Autophagy activates EGR1 via MAPK/ERK to induce FGF2 in renal tubular cells for fibroblast activation and fibrosis during maladaptive kidney repair.
Autophagy activates EGR1 via MAPK/ERK to induce FGF2 in renal tubular cells for fibroblast activation and fibrosis during maladaptive kidney repair.
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DOI：
10.1080/15548627.2023.2281156
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发表时间：
2023-11
期刊：
影响因子：
13.3
通讯作者：
M. Livingston;Ming Zhang;Sangho Kwon;Jian-Kang Chen;Honglin Li;S. Manicassamy;Zheng Dong
中科院分区：
文献类型：
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作者：
M. Livingston;Ming Zhang;Sangho Kwon;Jian-Kang Chen;Honglin Li;S. Manicassamy;Zheng Dong
摘要巨细胞自噬/自噬通过诱导促纤维化因子如FGF 2（成纤维细胞生长因子2）导致适应不良的肾脏修复，但其潜在机制仍不清楚。在这里，我们表明，EGR 1（早期生长反应1）诱导缺血性急性肾损伤（阿基）后，在受损的近端小管，这种诱导被抑制诱导，肾小管特异性atg 7（自噬相关7）敲除（iRT-atg 7 KO）小鼠的自噬缺陷。在培养的近端肾小管细胞中，TGFB 1（转化生长因子β 1）诱导EGFR 1，这种诱导也是自噬依赖的。在TGF β 1处理过程中，肾小管细胞中的Egr 1敲低降低了FGF 2的表达，导致FGF 2分泌减少，并降低了对成纤维细胞的旁分泌作用。ChIP法检测到TGFB 1处理的肾小管细胞中EGFR 1与Fgf 2基因启动子的结合增加。Fgf 2和Egr 1的转录都被FGF 2中和抗体抑制，表明EGFR 1介导的FGF 2自身调节的正反馈。这种反馈在fgf 2缺陷型肾小管细胞和fgf 2缺陷型小鼠身上得到了证实。EGR 1上游，小鼠自噬缺陷抑制缺血后肾小管中MAPK/ERK（丝裂原活化蛋白激酶）的活化。这种抑制作用与SQSTM 1/p62（隔离体1）聚集及其对MAPK/ERK的隔离有关。SQSTM 1/p62与MAPK/ERK相互作用并在TGFB 1处理自噬缺陷的肾小管细胞期间阻断其活化。抑制MAPK/ERK可抑制适应不良肾小管中EGR 1和FGF 2的表达，从而改善肾纤维化和肾功能。这些结果表明，自噬激活肾小管细胞中的MAPK/ERK，从而诱导EGFR 1反式激活FGF 2。然后，FGF 2分泌到结缔组织中以刺激成纤维细胞进行纤维发生。简称：3-甲基丙烯酸：3-甲基腺嘌呤; ACTA 2/α-SMA：肌动蛋白α 2，平滑肌，主动脉; ACTB/β-肌动蛋白：肌动蛋白，β;阿基：急性肾损伤; aa：氨基酸; ATG/Atg：自噬相关; BUN：血尿素氮; ChIP：染色质免疫沉淀; CKD：慢性肾病; CM：条件培养基; COL 1A 1：胶原蛋白，I型，α 1; COL 4A 1：胶原蛋白，IV型，α 1; CQ：氯喹; DBA：双花扁豆凝集素; EGR1：早期生长反应1; ELK 1：ELK 1，ETS癌基因家族成员; FGF 2：成纤维细胞生长因子2; FN 1：纤连蛋白1; GAPDH：甘油醛-3-磷酸脱氢酶; HAVCR 1/KIM-1：甲型肝炎病毒细胞受体1; IP：免疫沉淀; LIR：LC 3相互作用区; MAP 1 LC 3B/LC 3B：微管相关蛋白1轻链3 β; MAP 2K/MEK：丝裂原活化蛋白激酶激酶; MAPK：丝裂原活化蛋白激酶; NF κ B：核因子κ B; PB 1：Phox和Bem 1; PFT：匹非林α; PPIB/亲环蛋白B：肽基脯氨酰异构酶B; RT-qPCR：真实的时间定量PCR; SQSTM 1/p62：多价螯合体1; TGF β 1/TGF-β1：转化生长因子β 1; Vim：波形蛋白
ABSTRACT Macroautophagy/autophagy contributes to maladaptive kidney repair by inducing pro-fibrotic factors such as FGF2 (fibroblast growth factor 2), but the underlying mechanism remains elusive. Here, we show that EGR1 (early growth response 1) was induced in injured proximal tubules after ischemic acute kidney injury (AKI) and this induction was suppressed by autophagy deficiency in inducible, renal tubule-specific atg7 (autophagy related 7) knockout (iRT-atg7 KO) mice. In cultured proximal tubular cells, TGFB1 (transforming growth factor beta 1) induced EGR1 and this induction was also autophagy dependent. Egr1 knockdown in tubular cells reduced FGF2 expression during TGFB1 treatment, leading to less FGF2 secretion and decreased paracrine effects on fibroblasts. ChIP assay detected an increased binding of EGR1 to the Fgf2 gene promoter in TGFB1-treated tubular cells. Both Fgf2 and Egr1 transcription was inhibited by FGF2 neutralizing antibody, suggesting a positive feedback for EGR1-mediated FGF2 autoregulation. This feedback was confirmed using fgf2-deficient tubular cells and fgf2-deficient mice. Upstream of EGR1, autophagy deficiency in mice suppressed MAPK/ERK (mitogen-activated protein kinase) activation in post-ischemic renal tubules. This inhibition correlated with SQSTM1/p62 (sequestosome 1) aggregation and its sequestration of MAPK/ERK. SQSTM1/p62 interacted with MAPK/ERK and blocked its activation during TGFB1 treatment in autophagy-deficient tubular cells. Inhibition of MAPK/ERK suppressed EGR1 and FGF2 expression in maladaptive tubules, leading to the amelioration of renal fibrosis and improvement of renal function. These results suggest that autophagy activates MAPK/ERK in renal tubular cells, which induces EGR1 to transactivate FGF2. FGF2 is then secreted into the interstitium to stimulate fibroblasts for fibrogenesis. Abbreviation: 3-MA: 3-methyladenine; ACTA2/α-SMA: actin alpha 2, smooth muscle, aorta; ACTB/β-actin: actin, beta; AKI: acute kidney injury; aa: amino acid; ATG/Atg: autophagy related; BUN: blood urea nitrogen; ChIP: chromatin immunoprecipitation; CKD: chronic kidney disease; CM: conditioned medium; COL1A1: collagen, type I, alpha 1; COL4A1: collagen, type IV, alpha 1; CQ: chloroquine; DBA: dolichos biflorus agglutinin; EGR1: early growth response 1; ELK1: ELK1, member of ETS oncogene family; FGF2: fibroblast growth factor 2; FN1: fibronectin 1; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; HAVCR1/KIM-1: hepatitis A virus cellular receptor 1; IP: immunoprecipitation; LIR: LC3-interacting region; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3 beta; MAP2K/MEK: mitogen-activated protein kinase kinase; MAPK: mitogen-activated protein kinase; NFKB: nuclear factor kappa B; PB1: Phox and Bem1; PFT: pifithrin α; PPIB/cyclophilin B: peptidylprolyl isomerase B; RT-qPCR: real time-quantitative PCR; SQSTM1/p62: sequestosome 1; TGFB1/TGF-β1: transforming growth factor beta 1; VIM: vimentin