Neurological Deficits In Rats Research Articles

Vitamin D receptor activation influences the ERK pathway and protects against neurological deficits and neuronal death.

Previous studies have demonstrated that global cerebral ischemia (GCI) causes neurological deficits and neuronal cell apoptosis. Calcitriol, a biologically active metabolite of vitamin D, exerts its endocrinological influence via nuclear vitamin D receptor. It is being assessed as an emerging therapeutic strategy in models of various medical conditions, including acute brain injury. The purpose of the present study was to investigate the neuroprotective effects of calcitriol on GCI and further refine the potential underlying mechanisms. A total of 145 male rats were assigned to 5 groups as follows: Sham group, GCI group, calcitriol treatment group, PD98059 treatment group and vehicle-treated group. Brain water content and neurologic severity score were assessed to evaluate the brain edema and neurological deficits of rats. Histopathological changes and ultrastructures of cells were observed via hematoxylin and eosin stain and transmission electron microscopy, respectively. Immunofluorescent staining and western blot analysis were used to assess the expression of proteins and their co-localization at the molecular level. The results demonstrated that post-GCI administration of calcitriol attenuated brain edema and improved neurological function in rats. Calcitriol also caused marked extracellular signal-regulated kinase 1/2 pathway activation, and thereby attenuated neuronal apoptosis. The present study provided novel clues for understanding the mechanisms by which calcitriol exerts its neuroprotective activity in a rat model of GCI.

The protective role of verbenalin in rat model of focal cerebral ischemia reperfusion.

To investigate the protective mechanism of verbenalin on cerebral ischemia-reperfusion injury. Middle cerebral artery occlusion in the left hemisphere was induced in rats by filament insertion, and rat model of focal cerebral ischemia-reperfusion was established. The high, medium and low dose of verbenalin groups were injected in the tail vein of corresponding drugs 10 min before reperfusion, and submitted for 22 h of reperfusion after the operation. Mortality rate was then calculated, and neurological deficits of rats were scored. The serum of rats was got to determine the S-100β protein level, and the brain tissue was removed to determine the levels of Bax, Bcl-2, Caspase-3 and ATPase. TTC staining was performed on the brain tissue to calculate the percentage of cerebral infarct size. Changes in brain tissue morphology were observed. Rat model of focal cerebral ischemia-reperfusion was successfully replicated. In groups that have taken different doses of verbenalin, the mortality rate, neurological deficit score and the percentage of cerebral infarction size were significantly reduced, and the levels of Bax, Caspase-3, S-100β level of the serum in the brain tissue were also significantly reduced. Increases in the levels of Bcl-2 and ATPase in brain tissue and improvement of pathological damage of hippocampus and cortex were observed. Verbenalin can inhibit the expression of apoptosis genes, promote the expression of anti-apoptosis genes, improve brain microcirculation and energy metabolism, hence reducing cerebral ischemia-reperfusion injury.

In situ hydrogels enhancing postoperative functional recovery by reducing iron overload after intracerebral haemorrhage

The role of surgery for most patients with spontaneous intracerebral haemorrhage (ICH) remains controversial due to the continuous occurrence of postoperative iron overload induced by low clot clearance rate. In this study, human hair keratose hydrogel (KG) loading with minocycline hydrochloride (MH) were prepared to reduce iron overload for the improvement of the postoperative functional recovery after ICH aspiration surgery. Hemoglobin-induced iron accumulation in rat primary neuronal culture was delayed by the adsorptive capacity of blank KG, while MH-loaded KG displayed a stronger and more thorough cytoprotective effect than blank KG due to the combined effect of absorptive action to iron and sustained release of the iron chelator. Moreover, high iron-chelating efficiency in the hematoma region supplied by MH-loaded KG significantly reduced dose strength of iron chelator. In situ injection of KG with different MH loadings (2, 20, and 200μg) into the hematoma region after aspiration surgery showed a stronger effect on the reduction of ICH-induced iron accumulation, edema, and neurological deficits in rats compared to the postoperative intraperitoneal administration of MH (approximately 15mg). These results suggested that the in situ KG not only could effectively reduce the ICH postoperative iron overload and improve the postoperative functional recovery via the iron adsorption and sustained release of MH, but also has great potential to reduce the systemic adverse effects by decreasing the dose strength of iron chelator.

Balasubramide derivative 3C modulates microglia activation via CaMKKβ-dependent AMPK/PGC-1α pathway in neuroinflammatory conditions

Neuroinflammation plays a vital role in the pathological process of cerebral ischemic stroke, but currently there is no effective treatment. After ischemia, microglia-produced proinflammatory mediator expression contributes to the aggravation of neuroinflammation, while anti-inflammatory activation of microglia develops an anti-neuroinflammatory effect via secretion of anti-inflammatory factor. Promoting the anti-inflammatory activation of microglia might be an effective treatment of stroke. Previously, we discovered one derivative of the natural product (+)-balasubramide, compound 3C, that exhibits a remarkably anti-neuroinflammatory effect in vitro with unknown mechanisms. Thus in this study, we aimed to clarify its molecular mechanisms and determine whether compound 3C has a neuroprotective effect after ischemia via regulation on microglial inflammation. We found that compound 3C promoted the anti-inflammatory mediator expression and reduced the proinflammatory mediator expression in LPS-stimulated BV2 cells and mouse primary microglia cells, which were reversed by AMP-activated protein kinase (AMPK) inhibition or AMPK upstream calmodulin-dependent protein kinase kinase beta (CaMKKβ) inhibition. Compound 3C also prevented LPS-stimulated JNK activation and enhanced PGC-1α activation in microglia, which was attenuated by AMPK inhibition. Additionally, compound 3C ameliorated depressive behaviors in LPS-induced neuroinflammatory mice by promoting the anti-inflammatory activation of microglia. Furthermore, we found that compound 3C markedly reduced brain infarct volume, improved the neurological deficit in rats with ischemia and reduced the activated microglia/macrophage cells in the ischemic area, which concomitantly enhanced the anti-inflammatory mediator expression. A mechanistic study showed that the compound 3C-mediated activation of CaMKKβ, AMPK and PGC-1α is involved in the anti-neuroinflammatory and neuroprotective effects of 3C in the brain of LPS-treated mice and ischemic rats. Taken together, our results show that compound 3C could suppress neuroinflammation in vitro and in vivo by modulating microglial activation state through the CaMKKβ-dependent AMPK/PGC-1α signaling pathway, and maybe further be developed as a promising new drug candidate for the treatment of brain disorders such as stroke associated with brain inflammation.

Anti-high mobility group box-1 (HMGB1) antibody inhibits hemorrhage-induced brain injury and improved neurological deficits in rats

As one of the most lethal stroke subtypes, intracerebral hemorrhage (ICH) is acknowledged as a serious clinical problem lacking effective treatment. Available evidence from preclinical and clinical studies suggests that inflammatory mechanisms are involved in the progression of ICH-induced secondary brain injury. High mobility group box-1 (HMGB1) is a ubiquitous and abundant nonhistone DNA-binding protein, and is also an important proinflammatory molecule once released into the extracellular space from the nuclei. Here, we show that treatment with neutralizing anti-HMGB1 mAb (1 mg/kg, i.v. twice) remarkably ameliorated ICH-injury induced by local injection of collagenase IV in the striatum of rats. Administration of anti-HMGB1 mAb inhibited the release of HMGB1 into the extracellular space in the peri-hematomal region, reduced serum HMGB1 levels and decreased brain edema by protecting blood-brain barrier integrity, in association with decreased activated microglia and the expression of inflammation-related factors at 24 h after ICH. Consequently, anti-HMGB1 mAb reduced the oxidative stress and improved the behavioral performance of rats. These results strongly indicate that HMGB1 plays a critical role in the development of ICH-induced secondary injury through the amplification of plural inflammatory responses. Intravenous injection of neutralizing anti-HMGB1 mAb has potential as a novel therapeutic strategy for ICH.

Long-Term Kinetics of Immunologic Components and Neurological Deficits in Rats Following Repetitive Mild Traumatic Brain Injury.

BackgroundDespite growing awareness of repetitive mild traumatic brain injury (rmTBI), understanding of the involvement of long-term kinetics of immunologic components in the central and peripheral immune system took part remains incomplete. The present study aimed to provide a quantitative assay for certain immune system parameters in rmTBI rats.Material/MethodsNeurological functions were assessed by modified Neurological Severity Score (mNSS) and Morris Water Maze (MWM), immunologic components from brain and peripheral blood were analyzed by flow cytometry (FCM), and concentrations of inflammatory cytokines, including tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-10 were measure by enzyme-linked immunosorbent assay (ELISA).ResultsNeurological functions of rmTBI rats were seriously impaired. In the brain, T cells were up-regulated and peaked at week 1. The percentage of CD4+ T cells decreased from week 1 to week 4, while CD8+ T cells notably decreased at week 1, then increased until week 4. The infiltration proportion of Treg cells was reduced at week 1 and peaked at week 2. CD86+/CD11b+ M1 peaked at week 4 and CD206+/CD11b+ M2 rose at week 1. IL-6/IL-10 showed a similar pattern, whose rise corresponded to the decrease in TNF-α at week 2 after rmTBI. FCM demonstrated peripheral immune dysfunction after rmTBI.ConclusionsmNSS and MWM demonstrated neuronal deficits in rmTBI rats, and central and peripheral immune systems were implicated in the pathophysiological processes of rmTBI. Long-term immune response may play dual roles in injury and repair of rmTBI.

3'-Daidzein sulfonate sodium inhibits neuronal apoptosis induced by cerebral ischemia-reperfusion.

This study aimed to observe the effects of 3'-daidzein sulfonate sodium(DSS) on ischemia-reperfusion-induced brain injury and to analyze the mechanisms responsible for neuronal apoptosis. Focal ischemias were induced in male Sprague-Dawley rats using middle cerebral artery occlusion. The rats were divided into 5groups based on sham surgery or real occlusion, and treatment with different doses of DSS(0.5, 1.0and2.0mg/kg) or normal saline(model group), injected preoperatively into the rats with cerebral occlusion. After 2h of ischemia and 24h of reperfusion, neurological deficit scores were evaluated using the Longa grade point standard. The infarct volume was measured using a triphenyl tetrazolium chloride staining technique. Blood-brain barrier(BBB) permeability was measured using the Evansblue(EB) content of brain tissues, while electron microscopy was used to observe ultrastructural changes. The expression levels of Bcl-2, Bax and caspase-3 were detected by an immunohistochemical method and western blot analysis. The neurological deficit in rats pre-treated with DSS at all doses decreased significantly(P<0.05) in comparison with the model group, as did the cerebral infarct volume ratios. The brain EB content was significantly reduced by the injection of DSS. The ultrastructural integrity of the rat BBB was significantly preserved in the DSS-treated groups in comparison with the model group. This was concomitant with the reduced swelling of astrocytes and pericytes in the BBB. The immunohistochemistry results revealed that DSS significantly enhanced the expression of Bcl-2, and inhibited the expression of Bax and caspase-3 in the brain in comparison to the model group. The number of apoptotic cells in the groups treated with DSS was reduced in comparison with similar areas in the model group. These findings suggest that DSS within a dosage range of 0.5-2.0mg/kg provides significant protection from injury to the BBB induced by cerebral ischemia-reperfusion, as it exerts a neuroprotective effect by inhibiting apoptosis.

Levodopa improves learning and memory ability on global cerebral ischemia-reperfusion injured rats in the Morris water maze test

Previous studies have shown that levodopa (L-dopa) for 1–7days improved the consciousness level of certain patients who suffered from ischemia-reperfusion injury and were comatose for a long time period after cerebral resuscitation treatment. It also has an awakening effect on patients with disorders of consciousness. This study aimed to investigate whether L-dopa, which is used clinically to treat Parkinson's disease, might also ameliorate the behavior of rats following global cerebral ischemia-reperfusion injury. Fifty-six healthy adult male Sprague-Dawley rats were randomly divided into four groups: shamoperated, global cerebral ischemia mode, 25mg/kg/d L-dopa intervention, and 50mg/kg/d L-dopa intervention. The level of consciousness and modified neurological severity score (NSS) of the rats in each group were measured before reperfusion and 6, 24, and 72h and 1–4 weeks after reperfusion. The Morris water maze test was used to assess behavior of rats 1 week after reperfusion and 2 weeks after reperfusion in each group. The results showed that after global cerebral ischemiareperfusion injury, neurological deficits of rats are severe, and space exploration capacity and learning and memory capacity are significantly decreased. L-dopa can shorten the duration of coma in rats following global cerebral ischemia-reperfusion injury and improve the symptoms of neurological deficits and advanced learning and memory. In the range of the selected doses, the relationship between L-dopa and improvement of the neurological behavior in rats was not dose-dependent. Dopamine may be useful for treating severe ischemia-reperfusion brain injury.

Exercise Preconditioning Regulates the Toll-Like Receptor 4/Nuclear Factor-κB Signaling Pathway and Reduces Cerebral Ischemia/Reperfusion Inflammatory Injury: A Study in Rats

To explore the influence of exercise preconditioning (EP) on the activity of the toll-like receptor (TLR)4/nuclear factor (NF)-κB signaling pathway in a rat model of cerebral ischemia/reperfusion (I/R) inflammatory injury. Ischemia was induced in rats using transient middle cerebral artery occlusion (tMCAO) after 3 weeks of EP. Fifty-four rats were divided into sham, MCAO, and EP+MCAO groups. Following the induction of cerebral I/R injury, rats were scored for neurological deficits. Various techniques were used to evaluate ischemic infarct volume and explore pathological changes in tissue morphology after cerebral I/R injury, wherein the levels of TLR4 and NF-κB were analyzed. In addition, enzyme-linked immunosorbent assays were used to detect the levels of tumor necrosis factor (TNF)-α and interleukin (IL)-1β in peripheral serum. Twenty-four hours after cerebral I/R injury, the neurological deficit scores decreased and ischemic cortical damage alleviated in EP+MCAO group; the number of TLR4- and NF-κB-positive cells, the expression of TLR4 and NF-κB in the ischemic side, and the concentrations of TNF-α and IL-1β in the peripheral serum were lower in EP+MCAO group than those in the MCAO group (P <.05). The present study indicates that EP can improve cerebral I/R-induced neurological deficits in rats, reduce infarct volume, mitigate pathological damage in the ischemic cortex, and exert neuroprotective effects. The mechanism underlying these effects might involve the regulation of the TLR4/NF-κB signaling pathway and the inhibition of central and peripheral inflammatory cascades during cerebral I/R injury.

Effect of willed movement therapy on the expression of Nogo-A and Rho-associated kinase in rats of cerebral ischemia

Objective To determine the effect of willed movement on the expression of Nogo-A and Rho-associated kinase (ROCK) in adult rats with cerebral ischemia. Methods Cerebral ischemia/reperfusion injury was established by middle cerebral artery occlusion (MCAO) for 2 h, followed by a 24 h reperfusion in 54 adult rats and the degree of their neurological deficit was evaluated using Longa scale. They were then divided randomly into 3 groups, namely the MCAO group, the environmental modification (EM) group, and the willed movement (WM) group. The rats of MCAO group were raised in a regular breeding box, where they could get food and water freely. Meanwhile, those of the other two groups were raised in a homemade box. For the WM group, the water bottle and food were located on the roof of the homemade box. In each group, six rats were killed on day 3, 7 and 15 after reperfusion and their neurological deficits were evaluated respectively. Immunohistochemistry assay was employed to examine the expression of Nogo-A and ROCK in the brain tissue around the ischemic foci. Results The rats of the WM group showed lessened neurological deficits on day 15 compared with the model and EM group. Their expression of Nogo-A decreases from(28.92±2.17)/hpf on day 7 to (24.38±2.29)/hpf on day 15 and that of ROCK did from (40.03±2.14)/hpf to (38.08±2.07)/ hpf, lower than those of the model and EM group. However, no significant differences were found in the expression of Nogo-A and ROCK between the model group and EM group at any time points. Conclusion Willed movement could promote the functional recovery of neurological deficits in rats with ischemia after reperfusion, which is probably in relation to restrained expression of Nogo-A and Rho-associated in the tissue around the brain ischemic foci. Key words: Willed movement; Cerebral ischemia; Nogo-A; Rho-associated kinase

Intra-carotid arterial administration of autologous peripheral blood-derived endothelial progenitor cells improves acute ischemic stroke neurological outcomes in rats

ObjectiveWe tested the hypothesis that transfusion of autologous peripheral blood-derived endothelial progenitor cells (PBDEPC) via the internal carotid artery could reduce brain-infarct zone (BIZ) and neurological deficit in rats following acute ischemic stroke (IS) induced by 50-min left middle cerebral artery occlusion. DesignAdult male Sprague–Dawley rats (n=60) were equally divided into group 1 [sham control (SC)], group 2 [SC-PBDEPC (5.7×106/kg)], group 3 (IS), group 4 [IS-low-dose PBDEPC (1.7×106/kg)], group 5 [IS-high-dose PBDEPC (5.7×106/kg)]. Groups 2 to 5 received G-CSF (35μg/kg subcutaneously) for 4days before drawing blood for PBDEPC culture. Measurements and main resultsBy day 90, BIZ determined by histopathology (area) and brain MRI (volume) were highest in group 3, lowest in groups 1 and 2, higher in group 4 than in group 5 (all p<0.0001), and not significantly different between groups 1 and 2. Sensorimotor functional results exhibited an opposite pattern of BIZ among groups 3 to 5 (p<0.005). Angiogenesis biomarkers (SDF-1α, CXCR4, VEGF, angiopoietin-1) significantly increased progressively from groups 1 and 2 to group 5 (all p<0.0001). Oxidative-stress (NOX-1, NOX-2, oxidized protein), apoptotic (cleaved caspase 3 and PARP, mitochondrial Bax), inflammatory (MMP-9, TNF-α, AQP-4, GFAP, iNOS), and brain-damaged (cytosolic cytochrome-C) biomarkers showed an identical pattern, whereas anti-inflammatory (Bcl-2), mitochondrial preservation (mitochondrial cytochrome-C, PGC-1α), and endothelial function (CD31+, vWF+, eNOS) biomarkers, and vessel density showed an opposite pattern of BIZ among these five groups (all p<0.001). ConclusionHigher-dose was superior to lower-dose EPC treatment for reducing BIZ and improving neurological functional outcome.

Ginsenoside Rb1 inhibits neuronal apoptosis and damage, enhances spinal aquaporin 4 expression and improves neurological deficits in rats with spinal cord ischemia‑reperfusion injury.

Ginsenoside Rb1 is a potential therapeutic agent for the treatment of spinal cord ischemia‑reperfusion injury (SCII), although it has not yet been investigated in depth. The aim of the present study was to investigate the effects of ginsenoside Rb1 treatment on SCII and aquaporin‑4 (AQP4) expression in the rat spinal cord. Experimental animals were subjected to one of four conditions, including the blank control condition, sham procedure, spinal cord ischemia‑reperfusion induced by abdominal aortic occlusion or spinal cord ischemia‑reperfusion followed by ginsenoside Rb1 treatment. Locomotor activity was evaluated using the Basso Beattie Bresnahan scale. Spinal cord damage was assessed with hematoxylin and eosin and Nissl staining and the apoptotic rate was measured using terminal deoxynucleotidyl transferase dUTP nick end labeling. AQP4 expression was assessed by immunohistochemical analysis, western blotting and reverse transcription‑quantitative polymerase chain reaction. Abdominal aortic occlusion resulted in the reduced expression of AQP4 in the spinal cord, which gradually recovered over time. Furthermore, ginsenoside Rb1 treatment significantly attenuated this decrease and protected the integrity of and reduced the apoptotic rate in spinal cord neurons. Treatment with ginsenoside Rb1 attenuated the initial downregulation and advanced the recovery of AQP4 expression levels, suggesting a possible mechanism for the therapeutic effects on SCII.

Changes of peripheral-type benzodiazepine receptors in the penumbra area after cerebral ischemia-reperfusion injury and effects of astragaloside IV on rats.

This study investigated the changes in peripheral benzodiazepine receptors (PBRs) in the penumbra after cerebral ischemia-reperfusion injury, and examined the effects of astragaloside IV (AST) on PBRs in rats. Sixty Sprague-Dawley rats were divided into a sham operation group, a model group, and three AST treatment groups. Cerebral ischemic models were induced by the clue-blocked method. Neurological deficits were examined. The animals were sacrificed after 2 h of ischemia and 24 h of reperfusion, and mitochondria from the penumbra were purified. PBR density (Bmax) and affinity were measured by radioligand assays. Mitochondrial [(3)H]PK11195 binding was correlated with neurological deficits in rats. Compared to the model group, the 10 mg/kg AST group, 40 mg/kg AST group, and 100 mg/kg AST group had fewer neurological deficits. The effects in the 40 mg/ kg group did not significantly differ from the effects in the 100 mg/ kg group. Compared to the model group, the 10 mg/kg AST group, 40 mg/kg group, and 100 mg/kg group had a decreased Bmax in the penumbra. The Bmax decreased in the 40 mg/kg AST group and in the 100 mg/kg AST group compared with the 10 mg/kg group. The Bmax and neurological deficits in the 40 mg/kg did not significantly differ from those in the 100 mg/kg group. By contrast, the AST-treated rats showed no significant changes in the binding parameter equilibrium dissociation constant compared with those in the sham operation group and the model group. AST protects ischemic brain tissue by inhibiting PBR expression after cerebral ischemia.

Studies on the active constituents in radix salviae miltiorrhizae and their protective effects on cerebral ischemia reperfusion injury and its mechanism.

Background:To extract, purify and identify the active constituents in ethanol extract of Radix Salviae Miltiorrhizae, and to analyze the protective effects of tanshinone IIA on cerebral ischemia-reperfusion injury in rats.Materials and Methods:Radix Salviae Miltiorrhizae was extracted by ultrasonic extraction, effective parts were extracted by extraction method, compounds were isolated by preparative TLC and preparative HPLC, and structures of compounds were identified by 1H NMR and 13C NMR; the effects of tanshinone IIA on cerebral ischemia-reperfusion injury in rats were determined by establishing rat model of middle cerebral artery occlusion (MCAO).Results:The experimental data show four compounds were isolated, namely tanshinone IIB, hydroxymethylene tanshinone, salvianolic acid B and 9”’-methyl lithospermate B. Tanshinone IIA could alleviate the symptoms of neurological deficit in rats, the neurological deficit alleviating effect became more obvious with the increase of dose; tanshinone IIA experimental groups could reduce the cerebral infarction size and brain water content in rats, different concentrations of tanshinone IIA could decrease the SOD content and increase the MDA content in the frontal and parietal cortices of ischemic hemisphere in the ischemia reperfusion group, the differences were statistically significant compared with the ischemia reperfusion group.Conclusion:Radix Salviae Miltiorrhizae has the protective effects on cerebral ischemia reperfusion injury in rats.

Evaluation of survival and neurological deficit in rats in the new model of global transient cerebral ischemia.

We propose a modification to rat model of transient global cerebral ischemia with four-vessel occlusion avoiding pneumothorax and minimizing the consequences of surgery. Survival and neurological deficit in rats in this model was studied over 5 days.

Umbilical Cord Blood-Derived CD34+ Cells Improve Outcomes of Traumatic Brain Injury in Rats by Stimulating Angiogenesis and Neurogenesis

Human umbilical cord blood cells (HUCBCs) have been shown to be beneficial in reducing neurological deficits in rats with brain fluid percussion injury (FPI). This study aimed to assess the basic mechanisms underlying the neuroprotective effects of HUCBC-derived cluster of differentiation 34-positive (CD34⁺) cells. Rats were divided into three major groups: (i) sham-operated controls; (ii) FPI rats treated with phosphate-buffered saline (PBS); (iii) FPI rats treated with 0.2%, 50%, or 95% CD34⁺ cells (in 5 × 10⁵ cord blood lymphocytes and monocytes). Intravenous (IV) administration of 0.3 ml of PBS, 0.2% CD34⁺ cells, 50% CD34⁺ cells, or 95% CD34⁺ cells was conducted immediately after FPI. It was found that 4 days post-FPI, CD34⁺ cells could be detected in the ischemic brain tissues for 50% CD34⁺ cell- or 95% CD34⁺ cell-treated FPI rats, but not for the PBS-treated FPI rats or the 0.2% CD34⁺ cell-treated FPI rats. CD34⁺ cell (0.2%)-treated FPI rats or PBS-treated FPI rats displayed neurological and motor deficits, cerebral contusion and apoptosis [e.g., increased numbers of both TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling)-positive cells and caspase-3-positive cells], and activated inflammation (e.g., increased serum levels of tumor necrosis factor-α). FPI-induced neurological motor dysfunction, cerebral contusion and apoptosis, and activated inflammation could be attenuated by 50% CD34⁺ or 95% CD34⁺ cell therapy. In addition 50% or 95% CD34⁺ cell therapy but not PBS or 0.2% CD34⁺ cell therapy significantly promoted angiogenesis (e.g., increased numbers of both vasculoendothelial growth factor-positive cells and 5-bromodeoxyuridine (BrdU)-endothelial double-positive cells), neurogenesis (e.g., increased numbers of both glial cell line-derived neurotrophic factor-positive cells and BrdU/neuronal nuclei double-positive cells) in the ischemic brain after FPI, and migration of endothelial progenitor cells from the bone marrow. Our data suggest that IV administration of HUCBC-derived CD34⁺ cells may improve outcomes of FPI in rats by stimulating both angiogenesis and neurogenesis.

Neuroprotective capabilities of TSA against cerebral ischemia/reperfusion injury via PI3K/Akt signaling pathway in rats

Background: 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. Methods: 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). Results: 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. Conclusions: 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.

Effects of Early and Late Ischemic Preconditioning of the Brain on the Severity of Hippocampal Neuron Injury and the Degree of Neurological Deficit in Rats

The aim of the present work was to investigate the neuroprotective effects of early and late ischemic preconditioning (IPreC) in the acute phase of ischemic brain damage in rats. Single 5-min ischemic episodes of early IPreC were found not to produce significant neuroprotective effects as compared with controls, while three 5-min episodes of early IPreC led to significant increases in neurological deficit and increases in the level of neuron injury in hippocampal field CA1. Conversely, late IPreC, consisting of a single 5-min episode 24 h before modeling test ischemia, produced a significant neuroprotective effect, with decreased neurological deficit and retention of hippocampal field CA1 neuron viability.

The angiotensin type 2 receptor agonist Compound 21 elicits cerebroprotection in endothelin-1 induced ischemic stroke

Evidence indicates that angiotensin II type 2 receptors (AT2R) exert cerebroprotective actions during stroke. A selective non-peptide AT2R agonist, Compound 21 (C21), has been shown to exert beneficial effects in models of cardiac and renal disease, as well as hemorrhagic stroke. Here, we hypothesize that C21 may exert beneficial effects against cerebral damage and neurological deficits produced by ischemic stroke. We determined the effects of central and peripheral administration of C21 on the cerebral damage and neurological deficits in rats elicited by endothelin-1 induced middle cerebral artery occlusion (MCAO), a model of cerebral ischemia. Rats infused centrally (intracerebroventricular) with C21 before endothelin-1 induced MCAO exhibited significant reductions in cerebral infarct size and the neurological deficits produced by cerebral ischemia. Similar cerebroprotection was obtained in rats injected systemically (intraperitoneal) with C21 either before or after endothelin-1 induced MCAO. The protective effects of C21 were reversed by central administration of an AT2R inhibitor, PD123319. While C21 did not alter cerebral blood flow at the doses used here, peripheral post-stroke administration of this agent significantly attenuated the MCAO-induced increases in inducible nitric oxide synthase, chemokine (C-C) motif ligand 2 and C-C chemokine receptor type 2 mRNAs in the cerebral cortex, indicating that the cerebroprotective action is associated with an anti-inflammatory effect. These results strengthen the view that AT2R agonists may have potential therapeutic value in ischemic stroke, and provide the first evidence of cerebroprotection induced by systemic post stroke administration of a selective AT2R agonist.

Intracarotid transplantation of autologous adipose-derived mesenchymal stem cells significantly improves neurological deficits in rats after MCAo

We aimed to evaluate whether adipose-derived mesenchymal stem cells (ADMSCs) that were transplanted via internal carotid can improve the neurological function after acute ischemic stroke and explore the underlying mechanisms. Total 40 adult Sprague-Dawley rats were subjected to transient (1.5 h) middle cerebral artery occlusion (MCAo) to induce ischemia/reperfusion injury. These rats were randomly divided into two groups with 20 ones in each group, which were intracarotid-injected with autologous ADMSCs (2.0 × 10(6)) and saline (control) at day 3 after MCAo, respectively. Behavioral tests (adhesive-removal and modified neurological severity score) were performed before and after MCAo. Histology was used to evaluate the ischemia lesion volume and pathological changes. The apoptosis and astroglial reactivity were determined by TUNEL and glial fibrillary acidic protein (GFAP) staining, respectively. Besides, we applied immunofluorescence to identify the distribution of ADMSCs and the neural makers (NeuN and GFAP) expressed by them under confocal microscope. Significant improvement of neurological deficits was observed in rats transplanted with ADMSCs when compared to controls. But there was no obvious difference on ischemia lesion volume between these two groups. The injected ADMSCs migrated to the brain infarct region and mainly localized in the ischemic core and boundary zone of the lesion, which can express NeuN and GFAP in the brain. In addition, autologous transplantation of ADMSCs significantly attenuated astroglial reactivity, inhibited cellular apoptosis and promoted cellular proliferation. Our data indicated that intracarotid transplantation of autologous ADMSCs had the potential therapeutic application for ischemic stroke.