JNK pathway in osteoarthritis: pathological and therapeutic aspects

Context: Osteoarthritis (OA) is a common chronic degenerative joint disease resulting in physical disability and reduced quality of life. Different biochemical signaling pathways are involved in the progression of OA, including the c-Jun NH2-terminal kinase (JNK) signal transduction pathway.

Objective: In this study, we have reviewed the recent updates on the association of JNK pathway with OA.

Methods: In this review, we have explored the databases like PubMed, Google Scholar, Medline, Scopus, etc., and collected the most relevant papers of JNK signaling pathway involved in the pathogenesis and therapeutics of OA

Results: JNK has been shown by scientific studies to be activated (phosphorylated) in OA that can play a key role in the cartilage destruction. Activation of JNK causes the phosphorylation of c-Jun that causes decreased proteoglycan synthesis and enhanced production of matrix metalloproteinase 13 (MMP-13). Overproduction of MMP-13 by chondrocytes plays a central role in cartilage degeneration in OA. Thus, targeting JNK pathway might be a promising therapeutic application for the prevention and treatment of OA. A number of JNK-inhibitors have been used in vitro and in vivo studies; however, not yet been translated into human use.

Conclusions: This review study indicates that JNK pathway plays an important role in development and progression of OA, and targeting the JNK pathway might be a potential approach for the treatment of OA in future.     

Determination of potential selective inhibitors for ROCKI and ROCKII isoforms with molecular modeling techniques: structure based docking,ADMET and molecular dynamics simulation

Rho-associated protein kinases (ROCKs) are a member of the serine/threonine protein kinase family and potential therapeutic target for various diseases. This enzyme has two isoforms, Rho-associated protein kinase I (ROCKI) and Rho-associated protein kinase II (ROCKII). They share an overall 65% homology in all amino acid sequence and 92% homology in kinase domains. Since, the kinase domains of ROCKI and ROCKII are highly conserved and similar, the discovery and design of isoform-selective inhibitors are more challenging. Thus, most currently available agents that is against ROCKs exhibit low selectivity and severe side effects. Therefore, this study aimed to elucidate the interaction of compounds that indicated high potential in experimental studies against ROCKI and ROCKII enzymes in the molecular level with molecular modeling techniques. Firstly, we determined the interaction property of catalytic sites of the ROCKs by analyzing with molecular docking. Based on these results, the best ligands (50 compounds) corresponding to experimental studies were selected, and then absorption, distribution, metabolism and excretion – toxicity (ADMET) analysis of these compounds were implemented. According to these study results, the compound 40 for ROCKI and the compound 50 for ROCKII were identified as selective and highly potent inhibitors. And finally, molecular dynamics (MD) simulations were performed for the stability of ROCKs with identified compounds. In the light of this study, it will be possible to treat diseases that ROCKs have a role by developing more effective and specific ROCK inhibitors.

Communicated by Ramaswamy H. Sarma     

Bacterial pili,with emphasis on Mycobacterium tuberculosis curli pili: potential biomarkers for point-of care tests and therapeutics

Context: Novel biomarkers are essential for developing rapid diagnostics and therapeutic interventions

Objective: This review aimed to highlight biomarker characterisation and assessment of unique bacterial pili.

Methods: A PubMed search for bacterial pili, diagnostics, vaccine and therapeutics was performed, with emphasis on the well characterised pili.

Results: In total, 46 papers were identified and reviewed.

Conclusion: Extensive analyses of pili enabled by advanced nanotechnology and whole genome sequencing provide evidence that they are strong biomarker candidates. Mycobacterium tuberculosis curli pili are emphasised as important epitopes for the development of much needed point-of-care diagnostics and therapeutics.     

3D-QSAR-aided design of potent c-Met inhibitors using molecular dynamics simulation and binding free energy calculation

Abstract

Mesenchymal-epithelial transition factor (c-Met) is a member of receptor tyrosine kinase. It involves in various cellular signaling pathways which includes proliferation, motility, migration, and invasion. Over-expression of c-Met has been reported in various cancers. Hence, it is an ideal therapeutic target for cancer. The main objective of the study is to identify crucial residues involved in the inhibition of c-Met kinase and to design a series of potent imidazo [4,5-b] pyrazine derivatives as c-Met inhibitors. Docking was used to identify important active site residues involved in the inhibition of c-Met kinase which was further validated by 100 ns of molecular dynamics simulation and free energy calculation using molecular mechanics generalized born surface area. Furthermore, binding energy decomposition identified that residues Tyr1230, Met1211, Asp1222, Tyr1159, Met1160, Val1092, Ala1108, and Leu1157 contributed favorably to the binding stability of compound 32. Receptor-guided Comparative Molecular Field Analysis (CoMFA) (q² = 0.751, NOC = 6, r² = 0.933) and Comparative Molecular Similarity Indices Analysis (COMSIA) (q² = 0.744, NOC = 6, r² = 0.950) models were generated based on the docked conformation of the most active compound 32. The robustness of these models was tested using various validation techniques and found to be predictive. The results of CoMFA and CoMSIA contour maps exposed the regions favorable to enhance the activity. Based on this information, 27 novel c-Met inhibitors were designed. These designed compounds exhibited potent activity than the most active compound of the existing dataset.

Communicated by Ramaswamy H. Sarma     

Identification of potential ‘lifestyle-responsive’ epigenomic biomarkers in healthy women aged 18–40

Context: Human health is complex and multifaceted; there is a need for biomarkers that reflect the multidimensional nature of health.

Objective: To identify potential epigenomic biomarkers of health in women aged 18–40 participating in a six-month lifestyle intervention, next level health.

Materials and methods: Methylation data were obtained by reduced representation bisulphite sequencing of 21 female intervention participants as well as three non-participants. The Differential Methylation Analysis Package (DMAP) was used to investigate inter- and intra-individual variability and to identify potential targets of transient epigenetic control in the population studied.

Results: Eleven genes were identified as significantly differentially methylated post- intervention in all 21 participants. 1884 genomic locations were found to be differentially methylated amongst the total female population studied representing potential epigenomic biomarkers.

Conclusions: The ability to demonstrate epigenetic changes arising from a lifestyle intervention can provide key information on the relationship between gene regulation, human behaviour and health.     

Effect of confounding factors on a phospho-flow assay of ribosomal S6 protein for therapeutic drug monitoring of the mTOR-inhibitor everolimus in heart transplanted patients

Context: Several assays of monitoring immune cell function have been developed to enhance therapeutic drug monitoring.

Objective: An in vitro-validated whole-blood assay of phosphorylated ribosomal protein S6 (pS6RP) was evaluated for confounders to monitor the mTOR-inhibitor everolimus (ERL).

Materials and methods: Whole blood samples from 87 heart transplant recipients were analyzed for pS6RP-expression in CD3-positive T-cells by phospho-flow analysis.

Results: ERL blood concentration, laboratory parameters, co-medications, demographic and clinical data were reviewed.

Conclusion: Evaluating the pS6RP-assay revealed that pS6RP is influenced by cyclosporine A (CsA) blood concentration, duration of ERL treatment, co-medication with thiazide diuretics and different metabolic parameters.     

Structure based virtual screening, 3D-QSAR,molecular dynamics and ADMET studies for selection of natural inhibitors against structural and non-structural targets of Chikungunya

The transmission of mosquito-borne Chikungunya virus (CHIKV) has large epidemics worldwide. Till date, there are neither anti-viral drugs nor vaccines available for the treatment of Chikungunya. Accumulated evidences suggest that some natural compounds i.e., Epigallocatechin gallate, Harringtonine, Apigenin, Chrysin, Silybin, etc. have the capability to inhibit CHIKV replication in vitro. Natural compounds are known to possess less or no side effects. Therefore, natural compound in its purified or crude extracts form could be the preeminent and safe mode of therapies for Chikungunya. Wet lab screening and identification of natural compounds against Chikungunya targets is a time consuming and expensive exercise. In the present study, we used in silico techniques like receptor-ligand docking, Molecular dynamic (MD), Three Dimensional Quantitative Structure Activity Relation (3D-QSAR) and ADME properties to screen out potential compounds. Aim of the study is to identify potential lead/s from natural sources using in silico techniques that can be developed as a drug like molecule against Chikungunya infection and replication. Three softwares were used for molecular docking studies. Potential ligands selected by docking studies were subsequently subjected 3D-QSAR studies to predict biological activity. Based on docking scores and pIC₅₀ value, potential anti-Chikungunya compounds were identified. Best docked receptor-ligands were also subjected to MD for more accurate estimation. Lipinski’s rule and ADME studies of the identified compounds were also studied to assess their drug likeness properties. Results of in silico findings, led to identification of few best fit compounds of natural origin against targets of Chikungunya virus which may lead to discovery of new drugs for Chikungunya.

Communicated by Ramaswamy H. Sarma     

Biomarker discovery for drug-induced phospholipidosis: phenylacetylglycine to hippuric acid ratio in urine and plasma as potential markers

Context: Drug-induced phospholipidosis is one of the significant concerns in drug development, especially in safety assessment and noninvasive diagnostic tool is highly desirable.

Objective: The objective of this study is to explored novel biomarkers for phospholipidosis using a metabolomic approach.

Method: NMR spectrometry and LC/MS/MS analyses were applied to urine and plasma of rats administrated cationic amphiphilic drugs.

Results: The phenylacetylglycine to hippuric acid ratio in plasma was increased in time and dose-dependent manners; and it was well correlated with histopathological observation.

Conclusion: The plasma phenylacetylglycine to hippuric acid ratio is a potential marker in monitoring drug-induced phospholipidosis.     

Epidermal growth factor,growth differentiation factor-15, and survivin as novel biocompatibility markers in children on chronic dialysis

Context: Chronic dialysis results in aggravation of apoptosis and cell damage, triggered by bioincompatibility of dialysis membranes and peritoneal fluids.

Objective: The aim of study was to assess the usefulness of epidermal growth factor (EGF), growth differentiation factor (GDF)-15, and survivin as novel markers of biocompatibility in dialyzed children.

Materials and methods: Parameters were assessed by ELISA in 19 patients on hemodialysis and 22 children on peritoneal dialysis.

Results: Serum concentrations of analyzed parameters in children on chronic dialysis differed significantly from controls and depended strongly on the dialysis technique.

Conclusions: EGF, GDF-15, and survivin may serve as new biocompatibility markers in children on chronic dialysis.     

Micronuclei as a marker for medical screening of subjects continuously occupationally exposed to low doses of ionizing radiation

Context: Genotoxicity assays are widely employed in human biomonitoring studies to assess genetic damage inflicted by genotoxic agents.

Objective: Evaluation of micronuclei (MN) as a screening marker of occupational ionizing radiation (IR) exposure.

Materials and methods: Using micronucleus test, peripheral blood lymphocytes (PBL) of 402 control and exposed subjects were screened for genetic damage.

Results: The mean frequencies of micronucleus test parameters were significantly higher in exposed persons. Increase of micronucleus yield with duration of exposure (DOE) by 0.303MN/year was revealed.

Discussion and conclusion: The obtained data encourage us to consider MN as valuable markers for preventive medical screening of occupationally exposed groups.     

A new nitrobenzoxadiazole-based GSTP1-1 inhibitor with a previously unheard of mechanism of action and high stability

Context: The nitrobezoxadiazole derivative NBDHEX is a potent inhibitor of glutathione transferase P1-1 (GSTP1-1) endowed with outstanding anticancer activity in different tumor models.

Objective: To characterize by in vitro biochemical and in silico studies the NBDHEX analogues named MC2752 and MC2753.

Materials and methods: Synthesis of MC2752 and MC2753, biochemical assays and in silico docking and normal-mode analyses.

Results: The presence of a hydrophobic moiety in the side chain of MC2753 confers unique features to this molecule. Unlike its parent drug NBDHEX, MC2753 does not require GSH to trigger the dissociation of the complex between GSTP1-1 and TRAF2, and displays high stability towards the nucleophilic attack of the tripeptide under physiological conditions.

Discussion and conclusion: MC2753 may represent a lead compound for the development of novel GSTP1-1 inhibitors not affected in their anticancer action by fluctuations of cellular GSH levels, and characterized by an increased half-life in vivo.     

Nanostructured lipid carriers as semisolid topical delivery formulations for diflucortolone valerate

Context: Topical treatment of skin disease needs to be strategic to ensure high drug concentration in the skin with minimum systemic absorption.

Objective: The aim of this study was to produce semisolid nanostructured lipid carrier (NLC) formulations, for topical delivery of the corticosteroid drug, diflucortolone valerate (DFV), with minimum systemic absorption.

Method: NLC formulations were developed using a high shear homogenization combined with sonication, using Precirol® ATO5 or Tristearin® as the solid lipid, Capryol? or isopropyl myristate as the liquid lipid and Poloxamer® 407 as surfactant. The present study addresses the influence of different formulations composition as solid lipid, liquid lipid types and concentrations on the physicochemical properties and drug release profile from NLCs.

Results and discussion: DFV-loaded NLC formulations possessed average particle size ranging from 160.40?nm to 743.7?nm with narrow polydispersity index. The encapsulation efficiency was improved by adding the lipid-based surfactants (Labrasol® and Labrafil® M1944CS) to reach 68%. The drug release from the investigated NLC formulations showed a prolonged release up to 12?h. The dermatopharmacokinetic study revealed an improvement in drug deposition in the skin with the optimized DFV-loaded NLC formulation, in contrast to a commercial formulation.

Conclusion: NLC provides a promising nanocarrier system that work as reservoir for targeting topical delivery of DFV.     

Methionine metabolism and multiple sclerosis

Context: Methylation reactions are particularly important in the brain and their inhibition can lead to a number of serious pathologies. Multiple sclerosis is one of the most common neurological disorders caused by interaction of genetic and environmental factors, but little is known about its cause or factors that contribute to the disorder. Although multiple sclerosis is primarily regarded as demyelinating disorder, there are no many articles focusing on methionine determination.

Objective: The aim of this work was to investigate whether serum methionine and its related compounds like homocysteine, cysteine, glutathione and asymmetric dimethylarginine were changed in multiple sclerosis patients.

Materials and methods: Sulphur-containing compounds were determined by using high-performance liquid chromatography with electrochemical detection in a single run for providing more complex view on methionine metabolism and asymmetric dimetylarginine was measured by a commercial enzyme-linked immunosorbent assay kit.

Results: Methionine and glutathione were decreased, but homocysteine, asymmetric dimethylarginine and cysteine were unchanged in patients with multiple sclerosis compared with controls.

Conclusions: Methionine and glutathione seem to be potential biomarkers for prognosis of the disease.     

Propeptide big-endothelin,N-terminal-pro brain natriuretic peptide and mortality. The Ludwigshafen risk and cardiovascular health (LURIC) study

Context: The endothelin system (Big-ET-1) is a key regulator in cardiovascular (CV) disease and congestive heart failure (CHF).

Objectives: We have examined the incremental value of Big-ET-1 in predicting total and CV mortality next to the well-established CV risk marker N-Terminal Pro-B-Type Natriuretic Peptide (NT-proBNP).

Methods: Big-ET-1 and NT-proBNP were determined in 2829 participants referred for coronary angiography (follow-up 9.9 years).

Results: Big-ET-1 is an independent predictor of total, CV mortality and death due to CHF.

Discussion: The conjunct use of Big-ET-1 and NT-proBNP improves the risk stratification of patients with intermediate to high risk of CV death and CHF.

Conclusions: Big-ET-1improves risk stratification in patients referred for coronary angiography.     

Detection and analysis of endogenous polar volatile organic compounds (PVOCs) in urine for human exposome research

Background: The human exposome, defined as ‘…everything that is not the genome’, comprises all chemicals in the body interacting with life processes. The exposome drives genes x environment (GxE) interactions that can cause long-term latency and chronic diseases. The exposome constantly changes in response to external exposures and internal metabolism. Different types of compounds are found in different biological media.

Objective: Measure polar volatile organic compounds (PVOCs) excreted in urine to document endogenous metabolites and exogenous compounds from environmental exposures.

Methods: Use headspace collection and sorbent tube thermal desorption coupled with bench-top gas chromatography-mass spectrometry (GC-MS) for targeted and non-targeted approaches. Identify and categorize PVOCs that may distinguish among healthy and affected individuals.

Results: Method is successfully demonstrated to tabulate a series of 28 PVOCs detected in human urine across 120 samples from 28 human subjects. Median concentrations range from below detect to 165?ng/mL. Certain PVOCs have potential health implications.

Conclusions: Headspace collection with sorbent tubes is an effective method for documenting PVOCs in urine that are otherwise difficult to measure. This methodology can provide probative information regarding biochemical processes and adverse outcome pathways (AOPs) for toxicity testing.     

Elevated serum leptin levels are associated with low vitamin D,sarcopenic obesity,poor muscle strength,and physical performance in knee osteoarthritis*

Context: The associations between serum leptin, vitamin D status, sarcopenic obesity, muscle strength and physical performance in osteoarthritis (OA) remain uncertain.

Objective: To analyse the relationships between serum leptin, vitamin D status, muscle strength and physical performance in OA patients.

Methods: A total of 208 knee OA patients were enrolled. Serum leptin, vitamin D, muscle strength and physical performance were evaluated.

Results: OA patients with sarcopenic obesity had significantly higher serum leptin levels than those with non-sarcopenic obesity. In addition, knee OA patients with sarcopenic obesity displayed low grip strength and poor physical performance. Furthermore, high serum leptin was negatively associated with vitamin D and physical performance.

Conclusions: Serum leptin levels were correlated with low vitamin D, reduced muscle strength and functional impairment, suggesting that serum leptin might serve as a biomarker reflecting physical performance in OA patients.     

Augmented simvastatin cytotoxicity using optimized lipid nanocapsules: a potential for breast cancer treatment

Context: We noticed paucity in exploiting solutol-based lipid nanocapsules in statins formulations though they carry all favorable properties that are needed for cancer passive targeting such as their small particle size, stealth properties, ability to highly accommodate lipophilic drugs, good internalization and P-gp pump inhibition.

Objective: The aim of this study was to design and optimize new simvastatin drug delivery systems; lipid nanocapsules intended for administration through the intravenous route as potential treatment for breast cancer.

Methods: Optimized nanocapsules were prepared by the phase-inversion method according to a D-optimal mixture design, characterized and assessed for their cytotoxicity.

Results: Three successful models for particle size, polydispersity index (PDI) and percentage of drug released after 48 h were generated. The prepared lipid nanocapsules acquired spherical and homogenous morphology, good stability and tolerance to sterilization. The obtained release profiles demonstrated desired sustained release pattern. Furthermore, testing selected formulations on human breast cancer adenocarcinoma cells showed augmented cytotoxicity of simvastatin reaching low IC50 values as 1.4?±?0.02 μg/ml compared to the pure drug.

Conclusion: The proposed lipid nanocapsules pose promising candidates as simvastatin carriers intended for the targeting of breast cancer.     

Exploring the biochemistry of the prenylome and its role in disease through proteomics: progress and potential

Introduction: Protein prenylation is a ubiquitous covalent post-translational modification characterized by the addition of farnesyl or geranylgeranyl isoprenoid groups to a cysteine residue located near the carboxyl terminal of a protein. It is essential for the proper localization and cellular activity of numerous proteins, including Ras family GTPases and G-proteins. In addition to its roles in cellular physiology, the prenylation process has important implications in human diseases and in the recent years, it has become attractive target of inhibitors with therapeutic potential.

Areas covered: This review attempts to summarize the basic aspects of prenylation integrating them with biological functions in diseases and giving an account of the current status of prenylation inhibitors as potential therapeutics. We also summarize the methodologies for the characterization of this modification.

Expert commentary: The growing body of evidence suggesting an important role of prenylation in diseases and the subsequent development of inhibitors of the enzymes responsible for this modification lead to the urgent need to identify the full spectrum of prenylated proteins that are altered in the disease or affected by drugs. Proteomic tools to analyze prenylated proteins are recently emerging, thanks to the advancement in the field of mass spectrometry coupled to enrichment strategies.     

The prognostic value of MR-proadrenomedullin in patients with acute coronary syndrome complicated by cardiogenic shock

Context: Cardiogenic shock (CS) still remains one of the main causes of death in acute myocardial infarction (AMI).

Objective: The aim of this study was to evaluate the prognostic value of midregional (MR)-proadrenomedullin in AMI complicated by CS.

Methods: Forty-seven consecutive patients were included in our prospective observational study. All patients underwent coronarography and successful percutaneous coronary intervention (PCI). Plasma levels of MR-proADM were measured by a immunofluorescence method. The primary endpoint of the study, defined as cardiovascular death, occurred in 17 patients (36%).

Results and conclusion: Elevated plasma level of MR-proADM, determined 24?h after diagnosis of CS could be a predictor of in-hospital mortality in patients with AMI complicated by CS.     

Molecular insights into cancer drug resistance from a proteomics perspective

Introduction: Resistance to chemotherapy and development of specific and effective molecular targeted therapies are major obstacles facing current cancer treatment. Comparative proteomic approaches have been employed for the discovery of putative biomarkers associated with cancer drug resistance and have yielded a number of candidate proteins, showing great promise for both novel drug target identification and personalized medicine for the treatment of drug-resistant cancer.

Areas covered: Herein, we review the recent advances and challenges in proteomics studies on cancer drug resistance with an emphasis on biomarker discovery, as well as understanding the interconnectivity of proteins in disease-related signaling pathways. In addition, we highlight the critical role that post-translational modifications (PTMs) play in the mechanisms of cancer drug resistance.

Expert opinion: Revealing changes in proteome profiles and the role of PTMs in drug-resistant cancer is key to deciphering the mechanisms of treatment resistance. With the development of sensitive and specific mass spectrometry (MS)-based proteomics and related technologies, it is now possible to investigate in depth potential biomarkers and the molecular mechanisms of cancer drug resistance, assisting the development of individualized therapeutic strategies for cancer patients.