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Hyaluronidase expression in human skin fibroblasts
S Stair-Nawy1, A B Csóka, R Stern
1School of Public Health, Department of Environmental Health Sciences, University of California, Berkeley, CA 94720, USA.
Biochemical and Biophysical Research Communications
|December 3, 1999
Summary
Hyaluronidase activity, previously thought absent, is now detected in human fibroblasts. This enzyme
Area of Science:
- Biochemistry
- Cell Biology
Background:
- Hyaluronidase is an enzyme that degrades hyaluronic acid.
- Previous studies suggested fibroblasts lack hyaluronidase activity.
Purpose of the Study:
- To investigate the presence and characteristics of hyaluronidase activity in human fibroblasts.
- To re-evaluate previous conclusions regarding fibroblast hyaluronidase.
Main Methods:
- Cell culture of human dermal fibroblasts (HS27), fetal fibroblasts (FF24), and fibrosarcoma cells (HT1080).
- Measurement of secreted and cell-associated hyaluronidase activity.
- Enzyme characterization including pH optimum and molecular size determination via zymography.
- Immunoprecipitation and PCR to identify the specific hyaluronidase isoform.
Main Results:
- Hyaluronidase activity was detected in HS27, FF24, and HT1080 cells, primarily secreted into culture media.
- Fibroblast hyaluronidase expression was confluence-dependent, peaking in quiescent cells, unlike fibrosarcoma cells.
- The enzyme exhibited a pH optimum of 3.7 and a molecular size of approximately 57 kDa.
- Immunoprecipitation and PCR confirmed the enzyme is identical to Hyal-1, human plasma hyaluronidase.
Conclusions:
- Human fibroblasts possess and secrete active hyaluronidase, identified as Hyal-1.
- The expression of fibroblast hyaluronidase is regulated by cell confluence.
- Previous assumptions about the absence of hyaluronidase in fibroblasts require revision based on these findings.