Mitochondrial Glucose Metabolism Research Articles

An endophenotype network strategy uncovers YangXue QingNao Wan suppresses Aβ deposition, improves mitochondrial dysfunction and glucose metabolism

BackgroundAlzheimer's disease (AD), an escalating global health issue, lacks effective treatments due to its complex pathogenesis. YangXue QingNao Wan (YXQNW) is a China Food and Drug Administration (CFDA)- approved TCM formula that has been repurposed in clinical Phase II for the treatment of AD. Identifying YXQNW's active ingredients and their mechanisms is crucial for developing effective AD treatments. PurposeThis study aims to elucidate the anti-AD effects of YXQNW and to explore its potential therapeutic mechanisms employing an endophenotype network strategy. MethodsHerein we present an endophenotype network strategy that combines active ingredient identification in rat serum, network proximity prediction, metabolomics, and in vivo experimental validation in two animal models. Specially, utilizing UPLC-Q-TOF-MS/MS, active ingredients are identified in YXQNW to build a drug-target network. We applied network proximity to identify potential AD pathological mechanisms of YXQNW via integration of drug-target network, AD endophenotype gene sets, and human protein interactome, and validated related mechanisms in two animal models. In a d-galactose-induced senescent rat model, YXQNW was administered at varying doses for cognitive and neuronal assessments through behavioral tests, Nissl staining, and transmission electron microscopy (TEM). Metabolomic analysis with LC-MS revealed YXQNW's influence on brain metabolites, suggesting therapeutic pathways. Levels of key proteins and biochemicals were measured by WB and ELISA, providing insights into YXQNW's neuroprotective mechanisms. In addition, 5×FAD model mice were used and administered YXQNW by gavage for 14 days at two doses. Amyloid-β levels, transporter expression, and cerebral blood flow have been detected by MRI and biochemical assays. ResultsThe network proximity analysis showed that the effect of YXQNW on AD was highly correlated with amyloid β, synaptic function, glucose metabolism and mitochondrial function. The results of metabolomics combined with in vivo experimental validation suggest that YXQNW has the potential to ameliorate glucose transport abnormalities in the brain by upregulating the expression of GLUT1 and GLUT3, while further enhancing glucose metabolism through increased O-GlcNAcylation and mitigating mitochondrial dysfunction via the AMPK/Sirt1 pathway, thereby improving d-galactose-induced cognitive deficits in rats. Additionally, YXQNW treatment significantly decreased Aβ1–42 levels and enhanced cerebral blood flow (CBF) in the hippocampus of 5×FAD mice. while mechanistic findings indicated that YXQNW treatment increased the expression of ABCB1, an Aβ transporter, in 5×FAD model mice to promote the clearance of Aβ from the brain and alleviate AD-like symptoms. ConclusionsThis study reveals that YXQNW may mitigate AD by inhibiting Aβ deposition and ameliorating mitochondrial dysfunction and glucose metabolism, thus offering a promising therapeutic approach for AD.

Oxyphylla A exerts antiparkinsonian effects by ameliorating 6-OHDA-induced mitochondrial dysfunction and dyskinesia in vitro and in vivo

Parkinson's disease (PD) poses a formidable challenge in neurology, marked by progressive neuronal loss in the substantia nigra. Despite extensive investigations, understanding PD's pathophysiology remains elusive, with no effective therapeutic intervention identified to alter its course. Oxyphylla A (OPA), a natural compound extracted from Alpinia oxyphylla, exhibits promise in experimental models of various neurodegenerative disorders (ND), notably through novel mechanisms like α-synuclein degradation. The purpose of this investigation was to explore the neuroprotective potential of OPA on 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in PD models, with a focus on mitochondrial functions. Additionally, potential OPA targets for neuroprotection were explored. PC12 cells and C57BL/6 mice were lesioned with 6-OHDA as PD models. Impaired mitochondrial membrane potential (Δψm) was assessed using JC-1 staining. The oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) were also detected to evaluate mitochondrial function and glucose metabolism in PC12 cells. Behavioral analysis and immunohistochemistry were performed to evaluate pathological lesions in the mouse brain. Moreover, bioinformatics tools predicted OPA targets. OPA restored cellular energy metabolism and mitochondrial biogenesis, preserving Δψm in 6-OHDA-induced neuronal damage. Pre-treatment mitigated loss of tyrosine hydroxylase (TH)-positive neurons in the substantia nigra and striatal dopaminergic fibers, restoring dopamine levels and ameliorating motor deficits in PD mice. Mechanistically, OPA may activate PKA/Akt/GSK-3β and CREB/PGC-1α/NRF-1/TFAM signaling cascades. Bioinformatics analysis identified potential OPA targets, including CTNNB1, ESR1, MAPK1, MAPK14, and SRC. OPA, derived from Alpinia oxyphylla, exhibited promising neuroprotective activity against PD through addressing mitochondrial dysfunction, suggesting its potential as a multi-targeted therapeutic for PD.

Age-related increase of CD38 directs osteoclastogenic potential of monocytic myeloid-derived suppressor cells through mitochondrial dysfunction in male mice.

An aged immune system undergoes substantial changes where myelopoiesis dominates within the bone marrow. Monocytic-MDSCs (M-MDSCs) have been found to play an important role in osteoclastogenesis and bone resorption. In this study, we sought to provide a more comprehensive understanding of the osteoclastogenic potential of bone marrow M-MDSCs during normal aging through transcriptomic and metabolic changes. Using young mature and aged mice, detailed immunophenotypic analyses of myeloid cells revealed that the M-MDSCs were not increased in bone marrow, however M-MDSCS were significantly expanded in peripheral tissues. Although aged mice exhibited a similar number of M-MDSCs in bone marrow, these M-MDSCs had significantly higher osteoclastogenic potential and greater demineralization activity. Intriguingly, osteoclast progenitors from aged bone marrow M-MDSCs exhibited greater mitochondrial respiration rate and glucose metabolism. Further, transcriptomic analyses revealed the upregulation of mitochondrial oxidative phosphorylation and glucose metabolism genes. Interestingly, there was 8-fold increase in Cd38 mRNA gene expression, consistent with the Mouse Aging Cell Atlas transcriptomic database, and confirmed by qRT-PCR. CD38 regulates NAD+ availability, and 78c, a small molecule inhibitor of CD38, reduced the mitochondrial oxygen consumption rate and glucose metabolism and inhibited the osteoclastogenic potential of aged mice bone marrow-derived M-MDSCs. These results indicate that the age-related increase in Cd38 expression in M-MDSCs bias the transcriptome of M-MDSCs towards osteoclastogenesis. This enhanced understanding of the mechanistic underpinnings of M-MDSCs and their osteoclastogenesis during aging could lead to new therapeutic approaches for age-related bone loss and promote healthy aging.

Metabolomic profiling analysis reveals the benefits of ginseng berry intake on mitochondrial function and glucose metabolism in the liver of obese mice.

Ginseng berry (GB) has previously been demonstrated to improve systemic insulin resistance and regulate hepatic glucose metabolism and steatosis in mice with diet-induced obesity (DIO). In this study, the role of GB in metabolism was assessed using metabolomics analysis on the total liver metabolites of DIO mice. Metabolomic profiling was performed using capillary electrophoresis time-of-flight mass spectrometry (CE-TOF/MS) of liver tissue from mice on a 12-wk normal chow diet (NC), high-fat diet (HFD), and HFD supplemented with 0.1% GB (HFD + GB). The detected metabolites, its pathways, and functions were analyzed through partial least square discriminant analysis (PLS-DA), the small molecular pathway database (SMPDB), and MetaboAnalyst 5.0. The liver metabolite profiles of NC, HFD, and GB-fed mice (HFD + GB) were highly compartmentalized. Metabolites involved in major liver functions, such as mitochondrial function, gluconeogenesis/glycolysis, fatty acid metabolism, and primary bile acid biosynthesis, showed differences after GB intake. The metabolites that showed significant correlations with fasting blood glucose (FBG), insulin, and homeostatic model assessment for insulin resistance (HOMA-IR) were highly associated with mitochondrial membrane function, energy homeostasis, and glucose metabolism. Ginseng berry intake increased the levels of metabolites involved in mitochondrial membrane function, decreased the levels of metabolites related to glucose metabolism, and was highly correlated with metabolic phenotypes. This study demonstrated that long-term intake of GB changed the metabolite of hepatosteatotic livers in DIO mice, normalizing global liver metabolites involved in mitochondrial function and glucose metabolism and indicating the potential mechanism of GB in ameliorating hyperglycemia in DIO mice.

HGG-52. MULTI-INTEGRIN TARGETING EFFECTIVELY SUPPRESSES DIFFUSE MIDLINE GLIOMA MIGRATION

Abstract Diffuse midline gliomas (DMGs) are aggressive tumors characterized by infiltration into normal midline brain tissue, hindering surgical resection and contributing to overall morbidity and mortality. We established a novel two-step pooled whole genome CRISPR-Migration screen by using serum-free conditions and laminin-dependent cell attachment, mimicking cell migration on brain vasculature scaffolds, a common feature in glioblastoma (GBM). Comparing DMG and GBM primary cell lines (n=5), genes involved in focal adhesion (ITGB1, CRKL, PARVA, PTK2, FERMT2) were identified as significantly restricting migration in all cell lines. Multi-institutional transcriptomic data revealed an association of expression of these focal adhesion genes with survival primarily in K27M-DMG and pediatric high-grade glioma compared to lower-grade brain tumors, and ITGB1 expression increased with glioma grade. Single-cell RNA-seq and spatial transcriptomic data demonstrated higher expression of ITGB1 in OPC-like/Mesenchymal cells associated with leading edge and microvasculature in both K27M-DMG and GBM tumors. Unexpectedly, knockout of ITGB1 (ITGB1-KO), primarily responsible for cell adhesion to laminin, led to the decreased expression of multiple mitochondrial NADH dehydrogenase genes, and reduced levels of glycolysis and oxidative phosphorylation (OXPHOS) activity. Preliminary mechanistic data linked this phenotype to impaired mitochondrial fusion. Orthotopic implantation of control and ITGB1-KO models of H3K27M-DMG and adult GBM in mouse brains revealed two distinct phenotypes: (1) ITGB1-KO reducing proliferation and significantly increasing survival; and (2) ITGB1-KO leading to upregulation of ITGB3 and ITGB5 in vivo without impacting survival. Cilengitide (αvβ3 and αvβ5 inhibitor) ablated migration of all ITGB1-KO models on vitronectin (secreted by pericytes surrounding blood vessels) in vitro. Ongoing combinatorial therapy with an experimental anti-Integrin Beta 1 antibody (AIIB2, CNS delivered) and Cilengitide is underway with promising early results. In summary, multi-integrin inhibition provides a feasible avenue to curb glioma spread in the brain through impaired focal adhesion as well as blunting mitochondrial glucose metabolism.

Disarib, a Specific BCL2 Inhibitor, Induces Apoptosis in Triple-Negative Breast Cancer Cells and Impedes Tumour Progression in Xenografts by Altering Mitochondria-Associated Processes.

Targeted cancer therapy aims to disrupt the functions of proteins that regulate cancer progression, mainly by using small molecule inhibitors (SMIs). SMIs exert their effect by modulating signalling pathways, organelle integrity, chromatin components, and several biosynthetic processes essential for cell division and survival. Antiapoptotic protein BCL2 is highly upregulated in many cancers compared with normal cells, making it an ideal target for cancer therapy. Around 75% of primary breast cancers overexpress BCL2, providing an opportunity to explore BCL2 inhibitors as a therapeutic option. Disarib is an SMI that has been developed as a selective BCL2 inhibitor. Disarib works by disrupting BCL2-BAK interaction and activating intrinsic apoptotic pathways in leukemic cells while sparing normal cells. We investigated the effects of Disarib, a BCL2 specific inhibitor, on breast cancer cells and xenografts. Cytotoxicity and fluorometric assays revealed that Disarib induced cell death by increasing reactive oxygen species and activating intrinsic apoptotic pathways in Triple-Negative Breast Cancer cells (MDA-MB-231 and MDA-MB-468). Disarib also affected the colony-forming properties of these cells. MDA-MB-231- and MDA-MB-468-derived xenografts showed a significant reduction in tumours upon Disarib treatment. Through the transcriptomics approach, we also explored the influence of BCL2 inhibitors on energy metabolism, mitochondrial dynamics, and epithelial-to-mesenchymal transition (EMT). Mitochondrial dynamics and glucose metabolism mainly regulate energy metabolism. The change in energetics regulates tumour growth through epithelial-mesenchymal transition, and angiogenesis. RNA sequencing (RNAseq) analysis revealed that BCL2 inhibitors ABT-199 and Disarib maintain Oxphos levels in MDA-MB-231. However, key glycolytic genes were significantly downregulated. Mitochondrial fission genes were seen to be downregulated both in RNAseq data and semi quantitative real time polymerase chain reaction (qRTPCR) in Disarib-treated TNBC cells and xenografts. Lastly, Disarib inhibited wound healing and epithelial-to-mesenchymal transition. This study showed that Disarib disrupts mitochondrial function, activates the intrinsic apoptotic pathway in breast cancer, and inhibits epithelial-to-mesenchymal transition both in vitro and in vivo. These findings highlight Disarib's potential as a multifaceted therapeutic strategy for patients with Triple-Negative Breast Cancer.

Semaglutide ameliorates cardiac remodeling in male mice by optimizing energy substrate utilization through the Creb5/NR4a1 axis

Semaglutide, a glucagon-like peptide-1 receptor agonist, is clinically used as a glucose-lowering and weight loss medication due to its effects on energy metabolism. In heart failure, energy production is impaired due to altered mitochondrial function and increased glycolysis. However, the impact of semaglutide on cardiomyocyte metabolism under pressure overload remains unclear. Here we demonstrate that semaglutide improves cardiac function and reduces hypertrophy and fibrosis in a mouse model of pressure overload-induced heart failure. Semaglutide preserves mitochondrial structure and function under chronic stress. Metabolomics reveals that semaglutide reduces mitochondrial damage, lipid accumulation, and ATP deficiency by promoting pyruvate entry into the tricarboxylic acid cycle and increasing fatty acid oxidation. Transcriptional analysis shows that semaglutide regulates myocardial energy metabolism through the Creb5/NR4a1 axis in the PI3K/AKT pathway, reducing NR4a1 expression and its translocation to mitochondria. NR4a1 knockdown ameliorates mitochondrial dysfunction and abnormal glucose and lipid metabolism in the heart. These findings suggest that semaglutide may be a therapeutic agent for improving cardiac remodeling by modulating energy metabolism.

Transcriptomic and epigenetic characterization of mucinous adenocarcinoma of the cervix.

e17518 Background: Mucinous adenocarcinoma of the cervix (MAC) is a rare and aggressive histologic subtype of cervical cancer with poorer prognosis than its more common counterparts, usual type endocervical adenocarcinoma (UEA) and squamous cell carcinoma (SCC). MAC is also known to be less responsive to standard chemotherapy and radiation approaches used to treat cervical cancer. In this study, we sought to identify transcriptomic and epigenetic features of MAC that distinguish MAC from UEA and SCC, and to identify features that may contribute to poorer prognosis in MAC compared to UEA and SCC. Methods: Clinical data, gene expression, miRNA expression, and methylation data for 17 MAC, 27 UEA, and 247 SCC from The Cancer Genome Atlas Cervical Cancer Project were obtained and analyzed. Clinical data were compared for the histologic groups using Fisher’s Exact, ANOVA, and Kruskal-Wallis statistics where appropriate. Kaplan-Meier curves were used for survival analyses. Gene expression data was analyzed using DESeq2 for differential expression of mRNA. Pathway enrichment analysis of gene expression data was completed using Qiagen IPA Core Analysis software. Comparative marker selection was used to determine differential expression of miRNA, and differential methylation across histologic subtypes. Analyses were completed both by histology and by disease-progression status. Data across all three platforms were integrated to evaluate for potential explanatory relationships of interest. Results: RNAseq analysis revealed a number of genes differentially expressed in MAC as compared to UEA and SCC. Several of these genes were also found to be differentially expressed in samples from patients with disease progression compared to those without known disease progression including increased expression of PPARGC1A, SLC2A1, and ZNF703 and decreased expression of NR4A3. Analysis also revealed hypomethylation at CpG probe sites mapping to SLC2A1 and decreased expression of miRNAs known to target SLC2A1 and PPARGC1A in MAC tumors . Pathways involving translation regulation, EIF2 signaling, and oxidative phosphorylation were downregulated in MAC whereas pathways involving mitochondrial dysfunction, glucose metabolism, and estrogen receptor signaling were upregulated in MAC. Downregulation of immune and inflammatory response pathways and upregulation of tumor-supporting macrophage activation was seen in MAC tumors with disease progression. Conclusions: We identified novel transcriptomic and epigenetic features and altered pathways in MAC, as well as those features and pathways associated with poorer prognosis in this population. These findings may contribute to further confirmatory research and lead to novel therapeutic strategies for this rare cancer.

RNA-sequencing revisited data shed new light on wooden breast myopathy

Wooden Breast (WB) abnormality represents one of the major challenges that the poultry industry has faced in the last 10 years. Despite the enormous progress in understanding the mechanisms underlying WB, the precise initial causes remain to be clarified. In this scenario, the present research is intended to characterize the gene expression profiles of broiler Pectoralis major muscles affected by WB, comparing them to the unaffected counterpart, to provide new insights into the biological mechanisms underlying this defect and potentially identifying novel genes likely involved in its occurrence. To this purpose, data obtained in a previous study through the RNA-sequencing technology have been used to identify differentially expressed genes (DEGs) between 6 affected and 5 unaffected broilers' breast muscles, by using the newest reference genome assembly for Gallus gallus (GRCg7b). Also, to deeply investigate molecular and biological pathways involved in the WB progression, pathways analyses have been performed. The results achieved through the differential gene expression analysis mainly evidenced the downregulation of glycogen metabolic processes, gluconeogenesis, and tricarboxylic acid cycle in WB muscles, thus corroborating the evidence of a dysregulated energy metabolism characterizing breasts affected by this abnormality. Also, genes related to hypertrophic muscle growth have been identified as differentially expressed (e.g., WFIKKN1). Together with that, a downregulation of genes involved in mitochondrial biogenesis and functionality has been detected. Among them, PPARGC1A and PPARGC1B chicken genes are particularly noteworthy. These genes not only have essential roles in regulating mitochondrial biogenesis but also play pivotal roles in maintaining glucose and energy homeostasis. In view of that, their downregulation in WB-affected muscle may be considered as potentially related to both the mitochondrial dysfunction and altered glucose metabolism in WB muscles, and their key involvement in the molecular alterations characterizing this muscular abnormality might be hypothesized.

BET inhibition induces GDH1-dependent glutamine metabolic remodeling and vulnerability in liver cancer

Abstract Bromodomain and extra-terminal domain (BET) proteins, which function partly through MYC proto-oncogene (MYC), are critical epigenetic readers and emerging therapeutic targets in cancer. Whether and how BET inhibition simultaneously induces metabolic remodeling in cancer cells remains unclear. Here we find that even transient BET inhibition by JQ-1 and other pan-BET inhibitors (pan-BETis) blunts liver cancer cell proliferation and tumor growth. BET inhibition decreases glycolytic gene expression but enhances mitochondrial glucose and glutamine oxidative metabolism revealed by metabolomics and isotope labeling analysis. Specifically, BET inhibition downregulates miR-30a to upregulate glutamate dehydrogenase 1 (GDH1) independent of MYC, which produces α-ketoglutarate for mitochondrial oxidative phosphorylation (OXPHOS). Targeting GDH1 or OXPHOS is synthetic lethal to BET inhibition, and combined BET and OXPHOS inhibition therapeutically prevents liver tumor growth in vitro and in vivo. Together, we uncover an important epigenetic-metabolic crosstalk whereby BET inhibition induces MYC-independent and GDH1-dependent glutamine metabolic remodeling that can be exploited for innovative combination therapy of liver cancer.

A comparative transcriptomics analysis reveals ethylene glycol derivatives of squalene ameliorate excessive lipogenesis and inflammatory response in 3T3-L1 preadipocytes

Squalene (SQ) is a natural compound with anti-inflammatory, anti-cancer, and anti-oxidant effects, but due to its low solubility, its biological properties have been greatly underestimated. This study aims to explore the differences in gene expression patterns of four newly synthesized amphipathic ethylene glycol (EG) derivatives of SQ by whole-genome transcriptomics analysis using DNA microarray to examine the mRNA expression profile of adipocytes differentiated from 3T3-L1 cells treated with SQ and its EG derivatives. Enrichment analyses of the transcriptional data showed that compared with SQ, its EG derivatives exerted different, in most cases desirable, biological responses. EG derivatives showed increased enrichment of mitochondrial functions, lipid and glucose metabolism, and inflammatory response. Mono-, di-, and tetra-SQ showed higher enrichment of the cellular component-ribosome. Histological staining showed EG derivatives prevented excessive lipid accumulation. Additionally, mitochondrial transcription factors showed upregulation in tetra-SQ-treated cells. Notably, EG derivatives showed better anti-inflammatory effects. Further, gene-disease association analysis predicted substantial improvement in the bioactivities of SQ derivatives in metabolic diseases. Cluster analyses revealed di- and tetra-SQ had more functional similarities than others, reflected in their scanning electron microscopy images; both di- and tetra-SQ self-organized into similar sizes and shapes of vesicles, subsequently improving their cation binding activities. Protein-protein interaction networks further revealed that cation binding activity might explain a major part, if not all, of the differences observed in functional analyses. Altogether, the addition of EG derivatives may improve the biological responses of SQ and thus may enhance its health-promoting potential.

Deficits in mitochondrial function and glucose metabolism seen in sporadic and familial Alzheimer’s disease derived Astrocytes are ameliorated by increasing hexokinase 1

AbstractBackgroundAstrocytes have multiple roles including providing neurons with metabolic substrates and maintaining neurotransmitters at neuronal synapses. Astrocyte glucose metabolism plays a key role in learning and memory with astrocytic glycogen a key substrate supporting memory encoding. The homeostatic role the astrocyte provides for neurons leads to metabolic demands, meaning that abnormalities in the function of astrocyte mitochondria and glycolysis could affect this relationship. Changes to cellular metabolism are seen early in Alzheimer’s disease (AD). Understanding cellular metabolism changes in AD astrocytes could be exploited as a new biomarker or synergistic therapeutic agent when combined with anti‐amyloid treatments in AD.MethodsIn this project, we characterised mitochondrial and glycolytic dysfunction in astrocytes derived from patients with sporadic (n = 6) and familial (PSEN1, n = 3) AD, and associated controls (n = 9). Astrocytes were derived using direct reprogramming technology. Astrocyte metabolic outputs; ATP, and extracellular lactate levels were measured using luminescent and fluorescent protocols. Mitochondrial respiration and glycolytic function were measured using a Seahorse XF Analyzer. Hexokinase deficits identified where corrected by transfecting astrocytes with an adenovirus viral vector containing the hexokinase 1 gene.ResultsIn sAD astrocytes a 20% reduction (p = 0.05) and in fAD a 48% (p<0.01) reduction in total cellular ATP was seen. A 44% reduction (p<0.05), and 80% reduction in Mitochondrial spare capacity was seen in sAD and fAD respectively. Reactive oxygen species (ROS) where increased in both AD astrocyte types (p = 0.05). Mitochondrial complex I and II was significantly increased in sAD (p<0.05) but not in fAD. Astrocyte glycolytic reserve and extracellular lactate was significantly reduced when compared to controls in both sAD and fAD (p<0.05). We identified that astrocytes had a deficit in the glycolytic pathway enzyme hexokinase, and that correcting this deficit restored total cellular ATP levels, extracellular lactate and reduced ROS in sAD but not fAD astrocytes.ConclusionAD astrocytes have abnormalities in functional capacity of mitochondria and the process of glycolysis. These deficits are likely to impede metabolic support for neurons. These functional deficits can be improved by correcting hexokinase deficits. This suggests that hexokinase 1 deficiency could potentially be exploited as a new therapeutic target for AD.

A commentary: Role of MTA1: a novel modulator reprogramming mitochondrial glucose metabolism

A commentary: Role of MTA1: a novel modulator reprogramming mitochondrial glucose metabolism

Sustained Increases in Cardiomyocyte Protein O-Linked β-N-Acetylglucosamine Levels Lead to Cardiac Hypertrophy and Reduced Mitochondrial Function Without Systolic Contractile Impairment.

Background Lifestyle and metabolic diseases influence the severity and pathogenesis of cardiovascular disease through numerous mechanisms, including regulation via posttranslational modifications. A specific posttranslational modification, the addition of O-linked β-N acetylglucosamine (O-GlcNAcylation), has been implicated in molecular mechanisms of both physiological and pathologic adaptations. The current study aimed to test the hypothesis that in cardiomyocytes, sustained protein O-GlcNAcylation contributes to cardiac adaptations, and its progression to pathophysiology. Methods and Results Using a naturally occurring dominant-negative O-GlcNAcase (dnOGA) inducible cardiomyocyte-specific overexpression transgenic mouse model, we induced dnOGA in 8- to 10-week-old mouse hearts. We examined the effects of 2-week and 24-week dnOGA overexpression, which progressed to a 1.8-fold increase in protein O-GlcNAcylation. Two-week increases in protein O-GlcNAc levels did not alter heart weight or function; however, 24-week increases in protein O-GlcNAcylation led to cardiac hypertrophy, mitochondrial dysfunction, fibrosis, and diastolic dysfunction. Interestingly, systolic function was maintained in 24-week dnOGA overexpression, despite several changes in gene expression associated with cardiovascular disease. Specifically, mRNA-sequencing analysis revealed several gene signatures, including reduction of mitochondrial oxidative phosphorylation, fatty acid, and glucose metabolism pathways, and antioxidant response pathways after 24-week dnOGA overexpression. Conclusions This study indicates that moderate increases in cardiomyocyte protein O-GlcNAcylation leads to a differential response with an initial reduction of metabolic pathways (2-week), which leads to cardiac remodeling (24-week). Moreover, the mouse model showed evidence of diastolic dysfunction consistent with a heart failure with preserved ejection fraction. These findings provide insight into the adaptive versus maladaptive responses to increased O-GlcNAcylation in heart.

Abstract P2055: Long-term Elevation Of Cardiomyocyte Protein O-GlcNAc Levels Induces Cardiac Hypertrophy And Reduced Mitochondrial Function With Preserved Systolic Contractility

The severity and development of cardiovascular disease (CVD) can be affected by lifestyle and metabolic diseases, which can impact various mechanisms, including post-translational modifications (PTM). A specific PTM, known as protein O-linked β-N acetylglucosamine modification (O-GlcNAc), has been linked to both physiological responses and pathological progression of heart failure. This study was aimed to test whether sustained cardiac protein O-GlcNAc of proteins in cardiomyocytes contributes to cardiac adaptations or is sufficient to progress toward pathophysiology. Specifically, we generated transgenic mice overexpressing a naturally occurring dominant-negative O-GlcNAcase (dnOGA) in an inducible and cardiomyocyte-specific manner (dnOGAh). We induced dnOGA in male and female 8-10-weeks-old mice and examined the effects of 2-weeks (2wk) and 24-weeks (24wk) dnOGA overexpression, which resulted in a 1.8-fold increase in protein O - GlcNAc levels ( P <0.01). The results showed that a 2wk increase in protein O-GlcNAc levels did not impact heart weight or function; however, 24wk of elevated protein O-GlcNAc led to cardiac hypertrophy (+19.8%, P <0.01), fibrosis (M. Trichrome; +578%, P <0.005), and diastolic dysfunction (E/A; +314%, P <0.001). Despite several changes in gene expression associated with CVD, systolic function was maintained in 24wk dnOGA overexpression. mRNA-seq analysis revealed several gene signatures changed as early as 2wk of dnOGA that progressed at 24wk, including reduction of mitochondrial oxidative phosphorylation, fatty acid and glucose metabolism pathways (

Metabolic reprogramming in osteosarcoma

AbstractTumor cells undergo metabolic reprogramming to meet their energy and anabolic demands to maintain their malignant phenotype. Activation of oncogenes and deletion of tumor suppressors promotes metabolic reprogramming in cancer by directly or indirectly regulating enzymatic activities associated with metabolic pathways. Metabolic reprogramming in tumor cells mainly involves the glycolytic pathway, pentose phosphate pathway, serine synthesis pathway, enhanced glutamine metabolism or fatty acid anabolism, and abnormal mitochondrial oxidative phosphorylation (OXPHOS). The tricarboxylic acid (TCA) cycle is the central pathway of mitochondrial OXPHOS, and glucose, amino acid and fatty acid metabolism are associated with the TCA cycle. Metabolic abnormalities and rewiring of metabolic pathways are also present in Osteosarcoma (OS). The abnormal metabolic pattern in OS is associated with cell proliferation, migration, invasion and drug resistance. This review summarizes the current studies on glycolysis, amino acid metabolism, lipid synthesis and the TCA cycle related to OS.

Correlation between abnormal energy metabolism of ovarian granulosa cells and in vitro fertilization–embryo transfer outcomes in patients with polycystic ovary syndrome and obesity

ContextGranulosa cells (GCs) that surround oocytes in mammalian reproduction play an active role in oocyte differentiation through proliferation and energy production.AimsThis study aimed to investigate the characteristics of the energy metabolism of ovarian GCs and the influence of GCs on the early embryonic development in polycystic ovary syndrome (PCOS).MethodsThe clinical characteristics and in vitro fertilization-embryo transfer treatment outcomes of 39 patients with PCOS and 68 patients with simple tubal factor infertility who underwent controlled ovarian hyperstimulation were analyzed and summarized. The mitochondrial function and glucose metabolism level of the GCs were determined, as well as the content of oxidative stress markers in the follicular fluid (FF) of patients with and without PCOS.Key resultsWhen compared to the non-PCOS group, patients with PCOS had a significantly increased number of retrieved oocytes but a significantly decreased number of high-quality embryos, available embryos, and high-quality blastocyst formation (P < 0.05). Furthermore, the mitochondrial membrane potential, adenosine triphosphate level, and mitochondrial DNA (mtDNA) copy number decreased in the GCs, whereas the levels of reactive oxygen species increased (P < 0.01). The levels of malondialdehyde and 8-oxo-deoxyguanosine (8-OHdG) in the follicular fluid (FF) of the patients with PCOS were higher than those of the control group (P < 0.05), and superoxide dismutase was increased by compensation (P < 0.05). In the PCOS group, the expressions of GLUT1, LDHA, and PFKP were lower than those in the non-PCOS group, and glucose levels were higher.ConclusionsThe low oocyte competence of PCOS may be associated with mitochondrial dysfunction and abnormal glycolysis.ImplicationsThis research offers explanations for the possible connections influencing human ovarian folliculogenesis.

Shengxian decoction protects against chronic heart failure in a rat model via energy regulation mechanisms

BackgroundChronic heart failure (CHF) is actually a disease caused by an imbalanced energy metabolism between myocardial energy demand and supply, ultimately resulting in abnormal myocardial cell structure and function. Energy metabolism imbalance plays an important role in the pathological process of chronic heart failure (CHF). Improving myocardial energy metabolism is a new strategy for the treatment of CHF. Shengxian decoction (SXT), a well-known traditional Chinese medicine (TCM) formula, has good therapeutic effects on the cardiovascular system. However, the effects of SXT on the energy metabolism of CHF is unclear. In this study, we probed the regulating effects of SXT on energy metabolism in CHF rats using various research methods.MethodsHigh-performance liquid chromatography (HPLC) analysis was used to perform quality control of SXT preparations. Then, SD rats were randomly assigned into 6 groups: sham, model, positive control (trimetazidine) and high-, middle-, and low-dose SXT groups. Specific reagent kits were used to detect the expression levels of ALT and AST in rats’ serum. Echocardiography was used to evaluate cardiac function. H&E, Masson and TUNEL staining were performed to examine myocardial structure and myocardial apoptosis. Colorimetry was used to determine myocardial ATP levels in experimental rats. Transmission electron microscopy was used to observe the ultrastructure of myocardial mitochondria. ELISA was used to estimate CK, cTnI, and NT-proBNP levels, and LA、FFA、MDA、SOD levels. Finally, Western blotting was used to examine the protein expression of CPT-1, GLUT4, AMPK, p-AMPK, PGC-1α, NRF1, mtTFA and ATP5D in the myocardium.ResultsHPLC showed that our SXT preparation method was feasible. The results of ALT and AST tests indicate that SXT has no side effect on the liver function of rats. Treatment with SXT improved cardiac function and ventricular remodelling and inhibited cardiomyocyte apoptosis and oxidative stress levels induced by CHF. Moreover, CHF caused decrease ATP synthesis, which was accompanied by a reduction in ATP 5D protein levels, damage to mitochondrial structure, abnormal glucose and lipid metabolism, and changes in the expression of PGC-1α related signal pathway proteins, all of which were significantly alleviated by treatment with SXT.ConclusionSXT reverses CHF-induced cardiac dysfunction and maintains the integrity of myocardial structure by regulating energy metabolism. The beneficial effect of SXT on energy metabolism may be related to regulating the expression of the PGC-1α signalling pathway.

Sp1 promotes tumour progression by remodelling the mitochondrial network in cervical cancer

BackgroundCervical cancer remains one of the most prevalent cancers worldwide. Accumulating evidence suggests that specificity protein 1 (Sp1) plays a pivotal role in tumour progression. The underlying role and mechanism of Sp1 in tumour progression remain unclear.MethodsThe protein level of Sp1 in tumour tissues was determined by immunohistochemistry. The effect of Sp1 expression on the biological characteristics of cervical cancer cells was assessed by colony, wound healing, transwell formation, EdU, and TUNEL assays. Finally, the underlying mechanisms and effects of Sp1 on the mitochondrial network and metabolism of cervical cancer were analysed both in vitro and in vivo.ResultsSp1 expression was upregulated in cervical cancer. Sp1 knockdown suppressed cell proliferation both in vitro and in vivo, while overexpression of Sp1 had the opposite effects. Mechanistically, Sp1 facilitated mitochondrial remodelling by regulating mitofusin 1/2 (Mfn1/2), OPA1 mitochondrial dynamin-like GTPase (Opa1), and dynamin 1-like (Drp1). Additionally, the Sp1-mediated reprogramming of glucose metabolism played a critical role in the progression of cervical cancer cells.ConclusionsOur study demonstrates that Sp1 plays a vital role in cervical tumorigenesis by regulating the mitochondrial network and reprogramming glucose metabolism. Targeting Sp1 could be an effective strategy for the treatment of cervical cancer.

The Role of Genetic Mutations in Mitochondrial-Driven Cancer Growth in Selected Tumors: Breast and Gynecological Malignancies.

There is an increasing understanding of the molecular and cytogenetic background of various tumors that helps us better conceptualize the pathogenesis of specific diseases. Additionally, in many cases, these molecular and cytogenetic alterations have diagnostic, prognostic, and/or therapeutic applications that are heavily used in clinical practice. Given that there is always room for improvement in cancer treatments and in cancer patient management, it is important to discover new therapeutic targets for affected individuals. In this review, we discuss mitochondrial changes in breast and gynecological (endometrial and ovarian) cancers. In addition, we review how the frequently altered genes in these diseases (BRCA1/2, HER2, PTEN, PIK3CA, CTNNB1, RAS, CTNNB1, FGFR, TP53, ARID1A, and TERT) affect the mitochondria, highlighting the possible associated individual therapeutic targets. With this approach, drugs targeting mitochondrial glucose or fatty acid metabolism, reactive oxygen species production, mitochondrial biogenesis, mtDNA transcription, mitophagy, or cell death pathways could provide further tailored treatment.