Immunohistochemical analysis of paraoxonases-1, 2, and 3 expression in normal mouse tissues.
ABSTRACT The paraoxonase (PON) enzyme family, comprising PON1, PON2, and PON3, are antioxidant enzymes that degrade oxidised phospholipids. We describe the immunohistochemical localisation of the PON proteins in the normal mouse. Antibodies were obtained by inoculating rabbits with peptides derived from specific sequences of mature PONs. PON1 and PON3 were detected in the skin external epithelium, acini of the sebaceous glands, tongue epithelium, acini of the submandibular gland, surface epithelia of the stomach and the intestine, hepatocytes, exocrine pancreas acini, fibre tracts of the encephalon and the spinal cord, skeletal and cardiac muscle, eye lens epithelium and retinal layers, adipocytes, chondrocytes, epithelial cells of the trachea and bronchiole, ovary follicular fluid, seminiferous tubules, spermatozoa, and kidney proximal tubules. PON2 expression was weaker than that of PON1 and PON3, and was absent in some of the tissues studied, such as submandibular gland, nerve cells, and adipocytes. In muscle cells, PON2 expression was restricted to the endomysium. Apolipoprotein A-I did not colocalise with PONs, suggesting local synthesis. This study provides an experimental model to investigate the role played by these enzymes as antioxidants and their relationship with the development of a variety of diseases.
SourceAvailable from: Jadwiga Oczos[Show abstract] [Hide abstract]
ABSTRACT: Purpose: Biochemical and genetic analyses established a contribution of lipid metabolism to AMD pathology. PON1 (Paraoxonase 1) encodes an anti-oxidative protein involved in high density lipoprotein (HDL) function and was found to be associated with AMD. Here we used Pon1-/- mice to study the influence of PON1 on retinal physiology and to reveal the potential impact of PON1 on AMD aetiology. Methods: Laser capture microdissection served to isolate single retinal layers. Retinal function was assessed by ERG. Retinal and RPE morphology were monitored by fundus imaging, fluorescein angiography, light and transmission electron microscopy, and immunofluorescence microscopy. Levels of mRNA and composition of phospholipid species were determined by real-time PCR and LC-MS, respectively. Results: Adult (8 weeks old) Pon1-/- mice displayed normal retinal function and morphology, but their retinas contained reduced amounts of lysophosphatidylcholines (LPCs) compared to controls. Aged (12 months old) Pon1-/- animals did not show any morphological or molecular signs of photoreceptor or RPE degeneration, or of accelerated aging. Photoreceptors of Pon1-/- and control mice were similarly susceptible to light damage. Conclusions: PON1 is not essential for normal development, function, ageing and the defense against light damage of the mouse retina. Reduced levels of LPCs in eyes of Pon1-/- mice may reflect a decreased activity of phospholipase A2 or altered anti-oxidative activity in aged eyes.Investigative Ophthalmology & Visual Science 07/2014; 55(8). DOI:10.1167/iovs.14-14332 · 3.66 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: This study revealed and characterised the presence of the antioxidant enzymes paraoxonase (PON) type 1 (PON-1, extracellular) and type 2 (PON-2, intracellular) in boar semen. To evaluate PON-1, an entire ejaculate from each of ten boars was collected and the seminal plasma was harvested after double centrifugation (1,500g for 10 min). Seminal plasma was analysed for concentration as well as enzymatic activity of PON-1 and total cholesterol levels. Seminal-plasma PON-1 concentration ranged from 0.961 to 1.670 ng/ml while its enzymatic activity ranged from 0.056 to 0.400 IU/ml, which represent individual variance. Seminal-plasma PON-1 concentration and enzymatic activity were negatively correlated (r = −0.763; P < 0.01). The activity of seminal-plasma PON-1 negatively correlated with ejaculate volume (r = −0.726, P < 0.05), but positively correlated with sperm concentration (r = 0.654, P < 0.05). Total seminal-plasma cholesterol concentration positively correlated with PON-1 activity (r = 0.773; P < 0.01), but negatively correlated with PON-1 concentration (r = −0.709; P < 0.05). The presence of intracellular PON-2 was determined via immunocytochemistry in spermatozoa derived from artificial insemination. PON-2 localised to the post-acrosomal area of the sperm head and principal piece of the tail in membrane-intact spermatozoa. In summary, PON is present in boar semen, with PON-1 at low levels in seminal plasma and PON-2 within the spermatozoa. Further studies are needed to characterise the relationship between antioxidant PONs with sperm and other seminal-plasma parameters. Mol. Reprod. Dev. 2014. © 2014 Wiley Periodicals, Inc.Molecular Reproduction and Development 12/2014; 82(1). DOI:10.1002/mrd.22444 · 2.68 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: Paraoxonase1 (PON1) is a glycoprotein associated with high density lipoprotein and has antioxidant activity. The impact of PON1 in various stages of spermatogenesis has also been suggested. This study was aimed to investigate frequencies of phenotypes and Q192R genotypes of PON1 in fertile and infertile males. Q192R variants of PON1 were determined in 150 fertile and 150 infertile men using the polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) technique. Plasma arylesterase and paraoxonase activities were detected by spectrophotometry and malondialdehyde (MDA) level was measured using thiobarbituric acid. Our results showed no significant difference in the distribution of PON1 genotypes and alleles between fertile and infertile groups. However morphology and motility of sperm were associated with various genotypes of PON1. The number of fertile males with the BB phenotype (high activity) was significantly higher than that of infertile males, whereas the number of individuals with the AB phenotype (moderate activity) was statistically higher in infertile men compared with the fertile group. Additionally, MDA and arylesterase activity levels were significantly higher in infertile subjects compared with fertile men. We speculate that the low activity of PON1 can be a risk factor for male infertility probably due to a decrease in antioxidant activity of PON1 and increase in lipid peroxidation.Systems Biology in Reproductive Medicine 09/2014; 60(6). DOI:10.3109/19396368.2014.960624 · 1.70 Impact Factor