La recherche-action participative menée au « Lieu de répit ¼ Marseille, un catalyseur de transformation sociale.

INTRODUCTION: The participatory action-research (PAR) carried out at the Lieu de Répit (LDR) (Place of Respite) accompanied the emergence of an innovative intervention model, while placing particular importance on the participation of people suffering from psychological disorders. It also produced relevant scientific results and promoted collective empowerment. PURPOSE OF RESEARCH: The article reports on a presentation at the conference “Recherches participatives en santé et bien-être des populations: défis et pratiques” (“Participatory Research in Community Health and Well-being: Challenges and Practices”), organized by the Institut pour la recherche en santé publique (IReSP) on March 9 and 10, 2022. RESULTS: Three PAR actors present situated views on interpersonal relations, the organisation of PAR, and the effects of participation. Participation is facilitated by a range of contextual, human and organisational factors. CONCLUSIONS: Although complex to implement, participatory health research is necessary for the production of new knowledge, while meeting new epistemic requirements.

MFN2-associated lipomatosis: Clinical spectrum and impact on adipose tissue.

BACKGROUND: Multiple symmetric lipomatosis (MSL) is characterized by upper-body lipomatous masses frequently associated with metabolic and neurological signs. MFN2 pathogenic variants were recently implicated in a very rare autosomal recessive form of MSL. MFN2 encodes mitofusin-2, a mitochondrial fusion protein previously involved in Charcot-Marie-Tooth neuropathy. OBJECTIVE: To investigate the clinical, metabolic, tissular, and molecular characteristics of MFN2-associated MSL. METHODS: We sequenced MFN2 in 66 patients referred for altered fat distribution with one or several lipomas or lipoma-like regions and performed clinical and metabolic investigations in patients with positive genetic testing. Lipomatous tissues were studied in 3 patients. RESULTS: Six patients from 5 families carried a homozygous p.Arg707Trp pathogenic variant, representing the largest reported series of MFN2-associated MSL. Patients presented both lipomatous masses and a lipodystrophic syndrome (lipoatrophy, low leptinemia and adiponectinemia, hypertriglyceridemia, insulin resistance and/or diabetes). Charcot-Marie-Tooth neuropathy was of highly variable clinical severity. Lipomatous tissue mainly contained hyperplastic unilocular adipocytes, with few multilocular cells. It displayed numerous mitochondrial alterations (increased number and size, structural defects). As compared to control subcutaneous fat, mRNA and protein expression of leptin and adiponectin was strikingly decreased, whereas the CITED1 and fibroblast growth factor 21 (FGF21) thermogenic markers were strongly overexpressed. Consistently, serum FGF21 was markedly increased, and 18F-FDG-PET-scan revealed increased fat metabolic activity. CONCLUSION: MFN2-related MSL is a novel mitochondrial lipodystrophic syndrome involving both lipomatous masses and lipoatrophy. Its complex neurological and metabolic phenotype justifies careful clinical evaluation and multidisciplinary care. Low leptinemia and adiponectinemia, high serum FGF21, and increased 18F-FDG body fat uptake may be disease markers.