Biology subjects

Ellinghaus, A.

Publications and source records attributed to Ellinghaus, A..

4 recordsLinked to original sources

bioRxiv2026

iPS-CNM: an iPSC collection generated by base editing for centronuclear myopathy

Centronuclear myopathy (CNM) is a rare form of inherited diseases often caused by single base mutations. Modelling CNM is challenging due to the diversity of CNM mutations and genetic background of individual patient. To address this, we used base editing to introduce CNM mutations into an induced pluripotent stem cell (iPSC) line from a healthy donor, generating a collection of iPSC lines (iPS-CNM) carrying distinct CNM mutations. We found that the efficiency of base editing depended critically on selecting base editor (BE) variants and the target sequences. Optimization using different BE variant and sgRNA pair was required for each target site. Moreover, whole genome sequencing (WGS) was performed to confirm on-targets and detect off-targets in order to select iPSC clones for the collection. Our findings highlight the feasibility of base editing for generating an iPSC collection from one parental iPSC line combined with thorough evaluation of rare off-targets using WGS.

genetics↗

bioRxiv2025

The cortical microenvironment drives early immune organization and controls early osteoclastogenesis in bone healing

Bone regeneration is a complex, tightly-regulated process involving coordinated interactions of immune and stromal cells. Early phases of healing rely on the timely clearance of debris, a task primarily carried out by macrophages and osteoclasts. However, the sequence of events leading to the presence of osteoclasts at the fracture site and how this is shaped by local tissue microenvironments remains poorly understood, particularly at single-cell and spatial resolution. Using single-cell RNA sequencing and multi-epitope ligand cartography, we mapped the spatial organization of distinct cell compartments engaged in early fracture healing in both young and aged mice at the start of healing. Surprisingly, we found that young mice exhibited an increased presence of activated osteoclasts at day 7, concentrated within the cortical niche. This compartment was also characterized by a spatially restricted immune response with a selective accumulation of distinct macrophage types jointly interacting with neutrophils and stromal cells. This raised the possibility that local cell organization influences osteoclast precursor differentiation. We identified a distinct Spp1hi macrophage subset restricted to the cortex, which acted as a transitional precursor population giving rise to osteoclasts. Neutrophils preceded this Spp1hi macrophage accumulation and may promote their recruitment through chemotactic signaling. This coordination was less pronounced in aged mice despite preserved transcriptional states. In parallel, stromal cells in young animals displayed higher expression of essential niche factors further supporting local osteoclastogenesis at the cortex. Together, our findings identify distinct macrophage precursors and reveal early, cortex-specific niche activity supporting osteoclastogenesis. This provides a new framework for understanding the initiation of spatial immune-stromal interactions for the early stages of regeneration.

immunology↗

bioRxiv2023

From breast cancer cell homing to the onset of early bone metastasis: dynamic bone (re)modeling as a driver of osteolytic disease

Breast cancer often metastasizes to bone causing osteolytic lesions. Structural and biophysical changes are rarely studied, yet are hypothesized to influence metastatic progression. Here, we developed a mouse model of early bone metastasis and multimodal 3D imaging to quantify cancer cell homing, dynamic bone (re)modeling and onset of bone metastasis. Using 3D light sheet fluorescence microscopy, we show eGFP+ cancer cells and small clusters in 3D (intact) bones. We detect early bone lesions using time-lapse in vivo microCT and reveal altered bone (re)modeling in absence of detectable lesions. With a new microCT image analysis tool, we detect and track the growth of early bone lesions over time. We show that cancer cells home in all bone compartments, while osteolytic lesions are only detected in the metaphysis, a region of high (re)modeling. Our study provides novel insights of dynamic bone (re)modeling as a driver during the early phase of metastasis.

bioengineering↗

bioRxiv2020

In vivo validation of spray-dried mesoporous bioactive glass microspheres acting as prolonged local release systems for BMP-2 to induce bone regeneration

Despite years of diligent research in fracture healing, an unmet clinical need for safe and effective pharmacological treatments to improve bone regeneration persists with 10 - 20 % of fracture cases exhibiting impaired healing. Bone morphogenetic protein-2 (BMP-2) is a known key mediator of physiological bone regeneration and is clinically approved for selected musculoskeletal interventions. Yet, broad usage of this growth factor is impeded due to side effects that are majorly evoked by high dosages and burst release kinetics. In this study, mesoporous bioactive glass microspheres (MBGs) produced by an aerosol assisted spray-drying, scalable process were found to be biocompatible and to induce a pro-osteogenic response on human MSCs in vitro. Loading of the MBGs with BMP-2 resulted in prolonged, low-dose BMP-2 release without affecting the material features. In a pre-clinical rodent model, BMP-2 loaded MBGs significantly enhanced bone formation and influenced the microarchitecture of newly formed bone. The MBG carriers alone performed equal to the untreated (empty) control in most parameters tested, while additionally exerting mild pro-angiogenic effects. Using MBGs as a biocompatible, pro-regenerative carrier for local and sustained low dose BMP-2 release could limit side effects, thus enabling a safer usage of BMP-2 as a potent pro-osteogenic growth factor.

cell biology↗