bims-glecem 2022-06-12 papers

bims-glecem

Biomed News

on Glycogen metabolism in exercise, cancer and energy metabolism

Issue of 2022–06–12
sixteen papers selected by
Dipsikha Biswas, Københavns Universitet

Insights into Phosphorylation-Induced Protein Allostery and Conformational Dynamics of Glycogen Phosphorylase via Integrative Structural Mass Spectrometry and In Silico Modeling.
Label-free study of intracellular glycogen level in metformin and resveratrol-treated insulin-resistant HepG2 by live-cell FTIR spectroscopy.
Pathobiology and Therapeutic Relevance of GSK-3 in Chronic Hematological Malignancies.
Molecular docking study of GSK-3β interaction with nomilin, kihadanin B, and related limonoids and triterpenes with a furyl-δ-lactone core.
Lentiviral gene therapy prevents anti-human acid α-glucosidase antibody formation in murine Pompe disease.
Isogenic GAA-KO Murine Muscle Cell Lines Mimicking Severe Pompe Mutations as Preclinical Models for the Screening of Potential Gene Therapy Strategies.
The fatty acid synthase inhibitor C75 differentially affects the adipogenic differentiation of multipotent cells and preadipocytes.
Glycogen synthase kinase-3β inhibition decreases inflammation and relieves cancer induced bone pain via reducing Drp1-mediated mitochondrial damage.
3,3',4,5'-Tetramethoxy-trans-stilbene Improves Insulin Resistance by Activating the IRS/PI3K/Akt Pathway and Inhibiting Oxidative Stress.
Gynostemma pentaphyllum extract and its active component gypenoside L improve the exercise performance of treadmill-trained mice.
Disturbed glucose metabolism by perfluorobutanesulfonate pollutant and benefit of young fecal transplantation in aged zebrafish.
Insulin-Related Liver Pathways and the Therapeutic Effects of Aerobic Training, Green Coffee, and Chlorogenic Acid Supplementation in Prediabetic Mice.
Understanding the Mechanism of Dysglycemia in a Fanconi-Bickel Syndrome Patient.
Glycogen, poly(3-hydroxybutyrate) and pigment accumulation in three Synechocystis strains when exposed to a stepwise increasing salt stress.
High Starch in Diet Leads to Disruption of Hepatic Glycogen Metabolism and Liver Fibrosis in Largemouth Bass (Micropterus salmoides), Which is Mediated by the PI3K/Akt Signaling Pathway.
Sleep Deprivation and Circadian Disruption Stress, Allostasis, and Allostatic Load.

ACS Chem Biol. 2022 Jun 08.

Insights into Phosphorylation-Induced Protein Allostery and Conformational Dynamics of Glycogen Phosphorylase via Integrative Structural Mass Spectrometry and In Silico Modeling.

Jing Huang, Xiakun Chu, Yuxiang Luo, Yong Wang, Ying Zhang, Yu Zhang, Huilin Li.

Allosteric regulation plays a fundamental role in innumerable biological processes. Understanding its dynamic mechanism and impact at the molecular level is of great importance in disease diagnosis and drug discovery. Glycogen phosphorylase (GP) is a phosphoprotein responding to allosteric regulation and has significant biological importance to glycogen metabolism. Although the atomic structures of GP have been previously solved, the conformational dynamics of GP related to allostery regulation remain largely elusive due to its macromolecular size (∼196 kDa). Here, we integrated native top-down mass spectrometry (nTD-MS), hydrogen-deuterium exchange MS (HDX-MS), protection factor (PF) analysis, molecular dynamics (MD) simulations, and allostery signaling analysis to examine the structural basis and dynamics for the allosteric regulation of GP by phosphorylation. nTD-MS reveals differences in structural stability as well as oligomeric state between the unphosphorylated (GPb) and phosphorylated (GPa) forms. HDX-MS, PF analysis, and MD simulations further pinpoint the structural differences between GPb and GPa involving the binding interfaces (the N-terminal and tower-tower helices), catalytic site, and PLP-binding region. More importantly, it also allowed us to complete the missing link of the long-range communication process from the N-terminal tail to the catalytic site caused by phosphorylation. This integrative MS and in silico-based platform is highly complementary to biophysical approaches and yields valuable insights into protein structures and dynamic regulation.

DOI: https://doi.org/10.1021/acschembio.2c00393
Biosens Bioelectron. 2022 May 27. pii: S0956-5663(22)00456-0. [Epub ahead of print]212 114416

Label-free study of intracellular glycogen level in metformin and resveratrol-treated insulin-resistant HepG2 by live-cell FTIR spectroscopy.

Anchisa Poonprasartporn, K L Andrew Chan.

  Conventional in vitro study often involves the destruction of the cells followed by purification and dilution steps before applying enzymatic assay or metabolomic analysis. It is a costly and laborious process, and it cannot monitor changes as a function of time. Recently, we have developed a new label-free live-cell FTIR approach that can directly measure biochemical compositional changes within living cells in situ and the spectral changes are shown to be highly specific to the drug applied. In this work, we have demonstrated for the first time the effect of two anti-diabetic drugs, metformin and Resveratrol, on insulin-resistant liver cells (HepG2). Using live-cell FTIR with principal component analysis, we have shown the differences in the biochemical profiles between normal and insulin-resistant cells (p < 0.05), the lack of response/difference from the insulin-resistant cell to insulin (p > 0.05) and the restoration of the biochemical profile and sensitivity to insulin from the insulin-resistant cells after the drug treatment (p < 0.05). Particularly, a rise in the glycogen level, marked by three distinctive peaks at 1150, 1080 and 1020 cm-1, within the living cells after the anti-diabetic drug treatments is observed. The live-cell FTIR results are confirmed by a parallel gold-standard biochemical assay, demonstrating the restoration of insulin sensitivity of the insulin-resistance cells. Live-cell FTIR can be a complementary tool for drug efficacy screening, especially for insulin sensitizers.

Keywords:  Anti-diabetic drugs; Chemometric analysis; Diabetes; Drug screening; High throughput; Infrared spectroscopy

DOI:  https://doi.org/10.1016/j.bios.2022.114416
Cells. 2022 May 31. pii: 1812. [Epub ahead of print]11(11):

Pathobiology and Therapeutic Relevance of GSK-3 in Chronic Hematological Malignancies.

Alberto M Martelli, Francesca Paganelli, Camilla Evangelisti, Francesca Chiarini, James A McCubrey.

  Glycogen synthase kinase-3 (GSK-3) is an evolutionarily conserved, ubiquitously expressed, multifunctional serine/threonine protein kinase involved in the regulation of a variety of physiological processes. GSK-3 comprises two isoforms (α and β) which were originally discovered in 1980 as enzymes involved in glucose metabolism via inhibitory phosphorylation of glycogen synthase. Differently from other proteins kinases, GSK-3 isoforms are constitutively active in resting cells, and their modulation mainly involves inhibition through upstream regulatory networks. In the early 1990s, GSK-3 isoforms were implicated as key players in cancer cell pathobiology. Active GSK-3 facilitates the destruction of multiple oncogenic proteins which include β-catenin and Master regulator of cell cycle entry and proliferative metabolism (c-Myc). Therefore, GSK-3 was initially considered to be a tumor suppressor. Consistently, GSK-3 is often inactivated in cancer cells through dysregulated upstream signaling pathways. However, over the past 10-15 years, a growing number of studies highlighted that in some cancer settings GSK-3 isoforms inhibit tumor suppressing pathways and therefore act as tumor promoters. In this article, we will discuss the multiple and often enigmatic roles played by GSK-3 isoforms in some chronic hematological malignancies (chronic myelogenous leukemia, chronic lymphocytic leukemia, multiple myeloma, and B-cell non-Hodgkin's lymphomas) which are among the most common blood cancer cell types. We will also summarize possible novel strategies targeting GSK-3 for innovative therapies of these disorders.

Keywords:  B-cell non-Hodgkin’s lymphomas; GSK-3; chronic hematological malignancies; chronic lymphocytic leukemia; chronic myelogenous leukemia; multiple myeloma; paralogs; targeted therapy

DOI:  https://doi.org/10.3390/cells11111812
J Biochem Mol Toxicol. 2022 Jun 10. e23130

Molecular docking study of GSK-3β interaction with nomilin, kihadanin B, and related limonoids and triterpenes with a furyl-δ-lactone core.

Gérard Vergoten, Christian Bailly.

  Glycogen synthase kinase-3β (GSK-3β) is a target enzyme considered for the treatment of multiple human diseases, from neurodegenerative pathologies to viral infections and cancers. Numerous inhibitors of GSK-3β have been discovered but thus far only a few have reached clinical trials and only one drug, tideglusib (1), has been registered. Natural products targeting GSK-3β have been identified, including the two anticancer limonoids obacunone (5) and gedunin (4), both presenting a furyl-δ-lactone core. To help identifying novel GSK-3β ligands, we have performed a molecular docking study with 15 complementary natural products bearing a furyl-δ-lactone unit (such as limonin (6) and kihadanins A (8) and B (9)) or a closely related structure (such as cedrelone (10) and nimbolide (11)). The formation of GSK-3β-binding complexes for those natural products was compared to reference GSK-3β ATP-competitive inhibitors LY2090314 (3) and AR-A014418 (2). Our in silico analysis led to the identification of two new GSK-3β-binding natural products: kihadanin B (9) and nomilin (7). The latter surpassed the reference compounds in terms of calculated empirical energy of interaction (ΔE). Nomilin (7) can possibly bind to the active site of GSK-3β, notably via the furyl-δ-lactone core and its 1-acetyl group, implicated in the protein interaction. Compound structure-binding relationships are discussed. The study should help the discovery of novel natural products targeting GSK-3β.

Keywords:  cancer; drug design; natural products; oncology; pharmacology

DOI:  https://doi.org/10.1002/jbt.23130
Mol Ther Methods Clin Dev. 2022 Jun 09. 25 520-532

Lentiviral gene therapy prevents anti-human acid α-glucosidase antibody formation in murine Pompe disease.

Qiushi Liang, Eva C Vlaar, Fabio Catalano, Joon M Pijnenburg, Merel Stok, Yvette van Helsdingen, Arnold G Vulto, Wendy W J Unger, Ans T van der Ploeg, W W M Pim Pijnappel, Niek P van Til.

  Enzyme replacement therapy (ERT) is the current standard treatment for Pompe disease, a lysosomal storage disorder caused by deficiency of the lysosomal enzyme acid alpha-glucosidase (GAA). ERT has shown to be lifesaving in patients with classic infantile Pompe disease. However, a major drawback is the development of neutralizing antibodies against ERT. Hematopoietic stem and progenitor cell-mediated lentiviral gene therapy (HSPC-LVGT) provides a novel, potential lifelong therapy with a single intervention and may induce immune tolerance. Here, we investigated whether ERT can be safely applied as additional or alternative therapy following HSPC-LVGT in a murine model of Pompe disease. We found that lentiviral expression at subtherapeutic dose was sufficient to induce tolerance to the transgene product, as well as to subsequently administered ERT. Immune tolerance was established within 4-6 weeks after gene therapy. The mice tolerated ERT doses up to 100 mg/kg, allowing ERT to eliminate glycogen accumulation in cardiac and skeletal muscle and normalizing locomotor function. The presence of HSPC-derived cells expressing GAA in the thymus suggested the establishment of central immune tolerance. These findings demonstrate that lentiviral gene therapy in murine Pompe disease induced robust and long-term immune tolerance to GAA either expressed by a transgene or supplied as ERT.

Keywords:  Pompe disease; acid alpha-glucosidase; antibody formation; immune response; immune tolerance induction; lentiviral gene therapy; lysosomal storage disorders

DOI:  https://doi.org/10.1016/j.omtm.2022.04.016
Int J Mol Sci. 2022 Jun 04. pii: 6298. [Epub ahead of print]23(11):

Isogenic GAA-KO Murine Muscle Cell Lines Mimicking Severe Pompe Mutations as Preclinical Models for the Screening of Potential Gene Therapy Strategies.

Araceli Aguilar-González, Juan Elías González-Correa, Eliana Barriocanal-Casado, Iris Ramos-Hernández, Miguel A Lerma-Juárez, Sara Greco, Juan José Rodríguez-Sevilla, Francisco Javier Molina-Estévez, Valle Montalvo-Romeral, Giuseppe Ronzitti, Rosario María Sánchez-Martín, Francisco Martín, Pilar Muñoz.

  Pompe disease (PD) is a rare disorder caused by mutations in the acid alpha-glucosidase (GAA) gene. Most gene therapies (GT) partially rely on the cross-correction of unmodified cells through the uptake of the GAA enzyme secreted by corrected cells. In the present study, we generated isogenic murine GAA-KO cell lines resembling severe mutations from Pompe patients. All of the generated GAA-KO cells lacked GAA activity and presented an increased autophagy and increased glycogen content by means of myotube differentiation as well as the downregulation of mannose 6-phosphate receptors (CI-MPRs), validating them as models for PD. Additionally, different chimeric murine GAA proteins (IFG, IFLG and 2G) were designed with the aim to improve their therapeutic activity. Phenotypic rescue analyses using lentiviral vectors point to IFG chimera as the best candidate in restoring GAA activity, normalising the autophagic marker p62 and surface levels of CI-MPRs. Interestingly, in vivo administration of liver-directed AAVs expressing the chimeras further confirmed the good behaviour of IFG, achieving cross-correction in heart tissue. In summary, we generated different isogenic murine muscle cell lines mimicking the severe PD phenotype, as well as validating their applicability as preclinical models in order to reduce animal experimentation.

Keywords:  CRISPR/Cas9 technology; Pompe disease; adeno-associated virus; cellular disease models; lentiviral vectors; optimised GAA (acid alpha-glucosidase)

DOI:  https://doi.org/10.3390/ijms23116298
FEBS Lett. 2022 Jun 11.

The fatty acid synthase inhibitor C75 differentially affects the adipogenic differentiation of multipotent cells and preadipocytes.

Kuo-Yun Tseng, Ko-Hung Liu, Hung-Ming Wu, Shankung Lin.

  Previously, we revealed the dual enhancing effect of netoglitazone, an agonist of the peroxisome proliferator-activated receptor γ (PPARγ), on adipogenesis and osteoblastogenesis, and reported that fatty acid synthase (FASN) knockdown selectively repressed its pro-adipogenic effect. Here, we examined if a FASN inhibitor, C75, could selectively repress the pro-adipogenic effect of netoglitazone. Surprisingly, C75 promoted the adipogenic differentiation of multipotent C3H10T1/2 cells but inhibited that of 3T3-L1 preadipocytes. By identifying glycogen synthase kinase-3β (GSK3β) and intracellular cAMP levels as regulatory targets of C75, we ultimately found the differential expression of adenosine receptor 3 (AR3) and AR2a on these cells. Inhibition of AR3 on C3H10T1/2 and AR2a on 3T3-L1 inhibited the effects of C75 on the differentiation of these cells. Our findings imply that cell type-specific AR expression might account for the differential adipogenic effects of C75.

Keywords:  GSK3β; adenosine receptor; adipogenesis; aging; cAMP

DOI:  https://doi.org/10.1002/1873-3468.14424
J Cell Mol Med. 2022 Jun 10.

Glycogen synthase kinase-3β inhibition decreases inflammation and relieves cancer induced bone pain via reducing Drp1-mediated mitochondrial damage.

He-Yu Yang, Feng Zhang, Meng-Lin Cheng, Ji Wu, Min Xie, Liang-Zhu Yu, Ling Liu, Jun Xiong, Hai-Li Zhu.

  Bone is the preferential site of metastasis for breast cancer. Invasion of cancer cells induces the destruction of bone tissue and damnification of peripheral nerves and consequently induced central sensitization which contributes to severe pain. Herein, cancer induced bone pain (CIBP) rats exhibited destruction of tibia, mechanical allodynia and spinal inflammation. Inflammatory response mainly mediated by astrocyte and microglia in central nervous system. Our immunofluorescence analysis revealed activation of spinal astrocytes and microglia in CIBP rats. Transmission electron microscopy (TEM) observations of mitochondrial outer membrane disruption and cristae damage in spinal mitochondria of CIBP rats. Proteomics analysis identified abnormal expression of proteins related to mitochondrial organization and function. Intrathecally, injection of GSK-3β activity inhibitor TDZD-8 significantly attenuated Drp1-mediated mitochondrial fission and recovered mitochondrial function. Inhibition of GSK-3β activity also suppressed NLRP3 inflammasome cascade and consequently decreased mechanical pain sensitivity of CIBP rats. For cell research, TDZD-8 treatment significantly reversed TNF-α induced mitochondrial membrane potential (MMP) deficiency and high mitochondrial reactive oxygen species level. Taken together, GSK-3β inhibition by TDZD-8 decreases spinal inflammation and relieves cancer induced bone pain via reducing Drp1-mediated mitochondrial damage.

Keywords:  cancer-induced bone pain; dynamic-related protein 1; glycogen synthase kinase-3β; mitochondria; spinal inflammation

DOI:  https://doi.org/10.1111/jcmm.17432
Curr Issues Mol Biol. 2022 May 12. 44(5): 2175-2185

3,3',4,5'-Tetramethoxy-trans-stilbene Improves Insulin Resistance by Activating the IRS/PI3K/Akt Pathway and Inhibiting Oxidative Stress.

Yi Tan, Lingchao Miao, Jianbo Xiao, Wai San Cheang.

  The potential anti-diabetic effect of resveratrol derivative, 3,3',4,5'-tetramethoxy-trans-stilbene (3,3',4,5'-TMS) and its underlying mechanism in high glucose (HG) and dexamethasone (DXMS)-stimulated insulin-resistant HepG2 cells (IR-HepG2) were investigated. 3,3',4,5'-TMS did not reduce the cell viability of IR-HepG2 cells at the concentrations of 0.5-10 µM. 3,3',4,5'-TMS increased the potential of glucose consumption and glycogen synthesis in a concentration-dependent manner in IR-HepG2 cells. 3,3',4,5'-TMS ameliorated insulin resistance by enhancing the phosphorylation of glycogen synthase kinase 3 beta (GSK3β), inhibiting phosphorylation of insulin receptor substrate-1 (IRS-1), and activating phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway in IR-HepG2 cells. Furthermore, 3,3',4,5'-TMS significantly suppressed levels of reactive oxygen species (ROS) with up-regulation of nuclear factor erythroid 2-related factor 2 (Nrf2) expression. To conclude, the beneficial effect of 3,3',4,5'-TMS against insulin resistance to increase glucose consumption and glycogen synthesis was mediated through activation of IRS/PI3K/Akt signaling pathways in the IR-HepG2 cells, accomplished with anti-oxidative activity through up-regulation of Nrf2.

Keywords:  3,3′,4,5′-tetramethoxy-trans-stilbene; HepG2 cells; glucose consumption; glycogen synthesis; insulin resistance; oxidative stress

DOI:  https://doi.org/10.3390/cimb44050147
Nutr Res Pract. 2022 Jun;16(3): 298-313

Gynostemma pentaphyllum extract and its active component gypenoside L improve the exercise performance of treadmill-trained mice.

Yoon Hee Kim, Jae In Jung, Young Eun Jeon, So Mi Kim, Su Hee Hong, Tae Young Kim, Eun Ji Kim.

   BACKGROUND/OBJECTIVES: The effectiveness of natural compounds in improving athletic ability has attracted attention in both sports and research. Gynostemma pentaphyllum (Thunb.) leaves are used to make traditional herbal medicines in Asia. The active components of G. pentaphyllum, dammarane saponins, or gypenosides, possess a range of biological activities. On the other hand, the anti-fatigue effects from G. pentaphyllum extract (GPE) and its effective compound, gypenoside L (GL), remain to be determined.
MATERIALS/METHODS: This study examined the effects of GPE on fatigue and exercise performance in ICR mice. GPE was administered orally to mice for 6 weeks, with or without treadmill training. The biochemical analysis in serum, glycogen content, mRNA, and protein expressions of the liver and muscle were analyzed.
RESULTS: The ExGPE (exercise with 300 mg/kg body weight/day of GPE) mice decreased the fat mass percentage significantly compared to the ExC mice, while the ExGPE showed the greatest lean mass percentage compared to the ExC group. The administration of GPE improved the exercise endurance and capacity in treadmill-trained mice, increased glucose and triglycerides, and decreased the serum creatine kinase and lactate levels after intensive exercise. The muscle glycogen levels were higher in the ExGPE group than the ExC group. GPE increased the level of mitochondrial biogenesis by enhancing the phosphorylation of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) protein and the mRNA expression of nuclear respiratory factor 1, mitochondrial DNA, peroxisome proliferator-activated receptor-δ, superoxide dismutase 2, and by decreasing the lactate dehydrogenase B level in the soleus muscle (SOL). GPE also improved PGC-1α activation in the SOL significantly through AMPK/p38 phosphorylation.
CONCLUSIONS: These results showed that GPE supplementation enhances exercise performance and has anti-fatigue activity. In addition, the underlying molecular mechanism was elucidated. Therefore, GPE is a promising candidate for developing functional foods and enhancing the exercise capacity and anti-fatigue activity.

Keywords:  Gynostemma pentaphyllum; exercise; fatigue; glycogen; mitochondrial biogenesis

DOI:  https://doi.org/10.4162/nrp.2022.16.3.298
Ecotoxicol Environ Saf. 2022 Jun 02. pii: S0147-6513(22)00561-9. [Epub ahead of print]241 113721

Disturbed glucose metabolism by perfluorobutanesulfonate pollutant and benefit of young fecal transplantation in aged zebrafish.

Mengyuan Liu, Baili Sun, Xiangzhen Zhou, Lianguo Chen.

  Perfluorobutanesulfonate (PFBS) is an environmental pollutant of emerging concern, which significantly impacts the metabolism and health of animals. Because of the loss of functional capacity, the aged animals are regarded more susceptible to the toxicity of environmental pollutants. In the present study, aged zebrafish were employed as the toxicological animal and transplanted with the feces collected from young donors for 14 days, after which the acclimated elderly were exposed to PFBS at environmentally relevant concentrations (0 and 100 μg/L) for another 14 days. When the exposure was concluded, glucose metabolic disturbances of PFBS in the aged and efficacy of young fecal transplant to mitigate the toxicity of PFBS were explored along the gut-liver axis. The results showed that PFBS exposure significantly inhibited the enzymatic activity of α-amylase in the gut, but increased the alanine aminotransferase (ALT) activity in the blood of the aged zebrafish, suggesting the impairment of intestinal digestive functions of carbohydrates and the induction of liver damage by PFBS. However, young fecal transplantation successfully ameliorated the toxicity of PFBS on α-amylase and ALT, underlining the benefits conveyed to the health of the elderly. In addition, transplantation of young feces was efficient to alleviate the hyperglycemia symptom in the elderly via stimulating the secretion of insulin. PFBS exposure increased blood glucagon level, disrupted insulin receptor transcription, and depleted hepatic glycogen store, which were all mitigated by young fecal transplant. Hepatic proteomic analysis also found dynamic interactions between young fecal transplantation and PFBS pollutant on the metabolic pathways of glucose and glycogen, involving glycolysis, gluconeogenesis, glycogenesis, and glycogenolysis. Overall, the present findings highlighted the beneficial effects of young fecal transplantation to protect the aged from the glucose metabolism toxicity of PFBS, thus providing a plausible measure to improve the health aging status.

Keywords:  Aging; Glucose; Glycogen; PFBS; Young fecal transplantation; Zebrafish

DOI:  https://doi.org/10.1016/j.ecoenv.2022.113721
Oxid Med Cell Longev. 2022 ;2022 5318245

Insulin-Related Liver Pathways and the Therapeutic Effects of Aerobic Training, Green Coffee, and Chlorogenic Acid Supplementation in Prediabetic Mice.

Milad Abdollahi, Sayyed Mohammad Marandi, Kamran Ghaedi, Zahra Safaeinejad, Fatemeh Kazeminasab, Samaneh Shirkhani, Mohammad Hossein Sanei, Parsa Rezvanian, Mohammad Hossein Nasr-Esfahani.

Background: The liver controls blood glucose levels via regulation of anabolic (glycogen synthesis and gluconeogenesis) and catabolic (glycolysis and glycogenolysis) processes through activation of the PI3K-AKT signalling pathway. The aim of this study was to assess the effect of aerobic training, green coffee, and chlorogenic acid supplementation on glucose metabolism-regulating pathways in prediabetic mice.
Methods: C57BL/6 mice were exposed to a high-fat diet and physical activity limitation to induce a state of prediabetes. After 12 weeks, mice were fed a high-fat diet compared to the control mice. The prediabetic mice were further treated with either green coffee, chlorogenic acid, or training or combinations of the same for 10 weeks. At the end of the experimental period, metabolic data (FBG, GTT, HOMA for IR, plasma level of insulinfrom systematic, AST, and ALT assessed into blood), histopathologic, and analysis of gene and protein expressions were obtained for target tissues.
Results: Training along with green coffee and chlorogenic acid supplementation improved complications of prediabetes including weight gain and elevated fasting blood glucose and plasma insulin levels. These effects were associated with the changes in mRNA levels of genes important in hepatic glycogen synthesis (GYS2), glucogenesis (PCK and G6PC2), and glycolysis (GK, PK, and PFKL).
Conclusion: The training in conjunction with green coffee or chlorogenic acid is effective in the prevention of prediabetes in mice. As these interventions are relatively inexpensive and safe application to individuals with prediabetes appears warranted.

DOI: https://doi.org/10.1155/2022/5318245
Front Endocrinol (Lausanne). 2022 ;13 841788

Understanding the Mechanism of Dysglycemia in a Fanconi-Bickel Syndrome Patient.

Sanaa Sharari, Mustapha Aouida, Idris Mohammed, Basma Haris, Ajaz Ahmad Bhat, Iman Hawari, Sabah Nisar, Igor Pavlovski, Kabir H Biswas, Najeeb Syed, Selma Maacha, Jean-Charles Grivel, Maryam Saifaldeen, Johan Ericsson, Khalid Hussain.

  Fanconi-Bickel Syndrome (FBS) is a rare disorder of carbohydrate metabolism that is characterized mainly by the accumulation of glycogen in the liver and kidney. It is inherited as an autosomal recessive disorder caused by mutations in the SLC2A2 gene, which encodes for GLUT2. Patients with FBS have dysglycemia but the molecular mechanisms of dysglycemia are still not clearly understood. Therefore, we aimed to understand the underlying molecular mechanisms of dysglycemia in a patient with FBS. Genomic DNA was isolated from a peripheral blood sample and analyzed by whole genome and Sanger sequencing. CRISPR-Cas9 was used to introduce a mutation that mimics the patient's mutation in a human kidney cell line expressing GLUT2 (HEK293T). Mutant cells were used for molecular analysis to investigate the effects of the mutation on the expression and function of GLUT2, as well as the expression of other genes implicated in dysglycemia. The patient was found to have a homozygous nonsense mutation (c.901C>T, R301X) in the SLC2A2 gene. CRISPR-Cas9 successfully mimicked the patient's mutation in HEK293T cells. The mutant cells showed overexpression of a dysfunctional GLUT2 protein, resulting in reduced glucose release activity and enhanced intracellular glucose accumulation. In addition, other glucose transporters (SGLT1 and SGLT2 in the kidney) were found to be induced in the mutant cells. These findings suggest the last loops (loops 9-12) of GLUT2 are essential for glucose transport activity and indicate that GLUT2 dysfunction is associated with dysglycemia in FBS.

Keywords:  Fanconi-Bickel syndrome (FBS); clustered regularly interspaced short palindromic repeats (CRISPR)- Cas9; dysglycemia; glucose transporter 2 (GLUT2); sodium-glucose transport protein 2 (SGLT2)

DOI:  https://doi.org/10.3389/fendo.2022.841788
J Appl Phycol. 2022 ;34(3): 1227-1241

Glycogen, poly(3-hydroxybutyrate) and pigment accumulation in three Synechocystis strains when exposed to a stepwise increasing salt stress.

K Meixner, C Daffert, D Dalnodar, K Mrázová, K Hrubanová, V Krzyzanek, J Nebesarova, O Samek, Z Šedrlová, E Slaninova, P Sedláček, S Obruča, I Fritz.

  The cyanobacterial genus Synechocystis is of particular interest to science and industry because of its efficient phototrophic metabolism, its accumulation of the polymer poly(3-hydroxybutyrate) (PHB) and its ability to withstand or adapt to adverse growing conditions. One such condition is the increased salinity that can be caused by recycled or brackish water used in cultivation. While overall reduced growth is expected in response to salt stress, other metabolic responses relevant to the efficiency of phototrophic production of biomass or PHB (or both) have been experimentally observed in three Synechocystis strains at stepwise increasing salt concentrations. In response to recent reports on metabolic strategies to increase stress tolerance of heterotrophic and phototrophic bacteria, we focused particularly on the stress-induced response of Synechocystis strains in terms of PHB, glycogen and photoactive pigment dynamics. Of the three strains studied, the strain Synechocystis cf. salina CCALA192 proved to be the most tolerant to salt stress. In addition, this strain showed the highest PHB accumulation. All the three strains accumulated more PHB with increasing salinity, to the point where their photosystems were strongly inhibited and they could no longer produce enough energy to synthesize more PHB.

Keywords:  Glycogen; Pigments; Poly(3-hydroxybutyrate); Salt stress; Synechocystis sp.

DOI:  https://doi.org/10.1007/s10811-022-02693-3
Front Physiol. 2022 ;13 880513

High Starch in Diet Leads to Disruption of Hepatic Glycogen Metabolism and Liver Fibrosis in Largemouth Bass (Micropterus salmoides), Which is Mediated by the PI3K/Akt Signaling Pathway.

Liang Zhong, Hongli Liu, Haiqi Zhang, Weidong Zhang, Minghao Li, Ya Huang, Jiayun Yao, Xiaoli Huang, Yi Geng, Defang Chen, Ping Ouyang, Shiyong Yang, Wei Luo, Lizi Yin.

  Due to its special flavour and cheapness, starch is a source of nutrition for humans and most animals, some of whom even prefer to consume large amounts of starchy foods. However, the use of starch by carnivorous fish is limited and excessive starch intake can lead to liver damage, but the mechanism of damage is not clear. Therefore, in this study, two isonitrogenous and isolipid semi-pure diets, Z diet (0% starch) and G diet (22% starch), were formulated, respectively. The largemouth bass (M. salmoides) cultured in fiberglass tanks were randomly divided into two groups and fed the two diets for 45 days. Blood and liver were collected on day 30 and 45 for enzymology, histopathology, ultramicropathology, flow cytometry, and transcriptomics to investigate the damage of high starch on the liver of largemouth bass and its damage mechanism. The results showed that the high starch not affect the growth performance of largemouth bass. However, high starch caused a whitening of the liver and an increase in hepatopancreas index (HSI), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) in the serum. Histopathological observations showed that high starch led to severe vacuolisation, congestion, and moderate to severe necrotizing hepatitis in the liver. The high starch intake led to a significant increase in postprandial blood glucose and insulin in serum of largemouth bass, promoting the synthesis and accumulation of large amounts of hepatic glycogen in the liver, leading to the loss of hepatocyte organelles and inducing liver fibrosis. Meanwhile, high starch induced the production of oxidative stress and promoted apoptosis and necrosis of hepatocytes. Transcriptome analysis revealed that there were 10,927 and 2,656 unique genes in the G and Z groups, respectively. KEGG enrichment analysis showed that 19 pathways were significantly enriched, including those related to glucose metabolism and cell survival. Network mapping based on enrichment pathways and differential expressing genes showed the emergence of a regulatory network dominated by PI3K/Akt signaling pathway. This indicated that the PI3K/Akt signalling pathway plays a very important role in this process, regulating the liver injury caused by high starch. Our results provide a reference for the mechanism of liver injury caused by high starch, and the PI3K/Akt signalling pathway could be a potential therapeutic target for liver injury caused by high starch.

Keywords:  PI3K/Akt signaling pathway; glucose metabolic disorders; hepatic fibrosis; high starch diets; liver damage

DOI:  https://doi.org/10.3389/fphys.2022.880513
Sleep Med Clin. 2022 Jun;pii: S1556-407X(22)00024-8. [Epub ahead of print]17(2): 253-262

Sleep Deprivation and Circadian Disruption Stress, Allostasis, and Allostatic Load.

Bruce S McEwen, Ilia N Karatsoreos.

  Getting a good night's sleep seems a panacea for improving mood and cognition. These subjective impressions are supported by countless studies exploring the impacts of sleep (and sleep loss) on mental health, metabolism, and immune function. Similarly, being "out of phase" with local time, commonly experienced by shift workers of jet-lagged air travelers, demonstrates that there are both neural and physiologic effects of internal circadian (daily) time being misaligned with external environmental time. This article reviews these areas contextualized using the model of allostasis and allostatic load emphasizing the impact of this "wear and tear" on the brain and body.

Keywords:  Allostasis; Allostatic load; Circadian disruption; Glycogen; Hippocampus; Oxidative stress; Proinflammatory cytokines; Sleep deprivation

DOI:  https://doi.org/10.1016/j.jsmc.2022.03.005