Impaired proliferation and increased L-lactate production of dermal fibroblasts in the GK-rat, a spontaneous model of non-insulin dependent diabetes mellitus.
Intact fibroblast function is required for normal wound healing. Although healing is generally accepted to be disturbed in non-insulin dependent diabetes mellitus, the signals modulating this disturbance are not fully understood. Therefore, we studied dermal fibroblasts from the GK rat, a non-insulin dependent diabetes mellitus model, and the Wistar rat (control) regarding growth characteristics, and L-lactate production at 5.5 mM and 25.5 mM glucose in the absence or presence of protein kinase C-inhibition, or alpha-tocopherol acetate. In addition, growth and L-lactate responses to hyaluronic acid were assessed under normal glucose conditions. At 5.5 mM glucose, the fibroblasts from the GK rat showed a lower proliferation rate during the first 24 hours, measured as DNA content, as compared to Wistar rats, i.e. at 8 hours GK was 57% of control, p < 0.01, at 24 hours GK was 60% of control, p < 0.01. The GK rat fibroblasts accumulated higher L-lactate levels in the media at 24-96 hours. Addition of glucose at a concentration of 25.5 mM decreased the total DNA content in GK rat fibroblast cultures to 74% (p < 0.05) and in control to 87% (p < 0.05), and increased L-lactate levels, measured at 48 hours. A protein kinase C-inhibitor, bisindolylmaleimide IX, increased DNA content and decreased L-lactate in both cell types during culture in high glucose, but only affected GK rat fibroblasts during normal glucose. Hyaluronic acid, increased DNA content in both types of fibroblasts, GK: 139% (p < 0.05), control: 127% (p < 0.05) and reduced L-lactate production. The above observations indicate that GK rat fibroblast proliferation is suppressed when the cells are cultured in high glucose containing media. In addition, protein kinase C and hyaluronic acid might play a role as modulators of fibroblast proliferation during the diabetic state.
Hehenberger
K
K
Department of Molecular Medicine, The Endocrine and Diabetes Unit, Karolinska Institute, Stockholm, Sweden. karin.hehenberger@molmed.ki.se
Hansson
A
A
Heilborn
J D
JD
Abdel-Halim
S M
SM
Ostensson
C G
CG
Brismar
K
K
D000276:Adjuvants, Immunologic / Q000494:pharmacology; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D018929:Cell Culture Techniques / Q000379:methods; D002455:Cell Division / Q000502:physiology*; D003470:Culture Media / Q000494:pharmacology; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism* / Q000503:physiopathology*; D004195:Disease Models, Animal; D005347:Fibroblasts / Q000378:metabolism* / Q000502:physiology*; D005947:Glucose / Q000494:pharmacology; D006820:Hyaluronic Acid / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D019344:Lactic Acid / Q000096:biosynthesis*; D008297:Male; D008301:Maleimides / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D051381:Rats; D011919:Rats, Inbred Strains; D017208:Rats, Wistar; D012867:Skin / Q000166:cytology*; D024505:Tocopherols; D014810:Vitamin E / Q000031:analogs & derivatives / Q000494:pharmacology; D014945:Wound Healing / Q000502:physiology*; D024502:alpha-Tocopherol / Q000031:analogs & derivatives*
D000276:Adjuvants, Immunologic; D000975:Antioxidants; D003470:Culture Media; D007211:Indoles; D008301:Maleimides; D014810:Vitamin E; D019344:Lactic Acid; D006820:Hyaluronic Acid; D011493:Protein Kinase C; D024502:alpha-Tocopherol; D005947:Glucose; C088060:bisindolylmaleimide; D024505:Tocopherols