trichostatin-a and Reperfusion-Injury

Innate immune reactions are believed to be associated with ischemia/reperfusion injury (IRI), and IRI might be treatable by expanding regulatory T cells (Tregs), which can suppress the excessive responses of the immune system. Organ IRI is known to be closely involved in the expression of costimulatory molecules. The present study aimed to assess whether Tregs endogenously expanded by the administration of trichostatin A (TsA), a histone deacetylase inhibitor, could reduce renal IRI and to clarify their association with the expression of costimulatory molecules in a murine model. In this study, the wild-type mice used for an IRI model were randomly divided into the following four treatment groups: TsA group, DMSO group (control), DMSO+PC61 group, and TsA + PC61 group. Renal injury in the early phase after IRI was ameliorated in the TsA group (increased Tregs) when compared with the other groups. After renal IRI, both the mRNA and the protein levels of anti-inflammatory cytokines, IL-10 and TGF-β in the kidney and spleen were significantly higher in the TsA group than in the other groups, whereas the IL-6 levels were significantly lower in the TsA group than in the other groups. These results were offset by the administration of PC61, supporting that the renoprotective effect of TsA in this study is Treg dependent. mRNA expression levels of CD80, CD86, and ICAM-1 were lower in the TsA group, consistent with Treg control of injury through costimulatory molecules. Our findings suggest that endogenously expanded Tregs coordinate postischemic immune responses and decrease the expression of costimulatory molecules after renal IRI, and thus, they might ameliorate renal IRI. TsA administration for expanding Tregs is a promising therapeutic strategy for renal IRI.

Topics: Animals; Cell Proliferation; Costimulatory and Inhibitory T-Cell Receptors; Disease Models, Animal; Gene Expression Regulation; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids; Kidney; Lymphocyte Activation; Male; Mice; Mice, Inbred C57BL; Reperfusion Injury; T-Lymphocytes, Regulatory

The current study was undertaken to investigate whether histone deacetylases (HDACs) can modulate the viability of retinal ganglion cells (RGCs) and the activity of glial cells in a mouse model of retinal ischemia-reperfusion (IR) injury. C57BL/6J mice were subjected to constant elevation of intraocular pressure for 60 min to induce retinal IR injury. Expression of macroglial and microglial cell markers (GFAP and Iba1), hypoxia inducing factor (HIF)-1α, and histone acetylation was analyzed after IR injury. To investigate the role of HDACs in the activation of glial cells, overexpression of HDAC1 and HDAC2 isoforms was performed. To determine the effect of HDAC inhibition on RGC survival, trichostatin-A (TSA, 2.5 mg/kg) was injected intraperitoneally. After IR injury, retinal GFAP, Iba1, and HIF-1α were upregulated. Conversely, retinal histone acetylation was downregulated. Notably, adenoviral-induced overexpression of HDAC2 enhanced glial activation following IR injury, whereas overexpression of HDAC1 did not significantly affect glial activation. TSA treatment significantly increased RGC survival after IR injury. Our results suggest that increased activity of HDAC2 is closely related to glial activation in a mouse model of retinal IR injury and inhibition of HDACs by TSA showed neuroprotective potential in retinas with IR injuries.

Topics: Acetylation; Animals; Down-Regulation; Glial Fibrillary Acidic Protein; Histone Deacetylase 2; Histone Deacetylase Inhibitors; Histones; Hydroxamic Acids; Hypoxia-Inducible Factor 1, alpha Subunit; Mice; Neuroglia; Reperfusion Injury; Retina; Retinal Ganglion Cells; Up-Regulation

Hundreds of previous studies demonstrated the cytoprotective effect of trichostatin-A (TSA), a kind of histone deacetylases inhibitors (HDACIs), against cerebral ischemia/reperfusion insult. Meanwhile, phosphatidylinositol-3 kinase/Akt (PI3K/Akt) is a well-known, important signaling pathway that mediates neuroprotection. However, it should be remains unclear whether the neuroprotective capabilities of TSA against cerebral ischemia/reperfusion is mediated by activation of the PI3K/Akt signaling pathway.. Five groups rats (n = 12 each), with middle cerebral artery occlusion (MCAO) except sham group, were used to investigate the neuroprotective effect of certain concentration (0.05 mg/kg) of TSA, and whether the neuroprotective effect of TSA is associated with activation of the PI3K/Akt signaling pathway through using of wortmannin (0.25 mg/kg).. TSA significantly increased the expression of p-Akt protein, reduced infarct volume, and attenuated neurological deficit in rats with transient MCAO, wortmannin weakened such effect of TSA dramatically.. TSA could significantly decrease the neurological deficit scores and reduce the cerebral infarct volume during cerebral ischemia/reperfusion injury, which was achieved partly by activation of the PI3K/Akt signaling pathway via upgrading of p-Akt protein.

Topics: Analysis of Variance; Androstadienes; Animals; Brain Injuries; Brain Ischemia; Disease Models, Animal; Dose-Response Relationship, Drug; Enzyme Inhibitors; Hydroxamic Acids; Male; Nervous System Diseases; Neuroprotective Agents; Oncogene Protein v-akt; Phosphatidylinositol 3-Kinases; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Signal Transduction; Wortmannin

Trichostatin A (TSA) is a histone deacetylase inhibitor with anti-inflammatory effects. Nonetheless, little information is available about the effect of TSA in ischemia-reperfusion (IR)-induced lung injury. In a perfused rat lung model, IR was induced by 40min of ischemia followed by 60min of reperfusion. The rat lungs were randomly divided into several groups including control, control+TSA (0.1mg/kg), IR, and IR+various dosages of TSA (0.05, 0.075, 0.1mg/kg). Bronchoalveolar lavage fluids and lung tissues were obtained and examined at the end of the experiment. TSA dose-dependently diminished IR-induced increased vascular permeability and edema, pulmonary artery pressure, and histological changes in the lungs. Additionally, TSA suppressed lavage tumor necrosis factor-α and cytokine-induced neutrophil chemoattractant concentrations, cell infiltration, and myeloperoxidase-positive cells in the lung tissue. Furthermore, TSA attenuated the phosphorylation of extracellular signal-regulated kinase, p38, and c-Jun N-terminal kinase, degradation of the inhibitor of nuclear factor (NF)-κB, and nuclear NF-κB levels. TSA also decreased poly (ADP-ribose) polymerase but enhanced acetylated histone H3 acetylation, Bcl-2, and mitogen-activated protein kinase phosphatase-1 (MKP-1) expression in IR lung tissue. Therefore, TSA exerted a protective effect on IR-induced lung injury via increasing histone acetylation and MKP-1 protein expression, repressing NF-κB, mitogen-activated protein kinase, and apoptosis signaling pathways.

Topics: Acetylation; Acute Lung Injury; Animals; Anti-Inflammatory Agents; Apoptosis; Arterial Pressure; Bronchoalveolar Lavage Fluid; Chemokine CXCL1; Dual Specificity Phosphatase 1; Histone Deacetylase Inhibitors; Histones; Hydroxamic Acids; Male; Mitogen-Activated Protein Kinases; NF-kappa B; Pulmonary Artery; Rats, Sprague-Dawley; Reperfusion Injury; Signal Transduction; Tumor Necrosis Factor-alpha

Neuroretinal ischemic injury contributes to several degenerative diseases in the eye and the resulting pathogenic processes involving a series of necrotic and apoptotic events. This study investigates the time and extent of changes in acetylation, and whether this influences function and survival of neuroretinal cells following injury. Studies evaluated the time course of changes in histone deacetylase (HDAC) activity, histone-H3 acetylation and caspase-3 activation levels as well as retinal morphology and function (electroretinography) following ischemia. In addition, the effect of two HDAC inhibitors, trichostatin-A and valproic acid were also investigated. In normal eyes, retinal ischemia produced a significant increase in HDAC activity within 2 h that was followed by a corresponding significant decrease in protein acetylation by 4 h. Activated caspase-3 levels were significantly elevated by 24 h. Treatment with HDAC inhibitors blocked the early decrease in protein acetylation and activation of caspase-3. Retinal immunohistochemistry demonstrated that systemic administration of trichostatin-A or valproic acid, resulted in hyperacetylation of all retinal layers after systemic treatment. In addition, HDAC inhibitors provided a significant functional and structural neuroprotection at seven days following injury relative to vehicle-treated eyes. These results provide evidence that increases in HDAC activity is an early event following retinal ischemia, and are accompanied by corresponding decreases in acetylation in advance of caspase-3 activation. In addition to preserving acetylation status, the administration of HDAC inhibitors suppressed caspase activation and provided structural and functional neuroprotection in model of ischemic retinal injury. Taken together these data provide evidence that decrease in retinal acetylation status is a central event in ischemic retinal injury, and the hyperacetylation induced by HDAC inhibition can provide acute neuroprotection.

Topics: Acetylation; Animals; Blotting, Western; Caspase 3; Cell Survival; Electroretinography; Female; Histone Deacetylase Inhibitors; Histone Deacetylases; Histones; Hydroxamic Acids; Lysine; Male; Neuroprotective Agents; Rats, Inbred BN; Reperfusion Injury; Retinal Degeneration; Retinal Neurons; Valproic Acid

Protein acetylation is an essential mechanism in regulating transcriptional and inflammatory events. Studies have shown that nonselective histone deacetylase (HDAC) inhibitors can protect the retina from ischemic injury in rats. However, the role of specific HDAC isoforms in retinal degenerative processes remains obscure. The purpose of this study was to investigate the role of HDAC2 isoform in a mouse model of ischemic retinal injury.. Localization of HDAC2 in mice retinas was evaluated by immunohistochemical analyses. To investigate whether selective reduction in HDAC2 activity can protect the retina from ischemic injury, Hdac2⁺/⁻ mice were utilized. Electroretinographic (ERG) and morphometric analyses were used to assess retinal function and morphology.. Our results demonstrated that HDAC2 is primarily localized in nuclei in inner nuclear and retinal ganglion cell layers, and HDAC2 activity accounted for approximately 35% of the total activities of HDAC1, 2, 3, and 6 in the retina. In wild-type mice, ERG a- and b-waves from ischemic eyes were significantly reduced when compared to pre-ischemia baseline values. Morphometric examination of these eyes revealed significant degeneration of inner retinal layers. In Hdac2⁺/⁻ mice, ERG a- and b-waves from ischemic eyes were significantly greater than those measured in ischemic eyes from wild-type mice. Morphologic measurements demonstrated that Hdac2⁺/⁻ mice exhibit significantly less retinal degeneration than wild-type mice.. This study demonstrated that suppressing HDAC2 expression can effectively reduce ischemic retinal injury. Our results support the idea that the development of selective HDAC2 inhibitors may provide an efficacious treatment for ischemic retinal injury.

Topics: Animals; Disease Models, Animal; Electroretinography; Histone Deacetylase 2; Histone Deacetylase Inhibitors; Hydroxamic Acids; Mice; Mice, Inbred C57BL; Mice, Knockout; Reperfusion Injury; Retina; Retinal Degeneration; Retinal Ganglion Cells

To explore the impact on cerebral protection of Trichostatin A (TSA) preconditioning in rats with middle cerebral artery occlusion (MCAO); the relationship between cerebral protection of TSA and interleukin-1 beta (IL-1β); and the impact of age on the mechanism of cerebral protection of TSA.. The modified suture method was used to create stable a MCAO model. A total of 96 male SD rats were assigned randomly to four groups: a control group, a dimethyl sulfoxide (DMSO) preconditioned group, a low-dose (0.03 mg/kg) TSA-preconditioned group, and a high-dose (0.1 mg/kg) TSA-preconditioned group. Each group included four sub-groups for reperfusion for 6, 12, 24 and 48 hours, respectively, 6 rats per sub-group. An additional, eighteen healthy, male Sprague Dawley (SD) rats that received TSA preconditioning (0.1 mg/kg) were divided into three groups based on their age: young, mid-age, and old, One-way analysis of variance was used to compare the differences between groups, and the Spearman rank correlation was used to examine relationships between IL-1β concentrations in blood and cerebrospinal fluid and cerebral infarction volume.. The cerebral infarction volume of rats in the high-dose TSA group was less than that of the other 3 groups (P<0.05). The IL-1β in blood and the cerebrospinal fluid of rats in the highdose TSA group was lower than that in control and DMSO groups (P<0.05); for the low-dose TSA group IL-1β levels were statistically the same as in controls. The Spearman rank coefficients were 0.841 and 0.618 for cerebral infarction volume correlate to blood IL-1β and to cerebrospinal fluid IL-1β, respectively (P<0.05). No statistical differences were found in cerebral infarction volume and IL-1β levels in blood or cerebrospinal fluid (P>0.05).. High-dose TSA preconditioning reduces cerebral infarction volume and decreases IL- 1β levels in blood and cerebrospinal fluid; age does not affect these parameters.

Topics: Animals; Histone Deacetylase Inhibitors; Hydroxamic Acids; Infarction, Middle Cerebral Artery; Interleukin-1beta; Ischemic Preconditioning; Male; Rats; Reperfusion Injury

PURPOSE. The pathogenesis of retinal ischemia results from a series of events involving changes in gene expression and inflammatory cytokines. Protein acetylation is an essential mechanism in regulating transcriptional and inflammatory events. The purpose of this study was to investigate the neuroprotective action of the histone deacetylase (HDAC) inhibitor trichostatin A (TSA) in a retinal ischemic model. METHODS. To investigate whether HDAC inhibition can reduce ischemic injury, rats were treated with TSA (2.5 mg/kg intraperitoneally) twice daily on days 0, 1, 2, and 3. Seven days after ischemic injury, morphometric and electroretinographic (ERG) analyses were used to assess retinal structure and function. Western blot and immunohistochemical analyses were used to evaluate TSA-induced changes in histone-H3 acetylation and MMP secretion. RESULTS. In vehicle-treated animals, ERG a- and b-waves from ischemic eyes were significantly reduced compared with contralateral responses. In addition, histologic examination of these eyes revealed significant degeneration of inner retinal layers. In rats treated with TSA, amplitudes of ERG a- and b-waves from ischemic eyes were significantly increased, and normal inner retina morphology was preserved. Ischemia also increased the levels of retinal TNF-alpha, which was blocked by TSA treatment. In astrocyte cultures, the addition of TNF-alpha (10 ng/mL) stimulated the secretion of MMP-1 and MMP-3, which were blocked by TSA (100 nM). CONCLUSIONS. These studies provide the first evidence that suppressing HDAC activity can protect the retina from ischemic injury. This neuroprotective response is associated with the suppression of retinal TNF-alpha expression and signaling. The use of HDAC inhibitors may provide a novel treatment for ischemic retinal injury.

Topics: Acetylation; Animals; Blotting, Western; Electroretinography; Female; Histone Deacetylase Inhibitors; Histone Deacetylases; Histones; Hydroxamic Acids; Immunohistochemistry; Male; Matrix Metalloproteinase 1; Matrix Metalloproteinase 3; Neuroprotective Agents; Rats; Rats, Inbred BN; Reperfusion Injury; Retina; Retinal Diseases; Tumor Necrosis Factor-alpha

We have recently shown that the inhibition of histone deacetylases (HDAC) protects the heart against ischemia and reperfusion (I/R) injury. The mechanism by which HDAC inhibition induces cardioprotection remains unknown. We sought to investigate whether the genetic disruption of gp-91, a subunit of NADPH-oxidase, would mitigate cardioprotection of HDAC inhibition. Wild-type and gp-91(-)(/-) mice were treated with a potent inhibitor of HDACs, trichostatin A (TSA, 0.1 mg/kg, i.p.). Twenty-four hours later, the perfused hearts were subjected to 30 min of ischemia and 30 min of reperfusion. HDAC inhibition in wild-type mice produced marked improvements in ventricular functional recovery and the reduction of infarct size. TSA-induced cardioprotection was eliminated with genetic deletion of gp91. Notably, Western blot and immunostaining displayed a significant increase in gp-91 in myocardium following HDAC inhibition, which resulted in a mildly subsequent increase in the production of reactive oxygen species (ROS). The pre-treatment of H9c2 cardiomyoblasts with TSA (50 nmol/l) decreased cell necrosis and increased viability in response to simulated ischemia (SI), which was abrogated by the transfection of cells with gp-91 siRNA, but not by scrambled siRNA. Furthermore, treatment of PLB-985 gp91(+/+) cells with TSA increased the resistance to SI, which also diminished with genetic disruption of gp91 in gp91(phox)-deficient PLB-985 cells. TSA treatment inhibited the increased active caspase-3 in H9c2 cardiomyoblasts and PLB-985 gp91(+/+) cells exposed to SI, which were prevented by knockdown of gp-91 by siRNA. These results suggest that a cascade consisting of gp-91 and HDAC inhibition plays an essential role in orchestrating the cardioprotective effect.

Topics: Animals; Apoptosis; Cardiotonic Agents; Cell Survival; Heart; Histone Deacetylase Inhibitors; Histone Deacetylases; Hydroxamic Acids; Male; Membrane Glycoproteins; Mice; Mice, Inbred C57BL; Mice, Knockout; Myocardium; NADPH Oxidase 2; NADPH Oxidases; Random Allocation; Reactive Oxygen Species; Reperfusion Injury; RNA, Small Interfering