Sopida Pimcharoen

All Publications

• Human cathelicidin peptide LL-37 compacts nucleic acids and alters neutrophil extracellular trap structure. Scientific reports Zielke, C., Rad, B., Nielsen, J. E., Li, J., Pimcharoen, S., Sawant, M., Kamayirese, S., Lin, J. S., Thiam, H. R., Barron, A. E. 2026

  Abstract

  The human cathelicidin host defense peptide LL-37 is expressed by many cell types, including neutrophils, macrophages, and epithelial cells, and forms complexes with nucleic acids that can have either beneficial or detrimental health effects. We suggest that these differential impacts are directly connected to the extent of nucleic acid binding by LL-37. Here, we use phage λ DNA and techniques such as high-resolution video microscopy, gel electrophoresis, circular dichroism, and displacement assays to show that LL-37 binds non-specifically to dsDNA, condensing it, followed by formation of progressively larger complexes from smaller domains, until "complete" complexation is attained at a (w/w) ratio of DNA/LL-37 of 1:1.7. The morphology of these complexes is concentration-dependent, with relatively low LL-37 amounts yielding loosely aggregated DNA structures and higher LL-37 concentrations leading to well-defined, disc-like complexes of about 150 nm in diameter. The condensation of nucleic acids, which causes a loss of the characteristic B-DNA features, results from interactions of the phosphodiester backbone with cationic amino acid side chains of the peptide at physiological pH, most likely in A-T rich sequences of the nucleic acid. Our results show that the α-helical structure of the peptide with its amphipathic and hydrophobic surfaces is essential. Finally, we show that LL-37 complexation alters the structure of neutrophil extracellular traps (NETs), causing a significant reduction in projected NET area at high LL-37 concentrations. Our data suggest that LL-37 helps prevent nucleic acid dispersal and condenses dsDNA, which may impact the biophysics of NET clearance.

  View details for DOI 10.1038/s41598-026-48091-4

  View details for PubMedID 42156793

• A CRISPR-Cas13d cancer therapeutic enables selective elimination of uveal melanoma MOLECULAR THERAPY ONCOLOGY Stauber, D., Sosnick, L., Ma, Y., Pimcharoen, S., Lawanprasert, A., Murthy, N., Myung, D., Qi, L. S. 2026; 34 (1)

  View details for DOI 10.1016/j.omton.2026.201151

  View details for Web of Science ID 001705061600001

• A CRISPR-Cas13d cancer therapeutic enables selective elimination of uveal melanoma. Molecular therapy. Oncology Stauber, D., Sosnick, L., Ma, Y., Pimcharoen, S., Lawanprasert, A., Murthy, N., Myung, D., Qi, L. S. 2026; 34 (1): 201151

  Abstract

  Uveal melanoma, the most common eye cancer in adults, remains limited to surgical intervention and radiotherapy, with a dismal survival rate that has not improved in over 50 years. To address this therapeutic impasse, we systematically analyzed public gene expression and CRISPR knockout datasets, identifying RASGRP3 as an essential gene specifically for uveal melanoma. RasGRP3 is uniquely overexpressed and essential for survival in uveal melanoma cells, but dispensable in healthy cells. However, RasGRP3 remains "undruggable" due to its intracellular localization and lack of targetable binding pockets. To overcome this, we developed a CRISPR-Cas13d RNA-targeting therapeutic against RasGRP3, which mediates potent yet selective uveal melanoma killing through two synergistic mechanisms: (1) on-target knockdown of the essential RasGRP3 mRNA, and (2) collateral RNA degradation triggered by the cleavage of overexpressed RasGRP3. When delivered in vitro via optimized lipid nanoparticles loaded with Cas13d mRNA and guide RNA, this strategy eliminated >97% of uveal melanoma cells while sparing healthy cells, including retinal pigment epithelial cells. This approach outperformed conventional Cas9 and siRNA methods in potency without inducing permanent genomic alterations. Our findings establish an RNA-targeting therapeutic for uveal melanoma and a framework for Cas13-based interventions against other "undruggable" cancers.

  View details for DOI 10.1016/j.omton.2026.201151

  View details for PubMedID 41994560

  View details for PubMedCentralID PMC13080610

• Investigation of Regulation and Binding Patterns of the Human Cathelicidin Peptide LL-37 in Complexation with Nucleic Acids, and its Impact on Neutrophil Extracellular Traps. bioRxiv : the preprint server for biology Zielke, C., Rad, B., Nielsen, J. E., Li, J., Pimcharoen, S., Sawant, M., Lin, J. S., Thiam, H. R., Barron, A. E. 2026

  Abstract

  The human cathelicidin host defense peptide LL-37 forms complexes with nucleic acids that can have either beneficial or detrimental health effects. We suggest that these differential impacts are directly connected to dsDNA binding by LL-37 and to complex formation between protomers. Here, we show using phage λ DNA that LL-37 binds non-specifically to dsDNA, condensing it, followed by complex formation between LL-37 peptides. We find that complex formation is concentration-dependent, with low LL-37 amounts yielding loosely aggregated DNA structures, while higher LL-37 concentrations lead to well-defined, disc-like structures of about 150 nm in diameter. The condensation of the nucleic acids, which causes a loss of the characteristic B-DNA features, results from interactions of the phosphodiester backbone with protonated amino acid side chains of the peptide at physiological pH, predominantly in A-T rich sequences of the nucleic acid. However, in our studies, electrostatic interactions did not appear to be the driving force for complexation, but rather we found the α-helical structure of the peptide with its amphipathic and hydrophobic surfaces to be essential. Further, we show that LL-37 also interacts with nucleic acids from neutrophil extracellular traps (NETs) in a concentration-dependent way, causing a reduction in NET aggregate area, which may offer new biophysical insights into diseases such as systemic lupus erythematosus (SLE), which involve slower-than-normal NET clearance. Our results indicate the key importance of LL-37 expression levels for regulation of the innate immune system for optimal human health, since the relative amounts of expressed LL-37 present to interact with extracellular DNA will determine the extent to which the DNA can be condensed, which in turn will affect the ability of the body to clear the NETs before they can cause inflammatory conditions.

  View details for DOI 10.64898/2026.02.09.704888

  View details for PubMedID 41727055

  View details for PubMedCentralID PMC12918999

• CRISPR activation of the ribosome-associated quality control factor ASCC3 ameliorates fragile X syndrome phenotypes in mice. Science translational medicine Geng, J., Wang, X., Pan, J., Khan, D., Pimcharoen, S., Zhang, Y., Mosammaparast, N., Hirose, S., Petrucelli, L., Brandman, O., Qi, L. S., Lu, B. 2025; 17 (819): eadq3551

  Abstract

  Loss of fragile X messenger ribonucleoprotein (FMRP) causes fragile X syndrome (FXS), an inherited neurodevelopmental disorder resulting in intellectual disability and autism spectrum disorder; however, the molecular function of FMRP remains uncertain. Here, using cell lines and fibroblasts and induced pluripotent stem cell-derived neurons from healthy individuals and patients with FXS, we showed that FMRP regulates collided ribosomes by recruiting activating signal cointegrator 1 complex subunit 3 (ASCC3), an early-acting ribosome-associated quality control (RQC) factor to collided ribosomes, and either positively or negatively regulating translation, depending on transcript context. Disease-associated ASCC3 variants that perturbed ASCC3-FMRP interaction were also found to be defective in ribosome association and handling of collided ribosomes. In cells of a patient with FXS and the Fmr1 KO mouse model, ASCC3 abundance was reduced, and overexpression of ASCC3 in the brains of fetal Fmr1 KO mice promoted neuronal migration. In addition, CRISPR-mediated activation of ASCC3 by lateral ventricular injection of adeno-associated virus (AAV) ameliorated synaptic defects and improved locomotor activity, cognitive deficits, obsessive-compulsive-like behavior, and social interaction deficits after 1 month in 2-month-old Fmr1 KO mice compared with untreated Fmr1 KO controls. In conclusion, these data implicated FMRP in the handling of collided ribosomes to maintain protein homeostasis during neurodevelopment and synaptogenesis and demonstrated proof of concept that targeting RQC may offer alternative treatment strategies for FXS.

  View details for DOI 10.1126/scitranslmed.adq3551

  View details for PubMedID 41061044

• CRISPR-Cas13d-Mediated Targeting of a Context-Specific Essential Gene Enables Selective Elimination of Uveal Melanoma. bioRxiv : the preprint server for biology Stauber, D., Sosnick, L., Ma, Y., Pimcharoen, S., Lawanprasert, A., Murthy, N., Myung, D., Qi, L. S. 2025

  Abstract

  Uveal melanoma, the most common eye cancer in adults, remains limited to surgical intervention and chemotherapy, with a dismal survival rate that has not improved in over 50 years. To address this therapeutic impasse, we systematically analyzed public gene expression, RNAi, and CRISPR knockout datasets and identified RASGRP3 as an essential gene specifically for uveal melanoma. RasGRP3 is uniquely overexpressed and essential for survival in uveal melanoma cells, but dispensable in healthy cells. RasGRP3 remains "undruggable" due to its intracellular localization and lack of targetable binding pockets. To overcome this, we developed a CRISPR-Cas13d RNA-targeting therapeutic that specifically knocks down RasGRP3 mRNA. This Cas13d-based therapeutic mediates selective uveal melanoma killing through two synergistic mechanisms: (i) direct silencing of the essential RasGRP3 transcript, and (ii) collateral RNA degradation triggered by the cleavage of overexpressed RasGRP3. When delivered via optimized lipid nanoparticles encoding Cas13d mRNA and guide RNA, this strategy eliminated >97% of uveal melanoma cells while sparing healthy cells, including retinal pigment epithelial cells. This approach outperformed conventional Cas9 and siRNA methods in potency without inducing permanent genomic alterations. Our findings establish a RNA-targeting therapeutic for uveal melanoma and a framework for Cas13d-based interventions against broad "undruggable" cancers.

  View details for DOI 10.1101/2025.08.21.671629

  View details for PubMedID 40894775

  View details for PubMedCentralID PMC12393512

• Acid-degradable lipid nanoparticles enhance the delivery of mRNA. Nature nanotechnology Zhao, S., Gao, K., Han, H., Stenzel, M., Yin, B., Song, H., Lawanprasert, A., Nielsen, J. E., Sharma, R., Arogundade, O. H., Pimcharoen, S., Chen, Y. J., Paul, A., Tuma, J., Collins, M. G., Wyle, Y., Cranick, M. G., Burgstone, B. W., Perez, B. S., Barron, A. E., Smith, A. M., Lee, H. Y., Wang, A., Murthy, N. 2024

  Abstract

  Lipid nanoparticle (LNP)-mRNA complexes are transforming medicine. However, the medical applications of LNPs are limited by their low endosomal disruption rates, high toxicity and long tissue persistence times. LNPs that rapidly hydrolyse in endosomes (RD-LNPs) could solve the problems limiting LNP-based therapeutics and dramatically expand their applications but have been challenging to synthesize. Here we present an acid-degradable linker termed 'azido-acetal' that hydrolyses in endosomes within minutes and enables the production of RD-LNPs. Acid-degradable lipids composed of polyethylene glycol lipids, anionic lipids and cationic lipids were synthesized with the azido-acetal linker and used to generate RD-LNPs, which significantly improved the performance of LNP-mRNA complexes in vitro and in vivo. Collectively, RD-LNPs delivered mRNA more efficiently to the liver, lung, spleen and brains of mice and to haematopoietic stem and progenitor cells in vitro than conventional LNPs. These experiments demonstrate that engineering LNP hydrolysis rates in vivo has great potential for expanding the medical applications of LNPs.

  View details for DOI 10.1038/s41565-024-01765-4

  View details for PubMedID 39179796

  View details for PubMedCentralID 10190134