A Breath of Fresh Air(n) in Molecular Cardiology

lncRNA H19 facilitates vascular neointima formation by targeting miR-125a-3p/FLT1 axis

The aberrant proliferation and migration of vascular smooth muscle cells (VSMCs) contribute to the development of neointima formation in vascular restenosis. This study aims to explore the function of the long noncoding RNA H19 in neointima formation. A mouse carotid ligation model was established, and human vascular smooth muscle cells (VSMCs) were used as a cell model. lncRNA H19 overexpression promoted VSMC proliferation and migration. Moreover, miR-125a-3p potentially bound to lncRNA H19, and Fms-like tyrosine kinase-1 (FLT1) might be a direct target of miR-125a-3p in VSMCs. Upregulation of miR-125a-3p alleviated lncRNA H19-enhanced VSMC proliferation and migration. Furthermore, rescue experiments showed that enhanced expression of miR-125a-3p attenuated lncRNA H19-induced FLT1 expression in VSMCs. In addition, the overexpression of lncRNA H19 significantly exacerbated neointima formation in a mouse carotid ligation model. In summary, lncRNA H19 stimulates VSMC proliferation and migration by acting as a competing endogenous RNA (ceRNA) of miR-125a-3p. lncRNA H19 may be a therapeutic target for restenosis.

LncRNA-SNX17 Promotes HTR-8/SVneo Proliferation and Invasion Through miR-517a/IGF-1 in the Placenta of Diabetic Macrosomia

Gestational diabetes mellitus (GDM) has become a worldwide problem in recent years. Macrosomia, a primary consequence of GDM, has short-term and life-long consequences in the offspring of mothers with GDM. Our previous study showed that miR-517a was dysregulated in placenta and plasma of fetal growth restriction through inhibiting invasion of trophoblast and might be closely related with the regulation of birth weight by the placenta. To further investigate the mechanism of miR-517a, we conducted genome-wide microarray profile of lncRNAs. lncRNA-SNX17 was found to be significantly upregulated in the placenta of diabetic macrosomia by qRT-PCR, and the expression of miR-517a and IGF-1 were measured by qRT-PCR and Western blot. Interestingly, significant inverse correlations of the miR-517a with both lncRNA-SNX17 and IGF-1 expression were revealed in the placenta of diabetic macrosomia. Bioinformatic prediction also revealed that both lncRNA-SNX17 and IGF-1 possessed binding sites for miR-517a, which were then confirmed by luciferase report assay. LncRNA-SNX17 overexpression reduced the expression of miR-517a and increased the IGF-1 expression in HTR-8/SVneo human trophoblast cell line and thus enhanced the proliferation of HTR-8/SVneo. The enhancement of HTR-8/SVneo proliferation by lncRNA-SXN17 could be nullified by co-transfection of miR-517a mimics. The data suggested that lncRNA-SNX17 might promote the trophoblast proliferation through miR-517a/IGF-1 pathway and might play a role in the placentation of diabetic macrosomia.

RNA sequencing profiling reveals key mRNAs and long noncoding RNAs in atrial fibrillation

Long noncoding RNAs (lncRNAs) are an emerging class of RNA species that could participate in some critical pathways and disease pathogenesis. However, the underlying molecular mechanism of lncRNAs in atrial fibrillation (AF) is still not fully understood. In the present study, we analyzed RNA-seq data of paired left and right atrial appendages from five patients with AF and other five patients without AF. Based on the gene expression profiles of 20 samples, we found that a majority of genes were aberrantly expressed in both left and right atrial appendages of patients with AF. Similarly, the dysregulated pathways in the left and right atrial appendages of patients with AF also bore a close resemblance. Moreover, we predicted regulatory lncRNAs that regulated the expression of adjacent protein-coding genes (PCGs) or interacted with proteins. We identified that NPPA and its antisense RNA NPPA-AS1 may participate in the pathogenesis of AF by regulating the muscle contraction. We also identified that RP11 - 99E15.2 and RP3 - 523K23.2 could interact with proteins ITGB3 and HSF2, respectively. RP11 - 99E15.2 and RP3 - 523K23.2 may participate in the pathogenesis of AF via regulating the extracellular matrix binding and the transcription of HSF2 target genes, respectively. The close association of the lncRNA-interacting proteins with AF further demonstrated that these two lncRNAs were also associated with AF. In conclusion, we have identified key regulatory lncRNAs implicated in AF, which not only improves our understanding of the lncRNA-related molecular mechanism underlying AF but also provides computationally predicted regulatory lncRNAs for AF researchers.

Long noncoding RNA Airn protects podocytes from diabetic nephropathy lesions via binding to Igf2bp2 and facilitating translation of Igf2 and Lamb2

Diabetic nephropathy (DN) is a severe diabetic microvascular complication with high mortality. Long noncoding RNAs (lncRNAs) are characterized as important regulators of various biological processes by emerging researches, whereas the molecular mechanisms by which lncRNAs participate in DN progression need to be further clarified. Herein, we conducted a study on the regulatory role in DN of an lncRNA named antisense of Igf2r non-protein-coding RNA (Airn). Airn expression was downregulated in renal tissues of diabetic mice, and was negatively related with DN development. Besides, Airn downregulation was detected in high-glucose-stimulated podocytes, resulting in poorer cell viability, a higher tendency to cell apoptosis, and a deficiency of laminin level, while Airn overexpression could significantly alleviate these deleterious effects. Mechanistically, using RNA immunoprecipitation and RNA pull-down assays, we found that Airn could bind to the RNA-binding protein Igf2bp2, thus facilitating translation of Igf2 and Lamb2 to maintain normal podocyte viability and glomerular barrier function. Collectively, our results demonstrate the protective role of lncRNA Airn in podocytes against DN, providing a new insight into DN pathogenesis and molecular therapy.

LncRNA CRNDE regulates the proliferation and migration of vascular smooth muscle cells

Restenosis after angioplasty or stent is a major clinical problem. While long noncoding RNAs (lncRNAs) are implicated in a variety of diseases, their role in restenosis is not well understood. This study aims to investigate how dysregulated lncRNAs and messenger RNAs (mRNAs) contribute to restenosis. By microarray analysis, we identified 202 lncRNAs and 625 mRNAs (fold change > 2.0, p < 0.05) differentially expressed between the balloon-injured carotid artery and uninjured carotid artery in the rats. Among differentially expressed lncRNAs, LncRNA CRNDE had the highest fold change and the change was validated by reverse transcription polymerase chain reaction. We found that LncRNA CRNDE was significantly upregulated in injured rat carotid artery and vascular smooth muscle cells (VSMCs) stimulated by platelet-derived growth factor-BB (PDGF-BB). Knockdown of LncRNA CRNDE by small interference RNA significantly inhibited PDGF-BB stimulated proliferation and migration of VSMCs. Moreover, knockdown of LncRNA CRNDE attenuated PDGF-BB-induced phenotypic change of VSMCs. Taken together, our study reveals a novel mechanoresponsive LncRNA CRNDE which may be a therapeutic target for restenosis.