Hyaluronan oligosaccharides stimulate matrix metalloproteinase and anabolic gene expression in vitro by intervertebral disc cells and annular repair in vivo.
The role of hyaluronan (HA) oligosaccharides in disc cell-mediated matrix metalloproteinase (MMP) and anabolic gene expression in vitro and annular repair in vivo were examined. Monolayer and alginate bead cultures of ovine intervertebral disc cells were stimulated with 10-12 mer hyaluronan oligosaccharides (HA-oligos). Annulus fibrosus (AF) monolayers were poorly responsive to the HA-oligos, proMMP-2 levels were marginally elevated and levels were MMP-9 unaffected. ProMMP-2 displayed a strong dose-dependent increase in the nucleus pulposus (NP) monolayers. In AF alginate bead cultures, proMMP-2 and active MMP-9 increased up to day 10, in NP cultures proMMP-2 was progressively converted to active MMP-2 over days 7-10 and active MMP-9 levels were elevated on day 10. A steady decline in MMP-2 and MMP-9 activity was evident over days 2-10 in the non-stimulated NP cultures. Disc cell viabilities were ≥92 ± 5% in all cultures indicating that the HA-oligo was not cytotoxic. Reverse-transcription polymerase chain reaction demonstrated an upregulation in MMP1, MMP113 and ADAMTS1 and the anabolic matrix repair genes ACAN, COL1A1 and COL2A1 in the NP by HA-oligos, whereas AF MMP13, ADAMTS1, ADAMTS4 and ADAMTS5, ACAN and COL2A1 were down-regulated; this differential regulation is expected to promote clearance of granulation/scar tissue from AF defects and matrix replenishment. The AF defect sites contained enlarged annular lamellae in vivo in response to the HA oligos, which is consistent with an active repair response. Masson trichrome and PicroSirius red histology and immunolocalization of type I collagen supported active remodelling in the outer lesion zone by the HA-oligo treatment but not the inner lesion. Copyright © 2016 John Wiley & Sons, Ltd.
Raymond Purves Bone and Joint Research Laboratory, Kolling Institute Northern Sydney Local Health District, St Leonards, NSW, Australia.
Emily S
ES
Fuller
Raymond Purves Bone and Joint Research Laboratory, Kolling Institute Northern Sydney Local Health District, St Leonards, NSW, Australia.
Cindy
C
Shu
Raymond Purves Bone and Joint Research Laboratory, Kolling Institute Northern Sydney Local Health District, St Leonards, NSW, Australia.
Margaret M
MM
Smith
Raymond Purves Bone and Joint Research Laboratory, Kolling Institute Northern Sydney Local Health District, St Leonards, NSW, Australia.|Sydney Medical School, Northern, The University of Sydney, Royal North Shore Hospital, Sydney, Australia.
Christopher B
CB
Little
Raymond Purves Bone and Joint Research Laboratory, Kolling Institute Northern Sydney Local Health District, St Leonards, NSW, Australia.|Sydney Medical School, Northern, The University of Sydney, Royal North Shore Hospital, Sydney, Australia.|Graduate School of Biomedical Engineering, University of New South Wales, Kensington, NSW, Australia.
James
J
Melrose
D000818:Animals; D000070616:Annulus Fibrosus / Q000473:pathology*; D005780:Gelatin / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects*; D006820:Hyaluronic Acid / Q000494:pharmacology*; D020782:Matrix Metalloproteinases / Q000378:metabolism*; D009844:Oligosaccharides / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012756:Sheep; D014945:Wound Healing / Q000187:drug effects*
D009844:Oligosaccharides; D012333:RNA, Messenger; D005780:Gelatin; D006820:Hyaluronic Acid; D020782:Matrix Metalloproteinases
anabolic matrix genes; annular remodelling; hyaluronan oligosaccharide; intervertebral disc repair