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ObjectiveTo investigate the protective effect of modified Huangqi Guizhi Wuwutang （MHGW） on endoplasmic reticulum stress in the sciatic nerve of diabetes rats based on the pathways of inositol-requiring enzyme 1α （IRE1α） and CCAAT/enhancer-binding protein homologous protein （CHOP）. MethodSixty rats were fed on a high-sugar and high-fat diet for six weeks， followed by intraperitoneal injection of streptozotocin at a dose of 35 mg·kg-1. Random blood glucose levels were measured three days later and rats with a sustained blood glucose level ≥ 16.7 mmol·L-1 were included in study （n=48）. The rats were randomly divided into a model group， an α-lipoic acid group （0.026 8 g·kg-1·d-1）， a high-dose MHGW group （2.5 g·kg-1·d-1）， and a low-dose MHGW group （1.25 g·kg-1·d-1）. Another 10 rats were assigned to the normal group. The intervention lasted for 16 weeks. After 16 weeks， the sciatic nerve structure of the rats in each group was observed under light microscopy using Luxol fast blue （LFB） staining. Transmission electron microscopy was used to observe the ultrastructure of the sciatic nerve. Chemiluminescence method was employed to measure the serum reactive oxygen species （ROS） levels. Western blot and real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） were used to evaluate the expression of p-IRE1α protein， IRE1α mRNA， CHOP protein， and CHOP mRNA in the sciatic nerve of the rats. ResultCompared with the normal group， the model group showed elevated serum ROS levels （P<0.01）. In contrast， the serum ROS levels were significantly reduced in the treatment groups compared with those in the model group （P<0.01）. The sciatic nerve of the model group showed pathological changes compared with that in the normal group， while the treatment groups exhibited improvement in sciatic nerve pathology compared with the model group. The protein expression of p-IRE1α and CHOP in the sciatic nerve significantly increased in the model group as compared with that in the normal group （P<0.01）. However， the treatment groups showed a significant decrease in the protein expression of p-IRE1α and CHOP in the sciatic nerve compared with the model group （P<0.05， P<0.01）. Furthermore， compared with the normal group， the model group showed upregulated mRNA expression of IRE1α and CHOP in the sciatic nerve （P<0.01）， while the treatment groups exhibited a significant decrease in the mRNA expression of IRE1α and CHOP compared with the model group （P<0.01）. ConclusionMHGW can alleviate endoplasmic reticulum stress-induced cell apoptosis and improve the structure and function of the sciatic nerve in diabetes rats by inhibiting the expression of IRE1α/CHOP pathway-related proteins and mRNA， thereby preventing and treating peripheral neuropathy in diabetes.
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ObjectiveTo investigate the mechanism of Huangqi Guizhi Wuwutang （HQGZWWT） in the treatment of diabetic peripheral neuropathy （DPN） in MKR mice via regulating endoplasmic reticulum （ER） stress. MethodThirty-two 8-week-old MKR mice （half were male and half were female） were fed with a high-fat diet for four weeks， and then 1% streptozotocin （STZ） was injected intraperitoneally for five days. After the blood glucose was stabilized， the mice were housed in the cage covered with ice bags for another one hour stimulation per day for four weeks. Mice with fasting blood glucose （FBG） value ≥11.1 mmol·L-1 were randomly divided into model group ， Huangqi Guizhi Wuwutang in original dosage group （30 g·kg-1·d-1）， Huangqi Guizhi Wuwutang in formula dosage group （6.25 g·kg-1·d-1）， and positive drug group （mecobalamin tablets， 0.17 mg·kg-1·d-1）. Another eight MKR mice of the same age were set as blank group and eight FVB mice were normal group. After four weeks of intragastric administration in each group， the change in FBG was tested， and hematoxylin and eosin （HE） staining and transmission electron microscope were used for observing the morphology of sciatic nerve tissue. In addition， the expression of c-Jun N-terminal kinase （JNK）， phosphorylated c-Jun N-terminal kinase （p-JNK） and inositol requiring enzyme 1α （IRE1α） proteins was determined by immunohistochemical test and Western blot （WB）. ResultCompared with the conditions in the normal group and blank group， the time of paw withdrawal， paw licking and tail flick in the model group was shortened （P<0.01）， and the conduction velocity of sciatic nerve was decreased （P<0.01）. Compared with the conditions in the model group， the behavioral and functional indicators were improved by HQGZWWT （P<0.05，P<0.01）. The immunohistochemical test revealed the JNK expression was elevated in the model group compared with the conditions in the normal group and blank group （P<0.05）， while that was lowered by HQGZWWT compared with the condition in the model group （P<0.05）. However， there was no difference among the treatment groups. According to the WB， the expression of IRE1α and p-JNK in the model group was enhanced compared with the conditions in the normal group and blank group （P<0.05，P<0.01）， while that was decreased by HQGZWWT compared with the condition in the model group （P<0.05，P<0.01）. No difference was observed between the HQGZWWTO and HQGZWWTF groups. ConclusionHQGZWWT can improve the neurophysiological function and pathological damage of sciatic nerve， which may be related to its delaying the ER stress response of sciatic nerve.
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A common pathological features of Alzheimer's disease (AD) is the excessive activation of inositol-requiring enzyme-1α (IRE1α) downstream of endoplasmic reticulum stress (ERS) and the abnormal expression of microRNA (miRNA) with a variety of cellular physiological functions. Studies have found that IRE1α and miRNA are not alone in the AD pathologenesis. IRE1α can regulate the expression of miR-200, miR-7, miR-17 and miR-34, and participate in most AD brain diseases such as Aβ deposition, Tau protein hyperphosphorylation and neuronal apoptosis. It is suggested that IRE1α-miRNA signal abnormality is one of the pathological mechanisms of AD. Exercise can prevent and delay AD, but its mechanism is unclear. Studies have found that exercise could interfere with AD by regulating the IRE1αmiRNA signaling pathway. The specific mechanisms of action include: (1) Exercise improves the adaptation of AD brain energy metabolism and alleviates the excessive activation of brain IRE1α signals. (2) Exercise regulates the expression of miRNA in the brain, exerts epigenetic effects, and reduces pathologies such as Aβ and Tau protein aggregation. (3) The IRE1α-miRNA pathway and its downstream protein changes can mediate exercise to resist the development of AD. This article will review the relationship between IRE1α-miRNA and AD pathology and its exercise feedback mechanism, aiming to provide evidence and ideas for AD diagnosis and treatment strategies.