Department of Nephrology, Tainan Sinlau Hospital, Tainan, 701, Taiwan; Department of Health Care Administration, Chang Jung Christian University, Tainan, 711, Taiwan.
Department of Nephrology, Kaohsiung Medical University, Kaohsiung, 807, Taiwan.
Biomed Pharmacother. 2020 Apr;124:109892. doi: 10.1016/j.biopha.2020.109892. Epub 2020 Jan 24.
Macrophage migration inhibitory factor (MIF) is found to increase in proliferative glomerulonephritis. MIF binds to the MIF receptor (CD74) that activates MAP kinase (ERK and p38). Integrins and cyclinD1 regulate cell proliferation, differentiation and adhesion. This study evaluates whether MIF can regulate integrin-β1/cyclin D1 expression and cell adhesion of podocytes.
Expression of integrin-β1 mRNA/protein and cyclin D1 mRNA under stimulation of MIF was evaluated by real-time PCR and Western blotting. MIF receptor (CD74) and MAP kinase under MIF treatment were examined to determine which pathway regulated integrin-β1 and cyclin D1 expression. Cell adhesion was evaluated under MIF treatment and/or anti-integrin-β1 antibody by cell adhesion assay.
Protein levels of integrin-β1 were up-regulated under MIF treatment in a dosage-dependent manner. CD74 protein levels were not changed after MIF treatment. Integrin-β1 and cyclin D1 mRNA levels were up-regulated after MIF 100 ng/ml treatment. ERK inhibitor U0126 reduced MIF-induced the increase in integrin-β1 mRNA and protein expression following MIF stimulation. However, p38 inhibitor SB 203580 did not inhibit MIF-induced increase in integrin-β1 mRNA and protein expression following MIF stimulation. MIF-induced increase in cyclin D1 mRNA level also was inhibited only by U0126 following MIF stimulation. Podocyte adhesion was increased after MIF treatment, but, anti-integrin-β1 antibody decreased MIF-enhanced podocyte adhesion.
MIF increases integrin-β1 and cyclin D1 expression through the ERK pathway in podocytes, and the up-regulated expression of integrin-β1 increases podocyte adhesion. These results provide further understanding for the role of MIF in developing proliferative glomerulonephritis.
巨噬细胞移动抑制因子（MIF）在增生性肾小球肾炎中增加。MIF 与 MIF 受体（CD74）结合，激活 MAP 激酶（ERK 和 p38）。整合素和细胞周期蛋白 D1 调节细胞增殖、分化和黏附。本研究评估 MIF 是否可以调节足细胞的整合素-β1/细胞周期蛋白 D1 表达和细胞黏附。
通过实时 PCR 和 Western blot 评估 MIF 刺激下整合素-β1 mRNA/蛋白和细胞周期蛋白 D1 mRNA 的表达。检测 MIF 处理下的 MIF 受体（CD74）和 MAP 激酶，以确定哪种途径调节整合素-β1 和细胞周期蛋白 D1 的表达。通过细胞黏附试验评估 MIF 处理和/或抗整合素-β1 抗体下的细胞黏附。
MIF 以剂量依赖的方式上调整合素-β1 的蛋白水平。MIF 处理后 CD74 蛋白水平没有变化。MIF 100ng/ml 处理后，整合素-β1 和细胞周期蛋白 D1 mRNA 水平上调。ERK 抑制剂 U0126 减少了 MIF 刺激后整合素-β1 mRNA 和蛋白表达的增加。然而，p38 抑制剂 SB 203580 并没有抑制 MIF 刺激后整合素-β1 mRNA 和蛋白表达的增加。MIF 诱导的细胞周期蛋白 D1 mRNA 水平的增加也仅在 MIF 刺激后被 U0126 抑制。MIF 处理后足细胞黏附增加，但抗整合素-β1 抗体降低了 MIF 增强的足细胞黏附。
MIF 通过 ERK 途径增加足细胞中的整合素-β1 和细胞周期蛋白 D1 表达，上调的表达增加了足细胞的黏附。这些结果为 MIF 在增生性肾小球肾炎发病机制中的作用提供了进一步的理解。
