title: Loss of function mutations in the progranulin gene are related to pro-inflammatory cytokine dysregulation in frontotemporal lobar degeneration patients.
abstract: The progranulin gene (PGRN) encodes a pleiotropic molecule with anti-inflammatory actions and neuronal protective effects. Accordingly, PGRN-deficient mice have been demonstrated to develop enhanced inflammation and progressive neurodegeneration. Loss of function mutations of the PGRN gene have been also reported to cause frontotemporal lobar degeneration (FTLD), a neurodegenerative disease leading to dementia generally in the presenium. Since neurodegeneration might be negatively impacted by chronic inflammation, the possible influence of PGRN defects on inflammatory pathways appears to be of great relevance for the understanding of neurodegeneration pathogenic processes in those patients. However, no data about the inflammatory profile of PGRN-defective subjects have been so far provided.In this study, we analyzed serum levels of the pro-inflammatory mediators IL-6, TNF-α and IL-18 in FTLD patients with or without PGRN mutations, at both pre-symptomatic and symptomatic stages. We provide evidence that circulating IL-6 is increased in PGRN-mutated FTLD patients, as compared to both PGRN non-mutated FTLD patients and controls. In contrast, levels of IL-6 were not altered in asymptomatic subjects carrying the PGRN mutations. Finally, TNF-α and IL-18 serum levels did not differ among all groups of included subjects.We conclude that the profile of circulating pro-inflammatory cytokines is altered in PGRN-related symptomatic FTLD. Thus, our findings point to IL-6 as a possible specific mediator and a potential therapeutic target in this monogenic disease, suggesting that an enhanced inflammatory response might be indeed involved in its progression.
authors.affiliation: IRCCS Santa Lucia Foundation, Rome, Italy. p.bossu@hsantalucia.it
authors.forename: Paola
authors.initials: P
authors.lastname: Bossù
authors.forename: Francesca
authors.initials: F
authors.lastname: Salani
authors.forename: Antonella
authors.initials: A
authors.lastname: Alberici
authors.forename: Silvana
authors.initials: S
authors.lastname: Archetti
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Bellelli
authors.forename: Daniela
authors.initials: D
authors.lastname: Galimberti
authors.forename: Elio
authors.initials: E
authors.lastname: Scarpini
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Spalletta
authors.forename: Carlo
authors.initials: C
authors.lastname: Caltagirone
authors.forename: Alessandro
authors.initials: A
authors.lastname: Padovani
authors.forename: Barbara
authors.initials: B
authors.lastname: Borroni
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D016207:Cytokines / Q000378:metabolism*; D018450:Disease Progression; D005260:Female; D057174:Frontotemporal Lobar Degeneration / Q000097:blood* / Q000235:genetics* / Q000276:immunology* / Q000503:physiopathology; D006801:Humans; D007249:Inflammation / Q000276:immunology / Q000503:physiopathology; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism; D020382:Interleukin-18 / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D051379:Mice; D008875:Middle Aged; D009154:Mutation; D000077153:Progranulins; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D016207:Cytokines; C492314:GRN protein, human; D036341:Intercellular Signaling Peptides and Proteins; D020382:Interleukin-18; D015850:Interleukin-6; D000077153:Progranulins; D014409:Tumor Necrosis Factor-alpha