Tavares, G. A. | Search bioRxiv

bioRxiv2026

Lymphatic CD49a is a driver of meningeal immune aging and cognitive decline.

Aging is associated with progressive accumulation and dysregulation of dural immune cells, coinciding with impaired CSF drainage and lymphatic function. Prior work has shown that improving lymphatic function in aged mice is sufficient to ameliorate age-associated cognitive decline, and that local immune cells can directly regulate lymphatic draining function. Yet, the endothelial-intrinsic mechanisms driving lymphatic dysfunction remain unclear. Here we found that the integrin CD49a is upregulated in aged lymphatic endothelial cells and regulates CCL21 release. Accordingly, genetic deletion of CD49a in lymphatic endothelial cells broadly reverses age-associated immune dysfunction across dural myeloid, lymphoid and dendritic cell compartments, limits glial aging, and mitigates cognitive and social behavioral deficits, thereby revealing a targetable endothelial-intrinsic mechanism of lymphatic aging.

neuroscience↗

bioRxiv2026

A Single-Cell Atlas of the Mouse Dural Meninges Reveals Pervasive Sex Differences Across Cellular Compartments

The dural compartment of the meninges forms a dynamic interface between the brain and the periphery, hosting diverse immune, vascular, mural and fibroblast populations. Single-cell studies have begun charting meningeal cellular diversity, yet a comprehensive view encompassing all major cellular compartments, intercellular communication, and the influence of sex remains lacking. Here, we present a single-cell transcriptomic atlas of the adult mouse dural meninges, profiling all major cell types in male and female mice at steady state. We uncover broad sex differences in cell-type-specific proportion, transcriptional programs, intercellular communication, and disease relevant signatures. Histological and cytometry analyses validate the biological relevance of these findings, establishing this atlas as a foundation for studying meningeal contributions to neurological disease in a sex-aware manner.

neuroscience↗

bioRxiv2022

Epigenetic alterations in gut and brain of adult rats after oral administration of miR-320-3p and miR-375-3p at mid-lactation, and preventive potential of miR-320-3p on early weaning stress.

AimTo investigate if the artificial delivery of microRNAs naturally present in the breastmilk can impact the gut and brain of young rats according to weaning. MethodsAnimals from a new transgenic rat line expressing green-fluorescent protein in the endocrine lineage (cholecystokinin expressing cells) received at Day-12, near neural diversification, a single oral bolus of mir-320-3p or miR-375-3p, embedded in DiOleyl-Succinyl-Paromomycin (DOSP), and were further early (Day-15) or regularly (Day-30) weaned. Relevant miRNA (miR-320-3p, miR-375-3p, miR-375-5p, miR-16-5p, miR-132-3p, miR-504), polr3d, hspb6, inflammation, enteroendocrine, and circadian clock-related mRNAs, chromatin complexes, and duodenal cell density were assayed at 8h post-inoculation and at Day-45. ResultsThe miR-320-3p/DOSP induced immediate effects on H3K4me3 chromatin complexes with polr3d promoter (p<0.05) but no long-term effects. On regular weaning, at Day-45, both miR-320-3p and 375-3p were down-regulated in the stomach, up-regulated in the hypothalamus (p<0.001) but only miR-320-3p was up-regulated in the duodenum. After early weaning, the miR-320-3p and miR-375-3p levels were down-regulated in the stomach and the duodenum, but up-regulated in the hypothalamus and the hippocampus. Combining miR-320-3p/DOSP with early weaning enhanced miR-320-3p and chromogranin A expression in the duodenum. In the hippocampus, the miR-504 was down-regulated for both sexes, but in the brain stem, up regulated only for females, along with miR-320-3p and miR-16-5p levels. In the hypothalamus, clock levels were up regulated for both sexes. In the miR-375-3p/DOSP group, the density of enteroendocrine duodenal cells increased. The long-term effect of miR-375-3p/DOSP was more limited, according to the fourfold lower number of predicted targets than with miR-320-3p. ConclusionAddressing oral miRNA-320-3p loads to duodenal cell lineage is paving the way for the design of new therapeutics, manipulating long term consequences of early life stress.

genetics↗