Transcriptional activation and regulation of urokinase plasminogen activator inducted by LPS through MyD88 independent pathway in rat Sertoli cells.

Introduction: Urokinase plasminogen activator (uPA) is a serine protease and it also demonstrates proinflammatory properties. We thus hypothesized that uPA is involved in immunity of Sertoli cells in the rat testis.

Materials and methods: The uPA gene(PLAU) promoter was cloned by RT-PCR and the transcriptional activation of core domain was screened by using Dual-Luciferase Reporter Assay System. The Sertoli cells were harvested from 20-day-old Sprague-Dawley male rats and total RNA was isolated. The uPA mRNA levels and MyD88 pathway were tested by qPCR.

Results: We successfully cloned the 1517-bp rat uPA gene and screened the core domain (-455/+40) in five different fragments of uPA promoter. The uPA expression and uPA promoter activity were upregulated in lipopolysaccharide (LPS)-stimulated Sertoli cells. Furthermore, the uPA expression was regulated through the MyD88-independent pathway by interdicting IRF3 and interferon b.

Conclusion: uPA expression is likely induced by LPS through the core promoter domain of uPA. This finding implied that uPA played a role in the immune function of Sertoli cells in rat testis, which might provide the development of new treatments for male infertility.