ATI-2341 TFA promotes acquisition of epithelial-like immunophenotype in bone marrow mesenchymal stem cells and alleviates intrauterine adhesion in a rat model

Abstract: Background: Intrauterine adhesion (IUA) is a common complication of endometrial injury. Bone marrow mesenchymal stem cells (BMSCs) have been implicated in endometrial repair, but strategies to enhance their therapeutic efficacy remain to be optimized. The C-X-C chemokine receptor type 4 (CXCR4)/C-X-C motif chemokine ligand 12 (CXCL12) axis plays a pivotal role in BMSC homing. Objective: This study aimed to test the hypothesis that ATI-2341, a functionally selective allosteric regulator of CXCR4, enhances the therapeutic efficacy of BMSCs in a rat IUA model. Methods: After establishing the endometrial injury model, rat BMSCs were extracted and treated with ATI-2341 TFA (100 ng/mL). IUA model rats were randomly divided into model control group, BMSCs group, BMSCs+ATI-2341 TFA group, BMSCs+PBS group and Positive control group (n=10 each). Endometrial thickness was assessed by hematoxylin and eosin (HE) staining; cell proliferation by the methyl thiazolyl tetrazolium (MTT) assay; matrix metalloproteinase-9 (MMP-9)/tissue inhibitor of metalloproteinase-1 (TIMP-1) protein expression by Western blot; and cytokeratin and vimentin expression by immunohistochemistry. Results: ATI-2341 TFA-pre-treated BMSCs significantly increased endometrial thickness compared to untreated BMSCs (P < 0.05) or estrogen (P < 0.05). ATI-2341 TFA enhanced BMSC proliferation at 48 h (P < 0.05) and 72 h (P < 0.05). BMSCs exposed to ATI-2341 TFA or estrogen exhibited strong cytokeratin positivity and vimentin negativity. MMP-9 was downregulated (P < 0.05) and TIMP-1 upregulated (P < 0.05) in the ATI-2341 TFA group relative to controls. Conclusion: ATI-2341 TFA promotes acquisition of epithelial-like immunophenotype in BMSCs within the injured endometrial microenvironment and is associated with improved endometrial morphology in IUA rats. These findings provide preliminary evidence for the functional modulation of BMSCs by CXCR4-targeted therapy in endometrial repair.