ABSTRACT
BACKGROUND: microRNAs (miRs) are small noncoding RNAs that recognize and bind to mRNAs and inhibit protein translation or degrade mRNA. Studies in animal models have suggested that miRs play a translational or posttranslational regulatory role in myocardial growth, fibrosis, viability, and remodeling. However, whether specific temporal changes in miRs occur in patients during the left ventricular (LV) remodeling process that follows a myocardial infarction (post-MI) remains unknown. The current pilot study tested the hypotheses that plasma miRs could be reliably measured in post-MI patients and that there is a relationship between temporal changes in specific miRs and post-MI LV structural remodeling. METHODS AND RESULTS: LV end-diastolic volume (echocardiography) and plasma miR were measured in age-matched referent controls (CTLs, n=12) and post-MI patients (n=12) from day 2 through day 90 post-MI. Selected miRs (miR-1, miR-21, miR-29a, miR-133a, and miR-208) were measured using quantitative reverse transcription-polymerase chain reaction and normalized for endogenous small nuclear RNA U6. After MI, LV end-diastolic volume increased progressively compared with CTL; this was accompanied by time-dependent changes in specific miRs. For example, miR-21 initially decreased 2 days post-MI (0.3 ± 0.1-fold versus CTL; P<0.05), increased 5 days post-MI (2 ± 1-fold versus CTL; P<0.05), and returned to CTL values at later post-MI time points. In contrast, miR-29a increased 5 days post-MI (4 ± 1-fold versus CTL; P<0.05) and then decreased to CTL at later time points. miR-208 increased 5 days post-MI (3 ± 1-fold versus CTL; P<0.05) and remained elevated up to 90 days post-MI. CONCLUSIONS: A time-dependent change in miRs occurred in post-MI patients, including an early and robust increase in miRs that has affected myocardial growth, fibrosis, and viability. Thus, serially profiling miRs in the plasma of post-MI patients may hold both mechanistic and prognostic significance.
Subject(s)
Heart Ventricles/physiopathology , MicroRNAs/blood , Myocardial Infarction/blood , Myocardial Infarction/physiopathology , Ventricular Remodeling , Case-Control Studies , Female , Heart Ventricles/metabolism , Humans , Male , MicroRNAs/genetics , Middle Aged , Myocardial Infarction/genetics , Pilot ProjectsABSTRACT
BACKGROUND: Chronic pressure overload (such as arterial hypertension) may cause left ventricular (LV) remodeling, alterations in cardiac function, and the development of diastolic heart failure. Changes in the composition of the myocardial extracellular matrix may contribute to the development of pressure-overload-induced LV remodeling. We hypothesized that a specific pattern of plasma biomarker expression that reflected changes in these pathophysiological mechanisms would have diagnostic application to identify (1) patients who have development of LV hypertrophy (LVH) and (2) patients with LVH who have development of diastolic heart failure. METHODS AND RESULTS: Plasma concentration of 17 biomarkers (matrix metalloproteinase [MMP]-1, -2, -3, -7, -8, and -9; tissue inhibitors -1, -2, -3, and -4; N-terminal propeptide of brain natriuretic peptide (NT-proBNP); cardiotrophin; osteopontin; soluble receptor for advanced glycation end products; collagen I teleopeptide; collagen I NT-proBNP; and collagen III N-terminal propetide [PIIINP]), an echocardiogram, and 6-minute hall walk were performed on 241 referent control subjects, 144 patients with LVH but no evidence of heart failure, and 61 patients with LVH and diastolic heart failure (DHF). A plasma multibiomarker panel consisting of increased MMP-7, MMP-9, TIMP-1, PIIINP, and NT-proBNP predicted the presence of LVH with an area under the curve of 0.80. A plasma multibiomarker panel consisting of increased MMP-2, TIMP-4, PIIINP, and decreased MMP-8 predicted the presence of DHF with an area under the curve of 0.79. These multibiomarker panels performed better than any single biomarker including NT-proBNP and better than using clinical covariates alone (area under the curve, 0.73 for LVH and 0.68 for DHF). CONCLUSIONS: Plasma biomarkers reflecting changes in extracellular matrix fibrillar collagen homeostasis, combined into a multibiomarker panel, have discriminative value in identifying the presence of structural remodeling (LVH) and clinical disease (DHF).
