Mechanisms of ARA290 in counteracting cadmium-triggered neurotoxicity in PC12 cells.

Abstract

Erythropoietin (EPO) is known for its role in hematopoiesis and also exhibits anti-inflammatory, anti-apoptotic, antioxidant, and cytoprotective properties. However, its clinical application is limited by hematopoietic side effects. ARA290, a non-hematopoietic derivative of EPO, selectively activates the innate repair receptor (IRR) and replicates these protective effects without the associated hematopoietic complications. Cadmium (Cd), a prevalent environmental toxin, causes neurotoxic damage through mechanisms such as oxidative stress, genotoxicity, apoptosis, and inflammation. This study explored ARA290's neuroprotective effects against cadmium-induced toxicity in PC12 cells, an in vitro model for neuronal health. PC12 cells pretreated with ARA290 showed significantly improved cell viability in the MTT assay, indicating reduced cytotoxicity. The comet assay revealed decreased DNA damage, suggesting reduced genotoxicity. ARA290 also alleviated oxidative stress, as evidenced by reduced levels of reactive oxygen species (ROS) and malondialdehyde (MDA), alongside increased glutathione (GSH), total antioxidant capacity (TAC), and superoxide dismutase (SOD) activities. A marker of apoptosis, TUNEL-positive cells, was significantly reduced. Additionally, ARA290 decreased inflammatory markers such as TNF alpha, IL1ß and IL 6. These findings demonstrate that ARA290, via IRR activation, provides robust neuroprotection against cadmium-induced toxicity, suggesting a multi-faceted protective mechanism. This highlights ARA290's potential therapeutic role in managing heavy metal-induced neurotoxicity and supports further research into its long-term effects and applications in other neurodegenerative diseases or conditions involving environmental toxins.

Highlights: ARA290 as a Neuroprotective Agent: ARA290, a modified form of erythropoietin that doesn't affect blood production, shows promising neuroprotective effects. It helps counteract the harmful effects of cadmium exposure on nerve cells by reducing oxidative stress, inflammation, cell death, and DNA damage.Reducing Oxidative Stress: ARA290 plays a key role in lowering oxidative stress by cutting down on harmful molecules like reactive oxygen species (ROS) and malondialdehyde (MDA). At the same time, it boosts the body's natural antioxidant defenses, including glutathione (GSH), superoxide dismutase (SOD), and overall antioxidant capacity.Protecting DNA Integrity: By reducing DNA damage caused by cadmium, ARA290 helps preserve the genetic stability of nerve cells. This protective effect is evident in laboratory tests, where it lowers the extent of DNA damage seen in the comet assay.Fighting Inflammation and Cell Death: ARA290 also has strong anti-inflammatory and anti-apoptotic effects. It reduces levels of inflammation markers like TNF-α, IL-1β, and IL-6, and significantly cuts down on nerve cell death, as seen in fewer TUNEL-positive cells in experiments.A Therapeutic Promise: Overall, these findings underscore ARA290's ability to protect the nervous system through multiple pathways. This makes it a promising candidate for treating cadmium-induced nerve damage and potentially other neurodegenerative conditions.