Inhibition of glutaminolysis alleviates myocardial fibrosis induced by angiotensin II / 生理学报

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.

Effect of qubi recipe on changes of oxygen free radical metabolism and hypoxia-inducible factor-1alpha in collagen-induced arthritis rats / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To observe the effect of Qubi Recipe (QR) on the expression of superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase (GSH-Px), and hypoxia-inducible factor (HIF)-1alpha in rats with type II collagen-I induced arthritis (CIA), and to explore its therapeutic roles and mechanism.</p><p><b>METHODS</b>Totally 72 male SD rats of SPF grade were recruited. Twelve were randomly selected as the blank control group. The CIA model was established in the rest 60 rats by subcutaneously injecting type II collagen of bovine emulsion from the tail root and induction of incomplete Freund's adjuvant. On day 15 after primary immunization rats were randomly divided into four groups, i.e., the CIA model group, the Tripterygium Glycosides (TG) group (at the daily dose of 9.68 mg/kg body weight), the high dose QR group (at the daily dose of 6.66 g/kg body weight), and the low dose QR group (at the daily dose of 3.33 g/kg body weight), 15 in each group. Corresponding medication was given to rats in all groups by gastrogavage once daily for 4 successive weeks. An equal volume of pure water was given to rats in the blank control group and the CIA model group by gastrogavage, once daily for 4 successive weeks. The swelling degree of the joints was measured. Rats were sacrificed after 4-week treatment. Plasma levels of SOD, MDA, and GSH-Px were measured with colorimetric method. The expression of HIF-1alpha was detected by immunohistochemistry.</p><p><b>RESULTS</b>(1) Compared with the CIA model group, the swelling degree of the joints was significantly alleviated in the TG group and the high dose QR group (P < 0.01, P < 0.05), and it was obviously milder in the high dose QR group than in the TG group (P < 0.05). (2) Compared with the CIA model group, the activities of GSH-Px could be obviously elevated and activities of MDA lowered in the TG group, the high dose QR group, and the low dose QR group (P < 0.05). Plasma activities of SOD could be obviously elevated in the high dose QR group and the TG group (P < 0.05). (3) Compared with the CIA model group, the expression of HIF-1alpha obviously decreased in the TG group and the high dose QR group (P < 0.05), and it showed a decreasing tendency in the low dose QR group with no statistical difference (P > 0.05).</p><p><b>CONCLUSIONS</b>QR could markedly alleviate the swelling degree of ankle joints in CIA model rats. Its therapeutic efficacy was superior to that of TG. Its mechanism might be achieved through down-regulating expression of HIF-1alpha in the joint, and regulating activities of SOD, MDA and GSH-Px in the plasma.</p>