Modèles animaux dans la recherche expérimentale sur l’endométriose

A protocol for creating endometriosis in rhesus macaques (Macaca mulatta)

BACKGROUND

Endometriosis is the presence of endometrium-like tissue outside the uterine cavity. An experimental model of endometriosis has been created in the baboon by the transcervical collection and laparoscopic inoculation of menstrual endometrium. Macaques are the preferred model for pharmaceutical development, but the complex anatomy of the macaque cervix makes the baboon method impractical. In this work, we sought to validate a surgical approach for creating endometriosis in macaques.

METHODS

Menstrual endometrium was collected via laparoscopic intrauterine puncture and transferred to the peritoneal cavity. We repeated this procedure during three menstruations. Endometriotic tissue was identified during laparoscopy, collected, and characterized by immunohistochemistry.

RESULTS

Sham surgery-treated animals (n = 3) failed to develop endometriosis. We identified red, powder burnt, and white lesions in 13/14 of the treated animals; the stroma of the red lesions stained positive for ovarian steroid receptors.

CONCLUSION

This surgical technique can reliably create hormone-responsive endometriosis in macaques for therapeutic studies.

Correlation between endometriomas volume and Raman spectra. Attempting to use Raman spectroscopy in the diagnosis of endometrioma

The formation of the uterus lining, i.e. the endometrium, outside the uterus (ex. in the abdominal cavity,ovaries,or anywhere in the body) is called endometriosis. The presence of endometrial tissue present in the ovaries, thickens after menstruation, leading to menstrual-like bleeding and to the formation of chocolate cyst (Endometrioma) because of the accumulation of old, brown blood in the ovary. It is still unknown, what triggers the development ofendometrioma. However,it leads to excessive bleeding during menstrual periods or abnormal bleeding between periods and infertility. Endometriosis is often first diagnosed in those who seek medical attention for infertility. Therefore, new markers of endometrioma as well as new methods of its diagnosis are sought. In this study we used Raman spectra of serum collected from 50 healthy women and 50 women suffering from endometriosis. The obtained Raman data were used in multivariateanalysis to determine the Raman range, which can be used for endometriomadiagnostics. Partial Least Square (PLS), Principal Component Analysis (PCA) and Hierarchical Component Analysis (HCA) showed, that it is possible to distinguish between the serum collected from healthy and un-healthy women using the Raman range between 800 cm^-1 and 1800 cm^-1 and between 2956 cm^-1 and 2840 cm^-1, while the first range corresponds to the fingerprint region and the second one to lipids vibrations. Consequently, the Pearson correlation test showeda significantpositive correlation betweenvaluesoflipidintensity in Raman spectra and volume of endometriomas. Summarizing, Raman spectroscopy can be a helpful tool in endometrioma diagnosis and the lipid vibrations are candidates for being a spectroscopic marker of the disease being studied.

Endometriosis: current challenges in modeling a multifactorial disease of unknown etiology

Endometriosis is a chronic inflammatory hormone-dependent condition associated with pelvic pain and infertility, characterized by the growth of ectopic endometrium outside the uterus. Given its still unknown etiology, treatments usually aim at diminishing pain and/or achieving pregnancy. Despite some progress in defining mode-of-action for drug development, the lack of reliable animal models indicates that novel approaches are required. The difficulties inherent to modeling endometriosis are related to its multifactorial nature, a condition that hinders the recreation of its pathology and the identification of clinically relevant metrics to assess drug efficacy. In this review, we report and comment endometriosis models and how they have led to new therapies. We envision a roadmap for endometriosis research, integrating Artificial Intelligence, three-dimensional cultures and organ-on-chip models as ways to achieve better understanding of physiopathological features and better tailored effective treatments.

Animal Models in Endometriosis Research

The initiation of endometriosis in women is difficult to investigate, because there is usually a delay of several years from the onset of lesion development to the clinical diagnosis. Animal models of endometriosis, on the other hand, provide an important contribution to the investigation of the disease pathogenesis and the efficacy of therapeutic intervention strategies.

Effect of induced peritoneal endometriosis on oocyte and embryo quality in a mouse model

PURPOSE

To assess the impact of peritoneal endometriosis on oocyte and embryo quality in a mouse model.

METHODS

Peritoneal endometriosis was surgically induced in 33 B6CBA/F1 female mice (endometriosis group, N = 17) and sham-operated were used as control (sham group, N = 16). Mice were superovulated 4 weeks after surgery and mated or not, to collect E0.5-embryos or MII-oocytes. Evaluation of oocyte and zygote quality was done by immunofluorescence under spinning disk confocal microscopy.

RESULTS

Endometriosis-like lesions were observed in all mice of endometriosis group. In both groups, a similar mean number of MII oocytes per mouse was observed in non-mated mice (30.2 vs 32.6), with a lower proportion of normal oocytes in the endometriosis group (61 vs 83 %, p < 0.0001). Abnormalities were incomplete extrusion or division of the first polar body and spindle abnormalities. The mean number of zygotes per mouse was lower in the endometriosis group (21 vs 35.5, p = 0.02) without difference in embryo quality.

CONCLUSIONS

Our results support that induced peritoneal endometriosis in a mouse model is associated with a decrease in oocyte quality and embryo number. This experimental model allows further studies to understand mechanisms of endometriosis-associated infertility.