1. Myosins and MyomiR Network in Patients with Obstructive Hypertrophic Cardiomyopathy.
- Author
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Foglieni, Chiara, Lombardi, Maria, Lazzeroni, Davide, Zerboni, Riccardo, Lazzarini, Edoardo, Bertoli, Gloria, Pisano, Annalinda, Girolami, Francesca, Andolfo, Annapaola, Magagnotti, Cinzia, Peretto, Giovanni, Sartorio, Carmem L., Olivotto, Iacopo, La Canna, Giovanni, Alfieri, Ottavio, Rimoldi, Ornella E., Barile, Lucio, d'Amati, Giulia, and Camici, Paolo G.
- Subjects
HYPERTROPHIC cardiomyopathy ,MYOSIN ,SOX transcription factors ,RNA sequencing ,MASS spectrometry ,CARDIAC contraction ,GENE ontology - Abstract
Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiomyopathy. The molecular mechanisms determining HCM phenotypes are incompletely understood. Myocardial biopsies were obtained from a group of patients with obstructive HCM (n = 23) selected for surgical myectomy and from 9 unused donor hearts (controls). A subset of tissue-abundant myectomy samples from HCM (n = 10) and controls (n = 6) was submitted to laser-capture microdissection to isolate cardiomyocytes. We investigated the relationship among clinical phenotype, cardiac myosin proteins (MyHC6, MyHC7, and MyHC7b) measured by optimized label-free mass spectrometry, the relative genes (MYH7, MYH7B and MYLC2), and the MyomiR network (myosin-encoded microRNA (miRs) and long-noncoding RNAs (Mhrt)) measured using RNA sequencing and RT-qPCR. MyHC6 was lower in HCM vs. controls, whilst MyHC7, MyHC7b, and MyLC2 were comparable. MYH7, MYH7B, and MYLC2 were higher in HCM whilst MYH6, miR-208a, miR-208b, miR-499 were comparable in HCM and controls. These results are compatible with defective transcription by active genes in HCM. Mhrt and two miR-499-target genes, SOX6 and PTBP3, were upregulated in HCM. The presence of HCM-associated mutations correlated with PTBP3 in myectomies and with SOX6 in cardiomyocytes. Additionally, iPSC-derived cardiomyocytes, transiently transfected with either miR-208a or miR-499, demonstrated a time-dependent relationship between MyomiRs and myosin genes. The transfection end-stage pattern was at least in part similar to findings in HCM myectomies. These data support uncoupling between myosin protein/genes and a modulatory role for the myosin/MyomiR network in the HCM myocardium, possibly contributing to phenotypic diversity and providing putative therapeutic targets. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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