Transferrin Sialylation in Smoking and Non-Smoking Pregnant Women with Intrauterine Growth Restriction

Abstract

Transferrin (Tf) is a glycosylated protein responsible for transporting iron. Various sialylation levels of Tf are observed during physiological and pathological processes. We studied if the changes in iron stores as well as tobacco smoke may have an impact on foetal development and in consequence lead to intrauterine growth restriction (IUGR). In the third trimester of pregnancy, lower levels of 4-sialoTf isoform and higher levels of 5-sialoTf were observed in the serum of non-smoking women with IUGR in comparison to the control group. On the day of labour, level of 2-sialoTf was significantly lower and level of 3-sialo was Tf higher in the serum of non-smoking women. Level of 4-sialo was found lower in the serum of smoking women with IUGR than in the control group. The observed changes may suggest a connection between iron stores, transport of iron to the foetus and foetal development.

The Influence of Tobacco Smoke on Protein and Metal Levels in the Serum of Women during Pregnancy

“…To determine long-term tobacco smoke exposure, Cd levels are a more suitable indicator [29]. Cd concentration in the blood of smoking women was 3.7-times higher than in the blood of non-smoking women, which is consistent with other research and points to tobacco smoke as a significant source of this heavy metal [3, 7, 30]. Cd concentrations in the blood correlated negatively with Zn levels (r = −0.823, p = 0.023) even if no differences between smoking and non-smoking women in the concentration of Zn were observed.…”

“…Tobacco smoke influences the level of protein production, degradation and modification (e.g. sialylation) [7, 26]. Exposure to tobacco smoke additionally influences the inflammation what may be seen by raised levels of C-reactive protein and white blood cells [27].…”

“…However, α1-acid glycoprotein concentration in our study was not correlated with Cd. In addition, as tobacco smoke changes the sialylation of other proteins (like transferrin) [7], it is possible that the negative influence of smoking should be looked for in differences in glycosylation, not only in the concentration of proteins.…”

“…Prior studies have shown that alterations observed in each protein fraction are a useful indicator of the progress of diseases. In addition, changes in protein metabolism and differences in the protein structure are connected with pregnancy disorders like preeclampsia, IUGR and LBW [7]. …”