Reactivation of nucleases with peroxidation damages induced by a menadione: ascorbate combination devastates human prostate carcinomas: ultrastructural aspects.

INTRODUCTION: Xenografts of androgen-independent human DU145 prostate metastatic carcinomas implanted in nu/nu male mice have revealed a significant survival after a prooxidant anticancer treatment consisting of a combination of menadione bisulfite and sodium ascorbate (VK3:VC). METHODS: Implanted samples of diaphragm carcinomas from longest survived mice from either oral, intraperitoneal (IP), or both oral and IP treatment groups were assessed with light, scanning, and transmission electron microscopy to analyze morphologic damages. RESULTS: Compared with previous fine structure data of in vitro untreated carcinomas, the changes induced by oral, IP, and oral with IP VK3:VC treatment dismantled those xenografts with autoschizis, and necrotic atrophy was accomplished by cell's oxidative stress whose injuries were consequent to reactivated deoxyribonucleases and ribonucleases. Tumor destructions resulted from irreversible damages of nucleus components, endoplasmic reticulum, and mitochondria there. Other alterations included those of the cytoskeleton that resulted in characteristic self-excisions named " autoschizis." All these injuries lead resilient cancer cells to necrotic cell death. CONCLUSION: The fine structure damages caused by VK3:VC prooxidant combination in the human DU145 prostate xenografts confirmed those shown in vitro and of other cell lines with histochemistry and biomolecular investigations. These devastations incurred without damage to normal tissues; thus, our data brought support for the above combination to assist in the treatment of prostate cancers and other cancers.

Loss of Ephaptic Contacts in the Murine Thalamus during Osmotic Demyelination Syndrome.

BACKGROUND AND AIM: A murine model mimicking osmotic demyelination syndrome (ODS) revealed with histology in the relay posterolateral (VPL) and ventral posteromedial (VPM) thalamic nuclei adjoined nerve cell bodies in chronic hyponatremia, amongst the damaged 12 h and 48 h after reinstatement of osmolality. This report aims to verify and complement with ultrastructure other neurophysiology, immunohistochemistry, and molecular biochemistry data to assess the connexin-36 protein, as part of those hinted close contacts.This ODS investigation included four groups of mice: Sham (NN; n = 13), hyponatremic (HN; n = 11), those sacrificed 12 h after a fast restoration of normal natremia (ODS12h; n = 6) and mice sacrificed 48 h afterward, or ODS48 h (n = 9). Out of these, thalamic zones samples included NN (n = 2), HN (n = 2), ODS12h (n = 3) and ODS48h (n = 3). RESULTS: Ultrastructure illustrated junctions between nerve cell bodies that were immunolabeled with connexin36 (Cx36) with light microscopy and Western blots. These cell's junctions were reminiscent of low resistance junctions characterized in other regions of the CNS with electrophysiology. Contiguous neurons showed neurolemma contacts in intact and damaged tissues according to their location in the ODS zones, at 12 h and 48 h post correction along with other demyelinating alterations. Neurons and ephaptic contact measurements indicated the highest alterations, including nerve cell necrosis in the ODS epicenter and damages decreased toward the outskirts of the demyelinated zone. CONCLUSION: Ephapses contained C × 36between intact or ODS injured neurons in the thalamus appeared to be resilient beyond the core degraded tissue injuries. These could maintain intercellular ionic and metabolite exchanges between these lesser injured regions and, thus, would partake to some brain plasticity repairs.

Thalamic Neuron Resilience during Osmotic Demyelination Syndrome (ODS) Is Revealed by Primary Cilium Outgrowth and ADP-ribosylation factor-like protein 13B Labeling in Axon Initial Segment.

A murine osmotic demyelinating syndrome (ODS) model was developed through chronic hyponatremia, induced by desmopressin subcutaneous implants, followed by precipitous sodium restoration. The thalamic ventral posterolateral (VPL) and ventral posteromedial (VPM) relay nuclei were the most demyelinated regions where neuroglial damage could be evidenced without immune response. This report showed that following chronic hyponatremia, 12 h and 48 h time lapses after rebalancing osmolarity, amid the ODS-degraded outskirts, some resilient neuronal cell bodies built up primary cilium and axon hillock regions that extended into axon initial segments (AIS) where ADP-ribosylation factor-like protein 13B (ARL13B)-immunolabeled rod-like shape content was revealed. These AIS-labeled shaft lengths appeared proportional with the distance of neuronal cell bodies away from the ODS damaged epicenter and time lapses after correction of hyponatremia. Fine structure examination verified these neuron abundant transcriptions and translation regions marked by the ARL13B labeling associated with cell neurotubules and their complex cytoskeletal macromolecular architecture. This necessitated energetic transport to organize and restore those AIS away from the damaged ODS core demyelinated zone in the murine model. These labeled structures could substantiate how thalamic neuron resilience occurred as possible steps of a healing course out of ODS.

A primary cilium in oligodendrocytes: a fine structure signal of repairs in thalamic Osmotic Demyelination Syndrome (ODS).

A murine osmotic demyelination syndrome (ODS) model of the central nervous system included the relay thalamic ventral posterolateral (VPL) and ventral posteromedial (VPM) nuclei. Morphologic comparisons between treatments have revealed oligodendrocyte changes and, already 12 hours following the osmolality restoration, some heavily contrasted oligodendrocytes formed a unique intracellular primary cilium. This unique structure, found in vivo, in mature CNS oligodendrocytes, could account for a local awakening of some of the developmental proteome as it can be expressed in oligodendrocyte precursor cells. This resilience accompanied the emergence of arl13b protein expression along with restoration of nerve cell body axon hillocks shown in a previous issue of this journal. Additionally, the return of several thalamic oligodendrocyte fine features (nucleus, organelles) was shown 36 h later, including some mitosis. Those cell restorations and recognized translational activities comforted that local repairs could again take place, due to oligodendrocyte resilience after ODS instead or added to a postulated immigration of oligodendrocyte precursor cells distant from the sites of myelinolysis.

Leptin receptor defect with diabetes causes skeletal muscle atrophy in female obese Zucker rats where peculiar depots networked with mitochondrial damages.

Tibialis anterior muscles of 45-week-old female obese Zucker rats with defective leptin receptor and non-insulin dependent diabetes mellitus (NIDDM) showed a significative atrophy compared to lean muscles, based on histochemical-stained section's measurements in the sequence: oxidative slow twitch (SO, type I) < oxidative fast twitch (FOG, type IIa) < fast glycolytic (FG, type IIb). Both oxidative fiber's outskirts resembled 'ragged' fibers and, in these zones, ultrastructure revealed small clusters of endoplasm-like reticulum filled with unidentified electron contrasted compounds, contiguous and continuous with adjacent mitochondria envelope. The linings appeared crenated stabbed by circular patterns resembling those found of ceramides. The same fibers contained scattered degraded mitochondria that tethered electron contrasted droplets favoring larger depots while mitoptosis were widespread in FG fibers. Based on other interdisciplinary investigations on the lipid depots of diabetes 2 muscles made us to propose these accumulated contrasted contents to be made of peculiar lipids, including acyl-ceramides, as those were only found while diabetes 2 progresses in aging obese rats. These could interfere in NIDDM with mitochondrial oxidative energetic demands and muscle functions.

The osmotic demyelination syndrome: the resilience of thalamic neurons is verified with transmission electron microscopy.

The development of a murine model of osmotic demyelinating syndrome (ODS) allowed to study changes incurred in extrapontine zones of the CNS and featured neuron and glial cell changes in the relay thalamic ventral posterolateral (VPL) and ventral posteromedial (VPM) nuclei before, during and after ODS induction, and characterized without immune response. There, the neuron Wallerian-type deteriorations were verified with fine structure modifications of the neuron cell body, including some nucleus topology and its nucleolus changes. Morphologic analyses showed a transient stoppage of transcriptional activities while myelinated axons in the surrounding neuropil incurred diverse damages, previously reported. Even though the regional thalamus myelin deterioration was clearly recognized with light microscopy 248 h after osmotic recovery of ODS, ultrastructure analyses demonstrated that, at that time, the same damaged parenchyma regions contained nerve cell bodies that have already reactivated nucleus transcriptions and neuroplasm translations because peculiar accumulations of fibro-granular materials, similar to those detected in restored ODS astrocytes, were revealed in these restructuring nerve cell bodies. Their aspects suggested to be accumulations of ribonucleoproteins. The findings suggested that progressive neural function's recovery in the murine model could imitate some aspects of human ODS recovery cases.

Osmotic Demyelination: From an Oligodendrocyte to an Astrocyte Perspective.

Osmotic demyelination syndrome (ODS) is a disorder of the central myelin that is often associated with a precipitous rise of serum sodium. Remarkably, while the myelin and oligodendrocytes of specific brain areas degenerate during the disease, neighboring neurons and axons appear unspoiled, and neuroinflammation appears only once demyelination is well established. In addition to blood‒brain barrier breakdown and microglia activation, astrocyte death is among one of the earliest events during ODS pathology. This review will focus on various aspects of biochemical, molecular and cellular aspects of oligodendrocyte and astrocyte changes in ODS-susceptible brain regions, with an emphasis on the crosstalk between those two glial cells. Emerging evidence pointing to the initiating role of astrocytes in region-specific degeneration are discussed.

Regional oligodendrocytopathy and astrocytopathy precede myelin loss and blood-brain barrier disruption in a murine model of osmotic demyelination syndrome.

The osmotic demyelination syndrome (ODS) is a non-primary inflammatory disorder of the central nervous system myelin that is often associated with a precipitous rise of serum sodium concentration. To investigate the physiopathology of ODS in vivo, we generated a novel murine model based on the abrupt correction of chronic hyponatremia. Accordingly, ODS mice developed impairments in brainstem auditory evoked potentials and in grip strength. At 24 hr post-correction, oligodendrocyte markers (APC and Cx47) were downregulated, prior to any detectable demyelination. Oligodendrocytopathy was temporally and spatially correlated with the loss of astrocyte markers (ALDH1L1 and Cx43), and both with the brain areas that will develop demyelination. Oligodendrocytopathy and astrocytopathy were confirmed at the ultrastructural level and culminated with necroptotic cell death, as demonstrated by pMLKL immunoreactivity. At 48 hr post-correction, ODS brains contained pathognomonic demyelinating lesions in the pons, mesencephalon, thalamus and cortical regions. These damages were accompanied by blood-brain barrier (BBB) leakages. Expression levels of IL-1ß, FasL, TNFRSF6 and LIF factors were significantly upregulated in the ODS lesions. Quiescent microglial cells type A acquired an activated type B morphology within 24 hr post-correction, and reached type D at 48 hr. In conclusion, this murine model of ODS reproduces the CNS demyelination observed in human pathology and indicates ambiguous causes that is regional vulnerability of oligodendrocytes and astrocytes, while it discards BBB disruption as a primary cause of demyelination. This study also raises new queries about the glial heterogeneity in susceptible brain regions as well as about the early microglial activation associated with ODS.

The leptin receptor mutation of the obese Zucker rat causes sciatic nerve demyelination with a centripetal pattern defect.

Young male Zucker rats with a leptin receptor mutation are obese, have a non-insulin-dependent diabetes mellitus (NIDDM), and other endocrinopathies. Tibial branches of the sciatic nerve reveal a progressive demyelination that progresses out of the Schwann cells (SCs) where electron-contrast deposits are accumulated while the minor lines or intermembranous SC contacts display exaggerated spacings. Cajal bands contain diversely contrasted vesicles adjacent to the abaxonal myelin layer with blemishes; they appear dispatched centripetally out of many narrow electron densities, regularly spaced around the myelin annulus. These anomalies widen and yield into sectors across the stacked myelin layers. Throughout the worse degradations, the adaxonal membrane remains along the axonal neuroplasm. This peripheral neuropathy with irresponsive leptin cannot modulate hypothalamic-pituitary-adrenal axis and SC neurosteroids, thus exacerbates NIDDM condition. Additionally, the ultrastructure of the progressive myelin alterations may have unraveled a peculiar, centripetal mode of trafficking maintenance of the peripheral nervous system myelin, while some adhesive glycoproteins remain between myelin layers, somewhat hindering the axon mutilation. Heading title: Peripheral neuropathy and myelin.

Formation of intracellular lumina in human prostate carcinoma (DU145) cells, maturation into signet cells, and the cribriform morphology of tumors.

The intracellular or intracytoplasmic lumen (IL) is an enigmatic histological structure that occurs in various tumor cells. A reassessment of diverse ILs fine-structure micrographs obtained out of previous studies encompassing the human prostate carcinoma (DU145) cell line and xenotransplanted carcinomas enabled us to propose aspects of ILs development in cancer cells: a combination of altered expressions in intercellular contacts and their cytoskeletal components would favor a disarray of self-apical polarity orientation; those defects, associated with a local, entwined enriched membranous structures growing as microvilli-like formations out of a disrupted endoplasm and trans-Golgi sorting, create ILs in cells' perikarya. These misplaced intracytoplasmic domains can become enlarged through spaces made between the finger-like structures by accruing membranes of coalescent intracytoplasmic vesicles then adding microvilli and glycocalyx to constitute ILs. Cationic mucins added with or without a progressive or total loss of microvilli and content generate signet or ring cell, while ILs enlarge. Variable build-ups of these cells' populations in carcinomas result in architectural mix-up of adjacent cells around these voids, misconstrued as new lumen, and establish a "cribriform" tumor pattern that often implies a poor cancer prognosis. Alternatively, cytotoxic changes caused by anticancer pro-oxidant treatment favor membrane alterations and exaggerate the ILs in xenotransplants into intracellular crypts that accompany other tumor degenerative changes.

Modes of internalizations of human prostate carcinoma (DU145) cells in vitro and in murine xenotransplants.

Ultrastructural data compiled from DU145 human prostate carcinoma cells growing in vivo and, more often in vitro or after treatment by pro-oxidant reactants, can induce and encompass several processes of cell internalization or entosis. These events were observed after tumor cells were essentially undergoing autoschizic injuries and other cell deaths without externalization of phosphatidylserine. Based on other previous observations made on DU145 cells, one hypothesizes that, as a means of survival, tumor cells find sources of nutrients through phagocytosis of apparently intact, injured cells, corpses, and cell debris by cannibalism. These peculiar activities occurred sporadically, in a small population of cells and could be dictated by their widely adapted energetic metabolism, now impaired, either due to the location of the cells in the growing tumors or in vitro as a result of this pro-oxidant anticancer treatment causing damage and abolishing their adapted metabolism.

Crinophagy in Thyroid Follicular and Parafollicular Cells of Male Obese Zucker Rat.

Comparison between lean (Fa/?) and obese (fa/fa) young adult male Zucker rat thyroids reveals that obese rats display larger clusters of parafollicular cells than the lean ones with a lesser blood supply. Fa/? thyroid typically shows single or "twin" C cells in follicles; fa/fa parafollicular cells appear with three functional aspects. Crinophagy is found in the fa/fa C cells amassing numerous aberrant calcitonin-containing vesicles among which lysosomes build these autophagic bodies by capturing vesicle contents, other organelles and, fusing with each other, increase their size. Other C cells contain many secretory vesicles but show few or no crinophagic structures. Another parafollicular cell type is revealed with scant organelles and highly contrasted secretory vesicles, different from calcitonin. Hypercalcemia of fa/fa rats corresponds to increased C cells population with accrued calcitonin production but a low calcitonin plasma level - verified by others - is likely caused by crinophagy of the altered vesicles. In addition, the T thyrocytes of fa/fa rats exhibit crinophagy bodies; this can confirm their hypothyroidism. Possibly, the known leptin mutation along with other unknown paracrine secretions alter both T and C thyrocytes' functions of the fa/fa rats, allowing high intracellular calcium and lower pH favoring autophagocytosis. Other longitudinal, interdisciplinary studies should further clarify the complex paracrine interactions existing between these endocrine structures because this animal model could be useful to understand human defects, such as the metabolic syndrome that involves obesity, cardiovascular, renal, hepatic, non-insulin dependent diabetes mellitus (NIDDM), hypothyroidism defects, as well as the etiology of thyroid medullary tumors.

Pro-oxidant treatment of human prostate carcinoma (DU145) induces autoschizis cell death: autophagosomes build up out of injured endomembranes and mitochondria.

One hour after pro-oxidative treatment by either ascorbate (VC), menadione (VK3), or VC: VK3 combination followed by 24-h incubation in culture medium, DU145 human prostate carcinoma cells developed ultrastructural-dependent organelle damage with the sequence Sham > VC > VK3 > VC: VK3. Along the nuclear alterations and the cytoplasm self-excisions reducing cell size, other induced injuries concerned mitochondria and endomembranes that associated with lysosomes. Damaged organelles surrounded by specialized endoplasmic membranes formed autophagosomes out of phagophores that also captured pieces of glycogen-rich cytoplasm. Most autophagosomes amassed in the diminished-size perikarya and corroborated the enhanced cytotoxicity of the VC: VK3 treatment. These accumulations did not initiate cell death, instead were merely signs of excessive "recycling" of damaged organelles. These features may reflect that high lysosomal activities provided foodstuffs in an ultimate strategy of survival of the tumor cells already devastated by reactive oxidative species (ROS) energetic sites. As such they became transient markers preceding cell death induced to occur by autoschizis and not by apoptosis or other cell deaths. This report could provide more support for the usage of this vitamin combination named APATONE as inexpensive potent adjuvant or treatment in prostate cancers.

Synergistic antitumor cytotoxic actions of ascorbate and menadione on human prostate (DU145) cancer cells in vitro: nucleus and other injuries preceding cell death by autoschizis.

Scanning (SEM) and transmission electron microscopy (TEM) were used to characterize the cytotoxic effects of ascorbate (VC), menadione (VK3), or a VC:VK3 combination on a human prostate carcinoma cell line (DU145) following a 1-h vitamin treatment and a subsequent 24-h incubation in culture medium. Cell alterations examined by light and electron microscopy were treatment-dependent with VC + VK3 >VK3 > VC > Sham. Oxidative stress-induced damage was found in most organelles. This report describes injuries in the tumor cell nucleus (chromatin and nucleolus), mitochondria, endomembranes, lysosomal bodies (autophagocytoses) and inclusions. Morphologic alterations suggest that cytoskeleton damage is likely responsible for the superficial cytoplasmic changes, including major changes in cell shape and size and the self-excising phenomena. Unlike apoptotic bodies, the excised pieces contain ribonucleoproteins, but not organelles. These deleterious events cause a progressive, significant reduction in the tumor cell size. During nuclear alterations, the nuclei maintain their envelope during chromatolysis and karyolysis until cell death, while nucleoli undergo a characteristic segregation of their components. In addition, changes in fat and glycogen storage are consistent the cytotoxic and metabolic alterations caused by the respective treatments. All cellular ultrastructural changes are consistent with cell death by autoschizis and not apoptosis or other kinds of cell death.

A rare, human prostate oncocyte cell originates from the prostatic carcinoma (DU145) cell line.

DU145 human prostate carcinoma cells are typically poorly differentiated and contain only scantily distributed organelles. However, among numerous tumor cells randomly examined by electron microscopy out of in vitro cultivation, a peculiar, rare oncocyte-like cell type has been observed whose nucleus appears to be of small dimension and with a cytoplasm almost entirely filled with often distorted mitochondria. A few small, dispersed lysosomal bodies, small cisterns of the endoplasmic reticulum and a few glycogen patches can be found among highly osmiophilic contrasted, cytosolic spaces filled by innumerable ribonucleoproteins. The excessive population of mitochondria may have arisen from a more populated tumor cell type wherein the altered mitochondria are found to appear burgeoning into a spherical-like size progeny crowding the tumor cells. Literature cited between 1950 and the present suggests that this rare, oncocytic, benign prostatic tumor cell type is likely appear epigenetically, stemming from an original secretory cell, which is confirmed by the origin of the cell line originally maintained as cell line out of a brain metastatic, adenocarcinoma niche.

Viral Entry Inhibitors Protect against SARS-CoV-2-Induced Neurite Shortening in Differentiated SH-SY5Y Cells.

The utility of human neuroblastoma cell lines as in vitro model to study neuro-invasiveness and neuro-virulence of SARS-CoV-2 has been demonstrated by our laboratory and others. The aim of this report is to further characterize the associated cellular responses caused by a pre-alpha SARS-CoV-2 strain on differentiated SH-SY5Y and to prevent its cytopathic effect by using a set of entry inhibitors. The susceptibility of SH-SY5Y to SARS-CoV-2 was confirmed at high multiplicity-of-infection, without viral replication or release. Infection caused a reduction in the length of neuritic processes, occurrence of plasma membrane blebs, cell clustering, and changes in lipid droplets electron density. No changes in the expression of cytoskeletal proteins, such as tubulins or tau, could explain neurite shortening. To counteract the toxic effect on neurites, entry inhibitors targeting TMPRSS2, ACE2, NRP1 receptors, and Spike RBD were co-incubated with the viral inoculum. The neurite shortening could be prevented by the highest concentration of camostat mesylate, anti-RBD antibody, and NRP1 inhibitor, but not by soluble ACE2. According to the degree of entry inhibition, the average amount of intracellular viral RNA was negatively correlated to neurite length. This study demonstrated that targeting specific SARS-CoV-2 host receptors could reverse its neurocytopathic effect on SH-SY5Y.

Lesion Extension and Neuronal Loss after Spinal Cord Injury Using X-Ray Phase-Contrast Tomography in Mice.

Following spinal cord injury (SCI) the degree of functional (motor, autonomous, or sensory) loss correlates with the severity of nervous tissue damage. An imaging technique able to capture non-invasively and simultaneously the complex mechanisms of neuronal loss, vascular damage, and peri-lesional tissue reorganization is currently lacking in experimental SCI studies. Synchrotron X-ray phase-contrast tomography (SXPCT) has emerged as a non-destructive three-dimensional (3D) neuroimaging technique with high contrast and spatial resolution. In this framework, we developed a multi-modal approach combining SXPCT, histology and correlative methods to study neurovascular architecture in normal and spinal level C4-contused mouse spinal cords (C57BL/6J mice, age 2-3 months). The evolution of SCI lesion was imaged at the cell resolution level during the acute (30 min) and subacute (7 day) phases. Spared motor neurons (MNs) were segmented and quantified in different volumes localized at and away from the epicenter. SXPCT was able to capture neuronal loss and blood-brain barrier breakdown following SCI. Three-dimensional quantification based on SXPCT acquisitions showed no additional MN loss between 30 min and 7 days post-SCI. In addition, the analysis of hemorrhagic (at 30 min) and lesion (at 7 days) volumes revealed a high similarity in size, suggesting no extension of tissue degeneration between early and later time-points. Moreover, glial scar borders were unevenly distributed, with rostral edges being the most extended. In conclusion, SXPCT capability to image at high resolution cellular changes in 3D enables the understanding of the relationship between hemorrhagic events and nervous structure damage in SCI.

Xenotransplanted human prostate carcinoma (DU145) cells develop into carcinomas and cribriform carcinomas: ultrastructural aspects.

Androgen-independent, human prostate carcinoma cells (DU145) develop into solid, carcinomatous xenotransplants on the diaphragm of nu/nu mice. Tumors encompass at least two poorly differentiated cell types: a rapidly dividing, eosinophilic cell comprises the main cell population and a few, but large basophilic cells able to invade the peritoneal stroma, the muscular tissue, lymph vessels. Poor cell contacts, intracytoplasmic lumina, and signet cells are noted. Lysosomal activities are reflected by entoses and programmed cell deaths forming cribriform carcinomas. In large tumors, degraded cells may align with others to facilitate formation of blood supply routes. Malignant cells would spread via ascites and through lymphatics.

Blood-brain barrier permeability towards small and large tracers in a mouse model of osmotic demyelination syndrome.

During osmotic demyelination syndrome (ODS), myelin and oligodendrocyte are lost according to specific patterns in centro- or extra-pontine regions. In both experimental model of ODS and human cases, brain lesions are locally correlated with the disruption of the blood brain-barrier (BBB). The initiation, the degree and the duration of blood-brain barrier (BBB) opening as well as its contribution to brain damages are still a matter of debate. Using a panel of intravascular tracers from low- to high- molecular weight (from 0.45 kDa 150 kDa), we have assessed the BBB permeability at different timings of ODS induced experimentally in mice. ODS was mimicked according to a protocol of rapid correction of a chronic hyponatremia. We demonstrated that BBB leakage towards smallest tracers Lucifer Yellow (0.45 kDa) and Texas Red-dextran (3 kDa) was delayed by 36 h compared to the first clues of oligodendrocyte loss (occurring 12 h post-correction of hyponatremia). At 48 h post-correction and concomitantly to myelin loss, BBB was massively disrupted as attested by accumulation of Evans Blue (69 kDa) and IgG (150 kDa) in brain parenchyma. Analysis of BBB ultrastructure verified that brain endothelial cells had minimal alterations during chronic hyponatremia and at 12 h post-correction of hyponatremia. However, brain endothelium yielded worsened alterations at 48 h, such as enlarged vesicular to tubular-like cytoplasmic profiles of pinocytosis and/or transcytosis, local basal laminae abnormalities and sub-endothelial cavities. The protein expressions of occludin and claudin-1, involved in inter-endothelial tight junctions, were also downregulated at 48 h post-correction of hyponatremia. Our results revealed that functional BBB opening occured late in pre-established ODS lesions, and therefore was not a primary event initiating oligodendrocyte damages in the mouse model of ODS.

Cystine-glutamate antiporter deletion accelerates motor recovery and improves histological outcomes following spinal cord injury in mice.

xCT is the specific subunit of System xc-, an antiporter importing cystine while releasing glutamate. Although xCT expression has been found in the spinal cord, its expression and role after spinal cord injury (SCI) remain unknown. The aim of this study was to characterize the role of xCT on functional and histological outcomes following SCI induced in wild-type (xCT+/+) and in xCT-deficient mice (xCT-/-). In the normal mouse spinal cord, slc7a11/xCT mRNA was detected in meningeal fibroblasts, vascular mural cells, astrocytes, motor neurons and to a lesser extent in microglia. slc7a11/xCT gene and protein were upregulated within two weeks post-SCI. xCT-/- mice recovered muscular grip strength as well as pre-SCI weight faster than xCT+/+ mice. Histology of xCT-/- spinal cords revealed significantly more spared motor neurons and a higher number of quiescent microglia. In xCT-/- mice, inflammatory polarization shifted towards higher mRNA expression of ym1 and igf1 (anti-inflammatory) while lower levels of nox2 and tnf-a (pro-inflammatory). Although astrocyte polarization did not differ, we quantified an increased expression of lcn2 mRNA. Our results show that slc7a11/xCT is overexpressed early following SCI and is detrimental to motor neuron survival. xCT deletion modulates intraspinal glial activation by shifting towards an anti-inflammatory profile.