神经生长因子在糖尿病足创面组织中的表达

目的研究神经生长因子(NGF)及其高亲和性的酪氨酸激酶-A受体(TrkA)在糖尿病足创面组织中的表达。方法 收集糖尿病足创面组织标本作为对照组,正常人皮肤及皮下软组织标本作为正常组,采用免疫组化的方法观察神经生长因子(NGF)及其高亲和性的TrkA受体的表达,酶联免疫吸附测定法(ELISA)测定NGF的含量。结果 对照组NGF含量为(66.299±10.204)pg/ml,与正常组NGF含量(35.015±4.671)pg/ml相比,差异有统计学意义(P=0.010)。结论 NGF及其高亲和性的TrkA受体在糖尿病足创面组织中表达的变化可能参与了创面的发生发展,是糖尿病足创面修复的影响因素之一。     

神经生长因子及其受体在前列腺癌中的表达

目的探讨神经生长因子(nerve growth factor,NGF)及其受体TrkA、p75在前列腺增生和前列腺癌中的表达。方法采用免疫组织化学SABC法检测前列腺良性增生10例、高分化8例、中分化14例和低分化23例石蜡包埋组织中NGF和TrkA、p75的表达。结果NGF和TrkA在前列腺增生、高分化癌、中分化癌、低分化癌中的均有表达;而p75在前列腺增生全部表达、高分化癌(8/4)、中分化癌(14/6)、低分化癌(23/3)中的表达呈逐渐降低趋势,其差异有显著性(p<0.05),前列腺增生与高分化癌、中分化癌、低分化癌相比差异均有显著性(p<0.05)。结论NGF和TrkA的表达与前列腺增生和前列腺癌进展无关。p75与前列腺癌恶性进展有关,p75表达减少在前列腺癌过程中起着重要的作用。     

心肌缺血大鼠心内神经节神经生长因子表达的变化

目的观察神经生长因子在急性心肌缺血大鼠心内神经节表达及其变化,探讨神经生长因子与心肌缺血的关系。方法采用免疫组织化学方法动态观察了正常大鼠以及大鼠冠状动脉结扎后1、6、12、24h心内神经节神经生长因子的表达及变化。结果各组大鼠的心内神经节均存在神经生长因子阳性神经元,并且神经生长因子阳性神经元的数目在冠状动脉结扎后1、6、12、24h后增多,表达也增强。结论心肌缺血大鼠心内神经节神经生长因子表达持续显著升高,提示神经生长因子可能参与心肌缺血的病变过程。     

Reciprocal changes in expression of mRNA for nerve growth factor and its receptors TrkA and LNGFR in brain of aged rats in relation to maze learning deficits

 Quantitative in situ hybridization was used to examine the expression of mRNA for nerve growth factor (NGF) and its receptors, p140Trk (TrkA) and p75LNGFR (LNGFR), in different brain regions of adult (3-month-old) and aged (27-month-old) Wistar rats. The brain regions studied were hippocampus (dentate gyrus, CA3 region), basal forebrain (medial septum, diagonal band) and caudate-putamen. Prior to hybridization histochemistry behaviorally impaired as well as severely impaired animals were selected from a large group of old rats according to their performance in the Morris water maze. The impaired rats showed longer escape latencies and, thus, implicitly impaired performance in the place version of the task, but did not differ from adult controls on the platform crossing measure registered during the spatial probe trial. The severely impaired rats were significantly impaired on both measures, both in comparison with the adult animals and in comparison with the impaired aged rats. Inspection of the hippocampus revealed no age- or performance-related changes in NGF mRNA levels. The overall expression of TrkA mRNA in basal forebrain and caudate was found to be decreased in the impaired (–20%) as well as the severely impaired aged rats (–17%). A significant increase in p75LNGFR mRNA was found in the basal forebrain of the impaired rats in comparison with the severely impaired aged rats (+35%) and adult animals (+33%). These findings show that age-related maze performance deficits are accompanied by a decrease in basal forebrain and striatal TrkA mRNA expression. The increase in basal forebrain LNGFR mRNA levels observed in impaired, but not severely impaired, aged rats may reflect an early manifestation of processes underlying age-related cognitive deficits and may constitute a restorative and/or compensatory mechanism, since these rats displayed fewer deficits in navigation of the maze. Received: 21 February 1996 / Accepted: 15 October 1996     

神经生长因子及其受体在宫颈原位癌中的表达

目的　探讨神经生长因子 (nervegrowthfactor ,NGF)及其受体 p75在宫颈原位癌中的表达及意义。 方法　采用免疫组织化学S P法检测宫颈鳞状上皮原位癌 30例、正常上皮组织 13例、中～重度不典型增生 13例和浸润癌 14例石蜡包埋组织中NGF和 p75的表达。 结果　NGF在宫颈鳞状上皮正常组、不典型增生组、原位癌组中的表达呈逐渐增高趋势 ,而浸润癌组的表达却下降 ,差异有显著性 (χ2 =9 90 6 ,P <0 0 5 ) ,正常组与不典型增生组、原位癌组相比差异均有显著性 (t =2 0 0 7,P<0 0 5 ;t=2 0 0 8,P <0 0 5 ) ,浸润癌组与不典型增生组、原位癌组相比差异均有显著性 (t =2 37,P <0 0 5 ;t =2 4 4 ,P <0 0 5 )。p75在宫颈鳞状上皮正常组、不典型增生组、原位癌组、浸润癌组中的表达呈逐渐降低趋势 ,其差异有显著性 (χ2 =18 5 6 8,P <0 0 1) ,浸润癌组与正常组、不典型增生组、原位癌组相比差异均有显著性 (t =2 5 6 ,P <0 0 5 ;t =2 5 6 ,P <0 0 5 ;t=2 6 5 ,P <0 0 5 )。结论　NGF的高表达是宫颈瘤变过程中的早期事件。p75与宫颈癌的恶性进展有关 ,p75表达减少在原位癌是维持现状还是进展为浸润癌过程中起着重要的作用     

Human mast cells express functional TrkA and are a source of nerve growth factor

Mast cells are the principal effector cells in IgE-dependent hypersensitivity reactions. Despite reports that rodent mast cells proliferate in the presence of nerve growth factor (NGF), human mast cells reportedly do not respond to this factor. To determine if human mast cells express the NGF receptors, TrkA tyrosine receptor and the low affinity NGF receptor (LNGFR), we first analyzed the mRNA expression by RT-PCR of TrkA and LNGFR in a human mast cell line (HMC-1) and in human mast cells cultured in the presence of stem cell factor. Both HMC-1 and cultured human mast cells were found to express TrkA but not LNGFR. TrkA protein was demonstrated by Western blot analysis of HMC-1 lysates. Using flow cytometric analysis and mast cell tryptase as a mast cell marker, both HMC-1 cells and cultured human mast cells were shown to co-express tryptase and TrkA. Treatment of mast cells with NGF resulted in phosphorylation of TrkA on tyrosine residues as detected by immunoblotting with an antiphosphotyrosine antibody. Furthermore, NGF induced the immediate early gene c-fos in HMC-1 cells. HMC-1 cells and cultured human mast cells were also found to express NGF mRNA, and conditioned medium from HMC-1 cells stimulated neurite outgrowth from chicken embryonic sensory ganglia in culture. This effect was blocked by anti-NGF. Thus, mast cells express functional TrkA and synthesize NGF, suggesting a mechanism by which NGF may act as an autocrine factor for human mast cells, and by which mast cells and nerves may interact.     

神经生长因子受体在垂体腺瘤中的表达

目的：探讨两种神经生长因子（ＮＧＦ）受体（ＴｒＫＡ和ｇｐ７５）在各类垂体腺瘤中的表达。方法：采用免疫细胞化学ＳＡＢＣ法,检测了４４例经病理证实的垂体腺瘤中两种ＮＧＦ受体的表达情况。结果：ＴｒＫＡ在垂体ＰＲＬ分沁腺瘤中的过度表达率６９．２％,而在其它类型垂体腺瘤中的过度表达率为１９．４％,两者比较差异有非常显著性（Ｐ〈０．００５）。ｇｐ７５在垂体ＰＲＬ分泌腺瘤中的过度表达率在４６．２％,而在其它类型     

Temporal pattern of nerve growth factor receptor expression in developing cochlear and vestibular ganglia in quail and mouse

Summary We have previously demonstrated the presence of specific receptors for nerve growth factor (NGF) in cochleovestibular ganglia of 72 h (stage 19–20) quail embryos, with a greater density of NGF receptors in the cochlear portion of the ganglion. The present study was conducted to determine the temporal pattern of NGF receptor expression in cochlear and vestibular ganglia throughout development, and was conducted in two species, quail and mouse. As in the quail, specific binding of¹²⁵I-NGF was detected in cochleovestibular ganglia of mouse embryos from an embryonic age equivalent to 72 h quail embryos (embryonic day 11, E11), with a similar concentration of¹²⁵I-NGF binding in the cochlear portion. Quantitative studies revealed that¹²⁵I-NGF binding continued to increase, in both cochlear and vestibular ganglia, for several days of development, and then began to decrease to minimal levels. Maximal levels were achieved at E7 in the quail, and E14 to E16 in the mouse, while minimal levels were reached by E13 in the quail, and E18 in the mouse. The level of¹²⁵I-NGF binding in cochlear ganglia was two to three times higher than in vestibular ganglia; a finding corroborated by radioautographic studies. In both quail and mouse, NGF receptors were more heavily concentrated in the ventromedial portion of the cochlear ganglion, adjacent to the cochlear duct; an area containing both support cells and peripheral neuronal processes. In the vestibular ganglion,¹²⁵I-NGF binding was more homogeneous, although small areas containing high densities of silver grains were observed. The presence of NGF receptors in cochlear and vestibular ganglia suggests that these ganglia may be responsive to and/or dependent upon NGF during their development.     

Developmental changes in nerve growth factor (NGF) binding and NGF receptor proteins trkA and p75 in the facial nerve

This study characterizes the temporal-spatial distribution of nerve growth factor (NGF) low (p75) and high-affinity (trkA) receptors in the facial nerve and geniculate ganglion (GG) of developing quail embryos (E-3 to E-14). We used ¹²⁵I-labeled NGF (¹²⁵I-NGF) to study binding dynamics in a temporal series of isolated primordia and an autoradiographic series of staged specimens to characterize the occurrence and distribution of NGF receptors in this cranial nerve and its ganglion. In addition, expression of trkA and p75 protein-like immunoreactivity in the facial nerve and GG was studied by Western blot, in order to distinguish between high- and low-affinity NGF receptors respectively. The quantitative study of binding show that isolated facial primordia ranging from E-3 to E-14 exhibit different levels of specific binding. High initial binding levels were observed on E-3 specimens, then an initial decrease on day 4 (E-4) followed by a steady increase from days E-4 to E-7. Maximum ¹²⁵I-NGF binding was achieved on E-7, followed by a steady decline in binding on days 8 (E-8) and 9 (E-9), reaching near background levels on day 10 (E-10) of development and until the oldest stage assayed (E-14). Most of the cells bearing NGF receptors appeared to be nonneuronal crest-derived cells, but some placode-derived neurons and motor fibers of the VIIth cranial nerve transiently expressed the ability to bind ¹²⁵I-NGF. The temporal pattern of p75 expression matches the pattern of quantitative binding of NGF, while the trkA expression is restricted to a few stages mainly E7 and E9, implying that most of the binding detected is via low-affinity receptors, except for a proportion of high-affinity receptors present at stages of maximum binding. This temporal pattern of NGF binding sites suggests that cells within the VIIth cranial nerve are responsive to and/or dependent upon NGF in vivo, so NGF may play a biological role during normal development of the facial nerve. In view of the developmental events that parallel the occurrence and type of NGF binding sites, we suggest that this role may be to modulate from earlier chemotaxis and cell proliferation to much later events, such as neuronal differentiation and neuron-glia interactions. The significance of these findings in regeneration during adult life remain to be investigated.     

158例肺癌表皮生长因子受体检测及其意义探讨

目的；探讨表皮生长因子受体（ＥＧＦＲ）在肺癌中的表达特征及其临床病理意义。方法：应用ＡＢＣ免疫组织化学法对１５８例肺癌组织进行ＥＧＦＲ检测。结果：非小细胞肺 ＥＧＦＲ阳性率为８０．６％，而小细胞肺癌的ＥＧＦＲ均为阴性，并发现非小细胞肺癌ＥＧＦＲ表达与癌的组织学类型、分化程度、生物行为、肿块大小和临床分期均无相关性。结论：检测肺癌的ＥＧＦＲ有助于鉴别小细胞肺癌和非小细胞肺癌，并认为关于ＥＧＦＲ可能是     

Frequent expression of 75 kDa nerve growth factor receptor and phosphotyrosine in human peripheral nerve tumours: an immunohistochemical study on paraffin-embedded tissues

One hundred and three benign, and 10 malignant peripheral nerve tumours were examined immunohistochemically for expression of 75 kDa nerve growth factor receptor (NGFR). In benign tumours NGFR was demonstrated at 61% in neurinoma, 71% in neurofibroma, 93% in neurofibromatosis and 90% in traumatic neuroma. Malignant neurogenic tumours were 100% positive for NGFR. Phosphotyrosine-immunoreactivity was detected in 76% of NGFR-positive tumours but the frequency of immunostained tumour cells was low. These results suggest that both benign and malignant peripheral nerve tumours express 75 kDa NGFR. The receptor seems to serve as growth signal transduction of the tumour cells in terms of phosphorylation of the tyrosine residue of the receptor or the target protein of the NGFR protein tyrosine kinase.     

Nerve growth factor and autophagy: effect of nasal anti-NGF-antibodies administration on Ambra1 and Beclin-1 expression in rat brain

Abstract

Nerve growth factor (NGF) exerts protective actions in the healthy and diseased nervous system. Intranasal administration is a suitable and safe strategy to deliver NGF to CNS neurons. We investigated whether nasal anti-NGF-antibody (ANA) administration affects neuronal autophagy, in view of its putative regulatory role in this process. We focused on olfactory bulbs (OB), neocortex (Cx), hippocampus (HF) and septal complex (SC), known to be NGF-responsive and autophagically active. Our combined molecular/morphological results demonstrate that intranasally administered ANA reaches brain NGF-target neurons and lowers the levels of endogenous NGF and its receptors. Treatment also affects – in a brain region-dependent manner – the expression of the autophagic proteins Beclin-1 and Ambra1, as well as that of proteins belonging to the Bcl2 family, namely Bax and Bcl-2, reflecting apoptotic dysregulation. This study provides a nongenetically modified, NGF-defective animal model, representing a suitable tool to investigate novel properties of the neurotrophin, especially in relation to autophagy.     

Immunocytochemical demonstration of nerve growth factor receptor (NGF-R) in developing human fetal teeth

Evidence is accumulating that nerve growth factor receptor (NGF-R or p75^NGFR) can mediate cell growth and differentiation of non-neuronal cells. NGF-R expression was studied in developing teeth of human embryos and fetuses between the 6th and 18th weeks of gestation, using a monoclonal mouse-anti-human NGFR antibody. In contrast to earlier findings in rodents, the NGF-R expression of the human dental papilla was found to be transient. NGF-R was present in the condensing ecto-mesenchymal cells of the dental papilla in the early cap stage tooth germ. In later developmental stages, a shift of the NGF-R expression from the papilla to the cytoplasmic membrane of the inner enamel epithelium (IEE) was demonstrated. As in rodent odontogenesis, the NGF-R immunoreactivity of the IEE remained until the odontoblasts started secretion of predentinal matrix in the late bell state. The mitotic activity in the IEE was detected by an antibody against proliferating cell nuclear antigen (PCNA) and showed that the NGFR expression of the IEE decreased as the cell proliferation ceased. We propose that NGF-R may, be involved in differentiational and/or proliferative events of human odontogenesis.     

Structure and organization of the humanTRKA gene encoding a high affinity receptor for nerve growth factor

Summary Nerve growth factor (NGF) induces neurite outgrowth and promotes survival of embryonic sensory and sympathetic neurons. TRKA, a receptor tyrosine kinase cloned from a human colon cancer was later found to be expressed in the nervous system and phosphorylated in response to NGF. Somatic rearrangement(s) of theTRKA gene (also designatedNTRK1) are responsible for formation of some oncogenes. Genetic defects in TRKA are responsible for a human disorder, congenital insensitivity to pain with anhidrosis (CIPA). We report here isolation and characterization of theTRKA gene which spans at least 23 kb and is split into 17 exons. Exon sizes range from 18 to 394 bp and intron sizes range from 170 bp to at least 3.3 kb. Sizes and boundaries of the exons were determined, and all the splice donor and acceptor sites conformed to the GT/AG rule. Approximately 1.2 kb of the 5′-flanking regions was sequenced, and putative regulatory elements were identified. These results will be useful for studies on the developmental and biological regulation of theTRKA gene and for further characterization of mutations in CIPA patients as well as elucidation of mechanisms responsible for rearrangement(s) observed in human tumors.     

Interaction of nerve growth factor with pheochromocytoma cells. Evidence for tight binding and sequestration

When the rat pheochromocytoma clonal cell line PC 12 is incubated with nerve growth factor a portion of the bound ligand does not dissociate from the cells in a medium free of nerve growth factor. This fraction is defined as tightly bound nerve growth factor and is further separable into trypsin sensitive and trypsin resistant compartments.These findings suggest that a series of events occur in which nerve growth factor is bound, sequestered and then taken into the cell. The tight binding of nerve growth factor is linearly dependent on cell density, raising the possibility of its participation in the increase in cell-to-cell and cell-to-substrate adhesivity that is mediated by nerve growth factor.     

Changes in nerve growth factor levels in dorsal root ganglia and spinal nerves in a rat neuropathic pain model

The purpose of this study was to measure the changes in levels of nerve growth factor (NGF) in dorsal root ganglia (DRG) and spinal nerves with the aim of investigating the role of NGF in a rat neuropathic pain model. Nerve injuries were made by tight ligation of the left L5 and L6 spinal nerves using 6-0 silk thread in male Sprague-Dawley rats. Before surgery and 1, 3, 5, 7, and 14 days after surgery, tissue samples collected included the L3-6 DRGs bilaterally, segments of the ipsilateral L5-6 spinal nerves proximal and distal to ligation sites, and corresponding sites of the contralateral L3-6 and the ipsilateral L3-4 spinal nerves. NGF levels in the DRGs of the injured spinal nerves (the left L5 and L6) did not change significantly from control values. The spinal nerve segments distal to ligation sites had higher levels of NGF than the control values. Unlesioned sites did not show any significant changes in NGF levels. The increase of NGF in distal segments of injured spinal nerves may be due to an accumulation of retrogradely transported NGF. The maintenance of NGF levels in the DRGs that had lost peripheral connections may reflect local synthesis after nerve injury.     

Immunohistochemical evaluation of the protein expression of nerve growth factor and its TrkA receptor in rat limbic regions following electroshock seizures

Repeated (but not acute) exposure to brief, non-injurious seizures evoked by minimal electroconvulsive shock (ECS) decreases neuronal death in limbic system and increases mRNA levels for nerve growth factor (NGF). Thus, the induction of NGF is a potential mechanism for the neuroprotection evoked by repeated ECS. The neuroprotective action of NGF is mediated by the TrkA receptor. This study determined whether repeated ECS exposure increased TrkA and NGF protein levels. To determine the functional significance of changes in these proteins, we compared the effects of ECS given daily either for 7 days (chronic ECS) or for 1 day (acute ECS). After chronic ECS, upregulation of both NGF and TrkA was found in perirhinal cortex, thalamus, and amygdala. In hippocampus, TrkA was upregulated in CA2, CA3 and CA4. NGF increase in hippocampus was found in CA1 and dentate gyrus. In frontal cortex and substantia innominata, an increase in NGF (but not in TrkA) was found. In most brain regions, TrkA and NGF remained unchanged after acute ECS. Our results demonstrate that repeated exposure to ECS causes an upregulation of TrkA and NGF proteins in several limbic areas in which neuroprotective effects are observed suggesting that NGF contributes to ECS-evoked neuroprotection.     

Effects of nerve growth factor and glucocorticoid on cultured human pheochromocytoma cells

Primary cell cultures of two human pheochromocytomas (PC) that were associated with high serum levels of adrenaline and noradrenaline were developed to study the effects of nerve growth factor (NGF) and dexamethasone on the morphology and function of PC cells in vitro. By phase-contrast microscopy, cultured cells were small and hyperchromatic on the first day of culture; neurite-like processes that extended to other cells developed several days later and were maintained for more than 3 months. NGF (100ng/ml), dexamethasone (10^–5M), or NGF + dexamethasone were added to the culture media 2 weeks after the cultured cells had stabilized. Catecholamine concentrations in the medium were maintained at higher levels after addition of NGF, dexamethasone, or NGF + dexamethasone as compared to control cells. In the presence of NGF, extension of neurite-like processes was clearly accelerated, while high levels of dexamethasone inhibited growth of processes. These in vitro studies showed that the addition of NGF or the removal of dexamethasone induces differentiation of adrenal neurons present in pheochromocytomas, suggesting that adrenocortical steroid hormones influence the morphological control of adrenal medullary cells.     

Gene expression and immunolocalization of heparin-binding epidermal growth factor-like growth factor and human epidermal growth factor receptors in human corpus luteum

BACKGROUND: The objective of this study was to elucidate gene expression and immunolocalization of heparin-binding epidermal growth factor-like growth factor (HB-EGF) and human epidermal growth factor receptor (HER) family in the human ovary during luteal growth and regression. METHODS: Ovaries obtained from pre-menopausal women were used for immunohistochemistry and semiquantitative RT-PCR analysis. RESULTS: Immunoreactive HB-EGF was not detected in follicles or oocyte, while HB-EGF became apparent in granulosa luteal cells in the early luteal phase, and most abundant in the mid-luteal phase, but less abundant in the late luteal phase. Immunostaining for HER1 was very weak in granulosa luteal cells in the early and mid-luteal phases, and was not detected in the late luteal phase. Immunoreactive HER4 was abundant in the early luteal phase and became less abundant in the mid-luteal phase, whereas it was negative in the late luteal phase. Semiquantitative RT-PCR analysis revealed that HB-EGF and HER1 mRNA levels were high in the mid-luteal phase, whereas HER4 mRNA expression was high in the early luteal phase. CONCLUSIONS: HB-EGF may play a vital role in regulating luteal growth in a juxtacrine manner and through activating HER4 signalling.     

Bilateral phasic increases in dorsal root ganglia nerve growth factor synthesis after unilateral sciatic nerve crush

The amount of nerve growth factor (NGF) in the L5, L6, and cervical dorsal root ganglia of rats was examined from 1 to 30 days after a unilateral crush lesion of the sciatic nerve and adjacent branches of the lumbar plexus at the level of the sciatic notch. Unilateral nerve crush produced increases in NGF content of lumbar ganglia at 1, 4, and 7–8 days after injury, with increased NGF mRNA at 4 and 7–8 days. Increases in NGF at 1 and 4 days were most pronounced on the unlesioned side while increases at days 7 and 8 were most pronounced on the lesioned side. NGF content increased in cervical ganglia of nerve-lesioned animals at 3 and 7 days after injury and in lumbar and cervical ganglia of sham-operated animals 3–5 days after surgery, with no comparable changes in NGF mRNA. Elevations of ganglionic NGF coincide temporally with some of the alterations in metabolism and morphology which occur in dorsal root ganglion neurons after sciatic nerve crush. However, the bilateral nature of increases in NGF demonstrates that the factor(s) producing the response is not restricted to ganglia axotomized by the injury. The data suggest that ganglionic NGF may be regulated by systemic factors, produced during stress or trauma, as well as by factors from the denervated target tissue and/or regenerating axons.