bims-glecem 2024-02-18 papers

bims-glecem

Biomed News

on Glycogen metabolism in exercise, cancer and energy metabolism

Issue of 2024–02–18
eleven papers selected by
Dipsikha Biswas, Københavns Universitet

Glycogen metabolism-mediated intercellular communication in the tumor microenvironment influences liver cancer prognosis.
Hepatic glycogenesis antagonizes lipogenesis by blocking S1P via UDPG.
Intersubunit communication in glycogen phosphorylase influences substrate recognition at the catalytic sites.
Hyperglycemia - A culprit of podocyte pathology in the context of glycogen metabolism.
Effect of intracerebroventricular administration of alglucosidase alfa in two mouse models of Lafora disease: Relevance for clinical practice.
Bed-rest and exercise remobilization: Concurrent adaptations in muscle glucose and protein metabolism.
Treatment of infantile-onset Pompe disease in a rat model with muscle-directed AAV gene therapy.
DBS are suitable for 1,5-anhydroglucitol monitoring in GSD1b and G6PC3-deficient patients taking SGLT2 inhibitors to treat neutropenia.
HBV DNA polymerase regulates tumor cell glycogen to enhance the malignancy of HCC cells.
Disruption of Hepatic Mitochondrial Pyruvate and Amino Acid Metabolism Impairs Gluconeogenesis and Endurance Exercise Capacity in Mice.
Characterizing the effects of muscle-specific GSK3a/b reduction on murine muscle contractility and metabolism in female mice.

Oncol Res. 2024 ;32(3): 563-576

Glycogen metabolism-mediated intercellular communication in the tumor microenvironment influences liver cancer prognosis.

Yang Zhang, Nannan Qin, Xijun Wang, Rui Liang, Quan Liu, Ruoyi Geng, Tianxiao Jiang, Yunfei Liu, Jinwei Li.

  Glycogen metabolism plays a key role in the development of hepatocellular carcinoma (HCC), but the function of glycogen metabolism genes in the tumor microenvironment (TME) is still to be elucidated. Single-cell RNA-seq data were obtained from ten HCC tumor samples totaling 64,545 cells, and 65 glycogen metabolism genes were analyzed by a nonnegative matrix factorization (NMF). The prognosis and immune response of new glycogen TME cell clusters were predicted by using HCC and immunotherapy cohorts from public databases. HCC single-cell analysis was divided into fibroblasts, NT T cells, macrophages, endothelial cells, and B cells, which were separately divided into new cell clusters by glycogen metabolism gene annotation. Pseudo-temporal trajectory analysis demonstrated the temporal differentiation trajectory of different glycogen subtype cell clusters. Cellular communication analysis revealed extensive interactions between endothelial cells with glycogen metabolizing TME cell-related subtypes and different glycogen subtype cell clusters. SCENIC analysis of transcription factors upstream of TME cell clusters with different glycogen metabolism. In addition, TME cell clusters of glycogen metabolism were found to be enriched in expression in CAF subtypes, CD8 depleted, M1, and M2 types. Bulk-seq analysis showed the prognostic significance of glycogen metabolism-mediated TME cell clusters in HCC, while a significant immune response was found in the immunotherapy cohort in patients treated with immune checkpoint blockade (ICB), especially for CAFs, T cells, and macrophages. In summary, our study reveals for the first time that glycogen metabolism mediates intercellular communication in the hepatocellular carcinoma microenvironment while elucidating the anti-tumor mechanisms and immune prognostic responses of different subtypes of cell clusters.

Keywords:  Glycogen metabolism; Immunotherapy; Liver cancer; Metabolic map; Prognosis; Single-cell; Tumor microenvironment

DOI:  https://doi.org/10.32604/or.2023.029697
Science. 2024 Feb 16. 383(6684): eadi3332

Hepatic glycogenesis antagonizes lipogenesis by blocking S1P via UDPG.

Jie Chen, Yabo Zhou, Zhuohang Liu, Yan Lu, Yishen Jiang, Kexin Cao, Nannan Zhou, Dianheng Wang, Chaoqi Zhang, Ning Zhou, Keqing Shi, Lu Zhang, Li Zhou, Zhenfeng Wang, Huafeng Zhang, Ke Tang, Jingwei Ma, Jiadi Lv, Bo Huang.

The identification of mechanisms to store glucose carbon in the form of glycogen rather than fat in hepatocytes has important implications for the prevention of nonalcoholic fatty liver disease (NAFLD) and other chronic metabolic diseases. In this work, we show that glycogenesis uses its intermediate metabolite uridine diphosphate glucose (UDPG) to antagonize lipogenesis, thus steering both mouse and human hepatocytes toward storing glucose carbon as glycogen. The underlying mechanism involves transport of UDPG to the Golgi apparatus, where it binds to site-1 protease (S1P) and inhibits S1P-mediated cleavage of sterol regulatory element-binding proteins (SREBPs), thereby inhibiting lipogenesis in hepatocytes. Consistent with this mechanism, UDPG administration is effective at treating NAFLD in a mouse model and human organoids. These findings indicate a potential opportunity to ameliorate disordered fat metabolism in the liver.

DOI: https://doi.org/10.1126/science.adi3332
Amino Acids. 2024 Feb 10. 56(1): 14

Intersubunit communication in glycogen phosphorylase influences substrate recognition at the catalytic sites.

Nahori Kamada, Ayato Ikeda, Yasushi Makino, Hiroshi Matsubara.

  Glycogen phosphorylase (GP) is biologically active as a dimer of identical subunits, each activated by phosphorylation of the serine-14 residue. GP exists in three interconvertible forms, namely GPa (di-phosphorylated form), GPab (mono-phosphorylated form), and GPb (non-phosphorylated form); however, information on GPab remains scarce. Given the prevailing view that the two GP subunits collaboratively determine their catalytic characteristics, it is essential to conduct GPab characterization to gain a comprehensive understanding of glycogenolysis regulation. Thus, in the present study, we prepared rabbit muscle GPab from GPb, using phosphorylase kinase as the catalyst, and identified it using a nonradioactive phosphate-affinity gel electrophoresis method. Compared with the half-half GPa/GPb mixture, the as-prepared GPab showed a unique AMP-binding affinity. To further investigate the intersubunit communication in GP, its catalytic site was probed using pyridylaminated-maltohexaose (a maltooligosaccharide-based substrate comprising the essential dextrin structure for GP; abbreviated as PA-0) and a series of specifically modified PA-0 derivatives (substrate analogs lacking part of the essential dextrin structure). By comparing the initial reaction rates toward the PA-0 derivative (Vderivative) and PA-0 (VPA-0), we demonstrated that the Vderivative/VPA-0 ratio for GPab was significantly different from that for the half-half GPa/GPb mixture. This result indicates that the interaction between the two GP subunits significantly influences substrate recognition at the catalytic sites, thereby providing GPab its unique substrate recognition profile.

Keywords:  Chemical probing; Glycogen phosphorylase; Intersubunit communication; Phosphorylation regulation; Phospho–dephospho hybrid; Substrate recognition

DOI:  https://doi.org/10.1007/s00726-023-03362-6
Arch Biochem Biophys. 2024 Feb 11. pii: S0003-9861(24)00046-8. [Epub ahead of print] 109927

Hyperglycemia - A culprit of podocyte pathology in the context of glycogen metabolism.

Olga Żołnierkiewicz, Dorota Rogacka.

  Prolonged disruption in the balance of glucose can result in metabolic disorders. The kidneys play a significant role in regulating blood glucose levels. However, when exposed to chronic hyperglycemia, the kidneys' ability to handle glucose metabolism may be impaired, leading to an accumulation of glycogen. Earlier studies have shown that there can be a significant increase in glucose storage in the form of glycogen in the kidneys in diabetes. Podocytes play a crucial role in maintaining the integrity of filtration barrier. In diabetes, exposure to elevated glucose levels can lead to significant metabolic and structural changes in podocytes, contributing to kidney damage and the development of diabetic kidney disease. The accumulation of glycogen in podocytes is not a well-established phenomenon. However, a recent study has demonstrated the presence of glycogen granules in podocytes. This review delves into the intricate connections between hyperglycemia and glycogen metabolism within the context of the kidney, with special emphasis on podocytes. The aberrant storage of glycogen has the potential to detrimentally impact podocyte functionality and perturb their structural integrity. This review provides a comprehensive analysis of the alterations in cellular signaling pathways that may potentially lead to glycogen overproduction in podocytes.

Keywords:  Glycogen; Glycogen synthase; High glucose; Podocyte

DOI:  https://doi.org/10.1016/j.abb.2024.109927
Epilepsy Res. 2024 Feb 06. pii: S0920-1211(24)00032-9. [Epub ahead of print]200 107317

Effect of intracerebroventricular administration of alglucosidase alfa in two mouse models of Lafora disease: Relevance for clinical practice.

Luis Zafra-Puerta, Matthieu Colpaert, Nerea Iglesias-Cabeza, Daniel F Burgos, Gema Sánchez-Martín, Matthew S Gentry, Marina P Sánchez, Jose M Serratosa.

  Lafora disease is a rare and fatal form of progressive myoclonic epilepsy with onset during early adolescence. The disease is caused by mutations in EPM2A, encoding laforin, or EPM2B, encoding malin. Both proteins have functions that affect glycogen metabolism, including glycogen dephosphorylation by laforin and ubiquitination of enzymes involved in glycogen metabolism by malin. Lack of function of laforin or malin results in the accumulation of polyglucosan that forms Lafora bodies in the central nervous system and other tissues. Enzyme replacement therapy through intravenous administration of alglucosidase alfa (Myozyme®) has shown beneficial effects removing polyglucosan aggregates in Pompe disease. We evaluated the effectiveness of intracerebroventricular administration of alglucosidase alfa in the Epm2a-/- knock-out and Epm2aR240X knock-in mouse models of Lafora disease. Seven days after a single intracerebroventricular injection of alglucosidase alfa in 12-month-old Epm2a-/- and Epm2aR240X mice, the number of Lafora bodies was not reduced. Additionally, a prolonged infusion of alglucosidase alfa for 2 or 4 weeks in 6- and 9-month-old Epm2a-/- mice did not result in a reduction in the number of LBs or the amount of glycogen in the brain. These findings hold particular significance in guiding a rational approach to the utilization of novel therapies in Lafora disease.

Keywords:  Alglucosidase alfa; Glycogen storage disease; Intracerebroventricular treatment; Lafora body; Lafora disease

DOI:  https://doi.org/10.1016/j.eplepsyres.2024.107317
J Cachexia Sarcopenia Muscle. 2024 Feb 12.

Bed-rest and exercise remobilization: Concurrent adaptations in muscle glucose and protein metabolism.

Natalie F Shur, Elizabeth J Simpson, Hannah Crossland, Despina Constantin, Sally M Cordon, Dumitru Constantin-Teodosiu, Francis B Stephens, Matthew S Brook, Philip J Atherton, Kenneth Smith, Daniel J Wilkinson, Olivier E Mougin, Christopher Bradley, Ian A Macdonald, Paul L Greenhaff.

   BACKGROUND: Bed-rest (BR) of only a few days duration reduces muscle protein synthesis and induces skeletal muscle atrophy and insulin resistance, but the scale and juxtaposition of these events have not been investigated concurrently in the same individuals. Moreover, the impact of short-term exercise-supplemented remobilization (ESR) on muscle volume, protein turnover and leg glucose uptake (LGU) in humans is unknown.
METHODS: Ten healthy males (24 ± 1 years, body mass index 22.7 ± 0.6 kg/m2 ) underwent 3 days of BR, followed immediately by 3 days of ESR consisting of 5 × 30 maximal voluntary single-leg isokinetic knee extensions at 90°/s each day. An isoenergetic diet was maintained throughout the study (30% fat, 15% protein and 55% carbohydrate). Resting LGU was calculated from arterialized-venous versus venous difference across the leg and leg blood flow during the steady-state of a 3-h hyperinsulinaemic-euglycaemic clamp (60 mU/m2 /min) measured before BR, after BR and after remobilization. Glycogen content was measured in vastus lateralis muscle biopsy samples obtained before and after each clamp. Leg muscle volume (LMV) was measured using magnetic resonance imaging before BR, after BR and after remobilization. Cumulative myofibrillar protein fractional synthetic rate (FSR) and whole-body muscle protein breakdown (MPB) were measured over the course of BR and remobilization using deuterium oxide and 3-methylhistidine stable isotope tracers that were administered orally.
RESULTS: Compared with before BR, there was a 45% decline in insulin-stimulated LGU (P < 0.05) after BR, which was paralleled by a reduction in insulin-stimulated leg blood flow (P < 0.01) and removal of insulin-stimulated muscle glycogen storage. These events were accompanied by a 43% reduction in myofibrillar protein FSR (P < 0.05) and a 2.5% decrease in LMV (P < 0.01) during BR, along with a 30% decline in whole-body MPB after 2 days of BR (P < 0.05). Myofibrillar protein FSR and LMV were restored by 3 days of ESR (P < 0.01 and P < 0.01, respectively) but not by ambulation alone. However, insulin-stimulated LGU and muscle glycogen storage were not restored by ESR.
CONCLUSIONS: Three days of BR caused concurrent reductions in LMV, myofibrillar protein FSR, myofibrillar protein breakdown and insulin-stimulated LGU, leg blood flow and muscle glycogen storage in healthy, young volunteers. Resistance ESR restored LMV and myofibrillar protein FSR, but LGU and muscle glycogen storage remained depressed, highlighting divergences in muscle fuel and protein metabolism. Furthermore, ambulation alone did not restore LMV and myofibrillar protein FSR in the non-exercised contralateral limb, emphasizing the importance of exercise rehabilitation following even short-term BR.

Keywords:  human metabolism; immobilization; insulin sensitivity; leg glucose uptake; muscle atrophy; muscle gene expression; muscle glycogen storage; muscle protein breakdown; muscle protein synthesis; rehabilitation

DOI:  https://doi.org/10.1002/jcsm.13431
Mol Metab. 2024 Feb 10. pii: S2212-8778(24)00030-9. [Epub ahead of print] 101899

Treatment of infantile-onset Pompe disease in a rat model with muscle-directed AAV gene therapy.

Sergio Muñoz, Joan Bertolin, Veronica Jimenez, Maria Luisa Jaén, Miquel Garcia, Anna Pujol, Laia Vilà, Victor Sacristan, Elena Barbon, Giuseppe Ronzitti, Jihad El Andari, Warut Tulalamba, Quang Hong Pham, Jesus Ruberte, Thierry VandenDriessche, Marinee K Chuah, Dirk Grimm, Federico Mingozzi, Fatima Bosch.

   OBJECTIVE: Pompe disease (PD) is caused by deficiency of the lysosomal enzyme acid α-glucosidase (GAA), leading to progressive glycogen accumulation and severe myopathy with progressive muscle weakness. In the Infantile-Onset PD (IOPD), death generally occurs <1 year of age. There is no cure for IOPD. Mouse models of PD do not completely reproduce human IOPD severity. Our main objective was to generate the first IOPD rat model to assess an innovative muscle-directed adeno-associated viral (AAV) vector-mediated gene therapy.
METHODS: PD rats were generated by CRISPR/Cas9 technology. The novel highly myotropic bioengineered capsid AAVMYO3 and an optimized muscle-specific promoter in conjunction with a transcriptional cis-regulatory element were used to achieve robust Gaa expression in the entire muscular system. Several metabolic, molecular, histopathological, and functional parameters were measured.
RESULTS: PD rats showed early-onset widespread glycogen accumulation, hepato- and cardiomegaly, decreased body and tissue weight, severe impaired muscle function and decreased survival, closely resembling human IOPD. Treatment with AAVMYO3-Gaa vectors resulted in widespread expression of Gaa in muscle throughout the body, normalizing glycogen storage pathology, restoring muscle mass and strength, counteracting cardiomegaly and normalizing survival rate.
CONCLUSIONS: This gene therapy holds great potential to treat glycogen metabolism alterations in IOPD. Moreover, the AAV-mediated approach may be exploited for other inherited muscle diseases, which also are limited by the inefficient widespread delivery of therapeutic transgenes throughout the muscular system.

Keywords:  AAV; Gene therapy; Glycogen metabolism; Myopathies; Pompe disease; Rat model

DOI:  https://doi.org/10.1016/j.molmet.2024.101899
Mol Genet Metab. 2023 Nov;pii: S1096-7192(23)00342-6. [Epub ahead of print]140(3): 107712

DBS are suitable for 1,5-anhydroglucitol monitoring in GSD1b and G6PC3-deficient patients taking SGLT2 inhibitors to treat neutropenia.

Joseph P Dewulf, Nathalie Chevalier, Sandrine Marie, Maria Veiga-da-Cunha.

  Glycogen storage disease type Ib (GSD1b) and G6PC3-deficiency are rare autosomal recessive diseases caused by inactivating mutations in SLC37A4 (coding for G6PT) and G6PC3, respectively. Both diseases are characterized by neutropenia and neutrophil dysfunction due to the intracellular accumulation of 1,5-anhydroglucitol-6-phosphate (1,5-AG6P), a potent inhibitor of hexokinases. We recently showed that the use of SGLT2 inhibitor therapy to reduce tubular reabsorption of its precursor, 1,5-anhydroglucitol (1,5-AG), a glucose analog present in blood, successfully restored the neutropenia and neutrophil function in G6PC3-deficient and GSD1b patients. The intra-individual variability of response to the treatment and the need to adjust the dose during treatment, especially in pediatric populations, can only be efficiently optimized if the concentration of 1,5-AG in blood is monitored during treatment, together with the patients' clinical signs and symptoms. Monitoring the 1,5-AG levels would be greatly simplified if it could be performed on dry blood spots (DBS) which are easy to collect, store and transport. The challenge is to know if a suitable method can be developed to perform accurate and reproducible assays for 1,5-AG using DBS. Here, we describe and validate an assay that quantifies 1,5-AG in DBS using isotopic dilution quantitation by LC-MS/MS that should greatly facilitate patients' follow-up. 1,5-AG levels measured in plasma and DBS give comparable values. This assay was used to monitor the levels of 1,5-AG in DBS from 3 G6PC3-deficient and 6 GSD1b patients during treatment with SGLT2 inhibitors. We recommend this approach to verify the adequate therapeutical response and compliance to the treatment in G6PC3-deficient and GSD1b patients treated with SGLT2 inhibitors.

Keywords:  1,5-anhydroglucitol; Diabetes; Dried blood spots monitoring; G6PC3; GSD1B; Glifozins; Neutropenia; SGLT2 inhibitors

DOI:  https://doi.org/10.1016/j.ymgme.2023.107712
Hepatol Commun. 2024 Mar 01. pii: e0387. [Epub ahead of print]8(3):

HBV DNA polymerase regulates tumor cell glycogen to enhance the malignancy of HCC cells.

Xiaoqing Zhao, Chunqing Wang, Liqing Zhao, Zhongzheng Tian.

BACKGROUND: The essential function of HBV DNA polymerase (HBV-DNA-Pol) is to initiate viral replication by reverse transcription; however, the role of HBV-DNA-Pol in HBV-associated HCC has not been clarified. Glycogen phosphorylase L (PYGL) is a critical regulator of glycogenolysis and is involved in tumorigenesis, including HCC. However, it is unknown whether HBV-DNA-Pol regulates PYGL to contribute to HCC tumorigenesis.
METHODS: Bioinformatic analysis, real-time quantitative PCR, western blotting, and oncology functional assays were performed to determine the contribution of HBV-DNA-Pol and PYGL to HCC development and glycolysis. The mechanisms of co-immunoprecipitation and ubiquitination were employed to ascertain how HBV-DNA-Pol upregulated PYGL.
RESULTS: Overexpression of HBV-DNA-Pol enhanced HCC progression in vitro and in vivo. Mechanistically, HBV-DNA-Pol interacted with PYGL and increased PYGL protein levels by inhibiting PYGL ubiquitination, which was mediated by the E3 ligase TRIM21. HBV-DNA-Pol competitively impaired the binding of PYGL to TRIM21 due to its stronger binding affinity to TRIM21, suppressing the ubiquitination of PYGL. Moreover, HBV-DNA-Pol promoted glycogen decomposition by upregulating PYGL, which led to an increased flow of glucose into glycolysis, thereby promoting HCC development.
CONCLUSIONS: Our study reveals a novel mechanism by which HBV-DNA-Pol promotes HCC by controlling glycogen metabolism in HCC, establishing a direct link between HBV-DNA-Pol and the Warburg effect, thereby providing novel targets for HCC treatment and drug development.

DOI: https://doi.org/10.1097/HC9.0000000000000387
Am J Physiol Endocrinol Metab. 2024 Feb 14.

Disruption of Hepatic Mitochondrial Pyruvate and Amino Acid Metabolism Impairs Gluconeogenesis and Endurance Exercise Capacity in Mice.

Michael R Martino, Mohammad Habibi, Daniel Ferguson, Rita T Brookheart, John P Thyfault, Gretchen A Meyer, Louise Lantier, Curtis C Hughey, Brian N Finck.

  Exercise robustly increases the glucose demands of skeletal muscle. This demand is met not only by muscle glycogenolysis, but also by accelerated liver glucose production from hepatic glycogenolysis and gluconeogenesis to fuel mechanical work and prevent hypoglycemia during exercise. Hepatic gluconeogenesis during exercise is dependent on highly coordinated responses within and between muscle and liver. Specifically, exercise increases the rate at which gluconeogenic precursors such as pyruvate/lactate or amino acids are delivered from muscle to the liver, extracted by the liver, and channeled into glucose. Herein, we examined the effects of interrupting gluconeogenic efficiency and capacity on exercise performance by deleting hepatic mitochondrial pyruvate carrier 2 (MPC2) and/or alanine transaminase 2 (ALT2) in mice. We found that deletion of MPC2 or ALT2 alone did not significantly affect time to exhaustion or post-exercise glucose concentrations in treadmill exercise tests, but mice lacking both MPC2 and ALT2 in liver (DKO) reached exhaustion faster and exhibited lower circulating glucose during and after exercise. Use of ²H/¹³C metabolic flux analyses demonstrated that DKO mice exhibited lower endogenous glucose production owing to decreased glycogenolysis and gluconeogenesis at rest and during exercise. The decreased gluconeogenesis was accompanied by lower anaplerotic, cataplerotic, and TCA cycle fluxes. Collectively, these findings demonstrate that the transition of the liver to the gluconeogenic mode is critical for preventing hypoglycemia and sustaining performance during exercise. The results also illustrate the need for interorgan crosstalk during exercise as described by the Cahill and Cori cycles.

Keywords:  alanine transaminase; exercise; gluconeogenesis; mitochondrial pyruvate carrier

DOI:  https://doi.org/10.1152/ajpendo.00258.2023
Am J Physiol Cell Physiol. 2024 Feb 12.

Characterizing the effects of muscle-specific GSK3a/b reduction on murine muscle contractility and metabolism in female mice.

Briana L Hockey, Michael S Finch, Jessica L Braun, Ahmad Mohammad, Lucas A Maddalena, Rene Vandenboom, Jeffrey A Stuart, Brian D Roy, Rebecca E K MacPherson, Val A Fajardo.

  Dysregulation of skeletal muscle morphology and metabolism is associated with chronic diseases such as obesity and type 2 diabetes. The enzyme glycogen synthase kinase 3 (GSK3) is highly involved in skeletal muscle physiology and metabolism, acting as a negative regulator of muscle size, strength, adaptive thermogenesis, and glucose homeostasis. Correspondingly, we have shown that partial gene expression knockdown (~40%) of gsk3 specifically in skeletal muscle increases lean mass, reduces fat mass, and activates muscle-based adaptive thermogenesis via sarco(endo)plasmic reticulum Ca2+ (SERCA) uncoupling in male mice. However, the effects of partial GSK3 knockdown in female mice have yet to be investigated. Here, we examined the effects of muscle-specific GSK3 knockdown on body composition, muscle size and strength, and whole-body metabolism in female C57BL/6J mice. Our results show that GSK3 content is higher in the female soleus vs. the male soleus; however, there were no differences in the extensor digitorum longus (EDL). Furthermore, muscle-specific GSK3 knockdown did not alter body composition in female mice, nor did it alter daily energy expenditure, glucose/insulin tolerance, mitochondrial respiration, or the expression of the SERCA uncouplers sarcolipin and neuronatin. We also did not find any differences in soleus muscle size, strength, or fatigue resistance. In the EDL, we found an increase in cross-sectional area associated with an increase in absolute force production but there were no differences in fatigability. Therefore, our study highlights sex-differences in the response to genetic reduction of gsk3, with most of the effects previously observed in male mice being absent in females.

Keywords:  Energy expenditure; Force production; Muscle; Thermogenesis

DOI:  https://doi.org/10.1152/ajpcell.00398.2023