Jochen Feldmann

Afiliación:

LMU Munich, German

Título:

Semiconductor Nanocrystals:From Energy Conversion to Polaron Formation

Abstract:

Materials science has seen a substantial upswing due to much-needed solutions for sustainable energy conversion and storage. In particular, semiconductors offer a range of possibilities regarding solar cells, light emitting devices as well as catalytic and photoelectrochemical systems.

We have investigated nanocrystals made out of novel semiconductor materials. They are shaped and functionalized in such a way that we can tailor their properties for microscopic processes relevant for the above mentioned applications. In particular, time-resolved optical spectroscopy allows us to follow relaxation, recombination and reaction pathways of photocreated charge carriers in such nanostructures. Well-chosen chemical and geometrical structures can lead to tailored carrier relaxation and recombination pathways and thus to efficient energy conversion processes. Equally important, our investigations shed light on coupling effects between electronic excitations and the lattice. In particular, coherent phonons and polaronic effects are observed.

Xosé Bustelo

Afiliación:

CIC Salamanca

Título:

Deciphering the role of new oncogenic drivers in peripheral T cell lymphoma

Abstract:

The genomic characterization of multiple cancer types over the past decade has led to the identification of hundreds of genetic alterations potentially involved in cancer origin and progression. However, aside from the well-known oncogenes and tumor suppressor genes, the information gleaned from these sequencing efforts has often posed new scientific challenges and questions. These include understanding the actual role of low-frequency hotspot mutations in tumorigenesis; the extent of functional and clinical overlap among different mutant alleles of the same gene; and the function of unexpected antagonistic gain- and loss-of-function mutations found in certain genes and tumors. To illustrate these issues, we present data on various mutations identified in two genes, VAV1 and RHOA, in a clinical subtype of peripheral T-cell lymphoma originating from follicular helper T cells. To this end, we have employed a multifaceted strategy that utilized different mouse models and omics-, signaling-, biochemical-, and cell biology-related techniques. Our results clearly demonstrate that different mutations targeting the same gene can result in diverse downstream signaling effects, leading to distinct clinical features in the resulting cancer cells. Additionally, we present data suggesting that the paradoxical presence of gain- and loss-of-function mutations in RHOA found in different peripheral T-cell lymphoma patients can be explained by the acquisition of similar neomorphic functions by these seemingly antagonistic RHOA mutants. These findings underscore the long road that we have still to walk to fully understand the mutational landscape found in human tumors.

María Guix

Afiliation:

Chem in flow Group, Universidad de Barcelona

Title:

Designing Nano/Micromotors: Transitioning from Synthetic to Biohybrid Configurations

Abstract:

The basic key parameters to design synthetic nano and microrobots have been explored for the last two decades, demonstrating extensive applications in the biomedical and the environmental field. However, when living entities are integrated in such a robotics platform, the design and fabrication principles are completely different. The interest in developing biohybrid systems is due to the unique properties coming from its biological elements, such as self-healing, adaptability, or bio-sensing capabilities, which are specially challenging to obtain in their artificial counterparts. Several bio-hybrid robotics platforms across different scales had been developed, although the muscle-based robots have attracted increasing attention.

Regarding fabrication methods, 3D printing technologies have been particularly appealing for the fabrication of advanced living robots based on skeletal muscle cells, exploring new designs that are not bio-mimetic but especially efficient when it comes to mechanical self-stimulation. Additionally, the integration of nanomaterials in the cell-laden scaffold resulted in an enhanced force output. Indeed, the overall robot design and materials implemented are key to achieve the desired functionality in the resulting bio-hybrid robotic platform. Alternative 3D printing techniques to generate living robots either at bigger or smaller scales to the small scales will be presented. Another important challenge in the development of such living robots is the integration of control systems, which could be either aimed toward guidance purposes or to gather real time information over the robot performance (i.e., exerted force). Overall, the key feature when designing these new generations of robots using living components as an active material will be discussed, as well as the main challenges and applications, both in the biomedical and the environmental field.

Encarnita Mariotti-Ferrandiz

Afiliation:

Sorbonne Université, France

Title:

Blood T cell receptor repertoire studies: towards biomarker discovery in autoimmune and inflammatory diseases

Abstract:

Autoimmune diseases (ADs) are chronic and debilitating diseases representing an important societal burden. They call for disease-specific and curative treatments as well as for better diagnostic and prognostic markers. ADs result from patient’s T and B lymphocyte attacking their own tissues. While autoantibodies are used for AD diagnosis, T-cell are not considered for diagnosis in spite of their critical role in AD onset and maintenance. To tackle this major gap, we analyzed the T-Cell Receptor (TCR) repertoire by next-generation sequencing in various AD contexts. We sorted CD4 T effector cells (Teff) and CD4 T regulatory T-cells (Treg) from the blood and analyzed their TCRs using an innovative machine learning approach based on sparse least square discriminant analysis. When applied to type 1 diabetes (T1D) and rheumatoid arthritis (RA) patients, we identified Teff and Treg TCR signatures that i) classify these patients versus healthy volunteers with > 90% accuracy and ii) properly cluster T1D and RA patients separately. These signatures were shown to contain TCRs that were previously shown to relate to these conditions and were validated on external datasets. We also applied our analyses to sequential samples from lupus patients treated with low-dose IL-2. We identified a Treg TCR signature that could predict clinical response to treatment. Altogether, these results show that peripheral blood TCR repertoires contain relevant disease-specific information that could serve as biomarker to improve AD diagnosis, prognosis and patient care.

Antonio Reboreda

Afiliation:

Leibniz Institute for Neurobiology, Magdeburg, German

Title:

Single cell persistent firing is necessary for place cell integrity and working memory

Abstract:

Working memory is an ability necessary for everyday life. It allows us to hold information “online” to solve immediate tasks, like remembering a phone number we just heard. Increased neuronal firing has been shown in different neuronal areas (i.e.: prefrontal cortex, entorhinal cortex, hippocampus) while the subject is engaged in a task that requires working memory [1]. “Ex vivo” experiments show that neurons from those same areas show persistent firing in the presence of metabotropic agonists [2]. Nevertheless, the single cell nature of the persistent firing and the contribution of this activity to working memory is not really understood [3]. Moreover, working memory is one the key features affected by Alzheimer disease and increasing our understanding of the mechanisms involved in its regulation might open new therapeutic options.

In the present work we manipulate the ability of hippocampal neurons to support single cell persistent firing and we observe the effect on a working memory task. First, to manipulate the ability of single cells to support persistent firing, we used TRPC4 channel KD (TRPC4 KD). “Ex vivo” experiments confirmed that this manipulation reduces single cell's ability to support persistent firing. Second, to test the effect “in vivo”, animals performed a spatial working memory task where they needed to remember the left or right turn that they made over the delay period of 30 seconds to perform the task. Using this experimental paradigm, we recorded cells in the dorsal hippocampus that increased firing during the delay. In TRPC4 KD animals this increase in firing is strongly reduced and the task performance decreases. Overall, we demonstrate that the ability of hippocampal cells to support persistent firing is necessary for the formation of place cells and correct spatial working memory and that TRPC4 channels are required to generate persistent firing in CA1 neurons.

The project was funded by the federal state Saxony-Anhalt and the European Structural and Investment Funds (ESF, 2014–2020, project number ZS/2016/08/80645), the Deutsche Forschungsgemeinschaft projects YO177/4-1 and YO177/4-3 (to M.Y.) and German Center for Neurodegenerative Diseases (to A.D.)

References: [1] Constantinidis C, Funahashi S, Lee D, Murray JD, Qi XL, Wang M, Arnsten AFT., J Neurosci., 38(32), 7020-7028, (2018). [2] Arboit A, Reboreda A, Yoshida M., Cells, 9(2):365, (2020). [3] Kamiński J, Rutishauser U, Ann N Y Acad Sci., 1464(1), 64-75, (2020).

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Emiliano Cortés

Afiliation:

LMU Munich, German

Title:

Nanomaterials for Sustainable Energy

Abstract:

Nanostructured surfaces and colloids with designed optical functionalities - such as plasmonic & photonic nano and metamaterials - allow efficient harvesting of light at the nanoscale. Exploiting light-driven matter excitations in these artificial materials opens up a new dimension in the conversion and management of energy at the nanoscale [1-4]. One example are plasmonic and photonic catalysts that can indeed confine solar energy into molecular regions [4-14]. In this talk, I will present our recent efforts in order to understand the intricate energy conversion processes occurring in these systems by studying them at the single-particle level. I will present a series of studies trying to correlate plasmonic photocatalytic activity with reactivity, temperature and electric field at the nanoscale. Our fundamental understanding of light-matter interaction in these systems can hopefully contribute to the rational design of future nanocatalysts; influencing diverse applications such as photocatalysis, temperature management and sustainable chemistry, among others [1-14].

References [1] E. Cortés, Nature 614, 230-232 (2023) [2] E. Cortés, et al. Nature Rev. Chem., 6, 259–274 (2022) [3] E. Cortés, et al. Chem. Rev. 122, 15082–76 (2022) [4] S. Ezendam, et al. ACS Energy Letters, 7, 778-815 (2022) [5] M. Herran, et al. Adv. Funct. Mat., 2203418 (2022) [6] J. Gargiulo, et al. Nature Communications 14, 3813 (2023) [7] L. Nan, et al. Nano Letters 23 (7), 2883–2889 (2023) [8] A. Stefancu, et al. ACS Nano 17 (3), 3119–3127 (2023) [9] L. Hüttenhofer, et al., Adv. Energy Mat., 46, 2102877 (2021) [10] M. Herran, et al. Nature Catalysis, 6, 1205–1214 (2023) [11] S. Ezendam, et al. ACS Nano, 18 (1), 451-460 (2024) [12] S. Lee, et al. Angew. Chem. 136 (11), e202319920 (2024) [13] M. Liu, et al. JACS 146 (1), 468-475 (2024) [14] A. Stefancu, et al. Nature Physics, accepted (2024)

Jeff Mold

Afiliation:

Karolinska Institutet, Sweden

Title:

Determinism or Stochasticity in Cancer Evolution in Response to Stress

Abstract:

Cells perceive stress by activating canonical pathways aimed at repressing cell division, repairing damaged DNA, and removing harmful molecules. Mutations in genes involved in these pathways are among the most common in human cancers, with p53 (TP53) and p16 (CDKN2A) being typical examples. Inactivation of genes central to the stress response pathway enables cells to re-enter the cell cycle during periods where genomic integrity and cellular identity is compromised, possibly allowing for the generation of malignant cells. In this talk, I raise the hypothesis that the cellular response to stress (here in the form of drugs targeting different pathways for DNA replication) allows for the development of rare clonal populations which may represent the precursors of malignant cells. By combining clonal lineage tracing with high coverage full transcript RNA sequencing I aim to address whether diverse forms of cellular stress may lead to the activation of canonical pathways that give rise to genetic alterations and epigenetic modifications enabling the survival of such clones. This model is based on the controversial assumption that pathways exist which preference the survival of cells at the expenses of multicellular ecosystems. I hope to provide evidence for the possibility of such mechanisms and discuss experimental strategies we are currently employing to test these hypotheses.