Ectopic expression of DOCK8 regulates lysosome-mediated pancreatic tumor cell invasion.

Amplified lysosome activity is a hallmark of pancreatic ductal adenocarcinoma (PDAC) orchestrated by oncogenic KRAS that mediates tumor growth and metastasis, though the mechanisms underlying this phenomenon remain unclear. Using comparative proteomics, we found that oncogenic KRAS significantly enriches levels of the guanine nucleotide exchange factor (GEF) dedicator of cytokinesis 8 (DOCK8) on lysosomes. Surprisingly, DOCK8 is aberrantly expressed in a subset of PDAC, where it promotes cell invasion in vitro and in vivo.

A Comparative Proteomic Analysis of Extracellular Vesicles Associated With Lipotoxicity.

Extracellular vesicles (EVs) are emerging mediators of intercellular communication in nonalcoholic steatohepatitis (NASH). Palmitate, a lipotoxic saturated fatty acid, activates hepatocellular endoplasmic reticulum stress, which has been demonstrated to be important in NASH pathogenesis, including in the release of EVs. We have previously demonstrated that the release of palmitate-stimulated EVs is dependent on the synthesis of ceramide, which is trafficked by the ceramide transport protein, STARD11.

A size-exclusion-based approach for purifying extracellular vesicles from human plasma.

Extracellular vesicles (EVs) are released into blood from multiple organs and carry molecular cargo that facilitates inter-organ communication and an integrated response to physiological and pathological stimuli. Interrogation of the protein cargo of EVs is currently limited by the absence of optimal and reproducible approaches for purifying plasma EVs that are suitable for downstream proteomic analyses. We describe a size-exclusion chromatography (SEC)-based method to purify EVs from platelet-poor plasma (PPP) for proteomics profiling via high-resolution mass spectrometry (SEC-MS).

TBK1 regulates regeneration of pancreatic β-cells.

Small-molecule inhibitors of non-canonical IκB kinases TANK-binding kinase 1 (TBK1) and IκB kinase ε (IKKε) have shown to stimulate β-cell regeneration in multiple species. Here we demonstrate that TBK1 is predominantly expressed in β-cells in mammalian islets. Proteomic and transcriptome analyses revealed that genetic silencing of TBK1 increased expression of proteins and genes essential for cell proliferation in INS-1 832/13 rat β-cells.