198 results on '"Giehl K"'
Search Results
2. Secreted ProNGF Is a Pathophysiological Death-Inducing Ligand after Adult CNS Injury
- Author
-
Harrington, A. W., Leiner, B., Blechschmitt, C., Arevalo, J. C., Lee, R., Mörl, K., Meyer, M., Hempstead, B. L., Yoon, S. O., Giehl, K. M., and Thoenen, Hans
- Published
- 2004
3. A retrospective study on the liver toxicity of oral retinoids in Chanarin–Dorfman syndrome.
- Author
-
Valette, C., Jonca, N., Fischer, J., Pernin‐Grandjean, J., Granier Tournier, C., Diociaiuti, A., Neri, I., Dreyfus, I., Furman, M., Giehl, K., Wollenberg, A., Mallet, S., Martin, L., Martin‐Santiago, A., Onnis, G., Broue, P., Leclerc‐Mercier, S., Schmuth, M., Sprecher, E., and Gruber, R.
- Subjects
HEPATOTOXICOLOGY ,ICHTHYOSIS ,RETINOIDS ,LIPIDOSES ,HEPATIC fibrosis - Abstract
Patient (F5-1) had a cirrhosis at the age of 34 years (after 12 years of OR), but liver blood parameters remained stable during the 31 years of follow-up. Before introducing OR, all also had liver anomalies, that consisted in either increased liver enzymes, hyper echogenic liver, hepatosplenomaly or cirrhosis for one patient (F6-1). In conclusion, awaiting future targeted therapy for DCS or prospective monitoring studies, there is no safety signal to contraindicate OR in CDS patients with disabling skin anomalies, on condition that a close monitoring is performed. [Extracted from the article]
- Published
- 2023
- Full Text
- View/download PDF
4. Chanarin–Dorfman syndrome with rare renal involvement
- Author
-
Verma, S.B., Mittal, A., Wollina, U., Eckstein, G.H., Gohel, K., and Giehl, K.
- Published
- 2017
- Full Text
- View/download PDF
5. Non-invasive diagnosis of sweat gland dysplasia using optical coherence tomography and reflectance confocal microscopy in a family with anhidrotic ectodermal dysplasia (Christ–Siemens–Touraine syndrome)
- Author
-
Reinholz, M., Gauglitz, G. G., Giehl, K., Braun-Falco, M., Schwaiger, H., Schauber, J., Ruzicka, T., Berneburg, M., and von Braunmühl, T.
- Published
- 2016
- Full Text
- View/download PDF
6. Oncogenic Ras proteins in tumor cell migration and invasion
- Author
-
Giehl, K.
- Published
- 2015
7. The oestrogen receptor 2 (ESR2) gene in female-pattern hair loss: replication of association with rs10137185 in German patients
- Author
-
Redler, S., Birch, P., Drichel, D., Hofmann, P., Dobson, K., Böhmer, A. C., Becker, J., Giehl, K. A., Tazi-Ahnini, R., Kruse, R., Wolff, H., Miesel, A., Fischer, T., Böhm, M., Nuwayhid, R., Garcia Bartels, N., Lutz, G., Becker, T., Blume-Peytavi, U., Nöthen, M. M., Messenger, A. G., and Betz, R. C.
- Published
- 2014
- Full Text
- View/download PDF
8. Signalling processes involved in C-peptide-induced chemotaxis of CD4-positive lymphocytes
- Author
-
Aleksic, M., Walcher, D., Giehl, K., Bach, H., Grüb, M., Durst, R., Hombach, V., and Marx, N.
- Published
- 2009
- Full Text
- View/download PDF
9. CUTL1 promotes tumor cell migration by decreasing proteasome-mediated Src degradation
- Author
-
Aleksic, T, Bechtel, M, Krndija, D, von Wichert, G, Knobel, B, Giehl, K, Gress, T M, and Michl, P
- Published
- 2007
- Full Text
- View/download PDF
10. The Rho guanine nucleotide exchange factor Trio is required for neural crest cell migration and interacts with Dishevelled
- Author
-
Kratzer, M.C., Becker, S.F.S., Grund, A., Merks, A., Harnoš, J., Bryja, V., Giehl, K., Kashef, J., and Borchers, A.
- Subjects
Cardiovascular and Metabolic Diseases - Abstract
Directional migration during embryogenesis and tumor progression faces the challenge that numerous external signals need to converge to precisely control cell movement. The Rho guanine exchange factor (GEF) Trio is especially well suited to relay signals as it features distinct catalytic domains to activate Rho GTPases. Here we show that Trio is required for Xenopus cranial neural crest (NC) cell migration and cartilage formation. Trio cell-autonomously controls protrusion formation of NC cells and Trio morphant NC cells show a blebbing phenotype. Interestingly, the Trio GEF2 domain is sufficient to rescue protrusion formation and migration of Trio morphant NC cells. We show that this domain interacts with the DEP/C-terminus of Dishevelled (DVL). DVL - but not a deletion construct lacking the DEP domain – is able to rescue protrusion formation and migration of Trio morphant NC cells. This is likely mediated by activation of Rac1, as we find that DVL rescues Rac1 activity in Trio morphant embryos. Thus, our data provide evidence for a novel signaling pathway, whereby Trio controls protrusion formation of cranial NC cells by interacting with DVL to activate Rac1.
- Published
- 2020
11. 1237 Mosaic PRKCA fusions cause a novel congenital melanocytoma syndrome associated with uveal melanoma
- Author
-
Polubothu, S., Martin, S. Barberan, Bruzos, A., Calonje, E., Sagoo, M., Spence, G., Giehl, K., and Kinsler, V.
- Published
- 2023
- Full Text
- View/download PDF
12. TGFβ1 represses proliferation of pancreatic carcinoma cells which correlates with Smad4-independent inhibition of ERK activation
- Author
-
Giehl, K, Seidel, B, Gierschik, P, Adler, G, and Menke, A
- Published
- 2000
- Full Text
- View/download PDF
13. Investigation of selected cytokine genes suggests that IL2RA and the TNF/LTA locus are risk factors for severe alopecia areata
- Author
-
Redler, S., Albert, F., Brockschmidt, F. F., Herold, C., Hanneken, S., Eigelshoven, S., Giehl, K. A., Kruse, R., Lutz, G., Wolff, H., Blaumeiser, B., Böhm, M., Becker, T., Nöthen, M. M., and Betz, R. C.
- Published
- 2012
- Full Text
- View/download PDF
14. Investigation of the male pattern baldness major genetic susceptibility loci AR/EDA2R and 20p11 in female pattern hair loss
- Author
-
Redler, S., Brockschmidt, F. F., Tazi-Ahnini, R., Drichel, D., Birch, M. P., Dobson, K., Giehl, K. A., Herms, S., Refke, M., Kluck, N., Kruse, R., Lutz, G., Wolff, H., Böhm, M., Becker, T., Nöthen, M. M., Messenger, A. G., and Betz, R. C.
- Published
- 2012
- Full Text
- View/download PDF
15. Investigation of variants of the aromatase gene (CYP19A1) in female pattern hair loss
- Author
-
Redler, S., Birch, M. P., Drichel, D., Dobson, K., Brockschmidt, F. F., Tazi-Ahnini, R., Giehl, K. A., Kluck, N., Kruse, R., Lutz, G., Wolff, H., Becker, T., Nöthen, M. M., Messenger, A. G., and Betz, R. C.
- Published
- 2011
- Full Text
- View/download PDF
16. The TRAF1/C5 locus confers risk for familial and severe alopecia areata
- Author
-
Redler, S., Brockschmidt, F. F., Forstbauer, L., Giehl, K. A., Herold, C., Eigelshoven, S., Hanneken, S., De Weert, J., Lutz, G., Wolff, H., Kruse, R., Blaumeiser, B., Böhm, M., Becker, T., Nöthen, M. M., and Betz, R. C.
- Published
- 2010
- Full Text
- View/download PDF
17. Casus pro diagnosi: K24/02
- Author
-
Kunte, C, Tietze, J, and Giehl, K
- Published
- 2009
18. Hair interior defect in AKR/J mice
- Author
-
Giehl, K. A., Potter, C. S., Wu, B., Silva, K. A., Rowe, L. B., Awgulewitsch, A., and Sundberg, J. P.
- Published
- 2009
- Full Text
- View/download PDF
19. Pili annulati: refinement of the locus on chromosome 12q24.33 to a 2·9-Mb interval and candidate gene analysis
- Author
-
Giehl, K. A., Rogers, M. A., Radivojkov, M., Tosti, A., de Berker, D. A.R., Weinlich, G., Schmuth, M., Ruzicka, T., and Eckstein, G. N.
- Published
- 2009
- Full Text
- View/download PDF
20. Characterization and expression analysis of the hair keratin associated protein KAP26.1
- Author
-
Rogers, M. A., Langbein, L., Praetzel-Wunder, S., and Giehl, K.
- Published
- 2008
21. Identification and characterization of 20 immunocompetent patients with simultaneous varicella zoster and herpes simplex virus infection
- Author
-
Giehl, K A, Müller-Sander, E, Rottenkolber, M, Degitz, K, Volkenandt, M, and Berking, C
- Published
- 2008
22. Protein expression of melanocyte growth factors (bFGF, SCF) and their receptors (FGFR-1, c-kit) in nevi and melanoma
- Author
-
Giehl, K. A., Nägele, U., Volkenandt, M., and Berking, C.
- Published
- 2007
23. Cytokeratin expression in pili annulati hair follicles
- Author
-
Giehl, K. A., Dean, D., Dawber, R. P. R., Leigh, I., de Berker, D. A. R., and Wojnarowska, F.
- Published
- 2005
24. Update on detection, morphology and fragility in pili annulati in three kindreds
- Author
-
Giehl, K A, Ferguson, D JP, Dawber, R PR, Pittelkow, M R, Foehles, J, and de Berker, D AR
- Published
- 2004
25. Alterations in the basement membrane zone in pili annulati hair follicles as demonstrated by electron microscopy and immunohistochemistry
- Author
-
GIEHL, K. A., FERGUSON, D. J.P., DEAN, D., CHUANG, Y. H., ALLEN, J., DE. BERKER, D. A.R., TOSTI, A., DAWBER, R. P.R., and WOJNAROWSKA, F.
- Published
- 2004
26. Computational modelling reveals distinct patterns of cognitive and physical motivation in elite athletes
- Author
-
Chong, T, Apps, M, Giehl, K, Hall, S, Clifton, C, and Husain, M
- Subjects
Adult ,Male ,Motivation ,lcsh:R ,Decision Making ,Physical Exertion ,lcsh:Medicine ,Choice Behavior ,Article ,Young Adult ,Cognition ,Reward ,Athletes ,Humans ,lcsh:Q ,Computer Simulation ,Female ,lcsh:Science ,Physical Examination - Abstract
Effort can be perceived both cognitively and physically, but the computational mechanisms underlying the motivation to invest effort in each domain remain unclear. In particular, it is unknown whether intensive physical training is associated with higher motivation specific to that domain, or whether it is accompanied by corresponding changes in cognitive motivation. Here, we tested a group of elite Oxford University rowers, and compared their behaviour to matched non-athletic controls. We trained participants on two tasks involving cognitive or physical effort. They then decided between a baseline low level of effort for low reward, versus higher levels of effort for higher rewards. Separate choices were made for the cognitive and physical tasks, which allowed us to computationally model motivation in each domain independently. As expected, athletes were willing to exert greater amounts of physical effort than non-athletes. Critically, however, the nature of cognitive effort-based decisions was different between groups, with a concave pattern of effort discounting for athletes but a convex pattern for non-athletes. These data suggest that the greater physical drive in athletes is accompanied by fundamentally different patterns of cognitive effort discounting, and suggests a complex relationship between motivation in the two domains.
- Published
- 2018
27. Neurocomputational mechanisms underlying valuation of effort costs
- Author
-
Chong, TTJ, Apps, M, Giehl, K, Sillence, A, Grima, LL, and Husain, M
- Abstract
In everyday life, we have to decide whether it is worth exerting effort to obtain rewards. Effort can be experienced in different domains, with some tasks requiring significant cognitive demand, and others being more physically effortful. The motivation to exert effort for reward is highly subjective, and varies considerably across the different domains of behaviour. However, very little is known about the computational or neural basis of how different effort costs are subjectively weighed against rewards. Is there a common, domain-general system of brain areas that evaluates all costs and benefits? Here, we used computational modelling and functional magnetic resonance imaging (fMRI) to examine the mechanisms underlying value processing in both the cognitive and physical domains. Participants were trained on two novel tasks which parametrically varied either cognitive or physical effort. During fMRI, participants indicated their preferences between a fixed loweffort/ low-reward option and a variable higher-effort/higher-reward offer for each effort domain. Critically, reward devaluation by both cognitive and physical effort was subserved by a common network of areas including dorsomedial and dorsolateral prefrontal cortex, intraparietal sulcus and anterior insula. Activity within these domain-general areas also covaried negatively with reward and positively with effort, suggesting an integration of these parameters within these areas. Additionally, the amygdala appeared to play a unique, domain-specific role in processing the value of rewards associated with cognitive effort. These results are the first to reveal the neurocomputational mechanisms underlying subjective cost-benefit valuation across different domains of effort, and provide insight into the multidimensional nature of motivation.
- Published
- 2017
28. Signal transduction--receptors, mediators, and genes
- Author
-
Entschladen, F, Lindquist, JA, Serfling, E, Thiel, G, Kieser, A, Giehl, K, Ehrhardt, C, Feller, SM, Ullrich, O, Schaper, F, Janssen, O, Hass, R, and Friedrich, K
- Abstract
The 2008 annual meeting of the Signal Transduction Society covered a broad spectrum of topics, with signaling in immune cells as the special focus of the meeting. Many of the immune signaling talks concerned B and T lymphocytes in particular; the role of inflammatory cytokines in cancer progression was also addressed. Neoplastic development was also discussed with regard to aspects of cell cycle control, aging, and transformation. Topics extended to signaling pathways induced by bacteria, viruses, and environmental toxins, as well as those involved in differentiation, morphogenesis, and cell death. This international and interdisciplinary scientific gathering induced lively discussions and close interactions between participants.
- Published
- 2016
29. Visual short-term memory deficits in REM sleep behaviour disorder mirror those in Parkinson's disease
- Author
-
Rolinski, M, Zokaei, N, Baig, F, Giehl, K, Quinnell, T, Zaiwalla, Z, Mackay, C, Husain, M, and Hu, M
- Subjects
Male ,Memory Disorders ,Polysomnography ,Prodromal Symptoms ,Parkinson Disease ,REM Sleep Behavior Disorder ,Memory, Short-Term ,Case-Control Studies ,Mental Recall ,Visual Perception ,Humans ,Female ,Photic Stimulation ,Aged - Abstract
Individuals with REM sleep behaviour disorder are at significantly higher risk of developing Parkinson's disease. Here we examined visual short-term memory deficits--long associated with Parkinson's disease--in patients with REM sleep behaviour disorder without Parkinson's disease using a novel task that measures recall precision. Visual short-term memory for sequentially presented coloured bars of different orientation was assessed in 21 patients with polysomnography-proven idiopathic REM sleep behaviour disorder, 26 cases with early Parkinson's disease and 26 healthy controls. Three tasks using the same stimuli controlled for attentional filtering ability, sensorimotor and temporal decay factors. Both patients with REM sleep behaviour disorder and Parkinson's disease demonstrated a deficit in visual short-term memory, with recall precision significantly worse than in healthy controls with no deficit observed in any of the control tasks. Importantly, the pattern of memory deficit in both patient groups was specifically explained by an increase in random responses. These results demonstrate that it is possible to detect the signature of memory impairment associated with Parkinson's disease in individuals with REM sleep behaviour disorder, a condition associated with a high risk of developing Parkinson's disease. The pattern of visual short-term memory deficit potentially provides a cognitive marker of 'prodromal' Parkinson's disease that might be useful in tracking disease progression and for disease-modifying intervention trials.
- Published
- 2016
- Full Text
- View/download PDF
30. Burden of itch in ichthyosis: a multicentre study in 94 patients.
- Author
-
De Palma, A.M., Mazereeuw‐Hautier, J., Giehl, K., Hernández‐Martin, A., Merlos, M., Moons, P., and Morren, M.A.
- Subjects
ICHTHYOSIS ,ITCHING ,SURFACE area - Abstract
Background: From clinical experience, we know that itch is a major concern for many ichthyosis patients. Nonetheless, no previous studies specifically addressed the issue of itch in ichthyosis. Objective: The objective of this study was to specifically address the burden of itch and all its dimensions in ichthyosis patients. Methods: Ninety‐four ichthyosis patients from four different centres were recruited to participate in this cross‐sectional, questionnaire‐based study. All participants completed the Leuven Itch Scale, a multidimensional self‐report instrument that quantifies the frequency, duration, severity, distress, consequences and surface area of itch. Results: Participants included 18 keratinopathic types, 55 autosomal recessive congenital ichthyoses, 11 X‐linked recessive ichthyoses (XLRIs), 6 Netherton's ichthyoses, 1 Sjögren–Larsson type, 1 Iocrin ichthyosis and 2 unknown subtypes. Itch occurred in 93% of all patients. In patients with itch, 63% reported that it was often or always present, although most itch episodes were short in duration. Itch, in all its dimensions, was worst in patients with Netherton syndrome. Patients with XLRI had in general a lower itch profile. About half of all ichthyosis patients reported to experience flares during a change in weather, in a hot environment or in stressful situations, whereas a cold environment led to itch in only 26% of patients. The most significant consequences of itching were lesions from scratching, difficulties in falling asleep, bad mood and loss of concentration. Conclusions: Itch is a major concern in patients with ichthyosis, with significant impact on daily life. Research on future treatments should therefore take itch into consideration and itch should be evaluated in clinical studies. Among the studied subgroups, Netherton patients experienced the most severe consequences. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
31. Signal transduction--receptors, mediators, and genes
- Author
-
Entschladen, F, Lindquist, J A, Serfling, E, Thiel, G, Kieser, A, Weber, S A, Giehl, K, Ehrhardt, C, Feller, S M, Ullrich, O, Schaper, F, Janssen, O, Hass, R, Friedrich, K, University of Zurich, and Entschladen, F
- Subjects
1307 Cell Biology ,1303 Biochemistry ,10017 Institute of Anatomy ,1312 Molecular Biology ,570 Life sciences ,biology ,610 Medicine & health - Published
- 2009
32. TGFbeta1 represses proliferation of pancreatic carcinoma cells which correlates with Smad4-independent inhibition of ERK activation
- Author
-
Giehl, K., Seidel, B., Gierschik, P., Adler, G., Menke, A., and Publica
- Subjects
pancreatic cancer - Abstract
Transforming growth factor beta (TGFbeta) is a tumor suppressor acting as inhibitor of cell cycle progression of epithelial cells. We show that treatment of the pancreatic, carcinoma cell lines PANC-1 and BxPC-3 with TGFbeta1 inhibits both growth factor-induced activation of the extracellular signal-regulated kinase 2 (ERK2) and translocation of the kinase to the nucleus. TGFbeta1 causes a concentration-dependent reduction of cell proliferation in both cell lines. By measuring ERK activation, we can show that TGFbeta1 is able to repress ERK activation induced by mitogenic stimuli such as EGF. This inhibitory effect of TGFbeta1 is not mediated by suppression of Ras or c-Raf-1 activation, but mediated by TGFbeta1-induced activation of a serine-threonine phosphatase, as demonstrated by inhibition of phosphatases by treatment with okadaic acid. Results obtained in the Smad4-deficient pancreatic carcinoma cell line BxPC-3, demonstrate that TGFbeta1-induced growth inhibition is mediated by a Smad4-independent prevention of ERK2 activation. In contrast to the effects of TGFbeta1 on epithelial cells, mesenchymal NIH3T3 fibroblasts exhibit elevated ERK2 activation and increased cell proliferation in response to TGFbeta1 treatment. Smad4-independent phosphatase-mediated inhibition of mitogen-activated ERK2 represents a novel effector pathway contributing to suppression of epithelial pancreatic carcinoma cell proliferation by TGFbeta1, in addition to the well-known Smad-induced tumor suppressor activity of TGFbeta.
- Published
- 2000
33. Neuronal Development.
- Author
-
Giehl, K.
- Published
- 2007
- Full Text
- View/download PDF
34. Expression of MTA1 promotes motility and invasiveness of PANC-1 pancreatic carcinoma cells.
- Author
-
Hofer, M.D., Menke, A., Genze, F., Gierschik, P., and Giehl, K.
- Subjects
PANCREATIC cancer ,METASTASIS ,TUMORS ,CANCER ,ONCOLOGY - Abstract
The human metastasis-associated protein 1 (MTA1) is a constituent of the nucleosome-remodelling and -deacetylation complex. Its expression has been correlated with the invasion and metastasis of epithelial neoplasms. To address the functional consequences of MTA1 expression in pancreatic carcinoma cells, we have established PANC-1 pancreatic carcinoma cells that stably express MTA1 as an enhanced green fluorescent fusion protein (EGFP-MTA1). Here, we demonstrate that heterologous expression of EGFP-MTA1 markedly enhanced the cellular motility and the invasive penetration of epithelial barriers by the cells. Expression of EGFP-MTA1 had no effect on substrate-independent growth, but reduced substrate-dependent cell proliferation. In addition, the organisation of the cytokeratin filament system and the localisation of the actin cytoskeleton-associated protein IQGAP1 were distinctly altered in EGFP-MTA1-expressing cells. These results indicate that enhanced expression of MTA1 promotes the acquisition of an invasive, metastatic phenotype, and thus enhances the malignancy of pancreatic adenocarcinoma cells by modulation of the cytoskeleton. [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
35. TGFβ1 represses proliferation of pancreatic carcinoma cells which correlates with Smad4-independent inhibition of ERK activation.
- Author
-
Giehl, K, Seidel, B, Gierschik, P, Adler, G, and Menke, A
- Subjects
- *
PANCREATIC cancer , *CANCER cells , *EPITHELIAL cells - Abstract
Transforming growth factor beta (TGFβ) is a tumor suppressor acting as inhibitor of cell cycle progression of epithelial cells. We show that treatment of the pancreatic carcinoma cell lines PANC-1 and BxPC-3 with TGFβ1 inhibits both growth factor-induced activation of the extracellular signal-regulated kinase 2 (ERK2) and translocation of the kinase to the nucleus. TGFβ1 causes a concentration-dependent reduction of cell proliferation in both cell lines. By measuring ERK activation, we can show that TGFβ1 is able to repress ERK activation induced by mitogenic stimuli such as EGF. This inhibitory effect of TGFβ1 is not mediated by suppression of Ras or c-Raf-1 activation, but mediated by TGFβ1-induced activation of a serine-threonine phosphatase, as demonstrated by inhibition of phosphatases by treatment with okadaic acid. Results obtained in the Smad4-deficient pancreatic carcinoma cell line BxPC-3, demonstrate that TGFβ1-induced growth inhibition is mediated by a Smad4-independent prevention of ERK2 activation. In contrast to the effects of TGFβ1 on epithelial cells, mesenchymal NIH3T3 fibroblasts exhibit elevated ERK2 activation and increased cell proliferation in response to TGFβ1 treatment. Smad4-independent phosphatase-mediated inhibition of mitogen-activated ERK2 represents a novel effector pathway contributing to suppression of epithelial pancreatic carcinoma cell proliferation by TGFβ1, in addition to the well-known Smad-induced tumor suppressor activity of TGFβ. Oncogene (2000) 19, 4531–4541 [ABSTRACT FROM AUTHOR]
- Published
- 2000
- Full Text
- View/download PDF
36. Hepatocyte Growth Factor and Fibroblast Growth Factor 2 are Overexpressed After Cerulein-Induced Acute Pancreatitis.
- Author
-
Menke, A., Yamaguchi, H., Giehl, K., and Adler, G.
- Published
- 1999
- Full Text
- View/download PDF
37. Signal transduction, receptors, mediators and genes: younger than ever - the 13th meeting of the Signal Transduction Society focused on aging and immunology
- Author
-
Klotz Lars-Oliver, Kieser Arnd, Huber Otmar, Hermanns Heike, Giehl Klaudia, Behrmann Iris, Baumgrass Ria, Altschmied Joachim, Entschladen Frank, Kubatzky Katharina F, Hass Ralf, Janssen Ottmar, and Friedrich Karlheinz
- Subjects
Medicine ,Cytology ,QH573-671 - Abstract
Abstract The 13th meeting of the Signal Transduction Society was held in Weimar, from October 28 to 30, 2009. Special focus of the 2009 conference was "Aging and Senescence", which was co-organized by the SFB 728 "Environmentally-Induced Aging Processes" of the University of Düsseldorf and the study group 'Signal Transduction' of the German Society for Cell Biology (DGZ). In addition, several other areas of signal transduction research were covered and supported by different consortia associated with the Signal Transduction Society including the long-term associated study groups of the German Society for Immunology and the Society for Biochemistry and Molecular Biology, and for instance the SFB/Transregio 52 "Transcriptional Programming of Individual T Cell Subsets" located in Würzburg, Mainz and Berlin. The different research areas that were introduced by outstanding keynote speakers attracted more than 250 scientists, showing the timeliness and relevance of the interdisciplinary concept and exchange of knowledge during the three days of the scientific program. This report gives an overview of the presentations of the conference.
- Published
- 2010
- Full Text
- View/download PDF
38. Rac1 activation inhibits E-cadherin-mediated adherens junctions via binding to IQGAP1 in pancreatic carcinoma cells
- Author
-
Giehl Klaudia, Baum Iris, Meinel Katrin, Hage Beatrix, and Menke Andre
- Subjects
Medicine ,Cytology ,QH573-671 - Abstract
Abstract Background Monomeric GTPases of the Rho family control a variety of cellular functions including actin cytoskeleton organisation, cell migration and cell adhesion. Defects in these regulatory processes are involved in tumour progression and metastasis. The development of metastatic carcinoma is accompanied by deregulation of adherens junctions, which are composed of E-cadherin/β- and α-catenin complexes. Results Here, we show that the activity of the monomeric GTPase Rac1 contributes to inhibition of E-cadherin-mediated cell-cell adhesion in pancreatic carcinoma cells. Stable expression of constitutively active Rac1(V12) reduced the amount of E-cadherin on protein level in PANC-1 pancreatic carcinoma cells, whereas expression of dominant negative Rac1(N17) resulted in an increased amount of E-cadherin. Extraction of proteins associated with the actin cytoskeleton as well as coimmunoprecipitation analyses demonstrated markedly decreased amounts of E-cadherin/catenin complexes in Rac1(V12)-expressing cells, but increased amounts of functional E-cadherin/catenin complexes in cells expressing Rac1(N17). Cell aggregation and migration assays revealed, that cells containing less E-cadherin due to expression of Rac1(V12), exhibited reduced cell-cell adhesion and increased cell motility. The Rac/Cdc42 effector protein IQGAP1 has been implicated in regulating cell-cell adhesion. Coimmunoprecipitation studies showed a decrease in the association between IQGAP1 and β-catenin in Rac1(V12)-expressing PANC-1 cells and an association of IQGAP1 with Rac1(V12). Elevated association of IQGAP1 with the E-cadherin adhesion complex via β-catenin correlated with increased intercellular adhesion of PANC-1 cells. Conclusion These results indicate that active Rac1 destabilises E-cadherin-mediated cell-cell adhesion in pancreatic carcinoma cells by interacting with IQGAP1 which is associated with a disassembly of E-cadherin-mediated adherens junctions. Inhibition of Rac1 activity induced increased E-cadherin-mediated cellular adhesion.
- Published
- 2009
- Full Text
- View/download PDF
39. Signal Transduction in the Footsteps of Goethe and Schiller
- Author
-
Feller Stephan M, Ehrhardt Christina, Giehl Klaudia, Kieser Arnd, Thiel Gerald, Serfling Edgar, Entschladen Frank, Lindquist Jonathan A, Friedrich Karlheinz, Ullrich Oliver, Schaper Fred, Janssen Ottmar, and Hass Ralf
- Subjects
Medicine ,Cytology ,QH573-671 - Abstract
Abstract The historical town of Weimar in Thuringia, the "green heart of Germany" was the sphere of Goethe and Schiller, the two most famous representatives of German literature's classic era. Not yet entirely as influential as those two cultural icons, the Signal Transduction Society (STS) has nevertheless in the last decade established within the walls of Weimar an annual interdisciplinary Meeting on "Signal Transduction – Receptors, Mediators and Genes", which is well recognized as a most attractive opportunity to exchange results and ideas in the field. The 12th STS Meeting was held from October 28 to 31 and provided a state-of-the-art overview of various areas of signal transduction research in which progress is fast and discussion lively. This report is intended to share with the readers of CCS some highlights of the Meeting Workshops devoted to specific aspects of signal transduction.
- Published
- 2009
- Full Text
- View/download PDF
40. Specific effects of Lef-1 splice variants on the regulation of gene expression in pancreatic cancer cells.
- Author
-
Jesse, S., Giehl, K., König, A., and Menke, A.
- Subjects
- *
CANCER cells , *CELL migration , *CELL proliferation , *CELL growth , *CELL communication - Abstract
The lymphoid enhancer factor (Lef-1) belongs to the nuclear transducers of canonical Wnt-signalling in embryogenesis and cancer. Lef-1 acts, in cooperation with betacatenin, as a context-dependent transcriptional activator or repressor thereby influencing multiple cellular functions such as proliferation, differentiation and migration. Here we report an increased Lef-1 expression in human pancreatic cancer, which correlates with advanced tumour stages. As demonstrated by RT-PCR analysis, pancreatic carcinoma exhibit two different transcripts present in pancreatic carcinomas. One transcript was identified as the full length Lef-1 (Lef-1 FL), whereas the second, shorter transcript, lacked exon VI (Lef-1 exon VI) compared to the published sequence. Comparative analysis of these two Lef-1 variants revealed different cellular effects after transient expression in pancreatic carcinoma cells. Forced expression of Lef-1 exon VI in pancreatic carcinoma cells inhibited E-cadherin expression and resulted in reduced cellular aggregation and increased cell migration compared to cells expressing full length Lef-1. Expression of Lef-1 FL, but not the newly identified Lef-1 exon VI, induced expression of the cell cycle regulating proteins cmyc and cyclin D1 and resulted in enhanced cell proliferation. Thus, our findings implicate that expression of alternatively spliced isoforms of Lef-1 are involved in the determination of proliferative or migratory characteristics of pancreatic carcinoma cells. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
41. Cortical Tau Aggregation Patterns Associated With Apraxia in Patients With Alzheimer Disease.
- Author
-
Bischof GN, Jaeger E, Giehl K, Jessen F, Onur OA, O'Bryant S, Kara E, Weiss PH, and Drzezga A
- Subjects
- Humans, Female, Male, Aged, Cerebral Cortex diagnostic imaging, Cerebral Cortex metabolism, Cerebral Cortex pathology, Aged, 80 and over, Middle Aged, Carbolines, Alzheimer Disease metabolism, Alzheimer Disease diagnostic imaging, Alzheimer Disease complications, Apraxias diagnostic imaging, Apraxias metabolism, Apraxias etiology, tau Proteins metabolism, Positron-Emission Tomography
- Abstract
Background and Objectives: Apraxia is a frequently observed symptom in Alzheimer disease (AD), but the causal pathomechanism underlying this dysfunction is not well understood. Previous studies have demonstrated associations between various cognitive dysfunctions in AD and cortical tau deposition in specific brain areas, suggesting a causal relationship. Thus, we hypothesized that specific regional patterns of tau pathology in praxis-related brain regions may be associated with apraxic deficits in AD. For this purpose, we performed PET imaging with the second-generation tau-PET tracer [18F]PI-2620 in a well-defined group of patients with AD (N = 33) who had been systematically assessed for apraxia., Methods: Patients with a biomarker-confirmed diagnosis of AD were recruited in addition to a sample of cognitively unimpaired (CU
1 ) control participants. Both groups underwent apraxia assessments with the Dementia Apraxia Screening Test. In addition, PET imaging with [18F]PI-2620 was performed to assess tau pathology in the patients with AD. To specifically investigate the association of apraxia severity with regional tau pathology, we compared the PET data from this group with an independent sample of amyloid-negative cognitively intact participants (CU2 ) by generation of z -score deviation maps and submitted these maps to a voxel-based multiple regression analysis., Results: A total of 120 participants (39% female) with a mean age of 67.9 (9.2) years were included in the study (AD = 33; CU1 ; N = 33; CU2 ; N = 54). We identified a significant correlation between circumscribed clusters of tau aggregation in praxis-related brain regions (including parietal (angular gyrus), temporal, and occipital regions) and severity of apraxia in patients with AD. By contrast, no significant correlations between tau tracer uptake in primary motor cortex or subcortical brain regions and apraxia were observed., Discussion: These results suggest that tau deposition in specific cortical praxis-related brain regions may induce local neuronal dysfunction leading to a dose-dependent functional decline in praxis performance in AD. The awareness of this relationship could further refine a differentiated individual diagnostic characterization and classification of patients with AD.- Published
- 2024
- Full Text
- View/download PDF
42. Exploring shared clinical features and successful therapeutic interventions in CARD14-associated papulosquamous eruption.
- Author
-
Rossel SVJ, Reich A, Baniel A, Wertheim-Tysarowska K, Frommherz LH, Nolberczak D, Lesiak A, Kwiek B, Osipowicz K, Bekkenk MW, Spruijt L, Seyger MMB, Kołt-Kamińska M, Giehl K, Nartbutt J, Vreeburg M, Steijlen PM, Sprecher E, van Geel M, and Gostyński AH
- Published
- 2024
- Full Text
- View/download PDF
43. Putaminal dopamine modulates movement motivation in Parkinson's disease.
- Author
-
Banwinkler M, Dzialas V, Rigoux L, Asendorf AL, Theis H, Giehl K, Tittgemeyer M, Hoenig MC, and van Eimeren T
- Subjects
- Humans, Male, Female, Middle Aged, Aged, Dopamine Plasma Membrane Transport Proteins metabolism, Hand Strength physiology, Tomography, Emission-Computed, Single-Photon, Parkinson Disease metabolism, Parkinson Disease psychology, Motivation, Dopamine metabolism, Putamen metabolism, Movement
- Abstract
The relative inability to produce effortful movements is the most specific motor sign of Parkinson's disease, which is primarily characterized by loss of dopaminergic terminals in the putamen. The motor motivation hypothesis suggests that this motor deficit may not reflect a deficiency in motor control per se, but a deficiency in cost-benefit considerations for motor effort. For the first time, we investigated the quantitative effect of dopamine depletion on the motivation of motor effort in Parkinson's disease. A total of 21 early-stage, unmedicated patients with Parkinson's disease and 26 healthy controls were included. An incentivized force task was used to capture the amount of effort participants were willing to invest for different monetary incentive levels and dopamine transporter depletion in the bilateral putamen was assessed. Our results demonstrate that patients with Parkinson's disease applied significantly less grip force than healthy controls, especially for low incentive levels. Congruously, decrease of motor effort with greater loss of putaminal dopaminergic terminals was most pronounced for low incentive levels. This signifies that putaminal dopamine is most critical to motor effort when the trade-off with the benefit is poor. Taken together, we provide direct evidence that the reduction of effortful movements in Parkinson's disease depends on motivation and that this effect is associated with putaminal dopaminergic degeneration., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)
- Published
- 2024
- Full Text
- View/download PDF
44. Sharing brain imaging data in the Open Science era: how and why?
- Author
-
Giehl K, Mutsaerts HJ, Aarts K, Barkhof F, Caspers S, Chetelat G, Colin ME, Düzel E, Frisoni GB, Ikram MA, Jovicich J, Morbelli S, Oertel W, Paret C, Perani D, Ritter P, Segura B, Wisse LEM, De Witte E, Cappa SF, and van Eimeren T
- Subjects
- Humans, Brain diagnostic imaging, Information Dissemination methods, Neuroimaging methods
- Abstract
The sharing of human neuroimaging data has great potential to accelerate the development of imaging biomarkers in neurological and psychiatric disorders; however, major obstacles remain in terms of how and why to share data in the Open Science context. In this Health Policy by the European Cluster for Imaging Biomarkers, we outline the current main opportunities and challenges based on the results of an online survey disseminated among senior scientists in the field. Although the scientific community fully recognises the importance of data sharing, technical, legal, and motivational aspects often prevent active adoption. Therefore, we provide practical advice on how to overcome the technical barriers. We also call for a harmonised application of the General Data Protection Regulation across EU countries. Finally, we suggest the development of a system that makes data count by recognising the generation and sharing of data as a highly valuable contribution to the community., Competing Interests: Declaration of interests H-JM is supported by the Dutch Heart Foundation (03-004-2020-T049), by the Eurostars-2 joint programme with cofunding from the EU Horizon 2020 Research and Innovation Programme (ASPIRE E!113701), provided by the Netherlands Enterprise Agency, and by the EU Joint Program for Neurodegenerative Disease Research, provided by the Netherlands Organisation for Health Research and Development and Alzheimer Nederland (DEBBIE JPND2020-568-106). FB is supported by the National Institute for Health and Care Research biomedical research centre at University College London Hospitals. He is part of the steering committee or Data Safety Monitoring Board member for Biogen, Merck, Alzheimer's Therapeutic Research Institute and Alzheimer's Clinical Trials Consortium, and Prothena. He is a consultant for Roche, Celltrion, Rewind Therapeutics, Merck, IXICO, Jansen, and Combinostics, has research agreements with Merck, Biogen, GE Healthcare, and Roche, and is a cofounder and shareholder of Queen Square Analytics. SC is supported by the EU Horizon 2020 Research and Innovation Programme under grant agreement number 945539 (HBP SGA3). GC has received research support from the EU Horizon 2020 Research and Innovation Programme under grant agreement number 667696, support from Fondation d'entreprise MMA des Entrepreneurs du Futur, Fondation Alzheimer, Programme Hospitalier de Recherche Clinique, Agence Nationale de la Recherche, Région Normandie, Association France Alzheimer et maladies apparentées, Fondation Vaincre Alzheimer, Fondation Recherche Alzheimer, and Fondation pour la Recherche Médicale (all to Institut National de la Santé et de la Recherche Médicale), and personal fees from Institut National de la Santé et de la Recherche Médicale (salary), Eisai, and Fondation Alzheimer. SM received speaker honoraria from GE Healthcare, Eli Lilly, and Life Molecular Imaging. PR acknowledges support by Virtual Research Environment at Charité Berlin – a node of EBRAINS Health Data Cloud, the EU Horizon Europe programme Horizon EBRAINS2.0 (101147319), Virtual Brain Twin (101137289), EBRAINS-PREP 101079717, AISN – 101057655, EBRAIN-Health101058516, Digital Europe TEF-Health 101100700, EU H2020 Virtual Brain Cloud 826421, Human Brain Project SGA2 785907; Human Brain Project SGA3 945539, ERC Consolidator 683049; German Research Foundation SFB 1436 (project ID 425899996); SFB 1315 (project ID 327654276); SFB 936 (project ID 178316478); SFB-TRR 295 (project ID 424778381); SPP Computational Connectomics RI 2073/6-1, RI 2073/10-2, RI 2073/9-1; DFG Clinical Research Group BECAUSE-Y 504745852, PHRASE Horizon EIC grant 101058240; Berlin Institute of Health & Foundation Charité, Johanna Quandt Excellence Initiative; and ERAPerMed Pattern-Cog2522FSB904. BS is supported by the María de Maeztu Unit of Excellence (Institute of Neurosciences, University of Barcelona) CEX2021-001159-M Ministry of Science, Innovation and Universities and by Generalitat de Catalunya 2021SGR0080 and the CERCA Programme/Generalitat de Catalunya. LEMW is supported by MultiPark, a strategic research area at Lund University, an National Institutes of Health grant (R01-AG070952), an Alzheimerfonden project grant (AF-980872), and a Vetenskapsradet project grant (2022-00900). TvE is a civil servant of North Rhine-Westphalia and employee of the University Hospital of Cologne, Germany. In the last 2 years, he has received honoraria, stipends, or speaker fees from the Lundbeck Foundation, Gain Therapeutics, Orion Pharma, Lundbeck Pharma, Atheneum, and the International Movement Disorders Society. He receives materials from Life Molecular Imaging and Lilly Pharma. He owns stocks of the corporations NVIDIA, Microsoft, and IBM. Multiple unrelated research projects are currently supported by the German Research Foundation. All other authors declare no competing interests., (Copyright © 2024 Elsevier Ltd. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
45. Epidermolytic ichthyosis: Clinical spectrum and burden of disease in a large German cohort.
- Author
-
Frommherz L, Giehl K, Hofmann J, Huebner S, Kiekbusch K, Sabkova T, Süßmuth K, Alter S, Tantcheva-Poór I, Ott H, Fischer J, and Has C
- Abstract
Background: Keratinopathic ichthyoses are a group of hereditary skin disorders caused by pathogenic variants in keratin genes such as KRT1, KRT2 and KRT10, resulting in conditions such as epidermolytic ichthyosis (EI), autosomal-recessive EI, superficial EI and epidermal nevus. Case reports highlight the diversity of clinical manifestations, but only limited information exists regarding the quality of life and burden of disease., Objectives: The objective of this study was to assess the clinical spectrum, genotype-phenotype correlations and burden of disease in patients with epidermolytic ichthyosis in Germany., Methods: We conducted an observational study involving 48 patients diagnosed with EI. Evaluations included the severity of skin involvement using the Investigator's Global Assessment (IGA), the modified Ichthyosis Area Severity Index (mIASI) and complications. The burden of disease was evaluated using the Dermatology Life Quality Index (DLQI) or the Children's Dermatology Life Quality Index (cDLQI)., Results: Based on clinical features, mIASI and IGA, EI can be categorized into localized, intermediate and severe forms. Patients with keratin 1 mutations tended to have severe EI, while the three forms were evenly distributed in those with keratin 10 mutations. The study highlights that around half of the patients with EI experienced itch and severe pain. Quality of life was affected, with daily life restrictions of 78% due to care and therapies. Reimbursement for moisturizing ointments by health insurance was insufficient for one-quarter of cases., Conclusions: The results emphasize the need for targeted interventions and comprehensive care strategies to enhance the quality of life for affected individuals., (© 2024 The Authors. Journal of the European Academy of Dermatology and Venereology published by John Wiley & Sons Ltd on behalf of European Academy of Dermatology and Venereology.)
- Published
- 2024
- Full Text
- View/download PDF
46. Cortical Tau Aggregation Patterns associated with Apraxia in Alzheimer's Disease.
- Author
-
Bischof GN, Jaeger E, Giehl K, Jessen F, Onur OA, O'Bryant S, Kara E, Weiss PH, and Drzezga A
- Abstract
Objectives: Apraxia is a core feature of Alzheimer's disease, but the pathomechanism of this characteristic symptom is not well understood. Here, we systematically investigated apraxia profiles in a well-defined group of patients with Alzheimer's disease (AD; N=32) who additionally underwent PET imaging with the second-generation tau PET tracer [18F]PI-2620. We hypothesized that specific patterns of tau pathology might be related to apraxic deficits., Methods: Patients (N=32) with a biomarker-confirmed diagnosis of Alzheimer's disease were recruited in addition to a sample cognitively unimpaired controls (CU
1 ; N=41). Both groups underwent in-depth neuropsychological assessment of apraxia (Dementia Apraxia Screening Test; DATE and the Cologne Apraxia Screening; KAS). In addition, static PET imaging with [18F]PI-2620 was performed to assess tau pathology in the AD patients. To specifically investigate the association of apraxia with regional tau-pathology, we compared the PET-data from this group with an independent sample of amyloid-negative cognitively intact participants (CU2; N=54) by generation of z-score-deviation maps as well as voxel- based multiple regression analyses., Results: We identified significant clusters of tau-aggregation in praxis-related regions (e.g., supramarginal gyrus, angular gyrus, temporal, parietal and occipital regions) that were associated with apraxia. These regions were similar between the two apraxia assessments. No correlations between tau-tracer uptake in primary motor cortical or subcortical brain regions and apraxia were observed., Conclusions: These results suggest that tau deposition in specific cortical brain regions may induce local neuronal dysfunction leading to a dose-dependent functional decline in praxis performance.- Published
- 2024
- Full Text
- View/download PDF
47. Association Between Years of Education and Amyloid Burden in Patients With Subjective Cognitive Decline, MCI, and Alzheimer Disease.
- Author
-
Hönig M, Altomare D, Caprioglio C, Collij L, Barkhof F, Van Berckel B, Scheltens P, Farrar G, Battle MR, Theis H, Giehl K, Bischof GN, Garibotto V, Molinuevo JLL, Grau-Rivera O, Delrieu J, Payoux P, Demonet JF, Nordberg AK, Savitcheva I, Walker Z, Edison P, Stephens AW, Gismondi R, Jessen F, Buckley CJ, Gispert JD, Frisoni GB, and Drzezga A
- Subjects
- Aged, Female, Humans, Male, Amyloid, Amyloid beta-Peptides, Amyloidogenic Proteins, Biomarkers, Educational Status, Longitudinal Studies, Positron-Emission Tomography, Multicenter Studies as Topic, Randomized Controlled Trials as Topic, Alzheimer Disease diagnostic imaging, Alzheimer Disease epidemiology, Cognitive Dysfunction diagnostic imaging, Cognitive Dysfunction epidemiology
- Abstract
Objectives: Higher-educated patients with Alzheimer disease (AD) can harbor greater neuropathologic burden than those with less education despite similar symptom severity. In this study, we assessed whether this observation is also present in potential preclinical AD stages, namely in individuals with subjective cognitive decline and clinical features increasing AD likelihood (SCD+)., Methods: Amyloid-PET information ([
18 F]Flutemetamol or [18 F]Florbetaben) of individuals with SCD+, mild cognitive impairment (MCI), and AD were retrieved from the AMYPAD-DPMS cohort, a multicenter randomized controlled study. Group classification was based on the recommendations by the SCD-I and NIA-AA working groups. Amyloid PET images were acquired within 8 months after initial screening and processed with AMYPYPE. Amyloid load was based on global Centiloid (CL) values. Educational level was indexed by formal schooling and subsequent higher education in years. Using linear regression analysis, the main effect of education on CL values was tested across the entire cohort, followed by the assessment of an education-by-diagnostic-group interaction (covariates: age, sex, and recruiting memory clinic). To account for influences of non-AD pathology and comorbidities concerning the tested amyloid-education association, we compared white matter hyperintensity (WMH) severity, cardiovascular events, depression, and anxiety history between lower-educated and higher-educated groups within each diagnostic category using the Fisher exact test or χ2 test. Education groups were defined using a median split on education (Md = 13 years) in a subsample of the initial cohort, for whom this information was available., Results: Across the cohort of 212 individuals with SCD+ (M(Age) = 69.17 years, F 42.45%), 258 individuals with MCI (M(Age) = 72.93, F 43.80%), and 195 individuals with dementia (M(Age) = 74.07, F 48.72%), no main effect of education (ß = 0.52, 95% CI -0.30 to 1.58), but a significant education-by-group interaction on CL values, was found ( p = 0.024) using linear regression modeling. This interaction was driven by a negative association of education and CL values in the SCD+ group (ß = -0.11, 95% CI -4.85 to -0.21) and a positive association in the MCI group (ß = 0.15, 95% CI 0.79-5.22). No education-dependent differences in terms of WMH severity and comorbidities were found in the subsample (100 cases with SCD+, 97 cases with MCI, 72 cases with dementia)., Discussion: Education may represent a factor oppositely modulating subjective awareness in preclinical stages and objective severity of ongoing neuropathologic processes in clinical stages.- Published
- 2024
- Full Text
- View/download PDF
48. K-Ras(V12) differentially affects the three Akt isoforms in lung and pancreatic carcinoma cells and upregulates E-cadherin and NCAM via Akt3.
- Author
-
Geißert R, Lammert A, Wirth S, Hönig R, Lohfink D, Unger M, Pek D, Schlüter K, Scheftschik T, Smit DJ, Jücker M, Menke A, and Giehl K
- Subjects
- Humans, Proto-Oncogene Proteins c-akt metabolism, Neural Cell Adhesion Molecules, Cadherins, Protein Isoforms, Phosphatidylinositol 3-Kinases metabolism, Lung metabolism, Lung Neoplasms genetics, Adenocarcinoma, Pancreatic Neoplasms pathology
- Abstract
K-Ras is the most frequently mutated Ras variant in pancreatic, colon and non-small cell lung adenocarcinoma. Activating mutations in K-Ras result in increased amounts of active Ras-GTP and subsequently a hyperactivation of effector proteins and downstream signaling pathways. Here, we demonstrate that oncogenic K-Ras(V12) regulates tumor cell migration by activating the phosphatidylinositol 3-kinases (PI3-K)/Akt pathway and induces the expression of E-cadherin and neural cell adhesion molecule (NCAM) by upregulation of Akt3. In vitro interaction and co-precipitation assays identified PI3-Kα as a bona fide effector of active K-Ras4B but not of H-Ras or N-Ras, resulting in enhanced Akt phosphorylation. Moreover, K-Ras(V12)-induced PI3-K/Akt activation enhanced migration in all analyzed cell lines. Interestingly, Western blot analyses with Akt isoform-specific antibodies as well as qPCR studies revealed, that the amount and the activity of Akt3 was markedly increased whereas the amount of Akt1 and Akt2 was downregulated in EGFP-K-Ras(V12)-expressing cell clones. To investigate the functional role of each Akt isoform and a possible crosstalk of the isoforms in more detail, each isoform was stably depleted in PANC-1 pancreatic and H23 lung carcinoma cells. Akt3, the least expressed Akt isoform in most cell lines, is especially upregulated and active in Akt2-depleted cells. Since expression of EGFP-K-Ras(V12) reduced E-cadherin-mediated cell-cell adhesion by induction of polysialylated NCAM, Akt3 was analyzed as regulator of E-cadherin and NCAM. Western blot analyses revealed pronounced reduction of E-cadherin and NCAM in the Akt3-kd cells, whereas Akt1 and Akt2 depletion upregulated E-cadherin, especially in H23 lung carcinoma cells. In summary, we identified oncogenic K-Ras4B as a key regulator of PI3-Kα-Akt signaling and Akt3 as a crucial regulator of K-Ras4B-induced modulation of E-cadherin and NCAM expression and localization., (© 2024. The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
49. Affection of Motor Network Regions by Tau Pathology Across the Alzheimer's Disease Spectrum.
- Author
-
Bischof GN, Jaeger E, Giehl K, Hönig MC, Weiss PH, and Drzezga A
- Subjects
- Humans, tau Proteins metabolism, Neuroimaging, Positron-Emission Tomography methods, Amyloid beta-Peptides metabolism, Alzheimer Disease pathology, Cognitive Dysfunction metabolism
- Abstract
Stereotypical isocortical tau protein pathology along the Braak stages has been described as an instigator of neurodegeneration in Alzheimer's disease (AD). Less is known about tau pathology in motor regions, although higher-order motor deficits such as praxis dysfunction are part of the clinical description. Here, we examined how tau pathology in cytoarchitectonically mapped regions of the primary and higher-order motor network in comparison to primary visual and sensory regions varies across the clinical spectrum of AD. We analyzed tau PET scans from the Alzheimer's Disease Neuroimaging Initiative (ADNI) cohort in patients with mild cognitive impairment (MCI; N = 84) and dementia of the Alzheimer's disease type (DAD; N = 25). Additionally, an amyloid-negative sample of healthy older individuals (HC; N = 26) were included. Standard uptake ratio values (SUVRs) were extracted in native space from the left and the right hemispheres. A repeated measurement analysis of variance was conducted to assess the effect of diagnostic disease category on tau pathology in the individual motor regions, controlling for age. We observed that tau pathology varies as a function of diagnostic category in predominantly higher motor regions (i.e., supplementary motor area, superior parietal lobe, angular gyrus, and dorsal premotor cortex) compared to primary visual, sensory and motor regions. Indeed, tau in higher-order motor regions was significantly associated with decline in cognitive function. Together, these results expand our knowledge on the in vivo pattern of tau pathology in AD and suggest that higher motor regions are not spared from tau aggregation in the course of disease, potentially contributing to the symptomatic appearance of the disease., (Copyright © 2024 Bischof et al.)
- Published
- 2024
- Full Text
- View/download PDF
50. Working Memory Training Responsiveness in Parkinson's Disease Is Not Determined by Cortical Thickness or White Matter Lesions.
- Author
-
Giehl K, Theis H, Ophey A, Hammes J, Reker P, Eggers C, Fink GR, Kalbe E, and van Eimeren T
- Subjects
- Humans, Cognitive Training, Magnetic Resonance Imaging methods, Brain pathology, Neuropsychological Tests, Parkinson Disease complications, White Matter diagnostic imaging, White Matter pathology, Cognitive Dysfunction complications
- Abstract
Patients with Parkinson's disease are highly vulnerable for cognitive decline. Thus, early intervention by means of working memory training (WMT) may be effective for the preservation of cognition. However, the influence of structural brain properties, i.e., cortical thickness and volume of white matter lesions on training responsiveness have not been studied. Here, behavioral and neuroimaging data of 46 patients with Parkinson's disease, 21 of whom engaged in home-based, computerized adaptive WMT, was analyzed. While cortical thickness and white matter lesions volume were associated with cognitive performance at baseline, these structural brain properties do not seem to determine WMT responsiveness.
- Published
- 2024
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.