Endurance exercise training inhibits neointimal formation via enhancement of FOXOs expression in balloon-induced atherosclerosis rat model

Mangiferin mitigates dexamethasone-induced insulin resistance in rats: insight into vascular dysfunction and hepatic steatosis

Aim

Insulin resistance (IR) is a hazard to human health in which peripheral insulin-target organs, like the liver, become less sensitive to normal levels of insulin. Dexamethasone (DEX)-induced IR is a distinct model of IR. Hence, the present study investigates the efficacy of mangiferin (Mang) in the reversal of DEX-induced IR in the livers and aortas of rats.

Main methods

Rats were randomly assigned into six groups: control (CTRL), Mang, DEX, and three pretreated groups (received Mang 25 mg/kg, 50 mg/kg, or 100 mg/kg, orally for 14 days, with DEX (1 mg/kg) injected from day 8 to day 14). On day 15, serum, liver, and aorta tissues were obtained and examined using biochemical, histological, and immunohistochemical assessments.

Key findings

Mang administration attenuated DEX-induced IR, evidenced by decreased oral glucose tolerance test (OGTT) and fasting serum insulin levels, in addition to improving the DEX-induced hepatic and aortic histopathological alterations. Additionally, Mang attenuated DEX-induced alterations in liver function parameters and improved serum lipid profiles, oxidative stress, and antioxidant biomarkers. Mang also markedly increased hepatic and aortic levels of insulin receptor substrate 1 (IRS1), protein kinase B (AKT), AMP-activated protein kinase (AMPK), and peroxisome proliferator-activated receptor-gamma (PPAR-γ) levels. Mang reduced hepatic and aortic tumor necrosis factor-alpha (TNF-α), forkhead box protein O1 (FOXO-1), hepatic NOD-like receptor family pyrin domain-containing 3 (NLRP3), phosphoenol pyruvate carboxy kinase (PEPCK), and glucose 6-phosphatase (G6Pase). Mang elevated hepatic glycogen synthase kinase3 (GSK3α) and glycogen synthase (GS2) levels. Furthermore, Mang ameliorated aortic expression levels of endothelin-1 (ET-1), vascular cell adhesion molecule-1 (VCAM), c-Jun N-terminal kinase (JNK), nuclear factor kappa B (NF-κB), and vascular endothelial growth factor (VEGF) and increased endothelial nitric oxide synthase (eNOS) and prostacyclin (PGI2) levels.

Conclusion

Mang administration could confer hepato- and vasculo-protective activity via its hypolipidemic, hepatoprotective, anti-inflammatory, and antioxidant efficacy.

Exercise attenuates high-fat diet-induced PVAT dysfunction through improved inflammatory response and BMP4-regulated adipose tissue browning

Background

Perivascular adipose tissue (PVAT) dysfunction impairs vascular homeostasis. Impaired inflammation and bone morphogenetic protein-4 (BMP4) signaling are involved in thoracic PVAT dysfunction by regulating adipokine secretion and adipocyte phenotype transformation. We investigated whether aerobic exercise training could ameliorate high-fat diet (HFD)-induced PVAT dysfunction via improved inflammatory response and BMP4-mediated signaling pathways.

Methods

Sprague-Dawley rats (n = 24) were divided into three groups, namely control, high-fat diet (HFD), and HFD plus exercise (HEx). After a 6-week intervention, PVAT functional efficiency and changes in inflammatory biomarkers (circulating concentrations in blood and mRNA expressions in thoracic PVAT) were assessed.

Results

Chronic HFD feeding caused obesity and dyslipidemia in rats. HFD decreased the relaxation response of PVAT-containing vascular rings and impaired PVAT-regulated vasodilatation. However, exercise training effectively reversed these diet-induced pathological changes to PVAT. This was accompanied by significantly (p < 0.05) restoring the morphological structure and the decreased lipid droplet size in PVAT. Furthermore, HFD-induced impaired inflammatory response (both in circulation and PVAT) was notably ameliorated by exercise training (p < 0.05). Specifically, exercise training substantially reversed HFD-induced WAT-like characteristics to BAT-like characteristics as evidenced by increased UCP1 and decreased FABP4 protein levels in PVAT against HFD. Exercise training promoted transcriptional activation of BMP4 and associated signaling molecules (p38/MAPK, ATF2, PGC1α, and Smad5) that are involved in browning of adipose tissue. In conjunction with gene expressions, exercise training increased BMP4 protein content and activated downstream cascades, represented by upregulated p38/MAPK and PGC1α proteins in PVAT.

Conclusion

Regular exercise training can reverse HFD-induced obesity, dyslipidemia, and thoracic PVAT dysfunction in rats. The browning of adipose tissue through exercise appears to be modulated through improved inflammatory response and/or BMP4-mediated signaling cascades in obese rats.

Aerobic exercise regulates FGF21 and NLRP3 inflammasome-mediated pyroptosis and inhibits atherosclerosis in mice

Fibroblast growth factor 21 (FGF21), a known risk factor for atherosclerosis, is readily regulated by exercise, and it can inhibit NOD-like receptor protein 3 (NLRP3)-mediated pyroptosis. However, it is not clear whether aerobic exercise inhibits atherosclerosis via these pathways. Eight-week-old apolipoprotein E-deficient (ApoE-/-) mice on a high-fat diet were randomly divided into 1-h post-exercise (EX-1h), 24-h post-exercise (EX-24h), and sedentary (SED) groups. C57BL/6J wild-type mice fed normal chow served as controls (WT group). Mice in the EX-1h and EX-24h groups were subjected to treadmill exercise training for 12 weeks. Aerobic exercise reduced body weight; blood glucose, lipid, and inflammation levels; and aortic plaque area proportion. Aerobic exercise increased the sensitivity of FGF21 by upregulating the expression of the downstream receptor adiponectin (ApN); the serum FGF21 level after exercise increased initially, and then decreased. Aerobic exercise downregulated the expression of NLRP3 inflammasome-mediated pyroptosis-related markers in the aorta, and FGF21 may participate in the above process. Meanwhile, the liver may be the tissue source of serum FGF21 during aerobic exercise. In conclusion, aerobic exercise may inhibit atherogenesis by regulating FGF21 and NLRP3 inflammasome-mediated pyroptosis. Our study provides new information on the atherosclerosis-preventing mechanism of aerobic exercise.

Aerobic Exercise Training Inhibits Neointimal Formation via Reduction of PCSK9 and LOX-1 in Atherosclerosis

The purpose of this study was to investigate whether aerobic exercise training inhibits atherosclerosis via the reduction of proprotein convertase subtilisin/kexin type 9 (PCSK9) expression in balloon-induced common carotid arteries of a high-fat-diet rats. Male SD (Sprague Dawley) rats fed an eight-weeks high-fat diet were randomly divided into three groups; these were the sham-operated control (SC), the balloon-induced control (BIC) and the balloon-induced exercise (BIE). The aerobic exercise training groups were performed on a treadmill. The major findings were as follows: first, body weight gain was significantly decreased by aerobic exercise training compared to the BIC without change of energy intake. Second, neointimal formation was significantly inhibited by aerobic exercise training in the balloon-induced common carotid arteries of high-fat-diet rats compared to the BIC. Third, low-density lipoprotein (LDL) receptor (LDLr) expression was significantly increased by aerobic exercise training in the livers of the high-fat diet group compared to the BIC, but not the proprotein convertase subtilisin/kexin type 9 (PCSK9) expression. Fourth, aerobic exercise training significantly decreased the expression of PCSK9, the lectin-like oxidized LDL receptor-1 (LOX-1), and vascular cell adhesion molecule-1 (VCAM-1) in balloon-induced common carotid arteries of high-fat-diet rats compared to the BIC. In conclusion, our results suggest that aerobic exercise training increases LDLr in the liver and inhibits neointimal formation via the reduction of PCSK9 and LOX-1 in balloon-induced common carotid arteries of high-fat-diet-induced rats.

Exercise-Induced Regulation of Redox Status in Cardiovascular Diseases: The Role of Exercise Training and Detraining

Although low levels of reactive oxygen species (ROS) are beneficial for the organism ensuring normal cell and vascular function, the overproduction of ROS and increased oxidative stress levels play a significant role in the onset and progression of cardiovascular diseases (CVDs). This paper aims at providing a thorough review of the available literature investigating the effects of acute and chronic exercise training and detraining on redox regulation, in the context of CVDs. An acute bout of either cardiovascular or resistance exercise training induces a transient oxidative stress and inflammatory response accompanied by reduced antioxidant capacity and enhanced oxidative damage. There is evidence showing that these responses to exercise are proportional to exercise intensity and inversely related to an individual’s physical conditioning status. However, when chronically performed, both types of exercise amplify the antioxidant defense mechanism, reduce oxidative stress and preserve redox status. On the other hand, detraining results in maladaptations within a time-frame that depends on the exercise training intensity and mode, as high-intensity training is superior to low-intensity and resistance training is superior to cardiovascular training in preserving exercise-induced adaptations during detraining periods. Collectively, these findings suggest that exercise training, either cardiovascular or resistance or even a combination of them, is a promising, safe and efficient tool in the prevention and treatment of CVDs.

Joint effect of a combination of components from the fruit of Crataegus pinnatifida Bge. Var. major N.E. Br. and the root of Salvia miltiorrhiza Bge. with swimming on atherosclerosis in rats

Background: It has been recognized that exercise training can attenuate the progression of atherosclerosis (AS). The combined application of components from the fruit of Crataegus pinnatifida Bge. Var. major N.E. Br. (CP) and the root of Salvia miltiorrhiza Bge. (SM) has been effective in the prevention and treatment of atherosclerosis. The present work aims to investigate the joint effects of extracts from the fruit of CP and the root of SM with swimming on atherosclerosis in rats. Method: To establish a rat atherosclerosis model, a combined method of partial ligation of the left common carotid artery leading to low shear stress and a high-fat diet was employed. Blood samples were collected to detect the blood lipid profile, which included total cholesterol (T-CHO), low-density lipoprotein cholesterol (LDL-C), triglycerides (TG) and high-density lipoprotein cholesterol (HDL-C); endothelial cytokines such as 6-keto-prostaglandin F1α (PGF1α), endothelin (ET), thromboxane B2 (TXB2), plasminogen activator inhibitor-1 (PAI-1), and von Willebrand factor (vWF); and inflammatory cytokines such as interleukin-1β (IL-1β), interleukin-6 (IL-6) and interleukin-10 (IL-10). Finally, the common carotid arteries of the rats were removed to observe pathological changes via oil red O staining, and the gene expression of t-PA, PAI-1, and vWF was assayed via real-time (RT) quantitative polymerase chain reaction (qPCR). Results: The joint effects of CPSM extract and swimming indicated significant interactions, including (1) decreased serum T-CHO, TG, and LDL-C; (2) decreased IL-6 and increased IL-10; (3) decreased TXB2, PAI-1 and vWF; three-dimensional analysis showed that gene expression of PAI-1 was inhibited, vWF gene expression was downregulated, and COX-1 gene expression was increased; and (4) decreased lipoprotein retention in the carotid artery wall. Conclusion: This research demonstrates that the combined therapy of CP and SM extracts with swimming can improve blood lipid levels and endothelial functions and attenuate the early signs of atherosclerosis in a rat model of atherosclerosis. The regulation of the gene expression of PAI, vWF and COX-1 may be the underlying cause of the effect. Methodologically speaking, three-dimensional surface plots of the joint effects of CPSM extract and swimming on parameters with quadratic fitting yielded a more accurate equation for describing the dose-response relationship in biomechanopharmacology. Such plots are likely worth using in pharmacology to quantify the effects induced by two medicinal factors.

Effect of resveratrol on seric vascular endothelial growth factor concentrations during atherosclerosis

INTRODUCTION

Although it is known that resveratrol has anti-inflammatory and anti-atherogenic actions, its effect on vascular endothelial growth factor (VEGF) in atherosclerosis is unknown.

OBJECTIVE

To evaluate the effect of resveratrol on serum concentrations of VEGF during the progression and evolution of atherosclerosis, as well as and its evolution over time in rabbits fed with a cholesterol diet.

MATERIALS AND METHODS

A total of 48 New Zealand white male rabbits were randomly divided into four groups of 12 rabbits: group1 (control): standard diet (commercial rabbit food); group2: cholesterol diet (0.5% cholesterol); group3 (control resveratrol): standard diet (commercial rabbit food) and resveratrol (2mg/Kg); group4: cholesterol diet (0.5% cholesterol) and resveratrol (2mg/Kg), for 12weeks. Blood samples of overnight-fasted rabbits were collected at baseline and the sixth and twelfth weeks, and the lipid profile, VEGF, and C-reactive protein (CRP) levels were determined. Half of the animals were sacrificed on the sixth or twelfth week, and the aorta was dissected for histological studies.

RESULTS

VEGF and CRP levels were significantly higher in groups2 and 4 than in groups1 and 3, respectively, from the 6th week (p<0.001). VEGF and CRP were significantly lower in group4 than in group2 on 12th week (p<0.004). Supplementation of resveratrol reduced the formation of atherosclerotic lesions.

CONCLUSIONS

Serum VEGF and CRP levels are early markers of atherosclerosis. Oral supplementation of resveratrol exerts anti-inflammatory and anti-atherosclerotic effects, decreasing serum concentrations of VEGF and CRP and the formation and evolution of atherosclerotic lesions.

CTRP3 promotes energy production by inducing mitochondrial ROS and up-expression of PGC-1α in vascular smooth muscle cells

C1q/tumor necrosis factor-related protein-3 (CTRP3) is an adipokine with modulation effects on metabolism and inflammation. Adenosine triphosphate (ATP) exerts multiple biological effects in vascular smooth muscle cells (VSMCs) and energy imbalance is involved in vascular diseases. This study aimed to explore the effect of CTRP3 on energy production and its underlying mechanism in VSMCs. Our results indicated that exogenous CTRP3 increased ATP synthesis and the protein expression of oxidative phosphorylation (OXPHOS)-related molecules, including peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α, sirtuin-3 (SIRT3), complex I, II, III, and V in cultured VSMCs. Depletion of endogenous CTRP3 by small interfering RNA (siRNA) reduced ATP synthesis and the expression of those molecules. PGC-1α knockdown abrogated CTRP3-induced ATP production and OXPHOS-related protein expression. Furthermore, CTRP3 increased mitochondrial reactive oxygen species (ROS) production and mitochondrial membrane potential level. Pretreatment with N-acetyl-L-cysteine, a reactive oxygen species scavenger, and cyanidem-chlorophenylhydrazone, an uncoupler of OXPHOS, suppressed CTRP3-induced ROS production, PGC-1α expression and ATP synthesis. In conclusion, CTRP3 modulates mitochondrial energy production through targets of ROS and PGC-1α in VSMCs.

Resistance exercise training increase activation of AKT-eNOS and Ref-1 expression by FOXO-1 activation in aorta of F344 rats

PURPOSE

This study investigated the effects of resistance exercise on the Akt-eNOS, the activation of antioxidant protein and FOXO1 in the aorta of F344 rats.

METHODS

Male 7 week-old F344 rats were randomly divided into 2 groups: a climbing group (n = 6) and a sedentary group (n = 6). H&E staining and western blotting were used to analyze the rat aortas and target proteins.

RESULTS

Resistance exercise training did not significantly affect aortic structure. Phosphorylation of AKT and eNOS and expression of MnSOD and Ref-1 were significantly increased while FOXO1 phosphorylation was significantly decreased in the resistance exercise group compared with the sedentary group.

CONCLUSION

We demonstrate that resistance exercise activates the Akt-eNOS and Ref-1 protein without changes to aortic thickness via FOXO-1 activation in the aorta of F344 rats.