Melanoma is the most aggressive type of skin cancer, and its spread to distal tissues is often a death sentence. Immunotherapies have led to increased survival rates but they are extremely expensive and efficient for approximately only 25% of patients. Therefore research into new methods to prevent or arrest the progression of melanoma is urgently needed. Nevi are pigmented lesions on skin which consist of a clonal mass of melanocytes in a state of proliferative arrest termed ‘senescent’. This state prevents further hyperplasia, but if mutations occur in proteins required to maintain senescence, cells can re-proliferate and progress into melanoma. Selectively clearing senescent melanocytes may therefore be an effective strategy to improve current preventative measures against melanoma. This project will use a combination of interdisciplinary techniques to identify and target molecular components that confer survival to senescent melanocytes. First, I will use whole-transcriptome analysis to identify novel genes associated to cell survival. Second, genes of interest will be validated via siRNA mediated gene silencing in vitro using techniques in molecular biology to assess viability and apoptosis. Third, selected targets will be validated in vivo using a unique novel mouse model established in the host laboratory where nevi can be induced and senescent cells can be quantified by luminescence. Successful identification of these targets may lead to future development of new therapies which help reduce the health and economic impacts of malignant melanoma.

Amyotrophic lateral sclerosis (ALS) is a fatal disease that progressively causes loss of neuronal and muscle function, for which there is no known cure. Although the genetic causes of ALS vary, the cytoplasmic accumulation of the TDP-43 protein in neurons is highly consistent among patients. Thus, TDP-43 is believed to be a point of convergence in the pathway responsible for ALS progression. However, while many genetic and cellular mechanisms have been linked to ALS, there is still a lack of understanding of the neuro-muscular interactions in ALS. In this project, we will identify neuronal or muscle cell-specific suppressors of motor impairment using an ALS model in the nematode worm Caenorhabditis elegans. In this model, transgenic C. elegans overexpress TDP-43 in the neurons, resulting in severe motility defects. We will use optogenetic tools to excite neurons and muscle cells separately in the C. elegans ALS model, contributing to our understanding of how TDP-43 accumulation affects tissue function. In addition, live in vivo microscopy of C. elegans will help us to elucidate the impact of TDP-43 on neuro-muscular interactions over time. Furthermore, novel automated tracking of the nematode worms enables high-throughput analysis of C. elegans mobility. Thus, we can efficiently analyse mobility when TDP-43 is overexpressed, and use this tracking for high-throughput screening of mutants that rescue the ALS phenotype. Once we have identified the mutants that Rescue Motility Defects (RescueMoDe), we will characterize their impact on neuronal and muscular function. Therefore, it will be possible to analyse the tissue-specific role of these candidates, and how they fit into the progression of TDP-43 toxicity in this system. Overall, we aim to further the understanding of ALS progression, which will allow a highly informed continuation of studies in mammalian cell culture or in murine model systems, which may lead to therapeutic research opportunities.

Schizophrenia (SCZ), bipolar disorder (BP), and Major Depressive Disorder (MD) are three major psychiatric disorders that affect mood, thinking, and behavior. These disorders are strongly genetically intercorrelated, and exhibit pronounced clinical overlap, suggesting that they are different manifestations of a shared underlying neurobiology, along a spectrum. However, the neurobiological mechanisms and pathophysiology of these disorders are still poorly understood, limiting effective drug discovery. There is an urgent need for new models for drug testing, as animal models have major limitations, and current psychiatric organoids systems are dependent on patient derived stem cells, in which technical, genetic and biological diversity confound the interpretation, and obscure the underlying neuropathology. The major challenge of this ERC proposal is to develop organoid models for psychiatric disorders by targeting upstream transcription factors. Transcription factors are key molecules that drive cell type differentiation including neuronal network formation. Hence, the central hypothesis of this ERC proposal is that neuronal subtype associated transcription factors can function as targets to model these disorders using brain organoids. However, the neuronal transcriptional regulators that mediate these disorders are currently unknown, and difficult to identify. Novel genomics technologies allow for an unbiased characterization of the brain in order to detect cell types and genes that are dysregulated in disease, and can be used to identify putative upstream transcription factors. Here, I propose a selection of multi-omics profiling - strategies to a unique collection of high quality psychiatric human brain tissue aimed at reliably identifying key upstream transcription factors. We will subsequently target those transcription factors in brain organoid systems to establish neurobiological models of these disorders.

Autophagy is one of the major intracellular degradation processes and it is essential for cell survival in multiple stress conditions. As a result, this pathway plays a key role in the pathophysiology of numerous illnesses including neurodegenerative, cardiovascular, chronic inflammatory, muscular and autoimmune diseases, and some malignancies. Structures targeted to destruction such as protein aggregates, organelles and invading pathogens are sequestered into double-membrane vesicles called autophagosomes. Autophagosomes are formed through the concerted action of the autophagy-related (Atg) proteins at a site specialized location known as the phagophore assembly site (PAS). Despite this knowledge, the mechanism and regulation of autophagy remain largely unknown. The host laboratory has found that Ymr1, a phosphatase dephosphorylating phosphatidylinositol-3-phosphate, plays a key role in the regulation of autophagy. The main objective of this project is to elucidate the mechanism through which Ymr1 regulates autophagy. To achieve this goal, the applicant will exploit the experimental advantages of the yeast model and use in combination cutting-edge techniques in molecular biology, biochemistry, fluorescence microscopy and electron microscopy. The results will advance our knowledge on autophagy and in a long-term perspective they will provide the conceptual bases for the development of therapies or compounds aimed to regulate autophagy to the benefit of human health. Through the realization of the project, the applicant will strongly reinforce his professional maturity, diversity and independence, essential for starting his own research activity.

Major Depression (MD) is often chronic and characterized by frequent recurrences of symptoms and burden. The need to better understand how and when relevant transitions in symptoms occur is urgent. A seemingly unsolvable scientific problem is the enormous etiological complexity of mental disorders such as MD, involving continuously ongoing gene-environment interactions that act in highly person-specific ways. This hampers accurate assessment of personalized risk. I will use an out-of-the-box and interdisciplinary approach to tackle this problem. MD is not the only phenomenon that is influenced by many factors, is unpredictable and makes sudden transitions. This is also the case for other so-called complex dynamical systems such as climate or water quality of lakes. For the latter systems generic early warning signals (EWS) have been found that indicate the approach of a transition. I hypothesize that transitions in mood can be anticipated using the same generic EWS as reported for other complex dynamical systems. Finding direct evidence for this hypothesis requires a completely novel approach in the field of psychiatry, which would involve (i) a design that captures data of the complete dynamic process within a single individual in order to detect the timing of EWS and sudden transitions in symptoms, prospectively and intra-individually, and (ii) frequent replications of these individual experiments. With help of recent technology and my acquired expertise I will use precisely this novel approach to search for personalized EWS that anticipate critical transitions in depression. This is the aim of my project. Evidence that transitions in mood behave according to principles of complex dynamical systems would change the field majorly. First, it would lead to a new understanding of mental disorders and the way we study them. Second, it would yield a sophisticated novel way of obtaining personalized and clinically relevant information on risk for transitions.