Comparative characterization of rat hippocampal plasma membrane and mitochondrial membrane proteomes based on a sequential digestion-centered combinative strategy

Gegen Qinlian Decoction abates nonalcoholic steatohepatitis associated liver injuries via anti-oxidative stress and anti-inflammatory response involved inhibition of toll-like receptor 4 signaling pathways

Gegen Qilian Decoction (GGQLD) is a well-established classic Chinese medicine prescription in treating nonalcoholic steatohepatitis (NASH). However, the molecular mechanism of GGQLD action on NASH is still not clear. This study aimed to assess the anti-NASH effect of GGQLD, and to explore its molecular mechanisms in vivo and in vitro. In HFD-fed rats, GGQLD decreased significantly serum triglyceride (TG), cholesterol (CHO), total bile acid (TBA), low-density lipoprotein (LDL), free fatty acid (FFA) and lipopolysaccharide (LPS) levels, increased levels of differentially expressed proteins (DEPs) Ahcy, Gpx1, Mat1a, GNMT, and reduced the expression of ALDOB. In RAW264.7 macrophages, GGQLD reduced the expression levels of inflammatory factors TNF-α and IL-6 mRNA, and diminished NASH by increasing differentially expressed genes (DEGs) CBS, Mat1a, Hnf4α and Pparα to reduce oxidative stress or lipid metabolism. The results of DEGs verification also showed that GGQLD up-regulated expressions of Hnf4α, Pparα and Cbs genes. In HepG2 cells, GGQLD decreased IL-6 levels and intracellular TG content, and inhibited FFA-induced expression of toll-like receptor 4 (TLR4). In summary, GGQLD abates NASH associated liver injuries via anti-oxidative stress and anti-inflammatory response involved inhibition of TLR4 signal pathways. These findings provide new insights into the anti-NASH therapy by GGQLD.

Resolution Matters: Correlating Quantitative Proteomics and Nanoscale-Precision Microscopy for Reconstructing Synapse Identity

For more than a century, the precision at which any protein (or RNA) could be localized in living cells depends on the spatial resolution of microscopy. Light microscopy, even recently benchmarked laser-scanning microscopy, is inherently liable to the diffraction limit of visible light. Electron microscopy that had existed as the only alternative for decades is, in turn, of low throughput and sensitive to processing artefacts. Therefore, researchers have looked for alternative technologies particularly with ever-growing interest in resolving structural underpinnings of cellular heterogeneity in the human body. Computational ("in silico") predictions provided only partial solutions given the incompleteness of existing databases and erroneous assumptions on evolutionarily conserved sequence homology across species. A breakthrough that facilitates subcellular protein localization came with the introduction of "super-resolution" microscopy, which yields 20-60 nm resolution by overcoming diffraction-limited technologies. The ensuing combination of "super-resolution" microscopy with unbiased proteomics continues to produce never-before-seen gains by quantitatively addressing the distribution, interaction, turnover, and secretion of proteins in living cells. Here, we illustrate the power of this combined work flow by the example of transmembrane receptor localization at the neuronal synapse. We also discuss how dynamic analysis allows for inferences be made for cellular physiology and pathobiology.