NGF mRNA expression in developing cutaneous epithelium related to innervation density

Development ◽  
1990 ◽  
Vol 110 (2) ◽  
pp. 515-519 ◽  
Author(s):  
S. Harper ◽  
A.M. Davies

To determine if the initial level of NGF mRNA in developing cutaneous epithelium is correlated with its final innervation density, we measured the concentration of NGF mRNA in the epithelia of the maxillary, mandibular and ophthalmic territories of trigeminal ganglion in the embryonic mouse. At the onset of neuronal death in the ganglion there were marked differences in the concentration of NGF mRNA in these epithelia: the level was highest in the epithelium of the densely innervated maxillary territory, it was lower in the epithelium of the moderately innervated mandibular territory and was lowest in the epithelium of the sparsely innervated ophthalmic territory. These regional differences in the level of NGF mRNA during the early stages of target field innervation suggest that the level of NGF production in target field cells, rather than regional differences in the access of innervating neurons to NGF, governs the number of neurons that survive. Because the same percentage cell death occurs in each of the subsets of trigeminal neurons that innervate the maxillary, mandibular and ophthalmic territories, regional differences in NGF synthesis are not responsible for establishing differences in innervation density, rather they maintain differences that arise earlier in development.


Development ◽  
1996 ◽  
Vol 122 (10) ◽  
pp. 3255-3261 ◽  
Author(s):  
L.G. Pinon ◽  
L. Minichiello ◽  
R. Klein ◽  
A.M. Davies

The sensory neurons of the embryonic mouse trigeminal ganglion are supported in culture by different neurotrophins at successive stages of development. Initially the neurons survive in response to BDNF and NT3 and later switch to becoming NGF-dependent (Buchman, V. I. and Davies, A. M. (1993), Development 118, 989–1001). To determine if this in vitro switch in neurotrophin responsiveness is physiologically relevant, we studied the timing of neuronal death in the trigeminal ganglia of embryos that are homozygous for null mutations in the trkA, trkB and trkC genes, which encode receptor tyrosine kinases for NGF, BDNF and NT3, respectively. In wild-type embryos, the number of pyknotic nuclei increased from E11 to peak between E13 and E14, and decreased gradually at later ages, becoming negligible by birth. Neuronal death in the trigeminal ganglia of trkA−/− embryos also peaked between E13 and E14, but was almost threefold greater than in wild-type embryos at this stage. Whereas there was no significant difference between the number of pyknotic nuclei in trkA−/− and wild-type embryos at E11 and E12, there was a substantial increase in the number of pyknotic nuclei in the trigeminal ganglia of trkB−/− at these earlier stages. Counts of the total number of neurons in E13 trigeminal ganglia revealed a marked decrease in trkB−/− but not trkA−/− or trkC−/− embryos. Consistent with the later onset of excessive neuronal death in trkA−/− embryos, there was a marked decrease in the neuronal complement of the trigeminal ganglia of trkA−/− embryos at E15. These results demonstrate that TrkB signalling is required for the in vivo survival of many trigeminal neurons during the early stages of target field innervation before they become NGF-dependent.



Development ◽  
1999 ◽  
Vol 126 (19) ◽  
pp. 4365-4373 ◽  
Author(s):  
Y. Enokido ◽  
S. Wyatt ◽  
A.M. Davies

Previous studies have shown that most neurons in cultures established during the early stages of neurogenesis in the embryonic mouse trigeminal ganglion are supported by BDNF whereas most neurons cultured from older ganglia survive with NGF. To ascertain to what extent these developmental changes in neurotrophin responsiveness result from separate phases of generation of BDNF- and NGF-responsive neurons or from a developmental switch in the response of neurons from BDNF to NGF, we administered BrdU to pregnant mice at different stages of gestation to identify neurons born at different times and studied the survival of labelled neurons in dissociated cultures established shortly after BrdU administration. Most early-generated neurons responded to BDNF, neurons generated at intermediate times responded to both factors and late-generated neurons responded to NGF, indicating that there are overlapping phases in the generation of BDNF- and NGF-responsive neurons and that late-generated neurons do not switch responsiveness from BDNF to NGF. To ascertain if early-generated neurons do switch their response to neurotrophins during development, we used repeated BrdU injection to label all neurons generated after an early stage in neurogenesis and studied the neurotrophin responsiveness of the unlabelled neurons in cultures established after neurogenesis had ceased. The response of these early-generated neurons had decreased to BDNF and increased to NGF, indicating that at least a proportion of early-generated neurons switch responsiveness to neurotrophins in vivo. Because early-generated neurons do not switch responsiveness from BDNF to NGF in long-term dissociated cultures, we cultured early trigeminal ganglion explants with and without their targets for 24 hours before establishing dissociated cultures. This period of explant culture was sufficient to enable many early-generated neurons to switch their response from BDNF to NGF and this switch occurred irrespective of presence of target tissue. Our findings conclusively demonstrate for the first time that individual neurons switch their neurotrophin requirements during development and that this switch depends on cell interactions within the ganglion. In addition, we show that there are overlapping phases in the generation of BDNF- and NGF-responsive neurons in the trigeminal ganglion.



Development ◽  
1993 ◽  
Vol 118 (3) ◽  
pp. 989-1001 ◽  
Author(s):  
V.L. Buchman ◽  
A.M. Davies

To investigate if different neurotrophins regulate the survival of neurons at successive developmental stages, we studied the effect of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) on the survival of mouse trigeminal neurons at closely staged intervals in development. We show that during the earliest stages of target field innervation trigeminal neurons display a transitory survival response to BDNF and NT-3. This response is lost as the neurons become NGF-dependent shortly before neuronal death begins in the trigeminal ganglion. BDNF and NT-3 mRNAs are expressed in the peripheral trigeminal target field before the arrival of the earliest axons and the onset of NGF mRNA expression. The levels of BDNF and NT-3 mRNAs peak during the early stages of target field innervation and decline shortly after the loss of neuronal responsiveness to BDNF and NT-3. Our study provides the first clear evidence that different target-derived neurotrophins can act sequentially to promote the survival of developing neurons.



2020 ◽  
Vol 401 (10) ◽  
pp. 1153-1165 ◽  
Author(s):  
Antônio F. da Silva Filho ◽  
Lucas B. Tavares ◽  
Maira G. R. Pitta ◽  
Eduardo I. C. Beltrão ◽  
Moacyr J. B. M. Rêgo

AbstractPancreatic ductal adenocarcinoma is one of the most aggressive tumors with a microenvironment marked by hypoxia and starvation. Galectin-3 has been evaluated in solid tumors and seems to present both pro/anti-tumor effects. So, this study aims to characterize the expression of Galectin-3 from pancreatic tumor cells and analyze its influence for cell survive and motility in mimetic microenvironment. For this, cell cycle and cell death were accessed through flow cytometry. Characterization of inside and outside Galectin-3 was performed through Real-Time Quantitative Reverse Transcription PCR (qRT-PCR), immunofluorescence, Western blot, and ELISA. Consequences of Galectin-3 extracellular inhibition were investigated using cell death and scratch assays. PANC-1 showed increased Galectin-3 mRNA expression when cultivated in hypoxia for 24 and 48 h. After 24 h in simultaneously hypoxic/deprived incubation, PANC-1 shows increased Galectin-3 protein and secreted levels. For Mia PaCa-2, cultivation in deprivation was determinant for the increasing in Galectin-3 mRNA expression. When cultivated in simultaneously hypoxic/deprived condition, Mia PaCa-2 also presented increasing for the Galectin-3 secreted levels. Treatment of PANC-1 cells with lactose increased the death rate when cells were incubated simultaneously hypoxic/deprived condition. Therefore, it is possible to conclude that the microenvironmental conditions modulate the Galectin-3 expression on the transcriptional and translational levels for pancreatic cancer cells.



2009 ◽  
Vol 30 (3) ◽  
pp. 461-467
Author(s):  
Hiroyuki Ichikawa ◽  
Bing-Ran Zhao ◽  
Mitsuhiro Kano ◽  
Yoshinaka Shimizu ◽  
Toshihiko Suzuki ◽  
...  


2012 ◽  
Vol 108 (2) ◽  
pp. 431-440 ◽  
Author(s):  
Oana Covasala ◽  
Sören L. Stirn ◽  
Stephanie Albrecht ◽  
Roberto De Col ◽  
Karl Messlinger

Calcitonin gene-related peptide (CGRP) is regarded as a key mediator in the generation of primary headaches. CGRP receptor antagonists reduce migraine pain in clinical trials and spinal trigeminal activity in animal experiments. The site of CGRP receptor inhibition causing these effects is debated. Activation and inhibition of CGRP receptors in the trigeminal ganglion may influence the activity of trigeminal afferents and hence of spinal trigeminal neurons. In anesthetized rats extracellular activity was recorded from neurons with meningeal afferent input in the spinal trigeminal nucleus caudalis. Mechanical stimuli were applied at regular intervals to receptive fields located in the exposed cranial dura mater. α-CGRP (10−5 M), the CGRP receptor antagonist olcegepant (10−3 M), or vehicle was injected through the infraorbital canal into the trigeminal ganglion. The injection of volumes caused transient discharges, but vehicle, CGRP, or olcegepant injection was not followed by significant changes in ongoing or mechanically evoked activity. In animals pretreated intravenously with the nitric oxide donor glyceryl trinitrate (GTN, 250 μg/kg) the mechanically evoked activity decreased after injection of CGRP and increased after injection of olcegepant. In conclusion, the activity of spinal trigeminal neurons with meningeal afferent input is normally not controlled by CGRP receptor activation or inhibition in the trigeminal ganglion. CGRP receptors in the trigeminal ganglion may influence neuronal activity evoked by mechanical stimulation of meningeal afferents only after pretreatment with GTN. Since it has previously been shown that olcegepant applied to the cranial dura mater is ineffective, trigeminal activity driven by meningeal afferent input is more likely to be controlled by CGRP receptors located centrally to the trigeminal ganglion.



2016 ◽  
Vol 88 (suppl 1) ◽  
pp. 653-663 ◽  
Author(s):  
Dulce-Mariely Álvarez-Croda ◽  
Juan Santiago-García ◽  
Jesús S. Medel-Matus ◽  
Joel Martínez-Quiroz ◽  
Angel A. Puig-Lagunes ◽  
...  

The contribution of Interleukin-1β (IL-1β) to neuronal injury induced by status epilepticus (SE) in the immature brain remains unclear. The goal of this study was to determine the hippocampal expression of IL-1β and its type 1 receptor (IL-1RI) following SE induced by the lithium-pilocarpine model in fourteen-days-old rat pups; control animals were given an equal volume of saline instead of the convulsant. IL-1β and IL-1RI mRNA hippocampal levels were assessed by qRT-PCR 6 and 24 h after SE or control conditions. IL-1β and IL-1RI expression was detected in the dorsal hippocampus by immunohistochemical procedures; Fluoro-Jade B staining was carried out in parallel sections in order to detect neuronal cell death. IL-1β mRNA expression was increased 6 h following SE, but not at 24 h; however IL-1RI mRNA expression was unaffected when comparing with the control group. IL-1β and IL-1RI immunoreactivity was not detected in control animals. IL-1β and IL-1RI were expressed in the CA1 pyramidal layer, the dentate gyrus granular layer and the hilus 6 h after SE, whereas injured cells were detected 24 h following seizures. Early expression of IL-1β and IL-1RI in the hippocampus could be associated with SE-induced neuronal cell death mechanisms in the developing rat.



2006 ◽  
Vol 26 (9) ◽  
pp. 3550-3564 ◽  
Author(s):  
Brad E. Morrison ◽  
Nazanin Majdzadeh ◽  
Xiaoguang Zhang ◽  
Aaron Lyles ◽  
Rhonda Bassel-Duby ◽  
...  

ABSTRACT The expression of histone deacetylase-related protein (HDRP) is reduced in neurons undergoing apoptosis. Forced reduction of HDRP expression in healthy neurons by treatment with antisense oligonucleotides also induces cell death. Likewise, neurons cultured from mice lacking HDRP are more vulnerable to cell death. Adenovirally mediated expression of HDRP prevents neuronal death, showing that HDRP is a neuroprotective protein. Neuroprotection by forced expression of HDRP is not accompanied by activation of the phosphatidylinositol 3-kinase-Akt or Raf-MEK-ERK signaling pathway, and treatment with pharmacological inhibitors of these pathways fails to inhibit the neuroprotection by HDRP. Stimulation of c-Jun phosphorylation and expression, an essential feature of neuronal death, is prevented by HDRP. We found that HDRP associates with c-Jun N-terminal kinase (JNK) and inhibits its activity, thus explaining the inhibition of c-Jun phosphorylation by HDRP. HDRP also interacts with histone deacetylase 1 (HDAC1) and recruits it to the c-Jun gene promoter, resulting in an inhibition of histone H3 acetylation at the c-Jun promoter. Although HDRP lacks intrinsic deacetylase activity, treatment with pharmacological inhibitors of histone deacetylases induces apoptosis even in the presence of ectopically expressed HDRP, underscoring the importance of c-Jun promoter deacetylation by HDRP-HDAC1 in HDRP-mediated neuroprotection. Our results suggest that neuroprotection by HDRP is mediated by the inhibition of c-Jun through its interaction with JNK and HDAC1.



1976 ◽  
Vol 37 (2) ◽  
pp. 237-256 ◽  
Author(s):  
T.W. Sadler ◽  
D.M. Kochhar




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