Effect of short term calorie restriction on pro-inflammatory NF-kB and AP-1 in aged rat kidney
Objective: To compare the effect of short-term calorie restriction (CR) on aging with that of already known long-term CR, the anti-inflammatory efficacy of 10-day CR was explored in aged rat kidney. Treatment: Two different age groups, 6 months (young) and 24 months (old) were used. In the old group, one sub-group was control, fed ad libitum (AL) and the other was fed CR for 10 days with 40 % of the food intake of the AL subgroup (n = 5). Methods: Reactive species (RS), lipid peroxides and COX-2 activity were measured. The activities of proinflammatory transcription factors NF-kB and AP-1 were measured by electro-mobility shift assay (EMSA). Upstream signaling cascades of NF-kB and AP-1 as well as proinflammatory gene expression were detected by Western blot. Results: 10-day CR suppressed RS, lipid peroxides, and COX-2 activity in aged rat kidney. CR also inhibited upstream signaling cascades and DNA binding activity of NF-kB and AP-1, and thioredoxin/Ref-1 pathway. CR blocked expression of NF-kB-and AP-1-responsive gene COX-2, iNOS, VCAM-1 and ICAM-1. Conclusions: We report for the first time that 10-day CR can attenuate the altered signaling transduction for inflammatory processes which is mediated through RS-induced NF-kB and AP-1 in aged kidney.