2. Academic Validation
  3. Simtuzumab Attenuates Loxl2-Mediated Extracellular Matrix Remodeling and Preserves Cardiac Function in LMNA Mutation-Induced Dilated Cardiomyopathy

Simtuzumab Attenuates Loxl2-Mediated Extracellular Matrix Remodeling and Preserves Cardiac Function in LMNA Mutation-Induced Dilated Cardiomyopathy

  • Circ Heart Fail. 2026 Apr;19(4):e013806. doi: 10.1161/CIRCHEARTFAILURE.125.013806.
Marie Kervella # 1 2,  Charlotta S Behrens # 3 4,  Cécile Peccate 1,  Zoheir Guesmia 1,  Fiorella Grandi 1,  Nathalie Mougenot 5,  Anne Forand 1 6,  Azzouz Charrabi 2,  Guy Brochier 7,  Ramaroson Andriantsitohaina 2,  Sonia R Singh 3 4,  Thomas Eschenhagen 3 4,  Albano C Meli # 2,  Antoine Muchir # 1
Affiliations

Affiliations

  • 1 Institute of Myology, Center of Research in Myology, Sorbonne University, Inserm, Paris, France (M.K., C.P., Z.G., F.G., A.F., A.M.).
  • 2 PhyMedExp, University of Montpellier, Inserm, CNRS, France (M.K., A.C., R.A., A.C.M.).
  • 3 Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Germany (C.S.B., S.R.S., T.E.).
  • 4 German Centre for Cardiovascular Research (DZHK), partner site North (C.S.B., S.R.S., T.E.).
  • 5 Phénotypage du petit animal, Inserm UMS28, Sorbonne University-UPMC Paris 06, Inserm, Paris, France (N.M.).
  • 6 Inovarion, F-75005 Paris, France (A.F.).
  • 7 Functional Unit of Neuromuscular Pathology, Neuropathology Department, Institute of Myology, CHU Pitié-Salpêtrière, Paris, France (G.B.).
  • # Contributed equally.
PMID: 41841259 DOI: 10.1161/CIRCHEARTFAILURE.125.013806
Abstract

Background: Dilated cardiomyopathy caused by LMNA mutations is a severe cardiac condition marked by arrhythmias, contractile dysfunction, and excessive myocardial fibrosis, which collectively impair left ventricular function and increase the risk of heart failure. Although the disease has been well characterized, a lack of insight into the pathogenesis has impeded the development of therapies.

Methods: Here, we employed human induced pluripotent stem cells (hiPSCs) derived from a patient carrying a LMNA point mutation (c.665A>C, p.His222Pro), alongside a murine model carrying the same mutation, to investigate the functional and molecular abnormalities driving dilated cardiomyopathy.

Results: We demonstrated that LMNA patient-derived cardiomyocytes and engineered heart tissues exhibited elevated diastolic calcium levels and reduced sensitivity to external calcium, respectively, as well as hypocontractility. These cells also displayed nuclear shape abnormalities in 2-dimensional and 3-dimensional, a hallmark of LMNA-associated dilated cardiomyopathy, associated with disrupted chromosome spatial organization and altered gene expression profiles. Transcriptomic analysis revealed dysregulation of extracellular matrix remodeling and significant upregulation of Loxl2 in mutated hiPSC-cardiomyocytes, hiPSC-engineered heart tissues, and mice. Treatment with Simtuzumab, a Loxl2 inhibitor, effectively prevented cardiac dysfunction and fibrosis in vivo.

Conclusions: Taken together, our findings underscore the crucial role of Loxl2 as a therapeutic target and suggest that its inhibition could be a promising strategy to preserve cardiac function in LMNA-associated dilated cardiomyopathy.

Keywords

chromosomes; fibrosis; heart failure; lamins; point mutation.

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