Induction of CL100 protein tyrosine phosphatase following transient forebrain ischemia in the rat brain

Excitotoxic inactivation of constitutive oxidative stress detoxification pathway in neurons can be rescued by PKD1

Excitotoxicity, a critical process in neurodegeneration, induces oxidative stress and neuronal death through mechanisms largely unknown. Since oxidative stress activates protein kinase D1 (PKD1) in tumor cells, we investigated the effect of excitotoxicity on neuronal PKD1 activity. Unexpectedly, we find that excitotoxicity provokes an early inactivation of PKD1 through a dephosphorylation-dependent mechanism mediated by protein phosphatase-1 (PP1) and dual specificity phosphatase-1 (DUSP1). This step turns off the IKK/NF-κB/SOD2 antioxidant pathway. Neuronal PKD1 inactivation by pharmacological inhibition or lentiviral silencing in vitro, or by genetic inactivation in neurons in vivo, strongly enhances excitotoxic neuronal death. In contrast, expression of an active dephosphorylation-resistant PKD1 mutant potentiates the IKK/NF-κB/SOD2 oxidative stress detoxification pathway and confers neuroprotection from in vitro and in vivo excitotoxicity. Our results indicate that PKD1 inactivation underlies excitotoxicity-induced neuronal death and suggest that PKD1 inactivation may be critical for the accumulation of oxidation-induced neuronal damage during aging and in neurodegenerative disorders.

Excitotoxicity due to excessive glutamate release causes oxidative stress and neuronal death, and is a feature of many brain diseases. Here the authors show that protein kinase D1 is inactivated by excitotoxicity in a model of stroke and that its activation can be neuroprotective.

Delayed neurovascular inflammation after mild traumatic brain injury in rats

INTRODUCTION

Experimental traumatic brain injury (TBI) elicits acute local inflammatory responses, including up-regulation of adhesion molecules and neutrophils in the injured brain. However, in clinical experiences there were at least three types of TBI, which included mild, moderate and severe types, and there would be different neuroinflammatory responses. This study investigated the inflammatory responses after mild TBI in rats.

METHODS

Adult male Sprague-Dawley rats (n = 40) were group-housed and injured using an impact method. Motor function was assessed 1-4 days after the injury by using a grip test (Grip strength meter; Singa). Blood samples collected from the rats before the injury and after the injury and the Intercellular adhesion molecule-1 (ICAM-1) level were measured.

RESULTS

The ICAM-1 expression from pre-injury to post-injury showed a significantly greater gradual elevation in the rats in the mild-injury group than in the moderate-injury group. The neurological function evaluated with grip test showed no deterioration of neurological function in the mild-injury group but gradual deterioration in the moderate-injury group.

CONCLUSION

These findings showed a delayed inflammatory reaction in the mild-injury group without progressive deterioration of neurological function. Therefore, in the moderate-injury group, no progression phase was observed.

Enhanced antitumor effects of DC-activated CIKs to chemotherapy treatment in a single cohort of advanced non-small-cell lung cancer patients

Cytokine-induced killer (CIK) cells show cytolytic activity against tumor. The purpose of this study was to evaluate the antitumor effect of dendritic cell (DC)-activated CIK cells in vitro and their clinical efficacy of DC-activated CIK cells in combination with chemotherapy (abbreviated below as chemotherapy plus DC + CIK) in patients with advanced non-small-cell lung cancer (NSCLC). A paired study was performed between 61 patients treated with chemotherapy alone (group 1) and 61 patients treated with chemotherapy plus DC + CIK cells (group 2). In group 2, 36 patients with adenocarcinoma and 18 patients with squamous cell carcinoma were analyzed for the survival rate. Compared to unstimulated CIK cells, DC-activated CIK cells significantly enhanced antitumor activity, increased the ratio of CD3(+)CD56(+) cells, promoted cell proliferation and lessened cell apoptosis. In the paired study, the 1- and 2-year overall survival rates in group 2 were 57.2 and 27.0 %, which were significantly higher than that of group 1 (37.3 and 10.1 %) (P < 0.05). There was no significant difference in the survival rate between the adenocarcinoma and squamous carcinoma patients in group 2. The present study suggests that DC-activated CIK cell has enhanced antitumor effects and chemotherapy plus DC + CIK cells improved the clinical outcomes of chemotherapy for advanced NSCLC patients.

Clinical study of autologous cytokine-induced killer cells for the treatment of elderly patients with diffuse large B-cell lymphoma

To evaluate the effectiveness and safety of autologous cytokine-induced killer (CIK) cells in elderly patients with diffuse large B-cell lymphoma. Peripheral blood mononuclear cells (PBMC) were isolated from nine elderly patients with diffuse large B-cell lymphoma. PBMCs were augmented by priming with interferon gamma (IFN-γ) followed by IL-2 and monoclonal antibody (mAb) against CD3. Autologous CIK cells (range 5 × 10(9)-1 × 10(10)) were then infused back to individual patients; infusion was repeated every 4 weeks for 32 weeks (eight cycles). Patients were assessed for changes in lymphocyte subgroup, tumor-related biological parameters, imaging characteristics, the condition of remission, quality of life (QOL), and survival. Prior to CIK infusion, two patients were in complete remission and seven patients were in partial remission. After autologous CIK cell transfusions, the proportion of CD3+, CD3+CD8+, and CD3+CD56+ cells were significantly increased compared with baseline (P < 0.05); whereas serum levels of β2-microglobulin and LDH were significantly decreased (P < 0.05). The lymphoma symptoms were reduced and QOL was improved (P < 0.05) in all patients. All patients achieved complete remission at study endpoint. No adverse reactions were reported. Autologous CIK cell immunotherapy is safe and efficacious for the treatment of elderly patients with diffuse large B-cell lymphoma.

Post-transcriptional regulation of the DUSP6/MKP-3 phosphatase by MEK/ERK signaling and hypoxia

DUSP6/MKP-3 is a cytoplasmic dual-specificity phosphatase specific for the MAP kinases ERK1/2. Previous data have shown that the MEK/ERK axis exerts a retro-control on its own signaling through transcriptional and post-translational regulation of DUSP6. We first confirm the key role of MEK/ERK in maintaining the levels of dusp6 mRNA, while PI3K/mTOR, p38 MAPK, and JNK signaling pathways had no significant effects. We further show that regulation of dusp6 mRNA stability plays a critical role in ERK-dependent regulation of dusp6 expression. Luciferase reporter constructs indicated that MEK/ERK signaling increased the half-life of dusp6 mRNA in a 3'untranslated region (3'UTR)-dependent manner. In addition, hypoxia, a hallmark of tumor growth, was found to increase both endogenous levels of dusp6 mRNA and the stability of the luciferase reporter constructs containing its 3'UTR, in a HIF-1-dependent manner. Nevertheless, a basal ERK activity was required for the response to hypoxia. Finally, Tristetraprolin (TTP), a member of the TIS11 CCCH zinc finger protein family, and PUM2, an homolog of drosophila pumilio, two proteins regulating mRNA stability reduced the levels of endogenous dusp6 mRNA and the activity of the dusp6/3'UTR luciferase reporter constructs. This study shows that post-transcriptional regulation is a key process in the control of DUSP6 expression.

Mitogen-activated protein (MAP) kinase/MAP kinase phosphatase regulation: roles in cell growth, death, and cancer

Mitogen-activated protein kinase dual-specificity phosphatase-1 (also called MKP-1, DUSP1, ERP, CL100, HVH1, PTPN10, and 3CH134) is a member of the threonine-tyrosine dual-specificity phosphatases, one of more than 100 protein tyrosine phosphatases. It was first identified approximately 20 years ago, and since that time extensive investigations into both mkp-1 mRNA and protein regulation and function in different cells, tissues, and organs have been conducted. However, no general review on the topic of MKP-1 exists. As the subject matter pertaining to MKP-1 encompasses many branches of the biomedical field, we focus on the role of this protein in cancer development and progression, highlighting the potential role of the mitogen-activated protein kinase (MAPK) family. Section II of this article elucidates the MAPK family cross-talk. Section III reviews the structure of the mkp-1 encoding gene, and the known mechanisms regulating the expression and activity of the protein. Section IV is an overview of the MAPK-specific dual-specificity phosphatases and their role in cancer. In sections V and VI, mkp-1 mRNA and protein are examined in relation to cancer biology, therapeutics, and clinical studies, including a discussion of the potential role of the MAPK family. We conclude by proposing an integrated scheme for MKP-1 and MAPK in cancer.

Global profiling of influence of intra-ischemic brain temperature on gene expression in rat brain

Mild to moderate differences in brain temperature are known to greatly affect the outcome of cerebral ischemia. The impact of brain temperature on ischemic disorders has been mainly evaluated through pathological analysis. However, no comprehensive analyses have been conducted at the gene expression level. Using a high-density oligonucleotide microarray, we screened 24000 genes in the hippocampus under hypothermic (32 degrees C), normothermic (37 degrees C), and hyperthermic (39 degrees C) conditions in a rat ischemia-reperfusion model. When the ischemic group at each intra-ischemic brain temperature was compared to a sham-operated control group, genes whose expression levels changed more than three-fold with statistical significance could be detected. In our screening condition, thirty-three genes (some of them novel) were obtained after screening, and extensive functional surveys and literature reviews were subsequently performed. In the hypothermic condition, many neuroprotective factor genes were obtained, whereas cell death- and cell damage-associated genes were detected as the brain temperature increased. At all intra-ischemic brain temperatures, multiple molecular chaperone genes were obtained. The finding that intra-ischemic brain temperature affects the expression level of many genes related to neuroprotection or neurotoxicity coincides with the different pathological outcomes at different brain temperatures, demonstrating the utility of the genetic approach.

Transient ischemia-induced expression and changes of tyrosine kinase A in the hippocampal dentate gyrus of the gerbil

The present study examined ischemia-related changes in tyrosine kinase A (trkA) immunoreactivity and its protein content in the dentate gyrus after 5 min of transient forebrain ischemia in gerbils. One day after ischemic insult, cresyl violet-positive polymorphic cells showed ischemic degeneration. The ischemia-induced changes in trkA immunoreactivity were found in the polymorphic layer (PL) and granule cell layer (GCL) of the dentate gyrus. In the sham-operated group, trkA immunoreactivity in the dentate gyrus was very weak. From 30 min after ischemia, trkA immunoreactivity was increased in the dentate gyrus and peaked in the dentate gyrus at 12 h after ischemia-reperfusion. Thereafter, trkA immunoreactivity was decreased time-dependently after ischemia-reperfusion. Four days after ischemic insult, trkA immunoreactivity was similar to that of the sham-operated group. In addition, it was found that ischemia-related changes in trkA protein content were similar to the immunohistochemical changes. These results suggest that the chronological changes of trkA in the dentate gyrus after transient forebrain ischemia may be associated with ischemic damage in polymorphic cells of the dentate gyrus.

Th1 bias in PBMC induced by multicycles of auto-CIKs infusion in malignant solid tumor patients

OBJECTIVE

The aim of this paper was to verify the feasibility and validity of autologous cytokine-induced killer cells (Auto-CIKs) treatments in solid malignancy patients.

METHODS

Amplification, phenotypic characteristics, antitumor cytotoxicity, and clinical and immunological response of Auto-CIKs derived from 66 cases of patients with solid tumor of different pathological types and at different clinical stages were examined in a large-scale clinical trail.

RESULTS

We found that seriousness of disease and metastasis status has no influence on effective components and antitumor activity of Auto-CIKs. Comparing the cytotoxicity against various tumor cells with LAKs, CIKs showed more effective cytotoxicity against NK sensitive and nonsensitive solid tumor cell lines, even at a low E/T ratio (6:1). In 20 patients receiving multicycles of Auto-CIKs infusions, 3 reached partial response (PR), 14 obtained stable disease (SD), and 3 died. Th1-kind cytokines secretion in peripheral blood mononuclear cells (PBMCs increased significantly, according with the enhanced cytolytic activity against K562 cells of them after multicycles of Auto- CIKs infusions.

CONCLUSIONS

Induction of special "Th1 bias" in PBMCs after multicycles of Auto-CIKs treatments suggested an immunological promoting effect of Auto-CIKs, which seems to be a suitable immunotherapy for those solid-malignance patients who are at high risk of relapse to prevent recurrence.

Comprehensive regional and temporal gene expression profiling of the rat brain during the first 24 h after experimental stroke identifies dynamic ischemia-induced gene expression patterns, and reveals a biphasic activation of genes in surviving tissue

In order to identify biological processes relevant for cell death and survival in the brain following stroke, the postischemic brain transcriptome was studied by a large-scale cDNA array analysis of three peri-infarct brain regions at eight time points during the first 24 h of reperfusion following middle cerebral artery occlusion in the rat. K-means cluster analysis revealed two distinct biphasic gene expression patterns that contained 44 genes (including 18 immediate early genes), involved in cell signaling and plasticity (i.e. MAP2K7, Sprouty2, Irs-2, Homer1, GPRC5B, Grasp). The first gene induction phase occurred at 0-3 h of reperfusion, and the second at 9-15 h, and was validated by in situ hybridization. Four gene clusters displayed a progressive increase in expression over time and included 50 genes linked to cell motility, lipid synthesis and trafficking (i.e. ApoD, NPC1, G3P-dehydrogenase1, and Choline kinase) or cell death-regulating genes such as mitochondrial CLIC. We conclude that a biphasic transcriptional up-regulation of the brain-derived neurotrophic factor (BDNF)-G-protein coupled receptor (GPCR)-mitogen-activated protein (MAP) kinase signaling pathways occurs in surviving tissue, concomitant with a progressive and persistent activation of cell proliferation signifying tissue regeneration, which provide the means for cell survival and postischemic brain plasticity.

Mild Intermittent Hypoxia Does Not Induce Stress Responses in the Neonatal Rat Brain

We previously demonstrated that intermittent hypoxia evokes persistent changes in extracellular striatal dopamine, locomotor activity and executive function, using a rodent model emulating apnea of prematurity in which rat pups are exposed to 20-second bursts of hypoxic gas mix containing 10% oxygen (60 events/h; 6 h/day) from postnatal days 7 to 11. To determine whether subtle repetitive hypoxic insults also induce expression of stress-related genes, we employed real-time RT-PCR to assay gene transcription in neonatal rats subjected to the same paradigm. In addition, we also measured expression of stress-induced transcripts in an age-matched cohort following a more severe oxidative stressor: permanent focal ischemia. Four transcripts were elevated following the ischemic insult: heat shock protein 70 (Hsp70), CL100, nurr77, and heme oxygenase-1. In contrast, these transcripts were not regulated in the majority of neonatal rats exposed to an intermittent hypoxia protocol. Hsp70 was strongly induced, and CL100 and nurr77 were slightly induced in only 2 of 11 post-hypoxic rats compared to controls. These data demonstrate that a single ischemic event elicits expression of specific stress-related genes, whereas 5 days of brief intermittent hypoxic insults typically do not. Thus, it is unlikely that the neurochemical and behavioral morbidity observed in juvenile and adult rodents exposed to intermittent hypoxia during a critical period of brain development are related to stress-induced changes in gene expression.

SAP and SLAM expression in anti-CD3 activated lymphocytes correlates with cytotoxic activity

Signalling lymphocyte activation molecule (SLAM)-associated protein (SAP) is a small protein that is mutant in humans with X-linked lymphoproliferative (XLP) disease. Patients with XLP disease are affected by fatal EBV infection and malignant B-cell lymphomas. The increased risk for B-cell lymphomas is suggested to result from impaired immunosurveillance of B-cell proliferation by T cells. In this study, we investigated the role of SLAM and SAP in activation of effector cells with cytotoxic activity, cytokine-induced killer (CIK) cells, which are generated by non-specific stimulation of the TCR and addition of exogenous IL-2. Agonistic TCR activation 1 day after preparation (day +1) resulted in cell activation, with a peak of SLAM on day +6 visible at both the protein and mRNA level as well as membrane detectable SLAM. This increase in SLAM expression correlated significantly with SAP expression at the mRNA level as well as at the protein level. Cytotoxic activity peaked 1 day after the observed SAP and SLAM peaks. At that point in time, IL-10 secretion, which was high during the early days of culture, decreased. In conclusion, activation of peripheral blood cells with agonistic anti-CD3 antibody and exogenous IL-2, as used for generation of CIK cells, results in significant SLAM and SAP activation 5 days after TCR stimulation. This peak correlates with cytotoxic activity against tumour cells. Expression of SLAM and SAP seems to be important in the activation of cytotoxic effector cells.

Tyrosine kinase A but not phosphacan/protein tyrosine phosphatase-ζ/β immunoreactivity and protein level changes in neurons and astrocytes in the gerbil hippocampus proper after transient forebrain ischemia

In the present study, ischemia-related changes in tyrosine kinase A (trkA) and phosphacan/protein tyrosine phosphatase-zeta/beta (PTP-zeta/beta) immunoreactivities and protein contents were examined in the hippocampus proper after transient forebrain ischemia for 5 min in a gerbil model. Our investigations showed that ischemia-induced changes occurred in trkA immunoreactivity in the hippocampal CA1 region, but not in the CA2/3 region of the hippocampus proper. In the sham-operated group, trkA immunoreactivity was barely detectable. trkA immunoreactivity increased from 30 min after ischemia and peaked at 12 h. Four days after ischemic insult, trkA immunoreactivity was observed in GFAP-immunoreactive astrocytes in the strata oriens and radiatum. In addition, we found that ischemia-related changes in trkA protein content were similar to immunohistochemical changes. On the other hand, PTP-zeta/beta immunoreactivities in the hippocampus proper were unaltered by forebrain ischemia. These results suggest that chronological changes of trkA after transient forebrain ischemia may be associated with an ischemic damage compensatory mechanism in CA1 pyramidal cells.

Interleukin 1beta and interleukin 6 relationship with paediatric head trauma severity and outcome

BACKGROUND

Based on the known inflammatory role of interleukins (IL), we evaluated IL-1beta and IL-6 expressions and their association with the severity of traumatic brain injury (TBI; Glasgow Coma Scale [GCS]) and the outcome (Glasgow Outcome Score [GOS]) recorded in a paediatric population.

DESIGN

The design was a perspective observational clinical study carried out in the paediatric intensive care unit of the University Hospital.

METHODS

We measured the IL-1beta and IL-6 levels in 14 children with severe TBI (patients) and in 12 children with obstructive hydrocephalus (control group). Cerebrospinal fluid (CSF) and plasma samples were collected 2 h (T1) and 24 h (T2) after TBI. Interleukins were assayed using the immunoenzymatic method.

RESULTS

The IL-1beta mean level was significantly lower than the IL-6 mean level both in the CSF and plasma of TBI children. In the CSF, the IL-1beta level increased from 55.71+/-72.79 pg/ml at T1 to 106.10+/-142.12 pg/ml at T2 and the IL-6 level increased from 405.43+/-280.28 pg/ml at T1 to 631.57+/-385.35 pg/ml at T2; a similar trend was observed in plasma. We found a statistically significant correlation between the increase in CSF and plasma interleukin levels between T1 and T2 and head injury severity (GCS<or=5) as well as poor outcome (GOS<or=3).

CONCLUSIONS

The increases in IL-1beta and IL-6 expression were correlated with head injury severity and were indicative of poor clinical outcome, reflecting an endogenous neuroinflammatory response after TBI.

Oxidative neuronal injury. The dark side of ERK1/2

The extracellular signal regulated protein kinases (ERK1/2) are essential for normal development and functional plasticity of the central nervous system. However, a growing number of recent studies in models of cerebral ischemia, brain trauma and neurodegenerative diseases implicate a detrimental role for ERK1/2 signaling during oxidative neuronal injury. Neurons undergoing oxidative stress-related injuries typically display a biphasic or sustained pattern of ERK1/2 activation. A variety of potential targets of reactive oxygen species and reactive nitrogen species could contribute to ERK1/2 activation. These include cell surface receptors, G proteins, upstream kinases, protein phosphatases and proteasome components, each of which could be direct or indirect targets of reactive oxygen or nitrogen species, thereby modulating the duration and magnitude of ERK1/2 activation. Neuronal oxidative stress also appears to influence the subcellular trafficking and/or localization of activated ERK1/2. Differences in compartmentalization of phosphorylated ERK1/2 have been observed in diseased or injured human neurons and in their respective animal and cell culture model systems. We propose that differential accessibility of ERK1/2 to downstream targets, which is dictated by the persistent activation of ERK1/2 within distinct subcellular compartments, underlies the neurotoxic responses that are driven by this kinase.

Profiling of genes associated with transcriptional responses in mouse hippocampus after transient forebrain ischemia using high-density oligonucleotide DNA array

Several cascades of changes in gene expression have been shown to be involved in the neuronal injury after transient cerebral ischemia; however, little is known about the profile of genes showing alteration of expression in a mouse model of transient forebrain ischemia. We analyzed the gene expression profile in the mouse hippocampus during 24 h of reperfusion, after 20 min of transient forebrain ischemia, using a high-density oligonucleotide DNA array. Using statistical filtration (Welch's ANOVA and Welch's t-test), we identified 25 genes with a more than 3.0-fold higher or lower level of expression on average, with statistical significance set at p<0.05, in at least one ischemia-reperfusion group than in the sham group. Using unsupervised clustering methods (hierarchical clustering and k-means clustering algorithms), we identified four types of gene expression pattern that may be associated with the response of cell populations in the hippocampus to an ischemic insult in this mouse model. Functional classification of the 25 genes demonstrated alterations of expression of several kinds of biological pathways, regulating transcription (Bhlhb2, Jun, c-fos, Egr1, Egr2, Fosb, Junb, Ifrd1, Neurod6), the cell cycle (c-fos, Fosb, Jun, Junb, Dusp1), stress response (Dusp1, Dnajb1, Dnaja4), chaperone activity (Dnajb1, Dnaja4) and cell death (Ptgs2, Gadd45g, Tdag51), in the mouse hippocampus by 24 h of reperfusion. Using hierarchical clustering analysis, we also found that the same 25 genes clearly discriminated between the sham group and the ischemia-reperfusion groups. The alteration of expression of 25 genes identified in this study suggests the involvement of these genes in the transcriptional response of cell populations in the mouse hippocampus after transient forebrain ischemia.

Erasure of kinase phosphorylation in astrocytes during oxygen-glucose deprivation is controlled by ATP levels and activation of phosphatases

We have examined the relationship between adenosine triphosphate (ATP) concentration and loss of maintenance of kinase-signalling cascades in primary cortical astrocytes during oxygen-glucose deprivation (OGD) as this may constitute an irreversible step that commits astrocytes to cell death. We report that the phosphorylation of Akt, ERK, JNK and p38 kinases, whose activities depend on serine, threonine and tyrosine phosphorylation, were all increased during OGD. All these phosphorylations were reduced to below detection limits when ATP levels were less than 10% of normal levels. Using ERK and Akt as representative examples, we show that this erasure is not irreversible as both ERK and Akt phosphorylations can be partially restored by addition of glucose under anoxic conditions. We further investigated whether OGD caused any change in phosphatase activity. The PP1/PP2A phosphatase inhibitors okadaic acid and caliculyn A, but not cyclosporine A, delayed the removal of ERK and Akt phosphorylation under OGD. By comparing the extent of phosphorylation increase under OGD and normoxic conditions, we calculate that phosphatase activity was increased by approximately 3.6-fold during OGD. These data show that ATP levels control an important checkpoint in kinase function, and that ATP levels may need to be considered when studies of kinase function in relation to OGD are conducted.

Analysis of the innate and adaptive phases of allograft rejection by cluster analysis of transcriptional profiles

Both clinical and experimental observations suggest that allograft rejection is a complex process with multiple components that are, at least partially, functionally redundant. Studies using graft recipients deficient in various genes including chemokines, cytokines, and other immune-associated genes frequently produce a phenotype of delayed, but not indefinitely prevented, rejection. Only a small subset of genetic deletions (for example, TCR(alpha) or beta, MHC I and II, B7-1 and B7-2, and recombinase-activating gene) permit permanent graft acceptance suggesting that rejection is orchestrated by a complex network of interrelated inflammatory and immune responses. To investigate this complex process, we have used oligonucleotide microarrays to generate quantitative mRNA expression profiles following transplantation. Patterns of gene expression were confirmed with real-time PCR data. Hierarchical clustering algorithms clearly differentiated the early and late phases of rejection. Self-organizing maps identified clusters of coordinately regulated genes. Genes up-regulated during the early phase included genes with prior biological functions associated with ischemia, injury, and Ag-independent innate immunity, whereas genes up-regulated in the late phase were enriched for genes associated with adaptive immunity.

Interactions between dendritic cells and cytokine-induced killer cells lead to an activation of both populations

Dendritic cells (DCs) are major antigen-presenting cells. They are capable of capturing and processing tumor antigens, expressing lymphocyte costimulatory molecules, and secreting cytokines to initiate immune responses. Here, the authors tested the effect of cytokine-induced killer (CIK) cells, a population that includes CD3+CD56+ cells (natural killer T cells), with regard to their capacity to immunomodulate DCs. Cytokine-induced killer cells were cocultured with autologous DCs generated from peripheral blood mononuclear cells. Expression of markers typical for both populations was measured using flow cytometry, and secretion of interleukin (IL)-12 was determined using enzyme-linked immunosorbent assays. Cytotoxicity assays were performed to investigate the role of IL-12 and the importance of cell-cell interactions. Considering this, receptors for IL-12 and CD40 were blocked and cocultures were performed with cell culture inserts. Coculture of CIK cells led to a significant increase of DC-specific, costimulatory, and antigen-presenting molecules in DC cultures. In addition, coculture resulted in a dramatically increase of IL-12 secretion by DCs and to a significant increase in cytotoxic activity of CIK cells toward carcinoma cells. Blockage of IL-12 uptake decreased the cytolytic activity of CIK cells. Cytokine secretion was shown to be important for activation of CIK cells, and also cellular interactions between DCs and effector cells caused a higher cytolytic capacity. Interactions between DCs and CIK cells caused changes in the surface molecule expression of both populations, led to an increase of IL-12 secretion, and rendered an improved cytotoxic activity. The natural killer T cell subpopulation seems to be responsible for this effect. Therefore, coculture of DCs with CIK cells may have a major impact on immunotherapeutic protocols for patients with cancer.

Ex vivo purging of stem cell autografts using cytotoxic cells

Autologous stem cell transplantation (SCT) is the treatment alternative offered to patients that cannot benefit from allogeneic transplantation due to lack of suitable donor or age limitations. However, the outcome of autologous SCT is largely hindered by the high relapse rate. Two major factors can account for relapse after autologous SCT: the persistence of residual malignant cells resistant to chemo/radiotherapy left either in the body or in the autograft. Therefore, the rationale for purging autografts of residual malignant cells comes from the limitations of conventional high-dose chemo/radiotherapy in achieving a complete eradication of residual tumor cells in the marrow. To date, different purging modalities have been exploited. Immunological methods of purging present the advantage of being non-cross-reactive with conventional chemotherapy. These immunologic methods include depletion using antibody targeting of the malignant cells, ex vivo activation/generation of the autologous cytotoxic cells, in particular that of natural killer/lymphokine-activated killer (NK/LAK) and cytokine-induced killer (CIK) cells, and ex vivo purging of autografts using cytotoxic cell lines. The generation of ex vivo-expanded and activated autologous cytotoxic cells (CTL or NK) has generated increasing interest for the treatment of different malignancies. Unfortunately, the isolation and expansion of these cells have proven to be technically difficult. As an alternative, the use of cytotoxic cell lines as immune effectors has been proposed. The two available human cytotoxic cell lines TALL104 and NK-92 are currently in clinical trials and a number of studies have suggested their effectiveness as an immunotherapeutic agent including for ex vivo purging of autografts.

Effect of neutropenia and granulocyte colony stimulating factor-induced neutrophilia on blood-brain barrier permeability and brain edema after traumatic brain injury in rats

OBJECTIVE

Granulocyte colony stimulating factor (GCSF) has been used to increase systemic absolute neutrophil count (ANC) in patients with severe traumatic brain injury to reduce nosocomial infection risk. However, the effect of increasing systemic ANC on the pathogenesis of experimental traumatic brain injury has not been studied. Thus, we evaluated the effect of systemic ANC on blood-brain barrier (BBB) damage and brain edema after traumatic brain injury in rats.

DESIGN

Experimental study.

SETTING

Research laboratory at the University of Pittsburgh, PA.

SUBJECTS

Forty-three adult male Sprague-Dawley rats.

INTERVENTIONS

Protocol I: rats were randomized to receive either vinblastine sulfate to reduce ANC, GCSF to increase ANC, or saline before controlled cortical impact (CCI) of moderate overall severity. Evans blue was used to assess BBB damage at 4-24 hrs after CCI. Protocol II: rats received GCSF or saline before CCI. Brain edema was estimated at 24 hrs using wet - dry) / wet weight method. Protocol III: rats received GCSF or saline before CCI. Brain neutrophil accumulation was estimated at 24 hrs using a myeloperoxidase assay.

MEASUREMENTS AND MAIN RESULTS

Physiologic variables were controlled before CCI was maintained at normal in all animals before traumatic brain injury. No rats were anemic, hypoglycemic, or hypotensive before CCI. Protocol I: compared with control, systemic ANC decreased in vinblastine-treated rats and increased in GCSF-treated rats. BBB damage correlated with systemic ANC. Protocol II: mean systemic ANC before traumatic brain injury increased 15-fold in rats given GCSF vs. control; however no difference in brain edema was observed at 24 hrs after injury between groups. Protocol III: median systemic ANC at the time of CCI was increased ten-fold in rats given GCSF vs. control. No difference in brain myeloperoxidase activity 24 hrs after CCI was observed in rats treated with GCSF vs. control.

CONCLUSIONS

Systemic ANC influences BBB damage after traumatic brain injury produced by CCI. Because BBB damage and brain edema are discordant, mechanisms other than BBB damage likely predominate in the pathogenesis of brain edema after contusion. The implications of increased BBB permeability with the administration of GCSF in our model remains to be determined. Increasing systemic ANC before CCI with GCSF administration does not increase posttraumatic brain neutrophil accumulation or brain edema after CCI in rats. The finding that neutrophil infiltration is not enhanced by systemic neutrophilia suggests that the ability of GCSF-stimulated neutrophils to migrate into injured tissue may be impaired. Further studies are needed to evaluate the effects of GCSF administration on secondary injury and functional outcome in experimental models of traumatic brain injury.

Ischemia reperfusion-induced dynamic changes of protein tyrosine phosphorylation during human lung transplantation

BACKGROUND

We have recently demonstrated that more than 20% of lung cells undergo apoptosis within the first 2 hr of graft reperfusion after human lung transplantation. It has been found that changes of protein tyrosine phosphorylation are involved in the regulation of apoptosis in various cell types.

METHODS

To determine the protein tyrosine phosphorylation status and related biochemistry changes, lung tissue biopsies were collected from six human lung transplant procedures after cold ischemic preservation (2-5 hr at 4 degrees C), after completing the implantation procedure (approximately 1 hr), and 1 or 2 hr after graft reperfusion. Western blotting was performed to determine protein tyrosine phosphorylation and several signal transduction proteins. Protein tyrosine kinase (PTK) and protein tyrosine phosphatase (PTP) activities were also measured.

RESULTS

Protein tyrosine phosphorylation was significantly increased after lung implantation and before reperfusion, and significantly decreased during the first 2 hr of graft reperfusion. The activity of Src PTKs was reduced by 50% during graft reperfusion, which was associated with a decrease of Src proteins and human actin filament associated protein, a cofactor for Src activation. PTP activity significantly decreased after lung implantation and remained at a low level 1 hr after reperfusion. After 2 hr of reperfusion, however, PTP activity returned to the basal level.

CONCLUSION

These dynamic changes of PTK and PTP likely explain the observed alterations of protein tyrosine phosphorylation. The significant decrease in protein tyrosine phosphorylation may be related to the observed apoptotic cell death during human lung transplantation.

Interleukin-8 is increased in cerebrospinal fluid of children with severe head injury

OBJECTIVE

To determine interleukin (IL)-8 concentrations in ventricular cerebrospinal fluid from children with severe traumatic brain injury (TBI).

DESIGN

Prospective study.

SETTING

University children's hospital.

PATIENTS

Twenty-seven children hospitalized with severe TBI (Glasgow Coma Scale score < or =8), seven children with cerebrospinal fluid culture-positive bacterial meningitis, and twenty-four age-equivalent controls.

INTERVENTIONS

Placement of an intraventricular catheter and continuous drainage of cerebrospinal fluid.

MEASUREMENTS AND MAIN RESULTS

Median [range] cerebrospinal fluid IL-8 concentration in children with TBI (0-12 hrs) (4,452.5 [0-20,000] pg/mL) was markedly greater than that in controls (14.5 [0-250]) (p < .0001) and equivalent to concentrations in children with meningitis (5,300 [1,510-22,000] pg/mL) (p = .33). Cerebrospinal fluid IL-8 remained increased in children with severe TBI for up to 108 hrs after injury. Univariate logistic regression analysis demonstrated an association between cerebrospinal fluid IL-8 and child abuse (p = .07) and mortality (p = .01). Multivariate analysis demonstrated a strong, independent association between cerebrospinal fluid IL-8 and mortality (p = .01).

CONCLUSIONS

The data are consistent with an acute inflammatory component of TBI in children and suggest an association between cerebrospinal fluid IL-8 and outcome after TBI. IL-8 may represent a potential target for anti-inflammatory therapy.

Differential effects of traumatic brain injury on vesicular acetylcholine transporter and M2 muscarinic receptor mRNA and protein in rat

Experimental traumatic brain injury (TBI) produces cholinergic neurotransmission deficits that may contribute to chronic spatial memory deficits. Cholinergic neurotransmission deficits may result from presynaptic alterations in the storage and release of acetylcholine (ACh) or from changes in the receptors for ACh. The vesicular ACh transporter (VAChT) mediates accumulation of ACh into secretory vesicles, and the M2 muscarinic receptor subtype can modulate cholinergic neurotransmission via a presynaptic inhibitory feedback mechanism. We examined the effects of controlled cortical impact (CCI) injury on hippocampal VAChT and M2 muscarinic receptor subtype protein and medial septal mRNA levels at 4 weeks following injury. Rats were anesthetized and surgically prepared for CCI injury (4 m/sec, 2.5 to 2.9 mm in depth) and sham surgery. Animals were sacrificed, and coronal sections (35 microm thick) were cut through the dorsal hippocampus for VAChT and M2 immunohistochemistry. Semiquantitative measurements of VAChT and M2 protein in hippocampal homogenates from injured and sham rats were assessed with Western blot analysis. Changes in VAChT and M2 mRNA levels were evaluated by reverse transcriptase polymerase chain reaction (RT-PCR). At 4 weeks after injury, both immunohistochemical and Western blot methods demonstrated an increase in hippocampal VAChT protein. An increase in VAChT mRNA was also observed. Immunohistochemistry demonstrated a loss of M2; however, there was no significant change in M2 mRNA levels in comparison with sham controls. These changes may represent a compensatory response of cholinergic neurons to increase the efficiency of ACh neurotransmission chronically after TBI through differential transcriptional regulation.

Effect of traumatic brain injury in mice deficient in intercellular adhesion molecule-1: assessment of histopathologic and functional outcome

Intercellular adhesion molecule-1 (ICAM-1) is an adhesion molecule of the immunoglobulin family expressed on endothelial cells that is upregulated in brain as part of the acute inflammatory response to traumatic brain injury (TBI). ICAM-1 mediates neurologic injury in experimental meningitis and stroke; however, its role in the pathogenesis of TBI is unknown. We hypothesized that mutant mice deficient in ICAM-1 (-/-) would have decreased neutrophil accumulation, diminished histologic injury, and improved functional neurologic outcome versus ICAM-1 +/+ wild type control mice after TBI. Anesthetized ICAM-1 -/- mice and wild-type controls were subjected to controlled cortical impact (CCI, 6 m/sec, 1.2 mm depth). Neutrophils in brain parenchyma and ICAM-1 on vascular endothelium were assessed by immunohistochemistry in cryostat brain sections from the center of the contusion 24 h after TBI (n = 4/group). Separate groups of wild-type and ICAM-1-deficient mice (n = 9-10/group) underwent motor (wire grip test, days 1-5) and cognitive (Morris water maze [MWM], days 14-20) testing. Lesion volume was determined by image analysis 21 days following TBI. Robust expression of ICAM-1 was readily detected in choroid plexus and cerebral endothelium at 24 h in ICAM-1 +/+ mice but not in ICAM-1 -/- mice. No differences between groups were observed in brain neutrophil accumulation (9.4 +/- 2.2 versus 11.1 +/- 3.0 per x100 field, -/- versus +/+), wire grip score, MWM latency, or lesion volume (7.24 +/- 0.63 versus 7.21 +/- 0.45 mm3, -/- versus +/+). These studies fail to support a role for ICAM-1 in the pathogenesis of TBI.

A novel rat CC chemokine, identified by targeted differential display, is upregulated in brain inflammation

A novel rat chemokine, termed ST38, was identified through its upregulation in ischemic brain tissue using a biased differential display technique targeting mRNAs with regulatory AUUUA-motifs typically found in transcripts of cytokine and immediate early genes. ST38 transcripts were transiently induced in ischemic cortex between 4 and 24 h after middle cerebral artery occlusion. ST38 is a member of the CC chemokine family, closely related to human Exodus-1. The gene of the mouse ST38 homologue was mapped to the central region of chromosome 1. In experimental autoimmune panencephalomyelitis ST38 expression correlated with the onset of inflammation and was significantly reduced by TNF-neutralization in vivo. Inflammatory stimuli induce ST38 transcription in astrocyte, microglia and macrophage cultures. These findings suggest a role of ST38 in the control of neuroinflammatory tissue responses.

Cocaine and fluoxetine induce the expression of the hVH-5 gene encoding a MAP kinase phosphatase

A novel class of immediate early genes that encode enzymes of the MAP kinase phosphatase family has recently been described. These enzymes are dual-specificity protein phosphatases and some show tissue-specific distribution, like the hVH-5 gene (homologue of vaccinia virus H1 phosphatase gene clone 5), which is expressed predominantly in the adult brain. In this paper, we investigated whether the hVH-5 gene is induced by psychostimulants in rat brain, as has been demonstrated for immediate early genes encoding transcription factors. Using in situ hybridization, we found that i.p. injection of cocaine, amphetamine and caffeine induced hVH-5 mRNA expression within 40 min in the nucleus accumbens (NAc), caudate putamen, frontal cortex and hippocampus, with a maximal effect in the NAc. The cocaine-induced hVH-5 gene induction involves the serotonergic system, since it was abolished in the NAc by lesioning serotonergic raphé projections with 5,7-dihydroxytryptamine. Moreover, the effect of cocaine was fully mimicked by the selective serotonin uptake inhibitor fluoxetine. In contrast to what has been described for c-fos and egr-1 immediate early genes, we found that hVH-5 mRNA expression in the NAc and hippocampus was as significant after repeated cocaine injections for 10 days as after a single injection. The considerable and prolonged induction of the MAP kinase phosphatase hVH-5 gene by psychostimulant drugs in postmitotic brain cells, particularly in the NAc, could indicate that MAP kinase substrates are involved in the reinforcing properties of drugs of abuse.

Soluble adhesion molecules in CSF are increased in children with severe head injury

Leukocyte-endothelial adhesion molecules, critical to the development of acute inflammation, are expressed in brain as part of the acute inflammatory response to traumatic brain injury (TBI). We measured the concentrations of the adhesion molecules P-selectin, ICAM-1, E-selectin, L-selectin, and VCAM-1 in ventricular cerebrospinal fluid (CSF) from children with severe TBI (Glasgow coma score < 8) and compared these findings with those from children with bacterial meningitis. P-selectin, an adhesion molecule associated with ischemia/reperfusion, was increased in children with TBI versus meningitis and control. Univariate and multivariate regression analyses demonstrated associations between CSF P-selectin and child abuse and age of < 4 years, and a significant, independent association between CSF intercellular adhesion molecule-1 (ICAM-1) and child abuse. These results are consistent with a specific acute inflammatory component to TBI in children. Future studies of secondary injury mechanisms and therapy after TBI should assess on the roles of P-selectin and ICAM-1 in injury and repair processes in brain after TBI.

A complex program of striatal gene expression induced by dopaminergic stimulation

Dopamine acting in the striatum is necessary for normal movement and motivation. Drugs that change striatal dopamine neurotransmission can have long-term effects on striatal physiology and behavior; these effects are thought to involve alterations in gene expression. Using the 6-hydroxydopamine lesion model of Parkinson's disease and differential display PCR, we have identified a set of more than 30 genes whose expression rapidly increases in response to stimulation of striatal dopamine D1 receptors. The induced mRNAs include both novel and previously described genes, with diverse time courses of expression. Some genes are expressed at near-maximal levels within 30 min, whereas others show no substantial induction until 2 hr or more after stimulation. Some of the induced genes, such as CREM, CHOP, and MAP kinase phosphatase-1, may be components of a homeostatic response to excessive stimulation. Others may be part of a genetic program involved in cellular and synaptic plasticity. A very similar set of genes is induced in unlesioned animals by administration of the psychostimulant cocaine or the antipsychotic eticlopride, although in distinct striatal cell populations. In contrast to some previously described early genes, most of the novel genes are not induced in cortex by apomorphine, indicating specificity of induction. Thus we have identified novel components of a complex, coordinated genetic program that is induced in striatal cells in response to various dopaminergic manipulations.

The effect of brain temperature on acute inflammation after traumatic brain injury in rats

The effect of varying brain temperature on neutrophil accumulation in brain and the expression of E-selectin and intercellular adhesion molecule-1 (ICAM-1) on cerebrovascular endothelium after controlled cortical impact (CCI) was studied in rats. Sprague Dawley rats were anesthetized and subjected to CCI to the left parietal cortex. Ten minutes after CCI, brain temperature was modulated and maintained at 32 degrees C, 37 degrees C, or 39 degrees C (n = 8 per group) for 4 h. Rats were then decapitated and immunohistochemistry on brain sections was performed using monoclonal antibodies (MoAb) that recognize neutrophils (RP-3), ICAM-1 (TM-8, Athena Neurosciences), or MoAb that react with E-selectin (La-Roche). Each of these markers was quantified in 100 x fields. Neutrophil accumulation was also quantified with myeloperoxidase (MPO) assay. Absolute neutrophil count (ANC) was measured in blood samples before and 1 h and 4 h after CCI. Neutrophil accumulation in injured brain was decreased in rats maintained at 32 degrees C vs 39 degrees C (4-fold difference as assessed by immunohistochemistry, p < 0.05; 8-fold difference as assessed by MPO assay, p < 0.05). Peripheral blood ANC was not affected by temperature. E-selectin was induced on cerebrovascular endothelium after CCI (p < 0.05), but was only decreased modestly at 32 degrees C versus 39 degrees C (p = 0.11). ICAM-1 was not upregulated on cerebrovascular endothelium at this early time following CCI. Neutrophil accumulation is directly dependent on brain temperature during the initial 4 h after CCI. This appears to be mediated by mechanisms other than effects of temperature on E-selectin or ICAM-1 expression or systemic ANC.

Cellular immunotherapy and autologous transplantation for hematologic malignancy

The success of allogeneic transplantation is in part due to the immunotherapeutic effect mediated by the graft. Autologous transplantation is hampered by the absence of this effect, leading to a higher relapse rate. We have conducted a series of studies designed to augment the immunologic activity of the graft after autologous transplant with a view towards introducing an autologous graft-versus-tumor effect that could decrease the rate of relapse after autologous transplant. These studies have included IL-2 activation of marrow followed by post-transplant infusional IL-2, the development of a novel protocol for the generation of highly efficient cytotoxic effector cells, termed cytokine-induced killer (CIK) cells, with broad and potent antitumor activity. In order to determine the potential for generating peptide-specific cytolytic T cells, studies have been conducted upon transducing antigen-presenting cells (APC) with AAV vector-mediated gene transfer, a vector capable of transducing non-proliferating target cells. Transduction of human monocytes and macrophages resulted in high expression of the transduced gene. This latter study forms the basis for determining whether genetic modification of APC can potentiate specific immune responses to tumor-specific gene products. Taken together, these strategies will hopefully increase the therapeutic efficacy of autologous transplantation.

Chronic myeloid leukemia as an immunological target

Various clinical observations have implicated T cells in the control of chronic myeloid leukemia (CML). These observations have in recent years been supported by laboratory results indicating the presence of CML-specific T cells in the lymphocyte repertoire of both normal healthy individuals and disease-bearing patients. Both MHC-unrestricted and MHC-restricted immune effector mechanisms are involved. Donor lymphocyte infusion has produced encouraging GvL effects. However, future adoptive immunotherapy may depend on the isolation and generation of leukemia-specific T cells. Although many proteins may potentially act as leukemia antigens in CML for MHC-restricted cytotoxicity, the bcr-abl fusion protein has been most extensively investigated. There is now much evidence to suggest that the bcr-abl junctional peptides are capable of eliciting both CD4 and CD8 responses in normal healthy donors and CML patients. Furthermore, the T-cell lines generated react with autologous or HLA-matched fresh CML cells, suggesting that the bcr-abl fusion protein can be processed in vivo so that the joining segment is bound to HLA molecules in a configuration and concentration similar to those of the immunizing peptide for antigen recognition by the antigen-specific T-cell receptor. These results also indicate that the bcr-abl junctional peptides may be used for immunotherapy of CML. Other strategies available for immunotherapy of CML include immunologically or genetically manipulated donor T-cell infusion, the use of cytokines, adoptive immunotherapy with leukemia-reactive T-cells expanded ex vivo, and immune gene therapy. Novel and rational immunotherapy may therefore play an important adjuvant role in future in the management of patients with CML.

Mitogen-activated protein kinase phosphatase-1 in rat arterial smooth muscle cell proliferation

Smooth muscle cell proliferation and migration is important in arteriosclerosis. In this process, cytokines and growth factors are upregulated and bind to their respective receptors, which in turn stimulate mitogen-activated protein (MAP) kinases. MAP kinases then relay signals to the nucleus that activate quiescent smooth muscle cells. Phosphatases downregulate MAP kinases. We investigated the role of a dual-specificity tyrosine phosphatase, MAP kinase phosphatase-1 (MKP-1), in smooth muscle cell proliferation. MKP-1 expression was high in arterial tissue by Northern analysis, and MKP-1 message was detected mainly in the arterial smooth muscle layer by in situ hybridization. After balloon injury of the rat carotid artery, expression of MKP-1 decreased greatly, whereas that of MAP kinases, especially p44 MAP kinase, increased. The time course of the reduction in MKP-1 message correlated with increased tyrosine phosphorylation and elevated p44 MAP kinase enzymatic activity. In rat arterial smooth muscle cells overexpressing MKP-1, growth was arrested in the G1 phase and entry into the S phase was blocked. A reduction in MKP-1 expression may contribute in part to proliferation of smooth muscle cells after vascular injury, possibly through a decrease in dephosphorylation of p44 MAP kinase.

PRL-1, a protein tyrosine phosphatase, is expressed in neurons and oligodendrocytes in the brain and induced in the cerebral cortex following transient forebrain ischemia

Protein tyrosine phosphorylation is thought to play an important role in the regulation of neural function. We reported previously that CL100, a cytoplasmic type protein tyrosine phosphatase (PTP), was induced after transient forebrain ischemia. In the present study, changes in the mRNA levels after ischemia of PRL-1, a cytoplasmic type PTP and immediate-early gene similar to CL100, was examined. In situ hybridization histochemistry showed that PRL-1 mRNA was expressed in normal adult rats in neurons and oligodendrocytes in widespread regions including the cerebral cortex, hippocampus and cerebellum. PRL-1 mRNA was expressed in the developing brains on embryonic days 15 and 19 and postnatal day 1. Northern blot analysis showed that PRL-1 mRNA was induced from 6 h to 9 h after reperfusion in the cerebral cortex of postischemic rats. These findings suggest that PRL-1 plays a role in neurons and oliogodendrocytes, and that expression of PRL-1 mRNA is regulated by a mechanism different from those of other immediate-early genes such as c-fos and c-jun.

Reduced expression of kan-1 (encoding putative bile acid-CoA-amino acid N-acyltransferase) mRNA in livers of rats after partial hepatectomy and during sepsis

We isolated a cDNA clone, kan-1, from a rat liver cDNA library using a reverse transcriptase PCR cloning method. The kan-1 cDNA encoded a polypeptide of 420 amino acids, and was 70 and 69% identical in nucleotide and amino acid sequences respectively with human liver bile acid-CoA-amino acid N-acyltransferase (BAT). Thus Kan-1 is probably a rat homologue of human BAT (rBAT). Kan-1/rBAT mRNA was mainly expressed in the livers of adult rats and rats immediately after, but not before, birth. It was expressed in the hepatocytes, the sinusoidal endothelial cells and the Kupffer cells of the liver. An anti-Kan-1/rBAT polyclonal antibody detected a protein of molecular mass 46 kDa in the liver. After partial hepatectomy, the levels of Kan-1/rBAT mRNA decreased at 6 and 12 h in the regenerating liver. In a sepsis model, hepatic expression of Kan-1/rBAT mRNA decreased at 6 and 12 h after caecal ligation and puncture. The kinetics of Kan-1/rBAT mRNA expression suggests that it may play a role in acute-phase reactions.