Grants

Altered metabolism has a profound impact on differentiation and disease, but how do changes in a cell’s energy state induce specific phenotypes? We recently connected cell metabolism with embryonic stem cell (ESC) totipotency, the capacity to become all lineages the future organism, both embryonic and extra-embryonic. Based on preliminary data, we demonstrate that modified cell culture media can force metabolic change and induce totipotency via the NAD-dependent deacetylase, Sirt1. Here we ask how Sirt1 is regulated and how it acts to induce totipotency. As we can homogeneously induce this totipotent metabolic state, we have a unique opportunity to explore how metabolism regulates enhancer activity via an epigenetic enzyme. As metabolic reprogramming contributes to cancer development, understanding how metabolism regulates differentiation could lead to new treatments. In addition, metabolic reprogramming to totipotency is a new technology for regenerative and personalised medicine.

Recent research indicates that smooth muscle cells play a more pervasive role in atherosclerosis than previously anticipated. In mouse models, we and others have found that a few SMCs undergo massive clonal expansion and phenotypic modulation to produce major parts of plaques. Moreover, these modulated SMCs can be targeted to modulate the course of disease development. In human atherosclerosis, however, the types and quantities of modulated SMC subtypes have not yet been defined, and the role of clonal expansion is unknown. In the present proposal, we will exploit single-cell expression data from human plaque to define new markers for SMC subtypes, and we will map their presence in different plaque regions and lesion stages in our coronary plaque biobank. Furthermore, we will develop techniques to analyze clonal relationship in sections and determine whether SMC clonal expansion occurs in human atherosclerosis.

Novel personalized therapeutic strategies are urgently needed for non-small cell lung cancer (NSCLC). Thymidylate synthase (TS) is a nucleotide metabolism enzyme overexpressed in aggressive NSCLCs. TS inhibitors are available, but patients with high TS level are usually refractory and have shorter survival. We recently discovered a novel role for TS showing that, besides controlling proliferation, it determines the de-differentiated “EMT-like” state of cancer cells, orchestrating a wide range of gene expression changes. By using a gene reporter system we identified factors potentially modulating TS expression and several druggable genes in the TS regulatory network. We aim to characterize and target these pathways to enhance the efficacy of anti-TS drugs and to unmask therapeutically relevant vulnerabilities to drugs like metabolic inhibitors and immuno-therapeutic agents. This project may have important translational implications to reduce the devastating effects of aggressive NSCLCs.

T cell recognition of neoepitopes derived from cancer mutations critical for tumor destruction, and the ability to mount such neoepitope-directed T cell responses is essential for patient´s response to immunotherapy. Molecular mimicry, a phenomena where sequences from two unrelated proteins appear structurally similar upon presentation in MHC I can lead to T cell cross recognition between viral antigens and autoantigens, and this preexisting pool of memory T cell may influence our response to consecutive antigen challenge. The role of molecular mimicry between viral epitopes and neoepitopes, has however never been explored. We have the world’s largest dataset available, with >10.000 neoepitopes analyzed for T cell recognition. Adding together with publically available information of viral epitopes, we will make structure-guided analyses of molecular mimicry between neo- and viral epitopes and determine the impact of this phenomenon in mounting an efficient anti-cancer immune response.

Naturally occurring pulsations in the brain are physiologically very important and may be essential for clearance of brain waste products. The novel neuroimaging tool magnetic resonance encephalography (MREG) enables the investigation of these pulsations non-invasively in humans. We propose to exploit this novel tool to understand the outcome measures and apply it in a brain disorder. The first aim is thus to provide deeper mechanistic insight into MREG outcomes and investigate the extent to which MREG detected brain pulsations are linked to intracranial pressure in healthy controls. Subsequently, we aim to probe the diagnostic potential of MREG in a group of patients with idiopathic normal pressure hydrocephalus (iNPH), treatable with shunt. iNPH is a neurodegenerative disease which is underdiagnosed and undertreated because current diagnostics poorly predicts who will benefit from shunting. We will assess patients before and after treatment to evaluate the predictive value of MREG.

The function and survival of brain tissue depend on neurovascular coupling (NVC) mechanisms that adjust local cerebral blood flow (CBF) to meet local metabolic demands. This project addresses fundamental questions regarding NVC and inhibitory, GABAergic cortical activity: 1. Do interneurons release vasoconstrictors, reducing both net neuronal signaling and CBF, do they release vasodilators to support their metabolic demands, or both? 2. Do GABAergic neurons contribute to the microvascular dysfunction characteristic of Alzheimers’ disease (AD)? We will optogenetically manipulate non-classical cortical GABAergic (e.g., neurogliaform cell – NGFC) and monitor changes in microvascular diameters and CBF by two-photon microscopy in the cortex of awake mice. By elucidating NGFC NVC mechanism in normal and AD model mice, we hope to inform inferences about neuronal signaling from CBF changes observed in functional neuroimaging studies, and improve our understanding of inhibitory neurons in AD.

Extra or missing chromosomes (aneuploidy) in human eggs are the major cause of pregnancy loss, infertility and congenital disorders (e.g. Turner and Klinefelter syndrome). >20% of human egg are aneuploid and despite their importance, our knowledge of their origins is poor. Recently, we have established new technologies and egg collection programmes that allow us to start probing mechanisms that result in aneuploidy (Gruhn et al., Science, 2019; Zielinska et al.,Curr. Biol., in press; Ottolini et al., Nat Gen, 2015). In Objective 1, we explore maternal age-dependent and -independent changes to chromosome structure and function. In Objective 2, we initiate studies to test whether injection of human eggs with mRNA or proteins that might be rate limiting can improve chromosome segregation and reduce errors. Collectively, our proposal will yield novel insights into human eggs and may result in improved knowledge that could, eventually, lead to treatment for aneuploidy in human eggs.

In this proposal we focus on the Plakophilin-2 (PKP2) protein and its role in cardiac pathophysiology. Mutations in PKP2 are associated with a rare genetic human heart disease, arrhythmogenic right ventricular cardiomyopathy (ARVC). ARVC has devastating psychosocial consequences, as many patients are young adults, and the only therapy available consists of extreme exercise restriction and defibrillator implantation. The pathogenic mechanisms linking PKP2 to ARVC remain to be elucidated. Here we aim to identify exactly which parts of the cardiac protein landscape are affected in human ARVC hearts with PKP2 mutations. Furthermore, we aim to outline which intracellular signaling pathways are dysregulated upon exercise in a PKP2-dependent manner. Our approach is based on state-of-the-art mass spectrometry technologies and focuses on human heart biopsy material and on samples from a murine model of the disease.

The placenta is a remarkable temporary organ connecting mother and fetus during pregnancy. It supplies oxygen, nutrients and antibodies to the fetus, eliminates waste products, and produces hormones and cytokines. In this project, we will use three complementary approaches to study the molecular mechanisms of the placenta. In Study 1, we will characterize genetic regulation of expression levels of interleukin-1 genes in 400 placental samples collected after birth. In Study 2, we will perform the first genome-wide association study of placental weight, delineating maternal and fetal genetic influences on placental growth. In Study 3, we will characterize the dynamics of placenta-specific gene expression detectable in maternal blood through RNA-sequencing of 802 samples collected on a weekly basis from 31 pregnant women. The project will provide fundamental new knowledge about an otherwise inaccessible organ essential to healthy growth and development of the fetus and timely parturition.

Kainate receptors (KARs) are activated by the major excitatory neurotransmitter glutamate. KARs are localized at both pre- and postsynaptic neurons and thus, in addition to a direct excitatory effect, also play a role in modulating the activity of neuronal networks. KARs are involved in CNS diseases such as epilepsy, depression and schizophrenia, and therefore the understanding of the molecular function of these receptors is essential for unraveling their potential as target for treatment of these pathologies. We recently reported the first small molecule positive allosteric modulators (PAMs) that bind and potentiate KARs. This now opens an entire new research area with focus on optimizing potency, efficacy and selectivity of the PAMs as well as on the molecular determinants of PAM binding to KARs. The objective is to find the first high potency, high efficacy and preferably selective PAM acting on KARs and examine the role of KAR PAMs in hippocampal neurons.