1.Biological function of Nogo-B.
Wu-Jian XU ; Guo-Qing SHEN ; Qiang LI
Acta Physiologica Sinica 2013;65(4):445-450
Nogo-B is a major family member of the reticulon protein family 4. It is widely expressed in the central nervous system and peripheral tissues, and is mainly located in endoplasmic reticulum and cell membrane. Previous studies have revealed that Nogo-B plays a key role in vascular injury, tissue repair and inflammation process. It also may be critical for apoptosis of tumor cells and central diseases. Further investigation of the molecular characteristics and biological function of Nogo-B might be of great help to understand its role in diverse diseases.
Animals
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Apoptosis
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Cell Membrane
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physiology
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Endoplasmic Reticulum
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physiology
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Humans
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Inflammation
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Myelin Proteins
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physiology
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Nogo Proteins
2.Biological function of Nogo-B receptor.
Ying ZHU ; Li-Qun ZHANG ; Jian-Dong LI
Acta Physiologica Sinica 2022;74(2):301-308
Nogo-B receptor (NgBR) is a specific receptor of Nogo-B, a member of reticulon 4 protein family. It is widely expressed in many tissues and mainly located in cell membrane and endoplasmic reticulum. Previous studies have revealed that NgBR is involved in a variety of physiological and pathophysiological processes, such as dolichol synthesis, lipid metabolism, cholesterol trafficking, insulin resistance, vascular remodeling and angiogenesis, tumorigenesis and nervous system diseases. Further studies on the molecular characteristics and biological function of NgBR might be of great significance to understand its role in diverse diseases and provide possible clinical strategies for the treatment of diseases.
Carrier Proteins/metabolism*
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Endoplasmic Reticulum/metabolism*
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Lipid Metabolism
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Nogo Proteins/metabolism*
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Receptors, Cell Surface/metabolism*
4.Inhibition of Nogo expression to promote repair after spinal cord injury.
Hong-hui SUN ; Feng GAO ; Bin LIU ; Hai-tao YU ; Ning KONG ; Guo-min LIU
Chinese Medical Journal 2012;125(22):4044-4048
BACKGROUNDOne of the reasons for poor neuroregeneration after central nervous system injury is the presence of inhibitory factors such as Nogo. Here, we tested the inhibition of Nogo by RNA interference both in vitro and in vivo, using recombinant adenovirus-mediated transfection of short hairpin RNAs, to explore a new method of treatment for spinal cord injury.
METHODSWe designed and cloned two Nogo-specific short hairpin RNAs and an unrelated short hairpin RNA, packaged the clones into adenovirus, and amplified the recombinant virus in 293 cells. We then tested the inhibition of Nogo expression both in vitro in adenovirus-transfected oligodendrocytes and in vivo in spinal cord tissue from adenovirus-transfected spinal cord injury model rats. We tested Nogo expression at the mRNA level by reverse-transcription PCR and at the protein level by Western blotting and immunohistochemistry.
RESULTSIn vitro, the two specific Nogo short hairpin RNAs decreased Nogo mRNA expression by 51% and 49%, respectively, compared with Nogo expression in cells transfected with the unrelated control small hairpin RNA (P < 0.005). Similarly, Nogo protein expression decreased by 50% and 48%, respectively (P < 0.005). In vivo, in spinal cord injury model rats, the two specific Nogo short hairpin RNAs decreased Nogo mRNA expression by 45% and 40%, respectively, compared with Nogo expression in spinal cord injury model rats transfected with the unrelated control short hairpin RNA (P < 0.005). The Nogo protein level was similarly decreased.
CONCLUSIONSWe were successful in specifically downregulating Nogo at the mRNA and protein levels by adenovirus-mediated delivery of short hairpin RNAs, both in vitro and in vivo. This confirms the effectiveness of RNA interference for the inhibition of Nogo gene expression and the efficiency of using adenovirus for delivery. Thus gene therapy may be an effective treatment for spinal cord injury.
Adenoviridae ; genetics ; Animals ; Blotting, Western ; Humans ; Immunohistochemistry ; Myelin Proteins ; genetics ; metabolism ; Nogo Proteins ; RNA Interference ; RNA, Small Interfering ; genetics ; Rats ; Rats, Sprague-Dawley ; Spinal Cord Injuries ; therapy
5.Effects of electroacupuncture on the ultrastructure and the Nogo-A expressions in the cerebral cortex in rats with cerebral ischemia-reperfusion.
Yan-Qui LIANG ; Feng TAN ; Jie CHEN
Chinese Journal of Integrated Traditional and Western Medicine 2012;32(2):209-213
OBJECTIVETo observe the effects of electroacupuncture (EA) on the expressions of Nogo-A and the ultrastructure in the cerebral cortex at different time points after the cerebral ischemia-reperfusion in rats.
METHODSOne hundred and thirty male Sprague Dawley (SD) rats were randomly divided into the EA group (n = 30), the sham-EA group (n = 30), the model group (n = 30), the sham-operation group (n = 30), and the blank group (n = 10). The modified ZeaLonga method was used to prepare the left middle cerebral artery occlusion (MCAO) model in the first three groups. After the operation Baihui (DU20) and Dazhui (DU14) were daily needled in the EA group. One inch beside Baihui (DU20) and Dazhui (DU14) were daily needled in the sham-EA group. Rats in the model group were only treated with MCAO ischemia/reperfusion. Rats in the sham-operation group only received surgical wound. No treatment was given to rats in the blank group. The ultrastructures of ischemic cells and the intervention of the Nogo-A expressions were observed using the immunohistochemical staining and the transmission electron microscope 1, 7, and 28 days after EA.
RESULTS(1) In the EA group, the damage of ultrastructures of neurons, gliocytes, and blood brain barrier in the ischemic region was alleviated when compared with that of the sham-EA group and the model group. (2) On the 1st, 7th and 28th day after the cerebral ischemia-reperfusion, the expressions of Nogo-A in the ischemic cortex in the EA group was lower when compared with those in the sham-EA group and the model group at the corresponding time points, showing significant difference (P < 0.05). But there was no statistical difference between the sham-EA group and the model group at the same time point (P > 0.05).
CONCLUSIONThe mechanism of EA for protecting cerebral ischemia/reperfusion might be closely associated with alleviating the damage on the ultrastructures of brain cells, and down-regulating the expressions of Nogo-A.
Acupuncture Points ; Animals ; Brain Ischemia ; metabolism ; pathology ; therapy ; Cerebral Cortex ; metabolism ; ultrastructure ; Electroacupuncture ; Male ; Myelin Proteins ; metabolism ; Nogo Proteins ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; metabolism ; pathology ; therapy
6.Effects of Jisuikang on Nogo-NgR gene expression in spinal cord rats with injury.
Wu-Lin YOU ; Ya-Feng ZHANG ; Jian-Feng CHEN ; Heng YIN ; Jun-Feng YANG ; Jian-Wei WANG
China Journal of Orthopaedics and Traumatology 2015;28(3):235-239
OBJECTIVETo 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.
METHODSOne 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.
RESULTSThe 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).
CONCLUSIONThe 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.
Animals ; Female ; GPI-Linked Proteins ; analysis ; genetics ; physiology ; Medicine, Chinese Traditional ; Myelin Proteins ; analysis ; genetics ; physiology ; Nerve Regeneration ; drug effects ; Nogo Proteins ; Nogo Receptor 1 ; Rats ; Rats, Sprague-Dawley ; Receptors, Cell Surface ; analysis ; genetics ; physiology ; Signal Transduction ; drug effects ; Spinal Cord Injuries ; drug therapy ; metabolism
7.Functional interaction of the C-terminal of Nogo protein with connexin 26 and the expression of Nogo's mRNA in the murine inner ear.
Zi-an XIAO ; Ding-hua XIE ; Peng HU ; Kun XIA ; Fang CAI ; Qian PAN
Chinese Journal of Medical Genetics 2006;23(5):492-496
OBJECTIVETo screen and identify the proteins that interact with connexin 26 (CX26) and to analyze the expressions of these proteins in cochlea so as to explore the proteins that relate to the trafficking, assembly, localizing and gap junction functions of CX26.
METHODSThe whole coding region of GJB2 (CX26) gene was amplified from normal human genomic DNA by polymerase chain reaction (PCR) and then directionally subcloned into the vector pGBKT7 plasmid of the Match Maker Ga14 Two-Hybrid System 3 as a target to screen the interactive proteins of CX26 from the human fetal brain cDNA library by the yeast two hybrid technique. The false positive clones were discarded from the preys by repeated yeast two hybrid method between CX26 and everyone of the preys respectively. The DNAs of the insert of the identified positive clone were sequenced and BLAST analyzed against the GenBank. Lastly, the mRNA of the gene encoding the identified protein was analyzed in the murine inner ear by reverse transcription-polymerase chain reaction (RT-PCR).
RESULTSThe insert of one positive clone contained 867 bp with the former 525 bp being coding region. The DNA sequence and the open reading frame of the insert were identical to the 525 bp before the stop codes (including the stop codes) and the 238 bp after the stop codes of RTN4 gene which encoded Nogo protein. And the 174 amino acid residues encoded by the insert were those of the C-terminal of Nogo protein: Nogo-A, Nogo-B and Nogo-C. RTN4 mRNA expressed in the murine inner ear was confirmed by RT-PCR method.
CONCLUSIONThe C-terminal of Nogo protein interacts with CX26. Nogo protein expresses in the inner ear and may take part in the trafficking of CX26 or CX26 gap junction function.
Animals ; Base Sequence ; Connexin 26 ; Connexins ; genetics ; metabolism ; Ear, Inner ; metabolism ; Gene Expression ; Humans ; Mice ; Molecular Sequence Data ; Myelin Proteins ; genetics ; metabolism ; Nogo Proteins ; Protein Binding ; RNA, Messenger ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Two-Hybrid System Techniques
9.NgR expression in oligodendrocyte precursor cells and its changes after oxygen & glucose deprivation in neonatal rats.
Jun TANG ; Yu-Jia YAO ; Lin ZHONG
Chinese Journal of Contemporary Pediatrics 2007;9(5):445-448
OBJECTIVEThis 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.
METHODSThe 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.
RESULTSNgR 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).
CONCLUSIONSNgR 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.
Animals ; Animals, Newborn ; Blotting, Western ; Cell Survival ; Cells, Cultured ; Fluorescent Antibody Technique ; GPI-Linked Proteins ; Glucose ; deficiency ; Hypoxia ; metabolism ; Myelin Proteins ; Nogo Receptor 1 ; Oligodendroglia ; chemistry ; Rats ; Rats, Sprague-Dawley ; Receptors, Cell Surface ; Receptors, Peptide ; analysis ; physiology ; Stem Cells ; chemistry
10.Effect of ventricle injection of Nogo-A antibody on neuronal regeneration following hypoxic-ischemic brain damage in the neonatal rat.
Xiao-Guang ZHOU ; Ren-Hong LIU ; Ai-Hua XIONG
Chinese Journal of Contemporary Pediatrics 2007;9(4):301-304
OBJECTIVENogo-A antibody IN-1 can neutralize Nogo-A, a neurite growth inhibitory protein, promoting axonal regeneration following lesions of the central nervous system (CNS) in adult rats. This study aimed to examine the effect of ventricle injection of Nogo-A antibody on neuronal regeneration in neonatal rats following hypoxic-ischemic brain damage (HIBD).
METHODSA model of neonatal HIBD was prepared by the ligation of the left common carotid artery, followed by 8% hypoxia exposure. Forty HIBD rats were randomly given a ventricle injection of 10 microL Nogo-A antibody IN-1 (IN-1 group) or 10 microL artificial cerebrospinal fluid (artificial CSF group) (n=20 each). Another 20 neonatal rats were sham-operated, without hypoxia-ischemia, and were used as the controls. The levels of Nogo-A and GAP-43 protein in the brain were measured by immunohistochemistry.
RESULTSThe number of immunohistory positive cells of Nogo-A in the brain in the IN-1 group (28.61+/-1.70) was obviously less than that in the artificial CSF (39.52 +/-1.40) and the sham-operated groups (32.78 +/- 1.87) (both P < 0.01). There were significant differences in the Nogo-A protein expression between the artificial CSF and the sham-operated groups (P < 0.01). The GAP-43 protein expression in the IN-1 group (31.14 +/- 1.88) was noticeably higher than that in the artificial CSF group (27.73 +/- 1.43 ) (P < 0.01). Both the IN-1 and the artificial CSF groups showed lower GAP-43 protein levels than the sham-operated groups (33.64 +/- 1.24) (both P < 0.01).
CONCLUSIONSNogo-A antibody can reduce the expression of Nogo-A protein in the brain and thus promote neuronal regeneration in neonatal rats following HIBD. An increased GAP-43 protein expression in the brain after Nogo-A antibody administration shows an enhanced neuronal regeneration in the neonatal rats following HIBD.
Animals ; Animals, Newborn ; Antibodies ; administration & dosage ; Brain Chemistry ; Female ; GAP-43 Protein ; analysis ; Hypoxia-Ischemia, Brain ; metabolism ; physiopathology ; therapy ; Immunohistochemistry ; Injections, Intraventricular ; Male ; Myelin Proteins ; analysis ; antagonists & inhibitors ; immunology ; Nerve Regeneration ; Nogo Proteins ; Rats ; Rats, Sprague-Dawley