Effects of periodontitis on aortic insulin resistance in an obese rat model

Abstract

The combination of obesity and its associated risk factors, such as insulin resistance and inflammation, results in the development of atherosclerosis. However, the effects of periodontitis on atherosclerosis in an obese body remain unclear. The aim of the study was to investigate the effects of ligature-induced periodontitis in Zucker fatty rats on initiation of atherosclerosis by evaluating aortic insulin resistance. Zucker fatty rats (n ¼ 24) were divided into two groups. In the periodontitis group, periodontitis was ligature-induced for 4 weeks, whereas the control group was left unligated. After the 4-week experimental period, descending aorta was used for measuring the levels of lipid deposits, immunohistochemical analysis, and evaluation of gene expression. Levels of serum C-reactive protein (CRP), tumor necrosis factora (TNF-a), and insulin were also measured. Rats in the periodontitis group had significantly enhanced lipid deposits in the aorta, but not in the control group. Expression of suppressor of cytokine signaling 3, vascular cell adhesion molecule 1, reactive oxygen species, nitrotyrosine, and endothelin-1 in the periodontitis group was more intense than that in the control group. Significantly decreased levels of phosphatidylinositol 3-kinase (Pi3k) catalytic b-polypeptide (Pi3kcb), Pi3kp85, and insulin receptor substrate 1 and 2 were observed in the periodontitis group. Levels of serum CRP and TNF-a were significantly increased in the periodontitis group. Under insulin-stimulated conditions, aorta in the periodontitis group altered the Akt phosphorylation. Periodontitis in obesity induced the initial stage of atherosclerosis and disturbed aortic insulin signaling.

Occlusal disharmony accelerates the initiation of atherosclerosis in apoE knockout rats

“…Amplification conditions were as follows: 45 cycles at 95°C (5 s), 65°C (5 s) and 72°C (8 s) for VCAM1; and 45 cycles at 95°C (15 s), 59°C (20 s) and 72°C (20 s) for TLR4 . Primer sequences were VCAM1 , 5′-GGCTCGTACACCATCCGC-3′ and 5′-CGGTTTTCGATTCACACTCGT-3′ [32], and TLR4 , 5′-GTGAGCATTGATGAGTTCAG-3′ and 5′-CATCTAATGATTGATAAGGATT-3′ [29]. Primers used to detect the internal control, β-actin, were 5′-TGTTGCCCTAGACTTCGAGCA-3′ and 5′-GGACCCAGGAAGGAAGGCT-3′ [29].…”

Occlusal Disharmony Increases Amyloid-β in the Rat Hippocampus

“…The isolated RNA was quantified by measurement of the absorbance at 260 nm, and its purity was determined by the 260/280 nm absorbance ratio. Samples with a ratio[1.8 were used in the procedure described below Ekuni et al 2010). Total RNA (2 lg) was reverse transcribed by AMV reverse transcriptase (TAKARA, Shiga, Japan) at 42°C for 30 min.…”

Increased Lipid Accumulation in Liver and White Adipose Tissue in Aging in the SAMP10 Mouse

“…The adjusted intensity equals the intensity of each gene minus the background value. The normalized intensity to the Gapdh gene was calculated by the following formula: normalized intensity ϭ ( X Ϫ Z )/( Y Ϫ Z ) ϫ 1,000, where X is the adjusted intensity of target gene, Y is the adjusted intensity of the Gapdh gene, and Z is the median of adjusted intensities of six negative controls ( 21 ). In this DNA microarray analysis, the 3MO group was compared with 6, 9 and 12MO groups ( 17 , 22 , 23 ).…”