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1.  Broad Suppression of NADPH Oxidase Activity Exacerbates Ischemia/Reperfusion Injury Through Inadvertent Downregulation of HIF-1α and Upregulation of PPARα 
Circulation research  2013;112(8):10.1161/CIRCRESAHA.111.300171.
Nox2 and Nox4 are major components of the NADPH oxidase (Nox) family, which purposefully produce reactive oxidative species (ROS), namely O2− and H2O2, in the heart. The isoform-specific contribution of Nox2 and Nox4 to ischemia/reperfusion (I/R) injury is poorly understood.
We investigated the role of Nox2 and Nox4 in mediating oxidative stress and myocardial injury during I/R using loss of function mouse models.
Methods and Results
Systemic (s) Nox2 KO, sNox4 KO, and cardiac-specific (c) Nox4 KO mice were subjected to I (30 min)/R (24 h). Both myocardial infarct size/area at risk (MI/AAR) and O2− production were lower in sNox2 KO, sNox4 KO, and cNox4 KO than in wild-type (WT) mice. Unexpectedly, however, the MI/AAR was greater, despite less O2− production, in sNox2 KO+cNox4 KO (DKO) mice and transgenic mice with cardiac-specific expression of dominant-negative Nox (Tg-DN-Nox), which suppresses both Nox2 and Nox4, than in WT or single KO mice. Hypoxia-inducible factor-1α (HIF-1α) was downregulated while peroxisome proliferator-activated receptor-alpha (PPARα) was upregulated in Tg-DN-Nox mice. A cross with mice deficient in prolyl hydroxylase 2, which hydroxylates HIF-1α, rescued the I/R injury and prevented upregulation of PPARα in Tg-DN-Nox mice. A cross with PPARα KO mice also attenuated the injury in Tg-DN-Nox mice.
nBoth Nox2 and Nox4 contribute to the increase in ROS and injury by I/R. However, low levels of ROS produced by either Nox2 or Nox4 regulate HIF-1α and PPARα, thereby protecting the heart against I/R, suggesting that Noxs also act as a physiological sensor for myocardial adaptation.
PMCID: PMC3871171  PMID: 23476056
Reactive oxygen species; oxidative stress; free radicals; ischemia/reperfusion
2.  Primary Prevention of Macroangiopathy in Patients With Short-Duration Type 2 Diabetes by Intensified Multifactorial Intervention 
Diabetes Care  2013;36(4):978-984.
To explore whether intensified, multifactorial intervention could prevent macrovascular disease in patients with recently diagnosed type 2 diabetes.
A total of 150 type 2 diabetic patients, with disease duration of <1 year and without clinical arteriosclerotic disease or subclinical atherosclerotic signs confirmed by ultrasonographic scanning of three conducting arteries, were randomized into an intensive intervention group and a conventional intervention group. They then received intensive, multifactorial intervention or conventional intervention over 7 years of follow-up. The patients’ common carotid intima-media thicknesses (CC-IMTs) were measured every year. The primary outcome was the time to the first occurrence of CC-IMTs ≥1.0 mm and/or development of atherosclerosis plaques in the carotid artery. The secondary outcome was clinical evidence of cardiovascular disease.
A total of 70 patients in the intensive group and 68 patients in the conventional group completed the 7-year follow-up. Subclinical macrovascular (primary) outcomes occurred in seven cases in the intensive group and 22 cases in the conventional group for a cumulative prevalence of 10.00 and 32.35%, respectively (P < 0.05). No significant differences between the two groups were observed regarding the secondary outcome.
Primary prevention of macrovascular diseases can be achieved through intensified, multifactorial intervention in patients with short-duration type 2 diabetes. Type 2 diabetic patients should undergo intensive multifactorial interventions with individual targets for the prevention of macrovascular diseases.
PMCID: PMC3609518  PMID: 23230099
3.  Loss of expression of N-acetylglucosaminyltransferase Va results in altered gene expression of glycosyltransferases and galectins 
FEBS letters  2008;582(4):527-535.
We isolated mouse embryo fibroblasts (MEFs) from N-acetylglucosaminyltransferase Va (GnT-Va) knockout mice and studied the effects of loss of expression of GnT-Va on asparagine- linked glycans (N-glycan) synthesis and the gene expression of groups of glycosyltransferases and galectins. Loss of GnT-Va expression caused aberrant expression of several N-glycan structures, including N-linked β(1,6) branching, poly-N-lactosamine, bisecting N-acetylglucosamine (GlcNAc) and sialic acid. Using quantitative reverse transcriptase-PCR (qRT-PCR), altered gene expression of several groups of glycosyltransferases and galectins was observed in GnT-Va null MEFs, supporting the observed changes in N-glycan structures. These results suggest that genetic disruption of GnT-Va ultimately resulted in altered MEFs gene expression and decreased tumor progression associated with loss of GnT-Va observed may result in part from a combination of effects from these altered gene expressions.
PMCID: PMC3971636  PMID: 18230362
Mouse embryo fibroblasts (MEFs); GnT-Va (Mgat5); Knockout; Glycosyltransferase; Galectin; qRT-PCR
4.  L-Serine Treatment May Improve Neurorestoration of Rats after Permanent Focal Cerebral Ischemia Potentially Through Improvement of Neurorepair 
PLoS ONE  2014;9(3):e93405.
The present study was conducted to clarify whether treatment with L-serine can improve the brain repair and neurorestoration of rats after permanent middle cerebral artery occlusion (pMCAO). After pMCAO, the neurological functions, brain lesion volume, and cortical injury were determined. GDNF, NGF, NCAM L1, tenascin-C, and Nogo-A levels were measured. Proliferation and differentiation of the neural stem cells (NSCs) and proliferation of the microvessels in the ischemic boundary zone of the cortex were evaluated. Treatment with L-serine (168 mg/kg body weight, i.p.) began 3 h after pMCAO and was repeated every 12 h for 7 days or until the end of the experiment. L-Serine treatment: 1) reduced the lesion volume and neuronal loss; 2) improved the recovery of neurological functions; 3) elevated the expression of nerve growth-related factors; and 4) facilitated the proliferation of endogenous NSCs and microvessels activated after pMCAO and increased the number of new-born neurons. 5) D-cycloserine, an inhibitor of serine hydroxymethyltransferase, blunted the effects of L-serine on NSC proliferation, differentiation, microvascular proliferation. In conclusions, L-serine treatment in pMCAO rats can reduce brain injury and facilitate neurorestoration which is partly associated with the improvement of proliferation of NSCs and microvessels, reconstruction of neurovascular units and resultant neurorepair. The effects of L-serine on endogenous NSC proliferation and microvascular proliferation are partly mediated by the action of L-serine as a substrate for the production of one-carbon groups used for purine and pyrimidine synthesis and modulation of the expression of some nerve growth-related factors.
PMCID: PMC3966884  PMID: 24671106
5.  Orthotopic liver transplantation in situs inversus adult from an ABO-incompatible donor with situs inversus 
BMC Gastroenterology  2014;14:46.
Situs inversus is a rare congenital anomaly characterized by the complete inversion of thoracic and abdominal organs. Liver transplantation in such patients or from donors in situs inversus is technically challenging because of the reversed anatomic structures. A small number of successful liver transplantation cases concerning situs inverus in either recipients or donors have been recently reported with different graft position and orientation. Here we reported an extremely rare case of liver retransplantation from an ABO incompatible situs inversus donor to an adult situs inversus recipient.
Case presentation
A 53-year-old complete situs inversus man developed graft failure due to severe biliary complication after his first liver transplantation from a situs solitus donor. Re-transplantation was performed using a graft liver from a likewise situs inversus donor. Although the blood type between donor and recipient was incompatible, the post-operative outcome was excellent under proper prophylaxis to the antibody-mediated rejection.
To the best of our knowledge, this is the first report of liver transplantation from situs inversus to situs inversus in adult recipient. Liver transplantation using situs matching donor makes the procedure much easier at the surgical point of view, which has a benefit of less potential surgical complications. Furthermore, ABO-incompatibility is acceptable for donor allocation in cases that both donor and recipient are situs inversus.
PMCID: PMC3975226  PMID: 24625305
Liver transplantation; Retransplantation; Situs inversus; Abo incompatible
6.  Exogenous norepinephrine attenuates the efficacy of sunitinib in a mouse cancer model 
Sunitinib alone exhibits satisfactory efficacy in several mouse homografts and xenografts but unsatisfactory efficacy in many kinds of solid tumors in clinic. Different from animals, receiving a diagnosis of cancer impacts chronic stress on patients. Here, we examine whether norepinephrine (NE), one of the most potent stress related hormones, leads to the difference in the efficacy of sunitinib between clinical and preclinical trials.
The influence of NE on mouse melanoma B16F1 cells under sunitinib was evaluated in vitro and in vivo. The β-AR/cAMP/PKA (β-adrenoceptor/cyclic adenosine monophosphate/protein kinase A) signaling pathway was also evaluated in human lung adenocarcinoma cells.
We found that NE upregulated the expression of VEGF, IL-8 and IL-6 in vitro and stimulated tumor growth in vivo, which was mediated by β-AR/cAMP/PKA signaling pathway and could be inhibited by propranolol, a β-blocker for hypertension for decades.
This research indicates exogenous norepinephrine attenuates the efficacy of sunitinib, and a combination of sunitinib and propranolol might be suggested as a new strategy in solid tumor in clinic.
PMCID: PMC3940302  PMID: 24555849
Tumor; Chronic stress; Norepinephrine; Sunitinib; Propranolol
7.  Thiol/Redox Metabolomic Profiling Implicates GSH Dysregulation in Early Experimental Graft versus Host Disease (GVHD) 
PLoS ONE  2014;9(2):e88868.
Graft-versus-host disease (GVHD) is a common complication of allogeneic bone marrow transplantation (BMT). Upregulation of inflammatory cytokines precedes the clinical presentation of GVHD and predicts its severity. In this report, thiol/redox metabolomics was used to identify metabolic perturbations associated with early preclinical (Day+4) and clinical (Day+10) stages of GVHD by comparing effects in Syngeneic (Syn; major histocompatibility complex- identical) and allogeneic transplant recipients (Allo BMT) in experimental models. While most metabolic changes were similar in both groups, plasma glutathione (GSH) was significantly decreased, and GSH disulfide (GSSG) was increased after allogeneic compared to syngeneic recipient and non-transplant controls. The early oxidation of the plasma GSH/GSSG redox couple was also observed irrespective of radiation conditioning treatment and was accompanied by significant rise in hepatic protein oxidative damage and ROS generation. Despite a significant rise in oxidative stress, compensatory increase in hepatic GSH synthesis was absent following Allo BMT. Early shifts in hepatic oxidative stress and plasma GSH loss preceded a statistically significant rise in TNF-α. To identify metabolomic biomarkers of hepatic GVHD injury, plasma metabolite concentrations analyzed at Day+10 were correlated with hepatic organ injury. GSSG (oxidized GSH) and β-alanine, were positively correlated, and plasma GSH cysteinylglycine, and branched chain amino acids were inversely correlated with hepatic injury. Although changes in plasma concentrations of cysteine, cystathionine (GSH precursors) and cysteinylglycine (a GSH catabolite) were not significant by univariate analysis, principal component analysis (PCA) indicated that accumulation of these metabolites after Allo BMT contributed significantly to early GVHD in contrast to Syn BMT. In conclusion, thiol/redox metabolomic profiling implicates that early dysregulation of host hepatic GSH metabolism and oxidative stress in sub-clinical GVHD before elevated TNF-α levels is associated with GVHD pathogenesis. Future studies will probe the mechanisms for these changes and examine the potential of antioxidant intervention strategies to modulate GVHD.
PMCID: PMC3928313  PMID: 24558439
8.  Seroprevalence of Toxoplasma gondii Infection in Sows in Hunan Province, China 
The Scientific World Journal  2014;2014:347908.
Toxoplasma gondii infections are prevalent in animals and humans worldwide. Although the prevalence of T. gondii has been reported in many animals in China, little is known of T. gondii infection in sows. Antibodies to T. gondii in sows in Hunan province, subtropical China, were examined using indirect hemagglutination test (IHAT). Overall, 31.3% (373/1191) of the examined sows were seropositive for T. gondii. Among 11 representative regions of Hunan province, the seroprevalence ranged from 14.8% to 45.1%. In addition, the T. gondii seroprevalence was higher in summer (37.4%) and autumn (34.9%) than in spring (24.6%) and winter (23.9%). Regarding different antibody titers, the seroprevalence ranged from 1.8% (titer ≥ 1 : 1024) to 17.4% (titer = 1 : 64). The findings of the present investigation revealed the high seroprevalence of T. gondii in sows in Hunan province, China, which poses a potential risk for T. gondii infection in humans and animals in this province. Therefore, effective measures should be taken to prevent and control toxoplasmosis of pigs in this province. This is the first report of the comprehensive survey of T. gondii seroprevalence in sows in Hunan Province, subtropical China.
PMCID: PMC3932812
9.  Ivor-Lewis esophagectomy for esophageal cancer after distal gastrectomy 
Journal of Thoracic Disease  2014;6(2):E22-E26.
We report the use of gastric remnant for esophageal substitution after distal gastrectomy in a 53-year-old man with esophageal cancer. This patient had a 4-month history of progressive dysphagia for solid food. An upper gastrointestinal endoscopy showed a 7.0 cm bulge tumor in the middle-lower esophagus, wherein the upper margin was located 28 cm from the dental arcade. Computed tomography (CT) of the chest revealed wall thickening in the middle-lower esophagus. In this case, radical en bloc esophagectomy with a two-field lymph node dissection was performed in the upper abdomen and mediastinum via a posterolateral right thoracotomy through the fifth intercostal space. Esophagogastric anastomosis was performed mechanically in the apex of the chest using a circular stapler. The gastric remnant was used for reconstruction of the esophago-gastrostomy and placed in the right thoracic cavity. The patient was discharged on the 12th postoperative day without complications. The gastric remnant may be used for reconstruction in patients with esophageal cancer as a substitute organ after distal gastrectomy.
PMCID: PMC3944176  PMID: 24605241
Gastric remnant; distal; gastrectomy; esophageal cancer; substitution
10.  Hypoxia Inducible Factor-2α Regulates the Development of Retinal Astrocytic Network by Maintaining Adequate Supply of Astrocyte Progenitors 
PLoS ONE  2014;9(1):e84736.
Here we investigate the role of hypoxia inducible factor (HIF)-2α in coordinating the development of retinal astrocytic and vascular networks. Three Cre mouse lines were used to disrupt floxed Hif-2α, including Rosa26CreERT2, Tie2Cre, and GFAPCre. Global Hif-2α disruption by Rosa26CreERT2 led to reduced astrocytic and vascular development in neonatal retinas, whereas endothelial disruption by Tie2Cre had no apparent effects. Hif-2α deletion in astrocyte progenitors by GFAPCre significantly interfered with the development of astrocytic networks, which failed to reach the retinal periphery and were incapable of supporting vascular development. Perplexingly, the abundance of strongly GFAP+ mature astrocytes transiently increased at P0 before they began to lag behind the normal controls by P3. Pax2+ and PDGFRα+ astrocytic progenitors and immature astrocytes were dramatically diminished at all stages examined. Despite decreased number of astrocyte progenitors, their proliferation index or apoptosis was not altered. The above data can be reconciled by proposing that HIF-2α is required for maintaining the supply of astrocyte progenitors by slowing down their differentiation into non-proliferative mature astrocytes. HIF-2α deficiency in astrocyte progenitors may accelerate their differentiation into astrocytes, a change which greatly interferes with the replenishment of astrocyte progenitors due to insufficient time for proliferation. Rapidly declining progenitor supply may lead to premature cessation of astrocyte development. Given that HIF-2α protein undergoes oxygen dependent degradation, an interesting possibility is that retinal blood vessels may regulate astrocyte differentiation through their oxygen delivery function. While our findings support the consensus that retinal astrocytic template guides vascular development, they also raise the possibility that astrocytic and vascular networks may mutually regulate each other's development, mediated at least in part by HIF-2α.
PMCID: PMC3903483  PMID: 24475033
11.  Myeloid-Derived Suppressor Cells Are Associated with Viral Persistence and Downregulation of TCR ζ Chain Expression on CD8+ T Cells in Chronic Hepatitis C Patients 
Molecules and Cells  2014;37(1):66-73.
Myeloid-derived suppressor cells (MDSCs) play an important role in impairing the function of T cells. We characterized MDSCs in two chronic hepatitis C (CHC) cohorts: a cross-sectional group that included 61 treatment-naive patients with CHC, 14 rapid virologic response (RVR) cases and 22 early virologic response (EVR) cases; and a longitudinal group of 13 cases of RVR and 10 cases of EVR after pegylated-interferon-α/ribavirin treatment for genotype 1b HCV infection. Liver samples from 32 CHC patients and six healthy controls were subjected to immunohistochemical analysis. MDSCs frequency in treatment-naive CHC was significantly higher than in RVR, EVR, or healthy subjects and was positively correlated with HCV RNA. Patients infected with HCV genotype 2a had a significantly higher frequency of MDSCs than those infected with genotype 1b. Decreased T cell receptor (TCR) ζ expression on CD8+ T cells was significantly associated with an increased frequency of MDSCs in treatment-naive CHC patients and was restored by L-arginine treatment in vitro. Increased numbers of liver arginase-1+ cells were closely associated with the histological activity index in CHC. The TCR ζ chain was significantly downregulated on hepatic CD8+ T cells in CHC. During antiviral follow up, MDSCs frequency in peripheral blood mononuclear cells was directly correlated with the HCV RNA load in the plasma and inversely correlated with TCR ζ chain expression in CD8+ T cells in both RVR and EVR cases. Notably, the RVR group had a higher frequency of MDSCs at baseline than the EVR group. Collectively, this study provides evidence that MDSCs might be associated with HCV persistence and downregulation of CD8 ζ chain expression.
PMCID: PMC3907002  PMID: 24552712
arginase-1; hepatitis C virus; L-arginine; myeloid-derived suppressor cell; TCR ζ chain
12.  Prediction of Aptamer-Target Interacting Pairs with Pseudo-Amino Acid Composition 
PLoS ONE  2014;9(1):e86729.
Aptamers are oligonucleic acid or peptide molecules that bind to specific target molecules. As a novel and powerful class of ligands, aptamers are thought to have excellent potential for applications in the fields of biosensing, diagnostics and therapeutics. In this study, a new method for predicting aptamer-target interacting pairs was proposed by integrating features derived from both aptamers and their targets. Features of nucleotide composition and traditional amino acid composition as well as pseudo amino acid were utilized to represent aptamers and targets, respectively. The predictor was constructed based on Random Forest and the optimal features were selected by using the maximum relevance minimum redundancy (mRMR) method and the incremental feature selection (IFS) method. As a result, 81.34% accuracy and 0.4612 MCC were obtained for the training dataset, and 77.41% accuracy and 0.3717 MCC were achieved for the testing dataset. An optimal feature set of 220 features were selected, which were considered as the ones that contributed significantly to the interacting aptamer-target pair predictions. Analysis of the optimal feature set indicated several important factors in determining aptamer-target interactions. It is anticipated that our prediction method may become a useful tool for identifying aptamer-target pairs and the features selected and analyzed in this study may provide useful insights into the mechanism of interactions between aptamers and targets.
PMCID: PMC3899287  PMID: 24466214
13.  Chabertia erschowi (Nematoda) is a distinct species based on nuclear ribosomal DNA sequences and mitochondrial DNA sequences 
Parasites & Vectors  2014;7:44.
Gastrointestinal nematodes of livestock have major socio-economic importance worldwide. In small ruminants, Chabertia spp. are responsible for economic losses to the livestock industries globally. Although much attention has given us insights into epidemiology, diagnosis, treatment and control of this parasite, over the years, only one species (C. ovina) has been accepted to infect small ruminants, and it is not clear whether C. erschowi is valid as a separate species.
The first and second internal transcribed spacers (ITS-1 and ITS-2) regions of nuclear ribosomal DNA (rDNA) and the complete mitochondrial (mt) genomes of C. ovina and C. erschowi were amplified and then sequenced. Phylogenetic re-construction of 15 Strongylida species (including C. erschowi) was carried out using Bayesian inference (BI) based on concatenated amino acid sequence datasets.
The ITS rDNA sequences of C. ovina China isolates and C. erschowi samples were 852–854 bp and 862 -866 bp in length, respectively. The mt genome sequence of C. erschowi was 13,705 bp in length, which is 12 bp shorter than that of C. ovina China isolate. The sequence difference between the entire mt genome of C. ovina China isolate and that of C. erschowi was 15.33%. In addition, sequence comparison of the most conserved mt small subunit ribosomal (rrnS) and the least conserved nad2 genes among multiple individual nematodes revealed substantial nucleotide differences between these two species but limited sequence variation within each species.
The mtDNA and rDNA datasets provide robust genetic evidence that C. erschowi is a valid strongylid nematode species. The mtDNA and rDNA datasets presented in the present study provide useful novel markers for further studies of the taxonomy and systematics of the Chabertia species from different hosts and geographical regions.
PMCID: PMC3937141  PMID: 24450932
Chabertia spp; Nuclear ribosomal DNA; Internal transcribed spacer (ITS); Mitochondrial DNA; Phylogenetic analysis
14.  Deletion of Gpr128 results in weight loss and increased intestinal contraction frequency 
AIM: To generate a Gpr128 gene knockout mouse model and to investigate its phenotypes and the biological function of the Gpr128 gene.
METHODS: Bacterial artificial chromosome-retrieval methods were used for constructing the targeting vector. Using homologous recombination and microinjection technology, a Gpr128 knockout mouse model on a mixed 129/BL6 background was generated. The mice were genotyped by polymerase chain reaction (PCR) analysis of tail DNA and fed a standard laboratory chow diet. Animals of both sexes were used, and the phenotypes were assessed by histological, biochemical, molecular and physiological analyses. Semi-quantitative reverse transcription-PCR and Northern blotting were used to determine the tissue distribution of Gpr128 mRNA. Beginning at the age of 4 wk, body weights were recorded every 4 wk. Food, feces, blood and organ samples were collected to analyze food consumption, fecal quantity, organ weight and constituents of the blood and plasma. A Trendelenburg preparation was utilized to examine intestinal motility in wild-type (WT) and Gpr128-/- mice at the age of 8 and 32 wk.
RESULTS: Gpr128 mRNA was highly and exclusively detected in the intestinal tissues. Targeted deletion of Gpr128 in adult mice resulted in reduced body weight gain, and mutant mice exhibited an increased frequency of peristaltic contraction and slow wave potential of the small intestine. The Gpr128+/+ mice gained more weight on average than the Gpr128-/- mice since 24 wk, being 30.81 ± 2.84 g and 25.74 ± 4.50 g, respectively (n = 10, P < 0.01). The frequency of small intestinal peristaltic contraction was increased in Gpr128-/- mice. At the age of 8 wk, the frequency of peristalsis with an intraluminal pressure of 3 cmH2O was 6.6 ± 2.3 peristalsis/15 min in Gpr128-/- intestine (n = 5) vs 2.6 ± 1.7 peristalsis/15 min in WT intestine (n = 5, P < 0.05). At the age of 32 wk, the frequency of peristaltic contraction with an intraluminal pressure of 2 and 3 cmH2O was 4.6 ± 2.3 and 3.1 ± 0.8 peristalsis/15 min in WT mice (n = 8), whereas in Gpr128-/- mice (n = 8) the frequency of contraction was 8.3 ± 3.0 and 7.4 ± 3.1 peristalsis/15 min, respectively (2 cmH2O: P < 0.05 vs WT; 3 cmH2O: P < 0.01 vs WT). The frequency of slow wave potential in Gpr128-/- intestine (35.8 ± 4.3, 36.4 ± 4.2 and 37.1 ± 4.8/min with an intraluminal pressure of 1, 2 and 3 cmH2O, n = 8) was also higher than in WT intestine (30.6 ± 4.2, 31.4 ± 3.9 and 31.9 ± 4.5/min, n = 8, P < 0.05).
CONCLUSION: We have generated a mouse model with a targeted deletion of Gpr128 and found reduced body weight and increased intestinal contraction frequency in this animal model.
PMCID: PMC3923024  PMID: 24574718
G-protein-coupled receptors; Gpr128; Knockout mouse; Weight loss; Intestinal contraction frequency
15.  CD13 promotes mesenchymal stem cell-mediated regeneration of ischemic muscle 
Mesenchymal stem cells (MSCs) are multipotent, tissue-resident cells that can facilitate tissue regeneration and thus, show great promise as potential therapeutic agents. Functional MSCs have been isolated and characterized from a wide array of adult tissues and are universally identified by the shared expression of a core panel of MSCs markers. One of these markers is the multifunctional cell surface peptidase CD13 that has been shown to be expressed on human and murine MSCs from many tissues. To investigate whether this universal expression indicates a functional role for CD13 in MSC biology we isolated, expanded and characterized MSCs from bone marrow of wild type (WT) and CD13KO mice. Characterization of these cells demonstrated that both WT and CD13KO MSCs expressed the full complement of MSC markers (CD29, CD44, CD49e, CD105, Sca1), showed comparable proliferation rates and were capable of differentiating toward the adipogenic and osteogenic lineages. However, MSCs lacking CD13 were unable to differentiate into vascular cells, consistent with our previous characterization of CD13 as an angiogenic regulator. Compared to WT MSCs, adhesion and migration on various extracellular matrices of CD13KO MSCs were significantly impaired, which correlated with decreased phospho-FAK levels and cytoskeletal alterations. Crosslinking human MSCs with activating CD13 antibodies increased cell adhesion to endothelial monolayers and induced FAK activation in a time dependent manner. In agreement with these in vitro data, intramuscular injection of CD13KO MSCs in a model of severe ischemic limb injury resulted in significantly poorer perfusion, decreased ambulation, increased necrosis and impaired vascularization compared to those receiving WT MSCs. This study suggests that CD13 regulates FAK activation to promote MSC adhesion and migration, thus, contributing to MSC-mediated tissue repair. CD13 may present a viable target to enhance the efficacy of mesenchymal stem cell therapies.
PMCID: PMC3885827  PMID: 24409152
CD13; mesenchymal stem cells; adhesion; cell transplantation; hindlimb ischemia
16.  Combating trastuzumab resistance by targeting SRC, a common node downstream of multiple resistance pathways 
Nature medicine  2011;17(4):10.1038/nm.2309.
Trastuzumab is a successful rationally designed ERBB2-targeted therapy. However, about half of individuals with ERBB2-overexpressing breast cancer do not respond to trastuzumab-based therapies, owing to various resistance mechanisms. Clinically applicable regimens for overcoming trastuzumab resistance of different mechanisms are not yet available. We show that the nonreceptor tyrosine kinase c-SRC (SRC) is a key modulator of trastuzumab response and a common node downstream of multiple trastuzumab resistance pathways. We find that SRC is activated in both acquired and de novo trastuzumab-resistant cells and uncover a novel mechanism of SRC regulation involving dephosphorylation by PTEN. Increased SRC activation conferred considerable trastuzumab resistance in breast cancer cells and correlated with trastuzumab resistance in patients. Targeting SRC in combination with trastuzumab sensitized multiple lines of trastuzumab-resistant cells to trastuzumab and eliminated trastuzumab-resistant tumors in vivo, suggesting the potential clinical application of this strategy to overcome trastuzumab resistance.
PMCID: PMC3877934  PMID: 21399647
17.  A Comparison of Growth and Development of Three Major Agricultural Insect Pests Infected with Heliothis virescens ascovirus 3h (HvAV-3h) 
PLoS ONE  2013;8(12):e85704.
Ascoviruses are double-stranded DNA viruses that are pathogenic to lepidopteran hosts, particularly noctuid larvae. Infection of a larva is characterized by retarded growth, reduced feeding and yellowish body color. In this paper, we reported the growth and development of three major agricultural noctuid insect pests, Helicoverpa armigera (Hübner), Spodoptera exigua (Hübner) and Spodoptera litura (Fabricius), infected with Heliothis virescens ascovirus 3h (HvAV-3h). Using 10-fold serial dilutions (0 to 7) of HvAV-3h-containing hemolymph to infect S. litura larvae, we found no significant difference in larval mortalities from 0 to 103-fold dilutions; however, significant differences were observed at 104-fold dilution and above. Using a 10-fold dilution of HvAV-3h-containing hemolymph to infect H. armigera, S. exigua and S. litura larvae, we found that the growth and development were significantly affected. All infected larvae could not pupate; the survival times of treated H. armigera, S. litura and S. exigua larvae were significantly longer than untreated control larvae. Body weight showed significant difference between treated and untreated control group from day 1 after inoculation in H. armigera and S. exigua, but day 2 in S. litura. Additionally, food intake also showed significant difference between treated and untreated control group from day 2 after inoculation in H. armigera and S. litura, but day 3 in S. exigua.
PMCID: PMC3875588  PMID: 24386488
18.  A Mathematical Model with Pulse Effect for Three Populations of the Giant Panda and Two Kinds of Bamboo 
The Scientific World Journal  2013;2013:137384.
A mathematical model for the relationship between the populations of giant pandas and two kinds of bamboo is established. We use the impulsive perturbations to take into account the effect of a sudden collapse of bamboo as a food source. We show that this system is uniformly bounded. Using the Floquet theory and comparison techniques of impulsive equations, we find conditions for the local and global stabilities of the giant panda-free periodic solution. Moreover, we obtain sufficient conditions for the system to be permanent. The results provide a theoretical basis for giant panda habitat protection.
PMCID: PMC3871913  PMID: 24381508
19.  Prediction of Drugs Target Groups Based on ChEBI Ontology 
BioMed Research International  2013;2013:132724.
Most drugs have beneficial as well as adverse effects and exert their biological functions by adjusting and altering the functions of their target proteins. Thus, knowledge of drugs target proteins is essential for the improvement of therapeutic effects and mitigation of undesirable side effects. In the study, we proposed a novel prediction method based on drug/compound ontology information extracted from ChEBI to identify drugs target groups from which the kind of functions of a drug may be deduced. By collecting data in KEGG, a benchmark dataset consisting of 876 drugs, categorized into four target groups, was constructed. To evaluate the method more thoroughly, the benchmark dataset was divided into a training dataset and an independent test dataset. It is observed by jackknife test that the overall prediction accuracy on the training dataset was 83.12%, while it was 87.50% on the test dataset—the predictor exhibited an excellent generalization. The good performance of the method indicates that the ontology information of the drugs contains rich information about their target groups, and the study may become an inspiration to solve the problems of this sort and bridge the gap between ChEBI ontology and drugs target groups.
PMCID: PMC3853244  PMID: 24350241
20.  Icariin Augments Bone Formation and Reverses the Phenotypes of Osteoprotegerin-Deficient Mice through the Activation of Wnt/β-Catenin-BMP Signaling 
Icariin has been mostly reported to enhance bone fracture healing and treat postmenopausal osteoporosis in ovariectomized animal model. As another novel animal model of osteoporosis, there is few publication about the effect of Icariin on osteoprotegerin-deficient mice. Therefore, the goal of this study is to find the effect on bone formation and underlying mechanisms of Icariin in osteoprotegerin (OPG) knockout (KO) mice. We found that Icariin significantly stimulated new bone formation after local injection over the surface of calvaria at the dose of 5 mg/kg per day. With this dose, Icariin was also capable of significantly reversing OPG-deficient-induced bone loss and bone strength reduction. Real-time PCR analysis showed that Icariin significantly upregulated the expression of BMP2, BMP4, RUNX2, OC, Wnt1, and Wnt3a in OPG KO mice. Icariin also significantly increased the expression of AXIN2, DKK1, TCF1, and LEF1, which are the direct target genes of β-catenin signaling. The in vitro studies showed that Icariin induced osteoblast differentiation through the activation of Wnt/β-catenin-BMP signaling by in vitro deletion of the β-catenin gene using β-cateninfx/fx mice. Together, our findings demonstrate that Icariin significantly reverses the phenotypes of OPG-deficient mice through the activation of Wnt/β-catenin-BMP signaling.
PMCID: PMC3835354  PMID: 24348713
21.  Effect of Vasoactive Intestinal Peptide (VIP) on NKG2D Signal Pathway and Its Contribution to Immune Escape of MKN45 Cells 
The Scientific World Journal  2013;2013:429545.
Objective. To investigate VIP effect on the cytotoxicity of NK cell to gastric cancer cells in vitro and the relation between the effect with the NKG2D signal molecules in NK cells. Material and Methods. NK cells were purified from peripheral blood mononuclear cells (PBMC). Before and after NK cells were incubated with VIP or its antagonist (D-p-Cl-Phe6,Leu17)-VIP, we detected the cytotoxicity of NK cells to MKN45 gastric cancer cells by MTT and detected the expressions of NKG2D, DAP10, and NF-κB proteins and mRNAs in NK cells by immunocytochemistry and RT-PCR in those conditions. Then we analyzed the effect of VIP and its antagonist on the cytotocicity of NK cell to gastric cancer cells and on expressions of NKG2D, DAP10, and NF-κB signal molecules in NK cells. Results. VIP could inhibit the cytotoxicity of NK cells to MKN45 cells and could inhibit the expressions of NKG2D, DAP10, and NF-κB in NK cells. However, (D-p-Cl-Phe6, Leu17)-VIP could reverse those effects. Conclusions. The VIP inhibited the cytotoxicity of NK cell to MKN45 cells which might get through inhibiting the expressions of NKG2D signal molecules in NK cells. This may be one mechanism of gastric cancer cells escaping organism immune clearance.
PMCID: PMC3817657  PMID: 24228003
22.  Effects of midazolam, pentobarbital and ketamine on the mRNA expression of ion channels in a model organism Daphnia pulex 
BMC Anesthesiology  2013;13:32.
Over the last few decades intensive studies have been carried out on the molecular targets mediating general anesthesia as well as the effects of general anesthetics. The γ-aminobutyric acid type A receptor (GABAAR) has been indicated as the primary target of general anaesthetics such as propofol, etomidate and isoflurane, and sedating drugs including benzodiazepines and barbiturates. The GABAAR is also involved in drug tolerance and dependence. However, the involvement of other ion channels is possible.
Using reverse transcription and quantitative PCR techniques, we systematically investigated changes in the mRNA levels of ion channel genes in response to exposure to midazolam, pentobarbital and ketamine in a freshwater model animal, Daphnia pulex. To retrieve the sequences of Daphnia ion channel genes, Blast searches were performed based on known human or Drosophila ion channel genes. Retrieved sequences were clustered with the maximum-likelihood method. To quantify changes in gene expression after the drug treatments for 4 hours, total RNA was extracted and reverse transcribed into cDNA and then amplified using quantitative PCR.
A total of 108 ion channel transcripts were examined, and 19, 11 and 11 of them are affected by midazolam (100 μM), pentobarbital (200 μM) and ketamine (100 μM), respectively, covering a wide variety of ion channel types. There is some degree of overlap with midazolam- and pentobarbital-induced changes in the mRNA expression profiles, but ketamine causes distinct changes in gene expression pattern.
In addition, flumazenil (10 μM) eliminates the effect of midazolam on the mRNA expression of the GABAA receptor subunit Rdl, suggesting a direct interaction between midazolam and GABAA receptors.
Recent research using high throughput technology suggests that changes in mRNA expression correlate with delayed protein expression. Therefore, the mRNA profile changes in our study may reflect the molecular targets not only in drug actions, but also in chronic drug addiction. Our data also suggest the possibility that hypnotic/anesthetic drugs are capable of altering the functions of the nervous system, as well as those non-nerve tissues with abundant ion channel expressions.
PMCID: PMC3879215  PMID: 24134334
Midazolam; Pentobarbital; Ketamine; mRNA; Ion channel; Daphnia pulex
23.  Expression and Significance of MicroRNA-183 in Hepatocellular Carcinoma 
The Scientific World Journal  2013;2013:381874.
Objective. In our previous study, we found that some miRNAs were deregulated in hepatocellular carcinoma (HCC), including miR-183. However, the expression of miR-183 in the progression of benign liver diseases to HCC and its correlation with clinicopathologic factors remain undefined. Methods. MiR-183 expression was measured in normal controls (NC) (n = 21), chronic viral hepatitis B or C (CH) tissues (n = 10), liver cirrhosis (LC) tissues (n = 18), HCC tissues (n = 92), and adjacent nontumor tissues (NT) (n = 92) by quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR). Results. The expression levels of miR-183 were significantly higher in HCC than in NT, LC, CH, and NL (P = 0.001, P < 0.001, P = 0.011, P < 0.001, resp.). The upregulated miR-183 in HCC was correlated with TNM stage (P = 0.042) and cirrhosis (P = 0.025). The Kaplan-Meier survival analysis showed that miR-183 expression was not associated with the survival of HCC patients. However, miR-183 yielded an area under the curve (AUC) of 0.808 with 59.8% sensitivity and 91.8% specificity in discriminating HCC from benign liver diseases (CH and LC) or NC. Conclusions. The upregulated miR-183 may associate with onset and progression of HCC, but not with the patient survival. A further research is needed to determine the potential of miR-183 as biomarker for HCC.
PMCID: PMC3810064  PMID: 24222732
24.  Expression and Clinical Significance of Livin Protein in Hepatocellular Carcinoma 
Disease markers  2013;35(5):489-496.
In this study, the two-step PV method of immunohistochemistry was used to determine livin protein expression in HCC tissues, pericarcinoma tissues, hepatitis/hepatic cirrhosis tissues, and normal hepatic tissues, and livin protein expression was detected in the blood plasma of patients with HCC before and after surgery, subjects with hepatic cirrhosis and hepatitis, and healthy blood donors using ELISA. Livin protein expression was significantly higher in HCC tissues than that in normal hepatic tissues and hepatitis/hepatic cirrhosis tissues, with no significant difference between HCC tissues and pericarcinoma tissues. The HCC patients with positive livin protein expression had a significantly higher survival rate than those with negative livin protein expression. Livin protein expression was significantly higher in the blood plasma of patients with HCC before and after surgery and in patients with hepatic cirrhosis and hepatitis than that in healthy blood donors, whereas livin protein expression in the blood plasma of patients with HCC was not significantly different from that of patients with hepatic cirrhosis and hepatitis. Livin protein expression in HCC tissues did not correlate with that in the blood plasma of the same HCC patients. Livin protein expression may be a potential, effective indicator for assessing prognosis in patients with HCC.
PMCID: PMC3810112  PMID: 24223461
25.  A Spherically-Shaped PZT Thin Film Ultrasonic Transducer with an Acoustic Impedance Gradient Matching Layer Based on a Micromachined Periodically Structured Flexible Substrate 
Sensors (Basel, Switzerland)  2013;13(10):13543-13559.
This paper presents the microfabrication of an acoustic impedance gradient matching layer on a spherically-shaped piezoelectric ultrasonic transducer. The acoustic matching layer can be designed to achieve higher acoustic energy transmission and operating bandwidth. Also included in this paper are a theoretical analysis of the device design and a micromachining technique to produce the novel transducer. Based on a design of a lead titanium zirconium (PZT) micropillar array, the constructed gradient acoustic matching layer has much better acoustic transmission efficiency within a 20–50 MHz operation range compared to a matching layer with a conventional quarter-wavelength thickness Parylene deposition. To construct the transducer, periodic microcavities are built on a flexible copper sheet, and then the sheet forms a designed curvature with a ball shaping. After PZT slurry deposition, the constructed PZT micropillar array is released onto a curved thin PZT layer. Following Parylene conformal coating on the processed PZT micropillars, the PZT micropillars and the surrounding Parylene comprise a matching layer with gradient acoustic impedance. By using the proposed technique, the fabricated transducer achieves a center frequency of 26 MHz and a −6 dB bandwidth of approximately 65%.
PMCID: PMC3859077  PMID: 24113683
PZT film; ultrasonic transducer; micromachining; acoustic impedance

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