Biology subjects

Gonzalez Anton, S.

Publications and source records attributed to Gonzalez Anton, S..

7 recordsLinked to original sources

bioRxiv2026

Intravital microscopy and statistical image analysis of early engraftment of haematopoietic stem cells reveal dynamic and evolving cellular behaviours linked to progressive differentiation.

Haematopoietic stem cells (HSCs) have long been used in the clinic for bone marrow transplantation applications, critical for the survival of an increasingly wide range of patients with haematological, oncological and immunological pathologies. Despite this, little is known about the mechanisms through which relatively few stem cells are able to regenerate the entire haematopoietic tissue of transplant recipients. To gain insights on this biological process, we used intravital microscopy of calvarium bone marrow, collecting tissue-wide images and a total of 850 hours of tracks of engrafting haematopoietic stem and progenitor cells from 24 hours to 8 days following injection in lethally irradiated recipients. Analysis of the data revealed that regenerating HSCs and their immediate progeny are highly dynamic, migrating through the parenchyma at both the microscopic and near-macroscopic scales, i.e. within and in-and-out of fields of view. HSC-derived cell clusters, expanded locally between day 2 and day 4 post-transplant, leading to patches of densely populated bone marrow by day 8. Single cell level analysis highlighted increasingly heterogenous cellular behaviours over time. Track clustering based on migration and niche interaction parameters combined with post-tracking whole mount immunostaining revealed that persistence in the vicinity of nestin-GFP perivascular cells and relatively slow movement correlated with stemness, while more heterogeneous niche interactions coupled with slowest or faster migration correlated with differentiation, validated through flow cytometry analysis and functional studies. The findings presented here shed light on the fundamental principles driving haematopoietic regeneration in transplantation settings.

developmental biology↗

bioRxiv2026

Multi-omics profiling links epigenetic and lncRNA changes to early human endochondral ossification priming

Differentiation programs remain incompletely understood across stem cell types, including for human bone marrow mesenchymal stromal/stem (BM-MSCs) cells, a heterogenous population orchestrating bone formation and establishing a functional hematopoietic niche in the bone marrow. BM-MSCs form and repair bone through the evolutionarily conserved process of endochondral ossification (EO), initiated by deposition of a transient cartilage template subsequently remodeled into bone and bone marrow tissues. Despite their considerable potential for skeletal regeneration, the early molecular and cellular events underlying BM-MSCs commitment to EO remain elusive. To overcome donor dependent variability in chondrogenic potential that limits mechanistic studies, we here exploit OssiGel as a potent chondro-inductive extracellular matrix offering robust recapitulation of EO by BM-MSCs. Through multi-omics profiling of OssiGel-primed BM-MSCs, we identify rapid chromatin remodeling at chondrogenic loci as concomitant for lineage commitment. The emergence of a chondro-progenitor population is detected as early as 3 days in vivo and correlates with successful EO recapitulation. Mechanistically, we identify LINC02511 as novel enhancer-associated element involved in the onset of EO. We confirm presence of LINC02511 in human skeletal atlases, and its CRISPR-mediated silencing significantly impaired EO. By integrating human tissue engineering strategies with single cell multi-omics profiling, our study provides a framework for deciphering BM-MSCs fate decisions, highlighting the role of enhancer and non-coding elements as key determinants of early lineage specification. These findings advance our understanding of BM-MSCs biology and will prompt their translational exploitation in regenerative medicine.

cell biology↗

bioRxiv2026

Engineering autologous ossicles for the personalized modeling of acute myeloid leukemia

Acute Myeloid Leukemia (AML) is the most lethal hematological malignancy in adults and is characterized by significant genetic and cytogenetic heterogeneity. This diversity drives substantial patient-to-patient variability in disease progression and therapeutic response. Increasing evidence indicates that bone marrow mesenchymal stem/stromal cells (MSCs) play a critical role in AML emergence, evolution and treatment resistance. However, progress in the field is challenged by the lack of experimental models supporting sustained AML survival while faithfully recapitulating the human bone marrow niche. Humanized ossicles (hOss) have recently emerged as ectopic human bone/bone marrow microenvironments composed of MSCs and hematopoietic elements, enabling improved AML engraftment in vivo. Nonetheless, those models typically exploit healthy MSCs largely because primary patient-derived cells exhibit diminished ossification potential. Here, we introduce OssiGel, a novel engineered human cartilage extracellular matrix produced by a mesenchymal cell line. We hypothesized that combining OssiGel with primary MSCs would enable the robust formation of hOss in healthy and malignant settings. We report that OssiGel supports fast and reproducible formation of hOss through endochondral ossification using MSCs isolated from both healthy and AML bone marrow samples. Within hOss, AML-MSCs were shown to persist long-term and to generate a human stromal microenvironment supporting the establishment of autologous AML hematopoietic cells, enabling the generation of autologous (autologOss). Single-cell RNA sequencing (scRNA-seq) revealed that autologOss recapitulate the majority of the AML blood populations observed in the corresponding patient bone marrow samples. Moreover, proof-of-concept sequencing of AML-MSCs from autologOss allowed predictive interrogation of interactions with leukemic populations and revealed the acquisition of an inflammatory-like phenotype, characteristic of AML. Taken together, our study establishes OssiGel as a novel platform for the robust engineering of autologous ossicles from AML patient samples. This provides a relevant tool to decipher patient-specific cellular interactions and drug responses, with potential translational value to broad hematological malignancies.

bioengineering↗

bioRxiv2025

Pre-clinical validation of in vitro engineered but cell-free human tissue grafts for skeletal regeneration

Tissue engineering strategies predominantly consist of the autologous generation of living substitutes capable of restoring damaged body parts. Persisting challenges with patient-specific approaches include inconsistent performance, high costs and delayed graft availability. Towards developing a one-for-all solution, a more attractive paradigm lies in the exploitation of dedicated cell lines for the fabrication of human tissue grafts. Following decellularization, this new class of biomaterials relies on the sole extracellular matrix and embedded growth factors instructing endogenous repair. This conceptual approach was previously validated using a custom mesenchymal line for the manufacturing of human cartilage, exhibiting remarkable osteoinductive capacity following lyophilization. Key missing criteria to envision clinical translation include proper decellularization as well as stringent assessment of both immunogenicity and regenerative performance. Here, we report the engineering and subsequent decellularization of human cartilage tissue with minimal matrix impairment. Ectopic evaluation in immunocompetent and immunocompromised animals reveal preservation of osteoinductivity predicted by macrophage kinetic of polarization. By establishing in vitro human allogeneic co-culture models, we evidenced the immuno-evasive properties of cell-free human cartilages, controlling macrophages and dendritic cells maturation as well as T cell activation. Lastly, regenerative performance was stringently assessed in an immunocompetent rat orthotopic model whereby decellularized human cartilage grafts achieved morphological and mechanical restoration of all critical-sized femoral defects. Taken together, our study compiles robust safety and efficacy pre-requisites prompting a first-in-human trial for engineered and decellularized human tissue grafts.

bioengineering↗

bioRxiv2024

Differential responses and recovery dynamics of HSPC populations following Plasmodium chabaudi infection.

Severe infections such as malaria are on the rise worldwide, driven by both climate change and increasing drug-resistance. It is therefore paramount that we better understand how the hosts organism responds to severe infection. Hematopoiesis is particularly of interest in this context because hematopoietic stem and progenitor cells (HSPCs) maintain the turnover of all blood cells, including all immune cells. Severe infections have been widely acknowledged to affecting HSPCs, however this disruption has been mainly studied during the acute phase, and the process and level of HSPC recovery remains understudied. Using a self-resolving model of natural rodent malaria, infection by Plasmodium chabaudi, here we systematically assess HSPCs acute response and recovery upon pathogen clearance. We demonstrate that during the acute phase of infection the most quiescent and functional stem cells are depleted, multipotent progenitor compartments are drastically enlarged, and oligopotent progenitors virtually disappear, underpinned by dramatic, population-specific and sometimes unexpected changes in proliferation rates. HSPC populations return to homeostatic size and proliferation rate again through specific patterns of recovery. Overall, our data demonstrate that HSPC populations adopt different responses to cope with severe infection and suggest that the ability to adjust proliferative capacity becomes more restricted as differentiation progresses.

developmental biology↗

bioRxiv2021

Heterogeneous run-and-tumble motion accounts for transient non-Gaussian super-diffusion in haematopoietic multi-potent progenitor cells

Multi-potent progenitor (MPP) cells act as a key intermediary step between haematopoietic stem cells and the entirety of the mature blood cell system. Their eventual fate determination is thought to be achieved through migration in and out of spatially distinct niches. Here we first analyze statistically MPP cell trajectory data obtained from a series of long time-course 3D in-vivo imaging experiments on irradiated mouse calvaria, and report that MPPs display transient super-diffusion with apparent non-Gaussian displacement distributions. Second, we explain these experimental findings using a run-and-tumble model of cell motion which incorporates the observed dynamical heterogeneity of the MPPs. Third, we use our model to extrapolate the dynamics to time-periods currently inaccessible experimentally, which enables us to quantitatively estimate the time and length scales at which super-diffusion transitions to Fickian diffusion. Our work sheds light on the potential importance of motility in early haematopoietic progenitor function.

biophysics↗

bioRxiv2020

The metalloproteinase inhibitor Prinomastat reduces AML growth,prevents stem cell loss and improves chemotherapy effectiveness

Acute myeloid leukemia (AML) is a blood cancer of the myeloid lineage. Its prognosis remains poor, highlighting the need for new therapeutic and precision medicine approaches. AML symptoms often include cytopenias, linked to loss of healthy hematopoietic stem and progenitor cells (HSPCs). The mechanism behind HSPC decline is complex and still poorly understood. Here, intravital microscopy (IVM) of a well-established experimental model of AML allows direct observation of the interactions between healthy and malignant cells in the bone marrow (BM), suggesting that physical dislodgment of healthy cells by AML through damaged vasculature may play an important role. Numerous human leukemia types, particularly MLL-AF9 samples, show high expression levels of multiple matrix metalloproteinases (MMPs). Therefore, we evaluate the therapeutic potential of the MMP inhibitor (MMPI) prinomastat. IVM analyses of treated mice reveal reduced vascular permeability and healthy cell clusters in circulation, and lower AML cell speed. Furthermore, treated mice have decreased BM infiltration, increased retention of healthy HSPCs in the BM and increased survival following chemotherapy. Overall, our results suggest that MMPIs could be a promising complementary therapy to reduce AML growth and limit the loss of HSPC and BM vascular damage caused by MLL-AF9 and possibly other AML subtypes.

cancer biology↗