Nerve Regeneration Using Compartmentalized System in CIPN Model.

The analysis of nerve regeneration in the chemotherapy-induced peripheral neuropathy (CIPN) model can be achieved using the compartmentalized culture system. This system enables us to isolate the cell body from the axon physically and fluidically, therefore allowing for the independent manipulation of the cell body and axons. Compartmentalized chambers mimic the human body conditions, and can be used to study axonal degeneration, disease modeling, and drug screening. This culture system is applied to the CIPN model to study and analyze axonal behavior in response to paclitaxel (PTX) with and without fluocinolone acetonide (FA) and to better understand the site-specific target of PTX. Therefore, this compartmentalized system allows for the independent treatment of chemotherapy drugs to the cell body or axonal side which enables monitoring their reaction as a result of the treatment.

Phytic Acid Maintains Peripheral Neuron Integrity and Enhances Survivability against Platinum-Induced Degeneration via Reducing Reactive Oxygen Species and Enhancing Mitochondrial Membrane Potential.

Phytic acid (PA) has been reported to possess anti-inflammatory and antioxidant properties that are critical for neuroprotection in neuronal disorders. This raises the question of whether PA can effectively protect sensory neurons against chemotherapy-induced peripheral neuropathy (CIPN). Peripheral neuropathy is a dose-limiting side effect of chemotherapy treatment often characterized by severe and abnormal pain in hands and feet resulting from peripheral nerve degeneration. Currently, there are no effective treatments available that can prevent or cure peripheral neuropathies other than symptomatic management. Herein, we aim to demonstrate the neuroprotective effects of PA against the neurodegeneration induced by the chemotherapeutics cisplatin (CDDP) and oxaliplatin. Further aims of this study are to provide the proposed mechanism of PA-mediated neuroprotection. The neuronal protection and survivability against CDDP were characterized by axon length measurements and cell body counting of the dorsal root ganglia (DRG) neurons. A cellular phenotype study was conducted microscopically. Intracellular reactive oxygen species (ROS) was estimated by fluorogenic probe dichlorofluorescein. Likewise, mitochondrial membrane potential (MMP) was assessed by fluorescent MitoTracker Orange CMTMRos. Similarly, the mitochondria-localized superoxide anion radical in response to CDDP with and without PA was evaluated. The culture of primary DRG neurons with CDDP reduced axon length and overall neuronal survival. However, cotreatment with PA demonstrated that axons were completely protected and showed increased stability up to the 45-day test duration, which is comparable to samples treated with PA alone and control. Notably, PA treatment scavenged the mitochondria-specific superoxide radicals and overall intracellular ROS that were largely induced by CDDP and simultaneously restored MMP. These results are credited to the underlying neuroprotection of PA in a platinum-treated condition. The results also exhibited that PA had a synergistic anticancer effect with CDDP in ovarian cancer in vitro models. For the first time, PA's potency against CDDP-induced PN is demonstrated systematically. The overall findings of this study suggest the application of PA in CIPN prevention and therapeutic purposes.

Electrical stimulation enhances mitochondrial trafficking as a neuroprotective mechanism against chemotherapy-induced peripheral neuropathy.

Electrical stimulation (ESTIM) has shown to be an effective symptomatic treatment to treat pain associated with peripheral nerve damage. However, the neuroprotective mechanism of ESTIM on peripheral neuropathies is still unknown. In this study, we identified that ESTIM has the ability to enhance mitochondrial trafficking as a neuroprotective mechanism against chemotherapy-induced peripheral neuropathies (CIPNs). CIPN is a debilitating and painful sequalae of anti-cancer chemotherapy treatment which results in degeneration of peripheral nerves. Mitochondrial dynamics were analyzed within axons in response to two different antineoplastic mechanisms by chemotherapy drug treatments paclitaxel and oxaliplatin in vitro. Mitochondrial trafficking response to chemotherapy drug treatment was observed to decrease in conjunction with degeneration of distal axons. Using low-frequency ESTIM, we observed enhanced mitochondrial trafficking to be a neuroprotective mechanism against CIPN. This study confirms ESTIM enhances regeneration of peripheral nerves by increased mitochondrial trafficking.