A new assay using surface plasmon resonance (SPR) to determine binding of the Lactobacillus acidophilus group to human colonic mucin

A new binding assay to investigate the mechanism of adhesion of lactic acid bacteria to the human intestine was established by the surface plasmon resonance technique using a biosensor BIACORE1000. Cells of 26 strains of the Lactobacillus acidophilus group as analytes were eluted onto a sensor chip on which were immobilized biotinylated A-trisaccharide polymer probes having human A-type antigen [(GalNAcalpha1-3(Fucalpha1-2)Gal)-] or human colonic mucin of blood type A (HCM-A) as ligands. In the first screening, high adhesive affinity to the A-trisaccharide BP-probe was observed in L. acidophilus OLL2769, L. crispatus JCM8778, LA205 and LA206. In the second screening, which used HCM-A, only L. acidophilus OLL2769 and L. crispatus JCM8778 were selected as adhesive strains with specific binding ability to human A-antigen. The results indicated that some strains of the L. acidophilus group could recognize and bind the sugar chain of A-antigen structure on HCM.     

A novel and simple method for quantification of small,dense LDL

A preponderance of small, dense (sd) LDL is strongly associated with the development of coronary heart disease, but the method for the measurement of sd LDL is too laborious for clinical use. We report a simple method for the quantification of sd LDL that is applicable to an autoanalyzer. This method consists of two steps: first, to precipitate the lipoprotein of density (d) <1.044 g/ml using heparin-magnesium; and second, to measure LDL-cholesterol in the supernatant by the homogeneous method or apolipoprotein B (apoB) by an immunoturbidometric assay. The cholesterol and apoB values obtained by the precipitation method (45 +/- 26 and 33 +/- 20 mg/dl, respectively) were similar to those obtained in the lipoprotein (d = 1.044-1.063) separated by ultracentrifugation (42 +/- 22 and 31 +/- 17 mg/dl, respectively), and there was an excellent correlation between the two methods for sd LDL-cholesterol (y = 1.05X + 1, r = 0.88, n = 69) and apoB (y = 1.07X, r = 0.90). Sd LDL values had a significant inverse correlation with LDL size. A high correlation was found between sd LDL-cholesterol and apoB values (r = 0.94). Sd LDL value was related to triglyceride, apoB, and LDL-cholesterol, but not to the buoyant LDL level. These results suggest that this precipitation method is a simple and rapid method for the measurement of sd LDL concentration.     

Crystal structure of chartreusin derivative A132

The crystal structure of chartreusin derivative A132 (benzilidene chartreusin) has been determined by single-crystal X-ray diffraction. The space group is C2 with unit cell dimensions, a=18.482(4), b=8.749(3), c=43.906(2) A, beta=94.87(2) degrees, and the structure was refined to R-factors of 0.2365 (6585 all unique reflections) and 0.087 (2914 reflections with F(o)>4 sigma(F(o))) by a full-matrix least-squares method. There are two molecules in an asymmetric unit. Both molecules have similar structures, which are favorable to bind with DNA in the minor groove. A modeling study of the A132-DNA complex based on the X-ray structures suggests that the sugar moiety of A132 may play an important role in recognizing the sequence of DNA base pairs.     

Increased expression of cardiotrophin-1 during ventricular remodeling in hypertensive rats

Cardiotrophin-1 (CT-1) stimulates longitudinal myocardial cell hypertrophy. We examined the expression of CT-1, leukemia inhibitory factor (LIF), and gp130 by competitive RT-PCR and Western blotting in Dahl salt-sensitive (DS) rats with a high-salt diet, which showed a distinct transition from left ventricular hypertrophy (LVH) to congestive heart failure (CHF). The expression levels of CT-1 mRNA and protein were significantly increased at the CHF stage compared with the LVH stage and age-matched Dahl salt-resistant (DR) rats (n = 6 for each group). mRNA expression of LIF was not changed in the left ventricle at any stage by RT-PCR. gp130 mRNA and protein levels of DS rats at 11 and 17 wk were significantly increased compared with age-matched DR rats. The isolated myocyte length of DS rats at 17 wk was the longest among the four groups of rats. The LV end-diastolic dimension (LVDd) of DS rats, determined by echocardiography, was significantly increased at the CHF stage. There was a significant correlation between the CT-1 protein level and LVDd. CT-1 may play a role in ventricular remodeling during transition from LVH to CHF in the rat hypertensive model.     

Molecular species of glycinin in some soybean cultivars

A(4) polypeptide-containing (Shirotsurunoko and York) and A(4) polypeptide-lacking (Raiden and Suzuyutaka) soybean cultivars were used to investigate the heterogeneity of glycinin molecular species. Purification of glycinin by DEAE-Toyopearl column chromatography afforded molecular species eluting before the glycinin fraction. Analysis of this fraction by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and sucrose density gradient centrifugation indicated that this protein consisted of A(1) and A(2) polypeptides. The A(4)-containing soybean cultivars contained less of this protein than the A(4)-lacking soybean cultivars, as exhibited by the size of the early peak appearing during column chromatography. Alkaline PAGE and N-terminal amino acid sequence analysis confirmed that the A(1)- and A(2)-rich molecular species in the A(4) polypeptide-lacking cultivars consisted of the A(1a) and A(2) polypeptides. Estimation of the molecular mass by gel permeation chromatography and multi-angle laser light scattering (GPC-MALLS) indicated that the A(1a)- and A(2)-rich molecular species were similar to a monomer of glycinin.     

A Role for Caspases in Lens Fiber Differentiation

There is increasing evidence that programmed cell death (PCD) depends on a novel family of intracellular cysteine proteases, called caspases, that includes the Ced-3 protease in the nematode Caenorhabditis elegans and the interleukin-1β–converting enzyme (ICE)-like proteases in mammals. Some developing cells, including lens epithelial cells, erythroblasts, and keratinocytes, lose their nucleus and other organelles when they terminally differentiate, but it is not known whether the enzymatic machinery of PCD is involved in any of these normal differentiation events. We show here that at least one CPP32 (caspase-3)-like member of the caspase family becomes activated when rodent lens epithelial cells terminally differentiate into anucleate lens fibers in vivo, and that a peptide inhibitor of these proteases blocks the denucleation process in an in vitro model of lens fiber differentiation. These findings suggest that at least part of the machinery of PCD is involved in lens fiber differentiation.     

Evidence from Crosslinking for Nearest-Neighbor Relationships among the Three Extrinsic Proteins of Spinach Photosystem II Complexes that are Associated with Oxygen Evolution

Treatment of oxygen-evolving Photosystem II complexes, whichlack light-harvesting chlorophyll a/b proteins, with a seriesof disuccinimidyl esters with different chain lengths yieldeda crosslinked product which consisted of one molecule each ofthe extrinsic 33 kDa and 23 kDa proteins. In addition, crosslinkingbetween the 33 kDa protein and the chlorophyll-carrying 47 kDaprotein and between the 23 kDa and 17 kDa proteins was confirmed.Thus, the three extrinsic proteins are closely associated witheach other to form a complex which is attached to the PS IIreaction center complexes. (Received December 1, 1989; Accepted May 2, 1990)     

Lysophosphatidylcholine Acyltransferase1 Overexpression Promotes Oral Squamous Cell Carcinoma Progression via Enhanced Biosynthesis of Platelet-Activating Factor

Background

The relevance of lysophosphatidylcholine acyltransferase1 (LPCAT1), a cytosolic enzyme in the remodeling pathway of phosphatidylcholine metabolism, in oral squamous cell carcinoma (OSCC) is unknown. We investigated LPCAT1 expression and its functional mechanism in OSCCs.

Methods

We analyzed LPCAT1 mRNA and protein expression levels in OSCC-derived cell lines. Immunohistochemistry was performed to identify correlations between LPCAT1 expression levels and primary OSCCs clinicopathological status. We established LPCAT1 knockdown models of the OSCC-derived cell lines (SAS, Ca9-22) for functional analysis and examined the association between LPCAT1 expression and the platelet-activating factor (PAF) concentration and PAF-receptor (PAFR) expression.

Results

LPCAT1 mRNA and protein were up-regulated significantly (p<0.05) in OSCC-derived cell lines compared with human normal oral keratinocytes. Immunohistochemistry showed significantly (p<0.05) elevated LPCAT1 expression in primary OSCCs compared with normal counterparts and a strong correlation between LPCAT1-positive OSCCs and tumoral size and regional lymph node metastasis. In LPCAT1 knockdown cells, cellular proliferation and invasiveness decreased significantly (p<0.05); cellular migration was inhibited compared with control cells. Down-regulation of LPCAT1 resulted in a decreased intercellular PAF concentration and PAFR expression.

Conclusion

LPCAT1 was overexpressed in OSCCs and correlated with cellular invasiveness and migration. LPCAT1 may contribute to tumoral growth and metastasis in oral cancer.