[EFFECT OF α-LIPOIC ACID IN INHIBITING OXIDATIVE STRESS AND PROMOTING DIABETIC WOUND HEALING BY SUPPRESSING EXPRESSION OF miR-29b IN MICE].

Objective: To investigate the effect of α-lipoic acid on the oxidative stress of wound tissues and diabetic wound healing in mice with diabetic feet.

Methods: Sixty male C57BL/6J mice weighting 200-300 g were randomly divided into model group (control group, =15), α-lipoic acid-treated model group (=15), miR-29b mimic group (=15), and miR-29b mimic negative control group (NC group, =15). All animals received intraperitoneal injection of streptozocin to establish the diabetic model. Then, a full thickness wound of 5 mm×2 mm in size was created at 4 weeks after modeling. All mice were administrated with high-sugar-fat-diet. At the same day after modeling, α-lipoic acid-treated model group was continuously given intravenous injection of 100 mg/(kg·d) α-lipoic acid for 14 days; miR-29b mimic group and NC group received the tail intravenous injection of lentiviral vector for miR-29b mimic and miR-29b mimic negative control (a total of 2×10 TU), respectively, with the treatment of α-lipoic acid. The wound healing was observed and wound area was measured at 7 and 14 days. The wound tissues were harvested to detect the levels of superoxide dismutase (SOD) and glutathione (GSH) using xanthine oxidase method and 5, 5-dithiobis-2-nitrobenzoic acid staining method at 14 days. At the same day, 7, and 14 days after modeling, the relative miR-29b expression in wound tissues from control and α-lipoic acid-treated model groups was detected by real-time fluorescence quantitative PCR.

Results: All mice survived to the experiment end. The wound healing was faster in α-lipoic acid-treated group than control group. At 7 and 14 days, the relative wound area and miR-29b expression level were significantly lower, while the contents of SOD and GSH were significantly higher in α-lipoic acid-treated group than control group (<0.05). In addition, miR-29b mimic group had significantly increased relative wound area and significantly decreased the contents of SOD and GSH when compared with NC group at 7 and 14 days (<0.05).

Conclusions: α-lipoic acid could inhibit oxidative stress and promote diabetic wound healing by suppressing expression of miR-29b in mice.