Activin A does not drive post-traumatic heterotopic ossification.

Autor: Hwang C; Department of Surgery, University of Michigan, Ann Arbor, MI, United States of America., Pagani CA; Department of Surgery, University of Michigan, Ann Arbor, MI, United States of America., Das N; Regeneron Pharmaceuticals, Tarrytown, NY, USA., Marini S; Department of Surgery, University of Michigan, Ann Arbor, MI, United States of America., Huber AK; Department of Surgery, University of Michigan, Ann Arbor, MI, United States of America., Xie L; Regeneron Pharmaceuticals, Tarrytown, NY, USA., Jimenez J; Regeneron Pharmaceuticals, Tarrytown, NY, USA., Brydges S; Regeneron Pharmaceuticals, Tarrytown, NY, USA., Lim WK; Regeneron Pharmaceuticals, Tarrytown, NY, USA., Nannuru KC; Regeneron Pharmaceuticals, Tarrytown, NY, USA., Murphy AJ; Regeneron Pharmaceuticals, Tarrytown, NY, USA., Economides AN; Regeneron Pharmaceuticals, Tarrytown, NY, USA., Hatsell SJ; Regeneron Pharmaceuticals, Tarrytown, NY, USA., Levi B; Department of Surgery, University of Michigan, Ann Arbor, MI, United States of America; Division of Plastic Surgery, Department of Surgery, University of Michigan Health System, 1500 E Medical Center Drive, SPC 5340, Ann Arbor, MI 48109-5340, United States of America. Electronic address: Blevi@umich.edu.
Jazyk: angličtina
Zdroj: Bone [Bone] 2020 Sep; Vol. 138, pp. 115473. Date of Electronic Publication: 2020 Jun 15.
DOI: 10.1016/j.bone.2020.115473
Abstrakt: Heterotopic ossification (HO), the formation of ectopic bone in soft tissues, has been extensively studied in its two primary forms: post-traumatic HO (tHO) typically found in patients who have experienced musculoskeletal or neurogenic injury and in fibrodysplasia ossificans progressiva (FOP), where it is genetically driven. Given that in both diseases HO arises via endochondral ossification, the molecular mechanisms behind both diseases have been postulated to be manifestations of similar pathways including those activated by BMP/TGFβ superfamily ligands. A significant step towards understanding the molecular mechanism by which HO arises in FOP was the discovery that FOP causing ACVR1 variants trigger HO in response to activin A, a ligand that does not activate signaling from wild type ACVR1, and that is not inherently osteogenic in wild type settings. The physiological significance of this finding was demonstrated by showing that activin A neutralizing antibodies stop HO in two different genetically accurate mouse models of FOP. In order to explore the role of activin A in tHO, we performed single cell RNA sequencing and compared the expression of activin A as well as other BMP pathway genes in tHO and FOP HO. We show that activin A is expressed in response to injury in both settings, but by different types of cells. Given that wild type ACVR1 does not transduce signal when engaged by activin A, we hypothesized that inhibition of activin A will not block tHO. Nonetheless, as activin A was expressed in tHO lesions, we tested its inhibition and compared it with inhibition of BMPs. We show here that anti-activin A does not block tHO, whereas agents such as antibodies that neutralize ACVR1 or ALK3-Fc (which blocks osteogenic BMPs) are beneficial, though not completely curative. These results demonstrate that inhibition of activin A should not be considered as a therapeutic strategy for ameliorating tHO.
(Copyright © 2020. Published by Elsevier Inc.)
Databáze: MEDLINE
Externí odkaz: