transforming-growth-factor-beta and Brain-Ischemia

Hemorrhagic transformation (HT) is a common complication of ischemic stroke that is exacerbated by thrombolytic therapy. Methods to better prevent, predict, and treat HT are needed. In this review, we summarize studies of HT in both animals and humans. We propose that early HT (<18 to 24 hours after stroke onset) relates to leukocyte-derived matrix metalloproteinase-9 (MMP-9) and brain-derived MMP-2 that damage the neurovascular unit and promote blood-brain barrier (BBB) disruption. This contrasts to delayed HT (>18 to 24 hours after stroke) that relates to ischemia activation of brain proteases (MMP-2, MMP-3, MMP-9, and endogenous tissue plasminogen activator), neuroinflammation, and factors that promote vascular remodeling (vascular endothelial growth factor and high-moblity-group-box-1). Processes that mediate BBB repair and reduce HT risk are discussed, including transforming growth factor beta signaling in monocytes, Src kinase signaling, MMP inhibitors, and inhibitors of reactive oxygen species. Finally, clinical features associated with HT in patients with stroke are reviewed, including approaches to predict HT by clinical factors, brain imaging, and blood biomarkers. Though remarkable advances in our understanding of HT have been made, additional efforts are needed to translate these discoveries to the clinic and reduce the impact of HT on patients with ischemic stroke.

Topics: Animals; Biomarkers; Blood-Brain Barrier; Brain Ischemia; Cerebral Hemorrhage; Enzyme Activation; HMGB1 Protein; Humans; Peptide Hydrolases; Protease Inhibitors; Risk Factors; Signal Transduction; src-Family Kinases; Stroke; Thrombolytic Therapy; Time Factors; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A

Recent studies have indicated that proteins in the transforming growth factor-beta superfamily alter damage induced by various neuronal injuries. Of these proteins, glial cell line-derived neurotrophic factor (GDNF) and bone morphogenetic protein-7 (BMP-7) have unique protective and regenerative effects in stroke animals. Delivery of GDNF or BMP-7 to brain tissue reduced cerebral infarction and improved motor functions in stroke animals. Pretreatment with these factors reduced caspase-3 activity and DNA fragmentation in the ischemic brain region, suggesting that antiapoptotic effects are involved. Beside the protective effects, BMP-7 given after stroke improves locomotor function. These regenerative effects of BMP-7 may involve the enhancement of dendritic growth and remodeling. In this review, we illustrate the neuroprotective and neuroregenerative properties of GDNF and BMP-7 and emphasize their therapeutic potential for stroke.

Topics: Animals; Bone Morphogenetic Protein 7; Bone Morphogenetic Proteins; Brain Ischemia; Cell Transplantation; Clinical Trials as Topic; Genetic Therapy; Glial Cell Line-Derived Neurotrophic Factor; Humans; Nerve Growth Factors; Neuroprotective Agents; Parkinson Disease; Stroke; Transforming Growth Factor beta

We developed human mesenchymal stem cell (MSC) lines that could differentiate into various tissue cells including bone, neural cells, bone marrow (BM) stromal cells supporting the growth of hematopoietic stem cell (HSC), and so-called 'tumor stromal cells' mixing with tumor cells. We investigated the applicability of MSC as therapeutic cell transplanting reagents (cytoreagents). Telomerized human BM derived stromal cells exhibited a prolonged lifespan and supported the growth of hematopoietic clonogenic cells. The gene transfer of Indian hedgehog (Ihh) remarkably enhanced the HSC expansion supported by the human BM stromal cells. Gene-modified MSC are useful as therapeutic tools for brain tissue damage (e.g. brain infarction) and malignant brain neoplasms. MSC transplantation protected the brain tissue from acute ischemic damage in the midcerebral artery occlusion (MCAO) animal model. Brain-derived neurotrophic factor (BDNF)-gene transduction further enhanced the protective efficacy against the ischemic damage. MSC possessed excellent migratory ability and exerted inhibitory effects on the proliferation of glioma cells. Gene-modification of MSC with therapeutic cytokines clearly augmented the antitumor effect and prolonged the survival of tumor-bearing animals. Gene therapy employing MSC as a tissue-protecting and targeting cytoreagent would be a promising approach.

Topics: Animals; Bone Morphogenetic Protein 2; Bone Morphogenetic Proteins; Brain Ischemia; Brain Neoplasms; Cell Differentiation; Cell Survival; Disease Models, Animal; DNA-Binding Proteins; Gene Transfer Techniques; Genetic Therapy; Glioma; Hedgehog Proteins; Hematopoietic Stem Cells; Humans; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Telomerase; Trans-Activators; Transforming Growth Factor beta

This review discusses the potential usefulness of several selected polypeptide growth factors as treatments for stroke. Distinctions between global vs. focal cerebral ischemia, permanent vs. temporary focal ischemia, and acute stroke vs. stroke recovery are first discussed. Potential routes of administration of growth factors are also considered. The growth factors basic fibroblast growth factor (bFGF), osteogenic protein-1 (OP-1), vascular endothelial growth factor (Veg-f), erythropoietin (EPO), and granulocyte colony stimulating factor (G-CSF) all show potential usefulness in animal models of acute stroke and stroke recovery. Two of these factors, bFGF and EPO, have reached human clinical trials for acute stroke, and the data are discussed. Future directions in this field are also discussed.

Topics: Animals; Bone Morphogenetic Protein 7; Bone Morphogenetic Proteins; Brain Ischemia; Drug Administration Routes; Erythropoietin; Fibroblast Growth Factor 2; Granulocyte Colony-Stimulating Factor; Growth Substances; Humans; Mice; Rats; Stroke; Transforming Growth Factor beta; Vascular Endothelial Growth Factors

Transforming growth factor-beta (TGF-beta) has diverse and multiple roles throughout the body. This review focuses on the evidence supporting its functions in the central nervous system, with a particular emphasis on its purported role in cerebral ischemia. Numerous studies have documented that TGF-beta1 levels are enhanced in the brain following cerebral ischemia. As evidence that such an upregulation is beneficial, agonist studies have demonstrated that TGF-beta1 reduces neuronal cell death and infarct size following middle cerebral artery occlusion (MCAO), while conversely, antagonist studies have shown increased neuronal cell death and infarct size after MCAO. These studies suggest that TGF-beta1 has a neuroprotective role in cerebral ischemia. Recent work with adenoviral- mediated overexpression of TGF-beta1 in vivo in mice has further implicated a neuroprotective role for TGF-beta1 in cerebral ischemia, as evidenced by a reduction in neuronal cell death, infarct size, and neurological outcome. Additionally, numerous in vitro studies have documented the neuroprotective ability of TGF-beta1 in neurons from a variety of species, including rats, mice, chicks, and humans. Of significant interest, TGF-beta1 was shown to be protective against a wide variety of death-inducing agents/insults, including hypoxia/ischemia, glutamate excitotoxicity, beta-amyloid, oxidative damage, and human immunodeficiency virus. The mechanism of TGF-beta1-mediated neuroprotection remains to be resolved, but early evidence suggests that TGF-beta1 regulates the expression and ratio of apoptotic (Bad) and antiapoptotic proteins (Bcl-2, Bcl-x1), creating an environment favorable for cell survival of death-inducing insults. Taken as a whole, these results suggest that TGF-beta1 is an important neuroprotective factor that can reduce damage from a widearray of death-inducing agents/insults in vitro, as well as exert protection of the brain during cerebral ischemia.

Topics: Animals; Apoptosis; Brain; Brain Ischemia; Central Nervous System; Humans; Mitogen-Activated Protein Kinases; Neurons; Neuroprotective Agents; Signal Transduction; Tissue Distribution; Transforming Growth Factor beta

Necrosis and apoptosis are the two fundamental hallmarks of neuronal death in stroke. Nevertheless, thrombolysis, by means of the recombinant serine protease t-PA, remains until now the only approved treatment of stroke in man. Over the last years, the cytokine termed Transforming Growth Factor-beta 1 (TGF-beta 1) has been found to be strongly up regulated in the central nervous system following ischemia-induced brain damage. Recent studies have shown a neuroprotective activity of TGF-beta 1 against ischemia-induced neuronal death. In vitro, TGF-beta 1 protects neurons against excitotoxicity by inhibiting the t-PA-potentiated NMDA-induced neuronal death through a mechanism involving the up-regulation of the type-1 plasminogen activator inhibitor (PAI-1) in astrocytes. Altogether, these observations suggest that either TGF-beta signaling or TGF-beta 1-modulated genes could be good targets for the development of new therapeutic strategies for stroke in man.

Topics: Animals; Astrocytes; Brain Ischemia; Cell Death; Gene Expression Regulation; Humans; Neuroprotective Agents; Plasminogen Activator Inhibitor 1; Transforming Growth Factor beta

1. Necrosis and apoptosis are the two fundamental hallmarks of neuronal death in stroke. Nevertheless, thrombolysis, by using the recombinant serine protease t-PA, remains until now the only approved treatment of stroke in man. 2. Over the last years, the cytokine termed Transforming Growth Factor-beta1 (TGF-beta1) has been found to be strongly up-regulated in the central nervous system following ischemia-induced brain damage. 3. Recent studies have shown a neuroprotective activity of TGF-beta1 against ischemia-induced neuronal death. In vitro, TGF-beta1 protects neurons against excitotoxicity by inhibiting the t-PA-potentiated NMDA-induced neuronal death through a mechanism involving the up-regulation of the type-1 plasminogen activator inhibitor (PAI-1) in astrocytes 4. In addition, TGF-beta1 has been recently characterized as an antiapoptotic factor in a model of staurosporine-induced neuronal death through a mechanism involving activation of the extracellular signal-regulated kinase 1/2 (Erk1/2) and a concomitant increase phosphorylation of the antiapoptotic protein Bad. 5. Altogether, these observations suggest that either TGF-beta signaling or TGF-beta1-modulated genes could be good targets for the development of new therapeutic strategies for stroke in man.

Topics: Animals; Apoptosis; bcl-Associated Death Protein; Brain Infarction; Brain Ischemia; Carrier Proteins; Humans; Mitogen-Activated Protein Kinases; Neuroprotective Agents; Plasminogen Activator Inhibitor 1; Transforming Growth Factor beta; Transforming Growth Factor beta1

Topics: Animals; Brain Ischemia; Fibroblast Growth Factor 2; Nerve Growth Factors; Transforming Growth Factor beta

Some degree of spontaneous recovery is usually observed after stroke. Experimental studies have provided information about molecular mechanisms underlying this recovery. However, the majority of pre-clinical stroke studies are performed in male rodents, and females are not well studied. This is a clear discrepancy when considering the clinical situation. Thus, it is important to include females in the evaluation of recovery mechanisms for future therapeutic strategies. This study aimed to evaluate spontaneous recovery and molecular mechanisms involved in the recovery phase two weeks after stroke in female rats.. Transient middle cerebral artery occlusion was induced in female Wistar rats using a filament model. Neurological functions were assessed up to day 14 after stroke. Protein expression of interleukin 10 (IL-10), transforming growth factor (TGF)-β, neuronal specific nuclei protein (NeuN), nestin, tyrosine-protein kinase receptor Tie-2, extracellular signal-regulated kinase (ERK) 1/2, and Akt were evaluated in the peri-infarct and ischemic core compared to contralateral side of the brain at day 14 by western blot. Expression of TGF-β in middle cerebral arteries was evaluated by immunohistochemistry.. Spontaneous recovery after stroke was observed from day 2 to day 14 and was accompanied by a significantly higher expression of nestin, p-Akt, p-ERK1/2 and TGF-β in ischemic regions compared to contralateral side at day 14. In addition, a significantly higher expression of TGF-β was observed in occluded versus non-occluded middle cerebral arteries. The expression of Tie-2 and IL-10 did not differ between the ischemic and contralateral sides.. Spontaneous recovery after ischemic stroke in female rats was coincided by a difference observed in the expression of molecular markers. The alteration of these markers might be of importance to address future therapeutic strategies.

Topics: Animals; Brain Ischemia; Female; Infarction, Middle Cerebral Artery; Interleukin-10; Ischemic Stroke; Male; Nestin; Pregnancy; Proto-Oncogene Proteins c-akt; Rats; Rats, Wistar; Recovery of Function; Stroke; Transforming Growth Factor beta

Cell therapies that invoke pleiotropic mechanisms may facilitate functional recovery in patients with stroke. Based on previous experiments using microglia preconditioned by oxygen-glucose deprivation, we hypothesized that the administration of peripheral blood mononuclear cells (PBMCs) preconditioned by oxygen-glucose deprivation (OGD-PBMCs) to be a therapeutic strategy for ischemic stroke. Here, OGD-PBMCs were identified to secrete remodelling factors, including the vascular endothelial growth factor and transforming growth factor-β in vitro, while intra-arterial administration of OGD-PBMCs at 7 days after focal cerebral ischemia prompted expression of such factors in the brain parenchyma at 28 days following focal cerebral ischemia in vivo. Furthermore, administration of OGD-PBMCs induced an increasing number of stage-specific embryonic antigen-3-positive cells both in vitro and in vivo. Finally, it was found to prompt angiogenesis and axonal outgrowth, and functional recovery after cerebral ischemia. In conclusion, the administration of OGD-PBMCs might be a novel therapeutic strategy against ischemic stroke.

Topics: Animals; Brain; Brain Ischemia; Cells, Cultured; Disease Models, Animal; Glucose; Humans; Leukocytes, Mononuclear; Mice; Oxygen; Primary Cell Culture; Rats; Transforming Growth Factor beta; Treatment Outcome; Vascular Endothelial Growth Factor A

Stroke survivors often experience social isolation, which can lead to post‑stroke depression (PSD) and post‑stroke anxiety (PSA) that can compromise neurogenesis and impede functional recovery following the stroke. The present study aimed to investigate the effects and mechanisms of post‑stroke social isolation‑mediated PSD and PSA on hippocampal neurogenesis and cognitive function. The effects of the natural antidepressant hyperforin on post‑stroke social isolation‑mediated PSD and PSA were also investigated. In the present study, a model of PSD and PSA using C57BL/6J male mice was successfully established using middle cerebral artery occlusion combined with post‑stroke isolated housing conditions. It was observed that PSD and PSA were more prominent in the isolated mice compared with the pair‑housed mice at 14 days post‑ischemia (dpi). Mice isolated 3 dpi exhibited decreased transforming growth factor‑β (TGF‑β) levels and impairment of hippocampal neurogenesis and memory function at 14 dpi. Intracerebroventricular administration of recombinant TGF‑β for 7 consecutive days, starting at 7 dpi, restored the reduced hippocampal neurogenesis and memory function induced by social isolation. Furthermore, intranasal administration of hyperforin for 7 consecutive days starting at 7 dpi improved PSD and PSA and promoted hippocampal neurogenesis and memory function in the isolated mice at 14 dpi. The inhibition of TGF‑β with a neutralizing antibody prevented the effects of hyperforin. In conclusion, the results revealed a previously uncharacterized role of hyperforin in improving post‑stroke social isolation‑induced exaggeration of PSD and PSA and, in turn, promoting hippocampal neurogenesis and cognitive function via TGF‑β.

Topics: Animals; Anxiety; Behavior, Animal; Brain Ischemia; Depression; Hippocampus; Male; Mice, Inbred C57BL; Neurogenesis; Phloroglucinol; Recombinant Proteins; Recovery of Function; Social Isolation; Stroke; Terpenes; Transforming Growth Factor beta

Leucine-rich α2-glycoprotein1 (LRG1), a pleiotropic protein, plays a pathogenic role in multiple human diseases. However, its pathophysiological function in ischemia/reperfusion injury remains unclear. In this study, we discussed the function and mechanism of LRG1 in acute ischemic stroke from both basic and clinical research points of view. Mice underwent transient middle cerebral artery occlusion (tMCAO) surgery 2 weeks after LRG1 was overexpressed by the delivery of adeno-associated virus (AAV). For wild-type mice, both the protein and the transcript of LRG1 in the brain tissue were elevated after tMCAO. Meanwhile, the serum levels of LRG1 were decreased after tMCAO. The neuronal injury was shown aggravated in the AAV-LRG1 group (AAV-LRG1 mice with tMCAO) through infarction volume, neurological score, HE, and Nissl staining. Meanwhile, LRG1 significantly enhanced apoptosis and autophagy during tMCAO, as detected by caspase3, Bax, Bcl-2, LC3II/LC3I, Beclin1, p62, and a TUNEL assay. Furthermore, by overexpression of LRG1, the protein of ALK1 was upregulated and the TGFβ-smad1/5 signaling pathway was activated upon tMCAO. We also showed that patients with acute cerebral infarction had lower serum levels of LRG1 compared to healthy controls. In addition, LRG1 levels were associated with infarction volume, stroke severity, and prognosis in patients with supratentorial infarction. Taken together, the data from this study revealed that LRG1 promoted apoptosis and autophagy through the TGFβ-smad1/5 signaling pathway by up-regulating ALK1, which exacerbates ischemia/reperfusion injury.

Topics: Animals; Apoptosis; Autophagy; Biomarkers; Brain; Brain Ischemia; Disease Models, Animal; Female; Glycoproteins; Humans; Male; Mice, Inbred C57BL; Middle Aged; Neurons; Reperfusion Injury; Signal Transduction; Smad1 Protein; Smad5 Protein; Transforming Growth Factor beta

Ischemic stroke is still one of the leading debilitating diseases with high morbidity and mortality. NADPH oxidase (NOX)-derived reactive oxygen species (ROS) play an important role in cerebral ischemia/reperfusion (I/R) injury. However, the mechanism underlying the regulation of ROS generation is still not fully elucidated. This study aims to explore the role of transforming growth beta (TGF-β) signals in ROS generation.. Sprague-Dawley rats were subjected to I/R injury, and PC-12 cells were challenged by hypoxia/reoxygenation (H/R) and/or treated with activin receptor-like kinase (ALK5) inhibitor Sb505124 or siRNA against ALK5. Brain damage was evaluated using neurological scoring, triphenyl tetrazolium chloride staining, hematoxylin and eosin staining, infarct volume measurement, TUNEL staining, and caspase-3 activity measurement. Expression of TGF-β and oxidative stress-related genes was analyzed by real-time polymerase chain reaction and Western blot; NOX activity and ROS level were measured using spectrophotometry and fluorescence microscopy, respectively.. I/R contributed to severe brain damage (impaired neurological function, brain infarction, tissue edema, apoptosis), TGF-β signaling activation (upregulation of ALK5, phosphorylation of SMAD2/3) and oxidative stress (upregulation of NOX2/4, rapid release of ROS [oxidative burst]). However, Sb505124 significantly reversed these alterations and protected rats against I/R injury. As in the animal results, H/R also contributed to TGF-β signaling activation and oxidative stress. Likewise, the inhibition of ALK5 or ALK5 knockdown significantly reversed these alterations in PC-12 cells. Other than ALK5 knockdown, ALK5 inhibition had no effect on the expression of ALK5 in PC-12 cells.. Our studies demonstrated that TGF-β signaling activation is involved in the regulation of NOX2/NOX4 expression and exacerbates cerebral I/R injury.

Topics: Animals; Benzodioxoles; Brain Ischemia; Imidazoles; Male; NADPH Oxidase 2; NADPH Oxidase 4; Oxidative Stress; PC12 Cells; Pyridines; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Signal Transduction; Transforming Growth Factor beta; Up-Regulation

There is inflammation at the site of pathology in acute ischaemic stroke. In humans there is also elevation of levels of circulating cytokines in the days after stroke. We have previously found increased level of circulating T cells for up to three weeks after stroke. We have now measured cytokine levels for up to three weeks after stroke, looking for evidence of ongoing immune changes after the acute injury. Blood was collected from healthy controls and from subjects with acute ischaemic stroke on day 1, week 1 and week 3 after onset. Levels of interleukin 6 (IL6), interleukin 10 (IL10) and transforming growth factor beta (TGF-β) were measured by ELISA. We compared the cytokine levels in males and females, and correlated levels with stroke type as classified by the Oxfordshire stroke classification and stroke severity assessed by the NIH Stroke Scale. In the total group, levels TGF-β were significantly elevated at day 1. In the total group, levels of IL-6 were significantly elevated at all time-points. Levels of IL-10 were significantly elevated at week 1. The finding of elevated cytokine levels gives further evidence of ongoing immune activation for up to 3 weeks after acute ischaemic stroke. There was only a modest effect of stroke severity on levels of IL-6. There was also variability among individuals.

Topics: Brain Ischemia; Cytokines; Female; Humans; Individuality; Inflammation Mediators; Interleukin-10; Interleukin-6; Male; Severity of Illness Index; Time Factors; Transforming Growth Factor beta; Up-Regulation

GDF-15 is a novel distant member of the TGF-β superfamily and is widely distributed in the brain and peripheral nervous system. We have previously reported that GDF-15 is a potent neurotrophic factor for lesioned dopaminergic neurons in the substantia nigra, and that GDF-15-deficient mice show progressive postnatal losses of motor and sensory neurons. We have now investigated the regulation of GDF-15 mRNA and immunoreactivity in the murine hippocampal formation and selected cortical areas following an ischemic lesion by occlusion of the middle cerebral artery (MCAO). MCAO prominently upregulates GDF-15 mRNA in the hippocampus and parietal cortex at 3 h and 24 h after lesion. GDF-15 immunoreactivity, which is hardly detectable in the unlesioned brain, is drastically upregulated in neurons identified by double-staining with NeuN. NeuN staining reveals that most, if not all, neurons in the granular layer of the dentate gyrus and pyramidal layers of the cornu ammonis become GDF-15-immunoreactive. Moderate induction of GDF-15 immunoreactivity has been observed in a small number of microglial cells identified by labeling with tomato lectin, whereas astroglial cells remain GDF-15-negative after MCAO. Comparative analysis of the size of the infarcted area after MCAO in GDF-15 wild-type and knockout mice has failed to reveal significant differences. Together, our data substantiate the notion that GDF-15 is prominently upregulated in the lesioned brain and might be involved in orchestrating post-lesional responses other than the trophic support of neurons.

Topics: Animals; Brain Ischemia; Cells, Cultured; Cerebral Cortex; Cerebral Infarction; Gene Expression Regulation; Growth Differentiation Factor 15; Male; Mice; Mice, Inbred C57BL; Middle Cerebral Artery; Models, Animal; Neurons; RNA, Messenger; Transforming Growth Factor beta; Up-Regulation

Previous studies have indicated that methamphetamine (MA) potentiates neurodegeneration induced by ischemia in brain. We, and others, have reported that bone morphogenetic protein 7 (BMP7) is protective against MA and ischemic brain injury. The purpose of this study is to examine whether BMP7 reduces synergistic injury induced by both MA and cerebral ischemia. Adult CD-1 mice were treated with MA (4x 10mg/kg, each dose 2h apart) or saline. Using the quantitative real time polymerase chain reaction, we found that MA suppressed the expression of BMP7 mRNA in the cerebral cortex 1 day after injection. Ischemic and reperfusional injuries were introduced by ligation of the right middle cerebral artery for 90min after MA injection. Animals were sacrificed for caspase-3/7 activity assay and tri-phenyl-tetrazolium chloride staining at 1h and 2 days after reperfusion, respectively. Cerebral infarction and caspase-3/7 activity were enhanced in the stroke animals pretreated with MA; both responses were attenuated by pretreatment with BMP7. In conclusion, our data suggest that MA facilitates cerebral infarction after ischemia possibly mediated, in part, through the suppression of BMP7.

Topics: Animals; Bone Morphogenetic Protein 7; Bone Morphogenetic Proteins; Brain Ischemia; Caspase 3; Caspase 7; Dopamine Agents; Gene Expression; Injections, Intraventricular; Male; Methamphetamine; Mice; Reverse Transcriptase Polymerase Chain Reaction; Transforming Growth Factor beta

Recent studies have shown that administration of granulocyte colony-stimulating factor (G-CSF) is neuroprotective. However, the precise mechanisms of the neuroprotective effect of G-CSF are not entirely known. We carried out 90-min transient middle cerebral occlusion (tMCAO) of rats. The rats were injected with vehicle or G-CSF (50 mug/kg) immediately after reperfusion and sacrificed 8, 24, or 72 hr later. 2,3,5-Triphenyltetrazolium chloride (TTC) staining was carried out using brain sections of 72 hr, and immunohistochemistry was carried out with those of 8, 24, and 72 hr. TTC-staining showed a significant reduction of infarct volume in the G-CSF-treated group (**P < 0.01). Immunohistochemistry showed a significant decrease of the number of cells expressing tumor necrosis factor-alpha (TNF-alpha) at 8-72 hr, transforming growth factor-beta (TGF-beta) and inducible nitric oxide synthase (iNOS) at 24 and 72 hr after tMCAO in the peri-ischemic area (*P < 0.05 each). Our data suggest that the suppression of inflammatory cytokines and iNOS expression may be one mechanism of neuroprotection by G-CSF.

Topics: Animals; Anti-Inflammatory Agents; Brain; Brain Ischemia; Granulocyte Colony-Stimulating Factor; Immunohistochemistry; Infarction, Middle Cerebral Artery; Inflammation; Male; Nervous System; Neuroprotective Agents; Nitric Oxide Synthase Type II; Rats; Rats, Wistar; Stroke; Time Factors; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Ischemic tolerance is a phenomenon whereby a sublethal ischemic insult [ischemic preconditioning (IPC)] provides robust protection against subsequent lethal ischemia. Activation of N-methyl-D-aspartate (NMDA) receptors and subsequent new gene transcription are required for tolerance. We utilized the NMDA antagonist, MK801, prior to the IPC stimulus to separate candidate genes from epiphenomenona. Rats were divided into four groups: vehicle/IPC (preconditioned), MK801/IPC (attenuated preconditioning), vehicle/sham (non-preconditioned), and MK801/sham (non-preconditioned). Hippocampi (5/group/time point) were harvested immediately after ischemia as well as 1, 4, and 24 h post-ischemia to profile gene expression patterns using microarray analyses. Extracted mRNAs were pooled and subsequently hybridized to Affymetrix arrays. In addition, groups of rats were sacrificed for Western blot analysis and histological studies. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and gene ontology (GO) analyses were used to identify functionally related groups of genes whose modulation was statistically significant, while hierarchical cluster analysis was used to visualize the fold expression within these groups. Significantly modulated pathways included: MAP kinase signaling pathway, Toll receptor pathway, TGF-beta signaling pathways, and pathways associated with ribosome function and oxidative phosphorylation. Our data suggest that the tolerant brain responds to subsequent ischemic stress by partially downregulating inflammatory and upregulating protein synthesis and energy metabolism pathways.

Topics: Animals; Blotting, Western; Bone Morphogenetic Protein 7; Bone Morphogenetic Proteins; Brain Ischemia; Cluster Analysis; Computational Biology; Cyclooxygenase 2; Databases, Genetic; Fluorescent Antibody Technique, Direct; Gene Expression; Hippocampus; Ischemic Preconditioning; Male; Mitogen-Activated Protein Kinase Kinases; Oligonucleotide Array Sequence Analysis; Rats; Rats, Wistar; Reverse Transcriptase Polymerase Chain Reaction; Ribosomes; Signal Transduction; Toll-Like Receptors; Transforming Growth Factor beta

Bone morphogenetic proteins (BMPs) affect cell proliferation and differentiation. Astrocytes in ischemic brain are highly responsive to bone marrow stromal cell (BMSC) treatment. We investigated the effects of BMSCs on astrocytes cultured under oxygen- and glucose-deprived conditions, which in part simulate in vivo stroke conditions, to test the hypothesis that BMSCs alter astrocytic expression of BMPs which may contribute to neurological functional recovery of stroke. Quantitative real-time RT-PCR showed that the expression of BMP2/4 mRNAs decreased within ischemic astrocytes, In contrast, BMP2/4 mRNA was significantly increased after cocultured with BMSCs. Western blotting also confirmed this increase at the protein level in the medium of ischemic astrocytes after coculture with BMSCs. As a source of neural stem and progenitor cells, cultured subventricular zone (SVZ) neurospheres exposed to medium obtained from ischemic astrocytes cocultured with BMSCs were significantly enriched in cells expressing the astrocytic marker glial fibrillary acidic protein (GFAP), but not at the expense of beta-III-tubulin-positive SVZ neuroblasts. The expression of BMP2/4 subsequently increased the phosphorylation of downstream effector Smad1 and the expression of notch signal pathway-induced protein Hes1 in cultured SVZ neurospheres. BMP antagonist Noggin blocked the elevation of phosphorylated Smad1 and the expression of Hes1 as well as reducing the percentage of astrocytic SVZ progenitor cells. Our results indicate that BMSCs increase BMP2/4 expression in ischemic astrocytes. These changes enhance subventricular progenitor cell gliogenesis by activating relevant signaling pathways. BMSC-stimulated signaling of endogenous astrocytes may alter the ischemic environment, promoting remodeling of brain and hence, improve functional recovery after stroke.

Topics: Animals; Astrocytes; Basic Helix-Loop-Helix Transcription Factors; Bone Marrow Cells; Bone Morphogenetic Protein 2; Bone Morphogenetic Protein 4; Bone Morphogenetic Proteins; Brain; Brain Ischemia; Cell Communication; Cell Differentiation; Cell Line; Cells, Cultured; Cerebral Infarction; Culture Media, Conditioned; Glial Fibrillary Acidic Protein; Glucose; Homeodomain Proteins; Nerve Regeneration; Oxygen; Phenotype; Rats; Rats, Wistar; RNA, Messenger; Smad1 Protein; Stem Cells; Stromal Cells; Transcription Factor HES-1; Transforming Growth Factor beta

Transforming growth factor-beta1 (TGF-beta1) is an anti-inflammatory cytokine that plays an important role in cerebrovascular pathophysiology with protective activity against ischemia-induced neuronal death. We investigated the association of the polymorphism in TGFB1 with ischemic stroke and vascular dementia.. Three sequence variants in and around promoter and exons of TGFB1 gene were identified in 30 Koreans. Pro10Leu was selected for association study, and then control subjects (n=207) and patients with ischemic stroke (n=271) and vascular dementia (n=207) were screened.. Subjects carrying Leu/Leu were susceptible to both ischemic stroke (odds ratio [OR]=1.63; P<0.05) and vascular dementia (OR=1.88; P<0.01). Analyses with stroke subtypes showed a strong association with small vessel occlusion (SVO, n=110; OR=2.07; P<0.01). Further analysis of SVO data partitioned by gender revealed the female-specific association with Pro10Leu (OR=2.70; P<0.05).. The Pro10Leu of TGFB1 might be a risk factor of ischemic stroke and vascular dementia, especially for SVO in females.

Topics: Aged; Aged, 80 and over; Alleles; Brain Ischemia; Dementia, Vascular; Female; Genetic Linkage; Genetic Variation; Humans; Korea; Male; Middle Aged; Polymorphism, Genetic; Risk Factors; Sex Factors; Stroke; Transforming Growth Factor beta; Transforming Growth Factor beta1

Microglia-derived protection of brain cells (microglia, astrocytes, and neurons) during in vitro ischemic stress (deprivation of glucose, oxygen, and serum) was determined. Trypan blue exclusion assay, immunoblocking assay, Western blot analysis, and ELISA assay were used to determine the molecular mechanisms responsible for the microglia-derived protection. Results demonstrated that supernatants from the ischemic microglia protected all three cell-types from ischemia-induced damage by releasing the transforming growth factor-beta1 (TGF-beta1) and glial cell line-derived neurotrophic factor (GDNF). The protection of microglia was TGF-beta1 related, whereas astrocytes protection was GDNF-dependent. The protection of neurons was TGF-beta1 and GDNF independent, and the molecular nature responsible for their protection remains to be determined. These results indicate contribution from the surrounding cells and the types of receptors expressed on different brain cells probably also play an important role in determining their fate against ischemia.

Topics: Animals; Astrocytes; Blotting, Western; Brain; Brain Ischemia; Cells, Cultured; Enzyme-Linked Immunosorbent Assay; Glial Cell Line-Derived Neurotrophic Factor; Microglia; Nerve Growth Factors; Neurons; Neuroprotective Agents; Rats; Rats, Sprague-Dawley; Transforming Growth Factor beta

The transcription factor NF-kappaB is a key regulator of inflammation and cell survival. NF-kappaB is activated by cerebral ischemia in neurons and glia, but its function is controversial. To inhibit NF-kappaB selectively in neurons and glial cells, we have generated transgenic mice that express the IkappaBalpha superrepressor (IkappaBalpha mutated at serine-32 and serine-36, IkappaBalpha-SR) under transcriptional control of the neuron-specific enolase (NSE) and the glial fibrillary acidic protein (GFAP) promoter, respectively. In primary cortical neurons of NSE-IkappaBalpha-SR mice, NF-kappaB activity was partially inhibited. To assess NF-kappaB activity in vivo after permanent middle cerebral artery occlusion (MCAO), we measured the expression of NF-kappaB target genes by real-time polymerase chain reaction (PCR). The induction of c-myc and transforming growth factor-beta2 by cerebral ischemia was inhibited by neuronal expression of IkappaBalpha-SR, whereas induction of GFAP by MCAO was reduced by astrocytic expression of IkappaBalpha-SR. Neuronal, but not astrocytic, expression of the NF-kappaB inhibitor reduced both infarct size and cell death 48 hours after permanent MCAO. In summary, the data show that NF-kappaB is activated in neurons and astrocytes during cerebral ischemia and that NF-kappaB activation in neurons contributes to the ischemic damage.

Topics: Amino Acid Substitution; Animals; Astrocytes; Brain Ischemia; Cell Death; Gene Expression Regulation; Glial Fibrillary Acidic Protein; I-kappa B Proteins; Infarction, Middle Cerebral Artery; Mice; Mice, Transgenic; Neurons; NF-kappa B; NF-KappaB Inhibitor alpha; Phosphopyruvate Hydratase; Point Mutation; Promoter Regions, Genetic; Proto-Oncogene Proteins c-myc; Transcription Factor RelA; Transforming Growth Factor beta

Gender differences in outcome following cerebral ischemia have frequently been observed and attributed to the actions of steroid hormones. Progesterone has been shown to possess neuroprotective properties following transient ischemia, with respect to decreasing lesion volume and improving functional recovery. The present study was designed to determine the mechanisms of progesterone neuroprotection, and whether these relate to the inflammatory response. Male mice underwent either 60 min or permanent middle cerebral artery occlusion (MCAO) and received progesterone (8 mg/kg ip) or vehicle 1 h, 6 h and 24 h post-MCAO. Forty-eight hours following transient MCAO, structural magnetic resonance imaging revealed a significant decrease in the amount of edematous tissue present in progesterone-treated mice as compared with vehicle. Using real-time PCR we found that progesterone treatment significantly suppressed the injury-induced upregulation of interleukin (IL)-1beta, transforming growth factor (TGF)beta2, and nitric oxide synthase (NOS)-2 mRNAs in the ipsilateral hemisphere while having no effect on tumor necrosis factor (TNF)-alpha mRNA expression. Progesterone treatment following permanent MCAO also resulted in a significant decrease in lesion volume. This was not apparent in mice lacking a functional NOS-2 gene. Thus, progesterone is neuroprotective in both permanent and transient ischemia, and this effect is related to the suppression of specific aspects of the inflammatory response.

Topics: Animals; Brain; Brain Ischemia; Disease Models, Animal; Infarction, Middle Cerebral Artery; Inflammation; Interleukin-1; Magnetic Resonance Imaging; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Progesterone; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tetrazolium Salts; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Cerebral ischemia rapidly initiates structural and functional changes in brain vessels, including blood-brain barrier disruption, inflammation, and angiogenesis. Molecular events that accompany these changes were investigated in brain microvessels extracted using laser-capture microdissection (LCM) from Sprague-Dawley rats subjected to a 20 min transient global cerebral ischemia followed by 1, 6, or 24 h reperfusion. Proteins extracted from approximately 300 LCM captured microvessels (20-100 microm) were ICAT-labeled and analyzed by nanoLC-MS. In-house software was used to identify paired ICAT peaks, which were then sequenced by nanoLC-MS/MS. Pattern analyses using k-means clustering method classified 57 differentially expressed proteins in 7 distinct dynamic patterns. Protein function was assigned using Panther Classification system. Early reperfusion (1 h) was characterized by down-regulation of ion pumps, nutrient transporters, and cell structure/motility proteins, and up-regulation of transcription factors, signal transduction molecules and proteins involved in carbohydrate metabolism. The up-regulation of inflammatory cytokines and proteins involved in the extracellular matrix remodeling and anti-oxidative defense was observed in late reperfusion (6-24 h). The up-regulation of IL-1beta and TGF-1beta in ischemic brain vessels was confirmed by ELISA, quantitative PCR, and/or immunohistochemistry. A biphasic postischemic (1 and 24 h) BBB opening for (3)H-sucrose was evident in the same model. Differentially expressed proteins identified in brain vessels during reperfusion are likely involved in orchestrating functional vascular responses to ischemia, including the observed BBB disruption.

Topics: Animals; Antioxidants; Blood Vessels; Blood-Brain Barrier; Brain; Brain Ischemia; Carbohydrates; Chromatography, Liquid; Cytokines; Enzyme-Linked Immunosorbent Assay; Extracellular Matrix; Female; Immunohistochemistry; Inflammation; Interleukin-1; Ischemic Attack, Transient; Lasers; Male; Mass Spectrometry; Microcirculation; Microdissection; Microscopy, Fluorescence; Peptides; Permeability; Polymerase Chain Reaction; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Sucrose; Time Factors; Transforming Growth Factor beta; Up-Regulation

To assess emodin antagonism to cerebral ischemia injury, and to discuss the mechanism of emodin inhibiting the inflammatory cascade reaction from the levels and expressions of cytokines.. Rats were divided into sham-operated group, model group, Ligustrazine group and emodin groups (low, middle, high dosage). After focal cerebral ischemic model of cerebral middle artery occlusion was duplicated with nylon thread, we took the speciments after ischemia 6 hours, observed the changes of the evaluating score of neural symptoms, brain water ratio and cerebral infarction area, determined the levels of TNF-alpha, IL-beta and TGF-beta in rats brain tissue by radioimmunoassay, detected the expressions of TNF-alpha and VCAM-1 by immunohistochemistry, and measured VCAM-1-mRNA expression by in-situ hybridization.. Compared with sham-operated group, the evaluating score of neural symptoms, brain water ratio and cerebral infarction area of rats in model group were higher (P < 0.01) , the levels of TNF-alpha and IL-1beta of rats brain tissue in model group increased, while the level of TGF-beta was lower, and the expressions of TNF-alpha and VCAM-1 increased (P < 0.01). The evaluating score of neural symptoms, brain water ratio and cerebral infarction area improved obviously in every emodin group, especially in emodin low dosage group. Levels of TNF-alpha, IL-1beta and the expressions of TNF-alpha and ICAM-1 in emodin low dosage group and Ligustrazine group were lower, while the level of TGF-beta was higher. Compared with Ligustrazine group, the changes aboved are more significant in emodin low dosage group (P < 0.01).. The increase of inflammatory cascade reaction mediated by various cytokines such as TNF, IL-1beta, ICAM-1 and the decrease of TGF protection are the important mechanism of cerebral ischemia injury. The mechanism of emodin antagonism to cerebral ischemia injury may be implemented by inhibiting inflammatory cascade reaction and increasing the brain protective factors, such as TGF.

Topics: Animals; Brain; Brain Ischemia; Dose-Response Relationship, Drug; Emodin; Female; Interleukin-1beta; Male; Neuroprotective Agents; Random Allocation; Rats; Rats, Sprague-Dawley; RNA, Messenger; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha; Vascular Cell Adhesion Molecule-1

Ischemic preconditioning is a phenomenon that describes how a sublethal ischemic insult can induce tolerance to subsequent ischemia. This phenomenon has been observed after focal or global ischemia in different animal models. However, the hypothesis that bacterial infection might lead to neuronal tolerance to injury has not been investigated. To mimic cerebral bacterial infection, we injected bacterial lipopolysaccharide (LPS) in the right dorsal hippocampus, followed 24 hours later by an excitotoxic lesion using kainic acid in the mouse model. Quantification of lesion size after cresyl violet counterstaining revealed that LPS pretreatment afforded neuroprotection to CA3 neurons against KA challenge. To investigate the events underlying this protection, we studied the cytokine profile induced after LPS injection. Interleukin (IL)-1 beta and transforming growth factor beta 1 (TGF-beta 1) were the main cytokines expressed at 24 hours after LPS injection. Because IL-1 beta has been described as deleterious in acute injury, we decided to investigate the function of TGF-beta 1. An adenovirus expressing a constitutively active form of TGF-beta 1 was injected intracerebrally 1 week before the induction of excitotoxic lesion, and neuronal protection was observed. To confirm the neuroprotective role of TGF-beta 1, the TGF-beta 1 adenovirus was replaced by recombinant human TGF-beta 1 protein and total neuroprotection was observed. Furthermore, the antibody-mediated blocking of TGF-beta 1 action prevented the protective effect of pretreatment with LPS. We have demonstrated in vivo that the cerebral tolerance phenomenon induced by LPS pretreatment is mediated by TGF-beta 1 cytokine.

Topics: Adenoviridae; Animals; Brain Ischemia; Cytokines; Excitatory Amino Acid Agonists; Female; Gene Expression; Gene Transfer Techniques; Ischemic Preconditioning; Kainic Acid; Lipopolysaccharides; Male; Mice; Mice, Inbred C57BL; Neuroprotective Agents; Neurotoxins; Transforming Growth Factor beta; Transforming Growth Factor beta1

Topics: Blood Platelets; Brain Ischemia; Endothelial Growth Factors; Humans; Leukocyte Count; Lymphokines; Predictive Value of Tests; Research Design; Stroke; Stroke Volume; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors

Background and Purpose-Chemokines have been shown to play an important role in leukocyte and monocyte/macrophage infiltration into ischemic regions. The purpose of this study is to identify whether overexpression of the active human transforming growth factor-ss1 (ahTGF-ss1) can downregulate expression of monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-1alpha (MIP-1alpha), and intercellular adhesion molecule-1 (ICAM-1) and reduce ischemic brain injury.. -Overexpression of transforming growth factor-ss1 (TGF-ss1) was achieved through adenoviral gene transfer. Five days after adenoviral transduction, the mouse underwent 30 minutes of middle cerebral artery occlusion followed by 1 to 7 days of reperfusion. TGF-ss1, MCP-1, MIP-1alpha, and ICAM-1 were detected by enzyme-linked immunosorbent assay and immunohistochemistry. Infarct areas and volumes were measured by cresyl violet staining.. -MCP-1 and MIP-1alpha expression is increased after middle cerebral artery occlusion, and double-labeled immunostaining revealed that MCP-1 is colocalized with neurons and astrocytes. Viral-mediated TGF-ss1 overexpression was significantly greater at measured time points, with a peak at 7 to 9 days. The expression of MCP-1 and MIP-1alpha, but not ICAM-1, was reduced in the mice overexpressing ahTGF-ss1 (P:<0.05). Furthermore, infarct volume was significantly reduced in the mice overexpressing ahTGF-ss1 (P:<0.05).. -This study demonstrates that MCP-1 and MIP-1alpha expressed in the ischemic region may play an important role in attracting inflammatory cells. The reduction of MCP-1 and MIP-1alpha, but not ICAM-1, in the mice overexpressing ahTGF-ss1 suggests that the neuroprotective effect of TGF-ss1 may result from the inhibition of chemokines during cerebral ischemia and reperfusion.

Topics: Adenoviridae; Animals; Blood Flow Velocity; Brain; Brain Ischemia; Chemokine CCL2; Chemokine CCL3; Chemokine CCL4; Disease Models, Animal; Gene Transfer Techniques; Genetic Vectors; Humans; Immunohistochemistry; Infarction, Middle Cerebral Artery; Inflammation; Intercellular Adhesion Molecule-1; Macrophage Inflammatory Proteins; Mice; Reperfusion; Transforming Growth Factor beta; Transforming Growth Factor beta1

Several trophic factors are known to regulate the survival and growth of neurons in brain and peripheral tissues. Several findings suggest that basic fibroblast growth factor-2 (FGF-2) plays an important role in the "self-repair" responses that follow injuries such as trauma and brain ischemia and that FGF-2 contributes to the repair of damaged tissue. Transforming growth factor-beta (TGF-beta) is a potent growth-regulatory protein secreted by virtually all cells. In the present study, we used immunohistochemical techniques to investigate whether FGF-2 and TGF-beta1 participate in the healing of damaged tissue following partial brain ischemia. The profile of the observed immunoreactivities indicated that TGF-beta1 and FGF-2 release varies between the different cerebral areas subjected to ischemic insult. Moreover, the sectorial heterogeneity of immunocytochemical response suggests that, during postischemic reperfusion, neuronal recovery may be due not only to neuron-glia interaction but also to neurochemical conditions involving inhibitory interneurons.

Topics: Animals; Brain Ischemia; Cerebellar Cortex; Cerebral Cortex; Disease Models, Animal; Fibroblast Growth Factor 2; Hippocampus; Male; Nerve Regeneration; Neurons; Rats; Rats, Wistar; Recovery of Function; Reperfusion Injury; Time Factors; Transforming Growth Factor beta

We have examined the distribution of transforming growth factor-beta1 (TGF-beta1) and bone morphogenetic protein-6 (BMP-6) in the brain of rats subjected to a mild and reversible ischemic damage produced by a 20-min occlusion of both carotid arteries without occlusion of the vertebral arteries. We have selected this model to study how the expression of trophic factor of the TGF-beta superfamily changes in neurons that recover from a transient insult. Immunocytochemical analysis showed a loss of TGF-beta1 in neurons of all hippocampal subfields immediately after the ischemic period, followed by a recovery of immunoreactivity in CA1 and CA3 neurons after reperfusion. BMP-6 immunoreactivity was also lost in most hippocampal neurons, but immunostaining became particularly intense in the interstitial space after both ischemia and reperfusion. An interstitial localization of BMP-6 was also observed in the cerebral cortex, particularly after reperfusion. Mild ischemia also induced substantial changes in the expression of TGF-beta1 and BMP-6 within the cerebellar cortex. In control animals, these factors appeared to be localized in granule cells (TGF-beta1) and Purkinje cells (both), whereas the molecular layer was not immunopositive. Both TGF-beta1 and BMP-6 were highly expressed in the interstitial spaces of the cerebellar cortex either 20 min after ischemia or 20 min after reperfusion. Taken collectively, these results suggest that a mild and reversible ischemia stimulates the release of BMP-6 from neurons into the interstitial space. We speculate that BMP-6, besides functioning during brain development, may also regulate neuronal resistance to insults of the adult brain.

Topics: Animals; Bone Morphogenetic Protein 6; Bone Morphogenetic Proteins; Brain Ischemia; Cerebellum; Cerebral Cortex; Hippocampus; Male; Neurons; Pyramidal Cells; Rats; Rats, Wistar; Reperfusion Injury; Transforming Growth Factor beta; Transforming Growth Factor beta1

Several kidney cell lines were investigated for their ability to produce glial cell line-derived neurotrophic factor (GDNF). Cell line-conditioned medium was analyzed using ELISA and two cell lines were identified which produce GDNF in physiologically active concentrations. ELISA analyses revealed that conditioned medium from these two cell lines also contained PDGF, bFGF, TGFbeta1 and TGFbeta2. Both of these cell lines were then transplanted into the striatal penumbra of rats, 1 h following middle cerebral artery occlusion. Behavioral testing revealed that both cell lines reduced the deficit associated with cerebral ischemia and reduced the infarct volume relative to controls. Reduction of infarct volume was likely achieved by the action of GDNF and/or other growth factors produced by the cells.

Topics: Animals; Behavior, Animal; Brain Ischemia; Cell Line; Cell Transplantation; Cerebral Infarction; Enzyme-Linked Immunosorbent Assay; Fetal Tissue Transplantation; Fetus; Fibroblast Growth Factor 2; Glial Cell Line-Derived Neurotrophic Factor; Humans; Kidney; Male; Nerve Growth Factors; Nerve Tissue Proteins; Platelet-Derived Growth Factor; Rats; Rats, Sprague-Dawley; Transforming Growth Factor beta

Bone morphogenetic protein-7 (BMP-7) has been shown to enhance dendritic growth and improve functional recovery after experimental stroke. In this study, we examined the effect of BMP-7 on functional recovery, local cerebral blood flow (LCBF) and local cerebral glucose utilization (LCMRglu) following transient middle cerebral artery occlusion. Sprague--Dawley rats (n=29) were anesthetized with halothane/nitrous oxide and received 2-h middle cerebral artery occlusion (MCAo) by poly-L-lysine-coated intraluminal suture. Rectal and cranial temperatures were regulated at 37.0--37.5 degrees C. BMP-7 or vehicle (volume, 25 microl) was administered intracisternally in a blinded fashion at 24 h after MCAo. Neurological status was evaluated during occlusion (60 min) and daily for 2 days after MCAo. In matched animal groups, LCMRglu was measured autoradiographically with [(14)C]2-deoxyglucose (2-DG) and LCBF with [(14)C]iodoantipyrine 48 h after MCAo. Four animals groups were studied: LCMRglu series (BMP-7, n=7; vehicle, n=8); LCBF series (BMP-7, n=6; vehicle, n=8). Average three-dimensional image data sets were constructed for each group and were compared by pixel-based statistical methods. Rectal and cranial temperatures, mean blood pressure, plasma glucose and blood gases were similar among groups. BMP-7 significantly improved the total neurological score compared to vehicle at 48 h after MCAo (7.3+/-0.4 vs. 9.0+/-0.2, respectively; P<0.0003). Compared to vehicle-rats, BMP-7 enhanced glucose utilization in the basal ganglia ipsilateral to stroke and improved LCBF in ipsilateral subthalamus, but decreased LCBF and LCMRglu in contralateral cortical regions.

Topics: Animals; Blood Pressure; Body Temperature; Bone Morphogenetic Protein 7; Bone Morphogenetic Proteins; Brain; Brain Ischemia; Cerebrovascular Circulation; Glucose; Infarction, Middle Cerebral Artery; Male; Movement Disorders; Neuroprotective Agents; Rats; Rats, Sprague-Dawley; Recovery of Function; Transforming Growth Factor beta

There has been an increasing interest in recent years in the evaluation of the neuronal and glial responses to ischemic insult. Some cytokines, including transforming growth factor-beta (TGF-beta), that are overexpressed after experimental stroke in rodents are thought to be implicated in the neuronal processes that lead to necrosis. Thus, such cytokines could predict tissue fate after stroke in humans, although data are currently sparse for gyrencephalic species. The current study addressed the expression pattern of TGF-beta1 in a nonhuman primate model of middle cerebral artery occlusion. Focal permanent ischemia was induced for 1 or 7 days in 6 baboons and the following investigations were undertaken: cerebral oxygen metabolism (CMRO2) positron emission tomography studies, magnetic resonance imaging, postmortem histology, and reverse transcription-polymerase chain reaction. The aim of the current study was to correlate the expression of TGF-beta1 to the underlying metabolic and histologic state of the threatened cerebral parenchyma. The authors evidenced increased TGF-beta1 mRNA levels (up to 25-fold) in those regions displaying a moderate (20% to 49%) reduction in CMRO2. The current findings suggest that the greatly enhanced expression of TGF-beta1 in the penumbral zones that surround tissue destined to infarction may represent a robust index of potentially salvageable brain. The current investigation, in the nonhuman primate, strengthens the authors' hypothesis, derived from rodent models, that TGF-beta1 may be involved in the physiopathology of human stroke.

Topics: Animals; Biomarkers; Brain; Brain Ischemia; Gene Expression; Magnetic Resonance Imaging; Male; Middle Cerebral Artery; Neurons; Oxygen Consumption; Papio; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tomography, Emission-Computed; Transforming Growth Factor beta

We have reviewed a battery of useful tests for evaluating sensorimotor function and plasticity acutely and chronically in unilateral rat models of central nervous system injury. These tests include forelimb use for weight shifting during vertical exploration in a cylindrical enclosure, an adhesive removal test of sensory function, and forelimb placing. These tests monitor recovery of sensorimotor function independent of the extent of test experience. Data are presented for four models, including permanent focal ischemia, focal injury to the forelimb area of sensorimotor cortex, dopaminergic neurodegeneration of the nigrostriatal system, and cervical spinal cord injury. The effect of the dendrite growth promoting factor, Osteogenic Protein-1 (OP-1) on outcome following permanent middle cerebral artery (MCA) occlusion was used as an example to illustrate how the tests can be applied preclinically. OP-1 showed a beneficial effect on limb use asymmetry in the cylinder test.

Topics: Animals; Behavior, Animal; Bone Morphogenetic Protein 7; Bone Morphogenetic Proteins; Brain Ischemia; Cerebral Decortication; Cervical Vertebrae; Dendrites; Disease Models, Animal; Evaluation Studies as Topic; Forelimb; Functional Laterality; Infarction, Middle Cerebral Artery; Male; Neck; Neuronal Plasticity; Neuropsychological Tests; Oxidopamine; Parkinsonian Disorders; Rats; Rats, Sprague-Dawley; Recovery of Function; Somatosensory Cortex; Spinal Cord Injuries; Stroke; Transforming Growth Factor beta

Both vascular endothelial growth factor (VEGF) and transforming growth factor-beta1 (TGF-beta1) are expressed in higher than normal concentrations in the penumbra of patients after ischemic stroke. Because both cytokines are central to the processes of angiogenesis, tissue inflammation, and fibrosis, we performed serial measurements of these cytokines in patients with cerebral infarction and determined their relationship to stroke etiology and volume.. We serially (at days 0, 1, 3, 7, and 14) measured the serum levels of VEGF and active TGF-beta1 in 29 patients with acute ischemic stroke. Age-matched healthy subjects (n=26) were used as controls.. Expression of VEGF was significantly increased in the majority of patients after acute stroke at each of the time points compared with normal controls. Highest expression occurred at day 7 (588+/-121 pg/mL; P=0.005), and it remained significantly elevated at 14 days after stroke. Expression of VEGF correlated with infarct volume, clinical disability (Scandinavian Stroke Scale), and peripheral leukocytosis and was significantly higher in patients with atherothrombotic large-vessel disease and ischemic heart disease (P<0.05 in all cases). In contrast, expression of active TGF-beta1 was not significantly different from control patients at any of the measured time points. When the mean concentration of TGF-beta1 from each patient (pooled time points) was compared with the control mean, a significant increase was found in only 2 patients, whereas levels decreased in 12 patients (P<0.05). There was no correlation between circulating active TGF-beta1 and VEGF expression, leukocytosis, stroke subtype, or patient disability as assessed by Scandinavian Stroke Scale score.. VEGF but not TGF-beta1 showed a dramatic increase in serum of stroke patients. Correlation between stroke severity and VEGF concentration suggests it could be involved in the subsequent repair processes resulting in partial recovery after stroke. Correlation between VEGF expression and peripheral leukocytosis suggests that these changes may also reflect the immunologic status of the patient. VEGF may play an important role in the pathophysiology of acute ischemic stroke and could be of value in future treatment strategies.

Topics: Acute Disease; Adult; Aged; Aged, 80 and over; Biomarkers; Brain Ischemia; Endothelial Growth Factors; Female; Humans; Leukocytosis; Lymphokines; Male; Middle Aged; Prognosis; Protein Isoforms; Severity of Illness Index; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors

The mechanisms underlying the neuroprotective effects of the group II metabotropic glutamate receptor (mGluR) agonist LY379268 were investigated in a gerbil model of global ischemia. LY379268 (10 mg/kg i.p.) 30 or 60 min after 5-min bilateral carotid artery occlusion (BCAO) attenuated the ischemia-induced hyperactivity and provided protection in the CA1 hippocampal cells. This neuroprotective effect was maintained (P <.001) when histological analysis was performed 14 and 28 days after BCAO. Furthermore, 24- or 48-h pretreatment with LY379268, 10 mg/kg i.p., before 5-min BCAO markedly reduced (P <.001 and P <.05, respectively) the damage to CA1 hippocampal neurons. This result is consistent with the induction of neuroprotective factors or a very long brain half-life. To study the possible induction of neuroprotective factors as contributing to this action of LY379268, brains were examined for expression of neurotrophic factors. Results indicated that LY379268 (10 mg/kg i.p.) failed to alter the expression of transforming growth factor-beta, brain-derived neurotrophic factor, nerve growth factor, and basic fibroblast growth factor in the hippocampal regions of brains taken from gerbils sacrificed at 6, 24, 72, and 120 h postinjection. The new group II mGlu antagonist, LY341495, administered 1 h before 5-min BCAO, attenuated the neuroprotective effect of LY379268 administered 24 h before 5-min BCAO. Complementary pharmacokinetic studies showed that a significant receptor-active concentration persisted in the brain 24 h after LY379268 10 mg/kg i.p. We conclude that group II mGluR occupancy, rather than induction of neuroprotective factors, explains the long-lasting neuroprotective effect of LY379268 in the gerbil model of global ischemia.

Topics: Amino Acids; Animals; Arterial Occlusive Diseases; Brain Ischemia; Brain-Derived Neurotrophic Factor; Bridged Bicyclo Compounds, Heterocyclic; Carotid Artery Diseases; Excitatory Amino Acid Agonists; Gerbillinae; Hippocampus; Immunohistochemistry; Male; Motor Activity; Nerve Growth Factor; Neurons; Neuroprotective Agents; Receptors, Metabotropic Glutamate; Transforming Growth Factor beta

Osteogenic protein-1 (OP1) not only possesses trophic activity on bone tissue but also influences neuronal survival and differentiation in vitro. Specific receptors for OP1 are present in brain and spinal cord and can be upregulated during cerebral contusion. OP1 is a member of the transforming growth factor-beta superfamily, several of whose members possess neuroprotective activity. In this study, the neuroprotective effect of OP1 in cerebral ischemia was evaluated in adult animals.. Adult male Sprague-Dawley rats were anesthetized with chloral hydrate. OP1 or vehicle was administered intracortically or intracerebroventricularly to the rats. Thirty minutes, 24 hours, or 72 hours after OP1 injection, the right middle cerebral artery (MCA) was ligated for 90 minutes. Twenty-four hours after reperfusion, animals were tested for motor behavior. The animals were subsequently anesthetized with urethane and perfused intracardially with saline. Brain tissue was removed, sliced, and incubated with 2% triphenyltetrazolium chloride to localize the area of infarction.. Only animals pretreated with OP1 24 hours before MCA ligation showed a reduction in motor impairment. OP1, given 30 minutes or 72 hours before MCA ligation, did not reduce cortical infarction. In contrast, pretreatment with OP1 24 hours before MCA ligation significantly attenuated the volume of infarction in the cortex, in agreement with the behavioral findings.. Intracerebral administration of OP1 24 hours before MCA ligation reduces ischemia-induced injury in the cerebral cortex.

Topics: Animals; Arterial Occlusive Diseases; Behavior, Animal; Bone Morphogenetic Protein 7; Bone Morphogenetic Proteins; Brain Ischemia; Cerebral Infarction; Ligation; Male; Neuroprotective Agents; Rats; Rats, Sprague-Dawley; Transforming Growth Factor beta

The tissue type plasminogen activator (t-PA) is a serine protease that is involved in neuronal plasticity and cell death induced by excitotoxins and ischemia in the brain. t-PA activity in the central nervous system is regulated through the activation of serine protease inhibitors (serpins) such as the plasminogen activator inhibitor (PAI-1), the protease nexin-1 (PN-1), and neuroserpin (NSP). Recently we demonstrated in vitro that PAI-1 produced by astrocytes mediates the neuroprotective effect of the transforming growth factor-beta1 (TGF-beta1) in NMDA-induced neuronal cell death. To investigate whether serpins may be involved in neuronal cell death after cerebral ischemia, we determined, by using semiquantitative RT-PCR and in situ hybridization, that focal cerebral ischemia in mice induced a dramatic overexpression of PAI-1 without any effect on PN-1, NSP, or t-PA. Then we showed that although the expression of PAI-1 is restricted to astrocytes, PN-1, NSP, and t-PA are expressed in both neurons and astrocytes. Moreover, by using semiquantitative RT-PCR and Western blotting, we observed that only the expression of PAI-1 was modulated by TGF-beta1 treatment via a TGF-beta-inducible element contained in the PAI-1 promoter (CAGA box). Finally, we compared the specificity of TGF-beta1 action with other members of the TGF-beta family by using luciferase reporter genes. These data show that TGF-beta and activin were able to induce the overexpression of PAI-1 in astrocytes, but that bone morphogenetic proteins, glial cell line-derived neutrophic factor, and neurturin did not. These results provide new insights into the regulation of the serpins/t-PA axis and the mechanism by which TGF-beta may be neuroprotective.

Topics: Amyloid beta-Protein Precursor; Animals; Astrocytes; Brain Ischemia; Carrier Proteins; Cell Death; Cells, Cultured; Gene Expression Regulation; Mice; Neurons; Neuropeptides; Neuroserpin; Plasminogen Activator Inhibitor 1; Protease Nexins; Receptors, Cell Surface; Serpins; Tissue Plasminogen Activator; Transforming Growth Factor beta

Increased levels of endothelin-1 (Et-1), a potent vasoconstrictor, have been correlated with hypertension and neuronal damage in ischemic/reperfusion injury. The presence of polymorphonuclear cells (PMNs) in the brain has been shown to be directly responsible for this observed pathology. To address the question of whether Et-1 plays a role in this process, human brain-derived endothelial cells (CNS-ECs) were cultured with Et-1. The results demonstrate that Et-1 induces production of the neutrophil chemoattractant interleukin-8 (IL-8) twofold to threefold after 72 hours; mRNA was maximal after 1 hour of stimulation. Conditioned culture medium derived from Et-1-stimulated CNS-ECs induced a chemotactic response in the PMN migration assay. The inflammatory cytokines tumor necrosis factor-alpha (TNF) and IL-1beta functioned additively with Et-1 in increasing IL-8 production. In contrast, transforming growth factor-beta (TGF-beta), but not IL-10, completely abolished the effect of Et-1 on IL-8 production. However, Et-1 did not modulate intercellular adhesion molecule-1 (ICAM-1) expression. These data demonstrate that Et-1 may be a risk factor in ischemic/reperfusion injury by inducing increased levels of the neutrophil chemoattractant IL-8.

Topics: Brain Ischemia; Cells, Cultured; Cerebral Arteries; Cerebral Veins; Chemotaxis, Leukocyte; Culture Media, Conditioned; Drug Synergism; Endothelin-1; Endothelium, Vascular; Gene Expression Regulation; Humans; Intercellular Adhesion Molecule-1; Interleukin-1; Interleukin-10; Interleukin-8; Protein Isoforms; Reperfusion Injury; Risk Factors; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

A residual blood supply to the ischaemic brain is a crucial determinant for tissue survival. Early changes in the vascular network and subsequent angiogenesis may be mediated by short-lived molecules like nitric oxide (NO) or growth factors such as transforming growth factor-beta1 (TGF-beta1). Although TGF-beta1 can inhibit NO production, this interaction has not been studied after ischaemia in humans. Serum samples were taken from patients at 24 h and 6 months and cerebrospinal fluid (CSF) samples at 24 h and 1 week later for possible correlation between the two factors. Tissue expression of TGF-beta1 and of the inducible isoform of NO synthase (NOS2) was assessed by immunohistochemistry. CSF levels of NO2-/NO3- as well as total (active + latent) TGF-beta1 were higher in stroke patients as compared to controls 24 h after the stroke. Both NO2-/NO3- and TGF-beta1 were lower 6 months after the stroke compared to 24 h. Levels of NO2-/NO3- correlated with levels of TGF-beta1 within the time points (P = 0.041, Kendall correlation coefficient). There was a strong staining for NOS2 in brain tissue sections in neurones, reactive astrocytes, infiltrating white blood cells, and endothelial cells of larger microvessels. TGF-beta1 expression was mainly limited to neurones and reactive astrocytes. These findings suggest that the interaction between TGF-beta1 and NOS2 might be important for angiogenesis after cerebral ischaemia and may indicate that TGF-beta1 is upregulated as a negative feedback response to elevated levels of NO.

Topics: Adult; Aged; Aged, 80 and over; Brain Ischemia; Female; Humans; Immunohistochemistry; Male; Middle Aged; Nitric Oxide; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Transforming Growth Factor beta

The effect of trophic factors on neuronal survival after 30 min oxygen and glucose deprivation (in vitro ischemia) was studied in primary hippocampal and cortical neuronal cultures of rat. In vitro ischemia was produced at 37 degrees C by placing cultures in glucose-free medium, the oxygen content of which was removed by gassing with pure argon. After in vitro ischemia neurons were allowed to recover either in serum-free minimal essential medium (MEM) or in MEM containing 5% native horse serum, 100 ng/ml basic fibroblast growth factor (bFGF) or 10 ng/ml transforming growth factor-beta 1 (TGF-beta 1), respectively. Cultures that recovered in serum-free medium suffered a progressive type of neuronal injury: survival of either cortical or hippocampal neurons declined from about 60% after 1 h to 50% after 3 h, 40% after 6 h and less than 20% after 24 h. Addition of serum proteins to the incubation medium did not influence early survival (up to 3-6 h) but significantly improved survival after 24 h (more than 40% in both hippocampal and cortical cultures). Addition of TGF-beta 1 and bFGF had only minor effects. These data show that serum reduces delayed ischemic cell death by a mechanism which is different from that of TGF-beta 1 or bFGF protection.

Topics: Animals; Antimetabolites; Argon; Brain Ischemia; Cell Death; Cells, Cultured; Cerebral Cortex; Culture Media, Serum-Free; Deoxyglucose; Fibroblast Growth Factor 2; Glucose; Hippocampus; Hypoxia; Neurons; Rats; Rats, Wistar; Transforming Growth Factor beta

Occlusion in cerebral vessels results in ischemic stroke and is followed by proliferation of microvessels, ie, angiogenesis. The process is particularly marked in the border zone of the infarct, known as the ischemic penumbra. This increase in vascularization is likely to be caused by the action of angiogenic factors, such as TGF-beta 1, which is a powerful regulator of angiogenesis.. In this study we examined 10 brain samples from patients who suffered from ischemic stroke for the expression of mRNA encoding TGF-beta 1.. The ischemic penumbra contained the highest levels of TGF-beta 1 mRNA, whereas the normal contralateral hemispheres had the least (P < .001, Mann-Whitney U test). Unlike those from normal brain, protein extracts from infarcted tissue contained active TGF-beta 1 as a 25-kD band in Western blot analysis. Extracts from the penumbra also contained a 12.5-kD isoform of TGF-beta 1. Both penumbra and infarct contained TGF-beta 1 immunoreactive products as assessed with immunohistochemistry, whereas very weak staining was observed in the contralateral hemisphere.. These results suggest that TGF-beta 1 is important in the pathogenesis of the angiogenic response in ischemic brain tissue and its modulation may be used for therapeutic purposes.

Topics: Aged; Aged, 80 and over; Astrocytes; Autopsy; Blotting, Western; Brain; Brain Ischemia; Cerebellum; Cerebral Infarction; DNA Probes; Endothelium, Vascular; Female; Functional Laterality; Gene Expression; Humans; In Situ Hybridization; Male; Middle Aged; Neurons; RNA, Messenger; Transforming Growth Factor beta

Possible neuroprotective actions of osteogenic protein-1 (OP-1) were evaluated in a rat model of cerebral hypoxia/ischemia. Intraperitoneal injection of 50 micrograms of OP-1 prior to bilateral carotid ligation and transient hypoxia in 12-day-old rats reduced cerebral infarct area from 44.8 +/- 3.3% in vehicle-injected controls to 29 +/- 4.9%. Treatment of 14-day-old rats with 20 micrograms of OP-1 1 h after hypoxia reduced mortality from 45% to 13%. OP-1 may represent a novel class of neuroprotective agents.

Topics: Animals; Bone Morphogenetic Protein 7; Bone Morphogenetic Proteins; Brain Ischemia; Disease Models, Animal; Hypoxia; Neutrophils; Proteins; Rats; Temperature; Transforming Growth Factor beta

Transient global cerebral ischemia induces selective neuronal degeneration in the adult rat hippocampus, which is both preceded and accompanied by activation of microglia and astrocytes. Altered expression patterns of cytokines and growth factors might influence the postischemic neuron-glial interactions as well as the degenerative neuronal processes. Northern blotting of hippocampal tissue from ischemic animals revealed elevated levels of transforming growth factor beta-1 (TGF-beta 1) mRNA, and in the present in situ hybridization study we examine the endogenous expression and cellular localization of TGF-beta 1 mRNA in the adult rat hippocampus at various intervals following 10 min of global cerebral ischemia. Six hours after ischemia, a diffuse expression of TGF-beta 1 mRNA was found throughout the brain, which further intensified until Day 2 and thereafter subsided. In parallel, a massive increase of signal was observed in the hilus fascia dentata from Day 1 and in area CA1 from Day 2 to 4, both areas displaying selective neuronal degeneration. Peak levels of TGF-beta 1 mRNA were found in the hilus around Day 4, whereas expression in the CA1 area persisted through Day 21, the latest time point examined. A similar biphasic response, consisting of a transient, generalized reaction and a persistent lesion-associated activation in areas undergoing selective neuronal degeneration, was previously described for microglia and is reconfirmed in the present study. Cells of the microglial/macrophage lineage thus include the potent modulatory cytokine TGF-beta 1 in their potential repertoire of responses to both CNS activation and lesioning.

Topics: Animals; Brain Ischemia; Hippocampus; Macrophages; Male; Microglia; Rats; Rats, Wistar; RNA, Messenger; Transforming Growth Factor beta

Transforming growth factor-beta 1 (TGF-beta 1), suggested in some studies to suppress astrocyte and neutrophil function, has also reduced ischaemic brain injury when administered immediately prior to clot embolization in models of thromboembolic stroke. The effect of TGF-beta 1 as a post-treatment paradigm was investigated in a rabbit model of thromboembolic stroke. Following clot embolization, regional cerebral blood flow fell to < 10 cc 100 g-1 min-1 in all animals. TGF-beta 1 (10 micrograms) or vehicle (n = 5 each group) was infused via the contralateral carotid artery. TGF-beta 1 administration resulted in a rapid and selective reduction in the peripheral neutrophil count as compared to a significant (p < 0.05) increase in control values (2336 +/- 817 vs 4320 +/- 928 neutrophils mm3, mean +/- SEM). Neutrophil aggregation was increased within 30 min of TGF-beta 1 infusion when compared to control (2.07 +/- 0.70 vs 1.09 +/- 0.17 ohms, p < 0.05); neutrophil chemiluminescence, an index of the oxygen respiratory burst was not significantly affected by TGF-beta 1 administration. No difference in platelet counts or aggregation was noted. There was no significant difference between the two groups regarding brain infarct size (47.5 +/- 10.9 vs 56.5 +/- 10.4, n = 4, TGF-beta vs control, mean +/- SEM), intracranial pressure, or brain excitatory amino acid levels (aspartate and glutamate) within ischaemic regions.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Analysis of Variance; Animals; Brain Ischemia; Carotid Arteries; Cell Aggregation; Cerebrovascular Circulation; Disease Models, Animal; Functional Laterality; Infusions, Intra-Arterial; Intracranial Pressure; Leukocyte Count; Luminescent Measurements; Neutrophils; Peroxidase; Platelet Count; Rabbits; Respiratory Burst; Thromboembolism; Transforming Growth Factor beta

The transforming growth factor-beta 1 (TGF-beta 1) has been shown to be an injury-related peptide growth factor within the mammalian brain. We tested TGF-beta 1 for its protective effects against neuronal degeneration caused by sodium cyanide (1 mM) or by the excitatory amino acid L-glutamate (1 mM) in vitro and against ischemic injury in vivo caused by permanent occlusion of the left middle cerebral artery in mice. In vitro, TGF-beta 1 (1-30 ng/ml) significantly reduced hypoxic and excitotoxic neuronal damage in a concentration-dependent manner. In vivo, intracerebroventricular administration of TGF-beta 1 (1 microgram/kg) decreased the infarcted area on the mouse brain surface. The present results suggest that TGF-beta 1 is capable of protecting neurons against damage both in vitro and in vivo.

Topics: Animals; Brain Ischemia; Cells, Cultured; Cerebral Cortex; Chick Embryo; Glutamic Acid; Hypoxia; Male; Mice; Mice, Inbred Strains; Nerve Degeneration; Neurons; Neuroprotective Agents; Rats; Rats, Inbred F344; Telencephalon; Transforming Growth Factor beta

Transforming growth factor-beta 1 (TGF-beta 1) mRNA is induced from 5 h to 3 days following hypoxic-ischaemic brain injury. Cell death also develops during this time suggesting that extracellular accumulation of this peptide may be involved in the processes that regulate cell loss. We examined the effect of rhTGF-beta 1 (0,2.5, 10,50 ng) injected into the cerebral lateral ventricle of rats 2 h after severe hypoxic-ischaemic brain injury. Histological outcome and B4-isolectin histochemistry were assessed 5 and 2 days, respectively following hypoxia. Treatment with 10 ng TGF-beta 1 reduced the microglia reaction (p < 0.05), the magnitude of neuronal loss (p < 0.01) and the area of cortical infarction (p < 0.05). Exogenous TGF-beta 1 given soon after hypoxic-ischaemic brain injury may have therapeutic potential and act by inhibiting the microglial reaction.

Topics: Animals; Brain Ischemia; Cell Death; Cerebral Infarction; Histocytochemistry; Hypoxia, Brain; Injections, Intraventricular; Lectins; Male; Microglia; Neurons; Rats; Rats, Wistar; Transforming Growth Factor beta

Transforming growth factor-beta 1 (TGF-beta 1) has been shown to be an injury-related peptide growth factor within the mammalian central nervous system. We tested whether TGF-beta 1 has the capacity to protect rat neocortical neurons against excitotoxic damage in vitro and mouse neocortex against ischemic injury in vivo. After 14 days in vitro, cultured neurons from rat cerebral cortex were exposed to 1 mM L-glutamate in serum-free culture medium. The cultures received TGF-beta 1 immediately after the addition of glutamate. Eighteen hours later, the cell viability of the cultures was determined using trypan blue exclusion. TGF-beta 1 (1-10 ng/ml) significantly reduced the excitotoxic neuronal damage in a concentration-dependent manner. In vivo, male NMRI mice were subjected to a permanent occlusion of the left middle cerebral artery by microbipolar electrocoagulation. After 48 h, the animals received a transcardiac injection of carbon black. The area of ischemia (devoid of carbon) was restricted to the neocortex and its size was determined planimetrically by means of an image-analyzing system. The treatment with TGF-beta 1 (1 microgram/kg i.c.v.) at 6, 4, or 2 h prior to vessel occlusion reduced the area of ischemia by 5.3, 10.0, and 9.6%, respectively. The effect of the treatment with TGF-beta 1 was statistically significant (p < 0.05 by two-way ANOVA). The present in vitro and in vivo data suggest that TGF-beta 1 has the capacity to diminish the deleterious consequences of an excitotoxic or ischemic insult.

Topics: Animals; Brain Ischemia; Cells, Cultured; Cerebral Cortex; Excitatory Amino Acid Antagonists; Glutamates; Glutamic Acid; Male; Mice; Mice, Inbred Strains; Neurons; Neurotoxins; Rats; Transforming Growth Factor beta

We observed previously that 20 min of global cerebral ischemia followed by 45 min of reperfusion selectively blocked cerebral vasodilation to hypercapnia and hypotension. This study determines the effects of pretreatment with transforming growth factor-beta (TGF-beta) on cerebrovascular responses after cerebral ischemia in piglets equipped with closed cranial windows. Hypercapnia-induced pial arteriolar dilation was blocked after cerebral ischemia (20 +/- 1 vs. 2 +/- 1% dilation before and after ischemia, respectively). Similarly, the increases in periarachnoid cortical cerebrospinal fluid 6-ketoprostaglandin F1 alpha (6-keto-PGF1 alpha) and prostaglandin E2 (PGE2) concentration in response to hypercapnia were blocked (2.5 +/- 0.2- vs. 0.2 +/- 0.4-fold and 2.1 +/- 0.1- vs. 0.3 +/- 0.4-fold increase in 6-keto-PGF1 alpha and PGE2, respectively). Treatment with topical TGF-beta (400 ng/ml) before and during ischemia-reperfusion attenuated the loss of hypercapnia-induced cerebrovascular dilation (20 +/- 1 vs. 14 +/- 1% dilation before and after ischemia, respectively) and the loss of associated changes in cerebrospinal fluid prostanoids (2.0 +/- 0.2- vs. 1.7 +/- 0.2-fold and 2.3 +/- 0.2- vs. 2.2 +/- 0.3-fold increase in 6-keto-PGF1 alpha and PGE2 before and after ischemia, respectively). The loss of cerebrovascular dilation in response to hemorrhagic hypotension after ischemia was similarly prevented by TGF-beta. Cerebrovascular dilation to topical isoproterenol was unchanged after ischemia. TGF-beta may preserve endothelial cell function. We conclude that topical TGF-beta can attenuate cerebromicrovascular compromise caused by ischemia-reperfusion in newborn pigs.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Animals, Newborn; Arterioles; Brain Ischemia; Cerebral Cortex; Cerebrovascular Circulation; Dinoprostone; Female; Hypercapnia; Hypotension; Isoproterenol; Male; Swine; Transforming Growth Factor beta; Vasodilation

The aim of this study was to examine the effect of transforming growth factor-beta 1, a cytokine shown to amelioriate cardiac ischemia, in a rabbit model of thromboembolic stroke.. An autologous clot embolus was introduced intracranially through the right internal carotid artery in 21 New Zealand White rabbits, with seven in each group receiving either vehicle control (albumin) or 10 or 50 micrograms transforming growth factor-beta 1 administered as an intracarotid bolus immediately before autologous clot embolization. Multiple physiological parameters were monitored, including regional cerebral blood flow, arterial blood gases, hematocrit, glucose, core temperature, and mean arterial pressure. The brain was harvested 4 hours after embolization, and infarct size was determined planimetrically as a percentage of the entire hemisphere.. Brain infarct size was reduced in both the 10-microgram (16.7 +/- 4.0% [mean +/- SEM], p < 0.05) and 50-microgram (21.7 +/- 4.5%) transforming growth factor-beta 1-treated groups when compared with the control group (31.9 +/- 6.6%). Regional cerebral blood flow did not show any significant intergroup or intragroup variation over time, although the 10-microgram transforming growth factor-beta 1 group experienced a greater return of cerebral blood flow in the first 2 hours after embolization.. Transforming growth factor-beta 1 reduced brain infarct size in a rabbit model of thromboembolic stroke. This effect was not related to a direct effect on blood flow. Studies are ongoing to determine the mechanism by which transforming growth factor-beta 1 salvages ischemic brain.

Topics: Animals; Blood Glucose; Brain Ischemia; Cerebral Infarction; Cerebrovascular Circulation; Female; Isomerism; Male; Rabbits; Reference Values; Transforming Growth Factor beta

Transforming growth factor beta 1 (TGF beta 1) mRNA expression was examined after hypoxia-ischemia in rat brains using in situ hybridization. Twenty-one-day-old Wistar rats had unilateral ligation of the right carotid artery followed by either 15 or 90 min inhalational hypoxia. Fifteen min of hypoxia resulted in moderate damage with selective neuronal loss in cortical layer 3 and in the hippocampus of the ligated hemisphere. Seventy-two hours after hypoxia TGF beta 1 expression was markedly increased above control levels in those sites. Levels were normal after 120 h. Ninety min of hypoxia led to an infarction of the lateral cerebral cortex and hippocampus of the ligated hemisphere. One hour after hypoxia TGF beta 1 mRNA was expressed in the hippocampus of the damaged side. Seventy-two and 120 h after hypoxia, expressing cells were found throughout the cerebral cortex, piriform cortex, striatum, thalamus and hippocampus of the infarcted side. These data show that TGF beta 1 mRNA expression is induced after a hypoxic-ischemic insult in the brain. TGF beta 1 may be involved in post-asphyxial repair mechanisms.

Topics: Animals; Autoradiography; Brain; Brain Ischemia; Cerebral Cortex; DNA Probes; Hippocampus; Hypoxia, Brain; Neurons; Rats; Rats, Inbred Strains; RNA, Messenger; Sulfur Radioisotopes; Time Factors; Transforming Growth Factor beta