| Background and objective Endostatin(ES),as the most important angiogenesis inhibitor,has been widely used in anti-tumor angiogenesis therapy. Previous study showed that ES can inhibit scar hyperplasia,but it lack of the experimental report about the effect of local application of ES on wound healing and whether protein kinase C(PKC)-alpha involved in this process at present. This study is to investigate the roles of PKC-alpha in the process of angiogenesis of ES on wound healing.Materials and methods Thirty-six adult, healthy New Zealand white rabbits had been chosed weighing from2.0to2.5kg,without thinking of sex. Each rabbit was housed in a separate cage and was feeded for one week. After anesthetization with sodium pentobarbital through the auricular vein (1.Oml/kg body weight),four standardized full-thickness skin wounds of10.0mm in diameter extending to the cartilage were made on the ventral side of each rabbit ear. All the rabbits were randomly divided in to the Rh-ES treated group(10μg/ml), the PMA treated-group(10nM),the Go6983treated-group(1nM), the Rh-ES+PMA treated-group(10μg/ml+10nM),the Rh-ES+Go6983treated-group(10μg/ml+1nM) and the control group (PBS treatment). On the3rd,7th,11th post-wound day (PWDs) and epithelization(12th-16th PWDs),the wound healing rate and wound healing time were recorded and the wounds tissues were collected.The microvessel density(MVD) of wound tissues was counted according to the result of CD34immunohistochemistry and the expressions of PKC-alpha were determined.The data,expressed with(x±s), were assessed by the analysis of variance when homogeneity of variance among groups was satisfied, otherwise by the Kruskal-Wallis Test,and their further multiple comparison by LSD(least significant different) method. Data were analyzed using SPSS17.0for Windows, p<0.05was considered statistically significant.Results1. The wound healing time:There was significant differences in wound healing time among6groups (F=9.241, P=0.000).The wound healing time of Rh-ES-treated group(14.33±1.15)d, Go6983treated-group (14.58±1.24)d, Rh-ES+Go6983treated-group(15.08±1.08)d were longer than control group[(13.36±1.21)d, P＜0.05], while PMA treated-group(12.36±0.67)d was shorter(P＜0.05). The wound healing time of Rh-ES+PMA treated-group(13.45±1.13)d had no difference compared with control group(P>0.05).The wound healing time of Rh-ES+Go6983treated-group were longerer than Rh-ES treated-group(P<0.05),while Rh-ES+PMA treated-group was shorter (P＜0.05).2. The wound healing rate:The wound healing rate of Rh-ES+Go6983treated-group was lower than PMA treated-group and control group(P＜0.05), and other groups’ wound healing rates had no different on3rd PSDs(P>0.05).Compared with control group, the wound healing rate of Rh-ES treated group,Go6983treated-group, Rh-ES+Go6983treated-group were decreased signifieantly on the7th and11th PWDs (P＜0.05),but there was no difference between the any of two out of three groups(P＞0.05);While the wound healing rate of PMA treated-group was inereased significantly compared with other groups(P＜0.05). And the wound healing rate had no difference between Rh-ES+PMA treated-group and control group in any PWDs(P＞0.05).3. Microvessel density (MVD):The MVD of Rh-ES+Go6983treated-group was lower than control group(P＜0.05), and other groups had no difference compared with control group on3rd PSDs(P＞0.05). Since the7th PWDs, the MVD of Rh-ES treated group and Go6983treated-group were lower than control group (P＜0.05),while PMA treated-group were higher than control group(P＜0.05). The MVD of Rh-ES+PMA treated-group was higher than Rh-ES treated group,Go6983treated-group and Rh-ES+Go6983treated-group,but had no difference compared with control group at the same time (P>0.05). The MVD of Rh-ES+Go6983treated-group was lower than control group (P＜0.05).4. Expression of PKC-alpha:There was no differences to the expression of PKC-alpha in Rh-ES treated-group compared with control group in any PWDs(P＞0.05). Since the7th PSDs,the expression of PKC-alpha increased significantly in all groups.The expression levels of PKC-alpha was higher in PMA treated-group or Rh-ES+PMA treated-group than in other groups(P＜0.05),while lower in Go6983treated-group or Rh-ES+G66983treated-group than in other groups (P＜0.05). There was no significant difference between PMA treated-group and Rh-ES+PMA treated-group,as well as Go6983treated-group and Rh-ES+Go6983treated-group(P>0.05).Conclusions1. Endostatin might reduce the microvessel density of the granulation tissue and delay wound healing.2. PKC-alpha might not mediate the anti-angiogenesis effect of endostatin on wound healing.3.PKC activator (PMA) might promote wound healing, and PKC inhibitor (Go6983) was just the opposite. |
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