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1.  Hes1, an important gene for activation of hepatic stellate cells, is regulated by Notch1 and TGF-β/BMP signaling 
AIM: To determine the role of Notch1 and Hes1 in regulating the activation of hepatic stellate cells (HSCs) and whether Hes1 is regulated by transforming growth factor (TGF)/bone morphogenetic protein (BMP) signaling.
METHODS: Immunofluorescence staining was used to detect the expression of desmin, glial fibrillary acidic protein and the myofibroblastic marker α-smooth muscle actin (α-SMA) after freshly isolated, normal rat HSCs had been activated in culture for different numbers of days (0, 1, 3, 7 and 10 d). The expression of α-SMA, collagen1α2 (COL1α2), Notch receptors (Notch1-4), and the Notch target genes Hes1 and Hey1 were analyzed by reverse transcriptase-polymerase chain reaction. Luciferase reporter assays and Western blot were used to study the regulation of α-SMA, COL1α1, COL1α2 and Hes1 by NICD1, Hes1, CA-ALK3, and CA-ALK5 in HSC-T6 cells. Moreover, the effects of inhibiting Hes1 function in HSC-T6 cells using a Hes1 decoy were also investigated.
RESULTS: The expression of Notch1 and Hes1 mRNAs was significantly down-regulated during the culture of freshly isolated HSCs. In HSC-T6 cells, Notch1 inhibited the promoter activities of α-SMA, COL1α1 and COL1α2. On the other hand, Hes1 enhanced the promoter activities of α-SMA and COL1α2, and this effect could be blocked by inhibiting Hes1 function with a Hes1 decoy. Furthermore, co-transfection of pcDNA3-CA-ALK3 (BMP signaling activin receptor-like kinase 3) and pcDNA3.1-NICD1 further increased the expression of Hes1 compared with transfection of either vector alone in HSC-T6 cells, while pcDNA3-CA-ALK5 (TGF-β signaling activin receptor-like kinase 5) reduced the effect of NICD1 on Hes1 expression.
CONCLUSION: Selective interruption of Hes1 or maintenance of Hes1 at a reasonable level decreases the promoter activities of α-SMA and COL1α2, and these conditions may provide an anti-fibrotic strategy against hepatic fibrosis.
PMCID: PMC4299340  PMID: 25624721
Hes1; Notch1; TGF-β/BMP; Hepatic stellate cells; Hepatic fibrosis
2.  Antibacterial activity and biological performance of a novel antibacterial coating containing a halogenated furanone compound loaded poly(L-lactic acid) nanoparticles on microarc-oxidized titanium 
Titanium implants have been widely used for many medical applications, but bacterial infection after implant surgery remains one of the most common and intractable complications. To this end, long-term antibacterial ability of the implant surface is highly desirable to prevent implant-associated infection. In this study, a novel antibacterial coating containing a new antibacterial agent, (Z-)-4-bromo-5-(bromomethylene)-2(5H)-furanone loaded poly(L-lactic acid) nanoparticles, was fabricated on microarc-oxidized titanium for this purpose. The antibacterial coating produced a unique inhibition zone against Staphylococcus aureus throughout a 60-day study period, which is normally long enough to prevent the infection around implants in the early and intermediate stages. The antibacterial rate for adherent S. aureus was about 100% in the first 10 days and constantly remained over 90% in the following 20 days. Fluorescence staining of adherent S. aureus also confirmed the excellent antibacterial ability of the antibacterial coating. Moreover, in vitro experiments showed an enhanced osteoblast adhesion and proliferation on the antibacterial coating, and more notable cell spread was observed at the early stage. It is therefore concluded that the fabricated antibacterial coating, which exhibits relatively long-term antibacterial ability and excellent biological performance, is a potential and promising strategy to prevent implant-associated infection.
PMCID: PMC4304594  PMID: 25632231
microarc oxidation; osteoblasts
3.  Role of microRNAs in diagnosis and treatment of the pathogenesis of gastric cancer 
We aim to detect the miRNAs that are correlated with the gastric cancer cell line SGC-7901 to provide theoretical basis for clinical application. We first analyzed miRNA expression profiles of gastric cancer patients compared with normal controls by microarray analysis and validated the results by real-time qPCR. We also determined the absolute copy numbers of these three miRNAs in normal adults. The results showed that three miRNAs (miR-150, miR-23a, and miR-130a) were identified to significantly decrease in expanded 38 gastric cancer patients compared with 90 normal controls. Molecular and statistical analysis showed that the decreased miRNAs were significant in clinical analysis. Generally speaking, this finding suggest vital roles of these miRNAs in human gastric cancer genesis and as potential biomarkers in gastric cancer diagnosis.
PMCID: PMC4307587  PMID: 25664140
microRNAs; gastric cancer; SGC-7901; diagnosis biomarker
4.  Clinical characteristics and prognosis of primary pancreatic carcinoid tumors: A report of 13 cases from a single institution 
Oncology Letters  2014;9(2):780-784.
The present study aimed to analyze the diagnosis and treatment of 13 cases of pancreatic carcinoid tumors during a 56-year period at the Tianjin Medical University Cancer Institute and Hospital (Tianjin, China). The data from 13 cases, consisting of 5 males and 8 females (mean age, 50 years), were collected and analyzed. Hematoxylin-eosin and immunohistochemistry staining were performed to investigate the expression of neuron-specific enolase (NSE), cytokeratin (CK), chromogranin A (CgA) and synaptophysin (Syn) in the tumors. The affected patients suffered abdominal and/or back pain without typical carcinoid syndrome. Radical resection was performed in 10 cases and regional resection in one case. The remaining two patients exhbited remote metastasis, and so were treated with single and double bypass surgery (choledochojejunostomy and gastrojejunostomy/choledochojejunostomy, respectively). The expression of CK, Syn, CgA and NSE was positive in nine (69.23%), 10 (76.92%), five (38.46%) and eight (61.54%) cases, respectively. The median survival time was 26.6 months. In conclusion, in patients with pancreatic carcinoid tumors that exhibit no typical carcinoid syndrome, such as those in the present study, the diagnosis can be confirmed by pathological examination and surgery is the most effective treatment.
PMCID: PMC4301509  PMID: 25621051
pancreatic carcinoid tumor; diagnosis; treatment; prognosis; pathology
5.  Good neurological recovery after rescue thrombolysis of presumed pulmonary embolism despite prior 100 minutes CPR 
Journal of Thoracic Disease  2014;6(12):E289-E293.
We reported the case of a 70-year-old man who was admitted to neurologic wards for recurrent syncope for 3 years. Unfortunately, just 2 hours after his admission, he suddenly collapsed and failed to return of spontaneous circulation (ROSC) after a 100-minute standard cardiopulmonary resuscitation (CPR). Fortunately, he was timely suspected to have pulmonary embolism (PE) based on his sedentary lifestyle, elevated D-dimer and markedly enlarged right ventricle chamber on bedside echocardiography. After a rescue thrombolytic alteplase therapy, he was successfully resuscitated and good neurological recovery was achieved.
PMCID: PMC4283306  PMID: 25590010
Cardiac arrest; pulmonary embolism (PE); thrombolysis
6.  Rac1 mediates laminar shear stress-induced vascular endothelial cell migration 
Cell Adhesion & Migration  2013;7(6):462-468.
The migration of endothelial cells (ECs) plays an important role in vascular remodeling and regeneration. ECs are constantly subjected to shear stress resulting from blood flow and are able to convert mechanical stimuli into intracellular signals that affect cellular behaviors and functions. The aim of this study is to elucidate the effects of Rac1, which is the member of small G protein family, on EC migration under different laminar shear stress (5.56, 10.02, and 15.27 dyn/cm2). The cell migration distance under laminar shear stress increased significantly than that under the static culture condition. Especially, under relative high shear stress (15.27 dyn/cm2) there was a higher difference at 8 h (P < 0.01) and 2 h (P < 0.05) compared with static controls. RT-PCR results further showed increasing mRNA expression of Rac1 in ECs exposed to laminar shear stress than that exposed to static culture. Using plasmids encoding the wild-type (WT), an activated mutant (Q61L), and a dominant-negative mutant (T17N), plasmids encoding Rac1 were transfected into EA.hy 926 cells. The average net migration distance of Rac1Q61L group increased significantly, while Rac1T17N group decreased significantly in comparison with the static controls. These results indicated that Rac1 mediated shear stress-induced EC migration. Our findings conduce to elucidate the molecular mechanisms of EC migration induced by shear stress, which is expected to understand the pathophysiological basis of wound healing in health and diseases.
PMCID: PMC3916349  PMID: 24430179
Rac1; shear stress; endothelial cell migration
7.  Phase-pure iron pyrite nanocrystals for low-cost photodetectors 
Nanoscale Research Letters  2014;9(1):549.
Earth-abundant iron pyrite (FeS2) shows great potential as a light absorber for solar cells and photodetectors due to their high absorption coefficient (>105 cm-1). In this paper, high-quality phase-pure and single crystalline pyrite nanocrystals were synthesized via facile, low-cost, and environment friendly hydrothermal method. The molar ratio of sulphur to iron and the reaction time play a crucial role in determining the quality and morphology of FeS2 nanocrystals. X-ray diffraction and high-resolution transmission electron microscopy confirm that phase-pure and single crystalline pyrite nanocrystals can be synthesized with high sulphur to iron molar ratio and sufficient reaction time. For the first time, a crystalline nanogap pyrite photodetector with promising photocurrent and UV-visible photoresponse has been fabricated. This work further demonstrates a facile route to synthesize high-quality FeS2 nanomaterials and their potential in optoelectronic applications.
PMCID: PMC4194451  PMID: 25317102
Iron pyrite; Photodetector; Hydrothermal; Nanocrystal
8.  Microwave fabrication of Cu2ZnSnS4 nanoparticle and its visible light photocatalytic properties 
Nanoscale Research Letters  2014;9(1):477.
Cu2ZnSnS4 nanoparticle with an average diameter of approximately 31 nm has been successfully synthesized by a time effective microwave fabrication method. The crystal structure, surface morphology, and microstructure of the Cu2ZnSnS4 nanoparticle were characterized. Moreover, the visible light photocatalytic ability of the Cu2ZnSnS4 nanoparticle toward degradation of methylene blue (MB) was also studied. About 30% of MB was degraded after 240 min irradiation when employing Cu2ZnSnS4 nanoparticle as a photocatalyst. However, almost all MB was decomposed after 90 min irradiation when introducing a small amount of H2O2 as a co-photocatalyst. The enhancement of the photocatalytic performance was attributed to the synergetic effect between the Cu2ZnSnS4 nanoparticle and H2O2. The detailed photocatalytic degradation mechanism of MB by the Cu2ZnSnS4 was further proposed.
PMCID: PMC4165623  PMID: 25237289
Cu2ZnSnS4; Microwave fabrication; Photocatalyst
9.  Inhibition of Autophagy via Activation of PI3K/Akt Pathway Contributes to the Protection of Ginsenoside Rb1 against Neuronal Death Caused by Ischemic Insults 
Lethal autophagy is a pathway leading to neuronal death caused by transient global ischemia. In this study, we examined the effect of Ginsenoside Rb1 (GRb1) on ischemia/reperfusion-induced autophagic neuronal death and investigated the role of PI3K/Akt. Ischemic neuronal death in vitro was induced by using oxygen glucose deprivation (OGD) in SH-SY5Y cells, and transient global ischemia was produced by using two vessels occlusion in rats. Cellular viability of SH-SY5Y cells was assessed by MTT assay, and CA1 neuronal death was evaluated by Hematoxylin-eosin staining. Autophagic vacuoles were detected by using both fluorescent microscopy in combination with acridine orange (AO) and Monodansylcadaverine (MDC) staining and transmission electronic microscopy. Protein levels of LC3II, Beclin1, total Akt and phosphor-Akt at Ser473 were examined by western blotting analysis. GRb1 inhibited both OGD and transient ischemia-induced neuronal death and mitigated OGD-induced autophagic vacuoles in SH-SY5Y cells. By contrast, PI3K inhibitor LY294002 counteracted the protection of GRb1 against neuronal death caused by either OGD or transient ischemia. LY294002 not only mitigated the up-regulated protein level of phosphor Akt at Ser473 caused by GRb1, but also reversed the inhibitory effect of GRb1 on OGD and transient ischemia-induced elevation in protein levels of LC3II and Beclin1.
PMCID: PMC4200757  PMID: 25257523
autophagy; OGD; transient global ischemia; Ginsenoside Rb1; PI3K/Akt
10.  Osteogenic differentiation of amniotic epithelial cells: synergism of pulsed electromagnetic field and biochemical stimuli 
Pulsed electromagnetic field (PEMF) is a non-invasive physical therapy used in the treatment of fracture nonunion or delayed healing. PEMF can facilitate the osteogenic differentiation of bone marrow mesenchymal stem cells in vitro. Amniotic epithelial cells (AECs) have been proposed as a potential source of stem cells for cell therapy. However, whether PEMF could modulate the osteogenic differentiation of AECs is unknown. In the present study, the effects of PEMF on the osteogenic differentiation of AECs were investigated.
AECs were isolated from amniotic membrane of human placenta by trypsin digestion and were induced by PEMF and/or osteo-induction medium. After 21 days we used real time RT-PCR and immunocytochemistry to study the expression of osteoblast markers. The signal transduction of osteogenesis was further investigated.
The PEMF stimulation, or osteo-induction medium alone could induce osteogenic differentiation of AECs, as shown by expression of osteoblast specific genes and proteins including alkaline phosphatase and osteocalcin. Furthermore, a combination of PEMF and osteo-induction medium had synergy effects on osteogenic differentiation. In our study, the gene expression of BMP-2, Runx2, β-catenin, Nrf2, Keap1 and integrinβ1 were up-regulated in the osteogenic differentiation of AECs induced by PEMF and/or osteo-induction medium.
Combined application of PEMF and osteo-induction medium is synergistic for the osteogenic differentiation of AECs. It might be a novel approach in the bone regenerative medicine.
PMCID: PMC4267405  PMID: 25112311
Amniotic epithelial cells; Osteogenic differentiation; Pulsed electromagnetic field; BMP-2; Wnt/β-catenin signaling; Reactive oxygen species; Integrinβ1
11.  18F-fluorodeoxyglucose positron emission tomography/computed tomography findings of gastric lymphoma: Comparisons with gastric cancer 
Oncology Letters  2014;8(4):1757-1764.
The role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in numerous malignant tumors, including gastric lymphoma, is well-established. However, there have been few studies with regard to the 18F-FDG PET/CT features of gastric lymphoma. The aim of the present study was to characterize the 18F-FDG PET/CT features of gastric lymphoma, which were compared with those of gastric cancer. Prior to treatment, 18F-FDG PET/CT was performed on 24 patients with gastric lymphoma and 43 patients with gastric cancer. The 18F-FDG PET/CT pattern of gastric wall lesions was classified as one of three types: Type I, diffuse thickening of the gastric wall with increased FDG uptake infiltrating more than one-third of the total stomach; type II, segmental thickening of the gastric wall with elevated FDG uptake involving less than one-third of the total stomach; and type III, local thickening of the gastric wall with focal FDG uptake. The incidence of the involvement of more than one region of the stomach was higher in the patients with gastric lymphoma than in those with gastric cancer. Gastric FDG uptake was demonstrated in 23 of the 24 patients (95.8%) with gastric lymphoma and in 40 of the 43 patients (93.0%) with gastric cancer. Gastric lymphoma predominantly presented with type I and II lesions, whereas gastric cancer mainly presented with type II and III lesions. The maximal thickness was larger and the maximal standard uptake value (SUVmax) was higher in the patients with gastric lymphoma compared with those with gastric cancer. A positive correlation between the maximal thickness and SUVmax was confirmed for the gastric cancer lesions, but not for the gastric lymphoma lesions. There was no difference in the maximal thickness and SUVmax of the gastric wall lesions between the patients without and with extragastric involvement, for gastric lymphoma and gastric cancer. Overall, certain differences exist in the findings between gastric lymphoma and gastric cancer patients on 18F-FDG PET/CT images, which may contribute to the identification of gastric lymphoma.
PMCID: PMC4156241  PMID: 25202405
positron emission tomography; computed tomography; gastric lymphoma; gastric cancer
12.  Immunogenicity and safety of three 2010–2011 seasonal trivalent influenza vaccines in Chinese toddlers, children and older adults 
Human Vaccines & Immunotherapeutics  2013;9(8):1725-1734.
The 2009 influenza A(H1N1) pandemic strain was for the first time included in the 2010–2011 seasonal trivalent influenza vaccine (TIV). We conducted a double-blind, randomized trial in Chinese population to assess the immunogenicity and safety of the 2010–2011 TIV manufactured by GlaxoSmithKline and compared it with the counterpart vaccines manufactured by Sanofi Pasteur and Sinovac Biotech. Healthy toddlers (6–36 mo), children (6–12 y) and older adults (≥60 y) with 300 participants in each age group were enrolled to randomly receive two doses (toddlers, 28 d apart) or one dose (children and older adults). The immunogenicity was assessed by hemagglutination-inhibition (HI) assay. The solicited injection-site and systemic adverse events (AEs) were collected within 7 d after vaccination. All the three TIVs were well-tolerated with 15.1% of participants reporting AEs, most of which were mild. No serious AEs and unusual AEs were reported. Fever and pain were the most common systemic and injection-site AEs, respectively. The three TIVs showed good immunogenicity. The seroprotection rates against both H1N1 and H3N2 strains were more than 87% in toddlers after two doses and more than 95% in children and more than 86% in older adults after one dose. The seroprotection rates against B strain were 68–71% in toddlers after two doses, 70–74% in children and 69–72% in older adults after one dose. In conclusion, the three 2010–2011 TIVs had good immunogenicity and safety in Chinese toddlers, children and older adults and were generally comparable in immunogenicity and reactogenicity.
PMCID: PMC3906273  PMID: 23896581
influenza; vaccine; seasonal trivalent influenza vaccine; influenza A (H1N1); immunogenicity; safety
13.  Essential role of BAF complex interacting with Pax6 in establishment of a core cross-regulatory neurogenic network 
Cell stem cell  2013;13(4):403-418.
The molecular mechanisms of neurogenic fate determination are of particular importance in light of the need to regenerate neurons. Here we define the mechanisms of installing neurogenic fate by the transcription factor Pax6 acting together with the Brg1-containing BAF chromatin remodeling complex. We show that Pax6 physically interacts with Brg1-containing BAF complex and genetic deletion of either Pax6 or Brg1, in the neural stem cells in the adult mouse subependymal zone results in a strikingly similar fate conversion from neuronal progenitors to glia. The Pax6-BAF complex drives neurogenesis by directly activating transcription factors Sox11, Nfib and Pou3f4, which form a cross-regulatory network that maintains neurogenic fate downstream of the Pax6-BAF complex in neuroblasts. Our work identifies a novel concept of stratification in neural fate commitment with a strikingly specific role of the Pax6-BAF complex in initiating a cross-regulatory network essential for maintenance of the neurogenic lineage in the adult brain.
PMCID: PMC4098720  PMID: 23933087
Chromatin; Fate determinants; Neurogenesis; Fate conversion
14.  Neuropeptide Y protects cerebral cortical neurons by regulating microglial immune function 
Neural Regeneration Research  2014;9(9):959-967.
Neuropeptide Y has been shown to inhibit the immunological activity of reactive microglia in the rat cerebral cortex, to reduce N-methyl-D-aspartate current (INMDA) in cortical neurons, and protect neurons. In this study, after primary cultured microglia from the cerebral cortex of rats were treated with lipopolysaccharide, interleukin-1β and tumor necrosis factor-α levels in the cell culture medium increased, and mRNA expression of these cytokines also increased. After primary cultured cortical neurons were incubated with the lipopolysaccharide-treated microglial conditioned medium, peak INMDA in neurons increased. These effects of lipopolysaccharide were suppressed by neuropeptide Y. After addition of the neuropeptide Y Y1 receptor antagonist BIBP3226, the effects of neuropeptide Y completely disappeared. These results suggest that neuropeptide Y prevents excessive production of interleukin-1β and tumor necrosis factor-α by inhibiting microglial reactivity. This reduces INMDA in rat cortical neurons, preventing excitotoxicity, thereby protecting neurons.
PMCID: PMC4146213  PMID: 25206918
nerve regeneration; microglia; immunological activity; neuropeptide Y; interleukin-1β; tumor necrosis factor-α; INMDA; neural regeneration
15.  Comparison of corneal flap thickness using a FS200 femtosecond laser and a moria SBK microkeratome 
To evaluate differences in flap thickness resulting from use of an Alcon Wavelight FS200 femtosecond laser and a MORIA SBK microkeratome when making a 110-µm-thick corneal flap and to identify the potential factors that affect corneal flap thickness.
A prospective case study was performed on 120 eyes of 60 patients who were divided into two groups for LASIK, each group consisting of 60 eyes (30 patients). The corneal flaps were created using an Alcon Wavelight FS200 femtosecond laser or a MORIA SBK microkeratome. The central corneal flap thickness was calculated by subtraction pachymetry. Age, central corneal thickness (CCT), spherical equivalent refraction, mean keratometry, and corneal diameter were recorded preoperatively for analysis.
Cutting of all flaps was easily performed without intraoperative complications. In the Alcon Wavelight FS200 femtosecond laser group, the mean right and left corneal flap thicknesses were 114.0±6.6 µm (range: 98-126) and 111.4±7.6 µm (range: 98-122), respectively. The difference (2.6±9.1 µm) in the corneal flap thickness between the right and left eyes was not significant (t=1.59, P=0.12). Stepwise regression analysis indicated that the resulting corneal flap thickness was unrelated to the patient's age, preoperative CCT, spherical equivalent refraction, mean keratometry, or corneal diameter. In the MORIA SBK microkeratome group, the mean right and left corneal flap thicknesses were 110.6±7.4 µm (range: 97-125 µm) and 108.2±6.1 µm (range: 78-123 µm), respectively. The difference in the corneal flap thickness between the right and left eyes (2.4±6.5µm) was not significant (t=2.039, P=0.0506). The corneal flap thickness was positively correlated with the preoperative CCT through stepwise regression analysis (r=0.297, P=0.021). The corneal flap thickness was not related to age, spherical equivalent refraction, mean keratometry, or corneal diameter. The corneal flap thickness was estimated using the following equation: Tflap=67.77+0.076 CCT (F=5.63, P=0.021).
Both the Alcon Wavelight FS200 femtosecond laser and the MORIA SBK microkeratome produced 110-µm-thick corneal flaps. The central corneal flap thickness was positively correlated with the preoperative CCT in MORIA SBK microkeratome surgery.
PMCID: PMC4003081  PMID: 24790869
corneal flap thickness; femtosecond laser; laser in situ keratomileusis; microkeratome
16.  Mechanism of oxidant-induced mistranslation by threonyl-tRNA synthetase 
Nucleic Acids Research  2014;42(10):6523-6531.
Aminoacyl-tRNA synthetases maintain the fidelity during protein synthesis by selective activation of cognate amino acids at the aminoacylation site and hydrolysis of misformed aminoacyl-tRNAs at the editing site. Threonyl-tRNA synthetase (ThrRS) misactivates serine and utilizes an editing site cysteine (C182 in Escherichia coli) to hydrolyze Ser-tRNAThr. Hydrogen peroxide oxidizes C182, leading to Ser-tRNAThr production and mistranslation of threonine codons as serine. The mechanism of C182 oxidation remains unclear. Here we used a chemical probe to demonstrate that C182 was oxidized to sulfenic acid by air, hydrogen peroxide and hypochlorite. Aminoacylation experiments in vitro showed that air oxidation increased the Ser-tRNAThr level in the presence of elongation factor Tu. C182 forms a putative metal binding site with three conserved histidine residues (H73, H77 and H186). We showed that H73 and H186, but not H77, were critical for activating C182 for oxidation. Addition of zinc or nickel ions inhibited C182 oxidation by hydrogen peroxide. These results led us to propose a model for C182 oxidation, which could serve as a paradigm for the poorly understood activation mechanisms of protein cysteine residues. Our work also suggests that bacteria may use ThrRS editing to sense the oxidant levels in the environment.
PMCID: PMC4041444  PMID: 24744241
17.  Increasing the cytotoxicity of doxorubicin in breast cancer MCF-7 cells with multidrug resistance using a mesoporous silica nanoparticle drug delivery system 
Resistance to cytotoxic chemotherapy is the main cause of therapeutic failure and death in women with breast cancer. Overexpression of various members of the superfamily of adenosine triphosphate binding cassette (ABC)-transporters has been shown to be associated with multidrug resistance (MDR) phenotype in breast cancer cells. MDR1 protein promotes the intracellular efflux of drugs. A novel approach to address cancer drug resistance is to take advantage of the ability of nanocarriers to sidestep drug resistance mechanisms by endosomal delivery of chemotherapeutic agents. Doxorubicin (DOX) is an anthracycline antibiotic commonly used in breast cancer chemotherapy and a substrate for ABC-mediated drug efflux. In the present study, we developed breast cancer MCF-7 cells with overexpression of MDR1 and designed mesoporous silica nanoparticles (MSNs) which were used as a drug delivery system. We tested the efficacy of DOX in the breast cancer cell line MCF-7/MDR1 and in a MCF-7/MDR1 xenograft nude mouse model using the MSNs drug delivery system. Our data show that drug resistance in the human breast cancer cell line MCF-7/MDR1 can be overcome by treatment with DOX encapsulated within mesoporous silica nanoparticles.
PMCID: PMC4014214  PMID: 24817930
Breast cancer; MSNs; MDR; drug delivery system
18.  rAAV/ABAD-DP-6His attenuates oxidative stress-induced injury of PC12 cells 
Neural Regeneration Research  2014;9(5):481-488.
Our previous studies have revealed that amyloid β (Aβ)-binding alcohol dehydrogenase (ABAD) decoy peptide antagonizes Aβ42-induced neurotoxicity. However, whether it improves oxidative stress injury remains unclear. In this study, a recombinant adenovirus constitutively secreting and expressing Aβ-ABAD decoy peptide (rAAV/ABAD-DP-6His) was successfully constructed. Our results showed that rAAV/ABAD-DP-6His increased superoxide dismutase activity in hydrogen peroxide-induced oxidative stress-mediated injury of PC12 cells. Moreover, rAAV/ABAD-DP-6His decreased malondialdehyde content, intracellular Ca2+ concentration, and the level of reactive oxygen species. rAAV/ABAD-DP-6His maintained the stability of the mitochondrial membrane potential. In addition, the ATP level remained constant, and apoptosis was reduced. Overall, the results indicate that rAAV/ABAD-DP-6His generates the fusion peptide, Aβ-ABAD decoy peptide, which effectively protects PC12 cells from oxidative stress injury induced by hydrogen peroxide, thus exerting neuroprotective effects.
PMCID: PMC4153500  PMID: 25206842
nerve regeneration; neurodegenerative disease; gene therapy; Alzheimer's disease; amyloid beta peptide; amyloid beta binding alcohol dehydrogenase; adeno-associated virus; hydrogen peroxide; oxidative stress; mitochondrial dysfunction; NSFC grant; neural regeneration
19.  DARPP-32 to quantify intracerebral hemorrhage-induced neuronal death in basal ganglia 
Translational stroke research  2012;4(1):130-134.
Quantification of acute brain injury in basal ganglia is essential for mechanistic and therapeutic studies in experimental intracerebral hemorrhage (ICH). Using conventional counting of degenerating cells based on morphological or immunohistochemical criteria, it is hard to define the boundary of the whole lesion area. Dopamine- and cAMP-regulated phosphoprotein, Mr 32 kDa (DARPP-32) is a cytosolic protein highly enriched in medium-sized spiny neurons of the striatum. We developed new methods for quantifying lesion area by detecting the difference of the DARPP-32 negative area and the hematoma clot, and by measuring DARPP-32 protein level for semi-qualification in rat model of ICH. We found that DARPP-32 negative area around hematoma was present at day-1, peaked at day-3, and decreased at day-14 after ICH, a time course paralleled by DARPP-32 Western blots. The DARPP-32 negative area matched well with the necrotic area determined using propidium iodide. Treatment with an iron chelator, deferoxamine, attenuated the ICH-induced reduction in DARPP-32 protein levels. These results suggest that DARPP-32 is a simple and quantifiable indicator of ICH-induced neuronal death in basal ganglia.
PMCID: PMC3610184  PMID: 23543809
DARPP-32; intracerebral hemorrhage; iron; neuronal death
20.  Olig2 Targets Chromatin Remodelers To Enhancers To Initiate Oligodendrocyte Differentiation 
Cell  2013;152(1-2):248-261.
Establishment of oligodendrocyte identity is crucial for subsequent events of myelination in the central nervous system (CNS). Here, we demonstrate that activation of ATP-dependent SWI/SNF chromatin-remodeling enzyme Smarca4/Brg1 at the differentiation onset is necessary and sufficient to initiate and promote oligodendrocyte lineage progression and maturation. Genome-wide multistage studies by ChIP-seq reveal that oligodendrocyte-lineage determination factor Olig2 functions as a pre-patterning factor to direct Smarca4/Brg1 to oligodendrocyte-specific enhancers. Recruitment of Smarca4/Brg1 to distinct subsets of myelination regulatory genes is developmentally regulated. Functional analyses of Smarca4/Brg1 and Olig2 co-occupancy relative to chromatin epigenetic marking uncover novel stage-specific cis-regulatory elements that predict sets of transcriptional regulators controlling oligodendrocyte differentiation. Together, our results demonstrate that regulation of the functional specificity and activity of a Smarca4/Brg1-dependent chromatin-remodeling complex by Olig2, coupled with transcriptionally-linked chromatin modifications, is critical to precisely initiate and establish the transcriptional program that promotes oligodendrocyte differentiation and subsequent myelination of the CNS.
PMCID: PMC3553550  PMID: 23332759
21.  Critical illness polyneuropathy and myopathy: a systematic review 
Neural Regeneration Research  2014;9(1):101-110.
Critical illness polyneuropathy and critical illness myopathy are frequent complications of severe illness that involve sensorimotor axons and skeletal muscles, respectively. Clinically, they manifest as limb and respiratory muscle weakness. Critical illness polyneuropathy/myopathy in isolation or combination increases intensive care unit morbidity via the inability or difficulty in weaning these patients off mechanical ventilation. Many patients continue to suffer from decreased exercise capacity and compromised quality of life for months to years after the acute event. Substantial progress has been made lately in the understanding of the pathophysiology of critical illness polyneuropathy and myopathy. Clinical and ancillary test results should be carefully interpreted to differentiate critical illness polyneuropathy/myopathy from similar weaknesses in this patient population. The present review is aimed at providing the latest knowledge concerning the pathophysiology of critical illness polyneuropathy/myopathy along with relevant clinical, diagnostic, differentiating, and treatment information for this debilitating neurological disease.
PMCID: PMC4146320  PMID: 25206749
nerve regeneration; neurodegenerative diseases; critical illness polyneuropathy; critical illness myopathy; intensive care unit; sepsis; multiple organ failure; Guillain-Barré syndrome; NSFC grant; neural regeneration
Translational neuroscience  2013;4(3):10.2478/s13380-013-0132-3.
Vertebrate brains share many features in common. Early in development, both the hindbrain and diencephalon are built similarly. Only later in time do differences in morphology occur. Factors that could potentially influence such changes include certain physiological properties of neurons. As an initial step to investigate this problem, embryonic Alligator brain neurons were cultured and calcium responses were characterized. The present report is the first to document culture of Alligator brain neurons in artificial cerebrospinal fluid (ACSF) as well as in standard mammalian tissue culture medium supplemented with growth factors. Alligator brain neuron cultures were viable for at least 1 week with unipolar neurites emerging by 24 hours. Employing Fura-2 AM, robust depolarization-induced calcium influx, was observed in these neurons. Using selective blockers of the voltage-gated calcium channels, the contributions of N-, P/Q-, R-, T-, and L-type channels in these neurons were assessed and their presence documented. Lastly, Alligator brain neurons were challenged with an excitotoxic stimulus (glutamate + glycine) where delayed calcium deregulation could be prevented by a classical NMDA receptor antagonist.
PMCID: PMC3832207  PMID: 24260711
Alligator; Calcium mobilization; Immunoblot; Neuronal culture; NMDA receptor; Voltage-gated calcium channels
23.  The Neuron-specific Chromatin Regulatory Subunit BAF53b is Necessary for Synaptic Plasticity and Memory 
Nature neuroscience  2013;16(5):552-561.
Recent exome sequencing studies have implicated polymorphic BAF complexes (mammalian SWI/SNF chromatin remodeling complexes) in several human intellectual disabilities and cognitive disorders. However, it is currently unknown how mutations in BAF complexes result in impaired cognitive function. Post mitotic neurons express a neuron specific assembly, nBAF, characterized by the neuron-specific subunit BAF53b. Mice harboring selective genetic manipulations of BAF53b have severe defects in longterm memory and long-lasting forms of hippocampal synaptic plasticity. We rescued memory impairments in BAF53b mutant mice by reintroducing BAF53b in the adult hippocampus, indicating a role for BAF53b beyond neuronal development. The defects in BAF53b mutant mice appear to derive from alterations in gene expression that produce abnormal postsynaptic components, such as spine structure and function, and ultimately lead to deficits in synaptic plasticity. Our studies provide new insight into the role of dominant mutations in subunits of BAF complexes in human intellectual and cognitive disorders.
PMCID: PMC3777648  PMID: 23525042
24.  A 60-year review on the changing epidemiology of measles in capital Beijing, China, 1951-2011 
BMC Public Health  2013;13:986.
China pledged to join the global effort to eliminate measles by 2012. To improve measles control strategy, the epidemic trend and population immunity of measles were investigated in 1951–2011 in Beijing.
The changing trend of measles since 1951 was described based on measles surveillance data from Beijing Centre of Disease Control and Prevention (CDC). The measles vaccination coverage and antibody level were assessed by routinely reported measles vaccination data and twenty-one sero-epidemiological surveys.
The incidence of measles has decreased significantly from 593.5/100,000 in 1951 (peaked at 2721.0/100,000 in 1955), to 0.5/100,000 in 2011 due to increasing vaccination coverage of 95%-99%. Incidence rebounded from 6.6/100,000 to 24.5/100,000 since 2005 and decreased after measles vaccine (MV) supplementary immunization activities (SIAs) in 2010. Measles antibody positive rate was 85%-95% in most of years since 1981. High-risk districts were spotted in Chaoyang, Fengtai and Changping districts in recent 15 years. Age-specific incidence and proportion of measles varied over time. The most affected population were younger children of 1–4 years before 1978, older children of 5–14 years in 1978–1996, infant of <1 years and adults of ≥15 years in period of aim to measles elimination.
Strategies at different stages had a prevailing effect on the epidemic dynamics of measles in recent 60 years in Beijing. It will be essential to validate reported vaccination coverage, improve vaccination coverage in adults and strengthen measles surveillance in the anticipated elimination campaign for measles.
PMCID: PMC4016557  PMID: 24143899
Measles; Epidemiology; Incidence; Vaccine; Coverage; Sero-epidemiology
25.  Antitumor efficacy of a recombinant adenovirus encoding endostatin combined with an E1B55KD-deficient adenovirus in gastric cancer cells 
Gene therapy using a recombinant adenovirus (Ad) encoding secretory human endostatin (Ad-Endo) has been demonstrated to be a promising antiangiogenesis and antitumor strategy of in animal models and clinical trials. The E1B55KD-deficient Ad dl1520 was also found to replicate selectively in and destroy cancer cells. In this study, we aimed to investigate the antitumor effects of antiangiogenic agent Ad-Endo combined with the oncolytic Ad dl1520 on gastric cancer (GC) in vitro and in vivo and determine the mechanisms of these effects.
The Ad DNA copy number was determined by real-time PCR, and gene expression was assessed by ELISA, Western blotting or immunohistochemistry. The anti-proliferation effect (cytotoxicity) of Ad was assessed using the colorimetry-based MTT cell viability assay. The antitumor effects were evaluated in BALB/c nude mice carrying SGC-7901 GC xenografts. The microvessel density and Ad replication in tumor tissue were evaluated by checking the expression of CD34 and hexon proteins, respectively.
dl1520 replicated selectively in GC cells harboring an abnormal p53 pathway, including p53 mutation and the loss of p14ARF expression, but did not in normal epithelial cells. In cultured GC cells, dl1520 rescued Ad-Endo replication, and dramatically promoted endostatin expression by Ad-Endo in a dose- and time-dependent manner. In turn, the addition of Ad-Endo enhanced the inhibitory effect of dl1520 on the proliferation of GC cells. The transgenic expression of Ad5 E1A and E1B19K simulated the rescue effect of dl1520 supporting Ad-Endo replication in GC cells. In the nude mouse xenograft model, the combined treatment with dl1520 and Ad-Endo significantly inhibited tumor angiogenesis and the growth of GC xenografts through the increased endostatin expression and oncolytic effects.
Ad-Endo combined with dl1520 has more antitumor efficacy against GC than Ad-Endo or dl1520 alone. These findings indicate that the combination of Ad-mediated antiangiogenic gene therapy and oncolytic Ad therapeutics could be one of promising comprehensive treatment strategies for GC.
PMCID: PMC3853970  PMID: 24124726
Endostatin; Adenovirus (Ad) vector; Oncolytic adenovirus (Ad); Viral-gene therapy; Gastric cancer

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