PMC

The application of DETCs improved wound repair in diabetic mice compared with vehicle controls. Wild-type C57BL/6J mice were administered daily injections of STZ or vehicle control for 6 days, and received full-thickness wounds in their back skin at 4 weeks after STZ treatment. The application of DETCs to the wounds promoted wound healing. Mice were injected intra-dermally with 10⁶ DETCs or buffer control after wounding, and wound closure was measured over time. *p < 0.05 and **p < 0.005 vs vehicle control (two-tailed, unpaired Student’s t-test).

Diabetic wound healing conditions were improved by the application of DETCs. A. DETC application promoted the expression of IGF-1, KGF and PCNA in the epidermis around wound in diabetic mice. On day 4 after wounding, the epidermis around the wounds of STZ-induced diabetic mice was obtained to detect the expression of IGF-1, KGF and PCNA by Western blot. B. DETC application inhibited the apoptosis of epidermal cells around the wound in diabetic mice. Epidermal cells were stained with annexin V and propidium iodide (PI) to assess apoptosis and analyzed by flow cytometry. *p < 0.05 and **p < 0.005 vs vehicle control (two-tailed, unpaired Student’s t-test).

Reduced DETCs around a wound resulted in the weakened production of IGF-1 and KGF in the epidermis of diabetic mice. Wild-type C57BL/6J mice were administered daily i.p. injections of STZ or vehicle control for 6 days, and received full-thickness wounds in their back skin 4 weeks after STZ treatment. A. Reduced expression of IGF-1 and KGF in the epidermis around the wound of diabetic mice. On day 1 after wounding, the epidermis around wound of STZ-induced diabetic or control mice was obtained to detect the protein expression of IGF-1 and KGF by Western blot. B. Diabetic mice displayed significantly fewer DETCs in the intact epidermis and wounded epidermis compared with wild-type controls. DETCs numbers were increased upon wounding in wild-type controls compared with diabetic mice. The epidermis in the intact skin and around the wound at day 1 after wounding of STZ-induced diabetic or control mice were obtained to examine the number of DETCs by using FACS. *p < 0.05 and **p < 0.005 vs vehicle control (two-tailed, unpaired Student’s t-test).

DETCs reversed the negative effects of diabetes-like environments on keratinocytes. Keratinocytes were isolated from newborn C57 wild-type mice and cultured in the presence and absence of DETCs. A. The proliferation of keratinocytes under diabetes-like microenvironments was enhanced in the presence of DETCs after 3 days of cultivation. The cells were obtained to detect the expression of PCNA by western blot. B. The apoptosis of keratinocytes in diabetes-like microenvironments was reduced in the presence of DETCs after 3 days of cultivation. Keratinocytes were stained with annexin V and propidium iodide (PI) to assess apoptosis and analyzed by flow cytometry. C. DETCs enhanced the migration of keratinocytes in diabetes-like microenvironments. An in vitro scratch wound assay was used to assess the cell mobility in diabetes-like environments in the presence or absence of DETCs. *p < 0.05 and **p < 0.005 vs vehicle control (two-tailed, unpaired Student’s t-test).