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Meyer zu Hoerste, G.

Publications and source records attributed to Meyer zu Hoerste, G..

5 recordsLinked to original sources

Spermatogonial stem cells and their differentiation roadmap throughout marmoset development

Sperm transfer genetic information from one generation to the next. These cells originate from gonocytes, which are specified during early embryonal development. To date however, there is limited information on the transcriptional gatekeepers governing the key events leading to sperm production: transition of gonocytes out of pluripotency around the time of birth, formation of the spermatogonial compartment prior to puberty, and initiation of germ cell differentiation at the time of puberty. We address this knowledge gap by employing the marmoset monkey (Callithrix jacchus) as a model for human postnatal testicular development. We analysed the transcriptional profiles of [~]48,000 neonatal, pre-pubertal, pubertal, and adult testicular cells and correlated these with histomorphometric measurements. We uncovered a transcriptional state linking gonocytes and spermatogonia characterized by CITED2 expression. Moreover, we propose NANOS2 and DPPA4 as regulators of spermatogonial plasticity from pre-puberty onwards and identify molecular gatekeepers of male germ cell differentiation.

developmental biology↗

The nuclear receptor NR4A1 serves as a neutrophil-intrinsic regulator mitigating stroke severity

Ischemic stroke is accompanied by recruitment and activation of immune cells which play an important role in the progression of the brain damage. The nuclear receptor NR4A1 emerged as a key regulator within the inflammatory response of several immune diseases by regulating immune cell activation. In this study, we investigated the role of NR4A1 in the activation and recruitment of brain resident and peripheral immune cells after cerebral ischemia. Here, we show that NR4A1 mediates an anti-inflammatory and damage-limiting effect after stroke. This effect is largely mediated by neutrophil recruitment and importantly, NR4A1 activation with its ligand Cytosporone B improves functional outcome and reduces brain damage. Modulation of NR4A1 is therefore a promising therapeutic target for the treatment of the nuclear receptor NR4A1 in the activation and recruitment of peripheral and brain resident immune cells after cerebral ischemia and its consequences for stroke outcome. We demonstrate that NR4A1 ablation augments neutrophil activation and CNS recruitment within days after stroke thereby increasing infarct size, CNS inflammation, neuronal damage and deteriorating functional outcome. This effect is mediated via modulation of cell-intrinsic neutrophil function and maturation as illustrated by neutrophil-specific NR4A1 ablation and mixed bone-marrow chimera experiments. Notably, the NR4A1 agonist Cytosporone B reduced CNS neutrophil infiltration, infarct size and functional outcome after stroke in a bicentric preclinical stroke trial, demonstrating that NR4A1-mediated control of neutrophil reactivity is amenable to pharmacological modulation. In humans, NR4A1 expressing neutrophils are present in the peripheral blood of stroke patients and neutrophil NR4A1 expression correlates with improved long-term outcome after 3 months. Furthermore, NR4A1 expression in brain parenchyma neutrophils is negatively correlated with neuronal cell loss, illustrating a role of NR4A1 in regulating neutrophil mediated neuronal cell death in human stroke. Together our data reveal the nuclear factor NR4A1 as a brake of intrinsic neutrophil activity controlling neutrophil-mediated brain inflammation and neurotoxicity in stroke which may serve as a novel therapeutic target to limit inflammation-associated augmentation of ischemic damage after stroke.

neuroscience↗

Multi-omic characterization of human sural nerves acrosspolyneuropathies

Diseases of peripheral nerves termed polyneuropathies (PNPs) are common, mechanistically heterogeneous, and challenging to diagnose. Here, we integrated single nuclei transcriptomics of peripheral nerves from 33 human PNP patients and four controls (365,708 nuclei) with subcellular spatial transcriptomics. We identified novel and human-specific nerve cell type markers including unexpectedly heterogeneous perineurial fibroblasts. All PNPs shared a loss of myelinating and an increase in repair Schwann cells and endoneurial lipid-associated macrophages. Transcriptional changes affected multiple cells outside of the endoneurium across PNPs, suggesting PNPs as pan-nerve diseases. Spatially, PNPs showed a previously unknown perineurial hyperplasia and fibrotic dispersion and this was most pronounced in immune-mediated PNPs. Single cell transcriptomics supported the differential diagnosis of PNPs with potential for future unbiased diagnostic classification. One-sentence summaryThe first large-scale integrated single cell and spatial transcriptomic characterization of human peripheral nerves identifies novel cell markers and unexpected heterogeneity of perineurial cells, reveals polyneuropathies as pan-nerve diseases, and shows that single cell transcriptomics hold potential for unbiased nerve disease classification.

neuroscience↗

CSF plasma cell expansion in LGI1-/CASPR2-autoimmune encephalitis is associated with loss of regulatory MAIT cells

Anti-Leucine-rich glioma inactivated-1 (LGI1) and anti-contactin-associated-protein-2 (CASPR2) associated autoimmune encephalitis (AIE) variants are characterized by directly pathogenic autoantibodies present in serum and CSF. The dynamics and drivers of intrathecal and systemic autoantibody production are incompletely understood. We aimed to elucidate the immunologic basis of the LGI1-/CASPR2-associated AIE variants by performing multi-omic profiling of CSF/blood in untreated patients. We validated findings by flow cytometry in independent cohorts and confirmed functionality using rodent immunization. We identified clonal IgG2 and IgG4 plasma cell expansion and affinity maturation in the CSF together with clonally restricted, activated, antigen-experienced CD8 and CD4 T cells as a hallmark of these encephalitis variants. Using recombinant cloning, we confirmed that expanded CSF plasma cell clones almost exclusively bound the respective neuronal autoantigen. In addition, we found a loss of regulatory mucosa-associated invariant T (MAIT) cells and gamma delta T cells in the CSF and - to a lesser degree - in blood. We validated the functional role of these invariant T cells using a novel murine active immunization paradigm using both autoantigens: MAIT cells suppressed systemic formation of LGI1 and CASPR2-specific anti-neuronal antibodies. We propose that loss of systemic and intrathecal regulatory mechanisms mediated by innate-like T cells promote plasma cell expansion and autoantibody production as a shared mechanism in AIE. One sentence summaryCerebrospinal fluid (CSF) and peripheral blood (PB) single cell transcriptomics of patients with untreated anti-LGI1 and anti-CASPR2 autoimmune encephalitis demonstrated CSF specific expansion of autoantigen-specific plasma cell clones and systemic loss of invariant mucosa-associated T-cells (MAIT).

neuroscience↗

EGR4-dependent decrease of UTF1 is associated with failure to reserve spermatogonial stem cells in infertile men

Despite the high incidence of male infertility, about 70% of infertile men do not receive a causative diagnosis. To gain insights into the regulatory mechanisms governing human germ cell function in normal and impaired spermatogenesis (cryptozoospermic patients, crypto), we combined single cell RNA sequencing (>30.000 cells), proteome, and histomorphometric analyses of testicular tissues. We found major alterations in the crypto spermatogonial compartment with increased numbers of the most undifferentiated spermatogonia (PIWIL4+ State 0 cells). We also observed a transcriptional switch within the spermatogonial compartment driven by the increased and prolonged expression of the transcription factor EGR4. Intriguingly, EGR4-regulated genes included the chromatin-associated transcriptional repressor UTF1, which was downregulated. Histomorphometrical analyses showed that these transcriptional changes were mirrored at the protein level and accompanied by a change in the chromatin structure of spermatogonia. This resulted in a reduction of Adark spermatogonia - characterized by tightly compacted chromatin and serving as reserve stem cells. These findings suggest that crypto patients are at a disadvantage especially in cases of gonadotoxic damage as they have less cells safeguarding the genetic integrity of the germline. We hypothesize that the more relaxed chromatin status of spermatogonia is dependent on decreased UTF1 expression caused by EGR4 activation. These identified regulators of the spermatogonial compartment will be highly interesting targets to uncover genetic causes of male infertility. One Sentence SummaryReserve spermatogonial stem cell depletion in infertile men is regulated by an EGR4-dependent UTF1 decrease, which changes chromatin morphology.

molecular biology↗