Study on expression of IL-6/JAK/STAT3 signaling pathway in category IIIB prostatitis

Objective: To investigate the expression levels of interleukin (IL)-6 and downstream JAK/STAT3 signaling pathway in category IIIB prostatitis. Methods: A total of 44 patients diagnosed with category IIIB prostatitis in our hospital were selected as study group. During the same period, forty healthy people underwent physical examination in our hospital were enrolled in control group. The differences of IL-6, IL-8 and IL-2 in serum and prostatic fluid in the two groups were compared. In addition, 80 Sprague-Dawley rats were randomly divided into four groups: control group (normal saline was injected every other day), prostatitis group (animal models of category IIIB prostatitis), prostatitis + IL-6 group (IL-6 was intraperitoneally injected to rats with prostatitis every other day for one month), prostatitis + blocker group (IL-6 downstream JAK2/STAT3 signaling pathway blocker AG490 was given to rats with prostatitis every other day for one month), with 20 rats in each group. The levels of IL-6, IL-8 and IL-2 in serum of the four groups of rats were detected. And the differences of expression levels of IL-6 and downstream signaling molecules (JAK and STAT3) in prostate tissues as well as the inflammatory degree of prostate pathological tissues of rats in the four groups were compared. Results: Compared with control group, the IL-6, IL-8 and IL-2 levels in prostatic fluid of patients in study group were obviously higher (all P<0.01), but the differences of those levels in serum were no significant (all P>0.05). The IL-6, IL-8 and IL-2 levels in serum of rats in the four groups had no significant difference (all P>0.05). However, in the prostate tissues of the four groups of rats, the numbers of IL-6 positive cells were ranked as prostatitis + IL-6 group > prostatitis group > control group > prostatitis + blocker group (all P<0.05), and the levels of JAK and STAT3 in the four groups were also with the same sequence (P<0.05), also, the inflammatory degrees were with the same trend. Conclusion: IL-6 and its downstream JAK/STAT3 signaling molecules present high expression in category IIIB prostatitis, and they may be involved in sterile inflammation.