Biology subjects

Pincez, T.

Publications and source records attributed to Pincez, T..

2 recordsLinked to original sources

bioRxiv2026

Inhibition of macrophage neuraminidase 1 protects against immune thrombocytopenia by limiting platelet clearance

Immune thrombocytopenia purpura (ITP) is an autoimmune disorder characterized by a reduction in circulating platelet levels, primarily due to generation of autoantibodies to platelet surface antigens followed by their spleen macrophage-mediated clearance. Emerging evidence implicates neuraminidase (sialidase) enzymes including neuraminidase 1 (NEU1) in platelet clearance and ITP severity; however, the underlying cellular mechanisms remain unknown. Using tissue-specific NEU1 knockout mouse models, we studied the contribution of platelet and macrophage NEU1 to ITP pathogenesis and evaluated whether pharmacological inhibition of NEU1 could preserve platelet counts in a murine ITP model. Constitutive and macrophage-specific, but not platelet-specific, NEU1 knockout mice showed a protection against reduction of platelet counts in the passive ITP model suggesting that macrophage, but not platelet, NEU1 promotes platelet clearance. Genetic deletion or pharmacological blockade of macrophage NEU1 also reduced platelet phagocytosis by cultured macrophages in vitro. The selective NEU1 inhibitor CG33301 protected mice against anti-CD41a antibody-induced thrombocytopenia and showed a higher efficacy compared to pan neuraminidase inhibitor oseltamivir phosphate. Our results demonstrate that the macrophage pool of NEU1 plays a central role in platelet clearance by splenocytes during ITP by activating their phagocytosis and suggest that selective NEU1 inhibition may be a promising therapeutic strategy for this disease.

biochemistry↗

bioRxiv2025

Pooled CRISPR screens identify genes and non-coding genomic regions that regulate red blood cell density

Genome-wide association studies have identified >1,000 loci associated with clinically important red blood cell (RBC) traits, such as hemoglobin concentration and cell volume. However, few of these associations have been characterized at the molecular level such that most causal genes and variants remain elusive. Here, we performed pooled CRISPR screens in an erythroid cell line to identify genes and regulatory non-coding sequences that control RBC density. We perturbed 556 candidate genes and genomic sequences near 2,114 GWAS variants. We used a density gradient to detect the impact of these CRISPR perturbations on cell density. After validation, we found 17 genes and 13 regions near GWAS variants that regulate cell density. Some of these genes have previously been implicated in RBC biology (e.g. ATP2B4, CCND3, EPOR) although many are novel (e.g. CHTF8, CTU2, DNASE2). We confirmed that deletions in the osmotic stress response kinase gene OXSR1 increase cell density, and a phosphoproteome analysis in OXSR1-depleted cells indicated that this phenotype is accompanied with a dephosphorylation of the upstream kinase WNK1 and the downstream target KCC3 (SLC12A6). We also combined CRISPR perturbations and RNA-sequencing to show how a non-coding genomic sequence near rs13255015 regulates the expression of the transcription factor ZFAT in cis and SLC4A1 in trans. SLC4A1 encodes Band3, a known regulator of RBC hydration and volume. Our results suggest experimental strategies to characterize GWAS findings and provide new molecular insights into the regulation of complex RBC traits.

genomics↗