1. Growth Differentiation Factor-15-Induced Contractile Activity and Extracellular Matrix Production in Human Trabecular Meshwork Cells.
- Author
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Muralidharan AR, Maddala R, Skiba NP, and Rao PV
- Subjects
- Cells, Cultured, Glaucoma, Open-Angle metabolism, Glaucoma, Open-Angle pathology, Growth Differentiation Factor 15 biosynthesis, Humans, Immunoblotting, Immunohistochemistry, Mass Spectrometry, Oligonucleotide Array Sequence Analysis, Real-Time Polymerase Chain Reaction, Signal Transduction, Trabecular Meshwork pathology, Aqueous Humor metabolism, Extracellular Matrix metabolism, Gene Expression Regulation, Glaucoma, Open-Angle genetics, Growth Differentiation Factor 15 genetics, RNA genetics, Trabecular Meshwork metabolism
- Abstract
Purpose: To determine the role and regulation of growth differentiation factor-15 (GDF-15), a TGF-β-related cytokine in human trabecular meshwork (TM) cells in the context of aqueous humor (AH) outflow and IOP., Methods: Regulation of expression by external cues, and the distribution and secretion of GDF-15 by human TM primary cell cultures, and the effects of recombinant (r) GDF-15 on TM cell contractile characteristics, actin cytoskeleton, cell adhesion, extracellular matrix (ECM), α-smooth muscle actin (αSMA), SMAD signaling, and gene expression were determined by immunoblot, immunofluorescence, mass spectrometry, cDNA microarray, and real-time quantitative PCR (RT-qPCR) analyses., Results: Growth differentiation factor-15, a common constituent of ECM derived from the human TM cells, was confirmed to be distributed throughout the conventional aqueous humor outflow pathway of the human eye. Growth differentiation factor-15 protein levels were significantly increased in human TM cells in response to TGF-β2, dexamethasone, endothelin-1, lysophosphatidic acid, TNF-α, IL-1β treatment, and by cyclic mechanical stretch. Stimulation of human TM cells with rGDF-15 caused a significant increase in the formation of actin stress fibers and focal adhesions, myosin light chain phosphorylation, SMAD signaling, gene expression, and the levels of αSMA and ECM proteins., Conclusions: The results of this study, including a robust induction of GDF-15 expression by several external factors known to elevate IOP, and rGDF-15-induced increase in contractility, cell adhesion, and the levels of ECM proteins and αSMA in TM cells, collectively suggest a potential role for GDF-15 in homeostasis and dysregulation of AH outflow and IOP in normal and glaucomatous eyes, respectively.
- Published
- 2016
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