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1.  Cross-linking of CD81 by HCV-E2 protein inhibits human intrahepatic plasmacytoid dendritic cells response to CpG-ODN 
Cellular immunology  2013;284(0):98-103.
Plasmacytoid dendritic cells (pDCs) are reported to be defective in HCV-infected patients, the mechanisms of which remain poorly understood. We isolated liver derived mononuclear cells (LMNCs) and pDCs from normal liver tissues of benign tumor dissections and liver transplant donors. Isolated pDCs and LMNCs were cultured with precoated HCV envelop protein E2 (HCV-E2) or anti-CD81 mAb in the presence of CpG-ODN. Our results show that cross-linking of CD81 by either HCV-E2 or anti-CD81 mAb inhibits IFN-α secretion in CpG-induced pDCs; down-regulates HLA-DR, CD80 and CD86 expression in pDCs; and suppresses CpG-ODN induced proliferation and survival of pDCs. The blockade of CD81 by soluble anti-CD81 antibody restores pDCs response to CpG-ODN. These results suggest that HCV E2 protein interacts with CD81 to inhibit pDC maturation, activation, and IFN-α production, and may thereby contribute to the impaired innate anti-viral immune response in HCV infection.
PMCID: PMC3979323  PMID: 23954883
Plasmacytoid dendritic cells (pDCs); Hepatitis C virus envelop protein (HCV-E); CpG oligodeoxynucleotides (CpG-ODN); Toll-like receptor 9 (TLR9); Cross-linking
2.  Fetal PGC-1α Overexpression Programs Adult Pancreatic β-Cell Dysfunction 
Diabetes  2013;62(4):1206-1216.
Adult β-cell dysfunction, a hallmark of type 2 diabetes, can be programmed by adverse fetal environment. We have shown that fetal glucocorticoids (GCs) participate in this programming through inhibition of β-cell development. Here we have investigated the molecular mechanisms underlying this regulation. We showed that GCs stimulate the expression of peroxisome proliferator–activated receptor-γ coactivator-1α (PGC-1α), a coregulator of the GCs receptor (GR), and that the overexpression of PGC-1α represses genes important for β-cell development and function. More precisely, PGC-1α inhibited the expression of the key β-cell transcription factor pancreatic duodenal homeobox 1 (Pdx1). This repression required the GR and was mediated through binding of a GR/PGC-1α complex to the Pdx1 promoter. To explore PGC-1α function, we generated mice with inducible β-cell PGC-1α overexpression. Mice overexpressing PGC-1α exhibited at adult age impaired glucose tolerance associated with reduced insulin secretion, decreased β-cell mass, and β-cell hypotrophy. Interestingly, PGC-1α expression in fetal life only was sufficient to impair adult β-cell function whereas β-cell PGC-1α overexpression from adult age had no consequence on β-cell function. Altogether, our results demonstrate that the GR and PGC-1α participate in the fetal programming of adult β-cell function through inhibition of Pdx1 expression.
PMCID: PMC3609553  PMID: 23274887
3.  Calcium Channel Autoantibodies Predicted Sudden Cardiac Death and All-Cause Mortality in Patients with Ischemic and Nonischemic Chronic Heart Failure 
Disease Markers  2014;2014:796075.
The purpose of this study was to evaluate whether CC-AAbs levels could predict prognosis in CHF patients. A total of 2096 patients with CHF (841 DCM patients and 1255 ICM patients) and 834 control subjects were recruited. CC-AAbs were detected and the relationship between CC-AAbs and patient prognosis was analyzed. During a median follow-up time of 52 months, there were 578 deaths. Of these, sudden cardiac death (SCD) occurred in 102 cases of DCM and 121 cases of ICM. The presence of CC-AAbs in patients was significantly higher than that of controls (both P < 0.001). Multivariate analysis revealed that positive CC-AAbs could predict SCD (HR 3.191, 95% CI 1.598–6.369 for DCM; HR 2.805, 95% CI 1.488–5.288 for ICM) and all-cause mortality (HR 1.733, 95% CI 1.042–2.883 for DCM; HR 2.219, 95% CI 1.461–3.371 for ICM) in CHF patients. A significant association between CC-AAbs and non-SCD (NSCD) was found in ICM patients (HR = 1.887, 95% CI 1.081–3.293). Our results demonstrated that the presence of CC-AAbs was higher in CHF patients versus controls and corresponds to a higher incidence of all-cause death and SCD. Positive CC-AAbs may serve as an independent predictor for SCD and all-cause death in these patients.
PMCID: PMC3966345
4.  Discrimination of the Expression of Paralogous microRNA Precursors That Share the Same Major Mature Form 
PLoS ONE  2014;9(3):e90591.
MicroRNAs (miRNAs) are a class of small non-coding RNAs generated from endogenous transcripts that form hairpin structures. The hairpin precursor is processed into two mature miRNAs that form major/minor duplexes. Mature miRNAs regulate gene expression by cleaving mRNA or repressing protein translation. Numerous miRNAs have been discovered via deep sequencing. Many miRNAs are produced from multiple genome sites. These miRNAs are grouped into paralogous families of miRNAs that generate the same major mature form within organisms. Currently, no method of distinguishing the expression of these miRNAs is available.
In the present study, strategies were developed to discriminate and quantify the expression of paralogous miRNA precursors. First, paralogous miRNA precursors that were differentially expressed in tissues were identified through analysis of the coexpression scores of their major and minor forms based on deep sequencing data. Then the precursors were identified by monitoring the expression of their host gene or minor form using real-time PCR. Finally, precursors were identified by assessing the expression of clusters of miRNA members. These approaches were used to distinguish miR-128-1 and miR-128-2 as well as miR-194-1 and miR-194-2. The mechanism of transcription related to the differential expression of miR-194-1 and miR-194-2 was also investigated.
This is the first report to distinguish paralogous miRNA copies by analyzing the expression of major-minor pairs, the host gene, and miRNA clusters. Discriminating paralogous precursors can provide useful information for investigating the mechanisms that regulate miRNA gene expression under different physiological and pathological conditions.
PMCID: PMC3940925  PMID: 24594692
5.  Single Nucleotide Polymorphisms of Toll-Like Receptor 7 and Toll-Like Receptor 9 in Hepatitis C Virus Infection Patients from Central China 
Yonsei Medical Journal  2014;55(2):428-434.
To analyze the correlation of polymorphisms of toll-like receptor 7 (TLR7) (rs179009) and toll-like receptor 9 (TLR9) (rs187084) in hepatitis C virus (HCV) infections in the Han population.
Materials and Methods
The genotypes of TLR7IVS2-151 in HCV infection were detected by Sanger sequencing using polymerase chain reaction-restriction fragment length polymorphism to determine the TLR9 T-1486C single nucleotide polymorphisms (SNP) for all enrolled patients.
We found no significant difference between males with spontaneous clearance of HCV versus those chronically infected [χ2=2.71, p=0.10, odd ratios (OR)=0.58, 95% confidence interval (CI) 0.31-1.11]. However, significant differences were found for the distribution of TLR7 (rs179009) in females (χ2=9.46, p=0.01). In females, a significant difference was also found between chronic hepatitis C and those with spontaneous clearance of HCV in terms of TLR7 IVS2-151G/A allele frequencies (χ2=9.50, p=0.00, OR=0.46, 95% CI 0.28-0.75). In HCV-infected patients, no significant association was found between the frequency of TLR9 genotypes and alleles.
The site of TLR7 IVS2-151 (rs179009) G/A may be a factor for susceptibility of chronic HCV in the female Han population. TLR9T-1486C (rs18084) SNP may not play a major role in HCV infection. However, individual risk profiles for HCV infection did vary by sex and this relationship should be further investigated.
PMCID: PMC3936647  PMID: 24532514
Hepatitis C virus; single nucleotide polymorphism; TLR7; TLR9
6.  Association between Time of Pay-for-Performance for Patients and Community Health Services Use by Chronic Patients 
PLoS ONE  2014;9(2):e89793.
Pay-for-performance for patients is a cost-effective means of improving health behaviours. This study examined the association between the pay time for performance for patients and CHS use by chronic patients.
A cross-sectional study was undertaken to estimate distribution characteristics of CHS use in 2011 and collect data of socio-demographic characteristics (sex, age, education level, occupation, disposable personal income in 2011, distance between home and community health agency), chronic disease number, and time of pay-for-performance for patients. Participants were 889 rural adults with hypertension or type II diabetes aged 35 and above. Standardized CHS use means chronic patients use CHS at least once per quarter.
Patients who received incentives prior to services had 2.724 times greater odds of using standardized CHS than those who received incentives after services (95%CI, 1.986–3.736, P<0.001). For all subgroups (socio-demographic characteristics and chronic disease number), patients who received incentives prior to services were more likely to use standardized CHS than those receiving incentives after services.
Pay time for performance for patients was associated with CHS use by chronic patients. Patients receiving incentive prior to services were more likely to use standardized CHS. And pay time should not be ignored when the policy on pay-for-performance for patients is designed.
PMCID: PMC3938507  PMID: 24587037
7.  Hydrogen Sulfide Inhibits Formaldehyde-Induced Endoplasmic Reticulum Stress in PC12 Cells by Upregulation of SIRT-1 
PLoS ONE  2014;9(2):e89856.
Formaldehyde (FA), a well-known environmental pollutant, has been classified as a neurotoxic molecule. Our recent data demonstrate that hydrogen sulfide (H2S), the third gaseous transmitter, has a protective effect on the neurotoxicity of FA. However, the exact mechanisms underlying this protection remain largely unknown. Endoplasmic reticulum (ER) stress has been implicated in the neurotoxicity of FA. Silent mating type information regulator 2 homolog 1 (SIRT-1), a histone deacetylases, has various biological activities, including the extension of lifespan, the modulation of ER stress, and the neuroprotective action.
We hypothesize that the protection of H2S against FA-induced neurotoxicity involves in inhibiting ER stress by upregulation of SIRT-1. The present study attempted to investigate the protective effect of H2S on FA-induced ER stress in PC12 cells and the contribution of SIRT-1 to the protection of H2S against FA-induced injuries, including ER stress, cytotoxicity and apoptosis.
Principal Findings
We found that exogenous application of sodium hydrosulfide (NaHS; an H2S donor) significantly attenuated FA-induced ER stress responses, including the upregulated levels of glucose-regulated protein 78, C/EBP homologous protein, and cleaved caspase-12 expression. We showed that NaHS upregulates the expression of SIRT-1 in PC12 cells. Moreover, the protective effects of H2S on FA-elicited ER stress, cytotoxicity and apoptosis were reversed by Sirtinol, a specific inhibitor of SIRT-1.
These data indicate that H2S exerts its protection against the neurotoxicity of FA through overcoming ER stress via upregulation of SIRT-1. Our findings provide novel insights into the protective mechanisms of H2S against FA-induced neurotoxicity.
PMCID: PMC3938548  PMID: 24587076
8.  Preoperative diagnosis and intraoperative protection of nonrecurrent laryngeal nerve: A review of 5 cases 
Nonrecurrent laryngeal nerve (NRLN) is a risk factor for nerve injury during thyroidectomy or parathyroidectomy. It is usually associated with abnormal vasculature that can be identified by several imaging methods. The aim of this study was to retrospectively analyze the preoperative diagnosis and intraoperative protection of NRLN.
Of the 7169 patients who underwent thyroid surgery at our hospital between August 2008 and January 2013, 5 patients with NRLN were identified. Preoperative chest X-rays, neck ultrasonography (US), and computed tomography (CT) findings were reviewed. NRLNs were carefully and systematically searched for in surgery.
Preoperative CT predicted NRLN in all 5 cases (100% accuracy). The detection rate of NRLN by CT was 0.4% (5/1170). NRLNs were confirmed in surgery. All of them were right-sided NRLN with type IIA variant. The CT scans clearly revealed the vascular anomalies. The review of US images suggested that vascular anomalies could be identified on the images in 1 patient. No postoperative complications occurred in any patient.
The preoperative CT scan was a reliable and effective method for identifying abnormal vasculature to indirectly predict NRLN. Combining the CT and US findings with adequate surgical technique may help to reduce the risk of nerve damage, in addition to preventing nerve palsy.
PMCID: PMC3930603  PMID: 24518037
Abnormal Vascular; Computed Tomography; Parathyroidectomy; Thyroidectomy; Recurrent Laryngeal Nerve Injuries
9.  A Novel Flexible Virtual Fixtures for Teleoperation 
The Scientific World Journal  2014;2014:897242.
This paper proposed a novel spatial-motion-constraints virtual fixtures (VFs) method for the human-machine interface collaborative technique. In our method, two 3D flexible VFs have been presented: warning pipe and safe pipe. And a potential-collision-detection method based on two flexible VFs has been proposed. The safe pipe constructs the safe workspace dynamically for the robot, which makes it possible to detect the potential collision between the robot and the obstacles. By calculating the speed and the acceleration of the robot end-effecter (EE), the warning pipe can adjust its radius to detect the deviation from the EE to the reference path. These spatial constraints serve as constraint conditions for constrained robot control. The approach enables multiobstacle manipulation task of telerobot in precise interactive teleoperation environment. We illustrate our approach on a teleoperative manipulation task and analyze the performance results. The performance-comparison experimental results demonstrate that the control mode employing our method can assist the operator more precisely in teleoperative tasks. Due to the properties such as collision avoidance and safety, operators can complete the tasks more efficiently along with reduction in operating tension.
PMCID: PMC3944649
10.  Incidence and Metastasis of Cutaneous Malignant Melanoma with Respect to ABO Blood Groups: A Case-Controlled Study in Northeast of China 
PLoS ONE  2014;9(2):e88096.
ABO blood groups have been suggested to contribute to the development of certain tumors; however, the associations between ABO blood groups and the incidence and metastases of cutaneous malignant melanomas have not been fully evaluated in Chinese populations. Thus, we investigated these associations with a case-controlled study in northeast of China.
A total of 482 patients with cutaneous malignant melanoma and 3,068 healthy- controls were enrolled for the study between 2001 and 2012 at The Tumor Hospital of Harbin Medical University. A multivariate logistic model was used to evaluate adjusted odds ratios (ORs) and 95% confidence intervals (CI) for the incidence and metastases of cutaneous malignant melanoma.
Blood type A individuals had higher tumor incidence and metastasis compared to those with blood type O (OR = 1.575; 95% CI = 1.208–2.053, p = 0.001; OR = 2.004; 95% CI = 1.032–3.889, p = 0.040), after adjusting for age, gender, smoking status and alcohol consumption.
Blood type A was associated with higher incidence and metastasis of cutaneous malignant melanoma but future studies are needed to examine the mechanisms linking cutaneous malignant melanoma to ABO blood types.
PMCID: PMC3917876  PMID: 24516588
11.  A Prolyl-isomerase Mediates Dopamine-dependent Plasticity and Cocaine Motor Sensitization 
Cell  2013;154(3):637-650.
Synaptic plasticity induced by cocaine and other drugs underlies addiction. Here we elucidate molecular events at synapses that cause this plasticity and the resulting behavioral response to cocaine in mice. In response to D1 dopamine receptor signaling that is induced by drug administration, the glutamate receptor protein mGluR5 is phosphorylated by MAP kinase, which we show potentiates Pin1-mediated prolyl isomerization of mGluR5 in instances where the product of an activity-dependent gene, Homer1a, is present to enable Pin1-mGluR5 interaction. These biochemical events potentiate NMDA receptor-mediated currents that underlie synaptic plasticity and cocaine-evoked motor sensitization as tested in mice with relevant mutations. The findings elucidate how a coincidence of signals from the nucleus and the synapse can render mGluR5 accessible to activation with consequences for drug-induced dopamine responses, and point to depotentiation at corticostriatal synapses as a possible therapeutic target for treating addiction.
PMCID: PMC3785238  PMID: 23911326
12.  Association of promoter methylation statuses of congenital heart defect candidate genes with Tetralogy of Fallot 
Although a lower methylation level of whole genome has been demonstrated in Tetralogy of Fallot (TOF) patients, little is known regarding changes in specific gene DNA methylation profiles and the possible associations with TOF. In current study, the promoter methylation statuses of congenital heart defect (CHD) candidate genes were measured in order to further understand epigenetic mechanisms that may play a role in the development of TOF.
The methylation levels of CHD candidate genes were measured using the Sequenom MassARRAY platform. QRT-PCR was used to analyze the mRNA levels of CHD candidate genes in the right ventricular myocardium of TOF cases and normal controls.
Methylation status analysis was performed on the promoter regions of 71 CHD candidate genes (113 amplicons). We found significant differences in methylation status, between TOF cases and controls, in 26 amplicons (26 genes) (p < 0.05). Of the 26 amplicons, 17 were up regulated and 9 were down regulated. Additionally, 14 of them were located in the CpG islands, 7 were located in the CpG island shores, and 5 were covering the regions near the transcription start site (TSS). The methylation status was subsequently confirmed and mRNA levels were measured for 7 represented candidate genes, including EGFR, EVC2, NFATC2, NR2F2, TBX5, CFC1B and GJA5. The methylation values of EGFR, EVC2, TBX5 and CFC1B were significantly correlated with their mRNA levels (p < 0.05).
Aberrant promoter methylation statuses of CHD candidate genes presented in TOF cases may contribute to the TOF development and have potential prognostic and therapeutic significance for TOF disease.
PMCID: PMC3915623  PMID: 24479926
DNA methylation; Congenital heart defect candidate genes; Tetralogy of Fallot
13.  Morphology and growth speed of hcp domains during shock-induced phase transition in iron 
Scientific Reports  2014;4:3628.
Emergence and time evolution of micro-structured new-phase domains play a crucial role in determining the macroscopic physical and mechanical behaviors of iron under shock compression. Here, we investigate, through molecular dynamics simulations and theoretical modelings, shock-induced phase transition process of iron from body-centered-cubic (bcc) to hexagonal-close-packed (hcp) structure. We present a central-moment method and a rolling-ball algorithm to calculate and analyze the morphology and growth speed of the hcp phase domains, and then propose a phase transition model to clarify our derived growth law of the phase domains. We also demonstrate that the new-phase evolution process undergoes three distinguished stages with different time scales of the hcp phase fraction in the system.
PMCID: PMC3887381  PMID: 24406750
14.  Improvement of the suture-occluded method in rat models of focal cerebral ischemia-reperfusion 
The aim of the present study was to provide a simple method of establishing a rat model for focal cerebral ischemia-reperfusion (FCIR). The suture-occluded method was used to establish FCIR in male Sprague-Dawley rats. An incision was made over the bifurcation of the common carotid artery (CCA), through which a suture was inserted up to the internal carotid artery (ICA). The suture remained in the skin subsequent to model establishment and was withdrawn to the CCA to enable reperfusion. The reliability of the rat model was assessed via analysis of nerve function, tetrazolium (TTC) staining and pathological examination. Following FCIR in rats, the resulting neurological impairments were observed. TTC staining revealed infarcts and pathological examination revealed typical pathological changes. This modified method was simple, reliable and, therefore, may be used to investigate FCIR.
PMCID: PMC3919944  PMID: 24520263
rat; focal cerebral ischemia-reperfusion; model
15.  A Bcl-xL-Drp1 complex regulates synaptic vesicle membrane dynamics during endocytosis 
Nature cell biology  2013;15(7):773-785.
Following exocytosis, the rate of recovery of neurotransmitter release is determined by vesicle retrieval from the plasma membrane and by recruitment of vesicles from reserve pools within the synapse, the latter of which is dependent on mitochondrial ATP. The Bcl-2 family protein Bcl-xL, in addition to its role in cell death, regulates neurotransmitter release and recovery in part by increasing ATP availability from mitochondria. We now find, however, that, Bcl-xL directly regulates endocytotic vesicle retrieval in hippocampal neurons through protein/protein interaction with components of the clathrin complex. Our evidence suggests that, during synaptic stimulation, Bcl-xL translocates to clathrin-coated pits in a calmodulin-dependent manner and forms a complex of proteins with the GTPase Drp1, Mff and clathrin. Depletion of Drp1 produces misformed endocytotic vesicles. Mutagenesis studies suggest that formation of the Bcl-xL-Drp1 complex is necessary for the enhanced rate of vesicle endocytosis produced by Bcl-xL, thus providing a mechanism for presynaptic plasticity.
PMCID: PMC3725990  PMID: 23792689
16.  Negative control of mast cell degranulation and the anaphylactic response by the phosphatase lipin1 
European journal of immunology  2012;43(1):240-248.
Mast cells play a critical role in the pathogenesis of allergic diseases. How mast cell function is regulated is still not well understood. Both phosphatidic acid (PA) and diacylglycerol (DAG) are important second messengers involved in mast cell activation. Lipin1 is a phosphatidate phosphatase that hydrolyzes PA to produce DAG. The role of lipin1 in mast cell function has been unknown. In this report, we show that lipin1 is an important and selective inhibitor of mast cell degranulation. Lipin1 deficiency enhanced FcεRI-mediated β-hexosaminidase and prostaglandin D2 release from mast cells in vitro and exacerbated the passive systemic anaphylaxis reaction in vivo. However, Lipin1 deficiency did not exert obvious effects on IL-6 or TNF-α production following FcεRI engagement. FcεRI-induced PKC and SNAP-23 phosphorylation was augmented in the lipin1-deficient mast cells. Moreover, inhibition of PKC activity reduced SNAP-23 phosphorylation and mast cell degranulation in lipin1 deficient mast cells. Together, our findings suggest that lipin1 may negatively control mast cell degranulation and anaphylactic response through inhibiting the PKC-SNAP-23 pathway.
PMCID: PMC3748934  PMID: 23065777
Mast cells; lipin1; Phosphatidic acid; PKC; SNAP-23
17.  PKA: Lessons Learned after Twenty Years 
Biochimica et biophysica acta  2013;1834(7):1271-1278.
The first protein kinase structure, solved in 1991, revealed the fold that is shared by all members of the eukaryotic protein kinase superfamily and showed how the conserved sequence motifs cluster mostly around the active site. This structure of the PKA catalytic (C) subunit showed also how a single phosphate integrated the entire molecule. Since then the EPKs have become a major drug target, second only to the G-protein coupled receptors. Although PKA provided a mechanistic understanding of catalysis that continues to serve as a prototype for the family, by comparing many active and inactive kinases we subsequently discovered a hydrophobic spine architecture that is a characteristic feature of all active kinases. The ways in which the regulatory spine is dynamically assembled is the defining feature of each protein kinase. Protein kinases have thus evolved to be molecular switches, like the G-proteins, and unlike metabolic enzymes which have evolved to be efficient catalysis. PKA also shows how the dynamic tails surround the core and serve as essential regulatory elements. The phosphorylation sites in PKA, introduced both co- and post-translationally, are very stable. The resulting C-subunit is then package as an inhibited holoenzyme with cAMP-binding regulatory (R) subunits so that PKA activity is regulated exclusively by cAMP, not by the dynamic turnover of an activation loop phosphate. We could not understand activation and inhibition without seeing structures of R:C complexes; however, to appreciate the structural uniqueness of each R2:C2 holoenzyme required solving structures of tetrameric holoenzymes. It is these tetrameric holoenzymes that are localized to discrete sites in the cell, typically by A Kinase Anchoring Proteins where they create discrete foci for PKA signaling. Understanding these dynamic macromolecular complexes is the challenge that we now face.
PMCID: PMC3763834  PMID: 23535202
18.  Bone Mineral Density of the Spine in 11,898 Chinese Infants and Young Children: A Cross-Sectional Study 
PLoS ONE  2013;8(12):e82098.
Bone mineral density (BMD) increases progressively during childhood and adolescence and is affected by various genetic and environmental factors. The aim of this study was to establish reference values for lumbar BMD in healthy Chinese infants and young children and investigate its influencing factors.
Methods and Findings
Healthy children aged 0 to 3 years who underwent regular physical examinations at the Child Health Care Clinic of Hubei Maternal and Child Health Hospital (N = 11,898) were recruited for this study. We also chose 379 preterm infants aged 0 to 1 years to preliminarily explore the development of BMD in this special population. BMD (g/cm2) measurements of the lumbar spine (L2–L4) were carried out with dual-energy X-ray absorptiometry and a questionnaire was administered to full-term children's parents to gather information on various nutritional and lifestyle factors as well as mothers' nutritional supplement use during pregnancy. Lumbar BMD significantly increased with age among both boys and girls (p<0.05), with fastest growth observed during the first postnatal year. There was no significant difference in lumbar BMD between boys and girls of similar age (p>0.05), either among healthy reference children or preterm infants. However, BMD values in preterm infants were significantly lower than those in term infants 3 to 8 months old (p<0.05) after adjustment for gestational age. Multivariable linear regression analysis indicated significant positive associations between lumbar BMD of healthy children and the child's age and current weight, mother's weight gain during pregnancy, birth weight, children's outdoor activity duration and children's physical activity duration.
Our study provides reference values of lumbar BMD for healthy Chinese children aged 0 to 3 years and identifies several influencing factors.
PMCID: PMC3855755  PMID: 24324752
19.  Lack of RNase L Attenuates Macrophage Functions 
PLoS ONE  2013;8(12):e81269.
Macrophages are one of the major cell types in innate immunity against microbial infection. It is believed that the expression of proinflammatory genes such as tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL–6, and cyclooxygenase-2 (Cox-2) by macrophages is also crucial for activation of both innate and adaptive immunities. RNase L is an interferon (IFN) inducible enzyme which is highly expressed in macrophages. It has been demonstrated that RNase L regulates the expression of certain inflammatory genes. However, its role in macrophage function is largely unknown.
Bone marrow-derived macrophages (BMMs) were generated from RNase L+/+and −/− mice. The migration of BMMs was analyzed by using Transwell migration assays. Endocytosis and phagocytosis of macrophages were assessed by using fluorescein isothiocyanate (FITC)-Dextran 40,000 and FITC-E. coli bacteria, respectively. The expression of inflammatory genes was determined by Western Blot and ELISA. The promoter activity of Cox-2 was measured by luciferase reporter assays.
Lack of RNase L significantly decreased the migration of BMMs induced by M-CSF, but at a less extent by GM-CSF and chemokine C-C motif ligand-2 (CCL2). Interestingly, RNase L deficient BMMs showed a significant reduction of endocytic activity to FITC-Dextran 40,000, but no any obvious effect on their phagocytic activity to FITC-bacteria under the same condition. RNase L impacts the expression of certain genes related to cell migration and inflammation such as transforming growth factor (TGF)-β, IL-1β, IL-10, CCL2 and Cox-2. Furthermore, the functional analysis of the Cox-2 promoter revealed that RNase L regulated the expression of Cox-2 in macrophages at its transcriptional level. Taken together, our findings provide direct evidence showing that RNase L contributes to innate immunity through regulating macrophage functions.
PMCID: PMC3852499  PMID: 24324683
20.  Role of mTOR Downstream Effector Signaling Molecules in Francisella Tularensis Internalization by Murine Macrophages 
PLoS ONE  2013;8(12):e83226.
Francisella tularensis is an infectious, gram-negative, intracellular microorganism, and the cause of tularemia. Invasion of host cells by intracellular pathogens like Francisella is initiated by their interaction with different host cell membrane receptors and the rapid phosphorylation of different downstream signaling molecules. PI3K and Syk have been shown to be involved in F. tularensis host cell entry, and both of these signaling molecules are associated with the master regulator serine/threonine kinase mTOR; yet the involvement of mTOR in F. tularensis invasion of host cells has not been assessed. Here, we report that infection of macrophages with F. tularensis triggers the phosphorylation of mTOR downstream effector molecules, and that signaling via TLR2 is necessary for these events. Inhibition of mTOR or of PI3K, ERK, or p38, but not Akt signaling, downregulates the levels of phosphorylation of mTOR downstream targets, and significantly reduces the number of F. tularensis cells invading macrophages. Moreover, while phosphorylation of mTOR downstream effectors occurs via the PI3K pathway, it also involves PLCγ1 and Ca2+ signaling. Furthermore, abrogation of PLC or Ca2+ signaling revealed their important role in the ability of F. tularensis to invade host cells. Together, these findings suggest that F. tularensis invasion of primary macrophages utilize a myriad of host signaling pathways to ensure effective cell entry.
PMCID: PMC3849438  PMID: 24312679
21.  Toll-Like Receptor 4/Stem Cell Antigen 1 Signaling Promotes Hematopoietic Precursor Cell Commitment to Granulocyte Development during the Granulopoietic Response to Escherichia coli Bacteremia 
Infection and Immunity  2013;81(6):2197-2205.
In response to severe bacterial infection, bone marrow hematopoietic activity shifts toward promoting granulopoiesis. The underlying cell signaling mechanisms remain obscure. To study the role of Toll-like receptor 4 (TLR4)/stem cell antigen-1 (Sca-1) signaling in this process, bacteremia was induced in mice by intravenous injection of Escherichia coli. A subgroup of animals also received intravenous 5-bromo-2-deoxyuridine (BrdU). In a separate set of experiments, bone marrow lineage-negative (lin−) stem cell growth factor receptor-positive (c-kit+) Sca-1− cells containing primarily common myeloid progenitors were cultured in vitro without or with E. coli lipopolysaccharide (LPS). In genotypic background control mice, bacteremia significantly upregulated Sca-1 expression by lin− c-kit+ cells, as reflected by a marked increase in BrdU-negative lin− c-kit+ Sca-1+ cells in the bone marrow. In mice with the TLR4 gene deletion, this bacteremia-evoked Sca-1 response was blocked. In vitro, LPS induced a dose-dependent increase in Sca-1 expression by cultured marrow lin− c-kit+ Sca-1− cells. LPS-induced upregulation of Sca-1 expression was regulated at the transcriptional level. Inhibition of c-Jun N-terminal kinase/stress-activated protein kinase (JNK) activity with the specific inhibitor SP600125 suppressed LPS-induced upregulation of Sca-1 expression by marrow lin− c-kit+ Sca-1− cells. Engagement of Sca-1 with anti-Sca-1 antibodies enhanced the expression of Sfpi1 spleen focus-forming virus (SFFV) proviral integration 1 (PU.1) in marrow lin− c-kit+ Sca-1− cells cultured with LPS. Sca-1 null mice failed to maintain the marrow pool of granulopoietic cells following bacteremia. These results demonstrate that TLR4/Sca-1 signaling plays an important role in the regulation of hematopoietic precursor cell programming and their enhancement of granulocyte lineage commitment in response to E. coli bacteremia.
PMCID: PMC3676006  PMID: 23545304
22.  Effects of extracellular pressure and alcohol on the microglial response to inflammatory stimulation 
American journal of surgery  2012;204(5):10.1016/j.amjsurg.2012.07.010.
TBI induces a neuroinflammatory response frequently associated with increased intracranial pressure (ICP). We investigated the effects of alcohol and increased extracellular pressure on murine BV-2 microglial proliferation and cytokine responses to lipopolysaccharide (LPS) stimulation. BV-2 cells were cultured under 0 or 30mmHg increased extracellular pressure without or with ethanol (100mM) or LPS (10ng/ml) for 24 hours. We assessed cell proliferation via MTS assay and secretion of the pro-inflammatory cytokines TNF-α, IL-6, and MCP-1 by ELISA. Increased pressure and LPS stimulation each promoted proliferation. Ethanol pretreatment blocked these effects. Basal TNF-α and IL-6 secretion were at the limits of delectability. Basal MCP-1 production was stimulated by pressure, which was blocked by ethanol. Even this low LPS dose stimulated microglial secretion of TNF-α, IL-6 and MCP-1. Pressure inhibited LPS-stimulated production of these proinflammatory cytokines, while ethanol pretreatment blocked LPS-stimulated cytokine production. The combination of pressure and ethanol further reduced TNF-α, IL-6 and MCP-1 secretion by LPS-stimulated microglial cells. Alcohol’s anti-inflammatory effects may contribute to the reduced TBI mortality that some have described in acutely intoxicated patients, while pressure downregulation of inflammatory cytokine release could create a negative feedback that ameliorates inflammation in TBI.
PMCID: PMC3837572  PMID: 23140827
Proinflammatory cytokines; microglial cells; MCP-1; IL-6; mechanotransduction
23.  DDAH1 Deficiency Attenuates Endothelial Cell Cycle Progression and Angiogenesis 
PLoS ONE  2013;8(11):e79444.
Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide (NO) synthase (NOS). ADMA is eliminated largely by the action of dimethylarginine dimethylaminohydrolase1 (DDAH1). Decreased DDAH activity is found in several pathological conditions and is associated with increased risk of vascular disease. Overexpression of DDAH1 has been shown to augment endothelial proliferation and angiogenesis. To better understand the mechanism by which DDAH1 influences endothelial proliferation, this study examined the effect of DDAH1 deficiency on cell cycle progression and the expression of some cell cycle master regulatory proteins. DDAH1 KO decreased in vivo Matrigel angiogenesis and depressed endothelial repair in a mouse model of carotid artery wire injury. DDAH1 deficiency decreased VEGF expression in HUVEC and increased NF1 expression in both HUVEC and DDAH1 KO mice. The expression of active Ras could overcome the decreased VEGF expression caused by the DDAH1 depletion. The addition of VEGF and knockdown NF1 could both restore proliferation in cells with DDAH1 depletion. Flow cytometry analysis revealed that DDAH1 sRNAi knockdown in HUVEC caused G1 and G2/M arrest that was associated with decreased expression of CDC2, CDC25C, cyclin D1 and cyclin E. MEF cells from DDAH1 KO mice also demonstrated G2/M arrest that was associated with decreased cyclin D1 expression and Akt activity. Our findings indicate that DDAH1 exerts effects on cyclin D1 and cyclin E expression through multiple mechanisms, including VEGF, the NO/cGMP/PKG pathway, the Ras/PI3K/Akt pathway, and NF1 expression. Loss of DDAH1 effects on these pathways results in impaired endothelial cell proliferation and decreased angiogenesis. The findings provide background information that may be useful in the development of therapeutic strategies to manipulate DDAH1 expression in cardiovascular diseases or tumor angiogenesis.
PMCID: PMC3832548  PMID: 24260221
24.  Exploring the Relationship Between Drug Side-Effects and Therapeutic Indications 
AMIA Annual Symposium Proceedings  2013;2013:1568-1577.
Therapeutic indications and drug side-effects are both measureable human behavioral or physiological changes in response to the treatment. In modern drug development, both inferring potential therapeutic indications and identifying clinically important drug side-effects are challenging tasks. Previous studies have utilized either chemical structures or protein targets to predict indications and side-effects. In this study, we compared indication prediction using side-effect information and side-effect prediction using indication information against models using only chemical structures and protein targets. Experimental results based on 10-fold cross-validation, show that drug side-effects and therapeutic indications are the most predictive features for each other. In addition, we extracted 6,706 statistically highly correlated disease-side-effect pairs from all known drug-disease and drug-side-effect relationships. Many relationship pairs provide explicit repositioning hypotheses (e.g., drugs causing postural hypotension are potential candidates for hypertension) and clear adverse-reaction watch lists (e.g., drugs for heart failure possibly cause impotence). All data sets and highly correlated disease-side-effect relationships are available at
PMCID: PMC3900166  PMID: 24551427
25.  DNA Pooling Base Genome-Wide Association Study Identifies Variants at NRXN3 Associated with Delayed Encephalopathy after Acute Carbon Monoxide Poisoning 
PLoS ONE  2013;8(11):e79159.
Delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) is more characteristic of anoxic encephalopathy than of other types of anoxia. Those who have the same poisoning degree and are of similar age and gender have a greater risk of getting DEACMP. This has made it clear that there are obvious personal differences. Genetic factors may play a very important role. The authors performed a genome-wide association study involving pooling of DNA obtained from 175 patients and 244 matched acute carbon monoxide poisoning without delayed encephalopathy controls. The Illumina HumanHap 660 Chip array was used for DNA pools. Allele frequencies of all SNPs were compared between delayed encephalopathy after acute carbon monoxide poisoning and control groups and ranked. A total of 123 SNPs gave an OR >1.4. Of these, 46 mapped in or close to known genes. Forty-eight SNPs located in 19 genes were associated with DEACMP after correction for 5% FDR in the genome-wide association of pooled DNA. Two SNPs (rs11845632 and rs2196447) locate in the Neurexin 3 gene were selected for individual genotyping in all samples and another cohort consisted of 234 and 271 controls. There were significant differences in the genotype and allele frequencies of rs11845632 and rs2196447 between the DEACMP group and controls group (all P-values <0.05). This study describes a positive association between Neurexin 3 and controls in the Han Chinese population, and provides genetic evidence to support the susceptibility of DEACMP, which may be the resulting interaction of environmental and genetic factors.
PMCID: PMC3827149  PMID: 24265751

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