Interleukin 1 enhances synovial cell hyaluronate synthesis

Area of Science:

• Immunology
• Cell Biology
• Biochemistry

Background:

• Interleukin 1 (IL-1) is known to promote thymocyte proliferation and stimulate the release of prostaglandins and neutral proteases.
• A previously identified factor from human synovial membrane cells was found to be identical to monocyte-derived IL-1.

Purpose of the Study:

• To investigate the effect of IL-1 on hyaluronate synthesis by human synovial membrane cells.
• To determine if IL-1 from different sources impacts hyaluronate production.

Main Methods:

• Synovial membrane cells were cultured, and the effects of IL-1 on hyaluronate synthesis were measured.
• Gel filtration and isoelectric focusing were used to analyze the properties of the hyaluronate-stimulatory factor.
• Comparison of IL-1 activity from synovial cells and monocytes.

Main Results:

• Interleukin 1, regardless of its source (synovial cells or monocytes), significantly stimulates hyaluronate synthesis in synovial membrane cells.
• The hyaluronate-stimulatory activity was found to co-fractionate with IL-1 activity during purification.
• This represents a newly identified metabolic effect of IL-1.

Conclusions:

• Interleukin 1 plays a direct role in enhancing hyaluronate synthesis by synovial membrane cells.
• The findings establish a novel function for IL-1 in regulating extracellular matrix production in synovial tissues.