Decellularized aorta of fetal pigs as a potential scaffold for small diameter tissue engineered vascular graft

Background For cardiovascular tissue engineering, acellularized biomaterials from pig have been widely investigated. Our purpose was to study mechanical properties and biocompatibility of decellularized aorta of fetal pigs （DAFP） to determine its potential as scaffold for small diameter tissue engineered vascular graft. Methods Descending aorta of fetal pigs was removed cells using trypsin, ribonuclease and desoxyribonuclease. Mechanical properties of DAFP were evaluated by tensile stress-strain and burst pressure analysis. Assessment of cell adhesion and compatibility was conducted by seeding porcine aortic endothelial cells. To evaluate biocompatibility in vivo DAFP was implanted subcutaneously into adult male Sprague Dawley rats for 2, 4 and 8 weeks. Results Histochemistry and scanning electron microscopy examination of DAFP revealed well-preserved extracellular matrix proteins and porous three-dimensional structures. Compared with fresh aorta, DAFP had similar ultimate tensile strength, axial compliance and burst pressure. Cell culture studies in vitro showed that porcine aortic endothelial cells adhered and proliferated on the surfaces of DAFP with excellent cell viability. Subdermal implantation demonstrated that the DAFP did not show almost any immunological reaction and exhibited minimal calcification during the whole follow-up period. Conclusion The DAFP has the potential to serve as scaffolds for small diameter tissue engineered vascular graft.     

BMP10 inhibited the growth and migration of gastric cancer cells

Tumor Biology - Bone morphogenetic protein 10 (BMP10), a novel member of BMP family, has been identified as an important regulator for angiogenesis. Dysregulation of BMP has been observed in...     

Therapeutic RNA silencing of Cys-X3-Cys chemokine ligand 1 gene prevents mice from adenovirus vector-induced acute liver injury

Gene therapy using adenovirus vectors may induce acute liver injury. Tissue injury induced by an adenovirus is likely associated with elevated expression of the Cys-X3-Cys chemokine ligand 1 (CX(3)CL1)/fractalkine (FKN) protein at the site of inflammation. However, the extent to which the actions of FKN contribute to liver injury remains unclear. We induced acute liver injury in mice by a hydrodynamics-based injection of adenovirus vector, which was confirmed to depend on the presence of natural killer (NK) cells and NK-dependent interferon-gamma (IFN-gamma). When the transferred adenovirus vector was inserted with the FKN gene, the severity of liver injury increased with much more Cys-X3-Cys chemokine receptor 1 (CX(3)CR1)-positive NK cell recruitment into the liver because of exogenous overproduction of FKN protein. Moreover, when production of endogenous FKN protein was silenced by inserting FKN-small interfering RNA into the adenovirus vector or was neutralized by an FKN-specific antibody, the adenovirus-induced acute severe liver injury was notably prevented with much lower hepatic NK cell infiltration and a significant reduction in the serum levels of IFN-gamma. CONCLUSION: Our findings suggest a strategy to prevent or alleviate adenovirus vector-induced acute liver injury by blocking FKN-CX(3)CR1 interaction in adenovirus vector-based gene therapy.     

Bayesian hierarchical modeling of receptor occupancy in PET trials

Receptor occupancy (RO) PET is a non-invasive way to determine drug on target. Given the complexity of procedures, long acquisition times, and high cost, ligand displacement imaging trials often have a limited size and produce sparse RO results over the time course of the blocking drug. To take the best advantage of the available data, we propose a Bayesian hierarchical model to analyze RO as a function of the displacing drug. The model has three components: the first estimates RO using brain regional time-radioactivity concentrations, the second shapes the pharmacokinetic profile of the blocking drug, and the last relates PK to RO. Compared to standard 2-steps RO estimation methods, our Bayesian approach quantifies the variability of the individual RO measures. The model has also useful prediction capabilities: to quantify brain RO for dosage regimens of the drug that were not tested in the experiment. This permits the optimal dose selection of neuroscience drugs at a limited cost. We illustrate the method in the prediction of RO after multiple dosing from a single-dose trial.     

Radon-induced proteomic profile of lung tissue in rats

The aim of this study was to investigate the differential expression of proteins in lung of rats following long-term exposure to radon. The total proteins of lung tissue from Wistar rats exposed to radon for cumulative doses up to 100, 200, or 400 WLM (working level months) were isolated by two-dimensional electrophoresis (2-DE) and analyzed with ImageMaster 2D Platinum software. Comparison of the 2-DE images between the control and radon-exposed groups resulted in 14 upregulated and 9 downregulated protein spots, of which 15 were identified by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) or matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry (MALDI-TOF/TOF-MS). The simultaneous up-expressions of RAGE and S100A6 indicated that both proteins might be applied as biomarkers for lung injury induced by long-term radon exposure.     

Different roles of IL-15 from IL-2 in differentiation and activation of human CD3+CD56+ NKT-like cells from cord blood in long term culture

The abundantly available source of stem cells and the low incidence of graft-versus-host disease (GVHD) made cord blood an attractive alternative source of hematopoietic stem cells for transplantation. Besides T cell and NK cell, NKT cell played an important role in low incidence of GVHD during allogeneic transplantation. IL-2 and IL-15 can stimulate T cell and NK cell proliferation, survival and activation in vitro. But they exhibited different effects on the GVHD during allogeneic transplantation. In this study, we explored the different effects of exogenous IL-2 and IL-15 on the expansion of CD3+CD56+ NKT-like cells by in vitro long term culture of cord blood mononuclear cells (CBMCs). The results showed that CD3+CD56+ NKT-like cells were derived from CD34-CD56- CBMCs and IL-2 improved CD3+CD56+ NKT-like cell expansion more strongly than IL-15. Interestingly, CD3+CD56+ NKT-like cells from IL-15-cocultured CBMCs had significantly lower apoptotic frequency and higher levels of activation markers (CD161, CD25, and IFN-gamma) than those from IL-2-cocultured CBMCs. The anti-apoptotic and activating effects of IL-15 on CD3+CD56+ NKT-like cells from CBMCs might possibly explain the pathogenic role of IL-15 in GVHD during allogeneic transplantation.     

Lyophilized Cheliensisin A submicron emulsion for intravenous injection: characterization, in vitro and in vivo antitumor effect

Growing attentions have been focused on natural antitumor drugs. Recently, a novel and potent antitumor drug Cheliensisin A (GC-51) with broad-spectrum efficiency has been developed. However, due to its poor water solubility and chemical instability, choosing the appropriate dosage form is of great significance. This study aimed at developing a lyophilized submicron emulsion for GC-51 and further improving the therapeutic index of the drug. The resultant lyophilized GC-51 submicron emulsion was much more stable than its solution, which can be stored for years without significant change on physicochemical properties. And its solubility was increased from 6.74 ± 0.14 to 2.00 ± 0.10 mg mL⁻¹. The 50% inhibitory concentration IC₅₀ values were calculated from growth curves by MTT assay on various tumor cell lines. Compared with the IC₅₀ of GC-51 crude drug, that of lyophilized GC-51 submicron emulsion decreased from 24.04 ± 1.97 to 8.23 ± 1.84 μg mL⁻¹ on HepG2, and from 31.08 ± 2.56 to 10.85 ± 2.09 μg mL⁻¹ on CT-26, from 17.90 ± 1.83 to 7.49 ± 1.87 μg mL⁻¹ on HeLa and from 16.38 ± 2.41 to 10.13 ± 2.12 μg mL⁻¹ on A549, respectively. In the time-dependent assay of tumor cell viability, lyophilized GC-51 submicron emulsion exhibited significantly lower inhibition rate in the initial action times, but increased gradually afterwards. That means lyophilized submicron emulsion as the vector for GC-51 had some protective and delayed release effect. Further, the in vivo therapeutic efficacy was measured in pulmonary metastasis of colon cancer-bearing BALB/c mice model. An obvious enhanced antitumor activity was observed after administration of lyophilized GC-51 submicron emulsion (P < 0.05), which increased from 22.78 ± 3.5 to 41.42 ± 4.2% compared with GC-51 injection. And the life span of tumor-bearing mice in lyophilized GC-51 submicron emulsion group was significantly longer than that of the mice in GC-51 injection and normal saline groups. Compared with crude drug, the lyophilized GC-51 submicron emulsion showed a significantly higher antitumor efficiency both in vivo and in vitro, suggesting a potential application in tumor chemotherapy.     

Suppression of ClC-3 channel expression reduces migration of nasopharyngeal carcinoma cells

Recent studies suggest that chloride (Cl-) channels regulate tumor cell migration. In this report, we have used antisense oligonucleotides specific for ClC-3, the most likely molecular candidate for the volume-activated Cl- channel, to investigate the role of ClC-3 in the migration of nasopharyngeal carcinoma cells (CNE-2Z) in vitro. We found that suppression of ClC-3 expression inhibited the migration of CNE-2Z cells in a concentration-dependent manner. Whole-cell patch-clamp recordings and image analysis further demonstrated that ClC-3 suppression inhibited the volume-activated Cl- current (I(Cl,vol)) and regulatory volume decrease (RVD) of CNE-2Z cells. The expression of ClC-3 positively correlated with cell migration, I(Cl,vol) and RVD. These results strongly suggest that ClC-3 is a component or regulator of the volume-activated Cl- channel. ClC-3 may regulate CNE-2Z cell migration by modulating cell volume. ClC-3 may be a new target for cancer therapies.     

PEGylated nanostructured lipid carriers loaded with 10-hydroxycamptothecin: an efficient carrier with enhanced anti-tumour effects against lung cancer

Most drugs do not have the pharmacokinetic features required for optimal pulmonary delivery. In this study, we developed PEGylated nanostructured lipid carriers (PEG-NLCs) to improve the delivery of anti-tumour agents to lung tumours. PEG-40 NLCs modified with PEG-40 stearate (molecular weight 2000 Da), PEG-100 NLCs modified with PEG-100 stearate (molecular weight 5000 Da) and NLCs without PEG modification were prepared by melt-emulsification and homogenization, and were loaded with 10-hydroxycamptothecin (HCPT). They were investigated in terms of physiological characteristics, biodistribution, cellular uptake, and anti-tumour effect in-vivo. PEG-NLCs exhibited regular morphology, with a spherical shape. The particle size (measured by laser diffraction) was approximately 100 nm. Encapsulation in PEG-NLCs protected the active lactone form of HCPT compared with HCPT solution after incubation with plasma. In biodistribution studies, PEG-NLCs, especially PEG-40 NLCs, had longer circulation time and decreased uptake by the reticuloendothelial system (RES) compared with unmodified NLCs. PEG-NLCs accumulated in the lungs after i.v. injection in mice. PEG-NLCs showed enhanced cellular uptake by human lung adenocarcinoma epithelial A549 cells. In-vivo experiments indicated that PEG-NLCs loaded with HCPT have superior efficacy against A549 lung cancer compared with HCPT solution and NLCs. These results suggest that PEG-NLCs is a promising delivery system for HCPT in the treatment of lung cancer.