AAV‐7F9‐Fc Protects Against METH‐Induced Hyperthermia and Decreases in Blood Brain Barrier Tight Junction Expression in a Rodent Model

Abstract

Methamphetamine (METH) is a potent psychostimulant, with no FDA‐approved pharmacological treatment options. METH can adversely affect brain homeostasis by initiating dysfunction in the Blood Brain Barrier (BBB) and hyperthermia. The BBB is a semipermeable barrier composed of endothelial cells and pericytes along blood capillaries. These cells are held together by tight junction (TJ) proteins (e.g., claudin‐5, occludin, etc) which limit paracellular transport and help regulate body temperature. METH can decrease the expression of these TJ proteins and induce hyperthermia leading to BBB dysfunction. Thus, a novel therapy that could mitigate these effects is needed.A novel treatment under evaluation in our laboratory is an anti‐METH single chain variable antibody‐fusion antibody (7F9‐Fc) packaged into adeno‐associated virus (AAV8) particles. AAV‐7F9‐Fc works as a pharmacokinetic antagonist to slow and reduce entry of METH into the brain. AAV‐7F9‐Fc has achieved long‐term serum concentrations in mice (>7 months from a single dose) and has been shown to alter locomotor effects of METH in mice. This treatment could have clinical potential to attenuate the effects of METH during drug use and aid addiction recovery.We hypothesized that an AAV delivered anti‐METH antibody fragment (AAV‐7F9‐Fc) will mitigate METH‐induced hyperthermia and BBB dysfunction. To begin to test this hypothesis, we recorded baseline temperatures of mice 1 h before administration of either saline or METH (10 mg/kg). Male BALB/c mice were randomized into one of five groups (n=5/group); 1) Saline + Saline, 2) Saline + METH, 3) AAV‐7F9‐Fc + Saline, 4) AAV‐7F9‐Fc + METH, 5) AAV‐empty vector + saline. After administration of either Saline or METH, rectal temperatures were probed for 1 h, and brains were collected at the 3 h time point. Brains were dissected on dry ice into key dopaminergic regions such as the Frontal Cortex and Hippocampus. After dissection, proteins were extracted via RIPA buffer and analyzed for their expression by Western Blot. In Saline+METH treated mice, a 40% decrease in expression of Claudin‐5 and a 45% decrease in expression of Occludin (p < 0.05) were observed in the Frontal Cortex. These results were mitigated in AAV‐7F9‐Fc + METH mice in the Frontal Cortex and Hippocampus. These results indicate two important findings in an acute setting. This indicates that AAV‐7F9‐Fc has the potential to mitigate in an acute administration of METH, 1). the ability of METH to induce Hyperthermia, and 2). cause a reduction of critical tight junction protein expression in the CNS.Support or Funding InformationThis research was funded by NIH/NIDA:R01‐DA036600 & R01 DA036600‐03S1, NIH/NIGMS:T32‐GM106999, and R25GM083297.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.