AMPK Levels Research Articles

The effect of myo-inositol supplementation on AMPK/PI3K/AKT pathway and insulin resistance in patients with NAFLD.

Insulin resistance (IR) is the pivotal pathological hit in non-alcoholic fatty liver disease (NAFLD). There is specific attention to combination/conjugated therapies for NAFLD management. As myo-inositol (MI) has been shown to improve IR in animal and human trials, this study aimed to investigate the influence of MI supplementation on glycemic response and IR through AMPK/PI3K/AKT signaling pathway in obese patients with NAFLD. This double-blinded placebo-controlled randomized clinical trial was conducted on 48 obese (BMI = 30-40 kg/m2) patients with NAFLD who were randomly assigned to receiving either MI (4 g/day) or placebo (maltodextrin 4 g/day) group for 8 weeks. Before and after the trial, weight, height, serum glycemic parameters (inc. fasting glucose and insulin) as well as IR indices were assessed. Moreover, the mRNA expression levels of AMPK, AKT, and PDK-1 in peripheral blood mononuclear cells (PBMCs) were determined. MI supplementation resulted in significant increases in the fold changes of AMPK, AKT, and PDK-1 genes (p = .019, p = .049, and p = .029, respectively). Indeed, IR improved in terms of all IR indices in MI group (p < .05) after adjusting for the confounders, apart from quantitative insulin sensitivity check index (QUICKI). The results showed that MI supplementation not only upregulated AMPK, AKT, and PDK-1 mRNA in PBMCs but also improved IR in obese patients with NAFLD.

C-phycocyanin shows neuroprotective effect against rotenone-induced Parkinson’s disease in mice

Objective: To investigate the neuroprotective effect of C-phycocyanin in a mouse model of rotenone-induced Parkinson’s disease. Methods: C-phycocyanin (50 mg/kg, i.p., daily) was administered to rotenone (30 mg/kg, p.o., daily) treated mice for 28 days. Behavioral studies (Y-maze, rotarod, round beam walk, and wire-hang tests) were carried out to assess neurobehavioral deficits. Glutathione and malondialdehyde were determined in both serum and striatal tissue. Molecular proteins (AKT, AMPK, NF-κB, BDNF, and alpha-synuclein) in the striatum were estimated using ELISA. Histopathological analyses (hematoxylin and eosin stainning as well as Nissl staining) were carried out to assess structural abnormalities in the striatum. Results: C-phycocyanin significantly increased BDNF levels and decreased alpha-synuclein levels. It also slightly upregulated AMPK and AKT levels without significant difference compared with the rotenone group. Additionally, rotenone-induced elevated oxidative stress and structural abnormalities in the striatum were markedly mitigated by C-phycocyanin. Conclusions: C-phycocyanin might have potential neuroprotective effects against Parkinson’s disease. Further studies are warranted to verify its efficacy and to understand the molecular mechanisms behind the neuroprotective effects of C-phycocyanin in Parkinson’s disease.

Activated AMP-protein kinase (pAMPK) is overexpressed in human somatotroph pituitary adenomas

IntroductionAMPK (AMP-activated protein kinase) is an enzyme that acts as a metabolic sensor and regulates multiple pathways via phosphorylating proteins in metabolic and proliferative pathways. The aim of this work was to study the activated cellular AMPK (phosphorylated-AMPK at Thr172, pAMPK) levels in pituitary tumor samples from patients with sporadic and familial acromegaly, as well as in samples from normal human pituitary gland. MethodsWe studied pituitary adenoma tissue from patients with sporadic somatotroph adenomas, familial acromegaly with heterozygote germline variants in the aryl hydrocarbon receptor interacting protein (AIP) gene (p.Q164*, p.R304* and p.F269_H275dup) and autopsy from normal pituitary glands without structural alterations. ResultsCellular levels of pAMPK were significantly higher in patients with sporadic acromegaly compared to normal pituitary glands (p < 0.0001). Tissues samples from patients with germline AIP mutations also showed higher cellular levels of pAMPK compared to normal pituitary glands. We did not observe a significant difference in cellular levels of pAMPK according to the cytokeratin (CAM5.2) pattern (sparsely or densely granulated) for tumor samples of sporadic acromegaly. ConclusionOur data show, for the first time in human cells, an increase of cellular levels of pAMPK in sporadic somatotropinomas, regardless of cytokeratin pattern, as well as in GH-secreting adenomas from patients with germline AIP mutations.

Xinbao Pill ameliorates heart failure via regulating the SGLT1/AMPK/PPARα axis to improve myocardial fatty acid energy metabolism

BackgroundHeart failure (HF) is characterized by a disorder of cardiomyocyte energy metabolism. Xinbao Pill (XBW), a traditional Chinese medicine formulation integrating “Liushen Pill” and “Shenfu Decoction,” has been approved by China Food and Drug Administration for the treatment of HF for many years. The present study reveals a novel mechanism of XBW in HF through modulation of cardiac energy metabolism.Methods In vivo, XBW (60, 90, 120 mg/kg/d) and fenofibrate (100 mg/kg/d) were treated for six weeks in Sprague–Dawley rats that were stimulated by isoproterenol to induce HF. Cardiac function parameters were measured by echocardiography, and cardiac pathological changes were assessed using H&E, Masson, and WGA staining. In vitro, primary cultured neonatal rat cardiomyocytes (NRCMs) were induced by isoproterenol to investigate the effects of XBW on myocardial cell damage, mitochondrial function and fatty acid energy metabolism. The involvement of the SGLT1/AMPK/PPARα signalling axis was investigated.ResultsIn both in vitro and in vivo models of ISO-induced HF, XBW significantly ameliorated cardiac hypertrophy cardiac fibrosis, and improved cardiac function. Significantly, XBW improved cardiac fatty acid metabolism and mitigated mitochondrial damage. Mechanistically, XBW effectively suppressed the expression of SGLT1 protein while upregulating the phosphorylation level of AMPK, ultimately facilitating the nuclear translocation of PPARα and enhancing its transcriptional activity. Knockdown of SGLT1 further enhanced cardiac energy metabolism by XBW, while overexpression of SGLT1 reversed the cardio-protective effect of XBW, highlighting that SGLT1 is probably a critical target of XBW in the regulation of cardiac fatty acid metabolism.ConclusionsXBW improves cardiac fatty acid energy metabolism to alleviate HF via SGLT1/AMPK/PPARα signalling axis.

Glucose uptake in trophoblasts of GDM mice is regulated by the AMPK-CLUT3 signaling pathway.

GDM, as a metabolic disease during pregnancy, regulates GLUT3 translocation by AMPK, thereby affecting glucose uptake in trophoblasts. It provides a new research idea and therapeutic target for alleviating intrauterine hyperglycemia in GDM. STZ was used to construct GDM mice, inject AICAR into pregnant mice, and observe fetal and placental weight; flow cytometry was employed for the detection of glucose uptake by primary trophoblast cells; immunofluorescence was applied to detect the localization of GLUT3 and AMPK in placental tissue; Cocofal microscope was used to detect the localization of GLUT3 in trophoblast cells;qRT-PCR and Western blot experiments were carried out to detect the expression levels of GLUT3 and AMPK in placental tissue; CO-IP was utilized to detect the interaction of GLUT3 and AMPK. Compared with the normal pregnancy group, the weight of the fetus and placenta of GDM mice increased (P < 0.001), and the ability of trophoblasts to take up glucose decreased (P < 0.001). In addition, AMPK activity in trophoblasts and membrane localization of GLUT3 in GDM mice were down-regulated compared with normal pregnant mice (P < 0.05). There is an interaction between GLUT3 and AMPK. Activating AMPK in trophoblasts can up-regulate the expression of GLUT3 membrane protein in trophoblasts of mice (P < 0.05) and increase the glucose uptake of trophoblasts (P < 0.05). We speculate thatinhibition of AMPK activity in GDM mice results in aberrant localization of GLUT3, which in turn attenuates glucose uptake by placental trophoblast cells. AICAR activates AMPK to increase the membrane localization of GLUT3 and improve the glucose uptake capacity of trophoblasts.

Chromium and Methionine Effects on Amino Acid Uptake, Gene Expression, and Protein Abundance in Bovine Satellite Cells

The objective of the study was to evaluate the effects of chromium (Cr) and methionine on myogenic gene expression, GLUT4 and insulin receptor (IR) synthesis, and amino acid uptake in differentiated bovine satellite cells. Cells were treated with 0, 1, or 10 &amp;mu;M of chromium acetate (CrAc) and 0, 1, or 10 mg/mL of methionine, with cells utilized for the amino acid assay receiving 0.1 &amp;mu;M instead of 1 &amp;mu;M of CrAc. The addition of 10 &amp;mu;M of Cr tended to downregulate AMPK&amp;alpha; mRNA gene expression (P&amp;nbsp;&amp;lt; 0.1). Myogenin was impacted by methionine and CrAc with high doses and low doses upregulating expression (P&amp;nbsp;&amp;lt; 0.01). The ratio and protein levels of AMPK&amp;alpha; to pAMPK&amp;alpha;, GLUT4, and IR abundance were not affected (P&amp;nbsp;&amp;gt; 0.1). Increase in time decreased concentrations of leucine, isoleucine, threonine, methionine, phenylalanine, glutamine, ornithine, lysine, and cysteine (P&amp;nbsp;&amp;lt; 0.01) in conditioned media. Over time, alanine increased (P&amp;nbsp;&amp;lt; 0.01). Methionine inclusion increased alanine, proline, glutamic acid, ornithine, and tryptophan concentrations, as well as decreased leucine, isoleucine, and cysteine (P&amp;nbsp;&amp;lt; 0.01). CrAc only affected glutamine and tryptophan, which both increased with CrAc dose, whereas alanine decreased (P&amp;nbsp;&amp;lt; 0.01). Methionine decreased over time within the 10 mg/mL group (P&amp;nbsp;&amp;lt; 0.01). Tryptophan was generally unaffected but decreased in the 0 mg/mL group at 48 h. Cysteine decreased with a decreased dosage of CrAc at 24 h (P &amp;lt; 0.01). Lysine was generally unaffected by this interaction (P&amp;nbsp;&amp;gt; 0.1), with the exception of the 0.1 &amp;mu;M treatment group at 24 h being higher (P&amp;nbsp;&amp;lt; 0.01). CrAc affected the uptake of alanine, glutamine, and tryptophan (P&amp;nbsp;&amp;lt; 0.01). Methionine inclusion increased alanine, proline, glutamic acid, ornithine, and tryptophan, as well as decreased leucine, isoleucine, and cystine (P &amp;lt; 0.01). Increased time saw a significant decrease in leucine, isoleucine, threonine, methionine, phenylalanine, glutamine, ornithine, lysine, and cystine (P&amp;nbsp;&amp;lt; 0.01) and an increase in alanine (P &amp;lt; 0.01).

Gouqi-derived nanovesicles (GqDNVs) inhibited dexamethasone-induced muscle atrophy associating with AMPK/SIRT1/PGC1α signaling pathway

With the increasing trend of global aging, sarcopenia has become a significant public health issue. Goji berry, also known as “Gou qi zi” in China, is a traditional Chinese herb that can enhance the structure and function of muscles and bones. Otherwise, previous excellent publications illustrated that plant-derived exosome-like nanoparticles can exert good bioactive functions in different aging or disease models. Thus, we issued the hypothesis that Gouqi-derived nanovesicles (GqDNVs) may also have the ability to improve skeletal muscle health, though the effect and its mechanism need to be explored. Hence, we have extracted GqDNVs from fresh berries of Lycium barbarum L. (goji) and found that the contents of GqDNVs are rich in saccharides and lipids. Based on the pathway annotations and predictions in non-targeted metabolome analysis, GqDNVs are tightly associated with the pathways in metabolism. In muscle atrophy model mice, intramuscular injection of GqDNVs improves the cross-sectional area of the quadriceps muscle, grip strength and the AMPK/SIRT1/PGC1α pathway expression. After separately inhibiting AMPK or PGC1α in C2C12 cells with dexamethasone administration, we have found that the activated AMPK plays the chief role in improving cell proliferation induced by GqDNVs. Furthermore, the energy-targeted metabolome analysis in the quadriceps muscle demonstrates that the GqDNVs up-regulate the metabolism of amino sugar and nucleotide sugar, autophagy and oxidative phosphorylation process, which indicates the activation of muscle regeneration. Besides, the Spearman rank analysis shows close associations between the quality and function of skeletal muscle, metabolites and expression levels of AMPK and SIRT1. In this study, we provide a new founding that GqDNVs can improve the quality and function of skeletal muscle accompanying the activated AMPK/SIRT1/PGC1α signaling pathway. Therefore, GqDNVs have the effect of anti-aging skeletal muscle as a potential adjuvant or complementary method or idea in future therapy and research.Graphical

The interaction between 20-hydroxyecdysone and AMPK through PI3K activation in Chinese mitten crab, Eriocheir sinensis

In crustaceans, the steroid hormone 20-hydroxyecdysone (20E) initiates molting, and the molting process is also regulated by energy metabolism. AMPK is an energy sensor and plays a critical role in systemic energy balance. Here, the regulatory mechanism in the interaction between 20E and AMPK was investigated in Chinese mitten crab, Eriocheir sinensis. The results showed that the 20E concentration and the mRNA expression levels of 20E receptors in hepatopancreas were down-regulated post AMPK activator (AICAR) treatment, and were up-regulated after AMPK inhibitor (Compound C) injection in crabs. Besides, the molt-inhibiting hormone (MIH) gene expression in eyestalk showed the opposite patterns in response to the AICAR and Compound C treatment, respectively. Further investigation found that there was a significant reduction in 20E concentration post PI3K inhibitor (LY294002) treatment, and the phosphorylation level of PI3K was increased in hepatopancreas after AMPK inhibitor injection. On the other hand, the positive regulation of PI3K-mediated activation of AMPK was also observed, the phosphorylation levels of AMPKα, AMPKβ and PI3K in hepatopancreas were significantly increased post 20E injection. In addition, the phosphorylation levels of AMPKα and AMPKβ induced by 20E were decreased after the injection of PI3K inhibitor. Taken together, these results suggest that the regulatory cross-talk between 20E and AMPK is likely to act through PI3K pathway in E. sinensis, which appeared to be helpful for a better understanding in molting regulation.

Endothelin-1 stimulated human preadipocyte growth through the AMPK, ERK, cJUN, PKC, and STAT3 pathways

High level of plasma endothelin (ET)-1 was noticed in obesity, and it was found to regulate adipogenesis and the endocrine activity of fat cells. However, relatively little is known about the ET-1 signaling pathway in preadipocyte growth. Our previous reports have shown that ET-1 and ET-3 stimulated murine 3T3-L1 preadipocyte growth through different kinase signaling cascades with ET type A receptor (ETAR) but not ETBR dependency. In this study, the hypothesis arose that ET-1 may regulate human visceral white preadipocyte growth through the AMPK, ERK, cJUN, PKC, and STAT3 pathways with ET receptor-specific dependency. As indicated by an increased number of cells and greater conversion of 3-4,5-dimethylthiazol-2-yl-2,5 diphenyl tetrazolium bromide (MTT) to formazan crystals by living cells, the stimulation of human preadipocyte growth by ET-1 depended on concentration. Neither ET-2 nor ET-3 stimulated human preadipocyte growth. When signaling pathways were examined, ET-1 signaling stimulated phosphorylation of AMPK, ERK, cJUN, PKC, and STAT3, proteins but not AKT, JNK, or p38 MAPK. Treatment with an ETAR antagonist, such as BQ610, or an ETBR antagonist, such as BQ788, blocked the ET-1-induced increase in cell growth and phosphorylated levels of AMPK, PKC, and STAT3 proteins. However, treatment with BQ788 but not BQ610 blocked the ET-1-increased levels of ERK and c-JUN protein phosphorylation. In addition, pretreatment with specific inhibitors of AMPK (compound C), ERK1/2 (U0126), JNK (SP600125), JAK2/STAT3 (AG490), or PKC (Ro318220) prevented the ET-1-induced increase in cell growth and reduced the ET-1-stimulated phosphorylation of AMPK, ERK1/2, c-JUN, STAT3, and PKC. However, neither the p38 MAPK antagonist nor the ceramide synthase inhibitor altered the effect of ET-1. The results indicate that the target molecules of ETAR and ETBR signaling pathways transducing ET-1 growth signals in human visceral preadipocytes can be similar (e.g., AMPK, JAK2/STAT3, and PKC) or different (e.g., ERK1/2 and JNK/c-JUN). This work was supported in part by the National Science and Technology Council, Taiwan, Grant NSTC 112-2320-B-008-001 to YHK and the Taoyuan Armed Forces General Hospital, Taiwan, Grant AFTGH to PJH, CCK, LJS, and YHK. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

An 8-Week study on the effects of high and Moderate-Intensity interval exercises on mitochondrial MOTS-C changes and their relation to metabolic markers in male diabetic sand rats

Mitochondrial dysfunction is a significant feature of type 2 diabetes. MOTS-C, a peptide derived from mitochondria, has positive effects on metabolism and exercise capacity. This study explored the impact of high and moderate-intensity interval exercises on mitochondrial MOTS-C alterations and their correlation with metabolic markers in male diabetic sand rats. Thirty male sand rats were divided into six groups: control, MIIT, DM + HIIT, DM + MIIT, DM, and HIIT (5 rats each). Diabetes was induced using a high-fat diet (HFD) combined with streptozotocin (STZ). The Wistar sand rats in exercise groups underwent 8 weeks of interval training of varying intensities. Post sample collection, protein expressions of PCG-1a, AMPK, and GLUT4 were assessed through Western blot analysis, while MOTS-C protein expression was determined using ELISA. Both exercise intensity and diabetes significantly affected the levels of PCG-1a, MOTS-C, GLUT4 proteins, and insulin resistance (p < 0.001). The combined effect of diabetes status and exercise intensity on these levels was also significant (p < 0.001). However, the diabetes effect varied when comparing high-intensity to moderate-intensity exercise. The moderate-intensity exercise group with diabetes showed higher levels of PCG-1a, MOTS-C, and GLUT4 proteins and reduced insulin resistance levels (p < 0.001). Exercise intensity (p = 0.022) and diabetes (p = 0.008) significantly influenced AMPK protein levels. The interplay between diabetes status and exercise intensity on AMPK protein levels was noteworthy, with the moderate-intensity diabetes group exhibiting higher AMPK levels than the high-intensity diabetes group (p < 0.001). In conclusion, exercise elevates the levels of PCG-1a, MOTS-C, GLUT4, and AMPK proteins, regulating insulin resistance in diabetic sand rats. Given the AMPK-MOTS-C mitochondrial pathway's mechanisms, interval exercises might enhance the metabolic rates and general health of diabetic rodents.

Dihydromyricetin ameliorates hepatic steatosis and insulin resistance via AMPK/PGC-1α and PPARα-mediated autophagy pathway

BackgroundDihydromyricetin (DHM), a flavonoid compound of natural origin, has been identified in high concentrations in ampelopsis grossedentata and has a broad spectrum of biological and pharmacological functions, particularly in regulating glucose and lipid metabolism. The objective of this research was to examine how DHM affected nonalcoholic fatty liver disease (NAFLD) and its underlying mechanisms involved in the progression of NAFLD in a rat model subjected to a high-fat diet (HFD). Additionally, the study examines the underlying mechanisms in a cellular model of steatohepatitis using palmitic acid (PA)-treated HepG2 cells, with a focus on the potential correlation between autophagy and hepatic insulin resistance (IR) in the progress of NAFLD.MethodsSD rats were exposed to a HFD for a period of eight weeks, followed by a treatment with DHM (at doses of 50, 100, and 200 mg·kg−1·d−1) for additional six weeks. The HepG2 cells received a 0.5 mM PA treatment for 24 h, either alone or in conjunction with DHM (10 µM). The histopathological alterations were assessed by the use of Hematoxylin–eosin (H&E) staining. The quantification of glycogen content and lipid buildup in the liver was conducted by the use of PAS and Oil Red O staining techniques. Serum lipid and liver enzyme levels were also measured. Autophagic vesicle and autolysosome morphology was studied using electron microscopy. RT-qPCR and/or western blotting techniques were used to measure IR- and autophagy-related factors levels.ResultsThe administration of DHM demonstrated efficacy in ameliorating hepatic steatosis, as seen in both in vivo and in vitro experimental models. Moreover, DHM administration significantly increased GLUT2 expression, decreased G6Pase and PEPCK expression, and improved IR in the hepatic tissue of rats fed a HFD and in cells exhibiting steatosis. DHM treatment elevated Beclin 1, ATG 5, and LC3-II levels in hepatic steatosis models, correlating with autolysosome formation. The expression of AMPK levels and its downstream target PGC-1α, and PPARα were decreased in HFD-fed rats and PA-treated hepatocytes, which were reversed through DHM treatment. AMPK/ PGC-1α and PPARα knockdown reduced the impact of DHM on hepatic autophagy, IR and accumulation of hepatic lipid.ConclusionsOur findings revealed that AMPK/ PGC-1α, PPARα-dependent autophagy pathways in the pathophysiology of IR and hepatic steatosis has been shown, suggesting that DHM might potentially serve as a promising treatment option for addressing this disease.Graphical

Sirt3 Protects Retinal Pigment Epithelial Cells From High Glucose-Induced Injury by Promoting Mitophagy Through the AMPK/mTOR/ULK1 Pathway.

The regulation of mitophagy by Sirt3 has rarely been studied in ocular diseases. In the present study, we determined the effects of Sirt3 on AMPK/mTOR/ULK1 signaling pathway-mediated mitophagy in retinal pigment epithelial (RPE) cells in a high glucose environment. The mRNA expression levels of Sirt3, AMPK, mTOR, ULK1, and LC3B in RPE cells under varying glucose conditions were measured by real-time polymerase chain reaction (RT-PCR). The expressions of Sirt3, mitophagy protein, and AMPK/mTOR/ULK1 signaling pathway-related proteins were detected by Western blotting. Lentivirus (LV) transfection mediated the stable overexpression of Sirt3 in cell lines. The experimental groups were NG (5.5mM glucose), hypertonic, HG (30mM glucose), HG + LV-GFP, and HG + LV-Sirt3. Western blotting was performed to detect the expressions of mitophagy proteins and AMPK/mTOR/ULK1-related proteins in a high glucose environment during the overexpression of Sirt3. Reactive oxygen species (ROS) production in a high glucose environment was measured by DCFH-DA staining. Mitophagy was detected by labeling mitochondria and lysosomes with MitoTracker and LysoTracker probes, respectively. Apoptosis was detected by flow cytometry. Sirt3 expression was reduced in the high glucose group, inhibiting the AMPK/mTOR/ULK1 pathway, with diminished mitophagy and increased intracellular ROS production. The overexpression of Sirt3, increased expression of p-AMPK/AMPK and p-ULK1/ULK1, and decreased expression of p-mTOR/mTOR inhibited cell apoptosis and enhanced mitophagy. Sirt3 protected RPE cells from high glucose-induced injury by activating the AMPK/mTOR/ULK1 signaling pathway. By identifying new targets of action, we aimed to establish effective therapeutic targets for diabetic retinopathy treatment.

Abstract 2349: A phenotypic model for cancer metabolism

Abstract Understanding cancer metabolism is crucial for deciphering various cancer hallmarks, including metastasis and immunosuppression. This study investigated the intricate interplay of catabolic processes involving glucose, fatty acids, and glutamine in cancer cells. Recent evidence highlights the dual reliance of cancer cells on glycolysis and oxidative phosphorylation (OXPHOS), challenging the simplistic Warburg effect. Fatty acids and glutamine also emerged as vital contributors to tumorigenesis. Despite these advances, a comprehensive model encompassing both catabolic and anabolic processes, especially glutamine metabolism, is lacking. A metabolic network model integrates catabolic and anabolic modes for glucose, fatty acids, and glutamine, incorporating genetic regulation involving AMPK, HIF-1, and MYC. Equations capture the temporal dynamics of regulatory proteins (pAMPK and HIF-1) and metabolites (mtROS and noxROS), modeling metabolic flux for glucose and glutamine uptake, fatty acid, acetyl-CoA utilization, and activities of glucose oxidation, glycolysis, and FAO. The regulatory network outlines competition for resources, gene regulation, chemical intermediates, cross-regulation among gene regulators, and regulation of metabolic ingredient uptake. The phenotypic model focusing on AMPK, HIF-1, and MYC reveals metabolic states: OXPHOS (O), glycolysis (W), hybrid (W/O), and low/low, characterized by varying levels of AMPK and HIF-1, influencing pathway activities and anabolic processes. Parameter randomization analysis shows state robustness, especially in MYC overexpressing cancer cells. Analyzing TCGA data reveals differential expression of glutamine metabolism genes. The "W" state exhibits enhanced glutamine uptake, the "O" state heightened glutamine oxidation, and the "W/O" state displays both, aligning with the model's predictions. Bifurcation analyses of AMPK, HIF1, and MYC shed light on state stability and transitions, providing insights into regulatory mechanisms. The low/low phenotype, inactive in both OXPHOS and glycolysis, raises questions about significance and therapy resistance. The study explores this phenotype further, unraveling molecular underpinnings and therapy resistance implications. A deeper understanding could reveal novel therapeutic targets, enhancing comprehension of cancer cell behavior. This study introduces a minimal network model capturing essential features of cancer metabolism, replicating experimental observations of metabolic heterogeneity. The model predicts diverse cancer cell phenotypes based on MYC expression levels, emphasizing the importance of considering both catabolic and anabolic processes. Citation Format: Javier Villela-Castrejon, Jason T. George, Dongya Jia, Herbert Levine, José N. Onuchic, Benny Abraham Kaipparettu. A phenotypic model for cancer metabolism [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2349.

Cafestol inhibits colon cancer cell proliferation and tumor growth in xenograft mice by activating LKB1/AMPK/ULK1-dependent autophagy

Chemotherapy failure in colorectal cancer patients is the major cause of recurrence and poor prognosis. As a result, there is an urgent need to develop drugs that have a good chemotherapy effect while also being extremely safe. In this study, we found cafestol inhibited colon cancer growth and HCT116 proliferation in vivo and in vitro, and improved the composition of intestinal flora. Further metabolomic data showed that autophagy and AMPK pathways were involved in the process of cafestol's anti-colon cancer effects. The functional validation studies revealed that cafestol increased autophagy vesicles and LC3B-II levels. The autophagic flux induced by cafestol was prevented by using BafA1. The autophagy inhibitor 3-MA blocked the cafestol-induced increase in LC3B-II and cell proliferation inhibition. Then we found that cafestol induced the increased expressions of LKB1, AMPK, ULK1, p-LKB1, p-AMPK, and p-ULK1 proteins in vivo and in vitro. Using the siRNA targeted to the Lkb1 gene, the levels of AMPK, ULK1, and LC3B-II were suppressed under cafestol treatment. These results indicated that the effect of cafestol is through regulating LKB1/AMPK/ULK1 pathway-mediated autophagic death. Finally, a correlation matrix of the microbiome and autophagy-related proteins was conducted. We found that cafestol-induced autophagic protein expression was positively correlated with the beneficial intestinal bacteria (Muribaculaceae, Bacteroides, Prevotellacece, and Alloprevotella) and negatively correlated with the hazardous bacteria. Conclusions: This study found that cafestol inhibited colon cancer in vitro and in vivo by the mechanism that may be related to LKB1/AMPK/ULK1 pathway-mediated autophagic cell death and improved intestinal microenvironment.

Bufei Yishen formula protects the airway epithelial barrier and ameliorates COPD by enhancing autophagy through the Sirt1/AMPK/Foxo3 signaling pathway

ObjectBufei Yishen formula (BYF), a traditional Chinese medicine alleviates COPD symptoms and suppresses airway epithelial inflammation. In this study, we determined whether BYF protects the airway epithelial barrier from destruction in COPD rats.MethodsThe protective effects of BYF on the airway epithelial barrier were examined in a rat COPD model. BEAS-2B epithelial cells were exposed to cigarette smoke extract (CSE) to determine the effect of BYF on epithelial barrier function. Transcriptomic and network analyses were conducted to identify the protective mechanisms.ResultsOral BYF reduced the severity of COPD in rats by suppressing the decline in lung function, pathological changes, inflammation, and protected airway epithelial barrier function by upregulating apical junction proteins, including occludin (OCLN), zonula occludens (ZO)-1, and E-cadherin (E-cad). BYF treatment reduced epithelial permeability, and increased TEER as well as the apical junction proteins, OCLN, ZO-1, and E-cad in BEAS-2B cells exposed to CSE. Furthermore, 58 compounds identified in BYF were used to predict 421 potential targets. In addition, the expression of 572 differentially expressed genes (DEGs) was identified in CSE-exposed BEAS-2B cells. A network analysis of the 421 targets and 572 DEGs revealed that BYF regulates multiple pathways, of which the Sirt1, AMPK, Foxo3, and autophagy pathways may be the most important with respect to protective mechanisms. Moreover, in vitro experiments confirmed that nobiletin, one of the active compounds in BYF, increased apical junction protein levels, including OCLN, ZO-1, and E-cad. It also increased LC3B and phosphorylated AMPK levels and decreased the phosphorylation of FoxO3a.ConclusionsBYF protects the airway epithelial barrier in COPD by enhancing autophagy through regulation of the SIRT1/AMPK/FOXO3 signaling pathway.

Evaluation of the wound healing effect of Nishamalaki, an Ayurvedic formulation comprising Curcuma longa and Phyllanthus emblica in aging rats

BackgroundThere are very few drugs available for healing wounds in the aged population, which is more prone to chronic cutaneous wounds that are particularly hard to heal and require a long healing process. This study which deals with age-related wound healing, investigates the healing effect of Nishamalaki, a classic antidiabetic Ayurvedic formulation comprising turmeric (Curcuma longa) and Indian gooseberry (Phyllanthus emblica), on cutaneous wounds in aging rats.MethodsRats with excision wounds of 7 mm created on their dorsal side received Nishamalaki (500 mg/kg p.o) daily, or a combination of Nishamalaki (500 mg/kg p.o) with 1% Nishamalaki gel applied on the wound or the reference standard metformin (2 μmol) applied on the wound daily till the scabs fell off.ResultsAll treatments enhanced the rate of formation of granulation tissue and wound contraction. All treated rats showed lower blood glucose levels compared with their 1st-day values and significantly lower blood glucose levels when compared with the Aged Control rats. A significant restoration of the aging-depleted L-hydroxyproline, hexosamine, ascorbic acid, PDGF, AMPK, and mTOR levels, and attenuation of the aging-elevated IL-6 and TNF-α levels was elicited by all treatments. The treatments significantly restored the aging-depleted endogenous antioxidants. The Nishamalaki combination treatment of the oral extract and topical gel displayed a better wound-healing effect than the oral treatment alone. The histopathological studies on skin ulceration, hair follicles, granulation tissue, and collagen fiber formation of the wound tissues corroborated the biochemical findings.ConclusionCurcumin and other antioxidant polyphenolic components of Nishamalaki may be responsible for its wound-healing effect. For the first time, the present study has investigated the action of PDGF, AMPK, and mTOR on cutaneous wounds. They seem to be acting together to promote wound healing and repair.Graphical

β2-Adrenoceptors activation regulates muscle trophic-related genes following acute resistance exercise in mice.

Resistance exercise (RE) training and pharmacological stimulation of β2-Adrenoceptors (β2-ARs) alone can promote muscle hypertrophy and prevent muscle atrophy. Although the activation of the sympathetic nervous system (SNS) is a well-established response during RE, the physiological contribution of the endogenous catecholamines and β2-ARs to the RE-induced changes on skeletal muscle protein metabolism remains unclear. This study investigated the effects of the β2-ARs blockade on the acute molecular responses induced by a single bout of RE in rodent skeletal muscles. Male C57BL6/J mice were subjected to a single bout of progressive RE (until exhaustion) on a vertical ladder under β2-AR blockade with ICI 118,551 (ICI; 10mgkg-1, i. p.), or vehicle (sterile saline; 0.9%, i. p.), and the gene expression was analyzed in gastrocnemius (GAS) muscles by qPCR. We demonstrated that a single bout of RE acutely increased the circulating levels of stress-associated hormones norepinephrine (NE) and corticosterone (CORT), as well as the muscle phosphorylation levels of AMPK, p38 MAPK and CREB, immediately after the session. The acute increase in the phosphorylation levels of CREB was followed by the upregulation of CREB-target genes Sik1, Ppargc1a and Nr4a3 (a central regulator of the acute RE response), 3h after the RE session. Conversely, β2-AR blockade reduced significantly the Sik1 and Nr4a3 mRNA levels in muscles of exercised mice. Furthermore, a single bout of RE stimulated the mRNA levels of the atrophic genes Map1lc3b and Gabarapl1 (autophagy-related genes) and Mstn (a well-known negative regulator of muscle growth). Unexpectedly, the gene expression of Igf-1 or Il-6 were not affected by RE, while the atrophic genes Murf1/Trim63 and Atrogin-1/Mafbx32 (ubiquitin-ligases) were increased only in muscles of exercised mice under β2-AR blockade. Interestingly, performing a single bout of RE under β2-AR blockade increased the mRNA levels of Mstn in muscles of exercised mice. These data suggest that β2-ARs stimulation during acute RE stimulates the hypertrophic gene Nr4a3 and prevents the overexpression of atrophic genes such as Mstn, Murf1/Trim63, and Atrogin-1/Mafbx32 in the first hours of postexercise recovery, indicating that he SNS may be physiologically important to muscle adaptations in response to resistance training.

Calorie restriction mimetic, resveratrol, attenuates hepatic ischemia and reperfusion injury through enhancing efferocytosis of macrophages via AMPK/STAT3/S1PR1 pathway

Calorie restriction (CR) mimetic, resveratrol (RSV), has the capacity of promoting phagocytosis. However, its role in hepatic ischemia and reperfusion injury (HIRI) remains poorly understood. This study aimed to investigate the effect of RSV on alleviating HIRI and explore the underlying mechanisms. RSV was intraperitoneally injected in mice HIRI model, while RSV was co-incubated with culture medium for 24 h in RAW 264.7 cells and kupffer cells. Macrophage efferocytosis was assessed by immunostaining of PI and F4/80. The clearance of apoptotic neutrophils in the liver was determined by immunostaining of Ly6-G and cleaved-caspase-3. HE staining, Suzuki's score, serum levels of ALT, AST, TNF-α and IL-1β were analyzed to evaluate HIRI. The efferocytosis inhibitor, Cytochalasin D, was utilized to investigate the effect of RSV on HIRI. Western blot was employed to measure the levels of AMPKα, phospho-AMPKα, STAT3, phospho-STAT3 and S1PR1. SiSTAT3 and inhibitors targeting AMPK, STAT3 and S1PR1, respectively, were used to confirm the involvement of AMPK/STAT3/S1PR1 pathway in RSV-mediated efferocytosis and HIRI. RSV facilitated the clearance of apoptotic neutrophils and attenuated HIRI, which was impeded by Cytochalasin D. RSV boosted macrophage efferocytosis by up-regulating the levels of phospho-AMPKα, phospho-STAT3 and S1PR1, which was reversed by AMPK, STAT3 and S1PR1 inhibitors, respectively. Inhibition of STAT3 suppressed RSV-induced clearance of apoptotic neutrophils and exacerbated HIRI. CR mimetic, RSV, alleviates HIRI by promoting macrophages efferocytosis through AMPK/STAT3/S1PR1 pathway, providing valuable insights into the mechanisms underlying the protective effects of CR on attenuating HIRI.

Lipid regulation of protocatechualdehyde and hydroxysafflor yellow A via AMPK/SREBP2/PCSK9/LDLR signaling pathway in hyperlipidemic zebrafish

The consumption of a high-cholesterol diet is known to cause hyperlipidemia, which is one of the main risk factors for cardiovascular disease. Protocatechualdehyde (PCA) and hydroxysafflor yellow A (HSYA) are the active components of Salvia miltiorrhiza and safflower, respectively. However, their exact mechanism is still unclear. The aim of this study is to investigate its effects on lipid deposition and liver damage in hyperlipidemic zebrafish and its mechanism of anti-hyperlipidemia. The results showed that the use of PCA and HSYA alone and in combination can improve lipid deposition, slow behavior, abnormal blood flow and liver tissue damage, and the combined use is more effective. Further RT-qPCR results showed that PCA + HSYA can regulate the mRNA levels of PPAR-γ, SREBP2, SREBP1, HMGCR, PCSK9, mTOR, C/EBPα, LDLR, AMPK, HNF-1α and FoxO3a. The PCA + HSYA significantly improves lipid deposition and abnormal liver function in hyperlipidemic zebrafish larvae, which may be related to the AMPK/SREBP2/PCSK9/LDLR signaling pathway.

Effects of phosphorus and fenofibrate on lipid deposition, mitochondrial function and protein synthesis in obscure puffer (Takifugu obscurus)

This study aimed to investigate the effects of phosphorus (P) restriction and fenofibrate (F) on lipid deposition, mitochondrial function and protein synthesis in obscure puffer using in vivo and in vitro studies. In vivo, healthy fish with an initial body weight of 18.21 ± 0.04 g were fed three diets supplemented with different P and fenofibrate contents for 10 weeks: Control (5.3 g/kg P), P0 (0 g/kg P) and P0 + F (0 g/kg P and 3.5 g/kg F). The results indicated that P0 treatment significantly reduced weight gain rate and protein deposition, but increased body lipid accumulation, hepatic lipid droplets and serum triglyceride and cholesterol content (P < 0.05). However, P0 + F treatment reversed these. Furthermore, P0 treatment was found to inhibit the mRNA levels of pparα, lpl and cyp7a1, whereas P0 + F treatment significantly increased the expression levels of these genes. In vitro, primary hepatocytes were cultured for 48 h in three different culture media: Control (normal DMEM medium), P0 (DMEM without P), and P0 + F (DMEM without P + 200 mM F). The results showed that P0 significantly decreased the mRNA and protein expression levels of Pparα (P < 0.05), and P0 + F up-regulated mRNA expression levels of pparα compared with P0 group (P < 0.05). Furthermore, P0 inhibited the expression levels of genes associated with fatty acid β-oxidation (cpt1 and acox1) and transport (cd36), but elevated the expression levels of genes related to lipid synthesis (fas, me, g6pd and dgat1) and cholesterol synthesis (hmgcr) (P < 0.05). However, P0 + F reversed these effects. P0 decreased mitochondrial abundance, membrane potential and ATP content, increased the mRNA expression level of ampk and 4epb1 and inhibited the mRNA expression of pgc1-α and the protein expression of mTOR and S6k (P < 0.05), whereas P0 + F increased mitochondrial abundance and membrane potential, increased mtor mRNA expression and inhibited 4ebp1 mRNA expression. Overall, this study suggests that P deficiency leads to lipid and cholesterol accumulation and impaired growth in fish, and fenofibrate can alleviate these effects by improving lipid and cholesterol metabolism, mitochondrial function, and protein synthesis.