Search PubMed⌕ Search

Biomedical subjects

Catriona H M Jamieson

Publications and source records attributed to Catriona H M Jamieson.

7 recordsLinked to original sources

Nanobioreactor detection of space-associated hematopoietic stem and progenitor cell aging.

Human hematopoietic stem and progenitor cell (HSPC) fitness declines following exposure to stressors that reduce survival, dormancy, telomere maintenance, and self-renewal, thereby accelerating aging. While previous National Aeronautics and Space Administration (NASA) research revealed immune dysfunction in low-earth orbit (LEO), the impact of spaceflight on human HSPC aging had not been studied. To study HSPC aging, our NASA-supported Integrated Space Stem Cell Orbital Research (ISSCOR) team developed bone marrow niche nanobioreactors with lentiviral bicistronic fluorescent, ubiquitination-based cell-cycle indicator (FUCCI2BL) reporter for real-time HSPC tracking in artificial intelligence (AI)-driven CubeLabs. In month-long International Space Station (ISS) missions (SpX-24, SpX-25, SpX-26, and SpX-27) compared with ground controls, FUCCI2BL reporter, whole-genome and transcriptome sequencing, and cytokine arrays demonstrated cell-cycle, inflammatory cytokine, mitochondrial gene, human repetitive element, and apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like 3 (APOBEC3) deregulation together with clonal hematopoietic mutations. Furthermore, HSPC functionally organized multi-omics aging (HSPC-FOMA) analyses revealed reduced telomere maintenance, adenosine deaminase acting on RNA1 (ADAR1) p150 self-renewal gene expression, and replating capacity indicative of space-associated HSPC aging that may limit long-duration spaceflight.

Humans↗

The JAK2 V617F mutation occurs in hematopoietic stem cells in polycythemia vera and predisposes toward erythroid differentiation.

Although a large proportion of patients with polycythemia vera (PV) harbor a valine-to-phenylalanine mutation at amino acid 617 (V617F) in the JAK2 signaling molecule, the stage of hematopoiesis at which the mutation arises is unknown. Here we isolated and characterized hematopoietic stem cells (HSC) and myeloid progenitors from 16 PV patient samples and 14 normal individuals, testing whether the JAK2 mutation could be found at the level of stem or progenitor cells and whether the JAK2 V617F-positive cells had altered differentiation potential. In all PV samples analyzed, there were increased numbers of cells with a HSC phenotype (CD34+CD38-CD90+Lin-) compared with normal samples. Hematopoietic progenitor assays demonstrated that the differentiation potential of PV was already skewed toward the erythroid lineage at the HSC level. The JAK2 V617F mutation was detectable within HSC and their progeny in PV. Moreover, the aberrant erythroid potential of PV HSC was potently inhibited with a JAK2 inhibitor, AG490.

ADP-ribosyl Cyclase 1↗

Granulocyte-macrophage progenitors as candidate leukemic stem cells in blast-crisis CML.

BACKGROUND: The progression of chronic myelogenous leukemia (CML) to blast crisis is supported by self-renewing leukemic stem cells. In normal mouse hematopoietic stem cells, the process of self-renewal involves the beta-catenin-signaling pathway. We investigated whether leukemic stem cells in CML also use the beta-catenin pathway for self-renewal. METHODS: We used fluorescence-activated cell sorting to isolate hematopoietic stem cells, common myeloid progenitors, granulocyte-macrophage progenitors, and megakaryocyte-erythroid progenitors from marrow during several phases of CML and from normal marrow. BCR-ABL, beta-catenin, and LEF-1 transcripts were compared by means of a quantitative reverse-transcriptase-polymerase-chain-reaction assay in normal and CML hematopoietic stem cells and granulocyte-macrophage progenitors. Confocal fluorescence microscopy and a lymphoid enhancer factor/T-cell factor reporter assay were used to detect nuclear beta-catenin in these cells. In vitro replating assays were used to identify self-renewing cells as candidate leukemic stem cells, and the dependence of self-renewal on beta-catenin activation was tested by lentiviral transduction of hematopoietic progenitors with axin, an inhibitor of the beta-catenin pathway. RESULTS: The granulocyte-macrophage progenitor pool from patients with CML in blast crisis and imatinib-resistant CML was expanded, expressed BCR-ABL, and had elevated levels of nuclear beta-catenin as compared with the levels in progenitors from normal marrow. Unlike normal granulocyte-macrophage progenitors, CML granulocyte-macrophage progenitors formed self-renewing, replatable myeloid colonies, and in vitro self-renewal capacity was reduced by enforced expression of axin. CONCLUSIONS: Activation of beta-catenin in CML granulocyte-macrophage progenitors appears to enhance the self-renewal activity and leukemic potential of these cells.

Adult↗

Chronic versus acute myelogenous leukemia: a question of self-renewal.

Leukemia stem cells are defined as transformed hematopoietic stem cells or committed progenitor cells that have amplified or acquired the stem cell capacity for self-renewal, albeit in a poorly regulated fashion. In this issue of Cancer Cell, Huntly and colleagues report a striking difference in the ability of two leukemia-associated fusion proteins, MOZ-TIF2 and BCR-ABL, to transform myeloid progenitor populations. This rigorous study supports the idea of a hierarchy among leukemia-associated protooncogenes for their ability to endow committed myeloid progenitors with the self-renewal capacity driving leukemic stem cell propagation, and sheds new light on the pathogenesis of chronic and acute myelogenous leukemias.

Acute Disease↗

Normal and leukemic hematopoiesis: are leukemias a stem cell disorder or a reacquisition of stem cell characteristics?

Leukemia can be viewed as a newly formed, abnormal hematopoietic tissue initiated by a few leukemic stem cells (LSCs) that undergo an aberrant and poorly regulated process of organogenesis analogous to that of normal hematopoietic stem cells. A hallmark of all cancers is the capacity for unlimited self-renewal, which is also a defining characteristic of normal stem cells. Given this shared attribute, it has been proposed that leukemias may be initiated by transforming events that take place in hematopoietic stem cells. Alternatively, leukemias may also arise from more committed progenitors caused by mutations and/or selective expression of genes that enhance their otherwise limited self-renewal capabilities. Identifying the LSCs for each type of leukemia is a current challenge and a critical step in understanding their respective biologies and may provide key insights into more effective treatments. Moreover, LSC identification and purification will provide a powerful diagnostic, prognostic, and therapeutic tool in the clinic.

Animals↗

Allogeneic hematopoietic cell transplantation for patients with high-risk acute lymphoblastic leukemia in first or second complete remission using fractionated total-body irradiation and high-dose etoposide: a 15-year experience.

OBJECTIVE: The rationale for this retrospective study was to identify the long-term overall and event-free survival, relapse, and treatment-related mortality rates of high-risk pediatric and adult first (CR1) and second remission (CR2) patients with acute lymphoblastic leukemia (ALL) who were treated with a single preparatory regimen consisting of fractionated total-body irradiation (FTBI) and high-dose etoposide (VP-16) prior to allogeneic hematopoietic cell transplantation. PATIENTS AND METHODS: Over a 15-year period at Stanford University Medical Center, 85 consecutive high-risk pediatric (up to age 17 years; n=41) and adult (age 18-55 years; n=44); patients with leukemia (ALL) in CR1 (n=55) and CR2 (n=30) received HLA-matched sibling allogeneic bone marrow or peripheral blood progenitor grafts after being treated with FTBI (1320 cGy) and high-dose VP-16 (60 mg/kg) as their preparatory regimen. The majority of patients transplanted in CR1 (n=45) had high-risk features, including age above 30 years, white blood cell count at presentation exceeding 25000/microL, extramedullary disease, need for more than 4 weeks of induction chemotherapy to achieve CR, or high-risk chromosomal translocations. Most patients transplanted in CR1 were adults (n=39), whereas patients in CR2 were primarily children or adolescents (n=25). RESULTS: The 10-year Kaplan-Meier estimates of relapse were significantly (p=0.05) lower in CR1 patients (15%+/-10%) than in CR2 patients (33%+/-20%). Relapse was the most common cause of treatment failure in patients transplanted in CR2. There was a significantly (p=0.05) higher rate of chronic graft-vs-host disease in CR1 (32%+/-14%) compared with CR2 (9%+/-11%) patients; however, overall survival for patients transplanted in CR1 (66%+/-14%) was comparable (p=0.67) to that of patients transplanted in CR2 (62%+/-19%). Event-free survival rates also were similar (p=0.53) between CR1 (64%+/-14%) and CR2 (61%+/-18%) patients. Treatment-related mortality rates were equivalent (p=0.51) between CR1 and CR2, as well as between Philadelphia chromosome (Ph) positive (Ph(+))and Ph(-) (p=0.23) ALL patients. CONCLUSION: Overall, FTBI/VP-16 is a highly effective preparatory regimen that provides durable remissions for patients receiving allogeneic hematopoietic cell transplantation for high-risk ALL in CR1 or CR2.

Adolescent↗