Aortic Oxidative Stress Research Articles

Circulating miR-423-5p levels are associated with carotid atherosclerosis in patients with chronic kidney disease

Background and aimsCarotid atherosclerosis is associated with an elevated risk of stroke in patients with chronic kidney disease. However, the molecular basis for the incidence of carotid atherosclerosis in patients with CKD is poorly understood. Here, we investigated whether circulating miR-423-5p is a crucial link between CKD and carotid atherosclerosis. Methods and resultsWe recruited 375 participants for a cross-sectional study to examine the occurrence of carotid plaque and plaque thicknesses. Levels of miR-423-5p were determined by qPCR analysis. We found that non-dialysis CKD patients had higher circulating exosomal and plasma miR-423-5p levels, and dialysis-dependent patients had lower miR-423-5p levels than non-dialysis CKD patients. After excluding for the influence of dialysis patients, linear regression analysis indicated that levels of circulating miR-423-5p are negatively correlated with eGFR (P < 0.001). Higher plasma miR-423-5p levels were associated with the incidence and severity of carotid plaques. In parallel, we constructed a murine model of CKD with a 5/6 nephrectomy protocol and performed RNA sequencing studies of aortic tissues. Consistent with these findings in CKD patients, circulating exosomal miR-423-5p levels in CKD mice were elevated. Furthermore, our RNA-seq studies indicated that the putative target genes of miR-423-5p were related to oxidative stress functions for aorta of CKD mice. ConclusionLevels of miR-423-5p are associated with the presence and severity of carotid plaque in CKD. Data from our mouse model suggests that miR-423-5p likely influences gene expression programs related to oxidative stress in aorta of CKD mice.

Abstract 15060: Inhibition of Endoplasmic Reticulum Stress and YAP/TAZ Signaling Protects Endothelial Function in Diabetes

Introduction: Previous studies have demonstrated the role of Hippo pathway with its major effectors, Yes-associated protein (YAP) and transcription activator with PDZ binding motif (TAZ) in atherosclerosis. However, the involvement of YAP/TAZ signaling in diabetes-associated endothelial dysfunction remains unexplored. Hypothesis: We hypothesized that activation of YAP/TAZ signaling links with endoplasmic reticulum (ER) stress and contributes to endothelial dysfunction. Methods: Male C57BL/6 mice were fed with high-fat diet, 45% kcal% fat for 15 weeks to induce obesity and diabetes. ER stress alleviator 4-phenylbutyric acid was orally administered for 4 weeks at 100 mg/kg/day. Vascular reactivity of mouse aortas was assessed by wire myograph. Human umbilical vein endothelial cells (HUVECs) were cultured with risk factors such as high glucose and ER stress inducer tunicamycin. Western blot and immunofluorescent staining were performed to evaluate the expressions of protein targets. Results: YAP/TAZ signaling was activated accomplished with ER stress in aortas from obese diabetic mice and in endothelial cells treated with risk factors. Chronic treatment with 4-phenylbutyric acid ameliorated endothelium-dependent relaxations as well as inhibited ER stress, YAP/TAZ signaling and oxidative stress in aortas. Phosphorylation of YAP at Ser127 was reduced in mouse aortic arch which was downregulated by ER stress alleviator. In HUVECs, ER stress alleviators significantly inhibited YAP/TAZ signaling and increased NO bioavailability but YAP inhibitor did not suppress ER stress. Conclusions: ER stress activates YAP/TAZ signaling, resulting in endothelial dysfunction in diabetes. Inhibition of YAP/TAZ is vasoprotective and exhibits therapeutic potential against diabetic vascular complication.

The Synthetic Flavonoid Hidrosmin Improves Endothelial Dysfunction and Atherosclerotic Lesions in Diabetic Mice.

In diabetes, chronic hyperglycemia, dyslipidemia, inflammation and oxidative stress contribute to the progression of macro/microvascular complications. Recently, benefits of the use of flavonoids in these conditions have been established. This study investigates, in two different mouse models of diabetes, the vasculoprotective effects of the synthetic flavonoid hidrosmin on endothelial dysfunction and atherogenesis. In a type 2 diabetes model of leptin-receptor-deficient (db/db) mice, orally administered hidrosmin (600 mg/kg/day) for 16 weeks markedly improved vascular function in aorta and mesenteric arteries without affecting vascular structural properties, as assessed by wire and pressure myography. In streptozotocin-induced type 1 diabetic apolipoprotein E-deficient mice, hidrosmin treatment for 7 weeks reduced atherosclerotic plaque size and lipid content; increased markers of plaque stability; and decreased markers of inflammation, senescence and oxidative stress in aorta. Hidrosmin showed cardiovascular safety, as neither functional nor structural abnormalities were noted in diabetic hearts. Ex vivo, hidrosmin induced vascular relaxation that was blocked by nitric oxide synthase (NOS) inhibition. In vitro, hidrosmin stimulated endothelial NOS activity and NO production and downregulated hyperglycemia-induced inflammatory and oxidant genes in vascular smooth muscle cells. Our results highlight hidrosmin as a potential add-on therapy in the treatment of macrovascular complications of diabetes.

Berry consumption mitigates the hypertensive effects of a high-fat, high-sucrose diet via attenuation of renal and aortic AT1R expression resulting in improved endothelium-derived NO bioavailability

Dysregulation of the renin-angiotensin system (RAS) is a contributor to high-fat diet-related blood pressure (BP) increases. Deleterious effects of dysregulated RAS result in an overproduction of reactive oxygen species and a decrease in endothelial nitric oxide (NO) bioavailability due to increased NADPH oxidase (NOX) expression. Dietary polyphenols have been shown to mitigate the imbalance in the redox state and protect against endothelial dysfunction induced by a high-fat diet. Thus, we aim to determine whether polyphenol-rich blackberry and raspberry, alone and in combination, attenuate the detrimental effects of a high-fat, high-sucrose (HFHS) diet on the vascular endothelium and kidneys of mice. We show that a HFHS diet increased the expression of renal and aortic angiotensin type 1 receptor (AT1R). Further, NOX1 and NOX4 expression were increased in the kidney contributing to fibrotic damage. In human aortic endothelial cells (HAECs), palmitic acid increased the expression of NOX4, potentially driving oxidative damage in the aorta, as evidenced by increased nitrotyrosine expression. Berries reduced the expression of renal and aortic AT1R, leading to a subsequent decrease in renal NOX expression and reduced aortic oxidative stress evidenced by reduced nitrotyrosine expression. Blackberry and raspberry in combination increased the expression of NRF2 and its downstream proteins in HAECs, thereby reducing the oxidative burden to the endothelium. In combination, blackberry and raspberry also increased serum levels of NO metabolites. These findings indicate that blackberry and raspberry unique polyphenols may act synergistically to favorably modulate the abovementioned pathways and attenuate HFHS diet-induced increases in BP.

The effect of varied exercise intensity on antioxidant function, aortic endothelial function, and serum lipids in rats with non-alcoholic fatty liver disease.

This study aimed to compare the effects of diet and exercise of different intensities on antioxidant function, aortic endothelial cell function and serum lipids in NAFLD (nonalcoholic fatty liver disease) rats. Fifty Sprague-Dawley (SD) rats (180-220g) were randomly divided into two experimental groups and fed either a standard rodent chow diet (CON; n=10) or a high-fat diet (HFD; n=40). After 16 weeks, the animals that received the HFD were randomly separated into a high-fat control group (HFC; n=10) or three ex-ercise training groups: HFD and low-intensity exercise (LE; n=10), HFD and moderate-intensity exercise (ME; n=10), and HFD and incremental intensity exercise (IE; n=10). These experimental rats keep sedentary or trained for the next six weeks. A detection kit was used to detect nitric oxide synthase (NOs), nitric oxide (NO), malondialdehyde (MDA) and other markers of aor-tic oxidative stress. The expression levels of endothelial nitric oxide synthase (e-NOS) and endothelin-1 (ET-1) were detected by immunohistochemistry. TC, TG, and other lipid metabolism parameters were detected by an auto-matic analyzer. Exercise with different intensities could improve lipid me-tabolism, enhance antioxidant function, reduce MDA (P&lt;0.01), increase NO (P&lt;0.01), and improve the expression of e-NOS and ET-1 (P&lt;0.01) protein levels in NAFLD rats. Decreased blood lipids were exhibited in all exercise groups. Notably, the moderate-intensity exercise demonstrated more effecton increasing glutathione (GSH) contents (P&lt;0.01) and decreased the ex-pression of ET-1protein levels (P&lt;0.01). The results showed that exercise at different intensities improved lipid metabolism and enhanced anti-oxidation function. Moderate exercise could improve the function of aortic endothelial cells.

Allopurinol blocks aortic aneurysm in a mouse model of Marfan syndrome via reducing aortic oxidative stress.

Increasing evidence indicates that redox stress participates in MFS aortopathy, though its mechanistic contribution is little known. We reported elevated reactive oxygen species (ROS) formation and NADPH oxidase NOX4 upregulation in MFS patients and mouse aortae. Here we address the contribution of xanthine oxidoreductase (XOR), which catabolizes purines into uric acid and ROS in MFS aortopathy. In aortic samples from MFS patients, XOR protein expression, revealed by immunohistochemistry, increased in both the tunicae intima and media of the dilated zone. In MFS mice (Fbn1C1041G/+), aortic XOR mRNA transcripts and enzymatic activity of the oxidase form (XO) were augmented in the aorta of 3-month-old mice but not in older animals. The administration of the XOR inhibitor allopurinol (ALO) halted the progression of aortic root aneurysm in MFS mice. ALO administrated before the onset of the aneurysm prevented its subsequent development. ALO also inhibited MFS-associated endothelial dysfunction as well as elastic fiber fragmentation, nuclear translocation of pNRF2 and increased 3'-nitrotyrosine levels, and collagen maturation remodeling, all occurring in the tunica media. ALO reduced the MFS-associated large aortic production of H2O2, and NOX4 and MMP2 transcriptional overexpression. Allopurinol interferes in aortic aneurysm progression acting as a potent antioxidant. This study strengthens the concept that redox stress is an important determinant of aortic aneurysm formation and progression in MFS and warrants the evaluation of ALO therapy in MFS patients.

Jatrorrhizine Improves Endothelial Function in Diabetes and Obesity through Suppression of Endoplasmic Reticulum Stress.

Jatrorrhizine (JAT) is one of the major bioactive protoberberine alkaloids found in rhizoma coptidis, which has hypoglycemic and hypolipidemic potential. This study aimed to evaluate the vasoprotective effects of JAT in diabetes and obesity and the underlying mechanism involved. Mouse aortas, carotid arteries and human umbilical cord vein endothelial cells (HUVECs) were treated with risk factors (high glucose or tunicamycin) with and without JAT ex vivo and in vitro. Furthermore, aortas were obtained from mice with chronic treatment: (1) control; (2) diet-induced obese (DIO) mice fed a high-fat diet (45% kcal% fat) for 15 weeks; and (3) DIO mice orally administered JAT at 50 mg/kg/day for the last 5 weeks. High glucose or endoplasmic reticulum (ER) stress inducer tunicamycin impaired acetylcholine-induced endothelium-dependent relaxations (EDRs) in mouse aortas, induced oxidative stress in carotid arteries and HUVECs, downregulated phosphorylations of Akt at Ser473 and eNOS at Ser1177 and enhanced ER stress in mouse aortas and HUVECs, and these impairments were reversed by cotreatment with JAT. JAT increased NO release in high-glucose-treated mouse aortas and HUVECs. In addition, chronic JAT treatment restored endothelial function with EDRs comparable to the control, increased Akt/eNOS phosphorylation, and attenuated ER stress and oxidative stress in aortas from DIO mice. Blood pressure, glucose sensitivity, fatty liver and its morphological change, as well as plasma levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) and plasma lipid profile, were also normalized by JAT treatment. Collectively, our data may be the first to reveal the vasoprotective effect of JAT that ameliorates endothelial dysfunction in diabetes and obesity through enhancement of the Akt/eNOS pathway and NO bioavailability, as well as suppression of ER stress and oxidative stress.

Non-Additive Effects of Combined NOX1/4 Inhibition and Calcimimetic Treatment on a Rat Model of Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD).

ABSTRACTChronic kidney disease‐mineral and bone disorder (CKD‐MBD) increases cardiovascular calcification and skeletal fragility in part by increasing systemic oxidative stress and disrupting mineral homeostasis through secondary hyperparathyroidism. We hypothesized that treatments to reduce reactive oxygen species formation and reduce parathyroid hormone (PTH) levels would have additive beneficial effects to prevent cardiovascular calcification and deleterious bone architecture and mechanics before end‐stage kidney disease. To test this hypothesis, we treated a naturally progressive model of CKD‐MBD, the Cy/+ rat, beginning early in CKD with the NADPH oxidase (NOX1/4) inhibitor GKT‐137831 (GKT), the preclinical analogue of the calcimimetic etelcalcetide, KP‐2326 (KP), and their combination. The results demonstrated that CKD animals had elevated blood urea nitrogen, PTH, fibroblast growth factor 23 (FGF23), and phosphorus. Treatment with KP reduced PTH levels compared with CKD animals, whereas GKT treatment increased C‐terminal FGF23 levels without altering intact FGF23. GKT treatment alone reduced aortic calcification and NOX4 expression but did not alter the oxidative stress marker 8‐OHdG in the serum or aorta. KP treatment reduced aortic 8‐OHdG and inhibited the ability for GKT to reduce aortic calcification. Treatments did not alter heart calcification or left ventricular mass. In the skeleton, CKD animals had reduced trabecular bone volume fraction and trabecular number with increased trabecular spacing that were not improved with either treatment. The cortical bone was not altered by CKD or by treatments at this early stage of CKD. These results suggest that GKT reduces aortic calcification while KP reduces aortic oxidative stress and reduces PTH, but the combination was not additive. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Histopathology of aortic media tunica and plasma oxidative stress assessment during testosterone deficiency in male rats

Sexual hormones are determinant players in cardiovascular diseases. The aim of this study was to investigate the effects of testosterone deficiency, induced by castration, on oxidative status and the histopathology of the aor-tic media tunica. The experiments were undertaken on a batch of 30 Wistar males’ rats randomised into 3 groups, 10 control (Con), 10 castrated (Cas) and 10 castrated then supplemented with testosterone (Cas-T). Our results showed that testosterone deficiency induced a significant decrease in myeloperoxidase activity (19,95 ± 1, 79 vs 34,86 ± 1,13, p˂0,0001) this was maintained even after testosterone replacement. Furthermore, testosterone deficiency decreased the antioxidant capacity by reducing GSH in plasma (0,118 ± 0,003 vs 0,15 ± 0,011, p˂0,05). Our results also indicate that testos-terone supplementation leads to a significant increase in ceruloplasmin lev-els (62,37 ± 15,89 vs 148,12 ± 27,77, p ˂0.05). The histomorphometric exami-nation of the aortic tunica media in castrated rats showed a significant de-crease of media thickness (274,7 ± 2,96 vs 317,6 ± 5,19, p ˂0.0001) and VSMC count (108,1 ± 6,47 vs 130 ± 6,147, p ˂ 0.05) associated with damaged and broken elastic lamina. Testosterone supplementation restores the media thickness and the count of VSMC. Our findings demonstrate that testos-terone deficiency leads to a decrease in the count of VSMC and a rupture of elastic lamina. Testosterone altered the plasma oxidative status through ac-tions on GSH, MPO and ceruloplasmin.

Inhibition of endoplasmic reticulum stress combined with activation of angiotensin-converting enzyme 2: novel approach for the prevention of endothelial dysfunction in type 1 diabetic rats.

Persistent hyperglycemia in type 1 diabetes triggers numerous signaling pathways, which may prove deleterious to the endothelium. As hyperglycemia damages the endothelial layer via multiple signaling pathways, including enhanced oxidative stress, downregulation of angiotensin-converting enzyme 2 signaling, and exacerbation of endoplasmic reticulum (ER) stress, it becomes difficult to prevent injury using monotherapy. Thus, the present study was conceived to evaluate the combined effect of ER stress inhibition along with angiotensin-converting enzyme 2 activation, two major contributors to hyperglycemia-induced endothelial dysfunction, in preventing endothelial dysfunction associated with type 1 diabetes. Streptozotocin-induced diabetic animals were treated with either diminazene aceturate (5mg·kg-1 per day, p.o.) or tauroursodeoxycholic acid, sodium salt (200mg·kg-1 per day i.p.), or both for 4 weeks. Endothelial dysfunction was evaluated using vasoreactivity assay, where acetylcholine-induced relaxation was assessed in phenylephrine pre-contracted rings. Combination therapy significantly improved vascular relaxation when compared with diabetic control as well as monotherapy. Restoration of nitrite levels along with prevention of collagen led to improved vasodilatation. Moreover, there was an overall reduction in aortic oxidative stress. We conclude that by simultaneously inhibiting ER stress and activating angiotensin-converting enzyme 2 deleterious effects of hyperglycemia on endothelium were significantly alleviated. This could serve as a novel strategy for the prevention of endothelial dysfunction.

Abstract P282: Time Restricted Feeding In Mice On A Chronic High Fat Diet Leads To Reduced Aortic Damage And Oxidative Stress

Diet-induced obesity is associated with an increased risk of developing cardiovascular disease (CVD) . Aortic damage and stiffness are critical risk factors for CVD progression, especially with chronic high fat diet (HFD). Mice fed HFD ad libitum have increased food intake during the inactive period. We previously showed that HFD leads to significantly reduced blood pressure (BP) dipping and that time restricted food availability to the active period (TRF) in the final 2 weeks of HFD restores BP dipping. Thus, we hypothesized that TRF will reduce aortic damage and stiffness in chronic HFD mice. Utilizing this same mouse model of ad libitum chronic HFD (20 weeks 45% fat diet, male C57Bl6/J mice) compared to normal fat diet (NFD, 10% fat) and TRF intervention (food during lights off active period only from weeks 18-20), we determined aortic fibrosis and stiffness. By histological staining and quantitative analysis of the fibrosis area, HFD+TRF mice had significantly reduced fibrosis compared to HFD mice (% fibrosis per area, NFD: 143, NFD+TRF: 132, HFD: 175, HFD+TRF: 105, 2-way ANOVA, TRF effect: p=0.02). Aortic stiffness was measured by pulse wave velocity (PWV, Vevo 3100). We found that HFD fed mice have a significant increase in PWV compared to NFD group with no significant difference in the HFD+TRF and NFD+TRF groups compared to the NFD group (PWV m/sec, NFD: 1.60, NFD+TRF: 1.5, HFD: 2.30, HFD+TRF: 1.70, 2-way ANOVA, diet effect: p=0.02). We further analyzed plasma sE-selectin (endothelial-specific damage marker) and 8-isoprostane (oxidative stress marker) in HFD and HFD+TRF mice. Plasma from HFD+TRF mice showed significantly reduced sE-selectin and 8-isoprostane compared to HFD mice (sE-selectin ng/ml, HFD: 3.50, HFD+TRF: 1.85, p=0.027; 8-isoprostane ng/ml, HFD: 159.1, HFD+TRF: 59.6, p=0.008). Thus, TRF in chronic HFD mice leads to reduced endothelial injury and oxidative stress that is correlated with reduced aortic fibrosis and stiffness compared to ad libitum HFD mice. This study highlights that restricting the time of food intake in a model of diet-induced obesity minimizes CVD risk by reducing aortic damage and oxidative stress.

Changes in Gut Microbiota Induced by Doxycycline Influence in Vascular Function and Development of Hypertension in DOCA-Salt Rats.

Previous experiments in animals and humans show that shifts in microbiota and its metabolites are linked to hypertension. The present study investigates whether doxycycline (DOX, a broad-spectrum tetracycline antibiotic) improves dysbiosis, prevent cardiovascular pathology and attenuate hypertension in deoxycorticosterone acetate (DOCA)-salt rats, a renin-independent model of hypertension. Male Wistar rats were randomly assigned to three groups: control, DOCA-salt hypertensive rats, DOCA-salt treated with DOX for 4 weeks. DOX decreased systolic blood pressure, improving endothelial dysfunction and reducing aortic oxidative stress and inflammation. DOX decreased lactate-producing bacterial population and plasma lactate levels, improved gut barrier integrity, normalized endotoxemia, plasma noradrenaline levels and restored the Treg content in aorta. These data demonstrate that DOX through direct effects on gut microbiota and its non-microbial effects (anti-inflammatory and immunomodulatory) reduces endothelial dysfunction and the increase in blood pressure in this low-renin form of hypertension.

Melatonin attenuates aortic oxidative stress injury and apoptosis in STZ-diabetes rats by Notch1/Hes1 pathway

Oxidative stress injury is an important link in the pathogenesis of diabetes, and reducing oxidative stress damage caused by long-term hyperglycemia is an important diabetic treatment strategy. Melatonin has been proved to be a free radical scavenger with strong antioxidant activity, and its protective effect on diabetes and the complications has been confirmed. However, the role and potential mechanism of melatonin in oxidative stress injury of diabetic aorta have not been reported. Besides, Notch signaling pathway plays an important role in vascular growth, differentiation, and apoptosis. We speculated that melatonin could improve oxidative stress injury of diabetic aorta through Notch1/Hes1 signaling pathway. STZ-induced diabetic rats and vascular smooth muscle cells (VSMCs) cultured with high glucose were treated with or without melatonin, melatonin receptor antagonist Luzindole, γ-secretase inhibitor DAPT respectively. We found that melatonin could improve the oxidative stress injury of diabetic aorta and reduce the apoptosis of VSMCs. Interestingly, melatonin could activate Notch1 signaling pathway, play an antioxidant role, and reduce the expression of apoptosis-related proteins. However, these protective effects could be largely eliminated by Luzindole or DAPT. We concluded that the repression of Notch1 signaling pathway would inhibit the repair of oxidative stress injury in diabetes. Melatonin could ameliorate oxidative stress injury and apoptosis of diabetic aorta by activating Notch1/Hes1 signaling pathway.

Panax Notoginseng Protects against Diabetes-Associated Endothelial Dysfunction: Comparison between Ethanolic Extract and Total Saponin.

Previous studies revealed a cardioprotective potential of Panax notoginseng to relieve acute myocardial infarction and focal cerebral ischemia-reperfusion. However, whether P. notoginseng protects endothelial function in diabetes and the underlying mechanisms remain to be explored. P. notoginseng contains several chemical components including saponins, which are commonly believed as the major bioactive ingredients. The present study was aimed to examine and compare the vaso-protective effects of the ethanolic extract of P. notoginseng (PNE) and total saponin (PNS). Both aortas and carotid arteries were isolated from male C57BL/6J mice for ex vivo treatment with risk factors (high glucose or tunicamycin) with and without the presence of PNS and PNE. Diabetic model was established by feeding the mice with a high-fat diet (45% kcal% fat) for 12 weeks, while PNS and PNE were administrated by oral gavage at 20 mg/kg/day for another 4 weeks. Ex vivo exposure to high glucose impaired acetylcholine-induced endothelium-dependent relaxations in mouse aortas, decreased phosphorylation of AMPK and eNOS, and induced endoplasmic reticulum (ER) stress and oxidative stress. These effects were reversed by cotreatment of PNS and PNE with PNS being more potent. Furthermore, the vaso-protective effects were abolished by Compound C (AMPK inhibitor). Chronic treatment with PNS and PNE improved endothelium-dependent relaxations and alleviated ER stress and oxidative stress in aortas from high-fat diet-induced obese mice. PNE was more effective to improve glucose sensitivity and normalize blood pressure in diabetic mice. The present results showed that PNS and PNE reduced ER stress and oxidative stress and, subsequently, improved endothelial function in diabetes through AMPK activation. This study provides new inspiration on the therapeutic potential of P. notoginseng extract against vascular diseases associated with metabolic disorders.

Protocatechuic acid improves hepatic insulin resistance and restores vascular oxidative status in type-2 diabetic rats

This work explored influences of protocatechuic acid (PCA) on type 2 diabetes (T2D)-associated hepatic insulin resistance and other metabolic, hepatic and vascular irregularities using the rat model of high fat diet (HFD)+high fructose+low dose streptozotocin (STZ).Twenty-four male Wister rats were used. Twelve rats were ad libitum supplied with HFD and high fructose drinking water (25 % w/v) for 60 days. On day 30, they received a single injection of STZ (35 mg/kg, i.p). On day 32, they were divided into two subgroups (n = 6/each): T2D + PCA, received PCA (100 mg/kg/day, orally) and T2D, received PCA vehicle till the end of experiment. Rats provided with regular diet and fructose-free drinking water, with or without PCA treatment, served as PCA and control groups (n = 6/each), respectively.PCA treatment significantly reduced the elevated levels of fasting glycemia and insulin, AUCOGTT, AUCITT, and HOMA-IR index, while it boosted HOMA-β and insulinogenic index values in T2D rats. PCA ameliorated serum lipid levels and hepatic function parameters and mitigated hepatosteatosis in T2D rats. Mechanistically, PCA mitigated hepatic lipid peroxidation and restored reduced glutathione (GSH) and superoxide dismutase (SOD) to near-normal levels. Moreover, PCA enhanced hepatic protein levels of P-AKTser473 and hepatic mRNA expression of insulin receptor substrate 1 (IRS1), phosphatidylinositol 3 kinase (PI3K)-p85 and AKT2.Furthermore, PCA ameliorated aortic oxidative stress in T2D rats, possibly via reducing serum levels of advanced glycation end products (AGEs) and diminishing vascular expression of RAGE and NOX4 mRNA.Collectively, PCA may improve hepatic insulin resistance and vascular oxidative status by modulating IRS1/PI3K/AKT2 and AGE-RAGE-NOX4 pathways, respectively.

Schinus terebinthifolius fruits intake ameliorates metabolic disorders, inflammation, oxidative stress, and related vascular dysfunction, in atherogenic diet-induced obese rats. Insight of their chemical characterization using HPLC-ESI-QTOF-MS/MS

Ethnopharmacology relevanceSchinus terebinthifolius is traditionally used for its anti inflammatory capacity, and indicated as a cardioprotective agent, whereas, its preventive effect against atherogenic diet fed (AD) induced metabolic disorders and the underlying mechanisms has not yet been explored. Aim of the studyThis study was undertaken to investigate the ameliorative role of Schinus terebinthifolius fruits extract (STFE) against cardiovascular problem, oxidative and inflammatory status related to obesity in rats fed an atherogenic diet. Materials and methodsThe metabolites profile in STFE was evaluated using HPLC-DAD-ESI-QTOF-MS/MS analysis. In Wistar rats, atherogenic diet was added for 9 weeks to induce lipid accumulation simultaneously with STFE (50 mg/kg b. w) or saline treatment. Biochemical, oxidant, and inflammatory criteria together with hepatic and arterial integrity examination were assessed. ResultsA total of thirty three metabolites were identified using HPLC-DAD-ESI-QTOF-MS, among them masazino-flavanone was the major compound (2645.50 μg/g DW). The results indicated that STFE supplementation during 9 weeks (50 mg/kg b. w.) significantly attenuated the altered lipid profile by decreasing the levels of TC, TG, LDL-C and increasing the HDL-C content both in plasma and liver, when compared with the AD-group. The histological analysis using ORO staining revealed a decrease in the lipid droplet deposit in the cytoplasm of hepatocytes of STFE + AD group. The addition of STFE could improve the glycemic status of AD-treated rats by decreasing the glucose and insulin secretion, and ameliorating the hepatic glycogen synthesis. The harmful effects of atherogenic diet on hepatic oxidative stress indicators (MDA, PC, GSH, SOD, CAT, and GPx), biochemical markers (AST, ALT, LDH and ALP), and liver function, were found to be decreased by the addition of STFE. Moreover, the reduction of inflammatory markers (CRP, IL-6 and TNF-α), associated to alleviating of aortic oxidative stress and integrity, highlighted the positive anti-atherogenic effect of STFE. ConclusionOverall, the pleiotropic protective effect observed with S. terebinthifolius fruits might be related to the presence of various bioactive compounds.

Pemafibrate protects the rupture of experimental aortic aneurysm in mice through anti-oxidative stress with induced catalase

Abstract Background Abdominal aortic aneurysm (AAA) is a life-threatening disease, while effective and preventive medical treatments remain unestablished. Purpose The aim of this study was to evaluate the effect of selective peroxi- some proliferator-activated receptor alpha (PPARα) modulator pemafibrate on AAA formation in mice. Methods AAA was induced by subcutaneous infusion of angiotensin II (AngII) in apolipoprotein E-deficient mice for 4 weeks. Treatment by pemafibrate or vehicle was started one week before AngII infusion. Oxidative stress was evaluated by dihydroethidium (DHE) staining. Results Prognosis after AngII infusion in pemafibrate-treated mice was significantly better than that in vehicle-treated mice (log-rang test, p=0.035) by reducing the occurrence of fatal AAA rupture. Meanwhile pemafibrate did not significantly reduce maximal diameter of the aorta. Histological findings demonstrated that the expression of collagen in adventitia in pemafibrate-treated mice was significantly greater than that in vehicle-treated mice (p&amp;lt;0.05). Oxidative stress in aorta of pemafibrate-treated mice was significantly reduced comparing to vehicle-treated mice, accompanying by the reduction of mRNA expression of matrix metalloproteinase 2, tumor necrosis factor-α, and interleukin-6 (all p&amp;lt;0.05). Catalase expression in abdominal aortic tissue was increased 1.5-fold in mice treated with pemafibrate than in mice treated with vehicle (p=0.032). In human vascular smooth muscle cells (hVSMC), pemafibrate attenuated AngII-induced oxidative stress (p&amp;lt;0.001), which was canceled by administrating small interfering RNA (siRNA) of PPARα (p&amp;lt;0.001). Furthermore, in hVSMC, pemafibrate increased catalase expression significantly (p&amp;lt;0.001), while this increase was significantly suppressed by knockdown of PPAR-α with siRNA. (p&amp;lt;0.001). Conclusion Pemafibrate reduced the rupture of AAA in this murine model, which is associated with anti-oxidative stress via catalase induction. Funding Acknowledgement Type of funding source: None

Adipose extracellular signal-regulated kinase 2 protected from endothelial dysfunction and the oxidative stress of perivascular adipose tissue in obese mice

Abstract Introduction Extracellular signal-regulated kinase (ERK) modulates differentiation and maturation of adipocyte and the hypertrophy and differentiation of adipocytes affected the vascular diseases in obese. Changes in characters of adipocytes could develope the oxidative stress and inflammations. Moreover, changes in perivascular adipose tissue (PVAT) could modulate vascular tonus in obesity. However, the role of adipose ERK2 in endothelial function and characters of PVAT in obese in vivo had not been clarified, yet. Purpose This study aims to elucidate the role of the adipose ERK2 in endothelial-dependent relaxation (EDR) in mice model of obesity. The role of PVAT in EDR was also assessed. Methods and results We created adipose-specific ERK2 knock out mice (AE2KO) by crossing fatty acid binding protein 4 Cre and ERK2 flox mice and fed them with normal diet (ND) or high fat/ high sucrose diet (HFHSD) for 24 weeks. AE2KO fed with HFHSD gained more weight and revealed the heterogeneity in sizes of adipocyte in subcutaneous fat (SF). Furthermore, the mRNA levels of lipoprotein lipase, hormone-sensitive lipase, and peroxisome proliferator-activated receptor γ, which was the master genes of adipocyte differentiation, were markedly down-regulated in SF. PVAT in AE2KO with HFHSD was markedly enlarged and the mRNA expression of inflammatory adipocytokines, such as IL-1β and leptin were up-regulated. Next, we assessed EDR by acetylcholine (ACh) -induced relaxation in aortic rings with or without PVAT. EDR without PVAT was modestly decreased in AE2KO with HFHSD compared with wild type mice (WT) with HFHSD. Aortic rings with PVAT increased EDR in WT with ND. PVAT modestly decreased EDR in WT with HFHSD and mostly eliminated EDR in AE2KO with HFHSD. To assess the contraction factors released from PVAT, the solutions incubated with PVAT (SIP) were transferred to the normal aortic rings. SIP from WT with HFHSD mildly increased vascular tone and SIP from AE2KO with HFHSD further increased it. Tempol, which was superoxide scavenger, restored endothelial dysfunction with PVAT and suppressed the contraction with SIP from AE2KO with HFHSD. Fluorescence intensity of dihydroethidium stain of aorta and PVAT, which indicated that aortic and adipose superoxide production were elevated in AE2KO with HFHSD, which were mostly eliminated with tempol. Conclusions Adipose ERK2 selectively modulated differentiation in SF, suppressed the aortic oxidative stress and protected from endothelial dysfunction in obese. Moreover, adipose ERK2 suppressed the hypertrophy, inflammation, and oxidative stress of PVAT in obese. The oxidative stress with the inflammation in PVAT released vasoconstriction factors, which contributed to endothelial dysfunction in obese mice. Figure 1 Funding Acknowledgement Type of funding source: None

Mechanism of Inhibition of M1 Macrophage Expression and Activation of MIP-1α/CCL3 Signaling Pathway on Vascular Remodeling

Macrophages mediate the activation of MIP-1α/CCL3 signaling and participate in inflammatory response. In our study, M1 gene-deficient mice were used to assess the effect and mechanism of specific inhibition of macrophage M1 expression on angiotensin II-induced hypertensive vascular remodeling. Fifty 8-week-old male Lyz2-cre M1 gene-deficient mice and 50 Cre mice were divided into control group (saline group) and experimental group (angiotensin II group) followed by HE staining, collagen or elastin staining as well as measuring wall thickness. DHE staining was performed to observe the density of coronary artery and aortic oxidative stress. PCR Array was used to detect cytokine changes which were then verified by RT-PCR. The changes of aortic inflammatory factors were assessed by immunofluorescence and Western blotting. IHC was to measure MIP-1α level. Specific inhibition of M1 expression aggravated AngII-induced hypertensive vascular remodeling; Ang II stimulation increased vascular superoxide production by aggravation of ROS; specific inhibition of macrophage M1 expression significantly up-regulated vascular inflammatory cytokines and the expression and activation of MIP-1α/CCL3 in vascular smooth muscle cells to aggravate vascular remodeling. Further, in vitro cell experiments showed that MIP-1α significantly up-regulated CD31 tube staining. M1 is involved in AngII-induced hypertensive vascular remodeling by mediating the release of macrophage inflammatory factor MIP-1α/CCL3.

Aortic Oxidative Stress, Inflammation and DNA Damage Following Pulmonary Exposure to Cerium Oxide Nanoparticles in a Rat Model of Vascular Injury.

Pulmonary exposure to cerium oxide nanoparticles (CeO2 NPs) can occur either at the workplace, or due to their release in the environment. Inhaled CeO2 NPs are known to cross the alveolar–capillary barrier and reach various parts of the body, including the vasculature. The anticancer drug cisplatin (CP) causes vascular damage. However, the effects CeO2 NPs on vascular homeostasis in a rat model of CP-induced vascular injury remain unclear. Here, we assessed the impact and underlying mechanism of pulmonary exposure to CeO2 NPs on aorta in rats given a single intraperitoneal injection of cisplatin (CP, 6 mg/kg) to induce vascular damage. Six days later, the rats were intratracheally instilled with either CeO2 NPs (1 mg/kg) or saline (control), and various variables were studied 24 h thereafter in the aortic tissue. The concentration of reduced glutathione and the activity of catalase were significantly increased in the CP + CeO2 NPs group compared with both the CP + saline and the CeO2 NPs groups. The activity of superoxide dismutase was significantly decreased in the CP + CeO2 NPs group compared with both the CP + saline and CeO2 NPs groups. The expression of nuclear factor erythroid-derived 2-like 2 (Nrf2) by the nuclei of smooth muscles and endocardial cells assessed by immunohistochemistry was significantly augmented in CeO2 NPs versus saline, in CP + saline versus saline, and in CP + CeO2 NPs versus CeO2 NPs. Moreover, the concentrations of total nitric oxide, lipid peroxidation and 8-hydroxy-2-deoxyguanosine were significantly elevated in the CP + CeO2 NPs group compared with both the CP + saline and the CeO2 NPs groups. Similarly, compared with both the CP + saline and CeO2 NPs groups, the combination of CP and CeO2 NPs significantly elevated the concentrations of interleukin-6 and tumour necrosis factor-α. Additionally, aortic DNA damage assessed by Comet assay was significantly increased in CeO2 NPs compared with saline, and in CP + saline versus saline, and all these effects were significantly aggravated by the combination of CP and CeO2 NPs. We conclude that pulmonary exposure to CeO2 NPs aggravates vascular toxicity in animal model of vascular injury through mechanisms involving oxidative stress, Nrf2 expression, inflammation and DNA damage.