Time-dependent effects of sclerostin antibody on a mouse fracture healing model

OBJECTIVES

Treatment with Sclerostin antibody (Scl-Ab) has shown to enhance fracture healing in rodent and non-human primate models. The current study investigated the time-dependent changes during Scl-Ab treatment in a mouse osteotomy model.

METHODS

1 day after osteotomy, C57BL mice received subcutaneous injection with vehicle or Scl-Ab at 25 mg/kg, twice/week for 2, 4, or 6 weeks. 20 mice from each group were necropsied at weeks 2, 4, and 6 for Micro-CT, histomorphmetry and mechanical testing examinations.

RESULTS

The bone mineral apposition rate at fracture callus was significantly higher in the Scl-Ab treated groups at all the time points. Micro-CT analysis showed that the volumetric bone mineral density (vBMD) and bone volume over tissue volume (BV/TV) in the Scl-Ab treated groups at 4 and 6 weeks were significantly greater than that of vehicle control groups. Mechanical testing showed that the maximum load of failure at the fracture callus increased significantly by 68% at 6 weeks in the Scl-Ab treated groups.

CONCLUSIONS

This study confirmed that mice treated with Scl-Ab increased bone formation from 2 weeks, bone mineral density and bone volume at 4 weeks, followed by significant increase in bone strength at the fracture site at 6 weeks. These results suggest that applying sclerostin antibody at early stage fracture healing promotes fracture healing.

Tuning of uniaxial magnetic anisotropy in amorphous CoFeB films

We demonstrate that the uniaxial magnetic anisotropy (UMA) of amorphous CoFeB films can be tuned by crystallinity and orbital moment ratio, combining the results of magnetization reversal and ferromagnetic resonance with high-resolution transmission electron microscopy, x-ray-absorption near-edge structure and x-ray magnetic circular dichroism. Isotropic polycrystalline buffers of tungsten (W), tantalum (Ta), and copper (Cu) between CoFeB and Si(100) substrates have direct and crucial bearing on the interfacial microstructure and orbital moment ratio. Compared with Ta and Cu buffer, CoFeB with W buffer exhibits obvious UMA and has lower crystallinity at the interface and higher orbital moment. Amorphous phase distributed homogeneously in CoFeB film grown on W buffer contributes to improve the easy-axis squareness with a sharp magnetization reversal. Our demonstrations not only realize effective tuning of UMA in amorphous CoFeB, but also provide an appealing alternative buffer (W) for CoFeB-based magnetic tunnel junctions.

Characterization of chicken visfatin gene: cDNA cloning, tissue distribution, and promoter analysis

Here we report the cloning and characterization of chicken visfatin (also called pre-B cell enhancing factor; PBEF, or nicotinamide phosphoribosyltransferase; Nampt) gene. Sequence analyses revealed that the coding region of visfatin is 1,482 bp in length and encodes a protein of 493 amino acids, which shares high amino acid sequence identity not only to visfatin of human (94%), rat (94%), carp (89%), and zebrafish (89%), but also to Nampt of sponge (58%) and cyanobacterium (48%). The reverse transcription PCR assay and Northern-blot analysis demonstrated that visfatin was widely expressed in all chicken tissues examined. Using a dual luciferase reporter system, we further demonstrated that the cloned 1,372-bp fragment upstream of the putative translation start site (ATG) displayed the maximal promoter activity in cultured CHO, DF-1, and HEK293 cells, whereas the removal of its 5'-region (1,075 bp) or 3'-region (297 bp) could only partially reduce its promoter activity, implying that visfatin gene transcription was likely controlled by multiple promoters near the translation start site. Taken together, results from present study will contribute to our better understanding of the expression and roles of visfatin gene in chickens.

Suppression of hepatocarcinoma model in vitro and in vivo by ECRG2 delivery using adenoviral vector

Hepatocarcinoma represents one of the most malignant cancer types. Esophageal cancer-related gene 2 (ECRG2) is found to be critical in the process of carcinogenesis. It regulates urokinase-type plasmin activator receptor and extracellular matrix function and its polymorphism in exon 4 is associated with cancer relapse. To explore new strategies to fight against cancer, here we first systematically evaluated the therapeutic potential as a biological tool using adenoviral vector (Ad-ECRG2). Ad-ECRG2 is exogenously expressed in cytoplasm and is potent to suppress the growth of cancer cell by inducing apoptosis as effective as Ad-p53. Ad-ECRG2 is able to suppress the invasion and adhesion of cancer cells at low titers. It alters the expression of a panel of cancer-related molecules, including nuclear factor-kB, matrix metalloproteinase 2 and E-cadherin, contributing to reverse malignancy phenotype of cancer cells. In vivo experiments show a significant inhibition of cancer growth by intratumoral Ad-ECRG2 administration. No evident toxicity was observed in the model animal during the study. We concluded that ECRG2 is a potential molecular target in biological therapy strategies for cancer treatment.

Further studies on the use of a polymerase chain reaction test for the diagnosis of infectious coryza

Further information is reported on the use of a polymerase chain reaction (PCR) test for the diagnosis of infectious coryza in China. The majority of sinus swabs taken from artificially infected chickens and stored in glycerol-enriched phosphate-buffered saline were still positive by PCR after storage for 180 days at either 4 degrees C or - 20 degrees C. Storage of swabs in either saline or nutrient broth was not as effective. Traditional culture failed to detect H. paragallinarum after storage for 3 days, regardless of storage medium or storage temperature. With dry swabs, the PCR could detect H. paragallinarum after storage for 7 days or longer at either 4 degrees C or - 20 degrees C, while traditional culture could not. In PCR tests on 64 artificially-challenged chickens, all were positive by PCR at the six sampling dates up to 18 days post-challenge. Traditional culture gave a similar result. Both PCR and culture detected 50% or less of chickens as positive at 21 and 24 days post challenge. Antibiotic treatment reduced the ability of both culture and the PCR test to detect H. paragallinarum. The value of the PCR test and its superiority over traditional culture for the diagnosis of infectious coryza has been confirmed in these experiments.

Room-temperature perpendicular exchange coupling and tunneling anisotropic magnetoresistance in an antiferromagnet-based tunnel junction

We investigate the exchange coupling between perpendicular anisotropy (PMA) Co/Pt and IrMn in-plane antiferromagnets (AFMs), as well as tunneling anisotropic magnetoresistance (TAMR) in [Pt/Co]/IrMn/AlO_{x}/Pt tunnel junctions, where Co/Pt magnetization drives rotation of AFM moments with the formation of exchange-spring twisting. When coupled with a PMA ferromagnet, the AFM moments partially rotate with out-of-plane magnetic fields, in contrast with being pinned along the easy direction of IrMn for in-plane fields. Because of the superior thermal tolerance of perpendicular exchange coupling and the stability of moments in ~6 nm-thick IrMn, TAMR gets significantly enhanced up to room temperature. Their use would advance the process towards practical AFM spintronics.

Multicenter phase II study of sunitinib in patients with non-clear cell renal cell carcinoma

BACKGROUND

Retrospective and molecular biologic data suggest that sunitinib may be effective in patients with non-clear cell renal cell carcinoma (nccRCC).

PATIENTS AND METHODS

Eligibility criteria included advanced nccRCC except for collecting duct carcinoma and sarcomatoid carcinoma without identifiable renal cell carcinoma subtypes. Patients were treated with 50 mg/day oral sunitinib for 4 weeks, followed by 2 weeks of rest. The primary end point was overall response rate (RR).

RESULTS

Thirty-one eligible patients were enrolled. Twenty-four patients (77%) had prior nephrectomy. By Memorial Sloan-Kettering Cancer Center criteria, 8 patients (26%) had poor risk and 14 (45%) had intermediate risk. Twenty-two patients had papillary renal cell carcinoma (RCC), and three had chromophobe RCC. Eleven patients had partial response with a RR of 36% (95% confidence interval (CI) 19% to 52%) and an additional 17 patients (55%) had stable disease. Median duration of response was 12.7 months (95% CI 6.3-19.1 months), and median progression-free survival was 6.4 months (95% CI 4.2-8.6 months). At a median follow-up duration of 18.7 months (95% CI 13.7-23.7 months), 13 patients (42%) had died, resulting in an estimated median survival of 25.6 months (95% CI 8.4-42.9 months). Toxicity profiles were commensurate with prior reports.

CONCLUSIONS

Sunitinib has promising activity in patients with nccRCC (NCT01219751).

Alveolar macrophage-derived vascular endothelial growth factor contributes to allergic airway inflammation in a mouse asthma model

Vascular endothelial growth factor (VEGF) is a potent proangiogenic factor that correlates with vascular permeability and remodelling in asthma. Recently, alveolar macrophages (AM) were shown to be an important source of VEGF during lung injury. Our previous studies demonstrated that AM are an important subset of macrophages in the initiation of asthmatic symptoms. Here, we further investigated whether AM-derived VEGF was required for allergic airway inflammation in asthma. In this study, we reported that the expression of VEGF in AM was significantly increased after allergen challenge. Depleting AM or neutralizing VEGF in alveolus prevented ovalbumin (OVA)-induced asthma-related inflammation by inhibiting the infiltration of inflammatory cells in the lung, reduced the level of the cytokines, IL-4, IL-5, and IL-13, in the bronchoalveolar lavage fluid (BALF) and decreased airway hyperresponsiveness (AHR). Moreover, the inhibition of miR-20b increased the protein level of VEGF in normal AM; conversely, increasing miR-20b in asthmatic AM resulted in decreased VEGF protein levels. These findings suggest that AM-derived VEGF is necessary for allergic airway inflammation in asthmatic mice and miR-20b negatively regulates this expression.

IL-12 and IL-10 production are differentially regulated by phosphatidylinositol 3-kinase in mast cells

The cellular mechanisms that directly regulate the production of pro- and anti-inflammatory cytokines after lipopolysaccharide (LPS) stimulation in mast cells are currently unresolved. The aim of this study was to clarify the role of phosphatidylinositol 3-kinase (PI3K) in the production of IL-12 and IL-10 in mouse bone marrow-derived mast cells (BMMCs), stimulated with Escherichia coli-derived LPS. LPS activates the PI3K signalling pathway; analysis of cytokine production following LPS stimulation of BMMCs revealed that inhibition of the PI3K pathway differentially regulated IL-10 and IL-12 syntheses. IL-12 production was enhanced, whereas IL-10 levels were suppressed. Inhibition of LPS-mediated activation of the PI3K pathway resulted in a pronounced reduction of NF-κB activity that was dependent on IκBα phosphorylation. These findings demonstrate a regulatory function for PI3K in modulating IL-10 and IL-12 production in mast cells and provide insight into how engagement of the PI3K pathway affects the induction of key immunoregulatory cytokines that control both qualitative and quantitative aspects of early inflammation.

Preparation, characterization and in vivo evaluation of pH-sensitive oral insulin-loaded poly(lactic-co-glycolicacid) nanoparticles

AIM

Oral administration of insulin is a promising drug delivery system for diabetic patients as it is convenient and reduces pain, two of the major contributors to non-compliance.

METHODS

In this study, insulin was encapsulated in poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) by using double-emulsion/solvent evaporation technique and analyses on its release kinetics were carried out using both in vitro and in vivo methods.

RESULTS

First, only by this simple methods, release speed of insulin from NPs can be controlled in different pH solution. The rate of release of insulin was found to be slower in acidic pH; about 90% of insulin was released in 11 days at pH 1.0. In alkaline conditions, the release was faster; about 90% release was observed to occur within 3 days at pH 7.8. The insulin-loaded poly (lactic-co-glycolic acid) nanoparticles (PINPs) were administered orally to diabetes mellitus-induced rats and the response of blood glucose and insulin levels was estimated. Blood glucose decreased and the concentration of insulin in animal blood increased. In diabetic animals which were administered intermittent insulin, every 8 h, blood glucose levels were maintained equivalently with those of healthy rats.

CONCLUSION

These experimental results indicated that oral PINPs are able to deliver insulin effectively and decrease animal blood sugar; in conclusion, this may be a promising delivery system for the treatment of diabetes.

Origin of strong white electroluminescence from dense Si nanodots embedded in silicon nitride

Strong white electroluminescence (EL) from SiN-based devices containing Si nanodots with a density of more than 4.6×10(12)cm(2) was investigated. The white EL illustrates enhanced light emission with increasing applied voltage and can be divided into two components, a dominant peak at ~710 nm and weak one at ~550 nm, which are close to those of the PL spectra optically pumped by the 325 and 488 nm lines, respectively. Based on the PL characteristics, we propose that the dominant EL band arises from the band-to-band recombination in the dense Si nanodots where quantum confinement plays a decisive role in the light emission, whereas the weak EL band originates from the radiative Si dangling bond (K⁰) centers in the silicon nitride matrix.

A genome-wide survey of copy number variation regions in various chicken breeds by array comparative genomic hybridization method

The discovery of copy number variation (CNV) in the genome has provided new insight into genomic polymorphism. Studies with chickens have identified a number of large CNV segments using a 385k comparative genomic hybridization (CGH) chip (mean length >140 kb). We present a detailed CNV map for local Chinese chicken breeds and commercial chicken lines using an Agilent 400k array CGH platform with custom-designed probes. We identified a total of 130 copy number variation regions (CNVRs; mean length = 25.70 kb). Of these, 104 (80.0%) were novel segments reported for the first time in chickens. Among the 104 novel CNVRs, 56 (53.8%) of the segments were non-coding sequences, 65 (62.5%) showed the gain of DNA and 40 (38.5%) showed the loss of DNA (one locus showed both loss and gain). Overlapping with the formal selective sweep data and the quantitative trait loci data, we identified four loci that might be considered to be high-confidence selective segments that arose during the domestication of chickens. Compared with the CNVRs reported previously, genes for the positive regulation of phospholipase A2 activity were discovered to be significantly over-represented in the novel CNVRs reported here by gene ontology analysis. Availability of our results should facilitate further research in the study of the genetic variability in chicken breeds.

The mechanism of memory impairment induced by Aβ chronic administration involves imbalance between cytokines and neurotrophins in the rat hippocampus

It has been demonstrated that the onset and progression of Alzheimer's disease (AD) are associated with inflammatory disorders in the brain. Although the interactions of inflammatory cytokines with neurotrophins have been reported in vitro, the balance change between inflammatory cytokines and neurotrophic factors (NTFs), such as nerve growth factor (NGF), brain derived neurotrophic factor (BDNF), and glial cell line-derived neurotrophic factor (GDNF), due to amyloid β (Aβ) chronic administration in vivo is still unclear. The hypothesis of the present study was that the accumulation of Aβ activated glial cells to produce inflammatory mediators and NTFs to maintain the neurons survival, however the failure of crosstalk between NTFs and inflammatory cytokines might occur in the brain and the NTFs expressions would decrease after Aβ chronic treatment, which, therefore, would contribute to the neuronal death and memory impairments. Thus, the present study measured the learning and memory behavior, glial cells activities, cytokines (IL-1α, IL-1β and TNF-α) concentrations and NTFs (NGF, BDNF and GDNF) gene and protein levels in rats after i.c.v injection of Aβ(25-35) for 14 days. The results showed that Aβ (25-35)-treated animals exhibited failure of balance between inflammatory cytokines and NTFs system (increased cytokines levels, decreased NGF protein expression and reduced NTFs gene transcriptions), which might contribute to the cognitive impairments. The findings from this study provide valuable evidence that correct regulation of the crosstalk between inflammatory cytokines and NTFs could be a direction for AD therapy in the future.