ISSN:
1365-2133
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Background In human skin, inducible nitric oxide synthase (iNOS) appears to be a key enzyme during wound healing and has roles in protection from infection. We speculated that diabetic skin complications such as delayed wound healing and skin infection were due to iNOS activity altered by high glucose in skin keratinocytes.Objectives The purpose of this study was to see how high levels of glucose affect iNOS activity in the human keratinocyte cell line (HaCaT).Methods HaCaT cells were exposed to high glucose for 1 day or 10 days. We measured nitric oxide (NO) end product nitrite in the culture medium using the Griess reagent, and intracellular tetrahydrobiopterin (BH4, a cofactor of NOS) content by using high-performance liquid chromatography, analysed the expression level of iNOS mRNA by the reverse transcriptase-polymerase chain reaction method and evaluated the DNA binding activity of nuclear factor kappa B (NF-κB) by enzyme-immunoassay.Results Short-term exposure (1 day) to a high level of glucose increased BH4 and iNOS activity at the post-translational level. However, long-term exposure (10 days) to high glucose downregulates NF-κB binding activity and inhibits iNOS transcription and its activity.Conclusions Pretreatment with high glucose for 10 days down-regulated NF-κB activity and inhibited iNOS transcription and NO production, implying the involvement of a deficiency in NO synthesis in both skin infection and impaired wound healing in diabetic patients.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.0007-0963.2004.05867.x
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