Phosphorylation Of acetyl-CoA Carboxylase Research Articles

Coffee Bioactive N-Methylpyridinium: Unveiling Its Antilipogenic Effects by Targeting De Novo Lipogenesis in Human Hepatocytes.

Type 2 diabetes and nonalcoholic fatty liver diseases (NAFLDs) are promoted by insulin resistance (IR), which alters lipid homeostasis in the liver. This study aims to investigate the effect of N-methylpyridinium (NMP), a bioactive alkaloid of coffee brew, on lipid metabolism in hepatocytes. The effect of NMP in modulating lipid metabolism is evaluated at physiological concentrations in a diabetes cell model represented by HepG2 cells cultured in a high-glucose medium. Hyperglycemia triggers lipid droplet accumulation in cells and enhances the lipogenic gene expression, which is transactivated by sterol regulatory element binding protein-1 (SREBP-1). Lipid droplet accumulation alters the redox status and endoplasmic reticulum (ER) stress, leading to the activation of the unfolded protein response and antioxidative pathways by X-Box Binding Protein 1(XBP-1)/eukaryotic Initiation Factor 2 alpha (eIF2α) Protein Kinase RNA-Like ER Kinase and nuclear factor erythroid 2-related factor 2 (NRF2), respectively. NMP induces the phosphorylation of AMP-dependent protein kinase (AMPK) and acetyl-CoA carboxylase α (ACACA), and improves the redox status and ER homeostasis, essential steps to reduce lipogenesis and lipid droplet accumulation. These results suggest that NMP may be beneficial for the management of T2D and NAFLD by ameliorating the cell oxidative and ER homeostasis and lipid metabolism.

Chromofungin mitigates free fatty acids-induced endothelial inflammation via inhibition of NOD-like receptor thermal protein domain-associated protein 3 mediated by adenosine 5'-monophosphate-activated protein kinase.

Free fatty acids (FFAs) have emerged as significant risk factors for atherosclerosis (AS). Prolonged exposure to FFAs induces vascular endothelial injury, including inflammatory responses and oxidative stress, which are central events in AS. Chromofungin (CHR), a peptide derived from chromogranin A (CGA), has been implicated in various biological functions. However, its physiological roles in endothelial biology and its involvement in the pathological development of AS have not been previously reported. In the present study, we investigated the underlying mechanisms through which CHR exerts its beneficial effects on FFA-challenged human aortic endothelial cells (HAECs). We found that treatment with CHR ameliorated the FFA-induced reduction in cell viability and increase in lactate dehydrogenase (LDH) release. Additionally, CHR mitigated oxidative stress by reducing mitochondrial reactive oxygen species (ROS) levels and increasing superoxide dismutase (SOD) activity. Furthermore, exposure to FFAs increased NADPH oxidase (NOX) 4 expression at both the mRNA and protein levels, which were attenuated by CHR in a dose-dependent manner. Notably, CHR reduced the levels of nucleotide-binding domain and leucine-rich repeat-containing (NLR) family pyrin domain containing 3 (NLRP3), apoptosis-associated speck-like protein containing a CARD (ASC), and cleaved caspase-1 (p10), key components of the NLRP3 inflammasome complex, as well as interleukin 1β (IL-1β) and interleukin-18 (IL-18) expression. Mechanistically, it was demonstrated that FFAs reduced the phosphorylation of AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC), which were rescued by CHR in a dose-dependent manner. Conversely, inhibition of AMPK with its specific inhibitor compound C abolished the protective effects of CHR against FFA-induced activation of the NLRP3 inflammasome in HAECs. Based on these findings, we conclude that CHR may serve as a promising agent for maintaining normal endothelial cell function and treating AS.

The Impact of TP53-Induced Glycolysis and Apoptosis Regulator on Prognosis in Hepatocellular Carcinoma: Association with Tumor Microenvironment and Ferroptosis

<b><i>Introduction:</i></b> <i>TP53</i>-induced glycolysis and apoptosis regulator (TIGAR) is a p53 target protein that has critical roles in glycolysis and redox balance. The reports about the effect of TIGAR on prognosis and its biological role in hepatocellular carcinoma (HCC) are limited. <b><i>Methods:</i></b> A total of 386 patients with HCC who had undergone hepatic resection were enrolled. Immunohistochemical staining for TIGAR was performed. Additionally, the regulation of malignant activity and ferroptosis by TIGAR was investigated in vitro. <b><i>Results:</i></b> Patients were divided into TIGAR-positive (<i>n</i> = 80, 20.7%) and -negative (<i>n</i> = 306, 79.3%) groups. TIGAR positivity was significantly correlated with lower albumin, higher α-fetoprotein/ <i>des</i>-gamma-carboxyprothrombin, larger tumor size/number of tumors, and greater proportions of BCLC staging C/single nodular type/poor differentiation/microscopic vascular invasion/microscopic intrahepatic metastasis. In multivariate analysis, TIGAR positivity was an independent prognostic factor (<i>p</i> < 0.0001). In addition, TIGAR positivity was significantly associated with a smaller number of cluster of differentiation (CD) 8-positive T cells (<i>p</i> = 0.0450), larger number of CD68-positive macrophages (<i>p</i> = 0.0058), larger number of programmed death-ligand 1-positive cases (<i>p</i> = 0.0002), and larger number of vessels that encapsulate tumor cluster-positive cases (<i>p</i> = 0.0004). In vitro, <i>TIGAR</i> knockdown decreased cell motility and induced ferroptosis. <i>TIGAR</i> knockdown inhibited the phosphorylation of adenosine monophosphate-activated protein kinase and acetyl-CoA carboxylase. Ferroptosis induced by <i>TIGAR</i> knockdown was inhibited by liproxstatin and baicalein treatment. The combination of <i>TIGAR</i> knockdown and lenvatinib further induced ferroptosis. <b><i>Conclusion:</i></b> High expression of TIGAR impacted the clinical outcome of HCC patients and TIGAR was associated not only with tumor microenvironment but also with resistance to ferroptosis.

Feed supplementation with the seaweed (Ascophllum Nodosum) extract reduces fat deposition in broiler chickens

In poultry industry, the strategies for elevating of protein accretion with minimizing fat deposition have been applied, and seaweed algae has been focused one of the potential candidates. Accordingly, the purpose of this study was to investigate the effects of algae (Ascophllum Nodosum) extract (AE) on the growth performance and body composition of broiler chickens. A total of 240 one-day-old Ross 308 broiler chickens were allotted to 4 dietary treatment groups and fed experimental diets containing different concentrations of AE for 35 d as follows: 0 mg/kg (control, CON), 1,250 mg/kg (LAE), 2,500 mg/kg (MAE), or 5,000 mg/kg (HAE). At the end of the experiment, 40 chickens were sacrificed and samples of their blood, breast muscle, liver, and abdominal fat were collected and analyzed. Growth performance was improved in the LAE group compared to that in the CON (P < 0.05). The weight of abdominal fat was lower in the HAE group than in the CON group (P < 0.05). Serum triglyceride levels were also decreased in the HAE group compared to those in the CON and LAE groups (P < 0.05). Adipocytes were smaller in the HAE group than in all other treatments, and their size distribution was shifted more towards smaller adipocytes compared to those in the LAE group (P < 0.05). Relative mRNA levels in abdominal adipose tissue of fatty acid synthase and stearyl-CoA desaturase, which are involved in fatty acid synthesis, were all downregulated by supplementation with AE (P < 0.05). In addition, the protein levels of peroxisome proliferator-activated receptor gamma were decreased and the ratio of phosphorylated acetyl-CoA carboxylase to total ACC was increased, both of which indicate that lipogenesis was suppressed (P < 0.05). Hepatic transcript levels of sterol regulatory element-binding protein and its downstream enzymes fatty acid synthase and sterol-CoA desaturase were also lower in all AE treatments compared to those in the CON group (P < 0.05). These results indicate that the seaweed algae (Ascophllum Nodosum) extract reduces fat accumulation in both adipose tissue and the liver by modulating lipogenesis.

Mammalian target of differentiation-inducing factor-1 is mitochondrial malate dehydrogenase for activation of AMP-activated protein kinase and induction of mitochondrial fission

AimsDifferentiation-inducing factor-1 (DIF-1) is a polyketide produced by Dictyostelium discoideum that inhibits growth and migration, while promoting the differentiation of Dictyostelium stalk cells through unknown mechanisms. DIF-1 localizes in stalk mitochondria. In addition to its effect on Dictyostelium, DIF-1 also inhibits growth and migration, and induces mitochondrial fission followed by mitophagy in mammalian cells, at least in part by activating AMP-activated protein kinase (AMPK). In a previous study, we found that DIF-1 binds to mitochondrial malate dehydrogenase (MDH2) and inhibits its activity in HeLa cells. In the present study, we investigated whether MDH2 serves as a pharmacological target of DIF-1 in mammalian cells. Main methodsTo examine the enzymatic activity of MDH, mitochondrial morphology, and molecular mechanisms of DIF-1 action, we conducted an MDH reverse reaction assay, immunofluorescence staining, western blotting, and RNA interference using mammalian cells such as human umbilical vein endothelial cells, human cervical cancer cells, mouse endothelial cells, and mouse breast cancer cells. Key findingsDIF-1 inhibited mitochondrial but not cytoplasmic MDH activity. Similar to DIF-1, LW6, an authentic MDH2 inhibitor, induced phosphorylation of AMPK, resulting in the phosphorylation of acetyl-CoA carboxylase (ACC) and the dephosphorylation of p70 S6 kinase with approximately the same potency. DIF-1 and LW6 induced mitochondrial fission. Furthermore, MDH2 knockdown using siRNA reproduced the DIF-1 action on the AMPK signaling and mitochondrial morphology. Conversely, an AMPK inhibitor prevented DIF-1-induced mitochondrial fission. SignificanceWe propose that MDH2 is a mammalian target of DIF-1 for the activation of AMPK and induction of mitochondrial fission.

Lactobacillus rhamnosus 069 and Lactobacillus brevis 031: Unraveling Strain-Specific Pathways for Modulating Lipid Metabolism and Attenuating High-Fat-Diet-Induced Obesity in Mice.

Obesity is a global health crisis, marked by excessive fat in tissues that function as immune organs, linked to microbiota dysregulation and adipose inflammation. Investigating the effects of Lactobacillus rhamnosus SG069 (LR069) and Lactobacillus brevis SG031 (LB031) on obesity and lipid metabolism, this research highlights adipose tissue's critical immune-metabolic role and the probiotics' potential against diet-induced obesity. Mice fed a high-fat diet were treated with either LR069 or LB031 for 12 weeks. Administration of LB031 boosted lipid metabolism, indicated by higher AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC) phosphorylation, and increased the M2/M1 macrophage ratio, indicating LB031's anti-inflammatory effect. Meanwhile, LR069 administration not only led to significant weight loss by enhancing lipolysis which evidenced by increased phosphorylation of hormone-sensitive lipase (HSL) and adipose triglyceride lipase (ATGL) but also elevated Akkermansia and fecal acetic acid levels, showing the gut microbiota's pivotal role in its antiobesity effects. LR069 and LB031 exhibit distinct effects on lipid metabolism and obesity, underscoring their potential for precise interventions. This research elucidates the unique impacts of these strains on metabolic health and highlights the intricate relationship between gut microbiota and obesity, advancing our knowledge of probiotics' therapeutic potential.

The AMPK activator ATX-304 alters cellular metabolism to protect against cisplatin-induced acute kidney injury

Acute kidney injury (AKI) disrupts energy metabolism. Targeting metabolism through AMP-activated protein kinase (AMPK) may alleviate AKI. ATX-304, a pan-AMPK activator, was evaluated in C57Bl/6 mice and tubular epithelial cell (TEC) cultures. Mice received ATX-304 (1 mg/g) or control chow for 7 days before cisplatin-induced AKI (CI-AKI). Primary cultures of tubular epithelial cells (TECs) were pre-treated with ATX-304 (20 µM, 4 h) prior to exposure to cisplatin (20 µM, 23 h). ATX-304 increased acetyl-CoA carboxylase phosphorylation, indicating AMPK activation. It protected against CI-AKI measured by serum creatinine (control 0.05 + 0.03 mM vs ATX-304 0.02 + 0.01 mM, P = 0.03), western blot for neutrophil gelatinase-associated lipocalin (NGAL) (control 3.3 + 1.8-fold vs ATX-304 1.2 + 0.55-fold, P = 0.002), and histological injury (control 3.5 + 0.59 vs ATX-304 2.7 + 0.74, P = 0.03). In TECs, pre-treatment with ATX-304 protected against cisplatin-mediated injury, as measured by lactate dehydrogenase release, MTS cell viability, and cleaved caspase 3 expression. ATX-304 protection against cisplatin was lost in AMPK-null murine embryonic fibroblasts. Metabolomic analysis in TECs revealed that ATX-304 (20 µM, 4 h) altered 66/126 metabolites, including fatty acids, tricarboxylic acid cycle metabolites, and amino acids. Metabolic studies of live cells using the XFe96 Seahorse analyzer revealed that ATX-304 increased the basal TEC oxygen consumption rate by 38%, whereas maximal respiration was unchanged. Thus, ATX-304 protects against cisplatin-mediated kidney injury via AMPK-dependent metabolic reprogramming, revealing a promising therapeutic strategy for AKI.

Liraglutide promotes UCP1 expression and lipolysis of adipocytes by promoting the secretion of irisin from skeletal muscle cells

Although Liraglutide (Lira) increases serum irisin levels in type 2 diabetes mellitus (T2DM), it is unclear whether it induces expression of uncoupling protein 1 (UCP1) of adipocytes via promoting irisin secretion from skeletal muscle. Male T2DM rats were treated with 0.4 mg/kg/d Lira twice a day for 8 weeks, and the protein expression of phosphorylated AMP kinase (p-AMPK), phosphorylated acetyl-CoA carboxylase 1 (p-ACC1) and UCP1 in white adipose tissues were detected. Differentiated C2C12 cells were treated with palmitic acid (PA) and Lira to detect the secretion of irisin. Differentiated 3T3-L1 cells were treated with irisin, supernatant from Lira-treated C2C12 cells, Compound C or siAMPKα1, the triglyceride (TG) content and the related gene expression were measured. The transcriptome in irisin-treated differentiated 3T3-L1 cells was analyzed. Lira elevated serum irisin levels, decreased the adipocyte size and increased the protein expression of UCP1, p-AMPK and p-ACC1 in WAT. Moreover, it promoted the expression of PGC1α and FNDC5, the secretion of irisin in PA-treated differentiated C2C12 cells. The irisin and supernatant decreased TG synthesis and promoted the expression of browning- and lipolysis-related genes in differentiated 3T3-L1 cells. While Compound C and siAMPKα1 blocked AMPK activities and expression, irisin partly reversed the pathway. Finally, the transcriptome analysis indicated that differently expressed genes are mainly involved in browning and lipid metabolism. Overall, our findings showed that Lira modulated muscle-to-adipose signaling pathways in diabetes via irisin-mediated AMPKα/ACC1/UCP1/PPARα pathway. Our results suggest a new mechanism for the treatment of T2DM by Lira.

AMPK activation modulates IL-36-induced inflammatory responses by regulating IκBζ expression in the skin.

The interleukin (IL)-36 pathway is a critical player in the pathogenesis of pustular psoriasis. However, therapies targeting this pathway are limited or unaffordable (e.g. the anti-IL-36 receptor antibody). AMP-activated protein kinase (AMPK), a regulator of cellular energy and metabolism, is known to participate in inflammatory diseases. However, its role in IL-36-induced skin inflammation remains unclear. Therefore, we sought to investigate the role of AMPK signals in regulating IL-36-induced responses in the skin. IL-36-stimulated primary normal human epidermal keratinocytes (NHEKs) and IL-36-injected (intradermally) BALB/c mice served as the cell and animal models, respectively. Additionally, 5-aminoimidazole-4-carboxamide riboside (AICAR) and A769662 served as AMPK activators. AICAR and A769662 significantly suppressed the IL-36-induced IL-8 (CXCL8) and CCL20 production from NHEKs. IL-36-induced IκBζ protein expression was prominently reduced and IKK/IκBα phosphorylation was attenuated by AICAR and A769662. Conversely, AMPKα knockdown increased IκBζ protein expression and IKK/IκBα phosphorylation in IL-36-treated NHEKs. Furthermore, AICAR and A769662 enhanced IL-36-induced-IκBζ protein degradation via the proteasome-dependent but not the lysosome-dependent pathway. Pretreatment of NHEKs with IL-36 slightly suppressed the AICAR- and A769662-triggered phosphorylation of AMPK and acetyl-CoA carboxylase. In the mouse model, topical application of AICAR significantly reduced ear swelling, redness, epidermal thickening, neutrophil infiltration and inflammatory and antimicrobial peptide gene expression. AMPK activation suppresses IL-36-induced IL-8 and CCL20 release by regulating IκBζ expression in keratinocytes and reduces IL-36-induced skin inflammation in mice, suggesting that AMPK activation is a potential strategy for treating patients with IL-36-mediated inflammatory skin disorders.

Bacoside-A repressed the differentiation and lipid accumulation of 3T3-L1 preadipocytes by modulating the expression of adipogenic genes.

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.

CDK6 inhibits de novo lipogenesis in white adipose tissues but not in the liver

Increased de novo lipogenesis (DNL) in white adipose tissue is associated with insulin sensitivity. Under both Normal-Chow-Diet and High-Fat-Diet, mice expressing a kinase inactive Cyclin-dependent kinase 6 (Cdk6) allele (K43M) display an increase in DNL in visceral white adipose tissues (VAT) as compared to wild type mice (WT), accompanied by markedly increased lipogenic transcriptional factor Carbohydrate-responsive element-binding proteins (CHREBP) and lipogenic enzymes in VAT but not in the liver. Treatment of WT mice under HFD with a CDK6 inhibitor recapitulates the phenotypes observed in K43M mice. Mechanistically, CDK6 phosphorylates AMP-activated protein kinase, leading to phosphorylation and inactivation of acetyl-CoA carboxylase, a key enzyme in DNL. CDK6 also phosphorylates CHREBP thus preventing its entry into the nucleus. Ablation of runt related transcription factor 1 in K43M mature adipocytes reverses most of the phenotypes observed in K43M mice. These results demonstrate a role of CDK6 in DNL and a strategy to alleviate metabolic syndromes.

Gypenoside XIII regulates lipid metabolism in HepG2 hepatocytes and ameliorates nonalcoholic steatohepatitis in mice.

Gypenoside XIII is isolated from Gynostemma pentaphyllum (Thunb.) Makino. In mice, G. pentaphyllum extract and gypenoside LXXV have been shown to improve non-alcoholic steatohepatitis (NASH). This study investigated whether gypenoside XIII can regulate lipid accumulation in fatty liver cells or attenuate NASH in mice. We used HepG2 hepatocytes to establish a fatty liver cell model using 0.5 mM oleic acid. Fatty liver cells were treated with different concentrations of gypenoside XIII to evaluate the molecular mechanisms of lipid metabolism. In addition, a methionine/choline-deficient diet induced NASH in C57BL/6 mice, which were given 10 mg/kg gypenoside XIII by intraperitoneal injection. In fatty liver cells, gypenoside XIII effectively suppressed lipid accumulation and lipid peroxidation. Furthermore, gypenoside XIII significantly increased SIRT1 and AMPK phosphorylation to decrease acetyl-CoA carboxylase phosphorylation, reducing fatty acid synthesis activity. Gypenoside XIII also decreased lipogenesis by suppressing sterol regulatory element-binding protein 1c and fatty acid synthase production. Gypenoside XIII also increased lipolysis and fatty acid β-oxidation by promoting adipose triglyceride lipase and carnitine palmitoyltransferase 1, respectively. In an animal model of NASH, gypenoside XIII effectively decreased the lipid vacuole size and number and reduced liver fibrosis and inflammation. These findings suggest that gypenoside XIII can regulate lipid metabolism in fatty liver cells and improve liver fibrosis in NASH mice. Therefore, gypenoside XIII has potential as a novel agent for the treatment of NASH.

Low phosphorus increases hepatic lipid deposition, oxidative stress and inflammatory response via Acetyl-CoA carboxylase-dependent manner in zebrafish liver cells

Acetyl-CoA carboxylase (ACC) plays a regulatory role in both fatty acid synthesis and oxidation, controlling the process of lipid deposition in the liver. Given that existing studies have shown a close relationship between low phosphorus (P) and hepatic lipid deposition, this study was conducted to investigate whether ACC plays a crucial role in this relationship. Zebrafish liver cell line (ZFL) was incubated under low P medium (LP, P concentration: 0.77 mg/L) or adequate P medium (AP, P concentration: 35 mg/L) for 240 h. The results showed that, compared with AP-treated cells, LP-treated cells displayed elevated lipid accumulation, and reduced fatty acid β-oxidation, ATP content, and mitochondrial mass. Furthermore, transcriptomics analysis revealed that LP-treated cells significantly increased lipid synthesis (Acetyl-CoA carboxylases (acc), Stearyl coenzyme A dehydrogenase (scd)) but decreased fatty acid β-oxidation (Carnitine palmitoyltransferase I (cptI)) and (AMP-activated protein kinase (ampk)) mRNA levels compared to AP-treated cells. The phosphorylation of AMPK and ACC, and the protein expression of CPTI were significantly decreased in LP-treated cells compared with those in AP-treated cells. After 240 h of LP treatment, PF-05175157 (an ACC inhibitor) was supplemented in the LP treatment for an additional 12 h. PF-05175157-treated cells showed higher phosphorylation of ACC, higher protein expression of CPTI, and lower protein expression of FASN, lower TG content, enhanced fatty acid β-oxidation, increased ATP content, and mitochondrial mass compared with LP-treated cells. PF-05175157 also relieved the LP-induced oxidative stress and inflammatory response. Overall, these findings suggest that ACC is a promising target for treating LP-induced elevation of lipid deposition in ZFL, and can alleviate oxidative stress and inflammatory response.

Independent and combined effects of calorie restriction and AICAR on glucose uptake and insulin signaling in skeletal muscles from 24-month-old female and male rats.

We assessed the effects of two levels of calorie restriction (CR; eating either 15% or 35% less than ad libitum, AL, food intake for 8 weeks) by 24-month-old female and male rats on glucose uptake (GU) and phosphorylation of key signaling proteins (Akt; AMP-activated protein kinase, AMPK; Akt substrate of 160kDa, AS160) measured in isolated skeletal muscles that underwent four incubation conditions (without either insulin or AICAR, an AMPK activator; with AICAR alone; with insulin alone; or with insulin and AICAR). Regardless of sex: (1) neither CR group versus the AL group had greater GU by insulin-stimulated muscles; (2) phosphorylation of Akt in insulin-stimulated muscles was increased in 35% CR versus AL rats; (3) prior AICAR treatment of muscle resulted in greater GU by insulin-stimulated muscles, regardless of diet; and (4) AICAR caused elevated phosphorylation of acetyl CoA carboxylase, an indicator of AMPK activation, in all diet groups. There was a sexually dimorphic diet effect on AS160 phosphorylation, with 35% CR exceeding AL for insulin-stimulated muscles in male rats, but not in female rats. Our working hypothesis is that the lack of a CR-effect on GU by insulin-stimulated muscles was related to the extended duration of the ex vivo incubation period (290 min compared to 40-50 min that was previously reported to be effective). The observed efficacy of prior treatment of muscles with AICAR to improve glucose uptake in insulin-stimulated muscles supports the strategy of targeting AMPK with the goal of improving insulin sensitivity in older females and males.

Small-molecule agonist AdipoRon alleviates diabetic retinopathy through the AdipoR1/AMPK/EGR4 pathway.

Diabetes mellitus (DM) is a progressive disease that involves multiple organs due to increased blood glucose, and diabetic retinopathy (DR) is the main complication of DM in the eyes and causes irreversible vision loss. In the pathogenesis of diabetic vascular disease, oxidative stress caused by hyperglycemia plays an important role in Müller cell impairment. In recent years, AdipoRon, an adiponectin analog that demonstrated important physiological functions in obesity, diabetes, inflammation, and cardiovascular diseases, demonstrated cellular protection from apoptosis and reduced inflammatory damage through a receptor-dependent mechanism. Here, we investigated how AdipoRon reduced oxidative stress and apoptosis in Müller glia in a high glucose environment. By binding to adiponectin receptor 1 on Müller glia, AdipoRon activated 5' adenosine monophosphate-activated protein kinase (AMPK)/acetyl-CoA carboxylase phosphorylation downstream, thereby alleviating oxidative stress and eventual apoptosis of cells and tissues. Transcriptome sequencing revealed that AdipoRon promoted the synthesis and expression of early growth response factor 4 (EGR4) and inhibited the cellular protective effects of AdipoRon in a high-glucose environment by reducing the expression of EGR4. This indicated that AdipoRon played a protective role through the EGR4 and classical AMPK pathways. This provides a new target for the early treatment of DR.

Anti-obesity effects of a standardized ethanol extract of Eisenia bicyclis by regulating the AMPK signaling pathway in 3T3-L1 cells and HFD-induced mice.

Obesity requires treatment to mitigate the potential development of further metabolic disorders, including diabetes, hyperlipidemia, tumor growth, and non-alcoholic fatty liver disease. We investigated the anti-obesity effect of a 30% ethanol extract of Eisenia bicyclis (Kjellman) Setchell (EEB) on 3T3-L1 preadipocytes and high-fat diet (HFD)-induced obese C57BL/6 mice. Adipogenesis transcription factors including peroxisome proliferator-activated receptor (PPAR)γ, CCAAT/enhancer-binding protein-alpha (C/EBPα), and sterol regulatory element-binding protein-1 (SREBP-1) were ameliorated through the AMP-activated protein kinase (AMPK) pathway by EEB treatment in differentiated 3T3-L1 cells. EEB attenuated mitotic clonal expansion by upregulating cyclin-dependent kinase inhibitors (CDKIs) while downregulating cyclins and CDKs. In HFD-fed mice, EEB significantly decreased the total body weight, fat tissue weight, and fat in the tissue. The protein expression of PPARγ, C/EBPα, and SREBP-1 was increased in the subcutaneous fat and liver tissues, while EEB decreased the expression levels of these transcription factors. EEB also inhibited lipogenesis by downregulating acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS) expression in the subcutaneous fat and liver tissues. Moreover, the phosphorylation of AMPK and ACC was downregulated in the HFD-induced mouse group, whereas the administration of EEB improved AMPK and ACC phosphorylation; thus, EEB treatment may be related to the AMPK pathway. Histological analysis showed that EEB reduced the adipocyte size and fat accumulation in subcutaneous fat and liver tissues, respectively. EEB promotes thermogenesis in brown adipose tissue and improves insulin and leptin levels and blood lipid profiles. Our results suggest that EEB could be used as a potential agent to prevent obesity.

IRW improves diet-induced non-alcoholic fatty liver disease by reducing steatosis associated with increased capacity for oxidative phosphorylation

Non-alcoholic fatty liver disease (NAFLD), the hepatic manifestation of the metabolic syndrome, remains without approved pharmacological treatment. Food-derived bioactive peptides can aid in the management of metabolic conditions including hypertension, obesity and insulin resistance. IRW (isoleucine-arginine-tryptophan) is a tripeptide produced from egg white with angiotensin converting enzyme-inhibitory properties. IRW supplementation elicits antihypertensive effects, improves skeletal muscle insulin signaling and glucose tolerance while reducing body weight gain. In this study, we hypothesized that IRW supplementation would prevent high-fat diet (HFD)-induced NAFLD by modulating hepatic lipid metabolism and increasing mitochondrial content. We found that IRW prevents diet-induced NAFLD, while rosiglitazone (ROSI) treatment worsens it. IRW decreases hepatic triglyceride content and lipid droplet size compared to HFD and ROSI. IRW increases the hepatic mitochondrial complexes and citrate synthase activity, phosphorylation of 5'-AMP-activated protein kinase and microsomal triglyceride transfer protein abundance compared to HFD. Compared with ROSI, IRW increases phosphorylated acetyl CoA carboxylase and mitochondrial complexes. Overall, the hypothesis is supported by these findings.

Design and Synthesis of Novel Indole Ethylamine Derivatives as a Lipid Metabolism Regulator Targeting PPARα/CPT1 in AML12 Cells.

Peroxisome proliferator-activated receptor alpha (PPARα) and carnitine palmitoyltransferase 1 (CPT1) are important targets of lipid metabolism regulation for nonalcoholic fatty liver disease (NAFLD) therapy. In the present study, a set of novel indole ethylamine derivatives (4, 5, 8, 9) were designed and synthesized. The target product (compound 9) can effectively activate PPARα and CPT1a. Consistently, in vitro assays demonstrated its impact on the lipid accumulation of oleic acid (OA)-induced AML12 cells. Compared with AML12 cells treated only with OA, supplementation with 5, 10, and 20 μM of compound 9 reduced the levels of intracellular triglyceride (by 28.07%, 37.55%, and 51.33%) with greater inhibitory activity relative to the commercial PPARα agonist fenofibrate. Moreover, the compound 9 supplementations upregulated the expression of hormone-sensitive triglyceride lipase (HSL) and adipose triglyceride lipase (ATGL) and upregulated the phosphorylation of acetyl-CoA carboxylase (ACC) related to fatty acid oxidation and lipogenesis. This dual-target compound with lipid metabolism regulatory efficacy may represent a promising type of drug lead for NAFLD therapy.

Diisoprenyl-cyclohexene-type meroterpenoids from a mangrove endophytic fungus Aspergillus sp. GXNU-Y65 and their anti-nonalcoholic steatohepatitis activity in AML12 cells

Nine previously undescribed diisoprenyl-cyclohexene-type meroterpenoids, aspergienynes A-I, together with five known analogues, were obtained from the mangrove endophytic fungal strain Aspergillus sp. GXNU-Y65. The diisoprenyl-cyclohexene-type meroterpenoids were elucidated based on multispectroscopic analysis, and the previously undescribed compounds’ absolute configurations were established via electronic circular dichroism calculations. Biological activity results indicated that aspergienyne C (compound 3) had strong anti-nonalcoholic steatohepatitis activity against AML12 cells treated with PA (Palmitic acid) + OA (Oleic acid). At the same concentration of 20 μM, 3 significantly reduced triglyceride (TG) content compared with fenofibrate (positive control) in PA + OA treated AML12 cells, and obviously increased phosphorylation of acetyl-CoA carboxylase.

The combination of Ephedrae herba and coixol from Coicis semen attenuate adiposity via glucocorticoid receptor regulation

The enhanced therapeutic effects and mechanisms of certain herbal combination in various herbal prescriptions are mostly unclear. A combination of two herbs, namely Ephedrae herba (EH) and Coicis semen (CS), has been commonly prescribed for obesity. In our previous work, the combination of EH and CS was studied using network pharmacological approach to predict its pharmacological targets and in vitro experiments to evaluate its efficacy on obesity. Although we demonstrated enhanced anti-adiposity effects of the combination on matured adipocytes, the molecular mechanisms and contributing compounds underlying the effects of EH-CS combination on adiposity or adipogenesis were not fully elucidated. The current study adopted integrated bioinformatics analysis to precisely validate potential targets of EH-CS by screening differentially expressed genes (DEGs) of morbid obesity patients from NCBI gene expression omnibus (GEO). Based on the functional cluster analysis of down-regulated DEGs, the anti-adipogenesis mechanism of EH-CS combination was speculated with KEGG enrichment analysis. Furthermore, we investigated the combinational effects of EH and coixol, or stigmasterol, the two compounds in CS which were expected to have main beneficial effects in metabolic diseases. Moreover, distinct effect of the combination on transcriptional activity of glucocorticoid receptor (GR) was investigated using electrophoretic mobility shift assay (EMSA). The EH-CS combination was predicted to modulate down-regulated genes which are involved in KEGG pathways crucial to metabolic disease in morbidly obese individuals. The combination of EH with CS compounds significantly increased the phosphorylation of acetyl-coA carboxylase (ACC), AMP-activated protein kinase (AMPK), and protein kinase B (AKT) in 3T3-L1 cells and decreased intracellular lipid accumulation. The two CS compounds significantly increased the anti-adipogenesis/lipogenesis effects of EH by inhibiting the gene expression levels. Finally, the combination of EH and coixol inhibited dexamethasone-induced GR translocation to the nucleus and transcriptional binding activity in adipocytes. The combination of EH and CS could be considered a therapeutic strategy for treating metabolic diseases, including obesity.