in order to better care for and improve the quality of life of cancer survivors who face the risk of developing RISF.

Role of O-linked N-acetylglucosamine protein modification in oxidative stress-induced autophagy: a novel target for bone remodeling

O-linked N-acetylglucosamine protein modification (O-GlcNAcylation) is a dynamic post-translational modification (PTM) involving the covalent binding of serine and/or threonine residues, which regulates bone cell homeostasis. Reactive oxygen species (ROS) are increased due to oxidative stress in various pathological contexts related to bone remodeling, such as osteoporosis, arthritis, and bone fracture. Autophagy serves as a scavenger for ROS within bone marrow-derived mesenchymal stem cells, osteoclasts, and osteoblasts. However, oxidative stress-induced autophagy is affected by the metabolic status, leading to unfavorable clinical outcomes. O-GlcNAcylation can regulate the autophagy process both directly and indirectly through oxidative stress-related signaling pathways, ultimately improving bone remodeling. The present interventions for the bone remodeling process often focus on promoting osteogenesis or inhibiting osteoclast absorption, ignoring the effect of PTM on the overall process of bone remodeling. This review explores how O-GlcNAcylation synergizes with autophagy to exert multiple regulatory effects on bone remodeling under oxidative stress stimulation, indicating the application of O-GlcNAcylation as a new molecular target in the field of bone remodeling.

Targeting autophagy in diabetic cardiomyopathy: From molecular mechanisms to pharmacotherapy

Diabetic cardiomyopathy (DCM) is a cardiac microvascular complication caused by metabolic disorders. It is characterized by myocardial remodeling and dysfunction. The pathogenesis of DCM is associated with abnormal cellular metabolism and organelle accumulation. Autophagy is thought to play a key role in the diabetic heart, and a growing body of research suggests that modulating autophagy may be a potential therapeutic strategy for DCM. Here, we have summarized the major signaling pathways involved in the regulation of autophagy in DCM, including Adenosine 5'-monophosphate-activated protein kinase (AMPK), mechanistic target of rapamycin (mTOR), Forkhead box subfamily O proteins (FOXOs), Sirtuins (SIRTs), and PTEN-inducible kinase 1 (PINK1)/Parkin. Given the significant role of autophagy in DCM, we further identified natural products and chemical drugs as regulators of autophagy in the treatment of DCM. This review may help to better understand the autophagy mechanism of drugs for DCM and promote their clinical application.

MicroRNA-142-3p alleviated high salt-induced cardiac fibrosis via downregulating optineurin-mediated mitophagy

High salt can induce cardiac damage. The aim of this present study was to explore the effect and the mechanism of microRNA (miR)-142-3p on the cardiac fibrosis induced by high salt. Rats received high salt diet to induce cardiac fibrosis in vivo, and neonatal rat cardiac fibroblasts (NRCF) treated with sodium chloride (NaCl) to induce fibrosis in vitro. The fibrosis and mitochondrial autophagy levels were increased the heart and NRCF treated with NaCl, which were alleviated by miR-142-3p upregulation. The fibrosis and mitochondrial autophagy levels were elevated in NRCF after treating with miR-142-3p antagomiR. Optineurin (OPTN) expression was increased in the mitochondria of NRCF induced by NaCl, which was attenuated by miR-142-3p agomiR. OPTN downregulation inhibited the increases of fibrosis and mitochondrial autophagy levels induced by NaCl in NRCF. These results miR-142-3p could alleviate high salt-induced cardiac fibrosis via downregulation of OPTN to reduce mitophagy.

Baicalin alleviates angiotensin II-induced cardiomyocyte apoptosis and autophagy and modulates the AMPK/mTOR pathway

As a main extraction compound from Scutellaria baicalensis Georgi, Baicalin exhibits various biological activities. However, the underlying mechanism of Baicalin on hypertension-induced heart injury remains unclear. In vivo, mice were infused with angiotensin II (Ang II; 500 ng/kg/min) or saline using osmotic pumps, followed by intragastrically administrated with Baicalin (5 mg/kg/day) for 4 weeks. In vitro, H9C2 cells were stimulated with Ang II (1 μM) and treated with Baicalin (12.5, 25 and 50 μM). Baicalin treatment significantly attenuated the decrease in left ventricular ejection fraction and left ventricular fractional shortening, increase in left ventricular mass, left ventricular systolic volume and left ventricular diastolic volume of Ang II infused mice. Moreover, Baicalin treatment reversed 314 differentially expressed transcripts in the cardiac tissues of Ang II infused mice, and enriched multiple enriched signalling pathways (including apoptosis, autophagy, AMPK/mTOR signalling pathway). Consistently, Baicalin treatment significantly alleviated Ang II-induced cell apoptosis in vivo and in vitro. Baicalin treatment reversed the up-regulation of Bax, cleaved-caspase 3, cleaved-caspase 9, and the down-regulation of Bcl-2. Meanwhile, Baicalin treatment alleviated Ang II-induced increase of autophagosomes, restored autophagic flux, and down-regulated LC3II, Beclin 1, as well as up-regulated SQSTM1/p62 expression. Furthermore, autophagy inhibitor 3-methyladenine treatment alleviated the increase of autophagosomes and the up-regulation of Beclin 1, LC3II, Bax, cleaved-caspase 3, cleaved-caspase 9, down-regulation of SQSTM1/p62 and Bcl-2 expression after Ang II treated, which similar to co-treatment with Baicalin. Baicalin treatment reduced the ratio of p-AMPK/AMPK, while increased the ratio of p-mTOR/mTOR. Baicalin alleviated Ang II-induced cardiomyocyte apoptosis and autophagy, which might be related to the inhibition of the AMPK/mTOR pathway.

Human umbilical cord-derived mesenchymal stromal cells improve myocardial fibrosis and restore miRNA-133a expression in diabetic cardiomyopathy

BACKGROUND

Diabetic cardiomyopathy (DCM) is a serious health-threatening complication of diabetes mellitus characterized by myocardial fibrosis and abnormal cardiac function. Human umbilical cord mesenchymal stromal cells (hUC-MSCs) are a potential therapeutic tool for DCM and myocardial fibrosis via mechanisms such as the regulation of microRNA (miRNA) expression and inflammation. It remains unclear, however, whether hUC-MSC therapy has beneficial effects on cardiac function following different durations of diabetes and which mechanistic aspects of DCM are modulated by hUC-MSC administration at different stages of its development. This study aimed to investigate the therapeutic effects of intravenous administration of hUC-MSCs on DCM following different durations of hyperglycemia in an experimental male model of diabetes and to determine the effects on expression of candidate miRNAs, target mRNA and inflammatory mediators.

METHODS

A male mouse model of diabetes was induced by multiple low-dose streptozotocin injections. The effects on severity of DCM of intravenous injections of hUC-MSCs and saline two weeks previously were compared at 10 and 18 weeks after diabetes induction. At both time-points, biochemical assays, echocardiography, histopathology, polymerase chain reaction (PCR), immunohistochemistry and enzyme-linked immunosorbent assays (ELISA) were used to analyze blood glucose, body weight, cardiac structure and function, degree of myocardial fibrosis and expression of fibrosis-related mRNA, miRNA and inflammatory mediators.

RESULTS

Saline-treated diabetic male mice had impaired cardiac function and increased cardiac fibrosis after 10 and 18 weeks of diabetes. At both time-points, cardiac dysfunction and fibrosis were improved in hUC-MSC-treated mice. Pro-fibrotic indicators (α-SMA, collagen I, collagen III, Smad3, Smad4) were reduced and anti-fibrotic mediators (FGF-1, miRNA-133a) were increased in hearts of diabetic animals receiving hUC-MSCs compared to saline. Increased blood levels of pro-inflammatory cytokines (IL-6, TNF, IL-1β) and increased cardiac expression of IL-6 were also observed in saline-treated mice and were reduced by hUC-MSCs at both time-points, but to a lesser degree at 18 weeks.

CONCLUSION

Intravenous injection of hUC-MSCs ameliorated key functional and structural features of DCM in male mice with diabetes of shorter and longer duration. Mechanistically, these effects were associated with restoration of intra-myocardial expression of miRNA-133a and its target mRNA COL1AI as well as suppression of systemic and localized inflammatory mediators.

Counter-regulatory RAS peptides: new therapy targets for inflammation and fibrotic diseases?

The renin-angiotensin system (RAS) is an important cascade of enzymes and peptides that regulates blood pressure, volume, and electrolytes. Within this complex system of reactions, its counter-regulatory axis has attracted attention, which has been associated with the pathophysiology of inflammatory and fibrotic diseases. This review article analyzes the impact of different components of the counter-regulatory axis of the RAS on different pathologies. Of these peptides, Angiotensin-(1-7), angiotensin-(1-9) and alamandine have been evaluated in a wide variety of in vitro and in vivo studies, where not only they counteract the actions of the classical axis, but also exhibit independent anti-inflammatory and fibrotic actions when binding to specific receptors, mainly in heart, kidney, and lung. Other functional peptides are also addressed, which despite no reports associated with inflammation and fibrosis to date were found, they could represent a potential target of study. Furthermore, the association of agonists of the counter-regulatory axis is analyzed, highlighting their contribution to the modulation of the inflammatory response counteracting the development of fibrotic events. This article shows an overview of the importance of the RAS in the resolution of inflammatory and fibrotic diseases, offering an understanding of the individual components as potential treatments.

Total Glucosides of Paeony Ameliorate Myocardial Injury in Chronic Heart Failure Rats by Suppressing PARP-1

Total glucosides of paeony (TGP) have a potential protective effect on chronic heart failure (CHF) rats, but the mechanism remains unclear. PARP inhibition prevents the decrease in myocardial contractility. Therefore, we aim to investigate the effects and mechanisms of TGP on CHF and the role of PARP-1 in CHF. Left anterior descending ligation rats and adriamycin-treated H9C9 cells were used as CHF models, and captopril as a positive control for in vivo experiments. We found that TGP alleviated myocardial remodeling and improved cardiac morphology and function. TGP also reduced myocardial apoptosis and autophagy, decreased inflammatory factor release, and inhibited the PARP-1 and NF-κB proteins. Through cell transfection, we found that PAPR-1 knockdown inhibited NF-κB nuclear translocation. Additionally, TGP inhibited apoptosis, autophagy, and inflammation in CHF cells, while PARP-1 overexpression partially antagonized them. In conclusion, TGP has the potential to improve CHF and PARP-1 may be a potential target.

Roles of heat shock protein A12A in the development of diabetic cardiomyopathy

Long-term hyperglycemia can lead to diabetic cardiomyopathy (DCM), a main lethal complication of diabetes. However, the mechanisms underlying DCM development have not been fully elucidated. Heat shock protein A12A (HSPA12A) is the atypic member of the Heat shock 70kDa protein family. In the present study, we found that the expression of HSPA12A was upregulated in the hearts of mice with streptozotocin-induced diabetes, while ablation of HSPA12A improved cardiac systolic and diastolic dysfunction and increased cumulative survival of diabetic mice. An increased expression of HSPA12A was also found in H9c2 cardiac cells following treatment with high glucose (HG), while overexpression of HSPA12A-enhanced the HG-induced cardiac cell death, as reflected by higher levels of propidium iodide cells, lactate dehydrogenase leakage, and caspase 3 cleavage. Moreover, the HG-induced increase of oxidative stress, as indicated by dihydroethidium staining, was exaggerated by HSPA12A overexpression. Further studies demonstrated that the HG-induced increases of protein kinase B and forkhead box transcription factors 1 phosphorylation were diminished by HSPA12A overexpression, while pharmacologically inhibition of protein kinase B further enhanced the HG-induced lactate dehydrogenase leakage in HSPA12A overexpressed cardiac cells. Together, the results suggest that hyperglycemia upregulated HSPA12A expression in cardiac cells, by which induced cell death to promote DCM development. Targeting HSPA12A may serve as a potential approach for DCM management.

Myocardin reverses insulin resistance and ameliorates cardiomyopathy by increasing IRS-1 expression in a murine model of lipodystrophy caused by adipose deficiency of vacuolar H+-ATPase V0d1 subunit

Aim: Adipose tissue (AT) dysfunction that occurs in both obesity and lipodystrophy is associated with the development of cardiomyopathy. However, it is unclear how dysfunctional AT induces cardiomyopathy due to limited animal models available. We have identified vacuolar H+-ATPase subunit Vod1, encoded by Atp6v0d1, as a master regulator of adipogenesis, and adipose-specific deletion of Atp6v0d1 (Atp6v0d1AKO) in mice caused generalized lipodystrophy and spontaneous cardiomyopathy. Using this unique animal model, we explore the mechanism(s) underlying lipodystrophy-related cardiomyopathy. Methods and Results: Atp6v0d1AKO mice developed cardiac hypertrophy at 12 weeks, and progressed to heart failure at 28 weeks. The Atp6v0d1AKO mouse hearts exhibited excessive lipid accumulation and altered lipid and glucose metabolism, which are typical for obesity- and diabetes-related cardiomyopathy. The Atp6v0d1AKO mice developed cardiac insulin resistance evidenced by decreased IRS-1/2 expression in hearts. Meanwhile, the expression of forkhead box O1 (FoxO1), a transcription factor which plays critical roles in regulating cardiac lipid and glucose metabolism, was increased. RNA-seq data and molecular biological assays demonstrated reduced expression of myocardin, a transcription coactivator, in Atp6v0d1AKO mouse hearts. RNA interference (RNAi), luciferase reporter and ChIP-qPCR assays revealed the critical role of myocardin in regulating IRS-1 transcription through the CArG-like element in IRS-1 promoter. Reducing IRS-1 expression with RNAi increased FoxO1 expression, while increasing IRS-1 expression reversed myocardin downregulation-induced FoxO1 upregulation in cardiomyocytes. In vivo, restoring myocardin expression specifically in Atp6v0d1AKO cardiomyocytes increased IRS-1, but decreased FoxO1 expression. As a result, the abnormal expressions of metabolic genes in Atp6v0d1AKO hearts were reversed, and cardiac dysfunctions were ameliorated. Myocardin expression was also reduced in high fat diet-induced diabetic cardiomyopathy and palmitic acid-treated cardiomyocytes. Moreover, increasing systemic insulin resistance with rosiglitazone restored cardiac myocardin expression and improved cardiac functions in Atp6v0d1AKO mice. Conclusion: Atp6v0d1AKO mice are a novel animal model for studying lipodystrophy- or metabolic dysfunction-related cardiomyopathy. Moreover, myocardin serves as a key regulator of cardiac insulin sensitivity and metabolic homeostasis, highlighting myocardin as a potential therapeutic target for treating lipodystrophy- and diabetes-related cardiomyopathy.

Chronic intermittent hypoxia aggravated diabetic cardiomyopathy through LKB1/AMPK/Nrf2 signaling pathway

Chronic intermittent hypoxia (CIH) may play an important role in the development of diabetic cardiomyopathy (DCM). However, the exact mechanism of CIH-induced myocardial injury in DCM remains unclear. In vivo, the db/db mice exposed to CIH were established, and in vitro, the H9C2 cells were exposed to high glucose (HG) combined with intermittent hypoxia (IH). The body weight (BW), fasting blood glucose (FBG) and food intake were measured every two weeks. The glycolipid metabolism was assessed with the oral glucose tolerance test (OGTT) and insulin resistance (IR). Cardiac function was detected by echocardiography. Cardiac pathology was detected by HE staining, Masson staining, and transmission electron microscopy. The level of reactive oxygen species (ROS) in myocardial tissue was detected by dihydroethidium (DHE). The apoptosis was detected by TUNEL staining. The cell viability, ROS, and the mitochondrial membrane potential were detected by the cell counting kit-8 (CCK-8) assay and related kits. Western blotting was used to analyze the liver kinase B1/AMP-activated protein kinase/ nuclear factor-erythroid 2-related factor 2 (LKB1/AMPK/Nrf2) signaling pathway. CIH exposure accelerated glycolipid metabolism disorders and cardiac injury, and increased the level of cardiac oxidative stress and the number of positive apoptotic cells in db/db mice. IH and HG decreased the cell viability and the level of mitochondrial membrane potential, and increased ROS expression in H9C2 cells. These findings indicate that CIH exposure promotes glycolipid metabolism disorders and myocardial apoptosis, aggravating myocardial injury via the LKB1/AMPK/Nrf2 pathway in vitro and in vivo.

Lipoteichoic acid restrains macrophage senescence via β-catenin/FOXO1/REDD1 pathway in age-related osteoporosis

Osteoporosis and its related fractures are common causes of morbidity and mortality in older adults, but its underlying molecular and cellular mechanisms remain largely unknown. In this study, we found that lipoteichoic acid (LTA) treatment could ameliorate age-related bone degeneration and attenuate intramedullary macrophage senescence. FOXO1 signaling, which was downregulated and deactivated in aging macrophages, played a key role in the process. Blocking FOXO1 signaling caused decreased REDD1 expression and increased phosphorylation level of mTOR, a major driver of aging, as well as aggravated bone loss and deteriorated macrophage senescence. Moreover, LTA elevated FOXO1 signaling through β-catenin pathway while β-catenin inhibition significantly suppressed FOXO1 signaling, promoted senescence-related protein expression, and accelerated bone degeneration and macrophage senescence. Our findings indicated that β-catenin/FOXO1/REDD1 signaling plays a physiologically significant role that protecting macrophages from senescence during aging.