Integrin-linked Kinase Research Articles

Modulation of cell migration and cell tracking of the gilthead seabream (Sparus aurata) SAF-1 cells by probiotics

Cell migration is an essential process in immunity and wound healing. The in vitro scratch assay was optimized for the SAF-1 cell line, obtained from gilthead seabream (Sparus aurata) fin. In addition, selected cells from the cell front were tracked for detailed individual cell movement and morphological analysis. Modulation of migration and cell tracking of the SAF-1 cell line by probiotics was evaluated. Cells were cultured and incubated for 24 h with three species of extremophilic yeasts [Yarrowia lipolytica (D1 and N6) and Debaryomyces hansenii (CBS004)] and the bacterium Shewanella putrefaciens (known as SpPdp11) and then scratch and cell tracking assays were performed. The results indicated that the forward velocity was significantly (p < 0.05) increased in SAF-1 cells incubated with CBS004 or SpPdp11. However, cell velocity, cumulative distance and Euclidean distance were only significantly increased in SAF-1 cells incubated with SpPdp11. Furthermore, to increase our understanding of the genes involved in cell movement, the expression profile of ten structural proteins (α-1β tubulin, vinculin, focal adhesion kinase type, alpha-2 integrin, tetraspanin, integrin-linked kinase 1, tensin 3, tensin 4, paxillin, and light chain 2) was studied by real time-PCR. The expression of these genes was modulated as a function of the probiotic tested and the results indicate that CBS004 and SpPdp11 increase the movement of SAF-1 cells.

Integrated Meta-Omics Analysis Unveils the Pathways Modulating Tumorigenesis and Proliferation in High-Grade Meningioma.

Meningioma, a primary brain tumor, is commonly encountered and accounts for 39% of overall CNS tumors. Despite significant progress in clinical research, conventional surgical and clinical interventions remain the primary treatment options for meningioma. Several proteomics and transcriptomics studies have identified potential markers and altered biological pathways; however, comprehensive exploration and data integration can help to achieve an in-depth understanding of the altered pathobiology. This study applied integrated meta-analysis strategies to proteomic and transcriptomic datasets comprising 48 tissue samples, identifying around 1832 common genes/proteins to explore the underlying mechanism in high-grade meningioma tumorigenesis. The in silico pathway analysis indicated the roles of extracellular matrix organization (EMO) and integrin binding cascades in regulating the apoptosis, angiogenesis, and proliferation responsible for the pathobiology. Subsequently, the expression of pathway components was validated in an independent cohort of 32 fresh frozen tissue samples using multiple reaction monitoring (MRM), confirming their expression in high-grade meningioma. Furthermore, proteome-level changes in EMO and integrin cell surface interactions were investigated in a high-grade meningioma (IOMM-Lee) cell line by inhibiting integrin-linked kinase (ILK). Inhibition of ILK by administrating Cpd22 demonstrated an anti-proliferative effect, inducing apoptosis and downregulating proteins associated with proliferation and metastasis, which provides mechanistic insight into the disease pathophysiology.

Extracellular SOD modulates canonical TNFα signaling and α5β1 integrin transactivation in vascular smooth muscle cells

TNFα activates NADPH oxidase 1 (Nox1) in vascular smooth muscle cells (VSMCs). The extracellular superoxide anion (O2•-) produced is essential for the pro-inflammatory effects of the cytokine but the specific contributions of O2•- to signal transduction remain obscure. Extracellular superoxide dismutase (ecSOD, SOD3 gene) is a secreted protein that binds to cell surface heparin sulfate proteoglycans or to Fibulin-5 (Fib-5, FBLN5 gene), an extracellular matrix protein that also associates with elastin and integrins. ecSOD converts O2•- to hydrogen peroxide (H2O2) which prevents NO• inactivation, limits generation of hydroxyl radical (OH•), and creates high local concentrations of H2O2. We hypothesized that ecSOD modifies TNFα signaling in VSMCs. Knockdown of ecSOD (siSOD3) suppressed downstream TNFα signals including MAPK (JNK and ERK phosphorylation) and NF-κB activation (luciferase reporter and IκB phosphorylation), interleukin-6 (IL-6) secretion, iNOS and VCAM expression, and proliferation (Sulforhodamine B assay, PCNA western blot). These effects were associated with significant reductions in the expression of both Type1 and 2 TNFα receptors. Reduced Fib-5 expression (siFBLN5) similarly impaired NF-κB activation by TNFα, but potentiated FAK phosphorylation at Y925. siSOD3 also increased both resting and TNFα-induced phosphorylation of FAK and of glycogen synthase kinase-3β (GSK3β), a downstream target of integrin linked kinase (ILK). These effects were dependent upon α5β1 integrins and siSOD3 increased resting sulfenylation (oxidation) of both integrin subunits, while preventing TNFα-induced increases in sulfenylation. To determine how ecSOD modified TNFα-induced inflammation in intact blood vessels, mesenteric arteries from VSMC-specific ecSOD knockout (KO) mice were exposed to TNFα (10 ng/ml) in culture for 48 h. Relaxation to acetylcholine and sodium nitroprusside was impaired in WT but not ecSOD KO vessels. Thus, ecSOD association with Fib-5 supports pro-inflammatory TNFα signaling while tonically inhibiting α5β1 integrin activation.

Phosphorylation-mediated regulation of integrin-linked kinase 5 by purinoreceptor P2K2

ABSTRACT Extracellular ATP (eATP) in plants plays a crucial role as a ligand for purinoreceptors, mediating purinergic signaling and regulating diverse biological functions, including responses to abiotic and biotic stresses. DORN1/P2K1 (LecRK I.9) was the first identified plant purinoreceptor. P2K2 (LecRK I.5) was subsequently identified as an additional plant purinoreceptor and shown to directly interact with P2K1. Recently, we reported that P2K1 interacts with Integrin-linked kinase 5 (ILK5), a Raf-like MAPKKK protein, and phosphorylates ILK5 to regulate purinergic signaling in relation to plant innate immunity. Here, we report that P2K2 also interacts with the ILK5 protein in planta. Furthermore, we demonstrate that P2K2 phosphorylates ILK5 in the presence of [γ-32P] ATP, similar to P2K1. However, unlike P2K1, P2K2 exhibits strong phosphorylation even when the Serine 192 residue of ILK5 is mutated to Alanine (ILK5S192A), suggesting the possibility of phosphorylation of other residues to fully regulate ILK5 protein function.

Multi-omics profiling reveals cellular pathways and functions regulated by ALDH1B1 in colon cancer cells

Colon cancer is the third leading cause of cancer death globally. Although early screenings and advances in treatments have reduced mortality since 1970, identification of novel targets for therapeutic intervention is needed to address tumor heterogeneity and recurrence. Previous work identified aldehyde dehydrogenase 1B1 (ALDH1B1) as a critical factor in colon tumorigenesis. To investigate further, we utilized a human colon adenocarcinoma cell line (SW480) in which the ALDH1B1 protein expression has been knocked down by 80% via shRNA. Through multi-omics (transcriptomics, proteomics, and untargeted metabolomics) analysis, we identified the impact of ALDH1B1 knocking down (KD) on molecular signatures in colon cancer cells. Suppression of ALDH1B1 expression resulted in 357 differentially expressed genes (DEGs), 191 differentially expressed proteins (DEPs) and 891 differentially altered metabolites (DAMs). Functional annotation and enrichment analyses revealed that: (1) DEGs were enriched in integrin-linked kinase (ILK) signaling and growth and development pathways; (2) DEPs were mainly involved in apoptosis signaling and cellular stress response pathways; and (3) DAMs were associated with biosynthesis, intercellular and second messenger signaling. Collectively, the present study provides new molecular information associated with the cellular functions of ALDH1B1, which helps to direct future investigation of colon cancer.

Cannabidiol alleviates perfluorooctane sulfonate-induced macrophage extracellular trap mediate inflammation and fibrosis in mice liver

As a new type of persistent organic pollutant, perfluorooctane sulphonate (PFOS) has received extensive attention worldwide. Cannabidiol (CBD) is a non-psychoactive natural cannabinoid extract that has been proved to have antioxidation, regulation of inflammation and other functions. However, the effects of PFOS on liver injury and whether CBD can alleviate PFOS-induced liver injury are still unclear. Therefore, in this study, we used CBD (10 mg/kg) and/or PFOS (5 mg/kg) to intraperitoneally inject mice for 30 days. We found that PFOS exposure led to inflammatory infiltration in the liver of mice, increased the formation of macrophage extracellular trap (MET), and promoted fibrosis. In vitro, we established a coculture system of RAW264.7, AML12 and LX-2 cells, and treated them with CBD (10 μM) and/or PFOS (200 μM). The results showed that PFOS could also induce the expression of MET, inflammation and fibrosis marker genes in vitro. Coiled-coil domain containing protein 25 (CCD25), as a MET-DNA sensor, was used to investigate its ability to regulate inflammation and fibrosis, we knocked down CCDC25 and its downstream proteins (integrin-linked kinase, ILK) by siRNA technology, and used QNZ to inhibit NF-κB pathway. The results showed that the knockdown of CCDC25 and ILK and the inhibition of NF-κB pathway could inhibit MET-induced inflammation and fibrosis marker gene expression. In summary, we found that PFOS-induced MET can promote inflammation and fibrosis through the CCDC25-ILK-NF-κB signaling axis, while the treatment of CBD showed a protective effect, and it is proved by Macromolecular docking that this protective effect is achieved by combining CBD with peptidylarginine deiminase 4 (PAD4) to alleviate the release of MET. Therefore, regulating the formation of MET and the CCDC25-ILK-NF-κB signaling axis is an innovative treatment option that can effectively reduce hepatotoxicity. Our study reveals the mechanism of PFOS-induced hepatotoxicity and provides promising insights into the protective role of CBD in this process.

Glutaredoxin 2 protects lens epithelial cells from epithelial-mesenchymal transition by suppressing mitochondrial oxidative stress-related upregulation of integrin-linked kinase

Glutaredoxin 2 (Grx2), a mitochondrial glutathione-dependent oxidoreductase, is crucial for maintaining redox homeostasis and cellular functions in the lens. The oxidative stress-induced epithelial-mesenchymal transition (EMT) of lens epithelial cells (LECs) is related to posterior capsule opacification. In this study, we investigated the effects of Grx2 on oxidative stress-induced EMT in LECs during posterior capsule opacification. We found that Grx2 expression was substantially decreased during the EMT of LECs and in a mouse model of cataract surgery. Deletion of Grx2 aggravated the generation of reactive oxygen species, including those that are mitochondria-derived, and promoted the proliferation and EMT of the LECs. This was reversed by Grx2 overexpression. In vivo, proteomic liquid chromatography-mass spectrometry analysis showed that integrin-linked kinase (ILK) was significantly upregulated in the lens posterior capsule of a Grx2 knockout (KO) mouse model. Compared with that of the wild-type group, the expression of ILK and EMT markers was increased in the Grx2 KO group which was reversed in the Grx2 knock-in group. Inhibition of ILK partially blocked Grx2 knockdown-induced EMT and prevented the increased phosphorylation of Akt and GSK-3β and the nuclear translocation of β-catenin in the Grx2 KO group. Finally, inhibition of the Wnt/β-catenin pathway partially blocked the Grx2 knockdown-induced EMT. In conclusion, we demonstrated that Grx2 protects LECs from oxidative stress-related EMT by regulating the ILK/Akt/GSK-3β axis.

Comparative transcriptome findings reveal the neuroinflammatory network and potential biomarkers to early detection of ischemic stroke

IntroductionIschemic stroke accounts for 70–80% of all stroke cases, leading to over two million people dying every year. Poor diagnosis and late detection are the major causes of the high death and disability rate.MethodsIn the present study, we used the middle cerebral artery occlusion (MCAO) rat model and applied comparative transcriptomic analysis, followed by a systematic advanced bioinformatic analysis, including gene ontology enrichment analysis and Ingenuity Pathway Analysis (IPA). We aimed to identify novel biomarkers for the early detection of ischemic stroke. In addition, we aimed to delineate the molecular mechanisms underlying the development of ischemic stroke, in which we hoped to identify novel therapeutic targets for treating ischemic stroke.ResultsIn the comparative transcriptomic analysis, we identified 2657 differentially expressed genes (DEGs) in the brain tissue of the MCAO model. The gene enrichment analysis highlighted the importance of these DEGs in oxygen regulation, neural functions, and inflammatory and immune responses. We identified the elevation of angiopoietin-2 and leptin receptor as potential novel biomarkers for early detection of ischemic stroke. Furthermore, the result of IPA suggested targeting the inflammasome pathway, integrin-linked kinase signaling pathway, and Th1 signaling pathway for treating ischemic stroke.ConclusionThe results of the present study provide novel insight into the biomarkers and therapeutic targets as potential treatments of ischemic stroke.

Proteomics profiling and lysine malonylation analysis in primary Sjogren’s syndrome

Primary Sjogren's Syndrome (pSS) is a chronic autoimmune disease, with unclear pathogenies. Lysine-malonylation (Kmal) as a novel post-translational modification (PTMs) was found associated with metabolic, immune, and inflammatory processes. For purpose of investigating the proteomic profile and functions of kmal in pSS, liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based analysis and bioinformatics analysis are performed based on twenty-eight pSS patients versus twenty-seven healthy controls (HCs). A total of 331 down-regulated proteins and 289 up-regulated proteins are observed in differentially expressed proteins (DEPs) of pSS. We discover the expression of transforming growth factor beta-1 (TGFB1) and CD40 ligand downregulate which enriches in the inflammatory associated pathway. Expression of signal transducer and activator of transcription 1-alpha/beta (STAT1) show upregulation and enrich in type I interferon signaling pathway and IL-27-mediated signaling pathway. In differentially malonylated proteins (DMPs) of pSS, we identify 3 proteins are down-regulated in 7 sites and 18 proteins are up-regulated in 19 sites. Expression of malonylated integrin-linked kinase (ILK) significantly enrich in the focal adhesion pathway. Together, our data provide evidence that downregulation of TGFB1 and CD40LG play a critical role in the inflammatory process of pSS, while upregulation of STAT1 may be associated with IL-27 immunity and pSS immune dysfunction. Moreover, kmal modification at the kinase domain of ILK may destabilize ILK that thus contributing to pSS pathogenies by regulating the focal adhesion pathway. SignificanceOur research offered the first characterization of Kmal, a newly identified form of lysine acylation in pSS, as well as proteomic data on individuals with pSS. In this study, we found that several key DMPs were associated with focal adhesion pathway, which contributes to the development of pSS. The present results provide an informative dataset for the future exploration of Kmal in pSS.

Upregulation of integrin‑linked kinase enhances tumor progression in gemcitabine‑resistant pancreatic cancer.

Pancreatic cancer (PaCa) tends to be resistant to chemotherapy and is associated with a very poor prognosis. It has been previously reported by the authors that integrin‑linked kinase (ILK) is a prognostic factor in PaCa. ILK expression was examined in a newly established gemcitabine (Gem)‑resistant (Gem‑R) PaCa cell line and it was demonstrated that ILK expression was upregulated compared with that in Gem‑sensitive (Gem‑S) cells. In the present study, the effects of increased ILK expression in Gem‑R PaCa cells were evaluated and it was examined whether compound22 (Cpd22), an ILK inhibitor, exerted antitumor effects not only in Gem‑S cells but also in Gem‑R cells. Reverse transcription‑quantitative polymerase chain reaction and western blotting revealed that ILK expression was higher in Gem‑R PaCa cells than in Gem‑S PaCa cells. Cpd22 inhibited the growth of PaCa cells in a concentration‑dependent manner. Cpd22 also inhibited the growth of Gem‑R PaCa cells. The invasive and angiogenic potential of Gem‑R PaCa cells was enhanced compared with that in Gem‑S cells; however, ILK small interfering RNA and Cpd22 treatment suppressed this enhancement of invasive potential compared with that in Gem‑S cells. The addition of Cpd22 to Gem also improved the sensitivity of Gem‑R cell lines to Gem. Furthermore, enhanced Akt signaling was associated with increased malignancy in Gem‑R cell lines. In conclusion, ILK was upregulated with resistance and may be involved in tumor angiogenesis, invasive potential, and chemotherapy resistance, which were all suppressed by Cpd22 treatment. Thus, Cpd22 may be a novel therapeutic agent for the treatment of PaCa.

Extracellular vesicle-packaged ILK from mesothelial cells promotes fibroblast activation in peritoneal fibrosis.

Progressive peritoneal fibrosis and the loss of peritoneal function often emerged in patients undergoing long-term peritoneal dialysis (PD), resulting in PD therapy failure. Varieties of cell-cell communications among peritoneal cells play a significant role in peritoneal fibrogenesis. Extracellular vesicles (EVs) have been confirmed to involve in intercellular communication by transmitting proteins, nucleic acids or lipids. However, their roles and functional mechanisms in peritoneal fibrosis remain to be determined. Using integrative analysis of EV proteomics and single-cell RNA sequencing, we characterized the EVs isolated from PD patient's effluent and revealed that mesothelial cells are the main source of EVs in PD effluent. We demonstrated that transforming growth factor-β1 (TGF-β1) can substitute for PD fluid to stimulate mesothelial cells releasing EVs, which in turn promoted fibroblast activation and peritoneal fibrogenesis. Blockade of EVs secretion by GW4869 or Rab27a knockdown markedly suppressed PD-induced fibroblast activation and peritoneal fibrosis. Mechanistically, injured mesothelial cells produced EVs containing high level of integrin-linked kinase (ILK), which was delivered to fibroblast and activated them via p38 MAPK signalling pathway. Clinically, the expression of ILK was up-regulated in fibrotic peritoneum of patients undergoing long-term PD. The percentage of ILK positive EVs in PD effluent correlated with peritoneal dysfunction and the degree of peritoneal damage. Our study highlights that peritoneal EVs mediate communications between mesothelial cells and fibroblasts to initiate peritoneal fibrogenesis. Targeting EVs or ILK could provide a novel therapeutic strategy to combat peritoneal fibrosis.

Combination Effects of Integrin-linked Kinase and Abelson Kinase Inhibition on Aberrant Mitosis and Cell Death in Glioblastoma Cells.

In cancer cells, inhibition of integrin-linked kinase (ILK) increases centrosome declustering causing mitotic arrest and cell death. Yet, not all cancer cells are susceptible to anti-ILK treatment alone. We investigate a combination drug strategy targeting ILK and another oncogenic kinase, Abelson kinase (ABL). Drug-concentration viability assays (i.e., MTT assays) indicate that ILK and ABL inhibitors in combination decreased the viability of glioblastoma cells over the ILK drug QLT-0267 alone. Combination strategies also increased aberrant mitoses and cell death over QLT-0267 alone. This was evident from an increase in mitotic arrest, apoptosis and a sub-G1 peak following FAC analysis. In vitro, ILK and ABL localized to the centrosome and the putative ILK kinase domain was important for this localization. Increased levels of cytosolic ABL are associated with its transformative abilities. ILK inhibitor effects on survival correlated with its ability to decrease cytosolic ABL levels and inhibit ABL's localization to mitotic centrosomes in glioblastoma cells. ILK inhibitor effects on ABL's centrosomal localization were reversed by the proteasomal inhibitor MG132 (a drug that inhibits ABL degradation). These results indicate that ILK regulates ABL at mitotic centrosomes and that combination treatments targeting ILK and ABL are more effective then QLT-0267 alone at decreasing the survival of dividing glioblastoma cells.

Myocardin-related transcription factor contributes to renal fibrosis through the regulation of extracellular microenvironment surrounding fibroblasts.

Fibroblast accumulation and extracellular matrix (ECM) deposition are common critical steps for the progression of organ fibrosis, but the precise molecular mechanisms remain to be fully investigated. We have previously demonstrated that lysophosphatidic acid contributes to organ fibrosis through the production of connective tissue growth factor (CTGF) via actin cytoskeleton-dependent signaling, myocardin-related transcription factor family (MRTF) consisting of MRTF-A and MRTF-B-serum response factor (SRF) pathway. In this study, we investigated the role of the MRTF-SRF pathway in the development of renal fibrosis, focusing on the regulation of ECM-focal adhesions (FA) in renal fibroblasts. Here we showed that both MRTF-A and -B were required for the expressions of ECM-related molecules such as lysyl oxidase family members, type I procollagen and fibronectin in response to transforming growth factor (TGF)-β1 . TGF-β1 -MRTF-SRF pathway induced the expressions of various components of FA such as integrin α subunits (αv , α2 , α11 ) and β subunits (β1 , β3 , β5 ) as well as integrin-linked kinase (ILK). On the other hand, the blockade of ILK suppressed TGF-β1 -induced MRTF-SRF transcriptional activity, indicating a mutual relationship between MRTF-SRF and FA. Myofibroblast differentiation along with CTGF expression was also dependent on MRTF-SRF and FA components. Finally, global MRTF-A deficient and inducible fibroblast-specific MRTF-B deficient mice (MRTF-AKO BiFBKO mice) are protected from renal fibrosis with adenine administration. Renal expressions of ECM-FA components and CTGF as well as myofibroblast accumulation were suppressed in MRTF-AKO BiFBKO mice. These results suggest that the MRTF-SRF pathway might be a therapeutic target for renal fibrosis through the regulation of components forming ECM-FA in fibroblasts.

Targeting the YAP/TAZ mechanotransducers in solid tumour therapeutics.

Targeting the YAP/TAZ mechanotransducers in solid tumour therapeutics.

Interommatidial cells build a tensile collagen network during Drosophila retinal morphogenesis

Drosophila compound eye morphogenesis transforms a simple epithelium into an approximate hollow hemisphere comprised of ∼700 ommatidia, packed as tapering hexagonal prisms between a rigid external array of cuticular lenses and a parallel, rigid internal floor, the fenestrated membrane (FM). Critical to vision, photosensory rhabdomeres are sprung between these two surfaces, grading their length and shape accurately across the eye and aligning them to the optical axis. Using fluorescently tagged collagen and laminin, we show that that the FM assembles sequentially, emerging in the larval eye disc in the wake of the morphogenetic furrow as the original collagen-containing basement membrane (BM) separates from the epithelial floor and is replaced by a new, laminin-rich BM, which advances around axon bundles of newly differentiated photoreceptors as they exit the retina, forming fenestrae in this new, laminin-rich BM. In mid-pupal development, the interommatidial cells (IOCs) autonomously deposit collagen at fenestrae, forming rigid, tension-resisting grommets. In turn, stress fibers assemble in the IOC basal endfeet, where they contact grommets at anchorages mediated by integrin linked kinase (ILK). The hexagonal network of IOC endfeet tiling the retinal floor couples nearest-neighbor grommets into a supracellular tri-axial tension network. Late in pupal development, IOC stress fiber contraction folds pliable BM into a hexagonal grid of collagen-stiffened ridges, concomitantly decreasing the area of convex FM and applying essential morphogenetic longitudinal tension to rapidly growing rhabdomeres. Together, our results reveal an orderly program of sequential assembly and activation of a supramolecular tensile network that governs Drosophila retinal morphogenesis.

Integrins in GtoPdb v.2023.1

Integrins are unusual signalling proteins that function to signal both from the extracellular environment into the cell, but also from the cytoplasm to the external of the cell. The intracellular signalling cascades associated with integrin activation focus on protein kinase activities, such as focal adhesion kinase and Src. Based on this association between extracellular signals and intracellular protein kinase activity, we have chosen to include integrins in the 'Catalytic receptors' section of the database until more stringent criteria from NC-IUPHAR allows precise definition of their classification.Integrins are heterodimeric entities, composed of α and β subunits, each 1TM proteins, which bind components of the extracellular matrix or counter-receptors expressed on other cells. One class of integrin contains an inserted domain (I) in its α subunit, and if present (in α1, α2, α10, α11, αD, αE, αL, αM and αX), this I domain contains the ligand binding site. All β subunits possess a similar I-like domain, which has the capacity to bind ligand, often recognising the RGD motif. The presence of an α subunit I domain precludes ligand binding through the β subunit. Integrins provide a link between ligand and the actin cytoskeleton (through typically short intracellular domains). Integrins bind several divalent cations, including a Mg2+ ion in the I or I-like domain that is essential for ligand binding. Other cation binding sites may regulate integrin activity or stabilise the 3D structure. Integrins regulate the activity of particular protein kinases, including focal adhesion kinase and integrin-linked kinase. Cellular activation regulates integrin ligand affinity via inside-out signalling and ligand binding to integrins can regulate cellular activity via outside-in signalling.Several drugs that target integrins are in clinical use including: (1) abciximab (αIIbβ3) for short term prevention of coronary thrombosis, (2) vedolizumab (α4β7) to reduce gastrointestinal inflammation, and (3) natalizumab (α4β1) in some cases of severe multiple sclerosis.

Abstract 5808: Integrin-linked kinase regulates Wnt transcriptional activity in platinum resistant ovarian cancer stem cells

Abstract Ovarian cancer (OC) is the most lethal gynecological cancer, characterized by chemo-resistance and fatal tumor recurrence after primary treatment. The metastatic progression is mediated by exfoliation of tumor cells into the peritoneal cavity, the formation of compact OC spheroids, and their implantation onto the overlying peritoneal surface. Spheroid formation is promoted by a change of cell adhesion properties, enhanced secretion of extracellular matrix (ECM) components, such as fibronectin (FN), that stiffen the tumor stroma, promote the aberrant activation of integrins, and recruit the adaptor protein integrin-linked kinase (ILK). ILK drives cytoskeletal assembly and modulates key processes, including survival, invasion, and stemness. However, the functional role of ILK in chemoresistance of ovarian cancer stem cells (OCSCs) remains incompletely understood. We tested the hypothesis that the formation of FN-integrin complexes at the cell membrane promotes survival of OCSCs and supports OC spheroid formation by activating ILK and downstream oncogenic signaling. In OCSCs compared with non-CSC, ILK, FN, and integrin β1 mRNA expression levels were increased (P&amp;lt;0.001) and further enriched in OC spheroids compared with monolayers (P&amp;lt;0.01). ILK blockade with the specific inhibitor cpd-22 suppressed spheroid proliferation and tumor initiating capacity in xenograft mouse model. Furthermore, key oncogenic signaling pathways, in particular decreased β-catenin signaling essential to sustaining cancer cell stemness, were altered in OC spheroids treated with cpd-22. Of the genes examined, expression of Wnt receptor Frizzled 7 (Fzd7) was the mostly highly downregulated in OC spheroids treated with cpd-22, indicating a direct correlation between ILK activation and Wnt signaling. By using co-immunoprecipitation and proximity ligation assay, we demonstrated that ILK co-localizes with Fzd7 in OC spheroids. Mechanistically, treatment of OC spheroids with the combination of carboplatin and ILK-Fzd7 blockade decreased β-catenin signaling, inhibited phospho-Akt at Ser473 and increased levels of cleaved-caspase-3 compared to single agent alone, resulting in apoptosis. By regulating β-catenin signaling, Fzd7 expression and ILK activation are essential for OCSCs survival. Targeting Fzd7-ILK clusters may represent a new therapeutic approach to eradicate OCSC and ultimately improve patient outcomes. Citation Format: Rula Atwani, Virginie Lazar, George Earl Sandusky, Salvatore Condello. Integrin-linked kinase regulates Wnt transcriptional activity in platinum resistant ovarian cancer stem cells. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5808.

α1A Adrenoreceptor blockade attenuates myocardial infarction by modulating the integrin-linked kinase/TGF-β/Smad signaling pathways

BackgroundMyocardial infarction (MI) is considered a public health problem. According to the World Health Organization, MI is a leading cause of death and comorbidities worldwide. Activation of the α1A adrenergic receptor is a contributing factor to the development of MI. Tamsulosin, an α1A adrenergic blocker, has gained wide popularity as a medication for the treatment of benign prostatic hyperplasia. Limited evidence from previous studies has revealed the potential cardioprotective effects of tamsulosin, as its inhibitory effect on the α1A adrenoceptor protects the heart by acting on the smooth muscle of blood vessels, which results in hypotension; however, its effect on the infarcted heart is still unclear. The mechanisms of the expected cardioprotective effects mediated by tamsulosin are not yet understood. Transforming growth factor-beta (TGF-β), a mediator of fibrosis, is considered an attractive therapeutic target for remodeling after MI. The role of α1A adrenoceptor inhibition or its relationships with integrin-linked kinase (ILK) and TGF-β/small mothers against decapentaplegic (Smad) signaling pathways in attenuating MI are unclear. The present study was designed to investigate whether tamsulosin attenuates MI by modulating an ILK-related TGF-β/Smad pathway.MethodsTwenty-four adult male Wistar rats were randomly divided into 4 groups: control, ISO, TAM, and ISO + TAM. ISO (150 mg/kg, intraperitoneally) was injected on Days 20 and 21 to induce MI. Tamsulosin (0.8 mg/kg, orally) was administered for 21 days, prior to ISO injection for 2 consecutive days. Heart-to-body weight ratios and cardiac and fibrotic biomarker levels were subsequently determined. ILK, TGF-β1, p-Smad2/3, and collagen III protein expression levels were determined using biomolecular methods.ResultsTamsulosin significantly attenuated the relative heart-to-body weight index (p < 0.5) and creatine kinase-MB level (p < 0.01) compared with those in the ISO control group. While ISO resulted in superoxide anion production and enhanced oxidative damage, tamsulosin significantly prevented this damage through antioxidant defense mechanisms, increasing glutathione and superoxide dismutase levels (p < 0.05) and decreasing lipid peroxide oxidation levels (p < 0.01). The present data revealed that tamsulosin reduced TGF-β/p-Smad2/3 expression and enhanced ILK expression.ConclusionTamsulosin may exert a cardioprotective effect by modulating the ILK-related TGF-β/Smad signaling pathway. Thus, tamsulosin may be a useful therapeutic approach for preventing MI.

Effects and mechanism of astragalus polysaccharide on wound healing of deep partial-thickness burns in rats

Objective: To investigate the effects and mechanism of astragalus polysaccharide (APS) on wound healing of deep partial-thickness burns in rats. Methods: The experimental study method was used. Fifty 7-week-old male Sprague-Dawley rats were divided into normal group, simple burn group, APS group, inhibitor group, and inhibitor+APS group according to the random number table, with 10 rats in each group. Except for normal group, rats in the other 4 groups were inflicted with a deep partial-thickness burn wound on the back. Rats in normal group and simple burn group were intraperitoneally injected with normal saline, and rats in the other three groups were injected with APS and/or integrin-linked kinase (ILK) inhibitor, respectively. After 7 days of injection, the wound healing rate of rats with burns in the four groups was calculated, and the serum content of interferon-γ, interleukin-2 (IL-2), and tumor necrosis factor α (TNF-α) in rats in 5 groups was determined by enzyme-linked immunosorbent assay (ELISA). The normal skin tissue of rats in normal group and wound tissue of rats with burns in the four groups were taken, the water content was determined and the water ratio was calculated, the content of interferon-γ, IL-2, and TNF-α was detected by ELISA, the mRNA expressions of epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), and ILK were detected by real-time fluorescence quantitative reverse transcription polymerase chain reaction, and the protein expressions of ILK, protein kinase B (Akt), phosphorylated Akt (p-Akt), glycogen synthetic kinase-3β (GSK-3β), and phosphorylated GSK-3β (p-GSK-3β) were detected by Western blotting. Data were statistically analyzed with one-way analysis of variance and least significant difference test. Results: After 7 days of injection, the wound healing rate of rats in APS group was (67±5)%, which was significantly higher than (52±4)% in simple burn group and (59±5)% in inhibitor+APS group (with all the P values <0.05). The wound healing rate of rats in inhibitor+APS group was significantly higher than (48±4)% in inhibitor group (P<0.05). After 7 days of injection, compared with those in serum or normal skin tissue of rats in normal group, the serum content of interferon-γ, TNF-α, IL-2 and the water ratio of wound tissue of rats in simple burn group were significantly increased (P<0.05); compared with those in APS group, the serum content of interferon-γ, TNF-α, IL-2 and the water ratio of wound tissue of rats in simple burn group and inhibitor+APS group were significantly increased (P<0.05); compared with those in inhibitor group, the serum content of interferon-γ, TNF-α, IL-2 and the water ratio of wound tissue of rats in inhibitor+APS group were significantly decreased (P<0.05). After 7 days of injection, compared with that in normal skin tissue of rats in normal group, the content of interferon-γ, TNF-α, and IL-2 in wound tissue of rats in simple burn group was significantly increased (P<0.05); compared with that in APS group, the content of interferon-γ, TNF-α, and IL-2 in wound tissue of rats in simple burn group and inhibitor+APS group was significantly increased (P<0.05); compared with that in inhibitor group, the content of interferon-γ, TNF-α, and IL-2 in wound tissue of rats in inhibitor+APS group was significantly decreased (P<0.05). After 7 days of injection, compared with those in normal skin tissue of rats in normal group, the mRNA expressions of EGF, bFGF, ILK and protein expressions of ILK, p-Akt, p-GSK-3β in wound tissue of rats in simple burn group were significantly increased (P<0.05); compared with those in APS group, the mRNA expressions of EGF, bFGF, ILK and protein expressions of ILK, p-Akt, p-GSK-3β in wound tissue of rats in simple burn group and inhibitor+APS group were significantly decreased (P<0.05); compared with those in inhibitor group, the mRNA expressions of EGF, bFGF, ILK and protein expressions of ILK, p-Akt, p-GSK-3β in wound tissue of rats in inhibitor+APS group were significantly increased (P<0.05). There were no statistically significant differences in the protein expressions of Akt and GSK-3β in normal skin tissue of rats in normal group and wound tissue of rats with burns in the four groups (P>0.05). Conclusions: APS can alleviate systemic and local inflammation, alleviate tissue edema, and promote the expressions of healing factors in rats with deep partial-thickness burns, thus to promote the wound healing, possibly by activating ILK/Akt/GSK-3β signaling pathway.

Negative regulation of type I interferon signaling by integrin-linked kinase permits dengue virus replication.

Dengue virus (DENV) infection can induce life-threatening dengue hemorrhagic fever/dengue shock syndrome in infected patients. DENV is a threat to global health due to its growing numbers and incidence of infection in the last 50 years. During infection, DENV expresses ten structural and nonstructural proteins modulating cell responses to benefit viral replication. However, the lack of knowledge regarding the cellular proteins and their functions in enhancing DENV pathogenesis impedes the development of antiviral drugs and therapies against fatal DENV infection. Here, we identified that integrin-linked kinase (ILK) is a novel enhancing factor for DENV infection by suppressing type I interferon (IFN) responses. Mechanistically, ILK binds DENV NS1 and NS3, activates Akt and Erk, and induces NF-κB-driven suppressor of cytokine signaling 3 (SOCS3) expression. Elevated SOCS3 in DENV-infected cells inhibits phosphorylation of STAT1/2 and expression of interferon-stimulated genes (ISGs). Inhibiting ILK, Akt, or Erk activation abrogates SOCS3 expression. In DENV-infected mice, the treatment of an ILK inhibitor significantly reduces viral loads in the brains, disease severity, and mortality rate. Collectively, our results show that ILK is a potential therapeutic target against DENV infection.