Sepsis-induced cardiac dysfunction remains one of the major causes of death in intensive care units. Overwhelmed inflammatory response and unrestrained cell death play critical roles in sepsis-induced cardiac dysfunction. Peroxisome proliferator-activated receptor- (PPAR-) γ has been proven to be cardioprotective in sepsis. However, the mechanism of PPAR-γ-mediated cardioprotection and its relationship with inflammation and cell death are unclear. We hypothesized that activation of PPAR-γ by reducing cardiac inflammation, myocardial apoptosis, and necroptosis may prevent myocardial dysfunction in sepsis. Rats were subjected to cecal ligation and puncture (CLP) with or without PPAR-γ agonist (rosiglitazone) or antagonist T0070907 (T007). After CLP, cardiac function was significantly depressed, which was associated with the destructed myocardium, upregulated proinflammatory cytokines, and increased apoptosis, necrosis, and necroptosis. This process is corresponded with decreased inhibitor κB (IκBα) and increased NF-κB, receptor-interacting protein kinase-1 (RIP1), RIP3, and mixed lineage kinase-like (MLKL) protein. Activation of PPAR-γ by rosiglitazone pretreatment enhanced PPAR-γ activity and prevented these changes, thereby improving the survival of septic rats. In contrast, inhibition of PPAR-γ by T007 further exacerbated the condition, dropping the survival rate to nearly 0%. In conclusion, PPAR-γ activation by reducing proinflammatory cytokines, apoptosis, and necroptosis in the myocardium prevents septic myocardial dysfunction.

Septic myocardial dysfunction remains prevalent and raises mortality rate in patients with sepsis. During sepsis, tissues undergo tremendous oxidative stress which contributes critically to organ dysfunction. Edaravone, a potent radical scavenger, has been proved beneficial in ischemic injuries involving hypoxia-inducible factor- (HIF-) 1, a key regulator of a prominent antioxidative protein heme oxygenase- (HO-) 1. However, its effect in septic myocardial dysfunction remains unclarified. We hypothesized that edaravone may prevent septic myocardial dysfunction by inducing the HIF-1/HO-1 pathway. Rats were subjected to cecal ligation and puncture (CLP) with or without edaravone infusion at three doses (50, 100, or 200 mg/kg, resp.) before CLP and intraperitoneal injection of the HIF-1α antagonist, ME (15 mg/kg), after CLP. After CLP, rats had cardiac dysfunction, which was associated with deformed myocardium, augmented lipid peroxidation, and increased myocardial apoptosis and inflammation, along with decreased activities of catalase, HIF-1α, and HO-1 in the myocardium. Edaravone pretreatment dose-dependently reversed the changes, of which high dose most effectively improved cardiac function and survival rate of septic rats. However, inhibition of HIF-1α by ME demolished the beneficial effects of edaravone at high dose, reducing the survival rate of the septic rats without treatments. Taken together, edaravone, by inducing the HIF-1α/HO-1 pathway, suppressed oxidative stress and protected the heart against septic myocardial injury and dysfunction.

Endothelial dysfunction induced by oxidative stress and inflammation plays a critical role in the pathogenesis of cardiovascular diseases. The anesthetic sevoflurane confers cytoprotective effects through its anti-inflammatory properties in various pathologies such as systemic inflammatory response syndrome and ischemic-reperfusion injury but mechanism is unclear. We hypothesized that sevoflurane can protect against tumor necrosis factor (TNF)-α-induced endothelial dysfunction through promoting the production of endothelium-dependent nitric oxide (NO). Primary cultured human umbilical vein endothelial cells (HUVECs) were pretreated with different concentrations (0.5, 1.5 and 2.5 minimum alveolar concentration, MAC) of sevoflurane for 30 min before TNF-α (10 ng/mL) stimulation for 4 h. Sevoflurane pretreatment significantly reduced TNF-α-induced VCAM-1, ICAM-1, IκBα, and NF-κB activation, and blocked leukocytes adhesion to HUVECs. Meanwhile, sevoflurane (1.5 and 2.5 MAC) significantly induced endothelial nitric oxide synthase (eNOS) phosphorylation and enhanced NO levels both intracellularly and in the cell culture medium. All these cytoprotective effects of sevoflurane were abrogated by NG-nitro-l-arginine methyl ester (l-NAME), a non-specific nitric oxide synthase inhibitor. Collectively, these data indicate that sevoflurane protects against TNF-α -induced vascular endothelium dysfunction through activation of eNOS/NO pathway and inhibition of NF-κB.