查找使用阿拉丁产品的科研文献

Lactobacillus improves meat quality in Sunit sheep by affecting mitochondrial biogenesis through the AMPK pathway

Wang Chenlei,Yan Xinlei,Bai Yanping,Sun Lina,Zhao Lihua,Jin Ye,Su Lin

Sunit sheep are famous for their high meat quality, but the meat quality of them has declined due to the change in feeding methods. Lactobacillus has a variety of probiotic effects and is widely used in animal diets to optimize meat quality. This study aimed to investigate the effect of dietary supplementation with different levels of Lactobacillus on meat quality. A total of 24 3-month-old Sunit sheep with an average body weight of 19.03 ± 3.67 kg were randomly divided into control (C), 1% (L1), 2% (L2), and 3% Lactobacillus groups (L3), with 6 sheep in each group. Myofiber characteristics, meat quality, and metabolic enzyme activity were detected. Moreover, the regulatory mechanism of Lactobacillus on meat quality was explored by using Western blotting and real-time Quantitative polymerase chain reaction (RT-qPCR). The results showed that dietary addition of Lactobacillus decreased LDH activity in the Biceps femoris of Sunit sheep (P < 0.05). Compared to the other groups, the 1% Lactobacillus group showed the conversion of myofibers from the glycolytic to the oxidative type, and the increasing b* values (P < 0.05), decreasing shear force and cooking loss of meat (P < 0.05) and the relative gene and protein expression levels of AMPK, PGC-1α, NRF1, TFAM, and COX IV (P < 0.05) in the Biceps femoris were also increased in the 1% Lactobacillus group. Therefore, the addition of Lactobacillus to the diet of Sunit sheep could regulate the AMPK signaling pathway to promote myofiber type conversion, which improves meat quality. This study provided a theoretical and data basis for improving the meat quality of sheep and supplied a novel way of applying Lactobacillus.

Salidroside alleviates oxidative stress in dry eye disease by activating autophagy through AMPK-Sirt1 pathway

Qi Liang,Rongjie Guo,Jia-Ruei Tsao,Yun He,Chenchen Wang,Jiaxuan Jiang,Di Zhang,Taige Chen,Tingting Yue,Kai Hu

Dry eye disease (DED) is a multifactorial disease, and oxidative stress plays a crucial role in its pathogenesis. Recently, multiple studies have shown that upregulation of autophagy can protect the cornea from oxidative stress damage. The present study investigated the therapeutic effects of salidroside, the main component of Rhodiola crenulata , in both in vivo and in vitro dry eye models. The results showed that topical eye drop treatment with salidroside restored corneal epithelium damage, increased tear secretion, and reduced cornea inflammation in the DED mice. Salidroside activated autophagy through AMP-activated protein kinase (AMPK)-sirtuin-1 (Sirt1) signaling pathway, which promoted the nuclear translocation of nuclear factor erythroid-2-related factor 2 (Nrf2) and increased the expression of downstream antioxidant factors heme oxygenase-1 (HO-1) and NAD(P)H quinone dehydrogenase 1 (NQO1). This process restored antioxidant enzyme activity, reduced reactive oxygen species (ROS) accumulation, and alleviated oxidative stress. The application of autophagy inhibitor chloroquine and AMPK inhibitor Compound C reversed the therapeutic efficacy of salidroside, validating the above findings. In conclusion, our data suggest that salidroside is a promising candidate for DED treatment.

Hydrogen inhalation enhances autophagy via the AMPK/mTOR pathway, thereby attenuating doxorubicin-induced cardiac injury

Tianjiao Ma,Lei Yang,Binmei Zhang,Xin Lv,Feifei Gong,Wei Yang

Aims Doxorubicin is a drug widely used in clinical cancer treatment, but severe cardiotoxicity limits its clinical application. Autophagy disorder is an important factor in the mechanism of doxorubicin-induced cardiac injury. As the smallest molecule in nature, hydrogen has various biological effects such as anti-oxidation, anti-apoptosis and regulation of autophagy. Hydrogen therapy is currently considered to be an emerging therapeutic method, but the effect and mechanism of hydrogen on doxorubicin-induced myocardial injury have not been determined. The purpose of this study was to investigate the protective effect of hydrogen inhalation on doxorubicin-induced chronic myocardial injury and its effect and mechanism on autophagy. Methods In this study, we established a chronic heart injury model by intraperitoneal injection of doxorubicin in rats for 30 days, accumulating 20 mg/kg. The effect of hydrogen inhalation on the cardiac function in rats was explored by echocardiography, Elisa, and H&E staining. To clarify the influence of autophagy, we detected the expression of LC3 and related autophagy proteins in vivo and in vitro by immunofluorescence and western blot.In order to further explore the mechanism of autophagy, we added pathway inhibitors and used western blot to preliminarily investigate the protective effect of hydrogen inhalation on myocardial injury caused by doxorubicin. Results Hydrogen inhalation can improve doxorubicin-induced cardiac function decline and pathological structural abnormalities in rats. It was confirmed by immunofluorescence that hydrogen treatment could restore the expression of autophagy marker protein LC3 (microtubule-associated protein 1 light chain 3) in cardiomyocytes reduced by doxorubicin, while reducing cardiomyocyte apoptosis. Mechanistically, Western blot results consistently showed that hydrogen treatment up-regulated the ratio of p-AMPK (phosphorylated AMP-dependent protein kinase) to AMPK and down-regulated p-mTOR (phosphorylated mammalian target of rapamycin) and mTOR ratio. Conclusions These results suggest that hydrogen inhalation can activate autophagy through the AMPK/mTOR pathway and protect against myocardial injury induced by doxorubicin. Hydrogen inhalation therapy may be a potential treatment for doxorubicin-induced myocardial injury.

Bisphenol A promotes autophagy in ovarian granulosa cells by inducing AMPK/mTOR/ULK1 signalling pathway

Miaoling Lin,Rui Hua,Jing Ma,Yao Zhou,Pei Li,Xiya Xu,Zhiqiang Yu,Song Quan

Background Bisphenol A (BPA) is a widespread endocrine-disrupting chemical with estrogen like effects, which could interfere with the human reproductive system by disrupting the normal function of granulosa cells (GCs) leading to abnormal ovarian function. However, the mechanism of its toxicity on human GCs has not been clearly described thus far. Methods 106 normogonadotropic infertile women undergoing their first in-vitro fertilization-embryo transfer (IVF-ET) cycle were recruited. Urinary BPA level and the early outcomes of IVF-ET were analysed. Patients were divided to low and high BPA exposure groups using the median urinary BPA concentration as the cut-off value. In-vivo and in-vitro studies were conducted using mice and human granulosa cell line (KGN cells). Female Kunming mice approximately 6–8 weeks of age were poisoned with BPA at different dosages (1, 10 or 100 μg/kg) by oral gavage once daily for 2 weeks, while KGN cells were exposed to BPA at the concentration of 1, 10 or 100 nM for 24 h, 48 h or 72 h. BPA-induced ovarian morphologic changes were analysed by histopathology investigation. Cell viability and apoptosis were evaluated using CCK-8, TUNEL and flowcytometric, respectively. Hormone levels were determined using ELISA and the molecular mechanism studies were conducted using immunofluorescence, RT-PCR and western blots. Results The oocyte retrieval rate, maturation rate and embryo implantation rate significantly decreased with the higher level of urinary BPA concentration. Peak E2 level was lower in high BPA group, but no statistical significance could be observed. In BPA treated mice, cystic dilation of the follicles with a decreased number of GCs could be observed histopathologically. Decreased E2, P4 and AMH level and GCs autophagy could be detected both in-vivo and in-vitro with the activation of AMPK/mTOR/ULK1 signalling pathway. As being confirmed in KGN cells, phosphorylated AMPK and ULK1 increased while phosphorylated mTOR decreased, and by inhibition autophagy using knockdown of AMPK or 3-MA, adverse effects of BPA exposure in-vitro could be reversed. Conclusion BPA exposure might abnormally influence human ovarian functions leading to abnormal folliculogenesis by activation of autophagy in GCs through AMPK/mTOR/ULK1 pathway.

Cordycepin protects against acute pancreatitis by modulating NF-κB and NLRP3 inflammasome activation via AMPK

Jing Yang,Yiwen Zhou,Jinsong Shi

Acute pancreatitis (AP) is a noninfectious inflammatory disease with high morbidity and mortality, which is characterized by severe inflammation and tissue necrosis. Cordycepin (CRD), derived from Cordyceps militaris , possesses anti-inflammatory effects and immunomodulation properties. Here, we investigated the protective effects of CRD on pancreatic injury and clarified potential mechanisms in AP model. There were established caerulein-induced AP and CRD pretreatment models in vivo and in vitro, as showed by serum enzymes, histopathological alterations and pro-inflammatory cytokines. Pretreatment with CRD notably downregulated the serum amylase and lipase levels and apparently reduced pancreatic histopathological alterations in AP mice. Meanwhile, the MPO staining confirmed that CRD pretreatment modulated the infiltration of neutrophils in AP mice. Furthermore, CRD markedly decreased the levels of pro-inflammatory factors (IL-6, IL-1β, and TNF-α) though inhibiting the activation of nuclear factor-κB (NF-κB) and NLR family pyrin domain-containing protein 3 (NLRP3) inflammasome in AP mice. In pancreatic acinar cancer cell 266-6, CRD pretreatment decreased cholecystokinin(CCK)-induced inflammatory response was consistent with those in vivo. Mechanistically, CRD was also revealed to activate activated protein kinase (AMPK) and attenuated inflammation both in vivo and in vitro. On the whole, this study indicated that CRD protects mice from pancreatic inflammatory process and damage by suppressed NF-κB and NLRP3 inflammasome activation via AMPK, which probably contributed to the potential therapy for AP.

SQSTM1/p62 loss reverses the inhibitory effect of sunitinib on autophagy independent of AMPK signaling

Hou Bolin,Wang Gang,Gao Quan,Wei Yanjie,Zhang Caining,Wang Yange,Huo Yuqing,Yang Huaiyi,Jiang Xuejun,Xi Zhijun

Sunitinib (ST), a multitargeted receptor tyrosine kinase inhibitor, has been demonstrated to be effective for the treatment of renal carcinoma. It has been reported that ST is involved in the mediation of autophagy; however, its regulatory role in the autophagic process remains controversial. Furthermore, the mechanism by which activated AMP-activated protein kinase (AMPK) negatively regulates autophagy remains nearly unexplored. In the present study, we revealed that ST inhibited AMPK activity and regulated autophagy in a cell type- and dose-dependent manner. In a number of cell lines, ST was demonstrated to inhibit H 2 O 2 -induced autophagy and the phosphorylation of acetyl-CoA carboxylase (ACC), whereas alone it could block the autophagic flux concurrent with increased expression of p62. An immunoprecipitation assay revealed that LC3 directly interacted with p62, whereas ST increased punctate LC3 staining, which was well colocalized with p62. Taken together, we reveal a previously unnoticed pathway for ST to regulate the autophagic process, and p62, although often utilized as a substrate in autophagy, plays a critical role in regulating the inhibition of ST in both basal and induced autophagy.

Baicalin inhibits pressure overload-induced cardiac fibrosis through regulating AMPK/TGF-β/Smads signaling pathway

Yichuan Xiao,Jiantao Ye,Ying Zhou,Junjun Huang,Xiawen Liu,Biyun Huang,Liu Zhu,Bo Wu,Genshui Zhang,Yi Cai

AMP-activated protein kinase (AMPK) is a central regulator of multiple metabolic pathways. It has been shown that activation of AMPK could inhibit fibroblast proliferation and extracellular matrix (ECM) accumulation, thereby suppressing cardiac fibrosis. Baicalin , the major component found in skullcap, possesses multiple protective effects on the cardiovascular system. However, little is known about the effect of baicalin on cardiac fibrosis and the molecular mechanism by which baicalin exerts its anti-fibrotic effects has not been investigated. In this study, we revealed that baicalin could inhibit cell proliferation , collagen synthesis , fibronectin (FN) and Connective tissue growth factor (CTGF) protein expression in cardiac fibroblasts induced by angiotensin Ⅱ (Ang Ⅱ). It also ameliorated cardiac fibrosis in rats submitted to abdominal aortic constriction (AAC). Moreover, baicalin inhibited transforming growth factor-β (TGF-β)/Smads signaling pathway stimulated with Ang Ⅱ through activating AMPK. Subsequently, we also demonstrated that baicalin attenuated Ang Ⅱ-induced Smad3 nuclear translocation, and interaction with transcriptional coactivator p300, but promoted the interaction of p300 and AMPK. Taken together, these results provide the first evidence that the effect of baicalin against cardiac fibrosis may be attributed to its regulation on AMPK/TGF-β/Smads signaling, suggesting the therapeutic potential of baicalin on the prevention of cardiac fibrosis and heart failure.

Adiponectin receptor agonist reduces broiler hepatic lipid deposition

Wenhao Tan,Kunyu Jiang,Yuhan Zhang,Hang Gao,Xingyi Tang,Sha Jiang

To investigate the effects of AdipoRon on fatty liver syndrome (FLS) in chicken, we used a corticosterone (CORT)-induced fatty liver model in Cobb broilers in vivo and fat emulsion-induced model in Leghorn male hepatoma cells (LMH) in vitro. In the in vivo study, eighteen 33-day-old male Cobb broilers were randomly assigned to three groups: control group (CONT, vehicle), corticosterone-treated group (CORT, 4 mg/kg), and corticosterone with AdipoRon-treated group (CORT-AR, 4 mg/kg and 0.2 mg/kg, 1 time/1 day) for 5 days. The results showed AdipoRon reduced CORT-induced increase in liver crude fat content (p < 0.05), increased protein expressions of peroxisome proliferator-activated receptor α (PPARα) (p < 0.05) and adiponectin (ADPN) (p < 0.05), and suppressed the protein expressions of Acetyl-CoA carboxylase 1 (ACC) (p < 0.05) and phosphorylated c-Jun N-terminal kinase 1 (p-JNK1) (p < 0.05) in the liver. In the in vitro study, LMH cells were divided into control (CN), fat emulsion (FE, 10%), and FE + AdipoRon (4 μM) group (FE-AR). AdipoRon reduced FE-induced lipid accumulation (p < 0.05), decreased the protein expression of ACC and tumor necrosis factor-alpha (TNF-α), and enhanced PPARα, the phosphorylation of adenosine 5′-monophosphate-activated protein kinase (AMPK), and carnitine palmitoyl transferase 1 (CPT-1) (p < 0.05). In conclusion, AdipoRon effectively reduces hepatic lipid deposition in CORT-induced FLS broilers, likely through PPARα activation and inhibition of lipid synthesis via ACC downregulation.

Inhibition of PRKAA/AMPK (Ser485/491) phosphorylation by crizotinib induces cardiotoxicity via perturbing autophagosome-lysosome fusion

Zhifei Xu,Zezheng Pan,Ying Jin,Zizheng Gao,Feng Jiang,Huangxi Fu,Xueqin Chen,Xiaochen Zhang,Hao Yan,Xiaochun Yang,Bo Yang,Qiaojun He,Peihua Luo

Hernandezine, a natural herbal alkaloid, ameliorates type 2 diabetes by activating AMPK in two mouse models

Jing Bai,Shuai Zhang,Jinjing Cao,Hongbin Sun,Zhiguo Mang,Wei L. Shen,Hao Li

Background AMP-activated protein kinase (AMPK) is an effective target for treating diabetes. However, successful drug development is delayed due to issues including toxicity. Plant-derived natural product AMPK activators have emerged as a new way to treat diabetes due to its potential low safety risks. Here, we studied the effect of hernandezine (HER), a natural product derived from Thalictrum , in activating AMPK and treating T2D in mouse models. Method We tested HER in various cells and tissues, including primary hepatocytes, skeletal myotubes cell lines, as well as major metabolic tissues from diabetic (db/db) and diet-induced obesity (DIO) model mice. The effect of HER on glucose uptake via AMPK in vitro and in vivo was confirmed utilizing cell transfection and adenovirus interference analysis. Tissue staining assessed the effect of HER on adipogenesis. Real-time quantitative polymerase chain reaction (real-time PCR) was applied to verify the effect of HER on transcription factors. Western blot analysis was used to determine the activation of phosphorylated AMPK and ACC pathways. Results Biochemically, we found that HER prevented pAMPK from dephosphorylation to prolong its activity, disproving previous direct activation model and providing a new model to explain HER-mediated AMPK activation. HER could be orally delivered to animals and has a 3-fold long half-life in vivo as compared to metformin. Importantly, long-term oral HER treatment potently reduced body weight and blood glucose in both type 2 diabetes mullitus (T2DM) mouse models by increasing glucose disposal and reducing lipogenesis, and appeared not to induce cardiac hypertrophy. Conclusion Natural product HER indirectly activates AMPK by suppressing its dephosphorylation. Oral HER effectively alleviated hyperglycemia and reduced body weight in T2D mouse models, appeared to have a low risk of causing cardiac hypertrophy, and might be a potential therapeutic option for T2DM.

Paeoniflorin Ameliorates Fructose-Induced Insulin Resistance and Hepatic Steatosis by Activating LKB1/AMPK and AKT Pathways

Yu-Cheng Li,Jing-Yi Qiao,Bao-Ying Wang,Ming Bai,Ji-Duo Shen,Yong-Xian Cheng

The present study aimed to evaluate the effects of paeoniflorin on insulin resistance and hepatic steatosis induced by fructose. Male Sprague-Dawley rats were fed 20% fructose drink for eight weeks. The insulin sensitivity, serum lipid profiles, and hepatic lipids contents were measured. The results showed that paeoniflorin significantly decreased serum insulin and glucagon levels, improved insulin sensitivity and serum lipids profiles, and alleviated hepatic steatosis in fructose-fed rats. Moreover, paeoniflorin enhanced the phosphorylation level of AMP-activated protein kinase (AMPK) and protein kinase B (PKB/AKT) and inhibited the phosphorylation of acetyl coenzyme A carboxylase (ACC)1 in liver. Paeoniflorin also increased the hepatic carnitine palmitoyltransferase (CPT)-1 mRNA and protein expression and decreased the mRNA expression of sterol regulatory element-binding protein (SREBP)1c, stearyl coenzyme A decarboxylase (SCD)-1 and fatty acid synthetase (FAS). Furthermore, we found that paeoniflorin significantly increased the heptatic protein expression of tumor suppressor serine/threonine kinase (LKB)1 but not Ca2+/CaM-dependent protein kinase kinase (CaMKK)β. These results suggest that the protective effects of paeoniflorin might be involved in the activation of LKB1/AMPK and insulin signaling, which resulted in the inhibition of lipogenesis, as well as the activation of β-oxidation and glycogenesis, thus ameliorated the insulin resistance and hepatic steatosis. The present study may provide evidence for the beneficial effects of paeoniflorin in the treatment of insulin resistance and non-alcoholic fatty liver.Keywords:insulin resistance;hepatic steatosis;paeoniflorin;AMPK

Glucocorticoid-induced RPE injury in ARPE-19 cells: association with excessive autophagy and AMPK/mTOR signaling

Wen-Xue Guan,Yue Guo,Si-Tong Chen,Zhi-Ming Liu,Yao-Yao Sun,Ming-Wei Zhao

AIM To investigate whether excessive glucocorticoid (GC) exposure disrupts retinal pigment epithelial (RPE) homeostasis through glucocorticoid receptor (GR)-dependent autophagy hyperactivation. METHODS Human retinal pigment epithelial cell line (ARPE-19 cells) were exposed to GC (0–100 µmol/L, 48h). GR subcellular localization was analyzed via mitochondrial fractionation and immunofluorescence. Functional assessments included barrier integrity [zonula occludens-1 (ZO-1) immunostaining], phagocytic capacity (FluoSpheres™-labeled photoreceptor outer segment uptake), and ultrastructural analysis (transmission electron microscopy, TEM). Autophagic flux was quantified using mCherry-green fluorescent protein-microtubule-associated protein 1A/1B-light chain 3 (LC3) B reporters. Molecular mechanisms were probed through AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway activity and autophagic flux assessed by LC3-II levels. GR dependency was confirmed using the antagonist RU486, and cell-type specificity was assessed using mouse photoreceptor (661W) cells. RESULTS GC induced GR upregulation and mitochondrial translocation in a dose- and time-dependent manner, correlating with pathological autophagy activation. Key findings included: 1) tight junction disruption, evidenced by ZO-1 fragmentation, 2) reduction in phagocytic uptake efficiency, 3) mitochondrial shrinkage and autolysosome accumulation (TEM), 4) altered AMPK/mTOR signaling (p-AMPK up, p-mTOR down) associated with autophagosome formation, 5) elevated LC3-II levels confirming excessive autophagic flux. Critically, all GC-induced effects, including GR upregulation, signaling changes, and increased autophagy, were abolished by GR antagonism with RU486. CONCLUSION This study shows that GR-dependent GC exposure induces autophagic flux with ultrastructural evidence suggestive of mitochondria-targeted autophagy and alters AMPK/mTOR signaling, correlating with RPE barrier collapse and phagocytic failure, a possible link to steroid-associated central serous chorioretinopathy (CSC).