Objective: Chronic nonbacterial prostatitis (CNP) has remained one of the most prevalent urological diseases, particularly in older men. Dihydroartemisinin (DHA) has been identified as a semi-synthetic derivative of artemisinin that exhibits broad protective effects. However, the role of DHA in inhibiting CNP inflammation and prostatic epithelial cell proliferation remains largely unknown.
Materials and Methods: CNP mice model was induced by carrageenan and Haemotoxylin Eosin (HE) ,immunofluorescence and immunochemistry staining were used to confirm CNP and E2F7 expression. Human prostatic epithelial cells (HPECs) and RWPE-1 was induced by lipopolysaccharide (LPS) to mimic CNP model in vitro. Real-time quantitative PCR and Western blot were used to detect proliferation and inflammatory genes expression. Cell proliferation was determined using MTT assay.
Results: DHA significantly alleviated the rough epithelium and inhibited multilamellar cell formation in the prostatic gland cavity and prostatic index induced by carrageenan. In addition, DHA decreased the expression of TNF-α and IL-6 inflammatory factors in prostatitis tissues and in LPS-induced epithelial cells. Upregulation of transcription factor E2F7, which expression was inhibited by DHA, was found in CNP tissues, human BPH tissues and LPS-induced epithelial cells inflammatory response. Mechanically, we found that depletion of E2F7 by shRNA inhibited epithelial cell proliferation and LPS-induced inflammation while DHA further enhance these effects. Furthermore, HIF1α was transcriptional regulated by E2F7 and involved in E2F7-inhibited CNP and cellular inflammatory response. Interestingly, we found that inhibition of HIF1α blocks E2F7-induced cell inflammatory response but does not obstruct E2F7-promoted cell growth.
Conclusion: The results revealed that DHA inhibits the CNP and inflammation by blocking the E2F7/HIF1α pathway. Our findings provide new evidence for the mechanism of DHA and its key role in CNP, which may provide an alternative solution for the prevention and treatment of CNP.