Extracellular vesicles (EVs) and their miRNA cargo are intercellular communicators transmitting their pleiotropic messages between different cell types, tissues, and body fluids. Recently, they have been reported to contribute to skin homeostasis and were identified as members of the senescence-associated secretory phenotype of human dermal fibroblasts. However, the role of EV-miRNAs in paracrine signaling during skin aging is yet unclear. Here we provide evidence for the existence of small EVs in the human skin and dermal interstitial fluid using dermal open flow microperfusion and show that EVs and miRNAs are transferred from dermal fibroblasts to epidermal keratinocytes in 2D cell culture and in human skin equivalents. We further show that the transient presence of senescent fibroblast derived small EVs accelerates scratch closure of epidermal keratinocytes, whereas long-term incubation impairs keratinocyte differentiation in vitro. Finally, we identify vesicular miR-23a-3p, highly secreted by senescent fibroblasts, as one contributor of the EV-mediated effect on keratinocytes in in vitro wound healing assays. To summarize, our findings support the current view that EVs and their miRNA cargo are members of the senescence-associated secretory phenotype and, thus, regulators of human skin homeostasis during aging.

Cereal crops, including wheat and barley, are essential for global food security, but their productivity is strongly affected by nitrogen availability and water limitation. This study investigated the phenotypic responses of two commercially significant spring wheat cultivars, Videodur (DU) and Sensas (SW), and two spring barley cultivars, Tiroler Imperial (SG1) and Amidala (SG2), exposed to two nitrogen regimes, low nitrogen at 25 kg N/ha (N25) and high nitrogen at 130 kg N/ha (N130), under drought and well-watered conditions. Plants were monitored from the late vegetative stage through maturity under controlled multivariable climatic conditions similar to field settings. A high-throughput phenotyping workflow was applied, combining precision watering, RGB imaging, infrared thermography, and VNIR–SWIR hyperspectral imaging to quantify plant growth, projected digital biomass, plant temperature, water use efficiency, and spectral vegetation indices associated with pigment dynamics, water status, maturation, and senescence. The results revealed cultivar-specific responses to combined nitrogen and drought stress. Under drought conditions, the high nitrogen treatment (N130) increased plant temperature (Tplant) for barley (cv. SG1) and wheat (cv. SW) compared to N25, thereby accelerating early maturation. However, the decline in chlorophyll was not uniformly faster across all cultivars tested. The DU cultivar exhibited superior chlorophyll absorption and reflectance, indicating better drought adaptation compared to other tested species. The high nitrogen treatment (N130) reduced water use efficiency (WUE) in the SW and SG2 cultivars compared to N25, implying that these cultivars used more water. Enhanced nitrogen did not consistently improve water use efficiency but did accelerate the growth cycle. SG2 was particularly sensitive to drought, showing declines in vegetation indices, except for the Water Content Index, highlighting the need for precise water and nitrogen management. Overall, the integration of hyperspectral, thermal, RGB, and water use measurements enabled the identification of trait signatures linked to drought adaptation, nitrogen response, maturation, and senescence. These findings provide practical insights for optimizing nitrogen and irrigation management and for supporting breeding strategies aimed at improving cereal crop resilience under climate-change-associated stress conditions.