The present study was aimed to clarify the signaling molecular mechanism by which fibroblast growth factor 21 (FGF21) regulates leptin gene expression in adipocytes. Differentiated 3T3-F442A adipocytes were used as study object. The mRNA expression level of leptin was detected by fluorescence quantitative RT-PCR. The phosphorylation levels of proteins of signal transduction pathways were detected by Western blot. The results showed that FGF21 significantly down-regulated the mRNA expression level of leptin in adipocytes, and FGF21 receptor inhibitor BGJ-398 could completely block this effect. FGF21 up-regulated the phosphorylation levels of ERK1/2 and AMPK in adipocytes. Either ERK1/2 inhibitor SCH772984 or AMPK inhibitor Compound C could partially block the inhibitory effect of FGF21, and the combined application of these two inhibitors completely blocked the effect of FGF21. Neither PI3K inhibitor LY294002 nor Akt inhibitor AZD5363 affected the inhibitory effect of FGF21 on leptin gene expression. These results suggest that FGF21 may inhibit leptin gene expression by activating ERK1/2 and AMPK signaling pathways in adipocytes.
3T3 Cells ; Adenylate Kinase ; Adipocytes ; metabolism ; Animals ; Down-Regulation ; Fibroblast Growth Factors ; metabolism ; Leptin ; metabolism ; MAP Kinase Signaling System ; Mice ; Phosphorylation ; Signal Transduction

PURPOSE: To evaluate the effect of anti-interleukin-33 (anti-IL-33) on a mouse model of ovalbumin (OVA)-induced acute kidney injury (AKI). METHODS: Twenty-four female BALB/c mice were assigned to 4 groups: group A (control, n=6) was administered sterile saline intraperitoneally (i.p.) and intranasally (i.n.); group B (allergic, n=6) was administered i.p./i.n. OVA challenge; group C (null treatment, n=6) was administered control IgG i.p. before OVA challenge; and group D (anti-IL-33, n=6) was pretreated with 3.6 µg of anti-IL-33 i.p. before every OVA challenge. The following were evaluated after sacrifice: serum blood urea nitrogen and creatinine levels, Kidney injury molecule-1 gene (Kim-1) and protein (KIM-1) expression in renal parenchyma, and expression of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), phosphorylated endothelial NOS (p-eNOS), and phosphorylated AMP kinase (p-AMPK) proteins in renal parenchyma. RESULTS: After OVA injection and intranasal challenge, mice in groups B and C showed significant increases in the expression of Kim-1 at both the mRNA and protein levels. After anti-IL-33 treatment, mice in group D showed significant Kim-1 down-regulation at the mRNA and protein levels. Group D also showed significantly lower COX-2 protein expression, marginally lesser iNOS expression than groups B and C, and p-eNOS and p-AMPK expression at baseline levels. CONCLUSIONS: Kim-1 could be a useful marker for detecting early-stage renal injury in mouse models of OVA-induced AKI. Further, anti-IL-33 might have beneficial effects on these mouse models.
Acute Kidney Injury ; Adenylate Kinase ; Animals ; Blood Urea Nitrogen ; Creatinine ; Cyclooxygenase 2 ; Down-Regulation ; Female ; Humans ; Immunoglobulin G ; Interleukin-33 ; Kidney* ; Mice ; Nitric Oxide Synthase Type II ; Ovalbumin ; Ovum ; RNA, Messenger

OBJECTIVEInterferon-γ (IFN-γ) plays an important role in apoptosis and was shown to increase the risk of diabetes. Visfatin, an adipokine, has anti-diabetic, anti-tumor, and regulating inflammatory properties. In this study we investigated the effect of visfatin on IFN-γ-induced apoptosis in rat pancreatic β-cells.

METHODSThe RINm5F (rat insulinoma cell line) cells exposed to IFN-γ were treated with or without visfatin. The viability and apoptosis of the cells were assessed by using MTT and flow cytometry. The expressions of mRNA and protein were detected by using real-time PCR and western blot analysis.

RESULTSThe exposure of RINm5F cells to IFN-γ for 48 h led to increased apoptosis percentage of the cells. Visfatin pretreatment significantly increased the cell viability and reduced the cell apoptosis induced by IFN-γ. IFN-γ-induced increase in expression of p53 mRNA and cytochrome c protein, decrease in mRNA and protein levels of anti-apoptotic protein Bcl-2 were attenuated by visfatin pretreatment. Visfatin also increased AMPK and ERK1/2 phosphorylation and the anti-apoptotic action of visfatin was attenuated by the AMPK and ERK1/2 inhibitor.

CONCLUSIONThese results suggested that visfatin protected pancreatic islet cells against IFN-γ-induced apoptosis via mitochondria-dependent apoptotic pathway. The anti-apoptotic action of visfatin is mediated by activation of AMPK and ERK1/2 signaling molecules.

Adenylate Kinase ; metabolism ; Animals ; Apoptosis ; physiology ; Cell Line ; Cytokines ; physiology ; Flow Cytometry ; Interferon-gamma ; physiology ; Islets of Langerhans ; cytology ; MAP Kinase Signaling System ; Nicotinamide Phosphoribosyltransferase ; physiology ; Rats ; Real-Time Polymerase Chain Reaction ; Signal Transduction

BACKGROUND/OBJECTIVES: The purpose of this study was to examine the effects and associated mechanisms of arctiin, a lignan compound found in burdock, on adipogenesis in 3T3-L1 cells. Also, the effects of arctiin supplementation in obese mice fed a high-fat diet on adiposity were examined. MATERIALS/METHODS: 3T3-L1 cells were treated with arctiin (12.5 to 100 microM) during differentiation for 8 days. The accumulation of lipid droplets was determined by Oil Red O staining and intracellular triglyceride contents. The expressions of genes related to adipogenesis were measured by real-time RT-PCR and Western blot analyses. For in vivo study, C57BL/6J mice were first fed either a control diet (CON) or high-fat diet (HF) to induce obesity, and then fed CON, HF, or HF with 500 mg/kg BW arctiin (HF + AC) for four weeks. RESULTS: Arctiin treatment to 3T3-L1 pre-adipocytes markedly decreased adipogenesis in a dose-dependent manner. The arctiin treatment significantly decreased the protein levels of the key adipogenic regulators PPARgamma and C/EBPalpha, and also significantly inhibited the expression of SREBP-1c, fatty acid synthase, fatty acid-binding protein and lipoprotein lipase. Also, arctiin greatly increased the phosphorylation of AMP-activated protein kinase (AMPK) and its downstream target phosphorylated-acetyl CoA carboxylase. Furthermore, administration of arctiin significantly decreased the body weight in obese mice fed with the high-fat diet. The epididymal, perirenal or total visceral adipose tissue weights of mice were all significantly lower in the HF + AC than in the HF. Arctiin administration also decreased the sizes of lipid droplets in the epididymal adipose tissue. CONCLUSIONS: Arctiin inhibited adipogenesis in 3T3-L1 adipocytes through the inhibition of PPARgamma and C/EBPalpha and the activation of AMPK signaling pathways. These findings suggest that arctiin has a potential benefit in preventing obesity.
3T3-L1 Cells* ; Adenylate Kinase ; Adipocytes ; Adipogenesis* ; Adipose Tissue ; Adiposity* ; AMP-Activated Protein Kinases ; Animals ; Blotting, Western ; Body Weight* ; Diet ; Diet, High-Fat* ; Intra-Abdominal Fat ; Lipoprotein Lipase ; Mice* ; Mice, Obese ; Obesity ; Phosphorylation ; PPAR gamma ; Sterol Regulatory Element Binding Protein 1 ; Triglycerides ; Weights and Measures

Modified Si-Miao-San (mSMS) is composed of Rhizoma Coptidis, Cortex Phellodendri, Rhizoma Coptidis Semen Coicis and Atractylodes Rhizome. The prescription is used for the management of diabetes and insulin resistance in the clinic. This study aims to investigate its regulation of glucose disposal in adipocytes. Differentiated 3T3-L1 adipocytes were stimulated with conditioned medium derived from activated macrophages to induce insulin resistance and observed the effects of Mac-CM on insulin-mediated glucose uptake along the insulin receptor substrate-1/PI3K/Akt signaling pathway. Moreover, its regulation of AMPK phosphorylation was also investigated. mSMS enhanced AMPK phosphorylation and promoted basal glucose uptake in adipocytes; mSMS inhibited NF-κB activation by reducing P65 phosphorylation and improved insulin-stimulated IRS-1 tyrosine and Akt phosphorylation, leading to the restoration of insulin-mediated glucose uptake when cells were exposed to inflammatory stimulation. These beneficial effects were diminished in the presence of the AMPK inhibitor compound C. mSMS positively regulated AMPK activity, and this action contributed to improving insulin PI3K signaling by the beneficial regulation of IRS-1 function through inhibition of inflammation in adipocytes.
3T3-L1 Cells ; Adenosine Monophosphate ; metabolism ; Adenylate Kinase ; metabolism ; Adipocytes ; drug effects ; metabolism ; Animals ; Atractylodes ; Coix ; Coptis ; Diabetes Mellitus ; drug therapy ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Glucose ; metabolism ; Glucose Transporter Type 4 ; metabolism ; Inflammation ; metabolism ; prevention & control ; Insulin ; metabolism ; Insulin Receptor Substrate Proteins ; metabolism ; Insulin Resistance ; Mice ; NF-kappa B ; metabolism ; Phellodendron ; Phosphatidylinositol 3-Kinases ; metabolism ; Phosphorylation ; Phytotherapy ; Proto-Oncogene Proteins c-akt ; metabolism ; Signal Transduction

OBJECTIVETo investigate the underlying molecular mechanism of the cholesterol-blocking drug, simvastatin, in treating nonalcoholic fatty liver fibrosis.

METHODA rat model of nonalcoholic fatty liver fibrosis was established by feeding Wistar rats a fat-rich diet. After treatment with simvastatin (4 mg/kg/day), liver histological specimens were stained with hematoxylin-eosin and Masson's trichrome for microscopic analysis. Expression of adenosine monophosphate-activated protein kinase-alpha (AMPKa) was evaluated by reverse transcription-polymerase chain reaction (RT-PCR; for mRNA) and Western blotting (protein). The levels of serum total cholesterol (TC), triglycerides (TG), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and tumor necrosis factor-alpha (TNFa) were measured by standard biochemical assays. The human hepatic stellate cell line, LX-2 (quiescent or activated), was treated with transforming growth factor-beta 1 (TGF-b1) alone, simvastatin alone, or TGF-b1 + simvastatin. RT-PCR and Western blotting were used to determine changes in AMPKa mRNA and protein expression, respectively.

RESULTSIn the rat model of nonalcoholic fatty liver fibrosis, the extent of pathological changes in hepatic tissues correlated with severity of disease progression. The levels of serum TC, TG, ALT, AST and TNFa were increased significantly in model rats (vs. healthy controls; all, P less than 0.01). AMPKa mRNA expression and activity was significantly decreased in model rats (vs. healthy controls; P less than 0.01 and P less than 0.05, respectively). Simvastatin, treatment significantly improved all of these parameters in model rats (vs. untreated model rats; all, P less than 0.05). In vitro simvastatin treatment of human HSCs significantly increased AMPKa activity (quiescent LX-2: 0.93+/-0.10 vs. 0.72+/-0.09, activated LX-2: 0.72+/-0.10 vs. 0.54+/-0.10, q=7.00, 6.00; all, P less than 0.01), decreased a-smooth muscle actin expression (mRNA: 0.30+/-0.02 vs. 0.36+/-0.02, protein: 0.30+/-0.03 vs. 0.38+/-0.02, q=11.245, 11.216; all, P less than 0.01), and decreased collagen I expression (mRNA: 0.30+/-0.03 vs. 0.37+/-0.03, protein: 0.25+/-0.03 vs. 0.33+/-0.03, q=8.791, 11.163; all, P less than 0.01).

CONCLUSIONSimvastatin may improve nonalcoholic fatty liver fibrosis by inducing AMPK phosphorylation.

Adenylate Kinase ; metabolism ; Animals ; Cell Line ; Fatty Liver ; drug therapy ; metabolism ; pathology ; Hepatic Stellate Cells ; drug effects ; enzymology ; Humans ; Liver Cirrhosis ; metabolism ; pathology ; Male ; Rats ; Rats, Wistar ; Simvastatin ; pharmacology ; therapeutic use

OBJECTIVETo investigate the effects of Chang-Chul-Eui-Ee-In-Tang ([see text], CCEET), modififi ed CCEET (MCCEET), and Semen Coicis (SC, a major component of CCEET) on energy and glucose homeostasis. The possible mechanism of action of CCEET was also determined.

METHODSA total of 100 Sprague Dawley female rats were randomly assigned to 5 groups, with 20 in each group. Rats in 4 groups were fed with a high fat diet supplementation (2 g/kg body weight), and water extracts of CCEET, MCCEET, SC, and cellulose (negative control), respectively. The last group was fed with a low-fat diet as a positive control.

RESULTSCCEET and MCCEET decreased body weight and body fat (mesenteric and retroperitoneal fat) more than SC. This decrease was due to decreased energy intake and increased energy expenditure and fat oxidation. The improvement in energy homeostasis was associated with the enhancement of the hypothalamic leptin signalling pathway involving potentiating the phosphorylation of the signal transducer and activator of transcription-3, as well as attenuating the phosphorylation of 5' adenosine monophosphate-activated protein kinase (AMPK). Both CCEET and MCCEET improved glucose tolerance without changing serum insulin levels during an oral glucose tolerance test but MCCEET had a better effect than CCEET.

CONCLUSIONSBoth CCEET and MCCEET safely exerted anti-obesity effects by enhancing energy balance in female rats with diet-induced obesity; MCCEET showed a better effect on glucose homeostasis.

Adenylate Kinase ; metabolism ; Adipose Tissue ; drug effects ; Animals ; Anti-Obesity Agents ; adverse effects ; pharmacology ; therapeutic use ; Blood Glucose ; metabolism ; Body Weight ; drug effects ; Calorimetry ; Diet ; Drugs, Chinese Herbal ; adverse effects ; pharmacology ; therapeutic use ; Energy Metabolism ; drug effects ; Female ; Glucose Tolerance Test ; Homeostasis ; drug effects ; Hypothalamus ; drug effects ; enzymology ; Leptin ; metabolism ; Motor Activity ; drug effects ; Obesity ; blood ; drug therapy ; pathology ; physiopathology ; Phosphorylation ; drug effects ; Rats ; Rats, Sprague-Dawley ; STAT3 Transcription Factor ; metabolism ; Signal Transduction ; drug effects

OBJECTIVETo clone the gene encoding adenylate kinase of Thermus thermophilus HB27, an extremely thermophilic bacterium, express the protein in Escherichia coil and study the enzymatic characterization.

METHODSThe DNA fragment encoding adenylate kinase was obtained by PCR from the total DNA of Thermus thermophilus HB27 and cloned into the vector pET-28a. The recombinant plasmid was identified by PCR, restriction endonuclease digestion and sequence analysis. Enzymatic characterization of the expressed protein was carried out using spectrophotometric assays.

RESULTSThe gene coding for adenylate kinase from Thermus thermophilus HB27 was cloned and the protein was overexpressed in Escherichia coli BL21(DE3). The optimum reactive pH and temperature for the enzyme were 8.5 and 90 degrees celsius;, respectively. The Km of the recombinant adenylate kinase for ADP was 68.6 micromol/L, with an V(max)ADP of 0.294 mmol/(L.min). Under the condition of environmental temperature at 70, 80, 90, or 100 degrees celsius; for 7 h, the recombinant adenylate kinase still retained the enzymatic activity with high thermostability. AP5A, a specific adenylate kinase inhibitor, inhibited the enzymatic activity of the protein by 70% at the concentration of 2.0 mmol/L, with a Ki value of 46.39 micromol/L for ADP.

CONCLUSIONThe gene coding for adenylate kinase of Thermus thermophilus HB27 has been successfully cloned and expressed in Escherichia coil, which provides the basis for potential use of the highly thermostable recombinant HB27 adenylate kinase.

Adenylate Kinase ; biosynthesis ; genetics ; metabolism ; Amino Acid Sequence ; Cloning, Molecular ; Enzyme Stability ; Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; genetics ; Molecular Sequence Data ; Recombinant Proteins ; biosynthesis ; genetics ; metabolism ; Thermus thermophilus ; enzymology

Extracellular ATP (exATP) has been known to be a critical ligand regulating skeletal muscle differentiation and contractibility. ExATP synthesis was greatly increased with the high level of adenylate kinase 1 (AK1) and ATP synthase beta during C2C12 myogenesis. The exATP synthesis was abolished by the knock-down of AK1 but not by that of ATP synthase beta in C2C12 myotubes, suggesting that AK1 is required for exATP synthesis in myotubes. However, membrane-bound AK1beta was not involved in exATP synthesis because its expression level was decreased during myogenesis in spite of its localization in the lipid rafts that contain various kinds of receptors and mediate cell signal transduction, cell migration, and differentiation. Interestingly, cytoplasmic AK1 was secreted from C2C12 myotubes but not from C2C12 myoblasts. Taken together all these data, we can conclude that AK1 secretion is required for the exATP generation in myotubes.
Adenosine Triphosphate/*biosynthesis ; Adenylate Kinase/*metabolism ; Animals ; Cell Line ; Extracellular Space/metabolism ; Isoenzymes/*metabolism ; Mice ; Muscles/cytology/*metabolism

BACKGROUND: Normal cell proliferation and viability is strongly depends on the availability of metabolic energy and the maintenance of the appropriate adenylate-nucleotide pools. Hypothetically, changes in adenylate kinase (AK) expression could therefore be associated with adaptation to altered growth characteristics or inversely altered growth characteristics of proliferating cells could drive the changes in the metabolic profile. This study investigated whether the expression of either AK1 or a Mycobacterium tuberculosis adenylate kinase mutant which has the same catalytic activity of AK1 could affect the growth rate of slow-growing BCG. METHOD: Recombinant BCGs, which were cloned the human muscle-type adenylate kinase synthetic gene (AK1) and adenylate kinase mutation gene (AKmtDM) of Mycobacterium tuberculosis into the Mycobacterium/E.coli expression vectors, were constructed. Recombinant BCGs and wild-type BCG were cultured in 7H9 media and the optical density at 600nm was measured at intervals of 2-3 days. RESULT: There wasn't the growth rate change induced by AK1 or AKmtDM expression in recombinant BCGs. CONCLUSION: The expression of AK1 or Mycobacterium tuberculosis adenylate kinase mutant in BCG does not affect the growth rate of BCG.
Adenylate Kinase* ; Cell Proliferation ; Clone Cells* ; Genes, Synthetic* ; Humans* ; Metabolome ; Mycobacterium bovis* ; Mycobacterium tuberculosis* ; Mycobacterium*