Wang Pan-Pan, Bai Hao-Miao, He Si-Yu, Xia Zi-Qi, Liu Mei-Jie, An Jiong, Zhou Jia-Heng, Li Chen-Han, Zhang Wei, Zhang Xing, Wang Xin-Pei, Li Jia
College of Life Sciences, Northwest University, Xi'an 710069, China.
School of Aerospace Medicine, Air Force Medical University, Xi'an 710032, China.
Sheng Li Xue Bao. 2023 Apr 25;75(2):179-187.
The present study was aimed to investigate the role and mechanism of glutaminolysis of cardiac fibroblasts (CFs) in hypertension-induced myocardial fibrosis. C57BL/6J mice were administered with a chronic infusion of angiotensin II (Ang II, 1.6 mg/kg per d) with a micro-osmotic pump to induce myocardial fibrosis. Masson staining was used to evaluate myocardial fibrosis. The mice were intraperitoneally injected with BPTES (12.5 mg/kg), a glutaminase 1 (GLS1)-specific inhibitor, to inhibit glutaminolysis simultaneously. Immunohistochemistry and Western blot were used to detect protein expression levels of GLS1, Collagen I and Collagen III in cardiac tissue. Neonatal Sprague-Dawley (SD) rat CFs were treated with 4 mmol/L glutamine (Gln) or BPTES (5 μmol/L) with or without Ang II (0.4 μmol/L) stimulation. The CFs were also treated with 2 mmol/L α-ketoglutarate (α-KG) under the stimulation of Ang II and BPTES. Wound healing test and CCK-8 were used to detect CFs migration and proliferation respectively. RT-qPCR and Western blot were used to detect mRNA and protein expression levels of GLS1, Collagen I and Collagen III. The results showed that blood pressure, heart weight and myocardial fibrosis were increased in Ang II-treated mice, and GLS1 expression in cardiac tissue was also significantly up-regulated. Gln significantly promoted the proliferation, migration, mRNA and protein expression of GLS1, Collagen I and Collagen III in the CFs with or without Ang II stimulation, whereas BPTES significantly decreased the above indices in the CFs. α-KG supplementation reversed the inhibitory effect of BPTES on the CFs under Ang II stimulation. Furthermore, in vivo intraperitoneal injection of BPTES alleviated cardiac fibrosis of Ang II-treated mice. In conclusion, glutaminolysis plays an important role in the process of cardiac fibrosis induced by Ang II. Targeted inhibition of glutaminolysis may be a new strategy for the treatment of myocardial fibrosis.
本研究旨在探讨心脏成纤维细胞（CFs）谷氨酰胺分解在高血压诱导的心肌纤维化中的作用及机制。采用微量渗透泵对C57BL/6J小鼠进行慢性输注血管紧张素II（Ang II，1.6 mg/kg每日）以诱导心肌纤维化。采用Masson染色评估心肌纤维化。同时腹腔注射BPTES（12.5 mg/kg），一种谷氨酰胺酶1（GLS1）特异性抑制剂，以抑制谷氨酰胺分解。采用免疫组织化学和蛋白质印迹法检测心脏组织中GLS1、I型胶原蛋白和III型胶原蛋白的蛋白表达水平。对新生Sprague-Dawley（SD）大鼠CFs分别用4 mmol/L谷氨酰胺（Gln）或BPTES（5 μmol/L）处理，同时给予或不给予Ang II（0.4 μmol/L）刺激。在Ang II和BPTES刺激下，CFs还用2 mmol/Lα-酮戊二酸（α-KG）处理。分别采用伤口愈合试验和CCK-8检测CFs的迁移和增殖。采用RT-qPCR和蛋白质印迹法检测GLS1、I型胶原蛋白和III型胶原蛋白的mRNA和蛋白表达水平。结果显示，Ang II处理的小鼠血压、心脏重量和心肌纤维化增加，心脏组织中GLS1表达也显著上调。Gln显著促进了有或无Ang II刺激的CFs中GLS1、I型胶原蛋白和III型胶原蛋白的增殖、迁移、mRNA和蛋白表达，而BPTES显著降低了CFs中的上述指标。补充α-KG逆转了BPTES对Ang II刺激下CFs的抑制作用。此外，体内腹腔注射BPTES减轻了Ang II处理小鼠的心脏纤维化。总之，谷氨酰胺分解在Ang II诱导的心脏纤维化过程中起重要作用。靶向抑制谷氨酰胺分解可能是治疗心肌纤维化的新策略。
