• IMMUNE NETWORK
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• v.11 no.2
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• pp.107-113
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• 2011

Background: Metabolic disorders, including type II diabetes and obesity, present major health risks in industrialized countries. AMP-activated protein kinase (AMPK) has become the focus of a great deal of attention as a novel therapeutic target for the treatment of metabolic syndromes. In this study, we evaluated whether dietary aloe could reduce obesity-induced inflammation and adipogenesis. Methods: Male C57BL/6 obese mice fed a high-fat diet for 54 days received a supplement of aloe formula (PAG, ALS, Aloe QDM, and Aloe QDM complex) or pioglitazone (PGZ) and were compared with unsupplemented controls (high-fat diet; HFD) or mice fed a regular diet (RD). RT-PCR and western blot analysis were used to quantify the expression of obesity-induced inflammation. Results: Aloe QDM complex downregulated fat size through suppressed expression of scavenger receptors on adipose tissue macrophages (ATMs) compared with HFD. Both white adipose tissue (WATs) and muscle exhibited increased AMPK activation through aloe supplementation, and in particular, the Aloe QDM complex. Obesity-induced inflammatory cytokines (IL-$1{\beta}$ and -6) and $HIF1{\alpha}$ mRNA and protein were decreased markedly, as was macrophage infiltration by the Aloe QDM complex. Further, the Aloe QDM complex decreased the translocation of NF-${\kappa}B$ p65 from the cytosol in the WAT. Conclusion: Dietary aloe formula reduced obesity-induced inflammatory responses by activation of AMPK in muscle and suppression of proinflammatory cytokines in the WAT. Additionally, the expression of scavenger receptors in the ATM and activation of AMPK in WAT led to reduction in the percent of body fat. Thus, we suggest that the effect of the Aloe QDM complex in the WAT and muscle are related to activation of AMPK and its use as a nutritional intervention against T2D and obesity-related inflammation.

• Biomolecules & Therapeutics
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• v.29 no.6
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• pp.650-657
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• 2021

Metformin is an anti-diabetic drug and has anticancer effects on various cancers. Several studies have suggested that metformin reduces cell proliferation and stimulates cell-cycle arrest and apoptosis. However, the definitive molecular mechanism of metformin in the pathophysiological signaling in endometrial tumorigenesis and metastasis is not clearly understood. In this study, we examined the effects of metformin on the cell viability and apoptosis of human cervical HeLa and endometrial HEC-1-A and KLE cancer cells. Metformin suppressed cell growth in a dose-dependent manner and dramatically evoked apoptosis in HeLa cervical cancer cells, while apoptotic cell death and growth inhibition were not observed in endometrial (HEC-1-A, KLE) cell lines. Accordingly, the p27 and p21 promoter activities were enhanced while Bcl-2 and IL-6 activities were significantly reduced by metformin treatment. Metformin diminished the phosphorylation of mTOR, p70S6K and 4E-BP1 by accelerating adenosine monophosphate-activated kinase (AMPK) in HeLa cancer cells, but it did not affect other cell lines. To determine why the anti-proliferative effects are observed only in HeLa cells, we examined the expression level of liver kinase B1 (LKB1) since metformin and LKB1 share the same signalling system, and we found that the LKB1 gene is not expressed only in HeLa cancer cells. Consistently, the overexpression of LKB1 in HeLa cancer cells prevented metformin-triggered apoptosis while LKB1 knockdown significantly increased apoptosis in HEC-1-A and KLE cancer cells. Taken together, these findings indicate an underlying biological/physiological molecular function specifically for metformin-triggered apoptosis dependent on the presence of the LKB1 gene in tumorigenesis.

• Development and Reproduction
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• v.27 no.2
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• pp.77-89
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• 2023

Metformin is the most widely used anti-diabetic drug that helps maintain normal blood glucose levels primarily by suppressing hepatic gluconeogenesis in type II diabetic patients. We previously found that metformin induces apoptotic death in H4IIE rat hepatocellular carcinoma cells. Despite its anti-diabetic roles, the effect of metformin on hepatic de novo lipogenesis (DNL) remains unclear. We investigated the effect of metformin on hepatic DNL and apoptotic cell death in H4IIE cells. Metformin treatment stimulated glucose consumption, lactate production, intracellular fat accumulation, and the expressions of lipogenic proteins. It also stimulated apoptosis but reduced autophagic responses. These metformin-induced changes were clearly reversed by compound C, an inhibitor of AMP-activated protein kinase (AMPK). Interestingly, metformin massively increased the production of reactive oxygen species (ROS), which was completely blocked by compound C. Metformin also stimulated the phosphorylation of p38 mitogen-activated protein kinase (p38MAPK). Finally, inhibition of p38MAPK mimicked the effects of compound C, and suppressed the metformin-induced fat accumulation and apoptosis. Taken together, metformin stimulates dysregulated glucose metabolism, intracellular fat accumulation, and apoptosis. Our findings suggest that metformin induces excessive glucose-induced DNL, oxidative stress by ROS generation, activation of AMPK and p38MAPK, suppression of autophagy, and ultimately apoptosis.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2010.10a
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• pp.7-7
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• 2010

전 세계적으로 폭발적으로 증가하고 있는 비만은 만병의 근원이다. 동시에 대사성질환의 발병을 증가시키는 결정적인 역할을 하고 있다. 이러한 상황을 극복할 수 있는 안전하고 효능이 우수한 약의 개발이 매우 시급하다. 시판되는 약들은 예견할 수 없는 지방변으로 실제생활을 매우 불편하게 하는 부작용과 우울증 및 자살충동 등의 심각한 부작용을 유발시키고 있다. 특히 생명을 위협하는 약은 시판이 금지되었다. 200여종의 한약재들을 In vitro screening (pancreatic lipase inhibition, PDE inhibition, c-AMP activity), ex vivo screening (lipolytic action on fat pad), short term animal screening(혈중 TG 함량 분석)을 토대로 long term animal model에서비만 예방 및 치료 효능을 검증하기 위하여 호장근 부탄올 분획을 선정하였다. 고지방 사료로 비만을 유도한 rat (Diet induced obesty (DIO) rat)에서 비만 치료 효능이, 고지방 사료로 비만을 유도한 ICR-mice에서 비만 예방 효능이 우수함을 입증하였다 (체중감소, 지방세포의 크기억제, 지방간 예방/치료(간무게, TG함량, 간 색상, 고지혈증 증상억제), 혈중 TNF-a, IL-6, leptin, adponectin 등, 간 조직에서의 pAMPK, SOCS, NF-${\kappa}B$ DNA biding activity, ACC level, FAS expression, CPT-1 activity의 정상화). 호장근 부탄올 분획의 이러한 효능은 AMPK 작용과 CPT-1 작용을 활성화하고 동시에 지방산 합성 억제와 지방산 산화를 촉진함으로 인함임을 규명하였다. 동시에 비만으로 인한 pancreatic beta cell의 파괴를 예방함으로 인슐린 내성을 예방(치료)함을 입증하였다. 이는 AMPK 활성화와 SOCS-3 단백질 억제와 NF-${\kappa}B$-DNA 결합 억제로 인함임을 증명하였다. 3T3-L1 지방 세포주에서 lipogenesis 예방(치료) 및 lipolytic effect에 관여하는 인자들의 변화를 확인하였다. 이는 Multi-compounds-multi-targets에 의한 시너지 효과임을 알 수 있었다.

• Preventive Nutrition and Food Science
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• v.12 no.4
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• pp.197-201
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• 2007

Genistein is an active component of legumes and other related food shown to be associated with prevention of degenerative diseases such as cancer through inducing signaling pathways. Treatment of genistein resulted in the induction of apoptosis in the cultured cancer cells. This induction of apoptosis was demonstrated by the Tunel assay in these cells. Unveiling the potential of genistein in cytotoxicity via apoptosis when it is treated with estrogen can predict the therapeutic capability of genistein in breast cancers in the presence of endogenous estrogen. We have found that apoptosis induced by genistein treatment in the presence of estrogen is agonistic or antagonistic depending on the concentrations and treatment periods applied in MCF-7 breast cancer cells. For the suppression of cell survival, 24 hr of treatment was required to induce a synergistic agonistic response between estrogen and genistein at low concentrations of genistein. After this period, the agonistic pattern of genistein to estrogen disappeared. The decrement of COX-2 expression in MCF-7 cells treated with genistein was accompanied with the activation of AMPK only at a high concentration of genistein. This association between AMPK activation and down-regulation of COX-2 by genistein was dampened in the presence of estrogen. It was also demonstrated that genistein and estrogen regulate cell survival and apoptosis by modulating p53 and caspase-3 in the opposite direction. These results suggest that genistein has the potential to control breast cancer development, and co-treatment with estrogen can cause agonistic or antagonistic action on breast cancer cell control.

• The Korean Journal of Physiology and Pharmacology
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• v.26 no.5
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• pp.325-333
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• 2022

Heart failure (HF) has become one of the severe public health problems. The detailed role of mitochondrial function in HF was still unclear. Benzoylaconine (BAC) is a traditional Chinese medicine, but its role in HF still needs to be explored. In this study, oxygen-glucose deprivation and reperfusion (OGD/R) was executed to mimic the injury of H9C2 cells in HF. The viability of H9C2 cells was assessed via MTT assay. OGD/R treatment markedly decreased the viability of H9C2 cells, but BAC treatment evidently increased the viability of OGD/R-treated H9C2 cells. The apoptosis of H9C2 was enhanced by OGD/R treatment but suppressed by BAC treatment. The mitochondrial membrane potential was evaluated via JC-1 assay. BAC improved the mitochondrial function and suppressed oxidative stress in OGD/R-treated H9C2 cells. Moreover, Western blot analysis revealed that the protein expression of p-AMPK and PGC-1α were reduced in OGD/R-treated H9C2 cells, which was reversed by BAC. Rescue assays indicated that AMPK attenuation reversed the BAC-mediated protective effect on OGD/R-treated cardiomyocytes. Moreover, BAC alleviated myocardial injury in vivo. In a word, BAC modulated the mitochondrial function in OGD/R-induced cardiomyocyte injury by activation of the AMPK/PGC-1 axis. The findings might provide support for the application of BAC in the treatment of HF.

• IMMUNE NETWORK
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• v.20 no.3
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• pp.26.1-26.9
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• 2020

Cereblon (CRBN), a negative modulator of AMP-activated protein kinase (AMPK), is highly expressed in the retina. We confirmed the expression of CRBN in ARPE-19 human retinal cells by Western blotting. We also demonstrated that CRBN knock-down (KD) could effectively downregulate IL-6 and MCP-1 protein and gene expression in LPS-stimulated ARPE-19 cells. Additionally, CRBN KD increased the phosphorylation of AMPK/acetylcoenzyme A carboxylase (ACC) and the expression of heme oxygenase-1 (HO-1) in ARPE-19 cells. Furthermore, CRBN KD significantly reduced LPS-induced nuclear translocation of NF-κB p65 and activation of NF-κB promoter activity. However, these processes could be inactivated by compound C (inhibitor of AMPK) and zinc protoporphyrin-1 (ZnPP-1; inhibitor of HO-1). In conclusion, compound C and ZnPP-1 can rescue LPS-induced levels of proinflammatory cytokines (IL-6 and MCP-1) in CRBN KD ARPE-19 cells. Our data demonstrate that CRBN deficiency negatively regulates proinflammatory cytokines via the activation of AMPK/HO-1 in the retina.

• Molecules and Cells
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• v.45 no.3
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• pp.112-121
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• 2022

Calorie restriction (CR) and the activation of autophagy extend healthspan by delaying the onset of age-associated diseases in most living organisms. Because protein kinase CK2 (CK2) downregulation induces cellular senescence and nematode aging, we investigated CK2's role in CR and autophagy. This study indicated that CR upregulated CK2's expression, thereby causing SIRT1 and AMP-activated protein kinase (AMPK) activation. CK2α overexpression, including antisense inhibitors of miR-186, miR-216b, miR-337-3p, and miR-760, stimulated autophagy initiation and nucleation markers (increase in ATG5, ATG7, LC3BII, beclin-1, and Ulk1, and decrease in SQSTM1/p62). The SIRT1 deacetylase, AKT, mammalian target of rapamycin (mTOR), AMPK, and forkhead homeobox type O (FoxO) 3a were involved in CK2-mediated autophagy. The treatment with the AKT inhibitor triciribine, the AMPK activator AICAR, or the SIRT1 activator resveratrol rescued a reduction in the expression of lgg-1 (the Caenorhabditis elegans ortholog of LC3B), bec1 (the C. elegans ortholog of beclin-1), and unc-51 (the C. elegans ortholog of Ulk1), mediated by kin-10 (the C. elegans ortholog of CK2β) knockdown in nematodes. Thus, this study indicated that CK2 acted as a positive regulator in CR and autophagy, thereby suggesting that these four miRs' antisense inhibitors can be used as CR mimetics or autophagy inducers.

• Journal of Korean Medicine for Obesity Research
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• v.22 no.2
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• pp.93-101
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• 2022

Objectives: This study aimed to observe the anti-diabetic effect and underlying mechanisms of Galgunhwanggumhwangryun-tang (GHH; Gegen-Qinlian-decoction) in the C2C12 myotubes. Methods: GHH (1.0 mg/ml) or metformin (0.75 mM) or insulin (100 nM) were treated in C2C12 myotubes after 4 days differentiation. The glucose uptake was assessed by 2-[N-(7-160 nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-d-glucose uptake by C2C12 cells. The expression of adenosine monophosphate-activated protein kinase (AMPK) and phosphorylation AMPK (pAMPK) were measured by western blot. We also evaluated gene expression of glucose transporter type 4 (Slc2a4, formerly known as GLUT4), glucokinase (Gk), carnitine palmitoyltransferase IA (Cpt1a), nuclear respiratory factors 1 (Nrf1), mitochondrial transcription factor A (Tfam), and peroxisome proliferator-activated receptor γ coactivator 1α (Ppargc1a) by quantitative real-time polymerase chain reaction. Results: GHH promoted glucose uptake in C2C12 myotubes. The expression of AMPK protein, which plays an essential role in glucose metabolism, was increased by treatment with GHH. GHH treatment tended to increase gene expression of Slc2a4, Gk, and Nrf1 but was not statistically significant. However, GHH significantly improved Tfam and Ppargc1a gene expression in C2C12 myotubes. Conclusions: In summary, GHH treatment promoted glucose uptake in C2C12 myotubes. We suggest that these effects are associated with increased gene expression involved in mitochondrial biosynthesis and oxidative phosphorylation, such as Tfam and Ppargc1a, and increased expression of AMPK protein.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.8
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• pp.1190-1197
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• 2017

Objective: Adipose tissue is no longer considered as an inert storage organ for lipid, but instead is thought to play an active role in regulating insulin effects via secretion adipokines. However, conflicting reports have emerged regarding the effects of adipokines. In this study, we investigated the role of adipokines in glucose metabolism and insulin sensitivity in obese Bama mini-pigs. Methods: An obesity model was established in Bama mini-pigs, by feeding with high-fat and high-sucrose diet for 30 weeks. Plasma glucose and blood biochemistry levels were measured, and intravenous glucose tolerance test was performed. Adipokines, including adiponectin, interleukin-6 (IL-6), resistin and tumor necrosis factor alpha ($TNF-{\alpha}$), and glucose-induced insulin secretion were also examined by radioimmunoassay. AMP-activated protein kinase (AMPK) phosphorylation in skeletal muscle, which is a useful insulin resistance marker, was examined by immunoblotting. Additionally, associations of AMPK phosphorylation with plasma adipokines and homeostasis model assessment of insulin resistance (HOMA-IR) index were assessed by Pearce's correlation analysis. Results: Obese pigs showed hyperglycemia, high triglycerides, and insulin resistance. Adiponectin levels were significantly decreased (p<0.05) and IL-6 amounts dramatically increased (p<0.05) in obese pigs both in serum and adipose tissue, corroborating data from obese mice and humans. However, circulating resistin and $TNF-{\alpha}$ showed no difference, while the values of $TNF-{\alpha}$ in adipose tissue were significantly higher in obese pigs, also in agreement with data from obese humans but not rodent models. Moreover, strong associations of skeletal muscle AMPK phosphorylation with plasma adiponectin and HOMA-IR index were obtained. Conclusion: AMPK impairment induced by adiponectin decrease mediates insulin resistance in high-fat and high-sucrose diet induction. In addition, Bama mini-pig has the possibility of a conformable model for human metabolic diseases.