Design and synthesis of oxytocin glycosides for the treatment of pain and substance use disorder.

Peptide drugs are a promising alternative to classical small molecule therapeutics with diverse applications, ranging from antibiotic resistant infection to prostate cancer. Oxytocin (OT) is a highly evolutionarily conserved peptide neurohormone and has been of interest for pharmaceutical use since 1909. Despite their increased safety profile relative to most small molecule drugs, peptides are poor candidates based on the pharmacokinetic (PK) properties from their peptide nature. Broad application of OT as a drug has been limited by these same PK issues. Several strategies have been proposed to overcome these limitations, among them glycosylation, which was used in combination with other sequence modifications to produce robust antinociception in mouse models, increased selectivity and potency at the OT receptor, and improved stability in rats.

A single-nucleus and spatial transcriptomic atlas of the COVID-19 liver reveals topological, functional, and regenerative organ disruption in patients.

The molecular underpinnings of organ dysfunction in acute COVID-19 and its potential long-term sequelae are under intense investigation. To shed light on these in the context of liver function, we performed single-nucleus RNA-seq and spatial transcriptomic profiling of livers from 17 COVID-19 decedents. We identified hepatocytes positive for SARS-CoV-2 RNA with an expression phenotype resembling infected lung epithelial cells. Integrated analysis and comparisons with healthy controls revealed extensive changes in the cellular composition and expression states in COVID-19 liver, reflecting hepatocellular injury, ductular reaction, pathologic vascular expansion, and fibrogenesis. We also observed Kupffer cell proliferation and erythrocyte progenitors for the first time in a human liver single-cell atlas, resembling similar responses in liver injury in mice and in sepsis, respectively. Despite the absence of a clinical acute liver injury phenotype, endothelial cell composition was dramatically impacted in COVID-19, concomitantly with extensive alterations and profibrogenic activation of reactive cholangiocytes and mesenchymal cells. Our atlas provides novel insights into liver physiology and pathology in COVID-19 and forms a foundational resource for its investigation and understanding.