TY - JOUR
T1 - Binding and Internalization of Hyaluronate by Human Cutaneous Fibroblasts
AU - Bertolami, Charles N.
AU - Berg, Steven
AU - Messadi, Diana V.
N1 - Funding Information:
This research was supported by granrs from the National Institutes of Health (National Institute of Dental Research) No. DEOn03 (C.N.B.), No. DE09178 (C.N.B.) and the Shriners Hospital for Crippled Children, No. 15957 (C. N. B.).
PY - 1992
Y1 - 1992
N2 - Hyaluronate is a ubiquitous component of mammalian extracellular matrix. It influences numerous cellular processes and accumulates in fibrotic connective tissue disorders. Recently, hyaluronate catabolism has assumed additional importance because of the introduction into clinical practice of therapeutic procedures which deposit high concentrations of hyaluronate directly into tissues. Relatively little is known about the local metabolism, fate, or long-term effects of either endogenous or exogenous hyaluronate at deposition sites. A capacity for degrading hyaluronate within connective tissues, presumably by fibroblasts, has been inferred but remains controversial because direct proof that human fibroblasts endocytose and degrade hyaluronate has been lacking. In the present study, fibroblasts from normal and fibrotic skin were incubated with [3H]-hyaluronate. Binding and internalization of radiolabeled substrate were then measured: Binding assays revealed a saturable, dose-dependent increase in cell surface-associated [3H]-hyaluronate which was enhanced by pretreatment with hyaluronidase. Similar binding curves were obtained for all cells tested. All the cell lines internalized hyaluronate; however, fibroblasts in confluent cultures internalized 3.5- to 4.2-fold more radioactivity per cell than did fibroblasts from corresponding subconfluent cultures (p ≤ 0.002). Normal scar fibroblasts showed greater capacity for generating hyaluronate-derived partial degradation products. This work provides clear evidence that human cutaneous fibroblasts are capable of both binding and internalizing hyaluronate, possibly as a prerequisite for degradation.
AB - Hyaluronate is a ubiquitous component of mammalian extracellular matrix. It influences numerous cellular processes and accumulates in fibrotic connective tissue disorders. Recently, hyaluronate catabolism has assumed additional importance because of the introduction into clinical practice of therapeutic procedures which deposit high concentrations of hyaluronate directly into tissues. Relatively little is known about the local metabolism, fate, or long-term effects of either endogenous or exogenous hyaluronate at deposition sites. A capacity for degrading hyaluronate within connective tissues, presumably by fibroblasts, has been inferred but remains controversial because direct proof that human fibroblasts endocytose and degrade hyaluronate has been lacking. In the present study, fibroblasts from normal and fibrotic skin were incubated with [3H]-hyaluronate. Binding and internalization of radiolabeled substrate were then measured: Binding assays revealed a saturable, dose-dependent increase in cell surface-associated [3H]-hyaluronate which was enhanced by pretreatment with hyaluronidase. Similar binding curves were obtained for all cells tested. All the cell lines internalized hyaluronate; however, fibroblasts in confluent cultures internalized 3.5- to 4.2-fold more radioactivity per cell than did fibroblasts from corresponding subconfluent cultures (p ≤ 0.002). Normal scar fibroblasts showed greater capacity for generating hyaluronate-derived partial degradation products. This work provides clear evidence that human cutaneous fibroblasts are capable of both binding and internalizing hyaluronate, possibly as a prerequisite for degradation.
KW - endocytosis
KW - fibroblasts
KW - fibrosis
KW - hyaluronate
KW - scar
KW - skin
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U2 - 10.1016/S0934-8832(11)80100-9
DO - 10.1016/S0934-8832(11)80100-9
M3 - Article
C2 - 1560786
AN - SCOPUS:0026527337
VL - 12
SP - 11
EP - 21
JO - Collagen and Related Research
JF - Collagen and Related Research
SN - 0945-053X
IS - 1
ER -