Search tips
Search criteria

Results 1-14 (14)

Clipboard (0)

Select a Filter Below

more »
Year of Publication
1.  Difluorocarbene-derived Trifluoromethylthiolation and [18F]Trifluoromethylthiolation of Aliphatic Electrophiles 
The first trifluoromethylthiolation and [18F]trifluoromethylthiolation of alkyl electrophiles with in situ generated difluorocarbene in the presence of elemental sulfur and external (radioactive) fluoride ion is described. This transition metal-free approach is high yielding, compatible with variety of functional groups and operated under mild conditions. The conceptual advantage of this exogenous fluoride mediated transformation enables unprecedented syntheses of [18F]CF3S-labeled molecules from most commonly used [18F]fluoride ion. The rapid radiochemical reaction time (≤ 1 min) and highly functional group tolerance allow this method to access a variety of aliphatic [18F]CF3S compounds in high yields.
PMCID: PMC4692268  PMID: 26387796
trifluoromethylthiolation; difluorocarbene; fluorine-18; positron emission tomography; metal free
2.  Defining the Nasal Transcriptome in Granulomatosis with Polyangiitis 
To determine whether disease processes related to granulomatosis with polyangiitis (GPA) are reflected in gene expression profiles of nasal mucosa.
Nasal brushings of the inferior turbinate were obtained from 32 patients with GPA (10 with active nasal disease, 13 with prior nasal disease, 9 with no history of nasal disease) and a composite comparator group with and without inflammatory nasal disease (12 healthy people, 15 with sarcoidosis, 8 with allergic rhinitis). Differential gene expression was assessed between subgroups of GPA and comparators.
339 genes were differentially expressed between the GPA and comparator groups (absolute fold change > 1.5; false discovery rate < 0.05). Top canonical pathways upregulated in nasal brushings from patients with GPA include granulocyte adhesion and diapedesis (p=8.6 E-22), agranulocyte adhesion and diapedesis (p=1.3 E-14), interleukin 10 signaling (3.0 E-11), and TREM1 signaling (9.0 E-11). A set of genes differentially expressed in GPA independent of nasal disease activity status included genes related to epithelial barrier integrity (fibronectin 1, desmosomal proteins) and several matricellular proteins (e.g. osteonectin, osteopontin). Significant overlap of differentially expressed genes was observed between active and prior nasal disease GPA subgroups. Peripheral blood neutrophil and mononuclear gene expression levels associated with GPA were similarly altered in the nasal gene expression profiles of patients with active or prior nasal disease.
Profiling the nasal transcriptome in GPA reveals gene expression signatures related to innate immunity, inflammatory cell chemotaxis, extracellular matrix composition, and epithelial barrier integrity. Airway-based expression profiling is feasible and informative in GPA.
PMCID: PMC4519398  PMID: 25939343
vasculitis; granulomatosis with polyangiitis (GPA Wegener’s); gene expression; ANCA-associated vasculitis; nasal mucosa
3.  Nucleophilic arylation with tetraarylphosphonium salts 
Nature Communications  2016;7:10337.
Organic phosphonium salts have served as important intermediates in synthetic chemistry. But the use of a substituent on the positive phosphorus as a nucleophile to construct C–C bond remains a significant challenge. Here we report an efficient transition-metal-free protocol for the direct nucleophilic arylation of carbonyls and imines with tetraarylphosphonium salts in the presence of caesium carbonate. The aryl nucleophile generated from phosphonium salt shows low basicity and good nucleophilicity, as evidenced by the successful conversion of enolizable aldehydes and ketones. The reaction is not particularly sensitive to water, shows wide substrate scope, and is compatible with a variety of functional groups including cyano and ester groups. Compared with the arylmetallic reagents that are usually moisture sensitive, the phosphonium salts are shelf-stable and can be easily handled.
Carbon based nucleophiles often are synthetically limited by the high basicity/reactivity of the starting materials. Here, the authors show that tetraarylphosphonium salts can be induced to act as C-aryl nucleophiles for the addition to carbonyls and imines.
PMCID: PMC4740112  PMID: 26822205
4.  Down-regulated Na+/K+-ATPase activity in ischemic penumbra after focal cerebral ischemia/reperfusion in rats 
This study was aimed to examine whether the Na+/K+ adenosine triphosphatase (Na+/K+-ATPase) activity in ischemic penumbra is associated with the pathogenesis of ischemia/reperfusion-induced brain injury. An experimental model of cerebral ischemia/reperfusion was made by transient middle cerebral artery occlusion (tMCAO) in rats and the changes of Na+/K+-ATPase activity in the ischemic penumbra was examined by Enzyme Assay Kit. Extensive infarction was observed in the frontal and parietal cortical and subcortical areas at 6 h, 24 h, 48 h, 3 d and 7 d after tMCAO. Enzyme Assay analyses revealed the activity of Na+/K+-ATPase was decreased in the ischemic penumbra of model rats after focal cerebral ischemia/reperfusion compared with sham-operated rats, and reduced to its minimum at 48 h, while the infarct volume was enlarged gradually. In addition, accompanied by increased brain water content, apoptosis-related bcl-2 and Bax proteins, apoptotic index and neurologic deficits Longa scores, but fluctuated the ratio of bcl-2/Bax. Correlation analysis showed that the infarct volume, apoptotic index, neurologic deficits Longa scores and brain water content were negatively related with Na+/K+-ATPase activity, while the ratio of bcl-2/Bax was positively related with Na+/K+-ATPase activity. Our results suggest that down-regulated Na+/K+-ATPase activity in ischemic penumbra might be involved in the pathogenesis of cerebral ischemia/reperfusion injury presumably through the imbalance ratio of bcl-2/Bax and neuronal apoptosis, and identify novel target for neuroprotective therapeutic intervention in cerebral ischemic disease.
PMCID: PMC4680405  PMID: 26722460
Cerebral ischemia/reperfusion; Na+/K+-ATPase; penumbra; apoptosis; bcl-2; bax
5.  Assessment of immune cells and function of the residual spleen after subtotal splenectomy due to splenomegaly in cirrhotic patients 
BMC Immunology  2014;15:42.
The spleen is thought to be central in regulating the immune system, a metabolic asset involved in endocrine function. Overwhelming postsplenectomy infection leads to a mortality rate of up to 50%. However, there is still controversy on performing subtotal splenectomy as treatment of splenomegaly due to portal hypertension in cirrhotic patients. In the present study, immunocytes and the indexes of splenic size, hemodynamics, hematology and immunology in the residual spleen were analyzed to support subtotal splenectomy due to splenomegaly.
In residual spleen, T lymphocytes mainly were focal aggregation in the periarterial lymphatic sheath. While B lymphocytes densely distributed in splenic corpuscle. In red pulp, macrophages were equally distributed in the xsplenic cord and adhered to the wall of splenic sinus with high density. The number of unit area T and B lymphocytes of splenic corpuscle and marginal zone as well as macrophages of red pulp were obviously increased in the residual spleen, while the number of macrophages didn’t be changed among the three groups in white pulp. While there were some beneficial changes (i.e., Counts of platelet and leucocyte as well as serum proportion of CD3+ T cells, CD4+ T cells, CD8+ T cells were increased markedly; serum levels of M-CSF and GM-CSF were decreased significantly; The proportion of granulocyte, erythrocyte, megakaryocyte in bone marrow were changed obviously; But serum IgA, IgM, IgG, Tuftsin level, there was no significant difference; splenic artery flow volume, portal venous diameter and portal venous flow volume, a significant difference was observed in residual spleen) in the clinical indices.
After subtotal splenectomy with splenomegaly due to portal hypertension in cirrhotic patients, the number of unit area T and B lymphocytes, and MØ in red pulp of residual spleen increased significantly. However, whether increase of T, B lymphocytes and MØs in residual splenic tissue can enhance the immune function of the spleen, still need further research to confirm.
PMCID: PMC4193139  PMID: 25293512
Residual spleen; Splenomegaly; Portal hypertension; T, B lymphocytes; Macrophage; Immune
6.  A Dynamic Bronchial Airway Gene Expression Signature of Chronic Obstructive Pulmonary Disease and Lung Function Impairment 
Rationale: Molecular phenotyping of chronic obstructive pulmonary disease (COPD) has been impeded in part by the difficulty in obtaining lung tissue samples from individuals with impaired lung function.
Objectives: We sought to determine whether COPD-associated processes are reflected in gene expression profiles of bronchial airway epithelial cells obtained by bronchoscopy.
Methods: Gene expression profiling of bronchial brushings obtained from 238 current and former smokers with and without COPD was performed using Affymetrix Human Gene 1.0 ST Arrays.
Measurements and Main Results: We identified 98 genes whose expression levels were associated with COPD status, FEV1% predicted, and FEV1/FVC. In silico analysis identified activating transcription factor 4 (ATF4) as a potential transcriptional regulator of genes with COPD-associated airway expression, and ATF4 overexpression in airway epithelial cells in vitro recapitulates COPD-associated gene expression changes. Genes with COPD-associated expression in the bronchial airway epithelium had similarly altered expression profiles in prior studies performed on small-airway epithelium and lung parenchyma, suggesting that transcriptomic alterations in the bronchial airway epithelium reflect molecular events found at more distal sites of disease activity. Many of the airway COPD-associated gene expression changes revert toward baseline after therapy with the inhaled corticosteroid fluticasone in independent cohorts.
Conclusions: Our findings demonstrate a molecular field of injury throughout the bronchial airway of active and former smokers with COPD that may be driven in part by ATF4 and is modifiable with therapy. Bronchial airway epithelium may ultimately serve as a relatively accessible tissue in which to measure biomarkers of disease activity for guiding clinical management of COPD.
PMCID: PMC3707363  PMID: 23471465
chronic obstructive pulmonary disease; gene expression profiling; biologic markers
7.  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
8.  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
9.  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
12.  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
13.  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.
14.  Ibrolipim increases ABCA1/G1 expression by the LXRα signaling pathway in THP-1 macrophage-derived foam cells 
Acta Pharmacologica Sinica  2010;31(10):1343-1349.
To determine the effects and potential mechanisms of ibrolipim on ATP-binding membrane cassette transporter A-1 (ABCA1) and ATP-binding membrane cassette transporter G-1 (ABCG1) expression from human macrophage foam cells, which may play a critical role in atherogenesis.
Human THP-1 cells pre-incubated with ox-LDL served as foam cell models. Specific mRNA was quantified using real-time RT-PCR and protein expression using Western blotting. Cellular cholesterol handling was studied using cholesterol efflux experiments and high performance liquid chromatography assays.
Ibrolipim 5 and 50 μmol/L significantly increased cholesterol efflux from THP-1 macrophage-derived foam cells to apoA-I or HDL. Moreover, it upregulated the expression of ABCA1 and ABCG1. In addition, LXRα was also upregulated by the ibrolipim treatment. In addition, LXRα small interfering RNA completely abolished the promotion effect that was induced by ibrolipim.
Ibrolipim increased ABCA1 and ABCG1 expression and promoted cholesterol efflux, which was mediated by the LXRα signaling pathway.
PMCID: PMC4012897  PMID: 20871621
ATP-binding membrane cassette transporter A-1; ATP-binding membrane cassette transporter G-1; ibrolipim; liver X receptor α; atherosclerosis; RNA interference; high density lipoprotein; apolipoprotein; cholesterol

Results 1-14 (14)