Inhibiting HMGB1-RAGE axis prevents pro-inflammatory macrophages/microglia polarization and affords neuroprotection after spinal cord injury.

BACKGROUND: Spinal cord injury (SCI) favors a persistent pro-inflammatory macrophages/microglia-mediated response with only a transient appearance of anti-inflammatory phenotype of immune cells. However, the mechanisms controlling this special sterile inflammation after SCI are still not fully elucidated. It is known that damage-associated molecular patterns (DAMPs) released from necrotic cells after injury can trigger severe inflammation. High mobility group box 1(HMGB1), a ubiquitously expressed DNA binding protein, is an identified DAMP, and our previous study demonstrated that reactive astrocytes could undergo necroptosis and release HMGB1 after SCI in mice. The present study aimed to explore the effects and the possible mechanism of HMGB1on macrophages/microglia polarization, as well as the neuroprotective effects by HMGB1 inhibition after SCI. METHODS: In this study, the expression and the concentration of HMGB1 was determined by qRT-PCR, ELISA, and immunohistochemistry. Glycyrrhizin was applied to inhibit HMGB1, while FPS-ZM1 to suppress receptor for advanced glycation end products (RAGE). The polarization of macrophages/microglia in vitro and in vivo was detected by qRT-PCR, immunostaining, and western blot. The lesion area was detected by GFAP staining, while neuronal survival was examined by Nissl staining. Luxol fast blue (LFB) staining, DAB staining, and western blot were adopted to evaluate the myelin loss. Basso-Beattie-Bresnahan (BBB) scoring and rump-height Index (RHI) assay was applied to evaluate locomotor functional recovery. RESULTS: Our data showed that HMGB1 can be elevated and released from necroptotic astrocytes and HMGB1 could induce pro-inflammatory microglia through the RAGE-nuclear factor-kappa B (NF-κB) pathway. We further demonstrated that inhibiting HMGB1 or RAGE effectively decreased the numbers of detrimental pro-inflammatory macrophages/microglia while increased anti-inflammatory cells after SCI. Furthermore, our data showed that inhibiting HMGB1 or RAGE significantly decreased neuronal loss and demyelination, and improved functional recovery after SCI. CONCLUSIONS: The data implicated that HMGB1-RAGE axis contributed to the dominant pro-inflammatory macrophages/microglia-mediated pro-inflammatory response, and inhibiting this pathway afforded neuroprotection for SCI. Thus, therapies designed to modulate immune microenvironment based on this cascade might be a prospective treatment for SCI.

ONS resolution prediction based on Rasch model.

IoT (Internet of Things) involves a wide range of fields, and its application scenarios are complex and diverse. Failure of security defense in any link of IoT may lead to huge information leakage and immeasurable losses. IoT security problem is affecting and restricting its application prospect, and has become one of the hotspots in the field of IoT. ONS (Object Naming Service) is responsible for mapping function from EPC code information to URI (Uniform Resource Identifier). The security mechanism of ONS has been extensively studied by more and more scholars in recent years. The purpose of this paper is to apply Rasch, a famous psychological model, to ONS resolution security technology. Through observing the past resolution result, the ability of ONS resolution and the difficulty of EPC code can be calculated. With the difference between the ability of ONS resolution and the difficulty of EPC code, this model can predict the probability of the ONS future resolution to achieve the purpose of privacy protection in IoT addressing. Through simulation and Ministep software, the feasibility of the model is verified.

Puerarin Up-regulates Methyl-CpG Binding Protein 2 Phosphorylation in Hippocampus of Vascular Dementia Rats.

OBJECTIVE: To observe the effect of puerarin on methyl-CpG binding protein 2 (MeCP2) phosphorylation (pMeCP2) in the hippocampus of a rat model of vascular dementia (VD). METHODS: Thirty-six healthy Sprague-Dawley rats were randomly assigned to the sham-operated group, dementia group and puerarintreated group using a random number table (n=12 per group). The modifified permanent bilateral common carotid artery occlusion method was used to establish the VD model. The sham-operated and dementia groups were given 2 mL/d of saline, while the puerarin-treated group was given 100 mg/(kg•d) of puerarin for 17 days. The learning and memory abilities were evaluated by the Morris water maze test. Hematoxylin-eosin staining, immunohistochemical (IHC) staining and Western blot analysis were carried out to observe changes in neuron morphology and in level of pMeCP2 in the hippocampus, respectively. RESULTS: The morphologies of rat hippocampal neurons in the puerarintreated group were markedly improved compared with the dementia group. The escape latency of the dementia group was significantly longer than the sham-operated group (P<0.05), while the puerarin-treated group was obviously shorter than the dementia group (P<0.05). Cross-platform times of the dementia group were signifificantly decreased compared with the sham-operated group (P<0.05), while the puerarin-treated group was obviously increased compared with the dementia group (P<0.05). IHC staining showed no significant difference in the number of MeCP2 positive cells among 3 groups (P>0.05). The number of pMeCP2 positive cells in the CA1 region of hippocampus in the dementia group was signifificantly increased compared with the sham-operated group, and the puerarin-treated group was signifificantly increased compared with the dementia group (both P<0.05). Western blot analysis showed no signifificant difference of MeCP2 expression among 3 groups (P>0.05). The expression of pMeCP2 in the dementia group was signifificantly increased compared with the sham-operated group, while it in the puerarin-treated group was signifificantly increased compared with the dementia group (P<0.05). CONCLUSION: Puerarin could play a role in the protection of nerve cells through up-regulating pMeCP2 in the hippocampus, improving neuron morphologies, and enhancing learning and memory ablities in a rat model of VD.

Different Valsalva Manoeuvre Procedures for the Diagnosis of Right-to-Left Shunt by Contrast-Transcranial Doppler.

The main purpose of this study was to compare two contrast agent injection times during the Valsalva manoeuvre (VM) for the diagnosis of right-to-left shunt using contrast-transcranial Doppler (c-TCD). In total, 992 consecutive patients underwent testing. All patients underwent step 1, and then a coin toss was used to determine the order of steps 2 and 3. The following testing steps were repeated twice: (1) a contrast agent (CA) was infused at rest (CA at rest testing); (2) the VM was initiated immediately after CA injection and released 10 s after CA injection (CA pre-VM testing); and (3) a CA was injected 5 s after initiating the VM, which was released 5 s after CA injection (CA mid-VM testing). For the CA at rest, pre-VM and mid-VM groups, significant differences were observed in the positive right-to-left shunt diagnosis rates (11.49% vs. 23.08% vs. 26.11%, respectively, with an inter-group significance of p < 0.05) and grade classifications (p < 0.05). Although the times to first microbubble appearance were similar between the CA at rest and the CA pre-VM groups (8.96 ± 3.40 s vs. 8.42 ± 3.72 s, p > 0.05), it was shorter (6.4 ± 2.75 s, p < 0.05) for the CA mid-VM group than for the other two groups. For the c-TCD testing, the CA mid-VM group yielded different results for diagnosing right-to-left shunts relative to the CA pre-VM group.

[Effects of recombinant human erythropoietin on brain-derived neurotrophic factor expression in different brain regions of aging rats].

OBJECTIVE: To explore the effect of recombinant human erythropoietin (rhEPO) on expression of brain-derived neurotrophic factor (BDNF) in different brain regions of aging rats. METHODS: Forty male SD rats were randomized equally into negative control group, D-galactose group, EPO treatment group, and positive control group. Rat models of subacute aging were established by continuous subcutaneous injection of 5% D-galactose. Immunohistochemical staining was used to analyze the variation of BDNF expressions in different brain regions of the aging rats with different treatments. RESULTS: Significant brain region-specific differences in BDNF expression were found among the rats in different groups. Compared with those in the negative control group, the numbers of BDNF-positive cells in the hippocampal CA1 region, CA3 region, dentate gyrus (DG) and frontal cortex were all decreased obviously in D-galactose group (P<0.05) but increased in both EPO group and the positive control group (P<0.05) without significant differences between the latter two groups. In the rats in the same group, the number of BDNF-positive cells varied markedly in different brain regions (P<0.05), and the expression level of BDNF was the highest in the frontal cortex followed by the hippocampal CA3 region and the dentate gyrus, and was the lowest in the hippocampal CA1 region. CONCLUSION: Treatment with rhEPO enhances the expression of BDNF in rat neural cells, suggesting that rhEPO may protect the nervous system from aging by regulating the BDNF pathway.

[The anti-aging effect of EPO and the preliminary probe into its mechanisms].

OBJECTIVE: To study whether erythropoietin ( EPO) has the anti-aging effect and the mechanisms of how it effects. METHODS: 5% D-galactose hypodermic injection for 6 weeks to establish the aging model. Divided rats into 5 groups randomly: the normal control (group A), the aging model (group B), the low dosage (1 000 U/ (kg x d)) of recombinant human erythropoietin (rhEPO) intervene (group C), the middle dosage (3 000 U/(kg x d)) of rhEPO intervene (group D) and the high dosage (5 000 U/(kg x d)) of rhEPO intervene (group E), 10 rats in each group. Morris water maze was used to comparing the behavioral indexes. After decapitating the rats, the malonaldehyde (MDA), Na(+)-K+ ATPase, total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) of brain tissue were tested. One rat from each group was selected randomly to observe the hippocampal ultramicrostructure. RESULTS: (1) Compared with group A, the learning and memory ability of group B reduced, the level of MDA, the Na(+)-K+ ATPase, T-AOC and the SOD activities of brain tissue decreased (P < 0.05), besides, a series of aging changes were observed in the hippocampal ultramicro-structure in group B. (2) Compared with group B, an improved learning and memory ability of group D, a reduced MDA content and an increased activity of Na(+)-K+ ATPase, T-AOC and the SOD activities of brain tissue in group D were also observed with a improved hippocampal ultramicro-structure. (3) The low dosage of rhEPO intervention could against the decrease of the activities of brain Na(+)-K+ ATPase, SOD of aging rat (P < 0.05), but had no significant effects on the rest of the indicators. The high dosage of rhEPO intervention had no significant improvements on various indicators of aging rats in high dosage of rhEPO intervention group was noticed (P > 0.05). CONCLUSION: The middle dosage of EPO has the anti-aging effect, and its mechanisms may be related to enhancing the antioxidant enzymes activity and increasing the antioxidant capacity.

[Effect of Helicobacter pylori infection on platelet activation and coagulation function in patients with acute cerebral infarction].

OBJECTIVE: To investigate the effect of Helicobacter pylori (Hp) on platelet activation and coagulation function in patients with acute cerebral infarction. METHODS: Sixty-six patients with acute cerebral infarction and 50 health individuals were enrolled in the study. Hp antibody,expression of CD62p on platelets and clotting indexes were measured and compared between two groups. RESULTS: The positive rate of Hp-IgG and Hp-CagA in cerebral infarction patients were higher than that in controls (P<0.05). The positive rate of CD62p in patients with positive Hp-IgG and Hp-CagA was significantly higher than that in negative patients and also controls (P<0.05). The APTT and TT were lower and FIB was higher in patients with positive Hp antibody than those in patients with negative Hp antibody (P<0.05),but there was no difference in PT,PTR and INR (P>0.05). CONCLUSION: Hp infection can activate platelets and affect coagulation function,which may be involved in the development of cerebral infarction.

[Characteristic of microglial activation of hippocampus in experimental epileptic rats].

OBJECTIVE: To investigate the characteristics of microglial activation of hippocampus in experimental epileptic rats. METHODS: Morphological changes and proliferation of OX-42 positive cells were compared at different time points after status of epilepticus (SE) in lithium-pilocarpine induced epileptic rats. RESULTS: OX-42 positive cells were activated after SE, which increased to a peak at 3-7 d and in a relatively stable state at 7-14 d; then gradually decreased after 14d and returned to slightly higher level than previously at 21 d. CONCLUSION: Inflammatory injury, microglial activation and cell proliferation are closely related after seizures, microglial activation may be an important mechanism in the inflammatory injury of epilepsy.

[Effect of puerarin on the expression of NMDA receptor in the hippocampus CA1 region after focal cerebral ischemia in rats].

OBJECTIVE: To study the antagonistic action of Puerarin against the excitatory amino acid toxicity, and to further explore its brain protection mechanisms. METHODS: Focal cerebral ischemia model was set up with middle cerebral artery occlusion by intraluminal block in this study. After cerebral ischemia, Puerarin was administered at different time point. The volume of cerebral ischemia was assessed by TTC stain. NR1 positive neurons in hippocampus CA1 region was determined by immunohistochemistry SABC method. RESULTS: The cerebral ischemia volumes were smaller in 2 h and 12 h model treatment groups (P < 0.05) than those in model control groups, but no significant differences were observed in 24 h model treatment group. Compared with sham-operation group, the NR1-positive cells in hippocampal CA1 region were increased obviously (P < 0.05) in both model control and model treatment groups. Compared with model control groups, the NR1-positive cells in hippocampal CA1 were decreased obviously (P < 0.05) in 2 h and 12 h treatment groups. CONCLUSION: The treatment of Puerarin within 12 h after ischemia can cut down the expression of NMDA receptor. This indicates that the puerarin treatment in earlier period after ischemia can indirectly rivalry toxic effect of excitatory amino acids, relieve neural injury.

[Expression of glucose transporter-3 in the cerebral cortex of aging rats].

OBJECTIVE: To observe the changes in the expression of glucose transporter-3 (GLUT3) in the cerebral cortex of rats during aging and investigate the role of GLUT3 in the aging process of the nervous system. METHODS: The cerebral tissues were collected from rats of 3, 18, 24, and 30 months old (10 in each age group), and the expression of GLUT3 in the cerebral cortex was detected by immunohistochemistry. RESULTS: Under optical microscope, GLUT3-positive cells were found in every group. Within the age range of 3 to 8 months, GLUT3-positive cells increased significantly with age (P<0.01), but at 24-30 months of age, the number of GLUT3-positive cells reduced significant with age (P<0.01). CONCLUSION: The expression changes of GLUT3 ir the cerebral cortex of rats during aging indicate that GLUT3 plays an important role in the maturation and aging of the nervous system.

[Expression of vascular endothelial growth factor and microvessel density in hippocampus of rats with aging].

OBJECTIVE: To investigate the expression of vascular endothelial growth factor (VEGF) and microvessel density (MVD) in hippocampus of rats with aging. METHODS: Paraffin sections of brain tissue of rats at the age of 3, 18, 24, 30 months were stained by immunohistochemistry, the expression of VEGF and MVD was quantitatively analyzed. RESULTS: Innunohistochemical staining showed that the VEGF-positive cells were mainly pyramidal neuron in hippocampus; the intensity of VEGF-positivity in neuron cells was decreased with the aging (P<0.05). The MVD in hippocampus was also decreased with the aging of rats (P<0.05). CONCLUSION: Increasing VEGF contents and improving blood circulation in brain tissue may prevent or treat vascular dementia and cerebrovascular diseases.

[Protective effect of puerarin against calcium overload after focal cerebral ischemia injury in rats].

OBJECTIVE: To observe the temporal and spatial changes in the distribution of Ca2+ in the rat brain following focal cerebral ischemia injury and explore the protective effect of puerarin against calcium overload. METHODS: Focal cerebral ischemia was induced by middle cerebral artery occlusion in rats. After cerebral ischemia, puerarin was administered in the rats at different time points. The volume of ischemic cerebral tissue was assessed by TTC staining, and the fluorescence intensity of Ca2+ in the cortex and corpora striata was determined under laser scanning confocal microscope. RESULTS: The fluorescence intensity of Ca2+ in the infracted cortex and corpora striata begun to increase 2 h after the ischemia and was further enhanced with the prolongation of the ischemic time. No significance was found in the fluorescence intensity of Ca2+ between the cortex and corpora striata. The fluorescence intensity of Ca2+ in the infarcted corpora striata was obviously higher than that in the cortex after ischemia. Compared with that in the ischemic model group, the fluorescence intensity of Ca2+ in the infarcted cortex and corpora striata decreased significantly at 2 and 12 h following puerarin intervention (P<0.05). CONCLUSION: Puerarin treatment can relieve calcium overload, reduce cerebral ischemic volume and play a neuroprotective role against focal cerebral ischemia. Twelve hours following cerebral ischemic injury may be the time window for administering puerarin intervention.

[Expression of GLUT 3 in different brain regions of aged rats].

OBJECTIVE: To examine the distribution of glucose transport 3 (GLUT 3) in different brain regions of aged rats and to investigate its role in ageing process of the nervous system. METHODS: The GLUT 3 expression in different brain regions was examined with immunohistochemical method in rats aged 3, 18 and 30 months, respectively. RESULTS: The number of GLUT 3-positive cells varied in the different brain regions in rats of all age groups (P<0.01); the CA1 region contained the greatest number of positive cells,and fewer in the motor cortex and cerebellum. The number of GLUT 3-positive cells was reduced in the brain of aged rats (P<0.01); and the neural cells in 4 different brain regions presented with large cell body and loose alignment. CONCLUSION: The expression of GLUT 3 decreased in aged rats, which suggests that GLUT 3 may be involved in the ageing process of nervous system.

Protective effects and mechanism of puerarin on learning-memory disorder after global cerebral ischemia-reperfusion injury in rats.

OBJECTIVE: To observe the effect of puerarin on the learning-memory disorder after global cerebral ischemia-reperfusion injury in rats, and to explore its mechanism of action. METHODS: The global cerebral ischemia-reperfusion injury model was established using the modifified Pulsinelli four-vessel occlusion in Sprague-Dawley rats. Rats were intraperitoneally injected with puerarin (100 mg/kg) 1 h before ischemia and once every 6 h afterwards. The learning-memory ability was evaluated by the passive avoidance test. The dynamic changes of the cell counts of apoptosis and positive expression of Bcl-2 in the hippocampus CA1 region were determined by the TUNEL and immunohistochemical methods, respectively. RESULTS: (1) Compared with the reperfusion group, the step through latency (STL) in the passive avoidance test in the puerarin group was prolonged signifificantly (P<0.01). (2) The apoptotic neurons were injured most severely on the 3rd day in the hippocampal CA1 region after global ischemia and reperfusion. In the puerarin group, the number of apoptotic cells decreased at respective time points after ischemia-reperfusion (P<0.01). (3) The level of positive expression of Bcl-2 varied according to the duration of reperfusion and the peak level occurred on day 1 in the hippocampal CA1 region after global cerebral ischemia. Compared with the reperfusion group, the expression of Bcl-2 in the puerarin group was up-regulated at the respective time points after ischemia reperfusion (P<0.01), reaching the peak on day 1. CONCLUSIONS: Puerarin could improve the learning-memory ability after global cerebral ischemia and reperfusion in rats. The protective mechanism might be related to the effect of inhibiting or delaying the cell apoptosis through up-regulating the expression of Bcl-2 after ischemia and reperfusion.

[Hypoxia inducible factor-1alpha expression trends in hippocampus of rat of different ages].

OBJECTIVE: To reveal the expression trends of HIF-1alpha in hippocampus of different age rats, investigate the role of HIF-1alpha in the aging process of nervous system. METHODS: The cerebral tissues was collectd from rats of different age, including 3, 18, 24, 36 months old. There were 6 rats in each age group. The expressions of nissl body and HIF-1alpha in different part of hippocampus were observed by nissl staining and immunohistochemical technique. RESULTS: (1) With the increase of rat age, nerve cells appeared to be bigger and to arrange sparsely, while the nissl body decreased; (2) The positive HIF-1alpha staining cells in CA1, CA3 region of hippocampus increased along with the increase of rat age. The difference between any two age groups showed statistical significance (P < 0.05). CONCLUSION: The function of protein synthesis weakened in nerve cells but the expression of HIF-1alpha increased with the age increasing, which may play an important role in aging of nervous system.

[Expression of hypoxia inducible factor-1alpha in different brain regions in aged rats].

OBJECTIVE: To observe the distribution of hypoxia inducible factor-1alpha (HIF-1alpha) in different brain regions in aged rats and investigate the role of HIF-1alpha in the aging process of the nervous system. METHODS: The Nissl bodies and HIF-1alpha expression in different brain regions were observed in rats aged 3 and 30 months using Nissl staining and immunohistochemical method, respectively. RESULTS: In the 30-month-old rats, the neural cells in 4 different brain regions presented with large cell body and loose alignment, containing reduced Nissl bodies in the cytoplasm. Compared with the 3-month-old rats, the aged rats showed greater number of HIF-1alpha-positive cells in the brain (P < 0.01), and the number varied significantly between the different brain regions (P < 0.01). The CA3 region contained the greatest number of positive cells, which were fewer in the motor cortex and cerebellum. CONCLUSION: The capacity for protein synthesis in the neural cells is weakened but the expression of HIF-1alpha increased in aged rats, suggesting the important role that HIF-1alpha may play in the aging process of the nervous system, especially in hypomnesis.