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Neuromuscular Disorders : NMD Apr 2022Phosphofructokinase deficiency (PFKD) is a rare disorder of glycogen metabolism. The lack of phosphofructokinase activity blocks the oxidative pathway from glucose and... (Randomized Controlled Trial)
Randomized Controlled Trial
Phosphofructokinase deficiency (PFKD) is a rare disorder of glycogen metabolism. The lack of phosphofructokinase activity blocks the oxidative pathway from glucose and glycogen to pyruvate. Patients suffer from myopathy, exercise intolerance, and myoglobinuria. Currently, there is no specific treatment for PFKD. We hypothesized that 2 weeks treatment with triheptanoin could improve oxidative metabolism during exercise by bypassing the blocked pyruvate generation in PFKD. The study was a randomized, double-blind, placebo-controlled crossover study. Three genetically verified patients completed two treatment periods of 14 days each with triheptanoin (0.3-1 g × kg × day) or placebo liquid. Primary outcomes were heart rate, fatty acid and total oxidation measured via stable isotope and indirect calorimetry methodology during submaximal exercise. Triheptanoin did not improve the primary outcome heart rate during submaximal exercise compared to placebo. Palmitate oxidation was increased during submaximal exercise in one patient but did not increase in the two other patients during triheptanoin treatment. Palmitate production and palmitate utilization increased during exercise and increased to a greater extent with triheptanoin treatment in all three patients. This study suggests that triheptanoin treatment has no effect on heart rate or exercise performance despite increased palmitate production and utilization in patients with PFKD.
Topics: Cross-Over Studies; Glycogen; Humans; Palmitates; Phosphofructokinases; Pyruvates; Triglycerides
PubMed: 35241345
DOI: 10.1016/j.nmd.2022.01.012 -
Science Translational Medicine Aug 2020The coordination of metabolic signals among different cellular components in pathological retinal angiogenesis is poorly understood. Here, we showed that in the...
The coordination of metabolic signals among different cellular components in pathological retinal angiogenesis is poorly understood. Here, we showed that in the pathological angiogenic vascular niche, retinal myeloid cells, particularly macrophages/microglia that are spatially adjacent to endothelial cells (ECs), are highly glycolytic. We refer to these macrophages/microglia that exhibit a unique angiogenic phenotype with increased expression of both M1 and M2 markers and enhanced production of both proinflammatory and proangiogenic cytokines as pathological retinal angiogenesis-associated glycolytic macrophages/microglia (PRAGMs). The phenotype of PRAGMs was recapitulated in bone marrow-derived macrophages or retinal microglia stimulated by lactate that was produced by hypoxic retinal ECs. Knockout of 6-phosphofructo-2-kinase/fructose-2, 6-bisphosphatase (; for rodents), a glycolytic activator in myeloid cells, impaired the ability of macrophages/microglia to acquire an angiogenic phenotype, rendering them unable to promote EC proliferation and sprouting and pathological neovascularization in a mouse model of oxygen-induced proliferative retinopathy. Mechanistically, hyperglycolytic macrophages/microglia produced large amount of acetyl-coenzyme A, leading to histone acetylation and PRAGM-related gene induction, thus reprogramming macrophages/microglia into an angiogenic phenotype. These findings reveal a critical role of glycolytic metabolites as initiators of reciprocal activation of macrophages/microglia and ECs in the retinal angiogenic niche and suggest that strategies targeting the metabolic communication between these cell types may be efficacious in the treatment of pathological retinal angiogenesis.
Topics: Animals; Endothelial Cells; Glycolysis; Macrophages; Mice; Mice, Knockout; Phosphofructokinase-2
PubMed: 32759274
DOI: 10.1126/scitranslmed.aay1371 -
ELife Nov 2023Compelling evidence has accumulated on the role of oxidative stress on the endothelial cell (EC) dysfunction in acute coronary syndrome. Unveiling the underlying...
Compelling evidence has accumulated on the role of oxidative stress on the endothelial cell (EC) dysfunction in acute coronary syndrome. Unveiling the underlying metabolic determinants has been hampered by the scarcity of appropriate cell models to address cell-autonomous mechanisms of EC dysfunction. We have generated endothelial cells derived from thrombectomy specimens from patients affected with acute myocardial infarction (AMI) and conducted phenotypical and metabolic characterizations. AMI-derived endothelial cells (AMIECs) display impaired growth, migration, and tubulogenesis. Metabolically, AMIECs displayed augmented ROS and glutathione intracellular content, with a diminished glucose consumption coupled to high lactate production. In AMIECs, while PFKFB3 protein levels of were downregulated, PFKFB4 levels were upregulated, suggesting a shunting of glycolysis towards the pentose phosphate pathway, supported by upregulation of G6PD. Furthermore, the glutaminolytic enzyme GLS was upregulated in AMIECs, providing an explanation for the increase in glutathione content. Finally, AMIECs displayed a significantly higher mitochondrial membrane potential than control ECs, which, together with high ROS levels, suggests a coupled mitochondrial activity. We suggest that high mitochondrial proton coupling underlies the high production of ROS, balanced by PPP- and glutaminolysis-driven synthesis of glutathione, as a primary, cell-autonomous abnormality driving EC dysfunction in AMI.
Topics: Humans; Reactive Oxygen Species; Endothelial Cells; Metabolic Reprogramming; Oxidative Stress; Glycolysis; Glutathione; Myocardial Infarction; Phosphofructokinase-2
PubMed: 38014932
DOI: 10.7554/eLife.86260 -
Andrology Nov 2022In the testis, spermatocytes and spermatids rely on lactate produced by Sertoli cells (SCs) as energy source. Transforming growth factor-beta 3 (TGF-β3) is one of the...
BACKGROUNDS
In the testis, spermatocytes and spermatids rely on lactate produced by Sertoli cells (SCs) as energy source. Transforming growth factor-beta 3 (TGF-β3) is one of the generally accepted paracrine regulatory factors of SC-created blood-testis barrier (BTB), yet its role in SC glycolysis and lactate production still remains unclear.
OBJECTIVES
To investigate the effect of TGF-β3 on glycolysis and lactate production in SCs and determine the role of lethal giant larvae 2 (Lgl2) and Notch signaling activity during this process.
MATERIALS AND METHODS
Primary cultured rat SCs and TM4 cells were treated with different concentrations of TGF-β3. In some experiments, cells were transfected with siRNA specifically targeting Lgl2 and then treated with TGF-β3 or N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester. Lactate concentration, glucose and glutamine (Gln) consumption in the culture medium, activity of phosphofructokinase (PFK), lactate dehydrogenase (LDH), and glutaminase (Gls), ATP level, oxygen consumption, extracellular acidification, and mitochondrial respiration complex activity were detected using commercial kits. The protein level of Lgl2, LDH, monocarboxylate transporter 4 (MCT4), and activity of Akt, ERK, p38 MAPK, and Notch pathway were detected by Western blot. The stage-specific expression of Jagged1 was examined by immunohistochemistry (IHC) and qPCR after laser capture microdissection. Spermatogenesis in rat testis injected with recombinant Jagged1 (re-Jagged1) was observed by HE staining, and lactate concentration in testis lysate was measured at a different day point after re-Jagged1 treatment.
RESULTS
Significant enhancement of lactate concentration was detected in a culture medium of both primary SCs and TM4 cells treated with TGF-β3 at 3 or 5 ng/ml. Besides, other parameters of glycolysis, that is, glucose and Gln consumption, enzyme activity of PFK, LDH, and Gls displayed different levels of increment in primary SCs and TM4 cells after TGF-β3 treatment. Mitochondria respiration of SCs was shown to decrease in response to TGF-β3. Lgl2, MCT4, activity of ERK, and p38 MAPK were up-regulated, whereas Akt and Notch pathway activity were inhibited by TGF-β3. Silencing of Lgl2 in SCs affected lactate production and attenuated the previous effects of TGF-β3 on SC glycolysis except for Gln consumption, Gls activity, and activity of Akt, ERK, and p38. N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester (DAPT) treatment in SCs antagonized glycolysis suppression caused by Lgl2-silencing. In vivo analysis revealed a stage-specific expression of Jagged1 in contrary with TGF-β3. Activating Notch signaling by re-Jagged1 resulted in restorable hypospermatogenesis and lowered lactate level in rat testis.
CONCLUSION
TGF-β3 induces lactate production in SC through up-regulating Lgl2, which weakened the Notch signaling activity and intensified glycolysis in SCs. Thus, besides the known function of TGF-β3 as the BTB regulator, TGF-β3-Lgl2-Notch may be considered an important pathway controlling SC glycolysis and spermatogenesis.
Topics: Adenosine Triphosphate; Animals; Esters; Glucose; Glutaminase; Glutamine; L-Lactate Dehydrogenase; Lactic Acid; Male; Phosphofructokinases; Proto-Oncogene Proteins c-akt; RNA, Small Interfering; Rats; Sertoli Cells; Transforming Growth Factor beta3; Transforming Growth Factors; p38 Mitogen-Activated Protein Kinases
PubMed: 36057850
DOI: 10.1111/andr.13288 -
Cell Communication and Signaling : CCS Jan 2024The dynamic changes of RNA N6-methyladenosine (mA) during cancer progression participate in various cellular processes. However, less is known about a possible direct...
The dynamic changes of RNA N6-methyladenosine (mA) during cancer progression participate in various cellular processes. However, less is known about a possible direct connection between upstream regulator and mA modification, and therefore affects oncogenic progression. Here, we have identified that a key enzyme in N4-acetylcytidine (ac4C) acetylation NAT10 is highly expressed in human osteosarcoma tissues, and its knockdown enhanced mA contents and significantly suppressed osteosarcoma cell growth, migration and invasion. Further results revealed that NAT10 silence inhibits mRNA stability and translation of mA reader protein YTHDC1, and displayed an increase in glucose uptake, a decrease in lactate production and pyruvate content. YTHDC1 recognizes differential mA sites on key enzymes of glycolysis phosphofructokinase (PFKM) and lactate dehydrogenase A (LDHA) mRNAs, which suppress glycolysis pathway by increasing mRNA stability of them in an mA methylation-dependent manner. YTHDC1 partially abrogated the inhibitory effect caused by NAT10 knockdown in tumor models in vivo, lentiviral overexpression of YTHDC1 partially restored the reduced stability of YTHDC1 caused by lentiviral depleting NAT10 at the cellular level. Altogether, we found ac4C driven RNA mA modification can positively regulate the glycolysis of cancer cells and reveals a previously unrecognized signaling axis of NAT10/ac4C-YTHDC1/mA-LDHA/PFKM in osteosarcoma. Video Abstract.
Topics: Humans; Lactate Dehydrogenase 5; Phosphofructokinases; Acetylation; RNA; Glycolysis; Osteosarcoma; Phosphofructokinase-1, Muscle Type; RNA Splicing Factors; Nerve Tissue Proteins; N-Terminal Acetyltransferases; Cytidine
PubMed: 38233839
DOI: 10.1186/s12964-023-01321-y -
Cell Death and Differentiation Mar 2021Cancer cells undergo complex metabolic alterations. The mechanisms underlying the tuning of cancer metabolism are under active investigation. Here, we identify the...
Cancer cells undergo complex metabolic alterations. The mechanisms underlying the tuning of cancer metabolism are under active investigation. Here, we identify the uncharacterized deubiquitinase JOSD2 as a positive regulator of cancer cell proliferation by displaying comprehensive effects on glucose catabolism. We found that JOSD2 directly controls a metabolic enzyme complex that includes Aldolase A, Phosphofructokinase-1 and Phosphoglycerate dehydrogenase, in vitro and in vivo. Further, JOSD2 expression, but not a catalytically inactive mutant, deubiquitinates and stabilizes the enzyme complex, thereby enhancing their activities and the glycolytic rate. This represents a selective JOSD2 feature that is not shared among other Machado-Joseph disease DUBs or observed in nontransformed cells. JOSD2 deficiency displays cytostatic effects and reduces glycolysis in a broad spectrum of tumor cells of distinct origin and its expression correlates with poor prognosis in non-small cell lung cancer. Overall, our study provides evidence for a previously unknown biological mechanism in which JOSD2 integrates glucose and serine metabolism with potential therapeutic implications.
Topics: Animals; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Proliferation; Endopeptidases; Female; Fructose-Bisphosphate Aldolase; Glucose; Glycolysis; Humans; Lung Neoplasms; Mice; Mice, Nude; Phosphofructokinase-1; Phosphoglycerate Dehydrogenase; Serine; Ubiquitination; Xenograft Model Antitumor Assays
PubMed: 33082514
DOI: 10.1038/s41418-020-00639-1 -
Frontiers in Pharmacology 2022Glycolysis is a complex metabolic process that occurs to convert glucose into pyruvate to produce energy for living cells. Normal cells oxidized pyruvate into adenosine... (Review)
Review
Glycolysis is a complex metabolic process that occurs to convert glucose into pyruvate to produce energy for living cells. Normal cells oxidized pyruvate into adenosine triphosphate and carbon dioxide in the presence of oxygen in mitochondria while cancer cells preferentially metabolize pyruvate to lactate even in the presence of oxygen in order to maintain a slightly acidic micro-environment of PH 6.5 and 6.9, which is beneficial for cancer cell growth and metastasis. Therefore targeting glycolytic signaling pathways provided new strategy for anti-cancer therapy. Natural products are important sources for the treatment of diseases with a variety of pharmacologic activities. Accumulated studies suggested that natural products exhibited remarkable anti-cancer properties both and . Plenty of studies suggested natural products like flavonoids, terpenoids and quinones played anti-cancer properties inhibiting glucose metabolism targets in glycolytic pathways. This study provided an updated overview of natural products controlling glycolytic pathways, which also provide insight into druggable mediators discovery targeting cancer glucose metabolism.
PubMed: 36339566
DOI: 10.3389/fphar.2022.1035882 -
Cell Death & Disease Sep 2023Intracellular Ca signals control several physiological and pathophysiological processes. The main tool to chelate intracellular Ca is intracellular BAPTA (BAPTA),...
Intracellular Ca signals control several physiological and pathophysiological processes. The main tool to chelate intracellular Ca is intracellular BAPTA (BAPTA), usually introduced into cells as a membrane-permeant acetoxymethyl ester (BAPTA-AM). Previously, we demonstrated that BAPTA enhanced apoptosis induced by venetoclax, a BCL-2 antagonist, in diffuse large B-cell lymphoma (DLBCL). This finding implied a novel interplay between intracellular Ca signaling and anti-apoptotic BCL-2 function. Hence, we set out to identify the underlying mechanisms by which BAPTA enhances cell death in B-cell cancers. In this study, we discovered that BAPTA alone induced apoptosis in hematological cancer cell lines that were highly sensitive to S63845, an MCL-1 antagonist. BAPTA provoked a rapid decline in MCL-1-protein levels by inhibiting mTORC1-driven Mcl-1 translation. These events were not a consequence of cell death, as BAX/BAK-deficient cancer cells exhibited similar downregulation of mTORC1 activity and MCL-1-protein levels. Next, we investigated how BAPTA diminished mTORC1 activity and identified its ability to impair glycolysis by directly inhibiting 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3) activity, a previously unknown effect of BAPTA. Notably, these effects were also induced by a BAPTA analog with low affinity for Ca. Consequently, our findings uncover PFKFB3 inhibition as an Ca-independent mechanism through which BAPTA impairs cellular metabolism and ultimately compromises the survival of MCL-1-dependent cancer cells. These findings hold two important implications. Firstly, the direct inhibition of PFKFB3 emerges as a key regulator of mTORC1 activity and a promising target in MCL-1-dependent cancers. Secondly, cellular effects caused by BAPTA are not necessarily related to Ca signaling. Our data support the need for a reassessment of the role of Ca in cellular processes when findings were based on the use of BAPTA.
Topics: Myeloid Cell Leukemia Sequence 1 Protein; Phosphoric Monoester Hydrolases; Egtazic Acid; Phosphofructokinase-2; Neoplasms
PubMed: 37684238
DOI: 10.1038/s41419-023-06120-4 -
Cell Proliferation Jan 2023ER breast cancer (ER BC) is the most common subtype of BC. Recently, CDK4/6 inhibitors combined with aromatase inhibitors have been approved by FDA as the first-line...
BACKGROUND
ER breast cancer (ER BC) is the most common subtype of BC. Recently, CDK4/6 inhibitors combined with aromatase inhibitors have been approved by FDA as the first-line therapy for patients with ER BC, and showed promising therapeutic efficacy in clinical treatment. However, resistance to CDK4/6 inhibitors is frequently observed. A better understanding of the drug resistance mechanism is beneficial to improving therapeutic strategies by identifying optimal combinational treatments.
METHODS
Western blotting, qPCR, flow cytometry and a series of cell experiments were performed to evaluate the phenotype of MCF-7/R cells. RNA sequencing, non-targeted metabolomics, shRNA knockdown and tumour cell-bearing mouse models were used to clarify the drug resistance mechanism.
RESULTS
Here, we found that ER BC cells have shown an adaptive resistance to palbociclib-induced cell cycle arrest by activating an alternative signal pathway, independent of the CDK4/6-RB signal transduction. Continuing treatment of palbociclib evoked cellular senescence of ER BC cells. Subsequently, the senescence-like phenotype promoted stemness of ER BC cells, accompanied by increased chemoresistance and tumour-initiating potential. Based on transcriptome analysis, we found that PFKFB4 played an important role in stemness transformation and drug resistance. A close correlation was determined between PFKFB4 expression by ER BC cells and cell senescence and stemness. Mechanistically, metabolomic profiling revealed that PFKFB4 reprogramed glucose metabolism and promoted cell stemness by enhancing glycolysis. Strikingly, diminishing PFKFB4 levels improved drug sensitivity and overcame chemoresistance during palbociclib treatment in ER BC.
CONCLUSIONS
These findings not only demonstrated the novel mechanism underlying which ER BC cells resisted to palbociclib, but also provided a possible therapeutic strategy in the intervention of ER BC to overcome drug resistance.
Topics: Humans; Animals; Mice; Female; Receptors, Estrogen; Cell Line, Tumor; MCF-7 Cells; Piperazines; Breast Neoplasms; Drug Resistance, Neoplasm; Cyclin-Dependent Kinase 4; Phosphofructokinase-2
PubMed: 36127291
DOI: 10.1111/cpr.13337 -
Journal of Cellular Physiology Aug 2022Hypertension is an important risk factor in the pathogenesis of diastolic dysfunction. Growing evidence indicates that glucose metabolism plays an essential role in...
Hypertension is an important risk factor in the pathogenesis of diastolic dysfunction. Growing evidence indicates that glucose metabolism plays an essential role in diastolic dysfunction. TP53-induced glycolysis and apoptosis regulator (TIGAR) has been shown to regulate glucose metabolism and heart failure (HF). In the present study, we investigated the role of TIGAR in diastolic function and cardiac fibrosis during pressure overload (PO)-induced HF. WT mice subjected to transverse aortic constriction (TAC), a commonly used method to induce diastolic dysfunction, exhibited diastolic dysfunction as evidenced by increased E/A ratio and E/E' ratio when compared to its sham controls. This was accompanied by increased cardiac interstitial fibrosis. In contrast, the knockout of TIGAR attenuated PO-induced diastolic dysfunction and interstitial fibrosis. Mechanistically, the levels of glucose transporter Glut-1, Glut-4, and key glycolytic enzyme phosphofructokinase 1 (PFK-1) were significantly elevated in TIGAR KO subjected to TAC as compared to that of WT mice. Knockout of TIGAR significantly increased fructose 2,6-bisphosphate levels and phosphofructokinase activity in mouse hearts. In addition, PO resulted in a significant increase in perivascular fibrosis and endothelial activation in the WT mice, but not in the TIGAR KO mice. Our present study suggests a necessary role of TIGAR-mediated glucose metabolism in PO-induced cardiac fibrosis and diastolic dysfunction.
Topics: Animals; Apoptosis Regulatory Proteins; Diastole; Disease Models, Animal; Fibrosis; Glucose; Glycolysis; Heart Failure; Mice; Mice, Inbred C57BL; Mice, Knockout; Myocardium; Phosphofructokinases; Phosphoric Monoester Hydrolases
PubMed: 35621078
DOI: 10.1002/jcp.30790