Phenotypic Modifications of Human Mesangial Cells by Extracellular Matrix: The Importance of Matrix in the Contractile Response to Reactive Oxygen Species

Abstract

The progression of chronic renal diseases is characterized by the accumulation of extracellular matrix proteins in the glomerulus. The present experiments were designed to analyze the effect of hydrogen peroxide on the contractile and proliferative phenotypes of human mesangial cells grown on different culture substrates: plastic, collagen type I, and collagen type IV. Contraction was analyzed by measuring planar cell surface area and myosin light chain phosphorylation, whereas proliferation was studied by [³H]thymidine incorporation. No changes were detected in the proliferation rate of human mesangial cells grown on different culture substrates, neither under basal conditions nor in the presence of fetal calf serum or H₂O₂. Cells grown on plastic or collagen did not contract in the presence of H₂O₂, but cells grown on collagen I elicited a significant contraction with H₂O₂. Platelet-activating factor induced contraction of human mesangial cells on the three culture substrates. The different contractile responses observed were not due to different degradation rates of H₂O₂. The present experiments support the importance of extracellular matrix in the response to exogenous stimuli and point to the possibility that patients with changes in the mesangial matrix as a result of chronic renal diseases may have an increased susceptibility to the pathological actions of reactive oxygen species.

Collagen I upregulates extracellular matrix gene expression and secretion of TGF-β1 by cultured human mesangial cells

“…Multiple studies have analyzed the relationships among ECM proteins and cell morphology, proliferation, and apoptosis (3,11,12,16,24,26,31). However, the effect of ECM composition on cytokine synthesis has been poorly explored.…”

“…Trypsinized HMC were seeded (4 ϫ 10 4 cells/cm 2 ) on petri dishes previously treated for 16 h at 4°C with a solution of COL I or COL IV (Sigma) (16). Briefly, culture dishes were coated with 12.5 g/ml COL I or COL IV in bicarbonate buffer (15 mM Na 2CO3 and 35 mM NaHCO3, pH 9) to form a thin film of collagen.…”

The Leukocyte-Endothelial Cell Interactions are Modulated by Extracellular Matrix Proteins

“…Acid soluble COL I and COL IV were purchased from Sigma (St. Louis, MO). Petri dishes were treated with a solution of 12.5 µg/ml collagen in bicarbonate buffer (Na 2 CO 3 15 mM, NaHCO 3 35 mM, pH 9) for 16 hours at 4° C to allow the formation of a thin film of collagen as previously described [20]. Then, the collagen not attached to plastic was discarded and Petri dishes were washed with Hank's balanced solution to restore the pH 7.5.…”

<b><i>Bathysa cuspidata</i></b> Extract Modulates the Morphological Reorganization of the Scar Tissue and Accelerates Skin Wound Healing in Rats: A Time-Dependent Study

“…There is sufficient evidence that the trauma produced by skin wounds is responsible for the formation of free radicals, important pathogenic factors that lead to several degenerative disorders including fibrosis in different organs (e.g. the liver, lungs and skin) [Polosukhin, 1999;Iglesias-de La Cruz et al, 2000]. After analyzing the results, it was observed that the application of the ointment, especially at the higher dose, promoted an increase in the number of fibroblasts, which indicates that these cells retained the machinery for replication and synthesis of extracellular matrix components, particularly collagen fibers.…”