bims-glecem 2022-06-19 papers

bims-glecem

Biomed News

on Glycogen metabolism in exercise, cancer and energy metabolism

Issue of 2022–06–19
eight papers selected by
Dipsikha Biswas, Københavns Universitet

Mechanism of glycogen synthase inactivation and interaction with glycogenin.
Stbd1-deficient mice display insulin resistance associated with enhanced hepatic ER-mitochondria contact.
GFPT1-Associated Congenital Myasthenic Syndrome Mimicking a Glycogen Storage Disease - Diagnostic Pitfalls in Myopathology Solved by Next-Generation-Sequencing.
A 78-year-old Japanese male with late-onset PHKA1-associated distal myopathy: Case report and literature review.
Synthesis and biological evaluation of thieno[3,2-c]pyrazol-3-amine derivatives as potent glycogen synthase kinase 3β inhibitors for Alzheimer's disease.
Glycogen Synthase Kinase-3 (GSK-3) Regulation of Inhibitory Coreceptor Expression in T-cell Immunity.
Metabolic Reprogramming Mediates Delayed Apoptosis of Human Neutrophils Infected With Francisella tularensis.
4-Hydroxybenzoic Acid and β-Sitosterol from Cucurbita ficifolia Act as Insulin Secretagogues, Peroxisome Proliferator-Activated Receptor-Gamma Agonists, and Liver Glycogen Storage Promoters: In Vivo, In Vitro, and In Silico Studies.

Nat Commun. 2022 Jun 11. 13(1): 3372

Mechanism of glycogen synthase inactivation and interaction with glycogenin.

Laura Marr, Dipsikha Biswas, Leonard A Daly, Christopher Browning, Sarah C M Vial, Daniel P Maskell, Catherine Hudson, Jay A Bertrand, John Pollard, Neil A Ranson, Heena Khatter, Claire E Eyers, Kei Sakamoto, Elton Zeqiraj.

Glycogen is the major glucose reserve in eukaryotes, and defects in glycogen metabolism and structure lead to disease. Glycogenesis involves interaction of glycogenin (GN) with glycogen synthase (GS), where GS is activated by glucose-6-phosphate (G6P) and inactivated by phosphorylation. We describe the 2.6 Å resolution cryo-EM structure of phosphorylated human GS revealing an autoinhibited GS tetramer flanked by two GN dimers. Phosphorylated N- and C-termini from two GS protomers converge near the G6P-binding pocket and buttress against GS regulatory helices. This keeps GS in an inactive conformation mediated by phospho-Ser641 interactions with a composite "arginine cradle". Structure-guided mutagenesis perturbing interactions with phosphorylated tails led to increased basal/unstimulated GS activity. We propose that multivalent phosphorylation supports GS autoinhibition through interactions from a dynamic "spike" region, allowing a tuneable rheostat for regulating GS activity. This work therefore provides insights into glycogen synthesis regulation and facilitates studies of glycogen-related diseases.

DOI: https://doi.org/10.1038/s41467-022-31109-6
Biochimie. 2022 Jun 09. pii: S0300-9084(22)00165-1. [Epub ahead of print]

Stbd1-deficient mice display insulin resistance associated with enhanced hepatic ER-mitochondria contact.

Styliana Kyriakoudi, Andria Theodoulou, Louiza Potamiti, Fabian Schumacher, Margarita Zachariou, Revekka Papacharalambous, Burkhard Kleuser, Mihalis I Panayiotidis, Anthi Drousiotou, Petros P Petrou.

  Starch binding domain-containing protein 1 (STBD1) is an endoplasmic reticulum (ER)-resident, glycogen-binding protein. In addition to glycogen, STBD1 has been shown to interact with several proteins implicated in glycogen synthesis and degradation, yet its function in glycogen metabolism remains largely unknown. In addition to the bulk of the ER, STBD1 has been reported to localize at regions of physical contact between mitochondria and the ER, known as Mitochondria-ER Contact sites (MERCs). Given the emerging correlation between distortions in the integrity of hepatic MERCs and insulin resistance, our study aimed to delineate the role of STBD1 in vivo by addressing potential abnormalities in glucose metabolism and ER-mitochondria communication associated with insulin resistance in mice with targeted inactivation of Stbd1 (Stbd1KO). We show that Stbd1KO mice at the age of 24 weeks displayed reduced hepatic glycogen content and aberrant control of glucose homeostasis, compatible with insulin resistance. In line with the above, Stbd1-deficient mice presented with increased fasting blood glucose and insulin levels, attenuated activation of insulin signaling in the liver and skeletal muscle and elevated liver sphingomyelin content, in the absence of hepatic steatosis. Furthermore, Stbd1KO mice were found to exhibit enhanced ER-mitochondria association and increased mitochondrial fragmentation in the liver. Nevertheless, the enzymatic activity of hepatic respiratory chain complexes and ER stress levels in the liver were not altered. Our findings identify a novel important role for STBD1 in the control of glucose metabolism, associated with the integrity of hepatic MERCs.

Keywords:  Glycogen; Insulin resistance; Mice; Mitochondria-ER contact Sites; Mitochondrial fragmentation; STBD1

DOI:  https://doi.org/10.1016/j.biochi.2022.06.003
J Neuromuscul Dis. 2022 Jun 04.

GFPT1-Associated Congenital Myasthenic Syndrome Mimicking a Glycogen Storage Disease - Diagnostic Pitfalls in Myopathology Solved by Next-Generation-Sequencing.

Alexander Mensch, Isabell Cordts, Leila Scholle, Pushpa Raj Joshi, Kathleen Kleeberg, Alexander Emmer, Stefanie Beck-Woedl, Joohyun Park, Tobias B Haack, Gisela Stoltenburg-Didinger, Stephan Zierz, Marcus Deschauer.

  GFPT1-related congenital myasthenic syndrome (CMS) is characterized by progressive limb girdle weakness, and less prominent involvement of facial, bulbar, or respiratory muscles. While tubular aggregates in muscle biopsy are considered highly indicative in GFPT1-associated CMS, excessive glycogen storage has not been described. Here, we report on three affected siblings with limb-girdle myasthenia due to biallelic pathogenic variants in GFPT1: the previously reported missense variant c.41G > A (p.Arg14Gln) and the novel truncating variant c.1265_1268del (p.Phe422TrpfsTer26). Patients showed progressive proximal atrophic muscular weakness with respiratory involvement, and a lethal disease course in adulthood. In the diagnostic workup at that time, muscle biopsy suggested a glycogen storage disease. Initially, Pompe disease was suspected. However, enzymatic activity of acid alpha-glucosidase was normal, and gene panel analysis including 38 genes associated with limb-girdle weakness (GAA included) remained unevocative. Hence, a non-specified glycogen storage myopathy was diagnosed. A decade later, the diagnosis of GFPT1-related CMS was established by genome sequencing. Myopathological reexamination showed pronounced glycogen accumulations, that were exclusively found in denervated muscle fibers. Only single fibers showed very small tubular aggregates, identified in evaluation of serial sections. This family demonstrates how diagnostic pitfalls can be addressed by an integrative approach including broad genetic analysis and re-evaluation of clinical as well as myopathological findings.

Keywords:  CMS; LGMD; autophagy; glycogen storage disease; vacuoles

DOI:  https://doi.org/10.3233/JND-220822
Neuromuscul Disord. 2022 May 24. pii: S0960-8966(22)00147-X. [Epub ahead of print]

A 78-year-old Japanese male with late-onset PHKA1-associated distal myopathy: Case report and literature review.

Madoka Mori-Yoshimura, Kazutaka Aizawa, Yasushi Oya, Yoshihiko Saito, Tokiko Fukuda, Hideo Sugie, Ichizo Nishino, Yuji Takahashi.

  PHKA1 mutations are causative for glycogen storage disease type IXd (GSDIXd), a myopathy that can be asymptomatic or associated with exercise intolerance, and rarely is accompanied by weakness or atrophy of limbs. Here we report a patient with GSDIXd who developed distal myopathy which was not accompanied by exercise intolerance at age 71. Muscle MRI revealed severe but gradual involvement of muscles with disease progression in the order of medial gastrocnemius, soleus, lateral gastrocnemius, and gluteus muscles. Muscle pathology revealed vacuolar changes with glycogen accumulation, and muscle enzymatic activity of phosphorylase b kinase was markedly decreased to 1.5 nmol of substrate utilized/min/mg protein (normal range: 39.5 ± 10.8). Collectively, the present findings suggest that PHKA1-associated distal myopathy is an adult-onset distal calf dominant myopathy which does not always present with exercise intolerance.

Keywords:  Adult-onset distal myopathy; Glycogen storage disease type IXd (GSDIXd); Phosphorylase kinase (PHKA1)

DOI:  https://doi.org/10.1016/j.nmd.2022.05.010
J Enzyme Inhib Med Chem. 2022 Dec;37(1): 1724-1736

Synthesis and biological evaluation of thieno[3,2-c]pyrazol-3-amine derivatives as potent glycogen synthase kinase 3β inhibitors for Alzheimer's disease.

Ning Yan, Xiao-Long Shi, Long-Qian Tang, De-Feng Wang, Xun Li, Chao Liu, Zhao-Peng Liu.

  Glycogen synthase kinase 3β (GSK-3β) catalyses the hyperphosphorylation of tau protein in the Alzheimer's disease (AD) pathology. A series of novel thieno[3,2-c]pyrazol-3-amine derivatives were designed and synthesised and evaluated as potential GSK-3β inhibitors by structure-guided drug rational design approach. The thieno[3,2-c]pyrazol-3-amine derivative 16b was identified as a potent GSK-3β inhibitor with an IC50 of 3.1 nM in vitro and showed accepted kinase selectivity. In cell levels, 16b showed no toxicity on the viability of SH-SY5Y cells at the concentration up to 50 μM and targeted GSK-3β with the increased phosphorylated GSK-3β at Ser9. Western blot analysis indicated that 16b decreased the phosphorylated tau at Ser396 in a dose-dependent way. Moreover, 16b effectively increased expressions of β-catenin as well as the GAP43, N-myc, and MAP-2, and promoted the differentiated neuronal neurite outgrowth. Therefore, the thieno[3,2-c]pyrazol-3-amine derivative 16b could serve as a promising GSK-3β inhibitor for the treatment of AD.

Keywords:   neurite outgrowth; Alzheimer’s disease; Aβ; GSK-3β inhibitors; tau hyperphosphorylation

DOI:  https://doi.org/10.1080/14756366.2022.2086867
J Cell Immunol. 2021 ;3(5): 336-342

Glycogen Synthase Kinase-3 (GSK-3) Regulation of Inhibitory Coreceptor Expression in T-cell Immunity.

Mark E Issa, Christopher E Rudd.

The serine/threonine kinase, glycogen synthase kinase 3 (GSK-3) has been implicated in immune cell activation and function. Our recent studies have shown that the abrogation of GSK-3 activity down-regulates the expression of key inhibitory receptors PD-1 and LAG-3. It also regulates the expression of the transcription factor NFAT which, in turn, is responsible for inhibiting PD-1/LAG-3 transcription as well as activating the expression of cytolytic effector proteins such as perforin and granzyme B. The role of components of the Wnt signaling pathway in these events remains to be fully uncovered. This mini-review discusses the recent discoveries that have elucidated the role of the GSK-3 signaling pathway in cancer immunotherapy.

DOI: https://doi.org/10.33696/immunology.3.115
Front Immunol. 2022 ;13 836754

Metabolic Reprogramming Mediates Delayed Apoptosis of Human Neutrophils Infected With Francisella tularensis.

Samantha J Krysa, Lee-Ann H Allen.

  Neutrophils (polymorphonuclear leukocytes, PMNs) have a distinctively short lifespan, and tight regulation of cell survival and death is imperative for their normal function. We demonstrated previously that Francisella tularensis extends human neutrophil lifespan, which elicits an impaired immune response characterized by neutrophil dysfunction. Herein, we extended these studies, including our transcriptional profiling data, and employed Seahorse extracellular flux analysis, gas chromatography-mass spectrometry metabolite analysis, flow cytometry and several other biochemical approaches to demonstrate that the delayed apoptosis observed in F. tularensis-infected neutrophils is mediated, in part, by metabolic reprogramming. Specifically, we show that F. tularensis-infected neutrophils exhibited a unique metabolic signature characterized by increased glycolysis, glycolytic flux and glucose uptake, downregulation of the pentose phosphate pathway, and complex glycogen dynamics. Glucose uptake and glycolysis were essential for cell longevity, although glucose-6-phosphate translocation into the endoplasmic reticulum was not, and we identify depletion of glycogen as a potential trigger of apoptosis onset. In keeping with this, we also demonstrate that ablation of apoptosis with the pan-caspase inhibitor Q-VD-OPh was sufficient to profoundly increase glycolysis and glycogen stores in the absence of infection. Taken together, our data significantly advance understanding of neutrophil immunometabolism and its capacity to regulate cell lifespan.

Keywords:  Francisella tularensis; apoptosis; glycogen; glycolysis; immunometabolism; neutrophils (PMNs)

DOI:  https://doi.org/10.3389/fimmu.2022.836754
J Med Food. 2022 Jun;25(6): 588-596

4-Hydroxybenzoic Acid and β-Sitosterol from Cucurbita ficifolia Act as Insulin Secretagogues, Peroxisome Proliferator-Activated Receptor-Gamma Agonists, and Liver Glycogen Storage Promoters: In Vivo, In Vitro, and In Silico Studies.

Wendoline Rosiles-Alanis, Alejandro Zamilpa, Rebeca García-Macedo, Miguel A Zavala-Sánchez, Sergio Hidalgo-Figueroa, Beatriz Mora-Ramiro, Rubén Román-Ramos, Samuel E Estrada-Soto, Julio C Almanza-Perez.

  Insulin secretion and GLUT4 expression are two critical events in glucose regulation. The receptors G-protein-coupled receptor 40 (GPR40) and peroxisome proliferator-activated receptor-gamma (PPARγ) modulate these processes, and they represent potential therapeutic targets for new antidiabetic agent's design. Cucurbita ficifolia fruit is used in traditional medicine for diabetes control. Previous studies demonstrated several effects: a hypoglycemic effect mediated by an insulin secretagogue action, antihyperglycemic effect, and promoting liver glycogen storage. Anti-inflammatory and antioxidant effects were also reported. Moreover, some of its phytochemicals have been described, including d-chiro-inositol. However, to understand these effects integrally, other active principles should be investigated. The aim was to perform a chemical fractionation guided by bioassay to isolate and identify other compounds from C. ficifolia fruit that explain its hypoglycemic action as insulin secretagogue, its antihyperglycemic effect by PPARγ activation, and on liver glycogen storage. Three different preparations of C. ficifolia were tested in vivo. Ethyl acetate fraction derived from aqueous extract showed antihyperglycemic effect in an oral glucose tolerance test and was further fractioned. The insulin secretagogue action was tested in RINm5F cells. For the PPARγ activation, C2C12 myocytes were treated with the fractions, and GLUT4 mRNA expression was measured. Chemical fractionation resulted in the isolation and identification of β-sitosterol and 4-hydroxybenzoic acid (4-HBA), which increased insulin secretion, GLUT4, PPARγ, and adiponectin mRNA expression, in addition to an increase in glycogen storage. 4-HBA exhibited an antihyperglycemic effect, while β-sitosterol showed hypoglycemic effect, confirming the wide antidiabetic related results we found in our in vitro models. An in silico study revealed that 4-HBA and β-sitosterol have potential as dual agonists on PPARγ and GPR40 receptors. Both compounds should be considered in the development of new antidiabetic drug development.

Keywords:  4-hydroxybenzoic acid; Cucurbita ficifolia; Cucurbitaceae; GLUT4; PPARγ; diabetes mellitus; glycogen storage; insulin secretagogue; β-sitosterol

DOI:  https://doi.org/10.1089/jmf.2021.0071