Therapeutic indications for HDAC6 inhibitors in the peripheral and central nervous disorders.

INTRODUCTION: Inhibition of the enzymatic function of HDAC6 is currently being explored in clinical trials ranging from peripheral neuropathies to cancers. Advances in selective HDAC6 inhibitor discovery allowed studying highly efficacious brain penetrant and peripheral restrictive compounds for treating PNS and CNS indications. AREAS COVERED: This review explores the multifactorial role of HDAC6 in cells, the common pathological hallmarks of PNS and CNS disorders, and how HDAC6 modulates these mechanisms. Pharmacological inhibition of HDAC6 and genetic knockout/knockdown studies as a therapeutic strategy in PNS and CNS indications were analyzed. Furthermore, we describe the recent developments in HDAC6 PET tracers and their utility in CNS indications. Finally, we explore the advancements and challenges with HDAC6 inhibitor compounds, such as hydroxamic acid, fluoromethyl oxadiazoles, HDAC6 degraders, and thiol-based inhibitors. EXPERT OPINION: Based on extensive preclinical evidence, pharmacological inhibition of HDAC6 is a promising approach for treating both PNS and CNS disorders, given its involvement in neurodegeneration and aging-related cellular processes. Despite the progress in the development of selective HDAC6 inhibitors, safety concerns remain regarding their chronic administration in PNS and CNS indications, and the development of novel compound classes and modalities inhibiting HDAC6 function offer a way to mitigate some of these safety concerns.

Nucleoside Reverse Transcriptase Inhibitors Are the Major Class of HIV Antiretroviral Therapeutics That Induce Neuropathic Pain in Mice.

The development of combination antiretroviral therapy (cART) has transformed human immunodeficiency virus (HIV) infection from a lethal diagnosis into a chronic disease, and people living with HIV on cART can experience an almost normal life expectancy. However, these individuals often develop various complications that lead to a decreased quality of life, some of the most significant of which are neuropathic pain and the development of painful peripheral sensory neuropathy (PSN). Critically, although cART is thought to induce pain pathogenesis, the relative contribution of different classes of antiretrovirals has not been systematically investigated. In this study, we measured the development of pathological pain and peripheral neuropathy in mice orally treated with distinct antiretrovirals at their translational dosages. Our results show that only nucleoside reverse transcriptase inhibitors (NRTIs), not other types of antiretrovirals such as proteinase inhibitors, non-nucleoside reverse transcriptase inhibitors, integrase strand transfer inhibitors, and CCR5 antagonists, induce pathological pain and PSN. Thus, these findings suggest that NRTIs are the major class of antiretrovirals in cART that promote the development of neuropathic pain. As NRTIs form the essential backbone of multiple different current cART regimens, it is of paramount clinical importance to better understand the underlying mechanism to facilitate the design of less toxic forms of these drugs and/or potential mitigation strategies.

Molsidomine provides neuroprotection against vincristine-induced peripheral neurotoxicity through soluble guanylyl cyclase activation.

Peripheral neurotoxicity is a dose-limiting adverse reaction of primary frontline chemotherapeutic agents, including vincristine. Neuropathy can be so disabling that patients drop out of potentially curative therapy, negatively impacting cancer prognosis. The hallmark of vincristine neurotoxicity is axonopathy, yet its underpinning mechanisms remain uncertain. We developed a comprehensive drug discovery platform to identify neuroprotective agents against vincristine-induced neurotoxicity. Among the hits identified, SIN-1-an active metabolite of molsidomine-prevents vincristine-induced axonopathy in both motor and sensory neurons without compromising vincristine anticancer efficacy. Mechanistically, we found that SIN-1's neuroprotective effect is mediated by activating soluble guanylyl cyclase. We modeled vincristine-induced peripheral neurotoxicity in rats to determine molsidomine therapeutic potential in vivo. Vincristine administration induced severe nerve damage and mechanical hypersensitivity that were attenuated by concomitant treatment with molsidomine. This study provides evidence of the neuroprotective properties of molsidomine and warrants further investigations of this drug as a therapy for vincristine-induced peripheral neurotoxicity.

Identification of novel neuroprotectants against vincristine-induced neurotoxicity in iPSC-derived neurons.

Chemotherapy-induced peripheral neuropathy (CIPN) is a disabling side effect of cancer chemotherapy that can often limit treatment options for cancer patients or have life-long neurodegenerative consequences that reduce the patient's quality of life. CIPN is caused by the detrimental actions of various chemotherapeutic agents on peripheral axons. Currently, there are no approved preventative measures or treatment options for CIPN, highlighting the need for the discovery of novel therapeutics and improving our understanding of disease mechanisms. In this study, we utilized human-induced pluripotent stem cell (hiPSC)-derived motor neurons as a platform to mimic axonal damage after treatment with vincristine, a chemotherapeutic used for the treatment of breast cancers, osteosarcomas, and leukemia. We screened a total of 1902 small molecules for neuroprotective properties in rescuing vincristine-induced axon growth deficits. From our primary screen, we identified 38 hit compounds that were subjected to secondary dose response screens. Six compounds showed favorable pharmacological profiles - AZD7762, A-674563, Blebbistatin, Glesatinib, KW-2449, and Pelitinib, all novel neuroprotectants against vincristine toxicity to neurons. In addition, four of these six compounds also showed efficacy against vincristine-induced growth arrest in human iPSC-derived sensory neurons. In this study, we utilized high-throughput screening of a large library of compounds in a therapeutically relevant assay. We identified several novel compounds that are efficacious in protecting different neuronal subtypes from the toxicity induced by a common chemotherapeutic agent, vincristine which could have therapeutic potential in the clinic.

Prazosin as an Adjuvant to Increase Effectiveness of Duloxetine in a Rat Model of Oxaliplatin-Induced Peripheral Neuropathy.

OBJECTIVES: Duloxetine, the only American Society of Clinical Oncology (ASCO) treatment recommended for chemotherapy-induced peripheral neuropathy (CIPN) in cancer survivors, is not effective for 40% of survivors. This study examined the ability of a duloxetine-prazosin combination to prevent the development of allodynia and hyperalgesia in a rat model of oxaliplatin-induced peripheral neuropathy (OPIN). METHODS: Female (n = 24) and male (n = 41) rats were started on duloxetine (15 mg), prazosin (2 mg), or a duloxetine-prazosin combination one week prior to administration of the chemotherapy drug, oxaliplatin, and continued the duloxetine-prazosin combination for 32 days. Behavioral testing for mechanical allodynia and mechanical hyperalgesia was done with selected von Frey filaments over the course of the study. RESULTS: Overall percent paw withdrawal for rats that received the duloxetine-prazosin combination was significantly lower in female (p < .001 for both conditions) and male (p = .029 for allodynia; p < .001 for hyperalgesia) than those that received water. No significant posttreatment differences were found for allodynia or hyperalgesia between rats treated with duloxetine and rats that received the duloxetine-prazosin combination in either sex. CONCLUSIONS: These finding provide preliminary evidence that a duloxetine-prazosin combination can prevent the posttreatment development of allodynia and hyperalgesia in both male and female rats; however, the results suggest that the duloxetine-prazosin combination is no more efficacious than duloxetine alone in preventing chronic OIPN. IMPLICATIONS FOR NURSING PRACTICE: The profession of nursing is built on clinical practice supported by scientific research. The current study addressed the clinical practice problem of prevention and management of painful OIPN, which is a priority area in oncology nursing.

A novel marine-derived mitophagy inducer ameliorates mitochondrial dysfunction and thermal hypersensitivity in paclitaxel-induced peripheral neuropathy.

BACKGROUND AND PURPOSE: Mitochondrial dysfunction contributes to the pathogenesis and maintenance of chemotherapy-induced peripheral neuropathy (CIPN), a significant limitation of cancer chemotherapy. Recently, the stimulation of mitophagy, a pivotal process for mitochondrial homeostasis, has emerged as a promising treatment strategy for neurodegenerative diseases, but its therapeutic effect on CIPN has not been explored. Here, we assessed the mitophagy-inducing activity of 3,5-dibromo-2-(2',4'-dibromophenoxy)-phenol (PDE701), a diphenyl ether derivative isolated from the marine sponge Dysidea sp., and investigated its therapeutic effect on a CIPN model. EXPERIMENTAL APPROACH: Mitophagy activity was determined by a previously established mitophagy assay using mitochondrial Keima (mt-Keima). Mitophagy induction was further verified by western blotting, immunofluorescence, and electron microscopy. Mitochondrial dysfunction was analysed by measuring mitochondrial superoxide levels in SH-SY5Y cells and Drosophila larvae. A thermal nociception assay was used to evaluate the therapeutic effect of PDE701 on the paclitaxel-induced thermal hyperalgesia phenotype in Drosophila larvae. KEY RESULTS: PDE701 specifically induced mitophagy but was not toxic to mitochondria. PDE701 ameliorated paclitaxel-induced mitochondrial dysfunction in both SH-SY5Y cells and Drosophila larvae. Importantly, PDE701 also significantly ameliorated paclitaxel-induced thermal hyperalgesia in Drosophila larvae. Knockdown of ATG5 or ATG7 abolished the effect of PDE701 on thermal hyperalgesia, suggesting that PDE701 exerts its therapeutic effect through mitophagy induction. CONCLUSION AND IMPLICATIONS: This study identified PDE701 as a novel mitophagy inducer and a potential therapeutic compound for CIPN. Our results suggest that mitophagy stimulation is a promising strategy for the treatment of CIPN and that marine organisms are a potential source of mitophagy-inducing compounds.

Gabapentinoids for chemotherapy-induced peripheral neuropathy: systematic review and meta-analysis.

INTRODUCTION: Chemotherapy-induced peripheral neuropathy (CIPN) affects patients' quality of life and treatment effectiveness. Gabapentinoids, like gabapentin and pregabalin, are often used for CIPN treatment, but their efficacy and safety remain uncertain. This study reviews and analyses randomised controlled trial data on this topic. MATERIALS/METHODS: We searched PubMed, Embase and Cochrane CENTRAL until 29 August 2022 for studies on gabapentinoid use in CIPN. Meta-analysis was performed using RevMan V.5.4 and the Metafor package in R. Outcomes included pain scores, quality of life and adverse drug events. RESULTS: For the prevention setting, our meta-analysis shows that pregabalin did not significantly improve average pain (standardised mean difference (SMD) -0.14, 95% CI -0.51 to 0.23; I2=26% (95% CI 0% to >98%)) or quality of life (mean difference (MD) 2.5, 95% CI -4.67 to 9.67; p=0.49) in preventing CIPN compared with placebo. However, it showed a potential trend towards reducing the worst pain (SMD -0.28, 95% CI -0.57 to 0.01; I2=0% (95% CI 0% to 98%; p=0.06)). For the treatment setting, some studies have shown a potential therapeutic effect of gabapentinoids. However, the results are not consistent between studies. Given the studies' heterogeneity, a meta-analysis in treatment setting was not performed. CONCLUSION: There is limited evidence to support the use of gabapentinoids in CIPN. In prevention setting, gabapentinoids do not significantly prevent CIPN. In treatment setting, studies have been inconsistent in their conclusions, lacking definitive benefits over placebo. More comprehensive and higher quality research is needed in the future. PROSPERO REGISTRATION NUMBER: CRD42022361193.

Corneal confocal microscopy detects early nerve regeneration after pharmacological and surgical interventions: Systematic review and meta-analysis.

Corneal confocal microscopy (CCM) is an ophthalmic imaging technique that enables the identification of corneal nerve fibre degeneration and regeneration. To undertake a systematic review and meta-analysis of studies utilizing CCM to assess for corneal nerve regeneration after pharmacological and surgical interventions in patients with peripheral neuropathy. Databases (EMBASE [Ovid], PubMed, CENTRAL and Web of Science) were searched to summarize the evidence from randomized and non-randomized studies using CCM to detect corneal nerve regeneration after pharmacological and surgical interventions. Data synthesis was undertaken using RevMan web. Eighteen studies including 958 patients were included. CCM identified an early (1-8 months) and longer term (1-5 years) increase in corneal nerve measures in patients with peripheral neuropathy after pharmacological and surgical interventions. This meta-analysis confirms the utility of CCM to identify nerve regeneration following pharmacological and surgical interventions. It could be utilized to show a benefit in clinical trials of disease modifying therapies for peripheral neuropathy.

Desloratadine ameliorates paclitaxel-induced peripheral neuropathy and hypersensitivity reactions in mice.

Paclitaxel (PTX) serves as a primary chemotherapy agent against diverse solid tumors including breast cancer, lung cancer, head and neck cancer and ovarian cancer, having severe adverse effects including PTX-induced peripheral neuropathy (PIPN) and hypersensitivity reactions (HSR). A recommended anti-allergic agent diphenhydramine (DIP) has been used to alleviate PTX-induced HSR. Desloratadine (DLT) is a third generation of histamine H1 receptor antagonist, but also acted as a selective antagonist of 5HTR2A. In this study we investigated whether DLT ameliorated PIPN-like symptoms in mice and the underlying mechanisms. PIPN was induced in male mice by injection of PTX (4 mg/kg, i.p.) every other day for 4 times. The mice exhibited 50% reduction in mechanical threshold, paw thermal response latency and paw cold response latency compared with control mice. PIPN mice were treated with DLT (10, 20 mg/kg, i.p.) 30 min before each PTX administration in the phase of establishing PIPN mice model and then administered daily for 4 weeks after the model was established. We showed that DLT administration dose-dependently elevated the mechanical, thermal and cold pain thresholds in PIPN mice, whereas administration of DIP (10 mg/kg, i.p.) had no ameliorative effects on PIPN-like symptoms. We found that the expression of 5HTR2A was selectively elevated in the activated spinal astrocytes of PIPN mice. Spinal cord-specific 5HTR2A knockdown by intrathecal injection of AAV9-5Htr2a-shRNA significantly alleviated the mechanical hyperalgesia, thermal and cold hypersensitivity in PIPN mice, while administration of DLT (20 mg/kg) did not further ameliorate PIPN-like symptoms. We demonstrated that DLT administration alleviated dorsal root ganglion neuronal damage and suppressed sciatic nerve destruction, spinal neuron apoptosis and neuroinflammation in the spinal cord of PIPN mice. Furthermore, we revealed that DLT administration suppressed astrocytic neuroinflammation via the 5HTR2A/c-Fos/NLRP3 pathway and blocked astrocyte-neuron crosstalk by targeting 5HTR2A. We conclude that spinal 5HTR2A inhibition holds promise as a therapeutic approach for PIPN and we emphasize the potential of DLT as a dual-functional agent in ameliorating PTX-induced both PIPN and HSR in chemotherapy. In summary, we determined that spinal 5HTR2A was selectively activated in PIPN mice and DLT could ameliorate the PTX-induced both PIPN- and HSR-like pathologies in mice. DLT alleviated the damages of DRG neurons and sciatic nerves, while restrained spinal neuronal apoptosis and CGRP release in PIPN mice. The underlying mechanisms were intensively investigated by assay against the PIPN mice with 5HTR2A-specific knockdown in the spinal cord by injection of adeno-associated virus 9 (AAV9)-5Htr2a-shRNA. DLT inhibited astrocytic NLRP3 inflammasome activation-mediated spinal neuronal damage through 5HTR2A/c-FOS pathway. Our findings have supported that spinal 5HTR2A inhibition shows promise as a therapeutic strategy for PIPN and highlighted the potential advantage of DLT as a dual-functional agent in preventing against PTX-induced both PIPN and HSR effects in anticancer chemotherapy.

Effect of CYP2C19 polymorphism on response to bortezomib-based therapy in multiple myeloma patients.

BACKGROUND: Bortezomib, a commonly used anti-myeloma drug, is metabolized by liver microsomal enzymes which may be polymorphic and responsible for lack of response in 30% patients. Hence, the association of CYP2C19 polymorphism with treatment response was explored in this study. METHODS: Treatment naive multiple myeloma (MM) patients, eligible for bortezomib-based induction treatment, were recruited as per the inclusion - exclusion criteria. The genotyping of CYP2C19 was done using polymerase chain reaction-restriction fragment length polymorphism for *2, *3 and *17 alleles. The incidence and severity of peripheral neuropathy were noted at follow-up visits and graded as per CTCAE criteria ver 5.0. RESULTS: Total 220 patients were recruited from August 2016 till May 2021; with a mean age of 55.6 (9.5) years and 65.9% males. Bortezomib+cyclophosphamide+dexamethasone (41.8%) and bortezomib+lenalidomide+dexamethasone (38.2%) were the most prescribed regimens. The CYP2C19 was polymorphic in 38.6%, 2.3% and 23.7% patients for *2, *3 and *17 allele respectively. There were 195 treatment responders and 25 non-responders, and CYP2C19*2 allele was different between responders and non-responders (p = 0.02). All extensive metabolisers (n = 54) were noted to be treatment responders. Peripheral neuropathy was reported by 23.2% patients. The frequency of peripheral neuropathy was somewhat lower in patients having either *2/*2 or *3/*3 allele pattern for CYP2C19 (p = 0.44). CONCLUSIONS: Polymorphism in CYP2C19 enzyme is likely to have an impact on bortezomib treatment response and peripheral neuropathy. The study suggests the role of pharmacogenetics in personalised treatment of MM.

Rituximab in non-systemic vasculitic neuropathy: a single-center experience.

OBJECTIVES: This case series reports clinical features and outcome of four patients with non-systemic vasculitic neuropathy (NSVN) treated with the anti-CD20 agent rituximab. METHODS: Clinical, electrophysiological and biopsy data were retrospectively obtained and evaluated. Only patients with pathological definite or probable NSVN were included. Extensive clinical and laboratory work-up excluded systemic vasculitis. Follow-up data for at least 12 months and up to five years is provided. Outcome of the patients was assessed using the MRC-Sum Score, Prineas Score and Neurological Symptom Score. RESULTS: Two of four patients treated with rituximab achieved disease remission and one patient remained stable under anti-CD20 therapy after a required treatment switch due to toxic side effects of cyclophosphamide. One patient deteriorated under rituximab induction. Rituximab was well tolerated in all patients. DISCUSSION: Anti-CD20 therapy might be an alternative in NSVN patients requiring further treatment escalation or treatment switch due to side effects of corticosteroids or cyclophosphamide.

Therapeutic effects of compression therapy on taxane-induced peripheral neuropathy incidence, negative emotions, and sleep disorders in patients with breast cancer.

PURPOSE: To explore the effects of compression therapy on chemotherapy-induced peripheral neuropathy (CIPN), anxiety, depression, and sleep disorders in breast cancer patients administered taxanes. METHODS: Eighty patients with breast cancer undergoing chemotherapy at Tangshan People's Hospital between October 2022 and July 2023 were randomly divided into control (n = 40) and intervention (n = 40) groups. The control group received routine care, while intervention group received compression therapy in addition to routine care (30 min before the infusion of chemotherapy drugs, patients wore surgical gloves on their hands that were one size smaller than the appropriate size and elastic socks on their feet until 30 min after the infusion). The incidence of CIPN, anxiety, depression, and sleep scores, were compared between these groups before and after compression therapy during chemotherapy cycles 2, 4, and 6. RESULTS: The general characteristics did not differ significantly between the groups (P > 0.05). The CIPN incidence, anxiety and depression scores, and sleep scores also did not differ significantly between the two groups before and after the intervention period (P > 0.05). After the fourth and sixth cycles of intervention, the incidence of CIPN (≥ 1 and ≥ 2), anxiety and depression scores, and sleep scores were significantly lower in the intervention group than in the control group (P < 0.05). CONCLUSION: Compression therapy can effectively reduce the incidence of CIPN, as well as improve the level of anxiety, depression, and sleep disorders in chemotherapy patients. Therefore, medical personnel should closely observe the physical and psychological changes in patients undergoing chemotherapy and provide corresponding preventive measures. REGISTRATION NUMBER: RMYY-LLKS-2022-054. DATE OF REGISTRATION: September 25, 2022.

Intravenous immunoglobulin alleviates Japanese encephalitis virus-induced peripheral neuropathy by inhibiting the ASM/ceramide pathway.

Japanese encephalitis virus (JEV) infection is considered a global public health emergency. Severe peripheral neuropathy caused by JEV infection has increased disability and mortality rates in recent years. Because there are very few therapeutic options for JEV infection, prompt investigations of the ability of clinically safe, efficacious and globally available drugs to inhibit JEV infection and ameliorate peripheral neuropathy are urgently needed. In this study, we found that high doses of intravenous immunoglobulin, a function inhibitor of acid sphingomyelinase (FIASMA), inhibited acid sphingomyelinase (ASM) and ceramide activity in the serum and sciatic nerve of JEV-infected rats, reduced disease severity, reversed electrophysiological and histological abnormalities, significantly reduced circulating proinflammatory cytokine levels, inhibited Th1 and Th17 cell proliferation, and suppressed the infiltration of inflammatory CD4 + cells into the sciatic nerve. It also maintained the peripheral nerve-blood barrier without causing severe clinical side effects. In terms of the potential mechanisms, ASM was found to participate in immune cell differentiation and to activate immune cells, thereby exerting proinflammatory effects. Therefore, immunoglobulin is a FIASMA that reduces abnormal immune responses and thus targets the ASM/ceramide system to treat peripheral neuropathy caused by JEV infection.

[Role and place of ipidacrine in the therapy of diseases of the peripheral nervous system. The resolution of the expert council]. / Rol' i mesto ipidakrina v terapii zabolevanii perifericheskoi nervnoi sistemy. Rezolyutsiya Soveta ekspertov.

The resolution of the expert council is devoted to discussing aspects of the use of ipidacrine for the treatment of mononeuropathies, polyneuropathies and radiculopathies of various etiologies. Specialists prepared recommendations for ipidacrine's application in treating peripheral nervous system disorders.

Efficacy of the traditional Chinese medicine, Buyang Huanwu Decoction, at preventing taxane-induced peripheral neuropathy in breast cancer patients: A prospective, randomized, controlled study.

BACKGROUND: Buyang Huanwu Decoction (BYHWD) is a traditional Chinese prescription, originally derived from Yi Lin Gai Cuo during the Qing Dynasty. This study aimed to evaluate the efficacy and safety of BYHWD in the prevention of taxane-induced peripheral neuropathy (TIPN) in patients with breast cancer. METHODS: This single-center, statistician-blinded, parallel-group, simple randomized, no-treatment controlled study was conducted at the China-Japan Friendship Hospital in Beijing. Sixty breast cancer patients scheduled to receive nab-paclitaxel-based chemotherapy were randomly assigned to either the BYHWD group (N = 30) or the control group (N = 30) using simple randomization procedures. The data analysts were unaware of the treatment allocation. The primary efficacy endpoints were the incidence and severity of TIPN in the 2 groups, assessed using the Common Terminology Criteria for Adverse Events (CTCAE) and Patients' Neurotoxicity Questionnaire (PNQ). The secondary efficacy endpoint was the score of Functional Assessment of Cancer Therapy-Breast for both groups. The primary safety endpoints were routine blood test results and liver and renal functions. Both groups were subjected to 4 chemotherapy cycles. Efficacy and safety analyses were conducted on an intention-to-treat basis. RESULTS: The incidence of TIPN in the BYHWD group was 50.0%, which was lower than the 80.0% incidence in the control group (ß = -1.881 [95%CI -3.274, -.488]; P = .008, adjusted). The probability of TIPN in the BYHWD group was 15.2% of that in the control group, representing a significant reduction in incidence (odds ratio = .152, [95%CI .038, 0.614]; P = .008, adjusted). The CTCAE and PNQ grades of the BYHWD group were 1.527 and 1.495 points lower than those of the control group at the same cycle, respectively (CTCAE: ß = -1.527 [95%CI -2.522, -.533]; P = .003, adjusted; PNQ: ß = -1.495 [95%CI -2.501, -.489]; P = .004, adjusted, respectively). After treatment, the Functional Assessment of Cancer Therapy-Breast scores in the BYHWD group were significantly better than those in the control group (P = .003), especially in the physiological, functional, and additional concerns domains. CONCLUSION: Buyang Huanwu decoction (BYHWD) can effectively prevent TIPN and improve the quality of life in patients with breast cancer.

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.

Sensory neuropathy as a manifestation of multiple acyl-coenzyme A dehydrogenase deficiency.

Multiple acyl-coenzyme A dehydrogenase deficiency (MADD) is a rare metabolic disorder which typically manifests with muscle weakness. However, despite late-onset MADD being treatable, it is often misdiagnosed, due in part to the heterogeneity of presentations. We report a case of late-onset MADD manifesting first as a sensory neuropathy before progressing to myopathic symptoms and acute metabolic decompensation. Early diagnostic workup with acylcarnitine profiling and organic acid analysis was critical in patient outcome; metabolic decompensation and myopathic symptoms were completely reversed with riboflavin supplementation and dietary modification, although sensory neuropathy persisted. Clinical consideration of MADD as part of the differential diagnosis of neuropathy with myopathy is crucial for a timely diagnosis and treatment of MADD.

Analysis of the contributing role of drug transport across biological barriers in the development and treatment of chemotherapy-induced peripheral neuropathy.

BACKGROUND: Chemotherapy-induced peripheral neuropathy (CIPN) represents a major unmet medical need that currently has no preventive and/or curative treatment. This is, among others, driven by a poor understanding of the contributive role of drug transport across biological barriers to target-site exposure. METHODS: Here, we systematically investigated the transport of 11 small-molecule drugs, both, associated and not with CIPN development, at conventional (dorsal root ganglia, sciatic nerve) and non-conventional (brain, spinal cord, skeletal muscle) CIPN sites. We developed a Combinatory Mapping Approach for CIPN, CMA-CIPN, combining in vivo and in vitro elements. RESULTS: Using CMA-CIPN, we determined the unbound tissue-to-plasma concentration ratio (Kp,uu) and the unbound intracellular-to-extracellular concentration ratio (Kp,uu,cell), to quantitatively assess the extent of unbound drug transport across endothelial interfaces and parenchymal cellular barriers of investigated CIPN-sites, respectively, in a rat model. The analysis revealed that unique pharmacokinetic characteristics underly time-dependent accumulation of the CIPN-positive drugs paclitaxel and vincristine at conventional (dorsal root ganglia and sciatic nerve) and non-conventional (skeletal muscle) CIPN sites. Investigated CIPN-positive drugs displayed intracellular accumulation contrary to CIPN-negative drugs nilotinib and methotrexate, which lacked this feature in all investigated tissues. CONCLUSIONS: Hence, high unbound drug intracellular and extracellular exposure at target sites, driven by an interplay of drug transport across the endothelial and parenchymal cellular barriers, is a predisposing factor to CIPN development for CIPN-positive drugs. Critical drug-specific features of unbound drug disposition at various CIPN- sites provide invaluable insights into understanding the pharmacological/toxicological effects at the target-sites which will inform new strategies for monitoring and treatment of CIPN.

Compression therapy using surgical gloves is ineffective for the prevention of vincristine-induced neuropathy in patients with malignant lymphoma.

PURPOSE: Vincristine (VCR) often induces peripheral neuropathy (PN) as an adverse event. Currently, there is no consensus on the prevention of vincristine-induced PN (VIPN). In this study, we aimed to investigate the efficacy of compression therapy using surgical gloves for preventing VIPN. METHODS: Patients with malignant lymphoma (vincristine-naïve) who were receiving chemotherapy with cyclophosphamide, doxorubicin, VCR, and prednisolone, with or without rituximab, every 3 weeks for six cycles were eligible. For every VCR infusion, each patient wore two one-size-smaller gloves on one hand (study hand) for 90 min. The other hand was left bare (control hand). PN was assessed at each treatment using the Common Terminology Criteria for Adverse Events ver. 4.0. RESULTS: Fifty-one patients with malignant lymphoma were enrolled and 44 were evaluated. At 1 month after treatment, the occurrence rates of grade ≥ 2 sensory PN were 13.6 and 13.6% in the study and control hands, respectively (p = 1.0), and those of grade ≥ 2 motor PN were 15.9 and 15.9% in the study and control hands, respectively (p = 1.0). CONCLUSION: Compression therapy using surgical gloves showed no significant effect for the prevention of VIPN. TRIAL REGISTRATION: November 1, 2018, National University Hospital Council of Japan (UMIN 000034145).