The Journey of SCAPs (Stem Cells from Apical Papilla), from Their Native Tissue to Grafting: Impact of Oxygen Concentration

Tissue engineering strategies aim at characterizing and at optimizing the cellular component that is combined with biomaterials, for improved tissue regeneration. Here, we present the immunoMap of apical papilla, the native tissue from which SCAPs are derived. We characterized stem cell niches that correspond to a minority population of cells expressing Mesenchymal stromal/Stem Cell (CD90, CD105, CD146) and stemness (SSEA4 and CD49f) markers as well as endothelial cell markers (VWF, CD31). Based on the colocalization of TKS5 and cortactin markers, we detected migration-associated organelles, podosomes-like structures, in specific regions and, for the first time, in association with stem cell niches in normal tissue. From six healthy teenager volunteers, each with two teeth, we derived twelve cell banks, isolated and amplified under 21 or 3% O2. We confirmed a proliferative advantage of all banks when cultured under 3% versus 21% O2. Interestingly, telomerase activity was similar to that of the highly proliferative hiPSC cell line, but unrelated to O2 concentration. Finally, SCAPs embedded in a thixotropic hydrogel and implanted subcutaneously in immunodeficient mice were protected from cell death with a slightly greater advantage for cells preconditioned at 3% O2

Telomerase Activation in Hematological Malignancies

Telomerase expression and telomere maintenance are critical for cell proliferation and survival, and they play important roles in development and cancer, including hematological malignancies. Transcriptional regulation of the rate-limiting subunit of human telomerase reverse transcriptase gen (hTERT) is a complex process, and unveiling the mechanisms behind its reactivation is an important step for the development of diagnostic and therapeutic applications. Here, we review the main mechanisms of telomerase activation and the associated hematologic malignancies

L’effet du bruit de parole indésirable dans les open-space : expérience en laboratoire

National audienceLe bruit de parole est maintenant accepté comme la source principale de gêne pour les employées des open space. Ce travail poursuit une série d’études faites au sein de l’INRS et l’INSA de Lyon basées sur le modèle théorique d’Hongisto, qui relie un Décrément de Performance (DP) et l’indicateur de la transmission de la parole STI (Speech Transmission Index). Ce modèle prédit que pour des valeurs de STI de 0.7 à 1, ce qui traduit un signal de parole avec une intelligibilité presque de 100 %, le DP reste constant à 7 %. L’expérience que nous avons fait a pour but de collecter plus d’information sur la relation entre le DP et le STI, en faisant varié le STI jusqu’à 0.9. Cinquante-cinq sujets entre 25 et 59 ans ont passé l’expérience. Premièrement, quelques paramètres psychologiques ont été observés pour une meilleure caractérisation de la variabilité interindividuelle. Ensuite, les sujets ont passé une tâche de mémoire de travail (WM) en silence et en quatre conditions différentes de bruit (STI de 0.25 à 0.9). Cette tâche a été personnalisée par une mesure initiale de l’empan mnésique. Cela a permis de définir deux différentes charges cognitives (lourde / légère) autour de la valeur de l’empan de chaque sujet. Les sujets ont évalué subjectivement la charge mentale et la gêne à la fin de chaque tâche WM de chaque condition sonore. Les résultats ont montré un effet significatif entre le STI et le DP, la charge mentale et la gêne. De plus, une corrélation significative a été trouvée entre l’âge des sujets et leur performance pendant la tâche WM

IRRELEVANT SPEECH EFFECT IN OPEN PLAN OFFICES: A LABORATORY STUDY

International audienceIt seems now accepted that speech noise in open plan offices is the main source of discomfort for employees. This work follows a series of studies conducted at INRS France and INSA Lyon based on Hongisto's theoretical model (2005) linking the Decrease in Performance (DP) and the Speech Transmission Index (STI). This model predicts that for STI values between 0.7 and 1, which means a speech signal close to 100% of intelligibility, the DP remains constant at about 7%. The experiment that we carried out aimed to gather more information about the relation between DP and STI, varying the STI value up to 0.9. Fifty-five subjects between 25-59 years old participated in the experiment. First, some psychological parameters were observed in order to better characterize the inter-subjects variability. Then, subjects performed a Working-Memory (WM) task in silence and in four different sound conditions (STI from 0.25 to 0.9). This task was customized by an initial measure of mnemonic span so that two different cognitive loads (low/high) were equally defined for each subject around their span value. Subjects also subjectively evaluated their mental load and discomfort at the end of each WM task, for each noise condition. Results show a significant effect of the STI on the DP, the mental load and the discomfort. Furthermore, a significant correlation was found between the age of subjects and their performance during the WM task. This result was confirmed by a cluster analysis that enabled us to separate the subjects on two different groups, one group of younger and more efficient subjects and one group of older and less efficient subjects. General results did not show any increase of DP for the highest STI values, so the "plateau" hypothesis of Hongisto's model cannot be rejected on the basis of this experiment

Delving into the Metabolism of Sézary Cells: A Brief Review

Primary cutaneous lymphomas (PCLs) are a heterogeneous group of lymphoproliferative disorders caused by the accumulation of neoplastic T or B lymphocytes in the skin. Sézary syndrome (SS) is an aggressive and rare form of cutaneous T cell lymphoma (CTCL) characterized by an erythroderma and the presence of atypical cerebriform T cells named Sézary cells in skin and blood. Most of the available treatments for SS are not curative, which means there is an urgent need for the development of novel efficient therapies. Recently, targeting cancer metabolism has emerged as a promising strategy for cancer therapy. This is due to the accumulating evidence that metabolic reprogramming highly contributes to tumor progression. Genes play a pivotal role in regulating metabolic processes, and alterations in these genes can disrupt the delicate balance of metabolic pathways, potentially contributing to cancer development. In this review, we discuss the importance of targeting energy metabolism in tumors and the currently available data on the metabolism of Sézary cells, paving the way for potential new therapeutic approaches aiming to improve clinical outcomes for patients suffering from SS

hMZF-2, the Elusive Transcription Factor

International audienc