The AMP-activated protein kinase (AMPK) is a pivotal serine/threonine kinase participating in the regulation of glucose, lipid as well as protein metabolism and maintenance of energy homeostasis. Recent studies demonstrated that AMPK can also inhibit nuclear factor-κB, suppress the expression of inflammatory genes and attenuate inflammatory injury through phosphorylating its downstream targets including SIRT1, PGC-lα, p53 and FoxO3a. In addition, the widely used antidiabetic metformin also exerts its anti-inflammatory effects through activating AMPK. Therefore, AMPK is emerging as a promising novel target for the development of anti-inflammatory drugs. This review summarized the anti-inflammatory effects of AMPK and the underling molecular mechanisms.
AMP-Activated Protein Kinases ; metabolism ; Homeostasis ; Inflammation ; enzymology ; Metformin ; pharmacology ; NF-kappa B ; antagonists & inhibitors ; Phosphorylation

OBJECTIVE: To investigate the role of platelet-rich plasma (PRP) in inducing the M2 macrophage polarization via regulating AMPK singling pathway. METHODS: The expressions of M1 marker CD11c and M2 marker CD206 in macrophages of blank control group, LPS group, LPS+PRP group, and LPS+PRP+Compound C group were detected by flow cytometry. Western blot was used to observe the effects of PRP on the expression of AMPK-mTOR signaling pathway-related proteins at different times (12 h, 18 h and 24 h) after LPS treatment. RNA interference technology was used to silence the expression of AMPK in macrophages, and the expression of TGF-β protein was subsequently examined by Western blot. RESULTS: LPS significantly reduced the expression of CD206 and increased the expression of CD11c (P <0.05). After the addition of PRP, the expression of CD206 was significantly increased (P <0.05), while the expression of CD11c was significantly decreased (P <0.05). Compared with LPS group, PRP treatment significantly increased the expressions of p-AMPK and p-ULK1 proteins at 12 h, 18 h and 24 h, while significantly decreased the expression of p-mTOR protein (P <0.05). After the addition of AMPK inhibitor Compound C, the expression of CD206 was significantly reduced (P <0.05) and the expression of CD11c was significantly increased compared with LPS+PRP group (P <0.05). After silencing the expression of AMPK in macrophages, the promotion effect of PRP on TGF-β was significantly reduced (P <0.05). CONCLUSION PRP can stimulate the transformation of macrophages to M2 type via AMPK signalling pathway.
Humans ; AMP-Activated Protein Kinases/pharmacology* ; Lipopolysaccharides/pharmacology* ; Macrophages/metabolism* ; Transforming Growth Factor beta/metabolism* ; Platelet-Rich Plasma/metabolism*

AMP-Activated Protein Kinases ; metabolism ; Animals ; Flavonoids ; pharmacology ; Lipid Metabolism ; Liver ; metabolism ; Male ; Rats ; Rats, Sprague-Dawley

Metformin has been used for the treatment of type II diabetes mellitus for decades due to its safety, low cost, and outstanding hypoglycemic effect clinically. The mechanisms underlying these benefits are complex and still not fully understood. Inhibition of mitochondrial respiratory-chain complex I is the most described downstream mechanism of metformin, leading to reduced ATP production and activation of AMP-activated protein kinase (AMPK). Meanwhile, many novel targets of metformin have been gradually discovered. In recent years, multiple pre-clinical and clinical studies are committed to extend the indications of metformin in addition to diabetes. Herein, we summarized the benefits of metformin in four types of diseases, including metabolic associated diseases, cancer, aging and age-related diseases, neurological disorders. We comprehensively discussed the pharmacokinetic properties and the mechanisms of action, treatment strategies, the clinical application, the potential risk of metformin in various diseases. This review provides a brief summary of the benefits and concerns of metformin, aiming to interest scientists to consider and explore the common and specific mechanisms and guiding for the further research. Although there have been countless studies of metformin, longitudinal research in each field is still much warranted.
Humans ; Metformin/pharmacokinetics* ; Diabetes Mellitus, Type 2/metabolism* ; Hypoglycemic Agents/pharmacology* ; AMP-Activated Protein Kinases/metabolism* ; Aging

AMP-activated protein kinase (AMPK) is a key enzyme in the regulation of cellular energy homeostasis. Recent studies demonstrated that AMPK also plays an important role in the modulation of inflammation, an energy-intensive molecular response. The commonly used AMPK activators include 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) and A-769662. In addition, the biological activities of metformin and adiponectin are closely related to activation of AMPK. Numerous studies have shown that these AMPK activators play an effectively protective role in animal models of acute lung injury, asthma, colitis, hepatitis, atherosclerosis and other inflammatory diseases. Therefore, AMPK activators may have promising potential for the prevention and treatment of inflammation related diseases.
AMP-Activated Protein Kinases ; physiology ; Adiponectin ; pharmacology ; Aminoimidazole Carboxamide ; pharmacology ; Animals ; Enzyme Activation ; Inflammation ; enzymology ; Metformin ; pharmacology ; Pyrones ; pharmacology ; Thiophenes ; pharmacology

OBJECTIVES: To determine the potential molecular mechanisms underlying the therapeutic effect of curcumin on hepatocellular carcinoma (HCC) by network pharmacology and experimental in vitro validation. METHODS: The predictive targets of curcumin or HCC were collected from several databases. the identified overlapping targets were crossed with Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses using the Database for Annotation, Visualization, and Integrated Discovery (DAVID) platform. Two of the candidate pathways were selected to conduct an experimental verification. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide tetrazolium (MTT) assay was used to determine the effect of curcumin on the viability of HepG2 and LO2 cells. The apoptosis and autophagy of HepG2 cells were respectively detected by flow cytometry and transmission electron microscopy. Besides, western blot and real-time polymerase chain reaction (PCR) were employed to verify the p53 apoptotic pathway and adenosine 5'-monophosphate (AMP)‍-activated protein kinase (AMPK) autophagy pathway. HepG2 cells were pretreated with pifithrin-‍α (PFT-‍α) and GSK690693 for further investigation. RESULTS: The 167 pathways analyzed by KEGG included apoptosis, autophagy, p53, and AMPK pathways. The GO enrichment analysis demonstrated that curcumin was involved in cellular response to drug, regulation of apoptotic pathway, and so on. The in vitro experiments also confirmed that curcumin can inhibit the growth of HepG2 cells by promoting the apoptosis of p53 pathway and autophagy through the AMPK pathway. Furthermore, the protein and messenger RNA (mRNA) of the two pathways were downregulated in the inhibitor-pretreated group compared with the experimental group. The damage-regulated autophagy modulator (DRAM) in the PFT-‍α-pretreated group was downregulated, and p62 in the GSK690693-pretreated group was upregulated. CONCLUSIONS Curcumin can treat HCC through the p53 apoptotic pathway and the AMPK/Unc-51-like kinase 1 (ULK1) autophagy pathway, in which the mutual transformation of autophagy and apoptosis may occur through DRAM and p62.
AMP-Activated Protein Kinases/pharmacology* ; Apoptosis ; Carcinoma, Hepatocellular/pathology* ; Curcumin/pharmacology* ; Humans ; Liver Neoplasms/pathology* ; Network Pharmacology ; Tumor Suppressor Protein p53/metabolism*

OBJECTIVE: To investigate the effect of emodin on high glucose (HG)-induced podocyte apoptosis and whether the potential anti-apoptotic mechanism of emodin is related to induction of adenosine-monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR)-mediated autophagy in podocytes (MPC5 cells) in vitro. METHODS: MPC5 cells were treated with different concentrations of HG (2.5, 5, 10, 20, 40, 80 and 160 mmol/L), emodin (2, 4, 8 µ mol/L), or HG (40 mmol/L) and emodin (4 µ mol/L) with or without rapamycin (Rap, 100 nmol/L) and compound C (10 µ mol/L). The viability and apoptosis of MPC5 cells were detected using cell counting kit-8 (CCK-8) assay and flow cytometry analysis, respectively. The expression levels of cleaved caspase-3, autophagy marker light chain 3 (LC3) I/II, and AMPK/mTOR signaling pathway-related proteins were determined by Western blot. The changes of morphology and RFP-LC3 fluorescence were observed under microscopy. RESULTS: HG at 20, 40, 80 and 160 mmol/L dose-dependently induced cell apoptosis in MPC5 cells, whereas emodin (4 µ mol/L) significantly ameliorated HG-induced cell apoptosis and caspase-3 cleavage (P<0.01). Emodin (4 µ mol/L) significantly increased LC3-II protein expression levels and induced RFP-LC3-containing punctate structures in MPC5 cells (P<0.01). Furthermore, the protective effects of emodin were mimicked by rapamycin (100 nmol/L). Moreover, emodin increased the phosphorylation of AMPK and suppressed the phosphorylation of mTOR. The AMPK inhibitor compound C (10 µ mol/L) reversed emodin-induced autophagy activation. CONCLUSION Emodin ameliorated HG-induced apoptosis of MPC5 cells in vitro that involved induction of autophagy through the AMPK/mTOR signaling pathway, which might provide a potential therapeutic option for diabetic nephropathy.
Emodin/pharmacology* ; AMP-Activated Protein Kinases/metabolism* ; Podocytes ; Caspase 3/metabolism* ; TOR Serine-Threonine Kinases/metabolism* ; Signal Transduction ; Apoptosis ; Sirolimus/pharmacology* ; Glucose/metabolism* ; Autophagy

This study aims to explore the anti-depression mechanism of Zuojin Pills based on the plasma constituents, network pharmacology, and experimental verification. UHPLC-TOF-MS was used for qualitative analysis of Zuojin Pills-containing serum. Targets of the plasma constituents and the disease were retrieved from PharmMapper and GeneCards. Then the protein-protein interaction(PPI) network was constructed and core targets were screened for GO term enrichment and KEGG pathway enrichment. Cytoscape 3.7.2 was employed construct the &amp;quot;compound-target-pathway&amp;quot; network and the targets and signaling pathways of Zuojin Pills against depression were predicted. CUMS-induced depression mouse model was established to verify the key targets. The results showed that a total of 21 constituents migrating to blood of Zuojin Pills were identified, which were mainly alkaloids. A total of 155 common targets of the constituents and the disease and 67 core targets were screened out. KEGG enrichment and PPI network analysis showed that Zuojin Pills may play a role in the treatment of depression through AMPK/SIRT1, NLRP3, insulin and other targets and pathways. Furthermore, the results of animal experiments showed that Zuojin Pills could significantly improve the depression behaviors of depression, reduce the levels of IL-1β, IL-6 and TNF-α in hippocampus and serum, activate AMPK/SIRT1 signaling, and reduce the protein expression of NLRP3. In conclusion, Zuojin Pills may play a role in the treatment of depression by activating AMPK/SIRT1 signaling pathway, and inhibiting NLRP3 activation and neuroinflammation in the hippocampus of mice.
Animals ; Mice ; Network Pharmacology ; AMP-Activated Protein Kinases ; Chromatography, High Pressure Liquid ; NLR Family, Pyrin Domain-Containing 3 Protein ; Sirtuin 1 ; Drugs, Chinese Herbal/pharmacology* ; Molecular Docking Simulation

BACKGROUNDThe renoprotective mechanisms of adenosine monophosphate (AMP)-activated protein kinase (AMPK) agonist - metformin have not been stated clearly. We hypothesized that metformin may ameliorate inflammation via AMPK interaction with critical inflammatory cytokines. The aim of this study was to observe the effects of metformin on expression of nuclear factor-κB (NF-κB), monocyte chemoattractant protein-1 (MCP-1), intercellular adhesion molecule-1 (ICAM-1) and transforming growth factor-beta 1 (TGF-β1) induced by high glucose (HG) in cultured rat glomerular mesangial cells (MCs).

METHODSMCs were cultured in the medium with normal concentration glucose (group NG, 5.6 mmol/L), high concentration glucose (group HG, 25 mmol/L) and different concentrations of metformin (group M1, M2, M3). After 48-hour exposure, the supernatants and MCs were collected. The expression of NF-κB, MCP-1, ICAM-1, and TGF-β1 mRNA was analyzed by real time polymerase chain reaction. Western blotting was used to detect the expression of AMPK, phospho-Thr-172 AMPK (p-AMPK), NF-κB p65, MCP-1, ICAM-1, and TGF-β1 protein.

RESULTSAfter stimulated by HG, the expression of NF-κB, MCP-1, ICAM-1, TGF-β1 mRNA and protein of MCs in group HG increased significantly compared with group NG (P < 0.05). Both genes and protein expression of NF-κB, MCP-1, ICAM-1, TGF-β1 of MCs induced by high glucose were markedly reduced after metformin treatment in a dose-dependent manner (P < 0.05). The expression of p-AMPK increased with the rising of metformin concentration, presenting the opposite trend, while the level of total-AMPK protein was unchanged with exposure to HG or metformin. Conlusion Metformin can suppress the expression of NF-κB, MCP-1, ICAM-1 and TGF-β1 of glomerular MCs induced by high glucose via AMPK activation, which may partly contribute to its reno-protection.

AMP-Activated Protein Kinases ; metabolism ; Animals ; Cells, Cultured ; Glomerular Mesangium ; cytology ; Glucose ; pharmacology ; Mesangial Cells ; drug effects ; metabolism ; Metformin ; pharmacology ; NF-kappa B ; metabolism ; Rats

To test the hypothesis that AMP-activated protein kinase (AMPK) is possibly the downstream signaling molecule of certain subtypes of adrenergic receptor (AR) in the heart, we evaluated AMPK activation mediated by ARs in H9C2 cells, a rat cardiac source cell line, and rat hearts. The AMPK-alpha subunit and the phosphorylation level of Thr(172)-AMPK-alpha subunit were subjected to Western blot analysis. Osmotic minipumps filled with norepinephrine (NE), phenylephrine (PE) or vehicle [0.01% (W/V) vitamin C solution] were implanted into male Sprague-Dawley rats subcutaneously. The pumps delivered NE or PE continuously at the rate of 0.2 mg/kg per hour. After 7-day infusion, the activity of AMPK was examined following immunoprecipitation with anti-AMPK-alpha antibody. At the cellular level, we found that NE elevated AMPK phosphorylation level in a dose- and time-dependent manner, with the maximal effect at 10 micromol/L NE after 10-minute treatment. This effect was insensitive to propranolol, a specific beta-AR antagonist, but abolished by prazosin, an alpha(1)-AR antagonist, suggesting that alpha(1)-AR but not beta-AR mediated the phosphorylation of AMPK. Moreover, the results from rat models of 7-day-infusion of AR agonists demonstrated that the activity of AMPK was significantly higher in NE (7.4-fold) and PE (6.0-fold) infusion groups than that in the vehicle group (P<0.05, n=6). On the other hand, no obvious cardiac hypertrophy and tissue fibrosis changes were observed in PE-infused rats. Taken together, our results demonstrate that alpha(1)-AR stimulation enhances the activity of AMPK, indicating an important role of alpha(1)-AR stimulation in the regulation of AMPK in the heart. Understanding the activation of AMPK mediated by alpha(1)-AR might have clinical implications in the therapy of heart failure.
AMP-Activated Protein Kinases ; metabolism ; Animals ; Cell Line ; Heart Ventricles ; Male ; Myocardium ; cytology ; metabolism ; Norepinephrine ; pharmacology ; Phenylephrine ; pharmacology ; Phosphorylation ; Rats ; Rats, Sprague-Dawley ; Receptors, Adrenergic, alpha ; physiology