Breed-specific patterns of hepatic gluconeogenesis and glucocorticoid action in pigs

Abstract. In the present study, Erhualian and Pietrain pigs were employed to investigate the breed-specific patterns of hepatic gluconeogenesis by detecting the related enzyme mRNA expression, and to analyse the relationship with the hepatic glucocorticoid receptors and 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) expression. Furthermore, hepatic DNA methyltransferase 1 (DNMT1) expression was determined to detect DNA methyltransferase state difference between the two breeds. The results demonstrated that the Erhualian pigs exhibited significantly lower plasma lactate acid concentration, but higher liver lactate acid content than the Pietrain pigs. A significantly higher expression of pyruvate carboxylase (PC), fructose-1, 6-bisphosphatase (FBP) and the mitochondria phosphoenolpyruvate carboxykinase (PCK2) mRNA were observed in Erhualian pigs. The Erhualian pigs demonstrated a significantly higher expression of glucocorticoid receptor and 11β-HSD1 mRNA than the Pietrain pigs, though there was no difference in the hepatic cortisol content between the two breeds. The hepatic DNMT1 mRNA expression in the Erhualian pigs was significantly lower, and the DNMT1 protein content in Erhualian pigs tended to be decreased compared with Pietrain pigs (P=0.066). The results suggest that the Erhualian pigs demonstrated higher hepatic gluconeogenesis capacity in comparison to the Pietrain pigs. The up-regulation of hepatic glucocorticoid receptor and 11β-HSD1 expression may be involved in the enhanced hepatic gluconeogenesis in Erhualian pigs. Moreover, the down-regulation of DNMT1 in Erhualian pigs implies possible involvement of DNA methylation in a breed-specific pattern of hepatic gluconeogenesis.

In ovo leptin administration accelerates post-hatch muscle growth and changes myofibre characteristics, gene expression and enzymes activity in broiler chickens

To evaluate the effect of maternal leptin on muscle growth, we injected 0 μg (control, CON), 0.5 μg (low leptin dose, LL) or 5.0 μg (high leptin dose, HL) of recombinant murine leptin dissolved in 100 μl of PBS into the albumen of broiler eggs prior to incubation. The newly hatched chicks were all raised under the same conditions until 21 days of age (D21), when body weight was measured and samples of gastrocnemius muscle were collected and weighed. Myosin ATPase staining was applied to identify myofibre types and measure the cross-sectional area (CSA) of myofibres. Real-time PCR was performed to quantify leptin receptor (LEPR), insulin-like growth factor 1 (IGF-1), IGF-1 receptor (IGF-1R), growth hormone receptor (GHR) and myostatin (MSTN) mRNA expression in the gastrocnemius muscle. The activity of calpains (CAPNs) in the gastrocnemius muscle was measured using a quantitative fluorescence detection kit. Male chickens treated with both high and low doses of leptin had significantly higher (p < 0.05) body weight on D21. The high leptin significantly increased the CSA (p < 0.05) of gastrocnemius muscle in male chickens, which coincided with a 93% increase (p < 0.05) in IGF-1 mRNA expression. Likewise, the LL dose increased the weight of gastrocnemius muscle in male chickens (p < 0.05), which was accompanied by a 41% down-regulation (p < 0.05) of MSTN mRNA expression and a decreased activity of CAPNs. However, all these changes were not observed in female chickens. The proportion of myofibre types did not altered. No significant change was detected for LEPR and GHR mRNA expression. These results indicate that in ovo leptin treatment affects skeletal muscle growth in chickens in a dose-dependent and sex-specific manner. The altered expression of IGF-1, MSTN mRNA and activity of CAPNs in skeletal muscle may be responsible for such effects.

Breaking the speed limits of phase-change memory

Phase-change random-access memory (PCRAM) is one of the leading candidates for next-generation data-storage devices, but the trade-off between crystallization (writing) speed and amorphous-phase stability (data retention) presents a key challenge. We control the crystallization kinetics of a phase-change material by applying a constant low voltage via prestructural ordering (incubation) effects. A crystallization speed of 500 picoseconds was achieved, as well as high-speed reversible switching using 500-picosecond pulses. Ab initio molecular dynamics simulations reveal the phase-change kinetics in PCRAM devices and the structural origin of the incubation-assisted increase in crystallization speed. This paves the way for achieving a broadly applicable memory device, capable of nonvolatile operations beyond gigahertz data-transfer rates.

In ovo leptin administration inhibits chorioallantoic membrane angiogenesis in female chicken embryos through the STAT3-mediated vascular endothelial growth factor (VEGF) pathway

Previous studies indicate that leptin regulates placental angiogenesis and fetal growth in mammals and that in ovo leptin administration affects embryonic development and hatch weight in the chicken. To test the hypothesis that leptin affects embryonic growth through modifying chorioallantoic membrane (CAM) angiogenesis, we injected 0.5 μg of recombinant murine leptin into the albumen of fertilized eggs before incubation. On embryonic day 12 (E12), the number and the total area of blood vessels on CAM were measured, and expression of genes involved in angiogenesis was quantitated to show the possible mechanisms. Leptin in ovo administration decreased (P < 0.05) both the total area of blood vessels and the number of small-sized capillaries on CAM of E12 female chicken embryos, which coincided with significantly decreased (P < 0.05) embryo weight on E12 and BW at hatching. Vascular endothelial growth factor (VEGF) and inducible and endothelial nitric oxide synthases (iNOS and eNOS) were all downregulated (P < 0.05) in CAM both at the mRNA and protein/activity levels with reduced (P < 0.05) nitric oxide (NO) concentration in chorioallantoic fluid of female embryos. Furthermore, signal transducer and activator of transcription-3 (STAT3) was found to be diminished (P < 0.05) both at the mRNA and protein levels and associated with decreased (P < 0.05) binding of STAT3 to VEGF promotor in the CAM of leptin-treated E12 female embryos. These data suggest that in ovo leptin administration affects CAM angiogenesis and embryo growth in female chicken embryos, probably through STAT3-mediated VEGF/NO pathways.

Cysteamine improves growth performance and gastric ghrelin expression in preweaning piglets

The aim of the present study was to investigate the effect of cysteamine on growth performance of preweaning piglets and gastric expression of ghrelin mRNA in vivo and in vitro. Twelve litters of newborn piglets were allocated randomly to control and treatment groups. From 15 d of age, piglets in the control group were fed basal creep diet, whereas the treatment group received basal diet supplemented with 120 mg cysteamine per kg of diet until weaning on 35 d of age. Body weight gain, creep feed consumption, and diarrhea rates were recorded, and gastric mucosal tissues were collected for quantifying mRNA expression. To evaluate the direct effect of cysteamine on gastric ghrelin expression, primary cultures of gastric mucosal cells isolated from 35-d-old piglets were exposed to cysteamine for 20 h at 0, 1, 10, and 100 μg/mL, respectively. Dietary cysteamine increased (P < 0.05) average daily creep feed consumption and BW gain in preweaning pigs, which was accompanied by reduction in diarrhea rates. At 35 d of age, piglets treated with cysteamine showed increased (P < 0.05) ghrelin and gastrin and decreased (P < 0.05) somatostatin mRNA expression in gastric mucosa. Moreover, dietary cysteamine treatment increased serum concentration of gastrin (P < 0.05). In vitro, cysteamine significantly increased ghrelin mRNA expression in gastric mucosal cells at the concentration of 10 μg/mL. In conclusion, dietary cysteamine is effective in improving the growth performance and health condition of preweaning piglets, which is associated with its stimulatory effects on gastric ghrelin mRNA expression both in vivo and in vitro.

Coenzyme Q(10) enhances dermal elastin expression, inhibits IL-1α production and melanin synthesis in vitro

Coenzyme Q(10) (CoQ(10) ) is a well-known antioxidant and has been used in many skincare products for anti-ageing purpose. However, the molecular mechanisms of CoQ(10) function in skin cells are not fully understood. In this paper, we compared the effects of CoQ(10) on primary human dermal fibroblasts from three individuals, including adult. We demonstrated that CoQ(10) treatment promoted proliferation of fibroblasts, increased type IV collagen expression and reduced UVR-induced matrix metalloproteinases-1 (MMP-1) level in embryonic and adult cells. In addition, CoQ(10) treatment increased elastin gene expression in cultured fibroblasts and significantly decreased UVR-induced IL-1α production in HaCat cells. Taken together, CoQ(10) presented anti-ageing benefits against intrinsic ageing as well as photo damage. Interestingly, CoQ(10) was able to inhibit tyrosinase activity, resulting in reduced melanin content in B16 cells. Thus, CoQ(10) may have potential depigmentation effects for skincare.

Investigation of aqueous-phase photooxidation of glyoxal and methylglyoxal by aerosol chemical ionization mass spectrometry: observation of hydroxyhydroperoxide formation

Aqueous-phase processing of glyoxal (GLY) and methylglyoxal (MG) produces highly oxygenated, less volatile organic acids that can contribute to SOA formation and aging. In this study, aerosol chemical ionization mass spectrometry (aerosol CIMS) is employed to monitor aqueous-phase photooxidation of GLY and MG. Using iodide (I(-)) as the reagent ion, aerosol CIMS can simultaneously detect important species involved in the reactions: organic acids, peroxides, and aldehydes, so that the reconstructed total organic carbon (TOC) concentrations from aerosol CIMS data agree well with offline TOC analysis. This study also reports the first direct detection of hydroxyhydroperoxide (HHP) formation from the reaction of H(2)O(2) with GLY or MG. The formation of HHPs is observed to be reversible and an estimate of their equilibrium constants is made to be between 40 and 200 M(-1). Results of this study suggest that HHPs can form additional formic acid and acetic acid via photooxidation and regenerate GLY or MG during photooxidation, compensating their loss. HHP formation needs to be further studied for inclusion in aqueous-phase chemical models given that it may affect the aqueous partitioning of carbonyls in the atmosphere.

Sulphoraphane inhibited the expressions of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 through MyD88-dependent toll-like receptor-4 pathway in cultured endothelial cells

BACKGROUND AND AIMS

Chronic inflammation plays pivotal roles in both cancer and cardiovascular diseases. A large body of evidence suggests that high intake of cruciferous vegetables is closely related with low risk of these disorders. However, the underlying mechanisms of protection are not fully understood. The aim of this study is to test the protective effects of an isothiocyanate sulphoraphane on inflammatory injury and related regulation pathways in cultured endothelial cells.

METHODS AND RESULTS

The expressions of adhesion molecules were determined by TaqMan real-time polymerase chain reaction (PCR) and Western blot analysis. Nuclear factor-kappa B (NF-кB) translocation was detected by immunofluorescent hybridisation. Other proteins were measured by Western blot analysis. The results demonstrated that sulphoraphane significantly suppresses the expression of intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 stimulated by lipopolysaccharide (LPS) both at the transcriptional and translational levels. In addition, sulphoraphane inhibited the translocation of NF-кB into the nucleus. Sulphoraphane decreased the phosphorylation of extra-cellular signal-regulated kinase (ERK), Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK), while further blockade and activation using individually specific agents confirm that p38 MAPK and JNK are mainly involved. Interestingly, sulphoraphane down-regulated Toll-like receptor (TLR)-4, a receptor of LPS located on the membrane. In addition, MyD88, an effector downstream TLR-4 signal pathway was subsequently attenuated.

CONCLUSION

Taken all together, adhesion molecules are confirmed to be the novel targets of sulphoraphane in preventing inflammatory insult to endothelial cells. Sulphoraphane suppressed TLR-4 followed by MyD88 and downstream factors such as p38 MAPK and JNK, ultimately blocking NF-кB translocation and the subsequent expression of adhesion molecules. These data suggested a novel inflammatory pathway mediated by sulphoraphane.

Colocalization of myostatin and decorin in bovine skeletal muscle

Abstract. The objectives of this study were to investigate the expression and localization of myostatin (MSTN) and decorin (DCN) in bovine skeletal muscle and to find associations with muscle fibre and adipocyte development. Samples of two muscles, known for differences in meat quality and fibre composition, namely longissimus muscle (LD) and semitendinosus muscle (ST), were obtained from 18 months old bulls of the F2 generation of a Charolais×Holstein cross. Individual muscle sections were stained for determination of size and type of muscle fibres and immunohistochemical detection of the proteins. The mRNA abundance and protein expression of MSTN and DCN were quantified by real-time PCR and Western blot, respectively. As expected, the ST had more fast fibres, less fibres of the intermediate and the slow type, and less intramuscular fat than the LD. Despite these differences, the mRNA and protein abundance of MSTN was comparable in both muscles. The protein abundance of MSTN inhibitors, namely MSTN propeptide and DCN, was greater in LD, which may have affected the biological activity of mature MSTN. Myostatin propeptide was detected in all muscle fibres; however the mature MSTN was detected to a much lower extent and mainly in slow fibres. Furthermore, MSTN was localized in close proximity to DCN in intermyocellular space, suggesting possible interactions between both proteins and effects on muscle structure and meat quality. The role of MSTN and DCN as well as their interactions in the determination of muscle composition needs to be further elucidated.

Eya2 is required to mediate the pro-metastatic functions of Six1 via the induction of TGF-β signaling, epithelial-mesenchymal transition, and cancer stem cell properties

Six1 is a critical regulator of embryonic development that requires interaction with the Eya family of proteins (Eya1-4) to activate the transcription of genes involved in neurogenesis, myogenesis, and nephrogenesis. While expression of Six1 and Eya family members is predominantly observed in development, their overexpression is observed in numerous cancers. Importantly, both Six1 and Eya have independently been shown to mediate breast cancer metastasis, but whether they functionally interact during tumor progression has not been explored. Herein we demonstrate that knockdown of Eya2 in MCF7 mammary carcinoma cells reverses the ability of Six1 to induce TGF-β signaling, as well as to induce characteristics associated with epithelial-mesenchymal transition (EMT) and cancer stem cells (CSCs), suggesting that Six1 is dependent on Eya2 to mediate numerous pro-metastatic characteristics. The importance of the Six1/Eya interaction in human breast cancer is underscored by the finding that high levels of Six1 correlate with shortened time to relapse and metastasis as well as decreased survival only when co-expressed with high levels of Eya2. Overall, these data implicate Eya2 as a necessary cofactor for many of the metastasis promoting functions of Six1, suggesting that targeting the Six1/Eya interaction may inhibit breast cancer progression. Since Six1 and Eya2 are not highly expressed in most adult tissues, the Six1-Eya interaction may be a valuable future therapeutic target whose inhibition would be expected to impair breast cancer progression while conferring limited side effects.

Drag-reducing polymers diminish near-wall concentration of platelets in microchannel blood flow

The accumulation of platelets near the blood vessel wall or artificial surface is an important factor in the cascade of events responsible for coagulation and/or thrombosis. In small blood vessels and flow channels this phenomenon has been attributed to the blood phase separation that creates a red blood cell (RBC)-poor layer near the wall. We hypothesized that blood soluble drag-reducing polymers (DRP), which were previously shown to lessen the near-wall RBC depletion layer in small channels, may consequently reduce the near-wall platelet excess. This study investigated the effects of DRP on the lateral distribution of platelet-sized fluorescent particles (diam. = 2 μm, 2.5 × 10⁸/ml) in a glass square microchannel (width and depth = 100 μm). RBC suspensions in PBS were mixed with particles and driven through the microchannel at flow rates of 6-18 ml/h with and without added DRP (10 ppm of PEO, MW = 4500 kDa). Microscopic flow visualization revealed an elevated concentration of particles in the near-wall region for the control samples at all tested flow rates (between 2.4 ± 0.8 times at 6 ml/h and 3.3 ± 0.3 times at 18 ml/h). The addition of a minute concentration of DRP virtually eliminated the near-wall particle excess, effectively resulting in their even distribution across the channel, suggesting a potentially significant role of DRP in managing and mitigating thrombosis.

Entanglement of light-shift compensated atomic spin waves with telecom light

Entanglement of a 795 nm light polarization qubit and an atomic Rb spin-wave qubit for a storage time of 0.1 s is observed by measuring the violation of Bell's inequality (S=2.65±0.12). Long qubit storage times are achieved by pinning the spin wave in a 1064 nm wavelength optical lattice, with a magic-valued magnetic field superposed to eliminate lattice-induced dephasing. Four-wave mixing in a cold Rb gas is employed to perform light qubit conversion between near infrared (795 nm) and telecom (1367 nm) wavelengths, and after propagation in a telecom fiber, to invert the conversion process. Observed Bell inequality violation (S=2.66±0.09), at 10 ms storage, confirms preservation of memory-light entanglement through the two stages of light qubit frequency conversion.

Curcumin attenuates the effects of transport stress on serum cortisol concentration, hippocampal NO production, and BDNF expression in the pig

Curcumin, the active component of curcuma longa, has been reported to be effective in alleviating chronic stress-induced disorders in rodents by modulating neuroprotection and neuroendocrine functions of the central nervous system, especially hippocampus. However, it is unclear whether curcumin can attenuate the subacute stress response induced by 2 h of road transport in the pig. Therefore, the present study was designed to identify the changes of serum cortisol concentration, hippocampal nitric oxide (NO) production, and related gene expression in response to 2 h of transport and to explore whether curcumin treatment (8 mg/kg, p.o.) for 21 d before transport may alleviate the stress-induced responses in the hippocampus of pigs. We found that 2 h of transport elevated serum cortisol concentration (P < 0.01), increased hippocampal NO content, and reduced brain-derived neurotrophic factor (BDNF) mRNA expression in pigs not treated with curcumin, whereas these stress responses were all reversed or attenuated in curcumin-treated pigs. In addition, the stress-induced increase in the expression of constitutive nitric oxide synthase (cNOS) and enzyme activities of total NOS, cNOS, and inducible NOS (iNOS) was also reversed or attenuated in curcumin-treated pigs. However, neither transport nor curcumin caused significant alterations in hippocampal expression of 11β-hydroxysteroid dehydrogenase type 1 and type 2 (11β-HSD1 and 2), glucocorticoid and mineralocorticoid receptors (GR and MR), or pro-/anti-apoptotic molecules (Bax-α and Bcl-xL). These results suggest that curcumin can alleviate subacute stress response in pigs through its neuroprotective effects on modulating hippocampal NO production and BDNF expression.

Epigenetic memory in induced pluripotent stem cells

Somatic cell nuclear transfer and transcription-factor-based reprogramming revert adult cells to an embryonic state, and yield pluripotent stem cells that can generate all tissues. Through different mechanisms and kinetics, these two reprogramming methods reset genomic methylation, an epigenetic modification of DNA that influences gene expression, leading us to hypothesize that the resulting pluripotent stem cells might have different properties. Here we observe that low-passage induced pluripotent stem cells (iPSCs) derived by factor-based reprogramming of adult murine tissues harbour residual DNA methylation signatures characteristic of their somatic tissue of origin, which favours their differentiation along lineages related to the donor cell, while restricting alternative cell fates. Such an 'epigenetic memory' of the donor tissue could be reset by differentiation and serial reprogramming, or by treatment of iPSCs with chromatin-modifying drugs. In contrast, the differentiation and methylation of nuclear-transfer-derived pluripotent stem cells were more similar to classical embryonic stem cells than were iPSCs. Our data indicate that nuclear transfer is more effective at establishing the ground state of pluripotency than factor-based reprogramming, which can leave an epigenetic memory of the tissue of origin that may influence efforts at directed differentiation for applications in disease modelling or treatment.

Twisted split-ring-resonator photonic metamaterial with huge optical activity

Coupled split-ring-resonator metamaterials have previously been shown to exhibit large coupling effects, which are a prerequisite for obtaining large effective optical activity. By a suitable lateral arrangement of these building blocks, we completely eliminate linear birefringence and obtain pure optical activity and connected circular optical dichroism. Experiments around a 100 THz frequency and corresponding modeling are in good agreement. Rotation angles of about 30 degrees for 205 nm sample thickness are derived.