Cannabidiol Protects Dopaminergic-like Neurons against Paraquat- and Maneb-Induced Cell Death through Safeguarding DJ-1CYS¹⁰⁶ and Caspase 3 Independently of Cannabinoid Receptors: Relevance in Parkinson’s Disease

Abstract

Parkinson's disease (PD), a progressive neurodegenerative movement disorder, has reached pandemic status worldwide. This neurologic disorder is caused primarily by the specific deterioration of dopaminergic (DAergic) neurons in the substantia nigra pars compacta (SNc). Unfortunately, there are no therapeutic agents that slow or delay the disease progression. Herein, menstrual stromal cell-derived dopamine-like neurons (DALNs) intoxicated with paraquat (PQ 2+ )/maneb (MB) were used as a model system to elucidate the mechanism by which CBD protects the neural cell from apoptosis in vitro. According to immunofluorescence microscopy, flow cytometry, cell-free assay, and molecular docking analysis, we demonstrate that CBD offers protection to DALNs against PQ 2+ (1 mM)/ MB (50 μM)-induced oxidative stress (OS) by simultaneously (i) decreasing reactive oxygen species (ROS: O 2•− , H 2 O 2 ), (ii) maintaining the mitochondrial membrane potential (ΔΨ m ), (iii) directly binding to stress sensor protein DJ-1, thereby blunting its oxidation from DJ-1CYS 106 -SH into DJ-1CYS 106 -SO 3 , and (iv) directly binding to pro-apoptotic protease protein caspase 3 (CASP3), thereby disengaging neuronal dismantling. Furthermore, the protective effect of CBD on DJ-1 and CASP3 was independent of CB1 and CB2 receptor signaling. CBD also re-established the Ca 2+ influx in DALNs as a response to dopamine (DA) stimuli under PQ 2+ /MB exposure. Because of its powerful antioxidant and antiapoptotic effects, CBD offers potential therapeutic utility in the treatment of PD.

Isobolographic Analysis of the Cytoprotective Effect of Dapsone and Cannabidiol Alone or Combination upon Oxygen–Glucose Deprivation/Reoxygenation Model in SH-SY5Y Cells

“…Our findings demonstrated that caspase-3 activity decreased in SH-SY5Y cells under OGD/R conditions treated with DDS-CBD, showing a decrease in apoptosis. This event is consistent with current findings where reduced or null expression of caspase-9 and caspase-3 as observed in an in vitro model of cerebral ischemia, Alzheimer's [50,58,59], as well as cells treated with hydrogen peroxide [60], after exposure to CBD. On the other hand, it has also been observed that DDS is an antiapoptotic drug, as revealed in previous studies in which the administration of DDS decreased the activities of caspase-9 and caspase-3 in models of focal cerebral ischemia [29] and spinal cord injury in rats [61].…”

“…All of these actions explain DDS-CBD's potential neuroprotective effectiveness in the OGD/R model, as seen in Figure 7. 9 and caspase-3 as observed in an in vitro model of cerebral ischemia, Alzheimer's [50,58,59], as well as cells treated with hydrogen peroxide [60], after exposure to CBD. On the other hand, it has also been observed that DDS is an antiapoptotic drug, as revealed in previous studies in which the administration of DDS decreased the activities of caspase-9 and caspase-3 in models of focal cerebral ischemia [29] and spinal cord injury in rats [61].…”

Mechanisms Mediating the Combined Toxicity of Paraquat and Maneb in SH-SY5Y Neuroblastoma Cells

“…On the other hand, combined exposure to PQ + MB for 12 h decreased the MMP. Our findings align with previous studies indicating that the combination of PQ and MB reduces the MMP in dopamine-like neurons and in human nerve-like cells. , The MMP has an essential role in maintaining cellular homeostasis, and a drop of MMP may induce loss of cell viability and apoptosis . The toxicity of several xenobiotic compounds can have either a primary or a secondary effect on mitochondrial function.…”

“…Of note, it has been reported that MB potentiate PQ toxicity in in vivo and in vitro experimental conditions . Exposure to PQ plus MB in combination causes disruption of mitochondrial membrane potential (MMP) and induced oxidative stress in dopaminergic-like neurons . Moreover, exposure to PQ plus MB induces ferroptosis in SH-SY5Y cells, which was linked to NADPH oxidase activation …”

Protective Effects of Cannabidiol (CBD) against Qxidative Stress, but Not Excitotoxic-Related Neuronal Cell Damage—An In Vitro Study

“…Our data obtained in SH-SY5Y cells support reports showing the neuroprotective effects of CBD in other in vitro models of Parkinson's disease. Thus, CBD protected the neural cells from apoptosis in vitro menstrual stromal cell-derived dopamine-like neurons (DALNs) exposed to paraquat, and this effect was accompanied by inhibition of caspase-3 activity [39]. CBD also reduces cell damage of undifferentiated and retinoic acid differentiated SH-SY5Y cells exposed to 1-methyl-4-phenylpyridinium (MPP+)-A neurotoxin which inhibits mitochondrial complex I, decreases ATP level and enhances ROS production [23,40].…”