Developmental Phase-Specific Molecular Signatures and Signaling Pathways in Cryptorchidism-Induced Testicular Damage.

Cryptorchidism, characterized by undescended testes, is associated with infertility and increased cancer risk through complex, multifactorial pathophysiological mechanisms involving interconnected alterations in testicular microenvironment, including but not limited to elevated temperature, hormonal dysregulation, altered vascular perfusion, and immune responses. These factors interact synergistically to drive testicular pathology. Using a surgically induced bilateral cryptorchid mouse model established at postnatal day 21 (PND21), we investigated phase-specific pathological mechanisms through analyses at prepubertal (PND35) and sexually mature (PND70) phases. Our transcriptome analysis revealed distinct molecular signatures at different developmental phases, with prepubertal cryptorchid testes showing 2570 differentially expressed genes predominantly enriched in immunoproteasome components and inflammatory pathways, while sexually mature testes exhibited 883 differentially expressed genes primarily related to extracellular matrix (ECM) remodeling and oncogenic pathways. Prepubertal molecular changes indicated immunoproteasome activation and inflammatory responses, whereas mature-phase alterations were characterized by ECM reorganization and fibrotic remodeling. Functional analysis demonstrated prepubertal enrichment in spermatogenesis regulation and interferon responses, while mature-phase signatures were associated with apoptosis, epithelial-mesenchymal transition, and inflammatory signaling cascades. Phase-specific oncogenic pathway correlations revealed distinct mechanisms: metabolic reprogramming and epigenetic regulation in prepubertal testes versus structural remodeling and invasion-related pathways in mature testes. Molecular validation confirmed elevated PI3K-Akt and NF-κB signaling at both developmental phases, identifying these as potential therapeutic targets. This first phase-resolved characterization of cryptorchidism pathology provides insights into developmental phase-specific mechanisms and suggests timing-dependent therapeutic strategies. Although differing from human congenital cryptorchidism in developmental timing and etiology, our surgically induced model recapitulates anatomical testicular malposition with multiple inseparable pathophysiological alterations, and the identified molecular signatures reflect integrated responses to the complex cryptorchid microenvironment.