BACKGROUND: Methamphetamine (METH), a confirmed neurotoxic drug, has also reportedly caused several intestinal inflammatory injury cases. The NLRP3 (Nod-like receptor 3 protein) inflammasome can induce several inflammatory injuries by activating IL-1β and IL-18 when overexpressed. We designed experiments to determine whether METH can cause intestinal inflammatory injury via NLRP3 inflammasome overexpression.

MATERIAL AND METHODS: IEC-6 cells were classified as control, METH (0.5 mM), and METH (0.5 mM)+MCC950 (100 μM) groups. C57BL/6 mice were separated into control, NS, METH (5 mg/kg), and METH (5 mg/kg)+MCC950 (10 mg/kg) groups (n=10). We detected apoptosis, transepithelial electrical resistance (TEER), and proinflammatory factors (IL-6, INF-γ, TNF-α, and NF-κB) in the METH cell model. We also assessed proinflammatory factors (IL-6, INF-γ, TNF-α, and NF-κB) and observed intestinal tissues stained with hematoxylin and eosin (HE) in the METH animal model to explore intestinal inflammatory injury due to METH. After adding MCC950 (an NLRP3 inflammasome inhibitor), we additionally detected NLRP3 inflammasome components (NLRP3, Caspase-1, and ASC), IL-1β, and IL-18 to estimate the relationship of the NLRP3 inflammasome with intestinal inflammatory injury due to METH.

RESULTS: METH can lead apoptosis, increase proinflammatory factors (e.g., IL-6, INF-γ, TNF-α, and NF-κB), and decrease TEER in the METH cell model. In the METH animal model, METH can cause obvious injury and increase proinflammatory factors (e.g., IL-6, INF-γ, TNF-α, and NF-κB). All the intestinal inflammatory changes due to METH depended on overexpression of the NLRP3 inflammasome and could be ameliorated by MCC950, except for ASC and NF-κB.

CONCLUSIONS: METH, in addition to being a confirmed neurotoxic drug, can also cause severe intestinal inflammatory injury via NLRP3 inflammasome overexpression. NF-κB may be an activator of the NLRP3 inflammasome in METH intestinal inflammatory injury.

Keywords: Inflammasomes, Intestines, Methamphetamine, Carrier Proteins, Caspase 1, Intestinal Mucosa, NLR Family, Pyrin Domain-Containing 3 Protein, Transcription Factor RelA