bims-medica Biomed News
on Metabolism and diet in cancer
Issue of 2023‒12‒24
thirty-six papers selected by
Brett Chrest, East Carolina University



  1. Cureus. 2023 Nov;15(11): e48821
      India experiences a significant amount of morbidity and mortality due to gliomas particularly glioblastoma multiforme (GBM), which ranks among the worst cancers. Oxaloacetate (OAA) is a human keto acid that is central to cellular metabolism; it has been recognized by the US FDA for use in GBM patients, triggering a review to revisit the cellular mechanism of its therapeutic action. Various cellular and molecular studies have proposed that instead of fueling the tricarboxylic acid (TCA) cycle and oxidative phosphorylation (OXPHOS), gliomas prefer to use glycolysis (the Warburg effect) to fuel macromolecules for the synthesis of nucleotides, fatty acids, and amino acids for the accelerated mitosis. A study found that oxaloacetate (OAA) inhibits human lactate dehydrogenase A (LDHA) in cancer cells, reversing the Warburg effect. Studies revealed that OAA supplementation reduced Warburg glycolysis, improved neuronal cell bioenergetics, and triggered brain mitochondrial biogenesis, thereby enhancing the efficacy of standard treatment. Similarly, OAA has been found in preclinical investigations to be able to decrease tumor development and survival rates by blocking the conversion of glutamine to alpha-ketoglutarate (alpha-KG) in the TCA cycle and lowering nicotinamide adenine dinucleotide phosphate (NADPH) levels. OAA is a safe adjuvant that has the potential to be an effective therapy in gliomas when combined with temozolomide (TMZ) chemotherapy and routine surgery.
    Keywords:  adjunctive therapy; alter warburg effect; glutamate excitotoxicity; oxaloacetate;  glioma
    DOI:  https://doi.org/10.7759/cureus.48821
  2. Cancers (Basel). 2023 Dec 06. pii: 5724. [Epub ahead of print]15(24):
      Deregulation of cellular metabolism has recently emerged as a notable cancer characteristic. This reprogramming of key metabolic pathways supports tumor growth. Targeting cancer metabolism demonstrates the potential for managing colorectal cancer. Beta-hydroxybutyrate (BOHB) acts as an acetyl-CoA source for the tricarboxylic acid (TCA) cycle, possibly redirecting energy metabolic pathways towards the TCA cycle that could enhance sensitivity to oxaliplatin, through the generation of reactive oxygen species (ROS). This study explores the potential of BOHB to enhance oxaliplatin's cytotoxic effect by altering the energy metabolism in colorectal cancer. The study employed advanced in vitro organoid technology, which successfully emulates in vivo physiology. The combination treatment efficacy of BOHB and oxaliplatin was evaluated via cell viability assay. The levels of key proteins involved in energy metabolism, apoptotic pathways, DNA damage markers, and histone acetylation were analyzed via Western Blot. ROS levels were evaluated via flow cytometer. Non-toxic doses of BOHB with oxaliplatin significantly amplified cytotoxicity in colorectal cancer organoids. Treatment with BOHB and/or melatonin resulted in significantly decreased lactate dehydrogenase A and increased mitochondrial carrier protein 2 levels, indicating inhibited aerobic glycolysis and an increased oxidative phosphorylation rate. This metabolic shift induced apoptotic cell death mediated by oxaliplatin, owing to high levels of ROS. Melatonin counteracted this effect by protecting cancer cells from high oxidative stress conditions. BOHB may enhance the efficacy of chemotherapeutics with a similar mechanism of action to oxaliplatin in colorectal cancer treatment. These innovative combinations could improve treatment outcomes for colorectal cancer patients.
    Keywords:  beta-hydroxybutyrate; colorectal cancer; metabolic targeted therapy; organoid; oxaliplatin; reactive oxygen species
    DOI:  https://doi.org/10.3390/cancers15245724
  3. Int J Mol Sci. 2023 Dec 15. pii: 17533. [Epub ahead of print]24(24):
      The disruption of mitochondrial dynamics has been identified in cardiovascular diseases, including pulmonary hypertension (PH), ischemia-reperfusion injury, heart failure, and cardiomyopathy. Mitofusin 2 (Mfn2) is abundantly expressed in heart and pulmonary vasculature cells at the outer mitochondrial membrane to modulate fusion. Previously, we have reported reduced levels of Mfn2 and fragmented mitochondria in pulmonary arterial endothelial cells (PAECs) isolated from a sheep model of PH induced by pulmonary over-circulation and restoring Mfn2 normalized mitochondrial function. In this study, we assessed the effect of increased expression of Mfn2 on mitochondrial metabolism, bioenergetics, reactive oxygen species production, and mitochondrial membrane potential in control PAECs. Using an adenoviral expression system to overexpress Mfn2 in PAECs and utilizing 13C labeled substrates, we assessed the levels of TCA cycle metabolites. We identified increased pyruvate and lactate production in cells, revealing a glycolytic phenotype (Warburg phenotype). Mfn2 overexpression decreased the mitochondrial ATP production rate, increased the rate of glycolytic ATP production, and disrupted mitochondrial bioenergetics. The increase in glycolysis was linked to increased hypoxia-inducible factor 1α (HIF-1α) protein levels, elevated mitochondrial reactive oxygen species (mt-ROS), and decreased mitochondrial membrane potential. Our data suggest that disrupting the mitochondrial fusion/fission balance to favor hyperfusion leads to a metabolic shift that promotes aerobic glycolysis. Thus, therapies designed to increase mitochondrial fusion should be approached with caution.
    Keywords:  glycolysis; metabolomics; mitochondrial function; mitofusin; pulmonary hypertension
    DOI:  https://doi.org/10.3390/ijms242417533
  4. Rapid Commun Mass Spectrom. 2024 Jan 30. 38(2): e9670
      RATIONALE: Multicellular tumor spheroids (MCTSs) that reconstitute the metabolic characteristics of in vivo tumor tissue may facilitate the discovery of molecular biomarkers and effective anticancer therapies. However, little is known about how cancer cells adapt their metabolic changes in complex three-dimensional (3D) microenvironments. Here, using the two-dimensional (2D) cell model as control, the metabolic phenotypes of glioma U87MG multicellular tumor spheroids were systematically investigated based on static metabolomics and dynamic fluxomics analysis.METHODS: A liquid chromatography-mass spectrometry-based global metabolomics and lipidomics approach was adopted to survey the cellular samples from 2D and 3D culture systems, revealing marked molecular differences between them. Then, by means of metabolomic pathway analysis, the metabolic pathways altered in glioma MCTSs were found using 13 C6 -glucose as a tracer to map the metabolic flux of glycolysis, the tricarboxylic acid (TCA) cycle, de novo nucleotide synthesis, and de novo lipid biosynthesis in the MCTS model.
    RESULTS: We found nine metabolic pathways as well as glycerolipid, glycerophospholipid and sphingolipid metabolism to be predominantly altered in glioma MCTSs. The reduced nucleotide metabolism, amino acid metabolism and glutathione metabolism indicated an overall lower cellular activity in MCTSs. Through dynamic fluxomics analysis in the MCTS model, we found that cells cultured in MCTSs exhibited increased glycolysis activity and de novo lipid biosynthesis activity, and decreased the TCA cycle and de novo purine nucleotide biosynthesis activity.
    CONCLUSIONS: Our study highlights specific, altered biochemical pathways in MCTSs, emphasizing dysregulation of energy metabolism and lipid metabolism, and offering novel insight into metabolic events in glioma MCTSs.
    DOI:  https://doi.org/10.1002/rcm.9670
  5. Cancer Res. 2023 Dec 20.
      A promising approach to treat solid tumors involves disrupting their reliance on glutamine, a key component for various metabolic processes. Traditional attempts using glutamine inhibitors like 6-diazo-5-oxo-L-norleucine (DON) and CB-839 were unsuccessful, but new hope arises with DRP-104, a pro-drug of DON. This compound effectively targets tumor metabolism while minimizing side effects. In a recent study published in Nature Cancer, Encarnación-Rosado and colleagues demonstrated in pre-clinical models that pancreatic ductal adenocarcinoma (PDAC) responds well to DRP-104, though tumors adapt through the MEK/ERK signaling pathway, which can be countered by the MEK inhibitor trametinib. In a related study, Recouvreux and colleagues found that DON is effective against pancreatic tumors, revealing that PDAC tumors upregulate asparagine synthesis in response to DON, making them susceptible to asparaginase treatment. Both studies underscore the potential of inhibiting glutamine metabolism and adaptive pathways as a promising strategy against PDAC. These findings pave the way for upcoming clinical trials utilizing DRP-104 and similar glutamine antagonists in the battle against solid tumors.
    DOI:  https://doi.org/10.1158/0008-5472.CAN-23-3954
  6. Int J Mol Sci. 2023 Dec 07. pii: 17238. [Epub ahead of print]24(24):
      Metabolic reprogramming, especially reprogrammed glucose metabolism, is a well-known cancer hallmark related to various characteristics of tumor cells, including proliferation, survival, metastasis, and drug resistance. Glucose-6-phosphate dehydrogenase (G6PD) is the first and rate-limiting enzyme of the pentose phosphate pathway (PPP), a branch of glycolysis, that converts glucose-6-phosphate (G6P) into 6-phosphogluconolactone (6PGL). Furthermore, PPP produces ribose-5-phosphate (R5P), which provides sugar-phosphate backbones for nucleotide synthesis as well as nicotinamide adenine dinucleotide phosphate (NADPH), an important cellular reductant. Several studies have shown enhanced G6PD expression and PPP flux in various tumor cells, as well as their correlation with tumor progression through cancer hallmark regulation, especially reprogramming cellular metabolism, sustaining proliferative signaling, resisting cell death, and activating invasion and metastasis. Inhibiting G6PD could suppress tumor cell proliferation, promote cell death, reverse chemoresistance, and inhibit metastasis, suggesting the potential of G6PD as a target for anti-tumor therapeutic strategies. Indeed, while challenges-including side effects-still remain, small-molecule G6PD inhibitors showing potential anti-tumor effect either when used alone or in combination with other anti-tumor drugs have been developed. This review provides an overview of the structural significance of G6PD, its role in and regulation of tumor development and progression, and the strategies explored in relation to G6PD-targeted therapy.
    Keywords:  anti-tumor therapy; drug resistance; glucose-6-phosphate dehydrogenase (G6PD); pentose phosphate pathway (PPP); tumor cell proliferation; tumor metabolism
    DOI:  https://doi.org/10.3390/ijms242417238
  7. Mol Oncol. 2023 Dec 19.
      Glucose catabolism, one of the essential pathways sustaining cellular bioenergetics, has been widely studied in the context of tumors. Nevertheless, the function of various branches of glucose metabolism that stem from 'classical' glycolysis have only been partially explored. This review focuses on discussing general mechanisms and pathological implications of glycolysis and its branching pathways in the biology of B cell malignancies. We summarize here what is known regarding pentose phosphate, hexosamine, serine biosynthesis and glycogen synthesis pathways in this group of tumors. Despite most findings have been based on malignant B cells themselves, we also discuss the role of glucose metabolism in the tumor microenvironment, with a focus on T cells. Understanding the contribution of glycolysis branching pathways and how they are hijacked in B cell malignancies will help to dissect the role they have in sustaining the dissemination and proliferation of tumor B cells and regulating immune responses within these tumors. Ultimately, this should lead to deciphering associated vulnerabilities and improve current therapeutic schedules.
    Keywords:  B cells; T cells; glucose metabolism; tumor microenvironment
    DOI:  https://doi.org/10.1002/1878-0261.13570
  8. Biomedicines. 2023 Nov 30. pii: 3186. [Epub ahead of print]11(12):
      Metabolic reprogramming is a key alteration in tumorigenesis. In cancer cells, changes in metabolic fluxes are required to cope with large demands on ATP, NADPH, and NADH, as well as carbon skeletons. In particular, dysregulation in lipid metabolism ensures a great energy source for the cells and sustains cell membrane biogenesis and signaling molecules, which are necessary for tumor progression. Increased lipid uptake and synthesis results in intracellular lipid accumulation as lipid droplets (LDs), which in recent years have been considered hallmarks of malignancies. Here, we review current evidence implicating the biogenesis, composition, and functions of lipid droplets in acute myeloid leukemia (AML). This is an aggressive hematological neoplasm originating from the abnormal expansion of myeloid progenitor cells in bone marrow and blood and can be fatal within a few months without treatment. LD accumulation positively correlates with a poor prognosis in AML since it involves the activation of oncogenic signaling pathways and cross-talk between the tumor microenvironment and leukemic cells. Targeting altered LD production could represent a potential therapeutic strategy in AML. From this perspective, we discuss the main inhibitors tested in in vitro AML cell models to block LD formation, which is often associated with leukemia aggressiveness and which may find clinical application in the future.
    Keywords:  PPARγ; acute myeloid leukemia (AML); chemotherapy resistance; lipid droplets (LDs); lipid metabolism
    DOI:  https://doi.org/10.3390/biomedicines11123186
  9. Biomed Pharmacother. 2023 Dec 20. pii: S0753-3322(23)01808-5. [Epub ahead of print]170 116010
      Triple-negative breast cancer (TNBC) is associated with metabolic heterogeneity and poor prognosis with limited treatment options. New treatment paradigms for TNBC remains an unmet need. Thus, therapeutics that target metabolism are particularly attractive approaches. We previously designed organometallic Au(III) compounds capable of modulating mitochondrial respiration by ligand tuning with high anticancer potency in vitro and in vivo. Here, we show that an efficacious Au(III) dithiocarbamate (AuDTC) compound induce mitochondrial dysfunction and oxidative damage in cancer cells. Efficacy of AuDTC in TNBC mouse models harboring mitochondrial oxidative phosphorylation (OXPHOS) dependence and metabolic heterogeneity establishes its therapeutic potential following systemic delivery. This provides evidence that AuDTC is an effective modulator of mitochondrial respiration worthy of clinical development in the context of TNBC. ONE SENTENCE SUMMARY: Metabolic-targeting of triple-negative breast cancer by gold anticancer agent may provide efficacious therapy.
    Keywords:  Gold; Mitochondria; OXPHOS; Triple negative breast cancer
    DOI:  https://doi.org/10.1016/j.biopha.2023.116010
  10. Cell Metab. 2023 Dec 14. pii: S1550-4131(23)00449-7. [Epub ahead of print]
      Contrary to their well-known functions in nutrient breakdown, mitochondria are also important biosynthetic hubs and express an evolutionarily conserved mitochondrial fatty acid synthesis (mtFAS) pathway. mtFAS builds lipoic acid and longer saturated fatty acids, but its exact products, their ultimate destination in cells, and the cellular significance of the pathway are all active research questions. Moreover, why mitochondria need mtFAS despite their well-defined ability to import fatty acids is still unclear. The identification of patients with inborn errors of metabolism in mtFAS genes has sparked fresh research interest in the pathway. New mammalian models have provided insights into how mtFAS coordinates many aspects of oxidative mitochondrial metabolism and raise questions about its role in diseases such as obesity, diabetes, and heart failure. In this review, we discuss the products of mtFAS, their function, and the consequences of mtFAS impairment across models and in metabolic disease.
    Keywords:  fatty acids; inborn errors of metabolism; lipid metabolism; lipids; mitochondria; mitochondrial fatty acid synthesis; mouse models; mtFAS
    DOI:  https://doi.org/10.1016/j.cmet.2023.11.017
  11. FEBS Open Bio. 2023 Dec 17.
      Inorganic polyphosphate (polyP) plays a vital role in cellular energy metabolism and signaling, owing to its structure and high-energy phosphate bonds. Intracellular ATP functions both as a cellular energy source and a key factor in cell death, and ATP dynamics in tumor cells are crucial for advancing cancer therapy. In this study, we explored the interplay between polyP and ATP in cellular energy metabolism. Treatment with polyP did not affect cell proliferation of human non-small cell lung cancer H1299 and human glioblastoma T98G cell lines as compared to their respective control cells until 72 h post-treatment. The mitochondrial membrane potential (MMP) in polyP-treated cells was low, contrasting with the time-dependent increase observed in control cells. While the ATP content increased over time in untreated and Na-phosphate-treated control cells, it remained unchanged in polyP-treated cells. Furthermore, the addition of cyclosporine A, a mitochondrial permeability transition pore (mPTP) inhibitor, failed to restore ATP levels in polyP-treated cells. We performed lactate assays and western blot analysis to evaluate the effect of polyP on glucose metabolism and found no significant differences in lactate secretion or glucose-6-phosphate dehydrogenase (G6PD) activity between polyP-treated and control cells. Additional pyruvate restored MMP but had no effect on the cellular ATP content in polyP-treated cells. Moreover, we observed no correlation between the Warburg effect and glucose metabolism during ATP depletion in polyP-treated cells. Further investigation is warranted to explore the roles of polyP and ATP in cancer cell energy metabolism, which might offer potential avenues for therapeutic interventions.
    Keywords:  adenosine triphosphate (ATP); human non-small cell lung cancer cells; inorganic polyphosphate; mitochondria; mitochondrial membrane potential
    DOI:  https://doi.org/10.1002/2211-5463.13753
  12. SLAS Discov. 2023 Dec 13. pii: S2472-5552(23)00084-9. [Epub ahead of print]
      Combination therapies have improved outcomes for patients with acute myeloid leukemia (AML). However, these patients still have poor overall survival. Although many combination therapies are identified with high-throughput screening (HTS), these approaches are constrained to disease models that can be grown in large volumes (e.g., immortalized cell lines), which have limited translational utility. To identify more effective and personalized treatments, we need better strategies for screening and exploring potential combination therapies. Our objective was to develop an HTS platform for identifying effective combination therapies with highly translatable ex vivo disease models that use size-limited, primary samples from patients with leukemia (AML and myelodysplastic syndrome). We developed a system, ComboFlow, that comprises three main components: MiniFlow, ComboPooler, and AutoGater. MiniFlow conducts ex vivo drug screening with a miniaturized flow-cytometry assay that uses minimal amounts of patient sample to maximize throughput. ComboPooler incorporates computational methods to design efficient screens of pooled drug combinations. AutoGater is an automated gating classifier for flow cytometry that uses machine learning to rapidly analyze the large datasets generated by the assay. We used ComboFlow to efficiently screen more than 3000 drug combinations across 20 patient samples using only 6 million cells per patient sample. In this screen, ComboFlow identified the known synergistic combination of bortezomib and panobinostat. ComboFlow also identified a novel drug combination, dactinomycin and fludarabine, that synergistically killed leukemic cells in 35 % of AML samples. This combination also had limited effects in normal, hematopoietic progenitors. In conclusion, ComboFlow enables exploration of massive landscapes of drug combinations that were previously inaccessible in ex vivo models. We envision that ComboFlow can be used to discover more effective and personalized combination therapies for cancers amenable to ex vivo models.
    Keywords:  Acute myeloid leukemia; Cancer; Drug discovery; High-throughput screening; Precision medicine; flow cytometry
    DOI:  https://doi.org/10.1016/j.slasd.2023.12.001
  13. Int J Mol Sci. 2023 Dec 18. pii: 17633. [Epub ahead of print]24(24):
      Glioma cells exhibit genetic and metabolic alterations that affect the deregulation of several cellular signal transduction pathways, including those related to glucose metabolism. Moreover, oncogenic signaling pathways induce the expression of metabolic genes, increasing the metabolic enzyme activities and thus the critical biosynthetic pathways to generate nucleotides, amino acids, and fatty acids, which provide energy and metabolic intermediates that are essential to accomplish the biosynthetic needs of glioma cells. In this review, we aim to explore how dysregulated metabolic enzymes and their metabolites from primary metabolism pathways in glioblastoma (GBM) such as glycolysis and glutaminolysis modulate anabolic and catabolic metabolic pathways as well as pro-oncogenic signaling and contribute to the formation, survival, growth, and malignancy of glioma cells. Also, we discuss promising therapeutic strategies by targeting the key players in metabolic regulation. Therefore, the knowledge of metabolic reprogramming is necessary to fully understand the biology of malignant gliomas to improve patient survival significantly.
    Keywords:  glioma; glucose; glutamine; metabolism; oncogenic pathways
    DOI:  https://doi.org/10.3390/ijms242417633
  14. Cancer Metab. 2023 Dec 18. 11(1): 27
      BACKGROUND: Hepatocellular carcinoma (HCC) is a principal type of liver cancer with high incidence and mortality rates. Regorafenib is a novel oral multikinase inhibitor for second-line therapy for advanced HCC. However, resistance to regorafenib is gradually becoming a dilemma for HCC and the mechanism remains unclear. In this study, we aimed to reveal the metabolic profiles of regorafenib-resistant cells and the key role and mechanism of the most relevant metabolic pathway in regorafenib resistance.METHODS: Metabolomics was performed to detect the metabolic alteration between drug-sensitive and regorafenib-resistant cells. Colony formation assay, CCK-8 assay and flow cytometry were applied to observe cell colony formation, cell proliferation and apoptosis, respectively. The protein and mRNA levels were detected by western blot and RT-qPCR. Cell lines of Glucose-6-phosphate dehydrogenase(G6PD) knockdown in regorafenib-resistant cells or G6PD overexpression in HCC cell lines were stably established by lentivirus infection technique. G6PD activity, NADPH level, NADPH/NADP+ ratio, the ratio of ROS positive cells, GSH level, and GSH/GSSG ratio were detected to evaluate the anti-oxidative stress ability of cells. Phosphorylation levels of NADK were evaluated by immunoprecipitation.
    RESULTS: Metabonomics analysis revealed that pentose phosphate pathway (PPP) was the most relevant metabolic pathway in regorafenib resistance in HCC. Compared with drug-sensitive cells, G6PD enzyme activity, NADPH level and NADPH/NADP+ ratio were increased in regorafenib-resistant cells, but the ratio of ROS positive cells and the apoptosis rate under the conditions of oxidative stress were decreased. Furthermore, G6PD suppression using shRNA or an inhibitor, sensitized regorafenib-resistant cells to regorafenib. In contrast, G6PD overexpression blunted the effects of regorafenib to drug-sensitive cells. Mechanistically, G6PD, the rate-limiting enzyme of PPP, regulated the PI3K/AKT activation. Furthermore, PI3K/AKT inhibition decreased G6PD protein expression, G6PD enzymatic activity and the capacity of PPP to anti-oxidative stress possibly by inhibited the expression and phosphorylation of NADK.
    CONCLUSION: Taken together, a feedback loop of PPP and PI3K/AKT signal pathway drives regorafenib-resistance in HCC and targeting the feedback loop could be a promising approach to overcome drug resistance.
    Keywords:  Glucose-6-phosphate dehydrogenase; Hepatocellular carcinoma; Metabonomics; NAD kinase; PI3K/AKT signaling pathway; Pentose phosphate pathway; Regorafenib
    DOI:  https://doi.org/10.1186/s40170-023-00311-5
  15. Cold Spring Harb Perspect Med. 2023 Dec 18. pii: a041661. [Epub ahead of print]
      During the last decade, biomedical research has experienced a resurgence in the use of three-dimensional culture models for studies of normal and cancer biology. This resurgence has been driven by the development of models in which primary cells are grown in tissue-mimicking media and extracellular matrices to create organoid or organotypic cultures that more faithfully replicate the complex architecture and physiology of normal tissues and tumors. In addition, patient-derived tumor organoids preserve the three-dimensional organization and characteristics of the patient tumors ex vivo, becoming excellent preclinical models to supplement studies of tumor xenografts transplanted into immunocompromised mice. In this perspective, we provide an overview of how organoids are being used to investigate normal mammary biology and as preclinical models of breast cancer and discuss improvements that would enhance their utility and relevance to the field.
    DOI:  https://doi.org/10.1101/cshperspect.a041661
  16. Biomedicines. 2023 Dec 07. pii: 3248. [Epub ahead of print]11(12):
      Acute myeloid leukemia (AML) is a rare subtype of acute leukemia in the pediatric and adolescent population but causes disproportionate morbidity and mortality in this age group. Standard chemotherapeutic regimens for AML have changed very little in the past 3-4 decades, but the addition of targeted agents in recent years has led to improved survival in select subsets of patients as well as a better biological understanding of the disease. Currently, one key paradigm of bench-to-bedside practice in the context of adult AML is the focus on leukemia stem cell (LSC)-targeted therapies. Here, we review current and emerging immunotherapies and other targeted agents that are in clinical use for pediatric AML through the lens of what is known (and not known) about their LSC-targeting capability. Based on a growing understanding of pediatric LSC biology, we also briefly discuss potential future agents on the horizon.
    Keywords:  immunotherapy; leukemia stem cell (LSC); pediatric AML; targeted therapy
    DOI:  https://doi.org/10.3390/biomedicines11123248
  17. Nat Commun. 2023 Dec 20. 14(1): 8474
      Hepatic steatosis is the result of imbalanced nutrient delivery and metabolism in the liver and is the first hallmark of Metabolic dysfunction-associated steatotic liver disease (MASLD). MASLD is the most common chronic liver disease and involves the accumulation of excess lipids in hepatocytes, inflammation, and cancer. Mitochondria play central roles in liver metabolism yet the specific mitochondrial functions causally linked to MASLD remain unclear. Here, we identify Mitochondrial Fission Process 1 protein (MTFP1) as a key regulator of mitochondrial and metabolic activity in the liver. Deletion of Mtfp1 in hepatocytes is physiologically benign in mice yet leads to the upregulation of oxidative phosphorylation (OXPHOS) activity and mitochondrial respiration, independently of mitochondrial biogenesis. Consequently, liver-specific knockout mice are protected against high fat diet-induced steatosis and metabolic dysregulation. Additionally, Mtfp1 deletion inhibits mitochondrial permeability transition pore opening in hepatocytes, conferring protection against apoptotic liver damage in vivo and ex vivo. Our work uncovers additional functions of MTFP1 in the liver, positioning this gene as an unexpected regulator of OXPHOS and a therapeutic candidate for MASLD.
    DOI:  https://doi.org/10.1038/s41467-023-44143-9
  18. Biomolecules. 2023 Dec 18. pii: 1806. [Epub ahead of print]13(12):
      Most current metabolomics studies of oral squamous cell carcinoma (OSCC) are mainly focused on identifying potential biomarkers for early screening and diagnosis, while few studies have investigated the metabolic profiles promoting metastasis. In this study, we aimed to explore the altered metabolic pathways associated with metastasis of OSCC. Here, we identified four OSCC cell models (CAL27, HN6, HSC-3, SAS) that possess different invasive heterogeneity via the transwell invasion assay and divided them into high-invasive (HN6, SAS) and low-invasive (CAL27, HSC-3) cells. Quantitative analysis and stable isotope tracing using [U-13C6] glucose were performed to detect the altered metabolites in high-invasive OSCC cells, low-invasive OSCC cells and normal human oral keratinocytes (HOK). The metabolic changes in the high-invasive and low-invasive cells included elevated glycolysis, increased fatty acid metabolism and an impaired TCA cycle compared with HOK. Moreover, pathway analysis demonstrated significant differences in fatty acid biosynthesis; arachidonic acid (AA) metabolism; and glycine, serine and threonine metabolism between the high-invasive and low-invasive cells. Furthermore, the high-invasive cells displayed a significant increase in the percentages of 13C-glycine, 13C-palmitate, 13C-stearic acid, 13C-oleic acid, 13C-AA and estimated FADS1/2 activities compared with the low-invasive cells. Overall, this exploratory study suggested that the metabolic differences related to the metastatic phenotypes of OSCC cells were concentrated in glycine metabolism, de novo fatty acid synthesis and polyunsaturated fatty acid (PUFA) metabolism, providing a comprehensive understanding of the metabolic alterations and a basis for studying related molecular mechanisms in metastatic OSCC cells.
    Keywords:  metastasis; oral squamous cell carcinoma cells; quantitative metabolomics; stable isotope tracing
    DOI:  https://doi.org/10.3390/biom13121806
  19. Biology (Basel). 2023 Nov 26. pii: 1467. [Epub ahead of print]12(12):
      Ketone bodies serve several functions in the intestinal epithelium, such as stem cell maintenance, cell proliferation and differentiation, and cancer growth. Nevertheless, there is limited understanding of the mechanisms governing the regulation of intestinal ketone body concentration. In this study, we elucidated the factors responsible for ketone body production and excretion using shRNA-mediated or pharmacological inhibition of specific genes or functions in the intestinal cells. We revealed that a fasting-mimicked culture medium, which excluded glucose, pyruvate, and glutamine, augmented ketone body production and excretion in the Caco2 and HT29 colorectal cells. This effect was attenuated by glucose or glutamine supplementation. On the other hand, the inhibition of the mammalian target of rapamycin complex1 (mTORC1) recovered a fraction of the excreted ketone bodies. In addition, the pharmacological or shbeclin1-mediated inhibition of autophagy suppressed ketone body excretion. The knockdown of basigin, a transmembrane protein responsible for targeting monocarboxylate transporters (MCTs), such as MCT1 and MCT4, suppressed lactic acid and pyruvic acid excretion but increased ketone body excretion. Finally, we found that MCT7 (SLC16a6) knockdown suppressed ketone body excretion. Our findings indicate that the mTORC1-autophagy axis and MCT7 are potential targets to regulate ketone body excretion from the intestinal epithelium.
    Keywords:  autophagy; intestinal cell; ketone body; mTORC1; solute carrier family 16 member 6: SLC16a6 (MCT7)
    DOI:  https://doi.org/10.3390/biology12121467
  20. Biochim Biophys Acta Rev Cancer. 2023 Dec 13. pii: S0304-419X(23)00200-7. [Epub ahead of print] 189051
      This review delves into the most recent research on the metabolic adaptability of cancer cells and examines how their metabolic functions can impact their progression into metastatic forms. We emphasize the growing significance of lipid metabolism and dietary lipids within the tumor microenvironment, underscoring their influence on tumor progression. Additionally, we present an outline of the interplay between metabolic processes and the epigenome of cancer cells, underscoring the importance regarding the metastatic process. Lastly, we examine the potential of targeting metabolism as a therapeutic approach in combating cancer progression, shedding light on innovative drugs/targets currently undergoing preclinical evaluation.
    Keywords:  Epigenetics; Lipid metabolism; Metastasis; Microenvironment; Therapies
    DOI:  https://doi.org/10.1016/j.bbcan.2023.189051
  21. Cells. 2023 Dec 06. pii: 2777. [Epub ahead of print]12(24):
      Tamoxifen-resistant breast cancer cells (TamR-BCCs) are characterized by an enhanced metabolic phenotype compared to tamoxifen-sensitive cells. FoxO3a is an important modulator of cell metabolism, and its deregulation has been involved in the acquisition of tamoxifen resistance. Therefore, tetracycline-inducible FoxO3a was overexpressed in TamR-BCCs (TamR/TetOn-AAA), which, together with their control cell line (TamR/TetOn-V), were subjected to seahorse metabolic assays and proteomic analysis. FoxO3a was able to counteract the increased oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) observed in TamR by reducing their energetic activity and glycolytic rate. FoxO3a caused glucose accumulation, very likely by reducing LDH activity and mitigated TamR biosynthetic needs by reducing G6PDH activity and hindering NADPH production via the pentose phosphate pathway (PPP). Proteomic analysis revealed a FoxO3a-dependent marked decrease in the expression of LDH as well as of several enzymes involved in carbohydrate metabolism (e.g., Aldolase A, LDHA and phosphofructokinase) and the analysis of cBioPortal datasets of BC patients evidenced a significant inverse correlation of these proteins and FoxO3a. Interestingly, FoxO3a also increased mitochondrial biogenesis despite reducing mitochondrial functionality by triggering ROS production. Based on these findings, FoxO3a inducing/activating drugs could represent promising tools to be exploited in the management of patients who are refractory to antiestrogen therapy.
    Keywords:  FoxO3a; breast cancer; cancer metabolism; glycolysis; tamoxifen resistance
    DOI:  https://doi.org/10.3390/cells12242777
  22. Nutr Rev. 2023 Dec 18. pii: nuad152. [Epub ahead of print]
      OBJECTIVES: A comprehensive review of the current literature was conducted to summarize the potential therapeutic and management roles of ketogenic diet (KD) for cardiovascular disease (CVD).BACKGROUND: Consensus has not been reached on the optimal diet for individuals with cardiovascular risk factors. KDs are characterized by high-fat, low-carbohydrate, and appropriate protein content, and have gained popularity in recent years in the management of various conditions, including cardiovascular and metabolic diseases.
    METHODS: Original research, systematic reviews, and meta-analyses available in the PubMed, Web of Science, and Google Scholar databases were reviewed.
    RESULTS: The current body of preclinical and clinical evidence on the efficacy of KD in the management of CVD remains limited. Specific applications of KD seem to suggest a positive impact on management of CVD. However, conflicting results and a lack of precise molecular and biochemical mechanisms of action provide ample opportunity for future investigation.
    CONCLUSION: More multidisciplinary studies are needed to determine the true clinical benefit of KD in the management of CVD and so justify its expanded clinical use.
    Keywords:  atherosclerosis; cardiovascular diseases; ketogenic diet; life style; nutrition
    DOI:  https://doi.org/10.1093/nutrit/nuad152
  23. Nanoscale Adv. 2023 Dec 19. 6(1): 209-220
      Mechanical cues in the tumor microenvironment interplay with internal cellular processes to control cancer cell migration. Microscale pores present in tumor tissue confer varying degrees of confinement on migrating cells, increasing matrix contact and inducing cytoskeletal rearrangement. Previously, we observed that increased collagen matrix contact significantly increased cell migration speed and cell-induced strains within the matrix. However, the effects of this confinement on future cell migration are not fully understood. Here, we use a collagen microtrack platform to determine the effect of confinement on priming MDA-MB-231 cancer cells for fast migration. We show that migration through a confined track results in increased speed and accumulation of migratory machinery, including actin and active mitochondria, in the front of migrating breast cancer cells. By designing microtracks that allow cells to first navigate a region of high confinement, then a region of low confinement, we assessed whether migration in high confinement changes future migratory behavior. Indeed, cells maintain their speed attained in high confinement even after exiting to a region of low confinement, indicating that cells maintain memory of previous matrix cues to fuel fast migration. Active mitochondria maintain their location at the front of the cell even after cells leave high confinement. Furthermore, knocking out vinculin to disrupt focal adhesions disrupts active mitochondrial localization and disrupts the fast migration seen upon release from confinement. Together, these data suggest that active mitochondrial localization in confinement may facilitate fast migration post-confinement. By better understanding how confinement contributes to future cancer cell migration, we can identify potential therapeutic targets to inhibit breast cancer metastasis.
    DOI:  https://doi.org/10.1039/d3na00478c
  24. Magn Reson Med. 2023 Dec 19.
      PURPOSE: Nonalcoholic fatty liver disease is an important cause of chronic liver disease. There are limited methods for monitoring metabolic changes during progression to steatohepatitis. Hyperpolarized 13 C MRSI (HP 13 C MRSI) was used to measure metabolic changes in a rodent model of fatty liver disease.METHODS: Fifteen Wistar rats were placed on a methionine- and choline-deficient (MCD) diet for 1-18 weeks. HP 13 C MRSI, T2 -weighted imaging, and fat-fraction measurements were obtained at 3 T. Serum aspartate aminotransaminase, alanine aminotransaminase, and triglycerides were measured. Animals were sacrificed for histology and measurement of tissue lactate dehydrogenase (LDH) activity.
    RESULTS: Animals lost significant weight (13.6% ± 2.34%), an expected characteristic of the MCD diet. Steatosis, inflammation, and mild fibrosis were observed. Liver fat fraction was 31.7% ± 4.5% after 4 weeks and 22.2% ± 4.3% after 9 weeks. Lactate-to-pyruvate and alanine-to-pyruvate ratios decreased significantly over the study course; were negatively correlated with aspartate aminotransaminase and alanine aminotransaminase (r = -[0.39-0.61]); and were positively correlated with triglycerides (r = 0.59-0.60). Despite observed decreases in hyperpolarized lactate signal, LDH activity increased by a factor of 3 in MCD diet-fed animals. Observed decreases in lactate and alanine hyperpolarized signals on the MCD diet stand in contrast to other studies of liver injury, where lactate and alanine increased. Observed hyperpolarized metabolite changes were not explained by alterations in LDH activity, suggesting that changes may reflect co-factor depletion known to occur as a result of oxidative stress in the MCD diet.
    CONCLUSION: HP 13 C MRSI can noninvasively measure metabolic changes in the MCD model of chronic liver disease.
    Keywords:  NASH; dynamic nuclear polarization; fatty liver; hyperpolarized carbon; methionine choline deficiency; oxidative stress
    DOI:  https://doi.org/10.1002/mrm.29954
  25. Biomedicines. 2023 Nov 26. pii: 3149. [Epub ahead of print]11(12):
      The use of hypoxic devices among athletes who train in normobaric hypoxia has become increasingly popular; however, the acute effects on heart and brain metabolism are not yet fully understood. This study aimed to investigate the mitochondrial bioenergetics in trained male and female Wistar rats after acute hypoxia training. The experimental plan included exercising for 30 min on a treadmill in a Plexiglas cage connected to a hypoxic generator set at 12.5% O2 or in normoxia. After the exercise, the rats were sacrificed, and their mitochondria were isolated from their brains and hearts. The bioenergetics for each complex of the electron transport chain was tested using a Clark-type electrode. The results showed that following hypoxia training, females experienced impaired oxidative phosphorylation through complex II in heart subsarcolemmal mitochondria, while males had an altered ADP/O in heart interfibrillar mitochondria, without any change in oxidative capacity. No differences from controls were evident in the brain, but an increased electron transport system efficiency was observed with complex I and IV substrates in males. Therefore, the study's findings suggest that hypoxia training affects the heart mitochondria of females more than males. This raises a cautionary flag for female athletes who use hypoxic devices.
    Keywords:  brain; heart; hypoxia; mitochondrial bioenergetics
    DOI:  https://doi.org/10.3390/biomedicines11123149
  26. J Biol Chem. 2023 Nov 22. pii: S0021-9258(23)02498-5. [Epub ahead of print]300(1): 105470
      The prevailing notion that reduced cofactors NADH and FADH2 transfer electrons from the tricarboxylic acid cycle to the mitochondrial electron transfer system creates ambiguities regarding respiratory Complex II (CII). CII is the only membrane-bound enzyme in the tricarboxylic acid cycle and is part of the electron transfer system of the mitochondrial inner membrane feeding electrons into the coenzyme Q-junction. The succinate dehydrogenase subunit SDHA of CII oxidizes succinate and reduces the covalently bound prosthetic group FAD to FADH2 in the canonical forward tricarboxylic acid cycle. However, several graphical representations of the electron transfer system depict FADH2 in the mitochondrial matrix as a substrate to be oxidized by CII. This leads to the false conclusion that FADH2 from the β-oxidation cycle in fatty acid oxidation feeds electrons into CII. In reality, dehydrogenases of fatty acid oxidation channel electrons to the Q-junction but not through CII. The ambiguities surrounding Complex II in the literature and educational resources call for quality control, to secure scientific standards in current communications of bioenergetics, and ultimately support adequate clinical applications. This review aims to raise awareness of the inherent ambiguity crisis, complementing efforts to address the well-acknowledged issues of credibility and reproducibility.
    Keywords:  Complex II; coenzyme Q; electron transfer system; fatty acid oxidation; flavin adenine dinucleotide; succinate dehydrogenase; tricarboxylic acid cycle
    DOI:  https://doi.org/10.1016/j.jbc.2023.105470
  27. FEBS Lett. 2023 Dec 23.
      Redox and metabolic processes are tightly coupled in both physiological and pathological conditions. In cancer, their integration occurs at multiple levels and is characterised by synchronised reprogramming both in the tumour tissue and its specific but heterogeneous microenvironment. In breast cancer, the principal microenvironment is the cancer-associated adipose tissue (CAAT). Understanding how the redox-metabolic reprogramming becomes coordinated in human breast cancer is imperative both for cancer prevention and for the establishment of new therapeutic approaches. This review aims to provide an overview of the current knowledge of the redox profiles and regulation of intermediary metabolism in breast cancer whilst considering the tumour and CAAT of breast cancer as a unique Warburg's pseudo-organ. As cancer is now recognised as a systemic metabolic disease, we have paid particular attention to the cell-specific redox-metabolic reprogramming and the roles of estrogen receptors and circadian rhythms, as well as their crosstalk in the development, growth, progression, and prognosis of breast cancer.
    Keywords:  adipose tissue; breast cancer; circadian rhythms; estrogen; redox-metabolic reprogramming; tumour microenvironment
    DOI:  https://doi.org/10.1002/1873-3468.14794
  28. Sci Rep. 2023 Dec 16. 13(1): 22383
      Artesunate is a derivative of artemisinin, an active compound isolated from Artemisia annua which has been used in Traditional Chinese Medicine and to treat malaria worldwide. Artemisinin derivatives have exhibited anti-cancer activity against both solid tumors and leukemia. The direct target(s) of artesunate are controversial; although, heme-bound proteins in the mitochondria have been implicated. We utilized computational modeling to calculate the predicted binding score of artesunate with heme-bound mitochondrial proteins and identified cytochrome c as potential artesunate target. UV-visible spectroscopy showed changes in the absorbance spectrum, and thus protein structure, when cytochrome c was incubated with artesunate. Artesunate induces apoptosis, disrupts mitochondrial membrane potential, and is antagonized by methazolamide in pediatric AML cells indicating a probable mechanism of action involving cytochrome c. We utilized a multi-disciplinary approach to show that artesunate can interact with and is dependent on cytochrome c release to induce cell death in pediatric AML cell lines.
    DOI:  https://doi.org/10.1038/s41598-023-49928-y
  29. Curr Oncol. 2023 Dec 12. 30(12): 10410-10436
      FMS-like tyrosine kinase 3 (FLT3) mutations are detected in approximately 20-30% of patients with acute myeloid leukemia (AML), with the presence of a FLT3 internal tandem duplication (FLT3-ITD) mutation being associated with an inferior outcome. Assessment of FLT3 mutational status is now essential to define optimal upfront treatment in both newly diagnosed and relapsed AML, to support post-induction allogeneic hematopoietic stem cell transplantation (alloSCT) decision-making, and to evaluate treatment response via measurable (minimal) residual disease (MRD) evaluation. In view of its importance in AML diagnosis and management, the Canadian Leukemia Study Group/Groupe canadien d'étude sur la leucémie (CLSG/GCEL) undertook the development of a consensus statement on the clinical utility of FLT3 mutation testing, as members reported considerable inter-center variability across Canada with respect to testing availability and timing of use, methodology, and interpretation. The CLSG/GCEL panel identified key clinical and hematopathological questions, including: (1) which patients should be tested for FLT3 mutations, and when?; (2) which is the preferred method for FLT3 mutation testing?; (3) what is the clinical relevance of FLT3-ITD size, insertion site, and number of distinct FLT3-ITDs?; (4) is there a role for FLT3 analysis in MRD assessment?; (5) what is the clinical relevance of the FLT3-ITD allelic burden?; and (6) how should results of FLT3 mutation testing be reported? The panel followed an evidence-based approach, taken together with Canadian clinical and laboratory experience and expertise, to create a consensus document to facilitate a more uniform approach to AML diagnosis and treatment across Canada.
    Keywords:  FLT3 testing; FLT3-ITD; FLT3-TKD; acute myeloid leukemia; allelic ratio; fragment analysis; next-generation sequencing
    DOI:  https://doi.org/10.3390/curroncol30120759
  30. Mol Hum Reprod. 2023 Dec 21. pii: gaad049. [Epub ahead of print]
      Oxygen (O2) concentrations have recently been discussed as important regulators of ovarian cells. Human IVF-derived granulosa cells (human GCs) can be maintained in vitro and are a widely used cellular model for the human ovary. Typically, GCs are cultured at atmospheric O2 levels (approximately around 20%), yet the O2 conditions in vivo, especially in the preovulatory follicle, are estimated to be much lower. Therefore, we comprehensively evaluated the consequences of atmospheric versus hypoxic (1% O2) conditions for 4 days on human GCs. We found lower cellular RNA and protein levels but unchanged cell numbers at 1% O2, indicating reduced transcriptional and/or translational activity. A proteomic analysis showed that 391 proteins were indeed decreased, yet 133 proteins were increased under hypoxic conditions. According to gene ontology GO enrichment analysis, pathways associated with metabolic processes, for example amino acid-catabolic-processes, mitochondrial protein biosynthesis, and steroid biosynthesis, were down-regulated. Pathways associated with glycolysis, chemical homeostasis, cellular response to hypoxia and actin filament bundle assembly were up-regulated. In accordance with lower CYP11A1 (a cholesterol side-chain cleavage enzyme) levels, progesterone release was decreased. A proteome profiler, as well as IL-6 and IL-8 ELISA assays, revealed that hypoxia led to increased secretion of pro-inflammatory and angiogenic factors. Immunofluorescence studies showed nuclear localization of hypoxia-inducible factor 1α (HIF1α) in human GCs upon acute (2-4 h) exposure to 1% O2 but not in cells exposed to 1% O2 for 4 days. Hence the role of HIF1α may be restricted to initiation of the hypoxic response in human GCs. The results provide a detailed picture of hypoxia-induced phenotypic changes in human GCs and reveal that chronically low O2 conditions inhibit the steroidogenic, but promote the inflammatory phenotype of these cells.
    Keywords:  cell culture; hypoxia; inflammation; ovary; proteomic analysis
    DOI:  https://doi.org/10.1093/molehr/gaad049
  31. Ann Med. 2023 ;55(2): 2281662
      Colorectal cancer (CRC) is one of the most common cancers worldwide and it involves various biomolecular and cellular levels. CRC has possibly happened due to aging, urbanization, and diet. Different foods have varying effects on the gastrointestinal cells, that's why additional research is necessary to create effective medical interventions. This review aimed to evaluate the correlation between dietary and nutritional status on the outcome of CRC patients. Study results showed that a healthy diet such as fruit and vegetables is the best diet for improving colorectal cancer outcomes. Moreover, nutritional status affected CRC patients' outcomes, where high BMI increases the risk of having CRC. However, low BMI was associated with CRC progression and poor quality of life.
    Keywords:  Colorectal cancer; dietary; nutritional status
    DOI:  https://doi.org/10.1080/07853890.2023.2281662
  32. Anal Biochem. 2023 Dec 20. pii: S0003-2697(23)00410-4. [Epub ahead of print] 115445
      REAP+ is an enhanced version of the rapid, efficient, and practical (REAP) method designed for the isolation of nuclear fractions. This improved version, REAP+, enables fast and effective extraction of mitochondria, cytoplasm, and nuclei. The mechanical cell disruption process has been optimized to cerebral tissues, snap-frozen liver, and HT22 cells with remarkable fraction enrichment. REAP+ is well-suited for samples containing minimal protein quantities, such as mouse hippocampal slices. The method was validated by Western blot and marker enzyme activities, such as LDH and G6PDH for the cytoplasmic fraction and succinate dehydrogenase and cytochrome c oxidase for the mitochondrial fraction. One of the outstanding features of this method is its rapid execution, yielding fractions within 15 min, allowing for simultaneous preparation of multiple samples. In essence, REAP + emerges as a swift, efficient, and practical technique for the concurrent isolation of nuclei, cytoplasm, and mitochondria from various cell types and tissues. The method would be suitable to study the multicompartment translocation of proteins, such as metabolic enzymes and transcription factors migrating from cytosol to the mitochondria and nuclei. Moreover, its compatibility with small samples, such as hippocampal slices, and its potential applicability to human biopsies, highlights the potential application in medical research.
    Keywords:  Mitochondrial enrichment; Nuclear extract; Organelle-specific fractionation; REAP+; Subcellular fractionation
    DOI:  https://doi.org/10.1016/j.ab.2023.115445
  33. Nutrition. 2023 Oct 31. pii: S0899-9007(23)00312-X. [Epub ahead of print]119 112284
      OBJECTIVE: The aim of this study was to explore the effect of the ketogenic diet (KD) on β-cell dedifferentiation and hepatic lipid accumulation in db/db mice.METHODS: After a 3-wk habituation, male db/db mice ages 8 wk were assigned into one of three groups: normal diet (ND), KD, and 75% calorie restriction (CR) group. Free access to a standard diet, a KD, and 75% of a standard diet, respectively, were given to each group. Additionally, sex-matched 8-wk-old C57BL/6 mice were used to construct a control (C) group. After a 4-wk dietary intervention, mouse body weight, fasting blood glucose (FBG), blood lipids, fasting insulin (FINS), glucose tolerance, and β-hydroxybutyric acid level were measured. The morphologies of the islet and liver were observed by hematoxylin and eosin staining. Positive expressions of β-cell-specific transcription factors in mouse islets were determined by double immunofluorescence staining. The size and number of lipid droplets in mouse liver were examined by Oil Red O staining. Real-time quantitative reverse transcription polymerase chain reaction detected relative levels of adipogenesis-associated and lipolysis-associated genes in mouse liver. Additionally, expressions of CD36 protein in the mouse liver were determined by immunohistochemical staining and Western blot.
    RESULTS: After a 4-wk dietary intervention, FBG, FINS, and glucose area under the curve in the KD group became significantly lower than in the ND group (all P < 0.05). Regular morphology of mouse islets was observed in the KD group, with an increased number of islet cells. The KD significantly reversed the decrease in β-cell number, disarrangement of β-cells, decline of β/α-cell ratio, and downregulation of β-cell-specific transcription factors in db/db mice. Serum levels of triacylglycerol, total cholesterol, and low-density lipoprotein cholesterol were comparable between the ND and KD groups. In contrast, serum triacylglycerol levels were significantly lower in the CR group than in the ND group (P < 0.05). Vacuolar degeneration and lipid accumulation in the liver were more prominent in the KD group than in the ND and CR groups. The mRNA levels of Pparα and Acox1 in the KD group were lower than those in the ND group, although no significant differences were detected. Relative levels of Cd36 and inflammatory genes in the mouse liver were significantly higher in the KD group than in the ND group (all P < 0.05).
    CONCLUSION: The KD significantly reduced FBG and FINS and improved glucose tolerance in db/db mice by upregulating β-cell-specific transcription factors and reversing β-cell dedifferentiation. However, the KD also induced hepatic lipid accumulation and aggravated inflammatory response in the liver of db/db mice.
    Keywords:  Hepatic lipid accumulation; Ketogenic diet; Type 2 diabetes mellitus; β-cell dedifferentiation
    DOI:  https://doi.org/10.1016/j.nut.2023.112284
  34. bioRxiv. 2023 Dec 07. pii: 2023.12.06.570456. [Epub ahead of print]
      Dietary protein and essential amino acid (EAA) restriction promotes favorable metabolic reprogramming, ultimately resulting in improvements to both health and lifespan. However, as individual EAAs have distinct catabolites and engage diverse downstream signaling pathways, it remains unclear to what extent shared or AA-specific molecular mechanisms promote diet-associated phenotypes. Here, we investigated the physiological and molecular effects of restricting either dietary methionine, leucine, or isoleucine (Met-R, Leu-R, and Ile-R) for 3 weeks in C57BL/6J male mice. While all 3 AA-depleted diets promoted fat and lean mass loss and slightly improved glucose tolerance, the molecular responses were more diverse; while hepatic metabolites altered by Met-R and Leu-R were highly similar, Ile-R led to dramatic changes in metabolites, including a 3-fold reduction in the oncometabolite 2-hydroxyglutarate. Pathways regulated in an EAA-specific manner included glycolysis, the pentose phosphate pathway (PPP), nucleotide metabolism, the TCA cycle and amino acid metabolism. Transcriptiome analysis and global profiling of histone post-translational modifications (PTMs) revealed different patterns of responses to each diet, although Met-R and Leu-R again shared similar transcriptional responses. While the pattern of global histone PTMs were largely unique for each dietary intervention, Met-R and Ile-R had similar changes in histone-3 methylation/acetylation PTMs at lysine-9. Few similarities were observed between the physiological or molecular responses to EAA restriction and treatment with rapamycin, an inhibitor of the mTORC1 AA-responsive protein kinase, indicating the response to EAA restriction may be largely independent of mTORC1. Together, these results demonstrate that dietary restriction of individual EAAs has unique, EAA-specific effects on the hepatic metabolome, epigenome, and transcriptome, and suggests that the specific EAAs present in dietary protein may play a key role at regulating health at the molecular level.
    DOI:  https://doi.org/10.1101/2023.12.06.570456
  35. Nutrients. 2023 Dec 11. pii: 5068. [Epub ahead of print]15(24):
      Throughout their experience of illness and during the course of treatment, a substantial proportion of cancer patients are prone to develop nutritional and/or metabolic disturbances. Additionally, cancer patients often encounter long-term side effects from therapies, which may lead to impaired digestion, nutrient absorption or bowel motility. Therefore, the preservation and maintenance of an optimal and balanced nutritional status are pivotal to achieving a better prognosis, increasing the tolerance and adherence to cancer therapies and improving the overall quality of life. In this context, personalized nutritional programs are essential for addressing conditions predisposing to weight loss, feeding difficulties, digestion problems and intestinal irregularity, with the goal of promoting adequate nutrient absorption and minimizing the detrimental effects of treatment regimens. The focus of this research is to examine the most common clinical conditions and metabolic changes that cancer patients may experience, including stomatitis, xerostomia, diarrhea, nausea, vomiting, dysphagia, sub-occlusion, dysgeusia, dysosmia, anorexia, and cachexia. Furthermore, we present a pragmatic example of a multidisciplinary workflow that incorporates customized recipes tailored to individual clinical scenarios, all while maintaining the hedonic value of the meals.
    Keywords:  anorexia; cachexia; cancer; diarrhea; dysphagia; nausea; nutrition; stomatitis; vomiting; xerostomia
    DOI:  https://doi.org/10.3390/nu15245068
  36. Cancers (Basel). 2023 Dec 16. pii: 5870. [Epub ahead of print]15(24):
      Fasting mimicking diets (FMDs) are effective in the treatment of many solid tumors in mouse models, but their effect on hematologic malignancies is poorly understood, particularly in combination with standard therapies. Here we show that cycles of a 3-day FMD given to high-fat-diet-fed mice once a week increased the efficacy of vincristine to improve survival from BCR-ABL B acute lymphoblastic leukemia (ALL). In mice fed a standard diet, FMD cycles in combination with vincristine promoted cancer-free survival. RNA seq and protein assays revealed a vincristine-dependent decrease in the expression of multiple autophagy markers, which was exacerbated by the fasting/FMD conditions. The autophagy inhibitor chloroquine could substitute for fasting/FMD to promote cancer-free survival in combination with vincristine. In vitro, targeted inhibition of autophagy genes ULK1 and ATG9a strongly potentiated vincristine's toxicity. Moreover, anti-CD8 antibodies reversed the effects of vincristine plus fasting/FMD in promoting leukemia-free survival in mice, indicating a central role of the immune system in this response. Thus, the inhibition of autophagy and enhancement of immune responses appear to be mediators of the fasting/FMD-dependent cancer-free survival in ALL mice.
    Keywords:  Leukemia; autophagy; cancer treatment; fasting-mimicking diet; pre-B-ALL
    DOI:  https://doi.org/10.3390/cancers15245870