二冬消渴方通过PI3K/AKT/mTOR通路调控泪腺自噬改善2型糖尿病干眼的机制OA

Objective:To investigate the specific mechanism of how Erdong Xiaoke Decoction(EDXKD)regulates lacrimal gland autophagy through the phosphatidylinositol 3-kinase(PI3K)/protein kinase B(AKT)/mammalian target of rapamycin(mTOR)pathway,thereby improving the dry eye condition in diabetes rats.Methods:A total of 20 healthy male SD rats were randomly divided into the control group,the model group,the traditional Chinese medicine(TCM)group,and the prophylactic drug group,with 5 rats in each group.The rats in the control group were fed with standard diet,and the rats in the other groups were fed with high sugar and fat diet.After 4 weeks,streptozotocin(STZ)was injected intraperitoneally for 8 consecutive weeks to establish the model of type 2 diabetes dry eye rats.The control group and the model group were given 10 mL/kg physiological saline by gavage,the TCM group was given 11 g/kg EDXKD by gavage,and the prophylactic drug group was given sodium hyal-uronate eye drops in both eyes for 4 consecutive weeks.Before modeling,after modeling,and after intervention,dry eye related indicators such as corneal fluorescence staining(FL),tear film rupture time(BUT),and phenol red cotton thread test(PRT)were compared in each group of rats.After sampling,the weight of the lacrimal gland was measured,and H&E staining was used for pathological observation of the lacrimal gland.Transmission electron microscopy was used to observe autophagosomes in the lacrimal gland.And Western blot and RT-PCR techniques were used to detect the expression of PI3K,AKT,mTOR,microtu-bule associated protein 1 light chain 3(LC3),chelator-1(SQSTM1/p62)protein and mRNA in the lacrimal gland.Results:Af-ter modeling,there was no statistically significant difference in dry eye indicators among all groups except the control group(P>0.05).Compared to the control group,the other groups showed an increase in FL and a decrease in BUT and PRT(P<0.05).Af-ter intervention,compared to the control group,the model group rats showed significant dry eye symptoms,with an increase in FL,a decrease in BUT and PRT(P<0.05),a reduction in lacrimal gland weight(P<0.05),atrophy of H&E stained glandular lobules,dilation of glandular lumen,a decrease in autophagosomes under electron microscopy,and activation of PI3K,AKT,mTOR phosphorylation and increased mRNA expression in lacrimal gland tissue(P<0.05).Compared to the model group,both the TCM group and the prophylactic drug group showed a reversal of the above indicators(P<0.05).Conclusion:EDXKD inhib-its the activation of PI3K/AKT/mTOR pathway in lacrimal gland of diabetes dry eye rats,and increases autophagy level to allevi-ate lacrimal gland damage,thereby alleviating dry eye symptoms.