Ibudilast suppresses oxaliplatin-induced mechanical allodynia and neurodegeneration in rats

Ibudilast Protects Retinal Bipolar Cells from Excitotoxic Retinal Damage and Activates the mTOR Pathway

Ibudilast, an inhibitor of macrophage migration inhibitory factor (MIF) and phosphodiesterase (PDE), has been recently shown to have neuroprotective effects in a variety of neurologic diseases. We utilize a chick excitotoxic retinal damage model to investigate ibudilast's potential to protect retinal neurons. Using single cell RNA-sequencing (scRNA-seq), we find that MIF, putative MIF receptors CD74 and CD44, and several PDEs are upregulated in different retinal cells during damage. Intravitreal ibudilast is well tolerated in the eye and causes no evidence of toxicity. Ibudilast effectively protects neurons in the inner nuclear layer from NMDA-induced cell death, restores retinal layer thickness on spectral domain optical coherence tomography, and preserves retinal neuron function, particularly for the ON bipolar cells, as assessed by electroretinography. PDE inhibition seems essential for ibudilast's neuroprotection, as AV1013, the analogue that lacks PDE inhibitor activity, is ineffective. scRNA-seq analysis reveals upregulation of multiple signaling pathways, including mTOR, in damaged Müller glia (MG) with ibudilast treatment compared to AV1013. Components of mTORC1 and mTORC2 are upregulated in both bipolar cells and MG with ibudilast. The mTOR inhibitor rapamycin blocked accumulation of pS6 but did not reduce TUNEL positive dying cells. Additionally, through ligand-receptor interaction analysis, crosstalk between bipolar cells and MG may be important for neuroprotection. We have identified several paracrine signaling pathways that are known to contribute to cell survival and neuroprotection and might play essential roles in ibudilast function. These findings highlight ibudilast's potential to protect inner retinal neurons during damage and show promise for future clinical translation.

Pathological Mechanisms and Preventive Strategies of Oxaliplatin-Induced Peripheral Neuropathy

Oxaliplatin, which is widely used in treating cancers such as colorectal cancer, frequently causes peripheral neuropathy. It not only significantly reduces the patient's quality of life due to physical distress but may also result in a change or discontinuation of cancer treatment. Oxaliplatin-induced peripheral neuropathy (OIPN) is classified as acute or chronic depending on the onset time of side effects; however, the prevention and treatment of OIPN has not been established. As these peripheral neuropathies are side effects that occur due to treatment, the administration of effective prophylaxis can effectively prevent their onset. Although transient relief of symptoms such as pain and numbness enable the continuation of cancer treatment, it may result in the worsening of peripheral neuropathy. Thus, understanding the pathological mechanisms of OIPN and finding better preventative measures are important. This review focuses on animal models to address these issues, clarifies the pathological mechanisms of OIPN, and summarizes various approaches to solving OIPN, including targets for preventing OIPN.