Fracture healing has long been a major concern for orthopedists.Currently,about 10% of fracture patients still have poor fracture healing or bone nonunion.In recent years,research has found that nerve growth factor(NGF)can promote fracture healing.This article reviews the mechanism and research progress of NGF in promoting fracture healing.NGF can promote vascular regeneration and nerve growth at callus and plays an important role in the proliferation and migration of bone cells.New animal experiments and clinical trials have confirmed the role of NGF in promoting fracture healing and further revealed its possible mechanism of action.Further research on NGF can provide new ideas for promoting fracture healing,especially for treating nonunion.
Animals ; Fracture Healing ; Humans ; Nerve Growth Factor

OBJECTIVETo investigate the role of p75 neurotrophin receptor (p75NTR) in the regeneration of facial nerve crush injury.

METHODSIn p75NTR knockout mice and wild type mice, the regenerating fibres in the facial nerve were also labelled by an anterograde tracer cholera toxin B (CTB). The next day after injury of facial nerve, CTB was injected into the trunk of the nerve in the proximal side of the crush, and then anterograde tracing and immunohistochemistry were used to examine the regeneration of axons after facial nerve crush injury. In p75NTR knockout mice and wild type mice, the facial nerves on one side were crushed and regenerating neurons in the facial nerve nucleus were labelled by Fast Blue. The facial nerve trunk was cut in the bifurcated region in the 4th day after injury and the stump was inserted into a small polymer tube containing Fast Blue. Retrograde tracing and labling motoneuron counting were used to examine the survival of motoneurons in the facial nerve nucleus after facial nerve crush injury.

RESULTSThe results showed that the axonal growth of injured axons in the facial nerve of p75NTR knockout mice was significantly retarded. The number of regenerated neurons in the facial nerve nucleus in p75NTR knockout mice was significantly reduced (P < 0.05). Immunohistochemical staining of regenerating axons also showed the reduction in nerve regeneration in p75NTR knockout mice (P < 0.01).

CONCLUSIONp75NTR plays an important role in the regeneration of injured peripheral nerves after injury.

nerve tissues, were still unclear. This study observed the histological changes and the expression of nerve growth factor (NGF) in the inferior alveolar nerve (IAN) after distraction osteogenesis. Unilateral mandibular distraction (0.5 mm twice per day for 10 days) was performed in eight mongrel dogs. Two animals were sacrificed at 7, 14, 28 and 56 days after completion of distraction, respectively. The distracted IAN and contralateral control nerve were harvested and processed for histological and innunohistochemical examinations. The signs of acute nerve injuries, such as demyelination and partial discontinuation of nerver fiber, were observed in the distracted IAN on 7 and 14 days after distraction. The initial remyelination and regeneration of distracted IAN were showed at 14 days after completion of distraction. At 56 days later, the histologic features of distracted IAN was similar to those of the normal control IAN. The expression of NGF was significantly increased in most distracted nerve tissues on 7, 14 and 28 days after distraction. On 56 days after distraction, the expression of NGF returned to the normal level. This study suggested that the acute IAN injury caused by mandibular distraction were mostly recovered during consolidation period. The NGF was seemed to be induced from Schwann cell and damaged nerve tissues, and it may have important roles in the initial healing of damaged nerves.]]>
Animals ; Congenital Abnormalities ; Demyelinating Diseases ; Dogs ; Mandibular Nerve ; Nerve Growth Factor ; Nerve Tissue ; Osteogenesis, Distraction ; Regeneration

No abstract available.
Animals ; Rats* ; Receptor, Nerve Growth Factor* ; Suprachiasmatic Nucleus*

Red Liriope platyphylla (RLP) has been manufactured from Liriope platyphylla (L. platyphylla, LP) roots using steaming process and investigated as a curative agent for treatment of diabetes, obesity and neurodegenerative disorders. To examine the precautionary effects of aqueous extract RLP (AEtRLP) on the preclinical stages of Alzheimer's Disease (AD), alterations of the key factors influencing AD were investigated in Tg2576 mice after AEtRLP7 treatment for 4 months. Abeta-42 peptides level was significantly decreased in the brain of AEtRLP7-treated Tg2576 mice compared to vehicle-treated Tg2576 mice, although significant differences on improving behavioral defects were not observed in the same group. The concentration of nerve growth factor (NGF) in serum was also higher in AEtRLP7-treated Tg2576 mice than vehicle-treated Tg2576 mice. However, the phosphorylation of TrkA and Erk among the downstream effectors of the high affinity NGF receptor was significantly lower in AEtRLP7-treated Tg2576 mice. A similar pattern was observed in the expression level of downstream effectors within low affinity NGF receptor. Overall, these results suggest that AEtRLP7 can contribute to preventing the production and deposition of Abeta-42 peptides during the early progression stage of AD in the brain of Tg2576 mice through increased NGF secretion.
Alzheimer Disease* ; Animals ; Brain ; Mice* ; Nerve Growth Factor* ; Neurodegenerative Diseases ; Obesity ; Peptides ; Phosphorylation ; Receptor, Nerve Growth Factor ; Steam

Humans ; Nerve Growth Factor ; physiology ; Pain ; physiopathology ; Pulpitis ; physiopathology ; Receptor, Nerve Growth Factor ; physiology ; Receptor, trkA ; physiology

BACKGROUND: Nerve growth factor (NGF) has been suggested to participate in tumor progression and it can interact with its receptor p75NGFR. In the present study, we investigated the expressions of NGF and p75NGFR in hepatocellular carcinoma (HCC). METHODS: We performed immunohistochemistry for NGF, p75NGFR and PCNA in 45 cases of HCCs, and examined the relationships between the clinicopathologic factors and the immunohistochemical results. RESULTS: NGF was detected in 84.4% (38/45) of the tumor cells and in 64.4% (29/45) of the non-tumorous hepatocytes. Furthermore, a NGF expression was present in 28.9% (13/45) of the endothelial cells in the HCCs, but in 80% (36/45) of the endothelial cells in the non-tumor liver tissue. The tumor cells were negative for p75NGFR in all the HCCs. Although a p75NGFR expression was present in all the nerve fibers in the non-tumor liver tissues, it was markedly reduced (42.2%; 19/45) in the HCCs and a p75NGFR expression was observed at the sinusoids or around the large vessels. The HCCs expressing NGF, either in the tumor cells or the endothelial cells, showed a larger size than those HCCs that didn't express NGF. The NGF positive tumors showed a tendency toward a higher PCNA-labeling index than did the negative tumors. CONCLUSIONS: The changed localization of the NGF expression and the decreased expression of p75NGFR are associated with hepatic carcinogenesis. We suggest that a NGF expression may contribute to the progression of HCC.
Carcinoma, Hepatocellular ; Endothelial Cells ; Hepatocytes ; Immunohistochemistry ; Liver ; Nerve Fibers ; Nerve Growth Factor ; Proliferating Cell Nuclear Antigen

OBJECTIVETo study the biological characteristics of p75 neurotrophin receptor positive (p75(NTR+)) tongue squamous cell carcinoma cells which were separated by flow cytometry cell sorting.

METHODSTo determine the biological characteristics of p75(NTR+) cells which were separated from Tca-8113 and Cal-27 tongue squamous cell carcinoma cells by flow cytometry cell sorting, including study the capacity of cloning, 3-(4,5)-demethylthiazo(z-y1)-3,5-diphenytetrazoliumromide (MTT) assay, wound healing assay. p75(NTR+) cells with non-sorted cells were as control group.

RESULTSIn Tca-8113 and Cal-27 tongue squamous cell carcinoma cell lines, the percentage of p75(NTR+) cells were 3.1% and 1.9%. Compared with p75(NTR+) cells with non-sorted cells, p75(NTR+) cells possess higher capacity of cloning (Tca-8113, P=0.024; Cal-27, P=0.009). The percentage of p75(NTR+) cells of the progeny cells generated from monoclonal p75(NTR+) cells decreased to 14.5% (Tca-8113) and 5.8% (Cal-27) after cultured two weeks. p75(NTR+) cells possessed higher proliferation ability and higher metastasis ability than non-sorted cells.

CONCLUSIONp75(NTR+) cells isolated from tongue squamous cell carcinoma have the characteristics of cancer stem cells.

OBJECTIVE: To investigate the effect of platelet-derived growth factor (PDGF) on nerve regeneration in peri-implant tissues. METHODS: SD rats with implants in their femurs were injected with PDGF solution. The effects of PDGF on nerve regeneration in peri-implant tissues were analyzed by immunohistochemical staining. RESULTS: PDGF increased the number of nerve fibers in peri-implant tissues at early stage. PDGF had no significant effect on the number of nerve fibers in peri-implant tissues at late stage. Moreover, these nerves had a typical structure of peripheral nerve fibers. CONCLUSIONS PDGF can promote nerve regeneration in peri-implant tissues at early stage. This study provided a certain experimental basis for the clinical application of PDGF to promote nerve regeneration and further improve the sensory function of the implant.
Animals ; Dental Implants ; Nerve Fibers ; Nerve Regeneration ; Platelet-Derived Growth Factor ; Rats ; Rats, Sprague-Dawley

BACKGROUND: The effect of chronic administration of 4-methylcatechol known as a neurotrophic factor inducer on the allodynia and spinal neurotrophic factors was investigated in chronic constrictive injury of sciatic nerve in rats. METHODS: With the Sprague Dawly rat, sciatic nerve was loosely ligated with 4-0 chromic catgut and neuropathic pain model was made. The threshold for tactile allodynia was measured with von Frey hair by up-down method and cold allodynia was measured by dropping 20microliter of 100% acetone on the dorsum of the injured foot. 4-Methylcatechol (100microgram/kg, intraperitoneal) was injected once a day for 14 days and the effect on allodynia was compared with saline injected group. At 3, 7 and 14 days after injection, lumbar spinal cord was harvested and the mRNA content of nerve growth factor (NGF) and brain derived neurotrophic factor (BDNF) was measure by real time PCR. RESULTS: Mechanical and cold allodynia improved from 7 days after 4-methylcatechol administration. NGF and BDNF in spinal cord decreased compared to sham operated group. BDNF in lumbar spinal cord has increased tendency after treatment without statistical significance. CONCLUSIONS: Chronic intraperitoneal administration of 4-methylcatechol may improve tactile and cold allodynia in chronic constrictive injury rat model of neuropathic pain. The BDNF mRNA in spinal cord might increase after 4-methylcatechol treatment.
Acetone ; Animals ; Brain-Derived Neurotrophic Factor ; Catechols ; Catgut ; Cold Temperature ; Foot ; Hair ; Hyperalgesia ; Nerve Growth Factor ; Nerve Growth Factors ; Neuralgia ; Rats ; RNA, Messenger ; Salicylamides ; Sciatic Nerve ; Spinal Cord