Animals ; Cochlea ; growth & development ; metabolism ; Female ; Guinea Pigs ; Male ; Nerve Growth Factor ; metabolism

PURPOSE: The expression of nerve growth factor-beta (NGF-beta) is related to cardiac nerve sprouting and sympathetic hyper innervation. We investigated the changes of plasma levels of NGF-beta and the relationship to follow-up heart rate variability (HRV) after radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF). MATERIALS AND METHODS: This study included 147 patients with AF (117 men, 55.8+/-11.5 years, 106 paroxysmal AF) who underwent RFCA. The plasma levels of NGF-beta were quantified using double sandwich enzyme linked immunosorbent assay method before (NGF-beta(pre)) and 1 hour after RFCA (NGF-beta(post-1hr)). HRV at pre-procedure (HRV(pre)), 3 months (HRV(post-3mo)), and 1 year post-procedure (HRV(post-1yr)) were analyzed and compared with plasma levels of NGF-beta. RESULTS: 1) The plasma levels of NGF-beta significantly increased after RFCA (20.05+/-11.09 pg/mL vs. 29.60+/-19.43 pg/mL, p<0.001). The patients who did not show increased NGF-beta(post-1hr) were older (p=0.023) and had greater left atrial volume index (p=0.028) than those with increased NGF-beta(post-1hr). 2) In patients with NGF-beta(pre) >18 pg/mL, low frequency components (LF)/high-frequency components (HF) (p=0.003) and the number of atrial premature contractions (APCs, p=0.045) in HRV(post-3mo) were significantly higher than those with < or =18 pg/mL. 3) The LF/HF at HRV(post-3mo) was linearly associated with the NGF-beta(pre) (B=4.240, 95% CI 1.114-7.336, p=0.008) and the NGF-beta(post-1hr) (B=7.617, 95% CI 2.106-13.127, p=0.007). 4) Both NGF-beta(pre) (OR=1.159, 95% CI 1.045-1.286, p=0.005) and NGF-beta(post-1hr) (OR=1.098, 95% CI 1.030-1.170, p=0.004) were independent predictors for the increase of LF/HF at HRV(post-3mo). CONCLUSION: AF catheter ablation increases plasma level of NGF-beta, and high plasma levels of NGF-beta(pre) was associated with higher sympathetic nerve activity and higher frequency of APCs in HRV(post-3mo).
Aged ; Atrial Fibrillation/physiopathology/*surgery ; Catheter Ablation/*methods ; Female ; *Heart Rate ; Humans ; Male ; Middle Aged ; Nerve Growth Factor ; Nerve Growth Factors ; Transforming Growth Factor beta/*metabolism ; Treatment Outcome

BACKGROUNDNerve growth factor (NGF) is well-known for its important role in the development and maintenance of the nervous system. Along with its neurotrophic role, NGF has been detected in the testis of mouse, rat and human, suggesting an additional non-neurotrophic effect in the male reproductive system. The expression of β-NGF in the undescended testes (cryptorchidism) has not been detected at present. The aim of this study was to evaluate the expression of β-nerve growth factor mRNA and protein in experimental cryptorchidism.

METHODSA unilateral mechanical cryptorchidism model in the Sprague-Dawley rat was established and the expression of β-NGF with histologic changes in experimental cryptorchidism were investigated using one step quantitative real-time reverse transcription-polymerase chain reaction, in situ hybridization histochemistry, immunofluorescence and hematoxylin-eosin staining.

RESULTSThe expression of β-NGF mRNA and protein were both significantly decreased in the development of unmarred testis and cryptorchidism-induced testis, and the decrease of β-NGF in cryptorchidism-induced testis was far greater than that in uninjured testis.

CONCLUSIONFrom this investigation, we confirmed a lower expression of β-NGF in undescended testes than in the development of testis.

Animals ; Cryptorchidism ; genetics ; metabolism ; Male ; Nerve Growth Factor ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the nerve growth factor (NGF) regulating the expression of calcitonin gene-related peptide (CGRP) in promoting the proliferation of osteoblast-like cell (MG-63) and thus illustrate the mechanism of the NGF in wound healing.

METHODSDifferent concentrations of NGF were used to stimulate MG-63. The expression of CGRP was detected by real-time quantitative polymerase chain reaction (RT-QPCR) and enzyme-linked immunosorbent assay after 1, 2, 3, and 4 days. The proliferation of MG-63 was detected by cell counting kit-8 (CCK-8). The expression of CGRP mRNA and the proliferation of MG-63 were then detected by RT-QPCR and CCK-8 after adding the NGF receptor blocker.

RESULTSCompared with the blank control group, the expression of CGRP significantly increased by stimulating the NGF. The expression of CGRP was positively related to the concentration of NGF (P<0.05). Moreover, the expression of CGRP increased by prolonging the NGF stimulation time. The proliferation of MG-63 increased after stimulating the NGF (P<0.05). After adding the NGF receptor blocker, the expression of CGRP and the proliferation of MG-63 correspondingly decreased (P<0.05).

CONCLUSIONNGF can up-regulate the expression of CGRP and increase the proliferation of MG-63. Therefore, NGF plays a significant role in wound healing.

Animals ; Calcitonin ; Calcitonin Gene-Related Peptide ; metabolism ; Cell Line ; Ganglia, Spinal ; Humans ; Nerve Growth Factor ; metabolism ; Rats, Sprague-Dawley ; Receptor, Nerve Growth Factor ; Signal Transduction ; Up-Regulation

TrkA is essential components of the high-affinity NGF receptor necessary to mediate biological effects of the neurotrophins NGF. Here we report on the expression of trkA in the cerebral cortex and diencephalon of mongolian gerbils during postnatal development. The expression of trkA was identified by immunohistochemical method. In parietal cortex and piriform cortex, higher levels of trkA-IR (immunoreactivity) were detected at 3 days postnatal (P3) and at P9. Although trkA was not expressed till P3 in the parietal cortex, it was detectable at birth in the piriform cortex. Several regions, such as Layers I, IV & VI, did not show much expression. Layer I showed especially weak labeling. In the hippocampus, thalamus, and hypothalamus, higher levels of trkA-IR were detected at P6 and P12 than earlier days. But trkA was not expressed at birth in the hippocampus, at P3 in the reticular thalamic nucleus (Rt), or neonatally in the dorsomedial hypothalamic nucleus (DM). This data shows that expression of trkA is developmentally regulated and suggests that high affinity neurotrophin-receptors mediate a transient response to neurotrophines in the cerebral cortex and diencephalon during mongolian gerbil brain ontogeny.
Animals ; Animals, Newborn ; Cerebral Cortex/*metabolism ; Diencephalon/*metabolism ; Gerbillinae/*metabolism ; Immunohistochemistry/veterinary ; Nerve Growth Factor/metabolism ; Receptor, trkA/*metabolism

OBJECTIVETo investigate the growth and development of nerve growth factor (NGF)-positive neurons in the cerebellum of midanaphase human fetus.

METHODSThe expression of the NGF-positive neurons in the cerebrum of human fetus was observed by immunohistochemical methods, and the integral absorbance (IA) was detected.

RESULTSBy the 3rd to 4th month of gestation, neurons was seen in the ependymal, central, and marginal plate of cerebellum; the nucleus was oval and the neurons had short and small processes. By the 5th to 7th month of gestation, the number of NGF-positive neurons increased, the expressions enhanced, the nucleus was round-, oval-, or fusiform-shaped, the neurons grew larger in size, and the Purkinje cells showed NGF-positive expression. By the 8th to 10th month of gestation, the NGF-positive expression was enhanced with deeper dying, the body of Purkinje cells grew larger gradually, and the number of NGF-positive neurons in the granular cell layer and molecular layer increased. IA of the cerebellar cortical neurons of the 3rd, 4th, 5th, 6th, 7th, and 8th month of gestation showed an increasing trend, and significant difference was observed (P < 0. 05).

CONCLUSIONNGF-positive neurons in the cerebellum play an important role for differentiation, proliferation, migration, and growth of neurons in the cerebellum.

Cerebellum ; cytology ; metabolism ; Fetus ; cytology ; metabolism ; Humans ; Nerve Growth Factor ; metabolism ; Neurons ; cytology ; metabolism ; Purkinje Cells ; metabolism

OBJECTIVE: To determine the expression and significance of p75NTR in the neuron and glia of dorsal root ganglia (DRG) in different injury models. METHODS: The models of sciatic nerve injury, spinal cord injury, and combined injury (sciatic nerve injury one week prior to spinal cord injury) were established. The rats were randomly divided into a normal group,a sciatic nerve injury group,a spinal cord injury group, and a combined injury group. The sensory neurons in the DRG were labeled by fast blue (FB) injected in the dorsal column of spinal cord 0.5mm rostral to the transection site. The expression of p75NTR in the neurons and glia of the DRG was examined with immunofluorescence histochemistry after different kinds of injury and its expression in the FB positive neurons was further observed with immunofluorescence histochemistry combined with FB retrograde labeling. RESULTS: The expression of p75NTR was increased in the glia, but was downregulated in sensory neurons in the sciatic nerve injury group compared with the normal group. p75NTR immunoreactive products were downregulated in the glia in the spinal cord injury group compared with the sciatic nerve injury group or the combined injury group. In the combined lesion animals, the expression of p75NTR was similar to that of the sciatic nerve injury group. Its expression in the sensory neurons of DRG was downregulated,but was upregulated in the glia. The majority of sensory neurons labeled by FB in the combined injury group were p75NTR-negative, but surrounded by p75NTR-positive glia. CONCLUSION p75NTR immunoreactive products in the glia and neurons of DRG have significant discrepancy after injury. The glial p75NTR in the DRG may play a role in the enhanced regeneration of acsending tract in the injured spinal cord after combined injury.
Animals ; Ganglia, Spinal ; metabolism ; pathology ; Male ; Neuroglia ; metabolism ; Neurons ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptors, Nerve Growth Factor ; metabolism ; Sciatic Nerve ; injuries ; metabolism ; Spinal Injuries ; metabolism

OBJECTIVE: To explore the effects of exogenous transforming growth factor-beta 1 (TGFbeta1) on peripheral nerve regeneration after the peripheral nerve injury and if TGFbeta1 regulates the expression of basic fibroblast growth factor (bFGF) in the anterior horn motoneurons of spinal cord during regeneration. METHODS: Forty-eight rats were crushed on the right sciatic nerve and then randomly divided into 2 groups: TGFbeta1 group and NS group. In TGFbeta1 group, TGFbeta1 50 microL (0.1 microg/mL) was injected into the proximal nerve near to the crushed nerve and after the operation the injured leg was injected with equal TGFbeta1 whereas the NS was replaced in the NS group. The rats of each group survived for 3, 7, 14 and 21 days after the lesion. The bFGF expression in the anterior horn motoneurons of spinal cord was detected by immunohistochemistry (IHC). Semi-thin section and Fast Blue retrograde tracing were also performed with the rats surviving for 21 days to observe the regeneration of distal end in the injured right sciatic nerve. RESULTS: The number of bFGF immunoreactive positive motoneurons in TGFbeta1 group was obviously higher than that of the NS group (P < 0.05). In the distal sciatic nerve of the rats treated with TGFbeta1, the number and diameter of regenerating myelinated axons and the thickness of myelinated sheath were more than those of the NS group (P < 0.05). The number of motoneurons in spinal cord and neurons in dorsol root ganglia (DRG) labelled with Fast Blue in the NS group was obviously lower than in the TGFbeta1 group (P < 0.01). CONCLUSION Exogenous TGFbeta1 plays an important role in promoting the peripheral nerve regeneration; TGFbeta1 up-regulates the bFGF expression in the anterior horn motoneurons of spinal cord during the peripheral nerve regeneration.
Animals ; Female ; Fibroblast Growth Factor 2 ; biosynthesis ; genetics ; Male ; Motor Neurons ; metabolism ; Nerve Regeneration ; drug effects ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Sciatic Nerve ; injuries ; metabolism ; physiology ; Spinal Cord ; metabolism ; Transforming Growth Factor beta ; pharmacology ; Transforming Growth Factor beta1

OBJECTIVETo investigate the therapeutic effect of nerve growth factor (NGF) on changes of myelin basic protein (MBP) and functional repair of sensory and motor nerve following sciatic nerve injury.

METHODSThe sciatic nerves of rats were injured by sectioning with shaver,and divided into 3 groups: NGF group (Group A), group of normal saline solution (Group B), untreated group (Group C). The time point of observation was at the 4th week after operation. Sensory evoked potential (SEP) and motor evoked potential (MEP) were detected by Model WD-4000 nerve potential working diagnosis system. Immunohistochemical analysis was used for identification of MBP.

RESULTSThe latency of SEP in the Group A at the 4th week after operation was shorter than that in the Group B (P<0.05). The MEP was elicited in 76% of the Group A and was higher than that in the Group B. Results of immunohistochemistry showed that there were less MBP-positive cells in the Group A than in the Group B in one and four weeks respectively.

CONCLUSIONSNGF can improve the conductive function of injured peripheral nerve and facilitate regeneration of nerve.

Animals ; Evoked Potentials ; Female ; Immunohistochemistry ; Myelin Basic Protein ; metabolism ; Nerve Growth Factor ; pharmacology ; Peripheral Nerve Injuries ; Peripheral Nerves ; metabolism ; Rats ; Rats, Wistar ; Sciatic Nerve ; injuries ; metabolism

OBJECTIVE: To determine the expression of nerve growth factor (NGF), tyrosine kinase receptor A (trkA), and pan-neurotrophin receptor (p75) in the lung tissues in asthmatic rats, and to explore their effects on the airway inflammation. METHODS: Thirty-two SD rats were randomly divided into 4 groups: the control, asthma, NGF and anti-NGF groups. The asthmatic model was established by the inhalation and injection of ovalbumin. The total cell count and differential cell count in the bronchoalveolar lavage fluid (BALF) were performed. The pathologic changes in the lung tissues of the 4 groups was detected by HE staining. The NGF mRNA expression in the lung tissues of the asthma and control groups was determined by reverse transcription-polymerase chain reaction (RT-PCR). The changes of trkA and p75 mRNA expressions in the lung tissues in the 4 groups were also investigated by RT-PCR. RESULTS: Compared with the control group, the BALF total cell, the BALF eosinophils (Eos), and the BALF lymphocytes (Lyms) significantly increased (All P <0. 001) in the asthma group; and the lung tissues of the asthma group had more infiltrating inflammatory cells. Not only the expression of NGF mRNA, but also its receptors trkA and p75 mRNA in the lung tissues were significantly higher in the asthma group than those in the control group (All P < 0.01). Positive correlation was found between the expression of NGF mRNA and the BALF total cell, the BALF Lyms in the asthma group. Compared with the asthma group, the total cell, the Eos, and the lyms in BALF in the NGF group significantly increased (All P < 0.01), and the lungs of the NGF group had apparent inflammatory changes. The expre-ssions of p75 and trkA mRNA were enhanced significantly (All P < 0.05). Compared with the asthma group, the total cell, the Eos, and the lyms in BALF in the anti-NGF group significantly decreased (All P < 0.001), and the lungs of the anti-NGF group showed alleviative inflammatory changes. The expre-ssions of p75 and trkA mRNA significantly decreased (All P < 0.01). CONCLUSION In lungs of asthmatic rats, the elevated expression of NGF mRNA is closely related to the airway inflammation. NGF can upregulate the expressions of p75 and trkA mRNA in asthmatic rats, and then may promote their role in the airway neuronal inflammation in asthma.
Animals ; Asthma ; chemically induced ; metabolism ; Bronchitis ; metabolism ; Lung ; metabolism ; Male ; Nerve Growth Factor ; metabolism ; Ovalbumin ; RNA, Messenger ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptor, trkA ; metabolism ; Receptors, Nerve Growth Factor ; metabolism