Damaged mitochondria recruit the effector NEMO to activate NF-κB signaling.

Failure to clear damaged mitochondria via mitophagy disrupts physiological function and may initiate damage signaling via inflammatory cascades, although how these pathways intersect remains unclear. We discovered that nuclear factor kappa B (NF-κB) essential regulator NF-κB effector molecule (NEMO) is recruited to damaged mitochondria in a Parkin-dependent manner in a time course similar to recruitment of the structurally related mitophagy adaptor, optineurin (OPTN). Upon recruitment, NEMO partitions into phase-separated condensates distinct from OPTN but colocalizing with p62/SQSTM1. NEMO recruitment, in turn, recruits the active catalytic inhibitor of kappa B kinase (IKK) component phospho-IKKß, initiating NF-κB signaling and the upregulation of inflammatory cytokines. Consistent with a potential neuroinflammatory role, NEMO is recruited to mitochondria in primary astrocytes upon oxidative stress. These findings suggest that damaged, ubiquitinated mitochondria serve as an intracellular platform to initiate innate immune signaling, promoting the formation of activated IKK complexes sufficient to activate NF-κB signaling. We propose that mitophagy and NF-κB signaling are initiated as parallel pathways in response to mitochondrial stress.

Correction: A modified TurboID approach identifies tissue-specific centriolar components in C. elegans.

[This corrects the article DOI: 10.1371/journal.pgen.1010150.].

A modified TurboID approach identifies tissue-specific centriolar components in C. elegans.

Proximity-dependent labeling approaches such as BioID have been a great boon to studies of protein-protein interactions in the context of cytoskeletal structures such as centrosomes which are poorly amenable to traditional biochemical approaches like immunoprecipitation and tandem affinity purification. Yet, these methods have so far not been applied extensively to invertebrate experimental models such as C. elegans given the long labeling times required for the original promiscuous biotin ligase variant BirA*. Here, we show that the recently developed variant TurboID successfully probes the interactomes of both stably associated (SPD-5) and dynamically localized (PLK-1) centrosomal components. We further develop an indirect proximity labeling method employing a GFP nanobody-TurboID fusion, which allows the identification of protein interactors in a tissue-specific manner in the context of the whole animal. Critically, this approach utilizes available endogenous GFP fusions, avoiding the need to generate multiple additional strains for each target protein and the potential complications associated with overexpressing the protein from transgenes. Using this method, we identify homologs of two highly conserved centriolar components, Cep97 and BLD10/Cep135, which are present in various somatic tissues of the worm. Surprisingly, neither protein is expressed in early embryos, likely explaining why these proteins have escaped attention until now. Our work expands the experimental repertoire for C. elegans and opens the door for further studies of tissue-specific variation in centrosome architecture.

[COVID-19 protective measures in nursing homes: Between autonomy and care - Results of an interview study]. / Covid-19 Schutzmaßnahmen in Alten- und Pflegeheimen: zwischen Autonomie und Fürsorge ­ Ergebnisse einer Interviewstudie.

Definition of the problem: This interview study investigated ethical issues in long-term care facilities from the perspective of caregivers during the coronavirus disease (COVID-19) pandemic. Due to the explorative as well as descriptive methodological approach, interview data are available and can be assigned to four central topics, which reveal a complex and sometimes conflictual reality of work and life in long-term care during the pandemic. On the one hand, the protective measures taken by the state and the institutions, as well as the resulting restrictions on the personal freedom of the residents are critically reflected and the degree of self-determination of the residents of nursing homes in the pandemic is questioned. On the other hand - given the pandemic-related measures - nursing activities in long-term care facilities as a place of work and life are described as challenging, especially regarding the changed nursing processes and quality of care, as well as due to the changed quality of relationships with the residents. Arguments: These four topics can basically be assigned to the ethical principles of autonomy and care and present a relevant concretization of the principle-oriented ethical challenges in long-term care during the COVID-19 pandemic. In the synopsis and interpretation of the results, it becomes apparent that the interviewed caregivers closely link the observance and implementation of the autonomy principle in everyday nursing care with the principle of care and the resulting well-being of the residents. Conclusions: Our results clearly show that the paradigm shift in long-term care, which has been developed over the last few decades, was (temporarily massively) weakened by the COVID-19 pandemic. In addition, the reported moral uncertainties and conflicts make it clear that caregivers need support regarding the ethical reflection of their nursing actions and that a sustainable integration of ethics counselling in long-term care facilities may be a possible approach to a solution.

The Role of ATG9 Vesicles in Autophagosome Biogenesis.

Autophagy mediates the degradation and recycling of cellular material in the lysosomal system. Dysfunctional autophagy is associated with a plethora of diseases including uncontrolled infections, cancer and neurodegeneration. In macroautophagy (hereafter autophagy) this material is encapsulated in double membrane vesicles, the autophagosomes, which form upon induction of autophagy. The precursors to autophagosomes, referred to as phagophores, first appear as small flattened membrane cisternae, which gradually enclose the cargo material as they grow. The assembly of phagophores during autophagy initiation has been a major subject of investigation over the past decades. A special focus has been ATG9, the only conserved transmembrane protein among the core machinery. The majority of ATG9 localizes to small Golgi-derived vesicles. Here we review the recent advances and breakthroughs regarding our understanding of how ATG9 and the vesicles it resides in serve to assemble the autophagy machinery and to establish membrane contact sites for autophagosome biogenesis. We also highlight open questions in the field that need to be addressed in the years to come.

An acentriolar centrosome at the C. elegans ciliary base.

In animal cells, the functions of the microtubule cytoskeleton are coordinated by centriole-based centrosomes via γ-tubulin complexes embedded in the pericentriolar material or PCM.1 PCM assembly has been best studied in the context of mitosis, where centriolar SPD-2 recruits PLK-1, which in turn phosphorylates key scaffolding components like SPD-5 and CNN to promote expansion of the PCM polymer.2-4 To what extent these mechanisms apply to centrosomes in interphase or in differentiated cells remains unclear.5 Here, we examine a novel type of centrosome found at the ciliary base of C. elegans sensory neurons, which we show plays important roles in neuronal morphogenesis, cellular trafficking, and ciliogenesis. These centrosomes display similar dynamic behavior to canonical, mitotic centrosomes, with a stable PCM scaffold and dynamically localized client proteins. Unusually, however, they are not organized by centrioles, which degenerate early in terminal differentiation.6 Yet, PCM not only persists but continues to grow with key scaffolding proteins including SPD-5 expressed under control of the RFX transcription factor DAF-19. This assembly occurs in the absence of the mitotic regulators SPD-2, AIR-1 and PLK-1, but requires tethering by PCMD-1, a protein which also plays a role in the initial, interphase recruitment of PCM in early embryos.7 These results argue for distinct mechanisms for mitotic and non-mitotic PCM assembly, with only the former requiring PLK-1 phosphorylation to drive rapid expansion of the scaffold polymer.

The Transmembrane Protein Semi1 Positions Gamete Nuclei for Reciprocal Fertilization in Tetrahymena.

During sexual reproduction in the ciliate, Tetrahymena thermophila, cells of complementary mating type pair ("conjugate") undergo simultaneous meiosis and fertilize each other. In both mating partners only one of the four meiotic products is "selected" to escape autophagy, and this nucleus divides mitotically to produce two pronuclei. The migrating pronucleus of one cell translocates to the mating partner and fuses with its stationary pronucleus and vice versa. Selection of the designated gametic nucleus was thought to depend on its position within the cell because it always attaches to the junction with the partner cell. Here we show that a transmembrane protein, Semi1, is crucial for attachment. Loss of Semi1 causes failure to attach and consequent infertility. However, a nucleus is selected and gives rise to pronuclei regardless of Semi1 expression, indicating that attachment of a nucleus to the junction is not a precondition for selection but follows the selection process.

The Inter-Rater Reliability of the Observation Instrument for Assessing Pain in Elderly With Dementia: An Investigation in the Long-Term Care Setting.

BACKGROUND AND PURPOSE: The Observation Instrument for Assessing Pain in Elderly With Dementia (BISAD) was developed in Germany. The instrument demonstrated high inter-rater reliability values for the original French version. So far, there are no results to that effect in the Austrian long-term care setting available. The objective of this study was to investigate agreement and inter-rater reliability of BISAD in residents with dementia. METHODS: A quantitative multicenter-descriptive cross-sectional design with a convenience sample of 71 residents. RESULTS: Analysis of all eight items demonstrated fair to moderate concordance. Absolute agreement of the total value was 25.32%. Subtotals of the observation before mobilization was 52.11%, and during mobilization 32.39%. CONCLUSION: The reliability analysis shows that the items are less reliable. Currently, BISAD does not make a reliable contribution to clinical decision making in the tested setting.