Biology subjects

Ryu, J.-H.

Publications and source records attributed to Ryu, J.-H..

3 recordsLinked to original sources

bioRxiv2026

YAP activation reverses aging-related visual dysfunction caused by impaired cell-matrix adhesion

Cellular senescence of retinal pigment epithelium (RPE) cells drives age-related visual decline, particularly in the pathology of age-related macular degeneration (AMD). While genome-wide association studies (GWAS) have identified genetic risk factors underlying AMD, the molecular mechanisms governing RPE senescence remain unclear. Here, single-cell RNA sequencing of young and old mouse RPE revealed dysregulated cell-matrix adhesion as a key feature of senescence, consistent with transcriptional changes in AMD patients. Hydrogel-based experiments confirmed that impaired integrin-mediated adhesion induces RPE senescence. Yes-associated protein 1 (YAP), a crucial mechanotransducer, mediated the protective effects of cell-matrix adhesion, and its activation alone reversed aging phenotypes in senescent RPE cells. Notably, treatment with TRULI, a small-molecule YAP activator, significantly improved visual function in AMD and naturally aged mice. These findings highlight the integrin-YAP mechanotransduction pathway as a fundamental regulator of RPE senescence and a potential therapeutic target for AMD.

physiology↗

bioRxiv2022

Optimizing CpG spatial distribution with DNA origami for Th1-polarized therapeutic vaccination

Multivalent presentation of ligands often enhances receptor activation and downstream signaling. DNA origami offers precise nanoscale spacing of ligands, a potentially useful feature for therapeutic nanoparticles. Here we introduce a "square block" DNA origami platform to explore the importance of spacing of CpG oligonucleotides, which engage Toll-like receptors and thereby act as danger signals for dendritic cells. Through in vitro cell-culture studies and in vivo tumor-treatment models, we demonstrate that square blocks induce Th1 immune polarization when CpG is spaced at 3.5 nm. We observe that this DNA origami vaccine enhances DC activation, antigen cross-presentation, CD8 T cell activation, Th1-polarized CD4 activation and NK cell activation. The vaccine also synergizes effectively with anti-PD-L1 for improved cancer immunotherapy in melanoma and lymphoma models and induces long-term T cell memory. Our results suggest that DNA origami may serve as an advanced vaccine platform for controlling adjuvant spacing and co-delivering antigens. One Sentence SummaryThis study developed a DNA origami-based cancer vaccine (DoriVac) that co-delivers antigen and CpG immune adjuvant with an optimal nanospacing for Th1 immune polarization.

synthetic biology↗

bioRxiv2019

ADCK4 deficiency destabilizes the coenzyme Q complex, which is rescued by 2,4-dihydroxybenzoic acid treatment

ADCK4 mutations usually manifest as steroid-resistant nephrotic syndrome, and cause coenzyme Q10 (CoQ10) deficiency. However, the function of ADCK4 remains obscure. We investigated ADCK4 function using mouse and cell models. Podocyte-specific Adck4 deletion in mice significantly reduced survival and caused severe focal segmental glomerular sclerosis with extensive interstitial fibrosis and tubular atrophy, which were prevented by treatment with 2,4-dihydroxybenzoic acid (2,4-diHB), an analog of CoQ10 precursor molecule. ADCK4 knockout podocytes exhibited significantly decreased CoQ10 level, respiratory chain activity, mitochondrial potential, and dysmorphic mitochondria with loss of cristae formation, which were rescued by 2,4-diHB treatment, thus attributing these phenotypes to decreased CoQ10 levels. ADCK4 interacted with mitochondrial proteins including COQ5, and also cytoplasmic proteins including myosin and heat shock proteins. ADCK4 knockout decreased COQ complex levels, and the COQ5 level was rescued by ADCK4 overexpression in ADCK4 knockout podocytes. Overall, ADCK4 is required for CoQ10 biosynthesis and mitochondrial function in podocytes.

genetics↗