Guan Chang, Zhang Hai-Feng, Wang Ya-Jing, Chen Zhi-Teng, Deng Bing-Qing, Qiu Qiong, Chen Si-Xu, Wu Mao-Xiong, Chen Yang-Xin, Wang Jing-Feng
Department of Cardiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.
Laboratory of Cardiac Electrophysiology and Arrhythmia in Guangdong Province, Guangzhou, China.
Oxid Med Cell Longev. 2021 May 6;2021:5572088. doi: 10.1155/2021/5572088. eCollection 2021.
A disintegrin and metalloproteinase 17 (ADAM17) is a transmembrane protein that is widely expressed in various tissues; it mediates the shedding of many membrane-bound molecules, involving cell-cell and cell-matrix interactions. We investigated the role of ADAM17 within mouse cardiac fibroblasts (mCFs) in heart fibrosis.
mCFs were isolated from the hearts of neonatal mice. Effects of ADAM17 on the differentiation of mCFs towards myofibroblasts and their fibrotic behaviors following induction with TGF-1 were examined. The expression levels of fibrotic proteins, such as collagen I and -SMA, were assessed by qRT-PCR analysis and western blotting. Cell proliferation and migration were measured using the CCK-8 and wound healing assay. To identify the target gene for ADAM17, the protein levels of the components of endoplasmic reticulum (ER) stress and the PINK1/Parkin pathway were assessed following ADAM17 silencing. The effects of ADAM17 silencing or treatment with thapsigargin, a key stimulator of acute ER stress, on mCFs proliferation, migration, and collagen secretion were also examined. , we used a mouse model of cardiac fibrosis established by left anterior descending artery ligation; the mice were administered oral gavage with a selective ADAM17 inhibitor (TMI-005) for 4 weeks after the operation.
We found that the ADAM17 expression levels were higher in fibrosis heart tissues and TGF-1-treated mCFs. The ADAM17-specific siRNAs decreased TGF-1-induced increase in the collagen secretion, proliferation, and migration of mCFs. Knockdown of ADAM17 reduces the activation of mCFs by inhibiting the ATF6 branch of ER stress and further activating mitophagy. Moreover, decreased ADAM17 expression also ameliorated cardiac fibrosis and improved heart function.
This study highlights that mCF ADAM17 expression plays a key role in cardiac fibrosis by regulating ER stress and mitophagy, thereby limiting fibrosis and improving heart function. Therefore, ADAM17 downregulation, within the physiological range, could exert protective effects against cardiac fibrosis.
解聚素和金属蛋白酶17（ADAM17）是一种跨膜蛋白，在各种组织中广泛表达；它介导许多膜结合分子的脱落，涉及细胞间和细胞与基质的相互作用。我们研究了ADAM17在小鼠心脏成纤维细胞（mCFs）中在心脏纤维化中的作用。
从小鼠新生心脏中分离出mCFs。检测ADAM17对mCFs向肌成纤维细胞分化及其在转化生长因子-1（TGF-1）诱导后的纤维化行为的影响。通过qRT-PCR分析和蛋白质印迹法评估纤维化蛋白如I型胶原蛋白和α-平滑肌肌动蛋白（α-SMA）的表达水平。使用CCK-8和伤口愈合试验测量细胞增殖和迁移。为了鉴定ADAM17的靶基因，在ADAM17沉默后评估内质网（ER）应激成分和PINK1/ Parkin途径的蛋白质水平。还检测了ADAM17沉默或用毒胡萝卜素（一种急性ER应激的关键刺激剂）处理对mCFs增殖、迁移和胶原蛋白分泌的影响。此外，我们使用通过左前降支动脉结扎建立的心脏纤维化小鼠模型；术后给小鼠口服灌胃选择性ADAM17抑制剂（TMI-005）4周。
我们发现ADAM17在纤维化心脏组织和TGF-1处理的mCFs中的表达水平较高。ADAM17特异性小干扰RNA（siRNAs）降低了TGF-1诱导的mCFs胶原蛋白分泌、增殖和迁移的增加。ADAM17的敲低通过抑制ER应激的ATF6分支并进一步激活线粒体自噬来减少mCFs的活化。此外，ADAM17表达降低还改善了心脏纤维化并改善了心脏功能。
本研究强调mCF中ADAM17的表达通过调节ER应激和线粒体自噬在心脏纤维化中起关键作用，从而限制纤维化并改善心脏功能。因此，在生理范围内下调ADAM17可对心脏纤维化发挥保护作用。
