Overexpressed lncRNA ROR Promotes the Biological Characteristics of ox-LDL-Induced HUVECs via the let-7b-5p/HOXA1 Axis in Atherosclerosis

siLOXL2 Inhibits Endothelial Inflammatory Response and EndMT Induced by ox-LDL

INTRODUCTION

Our research aimed to investigate the potential role and mechanism of lysyl oxidase (LOX)-like 2 (LOXL2) in atherosclerosis (AS) by using the human umbilical vein endothelial cells (HUVECs) stimulated by oxidized low-density lipoprotein (ox-LDL).

METHODS

HUVECs were treated with ox-LDL at different concentrations (0, 10, 25, 50, and 100 μg/mL) and incubated for 24 h. The transfection efficacy of siLOXL2 was investigated by Western blot and real-time quantitative polymerase chain reaction (RT-qPCR). Cell migration, intracellular ROS measurement, oxidative stress, enzyme-linked immunosorbent assay, and adhesion assays were carried out to examine the ox-LDL-induced HUVECs injury. RT-qPCR and Western blot were used to determine gene and protein expression levels.

RESULTS

LOXL2 protein expression increased in ox-LDL-induced endothelial cells (ECs). ox-LDL + siLOXL2 significantly inhibited the migration ability of HUVECs and reduced the expression of vascular endothelial growth factor A (VEGFA) and matrix metalloproteinase 9 gene expressions (all, p < 0.05). The ox-LDL + siLOXL2 significantly reduced intracellular ROS production and inhibited the expression of Malondialdehyde, whereas it markedly enhanced superoxide dismutase and catalase (all, p < 0.05). Supernatant levels of interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) were significantly attenuated by the ox-LDL + siLOXL2 treatment (all, p < 0.05). ox-LDL + siLOXL2 markedly suppressed the expression of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 (all, p < 0.05). ox-LDL + siLOXL2 treatment remarkably reduced the expression of α-smooth muscle actin and vimentin, while increased CD31 and von Willebrand factor gene expression (all, p < 0.05).

CONCLUSION

LOXL2 silencing is protected against ox-LDL-induced EC dysfunction, and the mechanism may be related to the inhibition of the EndMT pathway.

A Review of MicroRNAs and lncRNAs in Atherosclerosis as Well as Some Major Inflammatory Conditions Affecting Atherosclerosis

It is generally accepted that atherosclerosis is a chronic inflammatory disease. The link between atherosclerosis and other inflammatory diseases such as psoriasis, type 2 diabetes mellitus (T2DM), and rheumatoid arthritis (RA) via metabolic, inflammatory, and immunoregulatory pathways is well established. The aim of our review was to summarize the associations between selected microRNAs (miRs) and long non-coding RNAs (lncRNAs) and atherosclerosis, psoriasis, T2DM, and RA. We reviewed the role of miR-146a, miR-210, miR-143, miR-223, miR-126, miR-21, miR-155, miR-145, miR-200, miR-133, miR-135, miR-221, miR-424, let-7, lncRNA-H19, lncRNA-MEG3, lncRNA-UCA1, and lncRNA-XIST in atherosclerosis and psoriasis, T2DM, and RA. Extracellular vesicles (EVs) are a method of intracellular signal transduction. Their function depends on surface expression, cargo, and the cell from which they originate. The majority of the studies that investigated lncRNAs and some miRs had relatively small sample sizes, which limits the generalizability of their findings and indicates the need for more research. Based on the studies reviewed, miR-146a, miR-155, miR-145, miR-200, miR-133, and lncRNA-H19 are the most promising potential biomarkers and, possibly, therapeutic targets for atherosclerosis as well as T2DM, RA, and psoriasis.

Deciphering the emerging landscape of HOX genes in cardiovascular biology, atherosclerosis and beyond (Review)

Atherosclerosis, a dominant driving force underlying multiple cardiovascular events, is an intertwined and chronic inflammatory disease characterized by lipid deposition in the arterial wall, which leads to diverse cardiovascular problems. Despite unprecedented advances in understanding the pathogenesis of atherosclerosis and the substantial decline in cardiovascular mortality, atherosclerotic cardiovascular disease remains a global public health issue. Understanding the molecular landscape of atherosclerosis is imperative in the field of molecular cardiology. Recently, compelling evidence has shown that an important family of homeobox (HOX) genes endows causality in orchestrating the interplay between various cardiovascular biological processes and atherosclerosis. Despite seemingly scratching the surface, such insight into the realization of biology promises to yield extraordinary breakthroughs in ameliorating atherosclerosis. Primarily recapitulated herein are the contributions of HOX in atherosclerosis, including diverse cardiovascular biology, knowledge gaps, remaining challenges and future directions. A snapshot of other cardiovascular biological processes was also provided, including cardiac/vascular development, cardiomyocyte pyroptosis/apoptosis, cardiac fibroblast proliferation and cardiac hypertrophy, which are responsible for cardiovascular disorders. Further in‑depth investigation of HOX promises to provide a potential yet challenging landscape, albeit largely undetermined to date, for partially pinpointing the molecular mechanisms of atherosclerosis. A plethora of new targeted therapies may ultimately emerge against atherosclerosis, which is rapidly underway. However, translational undertakings are crucially important but increasingly challenging and remain an ongoing and monumental conundrum in the field.

HOXA1 participates in VSMC-to-macrophage-like cell transformation via regulation of NF-κB p65 and KLF4: a potential mechanism of atherosclerosis pathogenesis

BACKGROUND

Macrophage-like transformation of vascular smooth muscle cells (VSMCs) is a risk factor of atherosclerosis (AS) progression. Transcription factor homeobox A1 (HOXA1) plays functional roles in differentiation and development. This study aims to explore the role of HOXA1 in VSMC transformation, thereby providing evidence for the potential mechanism of AS pathogenesis.

METHODS

High fat diet (HFD)-fed apolipoprotein E knockout (ApoE^-/-) mice were applied as an in vivo model to imitate AS, while 1-palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphocholine (POV-PC)-treated VSMCs were applied as an in vitro model. Recombinant adeno-associated-virus-1 (AAV-1) vectors that express short-hairpin RNAs targeting HOXA1, herein referred as AAV1-shHOXA1, were generated for the loss-of-function experiments throughout the study.

RESULTS

In the aortic root of AS mice, lipid deposition was severer and HOXA1 expression was higher than the wide-type mice fed with normal diet or HFD. Silencing of HOXA1 inhibited the AS-induced weight gain, inflammatory response, serum and liver lipid metabolism disorder and atherosclerotic plaque formation. Besides, lesions from AS mice with HOXA1 knockdown showed less trans-differentiation of VSMCs to macrophage-like cells, along with a suppression of krüppel-like factor 4 (KLF4) and nuclear factor (NF)-κB RelA (p65) expression. In vitro experiments consistently confirmed that HOXA1 knockdown suppressed lipid accumulation, VSMC-to-macrophage phenotypic switch and inflammation in POV-PC-treated VSMCs. Mechanism investigations further illustrated that HOXA1 transcriptionally activated RelA and KLF4 to participate in the pathological manifestations of VSMCs.

CONCLUSIONS

HOXA1 participates in AS progression by regulating VSMCs plasticity via regulation of NF-κB p65 and KLF4. HOXA1 has the potential to be a biomarker or therapeutic target for AS.

Long non-coding RNA PVT1 regulates atherosclerosis progression via the microRNA-106b-5p/ACSL4 axis

Long non-coding RNAs (lncRNAs) have been associated with atherosclerosis (AS), but the role of lncRNA PVT1 in this disease is still unknown. However, lncRNA PVT1 was found to be significantly upregulated in the serum of AS patients. In vitro experiments using human vascular endothelial cells (HUVECs) showed that oxidized low-density lipoprotein (ox-LDL) treatment enhanced PVT1 expression and impeded HUVEC proliferation, which could be reversed by PVT1 knockdown or miR-106b-5p mimics. Additionally, knockdown of PVT1 and overexpression of miR-106b-5p inhibited the increase of iron content, MDA level, lipid ROS, ACSL4, and PTGS2 in ox-LDL-induced HUVECs, as well as the decrease of GSH and GPX4. We also found that PVT1 knockdown reduced lipid deposition, atherosclerotic plaque number, and size in ApoE^-/- mice. These results suggest that PVT1 plays a crucial role in AS progression by regulating the miR-106b-5p/ACSL4 axis in HUVECs, and may therefore be a potential therapeutic target for AS.

Homeobox A9 is a novel mediator of vascular smooth muscle cell phenotypic switching and proliferation by regulating methyl-CpG binding protein 2

Aberrant proliferation and phenotypic switching of vascular smooth muscle cells (VSMCs) are considered to be the main pathological processes of atherosclerotic plaque formation. Methyl-CpG binding protein 2 (MECP2) affects cell differentiation via modulating VSMC-specific gene expression and acts as a driver for the development of atherosclerosis (AS). Here, we aimed to elucidate (Rafieian-Kopaei et al., 2014 [1]) the role of homeobox A9 (HOXA9) on aberrant VSMCs upon injury or AS, and (Rana et al., 2021 [2]) whether HOXA9-mediated VSMC injury was associated with MECP2. Adeno-associated virus serotype 8-mediated knockdown of HOXA9 rescued aortic pathological injury of apolipoprotein E-deficient (ApoE^-/-) mice fed a high-fat diet (HFD), characterized by the reduction of lipid accumulation and foam cell formation. Further in vitro evidence suggested that proliferation and migration of primary mouse VSMCs (mVSMCs) stimulated by oxidized low-density lipoprotein (ox-LDL) were inhibited after HOXA9 silencing. In addition, HOXA9 silencing blocked VSMC phenotypic switching from contractile to a pathological synthetic state. HOXA9 overexpression caused opposite alterations in ox-LDL-stimulated mVSMCs. Mechanistically, MECP2 was transcriptionally activated by HOXA9. Forced expression of MECP2 impaired the anti-proliferation, anti-migration, and phenotypic switching abilities of HOXA9 silencing in VSMCs upon ox-LDL stimulation. Collectively, our findings reveal that the role of HOXA9 in pathological vascular remodeling may attribute to transcriptional regulation of MECP2.

lncRNA ROR and miR-125b Predict the Prognosis in Heart Failure Combined Acute Renal Failure

Objective

To elucidate the correlation between expression levels of long noncoding RNA (lncRNA) ROR and microRNA-125b (miR-125b) with the prognosis in heart failure (HF) patients combined acute renal failure (ARF).

Methods

HF patients combined ARF (n = 90) and healthy controls (n = 90) in the same period were included in our hospital from April 2016 to December 2018. Every subject was followed up for 24 months. Serum levels of lncRNA ROR and miR-125b were detected, and their expression correlation was analyzed by Pearson correlation test. Receiver operating characteristic (ROC) curves were depicted for assessing the sensitivity and specificity of lncRNA ROR and miR-125b in diagnosing HF combined ARF.

Results

lncRNA ROR was upregulated in serum of HF patients combined ARF, and its level was positively correlated to NYHA classification. miR-125b displayed an opposite trend. In serum samples of HF combined ARF, expression level of lncRNA ROR was negatively related to that of miR-125b. Diagnostic potentials of lncRNA ROR and miR-125b in HF combined ARF were confirmed by ROC curve analyses (lncRNA ROR: AUC = 0.9199, cutoff value = 5.595, sensitivity = 92.22%, and specificity = 73.33%; miR-125b: AUC = 0.8509, cutoff value = 2.290, sensitivity = 81.11%, and specificity = 74.44%). After 2-year follow-up, 16 cases were dead. Higher incidences of death and rehospitalization were observed in HF combined ARF cases expressing higher serum level of lncRNA ROR or lower level of miR-125b.

Conclusions

Serum level of lncRNA ROR is upregulated, and miR-125b is downregulated in HF patients combined ARF. Their levels are linked to NYHA classification, which can be utilized as prognostic biomarkers in HF combined ARF.