Repositioning FDA Drugs as Potential Cruzain Inhibitors from Trypanosoma cruzi: Virtual Screening, In Vitro and In Vivo Studies.

Molecules. 2017 Jun 18;22(6):

Authors: Palos I, Lara-Ramirez EE, Lopez-Cedillo JC, Garcia-Perez C, Kashif M, Bocanegra-Garcia V, Nogueda-Torres B, Rivera G

Abstract
Chagas disease (CD) is a neglected disease caused by the parasite Trypanosoma cruzi, which affects underdeveloped countries. The current drugs of choice are nifurtimox and benznidazole, but both have severe adverse effects and less effectivity in chronic infections; therefore, the need to discover new drugs is essential. A computer-guided drug repositioning method was applied to identify potential FDA drugs (approved and withdrawn) as cruzain (Cz) inhibitors and trypanocidal effects were confirmed by in vitro and in vivo studies. 3180 FDA drugs were virtually screened using a structure-based approach. From a first molecular docking analysis, a set of 33 compounds with the best binding energies were selected. Subsequent consensus affinity binding, ligand amino acid contact clustering analysis, and ranked position were used to choose four known pharmacological compounds to be tested in vitro. Mouse blood samples infected with trypomastigotes from INC-5 and NINOA strains were used to test the trypanocidal effect of four selected compounds. Among these drugs, one fibrate antilipemic (etofyllin clofibrate) and three β-lactam antibiotics (piperacillin, cefoperazone, and flucloxacillin) showed better trypanocidal effects (LC50 range 15.8-26.1 μg/mL) in comparison with benznidazole and nifurtimox (LC50 range 33.1-46.7 μg/mL). A short-term in vivo evaluation of these compounds showed a reduction of parasitemia in infected mice (range 90-60%) at 6 h, but this was low compared to benznidazole (50%). This work suggests that four known FDA drugs could be used to design and obtain new trypanocidal agents.

PMID: 28629155 [PubMed - in process]

Integrated genome and transcriptome sequencing identifies a noncoding mutation in the genome replication factor DONSON as the cause of microcephaly-micromelia syndrome.

Genome Res. 2017 Jun 19;:

Authors: Evrony GD, Cordero DR, Shen J, Partlow JN, Yu TW, Rodin RE, Hill RS, Coulter ME, Lam AN, Jayaraman D, Gerrelli D, Diaz DG, Santos C, Morrison V, Galli A, Tschulena U, Wiemann S, Martel MJ, Spooner B, Ryu SC, Elhosary PC, Richardson JM, Tierney D, Robinson CA, Chibbar R, Diudea D, Folkerth R, Wiebe S, Barkovich AJ, Mochida GH, Irvine J, Lemire EG, Blakley P, Walsh CA

Abstract
While next-generation sequencing has accelerated the discovery of human disease genes, progress has been largely limited to the "low hanging fruit" of mutations with obvious exonic coding or canonical splice site impact. In contrast, the lack of high-throughput, unbiased approaches for functional assessment of most noncoding variants has bottlenecked gene discovery. We report the integration of transcriptome sequencing (RNA-seq), which surveys all mRNAs to reveal functional impacts of variants at the transcription level, into the gene discovery framework for a unique human disease, microcephaly-micromelia syndrome (MMS). MMS is an autosomal recessive condition described thus far in only a single First Nations population and causes intrauterine growth restriction, severe microcephaly, craniofacial anomalies, skeletal dysplasia, and neonatal lethality. Linkage analysis of affected families, including a very large pedigree, identified a single locus on Chromosome 21 linked to the disease (LOD > 9). Comprehensive genome sequencing did not reveal any pathogenic coding or canonical splicing mutations within the linkage region but identified several nonconserved noncoding variants. RNA-seq analysis detected aberrant splicing in DONSON due to one of these noncoding variants, showing a causative role for DONSON disruption in MMS. We show that DONSON is expressed in progenitor cells of embryonic human brain and other proliferating tissues, is co-expressed with components of the DNA replication machinery, and that Donson is essential for early embryonic development in mice as well, suggesting an essential conserved role for DONSON in the cell cycle. Our results demonstrate the utility of integrating transcriptomics into the study of human genetic disease when DNA sequencing alone is not sufficient to reveal the underlying pathogenic mutation.

PMID: 28630177 [PubMed - as supplied by publisher]

Pharmacogenetic biomarkers of response in Crohn's disease.

Pharmacogenomics J. 2017 Jun 20;:

Authors: Linares-Pineda TM, Cañadas-Garre M, Sánchez-Pozo A, Calleja-Hernández MÁ

Abstract
Crohn's disease (CD) is a chronic condition, which affects the immune system. It can also affect any part of the digestive tract and be associated with external manifestations. The causes of the disease remain unknown, although it seems to be the result of a combination of factors, such as genetic predisposition, environment, lifestyle and the composition of the microbiota, among others. The treatment protocol begins with a change in eating and smoking habits, and is continued with different lines of treatment, including corticosteroids, immunomodulators and biologic therapy (infliximab and adalimumab), which have shown differences in response among patients, especially with biologic treatment. Several studies have considered the possibility that these differences in response are caused by the genetic variability of patients. Many genes have been investigated as potential predictors of response to biological drugs, such as ADAM17, ATG16L1, EMSY, CASP9, CCNY, CNTN5, FASLG, FCGR, NOD2, PTGER4, IL13, IL1B, IL27, IL11, IL17F, TNF and TNFR genes. In this review, we will gather the information on influence of gene polymorphisms investigated to date on response to biological drugs in CD patients.The Pharmacogenomics Journal advance online publication, 20 June 2017; doi:10.1038/tpj.2017.27.

PMID: 28631723 [PubMed - as supplied by publisher]

Rare disruptive variants in the DISC1 Interactome and Regulome: association with cognitive ability and schizophrenia.

Mol Psychiatry. 2017 Jun 20;:

Authors: Teng S, Thomson PA, McCarthy S, Kramer M, Muller S, Lihm J, Morris S, Soares DC, Hennah W, Harris S, Camargo LM, Malkov V, McIntosh AM, Millar JK, Blackwood DH, Evans KL, Deary IJ, Porteous DJ, McCombie WR

Abstract
Schizophrenia (SCZ), bipolar disorder (BD) and recurrent major depressive disorder (rMDD) are common psychiatric illnesses. All have been associated with lower cognitive ability, and show evidence of genetic overlap and substantial evidence of pleiotropy with cognitive function and neuroticism. Disrupted in schizophrenia 1 (DISC1) protein directly interacts with a large set of proteins (DISC1 Interactome) that are involved in brain development and signaling. Modulation of DISC1 expression alters the expression of a circumscribed set of genes (DISC1 Regulome) that are also implicated in brain biology and disorder. Here we report targeted sequencing of 59 DISC1 Interactome genes and 154 Regulome genes in 654 psychiatric patients and 889 cognitively-phenotyped control subjects, on whom we previously reported evidence for trait association from complete sequencing of the DISC1 locus. Burden analyses of rare and singleton variants predicted to be damaging were performed for psychiatric disorders, cognitive variables and personality traits. The DISC1 Interactome and Regulome showed differential association across the phenotypes tested. After family-wise error correction across all traits (FWERacross), an increased burden of singleton disruptive variants in the Regulome was associated with SCZ (FWERacross P=0.0339). The burden of singleton disruptive variants in the DISC1 Interactome was associated with low cognitive ability at age 11 (FWERacross P=0.0043). These results identify altered regulation of schizophrenia candidate genes by DISC1 and its core Interactome as an alternate pathway for schizophrenia risk, consistent with the emerging effects of rare copy number variants associated with intellectual disability.Molecular Psychiatry advance online publication, 20 June 2017; doi:10.1038/mp.2017.115.

PMID: 28630456 [PubMed - as supplied by publisher]

The Potential of Pharmacogenomics to Advance Kidney Disease Treatment.

Clin J Am Soc Nephrol. 2017 Jun 19;:

Authors: Birdwell KA, Chung CP

PMID: 28630080 [PubMed - as supplied by publisher]

Pharmacogenetic testing through the direct-to-consumer genetic testing company 23andMe.

BMC Med Genomics. 2017 Jun 19;10(1):47

Authors: Lu M, Lewis CM, Traylor M

Abstract
BACKGROUND: Rapid advances in scientific research have led to an increase in public awareness of genetic testing and pharmacogenetics. Direct-to-consumer (DTC) genetic testing companies, such as 23andMe, allow consumers to access their genetic information directly through an online service without the involvement of healthcare professionals. Here, we evaluate the clinical relevance of pharmacogenetic tests reported by 23andMe in their UK tests.
METHODS: The research papers listed under each 23andMe report were evaluated, extracting information on effect size, sample size and ethnicity. A wider literature search was performed to provide a fuller assessment of the pharmacogenetic test and variants were matched to FDA recommendations. Additional evidence from CPIC guidelines, PharmGKB, and Dutch Pharmacogenetics Working Group was reviewed to determine current clinical practice. The value of the tests across ethnic groups was determined, including information on linkage disequilibrium between the tested SNP and causal pharmacogenetic variant, where relevant.
RESULTS: 23andMe offers 12 pharmacogenetic tests to their UK customers, some of which are in standard clinical practice, and others which are less widely applied. The clinical validity and clinical utility varies extensively between tests. The variants tested are likely to have different degrees of sensitivity due to different risk allele frequencies and linkage disequilibrium patterns across populations. The clinical relevance depends on the ethnicity of the individual and variability of pharmacogenetic markers. Further research is required to determine causal variants and provide more complete assessment of drug response and side effects.
CONCLUSION: 23andMe reports provide some useful pharmacogenetics information, mirroring clinical tests that are in standard use. Other tests are unspecific, providing limited guidance and may not be useful for patients without professional interpretation. Nevertheless, DTC companies like 23andMe act as a powerful intermediate step to integrate pharmacogenetic testing into clinical practice.

PMID: 28629370 [PubMed - in process]

Clinical implications of glutathione S-transferase genotyping in patients with diffuse large B-cell lymphoma.

J BUON. 2016 Nov-Dec;21(6):1459-1465

Authors: Atanaskovic L, Cikota-Aleksic B, Tarabar O, Trimcev J, Zivanovic-Ivic A, Marjanovic S, Magic Z

Abstract
PURPOSE: Polymorphic deletions in glutathione S-transferase (GST) genes are recognized as a risk factor for lymphoma, other hematological and non-hematological malignancies. The purpose of the present study was to investigate whether deletions of GSTT1 and GSTM1 as well as GSTP1 Ile- 105Val single nucleotide polymorphism influence clinical presentation, response to therapy and outcome in patients with diffuse large B-cell lymphoma (DLBCL).
METHODS: The study included a total of 82 DLBCL patients treated with rituximab-CHOP (R-CHOP) therapy (6-8 cycles). GST genes were analyzed with PCR-based methodology.
RESULTS: The obtained frequencies of GSTT1 and GSTM1 null genotypes were 24 and 63%, respectively. The variant GSTP1 Val allele was present in 76% of the patients. No association between GST genotypes and clinical presentation was found. However, a higher frequency of GSTM1 null genotype was observed in patients who developed DLBCL before the age of 60 [odds ratio (OR) 3.12, 95% confidence interval (CI) 1.11-9.17; p=0.03]. Patients carrying at least one GSTP1 Val allele achieved remission in a shorter time period than patients with GSTP1 Ile/Ile genotype (p=0.05). GST genotypes didn't influence the incidence of relapse and survival. There were no toxic effects, life-threatening infections or significant delay in immunochemotherapy in the analyzed group of patients.
CONCLUSION: The present study showed the association of GSTM1 null genotype and DLBCL development before the age of 60 (prognostic cutoff). GST genotypes didn't influence survival, but patients with at least one low-producing GSTP1 Val allele achieved clinical remission in a shorter time period.

PMID: 28039708 [PubMed - indexed for MEDLINE]

FcγRIIa-H131R variant is associated with inferior response in diffuse large B cell lymphoma: A meta-analysis of genetic risk.

J BUON. 2016 Nov-Dec;21(6):1454-1458

Authors: Ziakas PD, Poulou LS, Zintzaras E

Abstract
PURPOSE: Low-affinity variants FcγRIIIa-V158F and FcγRIIa- H131R may alter response to rituximab-based chemotherapy in diffuse large B-cell lymphoma (DLBCL) but available clinical evidence is inconclusive. Our purpose was to explore their association in terms of treatment response.
METHODS: We performed a meta-analysis of published literature to associate these variants with complete remission after upfront immunochemotherapy in DLBCL, and summarized the genetic risk using the model-free approach of generalized odds ratio (ORG). PubMed and EMBASE search (up to July 2014) yielded five pertinent studies.
RESULTS: FcγRIIa-H131R was associated with an inferior response to treatment (ORG 0.67; 95%CI 0.46-0.97) and an additive mode of inheritance, with the genetic risk of heterozygotes assigned in the middle between high affinity (H/H) and lower affinity (R/R) genotypes. This effect was unrelated to risk stratification, as no association was documented for FcγRIIa-H131R variant with the international prognostic index (IPI) (ORG 1.02; 95%CI 0.79-1.31 for IPI 3-5 over 0-2). FcγRIIIa-V158F had no impact on treatment response but linkage disequilibrium and defective antibody-dependent cell-mediated cytotoxicity may have affected the outcome.
CONCLUSION: FcγRIIa-H131R but not FcγRIIIa-V158F may modify treatment response in DLBCL.

PMID: 28039707 [PubMed - indexed for MEDLINE]

Novel 3D Culture Systems for Studies of Human Liver Function and Assessments of the Hepatotoxicity of Drugs and Drug Candidates.

Chem Res Toxicol. 2016 Dec 19;29(12):1936-1955

Authors: Lauschke VM, Hendriks DF, Bell CC, Andersson TB, Ingelman-Sundberg M

Abstract
The liver is an organ with critical importance for drug treatment as the disposition and response to a given drug is often determined by its hepatic metabolism. Patient-specific factors can entail increased susceptibility to drug-induced liver injury, which constitutes a major risk for drug development programs causing attrition of promising drug candidates or costly withdrawals in postmarketing stages. Hitherto, mainly animal studies and 2D hepatocyte systems have been used for the examination of human drug metabolism and toxicity. Yet, these models are far from satisfactory due to extensive species differences and because hepatocytes in 2D cultures rapidly dedifferentiate resulting in the loss of their hepatic phenotype and functionality. With the increasing comprehension that 3D cell culture systems more accurately reflect in vivo physiology, in the recent decade more and more research has focused on the development and optimization of various 3D culture strategies in an attempt to preserve liver properties in vitro. In this contribution, we critically review these developments, which have resulted in an arsenal of different static and perfused 3D models. These systems include sandwich-cultured hepatocytes, spheroid culture platforms, and various microfluidic liver or multiorgan biochips. Importantly, in many of these models hepatocytes maintain their phenotype for prolonged times, which allows probing the potential of newly developed chemical entities to cause chronic hepatotoxicity. Moreover, some platforms permit the investigation of drug action in specific genetic backgrounds or diseased hepatocytes, thereby significantly expanding the repertoire of tools to detect drug-induced liver injuries. It is concluded that the development of 3D liver models has hitherto been fruitful and that systems are now at hand whose sensitivity and specificity in detecting hepatotoxicity are superior to those of classical 2D culture systems. For the future, we highlight the need to develop more integrated coculture model systems to emulate immunotoxicities that arise due to complex interactions between hepatocytes and immune cells.

PMID: 27661221 [PubMed - indexed for MEDLINE]

A Multi-scale Computational Platform to Mechanistically Assess the Effect of Genetic Variation on Drug Responses in Human Erythrocyte Metabolism.

PLoS Comput Biol. 2016 Jul;12(7):e1005039

Authors: Mih N, Brunk E, Bordbar A, Palsson BO

Abstract
Progress in systems medicine brings promise to addressing patient heterogeneity and individualized therapies. Recently, genome-scale models of metabolism have been shown to provide insight into the mechanistic link between drug therapies and systems-level off-target effects while being expanded to explicitly include the three-dimensional structure of proteins. The integration of these molecular-level details, such as the physical, structural, and dynamical properties of proteins, notably expands the computational description of biochemical network-level properties and the possibility of understanding and predicting whole cell phenotypes. In this study, we present a multi-scale modeling framework that describes biological processes which range in scale from atomistic details to an entire metabolic network. Using this approach, we can understand how genetic variation, which impacts the structure and reactivity of a protein, influences both native and drug-induced metabolic states. As a proof-of-concept, we study three enzymes (catechol-O-methyltransferase, glucose-6-phosphate dehydrogenase, and glyceraldehyde-3-phosphate dehydrogenase) and their respective genetic variants which have clinically relevant associations. Using all-atom molecular dynamic simulations enables the sampling of long timescale conformational dynamics of the proteins (and their mutant variants) in complex with their respective native metabolites or drug molecules. We find that changes in a protein's structure due to a mutation influences protein binding affinity to metabolites and/or drug molecules, and inflicts large-scale changes in metabolism.

PMID: 27467583 [PubMed - indexed for MEDLINE]

Chronic Treatment with Isoniazid Causes Protoporphyrin IX Accumulation in Mouse Liver.

Chem Res Toxicol. 2016 Aug 15;29(8):1293-7

Authors: Sachar M, Li F, Liu K, Wang P, Lu J, Ma X

Abstract
Isoniazid (INH) can cause hepatotoxicity. In addition, INH is contraindicated in patients suffering from porphyrias. Our metabolomic analysis revealed that chronic treatment with INH in mice causes a hepatic accumulation of protoporphyrin IX (PPIX). PPIX is an intermediate in the heme biosynthesis pathway, and it is also known as a hepatotoxin. We further found that INH induces delta-aminolevulinate synthase 1 (ALAS1), the rate-limiting enzyme in heme biosynthesis. We also found that INH downregulates ferrochelatase (FECH), the enzyme that converts PPIX to heme. In summary, this study illustrated that chronic treatment with INH causes PPIX accumulation in mouse liver in part through ALAS1 induction and FECH downregulation. This study also highlights that drugs can disrupt the metabolic pathways of endobiotics and increase the risk of liver damage.

PMID: 27438535 [PubMed - indexed for MEDLINE]

Multi-electrode system for measurement of transmembrane ion-fluxes through living epithelial cells.

Bioelectrochemistry. 2017 Jun 13;117:65-73

Authors: Zając M, Lewenstam A, Dolowy K

Abstract
Cystic Fibrosis (CF) is the most common fatal human genetic disease. It is caused by the defect in a single anion channel protein which affects ion and water transport across the epithelial tissue. A flat multi-electrode platform of diameter 12mm, allowing for measurement of four ions: sodium, potassium, hydrogen and chloride by exchangeable/replaceable ion-selective electrodes is described. The measurement is possible owing to the architecture of the platform which accommodates all the electrodes and inlets/outlets. The platform fits to the cup and operates in a small volume of the solution bathing the living epithelial cell layer (membrane) deposited on a porous support of the cup, which allows for effective monitoring of ion concentration changes. By applying two multi-electrode platforms, it is possible to measure the ion transmembrane fluxes. The inlet and outlet tubes in the platforms allow for on-fly change of the calibrants, ion-concentration changes and ion channel blockers. Using different ion-concentration gradients and blockers of ion-transporting molecules we show for the first time that sodium ions flow from the basolateral to apical face of the cell monolayer via a paracellular route and return also via a transcellular one, while chloride anions are transported back and forth exclusively via a transcellular route.

PMID: 28633068 [PubMed - as supplied by publisher]

Drug Hypersensitivity and Desensitizations: Mechanisms and New Approaches.

Int J Mol Sci. 2017 Jun 20;18(6):

Authors: de Las Vecillas Sánchez L, Alenazy LA, Garcia-Neuer M, Castells MC

Abstract
Drug hypersensitivity reactions (HSRs) are increasing in the 21st Century with the ever expanding availability of new therapeutic agents. Patients with cancer, chronic inflammatory diseases, cystic fibrosis, or diabetes can become allergic to their first line therapy after repeated exposures or through cross reactivity with environmental allergens. Avoidance of the offending allergenic drug may impact disease management, quality of life, and life expectancy. Precision medicine provides new tools for the understanding and management of hypersensitivity reactions (HSRs), as well as a personalized treatment approach for IgE (Immunoglobuline E) and non-IgE mediated HSRs with drug desensitization (DS). DS induces a temporary hyporesponsive state by incremental escalation of sub-optimal doses of the offending drug. In vitro models have shown evidence that IgE desensitization is an antigen-specific process which blocks calcium flux, impacts antigen/IgE/FcεRI complex internalization and prevents the acute and late phase reactions as well as mast cell mediator release. Through a "bench to bedside" approach, in vitro desensitization models help elucidate the molecular pathways involved in DS, providing new insights to improved desensitization protocols for all patients. The aim of this review is to summarize up to date information on the drug HSRs, the IgE mediated mechanisms of desensitization, and their clinical applications.

PMID: 28632196 [PubMed - in process]

A low molecular weight alginate oligosaccharide disrupts pseudomonal microcolony formation and enhances antibiotic effectiveness.

Antimicrob Agents Chemother. 2017 Jun 19;:

Authors: Pritchard MF, Powell LC, Jack AA, Powell K, Beck K, Florance H, Forton J, Rye PD, Dessen A, Hill KE, Thomas DW

Abstract
In chronic respiratory disease the formation of dense, 3-dimensional 'micro colonies' by Pseudomonas aeruginosa within the airway plays an important role in contributing to resistance to treatment. An in vitro biofilm model of pseudomonal microcolony formation using artificial sputum (AS) medium was established to study the effects of low molecular weight alginate oligomers (OligoG CF-5/20) on pseudomonal growth, microcolony formation and the efficacy of colistin. The studies employed clinical cystic fibrosis (CF) isolates (n=3) and reference non-mucoid and mucoid multi-drug resistant (MDR) CF isolates (n=7). Bacterial growth, biofilm development and disruption were studied using cell-viability assays and image analysis using scanning electron- and confocal laser scanning microscopy. Pseudomonal growth in AS medium was associated with increased ATP production (p<0.05) and the formation (at 48 h) of discrete (>10 μm) microcolonies. In conventional growth medium, colistin retained an ability to inhibit growth of planktonic bacteria, although the MIC was increased (0.1 to 0.4 μg/ml) in AS medium versus. In contrast, in an established biofilm model in the AS medium, the efficacy of colistin was decreased. OligoG CF-5/20 (≥2%) treatment however, induced dose-dependent biofilm disruption (p<0.05), and led to colistin retaining its antimicrobial activity (p<0.05). Whilst circular dichroism indicated that OligoG CF-5/20 did not change the orientation of the alginate carboxyl groups, mass-spectrometry demonstrated that the oligomers induced dose-dependent (>0.2%; p<0.05) reductions in pseudomonal quorum sensing signaling. These findings reinforce the potential clinical significance of microcolony formation in the CF lung, and highlight a novel approach to treat MDR pseudomonal infections.

PMID: 28630204 [PubMed - as supplied by publisher]

Pseudomonas Quinolone Signal (PQS) Induces Oxidative Stress and inhibits Heme Oxygenase-1 Expression in Lung Epithelial Cells.

Infect Immun. 2017 Jun 19;:

Authors: Abdalla MY, Hoke T, Seravalli J, Switzer BL, Bavitz M, Fliege JD, Murphy PJ, Britigan BE

Abstract
Pseudomonas aeruginosa (PA) causes lung infection in patients with cystic fibrosis (CF). Pseudomonas Quinolone Signal (PQS) is a secreted PA virulence factor that contributes to the pathogenicity of PA. We were able to detect PQS in sputum samples from CF patients infected with PA, but not in samples from uninfected patients. We then tested the hypothesis that PQS induces oxidative stress in host cells by determining the ability of PQS to induce production of reactive oxygen species (ROS) in lung epithelial cells (A549 and primary normal human bronchial epithelial (NHBE)) and macrophages (J774A.1 and THP-1). ROS production induced by PQS was detected using fluorescent probes (dichloro-dihydro-fluorescein diacetate (DCF-DA), dihydroethidium (DHE), and MitoSOX Red) in conjunction with confocal microscopy and flow cytometry. PQS induced ROS production in lung epithelial cells (A549 and NHBE) and macrophages (J774A.1 and THP-1). NHBE cells were sensitive to as low as 500 ng/ml PQS. PQS significantly induced early apoptosis (p< 0.05, n =6) in lung epithelial cells, as measured by annexin/PI detection using flow cytometry. However, no change in apoptosis upon PQS treatment was seen with J774A.1 cells. Heme-oxygenase-1 protein (HO-1) is an anti-oxidant enzyme usually induced by oxidative stress. Interestingly, incubation with PQS significantly reduced HO-1 and NrF2 expression in A549 cells and NHBE cells, but increased HO-1 expression in J774A.1 cells (p<0.05, n=3), as determined by immunoblot and densitometry. These PQS effects on host cells could play an important role in the pathogenicity of PA infections.

PMID: 28630072 [PubMed - as supplied by publisher]

Chemistry and Biology of the Pyrrole-Imidazole Alkaloids.

Alkaloids Chem Biol. 2017;77:117-219

Authors: Lindel T

Abstract
More than a decade after our last review on the chemistry of the pyrrole-imidazole alkaloids, it was time to analyze once more the developments in that field. The comprehensive article focusses on the total syntheses of pyrrole-imidazole alkaloids that have appeared since 2005. The classic monomeric pyrrole-imidazole alkaloids have all been synthesized, sometimes primarily to demonstrate the usefulness of a new method, as in the case of the related molecules agelastatin A and cyclooroidin with more than 15 syntheses altogether. The phakellin skeleton has been made more than 10 times, too, with a focus on the target structure itself. Thus, some of the pyrrole-imidazole alkaloids are now available in gram amounts, and the supply problem has been solved. The total synthesis of the dimeric pyrrole-imidazole alkaloids is still mostly in its pioneering phase with two routes to palau'amine and massadine discovered and three routes to the axinellamines and ageliferin. In addition, the review summarizes recent discoveries regarding the biological activity of the pyrrole-imidazole alkaloids. Regarding the biosynthesis of sceptrin, a pathway is proposed that starts from nagelamide I and proceeds via two electrocyclizations and reduction.

PMID: 28212701 [PubMed - indexed for MEDLINE]

Prospective Endoscopic Ultrasound-Based Approach to the Evaluation of Idiopathic Pancreatitis: Causes, Response to Therapy, and Long-term Outcome.

Am J Gastroenterol. 2016 Sep;111(9):1339-48

Authors: Wilcox CM, Seay T, Kim H, Varadarajulu S

Abstract
OBJECTIVES: Although idiopathic pancreatitis is common, the natural history is not well studied, and the best diagnostic approach to both single and multiple attacks remains undefined.
METHODS: We prospectively evaluated patients with idiopathic pancreatitis over a 10-year period, and clinical information for each episode was reviewed. Endoscopic ultrasound (EUS) was performed in all patients. Patients with microlithiasis or bile duct stones were referred for cholecystectomy and endoscopic retrograde cholangiopancreatography (ERCP), respectively. For those with a single attack, if EUS was normal or chronic pancreatitis or pancreas divisum was diagnosed, the patient was followed up for recurrence. For those with multiple attacks and a negative EUS, ERCP and sphincter of Oddi manometry with endoscopic therapy as appropriate were recommended. All patients were followed up in the long term to evaluate for recurrent pancreatitis, the primary study end point.
RESULTS: Over the study period, 201 patients were identified (80 single attack, 121 multiple attacks; mean age 53 years, range 17-95 years, s.d. 16.3 years; and 53% female). After EUS, 54% of patients with a single attack were categorized as idiopathic, and for multiple attacks sphincter of Oddi dysfunction (SOD) was the most common diagnosis (41%). Long-term follow-up (median 37 months; interquartile range 19-70 months) documented recurrence of pancreatitis in 15 (24%; 95% confidence interval (CI), 15-38%) patients with a single attack and in 48 (49%; 95% CI, 38-62%) patients with multiple attacks. Despite endoscopic therapy, patients with pancreas divisum and SOD had relapse rates of 50% (95% CI, 35 to 68%) and 55% (95% CI, 31 to 82%), respectively.
CONCLUSIONS: Following a single idiopathic attack of pancreatitis and a negative EUS examination, relapse was infrequent. Despite endoscopic therapy, patients with multiple attacks, especially those attributed to pancreas divisum and SOD, had high rates of recurrence. EUS may be a useful, minimally invasive tool for the diagnostic evaluation of idiopathic pancreatitis. The study was listed in Clinicaltrials.gov NCT00609726.

PMID: 27325219 [PubMed - indexed for MEDLINE]

Gene correction in patient-specific iPSCs for therapy development and disease modeling.

Hum Genet. 2016 Sep;135(9):1041-58

Authors: Jang YY, Ye Z

Abstract
The discovery that mature cells can be reprogrammed to become pluripotent and the development of engineered endonucleases for enhancing genome editing are two of the most exciting and impactful technology advances in modern medicine and science. Human pluripotent stem cells have the potential to establish new model systems for studying human developmental biology and disease mechanisms. Gene correction in patient-specific iPSCs can also provide a novel source for autologous cell therapy. Although historically challenging, precise genome editing in human iPSCs is becoming more feasible with the development of new genome-editing tools, including ZFNs, TALENs, and CRISPR. iPSCs derived from patients of a variety of diseases have been edited to correct disease-associated mutations and to generate isogenic cell lines. After directed differentiation, many of the corrected iPSCs showed restored functionality and demonstrated their potential in cell replacement therapy. Genome-wide analyses of gene-corrected iPSCs have collectively demonstrated a high fidelity of the engineered endonucleases. Remaining challenges in clinical translation of these technologies include maintaining genome integrity of the iPSC clones and the differentiated cells. Given the rapid advances in genome-editing technologies, gene correction is no longer the bottleneck in developing iPSC-based gene and cell therapies; generating functional and transplantable cell types from iPSCs remains the biggest challenge needing to be addressed by the research field.

PMID: 27256364 [PubMed - indexed for MEDLINE]

ALPK3 GENE MUTATION IN A PATIENT WITH CONGENITAL CARDIOMYOPATHY AND DYSMORPHIC FEATURES.

Cold Spring Harb Mol Case Stud. 2017 Jun 19;:

Authors: Cağlayan AO, Sezer RG, Kaymakcalan H, Ulgen E, Yavuz T, Baranoski JF, Bozaykut A, Serin Harmanci A, Yalcin Y, Youngblood MW, Yasuno K, Bilguvar K, Gunel M

Abstract
Primary cardiomyopathy is one of the most common inherited cardiac diseases and harbors significant phenotypic and genetic heterogeneity. Because of this, genetic testing has become standard in treatment of this disease group. Indeed, in recent years, next-generation DNA sequencing has found broad applications in medicine, both as a routine diagnostic tool for genetic disorders and also as a high-throughput discovery tool for identifying novel disease causing genes. We describe a male infant with primary dilated cardiomyopathy that was diagnosed using intrauterine echocardiography, and found to progress to hypertrophic cardiomyopathy after birth. This proband was born to a non-consanguineous family with a past history of a male fetus that died due to cardiac abnormalities at 30 weeks of gestation. Using whole-exome sequencing, a novel homozygous frameshift mutation (c.2018delC; p.Gln675SerfsX30) in ALPK3 was identified and confirmed with Sanger sequencing. Heterozygous family members were normal with echocardiographic examination. To date, only two studies have reported homozygous pathogenic variants of ALPK3, with a total of seven affected individuals with cardiomyopathy from four unrelated consanguineous families. We include a discussion of the patient's phenotypic features and a review of relevant literature findings.

PMID: 28630369 [PubMed - as supplied by publisher]

Novel NBAS mutations and fever-related recurrent acute liver failure in Chinese children: a retrospective study.

BMC Gastroenterol. 2017 Jun 19;17(1):77

Authors: Li JQ, Qiu YL, Gong JY, Dou LM, Lu Y, Knisely AS, Zhang MH, Luan WS, Wang JS

Abstract
BACKGROUND: Underlying causes in Chinese children with recurrent acute liver failure (RALF), including liver crises less than full acute liver failure, are incompletely understood. We sought to address this by searching for genes mutated in such children.
METHODS: Five unrelated Chinese boys presenting between 2012 and 2015 with RALF of unexplained etiology were studied. Results of whole exome sequencing were screened for mutations in candidate genes. Mutations were verified in patients and their family members by Sanger sequencing. All 5 boys underwent liver biopsy.
RESULTS: NBAS was the only candidate gene mutated in more than one patient (biallelic mutations, 3 of 5 patients; 5 separate mutations). All NBAS mutations were novel and predictedly pathogenic (frameshift insertion mutation c.6611_6612insCA, missense mutations c.2407G > A and c.3596G > A, nonsense mutation c.586C > T, and splicing-site mutation c.5389 + 1G > T). Of these mutations, 3 lay in distal (C-terminal) regions of NBAS, a novel distribution. Unlike the 2 patients without NBAS mutations, the 3 patients with confirmed NBAS mutations all suffered from a febrile illness before each episode of liver crisis (fever-related RALF), with markedly elevated alanine aminotransferase and aspartate aminotransferase activities 24-72 h after elevation of body temperature, succeeded by severe coagulopathy and mild to moderate jaundice.
CONCLUSIONS: As in other countries, so too in China; NBAS disease is a major cause of fever-related RALF in children. The mutation spectrum of NBAS in Chinese children seems different from that described in other populations.

PMID: 28629372 [PubMed - in process]