# LncRNA nonnmmut065573 promotes post-myocardial infarction cardiac fibrosis and activates the TGF-β1/ZEB1 pathway

## TL;DR

This study shows that a specific long non-coding RNA promotes heart tissue scarring after a heart attack by activating a key signaling pathway.

## Contribution

Identifies LncRNA-IH as a novel driver of post-MI cardiac fibrosis through TGF-β1/ZEB1 pathway activation.

## Key findings

- LncRNA-IH overexpression in mice worsens post-MI cardiac dysfunction and fibrosis.
- LncRNA-IH enhances fibroblast proliferation and migration in vitro.
- Transcriptomic analysis links LncRNA-IH to TGF-β1 signaling pathway activation and ZEB1 upregulation.

## Abstract

Cardiac fibrosis following myocardial infarction (MI) is a critical determinant of progressive cardiac dysfunction, yet the underlying mechanisms driving this pathological process remain incompletely understood. Elucidating these regulatory pathways holds profound implications for improving post-MI prognosis.

Our prior work demonstrated that chronic intermittent hypoxia (CIH) exacerbates cardiac fibrosis while modulating the expression of long non-coding RNA (lncRNA) nonnmmut065573 (tentatively designated LncRNA-IH) in cardiac tissues. Herein, we sought to determine the role of LncRNA-IH in post-MI cardiac fibrosis and its underlying mechanisms. Using a C57BL/6 mouse model of MI, we established a mouse model with cardiac-specific overexpression of LncRNA-IH to evaluate post-MI cardiac fibrosis. In vitro, primary cardiac fibroblasts (MCF) and the PA12 cell line were subjected to LncRNA-IH overexpression or siRNA-mediated knockdown, and cell proliferation and migration were assessed. Transcriptomic profiling was performed to characterize LncRNA-IH-induced changes in cardiac gene expression and signaling pathways, aiming to elucidate the molecular mechanisms involved.

Results showed that CIH significantly exacerbated post-MI cardiac fibrosis, and LncRNA-IH was predominantly localized to cardiac fibroblasts. Cardiac-specific overexpression of LncRNA-IH in MI mice markedly exacerbated post-MI cardiac dysfunction and fibrosis. In vitro, LncRNA-IH overexpression significantly enhanced the proliferation and migration capacities of primary cardiac fibroblasts and PA12 cells, whereas these effects were abrogated by LncRNA-IH knockdown. Transcriptomic analysis revealed that LncRNA-IH elicited significant alterations in cardiac gene expression profiles, specifically activating the TGF-β1 signaling pathway and upregulating the expression of its downstream target, ZEB1.

Collectively, our findings indicate that LncRNA-IH promotes cardiac fibroblast proliferation and migration, thereby exacerbating post-MI cardiac remodeling, at least in part through activation of the TGF-β1 signaling pathway. This study identifies LncRNA-IH as a potential therapeutic target for mitigating post-MI cardiac fibrosis and preserving cardiac function.

The online version contains supplementary material available at 10.1186/s13619-025-00275-5.