Effect of Calpain inhibitor I on glucocorticoid receptor-dependent degradation and its transactivation ability

Objective: To investigate the effect of Calpain inhibitor I on glucocorticoid receptor-dependent proteasomal degradation and its transcriptional activity. Methods: After Raw-264.7 cells were treated with Calpain inhibitor I, dexamethasone, or both for about 12 h, the change of glucocorticoid receptor was detected by western blot analysis. COS-7 cells were transfected with PRsh-GRα expression vector and glucocorticoid-responsive receptor pMAMneo-CAT, then the effect of Calpain inhibitor I on glucocorticoid receptor transcriptional activation ability was determined by CAT activity. Results: The glucocorticoid receptor levels decreased after RAW-264.7 cells were treated with dexamethasone for 12 hours, which effect can be inhibited by Calpain inhibitor I to some extent. CAT activity assay showed that Calpain inhibitor I enhance glucocorticoid receptor transcriptional activity. Conclusion: Calpain inhibitor I can inhibit the down-regulation of dexamethasone on glucocorticoid receptor, and enhances glucocorticoid receptor transactivation ability.

In Silico Evaluation of the Potential Interference of Boceprevir, Calpain Inhibitor II, Calpain Inhibitor XII, and GC376 in the Binding of SARS-CoV-2 Spike Protein to Human Nanobody Nb20

Virtual screening can be a helpful approach to propose treatments for COVID-19 by developing inhibitors for blocking the attachment of the virus to human cells. This study uses molecular docking, recovery time and dynamics to analyze if potential inhibitors of main protease (Mpro) of SARS-CoV-2 can interfere in the attachment of nanobodies, specifically Nb20, in the receptor binding domain (RBD) of SARS-CoV-2. The potential inhibitors are four compounds previously identified in a fluorescence resonance energy transfer (FRET)-based enzymatic assay for the SARS-CoV-2 Mpro: Boceprevir, Calpain Inhibitor II, Calpain Inhibitor XII, and GC376. The findings reveal that Boceprevir has the higher affinity with the RBD/Nb20 complex, followed by Calpain Inhibitor XII, GC376 and Calpain Inhibitor II. The recovery time indicates that the RBD/Nb20 complex needs a relatively short time to return to what it was before the presence of the ligands. For the RMSD the Boceprevir and Calpain Inhibitor II have the shortest interaction times, while Calpain Inhibitor XII shows slightly more interaction, but with significant pose fluctuations. On the other hand, GC376 remains stably bound for a longer duration compared to the other compounds, suggesting that they can potentially interfere with the neutralization process of Nb20.

Calpain inhIbitorⅠ对烧伤小鼠肝脏NF-κB转录及炎性细胞因子分泌的影响

探讨Calpain inhibitor I(CI-I)对严重烧伤小鼠肝脏IκBa表达,NF-κB转录及炎性细胞因子分泌的影响。将CI-Ⅰ腹腔给药预处理小鼠1 h后背部行20%全身体表面积(TBSA)Ⅲ度烧伤,收集肝组织,检测其IκBa表达,NF-κB转录和血清TNF-a、IL-1B、IL-6分泌水平。与烧伤对照组比较,CI-Ⅰ预处理后肝脏NF-κB转录活性和炎性细胞因子分泌有所降低。提示CI-Ⅰ预处理可有效抑制严重烧伤小鼠肝细胞NF-κB活化和血清炎性细胞因子分泌,从而有利于烧伤后的炎症调节。

需钙蛋白酶抑制剂I对LPS攻击的RAW264.7细胞中iκBα表达和细胞因子分泌的影响

目的:探讨需钙蛋白酶抑制剂I(CI-I)对LPS攻击RAW264.7细胞后iκBα表达和细胞因子分泌的影响。方法:用CI-I预处理RAW264.7细胞1h后,再用LPS攻击,分别用Westernblot和ELISA检测RAW264.7细胞iκBα蛋白表达和TNF-α、IL-6的分泌。结果:CI-I预处理RAW264.7细胞后,可抑制LPS导致的iκBα表达降低。LPS攻击RAW264.7细胞后4h和8h,TNF-α和IL-6的分泌均增加,CI-I和地塞米松(DEX)可抑制该效应,并具有协同抑制作用。结论:CI-I和DEX可抑制LPS攻击后RAW264.7细胞中iκBα表达和炎性细胞因子分泌,从而有助于减轻细胞损伤。