Diabetic Lactoferrin Deficient Mice Demonstrates Greater Susceptibility to Experimental Periodontal Disease

Abstract

The objective of this study is to detrmine whether alloxan-induced diabetic Lactoferrin knockout (LFKO^-/-) mice are more susceptible to periodontal disease caused by Aggregatibacter actinomycetemcomitans compared to the diabetic wild-type (WT) mice. Diabetes was induced in mice by a single dose of alloxan (60 mg/kg) injected intravenously. Mice were categorized as diabetic when blood glucose levels >250 mg/dL were measured on the 7^th day after the injection. Periodontal disease was experimentally induced by A. actinomycetemcomitans infection in alloxan induced diabetic WT and LFKO^-/- mice. Fasting blood glucose levels and body weight were monitored throughout the study. At the end of the 12^th week of infection, mice were sacrificed and bone loss among the groups was estimated by measuring the distance between cemento-enamel junction (CEJ) to the alveolar bone crest (ABC) at 12 sites on the molars. A. actinomycetemcomitans infected mice groups developed more alveolar bone loss than sham-infected animals. Diabetic LFKO^-/- infected mice exhibited significant bone loss (P<0.01) and a higher mean fasting blood glucose level (P<0.05) when compared to diabetic WT infected mice. No statistically significant difference in fasting blood glucose level was found between the infected and sham-infected groups. Peripheral blood analysis at the end of the 12^th week revealed a significant reduction in the platelet counts in LFKO^-/- mice when compared to WT mice. Furthermore, diabetic LFKO^-/- presented with lower counts than non-diabetic LFKO^-/- mice (P<0.01). In conclusion, diabetic lactoferrin deficient mice are at a higher risk of developing periodontal infection induced by A. actinomycetemcomitans when compared to diabetic WTI mice.

Keywords: Aggregatibacter actinomycetemcomitans; Diabetes; Lactoferrin; Lactoferrin knockout mice; Periodontal disease.

Figure 1. Representative gel picture of detection of A. actinomycetemcomitans DNA from the oral cavity of infected diabetic and non-diabetic mice after 12 weeks of post infection

A. actinomycetemcomitans DNA was detected by PCR using A. actinomycetemcomitans LtxA-specific primers. Genomic DNA extracted from A. actinomycetemcomitans was also subjected to PCR as a positive control. 1) Positive control and 2–6) A. actinomycetemcomitans DNA from infected mice.

Figure 2. A. actinomycetemcomitans-induced alveolar bone loss was evaluated with or without diabetes in WT and LFKO^−/− mice 12 weeks after infection or sham infection

Digital images at 10× magnification of defleshed and Methylene blue stained maxillary jaws from all the mice groups.