Paraoxonase 1 status is a major Janus-faced component of mild and moderate acute ischemic stroke and consequent disabilities.

AIMS: This study aims to examine the associations between paraoxonase 1 (PON)1 status and acute ischemic stroke (AIS) and consequent disabilities. METHODS: This study recruited 122 patients with AIS and 40 healthy controls and assessed the Q192R gene variants, arylesterase (AREase) and chloromethyl phenylacetate (CMPAase) activities, and high-density lipoprotein cholesterol (HDLc) in baseline conditions. AREase and CMPAase were measured 3 months later. The National Institutes of Health Stroke Scale (NIHSS) and the modified Rankin score (mRS) were assessed at baseline and 3 and 6 months later. RESULTS: Reduced CMPAase and increased AREase activities are significantly associated with AIS and mRS and NIHSS scores (baseline and 3 and 6 months later). The best predictor of AIS/disabilities was a decrease in the z-unit-based composite zCMPAase-zAREase score. Serum high density lipoprotein cholsterol (HDLc) was significantly correlated with CMPAase, but not AREase, activity and a lowered zCMPAase + zHDLc score was the second best predictor of AIS/disabilities. Regression analysis showed that 34.7% of the variance in baseline NIHSS was explained by zCMPAase-zAREase and zCMPAase + zHDLc composites, HDLc, and hypertension. Neural network analysis showed that stroke was differentiated from controls with an area under the ROC curve of 0.975 using both new composite scores, PON1 status, hypertension, dyslipidemia, previous stroke as body mass index. The PON1 Q192R genotype has many significant direct and mediated effects on AIS/disabilities, however, its overall effect was not significant. DISCUSSION: PON1 status and the CMPAase-HDLc complex play key roles in AIS and its disabilities at baseline and 3 and 6 months later.

In Mild and Moderate Acute Ischemic Stroke, Increased Lipid Peroxidation and Lowered Antioxidant Defenses Are Strongly Associated with Disabilities and Final Stroke Core Volume.

In acute ischemic stroke (AIS), there are no data on whether oxidative stress biomarkers have effects above and beyond known risk factors and measurements of stroke volume. This study was conducted in 122 mild-moderate AIS patients and 40 controls and assessed the modified ranking scale (mRS) at baseline, and 3 and 6 months later. We measured lipid hydroperoxides (LOOH), malondialdehyde (MDA), advanced oxidation protein products, paraoxonase 1 (PON1) activities and PON1 Q192R genotypes, high density lipoprotein cholesterol (HDL), sulfhydryl (-SH) groups), and diffusion-weighted imaging (DWI) stroke volume and fluid-attenuated inversion recovery (FLAIR) signal intensity. We found that (a) AIS is characterized by lower chloromethyl acetate CMPAase PON1 activity, HDL and -SH groups and increased LOOH and neurotoxicity (a composite of LOOH, inflammatory markers and glycated hemoglobin); (b) oxidative and antioxidant biomarkers strongly and independently predict mRS scores 3 and 6 months later, DWI stroke volume and FLAIR signal intensity; and (c) the PON1 Q192R variant has multiple effects on stroke outcomes that are mediated by its effects on antioxidant defenses and lipid peroxidation. Lipid peroxidation and lowered -SH and PON1-HDL activity are drug targets to prevent AIS and consequent neurodegenerative processes and increased oxidative reperfusion mediators due to ischemia-reperfusion injury.

Effect of Dialyzer Reuse on the Activity of Paraoxonase 1 in Patients on Hemodialysis.

Background: Cardiovascular disease is the major cause of mortality in patients undergoing chronic hemodialysis treatment. The oxidative modification of low-density lipoprotein is a crucial step in the pathogenesis of atherosclerosis. Paraoxonase 1 (PON1) is the protein responsible for most of the antioxidant activity of high-density lipoprotein, and its reduced levels are associated with more cardiovascular events in several populations. In hemodialysis patients, reduced PON1 activity has been shown to be associated with increased cardiovascular mortality. Studies have shown that after the hemodialysis session, the activity of PON1 increases. The influence of dialyzer reuse on the activity of PON1 is unknown. We aimed to evaluate the effect of the reuse of two types of dialyzers (polynephron and polyethersulfone) on the PON1 activity of hemodialysis patients. Subjects and Methods: A total of 30 patients on hemodialysis were included. Pre- and post-dialysis blood samples were collected to analyze the activity of PON1 in thefirst use of the dialyzer and in the hemodialysis session of its sixth reuse. This process was carried out with polynephron (bisphenol-free) and polyethersulfone dialyzers. Results: We found that post-dialysis PON1 activity was significantly higher than pre-dialysis activity in both thefirst use and sixth reuse (P < 0.001). Conclusion: The practice of reusing the dialyzer did not interfere with the improvement of PON1 activity after the hemodialysis session.

Deficit schizophrenia and its features are associated with PON1 Q192R genotypes and lowered paraoxonase 1 (PON1) enzymatic activity: effects on bacterial translocation.

BACKGROUND: Primary deficit schizophrenia (DS) is characterized by enduring negative symptoms and represents a qualitatively different disease entity with respect to non-deficit schizophrenia (NDS). No studies investigated the association between the enzyme paraoxonase 1 (PON1) and DS and its phenomenology. METHODS: In this case-control study, Thai women and men, aged 18 to 65 years, were divided in DS (n = 40) and NDS (n = 40) and were compared to controls (n = 40). PON1 activities against 4-(chloromethyl)phenyl acetate (CMPA) and phenylacetate were determined. Moreover, subjects were genotyped for their PON1 Q192R polymorphism and immunoglobulin A (IgA) levels responses directed to Gram-negative bacteria were measured. RESULTS: DS is significantly associated with the QQ genotype and the Q allele as compared with NDS and controls. PON1 activities are significantly and inversely associated with negative symptoms, formal thought disorders, psychomotor retardation, excitation and DS. The presence of the Q allele is associated with increased IgA responses to Pseudomonas aeruginosa, Morganella morganii, and Pseudomonas putida as compared with RR carriers. CONCLUSIONS: The PON1 Q allele and lower PON1 activities especially against CMPA are associated with DS, indicating lowered quorum quenching abilities as well as lowered defenses against lipoperoxidation and immune activation. It is suggested that lowered PON1 activity in DS constitutes an impairment in the innate immune system which together with lowered natural IgM may cause lower immune regulation thereby predisposing toward greater neurotoxic effects of immune-inflammatory, oxidative and nitrosative pathways and Gram-negative microbiota.

Natural regulatory IgM-mediated autoimmune responses directed against malondialdehyde regulate oxidative and nitrosative pathways and coupled with IgM responses to nitroso adducts attenuate depressive and physiosomatic symptoms at the end of term pregnancy.

AIM: We aimed to delineate the effects of immunoglobulin (Ig)M-mediated autoimmune responses directed against malondialdehyde (MDA) and nitroso (SNO) adducts on nitro-oxidative stress and depressive and physiosomatic symptoms (DPSS) at the end of term. METHODS: IgM responses to MDA, NO (nitroso) adducts formed by nitrosylation, and NO2 tyrosine formed by nitration were measured as well as hydroperoxides (ferrous oxidation xylenol orange), advanced protein oxidation products (AOPP), and NO metabolite (NOx) levels in women at the end of term pregnancy and in normal controls. RESULTS: IgM responses to MDA were significantly and inversely associated with AOPP, ferrous oxidation xylenol orange, and NOx and DPSS. IgM responses to NO adducts were significantly and inversely associated with DPSS and positively with NOx levels. There were significant associations between IgM responses to MDA, NO adducts, and NO2 tyrosine. The DPSS score was predicted by AOPP and a lifetime history of premenstrual syndrome (both positively) and IgM responses to NO adducts (inversely). Furthermore, 71.8% of the variance in the index of nitro-oxidative stress was explained by lowered IgM responses to MDA, antioxidant levels (zinc, total radical trapping parameter), and inflammatory mediators. CONCLUSION: Lowered levels of IgM responses to MDA during pregnancy are accompanied by a reduced regulation of nitro-oxidative processes thereby explaining increased oxidative and nitrosative stress biomarkers in association with DPSS. IgM responses to NO adducts, which reflect nitrosylation as a consequence of increased NO production, regulate DPSS symptoms at the end of term and are a trait marker of major depression. IgM responses to MDA are a key part of the compensatory anti-inflammatory responses system.

Does fish oil or folic acid prevent vascular changes in female progeny caused by maternal exposure to fluoxetine?

AIMS: Fluoxetine (FLX) is an antidepressant worldwide prescribed throughout life stages, including pregnancy and breastfeeding. Out of pregnancy, the combination of FLX with fish oil (FO) and folic acid (FA) is carried to enhance the therapeutic activity and reduce the side effects of the antidepressant. During pregnancy, FO and FA have been used to promote fetal development, and reduce, in mother, the risk of gestational and post-pregnancy depression. To evaluate if maternal exposure during pregnancy and lactation to FLX associated with FO or FA would prevent the antidepressant side effects in aorta reactivity and nitric oxide metabolites (NOx) plasmatic levels. We also sought to understand, in female offspring, the vascular effects of intrauterine and lactation exposure to FO and FA monotherapy. MAIN METHODS: Wistar rats were treated with water (control group), FLX (5mg/kg/day), FO (1.3g/kg/day), FA (3mg/kg/day), FLX+FO and FLX+FA, throughout pregnancy and lactation. On adulthood, in female offspring were evaluated the vascular reactivity to phenylephrine (Phe), the NOx and homocysteine (HCY) plasmatic levels. KEY FINDINGS: The developmental exposure to the associations of FO or FA with FLX did not correct the aortic hyporreactivity and increased NOx levels induced by intrauterine and lactation exposure to FLX. Also, isolated exposure to FO and FA did not interfere with Phe-induced aortic contraction and neither interferes with NOx and HCY plasmatic levels. SIGNIFICANCE: The developmental exposure to FO and FA was safe for vascular function of female offspring but did not prevent the vascular effects of FLX-exposure.