Spinal cord injury induced heat shock protein expression is reduced by an antioxidant compound H-290/51. An experimental study using light and electron microscopy in the rat

Nanodelivery of histamine H3 receptor inverse agonist BF-2649 with H3 receptor antagonist and H4 receptor agonist clobenpropit induced neuroprotection is potentiated by antioxidant compound H-290/51 in spinal cord injury

Military personnel are often victims of spinal cord injury resulting in lifetime disability and decrease in quality of life. However, no suitable therapeutic measures are still available to restore functional disability or arresting the pathophysiological progression of disease in victims for leading a better quality of life. Thus, further research in spinal cord injury using novel strategies or combination of available neuroprotective drugs is urgently needed for superior neuroprotection. In this regard, our laboratory is engaged in developing TiO2 nanowired delivery of drugs, antibodies and enzymes in combination to attenuate spinal cord injury induced pathophysiology and functional disability in experimental rodent model. Previous observations show that histamine antagonists or antioxidant compounds when given alone in spinal cord injury are able to induce neuroprotection for short periods after trauma. In this investigation we used a combination of histaminergic drugs with antioxidant compound H-290/51 using their nanowired delivery for neuroprotection in spinal cord injury of longer duration. Our observations show that a combination of H3 receptor inverse agonist BF-2549 with H3 receptor antagonist and H4 receptor agonist clobenpropit induced neuroprotection is potentiated by antioxidant compound H-290/51 in spinal cord injury. These observations suggests that histamine receptors are involved in the pathophysiology of spinal cord injury and induce superior neuroprotection in combination with an inhibitor of lipid peroxidation H-290/51, not reported earlier. The possible mechanisms and significance of our findings in relation to future clinical approaches in spinal cord injury is discussed.

Spinal cord injury induced exacerbation of Alzheimer's disease like pathophysiology is reduced by topical application of nanowired cerebrolysin with monoclonal antibodies to amyloid beta peptide, p-tau and tumor necrosis factor alpha

Hallmark of Alzheimer's disease include amyloid beta peptide and phosphorylated tau deposition in brain that could be aggravated following traumatic of concussive head injury. However, amyloid beta peptide or p-tau in spinal cord following injury is not well known. In this investigation we measured amyloid beta peptide and p-tau together with tumor necrosis factor-alpha (TNF-α) in spinal cord and brain following 48 h after spinal cord injury in relation to the blood-spinal cord and blood-brain barrier, edema formation, blood flow changes and cell injury in perifocal regions of the spinal cord and brain areas. A focal spinal cord injury was inflicted over the right dorsal horn of the T10-11 segment (4 mm long and 2 mm deep) and amyloid beta peptide and p-tau was measured in perifocal rostral (T9) and caudal (T12) spinal cord segments as well as in the brain areas. Our observations showed a significant increase in amyloid beta peptide in the T9 and T12 segments as well as in remote areas of brain and spinal cord after 24 and 48 h injury. This is associated with breakdown of the blood-spinal cord (BSCB) and brain barriers (BBB), edema formation, reduction in blood flow and cell injury. After 48 h of spinal cord injury elevation of amyloid beta peptide, phosphorylated tau (p-tau) and tumor necrosis factor-alpha (TNF-α) was seen in T9 and T12 segments of spinal cord in cerebral cortex, hippocampus and brain stem regions associated with microglial activation as seen by upregulation of Iba1 and CD86. Repeated nanowired delivery of cerebrolysin topically over the traumatized segment repeatedly together with monoclonal antibodies (mAb) to amyloid beta peptide (AβP), p-tau and TNF-α significantly attenuated amyloid beta peptide, p-tau deposition and reduces Iba1, CD68 and TNF-α levels in the brain and spinal cord along with blockade of BBB and BSCB, reduction in blood flow, edema formation and cell injury. These observations are the first to show that spinal cord injury induces Alzheimer's disease like symptoms in the CNS, not reported earlier.

Co-Administration of Nanowired Monoclonal Antibodies to Inducible Nitric Oxide Synthase and Tumor Necrosis Factor Alpha Together with Antioxidant H-290/51 Reduces SiO2 Nanoparticles-Induced Exacerbation of Pathophysiology of Spinal Cord Trauma

Military personnel are often exposed to silica dust during combat operations across the globe. Exposure to silica dust in US military or service personnel could cause Desert Strom Pneumonitis also referred to as Al Eskan disease causing several organs damage and precipitate autoimmune dysfunction. However, the effects of microfine particles of sand inhalation-induced brain damage on the pathophysiology of traumatic brain or spinal cord injury are not explored. Previously intoxication of silica nanoparticles (50-60 nm size) is shown to exacerbates spinal cord injury induces blood-spinal cord barrier breakdown, edema formation and cellular changes. However, the mechanism of silica nanoparticles-induced cord pathology is still not well known. Spinal cord injury is well known to alter serotonin (5-hydroxytryptamine) metabolism and induce oxidative stress including upregulation of nitric oxide synthase and tumor necrosis factor alpha. This suggests that these agents are involved in the pathophysiology of spinal cord injury. In this review, we examined the effects of combined nanowired delivery of monoclonal antibodies to neuronal nitric oxide synthase (nNOS) together with tumor necrosis factor alpha (TNF-α) antibodies and a potent antioxidant H-290/51 to induce neuroprotection in spinal cord injury associated with silica nanoparticles intoxication. Our results for the first time show that co-administration of nanowired delivery of antibodies to nNOS and TNF-α with H-290/51 significantly attenuated silica nanoparticles-induced exacerbation of spinal cord pathology, not reported earlier.

Methamphetamine exacerbates pathophysiology of traumatic brain injury at high altitude. Neuroprotective effects of nanodelivery of a potent antioxidant compound H-290/51

Military personnel are often exposed to high altitude (HA, ca. 4500-5000m) for combat operations associated with neurological dysfunctions. HA is a severe stressful situation and people frequently use methamphetamine (METH) or other psychostimulants to cope stress. Since military personnel are prone to different kinds of traumatic brain injury (TBI), in this review we discuss possible effects of METH on concussive head injury (CHI) at HA based on our own observations. METH exposure at HA exacerbates pathophysiology of CHI as compared to normobaric laboratory environment comparable to sea level. Increased blood-brain barrier (BBB) breakdown, edema formation and reductions in the cerebral blood flow (CBF) following CHI were exacerbated by METH intoxication at HA. Damage to cerebral microvasculature and expression of beta catenin was also exacerbated following CHI in METH treated group at HA. TiO2-nanowired delivery of H-290/51 (150mg/kg, i.p.), a potent chain-breaking antioxidant significantly enhanced CBF and reduced BBB breakdown, edema formation, beta catenin expression and brain pathology in METH exposed rats after CHI at HA. These observations are the first to point out that METH exposure in CHI exacerbated brain pathology at HA and this appears to be related with greater production of oxidative stress induced brain pathology, not reported earlier.

Neuroprotective effects of insulin like growth factor-1 on engineered metal nanoparticles Ag, Cu and Al induced blood-brain barrier breakdown, edema formation, oxidative stress, upregulation of neuronal nitric oxide synthase and brain pathology

Military personnel are vulnerable to environmental or industrial exposure of engineered nanoparticles (NPs) from metals. Long-term exposure of NPs from various sources affect sensory-motor or cognitive brain functions. Thus, a possibility exists that chronic exposure of NPs affect blood-brain barrier (BBB) breakdown and brain pathology by inducing oxidative stress and/or nitric oxide production. This hypothesis was examined in the rat intoxicated with Ag, Cu or Al (50-60nm) nanoparticles (50mg/kg, i.p. once daily) for 7 days. In these NPs treated rats the BBB permeability, brain edema, neuronal nitric oxide synthase (nNOS) immunoreactivity and brain oxidants levels, e.g., myeloperoxidase (MP), malondialdehyde (MD) and glutathione (GT) was examined on the 8th day. Cu and Ag but not Al nanoparticles increased the MP and MD levels by twofold in the brain although, GT showed 50% decline. At this time increase in brain water content and BBB breakdown to protein tracers were seen in areas exhibiting nNOS positive neurons and cell injuries. Pretreatment with insulin like growth factor-1 (IGF-1) in high doses (1μg/kg, i.v. but not 0.5μg/kg daily for 7 days) together with NPs significantly reduced the oxidative stress, nNOS upregulation, BBB breakdown, edema formation and cell injuries. These novel observations demonstrate that (i) NPs depending on their metal constituent (Cu, Ag but not Al) induce oxidative stress and nNOS expression leading to BBB disruption, brain edema and cell damage, and (ii) IGF-1 depending on doses exerts powerful neuroprotection against nanoneurotoxicity, not reported earlier.

Targeting apoptosis and autophagy following spinal cord injury: Therapeutic approaches to polyphenols and candidate phytochemicals

Spinal cord injury (SCI) is a neurological disorder associated with the loss of sensory and motor function. Understanding the precise dysregulated signaling pathways, especially apoptosis and autophagy following SCI, is of vital importance in developing innovative therapeutic targets and treatments. The present study lies in the fact that it reveals the precise dysregulated signaling mediators of apoptotic and autophagic pathways following SCI and also examines the effects of polyphenols and other candidate phytochemicals. It provides new insights to develop new treatments for post-SCI complications. Accordingly, a comprehensive review was conducted using electronic databases including, Scopus, Web of Science, PubMed, and Medline, along with the authors' expertise in apoptosis and autophagy as well as their knowledge about the effects of polyphenols and other phytochemicals on SCI pathogenesis. The primary mechanical injury to spinal cord is followed by a secondary cascade of apoptosis and autophagy that play critical roles during SCI. In terms of pharmacological mechanisms, caspases, Bax/Bcl-2, TNF-α, and JAK/STAT in apoptosis along with LC3 and Beclin-1 in autophagy have shown a close interconnection with the inflammatory pathways mainly glutamatergic, PI3K/Akt/mTOR, ERK/MAPK, and other cross-linked mediators. Besides, apoptotic pathways have been shown to regulate autophagy mediators and vice versa. Prevailing evidence has highlighted the importance of modulating these signaling mediators/pathways by polyphenols and other candidate phytochemicals post-SCI. The present review provides dysregulated signaling mediators and therapeutic targets of apoptotic and autophagic pathways following SCI, focusing on the modulatory effects of polyphenols and other potential phytochemical candidates.

Proteomic profiling of proteins in the dorsal horn of the spinal cord in dairy cows with chronic lameness

Chronic lameness affects bovine welfare and has a negative economic impact in dairy industry. Moreover, due to the translational gap between traditional pain models and new drugs development for treating chronic pain states, naturally occurring painful diseases could be a potential translational tool for chronic pain research. We therefore employed liquid chromatography tandem mass spectrometry (LC-MS/MS) to stablish the proteomic profile of the spinal cord samples from lumbar segments (L2-L4) of chronic lame dairy cows. Data were validated and quantified through software tool (Scaffold® v 4.0) using output data from two search engines (SEQUEST® and X-Tandem®). Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) analysis was performed to detect proteins interactions. LC-MS/MS identified a total amount of 177 proteins; of which 129 proteins were able to be quantified. Lame cows showed a strong upregulation of interacting proteins with chaperone and stress functions such as Hsp70 (p < 0.006), Hsc70 (p < 0.0079), Hsp90 (p < 0.015), STIP (p > 0.0018) and Grp78 (p <0.0068), and interacting proteins associated to glycolytic pathway such as; γ-enolase (p < 0.0095), α-enolase (p < 0.013) and hexokinase-1 (p < 0.028). It was not possible to establish a clear network of interaction in several upregulated proteins in lame cows. Non-interacting proteins were mainly associated to redox process and cytoskeletal organization. The most relevant down regulated protein in lame cows was myelin basic protein (MBP) (p < 0.02). Chronic inflammatory lameness in cows is associated to increased expression of stress proteins with chaperone, metabolism, redox and structural functions. A state of endoplasmic reticulum stress and unfolded protein response (UPR) might explain the changes in protein expression in lame cows; however, further studies need to be performed in order to confirm these findings.

Therapeutic potential of flavonoids in spinal cord injury

Spinal cord injury (SCI) is a catastrophic event that can profoundly affect a patient's life, with far-reaching social and economic effects. A consequential sequence of SCI is the significant neurological or psychological deficit, which obviously contributes to the overall burden of this condition. To date, there is no effective treatment for SCI. Therefore, developing novel therapeutic strategies for SCI is highly prioritized. Flavonoids, one of the most numerous and ubiquitous groups of plant metabolites, are the active ingredients of traditional Chinese medicine such as Scutellaria baicalensis Georgi (Huang Qin) or Ginkgo biloba (Ying Xin). Accumulated research data show that flavonoids possess a range of key pharmacological properties such as anti-inflammatory, anti-oxidant, anti-tumor, anti-viral, anti-cardiovascular disease, immunomodulatory, and neuroprotective effects. Based on this, the flavonoids show therapeutic potential for SCI diseases. In this paper, we will review the pharmacological properties of different types of flavonoids for the treatment of SCI diseases, and potential underlying biochemical mechanisms of action will also be described.

Chaperone Proteins in the Central Nervous System and Peripheral Nervous System after Nerve Injury

Injury to axons of the central nervous system (CNS) and the peripheral nervous system (PNS) is accompanied by the upregulation and downregulation of numerous molecules that are involved in mediating nerve repair, or in augmentation of the original damage. Promoting the functions of beneficial factors while reducing the properties of injurious agents determines whether regeneration and functional recovery ensues. A number of chaperone proteins display reduced or increased expression following CNS and PNS damage (crush, transection, contusion) where their roles have generally been found to be protective. For example, chaperones are involved in mediating survival of damaged neurons, promoting axon regeneration and remyelination and, improving behavioral outcomes. We review here the various chaperone proteins that are involved after nervous system axonal damage, the functions that they impact in the CNS and PNS, and the possible mechanisms by which they act.

Proof-of Concept that an Acute Trophic Factors Intervention After Spinal Cord Injury Provides an Adequate Niche for Neuroprotection, Recruitment of Nestin-Expressing Progenitors and Regeneration

Trophic factor treatment has been shown to improve the recovery of brain and spinal cord injury (SCI). In this study, we examined the effects of TSC1 (a combination of insulin-like growth factor 1 and transferrin) 4 and 8 h after SCI at the thoracic segment level (T12) in nestin-GFP transgenic mice. TSC1 treatment for 4 and 8 h increased the number of nestin-expressing cells around the lesion site and prevented Wallerian degeneration. Treatment with TSC1 for 4 h significantly increased heat shock protein (HSP)-32 and HSP-70 expression 1 and 2 mm from lesion site (both, caudal and rostral). Conversely, the number of HSP-32 positive cells decreased after an 8-h TSC1 treatment, although it was still higher than in both, non-treated SCI and intact spinal cord animals. Furthermore, TSC1 increased NG2 expressing cell numbers and preserved most axons intact, facilitating remyelination and repair. These results support our hypothesis that TSC1 is an effective treatment for cell and tissue neuroprotection after SCI. An early intervention is crucial to prevent secondary damage of the injured SC and, in particular, to prevent Wallerian degeneration.

Involvement of the choroid plexus in the inflammatory response after acute spinal cord injury in dogs: an immunohistochemical study

The choroid plexus (CP) is increasingly recognized as an important contributor to central nervous system (CNS) inflammation by recruitment of inflammatory cells and release of inflammatory cytokines. Here we investigate the role of the CP epithelium (CPE) as a source of three pro-inflammatory molecules of potential importance in inflammation after acute spinal cord injury (SCI): IL-1β, TNF-α, and hsp70. Immunohistochemical (IHC) staining for these three proteins was performed on 4th ventricular CPE from 4 dogs euthanized 12-48 h after spontaneous acute SCI, and from 4 neurologically normal dogs euthanized for other reasons. IHC staining was quantified using Aperio ImageScope software. IHC staining in the CPE of dogs with acute SCI was 2.2, 1.6 and 1.5 times higher than that of normal dogs, for IL-1β, TNF-α, and hsp70, respectively. Increases were statistically significant (p<0.1) for IL-1β and TNF-α, and closely approached significance for hsp70. These findings indicate that the CPE could serve as an important source of these inflammatory mediators after SCI. There was also an inverse correlation between IL-1β and hsp70 staining and duration of clinical signs in acute SCI, suggesting that increased expression of these proteins by the CPE may be of particular importance in the immediate-early inflammatory response after acute SCI.

Cerebrolysin Attenuates Heat Shock Protein (HSP 72 KD) Expression in the Rat Spinal Cord Following Morphine Dependence and Withdrawal: Possible New Therapy for Pain Management

The possibility that pain perception and processing in the CNS results in cellular stress and may influence heat shock protein (HSP) expression was examined in a rat model of morphine dependence and withdrawal. Since activation of pain pathways result in exhaustion of growth factors, we examined the influence of cerebrolysin, a mixture of potent growth factors (BDNF, GDNF, NGF, CNTF etc,) on morphine induced HSP expression. Rats were administered morphine (10 mg/kg, s.c. /day) for 12 days and the spontaneous withdrawal symptoms were developed by cessation of the drug administration on day 13^th that were prominent on day 14^th and continued up to day 15^th (24 to 72 h periods). In a separate group of rats, cerebrolysin was infused intravenously (5 ml/kg) once daily from day one until day 15^th. In these animals, morphine dependence and withdrawal along with HSP immunoreactivity was examined using standard protocol. In untreated group mild HSP immunoreaction was observed during morphine tolerance, whereas massive upregulation of HSP was seen in CNS during withdrawal phase that correlated well with the withdrawal symptoms and neuronal damage. Pretreatment with cerebrolysin did not affect morphine tolerance but reduced the HSP expression during this phase. Furthermore, cerebrolysin reduced the withdrawal symptoms on day 14^th to 15^th. Taken together these observations suggest that cellular stress plays an important role in morphine induced pain pathology and exogenous supplement of growth factors, i.e. cerebrolysin attenuates HSP expression in the CNS and induce neuroprotection. This indicates a new therapeutic role of cerebrolysin in the pathophysiology of drugs of abuse, not reported earlier.

Early microvascular reactions and blood-spinal cord barrier disruption are instrumental in pathophysiology of spinal cord injury and repair: novel therapeutic strategies including nanowired drug delivery to enhance neuroprotection

Spinal cord injury (SCI) is a devastating disease that leads to permanent disability of victims for which no suitable therapeutic intervention has been achieved so far. Thus, exploration of novel therapeutic agents and nano-drug delivery to enhance neuroprotection after SCI is the need of the hour. Previous research on SCI is largely focused to improve neurological manifestations of the disease while ignoring spinal cord pathological changes. Recent studies from our laboratory have shown that pathological recovery of SCI appears to be well correlated with the improvement of sensory motor functions. Thus, efforts should be made to reduce or minimize spinal cord cell pathology to achieve functional and cellular recovery to enhance the quality of lives of the victims. While treating spinal cord disease, recovery of both neuronal and non-neuronal cells, e.g., endothelia and glial cells are also necessary to maintain a healthy spinal cord function after trauma. This review focuses effects of novel therapeutic strategies on the role of spinal cord microvascular reactions and endothelia cell functions, i.e., blood-spinal cord barrier (BSCB) in SCI and repair mechanisms. Thus, new therapeutic approach to minimize spinal cord pathology after trauma using antibodies to various neurotransmitters and/or drug delivery to the cord directly by topical application to maintain strong localized effects on the injured cells are discussed. In addition, the use of nanowired drugs to affect remote areas of the cord after their application on the injured spinal cord in thwarting the injury process rapidly and to enhance the neuroprotective effects of the parent compounds are also described in the light of current knowledge and our own investigations. It appears that local treatment with new therapeutic agents and nanowired drugs after SCI are needed to enhance neurorepair leading to improved spinal cord cellular functions and the sensory motor performances.

The effect of hyperthermia on blood glutamate levels

INTRODUCTION

Glutamate neurotoxicity is determined by the balance between glutamate release within the brain and efflux of excess glutamate from the brain. Brain-to-blood efflux of glutamate is increased by decreasing the concentration of glutamate in blood. Little is known about the effect of hyperthermia on blood glutamate concentrations, and the effectiveness of blood glutamate-decreasing mechanisms in these conditions. Although hyperthermia is hypothesized to decrease blood glutamate concentrations by activation of stress mechanisms, blunting the stress response by blocking β-adrenergic receptors should prevent this decrease. Furthermore, during hyperthermia there should be a concurrent process of leakage of glutamate from muscle tissue into blood, resulting in a contradictory increase of blood glutamate concentrations. In this study we investigated the effects of hyperthermia on blood glutamate levels and studied the effects of the β-adrenergic receptor antagonist propranolol on stress-induced changes in glutamate levels. We then studied the effectiveness of the blood glutamate scavenger oxaloacetate on hyperthermia-induced increases of glutamate levels.

MATERIALS AND METHODS

Twenty-four rats were randomly divided into 3 groups. Rats' body temperatures were increased (by 1°C every 40 minutes) from 37°C to 42°C. The first group received 1 mL per 100 g of isotonic saline (control). The second group received 1 mL per 100 g of 1M oxaloacetate when the temperature reached 39°C. The third group received 10 mg/kg of propranolol before initiation of the warming.

RESULTS

Warming the rats from 37°C to 39°C decreased the blood glutamate levels in the control group (P < 0.01) and oxaloacetate treatment group (P < 0.0001), whereas further increases in temperature from 40°C to 42°C increased the blood glutamate levels (P < 0.01 and P < 0.0001, respectively). Pretreatment with propranolol prevented the decrease in blood glutamate concentrations seen in mild hyperthermia and did not affect the increase in blood glutamate levels seen at temperatures of 41°C and 42°C (P < 0.005).

DISCUSSION

The results of this study demonstrated that hyperthermia leads to decreases in glutamate levels in the blood, presumably by activation of the sympathetic nervous system. Oxaloacetate, previously reported to reduce blood glutamate levels at 37°C, was ineffective at temperatures over 40°C. Propranolol pretreatment blunted the initial decrease in blood glutamate, and thereafter had no effect when compared with control and treatment groups. Understanding the mechanisms underlying glutamate regulation in the blood during states of hyperthermia and stress has important clinical implications in treating neurodegenerative conditions.

Expression of heat shock protein (HSP 72 kDa) during acute methamphetamine intoxication depends on brain hyperthermia: neurotoxicity or neuroprotection?

In the present study, light and electron microscopy were used to examine heat shock protein (HSP 72 kD) expression during acute methamphetamine (METH) intoxication in rats and evaluate its relationships with brain temperature and alterations in a number of other histochemical and morphological parameters. Freely moving rats received METH at the same dose (9 mg/kg, sc) but at different ambient temperatures (23 and 29°C), showing a wide range of brain temperature elevations (37.6-42.5°C); brains were taken for histochemical and morphological evaluations at peak of brain temperature increase. We found that acute METH intoxication induces massive and wide-spread HSP expression in neural and glial cells examined in detail in the cortex, hippocampus, thalamus, and hypothalamus. In each of these structures, the number of HSP-positive cells tightly correlated with brain temperature elevation. The changes in HSP immunoreactivity were also tightly related to alterations in permeability of the blood-brain barrier, acute glial activation, and brain edema assessed by albumin and GFAP immunoreactivity and measuring tissue water content, respectively. While robust and generalized HSP production normally appears to be the part of an adaptive brain response associated with METH-induced metabolic activation, activation of this protective mechanism has its natural limits and could not counteract the damaging effects of oxidative stress, high temperature, and edema--the leading factors of METH-induced neurotoxicity.

Cerebrolysin reduces blood-cerebrospinal fluid barrier permeability change, brain pathology, and functional deficits following traumatic brain injury in the rat

Traumatic brain injuries (TBIs) induce profound breakdown of the blood-brain and blood-cerebrospinal fluid barriers (BCSFB), brain pathology/edema, and sensory-motor disturbances. Because neurotrophic factors, such as brain-derived neurotrophic factor (BDNF), insulin-like growth factor-1 (IGF-1), and glial cell-derived neurotrophic factor (GDNF), are neuroprotective in models of brain and spinal cord injuries, we hypothesized that a combination of neurotrophic factors would enhance neuroprotective efficacy. In the present investigation, we examined the effects of Cerebrolysin, a mixture of different neurotrophic factors (Ebewe Neuro Pharma, Austria) on the brain pathology and functional outcome in a rat model of TBI. TBI was produced under Equithesin (3 mL/kg, i.p.) anesthesia by making a longitudinal incision into the right parietal cerebral cortex. Untreated injured rats developed profound disruption of the blood-brain barrier (BBB) to proteins, edema/cell injury, and marked sensory-motor dysfunctions on rota-rod and grid-walking tests at 5 h TBI. Intracerebroventricular administration of Cerebrolysin (10 or 30 microL) either 5 min or 1 h after TBI significantly reduced leakage of Evans blue and radioiodine tracers across the BBB and BCSFB, and attenuated brain edema formation/neuronal damage in the cortex as well as underlying subcortical regions. Cerebrolysin-treated animals also had improved sensory-motor functions. However, administration of Cerebrolysin 2 h after TBI did not affect these parameters significantly. These observations in TBI demonstrate that early intervention with Cerebrolysin reduces BBB and BCSFB permeability changes, attenuates brain pathology and brain edema, and mitigates functional deficits. Taken together, our observations suggest that Cerebrolysin has potential therapeutic value in TBI.

Cerebrolysin treatment attenuates heat shock protein overexpression in the brain following heat stress: an experimental study using immunohistochemistry at light and electron microscopy in the rat

The possibility that overexpression of heat shock proteins (HSPs) in the CNS represents a neurodestructive signal following hyperthermia was examined in a rat model using a potent neuroprotective drug, Cerebrolysin (Ebewe Pharma, Austria). Rats subjected to four hours of heat stress in a biological oxygen demand incubator at 38 degrees C developed profound hyperthermia (41.23 +/- 0.14 degrees C) and overexpressed HSP 72 kD in several brain regions: cerebral cortex, hippocampus, cerebellum, thalamus, hypothalamus, brain stem, and spinal cord compared to controls. This HSP overexpression closely correlated with the leakage of blood-brain barrier permeability and vasogenic edema formation in these brain areas. HSP positive cells are largely confined in the edematous brain regions showing Evans blue leakage. Pretreatment with Cerebrolysin (5 mL/kg, i.v.) 30 minutes before heat stress markedly attenuated hyperthermia (39.48 +/- 0.23 degrees C, P < 0.01) and the induction of HSP to all the brain regions examined. Leakage of Evans blue albumin and increase in brain water content in these brain areas are also markedly reduced with Cerebrolysin pretreatment. These results are the first to show that Cerebrolysin, if administered before heat stress, attenuates hyperthermia induced stress reaction and HSP 72 kD induction. Taken together, these novel observations suggest that upregulation of HSP 72 kD in brain represents neurodestructive signals and a reduction in cellular stress mechanisms leading to decline in HSP expression is neuroprotective in nature.

Loss of hsp70.1 Decreases Functional Motor Recovery after Spinal Cord Injury in Mice

Heat shock proteins (HSPs) are specifically induced by various forms of stress. Hsp70.1, a member of the hsp70 family is known to play an important role in cytoprotection from stressful insults. However, the functional role of Hsp70 in motor function after spinal cord injury (SCI) is still unclear. To study the role of hsp70.1 in motor recovery following SCI, we assessed locomotor function in hsp70.1 knockout (KO) mice and their wild-type (WT) mice via the Basso, Beattie and Bresnahan (BBB) locomotor rating scale, before and after spinal hemisection at T13 level. We also examined lesion size in the spinal cord using Luxol fast blue/cresyl violet staining. One day after injury, KO and WT mice showed no significant difference in the motor function due to complete paralysis following spinal hemisection. However, when it compared to WT mice, KO mice had significantly delayed and decreased functional outcomes from 4 days up to 21 days after SCI. KO mice also showed significantly greater lesion size in the spinal cord than WT mice showed at 21 days after spinal hemisection. These results suggest that Hsp70 has a protective effect against traumatic SCI and the manipulation of the hsp70.1 gene may help improve the recovery of motor function, thereby enhancing neuroprotection after SCI.

PEGylated interferon-beta modulates the acute inflammatory response and recovery when combined with forced exercise following cervical spinal contusion injury

Secondary degeneration leads to an expansion of the initial tissue damage sustained during a spinal cord injury (SCI). Dampening the cellular inflammatory response that contributes to this progressive tissue damage is one possible strategy for neuroprotection after acute SCI. We initially examined whether treatment with a PEGylated form of rat interferon-beta (IFN-beta) would modulate the expression of several markers of inflammation and neuroprotection at the site of a unilateral cervical level 5 contusion injury. Adult female Sprague-Dawley rats were injured using the Infinite Horizon Impactor at a force of 200 kdyn (equivalent to a severe injury) and a mean displacement of 1600-1800 mum. A single dose (5x10(6) units) of PEGylated IFN-beta or vehicle was administered 30 min following SCI. Here we demonstrate temporal changes in pro- and anti-inflammatory cytokine levels and the expression of heat shock proteins and iNOS (involved in neuroprotection) at the lesion epicenter and one segment caudally after SCI and PEG IFN-beta treatment. The results suggested a potential therapeutic treatment strategy for modulation of secondary damage after acute SCI. Therefore, we examined whether acute treatment with PEG IFN-beta would improve forelimb function alone or when combined with forced exercise (Ex). Animals began the Ex paradigm 5 days post SCI and continued for 5 days/week over 8 weeks. Locomotion (forelimb locomotor scale [FLS], hindlimb BBB, and TreadScan) and sensorimotor function (grid walking) was tested weekly. Additional outcome measures included lesion size and glial cell reactivity. Significant FLS improvements occurred at 1 week post SCI in the PEGylated IFN-beta-treated group but not at any other time point or with any other treatment approaches. These results suggest that this acute neuroprotective treatment strategy does not translate into long term behavioral recovery even when combined with forced exercise.

Chapter 9 - Nanoparticles influence pathophysiology of spinal cord injury and repair

Spinal cord injury (SCI) is a serious clinical problem for which no suitable therapeutic strategies have been worked out so far. Recent studies suggest that the SCI and its pathophysiological responses could be altered by systemic exposure to nanoparticles. Thus, SCI when made in animals intoxicated with engineered nanoparticles from metals or silica dust worsened the outcome. On the other hand, drugs tagged with titanium (TiO(2)) nanoparticles or encapsulated in liposomes could enhance their neuroprotective efficacy following SCI. Thus, to expand our knowledge on nanoparticle-induced alterations in the spinal cord pathophysiology further research is needed. These investigations will help to develop new strategies to achieve neuroprotection in SCI, for example, using nanodrug delivery. New results from our laboratory showed that nanoparticle-induced exacerbation of cord pathology following trauma can be reduced when the suitable drugs tagged with TiO(2) nanowires were administered into the spinal cord as compared to those drugs given alone. This indicates that nanoparticles depending on the exposure and its usage could induce both neurotoxicity and neuroprotection. This review discusses the potential adverse or therapeutic utilities of nanoparticles in SCI largely based on our own investigations. In addition, possible mechanisms of nanoparticle-induced exacerbation of cord pathology or enhanced neuroprotection following nanodrug delivery is described in light of recently available data in this rapidly emerging field of nanoneurosciences.

The role of heat shock proteins in spinal cord injury

Heat shock proteins (HSPs) are normal intracellular proteins that are produced in greater amounts when cells are subjected to stress or injury. These proteins have been shown to play a key role in the modulation of the secondary injury that occurs after the initial spinal cord injury (SCI). Heat shock proteins normally act as molecular chaperones and are called protein guardians because they act to repair partially damaged proteins. Normally intracellular, HSPs can also be liberated into the systemic circulation to act as important inflammatory mediators. In the setting of SCI, HSP induction has been shown to be beneficial. These proteins are liberated primarily by acutely stressed microglial, endothelial, and ependymal cells. Heat shock proteins have also been shown to assist in the protection of motor neurons and to prevent chronic inflammation after SCI. In animal models, several experimental drugs have shown neuroprotective effects in the spinal cord and appear to function by modulating HSPs.

Acute administration of 3,4-methylenedioxymethamphetamine induces profound hyperthermia, blood-brain barrier disruption, brain edema formation, and cell injury

The psychostimulant 3,4-,ethylenedioxymethamphetamine (MDMA, "ecstasy") is known to induce hyperthermia and alterations in neurochemical metabolism in the CNS. However, the detailed cellular or molecular mechanisms behind MDMA-induced neurotoxicity are still not well known. Since MDMA induces profound hyperthermia that could lead to intense cellular stress and cause disruption of the blood-brain barrier (BBB), this investigation examined the effects of acute MDMA on BBB dysfunction, brain edema, and cell injury in rats and mice. When MDMA (40 mg/kg, i.p.) was administered to rats or mice, these animals exhibited profound behavioral disturbances (hyperactivity and hyperlocomotion) and hyperthermia (>40 to 41 degrees C) at 4 h. At this time, the leakage of Evans blue dye was evident, particularly in the cerebellum, hippocampus, cortex, thalamus, and hypothalamus. This effect was most pronounced in mice compared to rats. Marked increase in brain water along with Na(+), K(+), and Cl(-) content was also seen in the aforementioned brain regions. Presence of distorted neuronal and glial cells in brain regions associated with leakage of Evans blue is quite common in MDMA-treated animals. Increased albumin immunoreactivity, indicating breakdown of the BBB, and upregulation of glial fibrillary acidic protein (GFAP), suggesting activation of astrocytes, were seen in most brain regions showing edematous changes. Upregulation of heat-shock protein (HSP72) immunoreactivity in the nuclei and cell cytoplasm of the neurons located in the edematous brain regions are quite common. Taken together, these observations are the first to show that MDMA has the capacity to disrupt BBB permeability to proteins and to induce the formation of edema, probably by inducing hyperthermia and cellular stress, as evident with HSP overexpression leading to cell injury.

A select combination of neurotrophins enhances neuroprotection and functional recovery following spinal cord injury

Previously, we have shown that topical application of brain-derived neurotrophic factor (BDNF) or insulin-like growth factor 1 (IGF-1) given within 5 to 30 min after a focal trauma to the rat spinal cord attenuates spinal cord injury (SCI)-induced breakdown of the blood-spinal cord barrier (BSCB), edema formation, motor dysfunction, and cell injury. This investigation was undertaken to find out whether a combination of select neurotrophins (BDNF, glial cell line-derived neurotrophic factor [GDNF], neurotrophin 3 [NT-3], or nerve growth factor [NGF]) will further enhance the neuroprotective efficacy of growth factors in SCI. The neurotrophins (0.1-1 microg/10 microL in phosphate-buffered saline) were applied 30, 60, or 90 min after injury topically over the traumatized spinal cord either alone or in combination. The SCI was performed by making a unilateral incision into the right dorsal horn of the T10-T11 segment under Equithesin anesthesia. The rats were allowed to survive 5 h after trauma. Topical application of BDNF, GDNF, or NGF 30 min after SCI in high concentration (0.5 microg and 1 microg) significantly improved the motor functions and reduced the BSCB breakdown, edema formation, and cell injury seen at 5 h. These beneficial effects of neurotropins were absent when administered separately either 60 or 90 min after SCI. However, a combination of BDNF and GDNF (but not with NT-3 or NGF) given either 60 or 90 min after SCI significantly reduced the motor dysfunction and spinal cord pathology at 5 h. These novel observations suggest that a select group of neurotrophins in combination have potential therapeutic value for the treatment of SCI in clinical situations.

Cyclosporin-A enhances non-functional axonal growing after complete spinal cord transection

Therapeutic approaches that promote both neuroprotection and neuroregeneration would be valuable for spinal cord (SC) injury therapies. Cyclosporin-A (CsA) is an immunosuppressant that, due to its mechanism of action, could both protect and regenerate the neural tissue after injury. Previous studies have already demonstrated that intraperitoneal administration of CsA at a dose of 2.5 mg/kg/12 h during the first 2 days after SC contusion, followed by 5 mg/kg/12 h orally, diminishes tissue damage and improves motor recovery. In order to evaluate the effect of this CsA dosing regimen on axonal growth, we assessed motor recovery, presence of axons establishing functional connections and expression of GAP-43 in rats subjected to a complete SC transection. The Basso-Beattie-Bresnahan rating scale did not show difference in motor recovery of CsA or vehicle-treated rats. Moreover, somato-sensorial evoked potentials demonstrated no functional connections in the SC of these animals. Nevertheless, histological studies showed that: i) a significant number of CsA-treated rats presented growing axons, although they deviated perpendicularly at the edge of the stumps, surrounding them, ii) the expression of GAP-43 in animals treated with CsA was higher than that observed in the control group. Finally, anterograde tracing of the corticospinal tract of rats subjected to an incomplete SC transection showed no axonal fibers reaching the caudal stump. In summary, CsA administered at the dosing-regimen that promotes neuroprotection in SC contused rats induces both GAP-43 expression and axonal growth; however, it failed to generate functional connections in SC transected animals.

Methods to produce hyperthermia-induced brain dysfunction

The recent increase in the frequency and intensity of killer heat waves across the globe has aroused worldwide medical attention to exploring therapeutic strategies to attenuate heat-related morbidity and/or mortality. Death due to heat-related illnesses often exceeds >50% of heat victims. Those who survive are crippled with lifetime disabilities and exhibit profound cognitive, sensory, and motor dysfunction akin to premature neurodegeneration. Although more than 50% of the world populations are exposed to summer heat waves; our understanding of detailed underlying mechanisms and the suitable therapeutic strategies have still not been worked out. One of the basic reasons behind this is the lack of a reliable experimental model to simulate clinical hyperthermia. This chapter describes a suitable animal model to induce hyperthermia in rats (or mice) comparable to the clinical situation. The model appears to be useful for studying the effects of heat-related illnesses on changes in various organs and systems, including the central nervous system (CNS). Since hyperthermia is often associated with profound brain dysfunction, additional methods to examine some crucial parameters of brain injury, e.g., blood-brain barrier (BBB) breakdown and brain edema formation, are also described.

Nanoparticles aggravate heat stress induced cognitive deficits, blood-brain barrier disruption, edema formation and brain pathology

Our knowledge regarding the influence of nanoparticles on brain function in vivo during normal or hyperthermic conditions is still lacking. Few reports indicate that when nanoparticles enter into the central nervous system (CNS) they may induce neurotoxicity. On the other hand, nanoparticle-induced drug delivery to the brain enhances neurorepair processes. Thus, it is likely that the inclusion of nanoparticles in body fluid compartments alters the normal brain function and/or its response to additional stress, e.g., hyperthermia. New data from our laboratory show that nanoparticles derived from metals (e.g., Cu, Ag or Al, approximately 50-60nm) are capable of inducing brain dysfunction in normal animals and aggravating the brain pathology caused by whole-body hyperthermia (WBH). Thus, normal animals treated with nanoparticles (for 1 week) exhibited mild cognitive impairment and cellular alterations in the brain. Subjection of these nanoparticle-treated rats to WBH resulted in profound cognitive and motor deficits, exacerbation of blood-brain barrier (BBB) disruption, edema formation and brain pathology compared with naive animals. These novel observations suggest that nanoparticles enhance brain pathology and cognitive dysfunction in hyperthermia. The possible mechanisms of nanoparticle-induced exacerbation of brain damage in WBH and its functional significance in relation to our current knowledge are discussed in this review.

Post-traumatic application of brain-derived neurotrophic factor and glia-derived neurotrophic factor on the rat spinal cord enhances neuroprotection and improves motor function

We examined the potential efficacy of brain-derived neurotrophic factor (BDNF) and glial-derived neurotrophic factor (GDNF) applied over traumatized spinal cord, alone or in combination, for attenuating motor dysfunction, blood-spinal cord barrier (BSCB) breakdown, edema formation, and cell injury in a rat model. Under Equithesin anesthesia, spinal cord injury (SCI) was performed by making a unilateral incision into the right dorsal horn of the T10-11 segment. The rats were allowed to survive 5 hours after trauma. The BDNF or GDNF was applied (0.1 to 1 microg/10 microl in phosphate buffer saline) 30, 60, or 90 minutes after SCI. Topical application of BDNF or GDNF 30 minutes after SCI in high concentration (0.5 microg and 1 microg) significantly improved motor function and reduced BSCB breakdown, edema formation, and cell injury at 5 hours. These beneficial effects of neurotrophins were markedly absent when administered separately either 60 or 90 minutes after injury. However, combined application of BDNF and GDNF at 60 or 90 minutes after SCI resulted in a significant reduction in motor dysfunction and spinal cord pathology. These novel observations suggest that neurotrophins in combination have potential therapeutic value for the treatment of SCI in clinical situations.

Histamine receptors influence blood-spinal cord barrier permeability, edema formation, and spinal cord blood flow following trauma to the rat spinal cord

The role of histamine in edema formation, blood-spinal cord barrier (BSCB) permeability, and spinal cord blood flow (SCBF) following spinal cord injury (SCI) was examined using modulation of histamine H1, H2, and H3 receptors in the rat. Focal trauma to the spinal cord at the T10-11 level significantly increased spinal cord edema formation, BSCB permeability to protein tracers and SCBF reduction in the T9 and T12 segments. Pretreatment with histamine H1 receptor antagonist mepyramine (1 mg, 5 mg, and 10 mg/kg, i.p.) did not attenuate spinal pathophysiology following SCI. Blockade of histamine H2 receptors with cimetidine or ranitidine (1 mg, 5 mg, or 10 mg/kg 30 minutes before injury) significantly reduced early pathophysiological events in a dose dependent manner. The effects of ranitidine were far superior to cimetidine in identical doses. Pretreatment with a histamine H3 receptor agonist alpha-methylhistamine (1 mg and 2 mg/kg/i.p.), that inhibits histamine synthesis and release in the CNS, thwarted edema formation, BSCB breakdown, and SCBF disturbances after SCI. The lowest dose of histamine H3 agonist was most effective. Blockade of histamine H3 receptors with thioperamide (1 mg, 5 mg/kg, i.p.) exacerbated spinal cord pathology. These observations suggest that stimulation of histamine H3 receptors and blockade of histamine H2 receptors is neuroprotective in SCI.

Post-injury treatment with a new antioxidant compound H-290/51 attenuates spinal cord trauma-induced c-fos expression, motor dysfunction, edema formation, and cell injury in the rat

The neuroprotective efficacy of post-injury treatment with the antioxidant compound H-290/51 (10, 30, and 60 minutes after trauma) on immediate early gene expression (c-fos), blood-spinal cord barrier (BSCB) permeability, edema formation, and motor dysfunction was examined in a rat model of spinal cord injury (SCI). SCI was produced by a longitudinal incision into the right dorsal horn of the T10-11 segment under Equithesin anesthesia. Focal SCI in control rats resulted in profound up-regulation of c-fos expression, BSCB dysfunction, edema formation, and cell damage in the adjacent T9 and T12 segments at 5 hours. Pronounced motor dysfunction was present at this time as assessed using the Tarlov scale and the inclined plane test. Treatment with H-290/51 (50 mg/kg, p.o.) 10 and 30 minutes after SCI (but not after 60 minutes) markedly attenuated c-fos expression and motor dysfunction. In these groups, BSCB permeability, edema formation, and cell injuries were mildly but significantly reduced. These observations suggest that (i) antioxidants are capable of attenuating cellular and molecular events following trauma, and (ii) have the capacity to induce neuroprotection and improve motor function if administered during the early phase of SCI, a novel finding.