Statins prevent cognitive impairment after sepsis by reverting neuroinflammation, and microcirculatory/endothelial dysfunction

Acute brain dysfunction is a frequent condition in sepsis patients and is associated with increased mortality and long-term neurocognitive consequences. Impaired memory and executive function are common findings in sepsis survivors. Although neuroinflammation and blood-brain barrier dysfunction have been associated with acute brain dysfunction and its consequences, no specific treatments are available that prevent cognitive impairment after sepsis. Experimental sepsis was induced in Swiss Webster mice by intraperitoneal injection of cecal material (5 mg/kg, 500 μL). Control groups (n = 5/group each experiment) received 500 μL of saline. Support therapy recover (saline 0.9%, 1 mL and imipenem 30 mg/kg) were applied (6, 24 and 48 h post injection, n = 5–10/group, each experiment), together or not with additive orally treatment with statins (atorvastatin/simvastatin 20 mg/kg b.w.). Survival rate was monitored at 6, 24 and 48 h. In a setting of experiments, animals were euthanized at 6 and 24 h after induction for biochemical, immunohistochemistry and intravital analysis. Statins did not prevented mortality in septic mice, however survivors presented lower clinical score. At another setting of experiments, after 15 days, mice survivors from fecal supernatant peritoneal sepsis presented cognitive dysfunction for contextual hippocampal and aversive amygdala-dependent memories, which was prevented by atorvastatin/simvastatin treatment. Systemic and brain tissue levels of proinflammatory cytokines/chemokines and activation of microglial were lower in septic mice treated with statins. Brain lipid peroxidation and myeloperoxidase levels were also reduced by statins treatment. Intravital examination of the brain vessels of septic animals revealed decreased functional capillary density and increased rolling and adhesion of leukocytes, and blood flow impairment, which were reversed by treatment with statins. In addition, treatment with statins restored the cholinergic vasodilator response due to sepsis. Taken together, these data demonstrated that statins reverse microvascular dysfunction and reduce neuroinflammation during sepsis, preventing the development of long-term cognitive decline.