MicroRNA-146a and microRNA-146b expression and anti-inflammatory function in human airway smooth muscle
MicroRNA-146a and microRNA-146b expression and anti-inflammatory function in human airway smooth muscle
复制标题
DOI：
10.1152/ajplung.00174.2014
复制
发表时间：
2014-11-01
影响因子：
4.9
通讯作者：
Gerthoffer, William T.
中科院分区：
文献类型：
--
作者：
Comer, Brian S.;Camoretti-Mercado, Blanca;Gerthoffer, William T.
microRNA（miR）-146 a和miR-146 b是肺成纤维细胞、上皮细胞、单核细胞和内皮细胞中炎性基因表达的负调节因子。环氧化酶-2（考克斯-2）和IL-1 β的丰度受到miR-146家族的负调节，表明miR-146 a和/或miR-146 b可能调节气道平滑肌中的炎症介质表达，从而促进哮喘的发病。为了验证这一观点，我们比较了来自非哮喘和哮喘受试者的人气道平滑肌细胞（hASMCs）中miR-146 a和miR-146 b的表达，这些受试者接受了cytomix（IL-1 β、TNF-α和IFN γ）治疗，并检测了miRNAs对考克斯-2和IL-1 β表达的影响。我们发现cytomix处理提高了miR-146 a和miR-146 b的丰度。cytomix的诱导作用大于单个细胞因子的诱导作用，cytomix处理后哮喘细胞比非哮喘细胞表现出更高水平的miR-146 a表达。miR-146 a或miR-146 b模拟物的转染降低了考克斯-2和IL-1 β的表达。miR-146 a抑制剂增加了考克斯-2和IL-1 β的表达，但miR-146 b抑制剂无效。miR-146 a对考克斯-2和IL-1 β表达的抑制与RNA结合蛋白人抗原R丰度的降低相关。这些结果表明，hASMC中的miR-146 a和miR-146 b表达可被促炎细胞因子诱导，并且哮喘细胞中的miR-146 a表达更高。miR-146 a和miR-146 b均能在药理学水平上负调控考克斯-2和IL-1 β的表达，但功能丧失研究表明，只有miR-146 a是hASMCs的内源性负调控因子。结果表明，miR-146模拟物可能是进一步临床前研究的有吸引力的候选者，作为哮喘的抗炎治疗。
MicroRNA (miR)-146a and miR-146b are negative regulators of inflammatory gene expression in lung fibroblasts, epithelial cells, monocytes, and endothelial cells. The abundance of cyclooxygenase-2 (COX-2) and IL-1 beta is negatively regulated by the miR-146 family, suggesting miR-146a and/or miR-146b might modulate inflammatory mediator expression in airway smooth muscle thereby contributing to pathogenesis of asthma. To test this idea we compared miR-146a and miR-146b expression in human airway smooth muscle cells (hASMCs) from nonasthmatic and asthmatic subjects treated with cytomix (IL-1 beta, TNF-alpha, and IFN gamma) and examined the miRNAs' effects on COX-2 and IL-1 beta expression. We found that cytomix treatment elevated miR-146a and miR-146b abundance. Induction with cytomix was greater than induction with individual cytokines, and asthmatic cells exhibited higher levels of miR-146a expression following cytomix treatment than nonasthmatic cells. Transfection of miR-146a or miR-146b mimics reduced COX-2 and IL-1 beta expression. A miR-146a inhibitor increased COX-2 and IL-1 beta expression, but a miR-146b inhibitor was ineffective. Repression of COX-2 and IL-1 beta expression by miR-146a correlated with reduced abundance of the RNA-binding protein human antigen R. These results demonstrate that miR-146a and miR-146b expression is inducible in hASMCs by proinflammatory cytokines and that miR-146a expression is greater in asthmatic cells. Both miR-146a and miR-146b can negatively regulate COX-2 and IL-1 beta expression at pharmacological levels, but loss-of-function studies showed that only miR-146a is an endogenous negative regulator in hASMCs. The results suggest miR-146 mimics may be an attractive candidate for further preclinical studies as an anti-inflammatory treatment of asthma.