Publications by authors named "Karen Bieback"

Cell cultures form the backbone for scientific research and development, but also for clinical diagnostics and biotechnology. Supplying cells with growth factors, hormones, and other nutrients is achieved most often by supplementing culture media with fetal bovine serum (FBS). Despite its nearly ubiquitous use, there are major reproducibility, safety, and animal welfare issues arguing the need to replace FBS.

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Introduction: Red blood cells (RBCs) undergo progressive biochemical and morphological changes during storage, collectively called storage lesion. The quality of red cell concentrates (RCCs) is typically assessed by quantifying hemolysis. An assessment of morphological changes, associated with low quality RBCs, could give an additional indication of the safety and efficacy of the concentrates.

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Head and neck squamous cell carcinoma (HNSCC) are invasive solid tumors accounting for high mortality. To improve the clinical outcome, a better understanding of the tumor and its microenvironment (TME) is crucial. Three -dimensional (3D) bioprinting is emerging as a powerful tool for recreating the TME in vitro.

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  • Pathological cardiac remodeling can lead to heart failure, and the study focused on two long non-coding RNAs (lncRNAs) that are upregulated in failing hearts.
  • Overexpressing these lncRNAs in mice worsened heart dysfunction and increased hypertrophy and fibrosis in response to pressure overload.
  • Knocking out these lncRNAs reduced heart damage and improved blood vessel growth but also led to sudden death in some mice, highlighting their complex role in heart failure and potential as therapeutic targets.
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Endothelial dysfunction contributes to the pathogenesis of Takotsubo syndrome (TTS). However, the exact mechanism underlying endothelial dysfunction in the setting of TTS has not been completely clarified. This study aims to investigate the roles of angiotensin II (Ang II) and intermediate-conductance Ca-activated K (SK4) channels in catecholamine-induced endothelial dysfunction.

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Background Aims: Mesenchymal stromal cells (MSCs) are attractive as a therapeutic modality in multiple disease conditions characterized by inflammation and vascular compromise. Logistically they are advantageous because they can be isolated from adult tissue sources, such as bone marrow (BM). The phase 2a START clinical trial determined BM-MSCs to be safe in patients with moderate-to-severe acute respiratory distress syndrome (ARDS).

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  • Acute kidney injury (AKI) is a quick decline in kidney function, often triggered by the cancer drug cisplatin, and current treatments to reverse it are lacking effectiveness.
  • Mesenchymal stromal cells (MSCs), particularly those expressing ABCB5, have shown promise in treating inflammatory conditions and improving kidney function in preclinical studies.
  • In an experiment on rats, ABCB5+ MSCs effectively reduced cell death in kidney cells, inhibited immune cell proliferation, and modulated inflammation responses, indicating their potential as a therapy for cisplatin-induced AKI.
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(1) Background: The chemotherapeutic drug cisplatin exerts toxic side effects causing acute kidney injury. Mesenchymal stromal cells can ameliorate cisplatin-induced kidney injury. We hypothesize that the MSC secretome orchestrates the vicious cycle of injury and inflammation by acting on proximal tubule epithelial cells (PTECs) and macrophages individually, but further by counteracting their cellular crosstalk.

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Small extracellular vesicles from saliva (SEVs) have high potential as biomarkers in Head and Neck cancer (HNC). However, there is no common consensus on the ideal method for their isolation. This study compared different ultracentrifugation (UC) methods (durations and + /- additional purification) with size exclusion chromatography (SEC) and investigated the potential of SEVs as diagnostic biomarkers and their biological activity on NK and CD8 T cells.

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  • Adipose-derived stem cells (ASCs) are being tested in clinical trials as a treatment for peripheral artery disease (PAD), focusing on their impact on hypoxic endothelial cells and stress responses in a mouse model.* -
  • The study found that ASCs improved cell survival under hypoxic conditions by reducing endoplasmic reticulum (ER) stress and promoting muscle recovery in mice with induced ischemia.* -
  • The treatment with ASCs showed decreased muscle necrosis, inflammation, and improved enzyme levels, suggesting that ASCs could be a promising alternative therapy for PAD patients unable to undergo traditional procedures.*
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The C-type lectin-like receptor 2 (CLEC-2) is expressed on platelets and mediates binding to podoplanin (PDPN) on various cell types. The binding to circulating tumor cells (CTCs) leads to platelet activation and promotes metastatic spread. An increased level of soluble CLEC-2 (sCLEC-2), presumably released from activated platelets, was shown in patients with thromboinflammatory and malignant disease.

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  • Autologous stem cell transplantation is a common procedure with few non-engraftment cases, but the time it takes for patients to recover blood cell production varies widely.
  • The study used advanced multicolor flow cytometry to analyze CD34 subpopulations in cryopreserved stem cell samples and found a significant variation in HSPC distribution compared to existing data.
  • Higher levels of immature lympho-myeloid progenitors correlated with quicker recovery of neutrophils and leukocytes, while differentiated cells were linked to slower recovery times.
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Background: Extracellular vesicles (EV) are considered a cell-free alternative to mesenchymal stromal cell (MSC) therapy. Numerous reports describe the efficacy of EV in conferring immunomodulation and promoting angiogenesis, yet others report these activities to be conveyed in EV-free bioproducts. We hypothesized that this discrepancy may depend either on the method of isolation or rather the relative impact of the individual bioactive components within the MSC secretome.

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Background: The driver of secondary lymphedema (SL) progression is chronic inflammation, which promotes fibrosis. Despite advances in preclinical research, a specific effector cell subpopulation as a biomarker for therapy response or stage progression is still missing for SL.

Methods: Whole skin samples of 35 murine subjects of a microsurgically induced SL model and 12 patients with SL were collected and their fibroblasts were isolated.

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Mesenchymal stromal cells (MSCs) have been reported to display efficacy in a variety of preclinical models, but without long-term engraftment, suggesting a role for secreted factors, such as MSC-derived extracellular vesicles (EVs). MSCs are known to elicit immunomodulatory effects, an important aspect of which is their ability to affect macrophage phenotype. However, it is not clear if these effects are mediated by MSC-derived EVs, or other factors secreted by the MSCs.

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Although checkpoint inhibitors (CPI) have recently extended the treatment options and improved clinical response of advanced stage head and neck squamous cell carcinoma (HNSCC), treatment success remains unpredictable. Programmed cell death ligand‑1 (PD‑L1) is a key player in immunotherapy. Tumor cells, and exosomes derived therefrom, are carriers of PD‑L1 and efficiently suppress immune responses.

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Background: Mesenchymal stromal cells (MSCs), commonly sourced from adipose tissue, bone marrow and umbilical cord, have been widely used in many medical conditions due to their therapeutic potential. Yet, the still limited understanding of the underlying mechanisms of action hampers clinical translation. Clinical potency can vary considerably depending on tissue source, donor attributes, but importantly, also culture conditions.

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Human Mesenchymal Stromal Cells (hMSCs) are a promising source for cell-based therapies. Yet, transition to phase III and IV clinical trials is remarkably slow. To mitigate donor variabilities and to obtain robust and valid clinical data, we aimed first to develop a manufacturing concept balancing large-scale production of pooled hMSCs in a minimal expansion period, and second to test them for key manufacture and efficacy indicators in the clinically highly relevant indication wound healing.

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Cell culture techniques are strongly connected with modern scientific laboratories and production facilities. Thus, choosing the most suitable medium for the cells involved is vital, not only directly to optimise cell viability but also indirectly to maximise the reliability of the experiments performed with the cells. Fetal bovine or calf serum (FBS or FCS, respectively) is the most commonly used cell culture medium supplement, providing various nutritional factors and macromolecules essential for cell growth.

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  • Endothelial cells derived from human induced pluripotent stem cells (hiPSC-ECs) present a novel avenue for studying vascular regeneration and testing drugs, though their functions require further exploration.
  • This study focuses on comparing the electrophysiological and functional characteristics of hiPSC-ECs with primary human cardiac microvascular endothelial cells (HCMECs), particularly examining ion channels and membrane signaling.
  • Results indicate that while hiPSC-ECs exhibit higher mRNA levels for certain ion channels and receptors compared to HCMECs, their essential functional characteristics—like tube formation and LDL uptake—are similar between the two cell types.
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Background: Transfusion of red cell concentrates (RCCs) is an integral therapy after severe hemorrhage or trauma. Prehospital transfusion offers an immediate intervention in emergency cases. Air ambulance-based prehospital transfusion, already used in different countries, is currently established in Germany.

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Immunotherapy has evolved into a powerful tool in the fight against a number of types of cancer, including head and neck squamous cell carcinomas (HNSCC). Although checkpoint inhibition (CPI) has definitely enriched the treatment options for advanced stage HNSCC during the past decade, the percentage of patients responding to treatment is widely varying between 14‑32% in second‑line setting in recurrent or metastatic HNSCC with a sporadic durability. Clinical response and, consecutively, treatment success remain unpredictable in most of the cases.

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  • Cystic kidney disease (CKD) is a genetic disorder leading to severe kidney issues, and this study explores the effects of long-term stem cell therapy on CKD in PKD/Mhm (Cy/+) rats.
  • Human adipose-derived stromal cells (ASC) and ABCB5 stromal cells were administered monthly for six months, which resulted in notable changes in gene expression related to metabolic pathways and a moderate improvement in kidney function.
  • The findings suggest that cell-based therapies might offer a new treatment avenue for CKD, with promising initial results warranting further investigation.
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Background: Previous studies suggested involvement of non-ß-adrenoceptors in the pathogenesis of Takotsubo cardiomyopathy (TTC). This study was designed to explore possible roles and underlying mechanisms of dopamine D1/D5 receptor coupled signaling in arrhythmogenesis of TTC.

Methods: Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were challenged by toxic concentration of epinephrine (Epi, 0.

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Intraoperative radiotherapy (IORT) displays an increasingly used treatment option for early breast cancer. It exhibits non-inferiority concerning the risk of recurrence compared to conventional external irradiation (EBRT) in suitable patients with early breast cancer. Since most relapses occur in direct proximity of the former tumor site, the reduction of the risk of local recurrence effected by radiotherapy might partially be due to an alteration of the irradiated tumor bed's micromilieu.

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