Pro-labour myometrial gene expression: are preterm labour and term labour the same?

Area of Science:

• Reproductive biology
• Molecular genetics
• Obstetrics

Background:

• Preterm labour (PTL) is a major cause of neonatal complications.
• The precise mechanisms driving PTL remain largely unknown.
• Understanding labour mechanisms is crucial for managing PTL.

Purpose of the Study:

• To determine if term labour (TL) accurately models preterm labour (PTL).
• To compare pro-labour gene and protein expression in preterm and term labouring myometrium.
• To investigate regional differences (upper vs. lower uterine segments) in labour-induced gene expression.

Main Methods:

• Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) for mRNA expression.
• Western blot analysis for protein synthesis.
• Myometrial tissue samples from upper and lower uterine segments before and after labour (preterm and term).

Main Results:

• Significant differences in prostaglandin H synthase type-2 (PGHS-2), IL-1beta, IL-6, and IL-8 mRNA expression between TL and PTL in the lower uterine segment.
• Increased IL-1beta and IL-8 mRNA in both PTL and TL compared to controls; PGHS-2 and IL-6 increased only in TL.
• No significant changes in oxytocin receptor or connexin-43 mRNA/protein levels due to PTL or TL.

Conclusions:

• Term labour (TL) and preterm labour (PTL) involve distinct molecular changes in the myometrium.
• The lower uterine segment exhibits more pronounced labour-induced gene expression changes.
• Inflammatory cytokines, such as IL-1beta and TNF-alpha, are key regulators of labour-associated genes like PGHS-2 and IL-8.