Publications by authors named "Katherine Fegan"
Article Synopsis
- Natural killer (NK) cells, essential to the innate immune system, develop from specific progenitors known as erythro-myeloid progenitors (EMPs) found in the yolk sac of mice.
- These EMP-derived NK cells and fetal NK cells are more capable of degranulation, meaning they can better respond to immune challenges, compared to adult NK cells.
- Human pluripotent stem cells also show a similar pattern, as they produce NK cells with strong cytotoxic abilities, but the responses vary with other progenitors, highlighting the importance of developmental origin in creating effective immunotherapies.
Platelets are essential for hemostasis; however, several studies have identified age-dependent differences in platelet function. To better understand the origins of fetal platelet function, we have evaluated the contribution of the fetal-specific RNA binding protein in the megakaryocyte/platelet lineage. Because activated fetal platelets have very low levels of P-selectin, we hypothesized that the expression of platelet P-selectin is part of a fetal-specific hematopoietic program conferred by Lin28b.
View Article and Find Full Text PDFAdult-repopulating hematopoietic stem cells (HSCs) emerge in low numbers in the midgestation mouse embryo from a subset of arterial endothelium, through an endothelial-to-hematopoietic transition. HSC-producing arterial hemogenic endothelium relies on the establishment of embryonic blood flow and arterial identity, and requires β-catenin signaling. Specified prior to and during the formation of these initial HSCs are thousands of yolk sac-derived erythro-myeloid progenitors (EMPs).
View Article and Find Full Text PDFHematopoietic potential arises in mammalian embryos before adult-repopulating hematopoietic stem cells (HSCs). At embryonic day 9.5 (E9.
View Article and Find Full Text PDFRed blood cells (RBCs), responsible for oxygen delivery and carbon dioxide exchange, are essential for our well-being. Alternative RBC sources are needed to meet the increased demand for RBC transfusions projected to occur as our population ages. We previously have discovered that erythroblasts derived from the early mouse embryo can self-renew extensively ex vivo for many months.
View Article and Find Full Text PDFArticle Synopsis
- Megakaryocyte (MK) development in bone marrow involves a process where MK progenitors initially proliferate in the endosteal niche and then mature in the sinusoidal vascular niche, crucial for platelet production.
- The chemokine SDF-1, through its receptor CXCR4, guides the movement of MKs toward blood vessels, enhancing their association with the vasculature and stimulating thrombopoiesis without increasing the overall number of MKs.
- Alterations in SDF-1 distribution, especially after radiation injury, impact MK localization and, consequently, platelet production, suggesting that manipulating SDF-1 can help treat conditions like radiation-induced thrombocytopenia.
Article Synopsis
- Sorting nexin 3 (Snx3) is essential for recycling the transferrin receptor (Tfrc), which is crucial for iron delivery to red blood cell progenitors.
- Knocking down Snx3 leads to anemia and hemoglobin issues due to disrupted iron uptake via transferrin, with excess iron accumulating in endosomes.
- Snx3 interacts with the retromer component Vps35 to help sort Tfrc, highlighting its role in iron balance and red blood cell production, and presenting it as a potential target for studying iron metabolism disorders.