Comparative Study on the Expression of Cytokine--receptor Genes in Normal and Preeclamptic Human Placentas Using DNA Microarrays

Aims: To study the relationship between the expression levels of cytokine/receptor genes in placenta and the pathogenesis of pre-eclampsia.

Methods: The study was performed to compare the mRNA contents of cytokine (receptor) superfamily genes in placentas from 5 patients with pre-eclampsia and 5 strictly matched normal pregnancies. A complementary DNA microarray representing over 220 cytokine-associated genes was employed to complete the detection.

Results: It was shown that, among the 221 kinds of cytokine-associated genes, 162 of those including 22 interleukin/interleukin receptor genes presented with a difference of over two times in pre-eclamptic placentas compared to normal placentas. Most of the 22 interleukin/interleukin receptor genes were shown to be highly expressed in preeclamptic placenta, while the expression of IL-2 receptor (IL-2 R alpha, GenBank: X01057) gene in preeclamptic placenta was comparatively lower than that in normal placenta. Furthermore, some tumor necrosis factor (TNF)/receptor superfamily genes, including TNF (GenBank: X02910), TNF ligands (GenBank: U03398, U37518, AF053712, AF055872) and TNF receptors (GenBank: X60592, X63717, M83554, AF016266, AF016267, U81232) were also shown to be highly expressed in pre-eclamptic placenta. Besides interleukin and tumor necrosis factor (receptor) gene superfamily, the mRNA levels of another 39 cytokine and 15 cytokine receptor genes showed a two-fold difference between pre-eclamptic and normal placental tissues. Additionally, most of the genes were up-regulated in pre-eclamptic placenta.

Conclusions: The up-regulation of cytokine-associated genes including interleukin and TNF (receptor) superfamily expression in placenta might be intensively related to the pathogenesis of pre-eclampsia.