Abstract 15465: Upregulation of Mitochondrial Atpase Inhibitory Factor 1 Mediates Increased Glycolysis in Pathological Cardiac Hypertrophy

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Bo Zhou ◽  
Arianne Caudal ◽  
Xiaoting Tang ◽  
Juan D Chavez ◽  
Andrew Keller ◽  
...  

Background: During the development of heart failure cardiac fuel metabolism switches from predominantly fatty acid oxidation (FAO) to increased reliance on glucose, especially glycolysis. Mechanisms responsible for the switch are poorly understood but appear to be coupled with impaired mitochondrial function. We recently demonstrated that increased glucose metabolism is required for cardiomyocytes growth during pathological remodeling. Hypothesis: Upregulation of mitochondrial ATPase inhibitory factor 1 (ATPIF1) in hypertrophied hearts suppresses ATP synthesis and shifts cardiac metabolism from fatty acid oxidation towards glucose metabolism. Methods and Results: We report that ATPIF1 expression is upregulated in cardiomyocytes and mouse hearts undergoing pathological hypertrophy. Using genetic models of ATPIF1 gain- and loss-of-function in cardiomyocytes and in mouse hearts,we find that upregulation of ATPIF1 in cardiac hypertrophy inhibits ATP synthesis. Furthermore, quantitative analysis of chemical crosslinking by mass spectrometry revealed that increased expression of ATPIF1 promoted the formation of F o F 1 -ATP synthase nonproductive tetramer. Impairment of F o F 1 -ATP synthase function in respiring mitochondria increasedROS generation resulting in transcriptional activation of glycolysis. Cardiac-specific deletion of ATPIF1 in mice prevented the switch to glycolysis in pressure overload induced cardiac hypertrophy. Conclusions: We show that upregulation of ATPIF1 drives glucose metabolism at the expense of energy supply during the pathological growth of cardiomyocytes. Our study proposes a central role of ATP synthase in toggling anabolic and catabolic metabolism during pathological remodeling, illustrating a new concept for metabolic reprogramming of the heart.

2011 ◽  
Vol 31 (6) ◽  
pp. 1252-1262 ◽  
Author(s):  
J. M. Ellis ◽  
S. M. Mentock ◽  
M. A. DePetrillo ◽  
T. R. Koves ◽  
S. Sen ◽  
...  

2019 ◽  
Vol 33 (12) ◽  
pp. 14825-14840 ◽  
Author(s):  
Hye Jeong Lee ◽  
Jiyoung Moon ◽  
InHyeok Chung ◽  
Ji Hyung Chung ◽  
Chan Park ◽  
...  

1993 ◽  
Vol 265 (4) ◽  
pp. E592-E600 ◽  
Author(s):  
A. B. Jenkins ◽  
L. H. Storlien ◽  
G. J. Cooney ◽  
G. S. Denyer ◽  
I. D. Caterson ◽  
...  

We examined the effect of the long-chain fatty acid oxidation blocker methyl palmoxirate (methyl 2-tetradecyloxiranecarboxylate, McN-3716) on glucose metabolism in conscious rats. Fasted animals [5 h with or without hyperinsulinemia (100 mU/l) and 24 h] received methyl palmoxirate (30 or 100 mg/kg body wt po) or vehicle 30 min before a euglycemic glucose clamp. Whole body and tissue-specific glucose metabolism were calculated from 2-deoxy-[3H]-glucose kinetics and accumulation. Oxidative metabolism was assessed by respiratory gas exchange in 24-h fasted animals. Pyruvate dehydrogenase complex activation was determined in selected tissues. Methyl palmoxirate suppressed whole body lipid oxidation by 40-50% in 24-h fasted animals, whereas carbohydrate oxidation was stimulated 8- to 10-fold. Whole body glucose utilization was not significantly affected by methyl palmoxirate under any conditions; hepatic glucose output was suppressed only in the predominantly gluconeogenic 24-h fasted animals. Methyl palmoxirate stimulated glucose uptake in heart in 24-h fasted animals [15 +/- 5 vs. 220 +/- 28 (SE) mumol x 100 g-1 x min-1], with smaller effects in 5-h fasted animals with or without hyperinsulinemia. Methyl palmoxirate induced significant activation of pyruvate dehydrogenase in heart in the basal state, but not during hyperinsulinemia. In skeletal muscles, methyl palmoxirate suppressed glucose utilization in the basal state but had no effect during hyperinsulinemia; pyruvate dehydrogenase activation in skeletal muscle was not affected by methyl palmoxirate under any conditions. The responses in skeletal muscle are consistent with the operation of a mechanism similar to the Pasteur effect.(ABSTRACT TRUNCATED AT 250 WORDS)


2006 ◽  
Vol 291 (5) ◽  
pp. E1131-E1140 ◽  
Author(s):  
Michael Christopher ◽  
Christian Rantzau ◽  
Zhi-Ping Chen ◽  
Rodney Snow ◽  
Bruce Kemp ◽  
...  

AMPK plays a central role in influencing fuel usage and selection. The aim of this study was to analyze the impact of low-dose AMP analog 5-aminoimidazole-4-carboxamide-1-β-d-ribosyl monophosphate (ZMP) on whole body glucose turnover and skeletal muscle (SkM) glucose metabolism. Dogs were restudied after prior 48-h fatty acid oxidation (FAOX) blockade by methylpalmoxirate (MP; 5 × 12 hourly 10 mg/kg doses). During the basal equilibrium period (0–150 min), fasting dogs ( n = 8) were infused with [3-3H]glucose followed by either 2-h saline or AICAR (1.5–2.0 mg·kg−1·min−1) infusions. SkM was biopsied at completion of each study. On a separate day, the same protocol was undertaken after 48-h in vivo FAOX blockade. The AICAR and AICAR + MP studies were repeated in three chronic alloxan-diabetic dogs. AICAR produced a transient fall in plasma glucose and increase in insulin and a small decline in free fatty acid (FFA). Parallel increases in hepatic glucose production (HGP), glucose disappearance (Rd tissue), and glycolytic flux (GF) occurred, whereas metabolic clearance rate of glucose (MCRg) did not change significantly. Intracellular SkM glucose, glucose 6-phosphate, and glycogen were unchanged. Acetyl-CoA carboxylase (ACC∼pSer221) increased by 50%. In the AICAR + MP studies, the metabolic responses were modified: the glucose was lower over 120 min, only minor changes occurred with insulin and FFA, and HGP and Rd tissue responses were markedly attenuated, but MCRg and GF increased significantly. SkM substrates were unchanged, but ACC∼pSer221 rose by 80%. Thus low-dose AICAR leads to increases in HGP and SkM glucose uptake, which are modified by prior FAox blockade.


1994 ◽  
Vol 267 (5) ◽  
pp. H1862-H1871 ◽  
Author(s):  
R. L. Collins-Nakai ◽  
D. Noseworthy ◽  
G. D. Lopaschuk

Although epinephrine is widely used clinically, its effect on myocardial energy substrate preference in the intact heart has yet to be clearly defined. We determined the effects of epinephrine on glucose and fatty acid metabolism in isolated working rat hearts perfused with 11 mM glucose, 0.4 mM palmitate, and 100 muU/ml insulin at an 11.5-mmHg left atrial preload and a 60-mmHg aortic afterload. Glycolysis and glucose oxidation were measured in hearts perfused with [5–3H]glucose and [U-14C]glucose, whereas fatty acid oxidation was measured in hearts perfused with [1–14C]palmitate. Addition of 1 microM epinephrine resulted in a 53% increase in the heart rate-developed pressure product. Glycolysis increased dramatically following addition of epinephrine (a 272% increase), as did glucose oxidation (a 410% increase). In contrast, fatty acid oxidation increased by only 10%. Epinephrine treatment did not increase the amount of oxygen required to produce an equivalent amount of ATP; however, epinephrine did increase the uncoupling between glycolysis and glucose oxidation in these fatty acid-perfused hearts, resulting in a significant increase in H+ production from glucose metabolism. Overall ATP production in epinephrine-treated hearts increased 59%. The contribution of glucose (glycolysis and glucose oxidation) to ATP production increased from 13 to 36%, which was accompanied by a reciprocal decrease in the contribution of fatty acid oxidation to ATP production from 83 to 63%. The increase in glucose oxidation was accompanied by a significant increase in pyruvate dehydrogenase complex activity in the active form. We conclude that the increase in ATP required for contractile function following epinephrine treatment occurs through a preferential increase in glucose use.


2009 ◽  
Vol 296 (3) ◽  
pp. E497-E502 ◽  
Author(s):  
A. Lombardi ◽  
P. de Lange ◽  
E. Silvestri ◽  
R. A. Busiello ◽  
A. Lanni ◽  
...  

Triiodothyronine regulates energy metabolism and thermogenesis. Among triiodothyronine derivatives, 3,5-diiodo-l-thyronine (T2) has been shown to exert marked effects on energy metabolism by acting mainly at the mitochondrial level. Here we investigated the capacity of T2 to affect both skeletal muscle mitochondrial substrate oxidation and thermogenesis within 1 h after its injection into hypothyroid rats. Administration of T2 induced an increase in mitochondrial oxidation when palmitoyl-CoA (+104%), palmitoylcarnitine (+80%), or succinate (+30%) was used as substrate, but it had no effect when pyruvate was used. T2 was able to 1) activate the AMPK-ACC-malonyl-CoA metabolic signaling pathway known to direct lipid partitioning toward oxidation and 2) increase the importing of fatty acids into the mitochondrion. These results suggest that T2 stimulates mitochondrial fatty acid oxidation by activating several metabolic pathways, such as the fatty acid import/β-oxidation cycle/FADH2-linked respiratory pathways, where fatty acids are imported. T2 also enhanced skeletal muscle mitochondrial thermogenesis by activating pathways involved in the dissipation of the proton-motive force not associated with ATP synthesis (“proton leak”), the effect being dependent on the presence of free fatty acids inside mitochondria. We conclude that skeletal muscle is a target for T2, and we propose that, by activating processes able to enhance mitochondrial fatty acid oxidation and thermogenesis, T2 could play a role in protecting skeletal muscle against excessive intramyocellular lipid storage, possibly allowing it to avoid functional disorders.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3779-3779
Author(s):  
Michael Andreeff ◽  
Michael Fiegl ◽  
Marina Konopleva ◽  
Borys Korchin ◽  
Kumar Kaluarachchi ◽  
...  

Abstract Abstract 3779 Poster Board III-715 Otto Warburg proposed that the origin of cancer cells was closely linked to a permanent respiratory defect that bypassed the Pasteur effect, i.e. the inhibition of anaerobic fermentation by oxygen. We have recently demonstrated in leukemia cells that mitochondrial uncoupling, i.e. the abrogation of ATP synthesis in response to mitochondrial membrane potential (MMP), promotes the Warburg effect, contributes to chemo-resistance and represents a metabolic shift to fatty acid oxidation (FAO). Exposure of leukemic cells to marrow-derived mesenchymal stromal cells (MSC) promotes accumulation of lactate and reduces MMP. Stroma/leukemia co-cultures protect leukemia cells from chemotherapy-induced apoptosis. We found that he decrease in MMP was mediated by mitochondrial uncoupling accompanied by increased expression of mitochondrial uncoupling protein (UCP2) (Cancer Res. 68:5198,2008). We therefore proposed that the Warburg effect may be the result of preferential oxidation of fatty acids in cancer cell mitochondria (Cancer Res.69:2163,2009). Here we demonstrate that leukemia cells uncouple FAO from ATP synthesis, and that pharmacological inhibition of FAO with etomoxir or ranolazine inhibits proliferation and sensitizes leukemia cells – cultured alone or on bone marrow stromal cells – to apoptosis induction by the BH3 mimetic ABT-737 and the MDM-2 antagonist Nutlin 3a. Results suggest that leukemia cells rely, at least in part, on de novo fatty acid synthesis (FAS) to support FAO. Furthermore, treatment with the FAS inhibitor orlistat sensitized leukemia cells to apoptosis induction by ABT-737. Mechanistically, mitochondria derived from etomoxir treated leukemia cells were sensitized to release of cytochrome C and apoptosis-inducing-factor (AIF) upon treatment with ABT-737. Etomoxir (EX) facilitated the formation of Bak oligomers after treatment with ABT-737 suggesting that FAO regulates the activity of Bak-dependent mitochondrial permeability transition. Lastly, we present evidence that EX, in combination with liposomal ABT-737 or cytosine arabinoside (AraC), provides significant therapeutic benefit in a murine model of human leukemia (luciferase/GFP marked MOLT13 cells) as evidenced by reduced in vivo growth kinetics (BLI) and prolonged median survival (ABT-737 vs. EX+ABT-737, p=<0.05; AraC vs.EX+AraC,p<0.0001 ). Conclusions: 1) results support the notion that the Warburg effect may be the result of preferential oxidation of fatty acids by leukemia mitochondria. 2) Inhibition of fatty acid oxidation is proposed as a novel therapeutic concept for hematological malignancies. Disclosures: No relevant conflicts of interest to declare.


2003 ◽  
Vol 284 (5) ◽  
pp. E923-E930 ◽  
Author(s):  
Laura L. Atkinson ◽  
Ray Kozak ◽  
Sandra E. Kelly ◽  
Arzu Onay-Besikci ◽  
James C. Russell ◽  
...  

The accumulation of intracellular triacylglycerol (TG) is highly correlated with muscle insulin resistance. However, it is controversial whether the accumulation of TG is the result of increased fatty acid supply, decreased fatty acid oxidation, or both. Because abnormal fatty acid metabolism is a key contributor to the pathogenesis of diabetes-related cardiovascular dysfunction, we examined fatty acid and glucose metabolism in hearts of insulin-resistant JCR:LA-cp rats. Isolated working hearts from insulin-resistant rats had glycolytic rates that were reduced to 50% of lean control levels ( P < 0.05). Cardiac TG content was increased by 50% ( P < 0.05) in the insulin-resistant rats, but palmitate oxidation rates remained similar between the insulin-resistant and lean control rats. However, plasma fatty acids and TG levels, as well as cardiac fatty acid-binding protein (FABP) expression, were significantly increased in the insulin-resistant rats. AMP-activated protein kinase (AMPK) plays a major role in the regulation of cardiac fatty acid and glucose metabolism. When activated, AMPK increases fatty acid oxidation by inhibiting acetyl-CoA carboxylase (ACC) and reducing malonyl-CoA levels, and it decreases TG content by inhibiting glycerol-3-phosphate acyltransferase (GPAT), the rate-limiting step in TG synthesis. The activation of AMPK also stimulates cardiac glucose uptake and glycolysis. We thus investigated whether a decrease in AMPK activity was responsible for the reduced cardiac glycolysis and increased TG content in the insulin-resistant rats. However, we found no significant difference in AMPK activity. We also found no significant difference in various established downstream targets of AMPK: ACC activity, malonyl-CoA levels, carnitine palmitoyltransferase I activity, or GPAT activity. We conclude that hearts from insulin-resistant JCR:LA-cp rats accumulate substantial TG as a result of increased fatty acid supply rather than from reduced fatty acid oxidation. Furthermore, the accumulation of cardiac TG is associated with a reduction in insulin-stimulated glucose metabolism.


1956 ◽  
Vol 34 (1) ◽  
pp. 1227-1232 ◽  
Author(s):  
P. G. Scholefield

The effects of potassium decanoate on the phosphorylation associated with the oxidation of pyruvate by rat-kidney and rat-brain mitochondria have been investigated. The suggestion that these two processes may be uncoupled from each other in the presence of decanoate has been confirmed. Further, it has been shown that the decanoate-insensitive oxidation of pyruvate by rat-brain mitochondria, occurring in the absence of such stimulating agents as fumarate, is not associated with ATP synthesis. The fumarate-stimulated oxidation of pyruvate by rat-brain mitochondria, which is inhibited by decanoate, is associated with a phosphorylation process which is uncoupled by decanoate. When pyruvate oxidation by rat-kidney or by rat-brain mitochondria is uncoupled from phosphorylation, the extent of uncoupling is proportional to the amount of decanoate added.


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