Autophagy-related protein expressions in wound granulation tissues from diabetic foot patients infected with Pseudomonas aeruginosa

Objective To observe LC3 and Beclin-1 protein expressions in granulation tissues of diabetic foot(DF)patients infected with Pseudomonas aeruginosa(PA), and to explore the relationship between the multi-drug resistance of pseudomonas aeruginosa and autophagy-related protein expressions in diabetes mellitus. Methods Thirty-one DF inpatients infected with PA in Tianjin Metabolic Diseases Hospital from April 2015 to March 2016 were enrolled(DF group)and 19 inpatients with foot burn infected with PA in Tianjin Armed Police Hospital at the same period were enrolled as non-diabetic control group(CON). Immunohistochemistry was used to determine the expressions of LC3 and Beclin-1 in wound granulation tissues taken from these patients. The expression of LC3 in macrophages was detected by an immunofluorescence double staining method. Results Compared with CON group, the expressions of LC3 and Beclin-1 in DF group were significantly decreased(1.75±0.36 vs 2.44±0.33, 0.75±0.22 vs 1.46±0.21, both P<0.01), and the expression of LC3 in macrophages were also decreased. Compared with CON group, higher percentage of the detection rate of multi-drug resistant pseudomonas aeruginosa(MDRPA)was found in DF group(48.4% vs 5.3%, P<0.01). In DF group, LC3 and Beclin-1 expressions in granulation tissues of MDRPA group were lower than those of Non-MDRPA group(1.62±0.08 vs 1.91±0.13, 0.62±0.11 vs 0.89±0.14, both P<0.01). Conclusions The LC3 and Beclin-1 expressions in wound granulation tissues of DF patients infected with PA are decreased compared with control patients, especially in DF patients infected with MDRPA. The multi-drug resistance of pseudomonas aeruginosa in diabetic foot infection is related to reduced autophagy-related protein expression levels. (Chin J Endocrinol Metab, 2017, 33: 23-28) Key words: Diabetic foot; Infection; Autophagy; Multi-drug resistant pseudomonas aeruginosa; Macrophages