bims-glecem 2022-12-18 papers

bims-glecem

Biomed News

on Glycogen metabolism in exercise, cancer and energy metabolism

Issue of 2022–12–18
nine papers selected by
Dipsikha Biswas, Københavns Universitet

Lafora progressive myoclonus-epilepsy: Laforin targets malin to glycogen.
CRISPR-mediated generation and characterization of a Gaa homozygous c.1935C>A (p.D645E) Pompe disease knock-in mouse model recapitulating human infantile onset-Pompe disease.
Favorable outcome of empagliflozin treatment in two pediatric glycogen storage disease type 1b patients.
Investigating the Role of Endothelial Glycogen Synthase Kinase3α/β in Atherogenesis in Low Density Lipoprotein Receptor Knockout Mice.
Glycogen overload transforms the liver.
Inhibition of glycogen synthase kinase 3 by lithium, a mechanism in search of specificity.
Sonographic evaluations of the skeletal muscles in patients with Pompe disease.
Inhibition of GSK3β Promotes Proliferation and Suppresses Apoptosis of Porcine Muscle Satellite Cells.
Inhibition of glycogen synthase kinase-3-beta (GSK3β) blocks nucleocapsid phosphorylation and SARS-CoV-2 replication.

Dis Model Mech. 2022 Dec 13. pii: dmm.049802. [Epub ahead of print]

Lafora progressive myoclonus-epilepsy: Laforin targets malin to glycogen.

Sharmistha Mitra, Baozhi Chen, Peixiang Wang, Erin Chown, Mathew Dear, Dikran R Guisso, Ummay Mariam, Jun Wu, Emrah Gumusgoz, Berge A Minassian.

  Glycogen is the largest cytosolic macromolecule and kept in solution through a regular system of short branches allowing hydration. This structure was thought to solely require balanced glycogen synthase and branching enzyme activities. Deposition of overlong-branched glycogen in the fatal epilepsy Lafora disease (LD) indicated involvement of the LD gene products laforin and the E3 ubiquitin ligase malin in regulating glycogen structure. Laforin binds glycogen, and LD-causing mutations disrupt this binding, laforin-malin interactions, or malin's ligase activity, all indicating a critical role for malin. Neither malin's endogenous function nor location could to date be studied due to lack of suitable antibodies. We generated a mouse in which the native malin gene is tagged with the FLAG sequence. We show that the tagged gene expresses physiologically, malin localizes to glycogen, laforin and malin indeed interact, at glycogen, and that malin's presence at glycogen depends on laforin. These results, and mice, open the way to understanding unknown mechanisms of glycogen synthesis critical to LD, and potentially other much more common diseases due to incompletely understood defects in glycogen metabolism.

Keywords:  Lafora Body; Myoclonus; Polyglucosan

DOI:  https://doi.org/10.1242/dmm.049802
Sci Rep. 2022 Dec 14. 12(1): 21576

CRISPR-mediated generation and characterization of a Gaa homozygous c.1935C>A (p.D645E) Pompe disease knock-in mouse model recapitulating human infantile onset-Pompe disease.

Shih-Hsin Kan, Jeffrey Y Huang, Jerry Harb, Allisandra Rha, Nancy D Dalton, Chloe Christensen, Yunghang Chan, Jeremy Davis-Turak, Jonathan Neumann, Raymond Y Wang.

Pompe disease, an autosomal recessive disorder caused by deficient lysosomal acid α-glucosidase (GAA), is characterized by accumulation of intra-lysosomal glycogen in skeletal and oftentimes cardiac muscle. The c.1935C>A (p.Asp645Glu) variant, the most frequent GAA pathogenic mutation in people of Southern Han Chinese ancestry, causes infantile-onset Pompe disease (IOPD), presenting neonatally with severe hypertrophic cardiomyopathy, profound muscle hypotonia, respiratory failure, and infantile mortality. We applied CRISPR-Cas9 homology-directed repair (HDR) using a novel dual sgRNA approach flanking the target site to generate a Gaaem1935C>A knock-in mouse model and a myoblast cell line carrying the Gaa c.1935C>A mutation. Herein we describe the molecular, biochemical, histological, physiological, and behavioral characterization of 3-month-old homozygous Gaaem1935C>A mice. Homozygous Gaaem1935C>A knock-in mice exhibited normal Gaa mRNA expression levels relative to wild-type mice, had near-abolished GAA enzymatic activity, markedly increased tissue glycogen storage, and concomitantly impaired autophagy. Three-month-old mice demonstrated skeletal muscle weakness and hypertrophic cardiomyopathy but no premature mortality. The Gaaem1935C>A knock-in mouse model recapitulates multiple salient aspects of human IOPD caused by the GAA c.1935C>A pathogenic variant. It is an ideal model to assess innovative therapies to treat IOPD, including personalized therapeutic strategies that correct pathogenic variants, restore GAA activity and produce functional phenotypes.

DOI: https://doi.org/10.1038/s41598-022-25914-8
Front Pediatr. 2022 ;10 1071464

Favorable outcome of empagliflozin treatment in two pediatric glycogen storage disease type 1b patients.

Zufit Hexner-Erlichman, Maria Veiga-da-Cunha, Yoav Zehavi, Zahava Vadasz, Adi D Sabag, Sameh Tatour, Ronen Spiegel.

   Background: Glycogen storage disease type 1b (GSD1b) is an ultra-rare autosomal recessive disorder, caused by mutations in SLC37A4 gene. Affected patients present with episodes of fasting hypoglycemia and lactic acidosis, hepatomegaly, growth retardation, hyperlipidemia and renal impairment. In addition, patients present neutropenia, neutrophil dysfunction and oral, and skin infections as well as a significant predisposition to develop inflammatory bowel disease (IBD). Low neutrophil counts and function is related to the toxic accumulation of 1,5-anhydroglucitol-6-phosphate (1,5-AG6P). Recently, several reports have shown that off-label treatment with empagliflozin (EMPA), an inhibitor of the renal glucose transporter SGLT2, decreased blood 1,5-anhydroglucitol (1,5-AG), and neutrophil 1,5-AG6P, thus resulting in a new therapeutic option for neutropenia and neutrophil dysfunction in patients.
Methods: Off-label treatment with EMPA was established in two GSD1b patients after signed informed consent. The patients were followed clinically. We monitored neutrophil counts and function, 1,5-AG levels in plasma and its renal clearance before and during EMPA treatment.
Results: A 17 year-old girl who had long standing oral ulcers and developed IBD, requiring systemic steroid and regular granulocyte colony-stimulating factor (GCSF) therapy and an 8 year-old boy who had steady non healing oral lesions were treated with empagliflozin during 18-24 months. Treatment led to increase of neutrophil counts and function with substantial clinical improvement. This included remission of IBD in the first patient which allowed to discontinue both GCSF and steroid therapy and resolution of oral lesions in both patients. The concentration of 1,5-AG in blood was greatly decreased within two weeks of treatment and remained stable thereafter.
Conclusions: Repurposing of empagliflozin to treat neutropenia in two GSD1b patients was safe and resulted in the urinary excretion of 1,5-AG, the normalization of neutrophil function, and a remarkable improvement of neutropenia-related clinical traits. We showed for the first time that empagliflozin increases concomitantly the renal clearance of both 1,5-anhydroglucitol and glucose in GSD1b patients.

Keywords:  empagliflozin; glycogen storage disease type 1B; inflammatory bowel disease; neutropenia; neutrophil dysfunction

DOI:  https://doi.org/10.3389/fped.2022.1071464
Int J Mol Sci. 2022 Nov 26. pii: 14780. [Epub ahead of print]23(23):

Investigating the Role of Endothelial Glycogen Synthase Kinase3α/β in Atherogenesis in Low Density Lipoprotein Receptor Knockout Mice.

Lauren Mastrogiacomo, Geoff H Werstuck.

  Risk factors for developing cardiovascular disease (CVD) are associated with inflammation and endothelial activation. Activated endothelial cells (ECs) express adhesion proteins that recruit monocytes to the subendothelial layer initiating plaque development. Understanding the mechanism(s) by which ECs increase adhesion protein expression will facilitate the development of therapies aimed at preventing CVD progression and mortality. Glycogen synthase kinase (GSK)3α/β are constitutively active kinases which have been associated with many cellular pathways regulating cell viability and metabolism. While roles for myeloid GSK3α/β in the development of atherosclerosis have been established, there is limited knowledge on the potential roles of endothelial GSK3α/β. With the use of Cre recombinase technology, GSK3α/β was knocked out of both ECs and macrophages (Tie2Cre GSK3α/βfl/fl LDLR-/-). A bone marrow transplant was used to replenish GSK3α/β in the myeloid lineage allowing the assessment of an endothelial-selective GSK3α/β knockout (BMT Tie2Cre GSK3α/βfl/fl LDLR-/-). In both models, adhesion protein expression, macrophage recruitment and plaque volume were reduced in GSK3α knockout mice. GSK3β knockout had no significant effect. Results from this study are the first to suggest a pro-atherogenic role of endothelial GSK3α and support existing evidence for targeting GSK3α in the treatment of atherosclerotic CVD.

Keywords:  atherosclerosis; cardiovascular disease; endothelial activation; glycogen synthase kinase3

DOI:  https://doi.org/10.3390/ijms232314780
Acta Biochim Biophys Sin (Shanghai). 2022 Nov 25. 54(12): 1-3

Glycogen overload transforms the liver.

Peiyi Li, Tingting Qiu, Bolong Liu, Jianxin Zhang, Yehua Dai, Hong Zhao.

DOI: https://doi.org/10.3724/abbs.2022172
Front Mol Neurosci. 2022 ;15 1028963

Inhibition of glycogen synthase kinase 3 by lithium, a mechanism in search of specificity.

Dipashree Chatterjee, Jean Martin Beaulieu.

  Inhibition of Glycogen synthase kinase 3 (GSK3) is a popular explanation for the effects of lithium ions on mood regulation in bipolar disorder and other mental illnesses, including major depression, cyclothymia, and schizophrenia. Contribution of GSK3 is supported by evidence obtained from animal and patient derived model systems. However, the two GSK3 enzymes, GSK3α and GSK3β, have more than 100 validated substrates. They are thus central hubs for major biological functions, such as dopamine-glutamate neurotransmission, synaptic plasticity (Hebbian and homeostatic), inflammation, circadian regulation, protein synthesis, metabolism, inflammation, and mitochondrial functions. The intricate contributions of GSK3 to several biological processes make it difficult to identify specific mechanisms of mood stabilization for therapeutic development. Identification of GSK3 substrates involved in lithium therapeutic action is thus critical. We provide an overview of GSK3 biological functions and substrates for which there is evidence for a contribution to lithium effects. A particular focus is given to four of these: the transcription factor cAMP response element-binding protein (CREB), the RNA-binding protein FXR1, kinesin subunits, and the cytoskeletal regulator CRMP2. An overview of how co-regulation of these substrates may result in shared outcomes is also presented. Better understanding of how inhibition of GSK3 contributes to the therapeutic effects of lithium should allow for identification of more specific targets for future drug development. It may also provide a framework for the understanding of how lithium effects overlap with those of other drugs such as ketamine and antipsychotics, which also inhibit brain GSK3.

Keywords:  CREB; FXR1; bipolar disorder; collapsin response mediator protein 2; glycogen synthase kinase 3; kinesin; lithium

DOI:  https://doi.org/10.3389/fnmol.2022.1028963
Eur J Paediatr Neurol. 2022 Dec 06. pii: S1090-3798(22)00167-2. [Epub ahead of print]42 22-27

Sonographic evaluations of the skeletal muscles in patients with Pompe disease.

Yi-Hsiang Chiu, Chun-Li Liao, Yin-Hsiu Chien, Chueh-Hung Wu, Levent Özçakar.

   BACKGROUND: Pompe disease usually has muscle weakness due to glycogen accumulation. Heckmatt scale is commonly used to grade the pertinent findings of ultrasound. Nonetheless, it is difficult to detect subtle changes of the muscle. Besides, no ultrasonographic parameter has been proposed to predict the motor functions of Pompe disease. Therefore, we aimed to find out an ultrasonographic parameter that can quantify the muscle involvement and correlate with the motor functions in Pompe disease.
METHODS: Eighteen patients with Pompe disease were enrolled. The echo heterogeneity index (standard deviation divided by mean echogenicity values by ImageJ analysis) and shear modulus were recorded from rectus femoris, biceps femoris, tibialis anterior, medial gastrocnemius, biceps brachii and triceps brachii muscles. Motor functions, including manual muscle strength, 6-min walk and four-limb stair climb tests were assessed. Correlations between ultrasonographic parameters and Heckmatt scale and motor functions were analyzed.
RESULTS: The echo heterogeneity index, but not the shear modulus, was negatively correlated with the Heckmatt scale rating in all muscles. The echo heterogeneity indices of tibialis anterior (r = 0.698, p = 0.008) and medial gastrocnemius (r = 0.615, p = 0.025) muscles showed positive correlations with the walking distance. Besides, the echo heterogeneity indices of four lower limb muscles were negatively correlated with the duration of stair climbing.
CONCLUSION: The echo heterogeneity index but not the shear modulus can be used to quantitatively describe the muscle involvement in Pompe disease. In addition, lower echo heterogeneity indices of lower limb muscles are associated with worse motor functions in these patients.

Keywords:  Elastography; Heckmatt scale; Motor function; Muscle ultrasound; Pompe disease

DOI:  https://doi.org/10.1016/j.ejpn.2022.12.002
Animals (Basel). 2022 Nov 28. pii: 3328. [Epub ahead of print]12(23):

Inhibition of GSK3β Promotes Proliferation and Suppresses Apoptosis of Porcine Muscle Satellite Cells.

Jinryong Park, Hyunwoo Choi, Kwanseob Shim.

  As the global population increases, interest in cultured meat (a new research field) is gradually increasing. The main raw material for the production of cultured meat is muscle stem cells called satellite cells isolated from livestock. However, how to mass proliferate and maintain satellite cells in vitro without genetic manipulation remains unclear. In the present study, we isolated and purified porcine muscle satellite cells (PMSCs) from the femur of a 1-day-old piglet and cultured PMSCs by treating them with an inhibitor (XAV939, Tankyrase (TNKS) inhibitor) or an activator (CHIR99021, glycogen synthase kinase 3 beta (GSK3β) inhibitor) of Wnt signaling. The CHIR group treated with 3 μM CHIR99021 showed a significantly increased proliferation rate of PMSCs compared to the SC group (control), whereas the XAV group treated with 1 μM XAV939 showed a significantly decreased proliferation rate of PMSCs. CHIR99021 also inhibited the differentiation of PMSCs by reducing the expression of MyoD while maintaining the expression of Pax7 and suppressed apoptosis by regulating the expression of apoptosis-related proteins and genes. RNA sequencing was performed to obtain gene expression profiles following inhibition or activation of the Wnt signaling pathway and various signaling mechanisms related to the maintenance of satellite cells were identified. Our results suggest that inhibition of GSK3β could dramatically improve the maintenance and mass proliferation ability of PMSCs in vitro by regulating the expression of myogenic markers and the cell cycle.

Keywords:  Wnt signaling pathway; maintenance; porcine; proliferation; satellite cell

DOI:  https://doi.org/10.3390/ani12233328
Mol Biomed. 2022 Dec 12. 3(1): 43

Inhibition of glycogen synthase kinase-3-beta (GSK3β) blocks nucleocapsid phosphorylation and SARS-CoV-2 replication.

Tirosh Shapira, Selvarani Vimalanathan, Celine Rens, Virginia Pichler, Sandra Peña-Díaz, Grace Jordana, William Rees, Dirk F H Winkler, Iqbal Sarai, Theodore Steiner, François Jean, Steven Pelech, Yossef Av-Gay.

  GSK3β has been proposed to have an essential role in Coronaviridae infections. Screening of a targeted library of GSK3β inhibitors against both SARS-CoV-2 and HCoV-229E to identify broad-spectrum anti-Coronaviridae inhibitors resulted in the identification of a high proportion of active compounds with low toxicity to host cells. A selected lead compound, T-1686568, showed low micromolar, dose-dependent activity against SARS-CoV-2 and HCoV-229E. T-1686568 showed efficacy in viral-infected cultured cells and primary 2D organoids. T-1686568 also inhibited SARS-CoV-2 variants of concern Delta and Omicron. Importantly, while inhibition by T-1686568 resulted in the overall reduction of viral load and protein translation, GSK3β inhibition resulted in cellular accumulation of the nucleocapsid protein relative to the spike protein. Following identification of potential phosphorylation sites of Coronaviridae nucleocapsid, protein kinase substrate profiling assays combined with Western blotting analysis of nine host kinases showed that the SARS-CoV-2 nucleocapsid could be phosphorylated by GSK3β and PKCa. GSK3β phosphorylated SARS-CoV-2 nucleocapsid on the S180/S184, S190/S194 and T198 phospho-sites, following previous priming in the adjacent S188, T198 and S206, respectively. Such inhibition presents a compelling target for broad-spectrum anti-Coronaviridae compound development, and underlies the mechanism of action of GSK3β host-directed therapy against this class of obligate intracellular pathogens.

Keywords:  Antivirals; GSK3β; Host-directed therapy; Host-pathogen interactions; SARS-CoV-2

DOI:  https://doi.org/10.1186/s43556-022-00111-1