Department of Pharmaceutical Science, School of Pharmacy, Philadelphia College of Osteopathic Medicine, Suwanee, GA, USA.
Biochem Biophys Res Commun. 2018 Sep 18;503(4):2549-2554. doi: 10.1016/j.bbrc.2018.07.014. Epub 2018 Jul 13.
Long-term treatment with the potent immunosuppressive drug cyclosporine A (CsA) results in chronic nephrotoxicity. Its immunosuppressive properties are due to the inhibition of the calcium- and calmodulin-dependent phosphatase protein calcineurin A (CnA) which has three catalytic isoforms. Of those, the CnAα and β isoforms are ubiquitously expressed, particularly in the kidney. Additionally, chronic nephrotoxicity has been associated with an imbalance of extracellular matrix (ECM) synthesis and degradation resulting in an accumulation of ECM molecules. This study evaluates whether the expressions of matrix metalloproteinases (MMP-2 and MMP-9) induced by CsA are calcineurin isoform specific. Wild-type (WT), CnAα knockout (CnAα) and CnAβ knockout (CnAβ) kidney fibroblast cell lines (an in vitro innovative tool that was previously created in our lab) were treated with CsA at 10 ng/ml for 48 h. ELISA analysis demonstrated that the CsA-induced secretion profile of MMP-9 was highest in CnAα cells and lowest in CnAβ cells vs. WT cells. In contrast, CsA did not induce an increase in MMP-2 protein levels in WT, CnAα nor CnAβ renal fibroblasts. These results indicate that MMP-9 secretion is CnA-isoform specific, i.e. the CnAβ isoform contributes to the CsA-induced upregulation of MMP-9 while the CnAα does not. As such, understanding the role of calcineurin A isoforms in the regulation of the homeostasis of ECM degradation in the kidney after long-term CsA treatment needs to be further investigated.
长期使用强效免疫抑制剂环孢素 A（CsA）会导致慢性肾毒性。其免疫抑制特性归因于抑制钙和钙调蛋白依赖性磷酸酶蛋白钙调神经磷酸酶 A（CnA），CnA 有三个催化同工型。其中，CnAα 和 CnAβ 同工型广泛表达，特别是在肾脏中。此外，慢性肾毒性与细胞外基质（ECM）合成和降解的失衡有关，导致 ECM 分子的积累。本研究评估 CsA 诱导的基质金属蛋白酶（MMP-2 和 MMP-9）的表达是否与钙调神经磷酸酶同工型特异性相关。野生型（WT）、CnAα 敲除（CnAα）和 CnAβ 敲除（CnAβ）肾成纤维细胞系（这是我们实验室之前创建的体外创新工具）用 10ng/ml 的 CsA 处理 48 小时。ELISA 分析表明，CsA 诱导的 MMP-9 分泌谱在 CnAα 细胞中最高，在 CnAβ 细胞中最低，而在 WT 细胞中最低。相比之下，CsA 并未诱导 WT、CnAα 或 CnAβ 肾成纤维细胞中 MMP-2 蛋白水平的增加。这些结果表明，MMP-9 的分泌是钙调神经磷酸酶同工型特异性的，即 CnAβ 同工型有助于 CsA 诱导的 MMP-9 上调，而 CnAα 同工型则没有。因此，需要进一步研究钙调神经磷酸酶 A 同工型在长期 CsA 治疗后肾脏 ECM 降解平衡调节中的作用。
