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Endometriosis (EMs) animal model

Endometriosis (EMs) animal model

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Endometriosis
Reproductive system disease model

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Model Introduction

Model Introduction

Platform Service Advantages

Platform Service Advantages

Experimental results

Experimental results

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Endometriosis

Introduction to EMs Animal Models

Endometriosis (EMS) is a benign proliferative disorder that is estrogen‑dependent, progesterone‑resistant, and characterized primarily by chronic pelvic inflammation. Its core pathological features include ectopic endometrial implantation, remodeling of the inflammatory microenvironment, enhanced angiogenesis, and aberrant macrophage infiltration. In both basic research and drug development, model stability and phenotypic consistency directly determine the reliability of efficacy assessments.

Service Advantages of the Aniphe BioLab EMs Animal Model Platform

Relying on its well-established research platform for gynecological diseases, Aniphe BioLab offers clients robust and reliable services for the establishment of endometriosis (EMs) models and for pharmacological efficacy evaluation, thereby supporting drug development and mechanistic studies in this field.

Comprehensive model coverage

The modeling protocol is well-established.

Supports multiple classic modeling approaches, including autologous transplantation, to meet diverse research needs.

Standardization of the modeling process

The model is stable and reliable.

It can stably establish ectopic lesions, thereby effectively mimicking the pathological features of clinical endometriosis.

Multidimensional Evaluation System

The lesion evaluation system has been refined.

It encompasses the measurement of lesion volume, histopathological analysis, and the assessment of key parameters such as angiogenesis.

Adapted for multi-cycle studies

Comprehensive mechanistic research capabilities

Supports the detection of inflammatory cytokines, hormone levels, immune regulatory markers, and fibrosis-related indicators.

Adapted for multi-cycle studies

Flexible scheme design

Based on the drug’s mechanism of action and research objectives, tailor personalized experimental protocols and evaluation frameworks.

Adapted for multi-cycle studies

Data quality is guaranteed.

Standardized end-to-end operations and QA management ensure that experimental data are authentic, reliable, and traceable.

Adapted for multi-cycle studies

One-stop research services

We provide end-to-end support, including model development, efficacy evaluation, sample analysis, data interpretation, and report generation.

Modeling cycle

About one week

1  Laboratory animals

Female Balb/c mice

1  Positive drug

Commonly used progestational agents include GnRH agonists such as leuprorelin acetate and goserelin, as well as clinically established treatments like dienogest and gestrinone.

1  Application areas

Endometriosis models are primarily used in basic research on disease pathogenesis (a core foundational area), in the study of complication‑related pathology, and in new drug development and efficacy evaluation (the most significant translational application area), as well as in assessments of drug safety and toxicology, and in the evaluation of biomarkers and prognosis.

Experimental results

Construction of an animal model of endometriosis

This model employs an orthotopic implantation technique, whereby endometrial tissue is adhered to the peritoneal surface of the abdominal wall, combined with exogenous estrogen administration, to mimic the survival and proliferation of ectopic endometrium within the peritoneal cavity.

Estrous cycle synchronization to minimize variability in donor sources: Seven days prior to model induction (D‑7), donor mice were pre‑treated with subcutaneous injections of estradiol benzoate. For five consecutive days, daily vaginal smears were performed to monitor the estrous cycle; on the day of tissue collection, uteri from donors exhibiting proestrus or estrus phases on the smear were selected, ensuring that all donor endometria were at a consistent physiological stage and thereby reducing inter‑animal heterogeneity in model establishment and variability in lesion size attributable to cyclical fluctuations.

Modeling ectopic implantation in the abdominal wall: The donor uterus was aseptically isolated, and fragments of endometrium were excised. The functional surface was oriented toward the peritoneal cavity and adhered to the inner surface of the recipient mouse’s abdominal wall, with precise alignment and suturing. Postoperatively, estradiol benzoate was administered intraperitoneally according to the experimental protocol to mimic a high‑estrogen microenvironment, thereby supporting the engraftment, proliferation, and angiogenesis of the ectopic lesions.

References:

[1] Cao Yuzhen, Chen Yuying, Huang Biqi, et al. Study on the effects of Bifidobacterium breve on endometriosis in mice [J]. PLA Journal of Medicine, 2026, 51(1): 86–93.

[2] Jiang Ying. Mechanistic Study on How Abdominal Microbiota Dysbiosis Promotes the Development of Endometriosis by Regulating Macrophage Phospholipid Metabolism via PLPP3 [D]. Central South University, 2025. DOI: 10.27661/d.cnki.gzhnu.2025.000552.

 

Establishment and Validation of the EMS Mouse Model

Oestrus cycle synchrony was excellent: vaginal smears from the donor mice confirmed synchronous oestrus cycles, ensuring temporal consistency in endometrial sampling and minimizing the impact of cyclical variability on model establishment.

Typical findings in ectopic lesions: Following model establishment, newly formed blood vessels were observed on the surface of the transplanted endometrium and in the adjacent areas across all groups. The ectopic foci appeared as transparent or semi‑transparent vesicles containing clear fluid, with a dark red or brown hue. Macroscopic morphology was consistent with the characteristic features of typical endometriosis lesions, indicating successful model construction.

Hematoxylin–eosin (HE) staining revealed viable tissue and inflammatory infiltration: HE-stained sections of the transplanted tissue showed intact endometrial glands and stromal cells, accompanied by infiltrating inflammatory cells, suggesting that the ectopic endometrium possesses tissue‑survival capacity and is associated with an activated inflammatory response.

 

 

 

Pharmacological efficacy evaluation system

1. Body weight changes: Following model induction, the body weights of mice in the G2 and G4 groups decreased significantly compared with those in the G1 control group (P<0.05), then gradually recovered to levels close to normal; no significant difference was observed between the G3 group and the G1 group (P>0.05). Each group n=6. In the figure, *P<0.05, **P<0.01, ***P<0.001.

2. Morphological Comparison of Lesions: Gross examination of the tissue samples revealed that both G3 (Positive Control 1) and G4 (Positive Control 2) interventions reduced the volume of ectopic lesions, with the G4 group demonstrating a more pronounced reduction in lesion number and intra-abdominal adhesion severity compared to the model group.

3. Histological differences in HE staining: Ectopic lesions—In the G2 model group, the tissue architecture was disorganized, with numerous abnormal cystic spaces and scattered hemorrhagic foci; in the G3 intervention group, large vacuoles containing clear fluid were frequently observed at the lesion centers, accompanied by some hemorrhage; in the G4 intervention group, the number of cystic spaces was reduced and their extent was diminished, with hemorrhage markedly alleviated compared to the model group. Endometrium: Intervention with Positive Control 1 decreased the incidence of endometrial bleeding and reduced the number of glands with abnormal morphology; intervention with Positive Control 2 significantly improved glandular morphology, bringing it closer to the normal endometrial structure.

 

 

4. Immunohistochemistry (Iba-1, a marker of macrophage infiltration)

Iba-1 (ionized calcium-binding adapter molecule 1) is a commonly used marker for macrophages, reflecting the degree of macrophage infiltration in tissues.

Ectopic lesions: In the G2 model group, the proportion of Iba-1–positive cells was significantly higher than in the G3 (P<0.001) and G4 (P<0.001) intervention groups.

Endometrium: The proportion of positive cells in the G2 model group was significantly higher than that in the G1 control group (P<0.001); the G3 intervention group and the G4 intervention group showed significant reductions compared with the G2 group (G3: P<0.01; G4: P<0.001).

5. Inflammatory cytokine assay (ELISA)

ELISA analysis of peritoneal lavage fluid revealed that the levels of IL-6, TNF-α, and IL-1β in the G3 and G4 intervention groups were significantly lower than those in the G2 model group (P<0.001).

 

 

 

Model Features

This model possesses the following core advantages:

01 High stability and homogeneity: Oestrus cycle synchronization and the maintenance of oestrogen levels together ensure consistency in lesion size and growth status.

02 Controllable cycle: The entire process lasts approximately six weeks, and once the model is established, pharmacological efficacy can be reliably assessed.

03 Complete pathological phenotype: It encompasses the major phenotypes of endometriosis, including ectopic implantation, angiogenesis, pelvic adhesions, inflammatory infiltration, and abnormal tissue architecture.

04 Multi-level Evaluation: Integrating gross morphology, histopathology, immunohistochemistry, and inflammatory cytokine assays facilitates cross-validation and retrospective analysis of results.

 

Summary of Experience

01 Donor synchronization and the stable maintenance of exogenous estrogen are central to the uniformity of the model.

02 The stability of the surgical procedure determines the consistency of the implantation site and size of ectopic lesions.

03 Strict alignment of dosing parameters (timing, dose, and route) is a prerequisite for the comparability of pharmacological effects.

04 Maintaining low temperatures throughout the entire sample-processing workflow is fundamental to ensuring the reliability of downstream data in assays such as ELISA and immunohistochemistry.

05 End-to-end documentation—including estrous cycle smears, surgical records, medication administration logs, and schematic diagrams of tissue sampling sites—serves as a critical safeguard for model reproducibility.