TY - JOUR

T1 - SILAC-MS Based Characterization of LPS and Resveratrol Induced Changes in Adipocyte Proteomics - Resveratrol as Ameliorating Factor on LPS Induced Changes

AU - Nøhr, Mark K

AU - Kroager, Toke P

AU - Sanggaard, Kristian W

AU - Knudsen, Anders D

AU - Stensballe, Allan

AU - Enghild, Jan J

AU - Ølholm, Jens

AU - Richelsen, Bjørn

AU - Pedersen, Steen B

PY - 2016

Y1 - 2016

N2 - Adipose tissue inflammation is believed to play a pivotal role in the development obesity-related morbidities such as insulin resistance. However, it is not known how this (low-grade) inflammatory state develops. It has been proposed that the leakage of lipopolysaccharides (LPS), originating from the gut microbiota, through the gut epithelium could drive initiation of inflammation. To get a better understanding of which proteins and intracellular pathways are affected by LPS in adipocytes, we performed SILAC proteomic analysis and identified proteins that were altered in expression. Furthermore, we tested the anti-inflammatory compound resveratrol. A total of 927 proteins were quantified by the SILAC method and of these 57- and 64 were significantly up- and downregulated by LPS, respectively. Bioinformatic analysis (GO analysis) revealed that the upregulated proteins were especially involved in the pathways of respiratory electron transport chain and inflammation. The downregulated proteins were especially involved in protein glycosylation. One of the latter proteins, GALNT2, has previously been described to regulate the expression of liver lipases such as ANGPTL3 and apoC-III affecting lipid metabolism. Furthermore, LPS treatment reduced the protein levels of the insulin sensitizing adipokine, adiponectin, and proteins participating in the final steps of triglyceride- and cholesterol synthesis. Generally, resveratrol opposed the effect induced by LPS and, as such, functioning as an ameliorating factor in disease state. Using an unbiased proteomic approach, we present novel insight of how the proteome is altered in adipocytes in response to LPS as seen in obesity. We suggest that LPS partly exerts its detrimental effects by altering glycosylation processes of the cell, which is starting to emerge as important posttranscriptional regulators of protein expression. Furthermore, resveratrol could be a prime candidate in ameliorating dysfunctioning adipose tissue induced by inflammatory stimulation.

AB - Adipose tissue inflammation is believed to play a pivotal role in the development obesity-related morbidities such as insulin resistance. However, it is not known how this (low-grade) inflammatory state develops. It has been proposed that the leakage of lipopolysaccharides (LPS), originating from the gut microbiota, through the gut epithelium could drive initiation of inflammation. To get a better understanding of which proteins and intracellular pathways are affected by LPS in adipocytes, we performed SILAC proteomic analysis and identified proteins that were altered in expression. Furthermore, we tested the anti-inflammatory compound resveratrol. A total of 927 proteins were quantified by the SILAC method and of these 57- and 64 were significantly up- and downregulated by LPS, respectively. Bioinformatic analysis (GO analysis) revealed that the upregulated proteins were especially involved in the pathways of respiratory electron transport chain and inflammation. The downregulated proteins were especially involved in protein glycosylation. One of the latter proteins, GALNT2, has previously been described to regulate the expression of liver lipases such as ANGPTL3 and apoC-III affecting lipid metabolism. Furthermore, LPS treatment reduced the protein levels of the insulin sensitizing adipokine, adiponectin, and proteins participating in the final steps of triglyceride- and cholesterol synthesis. Generally, resveratrol opposed the effect induced by LPS and, as such, functioning as an ameliorating factor in disease state. Using an unbiased proteomic approach, we present novel insight of how the proteome is altered in adipocytes in response to LPS as seen in obesity. We suggest that LPS partly exerts its detrimental effects by altering glycosylation processes of the cell, which is starting to emerge as important posttranscriptional regulators of protein expression. Furthermore, resveratrol could be a prime candidate in ameliorating dysfunctioning adipose tissue induced by inflammatory stimulation.

KW - Adipocytes/metabolism

KW - Adipose Tissue/metabolism

KW - Angiopoietin-like Proteins

KW - Angiopoietins/biosynthesis

KW - Gastrointestinal Microbiome/drug effects

KW - Gene Expression Regulation/drug effects

KW - Glycosylation/drug effects

KW - Humans

KW - Inflammation/drug therapy

KW - Insulin/metabolism

KW - Insulin Resistance/genetics

KW - Lipid Metabolism

KW - Lipogenesis/drug effects

KW - Lipopolysaccharides/metabolism

KW - N-Acetylgalactosaminyltransferases/biosynthesis

KW - Obesity/drug therapy

KW - Proteome/genetics

KW - Proteomics

KW - Stilbenes/administration & dosage

U2 - 10.1371/journal.pone.0159747

DO - 10.1371/journal.pone.0159747

M3 - Journal article

C2 - 27438462

VL - 11

SP - e0159747

JO - PLoS ONE

JF - PLoS ONE

SN - 1932-6203

IS - 7

ER -