scholarly journals The contribution of paraoxonase 1 and myeloperoxidase to HDL-cholesterol functionality

2016 ◽  
Vol 8 (1) ◽  
pp. 51-57 ◽  
Author(s):  
Marzena Malara ◽  
Anna Kęska ◽  
Grażyna Lutosławska
Keyword(s):  
Ldl Cholesterol ◽  
Scientific Evidence ◽  
Protective Action ◽  
Hdl Cholesterol ◽  
Protective Role ◽  
Plasma Lipoproteins ◽  
Paraoxonase 1 ◽  
Increased Risk

SummaryThe purpose of this study was to analyse the scientific evidence concerning the effects of two enzymes – paraoxonase 1 and myeloperoxidase – on the functions of HDL-cholesterol. It is well documented that disturbed circulating lipoproteins (a high total and high LDL-cholesterol, and low HDL-cholesterol) bring about atherosclerosis and an increased risk of cardiovascular disease (CVD) which is recognised as the main cause of death all around the world. In consequence, numerous studies have focused on procedures which will improve the plasma lipoproteins profile by decreasing the total cholesterol and the LDL-cholesterol (LDL-C) and increasing the HDL-cholesterol (HDL-C). However, the anti-atherogenic role of HDL-C has been challenged in studies showing that genetically elevated HDL-cholesterol does not offer protection against CVD. Moreover, it has been found that raising the circulating HDL-cholesterol fails to reduce atherosclerosis. The doubts concerning the protective role of HDL-C have been supported by in vitro studies which indicate that the HDL-C from patients with atherosclerosis does not have a protective action, but does stimulate inflammation and free radical synthesis. The above data suggests that HDL-C, commonly recognised as protective against atherosclerosis, in some circumstances becomes pro-atherogenic, and is thus dysfunctional. Our review focuses on two enzymes – paraoxonase 1 (PON1) and myeloperoxidase (MPO) – which markedly affect the properties of HDL-C and contribute to its anti – or pro-atherogenic activity. Moreover, the effects of the diet and physical activity on PON1 and MPO are summarised with respect to the HDL-C functionality.

scholarly journals The Role of Oestrogen and Other Hormones in the Pathophysiology and Treatment of Schizophrenia

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Emily Hayes ◽  
Emorfia Gavrilidis ◽  
Jayashri Kulkarni
Keyword(s):  
Scientific Evidence ◽  
Protective Role ◽  
Mental Illnesses ◽  
Preclinical Research ◽  
Novel Therapeutic Strategies ◽  
Randomised Controlled ◽  
Serious Mental Illnesses

The theory that many serious mental illnesses, in particular psychoses such as schizophrenia, may have a significant hormonal aetiological component is fast gaining popularity and the support of scientific evidence. Oestrogen in particular has been substantially investigated as a potential mediator of brain function in schizophrenia. Epidemiological and life-cycle data point to significant differences in the incidence and course of schizophrenia between men and women suggests a protective role of oestrogen.In vitroandin vivopreclinical research confirms oestradiol’s interactions with central neurotransmitter systems implicated in the pathogenesis of schizophrenia, while results from randomised controlled trials investigating the antipsychotic potential of oestrogen have been positive. Research into other neuroactive hormones with possible effects on mental state is a rapidly evolving field that may hold new promise. Given that schizophrenia and related psychoses are pervasive and debilitating conditions for which currently available treatments are often only partially effective and entail a high risk of serious side-effects, novel therapeutic strategies are needed. The literature reviewed in this paper suggests that hormones such as oestrogen could be a viable option, and it is hoped that with further research and larger trials, the oestrogen hypothesis can be translated into effective clinical practice.

scholarly journals Crosstalk Between Adipokines and Paraoxonase 1: A New Potential Axis Linking Oxidative Stress and Inflammation

Antioxidants ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 287 ◽  
Author(s):  
Veronica Tisato ◽  
Arianna Romani ◽  
Elisa Tavanti ◽  
Elisabetta Melloni ◽  
Daniela Milani ◽  
...  
Keyword(s):  
Density Lipoprotein ◽  
Hdl Cholesterol ◽  
Paraoxonase 1 ◽  
Pon1 Activity ◽  
Necrosis Factor Alpha ◽  
Monocyte Chemoattractant Protein 1 ◽  
Endogenous Factors ◽  
Factor Alpha

Paraoxonase 1 (PON1) is a high-density lipoprotein (HDL)-associated protein that endows its carrier with (lipo-)lactonase-dependent antioxidative features. Low levels of PON1 activity have been observed in association with obesity, a major risk factor for cardiovascular disease (CVD). Considering the well-recognized atheroprotective role of PON1, exogenous/endogenous factors that might modulate its levels/activity are raising great interest. Since adipokines represent a molecular link between obesity and CVD, we here explored the possible impact of these substances on PON1 activity/expression. The levels of interleukin (IL)-6, IL-8, tumor necrosis factor alpha, monocyte chemoattractant protein-1, hepatocyte growth factor, resistin, leptin, and adiponectin were measured along with arylesterase, paraoxonase, and lactonase activities of PON1 in 107 postmenopausal women. Moreover, the direct effect of resistin on PON1 expression was evaluated in vitro. Multivariate analysis revealed that only resistin was significantly and inversely correlated with PON1-lactonase activities (r = −0.346, p < 0.001) regardless of confounding factors such as age or HDL-cholesterol. It is worth noting that no statistical link was found between adipokine and arylesterase or paraoxonase, the two promiscuous activities of PON1. Notably, resistin down-regulated PON1 expression occurred in hepatocellular carcinoma cultures. Our study suggests that resistin might be a negative modulator of PON1 expression and anti-oxidative activity.

scholarly journals The Novel Role of PGC1α in Bone Metabolism

2021 ◽  
Vol 22 (9) ◽  
pp. 4670
Author(s):  
Cinzia Buccoliero ◽  
Manuela Dicarlo ◽  
Patrizia Pignataro ◽  
Francesco Gaccione ◽  
Silvia Colucci ◽  
...  
Keyword(s):  
Bone Metabolism ◽  
Osteoblastic Differentiation ◽  
In Vivo Studies ◽  
Peroxisome Proliferator ◽  
Sirtuin 3 ◽  
Peroxisome Proliferator Activated Receptor ◽  
Increased Risk

Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) is a protein that promotes transcription of numerous genes, particularly those responsible for the regulation of mitochondrial biogenesis. Evidence for a key role of PGC1α in bone metabolism is very recent. In vivo studies showed that PGC1α deletion negatively affects cortical thickness, trabecular organization and resistance to flexion, resulting in increased risk of fracture. Furthermore, in a mouse model of bone disease, PGC1α activation stimulates osteoblastic gene expression and inhibits atrogene transcription. PGC1α overexpression positively affects the activity of Sirtuin 3, a mitochondrial nicotinammide adenina dinucleotide (NAD)-dependent deacetylase, on osteoblastic differentiation. In vitro, PGC1α overexpression prevents the reduction of mitochondrial density, membrane potential and alkaline phosphatase activity caused by Sirtuin 3 knockdown in osteoblasts. Moreover, PGC1α influences the commitment of skeletal stem cells towards an osteogenic lineage, while negatively affects marrow adipose tissue accumulation. In this review, we will focus on recent findings about PGC1α action on bone metabolism, in vivo and in vitro, and in pathologies that cause bone loss, such as osteoporosis and type 2 diabetes.

scholarly journals Increased Remnant Cholesterol Explains Part of Residual Risk of All-Cause Mortality in 5414 Patients with Ischemic Heart Disease

2016 ◽  
Vol 62 (4) ◽  
pp. 593-604 ◽  
Author(s):  
Anne-Marie K Jepsen ◽  
Anne Langsted ◽  
Anette Varbo ◽  
Lia E Bang ◽  
Pia R Kamstrup ◽  
...  
Keyword(s):  
Heart Disease ◽  
Ischemic Heart Disease ◽  
Ldl Cholesterol ◽  
Hdl Cholesterol ◽  
Hazard Ratio ◽  
Residual Risk ◽  
Ischemic Heart ◽  
Increased Risk ◽  
All Cause Mortality ◽  
Remnant Cholesterol

Abstract BACKGROUND Increased concentrations of remnant cholesterol are causally associated with increased risk of ischemic heart disease. We tested the hypothesis that increased remnant cholesterol is a risk factor for all-cause mortality in patients with ischemic heart disease. METHODS We included 5414 Danish patients diagnosed with ischemic heart disease. Patients on statins were not excluded. Calculated remnant cholesterol was nonfasting total cholesterol minus LDL and HDL cholesterol. During 35836 person-years of follow-up, 1319 patients died. RESULTS We examined both calculated and directly measured remnant cholesterol; importantly, however, measured remnant cholesterol made up only 9% of calculated remnant cholesterol at nonfasting triglyceride concentrations &lt;1 mmol/L (89 mg/dL) and only 43% at triglycerides &gt;5 mmol/L (443 mg/dL). Multivariable-adjusted hazard ratios for all-cause mortality compared with patients with calculated remnant cholesterol concentrations in the 0 to 60th percentiles were 1.2 (95% CI, 1.1–1.4) for patients in the 61st to 80th percentiles, 1.3 (1.1–1.5) for the 81st to 90th percentiles, 1.5 (1.1–1.8) for the 91st to 95th percentiles, and 1.6 (1.2–2.0) for patients in the 96th to 100th percentiles (trend, P &lt; 0.001). Corresponding values for measured remnant cholesterol were 1.0 (0.8–1.1), 1.2 (1.0–1.4), 1.1 (0.9–1.5), and 1.3 (1.1–1.7) (trend, P = 0.006), and for measured LDL cholesterol 1.0 (0.9–1.1), 1.0 (0.8–1.2), 1.0 (0.8–1.3), and 1.1 (0.8–1.4) (trend, P = 0.88). Cumulative survival was reduced in patients with calculated remnant cholesterol ≥1 mmol/L (39 mg/dL) vs &lt;1 mmol/L [log-rank, P = 9 × 10−6; hazard ratio 1.3 (1.2–1.5)], but not in patients with measured LDL cholesterol ≥3 mmol/L (116 mg/dL) vs &lt;3 mmol/L [P = 0.76; hazard ratio 1.0 (0.9–1.1)]. CONCLUSIONS Increased concentrations of both calculated and measured remnant cholesterol were associated with increased all-cause mortality in patients with ischemic heart disease, which was not the case for increased concentrations of measured LDL cholesterol. This suggests that increased concentrations of remnant cholesterol explain part of the residual risk of all-cause mortality in patients with ischemic heart disease.

scholarly journals Genotoxicity and inflammatory potential of stainless steel welding fume particles: an in vitro study on standard vs Cr(VI)-reduced flux-cored wires and the role of released metals

2021 ◽  
Author(s):  
Sarah McCarrick ◽  
Valentin Romanovski ◽  
Zheng Wei ◽  
Elin M. Westin ◽  
Kjell-Arne Persson ◽  
...  
Keyword(s):  
Dna Damage ◽  
In Vitro Study ◽  
Human Monocyte ◽  
Welding Fumes ◽  
Welding Fume ◽  
Increased Risk ◽  
Underlying Mechanisms ◽  
Cored Wires

AbstractWelders are daily exposed to various levels of welding fumes containing several metals. This exposure can lead to an increased risk for different health effects which serves as a driving force to develop new methods that generate less toxic fumes. The aim of this study was to explore the role of released metals for welding particle-induced toxicity and to test the hypothesis that a reduction of Cr(VI) in welding fumes results in less toxicity by comparing the welding fume particles of optimized Cr(VI)-reduced flux-cored wires (FCWs) to standard FCWs. The welding particles were thoroughly characterized, and toxicity (cell viability, DNA damage and inflammation) was assessed following exposure to welding particles as well as their released metal fraction using cultured human bronchial epithelial cells (HBEC-3kt, 5–100 µg/mL) and human monocyte-derived macrophages (THP-1, 10–50 µg/mL). The results showed that all Cr was released as Cr(VI) for welding particles generated using standard FCWs whereas only minor levels (< 3% of total Cr) were released from the newly developed FCWs. Furthermore, the new FCWs were considerably less cytotoxic and did not cause any DNA damage in the doses tested. For the standard FCWs, the Cr(VI) released in cell media seemed to explain a large part of the cytotoxicity and DNA damage. In contrast, all particles caused rather similar inflammatory effects suggesting different underlying mechanisms. Taken together, this study suggests a potential benefit of substituting standard FCWs with Cr(VI)-reduced wires to achieve less toxic welding fumes and thus reduced risks for welders.

Protective role of epithelium in the guinea pig airway

1989 ◽  
Vol 66 (4) ◽  
pp. 1547-1552 ◽  
Author(s):  
M. Munakata ◽  
I. Huang ◽  
W. Mitzner ◽  
H. Menkes
Keyword(s):  
Guinea Pig ◽  
Protective Role ◽  
Airway Epithelial ◽  
Serosal Side ◽  
Epithelial Surface ◽  
Airway Responses ◽  
Airway Tone ◽  
Stimulation Of

We developed an in vitro system to assess the role of the epithelium in regulating airway tone using the intact guinea pig trachea (J. Appl. Physiol. 64: 466–471, 1988). This method allows us to study the response of the airway when its inner epithelial surface or its outer serosal surface is stimulated independently. Using this system we evaluated how the presence of intact epithelium can affect pharmacological responsiveness. We first examined responses of tracheae with intact epithelium to histamine, acetylcholine, and hypertonic KCl when stimulated from the epithelial or serosal side. We then examined the effect of epithelial denudation on the responses to these agonists. With an intact epithelium, stimulation of the inner epithelial side always caused significantly smaller changes in diameter than stimulation of the outer serosal side. After mechanical denudation of the epithelium, these differences were almost completely abolished. In the absence of intact epithelium, the trachea was 35-fold more sensitive to histamine and 115-fold more sensitive to acetylcholine when these agents were applied to the inner epithelial side. In addition, the presence of an intact epithelium almost completely inhibited any response to epithelial side challenge with hypertonic KCl. These results indicate that the airway epithelial layer has a potent protective role in airway responses to luminal side stimuli, leading us to speculate that changes in airway reactivity measured in various conditions including asthma may result in part from changes in epithelial function.

Losartan Increases No Production from the Bovine Aortic Wall That is Stimulated by Angiotensin II

2003 ◽  
Vol 1 (3) ◽  
pp. 113-117 ◽  
Author(s):  
M. Myronidou ◽  
B. Kokkas ◽  
A. Kouyoumtzis ◽  
N. Gregoriadis ◽  
A. Lourbopoulos ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Angiotensin Ii ◽  
Aortic Wall ◽  
Vascular Wall ◽  
Protective Role ◽  
Normal Function ◽  
No Production ◽  
Chemical Inactivation

In these studies we investigated if losartan, an AT1- receptor blocker has any beneficial effect on NO production from the bovine aortic preparations in vitro while under stimulation from angiotensin II. Experiments were performed on intact specimens of bovine thoracic aorta, incubated in Dulbeco's MOD medium in a metabolic shaker for 24 hours under 95 % O2 and 5 % CO2 at a temperature of 37°C. We found that angiotensin II 1nM−10 μM does not exert any statistically significant action on NO production. On the contrary, angiotensin II 10nM increases the production of NO by 58.14 % (from 12.16 + 2.9 μm/l to 19.23 + 4.2 μm/l in the presence of losartan 1nM (P<0.05). Nitric oxide levels depend on both rate production and rate catabolism or chemical inactivation. Such an equilibrium is vital for the normal function of many systems including the cardiovascular one. The above results demonstrate that the blockade of AT1-receptors favors the biosynthesis of NO and indicate the protective role of losartan on the vascular wall.

scholarly journals Protective Role of Flavonoids against Intestinal Pro-Inflammatory Effects of Silver Nanoparticles

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6610
Author(s):  
Ana T. Rufino ◽  
Ana Ramalho ◽  
Adelaide Sousa ◽  
José Miguel P. Ferreira de Oliveira ◽  
Paulo Freitas ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Protective Action ◽  
Cell Types ◽  
Protective Role ◽  
Toxic Effects ◽  
Oral Exposure ◽  
Dietary Flavonoids ◽  
Harmful Effects ◽  
Human Intestinal Cells

Silver nanoparticles (AgNP) have been increasingly incorporated into food-related and hygiene products for their unique antimicrobial and preservative properties. The consequent oral exposure may then result in unpredicted harmful effects in the gastrointestinal tract (GIT), which should be considered in the risk assessment and risk management of these materials. In the present study, the toxic effects of polyethyleneimine (PEI)-coated AgNP (4 and 19 nm) were evaluated in GIT-relevant cells (Caco-2 cell line as a model of human intestinal cells, and neutrophils as a model of the intestinal inflammatory response). This study also evaluated the putative protective action of dietary flavonoids against such harmful effects. The obtained results showed that AgNP of 4 and 19 nm effectively induced Caco-2 cell death by apoptosis with concomitant production of nitric oxide, irrespective of the size. It was also observed that AgNP induced human neutrophil oxidative burst. Interestingly, some flavonoids, namely quercetin and quercetagetin, prevented the deleterious effects of AgNP in both cell types. Overall, the data of the present study provide a first insight into the promising protective role of flavonoids against the potentially toxic effects of AgNP at the intestinal level.

scholarly journals Protocatechuic acids protects against high glucose- induced insulin resistance in human visceral adipose tissue

2016 ◽  
Vol 62 (5) ◽  
pp. 45-46
Author(s):  
Paulina Ormazabal ◽  
Beatrice Scazzocchio ◽  
Rosaria Varì ◽  
Annunziata Iacovelli ◽  
Roberta Masella
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Visceral Adipose Tissue ◽  
High Glucose ◽  
Protective Role ◽  
Insulin Sensitizer ◽  
20 Nm ◽  
Visceral Adipose

Adipocytes exposed to high glucose concentrations exhibit impaired insulin signaling. Binding of insulin to its membrane receptor activates insulin metabolic pathway leading to IRS-1 and AKT phosphorylations. The accumulation of visceral adipose tissue (VAT) correlates with insulin resistance and metabolic syndrome. Anthocyanins (ACN) are bioactive food compounds of great nutritional interest. We have shown that protocatechuic acid (PCA), a major metabolite of ACN, might exert insulin-sensitizer activities in human visceral adipose tissue. The aim of this work was to define the protective role of PCA against insulin-resistance induced by high glucose in VAT.Methodology: VAT obtained from control subject (BMI≤25) were separated in four experimental groups: i) PCA: samples treated for 24 h with 100 μM PCA, ii) GLU: VAT treated with 30 mM glucose for 24 h, iii) PCA+GLU: 1 hour incubation with 100 μM PCA before adding glucose (30 mM, 24 h), iv) CTR: vehicle. After treatment, VAT groups were (or not) acutely stimulated with insulin (20 nM, 20 min). Tyr-IRS-1 and Ser-Akt phosphorylations were assessed by Western blotting (WB) in basal or insulin stimulated tissues in all experimental groups. Samples were assessed for IRS-1, IR, Akt and GLUT4 protein content by WB. Results: No differences in protein contents between experimental groups were found. GLU tissues showed a lower increment in insulin-stimulated phosphorylation of IRS-1 and Akt compared to CTR and PCA samples. This impaired activation was completely reversed by the pretreatment with PCA.Conclusion: An in-vitro insulin-resistance condition induced by high glucose was established in biopsies of VAT. PCA restores the ability of GLU-tissues to fully respond to insulin by increasing IRS-1 and Akt phosphorylations. These results confirm the insulin-sensitizer effect of PCA on VAT previously reported by our group. An anthocyanin rich diet might help to protect against insulin-resistance in VAT.

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