Integrin-linked Kinase Signaling Pathway Research Articles

The role of FERMT2 in the tumor microenvironment and immunotherapy in pan-cancer using comprehensive single-cell and bulk sequencing

FERMT2 has been identified as a participant in integrin-linked kinase signaling pathways, influencing epithelial-mesenchymal transition and thereby affecting tumor initiation, progression, and invasion. While the character of FERMT2 in the tumor microenvironment (TME) as well as its implications for immunotherapy remain unclear. Thus, we conducted a comprehensive analysis to assess the prognostic significance of FERMT2 using Kaplan-Meier analysis. In addition, we employed enrichment analysis to uncover potential underlying molecular mechanisms. Using "Immunedeconv" package, we evaluated the immune characteristics of FERMT2 within TME. Furthermore, we determined the expression levels of FERMT2 in various cell types within TME, based on single-cell sequencing data. To confirm the co-expression of FERMT2 and markers of cancer-associated fibroblasts (CAFs), we performed multiplex immunofluorescence staining on tissue paraffin sections across various cancer types. Our analysis disclosed a significant correlation between elevated FERMT2 expression and unfavorable prognosis in specific cancer types. Furthermore, we identified a strong correlation between FERMT2 expression and diverse immune-related factors, including immune checkpoint molecules, immune cell infiltration, microsatellite instability (MSI), and tumor mutational burden (TMB). Additionally, there was a significant correlation between FERMT2 expression and immune-related pathways, particularly those associated with activating, migrating, and promoting the growth of fibroblasts in diverse cancer types. Interestingly, we observed consistent co-expression of FERMT2 in both malignant tumor cells and stromal cells, particularly within CAFs. Notably, our findings also indicated that FERMT2, in particular, exhibited elevated expression levels within tumor tissues and co-expressed with α-SMA in CAFs based on the multiplex immunofluorescence staining results.

Endothelial RSPO3 mediates pulmonary endothelial regeneration by LGR4-dependent activation of β-catenin and ILK signaling pathways after inflammatory vascular injury

Endothelial repair is essential for restoring tissue fluid homeostasis following lung injury. R-spondin3 (RSPO3), a secreted protein mainly produced by endothelial cells (ECs), has shown its protective effect on endothelium. However, the specific mechanisms remain unknown. To explore whether and how RSPO3 regulates endothelial regeneration after inflammatory vascular injury, the role of RSPO3 in sepsis-induced pulmonary endothelial injury was investigated in EC-specific RSPO3 knockdown, inducible EC-specific RSPO3 deletion mice, EC-specific RSPO3 overexpression mice, systemic RSPO3-administration mice, in isolated mouse lung vascular endothelial cells (MLVECs), and in plasma from septic patients. Here we show that plasma RSPO3 levels are decreased in septic patients and correlated with endothelial injury markers and PaO2/FiO2 index. Both pulmonary EC-specific knockdown of RSPO3 and inducible EC-specific RSPO3 deletion inhibit pulmonary ECs proliferation and exacerbate ECs injury, whereas intra-pulmonary EC-specific RSPO3 overexpression promotes endothelial recovery and attenuates ECs injury during endotoxemia. We show that RSPO3 mediates pulmonary endothelial regeneration by a LGR4-dependent manner. Except for β-catenin, integrin-linked kinase (ILK)/Akt is also identified as a novel downstream effector of RSPO3/LGR4 signaling. These results conclude that EC-derived RSPO3 mediates pulmonary endothelial regeneration by LGR4-dependent activation of β-catenin and ILK signaling pathways after inflammatory vascular injury.

Melanoma differentiation associated gene-9/syndecan binding protein promotes hepatocellular carcinoma.

The oncogene Melanoma differentiation associated gene-9/syndecan binding protein (MDA-9/SDCBP) is overexpressed in many cancers, promoting aggressive, metastatic disease. However, the role of MDA-9 in regulating hepatocellular carcinoma (HCC) has not been well studied. To unravel the function of MDA-9 in HCC, we generated and characterized a transgenic mouse with hepatocyte-specific overexpression of MDA-9 (Alb/MDA-9). Compared with wild-type (WT) littermates, Alb/MDA-9 mice demonstrated significantly higher incidence of N-nitrosodiethylamine/phenobarbital-induced HCC, with marked activation and infiltration of macrophages. RNA sequencing (RNA-seq) in naive WT and Alb/MDA-9 hepatocytes identified activation of signaling pathways associated with invasion, angiogenesis, and inflammation, especially NF-κB and integrin-linked kinase signaling pathways. In nonparenchymal cells purified from naive livers, single-cell RNA-seq showed activation of Kupffer cells and macrophages in Alb/MDA-9 mice versus WT mice. A robust increase in the expression of Secreted phosphoprotein 1 (Spp1/osteopontin) was observed upon overexpression of MDA-9. Inhibition of NF-κB pathway blocked MDA-9-induced Spp1 induction, and knock down of Spp1 resulted in inhibition of MDA-9-induced macrophage migration, as well as angiogenesis. Alb/MDA-9 is a mouse model with MDA-9 overexpression in any tissue type. Our findings unravel an HCC-promoting role of MDA-9 mediated by NF-κB and Spp1 and support the rationale of using MDA-9 inhibitors as a potential treatment for aggressive HCC.

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.

Pharmacological targeting of MTHFD2 suppresses NSCLC via the regulation of ILK signaling pathway

Lung cancer is the most common cause of cancer related deaths worldwide with the highest mortality rate. Non-small cell lung cancer (NSCLC) accounts for about 85 % of lung cancers. Mitochondrial methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) is a bifunctional enzyme and is the most differentially expressed metabolic enzyme in various tumors including lung cancer. However, little is known about how MTHFD2 functions in NSCLC. Integrin-linked kinase (ILK) signaling plays key a role in tumor progression including metastasis, proliferation and migration. Here, we show that MTHFD2 inhibition results in suppression of cell growth, migration, invasion and epithelial-mesenchymal transition (EMT) in NSCLC. Microarray analysis suggests that MTHFD2 is positively associated with ILK signaling based on western blotting results. In addition, the phosphorylation of AMPKα plays an essential role in MTHFD2 regulation of ILK signaling. Further, the small-molecule compound C18 inhibits MTHFD2 with great efficiency. C18 blocks MTHFD2/ILK signaling pathway and restrains cell growth, migration, invasion, and EMT of NSCLC and induces apoptosis. In brief, our study found that the positive impact of MTHFD2 is mediated via ILK signaling pathway in NSCLC. Thus, blocking MTHFD2 represents a promising therapeutic strategy against NSCLC clinically.

Retraction Note: Calycosin-7-O-β-D-glucoside promotes oxidative stress-induced cytoskeleton reorganization through integrin-linked kinase signaling pathway in vascular endothelial cells

This article has been retracted. Please see the Retraction Notice for more detail: https://doi.org/10.1186/s12906-015-0839-5.

Translatomic response of retinal Müller glia to acute and chronic stress

Analysis of retina cell type-specific epigenetic and transcriptomic signatures is crucial to understanding the pathophysiology of retinal degenerations such as age-related macular degeneration (AMD) and delineating cell autonomous and cell-non-autonomous mechanisms. We have discovered that Aldh1l1 is specifically expressed in the major macroglia of the retina, Müller glia, and, unlike the brain, is not expressed in retinal astrocytes. This allows use of Aldh1l1 cre drivers and Nuclear Tagging and Translating Ribosome Affinity Purification (NuTRAP) constructs for temporally controlled labeling and paired analysis of Müller glia epigenomes and translatomes. As validated through a variety of approaches, the Aldh1l1cre/ERT2-NuTRAP model provides Müller glia specific translatomic and epigenomic profiles without the need to isolate whole cells. Application of this approach to models of acute injury (optic nerve crush) and chronic stress (aging) uncovered few common Müller glia-specific transcriptome changes in inflammatory pathways, and mostly differential signatures for each stimulus. The expression of members of the IL-6 and integrin-linked kinase signaling pathways was enhanced in Müller glia in response to optic nerve crush but not aging. Unique changes in neuroinflammation and fibrosis signaling pathways were observed in response to aging but not with optic nerve crush. The Aldh1l1cre/ERT2-NuTRAP model allows focused molecular analyses of a single, minority cell type within the retina, providing more substantial effect sizes than whole tissue analyses. The NuTRAP model, nucleic acid isolation, and validation approaches presented here can be applied to any retina cell type for which a cell type-specific cre is available.

Hsa-miR-625 Upregulation Promotes Apoptosis in Acute Myeloid Leukemia Cell Line by Targeting Integrin-linked Kinase Pathway.

Background:Growing evidence has demonstrated that microRNAs have a major effect on development of different types of cancer including AML. The overexpression of miR-625 could decrease tumorgenesis of acute myeloid leukemia cell lines through Integrin-linked kinase signaling pathway and reducing the associated oncogenes. The aim of this study is to evaluate the effect of hsa-miR-625 upregulation on apoptosis and proliferation of KG1 cell line via ILK signaling pathway. Methods: The KG-1 cell line was transfected with pLenti-III-premir625-GFP through viral method. Then, expression of miR-625 and genes were analyzed by quantitative PCR. Western blotting was used to evaluate for the protein level. Apoptosis was investigated by flow cytometry. Cell cycle analysis with PI and CCK-8 assay were performed to evaluate proliferation. Results:KG-1 cells transfected with pLenti-III-pre mir625-GFP construct showed a significant increase in cell apoptosis. Gene expression of ILK and NF-κB were downregulated and AKT, c-fos, Caspase3, cyclin D1, KLF-4, OCT-4 and Nanog were upregulated but no alteration in GSK3 expression profile was observed. Downregulation of NF-κB and upregulation of Caspase 3 and p-β-catenin protein levels were indicated (p<0.05). Conclusion:MiR-625 can be a promising approach to aid in the treatment of AML. However, further studies are required in this respect.

Development of pharmacoproteomic platforms for monitoring changes in the thrombin mediated signaling and aggregation of human platelets treated with direct thrombin inhibitors

Thrombin is a serine‐protease known to induce the activation of platelets to aggregate by binding to and cleaving the extracellular N‐terminal domains of protease‐activated receptors 1 and 4 (PAR1 and PAR4). Dabigatran is an oral anticoagulant and a reversible direct inhibitor of thrombin (DTI), thereby inactivating both fibrin‐bound and unbound (ie, free) thrombin. Recently, it has been shown that dabigatran can inhibit platelet aggregations through a direct effect on platelet thrombin receptors (PAR‐4), which is mainly correlated with a reduced expression of GPIIb/IIIa, CD63, and P‐selectin on platelets after dabigatran treatment. Herein, we engaged on further exploring the human platelets proteome changes in response to thrombin activation in presence of the FDA approved DTI, dabigatran. We hypothesized that a global proteomics analysis of human platelets treated with dabigatran would reveal the integrin‐linked kinase (ILK) and integrin mediated signaling as major pathways which would be down‐regulated in the thrombin‐activated platelets treated with dabigatran. The downregulation of such pathways would explain the dabigatran mediated inhibition of thrombin activated platelets aggregation. To test this hypothesis, we developed a pharmacoproteomics platform that monitor changes in the protein expression profiles of platelets, purified from healthy human donors and ex‐vivo activated with thrombin in presence or absence of dabigatran. The proteomics platform employed the nanoLC‐ESI MS/MS sequencing of tryptic/Glu‐C/Lys‐C generated peptides from platelets releasates, as well as a Q‐Exactive quadrupole orbitrap mass spectrometer coupled with the label free quantification (LFQ) module provided by PEAKS X (Bioinformatics Solutions Inc.). The proteomic analysis retrieved about 300 proteins from the platelets treated with dabigatran as compared with 500 proteins from the platelets control, untreated (FDR &lt;1.0% for proteins and &lt;0.5% for peptides). The quantitative analysis of the biochemical pathways was accomplished with ingenuity pathway analysis (IPA; Ingenuity Systems) using the protein MS1 and MS2 exclusive spectra counts ratios extracted from LFQ analyses. The bioinformatics analysis predicted that many proteins involved in the actin‐mediated cell signaling and movement pathways, including rhoA, rhoGDI, clathrin mediated‐endocytosis, and ILK and integrin signaling pathways, were at least two‐fold statistically significant down‐regulated (p&lt;0.05) in the dabigatran‐treated platelets. Remarkably, biomarkers from the integrin mediated signaling pathways (such as of GPIIb/IIIa) were validated to be down‐regulated by the dabigatran treatment of thrombin activated platelets. In addition, the pharmacoproteomic platform was further validated with novel DTI tetrapeptides lead compounds shown to completely inhibit the thrombin‐induced platelet aggregation at concentrations of 0.8–20 uM. These data further advocate for the use of the LFQ proteomics profiling as a reliable assay for monitoring the efficacy of selected drug treatment during ACS management.Support or Funding InformationFunding: Radiation Oncology Department of Weill Cornell MedicineFigure 1

Oleic acid promotes cell invasion through an integrin-linked kinase signaling pathway in renal cell carcinoma

The change of fatty acid composition has been regarded as an indicator of altered lipid metabolism during human tumourigenesis, but the details are still unclear. We have previously demonstrated a monounsaturated fatty acid (MUFA) named oleic acid (OA) was involved in renal cell carcinoma (RCC) cell growth, as an extracellular signaling molecule to regulate 786-O cell proliferation via the integrin-linked kinase (ILK) pathway. In this study, we further observe the effects of OA on cell invasion of RCC and the potential mechanism by which OA worked was determined. The transwell invasion assay showed OA increased cell invasion of RCC in a dose-dependent manner. Western blotting results indicated ILK, COX-2, and MMP-9 proteins were involved for their high expressions and these effects were reversed when down-regulating the expression of ILK by special siRNA. The MMPs inhibitor GM6001 could weaken the abilities of OA on RCC cells invasion. These results suggested MUFA indeed affected cell invasion of RCC, which was depended by the regulation of ILK pathway.

Therapeutic Chemical Screen Identifies Phosphatase Inhibitors to Reconstitute PKB Phosphorylation and Cardiac Contractility in ILK-Deficient Zebrafish.

Patients with inherited dilated cardiomyopathy (DCM) often suffer from severe heart failure based on impaired cardiac contractility leading to increased morbidity and mortality. Integrin-linked kinase (ILK) as a part of the cardiac mechanical stretch sensor was found to be an essential genetic regulator of cardiac contractility. Integrin-linked kinase localizes to z-disks and costameres in vertebrate hearts and regulates the activity of the signaling molecule protein kinase B (PKB/Akt) by controlling its phosphorylation. Despite identification of several potential drug targets in the ILK signaling pathway, pharmacological treatment strategies to restore contractile function in ILK-dependent cardiomyopathies have not been established yet. In recent years, the zebrafish has emerged as a valuable experimental system to model human cardiomyopathies as well as a powerful tool for the straightforward high-throughput in vivo small compound screening of therapeutically active substances. Using the ILK deficient zebrafish heart failure mutant main squeeze (msq), which shows reduced PKB phosphorylation and thereby impaired cardiac contractile force, we identified here, in an automated small compound screen, the protein phosphatase inhibitors calyculin A and okadaic acid significantly restoring myocardial contractile function by reconstituting PKB phosphorylation in msq ILK-deficient zebrafish embryos.

Tubulin-dependent secretion of S100A6 and cellular signaling pathways activated by S100A6-integrin β1 interaction

S100A6 is a calcium binding protein expressed mainly in fibroblasts and epithelial cells. Interestingly, S100A6 is also present in extracellular fluids. Recently we have shown that S100A6 is secreted by WJMS cells and binds to integrin β1 (Jurewicz et al., 2014). In this work we describe for the first time the mechanism of S100A6 secretion and signaling pathways activated by the S100A6-integrin β1 complex. We show that colchicine suppressed the release of S100A6 into the cell medium, which indicates that the protein might be secreted via a tubulin–dependent pathway. By applying double immunogold labeling and immunofluorescence staining we have shown that S100A6 associates with microtubules in WJMS cells. Furthermore, results obtained from immunoprecipitation and proximity ligation assay (PLA), and from in vitro assays, reveal that S100A6 is able to form complexes with α and β tubulin in these cells, and that the S100A6-tubulin interaction is direct. We have also found that the S100A6 protein, due to binding to integrin β1, activates integrin-linked kinase (ILK), focal adhesion kinase (FAK) and p21-activated kinase (PAK). Our results suggest that binding of S100A6 to integrin β1 affects cell adhesion/proliferation due to activation of ILK and FAK signaling pathways.

Transcriptomic and functional pathways analysis of ascorbate-induced cytotoxicity and resistance of Burkitt lymphoma.

Ascorbate is a pro-oxidant that generates hydrogen peroxide–dependent cytotoxity in cancer cells without adversely affecting normal cells. To determine the mechanistic basis for this phenotype, we selected Burkitt lymphoma cells resistant to ascorbate (JLPR cells) and their ascorbate-sensitive parental cells (JLPS cells). Compared with JLPS cells, the increased glucose uptake in JLPR cells (with upregulated glucose transporters, increased antioxidant enzyme activity, and altered cell cycling) conferred ascorbate–induced cytotoxicity and resistance. Transcriptomic profiles and function pathway analysis identified differentially expressed gene signatures for JLPR cells and JLPS cells, which differential expression levels of five genes (ATF5, CD79B, MHC, Myosin, and SAP18) in ascorbate-resistant cells were related to phosphoinositide 3 kinase, cdc42, DNA methylation and transcriptional repression, polyamine regulation, and integrin-linked kinase signaling pathways. These results suggested that coordinated changes occurred in JLPR cells to enable their survival when exposed to the cytotoxic pro-oxidant stress elicited by pharmacologic ascorbate treatment.

Interplay between intergrin-linked kinase and ribonuclease inhibitor affects growth and metastasis of bladder cancer through signaling ILK pathways.

BackgroundIntegrin-linked kinase (ILK) is a multifunctional adaptor protein which is involved with protein signalling within cells to modulate malignant (cancer) cell movement, cell cycle, metastasis and epithelial–mesenchymal transition (EMT). Our previous experiment demonstrated that ILK siRNA inhibited the growth and induced apoptosis of bladder cancer cells as well as increased the expression of Ribonuclease inhibitor (RI), an important cytoplasmic protein with many functions. We also reported that RI overexpression inhibited ILK and phosphorylation of AKT and GSK3β. ILK and RI gene both locate on chromosome 11p15 and the two genes are always at the adjacent position of same chromosome during evolution, which suggest that ILK and RI could have some relationship. However, underlying interacting mechanisms remain unclear between them. Here, we postulate that RI might regulate ILK signaling pathway via interacting with ILK.MethodsCo-immunoprecipitation, GST pull-down and co-localization under laser confocal microscope assay were used to determine the interaction between ILK and RI exogenously and endogenously. Furthermore, we further verified that there is a direct binding between the two proteins by fluorescence resonance energy transfer (FRET) in cells. Next, The effects of interplay between ILK and RI on the key target protein expressions of PI3K/AKT/mTOR signaling pathway were determined by western blot, immunohistochemistry and immunofluorescence assay in vivo and in vitro. Finally, the interaction was assessed using nude mice xenograft model.ResultsWe first found that ILK could combine with RI both in vivo and in vitro by GST pull-down, co-immunoprecipitation (Co-IP) and FRET. The protein levels of ILK and RI revealed a significant inverse correlation in vivo and in vitro. Subsequently, The results showed that up-regulating ILK could increase cell proliferation, change cell morphology and regulate cell cycle. We also demonstrated that the overexpression of ILK remarkably promoted EMT and expressions of target molecules of ILK signaling pathways in vitro and in vivo. Finally, we found that ILK overexpression significantly enhanced growth, metastasis and angiogenesis of xenograft tumor; Whereas, RI has a contrary role compared to ILK in vivo and in vitro.ConclusionsOur findings, for the first time, directly proved that the interplay between ILK and RI regulated EMT via ILK/PI3K/AKT signaling pathways for bladder cancer, which highlights the possibilities that ILK/RI could be valuable markers together for the therapy and diagnosis of human carcinoma of urinary bladder.

Role of integrin-linked kinase signaling pathway in skin lesions and wound healing in diabetic rats

Objective To investigate the role of integrin-linked kinase (ILK) signaling pathway in the skin lesions and wound healing in diabetic rats. Methods Thirty-six SD rats were divided into diabetic wound group (D) and non-diabetic wound group (N) according to the random number table, with 18 rats in each group. 10 g/L streptozocin (60 mg/kg) was intraperitoneally injected in rats in group D, while the rats in group N were given same quantity of sodium citrate buffer. Two weeks after successful reproduction of diabetic model of rats in group D, two full-thickness skin of an area of 2 cm×2 cm was resected on both sides of back of rats in the two groups. Wounds of three rats of each group were photographed and examined on post injury day (PID) 1, 3, 7, 10, 14, and 21, and the wound healing rates were calculated. The non-injured skin and wound tissue (central part) on back of three rats of the rest 15 rats in the two groups were harvested on PID 3, 7, 10, 14, and 21, respectively. Morphology of the non-injured skin tissue was observed with HE staining, and the thickness of full-thickness skin and epidermis were measured. The mRNA expression levels of ILK, protein kinase B (Akt), and glycogen synthase kinase-3β (GSK-3β) in non-injured skin tissue were determined with real-time fluorescent quantitative RT-PCR. The protein expression levels of ILK, Akt, phosphorylated Akt, GSK-3β, and phosphorylated GSK-3β in non-injured skin tissue, and ILK, phosphorylated Akt in wound tissue were assessed with Western blotting. Data were processed with two independent-sample t test, one-way analysis of variance, SNK test and analysis of variance of factorial design. Results (1) After injury, the wound scabs of rats in group N were dry, and red granulation tissue with no excretion were seen when the scabs fell off, and the wound healed fast. After injury, excretion under the wound scabs of rats in group D was seen, and the scabs easily fell off with exposure of pink granulation tissue with much excretion, and the wounds healed slowly. Except for PID 3, the wound healing rate of rats in group D was significantly lower than that in group N on other PIDs (with t values from 3.858 to 13.738, P 0.05). (4) From PID 3 to 21, the protein expression levels of ILK, Akt and phosphorylated Akt in non-injured skin tissue of rats in group D were significantly lower than those in group N (with t values from 2.630 to 6.209, P 0.05); the protein expression level of phosphorylated GSK-3β in non-injured skin tissue of rats in group D was significantly higher than that in group N (t=4.131, P 0.05), and the protein expression level of phosphorylated Akt in wound tissue was significantly higher than that in non-injured skin tissue (F=117.329, P 0.05), and the protein expression level of phosphorylated Akt in wound tissue was significantly higher than that in non-injured skin tissue (F=184.120, P<0.001). Conclusions The skin lesion of diabetic rats may be related to the declined expression levels of ILK, Akt and phosphorylated Akt in the ILK signaling pathway. The refractory healing of wound in diabetic rats may be related to the declined expression level of phosphorylated Akt. Key words: Diabetes mellitus; Skin; Wound healing; Integrin-linked kinase; Protein kinase B; Glycogen synthase kinase-3β

Calycosin-7-O-β-D-glucoside promotes oxidative stress-induced cytoskeleton reorganization through integrin-linked kinase signaling pathway in vascular endothelial cells.

BackgroundDysfunction of vascular endothelium is implicated in many pathological situations. Cytoskeleton plays an importance role in vascular endothelial permeability barrier and inflammatory response. Many Chinese herbs have the endothelial protective effect, of which, “Astragalus membranaceus” is a highly valued herb for treatment of cardiovascular and renal diseases in traditional Chinese medicine, In this study, we tested whether calycosin-7-O-β-D-glucoside (Calycosin), a main effective monomer component of “Astragalus membranaceus”, could protect endothelial cells from bacterial endotoxin (LPS)-induced cell injury.MethodsEndothelial cell injury was induced by exposing human umbilical vein endothelial cells (HUVECs) to LPS. The effects of calycosin on LPS-induced changes in cell viability, apoptosis rate, cell migration, nitric oxide synthase (NOS), generationof intracellular reactive oxygen species (ROS) and cytoskeleton organization were determined. Microarray assay was employed to screen the possible gene expression change. Based on the results of microarray assay, the expression profile of genes involved in Rho/ROCK pathway and AKT pathway were further evaluated with quantitative real-time RT-PCR or western blot methods.ResultsCalycosin improved cell viability, suppressed apoptosis and protected the cells from LPS-induced reduction in cell migration and generation of ROS, protein level of NOS at a comparable magnitude to that of Y27632 and valsartan. Similar to Y27632 and valsartan, Calycosin, also neutralized LPS-induced actomyosin contraction and vinculin protein aggregation. Microarray assay, real-time PCR and western blot results revealed that LPS induced expression of FN, ITG A5, RhoA, PI3K (or PIP2 in western blotting), FAK, VEGF and VEGF R2, and inhibited expression of MLCP. We believed multiple pathways involved in the regulation of calycosin on HUVECs. Calycosin are considered to be able to activate MLCP through promoting the generation of NO, decreasing PMLC, suppressing the cytoskeleton remodeling caused by activation of Rho/ROCK pathway and inhibiting AKT pathway by decreasing VEGF, VEGF R2 and PI3K level.ConclusionCalycosin protected HUVEC from LPS-induced endothelial injury, possibly through suppression of Rho/ROCK pathway and regulation of AKT pathway.

Impaired ILK Function Is Associated with Deficits in Hippocampal Based Memory and Synaptic Plasticity in a FASD Rat Model.

Fetal Alcohol Spectrum Disorder (FASD) is an umbrella term that encompasses a wide range of anatomical and behavioral problems in children who are exposed to alcohol during the prenatal period. There is no effective treatment for FASD, because of lack of complete characterization of the cellular and molecular mechanisms underlying this condition. Alcohol has been previously characterized to affect integrins and growth factor signaling receptors. Integrin Linked Kinase (ILK) is an effector of integrin and growth-factor signaling which regulates various signaling processes. In FASD, a downstream effector of ILK, Glycogen Synthase Kinase 3β (GSK3β) remains highly active (reduced Ser9 phosphorylation). GSK3β has been known to modulate glutamate receptor trafficking and channel properties. Therefore, we hypothesize that the cognitive deficits accompanying FASD are associated with impairments in the ILK signaling pathway. Pregnant Sprague Dawley rats consumed a “moderate” amount of alcohol throughout gestation, or a calorie-equivalent sucrose solution. Contextual fear conditioning was used to evaluate memory performance in 32–33-day-old pups. Synaptic plasticity was assessed in the Schaffer Collateral pathway, and hippocampal protein lysates were used to evaluate ILK signaling. Alcohol exposed pups showed impaired contextual fear conditioning, as compared to control pups. This reduced memory performance was consistent with decrease in LTP as compared to controls. Hippocampal ILK activity and GSK3β Ser21/9 phosphorylation were significantly lower in alcohol-exposed pups than controls. Increased synaptic expression of GluR2 AMPA receptors was observed with immunoprecipitation of post-synaptic density protein 95 (PSD95). Furthermore, immunoprecipitation of ILK revealed a decreased interaction with GluR2. The ILK pathway appears to play a significant role in memory and synaptic plasticity impairments in FASD rats. These impairments appear to be mediated by reduced GSK3β regulation and increased synaptic stabilization of the calcium-impermeable GluR2 AMPA receptors.

Tripterine Treatment Improves Endothelial Progenitor Cell Function via Integrin-Linked Kinase

Background/Aims: Atherosclerosis is associated with dysfunction of endothelial progenitor cells (EPCs). Tripterine, a chemical compound derived from the Chinese medicinal plant Tripterygium wilfordii Hook, displays anti-inflammatory properties in several animal models. We hypothesized that tripterine can improve EPC function and thus the efficiency of EPC transplantation. Methods and Results: Tripterine preconditioning (2.5 μM, 4 h) improved EPC proliferation, tube formation, migration, and adhesion, and reduced apoptosis in cells cultured in ox-LDL (200 µg/ml). Tripterine restored integrin-linked kinase (ILK) levels downregulated by ox-LDL in EPCs, suggesting the involvement of the ILK/Akt pathway. Small interfering RNA-mediated depletion of ILK and dominant-negative ILK transduction inhibited the phosphorylation of the ILK downstream signaling targets protein kinase B/Akt and glycogen synthase kinase 3-beta (GSK-3β), and reduced β-catenin and cyclin D1 expression. In atherosclerotic mice injected with green fluorescent protein-labeled EPCs to evaluate EPC function, tripterine decreased aortic lesions and plaque deposition, and injection of tripterine-treated EPCs restored ILK levels. Conclusion: The present results suggest that tripterine improves vascular function in atherosclerosis by enhancing EPC function through a mechanism involving the ILK signaling pathway.

Time course of gene expression during mouse skeletal muscle hypertrophy

The purpose of this study was to perform a comprehensive transcriptome analysis during skeletal muscle hypertrophy to identify signaling pathways that are operative throughout the hypertrophic response. Global gene expression patterns were determined from microarray results on days 1, 3, 5, 7, 10, and 14 during plantaris muscle hypertrophy induced by synergist ablation in adult mice. Principal component analysis and the number of differentially expressed genes (cutoffs ≥2-fold increase or ≥50% decrease compared with control muscle) revealed three gene expression patterns during overload-induced hypertrophy: early (1 day), intermediate (3, 5, and 7 days), and late (10 and 14 days) patterns. Based on the robust changes in total RNA content and in the number of differentially expressed genes, we focused our attention on the intermediate gene expression pattern. Ingenuity Pathway Analysis revealed a downregulation of genes encoding components of the branched-chain amino acid degradation pathway during hypertrophy. Among these genes, five were predicted by Ingenuity Pathway Analysis or previously shown to be regulated by the transcription factor Kruppel-like factor-15, which was also downregulated during hypertrophy. Moreover, the integrin-linked kinase signaling pathway was activated during hypertrophy, and the downregulation of muscle-specific micro-RNA-1 correlated with the upregulation of five predicted targets associated with the integrin-linked kinase pathway. In conclusion, we identified two novel pathways that may be involved in muscle hypertrophy, as well as two upstream regulators (Kruppel-like factor-15 and micro-RNA-1) that provide targets for future studies investigating the importance of these pathways in muscle hypertrophy.

A novel role of ribonuclease inhibitor in regulation of epithelial-to-mesenchymal transition and ILK signaling pathway in bladder cancer cells

Human ribonuclease inhibitor (RI) is a cytoplasmic acidic protein possibly involved in biological functions other than the inhibition of RNase A and angiogenin activities. We have previously shown that RI can inhibit growth and metastasis in some cancer cells. Epithelial-mesenchymal transition (EMT) is regarded as the beginning of invasion and metastasis and has been implicated in the metastasis of bladder cancer. We therefore postulate that RI regulates EMT of bladder cancer cells. We find that the over-expression of RI induces the up-regulation of E-cadherin, accompanied with the decreased expression of proteins associated with EMT, such as N-cadherin, Snail, Slug, vimentin and Twist and of matrix metalloprotein-2 (MMP-2), MMP-9 and Cyclin-D1, both in vitro and in vivo. The up-regulation of RI inhibits cell proliferation, migration and invasion, alters cell morphology and adhesion and leads to the rearrangement of the cytoskeleton in vitro. We also demonstrate that the up-regulation of RI can decrease the expression of integrin-linked kinase (ILK), a central component of signaling cascades controlling an array of biological processes. The over-expression of RI reduces the phosphorylation of the ILK downstream signaling targets p-Akt and p-GSK3β in T24 cells. We further find that bladder cancer with a high-metastasis capability shows higher vimentin, Snail, Slug and Twist and lower E-cadherin and RI expression in human clinical specimens. Finally, we provide evidence that the up-regulation of RI inhibits tumorigenesis and metastasis of bladder cancer in vivo. Thus, RI might play a novel role in the development of bladder cancer through regulating EMT and the ILK signaling pathway.