Effects of Interleukin-6 (IL-6) on In Vitro Cultured Equine Chorionic Girdle Cells

Area of Science:

• Reproductive biology
• Endocrinology
• Cell biology

Background:

• Equine chorionic girdle cells form endometrial cups, secreting equine chorionic gonadotropin (eCG).
• Mechanisms of equine chorionic girdle cell proliferation, differentiation, invasion, and hormone secretion are not fully understood.
• Interleukin-6 (IL-6) is upregulated during equine placentation, but its effects on equine chorionic girdle cells are unknown.

Purpose of the Study:

• To investigate the effects of IL-6 on equine chorionic girdle cell morphology, differentiation, proliferation, hormone production, invasion, migration, and gene expression.
• To elucidate the role of IL-6 in equine pregnancy.

Main Methods:

• Equine chorionic girdle cells were treated with varying concentrations of IL-6.
• Morphology, proliferation, eCG production (gene expression, protein levels, secretion), cell migration, and invasion were assessed.
• Transcriptomic analysis was performed to identify affected signaling pathways.

Main Results:

• IL-6 did not significantly affect cell morphology or proliferation.
• IL-6 at 30 ng/mL increased eCG-related gene expression, while 70 ng/mL downregulated it; no significant changes in eCG protein or secretion were observed.
• IL-6 enhanced equine chorionic girdle cell invasion and upregulated Mmp2 and Mmp9 gene expression, but did not affect migration.
• Transcriptomic analysis revealed IL-6 primarily impacted NOD-like receptor and JAK-STAT signaling pathways.

Conclusions:

• IL-6 positively influences the invasive ability of equine chorionic girdle cells.
• IL-6 affects cytokine secretion and impacts key signaling pathways involved in immune and inflammatory responses in equine chorionic girdle cells.