Altered inflammation, paraoxonase-1 activity and HDL physicochemical properties in obese humans with and without Prader-Willi syndrome
Dipartimento di Scienze Cliniche Specialistiche e Odontostomatologiche-Università Politecnica delle Marche, 60100 Ancona, Italia. Disease Models and Mechanisms
(Impact Factor: 4.97).
07/2012; 5(5):698-705. DOI: 10.1242/dmm.009209
Prader-Willi syndrome (PWS) represents the most common form of genetic obesity. Several studies confirm that obesity is associated with inflammation, oxidative stress and impairment of antioxidant systems; however, no data are available concerning PWS subjects. We compared levels of plasma lipids and C-reactive protein (CRP) in 30 subjects of 'normal' weight (18.5-25 kg/m(2)), 15 PWS obese (>30 kg/m(2)) subjects and 13 body mass index (BMI)-matched obese subjects not affected by PWS. In all subjects, we evaluated the levels of lipid hydroperoxides and the activity of paraoxonase-1 (PON1), an enzyme involved in the antioxidant and anti-inflammatory properties exerted by high-density lipoproteins (HDLs). Furthermore, using the fluorescent molecule of Laurdan, we investigated the physicochemical properties of HDLs isolated from normal weight and obese individuals. Altogether, our results demonstrated, for the first time, higher levels of lipid hydroperoxides and a lower PON1 activity in plasma of obese individuals with PWS with respect to normal-weight controls. These alterations are related to CRP levels, with a lower PON1:CRP ratio in PWS compared with non-PWS obese subjects. The study of Laurdan fluorescence parameters showed significant modifications of physicochemical properties in HDLs from PWS individuals. Whatever the cause of obesity, the increase of adiposity is associated with inflammation, oxidative stress and alterations in HDL compositional and functional properties.
Available from: Jorge Joven
- "However, reports measuring PON1 paraoxonase activity are not so consistent. A decrease in paraoxonase activity was described by some authors   , while others did not observe any significant changes [7,51–53]. "
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ABSTRACT: To investigate the relationships between serum paraoxonase-1 (PON1), insulin resistance, and metabolic syndrome (MetS) in childhood obesity.
We studied 110 obese children and 36 non-obese children with a similar gender and age distribution. We measured serum PON1 activity against 5-thiobutyl butyrolactone (TBBLase) and against paraoxon (paraoxonase). PON1 concentration was measured separately as were the levels of several standard metabolic variables. The homeostasis model assessment (HOMA) index was calculated as an estimate of insulin resistance.
TBBLase was significantly decreased in obese children (P=0.008), while paraoxonase activity and PON1 concentrations showed non-significant trends towards decrease and increase, respectively (P=0.054 and P=0.060). TBBLase and paraoxonase specific activities were significantly decreased (P=0.004 and P=0.018, respectively). TBBLase specific activity was inversely associated with BMI, percentage body fat, insulin, HOMA, triglycerides, and C-reactive protein, and directly associated with HDL-cholesterol. Paraoxonase specific activity showed similar associations with BMI, percentage fat, HDL-cholesterol, and C-reactive protein. Obese children with MetS had lower TBBLase activities than obese children without MetS (P=0.018). Linear regression analyses showed that TBBLase was independently associated with HDL-cholesterol, BMI, percentage body fat and PON155 polymorphism, but paraoxonase activity was associated only with PON1192 polymorphism.
Our results suggest that PON1 may play a role in the onset and development of metabolic alterations in childhood obesity leading to diabetes and cardiovascular disease later in life. However, being derived from statistical association study, this finding cannot be seen as showing cause-effect.
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ABSTRACT: Background Psoriasis is a chronic, inflammatory skin condition associated with a high frequency of cardiovascular events. Modifications of plasma lipids, and an increase in the levels of biochemical markers of inflammation and lipid peroxidation have been reported in subjects with psoriasis, suggesting a relationship between psoriasis, inflammation and oxidative damage.
Objectives To investigate whether modulation of inflammatory activity by tumour necrosis factor-α inhibitors in patients with psoriasis is associated with modification of lipid profiles, oxidative stress and paraoxonase (PON)1 activity.
Methods The levels of plasma lipids and lipoprotein(a), and the levels of the markers of inflammation and lipid peroxidation were evaluated in subjects with psoriasis (n = 23) before and after 24 weeks of treatment with etanercept. In the same subjects plasma total antioxidant capacity and the activity of PON1, an antioxidant and anti-inflammatory enzyme associated with the high-density lipoproteins (HDLs), were investigated.
Results The results showed that clinical improvement in patients with psoriasis treated with etanercept is associated with a reduction in the levels of inflammatory markers [C-reactive protein (CRP)] and lipid peroxidation, and also with increased antioxidant capacity in the serum of patients with psoriasis. These modifications are associated with a significant increase in the activity of PON1. A significant increase in the PON1/CRP ratio has also been observed in patients with psoriasis after treatment. The significant inverse correlation between CRP and PON1 activity suggests a relationship between PON1 activity and inflammation.
Conclusions Treatment with etanercept is associated with a reduction in lipid peroxidation and an improvement in HDL antioxidant and anti-inflammatory properties.
Available from: Arianna Vignini
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ABSTRACT: Abstract Objective Obesity and / or psychopathological disorders of parents represent risk factors for childhood obesity. The aim of the study was to investigate the link between obesity in pregnancy and oxidative stress. Methods. Venous blood was collected from 37 women at the eighth month of gestation (19 obese e 28 normal weight). Cord blood was obtained at birth from newborns of obese mothers and controls. Cord blood and maternal blood was used to separate plasma to be used for the evaluation of leptin, oxidized LDL and paraoxonase (PON1) activity. Results Higher levels of leptin were observed both in maternal blood and cord blood of children of obese women compared to normal weight women. The data showed also lower levels of PON1 activity in plasma of obese women and in the cord blood of their children. Furthermore, a positive correlation was established between levels of PON1 activity in maternal blood and cord blood, suggesting a relationship between PON1 in maternal plasma and fetal cord blood. Conclusions
Essential obesity in pregnancy is associated with hyperleptinemia. PON1 exerts an antioxidant role therefore our results demonstrated that obesity exposes to an increased susceptibility to oxidative damage in both mothers and newborns.
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