Sylvia Lehmann

Dr. Sylvia Lehmann

orcid

Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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Verified
Journal Article
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DADalel Askri
Dalel Askri
VCValerie CUNIN
Valerie CUNIN
SOSouhir Ouni
Souhir Ouni
DBDavid Béal
David Béal
WRWalid Rachidi
Walid Rachidi
Michel SEVEMichel SEVE
Michel SEVE
Iron Oxide Nanoparticles (IONPs) present unique properties making them one of the most used NPs in the biomedical field. Nevertheless, for many years, growing production and use of IONPs are associated with risks that can affect human and the environment. Thus, it is essential to study the effects of these nanoparticles to better understand their mechanism of action and the molecular perturbations induced in the organism. In the present study, we investigated the toxicological effects of IONPs (γ-Fe2O3) on liver, lung and brain proteomes in Wistar rats. Exposed rats received IONP solution during 7 consecutive days by intranasal instillation at a dose of 10 mg/kg body weight. An iTRAQ-based quantitative proteomics was used to study proteomic variations at the level of the three organs. Using this proteomic approach, we identified 1565; 1135 and 1161 proteins respectively in the brain, liver and lung. Amon them, we quantified 1541; 1125 and 1128 proteins respectively in the brain, liver and lung. Several proteins were dysregulated comparing treated samples to controls, particularly, proteins involved in cytoskeleton remodeling, cellular metabolism, immune system stimulation, inflammation process, response to oxidative stress, angiogenesis, and neurodegenerative diseases.

21 May 2013 in PLOS ONE
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AHAndreas-Claudius Hoffmann
Andreas-Claudius Hoffmann
EGEray Goekkurt
Eray Goekkurt
PDPeter V. Danenberg
Peter V. Danenberg
SLSylvia Lehmann
Sylvia Lehmann
GEGerhard Ehninger
Gerhard Ehninger
JSJan Stoehlmacher-Williams
Jan Stoehlmacher-Williams
Background Cholangiocarcinoma remains to be a tumor with very few treatment choices and limited prognosis. In this study, we sought to determine the prognostic role of fms-related tyrosine kinase 1/vascular endothelial growth factor receptor 1 ( FLT1/VEGFR1 ), heparanase ( HPSE ) and epidermal growth factor receptor ( EGFR ) gene expression in patients with resected CCC. Methods 47 formalin-fixed paraffin embedded FFPE tumor samples from patients with resected CCC were analyzed. FFPE tissues were dissected using laser-captured microdissection and analyzed for FLT1 , FLT4 , HPSE , Hif1a , VEGFA/C , HB-EGF , PDGFA , PDGF-RA and EGFR mRNA expression using a quantitative real-time RT-PCR method. Gene expression values (relative mRNA levels) are expressed as ratios between the target gene and internal reference genes (beta-actin, b2mg, rplp2, sdha). Results EGFR , FLT1 and HPSE expression levels were significantly associated with overall survival (OS). FLT1 showed the strongest significant independent association with overall survival in a multivariate cox regression analysis when compared to the other genes and clinicopathological factors with a nearly 5 times higher relative risk (4.74) of dying earlier when expressed in low levels (p = 0.04). ROC Curve Analysis revealed that measuring EGFR potentially identifies patients at risk of a worsened outcome with a sensitivity of 80% and a specificity of 75% (p = 0.01). Conclusions EGFR and FLT1 seem to be potential markers to identify those patients at high risk of dying from cholangiocarcinoma. Therefore these markers may help to identify patient subgroups in need for a more aggressive approach in a disease that is in desperate need for new approaches.

1 January 2017 in Oxidative Medicine and Cellular Longevity
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SLSylvia Lehmann
Sylvia Lehmann
Sandrine Bourgoin-VoillardSandrine Bourgoin-Voillard
Sandrine Bourgoin-Voillard
Michel SEVEMichel SEVE
Michel SEVE
WRWalid Rachidi
Walid Rachidi
Skin aging is a complex process, and a lot of efforts have been made to identify new and specific targets that could help to diagnose, prevent, and treat skin aging. Several studies concerning skin aging have analyzed the changes in gene expression, and very few investigations have been performed at the protein level. Moreover, none of these proteomic studies has used a global quantitative labeled proteomic offgel approach that allows a more accurate description of aging phenotype. We applied such an approach on human primary keratinocytes obtained from sun‐nonexposed skin biopsies of young and elderly women. A total of 517 unique proteins were identified, and 58 proteins were significantly differentially expressed with 40 that were downregulated and 18 upregulated with aging. Gene ontology and pathway analysis performed on these 58 putative biomarkers of skin aging evidenced that these dysregulated proteins were mostly involved in metabolism and cellular processes such as cell cycle and signaling pathways. Change of expression of tubulin beta‐3 chain was confirmed by western blot on samples originated from several donors. Thus, this study suggested the tubulin beta‐3 chain has a promising biomarker in skin aging.

11 April 2018 in Nanomaterials
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SLSylvia Lehmann
Sylvia Lehmann
BGBenjamin Gilbert
Benjamin Gilbert
TMThierry Maffeis
Thierry Maffeis
AGAlexei Grichine
Alexei Grichine
IPIsabelle Pignot-Paintrand
Isabelle Pignot-Paintrand
LCLaurent Charlet
Laurent Charlet
Silver nanowires (AgNW) are attractive materials that are anticipated to be incorporated into numerous consumer products such as textiles, touchscreen display, and medical devices that could be in direct contact with skin. There are very few studies on the cellular toxicity of AgNW and no studies that have specifically evaluated the potential toxicity from dermal exposure. To address this question, we investigated the dermal toxicity after acute exposure of polymer-coated AgNW with two sizes using two models, human primary keratinocytes and human reconstructed epidermis. In keratinocytes, AgNW are rapidly and massively internalized inside cells leading to dose-dependent cytotoxicity that was not due to Ag+ release. Analysing our data with different dose metrics, we propose that the number of NW is the most appropriate dose-metric for studies of AgNW toxicity. In reconstructed epidermis, the results of a standard in vitro skin irritation assay classified AgNW as non-irritant to skin and we found no evidence of penetration into the deeper layer of the epidermis. The findings show that healthy and intact epidermis provides an effective barrier for AgNW, although the study does not address potential transport through follicles or injured skin. The combined cell and tissue model approach used here is likely to provide an important methodology for assessing the risks for skin exposure to AgNW from consumer products.

1 December 2018 in Journal of Trace Elements in Medicine and Biology
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DADalel Askri
Dalel Askri
SOSouhir Ouni
Souhir Ouni
SGSaid Galai
Said Galai
BCBenoit Chovelon
Benoit Chovelon
JAJosiane Arnaud
Josiane Arnaud
SASalem Amara
Salem Amara