Tongue immune compartment analysis reveals spatial macrophage heterogeneity

The tongue is a unique muscular organ situated in the oral cavity where it is involved in taste sensation, mastication, and articulation. As a barrier organ, which is constantly exposed to environmental pathogens, the tongue is expected to host an immune cell network ensuring local immune defence. However, the composition and the transcriptional landscape of the tongue immune system are currently not completely defined. Here, we characterised the tissue-resident immune compartment of the murine tongue during development, health and disease, combining single-cell RNA-sequencing with in situ immunophenotyping. We identified distinct local immune cell populations and described two specific subsets of tongue-resident macrophages occupying discrete anatomical niches. Cx3cr1(+) macrophages were located specifically in the highly innervated lamina propria beneath the tongue epidermis and at times in close proximity to fungiform papillae. Folr2(+) macrophages were detected in deeper muscular tissue. In silico analysis indicated that the two macrophage subsets originate from a common proliferative precursor during early postnatal development and responded differently to systemic LPS in vivo. Our description of the under-investigated tongue immune system sets a starting point to facilitate research on tongue immune-physiology and pathology including cancer and taste disorders

Ten simple rules for implementing open and reproducible research practices after attending a training course

Open, reproducible, and replicable research practices are a fundamental part of science. Training is often organized on a grassroots level, offered by early career researchers, for early career researchers. Buffet style courses that cover many topics can inspire participants to try new things; however, they can also be overwhelming. Participants who want to implement new practices may not know where to start once they return to their research team. We describe ten simple rules to guide participants of relevant training courses in implementing robust research practices in their own projects, once they return to their research group. This includes (1) prioritizing and planning which practices to implement, which involves obtaining support and convincing others involved in the research project of the added value of implementing new practices; (2) managing problems that arise during implementation; and (3) making reproducible research and open science practices an integral part of a future research career. We also outline strategies that course organizers can use to prepare participants for implementation and support them during this process

The role of microglia dysfunction in Huntington’s Disease

Huntington’s disease (HD) is a chronic, autosomal-dominant neurodegenerative disease that is caused by a CAG trinucleotide repeat expansion in exon 1 of the huntingtin gene. Progressive striatal atrophy and cortical thinning are commonly observed in HD, resulting in movement, psychiatric and cognitive impairments. It is generally thought that the increase in CAG repeats in the huntingtin gene leads to a toxic gain of function that results in the accumulation of nuclear and cytoplasmic inclusions and progressive neurodegeneration. The exact mechanisms of how mutant huntingtin causes neurotoxicity, however, remain unclear. In the past years, both clinical and experimental evidence has emerged that points towards the involvement of the innate immune system in HD. In fact, an activated state of central nervous system (CNS) and peripheral myeloid cells precedes HD symptom onset in patients. Microglia - the resident parenchymal immune cells of the CNS - are phenotypically altered in both clinical and experimental settings of HD, but it is still not clear whether and how changes in microglia can contribute to HD pathogenesis. To address this open question, two mouse models of HD were employed in this study. Firstly, the R6/2 mouse, which expresses a pathogenic human mHTT fragment in all cells of the body, was used to assess any changes that microglia undergo on a transcriptional level as a response to mHTT ubiquitous expression. The same model was used to deplete microglia and measure whether this could rescue disease progression. To take a closer look at the cell-autonomous effects mHTT has on microglia, I generated a novel mouse model in which the mHTT pathogenic fragment is targeted specifically to microglia (MG-HD). A series of cytometric, transcriptomic, imaging and behavioural analyses revealed that mHTT-expressing microglia display an activated phenotype in vivo in both mouse models. However, any cell-autonomous effects of mHTT on microglia observed in MG-HD mice were mild and transient and not sufficient to drive an HD-like neuropathological phenotype. Furthermore, depletion of microglia in the R6/2 mouse did not rescue the HD-like symptoms. The results suggest that microglia are affected in HD but are not primarily responsible for neurodegeneration.Die Huntington-Krankheit (HK) is eine chronische, autosomal-dominante neurodegenerative Erkrankung, die durch eine CAG Trinukleotidrepeatexpansion in Exon 1 des Huntingtin Gens verursacht wird. Bei HK Patienten werden oft progressive striatale Atrophie sowie kortikale Ausdünnung beobachtet, die zu Bewegungs-, psychiatrischen und kognitiven Störungen führen. Es wird vermutet, dass die Erhöhung der CAG Repeats im Huntingtin Gen zu einem toxischen Funktionszugewinn führt, der in der Folge für die Ansammlung von nukleären und zuytoplasmatischen Einschlusskörpern und für progressive Neurodegeneration verantwortlich ist. Die genauen Mechanismen, mit denen das mutierte Huntingtin Gen Neurotoxizität verursacht, sind jedoch bisher weitestgehend unbekannt. Klinische und experimentelle Beweise der letzten Jahre deuten auf eine Beteiligung des angeborenen Immunsystems in der HK hin. Es konnte gezeigt werden, dass dem Auftreten der Symptome in Patienten ein aktivierter Zustand von Zentralnervensystem (ZNS) und peripheren Myeloidzellen vorangeht. Mikroglia – die hirneigenen parenchymalen Immunzellen des ZNS – sind sowohl in klinischen, als auch in experimentellen Formen der HK phänotypisch verändert. Noch ist jedoch unklar, ob und in wiefern Veränderungen der Mikroglia zur Pathogenese der HK beitragen. Um diese Frage zu beantworten wurden in der vorliegenden Studie 2 Mausmodelle der HK eingesetzt. Zuerst wurde die R6/2 Maus, die in allen Körperzellen ein pathogenes menschliches mHTT-Fragment exprimiert, verwendet, um jegliche Veränderungen der Mikroglia auf transkriptionaler Ebene festzustellen, die als Folge der ubiquitären mHTT Expression auftreten. Das gleiche Modell wurde benutzt, um Mikroglia zu entziehen und um zu messen, ob der Entzug das Fortschreiten der Krankheit verhindern kann. Um die zellautonomen Effekte von mHTT auf Mikrolglia genauer zu untersuchen, habe ich ein neuartiges Mausmodell generiert, in dem das pathogene mHTT-Fragment spezifisch auf Mikroglia abgezielt ist (MG-HD). Eine Reihe von zytometrischen, transkriptomischen, bildgebenden und Verhaltensanalysen haben gezeigt, dass Mikroglia, die mHTT exprimieren, in beiden Mausmodellen einen aktivierten Phänotyp in vivo aufweisen. Jegliche zellautonome Effekte von mHTT auf Mikroglia, die in MG-HD Mäusen beobachtet wurden, waren jedoch mild und flüchtig, und nicht ausreichend, um einen HK-ähnlichen neuropathologischen Phänotyp hervorzurufen. Außerdem konnte der Entzug von Mikroglia in der R6/2 Maus die HK-ähnlichen Symptome nicht abschwächen. Diese Ergebnisse deuten darauf hin, dass Mikroglia in der HK zwar beeinträchtigt sind, dass sie aber nicht primär für die Neurodegeneration verantwortlich sind

2018 - Improving [Your] Science Course - Charité Universitätsmedizin Berlin

Resources for the course (aimed at graduate students

2019 - Improving [Your] Science Course - Charité Universitätsmedizin Berlin

Resources for the course (aimed at graduate students

Ten simple rules for implementing open and reproducible research practices after attending a training course

Training in robust research practices is becoming increasingly common. However, many course participants may encounter challenges in implementation of what they learned after returning to their research groups. In this piece, we summarize insights and "lessons learned" from a group of former course participants. We offer practical tips on implementation and cultural change that may be useful for researchers at any career stage. In addition, we provide a list of considerations for course instructors to help them support course attendees after training is over