A mechanistic understanding of the relationship between skin innervation and chemotherapy-induced neuropathic pain

Neuropathic pain is a frequent complication of chemotherapy-induced peripheral neurotoxicity (CIPN). Chemotherapy-induced peripheral neuropathies may serve as a model to study mechanisms of neuropathic pain, since several other common causes of peripheral neuropathy like painful diabetic neuropathy may be due to both neuropathic and non-neuropathic pain mechanisms like ischemia and inflammation. Experimental studies are ideally suited to study changes in morphology, phenotype and electrophysiologic characteristics of primary afferent neurons that are affected by chemotherapy and to correlate these changes to behaviors reflective of evoked pain, mainly hyperalgesia and allodynia. However, hyperalgesia and allodynia may only represent one aspect of human pain, i.e., the sensory-discriminative component, while patients with CIPN often describe their pain using words like annoying, tiring and dreadful, which are affective-emotional descriptors that cannot be tested in experimental animals. To understand why some patients with CIPN develop neuropathic pain and others not, and which are the components of neuropathic pain that they are experiencing, experimental and clinical pain research should be combined. Emerging evidence suggests that changes in subsets of primary afferent nerve fibers may contribute to specific aspects of neuropathic pain in both preclinical models and in patients with CIPN. In addition, the role of cutaneous neuroimmune interactions is considered. Since obtaining dorsal root ganglia and peripheral nerves in patients is problematic, analyses performed on skin biopsies from preclinical models as well as patients provide an opportunity to study changes in primary afferent nerve fibers and to associate these changes to human pain. In addition, other biomarkers of small fiber damage in CIPN, like corneal confocal microscope and quantitative sensory testing, may be considered

Influence of aging on peripheral nervous system: a morphological and morphometric study

It is well known that aging influences several functional and structural features of peripheral nerves (Verdù et al., 2000; Ceballos et al., 1999; Jeronimo et al., 2008). However, the role of these changes in the damage/repair mechanisms occurring in acquired peripheral neuropathies is still unclear. To this aim, a multimodal, long-term assessment in a mice model would represent an optimal tool to perform experimental neuropathy studies designed to evaluate the role of aging in relationship with a given nerve injury. In this study we used 40 females one-month-old C57B1/6 mice and we followed-up them for fifteen months. Digital and caudal nerve conduction velocity (NCV) studies were performed monthly to evaluate changes in electrophysiological features; moreover, four animals were sacrificed every two months in order to collect caudal nerve, sciatic nerve, dorsal root ganglia (DRG) and skin for morphological and morphometric analysis. The neurophysiological assessments showed a remarkable increase of caudal NCV until the age of 9 months and then it remained unchanged until the end of the observation period; in the same period, digital NCV increase was also present although less marked. At the pathological level, both caudal and sciatic nerves showed a decrease in fibres density related with age, whereas axon and fibres diameters tended to increase. These preliminary data can be considered a first step aiming at creating a background for future studies on the relationship between aging and peripheral nervous system induced damage

A new animal model of chemotherapy induced peripheral neurotoxicity: the immune-deficient mouse

Cisplatin, paclitaxel and bortezomib are anticancer drugs widely employed in the treatment of different solid tumours even though peripheral neurotoxicity represents a major limitation in their clinical use. During the last decades many rat and mouse models of chronic chemotherapyinduced peripheral neurotoxicity (CIPN) have been characterized from the clinical, pathological, neurophysiological and behavioural point of view. These models were based on immune-competent animals, however in preclinical oncology immune-deficient mice are mainly used. In this respect, the development of immune-deficient mice models could represent a basis for the concurrent investigation of both anticancer drug efficacy and neurotoxicity in animals implanted with human-derived cancer. Moreover, in the same model, neuroprotective effects and non-interference with anticancer activity could be better studied. In this study we established the feasibility of new immune-deficient murine models of peripheral neurotoxicity induced by three anticancer drugs. Forty-eight athymic nude mice were randomized in 4 groups of 12 animals, three were treated respectively with cisplatin, paclitaxel and bortezomib, and one was left untreated. All animals were followed up for 6 weeks. They were examined at baseline, week 4 and 6 for neurophysiological functions and behavioural tests, whilst morphological and morphometric analysis were performed on dorsal root ganglia (DRG) and peripheral nerves collected after 4 and 6 weeks of treatment. The results of the study demonstrate that athymic nude mice show CIPN features similar to those observed in conventional models even if some differences must be remarked as the prolonged time of treatment required to develop a chronic neuropathy. The characterization of this new mice model of CIPN will allow studies of antineoplastic and neurotoxic effects in the same animal

Tubulin involvement in Bortezomib peripheral neurotoxicity

Axonal transport of mitochondria (Mt) controlled by specialized motor and docking proteins that distribute Mt throughout the axon where they provide energy for metabolic and synaptic activity is a vulnerable target in neuronal pathology (1). Bortezomib (BZ) is a proteasome inhibitor active in multiple myeloma (2). One of its key toxicities is painful peripheral neuropathy (BIPN), which frequently requires treatment discontinuation (3). BIPN is dose-related and predominantly sensory, resulting from axonal degeneration. Recent results indicate that BZ modifies axonal tubulin dynamic and we hypothesize that BZ alters fast axonal transport. Here we studied using time-lapse imaging the effect of different BZ concentration on axonal Mt transport in isolated dorsal root ganglion (DRG) neurons from adult male mice. We used kymograph to quantify the total number of Mt and to discriminate antero and retrogradely moving Mt from stationary Mt. Twenty-four hours of BZ treatment (0.1 to 15 µM) induced a dose-dependent reduction in Mt trafficking. Moreover, BZ had no impact on MT motion directions, but it induced a progressive reduction of both anterograde and retrograde axonal transport velocities. These events were associated with increase in tubulin polymerization and of MAP2 expression, but they occurred only after 72h of chronic BZ treatment. We have developed an in vitro model of BIPN demonstrating that transport impairment is already present before evident tubulin polymerization, suggesting that transport deficit represents an early stage of axonal dysfunction. Perpetuated transport dysfunction could impair distal organelle supply and play a critical role in advanced stages of BIPN.This work was supported by the University of Milan-Bicocca and University of Michigan research grant

Givinostat-Liposomes: Anti-Tumor Effect on 2D and 3D Glioblastoma Models and Pharmacokinetics

Glioblastoma is the most common and aggressive brain tumor, associated with poor prognosis and survival, representing a challenging medical issue for neurooncologists. Dysregulation of histone-modifying enzymes (HDACs) is commonly identified in many tumors and has been linked to cancer proliferation, changes in metabolism, and drug resistance. These findings led to the development of HDAC inhibitors, which are limited by their narrow therapeutic index. In this work, we provide the proof of concept for a delivery system that can improve the in vivo half-life and increase the brain delivery of Givinostat, a pan-HDAC inhibitor. Here, 150-nm-sized liposomes composed of cholesterol and sphingomyelin with or without surface decoration with mApoE peptide, inhibited human glioblastoma cell growth in 2D and 3D models by inducing a time-and dose-dependent reduction in cell viability, reduction in the receptors involved in cholesterol metabolism (from −25% to −75% of protein levels), and reduction in HDAC activity (−25% within 30 min). In addition, liposome-Givinostat formulations showed a 2.5-fold increase in the drug half-life in the bloodstream and a 6-fold increase in the amount of drug entering the brain in healthy mice, without any signs of overt toxicity. These features make liposomes loaded with Givinostat valuable as potential candidates for glioblastoma therapy

Positive effect of Mesenchymal Stem Cells therapeutic administration on chronic Experimental Autoimmune Encephalomyelitis

Multiple Sclerosis (MS) is a crippling chronic disease of the Central Nervous System caused by the presence of self-antibodies which progressively damage axonal myelin sheath, leading to axonal transmission impairment and to the development of neurological symptoms. MS is characterized by a Relapsing-Remitting course, and current therapies rely only on the use of immunosuppressive drugs, which are however unable to reverse disease progression. Encouraging results have been obtained in preclinical studies with the administration of Mesenchymal Stem Cells (MSCs) before disease onset (Zappia et al., 2005). Here, we investigate the therapeutic potential of MSC administration after disease onset into an animal model of MS, represented by Dark Agouti rats affected by chronic Relapsing-Remitting Experimental Autoimmune Encephalomyelitis (EAE) (Cavaletti et al., 2004). 106 MSC were intravenously injected in EAE rats after disease onset. Clinical score was assessed daily, and after 45 days rats were sacrificed and histological analysis of spinal cords performed to evaluate the demyelinating lesions. After the first peak of disease, no further relapses were observed in EAE rats treated with MSCs, differently from what observed in EAE group. Histological analysis demonstrated the presence of demyelinated plaques in spinal cords of EAE rats, (Luxol fast Blue staining and anti-MBP immunohystochemistry). On the contrary the therapeutic schedule with MSCs significantly reduces the number and the extension of demyelinated areas in the spinal cords, confirming clinical score evaluations. These results demonstrated that MSCs ameliorate the clinical course of EAE and hamper the disease relapsing by reducing the areas of demyelinated lesions. Granted by MIUR – FIRB Futuro in Ricerca 2008 Prot. N° RBFR08VSVI_001

Observatório Socioambiental em Segurança Alimentar e Nutricional: análise dos indicadores de produção de alimentos em nível municipal no Rio Grande do Sul

Since the 1990, the theme of Human Rights and Food Security (FS) has been developed in Brazil, culminating in the construction of the National Policy and Plan of Food Security (PNSAN and PLANSAN 2012/2015). The PLANSAN proposes sixty indicators divided into seven dimensions, which are clearly related to the Millennium Development Goals. In order to operationalize these indicators in the State of Rio Grande do Sul (RS), the Socio-Environmental Food Security Observatory of Rio Grande do Sul (OBSSAN-RS) was created in partnership with the State Council for Nutrition and Food Security (CONSEA-RS) and the Informatics Department of UFRGS. In this context, the aim of this paper is to present the analysis of indicators of Dimension I (Food Production) of the OBSSAN-RS at municipal level, discussing the importance of this tool for monitoring the establishment of the Human Right to Adequate Food (DHAA). The data available to the municipal level were compared with the indicators suggested by PLANSAN. It was observed that although contemplate important information for understanding the context of food production in the municipalities of the state, the proposed indicators have not reached entirely the requirements to monitoring the SAN in this territorial level, so adapting it is necessary to rating the state of SAN in municipalities of the RS.Desde a década de 1990, a temática dos Direitos Humanos e da Segurança Alimentar e Nutricional - SAN vem sendo desenvolvida no Brasil, culminando na construção da Política e do Plano Nacional de SAN (PNSAN e PLANSAN 2012/2015). O PLANSAN propõe 60 indicadores divididos em sete dimensões, os quais estabelecem clara relação com os Objetivos de Desenvolvimento do Milênio. Com o intuito de operacionalizar esses indicadores no Estado do Rio Grande do Sul - RS foi criado o Observatório Socioambiental em Segurança Alimentar e Nutricional do Rio Grande do Sul - OBSSAN-RS, em parceria com o Conselho Estadual de Segurança Alimentar e Nutricional - CONSEA-RS e o Departamento de Informática da UFRGS. Neste contexto, o objetivo deste trabalho é apresentar a análise dos indicadores da Dimensão I (Produção de Alimentos) do OBSSAN-RS em nível municipal, discutindo a importância dessa ferramenta para o monitoramento do estabelecimento do Direito Humano à Alimentação Adequada - DHAA. Os dados disponíveis para o nível municipal foram comparados com os indicadores sugeridos pelo PLANSAN. Observou-se que, apesar de contemplarem informações importantes para a compreensão do contexto da produção de alimentos dos municípios do estado, os indicadores propostos alcançam apenas em parte as necessidades para o monitoramento da SAN neste nível territorial, sendo necessária sua adaptação para a avaliação da SAN nos municípios do RS

Oxaliplatin-induced peripheral neurotoxicity: morphological characterization in different mouse strains

Oxaliplatin is one of the most effective anticancer drug, particularly employed in the treatment of colorectal cancer, but one of the major limitation in its use is peripheral neurotoxicity. Oxaliplatin induced peripheral neurotoxicity (OIPN) has a high incidence and is frequently long lasting or permanent. Neuropathy is characterized by distal sensory impairment initially in the legs, then extending to the arms. A prominent manifestation of sensitive damage is ataxia. Besides chronic neurotoxicity, many patients experience an acute, rapidly developing cold-induced sensory neuropathy, usually resolving within one week. OIPN clinical manifestations reflect the involvement of dorsal root ganglia (DRG) as primary target of the drug toxicity. Although this assumption is largely accepted and some pathogenetic hypothesis have been proposed, mechanisms at the basis of OIPN need to be clearly defined. OIPN may vary in frequency and severity among different cancer patients despite equal treatment schedules. A genetic susceptibility for more severe oxaliplatin-induced peripheral neurotoxicity (OIPN) has been suggested but never confirmed. Therefore we designed a study to assess the phenotypic differences induced by oxaliplatin treatment in six different mice strains (Balb c, AJ, C57Bl6, FVB, DBA, CD1) aiming at identifying the more and less severely affected. Animals were treated with OHP 3.5 mg/Kg/iv twice weekly x 4 weeks and evaluated before and after treatment. In all strains we performed a multimodal characterization of its neurotoxicity through morphological and morphometrical assessment in caudal nerve and DRG at light and electron microscopy, intra-epidermal nerve fibers density quantification, evaluation of mechanical and cold allodynia/hypoaesteshesia, caudal and digital nerve conduction velocity, activity of wide dynamic range (WDR) neurons of the spinal dorsal horn. Our preliminary data suggest that all the strains show signs of OIPN but not the same modifications in the parameters examined. We will show these results with particular attention to morphological data. This study suggests that genetic variability might have a role in the type and severity of OHP-induced peripheral damage

The risk stratification of adverse neonatal outcomes in women with gestational diabetes (STRONG) study

Aims: To assess the risk of adverse neonatal outcomes in women with gestational diabetes (GDM) by identifying subgroups of women at higher risk to recognize the characteristics most associated with an excess of risk. Methods: Observational, retrospective, multicenter study involving consecutive women with GDM. To identify distinct and homogeneous subgroups of women at a higher risk, the RECursive Partitioning and AMalgamation (RECPAM) method was used. Overall, 2736 pregnancies complicated by GDM were analyzed. The main outcome measure was the occurrence of adverse neonatal outcomes in pregnancies complicated by GDM. Results: Among study participants (median age 36.8 years, pre-gestational BMI 24.8 kg/m2), six miscarriages, one neonatal death, but no maternal death was recorded. The occurrence of the cumulative adverse outcome (OR 2.48, 95% CI 1.59–3.87), large for gestational age (OR 3.99, 95% CI 2.40–6.63), fetal malformation (OR 2.66, 95% CI 1.00–7.18), and respiratory distress (OR 4.33, 95% CI 1.33–14.12) was associated with previous macrosomia. Large for gestational age was also associated with obesity (OR 1.46, 95% CI 1.00–2.15). Small for gestational age was associated with first trimester glucose levels (OR 1.96, 95% CI 1.04–3.69). Neonatal hypoglycemia was associated with overweight (OR 1.52, 95% CI 1.02–2.27) and obesity (OR 1.62, 95% CI 1.04–2.51). The RECPAM analysis identified high-risk subgroups mainly characterized by high pre-pregnancy BMI (OR 1.68, 95% CI 1.21–2.33 for obese; OR 1.38 95% CI 1.03–1.87 for overweight). Conclusions: A deep investigation on the factors associated with adverse neonatal outcomes requires a risk stratification. In particular, great attention must be paid to the prevention and treatment of obesity