#	Pagina
attuale pagina	/open-h2020/projects/199740/results.html

Report

Teaser, summary, work performed and final results

Periodic Reporting for period 2 - REPROGRAM (Targeting epigenetic REPROGRamming of innate immune cells in Atherosclerosis Management and other chronic inflammatory diseases)

Teaser

Summary

Up to 70% of cardiovascular events are not prevented by current therapeutic regimens. In search for additional, innovative strategies, immune cells have been recognized as key players contributing to atherosclerotic plaque progression and destabilization. Particularly the role of innate immune cells is of major interest, following the recent paradigm shift that innate immunity, considered to be incapable of learning ability, does exhibit a memory feature transduced via epigenetic modulation. Compelling evidence shows that atherosclerotic factors promote immune cell migration by pre-activation of innate immune cells. In this project called REPROGRAM, we aim to prove that innate immune cell activation via epigenetic reprogramming perpetuates the upheld systemic inflammatory state in cardiovascular disease which is common in other chronic inflammatory diseases.

The objectives of the REPROGRAM project:
1. To unravel the molecular mechanisms through which systemic risk factors for cardiovascular disease elicit trained immunity of innate immune cells, focussing on monocytes, macrophages and hematopoietic stem and progenitor cells.
2. To assess the relevance of trained immunity as a common mechanism for the development of disease-specific pathophysiology, and its role in the development of co-morbidities in both women and men.
3. To investigate the role of trained immunity in atherosclerotic cardiovascular disease and chronic inflammatory disease.
4. To evaluate whether modulation of trained immunity will lead to a reduction of the pro-inflammatory state both in atherosclerosis and chronic inflammatory disease, offering innovative immune-modulatory therapeutic strategies.

Work performed

In WP2 we first evaluated the nature and persistence of epigenetic changes induced by atherosclerosis or acute CV-events on the innate immune system and atherogenesis. As a continuation of previous experiments, where the effect of hypercholesterolemia on hematopoietic stem cells and mature myeloid cells was investigated. Furthermore, we continued to investigate the effects of deletion of important histone modifying enzymes such as jmjd1, jmjd3 and ezh2 on monocyte and macrophage phenotype and function. In the last part of WP2 we screened a library of 40 compounds for the capacity of these compounds to reprogram histones in macrophages and thereby affect macrophage function. In addition to this approach, we decided to develop specific small molecule inhibitors directed to CD40-TRAF6 interactions, an interaction crucial to induce macrophage activation in atherosclerotic CVD. The CD40-TRAF6 SMI (patented) was able to successfully reduce macrophage activation and atherosclerosis.

In WP3 we aim to decipher how atherogenic risk factors induce a pro-atherogenic phenotype in human innate immune cells and its progenitors. Till now we have been able to identify many atherogenic factors that can induce trained innate immunity in isolated human monocytes. We have identified various metabolic and epigenetic pathways that regulate this immune memory and provide potential leads for novel drugs to temper persistent immune cell activation. Subsequently we aimed to translate these findings to patients with atherosclerosis or risk factors for atherosclerosis and to evaluate immune cell phenotype in circulating myeloid cells and progenitor cells in the bone marrow and correlate these to vascular wall inflammation as determined by nuclear imaging. We have been able to finalize the deep immunological phenotyping of different patient cohorts. In various groups, we observed monocyte activation.

Significant progress has been made on all key-objectives defined in WP4. In the first period, we identified a list of SNPs which correlated with trained immunity in monocytes in healthy volunteers. We assessed the predictive value of this â€˜epigeneticâ€™ gene risk score on CV-risk in the general population (Copenhagen General Population Study). Of the SNPs associated with trained immunity, none were convincingly associated with CVD-risk. We subsequently evaluated DNA-methylation, which is a more stable sign of epigenetic changes. We also addressed the reversibility of epigenetic remodeling by lowering of â€˜traditionalâ€™ lipid risk factors in relation to inflammatory activity, assessed as plasma cytokines, immune cell phenotype of circulating cells and vascular wall inflammation. In various patient cohorts, we substantiated a multi-level pro-inflammatory state, ranging from all the way from bone-marrow, plasma immune cells to the arterial wall. In subsequent intervention studies, we were able to unravel the differential regulation of immune cell activation on various target levels. Furthermore we initiated a clinical study to address the impact of an epigenetic modulator on inflammatory activity in humans (oral methylbutyrate intake). In parallel, we initiated a clinical study to investigate the impact of the bromodomain inhibitor (RVX-208) on the inflammatory state in patients.

Monocytes and macrophages play a central role in the pathophysiology of inflammation, as well as in atherosclerosis (WP5). They have been found to be activated in rheumatoid arthritis (RA), to massively infiltrate synovial tissues and produce tumour necrosis factor-alfa (TNF-alfa). Similarly, in atherosclerosis, macrophages are activated and produce TNF-alfa. Accordingly, therapies aimed at blocking this cytokine have emerged as a major tool in the treatment of RA. In peripheral blood monocytes from RA patients, it has been shown by others that TNF-alfa and IL6 genes display no signs of increased H3K4me3 in circulating monocytes from untreated RA patients. We could confirm this

Final results

Expected results until the end of the project
New epigenetic modulating therapies for the treatment of atherosclerosis and other chronic inflammatory diseases, combined with new mechanistic insights, will have a durable effect on improving treatment effects, life expectancy, quality of life, and avoiding unnecessary treatments. Thereby, by targeting trained immunity from a broader disease perspective in terms of a potential common mechanism for several non-communicable diseases (such as rheumatoid arthritis), the window of opportunity can be even greater by the execution of a innovative project like the REPROGRAM project.

Potential impact
The REPROGRAM project attempts to dissect novel disease pathways and treatment options under alternative research programs in cooperation with biotech and pharmaceutical companies. The generated knowledge will also provide clues to the biology of ageing as exemplified by the age-associated variation of expression of distinct biomarkers. The epidemiological analysis of these molecular markers in large population cohorts will enable to compare patients of different sexes and ages and to reveal ageing-related pathophysiological changes. Thus, the REPROGRAM project would constitute a major societal advancement in addressing the health and well-being of the European population, especially (but not only) in the quality of life of the increasing proportion of older persons prone to these debilitating diseases.