Biology subjects

Bosch, D.

Publications and source records attributed to Bosch, D..

5 recordsLinked to original sources

bioRxiv2026

RNA splicing factor mutations drive myeloid neoplasm oncogenesis through protein complex poisoning

RNA splicing factor mutations (SFmut) are founding oncogenic events which cause RNA splicing errors with unpredictable gene expression dynamics. Despite extensive transcriptomic studies, SFmut cancer-initiating mechanisms remain elusive. Among SFmut cancers, myeloid neoplasms (MN) alone offer a setting where true cancer-driving SFmut stem cells can be identified, namely the hematopoietic stem cell (HSC). Within a cohort of 62 MN patients and 20 healthy donors, we conducted long/short-read single-cell transcriptomics (10X-ONT, n = 21) and immunophenotype-resolved low-cell proteomics (pauciproteomics, n = 78) to resolve gene expression, RNA splicing and protein expression dynamics across healthy and SFmut MN hematopoiesis. During hematopoietic differentiation, SFmut RNA mis-splicing decouples proteotranscriptomic dynamics in a mutation-specific manner. Pauciproteomics defines the functional effects of SFmut RNA mis-splicing on the protein layer, identifying early-stage protein effects which poison entire functional protein complexes and progressively disrupt the proteome-wide network during cellular maturation. Importantly, this information could neither be resolved nor predicted by transcriptomic analyses. Finally, we functionally validate the proteome dynamics of HSC through induced pluripotent stem cell culture models of early hematopoietic differentiation, identifying candidate mechanisms for SFmut oncogenesis. Overall, these data elucidate SFmut MN disease biology with unprecedented granularity, defining the molecular consequences of SFmut RNA mis-splicing and offering a generalizable framework for cancer stem cell studies.

cancer biology↗

bioRxiv2025

Antisense oligonucleotides targeting Valosin-containing protein improve muscle pathology and molecular defects in cell and mouse models of multisystem proteinopathy.

Valosin-containing protein (VCP) related disease, also known as multisystem proteinopathy 1 (MSP1), is an autosomal dominant disease caused by gain-of-function pathogenic variants of the VCP gene. The disease is associated with inclusion body myopathy, early-onset Pagets disease of bone, frontotemporal dementia, and familial amyotrophic lateral sclerosis. There is currently no treatment for this progressive disease associated with early demise resulting from proximal limb girdle and respiratory muscle weakness. We hypothesize that regulating VCP hyperactivity to normal levels can reduce the disease pathology. In this study, we assessed the effect of antisense oligonucleotides (ASOs) specifically targeting the human VCP gene in the patient (R155H) iPSC-derived skeletal muscle progenitor cells (SMPCs). ASOs were well tolerated up to a concentration of 5 {micro}M, and significantly reduced VCP protein expression in the SMPCs by 48% (95% CI [39-56]). We also treated the transgenic mouse model of VCP disease with the overexpressed humanized VCP gene severe A232E pathogenic variant with weekly subcutaneous ASO injections starting from 6 months of age for 3 months. In the skeletal muscle of transgenic mice, ASOs resulted in 30% (95%CI [27-32]) knockdown of VCP protein compared to control ASO. The ASO-mediated reduction of VCP expression in muscle tissue was associated with improvement in autophagy flux and reduction in TDP-43 expression, hallmarks of VCP disease. In addition, ASO-treated VCP A232E mice showed improvements in functional tests of muscle strength, such as rotarod and inverted screen test compared to mice treated with control ASO. These results suggest that targeting VCP could be beneficial in preventing the progression of the VCP myopathy and hold promise for the treatment of patients with VCP MSP1.

molecular biology↗

bioRxiv2024

Macrovascular contributions to resting-state fMRI signals: A comparison between EPI and bSSFP at 9.4 Tesla

The draining-vein bias of T2*-weighted sequences, like gradient echo echo-planar imaging (GRE-EPI), can limit the spatial specificity of functional MRI (fMRI). The underlying extravascular signal changes increase with field strength (B0) and the perpendicularity of draining veins to the main axis of B0, and are therefore particularly problematic at ultra-high field (UHF). In contrast, simulations showed that T2-weighted sequences are less affected by the draining-vein bias, depending on the amount of rephasing of extravascular signal. As large pial veins on the cortical surface follow the cortical folding tightly, their orientation can be approximated by the cortical orientation to [Formula]. In our work, we compare the influence of the cortical orientation to [Formula] on the resting-state fMRI signal of three sequences aiming to understand their macrovascular contribution. While 2D GRE-EPI and 3D GRE-EPI (both T2*-weighted) showed a high dependence on the cortical orientation to [Formula], especially on the cortical surface, this was not the case for 3D balanced steady-state free precession (bSSFP) (T2/T1-weighted). Here, a slight increase of orientation dependence was shown in depths closest to WM. And while orientation dependence decreased with increased distance to the veins for both EPI sequences, no change in orientation dependence was observed in bSSFP. This indicates the low macrovascular contribution to the bSSFP signal, making it a promising sequence for layer fMRI at UHF.

neuroscience↗

bioRxiv2021

Gata2b haploinsufficiency causes aberrant transcriptional signatures in HSPCs resulting in myeloid and erythroid dysplasia in zebrafish

The transcription factor GATA2 has pivotal roles in hematopoiesis. Germline GATA2 mutations in patients result in GATA2 haploinsufficiency syndrome characterized by immunodeficiency, bone marrow failure, and predispositions to myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Clinical symptoms in GATA2 patients are diverse and mechanisms driving GATA2 related phenotypes largely unknown. To explore the impact of GATA2 haploinsufficiency on hematopoiesis, we generated a zebrafish model carrying a heterozygous mutation of gata2b (gata2b+/-), an orthologue of GATA2. Morphological analysis revealed myeloid and erythroid dysplasia in gata2b+/- kidney marrow (KM). single nucleus (sn)-ATAC-seq showed that the co-accessibility between the transcription start site (TSS) and a +3.5-4.1kb enhancer was more robust in gata2b+/- zebrafish HSPCs compared to wild type, increasing gata2b expression. This is suggestive of an auto-regulatory feedback mechanism, where gata2b expression remains at sufficient levels after the loss of a single allele to maintain the HSPC pool. As a result, gata2b+/- chromatin is also more accessible in the erythroid and myeloid lineage, causing several defects. scRNA-seq data revealed a differentiation delay in erythroid progenitors, hallmarked by downregulation of intrinsic signals like cytoskeletal transcripts, aberrant proliferative signatures, and downregulation of Gata1a, a master regulator of erythropoiesis, likely preceding erythroid dysplasia. This shows that the cell intrinsic compensatory mechanisms for the maintenance of normal levels of Gata2b to maintain HSPC integrity result in aberrant lineage differentiation and a preleukemia syndrome.

cancer biology↗

bioRxiv2019

Single cell transcriptome analysis reveals an essential role for Gata2b in hematopoietic lineage decisions in zebrafish

Hematopoietic stem cells (HSCs) are tightly controlled to keep a balance between myeloid and lymphoid cell differentiation. Gata2 is a pivotal hematopoietic transcription factor required for HSC generation and maintenance. We generated a zebrafish mutant for the mammalian Gata2 orthologue, gata2b. We found that in adult zebrafish, gata2b is required for both neutrophilic- and monocytic lineage differentiation. Single cell transcriptome analysis revealed that the myeloid defect present in Gata2b deficient zebrafish arise in the most immature hematopoietic stem and progenitor cell (HSPC) compartment and that this population is instead committed towards the lymphoid and erythroid lineage. Taken together, we find that Gata2b is vital for the fate choice between the myeloid and lymphoid lineages.

immunology↗