Calpain and caspase proteolytic markers co-localize with rat cortical neurons after exposure to methamphetamine and MDMA.
Matthew W Warren, Stephen F Larner, Firas H Kobeissy, Christina A Brezing, Jennifer A. Jeung, Ronald L Hayes, Mark S. Gold, Kevin K W Wang
Acta neuropathologica September 2007 DOI: 10.1007/s00401-007-0259-9 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cohort Peer reviewed |
|---|---|
| Population | Rat brain tissues |
| Duration | 24 and 48 hours after drug exposure |
| Topics | MDMA |
| Key findings | Activated calpain-1 and caspase-3 were localized to cortical neurons, with cleaved products concentrated in axonal regions, supporting the hypothesis that these enzymes mediate programmed cell death in cortical neurons following Meth and MDMA exposure. |
Abstract
Abuse of the club drugs Methamphetamine (Meth) and Ecstasy (MDMA) is an international problem. The seriousness of this problem is the result of what appears to be programmed cell death (PCD) occurring within the brain following their use. This follow up study focused on determining which cell types, neurons and/or glial cells, were affected in the brains of drug-injected rats. Two proteolytic enzyme families involved in PCD, calpains and caspases, were previously shown to be activated and to degrade the brain cytoskeletal associated protein alphaII-spectrin. Using methods employed and confirmed in traumatic brain injury (TBI) studies, rat brain tissues were examined, 24 and 48 h after Meth and MDMA exposure, for the activation of calpain-1 and caspase-3, and their subsequent alphaII-spectrin cleavage breakdown products (SBDPs), SBDP145, and SBDP120, respectively. Based upon our previous studies we know that activated calpain-1 and caspase-3 were up-regulated after drug use as were the levels of their cleaved SBDPs, SBDP145, and SBDP120, respectively, which is indicative of PCD. Here we show that activated calpain-1 and caspase-3 increases could be localized to neurons in the cortex where the products of their cleaved targets were found to be concentrated, particularly, to the axonal regions. These findings support the hypothesis that calpains and caspases mediate PCD in cortical neurons following club drug abuse and, more importantly, appear to contribute to the neuropathology suffered by abusers.