Rheinheimer, S. | bioRxiv Science

bioRxiv2026

Aging Rhesus Macaque show tissue and sex-specific balance of drifting and coordinated miRNA programs

Macaques research centrality makes it critical to study their molecular aging. We accomplish this for their non-coding transcriptome by sequencing small RNA from 11 organs, with special focus on brain by including 24 brain regions, sampling males and females between ages 3-35 years. Heart, adrenal gland, corpus callosum and caudate putamen showed the most age-deregulated miRNA trajectories. The MIR-154 family, inside the imprinted, rejuvenation-associated Dlk1-Dio3 cluster, was particularly vulnerable. Known age-associated miRNA families LET-7, MIR-29, MIR-17 and MIR-92 were strongly deregulated, with heavy dependence on tissue and sex. MiRNA genomic clusters deregulation was concordant within tissue-sex combinations, implicating upstream regulation rather than random noise. Cross-species comparison with mouse showed ancient miRNAs dominating age-deregulated trajectories. Deregulation direction in tissues-sex was conserved between species at family/cluster levels, but conservation substantially weakened at individual miRNA level. Thus, we mark a decisive step in translating miRNA aging trajectories between two heavily used model organisms. Key FindingsO_LIHeart, adrenal gland, corpus callosum, caudate putamen are hotspots of miRNA age deregulation, with dramatic influence from sex. C_LIO_LINon-brain organs show tissue specific miRNA change, with inconsistent overlap between tissues. C_LIO_LIGenomic clusters of miRNAs were found to be concordant in their age deregulation direction, dependent on tissue and sex, suggesting upstream regulation. C_LIO_LIThe MIR-154 family, housed inside the heavily imprinted Dlk1-Dio3 cluster and processed from the rejuvenation associated MEG3-MIRG host gene is prominently involved in both non-brain organs and brain regions. C_LIO_LIConcentration of age deregulation in evolutionarily ancient miRNAs across species implies regulatory program rather than epigenetic drift, involving MIR-154, LET-7, MIR-29, MIR-17 and MIR-92 families. C_LIO_LIDirection of change conserved between species at the family / genomic cluster level but diminished substantially at individual miRNA level. C_LI

systems biology↗

bioRxiv2025

Extracellular vesicles and their RNA cargo facilitate bidirectional cross-kingdom communication between human and bacterial cells

While extracellular vesicles (EVs) are established mediators of intra-species signaling, their role as active participants in cross-kingdom communication remains incompletely understood. Here, we reveal that human colon cells and both Gram-positive and Gram-negative gut bacteria engage in species-specific, EV-mediated molecular dialogue, driven in part by RNA cargo. We show that bacterial EVs (BEVs) induce distinct transcriptomic responses in human cells, and that BEV-RNA independently causes similar effects. Conversely, we demonstrate that human EVs and highly abundant miR-192-5p are differentially internalized by bacteria, affecting their physiology. Our findings support a conceptual model in which EVs function as directional messengers that shape host-microbiome interactions. This study introduces a framework for understanding EVs as cross-kingdom regulators and underscores the importance of tailored, context-specific analyses for understanding the scope of EV-mediated interactions in microbiome-host homeostasis and disease. Highlights[1] L. casei, E. faecalis and P. mirabilis produce BEVs that are internalized by Caco-2 cells at different rates. BEVs produced by L. casei have a positive influence on the viability of Caco-2 cells. Incubation of Caco-2 cells with BEVs leads to changes in the gene expression of immune-response-related genes. [2] BEVs carry RNAs and the type of RNA cargo varies significantly between the BEVs from the different bacteria. Comparison of Caco-2 gene deregulation between BEVs and transfection of RNA isolated from BEV highlights component-specific effects. [3] Caco-2 EVs are taken up by E. faecalis and influence their growth. MiRNA-192-5p can be frequently detected in EVs from Caco-2 cells. Synthetic miR-192-5p is internalized by P. mirabilis and the ability to take up human miRNAs by L. casei and E. faecalis can be increased by packaging of the miRNA in artificial liposomes.

molecular biology↗