Insulin treatment prevents wounding associated changes in tissue and circulating neutrophil MMP-9 and NGAL in diabetic rats.
Neutrophils are important for wound repair, but their persistence can impair the healing process. Neutrophils express matrix metalloproteinases including MMP-9 and its regulator neutrophil gelatinase associated lipocalin (NGAL). Whether wounding affects neutrophil MMP-9 and NGAL in diabetic animals is not known. Skin wound tissue MMP-9 and NGAL was examined by qRT-PCR and immunohistochemistry in control, diabetic and insulin treated diabetic rats. The temporal expression of MMP-9 and NGAL mRNA, MMP-9 activity and the NGAL/MMP-9 complex was also investigated in an implant model and their circulating neutrophils. The cellular localisation of MMP-9 and NGAL was confirmed by immunofluorescence and the ability of glucose to regulate these factors was examined in isolated neutrophils. In skin wound tissue compared with control, diabetes increased neutrophil infiltration, NGAL mRNA and MMP-9 protein (P<0.05). Diabetes significantly increased implant neutrophil NGAL and MMP-9 protein as well as NGAL mRNA, wound fluid NGAL/MMP-9 complex and MMP-9 activity (all <0.05). Circulating neutrophil MMP-9 and NGAL was also increased in these diabetic animals (P<0.05). These changes were prevented by insulin treatment. Ex vivo, high glucose (25mM) increased neutrophil NGAL and MMP-9 (both by 2 fold, P<0.05). NGAL and MMP-9 are increased in wound and circulating neutrophils in diabetic rodents. These changes and the association between higher NGAL and increased wound fluid MMP-9 activity suggest that increased neutrophil NGAL may contribute to increased MMP-9 in poorly healing diabetic wounds. Whether targeting neutrophil NGAL or MMP-9 can improve diabetic wound healing remains to be investigated.
Greg Brown Diabetes and Endocrinology Laboratories, Sydney Medical School, Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia.
Maryam
M
Abdollahi
Greg Brown Diabetes and Endocrinology Laboratories, Sydney Medical School, Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia.
Taria Shin Yi
TS
Ng
Greg Brown Diabetes and Endocrinology Laboratories, Sydney Medical School, Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia.
Alireza
A
Rezaeizadeh
Greg Brown Diabetes and Endocrinology Laboratories, Sydney Medical School, Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia.
Sarah
S
Aamidor
Greg Brown Diabetes and Endocrinology Laboratories, Sydney Medical School, Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia.|Department of Endocrinology and Diabetes Centre, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia.
Stephen M
SM
Twigg
Greg Brown Diabetes and Endocrinology Laboratories, Sydney Medical School, Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia.|Department of Endocrinology and Diabetes Centre, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia.
Danqing
D
Min
Greg Brown Diabetes and Endocrinology Laboratories, Sydney Medical School, Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia.|Department of Endocrinology and Diabetes Centre, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia.|Chemical Pathology, Royal Prince Alfred Hospital, NSW Health Pathology, Sydney, New South Wales, Australia.
Susan V
SV
McLennan
D000209:Acute-Phase Proteins / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D048909:Diabetes Complications / Q000188:drug therapy* / Q000378:metabolism; D007328:Insulin / Q000494:pharmacology / Q000627:therapeutic use*; D000071068:Lipocalin-2; D054834:Lipocalins / Q000235:genetics / Q000378:metabolism*; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism*; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012867:Skin / Q000187:drug effects / Q000293:injuries* / Q000378:metabolism; D014945:Wound Healing
D000209:Acute-Phase Proteins; D007328:Insulin; C097278:Lcn2 protein, rat; D000071068:Lipocalin-2; D054834:Lipocalins; D011518:Proto-Oncogene Proteins; D020780:Matrix Metalloproteinase 9; C572337:Mmp9 protein, rat