miRNATissueAtlas 2025: an update to the uniformly processed and annotated human and mouse non-coding RNA tissue atlas

Wide-spectrum profiling of plasma cell-free RNA and the potential for health-monitoring

Circulating cell-free RNA (cfRNA) has emerged as a promising analyte for disease detection. However, the comprehensive profiling of diverse cfRNA types remains under-characterized. Here, we applied a new wide-spectrum cfRNA sequencing method and simultaneously captured rRNA, tRNA, mRNA, miRNA, lncRNA and all mitochondrial RNA. The cfRNA compositions, size distributions and highly abundant cfRNA genes were analysed for each type of cfRNA. We depicted the cfRNA cell types of origin profiles of 66 generally healthy individuals and found that BMI showed a significant impact on the kidney-derived cfRNA proportion. Three individuals with some liver problems were identified because of relatively high levels of hepatocyte-specific cfRNA. The abundance levels of different genes and RNA types, including mRNA, miRNA and lncRNA, were significantly correlated with the liver function test results. The genes of individual cfRNA variances were enriched in pathways associated with common diseases such as liver diseases, virus infections, cancers and metabolic diseases. This study provided a profiling of cfRNA and displayed the potential of cfRNA as a biomarker in health monitoring.

Crosstalk Between Dietary Fatty Acids and MicroRNAs in the Regulation of Hepatic ApoB-Containing Lipoprotein Synthesis in Humans

Enhanced hepatic synthesis, assembly, and secretion of apolipoprotein B (ApoB)-containing lipoproteins elevate their plasma levels and-like their impaired clearance from the circulation-can increase cardiovascular risk. Both dietary fatty acids and microRNAs contribute to the nutrient-dependent regulation of hepatic gene expression. Together, these factors may modulate lipid and ApoB-containing lipoprotein synthesis in the liver, either exacerbating or mitigating dyslipidemia. Research continues to reveal the complexity of fatty acid-microRNA networks and highlights differences in regulating hepatic ApoB-containing lipoprotein synthesis between humans and rodents. Consequently, this review focuses on studies conducted in humans or human-derived hepatocytes.

Loss of miRNA-Mediated VEGFA Regulation by SNP-Induced Impairment: A Bioinformatic Analysis in Diabetic Complications

Background/Objectives: MicroRNAs (miRNAs) are molecules involved in biological regulation processes, including type 2 diabetes and its complications development. Single nucleotide polymorphisms (SNPs) can alter miRNA mechanisms, resulting in loss or gain effects. VEGFA is recognized for its role in angiogenesis. However, its overexpression can lead to deleterious effects, such as disorganized and inefficient vasculature. Under hyperglycemic conditions, VEGFA expression seems to increase, which may contribute to the development of microvascular and macrovascular diabetic complications. Several miRNAs are associated with VEGFA regulation and seem to act in the prevention of dysregulated expression. This study aimed to investigate SNPs in miRNA regions related to the loss effect in VEGFA regulation, examining their frequency and potential physiological effects in the development of diabetic complications. Methods: VEGFA-targeting miRNAs were identified using the R package multimiR, with validated and predicted results. Tissue expression analysis and SNP search were data-mined with Python 3 for miRNASNP-v3 SNP raw databases. Allele frequencies were obtained from dbSNP. The miRNA-mRNA interaction comparison was obtained in the miRmap tool through Python 3. MalaCards were used to infer physiological disease association. Results: The variant rs371699284 was selected in hsa-miR-654-3p among 103 potential VEGFA-targeting miRNAs. This selected SNP demonstrated promising results in bioinformatics predictions, tissue-specific expression, and population frequency, highlighting its potential role in miRNA regulation and the resulting loss in VEGFA-silencing efficiency. Conclusions: Our findings suggest that carriers of rs1238947970 may increase susceptibility to diabetic microvascular and macrovascular complications. Furthermore, in vitro and in silico studies are necessary to better understand these processes.

MicroRNA-138-5p suppresses excitatory synaptic strength at the cerebellar input layer

MicroRNAs are small, highly conserved non-coding RNAs that negatively regulate mRNA translation and stability. In the brain, miRNAs contribute to neuronal development, synaptogenesis, and synaptic plasticity. MicroRNA 138-5p (miR-138-5p) controls inhibitory synaptic transmission in the hippocampus and is highly expressed in cerebellar excitatory neurons. However, its specific role in cerebellar synaptic transmission remains unknown. Here, we investigated excitatory transmission in the cerebellum of mice expressing a sponge construct that sequesters endogenous miR-138-5p. Mossy fibre stimulation-evoked EPSCs in granule cells were ∼40% larger in miR-138-5p sponge mice compared to controls. Furthermore, we observed larger miniature EPSC amplitudes, suggesting an increased number of functional postsynaptic AMPA receptors. High-frequency train stimulation revealed enhanced short-term depression following miR-138-5p downregulation. Together with computational modelling, this suggests a negative regulation of presynaptic release probability. Overall, our results demonstrate that miR-138-5p suppresses synaptic strength through pre- and postsynaptic mechanisms, providing a potentially powerful mechanism for tuning excitatory synaptic input into the cerebellum. KEY POINTS: MicroRNAs are powerful regulators of mRNA translation and control key cell biological processes including synaptic transmission, but their role in regulating synaptic function in the cerebellum has remained elusive. In this study, we investigated how microRNA-138-5p (miR-138-5p) modulates excitatory transmission at adult murine cerebellar mossy fibre to granule cell synapses. Downregulation of miR-138-5p enhances excitatory synaptic strength at the cerebellar input layer and increases short-term depression. miR-138-5p exerts its regulatory function through both pre- and postsynaptic mechanisms by negatively regulating release probability at mossy fibre boutons, as well as functional AMPA receptor numbers in granule cells. These findings provide insights into the role of miR-138-5p in the cerebellum and expand our understanding of microRNA-dependent control of excitatory synaptic transmission and short-term plasticity.

The miRNomics of antiretroviral therapy-induced obesity

Human immunodeficiency virus (HIV) is a retrovirus that incorporates its genetic material into the host's chromosome. The resulting diseases and related conditions constitute a global health problem as there are no treatments to eliminate HIV from an infected individual. However, the potent, complex, and active antiretroviral therapy (ART) strategies have been able to successfully inhibit HIV replication in patients. Unfortunately, obesity following ART is frequent among HIV-infected patients. The mechanism underlying ART-induced obesity is characterized based on expression of traditional markers such as genes and proteins. However, little is known about, yet another key component of molecular biology known as microRNAs (miRNAs). Micro-RNAs are ~ 22 base-long non-coding nucleotides capable of regulating more than 60% of all human protein-coding genes. The interest in miRNA molecules is increasing and their roles in HIV and obesity are beginning to be apparent. In this review, we provide an overview of HIV and its associated diseases, ART-induced obesity, and discuss the roles and plausible benefits of miRNAs in regulating obesity genes in HIV-infected patients. Understanding the roles of miRNAs in ART-induced obesity will aid in tracking the disease progression and designing beneficial therapeutic approaches.

Cannabinerol Restores mRNA Splicing Defects Induced by β-Amyloid in an In Vitro Model of Alzheimer's Disease: A Transcriptomic Study

Alzheimer's disease (AD) is the most common form of dementia, characterized by β-amyloid (Aβ) plaques and neurofibrillary tangles, leading to neuronal loss and cognitive impairments. Recent studies have reported the dysregulation of RNA splicing in AD pathogenesis. Our previous transcriptomic study demonstrated the neuroprotective effect of the phytocannabinoid cannabinerol (CBNR) against the cell viability loss induced by Aβ in differentiated SH-SY5Y cells. This study also highlighted the deregulation of genes involved in mRNA splicing after Aβ exposure or CBNR pre-treatment. Here, we investigated whether CBNR could restore the splicing defects induced by Aβ in an AD in vitro model. Using the rMATS computational tool for detecting differential alternative splicing events (DASEs) from RNA-Seq data, we obtained 96 DASEs regulated in both conditions and, remarkably, they were all restored by CBNR pre-treatment. The pathway analysis indicated an over-representation of the "Alzheimer's disease-amyloid secretase pathway". Additionally, we observed that Aβ exposure increased the frequency of retained introns (RIs) among the shared DASEs, and that this frequency returned to normality by CBNR pre-treatment. Interestingly, most of these RIs contain a premature in-frame stop codon within the RNA sequence. Finally, analyzing the DASE regions for miRNA hybridization, we found 33 potential DASE/miRNA interactions that were relevant in AD pathogenesis. These findings revealed a novel trans-gene regulation by CBNR, potentially explaining part of its neuroprotective role. This is the first study demonstrating the involvement of a cannabinoid in the regulation of mRNA splicing in an AD model.

Flipons enable genomes to learn by intermediating the exchange of energy for information

Recent findings have confirmed the long-held belief that alternative DNA conformations encoded by genetic elements called flipons have important biological roles. Many of these alternative structures are formed by sequences originally spread throughout the human genome by endogenous retroelements (ERE) that captured 50% of the territory before being disarmed. Only 2.6% of the remaining DNA codes for proteins. Other organisms have instead streamlined their genomes by eliminating invasive retroelements and other repeat elements. The question arises, why retain any ERE at all? A new synthesis suggests that flipons enable genomes to learn and programme the context-specific readout of information by altering the transcripts produced. The exchange of energy for information is mediated through changes in DNA topology. Here I provide a formulation for how genomes learn and describe the underlying p-bit algorithm through which flipons are tuned. The framework suggests new strategies for the therapeutic reprogramming of cells.

The 2025 Nucleic Acids Research database issue and the online molecular biology database collection

The 2025 Nucleic Acids Research database issue contains 185 papers spanning biology and related areas. Seventy three new databases are covered, while resources previously described in the issue account for 101 update articles. Databases most recently published elsewhere account for a further 11 papers. Nucleic acid databases include EXPRESSO for multi-omics of 3D genome structure (this issue's chosen Breakthrough Resource and Article) and NAIRDB for Fourier transform infrared data. New protein databases include structure predictions for human isoforms at ASpdb and for viral proteins at BFVD. UniProt, Pfam and InterPro have all provided updates: metabolism and signalling are covered by new descriptions of STRING, KEGG and CAZy, while updated microbe-oriented databases include Enterobase, VFDB and PHI-base. Biomedical research is supported, among others, by ClinVar, PubChem and DrugMAP. Genomics-related resources include Ensembl, UCSC Genome Browser and dbSNP. New plant databases cover the Solanaceae (SolR) and Asteraceae (AMIR) families while an update from NCBI Taxonomy also features. The Database Issue is freely available on the Nucleic Acids Research website (https://academic.oup.com/nar). At the NAR online Molecular Biology Database Collection (http://www.oxfordjournals.org/nar/database/c/), 932 entries have been reviewed in the last year, 74 new resources added and 226 discontinued URLs eliminated bringing the current total to 2236 databases.