Biology subjects

Nesic, S.

Publications and source records attributed to Nesic, S..

3 recordsLinked to original sources

bioRxiv2025

Outer Membrane Vesicles (OMVs) Produced by Plant Beneficial Rhizospheric Bacteria Enter Root Epidermal Cells

Extracellular vesicles (EVs) are shown to play an important role in the interaction between bacteria and human cells, as well as between fungi and plants; however, much less is known about their role in plant-bacteria relations. Outer membrane vesicles (OMVs), EVs produced by Gram-negative bacteria, were shown to have both immuno-activating and immuno-suppressive effects on plants, and a direct interaction of OMVs with plant cell membranes was shown for one phytopathogenic bacterial strain. Data on OMVs participation in the symbiotic relationship between plant-beneficial bacteria and plants are even more limited, and are mainly related to the rhizobia-legume interaction. To investigate the interaction of OMVs of non-rhizobial phytobeneficial bacteria with plant cells, we isolated and characterized OMVs produced by Paraburkholderia phytofirmans PsJN, a strain well known for its growth-promoting and stress-protective effects in a wide range of plant species. Using OMVs labelled with fluorescent lipid-binding dye VybrantTM DiD and confocal laser scanning microscopy, we showed that PsJN-OMVs interact directly with the root hairs and epidermal cells of Arabidopsis thaliana and tomato. Moreover, by employing octadecyl-rhodamine B chloride (R18), we demonstrated that PsJN-OMVs can fuse with plant cell membranes. The findings presented in our study are an important step in elucidating the potential role of OMVs in the early stages of root colonization and the establishment of symbiotic relationships. Increasing our understanding in this area could pave the way for the use of these nano-vehicles to develop eco-friendly solutions for overcoming environmental challenges and supporting sustainable agriculture.

plant biology↗

bioRxiv2025

miR-196a-5p and miR-342-3p mediate skeletal muscle and thermogenic adipose tissue crosstalk through extracellular vesicles

Small extracellular vesicles (small EVs) are nanovesicles found in tissues and body fluids that contain regulatory molecules including microRNAs, termed exomiRs. Research in murine models has demonstrated that exercise can trigger the release of small EVs into the circulation. The aim of this study was to study exomiR release in humans pre and post exercise and to characterise the function of these microRNAs especially in relation to thermogenic fat. We found that exercise increased the release of exomiR-196a-5p in endurance athletes, a microRNA that induces UCP1 expression and browning of white adipocytes. We observed that myotubes specifically release miR-196a-5p within small EVs after in vitro exercise-mimicking conditions such as electrical pulse stimulation and cAMP treatment. Likewise, the expression at basal levels of the exercise-induced exomiR-342-3p negatively correlated with BMI and age. EV proteomics revealed a positive correlation between FABP4+ and miR-342-3p, suggesting an adipocyte cell origin. Overexpression of miR-342-3p increased Myogenin levels during skeletal muscle cell differentiation, indicating a positive role in muscle differentiation. Our results suggest that oxidative extreme metabolic capacities in endurance athletes contribute to the enhanced release of circulatory exomiRs after exercise mediating bi-directional crosstalk between skeletal muscle and thermogenic adipose tissue. Graphical abstractO_LISerum-EVs from endurance athletes increase UCP1 expression in white adipocytes. C_LIO_LImiR-196a and miR-342-3p are increased in serum-EVs from endurance athletes. C_LIO_LIMuscle cells release EVs enriched in miR-196a after electrical pulse stimulation. C_LIO_LImiR-196a and miR-342-3p have browning and myogenic potential, respectively. C_LI O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=143 SRC="FIGDIR/small/656129v1_ufig1.gif" ALT="Figure 1"> View larger version (31K): org.highwire.dtl.DTLVardef@1bd9b25org.highwire.dtl.DTLVardef@114a549org.highwire.dtl.DTLVardef@6f863borg.highwire.dtl.DTLVardef@1d5c528_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

bioRxiv2022

RIG-I activation primes and trains innate antiviral immune memory

Adaptive processes of the innate immune system, known as trained immunity (TI), are critical to human health and disease, yet they have not been systematically investigated downstream of antiviral sensing. Here, we elucidate the potential of the antiviral cytosolic RNA receptor retinoic acid-inducible gene I (RIG-I) to train, prime and tolerize the innate immune system. Using a specific RIG-I agonist, we observed that repetitive stimulation enhanced interferon-stimulated gene (ISG) and pro-inflammatory cytokine induction in human primary monocytes, epithelial cells and fibroblasts and afforded non-specific antiviral protection. RNA sequencing revealed broad, cell type-specific transcriptional changes, indicative of priming of ISGs and training of the NF{kappa}B pathway, without measurable tolerization, while ATAC sequencing in monocytes demonstrated chromatin remodeling and enhanced accessibility of key transcription factor-binding motifs such as STAT1. Moreover, while STAT1 signaling was critically required, it was not sufficient to recapitulate RIG-I induced TI. Altogether, our data demonstrate that RIG-I-mediated TI promotes an immunologically alert state with important implications for host defense and the application of RIG-I ligands in anti-infective and anti-tumoral therapies. One Sentence SummaryRIG-I activation trains and primes innate immune response at the cellular level, affording non-specific immune protection by immune and non-immune cells.

immunology↗