Publications by authors named "Geiger H"

The role of the immune system in regulating tissue stem cells remains poorly understood, as does the relationship between immune-mediated tissue damage and regeneration. Graft vs. host disease (GVHD) occurring after allogeneic bone marrow transplantation (allo-BMT) involves immune-mediated damage to the intestinal epithelium and its stem cell compartment.

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The distribution of biomolecules within cells changes upon aging and diseases. To quantitatively determine the spatial distribution of components inside cells, we built the user-friendly open-source 3D-cell-image analysis platform Cell Detection and Analysis of Intensity Lounge (CellDetail). The algorithm within CellDetail is based on the concept of the dipole moment.

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Article Synopsis
  • Genetic mosaicism refers to the existence of multiple cell types with different genetic makeups originating from a single fertilized egg, impacting various genetic diseases.
  • It can lead to a range of outcomes, from severe disorders that are typically fatal in non-mosaic forms to conditions with minor effects, which may still pose risks for passing on harmful genotypes.
  • The article will explore the different manifestations of mosaic genetic disease and review current methods of detection and its prevalence in the population.
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  • Advanced urothelial cancer displays significant genetic diversity and involves complex interactions between internal and external mutagens, which contributes to its deadly nature.
  • The study revealed that APOBEC3-induced mutations occur early during tumor development, while chemotherapy leads to a surge of later mutations, with both processes affecting the structure of extrachromosomal DNA.
  • Findings emphasized the role of circular ecDNA in the development of treatment resistance, specifically through CCND1 amplifications, highlighting key mechanisms that can inform future cancer therapies.
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Aged hematopoietic stem cells (HSCs) show reduced reconstitution potential, limiting their use in transplantation settings in the clinic. We demonstrate here that exposure of aged HSCs ex vivo to a pH of 6.9 instead of the commonly used pH of 7.

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Osteopenia and osteoporosis are common long-term complications of the cytotoxic conditioning regimen for hematopoietic stem cell transplantation (HSCT). We examined mesenchymal stem and progenitor cells (MSPCs), which include skeletal progenitors, from mice undergoing HSCT. Such MSPCs showed reduced fibroblastic colony-forming units frequency, increased DNA damage, and enhanced occurrence of cellular senescence, whereas there was a reduced bone volume in animals that underwent HSCT.

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The functional impact and cellular context of mosaic structural variants (mSVs) in normal tissues is understudied. Utilizing Strand-seq, we sequenced 1,133 single-cell genomes from 19 human donors of increasing age, and discovered the heterogeneous mSV landscapes of hematopoietic stem and progenitor cells. While mSVs are continuously acquired throughout life, expanded subclones in our cohort are confined to individuals >60.

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  • The study investigates how the Influenza A virus (IAV) affects human kidney cells, specifically looking at the mechanisms behind acute kidney injury (AKI) during IAV infection.
  • Researchers conducted various experiments, including infectivity assays and transcriptome/proteome analyses, revealing that IAV can replicate effectively in kidney cells.
  • Findings suggest that regulated cell death plays a key role in kidney damage due to IAV, highlighting potential targets for treatment to mitigate kidney-related complications.
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Early-life stress has been linked to multiple neurodevelopmental and neuropsychiatric deficits. Our previous studies have linked maternal presence/absence from the nest in developing rat pups to changes in prefrontal cortex (PFC) activity. Furthermore, we have shown that these changes are modulated by serotonergic signaling.

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Article Synopsis
  • Marburg virus causes Marburg virus disease (MVD), a severe hemorrhagic fever with a high fatality rate, and can lead to acute kidney injury, though the exact mechanisms remain unclear.
  • Studies show viral proteins in nephron cells, particularly in proximal tubular cells (PTC), indicating the virus might contribute to kidney damage in MVD.
  • Research involving human PTC revealed that while the virus replicates significantly, it doesn't cause immediate cell death, instead leading to downregulation of crucial genes for kidney function and upregulation of inflammatory response genes.
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Article Synopsis
  • Aging leads to weakened blood and immune systems in older adults, making them more prone to health issues like infections and tumors.
  • Hematopoietic stem cells lose their ability to produce blood effectively and show a preference for myeloid cells, along with mitochondrial dysfunction.
  • Urolithin A, a mitochondrial modulator, can restore the blood-producing capability of aging stem cells and enhance immune functions, suggesting it may help reverse aging effects in these systems.
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Background: Cellular senescence is the main cause of skin and organ aging and is associated with a wide range of aging-related diseases.

Objectives: To understand which senolytics, senomorphics, and cell-based therapies have been developed to alleviate and even rejuvenate skin aging and reduce cellular senescence.

Methods: Basic literature for the mode of action of senolytics and senomorphics and their clinical perspectives in daily routine are discussed.

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Intraosseous hibernoma (IOH) mimicking osseous metastasis is a rare and little-known pitfall in nuclear medicine and radiology. Referring to a clinical case, we show imaging features in FDG-PET and CT as well as pathological characteristics and discuss MRI and differential diagnoses. A 73-year-old woman was assigned for an FDG-PET/CT examination after the incidental finding of a suspicious pulmonary nodule.

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Upon ex vivo culture, hematopoietic stem cells (HSCs) quickly lose potential and differentiate into progenitors. The identification of culture conditions that maintain the potential of HSCs ex vivo is therefore of high clinical interest. Here, we demonstrate that the potential of murine and human HSCs is maintained when cultivated for 2 days ex vivo at a pH of 6.

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Inflammation is intimately involved in the pathogenesis of diabetic kidney disease. Inhibition of SGLT-2 by a specific class of drugs, gliflozins, has been shown to reduce inflammation and attenuate the progression of diabetic nephropathy, in addition to its main effect of inhibiting renal glucose reabsorption. We used highly purified human renal proximal tubular epithelial cells (PTCs) as an in vitro model to study the cellular response to a diabetic (high glucose) and inflammatory (cytokines) microenvironment and the effect of gliflozins.

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The 2021 La Palma eruption provided an unpreceded opportunity to test the relationship between earthquake hypocenters and the location of magma reservoirs. We performed density measurements on CO-rich fluid inclusions (FIs) hosted in olivine crystals that are highly sensitive to pressure via calibrated Raman spectroscopy. This technique can revolutionize our knowledge of magma storage and transport during an ongoing eruption, given that it can produce precise magma storage depth constraints in near real time with minimal sample preparation.

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As a transcription factor in the RUNT domain core-binding factor family, RUNX1 is crucial in multiple stages of hematopoiesis, and its mutation can cause familial platelet disorder with a predisposition to acute myeloid leukemia. Previous work has established that RUNX1 is involved in the maturation of megakaryocytes (MKs) and the production of platelets. Recent studies have shown that there exists a subpopulation of hematopoietic stem cells (HSCs) with relatively high expression of von Willebrand factor and CD41 at the apex of the HSC hierarchy, termed MK-HSCs, which can give rise to MKs without going through the traditional differentiation trajectory from HSC via MPP (multipotent progenitors) and MEP (megakaryocyte-erythroid progenitor).

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One goal of regenerative medicine is to rejuvenate tissues and extend lifespan by restoring the function of endogenous aged stem cells. However, evidence that somatic stem cells can be targeted in vivo to extend lifespan is still lacking. Here, we demonstrate that after a short systemic treatment with a specific inhibitor of the small RhoGTPase Cdc42 (CASIN), transplanting aged hematopoietic stem cells (HSCs) from treated mice is sufficient to extend the healthspan and lifespan of aged immunocompromised mice without additional treatment.

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Surgical aortic valve replacement (SAVR) in kidney transplant recipients (KTR) is associated with high morbidity and mortality, and an increased risk of postoperative graft failure potentially leading to graft loss. Transcatheter aortic valve implantation (TAVI) emerged as an alternative in high-risk patients. However, data on TAVI in kidney transplant recipients are limited.

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Quantitative 3D imaging of organ-wide cellular and subcellular components is central for revealing and understanding complex interactions between stem cells and their microenvironment. Here, we present a gentle but fast whole-mount immunofluorescence staining protocol for 3D confocal microscopy (iFAST3D) that preserves the 3D structure of the entire tissue and that of subcellular structures with high fidelity. The iFAST3D protocol enables reproducible and high-resolution 3D imaging of stem cells and various niche components for many mouse organs and tissues.

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Thoracic trauma is a major cause of mortality due to the associated inflammatory acute respiratory distress syndrome and morbidity due to impaired tissue regeneration. Trauma-induced lung inflammation is characterized by the early recruitment of cells with pro- or anti-inflammatory activity to the lung. Therapeutic interventions reducing the level of tissue inflammation may result in decreased tissue damage and improved healing and recovery.

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Heterogeneity is a hallmark of cancer. The advent of single-cell technologies has helped uncover heterogeneity in a high-throughput manner in different cancers across varied contexts. Here we apply single-cell sequencing technologies to reveal inherent heterogeneity in assumptively monoclonal pancreatic cancer (PDAC) cell lines and patient-derived organoids (PDOs).

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Retromer is a heteropentameric complex that plays a specialized role in endosomal protein sorting and trafficking. Here, we report a reduction in the retromer proteins-vacuolar protein sorting 35 (VPS35), VPS26A, and VPS29-in patients with amyotrophic lateral sclerosis (ALS) and in the ALS model provided by transgenic (Tg) mice expressing the mutant superoxide dismutase-1 G93A. These changes are accompanied by a reduction of levels of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor subunit GluA1, a proxy of retromer function, in spinal cords from Tg SOD1 mice.

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