Search tips
Search criteria

Results 1-7 (7)

Clipboard (0)

Select a Filter Below

Year of Publication
1.  Characterizing the Impact of Smoking and Lung Cancer on the Airway Transcriptome Using RNA-Seq 
Cigarette smoke creates a molecular field of injury in epithelial cells that line the respiratory tract. We hypothesized that transcriptome sequencing (RNA-Seq) will enhance our understanding of the field of molecular injury in response to tobacco smoke exposure and lung cancer pathogenesis by identifying gene expression differences not interrogated or accurately measured by microarrays. We sequenced the high-molecular-weight fraction of total RNA (>200 nt) from pooled bronchial airway epithelial cell brushings (n = 3 patients per pool) obtained during bronchoscopy from healthy never smoker (NS) and current smoker (S) volunteers and smokers with (C) and without (NC) lung cancer undergoing lung nodule resection surgery. RNA-Seq libraries were prepared using 2 distinct approaches, one capable of capturing non-polyadenylated RNA (the prototype NuGEN Ovation RNA-Seq protocol) and the other designed to measure only polyadenylated RNA (the standard Illumina mRNA-Seq protocol) followed by sequencing generating approximately 29 million 36 nt reads per pool and approximately 22 million 75 nt paired-end reads per pool, respectively. The NuGEN protocol captured additional transcripts not detected by the Illumina protocol at the expense of reduced coverage of polyadenylated transcripts, while longer read lengths and a paired-end sequencing strategy significantly improved the number of reads that could be aligned to the genome. The aligned reads derived from the two complementary protocols were used to define the compendium of genes expressed in the airway epithelium (n = 20,573 genes). Pathways related to the metabolism of xenobiotics by cytochrome P450, retinol metabolism, and oxidoreductase activity were enriched among genes differentially expressed in smokers, whereas chemokine signaling pathways, cytokine–cytokine receptor interactions, and cell adhesion molecules were enriched among genes differentially expressed in smokers with lung cancer. There was a significant correlation between the RNA-Seq gene expression data and Affymetrix microarray data generated from the same samples (P < 0.001); however, the RNA-Seq data detected additional smoking- and cancer-related transcripts whose expression was were either not interrogated by or was not found to be significantly altered when using microarrays, including smoking-related changes in the inflammatory genes S100A8 and S100A9 and cancer-related changes in MUC5AC and secretoglobin (SCGB3A1). Quantitative real-time PCR confirmed differential expression of select genes and non-coding RNAs within individual samples. These results demonstrate that transcriptome sequencing has the potential to provide new insights into the biology of the airway field of injury associated with smoking and lung cancer. The measurement of both coding and non-coding transcripts by RNA-Seq has the potential to help elucidate mechanisms of response to tobacco smoke and to identify additional biomarkers of lung cancer risk and novel targets for chemoprevention.
PMCID: PMC3694393  PMID: 21636547
2.  Treatment of fungal myositis with intra-lesional and intravenous itraconazole: a case report 
Fungal myositis is very uncommon, even in patients who are immunocompromised. Because of its rarity and a lack of clinical experience, no consensus has been reached about the best means of treating fungal myositis. To the best of our knowledge this is the first description of the treatment of fungal myositis with simultaneous intravenous and intra-lesional itraconazole.
Case presentation
A 35-year-old Chinese woman with acute myelomonocytic leukemia developed Candida krusei fungemia and fungal myositis in the right biceps brachii after chemotherapy. A course of intravenous itraconazole and subsequently intravenous voriconazole was initiated and her blood cultures became sterile; however, our patient remained febrile and the myositis did not resolve. Intravenous itraconazole was restarted simultaneously with low-dose intra-lesional itraconazole. The pyrexia settled after 48 hours and within 10 days the lesion could be seen to be resolving. After the course of intravenous and intra-lesional anti-fungals was complete, oral itraconazole was administered as maintenance therapy.
To the best of our knowledge this is the first case in which fungal myositis was successfully treated with intravenous and intra-lesional itraconazole in a patient with acute myelomonocytic leukemia. The efficacy and safety of locally-administered itraconazole to treat intractable soft tissue infections requires further evaluation.
PMCID: PMC3668258  PMID: 23683326
Candida krusei; Fungal myositis; Intra-lesional itraconazole
3.  Characterization of the Amicetin Biosynthesis Gene Cluster from Streptomyces vinaceusdrappus NRRL 2363 Implicates Two Alternative Strategies for Amide Bond Formation 
Amicetin, an antibacterial and antiviral agent, belongs to a group of disaccharide nucleoside antibiotics featuring an α-(1→4)-glycoside bond in the disaccharide moiety. In this study, the amicetin biosynthesis gene cluster was cloned from Streptomyces vinaceusdrappus NRRL 2363 and localized on a 37-kb contiguous DNA region. Heterologous expression of the amicetin biosynthesis gene cluster in Streptomyces lividans TK64 resulted in the production of amicetin and its analogues, thereby confirming the identity of the ami gene cluster. In silico sequence analysis revealed that 21 genes were putatively involved in amicetin biosynthesis, including 3 for regulation and transportation, 10 for disaccharide biosynthesis, and 8 for the formation of the amicetin skeleton by the linkage of cytosine, p-aminobenzoic acid (PABA), and the terminal (+)-α-methylserine moieties. The inactivation of the benzoate coenzyme A (benzoate-CoA) ligase gene amiL and the N-acetyltransferase gene amiF led to two mutants that accumulated the same two compounds, cytosamine and 4-acetamido-3-hydroxybenzoic acid. These data indicated that AmiF functioned as an amide synthethase to link cytosine and PABA. The inactivation of amiR, encoding an acyl-CoA-acyl carrier protein transacylase, resulted in the production of plicacetin and norplicacetin, indicating AmiR to be responsible for attachment of the terminal methylserine moiety to form another amide bond. These findings implicated two alternative strategies for amide bond formation in amicetin biosynthesis.
PMCID: PMC3302616  PMID: 22267658
6.  A gene expression signature of emphysema-related lung destruction and its reversal by the tripeptide GHK 
Genome Medicine  2012;4(8):67.
Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease consisting of emphysema, small airway obstruction, and/or chronic bronchitis that results in significant loss of lung function over time.
In order to gain insights into the molecular pathways underlying progression of emphysema and explore computational strategies for identifying COPD therapeutics, we profiled gene expression in lung tissue samples obtained from regions within the same lung with varying amounts of emphysematous destruction from smokers with COPD (8 regions × 8 lungs = 64 samples). Regional emphysema severity was quantified in each tissue sample using the mean linear intercept (Lm) between alveolar walls from micro-CT scans.
We identified 127 genes whose expression levels were significantly associated with regional emphysema severity while controlling for gene expression differences between individuals. Genes increasing in expression with increasing emphysematous destruction included those involved in inflammation, such as the B-cell receptor signaling pathway, while genes decreasing in expression were enriched in tissue repair processes, including the transforming growth factor beta (TGFβ) pathway, actin organization, and integrin signaling. We found concordant differential expression of these emphysema severity-associated genes in four cross-sectional studies of COPD. Using the Connectivity Map, we identified GHK as a compound that can reverse the gene-expression signature associated with emphysematous destruction and induce expression patterns consistent with TGFβ pathway activation. Treatment of human fibroblasts with GHK recapitulated TGFβ-induced gene-expression patterns, led to the organization of the actin cytoskeleton, and elevated the expression of integrin β1. Furthermore, addition of GHK or TGFβ restored collagen I contraction and remodeling by fibroblasts derived from COPD lungs compared to fibroblasts from former smokers without COPD.
These results demonstrate that gene-expression changes associated with regional emphysema severity within an individual's lung can provide insights into emphysema pathogenesis and identify novel therapeutic opportunities for this deadly disease. They also suggest the need for additional studies to examine the mechanisms by which TGFβ and GHK each reverse the gene-expression signature of emphysematous destruction and the effects of this reversal on disease progression.
PMCID: PMC4064320  PMID: 22937864
7.  The study of human PDGF-B gene transferred to cat corneal endothelial cells 
To demonstrate that human platelet-derived growth factor-B (PDGF-B) cDNA could be expressed in primary cultured cat corneal endothelia cells by using gene transfer techniques; to explore a useful tool for the further studies of the molecular mechanisms of corneal endothelium failure and provide a potential effective genetic therapy for the blind patients.
Human PDGF-B cDNA was isolated from human placent by RT-PCR and inserted into pcDNA4 vector to construct recombinant eukaryotic expression plasmid pcDNA4-PDGF-B. The full length was confirmed by the DNA sequencing analysis. By tearing endothelium technique we obtained pure single layer of cat corneal endothelial cells. The pcDNA4-PDGF-B eukaryotic expression vector was transferred into cat corneal endothelial cells by Effectene™ lipofectine. The transfection efficiency of Effectene™ lipofectine in pcDNA4-B was detected with pcDNA4-GFP. 5 days later, RT-PCR was used to check the PDGF-B expression. Cell viability was tested by modified tertrozalium salt (MTT) method. Cell morphology was observed under inverted phase contrast microscope.
The human PDGF-B cDNA was isolated successfully from healthy parturien placent tissue and the sequence was confirmed by computer automatic sequence and PCR analysis. Pure single layer cat corneal endothelial cells were successfully cultured by tearing endothelium technique. Effectene™ lipofectine transfection technique could be effectively used to transfer pcDNA4-PDGF-B into cat corneal endothelial cells in vitro, the transfection efficiency was 30%. RT-PCR result showed that human PDGF-B gene was highly expressed in transfected cat corneal endothelial cells. The expressed PDGF-BB protein promoted the viability of cat corneal endothelial cells.
Human platelet-derived growth factor-B (PDGF-B) cDNA could be highly expressed in cultured cat corneal endothelial cells by gene transfection techniques. Expressed PDGF-BB protein significantly promoted the viability of cat corneal endothelial cells, thus provided a potential effective method for corneal endothelium blindness genetic therapy.
PMCID: PMC3340845  PMID: 22553748
platelet-derived growth factor; corneal endothelial cell; viability; gene transfection.

Results 1-7 (7)