Integrated single-cell and bulk transcriptomic analyses reveal UTF1-associated spermatogenic dysfunction and identify ACTRT2 and AKAP4 as biomarkers in non-obstructive azoospermia

Introduction Non-obstructive azoospermia (NOA) is a severe male infertility disorder caused by spermatogenic failure, and UTF1 is critical for maintaining undifferentiated spermatogonia and regulating germ cell development. This study aimed to explore the role of UTF1-related spermatogenic dysfunction in NOA and identify potential diagnostic biomarkers. Methods We integrated NOA transcriptomic datasets with single-cell RNA sequencing (scRNA-seq) data from Utf1 conditional knockout and normal mouse testes. Bioinformatic analyses and machine learning were applied to screen biomarkers, while functional enrichment, immune infiltration, cell-cell communication, and pseudotime trajectory analyses were performed together with histological validation in Utf1-deficient testes. Results Spermatogonia, Sertoli cells, and spermatids were identified as key cell populations. ACTRT2 and AKAP4 were confirmed as consistently downregulated NOA biomarkers and were integrated into a well-calibrated nomogram. These two genes were associated with cytoskeletal remodeling and meiotic regulation. NOA was also characterized by altered immune infiltration and cell-cell communication, whereas Utf1 deficiency impaired testicular development and spermatogenesis. Discussion Collectively, UTF1 deficiency was closely associated with spermatogenic dysfunction and microenvironmental remodeling in NOA, while ACTRT2 and AKAP4 might serve as potential diagnostic biomarkers of this process. These findings provide new insights into the molecular basis of NOA and may support future disease stratification and targeted intervention strategies.