Zinc Ameliorates Nogo-A Receptor and Osteocalcin Gene Expression in Memory-Sensitive Rat Hippocampus Impaired by Intracerebroventricular Injection of Streptozotocin.

Metabolic dysfunction is a critical step in the etiopathogenesis of Alzheimer's disease. In this progressive neurological disorder, impaired zinc homeostasis has a key role that needs to be clarified. The aim of this study was to investigate the effect of zinc deficiency and administration on hippocampal Nogo-A receptor and osteocalcin gene expression in rats injected with intracerebroventricular streptozotocin (icv-STZ). Forty male Wistar rats were divided into 5 groups in equal numbers: Sham 1 group received icv artificial cerebrospinal fluid (aCSF); Sham 2 group received icv a CSF and i.p. saline; STZ group received 3 mg/kg icv STZ; STZ-Zn-deficient group received 3 mg/kg icv STZ and fed a zinc-deprived diet; STZ-Zn-supplemented group received 3 mg/kg icv STZ and i.p. zinc sulfate (5 mg/kg/day). Hippocampus tissue samples were taken following the cervical dislocation of the animals under general anesthesia. Nogo-A receptor and osteocalcin gene expression levels were determined by real-time-PCR method. Zinc supplementation attenuated the increase in hippocampal Nogo-A receptor gene expression, which was significantly increased in zinc deficiency. Again, zinc supplementation upregulated the intrinsic protective mechanisms of the brain by activating osteocalcin-expressing cells in the brain. The results of the study show that zinc has critical effects on Nogo-A receptor gene expression and hippocampal osteocalcin gene expression levels in the memory-sensitive rat hippocampus that is impaired by icv-STZ injection. These results are the first to examine the effect of zinc deficiency and supplementation on hippocampal Nogo-A receptor and osteocalcin gene expression in icv-STZ injection in rats.

[Progress of researches on involvement of corticospinal tract in the effect of acupuncture on improvement of post-stroke motor dysfunction].

The corticospinal tract (CST), descending from the frontoparietal cortex and traveling down to terminate at the anterior horn of the spinal cord to mediate voluntary movements, is frequently injured from the infarcted or hemorrhagic cerebrovascular insults due to stroke. Under the circumstances, motor dysfunction seriously affects the patient's quality of life. Acupuncture therapy has a sequelae, especially in improving motor deficits. In the present paper, we reviewed the current development of researches on acupuncture treatment of poststroke motor dysfunction and its biological mechanisms from 1) delaying patients' development of neuronal degeneration and white matter fibrosis (Wallerian degeneration), 2) improving patients' upper limb motor function and daily life ability by promoting the repair of white matter tracts and CST on the affected side, 3) promoting the compensation of CST on the healthy side, 4) reconstructing the motor conduction pathway to strengthen the bilateral brain connection in ex-perimental animals, and 5) strengthening the sprouting of the contralateral CST to dominate the affected side again across the midline. In addition, acupuncture stimulation induced improvement of axonal rewiring for corticospinal innervation is also possibly related to its functions in accelerating the synthesis and release of neurotrophic factors, down-regulating Nogo-A/RhoA signaling and activating vascular epithelial growth factor/Dll4/Notch signaling pathways.

RTN4/Nogo-A-S1PR2 negatively regulates angiogenesis and secondary neural repair through enhancing vascular autophagy in the thalamus after cerebral cortical infarction.

Cerebral infarction induces angiogenesis in the thalamus and influences functional recovery. The mechanisms underlying angiogenesis remain unclear. This study aimed to investigate the role of RTN4/Nogo-A in mediating macroautophagy/autophagy and angiogenesis in the thalamus following middle cerebral artery occlusion (MCAO). We assessed secondary neuronal damage, angiogenesis, vascular autophagy, RTN4 and S1PR2 signaling in the thalamus. The effects of RTN4-S1PR2 on vascular autophagy and angiogenesis were evaluated using lentiviral and pharmacological approaches. The results showed that RTN4 and S1PR2 signaling molecules were upregulated in parallel with angiogenesis in the ipsilateral thalamus after MCAO. Knockdown of Rtn4 by siRNA markedly reduced MAP1LC3B-II conversion and levels of BECN1 and SQSTM1 in vessels, coinciding with enhanced angiogenesis in the ipsilateral thalamus. This effect coincided with rescued neuronal loss of the thalamus and improved cognitive function. Conversely, activating S1PR2 augmented vascular autophagy, along with suppressed angiogenesis and aggravated neuronal damage of the thalamus. Further inhibition of autophagic initiation with 3-methyladenine or spautin-1 enhanced angiogenesis while blockade of lysosomal degradation by bafilomycin A1 suppressed angiogenesis in the ipsilateral thalamus. The control of autophagic flux by RTN4-S1PR2 was verified in vitro. Additionally, ROCK1-BECN1 interaction along with phosphorylation of BECN1 (Thr119) was identified in the thalamic vessels after MCAO. Knockdown of Rtn4 markedly reduced BECN1 phosphorylation whereas activating S1PR2 increased its phosphorylation in vessels. These results suggest that blockade of RTN4-S1PR2 interaction promotes angiogenesis and secondary neural repair in the thalamus by suppressing autophagic activation and alleviating dysfunction of lysosomal degradation in vessels after cerebral infarction.Abbreviations: 3-MA: 3-methyladenine; ACTA2/ɑ-SMA: actin alpha 2, smooth muscle, aorta; AIF1/Iba1: allograft inflammatory factor 1; BafA1: bafilomycin A1; BMVECs: brain microvascular endothelial cells; BrdU: 5-bromo-2'-deoxyuridine; CLDN11/OSP: claudin 11; GFAP: glial fibrillary acidic protein; HUVECs: human umbilical vein endothelial cells; LAMA1: laminin, alpha 1; MAP2: microtubule-associated protein 2; MBP2: myelin basic protein 2; MCAO: middle cerebral artery occlusion; PDGFRB/PDGFRß: platelet derived growth factor receptor, beta polypeptide; RECA-1: rat endothelial cell antigen-1; RHOA: ras homolog family member A; RHRSP: stroke-prone renovascular hypertensive rats; ROCK1: Rho-associated coiled-coil containing protein kinase 1; RTN4/Nogo-A: reticulon 4; RTN4R/NgR1: reticulon 4 receptor; S1PR2: sphingosine-1-phosphate receptor 2; SQSTM1: sequestosome 1.

Electroacupuncture Inhibits Myelin Sheath Injury in the Internal Capsule After Focal Cerebral Infarction in Rats Through the Nogo-A/NgR Signaling Pathway.

BACKGROUND Ischemic stroke is usually accompanied by white matter damage. The effect of electroacupuncture (EA) on ameliorating white matter damage is still unclear. The purpose of this study was to explore the precise mechanism of EA in treating ischemic white matter. MATERIAL AND METHODS In this study, 40 Sprague-Dawley rats were randomly divided into 4 groups: normal group, the sham-operated group, model group, and EA group. The stroke model was established by right middle cerebral artery occlusion, and EA was performed 24 h after the operation for 30 min per day. After 14 days of treatment, brain tissue samples were collected. Hematoxylin and eosin and Luxol fast blue staining were used to observe the changes of white matter damage in the internal capsule (IC). The expression levels of myelin basic protein (MBP), Nogo-A, and Nogo-A receptor (NgR) were detected by immunohistochemistry and western blot. RESULTS Compared with the sham-operated group, the model group had decreased expression of MBP and significantly increased expression of Nogo-A and NgR (P<0.05). Compared with the model group, the IC damage was alleviated in the EA group. Immunohistochemistry and western blot analysis showed that EA significantly increased the expression of MBP in white matter (P<0.05) and downregulated the expression levels of Nogo-A and NgR (P<0.05). CONCLUSIONS The results of this study indicate that EA can inhibit the expression of Nogo-A/NgR and promote myelin sheath regeneration.

Effect of Naoluoxintong on the NogoA/RhoA/ROCK pathway by down-regulating DNA methylation in MCAO rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Naoluoxintong (NLXT) is a traditional Chinese Medicine (TCM) prescription that is clinically used in the treatment of ischemic stroke (IS). However, its therapeutic mechanism remains unclear. AIM OF THE STUDY: To obtain the mechanism of NLXT by observing the protective effects of NLXT on the NogoA/RhoA/Rock pathway in a rat model of IS by regulating DNA methylation. MATERIALS AND METHODS: Rats were divided into five groups using a random number table: normal group, model group, NLXT group, blocker group I (NLXT + SGI-1027) and blocker group II (NLXT + Y27632). The right middle cerebral artery occlusion-reperfusion (MCAO/R) rat model was made, and the regional cerebral blood flow (rCBF) of each group was detected using laser Doppler. The methylation levels of CpG sites of neurite outgrowth inhibitor protein-A (Nogo-A), Nogo receptor (NgR), ras homolog gene family member A (RhoA) and rho-associated coiled-coil protein kinase 2 (ROCK2) genes in rat brain tissue were detected using the bisulfite method. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect NogoA, RhoA, NgR1, NgR2 and ROCK2 mRNA expression in rat brain tissue. NogoA, RhoA, NgR1, NgR2 and ROCK2 proteins were detected using immunoblotting in rat brain tissue. RESULTS: After the modeling of middle cerebral artery occlusion (MCAO), neurological deficit test was made to ensure the success of the modeling. At each time point after surgery, the rCBF of the other groups decreased compared with the normal group (P < 0.01 or P < 0.05). Meanwhile, the rCBF increased in blocker group I as well as blocker group II after 3 days (P < 0.05). There were differences in the DNA methylation sites of NogoA, RhoA, NgR and ROCK2 genes between the model group and the NLXT group (P < 0.05). Compared with the normal group, NogoA, NgR1, NgR2, RhoA and ROCK2 gene expression in the model group increased observably (P < 0.01). In comparison with the model group, NogoA and NgR1 gene expression in the blocker group II was prominently observed on the 1st day. NogoA, NgR1, NgR2, RhoA and ROCK2 gene expression remarkably reduced (P < 0.01) on the 3rd and 7th days. Compared with the normal group, NogoA, RhoA, NgR1, NgR2 and ROCK2 protein expression in the model group increased observably (P < 0.01). In comparison with the model group, NogoA, RhoA, NgR1, NgR2 and ROCK2 protein expression in the other groups declined prominently (P < 0.01). CONCLUSION: NLXT can reduce the DNA methylation level of NogoA pathway after IS, thus inhibit the expression of NogoA/RhoA/ROCK pathway from producing anti-cerebral ischemia pharmacological effect.

Combination of Electroacupuncture and Constraint-Induced Movement Therapy Enhances Functional Recovery After Ischemic Stroke in Rats.

Both electroacupuncture and constraint-induced movement therapy have been reported to produce therapeutic effects on the recovery of ischemic stroke. The combined use of these two therapies is not rare clinically, although its effectiveness is not yet clear. We aimed to evaluate the efficacy of the combination of electroacupuncture and constraint-induced movement therapy in ischemic stroke rats, and to explore the potential molecular mechanisms. Ischemic stroke rat models were established by middle cerebral artery occlusion. Then, the rats were assigned to receive one of the following interventions: sole electroacupuncture, sole constraint-induced movement therapy, the combination of both therapies, and no treatment. Functional recovery was assessed with the beam balance test and rotarod test. The infarct volume of the brain and the expression of the molecules Nogo-A, P75NTR, NGF, BDNF, and VEGF in the brain tissue were investigated. The results demonstrated that the combination of the two therapies significantly improved neurological functional recovery in ischemic stroke rats compared to each therapy alone (P < 0.01). We also observed a significant decrease in infarct volume in rats receiving the combined treatment. Nogo-A and P75NTR were downregulated and NGF, BDNF, and VEGF were upregulated in the combined treatment rats compared to the control rats. In conclusion, the combination of electroacupuncture and constraint-induced movement therapy enhanced functional recovery after ischemic stroke in rats, and it is a promising treatment strategy in the rehabilitation of stroke. The anti-Nogo-A effect of electroacupuncture may explain its good compatibility with CIMT in ischemic stroke rats.

Spirulina platensis reduces the schizophrenic-like symptoms in rat model by restoring altered APO-E and RTN-4 protein expression in prefrontal cortex.

AIMS: Schizophrenia (SZ) is recognized as a neuropsychiatric disorder in humans with accelerated mortality and profound morbidity followed with impairments in social as well as vocational functioning. Though various antipsychotics are being considered as approved treatment therapy for the psychotic symptoms of SZ but they also exert adverse effects and also lack efficacy in treating full spectrum of the disorder. Spirulina platensis (blue-green algae), a nutritional supplement, constitutes a variety of multi-nutrients and possesses a large number of neuroprotective activities. Therefore, present experimental work was designed to evaluate the neuroprotective effects of spirulina in ameliorating the psychosis-like symptoms in dizocilpine-induced rat model of SZ. MATERIALS AND METHODS: The spirulina was tested as preventive and therapeutic regimen at the dose of 180 mg/kg. After pre- and post-treatment with spirulina, rats were subjected to behavioral assessments followed by biochemical and neurochemical estimations. Biomarkers including APO-E, RTN-4, TNF-α, and IL-6 were also estimated using ELISA. KEY FINDINGS: Present results showed that administration of spirulina not only improved behavioral deficits induced by dizocilpine but it also regulates neurotransmission, oligodendrocyte dysfunction and APO-E over expression. Moreover, it also restores the immune response dysfunction by reducing inflammatory cytokines. SIGNIFICANCE: Thus, from present findings it may be suggested that spirulina aids in ameliorating the psychosis-like symptoms induced by dizocilpine in animal model possibly via regulation of neurotransmission and other biomarkers that are extensively used to uncover the etiopathology of SZ. Hence, blue-green algae can be used as an effective therapy for preventive or therapeutic measures in SZ.

Xuesaitong exerts long-term neuroprotection for stroke recovery by inhibiting the ROCKII pathway, in vitro and in vivo.

ETHNOPHARMACOLOGICAL RELEVANCE: Xuesaitong (XST) is a traditional Chinese medicine injection with neuroprotective properties and has been extensively used to treat stroke for many years. The main component of XST is Panax notoginseng saponins (PNS), which is the main extract of the Chinese herbal medicine Panax notoginseng. AIM OF THE STUDY: In this study, we investigated whether XST provided long-term neuroprotection by inhibiting neurite outgrowth inhibitor-A (Nogo-A) and the ROCKII pathway in experimental rats after middle cerebral artery occlusion (MCAO) and in SH-SY5Y cells exposed to oxygen-glucose deprivation/reperfusion (OGD/R). MATERIALS AND METHODS: Rats with permanent MCAO were administered XST, Y27632, XST plus Y27632, and nimodipine for 14 and 28 days. Successful MCAO onset was confirmed by 2,3,5-triphenyl tetrazolium chloride (TTC) staining. Neurological deficit score (NDS) was used to assess neurological impairment. Hematoxylin-eosin (HE) staining and immunohistochemical (IHC) analysis of synaptophysin (SYN) and postsynaptic density protein-95 (PSD-95) were performed to evaluate cerebral ischemic injury and the neuroprotective capability of XST. Nogo-A levels and the ROCKII pathway were detected by IHC analysis, western blotting, and quantitative real-time polymerase chain reaction (qRT-PCR) to explore the protective mechanism of XST. OGD/R model was established in SH-SY5Y cells. Cell counting kit 8 (CCK8) was applied to detect the optimum OGD time and XST concentration. The expression levels Nogo-A and ROCKII pathway were determined using western blotting. RESULTS: Our results showed that XST reduced neurological dysfunction and pathological damage, promoted weight gain and synaptic regeneration, reduced Nogo-A mRNA and protein levels, and inhibited the ROCKII pathway in MCAO rats. CCK8 assay displayed that the optimal OGD time and optimal XST concentration were 7 h and 20 µg/mL respectively in SH-SY5Y cells. XST could evidently inhibit OGD/R-induced Nogo-A protein expression and ROCKII pathway activation in SH-SY5Y cells. CONCLUSIONS: The present study suggested that XST exerted long-term neuroprotective effects that assisted in stroke recovery, possibly through inhibition of the ROCKII pathway.

Anti-apoptotic efficacy of Qingnao Yizhi formula in hypoxia/reoxygenation primary cortical neurons through the promotion of synaptic plasticity by modulating the NogoA-Nogo receptor/Rho-Rho kinase signaling pathway.

OBJECTIVE: To evaluate the anti-apoptotic efficacy of Qingnao Yizhi formula (，QNYZ) in cultured cerebral cortical neuronal cells (CNCs) and the regulation of the NogoA-Nogo receptor (NgR)/Rho-Rho kinase (ROCK) signaling pathway. METHODS: Primary cultured CNCs were randomly divided into the following groups: normal control group (N-C), hypoxia-reoxygenation group (H/R), high-dose QNYZ group (Q-H), low-dose QNYZ group (Q-L) butylphthalide (NBP) group, and Y-27632 (a selective ROCK transduction pathway inhibiter) group. Except those in the N-C group, CNCs were placed in hypoxic conditions for 24 h and then in reoxygenation conditions for 24 h. Cell media was changed every 48 h, and various assays were performed on the 7th day. Cell viability was evaluated by measuring mitochondrial dehydrogenase activity, using a CCK-8 assay, in triplicate. Synapsin (SYN) protein concentrations were evaluated by enzyme-linked immunosorbent assay. NogoA and RhoA protein expression were evaluated through Western blotting. The gene expression of NogoA, NgR, RhoA, and ROCK was evaluated by reverse transcription-polymerase chain reaction. Cell apoptosis was measured using a terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling assay. RESULTS: Compared with the N-C group, the cell viability of the H/R group decreased significantly (P < 0.05). The cell viability values for the Q-H and Q-L groups increased compared with that for the H/R group, and the difference was significant for the Q-H group (P < 0.05). The NogoA and RhoA protein levels and the NogoA, NgR, RhoA, and ROCK mRNA expression levels increased in the H/R group, compared with the N-C group, and decreased significantly in the Q-H and Q-L groups (P < 0.05) and in the Y-27632 group (P < 0.05) compared with the H/R group. The SYN levels in the Q-H, Q-L, and NBP groups significantly increased compared with that in the H/R group (P < 0.05). Compared with the H/R group, the numbers of apoptotic cells in the Q-H, Q-L, and NBP groups significantly decreased (P < 0.05). CONCLUSION: The presented study demonstrated that QNYZ exerted anti-apoptotic effects on H/R-induced CNCs, possibly through the modulation of the NogoA-NgR/Rho-ROCK signaling pathway and the promotion of synaptic plasticity in H/R CNCs.

Fasudil alleviates brain damage in rats after carbon monoxide poisoning through regulating neurite outgrowth inhibitor/oligodendrocytemyelin glycoprotein signalling pathway.

Carbon monoxide (CO) poisoning can lead to many serious neurological symptoms. Currently, there are no effective therapies for CO poisoning. In this study, rats exposed to CO received hyperbaric oxygen therapy, and those in the Fasudil group were given additional Fasudil injection once daily. We found that the escape latency in CO poisoning group (CO group) was significantly prolonged, the T1 /Ttotal was obviously decreased, and the mean escape time and the active escape latency were notably extended compared with those in normal control group (NC group, P < 0.05). After administration of Fasudil, the escape latency was significantly shortened, T1 /Ttotal was gradually increased as compared with CO group (>1 week, P < 0.05). Ultrastructural damage of neurons and blood-brain barrier of rats was serious in CO group, while the structural and functional integrity of neuron and mitochondria maintained relatively well in Fasudil group. Moreover, we also noted that the expressions of neurite outgrowth inhibitor (Nogo), oligodendrocyte-myelin glycoprotein (OMgp) and Rock in brain tissue were significantly increased in CO group, and the elevated levels of the three proteins were still observed at 2 months after CO poisoning. Fasudil markedly reduced their expressions compared with those of CO group (P < 0.05). In summary, the activation of Nogo-OMgp/Rho signalling pathway is associated with brain injury in rats with CO poisoning. Fasudil can efficiently down-regulate the expressions of Nogo, OMgp and Rock proteins, paving a way for the treatment of acute brain damage after CO poisoning.

Effects of Bu Shen Yi sui capsule on NogoA/NgR and its signaling pathways RhoA/ROCK in mice with experimental autoimmune encephalomyelitis.

BACKGROUND: Axon growth inhibitory factors NogoA/Nogo receptor (NgR) and its signaling pathways RhoA/Rho kinase (ROCK) play a critical role in the repair of nerve damage in multiple sclerosis (MS). Bu Shen Yi Sui Capsule (BSYSC) is an effective Chinese formula utilized to treat MS in clinical setting and noted for its potent neuroprotective effects. In this study, we focus on the effects of BSYSC on promoting nerve repair and the underlying mechanisms in mice with experimental autoimmune encephalomyelitis (EAE), an animal model of MS. METHODS: The EAE mouse model was induced by injecting subcutaneously with myelin oligodendrocyte glycoprotein (MOG) 35-55 supplemented with pertussis toxin. BSYSC was orally administrated at dose of 3.0 g/kg once a day for 40 days. The levels of protein gene product (PGP) 9.5, p-Tau, growth associated protein (GAP) -43, KI67 and Nestin in the brain or spinal cord on 20 and 40 day post-induction (dpi) were detected via immunofluorescence and Western blot analysis. Furthermore, NogoA/NgR and RhoA/ROCK signaling molecules were studied by qRT-PCR and Western blot analysis. RESULTS: Twenty or 40 days of treatment with BSYSC increased markedly PGP9.5 and GAP-43 levels, reduced p-Tau in the brain or spinal cord of mice with EAE. In addition, BSYSC elevated significantly the expression of KI67 and Nestin in the spinal cord 40 dpi. Further study showed that the activation of NogoA/NgR and RhoA/ROCK were suppressed by the presence of BSYSC. CONCLUSIONS: BSYSC could attenuate axonal injury and promote repair of axonal damage in EAE mice in part through the down-regulation of NogoA/NgR and RhoA/ROCK signaling pathways.

Matrine Treatment Blocks NogoA-Induced Neural Inhibitory Signaling Pathway in Ongoing Experimental Autoimmune Encephalomyelitis.

Myelin-associated inhibitors, such as NogoA, myelin-associated glycoprotein (MAG), and oligodendrocyte myelin glycoprotein (OMgp), play a pivotal role in the lack of neuroregeneration in multiple sclerosis, an inflammatory demyelinating disease of the central nervous system (CNS). Matrine (MAT), a monomer that is used in traditional Chinese medicine as an anti-inflammatory agent, has shown beneficial effects in experimental autoimmune encephalomyelitis (EAE), an animal model of MS. However, the underlying mechanisms of MAT-induced EAE amelioration are not fully understood. In the present study, we show that MAT treatment suppressed ongoing EAE, and this effect correlated with an increased expression of growth-associated protein 43, an established marker for axonal regeneration. MAT treatment significantly reduced the levels of NogoA, its receptor complex NgR/p75NTR/LINGO-1, and their downstream RhoA/ROCK signaling pathway in the CNS. In contrast, intracellular cyclic AMP (cAMP) levels and its protein kinase (protein kinase A (PKA)), which can promote axonal regrowth by inactivating the RhoA, were upregulated. Importantly, adding MAT in primary astrocytes in vitro largely induced cAMP/PKA expression, and blockade of cAMP significantly diminished MAT-induced expression of PKA and production of BDNF, a potent neurotrophic factor for neuroregeneration. Taken together, our findings demonstrate that the beneficial effects of MAT on EAE can be attributed not only to its capacity for immunomodulation, but also to its directly promoting regeneration of the injured CNS.

BDNF/PI3K/Akt and Nogo-A/RhoA/ROCK signaling pathways contribute to neurorestorative effect of Houshiheisan against cerebral ischemia injury in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Houshiheisan (HSHS), a classic traditional medicine prescription, has notable effects on patients with stroke AIM OF THE STUDY: To investigate the neurorestorative effects of HSHS on ischemic stroke and explore its mode of action. MATERIALS AND METHODS: Focal cerebral ischemia models were induced by permanent middle cerebral artery occlusion (pMCAO). Male Sprague-Dawley (SD) rats were randomly divided into 5 experimental groups: sham vehicle, ischemia vehicle, pMCAO+HSHS at 5.1, 10.2g/kg, and pMCAO+Ginaton 0.028g/kg. HSHS or Ginaton was administrated 6h after pMCAO onset. Neurological function was assessed and then rats were sacrificed 7 days after MCAO. Cerebral ischemic injury was evaluated by hematoxylin and eosin (HE) staining and Neuronal nuclear antigen (NeuN) immunofluorescence analysis. The levels of BDNF were detected by enzyme linked immunosorbent assay (ELISA), and the expression levels of PI3K/Akt and Nogo-A/RhoA/ROCK2 signaling pathway were detected by western blot and quantitative real-time PCR (qRT-PCR). RESULTS: Compared with those results of pMCAO group, HSHS 5.1 and HSHS 10.2 groups markedly improved neurological function, alleviated pathological damage, promoted the neuronal survival, increased the expression of BDNF, PI3K, Akt, in protein and mRNA, decreased the expression of Nogo-A, NgR, RhoA and ROCK2 in protein and mRNA 7 days after pMCAO. CONCLUSIONS: The findings demonstrate that HSHS had significant therapeutic effects on ischemic stroke and it perhaps worked through the activation of BDNF/PI3K/Akt and down-regulation of Nogo-A/RhoA/ROCK signaling pathways.

Nogo receptor complex expression dynamics in the inflammatory foci of central nervous system experimental autoimmune demyelination.

BACKGROUND: Nogo-A and its putative receptor NgR are considered to be among the inhibitors of axonal regeneration in the CNS. However, few studies so far have addressed the issue of local NgR complex multilateral localization within inflammation in an MS mouse model of autoimmune demyelination. METHODS: Chronic experimental autoimmune encephalomyelitis (EAE) was induced in C57BL/6 mice. Analyses were performed on acute (days 18-22) and chronic (day 50) time points and compared to controls. The temporal and spatial expression of the Nogo receptor complex (NgR and coreceptors) was studied at the spinal cord using epifluorescent and confocal microscopy or real-time PCR. Data are expressed as cells/mm2, as mean % ± SEM, or as arbitrary units of integrated density. RESULTS: Animals developed a moderate to severe EAE without mortality, followed by a progressive, chronic clinical course. NgR complex spatial expression varied during the main time points of EAE. NgR with coreceptors LINGO-1 and TROY was increased in the spinal cord in the acute phase whereas LINGO-1 and p75 signal seemed to be dominant in the chronic phase, respectively. NgR was detected on gray matter NeuN+ neurons of the spinal cord, within the white matter inflammatory foci (14.2 ± 4.3 % NgR+ inflammatory cells), and found to be colocalized with GAP-43+ axonal growth cones while no ß-TubIII+, SMI-32+, or APP+ axons were found as NgR+. Among the NgR+ inflammatory cells, 75.6 ± 9.0 % were microglial/macrophages (lectin+), 49.6 ± 14.2 % expressed CD68 (phagocytic ED1+ cells), and no cells were Mac-3+. Of these macrophages/monocytes, only Arginase-1+/NgR+ but not iNOS+/NgR+ were present in lesions both in acute and chronic phases. CONCLUSIONS: Our data describe in detail the expression of the Nogo receptor complex within the autoimmune inflammatory foci and suggest a possible immune action for NgR apart from the established inhibitory one on axonal growth. Its expression by inflammatory macrophages/monocytes could signify a possible role of these cells on axonal guidance and clearance of the lesioned area during inflammatory demyelination.

Effect of total flavonoids of Scutellaria barbata on cognitive function and nogo-A expression in the hippocampus in cerebral ischemia model in gerbils.

To explore the effect of total flavonoids of Scutellaria barbata on cognitive function and nogo-A expression in the hippocampus region in cerebral ischemia model in gerbils. 30 gerbils were randomly divided into model group, sham operation group, large dose of total flavonoids of Scutellaria barbata group (large dose group), middle dose of total flavonoids of Scutellaria barbata group (middle dose group) and small dose of total flavonoids of Scutellaria barbata group (small dose group), with 6 cases in each group. All the groups except the sham operation group were received bilateral common carotid artery ligation to establish the cerebral ischemia model in gerbils. After that, the large, middle and small doses groups were given 400mg/kg, 200mg/kg and 100mg/kg of total flavonoids of Scutellaria barbata respectively, while the other two groups were injected with sodium chloride for 4 continuous weeks. At the 5th and 8th week after modeling, the cognitive function (e.g. escape latency period and original platform crossing times) of the gerbils in the three groups were detected by Morris water maze test. Moreover, the nogo-A expressions in the hippocampus region were detected by immunohistochemical staining method at the 8th week. The escape latency period and platform crossing times at the 5th and 8th week after modeling in the large dose group were significantly higher than the rest groups (except slam operation group) (p<0.05), while the difference was not significant when compared with slam operation group (p>0.05). The difference of the gray value of nogo-A positive cells in hippocampus in the large dose group was not significant compared with middle dose group and sham operation group (p>0.05), while it was significant compared with model group and small dose group (p<0.05). Large dose of total flavonoids of Scutellaria barbata can obviously improve the cognitive function in cerebral ischemia model in gerbils by reducing nogo-A expression in the hippocampus region.