Glycogen Synthase Kinase-3β Inhibition with 9-ING-41 Attenuates the Progression of Pulmonary Fibrosis

Glycogen synthase kinase 3 activity enhances liver inflammation in MASH

Background & Aims

Metabolic dysfunction-associated steatohepatitis (MASH) is characterized by excessive circulating toxic lipids, hepatic steatosis, and liver inflammation. Monocyte adhesion to liver sinusoidal endothelial cells (LSECs) and transendothelial migration (TEM) are crucial in the inflammatory process. Under lipotoxic stress, LSECs develop a proinflammatory phenotype known as endotheliopathy. However, mediators of endotheliopathy remain unclear.

Methods

Primary mouse LSECs isolated from C57BL/6J mice fed chow or MASH-inducing diets rich in fat, fructose, and cholesterol (FFC) were subjected to multi-omics profiling. Mice with established MASH resulting from a choline-deficient high-fat diet (CDHFD) or FFC diet were also treated with two structurally distinct GSK3 inhibitors (LY2090314 and elraglusib [9-ING-41]).

Results

Integrated pathway analysis of the mouse LSEC proteome and transcriptome indicated that leukocyte TEM and focal adhesion were the major pathways altered in MASH. Kinome profiling of the LSEC phosphoproteome identified glycogen synthase kinase (GSK)-3β as the major kinase hub in MASH. GSK3β-activating phosphorylation was increased in primary human LSECs treated with the toxic lipid palmitate and in human MASH. Palmitate upregulated the expression of C-X-C motif chemokine ligand 2, intracellular adhesion molecule 1, and phosphorylated focal adhesion kinase, via a GSK3-dependent mechanism. Congruently, the adhesive and transendothelial migratory capacities of primary human neutrophils and THP-1 monocytes through the LSEC monolayer under lipotoxic stress were reduced by GSK3 inhibition. Treatment with the GSK3 inhibitors LY2090314 and elraglusib ameliorated liver inflammation, injury, and fibrosis in FFC- and CDHFD-fed mice, respectively. Immunophenotyping using cytometry by mass cytometry by time of flight of intrahepatic leukocytes from CDHFD-fed mice treated with elraglusib showed reduced infiltration of proinflammatory monocyte-derived macrophages and monocyte-derived dendritic cells.

Conclusion

GSK3 inhibition attenuates lipotoxicity-induced LSEC endotheliopathy and could serve as a potential therapeutic strategy for treating human MASH.

Impact and Implications

LSECs under lipotoxic stress in MASH develop a proinflammatory phenotype known as endotheliopathy, with obscure mediators and functional outcomes. The current study identified GSK3 as the major driver of LSEC endotheliopathy, examined its pathogenic role in myeloid cell-associated liver inflammation, and defined the therapeutic efficacy of pharmacological GSK3 inhibitors in murine MASH. This study provides preclinical data for the future investigation of GSK3 pharmacological inhibitors in human MASH. The results of this study are important to hepatologists, vascular biologists, and investigators studying the mechanisms of inflammatory liver disease and MASH, as well as those interested in drug development.

Curculigoside Attenuates Endoplasmic Reticulum Stress-Induced Epithelial Cell and Fibroblast Senescence by Regulating the SIRT1-P300 Signaling Pathway

The senescence of alveolar epithelial cells (AECs) and fibroblasts plays a pivotal role in the pathogenesis of idiopathic pulmonary fibrosis (IPF), a condition lacking specific therapeutic interventions. Curculigoside (CCG), a prominent bioactive constituent of Curculigo, exhibits anti-osteoporotic and antioxidant activities. Our investigation aimed to elucidate the anti-senescence and anti-fibrotic effects of CCG in experimental pulmonary fibrosis and delineate its underlying molecular mechanisms. Our findings demonstrate that CCG attenuates bleomycin-induced pulmonary fibrosis and lung senescence in murine models, concomitantly ameliorating lung function impairment. Immunofluorescence staining for senescence marker p21, alongside SPC or α-SMA, suggested that CCG's mitigation of lung senescence correlates closely with the deceleration of senescence in AECs and fibroblasts. In vitro, CCG mitigated H2O2-induced senescence in AECs and the natural senescence of primary mouse fibroblasts. Mechanistically, CCG can upregulate SIRT1 expression, downregulating P300 expression, enhancing Trim72 expression to facilitate P300 ubiquitination and degradation, reducing the acetylation levels of antioxidant enzymes, and upregulating their expression levels. These actions collectively inhibited endoplasmic reticulum stress (ERS) and alleviated senescence. Furthermore, the anti-senescence effects and mechanisms of CCG were validated in a D-galactose (D-gal)-induced progeroid model. This study provides novel insights into the mechanisms underlying the action of CCG in cellular senescence and chronic diseases, offering potential avenues for the development of innovative drugs or therapeutic strategies.

Therapeutic Potential Effect of Glycogen Synthase Kinase 3 Beta (GSK-3β) Inhibitors in Parkinson Disease: Exploring an Overlooked Avenue

Parkinson's disease (PD) is a progressive neurodegenerative disease of the brain due to degeneration of dopaminergic neurons in the substantia nigra (SN). Glycogen synthase kinase 3 beta (GSK-3β) is implicated in the pathogenesis of PD. Therefore, the purpose of the present review was to revise the mechanistic role of GSK-3β in PD neuropathology, and how GSK-3β inhibitors affect PD neuropathology. GSK-3 is a conserved threonine/serine kinase protein that is intricate in the regulation of cellular anabolic and catabolic pathways by modulating glycogen synthase. Over-expression of GSK-3β is also interconnected with the development of different neurodegenerative diseases. However, the underlying mechanism of GSK-3β in PD neuropathology is not fully clarified. Over-expression of GSK-3β induces the development of PD by triggering mitochondrial dysfunction and oxidative stress in the dopaminergic neurons of the SN. NF-κB and NLRP3 inflammasome are activated in response to dysregulated GSK-3β in PD leading to progressive neuronal injury. Higher expression of GSK-3β in the early stages of PD neuropathology might contribute to the reduction of neuroprotective brain-derived neurotrophic factor (BDNF). Thus, GSK-3β inhibitors may be effective in PD by reducing inflammatory and oxidative stress disorders which are associated with degeneration of dopaminergic in the SN.

Therapeutic potential of traditional Chinese medicine for interstitial lung disease

ETHNOPHARMACOLOGICAL RELEVANCE

Interstitial lung disease (ILD) is a chronic lung dysfunction disease with a poor prognosis and poor recovery. The clinically used therapeutic drugs, such as glucocorticoids and immunosuppressants, have no significant therapeutic effect and are accompanied with severe side effects. In recent years, considerable progress has been made in exploring and applying natural herb components for treating ILD. Traditional Chinese Medicine (TCM) possesses innate, non-toxic characteristics and offers advantages in preventing and treating pulmonary ailments. However, a comprehensive study of TCM on ILD therapy has not yet been reviewed.

AIM OF THE REVIEW

This review aimed to provide a comprehensive summary of the monomer components, total extracts, and prescriptions of TCM for ILD therapy, elucidating their molecular mechanisms to serve as a reference in treating ILD.

MATERIALS AND METHODS

The literature information was searched in the PubMed, Web of Science databases. The search keywords included 'interstitial lung disease', 'lung fibrosis' or 'pulmonary fibrosis', and 'traditional Chinese medicine', 'traditional herbal medicine', or 'herb medicine'.

RESULTS

The active components of single herbs, such as alkaloids, flavonoids, terpenoids, phenols, and quinones, have potential therapeutic effects on ILD. The active extracts and prescriptions were also summarized and analyzed. The herbs, Glycyrrhiza uralensis Fisch. (Gancao), Astragalus membranaceus Fisch. Bunge. (Huangqi) and Angelicasinensis (Oliv.) Diels (Danggui), play significant roles in the treatment of ILD. The mechanisms involve the inhibition of inflammatory factor release, anti-oxidative injury, and interference with collagen production, etc. CONCLUSION: This review examines the therapeutic potential of TCM for ILD and elucidates its molecular mechanisms, demonstrating that mitigating inflammation and oxidative stress, modulating the immune system, and promoting tissue repair are efficacious strategies for ILD therapy. The depth research will yield both theoretical and practical implications.

The mTORC2/SGK1/NDRG1 Signaling Axis Is Critical for the Mesomesenchymal Transition of Pleural Mesothelial Cells and the Progression of Pleural Fibrosis

Progressive lung scarring because of persistent pleural organization often results in pleural fibrosis (PF). This process affects patients with complicated parapneumonic pleural effusions, empyema, and other pleural diseases prone to loculation. In PF, pleural mesothelial cells undergo mesomesenchymal transition (MesoMT) to become profibrotic, characterized by increased expression of α-smooth muscle actin and matrix proteins, including collagen-1. In our previous study, we showed that blocking PI3K/Akt signaling inhibits MesoMT induction in human pleural mesothelial cells (HPMCs) (1). However, the downstream signaling pathways leading to MesoMT induction remain obscure. Here, we investigated the role of mTOR complexes (mTORC1/2) in MesoMT induction. Our studies show that activation of the downstream mediator mTORC1/2 complex is, likewise, a critical component of MesoMT. Specific targeting of mTORC1/2 complex using pharmacological inhibitors such as INK128 and AZD8055 significantly inhibited transforming growth factor β (TGF-β)-induced MesoMT markers in HPMCs. We further identified the mTORC2/Rictor complex as the principal contributor to MesoMT progression induced by TGF-β. Knockdown of Rictor, but not Raptor, attenuated TGF-β-induced MesoMT in these cells. In these studies, we further show that concomitant activation of the SGK1/NDRG1 signaling cascade is essential for inducing MesoMT. Targeting SGK1 and NDRG1 with siRNA and small molecular inhibitors attenuated TGF-β-induced MesoMT in HPMCs. Additionally, preclinical studies in our Streptococcus pneumoniae-mediated mouse model of PF showed that inhibition of mTORC1/2 with INK128 significantly attenuated the progression of PF in subacute and chronic injury. In conclusion, our studies demonstrate that mTORC2/Rictor-mediated activation of SGK1/NDRG1 is critical for MesoMT induction and that targeting this pathway could inhibit or even reverse the progression of MesoMT and PF.

Beraprost sodium attenuates the development of myocardial fibrosis after myocardial infarction by regulating GSK-3β expression in rats

OBJECTIVE

The aim of this study was to elucidate the mechanism of beraprost sodium (BPS) in the intervention of myocardial fibrosis after myocardial infarction (MI) through glycogen synthase kinase-3β (GSK-3β) and to provide new ideas for intervention in myocardial fibrosis.

MATERIALS AND METHODS

MI model rats given BPS and cardiac fibroblasts (CFs) treated with BPS and TGF-β. HE staining and Masson staining were used to detect the pathological changes of myocardial tissue. Fibrotic markers were detected by immunohistochemical staining. The expressions of GSK-3β, cAMP response element binding protein (CREB), and p-CREB were analyzed by qPCR and western blot analysis. EDU staining was used to detect the proliferation of CFs. The promoter activity of GSK-3β was detected by luciferase assay. Chromatin immunoprecipitation assay was used to detect the binding levels of GSK-3β promoter and Y-box binding protein 1 (YBX1). The levels of intracellular cyclic adenosine monophosphate (cAMP) were analyzed by enzyme-linked immunosorbent assay (ELISA).

RESULTS

After operation, BPS improved myocardial fibrosis and upregulated GSK-3β protein expression in male SD rats. BPS can down-regulate α-smooth muscle actin (α-SMA) level and up-regulate GSK-3β protein expression in CFs after TGF-β stimulation. Furthermore, GSK-3β knockdown can reverse the effect of BPS on TGF-β-activated CFs, enhance α-SMA expression, and promote the proliferation of CFs. BPS could regulate GSK-3β expression by promoting the binding of GSK-3β promoter to YBX1. BPS induced upregulation of p-CREB and cAMP, resulting in reduced fibrosis, which was reversed by the knockdown of GSK-3β or prostaglandin receptor (IPR) antagonists.

CONCLUSION

BPS treatment increased the binding of YBX1 to the GSK-3β promoter, and GSK-3β protein expression was upregulated, which further caused the upregulation of p-CREB and cAMP, and finally inhibited myocardial fibrosis.

MARCH8 downregulation modulates profibrotic responses including myofibroblast differentiation

Interstitial lung diseases can result in poor patient outcomes, especially in idiopathic pulmonary fibrosis (IPF), a severe interstitial lung disease with unknown causes. The lack of treatment options requires further understanding of the pathological process/mediators. Membrane-associated RING-CH 8 (MARCH8) has been implicated in immune function regulation and inflammation, however, its role in the development of pulmonary fibrosis and particularly the fibroblast to myofibroblast transition (FMT) remains a gap in existing knowledge. In this study, we demonstrated decreased MARCH8 expression in patients with IPF compared with non-PF controls and in bleomycin-induced PF. TGF-β dose- and time-dependently decreased MARCH8 expression in normal and IPF human lung fibroblast (HLFs), along with induction of FMT markers α-SMA, collagen type I (Col-1), and fibronectin (FN). Interestingly, overexpression of MARCH8 significantly suppressed TGF-β-induced expression of α-SMA, Col-1, and FN. By contrast, the knockdown of MARCH8 using siRNA upregulated basal expression of α-SMA/Col-1/FN. Moreover, MARCH8 knockdown enhanced TGF-β-induced FMT marker expression. These data clearly show that MARCH8 is a critical "brake" for FMT and potentially affects PF. We further found that TGF-β suppressed MARCH8 mRNA expression and the proteasome inhibitor MG132 failed to block MARCH8 decrease induced by TGF-β. Conversely, TGF-β decreases mRNA levels of MARCH8 in a dose- and time-dependent manner, suggesting the transcriptional regulation of MARCH8 by TGF-β. Mechanistically, MARCH8 overexpression suppressed TGF-β-induced Smad2/3 phosphorylation, which may account for the observed effects. Taken together, this study demonstrated an unrecognized role of MARCH8 in negatively regulating FMT and profibrogenic responses relevant to interstitial lung diseases.NEW & NOTEWORTHY MARCH8 is an important modulator of inflammation, immunity, and other cellular processes. We found that MARCH8 expression is downregulated in the lungs of patients with idiopathic pulmonary fibrosis (IPF) and experimental models of pulmonary fibrosis. Furthermore, TGF-β1 decreases MARCH8 transcriptionally in human lung fibroblasts (HLFs). MARCH8 overexpression blunts TGF-β1-induced fibroblast to myofibroblast transition while knockdown of MARCH8 drives this profibrotic change in HLFs. The findings support further exploration of MARCH8 as a novel target in IPF.

Bisindolyl Maleimides and Indolylmaleimide Derivatives-A Review of Their Synthesis and Bioactivity

The evolution of bisindolyl maleimides and indolyl maleimide derivatives and their unique biological activities have stimulated great interest in medicinal chemistry programs. Bisindolylmaleimide (BIM)-type compounds arise from natural sources such as arcyriarubin and are biosynthetically related to indolocarbazoles. BIMs are commonly the immediate synthetic precursors of indolocarbazoles, lacking a central bond between the two aromatic units and making them more flexible and drug-like. Synthetic endeavours within this class of compounds are broad and have led to the development of both remarkably potent and selective protein kinase inhibitors. Clinical BIM examples include ruboxistaurin and enzastaurin, which are highly active inhibitors of protein kinase C-β. While BIMs are widely recognised as protein kinase inhibitors, other modes of activity have been reported, including the inhibition of calcium signalling and antimicrobial activity. Critically, structural differences can be used to exploit new bioactivity and therefore it is imperative to discover new chemical entities to address new targets. BIMs can be highly functionalised or chemically manipulated, which provides the opportunity to generate new derivatives with unique biological profiles. This review will collate new synthetic approaches to BIM-type compounds and their associated bioactivities with a focus on clinical applications.

Integrative multi-omics analysis reveals novel idiopathic pulmonary fibrosis endotypes associated with disease progression

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is characterized by the accumulation of extracellular matrix in the pulmonary interstitium and progressive functional decline. We hypothesized that integration of multi-omics data would identify clinically meaningful molecular endotypes of IPF.

METHODS

The IPF-PRO Registry is a prospective registry of patients with IPF. Proteomic and transcriptomic (including total RNA [toRNA] and microRNA [miRNA]) analyses were performed using blood collected at enrollment. Molecular data were integrated using Similarity Network Fusion, followed by unsupervised spectral clustering to identify molecular subtypes. Cox proportional hazards models tested the relationship between these subtypes and progression-free and transplant-free survival. The molecular subtypes were compared to risk groups based on a previously described 52-gene (toRNA expression) signature. Biological characteristics of the molecular subtypes were evaluated via linear regression differential expression and canonical pathways (Ingenuity Pathway Analysis [IPA]) over-representation analyses.

RESULTS

Among 232 subjects, two molecular subtypes were identified. Subtype 1 (n = 105, 45.3%) and Subtype 2 (n = 127, 54.7%) had similar distributions of age (70.1 +/- 8.1 vs. 69.3 +/- 7.6 years; p = 0.31) and sex (79.1% vs. 70.1% males, p = 0.16). Subtype 1 had more severe disease based on composite physiologic index (CPI) (55.8 vs. 51.2; p = 0.002). After adjusting for CPI and antifibrotic treatment at enrollment, subtype 1 experienced shorter progression-free survival (HR 1.79, 95% CI 1.28,2.56; p = 0.0008) and similar transplant-free survival (HR 1.30, 95% CI 0.87,1.96; p = 0.20) as subtype 2. There was little agreement in the distribution of subjects to the molecular subtypes and the risk groups based on 52-gene signature (kappa = 0.04, 95% CI= -0.08, 0.17), and the 52-gene signature risk groups were associated with differences in transplant-free but not progression-free survival. Based on heatmaps and differential expression analyses, proteins and miRNAs (but not toRNA) contributed to classification of subjects to the molecular subtypes. The IPA showed enrichment in pulmonary fibrosis-relevant pathways, including mTOR, VEGF, PDGF, and B-cell receptor signaling.

CONCLUSIONS

Integration of transcriptomic and proteomic data from blood enabled identification of clinically meaningful molecular endotypes of IPF. If validated, these endotypes could facilitate identification of individuals likely to experience disease progression and enrichment of clinical trials.

TRIAL REGISTRATION

NCT01915511.

The uPA/uPAR System Orchestrates the Inflammatory Response, Vascular Homeostasis, and Immune System in Fibrosis Progression

Fibrotic diseases, such as systemic sclerosis (SSc), idiopathic pulmonary fibrosis, renal fibrosis and liver cirrhosis are characterized by tissue overgrowth due to excessive extracellular matrix (ECM) deposition. Fibrosis progression is caused by ECM overproduction and the inhibition of ECM degradation due to several events, including inflammation, vascular endothelial dysfunction, and immune abnormalities. Recently, it has been reported that urokinase plasminogen activator (uPA) and its receptor (uPAR), known to be fibrinolytic factors, orchestrate the inflammatory response, vascular homeostasis, and immune homeostasis system. The uPA/uPAR system may show promise as a potential therapeutic target for fibrotic diseases. This review considers the role of the uPA/uPAR system in the progression of fibrotic diseases.

TGFβ Governs the Pleiotropic Activity of NDRG1 in Triple-Negative Breast Cancer Progression

In triple-negative breast cancer (TNBC), the pleiotropic NDRG1 (N-Myc downstream regulated gene 1) promotes progression and worse survival, yet contradictory results were documented, and the mechanisms remain unknown. Phosphorylation and localization could drive NDRG1 pleiotropy, nonetheless, their role in TNBC progression and clinical outcome was not investigated. We found enhanced p-NDRG1 (Thr346) by TGFβ1 and explored whether it drives NDRG1 pleiotropy and TNBC progression. In tissue microarrays of 81 TNBC patients, we identified that staining and localization of NDRG1 and p-NDRG1 (Thr346) are biomarkers and risk factors associated with shorter overall survival. We found that TGFβ1 leads NDRG1, downstream of GSK3β, and upstream of NF-κB, to differentially regulate migration, invasion, epithelial-mesenchymal transition, tumor initiation, and maintenance of different populations of cancer stem cells (CSCs), depending on the progression stage of tumor cells, and the combination of TGFβ and GSK3β inhibitors impaired CSCs. The present study revealed the striking importance to assess both total NDRG1 and p-NDRG1 (Thr346) positiveness and subcellular localization to evaluate patient prognosis and their stratification. NDRG1 pleiotropy is driven by TGFβ to differentially promote metastasis and/or maintenance of CSCs at different stages of tumor progression, which could be abrogated by the inhibition of TGFβ and GSK3β.

DISC1 inhibits GSK3β activity to prevent tau hyperphosphorylation under diabetic encephalopathy

Diabetic encephalopathy (DE) is a common complication of type 2 diabetes (T2D), especially in those patients with long T2D history. Persistent high glucose (HG) stimulation leads to neuron damage and manifests like Alzheimer's disease's pathological features such as neurofilament tangle. However, the precise mechanism of high-glucose-induced tau hyperphosphorylation is not fully revealed. We here gave evidence that Disrupted in schizophrenia 1 protein (DISC1) could interact with glycogen synthase kinase 3β (GSK3β) and inhibit its activity to prevent tau hyperphosphorylation. By using DB/DB mice as animal model and HG-treated N2a cell as cell model, we found that DISC1 was downregulated both in vivo and in vitro, complicated with Tau hyperphosphorylation and GSK3β activation. Further, we identified DISC1 interacted with GSK3β by its 198th-237th amino acid residues. Overexpression of full length DISC1 but not mutated DISC1 lacking this domain could prevent HG induced tau hyperphosphorylation. Taken together, our work revealed DISC1 could be an important negative modulators of tau phosphorylation, and suggested that preservation of DISC1 could prevent HG induced neuron damage.

Systematic Analysis Strategy Based on Network Pharmacology to Investigate the Potential Mechanism of Fritillaria thunbergii Miq. against Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a long-term, distressing, and age-related interstitial lung disease characterized by a complicated etiology and irreversible progression. Fritillaria thunbergii Miq. (Zhe Beimu, ZBM) is frequently used for its heat-clearing and phlegm-resolving properties in herbal compounds for the treatment of IPF. However, the specific mechanisms underlying the effects of ZBM against IPF have not yet been reported. In this study, we applied a systematic analysis strategy based on network pharmacology to explore the probable core targets and major pathways of ZBM against IPF. In addition, molecular docking simulation and quantitative real-time polymerase chain reaction (qRT-PCR) were performed to preliminarily investigate the possible mechanisms underlying the therapeutic effects of ZBM on IPF. We collected a total of 86 components of ZBM and used network pharmacology analysis to screen nine presumptive targets of ZBM against IPF. The molecular-docking results indicated that the components of ZBM exhibited good binding activity with presumptive targets. The qRT-PCR results also suggested that ZBM may partly alleviate IPF by regulating the expression of presumptive targets. This study laid the foundation for further clinical applications of ZBM and the development of IPF-related therapeutic products.

Epithelial coxsackievirus adenovirus receptor promotes house dust mite-induced lung inflammation

Airway inflammation and remodelling are important pathophysiologic features in asthma and other respiratory conditions. An intact epithelial cell layer is crucial to maintain lung homoeostasis, and this depends on intercellular adhesion, whilst damaged respiratory epithelium is the primary instigator of airway inflammation. The Coxsackievirus Adenovirus Receptor (CAR) is highly expressed in the epithelium where it modulates cell-cell adhesion stability and facilitates immune cell transepithelial migration. However, the contribution of CAR to lung inflammation remains unclear. Here we investigate the mechanistic contribution of CAR in mediating responses to the common aeroallergen, House Dust Mite (HDM). We demonstrate that administration of HDM in mice lacking CAR in the respiratory epithelium leads to loss of peri-bronchial inflammatory cell infiltration, fewer goblet-cells and decreased pro-inflammatory cytokine release. In vitro analysis in human lung epithelial cells confirms that loss of CAR leads to reduced HDM-dependent inflammatory cytokine release and neutrophil migration. Epithelial CAR depletion also promoted smooth muscle cell proliferation mediated by GSK3β and TGF-β, basal matrix production and airway hyperresponsiveness. Our data demonstrate that CAR coordinates lung inflammation through a dual function in leucocyte recruitment and tissue remodelling and may represent an important target for future therapeutic development in inflammatory lung diseases.

DOCK2 contributes to pulmonary fibrosis by promoting lung fibroblast to myofibroblast transition

Idiopathic pulmonary fibrosis (IPF) is the most common chronic interstitial lung disease and is characterized by progressive scarring of the lung. Transforming growth factor-β (TGF-β) signaling plays an essential role in IPF and drives fibroblast to myofibroblast transition (FMT). Dedicator of cytokinesis 2 (DOCK2) is known to regulate diverse immune functions by activating Rac and has been recently implicated in pleural fibrosis. We now report a novel role of DOCK2 in pulmonary fibrosis development by mediating FMT. In primary normal and IPF human lung fibroblasts (HLFs), TGF-β induced DOCK2 expression concurrent with FMT markers, smooth muscle α-actin (α-SMA), collagen-1, and fibronectin. Knockdown of DOCK2 significantly attenuated TGF-β-induced expression of these FMT markers. In addition, we found that the upregulation of DOCK2 by TGF-β is dependent on both Smad3 and ERK pathways as their respective inhibitors blocked TGF-β-mediated induction. TGF-β also stabilized DOCK2 protein, which contributes to increased DOCK2 expression. In addition, DOCK2 was also dramatically induced in the lungs of patients with IPF and in bleomycin, and TGF-β induced pulmonary fibrosis in C57BL/6 mice. Furthermore, increased lung DOCK2 expression colocalized with the FMT marker α-SMA in the bleomycin-induced pulmonary fibrosis model, implicating DOCK2 in the regulation of lung fibroblast phenotypic changes. Importantly, DOCK2 deficiency also attenuated bleomycin-induced pulmonary fibrosis and α-SMA expression. Taken together, our study demonstrates a novel role of DOCK2 in pulmonary fibrosis by modulating FMT and suggests that targeting DOCK2 may present a potential therapeutic strategy for the prevention or treatment of IPF.

State-of-the-Art Review on Myelofibrosis Therapies

Myelofibrosis (MF) is a BCR-ABL1-negative myeloproliferative neoplasm characterized by anemia, extramedullary hematopoiesis, bone marrow fibrosis, splenomegaly, constitutional symptoms and acute myeloid leukemia progression. Currently, allogeneic haematopoietic stem cell transplantation (AHSCT) therapy is the only curative option for MF patients. However, AHSCT is strictly limited due to the high rates of morbidity and mortality. Janus kinase 2 (JAK2) inhibitor Ruxolitinib is the first-line treatment for intermediate-II or high-risk MF patients with splenomegaly and constitutional symptoms, but most MF patients develop resistance or intolerance to Ruxolitinib. Therefore, MF treatment is a challenge for the medical community. This review summarizes 3 investigated directions for MF therapy: monotherapies of JAK inhibitors, monotherapies of non-JAK targeted agents, combination therapies of Ruxolitinib and other agents. We emphasize combination of Ruxolitinib and other agents is a promising strategy.

PD-L1 mediates lung fibroblast to myofibroblast transition through Smad3 and β-catenin signaling pathways

Programmed death ligand-1 (PD-L1) is an immune checkpoint protein that has been linked with idiopathic pulmonary fibrosis (IPF) and fibroblast to myofibroblast transition (FMT). However, it remains largely unclear how PD-L1 mediates this process. We found significantly increased PD-L1 in the lungs of idiopathic pulmonary fibrosis patients and mice with pulmonary fibrosis induced by bleomycin and TGF-β. In primary human lung fibroblasts (HLFs), TGF-β induced PD-L1 expression that is dependent on both Smad3 and p38 pathways. PD-L1 knockdown using siRNA significantly attenuated TGF-β-induced expression of myofibroblast markers α-SMA, collagen-1, and fibronectin in normal and IPF HLFs. Further, we found that PD-L1 interacts with Smad3, and TGF-β induces their interaction. Interestingly, PD-L1 knockdown reduced α-SMA reporter activity induced by TGF-β in HLFs, suggesting that PD-L1 might act as a co-factor of Smad3 to promote target gene expression. TGF-β treatment also phosphorylates GSK3β and upregulates β-catenin protein levels. Inhibiting β-catenin signaling with the pharmaceutical inhibitor ICG001 significantly attenuated TGF-β-induced FMT. PD-L1 knockdown also attenuated TGF-β-induced GSK3β phosphorylation/inhibition and β-catenin upregulation, implicating GSK3β/β-catenin signaling in PD-L1-mediated FMT. Collectively, our findings demonstrate that fibroblast PD-L1 may promote pulmonary fibrosis through both Smad3 and β-catenin signaling and may represent a novel interventional target for IPF.

Glycogen Synthase Kinase 3β Involvement in Neuroinflammation and Neurodegenerative Diseases

BACKGROUND

GSK-3β activity has been strictly related to neuroinflammation and neurodegeneration. Alzheimer's disease is the most studied neurodegenerative disease, but GSK-3β seems to be involved in almost all neurodegenerative diseases including Parkinson's disease, amyotrophic lateral sclerosis, frontotemporal dementia, Huntington's disease and the autoimmune disease multiple sclerosis.

OBJECTIVE

The aim of this review is to help researchers both working on this research topic or not to have a comprehensive overview on GSK-3β in the context of neuroinflammation and neurodegeneration.

METHOD

Literature has been searched using PubMed and SciFinder databases by inserting specific keywords. A total of more than 500 articles have been discussed.

RESULTS

First of all, the structure and regulation of the kinase were briefly discussed and then, specific GSK-3β implications in neuroinflammation and neurodegenerative diseases were illustrated also with the help of figures, to conclude with a comprehensive overview on the most important GSK-3β and multitarget inhibitors. For all discussed compounds, the structure and IC50 values at the target kinase have been reported.

CONCLUSION

GSK-3β is involved in several signaling pathways both in neurons as well as in glial cells and immune cells. The fine regulation and interconnection of all these pathways are at the base of the rationale use of GSK-3β inhibitors in neuroinflammation and neurodegeneration. In fact, some compounds are now under clinical trials. Despite this, pharmacodynamic and ADME/Tox profiles of the compounds were often not fully characterized and this is deleterious in such a complex system.

Dedicator of Cytokinesis 2 (DOCK2) Deficiency Attenuates Lung Injury Associated with Chronic High-Fat and High-Fructose Diet-Induced Obesity

Obesity is a major risk factor for lung disease development. However, little is known about the impact of chronic high-fat and high-fructose (HFHF) diet-induced obesity on lung inflammation and subsequent pulmonary fibrosis. Herein we hypothesized that dedicator of cytokinesis 2 (DOCK2) promotes a proinflammatory phenotype of lung fibroblasts (LFs) to elicit lung injury and fibrosis in chronic HFHF diet-induced obesity. An HFHF diet for 20 weeks induced lung inflammation and profibrotic changes in wild-type C57BL/6 mice. CD68 and monocyte chemoattractant protein-1 (MCP-1) expression were notably increased in the lungs of wild-type mice fed an HFHF diet. An HFHF diet further increased lung DOCK2 expression that co-localized with fibroblast-specific protein 1, suggesting a role of DOCK2 in regulating proinflammatory phenotype of LFs. Importantly, DOCK2 knockout protected mice from lung inflammation and fibrosis induced by a HFHF diet. In primary human LFs, tumor necrosis factor-α (TNF-α) and IL-1β induced DOCK2 expression concurrent with MCP-1, IL-6, and matrix metallopeptidase 2. DOCK2 knockdown suppressed TNF-α-induced expression of these molecules and activation of phosphatidylinositol 3-kinase/AKT and NF-κB signaling pathways, suggesting a mechanism of DOCK2-mediated proinflammatory and profibrotic changes in human LFs. Taken together, these findings reveal a previously unrecognized role of DOCK2 in regulating proinflammatory phenotype of LFs, potentiation of lung inflammation, and pulmonary fibrosis in chronic HFHF diet-caused obesity.

Update on Novel Targeted Therapy for Pleural Organization and Fibrosis

Pleural injury and subsequent loculation is characterized by acute injury, sustained inflammation and, when severe, pathologic tissue reorganization. While fibrin deposition is a normal part of the injury response, disordered fibrin turnover can promote pleural loculation and, when unresolved, fibrosis of the affected area. Within this review, we present a brief discussion of the current IPFT therapies, including scuPA, for the treatment of pathologic fibrin deposition and empyema. We also discuss endogenously expressed PAI-1 and how it may affect the efficacy of IPFT therapies. We further delineate the role of pleural mesothelial cells in the progression of pleural injury and subsequent pleural remodeling resulting from matrix deposition. We also describe how pleural mesothelial cells promote pleural fibrosis as myofibroblasts via mesomesenchymal transition. Finally, we discuss novel therapeutic targets which focus on blocking and/or reversing the myofibroblast differentiation of pleural mesothelial cells for the treatment of pleural fibrosis.

The Effect of CHIR 99021, a Glycogen Synthase Kinase-3β Inhibitor, on Transforming Growth Factor β-Induced Tenon Fibrosis

Purpose

This study investigated the effect of glycogen synthase kinase-3β (GSK-3β) inhibition on the fibrosis of human Tenon's fibroblasts (HTFs) induced by transforming growth factor-β (TGF-β).

Methods

Quantitative real-time PCR and Western blot analyses were performed to determine the expression levels of molecules associated with the fibrosis of HTFs by TGF-β (fibronectin, collagen Iα, and α-smooth muscle actin) and GSK-3β. The levels of phosphorylated Smad2 and Smad3 were also analyzed in the presence of the GSK-3β inhibitor CHIR 99021. The wound healing assay was performed to determine the effect of CHIR 99021 on the migration of HTFs. All experiments were conducted using primary cultured HTFs or human tenon tissues obtained from normal subjects and patients with glaucoma.

Results

Treatment with TGF-β resulted in an increase in the levels of molecules associated with the fibrosis of HTFs. The expression levels of these molecules were higher in the tenon tissues obtained from patients with glaucoma than those from normal subjects. When the HTFs were treated with TGF-β, a significant increase in the active form of GSK-3β (Y216) was observed. A significant decrease in the active form of GSK-3β and molecules associated with fibrosis by TGF-β was noted in HTFs treated with CHIR 99021. CHIR 99021 treatment reduced the phosphorylated Smad2/Smad2 and phosphorylated Smad3/Smad3 ratios in HTFs and attenuated HTF migration.

Conclusions

Our results demonstrated the effect of GSK-3β inhibition on the regulation of TGF-β–mediated fibrosis of HTFs, suggesting GSK-3β to be a potential target for maintaining bleb function after glaucoma filtration surgery.

TGF-β regulation of the uPA/uPAR axis modulates mesothelial-mesenchymal transition (MesoMT)

Pleural fibrosis (PF) is a chronic and progressive lung disease which affects approximately 30,000 people per year in the United States. Injury and sustained inflammation of the pleural space can result in PF, restricting lung expansion and impairing oxygen exchange. During the progression of pleural injury, normal pleural mesothelial cells (PMCs) undergo a transition, termed mesothelial mesenchymal transition (MesoMT). While multiple components of the fibrinolytic pathway have been investigated in pleural remodeling and PF, the role of the urokinase type plasminogen activator receptor (uPAR) is unknown. We found that uPAR is robustly expressed by pleural mesothelial cells in PF. Downregulation of uPAR by siRNA blocked TGF-β mediated MesoMT. TGF-β was also found to significantly induce uPA expression in PMCs undergoing MesoMT. Like uPAR, uPA downregulation blocked TGF-β mediated MesoMT. Further, uPAR is critical for uPA mediated MesoMT. LRP1 downregulation likewise blunted TGF-β mediated MesoMT. These findings are consistent with in vivo analyses, which showed that uPAR knockout mice were protected from S. pneumoniae-mediated decrements in lung function and restriction. Histological assessments of pleural fibrosis including pleural thickening and α-SMA expression were likewise reduced in uPAR knockout mice compared to WT mice. These studies strongly support the concept that uPAR targeting strategies could be beneficial for the treatment of PF.

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

Simple Summary

Glycogen synthase kinase-3 beta is a protein kinase implicated in the promotion and development of various cancers, including pancreatic cancer. In cell culture and animal studies, drugs targeting the inhibition of this protein show treatment potential in pancreatic cancer. Studies show targeting this protein for treatment may overcome resistance to conventional chemotherapy in pancreatic tumors. Early-stage clinical trials are currently studying small molecule inhibitors targeting glycogen synthase kinase-3 beta and interim results show favorable results. Recent studies also suggest that targeting this protein will create synergy with immunotherapy, such as checkpoint inhibitors. Future studies should aim to study new combination treatments involving glycogen synthase kinase-3 beta targeting drugs with chemotherapy and immunotherapy in pancreatic cancer.

Abstract

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.

Chelerythrine Ameliorates Pulmonary Fibrosis via Activating the Nrf2/ARE Signaling Pathway

Chelerythrine (CHE) is a natural benzophenanthridine alkaloid, which has shown its anti-fibrosis activity in kidney and liver, while the impact of CHE in pulmonary fibrosis is still unclear. This study is developed to explore the impact and mechanism of CHE in pulmonary fibrosis. Pulmonary fibrosis mouse models were established through intratracheal injection of bleomycin (BLM), after which the mice were intraperitoneally injected with CHE (0.375 or 0.75 mg/kg/d) every other day. The mice were sacrificed at the 28th day to collect blood serum, bronchoalveolar lavage fluid (BALF), and pulmonary tissues. Then, the severity of pulmonary fibrosis and the expression of nuclear factor erythroid 2 [NF-E2]-related factor 2 (Nrf2) in the pulmonary tissues were detected. Western blot analysis quantified the expressions of fibronectin and alpha-smooth muscle actin (α-SMA). The levels of 4-hydroxynonenal (4-HNE), glutathione (GSH), superoxide dismutase (SOD), TGF-β and hydroxyproline (HP) in the BALF, and pulmonary tissues were measured. The expression levels of Nrf2 and its downstream genes, hemeoxygenase-1 (HO-1) and NAD (P) H: quinone oxidoreductase (NQO1) were examined. CHE at the concentration of 0.375 or 0.75 mg/kg/d could attenuate pulmonary fibrosis. CHE injection reduced the expression levels of fibronectin, α-SMA, and TGF-β, upregulated the levels of SOD and GSH and decreased the levels of 4-HNE and HP. Also, CHE increased the expressions of Nrf2, HO-1, and NQO1. Treatment of Nrf2/antioxidant response element (ARE) inhibitor could block the Nrf2/ARE signaling pathway, thus perturbing the inhibition of CHE on BLM-stimulated pulmonary fibrosis in mice. CHE alleviates BLM-induced pulmonary fibrosis in mice through activating the Nrf2/ARE pathway to increase the activity of antioxidant enzymes.

Permissive effect of GSK3β on profibrogenic plasticity of renal tubular cells in progressive chronic kidney disease

Renal tubular epithelial cells (TECs) play a key role in renal fibrogenesis. After persistent injuries that are beyond self-healing capacity, TECs will dedifferentiate, undergo growth arrest, convert to profibrogenic phenotypes, and resort to maladaptive plasticity that ultimately results in renal fibrosis. Evidence suggests that glycogen synthase kinase (GSK) 3β is centrally implicated in kidney injury. However, its role in renal fibrogenesis is obscure. Analysis of publicly available kidney transcriptome database demonstrated that patients with progressive chronic kidney disease (CKD) exhibited GSK3β overexpression in renal tubulointerstitium, in which the predefined hallmark gene sets implicated in fibrogenesis were remarkably enriched. In vitro, TGF-β1 treatment augmented GSK3β expression in TECs, concomitant with dedifferentiation, cell cycle arrest at G2/M phase, excessive accumulation of extracellular matrix, and overproduction of profibrotic cytokines like PAI-1 and CTGF. All these profibrogenic phenotypes were largely abrogated by GSK3β inhibitors or by ectopic expression of a dominant-negative mutant of GSK3β but reinforced in cells expressing the constitutively active mutant of GSK3β. Mechanistically, GSK3β suppressed, whereas inhibiting GSK3β facilitated, the activity of cAMP response element-binding protein (CREB), which competes for CREB-binding protein, a transcriptional coactivator essential for TGF-β1/Smad signaling pathway to drive TECs profibrogenic plasticity. In vivo, in mice with folic acid-induced progressive CKD, targeting of GSK3β in renal tubules via genetic ablation or by microdose lithium mitigated the profibrogenic plasticity of TEC, concomitant with attenuated interstitial fibrosis and tubular atrophy. Collectively, GSK3β is likely a pragmatic therapeutic target for averting profibrogenic plasticity of TECs and improving renal fibrosis.

Endothelial Cell Protein C Receptor Deficiency Attenuates Streptococcus pneumoniae-induced Pleural Fibrosis

Streptococcus pneumoniae is the leading cause of hospital community-acquired pneumonia. Patients with pneumococcal pneumonia may develop complicated parapneumonic effusions or empyema that can lead to pleural organization and subsequent fibrosis. The pathogenesis of pleural organization and scarification involves complex interactions between the components of the immune system, coagulation, and fibrinolysis. EPCR (endothelial protein C receptor) is a critical component of the protein C anticoagulant pathway. The present study was performed to evaluate the role of EPCR in the pathogenesis of S. pneumoniae infection-induced pleural thickening and fibrosis. Our studies show that the pleural mesothelium expresses EPCR. Intrapleural instillation of S. pneumoniae impairs lung compliance and lung volume in wild-type and EPCR-overexpressing mice but not in EPCR-deficient mice. Intrapleural S. pneumoniae infection induces pleural thickening in wild-type mice. Pleural thickening is more pronounced in EPCR-overexpressing mice, whereas it is reduced in EPCR-deficient mice. Markers of mesomesenchymal transition are increased in the visceral pleura of S. pneumoniae-infected wild-type and EPCR-overexpressing mice but not in EPCR-deficient mice. The lungs of wild-type and EPCR-overexpressing mice administered intrapleural S. pneumoniae showed increased infiltration of macrophages and neutrophils, which was significantly reduced in EPCR-deficient mice. An analysis of bacterial burden in the pleural lavage, the lungs, and blood revealed a significantly lower bacterial burden in EPCR-deficient mice compared with wild-type and EPCR-overexpressing mice. Overall, our data provide strong evidence that EPCR deficiency protects against S. pneumoniae infection-induced impairment of lung function and pleural remodeling.

Current Clinical Investigations in Myelofibrosis

The US Food and Drug Administration (FDA) approval of Janus kinase 2 inhibitors, ruxolitinib and fedratinib for the treatment of intermediate-2 or high-risk primary or secondary myelofibrosis (MF) has revolutionized the management of MF. Nevertheless, these drugs do not reliably alter the natural history of disease. Burgeoning understanding of the molecular pathogenesis and the bone marrow microenvironment in MF has galvanized the development of targeted therapeutics. This review provides insight into the novel therapies under clinical evaluation.

Challenges and Perspectives for Therapeutic Targeting of Myeloproliferative Neoplasms

Myeloproliferative neoplasms (MPNs) are hematopoietic stem cell disorders with dysregulated myeloid blood cell production and propensity for transformation to acute myeloid leukemia, thrombosis, and bleeding. Acquired mutations in JAK2, MPL, and CALR converge on hyperactivation of Janus kinase 2 (JAK2) signaling as a central feature of MPN. Accordingly, JAK2 inhibitors have held promise for therapeutic targeting. After the JAK1/2 inhibitor ruxolitinib, similar JAK2 inhibitors as fedratinib are entering clinical use. While patients benefit with reduced splenomegaly and symptoms, disease-modifying effects on MPN clone size and clonal evolution are modest. Importantly, response to ruxolitinib may be lost upon treatment suggesting the MPN clone acquires resistance. Resistance mutations, as seen with other tyrosine kinase inhibitors, have not been described in MPN patients suggesting that functional processes reactivate JAK2 signaling. Compensatory signaling, which bypasses JAK2 inhibition, and other processes contribute to intrinsic resistance of MPN cells restricting efficacy of JAK2 inhibition overall. Combinations of JAK2 inhibition with pegylated interferon-α, a well-established therapy of MPN, B-cell lymphoma 2 inhibition, and others are in clinical development with the potential to enhance therapeutic efficacy. Novel single-agent approaches targeting other molecules than JAK2 are being investigated clinically. Special focus should be placed on myelofibrosis patients with anemia and thrombocytopenia, a delicate patient population at high need for options. The extending range of new treatment approaches will increase the therapeutic options for MPN patients. This calls for concomitant improvement of our insight into MPN biology to inform tailored therapeutic strategies for individual MPN patients.

MiRNA-155-5p inhibits epithelium-to-mesenchymal transition (EMT) by targeting GSK-3β during radiation-induced pulmonary fibrosis

Radiation-induced pulmonary fibrosis (RIPF) is a major lung complication in using radiotherapy to treat thoracic diseases. MicroRNAs (miRNAs) are reported to be the therapeutic targets for many diseases. However, the miRNAs involved in the pathogenesis of RIPF are rarely studied as potential therapeutic targets. Alveolar epithelial cells participate in RIPF formation by undergoing epithelial-mesenchymal transition (EMT). Here we demonstrated the critical role of miR-155-5p in radiation-induced EMT and RIPF. Using the previously established EMT cell model, we found that miR-155-5p was significantly down-regulated through high-throughput sequencing. Irradiation could decrease the expression of miR-155-5p in intro and in vivo, and it was inversely correlated to RIPF formation. Ectopic miR-155-5p expression inhibited radiation-induced-EMT in vitro and in vivo. Knockdown of glycogen synthase kinase-3β (GSK-3β), the functional target of miR-155-5p, reversed the induction of EMT and enhanced the phosphorylation of p65, a subunit of NF-κB, which were mediated by the down-regulation of miR-155-5p. Moreover, our finding demonstrated that ectopic miR-155-5p expression alleviated RIPF in mice by the GSK-3β/NF-κB pathway. Thus, radiation downregulates miR-155-5p in alveolar epithelial cells that induces EMT, which contributes to RIPF using GSK-3β/NF-κB pathway. Our observation provides further understanding on the regulation of RIPF and identifies potential therapeutic targets.

Glycogen synthase kinase 3β in tumorigenesis and oncotherapy (Review)

Glycogen synthase kinase 3β (GSK 3β), a multifunctional serine and threonine kinase, plays a critical role in a variety of cellular activities, including signaling transduction, protein and glycogen metabolism, cell proliferation, cell differentiation, and apoptosis. Therefore, aberrant regulation of GSK 3β results in a broad range of human diseases, such as tumors, diabetes, inflammation and neurodegenerative diseases. Accumulating evidence has suggested that GSK 3β is correlated with tumorigenesis and progression. However, GSK 3β is controversial due to its bifacial roles of tumor suppression and activation. In addition, overexpression of GSK 3β is involved in tumor growth, whereas it contributes to the cell sensitivity to chemotherapy. However, the underlying regulatory mechanisms of GSK 3β in tumorigenesis remain obscure and require further in‑depth investigation. In this review, we comprehensively summarize the roles of GSK 3β in tumorigenesis and oncotherapy, and focus on its potentials as an available target in oncotherapy.

Finding a Jill for JAK: Assessing Past, Present, and Future JAK Inhibitor Combination Approaches in Myelofibrosis

Myelofibrosis (MF) is a myeloproliferative neoplasm hallmarked by the upregulation of the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway with associated extramedullary hematopoiesis and a high burden of disease-related symptoms. While JAK inhibitor therapy is central to the management of MF, it is not without limitations. In an effort to improve treatment for MF patients, there have been significant efforts to identify combination strategies that build upon the substantial benefits of JAK inhibition. Early efforts to combine agents with additive therapeutic profiles have given way to rationally designed combinations hoping to demonstrate clinical synergism and modify the underlying disease. In this article, we review the preclinical basis and existing clinical data for JAK inhibitor combination strategies while highlighting emerging strategies of particular interest.

Glycogen synthase kinase-3β: a novel therapeutic target for pancreatic cancer

Introduction: Pancreatic ductal adenocarcinoma (PDAC) is the third leading cause of cancer death in the United States with a single-digit 5-year survival rate despite advances in understanding the genetics and biology of the disease. Glycogen synthase kinase-3α (GSK-3α) and GSK-3β are serine/threonine kinases that localize to the cytoplasm, mitochondria and nucleus. Although they are highly homologous within their kinase domains and phosphorylate an overlapping set of target proteins, genetic studies have shown that GSK-3β regulates the activity of several proteins that promote neoplastic transformation. Significantly, GSK-3β is progressively overexpressed during PDAC development where it participates in tumor progression, survival and chemoresistance. Thus, GSK-3β has become an attractive target for treating PDAC.Areas covered: This review summarizes the mechanisms regulating GSK-3β activity, including upstream translational and post-translational regulation, as well as the downstream targets and their functions in PDAC cell growth, metastasis and chemoresistance.Expert opinion: The activity of GSK-3 kinases are considered cell- and context-specific. In PDAC, oncogenic KRas drives the transcriptional expression of the GSK-3β gene, which has been shown to regulate cancer cell proliferation and survival, as well as resistance to chemotherapy. Thus, the combination of GSK-3 inhibitors with chemotherapeutic drugs could be a promising strategy for PDAC.