Pro-inflammatory activity of contaminating DNA in hyaluronic acid preparations.
Hyaluronic acid (HA), an abundant non-sulfated glycosaminoglycan component of the extracellular matrix, has applications in drug delivery, tissue engineering and as an ingredient in cosmetics. HA preparations containing high-molecular-weight polymers are also used in the treatment of inflammatory disorders such as arthritis and interstitial cystitis. Low-molecular-weight fragments derived from HA have been reported to induce pro-inflammatory cytokines such as IL-12 and TNF-alpha, and could therefore potentially exacerbate existing inflammation. We therefore examined the pro-inflammatory activity of HA preparations, since inflammatory reactions are known to occur following administration of HA. We tested low-molecular-weight fragments obtained from seven different HA preparations, either by sonication (approximately equals 3 x 10(5) Da) or by hyaluronidase digestion (approximately equals 1 x 10(4) Da), for the ability to induce the synthesis of IL-12 and TNF-alpha by human monocytic cells. We found that two of the seven HA preparations tested stimulated the synthesis of IL-12 and TNF-alpha by human monocytic cells. We unexpectedly found that the induction of IL-12 and TNF-alpha by these HA preparations was not due to their degradation to low-molecular-weight fragments, since their native high-molecular-weight forms possessed the same ability to stimulate IL-12 and TNF-alpha synthesis, but was due to the presence of contaminating DNA. Treatment of these two HA preparations with deoxyribonuclease I abrogated or reduced the induction of IL-12 and TNF-alpha. It is clear from this study that HA preparations can induce the synthesis of pro-inflammatory cytokines by monocytes. The ability of HA to act as a pro-inflammatory mediator may not, however, be related to the presence of low-molecular-weight HA fragments, but to the presence of DNA. The presence of pro-inflammatory DNA in HA preparations should be evaluated before its use, not only for the treatment of patients with inflammatory disorders, but also before many other applications.
Filion
M C
MC
Bioniche Therapeutics Research Center, Montréal, Québec, Canada.
Phillips
N C
NC
D000276:Adjuvants, Immunologic / Q000009:adverse effects*; D001168:Arthritis / Q000188:drug therapy; D018929:Cell Culture Techniques; D018856:Cystitis, Interstitial / Q000188:drug therapy; D004247:DNA; D004340:Drug Contamination; D004587:Electrophoresis, Agar Gel; D006801:Humans; D006820:Hyaluronic Acid / Q000009:adverse effects* / Q000276:immunology; D007249:Inflammation / Q000139:chemically induced*; D018664:Interleukin-12 / Q000096:biosynthesis; D008970:Molecular Weight; D009000:Monocytes / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D000276:Adjuvants, Immunologic; D014409:Tumor Necrosis Factor-alpha; D018664:Interleukin-12; D006820:Hyaluronic Acid; D004247:DNA