Displaying publications 21 - 33 of 33 in total

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  1. Low JZB, Khang TF, Tammi MT
    BMC Bioinformatics, 2017 12 28;18(Suppl 16):575.
    PMID: 29297307 DOI: 10.1186/s12859-017-1974-4
    BACKGROUND: In current statistical methods for calling differentially expressed genes in RNA-Seq experiments, the assumption is that an adjusted observed gene count represents an unknown true gene count. This adjustment usually consists of a normalization step to account for heterogeneous sample library sizes, and then the resulting normalized gene counts are used as input for parametric or non-parametric differential gene expression tests. A distribution of true gene counts, each with a different probability, can result in the same observed gene count. Importantly, sequencing coverage information is currently not explicitly incorporated into any of the statistical models used for RNA-Seq analysis.

    RESULTS: We developed a fast Bayesian method which uses the sequencing coverage information determined from the concentration of an RNA sample to estimate the posterior distribution of a true gene count. Our method has better or comparable performance compared to NOISeq and GFOLD, according to the results from simulations and experiments with real unreplicated data. We incorporated a previously unused sequencing coverage parameter into a procedure for differential gene expression analysis with RNA-Seq data.

    CONCLUSIONS: Our results suggest that our method can be used to overcome analytical bottlenecks in experiments with limited number of replicates and low sequencing coverage. The method is implemented in CORNAS (Coverage-dependent RNA-Seq), and is available at https://github.com/joel-lzb/CORNAS .

    Matched MeSH terms: RNA/genetics
  2. Mohd-Zin SW, Abdullah NL, Abdullah A, Greene ND, Cheah PS, Ling KH, et al.
    Genome, 2016 Jul;59(7):439-48.
    PMID: 27373307 DOI: 10.1139/gen-2015-0142
    The EphA4 receptor tyrosine kinase is involved in numerous cell-signalling activities during embryonic development. EphA4 has the ability to bind to both types of ephrin ligands, the ephrinAs and ephrinBs. The C57BL/6J-Epha4rb-2J/GrsrJ strain, denoted Epha4(rb-2J/rb-2J), is a spontaneous mouse mutant that arose at The Jackson Laboratory. These mutants exhibited a synchronous hind limb locomotion defect or "hopping gait" phenotype, which is also characteristic of EphA4 null mice. Genetic complementation experiments suggested that Epha4(rb-2J) corresponds to an allele of EphA4, but details of the genomic defect in this mouse mutant are currently unavailable. We found a single base-pair deletion in exon 9 resulting in a frame shift mutation that subsequently resulted in a premature stop codon. Analysis of the predicted structure of the truncated protein suggests that both the kinase and sterile α motif (SAM) domains are absent. Definitive determination of genotype is needed for experimental studies of mice carrying the Epha4(rb-2J) allele, and we have also developed a method to ease detection of the mutation through RFLP. Eph-ephrin family members are reportedly expressed as numerous isoforms. Hence, delineation of the specific mutation in EphA4 in this strain is important for further functional studies, such as protein-protein interactions, immunostaining and gene compensatory studies, investigating the mechanism underlying the effects of altered function of Eph family of receptor tyrosine kinases on phenotype.
    Matched MeSH terms: RNA/genetics
  3. Mohamad Ashari ZS, Sulong S, Hassan R, Husin A, Sim GA, Abdul Wahid SF
    Asian Pac J Cancer Prev, 2014;15(4):1863-9.
    PMID: 24641422
    The amplification of telomerase component (TERC) gene could play an important role in generation and treatment of haematological malignancies. This present study was aimed to investigate copy number amplification status of TERC gene in chronic myeloid leukaemia (CML) patients who were being treated with imatinib mesylate (IM). Genomic DNA was extracted from peripheral blood of CML-IM Resistant (n=63), CML-IM Respond (n=63) and healthy individuals (n=30). TERC gene copy number predicted (CNP) and copy number calculated (CNC) were determined based on Taqman® Copy Number Assay. Fluorescence in situ hybridization (FISH) analysis was performed to confirm the normal signal pattern in C4 (calibrator) for TERC gene. Nine of CML patients showed TERC gene amplification (CNP=3), others had 2 CNP. A total of 17 CML patients expressed CNC>2.31 and the rest had 2.31>CNC>1.5. TERC gene CNP value in healthy individuals was 2 and their CNC value showed in range 1.59-2.31. The average CNC TERC gene copy number was 2.07, 1.99 and 1.94 in CML- IM Resistant patients, CML-IM Respond and healthy groups, respectively. No significant difference of TERC gene amplification observed between CML-IM Resistant and CML-IM Respond patients. Low levels of TERC gene amplification might not have a huge impact in haematological disorders especially in terms of resistance towards IM treatment.
    Matched MeSH terms: RNA/genetics*
  4. Khoo CK, Abdul-Murad AM, Kua BC, Mohd-Adnan A
    Fish Shellfish Immunol, 2012 Oct;33(4):788-94.
    PMID: 22842150 DOI: 10.1016/j.fsi.2012.07.005
    Cryptocaryoniasis (also known as marine white spot disease) is mediated by Cryptocaryon irritans. This obligate ectoparasitic protozoan infects virtually all marine teleosts, which includes Lates calcarifer, a highly valuable aquaculture species. Little is known about L. calcarifer-C. irritans interactions. This study was undertaken to gain an informative snapshot of the L. calcarifer transcriptomic response over the course of C. irritans infection. An in-house fabricated cDNA microarray slides containing 3872 probes from L. calcarifer liver and spleen cDNA libraries were used as a tool to investigate the response of L. calcarifer to C. irritans infection. Juvenile fish were infected with parasites for four days, and total RNA was extracted from liver tissue, which was harvested daily. We compared the transcriptomes of C. irritans-infected liver to uninfected liver over an infection period of four days; the comparison was used to identify the genes with altered expression levels in response to C. irritans infection. The greatest number of infection-modulated genes was recorded at 2 and 3 days post-infection. These genes were mainly associated with the immune response and were associated in particular with the acute phase response. Acute phase proteins such as hepcidin, C-type lectin and serum amyloid A are among the highly modulated genes. Our results indicate that an induced acute phase response in L. calcarifer toward C. irritans infection is similar to the responses observed in bacterial infections of teleosts. This response demonstrates the importance of first line defenses in teleost innate immune responses against ectoparasite infection.
    Matched MeSH terms: RNA/genetics
  5. Intapan PM, Chotmongkol V, Tantrawatpan C, Sanpool O, Morakote N, Maleewong W
    Am J Trop Med Hyg, 2011 Jun;84(6):994-7.
    PMID: 21633039 DOI: 10.4269/ajtmh.2011.10-0675
    Previously, we reported the presence of imported trichinellosis in a Thai worker returning from Malaysia, who presented with progressive generalized muscle hypertrophy and weakness after eating wild boar meat. This work analyzed a partial small subunit of a mitochondrial ribosomal RNA gene of Trichinella larvae isolated from the patient. The results showed complete identity with a mitochondrial RNA gene of Trichinella papuae (GenBank accession no. EF517130). This is the first report of imported trichinellosis in Thailand caused by T. papuae. It is possible that T. papuae is widely distributed in the wildlife of Southeast Asia.
    Matched MeSH terms: RNA/genetics
  6. Ruszymah BH, Lokman BS, Asma A, Munirah S, Chua K, Mazlyzam AL, et al.
    Int J Pediatr Otorhinolaryngol, 2007 Aug;71(8):1225-34.
    PMID: 17531328
    This study was aimed at regenerating autologous elastic cartilage for future use in pediatric ear reconstruction surgery. Specific attentions were to characterize pediatric auricular chondrocyte growth in a combination culture medium and to assess the possibility of elastic cartilage regeneration using human fibrin.
    Matched MeSH terms: RNA/genetics
  7. Ng WL, Marinov GK, Liau ES, Lam YL, Lim YY, Ea CK
    RNA Biol, 2016 09;13(9):861-71.
    PMID: 27362560 DOI: 10.1080/15476286.2016.1207036
    Circular RNAs (circRNAs) constitute a large class of RNA species formed by the back-splicing of co-linear exons, often within protein-coding transcripts. Despite much progress in the field, it remains elusive whether the majority of circRNAs are merely aberrant splicing by-products with unknown functions, or their production is spatially and temporally regulated to carry out specific biological functions. To date, the majority of circRNAs have been cataloged in resting cells. Here, we identify an LPS-inducible circRNA: mcircRasGEF1B, which is predominantly localized in cytoplasm, shows cell-type specific expression, and has a human homolog with similar properties, hcircRasGEF1B. We show that knockdown of the expression of mcircRasGEF1B reduces LPS-induced ICAM-1 expression. Additionally, we demonstrate that mcircRasGEF1B regulates the stability of mature ICAM-1 mRNAs. These findings expand the inventory of functionally characterized circRNAs with a novel RNA species that may play a critical role in fine-tuning immune responses and protecting cells against microbial infection.
    Matched MeSH terms: RNA/genetics*
  8. Kanniappan P, Ahmed SA, Rajasekaram G, Marimuthu C, Ch'ng ES, Lee LP, et al.
    J Cell Mol Med, 2017 10;21(10):2276-2283.
    PMID: 28756649 DOI: 10.1111/jcmm.13148
    Technological advances in RNA biology greatly improved transcriptome profiling during the last two decades. Besides the discovery of many small RNAs (sRNA) that are involved in the physiological and pathophysiological regulation of various cellular circuits, it becomes evident that the corresponding RNA genes might also serve as potential biomarkers to monitor the progression of disease and treatment. sRNA gene candidate npcTB_6715 was previously identified via experimental RNomic (unpublished data), and we report its application as potential biomarker for the detection of Mycobacterium tuberculosis (MTB) in patient samples. For proof of principle, we developed a multiplex PCR assay and report its validation with 500 clinical cultures, positive for Mycobacteria. The analysis revealed 98.9% sensitivity, 96.1% specificity, positive and negative predictive values of 98.6% and 96.8%, respectively. These results underscore the diagnostic value of the sRNA gene as diagnostic marker for the specific detection of MTB in clinical samples. Its successful application and the general ease of PCR-based detection compared to standard bacterial culture techniques might be the first step towards 'point-of-care' diagnostics of Mycobacteria. To the best of our knowledge, this is the first time for the design of diagnostic applications based on sRNA genes, in Mycobacteria.
    Matched MeSH terms: RNA/genetics*
  9. Jiang L, Hindmarch CC, Rogers M, Campbell C, Waterfall C, Coghill J, et al.
    Sci Rep, 2016 10 24;6:35671.
    PMID: 27774996 DOI: 10.1038/srep35671
    Glucocorticoids are steroids that reduce inflammation and are used as immunosuppressive drugs for many diseases. They are also the mainstay for the treatment of minimal change nephropathy (MCN), which is characterised by an absence of inflammation. Their mechanisms of action remain elusive. Evidence suggests that immunomodulatory drugs can directly act on glomerular epithelial cells or 'podocytes', the cell type which is the main target of injury in MCN. To understand the nature of glucocorticoid effects on non-immune cell functions, we generated RNA sequencing data from human podocyte cell lines and identified the genes that are significantly regulated in dexamethasone-treated podocytes compared to vehicle-treated cells. The upregulated genes are of functional relevance to cytoskeleton-related processes, whereas the downregulated genes mostly encode pro-inflammatory cytokines and growth factors. We observed a tendency for dexamethasone-upregulated genes to be downregulated in MCN patients. Integrative analysis revealed gene networks composed of critical signaling pathways that are likely targeted by dexamethasone in podocytes.
    Matched MeSH terms: RNA/genetics*
  10. Jarolim P, Palek J, Amato D, Hassan K, Sapak P, Nurse GT, et al.
    Proc Natl Acad Sci U S A, 1991 Dec 15;88(24):11022-6.
    PMID: 1722314
    Southeast Asian ovalocytosis (SAO) is a hereditary condition that is widespread in parts of Southeast Asia. The ovalocytic erythrocytes are rigid and resistant to invasion by various malarial parasites. We have previously found that the underlying defect in SAO involves band 3 protein, the major transmembrane protein, which has abnormal structure and function. We now report two linked mutations in the erythrocyte band 3 gene in SAO: (i) a deletion of codons 400-408 and (ii) a substitution, A----G, in the first base of codon 56 leading to substitution of Lys-56 by Glu-56. The first defect leads to a deletion of nine amino acids in the boundary of cytoplasmic and membrane domains of band 3. This defect has been detected in all 30 ovalocytic subjects from Malaysia, the Philippines, and two unrelated coastal regions of Papua New Guinea, whereas it was absent in all 30 controls from Southeast Asia and 20 subjects of different ethnic origin from the United States. The Lys-56----Glu substitution has likewise been found in all SAO subjects. However, it has also been detected in 5 of the 50 control subjects, suggesting that it represents a linked polymorphism. We conclude that the deletion of codons 400-408 in the band 3 gene constitutes the underlying molecular defect in SAO.
    Matched MeSH terms: RNA/genetics
  11. Shamsul BS, Chowdhury SR, Hamdan MY, Ruszymah BHI
    Indian J Med Res, 2019 05;149(5):641-649.
    PMID: 31417032 DOI: 10.4103/ijmr.IJMR_45_17
    Background & objectives: Seeding density is one of the major parameters affecting the quality of tissue-engineered cartilage. The objective of this study was to evaluate different seeding densities of osteoarthritis chondrocytes (OACs) to obtain the highest quality cartilage.

    Methods: The OACs were expanded from passage 0 (P0) to P3, and cells in each passage were analyzed for gross morphology, growth rate, RNA expression and immunochemistry (IHC). The harvested OACs were assigned into two groups: low (1×10[7] cells/ml) and high (3×10[7] cells/ml) cell density. Three-dimensional (3D) constructs for each group were created using polymerised fibrin and cultured for 7, 14 and 21 days in vitro using chondrocyte growth medium. OAC constructs were analyzed with gross assessments and microscopic evaluation using standard histology, IHC and immunofluorescence staining, in addition to gene expression and biochemical analyses to evaluate tissue development.

    Results: Constructs with a high seeding density of 3×10[7] cells/ml were associated with better quality cartilage-like tissue than those seeded with 1×10[7] cells/ml based on overall tissue formation, cell association and extracellular matrix distribution. The chondrogenic properties of the constructs were further confirmed by the expression of genes encoding aggrecan core protein and collagen type II.

    Interpretation & conclusions: Our results confirmed that cell density was a significant factor affecting cell behaviour and aggregate production, and this was important for establishing good quality cartilage.

    Matched MeSH terms: RNA/genetics
  12. Kurtzman CP
    Int J Syst Evol Microbiol, 2007 May;57(Pt 5):1154-1162.
    PMID: 17473275 DOI: 10.1099/ijs.0.64847-0
    The genus Blastobotrys, which now includes species previously assigned to the synonymous genera Arxula and Sympodiomyces, represents the anamorph of the ascosporogenous genus Trichomonascus. Six novel species are proposed for assignment to Blastobotrys. They were detected from their unique nucleotide sequences in large-subunit rDNA, ITS1-5.8S-ITS2 rDNA, mitochondrial small-subunit rDNA and the cytochrome oxidase II gene. The proposed novel species are Blastobotrys americana sp. nov. (type strain NRRL Y-6844(T)=CBS 10337(T); substrate unknown; Kansas, USA), Blastobotrys illinoisensis sp. nov. (type strain NRRL YB-1343(T)=CBS 10339(T); from forest debris; Illinois, USA), Blastobotrys malaysiensis sp. nov. (type strain NRRL Y-6417(T)=CBS 10336(T); from soil; Malaysia), Blastobotrys muscicola sp. nov. (type strain NRRL Y-7993(T)=CBS 10338(T); from moss; Louisiana, USA), Blastobotrys peoriensis sp. nov. (type strain NRRL YB-2290(T)=CBS 10340(T); from a fungus; Peoria, IL, USA) and Blastobotrys raffinosifermentans sp. nov. (type strain NRRL Y-27150(T)=CBS 6800(T); substrate unknown).
    Matched MeSH terms: RNA/genetics
  13. Junaid QO, Khaw LT, Mahmud R, Ong KC, Lau YL, Borade PU, et al.
    Parasite, 2017;24:38.
    PMID: 29034874 DOI: 10.1051/parasite/2017040
    BACKGROUND: As the quest to eradicate malaria continues, there remains a need to gain further understanding of the disease, particularly with regard to pathogenesis. This is facilitated, apart from in vitro and clinical studies, mainly via in vivo mouse model studies. However, there are few studies that have used gerbils (Meriones unguiculatus) as animal models. Thus, this study is aimed at characterizing the effects of Plasmodium berghei ANKA (PbA) infection in gerbils, as well as the underlying pathogenesis.

    METHODS: Gerbils, 5-7 weeks old were infected by PbA via intraperitoneal injection of 1 × 106 (0.2 mL) infected red blood cells. Parasitemia, weight gain/loss, hemoglobin concentration, red blood cell count and body temperature changes in both control and infected groups were monitored over a duration of 13 days. RNA was extracted from the brain, spleen and whole blood to assess the immune response to PbA infection. Organs including the brain, spleen, heart, liver, kidneys and lungs were removed aseptically for histopathology.

    RESULTS: Gerbils were susceptible to PbA infection, showing significant decreases in the hemoglobin concentration, RBC counts, body weights and body temperature, over the course of the infection. There were no neurological signs observed. Both pro-inflammatory (IFNγ and TNF) and anti-inflammatory (IL-10) cytokines were significantly elevated. Splenomegaly and hepatomegaly were also observed. PbA parasitized RBCs were observed in the organs, using routine light microscopy and in situ hybridization.

    CONCLUSION: Gerbils may serve as a good model for severe malaria to further understand its pathogenesis.

    Matched MeSH terms: RNA/genetics
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