Microglial activation plays a central role in poststroke inflammation and causes secondary neuronal damage; however, it also contributes in debris clearance and chronic recovery. Microglial pro- and antiinflammatory responses (or so-called M1-M2 phenotypes) coexist and antagonize each other throughout the disease progress. As a result of this balance, poststroke immune responses alter stroke outcomes. Our previous study found microglial expression of interferon regulatory factor 5 (IRF5) and IRF4 was related to pro- and antiinflammatory responses, respectively. In the present study, we genetically modified the IRF5 and IRF4 signaling to explore their roles in stroke. Both in vitro and in vivo assays were utilized; IRF5 or IRF4 small interfering RNA (siRNA), lentivirus, and conditional knockout (CKO) techniques were employed to modulate IRF5 or IRF4 expression in microglia. We used a transient middle cerebral artery occlusion model to induce stroke and examined both acute and chronic stroke outcomes. Poststroke inflammation was evaluated with flow cytometry, RT-PCR, MultiPlex, and immunofluorescence staining. An oscillating pattern of the IRF5-IRF4 regulatory axis function was revealed. Down-regulation of IRF5 signaling by siRNA or CKO resulted in increased IRF4 expression, enhanced M2 activation, quenched proinflammatory responses, and improved stroke outcomes, whereas down-regulation of IRF4 led to increased IRF5 expression, enhanced M1 activation, exacerbated proinflammatory responses, and worse functional recovery. Up-regulation of IRF4 or IRF5 by lentivirus induced similar results. We conclude that the IRF5-IRF4 regulatory axis is a key determinant in microglial activation. The IRF5-IRF4 regulatory axis is a potential therapeutic target for neuroinflammation and ischemic stroke.

The prevalence of AGA in Chinese men was lower than in caucasian men but was similar to that in Korean men; however, over the age of 60 years it was approaching that in caucasian men but was higher than that in Korean men. The most common type in Chinese men with AGA was type III vertex. Interestingly, the prevalence of AGA in Chinese women was lower than that in Korean women and caucasian women, and type I was the most common type (Ludwig classification).

There is mounting evidence that T helper (Th)17 cells and regulatory T cells (Treg) play parts in the pathogenesis of autoimmune disease. Hence, levels of these T-cell subsets in patients with alopecia areata (AA) merit investigation. Our goal was to assess Th17 and Treg levels in peripheral blood mononuclear cells (PBMC) and scalp lesions of patients with AA, correlating the findings with clinical characteristics. PBMC of 177 patients with AA (test group) and 42 healthy controls and scalp tissues of 33 patients and 15 healthy controls were collected. Levels of Th17 and Treg subsets were then determined via flow cytometry and immunohistochemical staining, correlating results in test subjects with clinical features of AA. Th17 levels were significantly higher in patients, whereas Treg levels were lower by comparison. Furthermore, Th17 levels in patients with disease of short duration or in the active phase were significantly higher, relative to their respective counterparts. Th17 levels also negatively correlated with disease duration. While Treg levels were higher in severe AA than in mild AA. Results of lesions were parallel to findings of PBMC. Our data indicates an imbalance in the immune state of patients with AA.