Enzymes Of Glucose Metabolism Research Articles

Reductive stress induced by NRF2/G6PD through glucose metabolic reprogramming promotes malignant transformation in Arsenite-exposed human keratinocytes

Our previous research found that the nuclear factor-E2-related factor 2 (NRF2) protein was sustained activated in malignant transformation of human keratinocyte (HaCaT cells) caused by NaAsO2, but the role of NRF2 in it remains unknown. In this study, malignant transformation of HaCaT cells and labeled HaCaT cells used to detect mitochondrial glutathione levels (Mito-Grx1-roGFP2 HaCaT cells) were induced by 1.0 μM NaAsO2. Redox levels were measured at passages 0, early stage (passages 1, 7, 14), later stage (passages 21, 28 and 35) of arsenite-treated HaCaT cells. Oxidative stress levels increased at early stage. The NRF2 pathway was sustained activated. Cells and mitochondrial reductive stress levels (GSH/GSSG and NADPH/NADP+) increased. The mitochondrial GSH/GSSG levels of Mito-Grx1-roGFP2 HaCaT cells also increased. The indicators of glucose metabolism glucose-6-phosphate, lactate and the glucose-6-phosphate dehydrogenase (G6PD) levels increased, however Acetyl-CoA level decreased. Expression levels of glucose metabolic enzymes increased. After transfection with NRF2 siRNA, the indicators of glucose metabolism were reversed. After transfection with NRF2 or G6PD siRNA, cells and mitochondrial reductive stress levels decreased and the malignant phenotype was reversed. In conclusion, oxidative stress occurred in the early stage and the NRF2 was sustained high expression. In the later stage, increased NRF2/G6PD through glucose metabolic reprogramming induced reductive stress, thereby leading to malignant transformation.

503-P: Distinct Effects of a Novel GCK-MODY Mutation on Lipid Profiles and Diabetic Complications

Glucokinase (GK) encoded by glucokinase gene (GCK) is the first rate-limiting enzyme in glucose metabolism. The heterozygous inactivating mutations of GCK cause maturity-onset diabetes of the young (GCK-MODY). Unlike other types of diabetes, GCK-MODY is not associated with increased risks of diabetic complications in young patients. However, the long-term effects of mutant GK on lipid profiles and chronic complications in elder patients remain unknown. Herein, we established a knock-in mouse model heterozygeously expressing a novel GCK mutation encoding GK-Q26L that was identified in a Chinese family with early onset diabetes. GK-Q26L mice developed mild early onset diabetes with moderate elevated blood glucose and decreased serum insulin, confirming diabetogenes of GK-Q26L. To determine age- and diet-related diabetic complications and lipid profiles, we have fed the mice with either chow diet or high-fat diet (HFD) for 28, 40, or 60 weeks. We found that, after 28 week of HFD, GK-Q26L alleviated abnormal lipid profiles in plasma and liver, suggesting beneficial effects of GK-Q26L on lipid metabolism. Surprisingly however, those protective effects were disappeared at 40 weeks, and at 60 weeks of HFD, GK-Q26L mice exhibited even more severe abnormal lipid profiles. Consistent with the distinct trends of lipid profiles, HFD-induced kidney injury (increased urinary albumin/creatinine ratio and renal fibrosis) was also alleviated in GK-Q26L mice at 28 weeks of HFD, but aggravated at 60 weeks of HFD. Similar effects on diabetic retinopathy were observed in GK-Q26L mice. These data reveal for the first time that although inactivating GCK mutations have beneficial effects on HFD-induced abnormal lipid metabolism and diabetes related damages of kidney and retina in short-term, it is strongly associated with long-term diabetic nephropathy and retinopathy. This study suggests that more attention should be paid on the long-term chronic complications in elder patients with GCK-MODY. Disclosure Y.Huang: None. Y.Fan: None. X.Li: None. S.Ji: None. S.Chen: None. J.Cui: None. W.Feng: None. H.Shu: None. M.Liu: None. Funding National Natural Science Foundation of China (81830025, 82220108014, 82100865, 81800733, 81900720, 82000796, 82070854); National Key R&D Program of China (2019YFA0802502, 2022YFE0131400); Tianjin Key Medical Discipline Construction Project (TJYXZDXK-030A)

Vanillin attenuates CdCl2-induced cytotoxicity in isolated human erythrocytes

Cadmium is a toxic heavy metal with no physiological role in the human body. Cadmium has high mobility due to its widespread industrial use, with no safe and effective therapeutic management. Cadmium toxicity manifests by increasing oxidative stress in target cells. We have explored the potential role of vanillin, a plant phenolic aldehyde and antioxidant, in mitigating cadmium chloride (CdCl2) induced hemotoxicity using isolated human erythrocytes. CdCl2 was added to erythrocytes, in the absence and presence of vanillin. Incubation of erythrocytes with CdCl2 alone inhibited methemoglobin reductase and enhanced methemoglobin level. Heme degradation and release of free iron (Fe2+), along with protein and membrane lipid oxidation, were also increased. A CdCl2-induced enhancement in reactive oxygen and nitrogen species was also seen, lowering the overall antioxidant power of cells. However, pre-incubation of erythrocytes with vanillin resulted in significant decreased generation of reactive species and prevented heme degradation and heme oxidation. Vanillin augmented the erythrocyte antioxidant capacity and reinstated the activities of major antioxidant, plasma membrane-bound and glucose metabolism enzymes. Scanning electron microscopy showed that CdCl2 treatment led to the formation of echinocytes which was prevented by vanillin. In all cases, no harmful effects of vanillin alone were seen. Thus, vanillin alleviates the toxicity of cadmium and can be potentially employed as a chemoprotectant against the damaging effects of this heavy metal.

Huangqi-Danshen decoction reshapes renal glucose metabolism profiles that delays chronic kidney disease progression

Huangqi-Danshen decoction (HDD), a Chinese herbal preparation, is effective in clinical treatment of chronic kidney disease (CKD). However, the underlying mechanism remains to be clarified. In this study, we aimed to investigate the role of HDD in the regulation of renal glucose metabolism in a CKD mouse model. The 0.2% adenine-induced CKD mouse model was administered HDD extract at a dose of 6.8 g/kg/day for 4 weeks. Detection of renal glucose metabolites was performed by ultra-performance liquid chromatography-tandem mass spectrometry. The expression of renal fibrosis and glucose metabolism-related proteins was tested by Western blotting, immunohistochemistry, and immunofluorescence. The results showed that HDD treatment could significantly reduce serum creatinine (0.36 ± 0.10 mg/dL vs. 0.51 ± 0.07 mg/dL, P < 0.05) and blood urea nitrogen (40.02 ± 3.73 mg/dL vs. 62.91 ± 10 mg/dL, P < 0.001) levels, and improve renal pathological injury and fibrosis. Aberrant glucose metabolism was found in the kidneys of CKD mice, manifested by enhanced glycolysis and pentose phosphate pathway, and tricarboxylic acid cycle inhibition, which could be partially restored by HDD treatment. Furthermore, HDD regulated the expression of hexokinase 2, phosphofructokinase, pyruvate kinase M2, pyruvate dehydrogenase E1, oxoglutarate dehydrogenase, and glucose-6-phosphate dehydrogenase in CKD mice. In conclusion, HDD protected against adenine-induced CKD, reshaped glucose metabolism profiles, and restored the expression of key enzymes of glucose metabolism in the kidneys of CKD mice. This study sheds light on targeting glucose metabolism for the treatment of CKD and screening small molecule compounds from herbal medicine to slow CKD progression.

Effect of anthocyanin-rich blackberry juice on endoplasmic reticulum stress in streptozotocin-induced diabetic rats

This study investigates blackberry juice’s effects on glucose metabolism, oxidative stress, inflammation, and endoplasmic reticulum stress (ER) in streptozotocin (STZ)-induced diabetic rats. Fifty Wistar rats were distributed to five groups randomly of ten rats each: Normal control, diabetic control, 9 mL/kg body weight (b.wt) blackberry juice only, blackberry juice plus diabetes, and 500 mg/kg b.wt metformin plus diabetes. A single intraperitoneal injection of 50 mg/kg b.wt STZ induced diabetes in the rats. This animal study continued for 56 days after the confirmation of diabetes. The levels of liver function and renal function, as well as insulin, glucose-6-phosphatase, glucokinase, and malondialdehyde (MDA) levels, and the activities of catalase (CAT) and superoxide dismutase (SOD), were determined. Additionally, interleukin-6 (IL-6) levels, tumor necrosis factor-alpha (TNF-α), and activated transcription factor 4 (ATF4) expressions were examined in the liver homogenate of rats. Furthermore, the liver tissues were utilized for histopathological examination. The results showed that blackberry juice prevented drastic loss of body weight and reduced food consumption in diabetic rats. Additionally, the levels of blood glucose, total protein, aspartate aminotransferase (AST), albumin, alanine aminotransferase (ALT), uric acid, creatinine, and urea improved after the administration of blackberry juice in diabetic rats. Blackberry juice significantly increased glucose metabolism and antioxidant status while reducing ER stress and inflammation in diabetic rats. Moreover, blackberry juice improved glucose metabolism by increasing insulin levels and improving the dysregulated activities of glucose-metabolizing enzymes. The microstructure of liver tissues in diabetic rats was also improved with blackberry juice treatment. Therefore, blackberry juice has the potential to alleviate diabetes in rats and could be considered as a functional food for people with diabetes.

Lactate-induced lactylation circularly regulates glucose metabolism enzymes in breast cancer.

e13092 Background: Breast cancer is the most common malignant tumor in the female population worldwide and has become the disease with the highest cancer-related mortality. Among the molecular subtypes of breast cancer, triple-negative breast cancer accounts for only 15% of primary malignancies, but due to its increasing recurrence, metastasis, and mortality, we need to find new therapeutic targets to address this phenomenon. Analysis from the field of metabolism found that the level of glycolysis in triple-negative breast cancer was significantly higher than that in other cancers. Glycolysis is a common malignant phenotype of cancer, namely the famous Warburg effect. LDHA is the last metabolic enzyme in the glycolytic pathway, and its expression is increased in triple-negative breast cancer. Lactate is the final product of glycolysis, which converts pyruvate to lactate and NADH to NAD+ under the catalysis of LDHA. The acidic tumor microenvironment formed by the accumulation of lactate will not only affect the progression of tumors and the therapeutic effect of anticancer drugs, but also inhibit the function of immune cells. Lactic acid groups can bind to histones and non-histone proteins to produce a new post-translational modification, lactylation. Methods: Breast cancer cells were infected with lentivirus vectors overexpressing or knocking down LDHA, and cell proliferation and cytotoxicity assay, transwell assay and Lactic Acid Content Assay were performed. To further explore the presence of lactylation of LDHA, immunoprecipitation experiments were performed and the modification sites were mutated to examine the enzymatic activity and function of LDHA. Results: In triple negative breast cancer with strong glycolytic metabolic phenotype, altering LDHA level can affect the biological function of breast cancer cells. Secondly, RNA-seq sequencing results showed that LDHA can affect the protein and transcription levels of MEST and CSTA. Finally, the lactylation of histones was also significantly changed after LDHA dysregulated. Reduced levels of LDHA were accompanied by reduced levels of MEST, CSTA, and histone lactylation. In addition, LDHA itself also has lactic acid modification, and mutations in the modification sites can change the enzymatic activity and function of LDHA. Conclusions: The regulatory axis of LDHA-lactate-lactylation has important value and function in the occurrence and development of breast cancer. LDHA regulates the function of some genes by lactate-induced lactylation of histones. In addition, the lactylation of LDHA can alter the enzyme activity, which may be a new therapeutic target for breast cancer.

Effects of Long-Term Cold Stress on Growth Performance, Behavior, Physiological Parameters, and Energy Metabolism in Growing Beef Cattle.

This study aimed to evaluate the effects of a long-term cold environment on growth performance, physiological behavior, biochemical blood indexes, and hormone levels in Simmental cattle. Thirty Simmental crossbred bulls (weight = 350 ± 17 kg, 13-14 months old) were selected for two trials at autumn suitable temperatures (A-ST) and winter cold temperatures (W-CT) (15 cattle per season). The results showed that compared with the A-ST group, dry matter intake (p < 0.05) and feed:gain (p < 0.01) of the W-CT group increased, while body weight (p < 0.01) and average daily gain (p < 0.01) significantly decreased. Long-term cold stress also increased lying time (p < 0.01), feeding time (p < 0.05), and pulse rate (p < 0.01) in the W-CT group, while the rumen volatile fatty acids content (p < 0.01) and apparent digestibility of nutrients (p < 0.05) were significantly decreased. In terms of blood indicators, long-term cold stress increased the concentrations of glucose, glucose metabolic enzymes, glucocorticoids, triiodothyronine, and tetraiodothyronine in the plasma of the W-CT group (p < 0.05), but the levels of triglycerides, β-hydroxybutyrate, propionate, insulin, and growth hormone were decreased (p < 0.01). In summary, long-term cold stress may inhibit the digestive function of Simmental cattle and enhance the body's energy metabolism and stress hormone imbalance, ultimately damaging the normal growth and development of the body.

START domain-mediated nuclear translocation of Them1 regulates the expression of metabolic genes relative to thermogenesis in brown adipocytes

Thioesterase superfamily member 1 (Them1) is a long-chain fatty acyl-CoA thioesterase that is highly expressed in brown adipose tissue (BAT), where it limits energy expenditure. Them1 is comprised of tandem enzymatic domains and a C-terminal lipid-binding steroidogenic acute regulatory protein (StAR)-related lipid transfer (START) domain. Fatty acid binding to the START domain stabilizes the enzymatic domains and increases activity, whereas lysophosphatidylcholine (LPC) acts in the opposite manner. In brown adipocytes, Them1 localizes to puncta within the cytoplasm, but diffuses in response to β-adrenergic stimulation after which it is also found in the nucleus. The aim of this study was to determine the mechanism of Them1 nuclear trafficking and the metabolic consequences. METHODS: Identification of a putative nuclear localization signal (NLS) was determined by computational analysis. Full-length, NLS-deleted, or truncated Them1 cDNA constructs were cloned and linked to EGFP. Plasmid or adenoviral vectors were transfected into immortalized brown adipose cells (iBAs) that do not express Them1. Them1 was visualized by live cell confocal imaging via EGFP and with NucSpot nuclear staining. Signal quantification was performed with Imaris software. Them1 nuclear localization was evaluated in the presence or absence of norepinephrine (NE), leptomycin B, cycloheximide, or lipids that bind the START domain. Them1 nuclear localization was also quantified in BAT from mice treated with a β3-adrenergic receptor agonist, CL316,243. mRNA expression in iBAs expressing full-length or NLS-mutant Them1 in response to NE was determined by RNA-Seq. RESULTS: In the diffuse state, Them1 localized to the nucleus in a time-dependent manner. The NLS resides in a hinge region between the thioesterase domains and the START domain. Deletion of either the NLS or the START domain blocked nuclear targeting. Conversely, truncated Them1 containing only the START domain was targeted to the nucleus. Entry into the nucleus was balanced by trafficking out of the nucleus and new protein synthesis was not required, as evidenced by using leptomycin B to block nuclear efflux and cycloheximide to block protein synthesis, respectively. Incubation of NE-stimulated iBAs with LPC promoted nuclear Them1 translocation. Them1 protein was also detected in the nucleus of BAT from wild-type mice in response to CL administration. Nuclear Them1 localization in iBAs was associated with down-regulated mRNA expression of genes that control lipid and glucose metabolism during cold adaptation. CONCLUSIONS: Our data suggest that LPC generated during thermogenesis binds and destabilizes the START domain, leading to exposure of the NLS and nuclear trafficking of Them1 in response to β-adrenergic stimulation. Once inside the nucleus, Them1 regulates the transcription of lipid and glucose metabolic enzymes that are required for chronic cold adaptation. This work was supported by NIH DK103046 to DEC, SJH, and EAO This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Shotgun metagenomics reveals abnormal short-chain fatty acid-producing bacteria and glucose and lipid metabolism of the gut microbiota in patients with schizophrenia.

Evidence has shown that the gut microbiota is closely related to the pathogenesis of schizophrenia, but temporal changes in the gut microbiota of patients with schizophrenia (SZ) during treatment remain unclear. Here, to evaluate temporal changes in the gut microbiota in schizophrenia, we performed whole-genome shotgun metagenomics on fecal samples from 36 healthy controls (HCs) and 19 baseline-period patients, and followed up with patients upon treatment. Compared to that in HCs, beta diversity in SZ was significantly distinct. The genera Bacteroides, Prevotella and Clostridium were the top 3 altered genera between SZ and HCs, and the Bacteroides-Prevotella ratio was significantly increased in SZ. Thirty-three percent of differentially abundant species were short-chain fatty acid (SCFA)-producing bacteria. Functional analysis showed that glucose and lipid metabolism of the gut microbiota was decreased in SZ compared with those in HCs. The abundances of two rate-limiting enzymes in glucose and lipid metabolism, phosphofructokinase (PFK) and acetyl-CoA carboxylase (ACC), were significantly decreased in SZ, and differentially abundant metabolism-related enzymes were significantly associated with SCFA-producing bacteria. Next, we found that the abundance of SCFA-producing bacteria also changed after treatment and that Clostridium was significantly negatively correlated with the total positive and negative syndrome scale (PANSS) score in patients. Functional analysis showed that glycoside hydrolase family 30 incrementally increased in abundance during treatment and were significantly associated with SCFA-producing bacteria. Our findings help to provide evidence for the role of gut microbiota in the occurrence and development of schizophrenia.

Concurrent induction of apoptosis and necroptosis inapigenin‑treated malignant mesothelioma cells: Reversal ofWarburg effect through Akt inhibition and p53 upregulation.

A high dependence on aerobic glycolysis, known as the Warburg effect, is one of the metabolic features exhibited by tumor cells. Therefore, targeting glycolysis is becoming a very promising strategy for the development of anticancer drugs. In the present study, it was investigated whether pre‑adaptation of malignant mesothelioma (MM) cells to an acidic environment was associated with a metabolic shift to the Warburg phenotype in energy production, and whether apigenin targets acidosis‑driven metabolic reprogramming. Cell viability, glycolytic activity, Annexin V‑PE binding activity, reactive oxygen species (ROS) levels, mitochondrial membrane potential, ATP content, western blot analysis and spheroid viability were assessed in the present study. MM cells pre‑adapted to lactic acid were resistant to the anticancer drug gemcitabine, increased Akt activation, downregulated p53 expression, and upregulated rate‑limiting enzymes in glucose metabolism compared with their parental cells. Apigenin treatment increased cytotoxicity, Akt inactivation and p53 upregulation. Apigenin also reduced glucose uptake along with downregulation of key regulatory enzymes in glycolysis, increased ROS levels with loss of mitochondrial membrane potential, and downregulated the levels of complexes I, III and IV in the mitochondrial electron transport chain with intracellular ATP depletion, resulting in upregulation of molecules mediating apoptosis and necroptosis. Apigenin‑induced alterations of cellular responses were similar to those of Akt inactivation by Ly294002. Overall, the present results provide mechanistic evidence supporting the anti‑glycolytic and cytotoxic role of apigenin via inhibition of the PI3K/Akt signaling pathway and p53 upregulation.

FTY-720 alleviates diabetes-induced liver injury by inhibiting oxidative stress and inflammation.

We aimed to investigate the protective effect of FTY-720 on liver injury and explore its potential mechanism in diabetic mice. The diabetic mouse model was induced with streptozotocin and FTY-720 was administered for 12 weeks. We assayed biocharacters and liver function, and used histopathology staining to evaluate the protective effects of FTY-720 against diabetic liver injury. Levels of oxidative stress and inflammation in the liver were observed. mRNA and protein levels of essential enzymes for glucose metabolism were quantified in the liver and the protein expression of TLR4, HIF1α, and NF-κB was determined. In vivo results revealed that FTY-720 significantly lowered blood glucose and lipids, and improved liver function and alleviated liver fibrosis in diabetic mice. FTY-720 reduced oxidative stress and inflammation, with the increased catalase activity and reduced levels of malondialdehyde, myeloperoxidase, IL-1β, IL-6, TNF-α, TGF-β and MCP1. Furthermore, FTY-720 modulated glucose metabolism in liver and elevated the ATP production, showing the promotion of glycogenesis and glycolysis and inhibition of gluconeogenesis. Moreover, FTY-720 inhibited the expression of TLR4 and HIF1α, contributing to restoration of liver function. In conclusion, FTY-720 ameliorates diabetes-induced liver injury and improves glucose homeostasis by inhibiting oxidative stress and inflammation, and may be a promise drug for treatment of liver disease.

Unearthing of the Antidiabetic Potential of Aqueous Extract of Solanum betaceum Cav. Leaves.

Solanum betaceum Cav., commonly known as tamarillo or Brazilian tomato, belongs to the Solanaceae family. Its fruit is used in traditional medicine and food crops due to its health benefits. Despite the numerous studies involving the fruit, there is no scientific knowledge about the tamarillo tree leaves. In this work, the phenolic profile of aqueous extract obtained from S. betaceum leaves was unveiled for the first time. Five hydroxycinnamic phenolic acids were identified and quantified, including 3-O-caffeoylquinic acid, 4-O-caffeoylquinic acid, chlorogenic acid, caffeic acid and rosmarinic acid. While the extract displayed no effect on α-amylase, the extract inhibited the activity of α-glucosidase (IC50 = 1617 mg/mL), and it was particularly effective for human aldose reductase (IC50 = 0.236 mg/mL): a key enzyme in glucose metabolism. Moreover, the extract exhibited interesting antioxidant properties, such as a potent capacity to intercept the in vitro-generated reactive species O2•- (IC50 = 0.119 mg/mL) and •NO (IC50 = 0.299 mg/mL), as well as to inhibit the first stages of lipid peroxidation (IC50 = 0.080 mg/mL). This study highlights the biological potential of S. betaceum leaves. The scarcity of research on this natural resource underscores the need for additional studies in order to fully explore its antidiabetic properties and to promote the value of a species currently at risk of extinction.

Perturbated glucose metabolism augments epithelial cell proinflammatory function in chronic rhinosinusitis

Glucose concentrations are increased in nasal secretions in chronic rhinosinusitis (CRS). However, the glucose metabolism and its contribution to disease pathogenesis in CRS remain unexplored. We sought to explore the glucose metabolism and its effect on the function of nasal epithelial cells in CRS with and without nasal polyps (CRSwNP and CRSsNP). Glucose metabolites were detected with mass spectrometry. The mRNA levels of glucose transporters (GLUTs), metabolic enzymes, and inflammatory mediators were detected by quantitative RT-PCR. The protein expression of GLUTs was studied by immunofluorescence staining, Western blotting, and flow cytometry. Glucose uptake was measured by using fluorescent glucose analog. Human nasal epithelial cells (HNECs) were cultured. Bioenergetic analysis was performed with Seahorse XF analyzer. Gene expression in HNECs was profiled by RNA sequencing. Increased glucose concentrations in nasal secretions was confirmed in both CRSsNP and CRSwNP. GLUT4, GLUT10, and GLUT11 were abundantly expressed in HNECs, whose expression was upregulated by inflammatory cytokines and D-glucose and was increased in CRS. Glucose uptake, glycolysis and tricarboxylic acid cycle metabolites, metabolic enzymes, and extracellular acidification rate and oxygen consumption rates were increased in HNECs in CRSsNP and CRSwNP, with a predominant shift to glycolysis. HNECs treated with high-level apical D-glucose showed enhanced glucose uptake, predominant glycolysis, and upregulated production of IL-1α, IL-1β, TNF-α, CCL20, and CXCL8, which was suppressed by 2-deoxy-D-glucose, an inhibitor of glycolysis. Increased glucose in nasal secretions promotes glucose uptake and predominant glycolysis in epithelial cells, augmenting the proinflammatory function of epithelial cells in CRS.

Therapeutic Potential of Clove Essential Oil in Diabetes: Modulation of Pro-Inflammatory Mediators, Oxidative Stress and Metabolic Enzyme Activities.

Type 1 diabetes is characterized by insulin deficiency due to the destruction of pancreatic β cells, leading to hyperglycemia, which in turn induces vascular complications. In the current study, we investigated the effect of intraperitoneal administration of clove essential oil (CEO: 20 mg/kg body weight) on certain oxidative stress and glucose metabolism enzymes, as well as the expression of proinflammatory mediators. Administration of CEO to diabetic rats showed a significant decline in blood glucose levels, total cholesterol, and xanthine oxidase, compared to the streptozotocin group. Furthermore, these treated rats elicited a notable attenuation in the levels of lipid peroxides, and thiols groups in both liver and brain tissues. The activities of antioxidant and metabolic enzymes were reverted to normality in diabetic upon CEO administration. In addition to its protective effects on red blood cell hemolysis, CEO is a potent α-amylase inhibitor with an IC50 =298.0±2.75 μg/mL. Also, treatment of diabetic rats with CEO significantly reduced the iNOS expression in the spleen. Our data showed that CEO has potential beneficial effects on diabetes, which can possibly prevent the pathogenesis of diabetic micro- and macrovascular complications.

Discovery of Novel Thiazolidinedione-Derivatives with Multi-Modal Antidiabetic Activities In Vitro and In Silico.

Diabetes mellitus (DM) and related complications continue to exert a significant burden on health care systems globally. Although conventional pharmacological therapies are beneficial in the management of this metabolic condition, it is still necessary to seek novel potential molecules for its management. On this basis, we have synthesised and evaluated the anti-diabetic properties of four novel thiazolidinedione (TZD)-derivatives. The TZD derivatives were synthesised through the pharmacophore hybridisation strategy based on N-arylpyrrole and TZD. The resultant derivatives at different concentrations were screened against key enzymes of glucose metabolism and glucose utilisation in the liver (HEP-G2) cell line. Additionally, peroxisome proliferator-activated receptor-γ activation was performed through docking studies. Docking of these molecules against PPAR-γ predicted strong binding, similar to that of rosiglitazone. Hence, TZDD2 was able to increase glucose uptake in the liver cells as compared to the control. The enzymatic inhibition assays showed a relative inhibition activity; with all four derivatives exhibiting ≥ 50% inhibition activity in the α-amylase inhibition assay and a concentration dependent activity in the α-glucosidase inhibition assay. All four derivatives exhibited ≥30% inhibition in the aldose reductase inhibition assay, except TZDD1 at 10 µg/mL. Interestingly, TZDD3 showed a decreasing inhibition activity. In the dipeptidyl peptidase-4 inhibition assay, TZDD2 and TZDD4 exhibited ≥20% inhibition activity.

Expression of Key Enzymes in Glucose Metabolism in Chronic Mountain Sickness and Its Correlation with Phenotype

To explore the pathogenesis of erythrocytosis by detecting the key enzymes of glucose metabolism and glucose transporter in bone marrow erythrocytes of chronic mountain sickness (CMS), and analyzing its correlation with hemoglobin. Twenty CMS patients hospitalized in Qinghai Provincial People's Hospital from January 2019 to December 2020 were selected as CMS group. Twenty males with leukocyte count > 3.5×109/L who had accepted bone marrow aspiration and had normal result were taken as control group. The mRNA and protein expression of key enzymes and glucose transporter in glucose metabolism in bone marrow CD71+ erythrocytes were detected by real time qPCR and Western blot, respectively. Glucose, lactic acid and 2,3-diphosphoglycerate in the bone marrow supernatant and serum were tested by ELISA. The mRNA and protein expression of key enzymes and glucose transporter, glucose, lactic acid and 2,3-diphosphoglycerate of the two groups were compared. Pearson correlation was used to analyze the correlation between key enzymes, glucose transporter in glucose metabolism in bone marrow CD71+ erythrocytes and hemoglobin. The expression of HK2, GLUT1 and GLUT2 mRNA in the CMS group were higher than those in the control group (P<0.001), while the expression of HK1, OGDH and COX5B mRNA were not different. The expression of HK2, GLUT1 and GLUT2 protein in the CMS group were higher than those in the control group (P<0.05). The levels of glucose and lactic acid in the bone marrow supernatant and serum in the CMS group were not different from those in the control group, while the level of 2,3-diphosphoglycerate was higher (P<0.001). Both HK2 and GLUT2 proteins were positively correlated with hemoglobin (r=0.511, 0.717). CMS patients may increase glycolysis by increasing the expression of HK2, and promote the utilization of glucose through high expression of GLUT1 and GLUT2 to meet the need of energy supply.

Effects of Carbohydrase Supplementation on Growth Performance, Intestinal Digestive Enzymes and Flora, Glucose Metabolism Enzymes, and glut2 Gene Expression of Hybrid Grouper (Epinephelus fuscoguttatus♀ × E. lanceolatus♂) Fed Different CHO/L Ratio Diets.

An optimal carbohydrate-to-lipid (CHO: L) ratio facilitates fish growth and protein conservation, and carbohydrase promotes nutrient absorption. Therefore, an 8-week feeding trial was conducted to investigate the effects of carbohydrase supplementation on growth performance, intestinal digestive enzymes and flora, glucose metabolism enzymes and glut2 gene expression in juvenile hybrid grouper (Epinephelus fuscoguttatus♀× Epinephelus lanceolatus♂) fed different CHO: L ratios diets. L, M, and H represent CHO:L ratios of 0.91, 1.92 and 3.91, respectively. LE, ME, and HE represent CHO:L ratios of 0.91, 1.92, 3.91, respectively, supplemented with the same ratio of carbohydrase. Results showed that weight gain rate (WGR) and specific growth rate (SGR) reached a maximum in group M and were significantly enhanced by carbohydrase (p < 0.05). Crude lipid content decreased significantly with an increase in the dietary CHO:L ratio (p < 0.05). Significant increases in the trypsin (TRY) and amylase (AMS) activities and significant decreases in the lipase (LPS) activity were observed with increasing dietary CHO:L ratio, and the former two were significantly promoted by carbohydrase (p < 0.05). The content of liver and muscle glycogen increased significantly with the increasing dietary CHO:L ratio but decreased significantly after carbohydrase supplementation (p < 0.05). The glucokinase (GK), pyruvate kinase (PK), Phosphate 6 fructokinase-1 (PFK-1) and phosphoenolpyruvate kinase (PEPCK) activities increased significantly with increasing dietary CHO:L ratio (p < 0.05). Glut2 mRNA expression decreased significantly in liver and increased significantly in intestine with increasing dietary CHO:L ratio (p < 0.05). By linear discriminant analysis (LDA), the abundance of Alistipe was significantly higher in Group ME than in Group M. These results suggested that hybrid grouper can only moderately utilize dietary carbohydrate and lipid in diet, and a certain amount of high glycemic lipids occurred when fed with high-carbohydrate diets. By the weight gain for basis, the supplementation of carbohydrase in Group H with amylase, glycosylase, and pullulanase in a 1:1:1 ratio effectively lowered glycemic lipids, promoted the growth of grouper, digestive enzymes activities and carbohydrate metabolic enzyme, and glut2 gene expression in intestine, effectively balancing the negative effects of high-carbohydrate diet and improving the utilization of carbohydrate.

High glucose causes developmental abnormalities in neuroepithelial cysts with actin and HK1 distribution changes.

It has been reported that the offspring of diabetic pregnant women have an increased risk for neural tube defects. Previous studies in animal models suggested that high glucose induces cell apoptosis and epigenetic changes in the developing neural tube. However, effects on other cellular aspects such as the cell shape changes were not fully investigated. Actin dynamics plays essential roles in cell shape change. Disruption on actin dynamics is known to cause neural tube defects. In the present study, we used a 3D neuroepithelial cyst model and a rosette model, both cultured from human embryonic stem cells, to study the cellular effects caused by high glucose. By using these models, we observed couple of new changes besides increased apoptosis. First, we observed that high glucose disturbed the distribution of pH3 positive cells in the neuroepithelial cysts. Secondly, we found that high glucose exposure caused a relatively smaller actin inner boundary enclosed area, which was unlikely due to osmolarity changes. We further investigated key glucose metabolic enzymes in our models and the results showed that the distribution of hexokinase1 (HK1) was affected by high glucose. We observed that hexokinase1 has an apical-basal polarized distribution and is highest next to actin at the boundaries. hexokinase1 was more diffused and distributed less polarized under high glucose condition. Together, our observations broadened the cellular effects that may be caused by high glucose in the developing neural tube, especially in the secondary neurulation process.

Microglial metabolic reconfiguration provides a new strategy for the treatment of Alzheimer's disease.

Microglial metabolic reconfiguration provides a new strategy for the treatment of Alzheimer's disease.

Synthesis and Potential Antidiabetic Properties of Curcumin-Based Derivatives: An In Vitro and In Silico Study of α-Glucosidase and α-Amylase Inhibition.

Over the past twenty years, the prevalence of diabetes as one of the most common metabolic diseases has become a public health problem worldwide. Blood glucose control is important in delaying the onset and progression of diabetes-related complications. α-Glycosidase (α- Glu) and α-amylase (α-Amy) are important enzymes in glucose metabolism. Diabetic control through the inhibition of carbohydrate hydrolyzing enzymes is established as an effective strategy. In this study, curcumin-based benzaldehyde derivatives with high stability, bioavailability, and favorable efficiency were synthesized. The results showed that L13, L8, and L11 derivatives have the highest inhibitory effect on α-Glu with IC50 values of 18.65, 20.6, and 31.7 μM and, also L11, L13, and L8 derivatives have the highest inhibitory effect on α-Amy with IC50 value of 14.8, 21.8, and 44.9 μM respectively. Furthermore, enzyme inhibitory kinetic characterization was also performed to understand the mechanism of enzyme inhibition. L13, compared to the other compounds, exhibited acceptable inhibitory activity against both enzymes. The L13 derivative could be an appropriate candidate for further study through the rational drug design to the exploration of a new class of powerful anti-diabetic drugs considering the antioxidant properties of the synthesized compounds. The derivative helps reduce the glycemic index and limits the activity of the major reactive oxygen species (ROS) producing pathways.