Effect of Insulin on the Differential Expression of VLDL Receptor Isoforms of SGC7901 Cell and Its Biological Implication

This study examined the effect of insulin on the expression of very low density lipoprotein receptor (VLDLR) subtypes of SGC7901 cells and discussed its biological implication.In vitro, moderately or poorly-differentiated human gastric adenocarcinoma cell line SGC7901 was incubated with insulin for different lengths of time, and then the expression of protein and RNA level in VLDLR subtypes were detected by Western blotting and real-time PCR, respectively.The results showed that, at certain time interval, insulin could down-regulate expression of type Ⅰ VLDLR and up-regulate the expression of type Ⅱ VLDLR in SGC7901 cells, at both protein and RNA level.We are led to conclude that insulin serves as a regulator in maintaining the balance between glucose and lipid metabolism in vivo, possibly through its effect on the differential expression of VLDLR subtypes.

Effect of Several Common Processing Methods on Content Changes of Resistant Starch and Main Nutrients in ‘Luotian Chestnut’

Using ＇Luotian chestnut＇ as the raw material, the content changes of resistant starch and main nutrients in the processed fruit were studied after taken common processing of high-temperature steaming of canned food, sand-mixed frying and cooking without shells, with the aim to find out the effects of different processing methods on the content changes of nutrients in chestnuts. The result showed that there were significant differences in the resistant starch contents by different processing methods. After processing, the retention degree of resistant starch was the lowest using the methods of sand-mixed frying, of 42.42%, while the highest was found in canned chestnut products, of 93.16%. Among the main nutrients, adding water and sugar would reduce content of resistant starch, while increasing the protein content would promote the retention of resistant starch retention. The changes in lipid content had no effect or not a single promoting or weakening effects on the content of resistant starch.

Per1/Per2 double knockout transcriptome analysis reveals circadian regulation of hepatic lipid metabolism

Scope: Circadian disorder and high-fat diet(HFD)can disturb lipid metabolism homeostasis and may promote the development of various metabolic diseases. The relationship between them is of great concern. This study aimed to explore the effects of Per1/Per2 double knockout(DKO)on hepatic lipid metabolism in mice under HFD and HFD with docosahexaenoic acid(DHA)substitution. Methods and results: Both wild type(WT)and DKO male C57BL/6 mice were fed with normal chow diet(CON), HFD, or HFD with DHA substitution(AO)for 15 weeks. At the end of the experiment, mice were sacrificed at zeitgeber time(ZT)0(7:00 am)or ZT12(7:00 pm). Pathological indicators were determined using histological and biochemical methods. Hepatic transcriptome sequencing analysis showed that DKO mice exhibited multiple dysfunctions in diurnal rhythm, drug metabolism, cell cycle, cancer pathways, and lipid metabolism. HFD had greater effects on fatty acid oxidation and cholesterol synthesis and metabolism in Per1-/-Per2-/-mice, which was improved by DHA substitution. Conclusions: Per1/Per2 played an important role in the circadian regulation of hepatic lipid metabolism, and DKO mice were more sensitive to HFD. DHA can improve circadian-related lipid metabolism disruption induced by HFD in mice.

Chronic consumption of thermally processed palm oil or canola oil modified gut microflora of rats

Dietary oils have critical influences on human health,and thermally cooking or frying modify the components and nutritional functions of oils.Palm oil was the most widely used oil in food processing industry,but its health effects remain debatable.In the current study,we aimed to compare the effects of thermally oxidized palm oil and canola oil on gut microbiota.Palm oil or canola oil were heated at 180°C for 10 h to prepare high-fat diets.Rats were fed high-fat diets for 3 months,and hematological properties,gut microflora composition and intestinal gene expression were examined.The results indicated that heated canola oil consumption elevated plasma total cholesterol and LDL-c levels compared with unheated canola oil,but heated palm oil do not had these effects;and consumption of heated palm oil significantly elevated the relative abundance of Lactobacillucs and Roseburia in gut,compared with non-heated palm oil or two canola oil groups.Moreover,intestinal expression of IL-22 was increased in heated palm oil fed animal,though ZO-1 and GPR41 were reduced.In conclusion,heating process may enhance the effects of palm oil on proliferation of probiotics Lactobacillucs,and weaken the effects of canola oil on cholesterol transport and metabolism.

Alpinia officinarum Hance extract alleviates particulate matter-induced lung injury in mice

Objective: To evaluate the effect of Alpinia officinarum Hance(A. officinarum) extract on lung injury caused by particulate matter(PM). Methods: The Kunming mice were intranasally instilled with PM and treated with A. officinarum extract for 3 weeks. Bronchoalveolar lavage fluid, blood and lung samples were collected for biochemical, serological and histopathological studies. Results: Serological analysis showed that albumin levels, lactate dehydrogenase and alkaline phosphatase activities in bronchoalveolar lavage fluid were significantly reduced after administrations of 50, 100 and 200 mg/kg of A. officinarum extracts to the PM injured mice. Markers of oxidative stress, nitric oxide, malondialdehyde levels and nitric oxide synthase activities, were significantly decreased. Correspondingly, total superoxide dismutase activity was improved dramatically. The expressions of interleukin-6 and tumor necrosis factor alpha were also down-regulated obviously. In addition, pathological sections of lung tissue showed that A. officinarum could reduce the infiltration of inflammatory cells, pulmonary edema and pulmonary fibrosis. These results showed that A. officinarum extract could alleviate PMinduced lung injury via reducing the permeability of cell membranes in lung tissue, eliminating oxidative stress and relieving inflammatory response.Conclusions: A. officinarum extract was an efficient treatment for PM-induced lung injury in mice, and it may be a promising therapeutic agent in future.

ER Stress-Mediated Cell Damage Contributes to the Release of EDA~＋ Fibronectin from Hepatocytes in Nonalcoholic Fatty Liver Disease

Fibronectin containing extra domain A（EDA~＋ FN）,a functional glycoprotein participating in several cellular processes,correlates with chronic liver disease.Herein,we aim to investigate the expression and secretion of EDA~＋ FN from hepatocytes in nonalcoholic fatty liver disease（NAFLD） and the underlying mechanisms.Circulating levels of EDA~＋ FN were determined by ELISA in clinical samples.Western blotting and flow cytometry were performed on L02 and Hep G2 cell lines to analyze whether the levels of EDA~＋ FN were associated with endoplasmic reticulum（ER） stress-related cell death.Circulating levels of EDA~＋ FN in NAFLD patients were significantly higher than those in control subjects,and positively related with severity of ultrasonographic steatosis score.In cultured hepatocytes,palmitate up-regulated the expression of EDA~＋ FN in a dose-dependent manner.Conversely,when the cells were pretreated with 4-phenylbutyrate,a specific inhibitor of ER stress,up-regulation of EDA~＋ FN could be abrogated.Moreover,silencing CHOP by sh RNA enhanced the release of EDA~＋ FN from hepatocytes following palmitate treatment,which was involved in ER stress-related cell damage.These findings suggest that the up-regulated level of EDA~＋ FN is associated with liver damage in NAFLD,and ER stress-mediated cell damage contributes to the release of EDA~＋ FN from hepatocytes.

Acidic rearrangement of benzyl group in flavone benzyl ethers and its regioselectivity

The benzyl-substituted flavone compounds are rare in nature, while some of which have interesting biological activities. The total synthesis of benzyl-substituted flavone derivatives via the acidic rearrangement of benzyl groups in flavone benzyl ethers, and the complicated regioselectivity of the rearrangement were reported. The regioselectivity was proposed to be determined by the steric hindrance as well as the ease of electrophilic substitution reaction for benzyl cations at different positions of corresponding debenzylated fiavone compounds.

Evidence from ^(18)O feeding studies for hydroxyl group donor in the reaction catalyzed by cytidylate hydroxymethylase MilA

5-Hydroxymethylcytosine (5hmC) was present in T-even phage and mammalian DNA. 5hmC in phage is formed by hydroxymethylation of the cytosine base in deoxycytidylate (dCMP) by deoxycytidylate hydroxymethylase (CH), which uses the solvent water as the hydroxyl group donor. By contrast, 5hmC is formed in mammal zygotes by the oxidation of 5-methylcytosine (5mC). 5hmC was also present in a nucleoside antibiotic mildiomycin and its formation is governed by a cytidylate hydroxymethylase MilA. However, the catalytic mechanism remains unknown. In the present study, we purified His-tagged MilA and fed its in vitro reaction with H218O. The LC-MS analysis of the product revealed that 18O was incorporated into the hydroxymethylated CMP (HmCMP), and the secondary MS result of 18O-labeled HmCMP indicated that 18O was incorporated into the cytosine of HmCMP. The results demonstrate that MilA uses solvent water as the hydroxyl group donor like CH. Moreover, Thr102 of MilA was predicted as potential critical amino acid anchoring one molecule of water for hydroxylation. Finally, organizational context comparison in microbial genomes reveals that six homologous ORFs originally annotated as putative thymidylate synthase (TS) are more likely to be CMP hydroxymethylase.