Network Synergies in Tissue Homeostasis and Stromal Prevention of Inflammatory Disease.

Project Information

NEXUS

Grant agreement ID: 101039438

DOI

10.3030/101039438

EC signature date 16 March 2022

Start date 1 July 2022

End date 30 June 2027

Funded under

• European Research Council (ERC)

Total cost

€ 1 499 514,00

EU contribution

€ 1 499 514,00

Coordinated by

UNIVERSITATSKLINIKUM ERLANGEN
Germany

Periodic Reporting for period 1 - NEXUS (Network Synergies in Tissue Homeostasis and Stromal Prevention of Inflammatory Disease.)

Reporting period: 2022-07-01 to 2024-12-31

Summary of the context and overall objectives of the project

The NEXUS project aims to unravel a fundamental yet largely unexplored aspect of tissue biology: the role of stromal networks in maintaining homeostasis and preventing inflammation.

At its core, NEXUS proposes that tissues are not passive recipients of inflammatory processes, but active participants in controlling their own fate through a complex system of intercellular communication and coordination. The concept of the "homeostat" is central to NEXUS. In biology, a homeostat refers to any self-regulating system that maintains stability through feedback mechanisms. NEXUS posits that the stroma - the connective tissue underlying organs - functions as a sophisticated homeostat, constantly sensing and responding to perturbations to maintain tissue health. This stromal homeostat is hypothesized to be a vast, interconnected network of cells that facilitates rapid information exchange and coordinates tissue-wide responses to stress.

The overall objective of NEXUS is to characterize this stromal homeostat in unprecedented detail, from its structural organization to its functional dynamics in health and disease. By combining cutting-edge intravital imaging techniques with advanced computational analysis, NEXUS aims to:
1) Map the spatial organization of stromal networks and resident tissue macrophages in various tissues.
2) Visualize and quantify real-time communication within these networks.
3) Elucidate the role of gap junction-mediated connectivity in maintaining tissue homeostasis.
4) Investigate how the stromal homeostat responds to acute and chronic stressors, including aging.
5) Determine how disruptions in stromal network function contribute to inflammatory diseases.

The expected impact of NEXUS is multifaceted and far-reaching. By providing a comprehensive understanding of how tissues actively maintain their own health, NEXUS has the potential to revolutionize our approach to treating inflammatory and age-related diseases. Currently, most treatments focus on suppressing inflammation once it has already begun. NEXUS, however, aims to identify ways to strengthen tissues' intrinsic ability to prevent inflammation from occurring in the first place. This paradigm shift could lead to entirely new therapeutic strategies that target the stromal homeostat to enhance tissue resilience. Such approaches could be particularly impactful in chronic inflammatory conditions like rheumatoid arthritis or psoriasis, where maintaining remission is a significant challenge. Moreover, by elucidating the role of stromal networks in aging, NEXUS could open new avenues for promoting healthier aging and reducing age-related inflammatory conditions. The significance of NEXUS extends beyond specific diseases. By changing our understanding of tissue biology and the origins of inflammation, it has the potential to impact a wide range of medical fields, where understanding and manipulating the tissue microenvironment is crucial.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

In the first reporting period, the NEXUS project has made significant progress in developing novel approaches to study stromal network communication and its role in tissue homeostasis and inflammation. Our main achievements represent a significant step forward, as we have developed important methodological and analytical tools to study current network communication in depth. Key achievements include:

1) Establishment of an ex vivo tissue imaging platform ("StromaScope"):We developed a custom ex vivo tissue imaging incubator allowing precise control of environmental parameters and access for micromanipulation of intact tissue samples under a 2-photon microscope. This overcomes limitations of intravital imaging and provides a stable setup for high-resolution live imaging of stromal tissues.

2) Computational pipeline for morphodynamic analysis: We developed a computational approach to extract and analyse morphodynamic data from live imaging of tissue macrophages. This allows fine-tuning of ex vivo culture conditions to maintain naïve macrophage phenotypes.

3) 3D network architecture analysis: We created a novel image analysis method to extract and represent the 3D network architecture of interconnected stromal cells. By encoding cells as nodes and connections as edges, we can visualise and analyse tissue structure as a graph network. This enables advanced computational analysis of tissue organisation.

4) Mapping of steady-state network structure and activity: We captured baseline network structure and communication activity in healthy peritoneal tissues, providing a crucial blueprint to compare against in perturbation experiments.

5) Initiation of network perturbation studies: We began experiments to disrupt stromal networks using sterile needle injections and inflammatory peritonitis models. These studies will assess how network structure and function are altered by physical damage or inflammation.

6) Presentation of network analysis approach: Our novel method for representing tissue architecture as network graphs has generated significant interest. It was presented at several international conferences, including the Dutch Society of Immunology annual meeting and the EMBO workshop "Imaging the Immune System".

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The NEXUS project has yielded results that significantly advance our understanding of tissue biology and inflammation beyond the current state of the art. By developing novel imaging and analysis techniques, the project is providing unprecedented insights into the structure and function of stromal networks in living tissues. Key findings so far include

1) Development of a novel ex vivo tissue imaging platform ("StromaScope") that allows precise control of environmental parameters and micromanipulation of intact tissue samples under a 2-photon microscope. This overcomes limitations of intravital imaging and enables high-resolution live imaging of stromal tissues.

2) Creation of a computational pipeline for morphodynamic analysis of live imaging data from tissue macrophages. This allows quantification of cellular behaviors and communication dynamics in situ.

3) Development of a new image analysis method to extract and represent 3D network architecture of interconnected stromal cells as graph networks. This enables advanced computational analysis of tissue organization.

4) Mapping of baseline network structure and communication activity in healthy peritoneal tissues, providing a blueprint for comparison in perturbation experiments.

These results have revealed that stromal tissues could function as sophisticated homeostats, actively regulating tissue health and inflammatory responses through coordinated cellular communication.

To ensure further uptake and success of these findings, several key needs have also been identified:

1) We need to explain to what extent network structures and network communication are actually important for tissue homeostasis in vivo and what influence they have on inflammation onset or healing processes.

2) Additional research is required to fully elucidate the molecular mechanisms underlying stromal network communication and to translate these findings to human tissues.

3) Demonstration of the therapeutic potential of targeting stromal networks in inflammatory diseases will be crucial for later clinical translation.

4) Commercialization opportunities may arise from the development of new imaging tools or therapeutic strategies targeting stromal networks.

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