AMPK Signaling Pathway Research Articles

Exploring the Molecular Mechanisms underlying SADI-S Improves Glucose Metabolism in Type 2 Diabetic Rats through Liver Transcriptomics and Proteomics Analysis.

Metabolic surgery could improve or even reverse type 2 diabetes mellitus (T2DM). Single-anastomosis duodenal-ileal bypass with sleeve gastrectomy (SADI-S) is one of the most effective metabolic surgeries for T2DM. However, the molecular mechanisms behind the SADI-S-induced T2DM improvement are not fully understood.Here,T2DM rats received SADI-S and were sacrificed after 8 weeks; the controls received sham surgery; Liver tissues were collected for transcriptomics and proteomics analysis to identify differentially expressed genes (DEGs) and proteins (DEPs). Parallel reaction monitoring (PRM) was performed to validate the accuracy of the proteomics results.SADI-S significantly improved glucose metabolism in T2DM rats.A total of 120 genes/proteins(e.g., phosphoenolpyruvate carboxykinase (Pck1) and pyruvate kinase (Pklr)) exhibited consistent expression trends at both mRNA and protein levels. Among the upregulated genes/proteins involved in glucose metabolic pathways, enrichment was observed in pathways such as the pyruvate metabolic pathway, insulin signaling pathway, glycolysis/gluconeogenesis biological processes, glucagon signaling pathway, and AMPK signaling pathway. Downregulated genes/proteins were enriched in the pyruvate metabolic pathway. The above-mentioned signaling pathways are implicated in glucose metabolism, suggesting a potential mechanism for SADI-S-mediated alleviation of T2DM. The PRM validation results indicated that all selected proteins showed consistent trends between PRM and proteomics data. This consistency suggests the reliability of the proteomics results.

The anthraquinone derivative KA-4s reduces energy metabolism and enhances the sensitivity of ovarian cancer cells to cisplatin.

Ovarian cancer is the leading cause of death from female gynecological cancers. Cisplatin (DDP)is a first-line drug for ovarian cancer treatment. Due to DDP resistance, there is an urgent need for novel therapeutic drugs with improved antitumor activity. AMPK-mediated metabolic regulatory pathways are related to tumor drug resistance. Our study aimed to determine the relationship between reversing DDP resistance with the anthraquinone derivative KA-4s and regulating AMPK energy metabolism in ovarian cancer. The results showed that KA-4s inhibited the proliferation of ovarian cancer cells. The combination of KA-4s with DDP effectively promoted drug-resistant ovarian cancer cell apoptosis and inhibited cell migration and invasion. Moreover, KA-4s decreased the intracellular ATP level and increased the calcium ion level, leading to AMPK phosphorylation. Further studies suggested that the AMPK signaling pathway may be involved in the mechanism through which KA-4s reduce drug resistance. KA-4s inhibited mitochondrial respiration and glycolysis; downregulated the glucose metabolism-related proteins GLUT1 and GLUT4; the lipid metabolism-related proteins SREBP1 and SCD1; and the drug resistance-related proteins P-gp, MRP1, and LRP. The inhibitory effect of KA-4s on GLUT1 was confirmed by the application of the GLUT1 inhibitor BAY-876. KA-4s combined with DDP significantly increased the expression of p-AMPKand reduced the expression of P-gp. In a xenograft model of ovarian cancer, treatment with KA-4s combined with DDP reduced energy metabolism and drug resistance, inducing tumor apoptosis. Consequently, KA-4s might be evaluated as a new agent for enhancing the chemotherapeutic efficacy of treatment for ovarian cancer.

Sequential activation of ERα-AMPKα signaling by the flavonoid baicalin down-regulates viral HNF-dependent HBV replication.

Baicalin (BA), a natural component found in many traditional Chinese medicines, exerts protective effects against several viruses. Although our previous studies have revealed that the anti-hepatitis B virus (anti-HBV) activity of BA depends on hepatocyte nuclear factor (HNF) signaling, the specific mechanisms remain unclear. The present study explored the potential signaling mechanisms involved in BA-mediated HBV suppression. Transcriptomic analysis suggested that BA significantly modulates the estrogen receptor (ER) and AMPK signaling pathways in HepG2 cells. The ER alpha (ERα) binding affinity of BA and its estrogen-like agonist activity were subsequently verified through molecular docking assays, BA-ERα affinity detection experiments, ERα luciferase reporter gene assays, and qRT-PCR. ERα knockdown (shRNA) and AMPK inhibition (Compound C and doxorubicin [Dox]) experiments revealed that the sequential activation of the ERα-LKB1-AMPK-HNF signaling axis is essential for the anti-HBV effects of BA. This study indicates that BA may trigger the ERα-AMPKα-HNF pathway to inhibit HBV replication, providing insights into its potential protective mechanisms against other viruses.

ZC3H13-induced the m6A modification of hsa_circ_0081723 promotes cervical cancer progression via AMPK/p53 pathway.

N6-methyladenosine (m6A) modification and circular RNAs (circRNAs) have been confirmed to participate in cervical cancer (CC) progression. However, the function of a novel circRNA, hsa_circ_0081723, has not yet been explored in CC. Therefore, this study aimed to investigate the potential role of hsa_circ_0081723 and its m6A modification in CC. The hsa_circ_0081723 and ZC3H13 expressions were examined by qRT-PCR in the CC tissues, and their prognostic significance was evaluated via Kaplan-Meier Plotter. The role of hsa_circ_0081723 in CC progression was checked by loss-of-function assays. The relative protein levels of AMPK/p53 pathway were determined by western blotting. The interactions of hsa_circ_0081723 and ZC3H13 were verified via MeRIP and RNA stability assays. The hsa_circ_0081723 expression was elevated in CC samples, and its higher levels indicated high histological grade, high FIGO stage, poor differentiation, and poor prognosis. Functionally, silencing hsa_circ_0081723 impaired the malignant behavior of CC cells and enhanced the protein levels of key molecules of the AMPK signaling pathway. Moreover, ZC3H13 was also elevated in CC samples and demonstrated a positive association with hsa_circ_0081723. The relative enrichment of hsa_circ_0081723 m6A and its stability were enhanced in ZC3H13 overexpressed CC cells. Mechanically, ZC3H13 overexpression partially reversed the antitumor effects caused by hsa_circ_0081723 knockdown in CC cells. This study innovatively demonstrates that ZC3H13-mediated m6A modification of hsa_circ_0081723 promotes CC progression by modulating AMPK/p53 pathway. Our findings may contribute to the understanding of the molecular mechanisms underlying CC and offer potential therapeutic targets for clinical treatment.

Metformin Attenuates Vocal Fold Fibrosis via AMPK Signaling.

Vocal fold fibrosis is a challenging condition with no clear consensus on effective treatment methods. Given the demonstrated efficacy of metformin in treating various fibrotic diseases, we hypothesized that metformin could reduce vocal fold fibrosis via the AMPK signaling pathway. In our study, we induced vocal fold injury in rabbits and administered metformin intraperitoneally at a dose of 250mg/kg two weeks post-injury. Four weeks after the injury, vocal folds were excised and analyzed for fibrosis using Masson's trichrome staining, immunohistochemistry, quantitative real-time polymerase chain reaction (qPCR), and Western blotting. In vitro, vocal fold fibroblasts treated with metformin (10μM) ± TGF-β1 (10ng/mL) were utilized to assess metformin's antifibrotic effects, with Compound C (10μM) employed to inhibit AMPK signaling. Our results demonstrate that metformin significantly improved the structural integrity of the vocal fold lamina, reduced collagen deposition, and decreased the expression levels of COL1A1 and α-SMA. Furthermore, metformin activated the AMPK signaling pathway in vocal fold fibroblasts, resulting in decreased expression of COL1A1, α-SMA, TGF-β, Smad2, and Smad3. These findings suggest that metformin attenuates vocal fold fibrosis by modulating the AMPK signaling pathway, providing a foundation for developing new therapeutic options for vocal fold fibrosis.

4-Hydroxydictyolactone alleviates cerebral ischemia injury by regulating neuroinflammation and autophagy via AMPK signaling pathway

BackgroundCerebral ischemia (CI), a cerebrovascular disorder, is a major contributor to disability and mortality. Marine-derived compounds are an important source of new neuroprotective drug candidates. Xenicane-type diterpenes from brown algae of the genus Dictyota have exhibited potential neuroprotective effects against CI injury, attributed to their antioxidant properties. However, whether there are other underlying neuroprotective mechanisms of xenicane diterpenes against CI is still ambiguous. PurposeThis study aims to elucidate the neuroprotective efficacy and mechanism of 4-hydroxydictyolactone (HDTL) in the treatment of CI. MethodsThe LPS-induced BV2 cell model was used for anti-neuroinflammatory activity assay. Tandem Mass Tag (TMT)-based quantitative proteomics was employed to identify underlying mechanisms. The OGD/R-induced SH-SY5Y cell model and a MCAO mice model were used to assess the neuroprotective effect of HDTL against CI in vitro and in vivo. ResultsHDTL reduced inflammation in LPS-stimulated BV2 cells by inhibiting the IKK/IκB/NF-κB pathway and by enhancing AMPK phosphorylation. Additionally, in SH-SY5Y cells treated with OGD/R, HDTL facilitated autophagy and reduced apoptosis. The neuroprotective properties of HDTL were abrogated in AMPK- silenced SH-SY5Y cells. In MCAO mice, HDTL ameliorated CI injury as evidenced by decreases in neurological deficit scores and cerebral infarction. HDTL also promoted autophagy and reduced apoptosis in vivo through both the AMPK/mTOR and IKK/IκB/NF-κB pathways. ConclusionHDTL exhibits neuroprotective effects through regulating the AMPK/mTOR and IKK/IκB/NF-κB pathways. These findings suggest that HDTL is a promising therapeutic candidate for CI treatment.

High soybean dietary supplementation with quercetin improves antioxidant capacity of spotted sea bass Lateolabrax maculatus

This study aimed to examine the effect of quercetin (QUE) on the antioxidant capacity of spotted sea bass that were fed a high soybean meal diet. 44 % fish meal was used as a healthy control, and soybean meal instead of 50 % fish meal induced a negative reaction. On this basis, 0.25, 0.50, 0.75, and 1.00 g/kg QUE were added, respectively. A total of 540 spotted sea bass were randomly allocated into 6 groups and provided with diets that corresponded to their respective groups for a duration of 56 days. The results showed a significant decrease in the antioxidant capacity of spotted sea bass fed a high soybean meal diet. The inclusion of QUE considerably improved the antioxidant capacity of spotted sea bass. This was evidenced by the notable rise in glutathione (GSH) levels in the intestine and liver, as well as the elevated levels of catalase (CAT) and total antioxidant capacity (T-AOC) in the liver. Furthermore, transcriptome results showed that the S-transferase (GST) gene in the glutathione metabolism pathway was significantly down-regulated by high soybean meal, while with the addition of QUE, noteworthy alterations in genes associated with the PI3K-Akt signaling pathway, Foxo signaling pathway, and AMPK signaling pathway. These signaling pathways are involved in signal transduction, apoptosis, and oxidative stress. On the other hand, genes related to energy metabolism, such as phosphoenolpyruvate carboxykinase (PEPCK), were observed to be upregulated. These pathways could potentially contribute to the antioxidant properties of QUE.

Investigation of the regulatory mechanisms of Guiqi Yimu Powder on dairy cow fatty liver cells using a multi-omics approach.

Fatty liver disease in dairy cows is a metabolic disorder that significantly affects their health and productivity, imposing a notable economic burden on the global dairy industry. Traditional Chinese medicine (TCM), characterized by its multi-component and multi-target features, has shown unique advantages in the prevention and treatment of various diseases. Guiqi Yimu Powder, a traditional TCM formula, enhances growth, boosts production efficiency, and strengthens immune function in livestock by regulating antioxidant along with anti-inflammatory pathways. However, its specific regulatory mechanisms on fatty liver in dairy cows remain unclear. This study aims to investigate the molecular-level effects and potential regulatory mechanisms of Guiqi Yimu Powder in a Trimethylamine N-oxide (TMAO) induced fatty liver cell model of dairy cows. We employed a comprehensive analysis integrating transcriptomics, proteomics, metabolomics, and network pharmacology. An in vitro dairy cow fatty liver cell model was established using TMAO to induce lipid accumulation. Cells were treated with the optimal TMAO concentration identified through preliminary experiments, and further divided into a lipid accumulation group and Guiqi Yimu Powder treatment groups. The treatment groups received varying concentrations of Guiqi Yimu Powder (10, 20, 30, 40, or 50 g/L). High-throughput omics sequencing technologies were utilized to perform a comprehensive analysis of the treated cells. Bioinformatics methods were applied to explore the regulatory effects, aiming to elucidate the specific impacts of Guiqi Yimu Powder on lipid metabolism, liver function, and related signaling pathways, thereby providing scientific evidence for its potential application in the prevention and treatment of fatty liver in dairy cows. Guiqi Yimu Powder treatment significantly affected 1,536 genes, 152 proteins, and 259 metabolites. KEGG enrichment analysis revealed that the significantly altered molecules are involved in multiple pathways related to the pathology of fatty liver, including metabolic pathways, glutathione metabolism, hepatitis B, and AMPK signaling pathway (p < 0.05). Notably, joint analysis highlighted the regulatory mechanisms of Guiqi Yimu Powder on glutathione cycling, with L-5-Oxoproline identified as an important metabolic compound. These findings indicate its impact on oxidative stress, energy metabolism, and liver function, suggesting potential therapeutic applications for fatty liver in dairy cows. This study elucidated the regulatory mechanisms of Guiqi Yimu Powder on fatty liver cells in dairy cows, providing new scientific evidence for its potential application in the prevention and treatment of fatty liver disease.

Integration analysis of transcriptome and metabolome revealed the potential mechanism of spermatogenesis in Tibetan sheep (Ovis aries) at extreme high altitude

Testis has an indispensable function in male reproduction of domestic animals. Numerous genes and metabolites were related to testicular development and spermatogenesis. However, little is known about the biological regulation pathways associated with fecundity in male Tibetan sheep. In this study, Testes were collected from Huoba Tibetan sheep (HB, 4614 m) and Gangba Tibetan sheep (GB, 4401 m) at extreme high altitude, and Alpine Merino sheep (AM, 2500 m, control group) at medium-high altitude, investigating the genes and metabolites levels of them. The histological analysis of testicular tissue using hematoxylin-eosin (HE) staining was performed for Tibetan sheep and Alpine Merino sheep, and the testes of them were analyzed by transcriptomics and metabolomics to explore the potential mechanism of testicular development and spermatogenesis. The statistical results showed that the cross-sectional area of testicular seminiferous tubules, diameter of seminiferous tubules, and spermatogenic epithelium thickness were significantly smaller in HB and GB than in AM (P < 0.05). Overall, 5648 differentially expressed genes (DEGs) and 336 differential metabolites (DMs) were identified in three sheep breeds, which were significantly enriched in spermatogenesis and other related pathways. According to integrated metabolomic and transcriptomic analysis, glycolysis/gluconeogenesis, AMPK signaling pathway, and TCA cycle, were predicted to have dramatic effects on the spermatogenesis of Tibetan sheep. Several genes (including Wnt2, Rab3a, Sox9, Hspa8, and Slc38a2) and metabolites (including L-histidinol, Glucose, Fumaric acid, Malic acid, and Galactose) were significantly enriched in pathways related to testicular development and spermatogenesis, and might affect the reproduction of Tibetan sheep by regulating the acrosome reaction, meiotic gene expression, and the production of sex hormones. Our results provide further understanding of the key genes and metabolites involved in testicular development and spermatogenesis in Tibetan sheep.

Inhibition of the FOXO1–ROCK1 axis mitigates cardiomyocyte injury under chronic hypoxia in Tetralogy of Fallot by maintaining mitochondrial quality control

IntroductionPersistent chronic myocardial hypoxia causes disturbances in mitochondrial quality control (MQC), ultimately leading to increased cardiomyocyte injury in patients with Tetralogy of Fallot (TOF). The present study aimed to identify the key effector molecules of cardiomyocyte injury under chronic hypoxia in TOF. MethodsClinical data from TOF patients were collected and whole transcriptome sequencing was performed on myocardial samples. Chronic hypoxia models were established in cardiac-specific knockout mice and cardiomyocytes, and a series of molecular experiments were used to determine the specific mechanisms involved. ResultsClinical cohort data and whole-transcriptome sequencing analysis of myocardial samples from TOF patients revealed that forkhead box O1 (FOXO1) plays an important role in chronic hypoxic cardiomyocyte injury. In a model of chronic hypoxia established in FOXO1 cardiac-specific knockout mice and FOXO1 gene-deficient cardiomyocytes, the AMPK signaling pathway regulates the expression of FOXO1, which in turn disrupts MQC by regulating the transcriptional activation of Rho-associated protein kinase 1 (ROCK1), and increasing the production of mitochondrial ROS, thereby exacerbating damage to cardiomyocytes. Excessive reactive oxygen species (ROS) production during MQC dysfunction further activates Cox7a2L to increase the assembly of the respiratory chain supercomplex. In addition, we found that miR-27b-3p partially binds to the 3′ untranslated region of FOXO1 to exert a protective effect. ConclusionsMaintenance of MQC under chronic hypoxia is achieved through a series of injury-protection mechanisms, suggesting that FOXO1 inhibition may be crucial for future mitigation of chronic hypoxic cardiomyocyte injury in TOF.

Downregulation of glucose-energy metabolism via AMPK signaling pathway in granulosa cells of diminished ovarian reserve patients

Glucose metabolism plays a crucial role in the function of granulosa cells (GCs) and the development of follicles. In cases of diminished ovarian reserve (DOR), alterations in these processes can impact female fertility. This study aims to investigate changes in glucose-energy metabolism in GCs of young DOR patients aged 20 to 35 years and their correlation with the onset and progression of DOR. 72 DOR cases and 75 women with normal ovarian reserve (NOR) as controls were included based on the POSEIDON and Bologna criteria. Samples of GCs and follicular fluid (FF) were collected for a comprehensive analysis involving transcriptomics, metabolomics, RT-qPCR, JC-1 staining, and flow cytometry. The study identified differentially expressed genes and metabolites in GCs of DOR and NOR groups, revealing 7 common pathways related to glucose-energy metabolism, along with 11 downregulated genes and 14 metabolites. Key substances in the glucose-energy metabolism pathway, such as succinate, lactate, NADP, ATP, and ADP, showed decreased levels, with the DOR group exhibiting a reduced ADP/ATP ratio. Downregulation of genes involved in glycolysis (HK, PGK, LDH1), the TCA cycle (CS), and gluconeogenesis (PCK) was observed, along with reduced glucose content and expression of glucose transporter genes (GLUT1 and GLUT3) in DOR GCs. Additionally, decreased AMPK pathway activity and impaired mitochondrial function in DOR suggest a connection between mitochondrial dysfunction and disrupted energy metabolism. Above all, the decline in glucose-energy metabolism in DOR is closely associated with its onset and progression. Reduced glucose uptake and impaired mitochondrial function in DOR GCs lead to internal energy imbalances, hindering the AMPK signaling pathway, limiting energy production and supply, and ultimately impacting follicle development and maturation.

Huangqi-Danshen decoction improves heart failure by regulating pericardial adipose tissue derived extracellular vesicular miR-27a-3p to activate AMPKα2 mediated mitophagy

BackgroundHuangqi-Danshen decoction (HDD) is a classic traditional Chinese medicine for treating heart failure. Pericardial adipose tissue (PAT) has recently gained increasing attention in cardiovascular diseases. PurposeThis study aimed to investigate the effect of pericardial adipose tissue-derived extracellular vesicles on heart failure, the protective effect of HDD on myocardial remodel in heart failure rats, and identify the potential molecular mechanisms involved. MethodsUPLC-MS/MS identified active components of HDD. Extracellular vesicles (EVs) from pericardial adipose tissue of sham-operated and HF rats were identified through transmission electron microscopy, nanoparticle tracking analysis and western blot. EVs were co-cultured with H9c2 cardiomyocytes in order to examine their uptake and effects. MicroRNA sequencing, dual-luciferase reporter assay and PCR were conducted for exploring specific mechanisms of EVs on hypertrophic cardiomyocytes. In vivo, heart failure was modeled in rats via transverse aortic constriction (TAC). In vitro, the hypertrophic cardiomyocyte model were established using Ang II-induced H9c2 cardiomyocytes. ResultsUPLC-MS/MS identified 11 active components in serum of HDD administrated rats. Echocardiography showed HDD improved cardiac function in TAC model rats. HE and Masson staining indicated HDD ameliorated myocardial hypertrophy and fibrosis. MicroRNA sequencing found that HDD treatment resulted in 37 differentially expressed miRNAs (DMEs) (P < 0.05 and |log2FC| ≥ 1). KEGG analysis revealed that DEMs were enriched in the AMPK signaling pathway. PCR identified miR-27a-3p with the greatest difference in AMPK-related DMEs. Dual-luciferase reporter assay and Targetscan website were utilized to identify the target relationship between miR-27a-3p and PRKAA2 (AMPKα2). The miR-27a-3p negatively regulated AMPKα2 to inhibit mitophagy mediated by PINK1/Parkin pathway. HDD inhibited miR-27a-3p secretion from failing heart pericardial adipose tissue-derived extracellular vesicles, thereby improving inflammation, cardiac function, and myocardial remodeling through above pathways. ConclusionHDD inhibited the PAT-derived extracellular vesicular miR-27a-3p in failing hearts to activate AMPK/PINK1/Parkin signaling-mediated mitophagy, which improved cardiomyocyte energy metabolism, myocardial remodeling and heart failure.

Polyoxometalates Ameliorate Metabolic Dysfunction-Associated Steatotic Liver Disease by Activating the AMPK Signaling Pathway.

Metabolic dysfunction-associated steatotic liver disease (MASLD), the most prevalent chronic liver disorder, has garnered increasing attention globally owing to its associated health complications. However, the lack of available therapeutic medications and inadequate management of complications in metabolic dysfunction-associated steatohepatitis (MASH) present significant challenges. There are little studies evaluating the effectiveness of POM in treating MASLD. In this study, we synthesized polyoxometalates (POM) for potential treatment of MASLD. We induced liver disease in mice using two approaches: feeding a high-fat diet (HFD) to establish MASLD or feeding a methionine-choline deficient (MCD) diet to induce hepatic lipotoxicity and MASH. Various metabolic parameters were detected, and biochemical and histological evaluations were conducted on MASLD. Western blotting, qRT-PCR and immunofluorescence assays were used to elucidate the molecular mechanism of POM in the treatment of MASLD. POM therapy resulted in significant improvements in weight gain, dyslipidemia, liver injury, and hepatic steatosis in mice fed a HFD. Notably, in a more severe dietary-induced MASH model with MCD diet, POM significantly attenuated hepatic lipid accumulation, inflammation, and fibrosis. POM treatment effectively attenuated palmitic acid and oleic acid-induced lipid accumulation in HepG2 and Huh7 cells by targeting the AMPK pathway to regulate lipid metabolism, which was confirmed by AMPK inhibitor. Additionally, the activation of AMPK signaling by POM suppressed the expression of lipid synthesis genes, including sterol regulatory element-binding protein 1c (SREBP1c) and SREBP2, while concurrently upregulating the expression of sirtuin 1 (SIRT1) to promote fatty acid oxidation. These findings suggest that POM is a promising therapeutic strategy with high efficacy in multiple MASLD models.

Ultra-high pressure assisted extraction of polysaccharide from Bangia fusco-purpurea: Structure and in vitro hypolipidemic activity

The structure and in vitro hypolipidemic activity of Bangia fusco-purpurea polysaccharide (BFP) assisted extracted with ultra-high pressure (UHP) at 100–600 MPa were studied. Compared to native BFP, UHP assisted extracted BFP had a more loose network structure with higher total sugar and uronic acid contents while less molecular weight (p < 0.05). Moreover, UHP assisted extraction significantly improved the in vitro hypolipidemic and antioxidant activity of BFP. Especially at 400 MPa UHP, the cholesterol adsorption and antioxidant capacities of BFP were increased by approximately 38.02 % and 11.69 %–32.29 %, respectively. BFP with UHP assisted extraction could alleviate oleic acid-induced lipid accumulation and lipid oxidation in HepG2 cells more effectively by activating the AMPK signaling pathway as well as inhibiting PPARγ expression, which was much related with its reduced molecular weight and loose network structure. The findings indicated that UHP assisted extracted BFP has better potential to develop natural hypolipidemic agent.

Expression of the apelin system in the porcine pituitary during the oestrous cycle and early pregnancy and the effect of apelin on LH and FSH secretion

Reproductive success requires considerable energy investment. Research has shown that some adipokines, i.e. the hormones produced in adipose tissue, affect reproductive functions by influencing all structures of the hypothalamic-pituitary-ovarian axis. Apelin is a recently identified member of the adipokine family. To the best of the authors' knowledge, this is the first study to investigate the gene and protein expression of the apelin system (the apelin hormone and the apelin receptor, APJ) in the anterior (AP) and posterior (PP) pituitary lobes of the domestic pig during different phases of the oestrous cycle (days 2 to 3, 10 to 12, 14 to 16, and 17 to 19) and in early pregnancy (days 10 to 11, 12 to 13, 15 to 16, and 27 to 28). It was also assumed that apelin participates in the regulation of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) secretion and influences Akt, MAPK/Erk1/2, and AMPK signalling pathways in the AP during the oestrous cycle. Apelin, APJ mRNAs and proteins were detected in both pituitary lobes. Apelin was identified in gonadotropes, somatotropes, lactotropes, and thyrotropes. The study also revealed that apelin and APJ mRNA/protein levels fluctuate during the oestrous cycle and early gestation. Apelin affects basal, GnRH- and/or insulin-stimulated gonadotropin secretion in some phases of the cycle, as well as the phosphorylation of Akt, MAPK/Erk1/2, and AMPK proteins in AP cells. These findings suggest that apelin may be produced locally in the pituitary and that this gland is receptive to apelin's action. The study also suggest that apelin may influence female reproductive functions by controlling the release of LH and FSH from AP cells, and that it affects Akt, MAPK/Erk1/2, and AMPK signalling pathways.

Polysaccharides from Tremella Fuciformis Enhance Glucose and Lipid Metabolism in HepG2 Cells Through Activating the AMPK Signaling Pathway.

Polysaccharides have gained substantial attention for their diverse biological activities. The present study was conucted to elucidate the effects and molecular mechanisms of Tremella fuciformis-derived polysaccharides (PTP-3a) on glucose and lipid metabolism in palmitic acid (PA) - treated HepG2 cells. Multiple parameters were assessed following PTP-3a treatment, including lipid accumulation, glycogen content, glucose consumption, and enzyme activities, including pyruvate kinase (PK) and hexokinase (HK). Additionally, the expression levels of genes associated with glucose and lipid metabolism was evaluated using western blot analysis. PTP-3a effectively inhibited lipid accumulation, promoted the glucose consumption, increased the amount of cellular glycogen, and enhanced PK and HK activities in PA-treated cells. Furthermore, PTP-3a induced a significant increase in the p-AMPK/AMPK ratio and the expression level of PPARa, while decreasing the expression levels of SREBP, FAS, ACC, and SOCS3. In conclusion, these findings suggested that PTP-3a exerted beneficial effects on glucose and lipid metabolism by activating the AMPK signaling pathway, resulting in the inhibition of lipogenesis, promotion of fatty acid oxidation, and enhancement of cellular glycogen synthesis and glycolysis. These findings hold clinical relevance and provide a foundation for potential treatments for non-alcoholic fatty liver disease (NAFLD) and and related metabolic disorders.

Mangiferin ameliorates polycystic ovary syndrome in rats by modulating insulin resistance, gut microbiota, and ovarian cell apoptosis.

Polycystic ovary syndrome (PCOS) is a complex endocrine and metabolic disorder characterized by hyperandrogenism, prolonged anovulation and polycystic ovaries. However, there are no effective interventions to treat this disorder. As previously shown, mangiferin modulated the AMPK and NLRP3 signal pathways to alleviate nonalcoholic fatty liver disease (NAFLD). In recent years, mangiferin has emerged as a promising drug candidate for treating metabolic diseases. In this study, we evaluated the effects of mangiferin on a letrozole (LET) combined with high-fat diet (HFD)-induced PCOS rat model through estrous cycle detection, serum/tissue biochemical analysis, and hematoxylin and eosin (HE) staining of ovarian tissue. The mechanisms of mangiferin's effects on PCOS rats were analyzed using 16S rRNA sequencing, RNA-seq, western blotting (WB), and immunohistochemical (IHC) staining. Our results displayed that mangiferin showed a promising effect in PCOS rats. It improved lipid metabolism, glucose tolerance, insulin resistance, hormonal imbalance, ovarian dysfunction, and adipocyte abnormalities. RNA-seq analysis indicated that mangiferin may be involved in several signal pathways, including apoptosis, necrosis, and inflammation. Furthermore, western blot and immunohistochemical staining demonstrated that mangiferin regulates Caspase-3 and Cytc, exhibiting anti-apoptotic activity in the ovaries. Additionally, mangiferin significantly altered the gut microbiota community of PCOS rats, changing the abundance of firmicutes, bacteroidota, proteobacteria, and actinobacteria at the phylum level and the abundance of Blautia, Coprococcus, Roseburia, and Pseudomonas at the genus level. In conclusion, mangiferin is a promising and novel therapeutic agent for PCOS as it ameliorates insulin resistance, gut microbiota and ovarian cell apoptosis.

Involvement of the AMPK Pathways in Muscle Development Disparities across Genders in Muscovy Ducks.

The differences in muscle development potential between male and female ducks lead to variations in body weight, significantly affecting the growth of the Muscovy duck meat industry. The aim of this study is to explore the regulatory mechanisms for the muscle development differences between genders. Muscovy ducks of both sexes were selected for measurements of body weight, growth traits, hormone levels, and muscle gene expression. The results show that male ducks compared to females had greater weight and growth traits (p < 0.05). Compared to male ducks, the level of serum testosterone in female ducks was decreased, and the estradiol levels were increased (p < 0.05). The RNA-seq analysis identified 102 upregulated and 49 downregulated differentially expressed genes. KEGG analysis revealed that among the top 10 differentially enriched pathways, the AMPK signaling pathway is closely related to muscle growth and development. Additionally, the mRNA and protein levels of CD36, CPT1A, LPL, and SREBP1 were increased and the P-AMPK protein level decreased in the female ducks compared to the male ducks (p < 0.05). In conclusion, muscle development potential difference between male and female ducks is regulated by sex hormones. This process is likely mediated through the activation of the AMPK pathway.

Bergenin inhibits hepatic fat deposition by activating the AMPK signaling pathway, thereby attenuating alcoholic liver disease

Alcoholic liver disease (ALD) is a prevalent liver condition that arises from prolonged and excessive alcohol intake. Bergenin (BER) is an effective phytotherapeutic agent that exhibits pharmacological properties, including anti-inflammatory and anti-oxidative effects. To establish an in vivo model of ALD, C57BL/6 mice were continuously fed a high-fat diet (HFD) and administered alcohol gavage for 8 weeks, while concurrently administering BER and evaluated for therapeutic effects. After modeling, the therapeutic effects of BER were evaluated by observing histopathological changes and the detection of relevant biochemical indicators in mice. In addition, RNA sequencing of liver tissues was performed to analyze differentially expressed genes and to investigate the associated signaling pathways in order to elucidate the protective mechanisms of BER. These differentially expressed genes were mainly enriched in lipid metabolism pathways and the cytochrome P450 metabolism of exogenous substances. Subsequently, HepG2 was co-treated with sodium oleate (NaOA) and ethanol to establish an in vitro model, and the specific mechanism by which BER ameliorates ALD was further analyzed in depth. AMPK inhibitor, Compound C (CC), was demonstrated to significantly inhibit the regulation of lipid metabolism by BER in vitro. Finally, the differentially expressed genes selected were validated through qRT-PCR and Western blot analysis. Collectively, our findings revealed that BER effectively alleviated liver injury caused by alcohol and HFD in mice, significantly suppressing lipid deposition in ALD, enhancing alcohol metabolism, and mitigating oxidative stress.

Abstract C035: MAGEA6 Oncogene Upregulates MAPK and AMPK Signaling Pathways in Pancreatic Cancer Cells to Promote Survival under Nutrient Stress: Resistance to Glycolysis Inhibition and Increased Susceptibility to Glutamine Depletion

Abstract Introduction: Melanoma-associated antigens (MAGEs) are linked to aggressive disease progression and treatment resistance in many cancers, but their role in pancreatic cancer is not well understood. Our preliminary TCGA data analysis suggested that 10% of pancreatic tumors express MAGEA3/6 and potentially help pancreatic cancer cells survive and grow under nutrient stress. This study aims to uncover the molecular mechanisms of MAGEA3/6 function in pancreatic cancer cell metabolism and disease progression under nutrient-poor conditions. Methods: To understand the role of highly homologous genes MAGEA3 and MAGEA6 in pancreatic cancer, we expressed them in highly glycolytic MIA PaCa-2 pancreatic cancer cells. Cells were then exposed to cancer-related nutritional stressors, including glycolysis inhibition by 2-deoxy-D-glucose (2DG) treatment and glutamine depletion. We analyzed the effect of MAGEA6 expression on cell viability and cell metabolism by Alamar Blue viability assay (BioRad), Seahorse (Agilent), Phenotype MicroArray Mammalian analysis (Biolog), transmission electron microscopy (TEM), and RNA sequencing. To confirm our results, we performed loss-of- function studies in MAGEA3/6-positive cells, including PANC1. Results: We found that, compared to control GFP-expressing cells, MAGEA6-expressing MIA PaCa-2 cells were resistant to glycolysis inhibition with 2-DG. In contrast, they were more susceptible to glutamine depletion, suggesting the important role of MAGEA3/6 in metabolic phenotype and adaptations of pancreatic cancer cells. Further, we showed that MAGEA6-expressing cells exhibited increased ATP production and mitochondrial oxidative phosphorylation, especially under 2DG stress. After 48 hours of 2DG treatment, TEM images revealed significant differences in nuclear, mitochondrial, and ribosomal structures in MAGEA6-cells, further suggesting MAGEA6's role in metabolic adaptation. The Phenotype MicroArray assay demonstrated that α-D-Glucose is the primary nutrient source consumed by both GFP and MAGEA6-expressing cells among the 93 nutrients tested. Additionally, A6 cells utilize Pyruvic Acid as an alternative nutrient source more than GFP cells. To uncover molecular underpinning, we performed RNA sequencing and found that MAGEA6 expression affects transcriptome under glutamine depletion and 2DG treatment. Intriguingly, one of the major differentially regulated biological processes was associated with the upregulation of several signaling pathways, including MAPK and AMPK. Conclusion: Our findings suggest that in pancreatic cancer, MAGEA6 recruits stress and growth factor- dependent MAPK and AMPK pathways to overcome glycolysis inhibition, even in glutamine- depleted conditions, providing a growth advantage. This implies that patients with MAGEA6- positive tumors may benefit from combination therapy targeting metabolism and signaling pathways. Citation Format: Sima Tozandehjani, Barbara Breznik, Klementina Fon Tacer, Miloš Vittori, Juan Sebastian Solano, Sara Uhan. MAGEA6 Oncogene Upregulates MAPK and AMPK Signaling Pathways in Pancreatic Cancer Cells to Promote Survival under Nutrient Stress: Resistance to Glycolysis Inhibition and Increased Susceptibility to Glutamine Depletion [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C035.