Effects of Wharton’s jelly mesenchymal stromal/stem cells-derived conditioned medium and platelet-rich plasma on in vitro induced equine endometrial inflammation.

Research Overview

• This study investigated how two regenerative treatments—Wharton’s jelly mesenchymal stem cell-derived conditioned medium (WJ-CM) and platelet-rich plasma (PRP)—affect equine endometrial cells in vitro, both with and without inflammation induced by lipopolysaccharide (LPS).
• The goal was to assess whether these treatments could protect or improve the health of endometrial cells, which are important for uterine function in mares, especially under inflammatory conditions that often impair fertility.

Background and Motivation

• Persistent breeding-induced endometritis is a common reproductive problem in horses that leads to inflammation of the uterine lining and can reduce fertility.
• Regenerative therapies like mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP) have shown potential in treating inflammatory conditions by promoting healing and modulating immune responses.
• Wharton’s jelly (a substance within the umbilical cord) is a rich source of MSCs, and their conditioned medium (the fluid containing factors secreted by MSCs) may harbor beneficial factors.
• Despite promise, there is limited in vitro research on how these therapies specifically affect equine endometrial cells, especially under inflammatory stress.

Experimental Design

• Endometrial epithelial cells were isolated from the uteri of three diestrus-stage mares obtained from a slaughterhouse.
• Six treatment groups were tested over 24 hours:
  • CTRL: Standard culture medium (DMEM) as a control
  • LPS: Medium with 10 ng/mL lipopolysaccharide to induce inflammation
  • CM: Medium with 10% WJ-MSC conditioned medium (WJ-CM) alone
  • PRP: Medium with 5% platelet-rich plasma alone
  • LPS + CM: Medium with both 10 ng/mL LPS and 10% WJ-CM
  • LPS + PRP: Medium with both 10 ng/mL LPS and 5% PRP
• Cells were assessed at 6, 12, and 24 hours for:
  • Viability, including apoptosis (programmed cell death) and necrosis
  • Mitochondrial activity, indicating cell metabolic function
  • Reactive oxygen species (ROS) generation, a marker of oxidative stress
  • Concentrations of inflammatory and anti-inflammatory mediators in the culture medium:
    • Prostaglandin E2 (PGE-2), generally pro-inflammatory
    • Interleukin-10 (IL-10), an anti-inflammatory cytokine

Key Findings: Effects of WJ-CM

• WJ-CM alone did not negatively affect the viability of endometrial cells, indicating it is not toxic under these conditions.
• When cells were exposed to LPS (inflammatory challenge), WJ-CM prevented the negative effects on cell viability seen with LPS alone.
• The treatment with WJ-CM suppressed the production of PGE-2, suggesting an anti-inflammatory effect.
• These results indicate that WJ-CM has protective and potentially therapeutic benefits for equine endometrial cells during inflammation.

Key Findings: Effects of PRP

• In contrast to WJ-CM, PRP had a detrimental effect on the viability of endometrial cells, reducing cell health even without added inflammation.
• PRP induced the secretion of PGE-2, which typically promotes inflammation.
• PRP increased mitochondrial activity and ROS production, suggesting heightened metabolic stress and oxidative damage.
• Surprisingly, PRP did not protect the cells from LPS-induced inflammation and instead showed deleterious effects under the conditions tested.

Implications and Conclusions

• WJ-MSC-derived conditioned medium shows promise as a regenerative treatment for equine endometrial inflammation, demonstrating protective effects against LPS-induced damage in vitro.
• PRP, commonly used in regenerative medicine, unexpectedly showed harmful effects on equine endometrial cells in this model, indicating that its use in treating endometrial inflammation should be carefully reconsidered or further studied.
• These findings contribute to understanding the cell-specific responses to regenerative products and could guide future therapeutic applications for improving mare fertility affected by endometrial inflammation.