The human placental proteome is affected by maternal smoking

Abstract

Detrimental effects of maternal smoking on the term placental proteome and steroid-metabolizing activities, and maternal hormone levels, were studied by using seven non-smoker and seven smoker placentae. Smoking significantly affected 18% of protein spots. The functional networks affected were i) cell morphology, cellular assembly and organization, cellular compromise (15 hits) and ii) DNA replication, recombination, and repair, energy production, nucleic acid metabolism (6 hits). Smoking significantly up-regulated such proteins as, SERPINA1, EFHD1 and KRT8; and down-regulated SERPINB2, FGA and HBB. Although maternal plasma steroids were not significantly altered, the catalytic activity of CYP1A1 was increased whereas CYP19A1 activity was reduced by smoking. Furthermore, transcript expression of CYP1A1 and CYP4B1 were induced while HSD17B2, NFKB and TGFB1 were repressed by smoking. The observed smoking induced wide-spread changes on placental proteome and transcript levels may contribute to the lowered birth weights of the new-born child and placenta.

Keywords: Foetus; Maternal smoking; Metabolism; Placenta; Proteomics; Steroid hormones.

Fig. 1

Proteomic analysis of the human placenta at term. (A) Representative 2-D SDS PAGE showing significantly altered protein spots following significant smoke-exposure (p < 0.05, ≥1.2-fold change). The spot numbers in red denote the spots shown in (C) and (D). Cleaved SERPINA1 (1-D Western blot of individual placental samples, n = 7/group), but not intact protein or transcript, was significantly increased in smoke-exposed placentae (B). 2-D Western blot (using the same protein pools as used for the proteomic analysis) (C) confirmed that SERPINA1 was present in multiple protein spots. VIM was significantly increased according to proteomic analysis but 2-D Western blot (D) demonstrated that the blue highlighted spots did not overlap with the primary antigen and total immuno-recognised VIM was decreased in smoke-exposed placentae, as shown by 1-D Western blot of individual placental samples (E). (F) Cluster analysis of the significantly altered 2-D protein spot volumes demonstrates separation of the non-smoker and smoke-exposed groups. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 2

1-D Western blot of individual placental samples (n = 7/group) showed a similar trend as found in the proteomic findings for (A) TAGLN2, (B) CA1 and (C) PRDX1, but this was not statistically significant.

Fig. 3

Network 1 (Cell Morphology, Cellular Assembly and Organization, Cellular Compromise) identified from maternal smoking effects on the proteome of the term human placenta. Networks were generated through the use of Ingenuity Pathway analysis. The intensity of color represents degree of up-regulation (purple) and down-regulation (red). A key to the identity of the node shapes is included in the figure. Dashed and solid lines represent indirect and direct interactions respectively. Lines without arrows indicate binding while closed arrows indicate action of first on second node and open arrows indicate translocation from first to second node. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 4

Network 2 (DNA Replication, Recombination, and Repair, Energy Production, Nucleic Acid Metabolism) identified from maternal smoking effects on the proteome of the term human placenta. Networks were generated through the use of Ingenuity Pathway analysis. The intensity of color represents degree of up-regulation (purple) and down-regulation (red). A key to the identity of the node shapes is included in the figure. Dashed and solid lines represent indirect and direct interactions respectively. Lines without arrows indicate binding while closed arrows indicate action of first on second node and open arrows indicate translocation from first to second node. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)