Julius Bernstein Institute of Physiology, Martin Luther University Halle-Wittenberg, Halle, Germany.
Adv Exp Med Biol. 2018;1072:207-211. doi: 10.1007/978-3-319-91287-5_33.
Under pathological conditions like inflammation, ischemia or in solid tumors, parameters of the microenvironment like local oxygenation and extracellular pH show marked changes when compared to healthy tissue. The altered microenvironment affects cellular phenotype of omnipresent fibroblasts and immune cells. Recently, the impact of the microenvironment on the expression patterns of microRNAs, small non-coding RNAs that regulate gene expression on a post-transcriptional level, was discussed. Therefore, microRNAs might be the link between altered microenvironmental parameters and changes in cellular phenotype. In this study, the effect of hypoxia-induced extracellular acidosis (24 h pH 6.6) on microRNA expression in fibroblasts and macrophages was analyzed. MicroRNAs in rat fibroblasts (NRK-49F) were examined with the miScript miRNA PCR Array and changes in the expression validated by TaqMan qPCR. Subsequently, the identified microRNAs were analyzed in RAW 264.7 mouse macrophages. Nine out of 84 tested microRNAs were found to be acidosis-regulated in fibroblasts by miRNA PCR array, most of them up-regulated. Of those, the pH dependency could be validated by TaqMan qPCR for five of these nine microRNAs. When comparing these microRNAs in terms of their expression in macrophages, profound differences were observed. Thus, acidosis-induced alterations in the expression of microRNAs seem to be cell-type specific. Only the up-regulation of the miR-133b by low pH was seen in all normal cells, but not in tumor cells. As the identified microRNAs are involved in the regulation of proliferation, cell death and migration (amongst others), acidosis-induced changes in their expression might affect cellular behavior of fibroblasts and macrophages under pathological conditions. For instance the proto-oncogene c-Jun, which is a target of the miR-133b, was shown to be acidosis-regulated. Acidosis could regulate the biological behavior via miRNA-133b and c-Jun.
在炎症、缺血或实体肿瘤等病理条件下，与健康组织相比，微环境的参数（如局部氧合和细胞外 pH 值）会发生明显变化。改变的微环境会影响普遍存在的成纤维细胞和免疫细胞的细胞表型。最近，人们讨论了微环境对 microRNAs（一种在转录后水平调节基因表达的小非编码 RNA）表达模式的影响。因此，microRNAs 可能是改变的微环境参数与细胞表型变化之间的联系。在这项研究中，分析了缺氧诱导的细胞外酸中毒（24 小时 pH 值 6.6）对成纤维细胞和巨噬细胞中 microRNA 表达的影响。使用 miScript miRNA PCR 阵列检查大鼠成纤维细胞（NRK-49F）中的 microRNAs，并通过 TaqMan qPCR 验证表达变化。随后，在 RAW 264.7 小鼠巨噬细胞中分析了鉴定出的 microRNAs。在 miRNA PCR 阵列中，在成纤维细胞中发现 84 个测试 microRNAs 中有 9 个受到酸中毒调节，大多数呈上调表达。其中，这 9 个 microRNAs 中的 5 个通过 TaqMan qPCR 可以验证 pH 值依赖性。在比较这些 microRNAs 在巨噬细胞中的表达时，观察到明显的差异。因此，microRNAs 的表达受酸中毒诱导的改变似乎是细胞类型特异性的。只有 miR-133b 的低 pH 值诱导上调在所有正常细胞中可见，但在肿瘤细胞中不可见。由于鉴定出的 microRNAs 参与增殖、细胞死亡和迁移（等）的调节，其表达的酸中毒诱导变化可能会影响成纤维细胞和巨噬细胞在病理条件下的细胞行为。例如，原癌基因 c-Jun 是 miR-133b 的靶标，已被证明受酸中毒调节。酸中毒可以通过 microRNA-133b 和 c-Jun 来调节生物学行为。
