Current Medicinal Chemistry - Volume 19, Issue 30, 2012

Chronic lymphocytic leukemia (CLL) is a common adult leukemia in the Western world with an incidence of 4.2/100,000/year. The clinical course of disease is highly heterogenous; it affects people over 65-70 years of age. This hematologic cancer is characterized by the resistance to apoptosis stimuli predominantly associated with overexpression of antiapoptotic Bcl-2 family members. Therapeutic options for advanced CLL patients are limited. Thus there is an urgent need to discover a novel, less toxic, and much more effective agent(s) or drug combinations for CLL patients. Among chemotherapeutic(s) and immunotherapeutics currently in use, several enzyme inhibitors were tested to gain better results in CLL treatment. Here, we review the main achievements made on targeting of prosurvival Bcl-2 proteins through the use of different approaches, i.e. anti-sense methodology, small molecules that mimic the action of BH3 domain and microRNAs (mainly miRNA-15a and miRNA-16-1).

A polyamine agmatine is produced through decarboxylation of L -arginine by the enzyme arginine decarboxylase and is a new neurotransmitter in central nervous system (CNS). It has been suggested that agmatine has analgesic, anxiolytic and antidepressant activities in animals. In experimental studies, it also generates some favorable effects on cerebral damages and withdrawal syndromes involved in addictive drugs. Furthermore, it modulates some processes of learning and memory. Thus, agmatine may be an important target for the treatment of CNS disorders. However, the abnormal release and transmission of agmatine in brain may also be related to some CNS disorders, such as schizophrenia. Interaction of agmatine with other central neurotransmitter systems, such as the glutamatergic and nitrergic systems, seems to be very important. According to the current literature, we can expect that the central agmatinergic system may be a new key target in development of novel approaches for understanding the etiopathogenesis of CNS disorders and their treatment with drugs. The main goal of this article is to evaluate the effects of agmatine in CNS and underline its pharmacological actions in CNS and drug development.

Human lipoxygenases (LOXs) are the enzymes participating in the metabolism of the polyunsaturated fatty acids and catalyzing their oxidation to a variety of eicosanoids, which as the secondary signal transducers have a major impact on human homeostasis. They are involved in many diseases such as inflammatory responses, cancers, cardiovascular and kidney diseases, neurodegenerative disorders and metabolic syndrome. This review summarizes recent developments concerning human 12S-LOX and rabbit 15-LOX projected upon available structural data of LOX and COX oxidoreductases, with conclusions that might apply to LOX family of enzymes in general. Namely: (i) Human lipoxygenases might act as oligomers consisting of active and apo monomers. (ii) Sequential homodimers might act as structural heterodimers with the dimeric interface formed by the interactions resembling the leucine zipper in the coiled-coil superstructure. (iii) Two commonly recognized domains are not sufficient to explain LOX flexibility. Molecular architecture should contain assignment of another regulatory domain of alpha-beta character, possibly important in molecular signaling, which might provide another avenue for targeted drug development. (iv) Allosteric mechanism might involve orchestrated conformational changes and flexibility of the coils connecting the structured elements and ligands binding in more than one monomer.

Fragment based drug design has emerged as an effective alternative to high throughput screening for the identification of lead compounds in drug discovery in the past fifteen years. Fragment based screening and optimization methods have achieved credible success in many drug discovery projects with one approved drug and many more compounds in clinical trials. The fragment based drug design starts with the identification of fragments or low molecular weight compounds that generally bind with weak affinity to the target of interest. The fragments that form high quality interactions are then optimized to lead compounds with high affinity and selectivity. The weak affinity of fragments for their target requires the use of biophysical techniques such as nuclear magnetic resonance, X-ray crystallography or surface plasmon resonance to identify hits. These techniques are very sensitive and some of them provide detailed protein fragment interaction information that is important for fragment to lead optimization. Despite the huge advances in technology in the past years, experimental methods of fragment screening suffer several challenges such as low throughput, high cost of instruments and experiments, high protein and fragment concentration requirements. To address challenges posed by experimental screening approaches, computational methods were developed that play an important role in fragment library design, fragment screening and optimization of initial fragment hits. The computational approaches of fragment screening and optimization are most useful when they are used in combination with experimental approaches. The use of virtual fragment based screening in combination with experimental methods has fostered the application of fragment based drug design to important biological targets including protein-protein interactions and membrane proteins such as GPCRs. This review provides an overview of experimental and computational screening approaches used in fragment based drug discovery with an emphasis on recent successes achieved in discovering potent lead molecules using these approaches.

Emerging evidence indicates that many aspects of alcohol and drug dependence involve changes in glutamate transmission. A number of studies have reported that drugs of abuse, including alcohol and cocaine, alter glutamate transport. Extracellular glutamate is regulated by a number of glutamate transporters in various brain regions. Of these transporters, glutamate transporter (GLT1) is a key player in the removal of most of the extracellular glutamate. Similar to neurodegenerative disease models, in which there is dysfunction of the glutamatergic excitatory system, the role of GLT1 has been tested in drug dependence models that show dysfunction of glutamate transmission. We and others have recently found that ceftriaxone, an FDA-approved drug known to elevate GLT1 expression, attenuates cue-induced cocaine relapse. Moreover, we recently found that alcohol-preferring rats treated with ceftriaxone showed a significant dosedependent reduction in alcohol consumption. We also demonstrated that ceftriaxone-induced upregulation of GLT1 expression was associated with increases in glutamate uptake in Huntington's disease mouse model. Importantly, ceftriaxone is currently in clinical trials for the treatment of amyotrophic lateral sclerosis. This review provides information about the potential therapeutic role of GLT1 for the treatment of alcohol abuse and dependence.

This research evaluated the effect of multiple-wave lasertherapy on the healing process of surgical wounds based on in vitro models denominated stem-dermal equivalents. These human skin models were obtained from a co-culture of dermal cells and bone marrow mesenchymal stem cells. The experimental tests were carried out using a LED portable to multiple waves (operating at 660 nm and 810 nm) at different doses to induce photobiostimulation (10 to 70 mJ.cm-2). Moreover, a photosensitizer drug was employed as a new advanced designed nanomaterial, being a nanoemulsion with biopolymers to obtain an efficient drug delivery system to release lipophilic compounds. The studies were performed considering the light combination application monitoring the kinetic contraction of the dermal equivalent model and the quantification of important macromolecules (as metaloproteases derivatives), related directly with wound healing process. Results showed that an appropriate photomodulation using the combination of both wavelengths (in the red and infrared range) is possible, such that it can contribute to wound healing therapy and/or other pathological skin disease treatment.

The molecular mechanisms that regulate the proliferation and differentiation of induced pluripotent stem (iPS) cells are of great interest. However, whether stimulation with nicotine enhances the proliferation and differentiation of iPS cells has not been investigated. In the present study, western blot analysis revealed that the α4-nAchR and α7-nAchR are expressed in mouse iPS cells. Mouse iPS cells were treated with nicotine for 24 h under feeder-free conditions. Mouse iPS cells were guided to differentiate into mesodermal progenitor cells on type IV collagen (Col IV)-coated dishes in differentiation medium. Mouse iPS cells were guided to differentiate into neural progenitor cells by embryoid body (EB) formation on ultra-low-attachment dishes. After 4 days of growth, all-trans retinoic acid (ATRA; 1 μM) or nicotine (300 nM) was added to the EB cultures and maintained for additional 4 days and plated onto fibronectincoated plates. A BrdU incorporation assay showed that treatment with 300 nM nicotine significantly increased the DNA synthesis of mouse iPS cells or mouse iPS cell-derived mesodermal progenitor cells. This effect was significantly inhibited by pretreatment with an α4-nAchR antagonist, an α7-nAchR antagonist, or a CaMKII inhibitor. The differentiation potential of mouse iPS cells into mesodermal progenitor cells or neural progenitor cells was not affected by the nicotine treatment. The present study indicates that stimulation of the α4-nAchR and α7-nAchR may lead to a significant increase in the proliferation of mouse iPS cells or mouse iPS cell-derived mesodermal progenitor cells through the CaMKII signaling pathway.

The effect of substances known as inducers of neuronal differentiation on cultured human and mouse adipose-derived mesenchymal stem cells (ASCs) and their fate after transplantation into the injured and ischemic mouse brains were studied. ASCs were isolated from the human and mouse adipose tissue. Inducers of neuronal differentiation included β-mercaptoethanol, glial cell line-derived neurotrophic factor (GNDF), brain-derived neurotrophic factor (BDNF), retinoic acid (RA), 5-azacytidine, as well as their combinations. Three days after the induction, the phenotype of the induced cells was analyzed using immunocytochemistry and real-time PCR assay for differential expression of specific genes. The induction efficiency was evaluated by the increased transcription of neuronal differentiation markers: nestin, β-III-tubulin (Tub-B), microtubule-associated protein 2 (MAP2), and neuron-specific enolase (ENO2). The expression of marker genes was tested by immunocytochemical analysis. ASC cultivation in the medium with RA or BDNF in combination with 5- azacytidine for a week increased the mRNA and protein levels of nestin, Tub-B, and ENO2. The transplantation of induced mouse ASCs into the mouse brain increased the lifespan of the cells relative to control uninduced cells and promoted their migration from the transplantation site to the recipient cerebral parenchyma. The transplantation of the induced cells into the mouse brain pre-exposed to endothelin- 1 promoted a more active cell migration into the surrounding ischemic brain tissue. Thus, ASC exposure to RA or BDNF in combination with 5-azacytidine elevated the transcription of the neuronal differentiation markers and improved the viability and integration of ASCs grafted into the mouse brain.

Background: The chromosome 12q24 locus is linked to bipolar disorder, depression, and type 2 diabetes (T2D). PSMD9 lies in the 12q24 locus and is linked to MODY3, T2D, T2D-nephropathy, T2D-neuropathy, retinopathy, macrovascular pathology, hypertension, and hypercholesterolemia in Italian families. Interestingly, PSMD9 gene common variants contribute to the therapeutic response to anti-depressant treatment. Further, PSMD9 is implicated in a model of prediction to susceptibility to depression. Aims: Our goal was to determine whether PSMD9 is linked to depression in 200 T2D Italian families. Methods: We characterized the Italian families' members for presence and/or absence of depression using the diagnostic criteria of DSM-IV. The phenotype was described as unknown in all cases in which the diagnosis was unclear or data were not available. We tested in the 200 Italians families for evidence of linkage of the PSMD9 single nucleotide polymorphisms (SNPs) IVS3+nt460 A>G, IVS3+nt437 T>C and E197G A>G with the depression phenotype. The non-parametric linkage analysis was performed by using the Merlin software. To rule out results due to random chance, 1000 replicates were executed. Results: The PSMD9 gene SNPs studied and/or any gene variants in linkage disequilibrium with them are linked to depression in our Italian families. Conclusions: This is the first report of PSMD9 linkage to depression. This finding highlights the pleiotropic effects of PSMD9.

Gestational diabetes (GD) is a common complication during pregnancy. Metabolic changes in GD affect fetal development and fetal glucose homeostasis. The present study utilized a rat model of GD to evaluate the effects of nicotinamide on diabetic parameters; antioxidant gene expression viz, superoxide dismutase (SOD) and catalase (CAT); reactive oxygen species (ROS) production by neutrophils and enhancement of lymphocyte mediated immune response. Nicotinamide (50, 100 and 200 mg/kg) was orally supplemented to gestational diabetic rats from days 6 through 20 of gestation. After GD induction, the control group had elevated glucose and reduced insulin while nicotinamide (100 & 200 mg/kg) supplementation reversed these changes. The same doses of nicotinamide upregulated mRNA expressions of SOD and CAT genes in liver but reduced the oxidative burst activity of neutrophils in response to phorbol myristate acetate (PMA), N-formyl-methionyl-leucyl-phenylalanine (FMLP) or E. coli activation. Nicotinamide (100 & 200 mg/kg) supplementation also increased expression of activated T helper (CD4+CD25+) cells and induced proliferation of splenocytes. These findings provide evidence for utilizing nicotinamide as supplement or adjunct to support existing therapeutic agents for gestational diabetes and in pregnant individuals with weakened immune systems.

For decades ribosome biogenesis and translation represent key targets in the antimicrobial drug development to combat bacterial infections. Here we report a survey of various small non-protein coding (ncRNAs) associated with ribosomal protein (r-protein) operons in the bacterial pathogens S. aureus, V. cholerae, S. Typhi and M. tuberculosis. We identified four ncRNA candidates that overlap with important structural regions involved in translational feedback regulation. Most notable are the ncRNA 55 family containing the unique recognition site of the L10-(L12)4 complex that consequently might be involved in L10 operon regulation, and ncRNA StyR 337 that resembles the pseudoknot secondary structure of the S4 regulatory region. These findings potentially implicate the candidate ncRNAs in translational regulation of the corresponding operons. In total we report 28 intergenically encoded ncRNAs that map in sense orientation to 14 ribosomal protein operons and 13 cis-antisense encoded ncRNAs transcribed complementary to nine r-protein mRNAs. All ncRNA candidates were independently validated by extensive Northern blot hybridizations to account for growth-stage specific ncRNA transcription and to check ncRNA integrity. In addition we revisited the str-operon as experimental model to monitor internal initiation of transcription in the operon throughout bacterial growth by real-time PCR. Our data indicate additional facets of ribosomal protein operons transcription, and might lead to novel insights of ribosome biogenesis, as well as exploration of strategies involving differential drug development.

Magnetic nanocomposites (MNCs) have highly been acknowledged in the diagnostics and therapeutic applications. Particularly, the multifunctional MNCs have brought a variety of possibilities in targeted drug delivery as well as non-invasive multimodality imaging. A temperature-responsive magnetic drug delivery system has been developed which is made up of superparamagnetic iron oxide nanoparticles (SIONPs) core and Pluronic shell. The magnetic cores composed of congo red conjugated to SIONPs have been proved beneficial as multimodal imaging agents, while superparamagnetic properties facile conducting the nano or micro systems to the vicinity of targeted tissue. Polymer shell formed by stimuli-responsive Pluronic F127 poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) PEO-PPO-PEO block copolymer serves as the carrier for both hydrophilic and hydrophobic drugs. X-ray diffraction (XRD) and high-resolution transmission electron microscope (HR-TEM) were used to characterize as-synthesized MNCs. Furthermore, vibrating magnetometer experiments showed MNCs having a higher magnetization value than bare magnetic nanoparticles (MNPs) and easy to conduct with an external magnetic field. The hydrodynamic size of MNCs was found to be varying in response to the stimuli temperature. Once the temperature increased, the hydrodynamic radius of MNCs decreased. In addition, the feasibility of the system as a targeted drug delivery system for Alzheimer's diseases (AD) diagnosis and therapy was studied. Searching for reliable targeting molecule, recent approaches for identification of amyloid-β (Aβ) and its derivatives have been evaluated. Consequently, the amyloid-derived diffusible ligands antibodies (anti-ADDLs) have been nominated as potential targeting molecules which can be attached to the MNCs system. The possibility of anti-ADDLs conjugation to DDS has been found promising for the multifunctional drug delivery system for AD diagnosis and therapy. However, further experimental studies are required to assess the performance of the proposed DDS.

Cyanobacteria possess the ability to produce compounds with remarkable biological activity, and have thus attracted the attention of the pharmaceutical industry. Cyanopeptides acting as protease inhibitors have shown potential in the field of pharmacotherapy through regulation of abnormal physiological processes in the human body. Despite the already described cyanopeptide protease inhibitors, the search for new congeners is of considerable interest which may pave the way for more efficient molecules. In this study, the presence of the protease inhibitors aeruginosin and cyanopeptolin with non-, mono- and dichlorination and also genes coding for their synthetases was investigated in 90 cyanobacterial strains. Mass spectrometry analyses highlighted production of 91, 19 and 3 non-, mono- and dichlorinated congeners, respectively. The purified extract of Microcystis botrys SPC759 inhibited 61% of pepsin protease. PCR amplifications of aeruginosin and cyanopeptolin synthetase gene regions were observed in 41 and 28% of evaluated strains, respectively. The sequences obtained for the aerA-aerB (aeruginosin) and mcnC-mcnE (cyanopeptolin) gene regions grouped together with their homologues found in other cyanobacterial strains in the phylogenetic analyses with high bootstrap support. Antimicrobial activity assays performed using all intracellular extracts inhibited 31 and 26% of Gram-negative and Gram-positive pathogenic bacterial growth, respectively. The results of this study showed the production of aeruginosin and cyanopeptolin and the presence of their genes in several cyanobacterial genera for the first time besides the discovery of novel congeners.

Background: Anticholinergic side-effects of antipsychotic drugs are common and can potentially impact on quality of life as well as concordance with medication. Objectives: To investigate prevalence/incidence rates of anticholinergic side-effects of oral antipsychotic drugs over the medium- and long-term. Methods: We included all systematic reviews undertaken by the Cochrane Schizophrenia Group for people who are taking antipsychotic drugs and suffering from schizophrenia or Schizophrenia-like illnesses. The prevalence/ incidence of any anticholinergic side-effects was calculated. Relevant papers from the Cochrane Database were identified in January 2007 and the data was pooled. Side-effect data was grouped into the medium (3-6 months) and long-term (>6 months). We calculated simple frequencies, proportions and confidence intervals. We undertook a comparison within the group and generated a Forrest plot of the data. Results: We identified 177 studies within 54 reviews (N=27328 participants). Anticholinergic side-effects for blurred vision, dry mouth and constipation manifested for antipsychotics ranging from 1 to 40 % over the medium-term and 1 to 41% over long-term respectively. There were no statistical differences beween typicals and atypicals over medium- and long-term. Conclusion: To the best of our knowledge, we have collated the largest amount of data on anticholinergic side-effects for antipsychotics over the medium- and longterm. Anticholinergic side-effects are common over the medium- and long-term. Over the medium- and long-term there were no statistically significant differences between the typicals and atypicals in the main anticholinergic side-effects with one exception. We found that in the long-term, the typical antipsychotics were associated with a significantly higher prevalence of blurred vision.

The distinctive characteristics of nanoparticles, resulting from properties that arise at the nano-scale, underlie their potential applications in the biomedical sector. However, the very same characteristics also result in widespread concerns about the potentially toxic effects of nanoparticles. Given the large number of nanoparticles that are being developed for possible biomedical use, there is a need to develop rapid screening methods based on in silico methods. This study illustrates the application of conceptual Density Functional Theory (DFT) to some carbon nanotubes (CNTs) optimized by means of static DFT calculations. The computational efforts are focused on the geometry of a family of packed narrow-diameter carbon nanotubes (CNTs) formed by units from four to twelve carbons evaluating the strength of the C-C bonds by means of Mayer Bond Orders (MBO). Thus, width and length are geometrical features that might be used to tune the electronic properties of the CNTs. At infinite length, partial semi-conductor characteristics are expected.

Administration of anti-tumor necrosis factor alpha antibodies [anti-TNF]-alpha represents a therapeutic approach aimed to diminish the effects of tumor necrosis factor [TNF]- alpha in Crohn's disease [CD]. Blockade of its action should be related to various changes including those in immune and inflammatory response. There is a growing body of experimental data to suggest that the chronically inflamed intestine may be subjected to considerable oxidative stress. The aim of this study was to study the impact of therapy with anti-TNF [infliximab] on Crohn's disease activity index [CDAI], markers of inflammatory activity and oxidative stress. Fourteen patients with active CD received 5mg/kg of infliximab in a single intravenous infusion. CDAI, erythrocyte sedimentation rate [ESR], C-reactive protein [CRP], fibrinogen [FBG], alpha-1 antitrypsin [AAT], albumin [ALB], ceruloplasmin apoprotein [CP], ferroxidase activity of CP [FOACP], specific enzymatic activity of CP [SEACP] and conjugated dienes [DIE] were determined before treatment in month 0 [M 0], in 1st control period in month 1 [M 1] and in 2nd control period in month 5 [M 5] after treatment. In clinical activity a sustained significant decrease in CDAI was observed, with a significant drop in M 1, remaining in M 5. A significant decrease in ESR in M 1, accompanied by insignificantly reduced levels of CRP and FBG was present. During the further follow up in M 5 a slight increase of ESR, CRP and FBG was noticed. A significant decrease of AAT in M 1 was present; this decrease was followed by a significant increase in M 5. Ceruloplasmin apoprotein levels dropped in M 1, with further slight insignificant increase in M 5. A significant increase of ALB sustaining in M 5 was present. The levels of DIE slightly decreased in M 1 and significantly in M 5, together with the slight increase of the FOACP and SEACP in M 1 and significant increase in M 5. We conclude, that oxidative stress may be important in the pathogenesis and perpetuation of tissue injury in CD patients. The decreasing levels of DIE together with the increase of the FOCP and SEACP after infliximab treatment together with changes of markers of inflammatory activity, can participate in the improvement of clinical status of patients with CD.

G-quadruplex-based DNA aptamers for human thrombin represent promising pharmaceuticals having high anticoagulant activity, rapid clearance from the bloodstream, and availability of DNA antidote. High specificity of aptamers minimizes side-effects but at the same time leads to difficulties when choosing animal model for preclinical trials. Well described minimal G-quadruplex 15-TBA, elongated with hinge and duplex regions 31-TBA, and developed recently modular aptamer RA-36 were investigated thoroughly and compared in this paper. To estimate the species-specificity of aptamers the inhibition constants and types were determined for human fibrinogen hydrolysis with human, bovine, porcine, rabbit, rat, and mouse thrombins using turbidimetric assay. Coagulation tests on human fibrinogen, factor II deficient human plasma and animal plasmas were conducted to verify turbidimetric data and reveal either the concentration effects or the influence of other plasma components. And finally, a set of tests on blood clotting cascade was performed to investigate target-specificity of RA-36 aptamer.