631-P: Negative Pressure Wound Therapy May Affect Circulating Plasma MicroRNAs in Patients with Diabetic Foot Ulceration

Abstract

Background: Negative pressure wound therapy (NPWT) has been successfully used as treatment for diabetic foot ulceration (DFU). However, the molecular mechanisms of its action, especially outside of the wound bed, are not fully understood. We assessed the effect of NPWT on levels of circulating plasma microRNAs in patients with type 2 diabetes (T2DM) and DFU. Methods: We included 33 patients with T2DM and DFU - 23 individuals were assigned to NPWT and 10 to standard treatment (ST). Assignment to NWPT was based on routine clinical recommendations and not random. MicroRNAs enriched RNA was extracted from plasma at two time points: before treatment and after 8±1 days of treatment. Prepared small RNA libraries were sequenced on the NextSeq 500 sequencer (Illumina). Generated reads were aligned to mirBase 21 using Bowtie and counted using miRDeep2 software. Statistical analysis of differentially expressed microRNAs was performed via the edgeR package in the R environment. Results: The NPWT and ST groups were similar in terms of basic clinical characteristics, such as age (67.8 vs. 67.8 years, p=0.95) and HbA1c level (7% vs. 7.8%, p=0.15). We identified three miRNAs - miR-6842, miR-3690 and miR-11400 - that were expressed at a higher level post-treatment in the NPWT group as compared to the ST group. Interestingly, miR-3690 has been previously predicted to target mRNA of T-cell surface glycoprotein CD3 gamma chain (CD3G), therefore, it may be hypothesized that it affects the expression of CD3 and modulate the immune response. Additionally, in the NPWT group we observed a downregulation of miR-9 as compared to the initial level. MiR-9 is expressed in human monocytes and neutrophils upon activation. Thus, it may regulate the synthesis of proinflammatory mediators. Conclusions: We found initial evidence that short-term NPWT use in T2DM patients with DFU may affect miRNA expression in plasma and act through promoting immune system factors in the wound bed. Disclosure P. Kapusta: None. J. Hohendorff: Other Relationship; Self; Abbott, Ascensia Diabetes Care, Novo Nordisk A/S, Sanofi-Aventis. J. Zuranska: None. S. Borys: None. P. Konieczny: None. B.M. Kiec-Wilk: None. P.P. Wolkow: None. M. Malecki: Advisory Panel; Self; Abbott Laboratories, AstraZeneca, Bioton, Boehringer Ingelheim Pharmaceuticals, Inc., Lilly Diabetes, Merck Sharp & Dohme Corp., Novartis Pharmaceuticals Corporation, Novo Nordisk Inc., Sanofi-Aventis. Speaker's Bureau; Self; Merck & Co., Inc. Funding National Science Centre of Poland (2013/11/B/NZ5/03298)