Haidar Omar, O'Neill Nathanael, Staunton Caroline A, Bavan Selvan, O'Brien Fiona, Zouggari Sarah, Sharif Umar, Mobasheri Ali, Kumagai Kosuke, Barrett-Jolley Richard
Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom.
Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland.
Front Physiol. 2020 Mar 24;11:226. doi: 10.3389/fphys.2020.00226. eCollection 2020.
The synovium secretes synovial fluid, but is also richly innervated with nociceptors and acts as a gateway between avascular joint tissues and the circulatory system. Resident fibroblast-like synoviocytes' (FLS) calcium-activated potassium channels ( ) change in activity in arthritis models and this correlates with FLS .
To investigate this activation in an model of inflammatory arthritis; 72 h treatment with cytokines TNFα and IL1β.
FLS cells were isolated from rat synovial membranes. We analyzed global changes in FLS mRNA by RNA-sequencing, then focused on FLS ion channel genes and the corresponding FLS electrophysiological phenotype and finally modeling data with ingenuity pathway analysis (IPA) and MATLAB.
IPA showed significant activation of inflammatory, osteoarthritic and calcium signaling canonical pathways by cytokines, and we identified ∼200 channel gene transcripts. The large (BK) channel consists of the pore forming Kcnma1 together with β-subunits. Following cytokine treatment, a significant increase in Kcnma1 RNA abundance was detected by qPCR and changes in several ion channels were detected by RNA-sequencing, including a loss of BK channel β-subunit expression Kcnmb1/2 and an increase in Kcnmb3. In electrophysiological experiments, there was a decrease in over-all current density at 20 mV without change in chord conductance at this potential.
TNFα and IL1β treatment of FLS recapitulated several common features of inflammatory arthritis at the transcriptomic level, including increase in Kcnma1 and Kcnmb3 gene expression.
滑膜分泌滑液，但也富含伤害感受器，并作为无血管关节组织与循环系统之间的通道。驻留的成纤维细胞样滑膜细胞（FLS）的钙激活钾通道（ ）在关节炎模型中的活性发生变化，这与FLS 相关。
在炎性关节炎的 模型中研究这种激活；用细胞因子TNFα和IL1β处理72小时。
从大鼠滑膜中分离FLS细胞。我们通过RNA测序分析FLS mRNA的整体变化，然后聚焦于FLS离子通道基因和相应的FLS电生理表型，最后用 Ingenuity 通路分析（IPA）和MATLAB对数据进行建模。
IPA显示细胞因子对炎症、骨关节炎和钙信号经典通路有显著激活作用，我们鉴定出约200个通道基因转录本。大电导钙激活钾通道（BK）由形成孔道的Kcnma1和β亚基组成。细胞因子处理后，通过qPCR检测到Kcnma1 RNA丰度显著增加，通过RNA测序检测到几个离子通道发生变化，包括BK通道β亚基Kcnmb1/2表达缺失和Kcnmb3增加。在电生理实验中，20 mV时的总体电流密度降低，而该电位下的弦电导无变化。
TNFα和IL1β处理FLS在转录组水平上重现了炎性关节炎的几个共同特征，包括Kcnma1和Kcnmb3基因表达增加。
