Equine endometrial fibrosis correlates with 11beta-HSD2, TGF-beta1 and ACE activities.

The researchers conducted a study on equine endometrial fibrosis (EPF), a contributing factor to embryonic and fetal loss in mares. They found a strong correlation between the severity of EPF and the activities of angiotensin-converting enzyme (ACE), transforming growth factor-beta 1 (TGF-beta1), and 11beta-hydroxysteroid dehydrogenase type 2 (11β-HSD2).

Investigating Equine Endometrial Fibrosis

• The study focused on endometrial periglandular fibrosis (EPF), a condition in mares that affects conception and successful gestation. It is linked to embryonic and fetal loss.
• The researchers used the modified Kenney endometrial biopsy classification system to categorize the severity of EPF. This system classifies the severity of the condition from minimal (category I) to severe (category III), and also includes an inflammation indicator.
• To examine the condition, biopsy specimens were taken and stained. The researchers measured the endometrial ACE-binding activity, TGF-beta1, and 11beta-HSD2 activities in each.

Findings

• The study found significant ultrastructural changes in tissues from categories IIB and III, indicative of a myofibroblastic transformation. Myofibroblasts are cells that play a key role in wound healing and fibrosis.
• ACE-binding activity was found to be highest in tissues from category IIB of EPF. However, TGF-beta1 and 11beta-HSD2 activities were found to correlate with the severity of EPF, indicating that these factors increase as the condition becomes more severe.

Conclusions

• The researchers concluded that angiotensin II, generated locally, initiates the expression of TGF-beta1, thereby resulting in the transformation of cells into myofibroblasts.
• The study further suggests that 11Beta-HSD2 modulates the severity of endometrial fibrosis, thus presenting a potential target for treatment efforts.

The results of this study present new insights into the pathophysiology of equine endometrial fibrosis and potential avenues for therapeutic interventions.