Rett Syndrome, Epigenetics, PTSD, Stress, Vulnerability, Prevention, Early Diagnosis, Gender differences, Machine Learning, Deep Learning, Computer Vision
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Scopus Publications
Scopus Publications
Systemic administration of the OGT inhibitor OSMI-1 normalizes hippocampal O-GlcNAcylation and improves recognition memory, redox balance, and brain mitochondrial homeostasis in a Rett syndrome mouse model Chiara Sette, Chiara Urbinati, Chiara Lanzillotta, Francesca Prestia, Letizia Ciafardini, Livia Cosentino, Donatella Pietraforte, Maria Cristina Quattrini, Marzia Perluigi, Fabio Di Domenico, Bianca De Filippis Free Radical Biology and Medicine, 2026 Protein O-GlcNAcylation (O-GlcNAc) is a nutrient-responsive posttranslational modification (PTM). Proper regulation of brain O-GlcNAc levels is essential for the coupling between metabolic homeostasis and neuronal function. Abnormal O-GlcNAc levels in the brain are associated with neurodevelopmental and neurodegenerative diseases related to defects in energy metabolism. We investigated the levels and regulation of protein O-GlcNAc modification and related pathways through gene and protein expression analysis in the hippocampus of two well-established murine models of Rett syndrome (RTT), a monogenic neurodevelopmental disorder with metabolic components and a primary cause of severe intellectual disability in females. Increased protein O-GlcNAc levels, due to changes in the molecular machinery that controls O-GlcNAc production, transfer, and removal, were observed in the hippocampus of the two RTT mouse models (MeCP2-BIRD and MeCP2-308 models). Remarkably, systemic administration of the OGT inhibitor OSMI-1 restored O-GlcNAc brain homeostasis and rescued brain mitochondrial defects and redox alterations in the RTT mouse hippocampus. The OSMI-1 treatment also induced a normalization of the cognitive performance of RTT mice in novel object recognition test s and reduced peripheral oxidative stress. These findings provide new evidence of an imbalance in nutrient-sensing O-GlcNAc in the RTT mouse hippocampus, suggesting that restoring brain O-GlcNAc homeostasis might represent a promising therapeutic approach for RTT. • Mouse models of Rett syndrome demonstrate increased levels of protein O-GlcNAc in the hippocampus. • Elevated O-GlcNAc levels are associated with alterations in the molecular machinery that controls transfer and removal. • Systemic administration of the OGT inhibitor OSMI-1 restored brain O-GlcNAc homeostasis. • OSMI-1 treatment improved recognition memory in RTT mice • OSMI-1 treatment decreased oxidative stress and restored mitochondrial function in the brain.
Pharmacological inhibition of the CB1 cannabinoid receptor restores abnormal brain mitochondrial CB1 receptor expression and rescues bioenergetic and cognitive defects in a female mouse model of Rett syndrome Livia Cosentino, Chiara Urbinati, Chiara Lanzillotta, Domenico De Rasmo, Daniela Valenti, Mattia Pellas, Maria Cristina Quattrini, Fabiana Piscitelli, Magdalena Kostrzewa, Fabio Di Domenico, Donatella Pietraforte, Tiziana Bisogno, Anna Signorile, Rosa Anna Vacca, Bianca De Filippis Molecular Autism, 2024 BACKGROUND: Defective mitochondria and aberrant brain mitochondrial bioenergetics are consistent features in syndromic intellectual disability disorders, such as Rett syndrome (RTT), a rare neurologic disorder that severely affects mainly females carrying mutations in the X-linked MECP2 gene. A pool of CB1 cannabinoid receptors (CB1R), the primary receptor subtype of the endocannabinoid system in the brain, is located on brain mitochondrial membranes (mtCB1R), where it can locally regulate energy production, synaptic transmission and memory abilities through the inhibition of the intra-mitochondrial protein kinase A (mtPKA). In the present study, we asked whether an overactive mtCB1R-mtPKA signaling might underlie the brain mitochondrial alterations in RTT and whether its modulation by systemic administration of the CB1R inverse agonist rimonabant might improve bioenergetics and cognitive defects in mice modeling RTT. METHODS: Rimonabant (0.3 mg/kg/day, intraperitoneal injections) was administered daily to symptomatic female mice carrying a truncating mutation of the Mecp2 gene and its effects on brain mitochondria functionality, systemic oxidative status, and memory function were assessed. RESULTS: mtCB1R is overexpressed in the RTT mouse brain. Subchronic treatment with rimonabant normalizes mtCB1R expression in RTT mouse brains, boosts mtPKA signaling, and restores the defective brain mitochondrial bioenergetics, abnormal peripheral redox homeostasis, and impaired cognitive abilities in RTT mice. LIMITATIONS: The lack of selectivity of the rimonabant treatment towards mtCB1R does not allow us to exclude that the beneficial effects exerted by the treatment in the RTT mouse model may be ascribed more broadly to the modulation of CB1R activity and distribution among intracellular compartments, rather than to a selective effect on mtCB1R-mediated signaling. The low sample size of few experiments is a further limitation that has been addressed replicating the main findings under different experimental conditions. CONCLUSIONS: The present data identify mtCB1R overexpression as a novel molecular alteration in the RTT mouse brain that may underlie defective brain mitochondrial bioenergetics and cognitive dysfunction.
Methyl-CpG binding protein 2 expression is associated with symptom severity in patients with PTSD in a sex-dependent manner Livia Cosentino, Stephanie H. Witt, Helene Dukal, Francesca Zidda, Sebastian Siehl, Herta Flor, Bianca De Filippis Translational Psychiatry, 2023 Traumatic events may lead to post-traumatic stress disorder (PTSD), with higher prevalence in women. Adverse childhood experiences (ACE) increase PTSD risk in adulthood. Epigenetic mechanisms play important roles in PTSD pathogenesis and a mutation in the methyl-CpG binding protein 2 (MECP2) in mice provide susceptibility to PTSD-like alterations, with sex-dependent biological signatures. The present study examined whether the increased risk of PTSD associated with ACE exposure is accompanied by reduced MECP2 blood levels in humans, with an influence of sex. MECP2 mRNA levels were analyzed in the blood of 132 subjects (58 women). Participants were interviewed to assess PTSD symptomatology, and asked to retrospectively report ACE. Among trauma-exposed women, MECP2 downregulation was associated with the intensification of PTSD symptoms linked to ACE exposure. MECP2 expression emerges as a potential contributor to post-trauma pathophysiology fostering novel studies on the molecular mechanisms underlying its potential sex-dependent role in PTSD onset and progression.
Effects of the Rho GTPase-activating toxin CNF1 on fibroblasts derived from Rett syndrome patients: A pilot study Camilla Cittadini, Elena Angela Pia Germinario, Zaira Maroccia, Livia Cosentino, Valeria Maselli, Lucrezia Gambardella, Massimo Giambenedetti, Marco Guidotti, Sara Travaglione, Chiara Fallerini, Alessandra Renieri, David Israel Escobar Marcillo, Laura Ricceri, Paola Fortini, Bianca De Filippis, Carla Fiorentini, Alessia Fabbri Journal of Cellular and Molecular Medicine, 2023 The bacterial product CNF1, through its action on the Rho GTPases, is emerging as a modulator of crucial signalling pathways involved in selected neurological diseases characterized by mitochondrial dysfunctions. Mitochondrial impairment has been hypothesized to have a key role in paramount mechanisms underlying Rett syndrome (RTT), a severe neurologic rare disorder. CNF1 has been already reported to have beneficial effects in mouse models of RTT. Using human RTT fibroblasts from four patients carrying different mutations, as a reliable disease-in-a-dish model, we explored the cellular and molecular mechanisms, which can underlie the CNF1-induced amelioration of RTT deficits. We found that CNF1 treatment modulates the Rho GTPases activity of RTT fibroblasts and induces a considerable re-organization of the actin cytoskeleton, mainly in stress fibres. Mitochondria of RTT fibroblasts show a hyperfused morphology and CNF1 decreases the mitochondrial mass leaving substantially unaltered the mitochondrial dynamic. From a functional perspective, CNF1 induces mitochondrial membrane potential depolarization and activation of AKT in RTT fibroblasts. Given that mitochondrial quality control is altered in RTT, our results are suggestive of a reactivation of the damaged mitochondria removal via mitophagy restoration. These effects can be at the basis of the beneficial effects of CNF1 in RTT.
Low levels of Methyl-CpG binding protein 2 are accompanied by an increased vulnerability to the negative outcomes of stress exposure during childhood in healthy women Livia Cosentino, Francesca Zidda, Helene Dukal, Stephanie H. Witt, Bianca De Filippis, Herta Flor Translational Psychiatry, 2022 Numerous mental illnesses arise following stressful events in vulnerable individuals, with females being generally more affected than males. Adverse childhood experiences are known to increase the risk of developing psychopathologies and DNA methylation was demonstrated to drive the long-lasting effects of early life stress and promote stress susceptibility. Methyl-CpG binding protein 2 (MECP2), an X-linked reader of the DNA methylome, is altered in many mental disorders of stress origin, suggesting MECP2 as a marker of stress susceptibility; previous works also suggest a link between MECP2 and early stress experiences. The present work explored whether a reduced expression of MECP2 is paralleled by an increased vulnerability to the negative outcomes of stress exposure during childhood. To this aim, blood MECP2 mRNA levels were analyzed in 63 people without history of mental disorders and traits pertaining to depressive and anxiety symptom clusters were assessed as proxies of the vulnerability to develop stress-related disorders; stress exposure during childhood was also evaluated. Using structural equation modeling, we demonstrate that reduced MECP2 expression is accompanied by symptoms of anxiety/depression in association with exposure to stress in early life, selectively in healthy women. These results suggest a gender-specific involvement of MECP2 in the maladaptive outcomes of childhood adversities, and shed new light on the complex biology underlying gender bias in stress susceptibility.
Treatment with FRAX486 rescues neurobehavioral and metabolic alterations in a female mouse model of CDKL5 deficiency disorder Claudia Fuchs, Livia Cosentino, Chiara Urbinati, Maria Cristina Talamo, Giorgio Medici, Maria Cristina Quattrini, Nicola Mottolese, Donatella Pietraforte, Andrea Fuso, Elisabetta Ciani, Bianca De Filippis CNS Neuroscience and Therapeutics, 2022 INTRODUCTION CDKL5 deficiency disorder (CDD) is a rare neurodevelopmental condition, primarily affecting girls for which no cure currently exists. Neuronal morphogenesis and plasticity impairments as well as metabolic dysfunctions occur in CDD patients. The present study explored the potential therapeutic value for CDD of FRAX486, a brain-penetrant molecule that was reported to selectively inhibit group I p21-activated kinases (PAKs), serine/threonine kinases critically involved in the regulation of neuronal morphology and glucose homeostasis. METHODS The effects of treatment with FRAX486 on CDD-related alterations were assessed in vitro (100 nM for 48 h) on primary hippocampal cultures from Cdkl5-knockout male mice (Cdkl5-KO) and in vivo (20 mg/Kg, s.c. for 5 days) on Cdkl5-KO heterozygous females (Cdkl5-Het). RESULTS The in vitro treatment with FRAX486 completely rescued the abnormal neuronal maturation and the number of PSD95-positive puncta in Cdkl5-KO mouse neurons. In vivo, FRAX486 normalized the general health status, the hyperactive profile and the fear learning defects of fully symptomatic Cdkl5-Het mice. Systemically, FRAX486 treatment normalized the levels of reactive oxidizing species in the whole blood and the fasting-induced hypoglycemia displayed by Cdkl5-Het mice. In the hippocampus of Cdkl5-Het mice, treatment with FRAX486 rescued spine maturation and PSD95 expression and restored the abnormal PAKs phosphorylation at sites which are critical for their activation (P-PAK-Ser144/141/139) or for the control cytoskeleton remodeling (P-PAK1-Thr212). CONCLUSIONS Present results provide evidence that PAKs may represent innovative therapeutic targets for CDD.
Methyl-CpG binding protein 2 dysfunction provides stress vulnerability with sex- and zygosity-dependent outcomes Livia Cosentino, Fabio Bellia, Nicole Pavoncello, Daniele Vigli, Claudio D'Addario, Bianca De Filippis European Journal of Neuroscience, 2022 Stress vulnerability is a critical factor for the development of trauma-related disorders, however its biological underpinnings are not clear. We demonstrated that dysfunctions in the X-linked epigenetic factor methyl-CpG binding protein 2 (MeCP2) provide trauma vulnerability in male mice. Given the prominent role of sex in stress outcomes, we explored the effects of MeCP2 hypofunctionality in females. Female mice carrying truncated MeCP2 (heterozygous and homozygous) and wild type controls (wt) were tested for fear memory. Stress-induced corticosterone release and brain expression of hypothalamic-pituitary-adrenal (HPA) axis regulatory genes were also evaluated in wt and mutant mice of both sexes. While heterozygous females displayed a normal stress-related behavioral profile, homozygous mice showed enhanced memory recall for the threatening context compared to wt, thus recapitulating the phenotype previously evidenced in hemizygous males. Interestingly, MeCP2 truncation abolished the sex differences in stress-induced corticosterone release, which was found increased in mutant males, while blunted in mutant females in a zygosity-independent manner. While heterozygous mice did not differ from controls, homozygous females and hemizygous males showed increased hypotalamic Crh and Avp mRNAs and a differentially altered expression of Fkbp5 in cortical areas. Present results demonstrate that in female mice carrying truncated MeCP2 altered stress responsivity is driven by homozygosity, while heterozygosity does not lead to maladaptive stress outcomes. MeCP2 dysfunctions thus provide stress vulnerability in mice with sex- and zygosity-dependent outcomes.
Treatment with the bacterial toxin cnf1 selectively rescues cognitive and brain mitochondrial deficits in a female mouse model of rett syndrome carrying a mecp2-null mutation Chiara Urbinati, Livia Cosentino, Elena Angela Pia Germinario, Daniela Valenti, Daniele Vigli, Laura Ricceri, Giovanni Laviola, Carla Fiorentini, Rosa Anna Vacca, Alessia Fabbri, Bianca De Filippis International Journal of Molecular Sciences, 2021 Rett syndrome (RTT) is a rare neurological disorder caused by mutations in the X-linked MECP2 gene and a major cause of intellectual disability in females. No cure exists for RTT. We previously reported that the behavioural phenotype and brain mitochondria dysfunction are widely rescued by a single intracerebroventricular injection of the bacterial toxin CNF1 in a RTT mouse model carrying a truncating mutation of the MeCP2 gene (MeCP2-308 mice). Given the heterogeneity of MECP2 mutations in RTT patients, we tested the CNF1 therapeutic efficacy in a mouse model carrying a null mutation (MeCP2-Bird mice). CNF1 selectively rescued cognitive defects, without improving other RTT-related behavioural alterations, and restored brain mitochondrial respiratory chain complex activity in MeCP2-Bird mice. To shed light on the molecular mechanisms underlying the differential CNF1 effects on the behavioural phenotype, we compared treatment effects on relevant signalling cascades in the brain of the two RTT models. CNF1 provided a significant boost of the mTOR activation in MeCP2-308 hippocampus, which was not observed in the MeCP2-Bird model, possibly explaining the differential effects of CNF1. These results demonstrate that CNF1 efficacy depends on the mutation beared by MeCP2-mutated mice, stressing the need of testing potential therapeutic approaches across RTT models.
Stimulation of the Serotonin Receptor 7 Restores Brain Histone H3 Acetylation and MeCP2 Corepressor Protein Levels in a Female Mouse Model of Rett Syndrome Giorgia Napoletani, Daniele Vigli, Livia Cosentino, Maddalena Grieco, Maria Cristina Talamo, Enza Lacivita, Marcello Leopoldo, Giovanni Laviola, Andrea Fuso, Maria d’Erme, Bianca De Filippis Journal of Neuropathology and Experimental Neurology, 2021 Rett syndrome (RTT) is a rare neurological disorder caused by mutations in the X-linked MECP2 gene, characterized by severe behavioral and physiological impairments for which no cure is available. The stimulation of serotonin receptor 7 (5-HT7R) with its selective agonist LP-211 (0.25 mg/kg/day for 7 days) was proved to rescue neurobehavioral alterations in a mouse model of RTT. In the present study, we aimed at gaining insight into the mechanisms underpinning the efficacy of 5-HT7R pharmacological stimulation by investigating its epigenetic outcomes in the brain of RTT female mice bearing a truncating MeCP2 mutation. Treatment with LP-211 normalized the reduced histone H3 acetylation and HDAC3/NCoR levels, and increased HDAC1/Sin3a expression in RTT mouse cortex. Repeated 5-HT7R stimulation also appeared to strengthen the association between NCoR and MeCP2 in the same brain region. A different profile was found in RTT hippocampus, where LP-211 rescued H3 hyperacetylation and increased HDAC3 levels. Overall, the present data highlight a new scenario on the relationship between histone acetylation and serotoninergic pathways. 5-HT7R is confirmed as a pivotal therapeutic target for the recovery of neuronal function supporting the translational value of this promising pharmacological approach for RTT.
