Comparison of mRNA contents of interleukin-1 beta and nitric oxide synthase in pancreatic islets isolated from female and male nonobese diabetic mice.
Interleukin-1 beta (IL-1 beta) has been suggested to mediate beta-cell destruction in insulin-dependent diabetes mellitus (IDDM) by inducing nitric oxide production. In this study, we assessed the levels of IL-1 beta and the inducible form of nitric oxide synthase (iNOS), using a semi-quantitative polymerase chain reaction assay, and performed determinations of nitrite accumulation and IL-1 beta bioactivity, on pancreatic islets isolated from 5- and 16-week-old female and male nonobese diabetic (NOD) mice and from nondiabetes prone NMRI mice. NOD mouse islets contained notable amounts of IL-1 beta mRNA. At 5 weeks of age, but not at 16 weeks, the values were higher in islets isolated from NOD females compared to males. The IL-1 beta bioactivity showed differences roughly reflecting the mRNA levels in the NOD mouse islets. In the NMRI mouse islets the IL-1 beta bioactivity was very low. The expression of iNOS mRNA increased in both male and female islets between 5 and 16 weeks of age. Immunocytochemistry of pancreatic sections indicated the presence of macrophages especially in the peri-insular area of the NOD mice which suggests that IL-1 beta was produced by macrophages. The levels of IL-1 beta activity and mRNA in freshly isolated islets from NOD 5-weeks-old females did not correlate to the iNOS mRNA content or to the nitrite production. However, after incubation with IL-1 beta in vitro, both NOD and NMRI islets responded with a marked increase in nitric oxide production.(ABSTRACT TRUNCATED AT 250 WORDS)
Welsh
M
M
Department of Medical Cell Biology, Uppsala University, Sweden.
Welsh
N
N
Bendtzen
K
K
Mares
J
J
Strandell
E
E
Oberg
C
C
Sandler
S
S
D000594:Amino Acid Oxidoreductases / Q000032:analysis* / Q000235:genetics; D000818:Animals; D001483:Base Sequence; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism*; D005260:Female; D015870:Gene Expression; D007375:Interleukin-1 / Q000032:analysis* / Q000235:genetics; D007515:Islets of Langerhans / Q000737:chemistry* / Q000473:pathology; D008297:Male; D051379:Mice; D016688:Mice, Inbred NOD; D008969:Molecular Sequence Data; D009569:Nitric Oxide / Q000032:analysis; D019001:Nitric Oxide Synthase; D012333:RNA, Messenger / Q000032:analysis*
D007375:Interleukin-1; D012333:RNA, Messenger; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases