The microtubule-stabilizing agent paclitaxel frequently leads to chemotherapy-induced peripheral neuropathy (CIN), which further increases the burden of disease and often necessitates treatment ...limitations. The pathophysiology of CIN appears to involve both “upstream” effects including altered intracellular calcium signaling and activation of calcium dependent proteases such as calpain as well as subsequent “downstream” neuro-inflammatory reactions with cytokine release and macrophage infiltration of dorsal root ganglia. In this study, we aimed to investigate whether these processes are linked by the pro-inflammatory cytokine interleukin-6 (IL-6). We observed that paclitaxel exposure induced IL-6 synthesis in cultured sensory neurons from postnatal Wistar rats, which could be prevented by co-treatment with a calpain inhibitor. This suggests a calcium dependent process. We demonstrate that adult C57BL/6 mice deficient in IL-6 are protected from developing functional and histological changes of paclitaxel-induced neuropathy. Furthermore, pretreatment with an IL-6-neutralizing antibody resulted in the prevention of paclitaxel-induced neuropathy in C57BL/6 mice. Electrophysiological data from our preclinical model was adequately reflected by measurements of patients undergoing paclitaxel therapy for ovarian cancer. In this cohort, measured Il-6 levels correlated with the severity of neuropathy. Our findings demonstrate that IL-6 plays a pivotal role in the pathophysiology of paclitaxel-induced neuropathy per se and that pharmacological or genetic interference with this signaling pathway prevents the development of this potentially debilitating adverse effect. These findings provide a rationale for a clinical trial with IL-6 neutralizing antibodies to prevent dose-limiting neurotoxic adverse effects of paclitaxel chemotherapy.
Polyneuropathy is a frequent and potentially severe side effect of clinical tumor chemotherapy. The goal of this study was to characterize paclitaxel-, cisplatin-, vincristine- and bortezomib-induced ...neuropathy in C57BL/6 mice with a comparative approach. The phenotype of the animals was evaluated at four time points with behavioral and electrophysiological tests, followed by histology. Treatment protocols used in this study were well tolerated and induced a sensory and predominantly axonal polyneuropathy. Behavioral testing revealed normal motor coordination, whereas all mice receiving verum treatment developed mechanical allodynia and distinct gait alterations. Electrophysiological evaluation showed a significant decrease of the caudal sensory nerve action potential amplitude for all cytostatic agents and a moderate reduction of nerve conduction velocity for cisplatin and paclitaxel. This finding was confirmed by histological analysis of the sciatic nerve which showed predominantly axonal damage: Paclitaxel and vincristine affected mostly large myelinated fibers, bortezomib small myelinated fibers and cisplatin damaged all types of myelinated fibers to a similar degree. Neuropathic symptoms developed faster in paclitaxel and vincristine treated animals compared to cisplatin and bortezomib treatment. The animal models in this study can be used to elucidate pathomechanisms underlying chemotherapy-induced polyneuropathy and for the development of novel therapeutic and preventative strategies.
Neuropathic pain as a symptom of sensory nerve damage is a frequent side effect of chemotherapy. The most common behavioral observation in animal models of chemotherapy induced polyneuropathy is the ...development of mechanical allodynia, which is quantified with von Frey filaments. The data from one study, however, cannot be easily compared with other studies owing to influences of environmental factors, inter-rater variability and differences in test paradigms. To overcome these limitations, automated quantitative gait analysis was proposed as an alternative, but its usefulness for assessing animals suffering from polyneuropathy has remained unclear. In the present study, we used a novel mouse model of paclitaxel induced polyneuropathy to compare results from electrophysiology and the von Frey method to gait alterations measured with the Catwalk test. To mimic recently improved clinical treatment strategies of gynecological malignancies, we established a mouse model of dose-dense paclitaxel therapy on the common C57Bl/6 background. In this model paclitaxel treated animals developed mechanical allodynia as well as reduced caudal sensory nerve action potential amplitudes indicative of a sensory polyneuropathy. Gait analysis with the Catwalk method detected distinct alterations of gait parameters in animals suffering from sensory neuropathy, revealing a minimized contact of the hind paws with the floor. Treatment of mechanical allodynia with gabapentin improved altered dynamic gait parameters. This study establishes a novel mouse model for investigating the side effects of dose-dense paclitaxel therapy and underlines the usefulness of automated gait analysis as an additional easy-to-use objective test for evaluating painful sensory polyneuropathy.
Chemotherapy-induced peripheral neuropathy (CIPN) is a frequent, potentially irreversible adverse effect of cytotoxic chemotherapy often leading to a reduction or discontinuation of treatment which ...negatively impacts patients' prognosis. To date, however, neither predictive biomarkers nor preventive treatments for CIPN are available, which is partially due to a lack of suitable experimental models. We therefore aimed to evaluate whether sensory neurons derived from induced pluripotent stem cells (iPSC-DSN) can serve as human disease model system for CIPN. Treatment of iPSC-DSN for 24 h with the neurotoxic drugs paclitaxel, bortezomib, vincristine and cisplatin led to axonal blebbing and a dose dependent decline of cell viability in clinically relevant IC50 ranges, which was not observed for the non-neurotoxic compounds doxorubicin and 5-fluorouracil. Paclitaxel treatment effects were less pronounced after 24 h but prominent when treatment was applied for 72 h. Global transcriptome analyses performed at 24 h, i.e. before paclitaxel-induced cell death occurred, revealed the differential expression of genes of neuronal injury, cellular stress response, and sterol pathways. We further evaluated if known neuroprotective strategies can be reproduced in iPSC-DSN and observed protective effects of lithium replicating findings from rodent dorsal root ganglia cells. Comparing sensory neurons derived from two different healthy donors, we found preliminary evidence that these cell lines react differentially to neurotoxic drugs as expected from the variable presentation of CIPN in patients. In conclusion, iPSC-DSN are a promising platform to study the pathogenesis of CIPN and to evaluate neuroprotective treatment strategies. In the future, the application of patient-specific iPSC-DSN could open new avenues for personalized medicine with individual risk prediction, choice of chemotherapeutic compounds and preventive treatments.
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It was previously reported that high salt dietary conditions can drive autoimmunity and worsen severity and symptoms of autoimmune diseases. Chronic inflammatory demyelinating polyradiculoneuropathy ...(CIDP) is a common autoimmune condition of the peripheral nervous system which leads to progressive paralysis and sensory deficits due to a demyelination and secondary axonal loss of peripheral nerves. We used a previously described model with a knockout of CD86 in non-obese diabetic mice (CD86−/− NOD), which results in the spontaneous development of an autoimmune peripheral neuropathy similar to CIDP and investigated the influence of a high salt diet on functional impairment, electrophysiological parameters, demyelination and neuroinflammation in these mice.
At seven weeks of age, asymptomatic female CD86−/− NOD mice were randomly assigned to a normal or high salt diet containing 4% sodium chloride in food and 1% in water. The diet was continued for a total of 30 weeks.
Mice on the high salt diet showed a delayed onset of clinical symptoms and an ameliorated disease course with a reduced decline of locomotor function. Furthermore, electrophysiological parameters of neuropathy and demyelination were attenuated in mice on the high salt diet, which was confirmed with histological analysis. Additionally, we observed a reduced immune cell infiltration of sciatic nerves in mice which had received the high salt diet.
We demonstrate beneficial effects of high salt diet regarding disease progression, functional, electrophysiological and histological parameters in a transgenic mouse model of spontaneous autoimmune neuropathy.
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•High salt diet ameliorates disease progression of CIDP-like autoimmune polyneuropathy.•High salt diet slows progression of paresis.•High salt diet reduces demyelination.•High salt diet attenuates immune cell infiltration of peripheral nerves.
Neurological immune-related adverse events (irAE-n) are severe and potentially fatal toxicities of immune checkpoint inhibitors (ICI). To date, the clinical significance of neuronal autoantibodies in ...irAE-n is poorly understood. Here, we characterize neuronal autoantibody profiles in patients with irAE-n and compare these with ICI-treated cancer patients without irAE-n.
In this cohort study (DRKS00012668), we consecutively collected clinical data and serum samples of 29 cancer patients with irAE-n (n = 2 pre-ICI, n = 29 post-ICI) and 44 cancer control patients without irAE-n (n = 44 pre- and post-ICI). Using indirect immunofluorescence and immunoblot assays, serum samples were tested for a large panel of neuromuscular and brain-reactive autoantibodies.
IrAE-n patients and controls received ICI treatment targeting programmed death protein (PD-)1 (61% and 62%), programmed death ligand (PD-L)1 (18% and 33%) or PD-1 and cytotoxic T-lymphocyte-associated protein (CTLA-)4 (21% and 5%). Most common malignancies were melanoma (both 55%) and lung cancer (11% and 14%). IrAE-n affected the peripheral nervous system (59%), the central nervous system (21%), or both (21%). Prevalence of neuromuscular autoantibodies was 63% in irAE-n patients, which was higher compared to ICI-treated cancer patients without irAE-n (7%, p <.0001). Brain-reactive autoantibodies targeting surface (anti-GABA
R, -NMDAR, -myelin), intracellular (anti-GFAP, -Zic4, -septin complex), or unknown antigens were detected in 13 irAE-n patients (45%). In contrast, only 9 of 44 controls (20%) presented brain-reactive autoantibodies before ICI administration. However, seven controls developed
brain-reactive autoantibodies after ICI initiation, therefore, prevalence of brain-reactive autoantibodies was comparable between ICI-treated patients with and without irAE-n (p = .36). While there was no clear association between specific brain-reactive autoantibodies and clinical presentation, presence of at least one of six selected neuromuscular autoantibodies (anti-titin, anti-skeletal muscle, anti-heart muscle, anti-LRP4, anti-RyR, anti-AchR) had a sensitivity of 80% (95% CI 0.52-0.96) and a specificity of 88% (95% CI 0.76-0.95) for the diagnosis of myositis, myocarditis, or myasthenia gravis.
Neuromuscular autoantibodies may serve as a feasible marker to diagnose and potentially predict life-threatening ICI-induced neuromuscular disease. However, brain-reactive autoantibodies are common in both ICI-treated patients with and without irAE-n, hence, their pathogenic significance remains unclear.
Chemotherapy-induced peripheral neuropathy (CIPN) and post-chemotherapy cognitive impairment (PCCI) represent major side effects of chemotherapy. Using Sendai virus vectors, ten hiPSC lines from ...patients who had undergone chemotherapy and did or did not develop CIPN and PCCI were generated. Each line was characterized to confirm markers of the undifferentiated state, differentiation potential, genomic integrity, identity verification and reprogramming vector removal. These lines serve as a valuable resource to create two disease models for 1) CIPN (hiPSC lines from five patients with CIPN vs. five without CIPN) and 2) PCCI (hiPSC lines from four patients with PCCI vs. five without PCCI).
Abstract
Background
Neurologic immune-related adverse events (irAE-n) are rare but severe toxicities of immune checkpoint inhibitor (ICI) treatment. To overcome diagnostic and therapeutic challenges, ...a better mechanistic understanding of irAE-n is paramount.
Methods
In this observational cohort study, we collected serum and peripheral blood samples from 34 consecutive cancer patients with irAE-n (during acute illness) and 49 cancer control patients without irAE-n (pre- and on-ICI treatment, n = 44 without high-grade irAEs, n = 5 with high-grade nonneurologic irAEs). Patients received either anti-programmed cell death protein (PD)-1 or anti-PD ligand-1 monotherapy or anti-PD-1/anti-cytotoxic T-lymphocyte-associated protein-4 combination therapy. Most common cancers were melanoma, lung cancer, and hepatocellular carcinoma. Peripheral blood immune profiling was performed using 48-marker single-cell mass cytometry and a multiplex cytokine assay.
Results
During acute illness, patients with irAE-n presented higher frequencies of cluster of differentiation (CD)8+ effector memory type (EM-)1 and central memory (CM) T cells compared to controls without irAEs. Multiorgan immunotoxicities (neurologic + nonneurologic) were associated with higher CD8+ EM1 T cell counts. While there were no B cell changes in the overall cohort, we detected a marked decrease of IgD− CD11c+ CD21low and IgD− CD24+ CD21high B cells in a subgroup of patients with autoantibody-positive irAE-n. We further identified signatures indicative of enhanced chemotaxis and inflammation in irAE-n patients and discovered C-X-C motif chemokine ligand (CXCL)10 as a promising marker to diagnose high-grade immunotoxicities such as irAE-n.
Conclusions
We demonstrate profound and partly subgroup-specific immune cell dysregulation in irAE-n patients, which may guide future biomarker development and targeted treatment approaches.
Graphical Abstract
Graphical Abstract
Suramin is a trypan blue analogon originally developed to treat protozoan infections, which was found to have diverse antitumor effects. One of the most severe side effects in clinical trials was the ...development of a peripheral sensory-motor polyneuropathy. In this study, we aimed to investigate suramin-induced neuropathy with a focus on calcium (Ca2+) homeostasis as a potential pathomechanism. Adult C57Bl/6 mice treated with a single injection of 250 mg/kg bodyweight suramin developed locomotor and sensory deficits, which were confirmed by electrophysiological measurements showing a predominantly sensory axonal-demyelinating polyneuropathy. In a next step, we used cultured dorsal root ganglia neurons (DRGN) as an in vitro cell model to further investigate underlying pathomechanisms. Cell viability of DRGN was significantly decreased after 24-hour suramin treatment with a calculated IC50 of 283 µM. We detected a suramin-induced Ca2+ influx into DRGN from the extracellular space, which could be reduced with the voltage-gated calcium channel (VGCC) inhibitor nimodipine. Co-incubation of suramin and nimodipine partially improved cell viability of DRGN after suramin exposure. In summary, we describe suramin-induced neurotoxic effects on DRGN as well as potentially neuroprotective agents targeting intracellular Ca2+ dyshomeostasis.
Chemotherapy-induced peripheral neuropathy (CIPN) is a frequent and serious side effect of many cytotoxic drugs, including paclitaxel. Despite the identification of treatment options in animal ...models, clinical trials for the treatment or prevention of CIPN have been negative. Major challenges for successful clinical translation of preclinical data include a lack of reproducibility and randomization, small sample sizes and insufficient statistical tests. We therefore conducted a confirmatory, preclinical multicenter randomized controlled replication trial to test the safety and efficacy of three drugs for preventing paclitaxel-induced polyneuropathy: (1) nilotinib, (2) lithium carbonate and (3) interleukin-6-neutralizing antibodies. We preregistered the data analysis plan as well as the two-step study protocol: the optimal doses of the three compounds were assessed first and then tested in a mouse breast cancer xenograft model to compare safety and efficacy.
Unfortunately, toxicity of intraperitoneally administered nilotinib in combination with paclitaxel was observed, and higher-than-expected tumor growth resulted in a lack of power when the trial was analyzed. Thus, although lithium carbonate and IL-6-neutralizing antibodies tended toward neuroprotection, the differences between these groups were not statistically significant. However, the PINPRICS study ultimately still provides important lessons with regard to the planning and conduction of multicenter preclinical trials.
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