Publications by authors named "Tim Eiseler"

Background: We have previously identified an unsuspected role for GJB3 showing that the deficiency of this connexin protein induces aneuploidy in human and murine cells and accelerates cell transformation as well as tumor formation in xenograft models. The molecular mechanisms by which loss of GJB3 leads to aneuploidy and cancer initiation and progression remain unsolved.

Methods: GJB3 expression levels were determined by RT-qPCR and Western blot.

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Article Synopsis
  • * The INTERaction with Organoid-in-MatriX ("InterOMaX") model provides a 3D co-culture system that closely mimics the tumor microenvironment (TME), allowing researchers to explore how cancer cells and T cells interact.
  • * This model facilitates the discovery of new molecular mechanisms affecting T cell responses to PDAC, which could lead to improved understanding of why some cancer cells resist treatment and ultimately enhance therapeutic strategies.
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Discovered in the late eighties, sEVs are small extracellular nanovesicles (30-150 nm diameter) that gained increasing attention due to their profound roles in cancer, immunology, and therapeutic approaches. They were initially described as cellular waste bins; however, in recent years, sEVs have become known as important mediators of intercellular communication. They are secreted from cells in substantial amounts and exert their influence on recipient cells by signaling through cell surface receptors or transferring cargos, such as proteins, RNAs, miRNAs, or lipids.

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Article Synopsis
  • Scientists found that a protein called ORP3 helps control cell numbers and can stop cancer from forming.
  • In bladder cancer, ORP3 is less active as the cancer gets worse, and when it’s missing, cancer becomes more likely.
  • ORP3 helps keep cells stable and affects their movement, showing it plays a big part in stopping cancer from spreading.
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Trauma is a major cause of death worldwide. The post-traumatic immune response culminates in the release of pro-inflammatory mediators, translating in the infiltration of neutrophils (PMNs) at injury sites. The extent of this inflammation is determined by multiple factors, such as PMN adhesion to the endothelium, transendothelial migration, endothelial barrier integrity as well as PMN swarming, mass infiltration and activation.

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Mesenchymal stromal cells (MSCs) are promising therapeutic candidates in a variety of diseases due to having immunomodulatory and pro-regenerative properties. In recent years, MSC-derived small extracellular vesicles (sEVs) have attracted increasing interest as a possible alternative to conventional cell therapy. However, translational processes of sEVs for clinical applications are still impeded by inconsistencies regarding isolation procedures and culture conditions.

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Cell migration plays an essential role in wound healing and inflammatory processes inside the human body. Peripheral blood neutrophils, a type of polymorphonuclear leukocyte (PMN), are the first cells to be activated during inflammation and subsequently migrate toward an injured tissue or infection site. This response is dependent on both biochemical signaling and the extracellular environment, one aspect of which includes increased temperature in the tissues surrounding the inflammation site.

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Pancreatic ductal adenocarcinomas (PDACs) are tumors with poor prognosis and limited treatment options. Personalized medicine aims at characterizing actionable DNA variants by next-generation sequencing, thereby improving treatment strategies and outcomes. Fine-needle tumor biopsies are currently the gold standard to acquire samples for DNA profiling.

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Trauma is the leading cause of death in individuals under 44 years of age. Thorax trauma (TxT) is strongly associated with trauma-related death, an unbalanced innate immune response, sepsis, acute respiratory distress syndrome, and multiple organ dysfunction. It is shown that different in vivo traumata, such as TxT or an in vitro polytrauma cytokine cocktail trigger secretion of small extracellular nanovesicles (sEVs) from endothelial cells with pro-inflammatory cargo.

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Even with all recent advances in cancer therapy, pancreatic cancer still has a dismal 5-year survival rate of less than 7%. The most prevalent tumor subtype is pancreatic ductal adenocarcinoma (PDAC). PDACs display an extensive crosstalk with their tumor microenvironment (TME), e.

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Cancer is a complex disease, driven by genetic defects and environmental cues. Systemic dissemination of cancer cells by metastasis is generally associated with poor prognosis and is responsible for more than 90% of cancer deaths. Metastasis is thought to follow a sequence of events, starting with loss of epithelial features, detachment of tumor cells, basement membrane breakdown, migration, intravasation and survival in the circulation.

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Infection-related diabetes can arise as a result of virus-associated β-cell destruction. Clinical data suggest that the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), causing the coronavirus disease 2019 (COVID-19), impairs glucose homoeostasis, but experimental evidence that SARS-CoV-2 can infect pancreatic tissue has been lacking. In the present study, we show that SARS-CoV-2 infects cells of the human exocrine and endocrine pancreas ex vivo and in vivo.

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Background & Aims: Pancreatic tumor cells release small extracellular vesicles (sEVs, exosomes) that contain lipids and proteins, RNA, and DNA molecules that might promote formation of metastases. It is not clear what cargo these vesicles contain and how they are released. Protein kinase D1 (PRKD1) inhibits cell motility and is believed to be dysregulated in pancreatic ductal adenocarcinomas.

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Constitutive secretion from the trans-Golgi-network (TGN) is facilitated by a concerted regulation of vesicle biogenesis and fission processes. The protein kinase D family (PKD) has been previously described to enhance vesicle fission by modifying the lipid environment. PKD also phosphorylates the actin regulatory protein cortactin at S298 to impair synergistic actin polymerization.

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Post-traumatic cardiac dysfunction often occurs in multiply injured patients (ISS ≥ 16). Next to direct cardiac injury, post-traumatic cardiac dysfunction is mostly induced by the release of inflammatory biomarkers. One of these is the heparin-binding factor Midkine, which is elevated in humans after fracture, burn injury and traumatic spinal cord injury.

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Dysregulated intestinal epithelial apoptosis initiates gut injury, alters the intestinal barrier, and can facilitate bacterial translocation leading to a systemic inflammatory response syndrome (SIRS) and/or multi-organ dysfunction syndrome (MODS). A variety of gastrointestinal disorders, including inflammatory bowel disease, have been linked to intestinal apoptosis. Similarly, intestinal hyperpermeability and gut failure occur in critically ill patients, putting the gut at the center of SIRS pathology.

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Article Synopsis
  • Neutrophils play a crucial role in the innate immune response and the body's reaction to physical injuries, but their excessive presence at injury sites can lead to adverse effects.
  • The study reveals that protein kinase D (PKD) is essential for regulating neutrophil movement by influencing Cofilin and actin dynamics, particularly in response to chemotactic signals.
  • Inhibiting PKD with specific small molecules increases Cofilin activity and alters neutrophil flexibility, leading to reduced movement and a weaker response in models of trauma, suggesting that targeting PKD could help modulate neutrophil activity post-injury.
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Dependent on their cellular localization, Protein Kinase D (PKD) enzymes regulate different processes including Golgi transport, cell signaling and response to oxidative stress. The localization of PKD within cells is mediated by interaction with different lipid or protein binding partners. With the example of PKD2, we here show that phosphorylation events can also contribute to localization of subcellular pools of this kinase.

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We here report a novel function of the armadillo protein p0071 (also known as PKP4) during transport mediated by the KIF3 transport complex. Secretion of chromogranin A and matrix metallopeptidase 9 from pancreatic neuroendocrine tumor cells or pancreatic cancer cells, respectively, was substantially reduced following knockdown of p0071. Vesicle tracking indicated that there was impaired directional persistence of vesicle movement upon p0071 depletion.

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Objective: The generation of acinar and ductal cells from human pluripotent stem cells (PSCs) is a poorly studied process, although various diseases arise from this compartment.

Design: We designed a straightforward approach to direct human PSCs towards pancreatic organoids resembling acinar and ductal progeny.

Results: Extensive phenotyping of the organoids not only shows the appropriate marker profile but also ultrastructural, global gene expression and functional hallmarks of the human pancreas in the dish.

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Cell fate decisions and pluripotency, but also malignancy depend on networks of key transcriptional regulators. The T-box transcription factor TBX3 has been implicated in the regulation of embryonic stem cell self-renewal and cardiogenesis. We have recently discovered that forced TBX3 expression in embryonic stem cells promotes mesendoderm specification directly by activating key lineage specification factors and indirectly by enhancing paracrine NODAL signalling.

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Dynamic regulation of cell-cell adhesion by the coordinated formation and dissolution of E-cadherin-based adherens junctions is crucial for tissue homeostasis. The actin-binding protein cortactin interacts with E-cadherin and enables F-actin accumulation at adherens junctions. Here, we were interested to study the broader functional interactions of cortactin in adhesion complexes.

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Pluripotency represents a cell state comprising a fine-tuned pattern of transcription factor activity required for embryonic stem cell (ESC) self-renewal. TBX3 is the earliest expressed member of the T-box transcription factor family and is involved in maintenance and induction of pluripotency. Hence, TBX3 is believed to be a key member of the pluripotency circuitry, with loss of TBX3 coinciding with loss of pluripotency.

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Vesicle formation and fission are tightly regulated at the trans-Golgi network (TGN) during constitutive secretion. Two major protein families regulate these processes: members of the adenosyl-ribosylation factor family of small G-proteins (ARFs) and the protein kinase D (PKD) family of serine/threonine kinases. The functional relationship between these two key regulators of protein transport from the TGN so far is elusive.

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The protein kinase D isoenzymes PKD1/2/3 are prominent downstream targets of PKCs (Protein Kinase Cs) and phospholipase D in various biological systems. Recently, we identified PKD isoforms as novel mediators of tumour cell-endothelial cell communication, tumour cell motility and metastasis. Although PKD isoforms have been implicated in physiological/tumour angiogenesis, a role of PKDs during embryonic development, vasculogenesis and angiogenesis still remains elusive.

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