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1.  Correlation of CCNA1 Promoter Methylation with Malignant Tumors: A Meta-Analysis Introduction 
BioMed Research International  2015;2015:134027.
Epigenetic silencing of tumor suppressor genes by promoter methylation plays vital roles in the process of carcinogenesis. The purpose of this meta-analysis was to determine whether the aberrant methylation of cyclin A1 (CCNA1) may be of great significance to human malignant tumors. By searching both English and Chinese language-based electronic databases carefully, we tabulated and analyzed parameters from each study. All human-associated case-control studies were included providing available data for CCNA1 methylation and reporting the adjusted odds ratios (ORs) and 95% confidence intervals (CI) conducted with the use of Version 12.0 STATA software. A total of 10 case-control studies (619 patients with cancers and 292 healthy controls) were included for the following statistical analysis. Pooled OR values from all articles revealed that the frequency of CCNA1 methylation in cancer tissues was significantly higher than those of normal tissues (P < 0.001). Further ethnicity indicated that the frequency of CCNA1 methylation was correlated with the development of malignant tumors among all those included experimental subgroups (all P < 0.05). These data from results indicated a significant connection of CCNA1 methylation with poor progression in human malignant tumors among both Caucasian and Asian populations.
PMCID: PMC4310450  PMID: 25654082
2.  Gemcitabine sensitivity factors, hENT1 and RRM1 as potential prognostic biomarker for advanced biliary tract cancer 
Background and aims: Biliary tract caner (BTC) is one of rare malignant disease with poor prognosis. Gemcitabine has been widely used as chemotherapeutic agent for advanced BTC treatment. Several molecules involved in gemcitabine metabolism, including human equilibrative nucleoside transporter (hENT1) and ribonucleotide reductase subunit M1 (RRM1), have been investigated as predictive biomarkers of chemotherapy efficacy. The aim of present study is to determine whether hENT1 and RRM1 could be used as the biomarkers to assess the efficacy of chemotherapy and predict survival in patients with advanced BTC. Methods: The analysis was performed on samples from 44 patients with unresectable or recurrent BTC who were treated with gemcitabine as first-line therapy. We determined levels of hENT1 and RRM1 with immunohistochemistry (IHC). Also, its prognostic and predictive role on tumor response and several clinical factors for survival were evaluated with Kaplan-Meier or Cox analysis. Results: The patients who were clinical benefit (partial response [PR] or stable disease [SD]) had high level of hENT1 (P = 0.046) and low level of RRM1 (P = 0.033). Moreover, hENT1 expression was a significant factor for progression free survival (PFS) (P = 0.005) and overall survival (OS) (P = 0.048) in Cox univariate analysis. Also, hENT1 was an independent prognostic factor of OS based on Cox multivariate analysis (P = 0.005). Conclusions: The expression of hENT1 and RRM1 was associated with gemcitabine efficacy. hENT1 was one of reliable predictive marker of survival in patients with advanced BTC patients.
PMCID: PMC4307450  PMID: 25664003
Biliary tract cancer; gemcitabine; human equilibrative nucleoside transporter 1; ribonucleotide reductase subunit M1
3.  Modeling the Dynamics and Migratory Pathways of Virus-Specific Antibody-Secreting Cell Populations in Primary Influenza Infection 
PLoS ONE  2014;9(8):e104781.
The B cell response to influenza infection of the respiratory tract contributes to viral clearance and establishes profound resistance to reinfection by related viruses. Numerous studies have measured virus-specific antibody-secreting cell (ASC) frequencies in different anatomical compartments after influenza infection and provided a general picture of the kinetics of ASC formation and dispersion. However, the dynamics of ASC populations are difficult to determine experimentally and have received little attention. Here, we applied mathematical modeling to investigate the dynamics of ASC growth, death, and migration over the 2-week period following primary influenza infection in mice. Experimental data for model fitting came from high frequency measurements of virus-specific IgM, IgG, and IgA ASCs in the mediastinal lymph node (MLN), spleen, and lung. Model construction was based on a set of assumptions about ASC gain and loss from the sampled sites, and also on the directionality of ASC trafficking pathways. Most notably, modeling results suggest that differences in ASC fate and trafficking patterns reflect the site of formation and the expressed antibody class. Essentially all early IgA ASCs in the MLN migrated to spleen or lung, whereas cell death was likely the major reason for IgM and IgG ASC loss from the MLN. In contrast, the spleen contributed most of the IgM and IgG ASCs that migrated to the lung, but essentially none of the IgA ASCs. This finding points to a critical role for regional lymph nodes such as the MLN in the rapid generation of IgA ASCs that seed the lung. Results for the MLN also suggest that ASC death is a significant early feature of the B cell response. Overall, our analysis is consistent with accepted concepts in many regards, but it also indicates novel features of the B cell response to influenza that warrant further investigation.
PMCID: PMC4149352  PMID: 25171166
4.  Down-regulation of miR-34a alleviates mesangial proliferation in vitro and glomerular hypertrophy in early diabetic nephropathy mice by targeting GAS1 
Diabetic nephropathy (DN) is a major diabetic complication characterized by mesangial proliferation and glomerular hypertrophy. MicroRNAs might play an important role in these pathological processes. The aim of this study is to examine the possible association of miR-34a as one of the microRNAs with DN and underlying mechanisms in vitro and in vivo.
According to previous results of microarray which compared the different microRNAs between diabetic and normal control mice, miR-34a was chosen and its expression was detected by qRT-PCR. Cell viability was then assessed using Cell Counting Kit-8 (CCK8) and 5-ethynyl-20-deoxyuridine (EDU) incorporation. Antagomir was injected in db/db mice to down regulate miR-34a. Average diameter of glomeruli was analyzed by periodic acid-Schiff (PAS) stain of kidney. Luciferase gene report assay was then performed to identify the target gene of miR-34a. Additional immunoblotting and immunohistochemical analyses were implemented to verify the expression level of growth arrest-specific 1 (GAS1).
MiR-34a expression level was increased under high glucose condition in vitro and in vivo. Down-regulation of miR-34a inhibits mice mesangial cells (MMCs) proliferation in vitro and alleviates glomerular hypertrophy in vivo. GAS1 was proved to be the target of miR-34a through luciferase report. Moreover, up-regulation of GAS1 expression was observed in the presence of miR-34a antagomir as compared withmiR-34a antagomir-NC in high-glucose-treated MMCs and db/db mice, respectively.
MiR-34a regulated mesangial proliferation and glomerular hypertrophy by directly inhibiting GAS1 in early DN.
PMCID: PMC4087162  PMID: 24560136
Diabetic nephropathy; Glomerular hypertrophy; miR-34a; GAS1
5.  Postsynaptic potentiation of corticospinal projecting neurons in the anterior cingulate cortex after nerve injury 
Molecular Pain  2014;10:33.
Long-term potentiation (LTP) is the key cellular mechanism for physiological learning and pathological chronic pain. In the anterior cingulate cortex (ACC), postsynaptic recruitment or modification of AMPA receptor (AMPAR) GluA1 contribute to the expression of LTP. Here we report that pyramidal cells in the deep layers of the ACC send direct descending projecting terminals to the dorsal horn of the spinal cord (lamina I-III). After peripheral nerve injury, these projection cells are activated, and postsynaptic excitatory responses of these descending projecting neurons were significantly enhanced. Newly recruited AMPARs contribute to the potentiated synaptic transmission of cingulate neurons. PKA-dependent phosphorylation of GluA1 is important, since enhanced synaptic transmission was abolished in GluA1 phosphorylation site serine-845 mutant mice. Our findings provide strong evidence that peripheral nerve injury induce long-term enhancement of cortical-spinal projecting cells in the ACC. Direct top-down projection system provides rapid and profound modulation of spinal sensory transmission, including painful information. Inhibiting cortical top-down descending facilitation may serve as a novel target for treating neuropathic pain.
PMCID: PMC4060852  PMID: 24890933
6.  Levels of PAH-DNA Adducts in Placental Tissue and the Risk of Fetal Neural Tube Defects in a Chinese Population 
We examined the relationship between PAH-DNA adduct levels in the placental tissue, measured by a highly sensitive 32P-postlabeling assay, and the risk of fetal neural tube defects (NTDs). We further explored the interaction between PAH-DNA adducts and placental PAHs with respect to NTD risk. Placental tissues from 80 NTD-affected pregnancies and 50 uncomplicated normal pregnancies were included in this case-control study. Levels of PAH-DNA adducts were lower in the NTD group (8.12 per 108 nucleotides) compared to controls (9.92 per 108 nucleotides). PAH-DNA adduct concentrations below the median was associated with a 3-fold increased NTD risk. Women with a low PAH-DNA adduct level in concert with a high placental PAH level resulted in a 10-fold elevated risk of having an NTD-complicated pregnancy. A low level of placental PAH-DNA adducts was associated with an increased risk of NTDs; this risk increased dramatically when a low adduct level was coupled with a high placental PAH concentration.
PMCID: PMC4040017  PMID: 23416326
Polycyclic aromatic hydrocarbons (PAHs); DNA adducts; Neural tube defects (NTDs); Placenta; Fetus
7.  Obesity Increases Cerebrocortical Reactive Oxygen Species And Impairs Brain Function 
Nearly two-thirds of the population in the United States is overweight or obese, and this unprecedented level of obesity will undoubtedly have a profound impact on overall health, although little is currently known about the effects of obesity on the brain. The objective of the current study was to investigate cerebral oxidative stress and cognitive decline in the context of diet-induced obesity (DIO). We demonstrate for the first time that DIO induces higher levels of reactive oxygen species (ROS) in the brain, and promotes cognitive impairment. Importantly, we also demonstrate for the first time in these studies that both body weight and adiposity are tightly correlated with the level of ROS. Interestingly, ROS were not correlated with cognitive decline in this model. Alterations in the antioxidant/detoxification Nrf2 pathway, superoxide dismutase, and catalase were not significantly altered in response to DIO. A significant impairment in glutathione peroxidase was observed in response to DIO. Taken together, these data demonstrate for the first time that DIO increases the level of total and individual ROS in the brain, and highlight a direct relationship between the amount of adiposity and the level of oxidative stress within the brain. These data have important implications for understanding the negative effects of obesity on the brain, and are vital to understanding the role of oxidative stress in mediating the effects of obesity on the brain.
PMCID: PMC4038352  PMID: 23116605
adipose; brain; cognitive impairment; free radicals; neurodegeneration; oxidative stress
8.  Role of Physiological Levels of 4-Hydroxynonenal on Adipocyte Biology: Implications for Obesity and Metabolic Syndrome 
Free radical research  2012;47(1):8-19.
Lipid peroxidation products such as 4-hydroxynonenal (HNE) are known to be increased in response to oxidative stress, and are known to cause dysfunction and pathology in a variety of tissues during periods of oxidative stress. The aim of the current study was to determine the chronic (repeated HNE exposure) and acute effects of physiological concentrations of HNE towards multiple aspects of adipocyte biology using differentiated 3T3-L1 adipocytes. Our studies demonstrate that acute and repeated exposure of adipocytes with physiological low concentrations of HNE is sufficient to promote subsequent oxidative stress, impaired adipogenesis, alter the expression of adipokines, and increase lipolytic gene expression and increase FFA release. These results provide an insight in to the role of HNE induced oxidative stress in regulation of adipocyte differentiation and adipose dysfunction. Taken together, these data indicate a potential role for HNE promoting diverse effects towards adipocyte homeostasis and adipocyte differentiation, which may be important to the pathogenesis observed in obesity and metabolic syndrome.
PMCID: PMC4038367  PMID: 23025469
adipose; adipogenesis; Insulin resistance; diabetes; metabolic syndrome; obesity; oxidative stress
9.  AIM2 Mediates Inflammation-Associated Renal Damage in Hepatitis B Virus-Associated Glomerulonephritis by Regulating Caspase-1, IL-1β, and IL-18 
Mediators of Inflammation  2014;2014:190860.
Background & Aims. AIM2 plays an important role in innate immunity, but its role in regulating the immune response to hepatitis B virus (HBV) is unknown. We hypothesized that AIM2 expression is positively correlated with HBV-mediated inflammation in patients with HBV-associated glomerulonephritis (HBV-GN), potentiating inflammation and leading to renal damage. We therefore analyzed the expression of AIM2 and inflammatory factors in HBV-GN tissues and cell lines relative to the inflammatory response to HBV infection and HBV status. Methods. Seventy-nine patients with chronic nephritis (CN) were included: 54 with HBV-GN and 24 with chronic glomerulonephritis (CGN). Expression of AIM2, caspase-1, and IL-1β was detected by immunohistochemistry in renal biopsies from each patient. Following siRNA-mediated knockdown of AIM2 in HBV-infected and HBV-uninfected human glomerular mesangial (HGM) cells, expression of caspase-1, IL-1β, and IL-18 was detected by qRT-PCR and Western blot. Results. AIM2 expression in HBV-GN biopsies (81.4%) was significantly higher than in CGN (4.0%) and positively correlated with caspase-1 and IL-1β expression in HBV-GN. In vitro, AIM2 knockdown reduced caspase-1, IL-1β, and IL-18 expression in HBV-infected and HBV-uninfected HGM cells. Conclusion. AIM2 elevation during HBV infection or replication may contribute to inflammatory damage, thus providing a putative therapeutic target for HBV-GN.
PMCID: PMC3950499  PMID: 24701032
10.  A PSO-Based Hybrid Metaheuristic for Permutation Flowshop Scheduling Problems 
The Scientific World Journal  2014;2014:902950.
This paper investigates the permutation flowshop scheduling problem (PFSP) with the objectives of minimizing the makespan and the total flowtime and proposes a hybrid metaheuristic based on the particle swarm optimization (PSO). To enhance the exploration ability of the hybrid metaheuristic, a simulated annealing hybrid with a stochastic variable neighborhood search is incorporated. To improve the search diversification of the hybrid metaheuristic, a solution replacement strategy based on the pathrelinking is presented to replace the particles that have been trapped in local optimum. Computational results on benchmark instances show that the proposed PSO-based hybrid metaheuristic is competitive with other powerful metaheuristics in the literature.
PMCID: PMC3928865  PMID: 24672389
11.  Targeting the Biophysical Properties of the Myeloma Initiating Cell Niches: A Pharmaceutical Synergism Analysis Using Multi-Scale Agent-Based Modeling 
PLoS ONE  2014;9(1):e85059.
Multiple myeloma, the second most common hematological cancer, is currently incurable due to refractory disease relapse and development of multiple drug resistance. We and others recently established the biophysical model that myeloma initiating (stem) cells (MICs) trigger the stiffening of their niches via SDF-1/CXCR4 paracrine; The stiffened niches then promote the colonogenesis of MICs and protect them from drug treatment. In this work we examined in silico the pharmaceutical potential of targeting MIC niche stiffness to facilitate cytotoxic chemotherapies. We first established a multi-scale agent-based model using the Markov Chain Monte Carlo approach to recapitulate the niche stiffness centric, pro-oncogenetic positive feedback loop between MICs and myeloma-associated bone marrow stromal cells (MBMSCs), and investigated the effects of such intercellular chemo-physical communications on myeloma development. Then we used AMD3100 (to interrupt the interactions between MICs and their stroma) and Bortezomib (a recently developed novel therapeutic agent) as representative drugs to examine if the biophysical properties of myeloma niches are drugable. Results showed that our model recaptured the key experimental observation that the MBMSCs were more sensitive to SDF-1 secreted by MICs, and provided stiffer niches for these initiating cells and promoted their proliferation and drug resistance. Drug synergism analysis suggested that AMD3100 treatment undermined the capability of MICs to modulate the bone marrow microenvironment, and thus re-sensitized myeloma to Bortezomib treatments. This work is also the first attempt to virtually visualize in 3D the dynamics of the bone marrow stiffness during myeloma development. In summary, we established a multi-scale model to facilitate the translation of the niche-stiffness centric myeloma model as well as experimental observations to possible clinical applications. We concluded that targeting the biophysical properties of stem cell niches is of high clinical potential since it may re-sensitize tumor initiating cells to chemotherapies and reduce risks of cancer relapse.
PMCID: PMC3903473  PMID: 24475036
12.  Prognostic factors associated with solitary plasmacytoma 
OncoTargets and therapy  2013;6:1659-1666.
Solitary plasmacytoma (SP) is a rare tumor with low incidence. The aim of this study was to investigate the clinical features, treatment strategies, and relative prognostic factors of 66 patients with SP. These patients made up 10.25% of the 644 patients with plasma cell dyscrasias treated at the Tianjin Medical University Cancer Institute and Hospital over the past 12 years. SP always presented with either solitary bone plasmacytoma (SBP) or extramedullary plasmacytoma (EMP), as determined by the location of the lesions. SBP occurred most frequently in the vertebral column and EMP in the upper respiratory tract. In addition to other factors, tumor size, serum M protein level, urinary Bence Jones protein level, and disease progression toward multiple myeloma were significantly different between the two groups (P<0.05). Larger tumor size (≥5 cm) was associated with poor prognosis of local control, multiple myeloma–free survival, overall survival and progression-free survival for SBP patients. Radiotherapy and serum β2 microglobulin <3.5 mg/L were favorable prognostic factors for local control, multiple myeloma-free survival, and progression-free survival in patients with EMP.
PMCID: PMC3833869  PMID: 24259986
solitary bone plasmacytoma; extramedullary plasmacytoma; clinical characteristics; prognosis; radiotherapy
13.  Cytokine Combination Therapy Prediction for Bone Remodeling in Tissue Engineering Based on the Intracellular Signaling Pathway 
Biomaterials  2012;33(33):8265-8276.
The long-term performance of tissue-engineered bone grafts is determined by a dynamic balance between bone regeneration and resorption. We proposed using embedded cytokine slow-releasing hydrogels to tune this balance toward a desirable final bone density. In this study we established a systems biology model, and quantitatively explored the combinatorial effects of delivered cytokines from hydrogels on final bone density. We hypothesized that: 1) bone regeneration was driven by transcription factors Runx2 and Osterix, which responded to released cytokines, such as Wnt, BMP2, and TGFβ, drove the development of osteoblast lineage, and contributed to bone mass generation; and 2) the osteoclast lineage, on the other hand, governed the bone resorption, and communications between these two lineages determined the dynamics of bone remodeling. In our model, Intracellular signaling pathways were represented by ordinary differential equations, while the intercellular communications and cellular population dynamics were modeled by stochastic differential equations. Effects of synergistic cytokine combinations were evaluated by Loewe index and Bliss index. Simulation results revealed that the Wnt/BMP2 combinations released from hydrogels showed best control of bone regeneration and synergistic effects, and suggested optimal dose ratios of given cytokine combinations released from hydrogels to most efficiently control the long-term bone remodeling. We revealed the characteristics of cytokine combinations of Wnt/BMP2 which could be used to guide the design of in vivo bone scaffolds and the clinical treatment of some diseases such as osteoporosis.
PMCID: PMC3444627  PMID: 22910219
Bone tissue engineering; Bone remodeling; Cytokine combination therapy; Systems biology; Osteogenic differentiation; Signaling pathway
14.  Hypoxia Promotes Epithelial - Mesenchymal Transition of Hepatocellular Carcinoma Cells via Inducing GLIPR-2 Expression 
PLoS ONE  2013;8(10):e77497.
Glioma pathogenesis related-2 (GLIPR-2) belongs to pathogenesis related-1 (PR-1) family whose function remains unknown. In our previous studies, GLIPR-2 was found to be a novel potent stimulator of epithelial-to-mesenchymal transition (EMT) in renal fibrosis which has been classified as type 2 EMT. However, whether GLIPR-2 could induce type 3 EMT in carcinogenesis needs further investigation. In this study, we showed that GLIPR-2 was expressed in hepatocellular carcinoma (HCC) tissues, hypoxia could upregulate the expression of GLIPR-2 in HepG2 and PLC/PRF/5 cells in vitro, overexpression of this protein promoted migration and invasion via EMT, knockdown of GLIPR-2 attenuated migration and invasion of HepG2 and PLC/PRF/5 cells in hypoxia. Moreover, extracellular signal-regulated kinases 1 and 2 (ERK1/2) are positively regulated by GLIPR-2. Taken together, we provide evidence for a hypoxia/GLIPR-2/EMT/migration and invasion axis in HCC cells and it provides novel insights into the mechanism of migration and invasion of hepatocellular carcinoma cells in hypoxia condition.
PMCID: PMC3812270  PMID: 24204846
15.  Programmable folding of fusion RNA in vivo and in vitro driven by pRNA 3WJ motif of phi29 DNA packaging motor 
Nucleic Acids Research  2013;42(2):e10.
Misfolding and associated loss of function are common problems in constructing fusion RNA complexes due to changes in energy landscape and the nearest-neighbor principle. Here we report the incorporation and application of the pRNA-3WJ motif of the phi29 DNA packaging motor into fusion RNA with controllable and predictable folding. The motif included three discontinuous ∼18 nucleotide (nt) fragments, displayed a distinct low folding energy (Shu D et al., Nature Nanotechnology, 2011, 6:658–667), and folded spontaneously into a leading core that enabled the correct folding of other functionalities fused to the RNA complex. Three individual fragments dispersed at any location within the sequence allowed the other RNA functional modules to fold into their original structures with authentic functions, as tested by Hepatitis B virus ribozyme, siRNA, and aptamers for malachite green (MG), spinach, and streptavidin (STV). Only nine complementary nucleotides were present for any two of the three ∼18-nt fragments, but the three 9 bp branches were so powerful that they disrupted other double strands with more than 15 bp within the fusion RNA. This system enabled the production of fusion complexes harboring multiple RNA functionalities with correct folding for potential applications in biotechnology, nanomedicine and nanotechnology. We also applied this system to investigate the principles governing the folding of RNA in vivo and in vitro. Temporal production of RNA sequences during in vivo transcription caused RNA to fold into different conformations that could not be predicted with routine principles derived from in vitro studies.
PMCID: PMC3902900  PMID: 24084081
16.  In Vivo Noninvasive Detection of Brown Adipose Tissue through Intermolecular Zero-Quantum MRI 
PLoS ONE  2013;8(9):e74206.
The recent discovery of active Brown Adipose Tissue (BAT) in adult humans has opened new avenues for obesity research and treatment, as reduced BAT activity seem to be implicated in human energy imbalance, diabetes, and hypertension. However, clinical applications are currently limited by the lack of non-invasive tools for measuring mass and function of this tissue in humans. Here we present a new magnetic resonance imaging method based on the normally invisible intermolecular multiple-quantum coherence 1H MR signal. This method, which doesn’t require special hardware modifications, can be used to overcome partial volume effect, the major limitation of MR-based approaches that are currently being investigated for the detection of BAT in humans. With this method we can exploit the characteristic cellular structure of BAT to selectively image it, even when (as in humans) it is intimately mixed with other tissues. We demonstrate and validate this method in mice using PET scans and histology. We compare this methodology with conventional 1H MR fat fraction methods. Finally, we investigate its feasibility for the detection of BAT in humans.
PMCID: PMC3769256  PMID: 24040203
17.  NRAMP1, VDR, HLA-DRB1, and HLA-DQB1 Gene Polymorphisms in Susceptibility to Tuberculosis among the Chinese Kazakh Population: A Case-Control Study 
BioMed Research International  2013;2013:484535.
Background. To explore the potential role of natural-resistance-associated macrophage protein 1 (NRAMP1) gene, vitamin D receptor (VDR) gene, (human leukocyte antigen, (HLA-DRB1) HLA) -DRB1 gene, and HLA-DQB1 gene polymorphisms in susceptibility to tuberculosis (TB) in the Chinese Kazakh population. Methods. A case-control study was performed on the Chinese Kazak population. Genetic polymorphisms of NRAMP1 gene (3′UTR) and VDR gene (TaqI and FokI) were analysed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and sequencing analysis in TB patients and healthy controls. Genetic polymorphisms of HLA-DRB1 gene and HLA-DQB1 gene in the two groups were detected with polymerase chain reaction-sequence-specific primers (PCR-SSPs) technique and sequencing analysis. Results. There was statistically significant difference in the 3′UTR polymorphism between the TB patients and healthy controls in the Chinese Kazak population (P = 0.002; OR = 1.859; 95% CI = 1.182–2.926). Significant difference was observed in the FokI polymorphism between the TB patients and healthy controls (P = 0.001; OR = 1.530; 95% CI = 1.007–2.325). It does not disclose any significant association between the disease and TaqI (P > 0.05). Alleles HLA-DRB1∗04 and HLA-DQB1∗0201 occurred more frequently in patients than in controls (P = 0.011 and 0.002; OR = 1.889 and 1.802; 95% CI = 1.153–3.095 and 1.230–2.639, resp.). Conclusions. Polymorphisms in the NRAMP1 gene, VDR gene, HLA-DRB1 gene, and HLA-DQB1 gene are statistically associated with susceptibility to TB in the Chinese Kazakh population.
PMCID: PMC3758880  PMID: 24024195
18.  Molecular footprints of domestication and improvement in soybean revealed by whole genome re-sequencing 
BMC Genomics  2013;14:579.
Artificial selection played an important role in the origin of modern Glycine max cultivars from the wild soybean Glycine soja. To elucidate the consequences of artificial selection accompanying the domestication and modern improvement of soybean, 25 new and 30 published whole-genome re-sequencing accessions, which represent wild, domesticated landrace, and Chinese elite soybean populations were analyzed.
A total of 5,102,244 single nucleotide polymorphisms (SNPs) and 707,969 insertion/deletions were identified. Among the SNPs detected, 25.5% were not described previously. We found that artificial selection during domestication led to more pronounced reduction in the genetic diversity of soybean than the switch from landraces to elite cultivars. Only a small proportion (2.99%) of the whole genomic regions appear to be affected by artificial selection for preferred agricultural traits. The selection regions were not distributed randomly or uniformly throughout the genome. Instead, clusters of selection hotspots in certain genomic regions were observed. Moreover, a set of candidate genes (4.38% of the total annotated genes) significantly affected by selection underlying soybean domestication and genetic improvement were identified.
Given the uniqueness of the soybean germplasm sequenced, this study drew a clear picture of human-mediated evolution of the soybean genomes. The genomic resources and information provided by this study would also facilitate the discovery of genes/loci underlying agronomically important traits.
PMCID: PMC3844514  PMID: 23984715
Artificial selection; Evolution; Genetic diversity; Population genomics; Soybean
20.  Novel ATPase Cu2+ Transporting Beta Polypeptide Mutations in Chinese Families with Wilson's Disease 
PLoS ONE  2013;8(7):e66526.
Wilson's disease (WD) is an autosomal recessive inherited disorder caused by mutations in the ATPase Cu2+ transporting beta polypeptide gene (ATP7B). The detailed metabolism of copper-induced pathology in WD is still unknown. Gene mutations as well as the possible pathways involved in the ATP7B deficiency were documented. The ATP7B gene was analyzed for mutations in 18 Chinese Han families with WD by direct sequencing. Cell viability and apoptosis analysis of ATP7B small interfering RNA (siRNA)-treated human liver carcinoma (HepG2) cells were measured by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay and Hoechst 33342 staining. Finally, the expression of B-cell CLL/lymphoma 2 (BCL2), BCL2-associated X protein (BAX), sterol regulatory element binding protein 1 (SREBP1), and minichromosome maintenance protein 7 (MCM7) of ATP7B siRNA-treated cells were tested by real-time polymerase chain reaction (real-time PCR) and Western blot analysis. Twenty different mutations including four novel mutations (p.Val145Phe, p.Glu388X, p.Thr498Ser and p.Gly837X) in the ATP7B gene were identified in our families. Haplotype analysis revealed that founder effects for four mutations (p.Arg778Leu, p.Pro992Leu, p.Ile1148Thr and p.Ala1295Val) existed in these families. Transfection of HepG2 cells with ATP7B siRNA resulted in decreased mRNA expression by 86.3%, 93.1% and 90.8%, and decreased protein levels by 58.5%, 85.5% and 82.1% at 24, 48 and 72 hours, respectively (All P<0.01). In vitro study revealed that the apoptotic, cell cycle and lipid metabolism pathway may be involved in the mechanism of WD. Our results revealed that the genetic cause of 18 Chinese families with WD and ATP7B deficiency-induce apoptosis may result from imbalance in cell cycle and lipid metabolism pathway.
PMCID: PMC3699604  PMID: 23843956
21.  The SSRI Citalopram Affects Fetal Thalamic Axon Responsiveness to Netrin-1 In vitro Independently of SERT Antagonism 
Neuropsychopharmacology  2012;37(8):1879-1884.
Serotonin (5-hydroxytryptamine, 5-HT) signaling is thought to modulate nervous system development. Genetic and pharmacological studies support the idea that altered 5-HT signaling during development can have enduring consequences on brain function and behavior. Recently, we discovered that 5-HT can modulate thalamic axon guidance in vitro and in vivo. Embryonic thalamic axons transiently express the 5-HT transporter (SERT; Slc6a4) and accumulate 5-HT, suggesting that the SERT activity of these axons may regulate 5-HT-modulated guidance cues. We tested whether pharmacologically blocking SERT using selective 5-HT reuptake inhibitors (SSRIs) would impact the action of 5-HT on thalamic axon responses to netrin-1 in vitro. Surprisingly, we observed that two high-affinity SSRIs, racemic citalopram ((RS)-CIT) and paroxetine, affect the outgrowth of embryonic thalamic axons, but differ with respect to their dependence on SERT blockade. Using a recently developed ‘citalopram insensitive' transgenic mouse line and in vitro pharmacology, we show that the effect of (RS)-CIT effect is SERT independent, but rather arises from R-CIT activation of the orphan sigma-1 receptor(σ1, Oprs1). Our results reveal a novel σ1 activity in modulating axon guidance and a 5-HT independent action of a widely prescribed SSRI. By extension, (RS)-CIT and possibly other structurally similar SSRIs may have other off-target actions that can impact neural development and contribute to therapeutic efficacy or side effects.
PMCID: PMC3376320  PMID: 22414815
serotonin; antidepressants; citalopram; SSRI; brain development; sigma-1 receptor; antidepressants; development/developmental disorders; fetal programming; molecular & cellular neurobiology; serotonin; transporters
22.  Multi-scale agent-based modeling on melanoma and its related angiogenesis analysis 
Recently, melanoma has become the most malignant and commonly occurring skin cancer. Melanoma is not only the major source (75%) of deaths related to skin cancer, but also it is hard to be treated by the conventional drugs. Recent research indicated that angiogenesis is an important factor for tumor initiation, expansion, and response to therapy. Thus, we proposed a novel multi-scale agent-based computational model that integrates the angiogenesis into tumor growth to study the response of melanoma cancer under combined drug treatment.
Our multi-scale agent-based model can simulate the melanoma tumor growth with angiogenesis under combined drug treatment. The significant synergistic effects between drug Dox and drug Sunitinib demonstrated the clinical potential to interrupt the communication between melanoma cells and its related vasculatures. Also, the sensitivity analysis of the model revealed that diffusivity related to the micro-vasculatures around tumor tissues closely correlated with the spread, oscillation and destruction of the tumor.
Simulation results showed that the 3D model can represent key features of melanoma growth, angiogenesis, and its related micro-environment. The model can help cancer researchers understand the melanoma developmental mechanism. Drug synergism analysis suggested that interrupting the communications between melanoma cells and the related vasculatures can significantly increase the drug efficacy against tumor cells.
PMCID: PMC3694033  PMID: 23800293
Microenvironment; Drug synergism; Agent-based model; Multi-scale; Melanoma; Anti-angiogenesis
23.  Heat stress-induced response of the proteomes of leaves from Salvia splendens Vista and King 
Proteome Science  2013;11:25.
Salvia splendens Ker-Gawl, most commonly used in China to add a splash of brilliant color to the surroundings during the warm season, is subject to heat stress, which can greatly affect its growth and yield.
To gain a comprehensive understanding of heat-tolerance mechanisms of S. splendens, we assessed the heat-stress responses and characterized the proteomes of leaves from two varieties, Vista (heat resistant) and King (heat sensitive). Denaturing two-dimensional gel electrophoresis (2–DE) and tandem mass spectrometry were used to identify heat-responsive proteins. Heat stress induced the reversible inactivation of photosystem II reaction centers and increased the amounts of antioxidative enzymes, thereby decreasing oxidative damage. Vista leaves had a much greater ability than King leaves to develop light-protective and oxygen-scavenging systems in response to heat stress. More than 1213 leaf proteome spots were reproducibly detected in the gels, with a total of 33 proteins in each leaf type differentially regulated when Salvia splendens were heat stress treated. Of these proteins, 23 and 28 from Vista and King, respectively, were identified.
Most of the identified proteins are involved in photosynthesis, metabolism, protein processing, or stress response, indicating that many different processes work together to establish a new cellular homeostasis in response to heat stress.
PMCID: PMC3720558  PMID: 23773552
24.  Effects of Fluid Shear Stress on Expression of Smac/DIABLO in Human Umbilical Vein Endothelial Cells☆ 
To investigate the molecular mechanisms of laminar shear stress on inhibition of apoptosis in endothelial cells, human umbilical vein endothelial cells (HUVECs) were starved in medium containing 2% fetal bovine serum and 20 dyne/cm2 shear stress.
HUVECs were subjected to shear stress or incubated in a static condition and then Smac/DIABLO expression was quantified by reverse-transcription polymerase chain reaction, real-time PCR, and western blot. The effect of shear stress on the migration of Smac/DIABLO proteins was detected by immunofluorescence microscopy.
Results demonstrated that 20 dyne/cm2 shear stress inhibited the expression of Smac/DIABLO at both the mRNA and protein levels in cultured HUVECs. Furthermore, release of Smac/DIABLO from mitochondria was induced by removal of basic fibroblast growth factor and decrease of fetal bovine serum in the medium, whereas shear stress inhibited its release under the same conditions.
These results suggest that down-regulation of Smac/DIABLO may contribute to the potent antiatherosclerotic effect of shear stress by preventing endothelial cells from entering apoptosis.
PMCID: PMC3862198  PMID: 24384678
apoptosis; atherosclerosis; human umbilical vein endothelial cells; shear stress; Smac/DIABLO
25.  Access to Healthcare and Medical Expenditure for the Middle-Aged and Elderly: Observations from China 
PLoS ONE  2013;8(5):e64589.
In the evaluation of a healthcare system, it is of interest to identify factors associated with the usage of different healthcare facilities and with different levels of medical expenditure.
A survey was conducted in January and February of 2012 in China. It focused on the middle-aged and elderly with age of 45 and above. A total of 2,093 people from 1,152 households were surveyed.
For inpatient treatment, the probability of using grade III hospitals, which had the highest level of care, was positively associated with age, being married, living in urban areas, and having higher income. For outpatient treatment, the probability of using grade III hospitals was positively associated with age, being married, working in enterprises, living in urban areas, living in central and western regions, and having higher income, and negatively associated with being farmers. The total and out-of-pocket (OOP) medical expenses were analyzed separately. It was found that the expense level was associated with age, education, occupation, living in urban areas, type of hospital used, insurance being used, and per capita income.
The access to healthcare and level of medical expenditure were found as associated with demographic characteristics. In addition, differences between areas and regions were observed. Such results may be useful for identifying vulnerable population and for tuning future healthcare development policies.
PMCID: PMC3654965  PMID: 23691252

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