Proteomic study of hypothalamus in pigs exposed to heat stress.

BACKGROUND: With evidence of warming climates, it is important to understand the effects of heat stress in farm animals in order to minimize production losses. Studying the changes in the brain proteome induced by heat stress may aid in understanding how heat stress affects brain function. The hypothalamus is a critical region in the brain that controls the pituitary gland, which is responsible for the secretion of several important hormones. In this study, we examined the hypothalamic protein profile of 10 pigs (15 ± 1 kg body weight), with five subjected to heat stress (35 ± 1 °C; relative humidity = 90%) and five acting as controls (28 ± 3 °C; RH = 90%). RESULT: The isobaric tags for relative and absolute quantification (iTRAQ) analysis of the hypothalamus identified 1710 peptides corresponding to 360 proteins, including 295 differentially expressed proteins (DEPs), 148 of which were up-regulated and 147 down-regulated, in heat-stressed animals. The Ingenuity Pathway Analysis (IPA) software predicted 30 canonical pathways, four functional groups, and four regulatory networks of interest. The DEPs were mainly concentrated in the cytoskeleton of the pig hypothalamus during heat stress. CONCLUSIONS: In this study, heat stress significantly increased the body temperature and reduced daily gain of body weight in pigs. Furthermore, we identified 295 differentially expressed proteins, 147 of which were down-regulated and 148 up-regulated in hypothalamus of heat stressed pigs. The IPA showed that the DEPs identified in the study are involved in cell death and survival, cellular assembly and organization, and cellular function and maintenance, in relation to neurological disease, metabolic disease, immunological disease, inflammatory disease, and inflammatory response. We hypothesize that a malfunction of the hypothalamus may destroy the host physical and immune function, resulting in decreased growth performance and immunosuppression in heat stressed pigs.

Magnetic molecularly imprinted specific solid-phase extraction for determination of dihydroquercetin from Larix griffithiana using HPLC.

The naturally occurring quercetin flavonoid, dihydroquercetin, is widely distributed in plant tissues and has a variety of biological activities. Herein, a magnetic molecularly imprinted solid-phase extraction was tailor made for selective determination of dihydroquercetin in Larix griffithiana using high-performance liquid chromatography. Amino-functionalized core-shell magnetic nanoparticles were prepared and characterized using scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry, and infrared spectroscopy. The polymer had an average diameter of 250 ± 2.56 nm and exhibited good stability and adsorption for template molecule, which is enriched by hydrogen bonding interaction. Multiple factors for extraction, including loading, washing, elution solvents, and extraction time, were optimized. The limit of detection was 1.23 µg/g. The precision determined at various concentration of dihydroquercetin was less than 4% and the mean recovery was between 74.64 and 101.80%. It has therefore been shown that this protocol can be used as an alternative extraction to quantify dihydroquercetin in L. griffithiana and purify quercetin flavonoid from other complex matrices.

Magnetic molecularly imprinted polymers doped with graphene oxide for the selective recognition and extraction of four flavonoids from Rhododendron species.

Herein, a novel magnetic molecularly imprinted polymer doped with reticular graphene oxide (Fe3O4@SiO2-GO@MIPs) was synthesized for the selective recognition and extraction of 4 flavonoids (farrerol, taxifolin, kaempferol, and hyperin) from Rhododendrons species. The Fe3O4@SiO2-GO@MIPs with lamellar membranes showed outstanding adsorption capacity. The 3D cavities complementary to the "shape" of farrerol were "imprinted" on the polymer framework after removal of farrerol template. Competitive binding assays showed that the polymer has a higher selectivity for farrerol compared with other analogues and references. The Fe3O4@SiO2-GO@MIPs as solid-phase extraction adsorbents combined with liquid chromatography-tandem quadrupole mass spectrometry (LC-MS/MS) was used for selective determination of four flavonoids from Rhododendrons samples. The limits of detection (LOD) were 0.07, 0.08, 0.06, and 0.08 µg L-1 for farrerol, taxifolin, kaempferol, and hyperin, respectively. These results suggest that the prepared Fe3O4@SiO2-GO@MIPs have the potential applicability to extract, purify, and enrich flavonoids from herbs, supplements, and other natural products.

[Effect of Fuzhenghuayu compound on hepatocyte expression of Nrf2 in a mouse model of hepatic fibrosis].

OBJECTIVE: To investigate the effect of Fuzhenghuayu compound (FZHc) on expression of nuclear factor E2-related factor 2 (Nrf2) in hepatocytes under conditions of hepatic fibrosis using a mouse model. METHODS: Mice were randomly assigned to a control group and a hepatic fibrosis model group. The control group was further divided into three subgroups for use as normal controls (A1), mineral oil-treated controls (A2), and FZHc-treated controls (A3); the hepatic fibrosis model group was administered carbon tetrachloride (CC14 dissolved in mineral oil and injected intraperitoneally) and further divided into four subgroups for use as 6-weeks models (B1), 10-weeks models (B2), low-dose (L)-FZHc models (C1), and high-dose (H)-FZHc models (C2). The FZHc (capsule powder diluted with double-distilled water to 0.1 g/mL) was administered via gastric perfusion to groups A3, C1, and C2 starting at week 7 of the experiment. At the end of week 6 and 10, hepatic specimens were collected and evaluated for degree of hepatic fibrosis and inflammation using routine haematoxylin-eosin staining and Masson staining. Immunohistochemical analysis was performed to measure the hepatocyte expression of Nrf2, NAD(P)H quinine oxidoreductase 1 (Nqol), a-smooth muscle actin (a-SMA) and fibronectin (FN). Real-time fluorescence quantitative PCR was used to measure Nrf2 mRNA expression. Western blotting was used to detect Nrf2 and Nqol total protein expression and Nrf2 nuclear translocation. F test, LSD test and ridit test were used for statistical analyses. RESULTS: Compared with the B2 group (ridit value: 0.09), the model groups treated with FZHc showed significantly lower degrees of hepatic inflammation and fibrosis for both the low (C1 group, ridit value: 0.32) and high doses (C2 group, ridit value: 0.40) (F =82.927, P less than 0.05). In addition, compared with the B2 group, the model groups treated with FZHc showed significantly decreased expression of a-SMA and FN proteins, with a dose-dependent trend (by immunohistochemistry: C 1 group at the end of 10 weeks, F =77.421, 118.262, P less than 0.05; C2 group, P =0.002, 0.013) and significantly increased expression of Nrf2 and Nqol proteins (by immunohistochemistry:C1 and C2 groups at the end of 10 weeks, F =182.537, 75.615, P less than 0.05 and by westen blotting: F =45.664, 127.673, P less than 0.05), which also showed a dose-dependent trend (C2 group, P =0.000, 0.014; 0.005, 0.014). Western blotting also indicated that the amount of nuclear transported Nrf2 was higher in the C1 and C2 groups at the end of 10 weeks (vs. B2 group, F =94.787, P less than 0.05), and the amount of nuclear transported Nrf2 was significantly higher in the C2 group (vs. C1 group, P =0.044). Nrf2 mRNA expression was significantly higher in the C1 group than in the B2 group (F =3230.105, P less than 0.05), and the C2 group had more substantially increased expression (P =0.001); there was no statistical difference found between groups B1 and B2 (P =0.094). CONCLUSION: Fuzhenghuayu compound increased the expression of Nrf2 mRNA and protein under conditions of hepatic fibrosis in mice and stimulated Nrf2 nuclear transport, as well as increased expression of the Nrf2 target gene Nqol that is known to suppress activation of hepatic stellate cells and decrease the deposition of FN. Therefore, Fuzhenghuayu compound may ameliorate hepatocyte injury in hepatic fibrosis in mice by exerting an antihepatic fibrosis effect.