Improved neurite outgrowth on central nervous system myelin substrate by siRNA-mediated knockdown of Nogo receptor / 中华创伤杂志(英文版)

<p><b>PURPOSE</b>To investigate the in vitro effect of short interfering RNAs (siRNAs) against Nogo receptor (NgR) on neurite outgrowth under an inhibitory substrate of central nervous system (CNS) myelin.</p><p><b>METHODS</b>Three siRNA sequences against NgR were designed and transfected into cerebellar granule cells (CGCs) to screen for the most effcient sequence of NgR siRNA by using reverse transcription polymerase chain reaction (RT-PCR) and immunofluorescence staining. NgR siRNA sequence 1 was found the most efficient which was then transfected into the CGCs grown on CNS myelin substrate to observe its disinhibition for neurite outgrowth.</p><p><b>RESULTS</b>Compared with the scrambled control sequence of siRNA, the NgR siRNA sequence 1 significantly decreased NgR mRNA level at 24 h and 48 h (p <0.05), which was recovered by 96 h after transfection. NgR immunoreactivity was also markedly reduced at 24 and 48 h after the transfection of siRNA sequence 1 compared with that before transfection (p<0.05). The NgR immunoreactivity was recovered after 72 h post-transfection. Moreover, the neurite outgrowth on the myelin substrate was greatly improved within 72 h after the transfection with siRNA sequence 1 compared with the scrambled sequence-transfected group or non-transfected group (p<0.05).</p><p><b>CONCLUSION</b>siRNA-mediated knockdown of NgR expression contributes to neurite outgrowth in vitro.</p>

Neuroprotective effect of Nogo-66 receptor silencing in preterm rats with brain injury caused by intrauterine infection / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the effect of Nogo-66 receptor (NgR) silencing with specific small interfering RNA (siRNA) on brain injury repair in preterm rats with brain injury caused by intrauterine infection and related mechanism of action.</p><p><b>METHODS</b>The pregnant Sprague-Dawley rats (with a gestational age of 15 days) were selected, and premature delivery was induced by RU486 or lipopolysaccharide (LPS). The preterm rats delivered by those treated with RU486 were selected as the control group. The preterm rats with brain injury caused by intrauterine infection induced by LPS were divided into model, empty vector, and NgR-siRNA groups, with 36 rats in each group. The rats in the control and model groups were given routine feeding only, and those in the empty vector and NgR-siRNA groups were given an injection of lentiviral empty vector or NgR-siRNA lentivirus via the lateral ventricle on postnatal day 1 (P1) and then fed routinely. On P3, P7, and P14, 8 rats in each group were randomly selected and sacrificed to harvest the brain tissue. RT-PCR was used to measure the mRNA expression of NgR. Western blot was used to to measure the protein expression of active RhoA. The immunofluorescence histochemistry was used to determine the degree of activation of microglial cells and the morphology of oligodendrocyte precursor cells (OPCs). Hematoxylin and eosin staining was used to observe the pathological changes in brain tissue. The behavioral score was evaluated on P30.</p><p><b>RESULTS</b>On P3, the NgR-siRNA group had significantly lower mRNA expression of NgR and protein expression of active RhoA in brain tissue than the model and empty vector groups (P<0.05). In each group, the mRNA expression of NgR was positively correlated with the protein expression of active RhoA (P<0.05). The results of immunofluorescence histochemistry showed that on P3, the NgR-siRNA group had a significantly reduced fluorescence intensity of the microglial cells labeled with CD11b compared with the model and empty vector groups (P<0.05). The OPCs labeled with O4 antibody in the four groups were mainly presented with tripolar cell morphology. The results of pathological examination showed a normal structure of white matter with clear staining in the periventriclar area in the control group, a loose structure of white matter with disorganized fibers and softening lesions in the model and empty vector groups, and a loose structure of white matter with slightly disorganized fibers, slight gliocyte proliferation, and no significant necrotic lesions in the NgR-siRNA group. As for the behavioral score, compared with the model and empty vector groups, the NgR-siRNA group had a higher score in the suspension test, a longer total activity distance, and greater mean velocity and number of squares crossed, as well as a shorter time of slope test and a shorter time and distance of activity in the central area (P<0.05), while there were no significant differences in these parameters between the NgR-siRNA and control groups (P>0.05).</p><p><b>CONCLUSIONS</b>NgR silencing with specific siRNA can effectively silence the expression of NgR in pertem rats with brain injury caused by interauterine infection and has a significant neuroprotective effect in brain injury repair.</p>

Effects of Jisuikang on Nogo-NgR gene expression in spinal cord rats with injury / 中国骨伤

<p><b>OBJECTIVE</b>To study the effects of Jisuikang (Chinese characters) on Nogo-NgR gene expression, and to explore the protective effects and mechanism of Jisuikang (Chinese characters) on spinal cord injury in rats.</p><p><b>METHODS</b>One hundred eighty female rats were randomly assigned to 6 groups(30 rats per group). Sham group: T10 lamina was resected only and spinal cord was untreated. Model group: spine cord injury (SCI) was created with a modified impinger of Allen's by impacting on the T10 spinal cord. Prednisolone group: Prednisolone (0.06 g/kg) was given by intragastric administration at a time interval of 24 hours after operation. The Jisuikang (Chinese characters) high, moderate and low dose groups: Jisuikang (Chinese characters) was supplied with different dose (50 g/kg, 25 g/kg, 12.5 g/kg) by intragastric administration in rats after operation,for the first time at 30 min after surgery. Animals were killed 3, 7, 14 days after surgery. The expression levels of Nogo-A and NgR were observed by Western Blot and Real-time PCR.</p><p><b>RESULTS</b>The expression of Nogo-A and NgR was at the basic level at all time points in sham group. Compared with model group, the protein expression levels of Nogo-A and NgR in sham, prednisolone, Jisuikang (Chinese characters) moderate dose groups were statistically significant at all time points (P < 0.05). No difference was found in Jisuikang (Chinese characters) high and low dose groups (P > 0.05). Three days after surgery, the mRNA levels of Nogo-A and NgR in treatment group were significantly lower than that in model group (P < 0.01); 7 days after surgery,Nogo-A and NgR mRNA expression were dramatically upregulated and peaked; 14 days after operation, the expression was decreased, but still significantly higher than that in other treatment groups (P < 0.01). Prednisolone and Jisuikang (Chinese characters) moderate dose groups showed the most significant effects among all groups,but there was no statistically significant difference between two groups (P > 0.05).</p><p><b>CONCLUSION</b>The decoction Jisuikang (Chinese characters) can promote the nerve cell regeneration by regulating Nogo-A and NgR gene expression, activating Nogo- NgR signaling pathways after acute spinal cord injury.</p>

Effect of electric acupuncture on the expression of NgR in the cerebral cortex, the medulla oblongata, and the spinal cord of hypertensive rats after cerebral infarction / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To observe the effect of electric acupuncture (EA) on the Nogo receptors (NgR) protein expression in the cerebral cortex, the medulla oblongata, and the spinal cord of cerebral ischemia-reperfusion (I/R) stroke-prone renovascular hypertensive rats (RHRSP) with middle cerebral artery occlusion (MCAO) at different time points, and to investigate its possible mechanisms for remote-organ injury of acute cerebral infarction (ACI).</p><p><b>METHODS</b>The RHRSP model was duplicated in male SPF grade SD rats. Then the MCAO model was prepared by a thread stringing method. Rats were divided into the hypertension group,the sham-operation group, the MCAO group, the EA group, and the sham-acupoint group by random number table method, 60 in each group. Rats in the MCAO group only received MCAO reperfusion treatment. Those in the sham-operation group only received surgical trauma. Baihui (DU20) and Dazhui (DU14) were needled in the EA group, once daily for a total of 28 days.The needles were acupunctured at the skin one cun distant from Baihui (DU20) and Dazhui (DU14) and then the same EA treatment was performed in the sham-acupoint group. At day 1, 7, 14, 28 after treatment, six rats were executed from each group, and their right cortex and medulla oblongata, and the left spinal cord were isolated. The infarct volume was detected by Nissl's staining method. The NgR expression was detect by Western blot.</p><p><b>RESULTS</b>(1) In the cortex area: compared with the hypertension group,the NgR expression increased in the MCAO group at day 1,7,14,and 28 after MCAO (P < 0.05). Compared with the MCAO group, the NgR expression of the EA group and the sham-acupoint group were equivalent at 1 day af ter MCAO (P > 0.05). At day 7, 14,and 28 after MCAO, the NgR expression decreased in the EA group (P < 0.05), it was quite similar to that in the sham-acupoint group (P > 0.05). (2) In the medulla oblongata area: compared with the hypertension group, the NgR expression was equivalent in the sham-operation group. the MCAO group,the EA group, and the sham-acupoint group at 1 day after MCAO (P > 0.05). At day 7.14, and 28 after MCAO, the NgR expression increased in the MCAO group (P < 0.05). Compared with the MCAO group,the NgR expression decreased in the EA group at day 7, 14, and 28 after MCAO (P < 0.05), whereas it was similar in the sham-acupoint group (P > 0.05). (3) In the spinal cord area: compared with the hypertension group, the NgR expression was equivalent in the sham-operation group, the MCAO group,the EA group, and the sham-acupoint group at day 1 and 7 after MCAO (P > 0.05). At day 14 and 28 after MCAO, the NgR expression increased in the MCAO group (P < 0.05). Compared with the MCAO group, the NgR expression decreased in the EA group at day 14 and 28 after MCAO (P < 0.05), whereas it was equivalent in the sham-acupoint group (P > 0.05).</p><p><b>CONCLUSIONS</b>Increased NgR expression in the cerebral cortex, the medulla oblongata, and the spinal cord of cerebral infarct rats was an important reason for involving remote-organ injury of ACI. The protective effect of EA on hypertensive I/R cerebral injury rats might be closely related to down-regulating central nervous system myelin growth inhibition mediated factors Nogo-A receptor NgR protein expression.</p>

Silenced NgR gene expression by RNA interference to promote rats facial nerve regeneration in vitro / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To suppress NgR gene expression in neural stem cells and observe differentiation of neural stem cells in vitro after interfered which provide nutritional support for the facial nerve repair in vivo.@*METHOD@#PCR amplification, restriction endonuclease digestion, T4DNA ligase connections were used to connected NgR with rector pGCsi, and constructed recombinant vector (NgR shRNA). Lipofectamine 2000 were used to transfect the NSC. The expression of NgR was examined by Western Blot. The proportion of neural stem cells transformed into neurons after transfection was tested by Immunocytochemistry. Neural stem cells were planted in PLGA tubes after transfected, and were scanned by electron microscopy.@*RESULT@#NgR shRNA plasmid was constructed and infected neural stem cells successfully. Western Blot showed that the expression of NgR decreased in neural stem cells after interference. Immunocytochemistry showed that the rate of the neural stem cells transformed into neurons after interfered was significantly higher (P < 0.01).@*CONCLUSION@#Neural stem cells were transformed into neurons after NgR shRNA plasmid infected neural stem cells, which promoted axonal regeneration more effectively and provided a efficient and stable gene platform for facial nerve repair.

Expression of Nogo receptor in brain and neuroprotective effect of NEP1-40 on hypoxic ischemic brain damage in newborn rats / 中华儿科杂志

<p><b>OBJECTIVE</b>The hypoxic-ischemic encephalopathy caused by asphyxia in peripartum is a serious disease in newborn infants, with a high disability and mortality rate. Lack of regenerative ability in central nervous system after injury is considered as the fundamental cause. However, in recent years many studies have revealed that there are myelin-associated neurite growth inhibitory factors that exert inhibiting effect through the Nogo receptor (NgR). This study aimed to investigate the expression level of NgR and the possible neuroprotective effect of NEP1-40 in newborn rats with hypoxic ischemic brain damage (HIBD).</p><p><b>METHOD</b>Eighty healthy Wistar rats aged 7 days were randomly divided into 4 groups; 8 in control group, 24 in HIBD model group, 24 in GM-1 group and 24 in NEP1-40 group. The rats of the control group and HIBD group were injected with normal saline (0.25 ml/kg) intraperitoneally, while those in NEP1-40 group and GM-1 group with NEP1-40 12.5 microg/d, GM-1 10 mg/(kg.d) for continuous 3 days of 72-hour group or 7 days of 168-hour group, respectively. In situ hybridization was adopted for detecting the expression of NgR in the brain of the rats at the time point of 24 hours, 72 hours and 7 days. Meanwhile histopathological changes of neurons and axon were detected by transmission electron microscopy (TEM). The SPSS statistical software package for Windows, version 10.0, was used to run Chi-square tests and least significance difference (LSD-t) on the data presented, and P value of less than 0.05 was regarded as statistically significant.</p><p><b>RESULT</b>The expression level of Nogo-A receptor in the control group was higher than that of the other groups at different time point (t value was 5.48, 6.11, 6.96, 8.24, 5.99 and 5.34, respectively, and all P values were less than 0.05). There were no significant differences in Nogo-A receptor level among the HIBD group, the GM-1 group and the NEP1-40 at 24 hours (t was 1.48, 2.76 and 1.29, respectively, and all P > 0.05), while the expression of Nogo-A receptor of NEP1-40 at 72 hours and 7 days was lower than that of the HIBD group and the GM-1 group at the same time point, respectively (all P < 0.05). Repair of neurons in damaged brain to some extent was found after GM-1 treatment and satisfactory repair of neurons and axon regeneration was obtained with NEP1-40 administration as shown by TEM.</p><p><b>CONCLUSION</b>Hypoxic ischemic brain damage can down-regulate the expression of Nogo-A receptor in the central nervous system. NEP1-40 contributes to the regeneration of axon and repair of brain damage, thus exerts neuroprotective effect.</p>

Research on the mechanism of Zuogui Pill and Yougui Pill in promoting axonal regeneration in model rats of autoimmune encephalomyelitis / 中国结合医学杂志

<p><b>OBJECTIVE</b>To study the molecular mechanism of Zuogui Pill (ZGP) and Yougui Pill (YGP) on axonal regeneration in rats with experimental autoimmune encephalomyelitis (EAE).</p><p><b>METHODS</b>EAE rat model was established by bilateral rear pedes subcutaneous injection of antigen made by mixing myelin basic protein (MBP) and complete Freud's adjuvant (CFA) in the volume ratio of 1:1. The pathological changes of axonal injury and regeneration in the brain and the spinal cord were observed on the 14th (the acute stage) and the 28th day (the remission stage) after modeling, with hematoxylin-eosin (HE) staining, silver stain, and immunohistochemical staining. The rats treated with prednisone acetate were taken as controls.</p><p><b>RESULTS</b>Observation under the light microscope with HE staining showed a sleeve-like change in rats' cerebrospinal parenchyma with inflammatory cell infiltration around the small vessels and neuronic denaturation, while silver staining showed excessive tumefaction and abscission of axon, and immunohistochemical analysis showed decreasing of nerve growth factor (NGF) expression at the acute stage of EAE, which was even more remarkable at the remission stage, showing significant difference as compared with the normal control (P<0.05). And the expressions of Nogo A, an axon growth inhibitor, and its receptor (Nogo-66 receptor, Ng R) were significantly higher than those in the normal control at the acute stage (P<0.01). However, after the intervention of ZGP and YGP, the pathological changes and axon damage in rats' brain and spinal cord were much more alleviated, and the NGF expression was significantly higher than that in the model group at the acute stage (P<0.05). The expression of NGF was even stronger during the remission stage, and a better effect was shown by YGP. As for Nogo A and Ng R expressions, they were significantly lower than those in the model group at the acute stage (P<0.05), but a better effect was shown by ZGP.</p><p><b>CONCLUSIONS</b>ZGP and YGP can prevent axonal injury and promote the axonal regeneration in rats of EAE, and the possible mechanism is to increase the expression of NGF and reduce the expression of Nogo A and its receptor. However, some differences are observed between the two Chinese preparations in their acting times and points, which provides a certain basis for revealing the modern connotation of the Chinese medicine theory on tonifying Shen ()-yin and Shen-yang.</p>

Lentiviral vector-mediated RNA interfere gene Nogo receptor to repair spinal cord injury / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the effects of lentiviral vector-mediated RNA interfere gene Nogo receptor (NgR) of rat cortical neurons in repairing spinal cord injury.</p><p><b>METHODS</b>The recombinant-lentiviral vector with small inferring RNA siNgR199 which had been constructed was transfected into rat cortical neuron cells in vitro in 3 multiplicity of infection (MOI). The infection rate was determined with fluorescent microscope, and the target gene was detected by PCR analysis. Then, the recombinant was injected into the cortical motor area of the rats with severe spinal cord injury, and the saline was also injected into other rats with severe spinal cord injury as a match control. The functional recovery of the rats' hindlimb was assessed using BBB score and the nerve fiber of the injured region was observed by nerve tracing.</p><p><b>RESULTS</b>The rate of recombinant infecting rat cortical neuron in vitro exceeded 99%. PCR analysis confirmed that the effect of lentiviral vector-mediated RNA interfering gene NgR of rat cortical neurons in vitro was 61%. Although all rats with spinal cord injury were observed to have the hindlimb functional recovery, these rats injected with recombinant had better hindlimb functional recovery than others showing by more BBB score (P < 0.01). Moreover, it was found that some nerve fiber passed the injured spinal cord region of the rats which were injected with recombinant.</p><p><b>CONCLUSION</b>The recombinant lentiviral vector with siNgR199 which had been constructed is able to promote the growth of nerve fiber and the functional recovery of the rats' hindlimb.</p>

Effect of phenylalanine on the Nogo-66 receptor expression in the cortical neurons of rats / 中国当代儿科杂志

<p><b>OBJECTIVE</b>This study examined the effect of high concentration of phenylalanine (Phe) on Nogo-66 receptor (NgR) expression in the cortical neurons of rats in vitro in order to investigate whether NgR is involved in the etiology of Phe-induced brain damage.</p><p><b>METHODS</b>Neurons from the cerebral cortex of embryonic rats were cultured for 3 days and then were treated with 0.9 mM Phe. After 12, 24 and 48 hrs of Phe treatment, mRNA and protein expression of NgR was detected by real-time PCR and Western blot respectively. Growth cones and growth axons of neurons were detected by immunofluorescence and immunohistochemistry respectively after 12 and 24 hrs of Phe treatment.</p><p><b>RESULTS</b>The length of growth axons of neurons was significantly shorter after 12 and 24 hrs of Phe treatment compared with the control group without Phe treatment (P<0.05). Growth cones collapse occurred in 12.5+/-9.7% and 24.1+/-4.5% of neurons respectively after 12 and 24 hrs of Phe treatment but only in 3.5+/-1.5% in the control group (P<0.01). The protein level of NgR after 12, 24 and 48 hrs of Phe treatment was up-regulated, with 9.0, 9.4 and 12.6 times as the control. mRNA level of NgR in the Phe treatment group did not differ from control.</p><p><b>CONCLUSIONS</b>High concentration of Phe can induce an increased NgR protein expression in cortical neurons, and the increased NgR expression may contribute to the growth cones collapse and the inhibitory activities of axon regeneration after injury.</p>

NgR expression in oligodendrocyte precursor cells and its changes after oxygen & glucose deprivation in neonatal rats / 中国当代儿科杂志

<p><b>OBJECTIVE</b>This study examined the NgR expression in oligodendrocyte precursor cells (OLPs) and its changes after oxygen & glucose deprivation (OGD) in order to explore the role of NgR expression in the regeneration of OLPs after OGD in neonatal rats.</p><p><b>METHODS</b>The OLPs from 2-day-old neonatal rats were separated by improved separation and purification through agitation and then cultured in chemically defined medium. OLPs OGD model was prepared using the medium consisting of Na2S2O4 and Earle's fluid in vitro. Immunofluorescence assay was applied to identify the OLPs with its specific antibodies such as A2B5, O4 and O1. Western blot was used to detect the NgR expression in OLPs 10 and 30 minutes after OGD. The livability rate of cells was detected by MTT.</p><p><b>RESULTS</b>NgR expression was found in both the cell body and the prominence of purified OLPs. NgR expression in OLPs increased significantly 10 and 30 minutes after OGD compared with that in OLPs without OGD (controls, P < 0.05). MTT showed that the livability rate of OLPs at 30 minutes following OGD was significantly lower than that of controls (65.97+/-3.69% vs 97.17+/-6.88%, P < 0.05).</p><p><b>CONCLUSIONS</b>NgR is expressed in both the cell body and the prominence of OLPs. NgR expression increases while cell livability decreases following OGD, suggesting that NgR may play a role in the inhibition of regeneration of OLPs.</p>