Insulin-Like Growth Factor Binding Protein 7 and Tissue Inhibitor of Metalloproteinases-2: Differential Expression and Secretion in Human Kidney Tubule Cells.

Insulin-Like Growth Factor Binding Protein 7 and Tissue Inhibitor of Metalloproteinases-2: Differential Expression and Secretion in Human Kidney Tubule Cells. Am J Physiol Renal Physiol. 2016 Dec 21;:ajprenal.00271.2016 Authors: Emlet DR, Pastor-Soler N, Marciszyn A, Wen X, Gomez H, Humphries WH, Morrisroe S, Volpe JK, Kellum JA Abstract We have characterized the expression and secretion of the acute kidney injury biomarkers Insulin-Like Growth Factor Binding Protein 7 (IGFBP7) and Tissue Inhibitor of Metalloproteinases-2 (TIMP-2) in human kidney epithelial cells in primary cell culture and tissue. We established cell culture model systems of primary kidney cells of proximal and distal tubule origin and observed that both proteins are indeed expressed and secreted in both tubule cell types in vitro. However, TIMP-2 is both expressed and secreted preferentially by cells of distal tubule origin, while IGFBP7 is equally expressed across tubule cell types yet preferentially secreted by cells of proximal tubule origin. In human kidney tissue, strong staining of IGFBP7 was seen in the luminal brush border region of a subset of proximal tubule cells, and TIMP-2 stained intracellularly in distal tubules. Additionally, while some tubular co-localization of both biomarkers was identified with the injury markers Kidney Injury Molecule-1 and Neutrophil Gelatinase-Associated Lipocalin, both biomarkers could also be seen alone, suggesting the poss...
Source: Am J Physiol Renal P... - Category: Urology & Nephrology Authors: Tags: Am J Physiol Renal Physiol Source Type: research