Amitriptyline Reduces Sepsis-Induced Brain Damage Through TrkA Signaling Pathway.

Sepsis can induce acute and chronic changes in the central nervous system termed sepsis-associated encephalopathy (SAE). Not only cognitive deficits but also anxiety, depression, and post-traumatic stress disorder are common in severe sepsis survivors. In this study, we demonstrated that amitriptyline, a classic tricyclic antidepressant, reduced sepsis-induced brain damage through the tropomyosin receptor kinase A (TrkA) signaling pathway. Amitriptyline ameliorated neuronal loss assessed by Nissl staining in a mouse cecal ligation and puncture (CLP)-induced sepsis model. Furthermore, amitriptyline reduced early gliosis assessed by immunofluorescence and late cognitive deficits assessed by the Morris water maze (MWM) test. Moreover, amitriptyline treatment attenuated oxidative stress indicated by less superoxide dismutase (SOD) and catalase (CAT) activity consumption and malondialdehyde (MDA) accumulation. Interestingly, those protective effects of amitriptyline could be abolished by GW441756, a TrkA signaling pathway inhibitor. Immunoblot directly showed that TrkA signaling pathway-associated proteins, such as Akt and GSK3ß, were involved in the neuroprotective effects of amitriptyline. Thus, amitriptyline appears to be an encouraging candidate to treat cognitive deficits and depression after severe sepsis.

Pentamidine protects mice from cecal ligation and puncture-induced brain damage via inhibiting S100B/RAGE/NF-κB.

The brain is one of the earliest organs to be influenced during sepsis. Sepsis-associated encephalopathy (SAE) is frequent, but seldomly recognized and has no testified pharmacological therapy. In this study, we demonstrated that pentamidine, an antiprotozoal drug, is a good candidate since it blocks S100B/RAGE/NF-κB signaling pathway. Pentamidine ameliorated cecal ligation and puncture (CLP)-induced brain damage assessed by crystal violet staining and hematoxylin and eosin (H&E) staining. Moreover, pentamidine reduced neuroinflammation in mouse hippocampi. Immunofluorescence and Western blot analysis also showed that pentamidine inhibited CLP-induced gliosis and S100B/RAGE/NF-κB pathway activation. Interestingly, it could also attenuate oxidative stress indicated by decreased protein levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), and attenuation of malondialdehyde (MDA) accumulation and superoxide dismutase (SOD) consumption. Thus the S100B/RAGE/NF-κB pathway may be crucial in the pathogenesis of SAE and may be a promising pharmacological target to prevent SAE.