Francesca Antonia Schillaci

Background/Objectives: Dilated cardiomyopathy (DCM) is a genetically heterogeneous myocardial disorder. Emerging evidence suggests that some genes implicated in DCM may also be associated with neurological disorders, supporting the concept of genetic pleiotropy. This study explored the intersection between cardiac and neurological genetics, with the aim of identifying candidate genes that may contribute to shared pathogenic pathways linking these clinically distinct conditions. Methods: We performed exome sequencing in 149 patients with echocardiographically confirmed DCM and subsequently applied an in silico filter to a predefined list of 211 genes associated with inherited cardiomyopathies. Variants were classified according to the American College of Medical Genetics and Genomics (ACMG) criteria. Genes with validated evidence for DCM according to the Clinical Genome Resource (ClinGen) were further investigated through the Human Gene Mutation Database (HGMD) and a focused literature review to identify reported associations with neurological disorders. Results: Genetic variants in DCM-associated genes were identified in 105 patients. Overall, 137 variants were detected, including pathogenic variants and variants of uncertain significance. The most frequently involved genes were TTN, FLNC, and MYH6. Several DCM-associated genes also showed reported associations with neurological disorders, including autism spectrum disorder, Alzheimer’s disease, Parkinson’s disease, epilepsy, and schizophrenia. Among them, TTN, FLNC, RYR2, and SCN5A displayed the broadest overlap between cardiac and neurological phenotypes. Conclusions: These descriptive findings show that variants were most frequently observed in TTN, FLNC, and MYH6 and that several genes included in the ClinGen DCM curation framework have also been independently reported in neurological disorders. Because most identified variants were VUS and no control group or systematic neurological phenotyping was available, the findings indicate gene-level co-annotation only and do not establish variant enrichment, shared pathogenic mechanisms, or clinical overlap.

Background: Autism spectrum disorder (ASD) is a highly prevalent neurodevelopmental condition influenced by both genetic and non-genetic factors, although the underlying pathomechanisms remain unclear. We systematically analyzed microRNA (miRNA) expression and associated functional pathways in ASD to evaluate their potential as prenatal/postnatal, diagnostic, and prognostic biomarkers. Methods: Peripheral blood mononuclear cells from 12 Sicilian patients with ASD (eight with normal cognitive function) and 15 healthy controls were analyzed using small RNA sequencing. Differential expression analysis was performed with DESeq2 (|fold change| ≥ 1.5; adjusted p ≤ 0.05). Functional enrichment and network analyses were conducted using Ingenuity Pathway Analysis, focusing on Diseases and Biofunctions. Results: 998 miRNAs were differentially expressed in ASD, 424 upregulated and 553 downregulated. Enriched pathways were primarily associated with psychological and neurological disorders. Network analysis highlighted three principal interaction clusters related to inflammation, cell survival and mechanotransduction, synaptic plasticity, and neuronal excitability. Four miRNAs (miR-296-3p, miR-27a, miR-146a-5p, and miR-29b-3p) emerged as key regulatory candidates. Conclusions: The marked divergence in miRNA expression between ASD and controls suggests distinct regulatory patterns, thus reinforcing the central involvement of inflammatory, autoimmune, and infectious mechanisms in ASD, mediated by miRNAs regulating S100 family genes, neuronal migration, and synaptic communication. However, rather than defining a predictive biomarker panel, this study identified candidate miRNAs and regulatory networks that may be relevant to ASD pathophysiology. As such, further validation in appropriately powered cohorts with predictive modeling frameworks are warranted before any biomarker or diagnostic implications can be inferred.

Background/Objectives: Parkinson’s disease (PD) is an adult-onset neurodegenerative disorder whose pathogenesis is still not completely understood. Several lines of evidence suggest that alterations in epigenetic architecture may contribute to the development of this condition. Here, we present a pilot DNA methylation study from peripheral blood in a cohort of Sicilian PD patients and matched controls. Peripheral tissue analysis has previously been shown to reflect molecular and functional profiles relevant to neurological diseases, supporting their validity as a proxy for studying brain-related epigenetic mechanisms. Methods: We analyzed 20 PD patients and 20 healthy controls (19 males and 21 females overall), matched for sex, with an age range of 60–87 years (mean 72.3 years). Peripheral blood DNA was extracted and processed using the Illumina Infinium MethylationEPIC v2.0 BeadChip, which interrogates over 935,000 CpG sites across the genome, including promoters, enhancers, CpG islands, and other regulatory elements. The assay relies on sodium bisulfite conversion of DNA to detect methylation status at single-base resolution. Results: Epigenome-wide association study (EWAS) data allowed for multiple levels of analysis, including immune cell-type deconvolution, estimation of biological age (epigenetic clocks), quantification of stochastic epigenetic mutations (SEMs) as a measure of epigenomic stability, and differential methylation profiling. Immune cell-type inference revealed an increased but not significant proportion of monocytes in PD patients, consistent with previous reports. In contrast, epigenetic clock analysis did not reveal significant differences in biological age acceleration between cases and controls, partially at odds with earlier studies—likely due to the limited sample size. SEMs burden did not differ significantly between groups. Epivariations reveal genes involved in pathways known to be altered in dopaminergic neuron dysfunction and α-synuclein toxicity. Differential methylation analysis, however, yielded 167 CpG sites, of which 55 were located within genes, corresponding to 54 unique loci. Gene Ontology enrichment analysis highlighted significant overrepresentation of pathways with neurological relevance, including regulation of synapse structure and activity, axonogenesis, neuron migration, and synapse organization. Notably, alterations in KIAA0319, a gene involved in neuronal migration, synaptic formation, and cortical development, have previously been associated with Parkinson’s disease at the gene expression level, while methylation changes in FAM50B have been reported in neurotoxic and cognitive contexts; our data suggest, for the first time, a potential epigenetic involvement of both genes in Parkinson’s disease. Conclusions: This pilot study on a Sicilian population provides further evidence that DNA methylation profiling can yield valuable molecular insights into PD. Despite the small sample size, our results confirm previously reported findings and highlight biological pathways relevant to neuronal structure and function that may contribute to disease pathogenesis. These data support the potential of epigenetic profiling of peripheral blood as a tool to advance the understanding of PD and generate hypotheses for future large-scale studies.

Background/Objectives: Huntington’s disease (HD) is an autosomal dominant neurodegenerative disorder caused by a CAG nucleotide repeat expansion in the Huntingtin (HTT) gene. Dysregulation of microRNAs (miRNAs), key post-transcriptional regulators of gene expression, has been implicated in HD pathogenesis, although their specific roles remain incompletely understood. Methods: Peripheral blood mononuclear cells from Sicilian HD patients and matched healthy controls were subjected to small RNA sequencing. Differential expression analysis was conducted using DESeq2 (version 1.44.0), with significance defined as |fold change| ≥ 1.5 and adjusted p ≤ 0.05. Ingenuity Pathway Analysis (IPA) was applied to assess functional enrichment, focusing on neurological diseases, inflammatory processes, and miRNA–RNA messenger (mRNA) interaction networks. Results: A total of 790 differentially expressed miRNAs were identified in HD patients (270 upregulated and 520 downregulated). IPA revealed enrichment in pathways related to organismal injury, neurological disease, and inflammatory responses. Four major regulatory networks linked differentially expressed miRNAs to neurodegenerative processes, with target genes involved in neuroinflammation, cellular stress responses, and metabolic dysfunction. Cross-referencing with previous RNA-seq data identified 5721 high-confidence miRNA–mRNA interactions, implicating 721 target genes across 54 key canonical pathways. Conclusions: HD patients exhibit a distinct and reproducible peripheral blood miRNA expression signature. These dysregulated miRNAs may represent accessible biomarkers and provide mechanistic insights into HD pathogenesis, with potential applications for diagnosis, prognosis, and therapeutic development.

Parkinson’s disease (PD) is a progressive, multisystemic α-synucleinopathy, recognized as the second most prevalent neurodegenerative disorder globally. Its neuropathology is characterized by the degeneration of dopaminergic neurons, particularly in the substantia nigra pars compacta (SNpc), and the intraneuronal accumulation of α-synuclein-forming Lewy bodies. Oxidative stress is a key contributor to PD pathogenesis. Thioredoxin-interacting protein (TXNIP) is a crucial regulator of cellular redox balance, inhibiting the antioxidant function of thioredoxin. This pilot study aimed to investigate the protein expression and localization of TXNIP in the SNpc of PD patients compared to healthy controls. We performed immunohistochemical analyses on 12 post-mortem human brain sections (formalin-fixed, paraffin-embedded) from six subjects with PD and six healthy controls. The study was performed on PD subjects with Braak stage 6. Our findings revealed that in control samples, TXNIP protein was distinctly and closely associated with neuromelanin (NM) pigment within the cytoplasm of SNpc dopaminergic neurons. Conversely, in PD samples, there was a markedly weak cytoplasmic expression of TXNIP, and critically, this association with NM pigment was absent. Furthermore, PD samples exhibited a significant reduction in both dopaminergic neurons and NM content, consistent with advanced disease. These findings, which mirror previous transcriptomic data showing TXNIP gene under-expression in the same subjects, suggest that altered TXNIP expression and localization in SNpc dopaminergic neurons are features of late-stage PD, potentially reflecting neuronal dysfunction and loss.

Background/Objectives: Huntington’s disease (HD) is an autosomal dominant neurodegenerative disorder caused by the expansion of the CAG nucleotide repeat in the first exon of the huntingtin (HTT) gene. The disease typically manifests between the second and third decades of life and progresses gradually. The pathogenesis of HD involves the dysregulation of gene expression, influenced by various molecular processes ranging from transcription to protein stability. Methods: To investigate potential variations in gene expression associated with HD, a transcriptome study was conducted using peripheral blood mononuclear cell samples from 15 HD patients and 15 controls, all of Sicilian origin. Results: The analysis identified 7179 statistically significant differentially expressed genes between the two groups. Gene Set Enrichment Analysis (GSEA) and Gene Ontology (GO) terms were applied to identify the pathways affected by these differentially expressed mRNAs. The GSEA results highlighted significant associations between HD and GO pathways related to ribosomal functions and structure. These pathways were predominantly characterized by negative expression, with a substantial number of genes showing dysregulation. This suggests that the molecular processes leading to protein translation via ribosomes may be impaired in HD. Furthermore, dysregulation was observed in genes and non-coding RNAs involved in regulatory roles across various transcriptional processes. Conclusions: These findings support the hypothesis that the entire process, from transcription to translation, is disrupted in HD patients carrying the CAG repeat expansion in the first exon of the HTT gene.

More than six million people worldwide are affected by Parkinson’s disease (PD), a multifactorial disorder characterized by the progressive loss of dopaminergic neurons in the substantia nigra pars compacta (SNc). Several immunohistochemical studies suggest that neuromelanin (NM), found in these neurons, plays a key role in their degeneration. In this study, twelve formalin-fixed, paraffin-embedded (FFPE) brain sections were analyzed, comprising six samples from PD patients and six from healthy controls. Immunohistochemistry (IHC) was conducted to assess the expression of the ETNPPL protein in these samples. ETNPPL was detected in both PD and control samples. Additionally, we examined the expression of ETNPPL mRNA using Quantitative Real-Time PCR (qRT-PCR) in the same sample set. Notably, in control samples, ETNPPL protein was closely associated with the dark NM pigment in the cytoplasm of SNc dopaminergic neurons. In contrast, PD samples showed weak cytoplasmic expression of ETNPPL, with no association with the NM pigment. No nuclear ETNPPL signal was detected in dopaminergic neurons from either PD patients or controls. qRT-PCR results revealed lower ETNPPL mRNA expression in individual PD patients compared to controls. Importantly, we observed a higher concentration of ETNPPL protein at the NM level in the SNc neurons of controls, consistent with mRNA expression patterns. These findings suggest a potential role for ETNPPL in the normal function of dopaminergic neurons and underscore its altered expression in Parkinson’s disease.

Background/Aim: Bladder cancer (BC) is the most prevalent malignant tumor in the urinary tract, classified mainly into muscle-invasive BC (MIBC) and non-MIBC (NMIBC). Recent studies highlight the important role of changes in transcriptome activity in carcinogenesis, aiding in the identification of additional differentially regulated candidate genes, improving our understanding of the molecular basis of gene regulation in BC. This study aimed to evaluate the transcriptome of MIBC patients compared with normal subjects. Materials and Methods: mRNA sequencing was conducted using the Illumina NovaSeq 6000 Dx system in a case series comprising 11 subjects with MIBC and 19 healthy controls matched for age and sex. For functional analysis, the pathfindR package was utilized to comprehensively identify pathways enriched in omics data within active subnetworks. Results: Our results demonstrated the presence of differentiated pathways, including spliceosome activity, oxidative phosphorylation, and chemical carcinogenesis due to reactive oxygen species, in MIBC patients compared with controls. Conclusion: The identification of novel molecular pathways in MIBC patients could prove useful in defining cancer predisposition factors and exploring potential therapeutic options.

ASD is a complex condition primarily rooted in genetics, although influenced by environmental, prenatal, and perinatal risk factors, ultimately leading to genetic and epigenetic alterations. These mechanisms may manifest as inflammatory, oxidative stress, hypoxic, or ischemic damage. To elucidate potential variances in gene expression in ASD, a transcriptome analysis of peripheral blood mononuclear cells was conducted via RNA-seq on 12 ASD patients and 13 healthy controls, all of Sicilian ancestry to minimize environmental confounds. A total of 733 different statistically significant genes were identified between the two cohorts. Gene Set Enrichment Analysis (GSEA) and Gene Ontology (GO) terms were employed to explore the pathways influenced by differentially expressed mRNAs. GSEA revealed GO pathways strongly associated with ASD, namely the GO Biological Process term “Response to Oxygen-Containing Compound”. Additionally, the GO Cellular Component pathway “Mitochondrion” stood out among other pathways, with differentially expressed genes predominantly affiliated with this specific pathway, implicating the involvement of different mitochondrial functions in ASD. Among the differentially expressed genes, FPR2 was particularly highlighted, belonging to three GO pathways. FPR2 can modulate pro-inflammatory responses, with its intracellular cascades triggering the activation of several kinases, thus suggesting its potential utility as a biomarker of pro-inflammatory processes in ASD.

Parkinson’s disease (PD) stands as the most prevalent degenerative movement disorder, marked by the degeneration of dopaminergic neurons in the substantia nigra of the midbrain. In this study, we conducted a transcriptome analysis utilizing post mortem mRNA extracted from the substantia nigra of both PD patients and healthy control (CTRL) individuals. Specifically, we acquired eight samples from individuals with PD and six samples from CTRL individuals, with no discernible pathology detected in the latter group. RNA sequencing was conducted using the TapeStation 4200 system from Agilent Technologies. A total of 16,148 transcripts were identified, with 92 mRNAs displaying differential expression between the PD and control groups. Specifically, 33 mRNAs were significantly up-regulated, while 59 mRNAs were down-regulated in PD compared to the controls. The identification of statistically significant signaling pathways, with an adjusted p-value threshold of 0.05, unveiled noteworthy insights. Specifically, the enriched categories included cardiac muscle contraction (involving genes such as ATPase Na⁺/K⁺ transporting subunit beta 2 (ATP1B2), solute carrier family 8 member A1 (SLC8A1), and cytochrome c oxidase subunit II (COX2)), GABAergic synapse (involving GABA type A receptor-associated protein-like 1 (GABARAPL1), G protein subunit beta 5 (GNB5), and solute carrier family 38 member 2 (SLC38A2), autophagy (involving GABARAPL1 and tumor protein p53-inducible nuclear protein 2 (TP53INP2)), and Fc gamma receptor (FcγR) mediated phagocytosis (involving amphiphysin (AMPH)). These findings uncover new pathophysiological dimensions underlying PD, implicating genes associated with heart muscle contraction. This knowledge enhances diagnostic accuracy and contributes to the advancement of targeted therapies.