Supercritical CO2 fluid extract from Stellariae Radix ameliorates 2,4-dinitrochlorobenzene-induced atopic dermatitis by inhibit M1 macrophages polarization via AMPK activation

Yin chai hu (Radix Stellariae) is a root medicine that is frequently used in Chinese traditional medicine to treat fever and malnutrition. In modern medicine, it has been discovered to have anti-inflammatory, anti-allergic, and anticancer properties. In a previous study, we were able to extract lipids from Stellariae Radix using supercritical CO2 extraction (SRE), and these sterol lipids accounted for up to 88.29% of the extract. However, the impact of SRE on the development of atopic dermatitis (AD) has not yet been investigated. This study investigates the inhibitory effects of SRE on AD development using a 2,4-dinitrochlorobenzene (DNCB)-induced AD mouse model. Treatment with SRE significantly reduced the dermatitis score and histopathological changes compared with the DNCB group. The study found that treatment with SRE resulted in a decrease of pro-inflammatory cytokines TNF-α, CXC-10, IL-12, and IL-1β in skin lesions. Additionally, immunohistochemical analysis revealed that SRE effectively suppressed M1 macrophage infiltration into the AD lesion. Furthermore, the anti-inflammatory effect of SRE was evaluated in LPS + INF-γ induced bone marrow-derived macrophages (BMDMs) M1 polarization, SRE inhibited the production of TNF-α, CXC-10, IL-12, and IL-1β and decreased the expression of NLRP3. Additionally, SRE was found to increase p-AMPKT172, but had no effect on total AMPK expression, after administration of the AMPK inhibitor Compound C, the inhibitory effect of SRE on M1 macrophages was partially reversed. The results indicate that SRE has an inhibitory effect on AD, making it a potential therapeutic agent for this atopic disorder.

Dauferulins A-L, daucane-type sesquiterpenes from the roots of Ferula communis: Their structures and biological activities

Phytochemical study on the roots of a medicinal plant Ferula communis L. (Apiaceae) resulted in the isolation of 20 sesquiterpenes including 12 previously undescribed compounds, dauferulins A-L (1-12). The detailed spectroscopic analysis revealed 1-12 to be daucane-type sesquiterpenes with a p-methoxybenzoyloxy group at C-6. The absolute configurations of 1-12 were deduced by analysis of the ECD spectra. Dauferulins A-L (1-12), known sesquiterpenes (13-20), and analogues (14a-14l) derived from 6-O-p-methoxybenzoyl-10α-angeloyloxy-jeaschkeanadiol (14) were evaluated for their effects on AMPK phosphorylation in human hepatoma HepG2 cells as well as inhibitory activities against erastin-induced ferroptosis on human hepatoma Hep3B cells and IL-1β production from LPS-treated murine microglial cells.

Synthesis and biological evaluation of 2'-hydroxychalcone derivatives as AMPK activators

A series of 2'-hydroxychalcone derivatives with various substituents on B-ring were synthesized and evaluated for AMP-activated protein kinase (AMPK) activation activity in podocyte cells. The results displayed that hydroxy, methoxy and methylenedioxy groups on B-ring could enhance the activitiy better than O-saturated alkyl, O-unsaturated alkyl or other alkoxy groups. Compounds 27 and 29 possess the highest fold change of 2.48 and 2.73, respectively, which were higher than those of reference compound (8) (1.28) and metformin (1.88). Compounds 27 and 29 were then subjected to a concentration-response study to obtain the EC50 values of 2.0 and 4.8 µM, respectively and MTT assays also showed that cell viability was not influenced by the exposure of podocytes to compounds 27 and 29 at concentrations up to 50 μM. In addition, compound 27 was proved to activate AMPK via calcium/calmodulin-dependent protein kinase kinase β (CaMKKβ)-dependent pathway without affecting intracellular calcium levels. The computational study showed that the potent compounds exhibited stronger ligand-binding strength to CaMKKβ, particularly compounds 27 (-8.4 kcal/mol) and 29 (-8.0 kcal/mol), compared to compound 8 (-7.5 kcal/mol). Fragment molecular orbital (FMO) calculation demonstrated that compound 27 was superior to compound 29 due to the presence of methyl group, which amplified the binding by hydrophobic interactions. Therefore, compound 27 would represent a promising AMPK activator for further investigation of the treatment of diabetes and diabetic nephropathy.

Lactobacillus plantarum and Bifidobacterium longum Alleviate Liver Injury and Fibrosis in Mice by Regulating NF-κB and AMPK Signaling

In a preliminary study, live biotherapeutic products (LBPs) Lactobacillus plantarum LC27 and Bifidobacterium longum LC67 inhibited the secretion of alanine transaminase (ALT) and aspartate transaminase (AST) in LPS-stimulated HepG2 cells, while Escherichia coli K1 (Ec) increased ALT and ALT secretion. Therefore, we examined the effects of LC27 and LC67 on LPS-induced liver injury and fibrosis in mice and the correlation between their biomarkers in cell and animal experiments. Orally administered LC27 or LC67 significantly decreased blood ALT, AST, γ-glutamyl transferase (γGTP), TNF-α, triglyceride (TG), total cholesterol (TCh), total bile acid, and LPS levels, liver TNF-α, toll-like receptor-4 gene (Tlr4), α-smooth muscle actin (αSMA), and collagen-1 expression and αSMA+GFAP+ and NF-κB+F4/80+ cell populations, and colonic Tlr4, TNF-α, and IL-6 expression and NF-κB-positive cell population in LPS-treated mice. Furthermore, they increased AMPKa phosphorylation in the liver and colon. However, Ec increased the expression of TNF-α and IL-6 in blood, liver, and colon. The suppression of LPS-stimulated ALT and AST secretion in HepG2 cells by LBPs was positively correlated with their ameliorating effects on LPS-induced blood γGTP, ALT, and AST levels and liver αSMA and collagen-1 expression in mice. Based on these findings, LC27 and LC67 may improve liver injury and fibrosis by regulating NF-κB and AMPK signaling pathway and a protocol that can assay the inhibitory activity of LBPs on LPS-induced ALT and AST secretion in HepG2 may be useful for guessing their antihepatitic effects in the in vivo experiments.

[Extracellular Matrix Stiffness Induces Mitochondrial Morphological Heterogeneity via AMPK Activation]

Objective

To investigate the mechanical responses of mitochondrial morphology to extracellular matrix stiffness in human mesenchymal stem cells (hMSCs) and the role of AMP-activated protein kinase (AMPK) in the regulation of mitochondrial mechanoresponses.

Methods

Two polyacrylamide (PAAm) hydrogels, a soft one with a Young's modulus of 1 kPa and a stiff one of 20 kPa, were prepared by changing the monomer concentrations of acrylamide and bis-acrylamide. Then, hMSCs were cultured on the soft and stiff PAAm hydrogels and changes in mitochondrial morphology were observed using a laser confocal microscope. Western blot was performed to determine the expression and activation of AMPK, a protein associated with mitochondrial homeostasis. Furthermore, the activation of AMPK was regulated on the soft and stiff matrixes by AMPK activator A-769662 and the inhibitor Compound C, respectively, to observe the morphological changes of mitochondria.

Results

The morphology of the mitochondria in hMSCs showed heterogeneity when there was a change in gel stiffness. On the 1 kPa soft matrix, 74% mitochondria exhibited a dense, elongated filamentous network structure, while on the 20 kPa stiff matrix, up to 63.3% mitochondria were fragmented or punctate and were sparsely distributed. Western blot results revealed that the phosphorylated AMPK (p-AMPK)/AMPK ratio on the stiff matrix was 1.6 times as high as that on the soft one. Immunofluorescence assay results revealed that the expression of p-AMPK was elevated on the hard matrix and showed nuclear localization, which indicated that the activation of intracellular AMPK increased continuously along with the increase in extracellular matrix stiffness. When the hMSCs on the soft matrix were treated with A-769662, an AMPK activator, the mitochondria transitioned from a filamentous network morphology to a fragmented morphology, with the ratio of filamentous network decreasing from 74% to 9.5%. Additionally, AMPK inhibition with Compound C promoted mitochondrial fusion on the stiff matrix and significantly reduced the generation of punctate mitochondria.

Conclusion

Extracellular matrix stiffness regulates mitochondrial morphology in hMSCs through the activation of AMPK. Stiff matrix promotes the AMPK activation, resulting in mitochondrial fission and the subsequent fragmentation of mitochondria. The impact of matrix stiffness on mitochondrial morphology can be reversed by altering the level of AMPK phosphorylation.

Anti-adipogenic action of a novel oxazole derivative through activation of AMPK pathway

Obesity is a chronic disorder with multifactorial etiology, including genetic, medical, dietary and other environmental factors. Both natural and synthetic heterocyclic compounds, especially oxazoles, represent an interesting group of compounds and have gained much attention due to their remarkable biological activities. Therefore, a library of 3,3-DMAH (3,3-dimethylallylhalfordinol) inspired N-alkylated oxazole bromide salts with varied substitutions were prepared and screened using the 3T3-L1 model of adipogenesis and HFD-induced obesity model in Syrian golden hamsters. Several compounds in the synthesized series displayed remarkable anti-adipogenic potential on the differentiation of 3T3-L1 preadipocytes. Compound 19e, displayed the most potent activity of all and selected for further studies. Compound 19e inhibited mitotic clonal expansion of 3T3-L1 cells and enhanced the mitochondrial oxygen consumption rate of the cells during early phase of differentiation via AMPK activation. 19e also improved the dyslipidaemia in high calorie diet fed Syrian Golden Hamsters. Therefore, compound 19e can serve as a potential lead against adipogenesis and dyslipidaemia models and could be further investigated to affirm its significance as a drug candidate.

Astragalus polysaccharide inhibits the development of urothelial carcinoma by activating AMPK signaling to induce BENC1-xCT complex formation

In recent years, the incidence of urothelial carcinoma (UC) has been high in men. The aim of this study was to investigate whether astragalus polysaccharide (APS) could inhibit the development of UC and the specific molecular mechanism. Our data showed that APS inhibited the proliferation of UC cells in a dose-dependent manner, and APS reduced the migratory capacity of RT4 and T24 cells. Further studies revealed that the ferroptosis inhibitor ferrostatin-1 (Fer-1) reversed APS-induced cell death, intracellular Fe2+ and malondialdehyde (MDA) accumulation, and lipid peroxidation product deposition. The Western blot and immunofluorescence results showed that APS significantly inhibited the expression of glutathione peroxidase 4 (GPX4) but did not alter the protein level of solute carrier family 7 member 11 (xCT, SLC7A11). Further analysis revealed that APS reduced the activity of xCT in RT4 and T24 cells. Moreover, APS significantly increased the phosphorylation levels of protein kinase AMP-activated catalytic subunit alpha 1 (AMPK) and BECN1 in RT4 and T24 cells, which induced the formation of the BECN1-xCT complex. However, when AMPK was silenced in RT4 and T24 cells, APS-induced ferroptosis was reversed to some extent, indicating that APS-mediated ferroptosis involves AMPK signaling. Moreover, APS has been shown to inhibit tumor growth in nude mice in vivo. In summary, our study demonstrated for the first time that APS could promote the formation of the BECN1-xCT complex in UC cells by activating AMPK/BECN1 signaling, which inhibited the activity of xCT to reduce GPX4 expression, thereby inducing ferroptosis and ultimately inhibiting UC progression.

Improving Mitochondrial Function in Skeletal Muscle Contributes to the Amelioration of Insulin Resistance by Nicotinamide Riboside

High-fat diet (HFD)-induced insulin resistance (IR) in skeletal muscle is often accompanied by mitochondrial dysfunction and oxidative stress. Boosting nicotinamide adenine dinucleotide (NAD) using nicotinamide riboside (NR) can effectively decrease oxidative stress and increase mitochondrial function. However, whether NR can ameliorate IR in skeletal muscle is still inconclusive. We fed male C57BL/6J mice with an HFD (60% fat) ± 400 mg/kg·bw NR for 24 weeks. C2C12 myotube cells were treated with 0.25 mM palmitic acid (PA) ± 0.5 mM NR for 24 h. Indicators for IR and mitochondrial dysfunction were analyzed. NR treatment alleviated IR in HFD-fed mice with regard to improved glucose tolerance and a remarkable decrease in the levels of fasting blood glucose, fasting insulin and HOMA-IR index. NR-treated HFD-fed mice also showed improved metabolic status regarding a significant reduction in body weight and lipid contents in serum and the liver. NR activated AMPK in the skeletal muscle of HFD-fed mice and PA-treated C2C12 myotube cells and upregulated the expression of mitochondria-related transcriptional factors and coactivators, thereby improving mitochondrial function and alleviating oxidative stress. Upon inhibiting AMPK using Compound C, NR lost its ability in enhancing mitochondrial function and protection against IR induced by PA. In summary, improving mitochondrial function through the activation of AMPK pathway in skeletal muscle may play an important role in the amelioration of IR using NR.

Moderately lipophilic 2-(Het)aryl-6-dithioacetals, 2-phenyl-1,4-benzodioxane-6-dithioacetals and 2-phenylbenzofuran-5-dithioacetals: Synthesis and primary evaluation as potential antidiabetic AMPK-activators

Since the 1950's, AMP-kinase (AMPK) has been used as a promising target for the development of antidiabetic drugs against Type 2 diabetes mellitus (T2D). Indeed, the canonical antidiabetic drug metformin recruits, at least partially, AMPK activation for its therapeutic effect. Herein we present design and synthesis of 20 novel relatively polar cyclic and acyclic dithioacetals of 2-(Het)arylchroman-6-carbaldehydes, 2-phenyl-1,4-benzodioxane-6-carbaldehyde, and 2-phenylbenzofuran-5-carbaldehyde, which were developed as potential AMPK activators. Three of the synthesized dithioacetals demonstrated significant enhancement (≥70%) of glucose uptake in rat L6 myotubes. Noteworthy, one of the dithioacetals, namely 4-(6-(1,3-dithian-2-yl)chroman-2-yl)pyridine, exhibited high potency comparing to other molecules. It increased the rate of glucose uptake in rat L6 myotubes and augmented insulin secretion from rat INS-1E cells in pharmacological relevant concentrations (up to 2 μM). Both effects were mediated by activation of AMPK. In addition, the compound showed excellent pharmacokinetic profile in healthy mice, including maximal oral bioavailability. Such bifunctionality (increased glucose uptake and insulin secretion) can be used as a starting point for the development of a novel class of antidiabetic drugs with dual activity that is relevant for T2D treatment.

Bryodulcosigenin attenuates bleomycin-induced pulmonary fibrosis via inhibiting AMPK-mediated mesenchymal epithelial transition and oxidative stress

Fibrosis is a pathological result of a dysfunctional repair response to tissue injury and occurs in several organs, including the lungs. Bryodulcosigenin (BDG) is a cucurbitane-type triterpene isolated from Siratia grosvenori and has clear-cut anti-inflammatory effects, yet its benefit of pulmonary fibrosis (PF) remains unclear. In this study, we investigated the protective effects of BDG (10 mg/kg/day, for 14 days) against TGF-β1-stimulated mouse alveolar epithelial MLE-12 cells and bleomycin (BLM)-induced PF mice. In vitro experiments showed that BDG could inhibit epithelial-mesenchymal transition (EMT) and oxidative stress. In vivo experiments indicated that BDG could ameliorate BLM-induced PF in mice as evidenced by characteristic structural changes in histopathology, increased collagen deposition and reduced survival and weight of mice. The abnormal increased expressions of TGF-β1, p-Smad2/3, α-SMA, COL-I, and NOX4 and decreased expressions for Sirt1 and p-AMPK were improved in BDG treatment. But these beneficial effects could be eliminated by co-treatment with Compound C (CC, a selective AMPK inhibitor). Molecular docking technology also revealed the potential of BDG to activate AMPK. In summary, AMPK activation modulated by BDG not only ameliorated TGF-β1/Smad2/3 signaling pathways but also partially mediated the suppression effects on EMT and oxidative stress, thus mediating the anti-fibrotic effects.

Biomimetic Nanocarriers Guide Extracellular ATP Homeostasis to Remodel Energy Metabolism for Activating Innate and Adaptive Immunity System

Metabolic interventions via targeting intratumoral dysregulated metabolism pathways have shown promise in reinvigorating antitumor immunity. However, approved small molecule immunomodulators often suffer from ineffective response rates and severe off-target toxicity. ATP occupies a crucial role in energy metabolism of components that form the tumor microenvironment (TME) and influences cancer immunosurveillance. Here, a nanocarrier-assisted immunometabolic therapy strategy that targets the ATP-adenosine axis for metabolic reprogramming of TME is reported. An ecto-enzyme (CD39) antagonist POM1 and AMP-activated protein kinase (AMPK) agonist metformin are both encapsulated into cancer cell-derived exosomes and used as nanocarriers for tumor targeting delivery. This method increases the level of pro-inflammatory extracellular ATP (eATP) while preventing the accumulation of immunosuppressive adenosine and alleviating hypoxia. Elevated eATP triggers the activation of P2X7-NLRP3-inflammasome to drive macrophage pyroptosis, potentiates the maturation and antigen capacity of dendritic cells (DCs) to enhance the cytotoxic function of T cells and natural killer (NK) cells. As a result, synergistic antitumor immune responses are initiated to suppress tumor progress, inhibit tumor distant metastases, provide long-term immune memory that offers protection against tumor recurrence and overcome anti-PD1 resistance. Overall, this study provides an innovative strategy to advance eATP-driven antitumor immunity in cancer therapy.

Protective effects of heterophyllin B against bleomycin-induced pulmonary fibrosis in mice via AMPK activation

Pulmonary fibrosis (PF) is a chronic interstitial lung disease with unknown etiology. In the present study, we evaluated the anti-fibrotic effects of heterophyllin B, a natural product from Radix Pseudostellariae having anti-inflammatory and tyrosinase inhibitory activities. In bleomycin (BLM)-induced PF mouse model, heterophyllin B treatments (5 or 20 mg/kg/d) significantly attenuated BLM-induced alveolar cavity collapse, inflammatory cell infiltration, alveolar wall thickening and collagen deposition. When compared to model group, heterophyllin B treatments also increased adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) phosphorylation levels by 359% (P < 0.001) and reduced the expression of stimulator of interferon genes (STING) by 73% (P < 0.001). Furthermore, co-administration of heterophyllin B with AMPK inhibitor dorsomorphin (Compound C) significantly blocked the improvement effects of heterophyllin B on BLM-damaged lung tissue, and also increased the protein expression of STING which was inhibited by heterophyllin B in fibrotic lungs (P < 0.001). It is known that alveolar epithelia and lung fibroblasts exert prominent roles in the fibrosis progression. In the present study we found that, in vitro, heterophyllin B significantly inhibited alveolar epithelial mesenchymal transition (EMT) and lung fibroblast transdifferentiation. We also found that the inhibition of heterophyllin B on lung fibroblast transdifferentiation and STING expression was reversed by Compound C. To summarize, heterophyllin B exhibited protective effects on BLM-induced lung fibrosis potentially by inhibiting TGF-Smad2/3 signalings and AMPK-mediated STING signalings.

Targeting Breast Cancer and Their Stem Cell Population through AMPK Activation: Novel Insights

Despite some significant advancements, breast cancer has become the most prevalent cancer in the world. One of the main reasons for failure in treatment and metastasis has been attributed to the presence of cancer initiating cells—cancer stem cells. Consequently, research is now being focussed on targeting cancer cells along with their stem cell population. Non-oncology drugs are gaining increasing attention for their potent anticancer activities. Metformin, a drug commonly used to treat type 2 diabetes, is the best example in this regard. It exerts its therapeutic action by activating 5′ adenosine monophosphate-activated protein kinase (AMPK). Activated AMPK subsequently phosphorylates and targets several cellular pathways involved in cell growth and proliferation and the maintenance of stem-like properties of cancer stem cells. Therefore, AMPK is emerging as a target of choice for developing effective anticancer drugs. Vanadium compounds are well-known PTP inhibitors and AMPK activators. They find extensive applications in treatment of diabetes and obesity via PTP1B inhibition and AMPK-mediated inhibition of adipogenesis. However, their role in targeting cancer stem cells has not been explored yet. This review is an attempt to establish the applications of insulin mimetic vanadium compounds for the treatment of breast cancer by AMPK activation and PTP1B inhibition pathways.

The effect of gallic acid on memory and anxiety-like behaviors in rats with bile duct ligation-induced hepatic encephalopathy: Role of AMPK pathway

OBJECTIVE

Hepatic encephalopathy (HE) is a serious neurological syndrome which is caused by acute and chronic liver diseases. In this study, the effect of gallic acid (GA) as an activator of AMP-activated protein kinase (AMPK) on memory and anxiety-like behaviors in rats with HE caused by bile duct ligation (BDL) was investigated.

MATERIALS AND METHODS

The rats were randomly divided into the following eight groups (n=7): sham; BDL; BDL+GA 20 mg/kg; BDL+GA 30 mg/kg; sham+dorsomorphin or compound C (CC) (as AMPK inhibitors); BDL+CC; BDL+GA 20 mg/kg+CC; and BDL+GA 30 mg/kg+CC. The rats received GA once daily by gavage for four weeks, and dorsomorphin 6.2 µg per rat was administered on a daily basis via bilateral intraventricular injection for four weeks. Behavioral tests including novel object recognition (NOR), open field and Morris water maze (MWM) were used to evaluate anxiety and memory in the rats.

RESULTS

Examining some parameters of NOR and MWM tests showed that memory performance was significantly reduced in the BDL versus the sham group, and in the BDL+CC versus the sham+CC group (p<0.05). GA intake improved memory in the GA-receiving groups compared with the BDL and BDL+CC groups (p<0.05). Examining some parameters of open field test showed that anxiety was significantly increased in the BDL versus the sham group, and the BDL+CC versus the sham+CC group (p<0.05). GA intake reduced anxiety in GA-receiving groups compared with the BDL+BDL+CC group (p<0.05).

CONCLUSION

GA was effective in improving cognitive and anxiety-like behaviors through activating AMPK.

Pharmacodynamic effects of direct AMP kinase activation in humans with insulin resistance and non-alcoholic fatty liver disease: A phase 1b study

AMPK is an energy sensor modulating metabolism, inflammation, and a target for metabolic disorders. Metabolic dysfunction results in lower AMPK activity. PXL770 is a direct AMPK activator, inhibiting de novo lipogenesis (DNL) and producing efficacy in preclinical models. We aimed to assess pharmacokinetics, safety, and pharmacodynamics of PXL770 in humans with metabolic syndrome-associated fatty liver disease. In a randomized, double-blind four-week trial, 12 overweight/obese patients with non-alcoholic fatty liver disease (NAFLD) and insulin resistance received PXL770 500 mg QD; 4 subjects received matching placebo. Endpoints included pharmacokinetics, hepatic fractional DNL, oral glucose tolerance testing, additional pharmacodynamic parameters, and safety. PK parameters show adequate plasma exposure in NAFLD patients for daily oral dosing. PXL770 decreases DNL—both peak and AUC are reduced versus baseline—and improves glycemic parameters and indices of insulin sensitivity versus baseline. Assessment of specific lipids reveals decrease in diacyglycerols/triacylglycerols. Safety/tolerability are similar to placebo. These results unveil initial human translation of AMPK activation and support this therapeutic strategy for metabolic disorders.

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AMPK is impaired in metabolic diseases—PXL770 is a direct AMPK activator

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In humans with NAFLD, PXL770 inhibits hepatic de novo lipogenesis (target engagement)

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PXL770 also improves glucose tolerance and insulin sensitivity

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PXL770 reduces plasma levels of di- and triglycerides

Effects of valerate on intestinal barrier function in cultured Caco-2 epithelial cell monolayers

BACKGROUND

Short-chain fatty acids (SCFAs) are a group of microbial metabolites of undigested dietary fiber, protein and unabsorbed amino acids in the colon, well-known for their gut health promoting benefits. A relatively high intestinal level of valerate was found in the healthy human subjects. However, the intestinal protection effects and the underlying mechanism of valerate are waiting to be verified and elucidated.

METHODS AND RESULTS

In the present study, valerate, a SCFAs mainly converted from proteins or amino acids, was demonstrated to promote intestinal barrier function at its physiological concentrations of 0-4 mM in the Caco-2 cell monolayer model of intestinal barrier using transepithelial electrical resistance (TEER) assay and paracellular permeability assay. Valerate achieved the maximum increase in the TEER at 2 mM and reduced the paracellular permeability. Its intestinal barrier function promoting activity is similar to that of butyrate, with a broader range of effective concentrations than the later. Through western blot analysis, this activity is linked to the valerate-induced AMPK activation and tight junctions (TJs) assembly, but not to the reinforced expression of TJs related proteins.

CONCLUSIONS

It provides direct experimental evidence supporting valerate's function in intestinal health, implying the once under-valued function of valerate and its amino acid precursors. The valerate's role in regulating intestine homeostasis and its possible synergetic effects with other SCFAs warranted to be further investigated.

Fluorinated thiazolidinol drives autophagic cell death in pancreatic cancer cells via AMPK activation and perturbation of critical sentinels of oncogenic signaling

Pancreatic cancer is one of the most malignant cancers around the world. The co-occurrence of mutation in KRAS and p53 makes it highly aggressive, proliferative, metastatic, and resistant to apoptotic cell death. Therefore, there is a need to trigger an alternate mechanism of cancer cell death in apoptosis-resistant pancreatic cancer. Autophagic cell death could be an alternate viable option for treatment in such cases. Thus, the identification of small molecules as autophagy modulators with potent anticancer efficacy would be of great importance in pancreatic cancer. The present study investigates fluorinated thiazolidionol (FTZ) driven autophagy modulation, underlying mechanism, and regulation of critical sentinels of oncogenic signaling in pancreatic cancer cells. We identified that FTZ triggered autophagic cell death in pancreatic cancer cells, independent of apoptosis evidenced by an increase in cytoplasmic vacuoles formation, autophagy flux, LC3-II expression, and p62 degradation. Further, the crucial events of apoptosis i.e., Caspase-3 activation and PARP cleavage, were not observed, indicating the non-occurrence of apoptotic cell death. Moreover, FTZ was able to activate AMPK and suppress PI3k/Akt/mTOR as well as MEK/ERK, the key oncogenic signaling pathways in cancer cells. Furthermore, treatment with FTZ suppressed migration, invasion, and angiogenesis in pancreatic cancer cells. Studies in vivo revealed significant regression of tumors by FTZ in nude mice model. Overall, our study demonstrates that FTZ induces autophagic cell death in pancreatic cancer cells independent of apoptosis, which is accompanied by AMPK activation and suppression of critical sentinels of oncogenic signaling in pancreatic cancer cells.

Pyrvinium Treatment Confers Hepatic Metabolic Benefits via β-Catenin Downregulation and AMPK Activation

Genetic evidence has indicated that β-catenin plays a vital role in glucose and lipid metabolism. Here, we investigated whether pyrvinium, an anthelmintic agent previously reported as a down-regulator of cellular β-catenin levels, conferred any metabolic advantages in treatment of metabolic disorders. Glucose production and lipid accumulation were analyzed to assess metabolic response to pyrvinium in hepatocytes. The expression of key proteins and genes were assessed by immunoblotting and RT-PCR. The in vivo efficacy of pyrvinium against metabolic disorders was evaluated in the mice fed with a high fat diet (HFD). We found that pyrvinium inhibited glucose production and reduced lipogenesis by decreasing the expression of key genes in hepatocytes, which were partially elicited by the downregulation of β-catenin through AXIN stabilization. Interestingly, the AMPK pathway also played a role in the action of pyrvinium, dependent on AXIN stabilization but independent of β-catenin downregulation. In HFD-fed mice, pyrvinium treatment led to improvement in glucose tolerance, fatty liver disorder, and serum cholesterol levels along with a reduced body weight gain. Our results show that small molecule stabilization of AXIN using pyrvinium may lead to improved glucose and lipid metabolism, via β-catenin downregulation and AMPK activation.

Role of the CTRP6/AMPK pathway in kidney fibrosis through the promotion of fatty acid oxidation

CTRP6, a newly identified adiponectin analogue, has been shown to be involved in inflammation, diabetes and cardiovascular diseases. Recently, increasing evidence has shown that CTRP6 plays a critical role in fibrotic diseases, such as myocardial fibrosis and skin fibrosis. FAO, an important energy source for kidney proximal tubular cells, also participates in the process of fibrosis. Therefore, our study aimed to investigate the effect of CTRP6 on mediating FAO in kidney fibrosis and the underlying associated mechanism. Firstly, the activity of CTRP6 and the key enzymes of FAO (CPT1A, ACOX1) were tested in vivo and vitro. Next, the regulatory effect of CTRP6/AMPK on FAO was accessed in animal models and in cell lines. Additionally, we explored the effect of exogenous recombinant CTRP6 on renal tubular epithelial cell differentiation. Decreased CTRP6 and p-AMPK were detected in UUO-induced kidney fibrosis and in TGF-β1-treated HK-2 cells. We also observed that defective FAO occurred during kidney fibrosis. Moreover, the human CTRP6 peptide could inhibit the ECM deposition and promote the phosphorylation of AMPK by promoting FAO. However, the inhibitory effects of CTRP6 on TGF-β1-induced ECM deposition and the protective effects of CTRP6 on FAO could be abolished by compound C, a selective inhibitor of AMPK. Compound C also reversed the CTRP6-mediated upregulation of p-AMPK. The mediation of FAO by CTRP6 plays a key role in kidney fibrosis by regulating TGF-β1-induced renal tubular epithelial cell differentiation by promoting FAO, which is mediated via AMPK activation.

Metformin: A Prospective Alternative for the Treatment of Chronic Pain

Metformin (biguanide) is a drug widely used for the treatment of type 2 diabetes. This drug has been used for 60 years as a highly effective antihyperglycemic agent. The search for the mechanism of action of metformin has produced an enormous amount of research to explain its effects on gluconeogenesis, protein metabolism, fatty acid oxidation, oxidative stress, glucose uptake, autophagy and pain, among others. It was only up the end of the 1990s and beginning of this century that some of its mechanisms were revealed. Metformin induces its beneficial effects in diabetes through the activation of a master switch kinase named AMP-activated protein kinase (AMPK). Two upstream kinases account for the physiological activation of AMPK: liver kinase B1 and calcium/calmodulin-dependent protein kinase kinase 2. Once activated, AMPK inhibits the mechanistic target of rapamycin complex 1 (mTORC1), which in turn avoids the phosphorylation of p70 ribosomal protein S6 kinase 1 and phosphatidylinositol 3-kinase/protein kinase B signaling pathways and reduces cap-dependent translation initiation. Since metformin is a disease-modifying drug in type 2 diabetes, which reduces the mTORC1 signaling to induce its effects on neuronal plasticity, it was proposed that these mechanisms could also explain the antinociceptive effect of this drug in several models of chronic pain. These studies have highlighted the efficacy of this drug in chronic pain, such as that from neuropathy, insulin resistance, diabetic neuropathy, and fibromyalgia-type pain. Mounting evidence indicates that chronic pain may induce anxiety, depression and cognitive impairment in rodents and humans. Interestingly, metformin is able to reverse some of these consequences of pathological pain in rodents. The purpose of this review was to analyze the current evidence about the effects of metformin in chronic pain and three of its comorbidities (anxiety, depression and cognitive impairment).

Energy expenditure during cell spreading influences the cellular response to matrix stiffness

Cells respond to the mechanical properties of the extracellular matrix (ECM) through formation of focal adhesions (FAs), re-organization of the actin cytoskeleton and adjustment of cell contractility. These are energy-demanding processes, but a potential causality between mechanical cues (matrix stiffness) and cellular (energy) metabolism remains largely unexplored. Here, we cultured human mesenchymal stem cells (hMSCs) on stiff (20 kPa) or soft (1 kPa) substrate and demonstrate that cytoskeletal reorganization and FA formation spreading on stiff substrates lead to a drop in intracellular ATP levels, correlating with activation of AMP-activated protein kinase (AMPK). The resulting increase in ATP levels further facilitates cell spreading and reinforces cell tension of the steady state, and coincides with nuclear localization of YAP/TAZ and Runx2. While on soft substrates (1 kPa), lowered ATP levels limit these cellular mechanoresponses. Furthermore, genetic ablation of AMPK lowered cellular ATP levels on stiff substrate and strongly reduced responses to substrate stiffness. Together, these findings reveal a hitherto unidentified relationship between energy expenditure and the cellular mechanoresponse, and point to AMPK as a key mediator of stem cell fate in response to ECM mechanics.

Discovery of a promising agent IQZ23 for the treatment of obesity and related metabolic disorders

Discovery of novel anti-obesity agents is a challenging and promising research area. Based on our previous works, we synthesized 40 novel β-indoloquinazoline analogues by altering the skeleton and introducing preferential side chains, evaluated their lipid-lowering activity and summarized the structure-activity relationships. In combination with an evaluation of the lipid-lowering efficacies, AMP-dependent activated protein kinase (AMPK) activating ability and liver microsomal stability, compound 23 (named as IQZ23) was selected for further studies. IQZ23 exerted a high efficacy in decreasing the triglyceride level (EC₅₀ = 0.033 μM) in 3T3-L1 adipocytes. Mechanistic studies revealed the lipid-lowering activity of IQZ23 was dependent on the AMPK pathway by modulating ATP synthase activity. This activation was accompanied by mitochondrial biogenesis and oxidation capacity increased, and insulin sensitivity enhanced in pertinent cell models by various interventions. Correspondingly, IQZ23 (20 mg/kg, i.p.) treatment significantly reversed high fat and cholesterol diet (HFC)- induced body weight increases and accompanying clinical symptoms of obesity in mice but without indicative toxicity. These results indicate that IQZ23 could be a useful candidate for the treatment of obesity and related metabolic disorders.

Astaxanthin stimulates mitochondrial biogenesis in insulin resistant muscle via activation of AMPK pathway

BACKGROUND

Skeletal muscle is mainly responsible for insulin-stimulated glucose disposal. Dysfunction in skeletal muscle metabolism especially during obesity contributes to the insulin resistance. Astaxanthin (AX), a natural antioxidant, has been shown to ameliorate hepatic insulin resistance in obese mice. However, its effects in skeletal muscle are poorly understood. The current study aimed to investigate the molecular target of AX in ameliorating skeletal muscle insulin resistance.

METHODS

We fed 6-week-old male C57BL/6J mice with normal chow (NC) or NC supplemented with AX (NC+AX) and high-fat-diet (HFD) or HFD supplemented with AX for 24 weeks. We determined the effect of AX on various parameters including insulin sensitivity, glucose uptake, inflammation, kinase signaling, gene expression, and mitochondrial function in muscle. We also determined energy metabolism in intact C2C12 cells treated with AX using the Seahorse XFe96 Extracellular Flux Analyzer and assessed the effect of AX on mitochondrial oxidative phosphorylation and mitochondrial biogenesis.

RESULTS

AX-treated HFD mice showed improved metabolic status with significant reduction in blood glucose, serum total triglycerides, and cholesterol (p< 0.05). AX-treated HFD mice also showed improved glucose metabolism by enhancing glucose incorporation into peripheral target tissues, such as the skeletal muscle, rather than by suppressing gluconeogenesis in the liver as shown by hyperinsulinemic-euglycemic clamp study. AX activated AMPK in the skeletal muscle of the HFD mice and upregulated the expressions of transcriptional factors and coactivator, thereby inducing mitochondrial remodeling, including increased mitochondrial oxidative phosphorylation component and free fatty acid metabolism. We also assessed the effects of AX on mitochondrial biogenesis in the siRNA-mediated AMPK-depleted C2C12 cells and showed that the effect of AX was lost in the genetically AMPK-depleted C2C12 cells. Collectively, AX treatment (i) significantly ameliorated insulin resistance and glucose intolerance through regulation of AMPK activation in the muscle, (ii) stimulated mitochondrial biogenesis in the muscle, (iii) enhanced exercise tolerance and exercise-induced fatty acid metabolism, and (iv) exerted antiinflammatory effects via its antioxidant activity in adipose tissue.

CONCLUSIONS

We concluded that AX treatment stimulated mitochondrial biogenesis and significantly ameliorated insulin resistance through activation of AMPK pathway in the skeletal muscle.

Alpha-Mangostin Ameliorates Bleomycin-Induced Pulmonary Fibrosis in Mice Partly Through Activating Adenosine 5'-Monophosphate-Activated Protein Kinase

Background: Pulmonary fibrosis (PF) is a devastating interstitial lung disease and characterized by an abnormal accumulation of extracellular matrix (ECM). Nintedanib (NDN) and pirfenidone are two approved therapies for PF, but their potential side-effects have been reported. Recently, the use of natural supplements for PF is attracting attention. Alpha-mangostin (α-MG) is an active xanthone-type compound isolated from the nutritious fruit mangosteen.

Purpose: In the present study, the potential effect and underlying mechanism of α-MG were evaluated in bleomycin (BLM)-induced PF and activated primary lung fibroblasts (PLFs).

Methods: Histopathological changes and collagen deposition were analyzed via hematoxylin-eosin staining and Masson staining, the expression of nicotinamide adenine dinucleotide phosphate oxidase-4 (NOX4) involved in oxidative stress in lung tissues was analyzed by immunochemistry staining. The expressions of α-smooth muscle actin (α-SMA), collagen I (Col I), p-adenosine 5′-monophosphate-activated protein kinase (AMPK)/AMPK, and NOX4 were detected by Western blot, immunofluorescence or RT-PCR, and effects of α-MG on cell viability were detected using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide.

Results:In vivo results demonstrated that α-MG treatment (10 mg/kg/day) significantly ameliorated BLM-induced deposition of ECM in lung tissues. Moreover, α-MG could inhibit protein expressions of α-SMA and Col I as well as its mRNA levels. In addition, α-MG also significantly inhibited transforming growth factor-β1/Smad2/3 pathway and regulated the protein expression of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in lung tissues. In vitro results demonstrated that α-MG significantly increased p-AMPK/AMPK but reduced the protein expression level of α-SMA and Col I as well as NOX4 in activated PLFs. Further study demonstrated that these improvement effects were significantly blocked by compound C.

Conclusion: α-MG treatment significantly decreased oxidative stress in lungs partly by activating AMPK mediated signaling pathway in BLM-induced PF and activated PLFs and decreased the deposition of ECM. The present study provides pharmacological evidence to support therapeutic application of α-MG in the treatment of PF.

Metformin-Encapsulated Liposome Delivery System: An Effective Treatment Approach against Breast Cancer

This study aimed at developing metformin hydrochloride (Met) encapsulated liposomal vesicles for enhanced therapeutic outcomes at reduced doses against breast cancer. Liposomal Met was prepared using thin-film hydration through various loading methods; passive loading, active loading, and drug-loaded lipid film. The drug-loaded film method exhibited maximum entrapment efficiency (~65%) as compared to active loading (~25%) and passive loading (~5%) prepared Met-loaded liposomes. The therapeutic efficacy of these optimized liposomes was evaluated for cellular uptake, cytotoxicity, inhibition of metastatic activity, and apoptosis-inducing activity. Results demonstrated significantly superior activity of positively charged liposomes resulting in reduced IC₅₀ values, minimal cell migration activity, reduced colony formation, and profound apoptosis-induced activity in breast cancer cells as compared to Met. The anti-tumor activity was investigated using a clinically relevant in vitro tumor simulation model, which confirmed enhanced anti-tumorigenic property of liposomal Met over Met itself. To the authors’ knowledge, this is the first report of Met-loaded liposomes for improving the efficacy and therapeutic effect of Met against breast cancer. With the results obtained, it can be speculated that liposomal encapsulation of metformin offers a potentially promising and convenient approach for enhanced efficacy and bioavailability in breast cancer treatment.

Mitochondrial dysfunction, AMPK activation and peroxisomal metabolism: A coherent scenario for non-canonical 3-methylglutaconic acidurias

The occurrence of 3-methylglutaconic aciduria (3-MGA) is a well understood phenomenon in leucine oxidation and ketogenesis disorders (primary 3-MGAs). In contrast, its genesis in non-canonical (secondary) 3-MGAs, a growing-up group of disorders encompassing more than a dozen of inherited metabolic diseases, is a mystery still remaining unresolved for three decades. To puzzle out this anthologic problem of metabolism, three clues were considered: (i) the variety of disorders suggests a common cellular target at the cross-road of metabolic and signaling pathways, (ii) the response to leucine loading test only discriminative for primary but not secondary 3-MGAs suggests these latter are disorders of extramitochondrial HMG-CoA metabolism as also attested by their failure to increase 3-hydroxyisovalerate, a mitochondrial metabolite accumulating only in primary 3-MGAs, (iii) the peroxisome is an extramitochondrial site possessing its own pool and displaying metabolism of HMG-CoA, suggesting its possible involvement in producing extramitochondrial 3-methylglutaconate (3-MG). Following these clues provides a unifying common basis to non-canonical 3-MGAs: constitutive mitochondrial dysfunction induces AMPK activation which, by inhibiting early steps in cholesterol and fatty acid syntheses, pipelines cytoplasmic acetyl-CoA to peroxisomes where a rise in HMG-CoA followed by local dehydration and hydrolysis may lead to 3-MGA yield. Additional contributors are considered, notably for 3-MGAs associated with hyperammonemia, and to a lesser extent in CLPB deficiency. Metabolic and signaling itineraries followed by the proposed scenario are essentially sketched, being provided with compelling evidence from the literature coming in their support.

Galactomannan Pentasaccharide Produced from Copra Meal Enhances Tight Junction Integration of Epithelial Tissue through Activation of AMPK

Mannan oligosaccharide (MOS) is well-known as an effective fed supplement for livestock to increase their nutrients absorption and health status. Pentasaccharide of mannan (MOS5) was reported as a molecule that possesses the ability to increase tight junction of epithelial tissue, but the structure and mechanism of action remains undetermined. In this study, the mechanism of action and structure of MOS5 were investigated. T84 cells were cultured and treated with MOS5 compared with vehicle and compound C, a 5′-adenosine monophosphate-activated protein kinase (AMPK) inhibitor. The results demonstrated that the ability of MOS5 to increase tight junction integration was inhibited in the presence of dorsomorphine (compound C). Phosphorylation level of AMPK was elevated in MOS5 treated group as determined by Western blot analysis. Determination of MOS5 structure was performed using enzymatic mapping together with ¹H, ¹³C NMR, and 2D-NMR analysis. The results demonstrated that the structure of MOS5 is a β-(1,4)-mannotetraose with α-(1,6)-galactose attached at the second mannose unit from non-reducing end.

Metformin ameliorates endotoxemia-induced endothelial pro-inflammatory responses via AMPK-dependent mediation of HDAC5 and KLF2

Exaggerated endothelial pro-inflammatory response is a hallmark in the early stage of sepsis and contributes to the subsequent tissue injury and organ failure. The anti-inflammatory effects of AMP-activated protein kinase (AMPK) activator metformin in sepsis has been revealed. However, the underlying mechanisms remain not fully understood. In the present study, the potential roles of histone deacetylase 5 (HDAC5) and kruppel-like factor 2 (KLF2) in the effects of metformin on endothelial pro-inflammatory responses were investigated. The results showed that metformin pretreatment increased the phosphorylation of HDAC5 at serine 498, leading to the upregulation of KLF2, and eliminated lipopolysaccharide (LPS) and tumor necrosis factor ⍺ (TNF⍺)-induced upregulation of vascular cell adhesion molecule 1 (VCAM1). Furthermore, the adhesion of HL60 leukocytes to endothelial monolayer was effectively inhibited by metformin. In addition, the in vivo data confirmed that AMPK activation attenuated local and systemic inflammation in endotoxic mice induced by LPS via mediating phosphorylating HDAC5 and restoring KLF2 expression. Our findings revealed that AMPK activation-mediated HDAC5 phosphorylation and KLF2 restoration is, at least partially, responsible to the anti-inflammatory effects of metformin in endotoxemia-induced endothelial cells, which has important implications for the future development of interfering therapies of sepsis.

Milk From Cow Fed With High Forage/Concentrate Ratio Diet: Beneficial Effect on Rat Skeletal Muscle Inflammatory State and Oxidative Stress Through Modulation of Mitochondrial Functions and AMPK Activity

Milk and dairy products are relevant components of daily diet and are part of dietary recommendation in many countries due to their content of key nutrients. However, the relatively high content of saturated fat of the milk and its extensive usage for every age group raises concerns about its potential negative health effects. Therefore, in the last years, several researchers dedicated their attention to milk production and quality. Milk fatty acids profile depend on cow feeding and in particular on the type of forage and concentrate and forage/concentrate ratio. It was demonstrated that feeding dairy cows with a 70/30 forage/concentrate ratio yields milk with a low ω6:ω3 ratio and high CLA levels. In this work, we demonstrated that the supplementation of rats diet with this high forage milk (HFM) results, in the skeletal muscle of these animals, in a reduced lipid content and inflammation levels, and an improved mitochondrial lipid oxidation, and redox status through modulation of AMPK activity.

The isomiR-140-3p-regulated mevalonic acid pathway as a potential target for prevention of triple negative breast cancer

BACKGROUND

Prevention of triple-negative breast cancer (TNBC) is hampered by lack of knowledge about the drivers of tumorigenesis.

METHODS

To identify molecular markers and their downstream networks that can potentially be targeted for TNBC prevention, we analyzed small RNA and RNA sequencing of a cell line model that represent early stages of TNBC development. We have identified direct gene targets of isomiRNA-140-3p and by using cell-based and in vivo model systems we have demonstrated the utility of targeting downstream pathways for prevention of TNBC.

RESULTS

These analyses showed that 5'isomiRNA of miR-140-3p (miR-140-3p-1) and its novel direct gene targets, HMG-CoA reductase (HMGCR) and HMG-CoA synthase 1(HMGCS1), key enzymes in the cholesterol biosynthesis pathway, were deregulated in the normal-to-preneoplastic transition. Upregulation in the cholesterol pathway creates metabolic vulnerability that can be targeted. Consistent with this hypothesis, we found direct targeting of miR-140-3p-1 and its downstream pathway by fluvastatin to inhibit growth of these preneoplastic MCF10.AT1 cells. However, although, fluvastatin inhibited the growth of MCF10.AT1-derived xenografts, histological progression remained unchanged. The cholesterol pathway is highly regulated, and HMGCR enzymatic activity inhibition is known to trigger a feedback response leading to restoration of the pathway. Indeed, we found fluvastatin-induced HMGCR transcript levels to be directly correlated with the degree of histological progression of lesions, indicating that the extent of cholesterol pathway suppression directly correlates with abrogation of the tumorigenic process. To block the HMGCR feedback response to statins, we treated resistant preneoplastic cells with an activator of AMP-activated protein kinase (AMPK), a brake in the cholesterol feedback pathway. AMPK activation by aspirin and metformin effectively abrogated the statin-induced aberrant upregulation of HMGCR and sensitized these resistant cells to fluvastatin.

CONCLUSIONS

These results suggest the potential use of combined treatment with statin and aspirin for prevention of TNBC.

Chicory (Cichorium intybus L.) polysaccharides attenuate high-fat diet induced non-alcoholic fatty liver disease via AMPK activation

Chicory polysaccharides (CP) from Cichorium intybus L. roots were extracted and fractionated to isolate two novel polysaccharide fractions, CP-1 and CP-2. CP-1 is a heteropolysaccharide that is mainly composed of sorbin, glucose, fructose, and glucitol at a molar ratio of 1.00:5.58:13.97:10.32. The molecular weight of CP-1 was 8511.4 Da. The hepatoprotective effect of CP-1 was investigated in a rat model of high-fat diet induced non-alcoholic fatty liver disease (NAFLD) rats. Results indicated that the oral administration of CP-1 significantly decreased body weight and liver index in NAFLD rats. CP-1 also significantly increased serum levels of SOD and HDLC, and decreased the levels of ALT, AST, TG, TC, LDL-C, GLU, ALP, LDH, and MDA in NAFLD rats. Meanwhile, CP-1 effectively decreased MDA, TC, and TG, and increased SOD and T-AOC in the livers of NAFLD rats. Furthermore, CP-1 also increased the hepatic expression of p-AMPKα, ATGL, CPT-1, and p-ACC, and reduced the hepatic expression of ACC, FAS, and SCD-1. Moreover, histopathological examination of the livers showed that CP-1 significantly ameliorated the symptoms of NAFLD rats. Therefore, CP-1 significantly attenuated the high-fat diet-induced NAFLD in rats via AMPK activation.

Eupatilin ameliorates dextran sulphate sodium-induced colitis in mice partly through promoting AMPK activation

BACKGROUND

Despite the higher morbidity of ulcerative colitis (UC), available treatments remain unsatisfactory in recent years. A natural flavone eupatilin (Eup) is known to inhibit the intestinal contraction.

PURPOSE

The protective role of Eup in intestinal inflammation remains unclear. This study attempted to determine the bioactivity of Eup against colitis and clarify the mechanism of action.

STUDY DESIGN

The in vitro effects of Eup on lipopolysaccharide-induced human THP-M macrophage activation and tumour necrosis factor-α (TNF-α)-damaged intestinal epithelial (NCM460) cells were explored to clarify its potential protective effects. Then, the alleviative efficacy of Eup was established in dextran sodium sulphate (DSS)-induced mice colitis.

METHODS

Pathological diagnosis, immunohistochemical staining, and reverse transcriptase PCR analysis as well as western blot analysis were employed in the current study.

RESULTS

Eup clearly inhibited inflammatory responses in LPS-stimulated macrophages. Eup also clearly stabilized colonic epithelia by down-regulating overexpression of tight junction proteins and NADPH oxidases 4 (NOX4), and by promoting AMP-activated protein kinase (AMPK) activation in TNF-α-stimulated NCM460 cells. In addition, in vivo study demonstrated that Eup treatment clearly ameliorated the symptoms and pathologic changes of colitis mice. The therapeutic effect of Eup was found to be reduced when compound C (an AMPK pharmacological inhibitor) was given to mice.

CONCLUSION

The study successfully demonstrated that Eup ameliorated DSS-induced mice colitis by suppressing inflammation and maintaining the integrity of the intestinal epithelial barrier via AMPK activation. The results provide valuable guidance for using Eup in UC treatment.

Long Feeding High-Fat Diet Induces Hypothalamic Oxidative Stress and Inflammation, and Prolonged Hypothalamic AMPK Activation in Rat Animal Model

Scope: The hypothalamus is a key brain region involved in the control of feeding and energy expenditure. Hypothalamic inflammation and oxidative stress are landmarks of both obesity and aging processes, although the molecular mechanisms are still unknown. Therefore, with the aim to understand the neurobiological mechanisms of energy homeostasis during aging, we evaluate the effects of long feeding high-fat diet (HFD) in rats, at different age, on modulation of hypothalamic molecular pathway, oxidative stress, and inflammation.

Procedures: Male Wistar rats were divided into two groups: control group, receiving standard diet (CD), and treated group, receiving HFD. Both groups were treated with the appropriate diet for 1, 3, 6, 12, or 18 weeks. We investigated energy balance and body composition, as well as lipid profile, homeostatic model assessment index, and inflammatory state in serum. Furthermore, we also analyzed, at hypothalamic level, inflammation and oxidative stress, and adenosine monophosphate-dependent kinase (AMPK) and pAMPK expression levels.

Results: Our data showed that aging and HFD induce increased energy intake and energy efficiency and decreased energy expenditure associated, at hypothalamic level, with inflammation and oxidative stress and activation of AMPK.

Conclusion: Our results indicate that the age at which HFD feeding starts and the diet duration are critical in obesity development. The prolonged activation of hypothalamic AMPK may be related to the alterations in energy homeostasis.

Metformin + Sodium-glucose Co-transporter-2 Inhibitor: Salutogenic Lifestyle Mimetics in a Tablet?

Salutogenesis is an accepted approach for chronic disease management. Calorie restriction and exercise are two evidence based salutogenic interventions in diabetes treatment. Calorie restriction mimetics and exercise mimetics may be used as pharmacological tools to help manage diabetes in a sulutogenic manner. This article discusses the biochemical basis and pharmacology of metformin and sodium glucose cotransporter 2 inhibitors. It describes how a combination of these drugs can be used as a calories restriction and exercise mimetic, to help improve diabetes control.

Strawberry consumption improves aging-associated impairments, mitochondrial biogenesis and functionality through the AMP-activated protein kinase signaling cascade

Dietary polyphenols have been recently proposed as activators of the AMP-activated protein kinase (AMPK) signaling pathway and this fact might explain the relationship between the consumption of polyphenol-rich foods and the slowdown of the progression of aging. In the present work, the effects of strawberry consumption were evaluated on biomarkers of oxidative damage and on aging-associated reductions in mitochondrial function and biogenesis for 8weeks in old rats. Strawberry supplementation increased antioxidant enzyme activities, mitochondrial biomass and functionality, and decreased intracellular ROS levels and biomarkers of protein, lipid and DNA damage (P<0.05). Furthermore, a significant (P<0.05) increase in the expression of the AMPK cascade genes, involved in mitochondrial biogenesis and antioxidant defences, was also detected after strawberry intake. These in vivo results were then verified in vitro on HepG2 cells, confirming the involvement of AMPK in the beneficial effects exerted by strawberry against aging progression.

Methylisoindigo preferentially kills cancer stem cells by interfering cell metabolism via inhibition of LKB1 and activation of AMPK in PDACs

Pancreatic ductal adenocarcinoma (PDAC) clinically has a very poor prognosis. No small molecule is available to reliably achieve cures. Meisoindigo is chemically related to the natural product indirubin and showed substantial efficiency in clinical chemotherapy for CML in China. However, its effect on PDAC is still unknown. Our results showed strong anti-proliferation effect of meisoindigo on gemcitabine-resistant PDACs. Using a recently established primary PDAC cell line, called Jopaca-1 with a larger CSCs population as model, we observed a reduction of CD133+ and ESA+/CD44+/CD24+ populations upon treatment and concomitantly a decreased expression of CSC-associated genes, and reduced cellular mobility and sphere formation. Investigating basic cellular metabolic responses, we detected lower oxygen consumption and glucose uptake, while intracellular ROS levels increased. This was effectively neutralized by the addition of antioxidants, indicating an essential role of the cellular redox balance. Further analysis on energy metabolism related signaling revealed that meisoindigo inhibited LKB1, but activated AMPK. Both of them were involved in cellular apoptosis. Additional in situ hybridization in tissue sections of PDAC patients reproducibly demonstrated co-expression and -localization of LKB1 and CD133 in malignant areas. Finally, we detected that CD133+/CD44+ were more vulnerable to meisoindigo, which could be mimicked by LKB1 siRNAs. Our results provide the first evidence, to our knowledge, that LKB1 sustains the CSC population in PDACs and demonstrate a clear benefit of meisoindigo in treatment of gemcitabine-resistant cells. This novel mechanism may provide a promising new treatment option for PDAC.