OBJECTIVETo explore the effect of kallikrein-binding protein (KPB) in protecting retinal ganglion cells (RGCs) and promoting axonal regeneration following optical nerve injury in rats.

METHODSCrush injury of the optic nerve at 0.5-1.0 mm from the eyeball was induced in rats, which received subsequent KBP injection into the vitreous cavity (experimental group) and PBS injection (control group). At 7, 14 and 21 days after the injury, the rats were sacrificed and frozen sections of the eyeball were prepared to observe the structure and thickness of the retina and count the number of survival RGCs with HE staining. The optic nerves were collected for Western blotting to assess the effect of KBP on the RGCs and axonal regeneration.

RESULTSRGC counts and retinal thickness showed significant differences between the two groups. Western blotting also demonstrated a significant difference in the expression of the nerve regeneration marker protein GAP-43 between the two groups.

CONCLUSIONKBP offers protection on RGCs and promotes regeneration of the optic nerve axons after optic nerve injury in rats.

Animals ; Axons ; physiology ; Female ; GAP-43 Protein ; metabolism ; Nerve Regeneration ; drug effects ; physiology ; Neuroprotective Agents ; pharmacology ; Optic Nerve Injuries ; drug therapy ; Rats ; Rats, Sprague-Dawley ; Retinal Ganglion Cells ; drug effects ; physiology ; Serpins ; pharmacology

Netrin is a neuronal guidance molecule implicated in the development of spinal commissural neurons and cortical neurons. The attractive function of netrin requires the receptor, Deleted in Colorectal Cancer (DCC), while the receptor Unc5h is involved in the repulsive action of netrin during embryonic development. Although the expression of netrin and its receptor has been demonstrated in the adult nervous system, the function of netrin in adult neurons has not yet been elucidated. Here, we show that netrin treatment inhibited neurite outgrowth of adult dorsal root ganglion (DRG) neurons in explant and dissociated cultures. In addition, unc5h1-3 mRNAs, but not the dcc mRNA, are abundantly expressed in the adult DRG. An in situ hybridization study demonstrated that unc5h mRNAs were expressed in DRG neurons. This finding indicates that netrin/Unc5h signaling may play a role in the neurite outgrowth of adult DRG neurons and that netrin may be involved in the regulation of peripheral nerve regeneration.
Animals ; Axons/*drug effects/physiology ; Cells, Cultured ; Ganglia, Spinal/cytology/drug effects/metabolism ; Gene Expression/drug effects ; In Situ Hybridization ; Male ; Nerve Growth Factors/*pharmacology ; Nerve Regeneration/drug effects ; Neurites/drug effects/physiology ; Neurons/*drug effects/metabolism/physiology ; RNA, Messenger/genetics/metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, Cell Surface/genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Time Factors ; Tissue Culture Techniques ; Tumor Suppressor Proteins/*pharmacology

In this study, we prepared PLLA/bpV(pic) microspheres, a bpV(pic) controlled release system and examined their ability to protect nerve cells and promote axonal growth. PLLA microspheres were prepared by employing the o/w single emulsification-evaporation technique. Neural stem cells and dorsal root ganglia were divided into 3 groups in terms of the treatment they received: a routine medium group (cultured in DMEM), a PLLA microsphere group (DMEM containing PLLA microspheres alone) and a PLLA/bpV(pic) group [DMEM containing PLLA/bpV(pic) microspheres]. The effects of PLLA/bpV(pic) microspheres were evaluated by the live-dead test and measurement of axonal length. Our results showed that PLLA/bpV(pic) granulation rate was (88.2±5.6)%; particle size was (16.8±3.1)%, drug loading was (4.05±0.3)%; encapsulation efficiency was (48.5±1.8)%. The release time lasted for 30 days. In PLLA/bpV(pic) microsphere group, the cell survival rate was (95.2 ±4.77)%, and the length of dorsal root ganglion (DRG) was 718±95 μm, which were all significantly greater than those in ordinary routine medium group and PLLA microsphere group. This preliminary test results showed the PLLA/bpV(pic) microspheres were successfully prepared and they could promote the survival and growth of neural cells in DRG.
Animals ; Axons ; drug effects ; physiology ; Cells, Cultured ; Delayed-Action Preparations ; chemistry ; pharmacokinetics ; pharmacology ; Drug Compounding ; Female ; Ganglia, Spinal ; drug effects ; metabolism ; physiology ; Immunohistochemistry ; Lactic Acid ; chemistry ; pharmacokinetics ; pharmacology ; Microscopy, Electron ; Microspheres ; Neural Stem Cells ; drug effects ; physiology ; Neurofilament Proteins ; metabolism ; Neurons ; drug effects ; metabolism ; Organometallic Compounds ; chemistry ; pharmacokinetics ; pharmacology ; Polyesters ; Polymers ; chemistry ; pharmacokinetics ; pharmacology ; Pregnancy ; Rats

OBJECTIVETo investigate the effects of combination therapy with methylprednisolone (MP) and brain-derived neurotrophic factor (BDNF) on axonal remyelination and functional recovery after spinal cord injury in rats.

METHODSForty-five rats were randomly divided into three groups: Group A received MP and BDNF; group B received MP and cerebrospinal fluid (CSF); and group C received CSF only. Contusion injury to adult rat spinal cord was produced at the T(10) vertebra level followed by immediate intravenous MP or CSF, and was thereafter infused intrathecally with BDNF or CSF for 6 weeks. Axonal remyelination and functional recovery was observed using RT-PCR, immunohistochemistry and open field locomotion.

RESULTSAn increase of 28.4% +/- 2.3% in the expression of proteolipid protein (PLP) gene, an endogenous indicator of axonal remyelination, was demonstrated in group A 24 hours after injury. Ten weeks later, there were significant decreases in hematogenous inflammatory cellular infiltration in groups A and B compared to C (P < 0.05). Concomitantly, a significant amount of axonal remyelination was observed in group A compared to groups B and C (P < 0.05). Furthermore, combination therapy using MP and BDNF in group A resulted in stimulation of hindlimb activity as well as improvement in the rate of functional recovery in open field locomotion (P < 0.05).

CONCLUSIONSCombined therapy of MP and BDNF can improve functional recovery through mechanisms that include attenuating inflammatory cellular infiltration and enhancing axonal remyelination at the injury site. Such a combination may be an effective approach for treatment of spinal cord injury.

Animals ; Axons ; physiology ; Brain-Derived Neurotrophic Factor ; administration & dosage ; Drug Therapy, Combination ; Female ; Methylprednisolone ; administration & dosage ; Myelin Proteolipid Protein ; genetics ; Nerve Regeneration ; drug effects ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley ; Recovery of Function ; Spinal Cord Injuries ; drug therapy ; metabolism ; physiopathology

OBJECTIVETo study the effects of intranigral injection of different doses of CuSO4.5H2O on dopaminergic neuron in the nigrostriatal system of rats.

METHODSWistar rats were divided into four groups, including control group, 10 nmol, 50 nmol and 200 nmol copper injected into left substantia nigra (SN) groups. Seven days after the intranigral injection of copper, dopamine (DA) contents in the striatum (Str) were measured by high performance lipid chromotophotography (HPLC); the density of tyrosine hydroxylase (TH) positive axons in the Str was measured by TH staining method; TH and Caspase-3 mRNA expression in the SN were measured by semi-quantitative RT-PCR. We detected the activity of superoxide dismutase (SOD) in the lesioned midbrain of rats using biochemical methods.

RESULTSDA and its metabolites contents had no significant difference between control group and low dose (10 nmol) copper group. But from 50 nmol copper group, DA contents in the lesioned sides were reduced with the increase in the copper doses injected, showing a significant linear correlation (F = 34.16, P < 0.01). In the 50 nmol copper group, TH positive axons in the Str decreased compared with those of the control and unlesioned sides (F = 121.9, P < 0.01). In the 50 nmol copper group, TH mRNA expression decreased (t = 3.12, P < 0.01) while Caspase-3 mRNA expression increased (t = 8.96, P < 0.01) in the SN compared with the control. SOD activity decreased in the midbrain of rats treated with 50 nmol copper compared with that of the control (t = 2.33, P < 0.01).

CONCLUSIONCopper could induce damage of dopaminergic neurons in the SN of rats through destroying antioxidant defenses and promoting apoptosis.

Animals ; Apoptosis ; drug effects ; physiology ; Axons ; drug effects ; metabolism ; pathology ; Caspase 3 ; drug effects ; genetics ; metabolism ; Copper ; toxicity ; Corpus Striatum ; drug effects ; metabolism ; pathology ; Dopamine ; metabolism ; Dose-Response Relationship, Drug ; Male ; Nerve Degeneration ; chemically induced ; metabolism ; pathology ; Neural Pathways ; drug effects ; metabolism ; pathology ; Neurons ; drug effects ; metabolism ; pathology ; Neurotoxins ; toxicity ; Oxidative Stress ; drug effects ; physiology ; Parkinsonian Disorders ; chemically induced ; metabolism ; physiopathology ; RNA, Messenger ; drug effects ; metabolism ; Rats ; Rats, Wistar ; Substantia Nigra ; drug effects ; metabolism ; pathology ; Superoxide Dismutase ; drug effects ; genetics ; metabolism ; Superoxide Dismutase-1 ; Tyrosine 3-Monooxygenase ; drug effects ; genetics ; metabolism ; Wallerian Degeneration ; chemically induced ; metabolism ; pathology

OBJECTIVETo explore the effects of different concentration of catalpol on the cell survival and axonal growth of cortical neurons cultured in vitro from 24 h newly born rat.

METHODPrimary cultured cortical neurons from 24 h newly born rat were dissociated and cultured. The different concentration of catalpol and 1 mg mL(-1) citicoline were added to the culture plates for 48 h, and the final of catalpol concentration were 0.25, 0.5, 1, 2.5, 5 mg mL(-1), respectively. The cortical neuron was identified by NF-200 antigen and its survival activity detected by MTT assay. The axonal growth of cultured cortical neuron were observed by inverted microscopy with micrometer.

RESULTImmunocytochemistry demonstrated more than 95% of the primary cultured cortical neurons were positive for NF-200 antigen, which indicated the cultured cells were neurons. Neurons survived growing on the concentration of 0.25, 0.5, 1, 2.5, 5 mg mL(-1). Compared with blank and 1 mg mL(-1) citicoline group,neurons survival rates were not statistical significant difference. However, it demonstrated that catalpol significantly promoted axonal growth from 1-5 mg mL(-1) (P <0.05). Interestedly, compared with the dose of 2.5 mg mL(-1), axonal growth was shorter at the dose of 5 mg mL(-1), and 2.5 mg mL(-1) catalpol showed the strongest promotion effect.

CONCLUSIONThe catalpol can enhance cortical neuron axonal growth, but not promote cortical neuron survival.

Animals ; Animals, Newborn ; Axons ; drug effects ; physiology ; Cell Survival ; drug effects ; Cells, Cultured ; Cerebral Cortex ; cytology ; Dose-Response Relationship, Drug ; Drugs, Chinese Herbal ; isolation & purification ; pharmacology ; Glucosides ; isolation & purification ; pharmacology ; Iridoid Glucosides ; Iridoids ; isolation & purification ; pharmacology ; Neurons ; cytology ; drug effects ; Neuroprotective Agents ; isolation & purification ; pharmacology ; Plants, Medicinal ; chemistry ; Rats ; Rats, Sprague-Dawley ; Rehmannia ; chemistry

OBJECTIVETo culture interleukin-1beta (IL-1beta)-activated Schwann cells (SCs) with human hair keratins (HHKs) for artificial nerve bridge construction.

METHODSSCs purified by primary culture with or without IL-1beta activation were cultured with HHKs decorated by extracellular matrix (ECM), and the artificial nerve bridge was implanted into the defect of rat sciatic nerve. The morphology of the SCs cultured with HHKs was monitored by inverted microscope, scanning electron microscope and evaluated by immunocytochemical staining, and the expression of nerve growth factor (NGF) in the sciatic nerve was observed by in situ hybridization.

RESULTSActivated SCs showed better ability to adhere to the HHKs and grew well. The HHKs component in the artificial nerve bridge underwent degradation in the sciatic nerve defect after 3 to 4 weeks, and IL-1beta activation resulted in enhanced NGF expression in the SCs.

CONCLUSIONThe constructed artificial nerve bridge by three-dimensional culture of IL-1beta-activiated SCs with HHKs decorated by ECM promotes the repair of sciatic nerve defects and accelerates sciatic nerve regeneration.

Animals ; Animals, Newborn ; Axons ; physiology ; Cell Culture Techniques ; Cell Movement ; physiology ; Cells, Cultured ; Hair ; chemistry ; Humans ; Interleukin-1beta ; pharmacology ; Keratins ; pharmacology ; Microscopy, Electron, Scanning ; Nerve Growth Factor ; biosynthesis ; Nerve Regeneration ; drug effects ; Rats ; Rats, Sprague-Dawley ; Schwann Cells ; drug effects ; metabolism ; ultrastructure ; Sciatic Nerve ; injuries ; physiopathology ; surgery ; Tissue Engineering ; methods

OBJECTIVETo study the molecular mechanism of Zuogui Pill (ZGP) and Yougui Pill (YGP) on axonal regeneration in rats with experimental autoimmune encephalomyelitis (EAE).

METHODSEAE 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.

RESULTSObservation 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.

CONCLUSIONSZGP 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.

Animals ; Axons ; drug effects ; metabolism ; pathology ; physiology ; Brain ; drug effects ; metabolism ; pathology ; Disease Models, Animal ; Drug Evaluation, Preclinical ; Drugs, Chinese Herbal ; administration & dosage ; pharmacology ; Encephalomyelitis, Autoimmune, Experimental ; drug therapy ; metabolism ; pathology ; GPI-Linked Proteins ; Male ; Myelin Proteins ; metabolism ; Nerve Growth Factor ; metabolism ; Nerve Regeneration ; drug effects ; Nogo Proteins ; Nogo Receptor 1 ; Rats ; Rats, Inbred Lew ; Receptors, Cell Surface ; Receptors, Peptide ; metabolism ; Research ; Signal Transduction ; drug effects ; Tablets