Nejvíce citovaný článek - PubMed ID 17070499
Restoring wild-type conformation and DNA-binding activity of mutant p53 is insufficient for restoration of transcriptional activity
INTRODUCTION: The choroid plexus is located in the cerebral ventricles. It consists of a stromal core and a single layer of cuboidal epithelial cells that forms the blood-cerebrospinal barrier. The main function of the choroid plexus is to produce cerebrospinal fluid. Subarachnoid hemorrhage due to aneurysm rupture is a devastating type of hemorrhagic stroke. Following subarachnoid hemorrhage, blood and the blood degradation products that disperse into the cerebrospinal fluid come in direct contact with choroid plexus epithelial cells. The aim of the current study was to elucidate the pathophysiological cascades responsible for the inflammatory reaction that is seen in the choroid plexus following subarachnoid hemorrhage. METHODS: Subarachnoid hemorrhage was induced in rats by injecting non-heparinized autologous blood to the cisterna magna. Increased intracranial pressure following subarachnoid hemorrhage was modeled by using artificial cerebrospinal fluid instead of blood. Subarachnoid hemorrhage and artificial cerebrospinal fluid animals were left to survive for 1, 3, 7 and 14 days. Immunohistochemical staining of TLR4, TLR9, FPR2, CCL2, TNFα, IL-1β, CCR2 and CX3CR1 was performed on the cryostat sections of choroid plexus tissue. The level of TLR4, TLR9, FPR2, CCL2, TNFα, IL-1β was detected by measuring immunofluorescence intensity in randomly selected epithelial cells. The number of CCR2 and CX3CR1 positive cells per choroid plexus area was manually counted. Immunohistochemical changes were confirmed by Western blot analyses. RESULTS: Immunohistochemical methods and Western blot showed increased levels of TLR9 and a slight increase in TLR4 and FRP2 following both subarachnoid hemorrhage as well as the application of artificial cerebrospinal fluid over time, although the individual periods were different. The levels of TNFα and IL-1β increased, while CCL2 level decreased slightly. Accumulation of macrophages positive for CCR2 and CX3CR1 was found in all periods after subarachnoid hemorrhage as well as after the application of artificial cerebrospinal fluid. DISCUSSION: Our results suggest that the inflammation develops in the choroid plexus and blood-cerebrospinal fluid barrier in response to blood components as well as acutely increased intracranial pressure following subarachnoid hemorrhage. These pro-inflammatory changes include accumulation in the choroid plexus of pro-inflammatory cytokines, innate immune receptors, and monocyte-derived macrophages.
- Klíčová slova
- blood-cerebrospinal fluid barrier, choroid plexus, hydrocephalus, neuroinflammation, stroke, subarachnoid hemorrhage,
- Publikační typ
- časopisecké články MeSH
(1) Background: this prospective study was focused on detailed analysis of the mutation heterogeneity in colorectal lesions removed during baseline (index) colonoscopy to identify patients at high risk of early occurrence of metachronous adenomas. (2) Methods: a total of 120 patients after endoscopic therapy of advanced colorectal neoplasia size ≥10 mm (index lesion) with subsequent surveillance colonoscopy after 10-18 months were included. In total, 143 index lesions and 84 synchronous lesions in paraffin blocks were divided into up to 30 samples. In each of them, the detection of somatic mutations in 11 hot spot gene loci was performed. Statistical analysis to correlate the mutation profiles and the degree of heterogeneity of the lesions with the risk of metachronous adenoma occurrence was undertaken. (3) Results: mutation in exon 7 of the TP53 gene found in the index lesion significantly correlated with the early occurrence of metachronous adenoma (log-rank test p = 0.003, hazard ratio 2.73, 95% confidence interval 1.14-6.56). We did not find an association between the risk of metachronous adenomas and other markers monitored. (4) Conclusions: the findings of this study could lead to an adjustment of existing recommendations for surveillance colonoscopies in a specific group of patients with mutations in exon 7 of the TP53 gene in an index lesion, where a shortening of surveillance interval may be warranted.
- Klíčová slova
- TP53, colonoscopy, colorectal adenomas, colorectal cancer, index lesion, metachronous lesion, synchronous lesion, tumor heterogeneity,
- Publikační typ
- časopisecké články MeSH
Subarachnoid hemorrhage is a specific, life-threatening form of hemorrhagic stroke linked to high morbidity and mortality. It has been found that the choroid plexus of the brain ventricles forming the blood-cerebrospinal fluid barrier plays an important role in subarachnoid hemorrhage pathophysiology. Heme oxygenase-1 and biliverdin reductase are two of the key enzymes of the hemoglobin degradation cascade. Therefore, the aim of present study was to investigate changes in protein levels of heme oxygenase-1 and biliverdin reductase in the rat choroid plexus after experimental subarachnoid hemorrhage induced by injection of non-heparinized autologous blood to the cisterna magna. Artificial cerebrospinal fluid of the same volume as autologous blood was injected to mimic increased intracranial pressure in control rats. Immunohistochemical and Western blot analyses were used to monitor changes in the of heme oxygenase-1 and biliverdin reductase levels in the rat choroid plexus after induction of subarachnoid hemorrhage or artificial cerebrospinal fluid application for 1, 3, and 7 days. We found increased levels of heme oxygenase-1 and biliverdin reductase protein in the choroid plexus over the entire period following subarachnoid hemorrhage induction. The level of heme oxygenase-1 was the highest early (1 and 3 days) after subarachnoid hemorrhage indicating its importance in hemoglobin degradation. Increased levels of heme oxygenase-1 were also observed in the choroid plexus epithelial cells at all time points after application of artificial cerebrospinal fluid. Biliverdin reductase protein was detected mainly in the choroid plexus epithelial cells, with levels gradually increasing during subarachnoid hemorrhage. Our results suggest that heme oxygenase-1 and biliverdin reductase are involved not only in hemoglobin degradation but probably also in protecting choroid plexus epithelial cells and the blood-cerebrospinal fluid barrier from the negative effects of subarachnoid hemorrhage.
- Klíčová slova
- biliverdin reductase, choroid plexus, heme oxygenase-1, macrophages, subarachnoid hemorrhage,
- Publikační typ
- časopisecké články MeSH
p53 is one of the most studied tumor suppressor proteins that plays an important role in basic biological processes including cell cycle, DNA damage response, apoptosis, and senescence. The human TP53 gene contains alternative promoters that produce N-terminally truncated proteins and can produce several isoforms due to alternative splicing. p53 function is realized by binding to a specific DNA response element (RE), resulting in the transactivation of target genes. Here, we evaluated the influence of quadruplex DNA structure on the transactivation potential of full-length and N-terminal truncated p53α isoforms in a panel of S. cerevisiae luciferase reporter strains. Our results show that a G-quadruplex prone sequence is not sufficient for transcription activation by p53α isoforms, but the presence of this feature in proximity to a p53 RE leads to a significant reduction of transcriptional activity and changes the dynamics between co-expressed p53α isoforms.
- Klíčová slova
- p53 protein, protein-DNA interaction, transactivation potential,
- MeSH
- G-kvadruplexy * MeSH
- lidé MeSH
- nádorový supresorový protein p53 genetika metabolismus MeSH
- promotorové oblasti (genetika) genetika MeSH
- protein - isoformy genetika metabolismus MeSH
- proteiny regulující apoptózu genetika metabolismus MeSH
- protoonkogenní proteiny genetika metabolismus MeSH
- responzivní elementy genetika MeSH
- vazba proteinů MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- BBC3 protein, human MeSH Prohlížeč
- nádorový supresorový protein p53 MeSH
- protein - isoformy MeSH
- proteiny regulující apoptózu MeSH
- protoonkogenní proteiny MeSH
The tumor suppressor functions of p53 and its roles in regulating the cell cycle, apoptosis, senescence, and metabolism are accomplished mainly by its interactions with DNA. p53 works as a transcription factor for a significant number of genes. Most p53 target genes contain so-called p53 response elements in their promoters, consisting of 20 bp long canonical consensus sequences. Compared to other transcription factors, which usually bind to one concrete and clearly defined DNA target, the p53 consensus sequence is not strict, but contains two repeats of a 5'RRRCWWGYYY3' sequence; therefore it varies remarkably among target genes. Moreover, p53 binds also to DNA fragments that at least partially and often completely lack this consensus sequence. p53 also binds with high affinity to a variety of non-B DNA structures including Holliday junctions, cruciform structures, quadruplex DNA, triplex DNA, DNA loops, bulged DNA, and hemicatenane DNA. In this review, we summarize information of the interactions of p53 with various DNA targets and discuss the functional consequences of the rich world of p53 DNA binding targets for its complex regulatory functions.
- Klíčová slova
- consensus sequence, cruciform, local DNA structures, p53, protein-DNA interactions,
- MeSH
- DNA chemie metabolismus MeSH
- konformace nukleové kyseliny MeSH
- konformace proteinů MeSH
- konsenzuální sekvence MeSH
- lidé MeSH
- molekulární modely MeSH
- nádorový supresorový protein p53 chemie metabolismus MeSH
- sekvence aminokyselin MeSH
- vazba proteinů MeSH
- vazebná místa MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- DNA MeSH
- nádorový supresorový protein p53 MeSH
The primary sensory neurons of dorsal root ganglia (DRG) are a very useful model to study the neuronal regenerative program that is a prerequisite for successful axon regeneration after peripheral nerve injury. Seven days after a unilateral sciatic nerve injury by compression or transection, we detected a bilateral increase in growth-associated protein-43 (GAP-43) and superior cervical ganglion-10 (SCG-10) mRNA and protein levels not only in DRG neurons of lumbar spinal cord segments (L4-L5) associated with injured nerve, but also in remote cervical segments (C6-C8). The increase in regeneration-associated proteins in the cervical DRG neurons was associated with the greater length of regenerated axons 1 day after ulnar nerve crush following prior sciatic nerve injury as compared to controls with only ulnar nerve crush. The increased axonal regeneration capacity of cervical DRG neurons after a prior conditioning sciatic nerve lesion was confirmed by neurite outgrowth assay of in vitro cultivated DRG neurons. Intrathecal injection of IL-6 or a JAK2 inhibitor (AG490) revealed a role for the IL-6 signaling pathway in activating the pro-regenerative state in remote DRG neurons. Our results suggest that the pro-regenerative state induced in the DRG neurons non-associated with the injured nerve reflects a systemic reaction of these neurons to unilateral sciatic nerve injury.
- Klíčová slova
- GAP-43, IL-6, SCG-10, neurite outgrowth assay, primary sensory neurons, pro-regenerative state, ulnar nerve crush, unilateral nerve injury,
- Publikační typ
- časopisecké články MeSH
Unilateral sciatic nerve compression (SNC) or complete sciatic nerve transection (CSNT), both varying degrees of nerve injury, induced activation of STAT3 bilaterally in the dorsal root ganglia (DRG) neurons of lumbar (L4-L5) as well as cervical (C6-C8) spinal cord segments. STAT3 activation was by phosphorylation at the tyrosine-705 (Y705) and serine-727 (S727) positions and was followed by their nuclear translocation. This is the first evidence of STAT3(S727) activation together with the well-known activation of STAT3(Y705) in primary sensory neurons upon peripheral nerve injury. Bilateral activation of STAT3 in DRG neurons of spinal segments anatomically both associated as well as non-associated with the injured nerve indicates diffusion of STAT3 activation inducers along the spinal cord. Increased levels of IL-6 protein in the CSF following nerve injury as well as activation and nuclear translocation of STAT3 in DRG after intrathecal injection of IL-6 shows that this cytokine, released into the subarachnoid space can penetrate the DRG to activate STAT3. Previous results on increased bilateral IL-6 synthesis and the present manifestation of STAT3 activation in remote DRG following unilateral sciatic nerve injury may reflect a systemic reaction of the DRG neurons to nerve injury.
- Klíčová slova
- Dorsal root ganglia, Neuroinflammation, Peripheral nerve injury, Systemic reaction,
- MeSH
- aktivní transport - buněčné jádro MeSH
- buněčné jádro metabolismus MeSH
- fosforylace MeSH
- fosfoserin metabolismus MeSH
- fosfotyrosin metabolismus MeSH
- krysa rodu Rattus MeSH
- nemoci sedacího nervu metabolismus patologie MeSH
- nervové receptory metabolismus patologie MeSH
- potkani Wistar MeSH
- spinální ganglia metabolismus patologie MeSH
- transkripční faktor STAT3 chemie metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- fosfoserin MeSH
- fosfotyrosin MeSH
- Stat3 protein, rat MeSH Prohlížeč
- transkripční faktor STAT3 MeSH
p73 is a member of the p53 protein family and has essential functions in several signaling pathways involved in development, differentiation, DNA damage responses and cancer. As a transcription factor, p73 achieves these functions by binding to consensus DNA sequences and p73 shares at least partial target DNA binding sequence specificity with p53. Transcriptional activation by p73 has been demonstrated for more than fifty p53 targets in yeast and/or human cancer cell lines. It has also been shown previously that p53 binding to DNA is strongly dependent on DNA topology and the presence of inverted repeats that can form DNA cruciforms, but whether p73 transcriptional activity has similar dependence has not been investigated. Therefore, we evaluated p73 binding to a set of p53-response elements with identical theoretical binding affinity in their linear state, but different probabilities to form extra helical structures. We show by a yeast-based assay that transactivation in vivo correlated more with the relative propensity of a response element to form cruciforms than to its expected in vitro DNA binding affinity. Structural features of p73 target sites are therefore likely to be an important determinant of its transactivation function.
- MeSH
- aktivace transkripce MeSH
- konformace nukleové kyseliny MeSH
- kvasinky genetika metabolismus MeSH
- lidé MeSH
- nádorový supresorový protein p53 metabolismus MeSH
- obrácené repetice * MeSH
- protein p73 chemie genetika metabolismus MeSH
- sekvence nukleotidů MeSH
- vazba proteinů MeSH
- vazebná místa * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- nádorový supresorový protein p53 MeSH
- protein p73 MeSH
p53 plays critical roles in regulating cell cycle, apoptosis, senescence and metabolism and is commonly mutated in human cancer. These roles are achieved by interaction with other proteins, but particularly by interaction with DNA. As a transcription factor, p53 is well known to bind consensus target sequences in linear B-DNA. Recent findings indicate that p53 binds with higher affinity to target sequences that form cruciform DNA structure. Moreover, p53 binds very tightly to non-B DNA structures and local DNA structures are increasingly recognized to influence the activity of wild-type and mutant p53. Apart from cruciform structures, p53 binds to quadruplex DNA, triplex DNA, DNA loops, bulged DNA and hemicatenane DNA. In this review, we describe local DNA structures and summarize information about interactions of p53 with these structural DNA motifs. These recent data provide important insights into the complexity of the p53 pathway and the functional consequences of wild-type and mutant p53 activation in normal and tumor cells.
- Klíčová slova
- local DNA structures, p53 protein, protein-DNA interactions,
- MeSH
- B-DNA MeSH
- DNA chemie genetika metabolismus MeSH
- konformace nukleové kyseliny * MeSH
- lidé MeSH
- nádorový supresorový protein p53 chemie metabolismus MeSH
- vazba proteinů MeSH
- vazebná místa MeSH
- vztahy mezi strukturou a aktivitou MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- B-DNA MeSH
- DNA MeSH
- nádorový supresorový protein p53 MeSH
- triplex DNA MeSH Prohlížeč
BACKGROUND: Interaction of CD200 with its receptor CD200R has an immunoregulatory role and attenuates various types of neuroinflammatory diseases. METHODS: Immunofluorescence staining, western blot analysis, and RT-PCR were used to investigate the modulatory effects of CD200 fusion protein (CD200Fc) on activation of microglia and astrocytes as well as synthesis of pro- (TNF, IL-1β, IL-6) and anti-inflammatory (IL-4, IL-10) cytokines in the L4-L5 spinal cord segments in relation to behavioral signs of neuropathic pain after unilateral sterile chronic constriction injury (sCCI) of the sciatic nerve. Withdrawal thresholds for mechanical hypersensitivity and latencies for thermal hypersensitivity were measured in hind paws 1 day before operation; 1, 3, and 7 days after sCCI operation; and then 5 and 24 h after intrathecal application of artificial cerebrospinal fluid or CD200Fc. RESULTS: Seven days from sCCI operation and 5 h from intrathecal application, CD200Fc reduced mechanical and thermal hypersensitivity when compared with control animals. Simultaneously, CD200Fc attenuated activation of glial cells and decreased proinflammatory and increased anti-inflammatory cytokine messenger RNA (mRNA) levels. Administration of CD200Fc also diminished elevation of CD200 and CD200R proteins as a concomitant reaction of the modulatory system to increased neuroinflammatory reactions after nerve injury. The anti-inflammatory effect of CD200Fc dropped at 24 h after intrathecal application. CONCLUSIONS: Intrathecal administration of the CD200R1 agonist CD200Fc induces very rapid suppression of neuroinflammatory reactions associated with glial activation and neuropathic pain development. This may constitute a promising and novel therapeutic approach for the treatment of neuropathic pain.
- MeSH
- antigeny povrchové farmakologie terapeutické užití MeSH
- časové faktory MeSH
- CD antigeny metabolismus MeSH
- cytokiny genetika metabolismus MeSH
- fyzikální stimulace škodlivé účinky MeSH
- gliový fibrilární kyselý protein metabolismus MeSH
- hyperalgezie farmakoterapie etiologie MeSH
- ischialgie komplikace farmakoterapie MeSH
- krysa rodu Rattus MeSH
- mícha účinky léků metabolismus MeSH
- modely nemocí na zvířatech MeSH
- neuroglie účinky léků metabolismus MeSH
- orexinové receptory MeSH
- potkani Wistar MeSH
- práh bolesti účinky léků MeSH
- receptory buněčného povrchu antagonisté a inhibitory terapeutické užití MeSH
- regulace genové exprese účinky léků MeSH
- spinální injekce MeSH
- zánět farmakoterapie etiologie metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- antigens, CD200 MeSH Prohlížeč
- antigeny povrchové MeSH
- CD antigeny MeSH
- CD200R1 protein, human MeSH Prohlížeč
- cytokiny MeSH
- gliový fibrilární kyselý protein MeSH
- orexinové receptory MeSH
- receptory buněčného povrchu MeSH