Oishi, S. | Search bioRxiv

bioRxiv2022

NF-κB Decoy ODN-Loaded Poly lactic-co-glycolic Acid Nanospheres Inhibit Alveolar Ridge Resorption

Residual ridge resorption combined with dimensional loss resulting from tooth extraction has a prolonged correlation with early excessive inflammation. Nuclear factor-kappa B (NF-{kappa}B) decoy oligodeoxynucleotide (ODN) is a member of a group of double-stranded DNA capable of downregulating the expression of downstream genes of the NF-{kappa}B pathway. The healing action of its embellished effect combined with poly(lactic-co-glycolic acid) (PLGA) nanospheres on tooth extraction socket still remains unknown. Hence, the aim of this study was to investigate the therapeutic effect of NF-{kappa}B decoy ODN-loaded PLGA nanospheres (PLGA-NfD) transfected into extraction sockets in Wistar/ST rats. Micro-computed tomography and trabecular bone analysis following treatment with PLGA-NfD demonstrated inhibition of vertical alveolar bone loss with increased bone volume, smoother trabecular bone surface, thicker trabecular bone, larger trabecular number and separation, and fewer bone porosities. Histomorphometric and reverse transcription-quantitative polymerase chain reaction analysis revealed reduced tartrate-resistant acid phosphatase-expressing osteoclasts, interleukin-1{beta}, tumor necrosis factor-, receptor activator of NF-{kappa}B ligand, turnover rate and increased transforming growth factor-{beta}1 immunopositive reactions and relative gene expressions. These data demonstrate that local delivery of PLGA-NfD could be used as a substantial suppressor of inflammation during the healing process in a tooth extraction socket, with the potential of accelerated new bone formation.

immunology↗

bioRxiv2021

Systemic regulation of nitrogen acquisition and use in Oryza longistaminata ramets under nitrogen heterogeneity

Oryza longistaminata, a wild rice, vegetatively reproduces and forms a networked clonal colony consisting of ramets connected by rhizomes. Although water, nutrients, and other molecules can be transferred between ramets via the rhizomes, inter-ramet communication in response to spatially heterogeneous nitrogen availability is not well understood. We studied the response of ramet pairs to heterogeneous nitrogen availability by using a split hydroponic system that allowed each ramet root to be exposed to different conditions. Ammonium uptake was compensatively enhanced in the sufficient-side root when roots of the ramet pairs were exposed to ammonium-sufficient and deficient conditions. Comparative transcriptome analysis revealed that a gene regulatory network for effective ammonium assimilation and amino acid biosynthesis was activated in the sufficient-side roots. Allocation of absorbed nitrogen from the nitrogen-sufficient to the deficient ramets was rather limited. Nitrogen was preferentially used for newly growing axillary buds on the sufficient-side ramets. Biosynthesis of trans-zeatin, a cytokinin, was up-regulated in response to the nitrogen supply, but trans-zeatin appears not to target the compensatory regulation. Our results also implied that the O. longistaminata ortholog of OsCEP1 plays a role as a nitrogen-deficient signal in inter-ramet communication, providing compensatory up-regulation of nitrogen assimilatory genes. These results provide insights into the molecular basis for efficient growth strategies of asexually proliferating plants growing in areas where the distribution of ammonium ions is spatially heterogeneous. One sentence summaryOryza longistaminata, a rhizomatous wild rice, systemically regulates ammonium acquisition and use in response to spatially heterogeneous nitrogen availability via inter-ramet communication.

plant biology↗