Orally delivered siRNA targeting macrophage Map4k4 suppresses systemic inflammation

Abstract

Gene silencing by double-stranded RNA, denoted RNA interference, represents a new paradigm for rational drug design1. However, the transformative therapeutic potential of short interfering RNA (siRNA) has been stymied by a key obstacle—safe delivery to specified target cells in vivo2. Macrophages are particularly attractive targets for RNA interference therapy because they promote pathogenic inflammatory responses in diseases such as rheumatoid arthritis, atherosclerosis, inflammatory bowel disease and diabetes3. Here we report the engineering of β1,3-d-glucan-encapsulated siRNA particles (GeRPs) as efficient oral delivery vehicles that potently silence genes in mouse macrophages in vitro and in vivo. Oral gavage of mice with GeRPs containing as little as 20 µg kg−1 siRNA directed against tumour necrosis factor α (Tnf-α)depleted its messenger RNA in macrophages recovered from the peritoneum, spleen, liver and lung, and lowered serum Tnf-α levels. Screening with GeRPs for inflammation genes revealed that the mitogen-activated protein kinase kinase kinase kinase 4 (Map4k4) is a previously unknown mediator of cytokine expression. Importantly, silencing Map4k4 in macrophages in vivo protected mice from lipopolysaccharide-induced lethality by inhibiting Tnf-α and interleukin-1β production. This technology defines a new strategy for oral delivery of siRNA to attenuate inflammatory responses in human disease.

MiR-29a Assists in Preventing the Activation of Human Stellate Cells and Promotes Recovery From Liver Fibrosis in Mice

“…Mitogen-activated protein kinase kinase kinase kinase 4 (ref. 20) and PDGFC were also chosen and genes with expression levels that were lower in 2-week miR-29a livers than in the NC miRNA (Figure 4b,c). Applying these constraints, we validated the expression of three genes by real-time polymerase chain reaction (PCR) analysis (Figure 4d).…”

Germinal center kinases in immune regulation

“…121 RNA interference targeting macrophage NIK protected mice from lipopolysaccharide-induced lethality by preventing TNF-a and IL-1b secretion. 122 The GCK-V subfamily member LOK is a 130-kDa serine/threonine kinase predominantly expressed in lymphoid tissues. 123 LOK does not activate MAPK signaling but is involved in LFA-1-mediated lymphocyte adhesion.…”

miRNA-141, Downregulated in Pancreatic Cancer, Inhibits Cell Proliferation and Invasion by Directly Targeting MAP4K4

“…Recent studies have shown that MAP4K4 is associated with cell motility, rearrangement of the cytoskeleton, and cell growth (26)(27)(28). Downregulation of MAP4K4 prevents TNF-a-induced insulin resistance in human skeletal muscle (29), and suppresses systemic inflammation by targeting macrophages (30). Moreover, MAP4K4 is overexpressed in diverse types of human cancer (31).…”