Dehydrocorydaline Protects Against Sepsis-Induced Myocardial Injury Through Modulating the TRAF6/NF-κB Pathway

by Selleckchem | Oct 23 2023

We aim to investigate the effect and mechanism of dehydrocorydaline (Deh), an alkaloidal component isolated from Rhizoma corydalis, in the treatment of sepsis-mediated myocardial injury. Lipopolysaccharide (LPS) was taken to construct an in-vitro sepsis-myocardial injury models H9C2 cardiomyocytes. The in-vivo model of sepsis in C57BL/6 mice was induced by intraperitoneal injection of Escherichia coli (E. coli). The in-vitro and in-vivo models were treated with Deh in different concentrations, respectively. Hematoxylin-eosin (HE) staining, Masson staining, and immunohistochemistry (IHC) staining were taken to evaluate the histopathological changes of the heart. ELISA was applied to evaluate the levels of inflammatory factors, including IL-6, IL-1β, TNFα, IFNγ, and oxidized factors SOD, GSH-PX in the plasma or culture medium. Western blot was used to measure the expressions of Bax, Bcl2, Caspase3, iNOS, Nrf2, HO-1, TRAF6, NF-κB in heart tissues and cells. The viability of H9C2 cardiomyocytes was detected by the CCK8 method and BrdU assay. The ROS level in the H9C2 cardiomyocytes were determined using immunofluorescence. As a result, Deh treatment improved the survival of sepsis mice, reduced TUNEL-labeled apoptosis of cardiomyocytes. In vitro, Deh enhanced the viability of LPS-induced H9C2 cardiomyocytes and inhibited cell apoptosis. Additionally, Deh showed significant anti-inflammatory and anti-oxidative stress functions via decreasing IL-1β, IL-6, TNFα, and IFNγ levels, mitigating ROS level, up-regulating Nrf2/HO-1, SOD, and GSH-PX expressions dose-dependently. Mechanistically, Deh inhibited TRAF6 expression and the phosphorylation of NF-κB p65. The intervention with a specific inhibitor of TRAF6 (C25-140) or NF-κB inhibitor (BAY 11-7082) markedly repressed the protective effects mediated by Deh. In conclusion, Deh restrains sepsis-induced cardiomyocyte injury by inhibiting the TRAF6/NF-κB pathway.

Comments:

Your study aimed to investigate the effect and mechanism of dehydrocorydaline (Deh), an alkaloidal component isolated from Rhizoma corydalis, in the treatment of sepsis-mediated myocardial injury. To achieve this, you used both in vitro and in vivo models.

For the in vitro model, you used H9C2 cardiomyocytes and induced sepsis-mediated myocardial injury by treating the cells with lipopolysaccharide (LPS). Different concentrations of Deh were applied to the cells. To evaluate the histopathological changes of the heart, you performed hematoxylin-eosin (HE) staining, Masson staining, and immunohistochemistry (IHC) staining. The levels of inflammatory factors (IL-6, IL-1β, TNFα, IFNγ) and oxidized factors (SOD, GSH-PX) in the plasma or culture medium were measured using ELISA. The expressions of Bax, Bcl2, Caspase3, iNOS, Nrf2, HO-1, TRAF6, and NF-κB were analyzed using Western blot.

In the in vivo model, sepsis was induced in C57BL/6 mice by intraperitoneal injection of Escherichia coli (E. coli). Similar to the in vitro model, different concentrations of Deh were administered to the mice. Histopathological changes of the heart were evaluated through HE staining, Masson staining, and IHC staining. ELISA was used to assess the levels of inflammatory factors and oxidized factors. Western blot analysis was performed to measure the expressions of Bax, Bcl2, Caspase3, iNOS, Nrf2, HO-1, TRAF6, and NF-κB in heart tissues.

The results of your study showed that treatment with Deh improved the survival of sepsis mice and reduced apoptosis of cardiomyocytes, as observed through TUNEL labeling. In the in vitro model, Deh enhanced the viability of LPS-induced H9C2 cardiomyocytes and inhibited cell apoptosis. Additionally, Deh exhibited significant anti-inflammatory and anti-oxidative stress properties by decreasing the levels of IL-1β, IL-6, TNFα, and IFNγ, mitigating ROS levels, and up-regulating the expressions of Nrf2/HO-1, SOD, and GSH-PX in a dose-dependent manner. Mechanistically, Deh inhibited TRAF6 expression and the phosphorylation of NF-κB p65. The protective effects mediated by Deh were significantly attenuated when a specific inhibitor of TRAF6 (C25-140) or an NF-κB inhibitor (BAY 11-7082) was used, indicating that Deh's actions were mediated through the TRAF6/NF-κB pathway.

In conclusion, your findings suggest that Deh effectively attenuates sepsis-induced cardiomyocyte injury by inhibiting the TRAF6/NF-κB pathway. This study sheds light on the potential therapeutic application of Deh for the treatment of sepsis-mediated myocardial injury.