Objective: To explore the central sensitization mechanism of pain in chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS).
Methods: We randomly divided 40 adult male SPF SD rats, aged 3－4 weeks and weighing 250－350 g, into a normal control and a CP/CPPS model group. After modeling, we analyzed the state of infiltration of CD4+T cells into the L5－S2 spinal cord and detected the expression levels of GFAP and CR3 in the spinal cord tissue using flow cytometry, real-time fluorescent quantitative PCR (RT-qPCR) and immunofluorescence staining.
Results: Compared with the normal controls, the CP/CPPS model rats showed dramatically increased expression of CD4+T cells in the mononuclear cells of the L5－S2 spinal cord tissue (P < 0.01), mRNA expressions of interferon-γ (IFN-γ) and tumor necrosis factor α (TNF-α) secreted from the Th1 cells, interleukin (IL)-17 and retinoic acid-associated orphan receptor (ROR) γt secreted from the Th17 cells, cytokines IL-6 and IL-1β, and chemokines CCL2, CCL20 and CXCL10 (P < 0.01), and expressions of the molecular markers of Th1 and Th17 cells IFN-γ and IL-17 and those of astrocytes and microglias GFAP and CR3.
Conclusions: CD4+T cells, specifically Th1 and Th17 cells, infiltrate L5－S2 spinal cord neurons in CP/CPPS model rats. The inflammatory factors secreted from these cells may damage the neuronal cells, affect nervous conduction, promote central sensitization and activate astrocytes and microglias, leading to the development and progression of pain.
Keywords: CD4+T cell; central sensitization; glial cells; rat; chronic prostatitis/chronic pelvic pain syndrome.