电针通过调控TLR4介导的炎症信号通路改善糖尿病干眼大鼠角膜炎症的机制研究OACSTPCD

Objective To observe the effect of electroacupuncture on corneal Toll-like receptor 4(TLR4)-mediated inflammatory signaling pathway in diabetic dry eye rats and to explore the mechanism of electroacupuncture in the treat-ment of diabetic dry eye.Methods A type 2 diabetic rat model was established in 32 healthy male Sprague-Dawley(SD)rats by intraperitoneal injection of streptozotocin(30 mg·kg-1)for 12 weeks after feeding with high-sugar and high-fat di-et for 4 weeks.Twenty-five successfully modeled diabetic dry eye rats were randomly divided into the model group(non-in-tervention),electroacupuncture group(the"Jingming","Cuanzhu","Sizhukong","Taiyang"and"Tongziliao"acupoints were treated with acupuncture,and then"Cuanzhu"and"Tongzilao"acupoints were treated with electroacupuncture,15 min for each time,once a day),sham acupuncture group(blunt-tip needle pricking was performed at the same acupoints as the electroacupuncture group),and fluorometholone group(1 g·L-1fluorometholone eye drops were used in both eyes at 8 o'clock,13 o'clock,and 18 o'clock,1 drop each time),with 6 rats in each group,lasting for 2 weeks.Another 6 healthy male SD rats were selected as a blank group.Random blood glucose,tear film breakup time(BUT),tear secre-tion,corneal fluorescein staining(FL)score,and corneal touch threshold(CTT)of rats in each group were detected be-fore modeling,after modeling,and after the intervention.Hematoxylin and Eosin(HE)staining was performed to observe the corneal morphologic changes in each group.Immunofluorescence histochemical staining was adopted to detect the cor-neal TLR4-positive expression in each group.The TLR4,phosphorylated nuclear factor-kappa P65(P-NF-KB P65),inter-leukin(IL)-1β,and IL-18 expression levels in the cornea were detected by Western blot.Results After modeling,com-pared with the blank group,BUT,tear secretion and CTT decreased and FL increased in all experimental groups,and the differences were statistically significant(all P＜0.01).After the intervention,compared with the model group,FL de-creased,and BUT,tear secretion and CTT increased in the electroacupuncture group,and the differences were statistically significant(all P＜0.05).Corneal HE staining showed that after the intervention,the corneal surface of rats in the model group and sham acupuncture group was not smooth,and the corneal epithelial cells were thickened and disorganized;the corneal surface of rats in the electroacupuncture group and fluorometholone group was smooth,and the corneal epithelial cells were arranged neatly.After the intervention,compared with the blank group,the corneal TLR4 expression of rats in all other groups was elevated,and the differences were statistically significant(all P＜0.05);compared with the model group,the corneal TLR4 expression of rats in the electroacupuncture group and fluorometholone group was reduced(both P＜0.01).Compared with the blank group,corneal TLR4,P-NF-κBP65,IL-1β and IL-18 protein expressions increased in the model group and sham acupuncture group(all P＜0.05);compared with the model group,these expressions decreased in the electroacupuncture group and the fluorometholone group(all P＜0.05).Conclusion Electroacupuncture can im-prove the ocular surface signs and inhibit the expressions of TLR4,P-NF-κB P65,IL-1 β,and IL-18 in the cornea of type 2 diabetic dry eye rats,and its mechanism of action may be related to the regulation of TLR4-mediated inflammatory signaling pathway,which inhibits ocular surface inflammation in diabetic dry eye rats.