Comprehensive transcriptome analysis based on RNA sequencing identifies critical genes for lipopolysaccharide-induced epididymitis in a rat model

Epididymitis is a commonly diagnosed disease associated with male infertility. However, little is known about the molecules that are involved in its development. This study was to identify critical genes associated with lipopolysaccharide-induced epididymitis and analyze the molecular mechanism of epididymitis through RNA sequencing. Experimental epididymitis models were generated by administering male Sprague–Dawley rats' lipopolysaccharide. A total of 1378 differentially expressed genes, including 531 upregulated and 847 downregulated genes, were identified in the epididymitis model rats compared with those in sham-operated rats by RNA sequencing. Functional enrichment analyses suggested that the upregulated genes were markedly enriched in inflammation-related biological processes, as well as in the tumor necrosis factor (TNF) signaling pathway, cytokine–cytokine receptor interactions, complement and coagulation cascades, and in the chemokine signaling pathway. Four downregulated genes (collagen type XXVIII alpha 1 chain [Col28α1], cyclin-dependent kinase-like 1 [Cdkl1], phosphoserine phosphatase [Psph], and fatty acid desaturase 2 [Fads2]) and ten upregulated genes (CCAAT/enhancer-binding protein beta [Cebpβ], C-X-C motif chemokine receptor 2 [Cxcr2], interleukin 11 [Il11], C-C motif chemokine ligand 20 [Ccl20], nuclear factor-kappa-B inhibitor alpha [Nfkbiα], claudin 4 [Cldn4], matrix metallopeptidase 9 [Mmp9], heat shock 70 kDa protein 8 [Hspa8], intercellular cell adhesion molecule-1 [Icam1], and Jun) were successfully confirmed by real-time polymerase chain reaction. Western blot demonstrated that CDKL1 was decreased, while MMP9 and NFKBIA were increased in the experimental model group compared with those in the sham-operated group. Our study sheds new light on the understanding of the early response of the epididymis during bacterial epididymitis.