Shi Chunlai, Li Xuan, Hong Fei, Wang Xueyan, Jiang Tingting, Sun Bingbing, Li Shuang
Cardiovascular Department, Jinqiu Hospital of Liaoning Province, Shenyang, Liaoning 110016, P.R. China.
Exp Ther Med. 2021 Oct;22(4):1146. doi: 10.3892/etm.2021.10580. Epub 2021 Aug 9.
Cardiac fibrosis is a core process in the development of heart failure. However, the underlying mechanism of cardiac fibrosis remains unclear. Recently, a study found that in an isoproterenol (ISO)-induced cardiac fibrosis animal model, there is high expression of latent-transforming growth factor β-binding protein 2 (LTBP2) in cardiac fibroblasts. Whether LTBP2 serves a role in cardiac fibrosis is currently unknown. In the present study, mouse cardiac fibroblasts (MCFs) were treated with 100 µM/l ISO for 24, 48, or 72 h, and small interfering RNAs (siRNAs) were used to knockdown LTBP2. Reverse transcription-quantitative PCR and western blotting were used to determine gene and protein expression levels, respectively. Caspase-3 serves a key role in cell apoptosis and is related to cardiac fibrosis-induced heart failure. Caspase-3 activity was therefore determined using a caspase-3 assay kit, CCK8 was used to determine the rate of cell proliferation and apoptosis rates were quantified using a cell death detection ELISA kit. The present study demonstrated that cell apoptosis and LTBP2 expression increased in MCFs treated with 100 µM/l ISO in a time-dependent manner. Expression and activity of caspase-3 also increased in MCFs treated with 100 µM/l ISO for 48 h compared with the control group. In addition, ISO stimulation-induced MCF apoptosis, along with the increased expression of caspase-3 were partly abolished when LTBP2 was knocked down. In conclusion, LTBP2 expression increased in ISO-treated MCFs and accelerated mouse cardiac fibroblast apoptosis by enhancing the expression and activity of caspase-3. LTBP2 may therefore be a potential therapeutic target for treating patients with cardiac fibrosis.
心脏纤维化是心力衰竭发展过程中的核心环节。然而，心脏纤维化的潜在机制仍不清楚。最近，一项研究发现，在异丙肾上腺素（ISO）诱导的心脏纤维化动物模型中，心脏成纤维细胞中潜伏转化生长因子β结合蛋白2（LTBP2）表达上调。目前尚不清楚LTBP2是否在心脏纤维化中发挥作用。在本研究中，将小鼠心脏成纤维细胞（MCF）用100 μM/l ISO处理24、48或72小时，并用小干扰RNA（siRNA）敲低LTBP2。分别采用逆转录定量PCR和蛋白质印迹法检测基因和蛋白表达水平。半胱天冬酶-3在细胞凋亡中起关键作用，与心脏纤维化诱导的心力衰竭有关。因此，使用半胱天冬酶-3检测试剂盒测定半胱天冬酶-3活性，使用CCK8检测细胞增殖率，使用细胞死亡检测ELISA试剂盒定量细胞凋亡率。本研究表明，100 μM/l ISO处理的MCF中细胞凋亡和LTBP2表达呈时间依赖性增加。与对照组相比，100 μM/l ISO处理48小时的MCF中半胱天冬酶-3的表达和活性也增加。此外，敲低LTBP2后，ISO刺激诱导的MCF凋亡以及半胱天冬酶-3表达的增加部分被消除。总之，ISO处理的MCF中LTBP2表达增加，并通过增强半胱天冬酶-3的表达和活性加速小鼠心脏成纤维细胞凋亡。因此，LTBP2可能是治疗心脏纤维化患者的潜在治疗靶点。
