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Ge C.,Chinese Academy of Sciences | Ge C.,Hefei University of Technology | Luo Q.,Guangzhou Institute of Dermatology | Wang D.,Chinese Academy of Sciences | And 6 more authors.
Analytical Chemistry | Year: 2014

G-quadruplex-forming sequence can be formed through a copper(I) ion (Cu+)-catalyzed click chemistry between azide-and alkyne-modified short G-rich sequences in aqueous solution, eliminating immobilization and washing steps of conventional assays. The source for Cu+ was generated from the reduction of Cu2+ with the reductant of sodium ascorbate. In the presence of hemin and K+, the self-assembly of hemin/G-quadruplex structure has the activity of horseradish peroxidase (HRP), which can catalyze its colorless substrate tetrazmethyl benzidine (TMB) into a colored product. Hence, the concentration of Cu2+ can be evaluated visually for qualitative analysis according to the color change of the solution, and the optical density (OD) value of the resulting solution at 450 nm was also recorded using a microplate reader for quantitative analysis. © 2014 American Chemical Society.


Zhao N.,North Dakota State University | Zhao N.,Shanxi Institute of Coal CAS Chemistry | He Y.,Guangzhou Institute of Dermatology | Mao X.,North Dakota State University | And 5 more authors.
Electrochemistry Communications | Year: 2010

This paper presents a novel approach to electrochemically determine enzymatically active PSA using ferrocene-functionalized helix peptide (CHSSLKQK). The principle of electrochemical measurement is based on the specific proteolytic cleavage events of the FC-peptide on the gold electrode surface in the presence of PSA, resulting the change of the current signal of the electrode. The percentage of the decreased current is linear with the concentration of active PSA at the range of 0.5-40 ng mL-1 with a detection limit of 0.2 ng mL-1. The direct transduction of peptide cleavage events into an electrical signal provides a simple, sensitive method for detecting the enzymatic activity of PSA and determining the active PSA concentration.


Li C.-X.,University of South China | Li C.-X.,Dongguan Institute of Dermatology | Han C.-L.,Dongguan Institute of Dermatology | Zeng K.,University of South China | And 2 more authors.
British Journal of Dermatology | Year: 2014

Background A series of cases of symmetrical acral keratoderma have been described recently in China. However, no studies about its demographic information and epidermal barrier function have been documented. Objectives To describe the clinical manifestation, demographic information and clinicopathological features of 71 cases with symmetrical acral keratoderma. Patients and methods Seventy-one cases with symmetrical acral keratoderma were retrospectively reviewed. Their demographic information, clinical manifestations, histopathology and epidermal barrier function were analysed. Results Among these patients, there were 64 males and seven females, ranging in age from 4 to 53 years with an average age at onset of 27 ± 8·9 years. Clinical manifestation was characterized by brown hyperkeratotic patches over the dorsum of the hands, palms and feet, dorsal digits and wrists, elbows, knees and ankles. The lesions became dramatically whitish with mild swelling immediately after soaking in water and resolved spontaneously in winter. In patients, a moderate increase of transepidermal water loss (TEWL) from 16·16 ± 6·15 to 9·9 ± 4·21 g m -2 h-1 (P = 0·0054) and a moderate decrease of skin hydration from 65·9 ± 5·06 to 42·58 ± 10·73 (P < 0·01) in comparison with the control group were observed. Histopathological examination revealed epidermal hyperkeratosis, acanthosis and papillomatous hyperplasia as well as dermal infiltration with a few lymphocytes. Conclusions Symmetrical acral keratoderma is characterized by symmetry, acra, keratinization and marked seasonal changes. The epidermal barrier function of the skin was negatively affected. What's already known about this topic? A series of cases of symmetrical acral keratoderma have been described recently in China. However, no studies of demographic information and epidermal permeability barrier function have been documented. What does this study add? Symmetrical acral keratoderma is characterized by symmetry, acra, keratinization and marked seasonal changes. The epidermal barrier function of the skin was negatively affected. © 2013 British Association of Dermatologists.


He Y.,Guangzhou Institute of Dermatology | He Y.,North Dakota State University | Zhang X.,Guangzhou Institute of Dermatology | Zhang S.,Guangzhou Institute of Dermatology | And 5 more authors.
Biosensors and Bioelectronics | Year: 2012

We describe a hairpin oligonucleotide (HO) with double-target DNA binding sequences in the loop and 11-base in the stem for visual detection of single-base mismatches (SBM) in DNA with highly specificity. The thiol-modified HO was immobilized on gold nanoparticle (Au-NP) surface through a self-assembling process. The strategy of detecting SBM depends on the unique molecular recognition properties of HO to the perfect-matched DNA and SBM to generate different quantities of duplex DNA on the Au-NP surface, which are captured on the test zone of lateral flow test strip via the DNA hybridization reaction between the duplex DNA and preimmobilized DNA probe. Accumulation of Au-NPs produces the characteristic red bands, enabling visual detection of SBM. It was found that the ability of HO to differentiate perfect-matched DNA and SBM was increased dramatically by incorporating double-target DNA binding sequences in the loop of HO. The signal ratio between perfect-matched DNA and SBM was up to 28, which is much higher than that of conventional HO or molecular beacon. The approach was applied to detect the mutation sites, Arg142Cys and Gly529Ile, of transglutaminase 1 gene in autosomal recessive congenital ichthyosis. The results presented here show that the new HO is a potential molecular recognition probe for the future development of nucleic acid-based biosensors and bioassays. The approach can be used for point-of-care diagnosis of genetic diseases and detecting infectious agents or warning against bio-warfare agents. © 2012 Elsevier B.V.


Fang C.,Shandong University | Fang C.,Queen Mary, University of London | Wen G.,Queen Mary, University of London | Wen G.,Guangzhou University | And 7 more authors.
Cardiovascular Research | Year: 2013

AimsGrowing evidence suggests a close association of plaque angiogenesis with atherosclerotic plaque formation and progression, and an important role of matrix metalloproteinase (MMP) in angiogenesis and atherosclerosis. We attempted to investigate the functional involvements of MMP8 in angiogenesis.Methods and resultsKnockdown of MMP8 in human umbilical vein endothelial cells (HuVECs) with MMP-8 shRNA lentivirus resulted in a decrease in in vitro capillary-like network formation, cell proliferation and migration, and impaired its capacity of in vivo angiogenesis. Less nuclear accumulation of β-catenin and lower β-catenin target gene expression levels was observed in the HuVECs expressing lower levels of endogenous MMP8. Knockdown of endogenous MMP8 in HuVECs down-regulated platelet/endothelial cell adhesion molecule-1 (PECAM-1) expression by converting less angiotensin I to II, which is an inducer for PECAM-1 gene expression. Aortic rings isolated from MMP8-/-/apoE -/- mice had less endothelial cell sprouting, and endothelial cells in MMP8-/-/apoE-/- mice had a lower ability to migrate into Matrigel plugs and less capacity of proliferation and angiogenesis. Moreover, immunohistochemical analyses revealed that MMP8 was expressed in microvessels within human atherosclerotic plaques and aneurysm. Finally, analyses of MMP8-/-/apoE-/- and MMP8+/+/ apoE-/- mice fed a Western diet for 12 weeks showed that MMP8-deficient mice had small lesion size and less endothelial cells within atherosclerotic lesions.ConclusionWe demonstrated for the first time that MMP8 plays an important role in angiogenesis in vitro and in vivo. Our findings provide new insights into the molecular mechanisms of plaque angiogenesis and suggest that MMP8 is a potential therapeutic target of cardiovascular diseases. © 2013 Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2013.


He Y.,Guangzhou Institute of Dermatology | He Y.,North Dakota State University | Zhang X.,Guangzhou Institute of Dermatology | Zeng K.,Southern Medical University | And 4 more authors.
Biosensors and Bioelectronics | Year: 2011

We report a sensitive method for visual detection of mercury ions (II) (Hg 2+) in aqueous solution by using gold nanoparticles (Au-NPs) and thymine (T)-rich hairpin DNA probes. The thiolated hairpin DNA probe was immobilized on the Au-NP surface through a self-assembling method. Another thymine-rich, digoxin-labeled DNA probe was introduced to form DNA duplexes on the Au-NP surface with thymine-Hg 2+-thymine (T-Hg 2+-T) coordination in the presence of Hg 2+. The Au-NPs associated with the formed duplexes were captured on the test zone of a lateral flow strip biocomponent (LFSB) by immunoreaction events between the digoxin on the duplexes and anti-digoxin antibodies on the LFSB. The accumulation of Au-NPs produced a characteristic red band on the test zone, enabling visual detection of Hg 2+ without instrumentation. A detection limit of 0.1nM was obtained under optimal experimental conditions. This method provides a simple, rapid, sensitive approach for the detection of Hg 2+ and shows great promise for point-of-care and in-field detection of environmentally toxic mercury. © 2011 Elsevier B.V.


He Y.,Guangzhou Institute of Dermatology | He Y.,North Dakota State University | Zeng K.,Southern Medical University | Zhang S.,Guangzhou Institute of Dermatology | And 4 more authors.
Biosensors and Bioelectronics | Year: 2012

Here, we describe a simple and sensitive approach for visual detection of gene mutations based on isothermal strand-displacement polymerase reactions (ISDPR) and lateral flow strip (LFS). The concept was first demonstrated by detecting the R156H-mutant gene of keratin 10 in Epidermolytic hyperkeratosis (EHK). In the presence of biotin-modified hairpin DNA and digoxin-modified primer, the R156H-mutant DNA triggered the ISDPR to produce numerous digoxin- and biotin-attached duplex DNA products. The product was detected on the LFS through dual immunoreactions (anti-digoxin antibody on the gold nanoparticle (Au-NP) and digoxin on the duplex, anti-biotin antibody on the LFS test zone and biotin on the duplex). The accumulation of Au-NPs produced the characteristic red band, enabling visual detection of the mutant gene without instrumentation. After systematic optimization of the ISDPR experimental conditions and the parameters of the assay, the current approach was capable of detecting as low as 1-fM R156H-mutant DNA within 75. min without instrumentation. Differentiation of R156H- and R156C-mutant DNA on the R156 mutation site was realized by using fluorescein- and biotin-modified hairpin probes in the ISDPR process. The approach thus provides a simple, sensitive, and low-cost tool for the detection of gene mutations. © 2011 Elsevier B.V.


He Y.,Guangzhou Institute of Dermatology | He Y.,Southern Medical University | He Y.,North Dakota State University | Zeng K.,Southern Medical University | And 5 more authors.
Analytical Chemistry | Year: 2010

We report a simple, fast, and sensitive approach for visual detection of single-nucleotide polymorphism (SNP) based on hairpin oligonucleotide- functionalized gold nanoparticle (HO-Au-NP) and lateral flow strip biosensor (LFSB). The results presented here expand on prior work (Mao, X., Xu, H., Zeng, Q., Zeng, L., and Liu, G. Chem. Commun. 2009, 3065-3067.) by providing new approach to prepare HO-Au-NP conjugates with a deoxyadenosine triphosphate (dATP) blocker, which shortens the preparation time of the conjugates from 50 to 8 h and lowers the detection limit 500 times. A hairpin oligonucleotide modified with a thiol at the 5?-end and a biotin at the 3?-end was conjugated with Au-NP through a self-assembling process. Following a blocking step with dATP, the hairpin structure of HO and dATP embed the biotin groups, and make the biotin groups in close proximity to the Au-NP surface, leading to the biotins being "inactive". The strategy of detecting SNP depends on the unique molecular recognition properties of HO to the perfect-matched DNA and single-base-mismatched DNA to generate different quantities of "active" biotin groups on the Au-NP surface. After hybridization reactions, the Au-NPs associated with the activated biotins are captured on the test zone of LFSB via the specific reaction between the activated biotin and preimmobilized streptavidin. Accumulation of Au-NPs produces the characteristic red bands, enabling visual detection of SNP. The preparations of HO-Au-NP conjugates with dATP and the parameters of assay were optimized systematically, and the abilities of detecting SNP were examined in details. The current approach is capable of discriminating as low as 10 pM of perfect-matched DNA and single-base-mismatched DNA within 25 min without instrumentation. Moreover, the approach provides a lower background and higher selectivity compared to the current molecular beacon-based SNP detection. The protocol should facilitate the simple, fast, and cost-effective screening of important SNPs and could readily find wide applications in molecular diagnosis laboratories and in point-of-care testing (field testing). © 2010 American Chemical Society.


He Y.,Guangzhou Institute of Dermatology | He Y.,North Dakota State University | Zhang S.,Guangzhou Institute of Dermatology | Zhang X.,Guangzhou Institute of Dermatology | And 6 more authors.
Biosensors and Bioelectronics | Year: 2011

In this article, we describe an ultrasensitive nucleic acid biosensor (NAB) based on horseradish peroxidase (HRP)-gold nanoparticle (Au-NP) dual labels and lateral flow strip biosensor (LFSB). The results presented here expand on prior work (Mao et al., 2009a) by optimizing the preparation of HRP-Au-NP-DNA conjugates. It was found that sodium dodecyl sulfate (SDS) and the immobilization sequence of thiolated DNA and HRP on the Au-NP surface played very important roles to improve the sensitivity of the assay. After systematic optimization, the detection limit of current approach is 1000 times lower than that in prior work. Deposition of insoluble enzymatic catalytic product (red colored chromogen) on the captured Au-NPs at the test zone of LFSB offers a dramatic visual enhancement. Combining enzyme catalytic amplification with unique optical properties of Au-NPs, the NAB was capable of detecting of 0.01-pM target DNA without instrumentation. The NAB thus provides a rapid, sensitive, low-cost tool for the detection of nucleic acid samples. It shows great promise for in-field and point-of-care diagnosis of genetic diseases and for the detection of infectious agents. © 2010 Elsevier B.V.


Sanquan Z.,Guangzhou Institute of Dermatology
National Medical Journal of China | Year: 2014

Objective: To explore the effects of cell cycle distribution and expression of cell cycle related proteins before and after transglutaminase 1 (TGM1) gene silencing by small interfering RNA (siRNA) in immortalized human keratinocytes (HaCaT cells). Methods: Before and after RNA interference (RNAi) silencing TGM1 gene expression in HaCaT cells, the changes of cell cycle status were detected by flow cytometry. And the expressions of cell cycle related proteins cyclin Dl, cyclin Bl and CDK4 were detected by immunocytochemistry and Western blot. Results: After TGM1 silencing, the HaCaT cells increased in G0/G1 phase (78. 27% ± 1. 83% vs 56. 84 % ± 2. 72% and 57. 19% ± 3. 72%, both P <0. 05) while decreased in S phases (32. 78% ±5. 48% vs 57. 32% ±2. 91% and 55. 71 % ±2. 84%, both P <0. 05) and G2/M phases(3. 66% ±0. 30% vs 9. 39% ±0. 68% and 9. 77% ±0. 52%,both P < 0. 05). Moreover, arrest of cell cycle was induced in S phase. After TGM1 silencing, cell proliferation was significantly inhibited while wild-type TGM1 displayed an accelerated growth rate. Inmmnohistochemistry indicated that cyclin Dl, cyclin Bl and CDK4 had a strongly negative expression after transfecting with TGM1 siRNA. Western blot indicated that a very low endogenous expression of cyclin Dl, cyclin Bl and CDK4 proteins was observed after transfecting with TGM1 siRNA. Conclusions: TGM1 siRNA may block the cell cycle of HaCaT cells. It suggests that TGM1 expression in HaCaT cells are closely related with cell cycle.

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