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Chemotherapy-induced painful peripheral neurotoxicity (painful-CIPN), with paresthesia, numbness, dysaesthesia, and neuropathic pain ranks among the most common dose-limiting toxicity of widely used anticancer drugs. Beside peripheral neurons, for several years considered the only reasonable target for painful-CIPN study, the recent evaluation of the microvascular angiogenesis in the somatosensory pathway, reveals other important actors in the neuropathic pain development and chronicization. To elucidate the relation between chemotherapy-induced neuropathic pain and vascular alterations, we evaluated the microvasculature in central and peripheral nervous compartments of rats exposed to neurotoxic chemotherapy. Rats were treated with paclitaxel 10 mg/kg once a week for 4 weeks, or with cisplatin 2mg/kg twice a week for 4 weeks or with their vehicles. Animals were tested for neurophysiological abnormalities and pain before and after the treatments. Post-mortem samples were analyzed at synchrotron radiation sources by X-ray Phase-Contrast Tomography (XPCT) Imaging and processed for quantitative and morphological analyses of microvascular structures. Complementarily, histochemical and molecular evaluations were performed to validate the results. XPCT analysis revealed that rats exposed to paclitaxel (affected by a painful sensory axonopathy) showed an increased vascular density (putative sprouting angiogenesis) in the crucial districts of the central (somatosensory cortex and lumbar spinal cord) and peripheral nervous system (lumbar Dorsal Root Ganglia and peripheral nerves). However, the complexity of the vascular network and the size of neo-formed vessels were significantly decreased in some specific regions. On the other hand, no significant changes were observed in rats exposed to CDDP (affected by a painless mild neuronopathy) suggesting a specific involvement of neo-angiogenesis in the development of neuropathic pain. Molecular analysis performed on the DRG and S1

Adverse reactions, toxicity, and poor compliance from patients still represent major challenges for conventional chemotherapy treatments. Localized drug delivery would ideally improve therapeutic efficacy, minimizing the side effects. An MSU-type mesoporous silica-based nanodevice (FOL-MSN-BTZ), able to selectively deliver the antineoplastic drug bortezomib (BTZ) to folate receptor over-expressing multiple myeloma (FR+ MM) cells is described. The receptor-specific ligand, folic acid, grafted on the external surface of the nanosystem, allows tumor recognition and cell internalization, while BTZ, mainly linked to the pore internal surface through a covalent pH-sensitive bond, is released in an acidic tumor environment. A detailed investigation showed that only the fine balancing of different functionalities of the nanodevice around the external and internal surfaces of MSN particles shows the absence of toxicity towards healthy cells in vitro and negligible BTZ-release at physiological pH, which are suitable features for applicative purposes in the engineering of therapies. After complete characterization in vitro, an accurate suspendability assessment, which considered the sedimentation process that reduces the particle amount and, consequently, drug content in the suspensions, allowed the development of an injectable formulation of FOL-MSN-BTZ that showed higher antitumor efficacy and an overall tendency to lower toxicity in a MM mice model compared to the conventional bortezomib chemotherapy.

Chemotherapy-induced peripheral neuropathy (CIPN) is a frequent side effect of various cancer chemotherapy treatments. Typically, CIPN manifests in patients as numbness, tingling, altered sensation, usually associated with neuropathic pain and, therefore the adjustment of chemotherapy dosages or even discontinuation of the treatment. Although various chemotherapeutic agents induce neuropathy, they do so by targeting different cellular processes and having different mechanisms. The pathomechanism by which chemotherapeutics damage the nervous is multifactorial and involves microtubule disruption, oxidative stress and mitochondrial damage, altered ion channel activity, myelin sheath damage, DNA damage, immunological processes and neuroinflammation. Neuroinflammation is one of the host defensive mechanisms and occurs as one of the most common pathological outcomes in most neurological and neurodegenerative diseases make it the promising target. Several CIPN preclinical studies suggest critical neuro-immune interactions as a mechanism of neurotoxicity. In this study we analyzed the presence of neuroinflammatory marker proteins in rats treated with chemotherapy drugs, in order to identify the neuroinflammasome as a pathological mechanism. Expression of inflammasome protein NLRP3, interleukin IL6 and chemokine CCL2 was analyzed in nervous tissue (DRG, spinal cord, caudal nerve, sciatic nerve) after chemotherapy with Paclitaxel, Oxaliplatin and Bortezomib. All three proteins showed a significant increase in the caudal nerve in Paclitaxel treatment over 4 weeks. Treatment with Oxaliplatin did not give any increase in protein expression, while Bortezomib showed a significant increase only for CCL2. Immunohistochemical staining represents infiltration of macrophages in caudale nerves in rats treated with Paclitaxel and Borthezomib but not Oxaliplatin. Neurophysiology and dynamic tests showed that rats treated with Paclitaxel and Bortezomib develop allodynia, reduce nerve condu

Background and Aims: Chemotherapy-induced peripheral neurotoxicity (CIPN) is a common and long-lasting adverse event of several anticancer compounds, for which treatment has not yet been developed. To fill this gap, preclinical studies are warranted, exploiting highly translational outcome measure(s) to transfer data from bench to bedside. Nerve excitability testing (NET) enables to test in vivo axonal properties and can be used to monitor early changes leading to axonal damage. Methods: We tested NET use in two different CIPN rat models: oxaliplatin (OHP) and paclitaxel (PTX). Animals (female) were chronically treated with either PTX or OHP and compared to respective control animals. NET was performed as soon as the first injection was administered. At the end of the treatment, CIPN onset was verified via a multimodal and robust approach: nerve conduction studies, nerve morphometry, behavioural tests and intraepidermal nerve fibre density. Results: NET showed the typical pattern of axonal hyperexcitability in the 72 h following the first OHP administration, whereas it showed precocious signs of axonal damage in PTX animals. At the end of the month of treatment, OHP animals showed a pattern compatible with a mild axonal sensory polyneuropathy. Instead, PTX cohort was characterised by a rather severe sensory axonal polyneuropathy with minor signs of motor involvement. Interpretation: NET after the first administration demonstrated the ongoing OHP-related channelopathy, whereas in PTX cohort it showed precocious signs of axonal damage. Therefore, NET could be suggested as an early surrogate marker in clinical trials, to detect precocious changes leading to axonal damage.

Peripheral Neuropathies (PN) are common conditions whose treatment is still lacking in most cases. Animal models are crucial, but experimental procedures should be refined in some cases. We performed a detailed characterization of the ventral caudal nerve to contribute to a more effective assessment of axonal damage in future PN studies. PN was induced via weekly systemic injection of a neurotoxic drug (paclitaxel); we compared the control and PN-affected rats, performing serial neurophysiological evaluations of the caudal nerve for its entire length. On the same nerve portions, we performed light microscopy and ultrastructural pathological observations to assess the severity of damage and verify the integrity of the surrounding structures. Neurophysiological and morphological analyses confirmed that a severe axonopathy had ensued in the PN group, with a length-dependent modality, matching morphological observations. The site of neurophysiological recording (e.g., distance from the base of the tail) was critical for achieving useful data. A flexible experimental paradigm should be considered in animal studies investigating axonal PN, particularly if the expected severity is relevant; the mid-portion of the tail might be the most appropriate site: there damage might be remarkable but neither as extreme as at the tip of the tail nor as mild as at the base of the tail.

Chemotherapy-induced peripheral neurotoxicity is one of the most common dose-limiting toxicities of several widely used anticancer drugs such as platinum derivatives (cisplatin) and taxanes (paclitaxel). Several molecular mechanisms related to the onset of neurotoxicity have already been proposed, most of them having the sensory neurons of the dorsal root ganglia (DRG) and the peripheral nerve fibers as principal targets. In this study we explore chemotherapy-induced peripheral neurotoxicity beyond the neuronocentric view, investigating the changes induced by paclitaxel (PTX) and cisplatin (CDDP) on satellite glial cells (SGC) in the DRG and their crosstalk. Rats were chronically treated with PTX (10 mg/Kg, 1qwx4) or CDDP (2 mg/Kg 2qwx4) or respective vehicles. Morpho-functional analyses were performed to verify the features of drug-induced peripheral neurotoxicity. Qualitative and quantitative immunohistochemistry, 3D immunofluorescence, immunoblotting, and transmission electron microscopy analyses were also performed to detect alterations in SGCs and their interconnections. We demonstrated that PTX, but not CDDP, produces a strong activation of SGCs in the DRG, by altering their interconnections and their physical contact with sensory neurons. SGCs may act as principal actors in PTX-induced peripheral neurotoxicity, paving the way for the identification of new druggable targets for the treatment and prevention of chemotherapy-induced peripheral neurotoxicity.

In northern Italy, biomass burning-derived (BB) particles and diesel exhaust particles (DEP) are considered the most significant contributors to ultrafine particle (UFP) emission. However, a comparison between their impact on different brain regions was not investigated until now. Therefore, male BALB/c mice were treated with a single or three consecutive intratracheal instillations using 50 µg of UFPs in 100 µL of isotonic saline solution or 100 µL of isotonic saline solution alone, and brains were collected and analyzed. Proteins related to oxidative stress and inflammation, as well as Alzheimer’s disease markers, were examined in the hippocampus, cerebellum, and the rest of the brain (RoB). Histopathological examination of the brain was also performed. Moreover, correlations among different brain, pulmonary, and cardiovascular markers were performed, allowing us to identify the potentially most stressful UFP source. Although both acute exposures induced inflammatory pathways in mouse brain, only DEP showed strong oxidative stress. The sub-acute exposure also induced the modulation of APP and BACE1 protein levels for both UFPs. We observed that DEP exposure is more harmful than BB, and this different response could be explained by this UFP’s different chemical composition and reactivity.

Oxaliplatin is a cornerstone chemotherapeutic used in the treatment of colorectal cancer, the third leading cause of death in Western countries. Most side effects of this platinum-containing drug are adequately managed in the clinic, although acute and long-term neurotoxicity still severely compromises the quality of life of patients treated with oxaliplatin. We have previously demonstrated that therapeutically relevant concentrations/doses of oxaliplatin lead to a reduction in intracellular pH in mouse dorsal root ganglion (DRG) neurons in vitro and in vivo and that this alteration sensitizes TRPA1 and TRPV1 channels, which most likely mediate the allodynia associated with treatment. In this study, we show that oxaliplatin leads to a reduction of intracellular pH by forming adducts with neuronal haemoglobin, which acts in this setting as a proton buffer. Furthermore, we show that FDA-approved drugs that inhibit carbonic anhydrase (an enzyme that is linked to haemoglobin in intracellular pH homeostasis), ie, topiramate and acetazolamide, revert (1) oxaliplatin-induced cytosolic acidification and TRPA1 and TRPV1 modulation in DRG neurons in culture, (2) oxaliplatin-induced cytosolic acidification of DRG of treated animals, and (3) oxaliplatin-induced acute cold allodynia in mice while not affecting OHP-induced cytotoxicity on cancer cells. Our data would therefore suggest that reversal of oxaliplatin-induced cytosolic acidification is a viable strategy to minimize acute oxaliplatin-induced symptoms

Mesenchymal Stem Cells (MSCs) are adult multipotent cells able to increase sensory neuron survival: direct co-culture of MSCs with neurons is pivotal to observe a neuronal survival increase. Despite the identification of some mechanisms of action, little is known about how MSCs physically interact with neurons. The aim of this paper was to investigate and characterize the main mechanisms of interaction between MSCs and neurons. Morphological analysis showed the presence of gap junctions and tunneling nanotubes between MSCs and neurons only in direct co-cultures. Using a diffusible dye, we observed a flow from MSCs to neurons and further analysis demonstrated that MSCs donated mitochondria to neurons. Treatment of co-cultures with the gap junction blocker Carbenoxolone decreased neuronal survival, thus demonstrating the importance of gap junctions and, more in general, of cell communication for the MSC positive effect. We also investigated the role of extracellular vesicles; administration of direct co-cultures-derived vesicles was able to increase neuronal survival. In conclusion, our study demonstrates the presence and the importance of multiple routes of communication between MSCs and neurons. Such knowledge will allow a better understanding of the potential of MSCs and how to maximize their positive effect, with the final aim to provide the best protective treatment.

Oxaliplatin (OHP)-induced peripheral neurotoxicity (OIPN) is a frequent adverse event of colorectal cancer treatment. OIPN encompasses a chronic and an acute syndrome. The latter consists of transient axonal hyperexcitability, due to unbalance in Na+ voltage-operated channels (Na+VOC). This leads to sustained depolarisation which can activate the reverse mode of the Na+/Ca2+ exchanger 2 (NCX2), resulting in toxic Ca2+ accumulation and axonal damage (ADa). We explored the role of NCX2 in in vitro and in vivo settings. Embryonic rat Dorsal Root Ganglia (DRG) organotypic cultures treated with SEA0400 (SEA), a NCX inhibitor, were used to assess neuroprotection in a proof-of-concept and pilot study to exploit NCX modulation to prevent ADa. In vivo, OHP treated mice (7 mg/Kg, i.v., once a week for 8 weeks) were compared with a vehicle-treated group (n = 12 each). Neurophysiological and behavioural testing were performed to characterise acute and chronic OIPN, and morphological analyses were performed to detect ADa. Immunohistochemistry, immunofluorescence, and western blotting (WB) analyses were also performed to demonstrate changes in NCX2 immunoreactivity and protein expression. In vitro, NCX inhibition was matched by ADa mitigation. In the in vivo part, after verifyingboth acute and chronic OIPN had ensued, we confirmed via immunohistochemistry, immunofluorescence, and WB that a significant NCX2 alteration had ensued in the OHP group. Our data suggest NCX2 involvement in ADa development, paving the way to a new line of research to prevent OIPN.

Aging is associated with an exaggerated response to peripheral inflammatory challenges together with behavioral and cognitive deficits. Studies considering both age and sex remain limited, despite sex dimorphism of astrocytes and microglial cells is largely recognized. To fill this knowledge gap, we investigated the effect of a single intraperitoneal lipopolysaccharide (LPS) administration in adult and aged mice. We assessed the expression of different inflammatory mediators, and the microglial response through binding of [18F]-VC701 tracer to translocator protein (TSPO) receptors in the male and female brain. Aged female brain showed a higher pro-inflammatory response to LPS compared to adult female and to aged male, as revealed by ex vivo binding to TSPO receptors and pro-inflammatory mediator transcript levels. The highest astroglial reaction was observed in the brain of aged females. Differently to the other groups of animals, in aged males LPS challenge did not affect transcription of triggering receptor expressed on myeloid cells 2 (TREM2). In conclusion, our study shows that in the mouse’s brain the neuro-inflammatory response to an acute peripheral insult is sex- and age-dependent. Moreover, our results might set the basis for further studies aimed at identifying sex-related targets involved in the modulation of the aberrant neuro-inflammatory response that characterizes aging. This knowledge could be relevant for the treatment of conditions such as delirium and dementia.

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.

Celiac disease (CD) is an autoimmune enteropathy arising in genetically predisposed subjects exposed to gluten, which activates both innate and adaptive immunity. Although the pathogenesis is common to all patients, the clinical spectrum is quite variable, and differences could be explained by gene expression variations. Among the factors able to affect gene expression, there are lncRNAs. We evaluated the expression profile of 87 lncRNAs in CD vs. healthy control (HC) intestinal biopsies by RT-qPCR array. Nuclear enriched abundant transcript 1 (NEAT1) and taurine upregulated gene 1 (TUG1) were detected as downregulated in CD patients at diagnosis, but their expression increased in biopsies of patients on a gluten-free diet (GFD) exposed to gluten. The increase in NEAT1 expression after gluten exposure was mediated by IL-15 and STAT3 activation and binding to the NEAT1 promoter, as demonstrated by gel shift assay. NEAT1 is localized in the nucleus and can regulate gene expression by sequestering transcription factors, and it has been implicated in immune regulation and control of cell proliferation. The demonstration of its regulation by gluten thus also supports the role of lncRNAs in CD and prompts further research on these RNAs as gene expression regulators.

Neurotoxicity is the most debilitating non-haematological adverse effect of paclitaxel (PTX) in cancer patients. Symptoms are typical of a sensory peripheral neuropathy and the incidence and degree are dependent on the cumulative dose. The symptoms include paraesthesia, disaesthesia, tingling, and numbness. Moreover, many patients develop allodynia and hyperalgesia, experiencing a severe neuropathic pain (NP). NP can originate from a peripheral sensitization then transmitted to upper centers in the central nervous system where it can determine structural and functional changes (altered neuronal discharge patterns). Preliminary evidences in other NP models showed an abundant microvascular neoangiogenesis in the primary somatosensory cortex, specifically on the hindlimb projection. The aim of this work is to investigate the microstructural vascular anomalies both in the central somatosensory pathway and peripheral (dorsal root ganglia, DRG) compartments in rats exposed to chronic PTX treatment. We treated 24 rats with PTX 10 mg/kg once a week for 4 weeks to induce a painful peripheral neuropathy. Animals were tested for neurophysiological abnormalities and behavioral NP before and after treatment. Then animals were sacrificed and perfused with fixative and/or indian-ink before collecting samples. Samples have been analyzed at synchrotron radiation resources by X-ray Phase-Contrast Tomography (XPCT) Imaging (Diamond, Didcot, UK and ESRF, Grenoble, France). Volume rendering allowed for a detailed visualization of vasculature at the sub micrometric scale. Quantitative and morphological analyses of micro-vascular structures with comparative comparisons between control and NP rats. Histochemical and histological evaluations have been performed to validate the results obtained by XPCT. A significant increased number of vessels has been found in NP samples, suggesting a neoangiogenesis at the capillary level in NP condition. The effect was larger (about +173%) on central sta

Dorsal root ganglia (DRG) sensitive neurons represent the connection between the peripheral sensorial receptors and the central nervous system. These neurons are enwrapped individually by the satellite glial cells (SCGs) from which they receive metabolic support. Together, neuron and SCGs, become a functional unit that, in absence of the blood brain barrier, is easily exposed to external stress and damage insults. This intimate connection/relationship, both morphological and functional, can be partially pictured and studied following traditional slicing 2D histopathological techniques. Indeed, morphological cellular and subcellular alterations and changes in protein expression and/or distribution can be observed using classical techniques. However, a whole-3D approach avoids the serial sectioning required for quantitative results plus is able to show the cyto-architecture of the organ and a more complete picture of the anatomical relationship between cell populations close to physiological conditions. Here we use a 3D imaging technique to show the cyto-architecture of the DRG after “colouring” by immunofluorescence the different DRG cell populations and to assess alterations in DRG of neuropathic rats. CGRP, IB4 and MAP2 markers were useful to study the different neuronal populations. The IB4-MAP2 combination was able to label all neurons while the CGRP-IB4 couple could not but still both settings showed a small subpopulation of neurons where the proteins were co-expressed. Moreover, GFAP, ATF3 and connexin 43 were used as markers of damage in the DRG from neuropathic animals.

Neurotoxicity is the most debilitating non-haematological adverse effect of paclitaxel (PTX) in cancer patients that report typical symptoms of a dose cumulative sensory peripheral neuropathy with paraesthesia, disaesthesia, tingling, and numbness. Many patients develop allodynia and hyperalgesia, experiencing neuropathic pain (NP). NP can originate from a peripheral sensitization then transmitted to the central nervous system where it can determine structural and functional changes. An abundant microvascular angiogenesis was described in the primary somatosensory cortex, specifically on the hindlimb projection of rats with NP of other origin. In this work, we investigated the microstructural vascular anomalies in the central somatosensory pathway and peripheral compartments (dorsal root ganglia, DRG) in rats exposed to chronic PTX treatment. Twenty-four rats were chronically treated with PTX 10 mg/kg to induce a painful peripheral neuropathy. Animals were tested for neurophysiological abnormalities and behavioral NP and finally perfused with fixative and/or indian ink before collecting samples. Samples have been analyzed at synchrotron radiation resources by X-ray Phase-Contrast Tomography (XPCT) Imaging (Diamond, Didcot, UK and ESRF, Grenoble, France). Volume rendering allowed a detailed visualization of vasculature at the sub micrometric scale. We performed a quantitative and morphological analysis of micro-vascular structures in PNS and CSN of control and NP rats. Histochemical and histological evaluations validated the results obtained by XPCT. A significant increased number of vessels has been found in NP samples, suggesting an angiogenesis at the capillary level in NP condition. The effect was larger (about +173%) in somatosensory cortex, still relevant in lumbar spinal cord and noticeable in related DRG. Specific analyses indicated that neo-formed vessels were smaller than 15 micron. Moreover, a significant decrement of the number of capillary branch points

Chemotherapy-induced peripheral neurotoxicity (CIPN) is one of the most important side-effect of several anticancer drugs, including Paclitaxel (PTX, taxane family) and Vincristine (VCR, vinca alkaloid family). The mechanisms involved in CIPN onset are not completely understood; several neurotoxic hypotheses have been proposed, among which the role of the neuroinflammation process is emerging. In particular, different studies demonstrated that the role of macrophage infiltration correlated to neurotoxicity and sensory nervous system sensitization. We investigated the presence of macrophage infiltratE in two well-assessed preclinical models of PTX- and VCR- induced peripheral neurotoxicity. Female Wistar rats were divided in control (CTRL), PTX- (10mg/kg i.v. q7dx4 ws) and VCR- (0.2mg/kg i.v. q7dx4 ws) treated groups. The development of CIPN was confirmed by neurophysiological, morphological examinations and behavioral tests, whereas macrophage infiltration and description were obtained by immunoistochemical analyses. PTX and VCR chronic administration induced different degrees of axonal damage and macrophage infiltration in peripheral nerves. In particular, macrophage infiltrate was detected from the first week of treatment in PTX-treated animals, with a progressive increase until the end of treatment. On the contrary, VCR treatment induced a milder macrophage infiltration detected after 2 weeks of treatment, which remained constant until the end of the experiment. Moreover, immunoistochemical analyses evidenced that all the infiltrating cells had a pro-inflammatory phenotype. CIPN was detected from the second week after both anticancer administrations, with a stronger severity in PTX group compared to VCR one. These preliminary results evidence a different amount of macrophage infiltration in CIPN induced by PTX and VCR. Since the detection of inflammatory infiltrate was early and sustained until the end of the drug treatment, it could have a relevant role into the