Increased Glucose Uptake Research Articles

Abstract IA005: PET imaging predictors of response to chemoradiotherapy in cervical cancer

Abstract Although HPV transformed tumors are presumed to be radiation sensitive, approximately one third of locally advanced cervical cancer patients fail the current standard of care (concurrent cisplatin and radiation therapy). Work in our laboratory has combined the results of functional imaging with 18F-fluoro-deoxy-glucose positron emission tomography (FDG-PET) imaging together with bioinformatic analyses of associated translational correlates to define new predictors of resistance to DNA damaging therapies. Results of this work demonstrate that cervical tumors with increased FDG uptake on pretreatment FDG-PET imaging are characterized by myeloid predominant inflammatory infiltrates, including immature monocytes and macrophages. Co-culture of cervical tumor cells with macrophages is associated with increased glucose uptake and pro-survival signaling in tumor cells mediated through macrophage derived IL-6 and signaling through the JAK-STAT pathway. We are currently using a combination of single cell sequencing and spatially resolved approaches to further define PET associated and chemoradiation induced changes in cervix tumor cell metabolism and the immune tumor microenvironment with the goal of defining new targets for personalized therapies. Importantly, cervical cancers retain and transcribe portions of the HPV genome. At the end of the talk, we will review recent work in our lab that highlights the impact of HPV associated gene expression, including splice variants, on the response to DNA damaging agents. Citation Format: Julie K. Schwarz. PET imaging predictors of response to chemoradiotherapy in cervical cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: DNA Damage Repair: From Basic Science to Future Clinical Application; 2024 Jan 9-11; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2024;84(1 Suppl):Abstract nr IA005.

Mimicking CHO large-scale effects in the single multicompartment bioreactor: A new approach to access scale-up behavior.

During the scale-up of biopharmaceutical production processes, insufficiently predictable performance losses may occur alongside gradients and heterogeneities. To overcome such performance losses, tools are required to explain, predict, and ultimately prohibit inconsistencies between laboratory and commercial scale. In this work, we performed CHO fed-batch cultivations in the single multicompartment bioreactor (SMCB), a new scale-down reactor system that offers new access to study large-scale heterogeneities in mammalian cell cultures. At volumetric power inputs of 20.4-1.5 W m-3, large-scale characteristics like long mixing times and dissolved oxygen (DO) heterogeneities were mimicked in the SMCB. Compared to a reference bioreactor (REFB) set-up, the conditions in the SMCB provoked an increase in lactate accumulation of up to 87%, an increased glucose uptake, and reduced viable cell concentrations in the stationary phase. All are characteristic for large-scale performance. The unique possibility to distinguish between the effects of changing power inputs and observed heterogeneities provided new insights into the potential reasons for altered product quality attributes. Apparently, the degree of galactosylation in the evaluated glycan patterns changed primarily due to the different power inputs rather than the provoked heterogeneities. The SMCB system could serve as a potent tool to provide new insights into scale-up behavior and to predict cell line-specific drawbacks at an early stage of process development.

S100A9 exerts insulin-independent antidiabetic and anti-inflammatory effects.

Type 1 diabetes mellitus (T1DM) is characterized by insulin deficiency leading to hyperglycemia and several metabolic defects. Insulin therapy remains the cornerstone of T1DM management, yet it increases the risk of life-threatening hypoglycemia and the development of major comorbidities. Here, we report an insulin signaling-independent pathway able to improve glycemic control in T1DM rodents. Co-treatment with recombinant S100 calcium-binding protein A9 (S100A9) enabled increased adherence to glycemic targets with half as much insulin and without causing hypoglycemia. Mechanistically, we demonstrate that the hyperglycemia-suppressing action of S100A9 is due to a Toll-like receptor 4-dependent increase in glucose uptake in specific skeletal muscles (i.e., soleus and diaphragm). In addition, we found that T1DM mice have abnormal systemic inflammation, which is resolved by S100A9 therapy alone (or in combination with low insulin), hence uncovering a potent anti-inflammatory action of S100A9 in T1DM. In summary, our findings reveal the S100A9-TLR4 skeletal muscle axis as a promising therapeutic target for improving T1DM treatment.

Hydroxyhydroquinone and Quassinoids as Promising Compounds with Hypoglycemic Activity through Redox Balance

In the present study, an insulin-resistant cell model (human hepatocellular carcinoma cell line: HepG2) was chosen to investigate the efficacy of two compound classes and their common molecular motif for glycemic control and insulin sensitization. The two compounds’ classes were flavonoid extracts from Rourea cuspidata and quassinoid extracts from Picrasma crenata. The flavonoid-like hydroxyhydroquinone (HHQ) was synthesized. HepG2 cells were tested in a high-glucose environment (HepG2/IRM) by monitoring ROS activity, the concentration of adenosine triphosphate (ATP), and the measurement of mitochondrial membrane potential (MMP). The expression of forkhead box O1 (FOXO1) protein, which mediates gluconeogenesis and insulin resistance, was also investigated using indirect immunocytochemistry and Western blot techniques. A significant increase in glucose uptake and well-regulated ATP concentrations were observed in the treated cells. The downregulation of FOXO1 expression was seen in cells treated with HHQ and quassinoids in comparison to cells treated with flavonoids. This study provides a pharmacological basis for the application of HHQ, quassinoids from P. crenata, and flavonoids from R. cuspidata in the treatment of metabolic diseases such as type 2 diabetes mellitus.

The AMPK and AKT/GSK3β pathways are involved in recombinant proteins fibroblast growth factor 1 (rFGF1 and rFGF1a) improving glycolipid metabolism in rainbow trout (Oncorhynchus mykiss) fed a high carbohydrate diet

Fibroblast growth factor 1 (FGF1) regulates vertebrate cell growth, proliferation and differentiation, and energy metabolism. In this study, we cloned rainbow trout (Oncorhynchus mykiss) fgf1 and fgf1a, prepared their recombinant proteins (rFGF1 and rFGF1a), and described the molecular mechanisms by which they improve glycolipid metabolism in carnivorous fish. A 31-d feeding trial was conducted to investigate whether they could enhance glycolipid metabolism in rainbow trout on high-carbohydrate diets (HCD). A total of 720 rainbow trout (8.9 ± 0.5 g) were equally divided into 4 groups: the chow diet (CD) group injected with PBS, the HCD group injected with PBS, the HCD group injected with rFGF1 (400 ng/g body weight), and the HCD group injected with rFGF1a (400 ng/g body weight). The results showed that short-term HCD had a significant positive effect on the specific growth rate (SGR) of rainbow trout (P < 0.05). However, it led to an increase in crude fat, serum triglyceride (TG) and glucose content, as well as serum glutamic pyruvic transaminase (GPT) and glutamic oxalacetic transaminase (GOT) contents (P < 0.05), suggesting a negative health effect of HCD. Nevertheless, rFGF1 and rFGF1a showed beneficial therapeutic effects. They significantly reduced the crude fat content of the liver, serum TG, GOT, and GPT contents caused by HCD (P < 0.05). The upregulation in atgl, hsl, and acc2 mRNAs implied the promotion of TG catabolism. Moreover, rFGF1 and rFGF1a contributed to promoting lipolysis by activating the AMPK pathway and reducing lipid accumulation in the liver caused by HCD. In addition, the rFGF1 and rFGF1a-treated groups significantly reduced serum glucose levels and elevated hepatic glycogen content under HCD, and increased glucose uptake by hepatocytes. We observed a decrease in mRNA levels for pepck, g6pase, and pygl, along with an increase in mRNA levels for gys, glut2, and gk in the liver. Furthermore, these proteins regulated hepatic gluconeogenesis and glycogen synthesis by increasing the phosphorylation level of AKT, ultimately leading to an increase in GSK3β phosphorylation. In conclusion, this study demonstrates that rFGF1 and rFGF1a can enhance lipolysis and glucose utilization in rainbow trout by activating the AMPK pathway and AKT/GSK3β axis.

Insulinotropic effect of Teucrium polium; Identification of potential mechanistic drug targets

Teucrium polium (T. polium), commonly known as golden germander, is a herb that grows in the Mediterranean region and is used by the locals to treat diabetes mellitus. The glucose-lowering effect of T. polium is well established in rodents. This study aims to examine whether the glucose-lowering effect is by inducing the release of insulin from pancreatic beta cells and to identify key measurable biomolecules/sites that are modified in the lead-up to insulin release. Insulin secretion was examined in BRIN-BD11 pancreatic beta cells treated with T. polium extract in vitro and key flavonoids were identified using LCMS. The T. polium extract promoted increased insulin secretion (p&lt;0.05), in a dose-dependent manner, and increased glucose uptake (p&lt;0.05) within 30min. This was accompanied by an increase in GLUT2 (p&lt;0.05) and glucokinase (p&lt;0.01) expression. Also, mitochondrial metabolism and glycolytic rates were enhanced (p&lt;0.05), and ATP production increased (p&lt;0.01), which coincided with increased (p&lt;0.01) calcium influx. Rutin and apigenin were detected, but not quercetin, in this extract. T. polium promotes insulin secretion. T. polium does this by GLUT2 and glucokinase expression, increased glucose transport, metabolism and ATP production, ultimately increasing intracellular calcium. Keywords: Diabetes mellitus, phenolics, flavonoids, hyperglycaemia, glucose lowering, insulin secretagogue, pancreatic beta cells.

Glucolipotoxicity: A Novel Different Perspective on the Causes of Cancer

The Warburg effect, characterized by increased glucose uptake and lactate production in cancer cells even in the presence of oxygen, has long been recognized as a hallmark of cancer metabolism. This metabolic alteration provides cancer cells with a growth advantage, facilitating their rapid proliferation. The underlying mechanisms driving the Warburg effect involve dysregulated glucose metabolism, upregulation of glucose transporters, and metabolic reprogramming favoring glycolysis. The resulting accumulation of metabolic intermediates, such as lactate, contributes to the acidic tumor microenvironment, promoting tumor progression. However, a novel perspective proposed by Maher Akl suggests that dysregulated glycolipid metabolism, particularly the accumulation of glycolipids within cells, plays a pivotal role in tumor development. This glucolipotoxicity hypothesis offers a broader understanding of the primary causes of cancer, emphasizing the interference of accumulated glycolipids with cellular processes and the activation of oncogenic pathways. In this abstract, we summarize the mechanisms underlying the Warburg effect and glucolipotoxicity, highlighting their implications for tumor growth. Understanding these paradoxical conditions that activate tumor growth provides insights for the development of innovative therapeutic strategies targeting the primary cause of cancer.

Isthmin-1 Improves Aging-Related Cardiac Dysfunction in Mice through Enhancing Glycolysis and SIRT1 Deacetylase Activity.

Aging-related cardiac dysfunction poses a major risk factor of mortality for elderly populations, however, efficient treatment for aging-related cardiac dysfunction is far from being known. Isthmin-1 (ISM1) is a novel adipokine that promotes glucose uptake and acts indispensable roles in restraining inflammatory and fibrosis. The present study aims to investigate the potential role and molecular mechanism of ISM1 in aging-related cardiac dysfunction. Aged and matched young mice were overexpressed or silenced with ISM1 to investigate the role of ISM1 in aging-related cardiac dysfunction. Moreover, H9C2 cells were stimulated with D-galactose (D-gal) to examine the role of ISM1 in vitro. Herein, we found that cardiac-specific overexpression of ISM1 significantly mitigated insulin resistance by promoting glucose uptake in aging mice. ISM1 overexpression alleviated while ISM1 silencing deteriorated cellular senescence, cardiac inflammation, and dysfunction in natural and accelerated cardiac aging. Mechanistically, ISM1 promoted glycolysis and activated Sirtuin-1 (SIRT1) through increasing glucose uptake. ISM1 increased glucose uptake via translocating GLUT4 to the surface, thereby enhancing glycolytic flux and hexosamine biosynthetic pathway (HBP) flux, ultimately leading to increased SIRT1 activity through O-GlcNAc modification. ISM1 may serve as a novel potential therapeutic target for preventing aging-related cardiac disease in elderly populations. ISM1 prevents aging-related cardiac dysfunction by promoting glycolysis and enhancing SIRT1 deacetylase activity, making it a promising therapeutic target for aging-related cardiac disease.

Our current understanding of the biological impact of endometrial cancer mtDNA genome mutations and their potential use as a biomarker.

Endometrial cancer (EC) is a devastating and common disease affecting women's health. The NCI Surveillance, Epidemiology, and End Results Program predicted that there would be >66,000 new cases in the United States and >13,000 deaths from EC in 2023, and EC is the sixth most common cancer among women worldwide. Regulation of mitochondrial metabolism plays a role in tumorigenesis. In proliferating cancer cells, mitochondria provide the necessary building blocks for biosynthesis of amino acids, lipids, nucleotides, and glucose. One mechanism causing altered mitochondrial activity is mitochondrial DNA (mtDNA) mutation. The polyploid human mtDNA genome is a circular double-stranded molecule essential to vertebrate life that harbors genes critical for oxidative phosphorylation plus mitochondrial-derived peptide genes. Cancer cells display aerobic glycolysis, known as the Warburg effect, which arises from the needs of fast-dividing cells and is characterized by increased glucose uptake and conversion of glucose to lactate. Solid tumors often contain at least one mtDNA substitution. Furthermore, it is common for cancer cells to harbor mixtures of wild-type and mutant mtDNA genotypes, known as heteroplasmy. Considering the increase in cancer cell energy demand, the presence of functionally relevant carcinogenesis-inducing or environment-adapting mtDNA mutations in cancer seems plausible. We review 279 EC tumor-specific mtDNA single nucleotide variants from 111 individuals from different studies. Many transition mutations indicative of error-prone DNA polymerase γ replication and C to U deamination events were present. We examine the spectrum of mutations and their heteroplasmy and discuss the potential biological impact of recurrent, non-synonymous, insertion, and deletion mutations. Lastly, we explore current EC treatments, exploiting cancer cell mitochondria for therapy and the prospect of using mtDNA variants as an EC biomarker.

Metabolomic Investigations into Hypoxia-Mediated Metabolic Reprogramming of Pancreatic Cancer Cells.

Hypoxia is a crucial microenvironmental factor that defines tumor cell growth and aggressiveness. Cancer cells adapt to hypoxia by altering their metabolism. These alterations impact various cellular and physiological functions, including energy metabolism, vascularization, invasion and metastasis, genetic instability, cell immortalization, stem cell maintenance, and resistance to chemotherapy (Li et al. Technol Cancer Res Treat 20:15330338211036304, 2021). Hypoxia-inducible factor-1α (HIF-1α) is known to be a critical regulator of glycolysis that directly regulates the transcription of multiple key enzymes of the glycolysis pathway. Moreover, HIF-1α stabilization can be directly modulated by TCA-derived metabolites, including 2-ketoglutarate and succinate (Infantino et al, Int J Mol Sci 22(22), https://doi.org/10.3390/ijms22115703 , 2021). Overall, the molecular mechanisms underlying the adaptation of cellular metabolism to hypoxia impact the metabolic phenotype of cancer cells. Such adaptations include increased glucose uptake, increased lactate production, and increased levels of other metabolites that stabilize HIF-1α, leading to a vicious circle of hypoxia-induced tumor growth.

Effects of estrogens in mitochondria: An approach to type 2 diabetes

&lt;abstract&gt; &lt;p&gt;Type 2 diabetes (T2D) is characterized by a state of hyperglycemia in the blood due to insulin resistance developed by organs such as muscle, liver, and adipose tissue. A common factor in individuals with T2D is mitochondrial dysfunction. Mitochondria are dynamic organelles responsible for energy and antioxidant metabolism in the cells. Estrogens, such as 17β-estradiol (E2), are steroid hormones that have shown a great capacity to regulate mitochondrial function and dynamics through estrogen receptors (ERs), modulating the expression of mitochondrial biogenesis-related genes and cell signaling mechanisms. The accumulation of reactive oxygen species, the low capacity for ATP synthesis, and morphological alterations are some of the mitochondrial processes impaired in T2D. Insulin signaling and secretion by pancreatic β-cells, ATP-dependent processes, are also altered in T2D. In this review, mitochondria were exposed as the central axis for the action of estrogens in individuals with T2D. Estrogens increased glucose uptake, insulin signaling, and mitochondrial bioenergetics, and decreased ectopic lipid accumulation in non-adipose tissues and oxidative stress, among other processes, in various preclinical and clinical models of diabetes. The development of strategies to target compounds to mitochondria could represent a novel therapeutic alternative to potentiate the effects of estrogens on this organelle in patients with insulin resistance and T2D.&lt;/p&gt; &lt;/abstract&gt;

Excess dietary sugar impairs Drosophila adult stem cells via elevated reactive oxygen species-induced JNK signaling.

High-sugar diets (HSDs) often lead to obesity and type 2 diabetes, both metabolic syndromes associated with stem cell dysfunction. However, it is unclear whether excess dietary sugar affects stem cells. Here, we report that HSD impairs stem cell function in the intestine and ovaries of female Drosophila prior to the onset of insulin resistance, a hallmark of type 2 diabetes. Although 1 week of HSD leads to obesity, impaired oogenesis and altered lipid metabolism, insulin resistance does not occur. HSD increases glucose uptake by germline stem cells (GSCs) and triggers reactive oxygen species-induced JNK signaling, which reduces GSC proliferation. Removal of excess sugar from the diet reverses these HSD-induced phenomena. A similar phenomenon is found in intestinal stem cells (ISCs), except that HSD disrupts ISC maintenance and differentiation. Interestingly, tumor-like GSCs and ISCs are less responsive to HSD, which may be because of their dependence on glycolytic metabolism and high energy demand, respectively. This study suggests that excess dietary sugar induces oxidative stress and damages stem cells before insulin resistance develops, a mechanism that may also occur in higher organisms.

Loss of lysosomal acid lipase results in mitochondrial dysfunction and fiber switch in skeletal muscles of mice

ObjectiveLysosomal acid lipase (LAL) is the only enzyme known to hydrolyze cholesteryl esters (CE) and triacylglycerols in lysosomes at an acidic pH. Despite the importance of lysosomal hydrolysis in skeletal muscle (SM), research in this area is limited. We hypothesized that LAL may play an important role in SM development, function, and metabolism as a result of lipid and/or carbohydrate metabolism disruptions. ResultsMice with systemic LAL deficiency (Lal−/−) had markedly lower SM mass, cross-sectional area, and Feret diameter despite unchanged proteolysis or protein synthesis markers in all SM examined. In addition, Lal−/− SM showed increased total cholesterol and CE concentrations, especially during fasting and maturation. Regardless of increased glucose uptake, expression of the slow oxidative fiber marker MYH7 was markedly increased in Lal−/−SM, indicating a fiber switch from glycolytic, fast-twitch fibers to oxidative, slow-twitch fibers. Proteomic analysis of the oxidative and glycolytic parts of the SM confirmed the transition between fast- and slow-twitch fibers, consistent with the decreased Lal−/− muscle size due to the “fiber paradox”. Decreased oxidative capacity and ATP concentration were associated with reduced mitochondrial function of Lal−/− SM, particularly affecting oxidative phosphorylation, despite unchanged structure and number of mitochondria. Impairment in muscle function was reflected by increased exhaustion in the treadmill peak effort test in vivo. ConclusionWe conclude that whole-body loss of LAL is associated with a profound remodeling of the muscular phenotype, manifested by fiber type switch and a decline in muscle mass, most likely due to dysfunctional mitochondria and impaired energy metabolism, at least in mice.

GAMBARAN KEPATUHAN BEROLAHRAGA PENDERITA DIABETES MELLITUS

Exercise will lower blood glucose levels by increasing glucose uptake by muscles and improving insulin. Insulin is a hormone in the body that regulates carbohydrate metabolism and transports glucose into cells.This study aims to describe exercise adherence in people with diabetes mellitus. Methods: This research is a quantitative study with a descriptive research design. Respondents in this study were 84 people diagnosed with DM in the Simpang Tiga Health Center work area. The research samples were taken based on inclusion criteria using a purposive sampling technique. The analysis used was univariate analysis to see the frequency distribution and description of exercise adherence in DM sufferers. Results: The results of the statistical test showed that the majority of DM sufferers were aged 40-59 years (late adulthood), female, the majority worked as housewives, graduated from high school, and had suffered from DM at most 1-10 years. Conclusion: The results of this study indicate that there are more non-compliant adherents to exercise in DM sufferers than adherents.

Synthesis of milk components involves different mammary metabolism adaptations in response to net energy and protein supplies in dairy cows

Net energy for lactation (NEL) and metabolizable protein (MP) are the 2 main nutritional forces that drive synthesis of milk components. This study investigated mammary-gland metabolism in dairy cows in response to variations in the supply of NEL and MP. Four Holstein dairy cows were randomly assigned to a 4 × 4 Latin square design, in which each experimental period consisted of 14 d of dietary treatment. The diets provided 2 levels of NEL (low energy, 25.0 Mcal/d vs. high energy, 32.5 Mcal/d) and 2 levels of MP (low protein, 1,266 g/d vs. high protein, 2,254 g/d of protein digestible in the intestine) in a 2 × 2 factorial arrangement. Performance and dry matter intake (DMI) were measured during the last 5 d of each period, and the mammary net balance was measured on d 13 by collecting 6 sets of blood samples from the left carotid artery and left mammary vein. Mammary plasma flow was measured according to the Fick principle for Phe and Tyr. The mammary net balance of carbon equaled the uptake of nutrients expressed as carbon minus the output of lactose, fatty acids (FA) synthesized in the mammary gland, AA of milk protein, and glycerol-3P from triglyceride on d 13. Milk, lactose, fat, and protein yields increased when NEL and MP supplies increased. However, increasing the NEL supply increased FA synthesis more than increasing the protein supply did. In addition, FA secretion increased more than lactose secretion when the NEL supply increased. Increasing the NEL supply increased the left half-udder uptake of all major energy-yielding nutrients by increasing mammary plasma flow. However, nutrient uptake increased more than milk output did, which in turn increased carbon dioxide output. This increase in nutrient oxidation by the mammary gland decreased the mammary efficiency of nutrients utilization when the NEL supply increased. Increasing MP supply tended to increase glucose uptake through mammary clearance and increased mammary AA uptake with no change in mammary plasma flow. In addition, the protein supply did not change the mammary uptake of acetate or β-hydroxybutyrate. The increase in milk-component secretions in response to either NEL or MP supplies occurred through different metabolic adaptations (increase in mammary plasma flow vs. clearances, respectively). These results suggest that the nutrient use by the mammary gland is highly flexible, which helps in maintaining milk and milk-component yields even with limiting nutrient supplies.

The Aurora kinase inhibitor AT9283 inhibits Burkitt lymphoma growth by regulating Warburg effect

Objective To investigate the effect of the kinase inhibitor AT9283 on Burkitt lymphoma (BL) cells and elucidate the underlying mechanisms. Methods The effect of AT9283 on the proliferation of BL cell lines was tested using the MTT assay. Apoptosis and cell cycle were measured by flow cytometry. The proteins associated with the cell cycle, apoptosis, and the Warburg effect were detected using Western blotting. Alterations in glycolytic metabolism in terms of glucose intake and lactate concentrations were determined by glucose and lactate assays. Results The current study utilized the GEPIA, the Human Protein Atlas (HAP) database and immunohistochemistry to conduct analyses, which revealed a high expression of Aurora kinases and Warburg effect-related proteins in malignant B-cell lymphoma tissues. AT9283 significantly inhibited the cell proliferation of BL cells and induced G2/M arrest. Additionally, AT9283 induced apoptosis in BL cells and reversed the Warburg effect by increasing glucose uptake and reducing lactate production. Moreover, the protein expression of hexokinase 2, pyruvate kinase M2, and lactate dehydrogenase A was significantly suppressed by AT9283, possibly through the inhibition of c-Myc and HIF-1α protein expression. Conclusion The reversal of the Warburg effect in BL cells and the subsequent inhibition of cell proliferation and induction of apoptosis were observed by targeting Aurora A and Aurora B with AT9283. This finding may present new therapeutic options and targets for BL.

Deficiency of thioredoxin-interacting protein results in age-related thrombocytopenia due to megakaryocyte oxidative stress

BackgroundPlatelets are generated from megakaryocytes (MKs), mainly located in the bone marrow (BM). Megakaryopoiesis can be affected by genetic disorders, metabolic diseases, and aging. The molecular mechanisms underlying platelet count regulation have not been fully elucidated. ObjectivesIn the present study, we investigated the role of thioredoxin-interacting protein (TXNIP), a protein that regulates cellular metabolism in megakaryopoiesis, using a Txnip−/− mouse model. MethodsWild-type (WT) and Txnip−/− mice (2-27-month-old) were studied. BM-derived MKs were analyzed to investigate the role of TXNIP in megakaryopoiesis with age. The global transcriptome of BM-derived CD41+ megakaryocyte precursors (MkPs) of WT and Txnip−/− mice were compared. The CD34+ hematopoietic stem cells isolated from human cord blood were differentiated into MKs. ResultsTxnip−/− mice developed thrombocytopenia at 4 to 5 months that worsened with age. During ex vivo megakaryopoiesis, Txnip−/− MkPs remained small, with decreased levels of MK-specific markers. Critically, Txnip−/− MkPs exhibited reduced mitochondrial reactive oxygen species, which was related to AKT activity. Txnip−/− MkPs also showed elevated glycolysis alongside increased glucose uptake for ATP production. Total RNA sequencing revealed enrichment for oxidative stress- and apoptosis-related genes in differentially expressed genes between Txnip−/− and WT MkPs. The effects of TXNIP on MKs were recapitulated during the differentiation of human cord blood-derived CD34+ hematopoietic stem cells. ConclusionWe provide evidence that the megakaryopoiesis pathway becomes exhausted with age in Txnip−/− mice with a decrease in terminal, mature MKs that response to thrombocytopenic challenge. Overall, this study demonstrates the role of TXNIP in megakaryopoiesis, regulating mitochondrial metabolism.

Efferocyte-Derived MCTRs Metabolically Prime Macrophages for Continual Efferocytosis via Rac1-Mediated Activation of Glycolysis.

Clearance of multiple rounds of apoptotic cells (ACs) through continual efferocytosis is critical in the maintenance of organ function, the resolution of acute inflammation, and tissue repair. To date, little is known about the nature of mechanisms and factors that govern this fundamental process. Herein, the authors reported that breakdown of ACs leads to upregulation of 12-lipoxygenase in macrophages. This enzyme converts docosahexaenoic acid to maresin conjugates in tissue regeneration (MCTRs). The levels of these autacoids are elevated at sites of high apoptotic burden in vivo and in efferocytosing macrophages in vitro. Abrogation of MCTR production using genetic approaches limits the ability of macrophages to perform continual efferocytosis both in vivo and in vitro, an effect that is rescued by add-back of MCTRs. Mechanistically, MCTR-mediated priming of macrophages for continual efferocytosis is dependent on alterations in Rac1 signalling and glycolytic metabolism. Inhibition of Rac1 abolishes the ability of MCTRs to increase glucose uptake and efferocytosis in vitro, whereas inhibition of glycolysis limits the MCTR-mediated increases in efferocytosis and tissue repair. Together, these findings demonstrate that upregulation of MCTRs by efferocytosing macrophages plays a central role in the regulation of continual efferocytosis via the autocrine and paracrine modulation of metabolic pathways.

Discovery and biological evaluation of novel dual PTP1B and ACP1 inhibitors for the treatment of insulin resistance

In this study, a virtual screening pipeline comprising ligand-based and structure-based approaches was established and applied for the identification of dual PTP1B and ACP1 inhibitors. As a result, a series of benzoic acid derivatives was discovered, and compound H3 and S6 demonstrated PTP1B and ACP1 inhibitory activity, with IC50 values of 3.5 and 8.2 μM for PTP1B, and 2.5 and 5.2 μM for ACP1, respectively. Molecular dynamics simulations illustrated that H3 interacted with critical residues in the active site, such as Cys215 and Arg221 for PTP1B, and Cys17 and Arg18 for ACP1. Enzymatic kinetic research indicated that identified inhibitors competitively inhibited PTP1B and ACP1. Additionally, cellular assays demonstrated that H3 and S6 effectively increased glucose uptake in insulin-resistant HepG2 cells while displaying very limited cytotoxicity at their effective concentrations. In summary, H3 and S6 represent novel dual-target inhibitors for PTP1B and ACP1, warranting further investigation as potential agents for the treatment of diabetes.

The effect of endurance training combined with adenosine on the gene expression of UCP-1 and MAPK p38 in subcutaneous adipose tissue of male Wistar rats fed a high -fat diet

Background: Strategies to increase energy expenditure are an attractive approach to reduce excess fat storage and body weight to improve metabolic health. The aim of the present study was to investigate the effects of endurance training combined with adenosine injection on the gene expression of UCP-1 and MAPK p38 in the subcutaneous adipose tissue of male rats fed a high-fat diet. Materials and Methods: Forty rats were randomly divided into 4 groups: 1. normal control, 2. high-fat diet (HFD) control, 3. HFD + adenosine, and 4. HFD + endurance training + adenosine. After 13 weeks of HFD, 12 weeks of endurance training on a moderate-intensity treadmill was performed. UCP-1 and MAPK p38 mRNA levels were measured by RT-PCR. Results: A significant increase in UCP-1 was observed with in HFD + endurance training + adenosine and HFD + adenosine compared to normal and HFD controls. A significant decrease in MAPK p38 was also observed with HFD + endurance training + adenosine and HFD + adenosine compared to HFD. Conclusion: Endurance training and adenosine are likely activators of UCP-1 gene expression and can be used as effective lipolytic agents in obesity. The MAPK p38 pathway increases glucose uptake by insulin and also induces oxidative phosphorylation in mitochondria following a healthy diet and aerobic activity.