Current Neurovascular Research - Volume 9, Issue 4, 2012

The objective of this investigation was to assess the toxicological potential of nasal formulation of erythropoietin with low sialic acid content (Neuro EPO) after 28 days of intra-nasal dosing in rats besides to evaluate the immunogenicity and erythropoietic effect of the test substance. Healthy Wistar rats of both sexes were used for 28 days subacute toxicity and immunogenicity assays. Doses evaluated were 3450, 4830 and 6900 UI/kg/day. The toxicological endpoints examined included animal body weight, food consumption, hematological and biochemical patterns, antibodies determination, selected tissue weights and histopathological examination. Reversibility of toxic effects was evaluated at high dose 14 days after treatment period. Female B6D2F1 mice were used for evaluated erythropoietic effect of the nasal formulation. Hematological endpoints were examined every week during 28 days of intra-nasal dosing of 6900 UI/kg/day. Variations of hematological patterns were not observed after 28 days of intranasal dosing. A slight increase in glucose level of treated animals within the normal range was observed. This effect was not dose related and was reversible. Antibody formation was not observed in any of the test doses. Histopathological examination of organs and tissues did not reveal treatment induced changes. The administration of Neuro EPO in normocythaemic mice did not produce erythropoietic effect. These results suggest that Neuro EPO could be used as a neuroprotective agent, without significant systemic haematological side effects.

Given the present challenges to attain effective treatment for β-amyloid (Aβ) toxicity in neurodegenerative disorders such as Alzheimer's disease, development of novel cytoprotective pathways that can assist immune mediated therapies through the preservation of central nervous system microglia could offer significant promise. We show that the CCN4 protein, Wnt1 inducible signaling pathway protein 1 (WISP1), is initially up-regulated by Aβ and can modulate its endogenous expression for the protection of microglia during Aβ mediated apoptosis. WISP1 activates mTOR and phosphorylates p70S6K and 4EBP1 through the control of the regulatory mTOR component PRAS40. Loss of PRAS40 through gene reduction or inhibition by WISP1 is cytoprotective. WISP1 ultimately governs PRAS40 by sequestering PRAS40 intracellularly through post-translational phosphorylation and binding to protein 14-3-3. Our work identifies WISP1, mTOR signaling, and PRAS40 as targets for new strategies directed against Alzheimer's disease and related disorders.

Stem cell transplantation is a promising therapy for neuromyelitis optica (NMO). Among stem cell varieties, human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) possess many advantages, add a differential potential into neural cells, secrete a set of trophic factors and cytokines, regulate immunological function, and have therapeutic potential for neurological diseases. In this study, hUC-MSCs transplantation was used to treat five NMO patients with follow-up for 18 months including evaluation of Expanded Disability Status Scale (EDSS) levels, clinical course, magnetic resonance imaging (MRI) characteristics, adverse events, and so on. Among the five cases, four showed therapeutic improvement after hUC-MSCs treatment. Both symptoms and signs improved and relapse frequencies were reduced. MRI characteristics also showed decreased volume and severity of lesions, while few adverse events occurred. The results suggest that hUC-MSCs transplantation appear safe and might be effective for NMO treatment in the near future. In addition, according to flow cytometry assay (FACS) results, B cells of blood were inhibited while T cells increased after treatment, indicating an immune-related mechanism.

Age-related macular degeneration (AMD) is a leading cause of blindness and is the third leading cause of blindness. Genetic factors are known to influence an individual's risk for developing AMD. Linkage has earlier been shown to the vascular endothelial growth factor 2 (VEGF2) gene and AMD. To examine the role of VEGFR2 in north Indian population, we conducted a case control study. Total 176 subjects were enrolled in a case-control genetic study. Real-Time PCR was used to analyze the SNPs (rs1531289 and rs2305948) of VEGFR-2 gene. ELISA was conducted to determine the levels of VEGFR2. A non-parametric Mann-Whitney-U test was applied for comparison of the ELISA levels and pearson's Chi-square test was applied to study the association of polymorphism between various groups. The single SNP (rs1531289) AG genotype was significantly associated with AMD (OR= 2.13, 95%CI= 1.011-4.489, P=0.047). VEGFR2 levels were found to be increased significantly in AMD patients as compared to normal controls. We also found significant increase in the levels of wet AMD as compared to dry AMD. This study demonstrates higher levels of VEGFR2 and frequency of AG (rs1531289) genotype in AMD patient population, suggesting the role of VEGFR-2 in pathogenesis of AMD.

We investigated in post-acute ischemic stroke patients the influence of intensive neurorehabilitation on oxidative stress balance during recovery of neurological deficits. For this purpose, fourteen patients were included in the study within 30 days of stroke onset. Outcome measures were the National Institutes of Health Stroke Scale (NIHSS), the modified Rankin Scale (mRS), the Barthel Index, and the Katz Index. Redox balance was assessed by measuring plasma peroxidative by-products, nitrite/nitrate metabolites (NOx), as an index of nitric oxide (NO), Cu/Zn Superoxide Dismutase (Cu/Zn SOD) activity, serum urate concentration, autoantibodies against ox-LDL (OLAB) serum level and plasma antioxidant capacity. Assessments were made before and after neurorehabilitation. Fifteen apparently healthy controls were investigated to compare redox markers. Intensive neurorehabilitation was associated with an improvement of all the outcome measures (P<0.05). Decreased values of peroxidative by-products and of NOx (P<0.05) were observed after neurorehabilitation in stroke patients even though their values were higher than in controls (P<0.05). Changes observed before and after neurorehabilitation in NIHSS scores (Δ NIHSS scores) and in plasma NOx amount (Δ NOx) correlated positively (r=0.79; P <0.005). No differences in EC-SOD activity, OLAB and serum urate concentrations were found between stroke patients and controls, before and after neurorehabilitation. Total plasma antioxidant capacity, lower in stroke patients than in controls before neurorehabilitation, was unchanged thereafter. Our data provide evidence of the effectiveness of neurorehabilitation on reducing redox unbalance in stroke patients and hints the role of NO as a messenger involved in post-ischemic neuronal plasticity influencing recovery of neurological deficits.

Trauma introduces damaging stressors that compromise protein, lipid, and nucleic acid integrity. Aggregates of unfolded and misfolded proteins in the endoplasmic reticulum (ER) triggers the ER stress response (ERSR)/unfolded protein response (UPR) leading to activation of three signaling pathways mediated by PERK, ATF6, and IRE1. Initially, the ERSR/UPR is pro-homeostatic as it globally slows translation while increasing translation of chaperone proteins and inducing ER-associated degradation. If the cellular stress is not controlled, apoptosis is subsequently induced through several mechanisms, of which the most well-described is CHOP. Following spinal cord injury (SCI), mice deficient in CHOP signaling show increased spared white matter and enhanced locomotor recovery by 6 weeks. At 24 hours after SCI, ATF4 and CHOP are upregulated in under perfused microvessels. We observed vascular protection 3 days post-SCI and a significant decrease in macrophage infiltration by the end of the first week. These results suggest that modulating ER-stress signaling in endothelial cells and macrophages may protect against vascular injury and attenuate inflammation post-SCI.

Doxorubicin (DOX), a prominent anticancer agent has enjoyed considerable popularity in the last few decades because of its usefulness in the management of various forms of cancers, but its organotoxic potential (cardio-, hepatoand nephrotoxicity) has constrained on its clinical use. This study investigated whether DOX has the ability to cause nephrotoxicity in vivo and if so, whether it is linked to oxidative stress (OS). Another important goal was to describe whether expression of pro- and anti-apoptotic genes in kidneys was driven by OS. In order to explore DOX's nephrotoxic potential, male rats (Sprague Dawley; 500–520g; fed ad libitum) were administered i.p. with a single dose of DOX (12 mg/kg) on day one and sacrificed seven days later (day 8). Changes in serum chemistries (i.e., serum urea nitrogen, SUN, and creatinine) were determined immediately upon sacrifice, whereas kidney tissues were subjected to several sensitive biomarkers for OS, such as, lipid peroxidation, Superoxide dismutase (SOD) activity and chromatin fragmentation. The most important goal was to evaluate the select expression of Apaf-1, Caspase-3, Bad, Bax, Bcl-2, Bcl-xL, p53 and Mdm2 genes in order to understand the underlying link between extrinsic and intrinsic pathways of cell death. Data revealed that DOX-exposed animals showed significant nephrotoxicity as reflected in increased SUN (5.6-fold) and creatinine (2.65 fold) levels with considerably decreased body weight. Increases in kidney injury markers reflected parallel elevations in lipid peroxidation (1.7-fold) and genomic DNA fragmentation (2.9 fold) coupled with a proportionate reduction in total SOD activity suggesting DOX-assaulted kidneys encountered massive OS. Western blot showed very striking changes: i) substantial increases in the expression of pro-apoptotic APAF-1, Caspase-3, Bax and Bad proteins; ii) Reduction in the expression of anti-apoptotic Bcl-2 and Bcl-xL genes; iii) considerable increase in the expression of p53 and suppression of its regulator Mdm2. Serum chemistry and tissue biochemistry mirrored histopathology. In conclusion, this study for the first time may have shown a close link between mitochondrial perturbations and cell death regulating genes during DOXinduced nephrotoxicity, and described DOX's potential to inflict kidney injury in addition to other organs during chemotherapy in clinical setting.

The pathogenesis of cerebral small vessel disease (CSVD) in the elderly is poorly understood. Endothelial cell activation and dysfunction may play a causal role in the pathogenesis of CSVD. It was reported that anti-endothelial cell antibodies (AECAs) are associated with endothelial cell dysfunction and inflammation. We hypothesized that AECAs may be associated with the pathogenesis of CSVD. We examined AECAs in sera from 12 elderly subjects with CSVD, 12 elderly subjects without CSVD, and 18 healthy volunteers by 2-dimensional immunoblotting using primary cultured human brain microvascular endothelial cells as the antigen source. We identified 4 AECAs that were detected in sera from more than one-half of the elderly subjects with CSVD. Subsequently, we analyzed the target antigens of these 4 antibodies by liquid chromatography-tandem mass spectrometry. The target antigens of these 4 antibodies were tropomyosin alpha-4 chain (TPM4), vimentin, alpha-enolase, and annexin A2. Among these 4 antibodies, the anti-TPM4 antibody was significantly more frequently detected in sera from the elderly subjects with CSVD than the other subjects. We determined the anti-TPM4 antibody level in sera from 21 elderly subjects with CSVD and 25 subjects without CSVD by enzyme-linked immunosorbent assay. The anti-TPM4 antibody level was significantly higher in the subjects with than without CSVD. Therefore, an autoimmune, inflammatory process with high levels of anti-TPM4 antibody may contribute to the development of CSVD in the elderly.

The establishment of a link between VEGF, hypoxia and ALS pathogenesis placed angiogenic factors and oxidative stress at the focal point for further studies. Recreation of a phenotype strikingly similar to that of mutant SOD1 mouse and human ALS, like muscle weakness and atrophy owing to lower motor neuron degeneration was observed following the targeted deletion of the hypoxia response element (HRE) from promoter of mouse vascular endothelial growth factor (VEGF). The crucial link between vasculature, angiogenic molecules and motor neuron degeneration has thus been constantly scrutinized. In this review, we have proposed to correlate human, in vitro and cadaveric studies so as to find out whether molecules like VEGF and various others, at the interface of neurovascular network and oxidative stress, have a prognostic, diagnostic and therapeutic potential for treatment of a fatal neurodegenerative disorder namely ALS.

Non-traumatic subarachnoid hemorrhage (SAH) represents about 5 to 6% of the overall incidence of stroke and is associated with high morbidity and mortality. Despite the substantial research and clinical efforts, delayed cerebral ischemia (DCI) is still the major complication after SAH and represents an important factor for severe neurological deficits. Cerebral vasospasm (VSP) has been recognised for a long time as an important underlying pathophysiologic cause of DCI, but it is now clearer that the mechanisms underlying DCI are multifactorial. Among other pathomechanisms proposed, ischemia-producing cortical spreading depolarizations (CSDs) are likely to be involved in DCI development. Understanding the plethora of different pathophysiological derangements after SAH is very important for the development of new therapies, in order to abolish secondary ischemic brain injuries early-on and improve patients' outcome. In this review, we strive to summarise the mechanisms and therapeutic developments of DCI.