Biology subjects

MacKenzie, T. C.

Publications and source records attributed to MacKenzie, T. C..

3 recordsLinked to original sources

bioRxiv2024

In Utero Hematopoietic Stem Cell Transplant for Fanconi Anemia

Fanconi Anemia (FA) is an inherited DNA-repair deficiency caused by mutations in diverse Fanc genes that leads to bone marrow failure and malignancies. FA disease begins at early embryonic stages, and while FA prenatal testing has long been available, no fetal therapies for FA currently exist. Postnatally, FA hematologic disease can be cured through allogeneic hematopoietic stem cell transplantation (HSCT); however, this requires chemotherapy and/or irradiation-based conditioning which amongst various side-effects also increases likelihood of malignancies later in life in these fragile patients. Given fetal immune tolerance and the competitive advantage of healthy hematopoietic stem and progenitor cells (HSPCs) over failing FA HSPCs, in utero HSCT without conditioning may be an alternative approach to stabilization of the hematopoietic system without conventional toxicities. We performed in utero HSCT using HSPCs from wildtype (WT) donors into two FA mouse models (Fancd2-/-, Fanca-/-) and observed robust multi-lineage hematopoietic donor engraftment in homozygous FA mice compared to both heterozygous FA and WT littermates. Upon serial assessments, we also observed increasing donor chimerism up to 94.1%, showcasing the competitive advantage of WT donor HSPCs over FA HSPCs. Given that 1% donor chimerism is predicted to stabilize FA BM, in utero HSCT may be a safe and curative prenatal treatment for all subtypes of FA.

cell biology↗

bioRxiv2024

A Multiomics, Spatiotemporal, and Single Cell Atlas for Mapping Cell-Type-Specific Dysregulation at the Maternal-Fetal Interface

The placenta, the first organ to functionally mature, undergoes disordered development in many pregnancy complications. Molecular investigations have been hampered by the extreme cellular heterogeneity of the placenta, and this complexity is further exaggerated at the maternal-fetal interface where maternal and fetal cells co-mingle. We generated the paired single nucleus epigenomes and transcriptome for each of [~]200,000 cells at the human maternal-fetal interface from early pregnancy to term. These data identified cell-type-specific transcriptional regulatory programs and uncovered key transcription factors driving the lineage differentiation of placental cytotrophoblasts. Integrating spatial single cell proteomics profiling, we localized the observed cell types in situ, and characterized the dynamic stages and distinct features of endothelial cells of maternal spiral arteries remodeled by extravillous cytotrophoblasts. Integrative analyses of the single cell data across gestation enabled fine-mapping of the developmental trajectories of cytotrophoblasts and decidual stromal cells, and defining the signature molecular profiles of known and novel cell (sub)types. To demonstrate clinical value, we integrated the reference single cell data with large-scale population genomes from pregnancy complications and identified the most vulnerable maternal and fetal cell types in preeclampsia, preterm birth, and miscarriage. This study presents the most comprehensive placental and decidual single cell resource across gestation to date, reveals new insights into the drivers of normal human placentation, and uncovers the cellular basis of dysfunction associated with common pregnancy complications.

genomics↗

bioRxiv2023

Dual α-globin and truncated erythropoietin receptor knock-in restores hemoglobin production in α-thalassemia major-derived hematopoietic stem and progenitor cells

Alpha-thalassemia is an autosomal recessive disease with increasing worldwide prevalence. The molecular basis is due to mutation or deletion of one or more duplicated -globin genes, and disease severity is directly related to the number of allelic copies compromised. The most severe form, -thalassemia major (TM), results from loss of all four copies of -globin and has historically resulted in fatality in utero. However, in utero transfusions now enable survival to birth. Postnatally, patients face challenges similar to {beta}-thalassemia, including severe anemia and erythrotoxicity due to imbalance of {beta}-globin and -globin chains. While curative, hematopoietic stem cell transplantation (HSCT) is limited by donor availability and potential transplant-related complications. Despite progress in genome editing treatments for {beta}-thalassemia, there is no analogous curative option for patients suffering from -thalassemia. To address this, we designed a novel Cas9/AAV6-mediated genome editing strategy that integrates a functional -globin gene into the {beta}-globin locus in TM patient-derived hematopoietic stem and progenitor cells (HSPCs). Incorporation of a truncated erythropoietin receptor transgene into the -globin integration cassette dramatically increased erythropoietic output from edited HSPCs and led to the most robust production of -globin, and consequently normal hemoglobin. By directing edited HSPCs toward increased production of clinically relevant RBCs instead of other divergent cell types, this approach has the potential to mitigate the limitations of traditional HSCT for the hemoglobinopathies, including low genome editing and low engraftment rates. These findings support development of a definitive ex vivo autologous genome editing strategy that may be curative for -thalassemia. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=177 SRC="FIGDIR/small/555926v2_ufig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@1b63dacorg.highwire.dtl.DTLVardef@18b25a1org.highwire.dtl.DTLVardef@53835corg.highwire.dtl.DTLVardef@d52bf5_HPS_FORMAT_FIGEXP M_FIG C_FIG

molecular biology↗