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Alzheimer's, Parkinson's and Huntington's diseases can be caused by mutations that enhance protein aggregation, but we still do not know enough about the molecular players of these pathways to develop treatments for these devastating diseases. Here, we screen for mutations that might enhance aggregation in Caenorhabditis elegans, to investigate the mechanisms that protect against dysregulated homeostasis. We report that the stomatin homologue UNC-1 activates neurohormonal signalling from the sulfotransferase SSU-1 in ASJ sensory/endocrine neurons. A putative hormone, produced in ASJ, targets the nuclear receptor NHR-1, which acts cell autonomously in the muscles to modulate polyglutamine repeat (polyQ) aggregation. A second nuclear receptor, DAF-12, functions oppositely to NHR-1 to maintain protein homeostasis. Transcriptomics analyses of unc-1 mutants revealed changes in the expression of genes involved in fat metabolism, suggesting that fat metabolism changes, controlled by neurohormonal signalling, contribute to protein homeostasis. Furthermore, the enzymes involved in the identified signalling pathway are potential targets for treating neurodegenerative diseases caused by disrupted protein homeostasis., (© 2023 The Authors. Published under the terms of the CC BY 4.0 license.)

Myotonic Dystrophy type 1 (DM1) is a muscular dystrophy with a multi-systemic nature. It was one of the first diseases in which repeat associated non-ATG (RAN) translation was described in 2011, but has not been further explored since. In order to enhance our knowledge of RAN translation in DM1, we decided to study the presence of DM1 antisense (DM1-AS) transcripts (the origin of the polyglutamine (polyGln) RAN protein) using RT-PCR and FISH, and that of RAN translation via immunoblotting and immunofluorescence in distinct DM1 primary cell cultures, e.g., myoblasts, skin fibroblasts and lymphoblastoids, from ten patients. DM1-AS transcripts were found in all DM1 cells, with a lower expression in patients compared to controls. Antisense RNA foci were found in the nuclei and cytoplasm of a subset of DM1 cells. The polyGln RAN protein was undetectable in all three cell types with both approaches. Immunoblots revealed a 42 kD polyGln containing protein, which was most likely the TATA-box-binding protein. Immunofluorescence revealed a cytoplasmic aggregate, which co-localized with the Golgi apparatus. Taken together, DM1-AS transcript levels were lower in patients compared to controls and a small portion of the transcripts included the expanded repeat. However, RAN translation was not present in patient-derived DM1 cells, or was in undetectable quantities for the available methods.

Objective: To investigate PGRMC1-precipitating proteins in human endometrial stromal cells (ESC) to understand its role during in vitro decidualization., Design: Prospective observational study., Setting: Academic fertility center., Patient(s): Fifteen fertile oocyte donors., Intervention(s): Isolated ESCs decidualized in vitro and used in pulldown assays., Main Outcome Measure(s): GST-PGRMC1-precipitated proteins identified in nondecidualized ESC (ndESC) and ESC decidualized via a long (8 days) or short (4 days) decidualization protocol (dESC)., Result(s): Using pulldown assays and mass spectrometry, decidualization was evaluated by prolactin secretion (ELISA) and cytoskeleton morphology (F-actin staining). The protein interactions were validated by colocalization and coimmunoprecipitation. The pulldown and mass spectrometry analysis identified 21, 24, and 24 new significant GST-PGRMC1-precipitated proteins in ndESC, long dESC, and short dESC, respectively, compared with controls. The functional annotation analysis categorized these proteins mainly into endomembrane system and mitochondria cellular components, both related to adenosine triphosphate (ATP) generation and transport activity, protein biosynthesis and posttranslational processing, vesicle trafficking, and protection against oxidative stress activities. Monoamine oxidase B (MAOB) and B-cell receptor-associated protein 31 (BAP31) were identified in dESC from both decidualization protocols. PGRMC1-MAOB/BAP31 interactions were confirmed by immunofluorescence and coimmunoprecipitation in dESC., Conclusion(s): Novel GST-PGRMC1-precipitated proteins discovered in ESC suggest that this protein is implicated in deep remodeling of ESC during decidualization and aggregates mainly with proteins involved in biosynthesis, intracellular transport, and mitochondrial activity., (Copyright © 2020 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.)

Huntington's disease (HD) is an inherited, dominant neurodegenerative disorder caused by an abnormal expansion of CAG triplets in the huntingtin gene (htt). Despite extensive efforts to modify the progression of HD thus far only symptomatic treatment is available. Recent work suggests that treating invertebrate and mice HD models with metformin, a well-known AMPK activator which is used worldwide to treat type 2-diabetes, reduces mutant huntingtin from cells and alleviates many of the phenotypes associated to HD. Herein we report statistical analyses of a sample population of participants in the Enroll-HD database, a world-wide observational study on HD, to assess the effect of metformin intake in HD patients respect to cognitive status using linear models. This cross-sectional study shows for the first time that the use of metformin associates with better cognitive function in HD patients.