Antisense RNA technology is a strategy for the treatment of Duchenne muscular dystrophy (DMD), a progressive and universally fatal X-linked neuromuscular disease caused by frameshift mutations in the gene encoding dystrophin. Phosphorodiamidate morpholino oligomers (PMOs) are an antisense RNA platform that is used clinically in patients with DMD to facilitate exon skipping and production of an internally truncated, yet functional, dystrophin protein. Peptide-conjugated PMOs (PPMOs) are a next-generation platform in which a cell-penetrating peptide is conjugated to the PMO backbone, with the goal of increasing cellular uptake.
View Article and Find Full Text PDFTherapeutic macromolecules such as proteins and oligonucleotides can be highly efficacious but are often limited to extracellular targets due to the cell's impermeable membrane. Cell-penetrating peptides (CPPs) are able to deliver such macromolecules into cells, but limited structure-activity relationships and inconsistent literature reports make it difficult to design effective CPPs for a given cargo. For example, polyarginine motifs are common in CPPs, promoting cell uptake at the expense of systemic toxicity.
View Article and Find Full Text PDFPurpose: Peptide-conjugated phosphorodiamidate morpholino oligomers (PPMOs) have shown promise in treating Duchenne muscular dystrophy (DMD). We evaluated a semi-mechanistic pharmacokinetic (PK) and pharmacodynamic (PD) model to capture the relationship between plasma and muscle tissue exposure/response in mdx mice treated by mouse surrogate PPMO.
Methods: A single or repeated (every 4 weeks for 20 weeks) intravenous PPMO dose was administered to mdx mice (n = 6/timepoint).
There are more amino acid permutations within a 40-residue sequence than atoms on Earth. This vast chemical search space hinders the use of human learning to design functional polymers. Here we show how machine learning enables the de novo design of abiotic nuclear-targeting miniproteins to traffic antisense oligomers to the nucleus of cells.
View Article and Find Full Text PDFCytoskeletal remodeling of hematopoietic stem and progenitor cells (HSPCs) is essential for homing to the bone marrow (BM). The Ras-related C3 botulinum toxin substrate (Rac)/cell division control protein 42 homolog (CDC42) effector p21-activated kinase (Pak2) has been implicated in HSPC homing and engraftment. However, the molecular pathways mediating Pak2 functions in HSPCs are unknown.
View Article and Find Full Text PDFSystemic Mastocytosis (SM) is a clonal disease characterized by abnormal accumulation of mast cells in multiple organs. Clinical presentations of the disease vary widely from indolent to aggressive forms, and to the exceedingly rare mast cell leukemia. Current treatment of aggressive SM and mast cell leukemia is unsatisfactory.
View Article and Find Full Text PDFRhoH is a hematopoietic-specific, GTPase-deficient member of the Rho GTPase family that was first identified as a hypermutable gene in human B lineage lymphomas. RhoH remains in a constitutively active state and thus its effects are regulated by expression levels or post-translational modifications. Similar to other small GTPases, intracellular localization of RhoH is dependent upon the conserved "CAAX" box and surrounding sequences within the carboxyl (C) terminus.
View Article and Find Full Text PDFTrafficking of B-cell chronic lymphocytic leukemia (CLL) cells to the bone marrow and interaction with supporting stromal cells mediates important survival and proliferation signals. Previous studies have demonstrated that deletion of Rhoh led to a delayed disease onset in a murine model of CLL. Here we assessed the impact of RhoH on homing, migration, and cell-contact dependent interactions of CLL cells.
View Article and Find Full Text PDFBackground: The metabolic syndrome is an obesity-associated disease manifested as severe insulin resistance, hyperlipidemia, hepatic steatosis, and diabetes. Previously we proposed that a nonapeptide, FIAWLVKGRamide, GLP-1(28-36)amide, derived from the gluco-incretin hormone, glucagon-like peptide-1 (GLP-1), might have insulin-like actions. Recently, we reported that the nonapeptide appears to enter hepatocytes, target to mitochondria, and suppress glucose production and reactive oxygen species.
View Article and Find Full Text PDF