LIM kinase inhibitor T56-LIMKi protects mouse brain from photothrombotic stroke.

: In an ischemic stroke, the damage spreads from the infarction core to surrounding tissues. The present work was aimed at the search of effective neuroprotectors that restrict injury propagation. : We studied possible protective effects of inhibitors of protein kinases LIMK2 (T56-LIMKi), DYRK1A (harmine), and tryptophan hydroxylase (4-chlorophenylalanine) on infarction size and morphology of peri-infarct area after photothrombotic stroke (a model of ischemic stroke) in mouse brain.

The Expression of E2F1, p53, and Caspase 3 in the Rat Dorsal Root Ganglia After Sciatic Nerve Transection.

Neurotrauma is among the main causes of human disability and mortality. Nerve injury impairs not only neurons but also causes death of satellite glial cells remote from the injury site. We studied the dynamics of expression of different proapoptotic proteins (E2F1, p53, caspase 3) in the dorsal root ganglia (DRG) of a rat after sciatic nerve transection.

HDAC1 Expression, Histone Deacetylation, and Protective Role of Sodium Valproate in the Rat Dorsal Root Ganglia After Sciatic Nerve Transection.

Nerve injury is an important reason of human disability and death. We studied the role of histone deacetylation in the response of the dorsal root ganglion (DRG) cells to sciatic nerve transection. Sciatic nerve transection in the rat thigh induced overexpression of histone deacetylase 1 (HDAC1) in the ipsilateral DRG at 1-4 h after axotomy.

The effect of axotomy on firing and ultrastructure of the crayfish mechanoreceptor neurons and satellite glial cells.

Neurotrauma is among main causes of human disability and death. We studied effects of axotomy on ultrastructure and neuronal activity of a simple model object - an isolated crayfish stretch receptor that consists of single mechanoreceptor neurons (MRN) enwrapped by multilayer glial envelope. After isolation, MRN regularly fired until spontaneous activity cessation.

Overexpression of HDAC6, but not HDAC3 and HDAC4 in the penumbra after photothrombotic stroke in the rat cerebral cortex and the neuroprotective effects of α-phenyl tropolone, HPOB, and sodium valproate.

Epigenetic processes play important roles in brain responses to ischemic injury. We studied effects of photothrombotic stroke (PTS, a model of ischemic stroke) on the intracellular level and cellular localization of histone deacetylases HDAC3, HDAC4 and HDAC6 in the rat brain cortex, and tested the potential neuroprotector ability of their inhibitors. The background level of HDAC3, HDAC4 and HDAC6 in the rat cerebral cortex was relatively low.

The Expression and Localization of Histone Acetyltransferases HAT1 and PCAF in Neurons and Astrocytes of the Photothrombotic Stroke-Induced Penumbra in the Rat Brain Cortex.

Stroke is one of the leading reasons of human death. Ischemic penumbra that surrounds the stroke-induced infarction core is potentially salvageable, but molecular mechanisms of its formation are poorly known. Histone acetylation induces chromatin decondensation and stimulates gene expression.

The Localization of p53 in the Crayfish Mechanoreceptor Neurons and Its Role in Axotomy-Induced Death of Satellite Glial Cells Remote from the Axon Transection Site.

Neuron and glia death after axon transection is regulated by various signaling proteins. Protein p53 is a key regulator of diverse cell functions including stress response, DNA repair, proliferation, and apoptosis. We showed that p53 was overexpressed in crayfish ganglia after bilateral axotomy.

The Neuroprotective Effect of the HDAC2/3 Inhibitor MI192 on the Penumbra After Photothrombotic Stroke in the Mouse Brain.

Unilateral photothrombotic stroke caused tissue infarct in the mouse cerebral cortex. The injury of the cerebral cortex impaired the mouse motor activity, in particular the functional asymmetry in forelimb use. In the peri-infarct cortical tissue outside the infarct core cell apoptosis occurred at 4 and 7 days after PTS.

Expression of Histone Deacetylases HDAC1 and HDAC2 and Their Role in Apoptosis in the Penumbra Induced by Photothrombotic Stroke.

In ischemic stroke, vascular occlusion rapidly induces tissue infarct. Over the ensuing hours, damage spreads to adjacent tissue and forms transition zone (penumbra), which is potentially salvageable. Epigenetic regulation of chromatin structure controls gene expression and protein synthesis.

Са- and NF-κB-dependent generation of NO in the photosensitized neurons and satellite glial cells.

Photodynamic therapy (PDT) is used for killing of malignant cells in tumors including brain cancer. It can also damage normal neurons and glial cells. Nitric oxide (NO) is known to control PDT-induced cell death.

Apoptosis regulation in the penumbra after ischemic stroke: expression of pro- and antiapoptotic proteins.

Ischemic stroke is the leading cause of human disability and mortality in the world. The main problem in stroke therapy is the search of efficient neuroprotector capable to rescue neurons in the potentially salvageable transition zone (penumbra), which is expanding after brain damage. The data on molecular mechanisms of penumbra formation and expression of diverse signaling proteins in the penumbra during first 24 h after ischemic stroke are discussed.

Epigenetic Alterations Induced by Photothrombotic Stroke in the Rat Cerebral Cortex: Deacetylation of Histone h3, Upregulation of Histone Deacetylases and Histone Acetyltransferases.

Ischemic penumbra that surrounds a stroke-induced infarction core is potentially salvageable; however, mechanisms of its formation are not well known. Covalent modifications of histones control chromatin conformation, gene expression and protein synthesis. To study epigenetic processes in ischemic penumbra, we used photothrombotic stroke (PTS), a stroke model in which laser irradiation of the rat brain cortex photosensitized by Rose Bengal induces local vessel occlusion.

Axotomy-Induced Changes of the Protein Profile in the Crayfish Ventral Cord Ganglia.

We suggest novel experimental model of nerve injury-bilaterally axotomized ganglia of the crayfish ventral nerve cord (VNC). Using proteomic antibody microarrays, we showed upregulation of apoptosis execution proteins (Bcl-10, caspases 3, 6, and 7, SMAC/DIABLO, AIF), proapoptotic signaling proteins and transcription factors (c-Myc, p38, E2F1, p53, GADD153), and multifunctional proteins capable of initiating apoptosis in specific situations (p75, NMDAR2a) in the axotomized VNC ganglia. Simultaneously, anti-apoptotic proteins (p21WAF-1, MDM2, Bcl-x, Mcl-1, MKP1, MAKAPK2, ERK5, APP, calmodulin, estrogen receptor) were overexpressed.

Ca mediates axotomy-induced necrosis and apoptosis of satellite glial cells remote from the transection site in the isolated crayfish mechanoreceptor.

Severe nerve injury such as axotomy induces neuron degeneration and death of surrounding glial cells. Using a crayfish stretch receptor that consists of a single mechanoreceptor neuron enveloped by satellite glia, we showed that axotomy not only mechanically injures glial cells at the transection location, but also induces necrosis or apoptosis of satellite glial cells remote from the transection site. We studied Carole in spontaneous or axotomy-induced death of remote glial cells.

Photothrombotic Stroke as a Model of Ischemic Stroke.

The search of effective anti-stroke neuroprotectors requires various stroke models adequate for different aspects of the ischemic processes. The photothrombotic stroke model is particularly suitable for the study of cellular and molecular mechanisms underlying neurodegeneration, neuroprotection, and neuroregeneration. It is a model of occlusion of small cerebral vessels, which provides detailed study of molecular mechanisms of ischemic cell death and useful for search of potential anti-stroke agents.

Reactive Oxygen Species Produced by a Photodynamic Effect Induced Calcium Signal in Neurons and Astrocytes.

Photodynamic therapy (PDT) leads to production of reactive oxygen species (ROS) and cell destruction due to oxidative stress. We used photodynamic effect of photosensitizer radachlorin to unravel the effect of photo-induced oxidative stress on the calcium signal and lipid peroxidation in primary culture of cortical neurons and astrocytes using live cell imaging. We have found that irradiation in presence of 200 nM of radachlorin induces calcium signal in primary neurons and astrocytes.

Photo-Induced Oxidative Stress Impairs Mitochondrial Metabolism in Neurons and Astrocytes.

Photodynamic therapy is selective destruction of cells stained with a photosensitizer upon irradiation with light at a specific wavelength in the presence of oxygen. Cell death upon photodynamic treatment is known to occur mainly due to free radical production and subsequent development of oxidative stress. During photodynamic therapy of brain tumors, healthy cells are also damaged; considering this, it is important to investigate the effect of the treatment on normal neurons and glia.

The Focal-Focal Preconditioning Effect of Photothrombotic Impact on the Signaling Protein Profile in the Penumbra Surrounding the Ischemic Core Induced by Another Photothrombotic Impact.

Ischemic tolerance is the establishment of brain resistance to severe ischemic damage by a mild preconditioning stimulus, insufficient to irreversible tissue damage, but capable of initiating a defense response. We developed the model of focal-focal ischemic tolerance, in which the first local photothrombotic infarct (PTI) in the rat brain cortex reduced the infarct caused by second PTI applied to the contralateral cortex of the same rat 7 days later. Using antibody microarrays, we compared protein profiles in the penumbra surrounding the PTI core after single and double PTI.

Involvement of MAPK, Akt/GSK-3β and AMPK/mTOR signaling pathways in protection of remote glial cells from axotomy-induced necrosis and apoptosis in the isolated crayfish stretch receptor.

Severe mechanical nerve injury such as axotomy can lead to neuron degeneration and death of surrounding glial cells. We showed that axotomy not only mechanically injures glial cells at the cutting location, but also induces necrosis or apoptosis of satellite glial cells remote from the transection site. Therefore, axon integrity is necessary for survival of surrounding glial cells.

Photodynamic therapy-induced nitric oxide production in neuronal and glial cells.

Nitric oxide (NO) has been recently demonstrated to enhance apoptosis of glial cells induced by photodynamic therapy (PDT), but to protect glial cells from PDT-induced necrosis in the crayfish stretch receptor, a simple neuroglial preparation that consists of a single mechanosensory neuron enveloped by satellite glial cells. We used the NO-sensitive fluorescent probe 4,5-diaminofluorescein diacetate to study the distribution and dynamics of PDT-induced NO production in the mechanosensory neuron and surrounding glial cells. The NO production in the glial envelope was higher than in the neuronal soma axon and dendrites both in control and in experimental conditions.

Profiling of Signaling Proteins in Penumbra After Focal Photothrombotic Infarct in the Rat Brain Cortex.

In ischemic stroke, cell damage propagates from infarct core to surrounding tissue. To reveal proteins involved in neurodegeneration and neuroprotection, we explored the protein profile in penumbra surrounding the photothrombotic infarct core induced in rat cerebral cortex by local laser irradiation after Bengal Rose administration. Using antibody microarrays, we studied changes in expression of 224 signaling proteins 1, 4, or 24 h after photothrombotic infarct compared with untreated contralateral cortex.

Protein Profile and Morphological Alterations in Penumbra after Focal Photothrombotic Infarction in the Rat Cerebral Cortex.

After ischemic stroke, cell damage propagates from infarct core to surrounding tissues (penumbra). To reveal proteins involved in neurodegeneration and neuroprotection in penumbra, we studied protein expression changes in 2-mm ring around the core of photothrombotic infarct induced in the rat brain cortex by local laser irradiation after administration of Bengal Rose. The ultrastructural study showed edema and degeneration of neurons, glia, and capillaries.