Archives of Biochemistry and Biophysics 696 (2020) 108660 Available online 5 November 2020 0003-9861/© 2020 Elsevier Inc. All rights reserved. A proteomics approach to further highlight the altered infammatory condition in Rett syndrome Vittoria Cicaloni a , Alessandra Pecorelli b , Valeria Cordone c , Laura Tinti a , Marco Rossi a , Joussef Hayek a , Laura Salvini a , Cristina Tinti a , Giuseppe Valacchi b, c, d, * a Toscana Life Science Foundation, Via Fiorentina 1, 53100, Siena, Italy b Plants for Human Health Institute, Animal Science Dept., NC Research Campus, NC State University, 600 Laureate Way, Kannapolis, NC, 28081, USA c Department of Biomedical and Specialist Surgical Sciences, University of Ferrara, Ferrara, Italy d Kyung Hee University, Department of Food and Nutrition, Seoul, South Korea A R T I C L E INFO Keywords: Rare disease Rett syndrome Infammatory status NLRP3 infammasome Mass spectrometry-based proteomics ABSTRACT Rett syndrome (RTT) is a progressive neurodevelopmental disorder caused by mutations in the X-linked MECP2 gene. RTT patients show multisystem disturbances associated with perturbed redox homeostasis and infam- mation, which appear as possible key factors in RTT pathogenesis. In this study, using primary dermal fbroblasts from control and RTT subjects, we performed a proteomic analysis that, together with data mining approaches, allowed us to carry out a comprehensive characterization of RTT cellular proteome. Functional and pathway enrichment analyses showed that differentially expressed proteins in RTT were mainly enriched in biological processes related to immune/infammatory responses. Overall, by using proteomic data mining as supportive approach, our results provide a detailed insight into the molecular pathways involved in RTT immune dysfunction that, causing tissue and organ damage, can increase the vulnerability of affected patients to un- known endogenous factors or infections. 1. Introduction Rett syndrome (RTT; OMIM 312750), a severe neurodevelopmental disorder, which predominantly affects females (about 1 per 10,000–15,000 live births), is mainly caused by sporadic loss-of- function mutations in the X-linked methyl-CpG-binding protein 2 gene (MECP2) [1–3]. Affected patients display prominent neurologic hall- marks, such as a rapid deterioration of the acquired psychomotor skills (i.e., stereotyped hand movements, absent or very limited speech, ataxia), seizures, and autistic-like behavior, which appear after a period of 6–18-months normal development [4,5]. In addition, common co-morbidities comprise sleep disturbances, breathing and cardiac problems, numerous gastrointestinal disorders, scoliosis, and osteopenia [6–10]. Rett syndrome affects different tissues and organs. It is linked to an abnormal muscular tone [11] and a vasomotor instability especially in the lower limbs [12], to a neurodevelopmental arrest followed by a regression phase where patients lose acquired language and motor skills and exhibit intellectual disability and hand stereotypies [13–15] and to a subclinical myocardial dysfunction [16]. Moreover, Rett patients frequently have marked decreases in bone mineral density leading to osteoporotic fractures [17]. Despite the well-known genetic background at the basis of Rett syndrome, the complete pathogenic mechanisms linking MeCP2 defciency to the symptoms of this broad-spectrum pa- thology remain still unclear [18]. Other factors can contribute to the complexity of the disease, indeed an aberrant immune response, an impaired redox homeostasis [19–21], a perturbed cholesterol metabolism [22,23], an altered mitochondrial bioenergetics [24], and a subclinical infammatory status [25–27] were shown to play a key role in RTT pathogenesis and progression. The condition defned as “OxInfammation”, consisting in a harmful cycle between the redox imbalance and the infammatory status, has been observed at cellular and systemic levels in both RTT patients and animal models [19]. NF-κB is a redox-sensitive transcription factor involved in innate and adaptive immune responses, as well as in infammation. Dysregulated NF-κB signaling cascade has been associated with the pathogenesis of several diseases including RTT [28,29]. Indeed, in a recent study our group demonstrated an increase of NF-κB p65 nuclear translocation * Corresponding author. North Carolina State University, Kannapolis Research Campus, USA. E-mail address: gvalacc@ncsu.edu (G. Valacchi). Contents lists available at ScienceDirect Archives of Biochemistry and Biophysics journal homepage: www.elsevier.com/locate/yabbi https://doi.org/10.1016/j.abb.2020.108660 Received 15 October 2020; Received in revised form 24 October 2020; Accepted 28 October 2020