All pyruvylated galactose in Schizosaccharomyces pombe N-glycans is present in the terminal disaccharide, 4, 6-O-[(R)-(1- carboxyethylidine)]-Galbeta1,3Galalpha1-

The large N-linked oligosaccharides released from Schizosaccharomyces pombe by endo-beta-N-acetylglucosaminidase H were examined to determine how the negatively chargedpyruvylated galactoses present (Gemmill,T.R., and Trimble,R.B., 1996, J. Biol. Chem ., 271, 25945-25949) were attached to the oligosaccharide chains. Binding of biotinylated human serum amyloid P and peanut agglutinin to native and depyruvylated S.pombe glycoproteins, respectively, indicated that the pyruvylated epitope was likely to be in the beta configuration. Examination by high- field 1H NMR of whole glycans and a disaccharide fragment released from them on partial acid hydrolysis showed that the pyruvylated galactose species was in fact beta1,3-linked to a second galactose, and this occurred an average of five to six times on nominal Gal57Man64GlcNAc N- glycans. The pyruvate-2,(4,6)Gal-beta1,3Gal epitope is chemically similar to acetaldehyde-Galbeta1,3Gal groups found on the glycoproteins from Paramyxovirus-infected bovine kidney cells (Prehm, P., Scheid,A. and Choppin,P.W. ,1979, J. Biol. Chem ., 254, 9669-9677). The 1:1 stoichiometry between pyruvate and beta-linked galactose in these S.pombe glycans indicates that either pyruvate addition to terminal beta1,3Gal is highly efficient or that pyruvylated Gal is transferred en bloc to alpha1,2-linked Gal residues in theN-linked chains. In contradiction to many galactomannan-producing fungi, which add substantial amounts of Gal in the furanose form to their glycoproteins, all detectable Gal in the large S.pombe galactomannans is in the pyranose form, as found in higher eukaryotes. The current work shows that the S.pombe outer chain structure is a poly-alpha1,6Man backbone 2- O-substituted with either Gal or the pyruvylated galactobiose and contains little alpha1,2-linked or 2-O-substituted Man. This is in contrast to the S. cerevisiae outer chain, which is poly-alpha1,6Man substituted with alpha1,2-linked Man sidechains (Ballou,C.E. ,1990, Methods Enzymol , 185, 440-470).      

Differences of subcutaneous adipose tissue topography between type-2 diabetic men and healthy controls

Men with noninsulin-dependent diabetes mellitus (type 2 DM) provide a different subcutaneous body fat distribution and a concentration of fatness on the upper trunk compared with healthy subjects. However, subcutaneous fat distribution is always measured in an inaccurate and/or very simplified way (e.g., by caliper), and to date, there exists no study reporting on the exact and complete subcutaneous adipose tissue distribution of type 2 DM men. A new optical device, the LIPOMETER, enables the nonivasive, quick, and safe determination of the thickness of subcutaneous adipose tissue layers at any given site of the human body. The specification of 15 evenly distributed body sites allows the precise measurement of subcutaneous body fat distribution, so-called subcutaneous adipose tissue topography (SAT-Top). SAT-Tops of 21 men with clinically proven type 2 DM (mean age of 57.5 +/- 6.7 years) and 111 healthy controls of similar age (mean age 59.0 +/- 5.4 years) were measured. In this paper, we describe the precise SAT-Top differences of these two groups and we present the multidimensional SAT-Top information condensed in a two-dimensional factor value plot. In type 2 DM men, especially in the upper trunk, SAT-Top is significantly increased (up to +50.7% at the neck) compared with their healthy controls. One hundred eleven of the 132 individuals (84.1%) are correctly classified (healthy or type 2 DM) by their subcutaneous fat pattern by stepwise discriminant analysis.     

Subcutaneous adipose tissue exerts proinflammatory cytokines after minimal trauma in humans

Inflammatory cytokines released from adipose tissue play an important role in different pathological processes. In the present study, we investigated the inflammatory cytokine response of human subcutaneous adipose tissue (SAT) by applying the open-flow microperfusion technique. Four standard 18-gauge microperfusion catheters were inserted into periumbilical SAT of eight healthy male volunteers [29 +/- 3 yr, BMI 24.3 +/- 1.9 (mean +/- SD)]. SAT probe effluents were collected at 60-min intervals for 8 h after catheter insertion. Different perfusion fluids were used to measure the local effect of insulin and/or glucose on the cytokine response. SAT probe effluents were analyzed for IL-1beta, IL-6, CXCL8 (IL-8), and TNF-alpha. SAT concentrations of IL-1beta increased 100-fold from 1.0 +/- 0.2 pg/ml (mean +/- SE) to 101.5 +/- 23.2 pg/ml (P < 0.001) after 8 h. A 130-fold increase was observed for CXCL8, from 49 +/- 29 to 6,554 +/- 1,713 pg/ml (P < 0.001). Furthermore, a 20-fold increase of IL-6 was observed within the first 5 h (from 159 +/- 123 to 3,554 +/- 394 pg/ml; P < 0.001), and a significant decline to 2,154 +/- 216 pg/ml (P < 0.01) was seen thereafter. Finally, TNF-alpha increased from 1.4 +/- 0.6 to 2.5 +/- 0.5 pg/ml (P < 0.05) in hour 2 and remained stable thereafter. Local administration of insulin exerted a stimulatory effect on the inflammatory response of IL-6. In conclusion, SAT exerts a highly reproducible and consistent proinflammatory cytokine response after minimally invasive trauma caused by the insertion of a catheter in humans.     

Androgen levels and metabolic parameters are associated with a genetic variant of F13A1 in women with polycystic ovary syndrome

The polycystic ovary syndrome (PCOS), characterized by hyperandrogenism, is one of the most common hormonal disorders among premenopausal women and is associated with infertility, obesity, and insulin resistance. Accumulating evidence suggests a role of the blood coagulation factor gene F13A1 in obesity (GeneBank ID: NM_000129.3). The aim of this study was to investigate the association of intronic allelic variants of the F13A1 gene with PCOS susceptibility and metabolic parameters in lean and obese PCOS women. In a case-control study, we determined an intronic F13A1 single nucleotide polymorphism (SNP) (dbSNP ID: rs7766109) in 585 PCOS and 171 control women and tested for PCOS susceptibility and associations with anthropometric, metabolic and hormonal parameters. Genotype frequencies of the F13A1 SNP rs7766109 were equivalent in PCOS and control women. In PCOS women, F13A1 gene variants were significantly associated with body mass index (BMI) (p=0.013), systolic blood pressure (p=0.042), insulin response (AUCins) (p=0.015), triglycerides (TG) (p=0.001), and high density lipoprotein cholesterol (HDL) (p=0.012). In the subgroup of obese PCOS women free androgen index (FAI), free testosterone and sex hormone binding globulin (SHBG) as well as glucose measurements showed a significantly different pattern across F13A1 gene variants (p=0.043; p=0.039 and p=0.013, respectively). We report for the first time an association of the F13A1 SNP rs7766109 with BMI, androgens, and insulin resistance in PCOS women. Further studies are needed to confirm our findings and to evaluate whether F13A1 is causally involved in the pathogenesis of PCOS related metabolic and hormonal disturbances.