Sphingolipid Dysregulation in Impaired Spermatogenesis: Azoospermic Mouse Model

Azoospermia is a severe form of male fertility characterized by the absence of sperm in the ejaculate. Sphingolipids regulate essential cellular processes, including differentiation and apoptosis, with ceramide and sphingosine functioning as key bioactive signaling molecules. This study investigated sphingosine levels and ceramide subtype profiles in the testicular tissue of mice across distinct spermatogenic states, including immature, normal mature, and azoospermic conditions.

In this experimental study, 24 NMRI mice were randomly allocated into three equal groups (n=8): i. Immature (2 weeks old), ii. Normal mature (8 weeks old), and iii. Azoospermic (8 weeks old), the latter induced by a single intraperitoneal injection of busulfan (40 mg/kg). Following histopathological evaluation, sphingosine and ceramide concentrations in testicular tissue were quantified using high-performance liquid chromatography (HPLC). Statistical analysis was performed using one-way analysis of variance (ANOVA), followed by appropriate posthoc tests for group comparisons.

Significant differences in sphingosine and ceramide concentrations were observed among the experimental groups. Sphingosine levels were highest in normal mature mice, followed by azoospermic and immature groups (P<0.001). A similar overall pattern was observed for most ceramide subtypes (Cer14, Cer18, and Cer20), which were significantly elevated in normal mature mice compared with the other groups. In contrast, Cer16 showed a distinct pattern, with reduced levels in azoospermic mice compared with immature animals (P<0.001).

Alterations in specific sphingolipid metabolites are associated with spermatogenic status and may contribute to the pathophysiology of male infertility. Disruption of sphingosine and ceramide homeostasis may impair reproductive function, supporting their potential utility as biomarkers and therapeutic targets in azoospermia..