Objectives
Icariin, a prenylated flavonol glycoside isolated from traditional Chinese medicinal herb of the genus Epimedium, has been demonstrated to be a potential alternative therapy for ...osteoporosis, and its action mechanism so far has been mainly attributed to its phytoestrogenic property. As blood supply to bone is considerably reduced with ageing and by the menopause, we hypothesized that icariin treatment would reduce bone loss by preventing ischaemia‐induced hypoxic damages to bone.
Materials and methods
To investigate effects of icariin treatment on cultured rat calvarial osteoblasts exposed to hypoxic conditions (2% oxygen).
Results
Compared to normoxic control, cell viability decreased with time to 50% by 48 h in the hypoxic group, and icariin attenuated the reduction, dose dependently, with 10−6 and 10−5 m concentrations showing significant protective effects. Icariin also inhibited increase of lactate dehydrogenase activity in culture media. Measurements on oxidative stress, cell cycling and cell survival indicated that icariin protected osteoblasts by reducing production of reactive oxygen species and malondialdehyde, increasing superoxide dismutase activity, arresting the cell cycle and inhibiting apoptosis. Icariin also preserved osteogenic differentiation potential of the hypoxic cells in a dose‐dependent manner, compared to the hypoxia alone group, as revealed by increased levels of RUNX‐2, OSX and BMP‐2 gene expression, alkaline phosphatase activity, and formation of mineralized nodules.
Conclusions
Our results demonstrated that icariin attenuated oxidative stress and apoptosis and preserved viability and osteogenic potential of osteoblasts exposed to hypoxia in vitro, and suggested that its anti‐osteoporotic effect may be attributed to its anti‐hypoxic activity and phytoestrogenic properties.
Objective
Icaritin, one effective metabolite of Herba Epimedii-derived flavonoid icariin, has a strong osteogenic activity. However, its action mechanism remains unclear. Since primary cilia have ...been shown to play a pivotal role in regulating the osteogenesis, we hypothesized primary cilia are indispensable in mediating icaritin osteogenic effect.
Materials and methods
Primary rat calvarial osteoblasts were transfected with siRNA1 targeting intraflagellar transport protein 88 (IFT88), a protein required for ciliogenesis, to prevent formation of primary cilium and were treated with 10
−6
M icaritin.
Results
Alkaline phosphatase (ALP) activity was significantly increased after 3 days in cells transfected with scrambled siRNA control and treated by icaritin (SC+I group) compared to cells transfected with scrambled siRNA control only (SC group). ALP activity after IFT88 siRNA1 transfection and icaritin treatment (siRNA1+I group) was significantly lower than that of SC+I group. Formation of ALP positively stained colonies after 6 days, osteocalcin secretion after 9 days and formation of calcified nodules after 12 days displayed a similar tendency among the three groups. mRNA expression of osteogenesis-related genes ALP, BMP-2, COL1α, RUNX-2 and OSX after 24 h was significantly increased in SC+I group, but was not different with SC group in siRNA1+I group. Protein levels of BMP-2, COL1α, RUNX-2 and OSX after 48 h showed the similar tendency with gene expression.
Conclusion
Primary cilia are important in mediating icaritin-stimulated osteogenic differentiation and may be a novel target for pharmacological therapies for bone loss.
Toroidal dipole resonance can significantly reduce radiation loss of materials, potentially improving sensor sensitivity. Generally, toroidal dipole response is suppressed by electric and magnetic ...dipoles in natural materials, making it difficult to observe experimentally. However, as 2D metamaterials, metasurfaces can weaken the electric and magnetic dipole, enhancing toroidal dipole response. Here, we propose a new graphene-integrated toroidal resonance metasurface as an ultra-sensitive chemical sensor, capable of qualitative detection of chlorothalonil in the terahertz region, down to a detection limit of 100 pg/mL. Our results demonstrate graphene-integrated toroidal resonance metasurfaces as a promising basis for ultra-sensitive, qualitative detection in chemical and biological sensing.
To identify the association between the expression of lncRNA NEAT1 and clinicopathological characteristics of patients with HCC, and to explore the prognostic significance of lncRNA NEAT1 in ...predicting prognosis of HCC.
We retrospectively reviewed 86 patients with HCC (35 female, 51 male) managed in our institution between 2009 and 2014. The expression level of lncRNA NEAT1 was detected by real-time PCR. Prognostic factors were evaluated using Kaplan–Meier curves and Cox proportional hazards models.
For the entire cohort of 86 patients, we showed that the expression level of NEAT1 was significantly higher in HCC tissues compared with non-tumorous tissues and NEAT1 was increased obviously in the HCC cell lines including SMMC-7721, Huh-7 and Hep3B (P < 0.001). MTT assay showed that si-NEAT1 remarkably inhibited the cell proliferation in three HCC cell lines. Moreover, over-expression of lncRNA NEAT1 was closely related to liver cirrhosis (P = 0.026), microvascular invasion (MVI) (P = 0.023), and TNM stage (P = 0.017). After adjusting for competing risk factors, we identified that expression level of lncRNA NEAT1 was an independently risk factor associated with the prognosis of patients with HCC (P = 0.031).
In this study, we found NEAT1 expressed significantly higher in HCC tissues compared with non-tumorous tissues. Overexpression of lncRNA NEAT1 was an independently risk factor associated with the prognosis of patients with HCC.
This study focused on an endophytic bacterial strain, Pantoea sp. Sd‐1, which can be used to degrade lignin and rice straw. This strain was isolated from rice seeds by an optimized surface ...sterilization method. Pantoea sp. Sd‐1 showed exceptional ability to degrade rice straw and lignin. In rice straw or kraft lignin‐containing medium supplemented with 1% glucose and 0·5% peptone, Pantoea sp. Sd‐1 effectively reduced the rice straw mass weight by 54·5% after 6 days of treatment. The strain was also capable of reducing the lignin colour (52·4%) and content (69·1%) after 4 days of incubation. The findings suggested that the rice endophytic bacterium Pantoea sp. Sd‐1 could be applied for the degradation of lignocellulose biomass, such as rice straw. SIGNIFICANCE AND IMPACT OF THE STUDY: Rice straw, an abundant agricultural by‐product in China, is very difficult to degrade because of its high lignin content. Due to the immense environmental adaptability and biochemical versatility of bacteria, endophytic bacteria are useful resources for biodegradation. In this study, we screened for endophytic bacteria capable of biodegrading rice straw and lignin and obtained one strain, Pantoea sp. Sd‐1, with suitable characteristics. Sd‐1 could be used for degradation of rice straw and lignin, and may play an important role in biodegradation of this agricultural by‐product.
Ground-based observations have insufficient spatial coverage to assess long-term human exposure to fine particulate matter (PM2.5) at the global scale. Satellite remote sensing offers a promising ...approach to provide information on both short- and long-term exposure to PM2.5 at local-to-global scales, but there are limitations and outstanding questions about the accuracy and precision with which ground-level aerosol mass concentrations can be inferred from satellite remote sensing alone. A key source of uncertainty is the global distribution of the relationship between annual average PM2.5 and discontinuous satellite observations of columnar aerosol optical depth (AOD). We have initiated a global network of ground-level monitoring stations designed to evaluate and enhance satellite remote sensing estimates for application in health-effects research and risk assessment. This Surface PARTiculate mAtter Network (SPARTAN) includes a global federation of ground-level monitors of hourly PM2.5 situated primarily in highly populated regions and collocated with existing ground-based sun photometers that measure AOD. The instruments, a three-wavelength nephelometer and impaction filter sampler for both PM2.5 and PM10, are highly autonomous. Hourly PM2.5 concentrations are inferred from the combination of weighed filters and nephelometer data. Data from existing networks were used to develop and evaluate network sampling characteristics. SPARTAN filters are analyzed for mass, black carbon, water-soluble ions, and metals. These measurements provide, in a variety of regions around the world, the key data required to evaluate and enhance satellite-based PM2.5 estimates used for assessing the health effects of aerosols. Mean PM2.5 concentrations across sites vary by more than 1 order of magnitude. Our initial measurements indicate that the ratio of AOD to ground-level PM2.5 is driven temporally and spatially by the vertical profile in aerosol scattering. Spatially this ratio is also strongly influenced by the mass scattering efficiency.
This paper reports the crystal structures of two
n
-tetrabutylammonium inclusion compounds of 2,2'-bis(4-hydroxyphenyl)propane (BPA) of (
n
-C
4
H
9
)
4
N
+
⋅C
15
H
15
O
⋅3C
15
H
16
O
2
⋅C
2
H
5
OH (
...1
) and 2(
n
-C
4
H
9
)
4
N
+
⋅C
2
O
⋅2C
15
H
16
O
2
(
2
), which were characterized by single crystal X-ray diffraction. The experimental data show that
1
can be classified to be the triclinic crystal system of
P
space group and
2
to be the orthorhombic system of
Pna
2
1
with higher symmetry. Interestingly, the crystal structures of the two inclusion compounds have the same point during the formation of the related structures. In these two crystals with varied symmetry, BPA molecules or ions and the bridging auxiliary molecules first form a separate hydrogen bond unit, then the hydrogen-bonded units pack to form the three-dimensional host framework by different symmetry operations. And finally the guest tetrabutylammonium cations are arranged between the varied voids of the host skeleton to yield the stable crystalline structures.
Milk proteins can be used as encapsulation walls to increase the bioavailability of active compounds because they can bind hydrophobic, hydrophilic, and charged compounds. The objective of this study ...was to investigate the effects of astaxanthin (ASTA) encapsulation and the functional properties of milk protein and ASTA nanocomposites by an ultrasound-assisted pH-shifting treatment of different milk proteins, including milk protein concentrate (MPC), micellar casein (MCC), and whey protein isolate (WPI). The ultrasound-assisted pH-shifting treatment of milk protein helped to improve the encapsulation rate of ASTA. Therein, MCC showed great improvement of encapsulating ASTA after co-treatment with the raised encapsulated rate of 5.11%, followed by WPI and MPC. Furthermore, the nanocomposites of ASTA with milk protein exhibit improved bioavailability, antioxidant capacity, and storage stability. By comparison, MCC-encapsulated ASTA has the best storage stability, followed by MPC, and WPI-encapsulated ASTA has the least stability over a 28-d storage period. The results of intrinsic fluorescence and surface hydrophobicity showed that milk protein underwent fluorescence quenching after binding to ASTA, which was due to the hydrophobic sites of the protein being occupied by ASTA. In general, the nanocomposites of milk protein and ASTA fabricated by using an ultrasound-assisted pH-shifting treatment have the potential to be better nano-delivery systems for ASTA in functional foods, especially MCC, which showed excellent performance in encapsulation after treatment technique.
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Ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) is the main source of extracellular pyrophosphate. Along with tissue-nonspecific alkaline phosphatase (TNAP), ENPP1 plays an important role ...in balancing bone mineralisation. Although well established in pre-osteoblasts, the regulating mechanisms of ENPP1 in osteoblasts and osteocytes remain largely unknown. Using bioinformatic methods, osterix (Osx), an essential transcription factor in osteoblast differentiation and osteocyte function, was found to have five predicted binding sites on the ENPP1 promoter. ENPP1 and Osx showed a similar expression profile both in vitro and in vivo. Over-expression of Osx in MC3T3-E1 and MLO-Y4 cells significantly up-regulated the expression of ENPP1 (p < 0.05). The consensus Sp1 sequences, located in the proximal ENPP1 promoter, were identified as Osx-regulating sites using promoter truncation experiments and chromatin immunoprecipitation (ChIP) assays. The p38-mitogen-activated protein kinase (MAPK) signalling pathway was demonstrated to be responsible for ENPP1 promoter activation by Osx. Runt-related transcription factor 2 (Runx2) was confirmed to have synergistic effects with Osx in activating ENPP1 promoter. Taken together, these results provided evidence of the regulating mechanisms of ENPP1 transcription in osteoblasts and osteocytes.
Research has shown that the incidence of prostate cancer is increased in patients with type 2 diabetes mellitus (T2DM) 1. Glucagon-like peptide-1 (GLP-1) is a gastrointestinal hormone that enhances ...glucose-dependent insulin secretion and suppresses glucagon release.
Here, we examined the effect of exenatide and liraglutide, 2 types of GLP-1 analogues, on prostate cancer cells growth by CCK-8 assay, Hoechst33258 staining assay, and western blot analysis of apoptosis-related proteins Bax and Bcl-2. Also the kinase pathways maybe involved and the expression of GLP-1 receptor (GLP-1 R) in LNCap cells was detected.
In our experiments, exenatide and liraglutide significantly inhibited the proliferation of the LNCap cell lines and induced the cell apoptosis. Exenatide (1-100 nmol/L) increased the ratio of Bax/Bcl-2 in a dose-dependent manner, whereas liraglutide increased Bax/Bcl-2 ratio only at concentrations of 10 nmol/L. And we found that GLP-1 analogues activate p38 but not ERK1/2 or AKT in LNCap cells. And classical GLP-1 receptor was detected in LNCap cells.
These data suggest that exenatide and liraglutide attenuate prostate cancer growth through regulating P38 pathway by binding with GLP-1R.
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