Loss of 2 Akt (Protein Kinase B) Isoforms in Hematopoietic Cells Diminished Monocyte and Macrophage Survival and Reduces Atherosclerosis in Ldl Receptor-Null Mice

An atlas of genetic scores to predict multi-omic traits

The use of omic modalities to dissect the molecular underpinnings of common diseases and traits is becoming increasingly common. But multi-omic traits can be genetically predicted, which enables highly cost-effective and powerful analyses for studies that do not have multi-omics1. Here we examine a large cohort (the INTERVAL study2; n = 50,000 participants) with extensive multi-omic data for plasma proteomics (SomaScan, n = 3,175; Olink, n = 4,822), plasma metabolomics (Metabolon HD4, n = 8,153), serum metabolomics (Nightingale, n = 37,359) and whole-blood Illumina RNA sequencing (n = 4,136), and use machine learning to train genetic scores for 17,227 molecular traits, including 10,521 that reach Bonferroni-adjusted significance. We evaluate the performance of genetic scores through external validation across cohorts of individuals of European, Asian and African American ancestries. In addition, we show the utility of these multi-omic genetic scores by quantifying the genetic control of biological pathways and by generating a synthetic multi-omic dataset of the UK Biobank3 to identify disease associations using a phenome-wide scan. We highlight a series of biological insights with regard to genetic mechanisms in metabolism and canonical pathway associations with disease; for example, JAK-STAT signalling and coronary atherosclerosis. Finally, we develop a portal ( https://www.omicspred.org/ ) to facilitate public access to all genetic scores and validation results, as well as to serve as a platform for future extensions and enhancements of multi-omic genetic scores.

The Chinese medicine Fufang Zhenzhu Tiaozhi capsule protects against atherosclerosis by suppressing EndMT via modulating Akt1/β-catenin signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Fufang Zhenzhu Tiaozhi (FTZ) is a traditional Chinese herbal prescription that has been used to treat dyslipidemia, nonalcoholic fatty liver disease, atherosclerosis, diabetes and its complications in the clinic for almost ten years. Endothelial-mesenchymal transition (EndMT) is the key driver of atherosclerosis. However, the effects of FTZ on endothelial dysfunction and EndMT remain unknown.

AIM OF THE STUDY

To evaluate the therapeutic effects of FTZ against EndMT and the underlying mechanisms.

MATERIALS AND METHODS

An in vivo model of atherosclerosis was established by feeding ApoE^-/- mice with a high-fat diet (HFD). The body weight, lipid levels, plaque area, lipid deposition and EndMT were evaluated using standard assays 12 weeks after intragastric administration of FTZ and simvastatin. Human umbilical vein endothelial cells (HUVECs) were treated with oxidized low-density lipoprotein (ox-LDL) to simulate EndMT in vitro. The degree of EndMT was assessed after treating the cells with FTZ or transfection with si-Akt1. The expression levels of genes involved in EndMT were quantified by real-time PCR or western blotting.

RESULTS

FTZ ameliorated dyslipidemia and endothelial dysfunction in the atherosclerotic mice. In addition, FTZ reduced body weight and the total cholesterol, triglycerides and low-density lipoprotein levels, and increased that of high-density lipoproteins. FTZ also upregulated the expression of endothelial markers (CD31 and VE-cadherin) and decreased that of mesenchymal markers (ɑ-SMA and FSP1), indicating that it inhibits EndMT. Knocking down Akt1 exacerbated EndMT and reversed the therapeutic effect of FTZ.

CONCLUSION

FTZ delayed atherosclerosis by inhibiting EndMT via the Akt1/β-catenin pathway.

PI3K regulates the activation of NLRP3 inflammasome in atherosclerosis through part-dependent AKT signaling pathway

PI3K is a downstream target of multiple cell-surface receptors, which acts as a crucial modulator of both cell polarization and survival. PI3K/AKT signaling pathway is commonly involved in cancer, atherosclerosis, and other diseases. However, its role in cardiovascular diseases, especially in atherosclerosis, remains to be further investigated. To determine the effect of PI3K/AKT signaling pathway on cellular inflammatory response and oxidative stress, PI3K inhibitor (GDC0941) and AKT inhibitor (MK2206) were used. First, THP-1 cells were incubated with ox-LDL (100 µg/ml) to establish an in vitro atherosclerosis model. The inflammatory factors and foam cell formation were then evaluated to ascertain and compare the effects of PI3K and AKT inhibition. ApoE^−/− mice fed a high-fat diet were used to assess the roles of PI3K and AKT in aortic plaque formation. Our results showed that the inhibition of PI3K or AKT could suppress the activation of NLRP3, decreased the expression levels of p-p65/p65 and reduced the production of mitochondrial reaction oxygen species (mitoROS) in THP-1 cells. Inhibition of PI3K or AKT could also reduced atherosclerosis lesion and plaque area, and decreased the levels of NLRP3 and IL-1β in ApoE^−/− mice. The effect of PI3K inhibition was more significant than AKT. Therefore, PI3K inhibition can retard the progress of atherosclerosis. Besides, there may be other AKT-independent pathways that regulate the formation of atherosclerosis.

The Role of Ubiquitin E3 Ligase in Atherosclerosis

Atherosclerosis is a chronic inflammatory vascular disease. Atherosclerotic cardiovascular disease is the main cause of death in both developed and developing countries. Many pathophysiological factors, including abnormal cholesterol metabolism, vascular inflammatory response, endothelial dysfunction and vascular smooth muscle cell proliferation and apoptosis, contribute to the development of atherosclerosis and the molecular mechanisms underlying the development of atherosclerosis are not fully understood. Ubiquitination is a multistep post-translational protein modification that participates in many important cellular processes. Emerging evidence suggests that ubiquitination plays important roles in the pathogenesis of atherosclerosis in many ways, including regulation of vascular inflammation, endothelial cell and vascular smooth muscle cell function, lipid metabolism and atherosclerotic plaque stability. This review summarizes important contributions of various E3 ligases to the development of atherosclerosis. Targeting ubiquitin E3 ligases may provide a novel strategy for the prevention of the progression of atherosclerosis.

HDAC1 promotes artery injury through activation of VAV3 by binding to miR-182-5p in atherosclerotic mice model

Atherosclerosis (AS) is one of the significant chronic inflammatory pathology considering public health impact. Up-regulation of HDAC1 has been proved to be related with endothelial dysfunction which is correlated intimately with AS. Our research aims to investigate how histone deacetylase 1 (HDAC1)/miR-182-5p/vav guanine nucleotide exchange factor 3 (VAV3)/AKT axis participates in AS in terms of molecular mechanism. We detected miR-181-5p in human umbilical vein endothelial cells after treatment with aorta and ox-LDL in AS model mice. Dual luciferase reporter assay was employed to verify interaction of miR-182-5p and VAV3. ChIP was performed to determine the relationship between HDAC1 and promoter of miR-182-5p. Protein levels of HADC1, VAV3, AKT, p-AKT, vascular cell adhesion molecule-1 (VCAM-1), intercellular cell adhesion molecule-1 (ICAM-1), and monocyte chemotactic protein 1 (MCP-1) were detected by western blot analysis. CCK8 and flow cytometry were used to detect cell viability and apoptosis, respectively. After different treatments, the ability of cells to form monoclonal cells was detected, and AS was evaluated by detecting arterial injury and inflammation-related factors. Overexpression of HDAC1 could inhibit HUVECs proliferation and promote AS in mouse model. It was verified by dual luciferase assay that miR-182-5p could bind to VAV3 3'UTR mRNA. Meanwhile, HDAC1 repressed miR-182-5p expression through binding to miR-182-5p promoter and then inhibit VAV3 expression further. In summary, HDAC1 promoted AS through AKT pathway, which was improved by VAV3 activation mediated by miR-182-5p. Our results demonstrated that HDAC1 repressed miR-182-5p and activating AKT pathway via improving VAV3 to promote AS progression.

Macrophage Biology in Cardiovascular Diseases

Macrophages have a key functional role in the pathogenesis of various cardiovascular diseases, such as atherosclerosis and aortic aneurysms. Their accumulation within the vessel wall leads to sustained local inflammatory responses characterized by secretion of chemokines, cytokines, and matrix protein degrading enzymes. Here, we summarize some recent findings on macrophage contribution to cardiovascular disease. We focus on the origin, survival/death, and phenotypic switching of macrophages within vessel walls.

Clinical approach to the inflammatory etiology of cardiovascular diseases

Inflammation is an obligatory marker of arterial disease, both stemming from the inflammatory activity of cholesterol itself and from well-established molecular mechanisms. Raised progenitor cell recruitment after major events and clonal hematopoiesis related mechanisms have provided an improved understanding of factors regulating inflammatory phenomena. Trials with inflammation antagonists have led to an extensive evaluation of biomarkers such as the high sensitivity C reactive protein (hsCRP), not exerting a causative role, but frequently indicative of the individual cardiovascular (CV) risk. Aim of this review is to provide indication on the anti-inflammatory profile of agents of general use in CV prevention, i.e. affecting lipids, blood pressure, diabetes as well nutraceuticals such as n-3 fatty acids. A crucial issue in the evaluation of the benefit of the anti-inflammatory activity is the frequent discordance between a beneficial activity on a major risk factor and associated changes of hsCRP, as in the case of statins vs PCSK9 antagonists. In hypertension, angiotensin converting enzyme inhibitors exert an optimal anti-inflammatory activity, vs the case of sartans. The remarkable preventive activity of SLGT-2 inhibitors in heart failure is not associated with a clear anti-inflammatory mechanism. Finally, icosapent ethyl has been shown to reduce the CV risk in hypertriglyceridemia, with a 27 % reduction of hsCRP. The inflammation-based approach to arterial disease has considerably gained from an improved understanding of the clinical diagnostic strategy and from a better knowledge on the mode of action of numerous agents, including nutraceuticals.

Akt Signaling in Macrophage Polarization, Survival, and Atherosclerosis

The PI3K/Akt pathway plays a crucial role in the survival, proliferation, and migration of macrophages, which may impact the development of atherosclerosis. Changes in Akt isoforms or modulation of the Akt activity levels in macrophages significantly affect their polarization phenotype and consequently atherosclerosis in mice. Moreover, the activity levels of Akt signaling determine the viability of monocytes/macrophages and their resistance to pro-apoptotic stimuli in atherosclerotic lesions. Therefore, elimination of pro-apoptotic factors as well as factors that antagonize or suppress Akt signaling in macrophages increases cell viability, protecting them from apoptosis, and this markedly accelerates atherosclerosis in mice. In contrast, inhibition of Akt signaling by the ablation of Rictor in myeloid cells, which disrupts mTORC2 assembly, significantly decreases the viability and proliferation of blood monocytes and macrophages with the suppression of atherosclerosis. In addition, monocytes and macrophages exhibit a threshold effect for Akt protein levels in their ability to survive. Ablation of two Akt isoforms, preserving only a single Akt isoform in myeloid cells, markedly compromises monocyte and macrophage viability, inducing monocytopenia and diminishing early atherosclerosis. These recent advances in our understanding of Akt signaling in macrophages in atherosclerosis may have significant relevance in the burgeoning field of cardio-oncology, where PI3K/Akt inhibitors being tested in cancer patients can have significant cardiovascular and metabolic ramifications.