FIG. 1.

Effect of 8-Bromo cyclic adenosine 3′,5′-monophosphate (cAMP) and mouse embryonic stem cells (mESCs) on skin wound healing. Experimental animals were divided into four groups: vehicle group (n = 5), which received 60 μL of 1:1 mixture of DMEM and growth factor-reduced Matrigel (BD Biosciences), 8-Bromo cAMP group (n = 5), mESCs (n = 5), and 8-Bromo cAMP (10⁻⁵ M)-treated mESCs (n = 5). Vehicle, 8-Bromo cAMP, mESCs, or mESCs with 8-Bromo cAMP (mESCs + 8-Br) were applied onto the skin wound. (A) Representative wound appearance of 8-Bromo cAMP, mESCs, and 8-Bromo cAMP-treated mESCs at days 0, 1, 5, 7, 8, and 9. (B) Quantification of wound size relative to original wound size (day 0) is calculated. Data represent the mean ± SE (n = 5). *P < 0.05 versus control. ^#P < 0.05 versus 8-Bromo cAMP group. ^†P < 0.05 versus mESC group. (C) At day 9, after wounding, the skin samples were collected and sectioned using the Leica CM 1850 cryostat microtome. The tissue section slides were stained with hematoxylin and eosin (H&E) (n = 5), and representative images are shown. Scale bar = 200 μm. (D) Cutaneous blood vessel at day 9 postwounding was acquired. The dotted circle presents the wound site and the arrows reveal the branched angiogenic vessel. (E) mESCs were treated with 8-Bromo cAMP for 1 day, and the secreted cytokines/wound repair-related molecules into the medium and the expression of cytokines/wound repair-related molecules in mESCs were detected by immunoblot. Wound skin at day 9 postwounding was acquired, and the expression of cytokines/wound repair-related molecules was detected by immunoblot. The right panel of E depicted by bars denotes mean ± SE of three experiments for each condition determined by densitometry. *P < 0.05 versus control. ^#P < 0.05 versus vehicle. Ep, epidermis; D, dermis; H, hypodermis; CL, cornified layer; G, granulation tissue; WS, center of original wound site. Color images available online at www.liebertpub.com/scd