AMP-activated Protein Kinase Pathway Research Articles

Emodin-based Regulation and Control of Serum Complement C5a, Oxidative Stress, and Inflammatory Responses in Rats with Urosepsis via AMPK/SIRT1

Emodin, derived from Rheum officinale and aloe, is known for its diverse benefits such as anti-inflammatory, antioxidant, and antibacterial properties. Currently, the impact of emodin on urosepsis is unclear. This study aims to investigate the mechanism of action of emodin in urosepsis. Peripheral blood mononuclear cells (PBMCs) were purchased from Cloud-Clone Animal Inc. and treated with emodin. Cell viability and the lactate dehydrogenase (LDH) level were then assessed. In a separate experiment, a urosepsis model was established in Sprague Dawley rats which were subsequently treated with emodin. The levels of oxidative stress-related factors, serum complements and inflammatory factors were measured using commercial kits. Blood urea nitrogen and serum creatinine levels were determined using a fully automatic biochemical analyzer. The levels of pro-inflammatory proteins and AMP-activated protein kinase (AMPK)/Sirtuin 1 (SIRT1) pathway-related proteins were evaluated via Western blot. PBMCs were unaffected by emodin concentrations below 60 μg/mL, and minimal LDH levels were detected in the cells. Emodin attenuated the effects of Escherichia coli and diminished the production of serum complements, oxidative stress-related proteins, and inflammatory factors in PBMCs. Notably, the effects of emodin were lessened by an AMPK pathway inhibitor. Additionally, emodin alleviated oxidative stress, complement system activation, inflammation, and kidney injury in urosepsis rats through the AMPK/SIRT1 signaling pathway. Emodin improved kidney damage in urosepsis rats by activating the AMPK/SIRT1 signaling pathway, which reduced oxidative stress, inflammation, and complement system activation.

SESN2 Ameliorates Dihydrotestosterone-induced Human Ovarian Granulosa Cell Damage by Activating AMPK/ULK1-mediated Mitophagy.

Sestrin 2 (SESN2) has been reported to participate in the regulation of granulosa cell function in ovarian tissues. However, the role of SESN2 in polycystic ovarian syndrome (PCOS) is still incompletely understood. Here, we investigated the functional role and mechanism of SESN2 in dihydrotestosterone (DHT)-induced granulosa cells. In this study, DHT was utilized to induce PCOS cell model and the AMP-activated protein kinase (AMPK) inhibitor Compound C (CC) was utilized to inhibit the AMPK pathway. qRT-PCR was performed to detect the expression of SESN2 in HGLS cells. Cell apoptosis was evaluated by flow cytometry. Oxidative stress was detected by DCFH-DA staining, superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GSH-Px) kits. The expression of SESN2, cell apoptosis, oxidative stress, mitophagy and AMPK/ULK1 signaling-related proteins were measured by western blot. The results showed that SESN2 was downregulated in DHT-induced granulosa cells. Overexpression of SESN2 inhibited the DHT-induced apoptosis and oxidative stress of HGLS cells. DHT induction aggravated HGLS cell apoptosis and oxidative stress. SESN2 overexpression inhibited the DHT-induced apoptosis and oxidative stress of HGLS cells. In addition, overexpression of SESN2 activated the AMPK/ULK1 signaling pathway and promoted mitophagy. Treatment of CC reversed the regulatory effect of SESN2 on mitophagy. CC also reversed the influences of SESN2 overexpression on apoptosis and oxidative stress in DHT-induced HGLS cells. Overall, SESN2 suppressed DHT-induced apoptosis and oxidative stress in PCOS through AMPK/ULK1-mediated mitophagy.

Canola Oil Ameliorates Obesity by Suppressing Lipogenesis and Reprogramming the Gut Microbiota in Mice via the AMPK Pathway.

obesity is a worldwide problem that seriously endangers human health. Canola oil (Col) has been reported to regulate hepatic steatosis by influencing oxidative stress and lipid metabolism in Kunming mice. However, whether Col exhibits an anti-obesity effect by altering the gut microbiota remains unknown. in this study, we observed that a high-fat diet increased lipogenesis and gut microbiota disorder in C57BL/6J male mice, while the administration of Col suppressed lipogenesis and improved gut microbiota disorder. the results show that Col markedly reduced the final body weight and subcutaneous adipose tissue of C57BL/6J male mice fed a high-fat diet (HFD) after 6 weeks of administration. However, although Col did not effectively increase the serum concentration of HDL, we found that treatment with Col notably inhibited the low-density lipoprotein (LDL), total cholesterol (TC), and triglycerides (TGs) in HFD mice. Furthermore, Col ameliorated obesity in the liver compared to mice that were only fed a high-fat diet. We also found that Col significantly inhibited the relative expression of sterol regulatory element binding protein (SREBP1/2), peroxisome proliferator-activated receptor γ (PPARγ), and insulin-induced genes (Insig1/2) that proved to be closely associated with lipogenesis in HFD mice. In addition, the concentration of acetic acid was significantly increased in Col-treatment HFD mice. Further, we noted that Col contributed to the reprogramming of the intestinal microbiota. The relative abundances of Akkermansia, Dubosiella, and Alistipes were enhanced under treatment with Col in HFD mice. The results also imply that Col markedly elevated the phosphorylation level of the AMP-activated protein kinase (AMPK) pathway in HFD mice. the results of our study show that Col ameliorates obesity and suppresses lipogenesis in HFD mice. The underlying mechanisms are possibly associated with the reprogramming of the gut microbiota, in particular, the acetic acid-mediated increased expression of Alistipes via the AMPK signaling pathway.

Protective properties of milk-derived peptide QEPV in attenuating oxidative stress through AMPK/PPARα signaling pathways

Peptides derived from fermented milk have demonstrated diverse bioactivities. In this study, we investigated the protective effects of Gln-Glu-Pro-Val (QEPV) against hydrogen peroxide (H2O2) induced oxidative stress in RAW 264.7 cells and further evaluated its potential in Drosophila melanogaster (D. melanogaster). Pre-incubation with QEPV in vitro dose-dependently promoted cell viability, suppressed oxidative damage, and increased antioxidant enzyme activities in a low-level oxidative stress model. QEPV remarkably extended lifespan under the low-level oxidative stress, validating its practical applicability. These effects were attributed to the upregulation of 5′ adenosine monophosphate-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor alpha (PPARα) signaling pathways, as revealed by label-free proteomic analysis. To confirm the roles of these two signaling pathways, antagonists of AMPK (Dorsomorphin) and PPARα (GW6471) were applied in vitro and in vivo. The protective effects of QEPV were reversed by both antagonists. Overall, QEPV exhibits protective properties by selectively upregulating the AMPK and PPARα signaling pathways, indicating its potential application as an antioxidant food ingredient.

Qiwei Jinggan Ling regulates oxidative stress and lipid metabolism in alcoholic liver disease by activating AMPK

BackgroundAlcoholic liver disease (ALD) is a severe public health concern worldwide and there is still a lack of effective treatments. Qiwei Jinggan Ling (QJL) has protective effects against various liver injuries, but its pharmacological action on ALD has received little attention. PurposeTo investigate the effect and mechanism of QJL on ALD in vivo and in vitro. MethodsIn vivo, an ALD mouse model was established by alcohol combined with a high-fat diet (HFD) and treated with QJL. Biochemical indicators, HE staining, and Oil Red O staining were employed to assess hepatic oxidative stress, steatosis, and alcohol metabolism. RNA sequencing analysis was performed, and the results were verified by qRT-PCR and Western blot to elucidate the hepatoprotective mechanism of QJL. In vitro, HepG2 cells were co-stimulated with NaOA (sodium oleate) and EtOH (ethanol), followed by intervention with Compound C (CC, AMPK inhibitor) and QJL-containing serum. Oil Red O, BODIPY (boron-dipyrromethene), and ROS (reactive oxygen species) staining were applied to validate the efficacy and mechanism of QJL-containing serum. The expression of AMP-activated protein kinase (AMPK) pathway-related factors was analyzed through qRT-PCR and Western blot for additional corroboration. Moreover, the key pharmacodynamic components of QJL were identified by UPLC-MS/MS and molecular docking. ResultsIn vivo, QJL ameliorated liver structural disorders, steatosis, oxidative stress, and impaired alcohol metabolism, as indicated by biochemical indicators and histopathological assays. RNA sequencing analysis revealed that QJL reversed the expression of genes related to alcohol metabolism, fatty acid metabolism, and cholesterol metabolism. The results of qRT-PCR and Western blot were in line with those of RNA sequencing. Furthermore, it was discovered that QJL significantly upregulated the expression of p-AMPK and downregulated the expression of sterol regulatory element binding transcription factor 1 (SREBP-1c). In vitro, biochemical indicators and staining assays demonstrated that QJL-containing serum inhibited lipid accumulation and oxidative stress. The qRT-PCR and Western blot analysis revealed that QJL-containing serum markedly enhanced the expression of p-AMPK and carnitine palmitoyltransferase 1a (Cpt1a), while suppressing the expression of SREBP-1c, fatty acid synthase (Fasn), and acetyl-coenzyme A carboxylase 1 (ACC-1). However, CC inhibited the above pharmacological activities of QJL-containing serum. Additionally, (2S)-Liquiritigenin, Glycyrrhetinate, Isovitexin, Taxifolin, and Yohimbine were proved to be the key active components of QJL. ConclusionQJL had the potential to be a therapeutic drug for ALD by activating the AMPK pathway, thereby regulating lipid metabolism and inhibiting oxidative stress.

SUMOylation-induced membrane localization of TRPV1 suppresses proliferation and migration in gastric cancer cells

Gastric cancer (GC) remains a significant health challenge due to its high mortality rate and the limited efficacy of current targeted therapies. A critical barrier in developing more effective treatments is the lack of understanding of specific mechanisms driving GC progression. This study investigates the role of Transient Receptor Potential Vanilloid 1 (TRPV1), a non-selective cation channel known for its high Ca2+ permeability and tumor-suppressive properties in gastrointestinal cancers. Specifically, we explore the impact of SUMOylation—a dynamic and reversible post-translational modification—on TRPV1’s function in GC. We demonstrate that SUMOylation of TRPV1 inhibits cell proliferation and migration in MGC-803 and AGS GC cells. By mutating amino acids near TRPV1’s existing SUMO motif (slKpE), we created a bidirectional SUMO motif (EψKψE) that enhances TRPV1 SUMOylation, resulting in further suppression of GC cell proliferation and migration. In vivo studies support these findings, showing that TRPV1 SUMOylation prevents spontaneous tumorigenesis in a mouse GC model. Further investigation reveals that TRPV1 SUMOylation increases the protein’s membrane expression by inhibiting its interaction with the adaptor-related protein complex 2 mu 1 subunit (AP2M1). This elevated membrane expression leads to increased intracellular Ca2+ influx, activating the AMP-activated protein kinase (AMPK) pathway, which in turn inhibits the proliferation and migration of GC cells.

Metabolomics Dysfunction in Replicative Senescence of Periodontal Ligament Stem Cells Regulated by AMPK Signaling Pathway.

Periodontal ligament mesenchymal stem cells (PDLSCs) are a promising cell resource for stem cell-based regenerative medicine in dentistry, but they inevitably acquire a senescent phenotype after prolonged in vitro expansion. The key regulators of PDLSCs during replicative senescence remain unclear. Here, we sought to elucidate the role of metabolomic changes in determining the cellular senescence of PDLSCs. PDLSCs were cultured to passages 4, 10, and 20. The senescent phenotypes of PDLSCs were detected, and metabolomics analysis was performed. We found that PDLSCs manifested senescence phenotype during passaging. Metabolomics analysis showed that the metabolism of replicative senescence in PDLSCs varied significantly. The AMP-activated protein kinase (AMPK) signaling pathway was closely related to adenosine monophosphate (AMP) levels. The AMP:ATP ratio increased in senescent PDLSCs; however, the levels of p-AMPK, FOXO1 and FOXO3a decreased with senescence. We treated PDLSCs with an activator of the AMPK pathway (AICAR) and observed that the phosphorylated AMPK level at P20 PDLSCs was partially restored. These data delineate that the metabolic process of PDLSCs is active in the early stage of senescence and attenuated in the later stages of senescence; however, the sensitivity of AMPK phosphorylation sites is impaired, causing senescent PDLSCs to fail to respond to changes in energy metabolism.

A Descriptive Review of the Antioxidant Effects and Mechanisms of Action of Berberine and Silymarin.

Oxidative stress is a key factor in the development of chronic diseases such as type 2 diabetes, cardiovascular diseases, and liver disorders. Antioxidant therapies that target oxidative damage show significant promise in preventing and treating these conditions. Berberine, an alkaloid derived from various plants in the Berberidaceae family, enhances cellular defenses against oxidative stress through several mechanisms. It activates the AMP-activated protein kinase (AMPK) pathway, which reduces mitochondrial reactive oxygen species (ROS) production and improves energy metabolism. Furthermore, it boosts the activity of key antioxidant enzymes like superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), thus protecting cells from oxidative damage. These actions make berberine effective in managing diseases like type 2 diabetes, cardiovascular conditions, and neurodegenerative disorders. Silymarin, a flavonolignan complex derived from Silybum marianum, is particularly effective for liver protection. It activates the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, enhancing antioxidant enzyme expression and stabilizing mitochondrial membranes. Additionally, silymarin reduces the formation of ROS by chelating metal ions, and it also diminishes inflammation. This makes it beneficial for conditions like non-alcoholic fatty liver disease (NAFLD) and alcohol-related liver disorders. This review aims to highlight the distinct mechanisms by which berberine and silymarin exert their antioxidant effects.

AMPK and O-GlcNAcylation: interplay in cardiac pathologies and heart failure.

Heart failure (HF) represents a multifaceted clinical syndrome characterized by the heart's inability to pump blood efficiently to meet the body's metabolic demands. Despite advances in medical management, HF remains a major cause of morbidity and mortality worldwide. In recent years, considerable attention has been directed toward understanding the molecular mechanisms underlying HF pathogenesis, with a particular focus on the role of AMP-activated protein kinase (AMPK) and protein O-GlcNAcylation. This review comprehensively examines the current understanding of AMPK and O-GlcNAcylation signalling pathways in HF, emphasizing their interplay and dysregulation. We delve into the intricate molecular mechanisms by which AMPK and O-GlcNAcylation contribute to cardiac energetics, metabolism, and remodelling, highlighting recent preclinical and clinical studies that have explored novel therapeutic interventions targeting these pathways.

Black raspberry extract stimulates glucose uptake via adenosine monophosphate‐activated protein kinase and phosphatidylinositol‐3 kinase pathways in skeletal muscle cells

AbstractBlack raspberry (Rubus occidentalis) shows beneficial health effects, such as antioxidant, anti‐inflammatory, chemopreventive, antiproliferative, and antihyperglycemic activities. The present study investigated the antihyperglycemic activity of black raspberry extract (BRE) and potential mechanisms in skeletal muscle cells. Differentiated C2C12 myotubes were treated with the BRE (1–1000 μg/mL) or metformin (1 mM). The protein levels of various insulin signaling targets were measured by western blot analysis. BRE significantly increased glucose uptake by upregulated insulin receptor and phosphatidylinositol‐3 kinase (PI3K) in C2C12 cells, leading to enhanced translocation of glucose transporter 4 (GLUT4) to the plasma membrane. The expression of phosphorylated (p)‐adenosine monophosphate‐activated protein kinase (AMPK) was also enhanced by treatment with BRE, this resulting in stimulation of GLUT4 translocation to the plasma membrane and hence glucose uptake in skeletal muscles. These results suggest that BRE has an antihyperglycemic effect by stimulating GLUT4 translocation to the plasma membrane via activating the PI3K and AMPK pathways in skeletal muscle cells, thereby upregulating glucose uptake. Black raspberry is a potential functional food and has important implications for preventing and treating type‐2 diabetes. In addition, our study found that the flavonoids fraction is the main contributor fraction to promote glucose uptake in C2C12 cells.

Lipids and Inflammation: Novel Molecular Targets and Therapeutic Implications.

Atherosclerotic cardiovascular disease represents the most common cause of death worldwide. Altered cholesterol metabolism and inflammation are major cardiovascular risk factors that underpin atherosclerotic plaque growth and destabilization. While initial evidence considered dyslipidemia and inflammation as independent atherogenic actors, growing evidence has revealed that several molecular mechanisms implicated in cholesterol metabolism participate in multiple inflammatory signalling pathways. In particular, proprotein convertase subtilisin/kexin type 9, adenosine monophosphate-activated protein kinase pathway, oxidized low-density lipoproteins, and lipoprotein (a) have been demonstrated to share concurrent atherogenic and inflammatory properties. Novel lipid-lowering therapies targeting these molecular pathways have been implemented. Mechanistic and clinical studies have addressed their hypolipidemic potential and explored their role in atherosclerosis-related vascular inflammation, and ongoing randomized clinical trials are investigating their prognostic role. The purpose of this review was to dive into the signalling pathways linking cholesterol metabolism and inflammation and outline the current evidence on the anti-inflammatory activities of the novel lipid-lowering drugs.

Maternal metformin administration during the pre-gestation period improves transient cerebral ischemia injury in male offspring rats

Purpose: It seems that maternal intervention, which may involve epigenetic mechanisms, can affect cerebral ischemia in offspring. Metformin consumption by the mother activates the AMP-activated protein kinase (AMPK) pathway. Metformin has also induced the AMPK and protected neurons in cerebral ischemia. This study investigates the effect of maternal metformin administration, which activates the AMPK pathway, on cerebral ischemia in offspring Methods: Animals were separated into four groups: sham, 2-vessels occlusion (2VO), Met+2VO, Met+compound c (CC)+2VO. Female rats were administrated with metformin at a dose of 200 mg.kg-1 body weight for 2 weeks prior to mating. After the final metformin injection, each female rat was paired with an intact adult male to allow for mating. Sixty-days old offspring underwent cerebral ischemia and then memory-related tests were done. Results: Current data revealed that the neurological deficits score was reduced Met+2VO group (P<0.001), and the memory increased (P<0.001) in comparison to the 2VO. The Bcl-2/Bax ratio declined in the metformin group (P<0.001) while the Brain-Derived Neurotropic Factor (BDNF), c-fos, p-AMPK/AMPK ratio and Histone H3K9 acetylation in the hippocampus augmented significantly compared to the 2VO group (P<0.001). Conclusion: These findings indicated that the metformin intervention via AMPK activation could improve the movement disability, enhance spatial memory, increase neural plasticity, and augment the bioenergetics state and histone acetylation in the hippocampus of the offspring.

Farrerol Alleviates Diabetic Cardiomyopathy by Regulating AMPK-Mediated Cardiac Lipid Metabolic Pathways in Type 2 Diabetic Rats.

Diabetic cardiomyopathy (DCM) is a prevalent complication of diabetes mellitus characterized by cardiac dysfunction and myocardial remodeling. Farrerol (FA), an active ingredient in Rhododendron with various pharmacological activities, has an unclear specific role in DCM. Therefore, this study aims to investigate the effects of FA on DCM rats and elucidate its mechanism. The type 2 diabetes mellitus (T2DM) model was induced in adult male Sprague-Dawley rats by administering a high-fat diet for 8 weeks along with STZ injection. Subsequent to successful modeling, FA and the positive drug Dapagliflozin (Dapa) were orally administered via gavage for an additional 8-week period. After administration, the rats' body weight, fasting blood glucose, fasting insulin, and blood lipid profiles were quantified. Cardiac function was assessed through evaluation of cardiac function parameters, histopathological examination and measurement of myocardial enzyme markers were conducted to assess myocardial injury and fibrosis, Oil red O staining was utilized to evaluate myocardial lipid accumulation, wheat germ agglutinin (WGA) staining was used for assessing cardiomyocyte hypertrophy, and Western blot analysis was used to detect the proteins expression level of AMP-activated protein kinase (AMPK) pathway. The rat cardiomyocyte H9c2 were induced with palmitic acid to establish an in vitro cell model of myocardial lipid toxicity. Subsequently, the cells were subjected to treatment with FA and AMPK inhibitor Compound C, followed by assessment of lipid formation and expression levels of proteins related to the AMPK signaling pathway. The findings demonstrated that both FA and Dapa exhibited efficacy in ameliorating diabetic symptoms, cardiac dysfunction, myocardial fibrosis, cardiomyocyte hypertrophy, and lipid accumulation in T2DM rats. Additionally, they were found to enhance AMPK phosphorylation and PPARα expression while down-regulating CD36. Similarly, FA was observed to inhibit lipid formation in H9c2 and activate the AMPK signaling pathway. However, the improved effect of FA on lipotoxic cardiomyocytes induced by palmitic acid was partially reversed by Compound C. Therefore, the activation of the AMPK signaling pathway by FA may enhance cardiac lipid metabolism, thereby improving cardiac dysfunction and myocardial fibrosis in DCM rats.

Nrf2 cell signaling pathway is responsible for the antioxidant effect of resveratrol in aging.

One of the markers of aging is oxidative stress, a condition characterized by an increase in free radicals concomitant with a reduction in antioxidant defenses. Within this, resveratrol is a compound that has been shown to act as a potent antioxidant. However, few studies highlight the cellular signaling pathways that are activated or inhibited during aging and that are responsible for this biological effect. To verify the antioxidant profile of resveratrol (5 μM) in leukocytes from donors in different age groups. The project was approved by the Ethics Committee. Individuals were divided into three groups: 20-39, 40-59, and 60-80 years old. After separating the leukocytes, assays were performed to evaluate the AMPK (AMP-activated protein kinase) and Nrf2 (erythroid nuclear factor 2-related factor 2) pathways. In addition, luciferase assay and enzyme-linked immunosorbent assay were performed to evaluate transcription factor activation and Nrf2 expression, respectively. The analysis between age and treatment was performed using Pearson correlation (*P < 0.05). There was a reduction in the antioxidant effect of resveratrol during the aging process. In leukocytes from donors over 60 years of age, the AMPK pathway was silenced. Nrf2 was active at all ages. There was an increase in the activation of the transcription factor and phosphorylated protein in all age groups. Nrf2 is an important biochemical mechanism responsible for the antioxidant effect of resveratrol. This effect diminishes with aging but is still observed. Geriatr Gerontol Int 2024; ••: ••-••.

Metformin enhances endogenous neural stem cells proliferation, neuronal differentiation, and inhibits ferroptosis through activating AMPK pathway after spinal cord injury

BackgroundInadequate nerve regeneration and an inhibitory local microenvironment are major obstacles to the repair of spinal cord injury (SCI). The activation and differentiation fate regulation of endogenous neural stem cells (NSCs) represent one of the most promising repair approaches. Metformin has been extensively studied for its antioxidative, anti-inflammatory, anti-aging, and autophagy-regulating properties in central nervous system diseases. However, the effects of metformin on endogenous NSCs remains to be elucidated.MethodsThe proliferation and differentiation abilities of NSCs were evaluated using CCK-8 assay, EdU/Ki67 staining and immunofluorescence staining. Changes in the expression of key proteins related to ferroptosis in NSCs were detected using Western Blot and immunofluorescence staining. The levels of reactive oxygen species, glutathione and tissue iron were measured using corresponding assay kits. Changes in mitochondrial morphology and membrane potential were observed using transmission electron microscopy and JC-1 fluorescence probe. Locomotor function recovery after SCI in rats was assessed through BBB score, LSS score, CatWalk gait analysis, and electrophysiological testing. The expression of the AMPK pathway was examined using Western Blot.ResultsMetformin promoted the proliferation and neuronal differentiation of NSCs both in vitro and in vivo. Furthermore, a ferroptosis model of NSCs using erastin treatment was established in vitro, and metformin treatment could reverse the changes in the expression of key ferroptosis-related proteins, increase glutathione synthesis, reduce reactive oxygen species production and improve mitochondrial membrane potential and morphology. Moreover, metformin administration improved locomotor function recovery and histological outcomes following SCI in rats. Notably, all the above beneficial effects of metformin were completely abolished upon addition of compound C, a specific inhibitor of AMP-activated protein kinase (AMPK).ConclusionMetformin, driven by canonical AMPK-dependent regulation, promotes proliferation and neuronal differentiation of endogenous NSCs while inhibiting ferroptosis, thereby facilitating recovery of locomotor function following SCI. Our study further elucidates the protective mechanism of metformin in SCI, providing new mechanistic insights for its candidacy as a therapeutic agent for SCI.

Intestinal epithelial differentiation and barrier function is promoted in vitro by a Cynara cardunculus L. leaf extract through AMPK pathway activation

Gut epithelial barrier perturbation leads to leaky gut syndrome and permeation of substances activating immune response. Polyphenols can improve intestinal barrier function and represent candidates for preventing development of leaky gut. Herein, we evaluated in vitro the molecular mechanisms involved in the protective effects of a polyphenol-rich extract from leaves of Cynara cardunculus L. (CCLE) on intestinal barrier function and integrity on Caco-2 human epithelial cells. Treatment with CCLE from seeding until complete differentiation improved intestinal function by increasing trans-epithelial electrical resistance (TEER), reducing paracellular permeability to fluorescein, and promoting faster recovery of tight junctions (TJ) assembly in the Ca2+ switch assay. CCLE stimulated epithelial cell differentiation inducing alkaline phosphatase activity and TJ proteins. These CCLE-induced effects were attributed to activation of AMP-activated protein kinase (AMPK) pathway. Our data support the use of Cynara cardunculus L. leaves, an agricultural co-product rich in bioactive polyphenols, for the health of intestinal epithelium.

Effects of kaempherol-3-rhamnoside on metabolic enzymes and AMPK in the liver tissue of STZ-induced diabetes in mice

Diabetes mellitus (DM) is a chronic metabolic disorder characterized by persistent hyperglycemia. It involves disturbances in carbohydrate, fat, and protein metabolism due to defects in insulin secretion, insulin action, or both. Novel therapeutic approaches are continuously being explored to enhance metabolic control and prevent complications associated with the disease. This study investigates the therapeutic potential of kaempherol-3-rhamnoside, a flavonoid, in managing diabetes by modulating the AMP-activated protein kinase (AMPK) pathway and improving metabolic enzyme activities in streptozotocin (STZ) -induced diabetic mice. Diabetic mice were treated with varying doses of kaempherol-3-rhamnoside and/or insulin over a 28-day period. Glycolytic and gluconeogenesis enzyme activities in the liver, fasting blood glucose levels, serum insulin levels, lipid profiles and oxidative stress markers were assessed. Treatment with kaempherol-3-rhamnoside significantly improved glycolytic enzyme activities, reduced fasting blood glucose, and enhanced insulin levels compared to diabetic controls. The compound also normalized lipid profiles and reduced oxidative stress in the liver, suggesting its potential in reversing diabetic dyslipidemia and oxidative damage. Furthermore, kaempherol-3-rhamnoside activated the AMPK pathway, indicating a mechanism through which it could exert its effects. Kaempherol-3-rhamnoside exhibits promising antidiabetic properties, potentially through AMPK pathway activation and metabolic enzyme modulation. These findings support its potential use as an adjunct therapy for diabetes management. Further clinical studies are warranted to validate these results in human subjects.

Fisetin ameliorates polycystic ovary syndrome in rats via a mechanistic modulation of AMP-activated protein kinase and SIRT1 molecular pathway.

Fisetin, a polyphenolic flavonoid, exhibits numerous pharmacological activities against metabolic syndromes. The present research aims to explore the therapeutic efficacy of fisetin in experimental polycystic ovary syndrome (PCOS). Female Sprague-Dawley rats were administered mifepristone (20mg/kg/day) to induce PCOS. PCOS rats were treated with fisetin (20mg/kg and 40mg/kg) and further compared with metformin HCl, the conventional drug for PCOS. The mechanism of fisetin was explored using dorsomorphin (an AMPK inhibitor). Then, rats were sacrificed for further analysis of biochemical and histological parameters. PCOS rats exhibited irregular estrous cycles, increased serum testosterone (4.72 ± 0.139ng/ml), estradiol (750.2 ± 16.56pg/ml), LH (30.33 ± 1.563 mIU/ml), HOMA-IR (1.115 ± 0.049), TNF-α (86.59 ± 3.93pg/ml), IL-6 (55.34 ± 4.432pg/ml), and TBARS (3.867 ± 0.193µmol/mg) along with declined progesterone (11.67 ± 1.54ng/ml), FSH (13.33 ± 1.256 mIU/ml), GSH (33.47 ± 1.348µmol/mg) levels, and SOD (2.163 ± 0.298 U/mg) activity as compared to normal control group. Fisetin high dose significantly lowers testosterone (3.014 ± 0.234ng/ml), estradiol (533.7 ± 15.39pg/ml), LH (16.67 ± 1.62 mIU/ml), HOMA-IR (0.339 ± 0.20), TNF-α (46.02 ± 2.66pg/ml), IL-6 (31.77 ± 3.47pg/ml), and TBARS (1.747 ± 0.185µmol/mg) and enhances progesterone (33.17 ± 1.447ng/ml), FSH (27.17 ± 1.42 mIU/ml), GSH (60.35 ± 1.1.102µmol/mg) levels, and SOD (4.513 ± 0.607 U/mg) activity. The histology of ovarian tissues shows a significant increase in cystic follicles in PCOS rats compared with the normal control group. These alterations were attenuated with fisetin treatment. Administration of dorsomorphin with fisetin can reverse the beneficial effects of fisetin in PCOS rats. Altogether, these present findings highlight the potential of fisetin as a promising therapeutic intervention for the management of PCOS by modulating AMPK/SIRT1 signaling in rats.

N-acetyltransferase 10 facilitates tumorigenesis of diffuse large B-cell lymphoma by regulating AMPK/mTOR signalling through N4-acetylcytidine modification of SLC30A9.

Accumulating studies suggested that posttranscriptional modifications exert a vital role in the tumorigenesis of diffuse large B-cell lymphoma (DLBCL). N4-acetylcytidine (ac4C) modification, catalyzed by the N-acetyltransferase 10 (NAT10), was a novel type of chemical modification that improves translation efficiency and mRNA stability. GEO databases and clinical samples were used to explore the expression and clinical value of NAT10 in DLBCL. CRISPER/Cas9-mediated knockout of NAT10 was performed to determine the biological functions of NAT10 in DLBCL. RNA sequencing, acetylated RNA immunoprecipitation sequencing (acRIP-seq), LC-MS/MS, RNA immunoprecipitation (RIP)-qPCR and RNA stability assays were performed to explore the mechanism by which NAT10 contributed to DLBCL progression. Here, we demonstrated that NAT10-mediated ac4C modification regulated the occurrence and progression of DLBCL. Dysregulated N-acetyltransferases expression was found in DLBCL samples. High expression of NAT10 was associated with poor prognosis of DLBCL patients. Deletion of NAT10 expression inhibited cell proliferation and induced G0/G1 phase arrest. Furthermore, knockout of NAT10 increased the sensitivity of DLBCL cells to ibrutinib. AcRIP-seq identified solute carrier family 30 member 9 (SLC30A9) as a downstream target of NAT10 in DLBCL. NAT10 regulated the mRNA stability of SLC30A9 in an ac4C-dependent manner. Genetic silencing of SLC30A9 suppressed DLBCL cell growth via regulating the activation of AMP-activated protein kinase (AMPK) pathway. Collectively, these findings highlighted the essential role of ac4C RNA modification mediated by NAT10 in DLBCL, and provided insights into novel epigenetic-based therapeutic strategies.

Kaempferia parviflora extract and its component polymethoxyflavones suppress adipogenic differentiation of human bone marrow-derived mesenchymal stem cells via the AMPK pathway.

Kaempferia parviflora Wall. ex. Baker (KP) has been reported to exhibit anti-obesity effects. However, the detailed mechanism of the anti-obesity effect of KP extract (KPE) is yet to be clarified. Here, we investigated the effect of KPE and its component polymethoxyflavones (PMFs) on the adipogenic differentiation of human mesenchymal stem cells (MSCs). KPE and PMFs fraction (2.5µg/mL) significantly inhibited lipid and triacylglyceride accumulation in MSCs; lipid accumulation in MSCs was suppressed during the early stages of differentiation (days 0-3) but not during the mid (days 3-7) or late (days 7-14) stages. Treatment with KPE and PMFs fractions significantly suppressed peroxisome proliferator-activated receptor-γ (PPARγ), CCAAT/enhancer binding protein α (C/EBPα), and various adipogenic metabolic factors. Treatment with KPE and PMFs fraction induced the activation of AMP-activated protein kinase (AMPK) signaling, and pretreatment with an AMPK signaling inhibitor significantly attenuated KPE- and PMFs fraction-induced suppression of lipid formation. Our findings demonstrate that KPE and PMFs fraction inhibit lipid formation by inhibiting the differentiation of undifferentiated MSCs into adipocyte lineages via AMPK signaling, and this may be the mechanism underlying the anti-obesity effects of KPE and PMFs. Our study lays the foundation for the elucidation of the anti-obesity mechanism of KPE and PMFs.