scholarly journals Validating GSK3 as an in vivo target of lithium action

2009 ◽  
Vol 37 (5) ◽  
pp. 1133-1138 ◽  
Author(s):  
W. Timothy O'Brien ◽  
Peter S. Klein
Keyword(s):  
Glycogen Synthase ◽  
Insulin Signalling ◽  
Lithium Treatment ◽  
Glycogen Synthesis ◽  
Model Systems ◽  
Glycogen Synthase Kinase 3 ◽  
Therapeutic Effects ◽  
Inositol Monophosphatase ◽  
Direct Target

Lithium is widely used to treat bipolar disorder, but its mechanism of action in this disorder is unknown. Lithium directly inhibits GSK3 (glycogen synthase kinase 3), a critical regulator of multiple signal transduction pathways. Inhibition of GSK3 provides a compelling explanation for many of the known effects of lithium, including effects on early development and insulin signalling/glycogen synthesis. However, lithium also inhibits inositol monophosphatase, several structurally related phosphomonoesterases, phosphoglucomutase and the scaffolding function of β-arrestin-2. It is not known which of these targets is responsible for the behavioural or therapeutic effects of lithium in vivo. The present review discusses basic criteria that can be applied to model systems to validate a proposed direct target of lithium. In this context, we describe a set of simple behaviours in mice that are robustly affected by chronic lithium treatment and are similarly affected by structurally diverse GSK3 inhibitors and by removing one copy of the Gsk3b gene. These observations, from several independent laboratories, support a central role for GSK3 in mediating behavioural responses to lithium.

scholarly journals GSK-3β in Pancreatic Cancer: Spotlight on 9-ING-41, Its Therapeutic Potential and Immune Modulatory Properties

Biology ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 610
Author(s):  
Robin Park ◽  
Andrew L. Coveler ◽  
Ludimila Cavalcante ◽  
Anwaar Saeed
Keyword(s):  
Pancreatic Cancer ◽  
Therapeutic Potential ◽  
Glycogen Synthase ◽  
Glycogen Synthase Kinase ◽  
Glycogen Synthase Kinase 3 ◽  
In Vivo Models ◽  
Gsk 3Β ◽  
Early Phase Clinical Trials

Glycogen synthase kinase-3 beta is a ubiquitously and constitutively expressed molecule with pleiotropic function. It acts as a protooncogene in the development of several solid tumors including pancreatic cancer through its involvement in various cellular processes including cell proliferation, survival, invasion and metastasis, as well as autophagy. Furthermore, the level of aberrant glycogen synthase kinase-3 beta expression in the nucleus is inversely correlated with tumor differentiation and survival in both in vitro and in vivo models of pancreatic cancer. Small molecule inhibitors of glycogen synthase kinase-3 beta have demonstrated therapeutic potential in pre-clinical models and are currently being evaluated in early phase clinical trials involving pancreatic cancer patients with interim results showing favorable results. Moreover, recent studies support a rationale for the combination of glycogen synthase kinase-3 beta inhibitors with chemotherapy and immunotherapy, warranting the evaluation of novel combination regimens in the future.

scholarly journals Propofol attenuates lung ischemia/reperfusion injury though the involvement of the MALAT1/microRNA-144/GSK3β axis

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Jian-Ping Zhang ◽  
Wei-Jing Zhang ◽  
Miao Yang ◽  
Hua Fang
Keyword(s):  
Cell Apoptosis ◽  
Ischemia Reperfusion Injury ◽  
Glycogen Synthase ◽  
Ischemia Reperfusion ◽  
Inflammatory Factors ◽  
Therapeutic Effects ◽  
Protective Effects ◽  
Loss Of Function

Abstract Background Propofol, an intravenous anesthetic, was proven to protect against lung ischemia/reperfusion (I/R) injury. However, the detailed mechanism of Propofol in lung I/R injury is still elusive. This study was designed to explore the therapeutic effects of Propofol, both in vivo and in vitro, on lung I/R injury and the underlying mechanisms related to metastasis-associated lung adenocarcinoma transcript 1 (MALAT1)/microRNA-144 (miR-144)/glycogen synthase kinase-3β (GSK3β). Methods C57BL/6 mice were used to establish a lung I/R injury model while pulmonary microvascular endothelial cells (PMVECs) were constructed as hypoxia/reperfusion (H/R) cellular model, both of which were performed with Propofol treatment. Gain- or loss-of-function approaches were subsequently employed, followed by observation of cell apoptosis in lung tissues and evaluation of proliferative and apoptotic capabilities in H/R cells. Meanwhile, the inflammatory factors, autophagosomes, and autophagy-related proteins were measured. Results Our experimental data revealed that Propofol treatment could decrease the elevated expression of MALAT1 following I/R injury or H/R induction, indicating its protection against lung I/R injury. Additionally, overexpressing MALAT1 or GSK3β promoted the activation of autophagosomes, proinflammatory factor release, and cell apoptosis, suggesting that overexpressing MALAT1 or GSK3β may reverse the protective effects of Propofol against lung I/R injury. MALAT1 was identified to negatively regulate miR-144 to upregulate the GSK3β expression. Conclusion Overall, our study demonstrated that Propofol played a protective role in lung I/R injury by suppressing autophagy and decreasing release of inflammatory factors, with the possible involvement of the MALAT1/miR-144/GSK3β axis.

Lithium Pharmacology and a Potential Role of Lithium on Methamphetamine Abuse and Dependence

2019 ◽  
Vol 11 (2) ◽  
pp. 85-91 ◽  
Author(s):  
Nobue Kitanaka ◽  
Frank Scott Hall ◽  
George Richard Uhl ◽  
Junichi Kitanaka
Keyword(s):  
Molecular Mechanisms ◽  
Behavioral Sensitization ◽  
Tryptophan Hydroxylase ◽  
Glycogen Synthase ◽  
Lithium Treatment ◽  
Glycogen Synthase Kinase ◽  
Therapeutic Effects ◽  
Potential Candidate ◽  
Glycogen Synthase Kinase 3Β ◽  
Methamphetamine Abuse

Background:The effectiveness of lithium salts in neuropsychiatric disorders such as bipolar disorder, Alzheimer’s disease, and treatment-resistant depression has been documented in an extensive scientific literature. Lithium inhibits inositol monophosphatase, inositol polyphosphate 1- phosphatase, and glycogen synthase kinase-3 and decreases expression level of tryptophan hydroxylase 2, conceivably underlying the mood stabilizing effects of lithium, as well as procognitive and neuroprotective effects. However, the exact molecular mechanisms of action of lithium on mood stabilizing and pro-cognitive effects in humans are still largely unknown.Objective:On the basis of the known aspects of lithium pharmacology, this review will discuss the possible mechanisms underlying the therapeutic effects of lithium on positive symptoms of methamphetamine abuse and dependence.Conclusion:It is possible that lithium treatment reduces the amount of newly synthesized phosphatidylinositol, potentially preventing or reversing neuroadaptations contributing to behavioral sensitization induced by methamphetamine. In addition, it is suggested that exposure to repeated doses of methamphetamine induces hyperactivation of glycogen synthase kinase-3β in the nucleus accumbens and in dorsal hippocampus, resulting in a long-term alterations in synaptic plasticity underlying behavioral sensitization as well as other behavioral deficits in memory-related behavior. Therefore it is clear that glycogen synthase kinase-3β inhibitors can be considered as a potential candidate for the treatment of methamphetamine abuse and dependence.

scholarly journals Acute elevation of circulating fatty acids impairs downstream insulin signalling in rat skeletal muscle in vivo independent of effects on stress signalling

2008 ◽  
Vol 197 (2) ◽  
pp. 277-285 ◽  
Author(s):  
Georgia Frangioudakis ◽  
Gregory J Cooney
Keyword(s):  
Kinase Inhibitor ◽  
Glycogen Synthase ◽  
Insulin Signalling ◽  
Plasma Free Fatty Acid ◽  
Nuclear Factor Κb ◽  
Quadriceps Muscle ◽  
Male Wistar Rats ◽  
Gsk 3Β ◽  
Stress Signalling

The aim of this study was to examine the effect of an acute, physiological increase in plasma free fatty acid (FFA) on initial signalling events in rat red quadriceps muscle (RQ). Male Wistar rats received a 7% glycerol (GLYC) or 7% Intralipid/heparin (LIP) infusion for 3 h, after which they were either killed or infused with insulin at a rate of 0.5 U/kg per h for 5 min, before RQ collection. Plasma FFAs were elevated to ∼2 mM in the LIP rats only. Insulin-stimulated insulin receptor (IR) Tyr1162/Tyr1163 phosphorylation and IR substrate (IRS)-1 Tyr612 phosphorylation were increased at least twofold over basal in GLYC rats with insulin and this increase was not significantly impaired in the LIP rats. However, there was no insulin-stimulated protein kinase B (PKB) Ser473 or glycogen synthase kinase (GSK)-3β Ser9 phosphorylation in the LIP rats, compared with at least a twofold increase over basal in GLYC rats for both proteins. c-Jun N-terminal kinase, inhibitor of κ kinase β and inhibitor of nuclear factor-κB phosphorylation and total protein expression, as well as Ser307-IRS-1 phosphorylation, were not altered by lipid infusion compared with GLYC infusion. These data indicate that acute, physiological elevation in FFA has a greater impact on insulin signalling downstream of IR and IRS-1, at the level of PKB and GSK-3β, and that under these conditions stress signalling pathways are not significantly stimulated. Decreased PKB and GSK-3β phosphorylation in RQ may therefore be primary determinants of the reduced insulin action observed in situations of acute FFA oversupply.

Insulin promotes glycogen synthesis in the absence of GSK3 phosphorylation in skeletal muscle

2008 ◽  
Vol 294 (1) ◽  
pp. E28-E35 ◽  
Author(s):  
Michale Bouskila ◽  
Michael F. Hirshman ◽  
Jørgen Jensen ◽  
Laurie J. Goodyear ◽  
Kei Sakamoto
Keyword(s):  
Skeletal Muscle ◽  
Glucose Uptake ◽  
Muscle Glycogen ◽  
Glycogen Content ◽  
Glycogen Synthase ◽  
Glycogen Synthesis ◽  
Wild Type ◽  
Muscle Glycogen Synthesis ◽  
Mutant Forms

Insulin promotes dephosphorylation and activation of glycogen synthase (GS) by inactivating glycogen synthase kinase (GSK) 3 through phosphorylation. Insulin also promotes glucose uptake and glucose 6-phosphate (G-6- P) production, which allosterically activates GS. The relative importance of these two regulatory mechanisms in the activation of GS in vivo is unknown. The aim of this study was to investigate if dephosphorylation of GS mediated via GSK3 is required for normal glycogen synthesis in skeletal muscle with insulin. We employed GSK3 knockin mice in which wild-type GSK3α and -β genes are replaced with mutant forms (GSK3α/βS21A/S21A/S9A/S9A), which are nonresponsive to insulin. Although insulin failed to promote dephosphorylation and activation of GS in GSK3α/βS21A/S21A/S9A/S9Amice, glycogen content in different muscles from these mice was similar compared with wild-type mice. Basal and epinephrine-stimulated activity of muscle glycogen phosphorylase was comparable between wild-type and GSK3 knockin mice. Incubation of isolated soleus muscle in Krebs buffer containing 5.5 mM glucose in the presence or absence of insulin revealed that the levels of G-6- P, the rate of [14C]glucose incorporation into glycogen, and an increase in total glycogen content were similar between wild-type and GSK3 knockin mice. Injection of glucose containing 2-deoxy-[3H]glucose and [14C]glucose also resulted in similar rates of muscle glucose uptake and glycogen synthesis in vivo between wild-type and GSK3 knockin mice. These results suggest that insulin-mediated inhibition of GSK3 is not a rate-limiting step in muscle glycogen synthesis in mice. This suggests that allosteric regulation of GS by G-6- P may play a key role in insulin-stimulated muscle glycogen synthesis in vivo.

scholarly journals Transgenic overexpression of protein targeting to glycogen markedly increases adipocytic glycogen storage in mice

2007 ◽  
Vol 292 (3) ◽  
pp. E952-E963 ◽  
Author(s):  
Michael J. Jurczak ◽  
Arpad M. Danos ◽  
Victoria R. Rehrmann ◽  
Margaret B. Allison ◽  
Cynthia C. Greenberg ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Fatty Acid ◽  
Glycogen Synthase ◽  
Glycogen Synthesis ◽  
Transgenic Animals ◽  
Glycogen Metabolism ◽  
Glycogen Storage ◽  
Fatty Acid Binding ◽  
Fat Depots

Adipocytes express the rate-limiting enzymes required for glycogen metabolism and increase glycogen synthesis in response to insulin. However, the physiological function of adipocytic glycogen in vivo is unclear, due in part to the low absolute levels and the apparent biophysical constraints of adipocyte morphology on glycogen accumulation. To further study the regulation of glycogen metabolism in adipose tissue, transgenic mice were generated that overexpressed the protein phosphatase-1 (PP1) glycogen-targeting subunit (PTG) driven by the adipocyte fatty acid binding protein (aP2) promoter. Exogenous PTG was detected in gonadal, perirenal, and brown fat depots, but it was not detected in any other tissue examined. PTG overexpression resulted in a modest redistribution of PP1 to glycogen particles, corresponding to a threefold increase in the glycogen synthase activity ratio. Glycogen synthase protein levels were also increased twofold, resulting in a combined greater than sixfold enhancement of basal glycogen synthase specific activity. Adipocytic glycogen levels were increased 200- to 400-fold in transgenic animals, and this increase was maintained to 1 yr of age. In contrast, lipid metabolism in transgenic adipose tissue was not significantly altered, as assessed by lipogenic rates, weight gain on normal or high-fat diets, or circulating free fatty acid levels after a fast. However, circulating and adipocytic leptin levels were doubled in transgenic animals, whereas adiponectin expression was unchanged. Cumulatively, these data indicate that murine adipocytes are capable of storing far higher levels of glycogen than previously reported. Furthermore, these results were obtained by overexpression of an endogenous adipocytic protein, suggesting that mechanisms may exist in vivo to maintain adipocytic glycogen storage at a physiological set point.

scholarly journals Indirubin Analogues Inhibit Trypanosoma brucei Glycogen Synthase Kinase 3 Short and T. brucei Growth

2019 ◽  
Vol 63 (6) ◽  
Author(s):  
Antonia Efstathiou ◽  
Nicolas Gaboriaud-Kolar ◽  
Vassilios Myrianthopoulos ◽  
Konstantina Vougogiannopoulou ◽  
Ines Subota ◽  
...  
Keyword(s):  
Trypanosoma Brucei ◽  
Glycogen Synthase ◽  
Intracellular Localization ◽  
Protozoan Parasite ◽  
Glycogen Synthase Kinase ◽  
Glycogen Synthase Kinase 3 ◽  
Content Type ◽  
Antitrypanosomal Activity ◽  
Half Maximal Effective Concentration

ABSTRACT The protozoan parasite Trypanosoma brucei is the causative agent of human African trypanosomiasis (HAT). The disease is fatal if it remains untreated, whereas most drug treatments are inadequate due to high toxicity, difficulties in administration, and low central nervous system penetration. T. brucei glycogen synthase kinase 3 short (TbGSK3s) is essential for parasite survival and thus represents a potential drug target that could be exploited for HAT treatment. Indirubins, effective leishmanicidals, provide a versatile scaffold for the development of potent GSK3 inhibitors. Herein, we report on the screening of 69 indirubin analogues against T. brucei bloodstream forms. Of these, 32 compounds had potent antitrypanosomal activity (half-maximal effective concentration = 0.050 to 3.2 μM) and good selectivity for the analogues over human HepG2 cells (range, 7.4- to over 641-fold). The majority of analogues were potent inhibitors of TbGSK3s, and correlation studies for an indirubin subset, namely, the 6-bromosubstituted 3′-oxime bearing an extra bulky substituent on the 3′ oxime [(6-BIO-3′-bulky)-substituted indirubins], revealed a positive correlation between kinase inhibition and antitrypanosomal activity. Insights into this indirubin-TbGSK3s interaction were provided by structure-activity relationship studies. Comparison between 6-BIO-3′-bulky-substituted indirubin-treated parasites and parasites silenced for TbGSK3s by RNA interference suggested that the above-described compounds may target TbGSK3s in vivo. To further understand the molecular basis of the growth arrest brought about by the inhibition or ablation of TbGSK3s, we investigated the intracellular localization of TbGSK3s. TbGSK3s was present in cytoskeletal structures, including the flagellum and basal body area. Overall, these results give insights into the mode of action of 6-BIO-3′-bulky-substituted indirubins that are promising hits for antitrypanosomal drug discovery.

scholarly journals Overexpression of SH2-Containing Inositol Phosphatase 2 Results in Negative Regulation of Insulin-Induced Metabolic Actions in 3T3-L1 Adipocytes via Its 5′-Phosphatase Catalytic Activity

2001 ◽  
Vol 21 (5) ◽  
pp. 1633-1646 ◽  
Author(s):  
Tsutomu Wada ◽  
Toshiyasu Sasaoka ◽  
Makoto Funaki ◽  
Hiroyuki Hori ◽  
Shihou Murakami ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Glucose Uptake ◽  
Phosphatase Activity ◽  
Insulin Signaling ◽  
Glycogen Synthase ◽  
Glycogen Synthesis ◽  
Dominant Negative ◽  
Inositol Phosphatase

ABSTRACT Phosphatidylinositol (PI) 3-kinase plays an important role in various metabolic actions of insulin including glucose uptake and glycogen synthesis. Although PI 3-kinase primarily functions as a lipid kinase which preferentially phosphorylates the D-3 position of phospholipids, the effect of hydrolysis of the key PI 3-kinase product PI 3,4,5-triphosphate [PI(3,4,5)P3] on these biological responses is unknown. We recently cloned rat SH2-containing inositol phosphatase 2 (SHIP2) cDNA which possesses the 5′-phosphatase activity to hydrolyze PI(3,4,5)P3 to PI 3,4-bisphosphate [PI(3,4)P2] and which is mainly expressed in the target tissues of insulin. To study the role of SHIP2 in insulin signaling, wild-type SHIP2 (WT-SHIP2) and 5′-phosphatase-defective SHIP2 (ΔIP-SHIP2) were overexpressed in 3T3-L1 adipocytes by means of adenovirus-mediated gene transfer. Early events of insulin signaling including insulin-induced tyrosine phosphorylation of the insulin receptor β subunit and IRS-1, IRS-1 association with the p85 subunit, and PI 3-kinase activity were not affected by expression of either WT-SHIP2 or ΔIP-SHIP2. Because WT-SHIP2 possesses the 5′-phosphatase catalytic region, its overexpression marked by decreased insulin-induced PI(3,4,5)P3 production, as expected. In contrast, the amount of PI(3,4,5)P3 was increased by the expression of ΔIP-SHIP2, indicating that ΔIP-SHIP2 functions in a dominant-negative manner in 3T3-L1 adipocytes. Both PI(3,4,5)P3 and PI(3,4)P2 were known to possibly activate downstream targets Akt and protein kinase Cλ in vitro. Importantly, expression of WT-SHIP2 inhibited insulin-induced activation of Akt and protein kinase Cλ, whereas these activations were increased by expression of ΔIP-SHIP2 in vivo. Consistent with the regulation of downstream molecules of PI 3-kinase, insulin-induced 2-deoxyglucose uptake and Glut4 translocation were decreased by expression of WT-SHIP2 and increased by expression of ΔIP-SHIP2. In addition, insulin-induced phosphorylation of GSK-3β and activation of PP1 followed by activation of glycogen synthase and glycogen synthesis were decreased by expression of WT-SHIP2 and increased by the expression of ΔIP-SHIP2. These results indicate that SHIP2 negatively regulates metabolic signaling of insulin via the 5′-phosphatase activity and that PI(3,4,5)P3 rather than PI(3,4)P2 is important for in vivo regulation of insulin-induced activation of downstream molecules of PI 3-kinase leading to glucose uptake and glycogen synthesis.

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