Use of cDNA arrays to generate differential expression profiles for inflammatory genes in human gestational membranes delivered at term and preterm

Inflammatory processes are implicated in preterm labour (PTL). To identify potential novel markers for PTL, we have used commercial cDNA arrays to generate profiles of differential expression of inflammation-associated genes in gestational membranes with term and PTL. RNA for cDNA probe synthesis was isolated from reflected human amnion and choriodecidua membranes delivered following Caesarean section at term before the onset of labour (TNL, n = 4), spontaneous labour at term (TSL, n = 4), and PTL with and without chorioamnionitis (PTL+INF and PTL-INF respectively, n = 4 each). Profiles were displayed relative to TNL and statistical comparisons of TSL versus TNL and PTL+INF versus PTL-INF were performed. Elevated expression of chemokines macrophage inflammatory protein 1beta(MIP-1beta) and pulmonary and activation-regulated chemokine (PARC) was observed in PTL+INF compared to PTL-INF amnion and choriodecidua respectively (P = 0.03). Likewise, the cytokines oncostatin-M and pre-B cell enhancing factor (PBEF) were more highly expressed in PTL+INF compared with PTL-INF and in TSL compared with TNL respectively (P = 0.03). Conversely, inhibin A, tissue inhibitors of matrix metalloproteinase (TIMP)-3 and TIMP-4 were all significantly elevated in PTL-INF compared with PTL+INF (P = 0.03). Furthermore, differential expression patterns of classes of genes, grouped according to function (e.g. chemokines), were noted. The cDNA array approach holds promise for identification of new candidate markers or combinations thereof for prediction or diagnosis of PTL, as well as for increasing our understanding of the particular aetiologies involved.