Expression profile of proinflammatory mediators in the placenta of mares during physiological detachment and retention of fetal membranes.

This study investigate the expression levels of specific chemokines and IL-17 in the placentas of mares that have retained their fetal membranes (RFM) during parturition, versus those that have expelled them normally. Their findings suggest that differences in chemokine expression and the types of immune cells recruited may contribute to RFM occurrence.

Background and Aim

• The researchers aim to better understand the inflammatory processes that occur during physiological parturition (the process of giving birth) in mares.
• They focus on a condition known as Retention of Fetal Membranes (RFM), where the placenta fails to be expelled post-parturition. This condition is poorly understood in horses.
• The team hypothesizes that differences in the expression of certain proinflammatory mediators may contribute to RFM.

Methodology

• Expression levels of selected chemokines (proteins that guide the movement of cells) and interleukin 17 (IL-17, a type of immune signalling molecule) were evaluated in the parts of the equine placenta (allantochorion and the endometrium).
• Comparison was made between mares that had RFM and those that expelled their membranes normally.

Findings

• Differences in mRNA expression in the placenta were observed among the mare groups for genes encoding for several chemokines and IL-17.
• No differences were observed in the expression of CCL5 and CXCL6 genes.
• Analysis suggested links among the expression patterns of several chemokines (CXCL6, CXCL8, CXCL1, CCL5, CCL4, CX3CL1 and CXCL10).
• Possible inhibition of the chemokine CXCL10 by IL-17A and the enzyme PTGS2 by CXCL1 was also observed.

Implications

• The study suggests that differences in expression of these proinflammatory mediators could influence the types of leukocytes (white blood cells) recruited to the site of inflammation, potentially affecting membrane separation.
• The abundance of macrophages (a type of immune cell) in the placenta of mares could be a significant factor during normal expulsion of the fetal membranes.
• It is also hypothesized that the synthesis of PTGS2, an enzyme involved in producing molecules that stimulate inflammation and pain, might be inhibited in mares with RFM, which could contribute to the disease.