ABSTRACT
Aim To observe the effectof paeoniflorin (PA) on diabetic wound healing and its mechanisms. Methods A full-thickness skin excision splint model in diabetic mice was used to study the effects of PA on diabetic wound healing and the underlying mechanism. HE staining and Masson staining were used to observe the changes of granulation tissue and collagen in wound tissues. Immunofluorescence technique was employed to detect angiogenesis in wound tissues of diabetic mice. To detect the effects of PA, human umbilical vein endothelial cells ( HUVECs) and mouse fibroblasts were cultured in vitro. MTS, BrdU and scratch assays were used to detect the effects of PA on proliferation and migration. Tube formation assays were used to detect the effects of PA on the tube formation of HUVECs. qPCR was applied to assess the expression of collagen HI, fibronectin and ot-SMA gene. Immunoflu orescence was used to detect the expression of a-SMA. Results Compared with db/db model group, the formation rate of granulation tissues and collagen and the capillary density around the wound of db/db model group treated with PA was significantly higher than that of db/db model group(P <0. 01 ). PA had no significant effect on endothelial cell proliferation, but it could markedly promote endothelial cell migration and tube formation. PA could significantly up-regulate the migration , proliferation, secretion and differentiation of fibroblasts. Conclusions PA can significantly promote diabetic wound healing, which may be related to accelerating the generation of extracellular matrix and promoting angiogenesis.
ABSTRACT
Human cardiac fibroblasts (HCFs) have various voltage-dependent K+ channels (VDKCs) that can induce apoptosis. Hydrogen peroxide (H2O2) modulates VDKCs and induces oxidative stress, which is the main contributor to cardiac injury and cardiac remodeling. We investigated whether H2O2 could modulate VDKCs in HCFs and induce cell injury through this process. In whole-cell mode patch-clamp recordings, application of H2O2 stimulated Ca2+-activated K+ (K(Ca)) currents but not delayed rectifier K+ or transient outward K+ currents, all of which are VDKCs. H2O2-stimulated K(Ca) currents were blocked by iberiotoxin (IbTX, a large conductance K(Ca) blocker). The H2O2-stimulating effect on large-conductance K(Ca) (BK(Ca)) currents was also blocked by KT5823 (a protein kinase G inhibitor) and 1 H-[1, 2, 4] oxadiazolo-[4, 3-a] quinoxalin-1-one (ODQ, a soluble guanylate cyclase inhibitor). In addition, 8-bromo-cyclic guanosine 3', 5'-monophosphate (8-Br-cGMP) stimulated BK(Ca) currents. In contrast, KT5720 and H-89 (protein kinase A inhibitors) did not block the H2O2-stimulating effect on BK(Ca) currents. Using RT-PCR and western blot analysis, three subtypes of K(Ca) channels were detected in HCFs: BK(Ca) channels, small-conductance K(Ca) (SK(Ca)) channels, and intermediate-conductance K(Ca) (IK(Ca)) channels. In the annexin V/propidium iodide assay, apoptotic changes in HCFs increased in response to H2O2, but IbTX decreased H2O2-induced apoptosis. These data suggest that among the VDKCs of HCFs, H2O2 only enhances BK(Ca) currents through the protein kinase G pathway but not the protein kinase A pathway, and is involved in cell injury through BK(Ca) channels.