Dual-specific autophosphorylation of kinase IKK2 enables phosphorylation of substrate IκBα through a phosphoenzyme intermediate

Rapid and high-fidelity phosphorylation of two serines (S32 and S36) of IκBα by a prototype Ser/Thr kinase IKK2 is critical for fruitful canonical NF-κB activation. Here, we report that IKK2 is a dual specificity Ser/Thr kinase that autophosphorylates itself at tyrosine residues in addition to its activation loop serines. Mutation of one such tyrosine, Y169, located in proximity to the active site, to phenylalanine, renders IKK2 inactive for phosphorylation of S32 of IκBα. Surprisingly, auto-phosphorylated IKK2 relayed phosphate group(s) to IκBα without ATP when ADP is present. We also observed that mutation of K44, an ATP-binding lysine conserved in all protein kinases, to methionine renders IKK2 inactive towards specific phosphorylation of S32 or S36 of IκBα, but not non-specific substrates. These observations highlight an unusual evolution of IKK2, in which autophosphorylation of tyrosine(s) in the activation loop and the invariant ATP-binding K44 residue define its signal-responsive substrate specificity ensuring the fidelity of NF-κB activation.

'Post-Close' Femoral Arterial Haemostasis at Endovascular Aneurysm Repair using a Dedicated Large-Bore Vascular Closure Device: A Prospective Real-World Audit

PURPOSE

Percutaneous access for endovascular aneurysm repair (EVAR) is commonplace, with its attendant benefits. The combination of continued reduction in device profile and evolution of vascular closure device (VCD) design drives successful and safe percutaneous EVAR. A new such VCD is the MANTA Large-Bore Closure Device designed in two iterations for closure of arterial defects from 10 to 25F. We present a prospective audit of 131 large-bore femoral closures using an 'all-comers' approach to device selection.

MATERIALS AND METHODS

One hundred and thirty-one large-bore femoral arterial defects were analysed. Both 14F and 18F MANTA VCDs were deployed in this series as per instructions for use. Primary objectives were technical success, particularly successful deployment, and haemostasis achieved. Failures were denoted as failure to deploy; failure to achieve haemostasis was denoted as active bleeding, haematoma, or pseudoaneurysm formation requiring intervention. Later complications assessed were vessel occlusion/thrombosis or stenosis.

RESULTS

Seventy-six patients (65 males and 11 females, age 75.2 ± 8.7 years) underwent a range of procedures including EVAR (n = 66), TEVAR (n = 2), and reinterventions (n = 8) requiring large-bore percutaneous femoral arterial access in 131 groins. Of these, the 14F MANTA VCD was used in 61 closures (defects ranging from 12 to 18F) and the 18F in 70 closures (defects ranging from 16 to 24F). Deployments achieved successful haemostasis in 120 (91.6%), and failures occurred in 11(8.4%) groins.

CONCLUSIONS

This study indicates that a post-close approach using the novel MANTA Large-Bore Closure Device can be undertaken successfully to close a range of large-bore femoral arterial defects at EVAR/TEVAR with an acceptable rate of complications.

1430 Mid-Term Outcomes After Endovascular Repair of Popliteal Artery Aneurysms Demonstrate Satisfactory Patency Rates and Safety of Stent-Grafts

Aim

Popliteal artery aneurysms (PAAs) are increasingly treated via an endovascular approach. We present mid-term outcomes of popliteal endovascular aneurysm repair (PEVAR) from a single centre.

Method

A retrospective analysis of a prospective database of consecutive patients who underwent either elective or emergency PEVAR in a single regional vascular centre from January 2010 to August 2020. The patients underwent placement of a heparin-bonded stent-graft (Viabahn Endoprosthesis, WL Gore and Associates, Flagstaff, USA) for PAA >20mm or complications: thromboembolism, rupture or popliteal vein thrombosis. Patency and stent-graft related complications were assessed.

Results

A total of 64 PAAs (mean size 36.8±13.4mm) were treated in 56 patients (mean age 75±10.7 years, 54 (96%) male). Median follow-up was 29.5 months (IQR 36.75). 30-day mortality was 0%. Technical success rate of stent-graft insertion was 100%. 1-year and 5-year primary patency was 83% and 67% respectively; primary-assisted patency at these time points was 86% and 72%, and the corresponding secondary patency was 89% and 75%. 61 out of 64 treated limbs had >1 vessel runoff. The most frequently occurring complication was stent-graft occlusion which affected 11 (17%) limbs. Stent-graft fracture occurred in 1 patient, resulting in endoleak.

Conclusions

Viabahn Endoprosthesis can be used successfully in treatment of PAA with acceptable short- and mid-term patency rates. One in five patients in this cohort required a reintervention, with most complications occurring in the first year postoperatively. Stent-graft fracture occurred only in one patient demonstrating that PEVAR is a safe option for PAA management in the intermediate term.

Comparative analysis of non structural protein 1 of SARS-CoV2 with SARS-CoV1 and MERS-CoV: An in silico study

The recently emerged SARS-CoV2 caused a major pandemic of coronavirus disease (COVID-19). Non structural protein 1 (nsp1) is found in all beta coronavirus that cause severe respiratory disease. This protein is considered as a virulence factor and has an important role in pathogenesis. This study aims to elucidate the structural conformations of nsp1 to aid in the prediction of epitope sites and identification of important residues for targeted therapy against COVID-19. In this study, molecular modelling coupled with molecular dynamics simulations were performed to analyse the conformational landscape of nsp1 homologs of SARS-CoV1, SARS-CoV2 and MERS-CoV. Principal component analysis escorted by free energy landscape revealed that SARS-CoV2 nsp1 protein shows greater flexibility compared to SARS-CoV1 and MERS-CoV nsp1. Sequence comparison reveals that 28 mutations are present in SARS-CoV2 nsp1 protein compared to SARS-CoV1 nsp1. Several B-cell and T-cell epitopes were identified by an immunoinformatics approach. SARS-CoV2 nsp1 protein binds with the interface region of the palm and finger domain of POLA1 via hydrogen bonding and salt bridge interactions. Taken together, these in silico findings may help in the development of therapeutics specific against COVID-19.

Exposure to Spectracide® causes behavioral deficits in Drosophila melanogaster: Insights from locomotor analysis and molecular modeling

This study was focused on gaining insights into the mechanism by which the herbicide- Spectracide®, induces oxidative stress and alters behavior in Drosophila melanogaster. Exposure to Spectracide® (50%) significantly (p < 0.05) reduced the negative geotaxis response, jumping behavior and dampened locomotor activity rhythm in adult flies compared to non-exposed flies. Protein carbonyl levels indicative of oxidative damage increased significantly coupled with down-regulation of Sniffer gene expression encoding carbonyl reductase (CR) and its activity in Spectracide®-exposed flies. In silico modeling analysis revealed that the active ingredients of Spectracide® (atrazine, diquat dibromide, fluazifop-p-butyl, and dicamba) have significant binding affinity to the active site of CR enzyme, with atrazine having comparatively greater affinity. Our results suggest a mechanism by which ingredients in Spectracide® induce oxidative damage by competitive binding to the active site of a protective enzyme and impair its ability to prevent damage to proteins thereby leading to deficits in locomotor behavior in Drosophila.

Ultrasound Assisted On-Table Management of Type III Endoleak at Endovascular Repair of Isolated Giant Common Iliac Aneurysm

Objectives

This report presents the endovascular treatment of a large isolated common iliac artery aneurysm, focusing on the use of on table ultrasonography to characterise and treat an early endoleak that could not be defined by angiography alone.

Report

A 58 year old man presented with an asymptomatic, large (13cm) left common iliac artery aneurysm (LCIAA) whilst being investigated for change in bowel habit. This was treated successfully via a percutaneous approach using left internal iliac embolisation followed by endovascular aneurysm repair (EVAR) with deployment of an aorto-uni-iliac converter system from the LCIA origin to the external iliac artery. A non-characterised endoleak at the end of the procedure was shown to be a type IIIb endoleak by application of immediate on table ultrasonography, allowing immediate supplementary targeted stent graft deployment to cover the leaking segment.

Discussion

The patient was discharged uneventfully and will remain on follow up. On table ultrasonography allowed both localisation and characterisation of an immediate intra-procedural endoleak and confirmed cessation of the endoleak with supplementary stent grafting and thrombosis within the sac.

Conclusions

Isolated CIAA is rare, and endovascular therapy is appropriate for them, given that open surgery, whilst feasible, carries a high morbidity and mortality risk. Application of on-table ultrasound allows definition and targeted treatment of endoleaks, reducing the need for further intervention at a later stage, and thus also reducing the risk of continued pressurisation of the large sac post-EVAR till the next surveillance episode.

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Isolated common iliac artery aneurysms (CIAAs) are very rare.

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They can be asymptomatic but have a high risk of rupture.

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Open repair is high risk and associated with high morbidity/mortality.

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This paper highlights successful endovascular repair of a giant isolated CIAA.

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On table ultrasound helps immediately to characterise and treat endoleaks at EVAR.

An integrated in silico approach to understand protein-protein interactions: human meprin-β with fetuin-A

Human meprin-β, a zinc metalloprotease belonging to the astacin family, have been found to be associated with many pathological conditions like inflammatory bowel disease, fibrosis and neurodegenerative disease. The inhibition of meprin-β by various inhibitors, both macromolecular and small molecules, is crucial in the control of several diseases. Human fetuin-A, a negative acute phase protein involved in inflammatory disease, has recently been identified as an endogenous inhibitor for meprin-β. In this computational study, an integrated in silico approach was performed using existing structural information of meprin-β coupled with ab initio modelling of human fetuin-A to predict a rational model of the complex through protein-protein docking. Further, the models were optimized and validated to generate an ensemble of conformations through extensive molecular dynamics simulation. Virtual alanine scanning mutagenesis was explored to identify hotspot residues on both proteins significant for protein-protein interaction (PPI). The results of the study provide structural insight into PPI between meprin-β and fetuin-A which can be useful in designing molecules to modulate meprin-β activity. Communicated by Ramaswamy H. Sarma.

Pharmacophore modeling coupled with molecular dynamic simulation approach to identify new leads for meprin-β metalloprotease

Human meprin beta metalloprotease, a small subgroup of the astacin family, is a potent drug target for the treatment of several disorders such as fibrosis, neurodegenerative disease in particular Alzheimer and inflammatory bowel diseases. In this study, a ligand-based pharmacophore approach has been used for the selection of potentially active compounds to understand the inhibitory activities of meprin-β by using the sulfonamide scaffold based inhibitors. Using this dataset, a pharmacophore model (Hypo1) was selected on the basis of a highest correlation coefficient (0.959), lowest total cost (105.89) and lowest root mean square deviation (1.31 Å) values. All the pharmacophore hypotheses generated from the candidate inhibitors comprised four features: two hydrogen-bond acceptor, one hydrogen-bond donor and one zinc binder feature. The best validated pharmacophore model (Hypo1) was used for virtual screening of compounds from several databases. The selective hit compounds were filtered by drug likeness property, acceptable ADMET profile, molecular docking and DFT study. Molecular dynamic simulations with the final 10 hit compounds revealed that a large number of non-covalent interactions were formed with the active site and specificity sub-pockets of the meprin beta metalloprotease. This study assists in the development of the new lead molecules as well as gives a better understanding of their interaction with meprin-β.

Example of two novel thiocyanato bridged copper (II) complexes derived from substituted thiosemicarbazone ligand: structural elucidation, DNA/albumin binding, biological profile analysis, and molecular docking study

Two novel copper (II) substituted thiosemicarbazone Schiff base complexes [Cu(L₁)(µ-SCN)]_n(NO₃)₂ (1) and [Cu₂(µ-SCN)(SCN)(L₂)₂](NO₃) (2) have been synthesized by condensing substituted thiosemicarbazides like 4-methyl-3-thiosemicarbazide or 4-ethyl-3-thiosemicarbazide with 2-acetylpyridine. Both the metal complexes 1 and 2 are characterized using different spectroscopic techniques like IR, UV-Vis, ESR spectroscopy followed by elemental analysis, cyclic voltammetric measurement and single crystal X-ray structure analysis. X-ray crystal structure analysis reveal that complex 1 is polymeric while complex 2 is dimeric in nature. The coordination geometry around Cu(II) are square pyramidal in which thiosemicarbazone Schiff base ligand coordinate to the central Cu(II) atom in tridentate fashion. The prominent interaction patterns of 1 and 2 with CT-DNA were examined by employing electronic absorption and emission spectral titrations, cyclic voltammetry and viscosity measurements. All the results show that CT-DNA binds with both copper (II) complexes 1 and 2. Furthermore, protein binding ability in vitro of complexes 1 and 2 with both BSA and HSA were carried out using multispectroscopic techniques and a static quenching pattern was observed in both cases. Molecular docking study was employed to ascertain the exact mechanism of action of 1 and 2 with DNA and protein molecules (BSA and HSA). In vitro cytotoxicity activity of complexes 1 and 2 toward AGS and A549 was evaluated using MTT assay which demonstrates that both complexes 1 and 2 have superior prospectus to act as anticancer agents. Communicated by Ramaswamy H. Sarma.

PLVAP and GKN3 Are Two Critical Host Cell Receptors Which Facilitate Japanese Encephalitis Virus Entry Into Neurons

Japanese Encephalitis Virus (JEV), a globally important pathogen, belongs to the family Flaviviridae, is transmitted between vertebrate hosts by mosquitoes, principally by Culex tritaeniorhynchus. The E-glycoprotein of the virus mediates its attachment to the host cell receptors. In this study, we cloned and purified JEV E-glycoprotein in pET28a vector using E. coli BL21 (DE3) cells. A pull down assay was performed using plasma membrane fraction of BALB/c mouse brain and E-glycoprotein as a bait protein. 2-Dimensional Gel Electrophoresis based separation of the interacting proteins was analyzed by mass spectrometry. Among all the identified partners of E-glycoprotein, PLVAP (Plasmalemma vesicle associated protein) and GKN3 (Gastrokine3) showed significant up-regulation in both JEV infected mouse brain and neuro2a cells. In-silico studies also predicted significant interaction of these receptors with E-glycoprotein. Additionally, overexperssion and silencing of these receptors resulted in increase and reduction in viral load respectively, suggesting them as two critical cellular receptors governing JEV entry and propagation in neurons. In support, we observed significant expression of PLVAP but not GKN3 in post-mortem autopsied human brain tissue. Our results establish two novel receptor proteins in neurons in case of JEV infection, thus providing potential targets for antiviral research.

Environment sensitive fluorescent analogue of biologically active oxazoles differentially recognizes human serum albumin and bovine serum albumin: Photophysical and molecular modeling studies

An environment sensitive fluorophore, 4-(5-(4-(dimethylamino)phenyl)oxazol-2-yl)benzoic acid (DMOBA), that closely mimics biologically active 2,5-disubstituited oxazoles has been designed to probe two homologous serum proteins, human serum albumin (HSA) and bovine serum albumin (BSA) by means of photophysical and molecular modeling studies. This fluorescent analogue exhibits solvent polarity sensitive fluorescence due to an intramolecular charge transfer in the excited state. In comparison to water, the steady state emission spectra of DMOBA in BSA is characterized by a greater blue shift (~10nm) and smaller Stokes' shift (~5980cm^-1) in BSA than HSA (Stokes'shift~6600cm^-1), indicating less polar and more hydrophobic environment of the dye in the former than the latter. The dye-protein binding interactions are remarkably stronger for BSA than HSA which is evident from higher value of the association constant for the DMOBA-BSA complex (K_a~5.2×10⁶M^-1) than the DMOBA-HSA complex (K_a~1.0×10⁶M^-1). Fӧrster resonance energy transfer studies revealed remarkably less efficient energy transfer (8%) between the donor tryptophans in BSA and the acceptor DMOBA dye than that (30%) between the single tryptophan moiety in HSA and the dye, which is consistent with a much larger distance between the donor (tryptophan)-acceptor (dye) pair in BSA (34.5Å) than HSA (25.4Å). Site specific competitive binding assays have confirmed on the location of the dye in Sudlow's site II of BSA and in Sudlow's site I of HSA, respectively. Molecular modeling studies have shown that the fluorescent analogue is tightly packed in the binding site of BSA due to strong steric complementarity, where, binding of DMOBA to BSA is primarily dictated by the van der Waals and hydrogen bonding interactions. In contrast, in HSA the steric complementarity is less significant and binding is primarily guided by polar interactions and van der Waals interactions appear to be less significant in the formation of the HSA-DMOBA complex. Electrostatic interactions contribute significantly in the binding of DMOBA to HSA (-2.09kcal/mol) compared to BSA (-0.47kcal/mol). Electrostatic surface potential calculation reveals that the DMOBA binding site within HSA is highly charged compared to BSA.

One new azido bridged dinuclear copper(ii) thiosemicarbazide complex: synthesis, DNA/protein binding, molecular docking study and cytotoxicity activity

Biological potential of a copper(ii) complex found to exhibit in vitro antiproliferative activity towards two cell lines, AGS and A549 cancer cells.

Insights from Analysis of Binding Sites of Human Meprins: Screening of Inhibitors by Molecular Dynamics Simulation Study

Human meprin-α and-β are important regulators of angiogenesis, cancer, inflammation, fibrosis, and neurodegenerative diseases and hence important therapeutic targets. Meprins are the only astacin proteases that are expressed in membrane-bound and secreted form. The cleavage specificity of human meprins is similar in certain cases but differs markedly in others. The inhibitor selectivity of human meprins is controlled by the specific residues involved in binding at the active-site cleft of the proteases. Meprins are inhibited by various small molecular inhibitors as well as macromolecular endogenous inhibitors, making them good drug targets. In the current study, molecular dynamics simulation was performed for 10 ns on ten systems consisting of two apoenzymes of meprin -α/β and eight complexes of human meprin-α and -β complexed to four inhibitors with different metal binding moieties and comparable Ki values. These simulation studies helped to elucidate the molecular details of how several parameters influence protein-inhibitor binding affinity. Analysis of the interaction energies of the protein-inhibitor complexes revealed the diverse binding nature of this series of inhibitors. Several structural segments of human meprins exhibited certain conformational changes during the simulation time course. Among the inhibitors studied captopril had a different disposition in the meprin-bound complexes compared to the other three inhibitors, namely Pro- Leu-Gly-hydroxamate, galardin and EDTA. Comparison of the interaction energies for each system helped us to conclude that the hydroxamic acid-based inhibitors are the most potent inhibitors of meprins.

Ilioprofunda Endobypass Can Successfully Treat a Post-Operative Femoral Pseudo-Aneurysm

INTRODUCTION

A 75-year-old male patient with significant cardiopulmonary comorbidity presented with a 70-mm left femoral pseudoaneurysm 6 years after aortobifemoral bypass (and prior femoral endarterectomy).

REPORT

As the left superficial femoral artery was occluded, an ilioprofunda endobypass was undertaken following extraperitoneal exposure of the left limb of the bypass graft with subsequent deployment of four Viabahn endoprostheses via the left limb into the proximal left deep femoral artery with successful exclusion of the pseudoaneurysm. The endografts remain patent at 6 months with regression noted in the pseudoaneurysm itself.

DISCUSSION

Post-operative femoral pseudoaneurysm following anastomotic dehiscence has traditionally been treated by open surgical repair. Re-re-do open femoral vascular surgery has a high complication rate. Scarring and potential graft infection may necessitate ligation of involved arteries and extra-anatomic bypasses with an attendant risk of limb loss. Although the common femoral artery is conventionally contraindicated for endograft deployment because of the perceived high risk of stent fracture in a highly mobile zone, an endobypass can avoid the potential complications of open revision groin surgery in an unfit, high-risk patient.

Limit on Tensor Currents from ^{8}Li β Decay

In the standard model, the weak interaction is formulated with a purely vector-axial-vector (V-A) structure. Without restriction on the chirality of the neutrino, the most general limits on tensor currents from nuclear β decay are dominated by a single measurement of the β-ν[over ¯] correlation in ^{6}He β decay dating back over a half century. In the present work, the β-ν[over ¯]-α correlation in the β decay of ^{8}Li and subsequent α-particle breakup of the ^{8}Be^{*} daughter was measured. The results are consistent with a purely V-A interaction and in the case of couplings to right-handed neutrinos (C_{T}=-C_{T}^{'}) limits the tensor fraction to |C_{T}/C_{A}|^{2}<0.011 (95.5% C.L.). The measurement confirms the ^{6}He result using a different nuclear system and employing modern ion-trapping techniques subject to different systematic uncertainties.

Epidemiology of epilepsy and its burden in Kolkata, India

BACKGROUND

Disability-adjusted life year (DALY) is a time-based measure of disease burden incorporating both disability and mortality. Our study aimed to determine the DALY lost from epilepsy in an Indian metropolis.

METHODS

A population-based prospective study on epilepsy was conducted over 5 years (2003-8) in Kolkata, India, on randomly selected 100,802 subjects (males 53,209, females 47,593) to assess prevalence as well as to capture incident cases of epilepsy and those incident cases that died. Standard case definitions were used. The data were used to estimate years of life lost (YLL) due to premature mortality, years of life lived with disability (YLD), and DALY, utilizing the prevalence-based Global Burden of Disease (GBD) 2010 approach. Age- and gender-specific figures were computed.

RESULTS

During 2003-2004, a total of 476 subjects with active epilepsy were detected and the age-adjusted prevalence rate was 4.71 per 1000. Over 5 years, there were 197 incident cases of epilepsy of whom 26 died. The age-adjusted annual incidence rate of epilepsy was 38.3 per 100,000. The all-cause standardized mortality rate (SMR) of epilepsy was 2.4. The burden of epilepsy in the year 2007-8 revealed the overall YLL was 755 per 100,000, and the overall YLD ranged from 14.45 to 31.0 per 100,000 persons depending on the clinical severity of the epilepsy. Both YLL and YLD values were higher in males than in females. The overall DALY lost due to epilepsy in 2007-8 was found to be 846.96 (males 1183.04, females 463.81) per 100,000.

CONCLUSIONS

This is the first study in India to determine the DALY of epilepsy using GBD 2010. The results reveal a substantial burden of epilepsy in our setting. Similar such studies are needed in other parts of India in both urban and rural settings.

A mixed anti-inflammatory and pro-inflammatory response associated with a high dose of corticosteroids

OBJECTIVE

Hydrocortisone, at a low dose (100 mg), induces an anti-inflammatory response including inducing IkBα and suppressing intranuclear NFκB and AP-1 binding and the expression of pro-inflammatory mediators like MMPs. We have now investigated the effect of a high dose of hydrocortisone (300mg=60 mg prednisolone) on NFκB binding and the expression of TLRs, the mediators of TLR signal transduction, MyD88 and TRIF and HMG-B1.

DESIGN AND SUBJECTS

A 300mg of hydrocortisone or saline was injected intravenously in ten normal subjects during 2 separate visits, in a randomized crossover study. Blood samples were obtained at 0, 1, 4, 6 and 24h after the injection and mononuclear cells (MNC) were prepared.

RESULTS

There was a significant increase in glucose (from 92±4 to 116±6 mg/dl), insulin (from 4.5±0.7 to 5.3±0.8 mU/ml) and FFA concentrations (from 0.38±0.1 to 0.80±0.15mM) following the administration of hydrocortisone compared to placebo treatment. While NFκB binding and the mRNA expression of MyD88, TRIF, chemokines and chemokine receptors were suppressed significantly in MNC, there was a paradoxical increase in the mRNA expression of TLR 2, 5 and 9 and HMG-B1 was increased by 103±24%, 107±19%, 56±13% and 58±12% above the baseline, respectively in the MNC. Plasma concentrations of HMG-B1 and MMP-9 increased by 37±12% and 125±22%, respectively, while TNF-α concentrations fell by 27±9%.

CONCLUSION

While this high dose of hydrocortisone exerts a powerful anti-inflammatory effect, it also exerts certain proinflammatory effects mainly on TLRs expression. The known pro-inflammatory effects of glucose and FFAs may have contributed to these effects. These paradoxical pro-inflammatory effects may account for the inability of these drugs to show benefit in clinical trials of septicemia and other severe pro-inflammatory states and might contribute to some of the side effects of corticosteroids use.