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1.  Dynamic changes of HBV markers and HBV DNA load in infants born to HBsAg(+) mothers: can positivity of HBsAg or HBV DNA at birth be an indicator for HBV infection of infants? 
BMC Infectious Diseases  2013;13:524.
Neither HBV DNA nor HBsAg positivity at birth is an accurate marker for HBV infection of infants. No data is available for continuous changes of HBV markers in newborns to HBsAg(+) mothers. This prospective, multi-centers study aims at observing the dynamic changes of HBV markers and exploring an early diagnostic marker for mother-infant infection.
One hundred forty-eight HBsAg(+) mothers and their newborns were enrolled after mothers signed the informed consent forms. Those infants were received combination immunoprophylaxis (hepatitis B immunoglobulin [HBIG] and hepatitis B vaccine) at birth, and then followed up to 12 months. Venous blood of the infants (0, 1, 7, and 12 months of age) was collected to test for HBV DNA and HBV markers.
Of the 148 infants enrolled in our study, 41 and 24 infants were detected as HBsAg(+) and HBV DNA(+) at birth, respectively. Nine were diagnosed with HBV infection after 7 mo follow-up. Dynamic observation of the HBV markers showed that HBV DNA and HBsAg decreased gradually and eventually sero-converted to negativity in the non-infected infants, whereas in the infected infants, HBV DNA and HBsAg were persistently positive, or higher at the end of follow-up. At 1 mo, the infants with anti-HBs(+), despite positivity for HBsAg or HBV DNA at birth, were resolved after 12 mo follow-up, whereas all the nine infants with anti-HBs(−) were diagnosed with HBV infection. Anti-HBs(−) at 1 mo showed a higher positive likelihood ratio for HBV mother-infant infection than HBV DNA and/or HBsAg at birth.
Negativity for anti-HBs at 1 mo can be considered as a sensitive and early diagnostic indictor for HBV infection in the infants with positive HBV DNA and HBsAg at birth, especially for those infants with low levels of HBV DNA load and HBsAg titer.
PMCID: PMC3829094  PMID: 24195671
2.  SOAPdenovo2: an empirically improved memory-efficient short-read de novo assembler 
GigaScience  2012;1:18.
There is a rapidly increasing amount of de novo genome assembly using next-generation sequencing (NGS) short reads; however, several big challenges remain to be overcome in order for this to be efficient and accurate. SOAPdenovo has been successfully applied to assemble many published genomes, but it still needs improvement in continuity, accuracy and coverage, especially in repeat regions.
To overcome these challenges, we have developed its successor, SOAPdenovo2, which has the advantage of a new algorithm design that reduces memory consumption in graph construction, resolves more repeat regions in contig assembly, increases coverage and length in scaffold construction, improves gap closing, and optimizes for large genome.
Benchmark using the Assemblathon1 and GAGE datasets showed that SOAPdenovo2 greatly surpasses its predecessor SOAPdenovo and is competitive to other assemblers on both assembly length and accuracy. We also provide an updated assembly version of the 2008 Asian (YH) genome using SOAPdenovo2. Here, the contig and scaffold N50 of the YH genome were ~20.9 kbp and ~22 Mbp, respectively, which is 3-fold and 50-fold longer than the first published version. The genome coverage increased from 81.16% to 93.91%, and memory consumption was ~2/3 lower during the point of largest memory consumption.
PMCID: PMC3626529  PMID: 23587118
Genome; Assembly; Contig; Scaffold; Error correction; Gap-filling
3.  Conditioned medium of human adipose-derived mesenchymal stem cells mediates protection in neurons following glutamate excitotoxicity by regulating energy metabolism and GAP-43 expression 
Metabolic Brain Disease  2014;29:193-205.
Glutamate excitotoxicity has been implicated as one of the pathological mechanisms contributing to neuronal cell death and is involved in many neurological disorders. Stem cell transplantation is a promising approach for the treatment of nervous system damage or diseases. Previous studies have shown that mesenchymal stem cells (MSCs) have important therapeutic effects in experimental animal and preclinical disease model of central nervous system pathology. However, it is not well understood whether neurogenesis of MSCs or MSC conditioned-medium (CM) containing microparticles mediates therapeutic effects. Here, we investigated the neuroprotective effects of human adipose-derived MSCs (AMSCs) on cortical neurons using models of glutamate excitotoxicity. Following exposure to glutamate (100 μM, 15 min), cortical neurons were co-cultured with either AMSCs separated by a semiporous membrane (prohibiting direct cell-cell contact) or with AMSC-CM for 18 h. Compared to untreated control groups, AMSCs and AMSC-CM partially and similarly reduced neuronal cell damages, as indicated by reduced LDH release, a decreased number of trypan-positive cells and a decline in the number of apoptotic nuclei. Protection by CM was associated with increased GAP-43 expression and an elevated number of GAP-43-positive neurites. Furthermore, CM increased levels of ATP, NAD+ and NADH and the ratio of NAD+/NADH, while preventing a glutamate-induced decline in mitochondrial membrane potential. These results demonstrate that AMSC-CM mediates direct neuroprotection by inhibiting neuronal cell damage/apoptosis, promoting nerve regeneration and repair, and restoring bioenergy following energy depletion caused by glutamate excitotoxicity.
PMCID: PMC3930846  PMID: 24458787
Excitotoxicity; Cortical neurons; AMSCs; Neuroprotection; GAP-43; Energy metabolism
4.  Influence of Pericarp, Cotyledon and Inhibitory Substances on Sharp Tooth Oak (Quercus aliena var. acuteserrata) Germination 
PLoS ONE  2012;7(10):e47682.
In order to explore the mechanism of delayed and uneven germination in sharp tooth oak (Quercus aliena var. acuteserrata) (STO), mechanical scarification techniques were used to study STO root and shoot germination and growth. The techniques used were: removing cup scar (RS), removing the pericarp (RP), and cutting off 1/2 (HC) and 2/3 (TC) cotyledons. Germination percentage and root and shoot length for Chinese cabbage (Beassica pekinensis) seeds (CCS) were also investigated for CCS cultivated in a Sanyo growth cabinet watered by distilled water and 80% methanol extracts from the acorn embryo, cotyledon and pericarp with concentrations of 1.0 g, 0.8 g, 0.6 g and 0.4 g dry acorn weight per ml methanol. The results showed that the majority of roots and shoots from acorns with RP and HC treatment emerged two weeks earlier, more simultaneously, and their total emergences were more than 46% and 28% higher, respectively. TC accelerated root and shoot emergence time and root length, but root and shoot germination rate and shoot height had no significant difference from the control. Positive consequences were not observed on all indices of RS treatment. The germination rates of CCS watered by 1.0 g·ml−1 methanol extracts from the embryo and cotyledon were significantly lower than those from the pericarp, and all concentrations resulted in decreased growth of root and shoot. Methanol extracts from pericarp significantly reduced root length of CCS, but presented little response in germination percentage and shoot length. The inhibitory effect was gradually increased with the increasing concentration of the methanol extract. We conclude that both the mechanical restriction of the pericarp and the presence of germination inhibitors in the embryo, cotyledon and pericarp are the causes for delayed and asynchronous germination of STO acorns.
PMCID: PMC3485030  PMID: 23133517
5.  Highly Efficient and Specific Genome Editing in Silkworm Using Custom TALENs 
PLoS ONE  2012;7(9):e45035.
Establishment of efficient genome editing tools is essential for fundamental research, genetic engineering, and gene therapy. Successful construction and application of transcription activator-like effector nucleases (TALENs) in several organisms herald an exciting new era for genome editing. We describe the production of two active TALENs and their successful application in the targeted mutagenesis of silkworm, Bombyx mori, whose genetic manipulation methods are parallel to those of Drosophila and other insects. We will also show that the simultaneous expression of two pairs of TALENs generates heritable large chromosomal deletion. Our results demonstrate that (i) TALENs can be used in silkworm and (ii) heritable large chromosomal deletions can be induced by two pairs of TALENs in whole organisms. The generation and the high frequency of TALENs-induced targeted mutagenesis in silkworm will promote the genetic modification of silkworm and other insect species.
PMCID: PMC3445556  PMID: 23028749
6.  Peripheral Nerve Injury Leads to Working Memory Deficits and Dysfunction of the Hippocampus by Upregulation of TNF-α in Rodents 
Neuropsychopharmacology  2011;36(5):979-992.
Patients with chronic pain usually suffer from working memory deficits, which may decrease their intellectual ability significantly. Despite intensive clinical studies, the mechanism underlying this form of memory impairment remains elusive. In this study, we investigated this issue in the spared nerve injury (SNI) model of neuropathic pain, a most common form of chronic pain. We found that SNI impaired working memory and short-term memory in rats and mice. To explore the potential mechanisms, we studied synaptic transmission/plasticity in hippocampus, a brain region critically involved in memory function. We found that frequency facilitation, a presynaptic form of short-term plasticity, and long-term potentiation at CA3–CA1 synapses were impaired after SNI. Structurally, density of presynaptic boutons in hippocampal CA1 synapses was reduced significantly. At the molecular level, we found that tumor necrosis factor-α (TNF-α) increased in cerebrospinal fluid, in hippocampal tissue and in plasma after SNI. Intracerebroventricular or intrahippocampal injection of recombinant rat TNF mimicked the effects of SNI in naive rats, whereas inhibition of TNF-α or genetic deletion of TNF receptor 1 prevented both memory deficits and synaptic dysfunction induced by SNI. As TNF-α is critical for development of neuropathic pain, we suggested that the over-production of TNF-α following peripheral nerve injury might lead to neuropathic pain and memory deficits, simultaneously.
PMCID: PMC3077267  PMID: 21289602
spared nerve injury; chronic neuropathic pain; working memory; long-term potentiation; presynaptic boutons; tumor necrosis factor-α; pain/analgesics; learning & memory; neuropharmacology; plasticity; peripheral nerve injury; chronic neuropathic pain; working memory; long-term potentiation; presynaptic boutons; tumor necrosis factor alpha
7.  Comparison of Immunogenicity between Codon Optimized HIV-1 Thailand Subtype B gp140 and gp145 Vaccines 
Vaccine  2007;25(26):4949-4959.
HIV-1 pandemic posed an unprecedent challenge to the global health and it is believed that an effective vaccine will be the final solution against HIV-1. HIV-1 envelope is the primary immunogen in developing neutralization antibody based HIV vaccine. To define the suitable Env derived immunogen, we systemically compared the immunogenicity of gp140 and gp145 in a DNA vaccination alone and a prime-boost modalities. 2 DNA vaccines and 2 recombinant Tiantan vaccinia vaccines (rTTV) were constructed for vaccination of female Balb/c mice. Elispot assay was used to read out the T cell immunity and ELISA assay was used to quantify antibody immunity. PLL (poly-L-Leucine)-ELISA assay was used in linear antibody epitope mapping. Mice primed with gp145 tended to elicit more Env-specific T cells responses than those primed with gp140, significant difference was observed in DNA immunization alone. The ultimate T cell responses in prime-boost regimen tends to be determined mainly by the priming efficacy. Linear antibody epitope mapping displayed that sera raised by gp145 priming were vigorously reactive to more peptides than that by gp140. Our data demonstrated HIV-1 Thailand B-derived gp145 may raise higher T-cell responses and broader linear peptide-specific antibody responses than gp140 does. However, it remains to be determined that how these observations are relevant to neutralization antibody activities.
PMCID: PMC1961633  PMID: 17350736
HIV-1; Vaccine; Envelope; Immunogen design
8.  Glutathione S-transferase M1 null genotype meta-analysis on gastric cancer risk 
Diagnostic Pathology  2014;9:122.
Glutathione S-transferases (GSTs) have proved to be involved in the detoxifying several carcinogens and may play an important role in carcinogenesis of cancer. Previous studies on the association between Glutathione S-transferase M1 (GSTM1) polymorphism and gastric cancer (GC) risk reported inconclusive results. To get a precise result, we conducted this present meta-analysis through pooling all eligible studies.
A comprehensive databases of Pubmed, Embase, Web of Science, and the Chinese Biomedical Database (CBM) were searched for case–control studies investigating the association between GSTM1 null genotype and GC risk. Odds ratios (OR) and 95% confidence intervals (95% CI) were used to assess this possible association. A χ2-based Q-test was used to examine the heterogeneity assumption. Begg’s and Egger’s test were used to examine the potential publication bias. The leave-one-out sensitivity analysis was conducted to determine whether our assumptions or decisions have a major effect on the results of present work. Statistical analyses were performed with the software program STATA 12.0.
A total of 47 eligible case–control studies were identified, including 6,678 cases and 12,912 controls. Our analyses suggested that GSTM1 null genotype was significantly associated with increased risk of GC (OR = 1.186, 95% CI = 1.057-1.329, Pheterogenetiy = 0.000, P = 0.004). Significant association was also found in Asians (OR = 1.269, 95% CI = 1.106-1.455, Pheterogenetiy = 0.002, P = 0.001). However, GSTM1 null genotype was not contributed to GC risk in Caucasians (OR = 1.115, 95% CI = 0.937-1.326, Pheterogenetiy = 0.000, P = 0.222). In the subgroup analysis stratified by sources of controls, significant association was detected in hospital-based studies (OR = 1.355, 95% CI = 1.179-1.557, Pheterogenetiy = 0.001, P = 0.000), while there was no significant association detected in population-based studies (OR = 1.017, 95% CI = 0.862-1.200, Pheterogenetiy = 0.000, P = 0.840).
This meta-analysis showed the evidence that GSTM1 null genotype contributed to the development of GC.
Virtual Slides
The virtual slide(s) for this article can be found here:
PMCID: PMC4079641  PMID: 24948179
GSTM1; Polymorphism; Gastric cancer; Risk; Meta-analysis
9.  The Potential Biomarker Panels for Identification of Major Depressive Disorder (MDD) Patients with and without Early Life Stress (ELS) by Metabonomic Analysis 
PLoS ONE  2014;9(5):e97479.
The lack of the disease biomarker to support objective laboratory tests still constitutes a bottleneck in the clinical diagnosis and evaluation of major depressive disorder (MDD) and its subtypes. We used metabonomic techniques to screen the diagnostic biomarker panels from the plasma of MDD patients with and without early life stress (ELS) experience.
Plasma samples were collected from 25 healthy adults and 46 patients with MDD, including 23 patients with ELS and 23 patients without ELS. Furthermore, gas chromatography/mass spectrometry (GC/MS) coupled with multivariate statistical analysis was used to identify the differences in global plasma metabolites among the 3 groups.
The distinctive metabolic profiles exist either between healthy subjects and MDD patients or between the MDD patients with ELS experience (ELS/MDD patients) and the MDD patients without it (non-ELS/MDD patients), and some diagnostic panels of feature metabolites' combination have higher predictive potential than the diagnostic panels of differential metabolites.
These findings in this study have high potential of being used as novel laboratory diagnostic tool for MDD patients and it with ELS or not in clinical application.
PMCID: PMC4037179  PMID: 24870353
10.  Breath Ketone Testing: A New Biomarker for Diagnosis and Therapeutic Monitoring of Diabetic Ketosis 
BioMed Research International  2014;2014:869186.
Background. Acetone, β-hydroxybutyric acid, and acetoacetic acid are three types of ketone body that may be found in the breath, blood, and urine. Detecting altered concentrations of ketones in the breath, blood, and urine is crucial for the diagnosis and treatment of diabetic ketosis. The aim of this study was to evaluate the advantages of different detection methods for ketones, and to establish whether detection of the concentration of ketones in the breath is an effective and practical technique. Methods. We measured the concentrations of acetone in the breath using gas chromatography-mass spectrometry and β-hydroxybutyrate in fingertip blood collected from 99 patients with diabetes assigned to groups 1 (−), 2 (±), 3 (+), 4 (++), or 5 (+++) according to urinary ketone concentrations. Results. There were strong relationships between fasting blood glucose, age, and diabetic ketosis. Exhaled acetone concentration significantly correlated with concentrations of fasting blood glucose, ketones in the blood and urine, LDL-C, creatinine, and blood urea nitrogen. Conclusions. Breath testing for ketones has a high sensitivity and specificity and appears to be a noninvasive, convenient, and repeatable method for the diagnosis and therapeutic monitoring of diabetic ketosis.
PMCID: PMC4037575  PMID: 24900994
11.  Genome Sequence of Luteimonas huabeiensis HB-2, a Novel Species of Luteimonas with High Oil Displacement Efficiency 
Genome Announcements  2014;2(2):e00152-14.
Luteimonas huabeiensis HB-2 is a novel and newly isolated strain, which shows a superior property of oil displacement. Here, we present a 4.3-Mb assembly of its genome. The key genes for phospholipid and fatty acid metabolism were annotated, which are crucial for crude oil emulsification and recovery.
PMCID: PMC3945508  PMID: 24604652
12.  Changing community health service delivery in economically less-developed rural areas in China: impact on service use and satisfaction 
BMJ Open  2014;4(2):e004148.
To evaluate the impact of a model of rural community health service (CHS) on the use and acceptability of primary healthcare services.
Two adjacent rural counties in China.
5842 residents in 2009 and 3807 in 2010 from 980 households in 7 intervention townships and 49 villages; 2232 residents in 2009 and 2315 in 2010 from 628 households in 3 comparison townships and 9 villages. All residents were approached to participate, with no significant differences in age or sex between groups.
Multilevel intervention in 2009 including training rural practitioners, encouraging clinic improvements, providing clinical guidelines, standards and subsidies.
Data collection
Surveys of community members from randomly sampled households in 2009 and 2010.
Primary outcome measures
Satisfaction with and utilisation of outpatient and public health services.
Factor analysis confirmed two components of satisfaction. Univariate and multilevel analysis was used.
Satisfaction scores for intervention county respondents increased from 21.4 (95% CI 21.1 to 21.7) to 22.1 (95% CI 21.7 to 22.4) with no change in comparison area. In multilevel analysis, satisfaction with patient-centred care was associated with chronic disease, shorter waiting times and county. Satisfaction with clinic environment and cost was associated with female gender, shorter waiting times but not county. The proportion of children receiving immunisation in intervention village clinics increased from 42.5% (95% CI 27.9% to 47.1%) to 59.2% (95% CI 53.8% to 64.6%) whereas this decreased in comparison villages (16.5%; 95% CI 10.3% to 22.7% to 6.0%; 95% CI 1.3% to 10.7%). Antenatal visits increased in intervention villages (from 69.0%, 95% CI 65.8% to 73.1% to 75.8%, 95% CI 72.2% to 79.4%) with no change in comparison villages.
Introduction of a CHS model adapted to economically less-developed rural areas was associated with some improvements in satisfaction with care and use of some village-based public health services. Further research is needed to determine its public health impact and application to other areas.
PMCID: PMC3939668  PMID: 24583760
Primary Care; Public Health
13.  PAQR3 Modulates Insulin Signaling by Shunting Phosphoinositide 3-Kinase p110α to the Golgi Apparatus 
Diabetes  2013;62(2):444-456.
Phosphoinositide 3-kinase (PI3K) mediates insulin actions by relaying signals from insulin receptors (IRs) to downstream targets. The p110α catalytic subunit of class IA PI3K is the primary insulin-responsive PI3K implicated in insulin signaling. We demonstrate here a new mode of spatial regulation for the p110α subunit of PI3K by PAQR3 that is exclusively localized in the Golgi apparatus. PAQR3 interacts with p110α, and the intracellular targeting of p110α to the Golgi apparatus is reduced by PAQR3 downregulation and increased by PAQR3 overexpression. Insulin-stimulated PI3K activity and phosphoinositide (3,4,5)-triphosphate production are enhanced by Paqr3 deletion and reduced by PAQR3 overexpression in hepatocytes. Deletion of Paqr3 enhances insulin-stimulated phosphorylation of AKT and glycogen synthase kinase 3β, but not phosphorylation of IR and IR substrate-1 (IRS-1), in hepatocytes, mouse liver, and skeletal muscle. Insulin-stimulated GLUT4 translocation to the plasma membrane and glucose uptake are enhanced by Paqr3 ablation. Furthermore, PAQR3 interacts with the domain of p110α involved in its binding with p85, the regulatory subunit of PI3K. Overexpression of PAQR3 dose-dependently reduces the interaction of p85α with p110α. Thus, PAQR3 negatively regulates insulin signaling by shunting cytosolic p110α to the Golgi apparatus while competing with p85 subunit in forming a PI3K complex with p110α.
PMCID: PMC3554364  PMID: 23086038
14.  Genome-Wide Analyses of Radioresistance-Associated miRNA Expression Profile in Nasopharyngeal Carcinoma Using Next Generation Deep Sequencing 
PLoS ONE  2013;8(12):e84486.
Rapidly growing evidence suggests that microRNAs (miRNAs) are involved in a wide range of cancer malignant behaviours including radioresistance. Therefore, the present study was designed to investigate miRNA expression patterns associated with radioresistance in NPC.
The differential expression profiles of miRNAs and mRNAs associated with NPC radioresistance were constructed. The predicted target mRNAs of miRNAs and their enriched signaling pathways were analyzed via biological informatical algorithms. Finally, partial miRNAs and pathways-correlated target mRNAs were validated in two NPC radioreisitant cell models.
50 known and 9 novel miRNAs with significant difference were identified, and their target mRNAs were narrowed down to 53 nasopharyngeal-/NPC-specific mRNAs. Subsequent KEGG analyses demonstrated that the 53 mRNAs were enriched in 37 signaling pathways. Further qRT-PCR assays confirmed 3 down-regulated miRNAs (miR-324-3p, miR-93-3p and miR-4501), 3 up-regulated miRNAs (miR-371a-5p, miR-34c-5p and miR-1323) and 2 novel miRNAs. Additionally, corresponding alterations of pathways-correlated target mRNAs were observed including 5 up-regulated mRNAs (ICAM1, WNT2B, MYC, HLA-F and TGF-β1) and 3 down-regulated mRNAs (CDH1, PTENP1 and HSP90AA1).
Our study provides an overview of miRNA expression profile and the interactions between miRNA and their target mRNAs, which will deepen our understanding of the important roles of miRNAs in NPC radioresistance.
PMCID: PMC3868612  PMID: 24367666
15.  Correlation of Cytokine Levels and Microglial Cell Infiltration during Retinal Degeneration in RCS Rats 
PLoS ONE  2013;8(12):e82061.
Microglial cells, which are immunocompetent cells, are involved in all diseases of the central nervous system. During their activation in various diseases, a variety of soluble factors are released. In the present study, the correlation between cytokine levels and microglial cell migration in the course of retinal degeneration of Royal College of Surgeons (RCS) rats was evaluated. MFG-E8 and CD11b were used to confirm the microglial cells. In the retina of RCS rats, the mRNA expression of seven genes (MFG-E8 and its integrins αυ and ß5, CD11b and the cytokines TNF-α, IL-1ß, and MCP-1) formed almost similar bimodal peak distributions, which were centred at P7 and P45 to P60. In contrast, in rdy rats, which comprised the control group, a unimodal peak distribution centred at P14 was observed. The gene expression accompanied the activation and migration of microglial cells from the inner to the outer layer of the retina during the process of degeneration. Principal component analysis and discriminant function analysis revealed that the expression of these seven genes, especially TNF-α and CD11b, positively correlated with retinal degeneration and microglial activity during retinal degeneration in RCS rats, but not in the control rats. Furthermore, linear regression analysis demonstrated a significant correlation between the expression of these genes and the activation of microglial cells in the dystrophic retina. Our findings suggest that the suppression of microglial cells and the blockade of their cytotoxic effects may constitute a novel therapeutic strategy for treating photoreceptor death in various retinal disorders.
PMCID: PMC3862575  PMID: 24349184
16.  Effects of Bone Marrow-Derived Mesenchymal Stem Cells on the Axonal Outgrowth through Activation of PI3K/AKT Signaling in Primary Cortical Neurons Followed Oxygen-Glucose Deprivation Injury 
PLoS ONE  2013;8(11):e78514.
Transplantation with bone marrow-derived mesenchymal stem cells (BMSCs) improves the survival of neurons and axonal outgrowth after stroke remains undetermined. Here, we investigated whether PI3K/AKT signaling pathway is involved in these therapeutic effects of BMSCs.
Methodology/Principal Findings
(1) BMSCs and cortical neurons were derived from Sprague-Dawley rats. The injured neurons were induced by Oxygen–Glucose Deprivation (OGD), and then were respectively co-cultured for 48 hours with BMSCs at different densities (5×103, 5×105/ml) in transwell co-culture system. The average length of axon and expression of GAP-43 were examined to assess the effect of BMSCs on axonal outgrowth after the damage of neurons induced by OGD. (2) The injured neurons were cultured with a conditioned medium (CM) of BMSCs cultured for 24 hours in neurobasal medium. During the process, we further identified whether PI3K/AKT signaling pathway is involved through the adjunction of LY294002 (a specific phosphatidylinositide-3-kinase (PI3K) inhibitor). Two hours later, the expression of pAKT (phosphorylated AKT) and AKT were analyzed by Western blotting. The length of axons, the expression of GAP-43 and the survival of neurons were measured at 48 hours.
Both BMSCs and CM from BMSCs inreased the axonal length and GAP-43 expression in OGD-injured cortical neurons. There was no difference between the effects of BMSCs of 5×105/ml and of 5×103/ml on axonal outgrowth. Expression of pAKT enhanced significantly at 2 hours and the neuron survival increased at 48 hours after the injured neurons cultured with the CM, respectively. These effects of CM were prevented by inhibitor LY294002.
BMSCs promote axonal outgrowth and the survival of neurons against the damage from OGD in vitro by the paracrine effects through PI3K/AKT signaling pathway.
PMCID: PMC3827028  PMID: 24265694
17.  The effects of HIV Tat DNA on regulating the immune response of HIV DNA vaccine in mice 
Virology Journal  2013;10:297.
HIV trans-activator protein (Tat) is the crucial factor to control HIV transcription, and is usually considered as an important immunogen for the design of HIV vaccine. Recent studies reported some special bio-activities of Tat protein on immunoregulation. However, to date, few studies have focused on exploring the effects of Tat expression plasmid (pTat) on regulating the immune responses induced by HIV DNA vaccines. In this study, our main objective is to investigate the immunoregulation mediated by pTat in mice.
Four gene-coding plasmids (pTat, pGag, pEnv and pPol) were constructed, and the gene expression was detected by western blot method. The effects of pTat on regulating the immune responses to antigens Gag, Env, Pol were assessed by enzyme-linked immunospot and enzyme-linked immunosorbent assay. The data was analysed by one-way analysis of variance.
After two immunizations, mice vaccinated with antigen expressing plasmid (pGag, pEnv or pPol) plus pTat exhibited significantly stronger IFN-gamma response than that vaccinated with the corresponding antigen alone. Moreover, mice receiving two injections of antigen plus pTat exhibited the same strong IFN-gamma response as those receiving three injections of antigen alone did. Furthermore, addition of pTat not only induced a more balanced Th1 and Th2 response, but also broadened IgG subclass responses to antigens Gag and Pol.
pTat exhibited the appreciable effects on modulating immune responses to HIV antigens Gag, Env and Pol, providing us interesting clues on how to optimize HIV DNA vaccine.
PMCID: PMC3851266  PMID: 24073803
HIV DNA vaccine; Tat expression plasmid; T cell response; IgG subclass; Th polarization
18.  Delayed ischemic preconditioning contributes to renal protection by upregulation of miR-21 
Kidney international  2012;82(11):1167-1175.
Delayed ischemic preconditioning effectively protects kidneys from ischemia-reperfusion injury but the mechanism underlying renal protection remains poorly understood. Here we examined the in vivo role of microRNA miR-21 in the renal protection conferred by delayed ischemic preconditioning in mice. A 15 minute renal ischemic preconditioning significantly increased the expression of miR-21 by 4 hours and substantially attenuated ischemia-reperfusion injury induced 4 days later. A locked nucleic acid-modified anti-miR-21 given at the time of ischemic preconditioning knocked down miR-21 and significantly exacerbated subsequent ischemia-reperfusion injury in the mouse kidney. Knockdown of miR-21 resulted in significant upregulation of programmed cell death protein 4, a pro-apoptotic target gene of miR-21, and substantially increased tubular cell apoptosis. Hypoxia inducible factor-1α in the kidney was activated after ischemic preconditioning and blockade of its activity with a decoy abolished the up-regulation of miR-21 in cultured human renal epithelial cells treated with the inducer cobalt chloride. In the absence of ischemic preconditioning, knockdown of miR-21 alone did not significantly affect ischemia-reperfusion injury in the mouse kidney. Thus, upregulation of miR-21 contributes to the protective effect of delayed ischemic preconditioning against subsequent renal ischemia-reperfusion injury.
PMCID: PMC3777822  PMID: 22785173
19.  S1PR1-STAT3 signaling is crucial for myeloid cell colonization at future metastatic sites 
Cancer Cell  2012;21(5):642-654.
Recent studies underscore the importance of myeloid cells in rendering distant organs hospitable for disseminating tumor cells to colonize. However, what enables myeloid cells to have an apparently superior capacity to colonize distant organs is unclear. Here we show that S1PR1-STAT3 upregulation in tumor cells induces factors that activate S1PR1-STAT3 in various cells in pre-metastatic sites, leading to pre-metastatic niche formation. Targeting either S1PR1 or STAT3 in myeloid cells disrupts existing pre-metastatic niches. S1PR1-STAT3 pathway enables myeloid cells to intravasate, prime the distant organ microenvironment and mediate sustained proliferation and survival of their own and other stromal cells at future metastatic sites. Analyzing tumor-free lymph nodes from cancer patients shows elevated myeloid infiltrates, STAT3 activity and increased survival signal.
PMCID: PMC3360884  PMID: 22624714
20.  Knockdown of Regulator of Cullins-1 (ROC1) Expression Induces Bladder Cancer Cell Cycle Arrest at the G2 Phase and Senescence 
PLoS ONE  2013;8(5):e62734.
Regulator of Cullins-1 (ROC1) is a key subunit in the Cullin-RING ligase (CRL) protein complex. Overexpression of ROC1 protein is associated with tumor progression and poor prognosis of non-muscle invasive bladder transitional cell carcinoma (NMIBC). This study was designed to assess the effects of ROC1 knockdown in bladder cancer cells and to determine the potential mechanisms involved. A total of 112 bladder cancer tissue specimens were recruited for immunohistochemical analyses of ROC1 overexpression. Bladder cancer cell lines were used to knockdown ROC1 expression using ROC1 siRNA. Our data showed that ROC1 knockdown remarkably inhibited bladder cancer cell growth, arrested cells at the G2 phase of the cell cycle, and induced the p53-dependent cell senescence. Molecularly, G2 arrest was associated with upregulation of p21, p27, cyclin B1, and Cdc2 proteins. ROC1 knockdown induced-senescence functioned through p53/p21 pathway. Knockdown of p21 expression partially rescued ROC1 knockdown-induced growth inhibition in cancer cells. Furthermore, nude mouse xenograft analyses confirmed these in vitro data. In conclusion, data from the current study indicate that ROC1 plays an essential role in bladder cancer progression and could serve as a novel anticancer target for bladder transitional cell carcinoma (BTCC).
PMCID: PMC3648563  PMID: 23667514
21.  Aberrant Functional Organization within and between Resting-State Networks in AD 
PLoS ONE  2013;8(5):e63727.
Altered functional characteristics have been reported in amnestic mild cognitive impairment (aMCI) and Alzheimer’s disease (AD); nonetheless, comprehensive analyses of the resting-state networks (RSNs) are rare. This study combined multiple imaging modalities to investigate the functional and structural changes within each RSN and between RSNs in aMCI/AD patients. Eight RSNs were identified from functional MRI data from 35 AD, 18 aMCI and 21 normal control subjects using independent component analysis. We compared functional connectivity (FC) within each RSN and found decreased FC in the several cognitive-related RSNs in AD, including the bilateral precuneus of the precuneus network, the posterior cingulate cortex and left precuneus of the posterior default mode network (DMN), and the left superior parietal lobule of the left frontoparietal network (LFP). We further compared the grey matter volumes and amplitudes of low-frequency fluctuations of these regions and found decreases in these measures in AD. Importantly, we found decreased inter-network connectivity between the visual network and the LFP and between the anterior and posterior DMNs in AD. All indices in aMCI patients were numerically between those of controls and AD patients. These results suggest that the brain networks supporting complex cognitive processes are specifically and progressively impaired over the course of AD, and the FC impairments are present not only within networks but also between networks.
PMCID: PMC3647055  PMID: 23667665
22.  A functional variomics tool for discovering drug resistance genes and drug targets 
Cell reports  2013;3(2):577-585.
Comprehensive discovery of genetic mechanisms of drug resistance and identification of in vivo drug targets represent significant challenges. Here we present a functional variomics technology in the model organism Saccharomyces cerevisiae. This tool analyzes numerous genetic variants and effectively tackles both problems simultaneously. Using this tool, we discovered almost all genes that, due to mutations or modest overexpression, confer resistance to rapamycin, cycloheximide, and amphotericin B. Most significant among the resistance genes were drug targets, including multiple targets of a given drug. With amphotericin B, we discovered the highly conserved membrane protein Pmp3 as a potent resistance factor and a possible novel target. Widespread application of this tool should allow rapid identification of conserved resistance mechanisms and targets of many more compounds. New genes and alleles that confer resistance to other stresses can also be discovered. Similar tools in other systems such as human cell lines will also be useful.
PMCID: PMC3594652  PMID: 23416056
23.  Essential Role of MFG-E8 for Phagocytic Properties of Microglial Cells 
PLoS ONE  2013;8(2):e55754.
Milk fat globule factor-E8 (MFG-E8) has been regarded as a key factor involved in the phagocytosis of apoptotic cells. We induced a lentivirus into the microglial cells for the augmentation or abrogation of MFG-E8 expression in mouse microglial cells, and investigated phagocytosis of phosphatidylserine tagged human red blood cells (hRBCs) in co-cultures. Increased MFG-E8 levels were associated with a significant increase in phagocytic activity compared to the controls. Conversely, phagocytosis dramitically decreased due to the abrogation of MFG-E8. In addition, the expression of the inflammatory cytokines, TNF-α and IL-1β, also increased or decreased in the microglial cells with the augmentation or abrogation of MFG-E8, respectively. Our findings indicate that the enhanced expression of MFG-E8 could increase phagocytosis of apoptotic cells; conversely, the rate of phagocytosis and the expression of inflammatory cytokines decreased when MFG-E8 expression was knocked down. Our results confirm that MFG-E8 plays an important role in phagocytosis, and possibly serves as an essential signal molecule for microglial cells.
PMCID: PMC3565973  PMID: 23405209
24.  c-Jun Amino-Terminal Kinase-1 Mediates Glucose-Responsive Upregulation of the RNA Editing Enzyme ADAR2 in Pancreatic Beta-Cells 
PLoS ONE  2012;7(11):e48611.
A-to-I RNA editing catalyzed by the two main members of the adenosine deaminase acting on RNA (ADAR) family, ADAR1 and ADAR2, represents a RNA-based recoding mechanism implicated in a variety of cellular processes. Previously we have demonstrated that the expression of ADAR2 in pancreatic islet β-cells is responsive to the metabolic cues and ADAR2 deficiency affects regulated cellular exocytosis. To investigate the molecular mechanism by which ADAR2 is metabolically regulated, we found that in cultured β-cells and primary islets, the stress-activated protein kinase JNK1 mediates the upregulation of ADAR2 in response to changes of the nutritional state. In parallel with glucose induction of ADAR2 expression, JNK phosphorylation was concurrently increased in insulin-secreting INS-1 β-cells. Pharmacological inhibition of JNKs or siRNA knockdown of the expression of JNK1 prominently suppressed glucose-augmented ADAR2 expression, resulting in decreased efficiency of ADAR2 auto-editing. Consistently, the mRNA expression of Adar2 was selectively reduced in the islets from JNK1 null mice in comparison with that of wild-type littermates or JNK2 null mice, and ablation of JNK1 diminished high-fat diet-induced Adar2 expression in the islets from JNK1 null mice. Furthermore, promoter analysis of the mouse Adar2 gene identified a glucose-responsive region and revealed the transcription factor c-Jun as a driver of Adar2 transcription. Taken together, these results demonstrate that JNK1 serves as a crucial component in mediating glucose-responsive upregulation of ADAR2 expression in pancreatic β-cells. Thus, the JNK1 pathway may be functionally linked to the nutrient-sensing actions of ADAR2-mediated RNA editing in professional secretory cells.
PMCID: PMC3490865  PMID: 23139803
25.  The Essential Role of Mbd5 in the Regulation of Somatic Growth and Glucose Homeostasis in Mice 
PLoS ONE  2012;7(10):e47358.
Methyl-CpG binding domain protein 5 (MBD5) belongs to the MBD family proteins, which play central roles in transcriptional regulation and development. The significance of MBD5 function is highlighted by recent studies implicating it as a candidate gene involved in human 2q23.1 microdeletion syndrome. To investigate the physiological role of Mbd5, we generated knockout mice. The Mbd5-deficient mice showed growth retardation, wasting and pre-weaning lethality. The observed growth retardation was associated with the impairment of GH/IGF-1 axis in Mbd5-null pups. Conditional knockout of Mbd5 in the brain resulted in the similar phenotypes as whole body deletion, indicating that Mbd5 functions in the nervous system to regulate postnatal growth. Moreover, the mutant mice also displayed enhanced glucose tolerance and elevated insulin sensitivity as a result of increased insulin signaling, ultimately resulting in disturbed glucose homeostasis and hypoglycemia. These results indicate Mbd5 as an essential factor for mouse postnatal growth and maintenance of glucose homeostasis.
PMCID: PMC3471830  PMID: 23077600

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