Research Article | 06 Jul 2026

Proteomic profiling of isolated mouse endometrial epithelial cells reveals coordinated redox and endoplasmic reticulum stress-associated pathways during uterine receptivity

Jakree Jitjumnong^1,2,3

, Wilasinee Inyawilert^4,5

, Attapol Tiantong⁶

, Shih-Han Wang⁷

, Chao-Jung Chen^8,9, Yu-Jing Liao¹⁰, Tossapol Moonmanee^1,2

, San-Yuan Huang^11,12,13

, and Pin-Chi Tang^11,12

1. Department of Animal and Aquatic Sciences, Faculty of Agriculture, Chiang Mai University, Chiang Mai 50200, Thailand.

2. Functional Feed Innovation Center, Faculty of Agriculture, Chiang Mai University, Chiang Mai 50200, Thailand.

3. Center of Omics for High-Value Agriculture (AgOmics-CMU), Faculty of Agriculture, Chiang Mai University, Chiang Mai 50200, Thailand.

4. Department of Agricultural Science, Faculty of Agriculture, Natural Resources and Environment, Naresuan University, Phitsanulok 65000, Thailand.

5. The Center of Agricultural Biotechnology, Naresuan University, Phitsanulok 65000, Thailand.

6. Faculty of Animal Sciences and Agricultural Technology, Silpakorn University, Phetchaburi IT Campus, Cha-Am, Phetchaburi 76120, Thailand.

7. Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan.

8. Proteomic Core Laboratory, Department of Medical Research, China Medical University Hospital, Taichung 40447, Taiwan.

9. Graduate Institute of Integrated Medicine, China Medical University, Taichung 40402, Taiwan.

10. Genetics and Physiology Division, Taiwan Livestock Research Institute, Ministry of Agriculture, Tainan 71246, Taiwan.

11. Department of Animal Science, National Chung Hsing University, Taichung 40227, Taiwan.

12. The iEGG and Animal Biotechnology Research Center, National Chung Hsing University, Taichung 40227, Taiwan.

13. Professional Master Program of Agricultural Business Management, National Chung Hsing University, Taichung 40227, Taiwan.

Corresponding author: San-Yuan Huang and Pin-Chi Tang (syhuang@dragon.nchu.edu.tw and pctang@dragon.nchu.edu.tw)

Received: 20-02-2026 , Accepted: 21-05-2026 , Published: 06-07-2026

VETERINARY WORLD | Article No. 4 | pg no. 2734-2750 | Vol. 19, Issue 7 | DOI: 10.14202/vetworld.2026.2734-2750

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ABSTRACT

Background and Aim: Uterine receptivity is critical for successful embryo implantation, yet epithelial-specific proteomic changes during this transition remain incompletely characterized. This study aimed to profile changes in protein expression in isolated mouse endometrial epithelial cells between the pre-receptive (Day 1) and receptive (Day 4) phases of pregnancy to identify key pathways associated with uterine receptivity.

Materials and Methods: Endometrial epithelial cells were isolated from pregnant CD-1 mice on Days 1 and 4 of pregnancy. Protein extracts were analyzed using two-dimensional gel electrophoresis followed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for identification. Differentially expressed proteins were functionally annotated using Gene Ontology. Key candidates, including Gstm2 and vimentin, were validated by immunofluorescence and quantitative real-time polymerase chain reaction.

Results: Approximately 674 protein spots were detected, of which 80 were differentially expressed (p < 0.05, ≥2-fold change) and 52 were successfully identified. These proteins were primarily associated with cellular metabolism, redox regulation, protein folding, and endoplasmic reticulum (ER) stress responses. Coordinated upregulation of antioxidant proteins (Gstm2, Gstm7, Prdx2, Cat) and ER stress-associated proteins (PDIA3, HSPA5) was observed on Day 4. Gstm2 showed consistent upregulation at both protein and transcript levels (p < 0.05) with enhanced epithelial localization, while vimentin expression remained stable, supporting cytoskeletal readiness. These changes indicate integrated redox homeostasis and stress adaptation during the acquisition of uterine receptivity.

Conclusion: This epithelial-specific proteomic analysis reveals coordinated redox and ER stress-associated pathways during the transition to uterine receptivity in mice. The findings provide a focused proteome resource that highlights Gstm2 as a candidate regulator within antioxidant networks and establishes a foundation for understanding molecular mechanisms at the embryo–maternal interface.

Keywords: endometrial receptivity, endoplasmic reticulum stress, gstm2, implantation, mouse uterus, proteomics, redox regulation, uterine epithelium