Immunohistochemical analysis of paraoxonases and chemokines in arteries of patients with peripheral artery disease

Endothelial cell dysfunction: Implications for the pathogenesis of peripheral artery disease

Peripheral artery disease (PAD) is caused by occluded or narrowed arteries that reduce blood flow to the lower limbs. The treatment focuses on lifestyle changes, management of modifiable risk factors and vascular surgery. In this review we focus on how Endothelial Cell (EC) dysfunction contributes to PAD pathophysiology and describe the largely untapped potential of correcting endothelial dysfunction. Moreover, we describe current treatments and clinical trials which improve EC dysfunction and offer insights into where future research efforts could be made. Endothelial dysfunction could represent a target for PAD therapy.

Blood Vessel Detection Algorithm for Tissue Engineering and Quantitative Histology

Immunohistochemistry for vascular network analysis plays a fundamental role in basic science, translational research and clinical practice. However, identifying vascularization in histological tissue images is time consuming and markedly depends on the operator’s experience. In this study, we present “blood vessel detection—BVD”, an automatic algorithm for quantitative analysis of blood vessels in immunohistochemical images. BVD is based on extraction and analysis of low-level image features and spatial filtering techniques, which do not require a training phase. BVD algorithm performance was comparatively evaluated on histological sections from three different in vivo experiments. Collectively, 173 independent images were analyzed, and the algorithm's results were compared to those obtained by human operators. The developed BVD algorithm proved to be a robust and versatile tool, being able to quantify number, area, and spatial distribution of blood vessels within all three considered histologic datasets. BVD is provided as an open-source application working on different operating systems. BVD is supported by a user-friendly graphical interface designed to facilitate large-scale analysis.

Endothelial cell-derived pro-fibrotic factors increase TGF-β1 expression by smooth muscle cells in response to cycles of hypoxia-hyperoxia

BACKGROUND

The vascular pathology of peripheral artery disease (PAD) encompasses abnormal microvascular architecture and fibrosis in response to ischemia-reperfusion (I/R) cycles. We aimed to investigate the mechanisms by which pathological changes in the microvasculature direct fibrosis in the context of I/R.

METHODS

Primary human aortic endothelial cells (ECs) were cultured under cycles of normoxia-hypoxia (NH) or normoxia-hypoxia-hyperoxia (NHH) to mimic I/R. Primary human aortic smooth muscle cells (SMCs) were cultured and treated with media from the ECs.

FINDINGS

The mRNA and protein expression of the pro-fibrotic factors platelet derived growth factor (PDGF)-BB and connective tissue growth factor (CTGF) were significantly upregulated in ECs undergoing NH or NHH cycles. Treatment of SMCs with media from ECs undergoing NH or NHH cycles led to significant increases in TGF-β1, TGF-β pathway signaling intermediates, and collagen expression. Addition of neutralizing antibodies against PDGF-BB and CTGF to the media blunted the increases in TGF-β1 and collagen expression. Treatment of SMCs with PAD patient-derived serum also led to increased TGF-β1 levels.

INTERPRETATION

In an in-vitro model of I/R, which recapitulates the pathophysiology of PAD, increased secretion of PDGF-BB and CTGF by ECs was shown to be predominantly driving TGF-β1-mediated expression by SMCs. These cell culture experiments help elucidate the mechanism and interaction between ECs and SMCs in microvascular fibrosis associated with I/R. Thus, targeting these pro-fibrotic factors may be an effective strategy to combat fibrosis in response to cycles of I/R.

FUNDING

National Institute on Aging at the National Institutes of Health grant number R01AG064420.

RESEARCH IN CONTEXT

Evidence before this study: Previous studies in gastrocnemius biopsies from peripheral artery disease (PAD) patients showed that transforming growth factor beta 1 (TGF-β1), the most potent inducer of pathological fibrosis, is increased in the vasculature of PAD patients and correlated with collagen deposition. However, the exact cellular source of TGF-β1 remained unclear. Added value of this study: Exposing cells to cycles of normoxia-hypoxia-hyperoxia (NHH) resulted in pathological changes that are consistent with human PAD. This supports the idea that the use of NHH may be a reliable, novel in vitro model of PAD useful for studying associated pathophysiological mechanisms. Furthermore, pro-fibrotic factors (PDGF-BB and CTGF) released from endothelial cells were shown to induce a fibrotic phenotype in smooth muscle cells. This suggests a potential interaction between these cell types in the microvasculature that drives increased TGF-β1 expression and collagen deposition. Thus, targeting these pro-fibrotic factors may be an effective strategy to combat fibrosis in response to cycles of ischemia-reperfusion.

The Relevance of Noncoding DNA Variations of Paraoxonase Gene Cluster in Atherosclerosis-Related Diseases

The human paraoxonase (PON) gene cluster is comprised of three contiguous genes (PON1, PON2 and PON3) of presumably common origin coding three lactonases of highly similar structure and substrate specificity. The catalytic activity of PON proteins is directed toward artificial organophosphates and in physiological conditions toward thiolactones and oxidized phospholipids. Consequently, PON enzymes are regarded as an effective defense against oxidative stress and, as a result, against atherosclerosis development. Additionally, both PON's serum activity and its concentration are influenced by several polymorphic variations in coding and noncoding DNA regions of the PON gene cluster remaining in linkage disequilibrium. Hence, the genetic polymorphism of the PON gene cluster may contribute to atherosclerotic process progression or deceleration. In this review the authors analyzed the relevance of noncoding DNA polymorphic variations of PON genes in atherosclerosis-related diseases involving coronary and peripheral artery disease, stroke, diabetes mellitus, dementia and renal disease and concluded that the effect of PON gene cluster' polymorphism has a considerable impact on the course and outcome in these conditions. The following PON genetic variations may serve as additional predictors of the risk of atherosclerosis in selected populations and individuals.

TLR7/8 in the Pathogenesis of Parkinson's Disease

Neuroinflammation and autoimmune mechanisms have a key part in the pathogenesis of Parkinson’s disease (PD). Therefore, we evaluated the role of Toll-like receptors (TLRs) as a link between inflammation and autoimmunity in PD. An in vivo model of PD was performed by administration of 1-metil 4-fenil 1,2,3,6-tetraidro-piridina (MPTP) at the dose of 20 mg/kg every 2 h for a total administration of 80/kg, both in single Knock Out (KO) mice for TLR7, TLR 8, and TLR9 and in double KO mice for TLR 7/8^-/-. All animals were compared with WT animals used as a control group. All animals were sacrificed after 7 days form the first administration of MPTP. The genetic absence of TLR 7 and 8 modified the PD pathway, increasing the immunoreactivity for TH and DAT compared to PD groups and decreasing microglia and astrocytes activation. Moreover, the deletion of TLR7 and TLR8 significantly reduced T-cell infiltration in the substantia nigra and lymph nodes, suggesting a reduction of T-cell activation. Therefore, our result highlights a possibility that an immunotherapy approach, by using a dual antagonist of TLR 7 and 8, could be considered as a possible target to develop new therapies for Parkinson diseases.

Chemokine (C-C motif) ligand 2 and coronary artery disease: Tissue expression of functional and atypical receptors

Chemokines, particularly chemokine (C-C- motif) ligand 2 (CCL2), control leukocyte migration into the wall of the artery and regulate the traffic of inflammatory cells. CCL2 is bound to functional receptors (CCR2), but also to atypical chemokine receptors (ACKRs), which do not induce cell migration but can modify chemokine gradients. Whether atherosclerosis alters CCL2 function by influencing the expression of these receptors remains unknown. In a necropsy study, we used immunohistochemistry to explore where and to what extent CCL2 and related receptors are present in diseased arteries that caused the death of men with coronary artery disease compared with unaffected arteries. CCL2 was marginally detected in normal arteries but was more frequently found in the intima. The expression of CCL2 and related receptors was significantly increased in diseased arteries with relative differences among the artery layers. The highest relative increases were those of CCL2 and ACKR1. CCL2 expression was associated with a significant predictive value of atherosclerosis. Findings suggest the need for further insight into receptor specificity or activity and the interplay among chemokines. CCL2-associated conventional and atypical receptors are overexpressed in atherosclerotic arteries, and these may suggest new potential therapeutic targets to locally modify the overall anti-inflammatory response.

Laparoscopic sleeve gastrectomy reverses non-alcoholic fatty liver disease modulating oxidative stress and inflammation

BACKGROUND & AIMS

Hepatic alterations, such as in non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) are frequently associated with obesity. To investigate the molecular mechanisms of these alterations and to identify molecules that could be used as potential therapeutic targets, we investigated the modulation of hepatic indices of oxidative stress and inflammation in obese patients undergoing laparoscopic sleeve gastrectomy (LSG).

METHODS

Patients (n = 436) attending our obesity clinic underwent LSG for weight loss. We obtained a diagnostic intraoperative liver biopsy, and a sub-cohort (n = 120) agreed to a 1-year follow-up that included donation of blood samples and additional liver biopsies. Selected key molecules in blood and liver tissue were used to investigate the hepatic alterations in obesity, and their response to LSG.

RESULTS

One year post-surgery, the prevalence of diabetes, dyslipidemia and hypertension decreased significantly. LSG improved liver histology features in all patients. Improvement was greater in severe cases of NAFLD including those with steatohepatitis, bridging fibrosis or cirrhosis. Significant pre-surgery differences in plasma, and liver markers of oxidative stress and inflammation (including chemokine C-C motif ligand 2, paraoxonase-1, galectin-3, and sonic hedgehog) were observed between patients with, and those without, NASH; post-surgery indicated consistent improvements in these parameters.

CONCLUSION

Our study shows that the histology and liver function of patients with morbid obesity are significantly improved after LSG via mechanisms that involve the reduction of oxidative stress and inflammatory processes. These data encourage the use of LSG as a therapeutic option to improve, or resolve, NAFLD.

N-Palmitoylethanolamide-Oxazoline Protects against Middle Cerebral Artery Occlusion Injury in Diabetic Rats by Regulating the SIRT1 Pathway

Diabetes causes various macrovascular and microvascular alterations, often culminating in major clinical complications (first of all, stroke) that lack an effective therapeutic intervention. N-palmitoylethanolamide-oxazoline (PEA-OXA) possesses anti-inflammatory and potent neuroprotective effects. Although recent studies have explained the neuroprotective properties of PEA-OXA, nothing is known about its effects in treating cerebral ischemia. Methods: Focal cerebral ischemia was induced by transient middle cerebral artery occlusion (MCAo) in the right hemisphere. Middle cerebral artery (MCA) occlusion was provided by introducing a 4–0 nylon monofilament (Ethilon; Johnson & Johnson, Somerville, NJ, USA) precoated with silicone via the external carotid artery into the internal carotid artery to occlude the MCA. Results: A neurological severity score and infarct volumes were carried out to assess the neuroprotective effects of PEA-OXA. Moreover, we observed PEA-OXA-mediated improvements in tissue histology shown by a reduction in lesion size and an improvement in apoptosis level (assessed by caspases, Bax, and Bcl-2 modulation and a TUNEL assay), which further supported the efficacy of PEA-OXA therapy. We also found that PEA-OXA treatment was able to reduce mast cell degranulation and reduce the MCAo-induced expression of NF-κB pathways, cytokines, and neurotrophic factors. Conclusions: based on these findings, we propose that PEA-OXA could be useful in decreasing the risk of impairment or improving function in ischemia/reperfusion brain injury-related disorders.

Oxidative Stress in Peripheral Arterial Disease (PAD) Mechanism and Biomarkers

Hemodynamic dysfunction mainly characterizes pathophysiology of peripheral arterial disease (PAD) leading to chronic ischemia. Hemodynamic dysfunction is the origin of intermittent claudication (chronic PAD) or of critical limb ischemia (very severe PAD). Notably, it is well known that oxidative stress (OxS) plays a pathophysiological role in PAD. The higher production of reactive oxygen species (ROS) from OxS and reduced redox capability are two crucial players in initiating and progressing PAD. A number of biomarkers highlight OxS and monitor it in PAD. The present review summarizes data on OxS, on biomarkers available to mark OxS occurrence and to monitor on PAD progression, as well as to evaluate the effects treatments in PAD patients. In conclusion, by detailing OxS and its biomarkers, we hope to encourage more studies to focus on drugs which combat OxS and inflammation.

TLR4 absence reduces neuroinflammation and inflammasome activation in Parkinson's diseases in vivo model

Parkinson's disease (PD) is a progressive, disabling neurodegenerative disorder. It has been shown Toll like receptor (TLR) 4-deficient mice protect against MPTP toxicity, suggesting that dopaminergic cell death is TLR4-dependent. The aim of this study was to demonstrate, in an in vivo model of PD, how TLR4 plays its important role in the pathogenesis of PD by using MPTP neurotoxin model (4 × 20 mg/kg, 2 h apart, i.p). Our experiments have demonstrated that the absence of TLR4 prevented dopamine depletion, increased tyrosine hydroxylase and dopamine transporter activities and reduced the number of α-synuclein-positive neurons. The absence of TLR4 also had an impact on inflammatory processes, modulating the transcription factors NF-κB p65 and AP-1, and reducing astrogliosis. Importantly, we demonstrated that the absence of TLR4 modulated inflammosome pathway. Moreover, it has been shown that TLR4 modulated motor and non-motor symptoms typical of PD. Our results clearly demonstrated that absence of TLR4 reduces the development of neuroinflammation associated with PD through NF-κB, AP-1 and inflammasome pathways modulation; therefore, TLR4 could be considered as an encouraging therapeutic target in neurodegenerative disorders.

Treatment With a Flavonoid-Rich Fraction of Bergamot Juice Improved Lipopolysaccharide-Induced Periodontitis in Rats

Objective: In this study, we investigated the effects of a flavonoid-rich fraction of Bergamot juice (BJe) in rats subjected to experimental periodontitis induced by a single intragingival injection of lipopolysaccharides (LPS).

Main Methods: Periodontitis was induced by a single intragingival injection of 1 μl LPS (10 μg/μl) derived from Salmonella typhimurium in sterile saline solution. The injection was made in the mesolateral side at the interdental papilla between the first and the second molar. Fourteen days after LPS injection, we performed radiographic analyses and then we surgically removed the gingivomucosal tissue surrounding the mandibular first molar for histological, immunohistochemical and molecular analysis.

Results: LPS significantly induced oedema, tissue damage and increased neutrophil infiltration. At molecular level, we found increased NF-κB translocation as well as raised both TNF-α and IL-1β expression, other than modulation of apoptosis-associated proteins. Moreover, the increased myeloperoxidase activity was associated with up-regulation of adhesion molecules. Immunohistochemical analysis for nitrotyrosine and poly ADP-ribose displayed an intense staining in the gingivomucosal tissue. Oral administration of BJe for 14 consecutive days reduced tissue injury and several markers of gingival inflammation including nuclear NF-κB translocation, cytokines expression, myeloperoxidase activity and the expression of some adhesion molecules such as ICAM and P-selectin. BJe also decreased both nitrosative stress and PARP positive staining. Moreover, it caused down-regulation of Bax and up-regulation of Bcl-2 expression.

Conclusion: Our findings demonstrate that BJe improves LPS-induced periodontitis in rats by reducing the typical markers of inflammation, thus suggesting its potential in the treatment of periodontal diseases.

Attenuation of oxidative stress-induced lesions in skeletal muscle in a mouse model of obesity-independent hyperlipidaemia and atherosclerosis through the inhibition of Nox2 activity

Obesity leading to hyperlipidaemia and atherosclerosis is recognised to induce morphological and metabolic changes in many tissues. However, hyperlipidaemia can occur in the absence of obesity. The impact of the latter scenario on skeletal muscle and liver is not understood sufficiently. In this regard, we used the Apolipoprotein E-deficient (ApoE^-/-) mouse model, an established model of hyperlipidaemia and atherosclerosis, that does not become obese when subjected to a high-fat diet, to determine the impact of Western-type diet (WD) and ApoE deficiency on skeletal muscle morphological, metabolic and biochemical properties. To establish the potential of therapeutic targets, we further examined the impact of Nox2 pharmacological inhibition on skeletal muscle redox biology. We found ectopic lipid accumulation in skeletal muscle and the liver, and altered skeletal muscle morphology and intramuscular triacylglycerol fatty acid composition. WD and ApoE deficiency had a detrimental impact in muscle metabolome, followed by perturbed gene expression for fatty acid uptake and oxidation. Importantly, there was enhanced oxidative stress in the skeletal muscle and development of liver steatosis, inflammation and oxidative protein modifications. Pharmacological inhibition of Nox2 decreased reactive oxygen species production and protein oxidative modifications in the muscle of ApoE^-/- mice subjected to a Western-type diet. This study provides key evidence to better understand the pathophysiology of skeletal muscle in the context of hyperlipidaemia and atherosclerosis and identifies Nox2 as a potential target for attenuating oxidative stress in skeletal muscle in a mouse model of obesity-independent hyperlipidaemia.

Trace Elements and Paraoxonase-1 Activity in Lower Extremity Artery Disease

Oxidative stress and inflammation are candidate mechanisms to explain the potential role of exposure to metals and reduced activity of paraoxonase-1 (PON1) in age-related diseases. Both may be risk factors contributing to atherosclerosis. In the present study, inductively coupled mass spectrometry was used to explore multiple trace elements, while in-house methods were employed to measure PON1-related variables in patients with lower extremity artery disease (LEAD). Healthy controls were matched for sex, age, body weight, and relevant genotype variants. Serum concentrations of As, Ba, Cu, and Sr were higher in patients than those in controls, with a strong predictive ability to discriminate between groups. Differences in serum Pb, Cd, and Zn were negligible. Serum Cu increased when the disease was more severe, but a negative trend was noted for serum As, B, Ba, and Zn. The only variable associated with ankle-brachial index was serum Zn. Serum PON1 activity was significantly lower in LEAD patients. When the ability of serum trace elements to modulate PON1 activity was explored, the analysis revealed a unique association with serum Zn. The current results strongly suggest that Zn may have a protective effect in non-coronary atherosclerosis and indicate that this element may exert its anti-inflammatory and antioxidant functions through interactions with PON1 activity. These findings deserve confirmation and further research. In particular, the periodic evaluation of serum trace elements and the prescription of Zn supplements are easy measures to implement and that can improve the treatment of patients with LEAD.

Plasma Energy-Balance Metabolites Discriminate Asymptomatic Patients with Peripheral Artery Disease

Peripheral artery disease (PAD) is a common disease affecting 20-25% of population over 60 years old. Early diagnosis is difficult because symptoms only become evident in advanced stages of the disease. Inflammation, impaired metabolism, and mitochondrial dysfunction predispose to PAD, which is normally associated with other highly prevalent and related conditions, such as diabetes, dyslipidemia, and hypertension. We have measured energy-balance-associated metabolite concentrations in the plasma of PAD patients segregated by the severity of the disease and in plasma of healthy volunteers using a quantitative and targeted metabolomic approach. We found relevant associations between several metabolites (3-hydroxybutirate, aconitate, (iso)citrate, glutamate, and serine) with markers of oxidative stress and inflammation. Metabolomic profiling also revealed that (iso)citrate and glutamate are metabolites with high ability to discriminate between healthy participants and PAD patients without symptoms. Collectively, our data suggest that metabolomics provide significant information on the pathogenesis of PAD and useful biomarkers for the diagnosis and assessment of progression.

Sodium Butyrate Exerts Neuroprotective Effects in Spinal Cord Injury

Sodium butyrate (SB) is a dietary microbial fermentation product and serves as an important neuromodulator in the central nervous system. Recent experimental evidence has suggested potential therapeutic applications for butyrate, including its utility in treating metabolic and inflammatory diseases. The aim of the present study was to evaluate the potential beneficial effects of SB in a mouse model of spinal cord injury (SCI) and its possible mechanism of action. SCI was induced by extradural compression for 1 min of the spinal cord at the T6-7 level using an aneurysm clip, and SB (10-30-100 mg/kg) was administered by oral gavage 1 and 6 h after SCI. For locomotor activity, study mice were treated with SB once daily for 10 days. Morphological examination was performed by light microscopy through hematoxylin-eosin (H&E) staining. In addition, NF-κB, IκB-α, COX-2, and iNOS expressions were assayed by western blot analysis and IL-1β and TNF-α levels by immunohistochemistry analysis. The results showed that SB treatment significantly ameliorated histopathology changes and improved recovery of motor function changes in spinal cord injury in a dose-dependent manner. Moreover, we demonstrated that SB modulated the NF-κB pathway showing a significant reduction in cytokine expression. Thus, this study showed that SB exerts neuroprotective effects anti-inflammatory properties following spinal cord injury suggesting that SB may serve as a potential candidate for future treatment of spinal cord injury.

2-Pentadecyl-2-Oxazoline Reduces Neuroinflammatory Environment in the MPTP Model of Parkinson Disease

Current pharmacological management of Parkinson disease (PD) does not provide for disease modification, but addresses only symptomatic features. Here, we explore a new approach to neuroprotection based on the use of 2-pentadecyl-2-oxazoline (PEA-OXA), the oxazoline derivative of the fatty acid amide signaling molecule palmitoylethanolamide (PEA), in an experimental model of PD. Daily oral treatment with PEA-OXA (10 mg/kg) significantly reduced behavioral impairments and neuronal cell degeneration of the dopaminergic tract induced by four intraperitoneal injections of the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) on 8-week-old male C57 mice. Moreover, PEA-OXA treatment prevented dopamine depletion, increased tyrosine hydroxylase and dopamine transporter activities, and decreased α-synuclein aggregation in neurons. PEA-OXA treatment also diminished nuclear factor-κB traslocation, cyclooxygenase-2, and inducible nitric oxide synthase expression and through upregulation of the nuclear factor E2-related factor 2 pathway, induced activation of Mn-superoxide dismutase and heme oxygenase-1. Further, PEA-OXA modulated microglia and astrocyte activation and preserved microtubule-associated protein-2 alterations. In conclusion, pharmacological activation of nuclear factor E2-related factor 2 pathways with PEA-OXA may be effective in the future therapy of PD.

Assessment of extracellular matrix-related biomarkers in patients with lower extremity artery disease

BACKGROUND

The prevalence of lower extremity artery disease (LEAD) is high (20%-25%) in the population older than 65 years, but patients are seldom identified until the disease is advanced. Circulating markers of disease activity might provide patients with a key opportunity for timely treatment. We tested the hypothesis that measuring blood-specific fragments generated during degradation of the extracellular matrix (ECM) could provide further insight into the pathophysiologic mechanism of arterial remodeling.

METHODS

The protein profile of diseased arteries from patients undergoing infrainguinal limb revascularization was assessed by a liquid chromatography and tandem mass spectrometry, nontargeted proteomic approach. The information retrieved was the basis for measurement of neoepitope fragments of ECM proteins in the blood of 195 consecutive patients with LEAD by specific enzyme-linked immunosorbent assays.

RESULTS

Histologic and proteomic analyses confirmed the structural disorganization of affected arteries. Fourteen of 81 proteins were identified as differentially expressed in diseased arteries with respect to healthy tissues. Most of them were related to ECM components, and the difference in expression was used in multivariate analyses to establish that severe arterial lesions in LEAD patients have a specific proteome. Analysis of neoepitope fragments in blood revealed that fragments of versican and collagen type IV, alone or in combination, segregated patients with mild to moderate symptoms (intermittent claudication, Fontaine I-II) from those with severe LEAD (critical limb ischemia, Fontaine III-IV).

CONCLUSIONS

We propose noninvasive candidate biomarkers with the ability to be clinically useful across the LEAD spectrum.

Crossroads between peripheral atherosclerosis, western-type diet and skeletal muscle pathophysiology: emphasis on apolipoprotein E deficiency and peripheral arterial disease

Atherosclerosis is a chronic inflammatory process that, in the presence of hyperlipidaemia, promotes the formation of atheromatous plaques in large vessels of the cardiovascular system. It also affects peripheral arteries with major implications for a number of other non-vascular tissues such as the skeletal muscle, the liver and the kidney. The aim of this review is to critically discuss and assimilate current knowledge on the impact of peripheral atherosclerosis and its implications on skeletal muscle homeostasis. Accumulating data suggests that manifestations of peripheral atherosclerosis in skeletal muscle originates in a combination of increased i)-oxidative stress, ii)-inflammation, iii)-mitochondrial deficits, iv)-altered myofibre morphology and fibrosis, v)-chronic ischemia followed by impaired oxygen supply, vi)-reduced capillary density, vii)- proteolysis and viii)-apoptosis. These structural, biochemical and pathophysiological alterations impact on skeletal muscle metabolic and physiologic homeostasis and its capacity to generate force, which further affects the individual's quality of life. Particular emphasis is given on two major areas representing basic and applied science respectively: a)-the abundant evidence from a well-recognised atherogenic model; the Apolipoprotein E deficient mouse and the role of a western-type diet and b)-on skeletal myopathy and oxidative stress-induced myofibre damage from human studies on peripheral arterial disease. A significant source of reactive oxygen species production and oxidative stress in cardiovascular disease is the family of NADPH oxidases that contribute to several pathologies. Finally, strategies targeting NADPH oxidases in skeletal muscle in an attempt to attenuate cellular oxidative stress are highlighted, providing a better understanding of the crossroads between peripheral atherosclerosis and skeletal muscle pathophysiology.

Galectin-3 in Peripheral Artery Disease. Relationships with Markers of Oxidative Stress and Inflammation

Galectin-3 is a modulator of oxidative stress, inflammation, and fibrogenesis involved in the pathogenesis of vascular diseases. The present study sought to characterize, in patients with peripheral artery disease (PAD), the localization of galectin-3 in arterial tissue, and to analyze the relationships between the circulating levels of galectin-3 and oxidative stress and inflammation. It also sought to compare the diagnostic accuracy of galectin-3 with that of other biochemical markers of this disease. We analyzed femoral or popliteal arteries from 50 PAD patients, and four control arteries. Plasma from 86 patients was compared with that from 72 control subjects. We observed differences in the expression of galectin-3 in normal arteries, and arteries from patients with PAD, with a displacement of the expression from the adventitia to the media, and the intima. In addition, plasma galectin-3 concentration was increased in PAD patients, and correlated with serologic markers of oxidative stress (F2-isoprostanes), and inflammation [chemokine (C−C motif) ligand 2, C-reactive protein, β-2-microglobulin]. We conclude that the determination of galectin-3 has good diagnostic accuracy in the assessment of PAD and compares well with other analytical parameters currently in use.

Biochemical indices of oxidative stress and inflammation in the evaluation of peripheral artery disease

BACKGROUND

The aims of this study were: (1) to investigate changes in indices of oxidative stress and inflammation in the evaluation of peripheral artery disease (PAD); (2) to compare the diagnostic efficacy of these parameters with that of classical clinical laboratory routine parameters.

DESIGN AND METHODS

We studied 115 patients with PAD and 300 healthy volunteers.

RESULTS

PAD patients had significantly increased circulating concentrations of F2-isoprostanes, protein carbonyls, chemokine (C-C motif) ligand 2 (CCL2), high-sensitivity C-reactive protein (hs-CRP), β-2-microglobulin (B2M), and decreased paraoxonase-1 (PON1) levels. When patients were classified according to the Fontaine score, we observed important increases in plasma F2-isoprostanes and CCL2 that appeared in milder stages of the disease, and remained so at similar levels in more advanced stages; almost no overlapping with the control group was noted. Receiver operating characteristics analysis comparing patients and controls revealed that the areas under the curve for F2-isoprostanes and CCL2 approached unity [0.999 (0.998-1.000) and 0.993 (0.985-1.000)], respectively, and significantly higher to those of the other measured parameters.

CONCLUSION

Our data suggest that F2-isoprostanes and CCL2 measurements may be useful tools for the diagnosis of PAD.

Paraoxonase-1 overexpression prevents experimental abdominal aortic aneurysm progression

Decreased paraoxonase-1 (PON1) activity is associated with human and experimental abdominal aortic aneurysm (AAA). Overexpression of PON1 protected mice from AAA development induced by elastase, decreasing oxidative stress, apoptosis and inflammation. PON1 may provide a novel therapeutic target for AAA prevention.