ox-LDL-Induced Endothelial Progenitor Cell Oxidative Stress via p38/Keap1/Nrf2 Pathway

Astragaloside IV Relieves Mitochondrial Oxidative Stress Damage and Dysfunction in Diabetic Mice Endothelial Progenitor Cells by Regulating the GSK-3β/Nrf2 Axis

Dysregulation of mitochondrial activity is a major cause of diabetes mellitus (DM) and its complications. Astragaloside IV, a natural herbal product, possesses protective properties against DM. This study aimed to evaluate how astragaloside IV affects oxidative stress and mitochondrial function in endothelial progenitor cells (EPCs) and elucidate the underlying mechanisms. A high glucose (HG)-induced human EPC (hEPC) model and a streptozotocin (STZ)-induced DM mouse model were established to investigate the effects of astragaloside IV on EPC function and wound healing in the context of DM. In HG-exposed hEPCs, astragaloside IV reduced apoptosis and increased cell viability and tube formation (P < 0.05). In STZ-induced DM mice, astragaloside IV promoted wound healing and increased the expression of the endothelial marker CD31 (P < 0.05) in wound tissues. In addition, the regulation of oxidative damage and mitochondrial dysfunction by astragaloside IV was investigated. We found that astragaloside IV attenuated mitochondrial damage, decreased ROS and mtROS levels (P < 0.05), decreased MDA activity and enhanced SOD activity (P < 0.05), and downregulated DPR1 levels and upregulated MFN1, MFN2, and OPA1 levels (P < 0.05). Mechanistically, the potential involvement of GSK-3β/Nrf2 was investigated by molecular docking and intervention with the GSK-3β activator sodium nitroprusside (SNP). Astragaloside IV was confirmed to dock with GSK-3β, and it increased the phosphorylation of GSK-3β (P < 0.05) and the expression of Nrf2 as well as its downstream factors HO-1 and NQO1 (P < 0.05). SNP reversed the protective effects of astragaloside IV. These results indicated that astragaloside IV attenuated HG- and STZ-induced injury through the GSK-3β/Nrf2 pathway. These results revealed that astragaloside IV may have the potential to be an active component for protection against DM and its complications.

miR-369-3p ameliorates diabetes-associated atherosclerosis by regulating macrophage succinate-GPR91 signalling

AIMS

Diabetes leads to dysregulated macrophage immunometabolism, contributing to accelerated atherosclerosis progression. Identifying critical factors to restore metabolic alterations and promote resolution of inflammation remains an unmet goal. MicroRNAs orchestrate multiple signalling events in macrophages, yet their therapeutic potential in diabetes-associated atherosclerosis remains unclear.

METHODS AND RESULTS

miRNA profiling revealed significantly lower miR-369-3p expression in aortic intimal lesions from Ldlr-/- mice on a high-fat sucrose-containing (HFSC) diet for 12 weeks. miR-369-3p was also reduced in peripheral blood mononuclear cells from diabetic patients with coronary artery disease (CAD). Cell-type expression profiling showed miR-369-3p enrichment in aortic macrophages. In vitro, oxLDL treatment reduced miR-369-3p expression in mouse bone marrow-derived macrophages (BMDMs). Metabolic profiling in BMDMs revealed that miR-369-3p overexpression blocked the oxidized low density lipoprotein (oxLDL)-mediated increase in the cellular metabolite succinate and reduced mitochondrial respiration (OXPHOS) and inflammation [Interleukin (lL)-1β, TNF-α, and IL-6]. Mechanistically, miR-369-3p targeted the succinate receptor (GPR91) and alleviated the oxLDL-induced activation of inflammasome signalling pathways. Therapeutic administration of miR-369-3p mimics in HFSC-fed Ldlr-/- mice reduced GPR91 expression in lesional macrophages and diabetes-accelerated atherosclerosis, evident by a decrease in plaque size and pro-inflammatory Ly6Chi monocytes. RNA-Seq analyses showed more pro-resolving pathways in plaque macrophages from miR-369-3p-treated mice, consistent with an increase in macrophage efferocytosis in lesions. Finally, a GPR91 antagonist attenuated oxLDL-induced inflammation in primary monocytes from human subjects with diabetes.

CONCLUSION

These findings establish a therapeutic role for miR-369-3p in halting diabetes-associated atherosclerosis by regulating GPR91 and macrophage succinate metabolism.

Diallyl trisulfide regulates PGK1/Nrf2 expression and reduces inflammation to alleviate neurological damage in mice after traumatic brain injury

BACKGROUND

Diallyl trisulfide (DATS) has a direct antioxidant capacity and emerges as a promising neuroprotective agent. This study was designed to investigate the role of DATS in traumatic brain injury (TBI).

METHODS

TBI mouse models were established using the controlled cortical impact, followed by DATS administration. The effects of DATS on neurological deficit, brain damage, inflammation and phosphoglycerate kinase 1 (PGK1) expression were detected using mNSS test, histological analysis, TUNEL assay, enzyme-linked immunosorbent assay and immunofluorescence. PC12 cells were subjected to H2O2-induced oxidative injury after pre-treatment with DATS, followed by cell counting kit-8 assay, flow cytometry and ROS production detection. Apoptosis-related proteins and the PGK1/nuclear factor erythroid-2 related factor 2 (Nrf2) pathway were examined using Western blot.

RESULTS

DATS ameliorated the cerebral cortex damage, neurological dysfunction and apoptosis, as well as decreased PGK1 expression and expressions of pro-inflammatory cytokines (IL-6, IL-1β, TNF-α) in mice after TBI. DATS also enhanced viability, blocked apoptosis and inhibited ROS production in H2O2-induced PC12 cells. DATS downregulated Cleaved-Caspase3, Bax and PGK1 levels, and upregulated Bcl-2 and Nrf2 levels in TBI mouse models and the injured cells.

CONCLUSION

DATS regulates PGK1/Nrf2 expression and inflammation to alleviate neurological damage in mice after TBI.

A comprehensive review on p38MAPK signaling as a potent radioprotector in testis

BACKGROUND

Previous studies have shown that the activation of p38MAPK signaling plays a crucial role in regulating gonadal cell fate decisions in both mouse and human. Excessive activation of p38MAPK by radiation significantly causes testicular damage and negatively affects the male reproductive function. Therefore, fine-tuned regulation of p38MAPK signaling is critical in both physiological and pathological conditions.

RESULT

This review summarizes the impact of p38MAPK signaling on testicular germ cells and microenvironment under normal condition. The relationship between radiation, reactive oxygen species (ROS), and p38MAPK is summarized. In conclusion, radiation exposure triggers the overactivation of p38MAPK, which is regulated by ROS, resulting in testicular damage. Various p38MAPK-targeting agents are discussed, providing guidance for developing new strategies.

AMPK deficiency inhibits fatty acid oxidation in endothelial progenitor cells to aggravate impaired angiogenesis after ischemic stroke in hyperlipidemic mice

BACKGROUND

Hyperlipidemia is a risk factor for stroke, and worsens neurological outcome after stroke. Endothelial progenitor cells (EPCs), which become dysfunctional in cerebral ischemia, hold capacity to promote revascularization.

OBJECTIVE

We investigated the role of dyslipidemia in impairment of EPC-mediated angiogenesis in cerebral ischemic mice.

METHODS AND RESULTS

The high fat diet (HFD)-fed mice following by ischemic stroke exhibited increased infarct volumes and neurological severity scores, and poorer angiogenesis. Bone marrow-EPCs treated with palmitic acid (PA) showed impaired functions and inhibited activity of AMP-activated protein kinase (AMPK). Notably, AMPK deficiency aggravated EPC dysfunction, further decreased mitochondrial membrane potential, and increased reactive oxygen species level in EPCs with PA treatment. Furthermore, the expression of fatty acid oxidation (FAO)-related genes was remarkably reduced, and carnitine palmitoyltransferase 1A (CPT1A) protein expression was downregulated in AMPK-deficient EPCs. AMPK deficiency aggravated neurological severity scores and angiogenesis in ischemic brain of HFD-fed mice, accompanied by suppressed protein level of CPT1A. EPC transplantation corrected impaired neurological severity scores and angiogenesis in AMPK-deficient mice.

CONCLUSION

Our findings suggest that AMPK deficiency aggravates poor angiogenesis in ischemic brain by mediating FAO and oxidative stress thereby inducing EPC dysfunction in hyperlipidemic mice.

14-3-3-η interacts with BCL-2 to protect human endothelial progenitor cells from ox-LDL-triggered damage

Oxidized low-density lipoprotein (ox-LDL) causes dysfunction of endothelial progenitor cells (EPCs), and we recently reported that 14-3-3-η can attenuate the damage triggered by ox-LDL in EPCs. However, the molecular mechanisms by which 14-3-3-η protects EPCs from the damage caused by ox-LDL are not fully understood. In this study, we observed that the expression of 14-3-3-η and BCL-2 were downregulated in ox-LDL-treated EPCs. Overexpression of 14-3-3-η in ox-LDL-treated EPC significantly increased BCL-2 level, while knockdown of BCL-2 reduced 14-3-3-η expression and mitigated the protective effect of 14-3-3-η on EPCs. In addition, we discovered that 14-3-3-η colocalizes and interacts with BCL-2 in EPCs. Taken together, these data suggest that 14-3-3-η protects EPCs from ox-LDL-induced damage by its interaction with BCL-2.

Inhibition of p38MAPK signalling pathway alleviates radiation-induced testicular damage through improving spermatogenesis

BACKGROUND AND PURPOSE

Damage to the testis following exposure to ionizing radiation has become an urgent problem to be solved. Here we have investigated if inhibition of p38 mitogen-activated protein kinase (p38MAPK) signalling could alleviate radiation-induced testicular damage.

EXPERIMENTAL APPROACH

In mice exposed to whole body radiation (2-6 Gy), morphological changes of the epididymis and testis was measured by histochemical staining. immunohistochemical and immunofluorescence procedures and western blotting were used to monitor expression and cellular location of proteins. Expression of genes was assessed by qPCR and RNA-Seq was used to profile gene expression.

KEY RESULTS

Exposure to ionizing radiation induced dose-dependent damage to mouse testis. The sperm quality decreased at 6 and 8 weeks after 6 Gy X-ray radiation. Radiation decreased PLZF+ cells and increased SOX9+ cells, and affected the expression of 969 genes, compared with data from non-irradiated mice. Expression of genes related to p38MAPK were enriched by GO analysis and were increased in the irradiated testis, and confirmed by qPCR. Levels of phospho-p38MAPK protein increased at 28 days after irradiation. In irradiated mice, SB203580 treatment increased spermatozoa, SOX9+ cells, the area and diameter of seminiferous tubules, sperm movement rate and density. Furthermore, SB203580 treatment increased SCP3+ cells, accelerating the process of spermatogenesis.

CONCLUSION AND IMPLICATIONS

Exposure to ionizing radiation clearly changed gene expression in mouse testis, involving activation of p38MAPK signalling pathways. Inhibition of p38MAPK by SB203580 partly alleviated the testicular damage caused by radiation and accelerated the recovery of sperms through promoting spermatogenesis.

Antidiabetic Effect of Collagen Peptides from Harpadon nehereus Bones in Streptozotocin-Induced Diabetes Mice by Regulating Oxidative Stress and Glucose Metabolism

Oxidative stress and abnormal glucose metabolism are the important physiological mechanisms in the occurrence and development of diabetes. Antioxidant peptides have been reported to attenuate diabetes complications by regulating levels of oxidative stress, but few studies have focused on peptides from marine bone collagen. In this study, we prepared the peptides with a molecular weight of less than 1 kD (HNCP) by enzymolysis and ultrafiltration derived from Harpadon nehereus bone collagen. Furthermore, the effects of HNCP on blood glucose, blood lipid, liver structure and function, oxidative stress, and glucose metabolism were studied using HE staining, kit detection, and Western blotting experiment in streptozocin-induced type 1 diabetes mice. After the 240 mg/kg HNCP treatment, the levels of blood glucose, triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C) in streptozotocin-induced diabetes mice decreased by 32.8%, 42.2%, and 43.2%, respectively, while the levels of serum insulin and hepatic glycogen increased by 142.0% and 96.4%, respectively. The antioxidant enzymes levels and liver function in the diabetic mice were markedly improved after HNCP intervention. In addition, the levels of nuclear factor E2-related factor 2 (Nrf2), glucokinase (GK), and phosphorylation of glycogen synthase kinase-3 (p-GSK3β) in the liver were markedly up-regulated after HNCP treatment, but the glucose-6-phosphatase (G6Pase) and phosphoenolpyruvate carboxykinase1 (PEPCK1) were down-regulated. In conclusion, HNCP could attenuate oxidative stress, reduce blood glucose, and improve glycolipid metabolism in streptozocin-induced type 1 diabetes mice.

Ox-LDL induced profound changes of small non-coding RNA in rat endothelial cells

Introduction

Atherosclerosis (AS) is a common cardiovascular disease with a high incidence rate and mortality. Endothelial cell injury and dysfunction are early markers of AS. Oxidative low-density lipoprotein (Ox-LDL) is a key risk factor for the development of AS. Ox-LDL promotes endothelial cell apoptosis and induces inflammation and oxidative stress in endothelial cells. Small non-coding RNAs (sncRNAs) mainly include Piwi-interacting RNAs (piRNAs), small nucleolar RNAs (snoRNAs), small nuclear RNAs (snRNAs), microRNAs (miRNAs) and repeat-associated RNAs. Studies have shown that small non-coding RNAs play an increasingly important role in diseases.

Methods

We used ox-LDL to treat rat endothelial cells to simulate endothelial cell injury. The expression changes of sncRNA were analyzed by small RNA high-throughput sequencing, and the expression changes of piRNA, snoRNA, snRNA, miRNA and repeat-associated RNA were verified by quantitative polymerase chain reaction (qPCR).

Results

Small RNA sequencing showed that 42 piRNAs were upregulated and 38 piRNAs were downregulated in endothelial cells treated with ox-LDL. PiRNA DQ614630 promoted the apoptosis of endothelial cells. The snoRNA analysis results showed that 80 snoRNAs were upregulated and 68 snoRNAs were downregulated in endothelial cells with ox-LDL treatment, and snoRNA ENSRNOT00000079032.1 inhibited the apoptosis of endothelial cells. For snRNA, we found that 20 snRNAs were upregulated and 26 snRNAs were downregulated in endothelial cells with ox-LDL treatment, and snRNA ENSRNOT00000081005.1 increased the apoptosis of endothelial cells. Analysis of miRNAs indicated that 106 miRNAs were upregulated and 91 miRNAs were downregulated in endothelial cells with ox-LDL treatment, and miRNA rno-novel-136-mature promoted the apoptosis of endothelial cells. The repeat RNA analysis results showed that 4 repeat RNAs were upregulated and 6 repeat RNAs were downregulated in endothelial cells treated with ox-LDL.

Discussion

This study first reported the expression changes of sncRNAs in endothelial cells with ox-LDL treatment, which provided new markers for the diagnosis and treatment of endothelial cell injury.

G0S2 ameliorates oxidized low-density lipoprotein-induced vascular endothelial cell injury by regulating mitochondrial apoptosis

Background

Oxidative low-density lipoprotein (ox-LDL)-induced endothelial cell damage is a major risk factor for atherosclerosis and its related cardiovascular diseases. The G0/G1 switch gene 2 (G0S2) is a multifunctional protein which has been poorly studied in atherosclerosis.

Methods

In this study, ox-LDL was utilized to construct a human aortic endothelial cell (HAEC) injury model.

Results

It was found that ox-LDL impaired cell viability, augmented lactate dehydrogenase (LDH) release, and reduced G0S2 levels in HAECs in a dose-dependent manner. Further, G0S2 overexpression improved the viability and restrained apoptosis of HAECs treated by ox-LDL. Conversely, G0S2 depletion decreased the viability and aggravated apoptosis of HAECs treated by ox-LDL. At the molecular level, G0S2 overexpression significantly increased the secretion of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPH-Px), promoted intracellular reactive oxygen species (ROS) production and malondialdehyde (MDA) content in HAECs under either normal or ox-LDL conditions. Meanwhile, the ox-LDL-induced mitochondrial dysfunction, as demonstrated by decreased mitochondrial membrane potential, translocation of mitochondrial cytochrome c (Cyt-c) to the cytoplasm, and activation of caspase-3 and caspase-9, was significantly reversed by G0S2 overexpression. In addition, G0S2 overexpression promoted the activation of AMP-activated protein kinase (AMPK) and increased the expression of nuclear factor erythroid-2-related factor-2 (Nrf2), sirtuin 1 (SIRT1) and heme oxygenase 1 (HO-1) under normal and ox-LDL conditions.

Conclusions

This study demonstrated that G0S2 protects against ox-LDL-induced vascular endothelial cell injury by regulating oxidative damage and mitochondrial homeostasis and may be a promising target for the treatment of atherosclerosis.

The potential function of SP1 and CPPED1 in restenosis after percutaneous coronary intervention

OBJECTIVES

Impacts of molecular pathways have been discussed recently on restenosis after percutaneous coronary intervention (PCI). Hence, this study aimed to explore the impact of calcineurin-like phosphoesterase domain containing 1 (CPPED1) and specificity protein 1 (SP1) on restenosis after PCI.

METHODS

A carotid balloon injury rat model was established, followed by western blot analysis of SP1 and CPPED1 expression in carotid artery (CA) tissues. After SP1 and CPPED1 were overexpressed, the neointimal hyperplasia and luminal stenosis were assessed. In addition, EPC underwent hypoxia/reoxygenation (H/R) treatment to construct an endothelial injury cell model. Then, cell proliferation, apoptosis, intracellular reactive oxygen species (ROS), and Ca²⁺ concentration were detected with cell counting kit-8 (CCK-8), flow cytometry, Chloromethyl-2'7'-dichlorofluorescein diacetate (CM-H2DCFDA) penetrant, and Fluo-4 AM staining, respectively. The binding relationship between SP1 and CPPED1 was verified by dual-luciferase reporter and chromatin immunoprecipitation (ChIP) assays.

RESULTS

SP1 and CPPED1 were lowly expressed in the model rats with carotid balloon injury. Mechanistically, SP1 bound to the promoter region of CPPED1 to activate CPPED1 expression. Overexpressing SP1 or CPPED1 lowered neointimal formation and restenosis rate, thus promoting the recovery of carotid balloon injury in rats. Meanwhile, SP1 and CPPED1 upregulation reduced ROS levels, Ca²⁺ concentration, and apoptosis of EPCs, accompanied by accelerated EPC viability.

CONCLUSIONS

SP1 or CPPED1 overexpression reduced neointimal formation and restenosis rate in carotid balloon injury.