BACKGROUNDRecent studies on bone have shown an endocrine role of the skeleton, which could be impaired in various human diseases, including osteoporosis, obesity, and diabetes-associated bone diseases. As a sensor and regulator of energy metabolism, AMP-activated protein kinase (AMPK) may also play an important role in the regulation of bone metabolism. The current study aimed to establish the expression profiles and phosphorylation patterns of AMPK subunits in several mesenchymal cell types.

METHODSReverse transcription-polymerase chain reaction (PCR) for relative quantification, real-time PCR for absolute quantification, and Western blotting were used to investigate the gene expression profiles and phosphorylation patterns of AMPK subunits in several mesenchymal cell types, including primary human mesenchymal stem cells (hMSCs) and hFOB, Saos-2, C3H/10T1/2, MC3T3-E1, 3T3-L1, and C2C12 cells.

RESULTSAMPKα1 and AMPKβ1 mRNAs were abundantly expressed in all cell types. AMPKγ1 mRNA was abundantly expressed in C3H/10T1/2, MC3T3-E1, 3T3-L1, and C2C12 but not detected in human-derived cell types. AMPKγ2 mRNA was mildly expressed in all cell types. AMPKα1 protein was highly expressed in all cell types and AMPKα2 protein was highly expressed only in hFOB and Saos-2 cells. AMPKβ1 protein was abundantly expressed in all cell types except for Saos-2, in which AMPKβ2 protein overwhelmed AMPKβ1 expression. AMPKγ1 and AMPKγ2 proteins were expressed in C3H/10T1/2, MC3T3-E1, 3T3-L1, and C2C12 cells and only AMPKγ2 protein was expressed in hMSCs, hFOB and Saos-2 cells. AMPKα was phosphorylated at Thr172 and Ser485 and AMPKβ1 was phosphorylated at Ser108 and Ser182 in all cell types with a specific pattern in each cell type.

CONCLUSIONThe combination of AMPK α, β, and γ subunits and phosphorylation of AMPKα (Thr172 and Ser485) and AMPKβ1 (Ser108 and Ser182) showed a specific pattern in each cell type.

AMP-Activated Protein Kinases ; genetics ; metabolism ; Animals ; Cell Line ; Humans ; Mesenchymal Stromal Cells ; enzymology ; Mice ; Phosphorylation

Alcoholic liver disease(ALD), with its increasing morbidity and mortality, has seriously and extensively affected the health of people worldwide. Methyl ferulic acid(MFA) has been proven to significantly inhibit alcohol-induced lipid production in L02 cells through the AMP-activated protein kinase(AMPK) pathway, but its in-depth mechanism remains unclear. This study aimed to further clarify the mechanism of MFA in improving lipid accumulation in L02 cells through the microRNA-378b(miR-378b)-mediated calcium/calmodulin-dependent protein kinase kinase 2(CaMKK2)-AMPK signaling pathway based on existing researches. L02 cells were induced by 100 mmol·L~(-1) ethanol for 48 h to establish the model of ALD in vitro, and 100, 50, and 25 μmol·L~(-1) concentration of MFA was treated. MiR-378b plasmids(containing the overexpression plasmid-miR-378b mimics, silence plasmid-miR-378b inhibitor, and their respective negative control-miR-378b NCs) were transfected into L02 cells by electroporation to up-regulate or down-regulate the levels of miR-378b in L02 cells. The levels of total cholesterol(TC) and triglyceride(TG) in cells were detected by commercial diagnostic kits and automatic biochemical analyzers. The expression levels of miR-378b in L02 cells were detected by real-time quantitative polymerase chain reaction(qRT-PCR). CaMKK2 mRNA levels were detected by PCR, and protein expressions of related factors involved in lipid synthesis, decomposition, and transport in lipid metabolism were detected by Western blot. The results displayed that ethanol significantly increased TG and TC levels in L02 cells, while MFA decreased TG and TC levels. Ethanol up-regulated the miR-378b level, while MFA effectively inhibited the miR-378b level. The overexpression of miR-378b led to lipid accumulation in ethanol-induced L02 cells, while the silence of miR-378b improved the lipid deposition induced by ethanol. MFA activated the CaMKK2-AMPK signaling pathway by lowering miR-378b, thus improving lipid synthesis, decomposition, and transport, which improved lipid deposition in L02 cells. This study shows that MFA improves lipid deposition in L02 cells by regulating the CaMKK2-AMPK pathway through miR-378b.
Humans ; Ethanol/toxicity* ; AMP-Activated Protein Kinases/metabolism* ; Fatty Liver ; Triglycerides ; MicroRNAs/genetics* ; Calcium-Calmodulin-Dependent Protein Kinase Kinase/genetics*

The study is aimed to confirm the silencing efficiency of the vector in human hepatocellular liver carcinoma cell line (HepG2), and observe effects of AMPKgamma silencing on the AMPK stimulating activity and lipid synthesis of cordycepin (CCS), a natural product with known AMPK activating function. The downregulating efficacy of siRNAs on AMPKgamma expression was confirmed in our previous study. The double stranded shRNA Oligo was ligated to lentivirus vector and verified by sequencing. The lentiviral which can effectively inhibited protein expression levels of AMPKgamma was selected by Western blotting, and the regulation of CCS on protein expression of AMPKgamma and p-AMPK in AMPKgamma silence cells were detected by Western blotting analysis. The lipid accumulation in cells was observed by Oil-Red O stain and cells were collected for the estimation of cholesterol (TC), triglyceride (TG). The results showed that the lentiviral vector carrying a shRNA targeting the AMPKgamma gene was successfully constructed. Western blotting analysis confirmed that GR085 had the highest interfering efficiency. Treatment with CCS can significantly increase the levels of phospho-AMPK in normal cells, and the level of TC, TG was reduced, but in AMPKgamma silence cells the effects of CCS on AMPK activation and lipid synthesis were almost completely abolished without changing the expression levels of total AMPK or AMPKgamma protein. In conclusion, the AMPKgamma gene may be related to AMPK activation and intracellular lipids regulation by CCS.
AMP-Activated Protein Kinases ; genetics ; metabolism ; Cholesterol ; metabolism ; Deoxyadenosines ; pharmacology ; Genetic Vectors ; HEK293 Cells ; Humans ; Lentivirus ; genetics ; Phosphorylation ; RNA Interference ; RNA, Small Interfering ; genetics ; Triglycerides ; metabolism

Construction and ethanol production effects of SNF4 gene knockout in Saccharomyces cerevisiae were described in this paper. For knockout of SNF4 gene in S. cerevisiae YS2, a PCR-amplified disruption cassette was used, encoding the short flanking homologous regions to the SNF4 gene and Kan(r) as selectable marker. The SNF4 gene disruption cassette was transformed into S. cerevisiae YS2 through LiAc/SS Carrier DNA/PEG. The positive transformants were grown on G418 plates and verified by PCR. The Kan(r) marker was rescued by transforming plasmid pSH65 into positive transformants and inducing expression of Cre recombinase in galactose-containing medium. Lastly, the YS2-deltaSNF4 strain, in which SNF4 allele gene were completely knocked out, was obtained by repeating the same procedure. The result of anaerobic fermentation showed that ethanol production of the SNF4 gene knockout strain had increased by 7.57 percent as compared with the original strain YS2. The experiment indicated ethanol production could be improved significantly with the approach ofSNF4 gene knockout by Cre-LoxP system.
AMP-Activated Protein Kinases ; genetics ; Ethanol ; metabolism ; Fermentation ; Gene Knockout Techniques ; methods ; Mutation ; Saccharomyces cerevisiae ; genetics ; Saccharomyces cerevisiae Proteins ; genetics ; Transcription Factors ; genetics

OBJECTIVES: In this study, we explored how adiponectin mediated urotensin II (UII)‍-induced tumor necrosis factor-‍α (TNF-‍α) and α‍-smooth muscle actin (α‍-SMA) expression and ensuing intracellular signaling pathways in adventitial fibroblasts (AFs). METHODS: Growth-arrested AFs and rat tunica adventitia of vessels were incubated with UII and inhibitors of signal transduction pathways for 1‍‒‍24 h. The cells were then harvested for TNF-α receptor (TNF-‍α-R) messenger RNA (mRNA) and TNF-‍α protein expression determination by reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. Adiponectin and adiponectin receptor (adipoR) expression was measured by RT-PCR, quantitative real-time PCR (qPCR), immunohistochemical analysis, and cell counting kit-8 (CCK-8) cell proliferation experiments. We then quantified TNF-α and α-SMA mRNA and protein expression levels by qPCR and immunofluorescence (IF) staining. RNA interference (RNAi) was used to explore the function of the adipoR genes. To investigate the signaling pathway, we applied western blotting (WB) to examine phosphorylation of adenosine 5'-monophosphate (AMP)‍-activated protein kinase (AMPK). In vivo, an adiponectin (APN)‍-knockout (APN-KO) mouse model mimicking adventitial inflammation was generated to measure TNF-α and α‍-SMA expression by application of qPCR and IF, with the goal of gaining a comprehensive atlas of adiponectin in vascular remodeling. RESULTS: In both cells and tissues, UII promoted TNF-α protein and TNF-α-R secretion in a dose- and time-dependent manner via Rho/protein kinase C (PKC) pathway. We detected marked expression of adipoR1, T-cadherin, and calreticulin as well as a moderate presence of adipoR2 in AFs, while no adiponectin was observed. Globular adiponectin (gAd) fostered the growth of AFs, and acted in concert with UII to induce α-SMA and TNF-α through the adipoR1/T-cadherin/calreticulin/AMPK pathway. In AFs, gAd and UII synergistically induced AMPK phosphorylation. In the adventitial inflammation model, APN deficiency up-regulated the expression of α-SMA, UII receptor (UT), and UII while inhibiting TNF-‍α expression. CONCLUSIONS From the results of our study, we can speculate that UII induces TNF‍-‍α protein and TNF-‍α‍-R secretion in AFs and rat tunica adventitia of vessels via the Rho and PKC signal transduction pathways. Thus, it is plausible that adiponectin is a major player in adventitial progression and could serve as a novel therapeutic target for cardiovascular disease administration.
Mice ; Rats ; Animals ; Adventitia/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Calreticulin/metabolism* ; Vascular Remodeling ; AMP-Activated Protein Kinases/metabolism* ; Cells, Cultured ; RNA, Messenger/genetics* ; Inflammation

OBJECTIVETo construct pGPU6/GFP/Neo-shRNA expression vector targeting human AMPKα2 gene and evaluate its silencing effect in SH-SY5Y cell line.

METHODSThe oligonucleotides designed by Ambion online CAD software targeting AMPKα2 were cloned into the pGPU6/GFP/Neo vector. After confirmation by DNA sequencing and enzyme digestion analysis, the recombinant vectors were transfected into the SH-SY5Y cell line via lipofectamine and the positive clones were selected using G418. The expression levels of AMPKα2 mRNA and protein in the transfected cells were detected by RT-PCR and Western blotting, respectively.

RESULTSFour shRNA vectors were successfully constructed as confirmed by DNA sequencing and the enzyme digestion analysis. Among the 4 recombinant vectors, pGPU6/GFP/Neo-shRNA AMPKα2(3) showed the strongest gene silencing effect and down-regulated the protein expression of AMPKα2 by 63% in the transfected cells.

CONCLUSIONTransfection with pGPU6/GFP/Neo-shRNA AMPKα2(3) results in effective inhibition of AMPKα2 gene expression in SH-SY5Y cells, which provide a means for studying AMPK-mediated cell injury.

AMP-Activated Protein Kinases ; genetics ; Cell Line ; Gene Targeting ; methods ; Genetic Vectors ; genetics ; Humans ; RNA Interference ; RNA, Small Interfering ; genetics ; metabolism ; Transfection

Previous studies have shown that long-term spermatogonial stem cells (SSCs) have the potential to spontaneously transform into pluripotent stem cells, which is speculated to be related to the tumorigenesis of testicular germ cells, especially when p53 is deficient in SSCs which shows a significant increase in the spontaneous transformation efficiency. Energy metabolism has been proved to be strongly associated with the maintenance and acquisition of pluripotency. Recently, we compared the difference in chromatin accessibility and gene expression profiles between wild-type (p53^+/+) and p53 deficient (p53^-/-) mouse SSCs using the Assay for Targeting Accessible-Chromatin with high-throughput sequencing (ATAC-seq) and transcriptome sequencing (RNA-seq) techniques, and revealed that SMAD3 is a key transcription factor in the transformation of SSCs into pluripotent cells. In addition, we also observed significant changes in the expression levels of many genes related to energy metabolism after p53 deletion. To further reveal the role of p53 in the regulation of pluripotency and energy metabolism, this paper explored the effects and mechanism of p53 deletion on energy metabolism during the pluripotent transformation of SSCs. The results of ATAC-seq and RNA-seq from p53^+/+ and p53^-/- SSCs revealed that gene chromatin accessibility related to positive regulation of glycolysis and electron transfer and ATP synthesis was increased, and the transcription levels of genes encoding key glycolytic enzymes and regulating electron transport-related enzymes were markedly increased. Furthermore, transcription factors SMAD3 and SMAD4 promoted glycolysis and energy homeostasis by binding to the chromatin of the Prkag2 gene which encodes the AMPK subunit. These results suggest that p53 deficiency activates the key enzyme genes of glycolysis in SSCs and enhances the chromatin accessibility of genes associated with glycolysis activation to improve glycolysis activity and promote transformation to pluripotency. Moreover, SMAD3/SMAD4-mediated transcription of the Prkag2 gene ensures the energy demand of cells in the process of pluripotency transformation and maintains cell energy homeostasis by promoting AMPK activity. These results shed light on the importance of the crosstalk between energy metabolism and stem cell pluripotency transformation, which might be helpful for clinical research of gonadal tumors.
Animals ; Mice ; AMP-Activated Protein Kinases ; Chromatin ; Energy Metabolism ; Gene Deletion ; Stem Cells ; Tumor Suppressor Protein p53/genetics* ; Spermatogonia/cytology* ; Male

OBJECTIVES: Genetic mutation is one of the important causes for tumor genesis and development, but genetic mutation in nasopharyngeal carcinoma (NPC) has rarely been reported. This study explored the role of phosphatidylinositol 3 kinase-protein kinase B (PI3K-Akt), mammalian target of rapamycin (mTOR), and adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) signaling pathway in the efficacy and prognosis in patients with NPC. METHODS: A total of 31 patients with advanced NPC, who came from the Affiliated Cancer Hospital of Xiangya School of Medicine of Central South University/Hunan Provincial Cancer Hospital, were enrolled. All of the exons of 288 genes, introns of 38 genes and promoters or fusion breakpoint regions from the nasopharyngeal biopsy tissues before treatment were detected by the gene sequencing platform Illumina NextSeq CN500. The coding regions of 728 genes were carried out a high-depth sequencing of target region capture, and the 4 variant types of tumor genes (including point mutations, insertion deletions of small fragments, copy number variations, and currently known fusion genes) were detected. All of 31 patients received platinum-based induction chemotherapy combined with concurrent chemoradiotherapy and were followed up for a long time. RESULTS: The 3-year regional failure-free survival (RFFS) and disease-free survival (DFS) in patients with PI3K-Akt pathway mutation were significantly lower than those in unmutated patients (χ²=6.647, P<0.05). The 3-year RFFS and DFS in patients with mTOR pathway mutations were significantly lower than those in unmutated patients, and there was significant difference (χ²=5.570, P<0.05). The rate of complete response (CR) in patients with unmutated AMPK pathway was significantly higher than that in patients with mutation at 3 months after treatment (P<0.05), and the 3-year RFFS and DFS in patients with AMPK pathway mutation were significantly lower than those in unmutated patients (χ²=4.553, P<0.05). PI3K-Akt/mTOR/AMPK signaling pathway mutations and pre-treatment EB virus DNA copy numbers were independent prognostic factors for 3-year RFFS and DFS in patients with NPC (both P<0.05). CONCLUSIONS The NPC patients with PI3K-Akt/mTOR/AMPK signaling pathway mutation have poor prognosis, and the detection of PI3K-Akt, mTOR, AMPK driver genes and signaling pathways by next-generation sequencing is expected to provide new idea for basic research and targeted therapy of NPC.
AMP-Activated Protein Kinases/metabolism* ; DNA Copy Number Variations ; Humans ; Mutation ; Nasopharyngeal Carcinoma/genetics* ; Nasopharyngeal Neoplasms/metabolism* ; Phosphatidylinositol 3-Kinases/metabolism* ; Prognosis ; Proto-Oncogene Proteins c-akt/metabolism* ; Signal Transduction ; Sirolimus ; TOR Serine-Threonine Kinases/metabolism*

Catechins have been proven to exert antitumor effects in different kinds of cancers. However, the underlying mechanisms have not been completely clarified yet. This study aimed to assess the effects and mechanisms of (-)-epigallocatechin-3-gallate (EGCG) and (-)-epicatechin-3-gallate (ECG) on human melanoma skin A375 cells. Results showed that EGCG and ECG inhibited the proliferation of A375 cells and ECG showed better inhibitory effect. Flow cytometry analysis had shown that EGCG and ECG induced apoptosis and led to cell cycle arrest. EGCG and ECG decreased Bcl-2 expression and upregulated Caspase-3 protein level, indicating the development of apoptosis. Furthermore, EGCG and ECG could decreased mitochondrial membrane potential of A375 cells. In addition, the expression of Beclin-1, LC3 and Sirt3 were downregulated at protein levels, which known to be associated with autophagy. After autophagy was increased by rapamycin, the apoptotic trend was not change, indicating that apoptosis and autophagy are independent. Mechanistically, EGCG and ECG treatments decreased phosphorylated-AMPK (p-AMPK) and increased the ratios of p-PI3K, p-AKT and p-mTOR in melanoma cells. Conclusively, EGCG and ECG induced apoptosis via mitochondrial signaling pathway, downregulated autophagy through modulating the AMPK/mTOR and PI3K/AKT/mTOR signaling pathway. It indicated that EGCG and ECG may be utilized in human melanoma treatment.
AMP-Activated Protein Kinases/genetics* ; Apoptosis ; Autophagy ; Catechin/analogs & derivatives* ; Electrocardiography ; Humans ; Melanoma/drug therapy* ; Phosphatidylinositol 3-Kinases/metabolism* ; Proto-Oncogene Proteins c-akt/metabolism* ; TOR Serine-Threonine Kinases/metabolism*

The present study investigated the pharmaceutical effect and underlying mechanism of Zexie Decoction(ZXD) on nonalcoholic fatty liver disease(NAFLD) in vitro and in vivo via the LKB1/AMPK/PGC-1α pathway based on palmitic acid(PA)-induced lipid accumulation model and high-fat diet(HFD)-induced NAFLD model in mice. As revealed by the MTT assay, ZXD had no effect on HepG2 activity, but dose-dependently down-regulated alanine aminotransferase(ALT) and aspartate aminotransferase(AST) in the liver cell medium induced by PA, and decreased the plasma levels of ALT and AST, and total cholesterol(TC) and triglyceride(TG) levels in the liver. Nile red staining showed PA-induced intracellular lipid accumulation, significantly increased lipid accumulation of hepatocytes induced by PA, suggesting that the lipid accumulation model in vitro was properly induced. ZXD could effectively improve the lipid accumulation of hepatocytes induced by PA. Oil red O staining also demonstrated that ZXD improved the lipid accumulation in the liver of HFD mice. JC-1 staining for mitochondrial membrane potential indicated that ZXD effectively reversed the decrease in mitochondrial membrane potential caused by hepatocyte injury induced by PA, activated PGC-1α, and up-regulated the expression of its target genes, such as ACADS, CPT-1α, CPT-1β, UCP-1, ACSL-1, and NRF-1. In addition, as revealed by the Western blot and immunohistochemistry, ZXD up-regulated the protein expression levels of LKB1, p-AMPK, p-ACC, and PGC-1α in vivo and in vitro. In conclusion, ZXD can improve NAFLD and its mechanism may be related to the regulation of the LKB1/AMPK/PGC-1α pathway.
AMP-Activated Protein Kinases/metabolism* ; Alanine Transaminase/metabolism* ; Animals ; Diet, High-Fat ; Liver/metabolism* ; Mice ; Mice, Inbred C57BL ; Non-alcoholic Fatty Liver Disease/genetics* ; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha