Heat shock protein 27 is spatially distributed in the human placenta and decreased during labor
Authors: Alexander Fletcher
Akrem Abdulsid
Fiona Lyall
Journal: PLoS ONE (2013)
Discipline: Multidisciplinary
Keywords: Placental oxidative stress; Heat shock proteins (HSPs); HSP 27; Labor; Placenta regions
Affiliations: University of Glasgow School of Medicine, Institute of Medical Genetics, Yorkhill Hospital, Glasgow, United Kingdom.

Abstract:  Placental oxidative stress is a feature of human labor. Heat shock proteins (HSPs) play a key role in cellular stress. We hypothesized that placental expression of the small HSP 27 would be altered during labor and expression would vary in different regions of the placenta. Six women in labor who delivered vaginally and 6 women not in labor, who were delivered by Cesarean section, were recruited. Four equally spaced pieces were sampled from the inner, middle and outer regions of each placenta (total 12 samples per placenta). HSP 27 expression was investigated by Western blot analysis and RT-PCR. For non-labor, there was less HSP 27 protein in the inner placenta region compared with both the middle region (p&lt;0.05) and outer region (p&lt;0.05). For labor, there was also less HSP 27 protein in the inner region compared with both the middle (p&lt;0.02) and outer region (p&lt;0.01). When the 3 regions of the placenta were compared for non-labor versus labor there was less HSP 27 in the labor group at both the inner (p&lt;0.05) and middle regions (p&lt;0.005) compared to non-labor. Similar to HSP 27 protein, there was less HSP 27 mRNA in the labor group in both the inner region (p&lt;0.05) and middle region (p&lt;0.02) compared to non-labor. This study suggests that placental HSP 27 may play a role in labor and is spatially controlled. The results have important implications for how data obtained from studies in the placenta can be influenced by sampling methods. 

Retracted: Yes

PubPeer comments:
 2018 retraction notice. http: journals.plos.org plosone article?id=10.1371 journal.pone.0199803 The PLOS ONE Editors retract this article [1] in light of concerns raised about Figure 2. Similarities were noted between bands within the u03b2-actin panel, which also appears to duplicate the u03b2-actin panel in Figure 2 of [2]. Additionally, the HSP 27 blots appear to have been altered during figure preparation, based on background discontinuities above and below lanes 3,4 in the upper (non-labor) panel and above lanes 5u20137 of the middle (labor) panel. The University of Glasgow investigated these concerns and recommended retraction owing to signs of data manipulation and falsification. In the course of the investigation, it was established that the original data underlying the figure panels in question are no longer available. In light of these concerns, and in line with the institutionu2019s communication, the PLOS ONE Editors retract this article, as the concerns raised call into question the integrity of the data and validity of the articleu2019s results and conclusions. AA agreed with the retraction. AF and FL did not respond. References 1. Abdulsid A, Fletcher A, Lyall F (2013) Heat Shock Protein 27 Is Spatially Distributed in the Human Placenta and Decreased during Labor. PLoS ONE 8(8): e71127. https: doi.org 10.1371 journal.pone.0071127 pmid:23990930 View Article PubMed NCBI Google Scholar 2. Abdulsid A, Hanretty K, Lyall F (2013) Heat Shock Protein 70 Expression Is Spatially Distributed in Human Placenta and Selectively Upregulated during Labor and Preeclampsia. PLoS ONE 8(1): e54540. https: doi.org 10.1371 journal.pone.0054540 pmid:23382911 , 
 An illustration of the problems in Figure 2. * Green arrows point to the background discontinuities in the HSP 27 blots * Red and blue arrows point to similarities between certain bands within the b-actin panel ![file] ,