Literature Watch
Prevalence and risk factors of Blastocystis infection among underprivileged communities in rural Malaysia.
Prevalence and risk factors of Blastocystis infection among underprivileged communities in rural Malaysia.
Asian Pac J Trop Med. 2017 May;10(5):491-497
Authors: Mohammad NA, Al-Mekhlafi HM, Moktar N, Anuar TS
Abstract
OBJECTIVES: To determine the prevalence and risk factors of Blastocystis among underprivileged communities living in rural Malaysia.
METHODS: This cross-sectional study was conducted among 253 participants aged between 1 and 85 years. Stool samples were examined using Wheatley's trichrome stain after in-vitro cultivation in Jones' medium to detect the presence of Blastocystis. Information pertaining to the demography, socioeconomic and environment were collected using pre-validated questionnaires.
RESULTS: The total prevalence of Blastocystis infection was 40.7%. The multiple logistic regression analysis revealed that age ≥15 years (OR = 2.72; 95% CI = 1.47-5.04) and presence of infected family members (OR = 8.56; 95% CI = 4.47-16.38) were the significant risk factors associated with blastocystosis in these communities.
CONCLUSIONS: Blastocystosis is revealed through this study to be still prevalent among Orang Asli communities in rural Malaysia. The two main approaches that should be implemented by the public health authority in battling this infection would be the screening of other family members and giving treatment to the infected individuals. Moreover, it is imperative for health education on good personal and food hygiene practices are provided in order to reduce the morbidity and transmission of Blastocystis infection among the Orang Asli in their communities meaningfully.
PMID: 28647187 [PubMed - in process]
Success of tardive electroconvulsive therapy sessions after loxapine-induced malignant syndrome in the context of very poor metabolisation.
Success of tardive electroconvulsive therapy sessions after loxapine-induced malignant syndrome in the context of very poor metabolisation.
Therapie. 2017 May 29;:
Authors: Descoeur J, Philibert L, Chalard K, Attal J, Petit P, Klouche K, Olivier M
Abstract
We report the success of tardive electroconvulsive therapy in a case of loxapine malignant syndrome with catatonia. Loxapine and its metabolites were measured in biological samples by liquid chromatography coupled to tandem mass spectrometry. Genes were studied by sequencing and quantitative polymerase chain reaction (PCR). Plasmatic drug concentrations showed a supratherapeutic concentration of loxapine with a very low 8-hydroxyloxapine/loxapine ratio (range from 0.32 to 0.66, normal value>2 for 100mg) and a very long elimination half-life of loxapine (half-life>140h, normal value from 1 to 4hours). We tried to explain this kinetics by exploring the main pharmacogenes implicated in the metabolism of loxapine. No genetic abnormality for CYP1A2 was observed. The study of associated treatments showed the potential contribution of valproate. Pharmacokinetics and pharmacogenetics investigations revealed a blockade of the CYP1A2 metabolic pathway without genetic abnormalities, probably due to valproate co-medication. Toxicological monitoring of loxapine and its metabolites helped to explain the persistence of symptoms and to adapt the therapeutic management.
PMID: 28647110 [PubMed - as supplied by publisher]
Advanced Cell Classifier: User-Friendly Machine-Learning-Based Software for Discovering Phenotypes in High-Content Imaging Data.
Advanced Cell Classifier: User-Friendly Machine-Learning-Based Software for Discovering Phenotypes in High-Content Imaging Data.
Cell Syst. 2017 Jun 16;:
Authors: Piccinini F, Balassa T, Szkalisity A, Molnar C, Paavolainen L, Kujala K, Buzas K, Sarazova M, Pietiainen V, Kutay U, Smith K, Horvath P
Abstract
High-content, imaging-based screens now routinely generate data on a scale that precludes manual verification and interrogation. Software applying machine learning has become an essential tool to automate analysis, but these methods require annotated examples to learn from. Efficiently exploring large datasets to find relevant examples remains a challenging bottleneck. Here, we present Advanced Cell Classifier (ACC), a graphical software package for phenotypic analysis that addresses these difficulties. ACC applies machine-learning and image-analysis methods to high-content data generated by large-scale, cell-based experiments. It features methods to mine microscopic image data, discover new phenotypes, and improve recognition performance. We demonstrate that these features substantially expedite the training process, successfully uncover rare phenotypes, and improve the accuracy of the analysis. ACC is extensively documented, designed to be user-friendly for researchers without machine-learning expertise, and distributed as a free open-source tool at www.cellclassifier.org.
PMID: 28647475 [PubMed - as supplied by publisher]
A first report of rare earth elements in northwestern Mediterranean seaweeds.
A first report of rare earth elements in northwestern Mediterranean seaweeds.
Mar Pollut Bull. 2017 Jun 21;:
Authors: Squadrone S, Brizio P, Battuello M, Nurra N, Sartor RM, Benedetto A, Pessani D, Abete MC
Abstract
The concentrations of rare earth elements (REE) were determined by ICP-MS in dominant seaweed species, collected from three locations of the northwestern Mediterranean Sea. This is the first study to define levels and patterns of REE in macro algae from these coastal areas. Rare elements are becoming emerging inorganic contaminants in marine ecosystems, due to their worldwide increasing applications in industry, technology, medicine and agriculture. Significant inter-site and interspecies differences were registered, with higher levels of REE in brown and green macro algae than in red seaweeds. Levels of light REE were also observed to be greater compared to heavy REE in all samples. One of the investigated locations (Bergeggi, SV) had higher REE and ΣREE concentrations, probably due to its proximity to an important commercial and touristic harbor, while the other two sites were less affected by anthropogenic contaminations, and showed comparable REE patterns and lower concentrations.
CAPSULE: Rare earth elements in seaweeds.
PMID: 28647152 [PubMed - as supplied by publisher]
A systematic review of pharmacogenetic studies on the response to biologics in psoriasis patients.
A systematic review of pharmacogenetic studies on the response to biologics in psoriasis patients.
Br J Dermatol. 2017 Jun 24;:
Authors: van Vugt LJ, van den Reek JMPA, Coenen MJH, de Jong EMGJ
Abstract
Biologics are indicated for treating moderate to severe psoriasis. As the number of biologics registered for psoriasis increases, so does the need for biomarkers to guide personalized therapeutic decisions. Genetic variants might serve as predictors for treatment response, a field of research known as pharmacogenetics. The aim of this systematic review was to assess which genetic variants are associated with the response to biologics in psoriasis patients. A systematic search was performed in EMBASE, MEDLINE, the Cochrane Library and Web of Science. Twenty-six papers were included in this systematic review: 24 original studies and two meta-analyses. Quality was assessed using a predesigned form. Risk of bias was assessed using the Newcastle-Ottawa Scale. The majority of studies reported a candidate gene approach, focusing on polymorphisms in genes related the therapeutical target or to psoriasis susceptibility. Studied populations were small and results were divergent, especially for studies investigating tumour necrosis factor inhibitors. The evidence for the role of HLA-Cw6 in ustekinumab efficacy shows minimal heterogeneity, with a higher response rate among HLA-Cw6 positive patients reported across three out of five studies. However, replication of these findings in larger cohorts is required. Large scale hypothesis-free searches for genetic biomarkers are needed to uncover the complete genetic background of biologics treatment outcome. This article is protected by copyright. All rights reserved.
PMID: 28646581 [PubMed - as supplied by publisher]
A Comprehensive Mouse Transcriptomic BodyMap across 17 Tissues by RNA-seq.
A Comprehensive Mouse Transcriptomic BodyMap across 17 Tissues by RNA-seq.
Sci Rep. 2017 Jun 23;7(1):4200
Authors: Li B, Qing T, Zhu J, Wen Z, Yu Y, Fukumura R, Zheng Y, Gondo Y, Shi L
Abstract
The mouse has been widely used as a model organism for studying human diseases and for evaluating drug safety and efficacy. Many diseases and drug effects exhibit tissue specificity that may be reflected by tissue-specific gene-expression profiles. Here we construct a comprehensive mouse transcriptomic BodyMap across 17 tissues of six-weeks old C57BL/6JJcl mice using RNA-seq. We find different expression patterns between protein-coding and non-coding genes. Liver expressed the least complex transcriptomes, that is, the smallest number of genes detected in liver across all 17 tissues, whereas testis and ovary harbor more complex transcriptomes than other tissues. We report a comprehensive list of tissue-specific genes across 17 tissues, along with a list of 4,781 housekeeping genes in mouse. In addition, we propose a list of 27 consistently and highly expressed genes that can be used as reference controls in expression-profiling analysis. Our study provides a unique resource of mouse gene-expression profiles, which is helpful for further biomedical research.
PMID: 28646208 [PubMed - in process]
Hyperpolarized helium-3 magnetic resonance lung imaging of non-sedated infants and young children: a proof-of-concept study.
Hyperpolarized helium-3 magnetic resonance lung imaging of non-sedated infants and young children: a proof-of-concept study.
Clin Imaging. 2017 May 10;45:105-110
Authors: Altes TA, Meyer CH, Mata JF, Froh DK, Paget-Brown A, Gerald Teague W, Fain SB, de Lange EE, Ruppert K, Botfield MC, Johnson MA, Mugler JP
Abstract
PURPOSE: To develop and evaluate a protocol for hyperpolarized helium-3 (HHe) ventilation magnetic resonance imaging (MRI) of the lungs of non-sedated infants and children.
MATERIALS AND METHODS: HHe ventilation MRI was performed on seven children ≤4years old. Contiguous 2D-spiral helium-3 images were acquired sequentially with a scan time of ≤0.2s/slice.
RESULTS: Motion-artifact-free, high signal-to-noise ratio (SNR) images of lung ventilation were obtained. Gas was homogeneously distributed in healthy individuals; focal ventilation defects were found in patients with respiratory diseases.
CONCLUSION: HHe ventilation MRI can aid assessment of pediatric lung disease even at a young age.
PMID: 28646735 [PubMed - as supplied by publisher]
Pregnancy outcome in women with cystic fibrosis related diabetes.
Pregnancy outcome in women with cystic fibrosis related diabetes.
Acta Obstet Gynecol Scand. 2017 Jun 24;:
Authors: Reynaud Q, Poupon-Bourdy S, Rabilloud M, Al Mufti L, Jablonski CR, Lemonnier L, Nove-Josserand R, Touzet S, Durieu I, French Cystic Fibrosis Registry
Abstract
INTRODUCTION: With increasing life expectancy more women with cystic fibrosis and diabetes mellitus become pregnant. We investigated how pre-gestational diabetes (cystic fibrosis related diabetes) influenced pregnancy outcome and the clinical status of these women MATERIAL AND METHODS: We analyzed all pregnancies reported to the French cystic fibrosis registry between 2001 and 2012, and compared forced expiratory volume (FEV1 ) and body mass index before and after pregnancy in women with and without pre-gestational diabetes having a first delivery RESULTS: A total 249 women delivered 314 infants. Among these, 189 women had a first delivery and 29 of these had pre-gestational diabetes. There was a trend towards a higher rate of assisted conception among diabetic women (53.8%) as compared to non-diabetic women (34.5%, p=0.06), and the rate of cesarean section was significantly higher in diabetic women (48% versus 21.4%, p=0.005). The rate of preterm birth and mean infant birth weight did not differ significantly between diabetic and non-diabetic women. Before pregnancy forced expiratory volume was significantly lower in the diabetic group. The decline in forced expiratory volume and body mass index following pregnancy did not differ between the women with and without pre-gestational diabetes CONCLUSION: Pre-gestational diabetes in cystic fibrosis women is associated with a higher rate of cesarean section, but does not seem to have a clinically significant impact on fetal growth or preterm delivery. The changes in maternal pulmonary and nutritional status following pregnancy in cystic fibrosis women were not influenced by pre-gestational diabetes. This article is protected by copyright. All rights reserved.
PMID: 28646623 [PubMed - as supplied by publisher]
Increased Soluble VCAM-1 and Normal P-Selectin in Cystic Fibrosis: a Cross-Sectional Study.
Increased Soluble VCAM-1 and Normal P-Selectin in Cystic Fibrosis: a Cross-Sectional Study.
Lung. 2017 Jun 23;:
Authors: Nowak JK, Wojsyk-Banaszak I, Mądry E, Wykrętowicz A, Krzyżanowska P, Drzymała-Czyż S, Nowicka A, Pogorzelski A, Sapiejka E, Skorupa W, Szczepanik M, Lisowska A, Walkowiak J
Abstract
PURPOSE: As life expectancy in cystic fibrosis (CF) increases, questions regarding its potential impact on cardiovascular health arise. Soluble vascular cell adhesion molecule 1 (sVCAM-1), P-selectin (sP-selectin) are proposed as biomarkers of cardiovascular disease. We aimed to: compare their concentrations in clinically stable CF patients and healthy subjects (HS) and verify whether they independently correlate with CF characteristics.
METHODS: Serum sVCAM-1 and sP-selectin levels were measured using ELISA. CF was characterized using: forced expiratory volume in 1 s, exocrine pancreatic and CF-related liver disease status, Pseudomonas aeruginosa colonization, serum high-sensitivity C-reactive protein, and body mass index (BMI). CFTR genotypes were classified as severe (classes I and II) or other.
RESULTS: 108 CF patients and 51 healthy subjects volunteered for the study. In the CF group BMI was lower (median [IQR]: 20.5 kg/m(2) [18.4-22.2] vs. 21.6 kg/m(2) [19.9-23.4], p = 0.02) and hsCRP levels were higher (3.6 mg/L [1.1-7.1] vs. 0.5 mg/dL [0.3-1.0], p < 10(-10)). While sVCAM-1 concentrations were greater in CF patients (1018 ng/mL [851-1279] vs. 861 ng/mL [806-979], p < 10(-4)), sP-selectin levels did not differ (155 ng/mL [129-188] vs. 156 ng/mL [144-177], p = 0.48). None of the multivariable regression models was valid for the prediction of sVCAM-1 and sP-selectin in CF.
CONCLUSIONS: We found higher sVCAM-1 concentrations in CF patients than in healthy subjects, which were not explained by CF characteristics. Further research is required to check whether sVCAM-1 is a marker of microangiopathy in CF.
PMID: 28646244 [PubMed - as supplied by publisher]
Secretory IgA response against Pseudomonas aeruginosa in the upper airways and the link with chronic lung infection in cystic fibrosis.
Secretory IgA response against Pseudomonas aeruginosa in the upper airways and the link with chronic lung infection in cystic fibrosis.
Pathog Dis. 2017 Jun 22;:
Authors: Mauch R, Rossi C, Aiello T, Ribeiro J, Ribeiro A, Høiby N, Levy C
Abstract
We assessed the diagnostic ability of an ELISA test for measurement of specific secretory IgA (sIgA) in saliva to identify Cystic Fibrosis (CF) patients with P. aeruginosa chronic lung infection and intermittent lung colonization. A total of 102 Brazilian CF patients and 53 healthy controls were included. Specific serum IgG response was used as a surrogate to distinguish CF patients according to their P. aeruginosa colonization/infection status. The rate of sIgA positivity was 87.1% in CF chronically infected patients (Median value = 181.5 U/mL), 48.7% in intermittently colonized patients (Median value = 45.8 U/mL) and 21.8% in free of infection patients (Median value = 22.1 U/mL). SIgA levels in saliva were significantly associated with serum P. aeruginosa IgG and microbiological culture results. The sensitivity, specificity, PPV and NPV for differentiation between presence and absence of chronic lung infection were 87%, 63%, 51% and 92%. Measurement of sIgA in saliva may be used for screening patients in risk of developing P. aeruginosa chronic lung infection in CF and possibly also for paranasal sinusitis, and, most importantly, to efficiently rule out chronic P. aeruginosa lung infection.
PMID: 28645157 [PubMed - as supplied by publisher]
Genotype-phenotype evaluation of MED13L defects in the light of a novel truncating and a recurrent missense mutation.
Genotype-phenotype evaluation of MED13L defects in the light of a novel truncating and a recurrent missense mutation.
Eur J Med Genet. 2017 Jun 20;:
Authors: Asadollahi R, Zweier M, Gogoll L, Schiffmann R, Sticht H, Steindl K, Rauch A
Abstract
A decade after the designation of MED13L as a gene and its link to intellectual disability (ID) and dextro-looped transposition of great arteries in 2003, we previously described a recognizable syndrome due to MED13L haploinsufficiency. Subsequent reports of 22 further patients diagnosed by genome-wide testing further delineated the syndrome with expansion of the phenotypic spectrum and showed reduced penetrance for congenital heart defects. We now report two novel patients identified by whole exome sequencing, one with a de novo MED13L truncating mutation and the other with a de novo missense mutation. The first patient indicates some facial resemblance to Kleefstra syndrome as a novel differential diagnosis, and the second patient shows, for the first time, recurrence of a MED13L missense mutation (p.(Asp860Gly)). Notably, our in silico modelling predicted this missense mutation to decrease the stability of an alpha-helix and thereby affecting the MED13L secondary structure, while the majority of published missense mutations remain variants of uncertain significance. Review of the reported patients with MED13L haploinsufficiency indicates moderate to severe ID and facial anomalies in all patients, as well as severe speech delay and muscular hypotonia in the majority. Further common signs include abnormal MRI findings of myelination defects and abnormal corpus callosum, ataxia and coordination problems, autistic features, seizures/abnormal EEG, or congenital heart defects, present in about 20-50% of the patients. With reference to facial anomalies, the majority of patients were reported to show broad/prominent forehead, low set ears, bitemporal narrowing, upslanting palpebral fissures, depressed/flat nasal bridge, bulbous nose, and abnormal chin, but macroglossia and horizontal eyebrows were also observed in ∼30%. The latter are especially important in the differential diagnosis of 1p36 deletion and Kleefstra syndromes, while the more common facial gestalt shows some resemblance to 22q11.2 deletion syndrome. Despite the fact that MED13L was found to be one of the most common ID genes in the Deciphering Developmental Disorders Study, further detailed patient descriptions are needed to explore the full clinical spectrum, potential genotype-phenotype correlations, as well as the role of missense mutations and potential mutational hotspots along the gene.
PMID: 28645799 [PubMed - as supplied by publisher]
Defective mitochondrial RNA processing due to PNPT1 variants causes Leigh syndrome.
Defective mitochondrial RNA processing due to PNPT1 variants causes Leigh syndrome.
Hum Mol Genet. 2017 Jun 22;:
Authors: Matilainen S, Carroll CJ, Richter U, Euro L, Pohjanpelto M, Paetau A, Isohanni P, Suomalainen A
Abstract
Leigh syndrome is a severe infantile encephalopathy with an exceptionally variable genetic background. We studied the exome of a child manifesting with Leigh syndrome at one month of age and progressing to death by the age of 2.4 years, and identified novel compound heterozygous variants in PNPT1, encoding the polynucleotide phosphorylase (PNPase). Expression of the wild type PNPT1 in the subject's myoblasts functionally complemented the defects, and the pathogenicity was further supported by structural predictions and protein and RNA analyses. PNPase is a key enzyme in mitochondrial RNA metabolism, with suggested roles in mitochondrial RNA import and degradation. The variants were predicted to locate in the PNPase active site and disturb the RNA processing activity of the enzyme. The PNPase trimer formation was not affected, but specific RNA processing intermediates derived from mitochondrial transcripts of the ND6 subunit of Complex I, as well as small mRNA fragments, accumulated in the subject's myoblasts. Mitochondrial RNA processing mediated by the degradosome consisting of hSUV3 and PNPase is poorly characterized, and controversy on the role and location of PNPase within human mitochondria exists. Our evidence indicates that PNPase activity is essential for correct maturation of the ND6 transcripts, and likely for the efficient removal of degradation intermediates. Loss of its activity will result in combined respiratory chain deficiency, and a classic respiratory chain-deficiency-associated disease, Leigh syndrome, indicating an essential role for the enzyme for normal function of the mitochondrial respiratory chain.
PMID: 28645153 [PubMed - as supplied by publisher]
CRISPR/Cas9-mediated genome editing via postnatal administration of AAV vector cures haemophilia B mice.
CRISPR/Cas9-mediated genome editing via postnatal administration of AAV vector cures haemophilia B mice.
Sci Rep. 2017 Jun 23;7(1):4159
Authors: Ohmori T, Nagao Y, Mizukami H, Sakata A, Muramatsu SI, Ozawa K, Tominaga SI, Hanazono Y, Nishimura S, Nureki O, Sakata Y
Abstract
Haemophilia B, a congenital haemorrhagic disease caused by mutations in coagulation factor IX gene (F9), is considered an appropriate target for genome editing technology. Here, we describe treatment strategies for haemophilia B mice using the clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 system. Administration of adeno-associated virus (AAV) 8 vector harbouring Staphylococcus aureus Cas9 (SaCas9) and single guide RNA (sgRNA) to wild-type adult mice induced a double-strand break (DSB) at the target site of F9 in hepatocytes, sufficiently developing haemophilia B. Mutation-specific gene editing by simultaneous induction of homology-directed repair (HDR) sufficiently increased FIX levels to correct the disease phenotype. Insertion of F9 cDNA into the intron more efficiently restored haemostasis via both processes of non-homologous end-joining (NHEJ) and HDR following DSB. Notably, these therapies also cured neonate mice with haemophilia, which cannot be achieved with conventional gene therapy with AAV vector. Ongoing haemophilia therapy targeting the antithrombin gene with antisense oligonucleotide could be replaced by SaCas9/sgRNA-expressing AAV8 vector. Our results suggest that CRISPR/Cas9-mediated genome editing using an AAV8 vector provides a flexible approach to induce DSB at target genes in hepatocytes and could be a good strategy for haemophilia gene therapy.
PMID: 28646206 [PubMed - in process]
Dacomitinib, a pan-inhibitor of ErbB receptors, suppresses growth and invasive capacity of chemoresistant ovarian carcinoma cells.
Dacomitinib, a pan-inhibitor of ErbB receptors, suppresses growth and invasive capacity of chemoresistant ovarian carcinoma cells.
Sci Rep. 2017 Jun 23;7(1):4204
Authors: Momeny M, Zarrinrad G, Moghaddaskho F, Poursheikhani A, Sankanian G, Zaghal A, Mirshahvaladi S, Esmaeili F, Eyvani H, Barghi F, Sabourinejad Z, Alishahi Z, Yousefi H, Ghasemi R, Dardaei L, Bashash D, Chahardouli B, Dehpour AR, Tavakkoly-Bazzaz J, Alimoghaddam K, Ghavamzadeh A, Ghaffari SH
Abstract
Epithelial ovarian cancer (EOC) is the most lethal gynaecological malignancy worldwide. Development of chemoresistance and peritoneal dissemination of EOC cells are the major reasons for low survival rate. Targeting signal transduction pathways which promote therapy resistance and metastatic dissemination is the key to successful treatment. Members of the ErbB family of receptors are over-expressed in EOC and play key roles in chemoresistance and invasiveness. Despite this, single-targeted ErbB inhibitors have demonstrated limited activity in chemoresistant EOC. In this report, we show that dacomitinib, a pan-ErbB receptor inhibitor, diminished growth, clonogenic potential, anoikis resistance and induced apoptotic cell death in therapy-resistant EOC cells. Dacominitib inhibited PLK1-FOXM1 signalling pathway and its down-stream targets Aurora kinase B and survivin. Moreover, dacomitinib attenuated migration and invasion of the EOC cells and reduced expression of epithelial-to-mesenchymal transition (EMT) markers ZEB1, ZEB2 and CDH2 (which encodes N-cadherin). Conversely, the anti-tumour activity of single-targeted ErbB agents including cetuximab (a ligand-blocking anti-EGFR mAb), transtuzumab (anti-HER2 mAb), H3.105.5 (anti-HER3 mAb) and erlotinib (EGFR small-molecule tyrosine kinase inhibitor) were marginal. Our results provide a rationale for further investigation on the therapeutic potential of dacomitinib in treatment of the chemoresistant EOC.
PMID: 28646172 [PubMed - in process]
CRISPR-Cas12a-assisted recombineering in bacteria.
CRISPR-Cas12a-assisted recombineering in bacteria.
Appl Environ Microbiol. 2017 Jun 23;:
Authors: Yan MY, Yan HQ, Ren GX, Zhao JP, Guo XP, Sun YC
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR)-Cas12a (Cpf1) has emerged as an effective genome editing tool in many organisms. Here, we developed and optimized a CRISPR-Cas12a assisted recombineering system to facilitate genetic manipulation in bacteria. Using this system, point mutations, deletions, insertions, and gene replacements can be easily generated on the chromosome or native plasmids in Escherichia coli, Yersinia pestis, and Mycobacterium smegmatis Because CRISPR-Cas12a-assisted recombineering does not require introduction of an antibiotic resistance gene into the chromosome to select for recombinants, it is an efficient approach for generating markerless and scarless mutations in bacteria.IMPORTANCE The CRISPR-Cas9 system has been widely used to facilitate genome editing in many bacteria. CRISPR-Cas12a (Cpf1), a new type of CRISPR-cas system, allows efficient genome editing in bacteria when combined with recombineering. Cas12a and Cas9 recognize different target sites, which allows for more precise selection of the cleavage target and introduction of the desired mutation. In addition, CRISPR-Cas12a assisted recombineering can be used for genetic manipulation of plasmids and plasmid curing. Finally, Cas12a-assisted recombineering in generating of point mutation, deletion, insertion and replacement in bacteria has been systematically analyzed. Taken together, our findings will guide efficient Cas12a-mediated genome editing in bacteria.
PMID: 28646112 [PubMed - as supplied by publisher]
MCAM mediates chemoresistance in small cell lung cancer via the PI3K/AKT/SOX2 signaling pathway.
MCAM mediates chemoresistance in small cell lung cancer via the PI3K/AKT/SOX2 signaling pathway.
Cancer Res. 2017 Jun 23;:
Authors: Tripathi SC, Fahrmann JF, Celiktas M, Aguilar M, Marini KD, Jolly MK, Katayama H, Wang H, Murage EN, Dennison JB, Watkins DN, Levine H, Ostrin EJ, Taguchi A, Hanash SM
Abstract
Despite favorable responses to initial therapy, small cell lung cancer (SCLC) relapse occurs within a year and exhibits resistance to multiple drugs. Due to limited accessibility of patient tissues for research purposes, SCLC-patient derived xenografts (PDX) have provided the best opportunity to address this limitation. Here we sought to identify novel mechanisms involved in SCLC chemoresistance. Through in-depth proteomic profiling, we identified MCAM as a markedly upregulated surface receptor in chemoresistant SCLC cell lines and in chemoresistant PDX compared to matched treatment-naïve tumors. MCAM depletion in chemoresistant cells reduced cell proliferation and reduced the IC50 inhibitory concentration of chemotherapeutic drugs in vitro. This MCAM-mediated sensitization to chemotherapy occurred via SOX2-dependent upregulation of mitochondrial 37S ribosomal protein 1/ATP binding cassette subfamily C member 1 (MRP1/ABCC1) and the PI3/AKT pathway. Metabolomic profiling revealed that MCAM modulated lactate production in chemoresistant cells that exhibit a distinct metabolic phenotype characterized by low oxidative phosphorylation. Our results suggest that MCAM may serve as a novel therapeutic target to overcome chemoresistance in SCLC.
PMID: 28646020 [PubMed - as supplied by publisher]
A rapid and quantitative method to detect human circulating tumor cells in a preclinical animal model.
A rapid and quantitative method to detect human circulating tumor cells in a preclinical animal model.
BMC Cancer. 2017 Jun 23;17(1):440
Authors: Tu SH, Hsieh YC, Huang LC, Lin CY, Hsu KW, Hsieh WS, Chi WM, Lee CH
Abstract
BACKGROUND: As cancer metastasis is the deadliest aspect of cancer, causing 90% of human deaths, evaluating the molecular mechanisms underlying this process is the major interest to those in the drug development field. Both therapeutic target identification and proof-of-concept experimentation in anti-cancer drug development require appropriate animal models, such as xenograft tumor transplantation in transgenic and knockout mice. In the progression of cancer metastasis, circulating tumor cells (CTCs) are the most critical factor in determining the prognosis of cancer patients. Several studies have demonstrated that measuring CTC-specific markers in a clinical setting (e.g., flow cytometry) can provide a current status of cancer development in patients. However, this useful technique has rarely been applied in the real-time monitoring of CTCs in preclinical animal models.
METHODS: In this study, we designed a rapid and reliable detection method by combining a bioluminescent in vivo imaging system (IVIS) and quantitative polymerase chain reaction (QPCR)-based analysis to measure CTCs in animal blood. Using the IVIS Spectrum CT System with 3D-imaging on orthotropic-developed breast-tumor-bearing mice.
RESULTS: In this manuscript, we established a quick and reliable method for measuring CTCs in a preclinical animal mode. The key to this technique is the use of specific human and mouse GUS primers on DNA/RNA of mouse peripheral blood under an absolute qPCR system. First, the high sensitivity of cancer cell detection on IVIS was presented by measuring the luciferase carried MDA-MB-231 cells from 5 to 5x10(11) cell numbers with great correlation (R(2) = 0.999). Next, the MDA-MB-231 cell numbers injected by tail vein and their IVIS radiance signals were strongly corrected with qPCR-calculated copy numbers (R(2) > 0.99). Furthermore, by applying an orthotropic implantation animal model, we successfully distinguished xenograft tumor-bearing mice and control mice with a significant difference (p < 0.001), whereas IVIS Spectrum-CT 3D-visualization showed that blood of mice with lung metastasis contained more than twice the CTC numbers than ordinary tumor-bearing mice. We demonstrated a positive correlation between lung metastasis status and CTC numbers in peripheral mouse blood.
CONCLUSION: Collectively, the techniques developed for this study resulted in the integration of CTC assessments into preclinical models both in vivo and ex vivo, which will facilitate translational targeted therapy in clinical practice.
PMID: 28645267 [PubMed - in process]
Molecular cloning, structure, phylogeny and expression analysis of the invertase gene family in sugarcane.
Molecular cloning, structure, phylogeny and expression analysis of the invertase gene family in sugarcane.
BMC Plant Biol. 2017 Jun 23;17(1):109
Authors: Wang L, Zheng Y, Ding S, Zhang Q, Chen Y, Zhang J
Abstract
BACKGROUND: Invertases (INVs) are key enzymes regulating sucrose metabolism and are here revealed to be involved in responses to environmental stress in plants. To date, individual members of the invertase gene family and their expression patterns are unknown in sugarcane due to its complex genome despite their significance in sucrose metabolism.
RESULTS: In this study, based on comparative genomics, eleven cDNA and twelve DNA sequences belonging to 14 non-redundant members of the invertase gene family were successfully cloned from sugarcane. A comprehensive analysis of the invertase gene family was carried out, including gene structures, phylogenetic relationships, functional domains, conserved motifs of proteins. The results revealed that the 14 invertase members from sugarcane could be clustered into three subfamilies, including 6 neutral/alkaline invertases (ShN/AINVs), and 8 acid invertases (ShAINVs). Faster divergence occurred in acid INVs than in neutral/alkaline INVs after the split of sugarcane and sorghum. At least a one-time gene duplication event was observed to have occurred in the four groups of acid INVs, whereas ShN/AINV1 and ShN/AINV2 in the β8 lineage were revealed to be the most recently duplicated genes among their paralogous genes in the β group of N/AINVs. Furthermore, comprehensive expression analysis of these genes was performed in sugarcane seedlings subjected to five abiotic stresses (drought, low temperature, glucose, fructose, and sucrose) using Quantitative Real-time PCR. The results suggested a functional divergence of INVs and their potential role in response to the five different treatments. Enzymatic activity in sugarcane seedlings was detected under five abiotic stresses treatments, and showed that the activities of all INVs were significantly inhibited in response to five different abiotic stresses, and that the neutral/alkaline INVs played a more prominent role in abiotic stresses than the acid INVs.
CONCLUSIONS: In this study, we determined the INV gene family members of sugarcane by PCR cloning using sorghum as a reference, providing the first study of the INV gene family in sugarcane. Combining existing INV gene data from 7 plants with a comparative approach including a series of comprehensive analyses to isolate and identify INV gene family members proved to be highly successful. Moreover, the expression levels of INV genes and the variation of enzymatic activities associated with drought, low temperature, glucose, fructose, and sucrose are reported in sugarcane for the first time. The results offered useful foundation and framework for future research for understanding the physiological roles of INVs for sucrose accumulation in sugarcane.
PMID: 28645264 [PubMed - in process]
Spatially resolved metabolic analysis reveals a central role for transcriptional control in carbon allocation to wood.
Spatially resolved metabolic analysis reveals a central role for transcriptional control in carbon allocation to wood.
J Exp Bot. 2017 Jun 22;:
Authors: Roach M, Arrivault S, Mahboubi A, Krohn N, Sulpice R, Stitt M, Niittylä T
Abstract
The contribution of transcriptional and post-transcriptional regulation to modifying carbon allocation to developing wood of trees is not well defined. To clarify the role of transcriptional regulation, the enzyme activity patterns of eight central primary metabolism enzymes across phloem, cambium, and developing wood of aspen (Populus tremula L.) were compared with transcript levels obtained by RNA sequencing of sequential stem sections from the same trees. Enzymes were selected on the basis of their importance in sugar metabolism and in linking primary metabolism to lignin biosynthesis. Existing enzyme assays were adapted to allow measurements from ~1 mm3 sections of dissected stem tissue. These experiments provided high spatial resolution of enzyme activity changes across different stages of wood development, and identified the gene transcripts probably responsible for these changes. In most cases, there was a clear positive relationship between transcripts and enzyme activity. During secondary cell wall formation, the increases in transcript levels and enzyme activities also matched with increased levels of glucose, fructose, hexose phosphates, and UDP-glucose, emphasizing an important role for transcriptional regulation in carbon allocation to developing aspen wood. These observations corroborate the efforts to increase carbon allocation to wood by engineering gene regulatory networks.
PMID: 28645173 [PubMed - as supplied by publisher]
Genomic Characterization of Two Novel SAR11 Isolates From the Red Sea, Including the First Strain of the SAR11 Ib clade.
Genomic Characterization of Two Novel SAR11 Isolates From the Red Sea, Including the First Strain of the SAR11 Ib clade.
FEMS Microbiol Ecol. 2017 Jun 22;:
Authors: Jimenez-Infante F, Ngugi DK, Vinu M, Blom J, Alam I, Bajic VB, Stingl U
Abstract
The SAR11 clade (Pelagibacterales) is a diverse group that forms a monophyletic clade within the Alphaproteobacteria, and constitutes up to one third of all prokaryotic cells in the photic zone of most oceans. Pelagibacterales are very abundant in the warm and highly saline surface waters of the Red Sea, raising the question of adaptive traits of SAR11 populations in this water body and warmer oceans through the world. In this study, two pure cultures were successfully obtained from surface waters on the Red Sea, one isolate of subgroup Ia and one of the previously uncultured SAR11 Ib lineage. The novel genomes were very similar to each other and to genomes of isolates of SAR11 subgroup Ia (Ia pan-genome), both in terms of gene content and synteny. Among the genes that were not present in the Ia pan-genome, 108 (RS39, Ia) and 151 genes (RS40, Ib) were strain-specific. Detailed analyses showed that only 51 (RS39, Ia) and 55 (RS40, Ib) of these strain-specific genes had not reported before on genome fragments of Pelagibacterales. Further analyses revealed the potential production of phosphonates by some SAR11 members and possible adaptations for oligotrophic life, including pentose sugar utilization and adhesion to marine particulate matter.
PMID: 28645159 [PubMed - as supplied by publisher]
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