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M Kiessling

Publications and source records attributed to M Kiessling.

At least 55 records · Page 3Linked to original sources
PubMed1994

Amplification and differential expression of members of the erbB-gene family in human glioblastoma.

The objective of the present study was to determine the frequency of amplifications of three different members of the erbB gene family in human glioblastoma multiforme (GBM). We investigated 47 glial tumors (37 GBM WHO grade IV, 5 anaplastic astrocytomas WHO III and 5 astrocytomas WHO II) by Southern and Western analysis, and immunocytochemistry. Gene amplification of erbB genes in human malignant gliomas was restricted to the EGF receptor (EGFR) gene, erbB-1. We found amplification of the EGFR gene in 49% (18/37) of GBM but not in the astrocytomas WHO II/III. The erbB-2 and erbB-3 genes showed no amplification in the tumor specimens investigated in this study. At the protein level we found overexpression of the EGF receptor in 86% (32/37) by Western analysis and in 92% (34/37) by immunocytochemistry. Expression of the ERBB2 protein was present in 54% (20/37) but immunoreactivity was much weaker than for EGF receptor and in most cases barely detectable by Western analysis and immunocytochemistry. The ERBB3 protein was not expressed in the glial tumors investigated in this study. Of the three erbB genes only gene amplification and overexpression of the EGF receptor seems to have an impact on tumor progression of human gliomas. Our data from immunohistochemistry indicate that ERBB2 expression in GBM is closely correlated with EGF receptor levels and is therefore not useful as an independent prognostic parameter.

Adult↗
PubMed1994

Concurrent immediate early gene induction by epileptic seizures in heterotopic cortical grafts and neocortex.

Cortical primordia of rat fetuses (gestation day 14) were stereotactically grafted into the rostral striatum of adult recipient rats. After 8 weeks, the transplants had developed into a highly differentiated population of mature neuroectodermal cells. Host rats were then subjected to 15 min of bicuculline-induced epileptic seizures or served as controls. Seizure-elicited immediate early gene (IEG) expression was investigated after various postictal survival times (up to 24 h), using immunocytochemistry with specific antisera against seven IEG encoded proteins (c-FOS, FOS B, c-JUN, JUN B, JUN D, KROX-24, KROX-20). Constitutive IEG expression in intra striatum grafted neocortical neurons was identical to that in the corresponding host neocortex. In particular, abundant KROX-24 and lack of c-JUN expression implies the establishment of synaptic contacts within the graft or with the host circuitry. Postictal expression kinetics of individual IEG encoded proteins within the transplants were strikingly similar to those seen in the neocortex in situ. c-FOS and KROX-24 were most rapidly induced, followed by c-JUN and JUN B, and a more delayed induction of FOS B, JUN D and KROX-20. Apart from a slightly prolonged c-FOS expression in grafts, individual transcription factors remained elevated for different time periods and showed a concurrent decline in transplants and in neocortex in situ. In conclusion, IEG induction in grafts closely paralleled that in the host neocortex but differed from the adjacent striatum which exhibited no c-JUN induction at any time point investigated. These results indicate that following an appropriate differentiation period, heterotopically grafted embryonic cortical neurons respond to extracellular stimuli with changes of gene expression that closely resemble the normal host cortex. This suggests development of a similar molecular phenotype, including proper acquisition and intracellular processing of information.

Animals↗
PubMed1994

High induction threshold for transcription factor KROX-20 in the rat brain: partial co-expression with heat shock protein 70 following limbic seizures.

The transcription factor KROX-20, unlike many other immediate early genes, is not expressed in the rat hippocampus after bicuculline induced generalized seizures. Since limbic seizures are a more injurious stimulus, the KROX-20 expression profile was investigated in adult rats subjected to kainic acid induced limbic epilepsy at postictal intervals up to 48 h. Immunocytochemistry was performed using a specific polyclonal antiserum. In the hippocampus a sequential induction was observed with peak levels attained in dentate gyrus at 3 h, in CA1 at 8 h and in CA3 between 8 and 24 h, respectively. In contrast, no KROX-20 induction was found in hilus neurons. Prominent neuronal KROX-20 induction was also detected in other areas of the limbic system, in particular in amygdala and piriform cortex, as well as non-limbic regions such as neocortex and striatum. As is the case with KROX-20, heat shock protein (HSP) 70, a reliable marker for reversible neuronal injury, has a high induction threshold. Though not inducible in the hippocampus by generalized seizures, it is expressed after limbic epilepsy. Therefore, co-expression of KROX-20 and HSP70 was studied by a double labeling technique using a monoclonal antibody directed against the inducible form of HSP70. Neuronal subpopulations with perfect co-expression such as hippocampal CA1 neurons contrasted with others demonstrating partial co-induction (cortical neurons) or lack of co-expression (hilus cells), indicating that different stimuli trigger the activation of these two inducible genes.

Animals↗
PubMed1994

Stimulus-transcription coupling in focal cerebral ischemia.

Glutamate-mediated spreading depression is currently thought to be a key event in the pathogenesis of potential neuronal degeneration in the ischemic 'penumbra'. Glutamate receptor stimulation causes induction of transcription factors that belong to the class of immediate early genes (IEGs), thought to be involved in coupling neuronal excitation to target gene expression. Focal cerebral ischemia elicits a homogeneous expression of several IEGs, prominently in cortex. In the ischemic core, discrepancies are observed between mRNA and protein levels, due to a severe, persistent protein synthesis deficit, preventing the translation of IEG encoded mRNAs. Outside the ischemic core, widespread IEG expression occurs in the entire ipsilateral cortex at mRNA as well as at protein level. This homogeneous expression of transcription factors can be pinpointed to at least two different pathogenetic mechanisms by means of appropriate pharmacological antagonists. Prolonged IEG induction in the 'penumbra', an area in which neurons are metabolically compromised but not yet energy-depleted, cannot be suppressed by the administration of N-methyl-D-aspartate (NMDA) receptor antagonists. In contrast, short-lasting IEG induction in undamaged neurons remote from the ischemic territory, though also caused by ischemia-elicited spreading depression, can be blocked by NMDA receptor antagonists. In both areas, IEG expression identifies neurons destined to survive but is likely to be mediated by different signal transduction pathways, at the receptor, second messenger and/or the DNA level.

Animals↗
PubMed1994

[Detection of amplified DNA sequences by comparative genomic in situ hybridization with human glioma tumor DNA as probe].

Comparative genomic hybridization (CGH) provides a new possibility for the investigation of genetic alterations in tumour genomes. In our experiments CGH was carried out using genomic DNA from human glioblastoma multiforme (GBM) as a probe for chromosomal in situ suppression hybridization. Amplified DNA sequences contained in the tumour DNA showed specific signals, revealing the chromosomal positions of these sequences. Using this approach we detected amplifications of different chromosomal segments in individual GBM specimens. In accordance with the results from Southern analysis demonstrating amplification of the EGFR gene in 45% of human GBM, CGH signals in different GBM mapped to the region of this gene on chromosome 7p. Other signals detected by CGH involved chromosome 12q and 8q. Our data demonstrate CGH as a novel comprehensive and rapid approach for the analysis of complex genomic alterations in glial tumours.

Base Sequence↗
PubMed1993

Regionally selective stimulation of mitogen activated protein (MAP) kinase tyrosine phosphorylation after generalized seizures in the rat brain.

Immunoblot analysis using a phosphotyrosine-specific antibody was performed to investigate tyrosine phosphorylation of the mitogen activated protein (MAP) kinase in the rat brain. Epileptic seizures induced by systemic injection of bicuculline caused a rapid and transient stimulation of MAP kinase tyrosine phosphorylation in hippocampus and somatosensory cortex. This increase in tyrosine phosphorylation was markedly attenuated by the N-methyl-D-aspartate (NMDA) receptor antagonist MK-801. In contrast, in the cerebellum, tyrosine phosphorylation of MAP kinase remained undetectable after bicuculline-induced seizures. These results demonstrate that generalized seizures stimulate tyrosine phosphorylation of MAP kinase in a regionally selective manner.

Animals↗
PubMed1993

JUN, FOS, KROX, and CREB transcription factor proteins in the rat cortex: basal expression and induction by spreading depression and epileptic seizures.

The expression of the nuclear c-JUN, JUN B, JUN D, c-FOS, FOS B, KROX-24, and CREB transcription factors was investigated in the cortex of adult rats by immunocytochemistry. The expression patterns were studied in untreated rats and up to 24 hours following topical application of 1 M KCl to the cortical surface (KCl) or i.v. injection of bicuculline (BIC). Topical KCl induced cortical spreading depression and systemic injection of bicuculline evoked generalized tonic-clonic seizures. In untreated rats, JUN B, c-FOS, and FOS B were expressed in a small number of neurons in the piriform, perirhinal, entorhinal, and insular cortex and in layers II, III, and VI of all neocortical areas. In contrast, c-JUN, JUN D, and KROX-24 were expressed in all cortical layers but with different intensities of immunoreactivity (IR): c-JUN-IR was generally weak and predominantly present in layers II, III, and VI. JUN D-IR was equally strong in all layers. KROX-24 showed a prominent expression in layers II, IV, and VI. The CREB protein exhibited a slight preponderance in layer II and piriform cortex. Following KCl or BIC, a strong induction was seen for c-FOS, JUN B, and KROX-24, whereas c-JUN, JUN D, and FOS B showed only a moderate increase compared to basal levels. Changes of CREB-IR could not be detected. The localization of induced JUN, FOS, and KROX proteins reflected the pattern of labelling in untreated animals but demonstrated a higher intensity of labelling and an increased number of immunoreactive nuclei. The intensity and persistence of IR as well as the number of labelled cells following BIC exceeded those following KCl. Following BIC, increased levels of FOS B and JUN D were still present after 24 hours. Counterstaining with cresyl-violet and GFAP, a marker for astrocytes, revealed that JUN, FOS, and KROX proteins were expressed in neurons but not in glial cell populations. The present data demonstrate that CREB, JUN, FOS, and KROX transcription factors exhibit a layer-specific expression in the cerebral cortex with only slight area-specific differences both in untreated rats and following stimulation with KCl and BIC. The expression of transcription factor proteins indicate complex molecular genetic changes in cortical neurons due to pathophysiological events such as seizure activity and spreading depression.

Activating Transcription Factor 1↗
PubMed1993

Spatiotemporal induction of immediate early genes in the rat brain after limbic seizures: effects of NMDA receptor antagonist MK-801.

Fos, jun and krox belong to multigene families coding for transcription factors. These cellular immediate early genes (IEGs) are thought to be involved in coupling neuronal excitation to changes of target gene expression. Immunocytochemistry with specific antisera was used to assess regional levels of six IEG-encoded proteins (c-Fos, Fos B, Krox-24, c-Jun, Jun B, Jun D) in the rat forebrain after kainic acid-induced limbic seizures. The results demonstrate a complex spatial pattern of IEG induction and/or suppression in limbic and non-limbic structures. The sequence of induction within hippocampal subpopulations was identical for all IEGs investigated, following the order dentate gyrus, CA1 and CA3, and irrespective of different temporal profiles for individual transcription factors. Since Fos and Jun proteins act via homo- and heterodimer complexes at specific DNA sites, our data imply that the postictal combinatorial changes of these dimers allow a sequential and differential regulation of target gene expression in specific forebrain regions. Pretreatment with the non-competitive NMDA receptor antagonist MK-801 did not affect kainate-induced expression of IEGs in the limbic system, indicating that IEG induction in these regions is mediated by high-affinity kainate and AMPA receptors rather than NMDA receptors. In contrast, MK-801 abolished IEG induction in the somatosensory cortex and striatum, suggesting that IEG expression in non-limbic neurons occurs transsynaptically and is mediated by NMDA receptors.

Animals↗
PubMed1993

Expression of the c-erbB-2-encoded oncoprotein and progesterone receptor in human meningiomas.

The present study investigated the expression of c-erbB-2 in 59 meningiomas, including different histological subtypes and anaplastic variants, by immunocytochemistry and molecular biological techniques. Immunohistochemistry using the monoclonal antibody FWP-51 directed against c-erbB-2-encoded oncoprotein gp185 demonstrated variable degrees of immunoreactivity in all meningiomas. The intensity of immunostaining correlated with the degree of expression as assessed by Western analysis in 28 meningiomas using polyclonal antiserum 21N. There was no correlation between the degree of expression and histological variants. Immunoreactivity of all meningiomas was distinctly less intense, however, than that of the human breast cancer cell line SK-BR-3, and slightly lower than that of brain metastases of breast and ovarian carcinomas that served as positive controls for both methods. By Southern analysis all meningiomas showed a single copy of the c-erbB-2 gene. Non-neoplastic arachnoid cap cells also exhibited c-erbB-2 expression and the degree of immunoreactivity was comparable with the majority of meningiomas. These data argue against an overexpression of c-erbB-2 in meningiomas, but rather indicate a cell-type-specific constitutive expression of the c-erbB-2 gene product in meningiomas and their putative progenitor cells. Since a subgroup of meningiomas is known to express progesterone receptors (PR), gp185 immunoreactivity was compared to the hormone receptor status using monoclonal antibody KD68. Fifty-six percent meningiomas showed PR immunoreactivity, but there was no statistically significant correlation with the degree of gp185 expression.

Adult↗
PubMed1993

Stress-related psychophysiological reactions of truck drivers in relation to anxiety, defense, and situational factors.

A system analytic frame of reference is chosen for analysing interindividual differences in driving a technically optimised tank-lorry in comparison to a standard tank-lorry. Seven professional tank-lorry drivers were tested with psychological tests, and their test results were related to physiological measures assessed under different driving conditions in both lorry types. Two dimensions were used to explain the pattern of interactions between the independent (psychological and situational) and dependent (physiological) variables. It is argued that beyond technical improvements, also taking into account information on personality variables and situational factors is a promising approach to accident prevention research.

Adult↗
PubMed1993

The KROX-20 transcription factor in the rat central and peripheral nervous systems: novel expression pattern of an immediate early gene-encoded protein.

The KROX-20 protein (also termed EGR-2) is encoded by an immediate early gene cloned by cross-hybridization to the Drosophila melanogaster Krüppel gene. It belongs to a class of transcription factors with zinc finger motifs and binding activity to a transcriptional regulatory DNA element termed the early growth response consensus sequence. In the present study the temporospatial expression of KROX-20 was investigated in the central and peripheral nervous systems of normal rats and after various stimuli known to induce immediate early genes, including epileptic seizures, axotomy, pharmacological treatment with glutamate and alpha-adrenergic receptor antagonists, and peripheral noxious stimulation. Immunocytochemistry was performed with a specific polyclonal antiserum generated against a fusion protein containing KROX-20 sequences. In the central nervous system, KROX-20 protein demonstrated distinct constitutive nuclear expression in specific neuronal subpopulations of the cortex, septum, amygdala, olfactory bulb and hypothalamus. In addition, distinct cytoplasmic immunoreactivity was present in spinal and medullary motoneurons, dorsal root ganglion neurons and a few neuronal cell populations of midbrain and forebrain. In the CNS, KROX-20 was only induced by bicuculline-induced epileptic seizures. Topographically, the postictal increase of KROX-20 levels was restricted to areas with constitutive expression, such as cerebral cortex, fornix and amygdala. Induction of KROX-20 peaked at 4-8 h after onset of seizure activity. No increase in immunoreactivity was observed in the hippocampus, the brain region most severely affected by bicuculline-induced seizures. Transection of central and peripheral nerve fibers did not result in KROX-20 induction in axotomized neurons. However, KROX-20 was induced in Schwann-like cells after transection of the sciatic nerve. In contrast to KROX-20, KROX-24, a related transcription factor of the zinc finger family, was markedly induced in hippocampal and spinal neurons following seizures and peripheral noxious stimulation, respectively, as well as in CNS neurons following axotomy. Our data indicate that KROX-20 represents an immediately early gene product with basal expression in selected neuronal populations of the nervous system and a restricted inducibility after intentional stimuli.

Animals↗
PubMed1993

Induction and suppression of immediate early genes in specific rat brain regions by the non-competitive N-methyl-D-aspartate receptor antagonist MK-801.

The expression pattern of six different immediate early gene-encoded proteins was examined in the rat forebrain after intraperitoneal administration of MK-801, a non-competitive N-methyl-D-aspartate receptor antagonist, at doses of 3 mg/kg and 0.3 mg/kg, respectively. Following MK-801 treatment, the presence of c-FOS, FOS B, KROX-24, c-JUN, JUN B, and JUN D were investigated by immunocytochemistry with specific antisera at different time intervals up to 48 h. Selective induction of all six immediate early genes was found in layer III neurons of the posterior cingulate and retrosplenial cortex. More complex effects were observed in the neocortex: MK-801 did not influence constitutive expression of different FOS and JUN proteins, but caused marked induction of c-FOS, FOS B, JUN B and JUN D, mainly in layer IV, but also in layers V and VI. In contrast, strong neocortical constitutive expression of KROX-24 was almost abolished by MK-801 administration, and replaced by an expression pattern similar to that of FOS and JUN proteins. Subcortical areas such as the hypothalamus and thalamus demonstrated an induction of a subset of immediate early genes (c-fos, fos B, Krox-24, jun B). Injection of MK-801 caused the same distributional pattern of immediate early gene expression irrespective of the dose given, but the extent of changes was stronger after 3 mg/kg, and altered levels of immunoreactivity persisted longer. In many experimental paradigms, immediate early genes are induced by N-methyl-D-aspartate receptor-mediated mechanisms. This induction can readily be blocked by N-methyl-D-aspartate receptor antagonists like MK-801. Our data, however, indicate that MK-801 itself causes immediate early gene expression in specific neuronal populations. In the present study MK-801-elicited expression of immediate early gene-encoded proteins seems to identify reversibly injured neurons, mainly in layer III of the posterior cingulate and retrosplenial cortex. These neurons have previously been shown to be the principal target of N-methyl-D-aspartate receptor antagonist toxicity. Since immediate early gene induction precedes heat-shock protein expression as well as pathomorphological changes, and is induced in additional cortical cell populations, it seems to be a more rapid and more sensitive indicator of non-lethal neuronal injury.

Animals↗
PubMed1993

Differential transcription and translation of immediate early genes in the gerbil hippocampus after transient global ischemia.

Excitotoxic activation of glutamate receptors is thought to be a key event for the molecular pathogenesis of postischemic delayed neuronal death of CA-1 neurons in the gerbil hippocampus. Glutamate receptor stimulation also causes induction of transcription factors that belong to the class of immediate early genes. We examined the expression of six different immediate early genes in the gerbil hippocampus after transient global ischemia. Comparative analysis of c-fos and Krox-24 expression was carried out in the same animals at the transcriptional and translational level by in situ hybridization and immunocytochemistry. Postischemic synthesis of four additional immediate early gene (IEG)-encoded proteins (FOS-B, c-JUN, JUN-B, and JUN-D) was investigated by immunocytochemistry at recirculation intervals between 1 and 48 h. After 5 min of ischemia, transcription of c-fos and Krox-24 mRNA was induced in all hippocampal subpopulations with peak expression at 1 h after recirculation. In vulnerable CA-1 neurons, increased transcription of c-fos and Krox-24 was not followed by translation into protein. Induction of immediate early gene-encoded proteins was restricted to neuronal populations less vulnerable to brief ischemia and identified neurons that are targets of glutamate receptor-mediated neurotoxicity but that are destined to survive. Our data indicate an asynchronous synthesis and persistence of individual IEG-encoded proteins in these neurons. The staggered induction implies that combinatorial changes of transcription factors allow a differential postischemic regulation of target gene expression both spatially and over time.

Animals↗
PubMed1993

NMDA and glycine receptor mRNA expression following transient global ischemia in the gerbil brain.

Excitotoxic activation of postsynaptic N-methyl-D-aspartate (NMDA) receptors is thought to be a key event for the molecular pathogenesis of postischemic delayed neuronal death in CA1 hippocampus. To assess a possible interference of ischemia with NMDA receptor expression, transcription of the NMDA receptor 1 (NMDA-R1) gene was examined by in situ hybridization in the gerbil brain after 5 min of global ischemia and various recirculation intervals. In normal gerbil brain, NMDA-R1 was strongly expressed and equally abundant in CA1 and CA3 neurons. After ischemia, expression remained unchanged for 24 h, followed by a selective decline in mRNA levels in CA1 neurons, resulting in the complete disappearance of hybridization signals after 4 days. NMDA-R1 expression in forebrain neurons less vulnerable or resistant to ischemia including CA3 and dentate granule cells remained unchanged. Similar in situ data were obtained for the beta subunit of the inhibitory glycine receptor (Gly-R). This subunit is also abundantly expressed in the pyramidal cell layer of the hippocampus, but not known to be involved in the mechanisms of post-ischemic excitotoxicity.

Animals↗
PubMed1993

Immediate early gene expression in experimental epilepsy.

Neuronal excitation by experimentally induced seizures elicits the rapid induction of a set of genes called immediate early genes (IEGs). The gene products of fos, jun and Krox, multimember gene families that belong to the class of IEGs, participate in a fundamental biological control mechanism, the regulation of gene transcription. IEG encoded proteins act as third messengers in an intracellular signal transduction cascade between neural cell surface receptors, cytoplasmic second messenger systems and specific target genes in the nucleus, a process for which the term 'stimulus transcription coupling' has been given. Almost all types of seizures cause dynamic alterations of IEG expression in neurons of the limbic system, but also in non-limbic areas, such as the cortex, striatum and thalamus. IEG encoded transcription factors are thought to up- or down-regulate effector genes with preferential expression in the central nervous system, including genes for neurotransmitters, growth factors, receptors, synaptic and axonal proteins. If the concept holds true that IEGs act as molecular switches converting epileptic short-term excitation of neurons into alterations of the molecular phenotype, future research may help to explain hitherto unexplained phenomena in epileptogenesis including changes of synaptic efficacy, kindling and sprouting.

Animals↗
PubMed1993

Detection of human cytomegalovirus DNA in paraffin sections of human brain by polymerase chain reaction and the occurrence of false negative results.

Paraffin-embedded necropsy material from 6 patients with human cytomegalovirus encephalitis (HCMVE) corroborated by immunocytochemistry and 11 control cases were examined for the presence of human cytomegalovirus (HCMV) DNA by a nested polymerase chain reaction (nPCR). A characteristic 183 base pair (bp) fragment of the HCMV genome could readily be amplified in 4 cases of HCMVE. In 2 cases of HCMVE, viral DNA could be demonstrated only sporadically by PCR, due most likely to inefficient DNA extraction or DNA degradation. All control cases remained negative. The nPCR provides a specific method for detecting HCMV DNA in routinely processed biopsy and necropsy material and may be used in archival tissues for the diagnosis of infection. Fixation of samples and DNA extraction are, however, crucial steps and require careful control if PCR is used for detection of HCMV, to avoid false negative results.

Adult↗
PubMed1992

Induction of FOS and JUN proteins after focal ischemia in the rat: differential effect of the N-methyl-D-aspartate receptor antagonist MK-801.

FOS and JUN proteins are transcription factors thought to be involved in coupling neuronal excitation to target gene expression. Cortical infarction of consistent size and location was produced by irradiating the rat brain with Xenon light through the intact skull for 20 min following systemic injection of the photo-sensitizing dye, rose bengal. To investigate the time course and distribution pattern of five cellular immediate early gene (IEG)-encoded proteins after focal ischemia, the expression of c-FOS, FOS B, c-JUN, JUN B and JUN D was studied immunocytochemically in sham-operated control animals and at different postischemic time intervals up to 24 h. A separate group of animals was pretreated with the non-competitive N-methyl-D-aspartate (NMDA) antagonist MK-801. Photochemically induced focal ischemia caused a rapid induction of FOS and JUN proteins in the entire ipsilateral cortex apart from the ischemic focus. Immunoreactivity in the ipsilateral subcortical gray and white matter and in the entire contralateral hemisphere was indistinguishable from control animals. Individual IEG-encoded proteins were sequentially induced with increased levels of immunoreactivity persisting for different time periods up to 24 h. c-FOS, FOS B, c-JUN and JUN B exhibited a characteristic distribution pattern as reflected by different staining intensities in individual cortical layers. The rapid IEG induction in the entire ipsilateral sensorimotor and limbic structure-associated cortices after photochemically induced infarction most likely reflects spreading depression caused by ischemia and mediated by NMDA receptors.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗