Splicing of erythroid transcription factor is associated with therapeutic response in myelodysplastic syndromes
Anemia is the primary clinical manifestation of myelodysplastic syndromes (MDSs), but the molecular pathogenesis of ineffective erythropoiesis remains incompletely understood. Luspatercept, an activin receptor 2B (ACVRIIB-Fc) ligand trap, has been approved to treat anemia; however, its molecular mechanism of action is unclear. We found that activin receptor 2B (ACVR2B), its ligand growth and differentiation factor 11 (GDF11), and an effector, SMAD2, are upregulated in samples of patients with MDS. GDF11 inhibited human erythropoiesis in vitro and caused anemia in zebrafish, effects that were abrogated by luspatercept. Upon GDF11 stimulation of human erythroid progenitors, SMAD2 binding occurred in the erythroid regulatory regions, including at the GATA1 intron. Intronic SMAD2-binding led to skipping of exon 2 of GATA1, resulting in a shorter, hypomorphic isoform (GATA1s). CRISPR deletion of the SMAD2-binding intronic region decreased GATA1s production upon GDF11 stimulation. Expression of GATA1s in a mouse model led to anemia, rescued by a murine ActRIIB-Fc (RAP-536). Finally, RNA-Seq analysis of samples from the phase 3 MEDALIST trial revealed that responders to luspatercept had a higher proportion of GATA1s compared with nonresponders. Moreover, the increase in RBCs after treatment was linked to a relative decrease in GATA1s isoforms. Our study indicates that GDF11-mediated SMAD2 activation results in an increase in functionally impaired GATA1 isoforms, consequently contributing to anemia and influencing responses to luspatercept in MDS.
Authors
- Andrea Pellagatti (ORCID: https://orcid.org/0000-0002-6122-0221)
- Kith Pradhan (ORCID: https://orcid.org/0000-0001-7089-1652)
- Amittha Wickrema (ORCID: https://orcid.org/0000-0003-4035-3014)
- Srinivas Aluri (ORCID: https://orcid.org/0000-0003-4084-1747)
- Ellen Fraint (ORCID: https://orcid.org/0000-0001-5548-0206)
- Kimo Bachiashvili
- Teresa V. Bowman (ORCID: https://orcid.org/0000-0002-6103-6862)
- Anitria Cotton
- Milagros Carbajal
- Leah Kravets (ORCID: https://orcid.org/0000-0002-2242-0087)
- Satish K. Nandakumar (ORCID: https://orcid.org/0000-0002-7853-426X)
- Rajasekhar N.V.S. Suragani (ORCID: https://orcid.org/0000-0003-2754-1782)
- Te Ling (ORCID: https://orcid.org/0000-0002-0315-2662)
- Jacqueline Boultwood (ORCID: https://orcid.org/0000-0002-4330-2928)
- Sadanand Vodala
- Shanisha Gordon-Mitchell (ORCID: https://orcid.org/0009-0007-5335-0046)
- Jung‐In Yang (ORCID: https://orcid.org/0000-0003-0685-355X)
- Beamon Agarwal (ORCID: https://orcid.org/0000-0002-3655-1694)
- Anjali Budhathoki
- Ulrich G. Steidl (ORCID: https://orcid.org/0000-0002-9458-1795)
- John D. Crispino (ORCID: https://orcid.org/0000-0002-8182-8306)
- Kevin Zhang (ORCID: https://orcid.org/0000-0002-6028-6536)
- Amit K. Verma (ORCID: https://orcid.org/0000-0001-7592-7693)
- Aditi Shastri
- Aarif Ahsan
- Gowri Poigaialwar
- Srabani Sahu (ORCID: https://orcid.org/0009-0002-3667-3592)
- Samarpana Chakraborty (ORCID: https://orcid.org/0009-0005-1273-7960)
- Rongbao Zhao
Institutions
- Albert Einstein College of Medicine (US)
- St. Jude Children's Research Hospital (US)
- Bristol-Myers Squibb (Germany) (DE)
- University of Oxford (GB)
- University of Chicago (US)
- Bristol-Myers Squibb (United States) (US)
- Caerus Molecular Diagnostics (United States) (US)
- Bristol-Myers Squibb (Sweden) (SE)
Publication Details
- Journal
- Journal of Clinical Investigation
- Published
- 2025-05-27
- DOI
- https://doi.org/10.1172/jci189266
- Citations
- 3
- Primary Topic
- RNA Research and Splicing
- Type
- article
- Field-Weighted Citation Impact
- 2.42
Funders
- Diamond Blackfan Anemia Foundation
- Leukemia and Lymphoma Society
- Edward P. Evans Foundation