Poster prizes at ‘Defining and defeating metastasis’ – meet the winners!

We are excited to present the poster prizes awarded at the recent EMBO | EMBL Symposium  ‘Defining and defeating metastasis’,  hosted at the Advanced Training Centre in Heidelberg and bringing together researchers from diverse fields to enhance our understanding of the dissemination and metastatic colonisation of tumour cells. It provided a unique opportunity for interdisciplinary exchange on current approaches and future collaborations on metastasis and its therapeutic challenges. As with most events this year, for many participants this was the first onsite meeting that they attended since early 2020 which made it very special. It was a fantastic opportunity to meet in person for the three days full of exciting science, exchanging ideas, presenting latest research, catching up with old friends and making new ones. There were two live poster sessions during which the presenters could discuss their research– their work was then voted for by other attendees and speakers. We are pleased to be able to share with you the research from four out of six winners of the conference prizes: congratulations to all!

Jagged-1 promotes breast cancer metastasis through the lymphatic system

Presenter: Benjamin Gordon

Benjamin Gordon – University of Illinois at Chicago College of Medicine, USA

While early detection of breast cancer (BC) has improved prognoses, there is an urgent need to improve outcomes for patients with distant metastatic disease. Higher expression of the Notch ligand JAG1 in primary BC tumors is strongly associated with lymph node metastasis and patient mortality, but causality is unclear. We show that JAG1 expression is higher in metastatic BC cells colonizing lymph nodes than in primary tumors, suggesting that tumor cells with high JAG1 are preferentially able to metastasize to lymph nodes. JAG1 expression is higher in a derivative of BC line MDA MB 231 selected for tropism to lymph nodes (MDA231 LN) than in the parental line or derivatives with other tropisms. To determine the mechanism(s) of JAG1 mediated metastasis, we generated clonal JAG1 knockout cell lines from MDA231 LN cells with corresponding JAG1 rescue lines. We investigated the role of JAG1 in spontaneous metastasis under clinically relevant conditions by orthotopically implanting JAG1 knockout and expressing cells, resecting the primary tumor, and following long term metastatic spread in a mouse model. Quantification of tumor cells in blood showed that survival, metastatic burden, and JAG1 expression did not correlate with the number of circulating tumor cells. Conversely, JAG1 expression drove an increase in lymph node and body wide metastatic burden and a trend toward decreased survival. In this model, metastatic cells were abundant throughout lymph vessels, suggesting lymphatics are the primarily route of dissemination. Preliminary transcriptional analysis suggests that JAG1 alters interactions with lymphatic endothelial cells (LEC), leading us to examine downstream events in co cultures of LEC with lymphatically invasive BC lines. Deciphering tumor lymphatic endothelial signaling events may open new avenues to target BC metastasis.

View the poster

Poster Prize from the EMBO Journal

Biphasic contribution of platelets to metastasis

Presenter: María J. García-León

Maria J. Garcia-Leon – INSERM UMR_S1109, Tumor Biomechanics, Université de Strasbourg, France

Metastasis still remains elusive to treatment, with an overwhelming mortality rate of 90%. Accumulating evidence indicates that metastatic potential of circulating tumor cells (CTCs) can be tuned by intravascular components, including platelets. Platelet depletion impairs metastasis, which can be rescued upon platelet transfusion. Mechanistically, CTCs rapidly bind, activate and aggregate platelets, events that are crucial for the arrest, survival, and extravasation of the former. The current dogma states that platelets tune metastasis by impacting CTCs behaviour at early stages of metastatic seeding. However, whether platelets can regulate metastasis at later stage and which receptors may be involved remains unknown. In this study, we first documented the efficiency of platelet binding to a large panel of metastatic TCs and observed that not all recruit or aggregate platelets with the same efficiency. Interestingly, such binding impacts their intravascular fate by favoring their arrest, as observed in a combination of experimental metastasis models in thrombocytopenic (TCP) mice and zebrafish embryo. Using longitudinal imaging of metastatic seeding and growth in TCP mice at unprecedented spatial and temporal resolution, we demonstrated that binding and aggregation correlates with their metastatic potential in vivo. Additionally, by the dynamic in vivo tracking of TCs in the lungs of fully TCP mice, and the quantification of platelets depositions around arrested CTCs at seeding and late metastatic outgrowth, we showed that early platelet binding, aggregation, clot formation, and the subsequent increased adhesion and survival at lung microvessels, are capital but not exclusive factors increasing TC metastatic fitness. We observed that platelets contribute to late steps of metastatic outgrowth by experimentally interfering with platelet counts in animals already carrying metastatic foci. Doing so, we observed that platelets tune the growth of established foci, independently of their early intravascular interaction with CTCs. Finally, we have identified the platelet collagen receptor GPVI as key in this late modulation of metastatic outgrowth, suggesting its targeting in specific cancer types as a promising adjuvant therapy in oncologic patients to stop the metastatic progression.

View the poster

Poster Prize from EMBO Molecular Medicine

Colonic fibroblasts in tissue homeostasis and cancer

Presenter: Michael Brügger

Michael Brügger – University of Zürich, Switzerland

Colorectal cancer (CRC) is among the most prevalent cancers in Switzerland (2nd in women 3rd in men, BFS statistics 2013 2017) and worldwide (3rd in women and men). More than half of the patients diagnosed with CRC either harbour metastases or will develop metastatic disease, which is the primary cause of death for CRC patients. There is therefore a dire need for new therapies. These must be guided by a better understanding of the metastatic process. We are only now starting to appreciate the contribution of not only tumour cells themselves, but also the non tumour stromal cells of the tumour microenvironment (TME) to tumour growth, progression and metastasis. To understand how non tumour stromal cells are changed in CRC it is integral to first characterize their identity and functions during colonic homeostasis.
To describe the stromal cell populations in an unbiased manner, we carried out a single cell transcriptome analysis of the adult murine colon, producing a high quality atlas of matched colonic epithelium and mesenchyme. We identify two crypt associated colonic fibroblast populations that are demarcated by different strengths of platelet derived growth factor receptor A (Pdgfra) expression. Crypt bottom fibroblasts (CBFs), close to the intestinal stem cells, express low levels of Pdgfra and secrete canonical Wnt ligands, Wnt potentiators, and bone morphogenetic protein (Bmp) inhibitors. Crypt top fibroblasts (CTFs) exhibit high Pdgfra levels and secrete noncanonical Wnts and Bmp ligands. While the Pdgfralow cells maintain intestinal stem cell proliferation, the Pdgfrahigh cells induce differentiation of the epithelial cells. Notably, these cell populations are conserved in the human colon.
Recently, we established a murine model of metastatic colorectal cancer, based on the orthotopic endoscopy guided injection of cancer organoids (colonic organoids harbouring mutations in APC, Kras, Tp53 and Smad4). In this context we study how the abovementioned fibroblast populations are affected by the primary tumour and how they in turn affect tumour progression.

View the poster

Single cell transcriptomic profiling of brain metastatic founders in small cell lung cancer patient derived models to identify potential vulnerabilities

Presenter: Maria Peiris-Pagès

Maria Peiris Pages – Cancer Research UK Manchester Institute, UK

Background: Brain metastasis is a major cause of patient morbidity and mortality in small cell lung cancer (SCLC) with an ~80% incidence during disease progression, contributing to the dismal 5 year survival rate of <7%. Mechanisms underpinning SCLC brain metastasis are understudied due to scarcity of brain biopsies and preclinical models. We have developed a biobank of >60 circulating tumour cell (CTC) derived patient explant models of SCLC in immunodeficient mice (CDX) where brain metastasis is routinely observed upon resection of the subcutaneous (S.C) tumour
Methods: We developed an in vivo S.C tumour resection workflow in brain tropic CDX3P to isolate single CTCs, early brain founder tumour cells and subsequent established brain metastases. Following FACS of CDX cells from dissociated mouse brain (using a human CD147 antibody) we performed single cell RNA sequencing (scRNAseq) to reveal potential molecular regulators hypothesised to support brain metastatic founding and subsequent colonisation
Results: Brain metastases were detectable in CDX3P on average 195 days after S.C implantation (study length 174 230 days). We analysed 58 single CTCs (n=6 mice, 191 230 days) and 214 brain metastatic founder cells (n=2 mice, 205 218 days) by scRNAseq. Bioinformatics analyses defined transcriptomic features underpinning single cell heterogeneity and identified sub populations within CTCs and metastatic founders indicative of brain tropic CTC sub clones. We also characterised molecular features unique to brain founders as candidates that could serve as therapy targets
Future Tissue expression of candidate genes of brain metastatic founding will be validated in CDX and patient samples. Genetic manipulation of CDX cells ex vivo combined with pharmacological approaches will be used to explore their roles in metastatic seeding and to identify potential vulnerabilities. Transcriptomic analysis of cells from established brain metastases obtained from the above in vivo protocol will be conducted to explore molecular programs of brain colonisation. Combined, these data will contribute to our long term goal of identifying novel therapeutic strategies that may ultimately improve the quality of life for the significant number of patients with SCLC who present with or subsequently develop brain lesions.

Due to the confidentiality of the unpublished data, we cannot share the poster.

Effective treatment of colorectal peritoneal metastases by exploiting a molecular subtype specific vulnerability

Presenter: Sanne Bootsma

Sanne Bootsma, Amsterdam UMC, The Netherlands

In colorectal cancer, peritoneal metastases (PMs) associate with severe morbidity and dismal prognosis. Given the incidence of this disease and the lack of adequate treatments currently available, PMs pose a large unmet clinical need. Although PMs can be accompanied by more widespread metastatic disease, it often occurs as the only sign of dissemination. This implies that the route of metastatic spread to the peritoneum differs from that to distant organs. PMs are thought to result from cancer cells that spill into the abdominal cavity, and are able to attach to the peritoneal lining and form tumor deposits. This cascade places specific demands on the cancer cells.
Here, we report that colorectal cancers that present with PMs almost universally classify as consensus molecular subtype 4 (CMS4). This previously recognized disease entity is characterized by mesenchymal features, poor prognosis, and resistance to therapies currently used against peritoneal metastases, which explains their limited efficacy. By leveraging disease models that capture CMS4 specific features, including the ability to form PMs in vivo, we identified elesclomol as a highly effective agent. Elesclomol kills cancer cells in a copper dependent fashion by targeting the oxidative phosphorylation machinery, which we found to be a specific vulnerability of CMS4 cancers. Elesclomol Cu2+ was effective following only minutes of exposure to CMS4 cell lines and organoids, supporting its use in intra abdominal treatment procedures. It is therefore a promising candidate for the local treatment of peritoneal metastases of colorectal cancer.

View the poster

Poster Prize from Metastasis Research Society


The remaining prize was:

Short talk Prize from Metastasis Research Society: Eric Rahrmann – University of Cambridge, UK


Congratulations to all six winners!

The EMBO | EMBL Symposium ‘Defining and defeating metastasis’ took place from 19 – 22 June 2022 at EMBL Heidelberg and was streamed online for virtual participants.

Meet the EMBL Events Team: Asal

Asal wears many hats in the EMBL Events team. She is our sponsorship guru, taking care of everything from raising money for our courses and conferences to working with different journals and societies for in-kind partnerships. During the pandemic, she was our technology wiz spearheading a project to find a good platform for our virtual conferences. Need any HTML help? Asal has you covered! Last but not least, she is the queen of laughter and her genuinely infectious happiness can be felt for miles (or kilometres!).

Asal Rustamova, Sponsorship and Media Partnership Manger

At EMBL since: August 2017

Number of organised conferences/courses: I do not organise conferences but since I’ve started, I have leased sponsorships for more than 80 conferences and courses at EMBL.

What is your favourite place in Heidelberg?
The EMBL Campus. When I started my work at EMBL I moved directly to Mannheim, the most time I spent in Heidelberg was at the EMBL campus and I love it. It has a very nice vibe. The EMBL campus is much more than a place for work. You feel that you belong to the community here. There are a lot of different clubs. Before the pandemic we had a lot of social activities and events. Although my commutes from Mannheim with the public transport were not always smooth, it is a nice feeling to start a day at EMBL after a nice bus ride through the forest and walk through the campus full of flowers. I am amazed of the great job of our gardeners.

What do you like most about your job? 
I love being in a scientific community. Even if I am not a scientist I have been surrounded by scientists since my childhood. In my work, I enjoy building bridges between science training at EMBL and the life science industry. I strongly believe that there are benefits for both. Corporate social responsibility is very important aspect. By providing financial support to public research institutions like EMBL, companies contribute to the advancement of basic research and positive developments in society. And companies ultimately benefit from them too. A lot of scientists who received training at EMBL follow career paths in industry. Industry also brings a lot of innovations and solutions that can help scientists in their research.

If you weren’t a Sponsorship and Media Partnership Manger, what would you be?
I wish I were an environmentalist doing some manual work outside. But after finishing my job at EMBL, I will most likely continue raising funds for non-for-profit as I was doing before I joined EMBL.

What is on your bucket list?
I have some social project ideas that I want to realize. Hopefully, I can do it when I have a bit more time.

What is your favourite book and why? 
My favourite book is always the one I am reading at that moment and I always feel a bit sad when I finish it.

What is your favourite recipe? 
I love plov. It is a national dish from my home country Uzbekistan. It is the only dish I can eat every day for weeks.

What is your favourite movie? 
I like movies by Christopher Nolan

Virtual event report on ‘Cellular mechanisms driven by phase separation’

Written by event reporter Ritvik Gupta 

The EMBO|EMBL Symposium ‘Cellular mechanisms driven by phase separation’ occurred from 9-12 May 2022. The meeting was held on-site and virtually, with a record of over 500 attendees from all over the world. Seven lucky candidates got fellowships from the EMBO and the EMBL Advanced Training Centre Corporate Partnership Programme. These candidates travelled across the globe from India, the Czech Republic, Saudi Arabia, Poland, and Spain to attend the conference. The four-day program featured seven sessions, 50 talks, discussion panels, and countless posters showcasing the newest scientific advances in the field.

It was my first time attending and reporting during a virtual conference organized by EMBO & EMBL. The meeting was scheduled systematically, with links to presentations, posters, chats, and other information provided online on the login page. Moreover, the newly added discussion tab allowed the users to meet editors, talk about articles, and get advice on how to publish them. If you want to collaborate with someone or have a career-related question, this is the right place for you! You could also raise questions that come to your mind and have a fruitful discussion with other attendees.

My virtual setup

Pre-symposium workshop

LUMICKS organized a pre-conference workshop to Unravel the Biophysical Principles Underlying Biomolecular Assemblies Using Optical Tweezers.

The revelation that various intracellular vesicles can be generated without lipid membranes has opened up new areas for research in cell biology and related domains. Transcriptional clusters, stress granules, heterochromatin domains, and DNA repair compartments are all instances of membrane-less compartments. These biomolecular assemblages enable the enrichment or exclusion of specific biomolecules, the spatial organization of nucleic acids, and the acceleration of biological events.

The panelists provided many exciting ideas from decades of expertise in their field, which is typically not readily available, particularly to early-career scientists.

Scientific sessions

The conference kicked off with opening remarks given by the scientific organizers Simon Alberti, Dorothee Dormann, Edward Lemke, and Tanja Mittag. The schedule was jam-packed with great and diverse talks covering significant aspects and hot topics in phase separation. There were seven sessions, each focussing on a different element of phase separation, thereby beautifully orchestrating a story that can helped one sequentially understand the topics and stay hooked to the presentations.

The highlights from the conference were instantly reported on Twitter using  #EESPhaseSeparation. If the data presented during a talk has already been published, there is usually a link to the tweet’s associated paper(s).


Talks and key-note lecture

Stephen Michnick (Université de Montréal, Canada)
Spoke about Saccharomyces cerevisiae and how, around 1 billion years ago, the genome of the budding yeast Saccharomyces cerevisiae underwent a significant decompaction due to the loss of histone H3 lysine 9 methylation. He explained how this decompaction could have caused a more remarkable ability to evolve due to processes such as highly high meiotic levels, mutation, and recombination rates. As a result of the improved evolvability, unique characteristics have made it an ideal eukaryote model and a biotechnological model.

Dr. Michnick gave instances of how variations in the mechanical characteristics of chromatin reflect locally and globally genome adaptations, indicating phase separation induced by histone post-translational modifications and resulting changes in histone exchange rates.

Rosana Collepardo Guevara (University of Cambridge, UK)
The separation of chromatin and its associated proteins in the liquid-liquid phase separation is gaining traction as a method for explaining the organization of the Eukaryotic nucleus. In this talk, Dr. Collepardo Guevara elaborated on how we can resolve individual nucleosomes within sub-Mb chromatin domains and phase-separated systems using multiscale chromatin approaches that integrate atomistic representations of DNA and proteins. The models presented by her enable us to link molecular and biophysical characteristics of individual nucleosomes to chromatin phase separation regulation. She explained how the variables that keep nucleosomes organized in a disorderly, liquid-like fashion within single chromatin arrays also favour phase separation of a solution of chromatin arrays.

Sara Cuylen-Häring (EMBL Heidelberg, Germany)
The inherently disordered protein Ki-67 covers the surface of the mitotic chromosome, the most enormous membrane-less cellular structure. Previous research has shown that Ki-67 has two functions. Ki-67 acts as a surfactant in early mitosis, preventing chromosomes from collapsing into a single chromatin mass, yet it actively promotes chromosomal clustering towards the mitotic exit. It’s still a mystery how Ki-67 flips between these two opposing activities — chromosomal dispersal and chromosome clustering.

Dr. Cuylen-Häring showed that when all chromosomes combine into a single cluster during anaphase beginning, Ki-67’s biophysical properties alter dramatically. The amphiphilic nature of Ki-67 is lost as the molecular brush structure collapses and the protein’s soluble pool condenses. Her research reveals a cell-cycle-dependent mechanism that regulates the individualization and coalescence of cells.

David Zwicker (Max Planck Institute for Dynamics and Self-Organization, Germany)
He elaborated on how biological cells are made up of thousands of different macromolecules that organize themselves into condensates and other structures. How can numerous distinct condensates reliably develop despite massive composition changes? He presented a novel numerical approach for determining coexisting phases in multicomponent systems. This method helps to maximize component interactions, similar to how evolution may have optimized biomolecule interactions. Random or contrived interactions perform worse than evolved interactions in producing a defined number of phases. The improved interactions also resist perturbations and allow for quick adaptation to new phase counts. He detailed how genetically programmed biomolecule interactions can govern the production of condensates in various ways.

Mrityunjoy Kar (MPI-Cell Biology and Genetics, Germany)
The creation and breakdown of membrane-less biomolecular condensates such as RNA-protein granules are linked to phase separation of RNA binding proteins with disordered prion-like domains and RNA binding domains. DLS, nanoparticle tracking analysis, fluorescence anisotropy, microfluidic confocal spectroscopy, and TEM investigations of cluster size distributions in sub-saturated solutions of phase-separating RNA binding proteins from the FUS-EWSR1-TAF15 (FET) family were presented by him. He elaborated how in saturated solutions, these systems exhibit heterogeneous cluster distributions. While the most prevalent species are small clusters, cluster size distributions appear to be heavily tailed. Furthermore, when bulk concentrations rise, cluster size distributions continue to trend toward bigger values. DLS tests also reveal that these clusters are reversible when diluted and concentrated, and FRET measurements show that protein molecules interchange between clusters and the bulk solution. At and beyond the saturation concentration (csat) of phase separation, these clusters coarsen and produce condensates. These observations are readily explained in terms of associative polymer theories.

Martin Wühr (Princeton University, USA)
He briefed about membrane-bound organelles like mitochondria and membrane-less biomolecular condensates (BMCs) like the nucleolus achieve compartmentalization, which is a fundamental aspect of eukaryotic life. BMCs that have been identified have liquid-like characteristics and are often viewed on a 1 µm scale. He further explained that they’ve largely been investigated using microscopy to look at certain proteins. Several dozen BMCs have been identified so far, each with a different function, such as transcription regulation, RNA management, or signaling, and their dysfunction can result in illnesses. However, it is unknown how BMCs are used in the cellular organization or at what length scale they form. At the scale of 100 nm, he showed his data that at least 18% of the proteome is structured into mesoscale BMCs. They have used differential pressure filtration, size exclusion, and dilution procedures to explore the structure of native cytoplasm on a global scale utilizing quantitative proteomics. By examining protein penetration through porous substrates with known pore diameters, they were able to confirm mesoscale sizes using imaging below the diffraction limit. The results he presented revealed that at unexpectedly short length scales, eukaryotic cytoplasm organizes itself extensively via liquid-like assemblies.

Danfeng Cai (Johns Hopkins Bloomberg School of Public Health, USA)
In 22.5 percent of papillary renal cell carcinomas (PRCCs), the Hippo pathway is dysregulated, resulting in hyperactivated YAP1/TEAD1 activity. However, it is unclear how YAP/TEAD1 contributes to PRCC development. His research group found that transcription factor TEAD1 generates liquid-like nuclear condensates inside PRCC patient-derived cell lines using super-resolution imaging and PRCC patient-derived cell lines. TEAD1 condensates appear in a variety of sizes and functions, which is intriguing.

Smaller, sub-micron-scale TEAD1 condensates facilitate active transcription, whereas larger, micron-scale TEAD1 condensates repress transcription: they lack YAP1, are devoid of active transcription markers BRD4 and H3K27Ac, and are found in different heterochromatic nucleus compartments.

Keynote lecture: A fluid paradigm for biological organization, Clifford Brangwynne (Princeton University, United States of America)
Living cells are frequently misunderstood as machines on a factory floor, operating through a clockwork-like series of interactions among their biomolecular building pieces. However, internal cell activities are far more wet and active than many textbooks would have us assume. Research integrating concepts from materials physics and cell biology has ushered in a new paradigm for understanding how this chaotic intracellular environment is brought to order through the collective condensation of disordered proteins into droplets of living information throughout the last decade. Intracellular condensates are viscoelastic states of biomolecular matter that aid dozens of intracellular processes and appear to be at the root of malignancies and neurological disorders such as Alzheimer’s and ALS.

On-site and virtual meetings

After an almost four-year-long break, the on-site event resumed at the EMBL campus in Heidelberg. People enjoyed networking and interacting with others which boosted their morale. The pandemic has taught us to come up with new approaches to our actions, and virtual meetings are one of them. Many people across the globe benefitted from the conference being set up in a hybrid format and enjoyed the amount of knowledge that this event showered upon them.

This blog post is written by Ritvik Gupta, Master’s thesis student at Didier Stainier’s Group, Max Planck Institute for Heart and Lung Research, Germany, pursuing BS-MS at IISER Mohali.

Learn more on how to become an event reporter for EMBL Events


Competency-based training in bioinformatics

This article was written by Victoria Hill, Chemistry PhD student at the University of Sheffield.

Recently, EMBL-EBI, in collaboration with a number of our EU project partners, launched the Competency Hub. This is a free platform where students and professionals can evaluate their abilities against the competencies of that framework.

Competency Hub hero image
Competency Hub: Supporting competency-based training and professional development.

What is a competency?

A competency is an observable and measurable ability of any professional, specific to those required in your field. They’re further broken down into the Knowledge, Skills, and Attitudes (KSAs). 

The competencies are all mapped to career profiles ranging from PhD student to senior roles, both in industry and academia, and assigned a grade on a scale that measures the level the individual should be at in that competency depending on the profile. For a more in-depth analysis, the user can go into each graded competency and look at which KSAs are applicable at that career stage. 

An example of a competency within the BioExcel framework graded at ‘Awareness’ and the associated KSAs mapped to the career profile ‘PhD Student in Biomolecular Simulations’.
An example of a competency within the BioExcel framework graded at ‘Awareness’ and the associated KSAs mapped to the career profile ‘PhD Student in Biomolecular Simulations’.

What does the Competency Hub offer?

  • Evaluate your competencies against those of each framework by creating a  profile and comparing them to the pre-defined career profiles. 
  • Find training resources for each competency, and in some frameworks, more in-depth learning pathways for skills relevant to that field.
  • Develop courses as a trainer using the Competency Hub. Define your audience, plan your content, and write learning outcomes, as well as compare your resources to what is already available. 
  • Assess whether, as a trainer, you are targeting the correct audience and use the competencies to provide an overview to stakeholders.
  • Evaluate your team and create job descriptions as a manager.
Competency Hub Avatar
An example avatar

How did we do it?

After a pilot project with the BioExcel Knowledge Resource Centre, we decided to create a site where everybody can access all the information included in the competency framework. 

The Competency Hub was developed by the EMBL-EBI Training and Web Development teams in dedicated two-week collaborative development sprints. 

A goal was defined for each sprint; our most recent one focused on improving the career profile journeys. Previous sprints included making the site more user-friendly, adding learning pathway functionality, and adding career profiles, among other tasks to constantly improve the site.

What is next?

At the end of each sprint, we gain feedback from users to determine our next goals. The next sprint will focus on improving the connections between the competencies and the career profiles to the training resources.

Want to get involved with future development? Fill in our survey.

We’d love to hear what you think of this new feature! Tell us on Twitter using @EBItraining.

‘Building networks: engineering in vascular biology’ – check out the awarded posters!

There were 5 poster prizes awarded at the recent EMBO Workshop ‘Building networks: engineering in vascular biology’,  hosted by EMBL Barcelona at the Barcelona Biomedical Research Park (PRBB) and bringing together vascular biologists and bioengineering researchers from across Europe and beyond, who are pioneering new tools towards understanding vascular biology in health and disease. For many participants this was the first on-site meeting that they attended since early 2020 and the spirits were high during the three days full of exciting science, exchanging ideas, presenting latest research, catching up with old friends and making new ones.
We also didn’t have any complaints regarding outdoor coffee breaks on a sunlit deck overlooking the sea! There were two live poster sessions during which the presenters could discuss their research (over snacks and drinks!) – their work was then voted for by other attendees and speakers. We are pleased to be able to share with you the research from the five winners of the best poster prizes: congratulations to Claire, Akinola, Irene, Nensi and Anjali!

Contact guidance of vascular endothelial cells on microgrooved substrates: influence of groove dimensions and cell density

Presenter: Claire Leclech

Claire Leclech, LadHyX, CNRS, École Polytechnique, Institut Polytechnique de Paris, France

In healthy arteries, endothelial cells (ECs) exhibit different morphologies: elongated and aligned in the direction of blood flow or more cuboidal in regions of arterial branches and bifurcations. Factors that regulate EC morphology and alignment are of interest, particularly in light of the observation that atherosclerotic lesions preferentially form in regions where ECs are less aligned and elongated. In vivo, the basement membrane to which ECs adhere is a patterned and topographic surface. We are interested in how this substrate topography may regulate EC shape and alignment and are exploring these questions in vitro using microfabricated surfaces.
When cultured on substrates composed of parallel arrays of microgrooves, ECs align and elongate in the direction of the grooves, a process called contact guidance. We show that we can control the extent of this contact guidance by modulating the groove dimensions (spacing, width, and depth). In particular, we demonstrate that increasing groove depth (from 1 to 6 μm) leads to the most pronounced cell elongation and alignment. We also investigate the influence of cell density on the response to microgrooves by comparing the response of individual cells to monolayers of low or high density. Interestingly, we observe progressive loss of cell alignment and elongation on microgrooves for increasing cell density/culture time, associated with remodeling of the actin cytoskeleton and focal adhesions (FAs).
We are investigating the mechanisms underlying this depth- and density-dependent response of ECs to the microgrooves and propose that a competition between cell-substrate and cell-cell adhesion may explain the existence of different mechanisms. In individual cells, the depth-dependent response predominates, driven by FA clustering and protrusion dynamics, while in highly confluent monolayers, ECs respond primarily to the secreted basement membrane and lose the response to substrate topography.
Beyond highlighting fundamental mechanisms of shape modulation and contact guidance in ECs, the results of this study can also prove useful in the field of implantable endovascular devices where surface topographic functionalization may constitute a promising strategy for improving device efficacy.

View the poster

Engineering 3D vascularized cardiac microtissues on-chip

Presenter: Akinola Akinbote

Akinola Akinbote, EMBL Barcelona, Spain

Coronary microvessels are implicated in many cardiovascular diseases (CVDs) and their dysfunction is associated with adverse clinical outcomes. These outcomes vary by biological sex and are hypothesized to differ based on estrogen’s cardioprotective effects. However, endothelial-dependent contributions to CVDs and sex-based differences are still largely unexplored, in part due to inadequate models of the cardiac microvasculature. The advent of iPSC-derived Cardiomyocytes (CMs) has resulted in a growth in cardiac models. 3-dimensional cultures and co-cultures with non-myocyte populations, such as cardiac fibroblasts and endothelial cells (ECs), have also been shown to improve cardiomyocyte maturation in vitro (marked by improved calcium handling and metabolic maturation); yet the impact of beating cardiomyocytes on cardiac microvascular remodelling and barrier function is not well understood. By employing microfluidic models of microvessels and iPSC-derived cardiac spheroids we can explore these complex CM-non-myocyte interactions in a controlled and quantifiable manner. We are generating adult-derived cardiac microvessels integrated with cardiac organoids to reveal the contribution of 1) non-myocytes (cardiac fibroblasts and endothelium) to cardiomyocyte function and 2). the effect of beating cardiac organoids on local microvascular remodelling. This unique vascularized cardiac model will be useful for understanding complex vascular-myocyte interactions and may provide clues to the role of sex hormones in promoting both endothelial and cardiac function.

Due to the confidentiality of the unpublished data, we cannot share the poster.

Temporal adaptation of vascular patterning

Presenter: Irene M. Aspalter

Irene Aspalter, Cell Adaptation Laboratory, The Francis Crick Institute, UK

Sprouting angiogenesis is highly dependent on effective decision making between endothelial cells (ECs). The feedback between Vegf/Dll4/Notch is well established during the collective selection of tip cells of new vessel sprouts.
Our prior work demonstrates that additional signals (e.g. sema3E-plexinD1) can alter the tip cell selection speed by acting as time-keepers during Dll4/Notch signalling. Changes to the timing of this process alters the vascular network density.
It was believed that tip cells form filopodia post selection, aiding the migration towards Vegf. However, our recent in silico models, validated in vivo, show that ECs form filopodia first, irrespectively of whether they are selected as tip. Our simulations predict that filopodia speed up tip cell selection by moving Vegf-receptors towards the Vegf source, creating a sensory-motor-feedback that speeds up Dll4 production. Indeed, my preliminary in vitro data shows Vegf-receptors at the tip of filopodia. This suggests a vital role of filopodia as time-keepers during tip cell selection.
We aim to better understand the role of filopodia and other time-keepers to fine tune vascular patterning and network topologies.
Using microcontact printing I am developing a method to closely investigate the tip cell selection timing while modulating the involvement of filopodia and other pathways. Thin printed lines of extra cellular matrix allow ECs to interact, but not to swap positions, prohibiting disruption of Notch patterns in order to observe when stable patterns establish.
pERK has been previously shown as suitable tip cell marker in zebrafish and is also a useful marker in my system. Using pERK as readout, my preliminary data shows different selection patterns of tip/stalk cells in the presence or absence of Notch inhibitors, and we are currently developing an analysis pipeline for robust quantification.
This system will be used to carefully dissect the mechanism by which filopodia influence tip/stalk cell selection, with the help of molecular manipulation (growth factors/inhibitors) and micro manipulation (photo-activatable probes).
Our work will shed new light on the tip cell selection process and will offer new targets for therapeutic approaches targeting temporal regulation of vascular patterning, network topology and branching density.

View the poster

Resolving vascular endothelial junctions with correlative fluorescent light microscopy and cryo-electron tomography (cryo-ET)

Presenter: Nensi Alivodej

Nensi Alivodej, Max Planck Institute for Brain Research / Goethe University Frankfurt, Germany

Endothelial cells (ECs) form the inner lining of blood vessels, where they adhere to one another via junctional complexes, namely adherens and tight junctions, to regulate the integrity and permeability of the vascular barrier. These junctions are critical for tissue development and homeostasis and are structurally different across organs. For example, ECs of the brain possess strong tight junctions that are central to the formation of the blood-brain-barrier while ECs of the lung rely on adherens junctions to maintain vascular permeability at the interface of the blood-air barrier.
While the molecular composition of adherens and tight junctions is well studied, less is known about the assembly of junctional proteins in their native environment and their interaction with the cytoskeleton. Past cryo-electron tomography (cryo-ET) studies have been unsuccessful in resolving the structure of these junctions in situ owing to the difficulty in identifying them under cryo-electron microscopy. To circumvent this limitation, we have established a pipeline employing state-of-the-art correlative fluorescent light microscopy and cryo-ET in order to resolve junctions in ECs. We have isolated ECs from different organs, including the lung, brain and aorta, in mice expressing an EGFP-tagged VE-cadherin knock-in protein and have successfully grown them on electron microscopy (EM) grids. After cryo-fixation via plunge-freezing, we identified areas of interest expressing the fluorescently-tagged VE-cadherin using light microscopy and correlated those areas to EM images for localizing junctions. The areas were then processed to obtain a series of transmission EM images at multiple angles in order to reconstruct the three-dimensional organization of the junctions. This pipeline has allowed us to obtain the very first EM images of in situ adherens junctions from wholly preserved lung ECs, where individual VE-cadherin proteins, auxiliary adapter proteins and underlying cytoskeleton can be visualized with a pixel size of 0.22 nm. We are optimizing our workflow to also resolve tight junctions of the blood-brain-barrier. Altogether, we have established a scalable pipeline to characterize and compare the tissue-specific structural organization of vascular junctions with unprecedented sub-nanometer resolution.

Due to the confidentiality of the unpublished data, we cannot share the poster.

Geometry of self-assembled DNA nanostructures influences in-vitro angiogenesis in HUVECs

Presenter: Anjali Rajwar

Anjali Rajwar, Indian Institute of Technology Gandhinagar, India

DNA nanotechnology involves fabricating small strands of DNA to design nano-objects in 1D, 2D and 3D with precise control of shape and size that have been utilized in many applications.
DNA nanostructures have been investigated for their ability to influence cellular behaviour and functions. Recently, new emergent functionalities of DNA nanodevices as a class of biomaterials with immense capacity to interface with biological systems and vast potential in disease diagnosis and therapeutics have emerged. DNA nanostructures, which are chemically robust and biocompatible in nature, have been surface modified and structurally fine-tuned to find emerging applications in stem cell therapy and tissue regeneration. DNA nanostructures can be used for therapeutic angiogenesis, which involves the formation of new blood vessels, and can be used to treat ischemic diseases such as stroke or heart failure. This study looks at how the structural topology of DNA nanostructures affects their ability to stimulate endothelial cell angiogenesis.
We examined the potential of four different DNA nanostructure geometries on the differentiation of human umbilical vein endothelial cells (HUVECs). While different DNA nanostructure geometries successfully induced angiogenesis and cell migration in HUVECs, tetrahedral DNA cages demonstrated the greatest uptake and angiogenesis potential, indicating that not only the composition of materials, but also the 3D arrangement of ligands may play a role in stimulating the angiogenesis process.
Taken together, this research can lay the groundwork for future studies involving DNA nanocages for biological and biomedical applications, explicitly applying their surface topologies in bioimaging, drug delivery, immune activation, and tissue engineering.

View the poster


Congratulations to all five winners!

The EMBO Workshop ‘Building networks: engineering in vascular biology’ took place from 9 – 11 May 2022 at EMBL Barcelona.