[Effect of electroacupuncture on hepatocyte autophagy and oxidative stress in SAMP8 mice by regulating AMPK/mTOR/ULK1 signaling pathway].

OBJECTIVE: To observe the effect of electroacupuncture (EA) on physical strength and expression levels of hepatic AMP-activated protein kinase (AMPK), mammalian target of rapamycin (mTOR), unc-51 like autophagy activating kinase 1 (ULK1) proteins and Atg5, Atg7, Atg13, Beclin1 and ULK1 mRNAs in aging (senescence accelerated mouse/prone 8, SAMP8)mice, so as to exp lore its mechanism underlying delaying aging by activating AMPK/mTOR/ULK1 signaling pathway. METHODS: Twenty-four male SAMP8 mice were randomly divided into model group, rapamycin (autophagy inducer) group, EA group and EA+autophagy inhibitor (EA+inhibitor) group, with 6 mice in each group, and 6 homologous anti-rapid aging male (SAMR1) mice in the same age were used as the control group. Mice of the rapamycin group received intraperitoneal injection of rapamycin solution (2 mg·kg-1·d-1). EA (2 Hz, 1 mA) was applied to bilateral "Taichong"(LR3)and "Shenshu"(BL23) for 15 min each time. Mice of the EA+inhibitor group received intraperitoneal injection of mTOR inhibitor 3-methyladenine (1.5 mg·kg-1·d-1) before the EA intervention each time. The above-mentioned interventions were conducted 6 times a week for 2 consecutive weeks. Physical conditions of mice were assessed by exhaustive swimming tests. Histopathological changes of the liver were observed by H.E. staining. Western blot was used to detect the expression of AMPK, phosphorylated AMPK (p-AMPK), mTOR, phosphorylated mTOR (p-mTOR), ULK1 and phosphorylated ULK1 (p-ULk1) in the liver tissues. The expression levels of Atg5, Atg7, Atg13, Beclin1 and ULK1 (cellular autophagy-related genes) mRNAs in the liver were detected by quantitative real-time PCR. The immunoactivity (IA) of heme oxygenase 1 (HO-1) in the liver was detected by immunohistochemistry, and the activity of superoxide dismutase (SOD) and the content of malondialdehyde (MDA) of the liver were measured by hydroxylamine method for assessing the level of oxidative stress. RESULTS: Compared with the control group, the duration of exhaustive swimming, the expression levels of AMPK, p-AMPK, ULK1 and p-ULK1 proteins, and Atg5, Atg7, Atg13, Beclin1 and ULK1 mRNA, HO-1 IA and SOD activity were considerably down-regulated (P<0.01), while the expression levels of mTOR and p-mTOR and MDA content were significantly up-regulated (P<0.01) in the model group. In comparison with the model group, the duration of the exhausted swimming, the expression levels of AMPK, p-AMPK, ULK1 and p-ULK1 proteins, and Atg5, Atg7, Atg13, Beclin1 and ULK1 mRNAs, HO-1 IA and SOD activity were significantly up-regulated (P<0.01, P<0.05), whereas the expression levels of mTOR and p-mTOR proteins and MDA content were notably down-regulated (P<0.01, P<0.05) in the rapamycin, EA and EA+inhibitor groups. The improvement of the abovementioned indexes of EA+inhibitor group was not as good as rapamycin and EA groups (P<0.01), suggesting an elimination of the therapeutic effects after administration of 3-methyladenine. No significant differences were found between the rapamycin and EA groups in the abovementioned indexes (P>0.05) except p-mTOR and mTOR which were higher in the EA group (P<0.01). H.E. staining showed ambiguous boundary of the liver lobule, disordered arrangement of hepatocytes with a large amount of fat vacuoles at different size and deviation of nucleus, and lysis of some hepatocytes. These situations were relatively milder in the rapamycin and EA groups. CONCLUSION: EA may enhance physical strength and promote cellular autophagy in the liver of aging mice by regulating AMPK/mTOR/ULK1 signaling, thereby inhibiting excessive oxidative stress, and delaying aging process to some extent.

Yiqi Jiedu Huayu Decoction Alleviates Renal Injury in Rats With Diabetic Nephropathy by Promoting Autophagy.

Diabetic nephropathy (DN), a common microvascular complication of diabetes, is one of the main causes of end-stage renal failure (ESRD) and imposes a heavy medical burden on the world. Yiqi Jiedu Huayu decoction (YJHD) is a traditional Chinese medicine formula, which has been widely used in the treatment of DN and has achieved stable and reliable therapeutic effects. However, the mechanism of YJHD in the treatment of DN remains unclear. This study aimed to investigate the mechanism of YJHD in the treatment of DN. Sprague-Dawley rats were randomly divided into a normal control group, a diabetic group, an irbesartan group, and three groups receiving different doses of YJHD. Animal models were constructed using streptozotocin and then treated with YJHD for 12 consecutive weeks. Blood and urine samples were collected during this period, and metabolic and renal function was assessed. Pathological kidney injury was evaluated according to the kidney appearance, hematoxylin-eosin staining, Masson staining, periodic-acid Schiff staining, periodic-acid Schiff methenamine staining, and transmission electron microscopy. The expression levels of proteins and genes were detected by immunohistochemistry, western blotting, and real-time qPCR. Our results indicate that YJHD can effectively improve renal function and alleviate renal pathological injury, including mesangial matrix hyperplasia, basement membrane thickening, and fibrosis. In addition, YJHD exhibited podocyte protection by alleviating podocyte depletion and morphological damage, which may be key in improving renal function and reducing renal fibrosis. Further study revealed that YJHD upregulated the expression of the autophagy-related proteins LC3II and Beclin-1 while downregulating p62 expression, suggesting that YJHD can promote autophagy. In addition, we evaluated the activity of the mTOR pathway, the major signaling pathway regulating the level of autophagy, and the upstream PI3K/Akt and AMPK pathways. YJHD activated the AMPK pathway while inhibiting the PI3K/Akt and mTOR pathways, which may be crucial to its promotion of autophagy. In conclusion, our study shows that YJHD further inhibits the mTOR pathway and promotes autophagy by regulating the activity of the PI3K/Akt and AMPK pathways, thereby improving podocyte injury, protecting renal function, and reducing renal fibrosis. This study provides support for the application of and further research into YJHD.

[Effects of electroacupuncture at "Jiaji"(EX-B2) on autophagy and endoplasmic reticulum stress in spinal cord injury mice].

OBJECTIVE: To observe the effect of electroacupuncture (EA) at "Jiaji" (EX-B2) on the levels of autophagy and endoplasmic reticulum stress in mice with spinal cord injury (SCI), so as to explore its mechanism underlying improvement of SCI. METHODS: A total of 60 female C57BL/6 mice were randomly divided into sham operation, model and EA groups， which were further divided into 7 d and 14 d subgroups (10 mice in each subgroup). The SCI model was established by pressing the exposed spinal cord (L1) with a vascular clamp for 15 s. EA was applied to bilateral EX-B2 3 h after modeling, once a day for 7 and 14 d, respectively. Basso Mouse Scale(BMS) for locomotion was used to evaluate hindlimb motor function on day 7 and 14 after SCI. H.E. staining was used to observe histopathologic changes of the injured spinal cord tissue, and Western blot employed to detect the expression of glucose regulatory protein-78 (GRP78), Caspase-12, microtubule-associated protein light chain 3 II (LC-II) and P62(also known as sqstm1/Sequestome1) proteins. Immunofluorescence staining was used to detect the immunoacti-vities of spinal CCAAT/enhancer-binding protein (C/EBP) homologous protein (CHOP, an endoplasmic reticulum stress-inducible protein) and P62. RESULTS: On the 7th and 14th day after SCI, the BMS scores and expression levels of LC3II protein were significantly down-regulated (P<0.05), and the expression levels of P62, GRP78 and Caspase-12 proteins, the immunoactivities of CHOP and P62 were all significantly up-regulated on both day 7 and 14 in the model group than in the sham operation group (P<0.05).Compared with the model group, the BMS scores and the expression levels of LC3II protein were significantly increased on both day 7 and 14 (P<0.05), while the expression levels of P62, GRP78 and Caspase-12 proteins, and the immunoactivities of CHOP and P62 were obviously decreased on day 7 and 14 in the EA group (P<0.05). Outcomes of H.E. stain showed that the cells with nuclei pyknosis and swelling and the necrotic cells appeared in the model group, which was relatively fewer in the EA group. CONCLUSION: EA of EX-B2 can improve the locomotor function in SCI mice, which may be related to its effects in up-regulating the expression of LC3II (to promote cell autophagy), and down-regulating the expression of P62, GRP78, Caspase-12 and CHOP proteins (to inhibit endoplasmic reticulum stress) in the spinal cord tissue.