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Paraoxonase 2 protein is spatially expressed in the human placenta and selectively reduced in labour.

Alwarfaly S, Abdulsid A, Hanretty K, Lyall F - PLoS ONE (2014)

Bottom Line: No difference in protein expression of either isoform was found between the three sites in either the labour or non-labour group.At the middle site there was a highly significant decrease in PON2 expression in the labour group when compared to the non-labour group for both the 62 kDa form (p = 0.02) and the 43 kDa form (p = 0.006).No spatial differences were found within placentas at the mRNA level in either labour or non-labour.

View Article: PubMed Central - PubMed

Affiliation: Institute of Medical Genetics, University of Glasgow School of Medicine, Yorkhill Hospital, Glasgow, United Kingdom.

ABSTRACT
Humans parturition involves interaction of hormonal, neurological, mechanical stretch and inflammatory pathways and the placenta plays a crucial role. The paraoxonases (PONs 1-3) protect against oxidative damage and lipid peroxidation, modulation of endoplasmic reticulum stress and regulation of apoptosis. Nothing is known about the role of PON2 in the placenta and labour. Since PON2 plays a role in oxidative stress and inflammation, both features of labour, we hypothesised that placental PON2 expression would alter during labour. PON2 was examined in placentas obtained from women who delivered by cesarean section and were not in labour and compared to the equivalent zone of placentas obtained from women who delivered vaginally following an uncomplicated labour. Samples were obtained from 12 sites within each placenta: 4 equally spaced apart pieces were sampled from the inner, middle and outer placental regions. PON2 expression was investigated by Western blotting and real time PCR. Two PON2 forms, one at 62 kDa and one at 43 kDa were found in all samples. No difference in protein expression of either isoform was found between the three sites in either the labour or non-labour group. At the middle site there was a highly significant decrease in PON2 expression in the labour group when compared to the non-labour group for both the 62 kDa form (p = 0.02) and the 43 kDa form (p = 0.006). No spatial differences were found within placentas at the mRNA level in either labour or non-labour. There was, paradoxically, an increase in PON2 mRNA in the labour group at the middle site only. This is the first report to describe changes in PON2 in the placenta in labour. The physiological and pathological significance of these remains to be elucidated but since PON2 is anti-inflammatory further studies are warranted to understand its role.

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Related in: MedlinePlus

Western blots showing PON2 62(upper panel) and PON2 43 kDa isoform 2 (lower panel) expression in the outer site in non-labour and labour (n = 6 in each group).The graphs show the box and whiskers analysis of the blots. Comparison between zones was performed using Friedman analysis. Graph A, 62; Graph B, 43 kDa isoform 2. NLG non-labour group, LG labour group.
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pone-0096754-g007: Western blots showing PON2 62(upper panel) and PON2 43 kDa isoform 2 (lower panel) expression in the outer site in non-labour and labour (n = 6 in each group).The graphs show the box and whiskers analysis of the blots. Comparison between zones was performed using Friedman analysis. Graph A, 62; Graph B, 43 kDa isoform 2. NLG non-labour group, LG labour group.

Mentions: This experiment was designed to test if there was any difference in PON2 expression between labour and non-labour groups at the inner, middle or outer areas of placentas. Western blots showing placental PON2 expression in non-labour and labour at the inner site are shown in Figure 5 (upper panel 62 kDa isoform 1; lower panel 43 kDa isoform 2). The graphs and statistical analysis are shown below the blots. No differences were found. Western blots showing placental PON2 expression in non-labour and labour at the middle site are shown in Figure 6 (upper panel 62 kDa isoform 1; lower panel 43 kDa isoform 2). The graphs and statistical analysis are shown below the blots. There was a highly significant decrease in PON2 expression in the labour group when compared to the non-labour group for both the 62 kDa isoform 1, (p = 0.02) and the 43 kDa isoform 2, (p = 0.006). Western blots showing placental PON2 expression in non-labour and labour at the outer placental site are shown in Figure 7 (upper panel 62 kDa isoform 1; lower panel 43 kDa isoform 2). The graphs and statistical analysis are shown below the blots. No differences were found.


Paraoxonase 2 protein is spatially expressed in the human placenta and selectively reduced in labour.

Alwarfaly S, Abdulsid A, Hanretty K, Lyall F - PLoS ONE (2014)

Western blots showing PON2 62(upper panel) and PON2 43 kDa isoform 2 (lower panel) expression in the outer site in non-labour and labour (n = 6 in each group).The graphs show the box and whiskers analysis of the blots. Comparison between zones was performed using Friedman analysis. Graph A, 62; Graph B, 43 kDa isoform 2. NLG non-labour group, LG labour group.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4016019&req=5

pone-0096754-g007: Western blots showing PON2 62(upper panel) and PON2 43 kDa isoform 2 (lower panel) expression in the outer site in non-labour and labour (n = 6 in each group).The graphs show the box and whiskers analysis of the blots. Comparison between zones was performed using Friedman analysis. Graph A, 62; Graph B, 43 kDa isoform 2. NLG non-labour group, LG labour group.
Mentions: This experiment was designed to test if there was any difference in PON2 expression between labour and non-labour groups at the inner, middle or outer areas of placentas. Western blots showing placental PON2 expression in non-labour and labour at the inner site are shown in Figure 5 (upper panel 62 kDa isoform 1; lower panel 43 kDa isoform 2). The graphs and statistical analysis are shown below the blots. No differences were found. Western blots showing placental PON2 expression in non-labour and labour at the middle site are shown in Figure 6 (upper panel 62 kDa isoform 1; lower panel 43 kDa isoform 2). The graphs and statistical analysis are shown below the blots. There was a highly significant decrease in PON2 expression in the labour group when compared to the non-labour group for both the 62 kDa isoform 1, (p = 0.02) and the 43 kDa isoform 2, (p = 0.006). Western blots showing placental PON2 expression in non-labour and labour at the outer placental site are shown in Figure 7 (upper panel 62 kDa isoform 1; lower panel 43 kDa isoform 2). The graphs and statistical analysis are shown below the blots. No differences were found.

Bottom Line: No difference in protein expression of either isoform was found between the three sites in either the labour or non-labour group.At the middle site there was a highly significant decrease in PON2 expression in the labour group when compared to the non-labour group for both the 62 kDa form (p = 0.02) and the 43 kDa form (p = 0.006).No spatial differences were found within placentas at the mRNA level in either labour or non-labour.

View Article: PubMed Central - PubMed

Affiliation: Institute of Medical Genetics, University of Glasgow School of Medicine, Yorkhill Hospital, Glasgow, United Kingdom.

ABSTRACT
Humans parturition involves interaction of hormonal, neurological, mechanical stretch and inflammatory pathways and the placenta plays a crucial role. The paraoxonases (PONs 1-3) protect against oxidative damage and lipid peroxidation, modulation of endoplasmic reticulum stress and regulation of apoptosis. Nothing is known about the role of PON2 in the placenta and labour. Since PON2 plays a role in oxidative stress and inflammation, both features of labour, we hypothesised that placental PON2 expression would alter during labour. PON2 was examined in placentas obtained from women who delivered by cesarean section and were not in labour and compared to the equivalent zone of placentas obtained from women who delivered vaginally following an uncomplicated labour. Samples were obtained from 12 sites within each placenta: 4 equally spaced apart pieces were sampled from the inner, middle and outer placental regions. PON2 expression was investigated by Western blotting and real time PCR. Two PON2 forms, one at 62 kDa and one at 43 kDa were found in all samples. No difference in protein expression of either isoform was found between the three sites in either the labour or non-labour group. At the middle site there was a highly significant decrease in PON2 expression in the labour group when compared to the non-labour group for both the 62 kDa form (p = 0.02) and the 43 kDa form (p = 0.006). No spatial differences were found within placentas at the mRNA level in either labour or non-labour. There was, paradoxically, an increase in PON2 mRNA in the labour group at the middle site only. This is the first report to describe changes in PON2 in the placenta in labour. The physiological and pathological significance of these remains to be elucidated but since PON2 is anti-inflammatory further studies are warranted to understand its role.

Show MeSH
Related in: MedlinePlus