Biology subjects

Kang, Y.-A.

Publications and source records attributed to Kang, Y.-A..

4 recordsLinked to original sources

bioRxiv2026

TNFα drives platelet hyperreactivity and thromboinflammation through regulation of hematopoietic stem and progenitor cells.

TNF is the primary age-related cytokine responsible for hyperreactive platelet formation. In mouse models, increased TNF induced abnormal megakaryocyte development and platelet activity. Here, we extend these findings to demonstrate that TNF drives this thrombotic phenotype through expansion of the hematopoietic stem and progenitor cell (HSPCs) compartment. Using HSPC-specific TNF receptor labeling and single cell RNA sequencing, we found that TNF receptors are absent from megakaryocytes and their progenitors (MkPs) indicating that TNF does not directly act on these cells. Chronic TNF exposure expanded HSPCs in the bone marrow and extramedullary tissues - and these expanded HSPCs retained functional repopulation capacity. Using species-specificity TNF receptor activation, we further demonstrate that TNFR1 signaling is sufficient to induce platelet hyperreactivity independent of HSPC expansion. Unlike emergency hematopoiesis, chronic TNF promoted megakaryopoiesis through the canonical hematopoietic hierarchy as demonstrated by lineage-tracing studies. Mechanistically, chronic TNF induced a distinct transcriptional program in single cell RNA sequencing of HSPCs and megakaryocytes. Together, these findings establish that chronic TNF promotes hyperreactive platelet formation not through direct effects on megakaryocytes or MkPs but by expanding and transcriptionally reprogramming HSPCs, thereby imprinting a TNF dependent program that persists through megakaryopoiesis and ultimately produces hyperreactive platelets.

cell biology↗

bioRxiv2025

ARID1A and ARID1B safeguard B cell identity, prevent myeloid transformation and expose therapeutic vulnerabilities in lymphoma

Chromatin remodeling by the SWI/SNF complex is essential for hematopoietic lineage commitment and differentiation. While core subunits ARID1A and ARID1B are frequently mutated in B cell malignancies, their functions remain unclear. Recent work established ARID1A- dependent functions within germinal center (GC) B cells, but its role during early B cell development, and whether its homolog, ARID1B, contributes distinct or compensatory roles at steady state or during transformation, remain unknown. Here, we used CD19-Cre-mediated deletion initiated at the pro-B cell stage to investigate their role in B cell development in vivo. Loss of either gene partially blocked B cell differentiation, reducing immature/recirculating B cell output, and impaired germinal center formation following antigen challenge. Combined deletion further reduced peripheral B cells, shortened survival, and resulted in aggressive leukemia. Unexpectedly, the malignancy was of myeloid origin and arose from a subset of CD19-expressing multipotent progenitors (MPPs). Arid1a/Arid1b-deficient MPPs exhibited abnormal expansion, reduced colony formation, and dysregulation of stemness and lineage-priming programs, including diminished CBFA2T3 (ETO2) and Fli1 signatures. In established B cell lymphoma cells in vitro, double ARID1A/ARID1B loss modestly affected cell growth, whereas loss of ARID1A increased sensitivity to EZH2 inhibition. Transcriptomic analyses revealed alterations in cell adhesion/migration pathways, cytokine-receptor interactions and DNA repair mechanisms. Collectively, these findings reveal stage-specific and compensatory roles for ARID1A and ARID1B in B cell development, uncover a mechanism by which SWI/SNF loss in MPPs redirects transformation towards myeloid leukemia, and suggest context-dependent therapeutic vulnerabilities.

cancer biology↗

bioRxiv2025

Unfolded protein response signaling promotes myeloid cell production and cooperates with oncogenic mutation

Unfolded protein response (UPR) promotes protein homeostasis under endoplasmic reticulum stress. UPR signaling has numerous functions in metabolism, cancer, immunology, and neurodegenerative diseases. Recent studies also showed that UPR signaling has important roles in hematopoietic stem and progenitor cell biology. However, whether UPR signaling regulates hematopoietic lineage fate decision remains elusive. Here, we found that Fc{gamma}R- MPP3 generates erythroid lineage and Jak2V617F mutation leads to overproduction of erythroid cells by expanding Fc{gamma}R- MPP3. We showed that UPR signaling increases myeloid cell production through promoting Fc{gamma}R- MPP3 transition to granulocyte/macrophage progenitor producing Fc{gamma}R+ MPP3 at the expense of erythroid lineage via the XBP1 pathway. Under a disease condition, UPR signaling cooperates with Jak2V617F mutation and exacerbates disease phenotype in a mouse model of polycythemia vera (PV) through the ATF4 pathway. Activation of UPR signaling also increased myeloid output in healthy donor bone marrow MPP cells while skewing the output towards erythroid lineage in PV patient bone marrow MPP cells. Together, our results identify a novel function of UPR signaling in hematopoietic lineage specification and provide critical insights into targeting UPR signaling in hematological malignancies. Key pointsO_LIUPR signaling promotes myeloid cell production at the expense of erythroid lineage in steady state. C_LIO_LIUPR signaling collaborates with Jak2V617F mutation and increases red blood cell production. C_LI

cell biology↗

bioRxiv2021

Secretory MPP3 reinforce myeloid differentiation trajectory and amplify myeloid cell production

Recent lineage tracing analyses revealed multipotent progenitors (MPP) to be major functional contributors to steady-state hematopoiesis (1-6). However, we are still lacking a precise resolution of myeloid differentiation trajectories and cellular heterogeneity in MPPs. Here, we found that myeloid-biased MPP3 (2, 3) are functionally and molecularly heterogeneous, with a distinct subset of myeloid-primed secretory cells with high endoplasmic reticulum (ER) volume and Fc{gamma}R expression. We show that Fc{gamma}R+/ERhigh MPP3 are a transitional population for rapid production of granulocyte/macrophage progenitors (GMP), which directly amplify myelopoiesis through inflammation-triggered secretion of cytokines in the local bone marrow (BM) microenvironment. Our results identify a novel regulatory function for a subset of secretory MPP3 that controls myeloid differentiation through lineage-priming and cytokine production, and act as a self-reinforcing amplification compartment in stress and disease conditions. One-Sentence SummaryA secretory subset of multipotent hematopoietic progenitors augment myelopoiesis in stress and diseases conditions.

immunology↗