Beneficial effects of Trigonella foenum graecum and sodium orthovanadate on metabolic parameters in experimental diabetes

Oxidative stress in diabetic tissues is accompanied by high-level of free radicals with simultaneously declined antioxidant enzymes status leading to cell membrane damage. The present study was carried out to observe the effect of sodium orthovanadate (SOV) and Trigonella foenum graecum seed powder (TSP) administration on blood glucose and insulin levels, antioxidant enzymes, lipid peroxidation, pyruvate kinase, lactate dehydrogenase and protein kinase C in heart, muscle and brain of the alloxan-induced diabetic rats to see whether the treatment with SOV and TSP was capable of reversing the diabetic effects. Diabetes was induced by administration of alloxan monohydrate (15?mg/100?g body weight), and rats were treated with 2?IU insulin, 0.6?mg/ml SOV, 5% TSP in the diet and a combination of 0.2?mg/ml SOV and 5% TSP separately for 21?days. Blood glucose levels increased markedly in diabetic rats, animals treated with a combined dose of SOV and TSP had glucose levels almost comparable with controls, similar results were obtained in the activities of pyruvate kinase, lactate dehydrogenase, antioxidant enzymes and protein kinase C in diabetic animals. Our results showed that lower doses of SOV (0.2?mg/ml) could be used in combination with TSP to effectively reverse diabetic alterations in experimental diabetes. Copyright ? 2012 John Wiley & Sons, Ltd.     

Protein kinase C-Fyn kinase cascade mediates the oleic acid-induced disassembly of neonatal rat cardiomyocyte adherens junctions

Oleic acid (OA) affects assembly of gap junctions in neonatal cardiomyocytes. Adherens junction (AJ) regulates the stability of gap junction integrity; however, the effect of OA on AJ remains largely unexplored. The distribution of N-cadherin and catenins at cell–cell junction was decreased by OA. OA induced activation of protein kinase C(PKC)-α and -? and Src family kinase, and all three kinases were involved in the oleic acid-induced disassembly of the adherens junction, since it was blocked by pretreatment with Gö6976 (a PKCα inhibitor), ?V1–2 (a PKC? inhibitor), or PP2 (a Src family kinase inhibitor). Src family kinase appeared to be the downstream of PKC-α and -?, as blockade of either PKC-α or -? activity prevented the OA-induced activation of Src family kinase. Immunoprecipitation analyses showed that OA activated Fyn and Fer. OA promoted the association of p120 catenin/β-catenin with Fyn and Fer and caused increased tyrosine phosphorylation of p120 catenin and β-catenin, resulting in decreased binding of the former to N-cadherin and of the latter to α-catenin. Pretreatment with PP2 abrogated this OA-induced tyrosine phosphorylation of p120 catenin and β-catenin and restored the association of N-cadherin with p120 catenin and that of β-catenin with α-catenin. In conclusion, these results show that OA activates the PKC-Fyn signaling pathway, leading to the disassembly of the AJ. Therefore, inhibitors of PKC-α/-? and Src family kinase are potential candidates as cardioprotection agents against OA-induced heart injury during ischemia-reperfusion.     

Prostaglandin E₂ modulates proximal tubule Na+-ATPase activity: cooperative effect between protein kinase A and protein kinase C

Previous data showed that prostaglandin E? (PGE?) mediates the inhibitory effect of bradykinin (BK) on proximal tubule (PT) Na+-ATPase activity. The aim of this work was to investigate the molecular mechanisms involved in the effect of PGE? on PT Na+-ATPase. We used isolated basolateral membrane (BLM) from pig PT, which expresses several components of different signaling pathways. The inhibitory effect of PGE? on PT Na+-ATPase activity involves G-protein and the activation of protein kinase A (PKA) because: (1) PGE? increased [3?S]GTPγS binding; (2) GDPβS abolished the inhibitory effect of PGE?; (3) PGE? increased PKA activity; (4) the inhibitory effect of PGE? was abolished by PKA inhibitor peptide. We observed that the PKA-mediated inhibitory effect of PGE? on PT Na+-ATPase activity requires previous activation of protein kinase C. In addition, we observed that PGE? stimulates Ca2+-independent phospholipase A? activity representing an important positive feedback to maintain the inhibition of the enzyme. These results open new perspectives to understanding the mechanism involved in the effect of PGE? on proximal tubule sodium reabsorption.     

Inhibition of the ATR/Chk1 Pathway Induces a p38-Dependent S-phase Delay in Mouse ES Cells

Ataxia-telangiectasia mutated (ATM) and ATM- and Rad3-related (ATR)kinases, family members of the PI-3 kinase related proteins, play a key role in checkpointactivation and maintenance of genomic stability following DNA damage. We have usedwild type (WT) and p38?-deficient mouse embryonic stem (ES) cells to investigate therole of ATR and ATM kinases during embryonic cell cycle. We have found thatinhibition of ATR and ATM kinases with caffeine or Chk1 with UCN-01, results inactivation of a p38-dependent intra-S-phase checkpoint and activation of apoptosis in EScells. However, wortmannin at a concentration, that inhibits ATM kinase but not ATRkinase, did not affect cell cycle progression. Furthermore, the presence of caffeine resultsin activation of p38 kinase, accumulation of p21/Waf1 in a complex with Cdk2 anddecrease of Cdk2 kinase activity. In contrast, caffeine-treated p38?-/- ES cells show lessapoptosis, and fail to trigger an effective S-phase checkpoint and accumulation ofp21/Waf1. We conclude that ATR kinase activity is essential for normal cell cycleprogression of exponentially proliferating mouse ES cells even in the absence ofexogenous DNA damage, and ATR deregulation triggers p38?-dependent cell-cyclecheckpoint and apoptotic responses.     

Hidden prenatal malnutrition in the rat: role of β₁-adrenoceptors on synaptic plasticity in the frontal cortex

Moderate reduction in the protein content of the mother's diet (hidden malnutrition) does not alter body and brain weights of rat pups at birth, but leads to dysfunction of neocortical noradrenaline systems together with impaired long-term potentiation and visuo-spatial memory performance. As β?-adrenoceptors and downstream protein kinase signaling are critically involved in synaptic long-term potentiation and memory formation, we evaluated the β?-adrenoceptor density and the expression of cyclic-AMP dependent protein kinase, calcium/calmodulin-dependent protein kinase and protein kinase Fyn, in the frontal cortex of prenatally malnourished adult rats. In addition, we also studied if β?-adrenoceptor activation with the selective β? agonist dobutamine could improve deficits of prefrontal cortex long-term potentiation presenting these animals. Prenatally malnourished rats exhibited half of β?-adrenoceptor binding, together with a 51% and 65% reduction of cyclic AMP-dependent protein kinase α and calcium/calmodulin-dependent protein kinase α expression, respectively, as compared with eutrophic animals. Administration of the selective β? agonist dobutamine prior to tetanization completely rescued the ability of the prefrontal cortex to develop and maintain long-term potentiation in the malnourished rats. Results suggest that under-expression of neocortical β?-adrenoceptors and protein kinase signaling in hidden malnourished rats functionally affects the synaptic networks subserving prefrontal cortex long-term potentiation. β?-adrenoceptor activation was sufficient to fully recover neocortical plasticity in the PKA- and calcium/calmodulin-dependent protein kinase II-deficient undernourished rats, possibly by producing extra amounts of cAMP and/or by recruiting alternative signaling cascades.     

900-MHz microwave radiation promotes oxidation in rat brain

Recently, there have been several reports referring to detrimental effects due to radio frequency electromagnetic fields (RF-EMF) exposure. Special attention was given to investigate the effect of mobile phone exposure on the rat brain. Since the integrative mechanism of the entire body lies in the brain, it is suggestive to analyze its biochemical aspects. For this, 35-day old Wistar rats were exposed to a mobile phone for 2?h per day for a duration of 45 days where specific absorption rate (SAR) was 0.9?W/Kg. Animals were divided in two groups: sham exposed (n?=?6) and exposed group (n?=?6). Our observations indicate a significant decrease (P?相似文献   

Testosterone- and phorbol ester-stimulated proliferation in human cultured prostatic stromal cells

Prostatic stromal proliferation may be commonly associated with the development of benign prostatic hyperplasia. In this study, we investigate the role of testosterone and protein kinase C in stimulating cultured stromal cell proliferation. Testosterone increased the uptake of [(3)H]-thymidine into the human cultured prostatic stromal cells, this was reduced by the protein kinase C inhibitors, bisindolylymaleimide (10 nM) and myristoylated protein kinase C inhibitor (mPKCi, 20 microM), but not by G? 6983 (1 microM) or G? 6976 (1 microM). Cells responded to the addition of the PKC activators phorbol 12,13 dibutyrate (PDB), phorbol 12,13 diacetate (PDA), 12-deoxyphorbol 13-acetate (DPA) and 12-deoxyphorbol 13-tetradecanoate (DPT) with proliferation (order of potency DPT> or =PDB>PDA=DPA). The DPT-stimulated proliferative response was inhibited after cells were electroporated with PKCalpha antisense, but not mismatch oligonucleotides (8 microM). These results indicate that PKCalpha is involved in the proliferative response of human cultured prostatic stromal cells.     

Effects of acute Rho kinase inhibition on chronic hypoxia-induced changes in proximal and distal pulmonary arterial structure and function

Hypoxic pulmonary hypertension (HPH) is initially a disease of the small pulmonary arteries. Its severity is usually quantified by pulmonary vascular resistance (PVR). Acute Rho kinase inhibition has been found to reduce PVR toward control values in animal models, suggesting that persistent pulmonary vasoconstriction is the dominant mechanism for increased PVR. However, HPH may also cause proximal arterial changes, which are relevant to right ventricular (RV) afterload. RV afterload can be quantified by pulmonary vascular impedance, which is obtained via spectral analysis of pulsatile pressure-flow relationships. To determine the effects of HPH independent of persistent pulmonary vasoconstriction in proximal and distal arteries, we quantified pulsatile pressure-flow relationships before and after acute Rho kinase inhibition and measured pulmonary arterial structure with microcomputed tomography. In control lungs, Rho kinase inhibition decreased 0 Hz impedance (Z?), which is equivalent to PVR, from 2.1 ± 0.4 to 1.5 ± 0.2 mmHg·min·ml?1 (P < 0.05) and tended to increase characteristic impedance (Z(C)) from 0.21 ± 0.01 to 0.22 ± 0.01 mmHg·min·ml?1. In HPH lungs, Rho kinase inhibition decreased Z? (P < 0.05) without affecting Z(C). Microcomputed tomography measurements performed on lungs after acute Rho kinase inhibition demonstrated that HPH significantly decreased the unstressed diameter of the main pulmonary artery (760 ± 60 vs. 650 ± 80 μm; P < 0.05), decreased right pulmonary artery compliance, and reduced the frequency of arteries of diameter 50-100 μm (both P < 0.05). These results demonstrate that acute Rho kinase inhibition reverses many but not all HPH-induced changes in distal pulmonary arteries but does not affect HPH-induced changes in the conduit arteries that impact RV afterload.     

The Streptomyces-produced antibiotic fosfomycin is a promiscuous substrate for archaeal isopentenyl phosphate kinase

Isopentenyl phosphate kinase (IPK) catalyzes the phosphorylation of isopentenyl phosphate to form the isoprenoid precursor isopentenyl diphosphate in the archaeal mevalonate pathway. This enzyme is highly homologous to fosfomycin kinase (FomA), an antibiotic resistance enzyme found in a few strains of Streptomyces and Pseudomonas whose mode of action is inactivation by phosphorylation. Superposition of Thermoplasma acidophilum (THA) IPK and FomA structures aligns their respective substrates and catalytic residues, including H50 and K14 in THA IPK and H58 and K18 in Streptomyces wedmorensis FomA. These residues are conserved only in the IPK and FomA members of the phosphate subdivision of the amino acid kinase family. We measured the fosfomycin kinase activity of THA IPK [K(m) = 15.1 ± 1.0 mM, and k(cat) = (4.0 ± 0.1) × 10?2 s?1], resulting in a catalytic efficiency (k(cat)/K(m) = 2.6 M?1 s?1) that is 5 orders of magnitude lower than that of the native reaction. Fosfomycin is a competitive inhibitor of IPK (K(i) = 3.6 ± 0.2 mM). Molecular dynamics simulation of the IPK·fosfomycin·MgATP complex identified two binding poses for fosfomycin in the IP binding site, one of which results in a complex analogous to the native IPK·IP·ATP complex that engages H50 and the lysine triangle formed by K5, K14, and K205. The other binding pose leads to a dead-end complex that engages K204 near the IP binding site to bind fosfomycin. Our findings suggest a mechanism for acquisition of FomA-based antibiotic resistance in fosfomycin-producing organisms.     

Synthesis and biological evaluation of 2,4-disubstituted phthalazinones as Aurora kinase inhibitors

A series of 2,4-disubstituted phthalazinones were synthesized and their biological activities, including antiproliferation, inhibition against Aurora kinases and cell cycle effects were evaluated. Among them, N-cyclohexyl-4-((4-(1-methyl-1H-pyrazol-4-yl)-1-oxophthalazin-2(1H)-yl) methyl) benzamide (12c) exhibited the most potent antiproliferation against five carcinoma cell lines (HeLa, A549, HepG2, LoVo and HCT116 cells) with IC₅₀ values in range of 2.2–4.6?μM, while the IC₅₀ value of reference compound VX-680 was 8.5–15.3?μM. Moreover, Aurora kinase assays exhibited that compound 12c was potent inhibitor of AurA and AurB kinase with the IC₅₀ values were 118?±?8.1 and 80?±?4.2?nM, respectively. Molecular docking studies indicated that compound 12c forms better interaction with both AurA and AurB. Furthermore, compound 12c induced G2/M cell cycle arrest in HeLa cells by regulating protein levels of cyclinB1 and cdc2. These results suggested that 12c is a promising pan-Aurora kinase inhibitor for the potential treatment of cancer.     

Regulation of the AMPK-related protein kinases by ubiquitination

How can a constitutively active 'master' kinase with numerous downstream targets preferentially phosphorylate one or more of these without influencing all simultaneously? How might such a system be switched off? The characterization of the role of deubiquitination in regulating the phosphorylation and activation of AMPK (AMP-activated protein kinase)-related kinases by LKB1 suggests a novel and interesting mechanism for conferring signal transduction specificity and control at the kinase substrate level. In this issue of the Biochemical Journal, Al-Hakim et al. show that the AMPK-related kinases NUAK1 (AMPK-related kinase 5) and MARK4 (microtubule-affinity-regulating kinase 4) are polyubiquitinated in vivo and that they serve as substrates of the deubiquitinating enzyme USP9X; furthermore, the first evidence is provided for regulation of AMPK-related kinase family members mediated via unusual Lys(29)/Lys(33) polyubiquitin chains, rather than the more common Lys(48)/Lys(63) linkages.     

Corticosterone-induced rapid phosphorylation of p38 and JNK mitogen-activated protein kinases in PC12 cells

The present study showed that corticosterone (B) could induce a rapid activation of p38 and c-Jun NH(2)-terminal protein kinase (JNK) in PC12 cells. The dose-response and time-response curves were bell-shaped with maximal activation at 10(-9) M and at 15 min. RU38486 had no effect, and bovine serum albumin-coupled B could induce the activation. Genistein failed to block the phosphorylation, suggesting the pathway was not involved in tyrosine kinase activity. Phorbol 12-myristate 13-acetate could mimic, while G?6976 could abolish the actions. These results demonstrated that B might act via a putative membrane receptor to activate p38 and JNK rapidly through a protein kinase C-dependent pathway.     

Mitogen-activated protein kinase 4 is involved in the regulation of mitotic and cytokinetic microtubule transitions in Arabidopsis thaliana

? A mitogen-activated protein kinase kinase kinase (MAPKKK) double mutant, Arabidopsis homologue of nucleus and phragmoplast associated kinase (anp) anp2anp3, and the mitogen-activated protein kinase (MAPK) 4 mutant mpk4 of Arabidopsis thaliana show prominent cytokinetic defects. This prompted the analysis of mitotic and cytokinetic progression as a function of MAPK signalling. Mutants were compared with wild types untreated or treated with the specific MAPKK inhibitor PD98059. ? This study included phenotype analysis, expression analysis of the MPK4 promoter, immunofluorescent localization of MPK4, tubulin and MAP65-1, and time-lapse microscopic visualization of the mitotic microtubule (MT) transitions in control, mutant and inhibitor-treated cells. ? Mutant and inhibitor-treated cells showed defects in mitosis and cytokinesis, including aberrant spindle and phragmoplast formation and drastically delayed or abortive mitosis and cytokinesis. As a result, bi- and multinucleate cells were formed, ultimately disturbing the vegetative tissue patterning. MPK4 was localized to all stages of the expanding phragmoplast, in a pattern similar to that of its putative substrate MAP65-1. ? In this study, MPK4 is shown to be involved in the regulation of mitosis/cytokinesis through modulation of the cell division plane and cytokinetic progression.     

Is MLC phosphorylation essential for the recovery from ROCK inhibition in glioma C6 cells?

Inhibition of Rho-associated protein kinase (ROCK) activity in glioma C6 cells induces changes in actin cytoskeleton organization and cell morphology similar to those observed in other types of cells with inhibited RhoA/ROCK signaling pathway. We show that phosphorylation of myosin light chains (MLC) induced by P2Y? receptor stimulation in cells with blocked ROCK correlates in time with actin cytoskeleton reorganization, F-actin redistribution and stress fibers assembly followed by recovery of normal cell morphology. Presented results indicate that myosin light-chain kinase (MLCK) is responsible for the observed phosphorylation of MLC. We also found that the changes induced by P2Y? stimulation in actin cytoskeleton dynamics and morphology of cells with inhibited ROCK, but not in the level of phosphorylated MLC, depend on the presence of calcium in the cell environment.     

Comparative density functional theory based study of the reactivity of Cu,Ag, and Au nanoparticles and of (111) surfaces toward CO oxidation and NO2 reduction

Development of multi-target drugs is becoming increasingly attractive in the repertoire of protein kinase inhibitors discovery. In this study, we carried out molecular docking, molecular dynamics simulations, molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) binding free energy calculations, principal component analysis (PCA), and dynamical cross-correlation matrices (DCCM) to dissect the molecular mechanism for the valmerin-19 acting as a dual inhibitor for glycogen synthase kinase 3β (GSK3β) and cyclin-dependent kinase 5 (CDK5). Detailed MM-PBSA calculations revealed that the binding free energies of the valmerin-19 to GSK3β/CDK5 were calculated to be ?12.60?±?2.28 kcal mol^-1 and ?11.85?±?2.54 kcal mol^-1, respectively, indicating that valmerin-19 has the potential to act as a dual inhibitor of GSK3β/CDK5. The analyses of PCA and DCCM results unraveled that binding of the valmerin-19 reduced the conformational dynamics of GSK3β/CDK5 and the valmerin-19 bound to GSK3β/CDK5 might occur mostly through a conformational selection mechanism. This study may be helpful for the future design of novel and potent dual GSK3β/CDK5 inhibitors.     

Phytosphingosine-phosphate is a signal for AtMPK6 activation and Arabidopsis response to chilling

? Long-chain bases (LCBs) are pleiotropic sphingolipidic signals in eukaryotes. We investigated the source and function of phytosphingosine-1-phosphate (PHS-P), a phospho-LCB rapidly and transiently formed in Arabidopsis thaliana on chilling. ? PHS-P was analysed by thin-layer chromatography following in?vivo metabolic radiolabelling. Pharmacological and genetic approaches were used to identify the sphingosine kinase isoforms involved in cold-responsive PHS-P synthesis. Gene expression, mitogen-activated protein kinase activation and growth phenotypes of three LCB kinase mutants (lcbk1, sphk1 and lcbk2) were studied following cold exposure. ? Chilling provoked the rapid and transient formation of PHS-P in Arabidopsis cultured cells and plantlets. Cold-evoked PHS-P synthesis was reduced by LCB kinase inhibitors and abolished in the LCB kinase lcbk2 mutant, but not in lcbk1 and sphk1 mutants. lcbk2 presented a constitutive AtMPK6 activation at 22°C. AtMPK6 activation was also triggered by PHS-P treatment independently of PHS/PHS-P balance. lcbk2 mutants grew comparably with wild-type plants at 22 and 4°C, but exhibited a higher root growth at 12°C, correlated with an altered expression of the cold-responsive DELLA gene RGL3. ? Together, our data indicate a function for LCBK2 in planta. Furthermore, they connect PHS-P formation with plant response to cold, expanding the field of LCB signalling in plants.     

Mechanistic studies on human N-acetylgalactosamine kinase

N-Acetylgalactosamine kinase (GALK2) is a small molecule kinase from the GHMP family which phosphorylates N-acetylgalactosamine at the expense of ATP. Recombinant GALK2 expressed in, and purified from, Escherichia coli was shown to be active with the following kinetic parameters: Michaelis constant for ATP, 14?±?3?μM; Michaelis constant for N-acetylgalactosamine, 40?±?14?μM; and turnover number, 1.0?±?0.1?s^?1. The combination of substrate inhibition by N-acetylgalactosamine and α-methylgalactopyranoside acting as an uncompetitive inhibitor with respect to ATP suggested that the enzyme has an ordered ternary complex mechanism in which ATP is the first substrate to bind. The effects of pH on the kinetic parameters provided evidence for ionizable residues playing a role in substrate binding and catalysis. These results are discussed in the context of the mechanisms of the GHMP kinases.     

Cystathionine β-synthase and cystathionine γ-lyase double gene transfer ameliorate homocysteine-mediated mesangial inflammation through hydrogen sulfide generation

Elevated level of homocysteine (Hcy) induces chronic inflammation in vascular bed, including glomerulus, and promotes glomerulosclerosis. In this study we investigated in vitro mechanism of Hcy-mediated monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-2 (MIP-2) induction and determined the regulatory role of hydrogen sulfide (H?S) to ameliorate inflammation. Mouse glomerular mesangial cells (MCs) were incubated with Hcy (75 μM) and supplemented with vehicle or with H?S (30 μM, in the form of NaHS). Inflammatory molecules MCP-1 and MIP-2 were measured by ELISA. Cellular capability to generate H?S was measured by colorimetric chemical method. To enhance endogenous production of H?S and better clearance of Hcy, cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE) genes were delivered to the cells. Oxidative NAD(P)H p47(phox) was measured by Western blot analysis and immunostaining. Phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun NH?-terminal kinase (JNK1/2) were measured by Western blot analysis. Our results demonstrated that Hcy upregulated inflammatory molecules MCP-1 and MIP-2, whereas endogenous production of H?S was attenuated. H?S treatment as well as CBS and CSE doubly cDNA overexpression markedly reduced Hcy-induced upregulation of MCP-1 and MIP-2. Hcy-induced upregulation of oxidative p47(phox) was attenuated by H?S supplementation and CBS/CSE overexpression as well. In addition to that we also detected Hcy-induced MCP-1 and MIP-2 induction was through phosphorylation of ERK1/2 and JNK1/2. Either H?S supplementation or CBS and CSE doubly cDNA overexpression attenuated Hcy-induced phosphorylation of these two signaling molecules and diminished MCP-1 and MIP-2 expressions. Similar results were obtained by inhibition of ERK1/2 and JNK1/2 using pharmacological and small interferring RNA (siRNA) blockers. We conclude that H?S plays a regulatory role in Hcy-induced mesangial inflammation and that ERK1/2 and JNK1/2 are two signaling pathways involved this process.     

Maintenance of metabolic homeostasis by sestrin2 and sestrin3

Chronic activation of mammalian target of rapamycin?complex 1 (mTORC1) and p70 S6 kinase (S6K) in?response to hypernutrition contributes to obesity-associated metabolic pathologies, including hepatosteatosis and insulin resistance. Sestrins are?stress-inducible proteins that activate AMP-activated protein kinase (AMPK) and suppress mTORC1-S6K activity, but their role in mammalian physiology and metabolism has not been investigated. We show that Sestrin2-encoded by the Sesn2 locus, whose expression is induced upon hypernutrition-maintains metabolic homeostasis in liver of obese mice. Sesn2 ablation exacerbates obesity-induced mTORC1-S6K activation, glucose intolerance, insulin resistance, and hepatosteatosis, all of which are reversed by AMPK activation. Furthermore, concomitant ablation of Sesn2 and Sesn3 provokes hepatic mTORC1-S6K activation and insulin resistance even in the absence of nutritional overload and obesity. These results demonstrate an important homeostatic function for the stress-inducible Sestrin protein family in the control of mammalian lipid and glucose metabolism.     

Binding mechanism of caffeic acid and simvastatin to the integrin linked kinase for therapeutic implications: a comparative docking and MD simulation studies

Abstract

Integrin linked kinase (ILK) is a Ser/Thr kinase, which regulates various integrin mediated signaling pathways, and is involved in cell adhesion, migration and differentiation. Alteration in the ILK is responsible for abnormal functioning of the cell system, which may lead to the cancer progression and metastasis. Caffeic acid (CA) and simvastatin are used as antioxidant and possess anticancer properties. Thus, inhibiting the kinase activity of ILK by CA and simvastatin may be implicated in the cancer therapy. In this study, we have performed molecular docking followed by 100?ns MD simulations to understand the interaction mechanism of ILK protein with the CA and simvastatin. Average potential energy was found to be highest in case of ILK–CA complex (?770,949?kJ/mol). Binding free energy was found to be higher in case of simvastatin than CA. Our results indicate that simvastatin binds more effectively to the active pocket of ILK. We further performed MTT assay to understand its anticancer potential. Simvastatin shows the IC₅₀ values for HepG2 and MCF-7 as 19.18?±?0.12 and 13.84?±?0.22?µM, respectively. However, the IC₅₀ value of CA on HepG2 and MCF-7 was reported as 175.50?±?1.44 and 144.90?±?1.53?µM, respectively. Our study provides a deeper insight into the binding mechanism of simvastatin and CA to ILK, which further opens a promising channel for their implications in cancer therapy.