Selective Aryl Hydrocarbon Receptor Modulator 3,3'-Diindolylmethane Impairs AhR and ARNT Signaling and Protects Mouse Neuronal Cells Against Hypoxia.

Abstract

The neuroprotective potential of 3,3'-diindolylmethane (DIM), which is a selective aryl hydrocarbon receptor modulator, has recently been shown in cellular and animal models of Parkinson's disease and lipopolysaccharide-induced inflammation. However, there are no data concerning the protective capacity and mechanisms of DIM action in neuronal cells exposed to hypoxia. The aim of the present study was to investigate the neuroprotective potential of DIM against the hypoxia-induced damage in mouse hippocampal cells in primary cultures, with a particular focus on DIM interactions with the aryl hydrocarbon receptor (AhR), its nuclear translocator ARNT, and estrogen receptor β (ERβ). In the present study, 18 h of hypoxia induced apoptotic processes, in terms of the mitochondrial membrane potential, activation of caspase-3, and fragmentation of cell nuclei. These effects were accompanied by substantial lactate dehydrogenase release and neuronal cell death. The results of the present study demonstrated strong neuroprotective and anti-apoptotic actions of DIM in hippocampal cells exposed to hypoxia. In addition, DIM decreased the Ahr and Arnt mRNA expression and stimulated Erβ mRNA expression level. DIM-induced mRNA alterations were mirrored by changes in protein levels, except for ERβ, as detected by ELISA, Western blotting, and immunofluorescence labeling. We also demonstrated that DIM decreased the expression of AhR-regulated CYP1A1. Using specific siRNAs, we provided evidence that impairment of AhR and ARNT, but not ERβ plays a key role in the neuroprotective action of DIM against hypoxia-induced cell damage. This study may have implication for identifying new agents that could protect neurons against hypoxia by targeting AhR/ARNT signaling.

• Authors: J Rzemieniec, E Litwa, A Wnuk, W Lason, W Krzeptowski, M Kajta
• Journal: Molecular neurobiology (Mol Neurobiol) Vol. 53 Issue 8 Pg. 5591-606 (10 2016) ISSN: 1559-1182 [Electronic] United States
• PMID: 26476840 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Arnt protein, mouse
• Estrogen Receptor beta
• Indoles
• Microtubule-Associated Proteins
• Mtap2 protein, mouse
• RNA, Messenger
• RNA, Small Interfering
• Reactive Oxygen Species
• Receptors, Aryl Hydrocarbon
• Aryl Hydrocarbon Receptor Nuclear Translocator
• L-Lactate Dehydrogenase
• Cytochrome P-450 CYP1A1
• Caspase 3
• 3,3'-diindolylmethane

Topics

• Animals
• Apoptosis (drug effects)
• Aryl Hydrocarbon Receptor Nuclear Translocator (genetics, metabolism)
• Caspase 3 (metabolism)
• Cell Hypoxia (drug effects)
• Cell Survival (drug effects)
• Cells, Cultured
• Cytochrome P-450 CYP1A1 (metabolism)
• Enzyme Activation (drug effects)
• Estrogen Receptor beta (agonists, antagonists & inhibitors, metabolism)
• Gene Silencing (drug effects)
• Hippocampus (metabolism)
• Indoles (pharmacology)
• L-Lactate Dehydrogenase (metabolism)
• Membrane Potential, Mitochondrial (drug effects)
• Mice
• Microtubule-Associated Proteins (metabolism)
• Neurons (cytology, metabolism)
• Neuroprotection (drug effects)
• RNA, Messenger (genetics, metabolism)
• RNA, Small Interfering (metabolism)
• Reactive Oxygen Species (metabolism)
• Receptors, Aryl Hydrocarbon (genetics, metabolism)
• Signal Transduction (drug effects)
• Staining and Labeling