Type 17 Immune Response Facilitates Progression of Inflammation and Correlates with Cognition in Stable Schizophrenia

Dysregulation of the type 17 immune pathway has already been considered in schizophrenia and we previously measured decreased sera values of interleukin (IL)-17 in early stages. We further explored the possible correlation of IL-17 systemic levels with proinflammatory cytokines and cognitive scores and additionally analyzed the percentage of IL-17 producing lymphocytes in peripheral blood of patients with stable schizophrenia. We included 27 patients diagnosed with schizophrenia (F20), after a three-month stable depot antipsychotic therapy (risperidone or paliperidone) and 18 healthy control subjects. Positive and Negative Syndrome Scale of Schizophrenia and the Montreal-Cognitive Assessment (MoCA) were conducted. Sera concentrations of IL-17, IL-6, tumor necrosis factor alpha (TNF-α) and soluble ST2 receptor (sST2) were measured. Flow cytometry and Natural Killer (NK) and T cell analyses were done in 10 patients and 10 healthy controls. Moderate positive correlation was established between IL-17 and TNF-α (r = 0.640; p = 0.001), IL-17 and IL-6 (r = 0.514; p = 0.006), IL-17 and sST2 (r = 0.394; p = 0.042). Furthermore, a positive correlation between the serum levels of IL-17 and MoCA scores was observed, especially with visuospatial and executive functioning, as well as language functioning and delayed recall (p < 0.05). Significantly higher percentage of IL-17 producing CD56⁺ NK cells was measured in peripheral blood of patients with schizophrenia in remission vs. healthy individuals (p = 0.001). The percentage of CD4⁺ T cells and CD4⁺ T cells that produce IL-17 was significantly increased in patients (p = 0.001). This study revealed the involvement of innate type 17 immune response in the progression of inflammation and this could be related to cognitive functioning in stable schizophrenia.

miR‑125b‑mediated regulation of cell proliferation through the Jagged‑1/Notch signaling pathway by inhibiting BRD4 expression in psoriasis

Psoriasis is a chronic inflammatory disease characterized by the abnormal differentiation and hyperproliferation of epidermal keratinocytes. The aim of the present study was to investigate the mechanism by which microRNA‑125b (miR‑125b) inhibits the activation of the bromodomain‑containing protein 4 (BRD4)/Notch signaling pathway in psoriasis. The contents of associated miRNAs in serum samples from 32 patients with psoriasis were detected by reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR). The most significantly downregulated miRNA, miR‑125b, was screened out. In experiments using HaCaT cells, the association between miR‑125b and cell proliferation was observed using a Cell Counting Kit‑8 assay, that between miR‑125b and the Notch signaling pathway was observed by western blotting and RT‑qPCR, and that between miR‑125b and the upstream molecule BRD4 of the Notch signaling pathway was observed by luciferase reporter assay and western blotting. The proliferation of HaCaT cells became apparent following miR‑125b inhibition. The Jagged‑1 ligand in the Notch signaling pathway was upregulated, the active intracellular domain of the Notch1 receptor was increasingly truncated, and the Notch signaling pathway was activated. Furthermore, the inhibited miR‑125b contributed directly toward the upstream protein BRD4 3'‑UTR of Jagged‑1, ultimately activating the Notch signaling pathway with the upregulation of Jagged‑1. In conclusion, the proliferation of HaCaT cells mediated by the Jagged‑1/Notch signaling pathway was decreased with the miR‑125b‑mediated inhibition of BRD4 expression. Therefore, miR‑125b may be a biomarker and potential therapeutic target for psoriasis treatment.