TY - GEN A1 - Schlör, Anja A1 - Holzlöhner, Pamela A1 - Listek, Martin A1 - Grieß, Cindy A1 - Butze, Monique A1 - Micheel, Burkhard A1 - Hentschel, Christian A1 - Sowa, Mandy A1 - Roggenbuck, Dirk A1 - Schierack, Peter A1 - Füner, Jonas A1 - Schliebs, Erik A1 - Goihl, Alexander A1 - Reinhold, Dirk A1 - Hanack, Katja T1 - Generation and validation of murine monoclonal and camelid recombinant single domain antibodies specific for human pancreatic glycoprotein 2 T2 - New Biotechnology Y1 - 2018 U6 - https://doi.org/10.1016/j.nbt.2018.03.006 SN - 1876-4347 SN - 1871-6784 VL - 45 SP - 60 EP - 68 ER - TY - GEN A1 - Lutter, Anne-Helen A1 - Liedtke, Victoria A1 - Ecke, Annemarie A1 - Scholka, Jenny A1 - Muschter, Antje A1 - Hentschel, Erik A1 - Becker, Roland A1 - Anderer, Ursula T1 - Direct co-culture of human chondrogenic microtissues with osteoblast-like Saos-2 cells positively influence the differentiation potential of cartilage cells in 3D culture Y1 - 2018 U6 - https://doi.org/10.1007%2Fs10354-018-0664-9.pdf N1 - Austrian Bone Conference – ABC 2018, November 23–24, 2018, Vienna, Austria ER - TY - GEN A1 - Majchrzak, Karolina A1 - Hentschel, Erik A1 - Hönzke, Katja A1 - Geithe, Christiane A1 - Maltzahn, Julia von T1 - We need to talk—how muscle stem cells communicate T2 - Frontiers in Cell and Developmental Biology N2 - Skeletal muscle is one of the tissues with the highest ability to regenerate, a finely controlled process which is critically depending on muscle stem cells. Muscle stem cell functionality depends on intrinsic signaling pathways and interaction with their immediate niche. Upon injury quiescent muscle stem cells get activated, proliferate and fuse to form new myofibers, a process involving the interaction of multiple cell types in regenerating skeletal muscle. Receptors in muscle stem cells receive the respective signals through direct cell-cell interaction, signaling via secreted factors or cell-matrix interactions thereby regulating responses of muscle stem cells to external stimuli. Here, we discuss how muscle stem cells interact with their immediate niche focusing on how this controls their quiescence, activation and self-renewal and how these processes are altered in age and disease. KW - muscle stem cell KW - satellite cell KW - skeletal muscle KW - regeneration KW - niche KW - receptor KW - aging KW - rhabdomyosarcoma Y1 - 2024 U6 - https://doi.org/10.3389/fcell.2024.1378548 SN - 2296-634X VL - 12 PB - Frontiers Media S.A. ER - TY - GEN A1 - Martin, Frank A1 - Neubert, Annemarie A1 - Lutter, Anne-Helen A1 - Scholka, Jenny A1 - Hentschel, Erik A1 - Richter, Heiko A1 - Anderer, Ursula T1 - MTS, WST-8, and ATP viability assays in 2D and 3D cultures: Comparison of methodologically different assays in primary human chondrocytes T2 - Clinical Hemorheology and Microcirculation N2 - BACKGROUND: Tissue engineering enables the production of three-dimensional microtissues which mimic naturally occurring conditions in special tissues. These 3D culture systems are particularly suitable for application in regenerative medicine or experimental pharmacology and toxicology. Therefore, it is important to analyse the cells in their 3D microenvironment with regard to viability and differentiation. Tetrazolium assays (WST-8 and MTS) are still the methods of choice for estimating the number of living, metabolically active cells, with WST-8 being cell-impermeable compared to MTS. In contrast to these methods, the ATP assay is an endpoint method based on the luciferase-induced reaction of ATP with luciferin after cell lysis. OBJECTIVE:We compared three methodologically different proliferation/toxicity assays (MTS, WST-8, ATP) in monolayer (2D) and 3D culture systems to improve the technically challenging determination of the number of viable cells. METHODS: Chondrocytes were isolated from human articular cartilage. Three different test systems (MTS, WST-8, ATP) were applied to monolayer cells (2D, varying cell numbers) and spheroids (3D, different sizes) in 96-well plates. The intracellular ATP concentration was determined by luciferase-induced reaction of ATP with luciferin using a luminometer. Formazan formation was measured spectrophotometrically after different incubation periods. Evaluation was performed by phase contrast microscopy (toxicity), correlation of cell count and ATP concentration or absorption signal (Gompertz function) and propidium iodide (PI) staining to proof the cell lysis of all cells in spheroids. RESULTS: In 2D culture, all three assays showed a good correlation between the number of seeded cells and the ATP concentration or absorption data, whereas the MTS-assay showed the lowest specificity. In 3D culture, the spheroid sizes were directly related to the number of cells seeded. The absorption data of the WST-8 and MTS assay correlated only for certain spheroid size ranges, whereas the MTS-assay showed again the lowest specificity. Only the measured intracellular ATP content showed a linear correlation with all spheroid sizes ranging from 100–1000 µm. The WST-8 assay revealed the second-best sensitivity which allows the measurement of spheroids larger than 240 µm. Phase contrast observation of monolayer cells showed toxic effects of MTS after 6 h incubation and no signs of toxicity of WST-8. Staining with propidium iodide showed complete lysis of all cells in a spheroid in the ATP assay. CONCLUSION: Among tetrazolium-based assays, WST-8 is preferable to MTS because of its non-toxicity and better sensitivity. When determining the number of viable cells in the 2D system, caution is advised when using the ATP assay because of its two-phase slope of the correlation graph concerning cell number and intracellular ATP. In 3D systems of human chondrocytes, the ATP-assay is superior to the other two test systems, as the correlation graph between cell number and intracellular ATP is biphasic. Since differentiation processes or other metabolic events can influence the results of proliferation and toxicity assays (determination of viable cells), this should be taken into account when using these test systems. KW - ATP assay KW - MTS KW - WST-8 KW - Human chondrocytes KW - Spheroid KW - 3D culture KW - 2D culture Y1 - 2024 UR - https://journals.sagepub.com/doi/abs/10.3233/CH-248101 U6 - https://doi.org/10.3233/CH-248101 SN - ISSN 1386-0291 VL - 88 SP - 3 EP - 19 PB - IOS Press ER -