Administration of adipose-derived stem cells extracellular vesicles in a murine model of spinal muscular atrophy: effects of a new potential therapeutic strategy.

BACKGROUND: Spinal Muscular Atrophy (SMA) is an autosomal-recessive neuromuscular disease affecting children. It is caused by the mutation or deletion of the survival motor neuron 1 (SMN1) gene resulting in lower motor neuron (MN) degeneration followed by motor impairment, progressive skeletal muscle paralysis and respiratory failure. In addition to the already existing therapies, a possible combinatorial strategy could be represented by the use of adipose-derived mesenchymal stem cells (ASCs) that can be obtained easily and in large amounts from adipose tissue. Their efficacy seems to be correlated to their paracrine activity and the production of soluble factors released through extracellular vesicles (EVs). EVs are important mediators of intercellular communication with a diameter between 30 and 100 nm. Their use in other neurodegenerative disorders showed a neuroprotective effect thanks to the release of their content, especially proteins, miRNAs and mRNAs. METHODS: In this study, we evaluated the effect of EVs isolated from ASCs (ASC-EVs) in the SMNΔ7 mice, a severe SMA model. With this purpose, we performed two administrations of ASC-EVs (0.5 µg) in SMA pups via intracerebroventricular injections at post-natal day 3 (P3) and P6. We then assessed the treatment efficacy by behavioural test from P2 to P10 and histological analyses at P10. RESULTS: The results showed positive effects of ASC-EVs on the disease progression, with improved motor performance and a significant delay in spinal MN degeneration of treated animals. ASC-EVs could also reduce the apoptotic activation (cleaved Caspase-3) and modulate the neuroinflammation with an observed decreased glial activation in lumbar spinal cord, while at peripheral level ASC-EVs could only partially limit the muscular atrophy and fiber denervation. CONCLUSIONS: Our results could encourage the use of ASC-EVs as a therapeutic combinatorial treatment for SMA, bypassing the controversial use of stem cells.

Evaluation of prenatal calabash chalk geophagy on the developing brain of Wistar rats.

Calabash chalk (CaC) is an aluminium silicate hydroxide compound with heavy metal constituents, making it a potential neurotoxicant. Pregnant women often consume CaC as an antiemetic, which may interfere with the normal development of the foetal brain. Here, we evaluated the effects of CaC administration in pregnant rats on the brain of the offspring. Wistar rat dams were assigned to one of three groups: control, 200 mg/kg and 800 mg/kg of a CaC suspension. Administrations lasted 14 days (gestation days 7-20). On day 14, 5-bromo-2'-deoxyuridine (BrdU) was administered and dams were allowed to term. Behavioural tests were performed on different days as the pups matured, and they were sacrificed on post-natal days 30 and 60. Brains were processed for histology and Western blotting. Results showed no significant differences in surface righting reflex, cliff avoidance, negative geotaxis and open-field activity. No hippocampal and somatosensory cortical cytoarchitectonic alterations and no significant signs of glial fibrillary acidic protein (GFAP) activation were observed. Neuronal nuclei counts showed variability in the somatosensory cortex and hippocampus of the CaC group. BrdU-positive cells were significantly lower in the 200 mg/kg group and higher in the 800 mg/kg group. Doublecortin-X-positive cells were not different in all the CaC groups. Astrocytes and microglia Western blotting quantification confirmed no significant increase in pup glial cells in adulthood. Prenatal consumption of CaC at indicated dosages may not be deleterious to the developing brain, especially after cessation of exposure and during maturation of the animal. However, the differences in neuronal and glial populations may be due to their ability to cope with CaC.

Extracellular vesicles from adipose mesenchymal stem cells target inflamed lymph nodes in experimental autoimmune encephalomyelitis.

BACKGROUND AIMS: Adipose mesenchymal stem cells (ASCs) represent a promising therapeutic approach in inflammatory neurological disorders, including multiple sclerosis (MS). Recent lines of evidence indicate that most biological activities of ASCs are mediated by the delivery of soluble factors enclosed in extracellular vesicles (EVs). Indeed, we have previously demonstrated that small EVs derived from ASCs (ASC-EVs) ameliorate experimental autoimmune encephalomyelitis (EAE), a murine model of MS. The precise mechanisms and molecular/cellular target of EVs during EAE are still unknown. METHODS: To investigate the homing of ASC-EVs, we intravenously injected small EVs loaded with ultra-small superparamagnetic iron oxide nanoparticles (USPIO) at disease onset in EAE-induced C57Bl/6J mice. Histochemical analysis and transmission electron microscopy were carried out 48 h after EV treatment. Moreover, to assess the cellular target of EVs, flow cytometry on cells extracted ex vivo from EAE mouse lymph nodes was performed. RESULTS: Histochemical and ultrastructural analysis showed the presence of labeled EVs in lymph nodes but not in lungs and spinal cord of EAE injected mice. Moreover, we identified the cellular target of EVs in EAE lymph nodes by flow cytometry: ASC-EVs were preferentially located in macrophages, with a consistent amount also noted in dendritic cells and CD4+ T lymphocytes. CONCLUSIONS: This represents the first direct evidence of the privileged localization of ASC-EVs in draining lymph nodes of EAE after systemic injection. These data provide prominent information on the distribution, uptake and retention of ASC-EVs, which may help in the development of EV-based therapy in MS.

Extracellular Vesicles from Mesenchymal Stem Cells: Towards Novel Therapeutic Strategies for Neurodegenerative Diseases.

Neurodegenerative diseases are fatal disorders of the central nervous system (CNS) which currently lack effective treatments. The application of mesenchymal stem cells (MSCs) represents a new promising approach for treating these incurable disorders. Growing evidence suggest that the therapeutic effects of MSCs are due to the secretion of neurotrophic molecules through extracellular vesicles. The extracellular vesicles produced by MSCs (MSC-EVs) have valuable innate properties deriving from parental cells and could be exploited as cell-free treatments for many neurological diseases. In particular, thanks to their small size, they are able to overcome biological barriers and reach lesion sites inside the CNS. They have a considerable pharmacokinetic and safety profile, avoiding the critical issues related to the fate of cells following transplantation. This review discusses the therapeutic potential of MSC-EVs in the treatment of neurodegenerative diseases, focusing on the strategies to further enhance their beneficial effects such as tracking methods, bioengineering applications, with particular attention to intranasal delivery as a feasible strategy to deliver MSC-EVs directly to the CNS in an effective and minimally invasive way. Current progresses and limiting issues to the extent of the use of MSC-EVs treatment for human neurodegenerative diseases will be also revised.

RNAseq analysis of olfactory neuroepithelium cytological samples in individuals with Down syndrome compared to euploid controls: a pilot study.

Down syndrome is a common genetic disorder caused by partial or complete triplication of chromosome 21. This syndrome shows an overall and progressive impairment of olfactory function, detected early in adulthood. The olfactory neuronal cells are located in the nasal olfactory mucosa and represent the first sensory neurons of the olfactory pathway. Herein, we applied the olfactory swabbing procedure to allow a gentle collection of olfactory epithelial cells in seven individuals with Down syndrome and in ten euploid controls. The aim of this research was to investigate the peripheral gene expression pattern in olfactory epithelial cells through RNAseq analysis. Validated tests (Sniffin' Sticks Extended test) were used to assess olfactory function. Olfactory scores were correlated with RNAseq results and cognitive scores (Vineland II and Leiter scales). All Down syndrome individuals showed both olfactory deficit and intellectual disability. Down syndrome individuals and euploid controls exhibited clear expression differences in genes located in and outside the chromosome 21. In addition, a significant correlation was found between olfactory test scores and gene expression, while a non-significant correlation emerged between olfactory and cognitive scores. This first preliminary step gives new insights into the Down syndrome olfactory system research, starting from the olfactory neuroepithelium, the first cellular step on the olfactory way.

Synergistic association of resveratrol and histone deacetylase inhibitors as treatment in amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease associated with motor neuron degeneration, progressive paralysis and finally death. Despite the research efforts, currently there is no cure for ALS. In recent years, multiple epigenetic mechanisms have been associated with neurodegenerative diseases. A pathological role for histone hypoacetylation and the abnormal NF-κB/RelA activation involving deacetylation of lysines, with the exclusion of lysine 310, has been established in ALS. Recent findings indicate that the pathological acetylation state of NF-κB/RelA and histone 3 (H3) occurring in the SOD1(G93A) murine model of ALS can be corrected by the synergistic combination of low doses of the AMP-activated kinase (AMPK)-sirtuin 1 pathway activator resveratrol and the histone deacetylase (HDAC) inhibitors MS-275 (entinostat) or valproate. The combination of the epigenetic drugs, by rescuing RelA and the H3 acetylation state, promotes a beneficial and sexually dimorphic effect on disease onset, survival and motor neurons degeneration. In this mini review, we discuss the potential of the epigenetic combination of resveratrol with HDAC inhibitors in the ALS treatment.

Ozone at low concentration modulates microglial activity in vitro: A multimodal microscopy and biomolecular study.

Oxygen-ozone (O2 -O3 ) therapy is an adjuvant/complementary treatment based on the activation of antioxidant and cytoprotective pathways driven by the nuclear factor erythroid 2-related factor 2 (Nrf2). Many drugs, including dimethyl fumarate (DMF), that are used to reduce inflammation in oxidative-stress-related neurodegenerative diseases, act through the Nrf2-pathway. The scope of the present investigation was to get a deeper insight into the mechanisms responsible for the beneficial result of O2 -O3 treatment in some neurodegenerative diseases. To do this, we used an integrated approach of multimodal microscopy (bright-field and fluorescence microscopy, transmission and scanning electron microscopy) and biomolecular techniques to investigate the effects of the low O3 concentrations currently used in clinical practice in lipopolysaccharide (LPS)-activated microglial cells human microglial clone 3 (HMC3) and in DMF-treated LPS-activated (LPS + DMF) HMC3 cells. The results at light and electron microscopy showed that LPS-activation induced morphological modifications of HMC3 cells from elongated/branched to larger roundish shape, cytoplasmic accumulation of lipid droplets, decreased electron density of the cytoplasm and mitochondria, decreased amount of Nrf2 and increased migration rate, while biomolecular data demonstrated that Heme oxygenase 1 gene expression and the secretion of the pro-inflammatory cytokines, Interleukin-6, and tumor necrosis factor-α augmented. O3 treatment did not affect cell viability, proliferation, and morphological features of both LPS-activated and LPS + DMF cells, whereas the cell motility and the secretion of pro-inflammatory cytokines were significantly decreased. This evidence suggests that modulation of microglia activity may contribute to the beneficial effects of the O2 -O3 therapy in patients with neurodegenerative disorders characterized by chronic inflammation. HIGHLIGHTS: Low-dose ozone (O3 ) does not damage activated microglial cells in vitro Low-dose O3 decreases cell motility and pro-inflammatory cytokine secretion in activated microglial cells in vitro Low-dose O3 potentiates the effect of an anti-inflammatory drug on activated microglial cells.

Beneficial and Sexually Dimorphic Response to Combined HDAC Inhibitor Valproate and AMPK/SIRT1 Pathway Activator Resveratrol in the Treatment of ALS Mice.

Amyotrophic lateral sclerosis (ALS) is a fatal adult-onset neurodegenerative disorder. There is no cure and current treatments fail to slow the progression of the disease. Epigenetic modulation in the acetylation state of NF-kB RelA and the histone 3 (H3) protein, involved in the development of neurodegeneration, is a drugable target for the class-I histone deacetylases (HDAC) inhibitors, entinostat or valproate, and the AMP-activated kinase (AMPK)-sirtuin 1 pathway activator, resveratrol. In this study, we demonstrated that the combination of valproate and resveratrol can restore the normal acetylation state of RelA in the SOD1(G93A) murine model of ALS, in order to obtain the neuroprotective form of NF-kB. We also investigated the sexually dimorphic development of the disease, as well as the sex-sensibility to the treatment administered. We showed that the combined drugs, which rescued AMPK activation, RelA and the histone 3 acetylation state, reduced the motor deficit and the disease pathology associated with motor neuron loss and microglial reactivity, Brain-Derived Neurotrophic Factor (BDNF) and B-cell lymphoma-extra large (Bcl-xL) level decline. Specifically, vehicle-administered males showed earlier onset and slower progression of the disease when compared to females. The treatment, administered at 50 days of life, postponed the time of onset in the male by 22 days, but not in a significant way in females. Nevertheless, in females, the drugs significantly reduced symptom severity of the later phase of the disease and prolonged the mice's survival. Only minor beneficial effects were produced in the latter stage in males. Overall, this study shows a beneficial and sexually dimorphic response to valproate and resveratrol treatment in ALS mice.

The transcriptional profile of adipose-derived stromal cells (ASC) mirrors the whitening of adipose tissue with age.

Multipotent stem cells persist within the stromal vascular fraction (SVF) of adipose tissue during adulthood. These cells, commonly referred to as adipose-derived stromal cells (ASC), have been extensively investigated over the past years as a promising therapeutic tool based on their regenerative and immunomodulatory properties. However, how ASC might mirror the age-related alteration of the fat they reside in remains unclear. Herein, we show that inguinal adipose tissue in mice turns from brown/beige- to white-like with age and resident ASC readily mirror these changes both at mRNA and microRNA transcriptional level. Mechanistically, our data suggest that these brown/age-related changes in ASC transcription rely on changes in the activity of E2F1 and NFkB transcription factors.

Interferon regulatory factor 7 impairs cellular metabolism in aging adipose-derived stromal cells.

Dysregulated immunity and widespread metabolic dysfunctions are the most relevant hallmarks of the passing of time over the course of adult life, and their combination at midlife is strongly related to increased vulnerability to diseases; however, the causal connection between them remains largely unclear. By combining multi-omics and functional analyses of adipose-derived stromal cells established from young (1 month) and midlife (12 months) mice, we show that an increase in expression of interferon regulatory factor 7 (IRF7) during adult life drives major metabolic changes, which include impaired mitochondrial function, altered amino acid biogenesis and reduced expression of genes involved in branched-chain amino acid (BCAA) degradation. Our results draw a new paradigm of aging as the 'sterile' activation of a cell-autonomous pathway of self-defense and identify a crucial mediator of this pathway, IRF7, as driver of metabolic dysfunction with age.

ASC-Exosomes Ameliorate the Disease Progression in SOD1(G93A) Murine Model Underlining Their Potential Therapeutic Use in Human ALS.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive degeneration of motoneurons. To date, there is no effective treatment available. Exosomes are extracellular vesicles that play important roles in intercellular communication, recapitulating the effect of origin cells. In this study, we tested the potential neuroprotective effect of exosomes isolated from adipose-derived stem cells (ASC-exosomes) on the in vivo model most widely used to study ALS, the human SOD1 gene with a G93A mutation (SOD1(G93A)) mouse. Moreover, we compared the effect of two different routes of exosomes administration, intravenous and intranasal. The effect of exosomes administration on disease progression was monitored by motor tests and analysis of lumbar motoneurons and glial cells, neuromuscular junction, and muscle. Our results demonstrated that repeated administration of ASC-exosomes improved the motor performance; protected lumbar motoneurons, the neuromuscular junction, and muscle; and decreased the glial cells activation in treated SOD1(G93A) mice. Moreover, exosomes have the ability to home to lesioned ALS regions of the animal brain. These data contribute by providing additional knowledge for the promising use of ASC-exosomes as a therapy in human ALS.

ASCs-Exosomes Recover Coupling Efficiency and Mitochondrial Membrane Potential in an in vitro Model of ALS.

The amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by motoneurons death. Mutations in the superoxide dismutase 1 (SOD1) protein have been identified to be related to the disease. Beyond the different altered pathways, the mitochondrial dysfunction is one of the major features that leads to the selective death of motoneurons in ALS. The NSC-34 cell line, overexpressing human SOD1(G93A) mutant protein [NSC-34(G93A)], is considered an optimal in vitro model to study ALS. Here we investigated the energy metabolism in NSC-34(G93A) cells and in particular the effect of the mutated SOD1(G93A) protein on the mitochondrial respiratory capacity (complexes I-IV) by high resolution respirometry (HRR) and cytofluorimetry. We demonstrated that NSC-34(G93A) cells show a reduced mitochondrial oxidative capacity. In particular, we found significant impairment of the complex I-linked oxidative phosphorylation, reduced efficiency of the electron transfer system (ETS) associated with a higher rate of dissipative respiration, and a lower membrane potential. In order to rescue the effect of the mutated SOD1 gene on mitochondria impairment, we evaluated the efficacy of the exosomes, isolated from adipose-derived stem cells, administrated on the NSC-34(G93A) cells. These data show that ASCs-exosomes are able to restore complex I activity, coupling efficiency and mitochondrial membrane potential. Our results improve the knowledge about mitochondrial bioenergetic defects directly associated with the SOD1(G93A) mutation, and prove the efficacy of adipose-derived stem cells exosomes to rescue the function of mitochondria, indicating that these vesicles could represent a valuable approach to target mitochondrial dysfunction in ALS.

The Anti-Apoptotic Effect of ASC-Exosomes in an In Vitro ALS Model and Their Proteomic Analysis.

Stem cell therapy represents a promising approach in the treatment of several neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS). The beneficial effect of stem cells is exerted by paracrine mediators, as exosomes, suggesting a possible potential use of these extracellular vesicles as non-cell based therapy. We demonstrated that exosomes isolated from adipose stem cells (ASC) display a neuroprotective role in an in vitro model of ALS. Moreover, the internalization of ASC-exosomes by the cells was shown and the molecules and the mechanisms by which exosomes could exert their beneficial effect were addressed. We performed for the first time a comprehensive proteomic analysis of exosomes derived from murine ASC. We identified a total of 189 proteins and the shotgun proteomics analysis revealed that the exosomal proteins are mainly involved in cell adhesion and negative regulation of the apoptotic process. We correlated the protein content to the anti-apoptotic effect of exosomes observing a downregulation of pro-apoptotic proteins Bax and cleaved caspase-3 and upregulation of anti-apoptotic protein Bcl-2 α, in an in vitro model of ALS after cell treatment with exosomes. Overall, this study shows the neuroprotective effect of ASC-exosomes after their internalization and their global protein profile, that could be useful to understand how exosomes act, demonstrating that they can be employed as therapy in neurodegenerative diseases.

Neuroinflammatory Response in Chronic Hydrocephalus in Juvenile Rats.

Hydrocephalus is especially prevalent in countries with limited resources, where its treatment is still a challenge. However, long-term neuropathological changes in untreated hydrocephalus remain largely unexplored. The present study looks at cortical parenchyma and neuroinflammation in acquired, chronic hydrocephalus. Intracisternal kaolin injections were performed in 3-week-old rats, followed by -1, 4- and 8-week survival; matched control rats received saline injections. Ventriculomegaly has been previously reported to stabilize by the third week in this model. Single and triple immunocytochemical approaches were used to highlight neurones, astrocytes, microglia, and the pro-inflammatory cytokine interleukin (IL)-1ß in the parietal cortex, utilizing cell counts and densitometry. Microglial protein ionized calcium binding adaptor molecule 1 (Iba1) and IL-1ß expressions were monitored with Western blotting in the parietal cortex and hippocampus. In the parietal cortex, which showed progressive disruption of cytoarchitecture, neuronal density was significantly increased at 8weeks post-induction but not at earlier time points, indicating on-going cortical damage in chronic hydrocephalus. Astrocyte and microglia hypertrophy, and Iba1 expression indicated glial cell activation which peaked at 4weeks. IL-1ß expression also peaked at 4weeks and was then down-regulated. Overall the findings indicate that neuroinflammatory features build up in the first month after hydrocephalus induction implicating marked IL-1ß upregulation. The data also show that astrocytes are the main source of IL-1ß in this disorder.

Acetylation state of RelA modulated by epigenetic drugs prolongs survival and induces a neuroprotective effect on ALS murine model.

Dysregulation in acetylation homeostasis has been implicated in the pathogenesis of the amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disorder. It is known that the acetylation of transcriptional factors regulates their activity. The acetylation state of NF-kB RelA has been found to dictate the neuroprotective versus the neurotoxic effect of p50/RelA. Here we showed that the pro-apoptotic acetylation mode of RelA, involving a general lysine deacetylation of the subunit with the exclusion of the lysine 310, is evident in the lumbar spinal cord of SOD1(G93A) mice, a murine model of ALS. The administration of the HDAC inhibitor MS-275 and the AMPK/sirtuin 1 activator resveratrol restored the normal RelA acetylation in SOD1(G93A) mice. The SOD1(G93A) mice displayed a 3 weeks delay of the disease onset, associated with improvement of motor performance, and 2 weeks increase of lifespan. The epigenetic treatment rescued the lumbar motor neurons affected in SOD1(G93A) mice, accompanied by increased levels of protein products of NF-kB-target genes, Bcl-xL and brain-derived neurotrophic factor. In conclusion, we here demonstrate that MS-275 and resveratrol restore the acetylation state of RelA in the spinal cord, delaying the onset and increasing the lifespan of SOD1(G93A) mice.

A microRNA signature from serum exosomes of patients with glioma as complementary diagnostic biomarker.

Malignant gliomas, the most frequent primary brain tumors, are characterized by a dismal prognosis. Reliable biomarkers complementary to neuroradiology in the differential diagnosis of gliomas and monitoring for post-surgical progression are unmet needs. Altered expression of several microRNAs in tumour tissues from patients with gliomas compared to normal brain tissue have been described, thus supporting the rationale of using microRNA-based biomarkers. Although different circulating microRNAs were proposed in association with gliomas, they have not been introduced into clinical practice so far. Blood samples were collected from patients with high and low grade gliomas, both before and after surgical resection, and the expression of miR-21, miR-222 and miR-124-3p was measured in exosomes isolated from serum. The expression levels of miR-21, miR-222 and miR-124-3p in serum exosomes of patients with high grade gliomas were significantly higher than those of low grade gliomas and healthy controls and were sharply decreased in samples obtained after surgery. The analysis of miR-21, miR-222 and miR-124-3p in serum exosomes of patients affected by gliomas can provide a minimally invasive and innovative tool to help the differential diagnosis of gliomas at their onset in the brain and predict glioma grading and non glial metastases before surgery.

MRI reveals therapeutical efficacy of stem cells: An experimental study on the SOD1(G93A) animal model.

PURPOSE: The first part of the experiment identifies and validates MRI biomarkers distinctive of the disease progression in the transgenic superoxide dismutase gene (SOD1(G93A)) animal model. The second part assesses the efficacy of a mesenchymal stem cell-based therapy through the MRI biomarkers previously defined. METHODS: The first part identifies MRI differences between SOD1(G93A) and healthy mice. The second part of the experiment follows the disease evolution of stem cell-treated and non-stem-cell treated SOD1(G93A) mice. The analysis focused on voxel-based morphometry and T2 mapping on the brain tissues, and T2-weighted imaging and diffusion tensor imaging (DTI) on the hind limbs. RESULTS: Comparing diseased mice to healthy control revealed gray matter alterations in the brainstem area, accompanied by increased T2 relaxation time. Differences in muscle volume, muscle signal intensity, fractional anisotropy, axial diffusivity, and radial diffusivity were measured in the hind limbs. In the comparison between stem cell-treated mice and nontreated ones, differences in muscle volume, muscle signal intensity, and DTI-derived maps were found. CONCLUSION: MRI-derived biomarkers can be used to identify differences between stem cell-treated and nontreated SOD1(G93A) mice. Magn Reson Med 79:459-469, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

Theranostic Role of 32P-ATP as Radiopharmaceutical for the Induction of Massive Cell Death within Avascular Tumor Core.

Drug inaccessibility to vast areas of the tumor parenchyma is amongst the major hurdles for conventional therapies. Treatment efficacy rapidly decreases with distance from vessels and most of the tumor cells survive therapy. Also, between subsequent cycles of treatment, spared cancer cells replace those killed near the vessels, improving their access to nutrients, boosting their proliferation rate, and thus enabling tumor repopulation. Because of their property of "acting at a distance," radioisotopes are believed to overcome the physical barrier of vascular inaccessibility. Methods A novel molecular imaging tool called Cerenkov Luminescence Imaging (CLI) was employed for the detection of Cerenkov radiation emitted by beta particles, allowing in vivo tracking of beta-emitters. More precisely we investigated using a xenograft model of colon carcinoma the potential use of 32P-ATP as a novel theranostic radiopharmaceutical for tracing tumor lesions while simultaneously hampering their growth. Results Our analyses demonstrated that 32P-ATP injected into tumor-bearing mice reaches tumor lesions and persists for days and weeks within the tumor parenchyma. Also, the high-penetrating beta particles of 32P-ATP exert a "cross-fire" effect that induces massive cell death throughout the entire tumor parenchyma including core regions. Conclusion Our findings suggest 32P-ATP treatment as a potential approach to complement conventional therapies that fail to reach the tumor core and to prevent tumor repopulation.

Labeling and Magnetic Resonance Imaging of Exosomes Isolated from Adipose Stem Cells.

Adipose stem cells (ASC) represent a promising therapeutic approach for neurodegenerative diseases. Most biological effects of ASC are probably mediated by extracellular vesicles, such as exosomes, which influence the surrounding cells. Current development of exosome therapies requires efficient and noninvasive methods to localize, monitor, and track the exosomes. Among imaging methods used for this purpose, magnetic resonance imaging (MRI) has advantages: high spatial resolution, rapid in vivo acquisition, and radiation-free operation. To be detectable with MRI, exosomes must be labeled with MR contrast agents, such as ultra-small superparamagnetic iron oxide nanoparticles (USPIO). Here, we set up an innovative approach for exosome labeling that preserves their morphology and physiological characteristics. We show that by labeling ASC with USPIO before extraction of nanovesicles, the isolated exosomes retain nanoparticles and can be visualized by MRI. The current work aims at validating this novel USPIO-based exosome labeling method by monitoring the efficiency of the labeling with MRI both in ASC and in exosomes. © 2017 by John Wiley & Sons, Inc.

Regional Myelin and Axon Damage and Neuroinflammation in the Adult Mouse Brain After Long-Term Postnatal Vanadium Exposure.

Environmental exposure to vanadium occurs in areas of persistent burning of fossil fuels; this metal is known to induce oxidative stress and oligodendrocyte damage. Here, we determined whether vanadium exposure (3 mg/kg) in mice during the first 3 postnatal months leads to a sustained neuroinflammatory response. Body weight monitoring, and muscle strength and open field tests showed reduction of body weight gain and locomotor impairment in vanadium-exposed mice. Myelin histochemistry and immunohistochemistry for astrocytes, microglia, and nonphosphorylated neurofilaments revealed striking regional heterogeneity. Myelin damage involved the midline corpus callosum and fibers in cortical gray matter, hippocampus, and diencephalon that were associated with axonal damage. Astrocyte and microglial activation was identified in the same regions and in the internal capsule; however, no overt myelin and axon damage was observed in the latter. Double immunofluorescence revealed induction of high tumor necrosis factor (TNF) immunoreactivity in reactive astrocytes. Western blotting analysis showed significant induction of TNF and interleukin-1ß expression. Together these findings show that chronic postnatal vanadium exposure leads to functional deficit and region-dependent myelin damage that does not spare axons. This injury is associated with glial cell activation and proinflammatory cytokine induction, which may reflect both neurotoxic and neuroprotective responses.