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Inhibiting glycogen synthase kinase 3 (GSK3) improves muscle function, metabolism, and bone health in many diseases and conditions; however, whether GSK3 should be targeted for Duchenne muscular dystrophy (DMD), a severe muscle wasting disorder with no cure, remains unknown. Here, we show the effects of GSK3 inhibition in male DBA/2J (D2) and C57BL/10 (C57) mdx mice. Treating D2 mdx mice with GSK3 inhibitors alone or in combination with aerobic exercise improves muscle strength, endurance, and morphology, attenuates the hypermetabolic phenotype, and enhances insulin sensitivity. GSK3 inhibition in C57 mdx mice also improves muscle fatigue resistance and increases cage ambulation. Moreover, muscle-specific GSK3 knockdown in mdx mice augments muscle force production and endurance. In both mdx strains, GSK3 inhibition increases bone mineral content and density. Overall, these improvements to muscle, metabolic, and bone health with GSK3 inhibition in mdx mice may have clinical implications for patients with DMD, where the current standard of care, glucocorticoids, delay the loss of ambulation but increase the risk for insulin resistance and osteoporosis. Along with our observation of lowered β-catenin content in DMD myoblasts, a known cellular target for GSK3, this study provides ample evidence in support of inhibiting GSK3 for this disease., Competing Interests: Competing interests: The authors declare the following competing interests. A portion of this project, specifically the aged (28–30 weeks) tideglusib experiments, was funded by AMO-Pharma in partnership with a Brock-Niagara Validation Prototyping and Manufacturing Applied Project Grant (1:2 monetary ratio). AMO-Pharma also provided the tideglusib for the aged tideglusib experiments. For all other experiments, tideglusib was purchased from Sigma Alrdich (SML0339)., (© 2024. The Author(s).)

Significance: Elraglusib was designed as a GSK3 inhibitor and is currently in clinical trials for several cancers. We show conclusively that the target of elraglusib that leads to cytotoxicity is MTs and not GSK3. This has significant implications for ongoing clinical trials of the compound and will help in understanding off-target side effects, inform future clinical trial design, and facilitate the development of biomarkers to predict response., (©2024 The Authors; Published by the American Association for Cancer Research.)

The molecular mechanisms by which cardiovascular risk factors promote the development of atherosclerosis are poorly understood. We have recently shown that genetic ablation of myeloid glycogen synthase kinase (GSK)-3α attenuates atherosclerotic lesion development in low-density lipoprotein receptor-deficient (Ldlr -/- ) mice. However, the precise contributions of GSK3α/β in atherogenesis are not known. The aim of this study is to investigate the effect of GSK3α and/or β deficiency on lesional inflammation and plaque vascularization. Five-week-old female Ldlr -/- mice were fed a high-fat diet for 10 weeks to establish atherosclerotic lesions. Mice were harvested at 15 weeks of age and atherosclerotic lesions were characterized. The results indicate that, in addition to significantly reducing plaque volume, GSK3α-deficiency decreases inflammation, reduces vasa vasorum density at the aortic sinus, and reduces plasma c-reactive protein (CRP) levels. GSK3β-deficiency is associated with decreased plasma CRP levels but does not affect lesional inflammation or vascularization. These results suggest GSK3α may be an applicable target for the development of novel anti-atherogenic therapies.

ER-mitochondria contact sites (ERMCSs) regulate processes, including calcium homoeostasis, energy metabolism and autophagy. Previously, it was shown that during growth factor signalling, mTORC2/Akt gets recruited to and stabilizes ERMCSs. Independent studies showed that GSK3β, a well-known Akt substrate, reduces ER-mitochondria connectivity by disrupting the VAPB-PTPIP51 tethering complex. However, the mechanisms that regulate ERMCSs are incompletely understood. Here we find that annulate lamellae (AL), relatively unexplored subdomains of ER enriched with a subset of nucleoporins, are present at ERMCSs. Depletion of Nup358, an AL-resident nucleoporin, results in enhanced mTORC2/Akt activation, GSK3β inhibition and increased ERMCSs. Depletion of Rictor, a mTORC2-specific subunit, or exogenous expression of GSK3β, was sufficient to reverse the ERMCS-phenotype in Nup358-deficient cells. We show that growth factor-mediated activation of mTORC2 requires the VAPB-PTPIP51 complex, whereas, Nup358's association with this tether restricts mTORC2/Akt signalling and ER-mitochondria connectivity. Expression of a Nup358 fragment that is sufficient for interaction with the VAPB-PTPIP51 complex suppresses mTORC2/Akt activation and disrupts ERMCSs. Collectively, our study uncovers a novel role for Nup358 in controlling ERMCSs by modulating the mTORC2/Akt/GSK3β axis., (© 2024. The Author(s).)

The sensory cells that transduce the signals for hearing and balance are highly specialized mechanoreceptors called hair cells that together with supporting cells comprise the sensory epithelia of the inner ear. Loss of hair cells from toxin exposure and age can cause balance disorders and is essentially irreversible due to the inability of mammalian vestibular organs to regenerate physiologically active hair cells. Here, we show substantial regeneration of hair cells in a mouse model of vestibular damage by treatment with a combination of glycogen synthase kinase 3β and histone deacetylase inhibitors. The drugs stimulated supporting cell proliferation and differentiation into hair cells. The new hair cells were reinnervated by vestibular afferent neurons, rescuing otolith function by restoring head translation-evoked otolith afferent responses and vestibuloocular reflexes. Drugs that regenerate hair cells thus represent a potential therapeutic approach to the treatment of balance disorders.

Background: The established association between Alzheimer's disease (AD) and compromised neural regeneration is well-documented. In addition to the mitigation of apoptosis in neural stem cells (NSCs), the induction of neurogenesis has been proposed as a promising therapeutic strategy for AD. Our previous research has demonstrated the effective inhibition of NSC injury induced by microglial activation through the repression of oxidative stress and mitochondrial dysfunction by Sirtuin 3 (SIRT3). Nonetheless, the precise role of SIRT3 in neurogenesis remains incompletely understood., Methods: In vivo, SIRT3 overexpression adenovirus was firstly injected by brain stereotaxic localization to affect the hippocampal SIRT3 expression in APP/PS1 mice, and then behavioral experiments were performed to investigate the cognitive improvement of SIRT3 in APP/PS1 mice, as well as neurogenic changes in hippocampal region by immunohistochemistry and immunofluorescence. In vitro, under the transwell co-culture condition of microglia and neural stem cells, the mechanism of SIRT3 improving neurogenesis of neural stem cells through DVL/GSK3/ISL1 axis was investigated by immunoblotting, immunofluorescence and other experimental methods., Results: Our findings indicate that the overexpression of SIRT3 in APP/PS1 mice led to enhanced cognitive function and increased neurogenesis. Additionally, SIRT3 was observed to promote the differentiation of NSCs into neurons during retinoic acid (RA)-induced NSC differentiation in vitro, suggesting a potential role in neurogenesis. Furthermore, we observed the activation of the Wnt/ß-catenin signaling pathway during this process, with Glycogen Synthase Kinase-3a (GSK3a) primarily governing NSC proliferation and GSK3ß predominantly regulating NSC differentiation. Moreover, the outcomes of our study demonstrate that SIRT3 exerts a protective effect against microglia-induced apoptosis in neural stem cells through its interaction with DVLs., Conclusions: Our results show that SIRT3 overexpressing APP/PS1 mice have improved cognition and neurogenesis, as well as improved neurogenesis of NSC in microglia and NSC transwell co-culture conditions through the DVL/GSK3/ISL1 axis., (© 2024. The Author(s).)

5-Fluorouracil (5-FU) is widely used in the treatment of gastric cancer, and the emergence of drug resistance and toxic effects has limited its application. Therefore, there is an urgent need for safe and effective novel drugs or new therapies. β-Ionone (BI) is found in vegetables and fruits and possesses an inhibitory proliferation of tumor cells in vitro and in vivo. In this study, we investigated whether BI could enhance the inhibitory effects of 5-FU on the proliferation of gastric adenocarcinoma cells and the growth of gastric cancer cell xenografts in a mouse model. The effects of BI and 5-FU alone or their combination on the cell viability, apoptosis, and mitochondrial membrane potential, the cell cycle, and its related proteins-Cyclin D1, and CDK4 as well as PCNA and GSK-3β were evaluated in SGC-7901 cells and MKN45 cells by MTT, MB, flow cytometry and Western blot. In addition, the effects of BI and 5-FU alone or their combination on the growth of SGC-7901 cell xenografts in nude mice were investigated. The results showed that BI significantly enhanced the sensitivity of gastric adenocarcinoma cells to 5-FU in vitro and in vivo, i.e. proliferation inhibited, apoptosis induced and GSK-3β protein activated. Therefore, our results suggest that BI increases the antitumor effect of 5-FU on gastric adenocarcinoma cells, at least partly from an activated GSK-3β signaling pathway., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Wang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Centromeric localization of evolutionarily conserved CENP-A (Cse4 in Saccharomyces cerevisiae) is essential for chromosomal stability. Mislocalization of overexpressed CENP-A to noncentromeric regions contributes to chromosomal instability in yeasts, flies, and humans. Overexpression and mislocalization of CENP-A observed in many cancers are associated with poor prognosis. Previous studies have shown that F-box proteins, Cdc4 and Met30 of the Skp, Cullin, F-box ubiquitin ligase cooperatively regulate proteolysis of Cse4 to prevent Cse4 mislocalization and chromosomal instability under normal physiological conditions. Mck1-mediated phosphorylation of Skp, Cullin, F-box-Cdc4 substrates such as Cdc6 and Rcn1 enhances the interaction of the substrates with Cdc4. Here, we report that Mck1 interacts with Cse4, and Mck1-mediated proteolysis of Cse4 prevents Cse4 mislocalization for chromosomal stability. Our results showed that mck1Δ strain overexpressing CSE4 (GAL-CSE4) exhibits lethality, defects in ubiquitin-mediated proteolysis of Cse4, mislocalization of Cse4, and reduced Cse4-Cdc4 interaction. Strain expressing GAL-cse4-3A with mutations in three potential Mck1 phosphorylation consensus sites (S10, S16, and T166) also exhibits growth defects, increased stability with mislocalization of Cse4-3A, chromosomal instability, and reduced interaction with Cdc4. Constitutive expression of histone H3 (Δ16H3) suppresses the chromosomal instability phenotype of GAL-cse4-3A strain, suggesting that the chromosomal instability phenotype is linked to Cse4-3A mislocalization. We conclude that Mck1 and its three potential phosphorylation sites on Cse4 promote Cse4-Cdc4 interaction and this contributes to ubiquitin-mediated proteolysis of Cse4 preventing its mislocalization and chromosomal instability. These studies advance our understanding of pathways that regulate cellular levels of CENP-A to prevent mislocalization of CENP-A in human cancers., Competing Interests: Conflicts of interest: The authors declare no conflict of interest., (Published by Oxford University Press on behalf of The Genetics Society of America 2024.)

Brain protein aggregates are a hallmark of neurodegenerative disease. Previous work indicates that specific protein components of these aggregates are toxic, including tau (encoded by MAPT) in Alzheimer's disease and related tauopathies. Increasing evidence also indicates that these toxic proteins traffic between cells in a prion-like fashion, thereby spreading pathology from one brain region to another. However, the mechanisms involved in trafficking are poorly understood. We therefore developed a transgenic Drosophila model to facilitate rapid evaluation of candidate tau trafficking modifiers. Our model uses the bipartite Q system to drive co-expression of tau and GFP in the fly eye. We found age-dependent spread of tau into the brain, represented by detection of tau, but not of GFP. We also found that tau trafficking was attenuated upon inhibition of the endocytic factor dynamin (encoded by shi) or knockdown of glycogen synthase kinase-3β (GSK-3β, encoded by sgg). Further work revealed that dynamin promoted tau uptake in recipient tissues, whereas GSK-3β appeared to promote tau spread via direct phosphorylation of tau. Our robust and flexible system will promote the identification of tau-trafficking components involved in the pathogenesis of neurodegenerative diseases., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2024. Published by The Company of Biologists Ltd.)

CTNNB1 syndrome is a rare monogenetic disorder caused by CTNNB1 de novo pathogenic heterozygous loss-of-function variants that result in cognitive and motor disabilities. Treatment is currently lacking; our study addresses this critical need. CTNNB1 encodes β-catenin which is essential for normal brain function via its dual roles in cadherin-based synaptic adhesion complexes and canonical Wnt signal transduction. We have generated a Ctnnb1 germline heterozygous mouse line that displays cognitive and motor deficits, resembling key features of CTNNB1 syndrome in humans. Compared with wild-type littermates, Ctnnb1 heterozygous mice also exhibit decreases in brain β-catenin, β-catenin association with N-cadherin, Wnt target gene expression, and Na/K ATPases, key regulators of changes in ion gradients during high activity. Consistently, hippocampal neuron functional properties and excitability are altered. Most important, we identify a highly selective inhibitor of glycogen synthase kinase (GSK)3α,β that significantly normalizes the phenotypes to closely meet wild-type littermate levels. Our data provide new insights into brain molecular and functional changes, and the first evidence for an efficacious treatment with therapeutic potential for individuals with CTNNB1 syndrome., (© 2024. The Author(s).)

Background: Immune escape is an important feature of hepatocellular carcinoma (HCC). The overall response rate of immune checkpoint inhibitors (ICIs) in HCC is still limited. Revealing the immune regulation mechanisms and finding new immune targets are expected to further improve the efficacy of immunotherapy. Our study aims to use CRISPR screening mice models to identify potential targets that play a critical role in HCC immune evasion and further explore their value in improving immunotherapy., Methods: We performed CRISPR screening in two mice models with different immune backgrounds (C57BL/6 and NPG mice) and identified the immunosuppressive gene Gsk3a as a candidate for further investigation. Flow cytometry was used to analyze the impact of Gsk3a on immune cell infiltration and T-cell function. RNA sequencing was used to identify the changes in neutrophil gene expression induced by Gsk3a and alterations in downstream molecules. The therapeutic value of the combination of Gsk3a inhibitors and anti-programmed cell death protein-1 (PD-1) antibody was also explored., Results: Gsk3a , as an immune inhibitory target, significantly promoted tumor growth in immunocompetent mice rather than immune-deficient mice. Gsk3a inhibited cytotoxic T lymphocytes (CTLs) function by inducing neutrophil chemotaxis. Gsk3a promoted self-chemotaxis of neutrophil expression profiles and neutrophil extracellular traps (NETs) formation to block T-cell activity through leucine-rich α-2-glycoprotein 1 (LRG1). A significant synergistic effect was observed when Gsk3a inhibitor was in combination with anti-PD-1 antibody., Conclusions: We identified a potential HCC immune evasion target, Gsk3a , through CRISPR screening. Gsk3a induces neutrophil recruitment and NETs formation through the intermediate molecule LRG1, leading to the inhibition of CTLs function. Targeting Gsk3a can enhance CTLs function and improve the efficacy of ICIs., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Malattia Leventinese/Doyne honeycomb retinal dystrophy (ML/DHRD) is an age-related macular degeneration-like (AMD-like) retinal dystrophy caused by an autosomal dominant R345W mutation in the secreted glycoprotein, fibulin-3 (F3). To identify new small molecules that reduce F3 production in retinal pigmented epithelium (RPE) cells, we knocked-in a luminescent peptide tag (HiBiT) into the endogenous F3 locus that enabled simple, sensitive, and high-throughput detection of the protein. The GSK3 inhibitor, CHIR99021 (CHIR), significantly reduced F3 burden (expression, secretion, and intracellular levels) in immortalized RPE and non-RPE cells. Low-level, long-term CHIR treatment promoted remodeling of the RPE extracellular matrix, reducing sub-RPE deposit-associated proteins (e.g., amelotin, complement component 3, collagen IV, and fibronectin), while increasing RPE differentiation factors (e.g., tyrosinase, and pigment epithelium-derived factor). In vivo, treatment of 8-month-old R345W+/+ knockin mice with CHIR (25 mg/kg i.p., 1 mo) was well tolerated and significantly reduced R345W F3-associated AMD-like basal laminar deposit number and size, thereby preventing the main pathological feature in these mice. This is an important demonstration of small molecule-based prevention of AMD-like pathology in ML/DHRD mice and may herald a rejuvenation of interest in GSK3 inhibition for the treatment of retinal degenerative diseases, including potentially AMD itself.

Nowadays, GSK3 is accepted as an enzyme strongly involved in the regulation of inflammation by balancing the pro- and anti-inflammatory responses of cells and organisms, thus influencing the initiation, progression, and resolution of inflammatory processes at multiple levels. Disturbances within its broad functional scope, either intrinsically or extrinsically induced, harbor the risk of profound disruptions to the regular course of the immune response, including the formation of severe inflammation-related diseases. Therefore, this review aims at summarizing and contextualizing the current knowledge derived from animal models to further shape our understanding of GSK3α and β and their roles in the inflammatory process and the occurrence of tissue/organ damage. Following a short recapitulation of structure, function, and regulation of GSK3, we will focus on the lessons learned from GSK3α/β knock-out and knock-in/overexpression models, both conventional and conditional, as well as a variety of (predominantly rodent) disease models reflecting defined pathologic conditions with a significant proportion of inflammation and inflammation-related tissue injury. In summary, the literature suggests that GSK3 acts as a crucial switch driving pro-inflammatory and destructive processes and thus contributes significantly to the pathogenesis of inflammation-associated diseases.

The signaling complex around voltage-gated sodium (Nav) channels includes accessory proteins and kinases crucial for regulating neuronal firing. Previous studies showed that one such kinase, WEE1-critical to the cell cycle-selectively modulates Nav1.2 channel activity through the accessory protein fibroblast growth factor 14 (FGF14). Here, we tested whether WEE1 exhibits crosstalk with the AKT/GSK3 kinase pathway for coordinated regulation of FGF14/Nav1.2 channel complex assembly and function. Using the in-cell split luciferase complementation assay (LCA), we found that the WEE1 inhibitor II and GSK3 inhibitor XIII reduce the FGF14/Nav1.2 complex formation, while the AKT inhibitor triciribine increases it. However, combining WEE1 inhibitor II with either one of the other two inhibitors abolished its effect on the FGF14/Nav1.2 complex formation. Whole-cell voltage-clamp recordings of sodium currents (I Na ) in HEK293 cells co-expressing Nav1.2 channels and FGF14-GFP showed that WEE1 inhibitor II significantly suppresses peak I Na density, both alone and in the presence of triciribine or GSK3 inhibitor XIII, despite the latter inhibitor's opposite effects on I Na . Additionally, WEE1 inhibitor II slowed the tau of fast inactivation and caused depolarizing shifts in the voltage dependence of activation and inactivation. These phenotypes either prevailed or were additive when combined with triciribine but were outcompeted when both WEE1 inhibitor II and GSK3 inhibitor XIII were present. Concerted regulation by WEE1 inhibitor II, triciribine, and GSK3 inhibitor XIII was also observed in long-term inactivation and use dependency of Nav1.2 currents. Overall, these findings suggest a complex role for WEE1 kinase-in concert with the AKT/GSK3 pathway-in regulating the Nav1.2 channelosome.

Background: Physical exercise has been shown to be beneficial for individuals with Alzheimer's disease (AD), although the underlying mechanisms are not fully understood., Methods: Six-month-old Amyloid precursor protein/Presenilin 1 (APP/PS1) transgenic (Tg) mice and wild-type (Wt) mice were randomly assigned to either a sedentary group (Tg-Sed, Wt-Sed) or an exercise group (Tg-Ex, Wt-Ex) undertaking a 12-week, moderate-intensity treadmill running program. Consequently, all mice were tested for memory function and amyloid β (Aβ) levels and phosphorylation of tau and protein kinase B (Akt)/glycogen synthase kinase-3 (GSK3) were examined in tissues of both the cortex and hippocampus., Results: Tg-Sed mice had severely impaired memory, higher levels of Aβ, and increased phosphorylation of tau, GSK3α tyrosine279, and GSK3β tyrosine216, but less phosphorylation of GSK3α serine21, GSK3β serine9, and Akt serine473 in both tissues than Wt-Sed mice in respective tissues. Tg-Ex mice showed significant improvement in memory function along with lower levels of Aβ and less phosphorylation of tau (both tissues), GSK3α tyrosine279 (both tissues), and GSK3β tyrosine216 (hippocampus only), but increased phosphorylation of GSK3α serine21 (both tissues), GSK3β serine9 (hippocampus only), and Akt serine473 (both tissues) compared with Tg-Sed mice in respective tissues., Conclusions: Moderate-intensity aerobic exercise is highly effective in improving memory function in 9-month-old APP/PS1 mice, most likely through differential modulation of GSK3α/β phosphorylation in the cortex and hippocampus., Competing Interests: The authors declare no conflict of interest., (© 2024 The Author(s). Published by IMR Press.)

Non-invasive imaging of GSK-3 expression in the brain will help to understand the role of GSK-3 in disease pathology and progression. Herein, we report the radiosynthesis and evaluation of two novel isonicotinamide based 18 F labeled PET probes, [ 18 F]2 and [ 18 F]6 for noninvasive imaging of GSK3. Among the developed PET probes, the in vitro blood-brain permeability coefficient of 2 (38 ± 20 × 10 -6  cm/s, n = 3) was found to be better than 6 (8.75 ± 3.90 × 10 -6  cm/s, n = 5). The reference compounds 2 and 6 showed nanomolar affinity towards GSK-3α and GSK-3β. PET probe [ 18 F]2 showed higher stability (100%) in mouse and human serums compared to [ 18 F]6 (67.01 ± 4.93%, n = 3) in mouse serum and 66.20 ± 6.38%, n = 3) in human serum at 120 min post incubation. The in vivo imaging and blocking studies were performed in wild-type mice only with [ 18 F]2 due to its observed stability. [ 18 F]2 showed a SUV of 0.92 ± 0.28 (n = 6) in mice brain as early as 5 min post-injection followed by gradual clearance over time., (© 2024. The Author(s).)

Glycogen synthase kinase-3 (GSK3), consisting of GSK3α and GSK3β subtypes, is a complex protein kinase that regulates numerous substrates. Research has observed increased GSK3 expression in the brains of Alzheimer's disease (AD) patients and models. AD is a neurodegenerative disorder with diverse pathogenesis and notable cognitive impairments, characterized by Aβ aggregation and excessive tau phosphorylation. This article provides an overview of GSK3's structure and regulation, extensively analyzing its relationship with AD factors. GSK3 overactivation disrupts neural growth, development, and function. It directly promotes tau phosphorylation, regulates amyloid precursor protein (APP) cleavage, leading to Aβ formation, and directly or indirectly triggers neuroinflammation and oxidative damage. We also summarize preclinical research highlighting the inhibition of GSK3 activity as a primary therapeutic approach for AD. Finally, pending issues like the lack of highly specific and affinity-driven GSK3 inhibitors, are raised and expected to be addressed in future research. In conclusion, GSK3 represents a target in AD treatment, filled with hope, challenges, opportunities, and obstacles., (© 2024 The Author(s). CNS Neuroscience & Therapeutics published by John Wiley & Sons Ltd.)

Members of the casein kinase 1 (CK1) family are important regulators of multiple signaling pathways. CK1α is a well-known negative regulator of the Wnt/β-catenin pathway, which promotes the degradation of β-catenin via its phosphorylation of Ser45. In contrast, the closest paralog of CK1α, CK1α-like, is a poorly characterized kinase of unknown function. In this study, we show that the deletion of CK1α, but not CK1α-like, resulted in a strong activation of the Wnt/β-catenin pathway. Wnt-3a treatment further enhanced the activation, which suggests there are at least two modes, a CK1α-dependent and Wnt-dependent, of β-catenin regulation. Rescue experiments showed that only two out of ten naturally occurring splice CK1α/α-like variants were able to rescue the augmented Wnt/β-catenin signaling caused by CK1α deficiency in cells. Importantly, the ability to phosphorylate β-catenin on Ser45 in the in vitro kinase assay was required but not sufficient for such rescue. Our compound CK1α and GSK3α/β KO models suggest that the additional nonredundant function of CK1α in the Wnt pathway beyond Ser45-β-catenin phosphorylation includes Axin phosphorylation. Finally, we established NanoBRET assays for the three most common CK1α splice variants as well as CK1α-like. Target engagement data revealed comparable potency of known CK1α inhibitors for all CK1α variants but not for CK1α-like. In summary, our work brings important novel insights into the biology of CK1α, including evidence for the lack of redundancy with other CK1 kinases in the negative regulation of the Wnt/β-catenin pathway at the level of β-catenin and Axin., Competing Interests: Conflict of interest B.-T. B. is the CEO and a shareholder of CELLinib GmbH, Frankfurt, Germany. All other authors declare that they have no conflicts of interests with the contents of this article., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The amount of dietary sugars and the administration of lithium both impact the lifespan of the fruit fly Drosophila melanogaster . It is noteworthy that lithium is attributed with insulin-like activity as it stimulates protein kinase B/Akt and suppresses the activity of glycogen synthase kinase-3 (GSK-3). However, its interaction with dietary sugar has largely remained unexplored. Therefore, we investigated the effects of lithium supplementation on known lithium-sensitive parameters in fruit flies, such as lifespan, body composition, GSK-3 phosphorylation, and the transcriptome, while varying the dietary sugar concentration. For all these parameters, we observed that the efficacy of lithium was significantly influenced by the sucrose content in the diet. Overall, we found that lithium was most effective in enhancing longevity and altering body composition when added to a low-sucrose diet. Whole-body RNA sequencing revealed a remarkably similar transcriptional response when either increasing dietary sucrose from 1% to 10% or adding 1 mM LiCl to a 1% sucrose diet, characterized by a substantial overlap of nearly 500 differentially expressed genes. Hence, dietary sugar supply is suggested as a key factor in understanding lithium bioactivity, which could hold relevance for its therapeutic applications.

Epithelial ovarian cancer (EOC) is one of the most common malignant gynecological tumors with rapid growth potential and poor prognosis, however, the molecular mechanism underlying its outgrowth remained elusive. Germ cell-specific gene 2 (GSG2) was previously reported to be highly expressed in ovarian cancer and was essential for the growth of EOC. In this study, GSG2-knockdown cells and GSG2-overexpress cells were established through lentivirus-mediated transfection with Human ovarian cancer cells HO8910 and SKOV3. Knockdown of GSG2 inhibited cell proliferation and induced G2/M phase arrest in EOC. Interestingly, the expression of p27, a well-known regulator of the cell cycle showed a most significant increase after GSG2 knockdown. Further phosphorylation-protein array demonstrated the phosphorylation of GSK3αSer21 decreased in GSG2-knockdown cells to the most extent. Notably, inhibiting GSK3α activity effectively rescued GSG2 knockdown's suppression on cell cycle as well as p27 expression in EOC. Our study substantiates that GSG2 is able to phosphorylate GSK3α at Ser21 and then leads to the reduction of p27 expression, resulting in cell cycle acceleration and cell proliferation promotion. Thus, GSG2 may have the potential to become a promising target in EOC., (© 2024. The Author(s).)

Seminal roots play a critical role in water and nutrient absorption, particularly in the early developmental stages of wheat. However, the genes responsible for controlling SRN in wheat remain largely unknown. Genetic mapping and functional analyses identified a candidate gene (TraesCS3D01G137200, TaSRN-3D) encoding a Ser/Thr kinase glycogen synthase kinase 3 (STKc_GSK3) that regulated SRN in wheat. Additionally, experiments involving hormone treatment, nitrate absorption and protein interaction were conducted to explore the regulatory mechanism of TaSRN-3D. Results showed that the TaSRN-3D 4332 allele inhibited seminal roots initiation and development, while loss-of-function mutants showed significantly higher seminal root number (SRN). Exogenous application of epi-brassinolide could increase the SRN in a HS2-allelic background. Furthermore, chlorate sensitivity and 15 N uptake assays revealed that a higher number of seminal roots promoted nitrate accumulation. TaBSR1 (BIN2-related SRN Regulator 1, orthologous to OsGRF4/GL2 in rice) acts as an interactor of TaSRN-3D and promotes TaBSR1 degradation to reduce SRN. This study provides valuable insights into understanding the genetic basis and regulatory network of SRN in wheat, highlighting their roles as potential targets for root-based improvement in wheat breeding., (© 2024 The Authors New Phytologist © 2024 New Phytologist Foundation.)

Plants often adapt to adverse or stress conditions via differential growth. The trans-Golgi network (TGN) has been implicated in stress responses, but it is not clear in what capacity it mediates adaptive growth decisions. In this study, we assess the role of the TGN in stress responses by exploring the previously identified interactome of the Transport Protein Particle II (TRAPPII) complex required for TGN structure and function. We identified physical and genetic interactions between AtTRAPPII and shaggy-like kinases (GSK3/AtSKs) and provided in vitro and in vivo evidence that the TRAPPII phosphostatus mediates adaptive responses to abiotic cues. AtSKs are multifunctional kinases that integrate a broad range of signals. Similarly, the AtTRAPPII interactome is vast and considerably enriched in signaling components. An AtSK-TRAPPII interaction would integrate all levels of cellular organization and instruct the TGN, a central and highly discriminate cellular hub, as to how to mobilize and allocate resources to optimize growth and survival under limiting or adverse conditions., (© 2024 Wiese et al.)

Accumulation of reactive oxygen species (i.e., oxidative stress) is a leading cause of beta cell dysfunction and apoptosis in diabetes. NRF2 (NF-E2 p45-related factor-2) regulates the adaptation to oxidative stress, and its activity is negatively regulated by the redox-sensitive CUL3 (cullin-3) ubiquitin ligase substrate adaptor KEAP1 (Kelch-like ECH-associated protein-1). Additionally, NRF2 is repressed by the insulin-regulated Glycogen Synthase Kinase-3 (GSK3). We have demonstrated that phosphorylation of NRF2 by GSK3 enhances β-TrCP (beta-transducin repeat-containing protein) binding and ubiquitylation by CUL1 (cullin-1), resulting in increased proteasomal degradation of NRF2. Thus, we hypothesise that inhibition of GSK3 activity or β-TrCP binding upregulates NRF2 and so protects beta cells against oxidative stress. We have found that treating the pancreatic beta cell line INS-1 832/13 with the KEAP1 inhibitor TBE31 significantly enhanced NRF2 protein levels. The presence of the GSK3 inhibitor CT99021 or the β-TrCP-NRF2 protein-protein interaction inhibitor PHAR, along with TBE31, resulted in prolonged NRF2 stability and enhanced nuclear localisation (P < 0.05). TBE31-mediated induction of NRF2-target genes encoding NAD(P)H quinone oxidoreductase 1 (Nqo1), glutamate-cysteine ligase modifier (Gclm) subunit and heme oxygenase (Hmox1) was significantly enhanced by the presence of CT99021 or PHAR (P < 0.05) in both INS-1 832/13 and in isolated mouse islets. Identical results were obtained using structurally distinct GSK3 inhibitors and inhibition of KEAP1 with sulforaphane. In summary, we demonstrate that GSK3 and β-TrCP/CUL1 regulate the proteasomal degradation of NRF2, enhancing the impact of KEAP1 regulation, and so contributes to the redox status of pancreatic beta cells. Inhibition of GSK3, or β-TrCP/CUL1 binding to NRF2 may represent a strategy to protect beta cells from oxidative stress., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Hypertension is a pervasive and widespread health condition that poses a significant risk factor for cardiovascular disease, which includes conditions such as heart attack, stroke, and heart failure. Despite its widespread occurrence, the exact cause of hypertension remains unknown, and the mechanisms underlying the progression from prehypertension to hypertension require further investigation. Recent proteomic studies have shown promising results in uncovering potential biomarkers related to disease development. In this study, serum proteomic data collected from Qatar Biobank were analyzed to identify altered protein expression between individuals with normal blood pressure, prehypertension, and hypertension and to elucidate the biological pathways contributing to this disease. The results revealed a cluster of proteins, including the SRC family, CAMK2B, CAMK2D, TEC, GSK3, VAV, and RAC, which were markedly upregulated in patients with hypertension compared to those with prehypertension (fold change ≥ 1.6 or ≤-1.6, area under the curve ≥ 0.8, and q -value < 0.05). Pathway analysis showed that the majority of these proteins play a role in actin cytoskeleton remodeling. Actin cytoskeleton reorganization affects various biological processes that contribute to the maintenance of blood pressure, including vascular tone, endothelial function, cellular signaling, inflammation, fibrosis, and mechanosensing. Therefore, the findings of this study suggest a potential novel role of actin cytoskeleton-related proteins in the progression from prehypertension to hypertension. The present study sheds light on the underlying pathological mechanisms involved in hypertension and could pave the way for new diagnostic and therapeutic approaches for the treatment of this disease.

Astrocytes and ependymal cells have been reported to be able to switch from a mature cell identity towards that of a neural stem/progenitor cell. Astrocytes are widely scattered in the brain where they exert multiple functions and are routinely targeted for in vitro and in vivo reprogramming. Ependymal cells serve more specialized functions, lining the ventricles and the central canal, and are multiciliated, epithelial-like cells that, in the spinal cord, act as bi-potent progenitors in response to injury. Here, we isolate or generate ependymal cells and post-mitotic astrocytes, respectively, from the lateral ventricles of the mouse brain and we investigate their capacity to reverse towards a progenitor-like identity in culture. Inhibition of the GSK3 and TGFβ pathways facilitates the switch of mature astrocytes to Sox2-expressing, mitotic cells that generate oligodendrocytes. Although this medium allows for the expansion of quiescent NSCs, isolated from live rats by "milking of the brain", it does not fully reverse astrocytes towards the bona fide NSC identity; this is a failure correlated with a concomitant lack of neurogenic activity. Ependymal cells could be induced to enter mitosis either via exposure to neuraminidase-dependent stress or by culturing them in the presence of FGF2 and EGF. Overall, our data confirm that astrocytes and ependymal cells retain a high capacity to reverse to a progenitor identity and set up a simple and highly controlled platform for the elucidation of the molecular mechanisms that regulate this reversal.

Glycogen synthase kinase 3 (GSK3) signaling plays important and broad roles in regulating neural development in vitro and in vivo. Here, we reviewed recent findings of GSK3-regulated axon regeneration in vivo in both the peripheral and central nervous systems and discussed a few controversial findings in the field. Overall, current evidence indicates that GSK3β signaling serves as an important downstream mediator of the PI3K-AKT pathway to regulate axon regeneration in parallel with the mTORC1 pathway. Specifically, the mTORC1 pathway supports axon regeneration mainly through its role in regulating cap-dependent protein translation, whereas GSK3β signaling might be involved in regulating N6-methyladenosine mRNA methylation-mediated, cap-independent protein translation. In addition, GSK3 signaling also plays a key role in reshaping the neuronal transcriptomic landscape during neural regeneration. Finally, we proposed some research directions to further elucidate the molecular mechanisms underlying the regulatory function of GSK3 signaling and discover novel GSK3 signaling-related therapeutic targets. Together, we hope to provide an updated and insightful overview of how GSK3 signaling regulates neural regeneration in vivo., (© The Author(s) (2023). Published by Oxford University Press on behalf of Journal of Molecular Cell Biology, CEMCS, CAS.)

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies worldwide. However, drug discovery for PDAC treatment has proven complicated, leading to stagnant therapeutic outcomes. Here, we identify Glycogen synthase kinase 3 (GSK3) as a therapeutic target through a whole-body genetic screening utilizing a '4-hit' Drosophila model mimicking the PDAC genotype. Reducing the gene dosage of GSK3 in a whole-body manner or knocking down GSK3 specifically in transformed cells suppressed 4-hit fly lethality, similar to Mitogen-activated protein kinase kinase (MEK), the therapeutic target in PDAC we have recently reported. Consistently, a combination of the GSK3 inhibitor CHIR99021 and the MEK inhibitor trametinib suppressed the phosphorylation of Polo-like kinase 1 (PLK1) as well as the growth of orthotopic human PDAC xenografts in mice. Additionally, reducing PLK1 genetically in 4-hit flies rescued their lethality. Our results reveal a therapeutic vulnerability in PDAC that offers a treatment opportunity for patients by inhibiting multiple targets., (© 2024 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

Regulation of SIRT1 activity is vital to energy homeostasis and plays important roles in many diseases. We previously showed that insulin triggers the epigenetic regulator DBC1 to prime SIRT1 for repression by the multifunctional trafficking protein PACS-2. Here, we show that liver DBC1/PACS-2 regulates the diurnal inhibition of SIRT1, which is critically important for insulin-dependent switch in fuel metabolism from fat to glucose oxidation. We present the x-ray structure of the DBC1 S1-like domain that binds SIRT1 and an NMR characterization of how the SIRT1 N-terminal region engages DBC1. This interaction is inhibited by acetylation of K112 of DBC1 and stimulated by the insulin-dependent phosphorylation of human SIRT1 at S162 and S172, catalyzed sequentially by CK2 and GSK3, resulting in the PACS-2-dependent inhibition of nuclear SIRT1 enzymatic activity and translocation of the deacetylase in the cytoplasm. Finally, we discuss how defects in the DBC1/PACS-2-controlled SIRT1 inhibitory pathway are associated with disease, including obesity and non-alcoholic fatty liver disease., (© 2024 The Protein Society.)

Cohesin is a highly conserved ring-shaped complex involved in topologically embracing chromatids, gene expression regulation, genome compartmentalization, and genome stability maintenance. Genomic analyses have detected mutations in the cohesin complex in a wide array of human tumors. These findings have led to increased interest in cohesin as a potential target in cancer therapy. Synthetic lethality has been suggested as an approach to exploit genetic differences in cancer cells to influence their selective killing. In this study, we show that mutations in ESCO1 , NIPBL , PDS5B , RAD21 , SMC1A , SMC3 , STAG2 , and WAPL genes are synthetically lethal with stimulation of WNT signaling obtained following LY2090314 treatment, a GSK3 inhibitor, in several cancer cell lines. Moreover, treatment led to the stabilization of β-catenin and affected the expression of c-MYC, probably due to the occupancy decrease in cohesin at the c-MYC promoter. Finally, LY2090314 caused gene expression dysregulation mainly involving pathways related to transcription regulation, cell proliferation, and chromatin remodeling. For the first time, our work provides the underlying molecular basis for synthetic lethality due to cohesin mutations and suggests that targeting the WNT may be a promising therapeutic approach for tumors carrying mutated cohesin.

Salidroside (SAL) is a phenol glycoside compound found in plants of the Rhodiola genus which has natural antioxidant and free radical scavenging properties. SAL are able to protect against manganese-induced ototoxicity. However, the molecular mechanism by which SAL reduces levels of reactive oxygen species (ROS) is unclear. Here, we established an in vitro gentamicin (GM) ototoxicity model to observe the protective effect of SAL on GM-induced hair cells (HC) damage. Cochlear explants of postnatal day 4 rats were obtained and randomly divided into six groups: two model groups (treatment with 0.2 mM or 0.4 mM GM for 24 h); two 400 μmol/L SAL-pretreated groups pretreatment with SAL for 3 h followed by GM treatment (0.2 mM or 0.4 mM) for 24 h; 400 μmol/L SAL group (treatment with SAL for 24 h); control group (normal cultured cochlear explants). The protective effects of SAL on GM-induced HC damage, and on mRNA and protein levels of antioxidant enzymes were observed. HC loss occurred after 24 h of GM treatment. Pretreatment with SAL significantly reduced GM-induced OHC loss. In cochlear tissues, mRNA and protein levels of NRF2 and HO-1 were enhanced in the GM alone group compared with the SAL pretreatment GM treatment group. SAL may protect against GM-induced ototoxicity by regulating the antioxidant defense system of cochlear tissues; SAL can activate NRF2/HO-1 signaling, inhibit NF-κB activation, activate AKT, and increase inhibitory phosphorylation of GSK3β to decrease GSK3 activity, all of which exert antioxidant effects., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Zhang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Heat stress threatens global wheat (Triticum aestivum) production, causing dramatic yield losses worldwide. Identifying heat tolerance genes and comprehending molecular mechanisms are essential. Here, we identify a heat tolerance gene, TaSG-D1 E286K , in Indian dwarf wheat (Triticum sphaerococcum), which encodes an STKc&#95;GSK3 kinase. TaSG-D1 E286K improves heat tolerance compared to TaSG-D1 by enhancing phosphorylation and stability of downstream target TaPIF4 under heat stress condition. Additionally, we reveal evolutionary footprints of TaPIF4 during wheat selective breeding in China, that is, InDels predominantly occur in the TaPIF4 promoter of Chinese modern wheat cultivars and result in decreased expression level of TaPIF4 in response to heat stress. These sequence variations with negative effect on heat tolerance are mainly introduced from European germplasm. Our study provides insight into heat stress response mechanisms and proposes a potential strategy to improve wheat heat tolerance in future., (© 2024. The Author(s).)

We previously reported the neurotoxic effects of arsenic in the hippocampus. Here, we explored the involvement of Wnt pathway, which contributes to neuronal functions. Administering environmentally relevant arsenic concentrations to postnatal day-60 (PND60) mice demonstrated a dose-dependent increase in hippocampal Wnt3a and its components, Frizzled, phospho-LRP6, Dishevelled and Axin1 at PND90 and PND120. However, p-GSK3-β(Ser9) and β-catenin levels although elevated at PND90, decreased at PND120. Additionally, treatment with Wnt-inhibitor, rDkk1, reduced p-GSK3-β(Ser9) and β-catenin at PND90, but failed to affect their levels at PND120, indicating a time-dependent link with Wnt. To explore other underlying factors, we assessed epidermal growth factor receptor (EGFR) pathway, which interacts with GSK3-β and appears relevant to neuronal functions. We primarily found that arsenic reduced hippocampal phosphorylated-EGFR and its ligand, Heparin-binding EGF-like growth factor (HB-EGF), at both PND90 and PND120. Moreover, treatment with HB-EGF rescued p-GSK3-β(Ser9) and β-catenin levels at PND120, suggesting their HB-EGF/EGFR-dependent regulation at this time point. Additionally, rDkk1, LiCl (GSK3-β-activity inhibitor), or β-catenin protein treatments induced a time-dependent recovery in HB-EGF, indicating potential inter-dependent mechanism between hippocampal Wnt/β-catenin and HB-EGF/EGFR following arsenic exposure. Fluorescence immunolabeling then validated these findings in hippocampal neurons. Further exploration of hippocampal neuronal survival and apoptosis demonstrated that treatment with rDkk1, LiCl, β-catenin and HB-EGF improved Nissl staining and NeuN levels, and reduced cleaved-caspase-3 levels in arsenic-treated mice. Supportively, we detected improved Y-Maze and Passive Avoidance performances for learning-memory functions in these mice. Overall, our study provides novel insights into Wnt/β-catenin and HB-EGF/EGFR pathway interaction in arsenic-induced hippocampal neurotoxicity., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Asmita Garg reports financial support was provided by University Grants Commission, Gov. of India., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The Wnt/β-catenin signaling governs anterior-posterior neural patterning during development. Current human pluripotent stem cell (hPSC) differentiation protocols use a GSK3 inhibitor to activate Wnt signaling to promote posterior neural fate specification. However, GSK3 is a pleiotropic kinase involved in multiple signaling pathways and, as GSK3 inhibition occurs downstream in the signaling cascade, it bypasses potential opportunities for achieving specificity or regulation at the receptor level. Additionally, the specific roles of individual FZD receptors in anterior-posterior patterning are poorly understood. Here, we have characterized the cell surface expression of FZD receptors in neural progenitor cells with different regional identity. Our data reveal unique upregulation of FZD5 expression in anterior neural progenitors, and this expression is downregulated as cells adopt a posterior fate. This spatial regulation of FZD expression constitutes a previously unreported regulatory mechanism that adjusts the levels of β-catenin signaling along the anterior-posterior axis and possibly contributes to midbrain-hindbrain boundary formation. Stimulation of Wnt/β-catenin signaling in hPSCs, using a tetravalent antibody that selectively triggers FZD5 and LRP6 clustering, leads to midbrain progenitor differentiation and gives rise to functional dopaminergic neurons in vitro and in vivo., Competing Interests: Competing interests S.A., S.S.S., J.J.A. and L.L.B. hold shares in AntlerA Therapeutics and are inventors on patents for the antibodies described in the manuscript., (© 2024. Published by The Company of Biologists Ltd.)

Histone acetylation affects numerous cellular processes, such as gene transcription, in both plants and animals. However, the posttranslational modification-participated regulatory networks for crop-yield-related traits are largely unexplored. Here, we characterize a regulatory axis for controlling rice grain size and yield, centered on a potent histone acetyltransferase (chromatin modifier) known as HHC4. HHC4 interacts with and forms a ternary complex with adaptor protein ADA2 and transcription factor bZIP23, wherein bZIP23 recruits HHC4 to specific promoters, and ADA2 and HHC4 additively enhance bZIP23 transactivation on target genes. Meanwhile, HHC4 interacts with and is phosphorylated by GSK3-like kinase TGW3. The resultant phosphorylation triggers several functional impairments of the HHC4 ternary complex. In addition, we identify two major phosphorylation sites of HHC4 by TGW3-sites which play an important role in controlling rice grain size. Overall, our findings thus have critical implications for understanding epigenetic basis of grain size control and manipulating the knowledge for higher crop productivity., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Introduction: Somatostatin (SST) is a peptide hormone primarily synthesized in the digestive and nervous systems. While its impact on the endocrine system is well-established, accumulating evidence suggests a crucial role for SST and its analogues in modulating immune responses. Despite this, the precise mechanism through which SST regulates T cells has remained largely unknown., Methods: To elucidate the impact of SST on human T cells, we conducted a series of experiments involving cell culture assays, molecular analyses, and metabolic profiling. Human T cells were treated with SST, and various parameters including proliferation, cytokine production, and metabolic activities were assessed. Additionally, we employed pharmacological inhibitors and genetic manipulations to dissect the signaling pathways mediating SST's effects on T cells., Results: We showed that SST diminishes T-cell proliferation by influencing IL-2 production and T-cell mitochondrial respiration, while having no discernible impact on TCR-induced glycolysis. Our findings also identified that the regulatory influence of SST on T-cell responses and metabolism is contingent on its receptor, SSTR3. Moreover, we demonstrated that SST governs T-cell responses and metabolism by acting through the T-cell metabolic checkpoint GSK3., Discussion: Our study provides novel insights into the immunoregulatory function of SST in human T cells, highlighting the complex interplay between hormonal signaling and immune regulation. Understanding the molecular mechanisms underlying SST's effects on T cells may offer therapeutic opportunities for manipulating immune responses in various pathological conditions., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Zhang, Feng, Lin and Li.)

Osteoporosis is a systemic disease characterized by an imbalance in bone homeostasis, where osteoblasts fail to fully compensate for the bone resorption induced by osteoclasts. Corylifol A, a flavonoid extracted from Fructus psoraleae, has been identified as a potential treatment for this condition. Predictions from network pharmacology and molecular docking studies suggest that Corylifol A exhibits strong binding affinity with NFATc1, Nrf2, PI3K, and AKT1. Empirical evidence from in vivo experiments indicates that Corylifol A significantly mitigates systemic bone loss induced by ovariectomy by suppressing both the generation and activation of osteoclasts. In vitro studies further showed that Corylifol A inhibited the activation of PI3K-AKT and MAPK pathways and calcium channels induced by RANKL in a time gradient manner, and specifically inhibited the phosphorylation of PI3K, AKT, GSK3 β, ERK, CaMKII, CaMKIV, and Calmodulin. It also diminishes ROS production through Nrf2 activation, leading to a decrease in the expression of key regulators such as NFATcl, C-Fos, Acp5, Mmp9, and CTSK that are involved in osteoclastogenesis. Notably, our RNA-seq analysis suggests that Corylifol A primarily impacts mitochondrial energy metabolism by suppressing oxidative phosphorylation. Collectively, these findings demonstrate that Corylifol A is a novel inhibitor of osteoclastogenesis, offering potential therapeutic applications for diseases associated with excessive bone resorption., Competing Interests: Declaration of Competing Interest The authors state that they have no competing financial interests or personal relationships that could have influenced the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Cloperastine (CLP) is a drug with a central antitussive effect that is used to treat bronchitis. Therefore, we have attempted to examine the anti-inflammatory effects of CLP. CLP reduced the secretion of interleukin (IL)-6, a pro-inflammatory cytokine, from RAW264.7 monocyte/macrophage-linage cells treated with lipopolysaccharide (LPS). IL-6 is a biomarker of sepsis and has been suggested to exacerbate its symptoms. We found that the intraperitoneal administration of CLP reduced IL-6 levels in the lungs and also improved hypothermia in mice with LPS-induced sepsis. CLP ameliorated kidney pathologies such as congestion and increased the survival rate of mice administered with a lethal dose of LPS. To reveal the mechanisms underlying the anti-inflammatory function of CLP, we analysed the intracellular signaling in LPS-treated RAW264.7 cells. CLP induced the phosphorylation of protein kinase B (Akt) and glycogen synthase kinase 3 (GSK3) and also increased the amount of nuclear factor erythroid-2-related factor 2 (Nrf2) in RAW264.7 cells with/without LPS. Wortmannin, an inhibitor of phosphoinositide 3-kinase (PI3K), reduced the upregulated phosphorylation levels of Akt and GSK3 and the increased amount of Nrf2. It also halted the reduction of IL-6 secretion caused by CLP. These results suggest that CLP has an anti-inflammatory function via Akt/GSK3/Nrf2 signaling and could be a candidate drug for the treatment of inflammatory diseases, including sepsis.

The genus Biscogniauxia , a member of the family Xylariaceae, is distributed worldwide with more than 50 recognized taxa. Biscogniauxia species is known as a plant pathogen, typically acting as a parasite on tree bark, although certain members of this genus also function as endophytic microorganisms. Biscogniauxia endophytic strain has received attention in many cases, which includes constituent research leading to the discovery of various bioactive secondary metabolites. Currently, there are a total of 115 chemical compounds belonging to the class of secondary metabolites, and among these compounds, fatty acids have been identified. In addition, the strong pharmacological agents of this genus are (3a S ,4a R ,8a S ,9a R )-3a-hydroxy-8a-methyl-3,5-dimethylenedecahydronaphto [2,3- b ]furan-2(3 H )-one (HDFO) (antifungal), biscopyran (phytotoxic activity), reticulol (antioxidant), biscogniazaphilone A and B (antimycobacterial), and biscogniauxone (Enzyme GSK3 inhibitor). This comprehensive research contributes significantly to the potential discovery of novel drugs produced by Biscogniauxia and holds promise for future development. Importantly, it represents the first-ever review of natural products originating from the Biscogniauxia genus.

Generating stable livestock pluripotent stem cells (PSCs) can be used for complex genome editing, cellular agriculture, gamete generation, regenerative medicine and in vitro breeding schemes. Over the past decade, significant progress has been made in characterizing pluripotency markers for livestock species. In this study, we investigated embryo development and gene expression of the core pluripotency triad (OCT4, NANOG, SOX2) and cell lineage commitment markers (REX1, CDX2, GATA4) in the presence of three small molecules and their combination [PD0325901 (FGF inhibitor), SB431542 (TGFβ inhibitor), and CHIR99021 (GSK3B inhibitor)] from day 2-7 post-insemination in goat. Significant reduction in rate of blastocyst formation was observed when SB was used along with PD or CHIR and their three combinations had more sever effect. SB and CHIR decreased the expression of SOX2 while increasing the GATA4 expression. PD decrease the relative expression of NANOG, OCT4 and GATA4, while increased the expression of REX1. Among the combination of two molecules, only SB + CHIR combination significantly decreased the expression of GATA4, while the combination of the three molecules significantly decreases the expression of NANOG, SOX2 and CDX2. According to these results, the inhibition of the FGF signaling pathway, by PD may lead to blocking the hypoblast formation as observed by reduction of GATA4. OCT4 and NANOG expressions did not show signs of maintenance pluripotency. GATA4, NANOG and OCT4 in the PD group were downregulated and REX1 as EPI-marker was upregulated thus REX1 may be considered as a marker of EPI/ICM in goat., Competing Interests: Declaration of competing interest We confirm this manuscript is currently not being submitted elsewhere and all author is in complete agreement with the contents of this manuscript. In addition, Authors have no conflict of interest to disclose., (Copyright © 2023 Elsevier B.V. All rights reserved.)

This study aimed to investigate whether GSK-3 inhibition (CHIR99021) effectively promoted mineralization by cementoblasts (OCCM-30). OCCM-30 cells were used and treated with different concentrations of CHIR99021 (2.5, 5, and 10 mM). Experiments included proliferation and viability, cellular metabolic activity, gene expression, and mineral nodule formation by Xylene Orange at the experimental time points. In general, CHIR99021 did not significantly affect OCCM-30 viability and cell metabolism (MTT assay) (p > 0.05), but increased OCCM-30 proliferation at 2.5 mM on days 2 and 4 (p < 0.05). Data analysis further showed that inhibition of GSK-3 resulted in increased transcript levels of Axin2 in OCCM-30 cells starting as early as 4 h, and regulated the expression of key bone markers including alkaline phosphatase (Alp), runt-related transcription factor 2 (Runx-2), osteocalcin (Ocn), and osterix (Osx). In addition, CHIR99021 led to an enhanced mineral nodule formation in vitro under both osteogenic and non-osteogenic conditions as early as 5 days after treatment. Altogether, the results of the current study suggest that inhibition of GSK-3 has the potential to promote cementoblast differentiation leading to increased mineral deposition in vitro.

Trastuzumab notably improves the outcome of human epidermal growth factor receptor 2 (HER2)-positive breast cancer patients, however, resistance to trastuzumab remains a major hurdle to clinical treatment. In the present study, we identify a circular RNA intimately linked to trastuzumab resistance. circ-β-TrCP, derived from the back-splicing of β-TrCP exon 7 and 13, confers trastuzumab resistance by regulating NRF2-mediated antioxidant pathway in a KEAP1-independent manner. Concretely, circ-β-TrCP encodes a novel truncated 343-amino acid peptide located in the nucleus, referred as β-TrCP-343aa, which competitively binds to NRF2, blocks SCF β-TrCP -mediated NRF2 proteasomal degradation, and this protective effect of β-TrCP-343aa on NRF2 protein requires GSK3 activity. Subsequently, the elevated NRF2 transcriptionally upregulates a cohort of antioxidant genes, giving rise to trastuzumab resistance. Moreover, the translation ability of circ-β-TrCP is inhibited by eIF3j under both basal and oxidative stress conditions, and eIF3j is transcriptionally repressed by NRF2, thus forming a positive feedback circuit between β-TrCP-343aa and NRF2, expediting trastuzumab resistance. Collectively, our data demonstrate that circ-β-TrCP-encoded β-TrCP protein isoform drives HER2-targeted therapy resistance in a NRF2-dependent manner, which provides potential therapeutic targets for overcoming trastuzumab resistance., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

The liver is critical in maintaining metabolic homeostasis, regulating both anabolic and catabolic processes. Scaffold protein IQ motif-containing GTPase activating protein 2 (IQGAP2) is highly expressed in the liver and implicated in fatty acid uptake. However, its role in coordinating either fed or fasted responses is not well understood. Here we report that IQGAP2 is widely expressed in the liver that is pronounced in the pericentral region. Although control and IQGAP2 knockout mouse model showed comparable hepatic gene expression in the fasted state, we found significant defects in fed state responses. Glycogen levels were reduced in the periportal region when IQGAP2 was deleted. Consistently, we observed a decrease in phosphorylated glycogen synthase kinase 3α and total glycogen synthase protein in the fed IQGAP2 knockout mice which suggest inadequate glycogen synthesis. Moreover, immunoprecipitation of IQGAP2 revealed its interaction with GSK3 and GYS. Furthermore, our study demonstrated that knocking down IQGAP2 in vitro significantly decreased the phosphorylation of AKT and forkhead box O3 proteins downstream of insulin signaling. These findings suggest that IQGAP2 contributes to liver fed state metabolism by interacting with glycogen synthesis regulators and affecting the phosphorylation of insulin pathway components. Our results suggest that IQGAP2 plays a role in regulating fed state metabolism., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Cold stress poses significant limitations on the growth, latex yield, and ecological distribution of rubber trees ( Hevea brasiliensis ). The GSK3-like kinase plays a significant role in helping plants adapt to different biotic and abiotic stresses. However, the functions of GSK3-like kinase BR-INSENSITIVE 2 (BIN2) in Hevea brasiliensis remain elusive. Here, we identified HbBIN2s of Hevea brasiliensis and deciphered their roles in cold stress resistance. The transcript levels of HbBIN2s are upregulated by cold stress. In addition, HbBIN2s are present in both the nucleus and cytoplasm and have the ability to interact with the INDUCER OF CBF EXPRESSION1(HbICE1) transcription factor, a central component in cold signaling. HbBIN2 overexpression in Arabidopsis displays decreased tolerance to chilling stress with a lower survival rate and proline content but a higher level of electrolyte leakage (EL) and malondialdehyde (MDA) than wild type under cold stress. Meanwhile, HbBIN2 transgenic Arabidopsis treated with cold stress exhibits a significant increase in the accumulation of reactive oxygen species (ROS) and a decrease in the activity of antioxidant enzymes. Further investigation reveals that HbBIN2 inhibits the transcriptional activity of HbICE1, thereby attenuating the expression of C-REPEAT BINDING FACTOR (HbCBF1). Consistent with this, overexpression of HbBIN2 represses the expression of CBF pathway cold-regulated genes under cold stress. In conclusion, our findings indicate that HbBIN2 functions as a suppressor of cold stress resistance by modulating HbICE1 transcriptional activity and ROS homeostasis.

Cellular immunity mediated by CD8 + T cells plays an indispensable role in bacterial and viral clearance and cancers. However, persistent antigen stimulation of CD8 + T cells leads to an exhausted or dysfunctional cellular state characterized by the loss of effector function and high expression of inhibitory receptors during chronic viral infection and in tumors. Numerous studies have shown that glycogen synthase kinase 3 (GSK3) controls the function and development of immune cells, but whether GSK3 affects CD8 + T cells is not clearly elucidated. Here, we demonstrate that mice with deletion of Gsk3α and Gsk3β in activated CD8 + T cells (DKO) exhibited decreased CTL differentiation and effector function during acute and chronic viral infection. In addition, DKO mice failed to control tumor growth due to the upregulated expression of inhibitory receptors and augmented T-cell exhaustion in tumor-infiltrating CD8 + T cells. Strikingly, anti-PD-1 immunotherapy substantially restored tumor rejection in DKO mice. Mechanistically, GSK3 regulates T-cell exhaustion by suppressing TCR-induced nuclear import of NFAT, thereby in turn dampening NFAT-mediated exhaustion-related gene expression, including TOX/TOX2 and PD-1. Thus, we uncovered the molecular mechanisms underlying GSK3 regulation of CTL differentiation and T-cell exhaustion in anti-tumor immune responses., (© 2023. The Author(s), under exclusive licence to CSI and USTC.)

In the adult mammalian brain, neural stem cells (NSCs) located in highly restricted niches sustain the generation of new neurons that integrate into existing circuits. A reduction in adult neurogenesis is linked to ageing and neurodegeneration, whereas dysregulation of proliferation and survival of NSCs have been hypothesized to be at the origin of glioma. Thus, unravelling the molecular underpinnings of the regulated activation that NSCs must undergo to proliferate and generate new progeny is of considerable relevance. Current research has identified cues promoting or restraining NSCs activation. Yet, whether NSCs depend on external signals to survive or if intrinsic factors establish a threshold for sustaining their viability remains elusive, even if this knowledge could involve potential for devising novel therapeutic strategies. Kidins220 (Kinase D-interacting substrate of 220 kDa) is an essential effector of crucial pathways for neuronal survival and differentiation. It is dramatically altered in cancer and in neurological and neurodegenerative disorders, emerging as a regulatory molecule with important functions in human disease. Herein, we discover severe neurogenic deficits and hippocampal-based spatial memory defects accompanied by increased neuroblast death and high loss of newly formed neurons in Kidins220 deficient mice. Mechanistically, we demonstrate that Kidins220-dependent activation of AKT in response to EGF restraints GSK3 activity preventing NSCs apoptosis. We also show that NSCs with Kidins220 can survive with lower concentrations of EGF than the ones lacking this molecule. Hence, Kidins220 levels set a molecular threshold for survival in response to mitogens, allowing adult NSCs growth and expansion. Our study identifies Kidins220 as a key player for sensing the availability of growth factors to sustain adult neurogenesis, uncovering a molecular link that may help paving the way towards neurorepair., (© 2023. The Author(s).)

Increasing evidence supports a role for inflammation in the early development and progression of retinal complications caused by diabetes. We recently demonstrated that the stress response protein regulated in development and DNA damage response 1 (REDD1) promotes diabetes-induced retinal inflammation by sustaining canonical activation of nuclear transcription factor, NF-κB. The studies here were designed to identify signaling events whereby REDD1 promotes NF-κB activation in the retina of diabetic mice. We observed increased REDD1 expression in the retina of mice after 16 weeks of streptozotocin (STZ)-induced diabetes and found that REDD1 was essential for diabetes to suppress inhibitory phosphorylation of glycogen synthase kinase 3β (GSK3β) at S9. In human retinal MIO-M1 Müller cell cultures, REDD1 deletion prevented dephosphorylation of GSK3β and increased NF-κB activation in response to hyperglycemic conditions. Expression of a constitutively active GSK3β variant restored NF-κB activation in cells deficient for REDD1. In cells exposed to hyperglycemic conditions, GSK3β knockdown inhibited NF-κB activation and proinflammatory cytokine expression by preventing inhibitor of κB kinase complex autophosphorylation and inhibitor of κB degradation. In both the retina of STZ-diabetic mice and in Müller cells exposed to hyperglycemic conditions, GSK3 inhibition reduced NF-κB activity and prevented an increase in proinflammatory cytokine expression. In contrast with STZ-diabetic mice receiving a vehicle control, macrophage infiltration was not observed in the retina of STZ-diabetic mice treated with GSK3 inhibitor. Collectively, the findings support a model wherein diabetes enhances REDD1-dependent activation of GSK3β to promote canonical NF-κB signaling and the development of retinal inflammation., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Mixed-lineage leukemia 1 (MLL1) introduces 1-, 2- and 3-methylation into histone H3K4 through the evolutionarily conserved set domain. In this study, bovine embryonic stem cells (bESCs, known as bESCs-F7) were established from in vitro-fertilized (IVF) embryos via Wnt signaling inhibition; however, their contribution to the endoderm in vivo is limited. To improve the quality of bESCs, MM-102, an inhibitor of MLL1, was applied to the culture. The results showed that MLL1 inhibition along with GSK3 and MAP2K inhibition (3i) at the embryonic stage did not affect bESCs' establishment and pluripotency. MLL1 inhibition improved the pluripotency and differentiation potential of bESCs via the up-regulation of stem cell signaling pathways such as PI3K-Akt and WNT. MLL1 inhibition decreased H3K4me1 modification at the promoters and altered the distribution of DNA methylation in bESCs. In summary, MLL1 inhibition gives bESCs better pluripotency, and its application may provide high-quality pluripotent stem cells for domestic animals.

Glycogen synthase kinase-3 (GSK-3) is a serine/threonine kinase that has been implicated in numerous oncogenic processes. GSK-3 inhibitor elraglusib (9-ING-41) has shown promising preclinical and clinical antitumor activity across multiple tumor types. Despite promising early-phase clinical trial results, there have been limited efforts to characterize the potential immunomodulatory properties of elraglusib. We report that elraglusib promotes immune cell-mediated tumor cell killing of microsatellite stable colorectal cancer (CRC) cells. Mechanistically, elraglusib sensitized CRC cells to immune-mediated cytotoxicity and enhanced immune cell effector function. Using western blots, we found that elraglusib decreased CRC cell expression of NF-κB p65 and several survival proteins. Using microarrays, we discovered that elraglusib upregulated the expression of proapoptotic and antiproliferative genes and downregulated the expression of cell proliferation, cell cycle progression, metastasis, TGFβ signaling, and anti-apoptotic genes in CRC cells. Elraglusib reduced CRC cell production of immunosuppressive molecules such as VEGF, GDF-15, and sPD-L1. Elraglusib increased immune cell IFN-γ secretion, which upregulated CRC cell gasdermin B expression to potentially enhance pyroptosis. Elraglusib enhanced immune effector function resulting in augmented granzyme B, IFN-γ, TNF-α, and TRAIL production. Using a syngeneic, immunocompetent murine model of microsatellite stable CRC, we evaluated elraglusib as a single agent or combined with immune checkpoint blockade (anti-PD-1/L1) and observed improved survival in the elraglusib and anti-PD-L1 group. Murine responders had increased tumor-infiltrating T cells, augmented granzyme B expression, and fewer regulatory T cells. Murine responders had reduced immunosuppressive (VEGF, VEGFR2) and elevated immunostimulatory (GM-CSF, IL-12p70) cytokine plasma concentrations. To determine the clinical significance, we then utilized elraglusib-treated patient plasma samples and found that reduced VEGF and BAFF and elevated IL-1 beta, CCL22, and CCL4 concentrations correlated with improved survival. Using paired tumor biopsies, we found that tumor-infiltrating immune cells had a reduced expression of inhibitory immune checkpoints (VISTA, PD-1, PD-L2) and an elevated expression of T-cell activation markers (CTLA-4, OX40L) after elraglusib treatment. These results address a significant gap in knowledge concerning the immunomodulatory mechanisms of GSK-3 inhibitor elraglusib, provide a rationale for the clinical evaluation of elraglusib in combination with immune checkpoint blockade, and are expected to have an impact on additional tumor types, besides CRC., Competing Interests: Elraglusib (9-ING-41) has been licensed to Actuate Therapeutics. K.E.H., P.S., and W.S.E-D. receive research funding for preclinical studies from Actuate Therapeutics, Inc (March 2022- Feb. 2024). B.A.C. received institutional funding for a clinical trial related to 9-ING-41 from Actuate Therapeutics, Inc. F.J.G. has served as a consultant to Actuate Therapeutics, Inc. Daniel Newhouse is an employee and shareholder of NanoString Technologies Inc. All remaining authors report no disclosures.

Phosphatidylinositol 4-kinase IIα (PI4KIIα) generates essential phospholipids and is a cargo for endosomal adaptor proteins. Activity-dependent bulk endocytosis (ADBE) is the dominant synaptic vesicle endocytosis mode during high neuronal activity and is sustained by glycogen synthase kinase 3β (GSK3β) activity. We reveal the GSK3β substrate PI4KIIα is essential for ADBE via its depletion in primary neuronal cultures. Kinase-dead PI4KIIα rescues ADBE in these neurons but not a phosphomimetic form mutated at the GSK3β site, Ser-47. Ser-47 phosphomimetic peptides inhibit ADBE in a dominant-negative manner, confirming that Ser-47 phosphorylation is essential for ADBE. Phosphomimetic PI4KIIα interacts with a specific cohort of presynaptic molecules, two of which, AGAP2 and CAMKV, are also essential for ADBE when depleted in neurons. Thus, PI4KIIα is a GSK3β-dependent interaction hub that silos essential ADBE molecules for liberation during neuronal activity., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Dermal adipocyte lineage cells are highly plastic and can undergo reversible differentiation and dedifferentiation in response to various stimuli. Using single-cell RNA sequencing of developing or wounded mouse skin, we classify dermal fibroblasts (dFBs) into distinct non-adipogenic and adipogenic cell states. Cell differentiation trajectory analyses identify IL-1-NF-κB and WNT-β-catenin as top signaling pathways that positively and negatively associate with adipogenesis, respectively. Upon wounding, activation of adipocyte progenitors and wound-induced adipogenesis are mediated in part by neutrophils through the IL-1R-NF-κB-CREB signaling axis. In contrast, WNT activation, by WNT ligand and/or ablation of Gsk3, inhibits the adipogenic potential of dFBs but promotes lipolysis and dedifferentiation of mature adipocytes, contributing to myofibroblast formation. Finally, sustained WNT activation and inhibition of adipogenesis is seen in human keloids. These data reveal molecular mechanisms underlying the plasticity of dermal adipocyte lineage cells, defining potential therapeutic targets for defective wound healing and scar formation., Competing Interests: Declaration of interests R.L.G. is a co-founder, scientific advisor, consultant for, and has equity in MatriSys Biosciences., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)