Ceftriaxone therapy attenuates brain trauma in rats by affecting glutamate transporters and neuroinflammation and not by its antibacterial effects

Abstract Background Ceftriaxone is a β-lactam antibiotic used to treat central nervous system infections. Whether the neuroprotective effects of ceftriaxone after TBI are mediated by attenuating neuroinflammation but not its antibacterial actions is not well established. Methods Anesthetized male Sprague–Dawley rats were divided into sham-operated, TBI + vehicle, and TBI + ceftriaxone groups. Ceftriaxone was intraperitoneally injected at 0, 24, and 48 h with 50 or 250 mg/kg/day after TBI. During the first 120 min after TBI, we continuously measured heart rate, arterial pressure, intracranial pressure (ICP), and cerebral perfusion pressure. The infarct volume was measured by TTC staining. Motor function was measured using the inclined plane. Glutamate transporter 1 (GLT-1), neuronal apoptosis and TNF-α expression in the perilesioned cortex were investigated using an immunofluorescence assay. Bacterial evaluation was performed by Brown and Brenn’s Gram staining. These parameters above were measured at 72 h after TBI. Results Compared with the TBI + vehicle group, the TBI + ceftriaxone 250 mg/kg group showed significantly lower ICP, improved motor dysfunction, reduced body weight loss, decreased infarct volume and neuronal apoptosis, decreased TBI-induced microglial activation and TNF-α expression in microglia, and increased GLT-1 expression in neurons and microglia. However, the grades of histopathological changes of antibacterial effects are zero. Conclusions The intraperitoneal injection of ceftriaxone with 250 mg/kg/day for three days may attenuate TBI by increasing GLT-1 expression and reducing neuroinflammation and neuronal apoptosis, thereby resulting in an improvement in functional outcomes, and this neuroprotective effect is not related to its antibacterial effects.

Download Full-text

The neuroprotective effects of AMN082 on neuronal apoptosis in rats after traumatic brain injury

BMC Neuroscience ◽

10.1186/s12868-021-00649-w ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Chung-Che Lu ◽

Tee-Tau Eric Nyam ◽

Jinn-Rung Kuo ◽

Yao-Lin Lee ◽

Chung-Ching Chio ◽

...

Keyword(s):

Traumatic Brain Injury ◽

Brain Injury ◽

Glutamate Receptor ◽

Neuronal Apoptosis ◽

Nitrosative Stress ◽

Infarct Volume ◽

Neuroprotective Effect ◽

Motor Deficits ◽

Sprague Dawley ◽

Neuroprotective Effects

Abstract Background The aim of this study was to investigate whether AMN082 exerts its neuroprotective effect by attenuating glutamate receptor-associated neuronal apoptosis and improving functional outcomes after traumatic brain injury (TBI). Methods Anesthetized male Sprague–Dawley rats were divided into the sham-operated, TBI + vehicle, and TBI + AMN082 groups. AMN082 (10 mg/kg) was intraperitoneally injected 0, 24, or 48 h after TBI. In the 120 min after TBI, heart rate, mean arterial pressure, intracranial pressure (ICP), and cerebral perfusion pressure (CPP) were continuously measured. Motor function, the infarct volume, neuronal nitrosative stress-associated apoptosis, and N-methyl-d-aspartate receptor 2A (NR2A) and NR2B expression in the pericontusional cortex were measured on the 3rd day after TBI. Results The results showed that the AMN082-treated group had a lower ICP and higher CPP after TBI. TBI-induced motor deficits, the increase in infarct volume, neuronal apoptosis, and 3-nitrotyrosine and inducible nitric oxide synthase expression in the pericontusional cortex were significantly improved by AMN082 therapy. Simultaneously, AMN082 increased NR2A and NR2B expression in neuronal cells. Conclusions We concluded that intraperitoneal injection of AMN082 for 3 days may ameliorate TBI by attenuating glutamate receptor-associated nitrosative stress and neuronal apoptosis in the pericontusional cortex. We suggest that AMN082 administration in the acute stage may be a promising strategy for TBI.

Download Full-text

The neuroprotective effects of AMN082 on neuronal apoptosis in rat after traumatic brain injury

10.21203/rs.3.rs-121579/v1 ◽

2020 ◽

Author(s):

Chung-Che Lu ◽

Che-Chuan Wang ◽

Yao-Lin Lee ◽

Chung-Ching Chio ◽

Sher-Wei Lim ◽

...

Keyword(s):

Traumatic Brain Injury ◽

Brain Injury ◽

Neuronal Apoptosis ◽

Nitrosative Stress ◽

Neuroprotective Effect ◽

Acute Stage ◽

Motor Deficits ◽

Sprague Dawley ◽

Neuroprotective Effects ◽

Infarction Volume

Abstract The aim of this study is to investigate whether the neuroprotective effect of AMN082 is via attenuating glutamic receptor associated neuronal apoptosis and improves functional outcomes after traumatic brain injury (TBI). Anesthetized male Sprague-Dawley rats were divided into sham-operated, TBI + vehicle, and TBI + AMN082 groups. AMN082 was intraperitoneally injected (10 mg/kg) at 0, 24, and 48 hr after TBI. During the 120 minutes after TBI, heart rate, mean arterial pressure, intracranial pressure (ICP), and cerebral perfusion pressure (CPP) were continuously measured. The motor function, infarction volume, and neuronal nitrosative stress-associated apoptosis, N-Methyl-D-aspartate receptor 2A (NR2A) and NR2B expression were measured on the 3rd day after TBI. The results showed AMN082-treated group had the lower ICP and higher CPP after TBI. The TBI-induced motor deficits, increased infarction volume, neuronal apoptosis, 3-nitrotyrosine and inducible nitric oxide synthase expression in the peri-contusion cortex were significantly improved by AMN082 therapy. Simultaneously, AMN082 increased the NR2A and NR2B expression in neuronal cells. We concluded intraperitoneal injection of AMN082 for 3 days may ameliorate TBI insults by attenuating glutamic receptor associated nitrosative stress and neuronal apoptosis in the peri-contusion cortex. We suggest AMN082 administration in acute stage may be a promising strategy for TBI.

Download Full-text

Abstract W MP94: Neuroprotective Effect of Isosteviol Sodium on Focal Cerebral Ischemia in Rats

Stroke ◽

10.1161/str.46.suppl_1.wmp94 ◽

2015 ◽

Vol 46 (suppl_1) ◽

Author(s):

Hui Hu ◽

Qing Liu ◽

Fang Tian ◽

Hao Zhang ◽

DaiXin Qu ◽

...

Keyword(s):

Proteomic Analysis ◽

Focal Cerebral Ischemia ◽

Infarct Volume ◽

Therapeutic Window ◽

Vehicle Group ◽

Signal Pathways ◽

Neuroprotective Effects ◽

Doppler Flowmetry ◽

Neurobehavioral Deficits ◽

Dosage Study

Background & Objective: Isosteviol is a molecule derived from Steviaside which has been used as sweetener worldwide. In this study, sodium salt of isosteviol (STVNA) was given i.v. in rats hours after the transient or permanent middle cerebral artery occlusion (tMCAO or pMCAO) to investigate its therapeutic neuroprotective effects. Methods: In male Sprague-Dawley rats 2 hours tMCAO with reperfusion or pMCAO was induced and ischemia were confirmed by a laser doppler flowmetry simultaneously. In dosage study, animals were divided into 6 groups: sham, vehicle, or treatment with STVNA at dosage of 1, 5, 10mg•kg-1 or Edaravone 1 hour before the onset of reperfusion. In therapeutic time window study, animals were divided into 5 groups: sham, vehicle, STVNA (10mg•kg-1) at 0, 2 or 4 hours after reperfusion. In pMCAO study, animals were divided into 5 groups: sham, vehicle or STVNA (10mg•kg-1) at 1, 2 or 4 hours after ischemia. Rats were assessed for neurobehavioral deficits after 24 hours and sacrificed for infarct volume quantitation and histology evaluation. Proteomic analysis of the penumbra area in some rats used a Snaps G2x MS-TOF system. Results: In dosage study, the infarct volume of STVNA 10mg•kg-1 group was significantly less compared either with the vehicle group (22±2% vs 41±5%, p< 0.01) or with the Edaravone group (22±2% vs 30±3%, p< 0.05 ). The therapeutic window study shows that STVNA treated at 4h after reperfusion still has significant effects than vehicle group (32±4% vs 41±5%, p<0.05). In pMCAO study, the infarct volume of STVNA at 4h still decreased comparing the vehicle group(29±5% vs 50±6%, p< 0.05).In all STVNA treated groups the neurobehavioral deficits were significantly improved, and there are more restored NeuN-labeled neurons and alleviated TUNEL positive cells in penumbra in comparing with the vehicle group. Proteomic analysis indicates that proteins involved in various inflammations associated signal pathways were dramatically increased by tMCAO, and then were greatly reduced after treated with STVNA. Conclusions: STVNA exhibited remarkable neuroprotective effects when administered 4 hours after pMCAO or 4 hours after reperfusion of tMCAO. Since STVNA has low systemic toxicity, it may be a better alternative for the treatment of stroke.

Download Full-text

Peptide TFP5/TP5 derived from Cdk5 activator P35 provides neuroprotection in the MPTP model of Parkinson’s disease

Molecular Biology of the Cell ◽

10.1091/mbc.e15-06-0415 ◽

2015 ◽

Vol 26 (24) ◽

pp. 4478-4491 ◽

Cited By ~ 19

Author(s):

BK. Binukumar ◽

Varsha Shukla ◽

Niranjana D. Amin ◽

Philip Grant ◽

M. Bhaskar ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Neurodegenerative Disorder ◽

Neuroprotective Effect ◽

Selective Inhibition ◽

Motor Dysfunction ◽

Dopamine Neurons ◽

Dopamine Depletion ◽

Neuroprotective Effects

Parkinson’s disease (PD) is a chronic neurodegenerative disorder characterized by the loss of dopamine neurons in the substantia nigra, decreased striatal dopamine levels, and consequent extrapyramidal motor dysfunction. Recent evidence indicates that cyclin-dependent kinase 5 (Cdk5) is inappropriately activated in several neurodegenerative conditions, including PD. To date, strategies to specifically inhibit Cdk5 hyperactivity have not been successful without affecting normal Cdk5 activity. Previously we reported that TFP5 peptide has neuroprotective effects in animal models of Alzheimer’s disease. Here we show that TFP5/TP5 selective inhibition of Cdk5/p25 hyperactivation in vivo and in vitro rescues nigrostriatal dopaminergic neurodegeneration induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP/MPP+) in a mouse model of PD. TP5 peptide treatment also blocked dopamine depletion in the striatum and improved gait dysfunction after MPTP administration. The neuroprotective effect of TFP5/TP5 peptide is also associated with marked reduction in neuroinflammation and apoptosis. Here we show selective inhibition of Cdk5/p25 hyperactivation by TFP5/TP5 peptide, which identifies the kinase as a potential therapeutic target to reduce neurodegeneration in Parkinson’s disease.

Download Full-text

Abstract 173: The Neuroprotective Effect Of JZL184 is Comparable With Therapeutic Hypothermia in a Rat Model of Cardiac Arrest

Circulation ◽

10.1161/circ.140.suppl_2.173 ◽

2019 ◽

Vol 140 (Suppl_2) ◽

Author(s):

Jing Xu ◽

Guanghui Zheng ◽

Juntao Hu ◽

Weiwei Ge ◽

Jennifer Bradley ◽

...

Keyword(s):

Cardiac Arrest ◽

Therapeutic Hypothermia ◽

Rat Model ◽

Neuroprotective Effect ◽

Experimental Studies ◽

Flow Index ◽

Protective Effects ◽

Cerebral Microcirculation ◽

Sprague Dawley ◽

Neuroprotective Effects

Introduction: JZL184 is a synthetic monoacylglycerol lipase inhibitor that reduces brain edema, infarct size and alleviates inflammation following cerebral ischemia in experimental studies. In this study, we compared its cerebral protective effects with therapeutic hypothermia following cardiopulmonary resuscitation (CPR) in a rat model. Hypothesis: JZL184 will have similar neuroprotective effects to therapeutic hypothermia after cardiac arrest (CA) by reducing brain and blood brain barrier (BBB) injury and preserving cerebral microcirculation following CPR. Methods: Thirty six male Sprague-Dawley rats weighing between 450-550 g were randomized: 1) control 2) hypothermia 3) JZL184. Ventricular fibrillation was induced and untreated for 6 min for all rats. Resuscitation was attempted with a 4 Joule defibrillation after 8 min of CPR. Immediately following resuscitation, either hypothermia (33+0.5 o C) or JZL184 (16 mg/k, IP) was administered. Cerebral microcirculation, S-100β, NSE and Evan’s Blue (EB) concentrations were analyzed at 6hrs after resuscitation. Results: NSE and S-100β levels were higher in control compared to hypothermia and JZL18 at 6hr post ROSC (p < 0.001) (Fig. 1). Compared with control, there was a significant decrease in brain permeability to EB in Hypothermia and JZL184 after 6hr post ROSC (p<0.001) (Fig. 2). Microvascular flow index (MFI) was reduced in control compared with hypothermia and JZL184 6hr post ROSC (p <0.01). Conclusions: JZL184 administered following resuscitation reduced brain and BBB injury and preserved cerebral microcirculation at 6 hr post arrest to the same extent as hypothermia in a rat model of cardiac arrest.

Download Full-text

Abstract WP272: A Powerful Combination Therapy for Stroke: Post-Ischemia Ethanol Administration and Normobaric Oxygenation on Ischemic Rats

Stroke ◽

10.1161/str.44.suppl_1.awp272 ◽

2013 ◽

Vol 44 (suppl_1) ◽

Author(s):

Christopher Sy ◽

Xiaokun Geng ◽

Paul Fu ◽

Changya Peng ◽

Vance Fredrickson ◽

...

Keyword(s):

Combination Therapy ◽

Protein Expression ◽

Infarct Volume ◽

Neuroprotective Effect ◽

Artery Occlusion ◽

Neurological Deficits ◽

Ethanol Administration ◽

Acute Administration ◽

Sprague Dawley ◽

Acute Cerebral Ischemia

Objectives: Normobaric oxygenation (NBO) has been reported to be neuroprotective against acute cerebral ischemia. Recently, a clinical trial was terminated because beneficial outcomes were not definitive. Our recent study ( Stroke. 2012 43(1):205-10 ) demonstrated a strong neuroprotective effect induced by acute administration of ethanol (EtOH) at 1.5g/kg. In this study, we assessed the therapeutic influence of EtOH in combination with NBO. Methods: Sprague-Dawley rats were subjected to right middle cerebral artery occlusion for 2h. Ischemic animals received either an intraperitoneal injection of EtOH (1.0g/kg), a course of NBO (100% for 2h), or a combination of both immediately prior to reperfusion onset. Brain injury was determined by infarct volume and behavioral outcomes at 48h post-reperfusion. Metabolic dysfunction was investigated by assessing ADP/ATP ratios, reactive oxygen species (ROS) levels, NADPH oxidase (NOX) activity, and protein expression of NOX subunits (p47 phox , gp91 phox , and p67 phox ), as well as the protein expression and enzyme activity of pyruvate dehydrogenase (PDH), at both 3h and 24h after reperfusion. Results: Combination therapy led to a significant decrease in infarct volumes (Saline: 48±4%, EtOH: 38±3%, NBO: 37±4%, Combination: 19±3% ) and in neurological deficits (Belayev Scale 0-12, Saline: 8.4±0.7; EtOH: 6.5±0.7; NBO: 6.4±0.6; Combination: 4.4±0.3 ). At 3h and 24h post-reperfusion the decrease in ADP/ATP ratio was significantly enhanced, reflecting a preservation of cellular energy. A greater decrease in NOX activity and protein expression was observed, in association with decreased ROS levels, suggesting that improved glycolysis may contribute to neuroprotection. PDH activity and protein expression was dramatically increased, making the facilitation of aerobic metabolism a probable mechanism for preserving cellular ATP. Conclusions: Our findings demonstrate that a synergistic relationship exists between EtOH and NBO. Both are promising neuroprotective agents when used together, even at low doses. Moreover, both are inexpensive, widely available, easy to administer, and have little side effects. Thus, combination therapy could be an effective and efficient approach to future stroke treatments.

Download Full-text

Rh-CSF1 Attenuates Oxidative Stress and Neuronal Apoptosis via the CSF1R/PLCG2/PKA/UCP2 Signaling Pathway in a Rat Model of Neonatal HIE

Oxidative Medicine and Cellular Longevity ◽

10.1155/2020/6801587 ◽

2020 ◽

Vol 2020 ◽

pp. 1-20

Author(s):

Xiao Hu ◽

Shirong Li ◽

Desislava Met Doycheva ◽

Lei Huang ◽

Cameron Lenahan ◽

...

Keyword(s):

Oxidative Stress ◽

Signaling Pathway ◽

Rat Model ◽

Neuronal Apoptosis ◽

Neuronal Degeneration ◽

Infarct Volume ◽

Neurological Deficits ◽

Tunel Staining ◽

Artery Ligation ◽

Neuroprotective Effects

Oxidative stress (OS) and neuronal apoptosis are major pathological processes after hypoxic-ischemic encephalopathy (HIE). Colony stimulating factor 1 (CSF1), binding to CSF1 receptor (CSF1R), has been shown to reduce neuronal loss after hypoxic-ischemia- (HI-) induced brain injury. In the present study, we hypothesized that CSF1 could alleviate OS-induced neuronal degeneration and apoptosis through the CSF1R/PLCG2/PKA/UCP2 signaling pathway in a rat model of HI. A total of 127 ten-day old Sprague Dawley rat pups were used. HI was induced by right common carotid artery ligation with subsequent exposure to hypoxia for 2.5 h. Exogenous recombinant human CSF1 (rh-CSF1) was administered intranasally at 1 h and 24 h after HI. The CSF1R inhibitor, BLZ945, or phospholipase C-gamma 2 (PLCG2) inhibitor, U73122, was injected intraperitoneally at 1 h before HI induction. Brain infarct volume measurement, cliff avoidance test, righting reflex test, double immunofluorescence staining, western blot assessment, 8-OHdG and MitoSOX staining, Fluoro-Jade C staining, and TUNEL staining were used. Our results indicated that the expressions of endogenous CSF1, CSF1R, p-CSF1R, p-PLCG2, p-PKA, and uncoupling protein2 (UCP2) were increased after HI. CSF1 and CSF1R were expressed in neurons and astrocytes. Rh-CSF1 treatment significantly attenuated neurological deficits, infarct volume, OS, neuronal apoptosis, and degeneration at 48 h after HI. Moreover, activation of CSF1R by rh-CSF1 significantly increased the brain tissue expressions of p-PLCG2, p-PKA, UCP2, and Bcl2/Bax ratio, but reduced the expression of cleaved caspase-3. The neuroprotective effects of rh-CSF1 were abolished by BLZ945 or U73122. These results suggested that rh-CSF1 treatment attenuated OS-induced neuronal degeneration and apoptosis after HI, at least in part, through the CSF1R/PLCG2/PKA/UCP2 signaling pathway. Rh-CSF1 may serve as therapeutic strategy against brain damage in patients with HIE.

Download Full-text

Triggering Receptor Expressed on Myeloid Cells 2, a Novel Regulator of Immunocyte Phenotypes, Confers Neuroprotection by Relieving Neuroinflammation

Anesthesiology ◽

10.1097/aln.0000000000001628 ◽

2017 ◽

Vol 127 (1) ◽

pp. 98-110 ◽

Cited By ~ 18

Author(s):

Qian Zhai ◽

Feng Li ◽

Xiyao Chen ◽

Ji Jia ◽

Sisi Sun ◽

...

Keyword(s):

Neuronal Apoptosis ◽

Infarct Volume ◽

Neuroprotective Effect ◽

Ischemia Reperfusion ◽

Intraperitoneal Administration ◽

Myeloid Cells ◽

Glucose Deprivation ◽

Interleukin 4 ◽

Oxygen Glucose Deprivation

Abstract Background Microglia can not only detrimentally augment secondary injury but also potentially promote recovery. However, the mechanism underlying the regulation of microglial phenotypes after stroke remains unclear. Methods Mice were subjected to middle cerebral artery occlusion for 60 min. At 3 days after reperfusion, the effects of activation and suppression of triggering receptor expressed on myeloid cells 2 on immunocyte phenotypes (n = 5), neurobehavioral scores (n = 7), infarct volumes (n = 8), and neuronal apoptosis (n = 7) were analyzed. In vitro, cultured microglia were exposed to oxygen–glucose deprivation for 4 h. Inflammatory cytokines, cellular viability (n = 8), neuronal apoptosis (n = 7), and triggering receptor expressed on myeloid cells 2 expression (n = 5) were evaluated in the presence or absence of triggering receptor expressed on myeloid cell-specific small interfering RNA or triggering receptor expressed on myeloid cells 2 overexpression lentivirus. Results Triggering receptor expressed on myeloid cells 2 expression in the ischemic penumbra peaked at 3 days after ischemia–reperfusion injury (4.4 ± 0.1-fold, P = 0.0004) and was enhanced in interleukin-4/interleukin-13–treated microglia in vitro (1.7 ± 0.2-fold, P = 0.0119). After oxygen–glucose deprivation, triggering receptor expressed on myeloid cells 2 conferred neuroprotection by regulating the phenotypic conversion of microglia and inflammatory cytokine release. Intraperitoneal administration of triggering receptor expressed on myeloid cells 2 agonist heat shock protein 60 or unilateral delivery of a recombinant triggering receptor expressed on myeloid cells 2 lentivirus into the cerebral ventricle induced a significant neuroprotective effect in mice (apoptotic neurons decreased to 31.3 ± 7.6%; infarct volume decreased to 44.9 ± 5.3%). All values are presented as the mean ± SD. Conclusions Activation or up-regulation of triggering receptor expressed on myeloid cells 2 promoted the phenotypic conversion of microglia and decreased the number of apoptotic neurons. Our study suggests that triggering receptor expressed on myeloid cells 2 is a novel regulator of microglial phenotypes and may be a potential therapeutic target for stroke.

Download Full-text

Sevoflurane Preconditioning against Focal Cerebral Ischemia

Anesthesiology ◽

10.1097/aln.0b013e3181a1fe68 ◽

2009 ◽

Vol 110 (6) ◽

pp. 1271-1278 ◽

Cited By ~ 59

Author(s):

Jean-Laurent Codaccioni ◽

Lionel J. Velly ◽

Chahrazad Moubarik ◽

Nicolas J. Bruder ◽

Pascale S. Pisano ◽

...

Keyword(s):

Cerebral Ischemia ◽

Focal Cerebral Ischemia ◽

Infarct Volume ◽

Cerebral Injury ◽

Terminal Deoxynucleotidyl Transferase ◽

Control Group ◽

Sprague Dawley ◽

Nissl Staining ◽

Neuroprotective Effects ◽

Sevoflurane Preconditioning

Background Preconditioning the brain with volatile anesthetics seems to be a viable option for reducing ischemic cerebral injury. However, it is uncertain whether this preconditioning effect extends over a longer period of time. The purpose of this study was to determine if sevoflurane preconditioning offers durable neuroprotection against cerebral ischemia. Methods Rats (Sprague-Dawley) were randomly allocated to two groups: nonpreconditioned control group (n = 44) and preconditioned group (n = 45) exposed to 2.7 vol% sevoflurane (45 min) 60 min before surgery. Animals in both groups were anesthetized with 3.0 vol% sevoflurane and subjected to transient middle cerebral artery occlusion. After 60 min of awake focal ischemia, the filament was removed. Functional neurologic outcome (range 0-18; 0 = no deficit), cerebral infarct size (Nissl staining), and apoptosis (Terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate nick-end labeling; cleaved caspase-3 staining) were evaluated at 3, 7, and 14 days after ischemia. Results Sevoflurane preconditioning significantly improved functional outcome and reduced infarct volume (109 +/- 43 vs. 148 +/- 56 mm(3)) 3 days after ischemia compared to the control group. However, after 7- and 14-day recovery periods, no significant differences were observed between groups. The number of apoptotic cells was significantly lower in the preconditioned group than in the control group after 3- and 7-day recovery periods. Fourteen days after ischemia, no differences were observed between groups. Conclusion In this model of transient focal cerebral ischemia, sevoflurane preconditioning induced effective but transient neuroprotective effects. Sevoflurane preconditioning also decreased ischemia-induced apoptosis in a more sustained way because it was observed up to 7 days after injury.

Download Full-text

Abstract TP84: Comparative Analysis of Genetic and Pharmacological Inhibition of Sirt3 in Post Ischemic Injury

Stroke ◽

10.1161/str.48.suppl_1.tp84 ◽

2017 ◽

Vol 48 (suppl_1) ◽

Author(s):

Rajkumar Verma ◽

Rodney Ritzel ◽

Bruce Liang ◽

Louise McCullough

Keyword(s):

Focal Cerebral Ischemia ◽

Infarct Volume ◽

Neuroprotective Effect ◽

Ischemia Reperfusion ◽

Pharmacological Study ◽

Ischemic Injury ◽

Target Protein ◽

Cns Injury ◽

Neuroprotective Effects ◽

Pharmacological Inhibition

Background: Sirtuin3 (Sirt3), NAD+-dependent deacetylase, regulates several key proteins in both mitochondria and nucleus. The majority of early studies have shown neuroprotective effects of Sirt3 activation in various models of CNS injury. Recently, it was found that genetic loss of Sirt3 is beneficial in ischemia/reperfusion (I/R) injury. Therefore, this study was designed to explore the effects of both genetic and pharmacological inhibition of Sirt3 in a middle cerebral artery occlusion (MCAo) model of stroke. Methods: Focal cerebral ischemia was induced by transient right MCAo for 60min followed by 0, 6, 24 and 72 hrs of reperfusion. A 72hrs post ischemic injury time point was chosen to measure infarction in various treatment groups. The Sirt3 inhibitor AGK7 (sc- 204281 Santa cruz,) that selectively inhibits Sirt3 over Sirt1 and Sirt2, was given as single intraperitoneal injection (0.15, 0.5 and 1.5mg/kg) 3hrs after stroke onset. Activity or expression of Sirt3, was examined with Sirt3 activity kit or western blot using anti-Sirt3, anti-acetylated lysine antibodies. Results: Sirt3 knockout mice showed a significant reduction in hemispheric infarct volume compared to WT littermate controls (37.72±5.21 vs 52.8±6.76, p<0.05). In the pharmacological study, a dose of 0.5 mg/kg i.p of inhibitor showed significant reduction in Sirt3 activity and but had no neuroprotective effect. Furthermore, a much higher dose (1.5mg/kg i.p) did not show any additional inhibitory effect on sirt3 activity but unexpectedly increased infarct volume (51.8±6.87 vs. 62.56± 7.89, P<0.05) and hemorrhagic transformation. Expression studies showed no overall change in Sirt3 expression in whole cell lysates at 0, 6, 24 or 72 hrs after reperfusion; however the expression pattern and activity varied with time in different subcellular compartments. Summary and Conclusions: Changes in subcellular translocation and activity of Sirt3 after I/R stress suggests it important role in target protein deacetylation in stroke pathophysiology. Surprisingly, genetic deletion but not pharmacological inhibition led to neuroprotection, indicating the need to carefully examine target protein by both genetic and pharmacological approaches.

Download Full-text