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Tjang, L. V.

Publications and source records attributed to Tjang, L. V..

2 recordsLinked to original sources

Methods and techniques enabling multi-kilobase long-range genomic rewrite/replace editing

CRISPR enabled cell and gene therapies have the potential to revolutionize the field of genetic medicine. However, the vast majority of rare diseases remain untreatable due to the limitations of current tools and techniques. To date, most corrective therapeutic approaches have been restricted to mutation-by-mutation approaches, where either HDR, or newer techniques such as base or prime editing, rewrite small regions of DNA at a time ([~]1-100 bp). While these approaches are powerful, short editing windows (relative to the size of human genes) are financially and/or technically incompatible with most rare-disease mutation profiles. Here, we demonstrate for the first time that CRISPR/Cas9 can be used to "rewrite" 7kb+ sections of the human genome simultaneously via a selection-free process we have named "long-range rewriting". Long-range rewriting approaches are compatible with multiple nucleases, cell types and genomic loci, and can be used with both double-strand break (DSB) and non-DSB based approaches.

genetics↗

SARS-CoV-2 Spike triggers barrier dysfunction and vascular leak via integrins and TGF-β signaling

Severe COVID-19 is associated with epithelial and endothelial barrier dysfunction within the lung as well as in distal organs. While it is appreciated that an exaggerated inflammatory response is associated with barrier dysfunction, the triggers of this pathology are unclear. Here, we report that cell-intrinsic interactions between the Spike (S) glycoprotein of SARS-CoV-2 and epithelial/endothelial cells are sufficient to trigger barrier dysfunction in vitro and vascular leak in vivo, independently of viral replication and the ACE2 receptor. We identify an S-triggered transcriptional response associated with extracellular matrix reorganization and TGF-{beta} signaling. Using genetic knockouts and specific inhibitors, we demonstrate that glycosaminoglycans, integrins, and the TGF-{beta} signaling axis are required for S-mediated barrier dysfunction. Our findings suggest that S interactions with barrier cells are a contributing factor to COVID-19 disease severity and offer mechanistic insight into SARS-CoV-2 triggered vascular leak, providing a starting point for development of therapies targeting COVID-19 pathogenesis.

microbiology↗