TRR 274: Checkpoints of Central Nervous System Recovery

Erythropoietin (EPO) is a cytokine that serves, independent of hematopoiesis, signalling functions within the brain, where EPO and its receptor are upregulated upon injury. The underlying mechanisms, however, have remained obscure. We aim to understand the roles of EPO/EPOR signalling as checkpoints of brain homeostasis and thereby specifically predict effects of recombinant EPO as a neuroprotective drug. To this end, we will explore the induction/expression of EPO and EPOR at the single cell ...

There is to date no therapy that prevents the devastating consequences of traumatic brain and spinal cord injuries. Previous work has shown that neuronal connections can spontaneously remodel after CNS injuries, a process that contributes to functional recovery. Here, we propose that the balance between adaptive and maladaptive neuronal remodeling depends on circuit refinement and is guided by the interplay between neuronal activity and microglia-driven synapse removal. We aim to identify the ...

This project focuses on recovery mechanisms of the CNS tissue in the course of acute T-cell mediated autoimmune inflammation. We hypothesize that T-cell induced changes of the grey matter are crucial for the failing recovery of the CNS after repeated autoimmune bouts and that lung microbiota are external regulators of de- and regenerative processes within the CNS tissue. We aim to identify brain-resident and peripheral targets to prevent permanent CNS damage and/or to foster its recovery which ...

The meninges are an important anatomical checkpoint for CNS autoinflammatory diseases, as this is where immune cells are recruited and where they can chronically persist. We propose that CNS persistent inflammation alters the meningeal milieu, particularly the vessels, creating a chronic inflammatory environment. This sustained inflammation impedes CNS recovery from acute damage. Our research aims to identify, in animal models and human samples of multiple sclerosis, cells and factors in the ...

Since the first funding period, Z02 has provided comprehensive support for all our research projects, from experimental design to bioinformatics data analysis. We specialize in bulk and single-cell genomic methods, including technologies like 10x Genomics and flow-cytometry based isolation methods. Additionally, we offer training on tissue preparation, single-cell sorting, and the use of 10x Genomics equipment to ensure high-quality data. By centralizing sample preparation, sequencing, and analysis, ...

The Z01 Bioimaging and Tissue Analysis Platform supports various CRC projects by analyzing human tissue samples and using state-of-the-art correlative light and electron microscopy techniques to study CNS recovery at a detailed level. During the first funding period, Z01 contributed to understanding key aspects of CNS recovery, such as axon damage, inflammation’s role in tissue healing, and how certain cells help repair nerve fibers. In the next funding phase, our focus will be on two main goals: ...

Strokes destroy excitatory inputs – not only in the stroke area, but also in remote regions such as the hippocampus, which may lead to disorganized GABAergic activity and cause cognitive decline. We propose here to identify and modulate checkpoints of GABAergic population dynamics shaping microcircuits of excitatory pyramidal neurons in the hippocampus. We aim at enhancing functional and structural rewiring processes by systematically modulating GABAergic interneuron activity and thus defining ...

Neuronal loss in acute or chronic brain disease could be treated by neuronal replacement strategies, such as transplantation of young neurons, if they integrate properly into the existing networks. Here we explore the cell-based and molecular mechanisms causing hyperinnervation and overshoot loss of input connectivity as well as the newly discovered hurdle in output connectivity, the lack of myelination. Candidate as well as unbiased approaches are pursued to identify the critical checkpoints and ...

The incidence of Alzheimer’s disease (AD), the leading cause of dementia, increases rapidly with age, but why age constitutes the main risk factor is still poorly understood. Brain ageing affects oligodendrocytes and the structural integrity of myelin sheaths1, the latter of which is associated with secondary neuroinflammation2,3. As oligodendrocytes support axonal energy metabolism and neuronal health4,5,6,7, we hypothesized that loss of myelin integrity could be an upstream risk factor for ...

Amyloid-β (Aβ) is thought to be neuronally derived in Alzheimer’s disease (AD). However, transcripts of amyloid precursor protein (APP) and amyloidogenic enzymes are equally abundant in oligodendrocytes (OLs). By cell-type-specific deletion of Bace1 in a humanized knock-in AD model, APPNLGF, we demonstrate that OLs and neurons contribute to Aβ plaque burden. For rapid plaque seeding, excitatory projection neurons must provide a threshold level of Aβ. Ultimately, our findings are relevant for AD ...

Concussions are a current health concern and account for the vast majority of head trauma. While symptoms after a single impact are usually transient, repetitive concussions, as often occur in sports, are responsible for persistent acute and chronic deficits. Here, we used a model of bilateral midline-centered concussions in mice to show that repetitive concussions selectively induce impairments in learning ability compared to single-impact injuries. Since microglial cells and their activation ...

T-cell receptor (TCR)-induced Ca2+ signals are essential for T-cell activation and function. In this context, mitochondria play an important role and take up Ca2+ to support elevated bioenergetic demands. However, the functional relevance of the mitochondrial-Ca2+-uniporter (MCU) complex in T-cells was not fully understood. Here, we demonstrate that TCR activation causes rapid mitochondrial Ca2+ (mCa2+) uptake in primary naive and effector human CD4+ T-cells. Compared to naive T-cells, effector ...

As tissue-resident macrophages of the central nervous system parenchyma, microglia perform diverse essential functions during homeostasis and perturbations1. They primarily interact with neurons by means of synaptic engulfment and through the rapid elimination of apoptotic cells and non-functional synapses2. Here, by combining unbiased lipidomics and high-resolution spatial lipid imaging, deep single-cell transcriptome analysis and novel cell-type-specific mutants, we identified a previously ...

Single-cell studies have revealed substantial microglial diversity in development, homeostasis and disease. However, a framework enabling comparison and stratification of microglial states across contexts is needed. Here we generated an atlas of myeloid cell states by single-cell RNA sequencing more than one million central nervous system cells from more than 30 physiological and pathological conditions. This atlas enables us to establish a comprehensive taxonomy of myeloid cell states across ...

Compartmentalized inflammation is a key driver of multiple sclerosis (MS) progression, but the mechanisms sustaining its persistence remain unclear. A hallmark of this persistent and slowly evolving inflammatory process is chronic active MS lesions. We generated a high-resolution, single-cell molecular and spatial atlas of such lesions by combining single-nucleus RNA sequencing (snRNA-seq) with multiplexed error-robust fluorescence in situ hybridization (MERFISH). Within lesion rims, we identified ...

After demyelinating injury of the central nervous system, resolution of the mounting acute inflammation is crucial for the initiation of a regenerative response. Here, we aim to identify fatty acids and lipid mediators that govern the balance of inflammatory reactions within demyelinating lesions. Using lipidomics, we identify bioactive lipids in the resolution phase of inflammation with markedly elevated levels of n-3 polyunsaturated fatty acids. Using fat-1 transgenic mice, which convert n-6 ...

Brain sections were collected from mouse model of amyloidosis and analyzed by MERFISH

To investigate TFEB-dependent expression in BCR-stimulated and resting B cells, CRISPR/Cas9 knockout cell lines were established and subjected to RNA sequencing analysis

Cortex and corpus callosum were dissected from every two animals (3-month-old) and pooled into one sample for single-nuclei RNA sequencing using 10x genomics Chromium 3’ assay. Each genotype has 2 replicates (in total n=4 animals).

Brain hemispheres were dissected from 6-month-old animals and subjected to single-nuclei RNA sequencing using 10x genomics Chromium 3’ assay. In total 4 genotypes were included for the experiment (WT, Cnp-/-, 5xFAD, Cnp-/-x5xFAD), each genotype has n=2 replicates.

Microglia cells from 6-month-old mouse brain hemispheres were isolated using the MACS sorting system and subjected to 50 bp single-end mRNA sequencing. Each genotype has n=4 replicates, in total 4 genotypes were included for experiment (WT, Cnp-/-, 5xFAD, Cnp-/-x5xFAD).

https://doi.org/10.6084/m9.figshare.28359797

CNS nuclei were isolated from frozen thalamic specimen, stained with anti-NeuN and anti-Olig2, FACS purified (DAPI+NeuN-Olig2-), and analyzed with snRNA-seq