Cellular Energy Metabolism Research Articles

Respiratory bioenergetics is enhanced in human, but not bovine macrophages after exposure to M. bovis PPD: Exploratory insights into overall similar Cellular Metabolic Profiles.

The role of macrophage (MØ) cellular metabolism and reprogramming during TB infection is of great interest due to the influence of Mycobacterium spp. on MØ bioenergetics. Recent studies have shown that M. tuberculosis induces a TLR2-dependent shift towards aerobic glycolysis, comparable to the established LPS induced pro-inflammatory M1 MØ polarisation. Distinct differences in the metabolic profile of murine and human MØ indicates species-specific differences in bioenergetics. So far, studies examining the metabolic potential of bovine MØ are lacking, thus the basic bioenergetics of bovine and human MØ were explored in response to a variety of innate immune stimuli. Cellular energy metabolism kinetics were measured concurrently for both species on a Seahorse XFe96 platform to generate bioenergetic profiles for the response to the bona-fide TLR2 and TLR4 ligands, FSL-1 and LPS respectively. Despite previous reports of species-specific differences in TLR signalling and cytokine production between human and bovine MØ, we observed similar respiratory profiles for both species. Basal respiration remained constant between stimulated MØ and controls, whereas addition of TLR ligands induced increased glycolysis, as measured by the surrogate parameter ECAR. In contrast to MØ stimulation with M. tuberculosis PPD, another TLR2 ligand, M. bovis PPD treatment significantly enhanced basal respiration rates and glycolysis only in human MØ. Respiratory profiling further revealed significant elevation of ATP-linked OCR and maximal respiration suggesting a strong OXPHOS activation upon M. bovis PPD stimulation in human MØ. Our results provide an exploratory set of data elucidating the basic respiratory profile of bovine vs. human MØ that will not only lay the foundation for future studies to investigate host-tropism of the M. tuberculosis complex but may explain inflammatory differences observed for other zoonotic diseases.

Proinflammatory Cytokines Enhance the Mineralization, Proliferation, and Metabolic Activity of Primary Human Osteoblast-like Cells

Osteoporosis is a progressive metabolic bone disease characterized by decreased bone density and microarchitectural deterioration, leading to an increased risk of fracture, particularly in postmenopausal women and the elderly. Increasing evidence suggests that inflammatory processes play a key role in the pathogenesis of osteoporosis and are strongly associated with the activation of osteoclasts, the cells responsible for bone resorption. In the present study, we investigated, for the first time, the influence of proinflammatory cytokines on the osteogenic differentiation, proliferation, and metabolic activity of primary human osteoblast-like cells (OBs) derived from the femoral heads of elderly patients. We found that all the proinflammatory cytokines, IL-1β, TNF-α, IL-6, and IL-8, enhanced the extracellular matrix mineralization of OBs under differentiation-induced cell culture conditions. In the cases of IL-1β and TNF-α, increased mineralization was correlated with increased osteoblast proliferation. Additionally, IL-1β- and TNF-α-increased osteogenesis was accompanied by a rise in energy metabolism due to improved glycolysis or mitochondrial respiration. In conclusion, we show here, for the first time, that, in contrast to findings obtained with cell lines, mesenchymal stem cells, or animal models, human OBs obtained from patients exhibited significantly enhanced osteogenesis upon exposure to proinflammatory cytokines, probably in part via a mechanism involving enhanced cellular energy metabolism. This study significantly contributes to the field of osteoimmunology by examining a clinically relevant cell model that can help to develop treatments for inflammation-related metabolic bone diseases.

Abstract A017: HER2 overexpression initiates breast tumorigenesis non-cell-autonomously by altering energy metabolism in the tissue microenvironment

Abstract Breast cancer is the most common cancer globally, with approximately 70% of pre-malignant breast tumors, known as ductal carcinoma in situ (DCIS), and 20% of invasive breast tumors overexpressing human epidermal growth factor receptor 2 (HER2). While the biological role of HER2 in invasive breast cancer has been extensively studied, its impact on breast cancer stem cells (BCSCs) and early-stage tumorigenesis, particularly within the tumor microenvironment, remains unclear. Here, we explore the role of HER2 overexpression in driving cellular events within the tumor microenvironment during the premalignant stage of breast tumorigenesis, using in vitro, in vivo, and ex vivo models. We conducted multi-omics analyses on mammary ducts from a HER2+ breast cancer mouse model at the pre-cancerous stage. Our results showed that HER2/Neu overexpression alters glucose and lipid metabolism and pentose phosphate pathway in mammary epithelial cells. Ex vivo organ culture of mammary ducts confirmed that these metabolic changes lead to increased reactive oxygen species (ROS) levels within the tumor microenvironment suggesting that oxidative stress and subsequent DNA damage are early events in HER2-driven tumorigenesis. Immunostaining of histological sections from mouse mammary glands further revealed that elevated oxidative stress and DNA damage not only in HER2+ cells but also in neighboring HER2- cells. Moreover, whole genome sequencing of tumor cells confirmed that both HER2+ and HER2- tumor cells have similar mutational burden. This suggests a non-cell-autonomous effect, where HER2 overexpression in one cell population affects the tumor microenvironment and adjacent cells, contributing to early-stage cancer development. To investigate the involvement of BCSCs during tumor initiation, we performed mammosphere assays on primary cells from HER2+ mouse models and clinical DCIS samples. Our findings showed that neither BCSCs nor their cells of origin express HER2 in both DCIS samples and murine mammary glands and tumors. This suggests that HER2 overexpression may not directly drive BCSC formation but rather creates a genotoxic microenvironment that facilitates the transformation of HER2- cell populations through a non-cell-autonomous mechanism. In summary, our findings indicate that HER2 overexpression contributes to the creation of a genotoxic tumor microenvironment by altering cellular energy metabolism and increasing ROS levels. This, in turn, may lead to the transformation of BCSCs in HER2- cell populations during early breast tumorigenesis. Understanding the role of HER2 overexpression in shaping the tumor microenvironment could provide new insights into therapeutic and preventive strategies against breast cancer. Citation Format: Sevim B. Gurler, Oliver Wagstaff, Lili Dimitrova, Fuhui Chen, Robert Pedley, William Weston, Ian J. Donaldson, Brian A. Telfer, David Novo, Kyriaki Pavlou, George Taylor, Yaqing Ou, Kaye Williams, Andrew Gilmore, Keith Brennan, Ahmet Ucar. HER2 overexpression initiates breast tumorigenesis non-cell-autonomously by altering energy metabolism in the tissue microenvironment [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr A017.

Ulinastatin attenuates renal fibrosis by regulating AMPK/HIF-1α signaling pathway-mediated glycolysis.

Renal fibrosis is a common outcome of chronic kidney diseases and glycolysis drives the development of renal fibrosis in damaged kidneys. Ulinastatin (UTI) is a broad-spectrum protease inhibitor with anti-inflammatory and antioxidant properties with anti-fibrosis effects. In this study, we aimed to verify whether UTI could exert anti-renal fibrosis effects by inhibiting glycolysis and explored the potential mechanisms. Renal fibrosis was induced in mice via unilateral ureteral obstruction (UUO). Transforming growth factor-β1 stimulates human kidney proximal tubular epithelial cells to undergo fibrotic changes. Histopathological staining was used to observe the pathological changes in the kidneys. The levels of fibrosis biomarkers, glycolytic enzymes, and key signaling molecules were determined using gene and protein assays. Cellular energy metabolism was measured using Seahorse XF24 analyzer. Modulated the activity of adenylate-activated protein kinase (AMPK) and hypoxia-inducible factor-1α (HIF-1α) to confirm that AMPK can regulate HIF-1α-mediated glycolysis. Furthermore, UTI and AMPK knockdown were combined to verify whether UTI could attenuate glycolysis via the AMPK pathway. UTI pretreatment improved UUO-induced renal injury and fibrosis. The expression of fibrosis biomarkers and glycolytic enzymes was reduced by UTI at both mRNA and protein levels. UTI treatment decreased the rate of glycolysis and the production of glycolytic intermediates in fibrotic cells and tissues. Furthermore, AMPK can regulate HIF-1α-mediated glycolysis in renal tubular epithelial cells. Finally, the attenuation of glycolysis by UTI was related to AMPK/HIF-1α pathway, and this effect was inhibited by knockdown AMPK. UTI can effectively alleviate renal fibrosis, which may be partly attributed to the reduction of glycolysis by regulating AMPK/HIF-1α pathway.

Three-Dimensional Semiconductor Network as Regulators of Energy Metabolism Drives Angiogenesis in Bone Regeneration.

Insufficient vascularization is a primary cause of bone implantation failure. The management of energy metabolism is crucial for the achievement of vascularized osseointegration. In light of the bone semiconductor property and the electric property of semiconductor heterojunctions, a three-dimensional semiconductor heterojunction network (3D-NTBH) implant has been devised with the objective of regulating cellular energy metabolism, thereby driving angiogenesis for bone regeneration. The three-dimensional heterojunction interfaces facilitate electron transfer and establish internal electric fields at the nanoscale interfaces. The 3D-NTBH was found to noticeably accelerate glycolysis in endothelial cells, thereby rapidly providing energy to support cellular metabolic activities and ultimately driving angiogenesis within the bone tissue. Molecular dynamic simulations have demonstrated that the 3D-NTBH facilitates the exposure of fibronectin's Arg-Gly-Asp peptide binding site, thereby regulating the glycolysis of endothelial cells. Further evidence suggests that 3D-NTBH promotes early vascular network reconstruction and bone regeneration in vivo. The findings of this research offer a promising research perspective for the design of vascularizing implants.

Novel biomarkers of mitochondrial dysfunction in Long COVID patients.

Coronavirus disease 2019 (COVID-19) can lead to severe acute respiratory syndrome, and while most individuals recover within weeks, approximately 30-40% experience persistent symptoms collectively known as Long COVID, post-COVID-19 syndrome, or post-acute sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (PASC). These enduring symptoms, including fatigue, respiratory difficulties, body pain, short-term memory loss, concentration issues, and sleep disturbances, can persist for months. According to recent studies, SARS-CoV-2 infection causes prolonged disruptions in mitochondrial function, significantly altering cellular energy metabolism. Our research employed transmission electron microscopy to reveal distinct mitochondrial structural abnormalities in Long COVID patients, notably including significant swelling, disrupted cristae, and an overall irregular morphology, which collectively indicates severe mitochondrial distress. We noted increased levels of superoxide dismutase 1 which signals oxidative stress and elevated autophagy-related 4B cysteine peptidase levels, indicating disruptions in mitophagy. Importantly, our analysis also identified reduced levels of circulating cell-free mitochondrial DNA (ccf-mtDNA) in these patients, serving as a novel biomarker for the condition. These findings underscore the crucial role of persistent mitochondrial dysfunction in the pathogenesis of Long COVID. Further exploration of the cellular and molecular mechanisms underlying post-viral mitochondrial dysfunction is critical, particularly to understand the roles of autoimmune reactions and the reactivation of latent viruses in perpetuating these conditions. This comprehensive understanding could pave the way for targeted therapeutic interventions designed to alleviate the chronic impacts of Long COVID. By utilizing circulating ccf-mtDNA and other novel mitochondrial biomarkers, we can enhance our diagnostic capabilities and improve the management of this complex syndrome.

Serum creatine kinase elevation following tyrosine kinase inhibitor treatment in cancer patients: Symptoms, mechanism, and clinical management.

Molecular targeted tyrosine kinase inhibitors (TKIs) have produced unprecedented treatment response in cancer therapy for patients harboring specific oncogenic mutations. While the TKIs are mostly well tolerated, they were reported to increase serum levels of creatine kinase (CK) and cause muscle metabolism-related toxicity. CK is an essential enzyme involved in cellular energy metabolism and muscle function. Elevated serum CK levels can arise from both physiological and pathological factors, as well as triggered by specific drug classes. The incidence of serum CK elevation induced by a few approved TKIs (brigatinib, binimetinib, cobimetinib-vemurafenib combination [Food and Drug Administration, United States]; aumolertinib, and sunvozertinib [only approved by National Medical Products Administration, China]) were over 35%. CK elevation-related symptoms include myopathy, myositis, inclusion body myositis (IBM), cardiotoxicity, rhabdomyolysis, rash, and acneiform dermatitis. High-level or severe symptomatic CK elevation may necessitate dose reduction and indirectly dampen TKI efficacy. This review presents an updated summary about the prevalence rate and recent research about mechanisms leading to TKI-induced serum CK elevation in cancer patients. The utility of monitoring serum CK levels for predicting TKI-induced adverse effects and their management will also be discussed.

Ginsenoside Rg1 Promotes Wound Healing in Mice with Superficial Second-Degree Burns Through Energy Metabolism, Cell Migration, and Cell Adhesion Pathways.

Natural products are known to have distinct roles in the treatment of various diseases. However, the potential role of ginsenoside Rg1 (GRg1) in the context of scald injuries remains unclear. This study aimed to elucidate the effects of GRg1 on scald wound healing by utilizing a mouse scald wound model and administering varying concentrations of GRg1 orally. RNA sequencing (RNA-seq) was employed to identify the signaling pathways and key genes influenced by GRg1 in the wound healing process. Our findings indicate that mice treated with a low concentration of GRg1 exhibited a significantly higher wound healing rate compared with the model group and other treatment groups. Through RNA-seq, we observed that the gene expression profile in the wound tissues of the low-concentration-treated group was consistent with that of the normal control group. Furthermore, a low concentration of GRg1 was found to maintain cellular energy metabolism homeostasis by enhancing mitochondrial aerobic respiration and the tricarboxylic acid cycle. In addition, GRg1 facilitated wound healing by restoring the expression of genes associated with cell migration and adhesion. Confirming the appropriate concentration of GRg1 that accelerates tissue healing at scald sites and enhances our understanding of the efficacy and molecular mechanisms underlying the therapeutic effects of natural products in disease treatment.

Exploring the Dynamic Changes of Brain Lipids, Lipid Rafts, and Lipid Droplets in Aging and Alzheimer’s Disease

Aging induces complex changes in the lipid profiles across different areas of the brain. These changes can affect the function of brain cells and may contribute to neurodegenerative diseases such as Alzheimer’s disease. Research shows that while the overall lipid profile in the human brain remains quite steady throughout adulthood, specific changes occur with age, especially after the age of 50. These changes include a slow decline in total lipid content and shifts in the composition of fatty acids, particularly in glycerophospholipids and cholesterol levels, which can vary depending on the brain region. Lipid rafts play a crucial role in maintaining membrane integrity and facilitating cellular signaling. In the context of Alzheimer’s disease, changes in the composition of lipid rafts have been associated with the development of the disease. For example, alterations in lipid raft composition can lead to increased accumulation of amyloid β (Aβ) peptides, contributing to neurotoxic effects. Lipid droplets store neutral lipids and are key for cellular energy metabolism. As organisms age, the dynamics of lipid droplets in the brain change, with evidence suggesting a decline in metabolic activity over time. This reduced activity may lead to an imbalance in lipid synthesis and mobilization, contributing to neurodegenerative processes. In model organisms like Drosophila, studies have shown that lipid metabolism in the brain can be influenced by diet and insulin signaling pathways, crucial for maintaining metabolic balance. The interplay between lipid metabolism, oxidative stress, and inflammation is critical in the context of aging and Alzheimer’s disease. Lipid peroxidation, a consequence of oxidative stress, can lead to the formation of reactive aldehydes that further damage neurons. Inflammatory processes can also disrupt lipid metabolism, contributing to the pathology of AD. Consequently, the accumulation of oxidized lipids can affect lipid raft integrity, influencing signaling pathways involved in neuronal survival and function.

A Spatiotemporally Controlled and Mitochondria-Targeted Prodrug of Hydrogen Sulfide Enables Mild Mitochondrial Uncoupling for the Prevention of Lipid Deposition.

Mild mitochondrial uncoupling offers therapeutic benefits for various diseases like obesity by regulating cellular energy metabolism. However, effective chemical intervention tools for inducing mild mitochondria-targeted uncoupling are limited. Herein, we have developed a mitochondria-targeted H2S prodrug M1 with a unique property of on-demand photoactivated generation of H2S accompanied by self-reporting fluorescence for real-time tracking. Upon photoirradiation, M1 decomposes in mitochondria to generate H2S and a turn-on fluorescent coumarin derivative for the visualization and quantification of H2S. M1 is confirmed to induce reactive oxygen species (ROS)-dependent mild mitochondrial uncoupling, activating mitochondria-associated adenosine monophosphate-activated protein kinase (AMPK) to suppress palmitic acid (PA)-induced lipid deposition in hepatocytes. The uncoupling functions induced by M1 are strictly controlled in mitochondria, representing a fresh strategy to prevent lipid deposition and improve metabolic syndrome by increasing cellular energy expenditure.

Advancing Anticancer Drug Discovery: Leveraging Metabolomics and Machine Learning for Mode of Action Prediction by Pattern Recognition.

A bottleneck in the development of new anti-cancer drugs is the recognition of their mode of action (MoA). Metabolomics combined with machine learning allowed to predict MoAs of novel anti-proliferative drug candidates, focusing on human prostate cancer cells (PC-3). As proof of concept, 38 drugs are studied with known effects on 16 key processes of cancer metabolism, profiling low molecular weight intermediates of the central carbon and cellular energy metabolism (CCEM) by LC-MS/MS. These metabolic patterns unveiled distinct MoAs, enabling accurate MoA predictions for novel agents by machine learning. The transferability of MoA predictions based on PC-3 cell treatments is validated with two other cancer cell models, i.e., breast cancer and Ewing's sarcoma, and show that correct MoA predictions for alternative cancer cells are possible, but still at some expense of prediction quality. Furthermore, metabolic profiles of treated cells yield insights into intracellular processes, exemplified for drugs inducing different types of mitochondrial dysfunction. Specifically, it is predicted that pentacyclic triterpenes inhibit oxidative phosphorylation and affect phospholipid biosynthesis, as confirmed by respiration parameters, lipidomics, and molecular docking. Using biochemical insights from individual drug treatments, this approach offers new opportunities, including the optimization of combinatorial drug applications.

Bioenergetic-active exosomes for cartilage regeneration and homeostasis maintenance.

Cartilage regeneration relies on adequate and continuous bioenergy supply to facilitate cellular differentiation and extracellular matrix synthesis. Chondrocytes frequently undergo energy stress under pathological conditions, characterized by disrupted cellular metabolism and reduced adenosine triphosphate (ATP) levels. However, there has limited progress in modulating energy metabolism for cartilage regeneration thus far. Here, we developed bioenergetic-active exosomes (Suc-EXO) to promote cartilage regeneration and homeostasis maintenance. Suc-EXO exhibited a 5.42-fold increase in ATP content, enabling the manipulation of cellular energy metabolism by fueling the TCA cycle. With continuous energy supply, Suc-EXO promoted BMSC chondrogenic differentiation via the P2X7-mediated PI3K-AKT pathway. Moreover, Suc-EXO improved chondrocyte anabolism and mitochondrial homeostasis via the P2X7-mediated SIRT3 pathway. In a rabbit cartilage defect model, the Suc-EXO-encapsulated hydrogel notably promoted cartilage regeneration and maintained neocartilage homeostasis, leading to 2.26 and 1.53 times increase in Col2 and ACAN abundance, respectively. These findings make a remarkable breakthrough in modulating energy metabolism for cartilage regeneration, offering immense potential for clinical translation.

Development of Malate Biosensor-Containing Hydrogels and Living Cell-Based Sensors.

Malate is a key intermediate in the citric acid cycle, an enzymatic cascade that is central to cellular energy metabolism and that has been applied to make biofuel cells. To enable real-time sensing of malate levels, we have engineered a genetically encoded, protein-based fluorescent biosensor called Malon specifically responsive to malate by performing structure-based mutagenesis of the Cache-binding domain of the Citron GFP-based biosensor. Malon demonstrates high specificity and fluorescence activation in response to malate, and has been applied to monitor enzymatic reactions in vitro. Furthermore, we successfully incorporated Malon into redox polymer hydrogels and bacterial cells, enabling analysis of malate levels in these materials and living systems. These results show the potential for fluorescent biosensors in enzymatic cascade monitoring within biomaterials and present Malon as a novel tool for bioelectronic devices.

SNP-Based and Kmer-Based eQTL Analysis Using Transcriptome Data.

Traditional expression quantitative trait locus (eQTL) mapping associates single nucleotide polymorphisms (SNPs) with gene expression, where the SNPs are derived from large-scale whole-genome sequencing (WGS) data or transcriptome data. While WGS provides a high SNP density, it also incurs substantial sequencing costs. In contrast, RNA-seq data, which are more accessible and less expensive, can simultaneously yield gene expressions and SNPs. Thus, eQTL analysis based on RNA-seq offers significant potential applications. Two primary strategies were employed for eQTL in this study. The first involved analyzing expression levels in relation to variant sites detected between populations from RNA-seq data. The second approach utilized kmers, which are sequences of length k derived from RNA-seq reads, to represent variant sites and associated these kmer genotypes with gene expression. We discovered 87 significant association signals involving eGene on the basis of the SNP-based eQTL analysis. These genes include DYNLT1, NMNAT1, and MRLC2, which are closely related to neurological functions such as motor coordination and homeostasis, play a role in cellular energy metabolism, and function in regulating calcium-dependent signaling in muscle contraction, respectively. This study compared the results obtained from eQTL mapping using RNA-seq identified SNPs and gene expression with those derived from kmers. We found that the vast majority (23/30) of the association signals overlapping the two methods could be verified by haplotype block analysis. This comparison elucidates the strengths and limitations of each method, providing insights into their relative efficacy for eQTL identification.

The effects of sodium-glucose cotransporter 2 inhibitors on the 'forgotten' right ventricle.

With the progress in diagnosis, treatment and imaging techniques, there is a growing recognition that impaired right ventricular (RV) function profoundly affects the prognosis of patients with heart failure (HF), irrespective of their left ventricular ejection fraction (LVEF). In addition, right HF (RHF) is a common complication associated with various diseases, including congenital heart disease, myocardial infarction (MI), pulmonary arterial hypertension (PAH) and dilated cardiomyopathy (DCM), and it can manifest at any time after left ventricular assist devices (LVADs). The sodium-glucose cotransporter 2 (SGLT2) inhibition by gliflozins has emerged as a cornerstone medicine for managing type 2 diabetes mellitus (T2DM) and HF, with an increasing focus on its potential to enhance RV function. In this review, we aim to present an updated perspective on the pleiotropic effects of gliflozins on the right ventricle and offer insights into the underlying mechanisms. We can ascertain their advantageous impact on the right ventricle by discussing the evidence obtained in animal models and monumental clinical trials. In light of the pathophysiological changes in RHF, we attempt to elucidate crucial mechanisms regarding their beneficial effects, including alleviation of RV overload, reduction of hyperinsulinaemia and inflammatory responses, regulation of nutrient signalling pathways and cellular energy metabolism, inhibition of oxidative stress and myocardial fibrosis, and maintenance of ion balance. Finally, this drug class's potential application and benefits in various clinical settings are described, along with a prospective outlook on future clinical practice and research directions.

7086 Disrupted Mitochondrial Function in Alström Syndrome- A Monogenic Model of Insulin Resistance and Obesity

Abstract Disclosure: S. Ali: None. S. Heising: None. V. Veeranna: None. A. Vincent: None. G.S. Xavier: None. T. Geberhiwot: None. Alström syndrome (ALMS) is a rare monogenic disease typified by severe insulin resistance (IR) and obesity. IR and obesity are cardinal features of metabolic syndrome. The metabolic effects of insulin at key target tissues leads to metabolic haemostasis by promoting glucose and lipid uptake and metabolism to generate energy in cells. Although insulin is a major regulator of fuel metabolism, its effects on mitochondrial ATP production in severe insulin resistance are unclear. RNASeq data from adipose tissue (AT) from patients with ALMS show downregulation of the expression of genes associated with mitochondrial respiratory chain function, pointing towards possible altered mitochondrial function in ALMS. We therefore undertook a detailed assessment of mitochondrial oxidative phosphorylation capacity (OXPHOS) in skeletal muscle (SM) in ALMS. We performed SM biopsy in 10 ALMS and 10 healthy control volunteers that were age, gender and Body Mass Index matched. The SM was subjected to high resolution respirometry, the gold standard method to quantify mitochondrial function ex vivo, using OROBOROS Oxygraph -2k (O2k) system. Overall OXPHOS was higher in control SM compared to ALMS, with maximal respiration of 62.96±19.2 and 44.24 ± 12.53 pmol/(s*mg), respectively (p<0.05).Reduced oxygen influx was observed in ALMS SM in comparison to controls for fatty acid ß oxidation (6.7±5.96 vs 7.87±2.7 pmol/(s*mg);p<0.05, at complex I (19.4 ± 8.98 vs 29.7 ±5.3 pmol/(s*mg);p<0.05, and at complex II (34.98 ±11.75 vs 53.52± 13.2 pmol/(s*mg) ;p<0.05. Mitochondrial membrane integrity was unaffected during these experiments. Therefore, our analysis unveils a consistent reduction in mitochondrial respiration across all the electron transport pathway. This noteworthy finding suggests impairment in respiratory function and the electron transport chain in mitochondria, a crucial aspect of cellular energy metabolism. Several studies have previously linked IR with mitochondrial dysfunction, where insulin-resistant rodents and humans have shown blunted mitochondrial response to ATP generation. Our results align with this body of evidence emphasizing the significance of investigating the underlying mechanism contributing to this phenomenon. These findings could pave the way to exploring potential mitochondrial-targeted therapies to restore mitochondrial function and therefore, improve insulin sensitivity to tackle IR in ALMS. Presentation: 6/2/2024

CHAC1 blockade suppresses progression of lung adenocarcinoma by interfering with glucose metabolism via hijacking PKM2 nuclear translocation.

Patients with lung adenocarcinoma (LUAD) generally have poor prognosis. Abnormal cellular energy metabolism is a hallmark of LUAD. Glutathione-specific gamma-glutamylcyclotransferase 1 (CHAC1) is a member of the γ-glutamylcyclotransferase family and an unfolded protein response pathway regulatory gene. Its biological function and molecular regulatory mechanism, especially regarding energy metabolism underlying LUAD, remain unclear. By utilizing tissue microarray and data from The Cancer Genome Atlas and Gene Expression Omnibus, we found that CHAC1 expression was markedly higher in LUAD tissues than in non-tumor tissues, and was positively correlated with poor prognosis. Phenotypically, CHAC1 overexpression enhanced the proliferation, migration, invasion, tumor sphere formation, and glycolysis ability of LUAD cells, resulting in tumor growth both in vitro and in vivo. Mechanistically, through a shotgun mass spectrometry-based proteomic approach and high-throughput RNA sequencing, we found that CHAC1 acted as a bridge connecting UBA2 and PKM2, enhancing the SUMOylation of PKM2. The SUMOylated PKM2 then transferred from the cytoplasm to the nucleus, activating the expression of glycolysis-related genes and enhancing the Warburg effect. Lastly, E2F Transcription Factor 1 potently activated CHAC1 transcription by directly binding to the CHAC1 promoter in LUAD cells. The results of this study implied that CHAC1 regulates energy metabolism and promotes glycolysis in LUAD progression.

The effects of metformin on inflammation and apoptosis in rats with preeclampsia.

Defined clinically by elevated blood pressure along with either proteinuria and/or maternal organ dysfunction, representing a major cause of morbidity and mortality pregnant women and newborns. Metformin (MET), an oral antidiabetic medication, has been shown to prevent preeclampsia (PE) through various mechanisms, including reducing inflammation, improving endothelial dysfunction, improving mitochondrial function, and altering cellular homeostasis and energy metabolism. Herein, we explored the role of MET in PE and its underlying molecular mechanisms using in in vivo experiments. RT-qPCR, Western blot (WB), and immunohistochemistry (IHC) were conducted to assess the mRNA or protein expression of genes related to mitochondrial apoptosis. Additionally, ELISA was conducted to quantify the expression of mitochondrial apoptosis and inflammation-related genes, as well as PE biomarkers. Treatment with MET in PE rats ameliorated hypertension and proteinuria, altered the expression of PE biomarkers, and significantly inhibited L-NAME-induced inflammation and cell apoptosis. MET modulated the levels of inflammatory cytokines tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, and IL-10, mitigating inflammation in PE rats. Furthermore, MET regulated mitochondrial outer membrane permeability (MOMP), thereby reducing cell apoptosis occurring in the mitochondrial pathway of PE rats. This study demonstrates that MET alleviates inflammation and cell apoptosis in PE rats by modulating the expression of inflammatory factors and MOMP. Our results indicate that MET has huge therapeutic potential against PE.

NMR-Based Analysis of Cellular Central Energy Metabolism and Exchange Rates.

Cell cultures are widely used in studies to gain mechanistic insights of metabolic processes. The foundation of these studies lies on the quantification of intracellular and extracellular metabolites, and nuclear magnetic resonance (NMR) is one of the key analytical platforms used to this aim. Among the factors influencing the quality of the produced data are the sampling procedures as well as the acquisition and processing of spectroscopic data. Here we provide our workflow for obtaining quantitative metabolic data from adherent mammalian cells using NMR spectroscopy. The described protocol is compatible with other analytical methods like LC- or GC-MS-based lipidomics and untargeted metabolomics from the same sample. We also show how the collected extracellular data can be used to extract exchange flux rates, particularly useful for flux analysis studies and metabolic engineering of human-induced pluripotent stem cells.

Differences in body condition and hepatic cellular metabolism among distinct populations of cestode-infected pumpkinseed sunfish (Lepomis gibbosus)

Host populations can vary in the prevalence and intensity of their parasites, which may influence the impacts of infection on host physiology and health. Parasite-induced effects on hosts may be due to underlying changes in cellular energy metabolism, predominantly driven by the mitochondria. However, limited research has been conducted on understanding variation in host–parasite interactions across populations. We sampled three wild populations of pumpkinseed sunfish ( Lepomis gibbosus (Linnaeus, 1758)), two of which are infected by cestodes, to study correlations among infection intensity, host body condition, and key metabolic enzyme activities in liver tissue. In both infected populations, cestode infection was associated with reduced hepatic lipid metabolism and increased hepatic lactic fermentation. Interestingly, Lake Cromwell fish showed a decrease in body condition, electron transport system activity, and antioxidant activity with cestode intensity, whereas the contrary was observed for Lake Long fish. This suggests that Lake Long fish could be boosting their immune system and food intake to better tolerate infection, unlike Cromwell fish. This study not only highlights how different populations can vary in their response to parasite infections but also the importance of accounting for infection when studying animal physiology.