Background—: Phenotypic switching of vascular smooth muscle cells from a contractile to a synthetic state is implicated in diverse vascular pathologies, including atherogenesis, plaque stabilization, and neointimal hyperplasia. However, very little is known about the role of long noncoding RNA (lncRNA) during this process. Here, we investigated a role for lncRNAs in vascular smooth muscle cell biology and pathology. Methods and Results—: Using RNA sequencing, we identified >300 lncRNAs whose expression was altered in human saphenous vein vascular smooth muscle cells following stimulation with interleukin-1α and platelet-derived growth factor. We focused on a novel lncRNA (Ensembl: RP11-94A24.1), which we termed smooth muscle–induced lncRNA enhances replication ( SMILR ). Following stimulation, SMILR expression was increased in both the nucleus and cytoplasm, and was detected in conditioned media. Furthermore, knockdown of SMILR markedly reduced cell proliferation. Mechanistically, we noted that expression of genes proximal to SMILR was also altered by interleukin-1α/platelet-derived growth factor treatment, and HAS2 expression was reduced by SMILR knockdown. In human samples, we observed increased expression of SMILR in unstable atherosclerotic plaques and detected increased levels in plasma from patients with high plasma C-reactive protein. Conclusions—: These results identify SMILR as a driver of vascular smooth muscle cell proliferation and suggest that modulation of SMILR may be a novel therapeutic strategy to reduce vascular pathologies.

Despite the increasing importance of long noncoding RNA in physiology and disease, their role in endothelial biology remains poorly understood. Growing evidence has highlighted them to be essential regulators of human embryonic stem cell differentiation. SENCR, a vascular-enriched long noncoding RNA, overlaps the Friend Leukemia Integration virus 1 (FLI1) gene, a regulator of endothelial development. Therefore, we wanted to test the hypothesis that SENCR may contribute to mesodermal and endothelial commitment as well as in endothelial function. We thus developed new differentiation protocols allowing generation of endothelial cells from human embryonic stem cells using both directed and hemogenic routes. The expression of SENCR was markedly regulated during endothelial commitment using both protocols. SENCR did not control the pluripotency of pluripotent cells; however its overexpression significantly potentiated early mesodermal and endothelial commitment. In human umbilical endothelial cell (HUVEC), SENCR induced proliferation, migration, and angiogenesis. SENCR expression was altered in vascular tissue and cells derived from patients with critical limb ischemia and premature coronary artery disease compared to controls. Here, we showed that SENCR contributes to the regulation of endothelial differentiation from pluripotent cells and controls the angiogenic capacity of HUVEC. These data give novel insight into the regulatory processes involved in endothelial development and function.

Various human cardiovascular pathophysiological conditions associate aberrant expression of microRNAs (miRNAs) and circulating miRNAs are emerging as promising biomarkers. In mice, myocardial miR-21 overexpression is related to cardiac fibrosis elicited by pressure overload. This study was designed to determine the role of myocardial and plasmatic miR-21 in the maladaptive remodeling of the extracellular matrix induced by pressure overload in aortic stenosis (AS) patients and the clinical value of miR-21 as a biomarker for pathological myocardial fibrosis. In left ventricular biopsies from 75 AS patients and 32 surgical controls, we quantified the myocardial transcript levels of miR-21, miR-21-targets and ECM- and TGF-β-signaling-related elements. miR-21 plasma levels were determined in 25 healthy volunteers and in AS patients. In situ hybridization of miR-21 was performed in myocardial sections. The myocardial and plasma levels of miR-21 were significantly higher in the AS patients compared with the controls and correlated directly with the echocardiographic mean transvalvular gradients. miR-21 overexpression was confined to interstitial cells and absent in cardiomyocytes. Using bootstrap validated multiple linear regression, the variance in myocardial collagen expression was predicted by myocardial miR-21 (70% of collagen variance) or plasma miR-21 (52% of collagen variance), together with the miR-21 targets RECK and PDCD4, and effectors of TGF-ß signaling. Our results support the role of miR-21 as a regulator of the fibrotic process that occurs in response to pressure overload in AS patients and underscore the value of circulating miR-21 as a biomarker for myocardial fibrosis.

The effects of three temperatures (5, 15, and 25°C) on the survival ofSalmonella entericaserovar Typhimurium in topsoil were investigated in small microcosms by three different techniques: plate counting,invAgene quantification, andinvAmRNA quantification. Differences in survival were related to the effect of protozoan predation. Tetracycline-resistantSalmonellaserovar Typhimurium was inoculated into soil and manure-amended soil at 1.5 × 10⁸cells g soil⁻¹. Population densities were determined by plate counting and by molecular methods and monitored for 42 days. Simultaneous extraction of RNA and DNA, followed by quantitative PCR, was used to investigateinvAgene levels and expression. Analysis by these three techniques showed thatSalmonellaserovar Typhimurium survived better at 5°C. Comparing DNA and CFU levels, significantly higher values were determined by DNA-based techniques.invAmRNA levels showed a fast decrease in activity, with no detectable mRNA after an incubation period of less than 4 days in any of the soil scenarios. A negative correlation was found betweenSalmonella serovar Typhimurium CFU levels and protozoan most probable numbers, and we propose the role of the predator-prey interaction as a factor to explain the die-off of the introduced strain by both culture- and DNA quantification-based methods. The results indicate that temperature, manure, and protozoan predation are important factors influencing the survival ofSalmonellaserovar Typhimurium in soil.

MiR-30c-5p expression modulates pain in rodent models of nerve injury and is overexpressed in patients with neuropathic pain due to leg ischemia.