Effect And Mechanism Of C66 On Skin Wound Healing In Diabetic Mice

Objective:Diabetes is a systemic metabolic disorder syndrome with hyperglycemia as a typical clinical manifestation.The severity of diabetes is not in diabetes itself,but in its complications,such as diabetic retinopathy,diabetic nephropathy,diabetic wounds and ulcers.There is currently no effective treatment for diabetic refractory wounds.The mechanism that causes diabetic skin ulcers and wound healing is not clear,but it is closely related to the persistence of inflammation.Curcumin has been proven to improve the healing of diabetic wounds and has strong anti-inflammatory and antioxidant effects,but its low bioavailability and poor solubility severely limit its clinical application.The new curcumin homolog C66 makes up for this shortcoming of natural curcumin,its bioavailability is greatly improved,and it has a good clinical application prospect.Therefore,in-depth research on the role and mechanism of curcumin homolog C66 in diabetic difficult-to-heal wounds,and the rational and effective use of wound healing agents containing curcumin and its homologs can provide new methods and ideas for the treatment and care of diabetic hard-wound wounds.Methods:In this experiment,a diabetic mouse model induced by streptozotocin(STZ)was used to observe the distribution characteristics and local content of CD31 and Ki67 positive cells in the skin of diabetic rats two weeks after the onset of diabetes.H&E staining was used to observe the pathological changes of skin tissue under light and electron microscopy.Based on this,a full-thickness skin cut wound was used,and local concentrations of C66 were administered at different concentrations.The wound healing was dynamically monitored and photographed to record changes in the wound state to observe the effects of C66.Collect the wounds of mice in each group on the tenth day of administration.Site tissues,q-PCR was used to detect inflammatory factor-related genes and miR-146 a content in wound tissues,histopathological analysis of the effects of quercetin on diabetic refractory wounds,and IRAK1,NF-?B And the expression of NF-?B phosphorylated protein;further explore the effect of C66 on wound site inflammation and microRNAs to clarify the mechanism of C66 promoting diabetic wound healing.It lays the theoretical and experimental basis for its further clinical application.Finally,human umbilical vein cells were cultured in vitro,and the effect of C66 on the NF-?B signaling pathway was observed by transfection with miR-146 inhibitors and immunoblot tests.The mechanism of topical application of C66 on the healing of diabetic wounds was initially discussed.Results:One week after intraperitoneal injection of streptozotocin,blood glucose in rats increased and stabilized above 16.7 mmol/L.Topical application of C66 improves skin wound healing in vivo.Observation of pathological changes in the skin tissue of diabetic mice by light microscopy showed that the epidermis and dermis became thinner,suggesting that cell proliferation activity was weakened.Further studies show that C66 treatment can increase streptozotocin(STZ)-induced diabetic mouse wounds in microRNA-146a(miR-146a)levels,down-regulate interleukin 1 receptorrelated kinase 1(IRAK1)and phosphorylated nucleus Factor expression-?B(NF-?B)p65 subunit(p-p65)(P < 0.05),and inhibit inflammation-related cytokines,tumor necrosis factor-?(TNF-?),interleukin-8(IL-8)MRNA expression)and interleukin 6(IL-6).In vitro data obtained in human umbilical vein endothelial cells(HUVEC)showed that,due to the upregulation of miR-146 a expression,C66 can reverse the activation of NF-?B induced by high glucose(HG),which is consistent with in vivo experiments.Conclusion:1.C66 retains the anti-inflammatory activity of curcumin to promote the healing of skin wounds in diabetic mice.The healing effect is better than curcumin and it shows a dose-dependent improvement.2.C66 inhibits the NF-?B-mediated inflammatory pathway by upregulating miR-146 a,which ultimately leads to reduced production of inflammatory cytokines such as IL-8,IL-6 and TNF-? and ultimately promotes wound healing.