Erythropoietin-derived peptide ARA290 mediates brain tissue protection through the ß-common receptor in mice with cerebral ischemic stroke.

AIM: To explore the neuroprotective effects of ARA290 and the role of ß-common receptor (ßCR) in a mouse model of middle cerebral artery occlusion (MCAO). METHODS: This study included male C57BL/6J mice that underwent MCAO and reperfusion. The neuroprotective effect of ARA290 on MCAO-induced brain injury was investigated using neurological function tests (Longa and modified neurological severity score). Cerebral infarction was examined by 2, 3, 5-triphenyl tetrazolium chloride staining, neuronal apoptosis was assessed by immunofluorescence staining, blood parameters were measured using a flow cytometry-based automated hematology analyzer, liquid chromatography with tandem mass spectrometry was used to identify the serum metabolomics signature, inflammatory cytokines and liver index were detected by commercially available kits, and the protein levels of the erythropoietin (EPO) receptor and ßCR were measured by western blot. RESULTS: ARA290 exerted a qualitatively similar neuroprotective effect after MCAO as EPO. ARA290 significantly reduced neuronal apoptosis and the level of inflammatory cytokines in the brain tissue. However, ARA290's neuroprotective effect was significantly suppressed following the injection of siRNA against ßCR. CONCLUSION: ARA290 provided a neuroprotective effect via ßCR in cerebral ischemic mice without causing erythropoiesis. This study provides novel insights into the role of ARA290 in ischemic stroke intervention.

CCA repair or ECA ligation-Which middle cerebral artery occlusion is better in the reperfusion mouse model?

A reliable animal model is essential for ischemic stroke research. The implications of the external carotid artery (ECA) transection or common carotid artery (CCA) ligation have been described. Thus, a modified animal model, the CCA-repair model, has been established, and studies have shown that the CCA-repair model has potential advantages over the CCA-ligation model. However, whether the CCA-repair model is superior to the ECA-ligation model remains unclear. Sixty male C57BL/6 mice were randomly assigned to establish the CCA-repair (n = 34) or ECA-ligation (n = 26) models. Cerebral blood flow before middle cerebral artery occlusion (MCAO), immediately after MCAO and reperfusion were monitored and the operation duration, postoperative body weight, and food intake within 7 days, and the number of intraoperative and postoperative deaths within 7 days were recorded in the two models. Modified neurological severity scores and Bederson (0-5) scores were used to evaluate postoperative neurological function deficits on Days 1/3/5/7. 2,3,5-Triphenyltetrazolium chloride staining was used to quantify lesion volume on Day 7 after the operation. We found the establishment of the CCA-repair model required a longer total operation duration (p = 0.0175), especially the operation duration of reperfusion (p < 0.0001). However, there was no significant difference in body weight and food intake development, lesion volume and intragroup variability, neurological function deficits, mortality, and survival probability between the two groups. The CCA-repair model has no significant advantage over the ECA-ligation model. The ECA-ligation model is still a better choice for focal cerebral ischemia.

Erythropoietin promotes the differentiation of fetal neural stem cells into glial cells via the erythropoietin receptor-ß common receptor/Syne-1/H3K9me3 pathway.

AIMS: To investigate the effect of erythropoietin (EPO) on the differentiation of neural stem cells (NSCs)/neural progenitors (NPs) in the treatment of hypoxic-ischemic injury and its potential mechanisms. METHODS: Fetal NSCs/NPs were treated with EPO after oxygen and glucose deprivation/reoxygenation (OGD/R). Cell viability, proliferation, and differentiation of NSCs/NPs were detected by CellTiter-Glo, Edu assay, flow cytometry, and quantitative real-time PCR (qPCR). Immunofluorescence staining, co-immunoprecipitation (Co-IP), and western blotting were used to test the existence of EPO receptor/ß common receptor (EPOR/ßCR) heterodimer on NSCs/NPs and the possible pathway. RESULTS: EPO treatment at different time points increased cell viability without affecting proliferation. EPO treatment immediately after OGD/R promoted oligodendrocyte and astrocyte differentiation, while decreasing neuronal differentiation of NSCs/NPs. EPOR/ßCR heterodimer existed on the cell surface of the fetal cortical NSCs/NPs, EPO treatment significantly increased the mRNA expression of ßCR and elevated the correlation between EPOR and ßCR levels. In addition, mass spectrometry analysis identified Syne-1 as a downstream signaling molecule of the EPOR/ßCR heterodimer. Immunofluorescence staining and western blotting indicated that the ßCR/Syne-1/H3K9me3 pathway was possibly involved in the differentiation of fetal neural stem cells into the glial cell effect of EPO. CONCLUSION: EPO treatment immediately after OGD/R could not facilitate fetal NSCs/NPs neurogenesis but promoted the formation of the EPOR/ßCR heterodimer on fetal NSCs/NPs, which mediates its function in glial differentiation.

The effects of erythropoietin on neurogenesis after ischemic stroke.

Erythropoietin has been researched for its neuroprotective effects in ischemic stroke for over 30 years. Although erythropoietin can cause side effects that need to be controlled, it has been suggested to be effective in enhancing the prognosis of patients who are out of the therapeutic time window and have not received recombinant tissue plasminogen activator therapy. Studies on the mechanism of the function of erythropoietin have shown that it has various protective effects in ischemic brain injury after stroke, including promoting neurogenesis. In this review, we discuss the effects of erythropoietin on neurogenesis after ischemic brain injury and provide references for effective treatments for ischemic stroke, which is one of the leading causes of death worldwide.

The Chinese herb Fructus Broussonetiae aids learning and memory in chronic cerebral hypoperfusion by reducing proinflammatory microglia activation in rats.

The neuroprotective role of Fructus Broussonetiae in a model of chronic cerebral hypoperfusion with cognitive decline was focused on neural plasticity and microglia/macrophage polarization. Chronic cerebral hypoperfusion was induced by bilateral common carotid artery ligation. Fructus Broussonetiae shortened escape latency and added the number of platform crossings of rats, up-regulated the expression of synaptophysin in the gray matter and increased myelin basic protein expression in the white matter. Further mechanistic experiments were conducted to examine microglia activation and M1/M2 polarization. It was shown that Fructus Broussonetiae reduced the activation of microglia revealed by decreased expression of ionized calcium-binding adapter molecule-1, inhibited M1 polarization of microglia and improved microglial M2 polarization shown by down-regulated the expression of inducible nitric oxide synthase and Fc fragment of IgG receptor IIIa and up-regulated the expression of arginase-1. In conclusion, the Chinese herb Fructus Broussonetiae can improve cognitive function following chronic cerebral hypoperfusion by down-regulating the activation of microglia, inhibiting microglial M1 polarization, and improving neural plasticity.

Potential microglia-based interventions for stroke.

A large number of families worldwide suffer from the physical and mental burden posed by stroke. An increasing number of studies aimed at the prevention and treatment of stroke have been conducted. Specifically, manipulating the immune response to stroke is under intense investigation. Microglia are the principal immune cells in the brain and are the first line of defense against the pathophysiology induced by stroke. Increasing evidence has suggested that microglia play diverse roles that depend on dynamic interactions with neurons, astrocytes, and other neighboring cells both in the normal brain and under pathological conditions, including stroke. Moreover, there are dynamic alterations in microglial functions with respect to aging and sex differences in the human brain, which offer a deep understanding of the conditions of stroke patients of different ages and sex. Hence, we review the dynamic microglial reactions caused by aging, sex, and crosstalk with neighboring cells both in normal conditions and after stroke and relevant potential interventions.

Pathological Observation of Blood Stasis Syndrome in Non-diabetic Peripheral Neuropathies: A Retrospective Analysis Based on Nerve Biopsy.

OBJECTIVE: To investigate the pathological features of blood stasis syndrome (BSS) in non-diabetic peripheral neuropathy. METHODS: Clinical data of 31 patients with non-diabetic peripheral neuropathy who had undergone nerve biopsy during December 2004 and December 2010 in Xuanwu Hospital Capital Medical University were retrospectively analyzed. According to Chinese medicine (CM) syndrome differentiation and signs, 26 patients were blood stasis type and 5 patients were non-blood stasis type. Clinical and pathological data were compared in detail. RESULTS: Clinically, although both groups shared similar symptoms of limb numbness, weakness and sensory disturbances, the prevalence of neuralgia was much grievous in BSS group (73.1%, 26/31) compared with the non-BSS group (0%, 0/5). As for signs, dermal nutrients disturbance (84.6%, 22/26), dark or purple tongue (100.0%, 26/26), and sublingual varices (80.7%, 21/26) were more common in the BSS group than the non-BSS group (0%, 60%, 20%, respectively). The prevalence of qi deficiency cases (19/26) in the BSS group was significantly higher compared with the non-BSS group (1/5). The unique histological manifestations of BSS were axonal degeneration (16/26 vs 2/5 in non-BSS group), which was the hallmark of ischemia. Cases with BSS had prominent microangiopathy (61.5%, 16/26), manifested as epineurium vasculitis (inflammatory cell infiltrated to the vessel wall, obliteration and recanalization, vascular proliferation, extravascular hemosiderin deposition), angiotelectasis, proliferation and hyaline degeneration of endoneurium capillary. In the BSS group, impaired blood-nerve barrier was indicated by sub-perineurial edema (46.2%, 11/26) and endoneurial edema (15.4%, 4/26). The Renaut body (15.4%, 4/26) and amyloid deposition (3.8%, 1/26) found in the BSS group were absent in the non-BSS group. CONCLUSIONS: BBS was common in non-diabetic peripheral neuropathies. The nerves exhibited ischemic alteration of primary axon degeneration and secondary demyelination. The interstitial tissue revealed microcirculation impairment, blood-nerve barrier disturbance, amyloid deposition and proliferation changes. The high prevalence of qi deficiency also highlights the therapy of promotion of blood circulation and removal of blood stasis.

Huoluo Yinao decoction mitigates cognitive impairments after chronic cerebral hypoperfusion in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Huoluo Yinao decoction (HLYND) has been used to ameliorate cognitive impairment induced by chronic cerebral hypoperfusion in clinical for years. However, the exact mechanisms remain unknown. AIM OF THE STUDY: To investigate the effects and mechanisms underlying HLYND-mediated improvement in cognitive deficits associated with chronic cerebral hypoperfusion. MATERIALS AND METHODS: Thirty-six Sprague-Dawley rats were randomly allocated to three groups: sham, model, and HLYND. Daily administration of HLYND or volume-matched vehicle by gavage was initiated 1 day after bilateral carotid artery stenosis (BCAS) and continued for 42 days. The Morris water maze (MWM) test was used to assess cognitive functions from days 36-42. Via western blot and immunofluorescent staining, restoration of neuronal plasticity and remyelination of white matter were evaluated by analyzing the expression profiles of MAP-2, synaptophysin and MBP. In addition, macrophage/microglial activation was assessed by quantifying changes in Iba1, and macrophage/microglial polarization was assessed by changes in iNOS and CD16 (M1 markers), as well as Arg1 and CD206 (M2 markers). RESULTS: In the MWM test, BCAS rats showed significantly extended escape latency and reduced platform crossing times, while those in the HLYND group had shortened escape latency and increased frequency of platform crossing. In addition, rats in the model group showed decreased levels and abnormal morphological changes of MAP-2, synaptophysin and MBP, whereas HLYND administration reversed these effects. As expected, Iba1 levels were elevated in both the model and HLYND groups but rats in the model group showed increased levels of the M1 markers, iNOS and CD16, and a correspondent decrease in the M2 marker, Arg1. In contrast, in the HLYND group, iNOS and CD16 levels were suppressed, while Arg1 levels were elevated. CONCLUSIONS: Our findings demonstrate that HLYND mitigates cognitive impairment after chronic cerebral hypoperfusion in rats through mechanisms involving increased neuronal plasticity and white matter remyelination, with a subtile modulation of macrophage/microglial polarization toward the M2 phenotype.

MEPO promotes neurogenesis and angiogenesis but suppresses gliogenesis in mice with acute ischemic stroke.

Previously study has proved the non-erythropoietic mutant erythropoietin (MEPO) exerted neuroprotective effects against ischemic cerebral injury, with an efficacy similar to that of wild-type EPO. This study investigates its effects on neurogenesis, angiogenesis, and gliogenesis in cerebral ischemic mice. Male C57BL/6 mice were subjected to middle cerebral artery occlusion (MCAO) and reperfusion. EPO (5000 U/kg), MEPO (5000 U/kg) or equal volume of normal saline was injected intraperitoneally. Neurological function was evaluated by Rota-rod test, Neurological severity scores (NSS) and Adhesive removal test. After ischemia and reperfusion (I/R), the survival rate, brain tissue loss, neurogenesis, angiogenesis and gliogenesis were detected by Nissl staining, Immunofluorescence and Western blot, respectively. The results shown that MEPO significantly increased survival rate, reduced brain tissue loss, and improved neurological function after MCAO (P < 0.05). Furthermore, MEPO obviously enhanced the proliferation of neuronal precursors (DCX) and promoted its differentiation into mature neurons (NeuN) (P < 0.05). In addition, compared to normal saline treatment mice, MEPO increased the number of BrdU-positive cells in the cerebral vasculature (P < 0.05). Whereas, MEPO treatment also reduced the numbers of newly generated astrocytes (GFAP) and microglia (Iba1) (P < 0.05). Among all the tests in this study, there was no significant difference between EPO group and MEPO group. Taken together, MEPO promoted the regeneration of neurons and blood vessels in peripheral area of infarction, and suppressed the gliogenesis, thus promoting neurogenesis, improving neurological function and survival rate. Our findings suggest that the MEPO may be a therapeutic drug for ischemic stroke intervention.

Unique MicroRNAs Signature of Lymphocyte of Yang and Yin Syndromes in Acute Ischemic Stroke Patients.

OBJECTIVE: To identify the differentially expressed microRNAs (miRNAs) profiles of yang and yin syndromes in patients with acute ischemic stroke, and to provide the molecular basis of the classification of these two syndrome types in acute ischemic stroke patients. METHODS: A microarray assay was performed to assess the expression pattern of miRNAs in the lymphocyte of acute ischemic stroke patients. Target genes for the deregulated miRNAs were predicated using the online bioinformatic algorithms and functional annotation via Kyoto encyclopedia of genes and genomes pathway analysis for miRNAs predicted targets was carried out. Based on the predicted target genes of differentially expressed miRNAs, the miRNA-gene-network and miRNA-pathway-network were constructed. RESULTS: Yang score based on tongue texture, urine, dejecta, and appearance, etc. showed that clinical symptoms were distinct between yang and yin syndromes. There were significantly higher total leukocyte number and lower total protein level in patients with yang syndrome compared with those in patients with yin syndrome (P<0.05). Comprehensive miRNA analysis identified 36 unique down-regulated miRNAs in yang syndrome group, and 20 unique down-regulated and 2 unique up-regulated miRNAs in yin syndrome group. The key regulatory miRNAs, gene, and pathways in the yang syndrome were hsa-miR-93-5p and -320b, enabled homolog, the metabolic pathways and mitogen-activated protein kinase signaling pathways, respectively, while those in the yin syndrome were hsa-miR-424-5p and -106b-5p, CNOT4, hepatitis B and pathways in cancer, respectively. CONCLUSION: These results offered insight into the molecular basis underlying the different pathogenesis of yang or yin syndrome, providing clues for the individualized therapeutic strategies of acute ischemic stroke.

Brain-selective mild hypothermia promotes long-term white matter integrity after ischemic stroke in mice.

INTRODUCTION: The neuroprotective effects of hypothermia in acute ischemic stroke are well documented. However, the mechanisms involved in the effects remain to be clearly elucidated and the role of hypothermia on long-term white matter integrity after acute ischemic stroke has yet to be investigated. AIMS: To investigate the role of mild focal hypothermia on long-term white matter (WM) integrity after transient cerebral ischemia. RESULTS: Mild focal hypothermia treatment immediately after ischemic stroke significantly promotes WM integrity 28 days after the occlusion of the middle cerebral artery (MCAO) in mice. Higher integrity of white matter, lower activation of total microglia, less infarct volume, and better neurobehavioral function were detected in hypothermia-treated mice compared to normothermia-treated mice. Furthermore, we found that hypothermia could decrease detrimental M1 phenotype microglia and promote healthy M2 phenotype microglia. In vitro, results also indicated that hypothermia promoted oligodendrocytes differentiation and maturation after oxygen glucose deprivation. CONCLUSION: Hypothermia promotes long-term WM integrity and inhibits neuroinflammation in a mouse model of ischemic brain injury.

Normobaric oxygen treatment in acute ischemic stroke: a clinical perspective.

Acute ischemic stroke is a common and serious neurological disease. Oxygen therapy has been shown to increase oxygen supply to ischemic tissues and improve outcomes after cerebral ischemia/reperfusion. Normobaric hyperoxia (NBO), an easily applicable and non-invasive method, shows protective effects on acute ischemic stroke animals and patients in pilot studies. However, many critical scientific questions are still unclear, such as the therapeutic time window of NBO, the long-term effects and the benefits of NBO in large clinic trials. In this article, we review the current literatures on NBO treatment of acute ischemic stroke in preclinical and clinical studies and try to analyze and identify the key gaps or unknowns in our understanding about NBO. Based on these analyses, we provide suggestions for future studies.

Luoyutong Treatment Promotes Functional Recovery and Neuronal Plasticity after Cerebral Ischemia-Reperfusion Injury in Rats.

Luoyutong (LYT) capsule has been used to treat cerebrovascular diseases clinically in China and is now patented and approved by the State Food and Drug Administration. In this retrospective validation study we investigated the ability of LYT to protect against cerebral ischemia-reperfusion injury in rats. Cerebral ischemia-reperfusion injury was induced by middle cerebral artery occlusion followed by reperfusion. Capsule containing LYT (high dose and medium dose) as treatment group and Citicoline Sodium as positive control treatment group were administered daily to rats 30 min after reperfusion. Treatment was continued for either 3 days or 14 days. A saline solution was administered to control animals. Behavior tests were performed after 3 and 14 days of treatment. Our findings revealed that LYT treatment improved the neurological outcome, decreased cerebral infarction volume, and reduced apoptosis. Additionally, LYT improved neural plasticity, as the expression of synaptophysin, microtubule associated protein, and myelin basic protein was upregulated by LYT treatment, while neurofilament 200 expression was reduced. Moreover, levels of brain derived neurotrophic factor and basic fibroblast growth factor were increased. Our results suggest that LYT treatment may protect against ischemic injury and improve neural plasticity.

A pilot study on the correlation of tongue manifestation with the site of cerebral infarction in patients with stroke.

OBJECTIVE: To discuss the correlation of tongue manifestation with the site of cerebral infarction in patients with acute cerebral infarction. METHODS: From March 2008 to February 2009, 200 cases of hospitalized patients with first unilateral cerebral infarction were chosen in the Department of Neurology, Xuanwu Hospital. The correlation of different tongue color, fur texture, fur color with the site of cerebral infarction was analyzed. RESULTS: The site of cerebral infarction in patients were compared between different tongue color by Chisquare test (P=0.314), and further correspondence analysis demonstrated that there was correlation between red tongue and cortical-subcortical infarction group. The site of cerebral infarction in patients were compared between thick fur group and thin fur group, cortical-subcortical infarction occurred more frequently in the former (P=0.0008). The site of cerebral infarction in patients were compared between dry fur group, moist fur group and smooth fur group, correspondence analysis demonstrated there was correlation between dry fur and cortical-subcortical group. The site of cerebral infarction in the patients were compared between white fur group, white-yellow fur group and yellow fur group (P=0.010), and correspondence analysis demonstrated there was correlation between white fur and brainstem infarction; white-yellow fur has relationship with cortical infarction; subcortical infarction was weakly related with white-yellow fur; there was closer relationship between yellow fur and cortical-subcortical infarction. CONCLUSION: The change of tongue manifestation was associated with the site of cerebral infarction in patients, providing a new combining site for diagnosing cerebrovascular diseases by integrative medicine.

A pilot study on the relationship between tongue manifestation and the degree of neurological impairment in patients with acute cerebral infarction.

OBJECTIVE: To discuss the relationship between tongue manifestation and the degree of neurological impairment in the patients with acute cerebral infarction. METHODS: Two hundred patients with first unilateral cerebral infarction were recruited. The relationship between different tongue manifestation and National Institute of Health Stroke Scale (NIHSS) were analyzed. RESULTS: NIHSS scores in the patients from different tongue color groups were analyzed and further analysis demonstrated that the NIHSS score was higher in the patients with red or bluish-purple tongue than that of those with the pink (P <0.01). On tongue fur, the NIHSS score in the patients with thick fur was higher than that of those with the thin (P=0.003). NIHSS score in patients with slippery, moist or dry fur was significant different (P=0.003), Further analysis demonstrated that the NIHSS score was higher in the patients with dry fur than that of those with moist fur, and had statistical significance (P=0.01). The NIHSS score was higher in patients from greasy fur group than that of the non-greasy (P=0.002). There was significant difference of NHISS score in the patients with different fur color (P=0.000), and further analysis demonstrated that the NHISS score in white-yellow, yellow fur group were higher than that of the white (P=0.06 or 0.000). CONCLUSION: The changes of tongue manifestation might be associated with the degree of neurological impairment in the patients with acute cerebral infarction.

Study on the correlation of tongue manifestation with fibrinogen and neutrophil in acute cerebral infarction patients.

OBJECTIVE: To investigate the correlation of tongue manifestation with the fibrinogen level and the neutrophil count in blood of acute cerebral infarction patients. METHODS: A total of 200 patients with first unilateral cerebral infarction in Neurology Department of Xuanwu Hospital from March, 2008 to February, 2009 were recruited in this study. The correlation of the tongue fur color and texture with the blood fibrinogen level and the neutrophil count was analyzed in these patients. RESULTS: The level of fibrinogen and neutrophil count in thick fur group were significantly higher than that in thin fur group (P<0.05). There was no statistical difference in the level of fibrinogen and neutrophil count found between moist fur and dry fur. Statistical significance existed in the level of fibrinogen between the greasy tongue fur group and non-greasy tongue fur group (P<0.05). The level of fibrinogen and the neutrophil count were compared among different fur color groups, revealing that the level of fibrinogen in yellowish fur group was higher than that of white fur group and normal value with statistical significance (P<0.05) with neutrophil count in yellowish fur group being significantly higher than that in white fur group. CONCLUSION: Our results suggested that the change of tongue manifestation was associated with the level of fibrinogen and the neutrophil count in the blood of cerebral infarction patients.

AKT/GSK3ß-dependent autophagy contributes to the neuroprotection of limb remote ischemic postconditioning in the transient cerebral ischemic rat model.

BACKGROUND: Limb remote ischemic postconditioning (RIPostC) has been recognized as an applicable strategy in protecting against cerebral ischemic injury. However, the time window for application of limb RIPostC and the mechanisms behind RIPostC are still unclear. AIMS: In this study, we investigated the protective efficacy and the role of autophagy in limb RIPostC using a transient middle cerebral artery occlusion rat model. RESULTS: Limb RIPostC applied in the early phase of reperfusion reduced infarct size and improved neurological function. Autophagy levels in penumbral tissues were elevated in neurons of limb RIPostC rats, with an increase in the phosphorylation of AKT and glycogen synthase kinase 3ß (GSK3ß). Blocking the AKT/GSK3ß pathway via the AKT inhibitor LY294002 prior to limb RIPostC suppressed the RIPostC-induced autophagy and resulted in the activation of caspase-3 in RIPostC rats, suggesting a critical role for AKT/GSK3ß-dependent autophagy in reducing cell death after cerebral ischemia. CONCLUSIONS: These results aid optimization of the time window for RIPostC use and offer novel insight into, and a better understanding of, the protective mechanism of autophagy in limb RIPostC.

Ischemic postconditioning diminishes matrix metalloproteinase 9 expression and attenuates loss of the extracellular matrix proteins in rats following middle cerebral artery occlusion and reperfusion.

AIMS: Ischemic postconditioning (IPostC) has been proved to have neuroprotective effects for cerebral ischemia, but the underlying mechanism remains elusive. This study aimed at validating the neuroprotective effects of IPostC and investigating whether the neuroprotection of IPostC is associated with matrix metalloproteinase 9 (MMP9) and the extracellular matrix proteins, laminin and fibronectin, following cerebral ischemia/reperfusion in rats. METHODS: The rats in middle cerebral artery occlusion (MCAO) group underwent MCAO and reperfusion, and the animals in MCAO + IPostC group were treated by occluding bilateral common carotid arteries for 10 seconds and then reperfusing for 10 seconds for five episodes at the beginning of MCAO. Apoptosis was detected with terminal deoxynucleotidyl transferase dUTP nick end labeling staining. The expression of MMP9, laminin, and fibronectin was measured with immunofluorescence and enzyme-linked immunosorbent assay. RESULTS: IPostC reduced brain edema and infarct volume and improved the neurological function. Furthermore, IPostC decreased cell apoptosis compared with the MCAO group. Compared to the MCAO group, IPostC treatment reduced MMP9 expression. Moreover, the results showed that the expression of laminin and fibronectin significantly increased in the MCAO + IPostC group compared to the MCAO group. CONCLUSION: These findings indicated that diminishment of MMP9 expression and the attenuation of degradation of laminin and fibronectin may be involved in the protective mechanisms of postconditioning against cerebral ischemia/reperfusion injury.

Distribution of lysine-specific demethylase 1 in the brain of rat and its response in transient global cerebral ischemia.

The lysine-specific histone demethylase 1 (LSD1) is a chromatin modifying enzyme that specifically removes methyl groups from lysine 4 of histone 3 (H3-K4) and induces transcriptional repression. However, limited knowledge exists, regarding the existence and significance of LSD1 in the brain. We identified the distribution of LSD1 and H3-K4 mono-, di-, and tri-methylation in the brain of rats, respectively. The temporal and spatial distribution of LSD1 during ischemic brain injury was also explored. LSD1 immunoreactive cells were nucleus positive and were concentrated in the neurons of the hippocampus, cerebral cortex, striatum and amagdala. The distributions of H3-K4 mono-, di-, and tri-methylation exhibited exactly the same pattern as LSD1. LSD1 expression was induced both region and cell specifically after ischemic/perfusion, and complied with the two-peak mode of expression. These studies revealed a tightly regulated distribution for LSD1 in the brain of rats under ischemic insult, suggesting a critical role in neuron function.

[The effects of repetitive limb ischemia on the systemic concentration of NO, NOS in plasma of healthy humans].

AIM: To investigate the effects of RLI on plasma nitric oxide (NO) and NO synthase (NOS) isoforms of healthy humans. METHODS: 30 healthy human subjects (aged from 40 - 70 years old) were recruited. RLI was induced by five 5 min cycles of ischemia of non dominant arm (200 mmHg, 5 min interval). Blood pressure, heart rate, and the feelings of ischemic arm were continuously monitored. Venous plasma was collected in contralateral arm at Pre, Post-0 h, Post-4 h, and Post-24 h. Plasma level of NO was measured by Griess reaction, and NOS was measured by chemical method. RESULTS: Blood pressure and heart rate varied in normal range. The uncomfortable feeling was decreased with the increasing numbers of ischemic cycles. Plasma level of NO, and iNOS in plasma were significantly increased at Post-0 h, Post-4 h, and Post-24 h compared to Pre (P < 0.05). tNOS was also significantly increased at Post-0 h and Post-4 h compared to Pre (P < 0.05). No significant change in plasma cNOS was shown at following three time points than Pre. CONCLUSION: These findings suggest that RLI can elevate plasma level of NO, tNOS, and iNOS in healthy humans. RLI might be a safe method as a rIPC, and it would have important possibility to be performed in clinic.