EN
INTRODUCTION: Neuroinflammation is co-occurring phenomenon during pathological processes in the nervous system. Key player in this process is microglia. As sensing cells, microglia recognize any morbid changes and if needed, become activated. As moderate activation of microglia is beneficial, excessive one however, leads to more severe degeneration of tissue and inhibition of its endogenous regeneration. One way to prevent this situation is to modulate or inhibit microglia activation. AIM(S): Aim of this study was to use gene silencing technique to influence microglial activation. By targeting key proteins – NF‑κB, MyD‑88 and TRIF, we intended to decrease inflammatory signaling network. METHOD(S): To optimize gene silencing, we used stable murine microglia BV-2 cell line. To induce their activation, cells were exposed to lipopolysaccharide (LPS). After stimulation, cells were transfected with designed siRNA sequences targeting NF‑κB, MyD‑88 and TRIF. Efficacy of transfection was assessed by evaluating expression of NF‑κB, MyD‑88, TRIF as well as IL‑1β, IL‑6, TNF‑α at mRNA (qPCR) and protein level (Western blot). Optimized sequences of siRNA were then used on primary microglia isolated from adult mice in same scheme. RESULTS: Our results showed that siRNA can successfully inhibit activation of microglia in vitro after stimulation with LPS. Significant decrease was observed in expression of signaling proteins. However, depending on targeted factor, different decrease patterns were observed for IL‑1β, IL‑6 and TNF‑α. Thus, mixture of siRNA was combined to achieve most successful effect. Importantly, no or slight effect on microglia activation was observed due to siRNA transfection alone. CONCLUSIONS: Our results provide a new method to successfully limit microglia activation with siRNA technique. It may open new ways to modulate neuroinflammation and protect nervous system from severe degeneration. However, for effective use of such approach in vivo, optimization of delivery and stability of silencing molecules is needed.