Raman spectral analysis of the brainstem and responses of neuroglia and cytokines in whole-body gamma-irradiated rats after administration of aminothiol-based radioprotector GL2011

The search for an effective and non-toxic radioprotector is ongoing. We tested a novel, natural aminothiol-based radioprotector, GL2011, that was applied 30 min, 3 h or 6 h after the exposure of male albino Wistar rats to a 6.7 Gy mild dose of gamma radiation. The molecular signatures of radioprotection were investigated with Raman microspectroscopy of brainstem tissue samples. Morphological changes and activation of astrocytes and microglia were assessed by immunohistochemistry. Global markers of neuroinflammation were followed by ELISA to monitor blood plasma levels of proinflammatory (IL-6 and TNF-α) and anti-inflammatory (IL-10) cytokines. A thirty-day follow-up determined survival of unprotected animals 37.5%. A survival increase was observed after radioprotection (75%, irrespective of the time of application). Raman spectra revealed a slightly deleterious effect of radiation on nucleic acids in surviving animals that was mitigated with the radioprotector, as GL2011 preserved the morphology of both astrocytes and microglia, with reduced microglial infiltration. Cytokine assessment revealed an immunomodulatory effect of the novel radioprotector. The overall results point out the positive effects of a single dose of GL2011 applied at different times. The molecular and cellular changes in the brainstem indicate that the radioprotector applied after radiation conferred better protection, which underlines its translation to cure radiation accidents

Increased survival after irradiation followed by regeneration of bone marrow stromal cells with a novel thiol-based radioprotector

Aim To investigate the survival of laboratory rats after irradiation and to study the cellularity of their bone marrow and the multipotential mesenchymal stem cells (BM-MSCs) in groups treated with or without a new thiol-based radioprotector (GM2011) Methods Animals were irradiated by a Cobalt gamma source at 6.7 Gy. Treated animals were given i.p. GM2011 30 minutes before and 3 and 7 hours after irradiation. Controls consisted of sham irradiated animals without treatment and animals treated without irradiation. After 30 days post-irradiation, animals were sacrificed and bone marrow cells were prepared from isolated femurs. A colony forming unit-fibroblast (CFU-F) assay was performed to obtain the number of BM-MSCs. Results In the treated group, 87% of animals survived, compared to only 30% in the non-treated irradiated group. Irradiation induced significant changes in the bone marrow of the treated rats (total bone marrow cellularity was reduced by similar to 60% - from 63 to 28 cells x10(6)/femur and the frequency of the CFU-F per femur by similar to 70% - from 357 to 97), however GL2011 almost completely prevented the suppressive effect observed on day 30 post-irradiation (71 cells x 10(6)/femur and 230 CFU-F/femur). Conclusion Although the irradiation dosage was relatively high, GL2011 acted as a very effective new radioprotector. The recovery of the BN-MSCs and their counts support the effectiveness of the studied radioprotector

Decreased Expression of Alpha1 Subunit of Na(+)/K+-Atpase in the Als Rat Brain

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Decreased Expression of Alpha1 Subunit of Na(+)/K+-Atpase in the Als Rat Brain

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Tenascins and inflammation in disorders of the nervous system

In vitro and in vivo studies on the role of tenascins have shown that the two paradigmatic glycoproteins of the tenascin family, tenascin-C (TnC) and tenascin-R (TnR) play important roles in cell proliferation and migration, fate determination, axonal pathfinding, myelination, and synaptic plasticity. As components of the extracellular matrix, both molecules show distinct, but also overlapping dual functions in inhibiting and promoting cell interactions depending on the cell type, developmental stage and molecular microenvironment. They are expressed by neurons and glia as well as, for TnC, by cells of the immune system. The functional relationship between neural and immune cells becomes relevant in acute and chronic nervous system disorders, in particular when the blood brain and blood peripheral nerve barriers are compromised. In this review, we will describe the functional parameters of the two molecules in cell interactions during development and, in the adult, in synaptic activity and plasticity, as well as regeneration after injury, with TnC being conducive for regeneration and TnR being inhibitory for functional recovery. Although not much is known about the role of tenascins in neuroinflammation, we will describe emerging knowledge on the interplay between neural and immune cells in autoimmune diseases, such as multiple sclerosis and polyneuropathies. We will attempt to point out the directions of experimental approaches that we envisage would help gaining insights into the complex interplay of TnC and TnR with the cells that express them in pathological conditions of nervous and immune systems.MESRS [III41005, ON 173035, ON 173013]; German Research Foundation; New Jersey Commission for Spinal Cord Research; Li Ka-Shing Foundatio

Tenascins and inflammation in disorders of the nervous system

In vitro and in vivo studies on the role of tenascins have shown that the two paradigmatic glycoproteins of the tenascin family, tenascin-C (TnC) and tenascin-R (TnR) play important roles in cell proliferation and migration, fate determination, axonal pathfinding, myelination, and synaptic plasticity. As components of the extracellular matrix, both molecules show distinct, but also overlapping dual functions in inhibiting and promoting cell interactions depending on the cell type, developmental stage and molecular microenvironment. They are expressed by neurons and glia as well as, for TnC, by cells of the immune system. The functional relationship between neural and immune cells becomes relevant in acute and chronic nervous system disorders, in particular when the blood brain and blood peripheral nerve barriers are compromised. In this review, we will describe the functional parameters of the two molecules in cell interactions during development and, in the adult, in synaptic activity and plasticity, as well as regeneration after injury, with TnC being conducive for regeneration and TnR being inhibitory for functional recovery. Although not much is known about the role of tenascins in neuroinflammation, we will describe emerging knowledge on the interplay between neural and immune cells in autoimmune diseases, such as multiple sclerosis and polyneuropathies. We will attempt to point out the directions of experimental approaches that we envisage would help gaining insights into the complex interplay of TnC and TnR with the cells that express them in pathological conditions of nervous and immune systems.MESRS [III41005, ON 173035, ON 173013]; German Research Foundation; New Jersey Commission for Spinal Cord Research; Li Ka-Shing Foundatio

Relevance of the ability of fructose 1,6-bis(phosphate) to sequester ferrous but not ferric ions

The cytoprotective activity of F16BP has been documented in severe conditions such as convulsions, reperfusion injury, septic shock, diabetic complications, hypothermia-induced injury, UV-provoked skin damage and in other processes including apoptosis and excitotoxicity. F16BP shows very efficient cytoprotective activity in astroglial cells exposed to H2O2-provoked oxidative stress and during neuronal injury caused by hypoxic conditions. As most of the aforementioned processes involve iron activity-related conditions, we investigated the ferric and ferrous iron binding properties of F16BP under physiological conditions using P-31 NMR and EPR spectroscopy. Our results indicate that cytoprotective F16BP activity is predominantly based on ferrous iron sequestration. P-31 NMR spectroscopy of F16BP employing paramagnetic properties of iron clearly showed that F16BP forms stabile complexes with Fe2+ which was verified by EPR of another divalent cation-Mn2+. On the other hand, F16BP does not sequester ferric iron nor does it increase its redox activity as shown by P-31 NMR and EPR spin-trapping. Therefore, F16BP may be beneficial in neurodegenerative and other conditions that are characterised by ferric iron stores and deposits

Changes in the astrocytic aquaporin-4 and inwardly rectifying potassium channel expression in the brain of the amyotrophic lateral sclerosis SOD1G93A rat model

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease affecting upper and lower motor neurons. Dysfunction and death of motor neurons are closely related to the modified astrocytic environment. Astrocytic endfeet, lining the bloodbrain barrier (BBB), are enriched in two proteins, aquaporin-4 (AQP4) and inwardly rectifying potassium channel (Kir) 4.1. Both channels are important for the maintainance of a functional BBB astrocytic lining. In this study, expression levels of AQP4 and Kir4.1 were for the first time examined in the brainstem and cortex, along with the functional properties of Kir channels in cultured cortical astrocytes of the SOD1G93A rat model of ALS. Western blot analysis showed increased expression of AQP4 and decreased expression of Kir4.1 in the brainstem and cortex of the ALS rat. In addition, higher immunoreactivity of AQP4 and reduced immunolabeling of Kir4.1 in facial and trigeminal nuclei as well as in the motor cortex were also observed. Particularly, the observed changes in the expression of both channels were retained in cultured astrocytes. Furthermore, whole-cell patch-clamp recordings from cultured ALS cortical astrocytes showed a significantly lower Kir current density. Importantly, the potassium uptake current in ALS astrocytes was significantly reduced at all extracellular potassium concentrations. Consequently, the Kir-specific Cs+- and Ba2+-sensitive currents were also decreased. The changes in the studied channels, notably at the upper CNS level, could underline the hampered ability of astrocytes to maintain water and potassium homeostasis, thus affecting the BBB, disturbing the neuronal microenvironment, and causing motoneuronal dysfunction and death. (c) 2012 Wiley Periodicals, Inc.Ministry of Education and Science Republic of Serbia [41005

The Demise of the Blood-Brain Barrier in Amyotrophic Lateral Sclerosis and the Role of Astrocytes

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