👤 Ester Pagano

G-quadruplexes (G4s) are non-canonical secondary nucleic acid structures with important biological implications in telomere elongation and gene expression. A large number of small molecules have been developed to bind and even covalently target these structures, enhancing the potency and duration of binding. Alternatively, peptide-based ligands have been studied and shown to offer several advantages, including high specificity, a modular design, and ease of synthesis. In this work, we describe a peptide-based methodology for covalent G4-targeting, based on the introduction of two photoactivatable moieties in a peptide derived from the RHAU helicase. Rational insertion of crosslinkers at different positions yielded nine different peptides, which were evaluated for their G4-stabilizing effect and alkylation potential. Moderate to high alkylation yields towards G4s were obtained. The G4 stabilizing potential drastically increased for N-terminal modifications of the RHAU18 peptide. This led to the design of a further series of peptides with varying N-terminal residues to gain insight in the stabilization potential of each single amino acid modification and provided a comprehensive study of the binding behaviour of modified RHAU peptides. Show less

The long-term effects of SARS-CoV-2 infection are increasingly recognized, with heterogeneous physical and psychological symptoms that may persist for months, significantly affecting Health Related Quality of Life (HRQoL), functional capacity, and psychosocial well-being. This study explores distinct profiles of HRQoL and psychological symptoms in former COVID-19 inpatients and assesses the impact of clinical variables at admission on long-term outcomes. Patients hospitalised for COVID-19 at Molinette Hospital in Turin were contacted several months post-discharge (between June 2022 and June 2023) to complete a questionnaire assessing long-term HRQoL, sleep quality, depression, anxiety, stress, and fatigue. Clinical data at the time of hospitalisation were also available for each participant. A Latent Profile Analysis (LPA) was conducted on these physical and psychological variables, followed by multinomial logistic regression to examine how selected indicators of baseline COVID-19 severity and patient characteristics predicted profile membership. The sample consisted of 601 patients. LPA identified three health-related profiles: This study highlights a wide spectrum of post-COVID-19 conditions, ranging from good to severely compromised physical and mental health. Female gender, presence of comorbidities, and elevated early warning scores at hospital admission are risk factors for worse outcomes, emphasizing the need for comprehensive long-term care. The online version contains supplementary material available at 10.1007/s11136-026-04206-y. Show less

A small fraction of the proteins present in human plasma can be found as circulating protein aggregates. Such aggregates are formed by prone to aggregation proteins and different stimuli promote the aggregation process. Fe(III) is a redox active metal ion which also actively interacts with proteins. The aim of this work is to identify the prone to aggregation plasma proteins in presence of Fe(III) in order to outline potential targets of these circulating protein aggregates. Here we show that Fe(III) induces the formation of protein aggregates from human plasma proteins. A concentration of 100 μM Fe(III) aggregates roughly 5 % of the total plasma protein assayed. When assayed by SDS-PAGE/silver-staining, a rather homogeneous aggregate can be observed with one major protein with a molecular weight matching that of immunoglobulin G (IgG) (150k Da). Additionally, the band corresponding to albumin (66 kDa) which is the main plasma protein was absent. The identity of IgG within the aggregate and albumin depletion was corroborated by liquid chromatography-mass spectrometry. Additionally, some other proteins could be identified within the aggregate such as fibrinogen, fibronectin and Apo-B. Then, the identity of the IgG and depletion of albumin was corroborated by Western blot. It should be noted that aggregated IgGs are strong activators of inflammatory pathways involving neutrophil oxidative burst, complement cascade activation and platelet release of active amines. Therefore, the existence of a potential link between the formation of Fe(III)-induced protein aggregates and inflammation should be further explored. Show less

Bladder cancer (BCa) is a lethal cancer, but early-detection offers an opportunity to improve prognosis. Our objective was to develop a urine-based multi-marker panel for BCa detection across multiple longitudinal cohort studies in a nested case-control study. Longitudinal cohorts included healthy participants enrolled in the Southern Community Cohort Study (SCCS), Singapore Chinese Health Study (SCHS), Shanghai Women/Men Health Study (SWMHS), and Multiethnic Cohort (MEC). We measured the levels of 10 protein biomarkers (A1AT, ANG, APOE, CA9, IL8, MMP9, MMP10, PAI1, SDC1, and VEGF) in spot-voided urine samples using the multiplex immunoassay Oncuria. Single urine specimens collected from 274 participants who would go on to develop BCa in the ensuing 3‒60 months (i.e., cases) were age/sex-matched to 274 cancer-free controls. We used generalized estimating equation models, logistic regression analysis, and random forest algorithms to analyze the data. Differences in the individual biomarker levels between cases and controls were noted for ANG at 12 months ( Additional testing is needed; however preliminary results demonstrate that a multiplex immunoassay may be able to facilitate the early detection of BCa in at-risk patients. Identification of BCa at an early stage may lead to improved patient outcomes. Using large multinational patient populations, we tested the performance of the Oncuria multiplex assay to accurately predict the risk of developing bladder cancer by simultaneously analyzing the concentrations of 10 protein biomarkers in urine samples. The online version contains supplementary material available at 10.1186/s12967-025-07511-1. Show less

The cellular networks that maintain genome stability encompass numerous pathways involved in all aspects of nucleic acid metabolism. Through bioinformatic analysis, we identified the Zinc Finger CCCH-Type Containing 4 protein (ZC3H4), a suppressor of noncoding RNA (ncRNA) production, as a pivotal player in this system. Experimentally, ZC3H4 deficiency led to increased DNA damage, abnormal mitosis, and cellular senescence. Biochemical analysis and super-resolution microscopy revealed that the loss of ZC3H4 increased replication stress (RS)-a major driver of genome instability-by inducing a hypertranscription state that promoted R loop formation and transcription-replication conflicts (TRCs), both of which drive RS. Further bioinformatic analysis demonstrated that ZC3H4 preferentially binds to genomic regions prone to TRCs and R loops, where it suppresses ncRNA bursts, functioning as part of the Restrictor complex. Our findings identify ZC3H4 as a crucial factor in maintaining genome integrity, strategically positioned at the critical intersection of DNA and RNA synthesis. Show less

The human formyl-peptide receptor 2 (FPR2) is activated by an array of ligands. By phospho-proteomic analysis we proved that FPR2 stimulation induces redox-regulated phosphorylation of many proteins involved in cellular metabolic processes. In this study, we investigated metabolic pathways activated in FPR2-stimulated CaLu-6 cells. The results showed an increased concentration of metabolites involved in glucose metabolism, and an enhanced uptake of glucose mediated by GLUT4, the insulin-regulated member of GLUT family. Accordingly, we observed that FPR2 transactivated IGF-IR Show less

PTB (PhosphoTyrosine Binding) domains are protein domains that exert their function by binding phosphotyrosine residues on other proteins. They are commonly found in a variety of signaling proteins and are important for mediating protein-protein interactions in numerous cellular processes. PTB domains can also exhibit binding to unphosphorylated ligands, suggesting that they have additional binding specificities beyond phosphotyrosine recognition. Structural studies have reported that the PTB domain from FRS2 possesses this peculiar feature, allowing it to interact with both phosphorylated and unphosphorylated ligands, such as TrkB and FGFR1, through different topologies and orientations. In an effort to elucidate the dynamic and functional properties of these protein-protein interactions, we provide a complete characterization of the folding mechanism of the PTB domain of FRS2 and the binding process to peptides mimicking specific regions of TrkB and FGFR1. By analyzing the equilibrium and kinetics of PTB folding, we propose a mechanism implying the presence of an intermediate along the folding pathway. Kinetic binding experiments performed at different ionic strengths highlighted the electrostatic nature of the interaction with both peptides. The specific role of single amino acids in early and late events of binding was pinpointed by site-directed mutagenesis. These results are discussed in light of previous experimental works on these protein systems. Show less

Chronic lymphocytic leukemia (CLL) is the most common adult leukemia in the western world. It is characterized by a high dependency on interactions with the surrounding immune landscape, highlighting its suitability for immune-mediated therapeutic interventions. We recently revealed that the cytokine IL-27 exerts a strong anti-tumor role in CLL through a T-cell-mediated mechanism. Show less

Chronic lymphocytic leukemia (CLL) cells are highly dependent on interactions with the immunosuppressive tumor microenvironment (TME) for survival and proliferation. In the search for novel treatments, pro-inflammatory cytokines have emerged as candidates to reactivate the immune system. Among those, interleukin 27 (IL-27) has recently gained attention, but its effects differ among malignancies. Here, we utilized the Eμ-TCL1 and EBI3 knock-out mouse models as well as clinical samples from patients to investigate the role of IL-27 in CLL. Characterization of murine leukemic spleens revealed that the absence of IL-27 leads to enhanced CLL development and a more immunosuppressive TME in transgenic mice. Gene-profiling of T-cell subsets from EBI3 knock-out highlighted transcriptional changes in the CD8+ T-cell population associated with T-cell activation, proliferation, and cytotoxicity. We also observed an increased anti-tumor activity of CD8+ T cells in the presence of IL-27 ex vivo with murine and clinical samples. Notably, IL-27 treatment led to the reactivation of autologous T cells from CLL patients. Finally, we detected a decrease in IL-27 serum levels during CLL development in both pre-clinical and patient samples. Altogether, we demonstrated that IL-27 has a strong anti-tumorigenic role in CLL and postulate this cytokine as a promising treatment or adjuvant for this malignancy. Show less

Immune-checkpoint blockade has revolutionized cancer treatment, but some cancers, such as acute myeloid leukemia (AML), do not respond or develop resistance. A potential mode of resistance is immune evasion of T cell immunity involving aberrant major histocompatibility complex class I (MHC-I) antigen presentation (AP). To map such mechanisms of resistance, we identified key MHC-I regulators using specific peptide-MHC-I-guided CRISPR-Cas9 screens in AML. The top-ranked negative regulators were surface protein sushi domain containing 6 (SUSD6), transmembrane protein 127 (TMEM127), and the E3 ubiquitin ligase WWP2. SUSD6 is abundantly expressed in AML and multiple solid cancers, and its ablation enhanced MHC-I AP and reduced tumor growth in a CD8 Show less

Melanocortin receptor-4 (MC4R) gene mutations are associated with early-onset severe obesity, and the identification of potential pathological variants is crucial for the clinical management of patients with obesity. To explore whether and how a novel heterozygous MC4R variant (MC4R-F313Sfs*29), identified in a young boy (body mass index [BMI] 38.8 kg/m2) during a mutation analysis conducted in a cohort of patients with obesity, plays a determinant pathophysiological role in the obesity development. The genetic screening was carried out in a total of 209 unrelated patients with obesity (BMI ≥ 35 kg/m2). Structural and functional characterization of the F313Sfs*29-mutated MC4R was performed using computational approaches and in vitro, using HEK293 cells transfected with genetically encoded biosensors for cAMP and Ca2+. The F313Sfs*29 was the only variant identified. In vitro experiments showed that HEK293 cells transfected with the mutated form of MC4R did not increase intracellular cAMP or Ca2+ levels after stimulation with a specific agonist in comparison with HEK293 cells transfected with the wild type form of MC4R (∆R/R0 = -90% ± 8%; P < 0.001). In silico modeling showed that the F313Sfs*29 mutation causes a major reorganization in the cytosolic domain of MC4R, thus reducing the affinity of the putative GalphaS binding site. The newly discovered F313Sfs*29 variant of MC4R may be involved in the impairment of α-MSH-induced cAMP and Ca2+ signaling, blunting intracellular G protein-mediated signal transduction. This alteration might have led to the dysregulation of satiety signaling, resulting in hyperphagia and early onset of obesity. Show less

FBXO31 is the substrate receptor of one of many CUL1-RING ubiquitin ligase (CRL1) complexes. Here, we show that low FBXO31 mRNA levels are associated with high pre-operative prostate-specific antigen (PSA) levels and Gleason grade in human prostate cancer. Mechanistically, the ubiquitin ligase CRL1 Show less

Pulmonary arterial hypertension (PAH) is a fatal cardiopulmonary disease characterized by increased vascular cell proliferation with apoptosis resistance and occlusive remodeling of the small pulmonary arteries. The Notch family of proteins subserves proximal signaling of an evolutionarily conserved pathway that effects cell proliferation, fate determination, and development. In endothelial cells (ECs), Notch receptor 2 (Notch2) was shown to promote endothelial apoptosis. However, a pro- or antiproliferative role for Notch2 in pulmonary endothelial proliferation and ensuing PAH is unknown. We postulated that suppressed Notch2 signaling drives pulmonary endothelial proliferation in the context of PAH. We observed that levels of Notch2 are ablated in lungs from PAH subjects compared with non-PAH controls. Notch2 expression was attenuated in human pulmonary artery endothelial cells (hPAECs) exposed to vasoactive stimuli including hypoxia, TGF-β, ET-1, and IGF-1. Notch2-deficient hPAECs activated Akt, Erk1/2, and antiapoptotic protein Bcl-2 and reduced levels of p21 Show less

Vascular hyperproliferative disorders are characterized by excessive smooth muscle cell (SMC) proliferation leading to vessel remodeling and occlusion. In pulmonary arterial hypertension (PAH), SMC phenotype switching from a terminally differentiated contractile to synthetic state is gaining traction as our understanding of the disease progression improves. While maintenance of SMC contractile phenotype is reportedly orchestrated by a MEF2C-myocardin (MYOCD) interplay, little is known regarding molecular control at this nexus. Moreover, the burgeoning interest in microRNAs (miRs) provides the basis for exploring their modulation of MEF2C-MYOCD signaling, and in turn, a pro-proliferative, synthetic SMC phenotype. We hypothesized that suppression of SMC contractile phenotype in pulmonary hypertension is mediated by miR-214 via repression of the MEF2C-MYOCD-leiomodin1 (LMOD1) signaling axis. In SMCs isolated from a PAH patient cohort and commercially obtained hPASMCs exposed to hypoxia, miR-214 expression was monitored by qRT-PCR. miR-214 was upregulated in PAH- vs. control subject hPASMCs as well as in commercially obtained hPASMCs exposed to hypoxia. These increases in miR-214 were paralleled by MEF2C, MYOCD and SMC contractile protein downregulation. Of these, LMOD1 and MEF2C were directly targeted by the miR. Mir-214 overexpression mimicked the PAH profile, downregulating MEF2C and LMOD1. AntagomiR-214 abrogated hypoxia-induced suppression of the contractile phenotype and its attendant proliferation. Anti-miR-214 also restored PAH-PASMCs to a contractile phenotype seen during vascular homeostasis. Our findings illustrate a key role for miR-214 in modulation of MEF2C-MYOCD-LMOD1 signaling and suggest that an antagonist of miR-214 could mitigate SMC phenotype changes and proliferation in vascular hyperproliferative disorders including PAH. Show less