Stromal SPARC contributes to the detrimental fibrotic changes associated with myeloproliferation whereas its deficiency favors myeloid cell expansion

Claudio Tripodo, Sabina Sangaletti, Carla Guarnotta, Pier P. Piccaluga, Matilde Cacciatore, Michela Giuliano, Giovanni Franco, Claudia Chiodoni, Marika Sciandra, Silvia Miotti, Giuseppe Calvaruso, Alessandra Carè, Ada M. Florena, Katia Scotlandi, Attilio Orazi, Stefano A. Pileri, Mario P. Colombo

Research output: Contribution to journalArticle

Abstract

In myeloid malignancies, the neoplastic clone outgrows normal hematopoietic cells toward BM failure. This event is also sustained by detrimental stromal changes, such as BM fibrosis and osteosclerosis, whose occurrence is harbinger of a dismal prognosis. We show that the matricellular protein SPARC contributes to the BM stromal response to myeloproliferation. The degree of SPARC expression in BM stromal elements, including CD146+ mesenchymal stromal cells, correlates with the degree of stromal changes, and the severity of BM failure characterizing the prototypical myeloproliferative neoplasm primary myelofibrosis. Using Sparc-/- mice and BM chimeras, we demonstrate that SPARC contributes to the development of significant stromal fibrosis in a model of thrombopoietin-induced myelofibrosis. We found that SPARC deficiency in the radioresistant BM stroma compartment impairs myelofibrosis but, at the same time, associates with an enhanced reactive myeloproliferative response to thrombopoietin. The link betwen SPARC stromal deficiency and enhanced myeloid cell expansion under a myeloproliferative spur is also supported by the myeloproliferative phenotype resulting from the transplantation of defective Apcmin mutant hematopoietic cells into Sparc-/- but not WT recipient BM stroma. Our results highlight a complex influence of SPARC over the stromal and hematopoietic BM response in myeloproliferative conditions.

Original languageEnglish
Pages (from-to)3541-3554
Number of pages14
JournalBlood
Volume120
Issue number17
DOIs
Publication statusPublished - Oct 25 2012

    Fingerprint

ASJC Scopus subject areas

  • Hematology
  • Biochemistry
  • Cell Biology
  • Immunology

Cite this

Tripodo, C., Sangaletti, S., Guarnotta, C., Piccaluga, P. P., Cacciatore, M., Giuliano, M., Franco, G., Chiodoni, C., Sciandra, M., Miotti, S., Calvaruso, G., Carè, A., Florena, A. M., Scotlandi, K., Orazi, A., Pileri, S. A., & Colombo, M. P. (2012). Stromal SPARC contributes to the detrimental fibrotic changes associated with myeloproliferation whereas its deficiency favors myeloid cell expansion. Blood, 120(17), 3541-3554. https://doi.org/10.1182/blood-2011-12-398537