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1.  High Sensitive Sensor Fabricated by Reduced Graphene Oxide/Polyvinyl Butyral Nanofibers for Detecting Cu (II) in Water 
Graphene oxide (GO)/polyvinyl butyral (PVB) nanofibers were prepared by a simple electrospinning technique with PVB as matrix and GO as a functional nanomaterial. GO/PVB nanofibers on glassy carbon electrode (GCE) were reduced through electrochemical method to form reduced graphene oxide (RGO)/PVB nanofibers. The morphology and structure of GO/PVB nanofiber were studied by scanning election microscopy (SEM), transmission electron microscopy (TEM), and Fourier transform infrared (FTIR). RGO/PVB modified GCE was used for fabricating an electrochemical sensor for detecting Cu (II) in water. The analysis results showed that RGO/PVB modified GCE had good analytical results with the linear range of 0.06–2.2 μM, detection limit of 4.10 nM (S/N = 3), and the sensitivity of 103.51 μA·μM−1·cm−2.
PMCID: PMC4324952
2.  Increased activity of Rho kinase contributes to hemoglobin-induced early disruption of the blood-brain barrier in vivo after the occurrence of intracerebral hemorrhage 
This study is to examine whether the activation of Rho kinase (ROCK) accounts for hemoglobin (Hb)-induced disruption of blood-brain barrier (BBB) after the occurrence of intracerebral hemorrhage. A model of intracerebral injection of Hb was established in rats. Changes in the levels of mRNA of RhoA, ROCK2 and matrix metalloproteinase-9 (MMP-9) were measured using quantitative real-time polymerase chain reaction. Protein expression of RhoA, ROCK2, claudin-5 and MMP-9, as well as ROCK activity, were determined using Western blotting. Immunohistochemical assay was performed to visualize the expression of RhoA, ROCK2, claudin-5 and MMP-9 in endothelial cells. Hb injection produced a significant increase in BBB permeability and water content in the brain. Significant reduction of claudin-5 expression was detected by Western blotting and immunofluorescence in Hb group. The levels of RhoA and ROCK2 were significantly up-regulated from 6 h to 12 h after Hb injection and were concomitant with the increase in ROCK activity. Immunofluorescence double staining showed enhanced p-myosin light chain immunoreactivity but diminished claudin-5 staining in endothelial cells. Significant up-regulation of MMP-9 expression was detected after Hb injection, and statistical analyses further confirmed a positive correlation of MMP-9 expression with ROCK activity. The results showed that ROCK was activated in endothelial cells by Hb. This may account for the early disruption of the BBB via up-regulation of p-myosin light chain expression and aggravation of injuries to TJ proteins. The activation of ROCK may also increase MMP-9 expression, thereby leading to further BBB disruption.
PMCID: PMC4270524  PMID: 25550824
Blood-brain barrier; hemoglobin; Rho kinase; tight junction; intracerebral hemorrhage; matrix metalloproteinase
3.  Identity and Specificity of Rhizoctonia-Like Fungi from Different Populations of Liparis japonica (Orchidaceae) in Northeast China 
PLoS ONE  2014;9(8):e105573.
Mycorrhizal association is known to be important to orchid species, and a complete understanding of the fungi that form mycorrhizas is required for orchid ecology and conservation. Liparis japonica (Orchidaceae) is a widespread terrestrial photosynthetic orchid in Northeast China. Previously, we found the genetic diversity of this species has been reduced recent years due to habitat destruction and fragmentation, but little was known about the relationship between this orchid species and the mycorrhizal fungi. The Rhizoctonia-like fungi are the commonly accepted mycorrhizal fungi associated with orchids. In this study, the distribution, diversity and specificity of culturable Rhizoctonia-like fungi associated with L. japonica species were investigated from seven populations in Northeast China. Among the 201 endophytic fungal isolates obtained, 86 Rhizoctonia-like fungi were identified based on morphological characters and molecular methods, and the ITS sequences and phylogenetic analysis revealed that all these Rhizoctonia-like fungi fell in the same main clade and were closely related to those of Tulasnella calospora species group. These findings indicated the high mycorrhizal specificity existed in L. japonica species regardless of habitats at least in Northeast China. Our results also supported the wide distribution of this fungal partner, and implied that the decline of L. japonica in Northeast China did not result from high mycorrhizal specificity. Using culture-dependent technology, these mycorrhizal fungal isolates might be important sources for the further utilizing in orchids conservation.
PMCID: PMC4139347  PMID: 25140872
4.  Association between IL-21 gene rs907715 polymorphisms and Graves’ disease in a Southern Chinese population 
Interleukin-21 (IL-21) is a pleiotropic cytokine linking innate and adaptive immune responses, which has been reported to play a key role in multiple autoimmune diseases. The aim of the present case-control study was to investigate the genetic association between single nucleotide polymorphisms (SNPs) of rs907715 within the IL-21 gene and Graves’ disease (GD) in a Southern Chinese population. A total of 211 patients with GD and 212 control subjects were recruited for the study. IL-21 gene rs907715 polymorphisms were detected by direct DNA sequencing. The results indicated that the frequencies of the GG genotype and the G allele in GD patients were significantly increased when compared with the frequencies in the controls (P=6.7×10−3 and P=2.0×10−5, respectively). In addition, the frequency of the AA genotype was much lower in the patient group when compared with the control group (16.6 vs. 34.0%; P=4.0×10−5). Furthermore, the G allele of rs907715 was associated with relapse in GD patients. These observations indicated that polymorphisms of IL-21/rs907715 may affect the susceptibility to GD in a Southern Chinese population. The G allele was significantly associated with an increased risk of GD development, whereas the A allele may lower the susceptibility to GD.
PMCID: PMC4061203  PMID: 24944624
interleukin-21; Graves’ disease; gene polymorphisms
9.  Effects of Aging on Kidney Graft Function, Oxidative Stress and Gene Expression after Kidney Transplantation 
PLoS ONE  2013;8(6):e65613.
Conflicting results have been reported regarding the effects of donor age, recipient age and donor-recipient age difference on short- and long-term outcomes after kidney transplantation. The aim of this study was to evaluate the effects of recipient age on graft function, oxidative stress, and gene expression after renal transplantation. Fifty male Fischer 344 rats [25 young (Y, 4 months), 25 senior (S, 16 months)] were randomized to 6 groups: 2 sham groups (Y and S, n = 5 in each group) and 4 renal transplant groups[young-to-young (Y-Y), young-to-senior (Y-S), senior-to-young (S-Y), senior-to-senior (S-S), (n = 10 in each group)]. The left kidneys were transplanted from donor to recipient. After 12 weeks, systematic blood pressure, graft weight, graft function, histology and oxidative stress were measured. Microarray analysis and quantitative real-time PCR confirmation were performed to study gene expression in the grafts. There were no differences in renal graft function between young and senior kidney cross-transplantation. Transplanted kidneys showed no significant differences in glomerulosclerosis index compared to non-transplanted kidneys but had significantly different tubulointerstitium scores compared to age-matched controls. Senior rats had lower SOD activity and higher MDA content than young rats. SOD activity was significantly lower and MDA content significantly higher in the Y-S group than in the Y-Y group. There were 548 transcript differences between senior and young kidneys with 36 upregulated and 512 downregulated transcripts. There were 492 transcript differences between Y-S and Y-Y groups with 127 upregulated and 365 downregulated transcripts. There were 1244 transcript differences between the S-Y and S-S groups with 680 upregulated and 574 downregulated transcripts. Oxidative stress and gene expression profile was significantly different in the Y-S compared to the S-Y group. The identified differences were mainly in the MAPK and insulin signal pathways, making these potential targets for therapeutic intervention.
PMCID: PMC3688821  PMID: 23824036
10.  Identification and functional analysis of gene cluster involvement in biosynthesis of the cyclic lipopeptide antibiotic pelgipeptin produced by Paenibacillus elgii 
BMC Microbiology  2012;12:197.
Pelgipeptin, a potent antibacterial and antifungal agent, is a non-ribosomally synthesised lipopeptide antibiotic. This compound consists of a β-hydroxy fatty acid and nine amino acids. To date, there is no information about its biosynthetic pathway.
A potential pelgipeptin synthetase gene cluster (plp) was identified from Paenibacillus elgii B69 through genome analysis. The gene cluster spans 40.8 kb with eight open reading frames. Among the genes in this cluster, three large genes, plpD, plpE, and plpF, were shown to encode non-ribosomal peptide synthetases (NRPSs), with one, seven, and one module(s), respectively. Bioinformatic analysis of the substrate specificity of all nine adenylation domains indicated that the sequence of the NRPS modules is well collinear with the order of amino acids in pelgipeptin. Additional biochemical analysis of four recombinant adenylation domains (PlpD A1, PlpE A1, PlpE A3, and PlpF A1) provided further evidence that the plp gene cluster involved in pelgipeptin biosynthesis.
In this study, a gene cluster (plp) responsible for the biosynthesis of pelgipeptin was identified from the genome sequence of Paenibacillus elgii B69. The identification of the plp gene cluster provides an opportunity to develop novel lipopeptide antibiotics by genetic engineering.
PMCID: PMC3479019  PMID: 22958453
Non-ribosomal peptide; Biosynthesis; Gene cluster; Antimicrobial agent
11.  Draft Genome Sequence of Paenibacillus elgiiB69, a Strain with Broad Antimicrobial Activity ▿  
Journal of Bacteriology  2011;193(17):4537.
Here, we report the draft genome sequence of Paenibacillus elgiiB69, which was isolated from soil and has broad-spectrum antimicrobial activity. As far as we know, the P. elgiigenome is the largest of the Paenibacillusgenus for which genome sequences are available. Multiple sets of genes related to antibiotic biosynthetic pathways have been found in the genome.
PMCID: PMC3165517  PMID: 21705583
12.  6,6′-Di-tert-butyl-4,4′-dimethyl-2,2′-[1,2-phenyl­enebis(nitrilo­methanylyl­idene)]diphenol 
In the title mol­ecule, C30H36N2O2, the dihedral angles between the central benzene ring and the two benzene rings of the butyl­salicylaldimine groups are 14.3 (2) and 40.6 (2)°. There are two strong intra­molecular O—H⋯N hydrogen bonds which form S(6) rings. The crystal studied was a non-merohedral twin with refined components of 0.270 (4) and 0.730 (4).
PMCID: PMC3254401  PMID: 22259544
13.  Bis­(chloro­acetato-κO)bis(trimethyl­silylmethyl)tin(IV) 
In the title complex, [Sn(C2H2ClO2)2(C4H11Si)2], the SnIV ion is coordinated in a distorted tetra­hedral environment formed by two O atoms from two monodenate chloro­acetato ligands and two C atoms from two trimethyl silyl ligands. Two further weak intra­molecular Sn⋯O contacts [2.744 (2) and 2.655 (2) Å] are formed by the chloro­acetato ligands.
PMCID: PMC3200893  PMID: 22058841
14.  Paenimacrolidin, a novel macrolide antibiotic from Paenibacillus sp. F6‐B70 active against methicillin‐resistant Staphylococcus aureus 
Microbial biotechnology  2011;4(4):491-502.
Paenibacillus sp. F6‐B70 was selected from several dozens of isolates with activity against methicillin‐resistant Staphylococcus aureus using a 16S rDNA‐based screening method. F6‐B70 contained polyketide synthase (PKS) and non‐ribosomal peptide synthetase (NRPS) clusters in its genome revealed by PCR amplification of conserved adenylation and ketosynthase (KS) domains. Phylogenetic data suggested that the strain hosts trans‐AT PKSs and their product may be a branched molecule. An antibiotic was subsequently isolated from the methanol extract of F6‐B70 cells. The molecular formula of the antibiotic was deduced to be C33H50NaO6 ([M + Na]+, m/z 565.3505) by analysis of electrospray ionization mass spectral data. Elucidation of the structure by nuclear magnetic resonance and infrared spectroscopy revealed that the active compound, paenimacrolidin (PAM), was a novel 22‐membered macrolide with side‐chains. The new antibiotic, mainly as a bacteriostatic agent, inhibits a couple of multidrug‐resistant Staphylococcus sp. strains. The antibiotic capacity of PAM was compromised by its instability, which can be overcome significantly with addition of an anti‐oxidant. To our knowledge, this is the first report of the isolation of an active macrolide from paenibacilli, which may be a promising source of novel antibiotics.
PMCID: PMC3815261  PMID: 21375709
15.  The evolutionary rate variation among genes of HOG-signaling pathway in yeast genomes 
Biology Direct  2010;5:46.
Responses to extracellular stress are required for microbes to survive in changing environments. Although the stress response mechanisms have been characterized extensively, the evolution of stress response pathway remains poorly understood. Here, we studied the evolution of High Osmolarity Glycerol (HOG) pathway, one of the important osmotic stress response pathways, across 10 yeast species and underpinned the evolutionary forces acting on the pathway evolution.
Although the HOG pathway is well conserved across the surveyed yeast species, the evolutionary rate of the genes in this pathway varied substantially among or within different lineages. The fast divergence of MSB2 gene indicates that this gene is subjected to positive selection. Moreover, transcription factors in HOG pathway tend to evolve more rapidly, but the genes in conserved MAPK cascade underwent stronger functional selection. Remarkably, the dN/dS values are negatively correlated with pathway position along HOG pathway from Sln1 (Sho1) to Hog1 for transmitting external signal into nuclear. The increased gradient of selective constraints from upstream to downstream genes suggested that the downstream genes are more pleiotropic, being required for a wider range of pathways. In addition, protein length, codon usage, gene expression, and protein interaction appear to be important factors to determine the evolution of genes in HOG pathway.
Taken together, our results suggest that functional constraints play a large role in the evolutionary rate variation in HOG pathway, but the genetic variation was influenced by quite complicated factors, such as pathway position, protein length and so on. These findings provide some insights into how HOG pathway genes evolved rapidly for responding to environmental osmotic stress changes.
This article was reviewed by Han Liang (nominated by Laura Landweber), Georgy Bazykin (nominated by Mikhail Gelfand) and Zhenguo Lin (nominated by John Logsdon).
PMCID: PMC2914728  PMID: 20618989
16.  Expression of tissue inhibitor of matrix metalloproteinases-1 during aging in rat liver 
AIM: To investigate the expression and role of tissue inhibitor of matrix metalloproteinases-1 (TIMP-1) during natural aging in rat liver and to detect the expression of matrix metalloproteinase-2 (MMP-2) and MMP-9.
METHODS: The rats were divided into 3-mo-old group (n = 5), 10-mo-old group (n = 5) and 24-mo-old group (n = 5). Histopathologic changes of liver were observed with HE and Masson stain. The location and protein expressions of TIMP-1 were determined by immunohistochemistry and Western blot; message RNA (mRNA) levels were measured in livers from rats of various ages by semi-quantitative reverse transcriptional polymerase chain reaction (RT-PCR). In addition, the expression of MMP-2 and MMP-9 was assessed by RT-PCR and Western blot.
RESULTS: Histologic examination showed that the aging liver had excessive fatty degeneration and collagen deposition. Immunohistochemical staining showed that TIMP-1 related antigen in livers was located in cytoplasm. The protein expression of TIMP-1 was significantly higher in the oldest animals and the mRNA expression was increased significantly in the 24-mo-old rats (t = 4.61, P = 0.002<0.05, 24-vs 10-mo-old rats; t = 4.31, P = 0.003<0.05, 24- vs 3-mo-old rats). The expression of MMP-2 and MMP-9 had no change during aging; the ratios TIMP-1/MMP-2 and TIMP-1/MMP-9 in aging liver were significantly higher than those in maturation and young livers.
CONCLUSION: TIMP-1 may play an important role in the process of liver aging.
PMCID: PMC4316019  PMID: 15968723
TIMP-1; Aging; Rat liver
17.  Mesenchymal stem cells attenuate ischemic acute kidney injury by inducing regulatory T cells through splenocyte interactions 
Kidney International  2013;84(3):521-531.
The mechanism of mesenchymal stem cell therapy in acute kidney injury remains uncertain. Previous studies indicated that mesenchymal stem cells could attenuate inflammation-related organ injury by induction of regulatory T cells. Whether regulatory T-cell induction is a potential mechanism of mesenchymal stem cell therapy in ischemic acute kidney injury and how these induced regulatory T cells orchestrate local inflammation are unknown. Here we found that mesenchymal stem cells decrease serum creatinine and urea nitrogen levels, improve tubular injury, and downregulate IFN-γ production of T cells in the ischemic kidney. In addition to the lung, mesenchymal stem cells persisted mostly in the spleen. Mesenchymal stem cells increased the percentage of regulatory T cells in the spleen and the ischemic kidney. Antibody-dependent depletion of regulatory T cells blunted the therapeutic effect of mesenchymal stem cells, while coculture of splenocytes with mesenchymal stem cells caused an increase in the percentage of regulatory T cells. Splenectomy abrogated attenuation of ischemic injury, and downregulated IFN-γ production and the induction of regulatory T cells by mesenchymal stem cells. Thus, mesenchymal stem cells ameliorate ischemic acute kidney injury by inducing regulatory T cells through interactions with splenocytes. Accumulated regulatory T cells in ischemic kidney might be involved in the downregulation of IFN-γ production.
PMCID: PMC3778762  PMID: 23615497
ischemic acute kidney injury; mesenchymal stem cells; regulatory T cells; spleen

Results 1-17 (17)