Functional long non-coding RNAs (lncRNAs) have been in the limelight in aging research because short telomeres are associated with higher levels of TERRA (Telomeric Repeat containing RNA). The genomic instability, which leads to short telomeres, is a mechanism observed in cell aging and in a class of cancer cells. Psoriasis, a skin disease, is a disorder of epidermal keratinocytes, with altered telomerase activity. Research on the fraction of nascent RNAs in hybrid with DNA offers avenues for new strategies. Skin and blood samples from patients were fractionated to obtain the RNA associated with DNA as a R-loop structure. The higher amount of TERRA levels attached with each chromosome end was found with psoriasis patients in blood and skin. In addition to telomeric TERRA, we evidenced accumulation of others non-coding RNA, such as non-telomeric TERRA and centromeric transcripts. Increased levels of non-coding RNAs attached to DNA correlates with a decreased in Ribonuclease HII (RNase-HII) transcript which means that overall unresolved DNA–RNA hybrids can ultimately weaken DNA and cause skin lesions. Since the genome is actively transcribed, cellular RNase-HII is essential for removing RNA from the DNA–RNA hybrid in controls of genome stability and epigenome shaping and can be used as a causal prognostic marker in patients with psoriasis.

Local three-stranded DNA/RNA hybrid regions of genomes (R-loops) have been detected either by binding of a monoclonal antibody (DRIP assay) or by enzymatic recognition by RNaseH. Such a structure has been postulated for mouse and human telomeres, clearly suggested by the identification of the complementary RNA Telomeric repeat-containing RNA “TERRA”. However, the tremendous disparity in the information obtained with antibody-based technology drove us to investigate a new strategy. Based on the observation that DNA/RNA hybrids in a triplex complex genome co-purify with the double-stranded chromosomal DNA fraction, we developed a direct preparative approach from total protein-free cellular extract without antibody that allows their physical isolation and determination of their RNA nucleotide sequence. We then define in the normal mouse and human sperm genomes the notion of stable DNA associated RNA terminal R-loop complexes, including TERRA molecules synthesized from local promoters of every chromosome. Furthermore, the first strong evidence of all telomeric structures, applied additionally to the whole murine sperm genome compared to the testes, showed reproducible R-loop complexes of the whole genome and suggesting a defined profile in the sperm genome for the next generation.

Mature spermatozoa contain a whole repertoire of the various classes of cellular RNAs, both coding and non-coding. It was hypothesized that after fertilization they might impact development, a claim supported by experimental evidence in various systems. Despite the current increasing interest in the transgenerational maintenance of epigenetic traits and their possible determination by RNAs, little remains known about conservation in sperm and across generations and the specificities and mechanisms involved in transgenerational maintenance. We identified two distinct fractions of RNAs in mature mouse sperm, one readily extracted in the aqueous phase of the classical TRIzol procedure and a distinct fraction hybridized with homologous DNA in DNA-RNA complexes recovered from the interface, purified after DNase hydrolysis and analyzed by RNA-seq methodology. This DNA-associated RNA (D RNA) was found to represent as much as half of the cell contents in differentiated sperm, in which a major part of the cytoplasmic material has been discarded. Stable complexes were purified free of proteins and identified as hybrids (R-loops) on the basis of their sensitivity to RNase H hydrolysis. Further analysis by RNA-seq identified transcripts from all the coding and non-coding regions of the genome, thus revealing an extensive wave of transcription, prior to or concomitant with the terminal compaction of the chromatin.

A wide range of diseases result from environmental effects, and the levels of many native transcripts are altered. The alteration of non-coding RNAs (ncRNAs) and transmission of the variation to the next generation is increasingly recognized as a marker of disease. However, the determining signals and mechanisms of RNA-induced heritability remain unclear. We performed functional tests with four different genotypes of mice maintained on a high-fat diet to trace the transfer of the obesity/diabetes phenotype to the next generation in order to detect common signals. Two founders of four mouse lines (B6/D2 hybrid and Dnmt2^{−/−C57BL/6}) resist and do not change their phenotype while their sperm RNAs after microinjection into fertilized mouse eggs transfer the newly acquired phenotypes in a susceptible inbred line (C57BL/6 or Balb/c). Unexpectedly, in the same line of experiments, sperm RNA from animals raised on a normal diet when mixed with the sperm RNA from animals raised on a diet high in fat or synthetic miR-19b (inducer of obesity) affects or prevents the development of obesity and diabetes. However, it remains unclear what happens to ncRNA signaling under diet. With a comprehensive new analysis of the transcripts maintained as an RNA/DNA hybrid in sperm, we suggest that a fraction of the RNAs are stably attached to the genome. Thus, we propose that changes in the dynamics of ncRNA retention on DNA by factors such as transcriptional variations or lack of adequate methylation could serve as molecular markers to trace these epigenetics events.

Autosomal dominant polycystic kidney disease (ADPKD) is a most common hereditary kidney disorder and a major contributor to end-stage kidney disease (ESKD), but its molecular progression mechanisms are unclear. We performed metabolomic and transcriptomic profiling on a longitudinal cohort of 254 and 47 ADPKD patients, respectively, to identify molecular alterations and then applied Multi-Omics Factor Analysis (MOFA) to uncover coordinated signatures. Disease progression was associated with a marked shift in dysregulated lipids profile, increased acylcarnitines, and increased glycolytic metabolites, suggesting a shift from fatty acid oxidation (FAO) toward glycolysis. Transcriptomic analysis revealed enrichment of PPAR signaling, cytoskeletal remodeling, and cystogenesis, providing a mechanistic link between metabolic alterations and structural dysregulation. Integrative analysis identified a central axis where inflammation, metabolic reprogramming, and cytoskeletal remodeling converges. Our integrated multi-omics analysis defines a molecular framework where transcriptomic dysregulation drives metabolic reprogramming contribute to cystogenesis, providing potential biomarkers and insights to guide precision therapy in ADPKD progression.

Autism spectrum disorder (ASD) is a set of genetically heterogenous neurodevelopmental disorders characterized by core symptoms including impaired social interaction, communication deficits, and restricted or stereotyped behaviors. While a significant number of cases are not explained by Mendelian inheritance, there is growing evidence for implication of non-coding RNAs (ncRNAs) in the development and inheritance of ASD. Transcriptional studies often face challenges due to patient-specific variations in gene expression and technical differences in preserving RNA integrity. We propose that isolating RNA from DNA/RNA hybrids provides a robust method to reliably capture transcriptional information. We performed a whole transcriptome analysis on blood samples from ASD patients and healthy controls to investigate transcripts associated with DNA/RNA hybrids. We identified 278,300 novel transcripts across 68,487 DNA/RNA hybrid loci, with significant enrichment in exonic and intronic regions. The novel long non-coding RNAs (lncRNAs) we found showed higher expression levels compared to known transcripts. Differential expression analysis revealed 301 significantly upregulated and 401 downregulated known transcripts in ASD samples compared to controls (|log ₂ -fold change| > 1 and adjusted p-value < 0.05). Through qRT-PCR validation, we confirmed the significant upregulation of RN7SK and SMARCC2 associated with DNA/RNA hybrids in ASD patients. Pathway and enrichment analyses highlighted mitochondrial dysfunction and energy metabolism. Our results suggest that ncRNAs can form DNA/RNA hybrids that influence gene expression, providing preliminary insights into the mechanisms of transcriptional dysregulation in ASD.