TY - JOUR
T1 - The effects of endothelin-1 on human dermal fibroblast growth and synthetic activity
AU - Falanga, Vincent
AU - Katz, Matthew H.
AU - Kirsner, Robert
AU - Alvarez, Alfred F.
N1 - Funding Information:
’ This work was supported Grant AR39658. ’ To whom reprint requests
PY - 1992/11
Y1 - 1992/11
N2 - Endothelin-1 (ET-1) is the most potent vasoconstricting substance known, and is believed to have a fundamental role in the regulation of blood flow. It is a peptide produced and secreted by endothelial cells in response to hypoxia and injury, as well as by macrophages. These properties suggest that ET-1 may play a role during tissue repair. In this study, we have examined the effects of ET-1 on the growth and synthetic activity of human dermal fibroblasts. ET-1 stimulated DNA synthesis in serum-deprived cultures: this effect reached a mean value of 64% more than control (P < 0.01) at 2.5 ng/ml (10-9, M) of ET-1. In contrast, the addition of ET-1 to fibroblasts at different densities and in 0, 3, or 10% fetal bovine serum (FBS) failed to increase cell counts. In 1% FBS, a 41% mean increase in cell counts compared to control values was observed in cultures treated with 2.5 ng/ml of ET-1 (P < 0.01). Incubation of dermal fibroblast cultures at 37°C for 1 hr with increasing concentrations of 125I-ET-1 resulted in saturable binding and a half-maximal specific binding of 27.5 pM. Scatchard plot analysis of the binding showed a Kd of 224 pM and 11,400 high-affinity binding sites per cell. ET-1 had no effect on [14C]-glucosamine incorporation by fibroblasts and caused no increase in collagen synthesis, as measured by collagenase-sensitive [3H]proline incorporation and by salt precipitation of 3H-labeled collagen at acid and neutral pH successively. In summary, ET-1 binds to fibroblasts through specific high-affinity surface receptors, but has no obvious direct effect on macromolecular synthesis. ET-1 stimulates [3H]thymidine uptake, but has marginal effects on cell growth. We conclude that any role of ET-1 in tissue repair is probably due to its hemodynamic effects and not as a growth factor.
AB - Endothelin-1 (ET-1) is the most potent vasoconstricting substance known, and is believed to have a fundamental role in the regulation of blood flow. It is a peptide produced and secreted by endothelial cells in response to hypoxia and injury, as well as by macrophages. These properties suggest that ET-1 may play a role during tissue repair. In this study, we have examined the effects of ET-1 on the growth and synthetic activity of human dermal fibroblasts. ET-1 stimulated DNA synthesis in serum-deprived cultures: this effect reached a mean value of 64% more than control (P < 0.01) at 2.5 ng/ml (10-9, M) of ET-1. In contrast, the addition of ET-1 to fibroblasts at different densities and in 0, 3, or 10% fetal bovine serum (FBS) failed to increase cell counts. In 1% FBS, a 41% mean increase in cell counts compared to control values was observed in cultures treated with 2.5 ng/ml of ET-1 (P < 0.01). Incubation of dermal fibroblast cultures at 37°C for 1 hr with increasing concentrations of 125I-ET-1 resulted in saturable binding and a half-maximal specific binding of 27.5 pM. Scatchard plot analysis of the binding showed a Kd of 224 pM and 11,400 high-affinity binding sites per cell. ET-1 had no effect on [14C]-glucosamine incorporation by fibroblasts and caused no increase in collagen synthesis, as measured by collagenase-sensitive [3H]proline incorporation and by salt precipitation of 3H-labeled collagen at acid and neutral pH successively. In summary, ET-1 binds to fibroblasts through specific high-affinity surface receptors, but has no obvious direct effect on macromolecular synthesis. ET-1 stimulates [3H]thymidine uptake, but has marginal effects on cell growth. We conclude that any role of ET-1 in tissue repair is probably due to its hemodynamic effects and not as a growth factor.
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U2 - 10.1016/0022-4804(92)90099-L
DO - 10.1016/0022-4804(92)90099-L
M3 - Article
C2 - 1434602
AN - SCOPUS:0027099701
VL - 53
SP - 515
EP - 519
JO - Journal of Surgical Research
JF - Journal of Surgical Research
SN - 0022-4804
IS - 5
ER -