Inflammation, oxidative stress and renin angiotensin system in atherosclerosis

The effects of captopril on lipopolysaccharide induced learning and memory impairments and the brain cytokine levels and oxidative damage in rats

AIM

Renin-angiotensin system has a role in inflammation and also involves in learning and memory. In the present study, the effects of captopril on lipopolysaccharide (LPS) induced learning and memory impairments, hippocampal cytokine levels and brain tissues oxidative damage was investigated.

MATERIALS AND METHODS

The rats were divided and treated : [1] saline (Control), [2] LPS (1mg/kg), [3-5] 10, 50 or 100mg/kg captopril 30min before LPS. The treatment was started since six days before the behavioral experiments and continued during the behavioral tests (LPS injection two h before each behavioral experiment).

RESULTS

Administration of LPS prolonged the escape latency and traveled path to find the platform in Morris water maze (MWM) test (P<0.01-P<0.001) while, shortened the latency to enter the dark compartment in passive avoidance (PA) test (P<0.001). Pretreatment by all doses of captopril improved performances of the rats in MWM (P<0.05-P<0.001) and also prolonged the latency to enter the dark in PA test (P<0.001). LPS also increased IL-6, TNF-α, malondialdehyde (MDA) and nitric oxide(NO) metabolites in the hippocampal tissues (P<0.05-P<0.001) which were prevented by captopril (P<0.05-P<0.001). The thiol, superoxide dismutase(SOD) and catalase(CAT) in the hippocampus of LPS group were lower than the control (P<0.001) while, they were enhanced when the aniamls were pretraeted by captopril (P<0.01-P<0.001).

CONCLUSION

The results of present study showed that captopril improved the LPS-induced learning and memory impairments in rats which were accompanied with attenuating hippocampal cytokine levels and improving the brain tissues oxidative damage criteria.

Dimethyl Fumarate and Monomethyl Fumarate Promote Post-Ischemic Recovery in Mice

Oxidative stress plays an important role in cerebral ischemia-reperfusion injury. Dimethyl fumarate (DMF) and its primary metabolite monomethyl fumarate (MMF) are antioxidant agents that can activate the nuclear factor erythroid-2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway and induce the expression of antioxidant proteins. Here, we evaluated the impact of DMF and MMF on ischemia-induced brain injury and whether the Nrf2 pathway mediates the effects provided by DMF and MMF in cerebral ischemia-reperfusion injury. Using a mouse model of transient focal brain ischemia, we show that DMF and MMF significantly reduce neurological deficits, infarct volume, brain edema, and cell death. Further, DMF and MMF suppress glial activation following brain ischemia. Importantly, the protection of DMF and MMF was mostly evident during the subacute stage and was abolished in Nrf2-/- mice, indicating that the Nrf2 pathway is required for the beneficial effects of DMF and MMF. Together, our data indicate that DMF and MMF have therapeutic potential in cerebral ischemia-reperfusion injury and their protective role is likely mediated by the Nrf2 pathway.

Role of GPx4 in human vascular endothelial cells, and the compensatory activity of brown rice on GPx4 ablation condition

Oxidative stress is implicated in the pathologies of vascular endothelial cells. However, the importance of specific antioxidant enzymes in vascular endothelial cells is not fully understood. The purpose of this study was to elucidate the importance of Glutathione peroxidase 4 (GPx4), and the involvement of ferroptosis on cell death induced by GPx4 loss in human vascular endothelial cells. In addition, we examined the compensatory activity of brown rice on GPx4 ablation condition. Human umbilical vein endothelial cells were transfected with GPx4 or scramble control siRNA. GPx4 knockdown caused the increase in the levels of lipid oxidation, and induced cytotoxicity. On the other hand, α-tocopherol (vitamin E) and extract of brown rice, ameliorated lipid peroxidation, cytotoxicity, and delay of proliferation induced by GPx4 knockdown. Furthermore, ferrostatin-1, inhibitor of ferroptosis, also prevented cytotoxicity and delay of proliferation. In conclusion, our data demonstrated that GPx4 is an essential antioxidant enzyme for protecting lipid peroxidation, and is a regulator of ferroptosis in vascular endothelial cells. Furthermore, vitamin E rich food, such as brown rice, can compensate for GPx4 loss by protecting cells against lipid peroxidation.

Metabolic Syndrome, Redox State, and the Proteasomal System

SIGNIFICANCE

Since the metabolic syndrome (MS) and pathologies associated with/resulting from metabolic dysregulations became a worldwide spreading and growing problem, the mechanisms mediating the according cellular changes got into a focus of interest. The ubiquitin-proteasomal system (UPS) is the main regulator of both the functional and dysfunctional protein pool of (not only) mammalian cells-thus, it is obvious that an impact on this system may also affect cellular functionality that directly depends on permanent regulation/adaption of the cell's proteostasis. However, the according research is still at the beginning. Recent Advances: It was also recently shown that maintaining a highly functional UPS positively correlates with increased health or even life span, thus modulation or restoration of UPS function may be an effective approach alleviating or even preventing MS detrimental consequences.

CRITICAL ISSUES

Even if many consequences of metabolic dysregulation such as a slight but chronic redox shift to a more oxidative state (i.e., a low-grade systemic inflammation that increases reactive oxygen species formation, lipid peroxidation, protein oxidation, formation of advanced glycation end products, glycosylation, S-glutathionylation, redox shifts, endoplasmic reticulum stress, unfolded protein response, expression of transcription factors, and release of cytokines) are already known to affect the highly redox-regulated UPS, experimental data about UPS changes that are directly mediated by glucotoxic and/or lipotoxic stress are still rarely published.

FUTURE DIRECTIONS

It may be taken into account that many MS-related pathologic changes result from UPS dysfunction or dysregulation. In this review, the main interface between MS effects and their impact on the UPS are highlighted since they may direct to new therapeutic approaches. Antioxid. Redox Signal. 25, 902-917.

Impaired endogenous nighttime melatonin secretion relates to intrarenal renin-angiotensin system activation and renal damage in patients with chronic kidney disease

BACKGROUND

Activation of the intrarenal renin-angiotensin system (RAS) plays a critical role in the pathophysiology of chronic kidney disease (CKD) and hypertension. The circadian rhythm of intrarenal RAS activation leads to renal damage and hypertension, which are associated with diurnal blood pressure (BP) variation. The activation of intrarenal RAS following reactive oxygen species (ROS) activation, sympathetic hyperactivity and nitric oxide (NO) inhibition leads to the development of renal damage. Melatonin is a hormone regulating the circadian rhythm, and has multiple functions such as anti-oxidant and anti-adrenergic effects and enhancement of NO bioavailability. Nocturnal melatonin concentrations are lower in CKD patients. However, it is not known if impaired endogenous melatonin secretion is related to BP, intrarenal RAS, or renal damage in CKD patients.

METHODS

We recruited 53 CKD patients and conducted 24-h ambulatory BP monitoring. urine was collected during the daytime and nighttime. We investigated the relationship among the melatonin metabolite urinary 6-sulphatoxymelatonin (U-aMT6s), BP, renal function, urinary angiotensinogen (U-AGT), and urinary albumin (U-Alb).

RESULTS

Patients' U-aMT6s levels were significantly and negatively correlated with clinical parameters such as renal function, systolic BP, U-AGT, and U-Alb, during both day and night. Multiple regression analyses for U-aMT6s levels were performed using age, gender, renal function, and each parameter (BPs, U-AGT or U-Alb), at daytime and nighttime. U-aMT6s levels were significantly associated with U-AGT (β = -0.31, p = 0.044) and U-Alb (β = -0.25, p = 0.025) only at night.

CONCLUSION

Impaired nighttime melatonin secretion may be associated with nighttime intrarenal RAS activation and renal damage in CKD patients.

The Relationship between Neutrophil-to-Lymphocyte Ratio and Intracerebral Hemorrhage in Type 2 Diabetes Mellitus

INTRODUCTION

Chronic systematic inflammation has been suggested to be associated with the occurrence and development of cardiovascular events. Low-grade systematic inflammation persists in type 2 diabetes mellitus (T2DM) patients. In addition, the risk of cerebral hemorrhage in these patients is increased compared with non-diabetic patients. Neutrophil-to-lymphocyte ratio (NLR) is the ratio derived by dividing the neutrophil count with the lymphocyte count from a peripheral blood sample. This study aimed to explore the relation between NLR and cerebral hemorrhage, and to prove that NLR is an independent risk factor of cerebral hemorrhage in T2DM patients.

METHODS

In total, 429 cases of T2DM patients were included. The patients were divided into two groups depending on the presence of cerebral hemorrhage: the cerebral hemorrhage group (n = 87) and the control group (n = 342). Based on clinical and laboratory data of diabetes diagnosis, this article investigates the relationship between NLR and the risk of cerebral hemorrhage.

RESULTS

Increase in NLR was positively correlated with the incidence of cerebral hemorrhage in T2DM patients and might serve as an independent risk factor of cerebral hemorrhage in T2DM patients (OR: 4.451, 95% CI: 2.582-7.672). NLR >2.58 might be useful in predicting the threshold value of cerebral hemorrhage risk in newly diagnosed T2DM patients (area under the curve: .72, 95% CI: .659-.780, P < .001) CONCLUSION: As an indicator of the degree of systematic inflammation, NLR is an independent risk factor of cerebral hemorrhage in T2DM patients.

Associations between XRCC1 Gene Polymorphisms and Coronary Artery Disease: A Meta-Analysis

Genetic variations that influence DNA repair efficiency may contribute to coronary artery disease (CAD) susceptibility. Previous studies have investigated whether there was evidence of an association between polymorphisms at the X-ray repair cross complementing 1 (XRCC1) gene and susceptibility to CAD, but findings have been inconclusive. We identified eligible studies through a comprehensive literature search to determine whether an association exists between XRCC1 gene polymorphisms and CAD susceptibility. Findings were assessed using the odds ratio (OR) and corresponding 95% confidence interval (CI), which were calculated using a fixed- or random-effects model, based on the heterogeneity of the studies. Ten eligible studies were finally included in this meta-analysis. Our pooled analysis found that XRCC1 polymorphisms were significantly associated with CAD susceptibility under recessive (Arg194Trp: OR = 1.47, 95% CI = 1.13-1.93; Arg399Gln: OR = 1.45, 95% CI = 1.12-1.89), homozygous (Arg194Trp: OR = 1.37, 95% CI = 1.03-1.81; Arg399Gln: OR = 1.56, 95% CI = 1.19-2.05), and allele (Arg399Gln: OR = 1.18, 95% CI = 1.06-1.32) genetic models. Following subgroup analysis by ethnicity, in Asian populations, we found evidence of associations between the XRCC1 Arg194Trp polymorphism and CAD under recessive and homozygous genetic models, and between the XRCC1 Arg399Gln polymorphism and CAD under recessive, homozygous, and allele genetic models. Subgroup analysis stratified by control source revealed associations between the Arg194Trp and Arg399Gln polymorphisms and susceptibility to CAD under recessive and homozygous modes of inheritance, respectively. In addition, subgroup analysis stratified by sample size found that findings of the Arg194Trp polymorphism in large sample sizes were comparable to those found using pooled eligible studies. Based on our meta-analysis, we concluded that the XRCC1 gene polymorphisms, Arg194Trp and Arg399Gln, are associated with CAD susceptibility, specifically in Asian populations. However, additional, comprehensive and well-designed studies are warranted to confirm these findings.

Protein Inhibitor of Activated STAT3 Suppresses Oxidized LDL-induced Cell Responses during Atherosclerosis in Apolipoprotein E-deficient Mice

Atherosclerosis is a serious public health concern. Excessive inflammatory responses of vascular cells are considered a pivotal pathogenesis mechanism underlying atherosclerosis development. It is known that Janus kinase/signal transducer and activator of transcription 3 (JAK/STAT3) signalling plays an important role in atherosclerosis progression. Protein inhibitor of activated STAT3 (PIAS3) is the key negative regulator of JAK/STAT3 signalling. However, its effect on atherogenesis is unknown. Here, we observed that PIAS3 levels are reduced in atherosclerotic lesions and that PIAS3 expression decreases in conjunction with increases in interleukin-6 expression and atherosclerosis severity. Oxidized low-density lipoprotein (ox-LDL), an atherogenic stimulus, reduced PIAS3 expression, an effect that may be attributed to nitric oxide synthesis upregulation. In turn, PIAS3 overexpression effectively suppressed ox-LDL-induced inflammation, lipid accumulation and vascular smooth muscle cell proliferation. These results indicate that PIAS3 is a critical repressor of atherosclerosis progression. The findings of this study have contributed to our understanding on the pathogenesis of atherosclerosis and have provided us with a potential target through which we can inhibit atherosclerosis-related cellular responses.

Emerging roles and mechanisms of long noncoding RNAs in atherosclerosis

Atherosclerosis is the most common cause of heart attacks, strokes, and peripheral vascular disease. Atherosclerosis is predicted to be the primary cause of death in the world by 2020. Increasing evidence suggests that long non-protein-coding RNAs (lncRNAs) are important for the regulation of tissue homeostasis and pathophysiological conditions. Although knowledge about lncRNAs in atherosclerosis and other cardiovascular diseases is sparse, lncRNAs are clinically interesting because of their diagnostic and therapeutic value. This review summarizes knowledge about lncRNAs through their actions, related research methods and effects on atherosclerosis to provide helpful insights about how lncRNAs work and control atherosclerosis process and how lncRNA-related strategies could benefit human beings.

The protective role of vitamin D on the heart and the kidney

For a long time, vitamin D was regarded as an essential component for the maintenance of appropriate calcium metabolism. Indeed, the calcium-related functions were broadly studied and validated in numerous clinical and epidemiologic studies. All of these vitamin D effects are mediated by a specific receptor. Remarkably, recent investigations show that the vitamin D receptor (VDR) also affects autoimmunity and by these means, the course of neoplasias and tissue inflammation. Moreover, the VDR regulates genes that affect cellular activity including cell differentiation and apoptosis and, by these means, angiogenesis. Actually, vitamin D deficiency has been associated with structural and functional cardiovascular changes that can be reversed by receptor stimulation. In this regard, some of the injurious effects of vitamin D deficiency such as myocardial hypertrophy and high blood pressure seem linked to increased renin-angiotensin activity. Interestingly, chronic renal disease, a condition often associated with greater cardiovascular risk, high blood pressure, myocardial hypertrophy and inappropriate stimulation of the renin angiotensin system, is also tied to inadequate vitamin D activity. In fact, studies in several animal models such as the rat ureteral obstruction model, the 5/6 nephrectomy model and others, clearly show that VDR stimulation prevents both structural and functional changes in the heart and the kidney. Clinical trials are needed to validate the vitamin D potential benefits in chronic kidney disease and its associated cardiovascular risk.

Angiotensin-(1-7) abrogates angiotensin II-induced proliferation, migration and inflammation in VSMCs through inactivation of ROS-mediated PI3K/Akt and MAPK/ERK signaling pathways

The proliferation, migration and inflammation of vascular smooth muscle cells (VSMCs) contribute to the pathogenesis and progression of several cardiovascular diseases such as atherosclerosis and hypertension. Angiotensin (Ang)-(1–7) and Ang II are identified to be involved in regulating cardiovascular activity. The present study is designed to determine the interaction between Ang-(1–7) and Ang II on VSMCs proliferation, migration and inflammation as well as their underlying mechanisms. We found that Ang-(1–7) significantly suppressed the positive effects of Ang II on VSMCs proliferation, migration and inflammation, as well as on induction of the phosphorylation of Akt and ERK1/2 and increase of superoxide anion level and NAD(P)H oxidase activity in VSMCs, whereas Ang-(1–7) alone had no significant effects. This inhibitory effects of Ang-(1–7) were abolished by Mas receptor antagonist A-779. In addition, Ang II type 1 (AT₁) receptor antagonist losartan, but not A-779, abolished Ang II induced VSMCs proliferation, migration and inflammation responses. Furthermore, superoxide anion scavenger N-acetyl-L-cysteine (NAC) or NAD(P)H oxidase inhibitor apocynin inhibited Ang II-induced activation of Akt and ERK1/2 signaling. These results indicate that Ang-(1–7) antagonizes the Ang II-induced VSMC proliferation, migration and inflammation through activation of Mas receptor and then suppression of ROS-dependent PI3K/Akt and MAPK/ERK signaling pathways.

Analysis of Carotid color ultrasonography and high sensitive C-reactive protein in patients with atherosclerotic cerebral infarction

Objectives:

To detect the correlation between high-sensitivity-CRP, carotid plaque, neurological function and intima–media thickness, and help physicians in the diagnosis of atherosclerotic cerebral infarction.

Methods:

A total of 96 patients with the first onset of atherosclerotic cerebral infarction were included in the study from July 2013 to May 2015. The test of high-sensitivity-CRP, examination of carotid color ultrasonography and neurological function evaluation were carried out for all the participants.

Results:

Ninety-six patients were divided into carotid plaque group and non-plaque group according to the existence of a carotid plaque after carotid artery ultrasonography. The carotid plaque group was further subdivided into stable plaque and unstable plaque subgroups according to plaque characteristics. The age in two subgroups was significantly higher than the non-plaque group (p<0.05). The unstable plaque subgroup presented with the highest values in intima–media thickness and high-sensitivity-CRP level, followed by stable plaque subgroup and non-plaque group (p<0.05). With the nervous damage scale increase, the level of high-sensitivity-CRP increase significantly (p<0.05). In addition, there was significant correlation between NIHSS score and high-sensitivity-CRP in patients with atherosclerotic cerebral infarction (p<0.05).

Conclusion:

The level of high-sensitivity-CRP and intima–media thickness is closely associated with the development of carotid plaque, and high-sensitivity-CRP can be regarded as a high sensitive index in deciding the risk and prognosis of atherosclerotic cerebral infarction.

The relationship of the oleic acid level and ECHDC3 mRNA expression with the extent of coronary lesion

Background

The fatty acid profile is associated with the risk and progression of several diseases, probably via mechanisms including its influence on gene expression. We previously reported a correlation between ECHDC3 upregulation and the severity of acute coronary syndrome. Here, we assessed the relationship of serum fatty acid profile and ECHDC3 expression with the extent of coronary lesion.

Methods

Fifty-nine individuals aged 30 to 74 years and undergoing elective cinecoronariography for the first time were enrolled in the present study. The extent of coronary lesion was assessed by the Friesinger index and patients were classified as without lesion (n = 18), low lesion (n = 17), intermediate lesion (n = 17) and major lesion (n = 7). Serum biochemistry, fatty acid concentration, and ECHDC3 mRNA expression in blood were evaluated.

Results

Elevated serum levels of oleic acid and total monounsaturated fatty acids were observed in patients with low and intermediate lesion, when compared to patients without lesion (p < 0.05). ECHDC3 mRNA expression was 1.2 fold higher in patients with low lesion than in patients without lesion (p = 0.020), and 1.8 fold lower in patients with major lesion patients than in patients with low lesion (p = 0.023).

Conclusion

Increased levels of monounsaturated fatty acids, especially oleic acid, and ECHDC3 upregulation in patients with coronary artery lesion suggests that these are independent factors associated with the initial progression of cardiovascular disease.

Severe Brown Fat Lipoatrophy Aggravates Atherosclerotic Process in Male Mice

Obesity is one of the major risk factors for the development of cardiovascular diseases and is characterized by abnormal accumulation of adipose tissue, including perivascular adipose tissue (PVAT). However, brown adipose tissue (BAT) activation reduces visceral adiposity. To demonstrate that severe brown fat lipoatrophy might accelerate atherosclerotic process, we generated a new mouse model without insulin receptor (IR) in BAT and without apolipoprotein (Apo)E (BAT-specific IR knockout [BATIRKO];ApoE(-/-) mice) and assessed vascular and metabolic alterations associated to obesity. In addition, we analyzed the contribution of the adipose organ to vascular inflammation. Brown fat lipoatrophy induces visceral adiposity, mainly in gonadal depot (gonadal white adipose tissue [gWAT]), severe glucose intolerance, high postprandial glucose levels, and a severe defect in acute insulin secretion. BATIRKO;ApoE(-/-) mice showed greater hypertriglyceridemia than the obtained in ApoE(-/-) and hypercholesterolemia similar to ApoE(-/-) mice. BATIRKO;ApoE(-/-) mice, in addition to primary insulin resistance in BAT, also showed a significant decrease in insulin signaling in liver, gWAT, heart, aorta artery, and thoracic PVAT. More importantly, our results suggest that severe brown fat lipoatrophy aggravates the atherosclerotic process, characterized by a significant increase of lipid depots, atherosclerotic coverage, lesion size and complexity, increased macrophage infiltration, and proinflammatory markers expression. Finally, an increase of TNF-α and leptin as well as a decrease of adiponectin by BAT, gWAT, and thoracic PVAT might also be responsible of vascular damage. Our results suggest that severe brown lipoatrophy aggravates atherosclerotic process. Thus, BAT activation might protect against obesity and its associated metabolic alterations.

Fetopathies associated with exposure to angiotensin converting enzyme inhibitor from Tropaeolum majus L

The prevalence of the use of herbal medicines is on the rise across the world, especially amongst pregnant women. A fact that draws attention is that many species commonly used by pregnant women, including the Tropaeolum majus L. (Tropaeolaceae), also present inhibitory activity on the angiotensin-converting enzyme (ACE). Herein, we have investigated the effects of T. majus extract (HETM) on fetal development, evaluating its relationship with possible ACE inhibitory activity. Pregnant Wistar rats were treated with different HETM doses (3, 30 and 300 mg/kg/day) from gestational days 8-20. Rats were sacrificed on the day 20 of pregnancy and the following parameters were evaluated: clinical symptoms of maternal toxicity; maternal body weight; feed and water intake; maternal liver, kidney, and ovary weights, maternal ACE activity and aldosterone levels, live fetuses mean; dead fetuses percentage, fetus weight, and fetal malformation. All pregnant rats treated with high HETM doses showed significant reduction in plasma ACE activity accompanied by a decrease in serum aldosterone levels. Moreover, significant changes in fetal development were observed, including growth retardation and renal damage after 20 days of gestation. Thus, data presented demonstrate the significant effects of the use of HETM on fetal development during pregnancy.

The structural and functional effects of fine particulate matter from cooking oil fumes on rat umbilical cord blood vessels

A growing body of epidemiological evidence has supported the association between maternal exposure to airborne fine particulate matter (PM2.5) during pregnancy and adverse pregnancy outcomes. However, the specific biological mechanisms implicated in the causes of adverse pregnancy outcomes are not well defined. In this study, a pregnant rat model of exposure to different doses of cooking oil fumes (COFs)-derived PM2.5 by tail intravenous injection in different pregnant stages was established. The results indicated that exposure to COFs-derived PM2.5 was associated with adverse pregnancy outcomes, changed the structure of umbilical cord blood vessels, decreased the diameter and lumen area, and increased wall thickness. What's more, a significant increase of maximum contraction tension was observed in the early pregnancy high-dose exposure group and pregnant low-dose exposure group compared to the control group. Based on the maximum contraction tension, acetylcholine (ACh) did not induce vasodilation but caused a dose-dependent constriction, and there were significant differences in the two groups compared to the control group. Exposure to COFs-derived PM2.5 impaired the vasomotor function of umbilical veins by affecting the expression of NO and ET-1. This is the first study that evaluated the association of risk of adverse pregnancy outcomes and pregnant rats exposed to COFs-derived PM2.5 and primarily explored the potential mechanisms of umbilical cord blood vessels injury on a rat model. More detailed vitro and vivo studies are needed to further explore the mechanism in the future.

Renin-angiotensin system in ventilator-induced diaphragmatic dysfunction: Potential protective role of Angiotensin (1-7)

Ventilator-induced diaphragmatic dysfunction is a feared complication of mechanical ventilation that adversely affects the outcome of intensive care patients. Human and animal studies demonstrate atrophy and ultrastructural alteration of diaphragmatic muscular fibers attributable to increased oxidative stress, depression of the anabolic pathway regulated by Insulin-like growing factor 1 and increased proteolysis. The renin-angiotensin system, through its main peptide Angiotensin II, plays a major role in skeletal muscle diseases, mainly increasing oxidative stress and inducing insulin resistance, atrophy and fibrosis. Conversely, its counter-regulatory peptide Angiotensin (1-7) has a protective role in these processes. Recent data on rodent models show that renin-angiotensin system is activated after mechanical ventilation and that infusion of Angiotensin II induces diaphragmatic skeletal muscle atrophy. Given: (A) common pathways shared by ventilator-induced diaphragmatic dysfunction and skeletal muscle pathology induced by renin-angiotensin system, (B) evidences of an involvement of renin-angiotensin system in diaphragm atrophy and dysfunction, we hypothesize that renin-angiotensin system plays an important role in ventilator-induced diaphragmatic dysfunction, while Angiotensin (1-7) can have a protective effect on this pathological process. The activation of renin-angiotensin system in ventilator-induced diaphragmatic dysfunction can be demonstrated by quantification of its main components in the diaphragm of ventilated humans or animals. The infusion of Angiotensin (1-7) in an established rodent model of ventilator-induced diaphragmatic dysfunction can be used to test its potential protective role, that can be further confirmed with the infusion of Angiotensin (1-7) antagonists like A-779. Verifying this hypothesis can help in understanding the processes involved in ventilator-induced diaphragmatic dysfunction pathophysiology and open new possibilities for its prevention and treatment.

WITHDRAWN: Melatonin improves methamphetamine-induced blood brain barrier impairment through NADPH oxidase-2 in primary rat brain microvascular endothelium cells

The Publisher regrets that this article is an accidental duplication of an article that has already been published in 〈BRES, 1646 (2016) 182-192〉, 10.1016/j.brainres.2016.05.049. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

The emerging role of Toll-like receptor 4 in myocardial inflammation

Toll-like receptors (TLRs) are a family of pattern recognition receptors involved in cardiovascular diseases. Notably, numerous studies have demonstrated that TLR4 activates the expression of several of pro-inflammatory cytokine genes that play pivotal roles in myocardial inflammation, particularly myocarditis, myocardial infarction, ischemia-reperfusion injury, and heart failure. In addition, TLR4 is an emerging target for anti-inflammatory therapies. Given the significance of TLR4, it would be useful to summarize the current literature on the molecular mechanisms and roles of TLR4 in myocardial inflammation. Thus, in this review, we first introduce the basic knowledge of the TLR4 gene and describe the activation and signaling pathways of TLR4 in myocardial inflammation. Moreover, we highlight the recent progress of research on the involvement of TLR4 in myocardial inflammation. The information reviewed here may be useful to further experimental research and to increase the potential of TLR4 as a therapeutic target.

A novel sensor to estimate the prevalence of hypochlorous (HOCl) toxicity in individuals with type 2 diabetes and dyslipidemia

BACKGROUND

Oxidative stress is common in type 2 diabetes. It is characterised by increased levels of reactive oxygen species (ROS), of which hypochlorous acid (HOCl) is an important component. Type 2 diabetes is characterised not only by hyperglycemia, but also by dyslipidemia. It probably underlies both the development of diabetes and also resulting complications, like cardiovascular disease. We applied a novel fluoroprobe RHQ to estimate endogenous HOCl and myeloperoxidase (MPO) activity in diabetes and dyslipidemia.

METHODS

Our newly designed probe, RHQ (rhodamine-quinoline based chemodosimeter) is capable of estimating endogenous HOCl selectively out of the ROS components. Isolated leukocytes from study subjects were treated with DCFDA and monocytes and neutrophils with RHQ for estimating endogenous ROS and HOCl respectively. Plasma AOPP, an indicator of HOCl was also measured. We attempted to find out the key reasons of higher HOCl content in diabetic dyslipidemic subjects by quantitating endogenous hydrogen peroxide (H2O2) and myeloperoxidase (MPO) activity.

RESULTS

Isolated PBMCs from diabetic dyslipidemic subjects indicated enhanced ROS and HOCl generation followed by diabetic subjects without dyslipidemia and healthy controls. We explored increased production of H2O2 and enhanced enzymatic activity of myeloperoxidase (MPO) among diabetic dyslipidemic subjects (p<0.0001) resulting in higher HOCl content.

CONCLUSION

The hyperglycemic and hyperlipidemic challenges together enhance the production of HOCl and the fluoroprobe RHQ may be used as a novel diagnostic marker to evaluate the extent of this toxicity.

Serum lipid levels are positively correlated with lumbar disc herniation--a retrospective study of 790 Chinese patients

Background

Abnormal serum lipid levels have been shown to be associated with the occurrence of atherosclerosis, but little is known about the relationships of them with the risk of developing intervertebral disc degeneration (IVDD) in Chinese population.

Methods

We performed a case–control study to assess the relationship between serum lipid levels and lumbar disc degeneration. A total of 790 Chinese patients were recruited for this study at the time of hospitalization. We examined fasting serum lipid levels of total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C). 396 patients (235 men and 161 women; mean age: 41.07 years) underwent surgery for single-level lumbar disc herniation. A control group of 394 patients (225 men and 169 women; mean age: 42.1 years) underwent surgery for wounded lower limbs during the same period. Patients in the control group were collected randomly from among patients who were age- and sex-matched patients with the case group.

Results

Patients with lumbar disc herniation had significantly higher TC and LDL-C serum concentrations (P < 0.001 for both) than controls. Percentage of High-TC, High-TG, High-LDL-C, borderline High-TC and borderline High-LDL-C were significantly higher in the disc herniation group (P = 0.017, P = 0.002, P = 0.039, P =0.002 and P < 0.001, respectively). Ratios of TC/HDL-C and LDL-C/HDL-C were significantly associated with disc herniation (P < 0.001 for both). Logistic regression revealed that patients with higher serum LDL-C levels had a higher risk of disc herniation, in which odds ratio (OR) was 1.462 and confidence interval (CI) was 1.179 ~ 1.813. Moreover, patients with High-TG and borderline High-LDL-C had a higher probability of disc herniation (OR: 2.974, CI: 1.488 ~ 5.945, statistical power: 100 %; OR: 1.626, CI: 1.012 ~ 2.612, statistical power: 61.4 %, respectively). However, hyperlipidaemia did not seem to be associated with the herniated segment of the lumbar intervertebral disc (p = 0.374).

Conclusions

The present study suggests that dyslipidaemia may be associated with a higher risk of developing lumbar disc herniation. Serum lipid levels could be a useful predictor for intervertebral disc degeneration in Chinese population.

Endothelial Dysfunction and Inflammation: Immunity in Rheumatoid Arthritis

Inflammation, as a feature of rheumatoid arthritis (RA), leads to the activation of endothelial cells (ECs). Activated ECs induce atherosclerosis through an increased expression of leukocyte adhesion molecules. Endothelial dysfunction (ED) is recognized as a failure of endothelial repair mechanisms. It is also an early preclinical marker of atherosclerosis and is commonly found in RA patients. RA is now established as an independent cardiovascular risk factor, while mechanistic determinants of ED in RA are still poorly understood. An expanding body of study has shown that EC at a site of RA is both active participant and regulator of inflammatory process. Over the last decade, a role for endothelial dysfunction in RA associated with cardiovascular disease (CVD) has been hypothesized. At the same time, several maintenance drugs targeting this phenomenon have been tested, which has promising results. Assessment of endothelial function may be a useful tool to identify and monitor RA patients.

Influence of ACE I/D Polymorphism on Circulating Levels of Plasminogen Activator Inhibitor 1, D-Dimer, Ultrasensitive C-Reactive Protein and Transforming Growth Factor β1 in Patients Undergoing Hemodialysis

BACKGROUND

There is substantial evidence that chronic renal and cardiovascular diseases are associated with coagulation disorders, endothelial dysfunction, inflammation and fibrosis. Angiotensin-Converting Enzyme Insertion/Deletion polymorphism (ACE I/D polymorphism) has also be linked to cardiovascular diseases. Therefore, this study aimed to compare plasma levels of ultrassensible C-reactive protein (usCRP), PAI-1, D-dimer and TGF-β1 in patients undergoing HD with different ACE I/D polymorphisms.

METHODS

The study was performed in 138 patients at ESRD under hemodialysis therapy for more than six months. The patients were divided into three groups according to the genotype. Genomic DNA was extracted from blood cells (leukocytes). ACE I/D polymorphism was investigated by single polymerase chain reaction (PCR). Plasma levels of D-dimer, PAI-1 and TGF-β1 were measured by enzyme-linked immunosorbent assay (ELISA), and the determination of plasma levels of usCRP was performed by immunonephelometry. Data were analyzed by the software SigmaStat 2.03.

RESULTS

Clinical characteristics were similar in patients with these three ACE I/D polymorphisms, except for interdialytic weight gain. I allele could be associated with higher interdialytic weight gain (P = 0.017). Patients genotyped as DD and as ID had significantly higher levels of PAI-1 than those with II genotype. Other laboratory parameters did not significantly differ among the three subgroups (P = 0.033). Despite not reaching statistical significance, plasma levels of usCRP were higher in patients carrying the D allele.

CONCLUSION

ACE I/D polymorphisms could be associated with changes in the regulation of sodium, fibrinolytic system, and possibly, inflammation. Our data showed that high levels of PAI-1 are detected when D allele is present, whereas greater interdialytic gain is associated with the presence of I allele. However, further studies with different experimental designs are necessary to elucidate the mechanisms involved in these associations.

Thyroid Hormones, Oxidative Stress, and Inflammation

Inflammation and oxidative stress (OS) are closely related processes, as well exemplified in obesity and cardiovascular diseases. OS is also related to hormonal derangement in a reciprocal way. Among the various hormonal influences that operate on the antioxidant balance, thyroid hormones play particularly important roles, since both hyperthyroidism and hypothyroidism have been shown to be associated with OS in animals and humans. In this context, the nonthyroidal illness syndrome (NTIS) that typically manifests as reduced conversion of thyroxine (T₄) to triiodothyronine (T₃) in different acute and chronic systemic conditions is still a debated topic. The pathophysiological mechanisms of this syndrome are reviewed, together with the roles of deiodinases, the enzymes responsible for the conversion of T₄ to T₃, in both physiological and pathological situations. The presence of OS indexes in NTIS supports the hypothesis that it represents a condition of hypothyroidism at the tissue level and not only an adaptive mechanism to diseases.

Epidemiology and determinants of pruritus in pre-dialysis chronic kidney disease patients

PURPOSE

There are only a few small studies investigating chronic kidney disease-associated pruritus (CKD-P) in pre-dialysis chronic kidney disease (CKD). None of these has taken into account the associations of CKD-P with clinical features and laboratory data. We aimed to study prevalence of and clinical and laboratory associates of CKD-P in pre-dialysis CKD patients.

METHODS

A total of 402 consecutive stage 2-5 pre-dialysis CKD patients were included in this cross-sectional study. Pruritus was scored based on visual analog scale (VAS). Demographic and clinical features, comorbidities, smoking status and current medication use were recorded. 25 (OH) Vitamin D, urea, creatinine, uric acid, calcium, phosphorus, intact parathyroid hormone (PTH), magnesium, albumin, C-reactive protein (CRP), complete blood count and differential and other laboratory tests were studied for each participant.

RESULTS

This is the largest study conducted in pre-dialysis population with respect to pruritus and associated factors. The prevalence of CKD-P was 18.9%. Hemoglobin level was significantly lower, and eosinophil count and frequency of xerosis cutis were significantly higher in patients with CKD-P than those of patients without pruritus. However, there was no statistical difference between the pruritus and nonpruritus groups regarding vitamin D, PTH, calcium, phosphorus, neutrophil-to-lymphocyte ratio (NLR) and CRP.

CONCLUSIONS

CKD-P was almost present in one in every five pre-dialysis CKD patients. Interestingly, the prevalence was not affected by the stage of the CKD. For the first time, our results showed a significant association between CKD-P and peripheral eosinophilia and anemia. Besides this, xerosis cutis seems a determinant factor for CKD-P and its severity.

Protective effects of Arctium lappa L. root extracts (AREs) on high fat diet induced quail atherosclerosis

BACKGROUND

This study was designed to evaluate the protective effects of Arctium lappa L. root extracts (AREs) from different extraction methods (aqueous, ethanol, chloroform and flavone) on atherosclerosis.

METHODS

Quails (Coturnix coturnix) were subjected to high fat diet, with or without one of the four different AREs or positive control simvastatin. Blood samples were collected before treatment, after 4.5 weeks or ten weeks to assess lipid profile (Levels of total cholesterol (TC), Triacylglycerol (TG), low-density lipoprotein (LDL) and high-density lipoprotein (HDL)). After ten weeks, the serum levels of nitric oxide (NO) as well as antioxidant and pro-oxidative status (Levels of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), nicotinamide adenine dinucleotide phosphate (NADPH) and glutathione peroxidase (GSH-Px)) were measured. Furthermore, aortas were collected after ten weeks treatment, aorta lipid contents (TC, TG and LDL) were assessed, and histology was used to confirm atherosclerotic changes.

RESULTS

The results indicated that high fat diet significantly deteriorated lipid profile and antioxidant status in quail serum, while all the extracts significantly reverted the changes similar to simvastatin. Aorta lipid profile assessment revealed similar results. Histology on aortas from quails treated for ten weeks confirmed atherosclerotic changes in high fat diet group, while the extracts significantly alleviated the atherosclerotic changes similar to simvastatin. Among the different extracts, flavones fraction exerted best protective effects.

CONCLUSIONS

Our data suggest that the protective effects of AREs were medicated via hypolipidemic and anti-oxidant effects. Underlying molecular mechanisms are under investigation.

Diabetes and Body Mass Index Are Associated with Neuropathy and Prognosis in Colon Cancer Patients Treated with Capecitabine and Oxaliplatin Adjuvant Chemotherapy

BACKGROUND

There are few background data on the impact of clinical factors on neurotoxicity and prognosis in patients treated with adjuvant capecitabine and oxaliplatin (CAPOX) chemotherapy.

METHODS

102 stage II high-risk and stage III colorectal cancer patients were treated for 6 months with adjuvant CAPOX, then they were followed up. Associations between clinical variables, metabolic syndrome components, smoking and neurotoxicity were evaluated by the x03C7;2 test. The Kaplan-Meier product limit method was applied to graph disease-free survival (DFS). Univariate analysis was done with the log-rank test. Cox's proportional hazards regression was used to analyze the effect of several risk factors on DFS.

RESULTS

Significant associations were found between diabetes (p < 0.001), BMI (p = 0.01) and the occurrence of chronic neurotoxicity. After a median follow-up of 46 months, 14 patients (13.7%) had suffered recurrence. An analysis of the prognostic factors for DFS showed that prognosis is unfavorable for patients with high lymph-nodal involvement (HR: 5.23, p = 0.0007), diabetes (HR: 4.86; p = 0.03) and a BMI ≥25 (HR: 3.69, p = 0.002).

DISCUSSION

Common mediators in diabetes and obesity could be involved in peripheral neuropathy and in stimulating micro-metastases. Further studies are necessary to explain this interesting connection between diabetes, obesity and colon cancer.

Lipopolysaccharide-Induced Spatial Memory and Synaptic Plasticity Impairment Is Preventable by Captopril

Introduction. Renin-angiotensin system has a role in inflammation and also is involved in many brain functions such as learning, memory, and emotion. Neuroimmune factors have been proposed as the contributors to the pathogenesis of memory impairments. In the present study, the effect of captopril on spatial memory and synaptic plasticity impairments induced by lipopolysaccharide (LPS) was investigated. Methods. The rats were divided and treated into control (saline), LPS (1 mg/kg), LPS-captopril (LPS-Capto; 50 mg/kg captopril before LPS), and captopril groups (50 mg/kg) before saline. Morris water maze was done. Long-term potentiation (LTP) from CA1 area of hippocampus was assessed by 100 Hz stimulation in the ipsilateral Schaffer collateral pathway. Results. In the LPS group, the spent time and traveled path to reach the platform were longer than those in the control, while, in the LPS-Capto group, they were shorter than those in the LPS group. Moreover, the slope and amplitude of field excitatory postsynaptic potential (fEPSP) decreased in the LPS group, as compared to the control group, whereas, in the LPS-Capto group, they increased compared to the LPS group. Conclusion. The results of the present study showed that captopril improved the LPS-induced memory and LTP impairments induced by LPS in rats. Further investigations are required in order to better understand the exact responsible mechanism(s).

The Relationship Between High-Sensitivity C-Reactive Protein Levels and Left Ventricular Hypertrophy in Patients With Newly Diagnosed Hypertension

The authors aimed to evaluate the relationship between high-sensitivity C-reactive protein (hs-CRP) and presence of left ventricular hypertrophy and diastolic dysfunction in patients with hypertension. A total of 95 newly diagnosed hypertensive patients (mean age, 54±10 years) and 20 controls were included in this study. Patients were divided into four groups according to relative wall thickness as normal, concentric remodeling, concentric, and eccentric hypertrophy. hs-CRP was measured in all patients and serum hs-CRP level was shown to be increased in patients with hypertension compared with controls (0.57 mg/dL vs 0.25 mg/dL, respectively; P<.001). The hs-CRP level was highest in patients with concentric hypertrophy. When compared with controls, serum hs-CRP level was significantly higher in patients with concentric remodeling (0.61±0.3 mg/dL vs 0.43±0.5 mg/dL, P<.030) and concentric hypertrophy (0.69±0.3 mg/dL vs 0.43±0.5 mg/dL, P<.032). The present study shows that serum hs-CRP is significantly associated with left ventricular diastolic function and concentric hypertrophy in patients with hypertension.

Adipokines, diabetes and atherosclerosis: an inflammatory association

Cardiovascular diseases can be considered the most important cause of death in diabetic population and diabetes can in turn increase the risk of cardiovascular events. Inflammation process is currently recognized as responsible for the development and maintenance of diverse chronic diseases, including diabetes and atherosclerosis. Considering that adipose tissue is an important source of adipokines, which may present anti and proinflammatory effects, the aim of this review is to explore the role of the main adipokines in the pathophysiology of diabetes and atherosclerosis, highlighting the therapeutic options that could arise from the manipulation of these signaling pathways both in humans and in translational models.