scholarly journals PEG-BHD1028 Peptide Regulates Insulin Resistance and Fatty Acid β-Oxidation, and Mitochondrial Biogenesis by Binding to Two Heterogeneous Binding Sites of Adiponectin Receptors, AdipoR1 and AdipoR2

2021 ◽  
Vol 22 (2) ◽  
pp. 884
Author(s):  
In Kyung Lee ◽  
Gyuyoup Kim ◽  
Do-Hwi Kim ◽  
Brian B. Kim
Keyword(s):  
Insulin Resistance ◽  
Fatty Acid ◽  
Mitochondrial Biogenesis ◽  
Binding Sites ◽  
Action Spectrum ◽  
C2c12 Cells ◽  
In Vivo Models ◽  
Insulin Resistant

Adiponectin plays multiple critical roles in modulating various physiological processes by binding to its receptors. The functions of PEG-BHD1028, a potent novel peptide agonist to AdipoRs, was evaluated using in vitro and in vivo models based on the reported action spectrum of adiponectin. To confirm the design concept of PEG-BHD1028, the binding sites and their affinities were analyzed using the SPR (Surface Plasmon Resonance) assay. The results revealed that PEG-BHD1028 was bound to two heterogeneous binding sites of AdipoR1 and AdipoR2 with a relatively high affinity. In C2C12 cells, PEG-BHD1028 significantly activated AMPK and subsequent pathways and enhanced fatty acid β-oxidation and mitochondrial biogenesis. Furthermore, it also facilitated glucose uptake by lowering insulin resistance in insulin-resistant C2C12 cells. PEG-BHD1028 significantly reduced the fasting plasma glucose level in db/db mice following a single s.c. injection of 50, 100, and 200 μg/Kg and glucose tolerance at a dose of 50 μg/Kg with significantly decreased insulin production. The animals received 5, 25, and 50 μg/Kg of PEG-BHD1028 for 21 days significantly lost their weight after 18 days in a range of 5–7%. These results imply the development of PEG-BHD1028 as a potential adiponectin replacement therapeutic agent.

Abstract 344: FNDC5, a PGC1-a-Dependent Myokine, Increases Glucose Utilization and Fatty-Acid Oxidation by AMPK Signaling Pathway

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Ling Tao ◽  
Yi Liu ◽  
Chao Xin ◽  
Weidong Huang ◽  
Lijian Zhang ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Glucose Uptake ◽  
Fatty Acid Oxidation ◽  
Glucose Utilization ◽  
C2c12 Cells ◽  
Time Dependent ◽  
Acid Oxidation ◽  
Ampk Signaling

FNDC5 is a hormone secreted by myocytes that could reduce obesity and insulin resistance, However, the exact effect of FNDC5 on glucose and lipid metabolism remain poorly identified; More importantly, the signaling pathways that mediate the metabolic effects of FNDC5 is completely unknown. Here we showed that FNDC5 stimulates β-oxidation and glucose uptake in C2C12 cells in a dose- and time-dependent fashion in vitro (n=8, all P<0.01). In vivo study revealed that FNDC5 also enhanced glucose tolerance in diabetic mice and increased the glucose uptake evidenced by increased [18F] FDG accumulation in hearts by PET scan (n=6, all P<0.05). FNDC5 decreased the expression of gluconeogenesis related molecules (PEPCK and G6Pase) and increased the phosphorylation of ACC, a key modulator of fatty-acid oxidation, both in hepatocytes and C2C12 cells (n=3, all P<0.05). In parallel with its stimulation of β-oxidation and glucose uptake, FNDC5 increased the phosphorylation of AMPK both in hepatocytes and C2C12 cells in a dose- and time-dependent fashion in vitro and in vivo. More importantly, the β-oxidation and glucose uptake, the expression of PEPCK and G6Pase and the phosphorylation of ACC induced by FNDC5 were attenuated by AMPK inhibitor in hepatocytes and C2C12 cells (P<0.05). Most importantly, the FNDC5 induced glucose uptake and phosphorylation of ACC were attenuated in AMPK-DN mice (n=6, all P<0.05). The glucose-lowering effect of FNDC5 in diabetic mice was also attenuated by AMPK inhibitor. Our data presents the direct evidence that FNDC5 stimulates glucose utilization and fatty-acid oxidation by AMPK signaling pathway, suggesting that FNDC5 be a novel pharmacological approach for type 2 diabetes.

scholarly journals Crosstalk between the AMP-activated kinase and insulin signaling pathways rescues murine blastocyst cells from insulin resistance

Reproduction ◽  
2008 ◽  
Vol 136 (3) ◽  
pp. 335-344 ◽  
Author(s):  
Erica Louden ◽  
Maggie M Chi ◽  
Kelle H Moley
Keyword(s):  
Insulin Resistance ◽  
Signaling Pathways ◽  
Insulin Signaling ◽  
Kinase Activity ◽  
Pi3 Kinase ◽  
Ampk Activation ◽  
Embryonic Cells ◽  
Insulin Resistant

Maternal insulin resistance results in poor pregnancy outcomes. In vivo and in vitro exposure of the murine blastocyst to high insulin or IGF1 results in the down-regulation of the IGF1 receptor (IGF1R). This in turn leads to decreased glucose uptake, increased apoptosis, as well as pregnancy resorption and growth restriction. Recent studies have shown that blastocyst activation of AMP-activated protein kinase (AMPK) reverses these detrimental effects; however, the mechanism was not clear. The objective of this study was to determine how AMPK activation rescues the insulin-resistant blastocyst. Using trophoblast stem (TS) cells derived from the blastocyst, insulin resistance was recreated by transfecting with siRNA to Igf1r and down-regulating expression of the protein. These cells were then exposed to AMPK activators 5-aminoimidazole-4-carboxamide riboside and phenformin, and evaluated for apoptosis, insulin-stimulated 2-deoxyglucose uptake, PI3-kinase activity, and levels of phospho-AKT, phospho-mTor, and phospho-70S6K. Surprisingly, disrupted insulin signaling led to decreased AMPK activity in TS cells. Activators reversed these effects by increasing the AMP/ATP ratio. Moreover, this treatment increased insulin-stimulated 2-deoxyglucose transport and cell survival, and led to an increase in PI3-kinase activity, as well as increased P-mTOR and p70S6K levels. This study is the first to demonstrate significant crosstalk between the AMPK and insulin signaling pathways in embryonic cells, specifically the enhanced response of PI3K/AKT/mTOR to AMPK activation. Decreased insulin signaling also resulted in decreased AMPK activation. These findings provide mechanistic targets in the AMPK signaling pathway that may be essential for improved pregnancy success in insulin-resistant states.

Abstract 630: Novel Chimeric Anti-proteoglycan Antibody Inhibits Arterial Retention of Proatherogenic Lipoproteins in a Rat Model of Insulin Resistance

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Yosdel Soto ◽  
Rabban Mangat ◽  
Ana M Vázquez ◽  
Spencer D Proctor
Keyword(s):  
Insulin Resistance ◽  
Monoclonal Antibody ◽  
Ex Vivo ◽  
Dependent Manner ◽  
Insulin Resistant ◽  
Remnant Lipoproteins ◽  
Preferential Binding ◽  
Carotid Vessels

Background: The response-to-retention hypothesis for atherosclerosis describes subendothelial retention of apolipoprotein B-containing lipoproteins mediated by proteoglycans (PG). Further we know that diabetes is also associated with both increased circulating chylomicron remnants and remodeling of proatherogenic PGs. We have recently reported antiatherogenic properties of a novel chimeric monoclonal antibody (chP3R99) that recognizes PG sulfated molecules. Hypothesis: chP3R99 monoclonal antibody may interfere with the interaction of atherogenic lipoproteins with arterial sulfated PGs during insulin resistance. Methods and Results: chP3R99 antibody recognized sulfated glycosaminoglycans by ELISA showing a preferential binding to chondroitin sulfate. Also, chP3R99 blocked the interaction of proatherogenic lipoproteins with this glycosaminoglycan in vitro in a dose-dependent manner and its intravenous injection into healthy Sprague-Dawly rats (n=6, 1 mg/animal) inhibited LDL (4 mg/kg; intraperitoneally) aortic retention. To further assess this property in an insulin resistant condition, carotid arteries from control and JCR:LA-cp rats (n=4) were perfused ex vivo with apoB48 containing remnant lipoproteins (prepared via rabbit hepatectomy procedure), with or without Cy3-LDL (150 μg/mL) for 20 minutes. Confocal microscopy analysis revealed an increased arterial retention of both remnants (3.6 fold) and LDL (2.8 fold) in carotid vessels from insulin resistant rats relative to control. However, chP3R99 pre-perfusion resulted in decreased retention of remnants (-30%) and LDL (-60%) associated arterial cholesterol. Data suggests that the chP399 antibody may interfere with the arterial attachment of both remnants and LDL in vivo, but with differential efficacy. Conclusions: Relative to LDL, remnant lipoproteins had preferential accumulation in arterial vessels from insulin resistant rats ex vivo , which could then be inhibited by acute pre-exposure to the chP3R99 antibody. These in vivo data support the concept for an innovative approach to target the retention of proatherogenic lipoproteins in a pre-clinical setting.

scholarly journals Insulin Regulates Glucagon-Like Peptide-1 Secretion from the Enteroendocrine L Cell

Endocrinology ◽  
2009 ◽  
Vol 150 (2) ◽  
pp. 580-591 ◽  
Author(s):  
Gareth E. Lim ◽  
Guan J. Huang ◽  
Nina Flora ◽  
Derek LeRoith ◽  
Christopher J. Rhodes ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Oral Glucose ◽  
Phosphatidylinositol 3 Kinase ◽  
Insulin Resistant ◽  
L Cell ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1 ◽  
Phosphatidylinositol 3

Insulin resistance and type 2 diabetes mellitus are associated with impaired postprandial secretion of glucagon-like peptide-1 (GLP-1), a potent insulinotropic hormone. The direct effects of insulin and insulin resistance on the L cell are unknown. We therefore hypothesized that the L cell is responsive to insulin and that insulin resistance impairs GLP-1 secretion. The effects of insulin and insulin resistance were examined in well-characterized L cell models: murine GLUTag, human NCI-H716, and fetal rat intestinal cells. MKR mice, a model of chronic hyperinsulinemia, were used to assess the function of the L cell in vivo. In all cells, insulin activated the phosphatidylinositol 3 kinase-Akt and MAPK kinase (MEK)-ERK1/2 pathways and stimulated GLP-1 secretion by up to 275 ± 58%. Insulin resistance was induced by 24 h pretreatment with 10−7m insulin, causing a marked reduction in activation of Akt and ERK1/2. Furthermore, both insulin-induced GLP-1 release and secretion in response to glucose-dependent insulinotropic peptide and phorbol-12-myristate-13-acetate were significantly attenuated. Whereas inhibition of phosphatidylinositol 3 kinase with LY294002 potentiated insulin-induced GLP-1 release, secretion was abrogated by inhibiting the MEK-ERK1/2 pathway with PD98059 or by overexpression of a kinase-dead MEK1-ERK2 fusion protein. Compared with controls, MKR mice were insulin resistant and displayed significantly higher fasting plasma insulin levels. Furthermore, they had significantly higher basal GLP-1 levels but displayed impaired GLP-1 secretion after an oral glucose challenge. These findings indicate that the intestinal L cell is responsive to insulin and that insulin resistance in vitro and in vivo is associated with impaired GLP-1 secretion. Insulin is a novel secretagogue of the incretin hormone, glucagon-like peptide-1 (GLP-1), and L cell insulin resistance impairs heterologous secretagogue-induced GLP-1 secretion in vitro and in vivo.

scholarly journals Transcriptional Repression of the VC2105 Protein by Vibrio FadR Suggests that It Is a New Auxiliary Member of thefadRegulon

2016 ◽  
Vol 82 (9) ◽  
pp. 2819-2832 ◽  
Author(s):  
Rongsui Gao ◽  
Jingxia Lin ◽  
Han Zhang ◽  
Youjun Feng
Keyword(s):  
Transcriptional Regulation ◽  
Fatty Acid ◽  
Ligand Binding ◽  
Binding Site ◽  
Binding Sites ◽  
Regulatory Proteins ◽  
Content Type ◽  
Ligand Binding Sites

ABSTRACTRecently, our group along with others reported that theVibrioFadR regulatory protein is unusual in that, unlike the prototypicalfadRproduct ofEscherichia coli, which has only one ligand-binding site,VibrioFadR has two ligand-binding sites and represents a new mechanism for fatty acid sensing. The promoter region of thevc2105gene, encoding a putative thioesterase, was mapped, and a putative FadR-binding site (AA CTG GTA AGA GCA CTT) was proposed. Different versions of the FadR regulatory proteins were prepared and purified to homogeneity. Both electrophoretic mobility shift assay (EMSA) and surface plasmon resonance (SPR) determined the direct interaction of thevc2105gene with FadR proteins of various origins. Further, EMSAs illustrated that the addition of long-chain acyl-coenzyme A (CoA) species efficiently dissociates thevc2105promoter from the FadR regulator. The expression level of theVibrio cholerae vc2105gene was elevated 2- to 3-fold in afadRnull mutant strain, validating that FadR is a repressor for thevc2105gene. The β-galactosidase activity of avc2105-lacZtranscriptional fusion was increased over 2-fold upon supplementation of growth medium with oleic acid. Unlike thefadDgene, a member of theVibrio fadregulon, the VC2105 protein played no role in bacterial growth and virulence-associated gene expression ofctxAB(cholera toxin A/B) andtcpA(toxin coregulated pilus A). Given that the transcriptional regulation ofvc2105fits the criteria for fatty acid degradation (fad) genes, we suggested that it is a new member of theVibrio fadregulon.IMPORTANCETheVibrioFadR regulator is unusual in that it has two ligand-binding sites. Different versions of the FadR regulatory proteins were prepared and characterizedin vitroandin vivo. An auxiliaryfadgene (vc2105) fromVibriowas proposed that encodes a putative thioesterase and has a predicted FadR-binding site (AAC TGG TA A GAG CAC TT). The function of this putative binding site was proved using both EMSA and SPR. Furtherin vitroandin vivoexperiments revealed that theVibrioFadR is a repressor for thevc2105gene. UnlikefadD, a member of theVibrio fadregulon, VC2105 played no role in bacterial growth and expression of the two virulence-associated genes (ctxABandtcpA). Therefore, since transcriptional regulation ofvc2105fits the criteria forfadgenes, it seems likely thatvc2105acts as a new auxiliary member of theVibrio fadregulon.

scholarly journals AMPK Enhances Insulin-Stimulated GLUT4 Regulation via Lowering Membrane Cholesterol

Endocrinology ◽  
2012 ◽  
Vol 153 (5) ◽  
pp. 2130-2141 ◽  
Author(s):  
Kirk M. Habegger ◽  
Nolan J. Hoffman ◽  
Colin M. Ridenour ◽  
Joseph T. Brozinick ◽  
Jeffrey S. Elmendorf
Keyword(s):  
Insulin Resistance ◽  
Cholesterol Synthesis ◽  
Glucose Transporter ◽  
Zucker Rats ◽  
Membrane Cholesterol ◽  
Filamentous Actin ◽  
Cholesterol Lowering ◽  
Insulin Resistant

AMP-activated protein kinase (AMPK) enhances glucose transporter GLUT4 regulation. AMPK also suppresses energy-consuming pathways such as cholesterol synthesis. Interestingly, recent in vitro and in vivo data suggest that excess membrane cholesterol impairs GLUT4 regulation. Therefore, this study tested whether a beneficial, GLUT4-regulatory aspect of AMPK stimulation involved cholesterol lowering. Using L6 myotubes stably expressing an exofacial myc-epitope-tagged-GLUT4, AMPK stimulation by 5-aminoimidazole-4-carboxamide-1-β-d-ribonucleoside (AICAR; 45 min, 1 mm) or 2,4-dinitrophenol (DNP; 30 min, 200 μm) increased cell surface GLUT4myc labeling by approximately ∼25% (P &lt; 0.05). Insulin (20 min, 100 nm) also increased GLUT4myc labeling by about 50% (P &lt; 0.05), which was further enhanced (∼25%, P &lt; 0.05) by AICAR or DNP. Consistent with AMPK-mediated suppression of cholesterol synthesis, AICAR and DNP decreased membrane cholesterol by 20–25% (P &lt; 0.05). Whereas AMPK knockdown prevented the enhanced basal and insulin-stimulated GLUT4myc labeling by AICAR and DNP, cholesterol replenishment only blocked the AMPK-associated enhancement in insulin action. Cells cultured in a hyperinsulinemic milieu, resembling conditions in vivo that promote the progression/worsening of insulin resistance, displayed an increase in membrane cholesterol. This occurred concomitantly with a loss of cortical filamentous actin (F-actin) and defects in GLUT4 regulation by insulin. These derangements were prevented by AMPK stimulation. Examination of skeletal muscle from insulin-resistant Zucker rats revealed a similar elevation in membrane cholesterol and loss of F-actin. Lowering cholesterol to control levels restored F-actin structure and insulin sensitivity. In conclusion, these data suggest a novel aspect of GLUT4 regulation by AMPK involves membrane cholesterol lowering. Moreover, this AMPK-mediated process protected against hyperinsulinemia-induced insulin resistance.

scholarly journals Fermented Antler Improves Endurance during Exercise Performance by Increasing Mitochondrial Biogenesis and Muscle Strength in Mice

2021 ◽  
Vol 11 (12) ◽  
pp. 5386
Author(s):  
Seongeun Jung ◽  
Sung-Hwan Kim ◽  
Woonhee Jeung ◽  
Jehyun Ra ◽  
Keon Heo ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Mitochondrial Biogenesis ◽  
Exercise Performance ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Central Research Institute ◽  
C2c12 Cells ◽  
Central Research

In this study, we investigated whether antler fermented with lactic acid bacteria (LAB) increases mitochondrial biogenesis and muscle strength in vitro and in vivo. LAB from a strain library were grown in antler extract agar at the Yakult Central Research Institute of Korea. Isolated LAB, named Lactobacillus curvatus HY7602, were used to ferment antlers. Analysis of the effects of fermented antler (FA) revealed that it enhanced the insulin-like growth factor 1 (IGF-I), signaling pathway and mitochondrial metabolic activity in mouse skeletal myotube (C2C12) cells. Next, we evaluated the effect of non-fermented antler (NFA) and FA on exercise performance in C57BL/6J mice. The results showed that HY7602-FA increased treadmill exercise capacity and forced swimming endurance. Furthermore, blood markers associated with muscle fatigue, endurance, and energy supply (e.g., alanine aminotransferase, lactate dehydrogenase, creatinine, creatine kinase, and lactate) in the FA-intake group were lower than in the NFA-intake group. In addition, the expression index of genes associated with muscle protein synthesis, and with mitochondrial energy production and supply, in muscle tissue was remarkably higher in the FA group than in the control and NFA groups. Taken together, these results suggested that HY7602-FA may be an effective functional food and health supplement.

Amylin-insulin relationships in insulin resistance with and without diabetic hyperglycemia

1993 ◽  
Vol 265 (3) ◽  
pp. E446-E453 ◽  
Author(s):  
T. R. Pieber ◽  
D. T. Stein ◽  
A. Ogawa ◽  
T. Alam ◽  
M. Ohneda ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Insulin Dependent Diabetes Mellitus ◽  
Male Rats ◽  
In Vivo Studies ◽  
Dependent Diabetes Mellitus ◽  
Ru 486 ◽  
Insulin Resistant ◽  
Insulin Dependent

To determine if increased secretion of amylin can be implicated in the pathogenesis of non-insulin-dependent diabetes mellitus (NIDDM) in vitro and in vivo, we studied its relationships to insulin in insulin-resistant rats with and without NIDDM. In obesity-associated and dexamethasone-induced insulin resistance without diabetes, basal and stimulated secretion of amylin and insulin by isolated pancreata were proportionately elevated, leaving the amylin-to-insulin ratio (A/I) unchanged. By contrast, whenever diabetes occurred in dexamethasone-treated rats or in spontaneously diabetic obese insulin-resistant ZDF-drt male rats, a doubling of A/I was invariably observed due to an increase in amylin without a proportional increase in insulin secretion. Correction of dexamethasone-induced hyperglycemia with the glucocorticord receptor antagonist RU-486 was accompanied by a decline in A/I. Longitudinal in vivo studies demonstrated in both spontaneous and dexamethasone-induced models of NIDDM an increase in plasma A/I at the onset of hyperglycemia. In dexamethasone-induced diabetes, the increased A/I was associated with a high proamylin mRNA relative to proinsulin mRNA. We conclude that amylin and insulin expression and secretion rise in concert in compensated insulin-resistant states, but when hyperglycemia is present the increase in amylin exceeds that of insulin. Although a role of an increased A/I in the pathogenesis of NIDDM has not been established directly, these studies indicate that such a role could be possible.

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