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Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Geniposidic 4-isoamyl ester (GENI) with anti-aging effects is a new iridoid glycoside derivative from Gardenia jasminoides Ellis found in our previous study. In this study, to indicate whether this compound has anti-Alzheimer's disease (AD) effect, the galactose-induced AD mice and naturally aging mice with AD were used to do drug efficacy evaluation. Furthermore, the Western blot, small interfering RNA (siRNA), drug affinity responsive target stability (DARTS), cellular thermal shift assay (CESTA), liquid chromatography-tandem mass spectrometry (LC/MS-MS), adenosine 5′-monophosphate-activated protein kinase (AMPK) mutants and surface plasmon resonance (SPR) analysis were utilized to clarify the mechanism of action and identify target protein of this molecule. GENI exerts anti-AD efficacy in galactose-induced AD mice and naturally aging mice with AD through neuroprotection and modification of autophagy and neuron inflammation. Moreover, AMPK as the target protein of GENI to produce an anti-AD effect is identified and the ASP148, ASP157, and ASP166 of the AMPK α subunit and lysine (LYS)148, aspartic acid (ASP)156, LYS309, and ASP316 in the AMPK γ subunit as binding sites are confirmed. Meanwhile, the AMPK/unc-51-like autophagy-activating kinase 1 (ULK1)/microtubule-associated protein 1 light chain 3 beta (LC3B) and AMPK/mammalian target of rapamycin (mTOR) signaling pathways involved in anti-AD effects of GENI. The findings provide a new perspective on treating neurodegenerative diseases by activating AMPK for the energy metabolism disorder. [ABSTRACT FROM AUTHOR]

Postmortem energy metabolism is a key biochemical pathway that affects meat tenderness, and glycolysis is the dominant process of postmortem energy metabolism, which is regulated by numerous factors. This article reviews the factors that affect the postmortem glycolysis process and the underlying mechanisms. AMP-activated protein kinase (AMPK) and sirtuin 1 (SIRT1) are important upstream regulatory factors for postmortem glycolysis. This article focuses on summarizing the effect of the AMPK/SIRT1 signaling pathway on glycolysis and postmortem endogenous enzyme systems and clarifying the underlying mechanism, in order to provide new ideas for regulating meat tenderness through the AMPK/SIRT1 signaling pathway.

BACKGROUND: The energy metabolism and polarization state of macrophages play a crucial role in the progression of atherosclerosis. Traditional Chinese Medicine (TCM) has shown significant therapeutic potential for prevention and treatment of atherosclerosis by regulating macrophage metabolic pathways. OBJECTIVE: To review the research progress in AMP-activated protein kinase regulation of macrophage energy metabolism and polarization and explore the mechanism of TCM in the prevention and treatment of atherosclerosis. METHODS: A computerized search was conducted on the databases including Web of Science, PubMed, and CNKI, covering relevant literature up to June 2024. The search terms were “AMPK, fatty acid oxidation, macrophage polarization, Traditional Chinese Medicine, atherosclerosis, coronary heart disease” in Chinese and English. A total of 62 articles were finally included for review. RESULTS AND CONCLUSION: The shift in macrophage energy metabolism from oxidative phosphorylation to glycolysis plays a key role in the progression of atherosclerosis. The activation of AMP-activated protein kinase in macrophages promotes fatty acid oxidation and M2 polarization, exerting anti-inflammatory effects and stabilizing arterial plaques. TCM monomers (such as ginseng, astragalus, and polygonatum) and compounds (such as Huanglian Jiedu Decoction, Yangxin Shumai Granules, and Tiaogan Daozhuo Formula) influence macrophage metabolism and cellular function by regulating the AMP-activated protein kinase pathway and intervening in multiple signaling pathways, such as nuclear factor-κB, peroxisome proliferator-activated receptor γ, and mammalian target of rapamycin, thereby achieving therapeutic effects. Future research should focus on the interactions between AMP-activated protein kinase, metabolism, and polarization pathways, as well as how TCM exerts its therapeutic effects through these pathways, providing new strategies for the treatment of atherosclerosis. [ABSTRACT FROM AUTHOR]

Parkinson’s disease (PD) is a gradually worsening neurodegenerative condition marked by the deterioration of dopaminergic neurons, motor dysfunction, and mitochondrial dysfunction. Trans-chalcone, a natural flavonoid, has shown promise in various disease models because of its antioxidant and anti-inflammatory features. This study investigates the neuroprotective effects of transchalcone in a rat model of PD, focusing on its impact on the activation levels of AMP-activated protein kinase (AMPK) signaling pathway, sirtuin1 (SIRT1) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) proteins, and mitochondrial-inflammatory responses. Male Sprague Dawley rats were allocated into five groups Control, Control plus transchalcone, PD, PD plus transchalcone, PD plus compound-C, and PD plus Compound-C and trans-chalcone. PD was induced using intranigral 6-hydroxydopamine injection. Trans-chalcone (100 μg/kg) and compound-C (20 mg/kg) were intraperitoneally administered daily for 4 weeks in PD rats. Motor function was assessed using rota-rod and grid tests. Striatal dopamine and cytokines (interleukin 1-beta [IL-1 β], IL-10) and p65-nuclear factor kappa-B (NF-κB) levels were measured with enzyme-linked immunosorbent assay. Mitochondrial function was evaluated by fluorometric techniques. The expression of phosphorylated AMPK, PGC-1α, and SIRT1 was analyzed by Western blotting. Trans-chalcone treatment significantly improved motor function, evidenced by increased latency to fall in the rota-rod test and recovered traversal time in the grid test. It also restored dopamine levels, enhanced mitochondrial function (reduced reactive oxygen species levels, increased membrane potential, and adenosine triphosphate production), normalized cytokines (IL-1 β, IL-10) and p65-NF-κB, and upregulated the proteins expression in rats with PD. Inhibition of AMPK activity with compound-C suppressed the neuroprotective impacts of trans-chalcone, highlighting the contribution of AMPK signaling pathway in its mechanism of action. Neuroprotective and mitoprotective impacts of trans-chalcone were mostly mediated through the activation of AMPK-SIRT1-PGC1α pathway. These results indicate that trans-chalcone could be a promising therapeutic agent for PD, warranting further investigation to assess its efficacy and safety in human patients.

Abstract Atrial fibrillation (AF) is the most prevalent arrhythmia in clinical practice, and obesity serves as a significant risk factor for its development. The underlying mechanisms of obesity-related AF remain intricate and have yet to be fully elucidated. We have identified FPR2 as a potential hub gene involved in obesity-related AF through comprehensive analysis of four transcriptome datasets from AF patients and one transcriptome dataset from obese individuals, and its expression is up-regulated in both AF and obese individuals. Interestingly, ANXA1, the endogenous ligand of FPR2, was found to exhibit differential expression with AF and obesity. Specifically, it was observed to be down-regulated in AF patients but up-regulated in obese individuals. The susceptibility to AF in obese mice induced by high-fat diet (HFD) was increased following with the FPR2 blocker Boc-2.The administration of exogenous ANXA1 active peptide chain Ac2-26 can mitigate the susceptibility to AF in obese mice by attenuating atrial fibrosis, lipid deposition, oxidative stress injury, and myocardial cell apoptosis. However, this protective effect against AF susceptibility is reversed by AAV9-shAMPK-mediated AMPK specific knockdown in the myocardium. The vitro experiments demonstrated that silencing ANXA1 exacerbated lipid deposition, oxidative stress injury, and apoptosis induced by palmitic acid (PA) in cardiomyocytes. Additionally, Ac2-26 effectively mitigated myocardial lipid deposition, oxidative stress injury, and apoptosis induced by PA. These effects were impeded by FPR2 inhibitors Boc-2 and WRW4. The main mechanism involves the activation of AMPK by ANXA1 through FPR2 in order to enhance fatty acid oxidation in cardiomyocytes, thereby ultimately leading to a reduction in lipid accumulation and associated lipotoxicity. Our findings demonstrate that the ANXA1-FPR2 axis plays a protective role in obesity-associated AF by alleviating metabolic stress in the atria of obese mice, thereby emphasizing its potential as a promising therapeutic target for AF.

Aims Methods Results Conclusions Acute hypoglycaemia promotes pro‐inflammatory cytokine production, increasing the risk for cardiovascular events in diabetes. AMP‐activated protein kinase (AMPK) is regulated by and influences the production of pro‐inflammatory cytokines. We sought to examine the mechanistic role of AMPK in low glucose‐induced changes in the pro‐inflammatory cytokine macrophage migration inhibitory factor (MIF), which is elevated in people with diabetes.Macrophage cell line Raw264.7 cells, primary macrophage bone marrow‐derived macrophages obtained from wild‐type mice or AMPK γ1 gain‐of‐function mice, were used, as were AMPKα1/α2 knockout mouse embryonic fibroblasts (MEFs). Allosteric AMPK activators PF‐06409577 and BI‐9774 were used in conjunction with inhibitor SBI‐0206965. We examined changes in protein phosphorylation/expression using western blotting and protein localisation using immunofluorescence. Metabolic function was assessed using extracellular flux analyses and luciferase‐based ATP assay. Cytokine release was quantified by enzyme‐linked immunosorbent assay (ELISA). Oxidative stress was detected using a fluorescence‐based reactive oxygen species (ROS) assay, and cell viability was examined using flow cytometry.Macrophages exposed to low glucose showed a transient and modest activation of AMPK and a metabolic shift towards increased oxidative phosphorylation. Moreover, low glucose increased oxidative stress and augmented the release of macrophage MIF. However, pharmacological activation of AMPK by PF‐06409577 and BI‐9774 attenuated low glucose‐induced MIF release, with a similar trend noted with genetic activation using AMPKγ1 gain‐of‐function (D316A) mice, which produced a mild effect on low glucose‐induced MIF release. Inhibition of NFĸB signalling diminished MIF release and AMPK activation modestly but significantly reduced low glucose‐induced nuclear translocation of NFĸB.Taken together, these data indicate that pharmacological AMPK activation suppresses the release of MIF from macrophages caused by energy stress, suggesting that AMPK activation could be a useful strategy for mitigating hypoglycaemia‐induced inflammation. [ABSTRACT FROM AUTHOR]

Atrial fibrillation (AF) is the most prevalent arrhythmia in clinical practice, and obesity serves as a significant risk factor for its development. The underlying mechanisms of obesity-related AF remain intricate and have yet to be fully elucidated. We have identified FPR2 as a potential hub gene involved in obesity-related AF through comprehensive analysis of four transcriptome datasets from AF patients and one transcriptome dataset from obese individuals, and its expression is up-regulated in both AF and obese individuals. Interestingly, ANXA1, the endogenous ligand of FPR2, was found to exhibit differential expression with AF and obesity. Specifically, it was observed to be down-regulated in AF patients but up-regulated in obese individuals. The susceptibility to AF in obese mice induced by high-fat diet (HFD) was increased following with the FPR2 blocker Boc-2.The administration of exogenous ANXA1 active peptide chain Ac2-26 can mitigate the susceptibility to AF in obese mice by attenuating atrial fibrosis, lipid deposition, oxidative stress injury, and myocardial cell apoptosis. However, this protective effect against AF susceptibility is reversed by AAV9-shAMPK-mediated AMPK specific knockdown in the myocardium. The vitro experiments demonstrated that silencing ANXA1 exacerbated lipid deposition, oxidative stress injury, and apoptosis induced by palmitic acid (PA) in cardiomyocytes. Additionally, Ac2-26 effectively mitigated myocardial lipid deposition, oxidative stress injury, and apoptosis induced by PA. These effects were impeded by FPR2 inhibitors Boc-2 and WRW4. The main mechanism involves the activation of AMPK by ANXA1 through FPR2 in order to enhance fatty acid oxidation in cardiomyocytes, thereby ultimately leading to a reduction in lipid accumulation and associated lipotoxicity. Our findings demonstrate that the ANXA1-FPR2 axis plays a protective role in obesity-associated AF by alleviating metabolic stress in the atria of obese mice, thereby emphasizing its potential as a promising therapeutic target for AF. [ABSTRACT FROM AUTHOR]

Lipid droplets (LDs) serve as crucial hubs for lipid trafficking and metabolic regulation through their numerous interactions with various organelles. While the interplay between LDs and the Golgi apparatus has been recognized, their roles and underlying mechanisms remain poorly understood. Here, we reveal the role of Ras-related protein Rab-2A (Rab2A) in mediating LD-Golgi interactions, thereby contributing to very-low-density lipoprotein (VLDL) lipidation and secretion in hepatocytes. Mechanistically, our findings identify a selective interaction between Golgi-localized Rab2A and 17-beta-hydroxysteroid dehydrogenase 13 (HSD17B13) protein residing on LDs. This complex facilitates dynamic organelle communication between the Golgi apparatus and LDs, thus contributing to lipid transfer from LDs to the Golgi apparatus for VLDL2 lipidation and secretion. Attenuation of Rab2A activity via AMP-activated protein kinase (AMPK) suppresses the Rab2A-HSD17B13 complex formation, impairing LD-Golgi interactions and subsequent VLDL secretion. Furthermore, genetic inhibition of Rab2A and HSD17B13 in the liver reduces the serum triglyceride and cholesterol levels. Collectively, this study provides a new perspective on the interactions between the Golgi apparatus and LDs. Synopsis: The interplay between lipid droplets (LDs) and the Golgi apparatus has been well established, yet their mechanistic details and functional significance remain largely elusive. This study identifies Golgi-associated Rab2A GTPase and 17-beta-hydroxysteroid dehydrogenase 13 (HSD17B13) as key mediators of LD-Golgi interactions, orchestrating the lipidation and secretion of very-low-density lipoprotein (VLDL) in hepatocytes. Hepatic Rab2A deletion impairs VLDL lipidation and secretion, resulting in decreased serum triglyceride and cholesterol levels. HSD17B13 on LDs binds to Golgi-residing Rab2A, thus enhancing Golgi-LD contact formation and lipid transfer to the Golgi. Rab2A interaction with HSD17B13 promotes VLDL lipidation and secretion. AMP-activated protein kinase (AMPK) signaling attenuates Rab2A activity, inhibiting Golgi-LD communications and VLDL secretion. Rab2A binds a hydroxysteroid dehydrogenase, enhancing lipid transport from lipid droplets into the Golgi apparatus. [ABSTRACT FROM AUTHOR]

Rehmannia glutinosa Libosch., which belongs to the Orobanchaceae family, is a perennial herb found in China, Japan, and Korea. In traditional medicine, it is used to cool the body, improve water metabolism in the kidney, and provide protection from metabolic diseases such as type 2 diabetes mellitus (T2DM) and obesity. In this study, three new compounds were isolated from the roots of R. glutinosa, along with eighteen known compounds. Structure elucidation was performed with spectroscopic analyses including nuclear magnetic resonance (NMR) and circular dichroism (CD) spectroscopy. As the AMP-activated protein kinase (AMPK) signaling pathway is reportedly related to metabolic diseases, AMPK activation studies were conducted using in silico simulations and in vitro assays. Among the isolated compounds, 1 showed a potential as an AMPK activator in both in silico simulations and in vitro experiments. Our findings expand the chemical profiles of the plant R. glutinosa and suggest that one newly found compound (1) activates AMPK. [ABSTRACT FROM AUTHOR]

Dendropanax morbifera Leveille is a traditional medicine used to treat migraine headache and dysmenorrhea. In this study, three polyacetylenes, methyl (10E,9R,16R)-16-acetoxy-9-hydroxyoctadeca-10,17-dien-12,14-diynoate (1), methyl (10E,9R,16S)-9,16-dihydroxyoctadeca-10-en-12,14-diynoate (2), and methyl (10Z,9R,16S)-9,16-dihydroxyoctadeca-10,17-dien-12,14-diynoate (3), were isolated from the aerial parts of D. morbifera, together with seven known compounds (4–10). Importantly, the isolates (6 and 8) were found in the family Araliaceae for the first time in this study. Compounds 1−10 were evaluated for their binding affinity to AMPK and CTSS receptors using in silico docking simulations. Only compound 7 increased the protein expression levels of PPAR-α, Sirt1, and AMPK when administered to HepG2 cells as a PPAR-α agonist. On the other hand, 7 did not produce any significant reduction in CTSS activity. This study could pave the way for the discovery of novel treatments from D. morbifera targeting PPAR-α and AMPK. [ABSTRACT FROM AUTHOR]

Background and Purpose: Diabetic patients have an increased risk of psychiatric disorders. Because hyperglycaemia increases L‐lactate in the brain and L‐lactate inhibits AMP‐activated protein kinase (AMPK), this study investigated the role of L‐lactate and AMPK in strengthened fear memory, a model for human psychiatric disorders, in diabetic mice. Experimental Approach: The diabetic model was mice injected with streptozotocin. Fear memory was measured using the conditioned fear test with low (0.45 mA) or high (0.50 mA) foot shock to cause low and high freezing, respectively. Protein levels of AMPK and phosphorylated AMPK (pAMPK) were measured by western blotting and immunohistochemistry. Key Results: At 0.45 mA, the AMPK inhibitor dorsomorphin increased freezing, which was inhibited by the AMPK activator acadesine. In contrast, at 0.50 mA, acadesine decreased freezing, which was inhibited by dorsomorphin. In diabetic mice, pAMPK was decreased in the amygdala and hippocampus. Diabetic mice showed increased freezing at 0.45 mA, which was inhibited by acadesine. In the amygdala and hippocampus, L‐lactate was increased in diabetic mice and injection of L‐lactate into non‐diabetic mice increased freezing at 0.45 mA. In addition, L‐lactate decreased pAMPK in the hippocampus, but not the amygdala, and increase in freezing induced by L‐lactate was inhibited by acadesine. Dorsomorphin‐induced increase in freezing was inhibited by the AMPA receptor antagonist NBQX. Conclusions and Interpretation: In diabetic mice, L‐lactate is increased in the amygdala and hippocampus, possibly through hyperglycaemia, which strengthens fear memory through inhibition of AMPK and activation of glutamatergic function. [ABSTRACT FROM AUTHOR]

AMP-activated protein kinase (AMPK) is an energy sensor that regulates cellular functions in response to changes in energy availability. However, whether AMPK activity is spatially regulated, and the implications for cell function, have been unclear. We now report that AMPK associates with the Golgi, and that its activation by two specific pharmacological activators leads to Golgi fragmentation similar to that caused by the antibiotic Golgicide A, an inhibitor of Golgispecific Brefeldin A resistance factor-1 (GBF1), a guanine nucleotide exchange factor that targets ADP-ribosylation factor 1 (ARF1). Golgi fragmentation in response to AMPK activators is lost in cells carrying gene knockouts of AMPK-α subunits. AMPK has been previously reported to phosphorylate GBF1 at residue Thr1337, and its activation causes phosphorylation at that residue. Importantly,Golgi disassembly upon AMPK activation is blocked in cells expressing a nonphosphorylatable GBF1-T1337A mutant generated by gene editing. Furthermore, the trafficking of a plasma membrane-targeted protein through the Golgi complex is delayed by AMPK activation. Our findings provide a mechanism to link AMPK activation during cellular energy stress to downregulation of protein trafficking involving the Golgi. [ABSTRACT FROM AUTHOR]

In the present study, we succeeded in extracting tea polysaccharide (TPS) from Tieguanyin oolong tea, and the TPS was characterized. TPS is an acidic heteropolysaccharide containing rhamnose, arabinose, galactose, glucose (Glc), xylose, mannose, galacturonic acid, and guluronic acid. We found that TPS supplementation partially reversed the elevated levels of serum alanine aminotransferase, total cholesterol, and low‐density lipoprotein cholesterol in high‐fat diet (HD)‐induced nonalcoholic fatty liver disease (NAFLD) mice (p < 0.05), and hepatic steatosis and impaired Glc tolerance were also ameliorated. After HD intervention, the activity of Adenosine 5'‐monophosphate‐activated protein kinase (AMPK) and its downstream genes, including Sirtuin 1 (SIRT1), sterol regulatory element‐binding protein‐1c (SREBP1c), acetyl‐coenzyme A carboxylase 1 (ACC1), and adipose triglyceride lipase (ATGL), was significantly inhibited (p < 0.05). TPS can increase the expression of these genes. The hepatoprotective effects of TPS in AMPK−/− mice almost completely disappeared. Moreover, the expression levels of SIRT1, SREBP1c, ACC1, and ATGL did not significantly change after TPS supplementation (p > 0.05). Therefore, our findings suggest that TPS protects the liver from hepatic glucolipid metabolism disorders in HD‐induced NAFLD mice by activating AMPK‐mediated signaling pathways. [ABSTRACT FROM AUTHOR]

AMP-activated protein kinase (AMPK) dysregulation is implicated in osteoarthritis (OA), but the mechanisms underlying this dysregulation remain unclear. We investigated the role of cereblon, a substrate-recognition protein within the E3-ligase ubiquitin complex, in AMPK dysregulation and OA pathogenesis. Cereblon expression was examined in human (n = 5) and mouse (n = 10) OA cartilage. The role of cereblon was investigated through its adenoviral overexpression (n = 10) or knockout (KO, n = 15) in the destabilization of the medial meniscus (DMM)-operated mice. The therapeutic potentials of the chemical cereblon degrader, TD-165, and the AMPK activator, metformin, were assessed through intra-articular (IA) injection to mice (n = 15). Immunostaining revealed that cereblon is upregulated in human and mouse OA cartilage. In DMM model mice, cartilage destruction was exacerbated by overexpression of cereblon in mouse joint tissues (OARSI grade; 1.11 [95% CI: 0.50 to 2.75]), but inhibited in global (−2.50 [95% CI: −3.00 to −1.17]) and chondrocyte-specific (−2.17 [95% CI: −3.14 to −1.06]) cereblon KO mice. The inhibitory effects were more pronounced in mice fed a high-fat diet compared to a regular diet. The degradation of cereblon through IA injection of TD-165 inhibited OA cartilage destruction (−2.47 [95% CI: −3.22 to −1.56]). Mechanistically, cereblon exerts its catabolic effects by negatively modulating AMPK activity within chondrocytes. Consistently, activation of AMPK by IA injection of metformin inhibited posttraumatic OA cartilage destruction (−1.20 ([95% CI: −1.89 to −0.45]). The cereblon-AMPK axis acts as a catabolic regulator of OA pathogenesis and seems to be a promising therapeutic target in animal models of OA. [ABSTRACT FROM AUTHOR]

Glioblastoma, the most frequent primary malignant brain tumour in adults, is characterised by profound yet dynamic hypoxia and nutrient depletion. To sustain survival and proliferation, tumour cells are compelled to acquire metabolic plasticity with the induction of adaptive metabolic programs. Here, we interrogated the pathways necessary to enable processing of nutrients other than glucose. We employed genetic approaches (stable/inducible overexpression, CRISPR/Cas9 knockout), pharmacological interventions with a novel inhibitor of AMP‐activated protein kinase (AMPK) in glioblastoma cell culture systems and a proteomic approach to investigate mechanisms of metabolic plasticity. Moreover, a spatially resolved multiomic analysis was employed to correlate the gene expression pattern of PGC‐1α with the local metabolic and genetic architecture in human glioblastoma tissue sections. A switch from glucose to alternative nutrients triggered an activation of AMPK, which in turn activated PGC‐1α‐dependent adaptive programs promoting mitochondrial metabolism. This sensor‐effector mechanism was essential for metabolic plasticity with both functional AMPK and PGC‐1α necessary for survival and growth of cells under nonglucose nutrient sources. In human glioblastoma tissue specimens, PGC‐1α‐expression correlated with nonhypoxic tumour niches defining a specific metabolic compartment. Our findings reveal a cell‐intrinsic nutrient sensing and switching mechanism. The exposure to alternative fuels triggers a starvation signal that subsequently is passed on via AMPK and PGC‐1α to induce adaptive programs necessary for broader spectrum nutrient metabolism. The integration of spatially resolved transcriptomic data confirms the relevance of PGC‐1α especially in nonhypoxic tumour regions. Thus, the AMPK‐PGC‐1α axis is a candidate for therapeutic inhibition in glioblastoma. Key Points/Highlights: AMPK activation induces PGC‐1α expression in glioblastoma during nutrient scarcity.PGC‐1α enables metabolic plasticity by facilitating metabolism of alternative nutrients in glioblastoma.PGC‐1α expression is inversely correlated with hypoxic tumour regions in human glioblastomas. [ABSTRACT FROM AUTHOR]

AMP-activated protein kinase is a crucial regulator of cellular metabolism with potential therapeutic implications in various diseases. In this study, the benzimidazole scaffold was chosen for investigation with EX-229 as the lead compound. Modifications were made to the terminal carboxyl group, and the methylindole moiety was replaced with phenylpyrrolidinone to synthesize and assess the AMP-activated protein kinase-activating properties of 13 benzimidazole derivatives. In vitro studies have shown that most of the synthesized compounds have significant excitatory effects on AMP-activated protein kinase. Particularly, A11 demonstrated the most potent activity with an EC50 value of 39 nM. Combining activity data and molecular docking analysis revealed the necessity of end-molecule hydrogen bond donors for LYS29, and the importance of an appropriate torsion angle at the pyrrolidinone position to facilitate the formation of a crucial hydrogen bond with LYS31. These discoveries offer preliminary insights into the interaction of small-molecule drugs with the AMP-activated protein kinase protein and establish a foundation for the future development of AMP-activated protein kinase activators guided by structure–activity relationships. [ABSTRACT FROM AUTHOR]

Autophagy is a lysosome‐mediated self‐degradation process of central importance for cellular quality control. It also provides macromolecule building blocks and substrates for energy metabolism during nutrient or energy deficiency, which are the main stimuli for autophagy induction. However, like most biological processes, autophagy itself requires ATP, and there is an energy threshold for its initiation and execution. We here present the first comprehensive review of this often‐overlooked aspect of autophagy research. The studies in which ATP deficiency suppressed autophagy in vitro and in vivo were classified according to the energy pathway involved (oxidative phosphorylation or glycolysis). A mechanistic insight was provided by pinpointing the critical ATP‐consuming autophagic events, including transcription/translation/interaction of autophagy‐related molecules, autophagosome formation/elongation, autophagosome fusion with the lysosome, and lysosome acidification. The significance of energy‐dependent fine‐tuning of autophagic response for preserving the cell homeostasis, and potential implications for the therapy of cancer, autoimmunity, metabolic disorders, and neurodegeneration are discussed. [ABSTRACT FROM AUTHOR]

Aims/hypothesis: Appropriate management of blood glucose levels and the prevention of complications are important in the treatment of diabetes. We have previously reported on a compound named HPH-15 that is not only antifibrotic but also AMP-activated protein kinase (AMPK)-activating. In this study, we evaluated whether HPH-15 is useful as a therapeutic medication for diabetes. Methods: We examined the effects of HPH-15 on AMPK activation, glucose uptake, fat accumulation and lactic acid production in L6-GLUT4, HepG2 and 3T3-L1 cells, as a model of muscle, liver and fat tissue, respectively. Additionally, we investigated the glucose-lowering, fat-accumulation-suppressing, antifibrotic and AMPK-activating effect of HPH-15 in mice fed a high-fat diet (HFD). Results: HPH-15 at a concentration of 10 µmol/l increased AMPK activation, glucose uptake and membrane translocation of GLUT4 in each cell model to the same extent as metformin at 2 mmol/l. The production of lactic acid (which causes lactic acidosis) in HPH-15-treated cells was equal to or less than that observed in metformin-treated cells. In HFD-fed mice, HPH-15 lowered blood glucose from 11.1±0.3 mmol/l to 8.2±0.4 mmol/l (10 mg/kg) and 7.9±0.4 mmol/l (100 mg/kg) and improved insulin resistance. The HPH-15 (10 mg/kg) group showed the same level of AMPK activation as the metformin (300 mg/kg) group in all organs. The HPH-15-treated HFD-fed mice also showed suppression of fat accumulation and fibrosis in the liver and fat tissue; these effects were more significant than those obtained with metformin. Mice treated with high doses of HPH-15 also exhibited a 44% reduction in subcutaneous fat. Conclusions/interpretation: HPH-15 activated AMPK at lower concentrations than metformin in vitro and in vivo and improved blood glucose levels and insulin resistance in vivo. In addition, HPH-15 was more effective than metformin at ameliorating fatty liver and adipocyte hypertrophy in HFD-fed mice. HPH-15 could be effective in preventing fatty liver, a common complication in diabetic individuals. Additionally, in contrast to metformin, high doses of HPH-15 reduced subcutaneous fat in HFD-fed mice. Presumably, HPH-15 has a stronger inhibitory effect on fat accumulation and fibrosis than metformin, accounting for the reduction of subcutaneous fat. Therefore, HPH-15 is potentially a glucose-lowering medication that can lower blood glucose, inhibit fat accumulation and ameliorate liver fibrosis. [ABSTRACT FROM AUTHOR]

BACKGROUND Hypertension may result in atrial fibrillation (AF) and lipid metabolism disorders. The Sirtuins3 (SIRT3)/AMP-activated protein kinase (AMPK) signaling pathway has the capacity to regulate lipid metabolism disorders and the onset of AF. We hypothesize that the SIRT3/AMPK signaling pathway suppresses lipid metabolism disorders, thereby mitigating salt-sensitive hypertension (SSHT)-induced susceptibility to AF. METHODS The study involved 7-week-old male Dahl salt-sensitive that were fed either a high-salt diet (8% NaCl; DSH group) or a normal diet (0.3% NaCl; DSN group). Then DSH group was administered either oral metformin (MET, an AMPK agonist) or intraperitoneal injection of Honokiol (HK, a SIRT3 agonist). This experimental model allowed for the measurement of Systolic blood pressure (SBP), the expression levels of lipid metabolism-related biomarkers, pathological examination of atrial fibrosis, and lipid accumulation, as well as AF inducibility and AF duration. RESULTS DSH decrease SIRT3, phosphorylation-AMPK, and very long-chain acyl-CoA dehydrogenase, (VLCAD) expression, increased FASN and FABP4 expression and concentrations of free fatty acid and triglyceride, atrial fibrosis and lipid accumulation in atrial tissue, enhanced level of SBP, promoted AF induction rate and prolonged AF duration, which are blocked by MET and HK. Our results also showed that the degree of atrial fibrosis was negatively correlated with VLCAD expression, but positively correlated with the expression of FASN and FABP4. CONCLUSIONS We have confirmed that a high-salt diet can result in hypertension, and associated atrial tissue lipid metabolism dysfunction. This condition is linked to the inhibition of the SIRT3/AMPK signaling pathway, which plays a significant role in the progression of susceptibility to AF in SSHT rats. [ABSTRACT FROM AUTHOR]

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The neurotoxicant trimethyltin (TMT) triggers cognitive impairment and hippocampal neurodegeneration. TMT is a useful research tool for the study of Alzheimer's disease (AD) pathogenesis and treatment. Although the antidiabetic agent metformin has shown promising neuroprotective effects, however, its precise modes of action in neurodegenerative disorders need to be further elucidated. In this study, we investigated whether metformin can mitigate TMT cognition impairment and hippocampal neurodegeneration. To induce an AD-like phenotype, TMT was injected i.p. (8 mg/kg) and metformin was administered daily p.o. for 3 weeks at 200 mg/kg. Our results showed that metformin administration to the TMT group mitigated learning and memory impairment in Barnes maze, novel object recognition (NOR) task, and Y maze, attenuated hippocampal oxidative, inflammatory, and cell death/pyroptotic factors, and also reversed neurodegeneration-related proteins such as presenilin 1 and p-Tau. Hippocampal level of AMP-activated protein kinase (AMPK) as a key regulator of energy homeostasis was also improved following metformin treatment. Additionally, metformin reduced hippocampal acetylcholinesterase (AChE) activity, glial fibrillary acidic protein (GFAP)-positive reactivity, and prevented the loss of CA1 pyramidal neurons. This study showed that metformin mitigated TMT-induced neurodegeneration and this may pave the way to develop new therapeutics to combat against cognitive deficits under neurotoxic conditions. [ABSTRACT FROM AUTHOR]

Objective:To explore the possible role of ginkgolide K (GK) in the treatment of traumatic brain injury (TBI) and analyze its effect on AMP-activated protein kinase (AMPK) activity.Methods:Rats were divided into Sham group,TBI group,L-GK group,M-GK group,H-GK group,and H-GK+CC group (n=11) .Rats in Sham group was sham-operated rats,and rats in other groups were TBI model rats which made by craniocerebral injury instrument.Rats in Sham group and TBI group were administered 0.5%CMC-Na by intragastric administration.Rats in L-GK group,M-GK group,and H-GK group were administered 2,4,and 8 mg/kg/d ginkgolide K respectively.Rats in H-GK+CC group were given with 8 mg/kg/d Ginkgolide K and intraperitoneally injected with 20 mg/kg/d of AMPK inhibitor Compound C (CC) .Rats were all dosed for 14 days.Neurological function was assessed by the modified Neurological Severity Score (mNSS) .The Morris water maze test was used to evaluate cognitive function,and the escape latency (EL) and the number of platform crossings within 1 min (NPC) were recorded.Brain tissue sections were subjected to HE,Nissl and TUNEL staining as well as Bax and Bcl-2 immunohistochemical staining.The levels of SOD,CAT,GSH-Px,MDA,IL-1β,IL-6 and TNF-α,the activities of Na+-K+-ATPase and Ca2+-Mg2+-ATPase and the content of ATP in brain tissue were detected according to the kit instructions.The serum levels of NO and T-NOS were detected by colorimetry.The protein expression levels of p-AMPKα (Thr172),p62 and Beclin-1 in brain tissue were detected by Western blot.Results:Compared with Sham group,the mNSS score and EL of TBI group increased (P＜0.05),the NPC decreased (P＜0.05),the HE staining score increased (P＜0.05),the TUNEL positivity rate and Bax staining score increased (P＜0.05),the Bcl-2 staining score decreased (P＜0.05),the levels of MDA,IL-1β,IL-6,TNF-α,NO and T-NOS increased (P＜0.05),the levels of SOD,CAT and GSH-Px decreased (P＜0.05),the activities of Na+-K+-ATPase and Ca2+-Mg2+-ATPase and ATP content decreased (P＜0.05),the relative expression levels of p-AMPKα (Thr172) and Beclin-1 protein decreased (P＜0.05),and the relative expression levels of p62 protein increased (P＜0.05) .Compared with TBI group,the mNSS score and EL of L-GK,M-GK and H-GK groups decreased (P＜0.05),the NPC increased (P＜0.05),the HE staining score decreased (P＜0.05),the TUNEL positive rate and Bax staining score decreased (P＜0.05),the Bcl-2 staining score increased (P＜0.05), the levels of MDA,IL-1β,IL-6,TNF-α,NO and T-NOS decreased (P＜0.05),the levels of SOD,CAT and GSH-Px increase (P＜0.05),the activities of Na+-K+-ATPase and Ca2+-Mg2+-ATPase and ATP content increased (P＜0.05),the relative expression level of p-AMPKα (Thr172) and Beclin-1 protein increased (P＜0.05),and the relative expression level of p62 protein decreased (P＜0.05) .Compared with H-GK group,the mNSS score and EL of H-GK+CC group increased (P＜0.05),the NPC decreased (P＜0.05),the HE staining score increased (P＜0.05),the TUNEL positivity rate and Bax staining score increased (P＜0.05),the Bcl-2 staining score decreased (P＜0.05),the levels of SOD,CAT and GSH-Px decreased (P＜0.05),the levels of MDA,IL-1β,IL-6,TNF-α,NO and T-NOS increased (P＜0.05),the activities of Na+-K+-ATPase and Ca2+-Mg2+-ATPase and ATP content decreased (P＜0.05), the relative expression levels of p-AMPKα (Thr172) and Beclin-1 protein decreased (P＜0.05),and the relative expression levels of p62 protein increased (P＜0.05) .Conclusion:Ginkgolide K could alleviate brain damage in TBI rats by improving AMPK-mediated energy metabolism and autophagy. MoreReset [ABSTRACT FROM AUTHOR]

Introduction: Diabetes mellitus is known to provoke devastating anomalies in myocardial structure and function, while effective therapeutic regimen is still lacking. The selective protease inhibitor UCF101 (5-[5-(2-nitrophenyl) furfuryl iodine]-1,3-diphenyl-2-thiobarbituric acid) has been shown to fend off ischemic heart injury, although its impact on diabetic cardiomyopathy remains elusive. Methods: Our present work was conducted to examine the effect of UCF101 on experimental diabetes-evoked cardiac geometric and functional abnormalities as well as mechanisms involved. Adult mice were made diabetic using streptozotocin (STZ, 50 mg/kg, i.p., for 5 days) while receiving UCF101 (7.15 mg/kg, i.p.). Results: STZ evoked cardiac hypertrophy, interstitial fibrosis, mitochondrial ultrastructural damage, oxidative stress, dampened autophagy (LC3B, Beclin 1, elevated p62), mitophagy (FUNDC1 and Parkin with upregulated TOM20), increased left ventricular end systolic diameter, reduced fractional shortening, ejection fraction, cardiomyocyte shortening capacity, velocities of shortening/re-lengthening, and rise in intracellular Ca2+ in conjunction with elongated diastole and intracellular Ca2+ removal, the responses were overtly reconciled by UCF101 with little effects from UCF101 itself. Levels of cell injury markers Omi/HtrA2, TNFα, and stress signaling (JNK, ERK, p38) were overtly enhanced along with compromised phosphorylation of cellular fuel AMP-activated protein kinase (AMPK) (Thr172) and cell survival molecule GSK3β, as well as downregulated SERCA2a and elevated phospholamban, the effect was reversed by UCF101 (except for SERCA2a). AMPK knockout, pharmacological inhibition, the mitophagy inhibitor liensinine, and parkin knockout nullified UCF101-offered cardioprotection in diabetes. UCF101 reversed STZ-induced upregulation in the AMPK degrading enzymes PP2A and PP2C. Conclusion: These findings suggest that UCF101 rescues diabetes-mediated alterations in cardiac structure and function, likely through AMPK-mediated regulation of mitophagy. [ABSTRACT FROM AUTHOR]

Background: Small‐cell lung cancer (SCLC) shows high enhancer of zeste homolog 2 (EZH2) expressions. EZH2‐mediated epigenetics promote epithelial‐mesenchymal transition (EMT), enhancing invasive and metastatic potential in malignancies. MicroRNAs (miRNAs), small noncoding RNAs, modulate EMT, determining tumor phenotypes. However, the association between miRNAs and EZH2 in SCLC remains to be clarified—we aimed to identify a novel tumorigenic mechanism through miRNAs, EZH2, and EMT in SCLC, leading to future therapeutic applications. Methods: We analyzed EZH2 and E‐cadherin expressions in lung cancer cell lines and tumor tissues from 34 SCLC patients and confirmed EZH2 siRNA‐mediated EMT inhibition. miRNA expression profiles were compared between EZH2 knockdown SCLC cells and negative control SCLC cells using miRNA array. We identified a target miRNA of EZH2 showing expressional differences in EZH2‐knockdown cells and analyzed the impact of the miRNA on EZH2‐mediated EMT and tumorigenesis. Results: All SCLC cells showed increased EZH2 and decreased E‐cadherin expressions. SCLC tissues had higher EZH2 and lower E‐cadherin expressions than other lung cancer tissues. miRNA array revealed that miR‐4448 expression increased in EZH2‐knockdown SCLC cells. miR‐4448 overexpression reduced tumor cell growth and prevented EMT. miR‐4448 bound to the 3′UTR of the girdin gene and suppressed its expression, thereby decreasing Akt phosphorylation at Ser473. Attenuated Akt phosphorylation resulted in AMP‐activated protein kinase (AMPK) phosphorylation at Thr172 and 183, enhancing EZH2 phosphorylation at Thr311. Conclusion: SCLC characterized high EZH2 expression and promoted EMT, compared with non‐small cell lung cancer. miR‐4448 inhibited Girdin expression, reducing Akt phosphorylation, and enhancing AMPK and EZH2 phosphorylation. Eventually, miR‐4448 prevented EZH2‐mediated EMT and tumorigenesis by modulating the Girdin/Akt/AMPK axis in SCLC. miR‐4448 might be a potential SCLC inhibitor. [ABSTRACT FROM AUTHOR]

Pomegranate polyphenol ellagic acid has medicinal potential in neurodegenerative disorders. The advantageous effect of this polyphenol in improving cognition in okadaic acid (OA)-instigated murine model with unraveling some modes of its action was assessed. Rats received ICV okadaic acid (OA) and post-treated with oral ellagic acid for 3 weeks (25 and 100 mg/kg/day). Cognition was analyzed in behavioral tasks besides assessment of oxidative, apoptotic, and inflammatory factors in addition to hippocampal histochemical analysis. Ellagic acid at a dose of 100 mg/kg properly attenuated cognitive abnormalities in novel object recognition (NOR), Y maze, and Barnes maze tests. Additionally, ellagic acid diminished hippocampal changes of malondialdehyde (MDA), protein carbonyl, reactive oxygen species (ROS), glutathione (GSH), glutathione peroxidase, superoxide dismutase (SOD), apoptotic factors caspases 1 and 3, tumor necrosis factor α (TNFα), and acetylcholinesterase (AChE) and beta secretase 1 (BACE 1) besides reversal of AMP-activated protein kinase (AMPK) and hyperphosphorylated tau (p-tau). Moreover, lower glial fibrillary acidic protein (GFAP) and less injury of hippocampal CA1 pyramidal neurons were observed upon ellagic acid. To conclude, neuroprotective potential of ellagic acid was shown which is somewhat attributable to its reversal of oxidative, apoptotic, and neuroinflammatory events in addition to proper regulation of AMPK and p-tau. [ABSTRACT FROM AUTHOR]

The effects of trehalose, an autophagy-inducing disaccharide with neuroprotective properties, on the neurotoxicity of parkinsonian mimetics 6-hydroxydopamine (6-OHDA) and 1-methyl-4-phenylpiridinium (MPP+) are poorly understood. In our study, trehalose suppressed 6-OHDA-induced caspase-3/PARP1 cleavage (detected by immunoblotting), apoptotic DNA fragmentation/phosphatidylserine externalization, oxidative stress, mitochondrial depolarization (flow cytometry), and mitochondrial damage (electron microscopy) in SH-SY5Y neuroblastoma cells. The protection was not mediated by autophagy, autophagic receptor p62, or antioxidant enzymes superoxide dismutase and catalase. Trehalose suppressed 6-OHDA-induced activation of c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), and AMP-activated protein kinase (AMPK), as revealed by immunoblotting. Pharmacological/genetic inhibition of JNK, p38 MAPK, or AMPK mimicked the trehalose-mediated cytoprotection. Trehalose did not affect the extracellular signal-regulated kinase (ERK) and mechanistic target of rapamycin complex 1 (mTORC1)/4EBP1 pathways, while it reduced the prosurvival mTORC2/AKT signaling. Finally, trehalose enhanced oxidative stress, mitochondrial damage, and apoptosis without decreasing JNK, p38 MAPK, AMPK, or AKT activation in SH-SY5Y cells exposed to MPP+. In conclusion, trehalose protects SH-SY5Y cells from 6-OHDA-induced oxidative stress, mitochondrial damage, and apoptosis through autophagy/p62-independent inhibition of JNK, p38 MAPK, and AMPK. The opposite effects of trehalose on the neurotoxicity of 6-OHDA and MPP+ suggest caution in its potential development as a neuroprotective agent. [ABSTRACT FROM AUTHOR]

Aim: Bile acids (BA) function as signalling molecules regulating glucose‐lipid homeostasis and energy expenditure. However, the expression of the apical sodium‐dependent bile acid transporter (ASBT) in the kidney, responsible for renal BA reabsorption, is downregulated in patients with diabetic kidney disease (DKD). Using the db/db mouse model of DKD, this study aimed to investigate the effects of rescuing ASBT expression via adeno‐associated virus‐mediated delivery of ASBT (AAVASBT) on kidney protection. Methods: Six‐week‐old male db/db mice received an intraparenchymal injection of AAVASBT at a dose of 1 × 1011 viral genomes (vg)/animal and were subsequently fed a chow diet for 2 weeks. Male db/m mice served as controls. For drug treatment, daily intraperitoneal (i.p.) injections of the farnesoid X receptor (FXR) antagonist guggulsterone (GS, 10 mg/kg) were administered one day after initiating the experiment. Results: AAVASBT treatment rescued renal ASBT expression and reduced the urinary BA output in db/db mice. AAVASBT treatment activated kidney mitochondrial biogenesis and ameliorated renal impairment associated with diabetes by activating FXR. In addition, the injection of FXR antagonist GS in DKD mice would reverse these beneficial effects by AAVASBT treatment. Conclusion: Our work indicated that restoring renal ASBT expression slowed the course of DKD via activating FXR. FXR activation stimulates mitochondrial biogenesis while reducing renal oxidative stress and lipid build up, indicating FXR activation's crucial role in preventing DKD. These findings further suggest that the maintenance of renal BA reabsorption could be a viable treatment for DKD. Summary at a glance: Restoring renal apical sodium‐dependent bile acid transporter (ASBT) expression attenuates diabetic kidney disease (DKD) progression through farnesoid X receptor activation, which promotes mitochondrial biogenesis and reduces oxidative stress and lipid accumulation.Modulating renal bile acid reabsorption via ASBT upregulation holds promise as a therapeutic approach for DKD management. [ABSTRACT FROM AUTHOR]

Objectives: Galectin‐9 (Gal‐9) is an immune checkpoint ligand for T‐cell immunoglobulin and mucin domain 3. Although the roles of Gal‐9 in regulating immune responses have been well investigated, their biological roles have yet to be fully documented. This study aimed to analyse the expression of Gal‐9 bone marrow (BM) cells in C57BL/6J (B6) mice. Furthermore, the co‐expression of Gal‐9 with the mammalian target of rapamycin (mTOR) and AMP‐activated protein kinase (AMPK) was investigated. Methods: The BM cells in adult C57BL/6J (B6) mice were collected and analysed in vitro. Results: In a flow cytometric analysis of BM cells, Gal‐9 was highly expressed in c‐KithiSca‐1−CD34−CD71+ erythroid progenitors (EPs), whereas it was downregulated in more differentiated c‐KitloCD71+TER119+ cells. Subsequently, a negative selection of CD3−B220−Sca‐1−CD34−CD41−CD16/32− EPs was performed. This resulted in substantial enrichment of KithiCD71+Gal‐9+ cells and erythroid colony‐forming units (CFU‐Es), suggesting that the colony‐forming subset of EPs are included in the KithiCD71+Gal‐9+ population. Furthermore, we found that EPs had lower mTOR and AMPK expression levels in Gal‐9 knockout B6 mice than in wild‐type B6 mice. Conclusions: These results may stimulate further investigation of the role of Gal‐9 in haematopoiesis. [ABSTRACT FROM AUTHOR]

Ulcerative colitis (UC) is a subtype of inflammatory bowel disease affecting the colon with idiopathic origin. Melinjo endosperm extract (MeE) contains polyphenolic compounds that have antioxidative and anticancer properties. We examined the effect of MeE on inflammation and mucin expression in the colons of UC of mice treated with dextran sulfate sodium (DSS). C57BL/6J male mice were assigned into four categories: control, DSS + 0% MeE, DSS + 0.1% MeE, and DSS + 0.5% MeE. The control group was provided distilled water and a standard chow diet for 4 weeks. In DSS + 0% MeE, DSS + 0.1% MeE, and DSS + 0.5% MeE groups, the mice were treated with MeE for 3 weeks followed by MeE diets and drinking water containing 3% DSS for a week. Macrophage count, the mucus area stained by Alcian blue (AB), the levels of adenosine monophosphate-activated protein kinase (AMPK), nuclear factor-κB (NFκB) p65, and silent information regulator (Sirt) 1 protein expression, as well as proinflammatory mediators and Mucin 2 mRNA expression were assessed. In the DSS + 0% MeE group, the AB-stained areas and Mucin 2 mRNA expression levels were observed to be lower than those of controls. However, the levels in the +0.5% MeE group were significantly increased. Compared with the control group, the macrophage number, the expression of IL-1β mRNA, and NFκB p65 protein in the DSS + 0% MeE group showed a significant increase. Conversely, these levels were significantly decreased in the +0.5% MeE group. The phosphorylated AMPK and Sirt1 protein levels were upregulated in the +0.5% MeE group. In conclusion, MeE may alleviate UC injury by reducing macrophage infiltration and regulating the AMPK/NFκB/Sirt1 pathway. [ABSTRACT FROM AUTHOR]

IntroductionPolycystic ovary syndrome (PCOS) is a complex disorder characterized by metabolic and ovulatory dysfunctions, often associated with an imbalance in gut microbiota. Despite current treatments, effective management strategies targeting underlying mechanisms remain limited.MethodsIn this study, we used a rat model of PCOS induced by letrozole and a high-fat diet. The effect of intestinal AMP-activated protein kinase (AMPK) activation was evaluated through metformin administration, the most commonly used AMPK activator. We analyzed metabolic parameters, ovulatory functions, gut microbiota composition, and serum levels of Indole-3-carboxaldehyde (I3A), a metabolite involved in inflammation and apoptosis regulation.ResultsMetformin treatment significantly reversed metabolic disorders and restored ovulatory functions in PCOS rats. Moreover, metformin treatment led to notable improvements in gut microbiota composition and an increase in serum I3A levels, which have been shown to mitigate inflammation and apoptosis.DiscussionThis study highlights the therapeutic potential of targeting intestinal AMPK in managing PCOS. By improving both metabolic and reproductive health, activation of AMPK may offer a promising approach for restoring physiological balance in PCOS patients.

Abstract Background The fruit of Phyllanthus emblica L., a traditional medicine in China and India, is used to treat diabetes mellitus. Its water extract (WEPE) has demonstrated hypoglycemic effects in diabetic rats, but its mechanisms on glucose utilization and insulin resistance in skeletal muscle remain unclear. Therefore, this study aims to investigate the effects and underlying mechanisms of WEPE on glucose utilization and insulin resistance using C2C12 myotubes. Methods Effects of WEPE on glucose uptake, GLUT4 translocation, and AMPK and AKT phosphorylation were investigated in C2C12 myotubes and palmitate-treated myotubes. An AMPK inhibitor and siRNA were used to explore the mechanisms of WEPE. Glucose uptake was determined using a 2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino)-2-deoxyglucose (2-NBDG) uptake assay, and protein expression and GLUT4 translocation were assessed via western blotting. Results In normal myotubes, WEPE significantly stimulated glucose uptake and GLUT4 translocation to the plasma membrane at concentrations of 125 and 250 µg/mL. This was accompanied by an increase in the phosphorylation of AMPK and its downstream targets. However, both compound C and AMPK siRNA blocked the WEPE-induced GLUT4 translocation and glucose uptake. Moreover, pretreatment with STO-609, a calcium/calmodulin-dependent protein kinase kinase β (CaMKKβ) inhibitor, inhibited WEPE-induced AMPK phosphorylation and attenuated the WEPE-stimulated glucose uptake and GLUT4 translocation. In myotubes treated with palmitate, WEPE prevented palmitate-induced insulin resistance by enhancing insulin-mediated glucose uptake and AKT phosphorylation. It also restored the insulin-mediated translocation of GLUT4 from cytoplasm to membrane. However, these effects of WEPE on glucose uptake and GLUT4 translocation were blocked by pretreatment with compound C. Conclusions WEPE significantly stimulated basal glucose uptake though CaMKKβ/AMPK pathway and markedly ameliorated palmitate-induced insulin resistance by activating the AMPK pathway in C2C12 myotubes.

8-Prenylgenistein (8PG), a genistein derivative, is present in fermented soybeans (Glycine max), including cheonggukjang (CGJ), and exhibits osteoprotective, osteogenic, and antiadipogenic properties. However, the hepatoprotective effects of 8PG and its underlying molecular mechanisms remain largely unexplored. Here, we identified the high binding affinity of 8PG with AMP-activated protein kinase (AMPK) and sirtuin 1 (SIRT1), which acts as a potent AMPK activator that counteracts hepatic steatosis. Notably, 8PG exhibited better pharmacokinetics with greater absorption and higher plasma binding than the positive controls for the target proteins. Moreover, 8PG exerted non-carcinogenic activity in rats and significantly increased AMPK phosphorylation. Compound C, an AMPK inhibitor, did not antagonize 8PG-activated AMPK in HepG2 cells. 8PG significantly attenuated palmitate-induced lipid accumulation and enhanced phosphorylated AMPK and its downstream target, acetyl-CoA carboxylase. Further, 8PG activated nuclear SIRT1 at the protein level, which promoted fatty acid oxidation in palmitate-treated HepG2 cells. Overall, 8PG acts as a potent AMPK activator, further attenuating hepatic steatosis via the SIRT1-mediated pathway and providing new avenues for dietary interventions to treat metabolic dysfunction-associated steatotic liver disease (MASLD). [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Hypertension is a globally prevalent disease, but the pathogenesis remains largely unclear. AMP-activated protein kinase (AMPK) is a nutrition-sensitive signal of cellular energy metabolism, which has a certain influence on the development of hypertension. Previously, we found a down-regulation of the phosphorylated (p-) form of AMPK, and the up-regulation of the angiotensin II type 1 receptor (AT1-R) and that of p-ERK1/2 in the hypothalamic paraventricular nucleus (PVN) of hypertensive rats. However, the exact mechanism underlying the relationship between AMPK and AT1-R in the PVN during hypertension remains unclear. Thus, we hypothesized that AMPK modulates AT1-R through the ERK1/2-NF-κB pathway in the PVN, thereby inhibiting sympathetic nerve activity and improving hypertension. To examine this hypothesis, we employed a renovascular hypertensive animal model developed via two-kidney, one-clip (2K1C) and sham-operated (SHAM). Artificial cerebrospinal fluid (aCSF), used as vehicle, or 5-amino-1-β-d-ribofuranosyl-imidazole-4-carboxamide (AICAR, an AMPK activator, 60 μg/day) was microinjected bilaterally in the PVN of these rats for 4 weeks. In 2K1C rats, there an increase in systolic blood pressure (SBP) and circulating norepinephrine (NE). Also, the hypertensive rats had lowered expression of p-AMPK and p-AMPK/AMPK, elevated expression of p-ERK1/2, p-ERK1/2/ERK1/2 and AT1-R, increased NF-κB p65 activity in the PVN compared with the levels of these biomarkers in SHAM rats. Four weeks of bilateral PVN injection of AMPK activator AICAR, attenuated the NE level and SBP, increased the expression of p-AMPK and p-AMPK/AMPK, lessened the NF-κB p65 activity, decreased the expression of p-ERK1/2, p-ERK1/2/ERK1/2 and AT1-R in the PVN of 2K1C rats. Data from this study imply that the activation of AMPK within the PVN suppressed AT1-R expression through inhibiting the ERK1/2-NF-κB pathway, decreased the activity of the sympathetic nervous system, improved hypertension. [ABSTRACT FROM AUTHOR]

Metabolic dysfunction‐associated steatotic liver disease (MASLD) is strongly associated with insulin resistance development. Hepatic lipid accumulation and inflammation are considered the main drivers of hepatic insulin resistance in MASLD. Cysteine‐rich 61 (Cyr61 also called CCN1), a novel secretory matricellular protein, is implicated in liver inflammation, and its role in MASLD is not clearly understood. Therefore, we investigated the role of Cyr61 in hepatic insulin resistance and lipid metabolism as major factors in MASLD pathogenesis. In high‐fat diet (HFD)‐fed C57BL/6J mice, Cyr61 was downregulated or upregulated via viral transduction. Measurements of glucose homeostasis, histological assessment of liver tissues, and gene expression and signaling pathways of lipogenesis, fatty acid oxidation, and inflammation were performed using liver samples from these mice. Cyr61 levels in HepG2 cells were reduced using RNAi‐mediated gene knockdown. Inflammation and insulin resistance were evaluated using real‐time polymerase chain reaction and western blotting. HFD/AAV‐shCyr61 mice exhibited enhanced glucose tolerance via the protein kinase B pathway, reduced hepatic inflammation, decreased lipogenesis, and increased fatty acid oxidation. Notably, HFD/AAV‐shCyr61 mice showed elevated protein expression of sirtuin 6 and phosphorylated‐AMP‐activated protein kinase. In vitro experiments demonstrated that inhibition of Cyr61 downregulated pro‐inflammatory cytokines such as interleukin‐1 beta, IL‐6, and tumor necrosis factor‐alpha via the nuclear factor kappa B/c‐Jun N‐terminal kinase pathway, and alleviated insulin resistance. Cyr61 affected hepatic inflammation, lipid metabolism, and insulin resistance. Inhibition of Cyr61 reduced inflammation, recovered insulin resistance, and altered lipid metabolism in vivo and in vitro. Therefore, Cyr61 is a potential therapeutic target in MASLD. [ABSTRACT FROM AUTHOR]

Objective To observe the effect of total flavonoids of Dracocephalum Moldavica L. on bleomycin-induced pulmonary fibrosis （PF) in rats and to explore the possible mechanism based on intestinal flora and serum metabolomics approaches. Methods Thirty-two male SD rats were randomly divided into the control group， model group， high dose total flavonoids of Dracocephalum Moldavica L. group and low-dose total flavonoids of Dracocephalum Moldavica L. group， with 8 rats in each group. In addition to the control group， the model was established by intratracheal drip of bleo‑ mycin in each group；400 mg/kg and 100 mg/kg of total flavonoids of Dracocephalum Moldavica L. were given by gavage in the high- and low-dose groups， respectively， and an equal volume of normal saline was given by gavage in the control group and the model group， respectively， once a day for 21 d. The lung histopathology was observed by HE and Masson staining. The collagen Ⅲ（COLⅢ) and α-smooth muscle actin （α-SMA) mRNA expression levels in the lung tissues were detected by real-time fluorescence quantitative PCR. 16S rRNA sequencing technology was used to detect the diversity and relative abundance of intestinal flora， and ultra-high-performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS) was used to analyse and screen for the key differential metabolites in serum， which were then imported into the Kyoto Encyclopedia of Genes and Genomes （KEGG) for the metabolic pathway enrichment analysis. Results Com‑ pared with the control group， the alveolar structure of rats in the model group was destroyed， the alveolar intervals were widened， the inflammatory cell infiltration was obvious， the alveolar wall was thickened， the distance between the alveoli was widened， and the deposition of collagen fibres in blue stripes was seen； compared with the model group， the above pathological changes were reduced in rats in the high- and low-dose total flavonoids of Dracocephalum Moldavica L. groups. Compared with the control group， the relative expression levels of COLⅢ and α-SMA mRNA in the lung tissues of rats in the model group increased （all P<0. 05)； compared with the model group， the relative expression levels of COLⅢ and α-SMA mRNA in the lung tissues of rats in the high- and low-dose total flavonoids of Dracocephalum Moldavica L. groups decreased （all P<0. 05). Analysis of α-diversity showed that， compared with the control group， the model group， the intestinal flora Chao1 and Ace increased in the high-dose and low-dose total flavonoids of Dracocephalum Moldavica L. groups （all P<0. 05). The β-diversity analysis showed that the composition of the intestinal flora of the rats in the control group， the high-dose and low-dose total flavonoids of Dracocephalum Moldavica L. groups were close to each other， and that was different from the composition of the intestinal flora of the rats in the model group. At the phylum level， compared with the control group， the relative abundance of Bacteroidota decreased， while the abundances of Firmicutes/Bacteroidota increased in rats of the model group （all P<0. 05)； compared with the model group， the relative abundance of Bacteroidota in rats in the high- and low-dose total flavonoids of Dracocephalum Moldavica L. groups increased， while the relative abun‑ dances of Firmicutes/Bacteroidota decreased （all P<0. 05). At the genus level， compared with the control group， the rela‑ tive abundances of Ligilactobacillus decreased in the remaining three groups （all P<0. 05)； compared with the control and model groups， the relative abundances of Lactobacillus increased in the high- and low-dose total flavonoids of Dracoceph‑ alum Moldavica L. groups （all P<0. 05). Compared with the control group， the key differential flora of rats in the model group was Escherichia coli species； compared with the model group， the key differential floras of rats in the high-dose total flavonoids of Dracocephalum Moldavica L. group were Bifidobacterium pseudo-longum， Bifidobacterium bifidum， and Ru‑ minococcus； compared with the model group， the key differential floras of rats in the low-dose total flavonoids of Draco‑ cephalum Moldavica L. group were Lactobacillus johannesiensis and Akkermansia muciniphila. Thirty and forty-nine se‑ rum differential metabolites were screened out between the model group and the high- and low-dose total flavonoids of Dracocephalum Moldavica L. groups， all of which were mainly enriched in the AMP-activated protein kinase （AMPK) sig‑ naling pathway， etc. Conclusion Total flavonoids of Dracocephalum Moldavica L. attenuate bleomycin-induced PF in rats， and the mechanism of action may be related to regulating the composition of intestinal flora and AMPK-related meta‑ bolic pathways， etc. [ABSTRACT FROM AUTHOR]

Obesity is one of the more complicated diseases, it can induce numerous life‐threatening diseases mainly diabetes mellitus, cardiovascular disease, hypertension, and certain cancers. In this study, we assessed the efficacy of bacoside‐A (a dammarane‐type triterpenoid saponin derived from the plant Bacopa monniera Linn.) on the adipogenesis of 3T3‐L1 preadipocytes. Results of this study illustrated that bacoside‐A decreased the differentiation of 3T3‐L1 cell, as evidenced by diminution of lipid droplets, which contains triglycerides and other lipids. During the differentiation process, transcription factors, which are mainly participating in adipogenesis such us CCAAT/enhancer‐binding protein α (C/EBPα) and C/EBPβ, peroxisome proliferator‐activated receptor‐γ (PPARγ), and sterol regulatory element‐binding protein‐1c (SREBP‐1c), expressions were significantly suppressed by bacoside‐A. In addition, bacoside‐A showed a potent reduction in genes precise to adipocytes such as lipoprotein lipase (LPL), fatty acid synthase (FAS), adipocyte fatty acid‐binding protein (FABP4), and leptin expressions. Further, bacoside‐A stimulated the phosphorylation of acetyl CoA carboxylase (ACC) and AMP‐activated protein kinase (AMPK). These results demonstrated that bacoside‐A has anti‐adipogenic effects by regulating the transcription factors involved in adipocyte differentiation. Therefore, bacoside‐A might be considered as a potent therapeutic agent for alleviating obesity and hyperlipidemia. [ABSTRACT FROM AUTHOR]