scholarly journals β-Thalassemia: evolving treatment options beyond transfusion and iron chelation

Hematology ◽  
2021 ◽  
Vol 2021 (1) ◽  
pp. 600-606
Author(s):  
Arielle L. Langer ◽  
Erica B. Esrick
Keyword(s):  
Transforming Growth Factor ◽  
Globin Gene ◽  
Treatment Options ◽  
Iron Chelation ◽  
Transforming Growth Factor Β ◽  
Zinc Finger Nucleases ◽  
Ineffective Erythropoiesis ◽  
Hemoglobin F ◽  
Hematopoietic Stem ◽  
Transfusion Independence

Abstract After years of reliance on transfusion alone to address anemia and suppress ineffective erythropoiesis in β-thalassemia, many new therapies are now in development. Luspatercept, a transforming growth factor–β inhibitor, has demonstrated efficacy in reducing ineffective erythropoiesis, improving anemia, and possibly reducing iron loading. However, many patients do not respond to luspatercept, so additional therapeutics are needed. Several medications in development aim to induce hemoglobin F (HbF): sirolimus, benserazide, and IMR-687 (a phosphodiesterase 9 inhibitor). Another group of agents seeks to ameliorate ineffective erythropoiesis and improve anemia by targeting abnormal iron metabolism in thalassemia: apotransferrin, VIT-2763 (a ferroportin inhibitor), PTG-300 (a hepcidin mimetic), and an erythroferrone antibody in early development. Mitapivat, a pyruvate kinase activator, represents a unique mechanism to mitigate ineffective erythropoiesis. Genetically modified autologous hematopoietic stem cell transplantation offers the potential for lifelong transfusion independence. Through a gene addition approach, lentiviral vectors have been used to introduce a β-globin gene into autologous hematopoietic stem cells. One such product, betibeglogene autotemcel (beti-cel), has reached phase 3 trials with promising results. In addition, 2 gene editing techniques (CRISPR-Cas9 and zinc-finger nucleases) are under investigation as a means to silence BCL11A to induce HbF with agents designated CTX001 and ST-400, respectively. Results from the many clinical trials for these agents will yield results in the next few years, which may end the era of relying on transfusion alone as the mainstay of thalassemia therapy.

scholarly journals Health state utilities associated with treatment for transfusion-dependent β-thalassemia

2019 ◽  
Vol 21 (3) ◽  
pp. 397-407
Author(s):  
Louis S. Matza ◽  
L. Clark Paramore ◽  
Katie D. Stewart ◽  
Hayley Karn ◽  
Minesh Jobanputra ◽  
...  
Keyword(s):  
Treatment Options ◽  
Chronic Gvhd ◽  
Autologous Transplantation ◽  
Iron Chelation ◽  
Cost Utility ◽  
Health State ◽  
Health States ◽  
Hematopoietic Stem ◽  
Substantial Impact ◽  
Transfusion Independence

Abstract Objectives Transfusion-dependent β-thalassemia (TDT) is a genetic disease that affects production of red blood cells. Conventional treatment involves regular red blood cell transfusions and iron chelation, which has a substantial impact on quality of life. While potentially curative, allogeneic hematopoietic stem cell transplantation (allo-HSCT) is associated with risk of complications, including graft-versus-host disease (GvHD). Gene addition therapy, a novel treatment approach, involves autologous transplantation of the patient’s own genetically modified hematopoietic stem cells. The purpose of this study was to estimate utilities associated with treatment approaches for TDT. Methods General population respondents in England valued eight health state vignettes (developed with clinician, patient, and parent input) in time trade-off interviews. Results A total of 207 participants completed interviews (49.8% female; mean age = 43.2 years). Mean (SD) utilities for the pre-transplant health states were 0.73 (0.25) with oral chelation and 0.63 (0.32) with subcutaneous chelation. Mean utilities for the transplant year were 0.62 (0.35) for gene addition therapy, 0.47 (0.39) for allo-HSCT, and 0.39 (0.39) for allo-HSCT with acute GvHD. Post-transplant utilities were 0.93 (0.15) for transfusion independent, 0.75 (0.25) for 60% transfusion reduction, and 0.51 (0.38) for chronic GvHD. Acute and chronic GvHD were associated with significant disutility (acute = − 0.09, p < 0.0001; chronic = − 0.42, p < 0.0001). Conclusions Utilities followed expected patterns, with logical differences between treatment options for TDT and substantially greater utility for transfusion independence than for ongoing treatment involving transfusion and chelation. These utilities may be useful in cost-utility models estimating the value of treatments for TDT.

scholarly journals Serial transplantation reveals a critical role for endoglin in hematopoietic stem cell quiescence

Blood ◽  
2019 ◽  
Vol 133 (7) ◽  
pp. 688-696 ◽  
Author(s):  
Luciene Borges ◽  
Vanessa K. P. Oliveira ◽  
June Baik ◽  
Sean C. Bendall ◽  
Rita C. R. Perlingeiro
Keyword(s):  
Stem Cell ◽  
Hematopoietic Stem Cell ◽  
Transforming Growth Factor ◽  
Critical Role ◽  
Transforming Growth Factor Β ◽  
Hematopoietic Stem ◽  
Conditional Deletion ◽  
Stem Cell Quiescence ◽  
Β Receptor ◽  
Serial Transplantation

Abstract Transforming growth factor β (TGF-β) is well known for its important function in hematopoietic stem cell (HSC) quiescence. However, the molecular mechanism underlining this function remains obscure. Endoglin (Eng), a type III receptor for the TGF-β superfamily, has been shown to selectively mark long-term HSCs; however, its necessity in adult HSCs is unknown due to embryonic lethality. Using conditional deletion of Eng combined with serial transplantation, we show that this TGF-β receptor is critical to maintain the HSC pool. Transplantation of Eng-deleted whole bone marrow or purified HSCs into lethally irradiated mice results in a profound engraftment defect in tertiary and quaternary recipients. Cell cycle analysis of primary grafts revealed decreased frequency of HSCs in G0, suggesting that lack of Eng impairs reentry of HSCs to quiescence. Using cytometry by time of flight (CyTOF) to evaluate the activity of signaling pathways in individual HSCs, we find that Eng is required within the Lin−Sca+Kit+–CD48− CD150+ fraction for canonical and noncanonical TGF-β signaling, as indicated by decreased phosphorylation of SMAD2/3 and the p38 MAPK-activated protein kinase 2, respectively. These findings support an essential role for Eng in positively modulating TGF-β signaling to ensure maintenance of HSC quiescence.

scholarly journals New therapeutic targets in transfusion-dependent and -independent thalassemia

Hematology ◽  
2017 ◽  
Vol 2017 (1) ◽  
pp. 278-283 ◽  
Author(s):  
M. Domenica Cappellini ◽  
Irene Motta
Keyword(s):  
Iron Overload ◽  
Ex Vivo ◽  
Wide Spectrum ◽  
Disease Process ◽  
Iron Chelation ◽  
Current Treatment ◽  
Compound Heterozygous ◽  
Ineffective Erythropoiesis ◽  
Hematopoietic Stem ◽  
Hemoglobin E

Abstract β-Thalassemias are characterized by reduced production of β-globin chain, resulting in α/β-chain unbalance and precipitation of α-globin–heme complexes and determining ineffective erythropoiesis. Ineffective erythropoiesis, chronic hemolytic anemia, and compensatory hematopoietic expansion are the disease hallmarks, and they are related to the severity of the chain unbalance. Several clinical forms of β-thalassemia, including the coinheritance of β-thalassemia with hemoglobin E resulting in hemoglobin E/β-thalassemia, have been described. Clinically, β-thalassemias can be classified as transfusion-dependent thalassemia (TDT) and non–transfusion-dependent thalassemia (NTDT) according to the severity of the phenotype, which is caused by a wide spectrum of mutations in a homozygous or compound heterozygous state. Current treatment of TDT consists of regular transfusions that lead to iron overload, requiring iron chelation to prevent iron-related organ toxicity. NTDT patients do not require transfusions or only occasionally require them; however, they develop iron overload as well because of increased intestinal iron absorption caused by chronic anemia. Hematopoietic stem cell allogenic transplant is the only approved cure for β-thalassemia; however, it is still limited by clinical conditions and the availability of matched donors as well as by potential graft-versus-host disease (GVHD). Gene therapy could avoid the GVHD risk, although hematopoietic stem cells must be genetically modified ex vivo. Epigenetic manipulation and genomic editing are novel experimental approaches. An increased understanding of the pathophysiology that controls the disease process prompted us to explore alternative therapeutic approaches that address the underlying chain unbalance, ineffective erythropoiesis, and iron dysregulation. Molecules, such as JAK2 inhibitors and the activin-receptor ligand trap that target ineffective erythropoiesis, are already in clinical trials with promising results. Other agents aimed to generate iron-restricted erythropoiesis are also under experimental evaluation.

TIF1γ Knockdown Enhances Hematopoietic Stem Cell Self Renewal with Preferential Myeloid Differentiation and Delayed Erythropoiesis

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4829-4829
Author(s):  
David C Dorn ◽  
Wei He ◽  
Joan Massague ◽  
Malcolm A.S. Moore
Keyword(s):  
Transforming Growth Factor ◽  
Conflicts Of Interest ◽  
Erythroid Differentiation ◽  
Transforming Growth Factor Β ◽  
Human Umbilical Cord Blood ◽  
Human Umbilical Cord ◽  
Self Renewal ◽  
Hematopoietic Stem

Abstract Abstract 4829 The role of TIF1γ in hematopoiesis is still incompletely understood. We previously identified TIF1γ as a novel binding factor for Smad2/3 in the Transforming Growth Factor-β (TFGβ)-inducible signaling pathway implicated in the enhancement of erythropoiesis. To investigate the function of TIF1γ in regulation of hematopoietic stem cells we abrogated TIF1γ signaling by shRNA gamma-retroviral gene transfer in human umbilical cord blood-derived CD34+ hematopoietic stem/ progenitor cells (HCS/ HPCs). Upon blocking TIF1γ the self-renewal capacity of HSCs was enhanced two-fold in vitro as measured by week 5 CAFC assay and three-fold in vivo as measured by competitive engraftment in NOD/ SCID mice over controls. This was associated with a delay in erythroid differentiation and enhanced myelopoiesis. These changes were predominantly observed after TIF1γ knockdown and only mildly after Smad2 depletion but not after Smad3 or 4 reduction. Our data reveal a role for TIF1γ-mediated signaling in the regulation of HSC self-renewal and differentiation. Disclosures: No relevant conflicts of interest to declare.

scholarly journals TAK1 is required for the survival of hematopoietic cells and hepatocytes in mice

2008 ◽  
Vol 205 (7) ◽  
pp. 1611-1619 ◽  
Author(s):  
Minghui Tang ◽  
Xudong Wei ◽  
Yinshi Guo ◽  
Peter Breslin ◽  
Shubin Zhang ◽  
...  
Keyword(s):  
Cell Death ◽  
B Cell ◽  
Cell Activation ◽  
Transforming Growth Factor ◽  
Apoptotic Cell ◽  
Hematopoietic Cells ◽  
Transforming Growth Factor Β ◽  
Nuclear Factor Κb ◽  
Regulation Of Expression ◽  
Hematopoietic Stem

Transforming growth factor β–activated kinase 1 (TAK1), a member of the MAPKKK family, is a key mediator of proinflammatory and stress signals. Activation of TAK1 by proinflammatory cytokines and T and B cell receptors induces the nuclear localization of nuclear factor κB (NF-κB) and the activation of c-Jun N-terminal kinase (JNK)/AP1 and P38, which play important roles in mediating inflammation, immune responses, T and B cell activation, and epithelial cell survival. Here, we report that TAK1 is critical for the survival of both hematopoietic cells and hepatocytes. Deletion of TAK1 results in bone marrow (BM) and liver failure in mice due to the massive apoptotic death of hematopoietic cells and hepatocytes. Hematopoietic stem cells and progenitors were among those hematopoietic cells affected by TAK1 deletion–induced cell death. This apoptotic cell death is autonomous, as demonstrated by reciprocal BM transplantation. Deletion of TAK1 resulted in the inactivation of both JNK and NF-κB signaling, as well as the down-regulation of expression of prosurvival genes.

scholarly journals Smad4 is critical for self-renewal of hematopoietic stem cells

2007 ◽  
Vol 204 (3) ◽  
pp. 467-474 ◽  
Author(s):  
Göran Karlsson ◽  
Ulrika Blank ◽  
Jennifer L. Moody ◽  
Mats Ehinger ◽  
Sofie Singbrant ◽  
...  
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
In Vitro Proliferation ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Early Embryonic Lethality

Members of the transforming growth factor β (TGF-β) superfamily of growth factors have been shown to regulate the in vitro proliferation and maintenance of hematopoietic stem cells (HSCs). Working at a common level of convergence for all TGF-β superfamily signals, Smad4 is key in orchestrating these effects. The role of Smad4 in HSC function has remained elusive because of the early embryonic lethality of the conventional knockout. We clarify its role by using an inducible model of Smad4 deletion coupled with transplantation experiments. Remarkably, systemic induction of Smad4 deletion through activation of MxCre was incompatible with survival 4 wk after induction because of anemia and histopathological changes in the colonic mucosa. Isolation of Smad4 deletion to the hematopoietic system via several transplantation approaches demonstrated a role for Smad4 in the maintenance of HSC self-renewal and reconstituting capacity, leaving homing potential, viability, and differentiation intact. Furthermore, the observed down-regulation of notch1 and c-myc in Smad4−/− primitive cells places Smad4 within a network of genes involved in the regulation HSC renewal.

Smad5 is dispensable for adult murine hematopoiesis

Blood ◽  
2006 ◽  
Vol 108 (12) ◽  
pp. 3707-3712 ◽  
Author(s):  
Sofie Singbrant ◽  
Jennifer L. Moody ◽  
Ulrika Blank ◽  
Goran Karlsson ◽  
Lieve Umans ◽  
...  
Keyword(s):  
Stem Cell ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Conditional Knockout ◽  
Phenotypic Characterization ◽  
Normal Numbers ◽  
Hematopoietic Stem ◽  
Adult Mice ◽  
Lineage Distribution

AbstractSmad5 is known to transduce intracellular signals from bone morphogenetic proteins (BMPs), which belong to the transforming growth factor-β (TGF-β) superfamily and are involved in the regulation of hematopoiesis. Recent findings suggest that BMP4 stimulates proliferation of human primitive hematopoietic progenitors in vitro, while early progenitors from mice deficient in Smad5 display increased self-renewal capacity in murine embryonic hematopoiesis. Here, we evaluate the role of Smad5 in the regulation of hematopoietic stem cell (HSC) fate decisions in adult mice by using an inducible MxCre-mediated conditional knockout model. Surprisingly, analysis of induced animals revealed unperturbed cell numbers and lineage distribution in peripheral blood (PB), bone marrow (BM), and the spleen. Furthermore, phenotypic characterization of the stem cell compartment revealed normal numbers of primitive lin–Sca-1+c-Kit+ (LSK) cells in Smad5–/– BM. When transplanted in a competitive fashion into lethally irradiated primary and secondary recipients, Smad5-deficient BM cells competed normally with wild-type (wt) cells, were able to provide long-term reconstitution for the hosts, and displayed normal lineage distribution. Taken together, Smad5-deficient HSCs from adult mice show unaltered differentiation, proliferation, and repopulating capacity. Therefore, in contrast to its role in embryonic hematopoiesis, Smad5 is dispensable for hematopoiesis in the adult mouse.

scholarly journals Myeloid Fbxw7 Prevents Pulmonary Fibrosis by Suppressing TGF-β Production

2022 ◽  
Vol 12 ◽  
Author(s):  
Jia He ◽  
Yue Du ◽  
Gaopeng Li ◽  
Peng Xiao ◽  
Xingzheng Sun ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Mononuclear Cells ◽  
Transforming Growth Factor ◽  
Treatment Options ◽  
Myeloid Cell ◽  
Transforming Growth Factor Β ◽  
Peripheral Blood Mononuclear ◽  
Regulation Mechanisms ◽  
Insight Into

Idiopathic pulmonary fibrosis (IPF) is a group of chronic interstitial pulmonary diseases characterized by an inexorable decline in lung function with limited treatment options. The abnormal expression of transforming growth factor-β (TGF-β) in profibrotic macrophages is linked to severe pulmonary fibrosis, but the regulation mechanisms of TGF-β expression are incompletely understood. We found that decreased expression of E3 ubiquitin ligase Fbxw7 in peripheral blood mononuclear cells (PBMCs) was significantly related to the severity of pulmonary fibrosis in IPF patients. Fbxw7 is identified to be a crucial suppressing factor for pulmonary fibrosis development and progression in a mouse model induced by intratracheal bleomycin treatment. Myeloid cell-specific Fbxw7 deletion increases pulmonary monocyte-macrophages accumulation in lung tissue, and eventually promotes bleomycin-induced collagen deposition and progressive pulmonary fibrosis. Notably, the expression of TGF-β in profibrotic macrophages was significantly upregulated in myeloid cell-specific Fbxw7 deletion mice after bleomycin treatment. C-Jun has long been regarded as a critical transcription factor of Tgfb1, we clarified that Fbxw7 inhibits the expression of TGF-β in profibrotic macrophages by interacting with c-Jun and mediating its K48-linked ubiquitination and degradation. These findings provide insight into the role of Fbxw7 in the regulation of macrophages during the pathogenesis of pulmonary fibrosis.

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