The link between mitochondrial complex I and brain-derived neurotrophic factor in SH-SY5Y cells--The potential of JNX1001 as a therapeutic agent

Abstract

Mitochondrial complex I, which is the first member of the electron transport chain responsible for producing ATP, can produce reactive oxygen species and oxidative stress when it becomes dysfunctional. Complex I dysfunction and oxidative stress are strongly implicated in bipolar disorder (BD), a debilitating psychiatric disease, as is decreased levels of brain derived neurotrophic factor (BDNF) found in patients with BD, which is related to complex I activity. JNX1001, a clinical trial ready brain penetrant sapogenin, increases BDNF levels in animal models. Hence, we aimed to examine if JNX1001 can prevent complex I dysfunction-induced alterations produced by rotenone treatment in human neuroblastoma cells (SH-SY5Y). Complex I dysfunction decreased cell viability and increased protein carbonylation and nitration, confirming previous findings. Complex I dysfunction also decreased intracellular and extracellular BDNF levels. JNX1001 pre-treatment prevented complex I dysfunction-induced protein carbonylation and nitration and improved cell viability at concentrations of 30 nM and 300 nM, but more robustly at 300 nM. JNX1001 was also able to prevent decreased intracellular and extracellular BDNF levels, where it produced a ten-fold increase in intracellular BDNF levels at a concentration of 300 nM. While further studies are required to examine the neuroprotective ability of JNX1001 against alterations produced by complex I defect in more complex systems, such as in animal models, the findings of this study demonstrate the potential of JNX1001 to be used as a therapeutic agent to protect against complex I dysfunction-induced alterations that may be highly relevant to BD.

Keywords: BDNF; Carbonylation; JNX1001; Mitochondrial complex I; Nitration; Oxidative stress.