Biology subjects

Nevo, N.

Publications and source records attributed to Nevo, N..

4 recordsLinked to original sources

bioRxiv2025

Systems level analysis of B-cell development identifies BDNF as a driver for human B lymphopoiesis

B-cell aplasia is a major consequence of aging, chemotherapy, and B-cell-depleting immunotherapies, compromising immune protection against infections, cancer, and vaccines. Yet, unlike the myeloid and erythroid lineages, no strategy exists to accelerate human B-cell reconstitution. Here, we used an integrative systems biology approach to identify regulators of human B lymphopoiesis in the bone marrow (BM) microenvironment. By combining single-cell transcriptomic analysis of human BM with intercellular communication mapping, we generated an initial set of candidate factors predicted to act on developing B cells. To distinguish biologically meaningful putative regulators from a broad candidate space, we further intersected these findings with orthogonal human datasets capturing age-impaired B lymphopoiesis and protein dynamics associated with B-cell depletion and reconstitution. This convergent prioritization strategy highlighted a focused set of putative regulators, among which brain-derived neurotrophic factor (BDNF) emerged repeatedly as a top putative regulator. Functional interrogation in progenitor BM cells showed that several prioritized putative regulators induced transcriptional programs linked to early immune development, with BDNF consistently promoting pathways associated with B-cell differentiation. Importantly, in a human in vitro BM co-culture system, BDNF enhanced the differentiation of CD34+ hematopoietic progenitors into CD19+ progenitor B cells. Together, these findings identify BDNF as a previously unrecognized regulator of early human B lymphopoiesis and establish a general framework for uncovering functional hematopoietic regulators by integrating single-cell analysis with complementary biological and clinical signals. This approach may support future strategies to improve immune reconstitution in settings of prolonged B-cell depletion.

systems biology↗

bioRxiv2021

Homosalate boosts the release of tumor-derived Extracellular Vesicles with anti-anoikis properties

Eukaryotic cells, including cancer cells, secrete highly heterogeneous populations of extracellular vesicles (EVs). EVs could have different subcellular origin, composition and functional properties, but tools to distinguish between EV subtypes are scarce. Here, we tagged CD63- or CD9-positive EVs secreted by triple negative breast cancer cells with Nanoluciferase enzyme, to set-up a miniaturized method to quantify secretion of these two EV subtypes directly in the supernatant of cells. We performed a cell-based high-content screening to identify clinically-approved drugs able to affect EV secretion. One of the identified hits is Homosalate, an anti-inflammatory drug found in sunscreens which robustly increased EVs release. Comparing EVs induced by Homosalate with those induced by Bafilomycin A1, we discovered that: 1) the two drugs act on EVs generated in distinct subcellular compartments and 2) EVs released upon treatment with Homosalate, but not with Bafilomycin A1, conferred anti-anoikis properties to another recipient tumor cell line. In conclusion, we identified a new drug modifying EV release and demonstrated that under influence of different drugs, triple negative breast cancer cells release EV subpopulations from different subcellular origins harboring distinct functional properties.

cell biology↗

bioRxiv2020

Specificities of exosome versus small ectosome secretion revealed by live intracellulartracking and synchronized extracellular vesicle release of CD9 and CD63

Despite their important and multiple roles in intercellular communications, the different populations of extracellular vesicles (EVs) and their secretion mechanisms are not fully characterized yet. In particular, how and to what extent EVs form either as intraluminal vesicles of endocytic compartments (exosomes), or at the plasma membrane (ectosomes) remains unclear. We followed in HeLa cells the intracellular trafficking of the EV markers CD9 and CD63 from the endoplasmic reticulum to their residency compartment and identified transient co-localization both at the plasma membrane (PM) and in endosomes, before they finally segregate. CD9 was more abundantly released in EVs than CD63. However, when forcing expression of CD63 at the PM, by mutating its lysosome-addressing motive, its secretion in EVs was increased. Thus, in HeLa cells, small ectosomes are more prominently released than exosomes. By comparative proteomic analysis, we identified a few surface proteins likely specific of either exosomes (e.g. LAMP1) or ectosomes (e.g. BSG, SLC3A2), based on their known intracellular location in lysosomes or the PM, and on the different effects on their release of Bafilomycin A1, a drug that neutralizes endosomal pH. Our work sets the path for molecular and functional discrimination of exosomes and small ectosomes in any cell type.

cell biology↗

bioRxiv2018

Cystinosin regulates kidney inflammation through its interaction with galectin-3

Inflammation is implicated in the pathogenesis of many disorders. Here, we show that cystinosin, protein defective in the lysosomal storage disorder cystinosis, is a critical regulator of galectin-3 during inflammation. Cystinosis is a lysosomal storage disorder and despite ubiquitous expression of cystinosin, kidney is the primary organ to be impacted by the disease. Here, we show that cystinosin interacts with galectin-3 and enhances its lysosomal localization and degradation. Galectin-3 is also found overexpressed in the kidney of the mouse model of cystinosis, Ctns-/-mice. Absence of galectin-3 in Ctns-/- mice led to a better renal function and structure, and decreased macrophage/monocyte infiltration in the kidney. Finally, galectin-3 interacts with a protein implicated in the recruitment of monocytes and macrophages during inflammation, Monocyte Chemoattractant Protein-1 (MCP1), that was found increased in the serum of Ctns-/- mice. These findings highlight a new role of cystinosin and galectin-3 interaction in inflammation, providing a mechanistic explanation for kidney disease pathogenesis in cystinosis, which may lead to the identification of new drug targets to delay its progression.

molecular biology↗