Early diagnosis of Alzheimer’s disease (AD) and the identification of reliable molecular biomarkers remain critical clinical needs. In this context, extracellular vesicles (EVs) enriched by L1CAM immunocapture—L1CAM-enriched EVs—a fraction widely used to obtain material of putative neuronal origin, have been proposed as a minimally invasive source of information on brain molecular changes. We conducted next-generation sequencing (NGS) of microRNAs (miRNAs) from L1CAM-enriched EVs isolated from the plasma of 11 AD patients, 11 mild cognitive impairment (MCI) individuals, and 14 healthy controls (CTRs) to identify a candidate molecular signature. Our analysis identified five differentially expressed miRNAs—miR-423-5p, miR-122-5p, miR-151b, miR-16-5p, and miR-149-3p—in MCI individuals. Three of these—miR-423-5p, miR-122-5p and miR-151b—were higher in MCI and lower in AD, a pattern that differentiated the two clinically defined groups. Furthermore, enrichment analysis of the predicted targets of the differentially expressed miRNAs identified processes relevant to neurodegeneration, including synaptic organisation, cytoskeletal dynamics, and protein degradation. Overall, these preliminary findings identify blood-based L1CAM-enriched EV miRNAs as candidates for further evaluation in cognitive impairment. While validation in larger, biomarker-confirmed and independent cohorts is required, this exploratory study provides data that may guide the design of future biomarker studies.

Host microRNAs (miRNAs) are widely proposed as innate antiviral effectors against SARS-CoV-2, yet whether they actually restrict infection in lung epithelial cells remains unresolved. Two of the most-cited candidates, miR-29a-3p and miR-15b-5p, are predicted to bind both the viral genome and key entry/trafficking factors such as Furin and ATG9A, but functional evidence is fragmented and often contradictory. Here, we put both miRNAs to the test in human Calu-3 cells infected with the SARS-CoV-2 Beta and Omicron BA.1 variants, using parallel gain- and loss-of-function strategies coupled to RT-qPCR of viral and cellular transcripts and back-titration of infectious progeny on VeroE6/TMPRSS2 cells. Both miRNAs transiently suppressed viral gene expression at 6 hpi, but this early dampening was followed by a marked transcript rebound at 24 hpi, especially for Omicron, with virtually no impact on total extracellular viral RNA. More strikingly, miR-15b modulation enhanced infectious virus output during Beta infection, and miR-29a overexpression boosted Omicron BA.1 infectivity, while Furin, ATG9A, AKT3, and TFEB showed only modest, condition-dependent shifts. Rather than acting as clean antiviral effectors, miR-29a and miR-15b emerge as context-dependent modulators that can paradoxically favor SARS-CoV-2 replication—a cautionary signal for miRNA-based antiviral strategies.

Background: Familial prostate cancer (PCa) accounts for nearly 20% of all PCa cases and is associated with increased genetic susceptibility and earlier disease onset. However, early detection and risk stratification in genetically predisposed individuals remain challenging. Circulating cell-free DNA (cfDNA) provides a minimally invasive source of tumor-derived genomic and epigenomic information. Integrating multi-omic cfDNA analyses may enhance the discovery of biomarkers relevant to familial PCa biology. Methods: We conducted a pilot feasibility study employing whole-genome, strand-specific sequencing of cfDNA from eight patients with familial PCa. A unified analytical pipeline was used to jointly profile genomic alterations and epigenomic features. Variant calling, methylation mapping, and allele-specific methylation (ASM) analysis were performed to identify somatic mutations, characterize epigenetic dysregulation, and explore potential interactions between genetic and epigenetic mechanisms. Results: Sequencing revealed 18,878 genetic variants, including 2276 potentially pathogenic alterations. We identified 26 recurrent high-impact mutations, such as stop-gain and start-loss variants, in genes including MUC4, MCM9, and SKA3. Epigenomic profiling demonstrated widespread gene-specific hypermethylation, consistent with transcriptional repression in these loci. ASM events were detected in TTC22, TEX51, WDR89, LAIR2, and SKA3, suggesting coordinated interactions between somatic variation and epigenetic regulation in familial PCa. Conclusions: This proof-of-concept study highlights the feasibility and potential of integrating whole-genome and epigenome profiling of cfDNA to decode the molecular architecture of familial prostate cancer. By jointly capturing genomic alterations and epigenetic signatures, including allele-specific methylation, this multi-omic liquid biopsy approach supports a high-resolution exploration of biologically relevant molecular features. Moreover, this integrated profiling strategy provides a minimally invasive and clinically scalable tool that may substantially improve risk assessment. These findings offer a promising foundation for future validation studies in larger cohorts, with the aim of advancing multi-omic cfDNA analysis as a next-generation technology in the field of precision oncologic epigenetics.