Evaluation of endogenous control genes for gene expression studies across multiple tissues and in the specific sets of fat- and muscle-type samples of the pig

To normalize a set of quantitative real-time PCR (q-PCR) data, it is essential to determine an optimal number/set of housekeeping genes, as the abundance of housekeeping genes can vary across tissues or cells during different developmental stages, or even under certain environmental conditions. In this study, of the 20 commonly used endogenous control genes, 13, 18 and 17 genes exhibited credible stability in 56 different tissues, 10 types of adipose tissue and five types of muscle tissue, respectively. Our analysis clearly showed that three optimal housekeeping genes are adequate for an accurate normalization, which correlated well with the theoretical optimal number (r ≥ 0.94). In terms of economical and experimental feasibility, we recommend the use of the three most stable housekeeping genes for calculating the normalization factor. Based on our results, the three most stable housekeeping genes in all analysed samples (TOP2B, HSPCB and YWHAZ) are recommended for accurate normalization of q-PCR data. We also suggest that two different sets of housekeeping genes are appropriate for 10 types of adipose tissue (the HSPCB, ALDOA and GAPDH genes) and five types of muscle tissue (the TOP2B, HSPCB and YWHAZ genes), respectively. Our report will serve as a valuable reference for other studies aimed at measuring tissue-specific mRNA abundance in porcine samples.

The Study of Myogenin Expression in Denervated Human Skeletal Muscles

Skeletal muscle denervation eventually causes atrophy as a result of interrupted nerve conduction and the lack of nutritional factors. Myogenin is a myogenic regulatory factor that plays a key role in myoblast differentiation. Changes in myogenin expression in denervated rat skeletal muscle have been demonstrated, but myogenin expression in denervated human skeletal muscle has not been reported. Human muscle samples were analysed at different time-points post-denervation to evaluate changes in myogenin expression and their relationship with skeletal muscle atrophy. Post-denervation, myogenin mRNA levels peaked at 7 months and were 37.5 times the normal level. Expression levels then declined to 21 and 11 times the normal level at 12 and 26 months post-denervation, respectively. Prolonged denervation resulted in pathological changes characterized by decreased numbers of intact muscle fibres.

Maximizing efficiency and cost-effectiveness of Type 2 diabetes screening: the AusDiab study

AIMS

  To evaluate how to most efficiently screen populations to detect people at high risk of incident Type 2 diabetes and those with prevalent, but undiagnosed, Type 2 diabetes.

METHODS

  Data from 5814 adults in the Australian Diabetes, Obesity and Lifestyle study were used to examine four different types of screening strategies. The strategies incorporated various combinations of cut-points of fasting plasma glucose, the non-invasive Australian Type 2 Diabetes Risk Assessment Tool (AUSDRISK1) and a modified version of the tool incorporating fasting plasma glucose (AUSDRISK2). Sensitivity, specificity, positive predictive value, screening costs per case of incident or prevalent undiagnosed diabetes identified and intervention costs per case of diabetes prevented or reverted were compared.

RESULTS

  Of the four strategies that maximized sensitivity and specificity, use of the non-invasive AUSDRISK1, followed by AUSDRISK2 in those found to be at increased risk on AUSDRISK1, had the highest sensitivity (80.3%; 95% confidence interval 76.6-84.1%), specificity (78.1%; 95% confidence interval 76.9-79.2%) and positive predictive value (22.3%; 95% confidence interval 20.2-24.4%) for identifying people with either prevalent undiagnosed diabetes or future incident diabetes. It required the fewest people (24.1%; 95% confidence interval 23.0-25.2%) to enter lifestyle modification programmes, and also had the lowest intervention costs and combined costs of running screening and intervention programmes per case of diabetes prevented or reverted.

CONCLUSIONS

  Using a self-assessed diabetes risk score as an initial screening step, followed by a second risk score incorporating fasting plasma glucose, would maximize efficiency of identifying people with undiagnosed Type 2 diabetes and those at high risk of future diabetes.

The Krüppel-like factor 6 genotype is associated with gastric cancer in a Chinese population

Association of the IVS1 -27G/A polymorphism of Krüppel-like factor 6 (KLF6) with gastric cancer was examined in a Chinese population comprising 300 gastric cancer patients and 300 healthy controls. Single-nucleotide polymorphism analysis was performed by amplifying intron 1 of KLF6 and sequencing the products. The KLF6 genotype IVS1 -27AA was significantly less frequent in gastric cancer patients than in controls and significantly less frequent in patients with advanced (stage III/IV) gastric cancer than in those with early (stage I/II) cancer. Stratification by location, Lauren's classification and histological differentiation revealed no significant differences in genotype distribution. Thus, in this Chinese population the KLF6 IVS1 -27AA genotype was associated with a decreased risk of gastric cancer and with cancer stage. Further study is required to clarify the mechanisms involved and, potentially, to facilitate the design of effective clinical trials.

Optically directed assembly of continuous mesoscale filaments

We demonstrate irreversible continuous filament formation when a weak laser focus is positioned near the edge of an evaporating colloidal droplet containing carbon and gold nanoparticles. Optical trapping, hydrothermal, and chemical interactions lead to controlled colloidal synthesis of stable, irreversible mesoscale filaments of arbitrary shape and size. Mechanisms for this optically directed assembly are discussed with fluid dynamics, molecular dynamics, and lattice kinetic Monte Carlo calculations.

Glycogen synthase kinase-3β is a functional modulator of serotonin-1B receptors

Glycogen synthase kinase-3 (GSK3) is a constitutively active protein kinase that is involved in neuronal regulation and is a potential pharmacological target of neurological disorders. We found previously that GSK3β selectively interacts with 5-hydroxytryptamine-1B receptors (5-HT1BR) that have important functions in serotonin neurotransmission and behavior. In this study, we provide new information supporting the importance of GSK3β in 5-HT1BR-regulated signaling, physiological function, and behaviors. Using molecular, biochemical, pharmacological, and behavioral approaches, we tested 5-HT1BR's interaction with G(i)α(2) and β-arrestin2 and 5-HT1BR-regulated signaling in cells, serotonin release in mouse cerebral cortical slices, and behaviors in wild-type and β-arrestin2 knockout mice. Molecular ablation of GSK3β and GSK3 inhibitors abolished serotonin-induced change of 5-HT1BR coupling to G(i)α(2) and associated signaling but had no effect on serotonin-induced recruitment of β-arrestin2 to 5-HT1BR. This effect is specific for 5-HT1BR because GSK3 inhibitors did not change the interaction between serotonin 1A receptors and G(i)α(2). Two GSK3 inhibitors, N-(4-methoxybenzyl)-N'-(5-nitro-1,3-thiazol-2-yl)urea (AR-A014418) and 3-(5-bromo-1-methyl-1H-indol-3-yl)-4-(benzofuran-3-yl)pyrrole-2,5-dione (BIP-135), efficiently abolished the inhibitory effect of the 5-HT1BR agonist anpirtoline on serotonin release in mouse cerebral cortical slices. GSK3 inhibitors also facilitated the 5-HT1BR agonist anpirtoline-induced behavioral effect in the tail suspension test but spared anpirtoline-induced locomotor activity. These results suggest that GSK3β is a functional selective modulator of 5-HT1BR-regulated signaling, and GSK3 inhibitors fine-tune the physiological and behavioral actions of 5-HT1BR. Future studies may elucidate the significant roles of GSK3 in serotonin neurotransmission and implications of GSK3 inhibitors as functional selective modulators of 5-HT1BR.

Comparative proteomic analysis of follicular fluids from normal and cystic follicles in sows

Follicular fluid (FF) includes various biologically active proteins which can affect follicular growth and maturation. Certain proteins could reflect the physiological and pathological status of follicles. The aim of the present study was to explore the key proteins associated with pathogenesis of follicular cysts, some of which may be candidate biomarkers for the condition. We analysed the proteomes of FF from small, medium, large and cystic follicles by two-dimensional electrophoresis (2-DE) combined with mass spectrometry (MS). The protein components in FF were found to be significantly different among groups; about 300 proteins spots in each group were examined, and 32 differentially expressed proteins were identified from different groups. To further reveal the source of identified proteins, transcripts encoding two of these, transferrin and RBP-4, were detected in granulosa cells (GCs) by RT-PCR, as well as the proteins were detected in 24 h culture media of GCs by ELISA. High levels of RBP-4 were examined in FF of cystic follicles by 2-DE analysis, which were significantly different to those in large follicles (p < 0.05). In conclusion, the study enriches our understanding of the proteins of FF; RBP-4 and transferrin originate from passive transfer and follicular synthesized secretion, and RBP-4 might be a candidate biomarker for porcine follicular cysts. Combined with histological studies, these results further suggest that changes of the type and quantity of proteins in FF might be attributed to an abnormal metabolism of follicular cells and structure of follicular wall in cystic follicles. Our findings will contribute to further insight into the pathogenesis of follicular cysts.

Microcrystalline Silicon in a-SI:H Based Multljunction Solar Cells

Materials issues central to the application of microcrystalline silicon (μc-Si) doped layers in a-Si:H based solar cells are discussed, which include: (1) characterization of ultra-thin layers to be incorporated in the device, and (2) methods to promote nucleation of μc-Si on desired substrates within a thickness on the order of ∼100Å. Successful application of (μc-Si) in multijunction a-Si:H based solar cells are demonstrated.

Expression and prognostic role of pan-Ras, Raf-1, pMEK1 and pERK1/2 in patients with hepatocellular carcinoma

AIMS

Ras/Raf/mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK) signaling cascades play important roles in the transmission of signals involved in apoptosis. Importantly, components of these pathways are aberrantly expressed in human cancer. However, there is limited data linking clinical outcomes with the aberrant expression of this pathway. The present study analyzed the prognostic values of pan-Ras, Raf-1, phosphorylated MEK1 (pMEK1) and phosphorylated ERK1/2 (pERK1/2) in hepatocellular carcinoma (HCC).

METHODS

Expression of pan-Ras, Raf-1, pMEK1 and pERK1/2 in 81 HCC patients who underwent curative resection was examined by immunohistochemical staining. Long-term survival after resection of patients according to the expression of pan-Ras, Raf-1, pMEK1 and pERK1/2 was assessed using univariate analysis and multiple Cox proportional hazards model.

RESULTS

In univariate analysis, patients with Raf-1 or pMEK1 overexpression had shorter disease-free survival (DFS) (P<0.05) and poorer overall survival (OS) (P<0.05) than groups with weak-expression of Raf-1 or pMEK1, respectively. Patients with pan-Ras overexpression had poorer overall survival (OS) (P<0.05) than the group with weak-expression of pan-Ras. Importantly, Raf-1 overexpression was a promising prognostic marker for poor survival according to multivariate Cox regression analysis (DFS, Hazard Ratio 1.807, P = 0.035; OS, Hazard Ratio 1.959, P = 0.044).

CONCLUSIONS

Raf-1 overexpression could be considered as an independent prognostic biomarker in HCC and may predict early tumor recurrence and death for HCC patients. It can be used to stratify patients at higher risk for poor prognosis and help to select the appropriate therapeutic regime of HCC.

Local delivery of recombinant human bone morphogenetic protein-2 increases axonal regeneration and the expression of tau protein after facial nerve injury

This study explored the function and possible mechanism of bone morphogenetic protein-2 (BMP-2) in the healing of injured peripheral nerves in vivo. Rabbit facial nerves were injured by clamping and then treated with recombinant human BMP-2 (rhBMP-2) or phosphate-buffered saline (control) by injecting once during surgery and twice a day post-injury for 7 days. Facial nerve fragments within 5 mm of the clamping point were examined at different times post-surgery. Axon structures visualized by Bielschowsky staining were similar in experimental and control nerves 2 and 6 weeks post-injury. At 4 weeks post-injury, cross-section images of facial nerves showed that axons treated with rhBMP-2 were denser and thicker, and levels of tau protein were increased. It is concluded from these data that rhBMP-2 may affect injured facial nerve regeneration by inducing more neurons to return to embryonic patterns of tau gene expression.

Spectroscopic Characterization of Ion-Implanted GaN

We investigate implantation of high purity HVPE GaN with Mg, Be, C, Zn, Cd, Ca, N, O, P, As, Ne, and Ar. After annealing at 1300 °C, the material is characterized using low temperature photoluminescence (PL). The Mg acceptors exhibit much better optical activation than Be, C, Zn, Cd, or Ca acceptors implanted and annealed under the same conditions. Acceptor-bound exciton peaks and well-resolved donor-acceptor pair bands are observed for both Mg and Zn. A broad peak centered near 2.78 eV is obtained for Cd, confirming that it is deeper than Zn. Isoelectronic As or P exhibit sharp no-phonon bound exciton lines at 2.952 and 3.200 eV, respectively. Defect-related bands centered at 2.2 and 2.35 eV are studied. Both Be and C strongly enhance the yellow (2.2 eV) PL band, but no other impurities do so, including O.

Technological Development for Commercialization of Amorphous Silicon Based Multijunction Modules

Some of the significant steps in technological development for large-scale commercialization of amorphous silicon (a-Si:H) based multijunction photovoltaic modules are presented. These developments are establishing a high quality baseline process for manufacturing large-area ( ˜ 8 ft2) a-Si:H/a-SiGe:H tandem junction modules with improved stabilized conversion efficiency, throughput, yield, and reduced materials usage.

DMP1 processing is essential to dentin and jaw formation

Dentin matrix protein 1 (DMP1), an acidic protein that is essential to the mineralization of bone and dentin, exists as proteolytically processed fragments in the mineralized tissues. In this study, we characterized the tooth and jaw phenotypes in transgenic mice containing no wild-type DMP1, but expressing a mutant DMP1 in which Asp(213), a residue at one cleavage site, was replaced by Ala(213) (named "Dmp1-KO/D213A-Tg" mice). The teeth and mandible of Dmp1-KO/D213A-Tg mice were compared with those of wild-type, Dmp1-knockout (Dmp1-KO), and Dmp1-KO mice expressing the normal Dmp1 transgene. The results showed that D213A-DMP1 was not cleaved in dentin, and the expression of D213A-DMP1 failed to rescue the defects in the dentin, cementum, and alveolar bones in the Dmp1-KO mice. These findings indicate that the proteolytic processing of DMP1 is essential to the formation and mineralization of dentin, cementum, and jaw bones.

Effect of inhibition of heat-shock protein 90 on mutant c-Kit protein as modulated by mRNA expression and protein degradation through both proteasome and autophagy-mediated pathways

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Background: c-Kit is a known client protein of heat-shock protein 90 (Hsp90). Inhibition of Hsp90 can reduce the expression of c-Kit protein in human mastocytoma and gastrointestinal stromal tumor (GIST) cells, which is conceived through the proteasome degradation pathway.

Methods: COS-1 cells transfected with vectors containing CMV promoter-driven various c-Kit mutants (imatinib- sensitive or imatinib-resistant) and human GIST882 cells (with endogenous exon 13 mutant c-Kit) were used to investigate the efficacy NVP-AUY922, a new class of Hsp90 inhibitor, on suppressing the constitutive activation of mutated c-Kit. Detail mechanisms of protein regulation, as RNA transcription, RNA stability, and protein degradation were studied.

Results: NVP-AUY922 is more potent than 17-AAG to inhibit the proliferation of imatinib-sensitive GIST882 cells. Further study showed that NVP-AUY922 down-regulated both total and phosphorylated c-Kit proteins in dose- and time-dependent manners in both GIST882 cells and mutant c-Kit (including imatinib-resistant exon11/17 double mutants) expressed in COS-1 cells. Surprisingly, the NVP-AUY922-induced c-Kit degradation in both cell models could be reversed by proteasome-degradation inhibitor and autophagy inhibitor. The involvement of autophagy in NVP-AUY922-induced c-Kit protein degradation was further confirmed by co-localization of c-Kit and autophagosome by immuno-staining. In addition, NVP-AUY922 treatment resulted in a reduction of c-Kit mRNA level in GIST882 cells but not c-Kit expressing COS-1 cells, which could be explained by the use of CMV promoter in artificial COS-1 cell model.

Conclusions: Taken together, these findings provide the first evidence that down-regulation of mutant c-Kit protein by Hsp90 inhibitor involved both transcription and post-translation levels. Of the latter, autophagy- as well as proteasome-mediated degradation pathways were involved. These observations highlight the use of NVP-AUY922 either alone or in combination with autophagy modulators in imatinib-refractory, c-Kit-expressing GIST. Supported by 99D1-TC-CADOH03.

[Table: see text]