Human Intravenous Immunoglobulin Alleviates Neuropathic Symptoms in a Rat Model of Paclitaxel-Induced Peripheral Neurotoxicity.

The onset of chemotherapy-induced peripheral neurotoxicity (CIPN) is a leading cause of the dose reduction or discontinuation of cancer treatment due to sensory symptoms. Paclitaxel (PTX) can cause painful peripheral neuropathy, with a negative impact on cancer survivors' quality of life. While recent studies have shown that neuroinflammation is involved in PTX-induced peripheral neurotoxicity (PIPN), the pathophysiology of this disabling side effect remains largely unclear and no effective therapies are available. Therefore, here we investigated the effects of human intravenous immunoglobulin (IVIg) on a PIPN rat model. PTX-treated rats showed mechanical allodynia and neurophysiological alterations consistent with a severe sensory axonal polyneuropathy. In addition, morphological evaluation showed a reduction of intra-epidermal nerve fiber (IENF) density and evidenced axonopathy with macrophage infiltration, which was more prominent in the distal segment of caudal nerves. Three weeks after the last PTX injection, mechanical allodynia was still present in PTX-treated rats, while the full recovery in the group of animals co-treated with IVIg was observed. At the pathological level, this behavioral result was paralleled by prevention of the reduction in IENF density induced by PTX in IVIg co-treated rats. These results suggest that the immunomodulating effect of IVIg co-treatment can alleviate PIPN neurotoxic manifestations, probably through a partial reduction of neuroinflammation.

Global Transcriptomic Profile of Dorsal Root Ganglion and Physiological Correlates of Cisplatin-Induced Peripheral Neuropathy.

BACKGROUND: Multiple cell signaling pathways are implicated in the development, progression, and persistence of cisplatin-induced peripheral neuropathy. Although advances have been made in terms of understanding specific neurotoxic mechanisms, there are few predictive factors identified that can help inform the clinician approach to symptom prevention or management. OBJECTIVE: We investigate the differential sensitivity to cisplatin-induced peripheral neuropathy and examine the contribution of dorsal root ganglion (DRG) transcriptional profiles across two inbred strains of mice. METHODS: Cisplatin (4 mg/kg intraperitoneal or vehicle control) was administered twice a week for 4 weeks to adult female C57BL/6J and A/J mice-the C57BL/6J strain of mice characterized by a robust mechanical allodynia and the A/J with a mild largely resistant allodynia phenotype. Peripheral nerve conduction velocities (NCVs), electrophysiological evaluation of wide dynamic range (WDR) neurons, morphological examination of DRG neurons, and microarray analysis of spinal cord tissues were compared across the 4 weeks. RESULTS: The A/J strain presents with an early, mild nocifensive response to cisplatin with reduced neuronal activity in WDR neurons and small changes in cross-sectional nucleus size in DRG neurons at 4 weeks. The more nocifensive-sensitive C57BL/6J strain presents with no early changes in WDR neuron responsiveness; however, there were significant changes in DRG size. Both strains demonstrate a drop in NCV after 4 weeks of treatment, with the greatest reduction present in the A/J strain. Transcriptome data implicate neuroimmune modulation in the differential response to cisplatin in the DRGs of A/J and C57BL/6J mice. DISCUSSION: Nocifensive responses in both strains implicate involvement of small myelinated and unmyelinated fibers in neurotoxic cisplatin response, whereas reductions in NCV reflect involvement of the largest myelinated fibers in the peripheral nerves. Microarray data analysis identifies neuropathy-relevant gene sets with differential activation of pathways, suggesting a role for antigen presentation in the differential neurotoxic response to cisplatin across strains. Further research is indicated to determine the relative contributions of each of these potential pathological mechanisms to both the neurotoxic response to cisplatin and to the potential for targeted therapy.

High-dose intravenous immunoglobulins reduce nerve macrophage infiltration and the severity of bortezomib-induced peripheral neurotoxicity in rats.

BACKGROUND: Chemotherapy-induced peripheral neurotoxicity (CIPN) is a severe adverse effect in patients receiving antitumor agents, and no effective treatment is available. Although the mechanisms responsible for the development of CIPN are poorly understood, recent findings make neuroinflammation an attractive target to be investigated, particularly when neuropathic pain is a prominent feature such as after bortezomib administration. The aim of our study was to evaluate the effect of intravenous immunoglobulins (IVIg) delivery in chronic CIPN. The related neuro-immune aspects were investigated in a well-characterized rat model of bortezomib-induced peripheral neurotoxicity (BIPN). METHODS: After determination of a suitable schedule based on a preliminary pharmacokinetic pilot study, female Wistar rats were treated with IVIg 1 g/kg every 2 weeks. IVIg treatment was started at the beginning of bortezomib administration ("preventive" schedule), or once BIPN was already ensued after 4 weeks of treatment ("therapeutic" schedule). Neurophysiological and behavioral studies were performed to assess the extent of painful peripheral neurotoxicity induced by bortezomib, and these functional assessments were completed by pathologic examination of peripheral nerves and intraepidermal nerve fiber quantification (IENF). The role of the innate immune response in BIPN was investigated by immunochemistry characterization of macrophage infiltration in peripheral nerves. RESULTS: Both schedules of IVIg administration were able to significantly reduce bortezomib-induced heat and mechanical allodynia. Although these changes were not evidenced at the neurophysiological examination of peripheral nerves, they behavioral effects were paralleled in the animals treated with the preventive schedule by reduced axonopathy in peripheral nerves and significant protection from loss of IENF. Moreover, IVIg administration was very effective in reducing infiltration in peripheral nerves of macrophages with the M1, pro-inflammatory phenotype. CONCLUSION: Our results suggest a prominent role of neuroinflammation in BIPN and that IVIg might be considered as a possible safe and effective therapeutic option preventing M1 macrophage infiltration. However, since neuropathic pain is frequent also in other CIPN types, it also indicates the need for further investigation in other forms of CIPN.

Islet transplantation and insulin administration relieve long-term complications and rescue the residual endogenous pancreatic ß cells.

Islet transplantation is a poorly investigated long-term strategy for insulin replacement and for treatment of complications in patients with diabetes. We investigated whether islet transplantation and insulin treatment can relieve diabetic neuropathy and rescue the residual endogenous pancreatic ß cells. We used a multimodal approach, with five groups of Sprague-Dawley rats studied for 8 months: control rats, diabetic rats, insulin-treated diabetic rats with moderate or mild hyperglycemia, and diabetic rats transplanted with microencapsulated islets. Islet transplantation normalized glycemia and increased body and muscle weight; it was also effective in reducing proteinuria and altered liver function. Transplantation significantly improved tail nerve conduction velocity, Na(+)-K(+)-ATPase activity, and morphological alterations in the sciatic nerve as evidenced by decrease in g-ratio; it also restored thermal and ameliorated mechanical nociceptive thresholds. Morphometric analysis of pancreas indicated a significant ß-cell volume increase in transplanted rats, compared with mildly and moderately hyperglycemic rats. Thus, allogeneic islet transplantation had a positive systemic effect in diabetic rats and induced regression of the established neuropathy and restitution of the typical characteristics of the islets. These findings strongly reinforce the need for improving glycemic control, not only to reverse established diabetic complications but also to improve ß-cell status in diabetic pancreas.

Multimodal Comparison of Diabetic Neuropathy in Aged Streptozotocin-Treated Sprague-Dawley and Zucker Diabetic Fatty Rats.

The development and progression of diabetic polyneuropathy (DPN) are due to multiple mechanisms. The creation of reliable animal models of DPN has been challenging and this issue has not yet been solved. However, despite some recognized differences from humans, most of the current knowledge on the pathogenesis of DPN relies on results achieved using rodent animal models. The simplest experimental DPN model reproduces type 1 diabetes, induced by massive chemical destruction of pancreatic beta cells with streptozotocin (STZ). Spontaneous/transgenic models of diabetes are less frequently used, mostly because they are less predictable in clinical course, more expensive, and require a variable time to achieve homogeneous metabolic conditions. Among them, Zucker diabetic fatty (ZDF) rats represent a typical type 2 diabetes model. Both STZ-induced and ZDF rats have been extensively used, but only very few studies have compared the long-term similarities and differences existing between these two models. Moreover, inconsistencies have been reported regarding several aspects of short-term in vivo studies using these models. In this study, we compared the long-term course of DPN in STZ-treated Sprague-Dawley and ZDF rats with a multimodal set of readout measures.

Systems Pharmacology Modeling Identifies a Novel Treatment Strategy for Bortezomib-Induced Neuropathic Pain.

Chemotherapy-induced peripheral neurotoxicity is a common dose-limiting side effect of several cancer chemotherapeutic agents, and no effective therapies exist. Here we constructed a systems pharmacology model of intracellular signaling in peripheral neurons to identify novel drug targets for preventing peripheral neuropathy associated with proteasome inhibitors. Model predictions suggested the combinatorial inhibition of TNFα, NMDA receptors, and reactive oxygen species should prevent proteasome inhibitor-induced neuronal apoptosis. Dexanabinol, an inhibitor of all three targets, partially restored bortezomib-induced reduction of proximal action potential amplitude and distal nerve conduction velocity in vitro and prevented bortezomib-induced mechanical allodynia and thermal hyperalgesia in rats, including a partial recovery of intraepidermal nerve fiber density. Dexanabinol failed to restore bortezomib-induced decreases in electrophysiological endpoints in rats, and it did not compromise bortezomib anti-cancer effects in U266 multiple myeloma cells and a murine xenograft model. Owing to its favorable safety profile in humans and preclinical efficacy, dexanabinol might represent a treatment option for bortezomib-induced neuropathic pain.

Topiramate prevents oxaliplatin-related axonal hyperexcitability and oxaliplatin induced peripheral neurotoxicity.

Oxaliplatin (OHP) Induced Peripheral Neurotoxicity (OIPN) is one of the dose-limiting toxicities of the drug and these adverse effects limit cancer therapy with L-OHP, used for colorectal cancer treatment. Acute neurotoxicity consists of symptoms that are the hallmarks of a transient axonal hyperexcitability; chronic neurotoxicity has a clinical picture compatible with a length-dependent sensory neuropathy. Acute OIPN pathogenesis has been linked to sodium voltage-operated channels (Na + VOC) dysfunction and it has been advocated as a possible predisposing factor to chronic neurotoxicity. We tested if topiramate (TPM), a well-known Na + VOC modulator, was able to modify acute as well as chronic OIPN. The project was divided into two parts. In Experiment 1 we tested by means of Nerve Excitability Testing (NET) a cohort of female Wistar rats to assess TPM effects after a single OHP administration (5 mg/kg, iv). In Experiment 2 we assessed TPM effects after chronic OHP treatment (5 mg/kg, 2qw4ws, iv) using NET, nerve conduction studies (NCS), behavioral tests and neuropathology (caudal nerve morphometry and morphology and Intraepidermal Nerve Fiber [IENF] density). In Experiment 1 TPM was able to prevent OHP effects on Na + VOC: OHP treatment induced a highly significant reduction of the sensory nerve's threshold, during the superexcitability period (p-value = 0.008), whereas TPM co-administration prevented this effect. In Experiment 2 we verified that TPM was able to prevent not only acute phenomena, but also to completely prevent chronic OIPN. This latter observation was supported by a multimodal approach: in fact, only OHP group showed altered findings compared to CTRL group at a neurophysiological (proximal caudal nerve sensory nerve action potential [SNAP] amplitude, p-value = 0.001; distal caudal nerve SNAP amplitude, p-value<0.001, distal caudal nerve sensory conduction velocity, p-value = 0.04), behavioral (mechanical threshold, p-value 0.003) and neuropathological levels (caudal nerve fibers density, p-value 0.001; IENF density, p-value <0.001). Our data show that TPM is a promising drug to prevent both acute and chronic OIPN. These findings have a high translational potential, since they were obtained using outcome measures that match clinical practice and TPM is already approved for clinical use being free from detrimental interaction with OHP anticancer properties.

Calmangafodipir Reduces Sensory Alterations and Prevents Intraepidermal Nerve Fibers Loss in a Mouse Model of Oxaliplatin Induced Peripheral Neurotoxicity.

Oxaliplatin (OHP) is an antineoplastic compound able to induce peripheral neurotoxicity. Oxidative stress has been suggested to be a key factor in the development of OHP-related peripheral neurotoxicity. Mangafodipir, a contrast agent possessing mitochondrial superoxide dismutase (MnSOD)-mimetic activity, has been tested as a cytoprotector in chemotherapy-induced peripheral neurotoxicity (CIPN). Calmangafodipir (PledOx®) has even better therapeutic activity. We investigated a BALB/c mouse model of OHP-related CIPN and the effects of the pre-treatment of calmangafodipir (2.5, 5, or 10 mg/kg intravenously) on sensory perception, and we performed a pathological study on skin biopsies to assess intraepidermal nerve fiber (IENF) density. At the end of the treatments, OHP alone or in pre-treatment with calmangafodipir 2.5 and 10 mg/kg, induced mechanical allodynia and cold thermal hyperalgesia, but calmangafodipir 5 mg/kg prevented these effects. Accordingly, OHP alone or in pre-treatment with calmangafodipir 2.5 and 10 mg/kg, induced a significant reduction in IENF density, but calmangafodipir 5 mg/kg prevented this reduction. These results confirm a protective effect of calmangafodipir against OHP-induced small fiber neuropathy. Interestingly, these results are in agreement with previous observations suggesting a U-shaped effect of calmangafodipir, with the 10 mg/kg dose less effective than the lower doses.

The relevance of multimodal assessment in experimental oxaliplatin-induced peripheral neurotoxicity.

Chemotherapy-induced peripheral neurotoxicity represents one of the most relevant dose-limiting side effects that can affect cancer patients treated with the common antineoplastic agents. Since the severity of neurotoxicity often leads to dose reduction or early cessation of chemotherapy, the investigation of molecular mechanisms underlying chemotherapy-induced peripheral neurotoxicity is an urgent clinical need in order to better understand its physiopathology and find effective strategies for neuroprotection. Several in vivo preclinical models of chemotherapy-induced peripheral neurotoxicity have been developed but a great variability in mouse strain, dose, route of administration of the drug, treatment schedule and assessment of neurotoxicity is observed between the different published studies making difficult the comparison and interpretation of their results. In many of these studies only behavioural tests are used as outcome measures, while possible neurophysiological and neuropathological changes are not evaluated. In this study, focused on experimental oxaliplatin-induced peripheral neurotoxicity, we reproduced and compared four mouse models with very different drug dose (low or high dose-intensity) and treatment schedules (short or long-term treatment), selected from the literature. Using a multimodal assessment based on behavioural, neurophysiological and neuropathological methods, we evidenced remarkable differences in the results obtained in the selected animal models. This work suggests the importance of a multimodal approach including extensive pathological investigation to confirm the behavioural results.

Reply to a Comment Paper on the Published Paper by Canta, A. et al: "Calmangafodipir Reduces Sensory Alterations and Prevents Intraepidermal Nerve Fibers Loss in a Mouse Model of Oxaliplatin Induced Peripheral Neurotoxicity"-Antioxidants 2020, 9, 594.

The comments sent by Stehr, Lundstom and Karlsson with reference to our article "Calmangafodipir reduces sensory alterations and prevents intraepidermal nerve fiber loss in a mouse model of oxaliplatin-induced peripheral neurotoxicity" are very interesting, since they suggest possible mechanisms of action of the compound, which might contribute to its protective action [...].

Experimental epothilone B neurotoxicity: results of in vitro and in vivo studies.

Epothilones are a novel class of microtubule-targeting anticancer agents that are neurotoxic. In this study, we investigated the epothilone B toxic effect in vitro and we characterized in vivo the general and neurological side effects of epothilone B administration in Wistar and Fischer rats. The in vitro experiments made it possible to explore a wide concentration range (0.1 nM-1 muM) and evidenced a dose-dependent effect of epothilone B exposure on neuron neurite elongation. This dose-dependent neurotoxic effect was confirmed in both in vivo studies performed on two different rat strains at the neurophysiological, behavioral and pathological levels in the dose range 0.25-1.5 mg/kg iv weekly x 4 weeks and tubulin hyper-polymerization was demonstrated in sciatic nerve specimens. These are the first studies of the neurological effects of epothilone B and they can provide a basis for extending pre-clinical investigation to other members of the epothilone family.

Actively induced EAE in Lewis rats: characterization of spleen and spinal cord infiltrating lymphocytes by flow cytometry during the course of the disease.

Actively induced Lewis rat Experimental Autoimmune Encephalomyelitis (EAE) is a highly reproducible model for portraying the acute phase of multiple sclerosis. Our aim was to get more information about this model by means of flow cytometry looking at potential markers for tracing new treatments' efficacy. Thus we characterized the changes occurring in encephalitogenic TCR Vbeta8.2(+) frequency and the adhesion molecule alpha4 integrin expression in both spleen and spinal cord T cells. The increase in both these parameters was observed only in spinal cord infiltrating T cells while relevant changes in spleen cell composition were observed as early as disease onset.

Expression and distribution of 'high affinity' glutamate transporters GLT1, GLAST, EAAC1 and of GCPII in the rat peripheral nervous system.

l-Glutamate is one of the major excitatory neurotransmitters in the mammalian central nervous system, but recently it has been shown to have a role also in the transduction of sensory input at the periphery, and in particular in the nociceptive pathway. An excess of glutamate is implicated in cases of peripheral neuropathies as well. Conventional therapeutic approaches for treating these diseases have focused on blocking glutamate receptors with small molecules or on reducing its synthesis of the receptors through the inhibition of glutamate carboxypeptidase II (GCPII), the enzyme that generates glutamate. In vivo studies have demonstrated that the pharmacological inhibition of GCPII can either prevent or treat the peripheral nerve changes in both BB/Wor and chemically induced diabetes in rats. In this study, we characterized the expression and distribution of glutamate transporters GLT1, GLAST, EAAC1 and of the enzyme GCPII in the peripheral nervous system of female Wistar rats. Immunoblotting results demonstrated that all glutamate transporters and GCPII are present in dorsal root ganglia (DRG) and the sciatic nerve. Immunofluorescence localization studies revealed that both DRG and sciatic nerves were immunopositive for all glutamate transporters and for GCPII. In DRG, satellite cells were positive for GLT1 and GCPII, whereas sensory neurons were positive for EAAC1. GLAST was localized in both neurons and satellite cells. In the sciatic nerve, GLT1 and GCPII were expressed in the cytoplasm of Schwann cells, whereas GLAST and EAAC1 stained the myelin layer. Our results give for the first time a complete characterization of the glutamate transporter system in the peripheral nervous system. Therefore, they are important both for understanding glutamatergic signalling in the PNS and for establishing new strategies to treat peripheral neuropathies.

Valproate protective effects on cisplatin-induced peripheral neuropathy: an in vitro and in vivo study.

BACKGROUND: Antineoplastic drugs, such as cisplatin (CDDP), induce disabling peripheral neuropathies, representing a hindrance to effective cancer treatments. The exact pathogenesis of CDDP-induced neuropathy is not yet understood, and the dysregulation of gene expression has been proposed. Valproate (VPA) is an antiepileptic drug recently discovered to remodel gene expression, with hypothetically putative neuroprotective effects. MATERIALS AND METHODS: VPA was tested in both, in vitro and in vivo models of CDDP-neurotoxicity. RESULTS: VPA administered in combination with CDDP promoted dorsal root ganglia (DRG) neurons survival. Moreover, this treatment induced in Wistar rats an improvement of body weight, sensory nerve conduction velocity, and DRG morphometric analysis. In contrast, VPA was not able to rescue CDDP pre-treated rats. CONCLUSION: When used in combination with CDDP, VPA displays a protective action against neuropathy, in our models, suggesting possible future clinical applications.

Cisplatin-induced peripheral neuropathy: neuroprotection by erythropoietin without affecting tumour growth.

This study examined the dose-dependent efficacy of erythropoietin (EPO) for preventing and/or treating cisplatin (CDDP) induced peripheral neurotoxicity (CINP), and its influence on tumour treatment and growth. Rats received eight intraperitoneal (ip) injections of 2 mg/kg CDDP twice weekly. EPO co-administered (50 or 10 microg/kg ip, three times/week) had a dose-dependent effect, partially preventing CINP, but 0.5 microg/kg ip was not effective. The neuroprotective effect lasted at least 5 weeks after the last dose of EPO and CDDP. In addition, EPO (50 microg/kg ip three times/week) after the last injection of CDDP still induced a significant recovery of CINP. In a separate experiment in rats bearing mammary carcinoma EPO treatment (50 microg/kg ip) given concurrently with CDDP (1.0 and 1.5 mg/kg twice a week for four weeks) was neuroprotective without influencing the effectiveness of the treatment or tumour growth. EPO thus appears to be an effective neuroprotectant that does not interfere with tumour treatment.

Protective effect of erythropoietin and its carbamylated derivative in experimental Cisplatin peripheral neurotoxicity.

PURPOSE: Antineoplastic drugs, such as cisplatin (CDDP), are severely neurotoxic, causing disabling peripheral neuropathies with clinical signs known as chemotherapy-induced peripheral neurotoxicity. Cotreatment with neuroprotective agents and CDDP has been proposed for preventing or reversing the neuropathy. Erythropoietin given systemically has a wide range of neuroprotective actions in animal models of central and peripheral nervous system damage. However, the erythropoietic action is a potential cause of side effects if erythropoietin is used for neuroprotection. We have successfully identified derivatives of erythropoietin, including carbamylated erythropoietin, which do not raise the hematocrit but retain the neuroprotective action exerted by erythropoietin. EXPERIMENTAL DESIGN: We have developed previously an experimental chemotherapy-induced peripheral neurotoxicity that closely resembles CDDP neurotoxicity in humans. The present study compared the effects of erythropoietin and carbamylated erythropoietin (50 microg/kg/d thrice weekly) on CDDP (2 mg/kg/d i.p. twice weekly for 4 weeks) neurotoxicity in vivo. RESULTS: CDDP given to Wistar rats significantly lowered their growth rate (P < 0.05), with slower sensory nerve conduction velocity (P < 0.001) and reduced intraepidermal nerve fibers density (P < 0.001 versus controls). Coadministration of CDDP and erythropoietin or carbamylated erythropoietin partially but significantly prevented the sensory nerve conduction velocity reduction. Both molecules preserved intraepidermal nerve fiber density, thus confirming their neuroprotective effect at the pathologic level. The protective effects were not associated with any difference in platinum concentration in dorsal root ganglia, sciatic nerve, or kidney specimens. CONCLUSIONS: These results widen the spectrum of possible use of erythropoietin and carbamylated erythropoietin as neuroprotectant drugs, strongly supporting their effectiveness.

Therapeutic potential of Mesenchymal Stem Cells for the treatment of diabetic peripheral neuropathy.

Type-1 Diabetes is generally treated with exogenous insulin administration. Despite treatment, a very common long term consequence of diabetes is the development of a disabling and painful peripheral neuropathy. The transplantation of pancreatic islets is an advanced alternative therapeutic approach, but its clinical application is still very limited, mainly because of the great number of islets required to complete the procedure and of their short-term survival. An intriguing method to improve the performance of pancreatic islets transplantation is the co-transplantation of Mesenchymal Stem Cells (MSCs), adult stem cells already known to support the survival of different cellular populations. In this proof-of-concept study, we demonstrated using an in vivo model of diabetes, the ability of allogenic MSCs to reduce the number of pancreatic islets necessary to achieve glycemic control in diabetic rats, and overall their positive effect on diabetic neuropathy, with the reduction of all the neuropathic signs showed after disease induction. The cutback of the pancreatic islet number required to control glycemia and the regression of the painful neuropathy make MSC co-transplantation a very promising tool to improve the clinical feasibility of pancreatic islet transplantation for diabetes treatment.

Toward the identification of neuroprotective agents: g-scale synthesis, pharmacokinetic evaluation and CNS distribution of (R)-RC-33, a promising SIGMA1 receptor agonist.

AIM: Nowadays, there is a great interest in the therapeutic potential of sigma1 receptor ligands for treating different CNS pathologies. Our previous investigations led to identify (R)-RC-33 as a potent and selective S1R agonist. RESULTS: Herein, we report the gram-scale synthesis, pharmacokinetic profile and CNS distribution of (R)-RC-33 in the mouse to determine the most suitable dosage schedule for in vivo administration. For comparative purposes, the same experiments were also performed with PRE-084, the most widely used S1R agonist commonly in pharmacological experiments. DISCUSSION: (R)-RC-33 shows a similar pharmacokinetic profile and a better CNS distribution when compared with PRE-084. CONCLUSION: (R)-RC-33 may be a promising candidate for in vivo studies in animal models of neurodegenerative diseases.

Age-related changes in the function and structure of the peripheral sensory pathway in mice.

This study is aimed at describing the changes occurring in the entire peripheral nervous system sensory pathway along a 2-year observation period in a cohort of C57BL/6 mice. The neurophysiological studies evidenced significant differences in the selected time points corresponding to childhood, young adulthood, adulthood, and aging (i.e., 1, 7, 15, and 25 months of age), with a parabolic course as function of time. The pathological assessment allowed to demonstrate signs of age-related changes since the age of 7 months, with a remarkable increase in both peripheral nerves and dorsal root ganglia at the subsequent time points. These changes were mainly in the myelin sheaths, as also confirmed by the Rotating-Polarization Coherent-Anti-stokes-Raman-scattering microscopy analysis. Evident changes were also present at the morphometric analysis performed on the peripheral nerves, dorsal root ganglia neurons, and skin biopsies. This extensive, multimodal characterization of the peripheral nervous system changes in aging provides the background for future mechanistic studies allowing the selection of the most appropriate time points and readouts according to the investigation aims.

Effects of pixantrone on immune-cell function in the course of acute rat experimental allergic encephalomyelitis.

Pixantrone is an immunesuppressor similar to mitoxantrone but with lower cardiotoxicity. We evaluated the effect of pixantrone on B cells and lymphomononuclear cells in the course of acute EAE. Pixantrone reduced the number of B cells and suppressed myelin basic protein (MBP) specific IgG production. In vitro, pixantrone induced apoptosis of rat B lymphocytes in a way similar to mitoxantrone. In addition, pixantrone inhibited antigen specific and mitogen induced lymphomononuclear cell proliferation, as well as IFN-gamma production, during EAE. These findings suggest a similar mechanism of action for pixantrone and mitoxantrone on the effector function of lymphomonocyte B and T cells.