RESUMO
BACKGROUND AND AIMS: The expanding use of chemotherapy in curative cancer treatment has simultaneously resulted in a substantial and growing cohort of cancer survivors with prolonged disability from chemotherapy-induced peripheral neuropathy (CIPN). CIPN is associated with several commonly prescribed chemotherapeutics, including taxanes, platinum-based drugs, vinca alkaloids, bortezomib and thalidomide. These distinct classes of chemotherapeutics, with their varied neurotoxic mechanisms, often cause patients to suffer from a broad profile of neuropathic symptoms including chronic numbness, paraesthesia, loss of proprioception or vibration sensation and neuropathic pain. Decades of investigation by numerous research groups have provided substantial insights describing this disease. Despite these advances, there is currently no effective curative or preventative treatment option for CIPN and only the dual serotonin-norepinephrine reuptake inhibitor Duloxetine is recommended by clinical guidelines for the symptomatic treatment of painful CIPN. METHODS: In this review, we examine current preclinical models, with our analysis focused on translational relevance and value. RESULTS: Animal models have been pivotal in achieving a better understanding of the pathogenesis of CIPN. However, it has been challenging for researchers to develop appropriate preclinical models that are effective vehicles for the discovery of translatable treatment options. INTERPRETATION: Further development of preclinical models targeting translational relevance will promote value for preclinical outcomes in CIPN studies.
Assuntos
Antineoplásicos , Neoplasias , Neuralgia , Alcaloides de Vinca , Animais , Antineoplásicos/toxicidade , Neoplasias/tratamento farmacológico , Neuralgia/tratamento farmacológico , Modelos Animais de DoençasRESUMO
BACKGROUND: Genetic risk factors for chemotherapy-induced peripheral neuropathy (CIPN), a major dose-limiting side-effect of paclitaxel, are not well understood. METHODS: We performed a genome-wide association study (GWAS) in 183 paclitaxel-treated patients to identify genetic loci associated with CIPN assessed via comprehensive neuropathy phenotyping tools (patient-reported, clinical and neurological grading scales). Bioinformatic analyses including pathway enrichment and polygenic risk score analysis were used to identify mechanistic pathways of interest. RESULTS: In total, 77% of the cohort were classified with CIPN (n = 139), with moderate/severe neuropathy in 36%. GWAS was undertaken separately for the three measures of CIPN. GWAS of patient-reported CIPN identified 4 chromosomal regions that exceeded genome-wide significance (rs9846958, chromosome 3; rs117158921, chromosome 18; rs4560447, chromosome 4; rs200091415, chromosome 10). rs4560447 is located within a protein-coding gene, LIMCH1, associated with actin and neural development and expressed in the dorsal root ganglia (DRG). There were additional risk loci that exceeded the statistical threshold for suggestive genome-wide association (P < 1 × 10-5) for all measures. A polygenic risk score calculated from the top 46 ranked SNPs was highly correlated with patient-reported CIPN (r2 = 0.53; P = 1.54 × 10-35). Overlap analysis was performed to identify 3338 genes which were in common between the patient-reported CIPN, neurological grading scale and clinical grading scale GWAS. The common gene set was subsequently analysed for enrichment of gene ontology (GO) and Reactome pathways, identifying a number of pathways, including the axon development pathway (GO:0061564; P = 1.78 × 10-6) and neuronal system (R-HSA-112316; adjusted P = 3.33 × 10-7). CONCLUSIONS: Our findings highlight the potential role of axon development and regeneration pathways in paclitaxel-induced CIPN.
Assuntos
Estudo de Associação Genômica Ampla , Doenças do Sistema Nervoso Periférico , Humanos , Paclitaxel/efeitos adversos , Ontologia Genética , Biologia Computacional , Doenças do Sistema Nervoso Periférico/induzido quimicamente , Doenças do Sistema Nervoso Periférico/genéticaRESUMO
INTRODUCTION/AIMS: Clinically, the chemotherapeutic agent oxaliplatin can cause peripheral neuropathy, impaired balance, and muscle wastage. Using a preclinical model, we investigated whether exercise intervention could improve these adverse conditions. METHODS: Mice were chronically treated with oxaliplatin alone or in conjunction with exercise. Behavioral studies, including mechanical allodynia, rotarod, open-field, and grip-strength tests, were performed. After euthanasia, multiple organs and four different muscle types were dissected and weighed. The cross-sectional area (CSA) of muscle fibers in the gastrocnemius muscle was assessed and gene expression analysis performed on the forelimb triceps muscle. RESULTS: Oxaliplatin-treated mice displayed reduced weight gain, mechanical allodynia, and exploratory behavior deficits that were not significantly improved by exercise. Oxaliplatin-treated exercised mice showed modest evidence of reduced muscle wastage compared with mice treated with oxaliplatin alone, and exercised mice demonstrated evidence of a mild increase in CSA of muscle fibers. DISCUSSION: Exercise intervention did not improve signs of peripheral neuropathy but moderately reduced the negative impact of oxaliplatin chemotherapy related to muscle morphology, suggesting the potential for exploring the impact of exercise on reducing oxaliplatin-induced neuromuscular toxicity in cancer patients.
Assuntos
Hiperalgesia/terapia , Doenças do Sistema Nervoso Periférico/terapia , Condicionamento Físico Animal/fisiologia , Animais , Antineoplásicos/farmacologia , Modelos Animais de Doenças , Hiperalgesia/induzido quimicamente , Masculino , Camundongos Endogâmicos C57BL , Oxaliplatina/farmacologia , Limiar da Dor/efeitos dos fármacos , Doenças do Sistema Nervoso Periférico/induzido quimicamenteRESUMO
Peripheral nerve injuries caused by focal constriction are characterised by local nerve ischaemia, axonal degeneration, demyelination, and neuroinflammation. The aim of this study was to understand temporal changes in the excitability properties of injured motor axons in a mouse model of nerve constriction injury (NCI). The excitability of motor axons following unilateral sciatic NCI was studied in male C57BL/6J mice distal to the site of injury at the acute (6 hours-1 week) and chronic (up to 20 weeks) phases of injury, using threshold tracking. Multiple measures of nerve excitability, including strength-duration properties, threshold electrotonus, current-threshold relationship, and recovery cycle were examined using the automated nerve excitability protocol (TRONDNF). Acutely, injured motor axons developed a pattern of excitability characteristic of ischemic depolarisation. In most cases, the sciatic nerve became transiently inexcitable. When a liminal compound muscle action potential could again be recorded, it had an increase in threshold and latency, compared to both pre-injury baseline and sham-injured groups. These axons showed a greater threshold change in response to hyperpolarising threshold electrotonus and a significant upward shift in the recovery cycle. Mathematical modelling suggested that the changes seen in chronically injured axons involve shortened internodes, reduced myelination, and exposed juxtaparanodal fast K+ conductances. The findings of this study demonstrate long-term changes in motor excitability following NCI (involving alterations in axonal properties and ion channel activity) and are important for understanding the mechanisms of neurapraxic injuries and traumatic mononeuropathies.
Assuntos
Axônios/fisiologia , Fenômenos Eletrofisiológicos/fisiologia , Neurônios Motores/fisiologia , Traumatismos dos Nervos Periféricos/fisiopatologia , Nervo Isquiático/fisiopatologia , Animais , Constrição , Modelos Animais de Doenças , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Modelos Neurológicos , Nervo Isquiático/lesõesRESUMO
Sensory problems such as neuropathic pain are common and debilitating symptoms in multiple sclerosis (MS), an autoimmune inflammatory disorder of the CNS. Regulatory T (Treg) cells are critical for maintaining immune homeostasis, but their role in MS-associated pain remains unknown. Here, we demonstrate that Treg cell ablation is sufficient to trigger experimental autoimmune encephalomyelitis (EAE) and facial allodynia in immunized female mice. In EAE-induced female mice, adoptive transfer of Treg cells and spinal delivery of the Treg cell cytokine interleukin-35 (IL-35) significantly reduced facial stimulus-evoked pain and spontaneous pain independent of disease severity and increased myelination of the facial nociceptive pathway. The effects of intrathecal IL-35 therapy were Treg-cell dependent and associated with upregulated IL-10 expression in CNS-infiltrating lymphocytes and reduced monocyte infiltration in the trigeminal afferent pathway. We present evidence for a beneficial role of Treg cells and IL-35 in attenuating pain associated with EAE independently of motor symptoms by decreasing neuroinflammation and increasing myelination.SIGNIFICANCE STATEMENT Pain is a highly prevalent symptom affecting the majority of multiple sclerosis (MS) patients and dramatically affects overall health-related quality of life; however, this is a research area that has been largely ignored. Here, we identify for the first time a role for regulatory T (Treg) cells and interleukin-35 (IL-35) in suppressing facial allodynia and facial grimacing in animals with experimental autoimmune encephalomyelitis (EAE). We demonstrate that spinal delivery of Treg cells and IL-35 reduces pain associated with EAE by decreasing neuroinflammation and increasing myelination independently of motor symptoms. These findings increase our understanding of the mechanisms underlying pain in EAE and suggest potential treatment strategies for pain relief in MS.
Assuntos
Encefalomielite Autoimune Experimental/imunologia , Interleucinas/imunologia , Neuralgia/imunologia , Linfócitos T Reguladores/imunologia , Transferência Adotiva , Animais , Encefalomielite Autoimune Experimental/complicações , Feminino , Hiperalgesia/tratamento farmacológico , Hiperalgesia/etiologia , Hiperalgesia/imunologia , Interleucina-10/imunologia , Interleucinas/administração & dosagem , Camundongos Endogâmicos C57BL , Neuralgia/tratamento farmacológico , Neuralgia/etiologiaRESUMO
Oxaliplatin chemotherapy produces acute changes in peripheral nerve excitability in humans by modulating voltage-gated Na+ channel activity. However, there are few animal studies of oxaliplatin-induced neuropathy that demonstrate similar changes in excitability. In the present study, we measured the excitability of motor and sensory caudal nerve in C57BL/6 mice after oxaliplatin injections either systemically (intraperitoneal) or locally (intramuscular at the base of the tail). As opposed to intraperitoneal administration of oxaliplatin, a single intramuscular injection of oxaliplatin produced changes in both motor and sensory axons. In motor axons, oxaliplatin caused a greater change in response to long-lasting depolarization and an upward shift in the recovery cycle, particularly at 24 h [depolarizing threshold electrotonus (TEd) 10-20 ms, P = 0.0095; TEd 90-100 ms, P = 0.0056) and 48 h (TEd 10-20 ms, P = 0.02; TEd 90-100 ms, P = 0.04) posttreatment. Oxaliplatin treatment also stimulated the production of afterdischarges in motor axons. These changes were transient and showed dose dependence. Mathematical modeling demonstrated that these changes could be accounted for by slowing inactivation of voltage-gated Na+ channels by 73.3% and reducing fast K+ conductance by 47% in motor axons. In sensory axons, oxaliplatin caused an increase in threshold, a reduction in peak amplitude, and greater threshold changes to strong hyperpolarizing currents on days 4 and 8. Thus, local administration of oxaliplatin produced clinically relevant changes in nerve excitability in mice and may provide an alternative approach for the study of acute oxaliplatin-induced neurotoxicity.NEW & NOTEWORTHY We present a novel mouse model of acute oxaliplatin-induced peripheral neurotoxicity that is comparable to clinical observations. Intramuscular injection of oxaliplatin produced acute changes in motor nerve excitability that were attributable to alterations in Na+ and K+ channel activity. Conversely, we were unable to show any significant changes in nerve excitability with systemic intraperitoneal injections of oxaliplatin. This study suggests that local intramuscular injection is a valid approach for modelling oxaliplatin-induced peripheral neuropathy in animals.
Assuntos
Antineoplásicos/efeitos adversos , Axônios/efeitos dos fármacos , Fenômenos Eletrofisiológicos/efeitos dos fármacos , Neurônios Motores/efeitos dos fármacos , Síndromes Neurotóxicas/fisiopatologia , Oxaliplatina/efeitos adversos , Doenças do Sistema Nervoso Periférico/induzido quimicamente , Doenças do Sistema Nervoso Periférico/fisiopatologia , Células Receptoras Sensoriais/efeitos dos fármacos , Animais , Antineoplásicos/administração & dosagem , Modelos Animais de Doenças , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Modelos Teóricos , Oxaliplatina/administração & dosagem , Pesquisa Translacional BiomédicaRESUMO
INTRODUCTION: Muscle wasting is a frequent, debilitating complication of cancer. The impact of colorectal cancer chemotherapeutic oxaliplatin on the development of muscle loss and associated molecular changes is of clinical importance. METHODS: C57BL/6J male mice were treated with oxaliplatin. Total body weights were measured and behavioral studies performed. Hindlimb muscle weights (gastrocnemius and soleus) were recorded in conjunction with gene and protein expression analysis. RESULTS: Oxaliplatin-treated mice displayed reduced weight gain and behavioral deficits. Mice treated over a shorter course had significantly increased STAT3 phosphorylation in gastrocnemius muscles. Mice receiving extended oxaliplatin treatment demonstrated reduced hindlimb muscle mass with upregulation of myopathy-associated genes Foxo3, MAFbx, and Bnip3. DISCUSSION: The findings suggest that oxaliplatin treatment can directly disrupt skeletal muscle homeostasis and promote muscle loss, which may be clinically relevant in the context of targeting fatigue and weakness in cancer patients. Muscle Nerve 57: 650-658, 2018.
Assuntos
Antineoplásicos/farmacologia , Expressão Gênica/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Oxaliplatina/farmacologia , Animais , Peso Corporal/efeitos dos fármacos , Proteína Forkhead Box O3/efeitos dos fármacos , Proteína Forkhead Box O3/genética , Membro Posterior , Masculino , Proteínas de Membrana/efeitos dos fármacos , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Mitocondriais/efeitos dos fármacos , Proteínas Mitocondriais/genética , Proteínas Musculares/efeitos dos fármacos , Proteínas Musculares/genética , Músculo Esquelético/metabolismo , Tamanho do Órgão/efeitos dos fármacos , Proteínas Ligases SKP Culina F-Box/efeitos dos fármacos , Proteínas Ligases SKP Culina F-Box/genética , Fator de Transcrição STAT3/efeitos dos fármacos , Fator de Transcrição STAT3/metabolismoRESUMO
Non-invasive nerve excitability techniques have provided valuable insight into the understanding of neurological disorders. The widespread use of mice in translational research on peripheral nerve disorders and by pharmaceutical companies during drug development requires valid and reliable models that can be compared to humans. This study established a novel experimental protocol that enables comparative assessment of the excitability properties of motor and sensory axons at the same site in mouse caudal nerve, compared the mouse data to data for motor and sensory axons in human median nerve at the wrist, and constructed a mathematical model of the excitability of mouse axons. In a separate study, ischaemia was employed as an experimental manoeuvre to test the translational utility of this preparation. The patterns of mouse sensory and motor excitability were qualitatively similar to human studies under normal and ischaemic conditions. The most conspicuous differences between mouse and human studies were observed in the recovery cycle and the response to hyperpolarization. Modelling showed that an increase in temperature in mouse axons could account for most of the differences in the recovery cycle. The modelling also suggested a larger hyperpolarization-activated conductance in mouse axons. The kinetics of this conductance appeared to be much slower raising the possibility that an additional or different hyperpolarization-activated cyclic-nucleotide gated (HCN) channel isoform underlies the accommodation to hyperpolarization in mouse axons. Given a possible difference in HCN isoforms, caution should be exercised in extrapolating from studies of mouse motor and sensory axons to human nerve disorders.
Assuntos
Potenciais de Ação/fisiologia , Modelos Animais , Neurônios Motores/fisiologia , Células Receptoras Sensoriais/fisiologia , Animais , Axônios/fisiologia , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Systemic administration of a Connexin43 mimetic peptide, Peptide5, has been shown to reduce secondary tissue damage and improve functional recovery after spinal cord injury (SCI). This study investigated safety measures and potential off-target effects of Peptide5 systemic administration. Rats were subjected to a mild contusion SCI using the New York University impactor. One cohort was injected intraperitoneally with a single dose of fluorescently labelled Peptide5 and euthanised at 2 or 4 h post-injury for peptide distribution analysis. A second cohort received intraperitoneal injections of Peptide5 or a scrambled peptide and was culled at 8 or 24 h post-injury for the analysis of connexin proteins and systemic cytokine profile. We found that Peptide5 did not cross the blood-spinal cord barrier in control animals, but reached the lesion area in the spinal cord-injured animals without entering non-injured tissue. There was no evidence that the systemic administration of Peptide5 modulates Connexin43 protein expression or hemichannel closure in the heart and lung tissue of SCI animals. The expression levels of other major connexin proteins including Connexin30 in astrocytes, Connexin36 in neurons and Connexin47 in oligodendrocytes were also unaltered by systemic delivery of Peptide5 in either the injured or non-injured spinal cords. In addition, systemic delivery of Peptide5 had no significant effect on the plasma levels of cytokines, chemokines or growth factors. These data indicate that the systemic delivery of Peptide5 is unlikely to cause any off-target or adverse effects and may thus be a safe treatment option for traumatic SCI.
Assuntos
Materiais Biomiméticos/farmacologia , Conexina 43/farmacologia , Traumatismos da Medula Espinal/tratamento farmacológico , Animais , Materiais Biomiméticos/administração & dosagem , Materiais Biomiméticos/efeitos adversos , Materiais Biomiméticos/farmacocinética , Conexina 43/administração & dosagem , Conexina 43/efeitos adversos , Conexina 43/farmacocinética , Modelos Animais de Doenças , Feminino , Ratos , Ratos Sprague-DawleyRESUMO
The use of 3-dimensional (3D) collagen gels has yielded new insights into the migratory behaviour of cancer cells. While the large GTPase dynamin has emerged as an important regulator of cancer cell migration and invasion under 2D conditions, its role in 3D migration is unclear. We have used a potent dynamin modulator, a bis-tyrphostin derivative, Ryngo® 1-23, to investigate the role of dynamin in 3D migration in 3 different cell lines. The compound specifically inhibits persistent, elongated 3D migration in U87MG and SMA-560 cells. Treated U87MG cells adopt a rounded morphology that is not due to apoptosis, loss of matrix metalloprotease activity or inhibition of clathrin-mediated endocytosis. Given that Ryngo 1-23 is known to regulate dynamin oligomerisation and actin dynamics at the leading edge, we analysed actin filament distribution. Ryngo 1-23 induced a switch in actin filament organization in 3D cultures resulting in the generation of multiple short actin-rich microspikes. Correlated with the change in actin filament distribution, cells displayed reduced collagen gel contraction. Since acto-myosin force transmission to the extra-cellular matrix underpins persistent, elongated migration, our results suggest that Ryngo 1-23 modulates this process in 3D migration via dynamin-mediated regulation of acto-myosin force transmission to the extra-cellular matrix.
Assuntos
Movimento Celular/fisiologia , Forma Celular/fisiologia , Dinaminas/fisiologia , Animais , Movimento Celular/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Colágeno/química , Ácidos Cumáricos/farmacologia , Cianoacrilatos/farmacologia , Dinaminas/antagonistas & inibidores , Géis , Humanos , Imageamento Tridimensional , Ratos , Alicerces Teciduais , Células Tumorais Cultivadas , Tirfostinas/farmacologiaRESUMO
BACKGROUND: T cells have been implicated in neuropathic pain that is caused by peripheral nerve injury. Immunogenic myelin basic protein (MBP) peptides have been shown to initiate mechanical allodynia in a T cell-dependent manner. Antagonistic altered peptide ligands (APLs) are peptides with substitutions in amino acid residues at T cell receptor contact sites and can inhibit T cell function and modulate inflammatory responses. In the present study, we studied the effects of immunization with MBP-derived APL on pain behavior and neuroinflammation in an animal model of peripheral nerve injury. METHODS: Lewis rats were immunized subcutaneously at the base of the tail with either a weakly encephalitogenic peptide of MBP (cyclo-MBP87-99) or APL (cyclo-(87-99)[A(91),A(96)]MBP87-99) in complete Freund's adjuvant (CFA) or CFA only (control), following chronic constriction injury (CCI) of the left sciatic nerve. Pain hypersensitivity was tested by measurements of paw withdrawal threshold to mechanical stimuli, regulatory T cells in spleen and lymph nodes were analyzed by flow cytometry, and immune cell infiltration into the nervous system was assessed by immunohistochemistry (days 10 and 30 post-CCI). Cytokines were measured in serum and nervous tissue of nerve-injured rats (day 10 post-CCI). RESULTS: Rats immunized with the APL cyclo-(87-99)[A(91),A(96)]MBP87-99 had significantly reduced mechanical pain hypersensitivity in the ipsilateral hindpaw compared to cyclo-MBP87-99-treated and control rats. This was associated with significantly decreased infiltration of T cells and ED1+ macrophages in the injured nerve of APL-treated animals. The percentage of anti-inflammatory (M2) macrophages was significantly upregulated in the APL-treated rats on day 30 post-CCI. Compared to the control rats, microglial activation in the ipsilateral lumbar spinal cord was significantly increased in the MBP-treated rats, but was not altered in the rats immunized with the MBP-derived APL. In addition, immunization with the APL significantly increased splenic regulatory T cells. Several cytokines were significantly altered after CCI, but no significant difference was observed between the APL-treated and control rats. CONCLUSIONS: These results suggest that immune deviation by active immunization with a non-encephalitogenic MBP-derived APL mediates an analgesic effect in animals with peripheral nerve injury. Thus, T cell immunomodulation warrants further investigation as a possible therapeutic strategy for the treatment of peripheral neuropathic pain.
Assuntos
Hiperalgesia/tratamento farmacológico , Hiperalgesia/etiologia , Neuropatia Ciática/complicações , Vacinação/métodos , Animais , Chaperonina 60/imunologia , Citocinas/sangue , Modelos Animais de Doenças , Adjuvante de Freund/efeitos adversos , Lateralidade Funcional , Gânglios Espinais/citologia , Macrófagos/metabolismo , Masculino , Proteína Básica da Mielina/efeitos adversos , Proteína Básica da Mielina/imunologia , Limiar da Dor/efeitos dos fármacos , Fragmentos de Peptídeos/efeitos adversos , Fragmentos de Peptídeos/imunologia , Ratos , Ratos Endogâmicos Lew , Células Receptoras Sensoriais/efeitos dos fármacos , Células Receptoras Sensoriais/metabolismo , Fatores de TempoRESUMO
Neuropathic pain is a debilitating condition caused by damage to the somatosensory nervous system, such as peripheral nerve injury. The immune system, and in particular the adaptive T cell response, plays a key role in mediating such pain. Regulatory T (Treg) cells are a small subpopulation of inhibitory T cells that prevent autoimmunity, limit immunopathology and maintain immune homeostasis. Here, we investigated the effects of conditional depletion of Treg cells on mechanical allodynia and serum cytokines in mice with chronic constriction injury (CCI) of the sciatic nerve, an animal model of neuropathic pain. We demonstrate that CCI induced the infiltration of small numbers of Treg cells within effected neuronal tissue. Utilising the transgenic DEREG (DEpletion of REGulatory T cells) mice, we confirmed effective depletion of Foxp3+ Treg cells by diphtheria toxin injections. Following CCI we observed a transient, though significant, increase in pain hypersensitivity for Treg-depleted DEREG mice compared to non-Treg-depleted mice. Analysis of systemic cytokine levels demonstrated significant changes in serum cytokine expression profiles. In particular, we observed significant increases in systemic concentration of RANTES, IL-2 and IL-5, and significant decreases in IL-12 and IFN-γ in nerve-injured Treg-depleted DEREG mice. Further analysis indicated a substantial increase in the serum concentration of IL-12p40 as a direct result of Treg cell depletion. These results suggest that depletion of Foxp3+ Treg cells promote nerve injury-induced pain hypersensitivity, partially by inducing altered systemic concentrations of cytokines, which may act to regulate neuropathic pain.
Assuntos
Citocinas/imunologia , Hiperalgesia/imunologia , Traumatismos dos Nervos Periféricos/imunologia , Linfócitos T Reguladores/imunologia , Animais , Western Blotting , Quimiocina CCL5/imunologia , Quimiocina CCL5/metabolismo , Citocinas/metabolismo , Toxina Diftérica/toxicidade , Modelos Animais de Doenças , Citometria de Fluxo , Fatores de Transcrição Forkhead/imunologia , Fatores de Transcrição Forkhead/metabolismo , Hiperalgesia/metabolismo , Hiperalgesia/fisiopatologia , Interferon gama/imunologia , Interferon gama/metabolismo , Interleucina-12/imunologia , Interleucina-12/metabolismo , Interleucina-2/imunologia , Interleucina-2/metabolismo , Interleucina-5/imunologia , Interleucina-5/metabolismo , Depleção Linfocítica/métodos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Microscopia de Fluorescência , Neuralgia/imunologia , Neuralgia/metabolismo , Neuralgia/fisiopatologia , Traumatismos dos Nervos Periféricos/metabolismo , Traumatismos dos Nervos Periféricos/fisiopatologia , Nervo Isquiático/imunologia , Nervo Isquiático/lesões , Nervo Isquiático/fisiopatologia , Índice de Gravidade de Doença , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/metabolismoRESUMO
ABSTRACT: A modern approach for cancer treatment is the use of immunotherapy, and particularly immune checkpoint inhibitors, such as anti-programmed cell death protein 1 (PD-1), alone and in combination with chemotherapy. The PD-1 pathway plays a crucial role in inhibiting immune responses and recently has been shown to modulate neuronal activity. However, the impact of PD-1 blockade on the development of chemotherapy-induced peripheral neuropathy is currently unknown. In this study, we show that C57BL/6 mice treated with the chemotherapeutic drug paclitaxel or cotherapy (paclitaxel and anti-PD-1), but not with anti-PD-1 alone, exhibited increased mechanical sensitivity of the hind paw. Both chemotherapy and immunotherapy caused a reduction in neurite outgrowth of dorsal root ganglion (DRG) explants derived from treated mice, whereas only paclitaxel reduced the neurite outgrowth after direct in vitro treatment. Mice treated with anti-PD-1 or cotherapy exhibited distinct T-cell changes in the lymph nodes and increased T-cell infiltration into the DRG. Mice treated with paclitaxel or cotherapy had increased macrophage presence in the DRG, and all treated groups presented an altered expression of microglia markers in the dorsal horn of the spinal cord. We conclude that combining anti-PD-1 immunotherapy with paclitaxel does not increase the severity of paclitaxel-induced peripheral neuropathy. However, because anti-PD-1 treatment caused significant changes in DRG and spinal cord immunity, caution is warranted when considering immune checkpoint inhibitors therapy in patients with a high risk of developing neuropathy.
Assuntos
Doenças do Sistema Nervoso Periférico , Receptor de Morte Celular Programada 1 , Animais , Gânglios Espinais , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Doenças Neuroinflamatórias , Paclitaxel/toxicidade , Doenças do Sistema Nervoso Periférico/induzido quimicamenteRESUMO
PURPOSE: Haematological toxicities occur in patients receiving oxaliplatin. Mild anaemia (grade 1-2) is a common side effect and approximately 90% of recipients develop measurable spleen enlargement. Although generally asymptomatic, oxaliplatin-induced splenomegaly is independently associated with complications following liver resection for colorectal liver metastasis and separately with poorer patient outcomes. Here, we investigated oxaliplatin-induced haematological toxicities and splenomegaly in mice treated with escalating dosages comparable to those prescribed to colorectal cancer patients. METHODS: Blood was analysed, and smears assessed using Wright-Giemsa staining. Paw coloration was quantified as a marker of anaemia. Spleen weight and morphology were assessed for abnormalities relating to splenomegaly and a flow cytometry and multiplex cytokine array assessment was performed on splenocytes. The liver was assessed for sinusoidal obstructive syndrome. RESULTS: Blood analysis showed dose dependent decreases in white and red blood cell counts, and significant changes in haematological indices. Front and hind paws exhibited dose dependent and dramatic discoloration indicative of anaemia. Spleen weight was significantly increased indicating splenomegaly, and red pulp tissue exhibited substantial dysplasia. Cytokines and chemokines within the spleen were significantly affected with temporal upregulation of IL-6, IL-1α and G-CSF and downregulation of IL-1ß, IL-12p40, MIP-1ß, IL-2 and RANTES. Flow cytometric analysis demonstrated alterations in splenocyte populations, including a significant reduction in CD45+ cells. Histological staining of the liver showed no evidence of sinusoidal obstructive syndrome but there were signs suggestive of extramedullary haematopoiesis. CONCLUSION: Chronic oxaliplatin treatment dose dependently induced haematological toxicity and splenomegaly characterised by numerous physiological and morphological changes, which occurred independently of sinusoidal obstructive syndrome.
Assuntos
Testes Hematológicos , Oxaliplatina/efeitos adversos , Esplenomegalia/induzido quimicamente , Animais , Citocinas/metabolismo , Relação Dose-Resposta a Droga , Fígado/efeitos dos fármacos , Fígado/patologia , Masculino , Camundongos , Tamanho do Órgão/efeitos dos fármacos , Fenótipo , Baço/efeitos dos fármacos , Baço/patologia , Esplenomegalia/metabolismo , Esplenomegalia/patologia , Fatores de TempoRESUMO
Chemotherapy-induced peripheral neuropathy (CIPN) is a severe and debilitating adverse effect of cancer therapy that results from treatment with neurotoxic agents. Although chemotherapy treatment has been shown to inhibit neurite outgrowth from dorsal root ganglion (DRG) neurons in vitro, evidence for this effect in vivo is lacking. In this study, we investigated whether chemotherapy treatment in mice alters the capacity for axonal outgrowth from ex vivo cultured DRG explants. Using a neurite outgrowth assay, we demonstrated that DRG explants isolated at day 30 from mice treated with 6 cycles of paclitaxel, or 12 cycles of oxaliplatin showed a significant reduction in neurite outgrowth as compared to DRG explants from control vehicle-treated mice. DRGs that were isolated at day 90 showed recovery of the neurite outgrowth, and no significant differences were detected in comparison to vehicle controls. These results are corroborated with an in vitro model, whereby direct application of oxaliplatin and paclitaxel dose-dependently reduced neurite outgrowth of DRG explants. In conclusion, our results show that the effect of paclitaxel and oxaliplatin on the structural plasticity of DRG is retained ex vivo (for at least 30 days) and suggest the use of DRG explants derived from chemotherapy-treated mice as an efficient method to investigate the mechanisms underlying CIPN and test for possible therapeutic targets.
Assuntos
Antineoplásicos/farmacologia , Gânglios Espinais/efeitos dos fármacos , Crescimento Neuronal/efeitos dos fármacos , Oxaliplatina/farmacologia , Paclitaxel/farmacologia , Animais , Antineoplásicos Fitogênicos/farmacologia , Células Cultivadas , Relação Dose-Resposta a Droga , Gânglios Espinais/fisiologia , Masculino , Camundongos Endogâmicos BALB C , Neuritos/efeitos dos fármacos , Neuritos/fisiologia , Plasticidade Neuronal/efeitos dos fármacosRESUMO
BACKGROUND: Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system (CNS). Of the plethora of motor and sensory disturbances experienced by sufferers, neuropathic pain is a highly prevalent and debilitating symptom, and at present remains extremely difficult to treat. Common forms of neuropathic pain seen in MS patients include central neuropathic pain, Lhermitte's phenomenon and trigeminal neuralgia, which are all speculated to arise from specific patterns of lesion formation. OBJECTIVE: Efficacious pharmacological interventions for the treatment of neuropathic pain associated with MS are lacking, and have been largely informed by drug trials in peripheral neuropathies and spinal cord injury. METHOD/RESULTS: Neuropathic pain in MS is inadequately relieved by conventional analgesics, and first-line therapies are generally comprised of anti-depressive and anti-convulsive drugs. A range of alternatives have been proposed and tested with variable success, including cannabinoids and certain opioid analgesics. Animals with experimental autoimmune encephalomyelitis (EAE), an autoimmune model of MS, also exhibit neuropathic pain symptoms. CONCLUSION: Studies aimed at understanding the mechanisms underlying EAE-induced neuropathic pain and investigating the efficacy of novel pharmacological interventions at the animal level offer an exciting area of future research, and may inform future therapeutic options for MS-associated neuropathic pain.
Assuntos
Anticonvulsivantes/uso terapêutico , Antidepressivos/uso terapêutico , Encefalomielite Autoimune Experimental/tratamento farmacológico , Esclerose Múltipla/tratamento farmacológico , Neuralgia/tratamento farmacológico , Animais , Anticonvulsivantes/química , Antidepressivos/química , HumanosRESUMO
Connexin43 (Cx43) hemichannels in spinal cord astrocytes are implicated in the maintenance of neuropathic pain following peripheral nerve injury. Peptide5 is a Cx43 mimetic peptide that blocks hemichannels. In this study, we investigated the effects of spinal delivery of Peptide5 on mechanical pain hypersensitivity in two mouse models of neuropathic pain, peripheral nerve injury and chemotherapy-induced peripheral neuropathy (CIPN). We demonstrated that 10days following a chronic constriction injury (CCI) of the sciatic nerve, Cx43 expression, co-localised predominantly with astrocytes, was increased in the ipsilateral L3-L5 lumbar spinal cord. An intrathecal injection of Peptide5 into nerve-injured mice, on day 10 when pain was well-established, caused significant improvement in mechanical pain hypersensitivity 8h after injection. Peptide5 treatment resulted in significantly reduced Cx43, and microglial and astrocyte activity in the dorsal horn of the spinal cord, as compared to control saline-treated CCI mice. Further in vitro investigations on primary astrocyte cultures showed that 1h pre-treatment with Peptide5 significantly reduced adenosine triphosphate (ATP) release in response to extracellular calcium depletion. Since ATP is a known activator of the NOD-like receptor protein 3 (NLRP3) inflammasome complex, a key mediator of neuroinflammation, we examined the effects of Peptide5 treatment on NLRP3 inflammasome expression. We found that NLRP3, its adaptor apoptosis-associated spec-like protein (ASC) and caspase-1 protein were increased in the ipsilateral spinal cord of CCI mice and reduced to naïve levels following Peptide5 treatment. In the models of oxaliplatin- and paclitaxel-induced peripheral neuropathy, treatment with Peptide5 had no effect on mechanical pain hypersensitivity. Interestingly, in these CIPN models, although spinal Cx43 expression was significantly increased at day 13 following chemotherapy, NLRP3 expression was not altered. These results suggest that the analgesic effect of Peptide5 is specifically achieved by reducing NLRP3 expression. Together, our findings demonstrate that blocking Cx43 hemichannels with Peptide5 after nerve injury attenuates mechanical pain hypersensitivity by specifically targeting the NLRP3 inflammasome in the spinal cord.
Assuntos
Materiais Biomiméticos/administração & dosagem , Conexina 43/administração & dosagem , Hiperalgesia/tratamento farmacológico , Proteína 3 que Contém Domínio de Pirina da Família NLR/antagonistas & inibidores , Neuralgia/tratamento farmacológico , Fragmentos de Peptídeos/administração & dosagem , Animais , Hiperalgesia/metabolismo , Inflamassomos/antagonistas & inibidores , Inflamassomos/metabolismo , Injeções Espinhais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Neuralgia/metabolismo , Resultado do TratamentoRESUMO
Chemotherapy-induced peripheral neuropathy (CIPN) and associated neuropathic pain is a debilitating adverse effect of cancer treatment. Current understanding of the mechanisms underpinning CIPN is limited and there are no effective treatment strategies. In this study, we treated male C57BL/6J mice with 4 cycles of either Paclitaxel (PTX) or Oxaliplatin (OXA) over a week and tested pain hypersensitivity and changes in peripheral immune responses and neuroinflammation on days 7 and 13 post 1st injection. We found that both PTX and OXA caused significant mechanical allodynia. In the periphery, PTX and OXA significantly increased circulating CD4+ and CD8+ T-cell populations. OXA caused a significant increase in the percentage of interleukin-4+ lymphocytes in the spleen and significant down-regulation of regulatory T (T-reg) cells in the inguinal lymph nodes. However, conditional depletion of T-reg cells in OXA-treated transgenic DEREG mice had no additional effect on pain sensitivity. Furthermore, there was no leukocyte infiltration into the nervous system of OXA- or PTX-treated mice. In the peripheral nervous system, PTX induced expression of the neuronal injury marker activating transcription factor-3 in IB4+ and NF200+ sensory neurons as well as an increase in the chemokines CCL2 and CCL3 in the lumbar dorsal root ganglion. In the central nervous system, PTX induced significant astrocyte activation in the spinal cord dorsal horn, and both PTX and OXA caused reduction of P2ry12+ homeostatic microglia, with no measurable changes in IBA-1+ microglia/macrophages in the dorsal and ventral horns. We also found that PTX induced up-regulation of several inflammatory cytokines and chemokines (TNF-α, IFN-γ, CCL11, CCL4, CCL3, IL-12p70 and GM-CSF) in the spinal cord. Overall, these findings suggest that PTX and OXA cause distinct pathological changes in the periphery and nervous system, which may contribute to chemotherapy-induced neuropathic pain.
Assuntos
Antineoplásicos/efeitos adversos , Gânglios Espinais/efeitos dos fármacos , Hiperalgesia/imunologia , Neuralgia/imunologia , Compostos Organoplatínicos/efeitos adversos , Paclitaxel/efeitos adversos , Medula Espinal/efeitos dos fármacos , Fator 3 Ativador da Transcrição/genética , Fator 3 Ativador da Transcrição/imunologia , Animais , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Quimiocina CCL2/genética , Quimiocina CCL2/imunologia , Quimiocina CCL3/genética , Quimiocina CCL3/imunologia , Gânglios Espinais/imunologia , Gânglios Espinais/patologia , Expressão Gênica , Hiperalgesia/induzido quimicamente , Hiperalgesia/genética , Hiperalgesia/patologia , Linfonodos/efeitos dos fármacos , Linfonodos/imunologia , Linfonodos/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Microglia/efeitos dos fármacos , Microglia/imunologia , Microglia/patologia , Neuralgia/induzido quimicamente , Neuralgia/genética , Neuralgia/patologia , Proteínas de Neurofilamentos/genética , Proteínas de Neurofilamentos/imunologia , Oxaliplatina , Receptores Purinérgicos P2Y12/genética , Receptores Purinérgicos P2Y12/imunologia , Células Receptoras Sensoriais/efeitos dos fármacos , Células Receptoras Sensoriais/imunologia , Células Receptoras Sensoriais/patologia , Medula Espinal/imunologia , Medula Espinal/patologia , Baço/efeitos dos fármacos , Baço/imunologia , Baço/patologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/patologiaRESUMO
Chemotherapy-induced peripheral neuropathy (CIPN) and associated neuropathic pain are challenging complications of cancer treatment. Many of the major classes of chemotherapeutics can cause neurotoxicity and significantly modulate the immune system. There is ongoing investigation regarding whether reciprocal crosstalk between the nervous and immune systems occurs and, indeed, contributes to neuropathic pain during treatment with chemotherapeutics. An emerging concept is that neuroinflammation is one of the major mechanisms underlying CIPN. Here, we discuss recent findings, which provide insight into this complex process of neuroimmune interactions. Findings show limited infiltration of leukocytes into the nervous system of CIPN animals and varying degrees of peripheral and central glial activation depending on the chemotherapeutic drug, dose, schedule, and timing. Most evidence suggests an increase in pro-inflammatory cytokine expression and changes in immune signalling pathways. There is, however, limited evidence available from human studies and it remains unclear whether neuroinflammatory responses are the cause of neuropathy or a bystander effect of the chemotherapy treatment.
Assuntos
Imunidade Adaptativa/efeitos dos fármacos , Antineoplásicos/efeitos adversos , Imunidade Inata/efeitos dos fármacos , Neuralgia/induzido quimicamente , Doenças do Sistema Nervoso Periférico/induzido quimicamente , Animais , Quimiocinas/metabolismo , Citocinas/metabolismo , Humanos , Neuralgia/imunologia , Neuroglia/efeitos dos fármacos , Síndromes Neurotóxicas/etiologia , Doenças do Sistema Nervoso Periférico/imunologia , Transdução de Sinais/efeitos dos fármacosRESUMO
Pain is a widespread and debilitating symptom of multiple sclerosis (MS), a chronic inflammatory demyelinating disease of the central nervous system. Although central neuroinflammation and demyelination have been implicated in MS-related pain, the contribution of peripheral and central mechanisms during different phases of the disease remains unclear. In this study, we used the animal model experimental autoimmune encephalomyelitis (EAE) to examine both stimulus-evoked and spontaneous pain behaviors, and neuroinflammatory changes, over the course of chronic disease. We found that mechanical allodynia of the hind paw preceded the onset of clinical EAE but was unmeasurable at clinical peak. This mechanical hypersensitivity coincided with increased microglial activation confined to the dorsal horn of the spinal cord. The development of facial mechanical allodynia also emerged in preclinical EAE, persisted at the clinical peak, and corresponded with pathology of the peripheral trigeminal afferent pathway. This included T cell infiltration, which arose prior to overt central lesion formation and specific damage to myelinated neurons during the clinical peak. Measurement of spontaneous pain using the mouse grimace scale, a facial expression-based coding system, showed increased facial grimacing in mice with EAE during clinical disease. This was associated with multiple peripheral and central neuroinflammatory changes including a decrease in myelinating oligodendrocytes, increased T cell infiltration, and macrophage/microglia and astrocyte activation. Overall, these findings suggest that different pathological mechanisms may underlie stimulus-evoked and spontaneous pain in EAE, and that these behaviors predominate in unique stages of the disease.