Changes in the composition of the extracellular matrix accumulated by mesenchymal stem cells during in vitro expansion

One of the approaches to preserve the properties of mesenchymal stem cells (MSCs) during in vitro expansion is to use cell culture substrates. MSCs are known to generate the extracellular matrix (ECM) proper to preserve their proliferative capacity in vitro, but extensive expansion is considered to deprive MSCs of the capacity to prepare such ECM. In order to examine the features of ECM proper that is required to preserve the proliferative capacity of MSCs, we analyzed the changes in the composition of ECM accumulated by MSCs during in vitro expansion. Biochemical and immunological analysis showed that collagen and laminin content decreased during expansion. Immunofluorescence and ultrastructural analyses showed that the ECM structure changed from a dynamic fibrous, porous and steric structure to a static, crammed, and planar one. The results of Western blotting analysis suggested loose intermolecular association in ECM molecules accumulated by extensively proliferated MSCs. The ECM prepared by extensively proliferated MSCs was less effective to recover their proliferative capacity than that prepared by less proliferated cells. Our results suggest that a cell culture substrate to expand MSCs requires abundance in collagen and basement membrane components, and steric, porous and fibrous structure in which ECM molecules are tightly associated.     

Characteristics of various fibrolytic isozyme activities in the rumen microbial communities of Japanese Black and Holstein Friesian cattle under different conditions

Rumen microorganisms produce various fibrolytic enzymes and degrade lignocellulosic materials into nutrient sources for ruminants; therefore, the characterization of fibrolytic enzymes contributing to the polysaccharide degradation in the rumen microbiota is important for efficient animal production. This study characterized the fibrolytic isozyme activities of a rumen microbiota from four groups of housed cattle (1, breeding Japanese Black; 2, feedlot Japanese Black; 3, lactating Holstein Friesian; 4, dry Holstein Friesian). Rumen fluids in all cattle groups showed similar concentrations of total volatile fatty acids and reducing sugars, whereas acetic acid contents and pH were different among them. Predominant genera were commonly detected in all cattle, although the bacterial compositions were different among cattle groups. Zymograms of whole proteins in rumen fluids showed endoglucanase activities at 55 and 57 kDa and xylanase activity at 44 kDa in all cattle. Meanwhile, several fibrolytic isozyme activities differed among cattle groups and individuals. Treponema, Succinivibrio, Anaeroplasma, Succiniclasticum, Ruminococcus, and Butyrivibrio showed positive correlations with fibrolytic isozyme activities. Further, endoglucanase activity at 68 kDa was positively correlated with pH. This study suggests the characteristics of fibrolytic isozyme activities and their correlations with the rumen microbiota.     

Preventive effect of sialylglycopeptide-nondigestive polysaccharide conjugates on salmonella infection

We have previously reported that sialylglycopeptide (SGP) and its derivatives isolated from egg yolk had a preventive effect on Salmonella infection in vivo; however, their retention time in the gut was rather short. To improve on this, SGP was conjugated with carboxymethyl cellulose (CMC) or carboxymethyl dextran (CMD). The conjugates inhibited the binding of Salmonella enteritidis and Escherichia coli to Caco-2 cells. Infection experiments with mice revealed that the SGP-CMD conjugate (SGP-CMD) had a strong protective effect against Salmonella infection. A turnover experiment in mice administered with radiolabeled SGP-CMD showed that SGP-CMD was more slowly absorbed into the blood and thus remained longer in the intestinal tract than SGP. SGP-CMD itself did not influence the production of tumor necrosis factor alpha (TNF-alpha), interleukin-1 beta, or nitrite ion (NO(2)(-)) by macrophages, although it suppressed that of TNF-alpha and NO(2)(-) in zymosan-treated macrophages, suggesting no causative effects of inflammation in SGP-CMD. SGP-CMD is potentially useful as a food ingredient with a preventive effect on Salmonella infection.     

基于PCA和聚类分析的茶树F1代茶多酚遗传分析

高效液相色谱检测茶树(Camellia sinensis (L.) O.Kuntze) 14个红富贵×红交27的F1代单株、7个红交27×F95181 F1代单株及其亲本中各儿茶素组分含量,利用主成分分析和聚类分析研究了茶多酚在品种间杂交F1代的遗传规律.结果显示,红富贵×红交27 F1代14个单株茶多酚的表型以3:1...     

The hypocholesterolemic activity of transgenic rice seed accumulating lactostatin, a bioactive peptide derived from bovine milk β-lactoglobulin

Lactostatin is a novel pentapeptide (IIAEK) derived from bovine milk β-lactoglobulin with greater hypocholesterolemic activity than β-sitosterol, the drug commonly used to treat hypercholesterolemia. We developed transgenic rice expressing lactostatin as a fusion protein with seed storage protein (SSP) glutelins under the control of three different endosperm-specific promoters. Lactostatin accumulated in transgenic rice seed at approximately 1.6 mg/g seeds (dry seeds) without any apparent influence on seed traits such as endogenous SSP expression levels or alterations in the intracellular structures of endosperm cells. Short-term (three day) oral administration of the glutelin fraction containing lactostatin (namely three times of 300 mg/kg body weight/day) extracted from transgenic rice seeds resulted in hypocholesterolemic activity in rats; namely, the serum low-density-lipoprotein (LDL) cholesterol level was significantly reduced accompanied by a significant increase in beneficial serum high-density-lipoprotein (HDL) cholesterol.     

Broth from canned clams is suitable for use as an excellent source of free vitamin B12

Vitamin B(12) was assayed and characterized in the broth of canned clams (boiled plain). The broth contained considerable amounts of vitamin B(12) (2.7-14.1 μg/100 g, 1.3-6.7 μg/can). HPLC and LC/ESI-MS/MS chromatograms demonstrated that the clam broth contained true vitamin B(12). Gel filtration experiments indicated that most (72%) of the vitamin B(12) found in the broth was recovered in free vitamin B(12) fractions. These results indicate that the clam broth would be suitable for use an excellent source of free vitamin B(12) for elderly persons with food-bound vitamin B(12) malabsorption.     

A black soybean seed coat extract prevents obesity and glucose intolerance by up-regulating uncoupling proteins and down-regulating inflammatory cytokines in high-fat diet-fed mice

Black soybean seed coat extract (BE) is a polyphenol-rich food material consisting of 9.2% cyanidin 3-glucoside, 6.2% catechins, 39.8% procyanidins, and others. This study demonstrated that BE ameliorated obesity and glucose intolerance by up-regulating uncoupling proteins (UCPs) and down-regulating inflammatory cytokines in C57BL/6 mice fed a control or high-fat diet containing BE for 14 weeks. BE suppressed fat accumulation in mesenteric adipose tissue, reduced the plasma glucose level, and enhanced insulin sensitivity in the high-fat diet-fed mice. The gene and protein expression levels of UCP-1 in brown adipose tissue and UCP-2 in white adipose tissue were up-regulated by BE. Moreover, the gene expression levels of major inflammatory cytokines, tumor necrosis factor-α and monocyte chemoattractant protein-1 were remarkably decreased by BE in white adipose tissue. BE is a beneficial food material for the prevention of obesity and diabetes by enhancing energy expenditure and suppressing inflammation.