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This paper explores the diagnosis of deep invasive endometriosis through retrospective data analysis, including deep infiltration and magnetic resonance imaging. The literature retrospectively collected data from 21 patients with deep invasive endometriosis who were admitted from 2012 to 2018. The patients were confirmed to have pain and nerve growth factor (NGF) receptor expression levels after operation and underwent vaginal color ultrasound and magnetic resonance imaging before surgery. The diagnostic results of color Doppler ultrasound and magnetic resonance imaging were retrospectively analyzed and compared with the surgical results, and the cumulative site and anatomic abnormalities of the diagnosis of deep invasive endometriosis were analyzed to determine the NGF receptor table. Through research it has been found that deep invasive endometriosis mainly involves the uterine fibula ligament, vagina, uterus rectum, rectum, ureter, and so forth. Patient pain is related to the expression level of NGF receptor, and its magnetic resonance mainly manifests as signals and structural obstacles, irregular thickening of the affected area, or nodular formation and deformation of adjacent tissues and organs. Through research and demonstration of deep invasive endometriosis, transvaginal color ultrasound and magnetic resonance imaging can not only accurately locate the expression levels of pain and NGF receptors, but also show the extent of the lesions, thereby studying pain and NGF receptor expression, which is an important method for preoperative examination and postoperative follow-up., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Accumulating evidence suggests functional interaction between brain-derived neurotrophic factor (BDNF) and metabotropic glutamate receptor (mGluR) signaling pathways in the central nervous system (CNS). To date, eight subtypes of mGluRs, mGluR1-8, have been identified, and a previous study suggested that BDNF leads to down-regulation of GluR2 mRNA in rat cerebral cortical cultures. However, precise transcriptomic effects of BDNF on other mGluRs and their cellular significance on the BDNF signaling pathway remain largely unknown. In this study, we assessed the transcriptomic effects of BDNF on mGluR1-8 in primary cultures of rat cerebral cortical neurons, and transcriptomic impacts of mGluR(s) whose expression is regulated by BDNF, on BDNF target genes. Real-time quantitative PCR (RT-qPCR) revealed that stimulation of the cultures with 100ng/mL BDNF led to marked reductions not only in the gene expression levels of mGluR2, but also in those of mGluR3, both of which belong to group II mGluRs (mGluR II). There were, on the other hand, no changes in the amounts of mGluR I (mGluR1 and 5) and III (mGluR4, 6, 7, and 8) mRNA. Further, 10ng/mL of BDNF, which mainly activates the high-affinity BDNF receptor, TrkB, but not the low-affinity receptor, p75 NTR , was able to induce down-regulation of mGluR II mRNA. The BDNF-induced suppression of mGluR II was not significantly attenuated in the presence of tetrodotoxin (TTX), a blocker for voltage-gated sodium channels. In addition, on stimulation with BDNF (100ng/mL), no significant down-regulation of mGluR II mRNA was seen in cultured astrocytes, which only express the truncated form of TrkB. Finally, we assessed the transcriptomic effect of mGluR II on the expressions of BDNF target genes, BDNF and activity-regulated cytoskeleton-associated protein (Arc). LY404039, an mGluR II agonist, enhanced the BDNF-induced up-regulation of BDNF, but not Arc. On the other hand, LY341495, an mGluR II antagonist, down-regulated BDNF mRNA levels. Collectively, these observations demonstrated the detailed functional interaction between BDNF and mGluR II: Activation of mGluR II positively regulates self-induced BDNF expression, and, in turn, BDNF negatively regulates the gene expression of mGluR II in a neuronal activity-independent manner, in cortical neurons, but not in astrocytes., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Neurotrophins stimulate the regeneration of neural tissue after lesions. It is also known that the sources of neurogenesis and cerebral function recovery are predominantly located in subcortical brain structures. The effects of ischemia on the expression of genes that encode neurotrophins (Bdnf, Ngf, Nt-3) and their receptors (TrkB, TrkA, TrkC, p75) in brain structures outside the lesion site were studied 3, 24, and 72 h after irreversible unilateral occlusion of the middle cerebral artery in rats. Changes in the mRNA expression of these genes were assessed by relative quantification using real-time RT-PCR. Sham surgery was found to stimulate the expression of genes that encode neurotrophins (Bdnf, Ngf) and their receptor (p75). It has been shown that ischemia influenced the expression of neurotrophins (Bdnf, Ngf, Nt-3) and their receptors (TrkB, TrkA, TrkC, p75) in brain structures outside the lesion focus, including the contralateral hemisphere. The downregulation of Bdnf and TrkB transcripts and Ngf and TrkA upregulation in the contralateral cortex on the first day of ischemia obviously reflected stress response. On day 3, Nt-3 transcription increased in all investigated structures outside the lesion focus. In the contralateral hemisphere, relative levels of TrkA and TrkC mRNA expression increased, while p75 expression decreased. Presumably, the observed changes in gene transcription serve to facilitate neuroplasticity and neural tissue regeneration.

Background: The roles of the neurotrophins NGF (Neurotrophic growth factor) and BDNF (brain-derived neurotrophic factor) in neuronal growth and development are already known. Meanwhile, the neurotrophin receptors TrkA (tropomyosin related kinase A), TrkB, and p75 are important for determining the fate of cells. In endometriosis, this complex system has not been fully elucidated yet. The aim of this study was to evaluate the expression and location of these neurotrophins and their receptors in peritoneal (PE) and deep infiltrating endometriotic (DIE) tissues and to measure and compare the density of nerve fibers in the disease subtypes., Methods: PE lesions (n = 20) and DIE lesions (n = 22) were immunostained and analyzed on serial slides with anti-BDNF, -NGF, -TrkA, -TrkB, -p75,-protein gene product 9.5 (PGP9.5, intact nerve fibers) and -tyrosine hydroxylase (TH, sympathetic nerve fibers) antibodies., Result: There was an equally high percentage (greater than 75 %) of BDNF-positive immunostaining cells in both PE and DIE. TrkB (major BDNF receptor) and p75 showed a higher percentage of immunostaining cells in DIE compared to in PE in stroma only (p < 0.014, p < 0.027, respectively). Both gland and stroma of DIE lesions had a lower percentage of NGF-positive immunostaining cells compared to those in PE lesions (p < 0.01 and p < 0.01, respectively), but there was no significant reduction in immunostaining of TrkA in DIE lesions. There was no difference in the mean density of nerve fibers stained with PGP9.5 between PE (26.27 ± 17.32) and DIE (28.19 ± 33.15, p = 0.8). When we performed sub-group analysis, the density of nerves was significantly higher in the bowel DIE (mean 57.33 ± 43.9) than in PE (mean 26.27 ± 17.32, p < 0.01) and non-bowel DIE (mean 14.6. ± 8.6 p < 0.002)., Conclusions: While the neurotrophin BDNF is equally present in PE and DIE, its receptors TrkB and p75 are more highly expressed in DIE and may have a potential role in the pathophysiology of DIE, especially in promotion of cell growth. BDNF has a stronger binding affinity than NGF to the p75 receptor, likely inducing sympathetic nerve axonal pruning in DIE, resulting in the lower nerve fiber density seen.

The p75 neurotrophin receptor is important in multiple physiological actions including neuronal survival and neurite outgrowth during development, and after central nervous system injury. We have discovered a novel piperazine-derived compound, EVT901, which interferes with p75 neurotrophin receptor oligomerization through direct interaction with the first cysteine-rich domain of the extracellular region. Using ligand binding assays with cysteine-rich domains-fused p75 neurotrophin receptor, we confirmed that EVT901 interferes with oligomerization of full-length p75 neurotrophin receptor in a dose-dependent manner. Here we report that EVT901 reduces binding of pro-nerve growth factor to p75 neurotrophin receptor, blocks pro-nerve growth factor induced apoptosis in cells expressing p75 neurotrophin receptor, and enhances neurite outgrowth in vitro Furthermore, we demonstrate that EVT901 abrogates p75 neurotrophin receptor signalling by other ligands, such as prion peptide and amyloid-β. To test the efficacy of EVT901 in vivo, we evaluated the outcome in two models of traumatic brain injury. We generated controlled cortical impacts in adult rats. Using unbiased stereological analysis, we found that EVT901 delivered intravenously daily for 1 week after injury, reduced lesion size, protected cortical neurons and oligodendrocytes, and had a positive effect on neurological function. After lateral fluid percussion injury in adult rats, oral treatment with EVT901 reduced neuronal death in the hippocampus and thalamus, reduced long-term cognitive deficits, and reduced the occurrence of post-traumatic seizure activity. Together, these studies provide a new reagent for altering p75 neurotrophin receptor actions after injury and suggest that EVT901 may be useful in treatment of central nervous system trauma and other neurological disorders where p75 neurotrophin receptor signalling is affected., (© The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain.)

We recently reported that increased NGF and p75(NTR) as well as decreased trkA(NGFR) characterized the Reelin-deprived (E-Reeler) retina, prospecting a potential contribution of NGF during E-Reeler retinogenesis. Herein, retinal ganglion cells (RGCs), glial cells and rod bipolar cells (RBCs) were isolated from E-Reeler retinas, and NGF, trkA(NGFR)/p75(NTR) expression and apoptosis were investigated. E-Reeler (n = 28) and E-control (n = 34) retinas were digested, and RGCs, glial cells and RBCs were isolated by the magnetic bead separation. Expression of NGF, trkA(NGFR), p75(NTR), Annexin V/PI and Bcl2/Bax was quantified by flow cytometry and validated by real-time PCR or WB. In E-Reeler retinas, NGF was significantly increased in RGCs and glial cells, p75(NTR) was increased in both RBCs and RGCs, and trkA(NGFR) was unchanged. In E-control retinas, NGF and p75(NTR) were expressed mainly in RBCs and RGCs and faintly in glial cells, while trkA(NGFR) was weakly expressed by RBCs and RGCs. In RBCs and RGCs, Annexin V expression was unchanged, while Bcl2 increased and Bax decreased selectively in E-Reeler RGCs. The data indicate that E-Reeler RBCs and RGCs overexpress NGF and p75(NTR) as a protective endogenous response to Reelin deprivation. The observation is strongly supported by the absence of apoptosis in both cell types.

The nerve growth factor (NGF) not only has an essential effect on the nervous system, but also plays an important role in a variety of non-neuronal systems, such as the reproductive system. The aim of this study was to investigate the seasonal changes in expression of NGF and its receptors (TrkA and p75) in testes of the wild ground squirrel during the breeding and nonbreeding seasons. Immunolocalization for NGF was detected mainly in Leydig cells and Sertoli cells in testes of the breeding and nonbreeding seasons. The immunoreactivity of TrkA was highest in the elongated spermatids, whereas p75 in spermatogonia and spermatocytes in testes of the breeding season. In the nonbreeding season testes, TrkA showed positive immunostainings in Leydig cells, spermatogonia and primary spermatocytes, while p75 showed positive signals in spermatogonia and primary spermatocytes. Consistent with the immunohistochemical results, the mean mRNA and protein level of NGF and TrkA were higher in the testes of the breeding season, and then decreased to a relatively low level in the nonbreeding season. In addition, the concentration of plasma gonadotropins and testosterone were assayed by radioimmunoassay (RIA), and the results showed a significant seasonal change between the breeding and nonbreeding seasons. To conclude, these results of this study provide the first evidence on the potential involvement of NGF and its receptor, TrkA and p75 in the seasonal spermatogenesis and testicular function change of the wild ground squirrel.

Neurotrophins and their respective tropomyosin related kinase (Trk) receptors (TrkA, TrkB, and TrkC) and the p75 neurotrophin receptor (p75(NTR)) play a fundamental role in the development and maintenance of the nervous system making them important targets for treatment of neurodegenerative diseases. Whereas Trk receptors are directly activated by specific neurotrophins, the p75(NTR) is a multifunctional receptor that exerts its effects via heterodimeric interactions with TrkA, TrkB, TrkC, sortilin or the Nogo receptor to regulate a wide array of cellular functions. By partnering with different receptors the p75(NTR) regulates binding of mature versus pro-neurotrophins and activation of different signaling pathways with outcomes ranging from growth and survival to cell death. While the developmental downregulation of the p75(NTR) has raised questions regarding its role in the mature nervous system, recent data have revealed widespread expression of low levels, a role in synaptic plasticity and adult neurogenesis and upregulation in response to injury or disease. Studies are needed to better understand these processes, particularly in the damaged nervous system, but will be complicated by expression of p75(NTR) on immune cells including macrophages and microglia that are intimately involved in disease and repair processes. Recent approaches that regulate p75(NTR) function with small non-peptide ligands have demonstrated potent neuroprotection in models of injury and neurodegenerative diseases that highlight the importance of the p75(NTR) as a therapeutic target. Future studies hold the promise of revealing a wealth of information on the multifaceted actions of the p75(NTR) that will inform the design of new neurotrophin-based therapies.

Lung squamous cell carcinoma (SCC) is a deadly disease for which current treatments are inadequate. We demonstrate that biallelic inactivation of Lkb1 and Pten in the mouse lung leads to SCC that recapitulates the histology, gene expression, and microenvironment found in human disease. Lkb1;Pten null (LP) tumors expressed the squamous markers KRT5, p63 and SOX2, and transcriptionally resembled the basal subtype of human SCC. In contrast to mouse adenocarcinomas, the LP tumors contained immune populations enriched for tumor-associated neutrophils. SCA1(+)NGFR(+) fractions were enriched for tumor-propagating cells (TPCs) that could serially transplant the disease in orthotopic assays. TPCs in the LP model and NGFR(+) cells in human SCCs highly expressed Pd-ligand-1 (PD-L1), suggesting a mechanism of immune escape for TPCs., (Copyright © 2014 Elsevier Inc. All rights reserved.)

We examine developmental changes in the responsiveness of rat vestibular ganglion neurons (VGNs) to two neurotrophic factors (NTFs), brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) and investigate the protective effects of these NTFs against ototoxic drugs during postnatal development in dissociated cultures. VGNs were obtained from rats on postnatal days (P) 1, 3, 7 and 14. BDNF facilitated neuronal survival as well as neurite sprouting of VGNs obtained from younger rats (P1 and P3), whereas these effects were not observed in older rats (P7 and P14). BDNF was also effective in facilitating neurite extension in VGNs at each of the postnatal ages. NT-3 also facilitated neuronal survival and neurite extension of VGNs from younger rats but these effects were significantly smaller than those of BDNF (p < 0.05). The protective effects of BDNF and NT-3 against ototoxic drugs, gentamicin and cisplatin, were also age-dependent: they were effective for neuronal survival, neurite sprouting and neurite extension in VGNs from younger rats, whereas these effects tended to disappear in VGNs from older rats. Analysis of the changes in the expression of the receptors of NTFs revealed that expression of TrkB and TrkC proteins and their mRNA did not change during the developmental period, whereas expression of p75(NTR) protein was down-regulated together with that of p75(NTR) mRNA during the developmental period. Developmental changes in the responsiveness to exogenous NTFs in VGNs, which is not caused by the changes of their receptors but probably caused by changes in the intracellular signaling pathways, should be taken into consideration in the prevention of neuronal degeneration caused by ototoxic drugs.

In Alzheimer's disease (AD), extensive neuronal loss and a deficiency of the neurotransmitter acetylcholine (ACh) are the major characteristics during pathogenesis in the brain. In the present study, we aimed to investigate whether representative ginsenosides from ginseng can regulate choline acetyltransferase (ChAT) and vesicular acetylcholine transporter (VAChT), which are required for cholinergic neurotransmission. Our results revealed that Re and Rd induced effectively the expression of ChAT/VAChT genes in Neuro-2a cells as well as ACh elevation. Microtubule-associated protein-2 (MAP-2), nerve growth factor receptor (p75), p21, and TrkA genes and proteins were also significantly expressed. Moreover, both activated extracelullar signal-regulated protein kinase (ERK) and Akt were inhibited by K252a, a selective Trk receptor inhibitor. These findings strongly indicate that Re and Rd play an important role in neuronal differentiation and the nerve growth factor (NGF)-TrkA signaling pathway. High performance liquid chromatography analysis showed that Re and Rd administered orally were transported successfully into brain tissue and increased the level of ChAT and VAChT mRNA. The present study demonstrates that Re and Rd are selective candidates for upregulation of the expression of cholinergic markers, which may counter the symptoms and progress of AD.

Sortilin, a Golgi sorting protein and a member of the VPS10P family, is the co-receptor for proneurotrophins, regulates protein trafficking, targets proteins to lysosomes, and regulates low density lipoprotein metabolism. The aim of this study was to investigate the expression and regulation of sortilin in Alzheimer's disease (AD). A significantly increased level of sortilin was found in human AD brain and in the brains of 6-month-old swedish-amyloid precursor protein/PS1dE9 transgenic mice. Aβ₄₂ enhanced the protein and mRNA expression levels of sortilin in a dose- and time-dependent manner in SH-SY5Y cells, but had no effect on sorLA. In addition, proBDNF also significantly increased the protein and mRNA expression of sortilin in these cells. The recombinant extracellular domain of p75(NTR) (P75ECD-FC), or the antibody against the extracellular domain of p75(NTR), blocked the up-regulation of sortilin induced by Amyloid-β protein (Aβ), suggesting that Aβ₄₂ increased the expression level of sortilin and mRNA in SH-SY5Y via the p75(NTR) receptor. Inhibition of ROCK, but not Jun N-terminal kinase, suppressed constitutive and Aβ₄₂-induced expression of sortilin. In conclusion, this study shows that sortilin expression is increased in the AD brain in human and mice and that Aβ₄₂ oligomer increases sortilin gene and protein expression through p75(NTR) and RhoA signaling pathways, suggesting a potential physiological interaction of Aβ₄₂ and sortilin in Alzheimer's disease., (© 2013 International Society for Neurochemistry.)

To compare genes expression of BDNF and its receptors, TrkB and p75 between pregnant and non-pregnant uterine and oviductal tissues of ewes, semi-quantitative RT-PCR was performed. BDNF, TrkB and p75 genes are normally expressed in the ovine uterus and oviduct. The relative amounts of BDNF mRNA were increased in the uterine segments of the pregnant samples with compared to non-pregnant samples. This increasing was only significant (P<0.05) in the inter-caruncle segment and in the cervix, which was not detectable in non-pregnant samples. In contrast, the relative amounts of BDNF mRNA were decreased in the oviductal segments of the pregnant samples and were undetectable in the isthmus. Variations of the relative amounts of TrkB and p75 mRNAs between the pregnant and non-pregnant samples were not significant (P>0.05) although TrkB mRNA in the caruncle and cervix and p75 mRNA in the cervix of pregnant samples were too less to be detected by RT-PCR method. It is probably that these changes of BDNF/receptors genes expression are necessary for normal pregnancy, and abnormal variations in the expression of these genes may be involved in the pathophysiological conditions., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Background: Induction of p75 neurotrophin receptor (p75NTR) could be one of the first steps that initiate apoptotic cascade after injury, or it may indicate regeneration responses undertaken by the injured system, possibly in collaboration with resident tropomyosin-receptor-kinase (Trk)., Objective: To measure quantitative changes in messenger RNA (mRNA) expression levels of p75NTR, Trk A, and caspase-9 in rat's injured spinal cord (SCI). The reciprocal interaction between Trk and p75NTR signaling pathways can dictate cellular responses to neurotrophins. p75NTR can regulate Trk-dependent responses, but the role of Trk in regulating p75NTR-dependent signaling is not well documented., Design: Using real-time polymerase chain reaction, this study analyzed changes in the mRNA abundance of the mentioned genes at 6, 24, and 72 hours and 7 and 10 days after SCI in adult male rats. SCI was induced at T9 level by transsection., Results: Results show a complicated temporal and spatial pattern of alteration with different degrees and direction (up- or down-regulation) in p75NTR, Trk A, and caspase-9 mRNA expression levels after SCI. The greatest variation was seen in center regions following SCI. This study shows that alteration in p75NTR, Trk A, and caspase-9 expression starts as early as 6 hours after SCI. Alterations in p75NTR, Trk A, and caspase-9 expression within the spinal cord may play a key role in the apoptotic cell death., Conclusion: Results suggest that the role of p75NTR is to eliminate damaged cells by activating the apoptotic machinery, especially at the center of damage and during first week after injury.

Background: Our understanding of the pathogenesis of frozen shoulder and why it is so painful is undetermined. This study investigated the expression of neuronal proteins in the capsular tissue of frozen shoulder., Methods: Shoulder capsular samples were collected from 8 patients with idiopathic adhesive capsulitis and 10 patients with a rotator cuff tear but no stiffness (controls). Samples were analyzed by immunohistochemistry using antibodies against protein gene product 9.5 (PGP9.5), a general nerve marker; growth associated protein 43 (GAP43), a nerve growth marker; nerve growth factor receptor p75; and CD34, an endothelial cell marker., Results: Samples from frozen shoulders showed subsynovial hypercellularity and fibroblastic proliferation, with increased expression of nerve growth factor receptor p75 and CD34 compared with controls. Nerves positive for PGP9.5 and GAP43 were more abundant in samples of frozen shoulder (2.8 ± 0.2 and 2.4 ± 0.4 per field; P < .01) compared with controls (1.6 ± 0.3 and 1.3 ± 0.3 per field; P < .05). Expression of neuronal proteins followed that of CD34., Conclusion: Increased expression of nerve growth factor receptor and new nerve fibers were found in the shoulder capsular tissue of patients with frozen shoulder compared with those without a frozen shoulder. These data suggest that neoinnervation and neoangiogenesis in the shoulder capsule are important events in the pathogenesis of frozen shoulder and may help explain the often-severe pain of patients with frozen shoulder., (Copyright © 2012 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.)

P75 nerve growth factor receptor (p75 NGF-R) is a low-affinity receptor expressed on the surface of neural crest-derived cells and in a variety of neural tumors. Strong p75 NGF-R expression has been found in spindle cell melanoma (SCM). We studied spindle cell neoplasms of sun-damaged skin to determine whether this marker can reliably distinguish between SCM and other spindle cell malignancies. We evaluated the staining of p75 NGF-R, S100, and HMB-45 in 11 cases of SCM, 16 cases of spindle cell squamous cell carcinoma (SCSCC), 19 cases of spindle cell atypical fibroxanthoma, 6 cases of cutaneous leiomyosarcoma, and 20 scars. Staining with p75 NGF-R was positive in all 11 of 11 (100%) cases of SCM, whereas S100 stained 10 of 11 (91%) cases, and HMB-45 was negative in all SCMs. In addition, there was superior intensity of the staining for p75 NGF-R in comparison to S100. P75-NGF-R showed focal positivity in 3 of 16 (19%) cases of SCSCC. None of the rest of the cases of SCSCC, and none of the cases of spindle cell atypical fibroxanthoma, cutaneous leiomyosarcoma, and scars expressed p75 NGF-R, S100, or HMB-45. P75 NGF-R is a useful marker to distinguish SCM from other spindle cell neoplasms of sun-damaged skin. This marker exhibits greater sensitivity than S100 in identifying SCM and may be a useful diagnostic and ancillary stain especially in the setting of an S100 negative spindle cell neoplasm.

Visceral hyperalgesia is a multifactorial gastrointestinal disorder which featured with alterations of abdominal motility and/or gut sensitivity, and is believed to be triggered by environmental stressor or psychological factors. However, its etiology remains incompletely understood. In this study, we aimed to investigate whether nerve growth factor (NGF)-mediated neuronal plasticity is involved in neonatal maternal separation (NMS)-induced visceral hypersensitivity in adult rats, and whether NGF antagonist can attenuate or block such development. In our experiments, animals subjected to NMS were developed with visceral hyperalgesia at age of 8 weeks. The threshold for visceral pain among these NMS rats was remarkably lowered than that of the normal handling (NH) rats; however, the expression levels of NGF, c-fos, calcitonin gene-related peptide (CGRP), Substance P, and tyrosine kinases A (TrkA) were notably elevated in lumbosacral spinal cord and/or dorsal root ganglion (DRG) when comparing to those of the NH rats. Further, as intra-peritoneal administration of NGF (10 μl at 1 μg/kg/day) was given to NH rats during neonatal period, effects that comparable to NMS induction were observed in the adulthood. In contrast, when NMS rats were treated with NGF antagonist K252a (10 μl/day from postnatal days 2-14), which acts against tyrosine kinases, the neonatal stress-induced down-shifted visceral pain threshold was restored and neuronal activation, specifically NGF and neuropeptide production, was attenuated. In conclusion, our data strongly suggest that NGF triggers neuronal plasticity and plays a crucial role in NMS-induced visceral hypersensitivity in which NGF antagonism provides positive inhibition via blocking the tyrosine phosphorylation of TrkA., (© 2011 European Federation of International Association for the Study of Pain Chapters.)

The geniculate ganglion, which provides innervation to taste buds in the anterior tongue and palate, is unique among sensory ganglia in that its neurons depend on both neurotrophin-4 (NT4) and brain-derived neurotrophic factor (BDNF) for survival. Whereas BDNF is additionally implicated in taste axon guidance at targeting stages, much less is known about the guidance role of NT4 during targeting, or about either neurotrophin during initial pathfinding. NT4 and BDNF have distinct expression patterns in vivo, raising the possibility of distinct roles. We characterized the influence of NT4 and BDNF on geniculate neurites in collagen I gels at early embryonic through postnatal stages. During early pathfinding to the tongue (embryonic days 12-13; E12-13), NT4 and BDNF promote significantly longer outgrowth than during intralingual targeting (E15-18). NT4 is more potent than BDNF at stimulating neurite outgrowth and both factors exhibit concentration optima, i.e. intermediate concentrations (0.25 ng/ml NT4 or 25 ng/ml BDNF) promote maximal neurite extension and high concentrations (10 ng/ml NT4 or 200 ng/ml BDNF) suppress it. Only partial suppression was seen at E12 (when axons first emerge from the ganglion in vivo) and postnatally, but nearly complete suppression occurred from E13 to E18. We show that cell death is not responsible for suppression. Although blocking the p75 receptor reduces outgrowth at the optimum concentrations of NT4 and BDNF, it did not reduce suppression of outgrowth. We also report that NT4, like BDNF, can act as a chemoattractant for geniculate neurites, and that the tropic influence is strongest during intralingual targeting (E15-18). NT4 does not appear to act as an attractant in vivo, but it may prevent premature invasion of the epithelium by suppressing axon growth., (Copyright © 2012 S. Karger AG, Basel.)

The cellular localization of nerve growth factor (NGF) and its receptors (TrkA, p75) was investigated during the estrous cycle in gilts. Also, the levels of expression of these factors in walls of tertiary follicles and corpora lutea (CLs) were determined using Western blot. The ovaries from days 3, 7, 16 and 20 of the cycle revealed the presence of NGF and its receptors in oocytes of secondary and tertiary follicles, follicular cells of primary and secondary follicles, thecal and granulosa cells of tertiary follicles and steroidogenic cells of CLs. In wall cells of primary follicles, NGF, TrkA and p75 staining was strongest on day 16, while in secondary follicles, only p75 was more intensely stained on day 16 and 20. In walls of small (to 3 mm in diameter) and medium (4-6 mm in diameter) follicles, NGF staining was lower on day 16, and the p75 reaction was strongest on day 20. On day 20, NGF staining in large follicles (7-10 mm in diameter) was higher than in smaller follicles. The levels of NGF and p75 in small and medium follicles were highest on day 20. The contents of NGF and TrkA in large follicles on day 20 were higher than in smaller follicles. NGF and TrkA contents in CLs were highest on day 7. Our study demonstrates that NGF, TrkA and p75 are expressed in the ovary during the estrous cycle in gilts. These results suggest that NGF and its receptors may be important for ovarian function in cycling gilts.

New approaches to the clinical treatment of traumatic nerve injuries may one day utilize stem cells to enhance nerve regeneration. Adipose-derived stem cells (ASC) are found in abundant quantities and can be harvested by minimally invasive procedures that should facilitate their use in such regenerative applications. We have analyzed the properties of human ASC isolated from the deep and superficial layers of abdominal fat tissue obtained during abdominoplasty procedures. Cells from the superficial layer proliferate significantly faster than those from the deep layer. In both the deep and superficial layers, ASC express the pluripotent stem cell markers oct4 and nanog and also the stro-1 cell surface antigen. Superficial layer ASC induce the significantly enhanced outgrowth of neurite-like processes from neuronal cell lines when compared with that of deep layer cells. However, analysis by reverse transcription with the polymerase chain reaction and by enzyme-linked immunosorbent assay has revealed that ASC isolated from both layers express similar levels of the following neurotrophic factors: nerve growth factor, brain-derived neurotrophic factor and glial-derived neurotrophic factor. Thus, human ASC show promising potential for the treatment of traumatic nerve injuries. In particular, superficial layer ASC warrant further analysis of their neurotrophic molecules.

Desmoplastic melanoma is a rare variant of malignant melanoma composed of spindle cells in a collagenous matrix. The antibody against NGFR (low affinity nerve growth factor receptor, also known as p75) stains cells of desmoplastic melanoma with high sensitivity; however, the specificity of this marker is not well established. Although there are established histologic criteria for recognition of desmoplastic melanoma, the evaluation of residual disease in cutaneous reexcision scars can be challenging. If residual spindle cells in scar are sufficiently atypical and NGFR positive, their presence could be interpreted as residual desmoplastic melanoma. In this study, we reevaluated the use of antibody against NGFR to detect residual disease in reexcision specimens of melanocytic neoplasms as the previously published works are contradictory. Our data indicate that anti-NGFR antibody stains many cells in the scar, some of which seem to be myofibroblasts, nerve twigs, and Schwann cells. Our findings further suggest that NGFR is not a suitable marker to evaluate reexcision scars for desmoplastic melanoma, especially as a sole marker, as its specificity is low.

To clarify the effect of indoor air pollutants on nerve growth factor (NGF) production in lung, male C3H/HeN mice were exposed to filtered air (control) or toluene at levels of 0.9 ppm, 9 ppm, or 90 ppm for 30 min via nose-only inhalation on days 0, 1, 2, 7, 14, 21, 28, 35, 42, 49 and 56. As an allergic mouse model, some mice (n=24) were immunized with ovalbumin. Lungs from each mouse were collected to determine NGF and related receptor expressions using real-time reverse transcription polymerase chain reaction (RT-PCR) analysis. NGF and TrkA mRNAs were increased in the lungs of the immunized mice following exposure to 9 ppm toluene (n=6) (P<0.05 ppm vs. 0 ppm). Remarkably increased NGF-positive bronchiolus and alveolar epithelium cells were observed in 9 ppm toluene-exposed, immunized mice. To determine NGF mediating signaling, we also examined mRNA expression of neurotrophin receptor p75 (p75(NTR)) and oxidative stress marker, heme oxygenase (HO)-1 in the lung. There is no difference in the expressions of p75(NTR) and HO-1 between toluene-exposed and control mice. The expression of CCL2 and CCL3 mRNAs was significantly elevated in 9 ppm toluene-exposed, immunized mice. These findings suggest that the exposure with volatile organic compounds enhanced NGF expression and airway inflammation stronger in allergic individuals than in healthy individuals.

Aims: Multipotent mesenchymal stromal cells (MSC) have been reported to prevent the development of liver fibrosis and have emerged as a promising strategy for cell-based therapy. However, the underlying therapeutic mechanism remains unclear. Hepatic stellate cells (SC) activation is a pivotal event in the development of liver fibrosis., Main Methods: We hypothesized that MSC play an important role in regulating SC proliferation and apoptosis through paracrine mechanisms. To investigate the paracrine interactions between MSC and SC, a co-culture experimental model was developed using human MSC (hMSC) and human SC (hSC)., Key Findings: We demonstrate that hMSC and hSC both express nerve growth factor (NGF) receptor p75. Results acquired from transwell co-culture experiments using hSC and hMSC showed that hMSC secrete NGF, which enhances hSC apoptosis. Transcription factor nuclear factor kappa B (NF-KappaB) and B cell leukemia-xl (Bcl-xl) take part in the process., Significance: These findings demonstrated that hMSC indirectly modulate activated hSC in vitro via NGF-mediated signaling cascades and provide a potential mechanism of how transplanted MSC are effective in treating liver fibrosis.

Backgrounds/aims: Pancreatic carcinoma is one of the most aggressive human malignancies. The aggressive and highly metastatic behaviour of pancreatic carcinoma may partly be attributable to the autocrine and/or paracrine interactions involving altered expression of neurotrophin growth factors and their corresponding receptors. The aim of the present study is to investigate the expression pattern and function of the p75(NGFR) protein in pancreatic cancer cell lines and tumours to explain the phenomenon of perineural invasion in pancreatic cancer., Methods: The expression of p75(NGFR) in 137 pancreatic adenocarcinoma samples and the corresponding adjacent pancreatic samples was examined immunohistochemically using the EnVision Plus System. Then we examined the in vitro chemotaxis behaviour of cancer cells transfected with p75(NGFR) plasmid to nerve growth factor (NGF)., Results: Immunostaining for p75(NGFR) was weak or absent in both normal pancreata and pancreatic carcinoma tissues; however, the immunostaining was relatively weaker in the pancreatic carcinoma tissues than in the normal pancreata. It is interesting to note that p75(NGFR) expression in the cancer tissues was positively correlated with the degree of perineural invasion (chi(2)=32.94, P<0.01). The chemotaxis ability of the p75(NGFR)-transfected pancreatic cancer cells to NGF was significantly stronger than that of the non-transfected or vacant vector transfected cells (P<0.01)., Conclusions: Our findings indicate that p75(NGFR) expression may be involved in the perineural invasion of pancreatic cancer cells, and the mechanism might be through mediating the chemoattraction of cancer cells for neural tissues.

Olfactory ensheathing cells (OECs) are specialized glial cells that guide olfactory receptor axons from the nasal mucosa into the brain where they make synaptic contacts in the olfactory bulb. While a number of studies have demonstrated that in vivo transplantation of OECs into injured spinal cord results in improved functional outcome, precise cellular mechanisms underlying this improvement are not fully understood. Current thinking is that OECs can encourage axonal regeneration, provide trophic support for injured neurons and for angiogenesis, and remyelinate axons. However, Schwann cell (SC) transplantation also results in significant functional improvement in animal models of spinal cord injury. In culture SCs and OECs share a number of phenotypic properties such as expression of the low affinity NGF receptor (p75). An important area of research has been to distinguish potential differences in the in vivo behavior of OECs and SCs to determine if one cell type may offer greater advantage as a cellular therapeutic candidate. In this review we focus on several unique features of OECs when they are transplanted into the spinal cord.

p75 neurotrophin receptor (p75NTR) is a member of the tumor necrosis factor superfamily, and plays a significant role in nervous system development. p75NTR has a dual (proliferative/apoptotic) role in neurogenesis and binds pro-neurotrophins with high affinity. Recent work suggests p75NTR is overexpressed in the developing cerebellum and in nodular/desmoplastic medulloblastomas. We analyzed p75NTR expression in various parts of the fetal and adult human central nervous system, and in 75 patients with medulloblastomas. The expression of p75NTR in the fetal brain was seen solely within the external granular layer with weaker expression in the Purkinje layer, which most likely represents Purkinje cell staining. The staining was present in gestational weeks 20-40, while no staining was identified elsewhere in the fetal brain or within the adult cerebellum. p75NTR positive cells were also positive with the proliferation marker ki-67, but were negative for ret, reelin, CD133, CD34, and cleaved caspase 3. Nine of 75 medulloblastomas (12%) were also showed positive immunostaining for p75NTR. The staining was seen in four classic, two desmoplastic, and three anaplastic medulloblastomas. The persistence of p75NTR in a small group of medulloblastomas raises the possibility that in such tumors, the receptor could be a potential therapeutic target.

Dysembryoplastic neuroepithelial tumors (DNTs) are benign glial-neuronal neoplasms with characteristic cliniopathologic features. Three histologic forms of DNTs have been described (simple, complex, and non-specific). The developmental origin of the tumors remains controversial. To determine the developmental origin and nature of the histologic forms of DNTs, immunohistochemical studies of nestin, TrkA, TrkB, p75, and NeuN were conducted in 40 cases of DNTs, including 11, 9, and 20 simple, complex, and non-specific forms, respectively. Nestin positivity of oligodendroglia-like cells (OLCs) was present in 50 and 27.3% of simple and complex forms, respectively. In the non-specific form of DNT, 94.7% of the cases were positive for nestin. Most DNTs exhibited diffuse, strong staining for TrkA and TrkB, irrespective of the histologic subtypes. Both p75 and NeuN positivity were found in about one-half of the simple, complex, and non-specific forms, respectively. Our study suggests that OLCs are a heterogeneous population of cells, and higher expression of nestin in the non-specific form of DNTs compared to the simple or complex forms suggests that the non-specific form has an earlier developmental origin than the simple or complex forms.

Objectives: The incidence of chemotherapy induced peripheral neuropathy (CIPN) is 15-25% with platinum and taxanes. CIPN can be permanent and often requires dose reduction or change in chemotherapy. Acetyl-l-carnitine (ALCAR), an ester of l-carnitine, is used to treat CIPN in humans and in animal models. The goals of this study are: 1) examine the effects of ALCAR on ovarian cancer cells, 2) determine if ALCAR affects the cytotoxicity of standard chemotherapy on ovarian cancer cells., Methods: OVCAR-3 and SKOV-3 ovarian cancer lines were incubated in ALCAR containing media. Viability, proliferation, and expression of the nerve growth factor receptors (NGFR) Trk-A and p-75 were determined by flow cytometry. Cytotoxicity assays examining ALCAR's effect on paclitaxel and carboplatin were done by flow cytometry and infrared plate-reader., Results: Flow cytometry showed no change in percent live (p = 0.87) or proliferation (p = 0.95) of OVCAR-3 cells when comparing controls with up to 100 microM ALCAR. However, there was a slight but significant decrease in the proliferation of SKOV-3 cells incubated at higher ALCAR concentrations (p = < 0.01). Flow cytometry showed no difference in the viability of OVCAR-3 cells when comparing ALCAR: +/- paclitaxel (p = 1), +/- carboplatin (p = 0.8), or both (p = 0.4). Proliferation assays indicated that paclitaxel's cytotoxicity on OVCAR-3 and SKOV-3 cells was unchanged at higher ALCAR concentrations (p = < 0.01-0.4). ALCAR did not affect the expression of NGFR on OVCAR-3 or SKOV-3 cells., Conclusion: ALCAR does not affect the cytotoxicity of paclitaxel or carboplatin. There was no increase in proliferation, or NGFR of OVCAR-3 or SKOV-3 cells exposed to ALCAR.

Background: The physiological functions of neurotrophins occur through binding to two receptors: pan75 neurotrophin receptor (p75(NTR)) and a family of tropomyosin receptor kinases (Trks A, B, and C). We recently reported that expression of neurotrophins and TrkB were reduced in brains of suicide subjects. This study examines whether expression and activation of Trk receptors and expression of p75(NTR) are altered in brain of these subjects., Methods: Expression levels of TrkA, B, C, and of p75(NTR) were measured by quantitative reverse transcription polymerase chain reaction and Western blot in prefrontal cortex (PFC) and hippocampus of suicide and normal control subjects. The activation of Trks was determined by immunoprecipitation followed by Western blotting using phosphotyrosine antibody., Results: In hippocampus, lower mRNA levels of TrkA and TrkC were observed in suicide subjects. In the PFC, the mRNA level of TrkA was decreased, without any change in TrkC. However, the mRNA level of p75(NTR) was increased in both PFC and hippocampus. Immunolabeling studies showed similar results as observed for the mRNAs. In addition, phosphorylation of all Trks was decreased in hippocampus, but in PFC, decreased phosphorylation was noted only for TrkA and B. Increased expression ratios of p75(NTR) to Trks were also observed in PFC and hippocampus of suicide subjects., Conclusions: Our results suggest not only reduced functioning of Trks in brains of suicide subjects but also that increased ratios of p75(NTR) to Trks indicate possible activation of pathways that are apoptotic in nature. These findings may be crucial in the pathophysiology of suicide.

Estradiol is a key hormone in the regulation of reproductive processes acting both on peripheral organs and sympathetic neurons associated to reproductive function. However, many of its regulatory effects on the development and function on the sympathetic neurons have not been completely clarified. Sympathetic neurons located in the celiac ganglion projects to visceral, vascular and glandular targets, and contribute to ovarian innervation, being the main source of sympathetic fibers. In the present study, we analyze the effects of elevated levels of exogenous estrogen during the prepubertal period in post-ganglionic sympathetic neurons. Estrogen exposure induced a significant increase in sympathetic celiac neuronal size and modified the expression of neurotrophin receptor p75. This change affected mainly small and medium size neurons. The effect of estrogens on innervation of celiac target organs was heterogeneous, inducing a significant increase in catecholaminergic innervation of the ovary, but not of the pyloric muscular layers. These findings further support the role of estrogen as a modulator of neuronal plasticity and suggest that estrogen could modify some features involved in the relation between sympathetic immature peripheral neurons and their target organs throughout a neurotrophin-dependent mechanism.

Background: The p75 neurotrophin receptor (p75NTR) is a death factor (apoptosis-promoting protein) that belongs to the tumor necrosis factor receptor superfamily of membrane proteins. In the murine hair follicle (HF) model, p75NTR plays a critical role during HF morphogenesis, functioning as a receptor that negatively controls HF development. p75NTR signaling is involved in the control of keratinocyte apoptosis during catagen. To date, knowledge about the expression pattern of p75NTR protein in human scalp skin and HFs is limited. In this investigation we hypothesized that p75NTR protein is expressed in human scalp skin and its expression in HFs fluctuates with the transitions from anagen --> catagen --> telogen stages., Methods: To test this hypothesis, the immunoreactivity of p75NTR protein was examined in human scalp skin by immunofluorescent and immunoalkaline phosphatase methods. A total of 50 normal-appearing human scalp skin biopsy specimens were examined (healthy women age 53-57 years). In each case, 50 HFs were analyzed (35, 10, and 5 follicles in anagen, catagen, and telogen, respectively)., Results: We found variations in p75NTR protein expression with HF cycling. p75NTR expression was negligible in early, mid, and mature anagen and weak during late anagen. p75NTR expression was moderate during anagen-catagen transition. It was strong in both catagen and telogen HF. Also, p75NTR protein expression was strong in the stratum corneum (epidermis), dermal fibroblasts, blood vessels, nerve endings, adipocytes, and both sebaceous and sweat glands., Limitations: Our knowledge about other proteins (prosurvival and pro-apoptotic molecules) interacting with p75 is incomplete., Conclusions: Our investigation reports, for the first time, the expression patterns of p75NTR in human scalp skin and HFs. p75NTR protein expression exhibited significant hair cycle-dependent fluctuation, suggesting a possible role in human HF biology.

The study was to evaluate the therapeutic benefit of transplanted bone mesenchymal stem cells (BMSCs) transfected never growth factor (NGF) gene and GFP gene (as a reporter gene), in treating the rat with fimbria-fornix lesion. After transduction of NGF gene via recombinant retroviral vectors into the rat BMSCs, BMSCs were therefore transformed into the GFP-NGF positive BMSCs, nearly 100% of BMSCs expressed NGF, and then transplanted into basal forebrain of rat with fimbria-fornix lesion. After 2 weeks post-transplantation, the GFP-NGF positive BMSCs survive and fuse in vivo with astroglia or NGFR p75 positive neurons in the basal forebrain, no evidence of transdifferentiation was observed in this study. The number of NGFR p75 positive neurons in basal forebrain of NGF group was significantly higher than those of the void plasmid group (p < 0.05) or the PBS group (p < 0.01). These results indicate that the GFP-NGF positive BMSCs provide, by way of paracrine, NGF that effectively perform the functions of neuroprotection, which cell fusion may be also contribute to.

Background: The purpose of this study was to elucidate the expression of p75 nerve growth factor receptor (p75NGFR) in human cross-facial nerve grafts and to compare the immunohistological findings with patient data and the functional outcome in facial reanimation., Materials and Methods: The study comprised 37 sural nerve graft specimens. All of the patients had long-lasting complete facial paralysis and were operated on by the standard two-stage procedure involving cross-facial nerve grafts and microneurovascular muscle transfer. Nerve biopsies were taken 4 to 20 months (mean, 8 months) after the cross-facial nerve grafting. Immunohistochemistry for p75NGFR as well as for Schwann cells (S-100; Dako, Glostrup, Denmark) and for Neurofilament-200 (NF-200; Boehringer, Mannheim, Germany) was performed., Results: In graft biopsies, the mean number of NF-200-positive axons amounted to 38% (range, 6-81%) of that in control samples. Further, regenerated axons were thinner than in control samples. Morphologically, the grafted nerves were characterized by fibrosis and invasion of inflammatory cells. A longer time between cross-facial nerve grafting and biopsy sampling correlated with a higher number of viable axons (NF-200) (P = 0.002). In all cases, expression of p75NGF receptor was clearly higher at the distal end of the grafted nerve. Expression of p75NGFR was lower in older than in younger patients (P = 0.003). A high expression of p75NGFR was often seen with better function of the transplanted muscle., Conclusion: Increased expression of p75NGFR in human nerve grafts was noted, especially in younger patients. We suggest that p75NGFR expression might be a contributing factor in a successful axonal regeneration and eventual recovery of muscle function.

Background: Neurotrophin receptor signaling regulates proliferation, differentiation and death of neuronal cells. Expression of Trk receptors has been implicated in the pathogenesis and prognosis of embryonal tumors, including neuroblastoma, nephroblastoma, and medulloblastoma., Procedure: We analyzed TrkA, TrkB, TrkC, and p75 expression using semi-quantitative RT-PCR in 23 retinoblastomas and 8 retinoblastoma cell lines. Comparison of mRNA expression with clinical variables as well as the proliferation (PI) and apoptotic index (AI) of the tumor, was performed by Pearson correlation analysis and two-sample t-test., Results: Almost all tumor samples and cell lines demonstrated high expression of all Trk receptors. Expression of TrkB and its ligand, BDNF, was most pronounced, suggesting TrkB to be the major Trk receptor involved in retinoblastoma biology. In contrast, p75 expression was substantially reduced in a subset of tumors and cell lines, in particular compared to its expression in normal retina. Tumors with infiltrative growth demonstrated significantly lower relative levels of TrkC expression than localized tumors (P = 0.004). High expression of TrkA was associated with a higher AI (P = 0.04), and high expression of TrkC was associated with a younger age of the patients (P = 0.03). Inhibition of Trk signaling by K252a resulted in marked growth inhibition of retinoblastoma cells in vitro., Conclusions: Our findings suggest a role for neurotrophin signaling in the biology of retinoblastoma. General Trk inhibitors are effective in decreasing growth rates of retinoblastoma cells in vitro, and should be evaluated in in vivo studies., ((c) 2007 Wiley-Liss, Inc.)

Purpose: We assessed the treatment effect of the aldose reductase inhibitor ONO-2235 (China Chemical and Pharmaceutical, Taipei, Taiwan) on diabetes associated alterations in bladder nerve growth factor and the nerve growth factor neurotrophin receptor p75 mRNA expressions using the streptozotocin (Sigma) induced diabetic rat model., Materials and Methods: Male Wistar rats were divided into 3 groups, including group 1--vehicle treated normal rats, group 2--vehicle treated 9-week streptozotocin diabetic rats and group 3--ONO-2235 treated 9-week streptozotocin diabetic rats. In vivo cystometry was performed using anesthesia. Bladder nerve growth factor levels were measured by enzyme linked immunosorbent assay. Expression of the mRNA encoding nerve growth factor and neurotrophin receptor p75 in the rat bladder was studied using reverse transcriptase-polymerase chain reaction., Results: Cystometry showed increased bladder capacity and decreased emptying function in diabetic rats. ONO-2235 treatment improved voiding volume, voiding fraction and residual volume. The nerve growth factor concentration in streptozotocin induced diabetic rat bladders was significantly lower than the control level in 8 experiments each (mean +/- SEM 45.78 +/- 4.36 and 96.44 +/- 8.73 pg/microg protein, respectively, p <0.01). The mRNA expression of bladder nerve growth factor and neurotrophin receptor p75 in diabetic rats was significantly decreased compared to that in controls in 8 experiments each (p <0.01 and <0.001, respectively). Treatment with ONO-2235 did not significantly change the blood sugar level in diabetic rats. However, administration of the drug significantly increased the bladder nerve growth factor concentration as well as nerve growth factor mRNA and neurotrophin receptor p75 mRNA expression to normal levels in 8 experiments each (p <0.01, <0.01 and <0.001, respectively)., Conclusions: ONO-2235 improved bladder emptying function and restored the decreased genetic expression of bladder nerve growth factor and neurotrophin receptor p75 in 9-week streptozotocin induced diabetic rats, indicating involvement of the sorbitol pathway in the genetic down-regulations of nerve growth factor and p75(NTR) during diabetic cystopathy.

Rationale: Neurotrophine tyrosine kinase receptors (NTR) are expressed in prostate carcinoma (PCa), and their distribution seems to be related to disease malignancy., Material and Methods: In this article we analyzed the expression of NTRK1 (TrkA), NTRK2 (TrkB), NTRK3 (TrkC), and p75NTR in a 102 patient cohort with clinically localized tumors, which had been surgically treated with radical prostatectomy (RP). Among these, 61 patients received RP as sole treatment, and 41 patients received neoadjuvant hormone therapy (NHT) for 120 days with bicalutamide 150 mg/day. In addition, we analyzed the NTR expression in vitro in the androgen receptor positive, androgen-sensitive cell strains derived from CWR22R., Results and Conclusions: We demonstrated that: (i) TrkA and TrkC levels were significantly upmodulated, whereas (ii) p75NTR seemed to be reduced, and (iii) TrkB expression seemed to be not affected by NHT. TrkA were constitutively activated when its levels were very high. In vitro studies showed that the dehydrotestosterone (DHT) was able to maintain low TrkA and TrkC protein levels. Conversely, DHT was able to maintain p75NTR at high levels. Bicalutamide treatment induced TrkA and TrkC and reduced p75NTR expression. Antiproliferative effects of CEP701 were dependent to TrkA levels. A therapeutical effect of CEP701 was seen in all culture conditions, and bicalutamide seemed to sensitize prostate cancer cells to the effects of a pan TrkA inhibitor CEP701, suggesting that a sequential therapy between these drugs could further increase the efficacy of Trk inhibition.

Aims/hypothesis: The p75 neurotrophin receptor (p75NTR) has been shown to appear in the plasma of diabetic rats, possibly indicating diabetic neuropathy. The aim of this study was to use a semi-quantitative assay for human plasma p75NTR to investigate whether this receptor is a marker of peripheral diabetic neuropathy (DPN) and autonomic cardiovascular neuropathy (CAN) in type 2 diabetic patients., Subjects and Methods: Eighty type 2 diabetic patients and 25 controls without diabetes were analysed for p75NTR immunoreactivity by western blot analysis. DPN was assessed using the Neuropathy Disability Score (NDS). Cardiovascular autonomic function was detected using a standardised analysis of heart rate variability., Results: Three distinct p75NTR signals were detectable in human plasma at approximately 75, approximately 51 and approximately 24 kDa, representing the full length receptor (FL) and its intracellular domain (ICD) and extracellular domain (ECD), respectively. Levels of total plasma p75NTR immunoreactivity in patients with type 2 diabetes were similar to those in controls. Type 2 diabetic patients had significantly higher plasma levels of ICD and lower levels of ECD. However, there were no correlations of total p75NTR immunoreactivity or ECD or ICD immunoreactivity with NDS or aspects of CAN., Conclusions/interpretation: Levels of the ECD of p75NTR are reduced and levels of the ICD are increased in the plasma of type 2 diabetic patients. None of the p75NTR subunits identified in human plasma seem to be a marker of peripheral or autonomic neuronal function in patients with type 2 diabetes.

In the months following transection of adult rat peripheral nerve some sensory neurons undergo apoptosis. Two weeks after sciatic nerve transection some neurons in the L4 and L5 dorsal root ganglia begin to show immunoreactivity for nestin, a filament protein expressed by neuronal precursors and immature neurons, which is stimulated by neurotrophin-3 (NT-3) administration. The aim of this study was to examine whether NT-3 administration could be compensating for decreased production of neurotrophins or their receptors after axotomy, and to determine the effect on nestin synthesis. The levels of mRNA in the ipsilateral and contralateral L4 and L5 dorsal root ganglia were analyzed using real-time polymerase chain reaction, 1 day, 1, 2 and 4 weeks after unilateral sciatic nerve transection and NT-3 or vehicle administration via s.c. micro-osmotic pumps. In situ hybridization was used to identify which cells and neurons expressed mRNAs of interest, and the expression of full-length trkC and p75NTR protein was investigated using immunohistochemistry. Systemic NT-3 treatment increased the expression of brain-derived neurotrophic factor, nestin, trkA, trkB and trkC mRNA in ipsilateral ganglia compared with vehicle-treated animals. Some satellite cells surrounding neurons expressed trkA and trkC mRNA and trkC immunoreactivity. NT-3 administration did not affect neurotrophin mRNA levels in the contralateral ganglia, but decreased the expression of trkA mRNA and increased the expression of trkB mRNA and p75NTR mRNA and protein. These data suggest that systemically administered NT-3 may counteract the decrease, or even increase, neurotrophin responsiveness in both ipsi- and contralateral ganglia after nerve injury.

Unlike the mechanisms involved in the death of neuronal cell bodies, those causing the elimination of processes are not well understood owing to the lack of suitable experimental systems. As the neurotrophin receptor p75(NTR) is known to restrict the growth of neuronal processes, we engineered mouse embryonic stem (ES) cells to express an Ngfr (p75(NTR)) cDNA under the control of the Mapt locus (the gene encoding tau), which begins to be active when ES cell-derived progenitors start elongating processes. This caused a progressive, synchronous degeneration of all processes, and a prospective proteomic analysis showed increased levels of the sugar-binding protein galectin-1 in the p75(NTR)-engineered cells. Function-blocking galectin-1 antibodies prevented the degeneration of processes, and recombinant galectin-1 caused the processes of wild-type neurons to degenerate first, followed by the cell bodies. In vivo, the application of a glutamate receptor agonist, a maneuver known to upregulate p75(NTR), led to an increase in the amount of galectin-1 and to the degeneration of neurons and their processes in a galectin-1-dependent fashion. Section of the sciatic nerve also rapidly upregulated levels of p75(NTR) and galectin-1 in terminal Schwann cells, and the elimination of nerve endings was delayed at the neuromuscular junction of mice lacking Lgals1 (the gene encoding galectin-1). These results indicate that galectin-1 actively participates in the elimination of neuronal processes after lesion, and that engineered ES cells are a useful tool for studying relevant aspects of neuronal degeneration that have been hitherto difficult to analyze.

Zinc release is a primary mediator of neuronal death. Here we show that zinc-mediated death of neurons in vitro is dependent on nerve growth factor (NGF) stimulation and does not occur in response to exposure to leukemia inhibitory factor. NGF priming is regulated, not by the traditional neurotrophin death receptor, p75NTR, but by TrkA, in a protein- and mRNA synthesis-dependent manner. Furthermore, Trk signaling promotes raised free intracellular zinc, mediating neuronal death after extracellular application of zinc. Thus, regulators of Trk signaling provide attractive targets for future treatment of zinc-associated neurological diseases, including stroke, epilepsy and brain trauma.

The neurotrophin receptor p75 (p75NTR) is expressed by both neurons and glia. Nerve injury triggers up-regulation of p75NTR in Schwann cells (SC) but not in central glia. In contrast to neuronal p75NTR, which mediates negative signals from myelin-associated proteins resulting in neurite collapse, glial p75NTR may play a positive role in nerve regeneration by forming neurotrophin chemoattractant gradients or by competitively antagonizing the NOGO/NgR/LINGO-1 signal through cell-cell contact or regulated intramembranous proteolysis (RIP) of p75NTR. This piece presents some recent evidence supporting this hypothesis., (Copyright (c) 2007 Wiley-Liss, Inc.)

First and second generation antipsychotics (FGAs and SGAs) ameliorate psychotic symptoms of schizophrenia, however, their chronic effects on information processing and memory function (i.e. key determinants of long term functional outcome) are largely unknown. In this rodent study the effects of different time periods (ranging from 2 weeks to 6 months) of oral treatment with the FGA, haloperidol (2.0 mg/kg/day), or the SGA, risperidone (2.5 mg/kg/day) on a water maze repeated acquisition procedure, the levels of nerve growth factor receptors, and two important cholinergic proteins, the vesicular acetylcholine transporter and the high affinity choline transporter were evaluated. The effects of the antipsychotics on a spontaneous novel object recognition procedure were also assessed during days 8-14 and 31-38 of treatment. Haloperidol (but not risperidone) was associated with impairments in water maze hidden platform trial performance at each of the time periods evaluated up to 45 days, but not when tested during days 83-90. In contrast, risperidone did not impair water maze task performance at the early time periods and it was actually associated with improved performance during the 83-90 day period. Both antipsychotics, however, were associated with significant water maze impairments during the 174-180 day period. Further, haloperidol was associated with decrements in short delay performance in the spontaneous novel object recognition task during both the 8-14 and 31-38 day periods of treatment, while risperidone was associated with short delay impairment during the 31-38 day time period. Both antipsychotics were also associated with time dependent alterations in the vesicular acetylcholine transporter, the high affinity choline transporter, as well as tyrosine kinase A, and p75 neurotrophin receptors in specific brain regions. These data from rats support the notion that while risperidone may hold some advantages over haloperidol, both antipsychotics can produce time-dependent alterations in neurotrophin receptors and cholinergic proteins as well as impairments in the performance of tasks designed to assess spatial learning and episodic memory.

Gene transfer into human CD34+ haematopoietic progenitor cells (HPC) and multi-potent mesenchymal stromal cells (MSC) is an essential tool for numerous in vitro and in vivo applications including therapeutic strategies, such as tissue engineering and gene therapy. Virus based methods may be efficient, but bear risks like tumorigenesis and activation of immune responses. A safer alternative is non-viral gene transfer, which is considered to be less efficient and accomplished with high cell toxicity. The truncated low affinity nerve growth factor receptor (ALNGFR) is a marker gene approved for human in vivo application. Human CD34+ HPC and human MSC were transfected with in vitro-transcribed mRNA for DeltaLNGFR using the method of nucleofection. Transfection efficiency and cell viability were compared to plasmid-based nucleofection. Protein expression was assessed using flow cytometry over a time period of 10 days. Nucleofection of CD34+ HPC and MSC with mRNA resulted in significantly higher transfection efficiencies compared to plasmid transfection. Cell differentiation assays were performed after selecting DeltaLNGFR positive cells using a fluorescent activating cell sorter. Neither cell differentiation of MSC into chondrocytes, adipocytes and osteoblasts, nor differentiation of HPC into burst forming unit erythroid (BFU-E) colony forming unit-granulocyte, erythrocyte, macrophage and megakaryocyte (CFU-GEMM), and CFU-granulocyte-macrophage (GM) was reduced. mRNA based nucleofection is a powerful, highly efficient and non-toxic approach for transient labelling of human progenitor cells or, via transfection of selective proteins, for transient manipulation of stem cell function. It may be useful to transiently manipulate stem cell characteristics and thus combine principles of gene therapy and tissue engineering.

Objective: To study the effects of lead acetate on the expression of brain-derived neurotropic factor (BDNF) and its receptor P75NTR in rat brain., Methods: Lead acetate was given to SD rats by intraperitoneal injection (ip) for 5 days at the dosage of 25, 50 and 100mg/kg body weight respectively. The contents of lead in serum, cerebral cortex and hippocampus were measured by atomic absorption spectrophotochemistry. The levels of BDNF mRNA and protein expression in cerebral cortex and hippocampus were observed by RT-PCR and immunohistochemistry, respectively. The levels of P75NTR protein expression in rat brain were measured by immunohistochemistry., Results: Compared with the control, the contents of lead were significantly increased in serum, cerebral cortex and hippocampus in the treatment groups respectively (P < 0.01, P < 0.05). The BDNF mRNA expression in the cerebral cortex (0.52 +/- 0.05, 0.33 +/- 0.03) and hippocampus (0.77 +/- 0.10, 0.92 +/- 0.08) of 50, 100 mg/kg treated groups was significantly higher than that of the control group (0.52 +/- 0.05, 0.33 +/- 0.03), respectively (P < 0.05). The results of immunohistochemistry showed that the area density of BDNF protein in cerebral cortex of every treatment group (0.040 +/- 0.027, 0.048 +/- 0.027, 0.086 +/- 0.040) was significantly increased whereas the average gray value (187.11 +/- 11.15, 180.53 +/- 5.82, 180.15 +/- 8.01) was significantly lower than that of the control (0.026 +/- 0.005, 204.98 +/- 3.45) (P < 0.05, P < 0.01). The area density of BDNF protein in hippocampus of every treatment group was 0.040 +/- 0.027, 0.048 +/- 0.027, 0.086 +/- 0.040, respectively, which was significantly increased compared with the control (0.045 +/- 0.019, P < 0.05). The average gray value of BDNF protein in hippocampus (181.03 +/- 5.16, 171.25 +/- 12.65) of 50, 100 mg/kg were significantly lower than that of the control (198.98 +/- 6.40, P < 0.01). There was no positive expression of P75NTR protein in the control and 25 mg/kg body weight groups. The positive expression of P75NTR protein was detected in 50 and 100 mg/kg body weight groups., Conclusion: Lead can increase the BDNF and P75NTR expression in rat brain which might play an important role in the neural damage and repair.

Thyroid hormone insufficiency adversely affects cortical development; however, its effect on apoptosis modulation during cerebral cortex development is not understood. We investigated the effect of perinatal hypothyroidism on apoptosis and its mechanisms during rat cerebral cortex development. Primary hypothyroidism was induced by feeding methimazole (0.025% wt/vol) in the drinking water to pregnant and lactating rats and continued until the animals were killed (hypothyroid group). Cerebral cortices from pups were harvested at different postnatal ages (postnatal d 0, 8, 16, and 24 and adult), and apoptosis was quantitated by terminal deoxynucleotide transferase-mediated dUTP nick end labeling and cleaved caspase-3 immunoreactivity. Compared with the euthyroid, primary somatosensory cortex (S1) in the hypothyroid group exhibited enhanced apoptosis. In S1 of euthyroid rats, apoptotic cells were mostly found in cortical layers I-III and the proportion of apoptotic cells enhanced significantly in the hypothyroid group (P < 0.001). Most of the apoptotic cells were neurons, as assessed by double immunolabeling. A significantly increased activation of caspase-3 and -7, decreased levels of antiapoptotic proteins Bcl-2 and Bcl-x(L), and increased levels of proapoptotic protein Bax was observed in the developing cerebral cortex of hypothyroid rats, compared with the euthyroid (P < 0.001). In addition, hypothyroidism significantly elevated the levels of 53-kDa pro-nerve growth factor (P < 0.001) and p75 neurotrophin receptor (P < 0.001) and decreased TrkA expression. Taken together, we provide evidence for the possible contribution of pro-nerve growth factor/p75 neurotrophin receptor pathway in hypothyroidism-enhanced apoptosis during rat cortical development. Thus, the present study may help in explaining the mechanism of the deleterious effect of thyroid hormone deficiency on cerebral cortex development in children.

Sensory hair cells of the mammalian organ of Corti in the inner ear do not regenerate when lost as a consequence of injury, disease, or age-related deafness. This contrasts with other vertebrates such as birds, where the death of hair cells causes surrounding supporting cells to re-enter the cell cycle and give rise to both new hair cells and supporting cells. It is not clear whether the lack of mammalian hair cell regeneration is due to an intrinsic inability of supporting cells to divide and differentiate or to an absence or blockade of regenerative signals. Here we show that post-mitotic supporting cells purified from the postnatal mouse cochlea retain the ability to divide and trans-differentiate into new hair cells in culture. Furthermore, we show that age-dependent changes in supporting cell proliferative capacity are due in part to changes in the ability to downregulate the cyclin-dependent kinase inhibitor p27(Kip1) (also known as Cdkn1b). These results indicate that postnatal mammalian supporting cells are potential targets for therapeutic manipulation.

Nerve growth factor (NGF) promotes proliferation via its high affinity receptor (TrkA). Its precursor proNGF promotes apoptosis via the pan-neurotrophin-receptor p75. Recently, we have identified NGF and p75 as important hair growth terminators. However, if proNGF is involved or if NGF can also promote hair growth via TrkA is unclear. By RT-PCR we found that NGF/proNGF mRNA levels peak during early anagen in murine back skin, whereas NGF/proNGF protein levels peak during catagen, indicating high turnover in early anagen and protein accumulation in catagen. By immunohistochemistry, NGF and TrkA are found in the proliferating compartments of the epidermis and hair follicle throughout the cycle. In contrast, strong proNGF is found in the highly differentiated inner root sheath and adjacent to the p75+ regressing epithelial strand in catagen. Commercial 7S NGF, which contains both NGF and proNGF, promotes anagen development in organ-cultured early anagen mouse skin, whereas it promotes catagen development in late anagen skin. Together, our findings suggest an anagen-promoting or anagen-supporting role for NGF/TrkA, and a catagen-promoting role for proNGF/p75 interactions. This has important implications for the future design of specific neurotrophin receptor ligands as novel pharmaceuticals in the modification of tissue remodeling processes such as hair growth or wound healing.