Collagen and Eosinophils in Jenny's Endometrium: Do They Differ With Endometrial Classification?

Abstract

Collagen fibers and inflammatory cells are the basis for jenny endometrium Kenney and Doig's classification developed for the mare. The infiltration of a large number of eosinophils in the jenny endometrium is intriguing. Eosinophil and fibroblast produced IL33, which has been related to fibrosis development and chronicity. This work on the endometrium consisted of (i) quantification of collagen type I (COL1A2), type III (COL3A1), and IL33 transcripts; (ii) histological localization and quantification of COL1 and COL3 proteins; and (iii) eosinophil and neutrophil count and correlation with collagen area and IL33 transcripts. Localization of COL protein in the jenny endometrium was also compared to the mare endometrium. As fibrosis increased, eosinophil and neutrophil count decreased ( P < 0.05). A 5-fold increase in IL33 transcripts was noted from categories IIA to III. There was a tendency toward a positive correlation between eosinophil count and IL33 transcripts in category IIA endometrium ( P = 0.055). Neither transcripts of COL1A2 nor COL3A1 nor the areas of COL1 or COL3 differed with endometrial categories. Unlike for the mare, and regardless of the jenny endometrium classification, COL3 was always found to different extents in the stratum compactum, while COL1 was mainly present in deep stroma. As fibrosis progressed in the mare, an extensive increase in COL1 fibers was notorious under the surface epithelium. Correlations between neutrophil count and COL1 and COL3 areas were observed in the jenny endometrium, although no correlation was found for eosinophil count. Neutrophil count positive correlation with the COL1 area and negative correlation with the COL3 area in endometria with mild lesions suggest that neutrophils in the jenny endometrium may be involved in fibrogenesis. In addition, when eosinophilia subsides, the endometrium reacts with fibrosis establishment, which could be stimulated by the pro-fibrotic cytokine IL33, whose release might then be ascribed to fibroblasts. Further studies are needed to analyze the effect of the presence of COL3 next to the surface epithelium in the stratum compactum, or around the endometrial glands on jenny's endometrial function and fertility.

Extracellular Reactive Oxygen Species (ROS) Production in Fresh Donkey Sperm Exposed to Reductive Stress, Oxidative Stress and NETosis

“…Be that as it may, NETosis is capable of producing an immense amount of ROS, which, in the long run, and if occurs repeatedly and/or excessively, can presumably contribute to chronic inflammation of the donkey endometrium and even end in fibrosis [ 62 ]. The action mechanism through which ROS production occurs by NETosis still raises several questions.…”

Seminal plasma, and not sperm, induces time and concentration‐dependent neutrophil extracellular trap release in donkeys

“…Although post‐mating endometritis is a physiological event, and may even play a positive role in the establishment and maintenance of pregnancy, 43,44 infertile jennies have been observed to exhibit persistent post‐breeding endometritis, some of them even presenting a fibrotic progression 45 . Interestingly, AI with frozen semen increases the number of neutrophils infiltrated into the uterine lumen of mares in comparison with fresh semen 46 .…”

Simple Tube Centrifugation Method for Platelet-Rich Plasma (PRP) Preparation in Catalonian Donkeys as a Treatment of Endometritis-Endometrosis

“…With this protocol, the PRP also presented an acceptable concentration of TGF-β1 as a growth factor sentinel, possibly providing enough volume and therapeutic potential for use in damaged jenny endometrium. It should be noted that there are important differences between jenny and mare endometritis and endometriosis [11], and that platelets and cytokine concentrations showed different effects (positive or adverse) in other tissues [41,[47][48][49]. Further studies are necessary to optimize the jenny endometritis-endometriosis treatment by PRP.…”

“…Despite endometrial susceptibility, jenny endometritis seems to have its specific particularities, especially in the progression towards endometriosis. Inflammatory cells such as PMNs and eosinophils differ in timing and abundance, and there are also significant differences in the collagen distribution between jenny and mare [11].…”